JP4054932B2 - Solenoid valve for fluid pressure control - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solenoid valve for fluid pressure control that controls the pressure of a fluid such as oil.
[0002]
[Prior art]
Conventionally, a solenoid valve for controlling fluid pressure has been used in, for example, a hydraulic control device of an automatic transmission of an automobile, and an example thereof is disclosed in Japanese Utility Model Laid-Open No. 60-16076. As shown in FIG. 2, the solenoid valve of this publication is provided with a stator core 6 at the inner diameter portion of the solenoid coil 1 and a moving core 2 facing the lower side of the stator core 6 to turn on / off the energization of the solenoid coil 1. When the moving core 2 is reciprocated in the up and down direction by turning off, the valve body 3 fixed to the moving core 2 is reciprocated in the up and down direction so that the input port 4 and the output port 5 are communicated / blocked. Yes. In this case, if the oil flow path side communicates with the inner diameter side of the solenoid coil 1, magnetic foreign matters such as metal powder contained in the oil flowing in from the input port 4 are moved between the moving core 2 and the stator core 6. When entering the magnetic gap 7, magnetic foreign substances are attracted and deposited on the end surfaces of the moving core 2 and the stator core 6, and the moving core 2 (valve element 3) may not operate normally.
[0003]
Therefore, in the above publication, a seal member 9 is attached to a lower portion of a cylindrical guide member 8 that slide-supports the valve body 3, and the seal member 9 seals a gap between the valve body 3 and the guide member 8. Thus, the oil flow path side and the inner diameter side of the solenoid coil 1 are partitioned to prevent magnetic foreign matters in the oil from entering the magnetic gap 7 on the inner diameter side of the solenoid coil 1.
[0004]
[Problems to be solved by the invention]
However, in the configuration of the above publication, since the guide member 8 is disposed below the solenoid coil 1 and the seal member 9 is extended downward from the lower portion of the guide member 8, the shaft of the entire solenoid valve is provided. There is a drawback that the directional dimension becomes longer and the solenoid valve becomes larger.
[0005]
The present invention has been made in consideration of such circumstances, and therefore the object thereof is a solenoid valve for fluid pressure control that can reduce the size of the whole solenoid valve while ensuring the operation reliability of the solenoid valve. Is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a fluid pressure control electromagnetic valve according to claim 1 of the present invention has a diaphragm seal fitted on the outer periphery of a portion of the moving core protruding from the spool, and the outer periphery of the diaphragm seal. The part is sandwiched between the side surface of the spool and the holding member and fixed, and the flow path side of the fluid and the inner diameter side of the spool are partitioned by a diaphragm seal, so that magnetic foreign matter in the fluid flowing in from the input port Intrusion to the side is ensured to ensure the operational reliability of the moving core.
[0007]
In this configuration, since the flat diaphragm seal is fixed to the side surface portion of the spool by the holding member, the diaphragm seal and the holding member can be assembled compactly in the narrow space of the side surface portion of the spool, and the axial dimension of the seal structure can be increased. It can be made much smaller than before, and the entire solenoid valve can be reduced in the axial direction.
[0008]
In this case, as in claim 2, the flow path connecting the input port and the output port may be formed along the outer periphery of the solenoid coil. In this way, the solenoid coil that generates heat when energized can be efficiently cooled by the fluid flowing through the flow path, and deterioration and durability deterioration due to overheating of the solenoid valve can be prevented.
[0009]
Further, as in claim 3, the holding member is made of a magnetic material to form a component of a magnetic circuit, and the end on the inner peripheral side of the holding member is close to the outer peripheral surface of the moving core, and the outer periphery of the holding member The portion may be fixed to a coil housing that also serves as a yoke. In this way, the magnetic circuit can be made compact by using the holding member that holds the diaphragm seal, which can contribute to downsizing of the solenoid valve, reduction in the number of parts, and improvement in assembly.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to an electromagnetic valve for hydraulic control will be described with reference to FIG. A solenoid coil 13 wound around a resin spool 12 is housed in a coil housing 11 made of a magnetic material that also serves as a yoke, and a stator core 14 formed integrally with the coil housing 11 on the right inner diameter portion of the spool 12. Is fitted. Further, a nonmagnetic cover 15 made of resin or nonmagnetic metal is attached to the left opening of the coil housing 11. An oil (fluid) input port 16 is formed at the center of the nonmagnetic cover 15, and a flow path 17 communicating with the input port 16 is formed along the inner surface of the nonmagnetic cover 15.
