JPH09210240A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-pressure fluid control at less power by providing first energizing member inserted closely between a movable iron core and a valve stem, a member to support the lower end of the first energizing member which is fixed to the movable iron core and fitted loosely to the valve stem through a specified clearance, and a second energizing member to energize the valve stem in the direction of a valve seat. SOLUTION: When a current is not passed, a pin 8 is brought in contact with the underside of a through hole 3c. At this time, a space S1 is provided on the upper side and a space St is provided between a movable iron core 2 and a fixed iron core 15. When a current is passed, in the beginning at which a suction force is small, only the movable iron core 2 is raised by a space of S1 though a valve stem 3 is not raised at all. Next a raising suction force acts largely and the movable iron core 2 and valve stem 3 are raised together. Immediately after they are risen, a clearance between the valve body 25 and a valve seat 24 is St to S1. However, the valve stem 3 rises further by an amount of S1 by the elastically expanding force of a first spring 4, and the clearance is increased to St so as to open the valve. Because, in the beginning of sucking, a load against the suction force of the fixed iron core 15 is only the first spring 4, an applied voltage to a coil 12 required is very small.

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 the flow of a fluid, and more particularly to a small solenoid valve capable of controlling a high-pressure fluid with a small voltage.

[0002]

2. Description of the Related Art Conventionally, various forms of solenoid valves have been used for fluid control, one example of which will be described with reference to the drawings. FIG. 7 is a sectional view showing a first conventional example of a solenoid valve. In the electromagnetic valve 51, a fixed iron core 54 is fixed to a magnetic frame 53 around which a coil 52 is wound.
A solenoid portion in which a movable iron core 55 is inserted so as to be able to contact and separate from the fixed iron core 54 is configured. Further, the outer peripheral surface of the solenoid portion is molded and fixed by a cover 56 formed of resin so that the whole is integrated.

The movable iron core 55 has a valve body 57 held at its lower end, and is urged downward by a spring 59 which comes into contact with the upper surface of the flange and the guide pipe 58. Below the movable iron core 55 urged by the spring 59, a valve seat 60 for the valve body 57 is formed in the body 61. Further, the body 60 has an input port 6 through which a fluid flows.
2 and an output port 63 communicating with the valve hole of the valve seat 60 are formed.

[0004] Incidentally, in the solenoid valve, at the initial stage of suction at the moment when the movable core is attracted by energizing the coil, the stationary core and the movable core are at the most distant positions, so that the attracting force at that time is the weakest. Therefore, in the electromagnetic valve 51 of the first conventional example, as the pressure of the fluid flowing in the body 61 becomes higher, the force for making the valve body 57 airtightly contact the valve seat 60 also becomes larger. However, if the force urging the movable iron core 55 downward in proportion to the fluid pressure becomes large,
On the other hand, the operating voltage to the coil 52 that is going to be attracted to the fixed iron core 54 needs to be large,
Use in high pressure fluids required high power.

In order to solve such a problem, a solenoid valve disclosed in Japanese Patent Application Laid-Open No. 1-145484 will be described with reference to the drawings. FIG. 8 is a cross-sectional view of a second prior art solenoid valve disclosed in this publication. The electromagnetic valve 71 has concave portions formed at the upper end of the movable iron core 72 and the lower end of the fixed iron core 73, respectively, and is fitted with a first spring 74 for urging the two to be separated from each other. On the other hand, at the lower end of the movable iron core 72, a sliding hole 72a in which a valve rod 76 integral with the valve body 75 slides is formed in the shaft core portion, and the valve rod 76 inserted from below into the sliding hole 72a also slides. The second spring 77 inserted into the hole 72a causes the sliding hole 72a
It is urged to abut the ceiling. Also, the valve body 75
An input port 80 into which fluid flows and an output port 81 communicating with a valve hole of the valve seat 78 are formed in a body 79 in which a valve seat 78 is formed.

