JP4025038B2 - solenoid valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic valve, and more particularly to an electromagnetic valve capable of switching and controlling a high-pressure fluid with a small solenoid force.
[0002]
[Prior art]
Conventionally, an electromagnetic valve has been used to switch a fluid flow path. Generally, an electromagnetic valve is composed of a valve seat and a valve portion that opens and closes a flow path by a valve body disposed so as to face the valve seat, and a solenoid portion that drives the valve body with respect to the valve seat.
[0003]
The valve portion includes two ports drilled in the body, a valve seat disposed between the ports and formed integrally with the body, and a valve body that is driven to open and close by the solenoid portion. In addition, the solenoid part can move forward and backward in the axial direction at the axial position of the electromagnetic coil to which a control current is supplied from the outside, a core that functions as a fixed iron core fixed at the axial position of the electromagnetic coil, and the electromagnetic coil. A plunger that functions as a movable iron core disposed and a spring that urges the plunger in the opening or closing direction with respect to the valve body of the valve portion are provided.
[0004]
By the way, the valve body has various shapes, a flat valve that closes the valve seat with a flat surface, a tapered valve that opens and closes by opening and closing a conical shape into the valve hole, and a needle-shaped one as the valve hole A needle valve that opens and closes by opening and closing is known.
[0005]
[Problems to be solved by the invention]
However, if the axial position of the valve seat and the advance / retreat direction of the valve body do not coincide with each other, or if the taper valve or needle valve is slightly inclined with respect to the axial direction of the valve seat, A gap is created and the seal is incomplete. Therefore, there is a problem that fluid leakage may occur in the valve portion.
[0006]
Further, the solenoid valve for switching the high-pressure fluid has a problem that the solenoid part is enlarged because it is necessary to drive the valve element with a solenoid force that is higher than the fluid pressure received by the valve element.
[0007]
The present invention has been made in view of the above points, and can provide a sufficient seal even when seated in a state where the valve body is inclined with respect to the axial direction of the valve seat, and the valve body is driven. An object of the present invention is to provide a solenoid valve that can reduce the size of a solenoid part.
[0008]
[Means for Solving the Problems]
In the present invention, in order to solve the above-described problem, the valve portion that opens and closes the fluid passage by the valve body arranged to face the valve seat and the valve seat, and the relative position of the valve body and the valve seat are changed. In a solenoid valve composed of a solenoid unit to be driven, a valve body having a spherical shape with a surface arranged in the fluid passage in an axial direction and a surface having a spherical shape, and an axial movement in the middle of the fluid passage. A cylindrical plunger in which an opening is formed at a central axis position and an end surface of the opening functions as a valve seat for the valve body; and a first biasing the plunger toward the valve body. A spring, a core fixedly disposed at an axial position opposite to the side on which the valve element is provided with respect to the plunger, a core having a passage formed at a central axial position, and the opening of the plunger; one end A hollow shaft fixed to the passage of the core and having an at least one groove passing through the center on an end surface facing the valve body, and urging the valve body in a direction contacting the end surface of the shaft And a second spring that absorbs an impact of the plunger against the valve body when the valve is closed.
[0009]
According to such an electromagnetic valve, a valve body having a spherical surface that is movable back and forth in the axial direction is used, a cylindrical plunger of a solenoid portion is used as a valve seat, and a spherical valve is formed at an end surface opening of the plunger. I try to sit down. As a result, even if the plunger is seated on the valve body in an inclined state due to the clearance with the sleeve necessary to make the plunger movable, the relative shape between the end face of the plunger and the surface of the valve body is It does not change. For this reason, even if the axis | shaft of a plunger slip | deviates, it will be in the same state as the centering automatically, and a plunger and a valve body can be tightly sealed.
[0010]
Further, in the present invention, a plurality of communication grooves extending in the axial direction are formed in the outer peripheral portion of the plunger, and the inlet side fluid pressure is introduced into the end surface of the plunger on the core side. As a result, the pressure of the fluid introduced to both end faces of the plunger that is the valve seat is equally applied, and the movement of the plunger does not depend on the pressure of the fluid. Therefore, since the plunger can be driven only by the solenoid force, the solenoid force can be reduced and the solenoid portion can be reduced in size.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example a case where the present invention is applied to a two-way solenoid valve.
[0012]
FIG. 1 is a central longitudinal sectional view showing a state when a two-way solenoid valve according to an embodiment of the present invention is not energized, and FIG. 2 shows a state when the two-way solenoid valve according to an embodiment of the present invention is energized. It is a center longitudinal cross-sectional view.
[0013]
The two-way solenoid valve according to the embodiment is composed of a valve portion 1 provided at the lower portion and a solenoid portion 2 provided at the upper portion.
The valve unit 1 includes a body 3 and an inlet port 4 and an outlet port 5 provided on a side surface of the body 3. A case 6 constituting a flow path between the inlet port 4 and the outlet port 5 is press-fitted into the body 3 from the upper opening. The case 6 is formed with an annular fluid introduction groove 7 that communicates with the inlet port 4, and a cylindrical protrusion 8 is provided at the center of the upper portion. This protrusion 8 constitutes the core of a magnetic circuit including an electromagnetic coil 20 described later. In addition, the case 6 is provided with a passage 9 that penetrates the central axis of the protrusion 8 and communicates with the outlet port 5. Separately from the passage 9, the fluid introduction groove 7 extends to the upper end surface of the protrusion 8. A plurality of reaching passages 10 are formed at positions surrounding the passage 9.
