(Đồ án hcmute) building practice exercises based on models of steering system

MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT AUTOMOTIVE ENGINEERING BUILDING PRACTICE EXERCISES BASED ON MODELS OF STEERING SYSTEM ADVISOR: ME DUONG NGUYEN LAC HAN STUDENT: LY HOANG KHANH NGUYEN PHU THIEN SKL Ho Chi Minh City, December, 2022 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT BUILDING PRACTICE EXERCISES BASED ON MODELS OF STEERING SYSTEM Student: LY HOANG KHANH Student ID: 18145027 Student: NGUYEN PHU THIEN Student ID: 18145060 Major: AUTOMOTIVE ENGINEERING Advisor: DUONG NGUYEN HAC LAN, ME Ho Chi Minh City, December 2022 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT BUILDING PRACTICE EXERCISES BASED ON MODELS OF STEERING SYSTEM Student: LY HOANG KHANH Student ID: 18145027 Student: NGUYEN PHU THIEN Student ID: 18145060 Major: AUTOMOTIVE ENGINEERING Advisor: DUONG NGUYEN HAC LAN, ME Ho Chi Minh City, December 2022 THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December, 2022 GRADUATION PROJECT ASSIGNMENT Student name: LY HOANG KHANH Student ID: 18145027 Student name: NGUYEN PHU THIEN Student ID: 18145060 Major: Automotive Engineering Class: 18145CLA Advisor: DUONG NGUYEN HAC LAN, ME Phone number: 0903128567 Date of assignment: 30/9/2022 Date of submission: 18/12/2022 Project title: Building practice exercises based on models of steering system Initial materials provided by the advisor: ● Wheel alignment, (Toyota) Content of the project: • Theoretical overview of electric power steering system • Theoretical overview of hydraulic power steering system • Learn about subject output standards and Bloom taxonomy • Building exercises about models Final product: Thesis report including the calculation, simulation, and experimental results CHAIR OF THE PROGRAM ADVISOR (Sign with full name) (Sign with full name) THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness -Ho Chi Minh City, December, 2022 ADVISOR’S EVALUATION SHEET Student name: LY HOANG KHANH Student ID: 18145027 Student name: NGUYEN PHU THIEN Student ID: 18145060 Major: Automotive Engineering Project title: Building practice exercises based on models of steering system Advisor: DUONG NGUYEN HAC LAN, ME EVALUATION Content and workload of the project Strengths: Weaknesses: Approval for oral defense? (Approved or denied) Overall evaluation: (Excellent, Good, Fair, Poor) Mark…………… (in words: ) Ho Chi Minh City, December, 2022 ADVISOR (Sign with full name) THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December, 2022 PRE-DEFENSE EVALUATION SHEET Student name: LY HOANG KHANH Student ID: 18145027 Student name: NGUYEN PHU THIEN Student ID: 18145060 Major: Automotive Engineering Project title: Building practice exercises based on models of steering system Name of Reviewer: EVALUATION Content and workload of the project Strengths: Weaknesses: Approval for oral defense? (Approved or denied) Overall evaluation: (Excellent, Good, Fair, Poor) Mark…………… (in words: ) Ho Chi Minh City, Demcember, 2022 REVIEWER (Sign with full name) THE SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom– Happiness Ho Chi Minh City, December, 2022 EVALUATION SHEET OF DEFENSE COMMITTEE MEMBER Student name: LY HOANG KHANH Student ID: 18145027 Student name: NGUYEN PHU THIEN Student ID: 18145060 Major: Automotive Engineering Project title: Building practice exercises based on models of steering system Name of Defense Committee Member: EVALUATION Content and workload of the project Strengths: Weaknesses: Overall evaluation: (Excellent, Good, Fair, Poor) Mark…………… (in words: ) Ho Chi Minh City, December, 2022 COMMITTEE MEMBER (Sign with full name) DISCLAIMER We hereby state that the thesis was written at the Ho Chi Minh City University of Technology and Education under the supervision of Duong Nguyen Hac Lan, ME This is our original study The content in the research paper is all quoted from reliable sources, and we carry out this thesis ourselves based on the models available at the chassis workshop We guarantee that this topic has not been done before by anyone vii ACKNOWLEDMENTS During the project implementation period, it is not too short and not too long, but it has helped us gain a lot of interesting and lively knowledge, which helps to increase our ability to work in groups and find research materials Until today, completing the graduation project on time and with good results based on the efforts of the implementers, as