JP2001068335A - Electromagnetically driving device and electromagnetic valve using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetically driving device and an electromagnetic valve using the electromagnetically driving device capable of increasing its attracting force without increasing its structure, and of preventing the damaging of the housing section. SOLUTION: A housing section 14 for guiding a plunger 17 in a reciprocating manner is formed integrally with an attracting section 15 for generating an attracting force with respect to the plunger 17. A permanent magnet 25 is fitted into a recess 14a formed in the outer circumferential wall of the section 14. A thin-walled section 16 is magnetically saturated by a magnetic flux generated by the magnet 25. The magnetic flux generated by the magnet 25 flows through the section 16 in the same direction as a magnetic flux generated by a coil 20 flows through the section 16 when the coil 20 is energized. The magnetic flux generated by the coil 20 when the coil 20 is energized does not pass through the section 16 which is magnetically saturated, but flows from the section 14 to the plunger 17, and from a tapered section 17a of the plunger 17 toward a tapered section 15b of the section 15, whereby the force for attracting the plunger 17 is increased.

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 in which a housing for accommodating a mover and a suction unit for sucking the mover are integrally formed, and an electromagnetic valve using the same.

[0002]

2. Description of the Related Art In a conventional solenoid valve in which a stator is constituted by separately providing a housing for accommodating the mover and a suction unit for sucking the mover, the axis of the housing and the suction unit are aligned. It may shift due to an assembly error or the like. The air gap formed between the housing part and the mover, and the air gap formed between the suction part and the mover is axial so that the reciprocating movement of the mover is not hindered even if the axis of the housing part and the suction part are shifted. It is formed large considering the misalignment. As the air gap increases, the suction force decreases, so it is necessary to increase the number of turns of the coil to obtain a desired suction force. However, there is a problem that increasing the number of turns of the coil increases the size of the electromagnetic drive device.

[0003]

There is known an electromagnetic drive device in which the housing portion and the suction portion are formed integrally by, for example, cutting or the like in order to eliminate the axial center deviation between the housing portion and the suction portion. However, if the accommodating portion and the suction portion are formed integrally, the magnetic flux generated by turning on the current to the coil (hereinafter, the magnetic flux generated by turning on the current to the coil) is referred to as a coil magnetic flux. Accordingly, a magnetic flux flows between the housing portion and the suction portion without flowing between the stator and the mover, and the suction force is reduced. Therefore, by fitting a non-magnetic member to a part of the housing part and increasing the magnetic resistance of the thinned housing part,
It is conceivable that the magnetic flux flowing between the housing part and the suction part is caused to flow to the mover. However, in order to allow a large amount of magnetic flux to flow through the mover by reducing the thickness of the housing portion into which the non-magnetic member is fitted, it is necessary to considerably reduce the thickness of the housing portion. As a result, the strength of the thinned storage section is reduced, and the storage section may be damaged.

An object of the present invention is to provide an electromagnetic drive device which increases a suction force without increasing the size and prevents damage to a housing portion, and an electromagnetic valve using the same. Another object of the present invention is to provide an electromagnetic drive device for preventing a change in suction force and an electromagnetic valve using the same. Another object of the present invention is to provide an electromagnetic drive device in which a permanent magnet can be easily assembled, and an electromagnetic valve using the same.

[0005]

According to the electromagnetic drive device of the present invention, the accommodating portion for accommodating the mover and the magnetic force for attracting the mover in one direction of the reciprocating movement are generated by the mover. It is provided with a stator integrally formed with a suction part working therebetween. Since the accommodating portion and the suction portion can be cut, for example, continuously, there is no deviation of the axis between the accommodating portion and the suction portion. Therefore, the air gap formed by the accommodating portion and the suction portion and the mover in the radial direction can be minimized. Thereby, the suction force acting between the suction unit and the mover increases.