When the coil 52 is not energized, the solenoid valve 71 having such a configuration is inserted into the sliding hole 72a by the movable iron core 72 urged downward by the first spring 74. Rod 76 is similarly biased downward. Therefore, the valve body 75 integrally provided at the lower end of the valve rod 76 comes into contact with the valve seat 78 to close the valve. On the other hand, when the coil 52 is energized, the movable core 72 urged by the first spring 74 rises due to the attractive force of the fixed core 73 excited against the force. At this time, since the valve element 75 is pressed against the valve seat 78 by the pressure of the fluid flowing into the body 79, only the movable iron core 72 rises, and the valve rod 76 integrated with the valve element 75 is inserted into the sliding hole 72a. The second
Slides while compressing the spring 77.

When the second spring 77 is compressed to some extent and the distance between the fixed core 73 and the movable core 72 is reduced, the suction force between the fixed core 73 and the movable core 72 increases, and the valve The valve body 75 is separated from the valve seat 78 against the fluid pressure toward the seat 78, and the valve is opened.
Thereafter, when the contracted second spring 77 expands, the valve rod 76 further rises, and the valve is greatly opened. If the current supply to the coil 52 is stopped, the first
The movable iron core 72 and the valve rod 76 are lowered by the elastic expansion force of the spring 74, and the valve body 75 comes into contact with the valve seat 78, and the valve closes again as shown in the figure.

Therefore, Japanese Patent Laid-Open No. HEI-1 cited as the second conventional example.
According to the solenoid valve 71 having the configuration described in Japanese Patent Application Laid-Open No. 145484, at the initial suction stage where the fixed iron core 73 and the movable iron core 72 are farthest apart and the suction force is weak, only the movable iron core 72 is connected to the first spring. 74 and the movable core 72 while moving up against the urging force of the second spring.
In the process of increasing the suction force from immediately before the suction to the suction, the valve body 75 is raised against the pressure of the fluid to raise the valve seat 7.
8, the valve can be opened with a small amount of electric power even when the fluid pressure is large.

[0009]

However, in the solenoid valve 71 of the second conventional example, the movable iron core 72 and the valve body 75 are configured to move independently of each other. In this case, the valve can be opened and closed with a small amount of electric power for opening and closing the valve as compared with the solenoid valve 51 of the first conventional example, but has the following problems. First, when the fixed iron core 73 sucks the movable iron core 72, at the beginning of the weak suction where the energization of the coil 52 is started, the first suction is performed.
Since both the spring 74 and the second spring 77 must be compressed, an operating voltage to the coil 52 for the two added spring forces was required.

Further, only the movable core 72 once rises due to the suction of the fixed core 73, and then is moved to the movable core 72 and the fixed core 7.
In the process of a large suction force from immediately before the suction with the valve 3 to the suction, the valve body 75 is separated from the valve seat against the fluid pressure.
At this time, the valve stem 76 is pulled up to the movable iron core 72 via the second spring 77. Therefore, when the fluid pressure is large, the force received by the second spring 77 is correspondingly large, and the amount of compression is also large. This is likely to occur, and the electromagnetic valve 71 itself may have a short life. On the other hand, if the strength of the second spring 77 is increased, the first
Since the second spring 77 is also compressed together with the spring 74, a large suction force is required, and the above effect is lost.

Further, when the electromagnetic valve 71 is viewed in the axial direction of the fixed iron core 73 and the like, the first spring 74 is interposed between the fixed iron core 73 and the movable iron core 72. It has become larger. Further, the first spring 74 is interposed between the fixed iron core 73 and the movable iron core 72, and the second spring 77 is also interposed between the movable iron core 72 and the valve element 75. Is easily lost, and the stability of the valve body 75 contacting the valve seat 78 may be deteriorated, and the sealing performance may be deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact solenoid valve capable of controlling a fluid at a high pressure with a small amount of power, having a long service life, and solving the above problems.

