JP2011009381A - Linear solenoid and valve device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a linear solenoid compact in size while enhancing a hysteresis characteristics.SOLUTION: The linear solenoid comprises a linear solenoid 12 comprising a cylindrical movable core 22 which is attracted toward a fixed core 20 when a coil 26 is energized, and a cylindrical yoke 14b which surrounds the outer circumferential surface of the movable core 22 where the movable core 22 has a shaft-less structure, a single plain bearing 36 for slidably supporting the movable core 22 is provided in the intermediate part of the cylindrical yoke 14b along the axial direction, and the inner diameter part of the plain bearing 36 is formed to project radially inward by a predetermined length (T) from the inner circumferential surface of the cylindrical yoke 14b toward the movable core 22.

Description

  The present invention relates to a linear solenoid that exhibits an exciting action when energized and a valve device using the linear solenoid.

  Conventionally, a linear solenoid valve having a valve body that displaces a movable core by an excitation action of a solenoid and switches between a communication state and a non-communication state of an inlet port and an outlet port by transmitting the displacement of the movable core has been used. ing.

  With regard to this type of linear solenoid valve, the present applicant has proposed a linear solenoid valve that can further improve the suction force with respect to the movable core (see, for example, Patent Document 1).

  In the linear solenoid valve disclosed in Patent Document 1, both ends of the shaft passing through the center of the movable core are respectively formed by a first flat bearing and a second flat bearing formed of a sintered body containing a sintered metal. It is configured to support.

JP 2006-97723 A

  By the way, in the linear solenoid valve disclosed in Patent Document 1, since the shaft is fixed along the central hole that penetrates the movable core, for example, the outer diameter of the movable core is reduced to reduce the diameter. Then, there is a possibility that a saturation state of magnetic flux density occurs in the movable core. As a result, it becomes difficult to reduce the diameter of the movable core, and it becomes difficult to ultimately reduce the size of the solenoid.

  Further, in the linear solenoid valve disclosed in Patent Document 1, when the shaft is press-fitted along the central hole through which the movable core passes, the coaxiality between the axis of the movable core and the axis of the shaft is shifted, so that the movable There is a concern that the force (side force) for attracting the movable core in the radial direction toward the cylindrical yoke side increases between the outer peripheral surface of the core and the inner peripheral surface of the cylindrical yoke surrounding the movable core. Is done. As a result, it becomes difficult to improve the hysteresis characteristics of the solenoid.

  Furthermore, since both ends of the shaft that penetrates the movable core are supported by the first flat bearing and the second flat bearing, respectively, the solenoid is elongated along the axial direction of the shaft. As a result, it is difficult to reduce the size of the solenoid.

  The present invention has been made in view of the above points, and an object thereof is to provide a linear solenoid capable of reducing the size and improving the hysteresis characteristics, and a valve device using the linear solenoid. .

  In order to achieve the above object, the present invention is provided in a housing and surrounds a coil, a columnar movable core that is attracted to a fixed core under a current-carrying action on the coil, and an outer peripheral surface of the movable core. A linear solenoid part having a cylindrical yoke, wherein the movable core is shaftless, and the movable core is provided at an intermediate part between one end part and the other end part in the axial direction of the cylindrical yoke. A single bearing that is slidably supported is provided, and the bearing is provided so as to protrude from the inner peripheral surface of the cylindrical yoke in a radially inward direction toward the movable core side by a predetermined length.

  According to the present invention, by adopting a shaftless structure in which the conventional shaft is not provided for the movable core, the magnetic flux density saturation of the movable core can be reduced as compared with the conventional structure in which the shaft is provided. . As a result, in the present invention, it is possible to reduce the diameter of the movable core and / or reduce the axial dimension, thereby reducing the size of the movable core. As a result, the entire linear solenoid can be reduced in size.

  Further, according to the present invention, since the single bearing is disposed at the intermediate portion between the one end portion and the other end portion along the axial direction of the cylindrical yoke, the coaxiality of the movable core with respect to the cylindrical yoke is improved. Can be easily achieved. By ensuring the coaxiality of the movable core with respect to the cylindrical yoke, it is possible to reduce the side force (the force for attracting the movable core in the radially outward direction) and obtain good hysteresis characteristics.

