JPH03103685A - 4-way 4-position electromagnetic pilot switching valve - Google Patents

Abstract

PURPOSE:To simplify an electric circuit by a method wherein a four-way four- position electromagnetic pilot switching valve comprises a single parent valve switchable to four positions and two electromagnetic pilot switching valves switchable in three ways and to two positions. CONSTITUTION:When a solenoid 44 of an electromagnetic pilot switching valve 30 is excited, a pressure exerted on the outer pressure receiving surface of a first spool 22 is reduced and first and second spools 22 and 23 are both moved rightward. Similarly, when a solenoid 45 is excited, the first and second spools 22 and 23 are both moved leftward. When the solenoids 44 and 45 are both excited, the first spool 22 is moved rightward and the second spool 23 is moved leftward. This constitution reduces a cost through simplifying of constitution of an electric circuit, and reduces a mounting space.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a four-way, four-position electromagnetic pilot switching valve for hydraulic use. [Prior Art] Conventionally, when constructing a 4-way, 4-position electromagnetic pilot switching valve in a hydraulic circuit, it has been constructed by combining two pilot switching valves as shown in FIG. 5, for example.

That is, an electromagnetic pilot switching valve 1 that can be switched to 3 positions.
A switching valve 3 that can be switched to 3 positions is connected between the electromagnetic pilot switching valve 2 that can be switched to 2 positions, and an oil chamber 5 of one of the cylinders 4 that serves as a drive actuator is connected to the electromagnetic pilot switching valve 2. The A port of the switching valve 3 and the C port of the switching valve 3 are connected to an oil passage 6, and the other oil chamber 7, which is separated by the piston 4a, is connected to the D port of the electromagnetic pilot switching valve 2. In addition, the hydraulic power source 8 is connected to the P1 port of the electromagnetic pilot switching valve 1 and the P2 port 1 of the switching valve 3, respectively.
T1 port of electromagnetic pilot switching valve 1 and T2 of switching valve 3
The T3 port of the electromagnetic pilot switching valve 2 is connected to the tank 10, and the B port of the electromagnetic pilot switching valve 2 and the E port of the switching valve 3 are connected.

When all the solenoids are not energized, the electromagnetic pilot switching valves 1 and 2 and the switching valve 3 are in the positions shown in FIG. 5, and all ports are in a blocked state.

Furthermore, when only the solenoid 11 of the electromagnetic pilot switching valve 1 is energized, the electromagnetic pilot switching valve 1 is switched so as to move to the right from the illustrated position shown in FIG. , the switching valve 3 is switched to the right from the illustrated position. Therefore, high pressure from the oil pressure source 8 acts on the oil chamber 5 of the cylinder 4 through the oil passage 9 from the P2 boat via the C port, and the oil chamber 7 acts on the D, B of the electromagnetic pilot switching valve 2.
From the port to tank 1 via E and T2 boats of switching valve 3
0, the piston 4a moves (projects) to the right in FIG. Furthermore, when the solenoid 12 of the electromagnetic pilot switching valve 1 is energized, the electromagnetic pilot switching valve 1 moves to the left from the position shown in FIG. In order to act on the line PL2, the switching valve 3 is switched to the left from the illustrated position,
High pressure from the hydraulic source 8 is passed from the Pz port through the E boat,
In order to increase the pressure by acting on the oil chamber 7 of the cylinder 4 through the B and D ports of the electromagnetic pilot switching valve 2, the piston 4a returns to the left in FIG. Furthermore, when the solenoids 11 and 13 of the electromagnetic pilot switching valves 1 and 2 are both energized, the pilot line PL
High pressure acts on I, the switching valve 3 switches to the right from the illustrated position, and the electromagnetic pilot switching valve 2 also switches to the right from the illustrated position, and the high pressure of the hydraulic source 8 flows from the P2 boat to the C port. The same pressure acts on the oil chamber 7 of the cylinder 4 through the A port and the D port of the electromagnetic pilot switching valve 2, and the same pressure also acts on the oil chamber 5 via the oil passage 6 and the oil passage 9. The piston 4a of the cylinder 4 moves quickly to the right in FIG.

