JP2023175390A - protection element - Google Patents

Abstract

To provide a protection element which is suitable for being used as a temperature fuse under a high temperature environment due to an abnormal heat generation of a protected apparatus.SOLUTION: A protection element 10 comprises: a heat transfer material 20; a pair of electrodes 22 and 24; a conductor member 30; bonding members 32 and 34; an elastic body 38; a cylindrical body 48; and a movement suppression body 50. The cylindrical body 48 houses the heat transfer material 20 so that one part is exposed. The movement suppression body 50 is arranged into an inner part of the cylindrical body 48. The movement suppression body 50 suppresses the movement of the heat transfer material 20 in an inner part of the cylindrical body 48. The cylindrical body 48 includes: a trunk part 130; and a dropout prevention part 132. The trunk part 130 forms a space as mentioned below. The space is one in which each part of the pair of electrodes 22 and 24, the conductor member 30, the bonding members 32 and 34, the elastic body 38, the heat transfer material 20, and the movement suppression body 50 are housed. The dropout prevention part 132 prevents a dropping of the heat transfer material 20 from the trunk part 130.SELECTED DRAWING: Figure 1

Description

The present invention relates to a protection element.

Patent Document 1 discloses an invention related to a protection element. The protection element according to Patent Document 1 includes a pair of electrodes, a heating element, a bonding material, an elastic body, and a magnetic force generating section. The pairs of electrodes face each other. A heating element is disposed astride the pair of electrodes. A heating element generates heat when current flows through it. A bonding material bonds the heating element to each pair of electrodes. An elastic body is placed between the pair of electrodes. The elastic body applies a separating force to the heating element. The magnetic force generating section generates magnetic force between the pair of electrodes in advance. The separation force is the force that causes the heating element to separate from the pair of electrodes. The bonding strength of the bonding material falls below a predetermined strength at a predetermined temperature. The predetermined temperature is the temperature reached by the heat generated by the heating element. The predetermined strength is the strength that can withstand the separation force. The magnetic force generation section includes a samarium cobalt magnet, a magnet accommodation space forming section, and a filler. The magnet accommodating space forming section forms a magnet accommodating space. A samarium cobalt magnet is housed in the magnet housing space. The filling material is housed in the magnet housing space together with the samarium cobalt magnet. The filler is filled in the gap between the samarium cobalt magnet and the magnet housing space forming part. The protection element disclosed in Patent Document 1 can further improve the reliability of operation in a high-temperature environment.

JP 2021-141013 Publication

However, the protection element disclosed in Patent Document 1 has a problem that it is difficult to use it as a thermal fuse that operates in a high temperature environment due to abnormal heat generation of the device to be protected (protected device). The high-temperature environment due to abnormal heat generation of the protected device as used herein means the temperature around the protection element that is reached due to some abnormality occurring in the protected device. The thermal fuse referred to here refers to a thermal fuse that receives heat from either the protected device itself or something that is in direct or indirect contact with the protected device (heat source), and uses that heat to directly or indirectly supply current to the protected device. This is a protection element that indirectly cuts off the power. The reason why it is difficult to use the protection element disclosed in Patent Document 1 as a thermal fuse that operates in such a high-temperature environment is that it is difficult to transfer heat from the heat source to the bonding material. The present invention solves these problems. An object of the present invention is to provide a protection element suitable for use as a thermal fuse in a high-temperature environment due to abnormal heat generation of protected equipment.

The protection element of the present invention will be explained based on the drawings. Note that the reference numerals in the figures are used in this column to aid understanding of the content of the invention, and are not intended to limit the content to the illustrated range.