well as the instructors have helped a lot We are very grateful to Mr Duong Nguyen Hac Lan, lecturer of the Automotive Chassis Department of the Faculty of Dynamic Engineering, University of Technology and Education of Ho Chi Minh City, he has enthusiastically taught and guided us a lot in researching and building a lesson The complete project, with the enthusiasm of the teacher, provided us with a lot of useful materials related to the topic, and adjusted, and supported the topic in a thoughtful way We are very grateful for the dedication of the teacher In addition, teachers at the school and friends around have encouraged and created conditions for us to complete the project quickly and smoothly, we will remember this gratitude and be good memories of our time with our students Sincere thanks to the teachers and friends who helped us In the process of implementing this project, although we have tried our best, there will be inevitably shortcomings We hope to receive the comments and criticism of lecturers and students Once again, thank you, lecturers and family and friends around us Ho Chi Minh City, December 2022 Student group Ly Hoang Khanh and Nguyen Phu Thien viii TABLE OF CONTENTS DISCLAIMER vii ACKNOWLEDMENTS viii TABLE OF CONTENTS ix LIST OF FIGURES xi LIST OF TABLES xiv ABSTRACT xv Chapter 1: INTRODUCTION 1.1 Purpose of thesis selection 1.2 Target of the research 1.3 Objects of research 1.4 The method of the research 1.5 Knowledge of the research 1.6 Structure of thesis Chapter 2: LITERATURE REVIEW 2.1 Overview about steering system 2.1.1 The history about steering system 2.1.2 Requirements and classification of steering systems 2.1.2.1 Requirement 2.1.2.2 Types of steering system 2.1.3 2.2 The structure of steering system 2.1.3.1 Steering wheel and steering column 10 2.1.3.2 Steering linkage 13 2.1.3.3 Steering mechanism 14 2.1.3.4 Power steering 16 Electric power steering 16 2.2.1 System layout type 17 2.2.2 Structure of the electric power steering system 19 2.2.2.1 Torque sensor 19 2.2.2.2 Power steering motor 24 2.2.2.3 EPS ECU central control unit 25 2.2.3 Working principle 26 ix 11 Basic steps to change the power steering fluid Why you need to change the power steering fluid? G2.1 3&4 12 If on the model, we steer to the left or right, the oil pressure is below 65kg/cm2, what is the reason G1.1 13 When the power steering oil in the reservoir is low So what are the symptoms that the car encounters? G2.1 G4.1 G2.1 14 15 Why small cars (under seats) often use electric power steering, while large trucks use hydraulic power steering? 3.6.2 The reference answers for the above exercises - Toyota Vios Electronic power steering system model ● Exercise Present the concept, requirements of electric power steering system? Answer: a) Defination: Electronic power steering has the effect of reducing the driver's steering wheel rotation force, reducing fatigue when driving long distances Especially when the vehicle is running at high speed, power steering is also intended to improve the safety of movement when the vehicle has a wheel problem such as a tire explosion, out of compressed air in the tire and reduce the impact transmitted from the wheel to the steering wheel 85 To improve ride comfort, most modern cars use wide, low-pressure tires to increase the contact area with the road surface As a result, a greater driving force is required Steering force can be reduced by increasing the gear ratio of the steering mechanism However, it requires more steering wheel turning as the vehicle turns, which makes sharp turns impossible So, in order to keep the steering responsive while still requiring little steering force, it is necessary to so with power steering b) Basic requirements for power steering: + Ensure flexibility Power steering must have a control force on the steering wheel rim that is small enough to reduce the weight when turning the steering wheel, but also enough to cause a sense of control for the driver + When the power steering system fails, the steering system can still be controlled like a normal mechanical steering system + The structure of the power steering system must be simple, easy to take care of, maintain and repair + Ability to manually rotate the steering wheel to the original position ● Exercise Compare electric power steering system and hydraulic power steering system? Answer: + With HPS (Hydraulic Power Steering) system, the power supply is completely