JP7089758B2 - Protective element - Google Patents

Description

The present invention relates to a protective element.

Patent Document 1 discloses an invention relating to a protective element. The protective element according to Patent Document 1 includes an insulating substrate, a first electrode, a second electrode, a third electrode, a fourth electrode, a resistor, low melting point soluble alloy pieces A and B, a flux, and the like. It is provided with an insulating layer. A first electrode, a second electrode, a third electrode, and a fourth electrode are provided on one side of the insulating substrate. A resistance is provided across the second electrode and the fourth electrode. A low melting point soluble alloy piece A is connected between the first electrode and the second electrode. A low melting point soluble alloy piece B is connected between the second electrode and the third electrode. Flux is applied to these low melting point soluble alloy pieces. The insulating layer covers one side of the insulating substrate.

The protective element disclosed in Patent Document 1 has a simple structure, is easy to manufacture, and has excellent operability.

Japanese Unexamined Patent Publication No. 10-116550

However, there is a need for further improvement in the possibility of insulation failure during operation. The present invention solves such a problem. An object of the present invention is to provide a protective element having a lower possibility of insulation failure during operation.

The protective element of the present invention will be described with reference to the drawings. It should be noted that the reference numerals in the drawings are used in this column for the purpose of assisting the 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-mentioned problems, according to a certain aspect of the present invention, the protective elements 10 and 310 include a substrate 40, a pair of electrodes 42 and 44, and a connecting body 56. The pair of electrodes 42, 44 is arranged on any surface of the substrate 40. The connecting body 56 connects between the pair of electrodes 42 and 44. The connection 56 is supplied with energy and melts when it reaches the melting point. The connecting body 56 is a conductor. The protective elements 10, 310 further include magnetic force generating units 32, 34, 334, 336. The magnetic force generating units 32, 34, 334, 336 generate magnetic forces in the directions described below. The direction intersects the direction described below. The direction is from one of the pair of electrodes 42 and 44 toward the other.

The connector 56 is supplied with energy and melts when it reaches the melting point. As a result of the dissolution, an arc may occur when the connector 56 ceases to connect between the pairs of electrodes 42, 44. The direction of the magnetic force generated by the magnetic force generating units 32, 34, 334, 336 is a direction intersecting the direction described below. The direction is from one of the pair of electrodes 42 and 44 toward the other. Since the direction of the magnetic force is the above-mentioned direction, when an arc is generated with the melting of the connecting body 56, the arc receives a Lorentz force. The arc that receives the Lorentz force flows in the direction described below. The direction intersects the direction in which the current flows. When the arc receives such a Lorentz force, the arc is cooled better than when it does not receive such a Lorentz force. If the arc is well cooled, it is less likely to have poor insulation than it would otherwise be. Thereby, it is possible to provide the protective elements 10, 310 which are less likely to cause insulation failure during operation.

Further, it is desirable that one of the pair of electrodes 42 and 44 described above has the one-side facing portion 70. The one-side facing portion 70 extends linearly along the surface on which the electrodes 42, 44 of the substrate 40 are arranged so as to face the other of the pair of the electrodes 42, 44 at a distance. In this case, it is desirable that the other side of the pair of electrodes 42 and 44 has the opposite side facing portion 72. The other-side facing portion 72 faces the one-side facing portion 70 of the pair of electrodes 42 and 44 at a distance. The other side facing portion 72 extends linearly along the direction in which the one side facing portion 70 extends. In this case, it is desirable that the connecting body 56 connects between the one-side facing portion 70 and the other-side facing portion 72 of the pair of electrodes 42 and 44. In this case, it is desirable that the magnetic force generating units 32, 34, 334, 336 have magnets 32, 34. The magnets 32 and 34 face the connecting body 56 at the electrodes 80 and 82. The electrodes 80 and 82 are located at any position between the one-side facing portion 70 and the other-side facing portion 72. The magnet 32 generates a magnetic force from one of the following two surfaces of the substrate 40 toward the other. These surfaces are the surface on which the pairs of electrodes 42 and 44 are arranged and the back surface of the surface on which the pairs of electrodes 42 and 44 are arranged.

