Lockable reversing valve

Abstract

The invention discloses a lockable reversing valve. A valve sleeve with a bore is mounted in at least one working oil port of a valve body, one end, which is close to a slide valve, of the valve sleeve is provided with a guide sleeve, a push rod is arranged in the guide sleeve, and the slide valve is provided with a conical surface between the push rod and an oil inlet; a spool is arranged in the valve sleeve over the push rod, a limit seat is arranged in the valve sleeve over the spool, a pilot spool is arranged in the bore of the lower part of the spool, a pilot valve restoring spring is arranged between the pilot spool and the upper end of the spool, and a restoring spring is arranged between the spool and the limit eat; the valve sleeve is provided with an axial hole, an oil cavity is arranged in the valve sleeve outside the spool, an annular cavity is arranged between the middle section of the valve sleeve and the valve body, a lower radial hole and an upper radial hole are arranged in the valve sleeve, and a radial damping hole is arranged in the spool. When the slide valve needs to be restored, control force does not need to be increased, and thereby controlling comfort and no leakage are ensured; moreover, the lockable reversing valve is convenient to machine, demount and mount, and is highly universal.

Description

technical field [0001] The invention relates to a reversing valve with a lock, in particular to a reversing valve with a lock used in a hydraulic system of a tractor. Background technique [0002] Tractor is a multi-purpose, high-efficiency, and flexible agricultural machinery. If the corresponding attachments are replaced, it can perform operations such as loosening soil, plowing, and harvesting. Because of its economical applicability, traditional tractors have high cost control, so the performance requirements are not very high, as long as they can be used. At present, people have higher and higher requirements for the performance of tractors, such as operating comfort, safety, etc., which puts forward new requirements for the reversing valve in the hydraulic system of the main engine: on the one hand, it is necessary to solve the control problem of multiple reversing valves On the other hand, solve the static settlement of the lifting cylinder to ensure no leakage. ...

AI Technical Summary

Problems solved by technology

Traditionally, the simplest solution to ensure static settlement is to control the internal leakage of the valve and reduce the fit gap between the slide valve and the valve body. However, in order to ensure the reset of the slide valve, the operating force needs to be increased, which reduces the operating comfort; the other is no leakage. The solution is to increase the hydraulic control one-way lock, but this solution will increase the difficulty of casting the valve body, the cost is high, and it has no commonality with the general working valve body

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