separate from the steering system, HPS needs a power source (hydraulic pump, hydraulic cylinders, valves, oil lines) Designing HPS is a considerable amount of work, partly due to the considerable amount of equipment required by the system, which means that HPS is not easily installed in compact vehicles + With such a control system HPS requires high precision in manufacturing, when there is a problem with the power steering system, the driver's force must be greater than the driving force due to the resistance of the fluid in the power steering system The use of power steering oil is also a drawback of it When replacing and repairing, the amount of oil released affects the environment + The EPS power steering system is created from a DC electric motor mounted on the steering system The system consists of only two parts: a drive shaft with a DC motor and an EPS ECU, so the system is relatively compact, easy to install, the main mass is electric motor, high efficiency and special operation Only consumes energy when required by the steering system With its compactness, clean energy is used, and no energy is wasted compared to the oil power steering system If the pump HPS system will still work even when the system does not require power, the EPS system can offer the possibility of improvements to save fuel for the car 86 ● Exercise Present the general working principle of electric power steering system (EPS)? Answer: Based on the operation of EPS, its working principle is divided into the following steps: + Step Power steering will start working when the driver applies force to turn the steering wheel + Step The force applied to the steering wheel rim will cause the torsion bar in the steering gear to twist The torque sensor determines the angle of rotation of the torsion bar and sends the calculated steering force signals to the ECU + Step From the current torque and steering speed sensor, it will be sent to the EPS ECU + Step Based on steering force, movement speed, engine speed, steering angle, steering speed in the ECU The EPS ECU calculates the power required to control the electric motor + Step The motor's power steering will act on the steering mechanism with an appropriate power to help the driver rotate the steering wheel gently ● Exercise 4: Presenting the structure of the torque sensor Answer: Consists of an input shaft (attached to the steering wheel), an output shaft (attached to the connecting part of the steering shaft to the steering mechanism), between the input and output shafts connected by a torsion bar On the input shaft, install a No induction ring with grooves to be installed with the teeth of No induction ring And the No induction ring also has teeth and grooves installed on the output shaft Outside the induction loops are coils divided into two coils: detection coil and correction coil ● Exercise 5: State the difference between C-EPS and D-EPS settings Answer: + C-EPS: The power steering unit is located in the driver's cabin, suitable for cars with a small engine compartment, the power steering motor is located on the steering shaft + D-EPS: Power steering is located inside the engine compartment, power steering motor is located right in the steering mechanism, often used on mid-sized cars ● Exercise 6: When turning the steering wheel, it feels heavy, what are the reasons? Answer: 87 + Damaged torque sensor (cannot measure the force and direction of rotation of the steering wheel, so the signal cannot be sent to the EPS ECU) + Power assist motor is damaged (powered but not working) + EPS ECU is damaged + The battery power supply unit has a problem ● Exercise 7: State the position and function of the electric motor Answer: + Location: located right on the steering shaft + Function: receive signals sent back from the ECU, thereby assisting the driver to turn the steering wheel lighter ● Exercise 8: From the parameters displayed on Techstream, why when turning the steering wheel to the right, the Torque Sensor Output value is greater than 2.5A and vice versa? Answer: Because when turning the steering wheel to the right, the torsion bar in the steering mechanism will rotate and the position change between the emitter and the emitter 3, in the intermediate position the voltage will be 2.5A, the gap will be large, The more magnetic flux will pass, then the voltage will be greater than 2.5A and vice versa when turning the steering wheel to the left, the gap will