JP2000213664A - Electromagnetic working device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a movable member from making contact with an iron core part of a yoke as a disc spring supporting the movable member of an electromagnetic working device is deformed. SOLUTION: A movable member 15 fastened at a central part of a disc spring 30 with an outer peripheral side part fastened on a yoke 12 and supported free to move in the axial direction with a small clearance between itself and an inner peripheral surface of an iron core part 12a of the yoke is attracted and stroked in the axial direction by applying an applied electric current to an electromagnetic coil 13. The movable member 15 is made contact with a member fixed on the yoke by deflecting the disc spring 30 in a state where attraction force is zero when it is pressurized in the reverse direction of the attraction force, and it comes to be in the maximum stroke state as deflection of the disc spring 30 is almost eliminated in a state where attraction force is the maximum. The disc spring can be devised to release fastening of the outer peripheral part against the yoke in the neighbourhood of a stress concentrated part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic actuator used for operating an electromagnetic valve or the like, and more particularly to an electromagnetic actuator in which a movable member moved by an electromagnetic force is supported by a disk spring.

[0002]

2. Description of the Related Art As an electromagnetic valve using this type of electromagnetic actuator, there is, for example, one shown in FIG. The solenoid valve includes a magnetic drive unit 10 as an electromagnetic actuator and a valve unit 20.
The magnetic drive unit 10 comprises a core 11 and a yoke 12 which are coaxially integrated, an electromagnetic coil 13 provided coaxially therebetween, and a disk spring whose outer peripheral portion is fixed to the yoke 12. 1 and the tip 1 in the center
A plunger (movable member) supported to be movable in the axial direction with a slight gap between the inner peripheral surface of a cylindrical iron core 12a formed at the center of the yoke 12 and having the 5a fixed thereto.
15 is a main member. Outer peripheral portion 12 of yoke 12
"b" forms a cylindrical case, and a thin caulked portion 12c is formed at one end thereof. The caulking portion 12c is initially opened in a cylindrical shape as shown by a two-dot chain line, into which the disk spring 1 and the outer peripheral portion of the cover plate 7 are inserted in an overlapping manner and bent and caulked as shown by the solid line. As a result, the entire circumference of the outer peripheral portion of the disk spring 1 (see the hatched portion 4 in FIG. 11) is
1 and a flange 7a around the cover plate 7 (FIG. 1).
0) is fixed.

The tapered portion on the inner end side of the plunger 15 is located near the gap formed between the respective distal ends of the opposed cylindrical iron core portions 11a and 12a at the center of the yoke 11 and the stator 12. A rod 16 is coaxially fixed to the inner end of the plunger 15 by press-fitting or the like. The rod 16 is slidably supported by a bush 14 press-fitted and fixed to the inner surface of the core 11 and faces toward the valve section 20. It is protruding. The valve sleeve 21 of the valve portion 20 has a flange portion at one end overlapped on the outside of the yoke 11 and inserted into a thin cylindrical caulking portion 12d and caulked and fixed to the yoke 12 coaxially. , A spool 22 is slidably fitted. The spool 22 is pressed against the tip of the rod 16 by a spring 24 interposed between the spool 22 and a spring receiver 23 screwed into the tip of the valve sleeve 21, and thereby is moved together with the plunger 15.

As shown in FIG. 11, the disk spring 1 is a thin plate made of a disc-shaped spring material as a whole, and is almost flat in a free state. The yoke 12 is formed so that the spring constant becomes appropriate softness. The outer peripheral portion and the central portion, which are fixed by caulking, are connected by three spiral arm portions 3, and between each arm portion 3, an elongated punched hole 3a is formed. The plunger 15 is supported by the disc spring 1 by inserting the tip 15a into the hole 2 at the center of the disc spring 1 and caulking with the washer 17 to prevent the plunger 15 from coming off.

