JP2010123545A - Electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic relay having a pair of contacts for both-end cut, preventing formation of a conductive pathway on an insulation body. <P>SOLUTION: The electromagnetic relay 1 includes at least two pairs of contacts 20a for both-end cut, arranged side by side by separating from each other and formed of a fixed contact 22, and movable contact 21 driven by an electromagnet part 10 and switched. The two pairs of fixed contacts 22, 22 are fixed on the insulation body 30, and a shielding wall 40 structured by containing insulating material with a higher tracking voltage than the insulation body 30 is interposed between the two pairs of fixed contacts 22, 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement in an electromagnetic relay having at least two pairs of contact pairs for both ends.

  In this type of conventional electromagnetic relay, if the contacts are repeatedly opened and closed without causing welding or contact failure, the consumable powder may be scattered due to contact of the contacts, and the consumable powder may be scattered on the surface of the insulator. As a result of depositing and dampening on the surface, a conductive path may be generated on the surface of the insulator, and a so-called tracking phenomenon may occur in which two sets of fixed contacts fixed to the insulating body break down. Such a tracking phenomenon causes defects such as a short circuit between fixed contacts, and causes smoke and fire.

  As a countermeasure against such tracking failure, conventionally, a method has been adopted in which the number of opening and closing times guaranteed by the specifications is secured by forming partition walls and grooves on the body between the contacts to ensure the creepage distance. .

  FIG. 8 is a perspective view of a conventional electromagnetic relay in which a groove is formed in the body. In addition, this figure has shown the state which removed the cover.

  This electromagnetic relay 100 has an electromagnet part 110 in which a coil 112 is wound around a coil bobbin 111 and an iron core 113 is fitted in a through hole (not shown) of the coil bobbin 111, and is driven by the electromagnet part 110 to open and close. Two pairs of contact pairs 120 including a fixed contact 122 and a movable contact 121 are provided on the insulating body 130 so as to be separated from each other.

  When the electromagnet unit 110 is excited, the movable contacts 121 and 121 operate the armature 114 by the attractive force of the iron core 113 so that the movable contacts 121 and 121 come into contact with the fixed contacts 122 and 122 facing each other. Thus, the fixed contacts 122 are closed. On the other hand, when the power is not supplied, the movable contacts 121 and 121 and the fixed contacts 122 and 122 are separated from each other, and the two fixed contacts 122 and 122 are mounted on the insulating body 130 apart from each other. It is in an insulated state.

In FIG. 8, as a countermeasure against tracking failure, a vertical groove 131 is formed at an intermediate position of an insulating body 130 to which two sets of fixed contacts 122 and 122 are fixed. Therefore, the creepage distance can be secured in terms of specifications. In addition, since there is the vertical groove 131, even if consumable powder accumulates in the vertical groove 131 and its periphery, a conductive path is difficult to be generated. Moreover, the electromagnetic relay described in Patent Document 1 is provided with a partition between fixed contacts of a terminal block formed by another member having good arc resistance (heat resistance). It tries to prevent deterioration.
Japanese Utility Model Publication No. 48-12129

  In this way, in conventional electromagnetic relays, tracking defects were prevented by partition walls and grooves, but recently, the life of electronic and electrical equipment equipped with electromagnetic relays has been extended, so electromagnetic relays have more than Therefore, the formation of the partition walls and grooves as described above cannot be a sufficient measure, and there is a risk of causing troubles such as smoke and fire. In the electromagnetic relay described in Patent Document 1, the partition is formed by another member having good arc resistance. However, if the partition cannot withstand the accumulation of consumable powder on the contact, the insulation deterioration is effectively performed. It cannot be prevented. In addition, the electromagnetic relay described in this document is a multipole relay, and the actual situation is that almost no measures against insulation deterioration have been taken for a relay using a pair of contact points for both ends.

  The present invention has been proposed in view of such circumstances, and provides an electromagnetic relay that can prevent the formation of a conductive path in an insulating body in an electromagnetic relay having a pair of contact points for both ends. For the purpose.

  In order to achieve the above-described object, the electromagnetic relay according to claim 1 is provided with at least two pairs of two-way contact pairs formed of a fixed contact and a movable contact, which are opened and closed by being driven by an electromagnet part, separated from each other. In an electromagnetic relay, two sets of fixed contacts are fixed to an insulating body, and a shielding wall composed of an insulating material having a tracking voltage higher than that of the insulating body is interposed between the two sets of fixed contacts. It is characterized by that.

