JP2001251834A - Electromagnetic drive and solenoid valve using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic drive, which has a mover and a stator which are suitable for the size reduction having a simple structure, while the rated attractive force of a device used as an electromagnetic driving unit is maintained and a solenoid valve which uses the drive. SOLUTION: A stator 10, which has a housing part 12m in which a cylindrical moving member 20 whose ratio of a cylinder length/a cylinder diameter is set to be not less than 1, is housed slidably a permanent magnet 14 is provided so as to be close to the moving member 20 side, and the mover 20 is combined in a part of the housing part 12m. With this structure, an attractive force can be generated in the housing part 12m, particularly in its peripheral part 12mp, so that a gap in the radial direction between the moving member 20 and the housing part 12m can be used as an attraction air gap. Since the attraction air gap is therefore kept always constant, high attractive force can be maintained, regardless of the moving distance of the moving member 20. Furthermore, the smaller the diameter of the moving member 20 is, the larger the attractive force is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic drive device and an electromagnetic valve using the same, and more particularly, to a structure of a stator and a mover constituting a magnetic circuit.

[0002]

2. Description of the Related Art There is an electromagnetic drive device in which a housing for accommodating a mover and a suction unit for sucking the mover are integrally formed (for example, Japanese Utility Model Laid-Open No. 57-164371).

According to Japanese Utility Model Laid-Open Publication No. 57-164371, the magnetic resistance is increased by reducing the thickness of a part of the accommodating portion, and a magnetic flux flows through the mover.

[0004]

In the conventional structure, in order to allow more magnetic flux to flow through the mover in order to obtain a desired attractive force, it is necessary to considerably reduce the thickness of the housing. As a result, the strength of the thinned storage portion is reduced, for example,
In an electromagnetic valve used in a hydraulic control device of an automatic transmission for a vehicle, the housing may be damaged by vibration or the like, and the durability may be impaired.

[0005] In recent years, there has been an increasing demand for increasing the interior space of a vehicle by increasing the density of the engine room from the viewpoint of improving the comfort of the vehicle, and the electromagnetic drive device used for the solenoid valve has been downsized more than ever. Has been requested.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a first object of the present invention is to provide an electromagnetic drive device which increases the attraction force without increasing the size and has excellent durability. An electromagnetic valve using the same is provided.

It is a second object of the present invention to provide an electromagnetic drive device having a mover and a stator with a simple configuration and suitable for miniaturization, and an electromagnetic valve using the same.

[0008]

According to the first and second aspects of the present invention, a thin portion is provided in a housing portion of a stator core for housing a mover, so that a magnetic resistance formed by a magnetic material is reduced. In the stator core to be formed, the magnetic resistance is increased only in a part of the thin portion, and the periphery of the thin portion can be easily magnetically saturated.

Further, permanent magnets are arranged in advance in the thin-walled portion so that the magnetized magnetic flux flows in the same direction as the flow of magnetic flux (hereinafter referred to as coil magnetic flux) generated by energizing the electromagnetic coil. By doing so, the coil magnetic flux generated by energization cannot flow through the thin portion beyond the magnetically unsaturated portion.

For this reason, the flow of the coil magnetic flux does not flow through the thin portion, but flows to the mover side while meandering along the thin portion. Thereby, between the accommodation part of the stator and the mover,
A magnetic circuit can be formed in which the coil magnetic flux flows from one of the housing portions sandwiching the thin portion to the mover, and the magnetic flux flowing along the axial direction of the mover flows again to the other of the housing portions.

Accordingly, the mover moves in the axial direction by the attraction force applied to the coil magnetic flux generated from the housing portion. Moreover, since the air gap that determines the magnitude of the suction force is the radial clearance between the mover and the housing, the air gap does not change even if the cylindrical mover moves. For this reason, a substantially constant suction force is applied to the mover irrespective of the stroke position of the mover, so that the mover can slide toward the far side in the axial direction of the housing portion regardless of the magnitude of the stroke movement. it can.

[0012] For example, in the case of a drive device used for an electromagnetic valve for controlling the hydraulic pressure of an automatic transmission for an automobile, the output hydraulic pressure is controlled by switching the communication of a plurality of fluid passages. Regardless, it is necessary to apply the suction force of the drive device every time communication is switched. For this reason, even in an operation in which the stroke movement amount is small, the thin portion is made of a magnetic flux magnetized by a permanent magnet in advance, so that the movable member slides sideways without much difference from the attractive force applied when the stroke movement amount is large. It is desirable to keep it.

According to the third aspect of the present invention, the permanent magnet is provided at a concave portion provided on the outer periphery of the thin portion so that the magnetic pole of the permanent magnet adjacent in the axial direction and the magnetic pole generated by the electromagnetic coil are provided. By arranging so that the polarity is reversed,
In the thin portion inside the both magnetic poles of the permanent magnet, the flow direction of the magnetic flux magnetized by the permanent magnet can be the same as the flow direction of the coil magnetic flux.

