JP3059612B2 - Slide 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 slide valve, and more particularly to a slide valve capable of increasing the switching speed and reducing the size.

[0002]

2. Description of the Related Art A slide valve for switching a load includes, for example, a valve seat 103 which covers a lower surface of an inverted U-shaped groove-shaped valve chamber formed in a valve box 101, as shown in a vertical side view of FIG. A spool 104 slidably inserted into the valve chamber 102, and a valve body 105 driven by the spool 104 to slide along the upper surface of the valve seat 103.

[0003] The valve seat 103 has an inlet port 106 formed on the upper surface thereof and opened in the sliding direction of the valve body 105.
Outlet port 1 for two load connections that are alternatively connected to
It has two exhaust ports 108A and 108B corresponding to the outlet ports 107A and 107B. In addition, an outlet port 107 is provided on the lower surface of the valve body 105, respectively.
A and 107B are connected to inlet port 106 and corresponding exhaust port 108
Two passages 109A and 10 for switching connection to A and 108B
9B are recessed side by side in the sliding direction of the valve body 105 (hereinafter simply referred to as sliding direction).

As shown in FIGS. 8 to 10, the valve body 105 is driven by a spool 104 and slid, so that a lower surface of a central portion between both passages 109A and 109B of the valve body 105 is provided.
By superimposing 110A on portions 111A and 111B of the sliding surface 111 on either side of the sliding direction of the inlet port 106 of the valve seat 103, one of the outlet ports 107A (or 107
B) is blocked from the inlet port 106 and the passage 109
Exhaust port 108B via B (or 109A)
(Or 108A) and the other outlet port 1
07A (or 107B) through 109A entrance port
It communicates with 106.

The exhaust port 108A (or 108B) corresponding to the outlet port 107A (or 107B) which is in communication with the inlet port 106 by the valve body 105 has outlet ports corresponding to both ends in the sliding direction of the valve body 105. 107A (or 107A
B) and the inlet port 106. As the driving method of the spool 109, various methods such as manual driving, electric driving, pneumatic driving, and hydraulic driving are employed. In particular, when switching of the valve at a high speed is required, the valve seat 107 and the valve element 108 are often made of ceramics having excellent wear resistance.

In the conventional slide valve, when the pressure control of each of the outlet ports 107A and 107B and each of the load circuits connected thereto is strict, for example, as shown in a schematic diagram of FIG. During the transition period,
110A covers inlet port 106, both outlet ports 107A
107B is simultaneously shut off from the inlet port 106, and both outlet ports 107A and 107B are also shut off from the corresponding exhaust ports 108A and 108B.

A valve 105 and a valve seat 10 are provided between the ports.
In order to secure the sealing property between the first and second members, a length longer than a certain length a in the sliding direction is required. The cross-sectional area of the flow passage of each port is determined by the required flow rate of the working fluid such as compressed air and the dimension in the direction perpendicular to the sliding direction of each port (hereinafter referred to as the width direction). The dimension in the width direction is limited to a certain value or less corresponding to the dimension in the width direction of the solenoid valve given by a standard such as ISO.

The length of the valve element 105 in the sliding direction is the length of the central lower surface 110A in the sliding direction, and the length of the passage 109A on both sides thereof.
-Set to the total length of the sliding direction length of 109B, twice the stroke of the valve body 105, and the sealing surfaces 110B and 110C required on both outer sides of both exhaust ports 108A and 108B. Is done. Now, assuming that the length in the sliding direction required by each port to obtain a predetermined flow rate is b,
The length of 110A is set to the length b in the sliding direction of the inlet port 106, and the stroke of the valve seat 105 is set to the length b in the sliding direction of the inlet port 106 to the length b in the sliding direction of the lower surface 110A at the center. b
Is set to the length 2b or more.

The length of each of the passages 109A and 109B in the sliding direction is determined by the distance a between each outlet port 107A and 107B and the corresponding exhaust port 108A and 108B, and the length of the outlet port 107A and 107B. It is necessary to set the length (a + 2b) or more to the sum of the length b in the sliding direction and the length b in the sliding direction of the corresponding exhaust port 109A / 109B. Therefore, the length of the valve element 105 in the sliding direction is the center lower surface 110A.
Of the sliding direction of each and the respective passages 109A
B, the length in the sliding direction (a + 2b), and the length of each sealing surface 110 required outside the passages 109A and 109B.
The total length (4a + 9b), which is twice the length a of B · 110C in the sliding direction, is set to be equal to or longer than (4a + 9b), and the length of the valve seat 103 is the length obtained by adding the stroke 2b of the valve body 105 ( 4a + 11
b) Set as above.