When no control current is applied to the electromagnetic coil 13, the cores 11 a, 12
Since a is not magnetized, the axial suction force P acting on the plunger 15 is 0, and the plunger 15 gives a slight initial deflection to the substantially flat disk spring 1 in the free state, and the tip 15a It is stopped by contacting the cover plate 7 (see the state of the minimum stroke state shown in the upper half of FIG. 9). As the control current applied to the electromagnetic coil 13 increases and the magnetization of the iron cores 11a and 12a increases, the axial attractive force P acting on the plunger 15 increases, whereby the plunger 15 moves the spring 24 and the disc spring 1 When the control current reaches a predetermined value, the stopper 16a fixed to the rod 16 contacts the core 11 and the plunger 1
5 is stopped (see the maximum stroke state shown in the lower half of FIG. 9). By the movement of the plunger 15, the valve section 20 is operated via the rod 16.

[0006]

In the above-described solenoid valve, the core 11 and the yoke 1 are controlled by an applied control current.
When the second iron cores 11a and 12a are magnetized, not only the suction force P in the axial direction but also the suction force Q in the horizontal direction acts on the plunger 15 due to misalignment due to an error in processing or assembly. Due to the suction forces P and Q, the disk spring 1 exerts a stress on a stress concentration portion (cross hatching portion) 5 adjacent to the outer peripheral side of the disk spring 1 among the ends of the three punched holes 3a. Concentration occurs, and in particular, stress concentration occurring in the cross hatching portion 5 near the opposite side of the suction force Q increases (see FIG. 11).

As described above, since the stress generated in the disk spring 1 is not uniform, in the following, the largest one of the stresses generated in the disk spring 1 in a certain operating state (attraction force in the examples shown in FIGS. 9 to 11). (Stress generated in the stress concentration portion 5 near the opposite side of Q, hereinafter simply referred to as stress) will be examined. As shown in FIG. 12, this stress is a sum σc + σd of the stress σc due to the axial deflection from the free state of the disc spring 1 and the stress σd due to the lateral suction force Q. The above-described conventional magnetic drive unit 1
0 indicates that the control current is 0 and the stroke of the plunger 15 is 0.
In the state (1) (minimum stroke state), the axial deflection of the disk spring 1 is only a slight initial deflection, and the lateral suction force Q is 0. Therefore, the stress of the disk spring 1 is the stress σc due to the initial deflection. It is only the minimum value σc0. As the control current increases, the magnetization of the core 11 and the yoke 12 increases, and the stress σc and the stress σd increase as the plunger 15 strokes. When the stroke end E, ie, the maximum stroke state, is reached, the stress σc and the stress σd Becomes the maximum value σcm and the maximum value σdm, respectively.
The stress generated in the disc spring 1 is the maximum value σcm + σdm
Becomes

The maximum value .sigma.cm of the stress .sigma.c due to the axial deflection of the disc spring 1 is almost constant, but the maximum value .sigma.dm of the stress .sigma.d due to the lateral suction force Q differs depending on the direction and degree of misalignment of the plunger 15. And the sum of the maximum values of the two stresses, σcm + σdm, is, as shown in FIG.
In some cases, the proof stress σy of the spring material that is the material of the disc spring 1 may be exceeded. In such a case, the magnetic drive unit 1
As the operation is repeated, the plastic deformation of the portion where such stress is generated gradually accumulates and the local permanent deformation increases in the disc spring 1, so that the plunger 15 comes into contact with the inner surface of the core 12 a of the yoke 12. Therefore, there is a problem that the operation characteristics of the magnetic drive unit 10 are deviated. An object of the present invention is to solve such a problem by reducing the maximum stress generated in the disc spring 1.

[0009]

According to a first aspect of the present invention, there is provided an electromagnetic actuator comprising: a yoke having a cylindrical iron core formed at a central portion; a disk spring having an outer peripheral portion fixed to the yoke; A movable member fixed to the center of the spring, supported coaxially with the core of the yoke and supported so as to be axially movable with a slight gap between the inner peripheral surface of the core and the core of the yoke; An electromagnetic actuating device comprising an electromagnetic coil provided between the armature and the outer peripheral portion to excite the iron core portion in response to an applied control current and apply an attractive force to the movable member to cause the movable member to stroke in the axial direction. At
The movable member is pressed in a direction opposite to the suction force, and when the suction force is zero, the disk spring is bent to make the movable member a minimum stroke state, and when the suction force is maximum, the disk spring is hardly bent. A spring for bringing the movable member into a maximum stroke state.

