JP2912867B2 - Mechanical valve of spool valve type - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spool valve type mechanically operated valve in which a fluid flow path is switched by mechanically operating an end of a spool.

[0002]

2. Description of the Related Art Conventionally, a mechanically operated valve has been known as one type of valve used for switching a fluid flow path in a vacuum circuit or the like. Further, such a mechanical operation valve can be roughly classified into a poppet valve type and a spool valve type.

[0003] In a poppet valve type mechanically operated valve, a rod is reciprocated along its axial direction by an external mechanical operation such as pressing a protruding end of a rod connected to a poppet valve portion. ing. As a result, the poppet valve portion comes into contact with or separates from the valve seat provided in the valve main body, so that the fluid flow path is switched.

On the other hand, a mechanical valve of a spool valve type is configured such that the spool reciprocates along its axial direction by an external mechanical operation such as pressing a projecting end of the spool. As a result, the packing slides on or separates from the inner wall surface of the spool chamber, whereby the fluid flow path is switched.

[0005]

By the way, since a rubber packing is fitted on the peripheral surface of the spool, when the spool is in sliding contact, a suitable space is provided between the packing and the inner wall surface of the spool chamber. Sliding resistance acts. Therefore, in the spool valve type, the position of the spool can be held without continuously applying an external force by a mechanical operation. on the other hand,
In the poppet valve type, such a self-holding function does not work in terms of configuration. This is because in this type having no structure corresponding to the packing, no large sliding resistance acts between the valve body and the rod in the first place. Therefore, in this type, an external force must be continuously applied to maintain the position of the rod. Therefore, comparing these points, it is concluded that the spool valve type is superior.

[0006] However, the spool valve type has the following disadvantages. First, unless a large spool stroke (moving distance) is set, the maximum flow rate cannot be obtained. For this reason, compared to the poppet valve type,
Responsiveness is low and the whole is likely to be large. Also,
As the stroke increases, the operating speed of the spool must be increased, and durability is likely to be impaired.

Second, some stopper is required to determine the moving position of the spool, which results in higher cost and lower reliability. The present invention has been made to solve the above problems, and an object of the present invention is to provide a spool valve type mechanically operated valve having both advantages of a spool valve type and a poppet valve type.

[0008]

According to the first aspect of the present invention, a spool is provided in a spool chamber formed inside a valve body so that the spool can reciprocate along its axial direction. A spool valve type mechanically operated valve that is accommodated and that switches the fluid flow path by mechanically operating the end of the spool is provided with a valve seat that also functions as a stopper in the spool chamber. The spool is provided with a poppet valve portion that can be abutted and non-slidable against the spool, and the spool is pressed in a specific direction along an axis thereof by a pressing force based on a differential pressure of a fluid in the valve body. A valve seat and the poppet valve portion are configured to be kept in contact with each other .
Form a ston and apply pressure on both sides of the piston.
Partitioning the space for use, inside one of the pressure acting spaces
The fluid at
Generating a differential pressure to press the spool.
The summary of the

According to a second aspect of the present invention, the spool is accommodated in a spool chamber formed inside the valve body so as to be reciprocally movable along the axial direction, and the end of the spool is mechanically operated. The first and second valve seats, which also function as stoppers, are provided opposite to each other in the spool chamber, and can be brought into contact with each of the valve seats. The first valve seat and the poppet valve are provided by providing a non-slidable poppet valve portion on the spool and pressing the spool in a specific direction along an axis thereof by a differential pressure of fluid in the valve body. And the second valve seat and the poppet valve portion are held apart from each other, and the urging force of the spool urging means moves the spool in the opposite direction to the specific direction. It is the pressure, it is configured such that the second valve seat and said poppet valve portion abutting state is held and the first valve seat and the poppet valve is held in the separated state, the spool Form a piston in part of
With the pressure working space on both sides of the piston,
Vacuum the fluid inside one of the pressure action spaces
Pressing the spool by discharging by pulling
The main point is to generate a differential pressure for performing the operation.

[0010]

[0011] The invention described in claim 3 is the invention according to claim 1 or
2, among the plurality of ports provided in the valve body, the first valve seat and the poppet valve portion are in an abutting state, and the second valve seat and the poppet valve portion are in a separated state. The gist is that the port to be evacuated when the pressure is reduced and the pressure action space to be evacuated are connected via a fluid discharge communication passage.