In order to solve the above problems, according to one aspect of the present invention, the protection element 10 includes a pair of electrodes 22 and 24, a conductor member 30, bonding materials 32 and 34, and an elastic body 38. The pair of electrodes 22, 24 face each other. Conductor member 30 is disposed straddling the pair of electrodes 22, 24. The bonding materials 32 and 34 bond the conductor member 30 to each pair of electrodes 22 and 24 so as to be electrically conductive thereto. Elastic body 38 is disposed between the pair of electrodes 22, 24. The elastic body 38 applies a separation force to the conductor member 30. The separation force is a force that causes conductor member 30 to separate from the pair of electrodes 22, 24. The bonding strength of the bonding materials 32 and 34 falls below a predetermined strength at a predetermined temperature. The predetermined strength is the strength that can withstand the separation force. The protection element 10 further includes a heat transfer body 20, a cylindrical body 48, and a movement suppressor 50. Heat transfer body 20 is connected to at least one of the pair of electrodes 22, 24. When heat transfer body 20 receives heat, it transfers the heat to at least one of the pair of electrodes 22 and 24. The cylindrical body 48 accommodates the heat transfer body 20 so that a part of the heat transfer body 20 is exposed. The movement suppressor 50 is arranged inside the cylindrical body 48 . The movement suppressor 50 suppresses movement of the heat transfer body 20 inside the cylindrical body 48 . The cylindrical body 48 has a body portion 130 and a fall prevention portion 132. The body 130 forms the space described below. The space accommodates a portion of each pair of electrodes 22 and 24, a conductor member 30, bonding materials 32 and 34, an elastic body 38, a heat transfer body 20, and a movement suppressor 50. The falling-off prevention part 132 prevents the heat transfer body 20 from falling off from the body part 130. The heat transfer body 20 is made of one of the group consisting of a ceramic plate, an insulated metal plate, a synthetic resin plate mixed with any one of ceramic powder, glass filler, and frit glass, and a silicon plate. shall be.

The falling-off prevention part 132 prevents the heat transfer body 20 from falling off from the body part 130. The movement suppressor 50 suppresses movement of the heat transfer body 20 inside the cylindrical body 48 . Thereby, even if the heat transfer body 20 tries to move to the inner depth of the cylindrical body 48, the movement of the heat transfer body 20 is suppressed by the movement suppressing body 50. Furthermore, a portion of the heat transfer body 20 is exposed. The material is made of a material that is difficult to weld to the cylindrical body 48 or adhere to the cylindrical body 48 with adhesive because the movement of the heat conductive body 20 is suppressed and a part of the heat conductive body 20 is exposed. The heat transfer body 20 can receive heat from a heat source. The heat is transferred to at least one of the pair of electrodes 22,24. When the heat is transferred to at least one of the pair of electrodes 22 and 24, the heat is also transferred to the bonding materials 32 and 34. When the bonding materials 32 and 34 to which the heat has been transferred reach a predetermined temperature, the bonding strength of the bonding materials 32 and 34 falls below the predetermined strength. If the bonding strength of the bonding materials 32, 34 falls below a predetermined strength, the bonding materials 32, 34 will no longer be able to withstand the separation force. The conductor member 30 is separated from the electrodes 22 and 24 by the elastic body 38 because it is no longer able to withstand the separation force. This cuts off the current between the electrodes 22 and 24. The heat transfer body 20 is made of one of the group consisting of a ceramic plate, an insulated metal plate, a synthetic resin plate mixed with any one of ceramic powder, glass filler, and frit glass, and a silicon plate. shall be. This suppresses a decrease in mechanical strength of the heat transfer body 20 when it receives heat from a heat source and reaches a high temperature. As a result, a protection element suitable for use as a thermal fuse in a high temperature environment due to abnormal heat generation of the protected device is provided.

Moreover, it is desirable that the electrodes 22 and 24 described above have a joining portion 110 and a heat conductor facing portion 112. The joining portion 110 is joined to the conductor member 30. The heat transfer body facing portion 112 is continuous with the joining portion 110 . The heat transfer body facing portion 112 faces the heat transfer body 20 . In this case, it is desirable that the movement suppressing body 50 has the accommodation space forming body 70 and the filler 72. The accommodation space forming body 70 forms an accommodation space 158. The filler 72 is arranged in a portion of the interior of the body 130 that is outside the accommodation space forming body 70 . The filler 72 contacts the inner circumferential surface of the body 130 and the outer circumferential surface of the accommodation space forming body 70 . In this case, it is desirable that the joint portion 110 of each pair of electrodes 22 and 24, the conductor member 30, the joint materials 32 and 34, and the elastic body 38 are arranged in the accommodation space 158.

The movement suppressing body 50 includes an accommodation space forming body 70 and a filler 72. The accommodation space forming body 70 forms the accommodation space 158. In the housing space 158, the bonding portion 110 of each pair of electrodes 22, 24, the conductor member 30, the bonding materials 32, 34, and the elastic body 38 are arranged. As a result, the movement of the heat transfer body 20 inside the body 130 by the accommodation space forming body 70 and the filler 72 is prevented from being impaired by the movement of the elastic body 38.

