JP2003130247A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve allowing one end of a rod as a valve element to be securely seated on a valve seat even when a plunger is seated with axially shifting. SOLUTION: This solenoid valve comprises the valve seat 1, the rod 2 as the valve element seated on the valve seat 1 at the end 2a, the plunger 3 having an engaging hole 3a for the other end 2d of the rod 2 to be coaxially engaged and a solenoid 4 for axially absorbing the plunger 3 when magnetized. A predetermined engaging gap 3b is formed between the other end 2d of the rod 2 and the engaging hole 3a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve for controlling fluid communication and shutoff, and more particularly to a solenoid valve capable of improving the seatability of a rod on a valve seat.

[0002]

2. Description of the Related Art As a conventional solenoid valve, a valve seat, a rod which is a valve body having one end seated on the valve seat, and a fitting hole for coaxially fitting and fixing the other end of the rod are formed. Some of them are equipped with a plunger that is energized and a solenoid that attracts the plunger in the axial direction when excited. This solenoid valve is a normally closed valve or a normally open valve that is urged by an urging member such as a spring in a direction opposite to the direction in which the plunger is attracted by the solenoid when not energized. When the solenoid is energized by being energized and the plunger is attracted to the solenoid, the plunger moves axially against the biasing force of the biasing member, and the rod fitted and fixed to the plunger also moves axially. However, since the magnetic force of the solenoid acts not only in the axial direction of the plunger but also in the radial direction due to variations in each component, the plunger may be displaced not only in the axial direction but also in the radial direction. At this time, one end of the rod is also displaced in the radial direction together with the plunger. At this time, one end of the rod deviates from the normal seating position of the valve seat and abuts against the valve seat, so that one end of the rod cannot be seated accurately on the valve seat, and the working fluid leaks.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic valve in which one end of a rod, which is a valve element, can be reliably seated on a valve seat even when the plunger is seated while being displaced in the radial direction.

[0004]

A first technical means taken to solve the above technical problem is, as shown in claim 1, a valve seat and a valve body having one end seated on the valve seat. And a solenoid having a fitting hole for coaxially fitting the other end of the rod, and a solenoid that attracts the plunger in the axial direction when excited. The electromagnetic valve is characterized in that a predetermined fitting gap is provided between the other end of the rod and the fitting hole.

According to the above construction, even when the plunger is displaced in the radial direction by the magnetic force generated by the solenoid acting in the radial direction, one end of the rod is provided with a predetermined distance between the valve seat and the fitting hole when abutting on the valve seat. Since the fitting gap can be moved, one end of the rod can be moved to the normal seating position of the valve seat and seated accurately. As a result, it is possible to suppress leakage of the working fluid when one end of the rod is seated on the valve seat.

More preferably, as shown in claim 2, the rod is made of a non-magnetic material, and the solenoid valve according to claim 1 is preferable.

With the above construction, when the plunger is attracted in the axial direction by the excited solenoid, the rod is a non-magnetic material and is not affected by the magnetic force in the radial direction from the solenoid. It is possible to move freely within the fitting gap of. Therefore, the seatability of the rod at one end on the valve seat can be further improved.

More preferably, as shown in claim 3, the other end surface of the rod which comes into contact with the bottom of the fitting hole is formed into a hemispherical surface. It is good to use a valve.

According to the above construction, even when the rod and the plunger are tilted with respect to each other and the rod is pressed by the plunger, the bottom of the fitting hole presses the other end surface of the rod formed in a hemispherical shape. Therefore, the moment acting in the direction of eliminating the above-mentioned inclination does not act on the rod. Such a moment acts to reduce the seatability of one end of the rod on the valve seat when the rod is pushed by the plunger while being inclined with respect to the plunger. Therefore, according to this, the seatability of one end of the rod on the valve seat can be further improved.

In addition, as described in claim 4, claim 1
The solenoid valve according to any one of items 1 to 3 is a normally-closed valve that opens when the solenoid attracts the plunger and the rod, and separates the rod and the valve seat from each other. An electromagnetic valve according to any one of claims 1 to 3, wherein an urging member that generates an urging force in a direction is arranged.

When the working fluid is vacuum-filled in the fluid circuit including the normally closed solenoid valve, it is necessary to excite the solenoid to open the solenoid valve. At this time, according to the above configuration, the rod is reliably separated from the valve seat by the urging force of the urging member even when the pressure of the working fluid is not applied to one end of the rod from the valve seat side. Can be reliably held in the open state.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The configuration of a normally-closed solenoid valve which is a specific example of the present invention will be described below with reference to the attached FIG.

