design manufacture hydraulic pressing tools to support maintenance and repair for codia industrial solutions company

TECHNOLOGY AND EDUCATIONMINISTRY OF EDUCATION AND TRAININGHO CHI MINH CITY UNIVERSITY OF DESIGN, MANUFACTURE HYDRAULIC PRESSING TOOLS TO SUPPORT MAINTENANCE AND REPAIR FOR CODIA INDUSTRI

INTRODUCTION TO THE TOPIC

Urgency of the subject

1.1.1 Introduction to the Role of Hydraulic Press Machines in Maintenance

In the context of the modern industry, hydraulic press machines play a crucial role not only in the production process but also in creating products for the replacement, maintenance, and repair of machine components within enterprises

One of the primary applications of hydraulic press machines is in shaping and processing metal components according to desired sizes and shapes With the ability to generate high pressure, this machine can perform strenuous processes such as flattening and reshaping previously manufactured components By utilizing powerful hydraulic pressure, it can refurbish and restore damaged components, minimizing both time and costs compared to replacing entire parts Hydraulic press machines are often used to press products on punch and dies, ensuring that the final products meet the requirements for maintenance and repair

Figure 1.1 Using a hydraulic press for bearing repairs 1.1.2 Introduction to the Manufacturing Sector of Codia Company's Machinery

Codia is a company specializing in consulting and designing specialized mechanical machinery, providing customized automated production lines for the food and agriculture industries The company's expertise includes rapid prototyping design and precision mechanical processing

Figure 1.2 Some machines of CODIA company

1.1.3 The Role of Maintenance and Repair Inspection at CODIA Company

The inspection, maintenance, and repair of certain parts within machinery and equipment systems after a period of use are crucial steps in a company's production process The purpose of these inspections is to minimize downtime, ensure safety, and maintain operational efficiency so that the machinery can produce the highest quality products However, the company currently lacks the necessary equipment for maintenance and repair Therefore, acquiring some hydraulic presses to meet the maintenance and repair needs is essential for the company to meet the challenging maintenance and repair requirements it faces

1.1.4 Current State of Maintenance and Repair Activities at Codia Company

As mentioned in section 1.3, the Company is currently facing many difficulties in maintenance and repair due to lack of support tools, forcing it to buy new components to replace, leading to high costs Specifically, during the maintenance and operation of the spring roll rolling machine, some V-shaped parts used to fix the pneumatic cylinder assembly, roller assembly and motor were bent or randomly damaged So it needs to be replaced or bent back to the correct 90 degree angle

Figure 1.4 The V-shaped plates used to secure pneumatic cylinder

Figure 1.5 The V-shaped plates are used to support the rulo shaft

For the reasons mentioned above and the significance as stated, our team has decided to choose the topic "DESIGN AND MANUFACTURE HYDRAULIC PRESS TOOLS TO SUPPORT MAINTENANCE AND REPAIR FOR CODIA INDUSTRIAL SOLUTIONS COMPANY." This is to serve the purpose of improving product quality, optimizing maintenance, and developing new types of automated machinery to benefit the company specifically Through this topic, the student group hopes to apply the knowledge they have learned into practice to manufacture and contribute a small part to the development of our country's current industry

The company's maintenance and repair products are very diverse, such as bearings, metal sheet flattening However, the company only requires the manufacture of hydraulic presses with an anvil and mortar assembly that can press V-shaped pieces with a thickness of less than 6mm and a bending angle of 90 degrees, in order to replace and maintain the V- shaped parts of machinery This also serves to evaluate the effectiveness that the machinery brings, from which there are demands for improvements, upgrades, or new constructions to test and maintain replacements as per the company's necessary requirements.

The practical significance of the topic

Upon completion, the project will be immediately implemented in production at CODIA Company to address the specific challenges that the company is currently facing The V- shaped components produced will be supplied for the replacement, maintenance, and repair of the company's machinery and equipment

For the team of authors, the project presents an opportunity to review and gain a deeper understanding of theoretical concepts they have learned It offers a chance to enhance skills, acquire experience, and gain a deeper insight into the practical application of the knowledge obtained

General Objectives

- Understand the functions, principles, control mechanisms, and models of hydraulic presses

- Design and manufacture components based on the design of existing hydraulic presses on the market to make them more practical and applicable to production

- Design and manufacture the assembly of the V-shaped punch and die for maintenance and repair purposes

- Search for relevant documents and conduct related research

- Research the principles of hydraulic pressing and the assembly of the V-shaped punch and die

- Survey the types of hydraulic presses currently available on the market

- Manufacture and order the necessary components for assembly

- Test, evaluate the product, and record the results.

Research Objectives and Scope

- V-shaped Metal Bending punch and die

- Design Software for creating models and publishing drawings

- Machine structure and relevant calculated parameters

- Machine size and workspace dimensions: 562x400x1345 (mm)

- Press with a load-bearing capacity of 10 tons

- Specifications of V-shaped die: 250x50x20 (mm), bending angle of 90°

- The hydraulic press is suitable for materials steel

- Materials with a thickness below 6 mm.

Research Methodology

The research methodology relies on existing knowledge of hydraulic press machines Subsequently, a synthesis and evaluation of proposed solutions will be conducted, determining which cases are optimal and which are suboptimal

Document Collection and Synthesis Method: Gathering, analyzing, and translating documents related to hydraulic pressing technology Ensuring diversity,

5 multidimensionality, and leveraging the findings of the latest research relevant to the topic of the study Observing hydraulic press machine designs from previous versions Reference materials are collected from books, textbooks, and the internet

Utilization of Inventor 2020 Software: Using Inventor 2020 software for product design, followed by subsequent steps such as manufacturing and processing of materials

Experimental Analysis Method: Based on the results obtained from experiments, appropriate machine parameters will be selected.

Structure of the Graduation Project

The Graduation Project "DESIGN AND MANUFACTURE OF HYDRAULIC PRESS TOOLING FOR MAINTENANCE AND REPAIR SUPPORT FOR CODIA INDUSTRIAL SOLUTIONS COMPANY" comprises six chapters:

Chapter 1: Introduction To The Topic

RESEARCH OVERVIEW

Overview of Hydraulic Pressing Technology

Hydraulics is a field of physics and engineering specializing in the use of pressurized fluids to transmit energy It is based on Pascal's principle, which states that pressure applied to a fluid in a closed system is transmitted evenly throughout the fluid without diminishing This mechanism allows hydraulics to perform heavy-duty tasks and precise control in various applications, from industrial machinery to transport vehicles and lifting equipment

Figure 2.1 The operation of hydraulics Pascal's law is a principle in fluid physics and it has a significant impact on the operating principle of hydraulics Pascal's law states that when pressure is applied uniformly to an incompressible fluid, this pressure is transmitted equally in all directions and remains equally strong at every point

At a basic level, Pascal's law can be described by the formula:

P is the pressure (unit: bar)

F is the force applied to the fluid (unit: N)

A is the area over which the force is applied (unit: m²)

In hydraulic presses, this principle is used to create large forces by applying a small force over a small area When the force is applied to the fluid, it creates pressure and moves the fluid to cylinders and pistons, which increases the force and produces a large output

2.1.2 Overview of the Hydraulic Pressing Method

The hydraulic pressing method is a technique that employs fluid pressure to generate compressive forces or mechanical movement In many applications, the fluid used is often hydraulic oil The process consists of a basic hydraulic system, which includes a reservoir to hold the fluid, a pump to generate pressure, conduits for the fluid, control valves, and hydraulic apparatus such as pistons or cylinders

The hydraulic pressing method is utilized in processing a wide variety of materials, including metals, wood, and plastics

Figure 2.2 Hydraulic Wood Press Machine Hydraulic pressing offers the ability to create powerful compressive forces, aiding in the handling and forming of hard materials such as metals It provides the capability to easily adjust the pressing force to meet the specific requirements of the product or manufacturing process This method can be applied to various types of materials and is used in many different industries

