JPH0474781U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment of the present invention, showing the valve body part; Figs. 2, 3, and 4 are explanatory diagrams of the operation when the spool is moved to the right in Fig. 1; Fig. 5 The figure is a configuration diagram of another embodiment of the present invention using a single solenoid; Figure 6 is an explanatory diagram of the operation of the embodiment of Figure 5; Figure 7 is a conventional electromagnetic switching valve (two
Fig. 8 is an explanatory diagram showing the effect of the tapered surface taken out from the valve body part of Fig. 7; Fig. 9 is a spool with which the pump port, load port, and tank port all communicate in a neutral manner. It is an explanatory view showing a problem when a tapered surface is provided in the type (0 type). Explanation of symbols, 1...Valve body, 2...Pump, 3
... Tank, 4 ... Cylinder (load), 5 ... Spool, 6a, 6b, 6 ... Spring chamber, 7a
, 7b, 7...Spring, 8a, 8b...Solenoid, 9a, 9b...Coil, 10a, 10b
...Movable iron core, 11a, 11b...Output rod,
12...Bypass passage, 13a, 13b, 13...
...Tank chamber, 24a, 24b, 24...Tapered surface, 25...Edge portion, 26...Stepped portion, 27...
Small diameter tapered surface, 28, 29, 30a, 30b...
Land, 32...Streamline.

Claims (1)

[Claims for Utility Model Registration] (1) A valve body having a spool hole that communicates with a pump port, a tank port, and at least first and second load ports; Re,
a spool that connects or disconnects the first and second load ports with the pump port and the tank port; a pair of springs that are incorporated in spring chambers formed at both ends of the spool hole and that hold the spool in a neutral position; and; disposed on both sides of the valve body, and by energizing either side, the spool is moved from the neutral position to the first position.
a pair of solenoids driven to a switching position or a second switching position; and a tapered surface is formed on the land end surface of the spool on the tank chamber side, and the load is reduced by movement of the spool. An electromagnetic switching valve characterized in that the tapered surface is formed at a position that prevents the flow from colliding with an edge of a spool hole opening that is continuous with the tank port of the valve body until the flow from the port to the tank chamber is substantially blocked. . (2) a valve body having a spool hole communicating with a pump port, a tank port, and a single load port; slidably incorporated into the spool hole of the valve body;
a spool that connects or disconnects the load port from the pump port and the tank port; a spring that is incorporated into a spring chamber formed at one end of the spool hole and holds the spool in a neutral position; one side of the valve body. a single solenoid disposed in the spool and driving the spool from a neutral position to a switching position by energization; in the electromagnetic switching valve, a tapered surface is formed on the land end surface of the spool on the tank chamber side; The tapered surface is formed at a position that does not allow the flow to collide with the edge of the spool hole opening connected to the tank port of the valve body until the flow from the load port to the tank chamber is substantially blocked by movement of the spool. Features a solenoid switching valve. (3) The electromagnetic switching valve according to claim 1 or 2, characterized in that the electromagnetic switching valve has a two-step tapered surface in which a small diameter tapered surface is formed via a stepped portion with respect to the tapered surface.