JPH0636376Y2 - Pilot solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a pilot solenoid valve having a good seal structure at the joint surface between the main valve portion and the pilot valve portion.

[Prior Art] The conventional pilot solenoid valve of this type and its problems will be described with reference to FIG. FIG. 6 shows an example of a conventional 5-port pilot solenoid valve, and FIG. 7 shows an example of a seal structure between the main valve portion and the pilot valve portion.
In the drawings, 1 is a main valve portion, 2 is a pilot valve portion, and the pilot valve portion 2 drives the spool 3 to switch the fluid passage of the main valve portion 1. A base 8 having an input port 5 and first and second output ports 6a and 6b, and first and second exhaust ports 7a and 7b is connected to the valve body 4 of the main valve portion 1. Each port 5, 6a, 6
b, 7a and 7b are communicated with the main valve chamber 9. A spool 3 fitted with an elastic ring 10 is axially slidably fitted in the main valve chamber 9, and an end plate 11 forms a return pressure chamber 12 at one end of the main valve chamber 9. This return pressure chamber
12 is communicated with the input port 5 via a return pressure supply passage 13. A spring 14 that constantly presses the spool 3 is provided between the end plate 11 and the spool 3. Further, a piston 15 having a diameter larger than the inner diameter of the return pressure chamber 12 is slidably fitted into the piston sliding chamber 16 in the pilot valve body 2a at the other end of the spool 3. One side of the piston sliding chamber 16 communicates with the pilot output passage 17 and the other side communicates with the pilot exhaust passage 18.

Inside the pilot valve body 2a, a first valve seat 19 and a second valve seat 20 are axially arranged with their backs facing each other. The pilot supply path 21 communicating therewith is open. The first valve body 22 that closes the first valve seat 19 is provided at the end of the plunger 25 that slides against the spring 24 by energizing the coil 23 in the solenoid portion 2b of the pilot valve portion 2. ing. That is, by turning the coil 23 on and off, the first valve body 22 opens and closes the first valve seat 19, and the piston sliding chamber 16 passes through the pilot output passage 17
The inflow and stop of the fluid flowing to The pilot exhaust passage 18 is communicated with the second valve seat 20, and a spring 28 is contracted between the second valve body 26 and the spring pressing member 27. The spring 28 causes the second valve body 26 to move to the second valve seat. It is constantly pressed in 20 directions. The second valve body 26 includes a connecting rod 29 inserted into the pilot output passage 17 formed around the first valve seat 19 and the second valve seat 20 in the pilot valve portion 2, and the tip of the connecting rod 29 is Contacting plunger 25. When the plunger 25 returns to the original position by the spring 24, the second valve body 26 separates from the second valve seat 20 against the spring 28, and when the plunger 25 is attracted to the fixed iron core 30, the second valve The body 26 is configured so that the elasticity of the spring 28 presses and closes the second valve seat 20.

In the normal non-energized state, the plunger 25 is pressed to the left side of the drawing by the elasticity of the spring 24, and the first valve seat 19 is connected to the first valve body 22.
Is closed by. In addition, the second valve body 26 is a connecting rod 29.
The second valve seat 20 is opened by being pushed by the spring 28 so as to resist the elastic force of the spring 28 and away from the second valve seat 20. In this state, the pressure fluid such as air in the piston sliding chamber 16 is opened to the atmosphere through the pilot exhaust passage 18, and the piston sliding chamber 16 is also in communication with the atmosphere. Further, the pressure air flowing in from the input port 5 is guided to the return pressure chamber 12 through the return pressure supply passage 13, pushes the spool 3 to the right side in the drawing, and the spool 3 moves in the same direction. Therefore, the fluid flow path of the main valve portion 1 is from the input port 5 to the second output port 6b,
The output port 6a is switched to the first exhaust port 7a.

Next, when the coil 23 is energized, the plunger 25 is attracted to the fixed iron core 30 against the elasticity of the spring 24. And spring 28
Due to the resilience, the connecting rod 29 and the second valve body 26 move together to open the first valve seat 19 and close the second valve seat 20. In this state, the pressure fluid from the input port 5 receives the first valve seat 19
Pilot output path that passes through the connecting rod 29
It flows into the piston sliding chamber 16 via 17. At this time, the fluid flowing in from the input port 5 enters the return pressure chamber 12 through the return pressure supply passage 13 and acts so as to move the spool 3 to the right side in the drawing, but the diameter of the piston 15 is large. , The spool 3 moves to the left side of the drawing due to the thrust difference,
The fluid flow path of the main valve portion 1 is switched from the input port 5 to the first output port 6a and from the second output port 6b to the second exhaust port 7b.

