JP6220130B2 - breaker - Google Patents

Description

  The present invention relates to a small breaker incorporated in a secondary battery pack.

  Conventionally, a breaker is used as a protection device for secondary batteries and motors of various electric devices. The breaker cuts off the current in order to protect the secondary battery when the temperature of the secondary battery during charging / discharging rises excessively or when an overcurrent flows through the electrical equipment. A breaker used as such a protective device is required to operate accurately following temperature changes (having good temperature characteristics).

  Furthermore, in addition to the safety and temperature characteristics described above, when the breaker is used as a protection device for a secondary battery equipped in a thin-type multifunctional portable device called a notebook computer, tablet-type terminal, or smartphone. Therefore, miniaturization and high capacity are required. Recent information terminals are required to be lighter and smaller. The size of the secondary battery mounted thereon is also reduced, and the breaker is required to be downsized as well.

  In a product in which a plurality of parts such as a breaker are assembled, there is a problem that the mechanical strength generally decreases with downsizing. In particular, the terminal exposed to the outside continuously from the fixed piece, the movable piece, etc. is easily subjected to external force, and there is a concern that the adhesion strength between these members and the resin constituting the case is insufficient.

  Patent Document 1 discloses means for increasing the adhesion strength and sealing performance of such a breaker, and the content thereof is a base plate (fixed electrode 20) that is insert-molded in an embedded shape and penetrates the inside of the side wall of the case (main body 10). ), A streak-like protrusion 22 is formed in advance along the width direction in a continuous portion with the base terminal (terminal portion 21). Although such streak-like projections improve the mechanical strength of the case and the terminal, there is a limit to miniaturization.

JP 2003-297204 A

  An object of the present invention is to provide a means for preventing the mechanical strength and the sealing performance from being lowered and further reducing the size of the breaker that accommodates therein the thermally responsive element that is reversed by the snap action to operate the movable piece.

  In order to solve the above-described problems, the present invention provides a fixed piece having a fixed contact, a movable piece having a movable contact that contacts or separates from the fixed contact, a thermoresponsive element that is reversed by a snap action when the temperature rises and operates the movable piece And a breaker comprising a resin case for housing the fixed piece, the movable piece, and the thermally responsive element, wherein the fixed piece and a part of the movable piece are embedded in the resin of the case. The surface embedded in the groove is provided with a groove-shaped stamp, and the back surface of the stamp is flat.

  The breaker according to the present invention is further characterized in that the inscription extends linearly along the short direction of the fixed piece or the movable piece.

  The breaker of the present invention is further characterized in that inscriptions are arranged on both the front and back surfaces of the fixed piece or the movable piece.

  The breaker of the present invention is further characterized in that a through hole is provided in the vicinity of the inscription.

  According to the present invention, in the breaker in which the fixed piece and a part of the movable piece are embedded in the resin of the case, the surface embedded in the resin in the fixed piece or the movable piece is provided with a groove-shaped stamp, and the stamp is further provided. Since the back surface of the case is flat, the mechanical strength of the case and the terminal is increased by the anchor effect, and further miniaturization can be realized.

  According to the breaker of the present invention, since the inscription extends linearly along the short direction of the fixed piece or the movable piece, the sealing performance of the case can be improved.

  According to the breaker of the present invention, the seal is arranged on both the front and back surfaces of the fixed piece or the movable piece, so that the sealing performance of the case can be further improved.

  According to the breaker of the present invention, since the through hole is provided in the vicinity of the marking, the mechanical strength of the case can be further improved.

Cross-sectional view and assembly diagram of breaker of the present invention Sectional view in which the movable piece of the breaker and a part of the case are enlarged The perspective view which expanded the movable piece of the breaker, and a part of case Sectional view of the breaker of the present invention in a normal state Sectional drawing at the time of operation | movement of the breaker of this invention

  A breaker according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of the breaker. The breaker 1 includes a base plate 2 (fixed piece) having a fixed contact 21, an arm 3 (movable piece) having a movable contact 31 at the tip, a disk 4 (thermally responsive element) that deforms with a change in temperature, and a PTC 6. (Positive characteristic thermistor), a base plate 2, an arm 3, a disk 4, and a resin case 5 that accommodates the PTC 6. The case 5 includes a base 51 and a cover 52 attached to the upper surface of the base 51.