Hydraulic pressing is suitable for large-scale manufacturing processes and can be automated to enhance efficiency Compared to some other manufacturing methods, the equipment costs for a hydraulic system can be relatively low

Hydraulic systems are designed for high safety and often have long-term durability.Hydraulic pressing allows for the fabrication of complex details with high precision and the ability to be replicated multiple times.Hydraulic systems are generally easy to maintain and repair, helping to minimize production downtime due to malfunctions

Overview of the Metal workpiece Pressing Process

Diagram of the metal workpiece pressing process:

Details of the metal workpiece pressing process:

 Preparation of workpiece and die

Prepare metal sheet: Select the appropriate type of metal sheet that meets the requirements of the product, including thickness, size, and type of metal

Prepare the die to match the shape and size of the final product The die can be made from steel or other materials depending on the complexity and volume of products to be produced

Cutting: Use laser cutting machines, plasma cutting machines, or mechanical cutting equipment to cut the sheet metal to the required size and shape

 Prepare the machine: Conduct a detailed inspection of the hydraulic press machine, examining each component, checking the hydraulic oil level, and determining the necessary pressure for bending processes based on the type of metal and thickness of the workpiece

 Bending: Apply bending force to the sheet metal to create specific angles and shapes Hydraulic bending machines or mechanical bending machines may be used

Prepare Mold and workpiece Prepare the machine Bending Check the product

 Inspection: The finished product is thoroughly inspected to ensure quality and accuracy according to requirements.

Classification by machine frame shape

In terms of machine shape and structure, there are hydraulic presses with C-frame, H-frame

 C- frame press: convenient for stamping, smoothing, and bending operations

 Capable of transmission with high power and pressure

 Simple mechanism, operates with high reliability, requires minimal maintenance

 Compact and lightweight structure, the positions of driving and driven elements are independent of each other

 Reduces the size and weight of the entire system by increasing working pressure

 Overload prevention thanks to a safety valve

 Easy to monitor the hydraulic circuit with the help of a pressure gauge

 Standardized components facilitate design and manufacturing

 Low efficiency due to pipeline losses and leaks from components

 At startup, changes in the system temperature lead to changes in the fluid's viscosity and, consequently, changes in the working speed

 The hydraulic system and electrical control system of the machine are designed to operate in 2 modes: manual mode and automatic mode

 The automatic mode can be easily adjusted in work logic sequence through the connection of electrical circuit diagrams and hydraulic circuit diagrams

 In manual operating mode, all motion processes of the cylinder are controlled by buttons or levers.

Overview of the Manual Hydraulic Press workpiece Method

Diagram of the manual hydraulic press:

The main method involves manually applying force to a hydraulic cylinder to make the cylinder press the workpiece

Place the workpiece in the pressing position

Apply force manually to the cylinder

Remove the pressed workpiece from the die

Advantages: compact, easy to transport, suitable for pressing small quantities of products

Disadvantages: mostly limited to producing small quantities, labor-intensive, products may not achieve high uniformity.

Overview of the hydraulic pressing method using semi-automatic hydraulic press

 The main method involves using hydraulic cylinders controlled by a motor to replace manual labor

Place the workpiece into the die

Adjusting pressure of hydraulic system

Carrying out the pressing process

Take the workpiece out of the bending die

Inspect products and evaluate quality

 Workers position the workpiece for pressing, adjust the appropriate pressure, and then activate the hydraulic cylinder to initiate the pressing process

Figure 2.9 Semi-automatic hydraulic press

Advantages: Suitable for pressing large quantities of products with high productivity and precision

Disadvantages: High manufacturing, maintenance, and operating costs.

Some Automatic Press Machines on the Market

Based on the topic: RESEARCH INFLUENCE OF PRESSURE IN THE MOULDING

OF SOIL BRICK BY SEMI-DRY METHOD by author Nguyen Tien Dung published in the Journal of Construction Science and Technology NUCE 2018 [15] In this study, the author used a pressing machine Hydraulically shapes unburnt clay bricks using the semi-dry pressing method

Through experimental research, we have built a relationship between pressing pressure and settlement of the product when pressed

Figure 2.11 Hydraulic brick press Foreign :

Based on the research of the topic "Advancement Of Pressure Switch Hydraulics Press Machine" published in International Journal Of Creative Research Thoughts- IJCRT Volume 6, Issue 2 April 2018 | ISSN: 2320-2882.[10]

In this research, the authors studied the use of a pressure switch to enhance the power of the hydraulic press machine, which converts electrical energy into mechanical work without increasing the motor's output The outcome of this research process is a machine used to compress 200kg of plastic bottles and cardboard boxes

5 Weight Of The PressMachine 20000KN

Table2.1 Specifications of plastic bottle and carton hydraulic press

14 Figure 2.12 Plastic bottle and carton press machine

THEORETICAL BASIS

Operating Principle

The workpiece is placed on the mold of the machining table, then the hydraulic power is activated to start the pressing process Under the force of the piston cylinder, the ram is pressed down, directly impacting the metal blank to deform it according to the V-Die, achieving a 90-degree angle, and ultimately producing the desired product.

Theoretical Basis of Metal Bending

3.2.1 Definition and Characteristics of the Bending Process

In metal sheet fabrication, V-bending is a common method used to shape a metal sheet at a specific angle, typically to form shapes like V, U, or other folded structures There are two important concepts in this process: free bending and bottom bending

Free Bending: Free bending is a bending method where the metal sheet is bent around a die without fully conforming to the die shape This allows the metal to "slide" or move slightly during bending, which reduces the pressure needed to perform the bend and decreases the risk of cracking or breaking Free bending is often used when the precision of the bend angle does not have to be extremely high or when a wide bend angle is required

Bottom Bending: In bottom bending, the metal sheet is fully pressed against the die, creating a more precise bend angle This process requires higher bending pressure than free bending but produces more accurate and clean bends, with less deformation Bottom bending is suitable for applications requiring high precision in shape and size

Both methods have their advantages and disadvantages, and the choice between them depends on the specific requirements of the product, including the precision of the bend angle, the type of material, and the thickness of the metal sheet Free bending is generally quicker and less expensive, while bottom bending provides better precision and surface finish

The hydraulic cylinder proceeds to press

The workpiece is placed on the V die of the workbench Product

Start the hydraulic power source

Bend Radius: The smaller the bend radius, the greater the force required for bending The bend radius also affects the degree of stretching of the outer surface and compression of the inner surface of the material during bending

Material Thickness: The greater the thickness, the greater the bending force required Material thickness also affects the material's ability to bend flexibly

Material Properties: Material properties such as hardness, elasticity, and yield strength affect the bending process

3.2.2 Characteristics of the Bending Process

Under the pressure of the punch , the workpiece undergoes plastic deformation in each region to form the required shape The deformation process also includes elastic deformation and plastic deformation

Figure 3.1 illustrates the continuous V-bending process Initially, the punch only contacts the workpiece at the punch tip As the punch moves down, it bends the workpiece and gradually reduces the bend radius Finally, the workpiece is tightly compressed between the punch and die, the V-shaped bar is straightened and the top has the smallest bending radius along the tip of the punch

During the bending process, the metal layers on the inner side of the bend (the punch side) undergo compression and contraction in the vertical direction while experiencing tension horizontally Conversely, the metal layers on the outer side (the die side) are subjected to tension and elongation in the vertical direction, compressing horizontally Between the shortened and elongated layers lies a neutral layer (Figure 3.3), with its length equal to theinitial length of the workpiece

In this way, it can be seen that the neutral layer is not a physical layer with specific characteristics; rather, it is a conventionally defined curved surface traversing different layers of laminates When bending thin strips, significant deviations in the cross-sectional shape occur, accompanied by a reduction in the material thickness at the bending location The neutral layer shifts towards the compressed side, and a change in the rectangular shape of the cross-section forms a trapezoid

V-bending mold punch and die

 Technical requirements for the bending die:

 Ease of replacement of worn parts

 Convenient die installation on the machine

The working parts of the bending mold (punch and die) often operate under conditions of impact, high pressure, corrosion, and sometimes in hot environments Their shapes are usually complex and must maintain their shape after heat treatment

Therefore, the materials used for bending molds need to have high hardness, high strength, and good resistance to wear For this press machine, the mold material is made from SKD11 steel

After the ram and die are machined to the correct size and shape as required, we proceed to heat treat the SKD11 steel at a temperature of 980-1050 degrees Celsius to achieve a hardened structure Then, we temper the steel at a temperature of 200-300 degrees Celsius to balance its hardness and toughness, providing good impact resistance during the machining process SKD11 steel is a type of hardened steel with a hardness ranging from 58 to 62 HRC, known for its high wear resistance, commonly used in applications such as knives, bending molds, and precision cutting tools.