[0013]

According to the present invention, there is provided a fixed iron core fixedly provided in a solenoid portion around which a conductive coil is wound, and a fixed iron core fixed by an electromagnetic force generated in the fixed iron core by energizing the solenoid portion. A movable iron core that is attracted to the iron core side, and a valve mechanism that performs an opening / closing operation by contacting or separating a valve body and a valve seat that are interlocked with the movement of the movable iron core that is attracted to the fixed iron core; One of the valve stem provided with the valve element and one of the movable iron core and the valve stem is inserted into an insertion hole formed by opening to the other side, and the movable iron core and the valve stem are inserted in the insertion hole. And a lower end of the first biasing member fixed to the movable iron core and loosely fitted to the valve stem through a predetermined gap. Supporting member, and a second bias for biasing the valve stem in the valve seat direction. And having a wood. Further, in the solenoid valve of the present invention, the support member has a fitting hole of the same diameter formed in the movable iron core vertically penetrating a shaft core,
It is desirable that the pin is provided via a wide-diameter fitting hole formed in the valve stem vertically penetrating the shaft core.

In the solenoid valve of the present invention having the above structure, the movable core is attracted to the fixed core side by the electromagnetic force generated by energizing the solenoid part around which the conductive coil is wound. The opening and closing operation of the valve is operated by the contact or separation of the interlocking valve body and the valve seat, but at the time of opening the valve, at the beginning of suction when the solenoid is first energized,
Only the movable iron core is sucked against the urging force of the first urging member applied via the support member, while the valve rod is urged by the second urging member so that the valve body contacts the valve seat. After the support member fixed to the movable iron core has moved by the gap between the loosely fitted valve stem and the valve stem, the valve stem is pulled by the movable iron core via the support member. (2) It moves against the urging force of the urging member. Therefore, in the initial stage of suction, only the suction force against the urging force of the first urging member needs to be applied to the movable iron core, so that high-pressure fluid control with a small amount of electric power is possible.

Further, in the solenoid valve of the present invention, when the valve is opened, the pin serving as the support member is fitted and fixed in the fitting hole of the movable core, so that if the movable core is attracted to the fixed core. While moving together, a gap is formed between the valve body and the large-diameter fitting hole, and the valve stem is kept stationary without interlocking with the movement of the movable iron core over a predetermined distance. Does not affect the suction of the movable iron core. Therefore, in the initial stage of suction, only the suction force against the urging force of the first urging member needs to be applied to the movable iron core, so that high-pressure fluid control with a small amount of electric power is possible.

[0016]

Next, an embodiment of the solenoid valve of the present invention will be described with reference to the drawings. 1 to 4
1 is a sectional view showing a solenoid valve according to the present embodiment, and FIG.
5 shows a state in which the valve is open from the closed state to the open state in FIG. The solenoid valve 1 of the present embodiment is roughly composed of an upper half solenoid portion 10 and a lower half valve portion 20. The solenoid unit 10 and the valve unit 20
A guide pipe 14 extending below the solenoid portion 10
And the body 21 forming the valve portion 20 are
It is fixed vertically by 0.

The solenoid unit 10 has a coil 12 in which a copper wire is wound around a body of a hollow cylindrical coil bobbin 11, and a magnetic frame 13 is formed so as to surround the outer periphery thereof. A hollow cylindrical guide pipe 14 having a lower end flange is inserted and fixed in the cylinder of the coil bobbin 11 so as to be integrally fixed to the body 21 via the lock nut 30 as described above. This coil bobbin 11
A fixed iron core 15 is inserted into and fixed to the vicinity of the center of the coil 12 from above the hollow portion formed by the guide pipe 14. On the other hand, from below, the movable iron core 2 associated with the valve stem 3 having the valve element 25 is connected to the guide pipe 14.
It is fitted and held slidably in the vertical direction. The outer peripheral surface of the solenoid unit 10 is molded and fixed by a cover 17 made of resin so as to be integrated as a whole.