Further, since a permanent magnet is provided which generates a magnetic flux flowing in the accommodating portion in the same direction as the coil magnetic flux, the coil magnetic flux flows through the portion of the accommodating portion in which the magnetic flux of the permanent magnet flows in the same direction as the coil magnetic flux. Is hindered. Then, avoid the part of the housing part where the magnetic flux of the permanent magnet flows in the same direction as the coil magnetic flux. A large amount of magnetic flux flows between the child and the child. Thus, the suction force acting between the housing and the mover increases. The thickness of the housing part in which the magnetic flux of the permanent magnet flows in the same direction as the coil magnetic flux can be made thick enough not to impair the mechanical strength by adjusting the magnetic force of the permanent magnet. Can be prevented.

When a permanent magnet is attached to a portion of the stator other than the housing portion, a portion where the magnetic flux of the permanent magnet is large and the coil magnetic flux is difficult to flow may be generated in the stator other than the housing portion. Then, since the amount of coil magnetic flux flowing through the entire stator decreases, sufficient magnetic flux does not flow between the accommodating section and the movable element, and between the movable element and the attracting section, and the attractive force decreases.

Therefore, according to the electromagnetic drive device of the second aspect of the present invention, since the permanent magnet is attached to the housing,
A portion where the coil magnetic flux is difficult to flow is prevented from being generated in the stator other than the housing portion, and a decrease in the amount of coil magnetic flux flowing through the entire stator is prevented. Therefore, the accommodating part and the mover,
In addition, since a large amount of magnetic flux flows between the attraction unit and the mover, the attraction force increases. According to the electromagnetic drive device of the third aspect of the present invention, the concave portion for fitting the permanent magnet is provided on the outer peripheral wall of the housing portion. Therefore, even if a permanent magnet is used, the attraction force can be increased without increasing the size of the electromagnetic drive device.

The fact that the direction of the coil magnetic flux flowing through the housing and the direction in which the magnetic flux generated by the permanent magnet fitted in the recess formed in the outer peripheral wall of the housing flows through the housing is the same. This means that the direction of the coil magnetic flux flowing through the portion and the direction of the magnetic flux flowing inside the permanent magnet, that is, the magnetization direction of the permanent magnet, are opposite. The coil magnetic flux flowing between the mover and the attracting portion tends to pass through the inner peripheral corner on the attracting portion side of the permanent magnet fitted into the recess formed in the housing portion. If the inner corner of the permanent magnet at the side of the attracting portion is not cut off, the coil magnetic flux flowing between the attracting portion of the stator and the mover at the time of high temperature causes the inner peripheral corner of the attracting portion of the permanent magnet at the side of the permanent magnet. , The inner peripheral side corner of the permanent magnet on the attracting portion side is demagnetized, and the attractive force for attracting the mover changes.

According to the fourth aspect of the present invention, since the notch is formed in the inner peripheral corner on the attracting portion side of the permanent magnet, the gap between the attracting portion of the stator and the movable element is formed. The flowing coil magnetic flux does not pass through the inner peripheral corner on the attracting portion side of the permanent magnet. For this reason, demagnetization of the permanent magnet is prevented, and the attraction force for attracting the mover is substantially constant, so that the displacement of the mover can be controlled with high accuracy. According to the electromagnetic drive device of the fifth aspect of the present invention, since the inner corners of the permanent magnet are cut off, there is no need to consider the orientation when assembling the permanent magnet, and the assembling becomes easier.

Since the magnetic permeability of the permanent magnet is small and the magnetic resistance is large, if the permanent magnet is arranged in the magnetic path through which the coil magnetic flux flows, the permanent magnet becomes a magnetic resistance and the magnetic flux is difficult to flow. Further, if a permanent magnet is to be fitted into a concave portion formed on the outer peripheral wall or the inner peripheral wall of the stator, for example, an annularly formed permanent magnet cannot be assembled into the concave portion. Therefore, it is necessary to use a permanent magnet composed of a plurality of magnet pieces. However, assembling a plurality of magnet pieces increases the number of assembling steps.

