福州大学：《液压与气压传动》课程电子教案（PPT教学课件）Chapter 08 Examples of Hydraulic Systems

Chapter 8 Examples of Hydraulic Systems Take steps: 1.Find out the working principle for a given set of machine or apparatus and understand the performance of the desired function for speeds and pressures and directions during the machine working periods; 2.Read the preliminary sketch of the hydraulic system,classified into several basic hydraulic circuit units by actuators; 3.Analyze respectively the principles of several basic circuits and find out the relationship between basic circuits to tidy up the lines; 4. Safety ofoperation; 5. Efficiency of operation, 6. Sum up and comprehend the features of the hydraulic system based on the functions of several basic hydraulic circuits mentioned above Homepage List Upwards Downwards Retum Exit

Chapter 8 Examples of Hydraulic Systems 1 1. Find out the working principle for a given set of machine or apparatus and understand the performance of the desired function for speeds and pressures and directions during the machine working periods; 2. Read the preliminary sketch of the hydraulic system ,classified into several basic hydraulic circuit units by actuators; 3. Analyze respectively the principles of several basic circuits and find out the relationship between basic circuits to tidy up the lines; 4. Safety of operation; 5. Efficiency of operation; 6. Sum up and comprehend the features of the hydraulic system based on the functions of several basic hydraulic circuits mentioned above. Take steps:

Chapter 8 Examples of Hydraulic Systems Table of contents(4 Examples) 8.1 Hydraulic System of Power-slipway of Combined Machines Tools 8.2 Hydraulic System of Plastic Injection Moulding Machine 8.3 Hydraulic System of YA32-200 Type Four-column Universal Press Machine 8.4 Hydraulic System of Manipulators 2 Homepage List Upwards Downwards Retumn Exit

Chapter 8 Examples of Hydraulic Systems 2 Table of contents (4 Examples) 8.1 Hydraulic System of Power-slipway of Combined Machines Tools 8.2 Hydraulic System of Plastic Injection Moulding Machine 8.3 Hydraulic System of YA32-200 Type Four-column Universal Press Machine 8.4 Hydraulic System of Manipulators

Chapter 8 Examples of Hydraulic Systems 8.1 Hydraulic System of Power-slipway for combined Machine Tools 8.1.1 Introduction 8.1.2 The principle of hydraulic system for YT4543 type power-slipway 8.2.3 Characteristics 3 Homepage List Upwards Downwards Retun Exit

Chapter 8 Examples of Hydraulic Systems 3 8.1 Hydraulic System of Power-slipway for combined Machine Tools 8.1.1 Introduction 8.1.2 The principle of hydraulic system for YT4543 type power-slipway 8.2.3 Characteristics

Chapter 8 Examples of Hydraulic Systems 8.1 Hydraulic System of Power-slipway for combined Machine Tools 8.1.1 Introduction 8.1.2 The principle of hydraulic system for YT4543 type power-slipway The principle chart and operation cycle table of hydraulic system for YT4543 type power-slipway are shown in Fig.8-1 and Tab.8-1, respectively.This system can accomplish a semi-automation cycle,i.e., quick feed→working feed→end block dwell→quick retract stop 4 Homepage List Upwards Downwards Retun Exit

Chapter 8 Examples of Hydraulic Systems 4 8.1.1 Introduction 8.1.2 The principle of hydraulic system for YT4543 type power-slipway The principle chart and operation cycle table of hydraulic system for YT4543 type power-slipway are shown in Fig.8-1 and Tab.8-1, respectively. This system can accomplish a semi-automation cycle, i.e., quick feed→ working feed → end block dwell →quick retract →stop 8.1 Hydraulic System of Power-slipway for combined Machine Tools

Chapter 8 Examples of Hydraulic Systems 1-Hydraulic pump 中 2,7,12-Checkvalve 3-Directional controlvalve w by hydraulic actuated 3YALZw io 4-Pilot solenoid valve 图1图” 5-Against pressure valve 6-Sequence valve 8,9-Speed adjusting valve 10-Solenoid valve W阳w 11-Pressure switch 13-Distance valve 14-Hydraulic cylinder a-Quick feed b-Working feed 1 c-Working feed 2 d-Retraction and stop Fig.8-1 YT4543 type power-slipway hydraulic system 5 Homepage List Upward达s Downwards Retumn Exit

