An “Engineering Research Series” title. Valve wear and its effect upon engine performance still presents a major challenge to the tribologist. Although new valve materials and production techniques are constantly being developed, these advances have been outpaced by demands for increased engine performance. The drive for reduced oil consumption and exhaust emissions, use of lead-replacement and low-sulphur fuels, and the introduction of alternative fuels such as gas all have implications for valve and seat insert wear.
Automotive Engine Valve Recession aims to provide the reader with a complete understanding of valve recession. The fundamental nature of contact and wear between valves and valve seats is considered, followed by an outline of the essential features of valve operation and the potentially serious problems associated with wear and valve recession in automobile engines. An overview is then given of an experimental study of valve wear and the development of special apparatus for the simulation of engine operating conditions carried out in the School of Mechanical Engineering, University of Sheffield, UK.
CONTENTS INCLUDE:
- Introduction
- Valve operation and design
- Valve failure
- Analysis of failed components
- Valve and seat wear testing apparatus
- Experimental studies on valve wear
- Design tools for prediction of valve recessionВ and solving valve failure problems.
Author(s): Roger Lewis
Series: Engineering Research Series (REP)
Publisher: Wiley
Year: 2002
Language: English
Commentary: 27459
Pages: 156
Tags: Транспорт;Двигатели внутреннего сгорания (ДВС);Конструирование ДВС;
Contents......Page 8
Series Editor’s Foreword......Page 12
Authors’ Preface......Page 14
Notation......Page 16
1.2 Valve failure concerns......Page 18
1.3 Layout of the book......Page 20
1.4 References......Page 22
2.1.1 Function......Page 24
2.1.2 Operating systems......Page 25
2.1.3 Dynamics......Page 26
2.1.4 Operating stresses......Page 29
2.1.5 Temperatures......Page 30
2.2.1 Poppet valve design......Page 32
2.2.2 Materials......Page 34
2.3 References......Page 36
3.2 Valve recession......Page 38
3.2.1 Causes of valve recession......Page 39
3.2.2 Wear characterization......Page 43
3.2.3 Reduction of recession......Page 45
3.4 Torching......Page 46
3.5.1 Temperature......Page 48
3.5.4 Rotation......Page 51
3.7 References......Page 53
4.2.1 Specimen details......Page 56
4.2.2 Profile traces......Page 57
4.2.3 Visual rating......Page 59
4.3.1 Valve evaluation......Page 62
4.3.2 Discussion......Page 63
4.4 Failure of seat inserts in a 1.8 litre, DI, diesel engine......Page 64
4.4.1 Inlet seat insert wear......Page 65
4.4.2 Deposits......Page 67
4.4.4 Inlet valve wear......Page 68
4.5 Conclusions......Page 69
4.6 References......Page 70
5.2 Requirements......Page 72
5.4 Extant valve and seat wear test rigs......Page 73
5.5 University of Sheffield valve seat test apparatus......Page 76
5.5.1 Hydraulic loading apparatus......Page 77
5.5.2 Motorized cylinder head......Page 84
5.5.3 Evaluation of dynamics and loading......Page 86
5.6 References......Page 96
6.2.1 Experimental details......Page 98
6.2.2 Results......Page 101
6.3 Seat insert materials......Page 120
6.3.1 Experimental details......Page 121
6.3.2 Results......Page 123
6.5 References......Page 128
7.2.1 Review of extant valve wear models......Page 130
7.2.2 Development of the model......Page 132
7.2.3 Implementation of the model......Page 141
7.2.4 Model validation......Page 144
7.4 Solving valve/seat failure problems......Page 149
7.5 References......Page 153
S......Page 154
W......Page 155
