JP2014154518A - Breaker and safety circuit including the same and secondary battery circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent temperature characteristics by preventing deformation of a fixing piece during current interruption, in a breaker used as a protective device of secondary battery, and the like.SOLUTION: A fixing piece 2 has a terminal 22 connected electrically with an external circuit, and a support 23 for supporting a PTC thermistor 6. Ramps 29a, 29b inclining inward of a resin base 71 and being embedded therein are formed on the outer surface of the support 23. A force F from the PTC thermistor 6 received by the fixing piece 2 during current interruption is transmitted to the resin base 71 via the ramps 29a, 29b, and a stress applied to the fixing piece 2 is dispersed to the resin base 71 from the outer surface of the support 23. Consequently, deformation of the fixing piece 2 can be suppressed, and excellent temperature characteristics can be maintained while suppressing the contact resistance of a fixed contact 21 and a movable contact 3.

Description

  The present invention relates to a small breaker built in a secondary battery pack or the like of an electric device.

  Conventionally, a breaker is used as a protection device (safety circuit) for secondary batteries and motors of various electric devices. When the temperature of the secondary battery during charging / discharging rises excessively, or when an abnormality occurs such as when an overcurrent flows through a motor or the like equipped in a device such as an automobile or home appliance, Cut off current to protect secondary batteries and motors. Breakers used as such protective devices operate accurately following temperature changes (having good temperature characteristics) and have stable resistance when energized to ensure the safety of the equipment. It is required to be.

  In addition, when the breaker is used as a protection device for a secondary battery or the like installed in an electric device such as a thin-type multifunctional mobile phone called a notebook personal computer, a tablet-type portable information terminal device, or a smartphone, the above-described case is used. In addition to ensuring safety, miniaturization is required. In particular, in recent portable information terminal devices, users have a strong desire for miniaturization (thinning), and devices newly released by each company are designed to be small in order to ensure superiority in design. The tendency to be remarkable is remarkable. Against this background, breakers that are mounted together with secondary batteries as one component of portable information terminal devices are also strongly required to be further miniaturized.

  The breaker is provided with a thermally responsive element that operates according to a temperature change and conducts or cuts off a current. Patent Document 1 discloses a breaker to which a bimetal is applied as a thermally responsive element. Bimetal is an element that is formed by laminating two types of plate-like metal materials having different coefficients of thermal expansion, and controls the conduction state of the contact by changing the shape in accordance with a temperature change. The breaker shown in the same document is a case in which parts such as a fixed piece (base terminal), a movable piece (movable arm), a thermally responsive element, and a PTC thermistor are housed in a case. Used by connecting to the electrical circuit of electrical equipment. In the breaker disclosed in Patent Document 1, the fixed piece is incorporated into the case body (resin base) by insert molding (see paragraph (0031) and the like of the same document).

WO2011 / 105175 gazette

  FIG. 17 shows a state in which the thermally responsive element 5 is reversely warped and cuts off the current in the breaker 200 equivalent to the breaker disclosed in Patent Document 1. In this state, the vicinity of both ends of the thermally responsive element 5 deformed in reverse warp contacts the projection 44 of the movable piece 4, pushes up the movable contact 3 at the tip of the movable piece 4, and separates the movable contact 3 from the fixed contact 21. Let At this time, the thermally responsive element 5 is pushed down from the protrusions 44a and 44b of the movable piece 4 by reaction. Since the thermally responsive element 5 is in contact with the PTC thermistor 6 at an intermediate portion between both ends in contact with the protrusions 44a and 44b, the force due to the above-described reaction is caused by the fixing piece 2 via the PTC thermistor 6. Is transmitted to. The support portion 23 formed on the other end of the fixed piece 2 is formed with protrusions 24a and 24b that come into contact with the PTC thermistor 6, and the fixed piece 2 has a PTC thermistor at the apex of the protrusions 24a and 24b. 6 receives a force F downward and deforms. Since the fixed piece 2 and the resin base 71 are bonded by insert molding, if the bonding force is sufficiently large, the stress due to the force F is dispersed in the resin base 71 and the like, and deformation of the fixed piece 2 is suppressed. .

  By the way, in order to reduce the contact resistance between the fixed contact 21 and the movable contact 3 during energization, it is effective to set the elastic force generated by the elastic portion 43 high and increase the contact pressure between the fixed contact 21 and the movable contact 3. It is. However, depending on the elastic force generated by the elastic portion 43 of the movable piece 4, the force F received by the projections 24 a and 24 b of the fixed piece 2 from the PTC thermistor 6 also increases, and the fixed piece 2 and the resin base 71 are formed by insert molding. Only the coupling force cannot suppress the deformation of the fixed piece 2, and as shown in FIG. 17, the distal end portion 23 a of the fixed piece 2 may eventually be separated from the resin base 71. Once the tip of the fixed piece 2 is separated from the resin base 71, the fixed piece 2 must be countered by the elastic force generated by the elastic portion 43 of the movable piece 4 only by the elastic force generated by the fixed piece 2. The support 23 is greatly deformed. In particular, in a breaker in which protrusions 81a and 81b that contact the movable piece 4 are formed on the cover piece 8 and protrusions 44a and 44b that contact the thermally responsive element 5 are formed on the movable piece 4, respectively, this tendency becomes remarkable. Then, the deformation of the support portion 23 of the fixed piece 2 affects the posture of the PTC thermistor 6 and the thermal actuator 5 and thus the position and posture of the movable contact 3, and the temperature characteristics of the breaker 200 deteriorate (particularly from the non-conductive state). There is a risk that the return temperature to the conductive state varies).

