JP6721349B2 - Pilot type solenoid valve - Google Patents

Description

The present invention relates to a pilot-type solenoid valve that includes an electromagnet-driven pilot valve and that switches a main valve with a pilot fluid controlled by the pilot valve.

This type of pilot solenoid valve includes a pilot valve that can switch the pilot flow passage against the spring force by the excitation of an electromagnet, and a main valve that can switch the main flow passage by the pressure of the pilot fluid that acts by switching the pilot flow passage. Equipped with. The pilot valve is provided with a throttle groove in the pilot valve body, and when the electromagnet is de-excited to return the main valve to the neutral position by spring force, the pilot fluid discharged to the low pressure side is throttled to control the main valve. The main valve body's return speed is slowed down to reduce the shock at the time of return.

Japanese Patent Laid-Open No. 11-257504

However, in such a conventional pilot type solenoid valve, when switching the main valve, the flow velocity of the fluid flowing through the main flow path cannot be made gentle, and therefore the switching shock at the time of switching cannot be sufficiently reduced.

An object of the present invention is to provide a pilot type solenoid valve capable of reducing switching shock when switching the main valve.

In order to achieve this object, the present invention has taken the following means. That is,
A pilot valve that operates the pilot valve body by exciting or de-exciting the electromagnet to switch the pilot flow path, and a main valve that operates the main valve body by the action or non-action of the pilot fluid flowing in the pilot flow path to switch the main flow path. And a throttle valve for restricting control of the pilot fluid flowing through the pilot flow passage, and a main valve body of the main valve is provided with a throttle portion for restricting control of the fluid flowing through the main flow passage. A pilot supply flow path for supplying a pilot pressure fluid from a pressure source, a first pilot load flow path, a second pilot load flow path, and a pilot discharge flow path connected to the low pressure side. A first switching position for switching and communicating the flow passage to the pilot discharge flow passage and switching and communicating the second pilot load flow passage to the pilot supply flow passage; and a first switching position for switching and communicating the first pilot load flow passage to the pilot supply flow passage. The throttle valve has three positions, a second switching position for switching and communicating the two pilot load flow paths to the pilot discharge flow path, and a neutral position. The throttle valve is a unidirectional flow of the pilot fluid flowing through the first pilot load flow path. A first non-return valve body having a cylindrical shape that separates the valve from the valve seat to make it a free flow, and controls the flow of the pilot fluid in the other direction to sit on the valve seat and make the control flow to flow through the throttle hole; A first throttle valve body that is fitted to the stop valve body and that adjusts the opening degree of the throttle hole formed in the first check valve body by advancing and retracting by a turning operation, and a pilot that flows through the second pilot load flow path. Cylindrical second non-return valve that allows the flow of fluid in one direction to separate from the valve seat to be a free flow, and allows the flow of pilot fluid in the other direction to sit on the valve seat and flow through the throttle hole as a control flow A valve body and a second throttle valve body which is fitted to the second check valve body and which adjustably sets the opening degree of a throttle hole formed in the second check valve body by advancing and retracting by a turning operation, An abutting portion that comes into contact with the first throttle valve body and the second throttle valve body to regulate the axial movement amount is provided at the axial tip end, and the main valve uses a main flow path to supply a pressure fluid from a pressure source. It comprises a supply flow path, a first main load flow path connected to the load side, a second main load flow path, and a main discharge flow path connected to the low pressure side. The first main load flow path is used as the main discharge flow path. A first switching position for switching and communicating the second main load flow path with the main supply flow path; and a first switching path for communicating the first load flow path with the main supply flow path and the second main load flow path for main discharge flow. The first working chamber and the second working chamber, which have three positions, that is, a second switching position for switching and communicating with the passage and a neutral position, and which introduces a pilot fluid that acts on the main valve body, serve as a first pilot load flow path. Second pilot negative The main valve body is switched to the first switching position by introducing the pilot fluid into the first working chamber, and the main valve body is switched to the second switching position by introducing the pilot fluid into the second working chamber. The main valve body is set to the neutral position by drawing the pilot fluid from both working chambers, and the maximum axial movement amount of the main valve body is regulated. A screw member that sets the maximum flow rate flowing in the load passage is provided so that the throttle portion switches the main valve body from the neutral position to the first switching position or the second switching position. Alternatively, the pilot type solenoid valve is characterized in that the fluid flowing from the second main load flow passage to the main discharge flow passage is throttle-controlled.

