Patent Grant
8289111
The present application is National Phase of International Application No. PCT/JP2010/003931 filed Jun. 14, 2010, and claims priority from, Japanese Application No. 2009-190581 filed Aug. 20, 2009, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present invention relates to an electromagnetic contactor wherein a contact mechanism is made movable using a polarized electromagnet.
As this kind of electromagnetic contactor, a conventional electromagnetic contactor includes: a case, an electromagnetic device having a fixed iron core penetrating a coil frame on which a coil is wound and a movable iron core opposing the fixed iron core so as to be connectable and detachable, a contact-equipped movable frame disposed in parallel with the electromagnetic device, spring-urged in a return direction, and moving in parallel with the movable iron core, and an interlocking lever that links the movable iron core and movable frame, wherein a spring that urges the movable iron core in a pole open direction in a condition in which the movable iron core is adsorbed to the fixed iron core without contacting in a condition in which the movable iron core is not adsorbed to the fixed iron core, is provided on the coil frame (for example, refer to Patent Document 1).
However, in the heretofore known example described in Patent Document 1, the contact-equipped movable frame is spring-urged in the return direction by a return spring. The contact-equipped movable frame is returned by the return spring when the electromagnetic device is in a non-energized condition and, by putting the electromagnetic device into an energized condition during this condition and adsorbing the movable iron core to the fixed iron core, the contact-equipped movable frame is made movable against the return spring via the interlocking lever along with the movement of the movable iron core. However, a movement in a direction opposite to the return direction of the contact-equipped movable frame is carried out by the force of adsorption of the movable iron core to the fixed iron core arising from the energization of the electromagnetic device. The contact-equipped movable frame returns up to a predetermined distance in the return direction under a combined spring force of the spring force of the return spring added to the spring force of the spring provided in the electromagnetic device, and in the end, the contact-equipped movable frame is returned to the pole open position by the spring force of the return spring.
In this case, in order to reliably return the contact movable frame to the pole open position, increasing the spring force of the return spring is necessary, and in this case, it is also necessary to increase the electromagnetic adsorption force of the electromagnetic device, meaning that there is an unsolved problem such that the configuration of the whole increases in size. In particular, as the contacts are provided urging in the contact direction by pressing springs in the contact-equipped movable frame, there is no problem when there is no b contact when the contact-equipped movable frame returns to the pole open position, but when there are a large number of b contacts, there is no option other than to increase the spring force of the return spring.
In the case of a direct current electromagnet, wherein there are a large number of b contacts making contact when the contact-equipped movable frame returns to the pole open position in this way, the relationship between the suction force and the load (the contact load) must be made such that input is applied at the suction force at a time of an optional input voltage Von, and the return to the pole open position of the release is possible at the suction force at a time of a release voltage Voff. Consequently, as shown by a polygonal line characteristic line L0 in
Therefore, bearing in mind the unsolved problems of the heretofore known example, the invention provides an electromagnetic contactor that can enable a reliable return to the pole open position without increasing the spring force of the return spring.
In order to achieve the heretofore described object, in an electromagnetic contactor according to one aspect of the invention wherein an electromagnetic device having an exciting coil and a contact mechanism of a return spring are disposed in parallel, and the electromagnetic device and contact mechanism are linked by a drive lever, wherein the electromagnetic device comprises a polarized electromagnet including a magnetic circuit with a permanent magnet generating a suction force. When the exciting coil is not energized, the permanent magnet moves the contact mechanism to a pole open position side, the drive lever is fixed to either one of the electromagnetic device or contact mechanism, and is brought into contact with the other with no gap at least when the contact mechanism is moved to the pole open position side, and the return force of the contact mechanism in the vicinity of the pole open position is covered by the suction force of the permanent magnet.
According to this configuration, when returning the contact mechanism to the pole open position, the return to the pole open position is started by the spring force of the return spring when starting the return, and in the end, the contact mechanism is returned to the pole open position by using the suction force of the permanent magnet, which means that the return to the pole open position can be reliably carried out and also, it is possible to reduce the spring force of the return spring.
Also, the electromagnetic contactor according to another aspect of the invention is characterized in that the drive lever is fixed to the electromagnetic device, and the free end of the drive lever is brought into contact with a movable contact support urged to the pole open position side by the return spring configuring the contact mechanism with no gap in either direction in which the movable contact support can move.
According to this configuration, as the drive lever is fixed to either one of the electromagnetic device or contact mechanism, and the free end of the drive lever is brought into contact with the other of the electromagnetic device or contact mechanism, with no gap in either direction in which the movable contact support can move, it is possible to reliably transmit a drive force caused by the suction force of the permanent magnet of the electromagnetic device to the movable contact support via the drive lever.
