JP5389050B2 - Magnetic contactor - Google Patents

Description

  The present invention relates to an electromagnetic contactor that performs open / close control of a power device such as a step-down motor or a power factor improving capacitor, and more particularly to an electromagnetic magnet unit that performs on / off operation of a main contact.

In the electromagnetic contactor, the main contact is turned on and off using the attractive force of the electromagnetic magnet. For example, a conventional electromagnetic contactor as shown in FIG. 5 is known. An electromagnetic magnet 34 composed of an iron core 31 and a coil 32 and a yoke 33 wound around the iron core 31 is provided. When the coil 32 is excited, the movable iron plate 35 is attracted and a rotating shaft 36 to which the movable iron plate is attached is provided. In conjunction with this, the support plate 37 rotates upward, the operating rod of the vacuum valve 38 connected to the support plate moves upward, and the main contact built in the vacuum valve 38 is turned on. The When the excitation of the coil 32 is released, the main contact is opened by rotating the rotating shaft 36 counterclockwise by a spring member (not shown).
A magnetic shielding plate 39 is provided in the gap between the iron core 31 of the electromagnetic magnet 34 and the movable iron plate 35. The magnetic shielding plate 39 is for preventing a malfunction due to residual magnetism by reducing the cross-sectional area of the magnetic path, and substantially functions as a gap. In the case of FIG. 5, a magnetic shielding plate 39 made of a flexible member is sandwiched between washers and bolted to the iron core 31 (see Patent Document 1).

Japanese Utility Model Publication No. 61-151305 (page 2-4, Fig. 1)

The attractive force of the electromagnetic magnet varies greatly depending on the gap in the contact portion between the mover (movable iron plate) and the yoke (or iron core). The mover and the yoke (or iron core) collide each time the main contact enters the state, and the state of the contact portion changes depending on the number of collisions. For this reason, when a magnetic shielding plate is inserted in the gap, it is firmly attached without loosening, there is little dimensional change due to impact at the time of opening and closing, and the magnetic shielding plate is worn or deteriorated by repeated collisions It is desirable that the case be easily replaced.
In the electromagnetic contactor using the electromagnetic magnet shown in Patent Document 1, since the magnetic shielding plate is fixed to the iron core by the bolt, there is a problem that the bolt may be loosened and fall off due to repeated impacts. In addition, there is a problem that it takes time to replace the bolt because the bolt must be removed for replacement. Furthermore, since the washer part which becomes a magnetic pole head is exposed, there is a problem that foreign matter and dust are easily attached.

  The present invention has been made to solve the above-described problems, and is resistant to repeated impacts, hardly adheres to foreign matters and dust on the magnetic pole part, and has an electromagnetic contact plate equipped with a magnetic shielding plate that is easy to mount. The purpose is to provide a vessel.

An electromagnetic contactor according to the present invention includes an electromagnetic magnet, a flat plate-like movable element driven in the direction of the electromagnetic magnet by excitation of the electromagnetic magnet, and a pair of main contacts that are driven in conjunction with the driving of the movable element. In an electromagnetic contactor having a vacuum valve with a built-in contact, the electromagnetic magnet is wound around the body of a bobbin having an axial center along the suction direction of the mover and at least a flange on the suction side of the mover has been an electromagnetic coil, a cylindrical iron core armature facing the pole head is formed on one end side is inserted in the axial direction of the bobbin, both sides of Rutotomoni electromagnetic coil is fixed to the other end of the core And a yoke having a U-shaped cross section that surrounds the magnetic head , and has an outer dimension larger than the outer diameter of the magnetic pole head at the flange of the bobbin on the magnetic pole head side. Magnetic shielding covering the suction surface of the head The mover is positioned so that the surface of the mover is substantially uniformly opposed to the contact surface of the magnetic shielding plate so that there is no gap at the position attracted by the electromagnetic magnet and contacts the opening side end surface of the yoke. It is what is arranged .