The magnetic force generated by the magnets 32 and 34 is directed from one of the following two surfaces of the substrate 40 to the other. These surfaces are the surface on which the pairs of electrodes 42 and 44 are arranged and the back surface of the surface on which the pairs of electrodes 42 and 44 are arranged. As a result, the generated arc receives Lorentz force along the direction in which the one-side facing portion 70 and the other-side facing portion 72 of the surface of the substrate 40 extend. The one-side facing portion 70 extends linearly. The opposite side facing portion 72 extends linearly along the direction in which the one side facing portion 70 extends. As a result, the possibility of insulation failure is reduced as compared with the case described below. In that case, the one-side facing portion 70 and the other-side facing portion 72 do not extend linearly. This makes it possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

Alternatively, it is desirable that the magnets 32 and 34 described above are arranged so that any of the edges of the magnets 32 and 34 faces the connecting body 56 at the electrodes 80 and 82.

At the edges of the magnets 32 and 34, the magnetic flux density is higher than at the center thereof. As a result, the generated arc receives a stronger Lorentz force. The stronger Lorentz force cools the arc better than it would otherwise. If the arc is well cooled, it is less likely to have poor insulation than it would otherwise be. This makes it possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

Alternatively, it is desirable that the above-mentioned inter-electrode points 80 and 82 are places where any part of the edge of the connecting body 56 is arranged.

When the connecting body 56 melts, it tends to be any part of the edge of the connecting body 56 that connects the pair of electrodes 42, 44 to the end. When the points 80 and 82 between the electrodes are the places where any part of the edge of the connecting body 56 is arranged, the magnetic flux at the place where the pair of the electrodes 42 and 44 is connected to the end as compared with the case where it is not. It is more likely that the density will be higher. As the magnetic flux density increases, the generated arc receives a stronger Lorentz force. The stronger Lorentz force cools the arc better than it would otherwise. If the arc is well cooled, it is less likely to have poor insulation than it would otherwise be. This makes it possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

Alternatively, it is desirable that the protective element 10 described above further includes an insulator 36. The insulator 36 insulates the connecting body 56 and the magnet 32. The insulator 36 protects the magnet 32 when the connector 56 melts. In this case, it is desirable that the magnet 32 is arranged so as to be in contact with the connecting body 56 via the insulator 36.

The insulator 36 insulates the connecting body 56 and the magnet 32. This makes it possible to prevent current from flowing from the connecting body 56 to the magnet 32. The insulator 36 protects the magnet 32 when the connector 56 melts. This protects the magnet 32 from the arcs and heat generated when the connector 56 melts. The magnet 32 is arranged so as to be in contact with the connecting body 56 via the insulator 36. As a result, the arc receives a stronger Lorentz force as compared with the case where the magnet 32 is far away from the connecting body 56. That is, it is possible to prevent the current from flowing from the connecting body 56 to the magnet 32, to protect the magnet 32 from the arc and heat generated when the connecting body 56 melts, and the arc receives a strong Lorentz force. As a result, it is possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

Further, it is desirable that the above-mentioned magnetic force generating units 32, 34, 334, 336 have a pair of magnets 32, 34. The pairs of magnets 32 and 34 are arranged so as to be attracted to each other by magnetic force with the substrate 40, the pairs of electrodes 42 and 44, and the connecting body 56 sandwiched between them.

When the pair of magnets 32 and 34 are arranged so as to attract each other by magnetic force with the substrate 40, the pair of electrodes 42 and 44 and the connecting body 56 sandwiched between them, the magnetic force is generated by only one of the pair of magnets 32 and 34. The connecting body 56 receives a large magnetic force as compared with the above. When the connecting body 56 receives a large magnetic force, the generated arc receives a stronger Lorentz force as compared with the case where the connecting body 56 receives a large magnetic force. When the generated arc receives a strong Lorentz force, the generated arc is cooled better than it would otherwise be. If the arc is well cooled, it is less likely to have poor insulation than it would otherwise be. Thereby, it is possible to provide 10 protective elements having a lower possibility of insulation failure during operation.

Alternatively, the pair of magnets 32, 34 is arranged so that any part of one edge of the pair of magnets 32, 34 described above faces any part of the other edge of the pair of magnets 32, 34. Is desirable. In this case, it is desirable that the portion of one edge of the pair of magnets 32 and 34 facing the other edge of the pair of magnets 32 and 34 faces the connecting body 56 in the portion described below. The location is any location between the pairs of electrodes 42, 44.