Furthermore, in the electromagnetic contactor according to another aspect of the invention, the drive lever is fixed to the electromagnetic device, and an arc portion that contacts with the end surface of the movable contact support on the side opposite to that of the return spring is formed in the free end thereof, distanced a predetermined distance inward from the leading end. A lever retainer portion formed on the movable contact support contacts with the side opposite to the end surface of the outer side leading end portion of the arc portion.
According to this configuration, as the free end of the drive lever is inserted between and supported by the end face of the movable contact support and the lever retainer portion, it is possible to reliably bring the drive lever and movable contact support into contact with no gap in either direction in which the movable contact support can move.
Further still, the electromagnetic contactor according to another aspect of the invention is characterized in that the lever retainer portion is flexible, and presses against the drive lever.
According to this configuration, as the lever retainer portion is flexible, and presses against the drive lever, it is possible to support the free end of the drive lever while applying a predetermined contact pressure, to prevent a gap from occurring, and to maintain the position without any rattling.
According to the invention, in an electromagnetic contactor in which an electromagnetic device having an exciting coil and a contact mechanism having a return spring are disposed in parallel, and the electromagnetic device and contact mechanism are linked by a drive lever, the drive lever is fixed to either one of the electromagnetic device or contact mechanism, and contacts with the other with no gap at least when the contact mechanism is moved to the pole open position side, and the return force of the contact mechanism in the vicinity of the pole open position is covered by the suction force of the permanent magnet. Therefore, it is possible to reliably carry out the return to the pole open position, because the spring force of the return spring is unnecessary in the vicinity of the pole open position, advantages are obtained in that it is possible to reduce the spring force of the return spring by this amount, to reduce the electromagnetic force generated in the electromagnetic device, and to downsize the configuration of the whole.
Hereafter, a description will be given based on the drawings of an embodiment of the invention.
In
The polarized electromagnet 4, as shown in
The right flange portion 14 has a rectangular coil retainer plate 14a that restricts an end portion of the exciting coil 10, and a rectangular frame-like armature housing portion 14b attached to the outer side of the coil retainer plate 14a by the outer peripheral side thereof. Yoke holding portions 14c in which are inserted and held end plate portions 21b of exterior yokes 21, to be described hereafter, and coil terminal portions 14d and 14e in which are tied coil start and coil finish end portions of the exciting coil 10, are formed on the armature housing portion 14b.
Then, the exciting coil 10 is wound between the cylindrical portion 12 of the spool 11 and the coil retainer plates 13a, 14a of the left and right flange portions 13, 14, as shown in
Also, a plunger 15 held movably inside penetrates the cylindrical portion 12 of the spool 11. A first armature 16 is fixed in the corresponding end portion inside the armature housing portion 14b formed in the right flange portion 14 of the spool 11 at the right end of the plunger 15. Also, a second armature 17 is fixed in the corresponding position inside the armature housing portion 13b formed in the left flange portion 13 of the spool at the left end of the plunger 15, and a non-magnetic plate 18 is disposed on the outer side of the second armature 17. Then, a drive lever 19 linked to a movable contact support 37 of a movable contact portion 35 of the contact mechanism 5, which drives the movable contact support 37 in left and right directions, is disposed on the upper surface of the first armature 16. The drive lever 19 is integrally formed on the upper surface of the first armature 16 in a square rod form as shown enlarged in
Furthermore, an axisymmetrical front and back pair of exterior yokes 21 sandwiching the spool 11, guided into and fixed inside a housing portion 2a formed in the lower case 2, are disposed in the right flange portion 14 of the spool 11. Also, an axisymmetrical front and back pair of interior yokes 22 sandwiching the spool 11, maintaining a predetermined distance from the exterior yokes 21, are disposed in the left flange portion 13 of the spool 11.
The exterior yoke 21, as is particularly clear in
Meanwhile, the interior yoke 22, as is particularly clear in
Also, the first armature 16 is disposed on the outer side of the right end plate portion 21b, of the exterior yoke 21, and the second armature 17 is disposed between the left end plate portion 21a of the exterior yoke 21 and the second opposing plate portions 22d and 22e of the interior yoke 22.
Furthermore, a permanent magnet 24 is disposed between the flat plate portion 21d of the exterior yoke 21 and the first opposing plate portion 22a of the interior yoke 22.