According to the electromagnetic contactor of the present invention, the electromagnetic magnet for driving the main contact has an outer dimension larger than the outer diameter dimension of the magnetic pole head at the flange portion of the bobbin on the magnetic pole head side , and the magnetic head attraction surface. The armature is covered with a magnetic shield, and at the position where the mover is attracted to the electromagnetic magnet, the surface of the mover faces the contact surface of the magnetic shield plate almost uniformly and there is no gap. Because the magnetic gap is kept almost constant, there is little deformation and wear against repeated impacts during the attracting operation of the mover, and the amount of change in electromagnetic force can be kept small. it can.
Also, since the entire pole head part, a large barrier becomes covered by it in conditioning plates so that there is no exposed portion can prevent the foreign metal substance or dust or the like or PCB attached or enters the magnetic pole head, trust A highly magnetic contactor can be obtained.

It is a figure which shows the structure of the electromagnetic contactor by Embodiment 1 of this invention, (a) is a side cross section, (b) is the partial front view of the electromagnetic magnet part seen from the arrow b of (a). It is a perspective view of the electromagnetic magnet part of FIG. It is a perspective view explaining the shielding board attachment method of the electromagnetic coil of the electromagnetic magnet of FIG. It is a figure which shows the relationship between the gap of a needle | mover and a magnetic pole head, and electromagnetic force. It is a figure which shows the structure of the conventional electromagnetic contactor.

Embodiment 1 FIG.
Hereinafter, the electromagnetic contactor according to Embodiment 1 will be described with reference to the drawings.
First, the overall configuration will be described with reference to FIG. A vacuum valve 1 incorporating a main contact made up of a fixed contact 1a and a movable contact 1b is housed inside the insulating frame 2 for three phases. The fixed contact 1 a is connected to a fixed rod 1 c, and the fixed rod 1 c is led out of the container of the vacuum valve 1 and connected to the fixed side terminal 3 and is fixed to the insulating frame 2. On the other hand, the movable contact 1b is connected to a movable rod 1d that can move in the contact / separation direction of the contact. The movable rod 1d is led out to the outside and connected to the movable terminal 5 via the flexible conductor 4, and is connected to one of the insulating rods 6 coaxial with the movable rod 1d. The other side of the insulating rod 6 is connected to one end of the open / close lever 8 via a contact pressure spring 7 that applies contact pressure between both contacts.

The other end of the opening / closing lever 8 is fixed to a rotating shaft 9, and by rotating about the axis of the rotating shaft 9 as a fulcrum, the insulating rod 6 and the movable rod 1 d connected thereto are connected via the contact pressure spring 7. Are reciprocated in the contact / separation direction of both contacts 1a, 1b. As shown in FIG. 1B, the rotation shaft 9 is rotatably supported on both side surfaces of the insulating frame 2 fixed to the base 10 via bearings 11.
Further, a movable element 12 that rotates in conjunction with the opening / closing lever 8 is fixed to the rotation shaft 9. An electromagnetic magnet 13 that attracts the movable element 12 by electromagnetic force and rotates the rotation shaft 9 in the direction in which the contact is inserted is disposed on the base 10 so as to face the movable element 12. Details of the electromagnetic magnet 13 and the vicinity of the contact portion between the electromagnetic magnet 13 and the mover 12 will be described later.

Further, as shown in FIG. 1B, the rotating shaft 9 is provided with a contact opening lever 14, and an opening spring 15 is disposed opposite the lever 14. The release spring 15 is biased in a direction opposite to the suction direction of the mover 12 and functions to open the main contact by pressing the lever 14 and turning the turning shaft 9.
A stopper 16 is provided on the side opposite to the suction side of the mover 12 so that the lever 14 does not rotate beyond a predetermined angle even if the lever 14 is pressed by the release spring 15 and the rotation shaft 9 rotates. .
As described above, the electromagnetic contactor drives the movable element 12 by exciting the electromagnetic magnet 13, and drives the movable contact 1 b of the main contact of the vacuum valve 1 in conjunction with the drive of the movable element 12 to make contact and separation. Thus, the main contacts 1a and 1b are opened and closed, but the configuration of the main circuit section from the vacuum valve 1 to the rotating shaft 9 shows an example, and is not limited to the shape shown in FIG.