When the pair of magnets 32 and 34 are arranged so as to attract each other by magnetic force with the substrate 40, the pair of electrodes 42 and 44 and the connecting body 56 sandwiched between them, the magnetic force is generated by only one of the pair of magnets 32 and 34. The connecting body 56 receives a large magnetic force as compared with the above. At the edges of the magnets 32 and 34, the magnetic flux density is higher than at the center thereof. Since the magnetic flux density is high, a larger magnetic force is received at the portion of the connecting body 56 facing the edges of the magnets 32 and 34. As a result, a larger magnetic force is received at the portion of the connecting body 56 facing the edges of the magnets 32 and 34 that are attracted to each other by the magnetic force. When it receives a larger magnetic force, the generated arc receives a stronger Lorentz force. As a result, it is possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

According to the present invention, it is possible to provide a protective element having a lower possibility of insulation failure during operation.

It is a circuit diagram of the secondary battery protection circuit which concerns on 1st Embodiment of this invention. It is a perspective view of the protection element which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the protection element which concerns on 1st Embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is a bottom view of the cutoff part which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the protection element which concerns on 2nd 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 designated by the same reference numerals. Their names and functions are also the same. Therefore, the detailed description of them will not be repeated.

<First Embodiment>
[Explanation of secondary battery protection circuit]
FIG. 1 shows a secondary battery protection circuit according to this embodiment. The secondary battery protection circuit according to this embodiment includes a load 200, a charging power supply 202, a switch 204, a control element 206, and a protection element 10. A well-known transistor is a kind of element that can be used as a switch 204. The control element 206 detects overcharging or overdischarging of the secondary battery 220. When the control element 206 detects at least one of them, the control element 206 transmits a switch-on signal to the switch 204. The switch 204 goes into the "on" state when it receives the switch-on signal. As a result, a current flows through the switch 204. The protective element 10 shuts off the secondary battery 220 from the load 200 or the charging power supply 202 when any of overcurrent, overcharge, and overdischarge occurs.

[Description of configuration]
FIG. 2 is a perspective view of the protection element 10 according to the present embodiment. The configuration of the protection element 10 according to the present embodiment will be described with reference to FIG.

The protective element 10 according to the present embodiment includes a main body portion 20, a case 22, and a lid 24. The main body 20 cuts off the circuit. The case 22 houses the main body 20. The lid 24 closes the opening of the case 22.

FIG. 3 is a diagram showing the configuration of the protection element 10 according to the present embodiment. In FIG. 3, the protective element 10 is shown in a disassembled state. FIG. 4 is a sectional view taken along the line AA of FIG. The configuration of the main body 20 according to the present embodiment will be described with reference to FIGS. 3 and 4.

The main body portion 20 includes a blocking portion 30, a case-side magnet 32, a lid-side magnet 34, a magnet insulator 36, and a magnet protector 38. The cutoff unit 30 enables the electric circuit to be energized until the electric circuit is cut off according to the control of the one that controls the protection element 10 according to the present embodiment (switch 204 in the case of the present embodiment). In the case of the present embodiment, the electric circuit is an electric circuit between the load 200 or the charging power source 202 and the secondary battery 220. The case-side magnet 32 and the lid-side magnet 34 generate a magnetic force. In the case of this embodiment, the north pole of the case-side magnet 32 faces the blocking portion 30. In the case of this embodiment, the S pole of the lid-side magnet 34 faces the blocking portion 30. As a result, the case-side magnet 32 and the lid-side magnet 34 are arranged so as to sandwich the substrate 40, the positive electrode 42, the negative electrode 44, and the connecting body 56 and attract each other by magnetic force. In the case of this embodiment, both the shape of the case-side magnet 32 and the shape of the lid-side magnet 34 are disk-shaped. The magnet insulator 36 protects the case-side magnet 32. The magnet protecting body 38 protects the lid-side magnet 34. In the present embodiment, the material of the magnet protective body 38 is an insulator.

FIG. 5 is a bottom view of the blocking portion 30. The bottom surface of the blocking portion 30 shown in FIG. 5 corresponds to the back surface as viewed from the blocking portion 30 shown in FIG. In this figure, a part of the blocking portion 30 is removed. The configuration of the blocking unit 30 according to the present embodiment will be described with reference to FIGS. 3 to 5. The blocking portion 30 includes a substrate 40, a positive electrode 42, a negative electrode 44, a pair of positive electrode terminals 46, a pair of negative electrode terminals 48, an intermediate electrode 50, a heating element 52, and a heating element terminal 54. A connecting body 56 and a protective resin 58 are provided.

