JP2009174623A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve capable of preventing deterioration of magnetic properties. <P>SOLUTION: A plunger 24 is slidably supported through its outer peripheral surfaces 25b, 26a by a resin coating 42 of a counter-spool side bush 40 and a support part 51 of a spool side bush 50. The counter-spool side bush 40 is located between the counter-spool side outer peripheral surface (the outer peripheral surface 25b of a plunger body 25) of the plunger 24 and the inner peripheral surface 34 of a yoke portion 31. The spool side bush 50 is located between the spool side outer peripheral surface (the outer peripheral surface 26a of a shaft 26) of the plunger 24 and the inner peripheral surface 35 of a core portion 32. <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.

2. Description of the Related Art Conventionally, an electromagnetic valve device shown in Patent Document 1 is known as an electromagnetic valve that operates a spool by movement of a plunger in accordance with a current supplied to a coil. This electromagnetic valve device supplies a current to the coil to cause a magnetic flux to flow in a magnetic circuit constituted by a yoke, a housing portion, a suction portion, and a plunger. Thereby, a magnetic attraction force is generated between the attraction unit and the plunger. At this time, the value of the current supplied to the coil is controlled to adjust the force with which the plunger pushes the spool in the anti-linear solenoid direction, and the hydraulic pressure of the hydraulic oil flowing out from the output port is adjusted.
JP 2002-310322 A

  By the way, the outer peripheral surface of the plunger and the inner peripheral surface of the accommodating portion for accommodating the plunger are subjected to surface treatment such as plating or nitriding with a non-magnetic material of nickel / phosphorus. Accordingly, the plunger is supported by the housing portion so that the plunger can smoothly slide in the stator core without being attracted to the stator core having the yoke, the housing portion, and the suction portion.

  However, for example, when the nitriding process is performed on the stator core, nitrogen may become an impurity and the magnetic characteristics (magnetic hysteresis) may be deteriorated. In this case, there is a problem that the hysteresis is increased. Further, since the surface treatment is applied to the plunger and the stator core, it is an impediment to cost reduction.

  Further, the plunger is pressed against and supported by the stator core on the outer peripheral surface of the spool by the radial magnetic attractive force generated between the spool side end of the plunger and the attraction portion of the stator core. As described above, since the plunger is supported only by the outer peripheral surface of the spool, there is a problem that when the magnetic attractive force is increased, the plunger is poorly slid (large hysteresis).

  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 preventing deterioration of magnetic characteristics. Another object is to provide an electromagnetic valve that can prevent poor sliding of the plunger.

  In order to achieve the above object, in the electromagnetic valve according to claim 1, the yoke portion (31) and the core portion (32) that constitute a part of the magnetic circuit by energizing the coil (22) A stator core (23) having a stator core that reduces a magnetic path cross-sectional area in the magnetic circuit by a thin-walled portion (33) that connects the yoke portion and the core portion, and disposed in the stator core. A plunger (24) that moves in the axial direction by a magnetic attractive force generated between the valve, a valve sleeve (70) that is attached to the stator core, and is slidably guided and supported by the valve sleeve to move the plunger. A solenoid valve (10) that operates in response to the spool (80), the non-spool side outer peripheral surface (25b) of the plunger and the inner peripheral surface (34) of the yoke portion. Between the resin member (42) on the inner peripheral side of the first bush (40) disposed between the outer peripheral surface (26a) of the plunger and the inner peripheral surface (35) of the core portion. A technical feature is that the outer peripheral surface of the plunger is slidably supported by the resin member (51) on the inner peripheral side of the second bush (50) disposed on the inner surface.

  In the first aspect of the present invention, the plunger has, on its outer peripheral surface, a resin member on the inner peripheral side of the first bush disposed between the outer surface on the side opposite to the spool of the plunger and the inner peripheral surface of the yoke portion. The plunger is slidably supported by a resin member on the inner peripheral side of the second bush disposed between the spool-side outer peripheral surface of the plunger and the inner peripheral surface of the core portion.

This eliminates the need for surface treatment such as plating or nitriding with a non-magnetic material of nickel and phosphorus on the outer peripheral surface of the plunger or the inner peripheral surface of the stator core, thereby improving the magnetic characteristics and reducing hysteresis. .
Therefore, it is possible to prevent deterioration of magnetic characteristics due to surface treatment or the like on the stator core. Further, since the surface treatment on the plunger and the stator core can be eliminated, the manufacturing cost of the stator core can be reduced.