Therefore, according to the electromagnetic drive device of the present invention, the permanent magnet is attached to the axial end of the portion where the stator accommodating portion and the attracting portion are integrally formed. You can pass around the magnet.
Therefore, the suction force of the mover can be improved. Furthermore, for example, an integrally formed annular permanent magnet can be assembled to the stator from one axial direction, so that the number of parts of the permanent magnet can be reduced, the permanent magnet can be easily assembled, and the processing of the permanent magnet can be performed. Costs can be reduced. Claim 7 of the present invention
According to the electromagnetic drive device described above, the annular permanent magnet can be easily assembled by using one annular permanent magnet or a plurality of arc-shaped permanent magnets.

According to the electromagnetic drive device of the present invention, when energization of the coil is turned off, a part of the housing facing the mover causes a part of the housing to move in the same direction as the coil magnetic flux. Is magnetically saturated by the magnetic flux of the permanent magnet flowing through. The coil magnetic flux does not flow between the housing section and the suction section, but flows between the housing section and the mover, and between the suction section and the mover. Therefore, the attraction force of the electromagnetic drive device increases. According to the electromagnetic valve according to the ninth or tenth aspect of the present invention, since the electromagnetic drive device according to any one of the first to eighth aspects is provided, the movable member can be driven without increasing the size of the electromagnetic valve. Power can be increased.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIG. 1 shows a solenoid valve according to a first embodiment of the present invention.
Shown in The solenoid valve 1 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. Linear solenoid 1 as electromagnetic drive
Numeral 0 has a cylindrical yoke 11, an end plate 12, a stator core 13, a plunger 17 as a mover, a shaft 18, a coil 20, and the like. The yoke 11 and the stator core 13 constitute a stator. Yoke 11, end plate 12, stator core 13, plunger 17
Is formed of a magnetic material.

The yoke 11 fixes the stator core 13 between the end plate 12 and the housing 31 by caulking the end of the end plate 12 with the housing 31 that supports the spool 30 so that the spool 30 can reciprocate.
The stator core 13 has an accommodating portion 14 for accommodating and supporting the plunger 17 reciprocally, and a suction portion 15 for generating a force for attracting the plunger 17 between the plunger 17 and is formed integrally. A non-magnetic material is coated or plated on the inner circumferential surface of the housing portion 14 or the outer circumferential surface of the plunger 17 in order to prevent the housing portion 14 and the plunger 17 from being in close contact with each other.

An annular concave portion 14a is formed in the outer peripheral wall of the accommodation portion 14.
The annular permanent magnet 25 shown in FIG. 2 is fitted into the concave portion 14a. As shown in FIG. 2, the permanent magnet 25 includes two ２ arc permanent magnets 25a. The magnetic flux of the permanent magnet 25 flowing through the thin portion 16 located between the permanent magnet 25 and the plunger 17 is the magnetic flux generated by the coil 20 when energizing the coil 20 is turned on (hereinafter referred to as “energizing the coil 20”). The magnetic flux generated by the coil 20 when it is turned on is referred to as a coil magnetic flux) flows in the same direction as the direction toward the thin portion 16. The thin portion 16 is magnetically saturated by the magnetic flux of the permanent magnet 25 with the power supply to the coil 20 turned off. The thickness of the thin portion 16 is set so as not to impair the mechanical strength by adjusting the magnetic force of the permanent magnet 25.

The attracting portion 15 includes an opposing portion 15a axially opposing the plunger 17, an opposing portion 15a and a permanent magnet 25.
And a tapered portion 15b that is formed on the inner peripheral wall of the suction portion 15 and that decreases in diameter toward the facing portion 15a. At the end of the plunger 17 on the suction portion 15 side, a tapered portion 17a whose diameter decreases toward the suction portion 15 is formed. The shaft 18 is press-fitted and fixed to the plunger 17 and reciprocates with the plunger 17. One end of the shaft 18 is in contact with one end of the spool 30.