[0010]

When a large flow rate is required in this conventional slide valve, the length b of each port in the sliding direction is required to obtain the required flow rate while complying with standards such as ISO. To increase the size of the slide valve in the sliding direction by increasing the size, accept the lack of flow to avoid the size increase, or ignore standards such as ISO. There is a disadvantage that it must be done.

[0011] Of these, ignoring standards such as ISO impairs the versatility of the product, so it is allowed only in extremely limited cases. Is unfavorably restricted. After all, in normal production, it is often accepted to increase the size. However, as the length of the valve seat 103 and the valve body 105 in the sliding direction increases, the valve body 10
5 is the area in sliding contact with the valve seat 103 (hereinafter referred to as the sliding area)
Increases, and the sliding resistance of the valve body 105 increases.
The switching speed of the valve becomes slow, and the spool 104
It is necessary to increase the force (hereinafter referred to as thrust) for driving the sliding valve 5 in the sliding direction. For this reason, the spool 104 must have a large diameter, and the sliding valve must be large in the direction perpendicular to the sliding direction. Problem arises.

The inventor of the present invention has conducted various studies and experiments, and has found that a point at which a thrust acts on the valve element 105 when a force for driving the valve element 105 in the sliding direction is applied from the spool 104 (hereinafter referred to as a power point). ), A force in the direction of lifting the valve element 105 from the upper surface of the valve seat 103 (hereinafter referred to as a prying force) is generated with the intersection of the opposite end surface and the upper surface of the valve seat 103 as a fulcrum.
When one end of the valve body 105 was lifted from the upper surface of the valve seat by this prying force, it was found that the sliding resistance of the valve body 105 was rapidly reduced and the moving speed of the valve body 105 was increased.

The present inventor has conducted various studies and experiments. As a method of applying a force for starting the movement of the valve body 105, the spool 104 is started after a certain amount of inertial force is generated by starting the spool 104. Colliding against the valve body 105, the force for starting the spool 104 can be reduced, and a force is applied to the valve body 105 in a shocking manner. It has been found that sufficient prying force can be produced.

The present invention has been completed based on these findings, and can increase the switching speed.
It is an object of the present invention to provide a slide valve that can be reduced in size.

[0015]

SUMMARY OF THE INVENTION The present invention provides a valve seat that covers a lower surface of a valve chamber formed in a valve box, a spool that is inserted into the valve chamber so as to be able to advance and retreat, and a valve seat that is driven by the spool to form a valve seat. A valve body that moves along the upper surface, wherein the valve seat is alternatively connected to an inlet port opened on the upper surface, and an inlet port.
It has one load connection outlet port and two exhaust ports corresponding to each outlet port.
To achieve the above object, in a slide valve in which one of two outlet ports is alternatively connected to an inlet port and the other outlet port is connected to a corresponding exhaust port. The following measures have been taken.

That is, an inlet port is opened at a side edge portion of the upper surface of the valve seat, and both outlet ports are opened at the center of the upper surface of the valve seat in a sliding direction. Exhaust ports respectively corresponding to both outer sides of the port in the sliding direction are opened, and the valve body is divided into two in the sliding direction.
An inlet-side passage is formed between the two valve bodies, which selectively connects the valve chamber to one of the two outlet ports, and the lower surface of each valve body is isolated from the valve chamber. An exhaust-side passage for communicating the outlet port with a corresponding exhaust port is formed, and two small-diameter portions into which the respective valve elements are fitted are formed between a center portion and both end portions in the sliding direction of the spool, and each small-diameter portion is formed. Is slightly longer than the length of each valve element in the sliding direction.

[0017]

According to the present invention, the inlet port may be opened at both side edges in the width direction of the valve seat, or may be opened at only one side edge. The working fluid flowing into the chamber flows into one of the outlet ports from the inlet passage formed between the two valve bodies, and the working fluid from the outlet port blocked from the inlet passage is exhaust gas formed in the valve body. It will flow out to the corresponding exhaust port through the side flow path.