  Furthermore, according to the present invention, for example, by appropriately setting the protrusion amount (predetermined length) of the bearing that protrudes radially inward from the inner peripheral surface of the cylindrical yoke toward the movable core side, the inner periphery of the cylindrical yoke is set. A magnetic gap, which is a gap in the radial direction between the surface and the outer peripheral surface of the movable core, can be easily set with high accuracy. As a result, in the present invention, the magnetic gap can be set to a minimum and the attractive force with respect to the movable core can be improved.

  Furthermore, according to the present invention, the single bearing is disposed at the intermediate portion along the axial direction of the cylindrical yoke, thereby preventing the flow of magnetic flux from the bottom of the housing toward the movable core by the single bearing. This is preferably avoided, and the magnetic flux flowing in from the bottom side of the housing toward the movable core can be improved. Therefore, in the present invention, the magnetic flux density generated by the exciting action of the linear solenoid can be increased, and the attractive force with respect to the movable core can be improved. As a result, in the present invention, it is possible to achieve both the miniaturization of the linear solenoid in which the axial dimension of the movable core is shortened and the attraction force of the movable core by increasing the generated magnetic flux density. In addition, by making the bearing which supports a movable core slidable into a single member, the number of parts can be reduced and it can contribute to cost reduction.

  Further, according to the present invention, on the fixed core side of the inner peripheral surface of the cylindrical yoke, a single annular recess is provided in which the bearing can be inserted from the fixed core side along the axial direction of the cylindrical yoke. It is characterized by being able to.

  According to the present invention, a single bearing that slidably supports the movable core is inserted (including press-fit) from the fixed core side along the axial direction of the cylindrical yoke. The bearing can be easily attached to a single annular recess formed on the surface, and the assembling work is facilitated and the assembling property can be improved.

  Further, according to the present invention, the annular concave portion into which the bearing can be inserted only from the direction of the fixed core side is provided on the inner peripheral surface of the cylindrical yoke, and the housing bottom side formed in the direction opposite to the fixed core side is provided. By adopting a structure in which no annular recess is provided on the inner peripheral surface of the cylindrical yoke, the cylindrical yoke and the housing bottom can be integrated. In this case, for example, as compared with a structure in which a cap member or the like is provided on the housing bottom side to close the housing bottom, the number of assembling steps and the number of parts can be reduced and the manufacturing cost can be reduced.

  Furthermore, according to the present invention, since it is only necessary to form a single annular recess on the inner peripheral surface of the cylindrical yoke, for example, when a plurality of annular recesses are provided on the inner peripheral surface of the cylindrical yoke, In comparison, it is possible to avoid the occurrence of a shift in the coaxiality between the cylindrical yoke and the movable core. As a result, the coaxial property between the cylindrical yoke and the movable core can be achieved, and the hysteresis characteristics can be improved.

  Further, according to the present invention, the housing includes a housing bottom provided on one end side along the axial direction of the housing, a cylindrical projecting portion extending from the housing bottom, and a projecting extending from the cylindrical projecting portion. A first stopper member made of a non-magnetic material and restricting one displacement of the movable core is provided on the protruding bottom portion, and the first stopper member penetrates the through hole of the protruding bottom portion. The columnar portion is swaged and plastically deformed on the inner wall of the protruding bottom portion, thereby being fixed to the protruding bottom portion.

  According to the present invention, it is possible to regulate the displacement of one of the movable cores through the first stopper member made of a nonmagnetic material fixed to the projecting bottom portion by forming the projecting bottom portion. In addition, the first stopper member made of a non-magnetic material is configured with a simple structure consisting of one part, and the columnar portion penetrating the through hole of the protruding bottom portion is swaged to be plastically deformed on the inner wall side of the protruding bottom portion. Manufacturing costs can be reduced by manufacturing.

  Furthermore, according to the present invention, the fixed core is formed with a recess facing the movable core, and a second stopper member for restricting the other displacement of the movable core is press-fitted into a hole continuous with the recess. The second stopper member is provided with an insertion hole through which a displacement transmitting member for transmitting the displacement of the movable core is inserted.

  According to the present invention, the other displacement of the movable core can be regulated via the second stopper member press-fitted into the hole continuous with the concave portion of the fixed core. In addition, the displacement transmitting member can be moved by transmitting the displacement of the movable core through the insertion hole formed in the second stopper member. Furthermore, the second stopper member can be simply and reliably fixed to the fixed core by press-fitting the second stopper member into the hole of the fixed core.

