Direct-acting type proportional throttle valve

Abstract

The invention discloses a direct-acting type proportional throttle valve which is composed of a valve body (1b), a valve core (2b), a valve sleeve (3b) and a spring (4b). The direct-acting type proportional throttle valve is characterized in that the valve core (2b) is provided with a conical surface (c) and an oil groove (G), the maximum outer diameter of the conical surface is D, the diameter of an outer circle of the valve core on the small-end side of the conical surface C is d, and D is larger than d; the valve body (b) is provided with an oil opening A and an oil opening B, the valve core (2b) and the valve body (1b) are assembled into a transition containing cavity V; spring force is applied to one end of the valve core (2b), and control force Fc is applied to the other end of the valve core; the valve sleeve (3b) is arranged on the side provided with the spring (4b). According to the direct-acting type proportional throttle valve, for a miniature hydraulic system of special purposes such as a small-size/heavy-load robot, internal leakage of the proportional throttle valve in the closed state is greatly reduced; the internal leakage is not changed obviously when the fit clearance of a valve hole of the valve core is slightly raised due to normal abrasion, so that reliability of the proportional throttle valve is improved, and the service life is prolonged; a valve opening can achieve zero covering, no control dead zone exists, and the response speed is raised.

Description

technical field [0001] The invention belongs to the field of hydraulic pressure, and in particular relates to a direct-acting proportional throttle valve, which is mainly suitable for miniature and small hydraulic systems. Background technique [0002] The schematic diagram of the typical structure of the traditional small flow direct-acting proportional throttle valve is shown in figure 1 , A slide valve spool A2a is installed in the valve hole of the valve body A1a, and a spring A3a is installed at the right end of the spool. There are oil chambers A and B on the valve body, and an oil groove G on the valve core. In the initial state, chamber A and chamber B are not connected. When the control force Fc (adjustable electromagnetic force or hydraulic pressure) is applied to the left end of the spool to overcome the preload of the spring A3a at the right end, the spool moves to the right, and chamber A It is gradually connected with chamber B through oil groove G. By adjus...

AI Technical Summary

Problems solved by technology

[0009] 2) Slow response

[0010] In the proportional throttle valve of the prior art, in order to ensure the effective isolation between A and B chambers in the closed state, the valve port must be designed to be positively covered (the covering amount is the distance X from the top of the oil tank G to the B chamber), and the covering amount X cannot be designed too small, otherwise the sealing effect will be worse

This directly leads to the increase of the control dead zone and the extension of the response time

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