Alternatively, it is desirable that the accommodation space forming body 70 described above has the wall surface forming part 150 and the electrode contact part 152. The wall forming part 150 forms a wall surrounding the accommodation space 158. The electrode contact portion 152 protrudes from the end of the wall surface forming portion 150. The electrode contact portion 152 contacts the heat conductor facing portions 112 of the electrodes 22 and 24 inside the body portion 130 .

The electrode contact portion 152 contacts the heat conductor facing portions 112 of the electrodes 22 and 24 inside the body portion 130 . This makes it possible to suppress the movement of the heat transfer body 20 facing across the electrodes 22 and 24, compared to the case where the electrode contact portion 152 faces away from the heat conduction body facing portion 112 of the electrodes 22 and 24. . When the movement of the heat transfer body 20 is suppressed, the possibility that heat is difficult to be transmitted to the electrodes 22 and 24 due to the movement is also suppressed. As a result, a protection element suitable for use as a thermal fuse in a high temperature environment due to abnormal heat generation of the protected device is provided.

Alternatively, it is desirable that the protection element 10 described above further includes thermally conductive materials 26 and 28. Thermal conductive materials 26 and 28 are arranged between the heat transfer body 20 and the heat transfer body facing portions 112 of the electrodes 22 and 24. The heat conductive materials 26 and 28 are continuous with the heat transfer body 20 and the heat transfer body facing portions 112 of the electrodes 22 and 24.

The thermally conductive materials 26 and 28 make it easier to transfer heat from the heat transfer body 20 to the portions 112 of the electrodes 22 and 24 facing the heat transfer body, compared to the case where the heat conductive materials 26 and 28 are not provided. As a result, a protection element suitable for use as a thermal fuse in a high temperature environment due to abnormal heat generation of the protected device is provided.

According to the present invention, a protection element suitable for use as a thermal fuse in a high temperature environment due to abnormal heat generation of a protected device is provided.

FIG. 2 is a perspective view of a protection element according to an embodiment of the invention. FIG. 2 is a sectional view taken along line AA of a protection element according to an embodiment of the present invention. FIG. 2 is a diagram showing a situation in which a heat transfer body according to an embodiment of the present invention is connected to a positive electrode. FIG. 2 is a perspective view of a cylindrical body according to an embodiment of the present invention. FIG. 1 is a perspective view of an accommodation space forming body according to an embodiment of the present invention.

Hereinafter, the present invention will be explained in detail based on the drawings. In the following description, the same parts are given the same reference numerals. Their names and functions are the same. Therefore, detailed descriptions thereof will not be repeated.

[Configuration description]
FIG. 1 is a perspective view of a protection element 10 according to this embodiment. In FIG. 1, a portion of the protection element 10 is cut away. FIG. 2 is an AA cross-sectional view of the protection element 10 according to this embodiment. The configuration of the protection element 10 according to this embodiment will be explained based on FIGS. 1 and 2.

The protection element 10 according to the present embodiment includes a heat transfer body 20, a positive electrode 22, a negative electrode 24, a positive thermal conductive material 26, a negative thermal conductive material 28, a conductor member 30, a positive electrode bonding material 32, and a negative electrode. It includes a bonding material 34, an insulating spacer 36, a compression coil spring 38, an insulating plate 40, a guide lead 42, a positive magnet 44, a negative magnet 46, a cylindrical body 48, and a movement suppressor 50. .

In the case of this embodiment, the heat transfer body 20 is a member made of alumina. The specific configuration of the heat transfer body 20 will be described later.

The positive electrode 22 and the negative electrode 24 correspond to a pair of electrodes in the protection element 10 according to this embodiment. The positive electrode 22 and the negative electrode 24 are placed on the heat transfer body 20 . Thereby, the heat transfer body 20 will be connected to the positive electrode 22 and the negative electrode 24. The specific configuration of the positive electrode 22 and negative electrode 24 in this embodiment will be described later. A specific configuration for connecting the positive electrode 22 and the negative electrode 24 to the heat transfer body 20 will also be described later.

The positive electrode thermally conductive material 26 is arranged between the heat transfer body 20 and the positive electrode 22. The negative electrode thermally conductive material 28 is arranged between the heat transfer body 20 and the negative electrode 24. In this embodiment, the positive electrode thermally conductive material 26 and the negative electrode thermally conductive material 28 are collectively referred to as a "thermal conductive material."