In this case, the throttle portion flows from the main supply flow passage to the first main load flow passage or the second main load flow passage during a switching transition period in which the main valve body is switched from the neutral position to the first switching position or the second switching position. The fluid may be throttle-controlled. Further, the main valve, the pilot valve, and the throttle valve may be arranged such that the main valve is at the lowest position and the throttle valve and the pilot valve are sequentially stacked.

As described above in detail, in the invention described in claim 1, when the main valve is switched from the neutral position to the first switching position or the second switching position, the first throttle valve body or the second throttle valve body of the throttle valve is provided. Restricts the pilot fluid flowing through the pilot flow passage, and restricts the fluid flowing from the first main load flow passage or the second main load flow passage to the main discharge flow passage by the throttle portion provided in the main valve body. Therefore, the switching speed of the main valve body can be moderated by the throttle control of the pilot fluid by the first throttle valve body or the second throttle valve body of the throttle valve , and the first main body in the transitional transition period of the main valve body can be provided by the throttle portion. Since the flow velocity of the fluid flowing from the load passage or the second main load passage to the main discharge passage can be made gentle, the switching shock of the main valve can be reduced.

Further, in the invention described in claim 2, when the main valve is switched from the neutral position to the first switching position or the second switching position, the pilot flow path is formed by the first throttle valve body or the second throttle valve body of the throttle valve. The throttle control provided on the main valve body controls the flow of the pilot fluid, and also controls the flow of the fluid flowing from the main supply passage to the first main load passage or the second main load passage. Therefore, the switching speed of the main valve body can be moderated by the throttle control of the pilot fluid by the first throttle valve body or the second throttle valve body of the throttle valve, and the main supply flow in the transitional transition period of the main valve body can be controlled by the throttle portion. Since the flow velocity of the fluid flowing from the passage to the first main load passage or the second main load passage can be made gentle, the switching shock of the main valve can be reduced.

In the invention according to claim 3, in the main valve, the pilot valve and the throttle valve, the throttle valve and the pilot valve are sequentially stacked so that the main valve is at the lowest position. Therefore, the main valve, the pilot valve, and the throttle valve can be individually replaced, and can be easily changed according to the application.

It is a longitudinal cross-sectional view of the pilot type solenoid valve showing one embodiment of the present invention. It is a hydraulic circuit diagram of one embodiment. 2 is a cross-sectional view taken along the line AA of FIG. 1. 1A is a cross-sectional view taken along the line BB of FIG. 1, and FIG. 1B is a cross-sectional view taken along the line CC of FIG. 1A is a cross-sectional view taken along the line DD of FIG. 1, and FIG. 1B is a cross-sectional view taken along the line EE of FIG. It is a longitudinal section of other embodiments of the present invention. It is a hydraulic circuit diagram of other embodiment.

An embodiment of the present invention will be described below with reference to the drawings.
1 and 2, the pilot type solenoid valve is composed of a pilot valve 1, a main valve 2 and a throttle valve 3, and the main valve 2 is at the lowermost position and the throttle valve 3 and the pilot valve 1 are sequentially stacked. ing. The pilot valve 1 is an electromagnetically operated 4-port 3-position directional control valve, which is provided with two electromagnets 4A and 4B at both ends of the valve body 4, and has a spool-shaped pilot valve body to a sliding hole 4C formed in the valve body 4. 5 is slidably fitted in the axial direction. The pilot valve body 5 is held at the neutral position Z1 by the force of two springs 6A and 6B, and is switched to the first switching position X1 against the force of the spring 6B by exciting one electromagnet 4A, and at the same time to the other electromagnet 4B. It is provided so as to be freely switchable to the second switching position Y1 against the force of the spring 6A by the excitation. At the neutral position Z1, the pilot supply passage P1 for supplying the pilot pressure fluid from the pressure source P is cut off, and the first pilot load passage A1 and the second pilot load passage B1 are connected to the tank T on the low pressure side. It communicates with the pilot discharge flow path R1. At the first switching position X1, the first pilot load flow passage A1 is switched and communicated with the pilot discharge flow passage R1, and the second pilot load flow passage B1 is switched and communicated with the pilot supply flow passage P1. At the second switching position Y1, the first pilot load flow passage A1 is switched and communicated with the pilot supply flow passage P1, and the second pilot load flow passage B1 is switched and communicated with the pilot discharge flow passage R1.

