JPH0440061Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a detent mechanism for a directional control valve, and more particularly, to a detent mechanism that utilizes magnetic force.

[Prior Art] Directional switching valves usually include a detent mechanism for maintaining the switching position of the valve body.

In the above detent mechanism, when the valve body has a sealing member made of an elastic body, it may be held by utilizing the sliding resistance of the sealing member, but since the holding force is small, safety considerations must be taken into consideration. A separate day tent mechanism is often provided.

Furthermore, if the valve body is a metal seal, the valve body itself does not have a holding force, so a separate detent mechanism is provided.

In the conventionally known detent mechanism, as shown in FIG. 4, for example, a locking groove 2 is formed on the outer peripheral surface of a valve body 1, and a plurality of balls housed in a detent body 3 are inserted into the locking groove 2. 4, . . . are pressed by springs 5, .

Therefore, on the valve body side, each time the valve body 1 slides, the balls 4, ... slide on the valve body, so sliding marks of the balls 4, ... are formed on the surface of the valve body 1. This increases the sliding resistance, which may result in slow response or malfunction due to abrasion powder caused by sliding. In addition, on the ball side, as the balls 4,... move inside the detent body 3, the balls may wear out and the holding force may decrease, or the balls 4,... may be damaged by abrasion particles.
There is a problem that the movement of the valves becomes slow, resulting in defective detents, and furthermore, the life of the valve is shortened due to wear of various parts.

In order to solve this problem, it is possible to use the magnetic force of a permanent magnet in the detent mechanism.
When the valve body and the permanent magnet collide, not only does abrasion powder occur, but depending on the material of the valve body, the magnetized valve body may attract abrasion powder, which can cause malfunctions, which is a new problem. be.

[Problem to be Solved by the Invention] The problem to be solved by the present invention is to provide a detent mechanism for a directional control valve that is free from malfunctions and decreases in responsiveness due to wear and has a long life.

[Means for Solving the Problems] In order to solve the above problems, the detent mechanism of the present invention includes a valve body having a plurality of ports, a valve body that switches a flow path between the ports, and a flow path of the valve body. In the directional control valve, the detent mechanism includes a ring attached to the outer peripheral surface of one end of the valve body, and a detent mechanism attached to the valve body, and the detent mechanism is attached to the valve body at the flow path switching position of the valve body. It is characterized in that it includes a holder that faces the outer peripheral surface of the ring, and one of the ring and the holder is made of a magnetic material, and the other is made of a permanent magnet.

Moreover, in order to solve the same problem, it is preferable to attach a pair of rings with a stroke interval between the valve bodies.

Furthermore, in order to solve the same problem, it is preferable to include a ring attached to the outer circumferential surface of both ends of the valve body, and two holders facing one of the rings at both switching positions of the valve body.

In addition, in order to solve the same problem, we have developed a ring,
It is best to attach it to the outer circumferential surface of a detent collar made of a non-magnetic material attached to the valve body.

[Operation] When the valve body slides and the flow path between ports is switched,
Since the outer circumferential surface of the ring constituting the detent mechanism and the holder face each other, the permanent magnet attracts the magnetic material and the flow path switching position of the valve body is maintained.

Since the above-mentioned detent mechanism does not have pressure contact parts such as balls and locking grooves, there is no decrease in responsiveness or holding force due to wear caused by pressure contact, and there is no malfunction. Further, since there is no collision between the ring and the holding body, it is possible to prevent a decrease in responsiveness and holding force due to wear caused by such collisions, and malfunctions.

Therefore, even after long-term use, there is no reduction in holding force or responsiveness, and the life of the valve can be extended.

In addition, a ring and a retainer made of a magnetic material and a permanent magnet are provided at one or both ends of the valve body and at positions facing the valve body, thereby preventing leakage of magnetic flux to the flow path sealing portion of the valve body. It can be made extremely small.

Further, a pair of rings may be provided at intervals between the strokes of the valve body, or a pair of rings may be provided at both ends of the valve body, and two rings may be provided opposite to one of these rings at both switching positions of the valve body.
Since two holding bodies are provided, the valve body can be held in both switching positions.

In addition, since the ring is provided on the outer circumferential surface of the non-magnetic detent collar attached to one end of the valve body, it can not only be attached to an existing valve body, but also
There is no need to perform complicated processing on the valve body.

[Example] Figures 1 to 3 show examples of the present invention,
This directional switching valve includes a valve body 11, a valve body 12, and a detent mechanism 13 that maintains the flow path switching position of the valve body 12.

The valve body 11 includes a pressure fluid supply port P,
Output ports A, B, discharge ports EA, EB, and an axial through hole 15 through which these ports open are provided, and a sleeve 16 having openings that individually communicate with the plurality of ports is installed in the through hole 15 in an airtight manner. The pilot chambers 18a, 1 are fitted on the plates 17a, 17b attached to both sides of the valve body 11.
8b is formed.

The spool-shaped valve body 12 is connected to the pilot chamber 18.
Pistons 19a, 19b installed in a, 18b
It slides inside the sleeve 16 by being pressed by the port P.
It switches the flow path between ports P and A and B and EB, and the communication between ports P and B and A and EA, and a small diameter portion 12a and a locking groove 20 are formed on the piston 19a side.

The detent collar 22 made of a non-magnetic material fitted into the small diameter portion 12a has a hook 23 that locks in the locking groove 20, an axial slit 24, . . .
A pair of grooves 25a and 25b are formed in the circumferential direction at intervals of the stroke of the valve body 12, and rings 26a and 26b formed of a magnetic material are fitted into these grooves.

