WO2002086927A1

WO2002086927A1 - Safety device

Info

Publication number: WO2002086927A1
Application number: PCT/JP2002/003687
Authority: WO
Inventors: Hideaki Takeda
Original assignee: Uchiya Thermostat Co., Ltd.
Priority date: 2001-04-20
Filing date: 2002-04-12
Publication date: 2002-10-31
Also published as: JP2002319343A; JP4301744B2

Abstract

A safety device (15) capable of surely lasting the opened state of a contact produced when a trouble occurs, wherein a fixed contact (18) and a movable contact (20) and installed in a body housing (16), the end part upper surface of a movable plate (19) having the movable contact (20) is formed in a wide contact surface (22), a thermoplastic resin member (25) is stuck on the rear surface of a cover member (24) covering the body housing (16) and, in an ordinary rated operation, the opening and closing operations of the contacts are repeated by the inverse and return operations of a bimetal (23) according to the increase and decrease of an ambient temperature and, in a special abnormal state, the contacts are opened by the inverse of the bimetal (23) and the contact surface (22) at the end part of the movable plate (19) overheated by a special abnormality presses the thermoplastic resin member (25) against the rear surface of the cover member (24), the thermoplastic resin member (25) is fused to the contact surface (22) and stuck to the rear surface of the cover member (24), whereby, since the contact surface (22) is fixed to the cover member (24), the contacts are not closed even if the bimetal (23) is forced to be inverted and returned by the lowering of the ambient temperature.

Description

Two-letter codes and other abbreviations are issued periodically

“Codes and abbreviations” at the beginning of each PCT Zet

Guidance Notes ”.

(57) Abstract: To provide a safety device for surely maintaining the open state of a contact generated at the time of abnormality. The safety device 15 has a fixed contact 18 and a movable contact 20 in a main body housing 16, and the upper end of a movable plate 19 having a movable contact 20 is formed with a wide contact surface 22. A thermoplastic resin film 25 is adhered to the back surface of the cover member 24 that covers the housing 16. During normal rating operation, the switching operation of the contacts was repeated due to the reversal and return operation of the bimetal 23 corresponding to the rise and fall of the ambient temperature. The contact surface 22 at the end of the movable plate 1 9 presses the thermoplastic resin member 25 against the cover member 24, and the thermoplastic resin member 25 welds to the contact surface 22 and the cover member 2 4 Adhere to the back. After that, even if the bimetal 23 attempts to return to the inverted state due to a decrease in the ambient temperature, the contact surface 22 is fixed to the cover member 24 and the contact does not close. Specification

Technical field

The present invention relates to a safety device used for, for example, a secondary battery, and more particularly, to a safety device for surely maintaining an open state of a contact that has occurred at the time of abnormality. Background art

Conventionally, there is a safety device that opens and closes the contacts of the current-carrying path in response to the ambient temperature in order to protect the main unit and internal circuits from overcurrent and overheating. In general, there are various types of these safety devices.

For example, when the ambient temperature exceeds a certain temperature, the contact is cut off and the current is cut off. A manual reset type that once opened, holds the open state and returns to the closed state only manually, and a self-holding type that once opened, prevents the open state from returning due to heat generated by resistance. and so on. An element that performs the opening operation only once is a fuse.

By the way, as an abnormal condition that requires a safety device, for example, in the case of a rechargeable battery that is a rechargeable battery, an excessive short-circuit current due to a short circuit between the battery terminals, There is abnormal heat generation. It is also assumed that similar phenomena will occur due to misuse. It is not desirable to reuse a secondary battery that has passed such an abnormal situation from the viewpoint of safety. Therefore, after such an abnormal situation occurs, the built-in safety device is operated to open the contacts of the electrical circuit, and this open state is made permanent to reuse the main unit (rechargeable battery in this example). Ban Often the method is taken.

In this case, the fuse alone is used as a safety device, and the fuse is an open operation due to melting, so if an open operation is performed once for an abnormality that is not an abnormal abnormality and that occurs near the normal rating, it will return as it is In order to return the contacts to the closed state and reuse the main unit, a new fuse needs to be replaced, which is troublesome.

The manual reset type described above can be said to be highly repetitive and safe because it is manual.However, depending on the conditions at the time of return, there may be dangers and it is not generally safe. Also have. In addition, the manual reset type has a large number of parts and tends to be large, which causes a factor to increase the product cost. The self-holding type can maintain the open state as long as the power supply is connected.However, even in the open state, the current for self-holding flows separately. In this regard, the structure requires further consideration for safety.

Therefore, when various points are integrated, the automatic reset type is the most convenient. In this case, the danger is avoided by repeating the opening and closing of contacts for abnormalities near the normal rating, and for extreme abnormalities, it does not return to the closed state after one or more switching operations. It is desirable to have a configuration.