Here, at the center of the upper surface of the valve seat in the width direction, four ports, that is, both outlet ports and both exhaust ports, are opened side by side in the sliding direction. In addition, since the length of the valve body and the valve seat in the sliding direction is shorter than that of the conventional example in which the inlet port is opened side by side in the sliding direction, the entire slide valve can be shortened in the sliding direction and downsized. In addition, the sliding area of the valve body is reduced, the sliding resistance of the valve body is reduced, and the switching speed of the valve can be increased.

Also, since the sliding resistance of the valve body is reduced,
The valve body can be driven with a weak thrust, so that the diameter of the spool can be reduced and the slide valve can be reduced in size in a direction perpendicular to the sliding direction. When the thrust is applied from the spool to the valve body, the thrust-opening force is defined as a straight line connecting the fulcrum and the force point to which the force is applied, with the intersection point between the end face opposite to the end face to which the thrust is applied and the upper surface of the valve seat as a fulcrum. This is considered to be a component force of the thrust generated in a direction perpendicular to the direction. Therefore, assuming that the included angle between the straight line and the upper surface of the valve seat is θ and the force applied to the force point is F, the prying force is F × sin θ.

In the present invention, since the valve element is composed of two valve elements divided into two in the sliding direction, the sliding direction of each valve element is smaller than in the conventional example in which the valve elements are integrally formed. Is short, the fulcrum is close to the force point and θ increases, and the prying force for the thrust F of the same magnitude increases. This makes it easier for the end of the valve element on the force point side to float up from the upper surface of the valve seat than the conventional product, and one end of the valve body rises up from the upper surface of the valve seat in a short time after the thrust starts to act on the valve body. Since the sliding resistance of each valve rapidly decreases,
The switching speed of the valve can be increased.

From another point of view, one end of each valve body can be lifted from the upper surface of the valve seat with a smaller thrust than the conventional one, so that the diameter of the spool is reduced and the slide valve is moved in a direction perpendicular to the sliding direction. The size can be further reduced. Also,
In the present invention, two small-diameter portions into which the respective valve bodies are fitted are formed between the center portion and both end portions in the sliding direction of the spool, and the length of each small-diameter portion in the sliding direction is determined by the sliding of each valve body. Since the length is slightly longer than the length in the moving direction, a gap is formed between the end surface of the valve body and the abutting surface of the spool facing the valve body at the stroke end of the spool.

Therefore, when the spool subsequently moves in the reverse direction, the spool may be started with a force ignoring the stationary inertia of the valve body, so that the spool can be started with a weak force. Then, the spool starts to move, and after the inertial force is obtained, the contact surface collides with the end face of the stationary valve body, and a force for prying open is applied to the valve body, so that one end of each valve body is Even if the thrust of the spool is weaker than before, one end of each valve element rises from the slip surface in a short time even if the thrust of the spool is weaker than before, the sliding resistance decreases rapidly and the switching speed of the valve is increased. By making the spool smaller in diameter, the slide valve can be made even smaller in the direction perpendicular to the sliding direction.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a slide valve according to one embodiment of the present invention will be specifically described with reference to the drawings. However, the present invention is not limited to this embodiment, and is not limited to this specification and the accompanying drawings. The present invention extends widely over the true intended scope of the invention as apparent from the drawings.

A slide valve according to an embodiment of the present invention shown in a longitudinal side view of FIG. 1 and an exploded perspective view of FIG. 2 is a ceramic valve which covers the lower surface of an inverted U-shaped valve chamber 2 formed in a valve box 1. And a spool 4 which is inserted into the valve chamber 2 so as to be able to advance and retreat, and two ceramic valve bodies 5A and 5B which are driven by the spool 4 and slide along the upper surface of the valve seat 3. Is provided.

Further, the lower surfaces of the valve seat 3 and the valve box 1 are covered with a valve seat retainer 12 also serving as an interface, and a pipe mounting base 13 is fixed to the lower surface of the valve box 1. On the upper surface 14 of the valve seat 3, inlet ports 6.6 are respectively opened on both side edges in the width direction, and two outlet ports 7A and 7B slide in the center of the upper surface 14 of the valve seat 3. Opened side by side. Exhaust ports 8A and 8B corresponding to the outlet ports 7A and 7B are opened at both sides in the sliding direction of the outlet ports 7A and 7B at the center in the width direction of the upper surface 14 of the valve seat 3.