  Still further, the present invention provides a valve body having a plurality of ports through which pressure fluid flows, the linear solenoid according to any one of claims 1 to 4, and the valve body, wherein the movable core displaces the valve body by displacement of the movable core. And a valve mechanism having a valve body that switches between a communication state and a non-communication state between a plurality of ports.

  By configuring the valve device in this way, it is possible to provide a valve device having a linear solenoid that is downsized and has improved hysteresis characteristics, and can achieve a reduction in size and weight of the entire valve device. .

According to the present invention, it is possible to obtain a linear solenoid capable of reducing the size of the linear solenoid and improving the hysteresis characteristics.
Further, according to the present invention, it is possible to obtain a valve device including a linear solenoid that is downsized and has improved hysteresis characteristics.

It is a longitudinal cross-sectional view along the axial direction of the hydraulic control apparatus with which the linear solenoid which concerns on embodiment of this invention was integrated. FIG. 2 is an enlarged longitudinal sectional view of a linear solenoid part of the hydraulic control device shown in FIG. 1. (A) is an enlarged vertical sectional perspective view showing a state in which the movable core is in contact with the first stopper member, and (b) is an enlarged vertical sectional perspective view showing a state in which the second stopper member is press-fitted into the fixed core. FIG. (A)-(c) is explanatory drawing which shows the process by which the 1st stopper member is rolling caulking with respect to the protrusion bottom part of a housing. (A)-(c) is explanatory drawing which shows the process in which a flat bearing is assembled | attached with respect to a cylindrical yoke. FIG. 2 is a longitudinal sectional view showing a state in which the linear solenoid part is energized and the valve position of the spool is switched from the OFF state of the linear solenoid part shown in FIG. 1. (A) is explanatory drawing which shows the magnetic flux flow which generate | occur | produced in the linear solenoid part in the initial state which the movable core contacted the 1st stopper member, (b) is in the displacement terminal position which the movable core displaced to the fixed core side. It is explanatory drawing which shows the magnetic flux flow which generate | occur | produced in the linear solenoid part.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. 1 is a longitudinal sectional view along the axial direction of a hydraulic control apparatus incorporating a linear solenoid according to an embodiment of the present invention, and FIG. 2 is an enlarged longitudinal sectional view of a linear solenoid portion of the hydraulic control apparatus shown in FIG. It is.

  As shown in FIG. 1, a hydraulic control device (valve device) 10 includes, for example, a housing 14 that is formed of a magnetic metal material into a bottomed cylindrical shape, and in which a linear solenoid portion (linear solenoid) 12 is disposed. And a sleeve-like valve body 18 integrally connected to the housing 14 and provided with a valve mechanism 16 therein.

  As shown in FIGS. 1 and 2, the housing 14 has a cylindrical portion 14a that is elongated along the axial direction and is provided on the outermost diameter side, and a predetermined interval radially inward of the cylindrical portion 14a. The cylindrical yoke 14b is formed so as to be spaced apart, extends substantially parallel to the cylindrical portion 14a, and is formed in a short length. The cylindrical yoke 14b and the cylindrical yoke 14b are formed at one end portion (joining site) in the axial direction. It includes a housing bottom portion 14c having an axial thickness that is thicker than the radial thickness of the cylindrical portion 14a.

  Further, the housing 14 includes a cylindrical protrusion 14d that is continuous with the housing bottom 14c and extends substantially parallel to the cylindrical part 14a, and a first stopper member 19 that extends from the cylindrical protrusion 14d and is described later. And a projecting bottom part 14e fixed to the part. In this case, the cylindrical portion 14a, the cylindrical yoke 14b, the housing bottom portion 14c, the cylindrical protruding portion 14d, and the protruding bottom portion 14e are integrally formed.

  As shown in FIG. 2 and FIG. 3A, the first stopper member 19 is formed of a substantially H-shaped member made of a nonmagnetic material and has one end in the axial direction of the movable core 22 to be described later. It functions as a stopper that contacts and regulates one displacement of the movable core 22. The first stopper member 19 is held in the through hole 21 of the projecting bottom portion 14e (may be loosely fitted through a clearance), and one circle engaged with the inner wall side of the projecting bottom portion 14e. The plate portion 19b and the other disc portion 19c engaged with the outer wall side of the protruding bottom portion 14e are integrally configured. An annular gap portion 23 is formed between the movable core 22 to be described later and the inner wall of the projecting bottom portion 14e that faces the movable core 22 to be described later. Is done.

