JP2010114005A - Heater structure of thermal type overload relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heater structure of a thermal type overload relay having no risk of increasing a complicated manufacturing process and capable of being simply applied to a conventional thermal type overload relay and capable of superbly suppressing thermal interference of thermally-actuated elements in each of phases. <P>SOLUTION: The heater structure 10 of a thermal type overload relay including a plurality of heat elements, arranged in right and left in parallel, in which a heater wire 13 of which the one end is connected with a main terminal 16 of a main circuit and the other end is connected with a bimetal 11 is arranged so as to be wound around the bimetal 11, opens and closes a contact using deformation of the bimetal 11. The heater structure is provided with an insulation tube 20 made of an insulative material and moreover covering the heat elements in a state that at least one of each neighboring heat elements is inserted relatively into an hollow part 21. The insulative tube 20 has flexibility and moreover is made of preferably the same insulative material as the insulative tape 12 covering a periphery of the bimetal 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heater structure for a thermal overload relay, and more specifically, for example, applied to a circuit breaker or a magnetic contactor, etc., such as a motor by opening and closing a contact using a bimetal deformation. The present invention relates to a heater structure of a thermal overload relay that performs overcurrent protection and phase loss protection.

  2. Description of the Related Art Conventionally, as a thermal overload relay that is applied to, for example, a circuit breaker or an electromagnetic contactor and opens and closes a contact using a deformation of a bimetal, one having a heater structure inside a case body is known. . The heater structure includes a plurality of heat elements arranged in parallel on the left and right.

  The heat element is a thermally responsive element corresponding to each of the R, S, and T phases of the main circuit. This heat element is provided corresponding to each phase of R, S, and T of the main circuit and has a strip-shaped bimetal with an insulating tape attached to the side surface, one end connected to the main circuit, the other The end of the bimetal is connected to the bimetal, and is provided with a heater wire arranged so as to wind the bimetal. The main circuit current is passed through and the bimetal is bent and deformed by the generated heat.

  In recent years, there has been a demand for miniaturization of a thermal overload relay having such a heater structure, and heat elements that are adjacent to each other even in a heat element that is provided in a side-by-side manner with the miniaturization of the case body. The separation distance from is small. Therefore, there is a possibility that thermal interference occurs in the heat element between the phases. In view of this, a heater structure for a thermal overload relay having a heat element whose periphery is covered with a heat-resistant coating layer has been proposed (see, for example, Patent Document 1).

JP 2006-73405 A

  However, in the heater structure of the thermal overload relay as described above, since the periphery of the heat element is covered with a heat resistant coating layer, a special process for applying a material having excellent heat resistance is required at the time of manufacture. There is a possibility that the complicated manufacturing process increases. Moreover, when applying to the existing thermal overload relay, it was necessary to take out the corresponding heat element and apply a material having excellent heat resistance, which was complicated.

  In view of the above circumstances, the present invention has no fear of increasing a complicated manufacturing process, can be easily applied to an existing thermal overload relay, and has good thermal interference between the thermal actuators between the phases. It is an object of the present invention to provide a heater structure for a thermal overload relay that can be suppressed to a low level.

  In order to achieve the above object, the heater structure of the thermal overload relay according to claim 1 of the present invention has a heater wire having one end connected to the main circuit and the other end connected to the bimetal. In the heater structure of the thermal overload relay, which comprises a plurality of thermally responsive elements arranged in a rotating manner and arranged in a side-by-side manner, and opens and closes contacts using the deformation of the bimetal, an insulating material And a tubular body that covers the periphery of the thermally responsive element in such a manner that at least one of the thermally responsive elements adjacent to each other enters relatively inside.

  According to a second aspect of the present invention, there is provided a heater structure for a thermal overload relay according to the first aspect, wherein the tubular body is flexible and covers the periphery of the bimetal. It is characterized by comprising the same insulating material.

  In the present invention, since the tubular body made of an insulating material covers the periphery of the thermal response element in such a manner that at least one of the thermal response elements adjacent to each other enters relatively inside, the heat from the adjacent thermal response element is obtained. Transmission is suppressed and thermal interference can be reduced. In addition, since the surroundings of the thermal response element are simply covered with a tubular body in such a manner that the target thermal response element relatively enters the interior, a special process as in the prior art is not required. In addition, when applied to an existing thermal overload relay, the surroundings of the corresponding thermal response element may be covered with a tubular body, which can be easily performed. Therefore, there is no possibility of increasing the complicated manufacturing process, it can be easily applied to an existing thermal overload relay, and the thermal interference of the thermal actuator between each phase can be satisfactorily suppressed. Play.

  Exemplary embodiments of a heater structure for a thermal overload relay according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic view schematically showing an internal structure of a thermal overload relay having a heater structure of the present invention. The thermal overload relay illustrated here is applied to, for example, a circuit breaker for wiring, an electromagnetic contactor, and the like, and is for performing overcurrent protection and phase loss protection for a motor or the like, and includes a case 1. .