Next, details of the vicinity of the electromagnetic magnet 13 and the mover 12 will be described based on the cross-sectional view of FIG. 1A and FIGS. 2 and 3.
As shown in the cross-sectional view of FIG. 1A, the electromagnetic magnet 13 is inserted into the body of the bobbin 17 having the flanges 17a at both ends and the body of the bobbin 17, and is inserted into one end. A cylindrical iron core 19 having a magnetic pole head 19a facing the mover 12 on the side is fixed to the other end of the iron core 19 by bolting or the like, and is provided so as to surround the side of the electromagnetic coil 18. It has a yoke 20 (see also FIG. 2). The yoke 20 is fixed to the base 10 by bolting a mounting foot 20a provided on the lower side.
On the magnetic pole head 19a side of the iron core 19, there is disposed a permanent magnet 21 for attracting the mover 12 and maintaining the charged state of the main contact of the vacuum valve 1. The size of the permanent magnet 21 is substantially the same as the outer diameter of the iron core 19.

As shown in FIGS. 2 and 3, a shield plate 22 having a size covering the magnetic pole head 19 a is detachably provided on the flange portion 17 a of the bobbin 17 on the magnetic pole head 19 a side of the iron core 19. When the permanent magnet 21 is provided, it is naturally a size that covers the permanent magnet 21. The magnetic shielding plate 22 is provided to stabilize the attractive force, and details of the action will be described later.
As the magnetic shielding plate 22, for example, a rectangular thin plate made of brass or phosphor bronze is used. The thickness is, for example, 0.26 mm, the width is such a dimension that the magnetic pole head 19a (or the permanent magnet 21) is hidden as described above, and the bent curved surface 22a bent at a right angle is formed on the two opposing sides. Each folding surface 22a is provided with a rectangular attachment hole 22b.

On the other hand, on the top and bottom of the flange portion 17a on the magnetic pole head 19a side of the bobbin 17, projections 17b that engage with the mounting holes 22b are formed. The dimension between the outer end surfaces of the upper and lower protrusions 17b is set slightly longer than the dimension between the folding surfaces 22a of the magnetic shielding plate 22.
As shown in FIG. 3, the magnetic shield plate 22 is attached by engaging one projection 17b in one mounting hole 22b of the folding surface 22a and pushing the other in the direction of an arrow, thereby elastically bending the folding surface 22a. The other protrusion 17b is inserted into the other mounting hole 22b and engaged. The engaged state is shown in FIG.

The relationship between the electromagnetic magnet 13, the magnetic shielding plate 22 and the mover 12 configured as described above is that when the mover 12 is attracted to the magnetic pole head 19a, the surface of the mover 12 facing the magnetic pole head 19a is shielded. The mutual arrangement relation is made so that there is no gap while facing the surface of the magnetic plate 22 almost uniformly.
When the mover 12 is attracted, the surface of the mover 12 may be in direct contact with the magnetic shielding plate 22, but it is preferable to contact the end surface of the yoke 20 on the opening side (the magnetic pole head 19a side). Even when used for a long time, the parallelism with the magnetic pole head 19a is less likely to be out of order.

Next, the operation of the electromagnetic contactor will be described.
When the contact of the vacuum valve 1 is open, the mover 12 is pressed by the release spring 15 and is in contact with the stopper 16. When a closing command is issued to the electromagnetic contactor, the electromagnetic coil 18 is excited, a magnetic flux that circulates around the iron core 19, the yoke 20, and the mover 12 is generated, and an attractive force is generated in the electromagnetic magnet 13. Due to this attractive force, the mover 12 is attracted to the magnetic pole head 19a side and rotates clockwise in FIG. In conjunction with this, the open / close lever 8 pushes up the insulating rod 6 and the movable rod 1d via the contact pressure spring 7, and the movable contact 1b of the vacuum valve 1 contacts the fixed contact 1a. Further, the contact pressure spring 7 is compressed to a state as shown in FIG. Necessary contact pressure is applied to the contact points of the contact points 1a and 1b by the contact pressure of the contact pressure spring 7. After the completion of the insertion, the movable element 12 is attracted by the attractive force of the permanent magnet 21 and the charged state is maintained.

