JPH1154005A - Current / temperature composite fuse and protection element for secondary battery using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a conventional thermal fuse, the temperature sensing element of the thermal fuse does not react only to the ambient temperature, but also generates heat when energized to the thermal fuse itself, and the current fuse is cut off. Before reaching the current, the current to the circuit could be interrupted. In addition, even if the impedance value once increases, the impedance value of the PTC element is reduced if the cause is eliminated, and the PTC element may be reconnected. A case is constituted by a case base made of a non-conductive material and a conductive terminal plate abutted on two spaced portions of the case base. A current fuse for overcurrent operation to be connected is arranged, and a temperature fuse element for releasing the connection conduction between the current fuse and the terminal plate by the repulsive force of the urging means whose suppression has been released due to the temperature rise and melting of the temperature sensing element is arranged. I do. Further, the terminal plate may be electrically connected in series between the safety valve of the battery and the top cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current fuse operated by an overcurrent for protecting a circuit of an electronic device,
The present invention relates to a combined current / temperature fuse in which a thermal fuse operated by an ambient temperature is housed and arranged in the same case. In addition, the present invention relates to a case where such a fuse is used as a protection element for a secondary battery.

[0002]

2. Description of the Related Art Normally, a current fuse cuts off a current supply to a protected circuit when a fuse element is blown by Joule heat caused by an overcurrent. A thermal fuse causes abnormal heat generation of a device or the like. When the temperature reaches a predetermined temperature, the heat-sensitive body is melted by this heat, and the current supply to the protected circuit is interrupted.

Conventionally, if only a current fuse is used, the circuit resistance may be increased due to an increase in the temperature of the device, and the circuit current may be reduced to break the circuit without blowing the current fuse. Combination was performed.

[0004] The market for small portable devices is rapidly expanding along with the reduction in size and weight of electronic devices. The emergence of high-density secondary batteries is one example.

[0005] Among the secondary batteries, the lithium ion secondary battery differs from the conventional secondary battery in that the average voltage is about 3.
Since it has a voltage of 6V, which is about three times the voltage of NiCd rechargeable batteries, it is possible to reduce the number of batteries required for devices, and it is now the mainstay of rechargeable batteries for small portable devices. It is getting.

By the way, in consideration of high energy density and battery characteristics of a lithium ion secondary battery, as a safety measure, a current fuse or a temperature fuse is connected in series to a battery circuit in the battery pack, or overcharging or overcharging is performed. For example, a discharge control circuit is provided.

[0007] In addition, a PTC (positive temp.) In which the impedance value rapidly rises above a predetermined temperature.
It is also common practice to connect an erasure coefficient element to the battery and connect it in series with the battery to protect the battery against overcurrent charging and external short circuit.

Taking a cylindrical battery as an example, a PTC element usually has an impedance value that is about a fraction of the internal impedance value of a lithium ion secondary battery, and a PTC element formed in a donut disk shape has a top shape. It is arranged to be connected in series between the cover and the safety valve.

As shown in FIG. 5, the PTC element a has a structure in which a thin conductive resin c having substantially the same shape as the nickel terminal plate b is bonded between two nickel terminal plates b. These through holes d near the center are for releasing gas from inside the battery when the safety valve operates.

[0010] Here, the impedance of the conductive resin c sandwiched between the two nickel terminal plates b of the PTC element a is substantially constant in a region below normal temperature. However, when the temperature of the conductive resin c rises due to an overcurrent or a rise in the battery temperature, the impedance value rises rapidly, and the conductive resin c cuts off the current to protect the battery. .

In a PTC element, if the impedance value once rises within a certain range of the inflow current or temperature range where the physical properties of the conductive resin do not change, the impedance value falls if the cause is eliminated. Has self-recovery.

[0012]

However, in the conventional thermal fuse used in combination with the current fuse, the current also flows through the thermal fuse itself, so that the temperature-sensitive body of the thermal fuse has an inconvenience depending on the current value. Was. In other words, the temperature sensing element generates heat not only in response to the ambient temperature but also when energized, causing a problem that the current to the circuit is cut off before the current fuse is cut off by overcurrent. . Therefore, when selecting the current fuse, it is necessary to consider not only the value of the current flowing through the battery circuit but also the characteristics of the thermal fuse.

The internal impedance of a lithium ion secondary battery is higher than that of a conventional secondary battery using an aqueous electrolyte, and at low temperatures, the conductivity of the organic electrolyte decreases. Tend to rise further.