[Problem to be solved by the invention]

However, when a hydraulic circuit capable of switching to four positions is constructed by combining two pilot switching valves in this way, the solenoid is connected to the solenoid 11 of the electromagnetic pilot switching valve 1 and 12 and the solenoid 13 of the electromagnetic pilot switching valve 2, a total of 3' is required, and three electrical input terminals are required for each solenoid, making the electrical circuit that much more complicated. At the same time, a large amount of installation space is required, and the cost is also high.

This invention was made in view of the above problems,
To provide a 4-way, 4-position electromagnetic pilot switching valve that reduces the number of used solenoids, reduces the number of electrical input terminals, simplifies the configuration of an electrical circuit, requires less installation space, and reduces costs. The purpose is to

[Means to solve the problem]

In order to achieve the above object, the present invention constructs a 4-way, 4-position electromagnetic pilot switching valve using one master valve that can be switched to 4 positions and two electromagnetic pilot switching valves that can switch between 3 directions and 2 positions. Alternatively, the first spool and the second spool are slidably housed in the parent valve, and the hydraulic pressure from the hydraulic source is applied to the pressure receiving surfaces on both sides of each spool at the neutral position of the first and second spools. At the same time, a small diameter part is formed on one of the mutually opposing inner spool end faces of each spool, and a small diameter part sliding hole into which the small diameter part is inserted is formed on the other, or the outer spool end face is made smaller than the inner spool end face. By increasing the area or inserting a spring between the outer end surface of the spool and the cover, a thrust force is applied to both spools in the direction of pressing them against each other, and one of the two electromagnetic pilot switching valves is When switching, the pressure acting on the outside pressure receiving surface of the first spool decreases and both the first and second spools move in the same direction, and when the other electromagnetic pilot switching valve is switched, the pressure acting on the outside pressure receiving surface of the first spool decreases, and when the other electromagnetic pilot switching valve is switched,
When the pressure acting on the pressure receiving surface on the outside of the spool decreases and both the first and second spools move in the opposite direction to the above-mentioned moving direction, and both the above-mentioned two electromagnetic pilot switching valves are switched, the first , and the second spools are moved in directions that separate them from each other.

Further, in the above-mentioned 4-way 4-position electromagnetic pilot switching valve, the non-opposed outer end surfaces of the first and second spools in the parent valve are each pressed to a predetermined position via a centering washer to regulate the two spools. It is more effective to provide a position regulating spring that keeps both spools in the neutral position.

[For production]

According to the 4-way, 4-position electromagnetic pilot switching valve constructed in this way, unless the positions of the two electromagnetic pilot switching valves are switched together, the pressure receiving surfaces on both sides of the first and second spools in the parent valve will be affected. Because the hydraulic pressure from the hydraulic source acts on each,
They both remain balanced in a neutral position.

Additionally, when one position of the electromagnetic pilot switching valve is switched, the pressure acting on the outer pressure receiving surface of the first spool decreases, causing the above balance between the first and second spools to collapse, causing both spools to move together. moving in the same direction, the other am
When the pilot switching valve is switched, the pressure acting on the outer pressure receiving surface of the second spool is reduced, so that both the first and second spools similarly move in the opposite direction to the above-mentioned movement direction.

Furthermore, when the two electromagnetic pilot switching valves are switched together, the first and second spools move in directions that separate them from each other.

Therefore, although the structure uses two electromagnetic pilots 1 and switching valves, it is possible to switch to four hydraulic circuits (four-position switching).

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a configuration diagram showing a 4-way, 4-position electromagnetic pilot switching valve according to the present invention.

These 4 directions, 4 positions, 1! The magnetic pilot switching well includes a master valve 20 that can be switched to four positions, and three valves that are integrally fixed to the upper part of the master valve 20.
The electromagnetic pilot switching valve 30 consists of two electromagnetic pilot switching valves that can switch between two positions in each direction. The parent valve 20 has a sliding hole 2 formed in the parent valve body 21.
1a, a first spool 22 and a second spool 23 are slidably fitted into the first spool 22.2.
Pressure receiving surfaces Aa, Ab, on both sides of each spool at the neutral position of 3.
Hydraulic pressure from a hydraulic source is applied to Ac and Ad, and covers 24.25 are integrally attached to the outside of the first and second spools 22.23, respectively,
It features oil chambers 2B and 27 inside the cover. A spring 29 is provided in the oil chamber 26 inside the cover, and one end of the spring 29 is brought into contact with the inner surface of the cover, and the other end is brought into contact with a spring receiving portion 21b formed on the parent valve body 21 via a centering washer 31. ing.