[0011]
In the coil housing 11, a flow path 18 is formed along the outer periphery of the solenoid coil 13, and a plurality of output ports 19 communicating with the flow path 18 are formed on the right side wall of the coil housing 11. The flow path 17 on the nonmagnetic cover 15 side and the flow path 18 on the inner peripheral side of the coil housing 11 are communicated with each other by a plurality of through holes 21 formed in an end plate 20 described later.
[0012]
On the other hand, the right side of the moving core 22 made of a magnetic material is slidably fitted into the left inner diameter portion of the spool 12, and the right end surface of the moving core 22 faces the left end surface (attraction surface) of the stator core 14. Yes. A tapered valve body 23 is integrally formed at the left end of the moving core 22, and the valve body 23 opens and closes a valve seat 24 formed at the opening peripheral edge of the input port 16. Yes. Further, a spring 25 is interposed between the moving core 22 and the stator core 14, and the moving core 22 is biased leftward (valve closing direction) by the elastic force of the spring 25.
[0013]
An annular groove 26 is formed on the outer periphery of a portion of the moving core 22 that protrudes from the spool 12, and an inner peripheral end portion of a diaphragm seal 27 formed of an elastic body such as rubber is fitted into the annular groove 26. Yes. The outer peripheral portion of the diaphragm seal 27 is fitted between the inner peripheral portion of the ring-shaped convex portion 28 formed on the left side surface of the spool 12 and is between the end plate 20 (holding member) and the left side surface of the spool 12. It is sandwiched between and fixed. The diaphragm seal 27 partitions the oil flow path 17 side from the inner diameter side of the spool 12.
[0014]
The end plate 20 and the nonmagnetic cover 15 are fixed to the left edge portion of the coil housing 11 by caulking with the outer peripheral portions thereof being overlapped with each other. The end plate 20 is made of a magnetic material and becomes a component of a magnetic circuit. The moving core 22 passes through a circular hole 32 formed at the center of the end plate 20, and the end plate 20 The peripheral end surface is close to the outer peripheral surface of the moving core 22 and the outer peripheral portion of the end plate 20 is fixed to the coil housing 11 serving as a yoke as described above, so that the magnetic circuit is connected to the stator core 14 when the solenoid coil 13 is energized. ... moving core 22 ... end plate 20 ... coil housing 11 ... stator core 14 path.
[0015]
An O-ring 30 made of an elastic material such as rubber is attached to the groove 29 formed on the right side surface of the spool 12, and the O-ring 30 seals between the right side surface of the spool 12 and the right side wall of the coil housing 11. Has been.
[0016]
The solenoid valve for hydraulic control configured as described above is a normally closed solenoid valve. When the solenoid coil 13 is not energized, the moving core 22 is moved to the left by the elastic force of the spring 25, and the valve body. The portion 23 is seated on the valve seat 24 of the input port 16 and the input port 16 is closed. In this state, no oil flows from the input port 16 to the output port 19.
[0017]
On the other hand, when the solenoid coil 13 is energized, a magnetic attractive force acts between the stator core 14 and the moving core 22, and the moving core 22 is attracted to the right against the spring force of the spring 25. As a result, the valve body 23 is separated from the valve seat 24 of the input port 16 and the input port 16 is opened. In this state, oil flowing in from the input port 16 flows to the output port 19 through the flow paths 17 and 18.