  In this case, as shown in FIGS. 4A to 4C, the columnar portion 19d of the first stopper member 19 before processing is inserted along the through hole 21 formed in the protruding bottom portion 14e of the housing 14, By pressurizing and plastically deforming the columnar portion 19d with the rotation shaft M of the rolling caulking device, the columnar portion 19d of the first stopper member 19 expands along the inner wall of the projecting bottom portion 14e, thereby forming the disc portion 19b. As a result, the first stopper member 19 is fixed to the substantially central portion of the protruding bottom portion 14e.

  In the present embodiment, a protruding bottom portion 14e is formed in the housing 14, and the displacement of one of the movable cores 22 can be restricted via the first stopper member 19 made of a nonmagnetic material fixed to the protruding bottom portion 14e. Further, the first stopper member 19 made of a non-magnetic material is configured with a simple structure consisting of one part, and the columnar portion 19d penetrating the through hole 21 of the protruding bottom portion 14e is plastically deformed by rolling caulking to simplify the operation. Manufacturing costs can be reduced by manufacturing.

  The cylindrical yoke 14b is, for example, a press-fit fitting (not shown) in which another yoke (not shown) made of a substantially cylindrical body formed separately from the housing 14 is formed on the inner peripheral surface of the housing bottom portion 14c. You may form so that it may press-fit to a part.

  As shown in FIGS. 1 and 2, the linear solenoid part 12 includes a coil assembly housed in a housing 14, and is integrally formed with the housing 14 on the closed end side of the housing 14. A cylindrical yoke 14b disposed in the interior of the solid body is coupled to the opening end of the cylindrical portion 14a, and is disposed along the axial direction inside the coil assembly with a predetermined clearance from the cylindrical yoke 14b. The fixed core 20, the movable core 22 that is displaceably disposed inside the cylindrical yoke 14b, and the hole 20b that is continuous with the concave portion 20a of the fixed core 20 that the movable core 22 faces. And a second stopper member 25 for restricting the other displacement of the movable core 22.

  As shown in FIGS. 2 and 3 (b), one end portion of the fixed core 20 facing the movable core 22 at a predetermined interval has a tapered surface whose outer peripheral surface is gradually reduced in diameter, An annular flange 20c having a vertical cross section formed into an acute angle is provided. The second stopper member 25 is made of a non-magnetic material, and has an annular flange portion 25a that engages with the concave portion 20a of the fixed core 20, and a press fit into the hole portion 20b of the fixed core 20 that is continuous with the flange portion 25a. And a cylindrical portion 25b. The cylindrical portion 25b is provided with an insertion hole 25c through which a shaft portion 40b of a spool (displacement transmission member) 40 described later is inserted. Further, the coil assembly includes a coil bobbin 24 formed of a resin material and having flanges at both ends along the axial direction, and a coil 26 wound around the coil bobbin 24.

  Between the housing 14 and the coil 26, a resin sealing body 28 in which the outer peripheral surface of the coil 26 is molded is provided. The resin sealing body 28 is a coupler (not shown) connected to the coil 26. It is integrally formed of a resin material including the part. The coupler portion is provided with a terminal terminal portion (not shown) that is electrically connected to the coil 26.

  The movable core 22 is formed of a shaftless cylindrical body that is not provided with a conventional shaft penetrating the central portion thereof, and the cylindrical body has a separation angle of about 180 degrees along the circumferential direction and in the axial direction. A plurality of flow path holes 30a and 30b penetrating along are provided. The flow holes 30a and 30b allow the pressure oil on one end side and the pressure oil on the other end side along the axial direction of the movable core 22 to flow.

  A single portion that is mounted (press-fitted) in an annular recess 32 formed on the inner peripheral surface of the cylindrical yoke 14b at an intermediate portion between one end portion and the other end portion along the axial direction of the movable core 22. The flat bearing 36 is provided, and the movable core 22 is supported via the flat bearing 36 so as to be slidable along the axial direction. The movable core 22 may be integrally formed including a shaft portion 40b of the spool 40 described later.