The solenoid valve of this example is used in an ABS modulator of a vehicle braking system.

As shown in FIG. 1, the solenoid valve of this embodiment is provided with a substantially cylindrical iron sleeve 6 having a small diameter portion 6c, and below the sleeve 6 is a bottomed cylindrical sleeve having a space 1a inside. The iron valve seat 1 is press-fitted with the bottom part facing up. A communication hole 1c is formed in the axial direction at the center of the circular bottom portion 1b of the valve seat 1. A mortar-shaped recessed seat portion 1d is formed coaxially with the communication hole 1c on the upper surface of the bottom portion 1b of the valve seat 1 shown in FIG. The solenoid valve of this example further includes a rod 2 made of a non-magnetic material. The rod 2 is above the upper surface of the bottom portion 1b of the valve seat 1, and one end 2a thereof has a cone shape that is narrowed toward the valve seat 1. A tip portion of one end 2a of the rod 2 has a hemispherical shape, and is arranged so as to be able to contact the concave seating portion 1d. An engaging flange 2b that projects in the radial direction is formed over the entire circumference of the cone-shaped portion of the rod 2 shown in FIG. Further, the rod 2 has a cylindrical portion 2c extending axially above the flange 2b shown in FIG. The upper end of the cylindrical portion 2c, that is, the other end 2d of the rod 2 has a hemispherical shape.

A flange 2b is provided between the valve seat 1 and the rod 2.
A coil spring 5 having one end abutted on the lower surface thereof and the other end abutted on a concave seating portion 1d provided on the upper surface of the bottom portion 1b of the valve seat 1 is disposed. The coil spring 5 lifts the rod 2 upward and biases the rod 2 upward in FIG. 1 with a spring force required to separate the end 2a from the valve seat 1. An iron plunger 3 is coaxially arranged above the rod 2 in FIG. The cylindrical portion 2c of the rod 2 is loosely fitted in the fitting hole 3a of the plunger 3, and a predetermined fitting gap 3b is provided between the cylindrical portion 2c and the inner peripheral surface of the fitting hole 3a. The plunger 3 slides on the inner peripheral surface of the sleeve 6 in the axial direction. Inner surface of the sleeve 6,
A space 6e is formed between the rod 2 and the plunger 3. A communication passage 6b is formed in the sleeve 6 in the radial direction so as to penetrate from the outer peripheral surface to the inner peripheral surface.

An iron yoke 10 is integrally formed on the substantially cylindrical sleeve 6 via a metal ring 16 made of a non-magnetic material. The rod 2, the coil spring 5, the plunger 3, the contact pin 13, and the coil spring 14 are arranged in the sleeve 6, and after the valve seat 1 is press-fitted into the lower portion of the sleeve 6, the lower end of the valve seat 1 in FIG. The oil filter 7a is attached to the opening of the communication hole 6b.
With b fixed, the sleeve 6 is fitted into the fitting hole 8a formed in the base portion 8 of the modulator in the vertical direction in FIG.
Engagement recesses 6a are formed on the outer peripheral surface of the sleeve 6 over the entire circumference, and after they are fitted to the base portion 8 of the modulator made of aluminum, they are caulked by a jig or the like from above in FIG. By punching 8b, the lower portion of the caulking hole 8b of the base portion 8 plastically deforms and enters the engaging recess 6a, and the sleeve 6 is caulked and fixed to the base portion 8.

A fitting portion 9b is formed by punching on a bottom portion 9a of an iron case 9 having a bottomed cylindrical shape having a diameter larger than that of the sleeve 6. The fitting portion 9b is axially shown in FIG.
It extends downward. A substantially cylindrical iron yoke 10
Is the engagement hole 10a having a predetermined depth in the axial direction from the center of one end side.
The yoke 10 is press-fitted into the fitting portion 9b so that the engagement hole 10a opens downward in FIG.
A through hole 9c is formed in the bottom portion 9a. Figure 1
A resin bobbin 11 around which the solenoid coil 4 is wound is disposed below the fitting portion 9b and outside the yoke 10 in the radial direction. A guide portion 11a is integrally formed on the upper portion of the bobbin 11 in FIG.
Is inserted through the through hole 9c and exposed to the outside of the case 9.
A lead wire 12 for feeding power to the solenoid coil 4 extends through the insertion hole 11b of the guide portion 11a to the outside.