The spool 4 has a large diameter portion in the axial direction, that is, a center portion and both end portions in the sliding direction, and is provided below the small diameter portions 4A and 4B between these large diameter portions. Each valve element 5A
5B is arranged, and an inlet-side passage 9 which connects the valve chamber 2 to the two outlet ports 7A and 7b alternatively is formed between the two valve bodies 5A and 5B. As shown in the schematic diagrams of FIGS. 3 to 5, the length of the inlet-side passage 9 in the sliding direction is determined by each of the outlet ports 7A and 7B required to secure a required flow rate.
And the same length as the length b in the sliding direction of the exhaust ports 8A and 8B.

As shown in FIG. 4, the interval between the two outlet ports 7A and 7B of the valve seat 3 is such that the two outlet ports 7A and 7B are simultaneously shut off from the inlet side passage 9 in the transition period. In order to do so, the groove width of the entrance side passage 9,
That is, the length b in the sliding direction of each of the outlet ports 7A and 7B.
Is set to the same length as. As shown in FIG. 1 and FIGS. 3 to 5, the lower surfaces of the respective valve elements 5A and 5B have outlet ports 7A and 7 that are cut off from the inlet side passage 9 by the valve elements 5A and 5B.
Exhaust-side passages 10A and 10B connecting B to corresponding exhaust ports 8A and 8B are recessed.

The length of each exhaust-side passage 10A, 10B in the sliding direction is such that the corresponding exhaust port 8A corresponds to each of the outlet ports 7A, 7B.
.8B and the distance a between the outlet port 7A and 7
A length (a + 2b) or more, which is the sum of the length b in the sliding direction of B and the length b in the sliding direction of the exhaust ports 8A and 8B, is required. In this embodiment, the outlet ports 7A and 7B
Is set to b, the length of each exhaust-side passage 10A, 10B in the sliding direction is equal to the required length (a + 2b) of each exhaust-side passage 10A, 10B. The length (a +
From 3b), the inner sealing surface 15A necessary for ensuring the sealing performance between the inlet side passage 9 and the exhaust side passages 10A and 10B.
・ Set to the length 3b minus the length a in the sliding direction of 15B.

Further, the exhaust side passage 10 of each of the valve elements 5A and 5B
The inlet side passage 9 or the valve chamber 2 is provided on both sides of the A and 10B in the sliding direction.
The outer sealing surfaces 16A and 16B necessary for ensuring the sealing performance between the exhaust passages 10A and 10B are provided, so that the length of each valve element 5A and 5B in the sliding direction is (2
a + 3b). The stroke of each of the valve elements 5A and 5B is, as shown in FIGS.
It is only necessary to selectively overlap the upper and lower outlet ports 7A and 7B with each other, so that the distance b between the two outlet ports 7A and 7B and the length in the sliding direction of the two outlet ports 7A and 7B The length is set to 2b, which is obtained by subtracting the length b of the entrance side passage 9 in the sliding direction from 2 × b.

Therefore, the length of the valve seat 3 in the sliding direction is
The length in the sliding direction of the two valve elements 5A and 5B is 2 × (2a + 3
b), the distance b between the two valve bodies 5A and 5B, and the length (4a +
9b), and the length of the conventional valve seat 103 (4b + 11b)
By making the length 2b shorter than that of the above, the slide valve can be made smaller in the sliding direction.

The total length 2 × (2a + 3b) of the valve elements 5A and 5B in the sliding direction is shorter than the conventional length (4a + 9b) of the integral valve element 105 in the sliding direction.・
Since the sliding resistance of the valve 5B is reduced, the sliding resistance of the valve elements 5A and 5B is reduced, and the switching speed of the valve can be increased with a small thrust. Further, since the thrust of the spool 4 can be reduced, the diameter of the spool 4 can be reduced, and the size of the slide valve can be reduced in the direction perpendicular to the sliding direction.

By the way, as shown in FIG. 6, for example, when a thrust F acts on the valve elements 5A (5b) and 105 from the spool 4, the valve element 5A on the opposite side of the point of application of the thrust F is applied.
(5b) Intersection P1 between the end surface of 105 and the upper surface 14 of the valve seat 3
With P2 as a fulcrum, a force for lifting the valve element 5A (5b) .105 from the upper surface 14 of the valve seat, that is, a prying force F1 or F2 is generated.

