JP2003049963A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve capable of achieving a sufficient sealing property even when a valve element is seated in an inclined state with respect to an axial direction of a valve seat, and capable of miniaturizing a solenoid part. SOLUTION: The ball valve element 16 having a spherical surface is energized so as to be abutted onto the other end of a hollow shaft 17 fixed on a protrusion 8 of a case 6 of which one end constitutes a core and communicating with an exit port 5. The tubular valve seat capable of approaching and separating with respect to the ball valve element 16 is arranged. The valve seat is constituted of a plunger 13 of the solenoid part 2. Thus, the plunger 13 abuts onto a curved surface of a same shape which enables the plunger 13 and the ball valve element 16 to be sealed tightly even when the plunger 13 is obliquely abutted onto the ball valve element 16. By communicating both end surface sides of the plunger 13, a back pressure cancelling structure independent of a fluid pressure can be achieved. Thus, solenoid force required on opening valve is reduced and the solenoid part 2 is miniaturized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, and more particularly to a solenoid valve capable of switching and controlling high-pressure fluid with a small solenoid force.

[0002]

2. Description of the Related Art Conventionally, a solenoid 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 element that is arranged so as to face the valve seat, and a solenoid portion that drives the valve element with respect to the valve seat.

The valve portion is provided with two ports formed in the body, a valve seat disposed between the ports and integrally formed with the body, and a valve body which is opened and closed by a solenoid portion. . Further, the solenoid portion is provided with an electromagnetic coil to which a control current is supplied from the outside, a core functioning as a fixed iron core fixed at an axial position of the electromagnetic coil, and an axial forward / backward movement at the axial position of the electromagnetic coil. It is provided with a plunger that functions as a movable iron core arranged and a spring that urges the plunger in the opening or closing direction with respect to the valve body of the valve portion.

By the way, the valve body has various shapes,
A flat valve with a flat valve seat, a tapered valve that opens and closes a cone-shaped valve to open and close, and a needle valve that opens and closes a needle-shaped valve to open and close are known. There is.

[0005]

However, in the taper valve or the needle valve, the axial position of the valve seat does not coincide with the advancing / retreating direction of the valve body, or the taper valve or the needle valve is slightly inclined with respect to the axial direction of the valve seat. In that case, a gap is created between the valve seat and the valve seat, and the seal becomes incomplete. Therefore, there is a problem that fluid leakage may occur in the valve portion.

Further, the solenoid valve for switching the high-pressure fluid needs to drive the valve body with a solenoid force higher than the fluid pressure received by the valve body, which causes a problem that the solenoid portion becomes large.

The present invention has been made in view of the above points, and a sufficient seal can be obtained even when the valve body is seated in a state where the valve body is inclined with respect to the axial direction of the valve seat, and the valve is An object of the present invention is to provide a solenoid valve that can reduce the size of a solenoid that drives a body.

[0008]

In order to solve the above problems, the present invention is directed to a valve portion for opening and closing a fluid passage by a valve seat and a valve body arranged to face the valve seat, and a valve body and a valve seat. In a solenoid valve composed of a solenoid portion that is driven so as to change the relative position with respect to the fluid passageway, a valve body having a spherical surface is disposed in the middle of the fluid passageway so as to be movable back and forth in the axial direction. A cylindrical plunger that is arranged so as to be able to move back and forth in the axial direction along the way, has an opening at the central axis position, and has an end surface of the opening that functions as a valve seat for the valve body, and the plunger as the valve body. A first spring for biasing in the direction of, a core fixedly arranged at an axial position opposite to the side where the valve element is provided with respect to the plunger, and having a passage formed at a central axial position; Plunger A hollow shaft which is inserted into the opening, one end of which is fixed to the passage of the core, and at least one groove passing through the center is formed in an end surface facing the valve body, and a direction in which the shaft abuts the end surface of the shaft. A second spring that urges the valve element to absorb the impact of the plunger on the valve element when the valve is closed,
There is provided a solenoid valve comprising:

According to such an electromagnetic valve, a valve body having a spherical surface which can be moved 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 surface is formed at an end face opening portion of the plunger. The shaped valve body is seated. As a result, even if the plunger is seated on the valve body in an inclined state due to the presence of the clearance between the plunger and the sleeve required 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 of the plunger is displaced, the state is the same as when the axis is automatically adjusted, and the plunger and the valve body can be closely sealed.

Further, according to the present invention, a plurality of communicating grooves extending in the axial direction are formed on the outer peripheral portion of the plunger so that the fluid pressure on the inlet side is introduced into the end surface on the core side of the plunger. As a result, the pressure of the fluid introduced to both end surfaces of the plunger, which is the valve seat, is evenly applied, and the movement of the plunger does not depend on the pressure of the fluid. Therefore, since the solenoid can be driven only by the solenoid force, the solenoid force can be reduced and the solenoid portion can be downsized.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings, taking a case where the embodiment is applied to a two-way solenoid valve as an example.