The conductor member 30 is a rectangular member with a hole in the center. The conductor member 30 is disposed astride between the positive electrode 22 and the negative electrode 24. Current can flow from the positive electrode 22 to the negative electrode 24 via the conductor member 30.

In this embodiment, the positive electrode bonding material 32 is used to bond the conductor member 30 to the positive electrode 22. In this embodiment, the negative electrode bonding material 34 is used to bond the conductor member 30 to the negative electrode 24. The bonding strength of the positive electrode bonding material 32 and the negative electrode bonding material 34 is less than a predetermined strength at a predetermined temperature. In the case of this embodiment, the "predetermined temperature" is a temperature reached by heat transmitted from the heat transfer body 20. In the case of this embodiment, the positive electrode bonding material 32 and the negative electrode bonding material 34 are alloys having a melting point at the above-mentioned "predetermined temperature." In this embodiment, the positive electrode bonding material 32 and the negative electrode bonding material 34 are collectively referred to as "bonding material."

The insulating spacer 36 is a member having a cylindrical portion and an annular portion extending from one end of the cylindrical portion. The insulating spacer 36 provides insulation between the heat transfer body 20 and the compression coil spring 38.

The compression coil spring 38 is arranged between the positive electrode 22 and the negative electrode 24. Compression coil spring 38 applies a separation force to conductor member 30 . In the case of this embodiment, the "separation force" is a force in a direction in which the conductor member 30 joined to the positive electrode 22 and the negative electrode 24 separates from the positive electrode 22 and the negative electrode 24. The above-mentioned "predetermined strength" means strength to withstand separation force. That is, the positive electrode bonding material 32 and the negative electrode bonding material 34 cannot withstand the separation force when their temperature reaches a predetermined temperature.

The insulating plate 40 is a disc-shaped member with a hole in the center. The insulating plate 40 is placed on the compression coil spring 38. The insulating plate 40 provides insulation between the compression coil spring 38 and the conductor member 30.

The guide lead 42 is a cylindrical member. The guide lead 42 passes through the conductor member 30. The conductor member 30 that has received the separation force rises along the guide lead 42.

The positive pole side magnet 44 and the negative pole side magnet 46 generate magnetic force between the positive pole 22 and the negative pole 24 in advance. In the case of this embodiment, the positive pole side magnet 44 and the negative pole side magnet 46 are made of well-known samarium cobalt magnets.

The cylindrical body 48 is a rectangular cylindrical member whose edges are rounded. In the case of this embodiment, the material of the cylindrical body 48 is polyphenylene sulfide resin kneaded with glass filler. The cylindrical body 48 accommodates the heat transfer body 20 so that a portion thereof is exposed. The specific structure of the cylindrical body 48 will be described later.

The movement suppressor 50 is arranged inside the cylindrical body 48 . The movement suppressor 50 suppresses movement of the heat transfer body 20 inside the cylindrical body 48 . In the case of this embodiment, the movement suppressing body 50 includes an accommodation space forming body 70 and a filler 72. The accommodation space forming body 70 forms an accommodation space 158. The specific configuration of the accommodation space forming body 70 and the accommodation space 158 will be described later. The material of the filler 72 according to this embodiment is epoxy resin. The filler 72 is filled in a portion of the internal space of the cylindrical body 48 that is outside the accommodation space forming body 70 .

FIG. 3 is a diagram showing a situation in which the heat transfer body 20 according to this embodiment is connected to the positive electrode 22. In FIG. 3, the negative electrode 24 is not connected to the heat transfer body 20. Based on FIG. 3, the configuration of the heat transfer body 20, electrodes 22, 24, and thermally conductive materials 26, 28 according to this embodiment will be explained.

In the case of this embodiment, the heat transfer body 20 is provided with a guide lead holding recess 90 and an engagement step 92. In the case of this embodiment, the guide lead holding recess 90 is provided at the center of a predetermined surface of the heat transfer body 20. The annular portion of the insulating spacer 36 is fitted into the bottom of the guide lead holding recess 90. The end of the guide lead 42 is inserted into the cylindrical portion of the insulating spacer 36. As a result, the guide lead 42 is supported by the insulating spacer 36. The engagement step 92 is provided on the outer periphery of the surface of the heat transfer body 20 that will be described next. This surface is the surface that becomes the back surface when the surface where the guide lead holding recess 90 is provided is the front surface. The engagement step 92 is provided so as to surround the back surface thereof.