The "action" of the present invention will be described below. According to the first aspect of the present invention, when the poppet valve portion is in contact with the valve seat, the fluid flow path is closed, and when the poppet valve portion is separated from the valve seat, the fluid flow path is closed. Is opened. As a result, switching of the fluid flow path is performed,
The direction of the fluid flowing in the valve body is changed. Further, according to the present invention, the following operation is further obtained.

I) The movement of the spool is restricted by the poppet valve portion coming into contact with the valve seat also serving as the stopper. Therefore, there is no need to separately provide a stopper for determining the moving position of the spool, and cost reduction and improvement in reliability are achieved.

Ii) Since the poppet valve portion which cannot slide on the valve seat is provided, the spool stroke can be reduced by the amount corresponding to the distance of sliding between the two. Therefore,
The setting of the spool stroke for obtaining the maximum flow rate can be made smaller than that of a general spool valve type. As a result, the response of the spool is increased, and the overall size is reduced. In addition, as a result of reducing the stroke, it is not necessary to increase the operating speed of the spool, and the durability is improved.

Iii) When the spool is pressed by the pressing force based on the differential pressure of the fluid, the valve seat and the poppet valve portion are held in contact with each other. As a result of such a self-holding function, the position of the spool can be held at a predetermined position without continuously applying an external force by a mechanical operation.

According to the second aspect of the present invention, when the poppet valve portion is in contact with the first valve seat, the fluid flow path is closed, while the poppet valve portion is in contact with the second valve seat. When separated, the fluid flow path is opened. In this case, the fluid will flow to the open second valve seat side. The fluid flow path is opened when the poppet valve portion is separated from the first valve seat, while the fluid flow channel is closed when the poppet valve portion is in contact with the second valve seat. in this case,
The fluid will flow to the open first valve seat side. Thus, the switching of the fluid flow path is performed, and the direction of the fluid flowing in the valve body is changed. According to the present invention, in addition to the effects of the above-mentioned i) to iii), the following effects are exhibited.

That is, the spool is pressed by the urging force of the spool urging means, whereby the position of the spool is self-held. That is, self-holding is achieved not in one direction but in two directions.

According to the invention described in claim 1 or 2 ,
The pressures in the two pressure action spaces defined via the pistons become unbalanced, and the pistons are pressed toward the pressure action spaces that have become relatively low in pressure by evacuation.

According to the third aspect of the present invention, in the predetermined switching state, the fluid in the pressure action space is discharged to the outside through the fluid discharge communication passage, and the fluid pressure in the space decreases. Therefore, the piston is pressed toward the space.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a spool valve type mechanically operated valve for a vacuum circuit will be described in detail with reference to FIGS.

As shown in FIGS. 2 and 3, a body 2 as a valve main body constituting the mechanical operation valve 1 is a square cylindrical member made of an aluminum alloy. The interior of the body 2 is divided into three regions, that is, a large-diameter portion 2a, a small-diameter portion 2b, and a medium-diameter portion 2c in order from the first end surface (the left end surface in FIG. 2) of the body 2. The right opening edge of the small diameter portion 2b functions as a first valve seat B1 in the present embodiment.

A first cap 3 made of an aluminum alloy is non-slidably fitted to the first end face. The cap 3 includes a bush mounting portion 3a, a flange portion 3b, and a cylindrical fitting portion 3c. The flange portion 3b is fixed to the first end surface by a pan-head screw 7 having a cross-shaped hole. The cylindrical fitting portion 3c protrudes from the inner surface of the flange portion 3b. An annular groove is provided on the outer peripheral surface of the cylindrical fitting portion 3c, and an O-ring 4 is mounted therein. As a result, sealing at the interface between the inner wall surface of the large diameter portion 2a of the body 2 and the outer peripheral surface of the cylindrical fitting portion 3c is achieved. The bush mounting portion 3a is provided so as to protrude from the center of the outer surface of the flange portion 3b. A bush 5 having a through hole at the center is fitted in the bush mounting portion 3a. A spool S is provided at the center of the first cap 3.
Spool insertion hole 6 for inserting the member constituting 1
Are formed.

