JP2008303961A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve having improved assembly workability while maintaining assembling accuracy. <P>SOLUTION: The solenoid valve 10 comprises a stator core 42 to constitute part of a magnetic circuit when energizing an electromagnetic coil 41, a plunger 50 slidably supported in the stator core 42 so as to be driven to one axial side by magnetic attraction force generated between the stator core 42 and itself, a valve sleeve 70 mounted on the stator core 42, and a spool 80 slidably guided and supported by the valve sleeve 70 so as to be operated in response to the movement of the plunger 50. The electromagnetic coil 41 is molded integrally with the stator core 42 via an insulating layer 47. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic valve that operates a spool by movement of a plunger according to a current supplied to a coil.

  Conventionally, as a technique related to an electromagnetic valve that operates a spool by movement of a plunger according to a current supplied to a coil, an electromagnetic drive device shown in Patent Document 1 is known. This electromagnetic drive device is constituted by a stator, which is constituted by a plunger, an accommodating portion that accommodates and supports the plunger so as to be reciprocally movable, and a suction portion that attracts the plunger by supplying current to the coil, and a yoke. Magnetic flux is passed through the magnetic circuit. Thereby, a magnetic attraction force is generated between the suction portion and the plunger, and the plunger moves the spool in the anti-linear solenoid direction according to the magnetic attraction force, whereby the amount of hydraulic oil is controlled and the hydraulic oil is controlled. The hydraulic pressure is adjusted.

Further, when the current value supplied to the coil increases and reaches a predetermined value of 40% or more and 60% or less of the maximum current value, any one of the plunger, the accommodating portion, and the attracting portion is set to be magnetically saturated. For this reason, since magnetic saturation occurs at a predetermined value of 60% or less of the maximum current value while ensuring a predetermined magnetic attraction force, even when the plunger is eccentric with respect to the storage portion, the space between the storage portion and the plunger The upper limit value of the radial magnetic attractive force acting on the sliding portion is reduced, and the upper limit value of the sliding resistance acting between the housing portion and the plunger is reduced. Thereby, the hysteresis of the reciprocating position of the plunger with respect to the current value supplied to the coil is reduced.
JP 2002-222710 A

  By the way, after the above-described coil is molded by resin, it is fixed by a yoke and a stator core that constitute a part of the magnetic circuit. A thin portion as a magnetoresistive portion that reduces leakage of magnetic flux between the storage portion and the suction portion is formed between the storage portion and the suction portion in the vicinity of the plunger edge of the stator core. .

  In order to suppress the leakage of magnetic flux between the housing portion and the suction portion and increase the magnetic attraction force between the suction portion and the plunger, it is necessary to reduce the thickness of the thin portion. However, if the thickness of this thin part is made too thin, the rigidity of the stator core will be reduced, and the stator core will be deformed when the solenoid part having the coil and the stator core is assembled to the spool part having the spool, etc. There arises a problem that the coaxiality between the deformed stator core and the plunger is deteriorated.

  On the other hand, instead of providing a thin portion in the stator core, the housing portion and the suction portion are separated from each other by providing the stator core housing portion and the suction portion separately and providing a separate member as a magnetic shielding portion between the housing portion and the suction portion. Magnetic flux leakage between the suction portion and the plunger is increased. However, another problem arises that the number of parts increases and assembly workability becomes difficult.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electromagnetic valve capable of improving assembly workability while maintaining assembly accuracy.

  In order to achieve the above object, in the solenoid valve according to claim 1, the stator core (42) constituting a part of the magnetic circuit by energization of the coil (41), and sliding in the stator core. A plunger (50) that is freely supported and driven to one side in the axial direction by a magnetic attraction generated between the stator core, a valve sleeve (70) attached to the stator core, and slidable on the valve sleeve And a spool (80) that is guided and supported to operate according to the movement of the plunger, wherein the coil is formed integrally with the stator core via an insulating layer (47). Characteristic.

In the first aspect of the present invention, the coil is integrally formed with the stator core and the insulating layer constituting a part of the magnetic circuit by energizing the coil.
For this reason, for example, the work of assembling the stator core or the like after the coil is wound around the bobbin is abolished and the assembling workability is improved, and the rigidity can be increased as compared with the case of the stator core alone. As a result, even if, for example, a thin portion or the like as a magnetic resistance portion that increases the magnetic attractive force is formed on the stator core, deformation of the stator core can be suppressed, and the coaxiality between the stator core and the plunger is not deteriorated. Assembly accuracy can be maintained.

In addition, since the coil and the stator core are integrally formed with a relatively high rigidity material such as a magnetic material, for example, the rigidity is higher than when the coil and the stator core are integrally formed with a resin material that is a relatively low rigidity material. Can be increased. At this time, for example, an insulating layer subjected to an insulating process by Teflon (registered trademark) is provided between the coil and the stator core, so that an insulation failure does not occur between the coil and the stator core.
Therefore, assembly workability can be improved while maintaining the assembly accuracy.

