JP2003163115A - Electromagnetic actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic actuator which can always equally continuously operate, having a simple structure, even when a failure such as breaking of a coil happens or in an emergency. <P>SOLUTION: When a current flows to a coil, a plurality of solenoids each having a plunger and a shaft rotating or reciprocating are aligned on the same straight line, and a shaft of at least one solenoid among the plurality of solenoids is not fixed to the plunger so as to be independently movable. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an electromagnetic actuator and a driving method.

[0002]

2. Description of the Related Art A conventional electromagnetic actuator is shown in FIG. FIG. 3 is a vertical sectional view of a conventional solenoid. In the figure, 1 is a frame, 2 is a plunger, 3 is a base, 4 is a stator, 5 is a bobbin, 6 is a coil, 7 is a shaft, 8 is a plunger spring, 9 is an air gap spacer, 10 and 10 'are bearings, 11 is Sleeves 12 and 12 'are leads.

The frame 1 is made of a magnetic material and has a hole 1a at the bottom. The plunger 2 is processed into a shape with a protruding tip (hereinafter referred to as a leakage type), so that the suction force at a desired stroke becomes strong. The plunger 2 has a hole 2
a is provided. The hole 2a has a large diameter from the tip of the leakage type of the plunger 2 to the hollow portion, but has a small diameter from the hollow portion to the other tip, and is processed to have a step.

The base 3 is provided with a recess so that the portion abutting the plunger 2 fits with the leakage portion of the plunger 2. When the plunger 2 and the tip ends of the base 3 approach each other, the suction characteristic is improved. It has a structure that allows it to be used (leakage type). The other end of the base 3 is provided with a protrusion 3a. The base 3 is provided with a hole 3b so as to penetrate therethrough in the axial direction.

A coil 6 is wound around the body of the bobbin 5, and the bobbin 5 is arranged in the frame 1. In the hollow part of bobbin 5, a sleeve 1 with a diameter slightly smaller than that of bobbin 5
1 is penetrated. Further, the plunger 2 and the base 3 are passed through the hollow portion of the bobbin 5 via the sleeve 11. At this time, an air gap spacer 9 made of a non-magnetic material is interposed between the plunger 2 and the base 3. The projection 3a of the base 3 is fitted into the hole 1a of the frame 1, and the frame 1 and the base 3 are integrated. flame
A stator 4 is arranged so as to cover the upper part of 1.

The shaft 7 has a large-diameter portion and a small-diameter portion, and a head 7a for preventing slipping out is provided at the tip of the large-diameter portion so as to be larger than the diameter of the hole 3b of the base 3. A shaft 7 is arranged in the hole 3b of the base 3. Hole 3b in base 3
, Two ring-shaped bearings 10 and 10 'are arranged so as to sandwich the base 3, and slidably support the shaft 7. At the large diameter portion of the hole 2a of the plunger 2, a shaft 7 and a plunger spring 8 are arranged so as to be accommodated in a step with the small diameter portion. Further, the large diameter portion of the shaft 7 is penetrated so as to fit in the step between the large diameter portion and the small diameter portion of the hole 2a of the plunger 2. The plunger 2 and the shaft 7 are integrated by caulking. The winding start and winding end of the coil 6 are connected to the lead wire 12 and the lead wire 12 ', respectively.

Next, the operation of the conventional electromagnetic actuator will be described. Normally, when the coil 6 is not energized, the urging force of the plunger spring 8
Has left Base 3. When the coil 6 is energized,
The plunger 2 generates an electromagnetic force that opposes the urging plunger spring 8, and the frame 1, stator 4, plunger
2. A magnetic circuit is formed on the base 3, and the plunger 2 is attracted to the base 3. At this time, plunger 2 and base 3
Since the non-magnetic air gap spacer 9 is interposed therebetween, the plunger 2 and the base 3 are not completely in contact with each other, and a gap corresponding to the thickness of the air gap spacer 9 is formed.

When the plunger 2 is sucked by the base 3, the shaft 7 is integrated with the plunger 2. Therefore, the shaft 7 is also sucked by the base 3, and the shaft 7 is attached to the hole 1a of the frame 1.
Is pushed to the outside of the frame 1 and the push operation is performed.

When the coil 6 is de-energized, the plunger 2 is pushed back by the urging force of the plunger spring 8 to the position before energization. Air gap spacer 9 when energized
Since an appropriate gap is formed between the plunger 2 and the base 3 by this, residual magnetism does not accumulate.
Does not remain sucked into the base 3, and after the plunger 2 is de-energized, it is quickly returned to the position before energization by the urging force of the plunger spring 8.