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a breaker that can maintain good temperature characteristics while suppressing contact resistance between a fixed contact and a movable contact. .

  In order to achieve the above object, a breaker of the present invention includes a fixed piece having a fixed contact, a movable contact, a movable piece that presses the movable contact against the fixed contact, and a temperature change. A thermally responsive element that operates the movable piece so that the movable contact is separated from the fixed contact by being deformed, and is interposed between the thermally responsive element and the fixed piece, and from the fixed contact to the movable contact A positive temperature coefficient thermistor that conducts the movable piece and the fixed piece through the thermal responsive element when they are separated from each other, and a case that houses the fixed piece, the movable piece, the thermal responsive element, and the positive temperature coefficient thermistor The fixed piece includes a terminal electrically connected to the outside and a support portion that supports the positive temperature coefficient thermistor, and an outer surface of the support portion includes an inner portion of the case. Towards It is inclined I, in which the inclined portion which is embedded in the casing is formed.

  In this invention, it is preferable that the fixed piece has a curved portion bent toward the inside of the case at the proximal end of the inclined portion.

  In this invention, the support part is formed with a plurality of protrusions that protrude toward the positive characteristic thermistor and abut against the positive characteristic thermistor, and the inclined part is at least one of the plurality of protrusions. It is preferably formed at a location adjacent to the protrusion.

  In the present invention, at least one of the plurality of protrusions is formed in a region overlapping with a contact region between the thermal responsive element and the positive temperature coefficient thermistor in plan view when the thermally responsive element is deformed. It is preferable.

  In this invention, it is preferable that the inclined portion is formed so as to protrude from a distal end portion of the support portion.

  In this invention, it is preferable that the inclined portion is formed to protrude from a side end portion of the support portion.

  In this invention, it is preferable that the fixed piece has a side end portion formed along an edge of the positive temperature coefficient thermistor.

  In this invention, it is preferable that the case has a concave portion that is recessed from a peripheral portion, and the side end portion is formed so as to be retracted from the concave portion of the case.

  In addition, a safety circuit for an electric device according to the present invention includes the breaker.

  In addition, a secondary battery pack according to the present invention includes the breaker.

  According to the breaker of the present invention, since the inclined portion inclined toward the inside of the case is formed on the outer surface of the support portion of the fixed piece, and the inclined portion is embedded in the case, the fixed piece is a positive temperature coefficient thermistor. The force received from is transmitted to the case through the inclined portion. As a result, the stress applied to the fixed piece is distributed from the outer surface of the support part to the case, so that deformation of the fixed piece at the time of current interruption can be suppressed, and the contact resistance between the fixed contact and the movable contact can be suppressed, and a good temperature can be achieved. It becomes possible to maintain the characteristics.

  Further, according to the configuration in which the fixed piece has the curved portion bent toward the inside of the case at the base end of the inclined portion, the inclined portion can be easily and inexpensively formed with a simple structure.

  Further, the support portion is formed with a plurality of protrusions that protrude toward the positive temperature coefficient thermistor and abut against the positive temperature coefficient thermistor, and the inclined portion is formed at a location adjacent to at least one of the protrusions. For example, the force applied to the protrusion from the positive temperature coefficient thermistor during deformation of the thermally responsive element can be efficiently transmitted to the case via the inclined portion, and deformation of the support portion can be further suppressed.

  In addition, according to the configuration in which at least one of the protrusions is formed in a place overlapping with the contact area between the thermal response element and the positive temperature coefficient thermistor in plan view when the thermal response element is deformed, The posture of the positive temperature coefficient thermistor is stabilized during deformation. Thereby, the temperature characteristic of a breaker can be maintained further better.

  In addition, according to the configuration in which the inclined portion is formed so as to protrude from the distal end portion of the support portion, deformation of the distal end portion of the support portion can be suppressed.

  Further, according to the configuration in which the inclined portion is formed so as to protrude from the side end portion of the support portion, deformation of the side end portion of the support portion can be suppressed.

  In addition, according to the configuration in which the fixed piece has the end portion formed along the edge of the positive temperature coefficient thermistor, the support portion is deformed as the contact area between the support portion and the case decreases. Can be effectively suppressed by the inclined portion.

  In addition, according to the configuration in which the case has a recessed portion that is recessed from the peripheral portion and the side end portion is formed by retracting from the recessed portion of the case, poor filling of the resin material associated with providing the recessed portion in the case Can be suppressed. Therefore, the degree of freedom such as the position and size of the recess can be increased. The concave portion is formed around the gate mark or the convex marking so that the gate mark or the convex marking generated when the case is molded does not protrude from the bottom surface of the case.

  Moreover, according to the safety circuit or the secondary battery pack provided with the breaker of the present invention, the safety circuit or the secondary battery pack in which safety is ensured by excellent temperature characteristics can be manufactured.