For example, in the GSM system, which is the mainstream in portable terminals, the discharge current is a pulse discharge reaching 1 to 2 A, and heavy load discharge performance is required. If the internal impedance of the battery is large, the battery voltage drop due to discharge (the so-called I
R drop) is increased, and the discharge capacity is reduced as compared with the nominal capacity. However, this becomes remarkable at a low temperature at which the conductivity of the electrolytic solution decreases.

When a battery having a PTC element connected in series is discharged, a voltage drop due to the impedance of the battery causes a PT drop.
Since the voltage drop due to the C element is added, there is a problem that the time until the cut-off voltage is reached (the usable time of the device) is shorter than when the battery is used alone. Also,
When the temperature of the PTC element becomes high due to heat generation of the device or heavy load discharge, the impedance of the PTC element increases, and the voltage drop by the PTC element may be further increased.

Another problem is that the impedance value of the PTC element, which has increased due to heat generation due to an abnormality in the battery, decreases as the temperature of the PTC element decreases due to the removal of the heat generation factor. Finally, the impedance value of the PTC element decreases to a value before the rise.

Therefore, even after the temperature of the PTC element rises and the current is cut off, if the temperature drops and the impedance value of the PTC element drops, the battery is re-energized even if the abnormality of the battery is not eliminated. It will be.

In order to prevent the re-energization, it was necessary to connect a temperature fuse and the like in series to the circuit in addition to the PTC element.

[0019]

SUMMARY OF THE INVENTION Therefore, the present invention has been made to solve the above problems. That is, within one electric component,
When the temperature rises excessively, the temperature fuse mechanism, which is not electrically connected to the external terminal, disconnects the current fuse mechanism from the circuit to cut off the current, and for overcurrent, cuts off the current by operating the current fuse mechanism. The present invention provides a novel current / temperature composite fuse and a protective element for a secondary battery using the same.

[0020]

In order to achieve the above object, a combined current / temperature fuse of the present invention is configured as follows.

That is, a case is constituted by a case base made of a non-conductive material and a conductive terminal plate abutted on two spaced portions of the case base. And a temperature fuse element for releasing the connection conduction between the current fuse and the terminal plate by the repulsive force of the biasing means released by the temperature-sensitive melting of the temperature sensing element. It is characterized by being arranged.

At least one side of the current fuse is connected to a terminal plate via a contact, and the repulsive force of the biasing means of the thermal fuse element is applied to the contact.

Also, a non-conductive material is interposed in part or all of the contact surface between the case base and the terminal plate. Further, a through hole is formed through a substantially central portion of both terminal boards.

In the connection between the current fuse and the terminal plate, a connection piece connected to one end of the current fuse or one end of the contact is extended from the inside of the case to the outside of the terminal plate by a predetermined length. It is also possible to form a notch in the terminal plate substantially corresponding to the area of the terminal plate, and to bend this bent portion toward the terminal plate so as to be fixed flush with the terminal plate.

Further, the present invention is characterized in that the current / temperature composite fuse is electrically connected in series to a battery to form a protection element for a secondary battery. In this case, each terminal plate of the combined current / temperature fuse may be electrically connected in series between the battery safety valve and the top cover.

[0026]

According to the above construction, the present invention operates as follows. The current fuse operates in response to an overcurrent as in the related art, and cuts off current supply to the protected circuit.

On the other hand, when the thermosensitive element melts in response to an ambient temperature higher than the operating temperature, the suppression of the urging means is released, and the thermosensitive element operates repulsively. This repulsive force releases the connection between the current fuse and the terminal plate, and cuts off the current flowing between both terminal plates. When the current fuse and the terminal plate are connected using a contact, the above-described repulsive force may be applied to the contact.

Further, when the battery is electrically connected in series, the current fuse operates in response to the overcurrent and cuts off the current flowing through the battery. In addition, the temperature sensing element reacts and melts in response to an ambient temperature equal to or higher than the operating temperature, and the urging means operates to release the suppression of the urging means. The connection conduction with the connection terminal is released, and the current flowing to the battery is cut off.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a current / temperature composite fuse (hereinafter, abbreviated as “composite fuse”) of the present embodiment.
FIG. 2 is a partially cutaway perspective view showing the entirety of FIG. 2, FIG. 2 is a perspective view of a main part showing a connection state of a connection piece of the composite fuse of the present embodiment to a terminal plate, and FIG. FIG. 4 is a cross-sectional view, and FIG. 4 is an overall view showing a state where the composite fuse of the present embodiment is incorporated in a battery as a protection element for a secondary battery. The description of directions used below follows the form of expression in the drawings, but this is for convenience and does not limit the invention.