The contact mechanism 5, as shown in
Each of the main circuit terminal portions 33 has main circuit terminals 33a to 33d, as shown in
Then, the movable contact portion 35 is disposed slidably in the left-right direction in the movable contact housing portion 32. The movable contact portion 35 has the movable contact support 37, which are formed with partition walls 36 maintaining predetermined intervals made of a synthetic resin material, and movable contacts 38a to 38d supported by the partition walls 36 of the movable contact support 37. Herein, the movable contacts 38a, 38b oppose the fixed contacts TNO of the main circuit terminals 33a, 33b respectively, and are urged by contact springs 39 in a direction away from the partition walls 36 to the left. Also, the movable contacts 38c, 38d oppose the fixed contacts TNC of the main circuit terminals 33c, 33d respectively, and are urged by contact springs 40 in a direction away from the partition walls 36 to the right.
Then, the movable contact support 37 is urged to the right by a return spring 41. The return spring 41 disposed in such a way that one end penetrates a left end plate portion 37a and contacts with the partition wall 36, and the other end contacts with the upper case side wall interior surface, is set to attain a free length in the vicinity of a pole open position at which is attained a condition wherein the movable contacts 38c, 38d formed on the movable contact support 37 contact with the fixed contacts TNC, and are pressed with a predetermined pressure by the contact springs 40.
Also, a linking portion 42, which is linked to the drive lever 19 formed on the first armature 16 of the polarized electromagnet 4, is formed on the right end of the movable contact support 37. As shown in
Consequently, when the upper case 3 holding the contact mechanism 5 is attached to the lower case 2 holding the polarized electromagnet 4, the drive lever 19 and movable contact support 37 are linked. The linking of the drive lever 19 is carried out by inserting the drive lever 19 from below into a lever housing space surrounded by the right end surface of the right end plate portion 43 of the movable contact support 37, the pair of support plate portions 44, and the lever retainer portion 46. When inserting the drive lever 19 from below into the lever housing space in this way, the apex of the curved bulging portion 19a of the drive lever 19 contacts with the right end surface of the right end plate portion 43, the lever retainer portion 46 presses against the right end surface of the upper end side vertical rod portion 19b, and the drive lever 19 is press-fitted and tightly held without leaving any gap in the left-right direction, that is, in either direction in which the movable contact support 37 can move.
Next, a description will be given of actions of the heretofore described embodiment.
Now, in a condition in which the coil terminal portions 14d and 14e are not energized, the exciting coil 10 is in a non-excited condition, and no drive force to drive the plunger 15 is emitted. However, in the contact mechanism 5, the movable contact support 37 is urged to the right by the return spring 41. Therefore, the movable contact support 37 with the movable contacts 38c, 38d thereof contacting with the fixed contacts TNC further compresses the contact springs 40. At this time, the return spring 41 is set in such a way that the return spring 41 attains a free length in the vicinity of a pole open position which will attain a condition wherein the movable contact support 37 moves to the right, compressing the contact springs 40, and the movable contacts 38c, 38d contacts with the fixed contacts TNC with a predetermined pressure. For this reason, until the movable contact support 37 moves to the right because of the return spring 41, the movable contacts 38c, 38d contacts with the fixed contacts TNC, and the two contact springs 40 are compressed, the movable contact support 37 is moved smoothly to the right by the spring load of the return spring 41. However, as shown in
Meanwhile, at the polarized electromagnet 4, by the magnetic force of the permanent magnet 24 being transmitted to the second opposing plate portions 22d and 22e via the interior yoke 22, the second armature 17 is suctioned by the second opposing plate portions 22d, 22e either immediately before the compression of the contact springs 40 by the return spring 41 becomes impossible, or before that, before the pole open position. As a result of this, the return force of a lightly shaded region 47 of
From the condition in which the movable contact portion 35 of the contact mechanism 5 is in the pole open position, the exciting coil 10 is excited to an opposite polarity of the permanent magnet 24 by energizing the coil terminal portions 14d, 14e. Because of this, a suction force acts between the left and right armatures 17, 16 and the left and right end plate portions 21a, 21b of the exterior yoke 21. At the same time as this, a repulsion force acts between the left side armature 17 and the second opposing plate portions 22d, 22e of the interior yoke 22. Because of this, the plunger 15 moves to the left against the spring force of the return spring 41, and the armatures 17, 16 are adsorbed to the left and right end plate portions 21a, 21b of the exterior yoke 21. Because of this, the movable contact support 37 of the movable contact portion 35 moves to the left against the return spring 41 via the drive lever 19 of the first armature 16, and attains a pole closed position at which the movable contacts 38a, 38b contact with the fixed contacts TNO of the main circuit terminals 33a, 33b with a predetermined pressing force of the contact springs 39. By the movable contact support 37 moving to the left, the movable contacts 38c and 38d are detached from the fixed contacts TNC of the main circuit terminals 33c and 33d.
