Design, Manufacturing Broaching Machine Of Keyway With Long Length.pdf

MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION DESIGN, MANUFACTURING BROACHING MACHINE OF KEYWAY WITH LONG LENGTH S K L 0 1 2 6 3 0 GRADUAT

MINISTRY OF EDUCATION AND TRAINING

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

DESIGN, MANUFACTURING BROACHING MACHINE OF

KEYWAY WITH LONG LENGTH

S K L 0 1 2 6 3 0

GRADUATION THESIS MACHINERY MANUFACTURING TECHNOLOGY

INSTRUCTOR: PH.D MAI DUC DAI

ME NGUYEN DUY TRINH STUDENT: CU NHAT KHANH

TRAN NGUYEN GIA KHANH DANG THANH PHONG

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY

AND EDUCATION FACULTY OF MECHANICAL

ENGINEERING

DEARTMENT OF MACHINERY MANUFACTURING

TECHNOLOGY

GRADUATION THESIS

DESIGN, MANUFACTURING BROACHING MACHINE OF

KEYWAY WITH LONG LENGTH

LECTURER: PH.D MAI DUC DAI

ME NGUYEN DUY TRINH STUDENT’S NAME: CU NHAT KHANG

KHOA CƠ KHÍ CHẾ TẠO MÁY CÔNG HÒA XÃ HỘI CHỦ NGHĨA VIỆT NAM

BỘ MÔN THIẾT KẾ MÁY Độc lập - Tự do - Hạnh phúc

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Tp Hồ Chí Minh, ngày…….tháng……năm 2024

NHIỆM VỤ ĐỒ ÁN TỐT NGHIỆP

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(Ký & và ghi rõ họ, tên) (Ký & và ghi rõ họ, tên)

KHOA CƠ KHÍ CHẾ TẠO MÁY CÔNG HÒA XÃ HỘI CHỦ NGHĨA VIỆT NAM

BỘ MÔN THIẾT KẾ MÁY Độc lập - Tự do - Hạnh phúc

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Tp Hồ Chí Minh, ngày tháng năm 20

Giáo viên hướng dẫn

( Ký & ghi rõ họ tên)

KHOA CƠ KHÍ CHẾ TẠO MÁY CÔNG HÒA XÃ HỘI CHỦ NGHĨA VIỆT NAM

BỘ MÔN THIẾT KẾ MÁY Độc lập - Tự do - Hạnh phúc

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BẢNG NHẬN XÉT CỦA GIÁO VIÊN PHẢN BIỆN

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Tp Hồ Chí Minh, ngày tháng năm 20

Giáo viên phản biện

( Ký & ghi rõ họ tên)

First of all, my group would like to express our sincere thanks and deepgratitude to the teachers of Ho Chi Minh City University of Technical Education,especially the teachers of the Department of Machine Manufacturing Technologyfor their contributions diligently imparting useful knowledge to help our groupcomplete today's project and that is also an important foundation to help us becomeengineers in the future

The team would like to send our sincerest thanks to:

Mr Nguyen Duy Trinh directly and enthusiastically guided the group to helpthem complete the project Mr Trinh always actively answers the group's questionswhen the group encounters difficulties during work Mr Trinh shared hisprofessional knowledge so that the group could successfully complete this project

Teacher Mai Duc Dai guided the group to complete the requirements in thegraduation project assignment The teacher also supported the group in solvingproblems in the presentation stage so that the group could complete it well

Finally, the group would like to send our deep thanks and gratitude to ourfamily and friends who have always stood by our side, encouraged us, andaccompanied us throughout the past 5 years of school This achievement will never

be achieved again without the support of family and relatives Thank you verymuch

TÓM TẮT ĐỒ ÁN

Với xu thế tự động hóa trong công nghiệp Các máy móc dần thay thế conngười trong việc sản xuất Con người chỉ việc điều khiển, đưa ra lệnh và máy móclàm theo những lệnh đó Với các đặc tính ưu việt của máy chuốt mà các sản phẩmliên quan đến lĩnh vực rãnh then càng được ứng dụng rộng rãi trong đời sống cũngnhư trong công nghiệp do đó nhu cầu để làm ra các máy chuốt chế tác các sảnphẩm có rãnh then lớn cũng tồn tại theo Máy chuốt sẽ giảm thiểu khả năng gá đặt

và sai số cắt, đặc biệt là có thể gia công rãnh then trong với những chi tiết dạng trụ

có chiều dài lớn Tên đề tài là “ Thiết kế, chế tạo máy gia công rãnh then có chiềudài lớn” Mục tiêu chính của đề tài là thiết kế chế tạo máy chuốt rãnh then hình chữnhật với kích thước 0.24 x 0.054 inch và có chiều dài rãnh là 23.165 inch

