JP2968084B2 - Fluid control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid control valve having an orifice which can be used as a throttle element by displacement of a spool.

[0002]

2. Description of the Related Art Conventionally, as an example of this type of fluid control valve,
There are those as shown in FIGS. In both drawings, passage holes 1a and 1b are formed in the sleeve 1, and the passage holes 1a and 1b are respectively connected to the inflow / outflow fluid passages 4a and 4b.
It is connected to the. As shown in FIG.
When the spool 2 is at the return position (a), it is closed by the land 2a, and opens when the spool 2 is displaced to the right as shown in FIG. 4, so that fluid can flow freely between the passages 4a and 4b. When the spool 2 is at the return position in FIG. 3A, the orifice notch 2b formed on the land 2a acts as a throttle element between the passage holes 1a and 1b.

[0003]

However, in such a conventional fluid control valve, when dust in the fluid adheres to the orifice notch 2b of the spool 2, the dust is difficult to remove from the spool 2, and the dust is difficult to remove. The required valve operation may not be possible due to the adhesion of the fluid passage hole 1.
Screens 9A and 9B for filtration were provided on a and 1b, and these screens 9A and 9B had to be periodically cleaned, which increased costs.

Accordingly, an object of the present invention is to provide a low-cost fluid control valve capable of easily washing off dust attached to an orifice groove by a flow of fluid in a normal operation.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a fluid control valve in which a spool is slidably housed in a valve body and opening and closing of a radial passage hole of the valve body is controlled by movement of the spool. In the inner peripheral wall portion of the valve body, an orifice groove having one end connected to the radial passage hole and the other end extending in the axial direction of the valve body is provided, and the spool closes the radial passage hole. Then, an orifice passage is formed by the orifice groove.

[0006]

According to the present invention, when the spool closes the radial passage hole, the orifice passage is formed by the orifice groove formed in the valve body wall. Therefore, even if dust adheres to the orifice groove at this time, when the spool opens the radial passage hole, the dust is easily washed away by the flow of the fluid through the radial passage hole.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 and 2 are views showing one embodiment of a fluid control valve according to the present invention. 1 and 2, reference numeral 11 denotes a cylindrical sleeve (valve element), 12 denotes a spool slidably housed in the sleeve 11, and 13 denotes a spring for urging the spool 12 to the left in the figure. These are housed in the valve housing 14. Outflow / inflow passage holes (radial passage holes) 11a and 11b are formed on the peripheral wall of the sleeve 11 at a predetermined distance, and these passage holes 11a and 11b are formed in the valve housing 14.
Are connected to fluid passages 14a and 14b. The spool 12 receives the urging force of the spring 13 to abut its flange portion 12a against one end surface of the sleeve 11, and closes one of the passage holes 11b by the land portion 12b at the abutting (stopping) position. Also, the small diameter portion 12c of the sleeve 11 and the spool 12
An annular passage 15 is defined between them, and the other passage hole 11a of the sleeve 11 is always open and communicates with the annular passage 15. Further, the sleeve 11 and the spool 12 define a control pressure chamber 17 communicating with the control pressure passage 16 between the sleeve 11 and the spool 12, and the fluid pressure in the control pressure chamber 17 rises to a predetermined pressure in the spool 12. The spring receives the fluid pressure
13 is displaced to the right in the figure against the urging force of thirteen. In the drawing, reference numeral 18 denotes a drain passage for constantly draining the spring storage chamber 14c of the valve housing 14.

On the other hand, the inner peripheral wall of the sleeve 11 is provided with an orifice groove 21 having one end connected to the passage hole 11b and the other end extending in the axial direction of the sleeve 11. When the spool 12 closes the passage hole 11b, the orifice groove 21 forms an orifice passage 20 communicating the annular passage 15 and the passage hole 11b between the spool 12 and the spool 12. It functions as a valve. Further, when the supply fluid pressure to the control pressure chamber 17 increases and the spool 12 is displaced as shown in FIG. 2 (to the right in the figure),
The passage hole 11b is opened and the annular passage 15 and the passage hole 11 are opened.
b communicates with a sufficient passage area.

That is, in the present embodiment, the spool 12 is slidably housed in the cylindrical sleeve 11, and the displacement of the spool 12 to a predetermined position causes the outflow / inflow passage hole 11 to move.
A passage 50 (corresponding to the annular passage 15 in this state) is formed to allow the orifice 20 to communicate with the orifice passage 20 between the outflow / inflow passage holes 11a and 11b by displacement of the spool 12 to another predetermined position. Is formed.

In this embodiment having such a configuration, when the supply control pressure to the control pressure chamber 17 is equal to or lower than a predetermined value, the spool 12 is urged to the left side in the figure by the urging force of the spring 13. To the sleeve 11. At this time, the fluid control valve acts as a throttle valve. In this state, the flow rate between the outflow / inflow passages 11a and 11b is small, and dust (abrasion powder from a fluid source or a fluid pressure actuator) contained in the fluid easily adheres to the orifice passage 21.

However, in this embodiment, the spool 12
When the passage hole 11b is opened due to the displacement, the dust in the orifice groove 21 connected to the passage hole 11b is easily washed away by a relatively large amount of fluid passing through the passage hole 11b (by a so-called washout effect). Therefore, it is not necessary to provide a screen in the inflow / inflow passage or perform a cleaning operation as in the related art, and it is possible to prevent the orifice groove 21 from being clogged. As a result, the orifice groove
It is possible to provide a low-cost and highly reliable fluid control valve that can easily wash away dust attached to the 21 by a fluid flow in a normal operation.

[0012]

According to the present invention, when the spool closes the radial passage hole, the orifice passage is formed by the orifice groove formed in the wall surface of the valve body. Therefore,
Even if dust adheres to the orifice groove, the dust can be easily washed away by the flow of fluid through the radial passage hole when the spool opens the radial passage hole, and the dust can be removed by the flow of fluid during normal operation. It is possible to provide a low-cost and highly reliable fluid control valve that can be easily washed away.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a fluid control valve according to the present invention, wherein (a) is a longitudinal sectional view thereof, and (b) is a B1-B1 view thereof.
It is sectional drawing.

FIG. 2 is a longitudinal sectional view showing a displacement state of a spool in one embodiment.

FIG. 3 is a diagram showing an example of a conventional fluid control valve;
(A) is a longitudinal sectional view thereof, and (b) is a B3-B3 sectional view thereof.

FIG. 4 is a longitudinal sectional view showing a state of displacement of a spool in a conventional example.

[Description of Signs] 11 Sleeve (valve element) 11a, 11b Outflow / inflow passage hole (radial passage hole) 12 Spool 13 Spring 14 Valve housing 15 Annular passage 16 Control pressure passage 17 Control pressure chamber 20 Orifice passage 21 Orifice groove 50 aisle

Claims (1)

(57) [Claims] 1. A fluid control valve in which a spool is slidably housed in a valve body and a radial passage hole of the valve body is controlled to be opened and closed by movement of the spool. Is provided with an orifice groove connected to the radial passage hole and the other end side extends in the axial direction of the valve body. When the spool closes the radial passage hole, an orifice passage is formed by the orifice groove. Characteristic fluid control valve.