According to a fourth aspect of the present invention, the permanent magnet is provided at a position of the stator core where the flow of the coil magnetic flux is sparse, and the polarity direction of the magnetic pole of the permanent magnet and the electromagnetic coil are arranged. By arranging the polarity direction of the generated magnetic pole in the same direction as the direction of the magnetic flux, the flow direction of the magnetic flux magnetized by the permanent magnet in the thin portion can be the same as the direction of the flow of the coil magnetic flux. The degree of freedom of arrangement increases. For example, if it is provided on the outer periphery of a cylindrical stator core in which the flow of coil magnetic flux is sparse, it is only necessary to fit an annular permanent magnet to the outer periphery. For this reason, there is no need to combine the permanent magnet into two separate parts to form an annular shape.
The number of parts can be reduced without complicating the assembly. Further, the processing cost of the permanent magnet itself can be reduced.

[0015] When the coil magnetic flux is caused to flow through the magnetized permanent magnet itself, the magnetic resistance is high. Therefore, the permanent magnet should be provided in a portion of the stator core where the flow of the coil magnetic flux is low. Thus, a decrease in suction force can be prevented.

According to the fifth aspect of the present invention, the magnetic flux passing through the mover along the periphery of the thin portion of the accommodating portion causes the mover to slide in the axial direction among the circumferential wall surfaces of the concave portion. By forming the circumferential wall on the side where the coil magnetic flux generating force flows at an obtuse angle larger than a right angle, the flow direction of the coil magnetic flux flowing from the mover to the housing along the thin portion of the housing is reduced. Can be tilted toward the axial direction. For this reason, the axial component of the coil magnetic flux increases due to the obtuse peripheral wall surface, so that the attractive force can be increased.

According to the sixth aspect of the present invention, since the projection made of a non-magnetic material is provided inside the accommodating portion, it is possible to regulate the maximum movement amount of the movable element that can move far by the attraction force. The projection is preferably a peripheral wall extending in the circumferential direction. This protrusion may be formed as a non-magnetic material by forming a non-magnetic member on the contact surface with the mover.

According to the seventh aspect of the present invention, the suction force which becomes substantially constant irrespective of the stroke position of the mover is, as the shape of the mover, for example, in a cylindrical shape, the ratio of the cylinder length / diameter is: It is obtained by setting it to 1 or more. Thereby, the mover shape suitable for miniaturization (particularly in the radial direction) can be set.

According to the eighth and ninth aspects of the present invention, since the electromagnetic drive device according to any one of the first to seventh aspects is provided, the stator and the mover suitable for miniaturization are provided. The movable member can be driven by the electromagnetic driving device having the structure.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an electromagnetic drive device according to the present invention and an electromagnetic valve using the same.

(First Embodiment) FIG. 1 is a sectional view showing the structure of an electromagnetic drive device according to the present invention. As shown in FIG. 1, the electromagnetic drive device 1 is configured to include a stator 10, a mover 20, and the like.

The stator 10 includes an electromagnetic coil 11, a stator core 12, and a cylindrical yoke 13 having one end opened.

The mover 20 is formed in a cylindrical shape.
One end 20a is moved by an urging means (hereinafter, referred to as an urging spring) 40 constituting the solenoid valve 2 shown in FIG.
It comes into contact with the mover member 30 (hereinafter, referred to as a spool) which is urged in the zero direction.

The stator core 12, the yoke 13, and the mover 20 are arranged so that a magnetic flux (hereinafter, referred to as a coil magnetic flux) generated when the electromagnetic coil 11 is energized flows.
It is formed of a magnetic material.

The yoke 13 has a caulking portion 13a so that the stator 10 accommodating the mover 20 and the valve element 3 (shown in FIG. 8) described later are integrated to form the electromagnetic valve 2.

The stator 10 and the mover 2 which are features of the present invention
The structure of 0 will be described below. First, stator core 1
2 is provided with a housing portion 12m that accommodates and supports the mover 20 in a reciprocating manner, and a protrusion 12s that regulates a mechanical movement amount by which the mover 20 can move to an axially distant inner periphery of the accommodation portion 12m. ing. The projection 12s forms a peripheral wall that protrudes into the housing 12m.

In order to prevent the accommodation portion 12m and the mover 20 from sticking in the radial direction, the inner peripheral surface of the accommodation portion 12m or the outer peripheral surface of the mover 20 is coated or plated with a non-magnetic material. . Further, a non-contact member 15 made of a non-magnetic material is provided at an end of the projection 12s on the side of the movable element 20 in order to prevent close contact with the movable element 20 in the axial direction.