Từ những mục tiêu của đề tài, nhóm chúng em tìm ra những nguyên lý máysao cho nguyên lý đơn giản nhất, hoạt động ổn định nhất và chi phí chế tạo phảihợp lý Từ đó chọn ra một nguyên lý tối ưu nhất để thực hiện Trong đề tài này sẽ

có 3 vấn đề chính cần giải quyết đó là: thiết kế kĩ thuật của máy, tính toán chọnđộng cơ motor và xy lanh thủy lực, thiết kế và chế tạo dao chuốt để có thể gia côngkích thước được rãnh then theo thông số đầu vào yêu cầu Tính toán, thiết kế vàkiểm nghiệm bền trên khung máy Từ đó chế tạo, thiết kế máy và dao chuốt hoànchỉnh

Sau 5 tháng thực hiện đề tài tuy gặp nhiều khó khăn nhưng nhóm chúng em

đã hoàn thành được mục tiêu đề ra và đạt được những kết quả như sau:

- Hoàn thành được sản phẩm là máy chuốt, máy hoạt động ổn định, độnhám bề mặt của rãnh then đạt được độ bóng theo yêu cầu, dung saikích thước của rãnh then phù hợp với mục tiêu ban đầu

- Tính toán và thiết kế được dao chuốt

- Kiểm nghiệm độ bền của khung máy

Điều này chứng tỏ các nguyên lý trước đó mà nhóm chúng em đưa ra vàtham khảo với giảng viên hướng dẫn là hợp lý Tuy nhiên kiến thức của chúng emvẫn còn hạn hẹp nên không thể tránh khỏi, chúng em hy vọng rằng các quý độc giả

sẽ thông cảm và góp ý cho nhóm chúng em có thể có cái nhìn tốt hơn và hoàn thiệnhơn về đề tài này

Nhóm sinh viên thực hiện xin chân thành cảm ơn

With the trend of automation in industry Machines gradually replacedhumans in production Humans just control and give commands and machinesfollow those commands With the preeminent characteristics of the broachingmachine, products related to the key groove field are widely applied in life as well

as in industry Therefore, the need to make broaching machines for makingproducts with large keyways also exists The broaching machine will minimize thepossibility of jigs and cutting errors, especially can process internal key grooves

with large length cylindrical parts The name of the topic is "Design and manufacture a key groove processing machine with a long length" The main

objective of the project was to design and manufacture a rectangular key groovebrochure with dimensions of 0.24 x 0.054 inches and a groove length of 23.165inches

From the objectives of the project, our team found out the principles of themachine so that the principle is the simplest, the most stable operation and themanufacturing cost must be reasonable From there, choose the most optimalprinciple to implement In this topic, there will be 3 main problems to solve:technical design of the machine, calculation of motor and hydraulic cylinderselection, design and manufacture of broaching knives to be able to process thesize of the key groove according to the required input parameters Calculation,design and durability testing on chassis From there, fabricate and design completemachines and broaching knives

After 5 months of implementing the project, although facing manydifficulties, our team has achieved the set goals and achieved the following results::

- Completing the product is a broaching machine, the machineoperates stably, the surface roughness of the key groove achieves therequired gloss, the dimensional tolerance of the key groove issuitable for the original goal

- Calculate and design the broaching knife

- Chassis durability tests

This proves that the previous principles that our team put forward andconsulted with the instructor are reasonable However, our knowledge is stilllimited so it is inevitable