A positive electrode 42, a negative electrode 44, an intermediate electrode 50, a heating element 52, a heating element terminal 54, a connecting body 56, and a protective resin 58 are fixed to the substrate 40.

The positive electrode 42 and the negative electrode 44 are a pair of electrodes according to the present embodiment. The positive electrode 42 and the negative electrode 44 are arranged on the surface of the substrate 40 having the largest area.

The pair of positive electrode terminals 46 is connected to the positive electrode 42. The positive electrode terminal 46 is a terminal for connecting an electric wire (in the case of the present embodiment, an electric wire for connecting the load 200 or the charging power supply 202 and the protection element 10) to the positive electrode 42.

The pair of negative electrode terminals 48 is connected to the negative electrode 44. The negative electrode terminal 48 is a terminal for connecting an electric wire (in the case of the present embodiment, an electric wire for connecting the secondary battery 220 and the protective element 10) to the negative electrode 44.

The intermediate electrode 50 is arranged on the surface of the substrate 40 on which the positive electrode 42 and the negative electrode 44 are arranged. The intermediate electrode 50 is arranged between the positive electrode 42 and the negative electrode 44. The intermediate electrode 50 is connected to the heating element 52 (see FIG. 3) via the through hole 60.

The heating element 52 is arranged on the back surface of the surface of the substrate 40 on which the positive electrode 42, the negative electrode 44, and the intermediate electrode 50 are arranged. The heating element 52 generates heat when it receives energy supply. In the case of this embodiment, the energy is supplied to the heating element 52 as electric power. In the case of the present embodiment, the lid-side magnet 34 comes into contact with the heating element 52 via the magnet protecting body 38.

The heating element terminal 54 is connected to the heating element 52 via a through hole (this through hole is different from the through hole 60 for connecting the intermediate electrode 50 and the heating element 52) (not shown). An electric wire (in the case of this embodiment, an electric wire for connecting the switch 204 and the protective element 10) is also connected to the heating element terminal 54. A current for supplying energy to the heating element 52 flows through the heating element terminal 54.

The connecting body 56 connects between the positive electrode 42 and the negative electrode 44. Along with this, the intermediate electrode 50 is connected to the positive electrode 42 and the negative electrode 44 by the connecting body 56. The connecting body 56 is a conductor. As a result, electricity can be supplied between the positive electrode 42, the negative electrode 44, and the intermediate electrode 50. The connection 56 is supplied with energy and melts when it reaches the melting point. As a result of melting, when the positive electrode 42, the negative electrode 44, and the intermediate electrode 50 are no longer connected, they are cut off. In the present embodiment, a flux (not shown) is applied to the surface of the connecting body 56. Since flux is well known, its detailed description will not be repeated here.

The protective resin 58 is a synthetic resin. The protective resin 58 covers the connecting body 56 and a flux (not shown) applied to the connecting body 56.

In the case of the present embodiment, the positive electrode 42 has a one-side facing portion 70. The one-side facing portion 70 extends linearly along the surface of the substrate 40 on which the positive electrode 42 and the negative electrode 44 are arranged. The one-side facing portion 70 faces the negative electrode 44 at a distance. In the case of the present embodiment, the negative electrode 44 has the opposite side facing portion 72. The opposite side facing portion 72 faces the one side facing portion 70 of the positive electrode 42 at a distance. The other side facing portion 72 extends linearly along the direction in which the one side facing portion 70 extends. In the case of the present embodiment, the connecting body 56 connects between the one-side facing portion 70 of the positive electrode 42 and the other-side facing portion 72 of the negative electrode 44.