  In the longitudinal cross section shown in FIGS. 2 and 3A, the flat bearing 36 is constituted by an annular body having a constant inner diameter along the axial direction. The annular body includes, for example, an outer diameter layer (back metal layer) formed of a metal material such as SPCC (JIS standard), and a bronze sintered layer (intermediate layer) formed by sintering bronze or the like. It is preferable to use a bearing that is formed by laminating a resin layer (inner diameter layer) made of a resin material such as tetrafluoroethylene resin, which is a sliding surface with the movable core 22. As this bearing, for example, a sliding bearing having self-lubricating property is used, and wear resistance can be improved by using such a sliding bearing having self-lubricating property.

  An inner diameter surface of the flat bearing 36 slidably contacting the outer peripheral surface of the movable core 22 is provided so as to protrude by a predetermined length T from the inner peripheral surface of the cylindrical yoke 14b in the radial direction (see FIG. 2). Accordingly, the movable core 22 is in sliding contact with only the flat bearing 36, and a radial direction corresponding to the protruding amount (predetermined length T) is provided between the inner peripheral surface of the cylindrical yoke 14b and the outer peripheral surface of the movable core 22. A gap 37 is formed. The radial gap 37 functions as a magnetic gap in the radial direction between the movable core 22 and the cylindrical yoke 14b.

  It should be noted that as a guide surface when the flat bearing 36 is assembled to the cylindrical yoke 14b at one end portion of the annular recess 32 of the cylindrical yoke 14b into which the flat bearing 36 is press-fitted and close to the fixed core 20. A functioning tapered surface 39 is formed.

  Thus, a support structure can be provided in which the intermediate portion of the movable core 22 is slidably supported via the flat bearing 36 disposed on the inner peripheral surface of the cylindrical yoke 14b. As a result, stable linearity of the movable core 22 and coaxiality between the cylindrical yoke 14b and the movable core 22 can be easily secured, and the hysteresis characteristics of the linear solenoid portion 12 can be improved. This will be described in detail later.

  In this embodiment, the flat bearing 36 formed separately from the cylindrical yoke 14b is arranged on the side close to the fixed core 20 of the cylindrical yoke 14b. For example, the cylindrical yoke 14b An annular protrusion (not shown) that protrudes by a predetermined length T from the inner peripheral surface toward the movable core 22 may be formed integrally with the cylindrical yoke 14b. In contrast to the above, an annular convex portion (not shown) that protrudes by a predetermined length T toward the cylindrical yoke 14 b side may be integrally formed on the outer peripheral surface of the movable core 22.

  The second stopper member 25 provided in the recessed portion 20a of the fixed core 20 is formed of a nonmagnetic material, and when the energization to the coil 26 is stopped, the movable core 22 remains attracted to the fixed core 20 due to the influence of residual magnetism. It has the function (preventing sticking prevention function) which prevents becoming.

  In this case, an exciting action is generated by turning on a power source (not shown) and causing a current to flow through the coil 26, and the movable core 22 is integrally displaced toward the fixed core 20 by the exciting action, so that a spool described later. 40 can be operated (advanced / retracted).

  Returning to FIG. 1, the valve mechanism 16 abuts the valve body 18 provided with an inlet port 44, an outlet port 46, and drain ports 48 and 50, and the end surface of the movable core 22 of the linear solenoid unit 12, thereby moving the movable body 22. It includes a spool (valve element) 40 slidably disposed along the space inside the valve body 18 by being pressed by the core 22.

  In addition, the drain port 50 introduces / leads out the pressure oil in the housing 14 corresponding to the advance / retreat operation of the movable core 22. The inlet port 44, outlet port 46, and drain port 48 function as a plurality of ports through which pressure fluid flows.

  The spool 40 has a valve main body, and the valve main body is inserted into a land portion 40a having a plurality of lands bulging outward in a radial direction and a through hole of the fixed core 20 so as to be freely advanced and retracted. The shaft portion 40b is in contact with the end surface of the movable core 22 at one end portion.

  In addition, an annular recess 52 that allows the inlet port 44 and the outlet port 46 to communicate with each other or the outlet port 46 and the drain port 48 to communicate with each other on the outer peripheral surface of the spool 40 in accordance with the displacement position of the spool 40. Is formed.

  Further, as shown in FIG. 1, the valve mechanism portion 16 is disposed so as to face the end surface of the spool 40, and includes a closing member 54 that closes the space portion of the valve body 18, and the spool 40 and the closing member 54. And a return spring 56 that is interposed therebetween and returns the spool 40 to the original position. A sealing ring 58 is provided on the outer peripheral surface of the closing member 54 to hold the mounting portion liquid-tight or air-tight through an annular groove.