Figs. 8 (a) and 8 (b) are side sectional views showing examples of the configuration of safety devices proposed to meet such requirements. Both figures (a) and (b) show the state in which the movable contact 2 comes into contact with the fixed contact 1 and the contact in the current path is closed. The movable contact 2 is attached to one end of a bimetal 3, and the fixed contact 1 is attached to one end of a metal fixed support member 4. The other ends of the bimetal 3 and the metal fixed support member 4 are connected to external terminals 5a and 5b, respectively. A recess 6 is formed on the inner surface of the housing of the housing at a position facing the tip of the bimetal 3 where the movable contact 2 is provided, and the recess 6 is filled with a temperature-sensitive fusible material 7. The contact of this safety device opens and closes depending on the ambient temperature during normal rated use. Then, when the movable contact 2 is opened and one end of the bimetal 3 is lifted upward, the temperature-sensitive fusible body 7 restrains the raised one end of the bimetal 3 to an appropriate position. On the other hand, when the device is overheated due to an abnormal condition and one end of the bimetal 3 is lifted upward and the movable contact 2 is opened, the heat from the overheated one end of the bimetal 3 melts the heat-sensitive fusible material 7 and the concave 6 Thus, one end of the bimetal 3 is fitted into and engaged with the concave portion 6 without being suppressed by the temperature-sensitive fusible material 7. The engagement between the one end of the pie metal 3 and the recess 6 does not come off once engaged, so that even if the ambient temperature drops and the bimetal 3 attempts to perform the return inversion operation, it cannot be deformed and the contact is opened. State is permanent.

FIG. 9 (a) is a side sectional view showing another example of the safety device, and FIG. 9 (b) is an enlarged view of the A-I 'section in the direction of the arrow. In the safety devices shown in FIGS. 3A and 3B, the movable contact 9 comes into contact with the fixed contact 8 and the contact of the current path is in a closed state. The movable contact 9 is attached to one end of the bimetal 10, and the fixed contact 8 is attached to one end of the metal fixed support member 11. The other ends of the bimetal 10 and the metal fixed support member 11 are connected to external terminals 12a and 12b, respectively. A protrusion 14 integrally formed with the main body housing 13 is provided on the inner surface of the thermoplastic main body housing 13 at a position facing the front end of the bimetal 10 on which the movable contact 9 is provided. I have.

In this safety device, the contacts open and close depending on the ambient temperature during normal rated use. Then, even if the movable contact 9 is opened and one end of the bimetal 10 is lifted upward, it merely touches the projection 14, and when the ambient temperature decreases, the movable contact 9 returns to the closed position again. On the other hand, when the device is overheated due to an abnormal condition and one end of the bimetal 10 is lifted upward and the movable contact 9 is opened, the heat from the overheated one end of the bimetal 10 melts the thermoplastic protrusions 14. , One end of bimetal 10 4 is fused to the body housing 13. As a result, even if the ambient temperature drops and the bimetal 10 attempts to perform the return inversion operation, it cannot be deformed, and the open state of the contact is permanent. '

There are several problems with the safety device of the prior art described above. The first problem is the difficulty in realizing it. For example, the method of locking one end of the bimetal 3 in the concave portion 6 from which the temperature-sensitive fusible material 7 has been removed by the melting described above requires advanced technology to properly adjust the balance between the insertion and the locking operation, and is difficult to realize. It is. The second problem is that there is concern about the structure of the safety device. For example, the method of fusing one end of the bimetal 10 to the main body housing 13 by melting the above-mentioned thermoplastic protrusions 14 is insecure in the strength of the fusion due to the small protrusions, and a permanent and reliable open state is required. In such cases, the structure of the safety device remains questionable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a safety device that reliably keeps the open state of a contact point generated at the time of a special abnormality in view of the above-mentioned conventional circumstances. Disclosure of the invention

The safety device according to the embodiment of the present invention includes a switch unit that opens and closes an electric circuit by moving and contacting a fixed contact by a bimetal that reverses a warping direction according to an ambient temperature rising and falling a set temperature. A safety device, comprising a movable plate provided with a movable contact point, which is formed on the opposite side of the movable contact from the movable contact, and abuts against the back surface of a cover member that covers the switch when the contact of the switch is opened. A contact surface that presses against the back surface of the force bar member, and an insulating thermoplastic resin member that is disposed between the contact surface and the back surface of the cover member. The contact of the switch portion is opened by reversing the warping direction of the bimetal, and the abutting surface of the distal end of the movable plate is placed on the back surface of the cover member. When the contact surface is at a temperature exceeding the rating when pressed through a grease member, the contact surface is melted by the heat of the contact surface, and the contact surface is prevented from closing again even if the ambient temperature decreases. It is configured to be fixed to the back surface of the cover member.

Further, in the embodiment of the present invention, the thermoplastic resin member is configured to be adhered to, for example, the cover member. Further, for example, the first thermoplastic resin member is attached to the first thermoplastic resin member. A second thermoplastic resin member having a low thermal deformation temperature, and a surface of the first thermoplastic resin member is disposed on the switch portion side, and a surface of the second thermoplastic resin member is disposed on the switch portion side. It is configured to be disposed on the force bar member side.