Each of the pilot flow paths P1, A1, B1, and R1 has a pilot supply flow path P1 connected to the axial center of the sliding hole 4C, and a gap is provided at both axial ends of the pilot supply flow path P1 connection point. The first pilot load flow passage A1 and the second pilot load flow passage B1 are connected to each other, and the first and second pilot load flow passages A1 and B1 are connected in a bifurcated manner with a gap on each axial outer side. The pilot discharge flow path R1 formed in a shape is connected. Then, as shown in FIG. 3, the respective pilot flow paths P1, A1, B1, R1 are standardized and opened on the lower surface of the valve body 4.

The main valve 2 is a pilot operated 4-port 3-position directional control valve, which is provided with two substantially rectangular parallelepiped-shaped auxiliary valve main bodies 7A and 7B at both ends thereof. The spool-shaped main valve body 8 is fitted in the provided sliding hole 7C so as to be slidable in the axial direction. A first working chamber 9A and a second working chamber 9B for accommodating both ends of the main valve body 8 are formed in the sub-main valve main bodies 7A and 7B, and the main valve main body is provided in the first working chamber 9A and the second working chamber 9B. 7, the pilot fluid is introduced from the first pilot load passage A2 and the second pilot load passage B2 provided in the auxiliary main valve bodies 7A and 7B, and the springs 10A and 10B are housed therein. The main valve body 8 is held in the neutral position Z by the force of the two springs 10A and 10B, and is switched to the first switching position X against the force of the spring 10B by the introduction of the pilot fluid into the first working chamber 9A. By introducing the pilot fluid into the second working chamber 9B, it is possible to switch to the second switching position Y against the force of the spring 10A. At the neutral position Z, the main supply passage P2 for supplying the pressure fluid from the pressure source P is shut off, and the first main load passage A and the second main load passage B connected to the actuator on the load side are connected to the tank T. To the main discharge flow path R connected to the. At the first switching position X, the first main load passage A is switched and communicated with the main discharge passage R, and the second main load passage B is switched and communicated with the main supply passage P2. At the second switching position Y, the first main load passage A is switched and communicated with the main supply passage P2, and the second main load passage B is switched and communicated with the main discharge passage R.

Each of the main flow passages P2, A, B, and R connects the main supply flow passage P2 to the central portion in the axial direction of the sliding hole 7C, and has a gap at both axial ends of the main supply flow passage P2 connecting portion to form a first gap. The main load flow path A and the second main load flow path B are connected to each other, and a bifurcated shape is formed with a gap on each axial outer side of the first main load flow path A connection point and the second main load flow path B connection point. The main discharge flow path R formed in the above is connected. Then, as shown in FIG. 4(A), the respective main flow paths P2, A, B, R are standardized and opened on the lower surface of the main valve body 7. Further, as shown in FIG. 4B, a pilot supply passage P3 connected to the main supply passage P2, a pilot discharge passage R2 connected to the main discharge passage R, and a first pilot connected to the first action chamber 9A. A second pilot load flow passage B2 connected to the load flow passage A2 and the second action chamber 9B is standardized and opened on the upper surface of the main valve body 7.

In the main valve body 8, at the neutral position Z, a first land 8A that overlaps with the first main load flow path A connection point of the sliding hole 7C and a second land 8B that overlaps with the second main load flow path B connection point. Is provided with a gap in the axial direction. The first land 8A is formed with a tapered portion 8AA as a narrowed portion on the outer side in the axial direction, and the tapered portion 8AA is gradually reduced in diameter toward the outer side in the axial direction to switch from the neutral position Z to the first switching position X. First, the fluid flowing from the first main load passage A to the main discharge passage R is throttle-controlled to gradually increase the flow rate of the first main load passage A to the main discharge passage R. A tapered portion 8BB as a narrowed portion is formed on the second land 8B on the outer side in the axial direction, and the tapered portion 8BB is gradually reduced in diameter toward the outer side in the axial direction to switch from the neutral position Z to the second switching position Y. First, the fluid flowing from the second main load flow passage B to the main discharge flow passage R is throttle-controlled to gradually increase the flow rate flowing from the second main load flow passage B to the main discharge flow passage R. Then, the taper portion 8AA performs the meter-out control at the first switching position X and the taper portion 8BB at the second switching position Y, respectively.

Secondary main valve body 7A, a screw member 11A is in 7B defining the maximum axial movement of the main valve body 8, screwed 11B, screw members 11A, the 11B provided retractably by rotational operation, first main The maximum flow rate flowing from the load flow path A or the second main load flow path B to the main discharge flow path R is set to be changeable. Reference numerals 12A and 12B are lock nut members that restrict the rotation of the screw members 11A and 11B.