The coil 20 is molded from a resin into a cylindrical shape, and is fixed by the yoke 11 and the stator core 13. When current is supplied to the coil 20 from a terminal (not shown) electrically connected to the coil 20, the yoke 11, the plunger 17, the stator core 13
The magnetic flux flows through the magnetic circuit formed by the above, and a magnetic attractive force is generated between the attractive portion 15 of the stator core 13 and the plunger 17. Then, the plunger 17 and the shaft 18 move downward in FIG. The downward movement of the plunger 17 in FIG.

The housing 31 of the spool 30 accommodates and supports the spool 30 in a reciprocating manner. The housing 31 has an input port 32, an output port 33, a feedback port 34, and a discharge port 35 formed therein. The input port 32 is a port into which hydraulic oil supplied by a pump from a tank (not shown) flows. The output port 33 is a port for supplying hydraulic oil to an engagement device of an automatic transmission (not shown). The output port 33 and the feedback port 34 communicate with each other outside the solenoid valve 1.
Part of the hydraulic 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 formed in this order from the anti-linear solenoid side. The small-diameter land 39 has a smaller outer diameter than the large-diameter lands 37 and 38. The spool 30 is always in contact with the shaft 18 of the linear solenoid 10, and the movement of the plunger 17 is transmitted via the shaft 18 to reciprocate in the housing 31. A spring 40 as a biasing means provided on the side opposite to the linear solenoid of the spool 30 biases the spool 30 toward the linear solenoid 10.

The feedback chamber 36 is formed between the large-diameter land 38 and the small-diameter land 39, and the area where the feedback hydraulic pressure acts differs depending on the outer diameter of the land. Therefore, the hydraulic pressure in the feedback chamber 36 acts to press the spool 30 in the direction opposite to the linear solenoid. The reason why a part of the hydraulic pressure output from the solenoid valve 1 is fed back is to prevent the output pressure from fluctuating due to the fluctuation in the supplied hydraulic pressure, that is, the input pressure. The spool 30 is driven by the urging force of the spring 40, the force of the plunger 17 pushing the spool 30 by the electromagnetic attraction force generated in the stator core 13 by the current supplied to the coil 20, and the hydraulic pressure of the feedback chamber 36.
It stops at a position where the force received by 0 is balanced.

The amount of hydraulic oil flowing from the input port 32 to the output port 33 is determined by the seal length, which is the length of the overlap 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 the current is supplied to the coil 20 and the spool 30 moves in the direction of the spring 40, that is, in the downward direction in FIG. 1, the seal length between the inner peripheral wall 31a and the large-diameter land 38 increases, and the inner peripheral wall 31b and the large-diameter Since the seal length with the land 37 is reduced, the output port 3
3 decreases, and the flow rate 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, when the spool 30 is
When moving in the zero direction, the seal length between the inner peripheral wall 31a and the large-diameter land 38 is shortened, and the seal length between the inner peripheral wall 31b and the large-diameter land 37 is increased. Increases, and the flow rate of hydraulic oil flowing from the output port 33 to the discharge port 35 decreases. As a result, the hydraulic pressure of the working oil flowing out of the output port 33 increases.

The solenoid valve 1 controls the value of the current supplied to the coil 20 so that the linear solenoid 10
Of the hydraulic oil flowing out of the output port 33 is adjusted. When the value of the current supplied to the coil 20 is increased, the electromagnetic attraction of the stator core 13 increases in proportion to the current value, and the force of the shaft 18 pushing the spool 30 in the direction opposite to the linear solenoid 10 increases. The plunger 17 is moved by the electromagnetic attraction force.
The spool 30 stops at a position where the force acting on the spool 30 from above, the urging force of the spring 40, and the force pushing the spool 30 toward the anti-linear solenoid 10 by the pressure of the hydraulic oil fed back are balanced. Therefore, the hydraulic pressure of the operating oil flowing out of the output port 33 decreases in proportion to the value of the current supplied to the coil 20.

Next, the operation of the solenoid valve 1 will be described. (1) When the coil is not energized When the energization of the coil 20 is turned off, the spool 30 stops at a position where the urging force of the spring 40 and the force acting by the hydraulic feedback are balanced as shown in FIG. Then, the input port 32 communicates with the output port 33 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 of the hydraulic oil supplied to the automatic transmission becomes maximum.