The case-side magnet 32 is arranged so that its flat surface faces the connecting body 56. In the case of the present embodiment, the case-side magnet 32 is arranged so that any portion of the edge of the case-side magnet 32 faces the portion 80 between the positive electrode-side electrodes. In the case of the present embodiment, the portion 80 between the positive electrode side electrodes is adjacent to and connected to the one side facing portion 70 of the positive electrode 42 among the space between the one side facing portion 70 of the positive electrode 42 and the other side facing portion 72 of the negative electrode 44. It means a place where the edge of the body 56 is arranged. In the case of the present embodiment, the case-side magnet 32 is arranged so that any portion of the edge of the case-side magnet 32 faces the portion 82 between the negative electrode-side electrodes. In the case of the present embodiment, the portion 82 between the negative electrode side electrodes is adjacent to and connected to the other side facing portion 72 of the negative electrode 44 among between the one side facing portion 70 of the positive electrode 42 and the other side facing portion 72 of the negative electrode 44. It means a place where the edge of the body 56 is arranged. As a result, the case-side magnet 32 faces the connecting body 56 at the positive electrode-side electrode-to-electrode portion 80 and the negative electrode-side electrode-to-electrode-to-electrode portion 82. In the case of the present embodiment, the case-side magnet 32 is in contact with the connecting body 56 via the magnet insulator 36. In the case of the present embodiment, the case-side magnet 32 arranged in this way generates a magnetic force toward the other of the two surfaces described below in the substrate 40. These surfaces are a surface on which the positive electrode 42 and the negative electrode 44 are arranged and a back surface of the surface.

As described above, in the case of the present embodiment, the case-side magnet 32 and the lid-side magnet 34 are arranged so as to sandwich the substrate 40, the positive electrode 42, the negative electrode 44, and the connecting body 56 and attract each other by magnetic force. Further, the case-side magnet 32 and the lid-side magnet 34 are arranged so that the edge of the case-side magnet 32 faces the edge of the lid-side magnet 34. As a result, the edge of the case-side magnet 32 faces the edge of the lid-side magnet 34 at the positive electrode-side electrode-to-electrode portion 80 and the negative electrode-side electrode-to-electrode-to-electrode portion 82.

[Explanation of operation]
A current flows from the positive electrode 42 to the negative electrode 44 via the connector 56 until any of overcurrent, overcharge, and overdischarge occurs. When the control element 206 detects the overcharge or overdischarge of the secondary battery 220, the control element 206 transmits a switch-on signal to the switch 204. The switch 204 goes into the "on" state when it receives the switch-on signal. As a result, a current flows through the switch 204. When a current flows through the switch 204, energy is supplied as electric power to the heating element 52 of the protection element 10. When energy is supplied to the heating element 52, the heating element 52 generates heat. When the heating element 52 generates heat, the heat is transferred to the connecting body 56 through the substrate 40. As a result of heat transfer, the connection body 56 receives energy supply. When the connecting body 56 reaches the melting point as a result of receiving the energy supply, the connecting body 56 is melted. When the connecting body 56 is melted, the liquid connecting body 56 may gather at the edge of the connecting body 56 before melting. A current flows from the positive electrode 42 to the negative electrode 44 in the melted connector 56. As a result of the dissolution, an arc may be generated when the connecting body 56 does not connect between the positive electrode 42 and the negative electrode 44. The case-side magnet 32 faces the connecting body 56. The lid-side magnet 34 faces the connecting body 56 via the heating element 52 and the substrate 40. As a result, when an arc is generated, Lorentz force is applied to the arc. In the case of the present embodiment, the direction in which the Lorentz force is applied is the direction in which the one-side facing portion 70 of the positive electrode 42 and the other-side facing portion 72 of the negative electrode 44 extend in FIG. As a result, the generated arc is cooled better than when the Lorentz force is not applied. If the arc is well cooled, it is less likely to have poor insulation than it would otherwise be. The reason why the possibility of insulation failure is low is that the carbon line (linear carbon) is less likely to straddle between the positive electrode 42 and the negative electrode 44 as the arc is generated. The possibility that the carbon line straddles between the positive electrode 42 and the negative electrode 44 is low because the possibility that the carbon line is formed is low. The possibility that carbon lines are formed is low because the members around the arc generation location are less likely to be carbonized due to the rapid cooling of the arc. If no insulation failure occurs between the positive electrode 42 and the negative electrode 44, the electric circuit between the positive electrode 42 and the negative electrode 44 is cut off as the connector 56 melts. When the electric circuit between the positive electrode 42 and the negative electrode 44 is cut off, the load 200 or the charging power supply 202 and the secondary battery 220 are cut off.

