JP2018067457A - Protection element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat efficiency in a protection element including an electrode and a resistor.SOLUTION: A protection element 10 comprises a positive electrode 22 and a negative electrode 24, a conductor 26, a joining material 28, a compression coil spring 32, a wire wound resistor, and an insulating solid for heat transfer. The positive electrode 22 and the negative electrode 24 are arranged so as to face to each other. The conductor 26 is arranged between and across the positive electrode 22 and the negative electrode 24. The conductor 26 allows a current to flow through between the positive electrode 22 and the negative electrode 24. The joining material 28 joins the conductor 26 to the positive electrode 22 and the negative electrode 24. The compression coil spring 32 applies separation force to the conductor 26. A joining strength of the joining material 28 falls below a prescribed strength at a prescribed temperature. The positive electrode 22 and the negative electrode 24 further include insulator contact parts. Each insulator contact part is provided so as to protrude from an opposed plane 102. The insulator contact part comes into contact with the insulating solid for heat transfer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a protection element.

  Patent document 1 discloses the invention concerning a protection element. The protection element according to Patent Document 1 includes a pair of electrodes, a heating piece, a bonding material, a resistor, and an elastic body. The pair of electrodes are arranged to face each other. The heating piece is disposed across the pair of electrodes. The heating piece generates heat when a current flows. The bonding material bonds the heating piece to each of the pair of electrodes. The resistor generates heat when a current flows. As a result, the resistor acts as a heat source. The elastic body is disposed between the pair of electrodes. The elastic body applies a separating force to the heating piece. The separation force is a force in a direction in which the heating piece is separated from the pair of electrodes. The strength of the bonding material is lower than a predetermined strength at a predetermined temperature. The predetermined temperature is a temperature reached by the heat generation of the heating piece. The predetermined strength is the strength that can withstand the separation force. The protection element further includes a shielding insulator and a magnetic field generation unit. The shielding insulator is disposed between the pair of electrodes so as to shield the other when viewed from one of the pair of electrodes. The magnetic field generator generates a magnetic force between the pair of electrodes in advance.

  In the protective element disclosed in Patent Document 1, the heating piece is separated from the electrode by the elastic body. Thereby, the electric current between electrodes is interrupted | blocked. When an arc is generated between the electrodes after the current is interrupted, the arc receives a Lorentz force due to the magnetic force generated by the magnetic field generator. The arc is extended by receiving the Lorentz force. Further, when viewed from one of the pair of electrodes, the other is shielded by a shielding insulator. Since it is blocked by the shielding insulator, the arc from one of the pair of electrodes reaches the other of the electrodes while avoiding the shielding insulator. The arc extends to avoid shielding insulators. When the arc extends due to the Lorentz force and the arc avoiding the shielding insulator, the arc voltage rises compared to when it does not extend. Moreover, the arc is cooled by being extended. The arc becomes difficult to sustain due to the synergistic effect of the increase in arc voltage and the cooling of the arc. As a result, in the protection element disclosed in Patent Document 1, a large current can be passed.

JP2013-98134A

  However, the protection element disclosed in Patent Document 1 has room for improvement in thermal efficiency when the strength of the bonding material is reduced by the heat generated by the resistor. The present invention has been made to solve such problems. The objective of this invention is improving the thermal efficiency in the protection element provided with the electrode and the resistor.

  The protection element of the present invention will be described with reference to the drawings. It should be noted that the reference numerals in the figure are used in this column in order to help understanding of the contents of the invention, and are not intended to limit the contents to the illustrated range.