The assembly perspective view which shows the structure of the breaker by one Embodiment of this invention. Sectional drawing which shows operation | movement of the breaker in a normal charge or discharge state. Sectional drawing which shows operation | movement of a breaker in the time of an overcharge state or abnormality. Another sectional view of a breaker in the usual charge or discharge state. The bottom view of the case and fixed piece which comprise the breaker. The perspective view which looked at the breaker from the back side. Sectional drawing of the same breaker which expands and shows the vicinity of the front-end | tip part of a fixed piece. The perspective view which fractures | ruptures and shows a part of resin base and fixing piece applied to the breaker. The perspective view which shows the structure of the fixed piece. The top view which shows the modification of a fixed piece. Sectional drawing which shows another modification of a resin base and a fixing piece. The bottom view which shows the variation of the modification of the resin base and a fixed piece. The bottom view which shows another variation of the modification of the resin base and a fixed piece. The bottom view which shows another variation of the modification of the resin base and a fixed piece. The top view which shows the structure of the secondary battery pack provided with the breaker of this invention. The circuit diagram of the safety circuit provided with the breaker of this invention. Sectional drawing which shows the operation | movement in the time of an overcharge state or abnormality of the conventional breaker.

  A breaker according to an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show the configuration of the breaker. The breaker 1 includes a fixed piece 2 having a fixed contact 21, a movable piece 4 having a movable contact 3 at the tip, a thermally responsive element 5 that deforms with a change in temperature, a PTC (Positive Temperature Coefficient) thermistor 6, , A fixed piece 2, a movable piece 4, a thermally responsive element 5, and a case 7 for housing a PTC thermistor 6. The case 7 includes a resin base (first case) 71, a cover member (second case) 72 attached to the upper surface of the resin base 71, a cover piece 8, and the like.

  The fixing piece 2 is formed by pressing a metal plate mainly composed of phosphor bronze or the like (other metal plate such as copper-titanium alloy, white or brass) and embedded in the resin base 71 by insert molding. It is. A terminal 22 electrically connected to an external circuit is formed at one end of the fixed piece 2, and a support portion 23 that supports the PTC thermistor 6 is formed at the other end side. The PTC thermistor 6 is placed on the convex protrusions (the dowels) 24a and 24b formed at three places on the support portion 23 of the fixed piece 2, and is supported by the protrusions 24a and 24b. The fixed contact 21 is formed at a position facing the movable contact 3 by cladding, plating, coating, or the like of a conductive material such as silver, nickel, nickel-silver alloy, copper-silver alloy, gold-silver alloy. , The resin base 71 is exposed from a part of the opening 73b formed above. The terminal 22 protrudes outward from one end of the resin base 71. The fixed piece 2 is exposed from the resin base 71 at the terminal 22, the fixed contact 21, and the support portion 23, and is embedded in the resin base 71 between the terminal 22 and the fixed contact 21 and between the fixed contact 21 and the support portion 23. The

  The movable piece 4 is formed in an arm shape symmetrical to the center line in the longitudinal direction by pressing a plate-like metal material. As a material of the movable piece 4, a material mainly composed of phosphor bronze or the like equivalent to the fixed piece 2 is preferable. In addition, a conductive elastic material such as copper-titanium alloy, white or brass may be used. A terminal 41 electrically connected to an external circuit is formed at one end in the longitudinal direction of the movable piece 4 and is exposed to the outside from the resin base 71. A movable contact 3 is formed at the other end of the movable piece 4 (corresponding to the tip of the arm-shaped movable piece 4). The movable contact 3 is formed of the same material as that of the fixed contact 21 and is joined to the tip of the movable piece 4 by a technique such as clad or crimping in addition to welding. In the present application, in the movable piece 4, the surface to which the movable contact 3 is joined (that is, the lower surface in FIG. 1) is the back surface, and the opposite surface is the front surface. It is described as a surface. The movable piece 4 has a contact portion 42 (corresponding to a base end of the arm-like movable piece 4 and a portion embedded in the case 7) and an elastic portion 43 between the movable contact 3 and the terminal 41. . The contact portion 42 has a protrusion 42 a that contacts the resin base 71 and the cover member 72 between the terminal 41 and the elastic portion 43 and protrudes in a wing shape in the short direction of the movable piece 4. The elastic part 43 extends from the contact part 42 to the movable contact 3 side. The movable piece 4 is fixed by being sandwiched by the resin base 71 and the cover member 72 at the abutting portion 42 from the front and back sides, and the elastic portion 43 is elastically deformed, whereby the movable contact 3 formed at the tip thereof is a fixed contact. The fixed piece 2 and the movable piece 4 can be energized by being pressed and brought into contact with the side 21.

  The resin base 71 and the cover member 72 are respectively formed with an abutting portion 74 and an abutting portion 79 that abut against the abutting portion 42 of the movable piece 4 and hold the abutting portion 42 in a fixed state. In the present embodiment, a contact portion 74 is formed in a region extending from the outer edge of the housing portion 73 of the resin base 71 to the outer wall of the resin base 71. The contact portion 74 constitutes a part of the bottom wall (inner bottom surface) of the case 7 in FIG. In the cover member 72, a contact portion 79 is formed in a region facing the contact portion 74 with the movable piece 4 interposed therebetween. The contact portion 79 constitutes a part of the top wall (inner top surface) of the case 7 in FIG. The contact portion 42 contacts the contact portion 74 of the resin base 71 on the back surface, and contacts the contact portion 79 of the cover member 72 on the front surface. The movable piece 4 is sandwiched from the front and back surfaces of the contact portion 42 by the contact portion 74 and the contact portion 79 and fixed to the case 7. In this embodiment, since the contact part 42 has the protrusion part 42a which protrudes in the shape of a wing in the transversal direction of the movable piece 4, the contact part 74 and the contact part of the case 7 have a wide and large area. The movable piece 4 is firmly fixed to the case 7 by being sandwiched by 79.

