JP2009081222A - Electromagnet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnet apparatus capable of efficiently performing the attracting operation at a low cost while using an iron core or a moving iron equivalent to that as before, and further capable of ensuring a required stroke. <P>SOLUTION: In the electromagnet apparatus requiring a predetermined stroke, the electromagnet apparatus is formed of a yoke, the moving iron arranged opposed to both ends of the yoke so that they are separated by a predetermined air gap between them, and an electrically conductive member provided to penetrate the magnetic circuit comprising the yoke and the moving iron so that the current flowing through the member gives a magnetomotive force to the magnetic circuit. The moving iron is provided biased by an elastic member in the direction for maintaining the predetermined air gap, and the yoke is provided rockably supported so that the size of one air gap becomes smaller with the penetrating direction of the electrically conductive member being made into the axial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an electromagnet device, and more particularly to an electromagnet device capable of performing a suction operation efficiently at a low cost in a flat electromagnet.

Conventionally, as a method of improving the attractive force in an electromagnet device, a method of increasing the magnetic flux saturation value of the iron core and a method of increasing the attractive cross-sectional area have been cited. Here, since the magnetic flux saturation value of the iron core has been used to the limit, it has been difficult to increase the magnetic flux saturation value any more, and the size of the electromagnet itself is large for the attraction cross-sectional area. However, it has been pointed out that there is a drawback that the weight increases as well (Patent Document 1).

In order to solve these drawbacks, Patent Document 1 aims to effectively increase the magnetic flux saturation value of the iron core and thus improve the attractive force of the electromagnet without increasing the size and weight of the electromagnet itself. The cross-sectional area of the inner-side magnetic flux return part of the suction iron core gradually increases in the opposite direction to the movable iron piece, and the cross-sectional area at the maximum position is more than twice the tip area of the return part. A flat plate type electromagnet is provided.

Also, in the electromagnet device, the attractive force varies depending on the size of the gap provided between the iron core and the movable iron piece attracted to the iron core due to its structure, and the attractive force is reduced by reducing the gap. This is what is known in the art. However, since the size of the gap is related to the stroke size of the electromagnet, it is natural that when the gap is small, the stroke is also small, so it is not suitable for providing an electromagnet with a large stroke. Met.

Japanese Patent Laid-Open No. 7-50212, paragraph numbers “0006” to “0009”

However, the cross-sectional area of the inner-side magnetic flux return part of the attracting iron core in the electromagnet is gradually increased in the opposite direction to the movable iron piece, and the cross-sectional area at the maximum position is more than twice the tip area of the return part. When the electromagnet is constructed with the characteristics of the above, the cost of each part is expected to increase compared to a normal electromagnet, and when considering the assembly of each part, the winding diameter fluctuates compared to the normal coil winding method. For this reason, there is a problem in terms of cost when producing a large quantity at a low cost, such as the need to introduce new production equipment.

Further, when providing an electromagnet that requires a predetermined stroke, there is a problem that the predetermined stroke cannot be obtained if the gap is simply made small in order to improve the attractive force. .

Therefore, in the present invention, in order to improve the attraction force of the electromagnet, the method of increasing the magnetic flux saturation value of the iron core and the method of increasing the attraction cross-sectional area, which have been conventionally disclosed, can be used. The cross-sectional area of the inner magnetic flux return part of the core is gradually increased in the opposite direction with respect to the movable iron piece, and the cross-sectional area at the maximum position is more than twice the tip area of the return part. Provide an electromagnet device capable of performing a suction operation efficiently at low cost while using the same core and movable iron pieces as the conventional one, and also provide an electromagnet device capable of ensuring a required stroke. For the purpose.

In order to achieve the above object, in claim 1 of the present invention, in an electromagnet apparatus that requires a predetermined stroke,
The electromagnet device is
With a yoke,
A movable piece arranged opposite to the predetermined gap at both ends of the yoke;
A conductive member that is inserted so as to give a magnetomotive force to the magnetic circuit composed of the yoke and the movable piece, and that conducts current;
Consisting of
The movable piece is urged and arranged in a direction to keep the predetermined gap by an elastic member,
The yoke provides an electromagnet device characterized in that the yoke is swingably supported so as to reduce the size of one of the gaps with the direction of penetration of the conductive member as the axial direction.