  In order to solve the above-described problem, according to an aspect of the present invention, the protective element 10 includes a pair of electrodes 22 and 24, a current-carrying body 26, a bonding material 28, an elastic body 32, and resistors 70 and 72. And an insulating solid 74 for heat transfer. The pair of electrodes 22 and 24 are arranged to face each other. The energizing body 26 is disposed across the pair of electrodes 22 and 24. The energizing body 26 is in a state where current can flow between the pair of electrodes 22 and 24. The bonding material 28 bonds the electric current body 26 to each of the pair of electrodes 22 and 24. The elastic body 32 is disposed between the pair of electrodes 22 and 24. The elastic body 32 applies a separating force to the electric current body 26. The resistors 70 and 72 are disposed between the pair of electrodes 22 and 24. Resistors 70 and 72 generate heat transferred to the bonding material 28. The heat transfer insulating solid 74 is in contact with the resistors 70 and 72. The heat transfer insulating solid 74 is in contact with at least one of the pair of electrodes 22 and 24. The separation force is a force in a direction in which the electric current body 26 is separated from the pair of electrodes 22 and 24. The bonding strength of the bonding material 28 is lower than a predetermined strength at a predetermined temperature. The predetermined temperature is a temperature reached by the heat generation of the resistors 70 and 72. The predetermined strength is the strength that can withstand the separation force. Both of the pair of electrodes 22 and 24 have an end portion 100 and a facing portion 102. The end portion 100 is joined to the electric current body 26. The facing portion 102 continues to the end portion 100. The facing portion 102 faces the resistors 70 and 72. At least one of the pair of electrodes 22 and 24 further includes insulator contact portions 110 and 120. The insulator contact portions 110 and 120 are provided so as to protrude from the facing portion 102. The insulator contact portions 110 and 120 are in contact with the heat transfer insulating solid 74.

  When the insulator contact portions 110 and 120 protrude from the facing portion 102 and come into contact with the heat transfer insulating solid 74, the heat transfer insulation in the electrodes 22 and 24 having the insulator contact portions 110 and 120 is compared to the case where the insulator contact portions 110 and 120 contact the heat transfer insulating solid 74. The contact area with the solid 74 is increased. When the contact area is increased, heat is easily transferred from the heat transfer insulating solid 74 to the electrodes 22 and 24. When the heat is easily transmitted, the heat generated by the resistors 70 and 72 is not transmitted to the bonding material 28. When the heat that is not transmitted to the bonding material 28 is reduced, the thermal efficiency for reducing the bonding strength of the bonding material 28 is improved.

  Moreover, it is desirable that both of the pair of electrodes 22 and 24 described above have the insulator contact portions 110 and 120. In this case, the insulator contact portions 110 and 120 included in one of the pair of electrodes 22 and 24 are opposite to the insulator contact portions 110 and 120 included in the other of the pair of electrodes 22 and 24 when viewed from the resistors 70 and 72. It is desirable to protrude from the side.

  In the case described below, both the heat generated by the resistors 70 and 72 and flowing in opposite directions is transmitted to the electrodes 22 and 24. In this case, the insulator contact portions 110 and 120 included in one of the pair of electrodes 22 and 24 are the insulator contact portions 110 and 120 included in the other of the pair of electrodes 22 and 24 when viewed from the resistors 70 and 72. Is the case protruding from the opposite side. As a result, less of the heat generated by the resistors 70 and 72 is not transmitted to the bonding material 28. When the heat that is not transmitted to the bonding material 28 is reduced, the thermal efficiency for reducing the bonding strength of the bonding material 28 is improved.

  Alternatively, it is desirable that the insulator contact portion included in one of the pair of electrodes 22 and 24 described above has a pair of space forming pieces 110. The space forming piece 110 protrudes from the facing portion 102 in the same direction. The space forming pieces 110 are separated so as to form a space. All the space forming pieces 110 are in contact with the heat transfer insulating solid 74.

  When the space forming piece 110 is separated so as to form a space, it is easy to replenish another heat transfer insulating solid 74 in the gap between the heat transfer insulating solid 74 and the electrodes 22, 24 already existing from the space. become. If another insulating solid 74 for heat transfer can be supplemented, the contact area between the electrodes 22 and 24 and the resistors 70 and 72 can be increased. When the contact area is increased, heat is easily transferred from the heat transfer insulating solid 74 to the electrodes 22 and 24. When the heat is easily transmitted, the heat generated by the resistors 70 and 72 is not transmitted to the bonding material 28. When the heat that is not transmitted to the bonding material 28 is reduced, the thermal efficiency for reducing the bonding strength of the bonding material 28 is improved.