  The base plate 2 is formed by pressing a metal plate mainly composed of copper (metal plate such as phosphor bronze, copper-titanium alloy, white or brass), and is incorporated in the base 51 by insert molding. A base terminal 22 is formed at one end of the base plate 2, and a PTC 6 is placed at the center. The fixed contact 21 is formed by clad, plated, or coated with a conductive material such as silver, silver-nickel alloy, copper-silver alloy, gold-silver alloy, etc., and is a storage space formed above the base 51. Exposed to 5s. The base terminal 22 protrudes from one end of the base 51 to the outside.

  The arm 3 is formed in an arm shape by pressing a metal plate equivalent to the base plate 2. An arm terminal 32 is formed at one end in the longitudinal direction of the arm 3 and protrudes outside the case 5, and a movable contact 31 is formed at the other end. The movable contact 31 is formed of the same material as the fixed contact 21 and is joined to the tip of the arm 3 by a technique such as welding or caulking. The arm 3 includes a movable portion 33 and a fixed portion 34 between the movable contact 31 and the arm terminal 32. The movable portion 33 is an arm-shaped movable portion and corresponds to the tip of the arm 3. When the movable portion 33 is elastically deformed during normal operation, the movable contact 31 formed at the tip is pressed toward the fixed contact 21. Then, the base plate 2 and the arm 3 can be energized. The fixed portion 34 corresponds to the base end of the movable portion 33, and is sandwiched between the base 51 and the cover 52 to fix the arm 3.

  The disk 4 has an arcuate shape and is made of a composite material such as bimetal or trimetal. When the operating temperature is reached by overheating, the curved shape of the disk 4 is reversed by a snap action, and is restored when the temperature falls below the return temperature by cooling. The shape of the disk 4 can be formed by pressing. The material and shape of the disk 4 are not particularly limited as long as the movable part 33 of the arm 3 is pushed up by the reversing operation of the disk 4 at the desired temperature and returns to its original state by the elastic force of the movable part 33. In view of the efficiency and the efficiency of the reversing operation, a rectangle is desirable, and a rectangle close to a square is desirable in order to efficiently push up the movable portion 33 while being small. Examples of the material of the disk 4 include various materials such as white, brass, stainless steel, such as copper-nickel-manganese alloy or nickel-chromium-iron alloy on the high expansion side and iron-nickel alloy on the low expansion side. A material obtained by laminating two types of materials having different thermal expansion coefficients made of the above alloys is used in combination according to the required conditions.

  The base 51 and the cover 52 constituting the case 5 are molded from a resin such as flame retardant polyamide, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), or polybutylene terephthalate (PBT) having excellent heat resistance. The base 51 is formed with a storage space 5s for storing the arm 3, the disk 4, the PTC 6, and the like. A part of the embedded base plate 2 is exposed to the outside on the inner bottom surface of the base 51 and contacts the electrode on the surface of the PTC 6. Thus, the base plate 2 can be electrically connected to the arm 3 and generates a leakage current during operation.

  A cover 52 is mounted on the upper surface of the base 51 so as to close the storage space 5s of the base 51 that stores the arm 3, the disk 4, the PTC 6, and the like. The base 51 and the cover 52 are joined by, for example, ultrasonic welding. The cover 52 has a cover plate 53, which is embedded in the resin by insert molding, like the base plate 2. The cover plate 53 is provided with a carrier portion 53a and is used as a holding means for transportation during manufacture such as insert molding and assembly of the cover 5. The carrier portion 53 a is a part of the cover plate 53, and the cover plate 53 forms the inner upper surface 5 t of the case 5. The cover plate 53 is provided from the viewpoint of mechanical strength, but it can also be exposed to the outside.

  The PTC 6 is a circular or rectangular flat plate-shaped heating resistor element whose main component is a metal oxide such as barium titanate. In addition, a conductive polymer or the like is used as the material of the PTC 6. As long as the PTC 6 is a positive temperature coefficient thermistor that increases the resistance value as the temperature rises and limits the current, the type of operating current, operating voltage, operating temperature, return temperature, etc. can be selected according to need, and the shape of these As long as the various properties are not impaired, there is no particular limitation.