The suction force required to start attracting the movable piece needs to be larger than the urging force of the movable piece by the elastic member (assuming the urging force is F1).
The attractive force (attractive force is assumed to be F) generated in a magnetic circuit through predetermined air gaps (the sizes of the respective voids are assumed to be L1 and L2),
When the yoke is fixedly arranged as in the prior art, it is expressed as F = α × I ² / (L1 + L2) ² where α is a constant and I is a current magnitude.
When the yoke is swingably supported as in the present invention, the size of the gap fluctuates in a direction that decreases from a predetermined size. Assuming that the minimum value of the gap in the case of L1 and L2 ′ is set, the relationship is (L1 + L2)> (L1 + L2 ′).
Therefore, the magnitude of the current I required to generate the predetermined attractive force F can be reduced.
The yoke is supported and disposed so as to be swingable with the penetration direction of the conductive member as an axial direction, so that a predetermined gap can be maintained and a predetermined stroke can be ensured. It is something that can be done.
As a result, it is possible to provide an electromagnet device capable of efficiently performing a suction operation at low cost, and to provide an electromagnet device capable of ensuring a required stroke.

The yoke is
Of the gaps provided between the yoke and the movable piece, without changing the size of the predetermined gap provided at one end of the yoke,
The electromagnet device may be configured such that the predetermined gap provided in the other end portion is provided in a loose-fitting state in the case that supports the yoke so that the size of the gap changes small.

As a result, an electromagnet device capable of performing a suction operation efficiently at low cost because it is only necessary to provide the case in a loosely fitted state without providing a special support member for supporting the yoke. In addition, it is possible to provide an electromagnet device that can secure a required stroke.

The movable piece is formed in a substantially flat plate shape,
The yoke may be configured to be formed in a substantially U shape, and an electromagnet device may be provided.

Accordingly, the movable piece and the yoke can be formed in a very general shape without forming in a special shape, and the production cost can be reduced as much as possible.

The movable piece is attached to an actuating member that is urged in a direction to keep the gap and is rotatable.
When a current flows through the conductive member and the electromagnet device operates, on the trajectory on which the operating member that operates together with the movable piece attracted by the yoke operates,
An electromagnet device may be configured by using an action member for a third member formed by contact of the operating member.

As a result, an electromagnet device that can act on the third member by operating the electromagnet device and that can perform a suction operation efficiently at low cost and secures a required stroke is provided. It is possible to provide an electromagnet device that can be used.

According to the present invention, in order to improve the attraction force of the electromagnet, the method of increasing the magnetic flux saturation value of the iron core or the method of increasing the attraction cross-sectional area, which have been conventionally disclosed, can be used. The cross-sectional area of the inner-side magnetic flux return part of the iron core is gradually increased in the opposite direction to the movable iron piece, and the cross-sectional area at the maximum position is more than twice the tip area of the return part, We provide an electromagnet device that can perform suction operation efficiently at low cost while using the same iron core and movable iron pieces as before, and also provide an electromagnet device that can secure the required stroke. can do.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 4 show a first embodiment of the present invention. First, the structure of the electromagnet device of the present invention will be described.

Reference numeral 100 denotes an electromagnet device of the present invention. The electromagnet device 100 includes a yoke 101, a movable piece 102 disposed opposite to the yoke 101 with a predetermined gap (the sizes of the gaps are L1 and L2) at both ends, and the yoke 101. A conductor member 103, which is inserted so as to apply a magnetomotive force to a magnetic circuit composed of iron 101 and the movable piece 102 and flows current; an elastic member 104 which urges the movable piece 102 in the direction of maintaining the gap; A yoke 105 for housing the yoke 101 and the movable piece 102 is provided.

The yoke 101 has two protruding portions 1011 formed at one end of the yoke 101 in the vertical direction in the figure, and the protruding portions 1011 are supported by a yoke support portion 1052 provided on the case 105. As a result, the direction of penetration of the conductive member 103 is set as the axial direction, that is, the direction connecting the protruding portions 1011 is set as the axis, and the end portion opposite to the end portion where the protruding portions 1011 are provided. The gap (L2) is swingably disposed so as to reduce the size of the gap (L2).

The yoke support portion 1052 is provided with a rib formed on a part of the case 105 to such an extent that the protruding portion 1011 can be fitted into the loosely fitted state.

As shown in the figure, the movable piece 102 is configured such that a rotating shaft 1021 provided on the movable piece 102 is supported by a movable piece support portion 1051 provided on a case 105.

