Pilot control valve capable of operating stably

Abstract

The invention relates to a pilot control valve capable of operating stably. The pilot control valve is characterized by comprising a valve body provided with a piston cavity, a first damping hole, a one-way valve core, a control piston and a second spring, wherein an end cap is fixed at the front end of the valve body, and a liquid outlet channel and a liquid inlet channel are formed in the end cap; the first damping hole is formed in the liquid inlet channel and enables the outside to communicate with the piston cavity; the one-way valve core is arranged in the liquid outlet channel; the piston cavity is divided into a rod cavity and a rodless cavity by the head part of the control piston, a second damping hole is formed in the control piston, and a rod part of the control piston penetrates out of the top wall of the rod cavity; the second spring is arranged in the rod cavity and acts on the head part of the control piston so as to enable the control piston to keep an axial moving trend in a direction facing the end cap. The pilot control valve is reasonable in structure, and can stably control opening of a pilot valve core of a balance valve without being distributed by pressure fluctuation.

Description

technical field [0001] The invention relates to a pilot control valve, in particular to a stable pilot control valve capable of stably controlling the opening of a valve core of a hydraulic balance valve. Background technique [0002] In modern engineering machinery, construction machinery and other mechanical equipment, a large number of lifting hydraulic circuits are used. In the boom extension and retraction systems of concrete pump trucks, balance valves are usually used for hydraulic locking to ensure that the boom can be positioned at any position. Reliable stay. Among them, the balance valve is the key hydraulic component of the load control system and the hydraulic bearing system, and the performance of the balance valve directly affects the operation quality of the main engine. With the increasing difficulty of concrete pump truck operation, the requirements for sealing, self-locking, stability and multi-functionality of the balance valve are getting higher and hig...

AI Technical Summary

Problems solved by technology

The pilot control stage only has a decompression circuit composed of 2 dampers. When the control pressure at the X port fluctuates greatly due to load changes, it cannot play a good buffering role, which will cause the opening of the balance valve spool to change, causing the hydraulic cylinder to vibrate. , which can cause severe shaking of the main engine on long-arm operating equipment such as aerial work vehicles or concrete pump trucks, seriously affecting operating safety and operating accuracy

In the decompression circuit composed of the pilot control stage, a part of the oil directly flows back to the oil tank. In the large flow system, the oil return has not much influence, but in the small flow system or the pilot composed of accumulators In the handle control circuit, the flow loss of this part flowing back to the fuel tank is very large, which seriously limits the application of this invention

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