In the first aspect of the invention, as the movable member moves from the minimum stroke state to the maximum stroke state in accordance with the increase in the magnetization of the iron core of the yoke, the axial deflection from the free state of the disk spring is reduced by the minimum stroke. The stress in the disk spring due to this axial deflection decreases from the maximum value in the maximum stroke state to the minimum value in the maximum stroke state. On the other hand, the stress generated in the disk spring due to the increase in the lateral suction force changes from the minimum value (= 0) in the minimum stroke state to the maximum value in the maximum stroke state. Since the maximum value of the stress due to the lateral suction force is smaller than the maximum value of the stress due to the axial deflection, the maximum value of the stress generated in the disk spring by the axial deflection and the suction force is the stress due to the axial deflection generated in the minimum stroke state. And the minimum value of the stress due to the lateral suction force. That is, the maximum stress generated in the disk spring does not become the sum of the maximum value of the stress due to the axial deflection from the free state and the maximum value of the stress due to the lateral suction force as in the above-described prior art. It will be much smaller than.

[0011] A second aspect of the present invention is an electromagnetic actuator.
A yoke having a cylindrical core in the center thereof, a disk spring having an outer peripheral portion fixed to the yoke, and a coaxial and the same core as the core of the yoke fixed to the center of the disk spring. A movable member which is supported so as to be movable in the axial direction with a slight gap between the inner peripheral surface and the inner peripheral surface of the yoke according to a control current applied between an iron core portion and an outer peripheral portion of the yoke. In an electromagnetic actuator comprising an electromagnetic coil that excites and applies an attractive force to the movable member to cause the movable member to stroke in the axial direction, the disk spring is located near a stress concentration portion where stress concentration occurs due to a force applied from the movable member. Is characterized in that the fixing of the outer peripheral portion to the yoke is released.

In the second aspect of the invention, the maximum stress generated in the disk spring is generated in the stress concentration portion where the stress concentration occurs, and the maximum value of the stress due to the axial suction force and the stress due to the lateral suction force are usually the same as in the prior art. Is the sum of the maximum values of However, according to the second aspect, in the vicinity of the stress concentration portion, the fixation of the outer peripheral portion to the yoke is released so that the stress is dispersed over a wide range. Becomes smaller.

According to the second aspect of the invention, the outer peripheral flange of the cover plate covering the end surface of the yoke is caulked and fixed to the outer peripheral end surface, and the disk spring has its outer peripheral portion joined to the outer peripheral end surface of the yoke. The cover plate is sandwiched and fixed between the flanges, and a notch is formed in the flange of the cover plate near the stress concentration part, a notch is formed in the outer periphery of the disc spring, or in the vicinity of the stress concentration part. It is preferable to perform caulking for fixing the flange portion at a position other than. If you do this,
The release of the outer peripheral portion of the disk spring from the yoke near the stress concentration portion can be released very easily.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electromagnetic actuator according to the present invention. First, Figure 1
The first embodiment will be described with reference to FIG. The electromagnetic actuator according to the first embodiment is a magnetic drive unit 10 that operates a valve unit 20, as in the above-described related art. This magnetic drive unit 10 is different from the conventional magnetic drive unit 10 shown in FIGS. 9 to 12 only in the setting of the axial deflection of the disk spring 30 during assembly, and there is no particular difference in other points. This difference will be mainly described.

As shown in FIG. 3, the disk spring 30 according to the first embodiment is a thin plate made of a disc-shaped spring material, is substantially flat in a free state, and is caulked and fixed to the yoke 12. The outer peripheral portion and the central portion are connected by three spiral arm portions 32, and an elongated punched hole 32 a is formed between each arm portion 32. This disc spring 30 is substantially the same as the prior art disc spring 1 shown in FIG. However, unlike the above-described prior art, the disk spring 30 of the first embodiment has a maximum axial deflection from the free state in the minimum stroke state and a slight initial axial deflection in the maximum stroke state. It is set as follows. That is, the plunger (movable member) 15 fixed by caulking to the center of the disc spring 30 is in a state where external force such as a suction force P magnetized by the electromagnetic coil 13 by the core 11 and the yoke 12 and a spring force by the spring 24 is not applied. Is the stopper 1 of the rod 16
6a is in contact with the core 11a of the core 11 and is held in the maximum stroke state.