Next, the valve section 20 is connected to the body 21 of the solenoid valve 1.
A valve seat having an input port 22 for flowing fluid into the inside and an output port 23 for discharging fluid in the body 21, and a valve hole formed in the body 21 to communicate the input port 22 and the output port 23. 24 are provided. The valve seat 24 is formed coaxially with the fixed core 15 and the movable core 2. The body 21 is formed with a cylindrical fixing portion 21a projecting upward so as to surround the valve seat 24 and opening upward. A screw cut on a side surface of the fixing portion 21a is inserted through the guide pipe 14. The lock nut 30 is screwed to form the solenoid valve 1.

In the valve section 20, a valve body 25 is disposed at a position where it contacts the valve seat 24 in order to control the flow of the fluid flowing into the body 21. The valve body 25 is sandwiched by the lower end portion of the valve rod 3 that is engaged with the movable iron core 2. The movable iron core 2 is formed of a cylindrical bar having an insertion hole 2a opened downward. On the other hand, valve stem 3
Is composed of an upper rod portion 3a inserted into the insertion hole 2a of the movable iron core 2, and a lower valve body portion 3b sandwiching a valve body 25 formed of synthetic rubber or the like. And
A gap is provided between the rod portion 3a inserted into the insertion hole 2a and the gap between the rod portion 3a and the first spring 4a.
Is inserted. In the gap between the insertion hole 2a and the rod portion 3a, cylindrical spring supports 5, 6 for vertically supporting the first spring 4 are fitted at both ends of the first spring 4. The spring receivers 5, 6 are positioned by pins 7, 8, respectively.

The spring receiver 5 located above is provided with a valve rod 3
Is positioned by a pin 7 which is fixed vertically. On the other hand, the spring receiver 6 located below is positioned by a pin 8 which vertically penetrates the movable iron core 2 and the valve stem 3. However, although this pin 8 is fixed to the movable iron core 2, the pin 8 is free in a through hole 3 c having a size larger than the diameter of the pin 8 formed in the rod portion 3 a. Through. Accordingly, a gap having a dimension of S1 is generated between the pin 8 and the valve stem 3 in the vertical direction. Further, a flange 3d is formed on the outside at the lower end of the valve stem 3 forming the valve body 3b, and a second spring 9 which supports the valve body 25 with the guide pipe 14 is provided therewith. The valve stem 3 is fitted so as to urge the valve stem 3 downward so as to abut against the valve stem 3.

Next, the operation of the solenoid valve 1 having such a structure will be described. First, when the coil 12 shown in FIG. 1 is not energized, the valve rod 3 is urged downward by the elastic expansion force of the second spring 9, and the valve element 2 held by the valve rod 3
5 is closed with the valve 5 in contact with the valve seat 24. Therefore, the flow of the fluid flowing into the body 21 from the input port 22 is cut off, and the fluid does not flow out from the output port 23. At the time of such non-energization, the second spring 9
However, the first spring 4 urges the movable iron core 2 downward through the pin 8 while urging the valve stem 3 downward. Therefore, the pin 8 is in contact with the lower side of the through hole 3c of the valve stem 3, and a gap having the dimension S1 is generated on the upper side. In addition, a gap having a dimension St is formed between the movable core 2 and the fixed core 15.

Here, FIG. 5 shows the relationship between the distance (stroke) between the fixed core 15 and the movable core 2 and the suction force generated between the fixed core 15 and the movable core 2 (graph A) and the valve. FIG. 9 is a diagram showing a relationship (graph B) between the bar 3 and a load applied to the valve seat 24 in the direction of the bar 3. The load applied to the valve rod 3 is mainly caused by the urging force of the second spring 9 and the valve body 25.
Is the fluid pressure that is brought into airtight contact with So, coil 1
When electricity is supplied to the fixed core 15, the magnetic field generated in the vertical direction of the fixed core 15 causes the fixed core 15 to become an electromagnet, and an attractive force for attracting the movable core 2 is generated. At this time, in the valve closed state shown in FIG. 1, as can be seen from FIG.
The load applied to the valve stem 3 is larger than the suction force generated by energization of the valve 2 (point P).