Similarly, a spring 33 is provided in the oil chamber 27 in the cover, and one end of the spring 33 is brought into contact with the inner surface of the cover, and the other end is brought into contact with the spring receiving portion 21Q of the parent valve body 21 via a centering washer 34.

The first and second spools 22 and 23 have substantially the same external shape, and are slidably fitted into the sliding hole 21a in a symmetrical positional relationship.

The first spool 22 has a first land portion 22 .
and a second land portion 22b are formed, and a tip small diameter portion 22Q is formed on the left side in FIG. A small diameter portion 2E5c is formed at the tip.

Further, a small diameter portion 22d having the smallest diameter is formed on the left inner pool end surface of the first spool 22 and the second spool 23 in FIG. 23 is formed with a small-diameter sliding hole 23d into which the small-diameter portion 22d is slidably fitted, and the small-diameter sliding hole 23d becomes a tank line connecting to the tank formed in the parent valve body 21. Each pressure receiving surface A a , A on both sides of the first and second spools 22 , 2 communicates with the port.
The effective areas of b, Ac, and Ad are respectively expressed as the outer pressure receiving surface Ac
The sum of the inner pressure-receiving surfaces Aa and Ab side is made different from each other so that the sum thereof is larger than the sum of the inner pressure-receiving surfaces Aa and Ab side, so that thrust in the direction of pressing against each other is applied to both spools by hydraulic pressure.

Therefore, the first spool 22 and the second spool 23
As shown in FIG. 1, the left end face of the small diameter tip portion 22C and the right end face of the small diameter tip portion 2SQ are brought into pressure contact by the hydraulic pressure due to the difference in their pressure receiving surfaces, and are balanced at the neutral position shown.

In addition, in the parent valve body 21, a P port communicating with a hydraulic power source, and A ports and B ports for connecting to seven actuators such as cylinders, etc., are placed at a predetermined interval along with a T port in a sliding hole 21a. tank communication oil which communicates between the first and second land portions 22a and 22b and the T-boat when the first spool 22 is in the neutral position shown in FIG. Road 35
is formed.

In this embodiment, the spring 29. 33i functions as a position regulating spring that keeps both the first and second spools 22, 23 in neutral positions.

On the other hand, the electromagnetic pilot switching valve 30 has a first pilot spool 42 and a second pilot spool 43 slidably fitted into a sliding hole 41a formed in a pilot valve body 41. pilot spool 4
Solenoids 44 and 45 are integrally attached to the outside of each of the pilot valve bodies 41 and 43, and the push pins 44a and 45a of the solenoids 44 and 45 are connected to the pilot valve body 41.
The pilot spools protrude into oil chambers 46 and 47 formed at both ends of the pilot spools, and their tips abut against the outer end surfaces of the first and second pilot spools 42 and 43, respectively. A spring is provided in the oil chamber 46, one end of which is brought into contact with a spring receiver formed on the solenoid 44, and the other end is connected to a spring receiver 41b formed on the pilot valve body 41 via a centering washer 51. It is in contact with the

Similarly, a spring 53 is provided in the other oil chamber 47, and one end of the spring 53 is brought into contact with a spring holder formed in the solenoid 45, and the other end is connected to the spring holder 41c of the pilot valve body 41 via a centering washer 54. It is in contact with the

The first and second pilot spools 42 and 43 are spools having the same shape, each having a first land portion 42a and a second land portion 42b, and a first land portion 43a and a second land portion 43b. It is slidably fitted into the sliding hole 41a in a symmetrical positional relationship, and the main spring 55 is inserted therebetween.

In addition, the pilot valve body 41 has a hydraulic chamber 5 formed in its middle, and a Tp which communicates with the hydraulic chamber 5 and also communicates with the tank communication channel 35 in the main valve body 21.
Port and cover inner chambers 26 and 27 in the parent valve body 21
The Ap port and the Bp boat communicate with the oil passages 58 and 57, respectively, and the branch oil passages 58 and 5 merge within the parent valve body 21 and lead to the P boat.
A PPI boat and a ppz boat are formed, which communicate with each other on a daily basis.

When the solenoid 44 and 45 on both sides are not excited, the electromagnetic pilot switching valve 30
The pilot spools 42 and 43 are balanced and stopped at the neutral position shown in FIG.