be small and the voltage will then be less than 2.5A ● Exercise 9: Difference between Steering angle sensor and Torque sensor Answer: + About the layout: the steering angle sensor is located near the steering wheel rim Torque sensor is partly on the torsion bar, partly on the output shaft (pinion shaft) In principle, the torque sensor must be arranged on two axes to be able to measure the torque + The steering angle sensor indicates whether the steering wheel is hit more or less The torque sensor, in addition to sensing the steering on the steering wheel, also detects the reaction from the road surface acting back on the steering system ● Exercise 10: Which is correct about electronic power steering? A At low speed, the steering force is higher than normal speed B At low speed, steering force is lower than normal speed C At high speed, the steering force is higher than normal speed D.At high speed, the steering force is lower than normal speed Answer: 88 B and C, when there is electronic power steering, in order to provide safety when operating the vehicle at high speed, the steering force must be heavier than the normal speed to avoid the driver's carelessness Touching the steering wheel causes the steering wheel to rotate and the vehicle to reverse direction At low speeds, the steering force needs to be light to create a comfortable driving feeling for the driver ● Exercise 11: Which signal is not an input signal in the electronic power steering system? A Torque sensor B Vehicle speed C Steering angle D Tyre pressure Answer: D the input signal of the electric power steering system includes signals: torque sensor, vehicle speed, steering angle ● Exercise 12 Fill in the components of an electric power steering system Answer: 89 ● Exercise 13: Based on the voltage and torque graph No and 3, analyze the cause of the voltage difference and why sometimes the difference is large and sometimes the difference is small Answer: + Voltage appears on the graph based on the angle of rotation of the steering wheel, causing the rod to twist, changing the position between the gaps of emitter and emitter Therefore, there is a voltage difference between the two values above + The large and small difference value depends on the torsion angle and torsion force of the rod, if the steering force is small, the rod will twist less and the voltage difference between the two torque sensor values is small, vice versa if the steering wheel is rotated With a large force, the torsion bar is large and a large voltage difference occurs between these two values ● Exercise 14: Fill in the blanks in the correct order 90 Answer: - Some exercises on hydraulic power steering system ● Exercise 1: State the possible causes when the steering wheel returns slowly Answer: + The pressure and the amount of oil injected are uneven, making the steering wheel move slowly, so the steering also becomes quite heavy + Besides, the cause may also be that the segment of the rackhousing is open, causing oil to spill or enter the adjacent compartment In addition, the tie-rod is dry and the lubrication is poor, which also makes the return of the steering wheel delayed ● Exercise 2: The vane pump (power steering pump) makes a noise when turning the steering wheel, what is the cause? Answer: + It is possible that the rubber seals in the pump casing or when installed are not careful to let the air into the pump causing noise + Install the impellers backward, there are a total of 10 impellers in the pump, including sides: inside and outside The inner surface has grooves, the oval outer surface is smoothed for friction with the outer cavity When the engine rotates at 1000-2000 rpm, if 91 installed upside down, the groove on the inside will friction with the outer cavity causing a very loud noise when turning the steering wheel + The most common error is using the wrong genuine oil ● Exercise 3: Why when starting the engine, the rpm will jump to about 1000 rpm and then back to 700-800 rpm? Answer: Because when starting the car The power steering pump will use part of the engine's power to rotate the pulley to help the pump work, so then we will see the rpm on the dashboard will inch up to about 1000 rpm and then back to 700-800 rpm ● Exercise 4: Driving to the left is heavier than when hitting to the right What is the cause? Answer: + Due to low left tire pressure (Bread tank or deflated) + The left oil seal is leaking + Control valve