  The movable piece 4 is curved or bent at the elastic portion 43 by pressing. The degree of bending or bending is not particularly limited as long as the thermally responsive element 5 can be accommodated, and may be appropriately set in consideration of the elastic force at the operating temperature and the return temperature, the pressing force of the contact point, and the like. In addition, a pair of protrusions (contact portions) 44 a and 44 b are formed on the lower surface of the elastic portion 43 so as to face the heat-responsive element 5. The protrusions 44a and 44b and the thermally responsive element 5 come into contact with each other, and the deformation of the thermally responsive element 5 is transmitted to the elastic portion 43 via the protrusions 44a and 44b (see FIGS. 1, 2 and 3).

  Further, the movable piece 4 has a through hole 45 that penetrates in the thickness direction of the movable piece 4 and through which the protrusion 74a of the resin base 71 is inserted, a step bent portion 46 formed in a crank shape, and a step bent portion 46. Part of the movable piece 4 is cut off in the short direction perpendicular to the longitudinal direction of the movable piece 4 and the formed slope 47, the pair of engaging portions 48 engaged with the positioning portion 75 of the resin base 71. A constricted portion 49 is formed. The through hole 45, the step bent part 46, the slope 47, the engaging part 48, and the constricted part 49 are provided on the opposite side of the movable contact 3 with the elastic part 43 interposed therebetween, that is, on the terminal 41 side with respect to the elastic part 43. ing. The through hole 45 is provided on the center line in the longitudinal direction of the movable piece 4 at the constricted portion 49. The slope 47 is formed continuously along the short direction of the movable piece 4. The engaging portions 48 are provided at two locations along the short direction of the movable piece 4.

  The through hole 45 is formed in the contact portion 42 of the movable piece 4. The contact portion 42 is formed wider than the elastic portion 43 in the short direction of the movable piece 4. Thereby, the cross-sectional area perpendicular to the longitudinal direction of the movable piece 4 in the contact portion 42 becomes a portion larger than the cross-sectional area in the elastic portion 43. Further, the through hole 45 is formed in an oval shape that is long in the lateral direction of the movable piece 4 in plan view (as viewed in the thickness direction of the movable piece 4).

  The engaging portion 48 is formed at the end edge of the constricted portion 49 on the terminal 41 side. The constricted portion 49 is disposed between the contact portion 42 and the terminal 41 on the side opposite to the elastic portion 43 with the contact portion 42 interposed therebetween. The width dimension of the constricted portion 49 (the length dimension in the short direction of the movable piece 4, the same applies hereinafter) is preferably set equal to or less than the width dimension of the elastic portion 43, but at least the contact portion 42. And it should just be set smaller than the width dimension of the terminal 41. The constricted part 49 in this embodiment has a function as the second elastic part in the above-mentioned Patent Document 1, and absorbs an external force and an impact applied to the terminal 41 and appropriately maintains the position of the movable contact 3. .

  The thermally responsive element 5 has an initial shape curved in an arc shape and is made of a composite material such as bimetal or trimetal. When the operating temperature is reached due to overheating, the curved shape is reversely warped with snap motion, and is restored when the temperature falls below the return temperature due to cooling. The initial shape of the thermoresponsive element 5 can be formed by pressing. As long as the elastic portion 43 of the movable piece 4 is pushed up by the reverse warping operation of the thermal response element 5 at a desired temperature and returns to the original state by the elastic force of the elastic portion 43, the material and shape of the thermal response element 5 are particularly limited. Although not intended, a rectangular shape is desirable from the viewpoint of productivity and efficiency of reverse warping operation, and it is desirable that the rectangular shape is close to a square in order to efficiently push up the elastic portion 43 while being small. Examples of the material of the thermally responsive element 5 include, for example, 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 laminate of two types of materials having different coefficients of thermal expansion made of various alloys such as steel is used in combination according to the required conditions.

  When the energization of the fixed piece 2 and the movable piece 4 is interrupted by the reverse warping operation of the thermal response element 5, the current flowing through the PTC thermistor 6 increases. As long as the PTC thermistor 6 is a positive temperature coefficient thermistor that limits the current by increasing the resistance value as the temperature rises, the type of operation current, operation voltage, operation temperature, return temperature, etc. can be selected as necessary. The material and shape are not particularly limited as long as these properties are not impaired. In the present embodiment, a ceramic sintered body containing barium titanate, strontium titanate or calcium titanate is used. In addition to the ceramic sintered body, a so-called polymer PTC in which conductive particles such as carbon are contained in a polymer may be used.

  The resin base 71 and the cover member 72 constituting the case 7 are molded from a resin such as flame retardant polyamide, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polybutylene terephthalate (PBT) having excellent heat resistance. Yes. A material other than the resin may be applied as long as characteristics equal to or higher than those of the above-described resin can be obtained. The resin base 71 is formed with a housing portion 73 for housing the thermally responsive element 5, the PTC thermistor 6, and the like, and openings 73 a and 73 b for housing the movable piece 4. Note that the edges of the movable piece 4, the thermally responsive element 5, and the PTC thermistor 6 incorporated in the resin base 71 are in contact with each other by a frame formed inside the storage portion 73. It will be guided at the time.

  The resin base 71 has a projection 74a inserted into the through hole 45 of the movable piece 4, a pair of positioning portions 75 for positioning the movable piece 4, and a terminal 41 for exposing the movable piece 4 to the outside. A window 76 is provided. The protrusion 74 a is formed in a shape corresponding to the through hole 45 and reinforces the resin base 71. The height of the projection 74a, that is, the projection amount is set to be larger than the thickness of the movable piece 4, and a concave portion corresponding to the top of the projection 74a is provided on the back surface of the cover member 72 as necessary. The positioning portion 75 is provided in a shape corresponding to the constricted portion 49 of the movable piece 4. That is, the positioning portion 75 is interposed in a portion cut out in the vicinity of the constricted portion 49, reinforces the resin base 71, and is welded to the contact portion 79 of the cover member 72 to increase the rigidity and strength of the case 7. .