On the other hand, a second end face of the body 2 (FIG. 2)
A second cap 10 made of an aluminum alloy is non-slidably fitted to the right end face of the second cap. This cap 10
Has a bush mounting portion 10a, a flange portion 10b, and a cylindrical fitting portion 10c. The flange portion 10b is
Is fixed to the end face by a pan-head screw 7 having a cross hole. The cylindrical fitting portion 10c protrudes from the inner surface of the flange portion 10b. The cylindrical fitting portion 10c has a smaller diameter and a longer length than the cylindrical fitting portion 3c. Two annular grooves are provided on the outer peripheral surface of the cylindrical fitting portion 10c, and O-rings 11 and 12 are provided therein.
Is installed. As a result, sealing at the interface between the inner wall surface of the middle diameter portion 2c of the body 2 and the outer peripheral surface of the cylindrical fitting portion 10c is achieved. The bush mounting portion 10a is provided so as to protrude from the center of the outer surface of the flange portion 10b. The bush 5 is fitted in the bush mounting portion 10a. A spool insertion hole 6 is formed in the center of the second cap 10. The distal end portion of the cylindrical fitting portion 10c functions as a second valve seat B2 in the present embodiment. The above-mentioned first valve seat B1 and second valve seat B2
Are opposed to each other at a predetermined interval. Each of these valve seats B1 and B2 also has a function as a stopper.

Then, as described above, both caps 3, 10
By closing both end surfaces of the body 2, a spool chamber for accommodating the spool S 1 is defined inside the mechanical operation valve 1.

As shown in FIGS. 1 (a), 1 (c), 2 and 3, on the lower surface of the body 2, an A port 13 connected to a vacuum pad and a vacuum A V port 14 connected to the pump is formed adjacently. O-rings 15 are attached to the openings of these ports 13 and 14, respectively. As shown in FIGS. 2 and 3, an R port 16 that is open to the atmosphere is formed on the front and back surfaces of the body 2.

The A port 13 and the spool chamber communicate with each other via a first communication passage 17 penetrated through the middle diameter portion 2c of the body 2. The V port 14 and the spool chamber are communicated with each other via a second communication passage 18 provided at a position closer to the right end face than the communication passage 17. The second communication path 18 is formed by two O-rings 11, 1 attached to the cylindrical fitting portion 10c of the second cap 10.
It is located between the two. At a position corresponding to the second communication hole 18 in the cylindrical fitting portion 10c, a through hole 19 communicating the inside and the outside of the cylindrical fitting portion 10c is provided.

On the upper surface and the lower surface of the body 2, two fixing holes 20 used for fixing the mechanical operation valve 1 to the support are formed. As shown in FIGS. 2 and 3, a spool S1 is housed in a spool chamber inside the mechanical operation valve 1 so as to be able to reciprocate along its axial direction. Spool S of the present embodiment
1 is, roughly speaking, three members: a poppet valve 2
1, the first shaft 22 and the second shaft 23 are assembled together.

The poppet valve portion 21 has a sleeve 24 made of an aluminum alloy and a rubber lining portion 2 formed so as to cover a flange portion in the middle of the sleeve 24.
5 The rubber lining portion 25 is disposed between the valve seats B1 and B2 provided opposite to each other, and has a side surface tapered. At a position on the left side of the rubber lining portion 25 in the sleeve 24, a through hole 26 communicating between the inside and the outside of the sleeve 24 is formed. A female screw groove for screwing the first shaft 22 is formed on the inner peripheral surface of the left end opening of the sleeve 24.

The second shaft 22 is made of stainless steel, and includes a shaft portion 27 and a large-diameter portion 28 provided in the middle of the shaft portion 27. A rubber packing 29 is mounted in an annular recess provided on the outer peripheral surface of the large diameter portion 28. While the large diameter portion 28 slides on the inner wall surface of the cylindrical fitting portion 10c, the shaft portion 27 does not slide on the same surface. In addition, both 10c,
The interface where 28 slides is sealed.

The left end of the second shaft 23 is swaged against the right opening of the sleeve 24. Therefore, the second shaft 23 and the poppet valve portion 21 are integrated. The right end of the second shaft 23 projects outside the body 2 via the spool insertion hole 6 and the bush 5 of the second cap 10.

The first shaft 22 is made of stainless steel, and is formed with a shaft portion 31, a piston 32 provided on the inner end side of the shaft portion 31, and a central portion of the piston 32 along the axial direction. And a mounting hole 33. Piston 32
A rubber packing 34 is mounted in an annular concave portion provided on the outer peripheral surface of the rubber member. The packing 34 seals between the outer peripheral surface of the piston 32 and the inner wall surface of the large diameter portion 2a of the body 2. A female screw groove is formed on the inner wall surface of the mounting hole 33. A hexagon socket set screw 35 is screwed into the mounting hole 33 and the left opening of the sleeve 24. Therefore, the first shaft 22 and the poppet valve portion 21 are integrated. The left end of the first shaft 22 projects outside the body 2 via the spool insertion hole 6 of the first cap 3 and the bush 5.

