Wuhan University of Technology Graduation Design (Thesis)

Design of e-Palette mobile platform front suspension system

College (Department): International Education College

Professional class: Class 1601 for vehicle major

Student name: Wang Peiliao

Adviser: Han Aiguo

Dissertation Originality Statement

I solemnly declare that the papers submitted are the research results of my independent research under the guidance of my supervisor. Except for the content specifically quoted in the text, this paper does not include any other individual or collective work that has been published or written. I am fully aware that the legal consequences of this statement are my responsibility.

Author's signature:

year month day

Dissertation copyright use authorization

The author of this dissertation fully understands the school's regulations on the protection and use of the dissertation, agrees that the school reserves and submits a copy and electronic version of the dissertation to the relevant dissertations. management department or institution, allowing the dissertation to be consulted and borrowed. I authorize the provincial excellent bachelor thesis selection institution to compile all or part of the content of the dissertation into the relevant data for retrieval, and can use copying, reduction or scanning and other copying methods to save and compile the dissertation.

This dissertation belongs to 1. confidentiality, and this power of attorney applies after decryption in

2. Unclassified.

(Please tick "√" in the corresponding box above)

(No.4 Song Dynasty)

Author's signature: year month day

Tutor's signature: year month day

Abstract

Suspension is an important part of an automobile and plays a vital role in the stability and comfort of the vehicle. Therefore, analyzing and designing the suspension is of great significance for a deeper understanding of the performance of the automobile. In this dissertation, the e-palette is taken as the research object to design and calculate its front suspension.

At the beginning of the design, I consulted and studied a lot of literature and design manuals, learned different suspension types and main components of the suspension, and determined the type of this suspension, that is, the double-wishbone independent suspension was used as the front suspension of this model.

When designing, first analyze the impact of suspension on vehicle smoothness and operability, and then come up with effective measures for improvement. Then, through the suspension parameters, the static deflection, dynamic deflection and suspension stiffness of the suspension are calculated. Then the suspension guide mechanism, coil spring and shock absorber were designed and checked in sequence, the parameters of the main components of the suspension were determined, and the design was completed.

The ideas and procedures of this suspension design are highly representative and can be used for readers to learn from.

Keywords: suspension; e-palette; double wishbone; shock absorber

Table of Contents

Chapter 1 Introduction 1

1.1 The research object and significance of the subject 1

1.2 The main research tasks of the subject 2

Chapter 2 Suspension Overview 4

2.1 The function and composition of the suspension 4

2.2 Selection of car suspension 5

2.3 Double wishbone suspension 7

2.4 Main characteristics of suspension 9

2.4.1 Vertical elastic characteristics of suspension 9

2.4.2 Characteristics of shock absorber 11

Chapter 3 Determination of main parameters of suspension 12

3.1 Determine the main parameters of the reference model 12

3.2 Static deflection and dynamic deflection of suspension 12

3.3 Stiffness calculation of suspension 13

Chapter 4 The Design of the Double Wishbone Independent Suspension Guide Mechanism 15

4.1 Design requirements for guiding mechanism 15

4.2 Arrangement parameters of the guide mechanism 15

4.2.1 Roll center 15

4.2.2 Roll axis 16

4.2.3 Trim center 16

4.2.4 Positioning angle of suspension cross arm 16

4.2.5 The layout plan of the upper and lower cross arms in the longitudinal plane 17

4.2.6 The layout plan of the upper and lower cross arms in the horizontal plane 19

4.2.7 Arrangement scheme of the swing axis of the upper and lower cross arms in the horizontal plane 19

4.2.8 Determination of the length of the upper and lower cross arms 21

Chapter 5 Simulation analysis based on Adams / car 24

5.1 Introduction of Adams / car software 24

5.2 Simulation analysis of Adams / car 24

5.3 Optimization of suspension parameters based on Adams / car 27

Chapter 6 Design calculation of coil spring 31

6.1 Types of coil springs 31

6.2 Basic parameters of coil spring 31

6.3 Calculation of spring geometric parameters 32

6.4 Spring check 35

6.4.1 Spring stiffness check calculation 35

6.4.2 Checking the shear stress on the spring surface 35

Chapter 7 Design of shock absorber 36

7.1 Classification of shock absorbers 36

7.2 Design calculation of basic parameters of shock absorber 38

7.2.1 Determination of relative damping coefficient ψ 40

7.2.2 Determination of damping coefficient of shock absorber 40

7.2.3 Determination of the maximum unloading force F0 41

7.2.4 Selection of main dimensions of shock absorber 42

7.3 Design calculation of damper valve system parameters 44