The throttle valve 3 throttle-controls the pilot fluid flowing through the first pilot load flow passage A3 and the pilot fluid flowing through the second pilot load flow passage B3, and the first pilot load flow passage A3 is the first pilot load flow passage of the main valve 2. The path A2 is connected to the first pilot load flow path A1 of the pilot valve 1, and the second pilot load flow path B3 is the second pilot load flow path B2 of the main valve 2 and the second pilot load flow path of the pilot valve 1. Connect to the road B1. As shown in FIGS. 5A and 5B, the throttle valve 3 includes a throttle valve body 13 having a substantially rectangular parallelepiped shape, and the throttle valve body 13 has a pilot supply passage P4, a pilot discharge passage R3, and a first pilot load flow. The path A3 and the second pilot load flow path B3 are formed so as to penetrate in the vertical direction, and are standardized and opened on the upper surface and the lower surface. The pilot supply flow passage P4, the pilot discharge flow passage R3, the first pilot load flow passage A3, and the second pilot load flow passage B3 have an opening to the upper surface of the throttle valve body 13 and a pilot supply flow passage P1 of the pilot valve 1. , The first pilot load flow passage A1, the second pilot load flow passage B1, and the pilot discharge flow passage R1, respectively, and the opening to the lower surface of the throttle valve body 13 is connected to the pilot supply flow passage P3 of the main valve 2 and the pilot discharge flow passage. The flow path R2, the first pilot load flow path A2, and the second pilot load flow path B2 are respectively connected.

The throttle valve main body 13 is connected to the first pilot load flow passage A3 and is connected to the second pilot load flow passage B3 and the bottomed first mounting hole 14A which is opened on one side surface of the throttle valve main body 13. A second bottomed storage hole 14B is formed in the other side surface of the throttle valve body 13 that faces the one side surface, and a bottomed second storage hole 14A is formed in the first cover member 15A. The openings of 14B are closed by the second lid member 15B. The first check valve body 16A and the first throttle valve body 17A are housed in the first storage hole 14A, and the second check valve body 16B and the second throttle valve body 17B are stored in the second storage hole 14B. And are housed. The first non-return valve body 16A has a cylindrical shape and has a throttle hole 18A formed through it in the radial direction, and is provided so as to be freely seated and detachable on a valve seat 19A formed in the first housing hole 14A. The first check valve body 16A separates the flow of the pilot fluid from the first pilot load passage A1 of the pilot valve 1 toward the first pilot load passage A2 of the main valve 2 from the valve seat 19A. The flow of the pilot fluid from the first pilot load flow passage A2 of the main valve 2 to the first pilot load flow passage A1 of the pilot valve 1 is seated on the valve seat 19A and flows through the throttle hole 18A while allowing free flow. It is a control flow. Similarly, the second non-return valve body 16B has a cylindrical shape and has a throttle hole 18B formed therethrough. The second non-return valve body 16B is detachably mounted on the valve seat 19B of the second storage hole 14B so as to be detachable from the second pilot load passage of the pilot valve 1. The flow of the pilot fluid from B1 toward the second pilot load flow passage B2 of the main valve 2 is separated from the valve seat 19B to be a free flow, and at the same time, from the second pilot load flow passage B2 of the main valve 2 to the pilot valve 1 The flow of the pilot fluid toward the second pilot load flow path B1 is a control flow in which the valve seat 19B is seated and the throttle hole 18B is caused to flow.

The first throttle valve body 17A is screwed to the first lid member 15A and fitted to the first check valve body 16A, and the opening degree of the throttle hole 18A is set to be adjustable by advancing and retreating by a rotating operation. .. Further, the first throttle valve body 17A is provided with an abutting portion 20A at the tip in the axial direction, and the abutting portion 20A abuts the bottom surface of the first housing hole 14A to regulate the axial movement amount and to be screwed into the lock. 21 A of nut members contact|abut on the outer surface of 15 A of 1st lid members, and are fixed. The second throttle valve body 17B is screwed to the second lid member 15B and fitted into the second check valve body 16B, and the opening degree of the throttle hole 18B is set to be adjustable by advancing and retracting by a turning operation. .. In addition, the second throttle valve body 17B is provided with an abutting portion 20B at the tip in the axial direction, and the abutting portion 20B abuts the bottom surface of the second housing hole 14B to regulate the axial movement amount and to be screwed into the lock. The nut member 21B is brought into contact with and fixed to the outer surface of the first lid member 15B.