  In the electromagnetic relay according to claim 2, the movable contact is fixed to the movable contact plate operated by the electromagnet portion, and the shielding wall is in contact with the movable contact plate when the contact pair is worn, The structure is made to project toward the movable contact plate so as to prevent the contact of the movable contact.

  In the electromagnetic relay according to the third aspect, the insulating body has a recessed groove portion, and the shielding wall is formed by fitting and fixing another member containing an insulating material to the recessed groove portion.

  In the electromagnetic relay according to claim 4, a concave groove is further formed in the shielding wall.

  In the electromagnetic relay according to claim 5, a protrusion is further formed on the shielding wall.

  According to the electromagnetic relay of claim 1, since the shielding wall is formed on the insulating body between the two sets of fixed contacts, the creepage distance can be secured, and the shielding wall has a tracking voltage higher than that of the insulating body. Since it is made of a high insulating material, dielectric breakdown is unlikely to occur on the surface of the shielding wall, and it is possible to prevent smoke and fire of the device due to tracking failure.

  According to the electromagnetic relay of the second aspect, the shielding wall protrudes toward the movable contact side, and when the fixed contact and the movable contact are worn, the contact between the fixed contact and the movable contact is prevented. When the number of times of opening and closing increases and contact wear increases, the contact between the fixed contact and the movable contact is blocked, and the contact becomes a contact failure, so that burnout of the device can be prevented.

  According to the electromagnetic relay of the third aspect, since the shielding wall is formed by fitting and fixing another member to the concave groove portion formed in the insulating body, it can be manufactured easily. Moreover, since it is the structure which fits another member, in order to make creepage distance long, the insulation body which is a conventional product which provided the recessed groove part can be used effectively.

  According to the electromagnetic relay of the fifth aspect, since the concave wall is further formed in the shielding wall, the creepage distance can be increased to further reduce the possibility of dielectric breakdown on the surface of the insulating body.

  According to the electromagnetic relay of the fourth aspect, since the protruding portion is further formed on the shielding wall, the creepage distance can be increased to further reduce the possibility of dielectric breakdown on the surface of the insulating body. .

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a perspective view of an electromagnetic relay showing a first embodiment of the present invention. FIG. 2 is an explanatory view of the main part of the electromagnetic relay, FIG. 2 (a) is a schematic perspective view of the main part, FIG. 2 (b) is a schematic vertical sectional view of the main part, and FIG. 2 (c) is the position of the main part. It is a schematic side view which shows a relationship. FIG. 3 is an exploded perspective view of the electromagnetic relay. 1 and 2 show a state in which a cover covering the electromagnet and the like is removed.

  The electromagnetic relay 1 includes an electromagnet unit 10 that performs contact / separation of contacts by energizing and stopping energization of a coil 12 on an insulating body 30 made of resin, and a contact pair including a movable contact 21 and a fixed contact 22. 20a (refer to FIG. 2 and FIG. 3) is provided, and a cover 2 whose lower surface is opened is put on them.

  The insulating body 30 is provided with an approximately U-shaped insulating wall 31 in a plan view at an approximately central portion, and an electromagnet accommodating portion 34 for accommodating the electromagnet portion 10 is formed on the rear side of the insulating wall 31 in FIG. On the other hand, a contact accommodating portion 33 for disposing the contact portion 20 is formed on the front side. The insulating wall 31 has a function of blocking the electromagnet portion 30 and the contact portion 20.

  The electromagnet unit 10 includes a yoke 14, a coil block 11, an iron core 15, an armature 16, and a hinge spring 17.

  The yoke 14 is bent in a substantially L shape, and the coil block 11 formed by winding the coil 12 around the coil bobbin 13 is placed on the bottom plate 14 a of the yoke 14. The coil 12 is connected to a coil terminal 18 that is implanted in the insulating body 30. The iron core 15 has a shape including a trunk portion 15b and a bowl-shaped suction piece 15a arranged at the head thereof, and the trunk portion 15b is passed through the through hole 13a of the coil bobbin 13 so that the bottom plate 14a of the yoke 14 is formed. It is fixed to the mounting hole 14b.

  The armature 16 includes a magnetic pole piece 16a, an insulating portion 16b, and a fixed piece 16c. When viewed from the side, the magnetic pole piece 16a is bent in a substantially horizontal direction at the top, and is formed in an inverted L shape. The sandwiching piece 14c that is arranged and protrudes from both sides of the upper end of the yoke 14 engages with a notch recess 16d formed on both sides of the magnetic pole piece 16a and is supported in a swingable manner. The magnetic pole piece 16 a of the armature 16 is disposed at a position facing the attracting piece 15 a of the iron core 15.

