JP3408637B2 - Poppet type directional 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 solenoid operated poppet type directional control valve, and more particularly to a solenoid operated two position directional control valve having three ports.

[0002]

2. Description of the Related Art Switching for switching the flow of a fluid to a fluid supply path connecting a fluid pressure supply source for supplying a fluid such as compressed air, pressurized liquid or negative pressure air and a fluid pressure operating device operated by these fluids. By providing the valve, the operation of the fluid pressure operated device is controlled.

For example, the fluid pressure circuit shown in FIG. 1 (a) is an air supply path connecting an air pressure supply source 1a and a single-acting cylinder 2a as a fluid pressure operation device operated by compressed air supplied from the air pressure supply source 1a. 3a, and a switching valve 4a is provided in the air supply passage 3a. The switching valve 4a is provided when the solenoid is not energized.
It is a normally closed type in which a is closed.

FIG. 1 (b) shows a fluid pressure circuit for supplying a pressurized liquid from a chemical liquid supply source 1b to a chemical liquid coating nozzle 2b via a chemical liquid supply passage 3b, and to this chemical liquid supply passage 3b. The provided switching valve 4b is a normally open type,
When the solenoid of the switching valve 4b is not energized, the chemical liquid supply passage 3b is opened and the chemical liquid is applied from the chemical liquid application nozzle 2b.

FIG. 1 (c) is a diagram showing a fluid pressure circuit having a negative pressure supply source 1c, a vacuum cup 2c, and a negative pressure supply passage 3c connecting them, and the negative pressure supply passage 3c is of a normally closed type. When the switching valve 4c is provided and the switching valve 4c is not energized, the negative pressure supply passage 3c is closed. When a work (not shown) is brought into contact with the vacuum cup 2c and the solenoid is energized, the work is attracted to the vacuum cup 2c in the negative pressure state.

As shown in FIG. 1 (a), a poppet type directional control valve of the type in which the pressure of the fluid acting on the valve body of the normally closed switching valve 4a is balanced is as follows.
For example, there is one as shown in Japanese Patent Publication No. 5-43914. In the switching valve described in this publication, a valve chamber communicating with the input port is formed by a valve body and a diaphragm, and the pressure receiving area of the valve body and the pressure receiving area of the diaphragm are made equal to act on the valve body. I try to balance the power to do it.

[0007]

However, in order to be applicable to both the case of controlling the positive pressure and the case of controlling the negative pressure by using the switching valve having the same structure, the positive valve used is used. The pressure has a large pressure difference with respect to the atmospheric pressure, but when it is used to control the negative pressure, the negative pressure has less pressure difference than the atmospheric pressure, so the pressure of the fluid acting on the valve body Even if the balance is changed, it is not necessary to increase the plunger attraction force of the solenoid.

In general, a negative pressure, that is, a vacuum switching valve is required to have a high sealing property. Therefore, by increasing the diaphragm pressure receiving diameter on the negative pressure side and intentionally breaking the balance of the main shaft, the self-sealing property is improved and stable switching is performed. It can be carried out. Therefore, the switching valve described in the above publication cannot smoothly perform both positive pressure fluid switching control and negative pressure fluid switching control with a small spindle driving force.

An object of the present invention is to switch the flow of fluid by minimizing the main shaft driving force required for switching the valve regardless of whether the flow of positive pressure is switched or controlled to switch the flow of negative pressure. To be able to do it.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0011]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the poppet type directional control valve of the present invention has a valve housing formed with a valve hole in which a valve shaft is movably mounted in the axial direction, and this valve housing has a device communicating with the valve hole. A connection port, a normally open side port connected to the valve hole via the first valve chamber, and a normally closed side port connected to the valve hole via the second valve chamber are formed. The first on one end of the valve stem
A first poppet valve that opens and closes the valve seat and a first diaphragm that partitions the first valve chamber are provided, and a second poppet valve that opens and closes the second valve seat and a second diaphragm that partitions the second valve seat are provided at the other end. A diaphragm is provided. A negative pressure receiving area setting inner peripheral surface is provided on the inner side of each diaphragm, and a positive pressure receiving area setting inner peripheral surface is provided on the outer side thereof. The inner diameter of each negative pressure receiving area setting inner peripheral surface is formed larger than the inner diameter of each positive pressure receiving area setting ring.

The inner diameter of the valve hole is S, the outer diameter of the valve shaft in each valve chamber is T, the inner diameter of the positive pressure receiving area setting inner peripheral surface is d, and the negative pressure receiving area setting inner peripheral surface is d. Letting D be the inner diameter of each, the respective diameters are set so that D>d>S> T.