Acknowledgement………

Tóm tắt đồ án………

Asbtract………

Contetnt………

List of figure………

List of table………

Chapter 1: Overview………

1 Keyway in the hole - Application:………

1.1 Keyway definition:………

1.2 The location of the keyway on the component………

1.3 Application:………

2 Keyway broaching technology:……… …

2.1 Advantages:………

2.2 Disadvantages……….………

2.3 Principle of broaching………

3 Broaching machines and equipment :.………

3.1 Domestic equipment:………

3.2 Imported Equipment:………

4 Research Objectives:………

5 Research Approach:……….………

5.1 Operating principle of vertical broaching machine…………

5.2 The operating principle of the horizontal broaching machine 5.3 Related to the graduation thesis.:……….………

6 The urgency of the topic.:………

Chapter 2: Theoretical Foundations………

1 Principle of metal cutting and machining of broaching:………

vi vii viii ix xiv xvii 01 01 01 02 02 03 03 03 03 04 04 06 08 08 09 10 11 12 14 14

1.1 Broaching principle:………

1.2 Structure of tool's Broaching:………

1.2.1 Tool’s Broaching:………

1.2.2 Geometric parameters of tool broaching:…………

1.2.3 Forms of broaching:……….…

1.3 Calculate cutting condition:………

1.3.1 Feed rate and cutting thickness:………

1.3.2 Cutting speed of broaching:………

1.3.3 Calculate cutting force:………

1.3.4 Cutting capacity:………

2 Basis for calculating and designing weak links in the machine::……

2.1 Basic theory of material strength:………

2.2 Problem of material strength of bars subjected to tension…

2.3 Material strength problem of bending beams:………

3 Basis for calculating hydraulic xylan:………

3.1 Formula to calculate xylan diameter………

3.2 Some quantities in the hydraulic transmission calculation… 3.3 Some calculation formulas in hydraulic problems:…………

4 Control………

4.1 Electrical elements………

4.1.1 Thermal relay………

4.1.2 Intermediate relays………

4.1.3 Electric switch……… ………

4.1.4 Electric fuses………

4.2 Control buttons……….…

4.2.1 Hold button………

4.2.2 Emergency stop button………

14 14 14 16 16 18 18 19 19 22 22 22 23 24 25 26 26 27 29 29 29 30 31 32 33 33 34

4.2.3 Rotating putton……….

Chapter 3: Technical design………

1 Input data………

2 Propose the principle plan of the machine………

2.1 Option 1………

2.2 Option 2………

3 Calculate the technical resistance of the working shaft………

3.1 Set up………

3.2 Cutting force………

3.3 The tightening force required to hold the part………

3.3.1 Force analysis diagram………

3.3.2 Create a balanced equation………

4 Calculation and preliminary selection of hydraulic equipment……

5 Choose electric motor and hydraulic pump………

5.1 Choose Motor………

5.2 Choose hydraulic pump………

Chapter 4: Design of the tool broaching component………

1 Choose Insert………

1.1 Input data………

1.2 Insert ………

1.2.1 Insert material………

1.2.2 Geometric profile of insert………

1.2.3 The screw tightening force of the insert………

2 Calculation and design of broaching tool handle………

2.1 Input data………

2.2 Design of the broaching tools………

2.2.1 Shape of the broaching tool:………

35 37 37 37 37 39 41 41 42 44 44 45 46 46 46 47 49 49 49 49 49 50 52 53 53 53 53

2.2.2 Materials of broaching tools……….

3 Design supported part………

3.1 Purpose………

3.2 Technical drawing………

3.3 Manufactured part………

Chapter 5: Calculating the frame machine design………

1 Input data………

1.1 Input data………

1.2 Preliminary geometric design:………

2 Frame design………

2.1 Material frame………

2.2 Technical design drawings.………

3 Durable Tests………

Chapter 6: Experimentation, evaluation of results………

1 Standard for check………

1.1 Technical drawing part………

1.2 Standard for check………

1.3 Measuring instruments………

2 Experimental Results and Discussion.………

2.1 Experimental results of keyway width………

2.2 Experimental results of cutting depth of keyway………

2.3 Experimental results of measuring the surface roughness of the keyway………

Chapter 7: Conclusion and development direction………

1 Conclusion:………

1.1 Results of achivement………

1.2 Limitations………

56 56 56 56 63 67 67 67 68 68 68 69 69 73 73 73 73 73 75 75 76