A locking recess 3c is formed at the upper end of the plunger 3, and the head 13a of the abutment pin 13 is accommodated in the locking recess 3c in contact with the bottom surface of the locking recess 3c. . A coil spring 14 whose one end is in contact with the locking portion 13 b of the contact pin 13 is fitted outside the contact pin 13. The sleeve 6 below the small diameter portion 6c of the sleeve 6 and above the fitting portion of the modulator to the base portion 8
On the outer peripheral surface of the, an annular metal ring 1 having a diameter larger than this outer peripheral surface
5 is fitted. The case 9 having the bobbin 11 and the metal ring 15 mounted thereon is pressed from above until the lower end 9d of the case 9 comes into contact with the modular base portion 8, and the yoke 10
Fixed to. At this time, the other end of the coil spring 14 contacts the bottom of the engagement hole 10a of the yoke 10. The coil spring 14 causes the contact pin 13 and the plunger 3 by the spring force.
Further, the rod 2 is biased downward in FIG. 1 with respect to the yoke 10, and one end 2a of the rod 2 is brought into contact with the concave seating portion 1d of the valve seat 1. At this time, the one end 2a of the rod 2 closes the opening of the communication hole 1c of the valve seat 1, and blocks the communication between the space 1a in the valve seat 1 and the space 6e in the sleeve 6.

Communication passages 8c and 8d extending in the radial direction (rightward in FIG. 1) are formed on the inner peripheral surface of the fitting hole 8a formed in the base portion 8 of the module. The communication passage 8c is connected to the input port 17 communicating with the wheel cylinder, and the communication passage 8d
Are respectively connected to output ports 18 communicating with the reservoir.

Next, the operation of the solenoid valve according to this embodiment will be described below with reference to FIG.

The solenoid valve of this embodiment is a normally closed valve which is closed when not in operation, and shuts off the communication between the communication passage 8c (input port 17) and the communication passage 8d (output port 18). The rod 2 and the plunger 3 are biased downward in FIG. 1 by the coil spring 14 via the contact pin 13, and the one end 2a of the rod 2 closes the opening of the valve seat 1 and the communication passage 8c is provided. The connecting space 1a and the space 6e connecting to the communication passage 8d are blocked.

The solenoid valve of this embodiment operates by supplying power to the solenoid coil 4 via the lead wire 12 of FIG. The solenoid coil 4 generates magnetic flux by power supply, and the magnetic flux generated by the solenoid coil 4 attracts the iron plunger 3.
The plunger 3 is opposed to the biasing force of the coil spring 14.
Slides in the sleeve 6 in the upward direction in FIG. Along with this, the rod 2 pressed against the valve seat 1 below by the plunger 5 is urged by the coil spring 5 and the space 1a.
The space 1a is lifted upward by the pressure received from the opening of the valve seat 1 by the hydraulic pressure inside, and the end 2a of the rod 2 is separated from the opening of the communication passage 1d of the valve seat 1 and connected to the communication passage 8c.
And the space 6e connected to the communication passage 8d are communicated with each other. When the power supply to the solenoid coil 4 is stopped and the magnetic flux of the solenoid coil 4 disappears, the suction force acting on the plunger 5 also disappears and the urging force of the coil spring 14 causes the plunger 5 to move.
1 returns to the downward direction of FIG. 1, and the one end 2a of the rod 2 again closes the opening of the communication hole 1c of the valve seat 1.

Not only the solenoid coil 4 of the solenoid valve of this example, but the actual magnetic flux density generated by the solenoid coil is not uniform in the circumferential direction, and the magnetic flux is slightly biased. Therefore, the suction force acting on the plunger 3 also has a radial component, and the plunger 3 slides in the sleeve 6 in a state in which it is biased to one side in the radial direction. When the plunger 3 is biased to one side in the radial direction and returns to the downward direction in FIG. 1 by the spring force of the coil spring 14, the entire rod 2 is also biased to the valve seat 1 in the one biased direction together with the plunger 3. . In the solenoid valve of the present invention, a predetermined fitting gap 3b is provided between the cylindrical portion 2c of the rod 2 and the fitting hole 3a of the plunger 3. The operation of the gap 3b will be described below. The plunger 3 and the rod 2 that are displaced in the radial direction return to the downward direction in FIG. 1, and one end 2a of the rod 2 is displaced from the opening of the communication hole 1c and abuts on the mortar-shaped slope of the concave seat portion 1d of the valve seat 1. After that, the one end 2a of the rod 2 slides down toward the opening of the communication hole 1c of the valve seat 1. Along with this, the rod 2 tends to incline with respect to the plunger 3. Fitting gap 3 between the rod 2 and the fitting hole 3a of the plunger 3 described above.
b has a space that allows this inclination, and the rod 2 can be inclined with respect to the plunger 3. One end 2a of the rod 2 closes the opening of the communication hole 1c of the valve seat 1 and can reliably block the space 1a and the space 6e.