  The plunger is slidably supported by the stator core via the first bush and the second bush on both sides in the axial direction of the non-spool side outer peripheral surface and the spool side outer peripheral surface. For this reason, the force that presses the plunger against the stator core by the magnetic attracting force in the radial direction acts on both sides of the plunger in the axial direction, and the sliding failure of the plunger can be prevented.

  In particular, the stator core is integrally formed by connecting the yoke part and the core part by a thin part, so that the yoke part and the core part are formed separately so as to face each other through a gap serving as a magnetoresistive part. Compared with the case where it is done, a coaxial degree becomes small and also the sliding failure of a plunger is suppressed.

  In the invention of claim 2, the second bush has an abutting portion that abuts on the plunger moved in the axial direction by the magnetic attractive force. Thereby, in addition to the above-described support function for slidably supporting the plunger, the second bush moves in the axial direction in accordance with the magnetic attraction force, so that the plunger is in contact with the contact portion. It is possible to provide a stopper function that restricts the movement to the position.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a schematic configuration of a solenoid valve 10 according to the present embodiment. 2A is a front view of the spool-side bush 50, and FIG. 2B is a partial cross-sectional view of the spool-side bush 50 as viewed from the side.
The solenoid valve 10 is used, for example, for oil pressure control inside an oil pan of an automatic transmission for 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 mainly includes a cover 21 formed of a magnetic material in a bottomed cylindrical shape, a coil 22, a stator core 23, a plunger 24, an anti-spool side bush 40, a spool side bush 50, and the like. Includes a valve sleeve 70 and a spool 80.

  The stator core 23 includes a yoke portion 31, a core portion 32, and a thin portion 33 that are integrally formed of a magnetic material. The stator core 23 is configured to cover the coil 22 with a yoke portion 31, a core portion 32, a thin portion 33, and a groove portion 27 fitted to the outer periphery of the yoke portion 31 on the side opposite to the spool. The stator core 23 is accommodated in the cover 21 by fitting the outer periphery of the groove portion 27 fitted to the yoke portion 31 to the bottom portion of the cover 21 and fitting the outer periphery of the core portion 32 to the opening end of the cover 21. Has been.

  By energizing the coil 22, a magnetic circuit is configured by the cover 21, the yoke portion 31 and the core portion 32 of the stator core 23, and the plunger 24. The thin-walled portion 33 serves as a magnetoresistive portion that reduces magnetic flux leakage between the yoke portion 31 and the core portion 32 and increases the magnetic attractive force between the core portion 32 and the plunger 24 in the magnetic circuit. (See FIG. 1).

  The stator core 23 is formed with a yoke portion side inner peripheral hole having an inner peripheral surface 34 on the yoke portion 31 side and a core portion side inner peripheral hole having an inner peripheral surface 35 on the core portion 32 side. The inner diameter of the side inner peripheral hole is formed to be larger than the inner diameter of the core side inner peripheral hole.

  The anti-spool-side bush 40 includes a bush body 41 formed of a magnetic material, for example, a cold rolled steel plate such as SPCC in a ring shape, and a Teflon (registered trademark) or the like is provided on the inner peripheral side of the bush body 41. Thus, the resin film 42 is formed. The axial length of the anti-spool side bush 40 is set to be longer than the stroke required for the plunger 24. The inner diameter of the non-spool side bush 40 is set to be slightly smaller than the inner diameter of the yoke portion side inner peripheral hole. The anti-spool side bush 40 is fitted to a step portion 36 formed on the anti-spool side of the inner peripheral surface 34 of the stator core 23 on the outer peripheral surface of the bush main body 41 (see FIG. 1).

  As shown in FIG. 2, the spool-side bush 50 integrally includes a substantially cylindrical support portion 51 made of a resin material such as polypropylene resin and a substantially cylindrical contact portion 52 having an outer diameter larger than that of the support portion 51. I have. When the spool-side bush 50 is assembled to the stator core 23 and the plunger 24 as will be described later, the anti-spool side and the spool side of the spool-side bush 50 are connected to the support portion 51 and the contact portion 52 to provide an oil passage. Four grooves 51a and 52a are formed for securing each of the grooves. In the spool-side bush 50, the outer peripheral surface of the support portion 51 is fitted to the inner peripheral surface 35, and the spool side surface of the contact portion 52 is in contact with the step portion 37 between the inner peripheral surface 34 and the inner peripheral surface 35. It is fixed in the stator core 23 (see FIG. 1).

  The axial length of the abutment portion 52 abuts against the abutment portion 52 when the plunger 24 that moves to the spool side against a biasing force of a spring 91 described later by a magnetic attraction force exceeds the normal movement range. Is set to Thereby, the contact part 52 is provided with a stopper function that restricts the plunger 24 moved to the spool side by the magnetic attractive force to movement to a predetermined position.