In this state, the spring 24 is
If the spring receiver 23 is screwed in contact with the tip of 2,
The spring force of the spring 24 moves the plunger 15 via the spool 22 and the rod 16 to the core 11 and the yoke 12.
Is pressed in the opposite direction to the suction force P when magnetized, and the spring receiver 23 is screwed to a normal position.
Plunger 1 by flexing disc spring 30 to the maximum
5 is in a minimum stroke state in which the distal end portion 15a is brought into contact with a cover plate 37 fixed by caulking to the yoke 12.

That is, in the first embodiment, when the control current is not applied to the electromagnetic coil 13, the disk spring 30 is pressed by the spring 24 and the axial deflection from the free state is maximized, and the plunger 15 Is stopped when its tip 15a contacts the cover plate 7 (see the minimum stroke state shown in the upper half of FIG. 1). When a control current is applied to the electromagnetic coil 13, the magnetization of the core portions 11 a and 12 a of the core 11 and the yoke 12 increases due to the increase in the control current, and the axial attraction P acting on the plunger 15 increases accordingly. As a result, the plunger 15 strokes against the urging force of the spring 24, the axial deflection of the disc spring 30 decreases, and when the control current reaches a predetermined value, the rod 16
The plunger 15 is stopped by the contact of the stopper 16a fixed to the core 11 with the stopper 16a (see the maximum stroke state shown in the lower half of FIG. 9). In this state, the axial deflection of the disc spring 30 is minimized (initial deflection). In these states, as described in the related art, the disk spring 30 has a stress concentration portion (cross hatching portion) adjacent to the outer peripheral side of the disk spring 30 among the ends of the three punched holes 32a. ) 34, and the stress concentration particularly in the cross hatching portion 34 near the opposite side of the suction force Q increases (see FIG. 11).

In the following, the largest stress generated in the disc spring 30 in a certain operating state (stress generated in the stress concentration portion 34 near the opposite side of the suction force Q, hereinafter simply referred to as stress) will be examined. As shown in FIG. 4, this stress is a sum σ of stress σa due to axial deflection from a free state and stress σb due to lateral suction force Q.
a + σb. The magnetic drive unit 1 according to the first embodiment
At 0, when the control current is 0 and in the minimum stroke state, the axial deflection of the disk spring 30 is maximum and the lateral suction force Q is 0, so the stress of the disk spring 30 is due to the axial deflection. It is only the maximum value σam of the stress σa (= the maximum value σcm of the prior art described above).
As the control current increases, the magnetization of the core 11 and the yoke 12 increases, and as the plunger 15 strokes, the stress σa
When the stroke end E, that is, the maximum stroke state, is reached, the stress σa and the stress σb are respectively reduced to the minimum value σa0 and the maximum value σbm (= the minimum value σc0 and the maximum value σdm of the prior art described above, respectively). ), And the stress generated in the cross hatching portion 34 is the sum σa0 +
σbm.

In such a disk spring 30,
Normally, the maximum value σam of the stress σa is larger than the maximum value σb of the stress σb.
bm, and the minimum value σa0 of the stress σa is much smaller than these maximum values, so that the cross hatching portion 34 of the disc spring 30 in the minimum stroke state.
Is the maximum value σam (see FIG. 4). The maximum value σam of the stress is the maximum value σcm + σ of the stress generated in the stress concentrating portion 5 in the maximum stroke state of the prior art described above.
It becomes considerably smaller than dm (= σam + σbm), and does not exceed the proof stress σy of the disc spring 30. As a result, even if the operation of the magnetic drive unit 10 is repeated, plastic deformation is partially accumulated in the disk spring 30 and permanent deformation does not occur. Therefore, the plunger 15 contacts the inner surface of the core 12a of the yoke 12. As a result, the operation characteristics of the magnetic drive unit 10 are not deviated.