  Alternatively, it is desirable that the above-described insulating solid 74 for heat transfer has the heating body contact portion 82 and the ceramic plate 84. The heating body contact portion 82 is in close contact with the resistors 70 and 72. The ceramic plate 84 is in close contact with the heating body contact portion 82.

  When the ceramic plate 84 is in close contact with the heating body contact portion 82, even if the strength of the heating body contact portion 82 is reduced by receiving heat from the resistors 70 and 72, deformation of the heat transfer insulating solid 74 is suppressed. .

  ADVANTAGE OF THE INVENTION According to this invention, the thermal efficiency in the protection element provided with the electrode and the resistor can be improved.

It is a perspective view in the state where a part of protection element concerning a certain embodiment of the present invention was removed. It is a figure which shows the positive electrode and negative electrode concerning a certain embodiment of this invention. It is a side view of a protection element concerning an embodiment of the present invention. It is an external view of the intermediate material in an embodiment of the present invention. It is a figure which shows the electric current body immediately after leaving | separating from the positive electrode and negative electrode in one embodiment of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Description of configuration]
FIG. 1 is a perspective view of a protection element 10 according to the present embodiment. In FIG. 1, the protection element 10 is shown in an assembled state. In this figure, a part of the case 46 of the protective element 10 is removed. Based on FIG. 1, the structure of the protection element 10 concerning this embodiment is demonstrated. The protection element 10 according to the present embodiment includes an insulating base 20, a positive electrode 22, a negative electrode 24, a current conductor 26, a bonding material 28, a lead insulator 30, a compression coil spring 32, and a spring insulator. 34, a first lead terminal 36, a second lead terminal 38, a heating body 40, a tubular support body 42, a pair of block-like permanent magnets 44, and a case 46.

  The insulating base 20 is a synthetic resin member used as a base. The insulating base 20 has heat resistance to such an extent that it is not deformed by the heat generated by the heating body 40. The positive electrode 22 and the negative electrode 24 are fixed to the insulating base 20. By being fixed to the insulating base 20, the positive electrode 22 and the negative electrode 24 are disposed so as to face each other. The insulating base 20 includes a first lead support portion 56 and a second lead support portion 58.

  In the present embodiment, the positive electrode 22 and the negative electrode 24 are connected to a known power line (not shown). A power line is an electric wire for supplying electric power to a load. A load (not shown) is connected to the power line. An example of such a load is a motor. When a current flows between the positive electrode 22 and the negative electrode 24, a current flows through the power line. When a current flows through the power line, power is supplied to the load.

  In the case of the present embodiment, the energization body 26 is disposed across the positive electrode 22 and the negative electrode 24. In other words, when the protective element 10 is assembled, the energizing body 26 is bonded to the tip of the positive electrode 22 and the tip of the negative electrode 24. The electrical conductor 26 is made of metal. Accordingly, the current-carrying body 26 is joined to the positive electrode 22 and the negative electrode 24 so that a current can flow between the positive electrode 22 and the negative electrode 24. In the case of this embodiment, a hole (not shown) is formed in a portion of the energization body 26 that is not joined to the positive electrode 22 or the negative electrode 24.

  The bonding material 28 bonds the electric current body 26 to the positive electrode 22. In the case of the present embodiment, another bonding material 28 bonds the electric current body 26 to the negative electrode 24. In the case of this embodiment, the bonding strength of the bonding material 28 is lower than the predetermined strength at a predetermined temperature. In the case of this embodiment, the “predetermined temperature” is a temperature reached by the heat generation of the heating body 40. In the case of this embodiment, the “predetermined strength” is a strength that can withstand the separation force. In the case of this embodiment, the “separation force” is a force in a direction in which the energizing body 26 joined to the positive electrode 22 and the negative electrode 24 is away from the positive electrode 22 and the negative electrode 24. In the case of this embodiment, this separating force is applied by the compression coil spring 32. In the present embodiment, the bonding material 28 is an alloy having the above-described “predetermined temperature” as a melting point. The designer of the protection element 10 according to the present embodiment can select an arbitrary alloy having a bonding strength lower than a predetermined strength at a predetermined temperature as the bonding material 28 from among known alloys.