  The hinge spring 17 is interposed between the armature 16 and the yoke 14, and a spring piece 17 a that presses the upper portion of the insulating portion 16 b of the armature 16 is formed on the upper portion. With the pressing force of the spring piece 17a, the state in which the magnetic pole piece 16a of the armature 16 is separated from the attracting piece 15a of the iron core 15 is maintained when the coil 12 is not energized. Further, when the coil 12 is energized, the magnetic force of the attracting piece 15 a of the iron core 15 exceeds the pressing force of the spring piece 17 a, and the magnetic pole piece 16 a of the armature 16 contacts the attracting piece 15 a of the iron core 15.

  The contact portion 20 that is switched according to the operation of the electromagnet portion 10 includes a movable contact plate 23 having two sets of movable contacts 21 and 21 fixed to both ends, and the movable contact plate 23 connected to the armature 16. Two fixed springs 24 attached to the movable spring 24 connected to the fixed piece 16c suspended from the central lower end of the insulating portion 16b and the contact housing portion 33 of the insulating body 30 and fixed to the fixed contacts 22, 22 one by one. It comprises contact plates 25, 25.

  More specifically, in the contact storage portion 33, two sets of fixed contacts 22 and 22 are spaced apart from the inner wall 33 a on the front side of the contact storage portion 33 of the insulating body 30, while the two sets of movable contacts 21 and 21. Are arranged in front of the wall surface of the insulating wall 31 at positions facing the two sets of fixed contacts 22, 22.

  The fixed contact plates 25 and 25 to which the fixed contacts 22 and 22 are fixed are stored and fixed in a contact storage recess 33a formed on the contact storage portion 33 side of the front wall 32 of the insulating body 30, and the lower end thereof is a contact. It penetrates through a mounting hole (not shown) provided in the bottom of the storage recess 33a and protrudes to a connection part 36 formed outside the insulating body 30 so as to be connected.

  Two sets of contact pairs 20a and 20a composed of the fixed contacts 22 and 22 and the movable contacts 21 and 21 are so-called two-way contact pairs in which the contact pairs 20a and 20a operate simultaneously to open and close one circuit. It is configured as.

  Therefore, the two sets of fixed contacts 22, 22 have a predetermined creepage distance as described above so that the two sets of fixed contacts 22, 22 can maintain an insulating state when the electromagnet portion 10 is in a non-excited state. The insulating body 30 is spaced apart.

  Furthermore, in this embodiment, the shielding wall 40 which protrudes from the inner wall surface of the front wall 32 of the insulating body 30 to the movable contact plate 23 side is formed at a substantially intermediate position between the two contact housing recesses 33a. The shielding wall 40 also protrudes from the upper end surface of the front wall 32.

  The shielding wall 40 is formed by fitting and fixing an insulating member 41, which is a separate member from the insulating body 30, to a recessed groove portion 35 formed continuously from the inner wall surface to the inner bottom surface of the front wall 32 of the insulating body 30. Has been. As the insulating member 41, a material having a higher tracking voltage than the resin forming the insulating body 30 is used. For example, an organic material such as melamine phenol or unsaturated polyester resin, and an inorganic material including ceramics or glass are used. used.

  These materials are such that conductive paths (tracks) are not easily generated on the surface even by repeated discharges. Specifically, this is a voltage based on a comparative tracking index (CTI) that causes breakdown due to a CTI test. It is desirable that the tracking voltage is 175 volts or more.

  The resin material used for the insulating body 30 is preferably a material having high mechanical strength for fixing and supporting the fixed contacts 22 and 22, and a material having a tracking voltage lower than 175 volts.

  As described above, the shielding wall 40 made of a material having a tracking voltage higher than that of the material of the insulating body 30 is formed along the direction of shielding the two sets of fixed contacts 22 and 22. In addition to ensuring the creepage distance, the surface of the insulating wall 40 can be easily formed even when the consumable powder scatters due to repeated opening and closing of the contacts and the consumable powder accumulates between the fixed contacts 22 and 22 on the insulating body 30. Insulation breakdown is prevented and smoke and ignition can be prevented in advance.