[Explanation of effect]
As described above, in the protection element 10 according to the present embodiment, the generated arc receives the Lorentz force. The arc that receives the Lorentz force flows in the direction described below. The direction intersects the direction in which the current flows. When the arc receives such a Lorentz force, the possibility of insulation failure is lower than when the arc does not receive such a Lorentz force. This makes it possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

When the case-side magnet 32 and the lid-side magnet 34 are plate-shaped and their flat surfaces face the connecting body 56 as in the case of the present embodiment, the edge of the case-side magnet 32 and the lid-side magnet 34 At the edge of, the magnetic flux density is higher than at the center. As a result, the portion of the connecting body 56 arranged at the portion 80 between the positive electrode side electrodes and the portion arranged at the portion 82 between the negative electrode side electrodes are arranged at the portion receiving the magnetic force only from the surface facing the connecting body 56. It will receive a larger magnetic force than the part where it is. As a result, the generated arc receives a stronger Lorentz force. This makes it possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

The magnet insulator 36 insulates the connecting body 56 and the case-side magnet 32. This makes it possible to prevent current from flowing from the connecting body 56 to the case-side magnet 32. The magnet insulator 36 protects the case-side magnet 32 when the connector 56 melts. As a result, the case-side magnet 32 is protected from the arc and heat generated when the connecting body 56 melts. The case-side magnet 32 is arranged so as to be in contact with the connecting body 56 via the magnet insulator 36. As a result, the generated arc receives a stronger Lorentz force as compared with the case where the case-side magnet 32 is far away from the connecting body 56. That is, it is possible to prevent the current from flowing from the connecting body 56 to the case-side magnet 32, protect the case-side magnet 32 from the arc and heat generated when the connecting body 56 melts, and the generated arc is strong Lorentz. Receive power. As a result, it is possible to provide the protective element 10 which is less likely to cause insulation failure during operation.

<Second Embodiment>
The protection element 310 according to the present embodiment is used in the secondary battery protection circuit shown in FIG. 1 in place of the protection element 10 according to the first embodiment. Therefore, the function of the protective element 310 according to the present embodiment is the same as that of the protective element 10 according to the first embodiment.

FIG. 6 is a diagram showing the configuration of the protection element 310 according to the present embodiment. The protective element 310 according to the present embodiment includes a blocking portion 30, a case 22, a lid 24, a positive electrode side magnet 334, and a negative electrode side magnet 336. That is, the protection element 310 according to the present embodiment replaces the case side magnet 32, the lid side magnet 34, the magnet insulator 36, and the magnet protection body 38 of the protection element 10 according to the first embodiment, and the positive electrode side magnet 334. And a negative electrode side magnet 336. The protective element 310 according to the present embodiment does not include the magnet insulator 36 and the magnet protector 38. The positive electrode side magnet 334 is arranged along the side surface of the blocking portion 30 on the positive electrode side 42 side. The negative electrode side magnet 336 is arranged along the side surface of the blocking portion 30 on the negative electrode side 44 side. Both the positive electrode side magnet 334 and the negative electrode side magnet 336 are arranged so that their N poles face the heating element terminal 54 side. As a result, a repulsive force is generated between the positive electrode side magnet 334 and the negative electrode side magnet 336. Further, the positive electrode side magnet 334 and the negative electrode side magnet 336 generate a magnetic force in the direction from the heating element terminal 54 toward the intermediate electrode 50. This direction is also the direction of the magnetic force generated by the case-side magnet 32 and the lid-side magnet 34 according to the first embodiment, and is in a direction intersecting the direction from one of the pair of the positive electrode 42 and the negative electrode 44 toward the other. be.

The method of using the protective element 310 according to the present embodiment is the same as that of the protective element 10 according to the first embodiment. Therefore, the detailed explanation is not repeated.

In the case of the protective element 310 according to the present embodiment, when the connecting body 56 is melted, a current flowing from the positive electrode 42 to the negative electrode 44 flows through the melted connecting body 56. A magnetic force is applied to the melted connecting body 56 in the direction from the heating element terminal 54 toward the intermediate electrode 50. As a result, when an arc is generated, Lorentz force is applied to the generated arc. The direction of the Lorentz force is the direction in which the generated arc is separated from the substrate 40. Since the generated arc is subjected to a force in that direction, it is less likely that the carbon line will continue to connect between the positive electrode 42 and the negative electrode 44. Thereby, it is possible to provide the protection element 310 which is less likely to cause insulation failure during operation.

<Explanation of modified example>
The protective elements 10, 310 described above are exemplified in order to embody the technical idea of the present invention. The protective elements 10, 310 described above can be modified in various ways within the scope of the technical idea of the present invention.