Determination of Bending Force

Determining the bending force required to bend a workpiece at a certain angle using a die is a very challenging problem, and can only be estimated approximately This is because the bending force depends on many factors such as:

 Shape and cross-sectional size of the workpiece

 Mechanical properties of the material, distance between the supports

 Radius of curvature of the bending punch and working edge of the bending die

Additionally, the bending force required to bend the workpiece in the bending die at an angle also depends on the degree of contact between the bent blank and the bending punch and die

The bending force consists of free bending force and material flat bending force The values of bending force and flat force are often much larger than the free bending force This stage will end when the workpiece fully contacts the punch and die on all working surfaces

Figure 3.5 The force exerted deforms the metal sheet by the punch

Hot rolled sheet

 Hot rolled blank is metal that has been heated to high temperatures and then rolled into the desired shape

 The hot rolling process creates a structure with large and uneven grain sizes, as well as an oxide layer on the surface

 The mechanical properties of hot rolled blanks typically exhibit higher ductility and mechanical strength compared to cold rolled blanks

 Hot rolled blanks are often used in applications that require the flexibility and uniformity of the final product, such as in the construction, mechanical, and automotive industries

 The workpiece used for V bending is typically a hot rolled blank because the mechanical properties of hot rolled blanks typically exhibit higher ductility and mechanical strength compared to cold rolled blanks has a hardness of 45 to 48 HRC

 The load retention time during pressing of hot-rolled billet and cold-rolled billet is really different, and this can affect the V-bending process in the press brake During experimental testing and product inspection, particularly for steel CT38, the press brake operator needs to be mindful of this issue to ensure that the dwell time is adjusted appropriately to achieve the desired 90-degree bending angle This may require adjustments to the dwell time or bending pressure, depending on the specific characteristics of the blank and the bending process

Hydraulic Pressure Gauge

The pressure gauge in a hydraulic press is an important component that helps operators monitor and control the working pressure of the hydraulic system

Quality control: Helps control product quality by ensuring stable and accurate working pressure.

Hydraulic System

The hydraulic power unit in a hydraulic press plays a crucial role in supplying the necessary energy for shaping materials such as metals The powerful pressing force generated by the hydraulic power unit not only enables the handling of heavy-duty tasks with ease but also ensures high accuracy in the manufacturing process, thereby enhancing product quality and work efficiency The flexibility of the hydraulic power unit also allows the hydraulic press to be configured to perform various types of tasks, with the ability to adjust pressure and speed according to the specific requirements of different materials and tasks Furthermore, integrated safety and protection systems in the power unit help safeguard the machinery from overload and damage, thereby extending the machine's lifespan

Hydraulic Cylinder

The hydraulic cylinder in a hydraulic press is an essential component, responsible for converting hydraulic energy into mechanical energy to perform tasks such as pressing and bending materials The structure and operation of the hydraulic cylinder are crucial factors determining the efficiency, accuracy, and durability of the hydraulic press.

Some products bent on the current market

Currently, there are metal sheet bending products on the market, V-shaped fixtures, which have various applications, including:

Securing components firmly, minimizing vibrations and oscillations during the machining process This is crucial to ensure the surface quality of the components and prevent issues that may arise from unwanted vibrations.Designed to accommodate various sizes and shapes of different components This provides flexibility in the machining process, allowing them to be used for various applications and different types of components

Based on the establishment of detailed maintenance replacement parts for the purpose of internal company maintenance, the company has requested the production of V-shaped details to meet its maintenance and repair requirements The V-shaped, after being bent at a 90-degree angle as required, will be installed to secure certain machine components

Figure 3.10 The V-shaped is used to secure the components in the machine part

DESIGN OPTION SELECTION

Introducing CODIA Industrial Solutions Company

Codia is a company specializing in consulting and designing custom mechanical machinery, providing automated production lines tailored to the requirements of the food and agriculture industries The company's expertise includes design and rapid prototyping, as well as precision mechanical processing on sheet metal using modern technologies such as laser and plasma cutting

Figure 4.1 The spring roll machine with V-shaped details needs maintenance

Figure 4.2 The V-shaped parts in the spring roll rolling machine

Based on figure 4.2, we can see that the detail of the V-shaped will be maintenance and replaced due to warping, no longer maintaining the 90-degree angle after a period of use The maintenance process for the spring roll machine is carried out as follows:

 The details of the components in the machine will be maintained and replaced periodically every 6 months

 Conduct inspections to identify any warped components

 During machine operation, if the V-groove components become warped or deformed, immediate repair or replacement will be carried out

 The V details supporting the roller shaft or cylinder or some other components may become warped, with the warping deviation at 90 degrees

 The method of treatment involves bending the right-angled details back to 90 degrees using a hydraulic press with a set of tools at a 90-degree angle

 The process involves removing the components, bending them back, and then reassembling them into the machine

Therefore, we need to propose a hydraulic press design with a die and punch set to bend the V-shaped details at a 90-degree angle to facilitate the maintenance and replacement of the V- shaped components in the aforementioned process

The company has provided the following design requirements for the machine:

 The time to press one product must be short

 The results of the pressing process of the machine must be highly accurate, improving the quality of the product

 The mechanical structure must be robust, with materials that have high durability and do not deform under the influence of force

 Installation, operation, maintenance, and upkeep costs must be low and suitable for the company's business situation

 The machine is designed to operate in a V-shaped groove to serve the company's maintenance and repair needs.

Machine Structure

Based on the operating principles outlined in the theoretical foundation section, the hydraulic press is structured from the following main components:

Design Options

The design options presented are all based on the following criteria: cost- effectiveness, size of the hydraulic press, system reliability, ease of maintenance, interchangeability of machine components

4.3.1 The design option regarding the machine frame

Option 1: The H-shaped hydraulic press frame design

Figure 4.4 Hydraulic press machine with an H-frame

 Strong Load Bearing Capacity: The H-frame is designed to evenly distribute and withstand high pressure, allowing the machine to endure high pressures during pressing operations

 High Stability: The H-frame structure provides significant stability, ensuring the machine operates powerfully and efficiently

 Easy Operation and Maintenance: Hydraulic press machines with H-frame designs typically feature simple operation and maintenance The H-frame structure also facilitates easy access for maintenance and repairs when needed

 Space Saving: H-frame designs often enable hydraulic press machines to save space, making them suitable for factories with limited space availability

 Disadvantage: Limited size adjustment some models of hydraulic press machines with H- frame designs may have limitations in adjusting the pressing size This can be problematic if frequent adjustments to the product size are required

Option 2: Hydraulic Press Machine with C-frame Design

Figure 4.5 Hydraulic press machine with an C-frame

 Easy Access to Work: The C-frame design often allows easy access to the work area, especially for repair or maintenance tasks

 Flexibility: The C-frame can be adjusted to accommodate various sizes and shapes of products, making it a versatile choice for multiple applications