In this case, for example, the thermoplastic resin member has the surface of the second thermoplastic resin member adhered to the edge of the opening of the main body housing, and the cover member has the opening of the main body housing from above the thermoplastic resin member. It is arranged so as to cover the part. Further, the safety device according to the embodiment of the present invention is provided with a switch portion for opening and closing an electric circuit by a movable contact being in contact with or separated from a fixed contact point by a bimetal that reverses a warping direction in response to an ambient temperature rising or falling a set temperature. A safety device comprising: a movable plate provided with the movable contact; an end portion formed on a side opposite to the movable contact; and a back surface of a cover member that covers the switch when the contact of the switch portion is opened. A contact surface for pressing the back surface of the cover member, and an insulating thermoplastic resin member disposed on the contact surface, wherein the thermoplastic resin member is a warp of the bimetal. When the contact of the switch portion is opened by reversing the direction and the contact surface of the distal end of the movable plate is pressed against the back surface of the cover member via the thermoplastic member, the temperature of the contact surface exceeds the rating. In it was melted at the abutting surface heat when configured the abutment surface so as not to close again contacts also decreases the ambient temperature so as to fix the rear surface of the cover member.

Further, in the safety device according to the embodiment of the present invention, the ambient temperature rises and falls below the set temperature. A safety device having a switch for opening and closing an electric circuit by moving and contacting a fixed contact with a movable contact by a bimetal that reverses a warp direction in response to a change in direction, and a tip of a movable plate having the movable contact. A contact surface formed on the opposite side of the movable contact to press the back surface of the cover member so as to contact the back surface of the cover member covering the switch when the contact of the switch portion is opened; An insulating thermoplastic resin member disposed on a portion of the back surface of the contact surface which is pressed to make contact with the contact surface, and wherein the thermoplastic resin member is connected to the switch by reversing the warping direction of the bimetal. Applicable when the contact surface of the movable plate has a temperature exceeding the rating when the contact surface of the movable plate is pressed against the back surface of the cover member through the thermoplastic member. Face to face In to melt, and the abutment surface so as not to close again contacts also decreases the ambient temperature so as to fix the rear surface of the cover member. In addition, the safety device according to the embodiment of the present invention includes a switch portion that opens and closes an electric circuit by moving and contacting a movable contact with a fixed contact point by using a pi-metal that reverses a warping direction in response to an ambient temperature rising or falling a set temperature. A safety device comprising: a synthetic resin protrusion that forms a fulcrum for reversing the warping direction of the bimetal at a substantially central position of the bimetal, wherein the protrusion is provided when the contact is opened by the reversal of the pi metal. When the temperature of the pi metal exceeds the rating, the pi metal is melted by the heat of the bimetal and adheres to the bimetal, and the bimetal is maintained in an inverted shape so that the contact does not close again even when the ambient temperature decreases. You.

Further, the safety device according to the embodiment of the present invention is provided with a switch portion for opening and closing an electric circuit by a movable contact being in contact with or separated from a fixed contact point by a bimetal that reverses a warping direction in response to an ambient temperature rising or falling a set temperature. A safety device comprising a movable plate made of a shape memory alloy and having the movable contact at a tip end thereof, wherein the shape memory alloy forming the movable plate is operated at an operating temperature equal to or lower than the bimetal rating. The bimetal is rated when the contact is opened due to the reversal of the bimetal When the set temperature exceeds 7, it is deformed by the heat of the bimetal, and the contact is kept open regardless of the return inversion operation of the bimetal due to the decrease in the ambient temperature.

Further, the safety device according to the embodiment of the present invention is provided with a switch portion for opening and closing an electric circuit by a movable contact being in contact with or separated from a fixed contact point by a bimetal that reverses a warping direction in response to an ambient temperature rising or falling a set temperature. A safety device provided with a thermoplastic foam resin disposed near the fixed contact and facing a tip of a movable plate having the movable contact, wherein the thermoplastic foam resin is a reversal of the bimetal. Therefore, when the bimetal is at a temperature exceeding the rating when the contact is opened, the bimetal is melted and foamed by the heat of the bimetal, and regardless of the return reversal operation of the bimetal due to a decrease in the ambient temperature, the tip of the movable plate. It is configured to suppress the deformation of and maintain the open state of the contact point.

As described above, according to the present invention, a wide contact surface is formed at the end of the movable plate having the movable contact, and a thermoplastic member is provided between this surface and the cover member. In this case, the switching operation of the contacts corresponding to the rise and fall of the ambient temperature can be repeated, and the function can be stopped by keeping the contacts open in the event of a special abnormality. However, it is possible to easily avoid the danger of continuously reusing the main unit, which may have a malfunction due to the special abnormal state.