Next, on the outer circumferential surface of the accommodating portion 12m,
An annular recess 16 is formed. The magnetic resistance of the thin portion 12ma forming the concave portion 16 is increased in inverse proportion to the thickness of the housing portion. For this reason, compared with the other part of the accommodating part 12m, the periphery of the thin part is easily magnetically saturated.

The permanent magnet 14 is provided in the concave portion 16 on the outer peripheral surface of the thin portion 12ma so that the polarity of the magnetic pole generated by the electromagnetic coil 11 and the polarity of the magnetic pole of the permanent magnet 14 adjacent in the radial direction are opposite to each other. Is located. For example, as shown in FIG. 1, when a current such that one of the magnetic poles is an S pole is passed through the electromagnetic coil in the magnetic pole generated by the electromagnetic coil, the magnetic pole 14a of the permanent magnet adjacent in the radial direction is an N pole. What is necessary is just to arrange the permanent magnet 14 so that it may become. Note that the combination of the magnetic pole of one of the electromagnetic coils adjacent to the radial direction and the magnetic pole of the permanent magnet only needs to have a relationship of opposite polarities in which the N pole and the S pole are arranged.

As a result, the magnetic flux magnetized by the permanent magnet 14 can flow in the same direction as the flow of the coil magnetic flux in the thin portion 12ma even when the coil is not energized without generating the magnetic flux. For this reason, at the time of energization, the coil magnetic flux cannot flow through the thin portion 12 ma beyond the amount of magnetic unsaturation up to magnetic saturation.

It is desirable that the thin portion 12ma is magnetically saturated by the magnetic flux generated by the permanent magnet 14 from the mechanism for generating the attraction force in the operation of the electromagnetic drive device 1 described later.

The permanent magnet 14 is composed of a plurality of arc-shaped magnets and is assembled in an annular shape. It is desirable to mount two half-arc magnets as an assembly structure by combining a plurality of arcs because the number of parts can be reduced and the assembly is simple.

Further, with respect to the thickness of the thin portion 12ma, magnetic saturation can be achieved by changing the strength of the magnetic force of the permanent magnet 14 in advance according to the thickness. Therefore, the thickness of the thin-walled portion 12ma is
By adjusting the magnetic force of No. 4, the mechanical strength can be set to such an extent that the mechanical strength is not impaired.

Next, the electromagnetic coil 11 will be described below. The electromagnetic coil 11 is molded into a cylindrical shape with a resin, and is fixed by a stator core 12 and a yoke 13. The electromagnetic coil 11 generates a coil magnetic flux when a current is supplied from a terminal (not shown) electrically connected to the electromagnetic coil 11.

Further, with respect to the mover 20, the combination requirements of the stator 10 and the mover 20 suitable for miniaturization are as follows.
explain. From a mechanism for generating a suction force in the description of the operation of the electromagnetic drive device 1 described later, as a movable element shape capable of obtaining a substantially constant attractive force regardless of the moving position of the movable element, for example,
In the cylindrical mover 20, the ratio of the cylinder length / diameter (L / D shown in FIG. 2) is desirably 1 or more. Also,
By increasing L / D, it is possible to increase the suction force. For this reason, when the size is reduced, the suction force characteristics can be optimized, which is suitable for the size reduction.

Further, in combination with the mover 20 having a small diameter and suitable for miniaturization, the thin portion 1 of the stator 10
2ma preferably has the following features. From the generation mechanism of the attraction force in the description of the operation of the electromagnetic drive device 1 described below, the coil magnetic flux flows from one side of the housing portion 12m to the mover 20 side along the periphery of the thin portion 12ma of the housing portion 12m, By returning to the other side of the accommodating portion 12m again, the suction force for causing the movable element 20 to slide sideways is reduced.
It occurs in the accommodation section 12m around ma. For this reason, in the magnetic flux vector component of the coil magnetic flux, the axial magnetic flux vector component that flows through the mover 20 having a smaller diameter D and moves the mover 20 farther in the axial direction is increased, so An inclined surface 1 forming an obtuse angle by inclining a part or all of a circumferential wall surface forming a concave portion without making it a straight wall.
7 bs is desirable.

Here, the operation of the electromagnetic driving device 1 of the present invention,
In particular, a mechanism for generating a suction force acting on the stator 10 and the mover 20 will be described below with reference to FIGS. FIG. 2 shows the flow of coil magnetic flux between the stator 10 and the mover 20 constituting the electromagnetic drive device 1 of the present invention, and the ratio of the cylinder length / diameter (hereinafter, referred to as L / D) of the mover 20 is shown. FIG. 9 is a characteristic diagram for comparing the flow of the coil magnetic flux in a different manner. FIG.
3 is a characteristic diagram showing the magnitude of the attraction force of the mover of the present invention in a comparative example in which the L / D ratio of the mover 20 in FIG. 2 is changed. FIG. 4 shows an analysis result of the flow of the magnetic flux flowing between the accommodating portion 12m and the mover 20 performed to verify which part of the electromagnetic drive device 1 of the present invention is affected by the suction force. FIG. 9 is a schematic characteristic diagram showing a suction force applied to the motor 20 by a magnitude of a suction force component for each local area.