In the case of this embodiment, the positive electrode 22 has a joint portion 110, a heat conductor facing portion 112, and a terminal portion 114. The joining portion 110 is joined to the conductor member 30. The heat transfer body facing portion 112 is continuous with the joining portion 110 . The heat transfer body facing portion 112 faces the heat transfer body 20 . The terminal portion 114 is continuous with the heat transfer body facing portion 112 . The terminal portion 114 serves as a terminal for connecting the protection element 10 according to this embodiment to another component. Note that in the case of this embodiment, the configuration of the negative electrode 24 is exactly the same as the configuration of the positive electrode 22. Therefore, the detailed description thereof will not be repeated here.

In the case of this embodiment, the positive electrode thermally conductive material 26 is disposed between the surface of the heat transfer body 20 where the guide lead holding recess 90 is provided and the heat transfer body facing portion 112 of the positive electrode 22. Become. The negative electrode thermally conductive material 28 is arranged between the surface of the heat transfer body 20 where the guide lead holding recess 90 is provided and the heat transfer body facing portion 112 of the negative electrode 24 . In the case of this embodiment, the positive electrode thermally conductive material 26 and the negative electrode thermally conductive material 28 have a silver foil layer (not shown) and a solder layer (not shown). The silver foil layer is fixed to the surface of the heat transfer body 20. The solder layer is formed on the silver foil layer. Specific means for forming such thermally conductive materials are well known, and therefore detailed description thereof will not be repeated here.

FIG. 4 is a perspective view of the cylindrical body 48 according to this embodiment. The configuration of the cylindrical body 48 according to this embodiment will be explained based on FIG. 4.

In the case of this embodiment, the cylindrical body 48 has a body portion 130, a drop-off prevention portion 132, and a pair of engagement grooves 134, 134. The body 130 forms the space described next. The space includes the joint portion 110 and the heat conductor facing portion 112 of the positive electrode 22, the joint portion 110 and the heat conductor facing portion 112 of the negative electrode 24, the conductor member 30, the positive electrode bonding material 32, and the negative electrode bonding material 34. , the compression coil spring 38, the heat transfer body 20, and the movement suppressing body 50 are accommodated. Also accommodated are the insulating spacer 36, the insulating plate 40, the guide lead 42, the positive magnet 44, and the negative magnet 46. The fall prevention part 132 is arranged at the end of the inner circumferential surface of the body part 130. The drop-off prevention part 132 protrudes toward the space formed by the body part 130. This falling-off prevention portion 132 engages with the engagement step 92 of the heat transfer body 20 . Thereby, this falling-off prevention part 132 will prevent the heat transfer body 20 from falling off from the body part 130. The engagement groove 134 is provided near an end of the inner circumferential surface of the body portion 130 that is opposite to the end from which the drop-off prevention portion 132 protrudes.

FIG. 5 is a perspective view of the accommodation space forming body 70 according to this embodiment. The configuration of the accommodation space forming body 70 according to this embodiment will be explained based on FIG. 5.

The accommodation space forming body 70 according to this embodiment is made of polyphenylene sulfide resin mixed with glass filler. The housing space forming body 70 has a wall forming portion 150 and a pair of electrode contact portions 152 , 152 . The wall forming part 150 forms a wall surrounding the accommodation space 158. A lead through hole 160 is formed in the wall forming portion 150 . The guide lead 42 enters into the lead through hole 160. The electrode contact portions 152 , 152 protrude from both ends of the wall surface forming portion 150 . An electrode fitting groove 170 is formed in the electrode contact portions 152, 152. The positive electrode 22 and the negative electrode 24 are fitted into electrode fitting grooves 170 formed in the electrode contact parts 152, 152, respectively. Thereby, the electrode contact portions 152, 152 come into contact with the heat transfer body facing portions 112 of the electrodes 22, 24 inside the body portion 130, respectively.

[Description of manufacturing method]
The protection element 10 according to this embodiment is manufactured by the following procedure. First, a manufacturer manufactures components that constitute the protection element 10 according to this embodiment. At this time, a positive electrode thermally conductive material 26 and a negative electrode thermally conductive material 28 are formed on the heat transfer body 20. Methods for manufacturing these parts and forming the positive electrode thermally conductive material 26 and the negative electrode thermally conductive material 28 are well known. Therefore, their detailed description will not be repeated.