Next, a second embodiment will be described with reference to FIGS. The electromagnetic actuator according to the second embodiment is also a magnetic drive unit 10 that operates the valve unit 20, as in the above-described related art. The magnetic drive unit 10 includes the yoke 1
2 is crimped to one end of the outer peripheral portion 12b.
The cover plate 37A for sandwiching and fixing the outer peripheral portion of the disk spring 30A between the end plate 2b and the end surface of the cover plate 2A is different from the above-described cover plate 7 of the prior art, and the other points are not particularly different. Will be described.

The cover plate 3 of the second embodiment
7A is a disk spring 30A as shown in FIG.
Three notches 39 are formed at equal angular intervals in an outer peripheral flange portion 38B which is a portion for clamping and fixing an outer peripheral portion of the outer peripheral portion. The cover plate 37 is formed such that each notch 39 has a stress concentration portion of the disc spring 30A (similar to that described in the related art and the first embodiment), outside of the disc spring 30A among the ends of the three punched holes 32a. The cross-hatching portion 34A adjacent to the peripheral portion side) 34A is overlapped with the disk spring 30A so as to be located at a position corresponding to 34A, and inserted into a thin cylindrical caulking portion 12c formed at one end of the yoke 12, It is fixed by bending and caulking as shown by the solid line. Therefore, the disk spring 30
Only the hatching portion 33A (see FIG. 6) is fixed to the yoke 12 at the outer peripheral portion of A, and the fixing of the outer peripheral portion to the yoke 12 is released near the stress concentration portion 34A.

In the second embodiment, the maximum value of the stress generated in the stress concentration portion 34A of the disk spring 30A is normally σam + σbm, as in the above-described prior art.
(= Σcm + σdm). However, in the second embodiment, since the outer peripheral portion is not fixed to the yoke 12 in the vicinity of the stress concentration portion 34A, the stress is dispersed over a wide range in the stress concentration portion 34A, and the degree of stress concentration is reduced. Σam and σbm have lower values of themselves. As a result, the maximum value of the stress generated in the stress concentration portion 34A becomes smaller, so that it becomes considerably smaller than the maximum value σcm + σdm of the stress generated in the stress concentration portion 5 in the above-described conventional maximum stroke state, and does not exceed the proof stress σy. . As a result, even if the operation of the magnetic drive unit 10 is repeated, plastic deformation is partially accumulated in the disk spring 30 and permanent deformation does not occur. Therefore, the plunger 15 contacts the inner surface of the core 12a of the yoke 12. As a result, the operation characteristics of the magnetic drive unit 10 are not deviated.

Next, a third embodiment will be described with reference to FIGS. The electromagnetic actuator according to the third embodiment is also a magnetic drive unit 10 that operates the valve unit 20, similarly to the above-described related art and the second embodiment. The magnetic drive unit 10 differs from the above-described prior art disk spring 1 in that the outer peripheral portion of a disk spring 30B sandwiched and fixed between one end of an outer peripheral portion 12b of a yoke 12 and a cover plate 37B crimped thereon. Since there is no difference in the other points, the difference will be mainly described.

As shown in FIG. 8, the disk spring 30B according to the third embodiment includes one end of the yoke 12 and a cover plate 37B which is caulked to the one end.
Three notches 35 are formed at equal angular intervals in an outer peripheral portion which is a portion to be sandwiched and fixed between the disk springs 30B, except that the notch 35 is fixed to the yoke 12 in the outer peripheral portion of the disc spring 30B. Only the hatching part 33B (see FIG. 8) is provided. This notch 35 is adjacent to the stress concentrated portion of the disk spring 30B (similar to the second embodiment, the end of the three punched holes 32a which is closer to the outer peripheral side of the disk spring 30B). Cross hatching part) 34
Since it is formed near B, the fixation of the outer peripheral portion to the yoke 12 is released near the stress concentration portion 34B.