  The lead insulator 30 is disposed between the energizing body 26 and the compression coil spring 32. In the case of this embodiment, the lead insulator 30 is fixed to the energizing body 26. A hole (not shown) is formed in the center of the lead insulator 30. This hole communicates with the hole of the electric current body 26.

  The compression coil spring 32 is disposed at a position that satisfies the following requirements. The first requirement is that it is between the current-carrying body 26 and the heating body 40. The second requirement is that it is between the positive electrode 22 and the negative electrode 24. The compression coil spring 32 applies a force in a direction away from the positive electrode 22 and the negative electrode 24 to the energizing body 26. For this reason, the compression coil spring 32 is in a compressed state until the bonding strength of the bonding material 28 falls below the predetermined strength described above. In the case of this embodiment, the compression coil spring 32 is made of stainless steel (that is, made of a conductor).

  The spring insulator 34 is disposed between the compression coil spring 32 and the heating body 40. The spring insulator 34 prevents the compression coil spring 32 from coming into direct contact with the heating body 40. Thereby, the compression coil spring 32 and the heating body 40 are insulated. A hole (not shown) is opened in the center of the spring insulator 34.

  The first lead terminal 36 and the second lead terminal 38 are fixed to the insulating base 20. The first lead terminal 36 and the second lead terminal 38 are connected to the heating body 40 and a known signal line (not shown). The signal line is an electric wire for controlling the heating body 40. When a current flows through the signal line, a current also flows through the first lead terminal 36 and the second lead terminal 38. When a current flows through the first lead terminal 36 and the second lead terminal 38, a current flows through the heating body 40.

  The heating body 40 is disposed so as to be sandwiched between the positive electrode 22 and the negative electrode 24. The heating body 40 is connected to the first lead terminal 36 and the second lead terminal 38. When a current flows through the first lead terminal 36 and the second lead terminal 38, a current also flows through the heating body 40. The heating element 40 generates heat when a current flows through itself. Thereby, the heating body 40 plays the role of a heat source.

  The tubular support body 42 is disposed between the heating body 40 and the second lead support portion 58. In the present embodiment, the tubular support 42 is a tubular member. The tubular support 42 supports the heating body 40 that receives a force from the compression coil spring 32.

  The block permanent magnet 44 generates a magnetic force. The pair of block-shaped permanent magnets 44 is arranged so as to sandwich the positive electrode 22 and the negative electrode 24. Therefore, the space in which the pair of block-shaped permanent magnets 44 generates a magnetic force includes the space between the positive electrode 22 and the negative electrode 24. Therefore, a magnetic force is generated between the positive electrode 22 and the negative electrode 24. By generating a magnetic force, even when an arc is generated when the current-carrying body 26 is separated from the positive electrode 22 and the negative electrode 24, the arc can be efficiently cooled.

  The case 46 includes an insulating base 20, a part of the positive electrode 22, a part of the negative electrode 24, a current conductor 26, a bonding material 28, a lead insulator 30, a compression coil spring 32, and a spring insulator. 34, a part of the first lead terminal 36, a part of the second lead terminal 38, the heating body 40, the tubular support 42, and the block-shaped permanent magnet 44 are covered. The case 46 is also a part for fixing the block-shaped permanent magnet 44 at a predetermined position. The material of the case 46 is a synthetic resin. The case 46 has a magnet housing portion (not shown). The block-shaped permanent magnet 44 is accommodated in the magnet accommodating portion.

  FIG. 2 is a diagram showing the positive electrode 22 and the negative electrode 24 according to the present embodiment. These arrangements in FIG. 2 are the same as in the case where they are fixed to the insulating base 20. Based on FIG. 1 and FIG. 2, the structure of the positive electrode 22 and the negative electrode 24 concerning this embodiment is demonstrated.