 Limited Load Bearing Capacity: Due to its compact design, hydraulic press machines with C-frame designs may have limitations in bearing high pressures or pressing hard materials

 Lower Stability: Compared to H-frame designs, C-frames may not provide as much stability during pressing operations, especially under high-pressure conditions

 Conclusion: Based on the company's initial requirements regarding the machine and the advantages and disadvantages of the two options, our team has decided to choose the first design option because it meets the specified requirements such as high stability, good load-bearing capacity, and ease of maintenance

4.3.2 Design Options for the Machine:

 Manual Hydraulic Press Design Option:

 Ease of use: Designed with simplicity in mind, manual hydraulic presses are usually easy to operate and require minimal training for operators

 No power requirement: These machines do not need electricity to operate, making them suitable for environments where power sources may be inconvenient

 Portability: Typically compact and lightweight, manual hydraulic presses are easy to move from one location to another

 High labor intensity: Requires more labor due to manual operation steps such as placing and removing items to be pressed

 Low efficiency: Manual presses have lower efficiency compared to automated hydraulic presses and are not suitable for large-scale production processes

 Low uniformity: Difficult to maintain uniform pressure across the entire pressing surface due to fluctuations in pressure applied by the operator

 Production time: Manual pressing processes often take longer compared to automated machines

 Limited application: Manual hydraulic presses are suitable for small and simple tasks, but may not meet the requirements of complex and large-scale applications

 Design plan for semi-automatic hydraulic press :

Figure 4.7 Semi-automatic hydraulic press

 High productivity: Automated hydraulic presses significantly improve labor efficiency compared to fully manual hydraulic presses, increasing production output

 Flexibility: Pressure can be easily adjusted to suit product requirements, making the machine highly flexible for producing various types of products

 Accuracy and consistency: Automated hydraulic presses provide consistent and precise pressing pressure, improving product quality

 Skill requirements: Operating and maintaining an automated hydraulic press may require specialized skills and training, increasing the complexity and operational costs

 Dependency on power supply: Automated hydraulic presses rely on electricity to operate, making them less suitable for environments with unreliable power sources

Conclusion: Based on the company's initial requirements for the machine as well as the advantages and disadvantages of the two options, our team has decided to choose the second design option because it meets the specified requirements for uniform accuracy, shortening processing time, and flexibility in manufacturing.

Proceed with the design according to the selected option

The frame is chosen to be designed in an H-shape, containing the hydraulic cylinders, the punch and die group

The design process includes the following steps:

 Design the overall shape and size of the machine frame to meet the company's requirements and be suitable for the product being pressed: V-shaped bowl with a bending angle of 90 degrees

 The horizontal steel bars, which bear shear forces, bending moments, and torsional moments, will be designed with the same shape and steel cross-section

 The vertical steel bars, bearing tensile and compressive forces, will be designed with the same shape and steel cross-section

 After designing the dimensions of the machine frame and calculating all the mechanical structure details, proceed to assess the frame's strength to find the suitable shape and cross-sectional dimensions of the steel bars bearing forces

4.4.1 Designing the Dimensions of the Machine Frame

Based on the information about the dimensions of hydraulic presses previously researched, combined with the specified requirements, we will design the appropriate length, width, and height for the workspace of the machine frame, as detailed in Table 4.1

Length of the machine frame (mm)

Width of the machine frame (mm)

Height of the machine frame (mm)

Table 4.1 Machine Frame Dimensions Specifications

Based on the above dimensions, the design has met the company's requirements such as:

 The workspace height must not be too high or low to prevent operators from experiencing health issues spinal problems when working for extended periods

 The workspace must be compatible, and its dimensions must fit with the types of machinery and production lines already present at other stages of the company's manufacturing process This facilitates upgrading, improving, and integrating the machine into the company's production system

Figure 4.8 Overview of the Design and Dimensions of the Machine Frame

Table 4.2 Machine Data 4.4.2 Choosing the Type of Cylinder:

The type of cylinder chosen is the double-acting piston cylinder, which operates in both directions, extending and retracting, using hydraulic oil It is capable of generating compressive force during machining when hydraulic fluid pressure acts on the upper surface and can return when the pressure of the hydraulic fluid acts on the lower surface of the piston The double-acting hydraulic cylinder is a key component in the hydraulic system, used to produce linear motion by utilizing hydraulic oil or fluid

 Linear Motion: Double-acting hydraulic cylinders are commonly used to generate powerful linear motion

 Strong Pressing Force: They are capable of producing significant pressing force, especially in applications requiring high strength such as pressing machines

 High Reliability: Due to the absence of complex transmission components like electric motors, double-acting hydraulic cylinders often exhibit high reliability

 Energy Consumption: Hydraulic systems typically consume more energy compared to some other motion systems due to the need for hydraulic pumps and pressure losses

 Hydraulic Fluid: The use of hydraulic fluid can lead to environmental pollution if leaks or spills occur

 Regular Maintenance: Hydraulic systems require regular maintenance to ensure efficient operation and prevent oil leaks

 Cost: Hydraulic equipment and systems may have higher initial investment costs compared to some other options

 Mass: Hydraulic cylinders typically have a larger mass compared to some other motion systems, which can increase the overall mass of the machinery

Two important parameters to consider when choosing a cylinder are stroke and diameter D

Figure 4.9 Double-acting Hydraulic Cylinder

Based on the length, width, and height of the machine frame combined with a pressing force of 10 tons and the previously stated requirements, we choose to use a double-acting hydraulic cylinder with a 10-ton load capacity, which will be fixedly attached at the midpoint on the upper side of the machine frame

 Some requirements for selecting the cylinder are as follows:

 The pressing force of the cylinder must meet the requirement of 10 tons

 The stroke of the cylinder should ensure sufficient travel, which is 250 mm

 Working pressure in the hydraulic system is an important factor, along with selecting the appropriate hydraulic oil type and operating temperature

 Ensuring safety and durability, the cylinder needs to be designed to withstand impact loads and harsh conditions The material of the cylinder, such as high- strength steel, also plays a crucial role in ensuring load-bearing capacity and maintaining stability

 The cylinder needs to have appropriate size and weight for the press it serves, while ensuring high efficiency and energy savings

 The cost of the cylinder also needs to be considered, while ensuring compliance with safety and industry standards

 The process of selecting the cylinder requires careful consideration of technical, safety, and cost factors to ensure the efficient operation of the 10-ton hydraulic press

DESIGN AND CALCULATIONS

Working Area Dimensions of the Bending Mold

Bending a V-shaped object can be done using two methods: free bending and die bending Free bending, as shown in Figure 5.1a, means that during the bending process, the pestle only applies force to the material at the pestle tip until the two bent parts are parallel to the working surface of the mortar The radius of the bent object will be slightly larger than that of the pestle, and there will be a gap between the bent object and the pestle

Die bending, as shown in Figure 5.1b, involves the bent object being pressed tightly between the working surface of the punch and the die, with the radius of the bent object following the radius of the punch

Figure 5.1 Structure of the V-shaped Bending Mold When bending a V-shape with a flat bottom, the dimensions and structure of the working part of the punch and die are presented in Figure 5.1

To calculate the Punch and V Die in metal bending technology, we need to determine some basic parameters such as the thickness of the metal sheet, the type of material, the bending radius, and the desired bending angle The punch and V die are made of SKD11 steel

Figure 5.2 Dimensions of the V-shaped Bending Mold [1] a) b)

S Thickness of the material to be bent α Bending angle of the die

R Inner bending radius of the bending workpiece a Length of the workpiece edge b Width of the die edge l Width of the V-shaped die opening

R1 Fillet radius of the die

R2 Inner radius of the die h Height of the V-die

Table 5.1 Specifications of the V-bending Die

Figure 5.3 The punch and die components are designed practically

Figure 5.3 presents a V-bending mold with a 90-degree angle featuring a guide shaft