  The plunger 24 includes a plunger main body 25 made of a magnetic material and a shaft 26 made of a magnetic material fitted into a hole 25a formed coaxially at the spool side end of the plunger main body 25. The shaft 26 protrudes from the plunger body 25 to the spool side.

  The outer peripheral surface 25 b of the plunger main body 25, that is, the outer peripheral surface on the non-spool side of the plunger 24 is slidably supported by the resin coating 42 of the anti-spool side bush 40. The outer peripheral surface 26 a of the shaft 26, that is, the spool-side outer peripheral surface of the plunger 24 is slidably supported by the support portion 51 of the spool-side bush 50. As a result, the plunger 24 is coaxially and slidably supported in the stator core 23.

  The plunger 24 moves in the axial direction (spool side) close to the core portion 32 by a magnetic attractive force generated between the plunger main body 25 and the core portion 32 of the stator core 23.

  By configuring the solenoid unit 20 in this way, a magnetic circuit is configured with the cover 21, the stator core 23, and the plunger 24 in response to energization of the coil 22. At this time, since the resin film 42 is formed on the inner peripheral surface of the anti-spool side bush 40 that slidably supports the plunger body 25 of the plunger 24, the yoke portion of the stator core 23 is interposed via the anti-spool side bush 40. Magnetic flux does not leak between 31 and the plunger body 25 of the plunger 24. Further, since the support portion 51 of the spool-side bush 50 that slidably supports the shaft 26 of the plunger 24 is formed of a resin material, the core portion 32 of the stator core 23 and the plunger 24 are interposed via the spool-side bush 50. Magnetic flux does not leak between them.

  A valve sleeve 70 for slidably fitting the spool 80 is disposed on the outer surface of the core portion 32 located on the opening end side of the cover 21. And the solenoid part 20 and the spool part 60 are united by crimping the opening side cylindrical end part 21a of the cover 21 in the state which joined the flange part 71 and the core part 32 which were formed in the valve sleeve 70. FIG. Are combined.

  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. These valve holes 72 and 73 and the spring accommodating hole 74 are formed so as to extend coaxially with the stator core 23 and the plunger 24.

  The spool 80 is provided with a first land portion 81 and a second land portion 82 that fit into the first valve hole 72, and a third land portion 83 that fits into the second valve hole 73. The part 82 and the third land part 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. A shaft portion 85 that protrudes from one end of the spool 80 and abuts against the spool side end surface of the shaft 26 of the plunger 24 protrudes.

  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 24 by the urging force of the spring 91, so that the plunger 24 is held at the initial position where it abuts against the bottom surface of the normal cover 21 via the shaft portion 85 of the spool 80. At the initial position of the plunger 24, the spool side end edge of the plunger 24 is disposed so as to substantially coincide with the end of the core portion 32 in the axial direction (see FIG. 1).

  The operation of the electromagnetic valve 10 according to the first embodiment configured as described above will be described below. When the coil 22 is in a non-excited state, the spool 80 presses the plunger 24 in the anti-spool direction by the urging force of the spring 91 and holds the plunger 24 at an initial position where it abuts against the bottom surface of the cover 21. 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 coil 22 is energized and excited, a magnetic circuit is formed by the cover 21, the stator core 23, and the plunger 24, and a magnetic attractive force is generated between the core portion 32 of the stator core 23 and the plunger main body 25 of the plunger 24. To do. The plunger main body 25 is pulled toward the core portion 32 by the magnetic attractive force, 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 first embodiment, the magnetic attractive force generated between the core portion 32 of the stator core 23 and the plunger main body 25 of the plunger 24 according to the current value supplied to the coil 22; The spool 80 is held at a position where the urging force of the spring 91 is balanced, whereby the control pressure is controlled to a pressure corresponding to the current value supplied to the coil 22.

  As described above, in the solenoid valve 10 according to the first embodiment, the plunger 24 has the outer peripheral surfaces 25b and 26a, the outer peripheral surface on the side opposite to the spool of the plunger 24 (the outer peripheral surface 25b of the plunger main body 25). Between the inner peripheral surface 34 of the yoke portion 31 and the resin coating 42 of the anti-spool-side bush 40, the outer peripheral surface of the plunger 24 on the spool side (the outer peripheral surface 26 a of the shaft 26), and the core portion 32. It is slidably supported by a support portion 51 of a spool-side bush 50 arranged between the peripheral surface 35.