The opening force F1 (or F2) is defined by the angle θ1 between the straight line connecting the point of force and the fulcrum with the upper surface 14 of the valve seat 3.
(Or θ2), the force F1 acting in the sliding direction
(Or F2) multiplied by sin θ1 (or sin θ2), and therefore, the value becomes larger as the distance between the power point and the fulcrum P1 (or P2) becomes shorter. Therefore, the valve elements 5A and 5B
In this divided example, the distance between the fulcrum and the fulcrum P1 is a valve body.
Since the distance between the force point and the fulcrum P2 of the conventional example in which the valve body 105 is integrally formed is shorter than that of the conventional example in which the valve body 105 is integrated, the valve can be switched at a higher speed.

Further, since the length (2a + 3b) of each of the valve elements 5A and 5B in the sliding direction is smaller than half the length of the conventional integral valve element 105 in the sliding direction (4a + 9b),
It is possible to obtain the same or higher prying force with the conventional thrust than the conventional one. Therefore, the thrust can be made smaller than before, and the diameter of the spool 4 can be made smaller, so that the slide valve can be made smaller in the direction perpendicular to the sliding direction.

Small diameter portions 9A and 9B into which the valve bodies 5A and 5B are fitted are formed between the center and both ends of the spool 4. The length of the small diameter portions 9A and 9B in the sliding direction is the valve body. 5A and 5B are slightly longer than the length in the sliding direction. Thereby, for example, the spool 4 is connected to each of the valve bodies 5A and 5B.
When the stroke end is reached by pushing downward in FIG. 1, a minute gap g is formed between the ends of the small diameter portions 9A and 9B and the end surfaces of the valve seats 5A and 5B on the traveling direction side.

Next, when the traveling direction of the spool 4 is switched, first, only the spool 4 starts to move, so that the spool 4 can be started with a small force without being affected by the static friction of the valve elements 5A and 5B. . Then, after the spool 4 starts to move, the spool 4 collides with each of the valve elements 5A and 5B in a state where the inertia force is applied to the spool 4 to some extent, so that the stationary state of the valve elements 5A and 5B can be easily performed by the impact force. Torn,
The valve elements 5A and 5B are quickly pushed upward in FIG. 1 by the spool 4 and start to move, thereby speeding up the switching of the valves.

Here, in order to start the valve elements 5A and 5B, it is possible to start the valve elements 5A and 5B with a weaker thrust when a shock is applied than when a thrust is applied statically. By making the spool 4 even smaller in diameter, the entire slide valve can be made even smaller in the direction perpendicular to the sliding direction. The valve seat retainer 12 has one inlet port 17 opening on the upper surface of the pipe mount 13 and two outlet ports.
The inlet passage 20, the outlet passages 21A and 21B and the exhaust passage 22 correspond to 18A and 18B and the two exhaust ports 19A and 19B.
A.22B is provided.

The inlet passage 20 is branched forward and backward in the valve retainer 12, and is opened at the upper surface of the valve retainer 12 in a long hole extending in the width direction to reach both ends in the width direction. The inlet port 17 of the mounting base 13 is connected to two inlet ports 6 formed on both side edges of the valve seat 3 through the inlet passage 20.
・ We are trying to communicate with 6. Although the slide valve can be configured to be switched by manual operation, in this embodiment, cylinder chambers 23A and 23B are formed on both sides of the valve chamber 2 and inserted into each of the cylinder chambers 23A and 23B. The spool 4 is driven by supplying / discharging compressed air to / from pressure receiving chambers 25A / 25B formed on both outer sides of the pistons 24A / 24B through pilot solenoid valves 26A / 26B.

In this case, since the thrust of the spool 4 can be reduced as described above, the diameters of the cylinder chambers 23A and 23B and the pistons 24A and 24B can also be reduced, and the entire slide valve including these operating devices can be used. It can be small.

[0040]

As described above, according to the present invention, the inlet port is opened at the side edge of the upper surface of the valve seat, and the two outlet ports are arranged at the center of the upper surface of the valve seat in the sliding direction. Exhaust ports are respectively opened on both outer sides of the upper surface of the valve seat in the sliding direction of the two outlet ports, and the valve body comprises two valve bodies divided in the sliding direction. An inlet-side passage for selectively communicating both outlet ports with the valve chamber is formed, and an exhaust-side passage for connecting the outlet port shut off from the valve chamber to the exhaust port is formed in each valve element. Therefore, the length of the valve body and the valve seat in the sliding direction can be reduced as compared with the conventional example in which the five ports are opened side by side in the sliding direction. can do.

Further, since the length of the valve body in the sliding direction can be reduced, the sliding resistance of the valve body is reduced, and the switching speed of the valve can be increased. Further, since the sliding resistance of the valve body is reduced, the thrust of the spool can be reduced, and the diameter of the spool can be reduced so that the entire slide valve can be downsized even in a direction perpendicular to the sliding direction.