[0018]
In this embodiment, since the oil flow path 17 side and the inner diameter side of the spool 12 are partitioned by the diaphragm seal 27, magnetic foreign matters such as metal powder flowing in from the input port 16 and other foreign matters are It is possible to prevent the magnetic gap between the moving core 22 and the stator core 14 and the sliding portion of the moving core 22 from entering. For this reason, the moving core 22 (valve body part 23) can be reliably operated over a long period of time, and the operation reliability of the electromagnetic valve can be improved.
[0019]
In addition, in this embodiment, since the flat diaphragm seal 27 is fixed to the side surface of the spool 12 by the flat end plate 20, the diaphragm seal 27 and the end plate 20 can be made compact in the narrow space of the side surface of the spool 12. It can be assembled, the axial dimension of the seal structure can be made significantly smaller than before, and the entire solenoid valve can be miniaturized in the axial direction.
[0020]
Further, in the present embodiment, the end plate 20 that fixes the diaphragm seal 27 is used as a constituent member of the magnetic circuit to make the magnetic circuit compact, and the moving core 22 is integrally formed with the valve body 23. Therefore, further miniaturization of the solenoid valve, reduction of the number of parts, and improvement of assembly can be realized.
[0021]
Further, in the present embodiment, the flow path 18 on the inner peripheral side of the coil housing 11 is formed along the outer periphery of the solenoid coil 13, so that the solenoid coil 13 that generates heat during pressure control is transferred to the oil flowing through the flow path 18. Therefore, it is possible to efficiently cool, and it is possible to prevent deterioration and durability deterioration due to overheating of the solenoid valve.
[0022]
The flow path 18 does not necessarily have to be formed on the entire circumference of the solenoid coil 13, and may be formed only along a part of the outer periphery of the solenoid coil 13. The cooling effect of the solenoid coil 13 can be obtained. Furthermore, the oil flow path does not necessarily have to be formed along the outer periphery of the solenoid coil 13. For example, an output port is formed in the vicinity of the nonmagnetic cover 15 on the peripheral wall of the coil housing 11, The flow path 17 on the inner surface of the magnetic cover 15 may be directly communicated with the output port. In this way, the flow path 18 on the outer periphery of the solenoid coil 13 is not necessary, and accordingly, the diameter of the coil housing 11 can be reduced, and the electromagnetic valve can be reduced in the radial direction.
[0023]
In addition, the present invention can be variously modified without departing from the gist of the invention, such as changing the shape of the moving core, diaphragm seal, end plate, etc. as appropriate, and applicable to an electromagnetic valve for controlling fluid pressure other than hydraulic pressure. Can be implemented.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a solenoid valve showing an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a conventional solenoid valve.
DESCRIPTION OF SYMBOLS 11 ... Coil housing, 12 ... Spool, 13 ... Solenoid coil, 14 ... Stator core, 15 ... Nonmagnetic cover, 16 ... Input port, 17 ... Input flow path, 18 ... Output port, 19 ... Output flow path, 20 ... End plate (Holding member), 22 ... moving core, 23 ... valve body, 24 ... valve seat, 25 ... spring, 26 ... annular groove, 27 ... diaphragm seal, 28 ... ring-shaped convex part.

Claims (3)

In a solenoid valve for fluid pressure control that communicates / blocks a fluid input port and an output port by reciprocating a moving core fitted in a spool around which a solenoid coil is wound,
A diaphragm seal fitted to an outer periphery of a portion of the moving core that protrudes from the spool, and a holding member that sandwiches and fixes an outer peripheral portion of the diaphragm seal between side surfaces of the spool, An electromagnetic valve for fluid pressure control, characterized in that a fluid flow path side and an inner diameter side of the spool are partitioned by a diaphragm seal. 2. The solenoid valve for fluid pressure control according to claim 1, wherein a flow path connecting the input port and the output port is formed along an outer periphery of the solenoid coil. The holding member is formed of a magnetic material to be a component of a magnetic circuit, an end portion on the inner peripheral side of the holding member is close to the outer peripheral surface of the moving core, and the outer peripheral portion of the holding member is a coil serving as a yoke The solenoid valve for fluid pressure control according to claim 1 or 2, wherein the solenoid valve is fixed to a housing.

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