[0014]
The solenoid unit 2 includes a sleeve 12 having a lower end fitted to the outer peripheral surface of the protrusion 8 of the case 6. In this sleeve 12, a plunger 13 serving as a movable iron core is fitted and disposed so as to be movable back and forth in the axial direction, and a protrusion 8 of the case 6 constitutes a core that functions as a fixed iron core with respect to this plunger 13. Yes. The plunger 13 has a cylindrical shape in which an opening is formed so as to penetrate the central axis, and a plurality of communication grooves 14 extending in the axial direction are formed on the outer periphery of the plunger 13. A cap 15 is screwed over the sleeve 12.
[0015]
A ball valve body 16 having a spherical surface is disposed between the cap 15 and the plunger 13 so as to be able to advance and retract in the axial direction. The upper end surface of the plunger 13 constitutes a valve seat that opens and closes the flow path by moving toward and away from the ball valve body 16. The plunger 13 has a back pressure canceling structure in which the fluid pressure applied to the surface on the ball valve body 16 side and the surface on the opposite side is equalized by the communication groove 14.
[0016]
The hollow shaft 17 passes through the opening of the plunger 13 and is fixed by being inserted into a passage 9 having a lower end formed at the axial position of the protrusion 8 of the case 6. The upper end of the shaft 17 is reduced in diameter so as to form an annular space with the opening of the plunger 13, and a single groove 17a passing through the center is formed on the end surface. The space 11 on the upper end surface side of the plunger 13 is communicated with the hollow portion of the shaft 17 and the passage 9 on the downstream side through the groove 17a.
[0017]
Between the plunger 13 and the protrusion 8 of the case 6, a spring 18 is disposed that biases the plunger 13 that is a valve seat so that the ball valve body 16 is seated. A spring 19 is disposed between the cap 15 and the ball valve body 16 to urge the ball valve body 16 against the shaft 17 and absorb the impact of the plunger 13 on the ball valve body 16 when the valve is closed. ing.
[0018]
An electromagnetic coil 20 is disposed on the outer periphery of the sleeve 12, and the outer side thereof is surrounded by a yoke 21. The upper end of the yoke 21 is closed by a plate 22 that constitutes a part of the magnetic circuit of the solenoid unit 2. Further, the lower end portion of the yoke 21 constitutes a part of the magnetic circuit of the solenoid portion 2 and is fixed to a flange 23 for attaching the valve portion 1 to the body 3. The electromagnetic coil 20 is connected to a wiring 24 for supplying a control current from the outside to open and close the two-way electromagnetic valve.
[0019]
Here, as shown in FIG. 1, in a state where the solenoid portion 2 is not energized, the plunger 13 is moved upward in the figure by the spring 18 and is urged downward in the figure by the spring 19 on the upper end surface. The ball valve body 16 is seated to close the fluid passage. Here, when high-pressure fluid flows from the inlet port 4, the high-pressure fluid enters the fluid introduction groove 7 of the case 6 and is introduced into the space 11 a below the plunger 13 through the passage 10. The fluid introduced here is further introduced into the space 11 on the upper end surface side of the plunger 13 through a communication groove 14 provided around the plunger 13. As a result, the plunger 13 receives equal fluid pressure from both sides in the axial direction, so that the influence of the pressure from the high pressure fluid on the valve opening / closing operation is eliminated, and the valve closed state can be reliably maintained by the biasing force of the spring 18.
[0020]
Further, since the ball valve body 16 has a spherical surface, the sealing performance with the upper end surface of the plunger 13 that functions as a valve seat can be enhanced. That is, a clearance is provided between the plunger 13 disposed in the sleeve 12 so as to be movable back and forth in the axial direction and the inner wall surface of the sleeve 12. Therefore, when the plunger 13 is urged by the spring 18 when the valve is closed, the ball valve body 16 may come into contact with the ball valve body 16 while being inclined with respect to the axial direction in the sleeve 12. However, since the ball valve body 16 has a spherical surface and can move somewhat in a direction perpendicular to the axial direction, the upper end surface of the plunger 13 can seat the ball valve body 16 in an inclined state. The relative shape of the seating portion between the plunger 13 and the ball valve body 16 does not change. Therefore, since no gap is generated between the upper end surface of the plunger 13 and the ball valve body 16, a sufficient sealing performance can be obtained when the valve is closed.