  A cover piece 8 is embedded in the cover member 72 by insert molding. The cover piece 8 is formed by pressing a metal plate mainly composed of the above-described phosphor bronze or the like or a metal plate such as stainless steel. As shown in FIGS. 2 and 3, the cover piece 8 abuts on the upper surface of the movable piece 4 as appropriate, restricts the movement of the movable piece 4, and the rigidity and strength of the case 7 as a casing as a result of the cover member 72. Contributes to the downsizing of the breaker 1

  As shown in FIG. 1, the cover member 72 is disposed on the upper surface of the resin base 71 so as to close the opening 73 a of the resin base 71 that houses the fixed piece 2, the movable piece 4, the thermally responsive element 5, the PTC thermistor 6, and the like. It is attached to. The resin base 71 and the cover member 72 are joined by, for example, ultrasonic welding.

  FIG. 2 shows the operation of the breaker 1 in a normal charge or discharge state. In a normal charging or discharging state, the thermal responsive element 5 maintains the initial shape (before reverse warping), the fixed contact 21 and the movable contact 3 come into contact with each other, and the breaker 1 passes through the elastic portion 43 of the movable piece 4. The terminals 22 and 41 are electrically connected. The elastic part 43 of the movable piece 4 and the thermal responsive element 5 are in contact, and the movable piece 4, the thermal responsive element 5, the PTC thermistor 6 and the fixed piece 2 are electrically connected as a circuit. However, since the resistance of the PTC thermistor 6 is overwhelmingly larger than the resistance of the movable piece 4, the current flowing through the PTC thermistor 6 is substantially larger than the amount flowing through the fixed contact 21 and the movable contact 3. It can be ignored.

  FIG. 3 shows the operation of the breaker 1 in an overcharged state or an abnormality. When the PTC thermistor 6 is overheated due to overcharging or abnormality, the thermal actuator 5 that has reached the operating temperature is warped in reverse, and the elastic portion 43 of the movable piece 4 is pushed up so that the fixed contact 21 and the movable contact 3 Are separated from each other. At this time, the current flowing between the fixed contact 21 and the movable contact 3 is interrupted, and a slight leakage current flows through the thermal actuator 5 and the PTC thermistor 6. Since the PTC thermistor 6 continues to generate heat as long as such a leakage current flows, the resistance value is drastically increased while maintaining the thermally actuated element 5 in the reverse warped state, so that the current is a path between the fixed contact 21 and the movable contact 3. There is only the above-described slight leakage current (which constitutes a self-holding circuit). This leakage current can be used for other functions of the safety device.

  When the overcharge state is canceled or the abnormal state is resolved, the heat generation of the PTC thermistor 6 is also stopped, and the thermal actuator 5 returns to the return temperature and is restored to the original initial shape. Then, the movable contact 3 and the fixed contact 21 come into contact again by the elastic force of the elastic portion 43 of the movable piece 4, the circuit is released from the interruption state, and returns to the conduction state shown in FIG.

  FIG. 4 shows another cross section of the breaker 1 in a normal charge or discharge state. A recess 91 (see FIG. 5 described later) is formed on the bottom surface of the resin base 71 of the case 7 of the breaker 1, and FIG. 4 is a cross section including the recess 91.

  FIG. 5 shows the resin base 71 of the case 7 constituting the breaker 1 and the bottom surface of the fixed piece 2. The support portion 23 of the fixed piece 2 is exposed on the bottom surface of the resin base 71. In the vicinity of the corner portion of the outer bottom surface of the resin base 71, concave portions 91 and 93 that are recessed from the peripheral portion are formed.

  The recess 91 accommodates the gate mark 92. The gate trace 92 is a trace of the resin material that is cured in the gate of the mold and is released at the time of release or thereafter, and protrudes slightly from the bottom surface of the recess 91. The depth of the recess 91 is set so that the tip of the gate mark 92 does not protrude from the bottom surface of the resin base 71. The radius of the recess 91 is set according to the diameter of the gate.

  The concave portion 92 is formed around the convex marking 94. In FIG. 5, as an example, an inscription 94 of the character string “A” is formed so as to protrude from the bottom surface of the recess 93. For example, the product number or production lot number of the breaker 1 can be indicated by the character string represented by the stamp 94. Similar to the gate mark 92, the depth of the recess 92 and the protruding amount of the marking 94 are set so that the tip of the marking 94 does not protrude from the bottom surface of the resin base 71. Further, the shape and size of the recess 93 are set according to the marking 94. Here, a character string is illustrated as the form of the stamp 94, but the same effect can be obtained even if the recess 92 or the stamp 94 is formed by a symbol, a figure, or the like.