  In the present embodiment, both the positive electrode 22 and the negative electrode 24 have an end portion 100 and an opposing flat surface 102. The end portion 100 is joined to the electric current body 26. The opposing plane 102 is continuous with the end portion 100. The opposing plane 102 faces the compression coil spring 32 and the heating body 40.

  In the present embodiment, the positive electrode 22 further includes a pair of space forming pieces 110. Each of the pair of space forming pieces 110 is provided so as to protrude from the opposing flat surface 102 of the positive electrode 22. The pair of space forming pieces 110 protrudes from the side opposite to the support contact portion 120 of the negative electrode 24 when viewed from the heating body 40. The pair of space forming pieces 110 is a kind of insulator contact portion according to the present invention.

  In the case of this embodiment, the negative electrode 24 further includes a support contact portion 120. The support contact portion 120 is provided so as to protrude from the opposing flat surface 102 of the negative electrode 24. The support contact portion 120 protrudes from the opposite side to the pair of the space forming pieces 110 of the positive electrode 22 when viewed from the heating body 40. The support contact portion 120 is a kind of insulator contact portion according to the present invention.

  FIG. 3 is a side view of the protection element 10 according to the present embodiment. In FIG. 3, the negative electrode 24, a part of the heating body 40, and a part of the case 46 are removed. Based on FIG. 3, the structure of the heating body 40 concerning this embodiment is demonstrated.

  The heating body 40 according to this embodiment includes a plurality of winding resistors 70 and 72, a heat transfer insulating solid 74, a first lead wire 76, and a second lead wire 78. The winding resistors 70 and 72 are disposed between the positive electrode 22 and the negative electrode 24. In the winding resistors 70 and 72 according to the present embodiment, a resistance wire is wound around a ceramic score (not shown). The winding resistors 70 and 72 generate heat when electric power is supplied. The plurality of winding resistors 70 and 72 are connected in series with each other. The heat transfer insulating solid 74 surrounds the winding resistors 70 and 72. The heat transfer insulating solid 74 is in contact with the positive electrode 22 and the negative electrode 24. Thereby, the heat generated by the plurality of winding resistors 70 and 72 is transmitted to the bonding material 28 through the positive electrode 22 and the negative electrode 24. The first lead wire 76 is connected to the winding resistor 70. The first lead wire 76 passes through the hole of the lead insulator 30 and the hole of the energization body 26. Since the inner diameter of the hole of the lead insulator 30 is smaller than the inner diameter of the hole of the current-carrying body 26, the first lead wire 76 and the current-carrying body 26 are insulated. Further, the first lead wire 76 passes through the hole of the spring insulator 34 and the compression coil spring 32. The first lead wire 76 is connected to the first lead terminal 36. The first lead wire 76 is supported by the first lead support portion 56 of the insulating base 20. The second lead wire 78 is connected to the winding resistor 72 and the second lead terminal 38. The second lead wire 78 is supported by the second lead support portion 58 of the insulating base 20. The second lead 78 penetrates the tubular support 42.

  The insulating solid 74 for heat transfer has a heating body contact portion 82 and a ceramic plate 84. In the case of this embodiment, the material of the heating body adhesion part 82 is a synthetic resin. The heating body contact portion 82 is in close contact with each of the winding resistors 70 and 72. The above-described opposing flat surface 102 of the positive electrode 22 and the negative electrode 24 and the pair of the space forming pieces 110 are in close contact with the heating body contact portion 82. The ceramic plate 84 is in close contact with the heating body contact portion 82. The ceramic plate 84 reinforces the heating body contact portion 82. The support contact portion 120 described above is in close contact with the ceramic plate 84.