[0021]
When the solenoid 2 is energized, the plunger 13 is attracted to the protrusion 8 of the case 6 constituting the core against the urging force of the spring 18 and is not subjected to a load of high-pressure fluid, as shown in FIG. Move down to the position in the figure. At this time, the ball valve body 16 moves along with the movement of the plunger 13, but abuts on the shaft 17 in the middle and is left behind on the spot, so that only the plunger 13 is moved. As a result, the upper end surface of the plunger 13 is pulled away from the ball valve body 16, and an annular space between the tip diameter-reduced portion of the shaft 17 and the opening of the plunger 13 is opened to the passage 9 communicating with the outlet port 5. The valve is open. As a result, the fluid introduced into the inlet port 4 passes through the passage 10 of the case 6, the communication groove 14 provided around the plunger 13, the space 11, the groove 17 a formed on the tip surface of the shaft 17, and the hollow portion of the shaft 17. And the passage 6 of the case 6 flows to the outlet port 5.
[0022]
Next, when the solenoid portion 2 is de-energized again, the plunger 13 loses the attracting force from the projection portion 8 of the case 6 and is biased by the spring 18 to be seated on the ball valve body 16, and the fluid passage again Close. Here, when the plunger 13 collides with the ball valve body 16 to be in the valve closed state, the ball valve body 16 is urged by the spring 19 in a state in which the ball valve body 16 can slide in the axial direction. Therefore, the impact on the ball valve body 16 applied from the plunger 13 is absorbed by the spring 19, and the impact sound when hitting the ball valve body 16 can be reduced.
[0023]
In general, the ball valve body 16 is hard and the plunger 13 is formed of a softer material than the ball valve body 16. Therefore, if the impact load generated by the plunger 13 hitting the ball valve body 16 is large, the upper end surface of the plunger 13 that is a valve seat is worn. Here, since the impact is absorbed by the spring 19, the wear of the plunger 13 can be reduced, and the fluid passage can be reliably closed.
[0024]
As mentioned above, as an embodiment of the present invention, the case where the present invention is applied to a two-way solenoid valve that blocks or opens a flow path has been described. However, the solenoid valve according to the present invention is not limited to such an on / off drive solenoid valve. The present invention can also be applied to so-called proportional valves in which the valve opening continuously changes in proportion to the current value supplied to the solenoid unit.
[0025]
【The invention's effect】
As described above, in the present invention, the valve body has a spherical surface, and the cylindrical plunger constituting the valve seat can be contacted and separated. As a result, even if the plunger hits the valve body in an inclined state due to the clearance with the sleeve necessary to make the plunger movable, the relative shape of the portion where the end face of the plunger hits the spherical valve body does not change. It becomes the same state as the automatic alignment, and the plunger can be brought into close contact with the valve body.
[0026]
Further, the pressure of the fluid introduced to both end faces of the plunger that is the valve seat is equally applied. Thereby, since the back pressure of the plunger is canceled, the plunger does not depend on the pressure of the fluid. Therefore, the solenoid force for driving the plunger can be reduced, and the solenoid portion can be reduced in size.
[0027]
Further, in the present invention, a valve seat having a spherical valve seat surface is received by a spring. Thereby, the load when the plunger collides with the valve seat can be absorbed by the spring, the impact sound during the switching operation can be reduced, and the wear of the plunger can be reduced.
[Brief description of the drawings]
FIG. 1 is a central longitudinal sectional view showing a state when a two-way solenoid valve according to an embodiment of the present invention is not energized.
FIG. 2 is a central longitudinal sectional view showing a state when a two-way solenoid valve according to an embodiment of the present invention is energized.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve part 2 Solenoid part 3 Body 4 Inlet port 5 Outlet port 6 Case 7 Fluid introduction groove 8 Projection part 9 Passage 10 Passage 11, 11a Space 12 Sleeve 13 Plunger 14 Communication groove 15 Cap 16 Ball valve element 17 Shaft 17a Groove 18 Spring 19 Spring 20 Electromagnetic coil 21 Yoke 22 Plate 23 Flange 24 Wiring

Claims (4)

In a solenoid valve composed of a valve portion that opens and closes a fluid passage by a valve body arranged to face the valve seat and the valve seat, and a solenoid portion that drives to change the relative position of the valve body and the valve seat ,
A valve body disposed in the middle of the fluid passage so as to be movable back and forth in the axial direction and having a spherical surface.
A cylindrical plunger that is disposed in the middle of the fluid passage so as to be movable back and forth in the axial direction, has an opening formed at a central axial position, and an end surface of the opening functions as a valve seat for the valve body;
A first spring that urges the plunger toward the valve body;
A core which is fixedly disposed at an axial position opposite to the side where the valve body is provided with respect to the plunger, and a passage is formed at a central axial position;
A hollow shaft that is inserted into the opening of the plunger, one end is fixed to the passage of the core, and at least one groove passing through the center is formed on an end surface facing the valve body;
A second spring that urges the valve body in a direction to contact the end surface of the shaft and absorbs an impact of the plunger on the valve body when the valve is closed;
A solenoid valve characterized by comprising: The electromagnetic valve according to claim 1, wherein the valve body is a ball. The shaft has a reduced diameter at the tip portion facing the valve seat, and a space communicating with the downstream side through the groove is formed between the opening and the plunger when the valve is closed. The solenoid valve according to claim 1, characterized in that: The said plunger has a some communication groove formed in the outer peripheral part so that it may extend in an axial direction, The said core has the channel | path which introduces the fluid from the fluid inlet to the said plunger side. Solenoid valve.

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