JPH0539243Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a directional control valve suitable for industrial machines used in working environments with a lot of suspended dust, such as general industrial machines, powder machines, and textile machines. It is related to.

[Prior Art] In general industrial machinery, powder processing machinery, textile machinery, etc., jet energy of air is used to transfer or blow away workpieces.
In order to blow out or shut off this pressurized air, a directional control valve is used that switches the flow of air using an external force.

FIG. 3 shows an example of a known directional control valve, in which a valve body 1 has a valve seat 5 in a passage 4 that communicates an inlet port 2 and an outlet port 3 opened in the body 1, and A pair of lid insertion holes 6a and 6b are provided facing each other in the forming direction.

The retainer 7, which is airtightly attached to the lid insertion hole 6a, has a recess 7a that opens on the valve seat side, and is prevented from coming off in the axial direction by a retaining ring 8.
The valve body 9 that opens and closes the valve seat 5 is slidably inserted into the recess 7a, and is biased in the closing direction of the valve seat 5 by the biasing force of a return spring 10 compressed between it and the retainer 7. , the output port side of the passage 4 and the recess 7a are
They communicate through a passage 9a formed in the valve body 9. Further, the cover 12, which is airtightly attached to the lid insertion hole 6b, is restricted from moving in the axial direction by the seat plate 13 and the retaining ring 8.
The push rod 14 that slides on the valve body 2a is supported by a support spring 15 and has a tip protruding outward from the valve body 1, and has the other end facing the valve body 9, and its outer periphery is sealed with a seal ring 16. has been done.

In the above-mentioned directional switching valve, when the tip of the push rod 14 is pressed by an appropriate means (not shown), the valve body 9 is driven by the sliding of the push rod 14 against the biasing force of the return spring 10, and the valve body 9 is opened. Since the seat 5 opens, the pressurized air in the inlet port 2 flows out from the outlet port 3, and when the pressure on the push rod 4 is released, the valve body 9 and the push rod 14 are returned to their original positions by the urging force of the return spring 10 and the support spring 15. The state will be restored.

In the above-mentioned directional switching valve, since the outer periphery of the push rod 14 is sealed by the seal ring 16, air is not wasted when the valve seat 5 is opened.
When used in a work environment with a lot of floating dust such as general industrial machinery, powder machinery, textile machinery, etc., floating dust, fibers, etc. will adhere to the protruding part of the push rod 14 and enter its sliding part. do. Dust adhering to the push rod 14 and its sliding parts absorbs the lubricating oil of the sliding parts, resulting in poor lubrication of the push rod and increased sliding resistance, causing the valve body to fail to return or return to its original state. The problem is that it becomes impossible.

[Problem to be solved by the invention] The purpose of the invention is to create a directional control valve that can be used for a long period of time even in work environments with a lot of floating dust by removing floating dust attached to the push rod each time the push rod is pressed. It is about providing.

[Means for Solving the Problems] In order to solve the above problems, the directional control valve of the present invention includes a valve body having an inlet port, an outlet port, and a valve seat in a passage that communicates these ports;
A valve element that opens and closes the valve seat, a return spring that biases the valve element in the closing direction of the valve seat, and a tip that protrudes outside the valve body from the outlet port side of the valve seat and presses the valve element by sliding. In a directional control valve equipped with a push rod that opens the valve seat, the sliding clearance of the push rod between the outer circumferential surface of the push rod and the inner circumferential surface of the through hole of the valve body in which the push rod slides is defined as the sliding clearance between these surfaces. It is characterized by a ventilation passage for removing dust that has adhered to the surface and that has entered from the outside.

[Function] When the push rod is slid by an external force, the valve seat opens and the pressurized air in the inlet port flows out to the outlet port, and a portion of the air flows outside through the sliding clearance of the push rod, which serves as a ventilation path. Since the air flows out, floating dust adhering to the push rod and the through hole that enters from the outside is removed by this pressurized air.