In FIG. 2, (A) shows a case where L / D = 0.5, (B) shows a case where L / D = 1.0, and (C) shows a case where L / D = 1.0.
4 shows the flow of coil magnetic flux between the stator and the mover when D = 1.5. Here, the number of turns of the electromagnetic coil × current (hereinafter, N
× I) is set to be constant. As shown in FIGS. 2A to 2C, basically, the flow of the coil magnetic flux flows from one of the accommodating portions 12m so as to follow the periphery of the thin portion 12ma of the accommodating portion 12m. This forms a magnetic circuit that flows to the side and flows again to the other side of the housing 12m. As described above, since the thin portion 12ma is magnetically saturated by the magnetic flux of the permanent magnet 14,
The coil magnetic flux does not flow through the magnetically saturated thin portion 12ma and the permanent magnet 14 having the opposite magnetic poles. Instead, it shows the flow of magnetic flux that flows toward the mover 20 along the periphery of the thin portion 12ma and penetrates the mover. In addition,
In FIG. 2, of the coil magnetic fluxes forming the magnetic circuit, the magnetic flux flowing meandering from one side of the accommodating portion 12m to the mover 20 side is hereinafter referred to as a coil magnetic flux Φ1, and the mover 2
The magnetic flux flowing meandering to the 0 side and flowing again to the other side of the housing portion 12m is called a magnetic flux Φ2 and is distinguished.

Next, referring to FIG. 3, the moving amount of the mover is shown by using (A) to (C) in which the L / D ratio shown in FIG. 2 is changed and a comparative example of L / D = 0.75. As shown in the characteristic diagram showing the relationship between the stroke and the suction force, when L / D = 0.5, a negative suction force is generated in the initial stroke portion.
This indicates that at the beginning of the stroke, the mover 20 does not move to the desired one side in the axial direction, but is instead attracted to the other side in the axial direction. This indicates that there is a dead zone in which the mover cannot move even if suction cannot be performed. Unnecessary current for moving the mover 20 by generating a suction force against the dead zone is consumed, so that the suction force is also small. When L / D = 0.75, no negative suction force is generated as compared with L / D = 0.5, but the generated suction force is small in the initial stroke. For example, when applied to an electromagnetic drive device that switches and controls communication of a plurality of fluid passages, such as an electromagnetic drive device used for a hydraulic control electromagnetic valve of an automatic transmission for an automobile,
L / D = 0.75, which is inferior to other strokes, is not preferable because it is necessary to generate a suction force capable of switching the communication passage regardless of the stroke position of the mover. In addition, L / D = 0.75 is not preferable for a combination structure of a mover and a stator suitable for miniaturization. On the other hand, when L / D = 1.0, a substantially constant suction force is obtained from the beginning of the stroke. Further L / D
= 1.5, a larger suction force can be obtained, and a substantially constant suction force can be obtained regardless of the stroke position. When the present invention is applied to the above-described electromagnetic drive device that switches and controls the communication of the plurality of fluid passages, the L / D ratio may be 1 or more.

Further, when the L / D ratio of the mover 20 is changed, the manner of action of the attraction force acting between the stator and the mover is shown by decomposing the attraction force generated in FIG. This will be described below with reference to a characteristic diagram showing the magnitude of the suction force component. (A) to (C) in FIG. 4 are the same as (A) to (C) in which the L / D ratio in FIG. 2 is changed. Arrow P in FIG. 4 indicates a desired moving direction of the mover. The suction force acting toward the housing 12m due to the flow of the magnetic flux Φ1 is hereinafter referred to as the suction force F1, and the suction force acting on the housing 1 by the flow of the magnetic flux Φ2.
The suction force acting toward 2 m is hereinafter referred to as a suction force F2. When L / D = 0.5 in (A), the axial components of the attraction force act on the mover 20 together with the attraction forces F1 and F2, which are in opposite relation. From this, even if a current is supplied to the electromagnetic coil to generate a coil magnetic flux, the attracting force F1 and the attracting force F2, which are opposite to each other, cancel each other out, so that the mover 20 is moved in the axial direction. Is small because it is used for unnecessary consumption that generates a suction force in which the supplied currents cancel each other. Note that L / D in FIG.
The case of 0.75 may be considered to correspond to this. Further, when L / D = 0.5, a negative suction force is generated because F1 having a suction force component in a direction opposite to a desired moving direction is larger than F2. For this reason, even if the coil magnetic flux is generated, the above-mentioned dead zone in which the mover does not move in the desired moving direction occurs, and thus the performance of the electromagnetic driving device is impaired. In contrast, the L / D ratio is
L / D of (B) which is 1 or more = 1.0 and L / (C)
In the case of /D=1.5, F2 having the suction force component in the same direction as the desired moving direction is large, and F1 having the suction force component in the direction opposite to the desired moving direction is small. . For this reason, the magnetic flux Φ2 meandering toward the mover 20 and flowing again toward the accommodating portion 12m forms an attractive force for attracting the mover 20 to a desired distance in the axial direction. In other words, the thin portion 12ma and the peripheral portion 12m of the circumferential wall surface 17b on the side where Φ2 flows among the circumferential wall surfaces 17 sandwiching the concave portion 16 on the outer peripheral surface of the thin portion 12ma.
At p, an attraction force that determines the performance of the electromagnetic drive device is generated.