77 80 80 80 80

1.3 Conclusions………

2 Development direction………

References………

Appendix………

81 81 83 85

LIST OF FIGURE

Figure 1.1 The cross-sectional profile of the keyway groove………

Figure 1.2 The cross-sectional profile of the flower keyway

Figure 1.3 The cross-sectional profile of the semicircular keyway

Figure 1.4 The cutting process of the broaching tool and the material………

Figure 1.5 Vertical hydraulic broaching machine………

Figure 1.6 Vertical broaching machine TH-3x600………

Figure 1.7 Horizontal servo broaching machine CCLC-T10-SF-WF…………

Figure 1.8 Vertical hydraulic internal broaching machine………

Figure 1.9 Schematic diagram of the operating principle of a vertical broaching machine………

Figure 1.10 The schematic diagram of the horizontal chasing machine operating principle………

Figure 2.1 Simulation diagram of broaching principle………

Figure 2.2 Structure of tool's Broaching………

Figure 2.3 Rake angle, clearance angle and cutting edge……… ……

Figure 2.4 Internal forces in detail………

Figure 2.5 Stress is calculated in the problem of bars subjected to compression and tension………

Figure 2.6 Piston extending……….…

Figure 2.7 Thermal relay LS MT – 32 (22-32A)………

Figure 2.8 RXM2LB2P7 5A,2C/O 230VAC………

Figure 2.9 Manual circuit breaker MCB LS BKN-b 20A 10kA 3P………

Figure 2.10 RT 18-32 fuse………

Figure 2.11 Schneider hold down button……… ……

Figure 2.12 Emergency stop button ………

Figure 2.13 Rotary switch ……… ….……

01 01 02 04 05 06 07 07

09 10 13 15 16 23

24 27 30 31 32 33 34 35 36

Figure 3.2 Location to calculate clamping force………

Figure 3.3 Force analysis diagram

Figure 3.4 Motor YungShun

Figure 3.5 140CC gear pump

Figure 4.1 Insert demension specifications

Figure 4.2 Table of screw tightening force according to TCVN 1916

Figure 4.3 M5 Screws

Figure 4.4 Types of broach tools handles

Figure 4.5 Design drawing of a broach tool

Figure 4.6 Connecting rods

Figure 4.7 Connectors

Figure 4.8 Connector ………

Figure 4.9 Coupling

Figure 4.10 Guibushing

Figure 4.11 Thread protection sleeve …

Figure 4.12 Posittion locating………

Figure 4.13 Plastic locating

Figure 5.1 Preliminary geometry of the frame broaching

Figure 5.2 Frame design drawing

Figure 5.3 Meshing the frame

Figure 5.4 Choosing a material for the frame

Figure 5.5 Placing force on the frame

Figure 5.6 Stress simulation results

Figure 5.7 Displacement simulation results …

Figure 6.1 Detailed technical drawings

Figure 6.2 Standard measuring pin

41 44 44 47 48 52 52 53 54 55 57 58 58 59 60 61 62 63 64 66 66 67 67 68 68 69 70

Figure 6.3 Calibrated Bore Gage Figure 6.4 Surface Roughness Measuring Machine

7071

LIST OF TABLE

Table 2.1: Tool feed table based on machined material

Table 2.2: Cutting force P per 1mm cutting length

Table 4.1 Common types of Insert profiles …

Table 4.2 Processing and manufacturing parts………

Table 5.1 Table of chemical composition of CT3 steel

Table 5.2 Table of physical properties of CT3 steel

Table 7.1 Results table, evaluation of key groove cutting width measurement Table 7.2 Table of results, evaluation of measurement of keyway cutting depth………

Table 7.3 Result table , evaluation of keyway surface roughness measurement………

18 20 50 63 65 65 79 80 81

There are various types of keyways on bores, including:

Rectangular keyway: A keyway with a rectangular cross-sectionalprofile

Figure 1.1 The cross-sectional profile of the keyway groove

Flower keyway: A keyway with a floral-shaped cross-sectional profile

Semicircular keyway:

Figure 1.3 The cross-sectional profile of the semicircular keyway

1.2 The location of the keyway on the component:

The position of the keyway on the component is typically located onthe shaft, rotating body, gear surface, depending on the detail and designapproach to ensure these joints can provide better concentricity forcomponents mounted on the shaft, improved load-bearing capacity, andhigher reliability in operation