Further, with the direction connecting the projecting portions 1011 as an axis, it can be swung so that the size of the gap (L2) at the end opposite to the end provided with the projecting portions 1011 can be reduced. As shown in FIG. 4, a predetermined clearance is provided between the side opposite to the side where the protruding portion 1011 is provided and the case. As a result, the yoke 101 is supported and arranged so as to be swingable between the state shown in FIG. 1 and the state shown in FIG.

Next, the operation of the electromagnet device 100 will be described.

First, the suction force required to start attracting the movable piece 102 needs to be larger than the urging force of the movable piece 102 by the elastic member 104 (assuming the urging force is F1).
Here, the attractive force (attractive force is F) generated in the magnetic circuit through the predetermined air gaps (the sizes of the respective air gaps are L1 and L2) is:
When the yoke is fixedly disposed as in the prior art, α is a constant (α is represented by the product of permeability, number of coils wound on the yoke, and cross-sectional area of the yoke), I Is expressed as F = α × I ² / (L1 + L2) ² , where
When the yoke is swingably supported as in the present invention, the size of the gap (L2) varies in a direction that decreases from a predetermined size. In this case, the suction force is expressed as F = α × I ² / (L1 + L2 ′) ² .
Since the size of the gap is (L1 + L2)> (L1 + L2 ′), the suction force is large when the size of the gap is small (L1 + L2 ′) when the current size is the same.

The relationship between these gaps (L1 + L2) and (L1 + L2 ′) and the suction force is shown in FIG. That is, the air gap becomes smaller and the suction force becomes larger. Here, the suction force when the gap is (L1 + L2 ′) is F2.

FIG. 6 shows the relationship between the suction force and the current I until the suction force reaches F1 when the gap is of each size. When the gap size is (L1 + L2), the current value at which the suction force reaches the magnitude of F1 is defined as I1, and when the gap size is (L1 + L2 ′), the current at which the suction force reaches the magnitude of F1 If the value is I2, the relation of I1> I2 is established. That is, the magnitude of the current I necessary to generate the predetermined attractive force F1 is proportional to the size of the gap.

Since the yoke 101 is supported and disposed so as to be swingable with the penetration direction of the conductive member 103 as an axial direction, the predetermined gap size can be maintained, and the predetermined stroke is It has been secured.

When a current is passed through the conductive member 103 provided in the electromagnet device 100, a magnetomotive force is generated in the electromagnet device 100.

Here, an attractive force corresponding to the magnitude of the current is generated between the yoke 101 and the movable piece 102. When the current is gradually increased, first, as shown in FIG. The suction force increases like “A”.

When the force necessary to cause the swing of the yoke 101 is F3, the gap L2 is reduced in the yoke 101 when the current reaches I3 with the projecting portion 1011 as the axis center. Sucked into. Therefore, the size of the gap of the electromagnet 100 changes from (L1 + L2) to (L1 + L2 ′).

Then, since the relationship between the current and the attractive force becomes “B” shown in FIG. 6, the attractive force increases even at the same current I3, and the attractive force reaches F1 when the magnitude of the current becomes I2. Finally, the movable piece 102 urged by the elastic member 104 starts to drive in the direction of the yoke 101, and the suction force increases and is attracted to the yoke 101 in combination with the narrowing of the gap.

As shown in the figure, the movable piece 102 is configured such that the rotating shaft 1021 provided on the movable piece 102 is supported by the movable piece support portion 1051 provided on the case 105. In the suction operation, even if the gap (L2 ′) in the swinging yoke 101 is zero, the other gap (L1) is not zero, so the suction operation is continued and the L1 is zero. Move from the initial position until That is, the adsorption state shown in FIG. 3 is obtained.

As described above, the gap (L2) is changed to a size (L2 ′) smaller than (L2) in the course of adsorption due to the swing of the yoke 101, but finally the movable piece. When 102 is adsorbed to the yoke 101, the movable piece 102 moves by the size of the original gap (L1 and L2), so that a predetermined stroke can be ensured.

Next, a second embodiment will be described.
FIG. 7 schematically shows the second embodiment.

In the present embodiment, the movable piece 102 described above is attached to an actuating member 106 that is urged in a direction that maintains a gap between the movable piece 102 and the yoke 101 and that is rotatable.

The actuating member 106 is provided with a rotating shaft 1061, and a third member 107 is provided at the end of the actuating member 106 so as to face each other at a predetermined interval. Here, the third member 107 is assumed to be a switch, and when the electromagnet device 100 is operated, the movable member 102 is attracted and the operating member 106 is rotated so that the operating member 106 is rotated. On the locus of movement of the end portion of 106, the third member 107 abuts and the actuating member acts like an actuator.