The magnetic flux generated by the permanent magnet 25 and flowing through the thin portion 16 flows in a thick arrow direction shown in FIG. The thin portion 16 is magnetically saturated by the magnetic flux generated by the permanent magnet 25. The direction of the magnetic flux generated by the permanent magnet 25 and flowing through the thin portion 16 is the same as the direction of the coil magnetic flux toward the thin portion 16. In other words, the permanent magnet 25 is magnetized in the direction opposite to the coil magnetic flux flowing through the housing 14.

(2) When energizing the coil When energizing the coil 20 is turned on, a magnetic flux flows as shown in FIG. 3B. As described above, since the thin portion 16 is magnetically saturated while the power to the coil 20 is turned off, the coil magnetic flux cannot flow through the thin portion 16. Therefore, the coil magnetic flux does not pass through the magnetically-saturated thin portion 16, but from the housing portion 14 to the plunger 17, from the taper portion 17 a of the plunger 17 to the taper portion 1 of the suction portion 15.
Flow toward 5b. The coil magnetic flux flowing directly from the housing portion 14 to the suction portion 15 through the thin portion 16 without passing through the plunger 17 does not act as a force for attracting the plunger 17 to the suction portion 15. By preventing the coil magnetic flux from flowing directly from the housing section 14 to the suction section 15, the force for attracting the plunger 17 increases.

FIG. 4 shows the magnitude of the attraction force depending on the presence or absence of the permanent magnet 25. It can be seen that the attraction force is larger when the permanent magnet 25 is used. Further, it can be seen that a permanent magnet having a larger residual magnetic flux density has a larger attractive force. Further, when the power to the coil 20 is turned off, the magnetic flux of the permanent magnet 25 hardly acts as a force for attracting the plunger 17.

Next, hydraulic oil discharge control and hydraulic oil output control when the coil is energized will be described. Hydraulic oil discharge control When the current supplied to the coil 20 is maximized, the electromagnetic attraction force generated between the plunger 17 and the stator core 13 is maximized, and the plunger 17 is attracted to the stator core 13 to oppose the urging force of the spring 40 and the spool. Moves with 30. Then, since 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, the pressure of the hydraulic oil supplied to the automatic transmission becomes 0 (equivalent to the atmospheric pressure).

Hydraulic oil output control When the current supplied to the coil 20 is controlled to be smaller than the state described above, the electromagnetic attraction generated between the plunger 17 and the stator core 13 decreases, and the plunger 17 and the spool 30 is the above (1) and (2)
It is located in the middle between The movement of the spool 30 causes the inner peripheral wall 31a and the large-diameter land 38 of the housing, and the inner peripheral wall 31b and the large-diameter land 37 as described above.
Since the seal length of the seal portion formed by the above changes, the pressure of the hydraulic oil supplied to the automatic transmission changes. Coil 20
By controlling the current supplied to the automatic transmission, the position of the spool 30 changes and the pressure of the hydraulic oil supplied to the automatic transmission can be adjusted.

In the first embodiment described above, the housing 14
Since the permanent magnet 25 is fitted in the concave portion 14a, the attraction force of the plunger 17 can be increased without increasing the diameter of the linear solenoid 10. Further, the annular permanent magnet 25 is formed of two １ ／ arc permanent magnets 25a to fit into the recess 14a.

(Modification) Next, a first modification of the first embodiment is shown in FIGS. 5 and 6, a second modification is shown in FIG. 7, and a third modification is shown in FIG. Modifications 1, 2, and 3 are examples in which the mounting position of the permanent magnet in the first embodiment is changed to the axial end of the stator core 52. In the first modification shown in FIG.
Reference numeral 0 denotes a yoke 51 and a stator core 52. In the stator core 52, a housing part 53 and a suction part 54 are integrally formed. A concave portion 55 is formed at an outer peripheral corner at an axial end of the stator core 52 on the side opposite to the suction portion,
An annular permanent magnet 58 is fitted into the recess 55.
A concave portion 56 is formed on the outer peripheral wall of the housing portion 53 of the stator core 52, and a thin portion 57 is formed on the inner peripheral side of the concave portion 56. As shown in FIG. 6, the magnetic flux 10 of the permanent magnet 58
0 indicates that the coil magnetic flux 101 flows in the same direction as the direction toward the thin portion 57. The thin portion 57 is magnetically saturated by the magnetic flux 100 of the permanent magnet 58 in a state where the power to the coil 20 is turned off.