Now, the joint surface S between the main valve portion 1 and the pilot valve portion 2 needs to be sealed around the piston sliding chamber 16, the pilot supply passage 21 and the pilot exhaust passage 18 so that the pressure fluid does not leak. FIG. 7A shows an enlarged cross-sectional view of a conventional joint surface S portion, FIG. 7B shows a joint surface on the main valve portion 1 side, and FIG. 7C shows a joint surface on the pilot valve portion 2 side. In this case, the piston sliding chamber 16, the pilot supply passage 21, and the pilot exhaust passage are respectively provided on the joint surface on the pilot valve 2 side.
An annular packing groove 31a, 31b, 31c is provided so as to surround 18 and each packing groove 31 is individually packed with a packing 32a, 32b, 32c.
Is fitted. In FIG. 7, 33 is a female screw hole into which the connecting bolt is screwed, and 34 is a through hole for passing the connecting bolt.

In this example, since the packing groove 31 is individually provided around the piston sliding chamber 16, the pilot supply passage 21 and the pilot exhaust passage 18, it is necessary to increase the thickness of the joint surface on the pilot valve 2 side. There is. In the case of a relatively large pilot solenoid valve, there is no problem as in the past, but if the pilot solenoid valve is downsized, the inner diameter of the piston sliding chamber 16, that is, the diameter of the piston 15 must be reduced. The pressure receiving area is reduced, and as a result, there arises a problem that the performance such as the minimum operating pressure, the operating pressure range, the maximum operating frequency, the response time, and the effective area is remarkably reduced.

In order to improve this problem, as shown in FIG.
As shown in (b) and (c), a method using an integral packing has been proposed. In this case, the piston sliding chamber 16 and the pilot supply passage 2 are attached to the joint surface on the pilot valve 2 side.
1. Surrounding the pilot exhaust passage 18 with one continuous packing groove 31, a ninth shape having a shape adapted to this packing groove 31.
An integral packing 32 as shown in the figure is fitted. When such integral packing 32 is used, the thickness of the pilot valve portion 2 side can be made smaller than that in the case of FIG. 7, so that the performance deterioration in the case of miniaturization can be considerably improved. However, recently, further miniaturization of the pilot solenoid valve has been required, so that even if the integral packing as shown in FIGS. 8 and 9 is used, it is unavoidable that the performance is deteriorated.

[Object of the Invention] In order to improve such a conventional problem, an object of the present invention is to make the pressure receiving area of the piston that drives the spool as large as possible even when the pilot solenoid valve is made extremely small. It is to provide a small and high-performance pilot solenoid valve.

[Summary of the Invention] The gist of the present invention for achieving the above object is to provide an inner diameter of a piston sliding chamber of the pilot valve portion at an end surface of the main valve portion at a joint portion between the main valve portion and the pilot valve portion. An annular protrusion having an outer diameter slightly smaller than that of the piston, and the annular protrusion is fitted into the opening of the piston sliding chamber, and the piston sliding chamber, the pilot supply passage and A packing groove is provided so as to surround the pilot exhaust passage so as to fit the integrated packing, and an inner diameter side of a portion of the packing groove that surrounds the piston sliding chamber is opened to the piston sliding chamber. The inner diameter side of the piston sliding chamber seal portion of the integrated packing fitted in the groove is held by the outer peripheral surface of the annular protrusion, and the inner diameter of the piston sliding chamber seal portion and the inner diameter of the piston sliding chamber are Ho This is a pilot solenoid valve that is characterized by making them almost equal.

[Embodiment of the Invention] The present invention will be described in detail based on the embodiment shown in FIGS. 1 to 5.

FIG. 1 shows a joint portion between a main valve portion 1 and a pilot valve portion 2 of a pilot solenoid valve according to the present invention, and FIG. 2 shows A of FIG.
3 is a cross-sectional view taken along the line A, FIG. 3 shows the joint surface on the pilot valve portion 2 side, and the same reference numerals as those shown in the drawings after FIG. 6 represent the same or equivalent members.

In the case of the present embodiment, an annular protrusion 40 having an outer diameter slightly smaller than the inner diameter of the piston sliding chamber 16 on the pilot valve portion 2 side is provided on the joint surface of the main valve portion 1. 40
The main valve portion 1 and the pilot valve portion 2 are connected to each other in a state in which the piston is partially inserted into the piston sliding chamber 16. Further, of the packing groove 41 that surrounds the piston sliding chamber 16, the pilot supply passage 21, and the pilot exhaust passage 18, and into which the integrated packing is fitted, a portion 41b that surrounds the pilot supply passage 21.
The portion 41c surrounding the pilot exhaust passage 18 forms a complete concave groove, but the portion 41a surrounding the piston sliding chamber 16 is not a complete concave groove, and the inner diameter side of the concave groove is open to the piston sliding chamber 16. Has been done. Further, in a portion 41a surrounding the sliding chamber 16 of the piston, an appropriate number of packing locking recesses 4 protruding outward are provided.
Two are provided.

