A hydraulic control circuit

Abstract

The invention provides a hydraulic control loop. The hydraulic control loop comprises an oil tank, a first reversing valve, a second reversing valve, a one-way valve, a hydraulic control one-way valve, a digital relief valve, a controller and the like. An oil cylinder comprises a first chamber and a second chamber. The oil tank is connected with an oil pump which is communicated with the first reversing valve through a first pipeline. The one-way valve and the hydraulic control one-way valve are sequentially connected between the first reversing valve and the first chamber of the oil tank respectively. The first reversing valve is communicated with a control opening of the hydraulic control one-way valve which is communicated with the one-way valve through a second pipeline. The digital relief valve is arranged on the second pipeline. The second chamber of the oil cylinder is communicated with the second reversing valve which is communicated with the second pipeline and the first pipeline respectively. A displacement detector is connected with a piston of the oil cylinder. The first reversing valve, the second reversing valve and the digital relief valve are respectively connected with the controller. According to the simplified technical scheme, unloading speed is adjusted, oil returning is rapid, and requirements of actual working conditions are met with high practicability.

Description

technical field [0001] The invention relates to the field of hydraulic control systems, in particular to a hydraulic control circuit for adjusting unloading speed. Background technique [0002] In the hydraulic system, some functions are often required, such as no need for hydraulic pumps to supply oil, hydraulic cylinders or hydraulic motors that need to stop working for a short time, or actuators that can slow down or even stop working for a certain period of time, etc. Under normal circumstances, we usually require the hydraulic pump not to output oil or only need hydraulic oil with a small flow rate or to perform rapid pressure relief, so most of the oil output by the hydraulic pump flows back to the oil tank through the overflow valve, which will cause the oil Heat, increase energy consumption, but also affect the performance of the hydraulic system and the service life of hydraulic components. [0003] In the prior art, a hydraulic unloading circuit is usually used to...

AI Technical Summary

Problems solved by technology

[0004] Reversing valve unloading is adopted. When this unloading method is switched, the pressure shock is large. At the same time, an ordinary check valve needs to be placed in the oil return line. The impact phenomenon is easy to occur when the valve is reversing, and the practicability is not strong.

[0005] Relief valve is used for unloading. In this way of unloading, a two-position two-way valve must be connected in parallel in the circuit to form a composite valve. At the same time, the structure of the overflow valve must be a pilot-operated structure. Only in this way can the unloading of the hydraulic pump be realized. Load, this loop has hysteresis, the accuracy is not high

[0006] Sequence valve unloading is adopted. This unloading method mainly uses the change of oil circuit pressure to control the opening of the sequence valve, so that the hydraulic pump is unloaded through the hydraulic control sequence valve. It requires high precision in the control of main oil circuit pressure changes. It is prone to misoperation of the hydraulic control sequence valve, which affects the unloading of the hydraulic pump

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