On the lower mold base 1, the bending die is fastened with four M5 hex bolts The bending punch 3 is firmly attached to a metal plate that directly receives force from the cylinder The metal plate is machined with two holes to fit onto two smooth guide shafts number 4, Two guide shafts are mounted to the lower die base with two M10 hex bolts to ensure the most accurate contact between the punch and die during the machining process

 We are bending a metal sheet with dimensions of 133x65x4 mm at a bending angle of 90°

The size of the V Die is selected based on the formula provided in reference [1], which is 5 to 10 times the thickness of the metal sheet

For CT38 steel in the hard material state when bending perpendicular to the rolling direction and bending angle with 𝛼 = 90°:

R = 1.4 = 4 mm The radius of the fillet of the die R1 should not be less than 3 mm

In which K is a selection coefficient based on the type of material and its thickness, and the

K factor can vary, for example, K= 1 for softer metals like aluminum, and K=2 for harder metals such as steel

The distance between the center of the fillet radius of the die and b is 17.5 mm l = 2.b.sin mm [1] l = 2.b.sin = 2.17,5 sin ° = 25 mm The height of the die cavity: h = b.cos – R2 ( – 1) = 17,5.cos ° – 5.( ° – 1) = 12,5 mm [1]

Variable The value of the variable (mm)

Calculate the punch

The punch is designed with a bending angle of 90°

Determination of Bending Force

The bending force P0 (kg) for flat material during V-bending is calculated according to the formula on page 116 of the document [1]:

K = 1,33 when > 6 and k = 1,26 when > 12 : The ratio of the thickness of the compressed area to the thickness of the blank This ratio is important for calculating the bending process [1]

B is width of the bent object, mm

𝜎 is durability limit of materials kg/𝑚𝑚 q is pressure to make flat in kg/𝑚𝑚 , the value is provided in Table 5.3 [1]

F is flat area under the punch, 𝑚𝑚

 Input Parameters : L= 133 mm, l = 25 mm, B = 65 mm, S = 4 mm, r = 4 mm k = = 6,25 we have k = 1,33, R1 = 8 mm

The steel used for the pressing product has a thickness of 4 mm Based on Table 5,3 we select q = 6 Kg/𝑚𝑚

F represents the contact area where it touches the material and creates pressure to deform the material, measured in 𝑚𝑚

Table 5.3 Durability limit of steel σb = 400 Mpa = 40,78 kg/mm²

When bending a metal sheet with dimensions of 133x65x4 mm on an punch and die, a force of 3,4 ton is required

Material The thickness of the material mm

Table 5.4 Pressure to flatten q (Kg/mm²) when bending a V-shaped [1]

 Calculating bending force for a metal plate of size 133x65x6 (mm) with a bending angle of 90 degrees σb = 400 Mpa = 40,78 kg/mm²

P0 = k .B.𝜎 + q.F = 1,33 65.40,78+6.65 = 5466.620 KG When bending a metal sheet with dimensions of 140x30x6 mm on an punch and die, a force of 5,4 ton is required

Calculation and durability testing

 Maximum load and impact on the hydraulic press frame: 10 tons

 The hydraulic press frame is welded with continuous welding (CT38 steel)

Calculating the shape and cross-section of the steel bars that bear the load for the press frame is extremely important To facilitate the calculation process, we preliminarily select the following components:

 Preliminary selection of CT38 steel material and U-shaped steel profile for vertical and horizontal bars in the upper frame for ease of welding

 Selection of CT38 steel material and U-shaped steel profile for horizontal bars to support the workbench in the middle of the machine body

 Selection of CT38 steel material for round bars to make 2 support pins for the workbench during processing

 Selection of CT38 steel material in plate form From the machine frame structure, it is evident that durability needs to be calculated for three components:

 Horizontal steel bars of the upper frame subjected to bending

Calculating the strength of the horizontal U-shaped steel bars on top of the machine

According to the machine frame structure, we see that the horizontal U-shaped bars at the top of the machine have the ability to withstand the loads and pressures during operation Therefore, we select the U-shaped bars as the critical component for calculation

Referring to reference [2], we preliminarily select the U-shaped steel with the following parameters as shown in the image below:

Figure 5.4 Cross-section of the U-shaped steel 120x55x6,3 (mm)

The length of the U-shaped steel is 550 mm

According to the machine frame structure, we observe that the horizontal U-shaped bars at the top of the machine are capable of bearing loads and pressures during operation Therefore, we select the U-shaped bars as the critical component for calculation The forces acting on the horizontal U-shaped bars are as follows:

To draw the internal force diagram, we will use the MD Solid software

 P1 represents the reaction force of the hydraulic cylinder directed upwards on the upper frame of the machine, located at the point of contact between the hydraulic cylinder and the machine frame Its magnitude is 97749 (N)

 P2 and P3 are reaction forces at A and B with their points of application at the contact position with the machine frame The magnitude is P2 = P3 = = = 48874,5 N

We have: The moment of inertia Ix: 350 cm 4 = 3500000 mm 4

Figure 5.5 Cross-section of the 2 U-shaped steel 120x55x6,3 (mm)

The principal moment of inertia about the central axis with respect to the x-axis is denoted as

Because figures I and II are both made of the same steel with the same identification number, and the x-axis passes through the center of mass of both figure I and figure II [11] we have:

Ix = 3500000.2 = 7000000 mm 4 The distance from the central axis to the furthest edge of the cross-section:

Checking the strength of the U-shaped :

𝑀 is the maximum bending moment that the bar can withstand

𝑦 is the distance from the central axis to the furthest point on the cross-section

I is the moment of inertia about the x-axis

Comparing with the tensile and compressive stresses for CT38 steel material, we obtain the result [σk,n] > 𝜎 , 𝜎

Conclusion: The maximum stress acting on the bar is 115.2 Mpa < 𝜎 = 373 𝑀𝑃𝑎 Therefore, U-shaped steel bars ensure durability.

Support pin analysis

Figure 5.6 Support pin for the workbench The force L (pressing force): This is total force acting on both supporting axes L = 98000 N

To calculate the weight W that the support pin must bear :

Figure 5.7 Force acting on the support pin Choosing CT38 steel as the material for the support pin, we have:

Figure 5.8 Cross-sectional image of the support pin

With ӯ is the distance between the NA and the centroid of the half circle: ӯ = Q = A ӯ = ² × = ³ [3]

I: second moment of area t: thickness

Support pin hole contact stress

Figure 5.9 Contact area of the load-bearing bar Support pin hole contact stress:

A is the expected contact area

Based on the inventor software, we calculate the expected contact area to be:

Figure 5.10 Estimated contact area Compressive stress :

Safety factor of the hole :

S.F = = 1,76 With a safety factor of 1,76 the contact area of the hole meets the safety requirement.