Chapter 8 Examples of Hydraulic Systems 5 Fig.8-1 YT4543 type power-slipway hydraulic system 1- Hydraulic pump 2, 7,12-Check valve 3- Directional control valve by hydraulic actuated 4- Pilot solenoid valve 5- Against pressure valve 6- Sequence valve 8, 9- Speed adjusting valve 10- Solenoid valve 11- Pressure switch 13- Distance valve 14- Hydraulic cylinder a-Quick feed b-Working feed 1 c-Working feed 2 d-Retraction and stop

Chapter 8 Examples of Hydraulic Systems 1.Quick feed 2.Working feed 1 3.Working feed 2 4,End block dwell 5.Quick retract 6.Stop at the start position Homepage List Upwards Downwards Retun Exit

Chapter 8 Examples of Hydraulic Systems 6 1.Quick feed 2. Working feed 1 3. Working feed 2 4. End block dwell 5. Quick retract 6. Stop at the start position

Chapter 8 Examples of Hydraulic Systems Tab.8-1 YT4543 type power-slipway hydraulic system operation eycle Component IYA 2YA 3YA Pressure Distance Operation switch 11 valve 13 Quick feed Actuated (differential-area connection) Working feed 1 + Released Working feed 2 + + Released End block dwell + + Released Quick retract 十 Released →Actuated Stop Actuated Homepage List Upwards Downwards Retumn Exit

Chapter 8 Examples of Hydraulic Systems 7 Component Operation 1YA 2YA 3YA Pressure switch 11 Distance valve 13 Quick feed (differential-area connection) + - - - Actuated Working feed 1 + - - - Released Working feed 2 + - + - Released End block dwell + - + + Released Quick retract - + ± - Released →Actuated Stop - - - - Actuated Tab.8-1 YT4543 type power-slipway hydraulic system operation cycle

Chapter 8 Examples of Hydraulic Systems 8.1.3 Characteristics (1)A volume throttling speed control circuit is composed by a pressure-limiting variable vane pump and a speed adjusting valve. (2)A pressure-limiting variable pump and differential-area connection method are used in this system to accomplish quick feed. (3)Using distance valves and sequence valves for quick- working feeds shift 8 Homepage List Upward止s Downwards Retumn Exit

Chapter 8 Examples of Hydraulic Systems 8 8.1.3 Characteristics (1) A volume throttling speed control circuit is composed by a pressure-limiting variable vane pump and a speed adjusting valve. (2) A pressure-limiting variable pump and differential-area connection method are used in this system to accomplish quick feed. (3) Using distance valves and sequence valves for quick￾working feeds shift

Chapter 8 Examples of Hydraulic Systems 8.2 Hydraulic System of Plastic Injection Moulding Machines 8.2.1 Introduction 8.2.2 Operating principle of hydraulic system of SZ- 250A type plastic injection moulding machine 8.2.3 Characteristics Homepage List Upwards Downwards Retun Exit

Chapter 8 Examples of Hydraulic Systems 9 8.2 Hydraulic System of Plastic Injection Moulding Machines 8.2.1 Introduction 8.2.2 Operating principle of hydraulic system of SZ- 250A type plastic injection moulding machine 8.2.3 Characteristics

Chapter 8 Examples of Hydraulic Systems 8.2 Hydraulic System of Plastic Injection Moulding Machines 8.2.1 Introduction The injection moulding processing is shown below: Closing mode chamber-injection seat moving onwards 一→injecting→holding pressure一 cooling ,→injection preplastic seat going back-opening mode chamber-pushing out the product->put cylinder going back ->Closing mode chamber again. 10 Homepage List Upward止s Downwards Retun Exit

Chapter 8 Examples of Hydraulic Systems 10 8.2.1 Introduction The injection moulding processing is shown below: Closing mode chamber → injection seat moving onwards → injecting → holding pressure → →injection seat going back → opening mode chamber → pushing out the product → put cylinder going back →Closing mode chamber again.       preplastic cooling 8.2 Hydraulic System of Plastic Injection Moulding Machines