Next, the operation of such a configuration will be described.
1 and 2, in the pilot valve 1, the electromagnets 4A and 4B are not excited, the pilot valve body 5 is held at the neutral position Z1 by the force of the springs 6A and 6B, and the pilot supply passage P1 is shut off. The pilot load flow passage A1 and the second pilot load flow passage B1 communicate with the pilot discharge flow passage R1. The main valve 2, both working chambers 9A, 9B communicates with the tank T, a main valve body 8 is held in a neutral position Z by the spring 10 A, 10 B forces, blocking the main supply passage P2, the first main The load flow passage A and the second main load flow passage B communicate with the main discharge flow passage R.

When one of the electromagnets 4A is excited in this state, the pilot valve body 5 switches to the first switching position X1 against the force of the spring 6B, and the pilot pressure fluid in the pilot supply passage P1 becomes the second pilot load passage B1. As a result, it flows through the second check valve body 16B of the throttle valve 3 in a free flow and is introduced into the second working chamber 9B via the second pilot load flow paths B3 and B2. The main valve body 8 slides leftward in FIG. 1 against the force of the spring 10A by the action force based on the pressure of the pilot fluid introduced into the second action chamber 9B. At this time, the pilot fluid in the first working chamber 9A is controlled to flow from the first pilot load passage A2 through the throttle hole 18A of the first check valve body 16A which is seated on the valve seat 19A of the throttle valve 3 and closed. After passing through the first pilot load flow paths A3 and A1, the flow is led out to the tank T from the pilot discharge flow paths R1, R3 and R2. Therefore, the main valve body 8 slides at a slow speed by the control flow in the throttle hole 18A and switches to the second switching position Y.

In a state where the main valve body 8 is switched to the second switching position Y, the first main load flow passage A is switched and communicated with the main supply flow passage P2, and the second main load flow passage B is connected to the main discharge flow passage R. Switch communication. The pressure fluid in the main supply passage P2 is supplied to the actuator (not shown) from the first main load passage A, and the fluid from the actuator flows in the second main load passage B to control the meter-out by the taper portion 8BB of the main valve body 8. It is controlled to be throttled by and is discharged to the tank T from the main discharge passage R.

When the electromagnet 4A of the pilot valve 1 is de-energized in this state, the pilot valve 1 returns to the neutral position Z1 and the second working chamber 9B of the main valve 2 is switched to the tank T for communication. The main valve body 8 slides back to the right in FIG. 1 by the force of the spring 10A, and the pilot fluid in the second working chamber 9B is seated on the valve seat 19B of the throttle valve 3 and is closed. It flows in a controlled flow through the throttle hole 18B of 16B and is led to the tank T. Therefore, the main valve body 8 slides at a slow speed by the control flow in the throttle hole 18B and returns to the neutral position Z.

When the pilot valve 1 is in the neutral position Z 1 and the other electromagnet 4B is excited, the pilot valve body 5 switches to the second switching position Y1 against the force of the spring 6A, and the pilot of the pilot supply flow path P1. The pressure fluid flows from the first pilot load flow passage A1 through the first check valve body 16A as a free flow, is introduced into the first working chamber 9A via the first pilot load flow passages A3 and A2, and the main valve body 8 is The action force based on the pressure of the pilot fluid in the first action chamber 9A slides to the right in FIG. 1 against the force of the spring 10B. At this time, the pilot fluid in the first working chamber 9B flows from the second pilot load flow passage B2 through the throttle hole 18B of the second check valve body 16B, which is seated on the valve seat 19B and closed, in a control flow, It is led to the tank T from the pilot discharge flow path R1 through the pilot load flow paths B3 and B1. Therefore, the main valve body 8 slides at a slow speed by the control flow in the throttle hole 18B and switches to the first switching position X.

In a state where the main valve body 8 is switched to the first switching position X, the first main load passage A is switched to the main discharge passage R and the second main load passage B is connected to the main supply passage P2. Switch communication. The pressure fluid in the main supply passage P2 is supplied from the second main load passage B to an actuator (not shown), and the fluid from the actuator flows in the first main load passage A and is metered out by the taper portion 8AA of the main valve body 8. It is controlled to be throttled by and is discharged to the tank T from the main discharge passage R.