[0010]

In the conventional electromagnetic actuator, when a defect such as disconnection of the coil 6 occurs, the electromagnetic actuator becomes inoperable, and a machine using the electromagnetic actuator is also available. It also became inoperable, creating a significant risk. Further, since the head 7a of the shaft 7 is a flat surface, there are a case where the device makes contact with the center of the plane of the head 7a to perform the push operation and a case where the device makes contact with the end surface of the head 7a to perform the push operation. , Clearly there was a difference in the acting force, and it was impossible to continue uniform movement.

The present invention has been made in view of the above problems, and in the event of a failure such as coil breakage, the present invention can continue to operate in an emergency and always operate uniformly. An electromagnetic actuator that can be continued is provided with a simple structure.

[0012]

According to a first aspect of the present invention, a plurality of solenoids that rotate or reciprocate in a plunger and a shaft when the coil is energized are arranged in the same straight line, and among the plurality of solenoids. The shaft of at least one solenoid is not fixed to the plunger and can move independently, so even if one of the solenoids fails and does not work, the other solenoids work Enabled to continue to work.

According to a second aspect of the present invention, a head is provided at the tip of the shaft of the at least one solenoid, and the head has a curved surface, so that no matter which part of the head abuts, it is always uniform. It was possible to perform various actions.

According to a third aspect of the invention, a projection is provided at the tip of the plunger of the at least one solenoid,
By providing the base with a recess so as to fit in the protrusion of the plunger, it is possible to exhibit a strong suction characteristic when the end face of the protrusion and the recess approach each other.

According to a fourth aspect of the invention, a protrusion is provided at the tip of the plunger of the at least one solenoid,
By providing a recess in the base so as to fit the protrusion of the plunger, it is possible to stably exhibit a constant suction characteristic even during a long stroke.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view of the present invention. In the figure, A is a main solenoid and B is a sub solenoid.
In each of A and B solenoids, 1 is a frame, 2 is a plunger, 3 is a base, 4 is a stator, 5 is a bobbin, 6 is a coil, 7 is a shaft, 8 is a plunger spring, 9 is an air gap spacer, 10 and 10 'Is bearing, 11 is sleeve, 12
And 12 'are lead wires, 13 is a solenoid spring, 14 is a retaining ring, and 15 is a housing.

First, the main solenoid A will be described. The frame 1 is made of a magnetic material and has a hole 1a at the bottom. The plunger 2 is processed into a leakage type with a protruding tip portion, so that the suction force at a desired stroke becomes strong. The plunger 2 is provided with a hole 2a so as to penetrate therethrough in the axial direction. The hole 2a
Has a large diameter from the leakage type tip of the plunger 2 to the hollow portion, but has a small diameter from the hollow portion to the other tip, and is processed to have a step.

The base 3 is provided with a recess so that the portion contacting the plunger 2 fits with the leakage portion of the plunger 2, and when the tip ends of the plunger 2 and the base 3 approach each other, the suction characteristic is improved. It has a structure that can be used. The other end of the base 3 is provided with a protrusion 3a. The base 3 is provided with a hole 3b so as to penetrate therethrough in the axial direction.

A coil 6 is wound around the body of the bobbin 5, and the bobbin 5 is arranged in the frame 1. In the hollow part of bobbin 5, a sleeve 1 with a diameter slightly smaller than that of bobbin 5
1 is penetrated. Further, the plunger 2 and the base 3 are passed through the hollow portion of the bobbin 5 via the sleeve 11. 4 and plunger 5 are inserted. At this time, an air gap spacer 9 made of a non-magnetic material is interposed between the plunger 2 and the base 3. The protrusion 3a of the base 3 is fitted into the hole 1a of the frame 1 so that the frame 1 and the base 3
Are integrated. Like covering the top of frame 1,
The stator 4 is arranged.

The shaft 7 has a large-diameter portion and a small-diameter portion, and a head 7a for preventing slipping out is provided at the tip of the large-diameter portion so as to be larger than the diameter of the hole 3b of the base 3, and the head 7a is also provided.
Is processed so that the tip has a smooth curved surface.