  The PTC 6 is placed on the base plate 2 that is partially exposed at the bottom surface of the base 51. The disk 4 is placed on the PTC 6, and the movable part 33 is further disposed on the disk 4. When the movable portion 33 is pushed up by the reversing operation of the disk 4 and the power supply between the base plate 2 and the arm 3 is cut off, a leakage current is generated in the PTC 6 via the disk 4. During operation, the PTC 6 generates heat due to the leakage current, and this heat continues to maintain the inverted state of the disk 4 (FIG. 5). When the overcharge or abnormal state is eliminated, the PTC 6 is no longer heated, and the disk 4 returns to the return temperature and is restored to its original shape. Then, the movable contact 31 and the fixed contact 21 come into contact again due to the elastic force of the movable portion 33 of the arm 3, the circuit is released from the interrupted state, and returns to the conductive state shown in FIG.

  The base plate 2, the arm 3, and the cover plate 53 have portions that are embedded in the resin of the case 5 and penetrate the resin of the case 5 so as to communicate the outside and the inside of the breaker 1. The base plate 2 has a structure in which the fixed contact 21 is exposed to the internal space and the base terminal 22 is exposed to the external space. In the arm 3, the movable part 33 and the arm terminal 32 are in the same state. In the cover plate 53, the inner upper surface 5t of the case 5 and the carrier portion 53a are the same. The base plate 2 has a structure in which the bottom surface of the base 51 on which the PTC 6 is disposed similarly penetrates the resin of the case 5. At the bottom surface 5 b of the base 51, the base plate 2 is exposed on both the inner bottom surface and the outer bottom surface of the breaker 1.

  An embedded portion 2i exists between the fixed contact 21 and the base terminal 22 of the base plate 2, and is embedded in the resin on the side wall 5w of the base 51 by insert molding in advance. The base 51 accommodates the PTC 6, and around the PTC 6, a part of the base plate 2 serves as an embedded portion 2 j and is embedded in the resin of the base 51. The embedded portion 2j is embedded in resin on the inner bottom surface of the breaker 1, and the back side is exposed to the outside on the outer bottom surface. The embedded portion 3 i of the arm 3 is embedded in another side wall 5 v of the case 5 by ultrasonic welding when the cover 52 is assembled to the base 51. The embedded portion 53i of the cover plate 53 is embedded in the cover 51 in advance by insert molding in the same manner as the embedded portion 2i.

  In these buried portions, the surface of each member is represented by a stamp 7 (hereinafter, the one given to the arm 3 is represented as a stamp 7. The stamp is any of the buried portion 2i, the buried portion 2j, the buried portion 3i, and the buried portion 53i. And may have a recess. Resin has entered the recesses of these stamps 7 by insert molding or ultrasonic welding. The resin that has entered in this manner is cured to produce an anchor effect (throwing effect) and improve the mechanical strength (particularly the tensile strength) of the breaker 1. The concave portion of the stamp 7 is formed to extend in the width direction of the arm 3 and is a linear slot. Further, the surface of the arm 3 is flat on the back surface of the stamp 7. This facilitates downsizing (particularly low profile) in designing and manufacturing the breaker 1.

  FIG. 2 is an enlarged cross-sectional view of the embedded portion 3 i showing various cross-sectional shapes of the stamp 7. In the embedded portion 3i, unlike the concave portion formed by a normal half-punching process, the plate thickness in the vicinity of the concave portion of the stamp 7 is not substantially changed as a whole, and the plate thickness is reduced only at the stamp 7 by stamping. In addition to a rectangle (square shape) as shown in FIG. 2A, the shape of the stamp 7 when viewed in cross section is a U shape (round shape) such as U in FIG. 2, and a V shape such as V in FIG. There are variations such as shape (triangle). Further, as shown in FIG. 2, V-shaped marks may be arranged adjacent to each other to form a W shape. The stamp 7 may be singular as shown in FIG. 2A or plural as shown in FIG. 2B. Examples of methods for producing these shapes include press working such as cutting, half blanking, leveling (flattening) and coining, forging, and the like. The grooves of the stamp 7 may be provided with irregularities such as knurling.

  Further, as shown in FIG. 2C, on both surfaces of the embedded portion 2i or the embedded portion 3i, it is possible to mark the surfaces 7 of these members respectively. When the inscription 7 is applied to both surfaces, it can be arranged at the same position in the horizontal direction, but it is preferable to displace it in a sectional view as shown in the drawing from the viewpoint of ease of processing. The form in which the inscription 7 is applied to both sides has a higher tensile strength than the case where only one side is provided. Further, it may be applied to both the front and back surfaces of the embedded portion 3i as shown in FIG. 2D, and the embodiment shown in FIG.