When the electromagnet 4B of the pilot valve 1 is de-excited, the pilot valve 1 returns to the neutral position Z1 and the first working chamber 9A of the main valve 2 is switched and communicated with the tank T. The main valve body 8 returns slid to the left in FIG. 1 by the spring 10B forces, pilot fluid in the first working chamber 9A is squeezed in the first check valve body 16A is closed and seated on the valve seat 19 A It flows through the hole 18A in a controlled flow and is led to the tank T. Therefore, the main valve body 8 slides at a slow speed by the control flow in the throttle hole 18A and returns to the neutral position Z.

With such operation, when the main valve 2 is switched from the neutral position X to the first switching position Y or the second switching position Z, the pilot flowing through the first pilot load passage A3 or the second pilot load passage B3 by the throttle valve 3 The fluid is throttle-controlled, and the taper portion 8AA or 8BB provided in the main valve body 8 throttle-controls the fluid flowing from the first main load passage A or the second main load passage B to the main discharge passage R. Therefore, the switching speed of the main valve body 8 can be moderated by the throttle control of the pilot fluid by the throttle valve 3, and the taper portion 8AA or 8BB allows the first main load passage A or the first main load passage A in the transitional transition period of the main valve body 8 to be switched. 2 Since the flow velocity of the fluid flowing from the main load flow passage B to the main discharge flow passage R can be made gentle, the switching shock of the main valve 2 can be reduced.

The main valve 2, the pilot valve 1, and the throttle valve 3 are formed by sequentially stacking the throttle valve 3 and the pilot valve 1 with the main valve 2 at the bottom. Therefore, the main valve 2, the pilot valve 1, and the throttle valve 3 can be individually replaced, and can be easily changed according to the application.

6 and 7 show another embodiment of the present invention. The same parts as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.
The first land 8A of the main valve body 8 is formed with a tapered portion 8CC as a throttle portion on the inner side in the axial direction, and the tapered portion 8CC is gradually reduced in diameter toward the inner side in the axial direction, so that the neutral position Z changes to the second switching position. During the transitional transition period when switching to Y, the fluid flowing from the main supply passage P2 to the first main load passage A is throttle-controlled to gradually increase the flow rate of the main supply passage P2 to the first main load passage A. The second land 8B of the main valve body 8 is formed with a tapered portion 8DD as a throttle portion on the inner side in the axial direction, and the tapered portion 8DD is gradually reduced in diameter toward the inner side in the axial direction, so that the neutral position Z changes to the first switching position. During the transitional period of switching to X, the fluid flowing from the main supply passage P2 to the second main load passage B is throttle-controlled to gradually increase the flow rate of the main supply passage P2 to the second main load passage B. The taper portion 8CC performs the meter-in control at the second switching position Y and the taper portion 8DD performs the meter-in control at the first switching position X, respectively.

In operation, when one electromagnet 4A is excited with the pilot valve 1 in the neutral position Z1, the pilot valve 1 switches to the first switching position X1 and introduces the pilot fluid into the second working chamber 9B of the main valve 2. .. The main valve 2 is switched to the second switching position Y by introducing the pilot fluid into the second working chamber 9B to switch the first main load passage A to the main supply passage P2 and to communicate with the second main load passage. B is switched and communicated with the main discharge flow path R. The pressure fluid in the main supply passage P2 is throttle-controlled by meter-in control by the taper portion 8CC of the main valve body 8 and is supplied to the actuator (not shown) from the first main load passage A, and the fluid from the actuator is the second main load flow. It flows through the path B and is discharged from the main discharge flow path R to the tank T. When one of the electromagnets 4A is de-excited, the pilot valve 1 returns to the neutral position Z1, the second working chamber 9B of the main valve 2 is switched and communicated with the tank T, and the main valve 2 is neutralized by the force of the spring 10A. Return to position Z.

When the other electromagnet 4B is excited while the pilot valve 1 is in the neutral position Z1, the pilot valve 1 switches to the second switching position Y1 and introduces the pilot fluid into the first working chamber 9A of the main valve 2. The main valve 2 is switched to the first switching position X by the introduction of the pilot fluid into the first working chamber 9A, the first main load passage A is switched to the main discharge passage R, and the second main load passage is connected. B is switched and communicated with the main supply flow path P2. The pressure fluid in the main supply passage P2 is throttle-controlled by meter-in control by the taper portion 8DD of the main valve body 8 and is supplied to the actuator (not shown) from the second main load passage B, and the fluid from the actuator is the first main load flow. It flows through the path A and is discharged to the tank T from the main discharge flow path R. Then, when the other electromagnet 4B is de-excited, the pilot valve 1 returns to the neutral position Z1, and the first working chamber 9A of the main valve 2 is switched and communicated with the tank T, and the main valve 2 is neutralized by the force of the spring 10B. Return to position Z.