Dust is removed by the pressurized air each time the valve seat is opened by pressing the push rod, and the time for the dust to adhere to the push rod and valve hole surface is short, so even when used in a work environment with a lot of floating dust, the sliding part It can be used for a long time without causing poor lubrication.

[Embodiment] Figures 1 and 2 show an embodiment of the present invention, in which a valve body 1 in this directional control valve has an inlet port 2.
A valve seat 5 is provided in the passage 4 that communicates with the outlet port 3, and the valve body 9 that opens and closes the valve seat 5 is connected to the retainer 7.
The valve seat 5 is biased in the direction of closing by a return spring 10 contracted between the valve seat 5 and the valve seat 5.

The cover 20 airtightly attached to the lid insertion hole 6b of the valve body 1 is provided with an axial through hole 20a, and there is a gap between the outer peripheral surface of the push rod 21 inserted into the through hole 20a and the inner peripheral surface of the through hole 20a. A ventilation passage 22 is formed by the sliding clearance of the push rod 21 .

The directional switching valve has a through hole 20a in the cover 20.
The directional control valve has the same structure as the directional control valve shown in FIG. 3, except that the ventilation passage 22 is formed in the sliding part of the push rod 21 and the seal ring 16 is not provided. The same reference numerals are used to omit detailed explanation.

In the above embodiment, when the tip of the push rod 21 is pressed by an appropriate means in the state shown in FIG. 1 where the valve body 9 closes the valve seat 5, the push rod 21 slides and the valve body 9 opens the valve seat 5, and the pressurized air in the inlet port 2 flows out from the outlet port 3, and a portion of it is discharged to the outside through the air passage 22 (see FIG. 2).

Therefore, floating dust such as dust and fibers adhering to the push rod 21 while the valve seat 5 is closed is removed by the pressurized air passing through the ventilation path 22. Furthermore, since this dust is removed each time the push rod 21 slides, the adhesion time of the floating dust to the sliding parts is short, and the absorption of lubricating oil (grease) by the floating dust is also small. Even if the valve body is used for a long period of time in a busy work environment, failure or inability to return the valve body due to a decline in the lubrication function can be prevented.

When the pressure on the push rod 21 is released, the valve body 9 and the push rod 2
1 is returned to its original state by the urging force of the return spring 10 and the support spring 15.

[Effects of the invention] The directional control valve of the present invention has a pressure air discharged to the outside through the sliding clearance of the push rod, which serves as a ventilation path, each time the valve seat opens due to sliding of the push rod. Floating dust that has entered the sliding part from the outside and adhered to the valve hole is removed, so there is no lubrication failure of the sliding part due to floating dust, so the valve can be used for a long time in a working environment with a lot of floating dust. It is possible to prevent failure or inability to recover the body.

Furthermore, since the sliding clearance of the push rod is used as a ventilation path, the configuration is extremely simple.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing the valve seat in the closed state in an embodiment of the present invention, Fig. 2 is a longitudinal sectional front view showing the same valve seat in the open state, and Fig. 3 is a longitudinal sectional front view of a known directional control valve. It is. 1... Valve body, 2... Inlet port, 3... Outlet port, 4... Passage, 5... Valve seat, 9... Valve body,
10... Return spring, 21... Push rod, 22... Ventilation path.

Claims (1)

[Claims for Utility Model Registration] A valve body having an inlet port, an outlet port, and a valve seat in a passage that communicates these ports, a valve body that opens and closes the valve seat, and a valve body that opens and closes the valve seat, and a valve body that opens and closes the valve seat. In the directional control valve, the directional control valve is equipped with a return spring that biases the valve seat in the direction, and a push rod whose tip protrudes from the outlet port side of the valve seat to the outside of the valve body and slides to press the valve body and open the valve seat. The sliding clearance of the push rod between the outer peripheral surface of the valve body and the inner peripheral surface of the through hole of the valve body through which the push rod penetrates is used as a ventilation path for removing dust adhering to these surfaces and entering from the outside. A directional valve featuring: