Pressure compensation valve and engineering machinery

Abstract

The invention relates to the technical field of engineering machinery, and discloses a pressure compensation valve and engineering machinery. The pressure compensation valve comprises a valve body and a valve core which is movably arranged in the valve body, wherein a load cavity and a control oil cavity are formed between the first end of the valve core and the valve body; an oil inlet cavity is formed between the second end of the valve core and the valve body; and a constant pressure oil source passageway communicated with the control oil cavity, a load feedback oil source passageway communicated with the load cavity and an oil inlet source passageway communicated with the oil inlet cavity are formed in the valve body. When the pressure compensation valve is used, constant pressure of the control oil cavity serves as a fixed value parameter for comparing a load feedback oil source and an oil inlet oil source. Compared with the prior art, the pressure compensation valve has the advantages that before and after pressure difference of the pressure compensation valve is always kept constant and cannot be changed along with difference of displacement of the valve core; the control precision is improved, and the service life is prolonged; and moreover, parts such as a spring which have relatively high quality requirements are not used, so that the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of construction machinery, in particular to a pressure compensation valve and construction machinery. Background technique [0002] Pressure compensation technology is widely used in hydraulic systems. figure 1 It shows a common pressure compensation valve in the prior art. As shown in the figure, during use, the main oil circuit is connected to the front of the pressure compensation valve, and the oil source for load feedback is connected to the back of the valve, so that the valve core The balance is achieved under the action of the oil source before the valve, the oil source behind the valve and the spring, so as to realize the constant flow of the system. [0003] But this form of pressure compensating valve has the following defects and deficiencies: 1. The theoretical basis of this pressure compensating valve is that its active force remains constant when the spring is slightly displaced, but in fact,...

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Problems solved by technology

[0003] But this type of pressure compensating valve has the following defects and deficiencies: 1. The theoretical basis of this pressure compensating valve is that the force of the spring remains constant when the spring is slightly displaced, but in fact the displacement of the valve core is generally small (about 10mm), and the compression deformation of the spring will cause its force to change; therefore, there is a certain deviation between the actual and the theory, the calculation error is large, and the compensation amount is different at different flow rates and openings; generally In other words, the greater the stiffness of the spring, the smaller the pre-compression, the greater the displacement of the spool, and the greater the effect difference

2. Due to the high movement frequency of the compensation valve, the spring is prone to fatigue deformation or fracture, which will affect the accuracy of the compensation valve or cause damage to the compensation valve. Therefore, the quality control requirements for the spring are high

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