Also in the third embodiment, the maximum value of the stress generated in the stress concentration portion 34B of the disk spring 30B is σam + σbm (= σcm + σdm) as described above. However, also in the third embodiment, since the fixation of the outer peripheral portion to the yoke 12 is released near the stress concentration portion 34B, the stress is dispersed over a wide range in the stress concentration portion 34B, and the degree of stress concentration is reduced. Σam and σbm have lower values of themselves. As a result, the maximum value of the stress generated in the stress concentration portion 34B becomes smaller, so that it becomes considerably smaller than the maximum value σcm + σdm of the stress generated in the stress concentration portion 5 in the above-described conventional maximum stroke state, and does not exceed the proof stress σy. . As a result, permanent deformation does not occur, and the plunger 15 comes into contact with the inner surface of the iron core portion 12a of the yoke 12 and
The operating characteristics of 0 are not disturbed.

Although not shown in the drawings, the present invention relates to FIGS.
In the prior art shown in FIG. 11, the outer peripheral portions of the disk spring 1 and the cover plate 7 by bending the caulking portion 12c of the yoke 12 are performed at positions other than the position corresponding to the vicinity of the stress concentration portion 5. Is also good. Even in this case, the fixation of the outer peripheral portion to the yoke 12 near the stress concentration portion 5 is released.
In the stress concentration portion 5, the stress is dispersed over a wide range and the degree of stress concentration is reduced, thereby reducing the maximum value of the stress generated in the stress concentration portion 34B. It becomes considerably smaller than the maximum value of the generated stress σcm + σdm, and does not exceed the proof stress σy. Accordingly, permanent deformation does not occur in the disk spring 1 and the plunger 15 does not come into contact with the inner surface of the iron core portion 12a of the yoke 12, thereby preventing the operating characteristics of the magnetic drive unit 10 from being changed.

The present invention also relates to a first embodiment in which the stress is reduced by changing the setting of the axial deflection of the disk spring during assembly, and to reduce the stress of the disk spring by reducing the degree of stress concentration. The present invention can be implemented in combination with other embodiments. In this case, the effect of reducing the stress of the disk spring is the sum of the effects of the respective embodiments, so that a greater effect can be obtained.

[0028]

According to the first aspect of the present invention, the maximum stress generated in the disk spring is considerably smaller than that of the prior art, and it is possible not to exceed the proof stress. Even if repeated, plastic deformation is partially accumulated in the disk spring and permanent deformation does not occur, so that the movable member comes into contact with the inner surface of the yoke iron core and the operating characteristics of the magnetic drive unit are disordered. Is gone.

According to the second invention, the degree of stress concentration at the stress concentration portion is reduced, and the maximum value of the stress caused by the stress concentration is reduced. Therefore, similar to the first invention,
The movable member does not come into contact with the inner surface of the iron core portion of the yoke, so that the operating characteristics of the magnetic drive unit do not deteriorate.

In the second aspect of the present invention, the outer peripheral portion of the disk spring is sandwiched and fixed between the end surface of the outer peripheral portion of the yoke and the flange portion of the cover plate. According to the notch, the notch provided on the outer periphery of the disk spring, or the caulking performed at a position other than the vicinity of the stress concentration portion, the degree of stress concentration at the stress concentration portion is extremely easily determined. And the maximum value of the generated stress can be reduced, so that the movable member and the yoke do not come into contact with each other, so that the operating characteristics of the magnetic drive unit do not deteriorate.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entire structure of an electromagnetic valve including a first embodiment of an electromagnetic actuator according to the present invention.

FIG. 2 is a front view of the cover plate of the embodiment shown in FIG.

FIG. 3 is a front view of the disk spring of the embodiment shown in FIG.

FIG. 4 is a view for explaining a change state of a stress of a disk spring with respect to a stroke of a movable member in the embodiment shown in FIG. 1;

FIG. 5 is a front view of a cover plate in a second embodiment of the electromagnetic actuator according to the present invention.

FIG. 6 is a front view of a disk spring in a second embodiment of the electromagnetic actuator according to the present invention.

FIG. 7 is a front view of a cover plate in a third embodiment of the electromagnetic actuator according to the present invention.

FIG. 8 is a front view of a disk spring in a third embodiment of the electromagnetic actuator according to the present invention.

FIG. 9 is a longitudinal sectional view showing the entire structure of an electromagnetic valve including an example of an electromagnetic actuator according to a conventional technique.

