Differential valve

Abstract

The invention discloses a differential valve. The main technical point is that a first flow circuit and a second flow circuit which are not mutually communicated are arranged on a slide valve core. When the slide valve is located on a first working position, a first pilot-controlled port of a valve body is communicated with a first flowing liquid port of the valve body through the first flow circuit, and a second pilot-controlled port of the valve body is communicated with a second flowing liquid port of the valve body through the second flow circuit. When the slide valve is located on a second working position, the second pilot-controlled port is directly communicated with the second flowing liquid port of the valve body, and the second pilot-controlled port of the valve body is communicated with the first flowing liquid port of the valve body through the second flow circuit of the slide valve. The moving speed of a hydraulic cylinder piston is increased over two times under the situation of no changing the flow of a hydraulic pump. If the differential valve is installed on a horizontal broaching machine, which will greatly reduce the return time of a broaching tool, and increase the working efficiency of the broaching machine.

Description

technical field [0001] The invention relates to the technical field of valves, in particular to a valve that enables hydraulic cylinder pistons to have different movement speeds when high-pressure oil is respectively fed into a rod chamber or a rodless chamber of a hydraulic cylinder. Background technique [0002] For a horizontal broaching machine, the broach is fixed together with the piston rod of the hydraulic cylinder through a collet. Under the control of the hydraulic system, the broaching operation is realized when the piston rod retracts, and the broaching operation is realized when the piston rod is extended. return. Since the broach and the piston rod are pulled when retracting, the rigidity is good and it is not easy to deform, so the accuracy of the workpiece can be guaranteed. When the broach is stretched out, it is an empty stroke and is not subject to broaching force, thus avoiding the broach and piston rod. It is easy to lose stability in the compressed sta...

AI Technical Summary

Problems solved by technology

From the perspective of improving work efficiency, the return time of the broach should be as short as possible. However, in the known technology, when the broach returns, the rodless chamber of the hydraulic cylinder is a high pressure chamber, and the rod chamber is a low pressure chamber. When the broach is broaching, the rod chamber of the hydraulic cylinder is a high-pressure chamber, and the rodless chamber is a low-pressure chamber. Since the effective cross-sectional area of ​​the rodless chamber is larger than that of the rod chamber, at the same flow rate Under the circumstances, the return speed of the broach is lower than the cutting feed speed of the broach, in other words, the return time of the broach is longer than the broaching time of the broach, which greatly reduces the working efficiency of the broach

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