JP2007263256A - Linear solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve hysteresis characteristics when a movable core is displaced, and to reduce manufacturing cost and weight. <P>SOLUTION: In a fixing core 38 constituting a solenoid 12, a diameter enlargement part 66 is connected to a valve body 18, and first and second recessions 68 and 70 are provided on a main body 64 extending to a movable core 36 side with respect to the diameter enlargement part 66. A through hole 56 through which a shaft 28 fitted to the movable core 36 is inserted is formed between the first and the second recessions 68 and 70 along an axial direction, and a second bearing 58 is attached to the through hole 56, and a shaft 28 is supported free to be displaced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a linear solenoid valve capable of displacing a valve body under an excitation action of a solenoid section and switching a flow state of a pressure fluid.

  2. Description of the Related Art Conventionally, an electromagnetic valve that displaces a valve body by attracting a movable iron core to a fixed iron core by an electromagnetic force generated under the excitation action of a solenoid coil has been used.

  As this type of electromagnetic valve, the present applicant has proposed an electromagnetic device capable of obtaining accurate responsiveness to the magnetic force of the movable core, as shown in Patent Document 1, for example. Further, the applicant of the present invention relates to the electromagnetic valve of Patent Document 1, and further improves the attractive force with respect to the movable core by adopting a positional relationship in which the side surface of the movable core and the inner wall surface of the housing partially overlap. The electromagnetic valve which can do this is proposed (refer patent document 2).

Registered Utility Model No. 2530268 JP 2005-286236 A

  The present invention has been made in connection with the above proposal, and provides a linear solenoid valve capable of improving the hysteresis characteristics when the movable iron core is displaced and reducing the manufacturing cost and reducing the weight. With the goal.

In order to achieve the above object, the present invention provides a linear solenoid valve that switches a communication state between one port through which a pressure fluid flows and the other port by sucking a movable iron core under the excitation action of a solenoid unit. ,
A valve body including a valve body and a housing having one and other ports through which pressure fluid flows; and
A coil provided on the housing, wound around a bobbin, a movable iron core provided to be displaceable along the axial direction, and provided between the movable iron core and the valve body, and disposed opposite to the movable iron core. And a solenoid part having a fixed iron core that attracts the movable iron core under energizing action on the coil, and a yoke that surrounds an outer peripheral surface of the movable iron core,
A valve mechanism having a valve body that is provided in the valve body, integrally displaces under the displacement action of the movable iron core, and switches a communication state between the one port and the other port;
With
The fixed iron core includes a through hole through which a shaft fixed along the axial direction with respect to the movable iron core is inserted, and a concave portion facing the valve body, and the concave portion has a diameter larger than that of the through hole. It is characterized by being formed.

  According to the present invention, the fixed iron core constituting the solenoid part is provided with a through hole and a recess, and the recess is opposed to the valve body and extends in a direction away from the through hole. Further, the concave portion is formed so as to have a larger diameter than the through hole. Therefore, by providing the concave portion with respect to the fixed iron core, the valve body side of the fixed iron core can be suitably thinned, and accordingly, the weight of the fixed iron core can be reduced. Therefore, the weight of the linear solenoid valve including the fixed iron core can be reduced.

  Moreover, since the length of the through-hole which can support a shaft becomes short with the recessed part provided in the fixed iron core, the processing amount given with respect to this through-hole is reduced. Therefore, the manufacturing cost of the linear solenoid valve can be reduced by reducing the processing cost of the fixed iron core.

  Furthermore, since the concave portion is provided on the valve body side of the fixed core that is opposite to the movable core, a through hole provided between the concave portion and the movable core is disposed closer to the movable core. Can do. Therefore, it is possible to improve the positional accuracy of the through hole and the annular flange as compared with the prior art in which the shaft support position and the annular flange are separated in the long through hole. As a result, the relative positional accuracy between the annular flange and the movable iron core can be improved, and the movable iron core can be displaced smoothly and with high accuracy. Accordingly, it is possible to improve the hysteresis characteristic of the movable iron core that is displaced together with the shaft.