In the second modification shown in FIG.
A concave portion 55 is formed at an inner peripheral corner at an axial end on the side opposite to the suction portion 2, and an annular permanent magnet 58 is formed in the concave portion 55.
Are fitted. In the third modification shown in FIG. 8, the concave portion 55
The annular permanent magnet 5 is formed in the recess 55.
8 are fitted.

As shown in FIG. 9, the first embodiment, modification 1
And the conventional example without the permanent magnet, the first
The position of the permanent magnet installed in the embodiment has the largest attractive force. Although the position of the permanent magnet of the first modification is not as large as that of the first embodiment, the attraction force is increased as compared with the conventional example. Modification 2
Also in the third modification, it is possible to obtain a suction force substantially equal to that of the first modification.

In Modifications 1, 2 and 3, a concave portion 55 is formed at the axial end of the stator core 52, and the permanent magnet 58 is fitted and attached to the concave portion 55. There is no obstruction. Therefore, the coil magnetic flux can be used for attracting the plunger 17, and
The suction force of the plunger 17 can be improved.

Further, since the permanent magnet is attached to the axial end of the stator core 52 which integrally forms the accommodating portion 53 and the suction portion 54, the permanent magnet is fitted into the concave portion 55 from one axial direction. be able to. Since it is possible to assemble a permanent magnet integrally formed in an annular shape without dividing the permanent magnet into a plurality of magnet pieces, the number of parts is reduced, the assembling becomes easy, and the processing cost of the permanent magnet can be reduced.

In Modifications 1, 2, and 3 described above,
Although the permanent magnet was fitted into the concave portion 55 formed at the axial end of the stator core 52, the thickness of the yoke on the side opposite to the attracting portion was increased, and the permanent magnet was fitted into the concave portion provided on the yoke. The permanent magnet may be sandwiched between the end portions in the axial direction.

(Second Embodiment) FIG. 1 shows a second embodiment of the present invention.
0 is shown. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals. The stator 60 includes the yoke 11, the stator core 61, and the end yoke 65. The yoke 11, the stator core 61 and the end yoke 65 form a magnetic circuit with the plunger 17. The accommodation portion 62 of the stator core 61 is thinned, and a cylindrical end yoke 65 is provided on the outer periphery of the accommodation portion 62. The end yoke 65 and the suction portion 6
3 and a permanent magnet 70 is sandwiched therebetween. Permanent magnet 7
0 is integrally formed in a ring shape.

The magnetic flux generated by the permanent magnet 70 flows in the same direction as the coil magnetic flux flowing through the thin-walled housing 62.
When the power to the coil 20 is turned off, the housing portion 62 located on the inner peripheral side of the permanent magnet 70 is magnetically saturated. Therefore, the coil magnetic flux does not flow through the housing portion 62 on the inner circumference side of the permanent magnet 70, and the housing portion 62, the plunger 17, and the plunger 17 located on the inner circumference side of the end yoke 65 from the end yoke 65.
From the tapered portion 17a of the suction portion 63. The plunger 17 is attracted downward in FIG. 10 by the flow of the coil magnetic flux. In the second embodiment, since the permanent magnet 70 is sandwiched between the suction portion 63 of the stator core 61 and the end yoke 65, the permanent magnet 70 integrally formed in an annular shape can be assembled.