1.3 Application:

The applications of keyways on bores are highly diverse, including:

- Guiding oil or fluid flow: They facilitate the efficient transfer of oil orfluid from one point to another

- Friction reduction: reducing friction between contacting surfaces Forexample, in bearing applications, keyways can facilitate the spread oflubricating oil and reduce friction between the roller and the bearingsurface

- Increasing contact area: Increasing the contact area between surfaces,improving stability or heat exchange

- Connecting machine components in industrial applications: Keyways arecommonly used to securely and precisely connect various types of tools

to shafts, gears, sprockets, gearboxes, etc., ensuring both stability andaccuracy

2 Keyway broaching technology.

Broaching technology is a mechanical machining method used tocreate keyways or complex-shaped holes on metal components

- Good surface quality: The keyway and hole surfaces after machiningtypically exhibit a good surface finish ��= 0.63 ÷ 0.32 µm

- Material saving in machining: Minimizes machining allowance compared

to other broaching methods

- Suitable for complex shapes: Can machine products with complexgeometries that other machining methods may struggle to achieve

2.3 Principle of broaching.

- Broaching is a metal machining method that utilizes a multi-toothedbroaching tool to cut and shape metal to achieve desired product formsand sizes, as depicted in Figure 1.4 The basic motion principle involveslinear motion either vertically or horizontally of the broaching tool or theworkpiece, although sometimes broaching may involve combined linearand rotational motions.

Figure 1.4 The cutting process of the broaching tool and the material[4]

3 Broaching machines and equipment

3.1 Domestic equipment

The current situation of manufacturing and using broachingmachines for keyway grooves in Vietnam is experiencing positivedevelopments

Currently, there are several domestic enterprises manufacturingbroaching machines, including:

- Vietnam Machine Tools Corporation Limited (Vinamachinery)

- Nam Dinh Mechanical Machinery and Equipment CorporationLimited (Nam Dinh Machinery)

- Hanoi Precision Mechanical Engineering Corporation Limited(Hanoi Precision Machinery)

The types of broaching machines domestically include:

Figure 1.5 Vertical hydraulic broaching machine (Pull type)

Figure 1.6 Vertical broaching machine TH-3x600

3.1.1 Advantages

- Easy accessibility: Broaching machines and tools are readily accessibleand available for purchase in the Vietnamese market There are manymanufacturers providing these products, facilitating easier procurementand maintenance

- Affordable prices: Some broaching machines and equipment aremanufactured domestically or imported at prices that are suitable for thebudgets of manufacturing enterprises in Vietnam

3.1.2 Disadvantages

- Lower reliability: Some domestically manufactured machines and toolsmay not meet high-quality standards like imported products fromdeveloped countries, and their durability may be lower in terms oflifespan compared to imported broaching machines

- Lack of diversity: Despite developments, the industrial machinery market

in Vietnam still lags behind in terms of technology compared to moredeveloped markets

3.2 Imported Equipment

With broaching technology abroad, the manufacturing andutilization of broaching machines are highly diverse and have madesignificant advancements compared to domestic ones

Foreign companies capable of manufacturing and producing broachingmachines include:

- Sunrise Mechatronics Techonology company ( Nanjing)

- Timeway Machine Tool company (China)

- Shanghai Bomar Industrial company (China)

- Chengchun Automation Equipment company (China)

Types of broaching machines overseas include:

Figure 1.7 Horizontal servo broaching machine CCLC-T10-SF-WF

Figure 1.8 Vertical hydraulic internal broaching machine

3.2.1 Advantages

- Typically, they offer high quality and optimal performance duringoperation

- They feature advanced technology and capabilities, enhancingproductivity and product quality.

- More reliable and less prone to breakdown compared to domesticequipment

3.2.2 Disadvantages

- Higher cost compared to domestic equipment

- Access and technical support may be challenging due to distance anddependence on foreign manufacturers

- Maintenance costs and component replacement expenses may also behigher

4 Research Objectives

- Propose the working principle of the machine, calculate the technicalresistance force of the working part, and select the driving cylinder forthe cutting tool

- Calculate the design of the broaching tool assembly, including thebroaching head, selection of suitable cutting tools, and the tool holderconnecting the broaching head to the broaching machine

- Machine frame design

- Fabrication of a prototype broaching machine

- For the broaching machining option, there are many broachingmachines available on the market capable of machining various types ofkeyways, such as floral keyways, rectangular keyways, and othercommon keyway types.