In addition, in FIG. 1, 61 indicates the solenoids 44 and 45.
This is a conduit box that stores electrical input terminals etc. for driving the .

Next, the operation of this embodiment constructed as described above will be explained.

i) When not all solenoids are energized When all solenoids 44 and 45 are not energized, the spools of the master valve 20 and the electromagnetic pilot switching valve 30 are all maintained at the positions shown in FIG.

That is, high-pressure oil is supplied to the P boat of the master valve 20 from a hydraulic source, and it passes through each branch oil passage 58, 59 to the Pp1 boat in the three ports of the electromagnetic pilot switching valve and the P boat of the PP valve.
Since the second pilot spools 42 and 43 of the electromagnetic pilot switching valve 30 are located at the positions shown in FIG. 1, their PP1*
The high pressure acting on the PP2 port passes through the Ap port and the Bp boat and acts on the oil chambers 26 and 27 in each cover of the parent valve 20, respectively.

Therefore, the first spool 22 and the second spool in the parent valve 20
The spool 23 is connected to the P port and the oil chambers 26 and 2 in the cover.
Since the hydraulic pressure acting on 7 is the same, the 1st and 2nd
The first spool 22 is pushed leftward in FIG. 1, and the second spool 23 is pushed rightward in FIG. are balanced in the neutral position.

In this state, as shown in FIG. 1, the left end surface of the right centering washer 31 is pressed against the end surface of the spring receiving part 21b by the spring 29, and the left centering washer 34 is pressed against the spring 3 by the spring 29.
3, the right end surface is pressed against the end surface of the spring receiving part 21c, and these also cause the first
and second spools 22 and 23 are both maintained in the neutral position shown.

With each spool in its neutral position, the A, B, P, and T boats are all in a blocked circuit configuration as shown in FIG.

(n) When the solenoid 44 is energized When the solenoid 44 is energized, the push pin 4 4 a
projects to the left in FIG. 1, thereby causing the first pilot spool 42 to move from the position shown to the main spring 55.
It moves to the left against the biasing force and stops at a position where the reaction force is balanced.

Therefore, the PPI boat becomes blocked and the TP
The oil chamber 26 inside the cover allows communication between the boat and the Ap boat.
The oil inside flows out to the tank in the order of oil passage 56 → Ap boat 1 → Tp boat → tank communication oil passage 35 → T port.

As a result, the l-th spool 22 in the master valve 20 moves to the right from the position shown in FIG. 1 against the urging force of the spring 2, and reaches a position where it balances the reaction force of the spring 2. Stop. As the first spool 22 moves, the second spool 23 also moves to the right from the illustrated position by a thrust (hydraulic force) depending on the ratio of the left and right pressure receiving areas.

Therefore, P boat and B port communicate, and A port communicates with T port.
There is a circuit structure that communicates with the port.

(■ Situation A when the solenoid 45 is energized) When the solenoid 45 is energized, the push pin 45a protrudes to the right in FIG. move to the right and stop at a position that balances the reaction force.

Therefore, PP2 port goes into a blocked state and Tp
Since the port and Bp port communicate with each other, the oil chamber 27 inside the cover
The oil inside flows out to the tank in the order of oil passage 57 → Bp port → Tp boat → tank communication oil passage 35 → T port.

As a result, the second spool 23 in the master valve 20 moves to the left from the position shown in FIG. 1 against the biasing force of the spring 33, and stops at a position where it balances the reaction force of the spring 33. . As the second spool 23 moves, the first spool 22 also moves leftward from the illustrated position by a thrust according to the left and right pressure receiving area ratio.

Therefore, P port and A port communicate, and B port communicates with T port.
There is a circuit structure that communicates with the port.

When short solenoids 4 and 4 are set to , when both solenoids 44 and 45 are energized, the first pilot spool 42 moves to the left from the position shown in FIG. 1, and the second pilot spool 43 moves to the right, respectively. They stop at a position where they balance the reaction force of the main spring 55.

Therefore, the electromagnetic pilot switching valve 30
The pilot spools 42 and 43 of (it) and (
Since the oil chambers 26 and 27 in each cover of the main valve 20 are moved simultaneously to the positions described in Section 3), the oil in the oil chambers 26 and 27 in each cover of the main valve 20 flows out into the tank through the above-mentioned outflow path. Therefore, the first spool 22 in the parent valve 20 moves to the right from the position shown in FIG.
3 moves to the left, and they move each spring 2 and 33
It stops at a position where it balances the reaction force of .