Next, a third embodiment will be described.
8 to 10 show a third embodiment. In the third embodiment, an electromagnet device is applied to a circuit breaker.

Nowadays, as a function of the circuit breaker incorporated in the distribution board, it is desired to have a function of protecting a relatively small short circuit (cord short circuit) generated on the load side from the outlet circuit. However, in the conventional electromagnetic trip device,
In the region of a comparatively small short circuit (cord short circuit) as described above, the electromagnetic force generated by the short circuit current is smaller than the normal short circuit current. Therefore, the force (attraction force) that the movable iron piece is attracted to the electromagnetic frame is weak, and the electromagnetic tripping device may not be driven sufficiently.

If the electromagnetic trip device does not drive sufficiently, the latch part of the trip member cannot be removed by the operation of the movable piece, and as a result, the contact cannot be separated, and the electric circuit Can not be cut off.

As a condition for tripping the latch portion of the tripping member, the suction force needs to be larger than the force that prevents the latch portion of the opening / closing mechanism from being tripped.
That is, there are two forces that prevent the latch part from being tripped: a force for releasing the latch of the latch part (engagement force) and a force for biasing the tripping member by the biasing spring (biasing force). For this reason, it is necessary that the attractive force be larger than the resultant force at the position where the electromagnetic trip device acts on the trip member.

For example, as a solution for reducing the magnitude of the short-circuit current at which the tripping device starts to be driven so that the tripping operation can be performed in a relatively small short-circuit (cord short-circuit) region, the biasing spring is applied. In order to overcome the resultant force of the force and the engaging force, as described above, the method of increasing the magnetic flux saturation value of the iron core, the method of increasing the suction cross-sectional area, and the inside of the iron core for attraction in the electromagnet are disclosed. The cross-sectional area of the side flux return part is gradually increased in the opposite direction to the movable iron piece, and the cross-sectional area at the maximum position is more than twice the tip area of the return part. As a result, the size of the tripping device and the special shape of the tripping device may increase, leading to an increase in cost, and it is not practical to apply them.

In order to increase the electromagnetic force acting on the movable piece without increasing the size of the circuit breaker body, a method of narrowing the magnetic gap δ between the movable piece and the yoke can be considered. The magnetic gap δ is proportional to the electromagnetic force F (attraction force) by 1 / δ ² . However, reducing the magnetic gap reduces the amount of movement of the movable piece. The movable piece must have a minimum amount of movement necessary for tripping the latch portion, and there is a limit in reducing the magnetic gap δ and increasing the electromagnetic force.

In view of such a problem, the third embodiment provides a circuit breaker that can reliably operate even in a relatively small short-circuit (cord short-circuit) region without increasing the size of the circuit breaker body. Therefore, an electromagnet device is applied to a circuit breaker.

FIG. 8 shows an example in which an electromagnet device is used as an electromagnetic trip device in a circuit breaker. The electromagnet device 100 forms a magnetic circuit composed of a U-shaped yoke 101 and a movable piece 102, and a conductive member 103 is provided on the inside thereof. The movable piece 102 is urged by the elastic member 104 in the direction in which the magnetic circuit is opened.

In the conventional circuit breaker electromagnetic tripping device, since the yoke 101 serving as an electromagnetic frame is fixed, the size of the gap (referred to as a magnetic gap) with the movable piece 102 is the amount of movement of the movable piece 102. . Therefore, the magnetic gap is used to trip the latch of the latch mechanism portion on which the movable piece 102 acts in order to open the contact of the circuit breaker when an abnormal current (overcurrent or short circuit current) flows in the electric circuit. It was necessary to secure at least the necessary amount of movement.

In the present invention, the U-shaped yoke 101 is provided with a convex recess 1011 at one end, and the other end is configured to be swingable in the direction in which the magnetic gap is narrowed with the convex recess as a fulcrum. When a short-circuit current starts to flow in the electric circuit, one arm portion of the yoke 101 approaches (turns) the movable piece side by electromagnetic force.

When one of the arm portions approaches the movable piece side and the magnetic gap becomes narrow, the electromagnetic force (attraction force) increases, and the movable piece 102 overcomes the urging force of the elastic member and starts moving toward the yoke side. Even if the movable piece comes into contact with the arm on one side of the yoke, there is a magnetic gap between the arm and the other arm of the yoke, so contact with one arm of the electromagnetic frame to close the magnetic circuit Keep moving. Therefore, the moving amount of the movable piece can be moved by the same distance as when the electromagnetic frame of the conventional circuit breaker is fixed.