With such operation, when the main valve 2 is switched from the neutral position X to the first switching position Y or the second switching position Z, the pilot flowing through the first pilot load passage A3 or the second pilot load passage B3 by the throttle valve 3 The fluid is throttle-controlled, and the taper portion 8CC or 8DD provided in the main valve body 8 throttle-controls the fluid flowing from the main supply passage P2 to the first main load passage A or the second main load passage B. For this reason, the switching speed of the main valve body 8 can be made slower by the throttle control of the pilot fluid by the throttle valve 3, and the taper portion 8CC or 8DD allows the main supply passage P2 to flow from the main supply passage P2 in the transitional transition period of the main valve body 8. Since the flow velocity of the fluid flowing through the load passage A or the second main load passage B can be made gentle, the switching shock of the main valve 2 can be reduced.

Further, as in the case of the one embodiment, the main valve 2 is located at the lowermost position and the throttle valve 3 and the pilot valve 1 are sequentially stacked. Therefore, the main valve 2, the pilot valve 1 and the throttle valve 3 are individually provided. It can be replaced and can be easily changed according to the application.

In addition, in each of the above-described embodiments, the tapered portions 8AA, 8BB, 8CC, and 8DD are formed on the lands 8A and 8B of the main valve body 8 as the throttle portions. However, the present invention is not limited to this and the lands 8A and 8B are Grooves or notches may be formed. Further, although the main valve 2, the pilot valve 1 and the throttle valve 3 are arranged in a laminated manner, it goes without saying that the main valve, the pilot valve and the throttle valve may be arranged in one valve body.

1: Pilot valve 2: Main valve 3: Throttle valve 4A, 4B: Electromagnet
5: Pilot valve body 8: Main valve body 8AA, 8BB, 8CC, 8DD: Taper part (throttle part)
9A: First working chamber 9B: Second working chamber P2: Main supply flow path A: First main load flow path B: Second main load flow path R: Main discharge flow path P1: Pilot supply flow path A1: First Pilot load flow path B1: Second pilot load flow path R1: Pilot discharge flow path X, X1: First switching position Y, Y1: Second switching position Z, Z1: Neutral position P: Pressure source T: Tank (low pressure side )

Claims (3)