FIG. 10 is a front view of the prior art cover plate shown in FIG.

FIG. 11 is a front view of the conventional disk spring shown in FIG. 9;

12 is an explanatory diagram similar to FIG. 4 in the prior art shown in FIG. 9;

[Description of Signs] 12 ... yoke, 12 a ... iron core part, 12 b ... outer peripheral part, 13
... Electromagnetic coil, 15 ... Movable member (plunger), 24 ...
Spring, 30, 30A, 30B: disk spring, 32: arm, 32a: punched hole, 34, 34A, 3
4B: stress concentration portion, 35: notch, 37, 37A. 37
B: Cover plate, 38, 38A, 38B: Flange, 39: Notch.

Claims (6)

[Claims] A yoke having a cylindrical core portion formed at a central portion thereof; a disk spring having an outer peripheral portion fixed to the yoke; and a disk spring fixed to a central portion of the disk spring and coaxial with the iron core portion of the yoke. And a control member provided between the core portion and the outer peripheral portion of the yoke, the movable member being supported movably in the axial direction with a slight gap between the core portion and the inner peripheral surface of the same. An electromagnetic actuator, comprising: an electromagnetic coil that excites the iron core portion in response to an electric current and causes an attractive force to act on the movable member to cause the movable member to stroke in the axial direction. When the suction force is zero, the disk spring is bent to bring the movable member into the minimum stroke state, and when the suction force is maximum, the disk spring is almost deflected. An electromagnetic actuator, comprising: a spring for moving the movable member to a maximum stroke state. 2. A yoke having a cylindrical core in the center thereof, a disk spring having an outer peripheral portion fixed to the yoke, and a disk spring fixed to the center of the disk spring and coaxial with the iron core of the yoke. And a control member provided between the core portion and the outer peripheral portion of the yoke, the movable member being supported movably in the axial direction with a slight gap between the core portion and the inner peripheral surface of the same. An electromagnetic actuator, comprising: an electromagnetic coil that excites the iron core portion in response to an electric current and applies an attractive force to the movable member to cause the movable member to stroke in the axial direction, wherein the disc spring is a force applied from the movable member. An electromagnetic actuator in which the outer peripheral portion is released from being fixed to the yoke in the vicinity of a stress concentration portion where stress concentration occurs due to the following reason. 3. A cover plate for covering the end surface of the yoke, to which the disk spring is fixed, is fixed by caulking an outer peripheral flange portion to an end surface of an outer peripheral portion of the yoke, and the disk spring is fixed to an outer peripheral portion thereof. Wherein the cover plate is sandwiched and fixed between an end surface of an outer peripheral portion of the yoke and a flange portion of the cover plate, and a notch is provided in the flange portion of the cover plate at a position corresponding to the vicinity of the stress concentration portion. 3. The electromagnetic actuator according to 2. 4. A cover plate for covering an end surface of the yoke, which is a side to which the disk spring is fixed, by caulking an outer peripheral flange portion to an end surface of an outer peripheral portion of the yoke, and fixing the disk spring to an outer peripheral portion thereof. 3. The disk spring according to claim 2, wherein a notch is provided between the end surface of the outer peripheral portion of the yoke and the flange portion of the cover plate, and a notch is provided in the outer peripheral portion of the disk spring near the stress concentration portion. An electromagnetic actuator as described. 5. A cover plate for covering an end surface of the yoke on a side to which the disk spring is fixed, the outer peripheral flange portion of which is fixed by caulking an outer peripheral end surface of the yoke. The portion is sandwiched and fixed between an end surface of an outer peripheral portion of the yoke and a flange portion of the cover plate, and the caulking is performed at a position except a position corresponding to the vicinity of the stress concentration portion. An electromagnetic actuator as described. 6. An outer peripheral portion and a central portion of the disk spring are connected by a plurality of spiral arms, and an elongated punched hole is formed between the arms, and the stress concentration portion is formed by the punched hole. The electromagnetic actuator according to any one of claims 2 to 5, wherein the end portion is a portion adjacent to the outer peripheral side of the disk spring.