misplaced ● Exercise 5: Students should follow the steps below to test the hydraulic power steering model before operation a) Check belt tension b) Check the oil level c) Check oil pressure ● Exercise 6: Fill in the appropriate phrases for each part 92 Answer: ● Exercise 7: When and how will the safety valve work? Answer: The safety valve works when the driver steers all the way to the left or right and holds or the guide wheel is obstructed Operation: The oil pressure goes down to P1 much leading to the steering mechanism, at this time the pressure on the P2 side will be large, pushing the flow control valve to the right side, at this time the safety valve works to let the oil line run back pump suction side, reducing the pressure at P2 ● Exercise 8: Summarize the steps of the general operating principle of the hydraulic power steering system? Answer: + Step 1: The crankshaft pulley rotates the power steering pump + Step 2: Power steering pump sucks oil from reservoir to distribution valve + Step 3: The control valve will decide which cavity the oil enters in the cylinder based on the direction of the steering wheel ● Exercise 9: After connecting the power to the model, turn the control knob to "OPEN" and "CLOSE" mode, observe and point out the difference between the two modes The reason for that difference? Answer: + Turn the knob to "CLOSE", the pressure displayed is about 75-80 kg/cm2 Turn the knob to "OPEN', the pressure displayed is about 20-25kg/cm2 + The reasons for the difference are: When turning the knob to “CLOSE” mode, the oil line from the power steering pump to the rotary valve will be locked Continuously pumped oil causes the pressure of chamber P1 to increase, but not the steering mechanism, leading to the pressure of chamber P2 exceeding the specified level, at this time the safety valve will work to reduce the pressure When the pressure P2 decreases, the control valve pushes to the left and controls the maximum pressure 93 ● Exercise 10: After connecting the power to the model, try to turn the steering wheel all the way to the left or right and hold for to seconds, then the following requirements: a) Observe the change in readings on the pressure gauge and interpret b) If turn the steering wheel all the way to one side and then hold it for 10 to 15 seconds, will there be any harm? Why? c) After answering the above two points, give some advice to the driver to reduce damage to the steering system Answer: a) When turning the steering wheel left or right and holding for 3-4 seconds: The meter shows a pressure of about 75-80 kg/cm2, then the system works normally b) If you turn the steering wheel all the way to one side and hold it for 10 to 15 seconds, it will damage the system, because: + Then the oil will be pumped more and more, the system will work continuously The power steering pump may have worn the vane, safety valve may have damaged the spring c) Advice for drivers: + Do not turn the steering wheel while the car is parked + When you turn the steering wheel all the way, you should release it slightly so that the steering wheel can turn back a bit + Avoid turning the wheel all the way to one side for too long ● Exercise 11: Basic steps to change the power steering fluid Why you need to change the power steering fluid? Answer: 94 + We proceed to remove the return line from the tank and drain the oil into the tray + Start the car and turn the steering wheel all the way to the right and left to drain the oil into the tray and then turn off the engine + Proceed to pour new oil into the tank and then start the engine for the old oil to drain out of the tray, then turn off the engine Repeat 2-3 times until the air bubbles in the oil are gone + Insert the return oil pipe into the reservoir + Start the engine and steer to the sides 3-4 times to drain the air out of the system, check the tank that there is no air in the oil + Change the power steering oil to ensure smooth operation of the system, avoid damage to the power steering pump due to dirt in the oil ● Exercise 12: If on the model, we steer to the left or right, the oil pressure is below 65kg/cm2, what is the reason Answer: + Stretched belt: When the belt is stretched, the pulley will rotate smoothly for the booster pump, causing insufficient power to rotate the booster pump, causing the pressure to decrease + Leaking seal: Leaking seal causes oil to leak out, reducing the pressure from the pump to the steering