However, in the solenoid valve 1 of the present embodiment, only the movable iron core 2 is separated from the valve rod 3 by the distance S1 of the gap formed in the through hole 3c in the initial stage of the suction with such a small suction force. It is sucked and moved. Therefore, the movable iron core 2 attracted by the fixed iron core 15 rises against the elastic expansion force of the first spring 4 received via the pin 8. On the other hand, the stem 3
The downward biasing force and the fluid pressure of the second spring 9 exerted on the flange 3d maintain the valve body 25 in the closed state in which the valve body 25 is in contact with the valve seat 24 (FIG. 2).

As shown in FIG. 2, when the movable core 2 rises by S1 in the valve-closed state, and the distance between the fixed core 15 and the movable core 2 becomes St-S1, FIG. As described above, the suction force generated in the fixed iron core 15 exceeds the load applied to the valve rod 3 (point R). Therefore, the dimension S1 of the gap provided in the through hole 3c needs to take into consideration the load of the second spring 9 due to the spring force and the fluid pressure and the stroke St of the movable iron core 2. In the solenoid valve 1 of the present embodiment, S1 = 0.4 mm and St = 0.85 mm. Therefore, a load applied to the valve stem 3 via the pin 8 is applied to the movable core 2 raised by S1.
Since the suction force for raising the movable iron core 2 is large, the movable iron core 2 and the valve stem 3 rise integrally. At this time, when fluid flows into the output port 23 at the moment when the valve body 25 rises and separates from the valve seat 24, the fluid pressure is applied to the lower end surface of the valve rod 3 as upward pressure, and is applied to the valve rod 3. The load suddenly drops (point Q).

The movable iron core 2 and the valve stem 3 which are attracted by the fixed iron core 15 and rise as a unit are composed of the movable iron core 2 and the fixed iron core 15.
, And the force is applied upward, while the valve rod 3 is applied downward by the second spring 9.
The pin 8 and the through hole 3c move in a relationship where a gap S1 is provided below the pin 8. Then, in such a state, the movable iron core 2 comes into contact with the fixed iron core 15 (FIG. 3). The valve body 25 and the valve seat 24 at the moment when the movable core 2 abuts against the fixed core 15
Is St-S1. And movable iron core 2
Is fixed by suction at a position in contact with the fixed iron core 15, so that at the next moment, the valve stem 3 rises by the gap S <b> 1 of the through hole 3 c due to the elastic expansion force of the first spring 4. Therefore, finally, the valve body 25 and the valve seat 24 are opened with a distance of St (FIG. 4). On the other hand, when the energization of the coil 12 is stopped, the movable iron core 2 and the valve rod 3 descend while keeping the state shown in FIG. 4, and the valve body 25 comes into contact with the valve seat 24 to be in a closed state.

As described above, according to the solenoid valve 1 of the present embodiment having such a configuration, first, the fixed core 15 and the movable core 2
In the initial state of attraction, where and are most distant from each other, the load applied to the attraction force of the fixed iron core 15 generated by the energization of the coil 12 is only the first spring 4, so that the voltage applied to the coil 12 may be very small. It has become possible to provide energy-saving products by reducing the amount of electricity.
Here, the solenoid valve 71 of the first conventional example shown in FIG.
As a result, a result as shown in FIG. 6 was obtained. That is, in the conventional solenoid valve 71, since the fixed iron core and the movable iron core at a stretch attract the movable iron core loaded with the spring 59 from the initial suction, the large power is used to increase the initial attractive force. Needed. Therefore,
As the fluid pressure is increased, the load applied to the armature core is also increased, so that the operating voltage to the coil is also increased, and as shown in the figure, the value of the operating voltage sharply increases in proportion to the increase in the fluid pressure. . On the other hand, in the solenoid valve 1 of the present embodiment, the influence of the fluid pressure is extremely small, and it is sufficient to suck the fluid against the urging force of the first spring 4. It could be much smaller.