The spool S1 assembled as described above
Is accommodated, the rubber lining portion 25 includes a pair of valve seats B.
1 and B2. As shown in FIGS. 2 and 3, the rubber lining portion 25 is provided with respective valve seats B1,
B2 can be contacted and cannot slide. The piston 32 accommodated in the large diameter portion 2a of the body 2
Defines a first pressure action space R1 and a second pressure action space R1 on both sides thereof. The first pressure action space R1 exists on the left end face side of the piston 32, and the second pressure action space R1
2 exists on the right end face side of the piston 32. In the first pressure action space R1, an O-ring 36, a spacer 37 and a coil spring 38 as a piston urging means are accommodated. The coil spring 38 always presses the piston 32 rightward.

First communication path 17 connected to A port 13
And the first pressure action space R1 are connected to each other via a fluid discharge communication passage 39 provided in the body 2. Therefore, air as a fluid in the first pressure action space R1 is evacuated through the fluid discharge communication passage 39 in a predetermined case.

As shown in FIGS. 2 and 3, machine operating portions M1 and M2 using a cam mechanism, for example, are attached to both end surfaces of the machine operating valve 1, respectively. Then, by operating one of the machine operation units M1 and M2, one end of the spool S1 is pushed into the body 2. As a result, the air flow path can be switched.

Next, the operation of the mechanical control valve 1 configured as described above will be described. When an operating force is applied from the left end face of the spool S1 by operating only the first machine operation unit M1, the spool S1 moves to the rightmost position as shown in FIG. Then, the first valve seat B1 and the rubber lining portion 25 are separated from each other, and the second valve seat B2 and the rubber lining portion 25 are in contact with each other. therefore,
The A port 13 is not connected to the V port 14 and is connected only to the R port 16. That is, the A port 13 is open to the atmosphere, and the vacuum pad connected to the A port 13 does not perform vacuum suction. Therefore, at this time, the vacuum pad releases the work.

In this case, the air pressure in the first pressure action space R1 and the air pressure in the second pressure action space R2 are equal to the atmospheric pressure. Therefore, the pressing force due to the differential pressure does not act on the piston 32, and only the urging force of the coil spring 38 acts. As a result, even after the operation force is removed, the first valve seat B1 and the rubber lining portion 25 are kept separated from each other, and the second valve seat B2 and the rubber lining portion 25 are kept in contact with each other. Is done. That is, self-holding of the spool S1 at the right end of the stroke is achieved. In this case,
The second valve seat B2 serves as a stopper for restricting further movement of the spool S1 toward the right end of the stroke.

Next, when an operation force is applied from the right end face of the spool S1 by operating only the second machine operation section M2,
As shown in FIG. 2, the spool S1 moves to the leftmost position against the urging force of the coil spring 38. Then, the first valve seat B1 comes into contact with the rubber lining portion 25, and the second valve seat B2 comes into contact with the rubber lining portion 25.
Are separated from each other. Therefore, A port 13
It is not connected to the port 16 and communicates only with the V port 14. That is, the air on the A port 13 side is
The gas is discharged to the outside of the body 2 through the second communication hole 18 and the V port 14. Therefore, the vacuum pad connected to the A port 13 sucks the work in vacuum.

In this case, the air in the first pressure action space R 1 flows through the first communication passage 17 via the fluid discharge communication passage 39.
And finally discharged to the outside of the body 2 through the V port 14. Therefore, the air pressure in the first pressure action space R1 becomes lower than the atmospheric pressure at this time. On the other hand, the air pressure in the second pressure action space R2 is still equal to the atmospheric pressure. Therefore, both the pressing force by the differential pressure and the urging force of the coil spring 38 act on the piston 32. However, the pressing force is set to a value larger than the urging force. Therefore, even after the operation force is removed, the first valve seat B1 and the rubber lining portion 25 are kept in contact with each other, and the second valve seat B2 and the rubber lining portion 25 are kept in a separated state. You. That is, self-holding of the spool S1 at the left end of the stroke is achieved. In this case, the first valve seat B1 serves as a stopper for restricting the further movement of the spool S1 toward the left end of the stroke.