  Further, as shown in FIG. 2, a part of the projecting end surface 40a of the shielding wall 40 protruding toward the contact accommodating part 33 (the center part of the movable contact plate 23) is movable with the movable contacts 21 and 21 attached to both ends. The contact plate 23 faces the substantially central position, and the distance L1 when the electromagnet portion 10 is not excited is set to be slightly larger than the distance L2 between the movable contact 21 and the fixed contact 22. . Therefore, when the number of times the electromagnetic relay 1 is opened and closed increases and the amount of wear on the contact surfaces of the movable contacts 21 and 21 and the fixed contacts 22 and 22 increases, the distance L2 between the movable contact 21 and the fixed contact 22 becomes the movable contact. Since it becomes longer than the distance L2 between the plate 23 and the protruding end surface 40a of the shielding wall 40, the movable contact plate 23 and the shield are shielded before the contact of the contact pair 20a by excitation of the electromagnet portion 10 (contact contact operation). The protruding end surface 40a of the wall 40 can be brought into contact. That is, by adjusting the distances L1 and L2, a contact failure of the contact pair 20a can be generated before dielectric breakdown, and a failure that leads to burnout can be prevented.

  Such a shielding wall 40 containing a material having a high tracking voltage may not be configured by fitting the insulating member 41 which is a separate member to the insulating body 30, or may be formed integrally with the insulating body 30. Good. In that case, only a portion protruding from the upper end surface and the inner wall surface of the front wall 32 of the insulating body 30 may be made of a material different from that of the insulating body 30. When two types of resins are integrally formed with a mold, there is a possibility that a constant boundary may not be obtained, but it is desirable that at least the entire shielding wall 40 be formed of a material having a high tracking voltage.

  Moreover, in this embodiment, although the ditch | groove part 35 for fitting the insulating member 41 to the inner wall face and inner bottom face which faces the contact accommodating part 33 is provided, it has the ditch | groove part as a deposit part of consumable powder. Insulating bodies may be used. That is, if an insulating member is prepared so as to match a conventionally used insulating body, the conventional product can be used effectively, and an electromagnetic relay that is easy, low cost, and resistant to tracking failure can be formed.

  It is desirable that the insulating member 41 is firmly fixed to the concave groove portion 35 not only by fitting but also firmly by heat welding or adhesion.

  Next, the contact operation of the electromagnetic relay 1 shown in the present embodiment will be described with reference to FIG. 4A is a longitudinal sectional view of the electromagnetic relay 1 showing a state when the electromagnet portion 10 is not excited, and FIG. 4B is a longitudinal sectional view of the electromagnetic relay 1 showing a state when the electromagnet portion 10 is excited. is there.

  As described above, in the electromagnetic relay 1, when the electromagnet portion 10 is in a non-excited state, the spring piece 17 a of the hinge spring 17 presses the upper surface of the insulating portion 16 b of the armature 16. 2 is rotated in the clockwise direction in FIG. 2, and the magnetic pole piece 16 a of the armature 16 is separated from the attracting piece 15 a of the iron core 15. In this state, as shown in FIG. 4A, the two sets of the movable contacts 21 and 21 and the fixed contacts 22 and 22 are separated.

  Then, when the coil 12 is energized to excite the electromagnet unit 10, a magnetic force is generated that attracts the magnetic pole piece 16 a of the armature 16 to the attracting piece 15 a of the iron core 15 through the yoke 14, the iron core 15, and the armature 16. The magnetic pole piece 16 a of the armature 16 is attracted to the suction piece 15 a of the iron core 15 against the spring force (pressing force) of the hinge spring 17. At this time, the armature 16 is rotated in the counterclockwise direction in FIG. 2, and the movable contact plate 23 is also moved in the counterclockwise direction, and the two sets of the movable contacts 21 and 21 are fixed to each other. Contact the contacts 22, 22.

  When the contacts are configured in this way, the current is opened and closed by a contact pair that is closed later or opened earlier, and consumable powder is likely to be generated by the contact pair. Since the contact plate 23 is moved simultaneously by the armature 16, it cannot be specified which of the two contact pairs 20 a, 20 a comes in contact with or separated first. Therefore, as shown in the present embodiment, the shielding wall 40 is preferably formed at a substantially central position between the fixed contacts 22 and 22.

  FIG. 6 is a perspective view of an electromagnetic relay showing a second embodiment of the present invention. FIG. 7A is an enlarged plan view of a main part of the electromagnetic relay, and FIG. 7B is an enlarged plan view of a main part of another example.