Also, since only a thermoplastic resin member is interposed, various abnormal conditions can be avoided by changing the thermoplastic resin members with different heat distortion temperatures without changing the configuration of each part of the safety device. It is possible to easily provide safety devices corresponding to the degree. BRIEF DESCRIPTION OF THE FIGURES FIGS. 1A and 1B are side sectional views of the safety device according to the first embodiment, wherein FIG. 1A is a diagram illustrating a state during a closing operation, and FIG. 1B is a diagram illustrating a state during an opening operation.

FIGS. 2A and 2B are side sectional views of the safety device according to the second embodiment, in which FIG. 2A is a diagram illustrating a state during a closing operation, and FIG. 2B is a diagram illustrating a state during an opening operation.

FIGS. 3A and 3B are side sectional views of the safety device according to the third embodiment. FIG. 3A is a diagram illustrating a state during a closing operation, and FIG. 3B is a diagram illustrating a state during an opening operation.

4A and 4B are side sectional views of a safety device according to a fourth embodiment, in which FIG. 4A is a diagram illustrating a state at the time of a closing operation, and FIG. 4B is a diagram illustrating a state at the time of an opening operation.

FIGS. 5A and 5B are side sectional views of a safety device according to a fifth embodiment, in which FIG. 5A is a diagram illustrating a state during a closing operation, and FIG. 5B is a diagram illustrating a state during an opening operation.

FIGS. 6A and 6B are side sectional views of a safety device according to a sixth embodiment, in which FIG. 6A is a diagram illustrating a state during a closing operation, and FIG. 6B is a diagram illustrating a state during an opening operation.

FIG. 7 is a diagram illustrating an example of a method of bonding a two-layered thermoplastic film to a main body housing.

FIGS. 8A and 8B are side sectional views each showing an example of a conventional safety device. 9 (a) is a side sectional view showing another example of the conventional safety device, and FIG. 9 (b) is an enlarged sectional view taken along the line AA 'of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 (a) and 1 (b) are side sectional views of the safety device according to the first embodiment. FIG. 1 (a) shows a state during a closing operation, and FIG. 1 (b) shows a state during an opening operation. The state of is shown. As shown in Figs. (A) and (b), the safety device 15 is composed of a shallow rectangular main body housing 16 in the longitudinal direction (left-right direction in the figure). And 17b, and inside the main body housing 16 is connected to the external terminal 17a. A fixed contact 18 connected via the inside of the housing wall and a movable contact 20 connected to the inside of the housing wall via the movable plate 19 are also provided at the external terminal 17b.

One end of the movable plate 19 connected to the external terminal 17 b is fixed to the body housing 16 by the support portion 21, and the other end where the movable contact 20 is provided is connected to the movable contact 20. On the opposite side, a contact surface 22 formed by cutting and bending is provided. A bimetal 23 having one end inserted between the contact surface 22 and the step portion of the movable plate 19 having a step formed by the above-described cut and bending is inserted in the longitudinal direction of the main body housing 16. It is arranged to extend.

At normal temperature, the bimetal 23 is warped downward and protrudes upward as shown in FIG. 3A, and the protruding portion is formed substantially at the center of the cover member 24. The end of the movable plate 19 on which the movable contact 20 is disposed is pressed down by contact with the movable contact 20. As a result, the movable contact 20 is pressed against the fixed contact 18 and the contact is closed.

The cover member 24 is made of a metal or a hard resin, and a thermoplastic resin member is disposed between the back surface of the cover member 24 and the contact surface 22. In this example, the thermoplastic resin member 25 is a thermoplastic resin film, and when the cover member 24 is made of metal, it is formed of an insulating resin film. Affixed.

The thermoplastic resin member 25 may be bonded with an appropriate adhesive (or an adhesive), or a temperature at which the thermoplastic resin member 25 itself exhibits an adhesive action due to viscosity (hereinafter referred to as thermal deformation). (Referred to as a temperature). Instead of adhering a film, the resin may be melted with high heat and applied to the back surface of the cover member 24, or may be sprayed.

When the ambient temperature rises above a predetermined temperature in a normal rated use condition, the safety device 15 reverses the bimetal 23 as shown in FIG. 10 Warps up and becomes convex downward. At this time, the bimetal in the convex state

At approximately the center of the lower surface of 23, a fulcrum portion 26 formed integrally with the body housing 16 and projecting upward through the cutout hole 191-1 of the movable plate 19 abuts. You. As a result, the bimetal 23 is supported so as to be pushed upward, and the movable contact 20 is provided by the end inserted between the contact surface 22 of the movable plate 19 and the step portion. The movable contact 19 is pushed up by the end of the movable plate 19, whereby the movable contact 20 is opened on the one hand, and the contact surface 22 is pressed against the back surface of the force member 24 via the thermoplastic resin member 25 on the other hand. Is done.