Common classifications of broaching machines include:

- Vertical broaching machines

- Horizontal broaching machines

5.1 Operating principle of vertical broaching machines

Figure 1.9 Schematic diagram of the operating principle of a vertical

- When broaching in reverse from bottom to top, the cutting tool clampsonto console (1) and sliding table (3) moving from bottom to top Theassembly detail within the machine table (4).

- When broaching in the forward direction from top to bottom console (3)and the compression clamping table from top to bottom, so thecompression and bending of the broaching tool, the part is placed on thedigital machine table (4)

- Electric motor (6) Transmission for the hydraulic mechanism inside themachine body (5) lever arm (7) and (8) in order to control the machine.[7]

According to the operating principle as above, the vertical chasingmethod can produce good quality products, but it is not optimized formachining products with high length

5.2 The operating principle of the horizontal broaching machine

Figure 1.10 The schematic diagram of the horizontal chasing machine

5- The mechanism for mounting the blade

6- Broaching tool

7- The face of the head (used for standardization)

8- Outer support (supports workpiece and broaching blade)

9- Inner support (supports piston shaft)

Working principle: The chasing blade undergoes a straighttranslational motion, while the hydraulic pump delivers high-pressure oilinto the left chamber of the cylinder to push the piston out (or in) to performthe product machining process The hydraulic system (flow control valve) isutilized to adjust the chasing speed, and the relief valve is incorporated toensure that the working efficiency does not exceed the limit [7]

So, comparing the operating principles of horizontal and vertical chasingmachines as well as various types of chasing machines on the market today,horizontal chasing machines have several advantages:

- It can process products with large lengths

- The cost of this machine is often much cheaper than that of verticalbroaching machines available today

- Components and broaching blades can be easily installed and removed

5.3 Related to the graduation thesis.

Currently, various types of chasing machines available on the market havevery high costs, such as:

- Vertical broaching machines (ranging from 43.000 US$)

- Horizontalbroaching machines(ranging from 30.500,US$)

- CNC broaching machines ( ranging from 175.000 US$)

Therefore, in order to machine cylindrical products with an outerdiameter 2.71~2.72 inch, inner diameter 1.975~1.989 inch, and groovelength 20~22.4 According to single-piece orders, it is necessary to design

and manufacture chasing machines and chasing blades to optimize botheconomically and meet the company's needs.

In addition, when designing and manufacturing chasing machinesand chasing blades, we can also be more proactive in terms of currentchasing technology

6 The urgency of the topic.

The thread chasing machine is a type of mechanical machining equipmentused to create threads on metal parts and is widely applied in variousindustries, including automotive manufacturing, aerospace, etc

- Response production demands: The demand for manufacturingmechanical parts with threaded grooves Thread chasing machines areone of the most efficient machining methods to create these parts

- Enhance productivity and product quality: Parts can be machined withhigh precision and fast processing speed

- Cost savings: Save on product processing time and labor needed forthe machining process,

In reality, Vietnam is still importing the majority of thread broachingmachines from foreign countries This poses many disadvantages fordomestic manufacturing enterprises, including:

- Costly import expenses: The imported thread chasing machines oftencome with higher prices compared to those produced domestically

- Dependence on foreign sources: When thread chasing machines breakdown, businesses often require significant time and expense to repair

or replace them, as they rely on foreign suppliers

- Limitation on technology innovation: Businesses cannot activelyinnovate machining technology without appropriate thread chasingmachines

Therefore, researching, designing, and manufacturing thread chasingmachines domestically is highly necessary This will help domesticmanufacturing enterprises enhance productivity, product quality, costsavings, and be more proactive in current thread chasing technology.