Also, when the energization of the coil terminal portions 14d and 14e is stopped in the condition in which the contact mechanism 5 is in the pole closed position, the exciting coil 10 returns to the non-excited condition, the second armature 17 is suctioned by the pressing force of the return spring 41 and the suction force of the second opposing plate portions 22d and 22e of the interior yoke 22 caused by the permanent magnet 24, and the movable contact support 37 of the movable contact portion 35 returns to the heretofore described pole open position.
At this time, with the polarized electromagnet 4, a magnetic flux from the permanent magnet 24 is such that, for example, the interior yoke 22 side is the N pole and the exterior yoke 21 side is the S pole, a flux path is formed wherein a magnetic flux emitted from the N pole reaches the second opposing plate portions 22d and 22e, via the bent portions 22b and 22c, from the first opposing plate portion 22a of the interior yoke 22, passes from the second opposing plate portions 22d and 22e through the left end plate portion 21a, inclined plate portion 21e, and flat plate portion 21d of the exterior yoke 21, and reaches the S pole of the permanent magnet 24.
At this time, as shown in
Moreover, as the second opposing plate portions 22d, 22e of the interior yoke 22 are linked to the first opposing plate portion 22a, which contacts with the permanent magnet 24, via the bent portions 22b and 22c, it is possible to dispose the bent portions 22b, 22c utilizing the dead space at the four corners on the outer peripheral side of the cylindrical exciting coil 10, as shown in
As heretofore described, in the embodiment, as the spring load of the return spring 41 in the vicinity of the pole open position is kept to a low value, and the force compressing the contact springs 40 is covered by the suction force of the permanent magnet 24, for example, the relationship between the stroke and spring load of the movable contact support 37 when connecting an auxiliary contact having four b contacts to the heretofore described configuration, making the contacts 2a2b+4b, is as a characteristic line L10 indicated by the polygonal line in
In
Incidentally, in a heretofore known configuration, wherein a linking plate portion 45 and lever retainer portion 46 in a linking portion 42 of a movable contact support 37 are omitted, and the return of the movable contact support 37 to the pole open position is covered by a return spring 41 alone without utilizing the suction force of a permanent magnet 24, it is necessary to set the spring load of the return spring 41 at strokes point A and point B to a value exceeding the spring load of contact springs for b contacts as shown in
For this reason, when making the contact configuration 2a2b+4b, the relationship between the stroke and spring load is as shown by a polygonal line characteristic line L0 in the heretofore described
In response to this, in the embodiment, as the spring force of the return spring 41 is reduced by utilizing the suction force of the permanent magnet 24, as heretofore described, the spring load represented by the characteristic line L10 does not exceed the suction force represented by the input suction characteristic curve L11. Therefore, it is possible to keep the spring load sufficiently lower than the suction force of the input suction characteristic curve L11, as shown in
In the heretofore described embodiment, a description is given of a case in which the exterior yoke 21 configuring the polarized electromagnet 4 such that the linking plate portion 21c linking the left and right end plate portions 21a and 21b is configured of the flat plate portion 21d and inclined plate portion 21e, but not being limited to this, it is possible to apply an exterior yoke with an optional configuration, and in the case of the polarized electromagnet itself, it is also possible to apply a polarized electromagnet with an optional configuration.
Also, in the heretofore described embodiment, a description is given of a case in which the drive lever 19 is press-fitted and tightly held in the linking portion 42 of the movable contact support 37, but not being limited to this, the lever retainer portion 46 of the linking portion 42 may be omitted, an engagement portion that contacts with the right end surface of the drive lever 19 is formed on the linking portion 42 in such a way that at least the suction force of the permanent magnet 24 is transmitted to the movable contact support 37, and the drive lever 19 contacts and held by the linking portion 42 with no gap.
Also, in the heretofore described embodiment, a description is given of a case in which the movable contact portion 35 has two of the each, open contacts and closed contacts, but not being limited to this, it is possible to adopt a three phase, four line type of R-phase, S-phase, T-phase, or N-phase contact configuration, or another optional contact configuration.
According to the invention, when returning the contact mechanism to the pole open position, the return to the pole open position is started by the spring force of the return spring when starting the return, and in the end, the contact mechanism is also returned to the pole open position by using the suction force of the permanent magnet. Therefore, the return to the pole open position can be reliably carried out, and it is possible to provide an electromagnetic contactor, which reduces the spring force of the return spring.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-190581 | Aug 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/003931 | 6/14/2010 | WO | 00 | 9/15/2011 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2011/021329 | 2/24/2011 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20120133462 A1 | May 2012 | US |