[0014]

With the above-mentioned structure, the valve shaft acts axially on each diaphragm and poppet valve regardless of whether the positive pressure fluid is supplied to the normally open port or the normally closed port. Since no such pressure is applied, the valve shaft can be smoothly operated by energizing the solenoid even if a high positive pressure fluid is supplied, and the valve shaft can be operated with a small thrust.

On the other hand, regardless of whether the negative pressure fluid is supplied to the normally open side port or the normally closed side port, the atmospheric pressure is applied to the respective diaphragms in a wider area as compared with the case of positive pressure. Acts to act as a thrust in the direction of bringing the poppet valve into close contact with the valve seat, and the close contact force can be secured.
Moreover, when negative pressure is used, the difference from the atmospheric pressure is smaller than when positive pressure fluid is used, so the thrust when operating the valve shaft with a solenoid is reduced to stabilize. The seat force of the poppet valve seat can be secured.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 is a view showing a poppet type directional control valve which is an embodiment of the present invention. The switching valve 10 has a solenoid portion 11 and a valve housing 12, and the valve housing 12 is composed of a central portion 13 and a cap portion 14. A valve hole 15 is formed in the valve housing 12, a first valve seat 16 is formed at one end of the valve hole 15, and a second valve seat 17 is formed at the other end.

The valve housing 12 is formed with a device connection port 18 to which fluid pressure actuated devices such as the cylinder 2a, the chemical solution coating nozzle 2b and the vacuum cup 2c shown in FIG. 1 are connected. Is opened in the valve hole 15 at the inner peripheral wall thereof.

A first valve chamber 21 communicating with the valve hole 15 is formed in the valve housing 12 so as to be positioned on the first valve seat 16 side, and a second valve chamber 22 communicating with the valve hole 15 is formed into a second valve chamber 22. Valve seat 1
It is formed so as to be located on the 7 side. The normally open port 23 is in communication with the first valve chamber 21, and the normally closed port 24 is in communication with the second valve chamber 22.

In the valve hole 15, a valve shaft 25, that is, a valve driving main shaft is mounted so as to be slidable in the axial direction.
5 is formed by the first valve shaft portion 26 and the second valve shaft portion 27. The valve shaft 25 is formed by fitting the fitting protrusion 27a formed in the second valve shaft portion 27 into the fitting hole 26a formed in the first valve shaft portion 26. However, both valve shaft portions 26 and 27 may be screwed to each other.

A compression coil spring 28 is mounted between the cap portion 14 and the valve shaft 25, and the spring 28 causes the valve shaft 25 to move in the direction toward one end thereof, that is, toward the solenoid portion 11. Spring force is biased.

The valve shaft 25 has a first valve chamber 21 and a second valve chamber 22.
The annular protrusions 26b and 27b are formed at the respective positions, and the first poppet valve 31 and the second poppet valve 32 are formed by coating the protrusions 26b and 27b with a rubber layer. There is. Therefore, when the solenoid portion 11 does not operate, the valve shaft 25 moves toward the solenoid portion 11 side by the spring 28 and the second poppet valve 3
2 contacts the valve seat 17, and the communication between the normally closed port 24 and the valve hole 15 is closed. At this time, the first poppet valve 3
1 is away from the valve seat 16 and the normally open port 23 and the valve hole 15 are in communication with each other.

On the other hand, when the solenoid 11 is operated,
The valve shaft 25 moves toward the cap portion 14 side against the spring force of the spring 28, whereby the first poppet valve 3
1 contacts the first valve seat 16 to close the normally open side port 23, and at the same time, the second poppet valve 32 separates from the second valve seat 17 to open the normally closed side port 24.

A first diaphragm 33 made of rubber is provided on the solenoid portion 11 side of the valve shaft 25, and the diaphragm 33 is formed integrally with the first poppet valve 31. A second diaphragm 34 made of rubber is provided on the valve shaft 25 on the side of the cap portion 14, and the diaphragm 34 is formed integrally with the second poppet valve 32. Each poppet valve 31, 32 and diaphragm 3
The part connecting the valve shafts 3 and 34 has a cylindrical shape and constitutes a part of the valve shaft 25.
It is exposed in 2. The exposed portion is the outer peripheral surface of the valve shaft 25.

The first diaphragm 33 defines the inner first valve chamber 21 and the outer atmospheric pressure chamber 35, and the atmospheric pressure chamber 35 is communicated to the outside by a flow path (not shown). Further, the second diaphragm 34 partitions the second valve chamber 22 on the inner side and the atmospheric pressure chamber 36 on the outer side, and the atmospheric pressure chamber 36 is communicated to the outside by a flow path 37 formed in the cap portion 14. There is.

