西北农林科技大学：《汽车拖拉机学》课程PPT教学课件（英文版，上册）Chapter 3 Ventilation system

Chapter 3 Ventilation system Section 1 Valve train The function of valve train in accordance with the work process and the requirements of the order of fire of every engine cylinder,open and close the intake and exhaust valves of each cylinder in time,supply clean,adequate amount of fresh air or combustible mixture on time,and discharge emissions as thoroughly as possible in time,in order to ensure effective combustion process. 机械电子工程学 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system The function of valve train in accordance with the work process and the requirements of the order of fire of every engine cylinder , open and close the intake and exhaust valves of each cylinder in time, supply clean, adequate amount of fresh air or combustible mixture on time, and discharge emissions as thoroughly as possible in time, in order to ensure effective combustion process. Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train 1.The Type of Valve Train Common types of valve train are two kinds of valve and porosity. Overhead valve By valve position Side valve Gear transmission Valve By transmission Chain transmission Toothed belt transmission Two valve By valve number Four valve Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system 1. The Type of Valve Train Common types of valve train are two kinds of valve and porosity.  Valve By valve position  Overhead valve Side valve By transmission  Gear transmission Chain transmission Toothed belt transmission By valve number  Two valve Four valve Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train 10 11 12 1.1 Overhead valve train 13 14 15 Automobile and Tractor Northwest A&F University 电子用

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system 1.1 Overhead valve train Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train 13 1.2 Side valve train 机被与电子工服保 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system 1.2 Side valve train Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train 2.Construction of Valve Train Valve train consists oftwo parts of valve group and valve transmission group 2.1 Valve group valve、.valve seat、.valve guide pipe、valve *Cotter spring Spring seat Valve spring 00 →Valve guide pipe Valve seat Valve 机械电子工程二 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system 2. Construction of Valve Train Valve train consists of two parts of valve group and valve transmission group． Cotter Spring seat Valve spring Valve guide pipe Valve seat Valve 2.1 Valve group valve、valve seat、valve guide pipe、valve spring． Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train (1)Valve (a) (b) (e) Figure 3.4 Valve head construction type Figure 3.5 Valve cone angle (a)flat heads (b)horn heads 机被寿电子工程原二 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system (1) Valve Figure 3.4 Valve head construction type (a) flat heads (b) horn heads Figure 3.5 Valve cone angle Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train (2)Valve seat (3)Valve guide (4)Valve spring a) (b) Figure 3.6 Spring seat fixed form (a)cotter form (b)lockpin form Figure 3.7 Valve guide pipe and valve seat 业机械电子工程学膜 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system (2) Valve seat (3) Valve guide (4) Valve spring Figure 3.6 Spring seat fixed form （a） cotter form （b） lockpin form Figure 3.7 Valve guide pipe and valve seat Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train 2.2 Valve transmission group tappet、push rod、rocker、camshaft、timing gear et al. (1)Tappet ~3 mm -3 mm (a) (b) Figure 3.8 Tappet automatic rotational structure 业机械持电子工程度 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system 2.2 Valve transmission group tappet 、 push rod 、 rocker 、 camshaft 、 timing gear et al. (1) Tappet Figure 3.8 Tappet automatic rotational structure Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train (2)Push rod (3)Rocker 4 5 业电子工程学度 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system (3) Rocker (2) Push rod Section 1 Valve train

Chapter 3 Ventilation system Section 1 Valve train (4)Camshaft Figure 3.10 495-type diesel engine camshaft 机械电子工程学原一 Automobile and Tractor Northwest A&F University

Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system (4) Camshaft Figure 3.10 495-type diesel engine camshaft Section 1 Valve train