When the above-described component is manufactured, the manufacturer fixes the positive electrode 22 to the positive electrode thermally conductive material 26 formed on the surface of the heat transfer body 20. Further, the manufacturer fixes the negative electrode 24 to a negative electrode heat conductive material 28 formed on the surface of the heat transfer body 20. Since the positive electrode thermally conductive material 26 and the negative electrode thermally conductive material 28 each have a solder layer, it is possible to fix the positive electrode 22 and the negative electrode 24 to these solder layers by a well-known method. Thereby, the positive electrode thermally conductive material 26 and the negative electrode thermally conductive material 28 are connected to the heat transfer body 20 and the portions 112 of the positive electrode 22 and the negative electrode 24 that face the heat transfer body. After the positive electrode 22 and the negative electrode 24 are fixed, the manufacturer inserts the insulating spacer 36 into the guide lead holding recess 90 of the heat transfer body 20. The manufacturer then passes the compression coil spring 38 through the insulating spacer 36. The manufacturer then inserts one end of the guide lead 42 into the insulating spacer 36. When this is inserted, the manufacturer causes the guide lead 42 to penetrate the insulating plate 40 and the conductor member 30. Once the guide lead 42 passes through them, the manufacturer joins the conductor member 30 to the positive electrode 22 using the positive electrode bonding material 32 . The manufacturer also joins the conductor member 30 to the negative electrode 24 using the negative electrode bonding material 34 .

When the conductor member 30 is joined to the positive electrode 22 and the negative electrode 24, the manufacturer attaches a seal to the surface of the fall prevention portion 132 that faces the space formed by the body portion 130 (the surface on which the engagement step 92 of the heat transfer body 20 is placed). Apply epoxy resin before polymerization. Once the pre-polymerized epoxy resin has been applied, the manufacturer encases the heat transfer body 20 within the tube 48 . When the heat transfer body 20 is housed in the cylindrical body 48, the manufacturer covers the positive electrode 22, the negative electrode 24, and the conductor member 30 with the accommodation space forming body 70. As a result, the following items are arranged in the accommodation space 158 formed by the accommodation space forming body 70. These are a joint portion 110, a conductor member 30, a positive electrode bonding material 32, a negative electrode bonding material 34, an insulating spacer 36, a compression coil spring 38, an insulating plate 40, and a guide lead 42 of each of the positive electrode 22 and negative electrode 24. . When the accommodation space forming body 70 is covered, the manufacturer passes the other end of the guide lead 42 into the lead through hole 160 formed in the accommodation space forming body 70 . Further, the manufacturer fits the heat conductor facing portions 112, 112 of the positive electrode 22 and the negative electrode 24 into the electrode fitting grooves 170, 170 of the housing space forming body 70. Thereby, the electrode contact portions 152, 152 span the positive electrode 22 and the negative electrode 24. Next, the manufacturer places the positive pole side magnet 44 and the negative pole side magnet 46 on the electrode contact portion 152 of the accommodation space forming body 70. Next, the manufacturer fills the cylindrical body 48 with epoxy resin before polymerization. The epoxy resin is filled into the body 130 of the cylindrical body 48 . The filled epoxy resin presses the positive side magnet 44 and the negative side magnet 46 against the outer peripheral surface of the wall surface forming part 150 of the accommodation space forming body 70. Furthermore, the epoxy resin contacts the inner circumferential surface of the body 130 of the cylindrical body 48 and the outer circumferential surface of the accommodation space forming body 70. Furthermore, the epoxy resin is also filled into both pairs of engagement grooves 134, 134. Thereafter, when the polymerization of the epoxy resin is completed, the epoxy resin is cured. The epoxy resin applied to the surface of the drop-off prevention part 132 facing the space formed by the body part 130 is also cured. These epoxy resins become the filler 72. Thereby, the filler 72 comes into contact with the inner circumferential surface of the body portion 130 of the cylindrical body 48 and the outer circumferential surface of the accommodation space forming body 70 . As a result, the protection element 10 according to this embodiment is completed.