  For example, the inlet port 44 is connected to an unillustrated hydraulic source (pressure fluid supply source) such as a hydraulic pump via a supply oil passage, and the outlet port 46 is connected to an unillustrated hydraulic device via an output oil passage. The drain port 48 is connected to a reservoir tank (not shown). In the present embodiment, the pressure oil is used for explanation. However, the present invention is not limited to this, and for example, a pressure fluid including compressed air or the like can be used as the working medium.

  The hydraulic control apparatus 10 according to the present embodiment is basically configured as described above. Next, the operation and effects thereof will be described.

  First, the assembly work of the flat bearing 36 to the cylindrical yoke 14b of the housing 14 will be described with reference to FIG.

  A flat bearing 36 is arranged on one end side (fixed core 20 side) along the axial direction of the cylindrical yoke 14b (see FIG. 5A), and the flat bearing 36 is slid along the tapered surface 39 which is a guide surface. Then, the flat bearing 36 is pressed in the lateral direction in the figure against the inner diameter surface of the annular recess 32 formed slightly smaller than the maximum outer diameter of the flat bearing 36 (see FIG. 5B). ). After the flat bearing 36 is press-fitted, the movable core 22 is inserted into a space in the flat bearing 36 formed in a ring shape (see FIG. 5C).

  Thus, in the present embodiment, a single flat bearing 36 is formed on the inner diameter surface of the cylindrical yoke 14b by press-fitting along the axial direction from one end side (the fixed core 20 side) of the cylindrical yoke 14b. The flat bearing 36 can be simply attached to the annular recess 32 thus made, the assembling work becomes easy and the assembling property can be improved.

  Further, in the present embodiment, an annular recess 32 into which the flat bearing 36 can be inserted only from the direction of the fixed core 20 side with respect to the inner peripheral surface of the cylindrical yoke 14b is provided, and from the direction opposite to the fixed core 20 side. The cylindrical yoke 14b and the housing bottom 14c can be integrated by adopting a structure in which the annular recess 32 is not provided on the inner peripheral surface of the cylindrical yoke 14b on the housing bottom 14c side. In this case, for example, compared with a structure in which a cap member or the like (not shown) is provided on the housing bottom portion 14c side to close the housing bottom portion 14c, the number of assembling steps and the number of parts can be reduced and the manufacturing cost can be reduced. .

  Furthermore, in this embodiment, since it is only necessary to form a single annular recess 32 on the inner peripheral surface of the cylindrical yoke 14b, for example, a plurality of annular recesses are provided on the inner peripheral surface of the cylindrical yoke 14b. Compared to the case, it is possible to avoid the occurrence of a shift in the coaxial degree between the cylindrical yoke 14b and the movable core 22. As a result, the coaxial property between the cylindrical yoke 14b and the movable core 22 can be achieved, and the hysteresis characteristics can be improved.

  Furthermore, in the present embodiment, the first stopper member 19 made of a nonmagnetic material is configured with a simple structure consisting of one component, and the columnar portion 19d penetrating the through hole 21 of the protruding bottom portion 14e (see FIG. 4). Can be produced simply by caulking them with a rolling caulking device and plastically deforming them with the inner wall of the protruding bottom portion 14e.

  Furthermore, in the present embodiment, the other displacement of the movable core 22 (displacement toward the fixed core 20) via the second stopper member 25 press-fitted into the hole 20 b continuous with the recess 20 a of the fixed core 20. Can be regulated. Further, the displacement of the movable core 22 is transmitted to the shaft portion 40b through the insertion hole 25c formed in the second stopper member 25, and the spool 40 can be moved. Furthermore, the second stopper member 25 can be simply and reliably fixed to the fixed core 20 by press-fitting the second stopper member 25 into the hole 20 b of the fixed core 20.

Next, the operation of the hydraulic control device 10 will be described.
When the linear solenoid part 12 is not energized, as shown in FIG. 1, no electromagnetic force (electromagnetic thrust) of the linear solenoid part 12 is generated, so that the spool 40 is driven by the spring force of the return spring 56. It is in the state pressed toward the side.

