液压与气压传动8英文版_

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Chapter 8 Examples of Hydraulic Systems
7. Prevent flowing （2YA＋、7YA＋、9YA＋）
8. Injection seat withdraws （2YA＋、6YA＋）
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Chapter 8 Examples of Hydraulic Systems
cooling → injecting → holding pressure → →injection preplastic
seat going back → opening mode chamber → pushing out
the product → pushing cylinder going back →Closing
(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 quickworking feeds shift.
8.1.1 Introduction 8.1.2 The principle of hydraulic system for
YT4543 type power slip-way
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,
Fig.8-1 YT4543 type power-slipway hydraulic system
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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
mode chamber again.
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Chapter 8 Examples of Hydraulic Systems 8.2.2 Operating principle of hydraulic system of SZ-250A type plastic injection moulding machine Injection moulding machine SZ-250A belongs to a middle and small mould with max. 250 (cm3) capacity of injection. Fig. 8-2 shows the outline of the machine and hydraulic
1YA +
2YA -
3YA -
Pressure switch 11
-
Distance valve 13 Actuated
+
-
-
-
Released
Working feed 2
End block dwell
+
+
-
+
+
+
Released
Released
Quick retract
Stop
7
-
+
-
±
-
-
Released →Actuated Actuated
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Chapter 8 Examples of Hydraulic Systems
Tab.8-1 YT4543 type power-slipway hydrቤተ መጻሕፍቲ ባይዱulic system operation cycle
Component Operation Quick feed (differential-area connection) Working feed 1
Hydraulic and pneumatic pressure transmission
Chapter 8 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.Injection seat moves onwards （2YA＋、7YA＋）
4. Injection
It experiences two stages, i.e., injecting slowly and quickly. (1) Inject slowly（2YA＋、7YA＋、10YA＋、12YA＋）
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.
respectively. This system can accomplish a semi-automation cycle, i.e.,
quick feed→ working feed → end block dwell →quick retract →stop
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Chapter 8 Examples of Hydraulic Systems
Chapter 8 Examples of Hydraulic Systems
Tab. 8-2 Action sequences of solenoid energized for injection moulding machine SZ-250A typed
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Chapter 8 Examples of Hydraulic Systems
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.
9. Open the mould-chamber
(1) Open the mould-chamber slowly （2YA＋or1YA＋、4YA＋）
Pump 1 (or pump 2) is unloaded and the oil from pump 2 (or pump 1) flows into the right chamber of cylinder for closing mould-chamber .
1. Safety gate close
2. Close the mould-chamber
The process of mould-chamber is closed experiences the 4 stages. （1）Closing the mould-chamber slowly (2YA＋、3YA＋).
system for it. The action sequences of solenoid energized is
shown in Tab. 8-2.
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Chapter 8 Examples of Hydraulic Systems
11YA
Fig. 8-2 The outline and hydraulic system of SZ-250A type injection moulding 11
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
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Chapter 8 Examples of Hydraulic Systems
(2) Inject quickly （1YA＋、2YA＋、7YA＋、8YA＋、10YA＋、12YA＋）
5. Holding pressure （2YA＋、7YA＋、10YA＋、14YA＋）
6. Pre-plastic （1YA＋、2YA＋、7YA＋、11YA＋）
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Chapter 8 Examples of Hydraulic Systems
Table of contents (4 Examples)
8.1 Hydraulic System of Power-Slipway for Combined
Machine Tools 8.2 Hydraulic System for Plastic Injection Moulding Machine 8.3 Hydraulic System of YA32-200 Type Four Column
(2) Close the mould-chamber quickly (1YA＋、2YA＋、3YA＋).
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Chapter 8 Examples of Hydraulic Systems
(3) Low pressure and slow speed (2YA＋、3YA＋、13YA＋).
(4) High pressure (2YA＋、3YA＋).
Universal Press Machine
8.4 Hydraulic System of Manipulators
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Chapter 8 Examples of Hydraulic Systems 8.1 Hydraulic System of Power-Slipway for combined Machine Tools
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Chapter 8 Examples of Hydraulic Systems
8.2 Hydraulic System for Plastic Injection Moulding Machine
8.2.1 Introduction The injection moulding processing is shown below: Closing mode chamber → injection seat moving onwards