The composite fuse 1 of this embodiment mainly comprises a current fuse 3, a temperature fuse 4, and a case 2 for accommodating them. Case 2 is a case base 2
0 and two terminal plates 21 sandwiching the case base 20 facing each other.
a and 21b. The case base 20 has a thick disk shape made of a non-conductive material. In the present embodiment, the case base material 20 is made of a ceramic and has a diameter of 15 mm and a thickness of 2 mm.

The two terminal plates 21a and 21b are electrically conductive,
For example, the case base 20 is made of nickel and is formed in a disk shape.
Is arranged so as to abut substantially the entire surface or a part of the opposing surface 20a of the case base 20 so as to sandwich the case base 20. This terminal plate 2
Notches 22 are formed in 1a and 21b for connecting to connection pieces described later. In addition, a non-conductive material is interposed on one side of the terminal plates 21a and 21b that come into contact with the case base 20. In this embodiment, the non-conductive layer 23 is provided on one side of the terminal plates 21a and 21b instead of being formed as a separate body.
It is formed integrally.

The case 2 has terminal plates 21a, 21b
, A rectangular through hole 24 penetrating through a substantially central portion thereof. A substantially U-shaped space 26 is formed in the upper and right and left cases 2 surrounding the through hole 24 (in FIG. 1) and separated from the through hole 24.

The current fuse 3 is disposed in a space on the right side (in FIG. 1) in the case 2 separated by the through hole 24. The configuration itself of the current fuse 3 is a conventional technique, and is composed of a fuse element made of a fusible material that is blown by an overcurrent and connection pieces connected at both ends thereof. The lower connection piece is on the back side of the case 2 (the back side in FIG. 1).
The rear terminal connection piece 31 is connected to the back terminal plate 21a, and the upper connection piece forms a conductive plate 30 extending horizontally leftward in the space above the through-hole 24. In the present embodiment, the rating of the fuse element 32 is 5V-5.
A is set.

The conductive plate 30 is disposed so as to lie in the upper space (in FIG. 1) in the case 2 separated by the through hole 24, and the right end 30 a is connected to the fuse element 32.

The left end 30b of the conductive plate 30 is connected to a front terminal plate 21b, which is a terminal plate on the front side of the case 2 (front side in FIG.
Is connected to the front terminal connecting piece 25 connected to the terminal. As a result, the two terminal boards 21 are electrically connected through the series connection of the back terminal connection piece 31, the fuse element 32, the conductive plate 30, the contact 46, and the front terminal connection piece 25.

In the connection between the front terminal connecting piece 25 and the front terminal board 21b, as shown in FIG.
To the non-conductive layer 23 disposed inside the front terminal plate 21b.
A predetermined length is extended outward through the opening formed in the above. A notch 22 having a size substantially corresponding to the area of the extension 25a of the front terminal connecting piece 25 from this opening is formed in the front terminal plate 21b.
Are formed on the front terminal plate 21b.
Side terminal board 21b by welding means such as solder.
And is fixed in a state of conduction. At this time, since the thickness of the front terminal connection piece 25 and the thickness of the front terminal plate 21b are formed to be substantially the same, this portion can be finished flush when bent and fixed.

The back terminal connecting piece 31 and the back terminal plate 21a
The connection is also made with the same configuration as described above. The temperature fuse 4 includes a temperature sensing element 40 and a temperature sensing element filling cylinder 4.
1, a lock pin 44, a coil spring 45 as a biasing means, and a contact 46.

The thermal fuse 4 is disposed in the space on the left side of the case 2 separated by the through hole 24. When the suppression of the coil spring 45 is released by the melting of the temperature sensing element 40, the thermal fuse 4 is activated. The repulsive force is applied to the contact 46 to release the contact conduction between the contact 46 and the front terminal connecting piece 25 and the conductive plate 30.

That is, in such a configuration, the strip-shaped contacts 46 are arranged so as to bridge between the conductive plate 30 and the front terminal connecting piece 25 and to be in contact with each other. At a predetermined portion on the lower surface side of the contact 46, a bar-shaped locking pin 44 extending substantially vertically downward is attached, and at the tip thereof, an enlarged diameter portion 44a for locking is formed. The tip portion including the enlarged diameter portion 44a is buried in the thermosensitive body filling cylinder 41 arranged below.