[Description of manufacturing method]
The manufacturing method of the protection element 10 according to the present embodiment is as follows. First, the manufacturer includes the insulating base 20, the positive electrode 22, the negative electrode 24, the energization body 26, the lead insulator 30, the compression coil spring 32, and the spring insulation in the protection element 10 according to the present embodiment. A body 34, a first lead terminal 36, a second lead terminal 38, a tubular support 42, a pair of block-shaped permanent magnets 44, and a case 46 are manufactured. Since these manufacturing methods are well known, detailed description thereof will not be repeated here. Next, the manufacturer fixes the negative electrode 24, the first lead terminal 36, and the second lead terminal 38 on the insulating base 20. Next, the manufacturer joins the electric current body 26 to the end portion 100 of the negative electrode 24 with the bonding material 28. In the present embodiment, the bonding material 28 is a known alloy. When the electric current body 26 is joined to the end portion 100 of the negative electrode 24, the manufacturer connects the first lead wire 76 to the first lead terminal 36. The manufacturer connects the second lead wire 78 to the second lead terminal 38. Next, the manufacturer houses the winding resistors 70 and 72, the first lead wire 76, the second lead wire 78, and the ceramic plate 84 in a mold (not shown). When the storing operation into the mold is completed, the manufacturer uses the mold to manufacture the intermediate material 130 by molding. FIG. 4 is an external view of the intermediate material 130. When the intermediate member 130 is manufactured, the manufacturer uses the first lead wire 76 of the intermediate member 130, the hole of the electric current body 26, the hole of the lead insulator 30, the compression coil spring 32, and the spring insulator. 34 holes. When the first lead wire 76 of the intermediate member 130 passes through them, the manufacturer passes the second lead terminal 38 through the tubular support 42. When the second lead terminal 38 penetrates the tubular support 42, the manufacturer places the intermediate material 130 on the support contact portion 120 of the negative electrode 24. When the intermediate material 130 is placed on the support contact portion 120, the manufacturer fixes the positive electrode 22 on the insulating base 20. Thereby, the intermediate member 130 is covered with the pair of the space forming pieces 110 of the positive electrode 22. Next, the manufacturer joins the electric current body 26 to the end portion 100 of the positive electrode 22 with the joining material 28. When the current-carrying body 26 is joined to the end portion 100 of the positive electrode 22, the manufacturer injects synthetic resin between the intermediate material 130, the positive electrode 22, and the negative electrode 24 from between the pair of space forming pieces 110. When the synthetic resin is solidified, the object made of the solidified synthetic resin and the intermediate material 130 becomes the heating body 40. When the synthetic resin is solidified, the manufacturer fixes the case 46 in which the pair of block-shaped permanent magnets 44 is previously stored to the insulating base 20. Thereby, the protection element 10 according to the present embodiment is completed.

[Description of usage]
The usage method of the protection element 10 concerning this embodiment is as follows. First, the user connects the protection element 10 according to the present embodiment to a circuit (not shown) to be protected by the protection element 10 according to the present embodiment. The circuit is for causing a motor or other load to work. In addition to the power line, the circuit includes a sensor, a control device, and a signal line. The power line is an electric wire for supplying power to a load (an example of the load is a motor). The sensor detects an abnormality assumed in advance by the designer of this circuit. The control device operates the protection element 10 according to the present embodiment when the sensor detects the abnormality. The signal line is an electric wire for connecting the control device and the heating body 40 of the protection element 10 according to the present embodiment. The user connects the positive electrode 22 and the negative electrode 24 of the protection element 10 according to the present embodiment to the power line. The user connects the first lead terminal 36 and the second lead terminal 38 to the signal line. Thereby, the protection element 10 according to the present embodiment is in a usable state. During use of this circuit, the power line supplies power supplied from a power source (not shown) to the load. When the sensor detects the above-described abnormality during the supply of electric power, the control device causes a current to flow through the protection element 10 according to the present embodiment via the signal line. The current flows to the heating body 40 via the first lead terminal 36 and the second lead terminal 38. When a current flows through the heating body 40, the heating body 40 generates heat. As a result of the heating body 40 generating heat, when the bonding strength of the bonding material 28 falls below a predetermined strength, the compression coil spring 32 separates the current-carrying body 26 from the positive electrode 22 and the negative electrode 24. FIG. 5 is a view showing the current-carrying body 26 immediately after being separated from the positive electrode 22 and the negative electrode 24 (in FIG. 5, the structure inside the heating body 40 is omitted). When the current-carrying body 26 is separated from the positive electrode 22 and the negative electrode 24, the current flowing through the power line is cut off. When the current is cut off, the supply of power to the load is stopped.