(Third Embodiment) FIG. 1 shows a third embodiment of the present invention.
1 and FIG. Components that are substantially the same as those of the first modification of the first embodiment are given the same reference numerals. The permanent magnet 80 fitted in the concave portion 56 formed on the outer peripheral wall of the housing portion 53
Is formed in an annular shape. Attraction part 5 of permanent magnet 80
An annular notch 81 is formed in the inner corner on the fourth side. Next, the effect of the third embodiment will be described in comparison with a comparative example shown in FIG. 14 in which a permanent magnet is fitted in the recess 56 in the first modification.

The fact that the direction in which the coil magnetic flux flows through the thin portion 57 is the same as the direction in which the magnetic flux generated by the permanent magnet 80 flows through the thin portion 57 means that the coil magnetic flux flows between the plunger 17 and the suction portion 54. And the direction of the magnetic flux flowing inside the permanent magnet 80, that is, the direction of the permanent magnet 5
8 is opposite to the magnetization direction. Therefore, when the permanent magnet 58 which does not cut off the inner peripheral side corner of the suction part 54 is fitted in the concave part 56 as in the comparative example, the magnetic flux flowing between the plunger 17 and the suction part 54 is It passes through the inner corner of the permanent magnet 58 on the suction part side. At a high temperature, when the coil magnetic flux in the direction opposite to the magnetization direction passes through the permanent magnet, the portion where the coil magnetic flux has passed is demagnetized. As shown in FIG. 16, when the inner peripheral side corner of the attraction portion of the permanent magnet 58 is demagnetized, the plunger attractive force indicated by the solid line 202 generated in the initial stage of use of the permanent magnet 58 is indicated by a dotted line 203. The plunger suction force changes. If the plunger suction force changes in this way, the amount of displacement of the plunger 17 cannot be controlled with high accuracy.

On the other hand, in the third embodiment, the permanent magnet 80
13 is cut off at the inner peripheral side corner on the suction part side of FIG.
As shown in (1), the coil magnetic flux does not pass through the permanent magnet 80, and the inner peripheral side corner of the permanent magnet 80 on the suction portion side does not demagnetize. Therefore, as can be seen from the characteristic curves of the initial stage of use shown by the solid line 200 in FIG. Can be controlled.

Even if the flow direction of the coil magnetic flux and the magnetizing direction of the permanent magnet are opposite to those in the third embodiment, the position where the permanent magnet is to pass is the inner peripheral corner on the side of the attracting portion. Therefore, even when the flow direction of the magnetic flux is reversed, the position where the notch is formed is the inner peripheral side corner on the attracting portion side of the permanent magnet.

(Fourth Embodiment) In a fourth embodiment shown in FIG. 17, notches 86 are formed at both inner corners of the permanent magnet 85. In this case, since the permanent magnet 85 may be oriented to either side in the axial direction at the time of assembly, the assembly of the permanent magnet 85 is easy.

In the above-described plural embodiments showing the embodiment of the present invention, since the stator accommodating portion and the suction portion are formed integrally, the plunger 17 and the stator are formed in the radial direction. The air gap to be formed can be made as small as possible. Further, a permanent magnet that generates magnetic flux in the housing in the same direction as the direction in which the coil magnetic flux flows through the housing is disposed in the housing. And by the physique of the electromagnetic drive,
That is, the attraction force of the plunger can be increased without increasing the size of the solenoid valve.

In the above embodiment, the electromagnetic drive unit of the present invention was used for the electromagnetic drive unit of the spool type hydraulic control valve. In addition to this, the electromagnetic drive device of the present invention may be used as a drive device for any electromagnetic valve or device as long as the attraction force of the mover is increased without increasing the physical size.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a solenoid valve according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a permanent magnet of the first embodiment.

FIG. 3A is a schematic explanatory diagram illustrating a magnetic flux flow when energization of a coil is turned off, and FIG. 3B is a schematic explanatory diagram illustrating a magnetic flux flow when energization of a coil is turned on.

FIG. 4 is a characteristic diagram for comparing the presence / absence of a permanent magnet and the magnitude of an attractive force in the solenoid valve of the first embodiment.