  In the electromagnetic relay 1, the shielding wall 40A is formed of an insulating member 42 having a tracking voltage higher than that of the insulating body 30, and is adhered to the inner wall surface of the insulating body 30, as shown in FIGS. 6 and 7A. A concave groove 42a that runs in the vertical direction is formed on the surface of the insulating member 42 on the contact accommodating portion 33 side, and protruding ridges 42b and 42b that protrude toward the two fixed contact sides are also formed. Note that both end portions of the shielding wall 40A provided with the ridges 42b and 42b constitute side walls of the contact housing recess 33a that houses the fixed contact.

  Thus, since the concave groove 42a is formed on the surface of the shielding wall 40 along the direction of shielding the two sets of fixed contacts 22, 22, the concave groove 42a is consumed due to opening and closing of the contact pair 20a, 20a. It can be a powder accumulation part, and since the protruding strips 42b and 42b are formed, it is possible to prevent the expendable powder from scattering toward the other fixed contact. And it becomes difficult to form an electroconductive path | route combined with the effect of the insulating member 41 by the material which is hard to carry out a dielectric breakdown. Of course, the creeping distance can be further increased by the concave grooves 42a and the ridges 42b and 42b.

  Further, as shown in FIG. 7B, a shielding wall 40B in which a convex strip portion 42c is formed on the surface on the movable contact side may be provided. This also ensures a sufficient creepage distance between the contacts and increases the surface area of the consumable powder deposit, making it difficult to form a conductive path.

  Similarly to the first embodiment, the shielding wall 40 shown in the present embodiment may be formed integrally with the insulating body. When the insulating wall 41 is constituted by the insulating member 41, the shielding wall 40 is firmly attached by heat fitting, adhesion, or the like. It is desirable to fix to.

  Since the other components and contact operations of the electromagnetic relay 1 shown in the present embodiment are the same as those in the first embodiment, the same reference numerals are given to the other components and their description is omitted. .

  In the first and second embodiments described above, an a-contact type in which the contact is open when the electromagnet portion 10 is in the non-excited state is illustrated, but the present invention provides a contact when the electromagnet portion is in the non-excited state. It can also be applied to the b contact type in which the contact is made and the c contact type in which the contact is switched by switching the current to the coil.

It is a perspective view of the electromagnetic relay which shows the 1st Embodiment of this invention. (A) is the principal part expansion perspective view of the same electromagnetic relay, (b) is the principal part longitudinal cross-sectional view, (c) is a schematic side view which shows the positional relationship of the principal part. It is a disassembled perspective view of the same electromagnetic relay. It is a longitudinal cross-sectional view of the same electromagnetic relay which shows the state at the time of the non-excitation of an electromagnet part. It is a longitudinal cross-sectional view of the same electromagnetic relay which shows the state at the time of the excitation of an electromagnet part. It is a perspective view of the electromagnetic relay which shows the 2nd Embodiment of this invention. (A) is a principal part cross-sectional view of the same electromagnetic relay, (b) is a principal part cross-sectional view showing another example. It is a perspective view of the conventional electromagnetic relay.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic relay 10 Electromagnet part 20 Contact part 21 Movable contact 22 Fixed contact 23 Movable contact board 24 Movable spring 25 Fixed contact board 30 Insulating body 32 Front wall 35 Groove part 40, 40A, 40B Shielding wall 41, 42 Insulating member (separate member) )
42a Concave groove 42b, 42c Convex section

Claims (5)

In an electromagnetic relay that is opened and closed by being driven by an electromagnet part, at least two pairs of contact pairs for both cutting made up of a fixed contact and a movable contact, separated from each other,
The two sets of fixed contacts are fixed to the insulating body,
An electromagnetic relay characterized in that a shielding wall configured to include an insulating material having a tracking voltage higher than that of the insulating body is interposed between the two sets of fixed contacts. In claim 1,
The movable contact is fixed to a movable contact plate operated by the electromagnet part,
The shielding wall has a structure that protrudes toward the movable contact plate so as to abut against the movable contact plate when the contact pair is worn and to prevent contact between the fixed contact and the movable contact. Electromagnetic relay. In claim 1 or 2,
A concave groove is formed in the insulating body,
The shield wall is an electromagnetic relay formed by fitting and fixing another member containing the insulating material in the concave groove. In any one of Claims 1-3,
An electromagnetic relay in which a concave groove is further formed in the shielding wall. In any one of Claims 1-3,
An electromagnetic relay in which a protrusion is further formed on the shielding wall.

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