Hydraulic Drive System Calculation

 Nominal pressing force of the cylinder: Fmax = 10 tons

 Main cylinder pressing stroke: S = 250 mm

 Maximum working pressure of the cylinder: Pmax = 180 bar

 Cylinder recovery speed during the unloaded stroke: v2 = 31 mm/s

 Other data collected from practical experience

To ensure the efficiency of the working structure, we choose to slightly increase the system pressure Specifically, we select the working pressure of this cylinder as well as the entire system to be p = 180 bar

Some technical specifications required for this cylinder are as follows:

 Force required at the piston head: F = 10 Tons = 980000 N

 Time to complete the forward stroke (corresponding to the pressing process): t1 (s)

 Time to complete the backward stroke of the cylinder: t2 = 8 (s)

To calculate the diameter of the cylinder :

F: is the force generated at the piston head, (N); F = 10 T = 98000 N p: is the working pressure of the cylinder, (bar); p 0 bar

D: is the inner diameter of the cylinder (m)

Thus, the inner diameter of the cylinder is calculated as:

We choose the inner diameter of the cylinder to be D = 80 (mm), and the outer diameter of the cylinder to be Douter = 92 (mm)

To calculate the diameter of the piston head, it is determined using the formula : d = (0,6÷0,8).D = (0,6÷0,8).80 = (48÷64) (mm) [4]

So choose the piston rod diameter as: d = 50 (mm)

So we choose a cylinder according to ISO 6022 standard with inner diameter D (mm) and the outer diameter of the cylinder to be D= 92 (mm), the piston rod diameter as: d = 50 (mm)

5.8.2 Required Flow Rate for the Cylinder

Calculating the required flow rate for the cylinder is crucial in the design calculation of hydraulic systems because based on these results, we can select an appropriate power pump The required flow rate for the cylinder is calculated according to formula :

Q is the required flow rate for the cylinder (liters per minute)

A is the effective area of the cylinder (𝑚 ) v is the velocity of the piston (mm/s)

Therefore, the required flow rate for the cylinder during the pressing process is:

𝑄 =A v1 = × × = , × , = 0,125 (𝑑𝑚 /𝑠) = 7,53 (liters per minute) The required flow rate for the cylinder during the retraction stroke is:

Noting that Q1>Q2 therefore, the flow rate of the power pump must be selected based on Q1

In hydraulic systems, the working fluid is transported from the oil tank through the power pump to the valves, actuators, and then back to the tank through a system of pipelines The commonly used pipelines in hydraulic systems nowadays are rigid pipes (cast iron pipes) and flexible pipes (rubber hoses with steel layers) capable of withstanding pressure To ensure stable operation and high efficiency of the system, energy losses in the pipeline system must be minimized The pipeline system in hydraulic systems in general is divided into 3 parts: suction lines, pressure lines, and return lines The suction line is the section of pipe from the oil tank to the pump, usually quite short The pipeline connecting from the pump to the valves, actuators is called the pressure line, while the line returning to the oil tank is called the return line or drain line To calculate the cross-sectional area of the pipeline, it is necessary to consider the velocity of the oil flow Typically, when selecting pipelines, we must ensure that energy losses in the pipeline are minimized and economically feasible If too small, the losses are large, and if too large, the losses are reduced but not economical, so we must carefully choose the appropriate size Typically, in hydraulic systems in general, the oil flow velocity on the pipeline sections in the system is selected as follows [4]:

The diameter of the pipeline is calculated according to formula :

Q: is the flow rate through the pipe cross-section, also the required flow rate supplied to the cylinder (liters per minute) v: is the velocity of the oil through the pipe cross-section, (m/s)

The diameter of the suction line is calculated as:

Since the suction line supplies oil from the tank to the pump and is located inside the oil tank, it does not have to withstand high pressure We choose the suction line to be made of aluminum or cast iron with an inner diameter ranging from (14,1 to 11,5) mm

The diameter of the return line is calculated as:

The return line starts from the valve base back to the tank Specifically, in the design of this press machine, there is a cooling system on the return line, so the return line is divided into 2 parts: one part from the valve base to the cooling system and one part from the cooling system to the oil tank We also choose the return line to be made of aluminum or cast iron with an inner diameter ranging from (12.6 to 9.9) mm

The pressure line is typically divided into two parts:

The first part runs from the power pump to the valve, which is entirely located above the oil tank Therefore, to enhance the aesthetics of the power pump, we use rigid pipes (usually cast iron) for this part The remaining part of the pressure line runs from the valve to the actuator, for which we choose flexible pipes

The diameter of the pressure line is calculated as:

So, we choose flexible and rigid pipes with inner diameters ranging from (7.2 to 5.6) mm and capable of withstanding pressure of about 180 bar to use as the pressure line for the system

To select the power pump for the system, we have the following assumptions:

 The length of the suction line is equal to the length of the return line : L1 = L3 = 2 (m)

 The length of the pressure line is: L2 = 4 (m)

 The velocity and diameter of the suction line v1 = 1 (m/s); d1 = 19(mm)

 The velocity of the pressure line v2 = 4(m/s); d3 = 10(mm)

 The velocity of the return line v3 = 1,5 (m/s); d2 = 19 (mm)

Based on the two pressure and flow rate parameters mentioned above, as well as the operating conditions of the system, we find that the gear pump is the most suitable choice because:

 The gear pump has a pressure range of p = 100 – 250 bar

 The gear pump has a suitable flow rate range Q < 100 (liters per minute)

The structure of the gear pump is compact, convenient for assembly and maintenance in the future

The gear pump has a relatively low cost compared to other types of pumps such as: radial piston pumps, axial piston pumps, vane pumps, etc

We choose a motor driving the pump with a speed of n45 (rpm) This is a very suitable speed for gear pumps Therefore, the specific flow rate of the pump is calculated using the formula: q = = , = 3,92 ( 𝑐𝑚/𝑟𝑒𝑣)

We can choose the power pump to be a gear pump with a specific flow rate q = 4 (cc) We select a 4 (cc) gear pump

With a specific flow rate q = 4 (cc) the pump flow rate is calculated according to formula 5.19 on page 83 of document [4]

The hydraulic power of the system is calculated according to formula :

Q : Flow rate of the pump (liters per minute)

To ensure the stability of the system and practicality, we choose the electric motor type: Motor 2 HP- 3Phase -380V

5.8.7 Selecting the Directional Control Valve:

Select a 4/3 hand-lever operated directional control valve.The valve is manually operated by a lever When controlling the valve to change positions, the piston or shaft inside the valve moves, altering the connections between the ports This allows the user to adjust the direction and pressure of the flow to devices that perform tasks, such as hydraulic cylinders

The flow rate through the directional control valve is the flow rate provided by the pump to the system; therefore, the directional control valve must ensure Q = 5,78 (liters per minute)

Figure 5.12 The symbol for a 4/3 hand-lever operated directional control valve 5.8.8 Selecting the Safety Valve:

The safety valve is a hydraulic component tasked with protecting the system in case of overload, such as when the cylinder is jammed causing a sudden increase in system pressure, leading to various incidents such as pump failure or pipe rupture

The working principle of the valve relies on the balance of opposing forces: the restoring force of the spring acting on the spool (or valve plug) with the force due to the pressure of the fluid flow

Depending on each system, its operation, and characteristics, the safety valve is set at different pressure values When the system pressure suddenly increases due to overload, causing the actuator to jam or fail, the safety valve will actuate, discharging fluid back to the tank until the pressure reaches the set value

Safety valves are divided into two types based on their operating principle: direct-acting and pilot-operated safety valves Pilot-operated safety valves are mainly used in systems with high flow rates and relatively high pressures

In the system, if the flow rate of the source pump is Q = 7,53 (liters per minute), then we select a direct-acting relief valve that is suitable for the design

5.8.9 Pressure Gauge and Gauge Cock Selection:

Select the type of pressure gauge with the maximum pressure rating: 350 kg/cm² Choose a corresponding gauge cock for the pressure gauge

Testing the bending process

Figure 5.13 Bending with a thickness of 4mm in Inventor software

Conclusion: Based on the testing and analysis in Inventor software, the chosen material is CT38 steel with a bending force of 34,000 N The area experiencing the highest stress is 267.4 Mpa greater than the yield strength of CT38 steel is 𝜎 #5 N/mm² and less than the limited durability is 𝜎 73 N/mm², indicating that it satisfies the bending strength condition of the steel.