FIG. 5 is a cross-sectional view illustrating an electromagnetic drive device according to a first modification of the first embodiment.

FIG. 6 is a cross-sectional view illustrating a magnetic flux flow according to a first modification.

FIG. 7 is a cross-sectional view illustrating an electromagnetic drive device according to a second modification of the first embodiment.

FIG. 8 is a sectional view showing an electromagnetic drive device according to a third modification of the first embodiment.

FIG. 9 is a characteristic diagram comparing suction powers of the first embodiment, the first modification, and the conventional example.

FIG. 10 is a sectional view showing a solenoid valve according to a second embodiment of the present invention.

FIG. 11 is a sectional view showing an electromagnetic driving device according to a third embodiment of the present invention.

FIG. 12 is a sectional view showing a permanent magnet according to a third embodiment.

FIG. 13 is a schematic explanatory view showing a magnetic flux flow when energization of a coil is turned on in the third embodiment.

FIG. 14 is a schematic explanatory view showing a magnetic flux flow when energization of a coil is turned on in a comparative example of the third embodiment.

FIG. 15 is a characteristic diagram showing a plunger suction force in the third embodiment.

FIG. 16 is a characteristic diagram showing plunger suction force in a comparative example.

FIG. 17 is a sectional view showing a permanent magnet according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 10 Linear solenoid (electromagnetic drive) 11 Yoke (stator) 13 Stator core (stator) 17 Plunger (movable member) 30 Spool (movable member) 40 Spring (biasing member) 50, 60 Stator 51 Yoke ( Stator) 52, 61 Stator core (stator) 53, 62 Housing part 54, 63 Suction part 56 Depression 57 Thin part 58, 70 Permanent magnet 65 End yoke (stator) 80, 85 Permanent magnet 81, 86 Notch

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroyuki Nakane 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Seiji Tachibana 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation (72) Inventor Tetsuya Aoki 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3H106 DA02 DA23 DB02 DB12 DB23 DB32 DD09 EE34 EE35 GA13 KK17 5E048 AA08 AB01 AC05 AC06 AD02

Claims (10)

[Claims] A movable member, a housing portion for reciprocally accommodating the movable member, and a suction portion in which a magnetic force for attracting the movable member in one direction of the reciprocating movement acts between the movable member. And a stator that forms a magnetic circuit with the mover, a coil that generates a magnetic force to attract the mover to the suction unit side by energizing, and a magnetic flux that is generated by energizing the coil. And a permanent magnet that generates a magnetic flux flowing through the housing in the same direction. 2. The electromagnetic drive device according to claim 1, wherein the permanent magnet is attached to the housing portion radially facing the mover. 3. The electromagnetic drive device according to claim 2, wherein the housing has a concave portion on the outer peripheral wall for fitting the permanent magnet. 4. The electromagnetic drive device according to claim 3, wherein a notch is formed in an inner peripheral side corner of the permanent magnet on the side of the attraction portion. 5. The electromagnetic driving device according to claim 4, wherein notches are formed at both inner corners of the permanent magnet. 6. The electromagnetic drive device according to claim 1, wherein the permanent magnet is attached to an axial end of a portion where the housing portion and the suction portion of the stator are integrally formed. 7. The electromagnetic driving device according to claim 2, wherein the permanent magnet is formed in an annular shape. 8. When the energization of the coil is turned off, a part of the housing portion radially opposed to the mover includes:
The electromagnetic drive device according to any one of claims 2 to 7, wherein the magnetic drive is magnetically saturated by the magnetic flux of the permanent magnet flowing in the housing in the same direction as the magnetic flux generated by energizing the coil. . 9. A housing having a plurality of fluid flow paths penetrating a cylindrical peripheral wall, the electromagnetic drive device according to claim 1, and the fluid by reciprocating with the movable element. An electromagnetic valve, comprising: a movable member that switches communication of a flow path; and a biasing unit that biases the movable member in a direction opposite to a direction in which the movable element is attracted to the suction unit. 10. The solenoid valve according to claim 9, wherein the output hydraulic pressure is controlled.