  The case 1 is a housing made of, for example, a thermoplastic resin, and has a heater structure 10 inside. The heater structure 10 is provided in such a manner that a plurality (three in the illustrated example) of heat elements are arranged in parallel on the left and right. The heat element is a thermally responsive element corresponding to each of the R, S, and T phases of the main circuit. Such a heat element includes a bimetal 11 and a heater wire 13 as shown in FIG.

  The bimetal 11 is in the form of a strip provided corresponding to each of the R, S, and T phases of the main circuit. An insulating tape 12 is affixed to the side surface of the bimetal 11. The bimetal 11 is fixed to the case 1 with the upper end supported by the bimetal support 14. A connection line 15 is connected to the bimetal support 14.

  The heater wire 13 has one end connected to the lower end of the bimetal 11 and the other end connected to the main terminal 16 of the main circuit, and is wound around the bimetal 11 with an insulating tape 12 interposed. As a result, the energization path of the heat element becomes the connection line 15 -bimetal support 14 -bimetal 11 -heater wire 13 -main terminal 16.

  A shifter mechanism 2 is linked to such a heat element. The shifter mechanism 2 is arranged to be slidably connected to the lower end side operation end of the heat element of each phase, more specifically, to the lower end side operation end of the bimetal 11 of each phase. Although not clearly shown in the drawing, the shifter mechanism 2 reverses the reversal spring mechanism by sliding and opens and closes the contacts. Here, since the configurations of the shifter mechanism 2, the reversing spring mechanism, and the contacts are the same as those conventionally known, description of these specific configurations is omitted here.

  As shown in FIG.1 and FIG.3, in the heater structure 10 which is this Embodiment, the circumference | surroundings of the heat element (heat element in the center side) corresponding to S phase are covered with the insulating tube 20, for example. That is, the insulating tube 20 covers the periphery of one of the adjacent heat elements.

  The insulating tube 20 is a flexible cylindrical tubular body formed of an insulating material, and includes a hollow portion 21 into which a corresponding heat element enters relatively. Here, the insulating tube 20 is preferably the same as the insulating tape 12, and examples thereof include a silicone glass tube, a heat-resistant resin tube, a silicone rubber tube, and the like. In particular, a silicone glass tube is used. preferable. Moreover, as an insulating material, a material having a low thermal conductivity is preferable from the viewpoint of suppressing heat transfer.

  As shown in FIG. 4, the insulating tube 20 covers the periphery of the heat element in such a manner that the S-phase heat element relatively enters the hollow portion 21.

  Thus, in the heater structure 10 according to the present embodiment, the R-phase heat element (the heat element on the leftmost side in FIG. 1) or the T-phase heat element (the heat on the rightmost side in FIG. 1). Heat transfer from the element) to the S-phase heat element is suppressed, and thermal interference can be reduced. In addition, since the target heat element (S-phase heat element) is only covered with the insulating tube 20 around the heat element so as to relatively enter the hollow portion 21 (inside), No special process is required to cover the surrounding area with a heat-resistant coating layer. Moreover, when applying to the existing thermal overload relay, the circumference | surroundings of the applicable heat element should just be covered with the insulating tube 20, and it can carry out easily. Therefore, there is no possibility of increasing a complicated manufacturing process, it can be easily applied to an existing thermal overload relay, and the thermal interference of the heat element between each phase can be well suppressed. Thus, since heat interference can be suppressed satisfactorily, the phase loss characteristics are also excellent.

  Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. In the above-described embodiment, the case where the periphery of the S-phase heat element is covered with the insulating tube 20 has been described. However, the present invention covers at least one of the adjacent heat-responsive elements (heat elements). As long as it is possible, the periphery of the R-phase and T-phase thermal responsive elements (heat elements) may be covered.

  In the above-described embodiment, a cylindrical shape is shown as an example of the insulating tube 20, but the present invention is not limited to the shape.

  As described above, the thermal overload relay according to the present invention is applied to, for example, a circuit breaker or a magnetic contactor, and is useful for performing overcurrent protection and phase loss protection for a motor or the like.

It is a schematic diagram which shows typically the internal structure of the thermal overload relay which has a heater structure of this invention. It is a figure which shows the principal part of the heater structure shown in FIG. It is a figure which shows the principal part of the heater structure shown in FIG. It is a figure which shows the principal part of the heater structure shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 10 Heater structure 11 Bimetal 12 Insulation tape 13 Heater wire 14 Bimetal support part 15 Connection line 16 Main terminal 20 Insulation tube 21 Hollow part

Claims (2)

A heater wire having one end connected to the main circuit and the other end connected to the bimetal comprises a plurality of thermally responsive elements arranged in a manner to wind the bimetal in a side-by-side manner. In the heater structure of a thermal overload relay that opens and closes contacts using deformation,
A thermal overload comprising a tubular body made of an insulating material and covering the periphery of at least one of the thermal response elements adjacent to each other so as to relatively enter the interior. Relay heater structure.   2. The heater structure of a thermal overload relay according to claim 1, wherein the tubular body is made of the same insulating material as that of the covering that has flexibility and covers the periphery of the bimetal.

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