In the present invention, since the valve element is formed by dividing the valve element into two parts in the sliding direction, the prying force with respect to the thrust acting on each valve element is increased, and the sliding resistance of the valve element is reduced within a short time. Can be rapidly reduced, and the switching speed of the valve can be further increased. Further, since the prying force with respect to the thrust increases, the thrust can be reduced, and the diameter of the spool can be further reduced, and the entire slide valve can be further reduced in the direction perpendicular to the sliding direction.

Also, in the present invention, the length of each small diameter portion of the spool in the sliding direction is set slightly larger than the length of each valve body in the sliding direction. A gap is formed between the end and the end face of the valve body,
After this, when the spool starts to move in the opposite direction, the spool can be easily started with a weak force ignoring the static friction of the valve body. It collides with the end face of the stationary valve element, and applies a prying force to the valve element.

Therefore, the stationary state of the valve body is easily broken with a smaller thrust than before, the valve body starts to move quickly, and the switching speed of the valve is further increased. Further, since the thrust can be made smaller than before, the diameter of the spool can be further reduced and the entire slide valve can be further reduced in the direction perpendicular to the sliding direction.

[Brief description of the drawings]

FIG. 1 is a vertical side view of one embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main part of one embodiment of the present invention.

FIG. 3 is a schematic diagram of a valve body and a valve seat according to an embodiment of the present invention when A is connected.

FIG. 4 is a schematic view of a valve element and a valve seat according to an embodiment of the present invention in a transition period.

FIG. 5 is a schematic diagram of a valve body and a valve seat according to an embodiment of the present invention when B is connected.

FIG. 6 is a schematic diagram comparing the prying force of the present invention and a conventional example.

FIG. 7 is a longitudinal sectional side view of a conventional example.

FIG. 8 is a schematic view of a conventional valve body and a valve seat when A is connected.

FIG. 9 is a schematic view of a conventional valve body and a valve seat in a transition period.

FIG. 10 is a schematic diagram of a conventional valve body and a valve seat when B is connected.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 ... Valve box 2 ... Valve room 3 ... Valve seat 4 ... Spool 4A / 4B ... Small diameter part 5A / 5B ... Valve 6 ... Inlet port 7A, 7B ... Outlet port 8A, 8B ... Exhaust port 9 ... Inlet side passage 10A 10B ... Exhaust side passage

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-29123 (JP, A) JP-A-61-6468 (JP, A) Fully open 63-187777 (JP, U) Really open 1962 86482 (JP, U) Japanese Utility Model Application Showa 59-191470 (JP, U) Japanese Utility Model Application Showa 62-8468 (JP, U) Japanese Utility Model Application Showa 62-8467 (JP, U) (58) Field surveyed (Int. ⁷ , DB name) F16K 3/00-3/36 F16K 11/00-11/24 F16K 27/00-27/04 F16K 31/12-31/165

Claims (1)

(57) [Claims] 1. A valve seat that covers a lower surface of a valve chamber formed in a valve box, a spool that is inserted into the valve chamber so as to be able to advance and retreat, and a valve body that is driven by the spool and moves along the upper surface of the valve seat. The valve seat has an inlet port opened on the upper surface, two load connecting outlet ports that are alternatively connected to the inlet port, and two exhaust ports corresponding to each outlet port, By sliding the valve body, one of the two outlet ports is alternatively connected to the inlet port, and the other one of the outlet ports is connected to the corresponding exhaust port. An inlet port is opened at the side edge of the upper surface of the valve seat, and both outlet ports are opened in the center of the upper surface of the valve seat in a sliding direction, and the sliding direction of the two outlet ports on the upper surface of the valve seat is provided. The corresponding exhaust ports are open on both outer sides of the The valve body is composed of two valve bodies divided in the sliding direction, and an inlet-side passage is formed between the two valve bodies to selectively connect the valve chamber to one of the two outlet ports. At the same time, an exhaust-side passage is formed on the lower surface of each valve body to communicate an outlet port shut off from the valve chamber to a corresponding exhaust port, and each valve body is located between the center and both ends in the sliding direction of the spool. A slide valve, wherein two small-diameter portions into which are fitted are formed, and the length of each small-diameter portion in the sliding direction is slightly longer than the length of each valve element in the sliding direction.