On the other hand, a guide ring 28 fitted on the plate 17a side of the through hole 15 is fitted with a holder 29 made of a permanent magnet and a bush 30, and the ring 2
6a, 26b and the holding body 29 constitute the detent mechanism 13.

Although the holding body 29 is formed in an annular shape in the illustrated example, it may be divided in the circumferential direction.Alternatively, the rings 26a and 26b may be made of permanent magnets, and the holding body 29 may be made of a magnetic material. Good too.

FIG. 1 shows that the valve body 12 is pressed by a sliding piston 19a with pilot fluid supplied to the pilot chamber 18a, and the valve body 12 is connected to ports P, A, B, and EB.
In this position, the outer circumferential surface of the ring 26a and the inner circumferential surface of the holder 29 face each other in the radial direction, so that the magnetic force of the detent mechanism 13 causes the valve body 12 to be The switching position is maintained.

The valve body 12 is pressed by the piston 19b,
When switched to the second switching position where the flow paths between ports P and B and A and EB communicate with each other, the outer circumferential surface of the ring 26b and the inner circumferential surface of the holder 29 face each other in the radial direction.
Similarly, the magnetic force of the detent mechanism 13 causes the valve body 1 to
Two switching positions are maintained.

The detent mechanism 13 is composed of rings 26a and 26b provided on the outer periphery of one end of the valve body 12, and a holder 29 that faces the outer periphery of the ring at the switching position of the valve body. Since the valve body 12 is held by magnetic force, there is no pressure contact part like in known detent mechanisms, so it is possible to prevent an increase in sliding resistance due to wear, a decrease in holding force, or malfunctions due to wear particles. .

Moreover, even if the valve body 12 slides, the rings 26a and 26b constituting the detent mechanism 13 and the holding body 2
9 does not collide with each other, it is also possible to prevent wear of these parts due to collision.

Furthermore, the detent mechanism 13 is provided at one end of the valve body 12 to minimize leakage of magnetic flux to the flow path sealing portion, thereby minimizing malfunctions due to adsorption of abrasion particles of the valve body. I can do it.

Therefore, even if the valve is used for a long time, the switching speed remains constant and there are no malfunctions, so safety and reliability are improved, and the life of the valve can be extended.

Furthermore, since the rings 26a and 26b are provided on the detent collar 22, the detent mechanism 13 can not only be easily attached to an existing valve body, but also can be adapted to valve bodies with different stroke lengths depending on the spacing between the grooves 25a and 25b. Therefore, processing is easier than when attaching the ring directly to the valve body 12.

Although not shown, rings are attached to the detent collars provided at both ends of the valve body, and the outer peripheral surface of one of these rings is attached to the valve body at both switching positions of the valve body. Two holders facing each other may be provided.

In the above embodiment, the spool-shaped valve body 12 is slid by pilot fluid pressure, but the valve body can be slid by other driving force such as mechanical operating force. The valve body can also be poppet-shaped.

Furthermore, it goes without saying that the directional switching valve is not limited to a 5-port valve.

[Effects of the invention] The detent mechanism of the present invention holds the valve body by the magnetic force between the radially opposed ring and the holding body, and since the detent mechanism does not have a press-contact part, the responsiveness due to wear of the press-contact part is reduced. Not only can a decrease in performance and malfunction be prevented, but also wear of the detent mechanism due to a collision can be prevented.

Therefore, malfunctions due to abrasion particles do not occur, and reliability and safety are improved, and the life of the valve can be extended.

Further, a pair of rings may be provided on the valve body at intervals between the strokes of the valve body, or a pair of rings may be provided at both ends of the valve body, and either of these rings may be provided on the valve body at both switching positions of the valve body. Since the holding body is provided opposite to one side, the valve body can be held in both switching positions.

Furthermore, since the ring is provided on the non-magnetic detent collar, it can not only be easily attached to an existing valve body, but also adaptable to valve bodies with different stroke lengths.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional front view of an embodiment of the present invention, Fig. 2 is an exploded perspective view of the main parts, Fig. 3 is an assembled perspective view of the main parts with a part cut away, and Fig. 4 is a diagram of a known day tent mechanism. FIG. 11... Valve body, 12... Valve body, 13... Daytent mechanism, 22... Daytent collar, 26
a, 26b...ring, 29...holding body, P,
A, B, EA, EB...Port.

Claims (1)

[Claims for Utility Model Registration] 1. A directional control valve comprising a valve body having a plurality of ports, a valve element that switches the flow path between the ports, and a detent mechanism that maintains the flow path switching position of the valve element. The detent mechanism includes a ring attached to the outer peripheral surface of one end of the valve body, and a holder attached to the valve body and facing the outer peripheral surface of the ring at the flow path switching position of the valve body, A detent mechanism for a directional valve, characterized in that one of the ring and the holding body is made of a magnetic material, and the other is made of a permanent magnet. 2. The detent mechanism for a directional control valve according to claim 1, characterized in that a pair of rings are installed with a stroke interval of the valve body. 3. The valve body according to claim 1, further comprising rings attached to both ends of the valve body, and two holders facing either of these rings at both switching positions of the valve body. Day tent mechanism for directional valve. 4. The detent mechanism for a directional control valve according to claim 1, 2 or 3, wherein the ring is attached to the outer peripheral surface of a detent collar made of a non-magnetic material attached to the valve body.