  Therefore, in the OFF state of the linear solenoid portion 12, as shown in FIG. 1, the inlet port 44 and the outlet port 46 are in communication with each other by the annular recess 52 formed on the outer peripheral surface of the spool 40 (FIG. 1). ), The pressure oil introduced from the inlet port 44 is supplied to other members (not shown) via the annular recess 52 and the outlet port 46.

  Thus, in the OFF state of the linear solenoid part 12, the movable core 22 is in its original position without any displacement, and is in a normally open state in which the inlet port 44 and the outlet port 46 communicate with each other.

  Next, a current is supplied to the linear solenoid unit 12 by a power source (not shown), so that the linear solenoid unit 12 is turned on. In this ON state, as shown in FIG. 6, the movable core 22 is attracted toward the fixed core 20 side while sliding along the single flat bearing 36 by the electromagnetic force proportional to the current value flowing to the coil 26. Then, the movable core 22 stops at the displacement end position in contact with the second stopper member 25 provided on the fixed core 20.

  That is, the displacement of the movable core 22 due to the exciting action of the linear solenoid portion 12 is transmitted to the spool 40, and the spool 40 is displaced in the direction approaching the closing member 54 side against the spring force of the return spring 56.

  Therefore, as shown in FIG. 6, the communication state between the inlet port 44 and the outlet port 46 is blocked by the land of the spool 40, and the outlet port 46 and the drain are separated by the annular recess 52 formed on the outer peripheral surface of the spool 40. The valve position is switched so that the port 48 is in communication.

  As a result, the outlet port 46 is in communication with the drain port 48 via an annular recess 52 formed on the outer peripheral surface of the spool 40 (see the thick arrow in FIG. 6), and the pressure oil remaining in the outlet port 46 is It is preferably discharged from the drain port 48.

  In the present embodiment, by adopting a shaftless structure in which the conventional shaft is not provided with respect to the movable core 22, it is possible to reduce the magnetic flux density saturation of the movable core 22 compared to the conventional structure in which the shaft is provided. it can. As a result, in the present embodiment, the movable core 22 can be reduced in diameter and / or shortened in the axial direction, and the movable core 22 can be reduced in size. As a result, the entire linear solenoid portion 12 can be reduced in size.

  In the present embodiment, since the single flat bearing 36 is disposed at an intermediate portion between one end and the other end along the axial direction of the cylindrical yoke 14b, the movable core 22 with respect to the cylindrical yoke 14b. The coaxiality can be easily achieved. By ensuring the coaxiality of the movable core 22 with respect to the cylindrical yoke 14b, it is possible to reduce the side force (the force for attracting the movable core 22 in the radially outward direction) and obtain good hysteresis characteristics.

  Furthermore, in this embodiment, the magnetic gap which is the gap 37 in the radial direction between the cylindrical yoke 14b and the movable core 22 can be set easily and with high accuracy. For example, by appropriately setting the recess depth of the annular recess 32 into which the flat bearing 36 is press-fitted, or by appropriately setting the thickness dimension of the flat bearing 36, the inner diameter surface of the flat bearing 36 becomes the cylindrical yoke 14 b. The protrusion amount (predetermined length T) that protrudes in the radial direction from the inner peripheral surface can be easily set. As a result, in this embodiment, the magnetic gap can be set to a minimum and the attractive force with respect to the movable core 22 can be improved.

  Moreover, in the present embodiment, as described above, by ensuring the coaxiality of the movable core 22 with respect to the cylindrical yoke 14b, it is possible to increase the attractive force with respect to the movable core 22 and to improve the hysteresis characteristics. Furthermore, in the present embodiment, by adopting a structure in which the movable core 22 partially slides only with the flat bearing 36, the sliding resistance can be significantly reduced and the hysteresis characteristics can be further improved.

  Furthermore, in this embodiment, the single flat bearing 36 is an intermediate portion along the axial direction of the cylindrical yoke 14b, and is substantially orthogonal to the axis of the movable core 22 as shown in FIG. 14c is arranged in a non-crossing manner with the alternate long and short dash line D passing through the central portion (thickness central portion along the axial direction) of 14c, thereby allowing the inflow of magnetic flux from the housing bottom portion 14c to the movable core 22 to flow into the single flat surface. The hindrance by the bearing 36 is preferably avoided, and the magnetic flux flowing from the housing bottom 14c toward the movable core 22 can be improved.