  In the shut-off operation, when the electromagnetic coil 19 is excited in the opposite direction to the turn-on command according to the shut-off command, a repulsive force that overcomes the attractive force of the permanent magnet 21 acts on the mover 12, and the force of the contact pressure spring 7 and the open spring 15 By the force pressing the lever 14, the pivot shaft 9 pivots counterclockwise in FIG. 1, the open / close lever 8 is pushed down, and the movable contact 1b is separated from the fixed contact 1a to be cut off. At this time, the movable element 12 is in contact with the stopper 16 so as not to rotate any further.

Next, the operation of the magnetic shielding plate 22 will be described.
In general, the electromagnetic contactor as in the present embodiment is used as an open / close switch of a power device, and is therefore opened and closed hundreds of thousands of times. It is difficult to make the gap completely zero between the mover 12 and the magnetic pole head 19a of the iron core 19 (the permanent magnet 21 when the permanent magnet 21 is provided), and there are some minute gaps. If this gap changes by repeated operations such as described above, the electromagnetic force also changes, and depending on the degree of change, the opening and closing will be hindered.

  FIG. 4 is a diagram schematically showing the relationship between the gap of the mover part in the magnetic circuit of the electromagnetic magnet and the electromagnetic force. For example, if the initial gap is 0.2 mm but is reduced to 0.1 mm due to wear of the contact portion surface due to a long-time opening / closing operation, the electromagnetic force changes by ΔF1. If the initial value is 0.5 mm but decreases to 0.4 mm, the electromagnetic force changes by ΔF2. Even when the gap reduction amount is the same 0.1 mm, the change amount of the electromagnetic force is ΔF1> ΔF2, and it can be seen that it varies greatly depending on the initial gap. Therefore, in order to reduce the amount of change in electromagnetic force, it is preferable that the initial gap is large. However, as the gap increases, the electromagnetic force naturally decreases.

  Therefore, the magnetic shielding plate 22 uses a non-magnetic member, and a magnetic gap with a value that does not significantly reduce the electromagnetic force is set in advance between the mover 12 and the magnetic pole head 19a (or the permanent magnet 21) of the iron core 19. It is for keeping. The magnetic gap between the mover 12 and the magnetic pole head 19a (or the permanent magnet 21) is kept almost constant due to the thickness of the magnetic shielding plate 22, and the dimensions are slightly reduced due to wear and the like by repeated opening and closing operations. However, the amount of change in electromagnetic force can be kept small. As described above, the thickness of the magnetic shielding plate 22 serving as the gap is, for example, about 0.26 mm.

  In addition, since the shock is applied to the magnetic shielding plate 22 by opening and closing many times as described above, wear and deformation are inevitably caused by long-term use. Therefore, the magnetic shielding plate 22 should be periodically replaced to maintain stable performance. Is desirable. In this embodiment, since the magnetic shielding plate 22 is detachable, when the magnetic shielding plate 22 is replaced, it can be easily removed by a procedure reverse to the attachment procedure of FIG. It is not necessary and can be easily replaced with a new one without using a tool or the like.

Furthermore, the outer diameter of the permanent magnet 21 is approximately the same as the outer diameter of the magnetic pole head 19a and is fitted to the inner diameter of the body of the bobbin 17. Of course, a slight gap is required for assembly, so after assembly, There are slight gaps. There is a risk that metal foreign matter, dust or the like may adhere to the gap or the surface of the permanent magnet 21. If a metallic foreign object, dust, etc. are attached, the above-mentioned “gap” will change.
In the present embodiment, the size of the magnetic shielding plate 22 is such that the outer diameter of the permanent magnet 21 (≈the magnetic pole head 19a) is hidden, so that the permanent magnet 21 is covered with the magnetic shielding plate 22, It is possible to suppress the adhesion of metallic foreign matter and dust. Further, since the magnetic shielding plate 22 covers a wide surface, it has excellent impact resistance and is less likely to be worn or deformed.