For example, in the first embodiment, the entire circumference of the edge of the case-side magnet 32 and the entire circumference of the edge of the lid-side magnet 34 do not have to face each other. However, it is desirable that the case-side magnet 32 and the lid-side magnet 34 are arranged so that any part of the edge of the case-side magnet 32 faces any part of the edge of the lid-side magnet 34. The portion of the edge of the case-side magnet 32 does not have to face the connecting body 56, but it is desirable that the portion faces the connecting body 56. The case-side magnet 32 may face one of the positive electrode-side electrode-to-electrode 80 and the negative-negative electrode-to-electrode-to-electrode 82 and may not face the other. In that case, it is desirable that the case-side magnet 32 faces the positive electrode-side electrode-to-electrode portion 80 and the negative-electron-side electrode-to-electrode-to-electrode portion 82 so that the arc acts away from the positive electrode 42 and the negative electrode 44, that is, the pair of electrodes.

Further, the number of magnets in the protective element 10 according to the first embodiment and the protective element 310 according to the second embodiment is not particularly limited. The shape of the magnet is also not particularly limited. The protective element 10 according to the first embodiment and the protective element 310 according to the second embodiment may have a magnetic force generating unit instead of a magnet. This magnetic force generating unit generates a magnetic force in the direction described below. The direction is a direction in which the positive electrode 42 and the negative electrode 44 intersect in a direction from one to the other. An example of such a magnetic force generator is an electromagnet.

Further, the form of the positive electrode 42 and the negative electrode 44 is not limited to those described above.

10, 310 ... Protective element 20 ... Main body 22 ... Case 24 ... Lid 30 ... Block 32 ... Case side magnet 34 ... Lid side magnet 36 ... Magnet insulator 38 ... Magnet protector 40 ... Substrate 42 ... Positive electrode 44 ... Negative electrode 46 ... Positive electrode terminal 48 ... Negative electrode terminal 50 ... Intermediate electrode 52 ... Heat generator 54 ... Heat generator terminal 56 ... Connection body 58 ... Protective resin 60 ... Through hole 70 ... One side facing portion 72 ... One side facing portion 80 ... Positive electrode Location between side electrodes 82 ... Location between negative electrode side electrodes 200 ... Load 202 ... Charging power supply 204 ... Switch 206 ... Control element 220 ... Secondary battery 334 ... Positive electrode side magnet 336 ... Negative electrode side magnet

Claims (7)

With the board
With a pair of electrodes placed on any surface of the substrate,
A protective element including a connecting body that is a conductor that connects between pairs of electrodes and melts when the melting point is reached by receiving energy supply.
A protective element further comprising a magnetic force generating unit that generates a magnetic force in a direction intersecting the direction from one of the pair of electrodes to the other. One of the pair of electrodes has a one-sided facing portion that extends linearly along the surface on which the electrode of the substrate is arranged so as to face the other of the pair of electrodes at a distance.
The other side of the pair of electrodes faces the one side facing portion of one of the pair of electrodes at a distance, and has the other side facing portion extending linearly along the direction in which the one side facing portion extends. Ori,
The connecting body connects between the one-side facing portion and the other-side facing portion of the pair of electrodes.
The magnetic force generating portion faces the connecting body at a position between the electrodes, which is a position at any position between the one-side facing portion and the other-side facing portion, and the pair of the electrodes in the substrate is opposed to the connection body. The protective element according to claim 1, further comprising a magnet, which generates the magnetic force from one of the surface on which the electrode is arranged and the back surface of the surface on which the pair of electrodes is arranged to the other. The protective element according to claim 2, wherein the magnet is arranged so that any portion of the edge of the magnet faces the connecting body at the portion between the electrodes. The protective element according to claim 3, wherein the portion between the electrodes is a portion where any portion of the edge of the connecting body is arranged. The protective element further comprises an insulator that insulates the connector from the magnet and protects the magnet when the connector melts.
The protective element according to claim 2, wherein the magnet is arranged so as to be in contact with the connecting body via the insulator. The protective element according to claim 1, wherein the magnetic force generating unit has a pair of magnets arranged so as to sandwich the substrate, the pair of electrodes, and the connecting body so as to attract each other by magnetic force. The pair of magnets is arranged such that any part of one edge of the pair of magnets faces any part of the other edge of the pair of magnets.
At any point between the pairs of electrodes, the portion of one edge of the pair of magnets facing the other edge of the pair of magnets faces the connector. The protective element according to claim 6.

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