In the operating condition at normal rating as described above, the operating temperature of the safety device 15 is usually set to 100 ° C or less, so the temperature of the contact section (movable contact 20, fixed contact 18) rises. Does not become very large. Therefore, at the ambient temperature at the time of normal rating where the bimetal 23 reverses as shown in FIG. 3B, the temperature transmitted from the contact surface 22 to the thermoplastic resin member 25 is the same as that of the thermoplastic resin member 25. It is below the deformation temperature. Therefore, there is no change in the state of the thermoplastic resin member 25, and when the ambient temperature decreases, the bimetal 23 returns to the inverted state again, and returns to the closed state as shown in FIG.

However, if an overcurrent flows through the contacts or a special abnormal condition occurs, such as when the ambient temperature far exceeds the rated temperature, the contacts will open due to the reversal of the bimetal 23 and the overheating of the contacts due to the overcurrent until then, Due to overheating of the surroundings exceeding the temperature or the high-temperature arc that interrupts the overcurrent between the contacts at the time of opening, the end of the movable plate 19 where the movable contact point 20 is disposed, that is, the contact surface 22 is overheated. That is, the temperature becomes equal to or higher than the thermal deformation temperature of the thermoplastic resin member 25, and the contact surface 22 is pressed against the back surface of the cover member 24 via the thermoplastic resin member 25 as shown in FIG. When heated, the thermoplastic resin member 25, which has been in a molten state due to heat above the thermal deformation temperature of the contact surface 22 in the overheated state, adheres to the contact surface 22 and solidifies due to a decrease in temperature. Contact surface 2 2 to back surface Make. 11 Since the contact surface 22 is formed widely, the above adhesive force is extremely strong, and at least a part of the contact surface 22 may be provided with irregularities to secure the adhesive force. Even if the later bimetal 23 attempts to return to the inverted state due to a decrease in ambient temperature, the contact surface 22 is firmly adhered to the back surface of the cover member 24, and the contact does not close. As described above, the contact is kept open and the periodic opening / closing operation of the contact due to a change in the ambient temperature is stopped. Thus, for example, after the main unit such as a secondary battery has passed a special abnormal accident, etc., It is prevented from being used again.

FIGS. 2 (a) and 2 (b) are side sectional views of a safety device according to the second embodiment. FIG. 2 (a) shows a state during a closing operation, and FIG. 2 (b) shows an opening operation. The state at the time is shown. In FIGS. 2 (a) and 2 (b), the same components as those shown in FIGS. 1 (a) and 1 (b) are the same as those in FIGS. 1 (a) and 1 (b). ), The same numbers are given, and different parts are given new numbers.

As shown in FIGS. 2A and 2B, between the back surface of the cover member 24 and the contact surface 22 (in this example, not only between the contact surface 22 but also the entire surface). A thermoplastic resin member 29 having a two-layer structure including a first thermoplastic resin member 27 and a second thermoplastic resin member 28 is disposed. The first and second thermoplastic resin members are both thermoplastic films, and are obtained by laminating a thermoplastic resin member (film) 28 on one surface of the first thermoplastic resin member (film) 27. It is.

The surface of the first thermoplastic resin member 27 is opposed to the contact surface 22, and its thermal deformation temperature is the same as that of the thermoplastic resin member 25 shown in FIGS. 1 (a) and 1 (b). As in the case described above, the contact surface 22 is adjusted so as to be easily softened at an abnormal temperature and exhibit adhesiveness. The other surface of the second thermoplastic resin member 28 faces the back surface of the cover member 24, and its heat deformation temperature is set lower than the heat deformation temperature of the first thermoplastic resin member 27. ing.

As a material of the first thermoplastic resin member 27, polyether 12 Films such as polyethylene film, polychlorinated vinyl film, polyolefin, nylon, polypropylene, and fluorine resin can be used. Further, as the material of the second thermoplastic resin member 28, in addition to the material generally called hot melt, the same material as the material of the first thermoplastic resin member 27 described above may be used. It is also possible to use one that is set to be as follows.

In the configuration of the present example, it is not necessary to attach the thermoplastic resin member 29 having the above-described two-layer structure to the back surface of the cover member 24 in advance. It may be just arranged so that it comes between them. In this case, the end surface of the second thermoplastic resin member 28 only needs to be bonded to the upper surface of the edge of the opening of the main body housing 16. Then, the cover member 24 is disposed over the thermoplastic resin member 29 so as to cover the opening of the main housing 16.

As a method of bonding the second thermoplastic resin member 28 to the body housing 16 edge, an appropriate adhesive may be used, or thermocompression bonding may be performed. When the housing 16 is made of an appropriate resin, the housing 16 can be bonded using a laser beam. In any case, the thermoplastic resin member 29 does not necessarily have to be adhered to the back surface of the cover member 24 at the portion facing the contact surface 22.