Further, the stator 10 having the inclined surface 17bs provided to incline the flow direction of the coil magnetic flux in the axial direction.
And the mover 20, the direction of the magnetic flux passing through the mover 20 can be inclined in the axial direction.

For example, the flow of the magnetic flux flowing through the mover 20 while meandering along the thin portion 12ma in FIG. (A) L /
Ra when D = 0.5, Rb when L / D = 1.0 in (B), and R in Rc when L / D = 1.5 in (C)
Compared with c, when L / D = 0.5 in (A), the radius of curvature Ra is small and the direction of the magnetic flux is rapidly changed. On the other hand, L / D of (B) where L / D is 1.0 or more
= 1.0 or L / D = 1.5 in (C), the radius of curvature R increases as the L / D ratio increases. This alleviates the sudden change in the flow direction of the magnetic flux, so that the flow direction of the coil magnetic flux is inclined in the axial direction.

In the present embodiment, in order to fit the permanent magnet 14 into the recess 16 and assemble it, an inclined surface 17bs forming an obtuse angle with respect to the housing axis is formed on a part of the circumferential wall surface 17b. Although the magnetic flux flowing in the peripheral part 12mp was made to follow,
The circumferential wall surface 17b may be formed so as to form an obtuse angle with respect to the housing axis to form the inclined surface 17bs.

Further, in the structure of the stator and the mover of the present invention, as described above, the mover 20 and the mover 20 are formed as an air gap through which the magnetic flux Φ2 for generating the attraction force for moving the mover 20 in the axial direction flows. The clearance of the sliding portion of the accommodated stator 10 forms a suction air gap. Thus, the suction air gap does not change regardless of the stroke position where the mover 20 moves. Therefore, a constant suction force can be obtained irrespective of the amount of movement of the mover 20, so that it is suitable for, for example, an electromagnetic drive device that switches and controls communication of a plurality of fluid passages, and can be downsized. An electromagnetic drive device can be provided.

(Modification) FIG. 5 shows an embodiment in which a simple configuration is provided by a structure of a stator and a mover suitable for miniaturization.
A modification will be described with reference to FIG.

As for the structure, only the arrangement of the permanent magnets 114 and the component shapes thereof are different from the embodiment shown in FIG. First, in the modified example, instead of assembling a plurality of arc magnets in an annular shape, the component shape of the permanent magnet 114 is made of an annular magnet. As shown in FIG. 5, the permanent magnet 114 is fitted to, for example, the outer peripheral portion 12t of the stator core. The position of the permanent magnet 114 may be anywhere as long as the flow of the coil magnetic flux is reduced. As shown in FIG. 5, the permanent magnets 114 are arranged such that the polarity direction of the magnetic poles of the permanent magnets 114 and the polarity direction of the magnetic poles generated by the electromagnetic coil are the same as the direction in which the magnetic flux flows. In addition, the magnetic force of the permanent magnet 114 may be increased in the thin portion 12m so that the magnetic flux of the same direction as the flow of the coil magnetic flux and magnetized by the permanent magnet 114 is magnetically saturated. Only by this, the same effect as the embodiment shown in FIG. 1 can be obtained.

Therefore, since the permanent magnets 114 have a degree of freedom in arrangement and the annular permanent magnets 114,
A simple electromagnetic drive device capable of reducing the number of parts can be provided.

(Second Embodiment) The structure of the second embodiment will be described with reference to FIG. FIG. 6 is a sectional view of the electromagnetic driving device according to the embodiment of the present invention. The difference from the structure of the first embodiment is that the adhesion preventing members 115 provided at both ends of the projection 12s are integrally formed. This embodiment can achieve the same effects as those of the first embodiment shown in FIG.

Similarly, for the terminal (not shown), a connector integrated with the terminal is formed on the electromagnetic drive device by molding with a resin. This provides an electromagnetic drive device that is simple and suitable for miniaturization.