[Explanation of usage]
The protection element 10 according to this embodiment is used, for example, to protect a circuit that has become hot. The protection element 10 according to this embodiment is placed close to a heat source (not shown) that generates high temperature. The protection element 10 according to this embodiment is connected in series to, for example, a circuit that needs to cut off power supply. As power is supplied to the circuit, the protection element 10 according to this embodiment receives power. A current resulting from the electric power flows from the positive electrode 22 to the negative electrode 24 of the protection element 10 according to this embodiment. The current passes through the conductor member 30. The heat transfer body 20 receives thermal energy from the aforementioned heat source (not shown). Heat resulting from the thermal energy is transmitted from the heat transfer body 20 to the positive electrode 22 and the negative electrode 24. The heat transmitted to the positive electrode 22 and the negative electrode 24 is transmitted to the positive electrode bonding material 32 and the negative electrode bonding material 34. When the heat is transferred to the positive electrode bonding material 32 and the negative electrode bonding material 34, their temperatures rise. They melt when their temperature reaches the predetermined temperature mentioned above. When they melt, the compression coil spring 38 separates the conductor member 30 from the positive electrode 22 and negative electrode 24. As a result, current no longer flows from the positive electrode 22 to the negative electrode 24. When current no longer flows from the positive electrode 22 to the negative electrode 24, power to the circuit described above is cut off. As a result, the circuit is protected.

[Explanation of effects]
According to this embodiment, a protection element 10 suitable for use as a thermal fuse in a high temperature environment due to abnormal heat generation of a protected device is provided.

<Explanation of modification example>
The protection element 10 described above is exemplified to embody the technical idea of the present invention. The protection element 10 described above can be modified in various ways within the scope of the technical idea of the present invention.

For example, in the protection element 10 according to the present invention, the specific configuration for the heat transfer body 20 to transfer heat to either the positive electrode 22 or the negative electrode 24 is not limited to that described above. The protection element 10 according to the present invention does not need to include at least one of the positive electrode thermally conductive material 26 and the negative electrode thermally conductive material 28. Further, the positive electrode thermally conductive material 26 may be any material that has higher thermal conductivity than the air that contacts the heat transfer body 20 and the positive electrode 22. The negative electrode thermally conductive material 28 may be any material as long as it has higher thermal conductivity than the air that contacts the heat transfer body 20 and the negative electrode 24 . Furthermore, in the protection element 10 according to the present invention, one of the positive electrode 22 and the negative electrode 24 may be sufficiently separated from the heat transfer body 20.

Further, in the protection element 10 according to the present invention, the specific configurations of the falling-off prevention part 132 and the movement suppressing body 50 are not limited to those described above.

Further, the heat transfer body 20 according to the present invention can be made of a ceramic plate (for example, alumina, steatite, zirconia, aluminum nitride, silicon carbide, silicon nitride, etc.), an insulated metal plate, or a composite material in which ceramic powder is kneaded. Any material selected from the group consisting of a resin plate, a synthetic resin plate kneaded with frit glass, and a silicon plate may be used. Which of these materials should be used for the heat transfer body 20 should be appropriately selected based on requirements such as the temperature of the heat source that the protection element 10 according to the present invention is expected to be close to.

Further, the types of magnets used as the positive pole side magnet 44 and the negative pole side magnet 46 according to the present invention are not limited to samarium cobalt magnets. Examples of magnets used as the positive magnet 44 and the negative magnet 46 according to the present invention include alnico, ferrite, neodymium, and other magnetic materials.

Further, the material of the cylindrical body 48 according to the present invention is not limited to polyphenylene sulfide resin kneaded with glass filler. Examples of materials for the cylindrical body 48 according to the present invention include synthetic resins (for example, phenolic resin, polycarbonate, polyacetal, fluorine resin, polyamide, polyethylene, polypropylene, polyvinyl alcohol, polyvinylidene chloride, polyethylene terephthalate, polyvinyl chloride, Polystyrene, ABS resin, AS resin, acrylic resin, polyphenylene sulfide, polyether ether ketone, liquid crystal polymer, fluororesin, melamine resin, urea resin, epoxy resin, unsaturated polyester resin, alkyd resin, dialiphthalate resin, polyimide) , ceramics (eg, alumina, steatite, zirconia, aluminum nitride, silicon carbide, silicon nitride), insulated metal plates, and silicon plates. When the material of the cylindrical body 48 is a synthetic resin, the synthetic resin may be a mixture of ceramic powder, glass filler, and frit glass. Further, the synthetic resin does not need to be kneaded at all.

Further, the material of the filler 72 according to the present invention is not limited to epoxy resin. Examples of materials for the filler 72 according to the present invention include cement resin, silicone resin, urethane resin, polyamide resin, polyimide resin, and phenoxy resin. The material of the filler 72 according to the present invention may be a substance having a sealing effect other than these synthetic resins.