  Considering the ease of processing, normally, the fixed piece 2 is formed in a rectangular shape in the support portion 23. This rectangular shape is indicated by a broken line as a virtual edge 23z of the fixed piece 2 in FIG. In addition, the rectangle including the virtual edge 23z of the fixed piece 2 can be estimated from the shape, size, function, etc. that the fixed piece 2 should have in consideration of other members such as the PTC thermistor 6. The breaker 1 of the present embodiment has a retracting portion 25 indicated by broken line hatching in FIG. The breaker 1 according to the present embodiment is provided with a retracting portion 25 that retracts inward from the virtual end edge 23z of the support portion 23, whereby the distance D (the distance D between the end edge of the fixed piece 2 and the recesses 91 and 93 of the resin base 71 is provided. Each shortest distance) is configured to be a predetermined first distance D1 or more. That is, even when the distance D between the virtual edge of the fixed piece 2 and the recesses 91 and 93 of the resin base 71 is less than the first distance D1, the retracting portion 25 is connected to the edge of the fixed piece 2 and the resin. The base 71 is retracted from the recesses 91 and 93 such that the distance D between the recesses 91 and 93 of the base 71 is more than the first distance D1. The first distance D1 is further determined by considering the flow of the resin material forming the resin base 71 in the mold, the mechanical strength of the resin base 71, the withstand voltage of the breaker 1, the temperature characteristics, and the like. Laboratories Inc.) standards and TUV (Technology Inspection Association) standards and other safety standards are set to be equal to or greater than the minimum thickness of the resin portion defined for each resin material used. More specifically, the first distance D1 is set to 0.1 mm to 0.40 mm, for example. In order to reduce the size of the breaker 1, it is desirable to set the first distance D1 to be equal to or less than the upper limit value. Further, in order to suppress the flow failure of the resin material and to ensure the mechanical strength of the resin base 71, the withstand voltage of the breaker 1, etc., it is desirable to set the first distance D1 to be equal to or more than the above lower limit value.

  By providing the retracting portion 25, the distance between the actual edge of the fixed piece 2 and the concave portions 91 and 93 can be made larger than the distance between the virtual edge of the fixed piece 2 and the concave portions 91 and 93. Therefore, if the distance between the actual edge of the fixed piece 2 and the recesses 91 and 93 is secured longer than the first distance D1, the distance between the virtual edge of the fixed piece 2 and the recesses 91 and 93 is It may be shorter than one distance D1. As shown in FIG. 5, when the retracting portion 25 and the recess 91 overlap in plan view (bottom view), the distance between the virtual edge of the fixed piece 2 and the recess 91 is a negative value. Can be compared.

  As shown in FIG. 5, the end edge of the fixed piece 2 retracted by the retracting portion 25 is formed along the end edge of the PTC thermistor 6. In other words, the retracting portion 25 is formed by retracting inward from the virtual end edge so that the end edge of the fixed piece 2 is along the end edge of the PTC thermistor 6 in plan view. In the present embodiment, the end edge of the fixed piece 2 retracted by the retracting portion 25 is formed to be similar to the end edge of the PTC thermistor 6 in plan view. In other words, the end edge of the fixed piece 2 retracted by the retracting portion 25 becomes the end portion 26 formed along the end edge of the PTC thermistor 6. Further, as shown in FIGS. 1 and 5, since the frame 73 d formed on the resin base 71 is formed to face the edge of the PTC thermistor 6, the fixed piece retracted by the retracting portion 25. The end edge 2 (side end portion 26) is formed along the frame 73d and is formed to be similar to the frame 73d in a plan view, and the side end surface of the resin base 71 is outside the frame 73d. Embedded in the resin that constitutes Here, the similar shape means that the outer shapes of the two substantially coincide with each other, and may be formed with curvatures close to each other so that the contours of the two do not differ significantly. Further, the curvature is not necessarily constant in the area retracted by the retracting section 25, and may be partially different.

  In the retracting portion 25, the metal material that forms the fixed piece 2 is removed, and the resin material that forms the resin base 71 is filled when the resin base 71 is insert-molded. The retracting portion 25 is formed by press working. Since the resin material is filled in the portion from which the metal material has been removed, the resin base 71 can be molded at low cost using a mold equivalent to the conventional one. Since the distance D between the edge of the fixed piece 2 and the recesses 91 and 93 of the resin base 71 can be separated by the first distance D1 or more by the retracting portion 25, the cavity space of the mold for molding the resin base 71 is locally localized. Narrowing is suppressed. As a result, it is possible to suppress the filling failure of the resin material between the end edge of the fixed piece 2 and the recesses 91 and 93 and the strength reduction of the case 7.

  By providing the retracting portion 25 at the edge of the fixed piece 2, the degree of freedom of arrangement of the concave portions 91 and 93 while ensuring the distance D between the edge of the fixed piece 2 and the concave portions 91 and 93 is equal to or greater than the first distance D1. The recesses 91 and 93 can be concentrated and arranged near the protrusions 24 a and 24 b of the fixed piece 2, that is, in the vicinity of the PTC thermistor 6. In particular, in the present embodiment, since the end edge of the fixed piece 2 retracted by the retracting portion 25 is formed along the end edge of the PTC thermistor 6, the recesses 91 and 93 are further formed in the PTC thermistor 6. It is possible to collect and arrange in the vicinity of. Thereby, size reduction of the case 7 and the breaker 1 can be achieved.

  Further, since the edge of the fixed piece 2 retracted by the retracting portion 25 is embedded in the resin constituting the resin base 71 outside the frame 73d, the edge of the fixed piece 2 is firmly coupled to the resin base 71. Can be made. In addition, since the edge of the fixed piece 2 retracted by the retracting portion 25 is formed along the frame 73d and is similar to the frame 73d in a plan view, the outside of the frame 73d Thus, the distribution of the region where the fixed piece 2 is embedded in the resin base 71 can be made uniform. Thereby, it can avoid that stress concentrates on the fixed piece 2 and the resin base 71, and the intensity | strength of the breaker 1 can be raised. Since the frame 73d is formed so as to face the side surface of the end edge of the PTC thermistor 6, the position and posture of the PTC thermistor 6 are properly maintained. Thereby, the contact state between the PTC thermistor 6 and the protrusions 24a and 24b of the fixed piece 2 is stabilized, and the above-described self-holding circuit by the PTC thermistor 6 can function effectively.