The thermosensitive body filling cylinder 41 has a bottomed cylindrical shape, and the upper space thereof is filled with a thermosensitive body 40 (in this embodiment, a low melting point alloy having a melting point of about 130 ° C. is used). An inflow space 42 into which the melted temperature sensing element 40 flows is formed in a lower portion communicating with the upper space.

A coil spring 45 is arranged between the contact 46 and the thermosensitive body filling cylinder 41 in a state that the coil spring 45 is mounted around the locking pin 44. Then, in a state where the coil spring 45 is compressed by a certain amount, the distal end of the locking pin 44 is inserted and buried in the thermosensitive body and held by this hardening fixing force, thereby suppressing the repulsive operation of the coil spring 45. doing.

Further, an inner flange 43 is formed at the upper end opening edge of the thermosensitive element filling cylinder 41 to prevent the thermosensitive element 40 from coming out upward. The inner diameter of the inner flange 43 is set smaller than the diameter of the enlarged diameter portion 44a at the tip of the locking pin 44.

The present embodiment configured as described above operates as follows. First, since the current fuse 3 connects the front and back terminal plates 21a and 21b in series, if the current flowing between the both terminal plates 21a and 21b indicates an overcurrent value, the fuse element 32 is blown to cut off the current. Shut off supply.
This operation is similar to the operation of a conventional current fuse.

Next, separately from the heat (Joule heat) generated from the fuse element 32, when the temperature sensing element 40 of the temperature sensing element filling cylinder 41 reacts to the rise in the surrounding temperature and reaches the operating melting temperature. Then, the temperature sensing element 40 melts and flows into the inflow space 42. As a result, the holding of the locking pin 44 due to the hardening of the temperature sensing element 40 is released, and the suppressed coil spring 45 rebounds, and the repulsive force makes contact with the front terminal connecting piece 25 and the conductive plate 30. Contact 46
Is blown off and the current supply is cut off.

After the operation of the thermal fuse, the contact 46 fixed to the locking pin 44 by the locking force of the enlarged diameter portion 44a of the locking pin 44 to the inner flange 43 and the expanding force of the coil spring 45. Are detached from the connection pieces and the conductive plate 30 and are held in a state of not contacting them (see FIG. 3). Further, since the inside of the case 2 of both terminal boards is covered with the non-conductive layer, the contact 46 after the operation is
It does not come into contact with the terminal plates 21a and 21b to be re-conductive.

Therefore, the current flowing through the composite fuse 1 is cut off due to an overcurrent or a rise in temperature, and once the current is cut off, it is not possible to conduct electricity again. Also, when the internal pressure of the battery rises and the safety valve is opened, the through hole 24 provided in the case 2 serves as a gas vent hole for releasing gas or the like from the inside of the battery.

Next, the case where the composite fuse 1 of this embodiment is used as a protection element for a secondary battery will be described. [Examples 1 to 5] The composite fuse 1 according to this embodiment was tested under the conditions of Examples 1 to 5. PTC element (battery diameter 18
The results are shown in Table 1 together with the results of comparison with those for millimeters (manufactured by Raychem).

[0048]

[Table 1] The composite fuse 1 of the present embodiment operated effectively against overcurrent, and did not conduct again after the operation. In particular, even when a large current is input as in the fourth and fifth embodiments, the PTC
The element was not destroyed (burned) like the element.

[Examples 6 to 12] Next, as shown in FIG. 4, the composite fuse 1 obtained in this embodiment is used as a protection element for a lithium ion secondary battery in a cylindrical 18650 size lithium ion secondary battery. 5 incorporated. That is, in the battery manufacturing process, an electrode element (not shown) was inserted into the battery can 50, and one negative electrode lead of the electrode element was connected to the inner bottom of the can. Subsequently, after drawing is performed on the upper part of the battery can 50 and a gasket 51 is filled therein, a predetermined amount of an electrolyte is injected, and a safety valve 52 (a mechanism for interrupting a current by activation is connected to a positive electrode lead (not shown)). The composite fuse 1 and the top cover 53 were stacked in this order, and the upper portion of the battery can was crimped to complete the lithium ion secondary battery 5.

For comparison, a battery incorporating a PTC element (for a battery diameter of 18 mm, manufactured by Raychem) was also manufactured. In Example 6, the impedance of the element itself at 1 KHz was measured.