In a second aspect of the invention, a portion of the stator core that is close to the spool-side plunger is provided with a thin portion that reduces the magnetic path cross-sectional area of the magnetic circuit.
By molding the coil and the stator core integrally, the rigidity becomes higher than that of the stator core alone, so that the thin portion that reduces the magnetic path cross-sectional area in the magnetic circuit can be made thinner. Thereby, the leakage of the magnetic flux in a thin part is suppressed and the magnetic attraction force between a stator core and a plunger can be increased.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of a solenoid valve 10 according to the present embodiment. FIG. 2 is a cross-sectional view showing a detailed shape of the thin portion 45 of the stator core 42 of FIG.
The electromagnetic valve 10 is used for hydraulic control in an automatic transmission of a vehicle, and includes a solenoid unit 20 and a spool unit 60 provided at one end of the solenoid unit 20. The solenoid unit 20 includes a bottomed cylindrical cover 30 formed of a magnetic material, a coil-integrated stator 40 having a stator core 42 formed of an electromagnetic coil 41 and a magnetic material, and magnetic attraction generated between the stator core 42. A plunger 50 or the like that is driven in one axial direction by force is provided, and the spool portion 60 includes a valve sleeve 70 and a spool 80 or the like.

  The coil-integrated stator 40 is accommodated in the cover 30 by fitting the outer periphery of the flange portion 43 to the bottom portion of the cover 30 and fitting the outer periphery of the annular suction portion 46 to the opening end of the cover 30. Yes. In the coil-integrated stator 40, the electromagnetic coil 41 and the stator core 42 are integrally formed so as to cover the portions other than the outer peripheral side of the electromagnetic coil 41 with the flange portion 43, the cylindrical portion 44, the thin portion 45, and the suction portion 46 of the stator core 42. Has been. At that time, an insulating layer 47 is formed on the surfaces of the flange portion 43, the cylindrical portion 44, the thin portion 45, and the suction portion 46 on the electromagnetic coil 41 side by an insulating process using Teflon (registered trademark) or the like.

  By energizing the electromagnetic coil 41, a magnetic circuit is configured by the cover 30, the flange portion 43, the cylindrical portion 44 and the suction portion 46 of the stator core 42, and the plunger 50. The thin-walled portion 45 serves as a magnetoresistive portion that reduces magnetic flux leakage between the cylindrical portion 44 and the attracting portion 46 and increases the magnetic attracting force between the attracting portion 46 and the plunger 50 in the magnetic circuit. (See FIG. 2).

  The stator core 42 is formed with an inner peripheral hole 48 slightly larger than the outer diameter of the plunger 50 on the non-spool side and an inner peripheral hole 49 smaller than the inner peripheral hole 48 on the spool side. The plunger 50 is coaxial and is slidably inserted. The depth of the inner peripheral hole 48 is set slightly larger than the stroke required for the plunger 50.

  A valve sleeve 70 for slidably fitting the spool 80 is disposed on the outer surface of the suction portion 46 located on the opening end side of the cover 30. Then, the solenoid portion 20 is attached to the valve sleeve 70 by caulking the opening-side cylindrical end portion 31 of the cover 30 in a state where the flange portion 71 formed on the valve sleeve 70 and the suction portion 46 are joined. They are joined together. Accordingly, the coil-integrated stator 40 housed in the cover 30 is fixed in the axial direction between the bottom portion of the cover 30 and the flange portion 71 of the valve sleeve 70.

  The valve sleeve 70 is formed with a first valve hole 72 and a second valve hole 73 having different diameters, and a spring accommodating hole 74 connected to the second valve hole 73. Each of the valve holes 72 and 73 and the spring accommodation hole 74 are formed so as to extend coaxially with the stator core 42 and the plunger 50.

  The spool 80 is provided with a first land portion 81 and a second land portion 82 that respectively fit into the first valve hole 72, and a third land portion 83 that fits into the second valve hole 73. The land portion 82 and the third land portion 83 are provided adjacent to each other.

  The first land portion 81 and the second land portion 82 are provided apart from each other by a predetermined amount in the axial direction, and are connected to each other by a small diameter portion 84. An annular groove 75 is formed in the valve sleeve 70 corresponding to the small diameter portion 84, and an output port 76 for outputting a control pressure is communicated with the annular groove 75.

  Further, the valve sleeve 70 is formed with a discharge port 77 and a supply port 78 that open corresponding to the end surfaces of the first land portion 81 and the second land portion 82 facing each other. Further, a drain port 79 that opens to the spring accommodating hole 74 is formed in the valve sleeve 70. At one end of the spool 80, a shaft portion 85 that protrudes through the inner peripheral hole 49 of the stator core 42 and contacts the plunger 50 is provided.