With the development of technology, thread chasing machines willundoubtedly continue to be improved and widely applied in variousindustries Therefore, the topic of manufacturing thread chasing machineshas high potential for application and brings many benefits to domesticmanufacturing enterprises

CHAPTER 2: THEORETICAL FOUNDATIONS

1 Principle of metal cutting and machining of broaching:

1.1 Broaching principle:

The basic principle of the broaching process is to use a broaching knife withmany teeth or cutting blades to remove layers of material from the surface of thework piece to create the desired shape and size.[7]

The main movement when broaching is translational movement in onedirection, in addition there is also rotational movement if it is key broaching Whenbroaching, the broaching knife will be pulled across the machined surface by axylander to remove the material layer The teeth or cutting edges on the broachingknife will create high cutting force to remove material.[7]

Broaching principle diagram:

Figure 2.1 Simulation diagram of broaching principle

1.2 Structure of tool's Broaching:

1.2.1 Tool’s Broaching:

Tool's Broaching is a tool with many cutting blades Depending onthe shape and surface of the hole, it can have many shapes such as round,square, steel, and six-sided broaching tools.[8]

Structure of tool's Broaching:[8]

Figure 2.2 Structure of tool's Broaching + Part 1: The tool head is used to clamp the tool broaching.

+ Part 2,3: Tool collar and transition taper

+ Part 4: The front guide centers the part before broaching,protecting the broaching knife teeth from breaking when overloaded

+ Part 5: The cutting blades part is responsible for cutting allthe remaining teeth with diameters increasing by an amount of Sz Onthe cutting teeth there are grooves that divide the chip into smallsegments (chip dividing grooves on the front and rear teeth arearranged).interlayer) thereby reducing shear layer deformation andcutting force

+ Part 6: The part corrects the hole size and increases themachining gloss This part has from (4 ÷ 8) teeth, the same diameterequal to the size of the machining hole and has no chip dividinggroove

+ Part 7: The rear guide is responsible for orienting the detail

1.2.2 Geometric parameters of tool broaching:

To be able to make a broaching knife, we need to pay attention

to three quantities: the rake angle γ, the clearance angle α and thecutting edge f [8]

Figure 2.3 Rake angle, clearance angle and cutting edge

a Rake angle γ:

- The cutting angle γ = 5 ÷ 20o depending on the processingmaterial

- Correct the angle γ: γ = 0 ÷ 5o so that the tool diameter will

be reduced when re-sharpening

b Clearance angle α:

- Clearance angle α: α = 1 ÷ 3o

- Correct clearance angle: α = 1 ÷ 2o

- External tool broaching have α = 5 ÷ 10o because theprocessing size can be adjusted

c Cutting edge f:

- To increase the life of the sharpener on the correct repair part,the cutting edge is made f ≤ 0.2mm

1.2.3 Forms of broaching:

Depending on the shape, accuracy and size of the machinedpart and the state of the workpiece, we use appropriate broachingforms

Forms of sharpening affect the load distribution on teeth andtool durability People use the following 3 forms of sharpening:[8]

a Form of broaching in layers:

- The cut alloy layer has a tool path that is identical to the toolpath of the machined part

- Advantages: Ensures high gloss and accuracy

- Disadvantages: Tools are complicated to manufacture, highcutting force

b The form of sharpening gradually remove:

- The tool path of the cutting layer and the tool path of thecutting teeth are not the same as the tool path of the machinedsurface, the last teeth have the shape of the machined surface

- Advantages: Tool is simple to make

- Disadvantages: The gloss and accuracy are lower than withlayer broaching because the machined surface between the twocutting layers has cuts created by separate teeth

c Form of sharpening in pieces:

- Similar to a gradual broach, but each layer of metal is cut by

a group of teeth (2÷3 teeth)

- Advantages: Small cutting layer width, increased cuttingthickness, small cutting force applied to the tool

- Disadvantages: Because the cutting layer is thick, the knifeeasily wears the front surface, the tool is complicated to make,this method is used for parts with hard shells, thin walls, andpoor rigidity.