(Embodiment of Electromagnetic Valve Using Electromagnetic Drive) An electromagnetic valve using the electromagnetic drive of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. FIG. 7 is a cross-sectional view illustrating a structure of an electromagnetic valve using the electromagnetic driving device according to the second embodiment.

The solenoid valve 2 is a spool-type hydraulic control valve that controls the hydraulic pressure of hydraulic oil supplied to a hydraulic control device of an automatic transmission such as a vehicle. The electromagnetic valve 2 includes an electromagnetic drive device 1, a valve element 3 that is driven by the electromagnetic drive device 1, switches communication between a plurality of fluid passages, and obtains an output hydraulic pressure. The electromagnetic driving device 1 is a second embodiment of the electromagnetic driving device of the present invention shown in FIG.
The reference numerals are likewise shown in FIG. Therefore, the electromagnetic drive 1
The structure and operation are as described above.

First, the structure of the electromagnetic valve 2 using the electromagnetic driving device 1 of the present invention will be described. The electromagnetic drive device 1 and the valve body 3 are
As described above, the caulking portion 13a serving as an open end of the yoke 13 constituting the electromagnetic drive device is caulked to integrally form the electromagnetic valve 2.

Next, the valve element 3 will be described below. The valve element 3 includes a spool 30, a housing 31, and an urging spring 40 which is urging means for urging the spool 30 toward the movable element 20 housed in the electromagnetic drive device 1. The housing 31 accommodates and supports the spool 30 so as to be reciprocally movable. The housing 31 includes an input port (hereinafter, referred to as an input port) 32, an output port (hereinafter, referred to as an output port) 33, a feedback port (hereinafter, a feedback port) 34, and a discharge port (hereinafter, referred to as an output port). Discharge port). The input port 32 is a port into which hydraulic oil supplied from a tank (not shown) by a pump (not shown) flows. The output port 33 is a port for supplying hydraulic oil to an engagement device (not shown) of the automatic transmission. The output port 33 and the feedback port 34 communicate with each other outside the solenoid valve 2, and a part of the operating oil flowing out of the output port 33 is introduced into the feedback port 34. The feedback chamber 36 communicates with the feedback port 34. The discharge port 35 is a port for discharging hydraulic oil to the tank.

On the spool 30, a large-diameter land 37, a large-diameter land 38, and a small-diameter land 39 are arranged in this order from the far side with respect to the electromagnetic drive device 1. Small diameter land 39 has a smaller outer diameter than large diameter lands 37 and 38. The spool 30 has one end 20a of the mover 20 and the distal end portion 30a constantly in contact with each other, and the axial movement of the mover 20 is transmitted to reciprocate in the housing 31.

The feedback chamber 36 has a large-diameter land 38.
And a small-diameter land 39. For this reason,
Since the area on which the feedback hydraulic pressure acts differs according to the difference in the outer diameter of the land, the hydraulic pressure in the feedback chamber 36 acts to press the spool 30 toward the biasing spring 40 in the axial direction. The reason why a part of the output hydraulic pressure is fed back in the solenoid valve 2 is to prevent the output pressure from fluctuating due to the fluctuation of the supplied hydraulic pressure, that is, the input pressure. Therefore, spool 3
0 is a driving force for pushing the spool by attracting the mover 20 toward the biasing spring 40 in the axial direction by the biasing force of the biasing spring 40 and the coil magnetic flux generated by the stator 20 by supplying the current. At a position where the force received by the spool 30 by the hydraulic pressure of the feedback chamber 36 is balanced.

The amount of hydraulic oil flowing from the input port 32 to the output port 33 is determined by the seal length defined by the length of the overlapping portion between the inner peripheral wall 31a of the housing 31 and the outer peripheral wall of the large-diameter land 38. When the seal length becomes short, the amount of hydraulic oil flowing from the input port 32 to the output port 33 increases, and when the seal length becomes long, the hydraulic oil flows from the input port 32 to the output port 33.
The amount of hydraulic oil flowing to the tank decreases. Similarly, output port 33
The amount of hydraulic oil flowing from the housing to the discharge port 35 depends on the housing 3
The seal length is determined by the seal length between the inner wall 31b of FIG.

When a current is applied, a coil magnetic flux is generated in the stator 20, and when the movable element 20 is attracted toward the biasing spring 40 in the axial direction to push the spool, the inner peripheral wall 31 is pressed.
a and the seal length between the large diameter land 38 and the inner peripheral wall 31 are increased.
Since the seal length between b and the large-diameter land 37 is shortened, the amount of hydraulic oil flowing from the input port 32 to the output port 33 decreases, and the amount of hydraulic oil flowing from the output port 33 to the discharge port 35 increases. As a result, the hydraulic pressure of the working oil flowing out of the output port 33 decreases.