  Furthermore, by providing the through hole with a bearing that supports the shaft so as to be displaceable along the axial direction, the shaft can be reliably and accurately supported when the shaft is displaced. It becomes possible to further improve the hysteresis characteristics of the iron core.

  Furthermore, by forming the fixed iron core by forging or pressing, it is possible to easily provide the concave portion with respect to the fixed iron core.

  According to the present invention, the following effects can be obtained.

  That is, it is possible to reduce the manufacturing cost by reducing the weight of the fixed core by providing the concave portion in the fixed core constituting the solenoid portion and reducing the processing applied to the through hole.

  Further, since the through hole can be provided at a position closer to the movable iron core side, and the through hole can be arranged close to the annular flange, the hysteresis characteristic when the movable iron core is displaced accordingly is provided. Can be improved.

  Preferred embodiments of the linear solenoid valve according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a hydraulic control valve used as a linear solenoid valve according to an embodiment of the present invention.

  As shown in FIGS. 1 to 3, the hydraulic control valve 10 is formed in a bottomed cylindrical shape by a magnetic material, and has a housing 14 provided with a solenoid portion 12 therein, and is connected to the housing 14. The mechanism part 16 includes a valve body 18 provided therein. The housing 14 and the valve body 18 function as a valve main body.

  The housing 14 includes a cylindrical portion 20, a yoke 22 that is formed substantially parallel to the inner circumferential side of the cylindrical portion 20, a bottom portion 24 that connects the cylindrical portion 20 and the yoke 22, and the bottom portion 24, and a protrusion 26 protruding by a predetermined length in the axial direction of the housing 14. A hole 30 is formed inside the protrusion 26 so that one end of a shaft 28 to be described later faces.

  The solenoid unit 12 is disposed so as to be surrounded by the housing 14, and has a bobbin 34 around which a coil 32 is wound on an outer peripheral surface, and a movable part provided inside the bobbin 34 so as to be displaceable along the axial direction. A core (movable iron core) 36, a fixed core (fixed iron core) 38 disposed on the valve body 18 side (in the direction of arrow A) facing the movable core 36, and the center of the movable core 36 are fitted. And a shaft 28.

  The bobbin 34 is provided such that a part of its inner peripheral surface abuts on the yoke 22 of the housing 14, and flanges 42 a and 42 b that are radially expanded at one end and the other end along the axial direction. Are formed respectively. The coil 32 is wound between the pair of flanges 42a and 42b.

  Between the housing 14 and the coil 32, a resin sealing body 44 that integrally molds the outer peripheral surface of the coil 32 and a part of the bobbin 34 is provided, and the coil 32 and the bobbin 34 are formed by the resin sealing body 44. Is covered from the outer peripheral side. The one end and the other end of the resin sealing body 44 are engaged with the flanges 42a and 42b of the bobbin 34, respectively, so that the coil 32 is surrounded by the bobbin 34 and the resin sealing body 44. Yes.

  Further, the resin sealing body 44 is integrally formed with a coupler portion 46 for energizing the coil 32, and the terminal portion 50 of the terminal 48 connected to the coil 32 through the bobbin 34 is exposed to the coupler portion 46. .

  The movable core 36 has a shaft hole 52 penetrating along the axial direction at a substantially central portion thereof, and the shaft 28 is fitted and fixed to the shaft hole 52. One end of the shaft 28 is supported by a first bearing 54 mounted in the hole 30 of the protrusion 26 in the housing 14, and the other end of the shaft 28 is in a through-hole 56 of the fixed core 38 described later. It is supported by the mounted second bearing 58. That is, the shaft 28 is pivotally supported by the first and second bearings 54 and 58 so as to be slidable along the axial direction (directions of arrows A and B).

  The first bearing 54 is press-fitted and fixed in the hole 30 of the projection 26 in the housing 14, and a first communication groove 60 is formed on the outer peripheral surface of the first bearing 54 along the axial direction. One end surface side and the other end surface side of the first bearing 54 communicate with each other through the first communication groove 60.