FIG. 1 is a central longitudinal sectional view showing a non-energized state of a two-way solenoid valve according to an embodiment of the present invention, and FIG. 2 is a two-way solenoid valve according to an embodiment of the present invention when energized. It is a central longitudinal cross-sectional view showing a state.

The two-way solenoid valve according to the embodiment is composed of a valve portion 1 provided at a lower portion and a solenoid portion 2 provided at an upper portion. The valve unit 1 includes a body 3 and an inlet port 4 and an outlet port 5 provided on the side surface of the body 3. A case 6 forming a flow path between the inlet port 4 and the outlet port 5 is press-fitted into the body 3 through the upper opening. An annular fluid introduction groove 7 communicating with the inlet port 4 is formed in the case 6, and a cylindrical protrusion 8 is provided at the center of the upper portion. The protrusion 8 constitutes a core of a magnetic circuit including an electromagnetic coil 20 described later. In addition, the case 6 is provided with a passage 9 penetrating the central axis of the protrusion 8 and communicating with the outlet port 5, and in addition to the passage 9, the passage 9 extends from the fluid introduction groove 7 to the upper end surface of the protrusion 8. A plurality of passages 10 are formed so as to surround the passage 9.

The solenoid portion 2 has a sleeve 12 whose lower end is fitted to the outer peripheral surface of the protruding portion 8 of the case 6. A plunger 13, which is a movable iron core, is fitted and disposed in the sleeve 12 so as to be movable back and forth in the axial direction, and the projecting portion 8 of the case 6 forms a core that functions as a fixed iron core with respect to the plunger 13. There is. The plunger 13 has a cylindrical shape with an opening penetratingly formed at the central axis position, and a plurality of communication grooves 14 extending in the axial direction are formed on the outer peripheral portion of the plunger 13. A cap 15 is screwed onto the sleeve 12.

A ball valve element 16 having a spherical surface is arranged between the cap 15 and the plunger 13 so as to be movable back and forth 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 element 16. The plunger 13 has a back pressure canceling structure in which the fluid pressure applied to the surface on the side of the ball valve body 16 and the surface on the side opposite to the same are equalized by the communication groove 14 thereof.

The hollow shaft 17 penetrates through the opening of the plunger 13 and has its lower end inserted and fixed in a passage 9 formed at the axial position of the projection 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 face. The space 11 on the upper end surface side of the plunger 13, the hollow portion of the shaft 17, and the passage 9 on the downstream side communicate with each other via the groove 17a.

A spring 18 for urging the plunger 13, which is a valve seat, is arranged between the plunger 13 and the protrusion 8 of the case 6 so that the ball valve body 16 is seated. Further, between the cap 15 and the ball valve body 16,
A spring 19 is arranged to urge the ball valve element 16 against the shaft 17 and absorb the impact of the plunger 13 on the ball valve element 16 when the valve is closed.

An electromagnetic coil 20 is provided on the outer circumference of the sleeve 12.
Are arranged, and the outside thereof is surrounded by the 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 section 2. Further, the lower end portion of the yoke 21 is fixed to a flange 23 that constitutes a part of the magnetic circuit of the solenoid portion 2 and that is used to attach the valve portion 1 to the body 3. A wiring 24 for supplying a control current from the outside to open and close the two-way solenoid valve is connected to the electromagnetic coil 20.

Here, as shown in FIG. 1, when the solenoid portion 2 is not energized, the plunger 13 is
The ball valve body 16 which is moved upward in the figure by the spring 18 and is urged downward in the figure by the spring 19 is seated on the upper end surface to close the fluid passage. Here, when the high-pressure fluid flows in 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 via the passage 10. The fluid introduced here is further introduced into the space 11 on the upper end surface side of the plunger 13 via the communication groove 14 provided around the plunger 13. As a result, the plunger 13 receives the same 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 urging force of the spring 18 can reliably maintain the valve closed state.

Further, since the ball valve body 16 has a spherical surface, it is possible to enhance the sealing performance with the upper end surface of the plunger 13 functioning as a valve seat. That is, the plunger 13 disposed in the sleeve 12 so as to be movable back and forth in the axial direction is provided with a clearance between the plunger 13 and the inner wall surface of the sleeve 12. Therefore, when the valve is closed, the spring 1
When the plunger 13 is biased at 8, it may come into contact with the ball valve element 16 in a state of being inclined with respect to the axial direction in the sleeve 12 and may be seated. However, since the ball valve body 16 has a spherical surface and can move a little in the direction perpendicular to the axial direction, the plunger 13
Even if the upper end surface of the seated ball valve element 16 is inclined,
The relative shape of the seated 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 element 16, sufficient sealing performance can be obtained when the valve is closed.