When the operating force is again applied by the machine operating section M1, the first valve seat B1 and the rubber lining section 25 are applied.
Are separated from each other, and air flows in from that part. Then, the air pressure in the first pressure action space R1 increases, and the pressing force acting on the piston 32 also decreases accordingly.

Hereinafter, the characteristic operation and effect of this embodiment will be listed. (A) According to this embodiment, the first and second valve seats B1,
B2 also has a function of a stopper for the spool S1. Therefore, it is not necessary to separately provide such a stopper. Therefore, the structure is simpler than that of a conventional spool valve type mechanically operated valve, and cost reduction and improvement in reliability can be achieved. In addition, since there is no stopper structure in which the metals come into contact with each other, settling of the contact surface and scattering of foreign matter are prevented, and durability is improved.

(B) According to the present embodiment, the spool S1
The rubber lining 25 provided on the poppet valve 21 of
While it is possible to abut against the valve seats B1 and B2, the valve seat B1
, B2. For this reason, the spool stroke can be reduced by an amount corresponding to the elimination of the sliding distance between the poppet valve portion 21 and the inner wall surface of the spool chamber. Therefore, the spool stroke for obtaining the maximum flow rate can be set smaller than that of a general spool valve type. This has the following benefits.

First, the responsiveness of the spool S1 increases. This is because if the spool stroke is small, the spool S1 can be reliably operated even at the same operation speed.

Second, the overall length of the mechanical operation valve 1 can be reduced. When the spool stroke is small, the outer dimensions of the cam are small enough even when operated using a cam mechanism or the like. Therefore, the machine operation units M1 and M2 can be reduced in size.

Third, durability is improved. This is because if the spool stroke is small, the operating speed of the spool S1 does not need to be set to be high. FIG. 4 shows a graph for explaining a difference between characteristics of a general spool valve type and a poppet valve type. As is clear from the graph, the poppet valve type has a higher response to the pressure fluctuation with respect to the displacement of the spool S1 than the spool valve type. Of course, the mechanical operation valve 1 of the present embodiment is called a spool valve type, but it goes without saying that its characteristics are close to those of a poppet valve type.

(C) According to the present embodiment, the spool S1 is pressed by the pressing force based on the differential pressure of air,
The first valve seat B1 and the rubber lining portion 25 are securely held in a contact state. On the other hand, when the spool S1 is pressed by the urging force of the coil spring 38, the second valve seat B2 and the rubber lining portion 25 are reliably held in a contact state. That is, according to this embodiment, self-holding of the position of the spool S1 is achieved in both directions. as a result,
Even if the external force is not continuously applied by the mechanical operation, the spool S
Position 1 can be securely held at the end of the stroke. The self-holding in both directions contributes to further shortening of the entire mechanical operation valve 1.

The present invention can be modified, for example, as follows. (1) The present invention is not limited to the double rod structure as in the above embodiment, but may be applied to a single rod structure.

(2) For example, it is also possible to apply a pressurized air to one end surface of the piston 32 and obtain a piston pressing force by a differential pressure caused by the pressurized air. (3) In the above embodiment, self-holding in both directions is achieved by the pressing force due to the differential pressure of the fluid and the urging force of the piston urging means. Of course, the present invention is not limited to this. For example, it is also possible to achieve bidirectional self-holding by using the pressing force due to the differential pressure of the fluid.

(4) Instead of providing the rubber lining portion 25 on the spool S1 side, a rubber lining portion may be provided on the valve seats B1, B2 side. (5) The number of ports 13, 14, 16 provided in the body 2 may be three or more, or the rubber lining portion 25 may be formed at a plurality of locations.

(6) The piston urging means may be other than the coil spring 38, and for example, a leaf spring or the like can be used. Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below.

(1) The spool valve type according to any one of claims 1 to 4, wherein the spool is constituted by assembling a poppet valve portion having a rubber lining portion on an outer peripheral surface thereof between a pair of shafts. Mechanical control valve.

(2) In the technical idea (1), the poppet valve portion is characterized by comprising a sleeve and a rubber lining portion formed so as to cover a flange portion in the middle of the sleeve. Spool valve type mechanically operated valve.

(3) In the technical concept (2), a side surface of the rubber lining portion is a tapered surface. (4) In the technical ideas (1) to (3), at least one of the shafts includes a shaft portion, a piston provided on an inner end side of the shaft portion, and an axial line at a center portion of the piston. And a threaded mounting hole formed along the direction of the spool.

(5) Claims 2 to 4, Technical idea (1)
In (4), the spool biasing means is a spring that biases the piston by being housed in the pressure action space in which the evacuation is performed. valve.