This eliminates the need to subject the outer peripheral surfaces 25b, 26a of the plunger 24 and the inner peripheral surfaces 34, 35 of the stator core 23 to surface treatment such as plating or nitriding with a non-magnetic material of nickel / phosphorus, thereby improving the magnetic characteristics. Hysteresis can be reduced.
Therefore, it is possible to prevent deterioration of magnetic characteristics due to surface treatment or the like on the stator core 23. Moreover, since the surface treatment to the plunger 24 and the stator core 23 can be abolished, the manufacturing cost of the stator core 23 can be reduced.

  In addition, the plunger 24 passes through the anti-spool-side bush 40 and the spool-side bush 50 in the axial direction of the outer peripheral surface 25b of the plunger main body 25 that is the anti-spool side outer peripheral surface and the outer peripheral surface 26a of the shaft 26 that is the spool-side outer peripheral surface. The stator core 23 is slidably supported on both sides. For this reason, the force that presses the plunger 24 against the stator core 23 by the magnetic attracting force in the radial direction acts on both sides of the plunger 24 in the axial direction, and the sliding failure of the plunger 24 can be prevented.

  In particular, since the stator core 23 is integrally formed by connecting the yoke portion 31 and the core portion 32 by the thin portion 33, the yoke portion and the core portion are opposed to each other with a gap serving as a magnetoresistive portion. Compared with the case where it is formed as a separate body, the coaxiality is reduced, and the sliding failure of the plunger 24 is further suppressed.

  Further, in the solenoid valve 10 according to the first embodiment, the spool-side bush 50 has the contact portion 52 that contacts the spool-side end portion of the plunger main body 25 of the plunger 24 moved in the axial direction by the magnetic attractive force. Thus, in addition to the above-described support function for slidably supporting the shaft 26 of the plunger 24, the spool-side bush 50 receives the plunger main body 25 moved in the axial direction according to the magnetic attractive force against the contact portion 52. It can also be provided with a stopper function for restricting the plunger 24 to movement to a predetermined position by contact.

  Furthermore, in the electromagnetic valve 10 according to the first embodiment, the shaft 26 of the plunger 24 is slidably supported by the spool-side bush 50 made of a resin material. Magnetic flux does not leak. Therefore, an inexpensive magnetic material can be used for the shaft 26 without using an expensive nonmagnetic material.

In addition, this invention is not limited to the said embodiment, You may actualize as follows, and even in that case, an effect | action and effect equivalent to the said embodiment are acquired.
(1) The anti-spool side bush 40 is not limited to the resin film 42 formed on the inner peripheral surface of the bush main body 41, and may be formed in a ring shape from a resin material such as polypropylene resin.

(2) The contact portion 52 of the spool-side bush 50 is not limited to being integrally formed of the resin material together with the support portion 51, and may be formed of, for example, a nonmagnetic material.

It is sectional drawing which shows the structure outline | summary of the solenoid valve which concerns on this embodiment. 2A is a front view of the spool-side bush, and FIG. 2B is a partial cross-sectional view of the spool-side bush as viewed from the side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Solenoid valve 20 ... Solenoid part 22 ... Coil 23 ... Stator core 24 ... Plunger 25 ... Plunger main body 25b ... Outer peripheral surface 26 ... Shaft 26a ... Outer peripheral surface 31 ... Yoke part 32 ... Core part 33 ... Thin part 34, 35 ... Inner circumference Surface 40 ... Anti-spool side bush (first bush)
41 ... Bushing body 42 ... Resin coating (resin member)
50 ... Spool side bush (second bush)
51. Supporting part (resin member)
52 ... Contact part 60 ... Spool part 70 ... Valve sleeve 80 ... Spool

Claims (2)

A stator core having a yoke part and a core part that constitute a part of a magnetic circuit by energizing a coil, and a magnetic path cross-sectional area in the magnetic circuit is reduced by a thin part connecting the yoke part and the core part A stator core to be
A plunger that is arranged in the stator core and moves in an axial direction by a magnetic attractive force generated between the core portion;
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:
A resin member on the inner peripheral side of the first bush disposed between the outer peripheral surface on the side opposite to the spool of the plunger and the inner peripheral surface of the yoke portion, the outer peripheral surface on the spool side of the plunger and the inner periphery of the core portion An electromagnetic valve characterized in that an outer peripheral surface of the plunger is slidably supported by a resin member on an inner peripheral side of a second bush disposed between the two surfaces.   2. The solenoid valve according to claim 1, wherein the second bush has an abutting portion that abuts on the plunger moved in the axial direction by the magnetic attractive force.

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