A shaft 7 is arranged in the hole 3b of the base 3. In the hole 3b of the base 3, two ring-shaped bearings 10 and 10 'are arranged so as to sandwich the base 3, and
7 is slidably supported. A plunger spring 8 is arranged in the large diameter portion of the hole 2a of the plunger 2. Further, the large diameter portion of the shaft 7 is penetrated so as to fit in the step between the large diameter portion and the small diameter portion of the hole 2a of the plunger 2. The shaft 7 is not fixed anywhere and can slide freely. A solenoid spring 13 is arranged on the end face of the plunger 2, and a portion of the small diameter portion of the shaft 7 projecting from the hole 2a of the plunger 2 penetrates therethrough. A retaining ring 14 is connected to the tip of the small diameter portion of the shaft 7 to prevent the solenoid spring 13 from falling off. The winding start and winding end of the coil 6 are connected to the lead wire 12 and the lead wire 12 ', respectively.

Next, the sub-solenoid B will be described. Since the sub-solenoid B has almost the same structure as the main solenoid A, only the differences will be described. For the shaft 7 of the sub-solenoid B, the large diameter part is the hole 2a of the plunger 2.
Is penetrated so as to fit in the step between the large diameter portion and the small diameter portion. The plunger 2 and the shaft 7 are integrated by caulking.

Next, the main solenoid A and the sub solenoid B
After the respective assembling is completed, the both are assembled to the housing 15. The housing 15 is made of a non-magnetic material and has a substantially U shape. When assembling, the shaft 7 of the main solenoid A and the shaft 7 of the sub-solenoid B are positioned on the same straight line, and when the shaft 7 of the sub-solenoid B projects from the hole 3a of the base 3, the sub-solenoid B The shaft 7 is arranged at an appropriate distance so that it can come into contact with the shaft 7 of the main solenoid A. The main solenoid A and the sub-solenoid B are fixed to the housing 15, respectively.

Next, the operation of the electromagnetic actuator of the present invention will be described. Normally, when the coil 6 of the main solenoid A is not energized, the plunger 2 is separated from the base 3 by the urging force of the plunger spring 8. When the coil 6 is energized from the lead wire 12, the plunger 2 generates an electromagnetic force that opposes the urging plunger spring 8, and a magnetic circuit is formed in the frame 1, the stator 4, the plunger 2, and the base 3. The plunger 2 is sucked by the base 3. At this time, since the non-magnetic air gap spacer 9 is interposed between the plunger 2 and the base 3, the plunger 2 and the base 3 are not completely in contact with each other, and the thickness of the air gap spacer 9 is equal. Only a gap is formed.

When the plunger 2 is sucked by the base 3, the shaft 7 is not fixed to any of the other components, but the large diameter portion of the shaft 7 is the large diameter portion and the small diameter portion of the hole 2a of the plunger 2. The shaft 7 is pushed into the hole of the frame 1
It is pushed to the outside of the frame 1 from 1a, and push operation is performed. Since the head 7a of the shaft 7 has a smooth curved surface, it is possible to perform a stable push operation with a uniform force no matter where the head 7a abuts against an external device.

When the coil 6 is de-energized, the plunger 2 is pushed back by the urging force of the plunger spring 8 to the position before energization. Air gap spacer 9 when energized
Since an appropriate gap is formed between the plunger 2 and the base 3 by this, residual magnetism does not accumulate.
Does not remain sucked into the base 3, and after the plunger 2 is de-energized, it is quickly returned to the position before energization by the urging force of the plunger spring 8. Since the main solenoid A of the electromagnetic actuator of the present invention is the leakage type of the plunger 2 and the base 3,
The suction force at a desired stroke can be increased.

If a problem such as disconnection of the coil 6 of the main solenoid A occurs during operation of the main solenoid A, the main solenoid A will not operate. However, the lead wire 12
When it is energized through, the plunger 2 generates an electromagnetic force that opposes the urging plunger spring 8, and a magnetic circuit is formed in the frame 1, the stator 4, the plunger 2, and the base 3, and the plunger 2 is attracted to the base 3. To be done. At this time,
Since a non-magnetic air gap spacer 9 is interposed between the plunger 2 and the base 3, the plunger 2 and the base 3
3 is not completely abutted, and a gap corresponding to the thickness of the air gap spacer 9 is formed.

Plunger 2 of sub solenoid B is base 3
Shaft 7 is integrated with the plunger 2, the shaft 7 is also sucked into the base 3,
The frame 7 is pushed out of the frame 1 through the hole 1a of the frame 1 to perform a push operation. At this time, the sub solenoid
The shaft 7 of B contacts the shaft 7 of the main solenoid A. Since the shaft 7 of the main solenoid A is not fixed anywhere, it can be operated with a slight force, and the shaft 7 of the main solenoid A is pushed by the shaft 7 of the sub-solenoid B to The frame 1 is pushed out of the hole 1a to the outside of the frame 1 to perform a push operation.