[Description of effects]
As described above, in the protection element 10 according to the present embodiment, the pair of space forming pieces 110 and the support contact portion 120 protrude from the opposing flat surface 102 and contact with the heat transfer insulating solid 74. In that case, compared with the case where it is not so, the contact area to the insulating solid 74 for heat transfer in the positive electrode 22 and the negative electrode 24 becomes large. When the contact area increases, the heat from the heat transfer insulating solid 74 is easily transmitted to the positive electrode 22 and the negative electrode 24. When the heat is easily transmitted, the heat generated by the resistors 70 and 72 is not transmitted to the bonding material 28. When the heat that is not transmitted to the bonding material 28 is reduced, the thermal efficiency for reducing the bonding strength of the bonding material 28 is improved.

  In the protection element 10 according to the present embodiment, the support contact portion 120 protrudes from the opposite side of the pair of space forming pieces 110 when viewed from the resistors 70 and 72. As a result, the heat generated by the resistors 70 and 72 and flowing in the opposite directions is transmitted to either the positive electrode 22 or the negative electrode 24. Since all of the heat is transmitted to either the positive electrode 22 or the negative electrode 24, the heat generated by the resistors 70 and 72 is not transmitted to the bonding material 28. When the heat that is not transmitted to the bonding material 28 is reduced, the thermal efficiency for reducing the bonding strength of the bonding material 28 is improved.

  Further, as shown in FIG. 1, in the protection element 10 according to the present embodiment, the space forming piece 110 is separated so as to form a space. If the space forming piece 110 is separated so as to form a space, it becomes easy to replenish another heating body contact portion 82 in the gap between the heating body contact portion 82 and the positive electrode 22 already existing from the space. If another heating element contact portion 82 can be supplemented, the contact area between the positive electrode 22 and the resistors 70 and 72 can be increased. When the contact area is increased, heat is easily transferred from the heating body contact portion 82 to the positive electrode 22. When the heat is easily transmitted, the heat generated by the resistors 70 and 72 is not transmitted to the bonding material 28. When the heat that is not transmitted to the bonding material 28 is reduced, the thermal efficiency for reducing the bonding strength of the bonding material 28 is improved.

  Further, in the protection element 10 according to the present embodiment, the ceramic plate 84 is in close contact with the heating body contact portion 82. Thereby, even if the intensity | strength of the heating body contact | adherence part 82 falls by having received heat from the resistors 70 and 72, a deformation | transformation of the insulation solid 74 for heat transfer is suppressed.

  In the protection element 10 according to this embodiment, the first lead wire 76 is supported by the first lead support portion 56 of the insulating base 20. The second lead wire 78 is supported by the second lead support portion 58 of the insulating base 20. Thereby, compared with the case where the 1st lead wire 76 and the 2nd lead wire 78 are not supported by the 1st lead support part 56 and the 2nd lead support part 58, heating element 40 especially the 1st lead terminal 36 and the 1st lead terminal 36 Fatigue failure between the joint portion of the one lead wire 76 and the joint portion of the second lead terminal 38 and the second lead wire 78 is less likely to occur.

  In the protection element 10 according to the present embodiment, the tubular support body 42 is disposed between the heating body 40 and the second lead support portion 58. The tubular support 42 supports the heating body 40 that receives a force from the compression coil spring 32. Thereby, when the bonding strength of the bonding material 28 is lower than the predetermined strength, the compression coil spring 32 can sufficiently separate the electric current body 26 from the positive electrode 22 and the negative electrode 24.

<Description of modification>
The protective element 10 described above is illustrated to embody the technical idea of the present invention. The protection element 10 described above can be variously modified within the scope of the technical idea of the present invention.

  For example, the configuration of the heat transfer insulating solid 74 is not limited to that described above. The insulating solid 74 for heat transfer may consist only of the heating body contact portion 82.