When the solenoid portion 2 is energized, the plunger 13 is adsorbed by the projecting portion 8 of the case 6 which constitutes the core against the biasing force of the spring 18, and is not subjected to the load of the high pressure fluid. Move down to the position shown in 2. At this time, the ball valve body 16 moves along with the movement of the plunger 13, but the ball valve body 16 comes into contact with the shaft 17 in the middle and is left in place, and 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 the annular space between the tip reduced diameter 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 opened. As a result, the fluid introduced into the inlet port 4 passes through the passage 10 of the case 6 and the communication groove 1 around the plunger 13.
4, space 11, groove 1 formed on the tip surface of the shaft 17
7a, hollow portion of shaft 17, and passage 9 of case 6
Through the outlet port 5.

Next, when the solenoid portion 2 is again de-energized, the plunger 13 loses the attraction force from the protrusion portion 8 of the case 6 and is urged by the spring 18 to be seated on the ball valve body 16 and the fluid. Close the passage again. 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 biased by the spring 19 in a slidable state in the axial direction. Therefore, the impact applied from the plunger 13 to the ball valve body 16 is absorbed by the spring 19, and the ball valve body 1
It is possible to reduce the impact sound when hitting 6.

In general, the ball valve body 16 is hard and the plunger 13 is made of a material softer than the ball valve body 16. Therefore, when the impact load generated by the plunger 13 hitting the ball valve body 16 is large, the upper end surface of the plunger 13 which is the valve seat is worn. Here, since the shock is absorbed by the spring 19, the wear of the plunger 13 can be reduced and the fluid passage can be reliably closed.

As described above, the embodiment of the present invention has been described as applied to the two-way solenoid valve for shutting off or opening the flow passage. However, the solenoid valve according to the present invention is such an on / off driven solenoid valve. The present invention is not limited to the above, but can be applied to a so-called proportional valve in which the valve opening continuously changes in proportion to the current value supplied to the solenoid portion.

[0025]

As described above, in the present invention, the valve body has a spherical surface, and the cylindrical plunger forming the valve seat can be brought into contact with and separated from the valve body. This allows
Even if the plunger hits the valve body in a tilted state due to the clearance with the sleeve required to make the plunger movable, the relative shape of the part where the end face of the plunger and the spherical valve body touch does not change. The plunger is brought into close contact with the valve body in the same state as when it is aligned.

Further, the pressure of the fluid introduced to both end surfaces of the plunger, which is the valve seat, is equalized.
As a result, the back pressure of the plunger is canceled, so that the plunger does not depend on the pressure of the fluid, so that the solenoid force for driving the plunger can be reduced and the solenoid portion can be downsized.

Further, in the present invention, the valve seat having the spherical valve seat surface is received by the spring. As a result, the load when the plunger collides with the valve seat can be absorbed by the spring, the impact noise during the switching operation can be reduced, and the wear of the plunger can be reduced.

[Brief description of drawings]

FIG. 1 is a central longitudinal sectional view showing a state of a two-way solenoid valve according to an embodiment of the present invention when not energized.

FIG. 2 is a central longitudinal cross-sectional view showing a state when the two-way solenoid valve according to the embodiment of the present invention is energized.

[Explanation of symbols]

1 valve 2 Solenoid part 3 body 4 entrance ports 5 exit ports 6 cases 7 Fluid introduction groove 8 protrusions 9 passages 10 passages 11,11a space 12 sleeves 13 Plunger 14 communication groove 15 caps 16 ball disc 17 shaft 17a groove 18 spring 19 spring 20 electromagnetic coil 21 York 22 plates 23 Flange 24 wiring

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Claims (4)

[Claims] 1. A valve section comprising a valve seat and a valve body arranged to face the valve seat to open and close a fluid passage, and a solenoid section for driving the valve body and the valve seat to change the relative position. In the solenoid valve described above, a valve element is arranged in the fluid passage so as to be movable back and forth in the axial direction and has a surface having a spherical shape, and is arranged so as to be movable back and forth in the axial direction in the middle of the fluid passage,
A cylindrical plunger having an opening formed at a central axis position and an end surface of the opening functioning as a valve seat for the valve body, and a first spring for urging the plunger toward the valve body. A core that is fixedly disposed at an axial position on the side opposite to the side where the valve element is provided with respect to the plunger, and has a passage formed at a central axial position; and the core is inserted into the opening of the plunger and has one end A hollow shaft fixed to the passage of the core and having at least one groove passing through the center at an end surface facing the valve body; and urging the valve body in a direction to abut the end surface of the shaft. A second spring that absorbs an impact of the plunger with respect to the valve element when the valve is closed; 2. The solenoid valve according to claim 1, wherein the valve body is a ball. 3. A distal end portion of the shaft facing the valve seat has a reduced diameter, and when the valve is closed, a space communicating with the downstream side through the groove is formed between the shaft and the opening portion of the plunger. The solenoid valve according to claim 1, wherein the solenoid valve is formed. 4. The plunger has a plurality of communication grooves formed in an outer peripheral portion so as to extend in the axial direction, and the core has a passage for introducing a fluid from a fluid inlet to the plunger side. The solenoid valve according to claim 1.