In the configuration of this example shown in Figs. 2 (a) and 2 (b), the opening and closing operation of the movable contact 20 with respect to the fixed contact 18 by the bimetal 23 and the heat by the contact surface 22 in the normal rated operation. The pressing operation on the back surface of the cover member 24 via the plastic resin member 29 is the same as in the case of FIGS. L (a) and (b).

In this example, if an abnormal condition occurs, such as an overcurrent flowing through the contacts or the ambient temperature exceeding the rated temperature, the contact surface 22 becomes overheated as in the case of Fig. 1 (b). Then, it is pressed against the back surface of the cover member 24 via the thermoplastic resin member 29 having a two-layer structure. As a result, the thermoplastic resin member 27 exceeds the heat deformation temperature and fuses to the contact surface 22, and the slightly lowered heat is conducted from the contact surface 22. The thermoplastic 1 "green resin member 28 also easily softens or melts due to the low heat deformation temperature and is adhered to the back surface of the cover member 24.

Thus, the contact surface 22 is fixed to the back surface of the cover member 24 via the thermoplastic resin members 27 and 28. Even if the bimetal 23 attempts to return to the inverted state due to a decrease in the ambient temperature, the contact does not close due to the adhesion of the contact surface 22 to the back surface of the cover member 24, and the contact is kept open.

3 (a) and 3 (b) are side sectional views of a safety device according to the third embodiment. FIG. 3 (a) shows a state during a closing operation, and FIG. 3 (b) shows a state during an opening operation. The state of is shown. In FIGS. 3 (a) and 3 (b), the same components as those shown in FIGS. 1 (a) and 1 (b) are the same as those shown in FIGS. ), The same numbers are given, and different parts are given new numbers.

As shown in FIGS. 3 (a) and 3 (b), a thermoplastic resin member 30 is provided between the back surface of the cover member 24 and the contact surface 22 by sticking to the contact surface 22. Can be In this case, the bonding of the thermoplastic resin member 30 to the contact surface 22 can be easily formed by any method such as printing, coating, or spraying.

In the configuration of this example shown in FIGS. 3 (a) and 3 (b), the opening / closing operation of the movable contact 20 with respect to the fixed contact 18 by the bimetal conductor 23 and the heat by the contact surface 22 in the normal rated operation are also performed. The pressing operation on the back surface of the cover member 24 via the plastic resin member 30 is the same as in the case of FIGS. L (a) and (b).

In this example, if an abnormal condition occurs, such as an overcurrent flowing through the contacts or the ambient temperature exceeding the rated temperature, the contact surface 22 becomes overheated as in the case of Fig. 1 (b). Presses the thermoplastic resin member 30 against the back surface of the cover member 24. Thereby, the thermoplastic resin member 30 is fused to the back surface of the cover member 24, and the contact surface 22 is fixed to the back surface of the cover member 24. In this case as well, even if the pie metal 23 tries to return to the reverse position due to a drop in the ambient temperature, the contact surface 22 returns to the back of the cover member 24. The contact does not close due to the bonding of 14, and the contact is kept open.

FIGS. 4 (a) and 4 (b) are side sectional views of a safety device according to the fourth embodiment. FIG. 4 (a) shows a state during a closing operation, and FIG. 4 (b) shows a state during an opening operation. The state of is shown. In FIGS. 4 (a) and 4 (b), the same components as those shown in FIGS. 1 (a) and 1 (b) are the same as those shown in FIGS. 1 (a) and 1 (b). ), The same numbers are given, and different parts are given new numbers.

As shown in FIGS. 4 (a) and 4 (b), a thermoplastic resin member 31 is provided between the back surface of the cover member 24 and the contact surface 22. It is provided by sticking to a portion facing the above. In this case, the bonding of the thermoplastic resin member 31 to the back surface of the cover member 24 can be easily formed by any method such as printing, coating, and spraying. In this example, the point that the thermoplastic resin member 31 is adhered to the back surface of the cover member 24 is shown in FIG. 3 (a), where the thermoplastic resin member 30 is attached to the contact surface 22. The only difference from the case of b) is that the operation at normal rating and the operation at the time of special abnormality are the same as those in Figs. 3 (a) and 3 (b).

FIGS. 5 (a) and 5 (b) are side sectional views of a safety device according to the fifth embodiment. FIG. 5 (a) shows a state during a closing operation, and FIG. 5 (b) shows a state during an opening operation. The state of is shown. In FIGS. 5 (a) and 5 (b), the same components as those of the safety device shown in FIGS. 1 (a) and 1 (b) include only those necessary for explanation. ), The same numbers are given, and different parts are given new numbers.

In this example, as shown in FIG. 5 (a), no thermoplastic resin member is arranged between the back surface of the cover member 24 and the contact surface 22. In the present example, a fulcrum 26 protruding upward and supporting the inverted bimetal 23 integrally formed with the main body housing 16 is formed of a thermoplastic resin.

In this case, the fulcrum portion 26 may not be formed integrally with the main body housing 16 but may be formed in the same portion and separately from the main body housing 16. Also molding The materials can be selected from a wide variety of materials, such as nylon, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, and liquid crystal polymer.