  Furthermore, in the present embodiment, the single flat bearing 36 is an intermediate portion along the axial direction of the cylindrical yoke 14b, and as shown in FIG. By being arranged at a position displaced by a predetermined distance ΔX in the substantially horizontal direction on the side, it is preferably avoided that the single flat bearing 36 prevents the flow of magnetic flux from the housing bottom 14c toward the movable core 22; The magnetic flux flow flowing from the housing bottom portion 14c side toward the movable core 22 can be further improved.

  FIG. 7A is an explanatory view showing a magnetic flux flow generated in the linear solenoid portion in an initial state in which the movable core is in contact with the first stopper member, and FIG. 7B is a diagram showing the movable core displaced toward the fixed core. It is explanatory drawing which shows the magnetic flux flow which generate | occur | produced in the linear solenoid part in a displacement terminal position.

  Since the single flat bearing 36 is disposed at a portion (see FIG. 2) that is displaced by a predetermined distance ΔX in the substantially horizontal direction from the inner bottom surface E of the housing 14 to the fixed core 20 side, FIG. As shown in FIG. 7B, when the magnetic flux flows from the housing bottom portion 14c toward the movable core 22 side, the flat bearing 36 does not become an obstruction member for the magnetic flux flow B (see C portion in FIG. 7). A smooth magnetic flux flow B can be obtained.

  Therefore, in this embodiment, the magnetic flux density generated by the excitation action of the linear solenoid part 12 can be increased, and the attractive force with respect to the movable core 22 can be improved. As a result, in the present embodiment, it is possible to achieve both the miniaturization of the linear solenoid portion 12 in which the axial dimension of the movable core 22 is shortened and the improvement in the attractive force of the movable core 22 due to the increase in the generated magnetic flux density. In addition, by making the bearing which supports the movable core 22 slidable into a single member, the number of parts can be reduced and it can contribute to cost reduction.

10 Hydraulic control device 12 Linear solenoid part (linear solenoid)
DESCRIPTION OF SYMBOLS 14 Housing 14b Cylindrical yoke 14c Housing bottom part 14d Cylindrical protrusion part 14e Projection bottom part 16 Valve mechanism part 18 Valve body 19 1st stopper member 19d Columnar part 20 Fixed core 20a Recessed part 20b Hole part 21 Through-hole 22 Movable core 25 2nd stopper member 26 Coil 32 Annular recess 36 Flat bearing 40 Spool (valve element, displacement transmission member)
44 Inlet port 46 Outlet port

Claims (5)

A linear solenoid part provided in the housing and having a coil, a columnar movable core that is attracted to the fixed core under an energization action on the coil, and a cylindrical yoke surrounding the outer peripheral surface of the movable core;
The movable core is made of a shaftless, and a single bearing for slidably supporting the movable core is provided at an intermediate portion between one end and the other end along the axial direction of the cylindrical yoke. The linear solenoid is provided so as to protrude from the inner peripheral surface of the cylindrical yoke by a predetermined length in a radial inward direction toward the movable core. The linear solenoid according to claim 1,
A single annular recess is provided on the inner peripheral surface of the cylindrical yoke on the fixed core side so that the bearing can be inserted from the fixed core side along the axial direction of the cylindrical yoke. Linear solenoid. The linear solenoid according to claim 1 or 2,
The housing includes a housing bottom provided on one end side along the axial direction of the housing, a cylindrical protrusion extending from the housing bottom, and a protruding bottom extending from the cylindrical protrusion,
The protruding bottom portion is provided with a first stopper member made of a non-magnetic material and restricting one displacement of the movable core, and the first stopper member is a columnar portion that penetrates the through hole of the protruding bottom portion. The linear solenoid is fixed to the projecting bottom by plastic deformation at an inner wall of the projecting bottom. The linear solenoid according to any one of claims 1 to 3,
The fixed core is formed with a recess facing the movable core,
A second stopper member for restricting the other displacement of the movable core is press-fitted into the hole continuous with the recess,
The linear solenoid, wherein the second stopper member is provided with an insertion hole through which a displacement transmission member to which the displacement of the movable core is transmitted. A valve body having a plurality of ports through which the pressure fluid flows;
A linear solenoid according to any one of claims 1 to 4,
A valve mechanism provided in the valve body, and having a valve body that switches between a communication state and a non-communication state between the plurality of ports by displacement of the movable core;
A valve device comprising:

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