mechanism + Power steering pump impeller worn out: leading to insufficient pump pressure into the steering mechanism + Rotary valve: It is possible that the grooves between the chambers are worn, causing oil to leak from one compartment to another, causing oil to return to the reservoir ● Exercise 13: When the power steering oil in the reservoir is low So, what are the symptoms that the car encounters? Answer: + Heavy steering and slow return: The steering wheel moves slowly due to reduced pressure and low oil flow + Power steering pump makes noise due to insufficient amount of pumped oil causing friction between pump components + There is noise coming from the steering system: If the power steering makes a noise, especially when you are moving slowly + Steering wheel jerks or suddenly vibrates: Sometimes the steering wheel will jerk when you try to turn it from one direction to another 95 • Exercise 15: Why small cars (under seats) often use electric power steering, while large trucks use hydraulic power steering? Answer: + Small cars rarely need large capacity to assist, because in order to increase capacity, it is necessary to increase the current through the formula P=UxI The voltage U is only about 12V, so if you increase the amperage, it will generate a lot of heat, reducing the life of the system + Large vehicles use hydraulic power steering because the power steering pump is linked to the engine through a belt, so when the vehicle is running at high speed, the hydraulic steering system will be lighter and more durable than electric power steering The downside if hitting the steering wheel lightly when the car is at high speed also makes the car easy to lose control 96 Chapter 4: CONCLUSION AND RECOMMENDATION 4.1 Conclusion - After a period of implementing this project, although there were many difficulties in implementing the project, we still tried to meet the requirements of the teacher In addition, we also + Understand the theory of electric power steering and hydraulic power steering models available in the workshop + Use models to test and diagnose + Learn a lot about diagnostic software, Bloom Scale + Know how to build and solve problems encountered on the model - Our team completed on schedule and fully met the standards after a period of research and enthusiastic help from Mr Duong Nguyen Hac Lan 4.2 Recommendation After the implementation of the thesis, we have some ideas and suggestions to help the interaction between lecturers and students become more effective in the future: - Perform correction of zero-point value of torque sensor in Toyota Vios electric power steering system model - Besides in the chassis workshop, there are many new and teaching models such as Hyundai air suspension models, ABS brake models, automatic transmission models We hope that the following groups will have a continued understanding of the theory and give a lot of exercises on the above models - Developing advanced exercises and provide application software to make lectures lively 97 REFERENCE [1] History of the steering system: https://otobabo.vn/lich-su-hinh-thanh-he-thong-tro-luclai-tren-o-to/ [2] https://dangkiem5006v.com.vn/tim-hieu-ve-cac-loai-he-thong-lai-pho-bien-hien-nay/ [3] Steering System (Toyota) [4] https://news.oto-hui.com/nhung-kieu-dat-dong-co-dien-trong-he-thong-lai-tro-lucdien-eps/ [5] Torque sensor : https://www.youtube.com/watch?v=vPJhfM3GmjM [6] Type of torque sensor: http://oto.saodo.edu.vn/nghien-cuu-khoa-hoc/cam-bienmomen-xoan-tren-he-thong-lai-tro-luc-dien-tu-479.html [7] Instructions for reading electrical circuit diagrams: https://suachuaoto.edu.vn/huong-dan-doc-so-do-mach-dien-he-thong-lai-tro-luc-dientren-toyota-yaris/ [8] Operation of flow control valve: https://oto-hui.com/threads/chuc-nang-va-nguyen-lyvan-dieu-khien-luu-luong-trong-bom-tro-luc-lai.42996/ [9] Using the bloom taxonomy to give exercises: https://cft.vanderbilt.edu/guides-subpages/blooms-taxonomy/ [10] Setup Techstream: https://oto-hui.com/threads/huong-dan-cai-techstream-tren-win10-64-bit-va-driver-mini-vci-de-giao-tiep.101676/ [11] Steering mechanism: https://www.mcx5.org/steering_column_and_shaft-1754.html [12] Working principle of power steering pump: https://youtu.be/78RtDC0hvOc [13] Rotary valve operation: https://youtu.be/noKgvdxCR0s [14] Diagnosing electric power steering system fault hui.com/threads/ma-loi-va-cach-thao-he-thong-tro-luc-lai.48938/ codes: https://oto- 98 S K L 0