Further, in the solenoid valve 1 of the present embodiment, after the movable core 2 is lifted by the initial suction, the valve stem 3 is pulled up to the movable core 2 via the pin 8, so that the first spring 4 Since the load applied on the solenoid valve is small and "wear" and "sag" are very small, the solenoid valve 1
The service life of itself has improved.

Further, in the solenoid valve 1 of the present embodiment, the first spring 4 is fitted between the movable iron core 2 and the valve rod 3, while the second spring 9 is further arranged around the valve body portion 3b. Since the movable valve core 2 and the valve rod 3 are located at the same height, the solenoid valve 1 can be made compact by eliminating unnecessary space in the axial direction space. Further, since the second spring 9 is disposed directly on the flange 3d formed at the lower end of the valve stem 3, and the urging force causes the valve body 25 to abut on the valve seat 24.
By repeating stable contact and separation of the valve body 25 to and from the valve seat 24, stable sealing performance can be maintained.

The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention. For example, in the above embodiment,
Although the valve stem 3 is configured to be inserted into the insertion hole of the movable core 2, the movable core 2 may alternatively be inserted into an insertion hole formed in the valve stem 3.

[0030]

According to the present invention, a valve stem having the valve element at the lower end and one of a movable iron core and a valve stem are inserted into an insertion hole formed by opening to the other. A first biasing member inserted between the movable iron core and the valve stem; and a first biasing member fixed to the movable iron core and loosely fitted to the valve stem via a predetermined gap. A support member for supporting the lower end of
Since it is configured to have the second urging member for urging the valve stem in the valve seat direction, it is possible to provide a high-pressure fluid control with a small amount of electric power, a long life, and a compact solenoid valve. It became.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a solenoid valve according to the present invention when the valve is closed.

FIG. 2 is a cross-sectional view of the solenoid valve according to the embodiment of the present invention at an initial stage of suction.

FIG. 3 is a cross-sectional view showing one embodiment of the solenoid valve according to the present invention when the valve is opened.

FIG. 4 is a cross-sectional view of the solenoid valve according to the embodiment of the present invention when fully opened.

FIG. 5 shows the distance between the fixed core 15 and the movable core 2;
Relationship with suction force required to suck both (graph A)
FIG. 7 is a diagram showing a relationship (graph B) with a load acting on a valve body 25 in a direction toward a valve seat 24.

FIG. 6 is a diagram showing a graph of a relationship between a fluid pressure and an operating voltage required for suction of a movable iron core.

FIG. 7 is a sectional view showing a solenoid valve of a first conventional example.

FIG. 8 is a sectional view showing a solenoid valve according to a second conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Movable iron core 3 Valve rod 4 1st spring 5, 6 Spring receiver 7, 8 pin 9 2nd spring 15 Fixed iron core 24 Valve seat 25 Valve body

Claims (2)

[Claims] 1. A fixed iron core fixedly provided on a solenoid portion around which a conductive coil is wound, and a movable iron core attracted to the fixed iron core by an electromagnetic force generated in the fixed iron core by energizing the solenoid portion. A solenoid valve having a valve mechanism that performs an opening and closing operation by contacting or separating a valve body and a valve seat that are interlocked with the movement of a movable iron core sucked by the fixed iron core, wherein a valve stem having the valve body at a lower end thereof One of the movable iron core and the valve stem is inserted into an insertion hole formed by opening to the other side, and is inserted between the movable iron core and the valve stem within the insertion hole. 1 urging member, a supporting member fixed to the movable iron core, and supporting a lower end of the first urging member loosely fitted to the valve stem via a predetermined gap, and the valve stem. Having a second biasing member for biasing in the valve seat direction. Characteristic solenoid valve. 2. The electromagnetic valve according to claim 1, wherein the support member vertically penetrates a shaft core, and a fitting hole of the same diameter formed in the movable iron core and vertically penetrates the shaft core. An electromagnetic valve, comprising: a pin disposed through a wide-diameter fitting hole formed in the valve stem.