Further, the material of the accommodation space forming body 70 according to the present invention is not limited to polyphenylene sulfide resin kneaded with glass filler. Examples of materials for the accommodation space forming body 70 according to the present invention include synthetic resins (for example, phenol resin, polycarbonate, polyacetal, fluororesin, polyamide, polyethylene, polypropylene, polyvinyl alcohol, polyvinylidene chloride, polyethylene terephthalate, polyvinyl chloride). , polystyrene, ABS resin, AS resin, acrylic resin, polyphenylene sulfide, polyether ether ketone, liquid crystal polymer, fluororesin, melamine resin, urea resin, epoxy resin, unsaturated polyester resin, alkyd resin, dialiphthalate resin, polyimide ), ceramics (eg, alumina, steatite, zirconia, aluminum nitride, silicon carbide, silicon nitride), insulated metal plates, and silicon plates. When the material of the accommodation space forming body 70 is a synthetic resin, the synthetic resin may be a mixture of ceramic powder, glass filler, and frit glass. Further, the synthetic resin does not need to be kneaded at all.

10...Protective element 20...Heat conductor 22...Positive electrode 24...Negative electrode 26...Positive electrode thermally conductive material 28...Negative electrode thermally conductive material 30...Conductor member 32...Positive electrode bonding material 34...Negative electrode bonding material 36...Insulating spacer 38...Compression coil spring 40 ...Insulating plate 42...Guide lead 44...Positive side magnet 46...Negative side magnet 48...Cylindrical body 50...Movement suppressor 70...Accommodation space forming body 72...Filling material 90...Guide lead holding recess 92...Engagement step 110 …Joint portion 112…Heat conductor facing portion 114…Terminal portion 130…Body portion 132…Off-off prevention portion 134…Engagement groove 150…Wall surface forming portion 152…Electrode contact portion 158…Accommodation space 160…Lead through hole 170…Electrode Inset groove

Claims (4)

a pair of electrodes facing each other;
a conductor member disposed straddling between the pair of electrodes;
a bonding material that connects the conductor member to each of the pairs of electrodes so as to enable conduction;
an elastic body disposed between the pair of electrodes and applying a separating force to the conductor member;
The separation force is a force in a direction that causes the conductor member to separate from the pair of electrodes,
the bonding strength of the bonding material is below a predetermined strength at a predetermined temperature;
The predetermined strength is a protection element that is strong enough to withstand the separation force,
a heat transfer body connected to at least one of the pair of electrodes and transmitting the heat to at least one of the pair of electrodes when receiving heat;
a cylindrical body that houses the heat transfer body so that a part of the heat transfer body is exposed;
further comprising a movement suppressor disposed inside the cylindrical body and suppressing movement of the heat transfer body inside the cylindrical body,
The cylindrical body is
a body forming a space in which a portion of each of the pairs of electrodes, the conductor member, the bonding material, the elastic body, the heat transfer body, and the movement suppressor are accommodated;
A falling-off prevention part is provided to prevent the heat transfer body from falling off from the body,
The heat transfer body is made of one of the group consisting of a ceramic plate, an insulated metal plate, a synthetic resin plate mixed with any one of ceramic powder, glass filler, and frit glass, and a silicon plate. A protective element characterized by: The electrode is
a joint portion joined to the conductor member;
It has a heat transfer body facing portion that is connected to the joint portion and faces the heat transfer body,
The movement suppressor is
an accommodation space forming body that forms an accommodation space;
a filler disposed in a portion of the interior of the body that is outside the housing space forming body and in contact with an inner circumferential surface of the body and an outer circumferential surface of the housing space forming body;
The protection element according to claim 1, wherein the joint portion, the conductor member, the joint material, and the elastic body of each pair of electrodes are arranged in the housing space. The accommodation space forming body is
a wall surface forming part that forms a wall surface surrounding the accommodation space;
The protection element according to claim 2, further comprising an electrode contact portion that protrudes from an end of the wall surface forming portion and contacts the portion of the electrode facing the heat conductor inside the body portion. Claim further comprising: a thermally conductive material disposed between the heat transfer body and the portion of the electrode facing the heat transfer body and connected to the heat transfer body and the portion of the electrode facing the heat transfer body. 2. The protection element according to 2.

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