  In the engraving 7, the grooves of the recesses are arranged linearly so as to run in the width direction (short direction) of the arm 3 as a whole. The sealing property of the case 5 is improved. In order to form the marking 7 in a linear shape, one has a form of continuously marking one or a plurality of parallel slots as shown in FIG. Alternatively, as shown in the perspective view and the cross-sectional view of FIG. 3 in which the embedded portion 3i is enlarged, a large number of spotted concave portions are arranged in the vicinity of each other and are formed intermittently on one line, thereby being substantially linear. It is also possible to make this slot, and this form has the same effect as the above. Even if the shape of the spot-like recess as shown in FIG. 3A is a circular shape in a plan view and a semispherical shape in a cross-sectional view, it is a triangular shape in a plan view and a cross-sectional view as shown in FIG. It may be pyramidal. The spot-like concave shape includes various kinds of variations such as a concave wound shape such as C in FIG. 3, a wedge shape such as D in FIG. 3, and a horseshoe shape such as E in FIG.

  Furthermore, a through hole (not shown) can be added to the embedded portion 2i, the embedded portion 3i, or the embedded portion 53i by cutting, punching, or the like. By providing a through-hole in the vicinity of the stamp 7, the adhesion between the resins increases between the base 51 and the cover 52, and the insert metal fittings such as the base plate 2 and the cover plate 53 are more firmly sandwiched between the resins, and the sealing property Becomes larger.

  The place where the marking 7 and the through hole are arranged is preferably in the vicinity of a portion where the metal material is exposed to the outside, such as the terminal and the bottom surface 5 b of the case 5. In particular, small places where the distance and thickness between the space inside the case 5 and the outside are short need to be tightly sealed, so depending on the area embedded in the resin, not only one place but also multiple places It is also possible to provide the groove 7 with a planar shape as a whole.

  In the form of a concave portion having a protrusion shape on the back surface as in the prior art, there is a limit to the space for forming the concave portion, and thus there is a limit to reducing the height of the resin portion, particularly the resin portion. However, as in this embodiment, a concave shape is given to only one side of the metal plate, so that the complicated shape of the other part of the breaker, for example, a bent part, a thin part of the metal material, a part where the resin becomes thin Regardless of, etc., machining with a high degree of freedom is possible. Thus, by providing the inscription and allowing the resin to enter, even in the case of a breaker having a small size and a low profile, the mechanical strength and sealing performance of the terminal and the case can be improved by the anchor effect.

  The various inscriptions described above can be applied to other types of breakers. For example, the PTC6 is abolished, both the arm terminal and the base terminal are insert-molded in advance and embedded in the case, and the movable part of the arm is assembled by welding and connected, the cover brace is extended instead of the arm terminal The same applies to a cover terminal with a movable part of an arm connected to a cover plate by welding, an arm and a disk that are integrally formed (a movable piece is formed of a laminated metal plate of two or more layers), etc. Is done.

1 breaker,
2 Base plate (fixed piece),
21 fixed contact,
22 Base terminal,
3 arm (movable piece),
31 movable contact,
32 arm terminals,
33 moving parts,
34 fixing part,
4 disc (thermally responsive element),
5 cases,
51 base,
52 cover,
53 Cover plate,
6 PTC (PTC thermistor),
7 Stamp,

Claims (3)

A fixed piece having a fixed contact,
A movable piece having a movable contact that contacts or separates from the fixed contact;
A heat-responsive element that reverses by a snap action when the temperature rises and operates the movable piece;
And a resin case that houses the fixed piece, the movable piece, and the thermally responsive element,
A part of the movable piece is embedded in the resin of the case,
The surface embedded in the resin in the movable piece is imprinted with a slot, and the back surface of the engraving is flat,
The case includes a base and a cover attached to the upper surface of the base,
When the cover is assembled to the base, the movable piece is sandwiched between the base and the cover and embedded in the case by ultrasonic welding,
The stamp extends continuously linearly along the short direction of the fixed piece or the movable piece, and the ultrasonic welding causes a resin to enter and harden into the recess of the stamp, thereby sealing the case. A method for manufacturing a breaker. Oite to claim 1, wherein the marking method of manufacturing a breaker, characterized in that disposed on both sides of the fixing piece or the movable piece. According to claim 1 or 2, the manufacturing method of the circuit breaker, characterized in that the through hole in the vicinity of the marking is provided.

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