The yoke 101 is held from both sides by a mold member, both ends of one arm portion are formed in a concave and convex shape, and a shape is provided on the case side of the circuit breaker holding the yoke 101 so as to fit the concave and convex shape. The other arm portion is not completely sandwiched between the mold members, and a gap is provided so that the uneven shape of the opposite arm portion does not deviate from the uneven shape of the case. Thereby, the yoke 101 is arrange | positioned so that rocking is possible by making a convex recessed part into a fulcrum.

Alternatively, a shaft portion may be provided on one arm portion of the U-shaped yoke 101 so that the shaft portion is swingably held around the shaft portion.

Note that the present invention is not limited to the embodiments, and can be freely improved and modified as needed, as long as it does not depart from the gist of the invention.
The protruding portion 1011 provided on the yoke 101 and the yoke support portion 1052 into which the protruding portion 1011 is fitted in a loosely fitted state are processed into a concave shape on the yoke side, and the yoke support portion is You may form and project so that it may fit into a shape.

In addition, with respect to the rotating shaft 1021 provided on the movable piece 102 and the movable piece support portion 1051 that supports the rotating shaft, the movable piece side is processed into a concave shape, and the case side is fitted to the concave shape. A protrusion may be formed and configured.

Thus, in the electromagnetic tripping device, when a short-circuit current starts to flow, one arm portion of the yoke is attracted to the movable piece, and the magnetic gap δ is narrowed, thereby reducing the magnetic resistance of the magnetic circuit. , The electromagnetic force acting on the movable piece increases. Next, the movable piece overcomes the urging spring force and acts on the latch mechanism to release the latch. By making the yoke movable, the magnetic resistance of the magnetic circuit is reduced, and even when the electromagnetic force is generated by a relatively small current, the force acting on the latch mechanism is sufficient. The drive start current of the electromagnetic trip device can be reduced, and the circuit breaker body can be reduced in size and reliably in a small but relatively short circuit (cord short) region. A circuit breaker capable of operation can be provided.

The present invention is applicable to an electromagnet device that requires a predetermined stroke and can be driven efficiently even when the drive current is small. Further, the present invention can be applied to a circuit breaker capable of performing a reliable breaking operation even in a relatively small short-circuit (cord protection) region without increasing the size of the vessel. In addition, since it is not necessary to use parts having complicated shapes, it is effective for automation in assembling circuit breakers, and further improvement in productivity can be desired.

External view of electromagnet device External view of electromagnet device External view of electromagnet device External view of electromagnet device Relationship between air gap (L1 + L2), (L1 + L2 ') and suction force Relationship between attractive force and current I External view of the electromagnet device of the second embodiment External view of the electromagnet device of the third embodiment External view of the electromagnet device of the third embodiment External view of the electromagnet device of the third embodiment

Explanation of symbols

101 Movable Iron Piece 102 Electromagnetic Frame 103 Biasing Spring 104 Conductor 105 Base

Claims (4)

In an electromagnet device requiring a predetermined stroke,
The electromagnet device is
With a yoke,
A movable piece arranged opposite to the predetermined gap at both ends of the yoke;
A conductive member that is inserted so as to give a magnetomotive force to the magnetic circuit composed of the yoke and the movable piece, and that conducts current;
Consisting of
The movable piece is urged and arranged in a direction to keep the predetermined gap by an elastic member,
The electromagnet device, wherein the yoke is supported and disposed so as to be swingable with an insertion direction of the conductive member as an axial direction. The yoke is
Of the gaps provided between the yoke and the movable piece, without changing the size of the predetermined gap provided at one end of the yoke,
2. The electromagnet device according to claim 1, wherein the electromagnet device is provided in a loosely fitted state in a case supporting the yoke so that a size of a predetermined gap provided in the other end portion is changed small. The movable piece is formed in a substantially flat plate shape,
The electromagnet device according to claim 1, wherein the yoke is formed in a substantially U shape. The movable piece is attached to an actuating member that is urged in a direction to keep the gap and is rotatable.
When a current flows through the conductive member and the electromagnet device operates, on the trajectory on which the operating member that operates together with the movable piece attracted by the yoke operates,
The electromagnet device according to any one of claims 1 to 3, wherein the electromagnet device is an action member for a third member formed by abutting action of the operating member.

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