Applying Inventor software to check the strength of the machine frame

Maximum force applied to the horizontal bar :

When simulating, the mass (kg) is converted to force (N) acting on the machine frame, and we have: 1 kg ~ 9.8 N

F is the reaction force that the U-shaped bar has to endure is :

Figure 5.14 Direction of the force acting on the machine frame

Figure 5.15 The stress of the machine frame

Based on Figure 5.18, we observe that the maximum stress of the frame is σmax = 154,3 (MPa) < [σb] = 481 (MPa) Therefore, the frame meets the durability requirements

Figure 5.16 The simulation results of testing the safety factor of the machine frame Comparison of the safety factor acting on the frame with the stress of CT38 steel:

K=1.94 > K=1.5 Therefore, the safety factor of the component is greater than the safety factor of the material, which is 1.5 so the safety factor is met

Figure 5.17 The simulation results for the displacement of the machine frame

From Figure 5.20, it can be seen that the maximum static displacement is 0,7935 mm based on the operating principle and the function of the machine's components Thus, the displacement will not significantly affect the relative positions and functionality of the machine

 Conclusion: Through the three testing processes, it can be observed that the machine frame is designed with sufficient strength to ensure stable operation

Using Inventor software to simulate the stress of a hole under an applied force

Figure 5.18 Direction of the applied force on the hole

Figure 5.19 The stress of the hole

Based on Figure 5.22, we observe that the maximum stress of the hole is σmax = 180.8 (MPa)

< [σb] = 481 (MPa) Therefore, the hole meets the durability requirements

Figure 5.20 The simulation results of testing the safety factor of the hole

Comparison of the safety factor acting on the hole with the stress of CT38 steel:

K=1,66 > K=1,5 Therefore, the safety factor of the component is greater than the safety factor of the material, which is 1.5, so the safety factor is met

Figure 5.21 The simulation results for the displacement of the hole

From Figure 5.24, it can be seen that the maximum static displacement is 0,01538 mm based on the operating principle and the function of the machine's components Thus, the displacement will not significantly affect the relative positions and functionality of the machine

MANUFACTURING AND EXPERIMENTATION

Manufacturing the Machine Frame

Figure 6.1 Machine Frame Designed in Inventor Software

Processing Steps: Cutting, Grinding, Drilling Holes, Welding, Painting

Materials: U-shaped steel 120x55x6,3 (mm) and V-shaped steel 60x60x6,3 (mm)

Figure 6.2 Drilling Holes on the Bench Drill Machine

Figure 6.3 Welding the U-shaped steel bars

Figure 6.4 Grinding the edges of the U-shaped steel bar

Figure 6.5 Welded joints after welding

Manufacturing the Punch and Die

Figure 6.6 Punch and Die Designed in Inventor Software Processing Steps: Metal Sheet Cutting, Milling, Drilling, Tapping, Painting

Materials: For the punch and die in the bending brake to ensure stiffness, accuracy, and bending angle, we use SKD11 steel with a thickness of 20mm for the Die and a thickness of 10mm for the punch

Figure 6.7 Machining the punch Component For the base used to assemble the mortar and pestle set, we use CT38 steel material with a thickness of 30 mm to ensure durability and optimize costs

Manufacturing the Workbench Support Components

Figure 6.9 Workbench Support Frame in Inventor Software Materials: U-shaped steel CT38 120x55x6 (mm)

Processing Steps: Cutting, Drilling, Assembling with bolts and nuts, Painting

Figure 6.10 Drilling Holes on the Bench Drill Machine

Machining of support pin

Figure 6.12 Round steel support pin in Inventor software Material: CT3 steel, round with a diameter of 20 mm

Processing Steps: cut and chamfer

Figure 6.13 Support pin after machining

Assembly Process

Figure 6.14 Assembling the Workbench Support Frame

Figure 6.15 The workstation is mounted onto the machine frame

Figure 6.16 Assembling the Punch and Die components onto the metal plate

Figure 6.17 The punch and die after assembly with the metal plate

Figure 6.18 The punch and die are connected to the machine frame

Figure 6.19 The hydraulic press machine after being painted.

Control System Design

Establishing an Overview Hydraulic Circuit Diagram

 The structure of the schematic diagram is as follows:

 Hydraulic power pump (1): Provides pressure and flow to the entire hydraulic system

 Safety valve (2): Ensures that the system pressure does not exceed the allowable value to protect the system components from damage and ensure compliance with design requirements

 Pressure gauge (3): Measures the pressure at the pump outlet to determine specific operating conditions for the pump in different situations

 4/3 directional control valve (4): This valve has four ports but operates in three positions

In the standby mode (no load), the valve remains in its initial position, allowing the oil to pass through and return to the reservoir

 Hydraulic cylinder (5): This is the actuating mechanism that generates the necessary force to compress materials

 Oil filter assembly (6): This assembly consists of a filter unit with a check valve set to a pressure limit Oil passes through the check valve when the filter unit operates beyond its permissible limit or becomes clogged

 Hydraulic reservoir(7): This component serves various purposes, including separating contaminants, expanding the fluid, cooling the fluid, and storing the fluid The hydraulic reservoir is made of welded steel plates and can be designed to be adaptable according to application needs

 The operating principle of the hydraulic press system:

The working principle is as follows:

Hydraulic fluid (mineral oil) from the reservoir (7) is transmitted to the piston cylinder (5) through a high-pressure pump (1) Depending on the material and strength of the steel, the high-pressure pump generates corresponding pressure When the 4/3 direction control valve (4) is activated by the lever, it will move the piston The piston is raised and lowered by the hydraulic pressure generated in the upper and lower chambers of the cylinder, creating a pressing force on the piston head When the hydraulic system pressure exceeds the set value, the relief valve (2) automatically opens to discharge the fluid back to the reservoir Thus, the cylinder and hydraulic motor operate smoothly, unaffected when the system starts

 Simple and easy to use: A manually operated hydraulic control system does not require complex electronic components, reducing costs and making it easy to use and maintain

 High reliability: Because there are no complex electronic components, hydraulic systems typically have high reliability and are less prone to breakdowns

 Requires operator strength: Due to the use of a lever to control, this system requires the operator to have the strength to operate, especially in applications requiring high pressure

 Lack of flexibility: Manually operated hydraulic systems are often less flexible than electronic control systems and cannot be programmed or automated.

Machine Finalization and Testing

Step 1: Perform a general inspection and prepare the machine, clean all surfaces that come into contact with the workpiece

Step 2: Install the bending tools onto the hydraulic press machine's workbench

Step 3: Adjust the position of the material to fit the mold and ensure the material is in the correct position before bending

Step 4: Activate the machine and monitor the bending process

Step 5: Inspect and make adjustments as necessary

Step 6: After completing the bending process, turn off the machine and inspect the product

Step 7: Clean the machine after use.

Experimentation Process

- Determine the optimal technical specifications and conditions: The experiment aims to identify technical parameters such as hydraulic pressure requirements, position, and angle of bending to achieve high-precision V-shaped products This includes finding the optimal working conditions for both the machine and the materials used

- Check the durability of the machine: Through experimentation, the durability and performance of the 10-ton hydraulic press machine can be evaluated during specific bending processes, helping to determine its continuous operation capability

- Test specimens preparation: CT38 steel with thickness ranging 4mm will be prepared for the experiment

 Hydraulic pressure testing: to determine the necessary hydraulic pressure for bending the V-shaped products This includes adjusting the pressure and recording the bending results to find the optimal point

 Bending mechanism of the punch and die: Assess the bending angle of the product as requested: 90 degrees

 Hydraulic pressure testing: Perform bending test on metal plates of the same thickness

Experiment with a metal sheet with a thickness of 4mm After experimenting, we proceed measure by hand measure the perpendicularity of the product using a specialized stainless steel square for precision mechanical processing The square is a stainless steel right angle square, L-shaped, manufactured in Germany

Figure 6.22 Eke is used to measure perpendicularity

Adjusting the hydraulic cylinder speed according to the original design, we proceed with bending with a workpiece measuring 133x65x4 (mm) with the material being CT38 steel under a pressure of 5 Mpa with the required bending angle is 90 degrees

Figure 6.23 Experiment of V-shaped pressing 1

Table 6.1 The data obtained after experiment 1 Conclusion: When observing the test product, we noticed that there was no gap between the measuring tool and the product, proving that the product achieved the desired 90 degree angle