1.3 Calculate cutting condition:

1.3.1 Feed rate and cutting thickness:

The feed rate of broaching Sz is the size difference betweentool teeth That is the factor that creates a broaching tool.[7]

The feed rate can be selected based on the material and worktype:

Table 1: Tool feed table based on machined material

Copper,brass

Round broaching

tool

0.015-0.06 0.03-0.1 0.02-0.05 0.05-0.12

Broaching tool with

flower key, square

key, triangle key

0.03-0.16 0.05-0.12 0.04-0.1 0.06-0.12

Flower key

broaching

0.05-0.12 0.05-0.2 0.05-0.08 0.08-0.2

Square and

six-sided broaching tool

0.02-0.15 0.05-0.2 0.03-0.15 0.05-0.2

The cutting thickness will be selected depending on the feed rate Usuallythe cutting thickness will be in the range of (0.02 ÷ 0.2)mm Forflexible,lessdurable materials, you should choose a smallcutting thickness and vice versa.

1.3.2 Cutting speed of broaching:

The cutting speed is determined according to the requirements ofmachining accuracy and surface roughness When cutting at standard cutting speeds,the given face roughness can be achieved when the rake angle and clearance angleare reasonable and have transition teeth The formula to calculate speed is:[8]

V = Cv

Tm∗ Szy (1)Where:

V: Cutting speed (m/min)

��: Characteristics of cutting conditions whenbroaching

T: Tool durability is calculated based on machine time

Sz: Feed rate

To determine the coefficients and exponents Cv, m and y, we mustrely on the processing material and processing type, look up in table 1-4 of thedocument [8]

1.3.3 Calculate cutting force:

Formula to calculate cutting force of broaching:[8]

�� = � ∗ ��(2)Where:

��: Cutting force (N)

�: Cutting force per 1mm of cut length (N)

��: The maximum total work length of the cutting edge

HB ≤

197

HB=

229

198-HB

>

229

HB ≥197

HB=

229

198-HB >

229

GrayHB

0.18 39.5 43.6 52.0 52.5 56.5 62.0 33.4 37.0 30.20.20 42.7 47.3 56.2 57.6 62.0 68.5 36.0 40.2 32.60.22 45.6 50.3 60.0 62.0 66.2 73.8 38.5 42.7 34.90.25 49.5 54.5 65.0 68.0 73.0 81.0 42.1 46.5 37.60.30 56.4 61.5 73.0 78.5 84.5 93.3 47.6 52.2 43.1

Σb is the maximum total work length of the cutting edge of all teethdetermined by the formula:

+ When broaching the cylindrical surface:[8]

�� = ���

� ∗ 360� ∗ �1 (3)+ When broaching keyway and keyway:[8]

�� =���

� ∗ �1 (4)Trong đó:

bn: Width of broaching surface (mm)

��: The maximum total work length of thecutting edge of all teeth

d : Maximum machining diameter of teeth (mm)

Zv: The coefficient is selected according to thecutting diagram

β : Contact angle of the machining surface withthe cutting edge of the broaching tool teeth - forcylindrical hole broaching, β = 180o

�1 =��, where l is the length of the broachingsurface (mm); t is the tooth pitch (mm)

1.3.4 Cutting capacity:

The power when broaching is determined by the formula:[8]

N = 60 ∗ 102Pz∗ V (5)

Where:

N: is the cutting power (kW)

Pz: is the cutting force of broaching (N)V: cutting speed (m/min)

After calculating the cutting capacity, based on that we can choose amotor with the appropriate capacity for the working machine

2 Basis for calculating and designing weak links in the machine:

2.1 Basic theory of material strength:

During the design process of weak links in the machine, durabilitytesting for all weak links is very important It ensures that the broachingmachine operates stably during work without any problems.

When the machine works, external forces will appear acting on theweak links At that time, internal forces will appear inside the weak links.From there we will get the generated stress corresponding to the internalforce

Figure 2.4 Internal forces in detail

To know whether the weak links are enough to meet the durabilityconditions or not, we need to calculate the stress generated when we know theexternal force acting on it Then, we need to compare with the allowable stress.Depending on the material, weak links will have different allowable stresses If thegenerated stress is less than the allowable stress, then the weak links meet thedurability condition

For broaching machines, when the broaching machine performs thebroaching operation, the working xylan mainly moves horizontally or vertically, sothe weak links on the machine will mainly be deformed in two directions, that is,tensile and compression withstand bending

2.2 Problem of material strength of bars subjected tension/compression:

When a bar of material is affected by an external force, it causes thebar is pulled or compressed, the formula to calculate the stress producedis:[12]

σ =NA (6)