  In addition, a disc-shaped plate body 62 is provided on the end surface of the movable core 36 so as to face the fixed core 38. By forming the plate body 62 from a nonmagnetic material, residual magnetism in the solenoid portion 12 is prevented. It can be made to function as a spacer. That is, residual magnetism is generated in the fixed core 38 or the movable core 36 when the energization of the solenoid unit 12 is interrupted, and the movable core 36 may not be separated from the fixed core 38 under the action of the residual magnetism. By providing the plate body 62 via the shaft 28 on the end face, a predetermined clearance is formed between the fixed core 38 and the occurrence of residual magnetism can be suppressed.

  The fixed core 38 is formed of a magnetic material, and is provided at a main body portion 64 that abuts on the inner peripheral surface of the bobbin 34 and at the other end portion of the main body portion 64. And an annular flange 65 provided at one end of the main body portion 64 and having a conical surface portion 65a on the outer peripheral side.

  The main body portion 64 is formed with a first recess 68 that is recessed by a predetermined depth in a direction away from the movable core 36 (in the direction of arrow A) on one end surface facing the movable core 36. The first recess 68 is formed coaxially with the movable core 36 and slightly larger in diameter than the movable core 36, and a part of the first recess 68 is inserted into the first recess 68 under the displacement action of the movable core 36. The

  On the other hand, a second recess (recess) 70 is formed on the other end surface of the main body 64 on the valve body 18 side, which is recessed by a predetermined depth in a direction away from the valve body 18 (arrow B direction). The second recess 70 is formed coaxially with the first recess 68 and smaller in diameter than the first recess 68, and opens toward the valve body (in the direction of arrow A). Here, the 2nd recessed part 70 is simply formed by manufacturing the fixed core 38 by forge molding or press work, for example. Thereby, the second recess 70 can be easily provided on the main body 64.

  A through hole 56 that communicates the first recess 68 and the second recess 70 is formed along the axial direction at a substantially central portion of the main body 64, and the through hole 56 is interposed via a second bearing 58. The shaft 28 is inserted and slidably supported.

  The second bearing 58 is press-fitted into the through hole 56 and fixed, and a second communication groove 74 is formed on the outer peripheral surface of the second bearing 58 along the axial direction. The communication state between the first recess 68 and the second recess 70 is maintained through the second communication groove 74. In this case, both end portions of the shaft 28 are supported via the first and second bearings 54 and 58, respectively, so that the movable core 36 into which the shaft 28 is fitted can have a both-end support structure. Thereby, the movable core 36 can be stably linearly displaced.

  In other words, the main body 64 has a cylindrical shape in which one end and the other end of the main body 64 on the movable core 36 and the valve body 18 side are separated from the shaft 28 inserted through the through hole 56 in the radial direction. The shaft 28 is supported through the through hole 56 at a substantially central portion of the main body 64 along the axial direction. As described above, in the fixed core 38, the central portion is thinned by providing the second recess 70, so that the weight of the fixed core 38 itself is reduced. Note that the first and second recesses 68 and 70 are formed to expand in the radially outward direction from the through hole 56.

  On the other hand, the enlarged diameter portion 66 abuts on a flange portion 18a formed at the end portion of the valve body 18 and is integrally crimped by the end portion of the housing 14 together with the flange portion 18a.

  The valve mechanism 16 includes an inlet port (port) 76 through which pressure oil flows, an outlet port (port) 78, a drain port 80, and a valve body 18 having a breather port 82 communicating with an oil tank (not shown), and the valve A spool valve 84 is provided inside the body 18 so as to be displaceable along the axial direction.

  The valve body 18 abuts on the diameter-expanded portion 66 of the fixed core 38 via the flange portion 18 a, and is swaged and connected together with the fixed core 38 by the end portion of the housing 14. Further, a space portion 86 penetrating along the axial direction is defined inside the valve body 18, and an end portion of the space portion 86 is closed by an end block 88. A return spring 90 is interposed between the end block 88 and the spool valve 84, and the spool valve 84 is attached toward the solenoid portion 12 (in the direction of arrow B) under the elastic action of the return spring 90. Be forced. The return spring 90 is not limited to a coil spring, and may be constituted by an elastic body including a leaf spring (not shown), for example.