  In the above description, the permanent magnet 21 is used for holding the closing operation. However, after the closing, the current is continuously supplied to the electromagnetic coil 18 or the latching mechanism is used. There is also a method of holding the input, in which case the permanent magnet 21 is not required. Since there is no permanent magnet 21, the attachment of metal foreign matter is reduced, but the relationship between the gap between the magnetic pole head 19 a and the mover 12 is the same as above, and the same applies to the ingress of foreign matter and the attachment of dust to the surface. Can be expected.

As described above, according to the electromagnetic contactor of the first embodiment, the electromagnetic magnet that drives the main contact includes the electromagnetic coil wound around the bobbin having the flanges at both ends, and the bobbin that is inserted into the one end side. An iron core on which a magnetic pole head facing the mover is formed, and a yoke fixed to the other end of the iron core so as to surround the side of the electromagnetic coil, and a flange of the bobbin on the side of the magnetic pole head In addition , a shield plate is provided so as to cover the magnetic pole head, and the outer dimension of the shield plate is larger than the outer diameter dimension of the magnetic head on the surface covered by the shield plate. By using a shield plate with an area, deformation and wear are less likely to be caused by repeated impacts, and it is possible to suppress adhesion of metallic foreign matter, dust or the like to the gap between the bobbin and the iron core or the magnetic pole head.

  Further, the magnetic shielding plate is made of a rectangular plate material, and has a mounting hole in a folded curved surface formed on two opposing sides, and the mounting hole is engaged with a protrusion provided on a flange portion of the bobbin. Because it is detachably attached, the magnetic shield can be easily attached and detached without using a tightening member or tool, etc. Can provide.

  Furthermore, since a permanent magnet is provided between the magnetic pole head and the magnetic shielding plate to hold the charged state of the main contact, the permanent magnet portion has a configuration that does not require a special latch mechanism for holding and holding. It is possible to suppress the attachment of metal foreign matter to the metal, and to provide a highly reliable electromagnetic contactor.

Claims (3)

A vacuum valve having a built-in electromagnetic magnet, a flat plate-shaped movable element driven in the direction of the electromagnetic magnet by excitation of the electromagnetic magnet, and a pair of main contacts that are driven in conjunction with the movement of the movable element In an electromagnetic contactor with
The electromagnetic magnet includes an electromagnetic coil wound around a body of a bobbin having an axial center along the suction direction of the mover and having a flange on at least the suction side of the mover; and an axial direction of the bobbin is inserted is provided so as to surround a cylindrical core that the mover facing the pole head is formed on one end side, the both side portions of the fixed to the other end of the iron core Rutotomoni said electromagnetic coil And a yoke having a U-shaped cross section ,
On the flange portion of the bobbin on the side of the magnetic pole head, a magnetic shielding plate having an outer dimension larger than the outer diameter dimension of the magnetic pole head and covering the attraction surface of the magnetic pole head is provided.
In the position where the mover is attracted by the electromagnetic magnet, the surface of the mover faces the contact surface of the magnetic shielding plate substantially uniformly so that there is no gap, and the mover contacts the opening side end surface of the yoke. An electromagnetic contactor that is arranged in The electromagnetic contactor according to claim 1,
The magnetic shielding plate is made of a rectangular plate material, and mounting holes are provided on the bent curved surfaces formed on the two opposing sides, and the mounting holes are formed on the protrusions provided on the flange portion of the bobbin. An electromagnetic contactor that is engaged and detachably attached. The electromagnetic contactor according to claim 1 or 2,
An electromagnetic contactor characterized in that a permanent magnet is provided between the magnetic pole head and the magnetic shielding plate to maintain the charged state of the main contact.

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