Further, since the other end 2d of the rod 2 is formed in a hemispherical shape, a moment acting on the rod 2 in the direction of eliminating the above-mentioned inclination with respect to the pressure from the bottom of the fitting hole 3a of the plunger 3 is exerted. Does not occur. Therefore, the one end 2a of the rod 2 described above smoothly moves on the slope of the concave seating portion 1d, and the seatability of the one end 2a of the rod 2 on the valve seat 1 is further improved.

As described above, the solenoid valve of this embodiment is a normally closed valve, but the present invention can be suitably applied to a normally open valve. That is, when the rod is seated on the valve seat due to the sliding of the plunger into which the rod, which is the valve body, is fitted, the radial deviation of the plunger from the inner peripheral surface of the fitting hole of the plunger as described above. Absorb with a predetermined radial fitting gap between rods
Adjust it. Further, the present invention is similarly suitably applied to a linear valve whose opening degree changes linearly and a check valve which changes on and off.

Particularly in the case of a linear valve, when power is supplied to the solenoid coil 4 and the differential pressure between the input port 17 and the output port 18 is maintained, even if the plunger 3 is displaced in the radial direction, one end 2a of the rod 2 is The self-aligning action works, and the one end 2a of the rod 2 does not shift in the radial direction. Therefore,
It becomes easy to maintain and control the differential pressure to a desired value.

The solenoid valve of this embodiment is used for a braking system of an automobile, and the brake fluid is filled in the braking system by operating the solenoid valve and sucking the plunger 3 upward in FIG. Vacuum filling method is used. The brake fluid is connected from the output port 18 side to the communication passage 8d and the communication hole 6
b, the space 6e, the communication hole 1c in the opened state, the space 1a and the communication passage 8c, and the vacuum is drawn toward the input port 17. Since the rod 2 is loosely fitted in the plunger 3, even if the plunger 3 slides upward in FIG. 1, the plunger 3 does not directly pull up the rod 2.
However, since the coil spring 5 lifts the rod 2 upward in accordance with the upward sliding of the plunger 3, the brake fluid space 6e is filled when the brake fluid is vacuum filled.
The one end 2a of the rod 2 is sucked into the communication hole 1c by the flow from the inside to the space 1a, and the one end 2a of the rod 2 is connected to the communication hole 1c.
Blocking c is prevented. Therefore, it becomes possible to hold the solenoid valve in the open state during vacuum filling.

[0028]

According to the present invention, it is possible to construct an electromagnetic valve in which one end of a rod, which is a valve element, can be reliably seated on a valve seat even when the plunger is seated while being displaced radially. Also, when the working fluid is filled in the fluid circuit including the normally closed solenoid valve, it is necessary to excite the solenoid coil to open the solenoid valve, but the rod is reliably separated from the valve seat by the urging force of the urging member. ,
It is possible to reliably hold the normally closed electromagnetic valve in the open state even when the fluid pressure is not applied to one end of the rod from the valve seat side.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the configuration of a normally closed solenoid valve that is a specific example of the present invention.

[Explanation of symbols]

1 valve seat 2 rod 2a One end of rod The other end of the 2d rod 3 Plunger 3a Fitting hole 3b Mating gap 4 solenoid 5 Coil spring (biasing member)

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Claims (4)

[Claims] 1. A valve seat, a rod, which is a valve body having one end seated on the valve seat, a plunger having a fitting hole for coaxially fitting the other end of the rod, An electromagnetic valve comprising a solenoid for attracting the plunger in the axial direction when a predetermined fitting gap is provided between the other end of the rod and the fitting hole. 2. The solenoid valve according to claim 1, wherein the rod is made of a non-magnetic material. 3. The solenoid valve according to claim 1, wherein the other end surface of the rod that comes into contact with the bottom of the fitting hole is formed into a hemispherical surface. 4. The solenoid valve according to claim 1, wherein the solenoid valve is a normally closed valve that opens when the solenoid attracts the plunger and the rod, and An urging member that generates an urging force in a direction in which the two are separated from each other is disposed therebetween.
4. The solenoid valve according to any one of items 1 to 3.