4 and 5 show the integral packing 43 fitted in the packing groove 41, which seals the piston sliding chamber seal portion 43a that seals around the piston sliding chamber 16 and the pilot supply passage 21. A portion 43b for sealing and a portion 43c for sealing around the pilot exhaust passage 18 are integrally formed, and the piston sliding chamber seal portion 43a has a locking convex portion fitted in the packing locking concave portion 42. 43d is projected.

After fitting the integral packing 43 into the packing groove 41 and fitting the annular protrusion 40 on the main valve portion 1 side into the piston sliding chamber 16, the piston sliding chamber sealing portion of the integrated packing 43 is obtained.
The inner side of 43a is held by the annular protrusion 40, and the integral packing 43 is stably fixed. Recess 42 for packing locking
The locking convex portion 43d is for preventing the piston sliding chamber seal portion 43a of the integral packing 43 from protruding inward when the annular protrusion 40 is fitted, and its shape is appropriate. Can be selected.

With such a configuration, the piston sliding chamber of the packing groove 41
Even if the portion 41a surrounding the 16 is not a complete groove, the piston sliding chamber seal portion 43a fitted in this portion can be stably fixed by the annular protrusion 40 on the main valve portion 1 side. it can. Therefore, the inner diameter D of the piston sliding chamber 16 can be made substantially the same as the inner diameter d of the piston sliding chamber sealing portion of the integral packing 43, so that the piston sliding chamber 16 can be made smaller than in the conventional example shown in FIG. The inner diameter D can be increased, and the pressure receiving area of the piston 15 sliding in the piston sliding chamber 16 can be increased.

[Effects of the Invention] As described above, the pilot solenoid valve according to the present invention is
Since the pressure receiving area of the piston on the pilot valve side that drives the spool of the main valve section can be increased,
Even in the case of miniaturization, performance such as minimum operating pressure, operating pressure range, response time, etc. is not significantly deteriorated, and a miniature high-performance pilot solenoid valve can be realized.
In addition, at the joint surface between the main valve portion and the pilot valve portion, the annular protrusion provided on the main valve portion side is fitted into the piston sliding chamber on the pilot valve portion side, so positioning at the time of joining them is easy. It becomes easier and the workability of the assembling process can be improved.

[Brief description of drawings]

1 to 5 show an embodiment of a pilot solenoid valve according to the present invention. FIG. 1 is a sectional view of a joint portion between a main valve portion and a pilot valve portion of a pilot solenoid valve, and FIG. 1 A
-A sectional view taken along the line A, Fig. 3 is an end view of the joint surface on the pilot valve side, Fig. 4 is a front view of the integrated packing, Fig. 5 is a side view, and Fig. 6 is a conventional pilot. Cross-sectional views of the solenoid valve, FIG. 7 and FIG. 8 are joints between the main valve portion and the pilot valve portion of a conventional pilot solenoid valve, (a) is a sectional view of the joint portion, and (b) is the main portion. End view of the valve side,
(C) is a front view of the joint surface on the pilot valve side, and FIG. 9 is a front view of a conventional integrated packing. Reference numeral 1 is a main valve portion, 2 is a pilot valve portion, 3 is a spool,
4 is a valve body, 9 is a main valve chamber, 15 is a piston, 16 is a piston sliding chamber, 18 is a pilot exhaust passage, 21 is a pilot supply passage, 40 is an annular protrusion, 41 is a packing groove, 41a is a piston slide. A part surrounding the chamber, 42 is a packing locking recess, 43 is an integral packing, 43a is a piston sliding chamber seal part, and 43d is a locking projection.

Claims (1)

[Scope of utility model registration request] 1. An annular projecting portion having an outer diameter slightly smaller than an inner diameter of a piston sliding chamber of the pilot valve portion is provided at an end surface of the main valve portion at a joint portion between the main valve portion and the pilot valve portion. , The annular projection is fitted into the opening of the piston sliding chamber, and an integral packing is fitted to the end surface of the pilot valve portion so as to surround the piston sliding chamber, the pilot supply passage and the pilot exhaust passage. Is provided with a packing groove for opening, and the inner diameter side of a portion of the packing groove surrounding the piston sliding chamber is opened to the piston sliding chamber, and the piston sliding chamber of the integrated packing fitted in the packing groove A pilot solenoid valve characterized in that the inner diameter side of the seal portion is held by the outer peripheral surface of the annular protruding portion, and the inner diameter of the piston sliding chamber seal portion and the inner diameter of the piston sliding chamber are made substantially equal.