On the other hand, the spool 30 is
When moving toward the 0 side, that is, in the axial direction on the drive device 1 side, the seal length between the inner peripheral wall 31a and the large-diameter land 38 becomes shorter and the seal length between the inner peripheral wall 31b and the large-diameter land 37 becomes longer. The amount of hydraulic oil flowing from the port 32 to the output port 33 increases, and
The amount of hydraulic oil flowing to the tank decreases. As a result, output port 3
The hydraulic pressure of the hydraulic oil flowing out of the pump 3 increases.

The solenoid valve 2 controls the value of the current supplied to the stator 10 so that the spool 30
Is adjusted toward the urging spring 40 side, the hydraulic pressure of the hydraulic oil flowing out of the output port 33 can be adjusted. When the value of the current supplied to the stator 20 is increased, the attraction force increases in proportion to the current value, and the driving force of the mover 20 that contacts the spool 30 and pushes toward the biasing spring 40 increases. For this reason, the spool 30 is driven by the driving force for pushing the spool 30 toward the urging spring 40 by the attraction force that increases in proportion to the current value, the urging force of the urging spring 40, and the pressure of the hydraulic oil fed back. The spool 30 stops at a position where the force pushed toward the urging spring 40 balances. Therefore, the hydraulic pressure of the working oil flowing out of the output port 33 can be reduced in proportion to the value of the current supplied to the electromagnetic drive device 1.

Next, the operation of the solenoid valve 2 will be described below separately for when the electromagnetic drive device is not energized and when it is energized.

(1) At the time of non-energization As shown in FIG. 7, the spool 30 stops at the position where the urging force of the urging spring 40 and the force acting by the hydraulic feedback are balanced. Thereby, the input port 32 and the output port 33 communicate with each other, and the flow rate of the hydraulic oil flowing from the input port 32 to the output port 33 increases, and the discharge port 35 is closed. The pressure is at a maximum.

The thin portion 12ma and the peripheral portion 12mp of the circumferential wall surface 17b of the concave portion 16 are magnetically saturated by the magnetic flux magnetized by the permanent magnet 14. From the mechanism for generating the attraction force in the description of the operation of the electromagnetic drive device 1 described above, since the attraction force is not generated only by magnetic saturation, the drive force of the electromagnetic drive device is zero.

(2) At the time of energization From the generation mechanism of the attraction force in the description of the operation of the electromagnetic drive device 1,
The coil magnetic flux does not flow in the magnetically saturated thin portion 12ma, but instead flows meandering to the mover 20 side along the periphery of the thin portion 12ma. This meandering flow of the magnetic flux Φ2 flowing from the mover 20 toward the peripheral portion 12mp generates an attraction force for moving the mover 20 to a position farther from the biasing spring 40 in the axial direction. The suction force generates a driving force of the electromagnetic drive device 1 that pushes the spool 30 abutting on the mover 20 toward the urging spring 40. At this time, the following control of the electromagnetic valve 2 is performed by changing the current value supplied to the electromagnetic drive device 1.

Hydraulic Oil Discharge Control When the supplied current is maximized, the suction force of the mover 20 for driving the spool 30 is maximized, and the urging spring 40
The spool 30 is moved against the urging force. Thereby, the input port 32 is closed, and the flow rate of the hydraulic oil flowing from the output port 33 to the discharge port 35 increases, so that the pressure of the hydraulic oil supplied to the automatic transmission becomes zero (equivalent to the atmospheric pressure).

Hydraulic oil output control When the supplied current is controlled to be smaller than the state, the suction force proportional to the current value becomes small, and the spool 30 moves to the state described in (1) above. (2)
It moves to a position halfway between the states and stands still. As described above, the seal length formed by the inner peripheral wall 31a and the large-diameter land 38 of the housing 31 and the inner peripheral wall 31b and the large-diameter land 37 change, as described above. The pressure changes. Therefore, by controlling the current supplied to the electromagnetic drive device 1, the position of the spool 30 changes, and the pressure of the hydraulic oil supplied to the automatic transmission can be adjusted.

The feature of the stator 10 and the mover 20 of the drive device 1 of the present invention is that the mechanism for generating the attraction force described in the above description of the operation of the electromagnetic drive device 1 moves from the mover 20 to the peripheral portion 12mp. In the suction force generated by the flow of the magnetic flux Φ2 flowing through the
0 and the clearance of the sliding portion of the stator 10 accommodating it. Therefore, the suction air gap does not change irrespective of the stroke position where the mover 20 moves, so that a constant suction force can be obtained according to the supplied current regardless of the amount of movement of the mover 20. Can be That is, regardless of the stroke position where the mover 20 moves,
Since the suction air gap has a structure that does not change, it is an electromagnetic drive device suitable for obtaining a suction force proportional to the supplied current value.