In the discharge capacity tests of Examples 7 to 9,
At 23 ° C., constant voltage charging was performed at an upper limit voltage of 4.2 V, and charging was performed at 500 mA for 8 hours. Subsequently, the battery after charging was stored for 3 hours in a constant temperature bath set at a discharge test temperature, and was discharged to a final voltage of 2.5 V in the constant temperature bath.

In the ninth and tenth embodiments, the discharge mode of the GSM type portable terminal (two in series) was discharged to a cutoff voltage of 2.5 V corresponding to the load per battery. In the measurement of the cycle maintenance ratio in Example 11, the upper limit voltage was set to 4.2.
V, the lower limit voltage was set to 2.5 V, the charge / discharge cycle was repeated at 2.5 W, and the cycle retention rate was calculated from the discharge capacity at the 100th cycle when the discharge capacity at the second cycle was 100%.

In Example 12, one battery with a 50% discharge depth was
After heating to 60 ° C. and holding for 1 hour, the battery naturally cooled to room temperature was disassembled, and the conduction of the composite fuse 1 and the PTC element was examined.

Table 2 shows the results of the test.

[0055]

[Table 2] From Example 6, the impedance of the composite fuse 1 of the present embodiment was lower than that of the PTC element.

Further, in any of the discharge tests from Examples 7 to 10, the lithium-ion secondary battery 5 incorporating the composite fuse 1 of the present embodiment showed an improvement in the discharge capacity as compared with the product using the PTC element. Was done.

Further, from Example 11, the charge / discharge cycle maintenance ratio of the battery was equal to or higher than that of the product using the PTC element. In addition, the lithium ion secondary battery 5 incorporating the composite fuse 1 of the present embodiment from Example 12
As the battery temperature rose, the safety valve was activated to release gas from the battery. In addition, as the temperature of the composite fuse 1 rises, the temperature sensing element melts and the conduction is effectively activated, and it does not conduct again after cooling.

[0058]

[Possibility of Other Embodiments] In the present embodiment, the case is formed in a disk shape. However, in the case of a rectangular battery or the like, it is possible to appropriately change the case. Further, the through hole 24 penetrating in a rectangular shape is provided at a substantially central portion of the case 2.
The shape and arrangement location of 4 are not limited to this. Therefore, for example, it may be attached to the can bottom where the safety valve is not arranged, and in this case, the through hole 24 provided in the case 2 may be omitted.

The arrangement of the current fuse 3 and the urging means in the case 2 is not limited to the present embodiment. In addition, two terminal boards 21
Although a and 21b face each other, it is not essential to make them face each other, and the terminal plates 21a and 21b have substantially the same shape as the case 2, but are not limited thereto, and the shapes may be different from each other. .

The method of connecting the connection pieces to the terminal plates 21a and 21b is not limited to the present embodiment, but may be different from that of the present embodiment, for example, by a conductor.

The shape of the thermosensitive body filling cylinder 41 is not limited to the present embodiment, but may be any as long as the thermosensitive body 40 can be held inside. Therefore, it is possible to form the thermosensitive body filling cylinder 41 integrally with the case 2, and the same applies to the inflow space 42.

The temperature sensing element 40 is not limited to the present embodiment, but may be any element as long as it releases the locking pin 44 on which a biasing force acts at a predetermined temperature. Therefore, depending on the setting of the shape retention strength, melting temperature, etc., an organic compound such as a thermoplastic resin or a paraffin wax composed of a single or a plurality of mixtures, an inorganic compound such as glass, a simple metal such as tin or lead, or an intermetallic It is also possible to use a compound, a metal oxide, or the like.

In the present embodiment, the thermosensitive element filling cylinder 41 is repelled in the upward state, but can be repelled even in the horizontal state. When a conductive substance is used as the temperature sensing element 40, the outflow to the outside of the temperature sensing element filling cylinder 41 is suppressed, and the conductive temperature sensing element 40 is used after the repulsion operation.
To prevent re-conduction.

In addition, the shape of the lower end of the locking pin 44 buried in the temperature sensing element 40 is also increased in this embodiment so that it does not fall out of the upper end opening edge of the temperature sensing element filling cylinder 41 after operation. Although 44a is provided, it is not limited to this. Therefore, the enlarged diameter portion 44a may be appropriately changed or may be omitted.

Further, in this embodiment, the connection between the connection piece and the conductive plate 30 and the contact is released by the repulsion operation. However, the connection between the connection piece and the conductive plate 30 and the contact may be released. Good (not shown).