The technical terms used in the present specification are defined as follows. "Fluid: refers to air (air) and other gases that are nitrogen, oxygen, argon, carbon dioxide, hydrogen, and mixtures thereof, and also includes liquids such as water."

[0055]

As described in detail above, according to the first to third aspects of the present invention, there is provided a mechanical valve of a spool valve type having both advantages of a spool valve type and a poppet valve type. Can be. Specifically, cost reduction, overall size reduction, reliability improvement, durability improvement, and responsiveness improvement can be achieved.

In particular, according to the second aspect of the present invention, bidirectional self-holding can be achieved, so that the overall size can be further reduced.

[Brief description of the drawings]

1A is a plan view of a spool valve type mechanically operated valve according to an embodiment, FIG. 1B is a left side view of the mechanically operated valve, FIG.
(C) is a bottom view of the mechanically operated valve, and (d) is a JIS symbol indicating the mechanically operated valve.

FIG. 2 is a sectional view of the mechanical operation valve.

FIG. 3 is a sectional view of the mechanical operation valve.

FIG. 4 is a graph for explaining a difference in characteristics between a poppet valve type mechanically operated valve and a spool valve type mechanically operated valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spool valve type mechanical operation valve, 2 ... Body as a valve body, 13 ... A port, 14 ... V port, 16 ... R
Port, 21 ... Poppet valve part, 32 ... Piston, 38 ...
Coil spring as a biasing means for the spool, 39... A communication passage for discharging fluid, R1... A first pressure action space where vacuum is to be drawn, R2.
... Spool, B1 ... First valve seat, B2 ... Second valve seat.

Claims (3)

(57) [Claims] A spool (S1) is accommodated in a spool chamber formed inside a valve body (2) so as to be able to reciprocate along its axial direction, and the end of the spool (S1) is mechanically operated. In the spool valve type mechanically operated valve (1) in which the fluid flow path is switched, a valve seat (B1) also serving as a stopper is provided in the spool chamber, and abuts against the valve seat (B1). The poppet valve portion (21) which can be slid and cannot be brought into contact with the spool (S1)
The spool (S1) is pressed in a specific direction along its axis by a pressing force based on a differential pressure of the fluid in the valve body (2), so that the valve seat (B1) and the poppet valve portion are provided. (21) is held in a contact state, and a piston (32) is attached to a part of the spool (S1).
And pressurized on both sides of the piston (32).
Space (R1, R2), and the pressure action space (R
(1, R2) to evacuate the fluid inside one of
The spool (S1).
A spool valve type mechanically operated valve characterized by generating a differential pressure for pressurizing . 2. A spool (S1) is accommodated in a spool chamber formed inside the valve body (2) so as to reciprocate along its axial direction, and an end of the spool (S1) is mechanically operated. The first and second valve seats (B1, B2) serving also as stoppers are provided opposite to each other in the spool chamber in the spool valve type mechanically operated valve (1) in which the fluid flow path is switched by doing so. A poppet valve portion (21) that can contact and cannot slide on each of the valve seats (B1, B2) is provided on the spool (S1), and the spool is driven by a differential pressure of a fluid in the valve body (2). (S
1) is pressed in a specific direction along its axis, whereby the first valve seat (B1) and the poppet valve portion (21) are held in contact with each other and the second valve seat (B2) is pressed. ) And the poppet valve portion (21) are held apart from each other, and the spool (S1) is pressed in the opposite direction to the specific direction by the urging force of the spool urging means (38).
The second valve seat (B2) and the poppet valve portion (21) are held in contact with each other, and the first valve seat (B1) and the poppet valve portion (21) are held in a separated state. And a piston is provided on a part of the spool (S1).
(32) and both of its pistons (32)
The pressure action space (R1, R2) is defined on the side
Fluid in one of the working spaces (R1, R2)
By discharging by vacuuming, the spool
(S1) is characterized by generating a differential pressure for pressing
And the spool valve type of machine operation valve. 3. A plurality of valve bodies provided in the valve body (2).
The first valve seat among the ports (13, 14, 16);
(B1) is in contact with the poppet valve (21)
The second valve seat (B2) and the poppet valve portion (21)
Port that is evacuated when separated from
(13) and the pressure acting air in which the evacuation is performed.
The space (R1) is connected via the fluid discharge communication passage (39).
The method according to claim 1, wherein the connection is continued.
Mechanical valve of spool valve type.