  The spool valve 84 is provided in the space portion 86 of the valve body 18, and is formed in order from the solenoid portion 12 side to the end block 88 side (arrow A direction), and the first land portion 84a, the second land portion 84b, and the second land portion 84b. 3 land portions 84c are included. The first and second land portions 84a and 84b are formed with substantially the same diameter, and the third land portion 84c is formed with a slightly smaller diameter than the first and second land portions 84a and 84b. .

  The end face 85 of the spool valve 84 adjacent to the solenoid portion 12 is provided so as to contact the other end portion 28b of the shaft 28, and the elastic force of the return spring 90 is movable via the spool valve 84 and the shaft 28. It is given to the core 36. In other words, the movable core 36 is in a state of being pressed toward the direction away from the valve body 18 (arrow B direction).

  The hydraulic control valve 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described. 1 is not energized (off state), the spool valve 84 is pressed in the direction of arrow B in FIG. 1 by the elastic force of the return spring 90. The communication between the inlet port 76 and the outlet port 78 is blocked.

  From this state, by energizing a power source (not shown) and energizing the coil 32, the solenoid unit 12 is excited and turned on, and electromagnetic force is generated. In this case, an electromagnetic force proportional to the amount of current supplied to the coil 32 is generated, and the electromagnetic force is applied to the movable core 36. Therefore, when the spool valve 84 is displaced in the direction of arrow A against the elastic force of the return spring 90 under the action of the electromagnetic force, the communication between the drain port 80 and the outlet port 78 is blocked. The inlet port 76 and the outlet port 78 communicate with each other (see FIG. 3).

  Therefore, the pressure oil supplied from a hydraulic source (not shown) is supplied to a hydraulic operating device (not shown) through the inlet port 76 and the outlet port 78 through a passage (not shown). When the energization to the solenoid unit 12 is stopped, the solenoid unit 12 is turned off and returned to the initial position shown in FIG.

  As described above, in the present embodiment, the second concave portion 70 that is hollow with respect to the main body portion 64 is provided at the other end portion of the fixed core 38 that is on the valve body 18 side. (A direction). In other words, the central portion of the fixed core 38 is thinned to form the second recess 70. Therefore, it is possible to reduce the weight of the fixed core 38 made of a metal material, and accordingly, it is possible to reduce the weight of the hydraulic control valve 10.

  In this case, the fixed core 38 is thinned in the radial direction by the second concave portion 70 provided in the main body portion 64, and therefore, the fixed core 38 is long without providing the second concave portion 70 with respect to the fixed core 38 shown in FIG. Compared to the case of a solenoid valve according to the prior art having only a through hole 56a (in the form of a two-dot chain line in FIG. 2), the cross-sectional area of the magnetic path that generates an electromagnetic force under the excitation action of the coil 32 is reduced. It becomes. However, based on the thrust (electromagnetic force) required when attracting the movable core 36, the minimum necessary magnetic path cross-sectional area in the fixed core 38 is calculated in advance, and the second based on the magnetic path cross-sectional area is calculated. The fixed core 38 including the main body 64 is formed by setting the inner peripheral diameter of the recess 70. Thereby, a desired thrust can be obtained under the exciting action of the solenoid unit 12 without reducing the thrust (electromagnetic force) generated through the fixed core 38.

  Here, the relationship between the thrust generated in the solenoid unit 12 and the amount of displacement of the movable core 36 will be briefly described with reference to FIG. FIG. 4 is a characteristic curve diagram showing the relationship between the thrust generated in the solenoid unit 12 and the amount of displacement along the axial direction of the movable core 36, and the characteristic curve C shown by the solid line is shown in the present embodiment. The characteristic regarding the hydraulic control valve 10 is shown, and the characteristic curve D shown by the broken line is the characteristic related to the electromagnetic valve according to the related art having only the long through hole 56a without providing the second recess in the fixed core shown in FIG. Is shown.

  In the hydraulic control valve 10 according to the present embodiment, the magnetic path cross-sectional area is reduced by providing the second recess 70 in the fixed core 38. However, as indicated by the solid line, the displacement of the movable core 36 is reduced. It can be understood that the accompanying thrust has a numerical value substantially equivalent to the thrust (two-dot chain line) of the solenoid valve according to the prior art.