In addition, when the composite fuse 1 is used as a protection element of a secondary battery, the method of installation, the installation site, the shape of the battery, and the type of the secondary battery are not limited to the present embodiment. It can also be incorporated in the secondary battery.

[0067]

[Effect] Since the present invention is configured as described above,
The following effects are obtained. That is, since the temperature fuse is not connected to the circuit, only the current flowing in the circuit needs to be considered when selecting the current fuse.
As in the prior art, it is possible to avoid interruption of the battery pack circuit due to malfunction of the thermal fuse.

In the same case 2, the functional part of the current fuse and the functional part of the thermal fuse are arranged independently without being affected by each other, and both functions are combined.
Since one electric component is formed, it can be formed much smaller than before. Therefore, in recent years, the range of application to various electric devices in which the size of electric circuit boards is remarkably reduced,
It is a revolutionary effect that spreads dramatically.

In particular, when the battery is electrically connected in series, the impedance of the entire fuse can be reduced as compared with the PTC element. Can be suppressed. Also, the current fuse side operates in response to overcurrent,
The current flowing through the battery can be reliably shut off, and there is almost no increase in impedance due to a rise in temperature of the device. On the other hand, the temperature fuse side operates only at an abnormal temperature without being affected by the current value, and can cut off the electrical connection of the current fuse and cut off the current supply to the battery circuit.

Further, the composite fuse according to the present invention is:
Unlike the PTC element, the impedance value does not decrease again after the current is cut off, so that the current is not re-energized. Therefore, it is possible to prevent erroneous use such as charging of a battery or a battery pack that has been interrupted once.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing the entire composite fuse of the present embodiment.

FIG. 2 is a perspective view of a main part showing a connection state of a connection piece of the composite fuse of the embodiment to a terminal plate.

FIG. 3 is a partial cross-sectional view of the composite fuse of the embodiment.

FIG. 4 is an overall view showing a state in which the composite fuse of the present embodiment is incorporated in a battery as a protection element for a secondary battery.

FIG. 5 is a perspective view schematically showing a conventional PTC element.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 1 Current / temperature composite fuse ("composite fuse") 2 Case 20. Case base 20a .. Opposite surface 21a. Back terminal plate (terminal plate on back side of case) 21b. Front terminal plate (terminal plate on case front side) 22. Notch 23, non-conductive layer 24, through hole 25, front terminal connection piece 25a, extension 26, space 3 current fuse 30, conductive plate (upper connection piece) 30a, right end (conductive plate) 30b, left end ( Conductive plate) 31. Back terminal connecting piece (lower connecting piece) 32. Fuse element 4. Thermal fuse 40. Thermosensitive body 41. Thermosensitive body filling cylinder 42. Inflow space 43. Inner flange 44. Locking pin 44a. Diameter 45 / Coil spring 46 / Contact 5 Lithium ion secondary battery 50 / Battery can 51 / Gasket 52 / Safety valve 53 / Top cover

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[Procedure amendment]

[Submission date] July 31, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (7)

[Claims] 1. A case comprising: a case base made of a non-conductive material; and a conductive terminal plate abutted on two spaced portions of the case base. And a temperature fuse element for releasing the connection conduction between the current fuse and the terminal plate by the repulsive force of the biasing means released by the temperature-sensitive melting of the temperature sensing element. A current / temperature composite fuse characterized by being arranged. 2. The method according to claim 1, wherein at least one side of the current fuse is connected to a terminal plate via a contact, and a repulsive force of a biasing means of the thermal fuse element is applied to the contact. Item 1. A current / temperature composite fuse according to Item 1. 3. The combined current / temperature fuse according to claim 1, wherein a non-conductive material is interposed in part or all of the contact surface between the case base and the terminal plate. 4. The combined current / temperature fuse according to claim 1, wherein a through hole is formed through a substantially central portion of both terminal boards. 5. In connecting the current fuse to the terminal plate, a connecting piece connected to one end of the current fuse or one end of the contact is extended from the inside of the case to the outside of the terminal plate by a predetermined length. A notch portion substantially corresponding to the area of the portion is formed in the terminal plate, and the extended portion is bent toward the terminal plate and fixed to be flush with the terminal plate. 4. The combined current / temperature fuse according to claim 2, 3, or 4. 6. A protection element for a secondary battery, wherein the combined current / temperature fuse according to any one of claims 1 to 5 is electrically connected in series to a battery. 7. The current / temperature composite fuse according to claim 1, wherein each terminal plate is electrically connected in series between the safety valve of the battery and the top cover. Protection element for a secondary battery.