  Further, the form of the insulator contact portion is not limited to that described above. Both the positive electrode 22 and the negative electrode 24 may have the support contact portion 120. Any of these may have a pair of space forming pieces 110. However, when both of these have a pair of space forming pieces 110, the heat transfer insulating solid 74 has the heating body contact portion 82 and the ceramic plate 84, and the heating body contact portion 82 is The ceramic plate 84 is desirably supported. Further, the position where the insulator contact portion protrudes may not be a position opposite to each other as viewed from the resistors 70 and 72.

  The material of the insulating base 20 is not particularly limited. For example, phenol resin can be used as the material. The materials of the positive electrode 22 and the negative electrode 24 that are a pair of electrodes are not particularly limited. For example, copper or tin-plated brass can be used as the material. The material of the electrical conductor 26 is not particularly limited.

  Further, the material of the bonding material 28 is not particularly limited. Examples of the material include a pure metal and a conductive adhesive in addition to an alloy.

  Further, instead of providing the lead insulator 30, an insulating film may be formed on the surface of the electric conductor 26.

  Further, the protection element 10 may include another elastic body instead of the compression coil spring 32.

  Further, the protection element 10 may include another resistor instead of the winding resistors 70 and 72.

  Moreover, the positive electrode 22 and the negative electrode 24 may have a facing portion that faces the winding resistors 70 and 72 instead of the facing flat surface 102. In this case, the form of the facing portion is not particularly limited. For example, the facing portion may be a convex surface that protrudes toward the winding resistors 70 and 72. The facing portion may be a surface on which a plurality of protrusions protruding toward the winding resistors 70 and 72 protrude.

DESCRIPTION OF SYMBOLS 10 ... Protection element 20 ... Insulation base 22 ... Positive electrode 24 ... Negative electrode 26 ... Current supply body 28 ... Joining material 30 ... Lead insulator 32 ... Compression coil spring 34 ... Spring insulator 36 ... First lead terminal 38 ... Second Lead terminal 38 ... electric current body 40 ... heating body 42 ... tubular support 44 ... block-shaped permanent magnet 46 ... cases 70, 72 ... winding resistor 74 ... insulating solid for heat transfer 76 ... first lead wire 78 ... second Lead wire 82 ... heating body adhesion part 84 ... ceramic plate 100 ... end part 102 ... opposed plane 110 ... space forming piece 120 ... support contact part 130 ... intermediate material

Claims (4)

A pair of electrodes arranged to face each other;
An electrical conductor that is disposed across the pair of electrodes and that allows a current to flow between the pair of electrodes;
A bonding material for bonding the current-carrying member to each of the pair of electrodes;
An elastic body that is disposed between the pair of electrodes and applies a separating force to the energization body;
A resistor disposed between the pair of electrodes and generating heat transmitted to the bonding material;
An insulating solid for heat transfer that contacts the resistor and contacts at least one of the pair of electrodes;
The separation force is a force in a direction in which the current-carrying body is separated from the pair of electrodes,
The bonding strength of the bonding material is lower than a predetermined strength at a predetermined temperature,
The predetermined temperature is a temperature reached by heat generation of the resistor;
The predetermined strength is a protective element that is strong enough to withstand the separation force,
Both of the pair of electrodes are
An end portion to be joined to the electric current body,
And having an opposing portion that is continuous with the end portion and faces the resistor,
At least one of said pair of electrodes is further provided with the insulator contact part which is provided so that it may protrude from the said opposing part, and contacts the said insulating solid for heat transfer, The protection element characterized by the above-mentioned. Both of the pair of electrodes have the insulator contact portion,
2. The insulator contact portion of one of the pair of electrodes protrudes from the side opposite to the insulator contact portion of the other of the pair of electrodes when viewed from the resistor. The protective element as described in.   The insulator contact portion of one of the pair of electrodes protrudes from the facing portion in the same direction and is separated so as to form a space, and both have a pair of space forming pieces that contact the insulating solid for heat transfer. The protective element according to claim 2, wherein The insulating solid for heat transfer is
A heating body contact portion that is in close contact with the resistor;
The protective element according to claim 1, further comprising a ceramic plate that is in close contact with the heating body contact portion.

Images