  Further, by increasing the degree of freedom of arrangement of the concave portions 91 and 93 and arranging the concave portions 91 and 93 in the vicinity of the PTC thermistor 6, a part of the movable piece 4 (particularly the step bent portion of the movable piece 4). 46) and the distances D between the recesses 91 and 93 can be set long. Thereby, the distance D between the movable piece 4 and the concave portions 91 and 93 is ensured to be equal to or larger than the second distance D2 (see FIG. 4), and the resin material is poorly filled or the case between the movable piece 4 and the concave portions 91 and 93. It is easy to reduce the size of the breaker 1 while suppressing a decrease in strength of 7. As with the first distance D1, the second distance D2 is determined by the flow of the resin material forming the resin base 71 in the mold, the strength of the resin base 71, the withstand voltage of the breaker 1, and various safety standards. Determined in consideration.

  By the way, when the retracting portion 25 is provided in the fixed piece 2 and the side end portion 26 is retracted inward from the virtual edge, the contact area between the fixed piece 2 and the resin base 71 is near the tip of the support portion 23. There is a concern that the binding force of both decreases. Therefore, as shown in the prior art in FIG. 17, in the state where the thermoresponsive element 5 is reversely warped and deformed by heat and cuts off the current, the tip 23 a of the fixed piece 2 is separated from the resin base 71. The tendency of the support portion 23 of the fixed piece 2 to be greatly deformed increases.

  Therefore, in the present embodiment, extended portions 27a and 27b (see FIG. 6 and the like) extending from the tip end portion 23a and the side end portion 23b of the support portion 23 where the retracting portion 25 is not provided are formed, and the fixed piece 2 and the resin base 71 are configured to ensure a contact area. In addition, the form of the extension parts 27a and 27b is not specifically limited, For example, you may extend in the comb-tooth shape.

  FIG. 6 is a perspective view of the breaker 1 configured as described above as viewed from the back side. A portion of the fixed piece 2 embedded in the resin base 71 is indicated by a broken line. FIG. 7 is an enlarged view of the vicinity of the distal end of the fixed piece when the thermal actuator 5 is deformed. FIG. 8 is a cutaway view of the resin base 71 into which the fixed piece 2 is inserted. FIG. 9 shows the configuration of the fixed piece 2. The fixed piece 2 includes an extending portion 27a extending from the distal end portion 23a of the support portion 23, an extending portion 27b extending from a pair of side end portions 23b facing each other, and the like.

  The base ends of the extending portions 27 a and 27 b are bent or curved toward the inside of the resin base 71. That is, the fixed piece 2 has curved portions 28a and 28b bent or curved inward at the base ends of the extending portions 27a and 27b. As the curved portions 28 a and 28 b are formed at the base ends of the extending portions 27 a and 27 b, the outer surfaces of the extending portions 27 a and 27 b are inclined toward the inside of the resin base 71. That is, inclined portions 29 a and 29 b that are inclined toward the inside of the resin base 71 and are embedded in the resin base 71 are formed on the outer surface of the support portion 23. Further, the edges 27c and 27d of the extending portion 27b in the longitudinal direction of the breaker 1 project in the longitudinal direction (the direction in which the terminal 22 or the terminal 41 is extended). In the present embodiment, the extending portion 27b and the inclined portion 29b are formed over the entire side end portion 23b of the support portion 23, but a part of the side end portion 23b (for example, in the vicinity of the protrusion 24b). Etc.) may be partially formed.

  As shown in FIGS. 7 and 8, the outer surface of the resin base 71 (the lower surface in the figure) is formed on a substantially same plane as the outer surface of the support portion 23 of the fixed piece 2. Therefore, the resin material constituting the resin base 71 flows into the outer surfaces of the extending portions 27a and 27b having the curved portions 28a and 28b at the base ends, and the engaging portions 96a and 96b are formed. . That is, the inclined portions 29 a and 29 b are locked by the locking portions 96 a and 96 b of the resin base 71. In the present embodiment, since the outer surfaces of the extending portions 27a and 27b are inclined toward the inside of the resin base 71 by the inclined portions 29a and 29b, the resin material applied to the locking portions 96a and 96b Inflow is also good, and the locking action of the distal end portion 23a and the side end portion 23b of the support portion 23 by the locking portions 96a and 96b is sufficiently obtained.

  In the present embodiment, the protrusion 24a of the fixed piece 2 is provided in the vicinity of the distal end portion 23a, and the protrusion 24b is provided in the vicinity of the side end portion 23b. Accordingly, the inclined portion 29a is formed at a location adjacent to the protrusion 24a, and the inclined portion 29b is formed at a location adjacent to the protrusion 24b.

