Indirect control type digital servo valve

Abstract

The invention provides an indirect control type digital servo valve. According to the technical scheme, digital quantity control is adopted, the driving force of a valve element is large, the valve element is not prone to jamming, the anti-pollution capability of the servo valve is improved, the control of a main valve element can be realized without arranging a sensor, so that the control loop issimplified. In order to achieve the aim, the indirect control type servo valve comprises a valve body, the main valve element and a pilot valve element, the main valve element is provided with an oilinlet passage, an oil return passage and a control oil passage, the area of the axial two ends of the main valve element is unequal, the valve body is provided with a control oil cavity communicatingwith the control oil passage at the end, which is large in area, of the main valve element, and is provided with a high-pressure oil cavity communicating with high-pressure oil at the end, which is small in area, of the main valve element, one end of the pilot valve element extends into the main valve element in an axial direction so as to enable the control oil passage and the oil inlet passageor the oil return passage to communicate through axial movement, so that the two ends of the main valve element form the differential pressure for axial movement, then the working positions of the valve are switched, and the continuous adjustment of the flow is realized.

Description

technical field [0001] The invention relates to the technical field of servo valves, in particular to a large flow indirect control digital servo valve. Background technique [0002] As the industry develops towards automation, more and more hydraulic control systems use servo systems, and the core control components of hydraulic servo systems are servo valves, whose quality directly determines the control accuracy and reliability of the system. [0003] The conventional large diameter servo valve is composed of a main valve and a pilot valve, and a displacement sensor is installed on the main valve core. By detecting the displacement of the main valve core, the closed-loop control of the main valve core is realized by controlling the pilot valve. The structural forms of the pilot valve include nozzle baffle servo valve, jet tube servo valve, and direct-acting high-response servo valve. [0004] The nozzle baffle servo valve is the most common servo valve at present. It ado...

AI Technical Summary

Problems solved by technology

However, due to the limited driving force of the proportional linear bidirectional motor (less than 150N), the stroke is short, the anti-pollution ability is limited, and the control is complex, it is prone to failures such as pilot valve core jamming and control board burning.

[0007] It can be seen that the above servo valves all have the problem of poor anti-pollution ability, and are prone to failure due to deterioration of oil quality

[0008] Moreover, the main spool is detected by a displacement sensor, and an integrated closed-loop control loop is set for control. The control is complicated, the cost is high, and the failure rate is high.

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