In this example, the operation at the normal rating is the same as that of the safety device shown in FIGS. 1 to 4, but the bimetal 23 reverses and the movable contact 20 turns as shown in FIG. At the same time, the fulcrum part 26 pressed against the inverted convex lower part of the bimetal 23 together with the movable metal contact 20 and the movable plate 19 caused by the heat of the overheated bimetal 23 The metal is melted, fused to the lower surface of the bimetal 23, and solidified to fix the inverted shape of the bimetal 23.

As a result, even if the temperature decreases, the return inversion operation of the bimetal 23 is prohibited, the contact is kept open, and reuse of the main unit that has passed the special abnormal use environment is prevented.

Although not specifically shown, the movable plate 19 itself is made of a shape memory alloy such as a Ti-Ni system or a Cu-Zn-A1 system which deforms at a predetermined temperature, and the predetermined temperature is set to a bi-metal. If the temperature is higher than the reversal temperature of 23, the switching operation is repeated at the normal rating as in the case of Figs. 1 to 5, and in the special abnormal state, the movable plate 19 and the bimetal 23 are overheated. The shape memory alloy constituting the movable plate 19 can keep the open state. In this case as well, even if the temperature drops, the reversal reversal operation of the bimetal 23 is prohibited, the contacts are kept open, and reuse of the main unit after passing through a special abnormal use environment is prevented.

6 (a) and 6 (b) are side sectional views of a safety device according to the sixth embodiment, wherein FIG. 6 (a) shows a state during a closing operation, and FIG. 6 (b) shows a state during an opening operation. The state of is shown. In FIGS. 6 (a) and 6 (b), the same components as those shown in FIGS. 1 (a) and 1 (b) are the same as those shown in FIGS. 1 (a) and 1 (b). ), The same numbers are given, and different parts are given new numbers. 16 Also in this example, as shown in FIG. 6 (a), no thermoplastic resin member is arranged between the back surface of the cover member 24 and the contact surface 22. Further, in this example, the fulcrum 26 integrally formed with the main body housing 16 is not a thermoplastic resin. Instead, in the present example, a thermoplastic foamed resin 32 is disposed near the fixed contact 18 and near the tip of the movable plate 19 provided with the movable contact 20. The thermoplastic foaming resin 32 can be formed by adding a foaming agent to the thermoplastic resin or dispersing fine bubbles.

In this configuration, the operation at normal rating is the same as that of the safety device shown in FIGS. Then, at the time of special abnormality, when the bimetal 23 reverses and the movable contact 201 opens as shown in FIG. 6 (b), the thermoplastic foam resin 32 melts and foams due to the ambient temperature in the overheated state. The foamed raised portion 32-1 suppresses deformation of the end of the movable plate tip 19 irrespective of the return inversion operation of the bimetal 23 due to a decrease in the ambient temperature. As a result, even in this case, after the special abnormal condition occurs, the contact is kept open.

FIG. 7 is a view showing an example of a method of bonding the thermoplastic film 29 having a two-layer structure shown in FIGS. 2A and 2B to the main body housing 16. In this example, a first thermoplastic resin film 28 having a relatively high melting point is adhered to a main body housing 16 which is a molded product made of a high melting point material. Since the second thermoplastic resin film 28 having a melting point is bonded, it is difficult to perform bonding by thermocompression bonding.

Therefore, if both layers of the film are optically transmissive, the two layers of the film are transmitted with laser light 33 having a wavelength of 0.2 to 1.2 μm, and the adhesive surface at the edge of the main body housing 16 is removed. By melting, the two-layer film can be bonded to the main housing 16 side.

As described above in detail, according to the present invention, the movable plate end having the movable contact 17 A wide abutment surface is formed, and only a thermoplastic member is provided between this surface and the cover member. During operation, the function can be stopped by keeping the contacts open.

As a result, using a safety device with a simple configuration, it is easy to avoid the danger of continuing to reuse the main unit that may have malfunctioned due to a special abnormal condition. Is obtained.

Further, since only a thermoplastic resin member is interposed, it is possible to use various thermoplastic resin members having different heat distortion temperatures without changing the configuration of each part of the safety device.

As a result, it is possible to easily provide safety devices corresponding to various degrees of abnormal conditions, which greatly contributes to the operation of safety devices in a wide range of fields. Industrial applicability

As described above, the safety device of the present invention can be used, for example, as a safety device such as a secondary battery, and of course, requires a certain level of safety by ensuring that the open state of the contact that has occurred at the time of abnormality is permanently maintained. It can be used in all industries that use equipment.