In the case shown in the drawing, a negative pressure receiving area setting ring 41 is detachably provided in the valve housing 12 inside the first diaphragm 33, and the inner peripheral surface thereof is a negative pressure receiving area setting inner peripheral surface. 41a. A negative pressure receiving area setting ring 42 is detachably provided inside the second diaphragm 34, and an inner peripheral surface thereof serves as a negative pressure receiving area setting inner peripheral surface 42a. However,
The portions of these rings 41 and 42 may be formed integrally with the valve housing 12.

A positive pressure pressure receiving area setting ring 43 is detachably provided on the valve housing 12 outside the first diaphragm 33, and a positive pressure receiving area setting ring is positioned outside the second diaphragm 34. 44 are detachably provided, and the inner peripheral surfaces of the rings 43 and 44 are positive pressure receiving area setting inner peripheral surfaces 43a and 44a.

Each negative pressure receiving area setting ring 4
The inner diameter of 1, 42 is φD, the inner diameter of each positive pressure receiving area setting ring 43, 44 is φd, the inner diameter of the valve hole 15 is φS, and the outer diameter of the valve shaft 25 in the valve chamber 21, 22 is φT. Then, these dimensions are set to have a relationship of D>d>S> T.

The solenoid portion 11 has a bobbin 52 around which a coil 51 is wound, a fixed core 53 is attached inside the tip of the bobbin 52, and a movable core 54 is axially slid at the rear end of the bobbin 52. It is movably installed. The movable core 54 is provided with an operating rod 55 penetrating the fixed core 53, and the operating rod 55 causes the valve shaft 25 to move.
Are being driven.

When the switching valve 10 shown in FIG. 2 is used as the switching valve 4a shown in FIG. 1 (a) and the compressed air from the air pressure source 1a is supplied to the single-acting cylinder 2a, The equipment connection port 18 is connected to the cylinder 2a, and the normally closed port 24 is connected to the air pressure supply source 1a via the air supply passage 3a. When the coil 51 of the solenoid portion 11 is energized when driving the piston in the cylinder 2a, the valve shaft 25 is driven toward the cap portion 14 side, the second poppet valve 32 separates from the second valve seat 17, and 1
The poppet valve 31 contacts the first valve seat 16. As a result, compressed air from the air pressure supply source 1a is supplied into the cylinder 2a via the valve hole 15 and the device connection port 18.

On the other hand, when the energization is released, the second valve seat 17 is closed by the second poppet valve 32, and the first poppet valve 31 is separated from the first valve seat 16, so that the fluid in the cylinder 2a is in the normally open port 23. It is discharged to the outside via.

When the coil 51 is energized to drive the valve shaft 25, the air pressure supplied to the normally closed port 24 acts in the second valve chamber 22. The fluid pressure in the second valve chamber 22 that is biased in the direction is set by the area acting on the second diaphragm 34 and the area acting on the second valve seat 16 by the second poppet valve 32.
Since the area acting on the second diaphragm 34 is set by the inner peripheral surface 44a of the positive pressure receiving area setting ring 44, the force acting on the valve shaft 25 by the fluid pressure is balanced to the normally closed port 24. The fluid in the second valve chamber 22 is not affected by any applied pressure of the second poppet valve 3
It is possible to reduce the thrust acting on the second valve seat 17 in the direction away from the second valve seat 17 and to sufficiently secure the closing force of the second poppet valve 32. Thereby, in order to operate the valve shaft 25,
It suffices to apply a thrust force that can actuate the valve shaft 25 against the biasing force of the spring 28.
It is possible to switch and control the flow of a large volume of fluid without causing a large current to flow through the unit 1.

This also applies to the case where the switching valve 10 shown in FIG. 2 is used as the switching valve 4b for controlling the flow of the chemical liquid, as shown in FIG. 1 (b). In that case, the chemical solution supply source 1b may be connected to the normally open port 23 or the normally closed port 24.

Further, the switching valve 10 shown in FIG. 2 is shown in FIG.
When it is used to control the operation of the vacuum cup 1c as shown in (1), for example, the negative pressure supply source 1c is connected to the normally closed port 24. In this case, with the second poppet valve 32 closing the second valve seat 17, the atmospheric pressure chamber 3
Since the atmosphere of 6 acts on the second diaphragm 34 in the range of the diameter φD, the negative pressure in the second valve chamber 22 additionally acts in the direction of closing the second poppet valve 32.