When the energization of the coil 6 of the sub-solenoid B is released, the plunger 2 of the sub-solenoid B is pushed back by the urging force of the plunger spring 8 to the position before energization. When energized, an appropriate gap is formed between the plunger 2 and the base 3 by the air gap spacer 9, so residual magnetism does not accumulate.Therefore, when the energization is released, the plunger 2 is attracted to the base 3 by the action of residual magnetism. It does not stay as it is, it is a sub solenoid
After de-energizing the plunger 2 of B,
The urging force of 8 quickly returns to the position before energization.

When the plunger 2 of the sub-solenoid B returns to the position before energization, the shaft 7 of the main solenoid A returns to the position before energization by the urging force of the solenoid spring 13. By repeating the above operation, even if the main solenoid A has a problem such as the disconnection of the coil 6, the main solenoid A can be continuously operated by the sub solenoid B.

FIG. 2 shows an embodiment of the invention of claim 5. In the figure, A is a main solenoid and B is a sub-solenoid. In each of A and B solenoids, 1 is a frame, 2 is a plunger, 3 is a base, 4 is a stator, 5 is a bobbin, 6 is a coil, 7 is a shaft, 8 is a plunger spring, 9 is an air gap spacer, 10 and 10 'Is a bearing, 11 is a sleeve, 12 and 12' are lead wires, 13 is a solenoid spring, 14 is a retaining ring, and 15 is a housing.

In the invention of claim 5, the tip end of the plunger 2 is processed into a conical shape, and the base 3 is also dug into a mortar shape so that the plunger 2 can be housed. (Conical type) Therefore, even if the stroke becomes long, it is possible to stably maintain a constant output.

[0033]

As an effect of the present invention, according to the invention of claim 1, when the coil is energized, the plurality of solenoids for rotating or reciprocating the plunger and the shaft are arranged in the same straight line, and the plurality of solenoids are arranged. The shaft of at least one of the solenoids is not fixed to the plunger and is movable independently, so that even if one of the solenoids fails and does not work, the other solenoids work. This made it possible to continue operating steadily.

According to the invention of claim 2, the at least 1
A head is provided at the tip of the shaft of the two solenoids,
Since the head has a curved surface, it is possible to always perform a uniform operation regardless of which part of the head comes into contact.

According to the invention of claim 3, the at least 1
A protrusion is provided on the tip of the plunger of the two solenoids, and a recess is formed on the base so as to fit with the protrusion of the plunger, so that a strong suction is exerted when the end face of the protrusion and the recess approach each other. It became possible to show the characteristics.

According to the invention of claim 4, the at least 1
A protrusion is provided at the tip of the plunger of the two solenoids, and a recess is provided in the base so as to fit with the protrusion of the plunger, so that a stable suction characteristic can be stably exhibited even during a long stroke. It became possible. As described above, the present invention can provide an electromagnetic actuator that continues to operate steadily because another solenoid performs a preliminary operation in an emergency even if a malfunction occurs,
The industrial applicability is great.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention.

FIG. 2 is another embodiment of the present invention.

FIG. 3 Conventional example

[Simple explanation of symbols]

A: Main solenoid B: Sub solenoid 1: Frame 2: Plunger 3: Base 4: Stator 5: Bobbin 6: coil 7: Shaft 8: Plunger spring 9: Air gap spacer 10: Bearing 10 ': bearing 11: Sleeve 12: Lead wire 12 ': lead wire 13: Solenoid spring 14: Retaining ring 15: Housing

Claims (4)

[Claims] 1. When a coil is energized, a plurality of solenoids that rotate or reciprocate when the plunger and shaft rotate are arranged in the same straight line, and at least one solenoid shaft of the plurality of solenoids is fixed to the plunger. An electromagnetic actuator characterized by being capable of moving independently. 2. The electromagnetic actuator according to claim 1, wherein a head is provided at a tip of a shaft of the at least one solenoid, and the head has a curved surface. 3. A projection is provided at the tip of the plunger of the at least one solenoid, and a recess is provided in the base so as to fit into the projection of the plunger. An electromagnetic actuator according to claim 2. 4. The plunger of the at least one solenoid is conically processed at its tip end, and the base is provided with a recess for fitting into the conical tip end of the plunger. Item 2. The electromagnetic actuator according to Item 2.