A pilot valve that operates the pilot valve body by exciting or de-exciting the electromagnet to switch the pilot flow path, and a main valve that operates the main valve body by the action or non-action of the pilot fluid flowing in the pilot flow path to switch the main flow path. And a throttle valve for restricting control of the pilot fluid flowing through the pilot flow passage, and a main valve body of the main valve is provided with a throttle portion for restricting control of the fluid flowing through the main flow passage. A pilot supply flow path for supplying a pilot pressure fluid from a pressure source, a first pilot load flow path, a second pilot load flow path, and a pilot discharge flow path connected to the low pressure side. A first switching position for switching and communicating the flow passage to the pilot discharge flow passage and switching and communicating the second pilot load flow passage to the pilot supply flow passage; and a first switching position for switching and communicating the first pilot load flow passage to the pilot supply flow passage. The throttle valve has three positions, a second switching position for switching and communicating the two pilot load flow paths to the pilot discharge flow path, and a neutral position. The throttle valve is a unidirectional flow of the pilot fluid flowing through the first pilot load flow path. A first non-return valve body having a cylindrical shape that separates the valve from the valve seat to make it a free flow, and controls the flow of the pilot fluid in the other direction to sit on the valve seat and make the control flow to flow through the throttle hole; A first throttle valve body that is fitted to the stop valve body and that adjusts the opening degree of the throttle hole formed in the first check valve body by advancing and retracting by a turning operation, and a pilot that flows through the second pilot load flow path. Cylindrical second non-return valve that allows the flow of fluid in one direction to separate from the valve seat to be a free flow, and allows the flow of pilot fluid in the other direction to sit on the valve seat and flow through the throttle hole as a control flow A valve body and a second throttle valve body which is fitted to the second check valve body and which adjustably sets the opening degree of a throttle hole formed in the second check valve body by advancing and retracting by a turning operation, An abutting portion that comes into contact with the first throttle valve body and the second throttle valve body to regulate the axial movement amount is provided at the axial tip end, and the main valve uses a main flow path to supply a pressure fluid from a pressure source. It comprises a supply flow path, a first main load flow path connected to the load side, a second main load flow path, and a main discharge flow path connected to the low pressure side. The first main load flow path is used as the main discharge flow path. A first switching position for switching and communicating the second main load flow path with the main supply flow path; and a first switching path for communicating the first load flow path with the main supply flow path and the second main load flow path for main discharge flow. The first working chamber and the second working chamber, which have three positions, that is, a second switching position for switching and communicating with the passage and a neutral position, and which introduces a pilot fluid that acts on the main valve body, serve as a first pilot load flow path. Second pilot negative The main valve body is switched to the first switching position by introducing the pilot fluid into the first working chamber, and the main valve body is switched to the second switching position by introducing the pilot fluid into the second working chamber. The main valve body is set to the neutral position by drawing the pilot fluid from both working chambers, and the maximum axial movement amount of the main valve body is regulated. A screw member that sets the maximum flow rate flowing in the load passage is provided so that the throttle portion switches the main valve body from the neutral position to the first switching position or the second switching position. Alternatively, a pilot type solenoid valve is characterized in that the fluid flowing from the second main load passage to the main discharge passage is throttled. A pilot valve that operates the pilot valve body by exciting or de-exciting the electromagnet to switch the pilot flow path, and a main valve that operates the main valve body by the action or non-action of the pilot fluid flowing in the pilot flow path to switch the main flow path. And a throttle valve for restricting control of the pilot fluid flowing through the pilot flow passage, and a main valve body of the main valve is provided with a throttle portion for restricting control of the fluid flowing through the main flow passage. A pilot supply flow path for supplying a pilot pressure fluid from a pressure source, a first pilot load flow path, a second pilot load flow path, and a pilot discharge flow path connected to the low pressure side. A first switching position for switching and communicating the flow passage to the pilot discharge flow passage and switching and communicating the second pilot load flow passage to the pilot supply flow passage; and a first switching position for switching and communicating the first pilot load flow passage to the pilot supply flow passage. The throttle valve has three positions, a second switching position for switching and communicating the two pilot load flow paths to the pilot discharge flow path, and a neutral position. The throttle valve is a unidirectional flow of the pilot fluid flowing through the first pilot load flow path. A first non-return valve body having a cylindrical shape that separates the valve from the valve seat to make it a free flow, and controls the flow of the pilot fluid in the other direction to sit on the valve seat and make the control flow to flow through the throttle hole; A first throttle valve body that is fitted to the stop valve body and that adjusts the opening degree of the throttle hole formed in the first check valve body by advancing and retracting by a turning operation, and a pilot that flows through the second pilot load flow path. Cylindrical second non-return valve that allows the flow of fluid in one direction to separate from the valve seat to be a free flow, and allows the flow of pilot fluid in the other direction to sit on the valve seat and flow through the throttle hole as a control flow A valve body and a second throttle valve body which is fitted to the second check valve body and which adjustably sets the opening degree of a throttle hole formed in the second check valve body by advancing and retracting by a turning operation, An abutting portion that comes into contact with the first throttle valve body and the second throttle valve body to regulate the axial movement amount is provided at the axial tip end, and the main valve uses a main flow path to supply a pressure fluid from a pressure source. It comprises a supply flow path, a first main load flow path connected to the load side, a second main load flow path, and a main discharge flow path connected to the low pressure side. The first main load flow path is used as the main discharge flow path. A first switching position for switching and communicating the second main load flow path with the main supply flow path; and a first switching path for communicating the first load flow path with the main supply flow path and the second main load flow path for main discharge flow. The first working chamber and the second working chamber, which have three positions, that is, a second switching position for switching and communicating with the passage and a neutral position, and which introduces a pilot fluid that acts on the main valve body, serve as a first pilot load flow path. Second pilot negative The main valve body is switched to the first switching position by introducing the pilot fluid into the first working chamber, and the main valve body is switched to the second switching position by introducing the pilot fluid into the second working chamber. The main valve body is set to the neutral position by drawing the pilot fluid from both working chambers, and the maximum axial movement amount of the main valve body is regulated. A screw member that sets the maximum flow rate flowing in the load flow passage is provided so that it can be freely changed, and the throttle portion changes from the main supply flow passage to the first feed position during the transition transition period when the main valve body is switched from the neutral position to the first switching position or the second switching position. A pilot-type solenoid valve which controls the flow of a fluid flowing through a first main load passage or a second main load passage. 3. The pilot type according to claim 1, wherein the main valve, the pilot valve, and the throttle valve are arranged such that the main valve is located at a lowermost position and the throttle valve and the pilot valve are sequentially stacked. solenoid valve.

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