Further, since the stator 10 and the mover 20 have a combination structure suitable for downsizing, the above-mentioned condition for the spool 30 of the hydraulic control valve element 3 is satisfied.
If the required driving force of the electromagnetic drive device 1, that is, the target suction force required for the design is set, the size of the electromagnetic drive device 1 can be reduced while securing the target suction force. Accordingly, the physical size of the electromagnetic valve 2 on which the miniaturized electromagnetic drive device 1 is mounted can be reduced.

In the present embodiment, the electromagnetic drive unit of the present invention is used for the electromagnetic drive unit of the spool-type hydraulic control valve. However, other than this, the one that increases the suction force without increasing the physical size, or If it is intended to reduce the size of the electromagnetic drive device and the solenoid valve using the same while securing the necessary suction force,
The electromagnetic drive device of the present invention may be used for any electromagnetic valve or device drive device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of an electromagnetic drive device according to a first embodiment of the present invention.

FIG. 2 shows the flow of coil magnetic flux between the stator and the mover in FIG. 1, and compares the flow rate of the coil magnetic flux by changing the ratio of the cylinder length / diameter (L / D) of the mover. It is a characteristic diagram.

FIG. 3 is a characteristic diagram showing the magnitude of the attraction force of the mover of the present invention in a comparative example in which the ratio of L / D of the mover in FIG. 2 is changed.

FIG. 4 is a diagram showing the results of analysis of the flow of magnetic flux flowing between the accommodating portion and the mover performed to verify which portion of the suction force is acting on the mover in the electromagnetic drive device of the present invention. FIG. 7 is a schematic characteristic diagram showing a suction force by a magnitude of a suction force component for each local part.

FIG. 5 is a sectional view of a modification of the first embodiment.

FIG. 6 is a sectional view of an electromagnetic drive device according to a second embodiment.

FIG. 7 is a cross-sectional view illustrating a structure of an electromagnetic valve using the electromagnetic driving device according to the second embodiment.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 electromagnetic drive device 2 electromagnetic valve (electromagnetic valve using electromagnetic drive device) 3 valve element 10 stator 11 electromagnetic coil 12 stator iron core 12 m accommodating portion 12 ma thin portion 12 mp peripheral portion (moves mover 20 in the axial direction far 12s Projection 13 Yoke 14, 114 Permanent Magnet 15, 115 Adhesion Prevention Member 16 Recess (Circumferential recess forming outer peripheral surface of thin portion 13) 17 Circumferential wall surface 17b sandwiching recess Of the circumferential wall surfaces sandwiching the recess, the circumferential wall surface on the side on which the magnetic flux Φ2 for generating the attraction force flows 17bs Inclined surface 20 Movable element 30 Movable member (spool) 40 Urging member (urging spring)

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (9)

[Claims] 1. An electromagnetic drive device comprising: an electromagnetic coil for generating an attractive force; a stator having a stator core; a slidable mover accommodated in the stator core; and a permanent magnet. The mover has a cylindrical shape, and the stator iron core is provided with a thin-walled portion in which a circumferential outer peripheral surface is a concave part in a part of a cylindrical housing portion that houses the mover, The permanent magnet magnetized so that the magnetic flux flows through the thin portion in the same direction as the flow of the magnetic flux generated by energizing the electromagnetic coil, and the movable element can move in the axial direction of the housing portion. Powerful suction power
An electromagnetic drive device, wherein the drive is generated in the housing section. 2. The electromagnetic device according to claim 1, wherein the thin portion is magnetically saturated by a magnetic flux magnetized by the permanent magnet flowing even when power is not supplied to the electromagnetic coil. Drive. 3. The electromagnetic drive device according to claim 1, wherein the permanent magnet is provided in the recess. 4. The apparatus according to claim 1, wherein the permanent magnet is provided on the stator core, and is disposed at a position where the flow of magnetic flux generated by energizing the electromagnetic coil is sparse. The electromagnetic drive device according to claim 1. 5. A peripheral wall surface of the concave portion on the side where the magnetic flux generating the attraction force flows is inclined so as to expand in the axial direction. The electromagnetic drive device according to claim 1. 6. The electromagnetic driving device according to claim 1, wherein the housing portion has a protrusion for restricting movement of the mover by the attraction force. . 7. The mover according to claim 1, wherein the mover has a substantially cylindrical shape, and a ratio of the length / diameter of the mover is 1 or more. Electromagnetic drive. 8. A valve housing having a plurality of fluid passages penetrating a cylindrical peripheral wall, the electromagnetic drive device according to any one of claims 1 to 7, and reciprocating with the mover. And a biasing means for biasing the movable member in a direction opposite to a direction in which the movable element is sucked. 9. The solenoid valve according to claim 8, wherein the output hydraulic pressure is controlled.