Table 6.2 The data obtained after experiment 2 Conclude: Upon observing the tested product, we noticed there is still a gap between the measuring tool and the product, indicating that the product has not achieved the intended 90-degree angle

Table 6.3 The data obtained after experiment 3 Conclusion: When observing the test product, we noticed that there was no gap between the measuring tool and the product, proving that the product achieved the desired 90 degree angle

Adjusting the hydraulic cylinder speed according to the original design, we proceed with bending with a workpiece measuring 133x65x4 (mm) with the material being CT38 steel under a pressure of 5 Mpa with the bending angle is 90 degrees

Table 6.4 The data obtained after experiment 4 Conclusion: When observing the test product, we noticed that there was no gap between the measuring tool and the product, proving that the product achieved the desired 90 degree angle Experiment 5 :

Table 6.5 The data obtained after experiment 5 Conclusion: When observing the test product, we noticed that there was no gap between the measuring tool and the product, proving that the product achieved the desired 90 degree angle Experiment 6 :

Table 6.6 The data obtained after experiment 6 Conclusion: Observing and checking the product with a measuring tool, we see that there is a gap between the product and the measuring tool, so the product does not meet the bending angle requirement of 90 degrees

Inspect the product on the CMM machine

The 3D CMM (Coordinate Measuring Machine) is a type of 3D measuring device commonly used in manufacturing and quality inspection of products The CMM operates by using high-precision sensors to collect information about the position of points on the surface of the product Then, the software calculates the necessary parameters to assess the quality of the product

 High precision: CMM are equipped with high-precision sensors, providing more accurate measurements compared to other measuring devices

 Versatility: CMM can be used to measure products of various shapes and sizes They can be utilized in the automotive, aerospace, electronics, medical, and many other industries

 Time and cost savings: CMM can measure quickly and more accurately than traditional measurement methods This helps save time and cost in the production process

We proceed to take a standard-compliant sample with no gaps for testing on the CMM machine, and we obtain the following results:

Figure 6.47 The workpiece is positioned on the CMM machine

Figure 6.48 Proceed with measurements on the CMM machine

Figure 6.49 The results obtained after the measurement process on the CMM machine

 Conclusion: Based on the data images obtained after measuring the sample on the CMM machine, we observe that the measured angles for the outer plane and inner plane are 89.7732 and 90.2268 degrees, respectively Thus, with the measured results still falling within the allowable tolerance range of ±0.3 as initially set, the product meets the requirements

After processing to achieve the required 90-degree bending angle, the V-shaped details will be installed or replaced in the assembly of V-shaped parts that have become bent or warped during the operation of the spring roll wrapping machine of CODIA Industrial Solutions Company, meeting the company's maintenance and repair requirements

Figure 6.50 The product of the bending process is replaced into the machine

Experimental Evaluation and Conclusion

Target set : The V-shaped achieved a 90-degree bending angle

 The structure after bending does not exhibit any signs of cracks or uneven deformation, ensuring stability in structure and durability over time

 The surface of the product after bending is smooth, without waves or defects formed during the bending process, indicating that the mold manufacturing and bending process were executed precisely

 The machine setup and bending process were conducted swiftly, enhancing productivity

 The V-shaped products meet the requirements with a bending angle of 90 degrees.

Safety Measures and Maintenance of the Machine

 Do not place hands in the pestle and mortar area when the hydraulic press is in operation

 Check the hydraulic systems before operating

 The oil should be replaced after 5000 hours of operation, however, if it has not reached 5000 hours but has been used for a year, it should also be replaced

 It is necessary to regularly clean and flush the oil filter to avoid oil blockages

 Maintenance of pistons and hydraulic cylinders

 Check the cylinder clamping bolts to the machine body as a precaution against the continuous pressing force causing instability during operation, which could cause the bolts to loosen, compromising the stability of the joint and leading to the breakdown of the original position

After a period of research and execution of the project "DESIGN, MANUFACTURE HYDRAULIC PRESSING TOOLS TO SUPPORT MAINTENANCE AND REPAIR FOR CODIA INDUSTRIAL SOLUTIONS COMPANY," with the dedicated assistance of our supervising lecturer and CODIA Industrial Solutions LLC, our group has successfully completed our graduation project and achieved the following results:

 Gained understanding of the hydraulic press manufacturing process

 Explored the various types of pressing machines available on the market

 Design and manufacture punch and die assembly

 Researched and proposed design solutions for the machine

 Designed and tested with 2D and 3D design software

 Machined, assembled, and finalized the machine

 Conducted experiments and product testing

Although there are still some limitations that need to be addressed, our team has the following recommendations to overcome the shortcomings of the machine:

 Study the development of an automated worktable lifting system that does not require manual labor Implementing such a system would improve efficiency and reduce the need for human effort

 Investigate the manufacturing of a punch and die assembly to machine various metals with different thicknesses

[1] Tôn Yên,Công Nghệ dập nguội,Nhà Xuất Bản Khoa Học Kỹ Thuật Hà Nội ,1974

[2] Thép hình cán nóng - Kích thước - Dung sai - Đặc tính mặt cắt (ISO 657-1:1989), p.20Tiêu chuẩn Việt Nam (TCVN) 7571-1:2006

[3] Nguyễn Đình Đức và Đào Như Mai Giáo trình Sức bền vật liệu và kết cấu NHÀ XUẤT BẢN ĐẠI HỌC QUỐC GIA HÀ NỘI HÀ NỘI – 2012

[4] PGS Trần Xuân Tùy, Ths Trần Minh Chính, Ks Trần Ngọc Hải, Giáo trình hệ thống truyền động thủy khí và khí nén, Trường ĐHBK Đà Nẵng

[5] ThS.Trần Quốc Hùng, giáo trình dung sai – kỹ thuật đo NHÀ XUẤT BẢN ĐẠI HỌC QUỐC GIA THÀNH PHỐ HỒ CHÍ MINH

[6] Hồ Viết Bình – Phan Minh Thanh, Giáo trình Công nghệ chế tạo máy, Nhà xuất bản Đại học quốc gia TP Hồ Chí Minh, năm 2013

[7] Nguyễn Tắc Ánh, Giáo trình Công nghệ kim loại –, Đại học Sư phạm Kỹ thuật, năm

[8] Nguyễn Thành Trí (2006), Hệ thống thủy lực trên máy công nghiệp, NXB Đà Nẵng [9] GS-TS Trần Hữu Quế, Vẽ kỹ thuật 1,2, NXB Giáo Dục 2009

[10] Suraj kumar Vishwakarma, Nitin Kumar Gupta, Advancement Of Pressure Switch Hydraulics Press Machine, Volume 6, Issue 2 April 2018 / ISSN: 2320-2882

[11] Nguyễn Phú Bình, Bài giảng môn học sức bền vật liệu link: https://ebookxaydung.com/sanpham/bai-giang-suc-ben-vat-lieu-nguyen-phu-binh/

[12] Nathaniel Marc Brown, Hydraulic Hand Press Final Project Report page 29-40, Mechanical Engineering Department California Polytechnic State University San Luis Obispo, December 3nd, 2009 link: https://digitalcommons.calpoly.edu/mesp/5/

[13] Gia Công Kim Loại Bằng Áp Lực link: https://smartsheetmetal.com.vn/tin-tuc/gia- cong-kim-loai-bang-ap-luc-dac-diem-va-nhung-phuong-phap-co-ban.html

[14] Gia công uốn trong cơ khí link: https://kythuatchetao.com/bien-dang-uon-trong-co-khi/

[15] Nguyễn Tiến Dũng, Nghiên cứu ảnh hưởng của áp lực ép trong quá trình tạo hình gạch đất không nung theo phương pháp ép bán khô, tạp chí Khoa học Công nghệ Xây dựng NUCE 2018 link: https://stce.huce.edu.vn/index.php/vn/article/view/1255/630

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