Oil return and distribution system for telescopic arm cylinder of aerial work vehicle

Abstract

The telescopic boom cylinder oil return and distribution system of the aerial work vehicle includes a multi-way reversing valve, a balance control valve and an oil cylinder. The A port of the multi-way reversing valve is connected to the rodless chamber oil port C1 of the oil cylinder through the balance control valve. Port B of the reversing valve is connected with the control port K1 of the balance control valve and the oil port C2 of the rod chamber of the oil cylinder, and the oil port C2 of the rod chamber of the oil cylinder is connected with the control port K1 of the balance control valve. A throttle valve and a balanced oil return valve are also connected in series between the A port and the B port of the directional valve. The control port K2 of the balanced oil return valve is connected to the B port of the multi-way reversing valve. The valves are all connected to the oil tank through the switch valve. In the telescopic arm oil cylinder oil return and distribution system of the aerial work vehicle of the present invention, a balance oil return valve is added between the A port and the B port of the multi-way reversing valve, and a throttle valve is added at the B port of the multi-way reversing valve Oil return, to achieve the purpose of oil return and diversion, and solve the problem of shock and vibration when the oil cylinder starts to retract.

Description

technical field [0001] The invention belongs to the field of hydraulic control, in particular to an oil return and diversion system for a telescopic arm oil cylinder of an aerial work vehicle. Background technique [0002] At present, telescopic arm type aerial work vehicles and truck cranes all use telescopic oil cylinders as executive parts for their telescopic booms, and the sleeves of the booms are driven by the oil cylinders to extend and retract. In order to obtain a larger bearing capacity and enhance the stability of the cylinder, the area ratio of the telescopic arm cylinder (the ratio of the area of ​​the rodless cavity to the area of ​​the rod cavity, assuming N) is relatively large. At the same time, in order to prevent the retraction speed from being too fast and out of control, a balance valve is generally installed in the rodless chamber of the oil cylinder. [0003] The control system of the existing telescopic arm oil cylinder is as follows: figure 1 As sh...

AI Technical Summary

Problems solved by technology

[0005] 1. A large amount of hydraulic oil is returned through the A port of the multi-way directional control valve 1, and the oil return flow rate is greater than the rated flow rate of the multi-way directional control valve 1, so that a large oil return is generated at the A port of the multi-way directional control valve 1. Back pressure, the extra back pressure in this part will cause additional energy loss;

[0006] 2. When a large oil return back pressure is generated at the A port of the multi-way directional valve 1, the pressure of the oil return back pressure will be superimposed on the oil inlet P of the multi-way directional valve 1. When the pressure of the oil inlet P If the setting value of the overflow valve is exceeded, the hydraulic oil entering the oil inlet P of the multi-way reversing valve will overflow through the overflow valve under high pressure, resulting in a large energy loss, resulting in slow retraction of the oil cylinder;

[0007] 3. Because it is necessary to establish the rod cavity pressure of the oil cylinder first, and then the balance valve will switch to open, so when the oil cylinder first retracts, a high-pressure shock will be generated, causing the oil cylinder to shake

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