Therefore, the circuit configuration is such that the P port communicates with both the A boat and the B port.

As described above, according to the 4-way 4-position electromagnetic pilot switching valve according to this embodiment, the hydraulic circuit can be switched to 4 positions (4 circuit configurations hj.) by the combination of energizing the two solenoids 44 and 45. can.

Therefore, one of the ports A and B in FIG. 1 is communicated with one of the oil chambers 5 and 7 of the cylinder 4 as shown in FIG. 5, and the other is connected to the other oil chamber. If it is communicated with the chamber, switching operation of 4 positions can be performed: ■ Piston stop, ■ Piston protrude,
■ Piston return and ■ Piston rapid forwarding can be performed.

FIG. 2 is a hydraulic circuit diagram showing the 4-way, 4-position electromagnetic pilot switching valve shown in FIG. 1 using hydraulic symbols.

As is clear from FIG. 2, the electromagnetic pilot switching valve 30 (the vertical positional relationship with the master valve 20 is reversed for convenience with respect to FIG. 1) is composed of two electromagnetic pilot switching valves 30A. and 30B, and when the solenoids 44 and 45 of the electromagnetic pilot switching valves 30A and 30B are not energized, the electromagnetic pilot switching valve 30 and the master valve 20 are both in the positions shown in the figure, so that A, B, All P and T ports have a block state circuit configuration.

Furthermore, when only the solenoid 44 is energized, the position of the electromagnetic pilot switching valve 30A is switched to the right from the illustrated position, and the pilot line PL. communicates with the T-boat,
The master valve 20 moves to the right from the position shown in FIG. Therefore, the circuit configuration is such that the P port communicates with the B boat, and the A boat communicates with the T port.

Furthermore, when only the solenoid 45 is energized, the position of the electromagnetic pilot switching valve 30B is switched to the left from the position shown in the figure, and the pilot line PL2 is communicated with the T port, so that the master valve 20 is moved from the position shown in FIG. Move to the left position (move two steps as shown). Therefore, the circuit structure is such that the P port communicates with the A port and the B port communicates with the T boat.

Furthermore, when both solenoids 44 and 45 are energized,
Since the electromagnetic pilot switching valves 30A and 30B switch together as in the above case, and the pilot lines PL1 and PL2 both communicate with the T port, the master valve 20 switches one position to the left from the position shown in FIG. Move to position. Therefore, a differential circuit is constructed in which the P port communicates with both the A port and the B port.

FIG. 3 shows another embodiment of the parent valve in which the spool has a different shape, and parts corresponding to those in FIG. 1 are given the same reference numerals.

This master valve 60 differs from the master valve 20 in FIG. 1 by eliminating the small diameter part 22d at the left end of the spool of the first spool 22, and by removing the small diameter part 2''5d of the corresponding small diameter part sliding hole 2''5d of the second spool 23. By eliminating the
The second spool 23 also has a second land portion having the same diameter as the second land portion 22e of the first spool 22, so that the sum of the pressure-receiving surfaces Ac and Ad on the outside of the spool is made thicker than the sum of the pressure-receiving surfaces Ac and Ad on the outside of the spool. This is the point that forms 23e.

Even in this case, the thrust force in the direction of pressing the first and second spools 22 and 23 into contact with each other can be applied by hydraulic pressure, so that the same effect as in the above-mentioned embodiment can be achieved6. Another embodiment of the parent valve is shown, and parts corresponding to those in FIGS. 1 and 3 are given the same reference numerals. This master valve 70 is different from the master valve 60 in FIG. A spring 7 is formed with a spring receiver 22f on the right side end face in FIG. 4 of the non-opposing outer side, and urges the l-th spool 22 therein to the left in FIG. 4 by the force of the spring.
1 is inserted between the cover 24 and the second spool 23 also has a second land portion 2 having the same diameter as the first land portion 23a.
3b and a spring receiver 23 at the left end of the spool.
This is the point where the spring 71 is inserted between the spring 71 and the cover 25. Even if you do this, the first and second
Since the spools 22 and 23 can be given a thrust in the direction of pressing them against each other by the force of the spring 71, it is possible to achieve the same effects as in each of the above-described embodiments.