Claims

18 Claims

1. A safety device including a switch for opening and closing an electric circuit by a movable contact being in contact with and separated from a fixed contact by a bimetal that reverses a warping direction in response to an ambient temperature rising or falling a set temperature,

The back surface of the cover member is formed on the end of the movable plate having the movable contact opposite to the movable contact, and the back surface of the cover member is brought into contact with the back surface of the cover member covering the switch when the contact of the switch portion is opened. A contact surface to be pressed;

An insulating thermoplastic resin member disposed between the contact surface and the back surface of the cover member,

With

In the thermoplastic resin member, the contact point of the switch portion is opened by reversing the warping direction of the bimetal, and the abutting surface of the front end of the movable plate is connected to the back surface of the cover member via the thermoplastic resin member. When the contact surface is at a temperature exceeding the rating when pressed and pressed, the contact surface is melted by the heat of the contact surface, and the contact surface is covered with the cover member so that the contact does not close again even if the ambient temperature decreases. A safety device, wherein the safety device is fixed to a back surface of the vehicle.

2. The safety device according to claim 1, wherein the thermoplastic resin member is adhered to the cover member.

3. The thermoplastic resin member comprises a first thermoplastic resin member and a second thermoplastic resin member having a low thermal deformation temperature bonded to the first thermoplastic resin member. 2. The safety device according to claim 1, wherein a surface of the thermoplastic resin member is disposed on the switch portion side, and a surface of the second thermoplastic resin member is disposed on the cover member side.

4. The thermoplastic resin member has a main body housing that faces the second thermoplastic resin member. 4. The safety device according to claim 3, wherein the cover member is bonded to an edge of an opening of the housing, and the cover member is disposed over the thermoplastic resin member so as to cover the opening of the main body housing.

5. A safety device equipped with a switch that opens and closes an electric circuit by moving and contacting a fixed contact with a bimetal that reverses the direction of warping as the ambient temperature rises or falls below a set temperature.

A back surface of a force bar member formed on a tip of a movable plate having the movable contact on a side opposite to the movable contact, and abutting against a back surface of a cover member covering the switch when the contact of the switch portion is opened. An abutting surface for pressing

An insulating thermoplastic resin member disposed on the corresponding contact surface,

With

In the thermoplastic resin member, the contact point of the switch portion is opened by reversing the warping direction of the bimetal, and the abutting surface of the tip portion of the movable plate is provided on the back surface of the cover member via the thermoplastic member. When the contact surface is at a temperature exceeding the rating when pressed, the contact surface is melted by the heat of the corresponding contact surface, and the contact surface is covered with the cover member so that the contact does not close again even if the ambient temperature decreases. Stick to the back,

A safety device characterized by that:

6. A safety device provided with a switch for opening and closing an electric circuit by moving and contacting a fixed contact with a bimetal that reverses a warping direction in response to an ambient temperature rising and falling a set temperature,

A back surface of a cover member formed at a tip of a movable plate having the movable contact opposite to the movable contact, and abutting against a back surface of a force bar member covering the switch when the contact of the switch is opened. An abutting surface for pressing

An insulating thermoplastic resin member disposed on a portion of the back surface of the cover member that presses the contact surface so as to abut, With 20,

A safety device characterized by that:

7. A safety device provided with a switch for opening and closing an electric circuit by moving a movable contact to and from a fixed contact by a bimetal that reverses a warping direction in response to an ambient temperature rising or falling a set temperature,

A projection of a synthetic resin forming a fulcrum for reversing the direction of the warping of the bimetal at a substantially central position of the bimetal;

When the bimetal is at a temperature exceeding the rating when the contact is opened due to the inversion of the bimetal, the protrusion melts due to the heat of the bimetal and adheres to the bimetal. Maintaining the bimetal in an inverted shape so that it does not close,

A safety device characterized by that:

8. A safety device provided with a switch for opening and closing an electric circuit by moving a movable contact to and away from a fixed contact by a bimetal in which a warping direction is reversed according to an ambient temperature rising and falling a set temperature,

A movable plate made of a shape memory alloy and having the movable contact at a tip end thereof, wherein the shape memory alloy forming the movable plate does not operate at an operating temperature equal to or lower than the rating of the bimetal, and the contact of the bimetal is reversed by inversion. When the bimetal is at a set temperature exceeding the rating when it is opened, the bimetal is deformed by the heat of the bimetal, and regardless of the return reversal operation of the bimetal due to a decrease in ambient temperature, 21 Keep the contacts open.

A safety device characterized by that:

9. A safety device comprising a switch for opening and closing an electric circuit by moving and contacting a fixed contact with a bimetal that reverses a warping direction in response to an ambient temperature increasing or decreasing a set temperature,

A thermoplastic foam resin disposed near the fixed contact and facing a tip of a movable plate having the movable contact;

The thermoplastic foamed resin melts and foams due to the heat of the bimetal when the temperature of the bimetal exceeds a rating when the contact is opened due to the inversion of the bimetal, and the bimetal due to a decrease in the ambient temperature. A safety device wherein the deformation of the tip of the movable plate is suppressed irrespective of the return inversion operation and the contact is kept open.