Since the negative pressure used has a smaller difference from the atmospheric pressure than the case where positive pressure is used, the second poppet valve 32 is used.
The negative pressure in the second valve chamber 22 acts in the direction of pressing the second poppet valve 32 against the second valve seat 17 without increasing the thrust for driving the valve shaft 25 to open the valve shaft 25. Leakage of compressed air can be prevented. This also applies to the case where the switching valve is used by connecting the negative pressure supply source 1c to the normally open port 23.

Although the invention made by the present inventor has been concretely described above based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

[0037]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

(1) Regardless of whether positive pressure fluid or negative pressure fluid is used by the switching valves of the same structure,
It is possible to reliably switch the flow path.

(2) Further, regardless of whether a positive pressure fluid or a negative pressure fluid is used, the valve shaft will not move even if the inner diameter of the shaft hole is increased to flow a large volume of fluid. It can be operated with a small thrust.

[Brief description of drawings]

FIG. 1A to FIG. 1C are fluid pressure circuit diagrams each showing a connection state between a fluid pressure operating device and a fluid pressure source.

FIG. 2 is a sectional view showing a poppet type directional control valve which is one embodiment of the present invention.

[Explanation of symbols]

1a Air pressure supply source (fluid pressure supply source) 1b Chemical liquid supply source (fluid pressure supply source) 1c Negative pressure supply source (fluid pressure supply source) 2a Cylinder (fluid pressure operation device) 2b Chemical coating nozzle (fluid pressure actuation device) 2c Vacuum cup (fluid pressure actuated device) 3a Air supply path (fluid supply path) 3b Chemical liquid supply path (fluid supply path) 3c Negative pressure supply path (fluid supply path) 4a, 4b, 4c switching valve 10 switching valve 11 Solenoid part 12 valve housing 13 Central part 14 Cap section 15 valve holes 16 First valve seat 17 Second valve seat 18 Device connection port 21 First valve chamber 22 Second valve chamber 23 Normally open port 24 Normally closed port 25 valve shaft 26 First valve shaft 27 Second valve shaft 28 springs 31 First Poppet Valve 32 Second Poppet Valve 33 First diaphragm 34 Second diaphragm 35,36 Atmospheric chamber 37 channels 41,42 Negative pressure receiving area setting ring 43,44 Positive pressure receiving area setting ring 51 coils 52 Bobbin 53 fixed core 54 Movable core 55 Working rod

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 57-110876 (JP, A) JP 6-221464 (JP, A) JP 50-135444 (JP, A) SAIKAI HEI 3- 175 (JP, U) Actual Kaihei 6-49872 (JP, U) Japanese Patent Publication 5-43914 (JP, B2) Japanese Patent Publication Sho 31-8953 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 11/04 F16K 31/06

Claims (3)

(57) [Claims] 1. A valve hole, a device connection port that communicates with the valve hole and is connected to a fluid pressure actuating device, a normally-open port that can communicate with the valve hole via a first valve chamber, and the valve hole. A valve housing having a normally-closed side port that can communicate with each other through a second valve chamber, and a first valve seat that opens and closes a first valve seat formed at one end of the valve hole.
A poppet valve and a second poppet valve that opens and closes a second valve seat formed at the other end of the valve hole, the valve shaft being axially movably mounted in the valve hole; A solenoid portion that operates the valve shaft in a direction that closes the first poppet valve and opens the second poppet valve against a spring force biased to open the poppet valve and close the second poppet valve; A first diaphragm and a second diaphragm, which are respectively provided at both ends of the valve shaft, partition the first valve chamber and partition the second valve chamber, and are formed inside the respective first and second diaphragms. A negative pressure receiving area setting inner peripheral surface and a positive pressure receiving area setting inner peripheral surface formed outside the respective first and second diaphragms. Inner diameter of each of the above The poppet type directional control valve, characterized in that formed larger than the inner diameter of the pressure receiving area set circumference. 2. The inner diameter of the valve hole is S, the outer diameter of the valve shaft in each of the valve chambers is T, the inner diameter of each positive pressure receiving area setting inner circumferential surface is d, and each negative pressure receiving area. When the inner diameter of the set inner peripheral surface is D, D>d>S>
The poppet type directional control valve according to claim 1, wherein the respective diameters are set so as to be T. 3. The negative pressure receiving area setting inner peripheral surface and the positive pressure receiving area setting inner peripheral surface are each formed by a ring, and are exchangeably attached to those having different inner diameters. The poppet type directional control valve according to claim 1 or 2, characterized in that.