〔Effect of the invention〕

As explained above, according to the present invention, two electromagnetic pilot switching valves capable of switching between three directions and two positions are used to
Since the position can be switched, differential circuit functions can be added, which improves functionality, and the number of electrical input terminals requires only two people, which simplifies the electrical circuit configuration and reduces costs, and also saves installation space. Less is needed.

Furthermore, manufacturing is easy because a 4-way, 4-position electromagnetic pilot switching valve can be created by simply changing the spool of the parent valve from the conventional 4-way, 3-position magnetic pilot switching valve.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a 4-way, 4-position electromagnetic pilot switching valve according to the present invention; Fig. 2 is a hydraulic circuit diagram showing the 4-way, 4-position electromagnetic pilot switching valve of Fig. 1 using hydraulic symbols; Fig. 3 is a schematic diagram showing another embodiment of the parent valve with a different shape of the spool, and Fig. 4 is a schematic diagram similar to Fig. 3 showing another embodiment of the parent valve with a different shape. ! FIG. 5 is a hydraulic circuit diagram showing an example of a 4-way, 4-position electromagnetic pilot switching valve constructed by combining two conventional pilot switching valves. 20... Main valve 30... Solenoid pilot switching valve 21a, 41a... Sliding hole 22... First spool 22d... Small diameter portion 23... Second spool 23d... Small diameter Part sliding holes 24, 25...
Cover 29.33, 49.53...Spring 31,
34,51.54...centering washer 44.
45... Solenoid

Claims (1)

[Scope of Claims] 1. A 4-way, 4-position electromagnetic pilot switching valve comprising one master valve that can be switched to 4 positions and two electromagnetic pilot switching valves that can be switched to 2 positions in 3 directions, A first spool and a second spool are slidably housed in the valve, and hydraulic pressure from a hydraulic source is applied to the pressure receiving surfaces on both sides of each spool at the neutral position of the first and second spools. ,
A thrust is applied to each of the spools in the direction of pressing them against each other,
When one of the two electromagnetic pilot switching valves is switched, the pressure acting on the outer pressure receiving surface of the first spool decreases, causing both the first and second spools to move in the same direction, causing the other spool to move in the same direction. When the electromagnetic pilot switching valve is switched, the pressure acting on the outer pressure receiving surface of the second spool decreases, and both the first and second spools move in the opposite direction to the moving direction, and the two spools move in the opposite direction to the moving direction. 4. A 4-way, 4-position electromagnetic pilot switching valve, characterized in that when both of the electromagnetic pilot switching valves are switched, the first and second spools move in directions away from each other. 2. The four-way, four-position electromagnetic pilot switching valve according to claim 1, wherein one of the mutually opposing inner spool end surfaces of the first and second spools in the parent valve has a small diameter portion, and the other has a small diameter portion. A small-diameter sliding hole into which the part is slidably inserted is formed, and the small-diameter sliding hole is communicated with the tank line, and the effective area of the pressure-receiving surfaces on both sides of each spool is adjusted toward the outer pressure-receiving surface side. A 4-way, 4-position electromagnetic pilot switching valve characterized in that the spools are made to differ so that the spools are larger so that a thrust force is applied to both spools in a direction in which they are brought into pressure contact with each other by hydraulic pressure. 3. In the 4-way 4-position electromagnetic pilot switching valve according to claim 1, the area of the outer spool end face that does not face the inner spool end face that faces each other of the first and second spools in the parent valve is increased. A four-way, four-position electromagnetic pilot switching valve characterized in that a thrust force is applied to both spools by hydraulic pressure in a direction in which they press against each other. 4. The four-way, four-position electromagnetic pilot switching valve according to claim 1, wherein a spring is inserted between the cover and the outer end surfaces of the first and second spools in the parent valve, which do not face each other, so that both spools can be operated. A four-way, four-position electromagnetic pilot switching valve characterized in that a thrust force is applied in a direction in which the two are brought into pressure contact with each other by the force of the spring. 5. In the 4-way, 4-position electromagnetic pilot switching valve according to any one of claims 1 to 4, the non-opposing outer end surfaces of the first and second spools in the parent valve are respectively set at predetermined positions via centering washers. A 4-way, 4-position electromagnetic pilot switching valve characterized by being provided with a position regulating spring that presses and regulates the spools in a neutral position and keeps both spools in a neutral position.