  The open end of the spring accommodating hole 74 is closed by a plug 90 that is screwed into a screw hole formed on the inner peripheral surface thereof, and a spring 91 is provided between the plug 90 and the spool 80. The spool 80 is pressed toward the plunger 50 by the urging force of the spring 91, whereby the plunger 50 is held at the initial position where it abuts against the bottom surface of the normal cover 30 via the shaft portion 85 of the spool 80. At the initial position of the plunger 50, the spool-side edge of the plunger 50 is disposed so as to substantially coincide with the thin portion 45 of the stator core 42 in the axial direction (see FIG. 1).

  The operation of the electromagnetic valve 10 according to this embodiment configured as described above will be described below. When the electromagnetic coil 41 is in a non-excited state, the spool 80 presses the plunger 50 in the anti-spool direction by the biasing force of the spring 91 and holds the plunger 50 at an initial position where it abuts against the bottom surface of the cover 30. In this non-excited state, the output port 76 is disconnected from the supply port 78 and is also connected to the discharge port 77, whereby the output port 76 is kept at a low pressure.

  On the other hand, when the electromagnetic coil 41 is energized and excited, a magnetic circuit is configured by the cover 30, the flange portion 43 of the stator core 42, the cylindrical portion 44 and the suction portion 46, and the plunger 50. Magnetic attractive force is generated during By this magnetic attraction force, the plunger 50 is attracted to the attraction portion 46 side, and the spool 80 moves in the anti-plunger direction against the biasing force of the spring 91. By this movement, the second land portion 82 starts to open the supply port 78 and the first land portion 81 starts to limit the opening area of the discharge port 77, so that the control pressure of the output port 76 is gradually increased.

  As described above, in the electromagnetic valve 10 according to the present embodiment, the magnetic attraction force that the attraction portion 46 of the stator core 42 attracts the plunger 50 in accordance with the current value supplied to the electromagnetic coil 41 and the urging force of the spring 91 are balanced. The spool 80 is held at a position where the electromagnetic coil 41 is operated, whereby the control pressure is controlled to a pressure corresponding to the current value supplied to the electromagnetic coil 41.

As described above, in the electromagnetic valve 10 according to the present embodiment, the electromagnetic coil 41 is integrally formed through the stator core 42 and the insulating layer 47 constituting a part of the magnetic circuit by energizing the electromagnetic coil 41. ing.
For this reason, for example, the work of assembling to the stator core 42 and the like after the electromagnetic coil 41 is wound around the bobbin is abolished and the workability of the assembly is improved. Can be increased. Accordingly, even if the stator core 42 is formed with, for example, a thin portion 45 as a magnetic resistance portion that increases the magnetic attractive force, the deformation of the stator core 42 can be suppressed, and the coaxiality between the stator core 42 and the plunger 50 can be suppressed. Assembling accuracy can be maintained without deteriorating.

Further, in order to integrally mold the electromagnetic coil 41 and the stator core 42 with a relatively high rigidity material such as a magnetic material, for example, the electromagnetic coil 41 and the stator core 42 are integrally molded with a resin material having a relatively low rigidity. Compared with the case, the rigidity of the coil integrated stator 40 can be increased. At this time, since the insulating layer 47 is provided between the electromagnetic coil 41 and the stator core 42, insulation failure does not occur between the electromagnetic coil 41 and the stator core 42.
Therefore, assembly workability can be improved while maintaining the assembly accuracy.

  Further, in the electromagnetic valve 10 according to the present embodiment, a thin portion 45 that reduces a magnetic path cross-sectional area in the magnetic circuit is provided in a portion of the stator core 42 that is close to the spool-side plunger 50.

  By integrally molding the electromagnetic coil 41 and the stator core 42, the rigidity of the coil-integrated stator 40 becomes higher than that of the stator core 42 alone, so that the thin portion 45 that reduces the magnetic path cross-sectional area in the magnetic circuit is made thinner. can do. Thereby, the leakage of the magnetic flux in the thin part 45 is suppressed, and the magnetic attraction force between the stator core 42 and the plunger 50 can be increased.

It is sectional drawing which shows the structure outline | summary of the solenoid valve which concerns on this embodiment. It is sectional drawing which shows the detailed shape of the thin part of the stator of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Solenoid valve 20 ... Solenoid part 40 ... Coil-integrated stator 41 ... Electromagnetic coil 42 ... Stator core 43 ... Flange part 44 ... Cylindrical part 45 ... Thin part 46 ... Suction part 47 ... Insulating layer 50 ... Plunger 60 ... Spool part 70 ... Valve sleeve 80 ... Spool

Claims (2)

A stator core that forms part of the magnetic circuit by energizing the coil;
A plunger that is slidably supported in the stator core and driven to one side in the axial direction by a magnetic attractive force generated between the stator core;
A valve sleeve attached to the stator core;
A spool that is slidably guided and supported by the valve sleeve and operates according to the movement of the plunger;
A solenoid valve comprising:
The solenoid valve according to claim 1, wherein the coil is formed integrally with the stator core via an insulating layer.   2. The solenoid valve according to claim 1, wherein a portion of the stator core adjacent to the plunger on the spool side is provided with a thin portion that reduces a cross-sectional area of a magnetic path in the magnetic circuit.

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