  Thus, by forming the fixed core 38 with a magnetic path cross-sectional area capable of generating the thrust required to attract the movable core 36, the thrust (attraction force) generated via the fixed core 38 is reduced. Without this, it is possible to obtain a desired thrust under the excitation action of the solenoid unit 12.

  Further, since the through hole 56 of the fixed core 38 is provided between the first recess 68 and the second recess 70, the through hole 56 is disposed in the vicinity of the annular flange 65. Therefore, the other end portion 28 b of the shaft 28 can be supported at a position closer to the movable core 36 via the second bearing 58. As a result, compared with the prior art in which the bearing position (shaft support position) arranged at the end on the spool valve side in the long through hole 56a and the annular flange are separated from each other, the first is provided in the through hole 56. The positional accuracy between the two bearings 58 and the annular flange 65 can be improved.

  As a result, the relative positional accuracy between the movable core 36 and the annular flange 65 can be improved, and the movable core 36 can be displaced smoothly and with high accuracy. Thereby, the hysteresis characteristic when the movable core 36 is displaced can be improved.

  Furthermore, by providing the second recess 70 in the fixed core 38, the length dimension along the axial direction of the through hole 56 that supports the shaft 28 via the second bearing 58 is shortened. The amount of processing applied to the processing can be reduced. That is, the fixed core is compared with the electromagnetic valve according to the prior art in which only the long through hole 56a is provided in the central portion of the fixed core 38 without providing the second recess, and the through hole 56a is processed. The amount of processing for 38 can be reduced. As a result, the processing cost for the fixed core 38 is reduced, and accordingly, the manufacturing cost of the hydraulic control valve 10 can be reduced.

1 is an overall longitudinal sectional view of a hydraulic control valve according to an embodiment of the present invention. It is an expanded sectional view which shows the fixed core vicinity in the hydraulic control valve of FIG. FIG. 2 is an overall longitudinal sectional view showing a state in which a spool valve is displaced against an elastic force of a return spring under the excitation action of a solenoid portion in the hydraulic control valve of FIG. 1. 2 is a characteristic curve showing a relationship between a stroke amount of a movable core and thrust in the hydraulic control valve of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Hydraulic control valve 12 ... Solenoid part 14 ... Housing 16 ... Valve mechanism part 18 ... Valve body 22 ... Yoke 28 ... Shaft 32 ... Coil 34 ... Bobbin 36 ... Movable core 38 ... Fixed core 44 ... Resin sealing body 46 ... Coupler Portion 54... First bearing 58. Second bearing 64. Main body 65. Ring flange 68. First recess 70. Second recess 84. Spool valve 86 ... Space 88. End block 90.

Claims (3)

In the linear solenoid valve that switches the communication state between one port through which the pressure fluid flows and the other port by attracting the movable iron core under the excitation action of the solenoid part,
A valve body including a valve body and a housing having one and other ports through which pressure fluid flows; and
A coil provided on the housing, wound around a bobbin, a movable iron core provided to be displaceable along the axial direction, and provided between the movable iron core and the valve body, and disposed opposite to the movable iron core. And a solenoid part having a fixed iron core that attracts the movable iron core under energizing action on the coil, and a yoke that surrounds an outer peripheral surface of the movable iron core,
A valve mechanism having a valve body that is provided in the valve body, integrally displaces under the displacement action of the movable iron core, and switches a communication state between the one port and the other port;
With
The fixed iron core includes a through hole through which a shaft fixed along the axial direction with respect to the movable iron core is inserted, and a concave portion facing the valve body, and the concave portion has a diameter larger than that of the through hole. A linear solenoid valve characterized by being formed as follows. The linear solenoid valve according to claim 1,
The linear solenoid valve according to claim 1, wherein the through hole is provided with a bearing that supports the shaft so as to be displaceable along an axial direction. The linear solenoid valve according to claim 1 or 2,
The linear iron valve, wherein the fixed iron core is formed by forging or pressing.

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