  Further, as shown in FIG. 7, the protrusion 24a located in the vicinity of the distal end portion 23a overlaps with the contact region 50 between the thermal reaction element 5 and the PTC thermistor 6 in a plan view when the thermal reaction element 5 is deformed. It is formed in the area to be. Accordingly, when the PTC thermistor 6 receives a pressing force from the thermal response element 5 when the thermal response element 5 is deformed, the protrusion 24a receives the pressing force without generating a moment for rotating the PTC thermistor 6. Can do. Further, even when a moment is generated due to a slight displacement of the contact region 50 with respect to the protrusion 24a, the value can be reduced. Thereby, the attitude | position of the PTC thermistor 6 is stabilized at the time of the deformation | transformation of the thermally responsive element 5. FIG. In the present embodiment, as described above, in order to secure the distance of the movable contact 3 from the fixed contact 21 when the thermal actuator 5 is deformed, that is, when the current is interrupted, while the circuit breaker 1 is reduced in size, The positional relationship between the thermal reaction element 5 and the PTC thermistor 6 is obtained in order to obtain the effect of stabilizing the posture of the PTC thermistor 6 when the thermal reaction element 5 is deformed. What is necessary is just to comprise so that the area | region 50 may be located in the area | region enclosed by several protrusion 24a and protrusion 24b.

  As described above, according to the breaker 1 of the present embodiment, the inclined portions 29 a and 29 b that are inclined toward the inside of the resin base 71 are formed on the outer surface of the support portion 23 of the fixed piece 2. Since 29b is embedded in the resin base 71, the force F received by the fixed piece 2 from the PTC thermistor 6 is transmitted to the resin base 71 via the inclined portions 29a and 29b. As a result, stress applied to the fixed piece 2 is dispersed from the outer surface of the support portion 23 to the resin base 71, so that deformation of the fixed piece 2 at the time of current interruption can be suppressed, and the contact resistance between the fixed contact 21 and the movable contact 3 can be reduced. While suppressing, it becomes possible to maintain a favorable temperature characteristic.

  Further, since the fixed piece 2 has the bent portions 28a and 28b bent inward of the resin base 71 at the base ends of the extending portions 27a and 27b, that is, the base ends of the inclined portions 29a and 29b, it is simple. With the structure, the inclined portions 29a and 29b can be formed easily and inexpensively.

  Also, the support portion 23 is formed with a plurality of protrusions 24a and 24b that protrude toward the PTC thermistor 6 and abut against the PTC thermistor 6, and the inclined portion 29a is formed at a location adjacent to the protrusion 24a. The force F applied to the protrusion 24a from the PTC thermistor 6 during the deformation of the thermally responsive element 5 is efficiently transmitted to the resin base 71 through the inclined portion 29a, thereby further suppressing the deformation of the tip portion 23a of the support portion 23. it can. Similarly, since the inclined portion 29b is formed at a location adjacent to the protrusion 24b, a force F applied to the protrusion 24b from the PTC thermistor 6 when the thermal actuator 5 is deformed is passed through the resin base via the pair of inclined portions 29b. 71 can be efficiently transmitted, and the deformation of the support portion 23 can be further suppressed. As described above, since the inclined portion 29a or 29b is formed at a location adjacent to at least one of the protrusions 24a or 24b, the force applied to the protrusion from the PTC thermistor 6 during the deformation of the thermally responsive element 5 can be reduced. It can transmit efficiently to case 7 via 29b, and can suppress a deformation | transformation of a support part further.

  Further, since the protrusion 24a is formed in a region overlapping with the contact region 50 between the thermal responsive element 5 and the PTC thermistor 6 when the thermal responsive element 5 is deformed, when the thermal responsive element 5 is deformed. The postures of the PTC thermistor 6 and the thermally responsive element 5 are stabilized. Thereby, the position and posture of the movable contact 3 at the time of deformation of the thermally responsive element 5 are stabilized, and the positional relationship between the fixed contact 21 and the movable contact 3 is stabilized. Therefore, the temperature characteristics of the breaker 1 can be maintained even better.

  Further, since the inclined portion 29a is formed so as to protrude from the distal end portion 23a of the support portion 23, deformation of the distal end portion 23a of the support portion 23 can be suppressed. Further, since the inclined portion 29b is formed so as to protrude from the side end portion 23b of the support portion 23, deformation of the side end portion 23b of the support portion 23 can be suppressed. In particular, in the present embodiment, the fixed piece 2 is embedded in the resin base 71 at the distal end portion 23a, the side end portion 23b, and the base end portion (the back surface side of the fixed contact 21) of the support portion 23, that is, around the support portion 23. Therefore, the deformation of the support portion 23 can be effectively suppressed.

  Further, the fixed piece 2 has a side end portion 26 formed along the end edge of the PTC thermistor 6, and the inclined portions 29 a and 29 b are formed in the end portion 26 of the support portion 23. Since it is formed so as to protrude from the distal end portion 23a and the side end portion 23b, it is possible to effectively suppress deformation of the support portion 23 as the contact area between the support portion 23 and the resin base 71 decreases. it can.

  Further, according to the configuration in which the resin base 71 has the concave portions 91 and 93 that are recessed from the peripheral portion, and the side end portion 26 is formed by being retracted from the concave portions 91 and 93 of the resin base 71, the resin base 71 The filling failure of the resin material due to the provision of the recesses 91 and 93 can be suppressed. Accordingly, the degree of freedom of the positions and sizes of the recesses 91 and 93 can be increased.

(Modification)
FIG. 10 shows a fixed piece 2 </ b> A that is a modification of the fixed piece 2. The fixed piece 2A is different from the fixed piece 2 shown in FIG. 9 and the like in that the retracting portion 25 and the side end portion 26 are eliminated and a substantially rectangular support portion 23 is provided. In the fixed piece 2A, the extending portion 27a, the curved portion 28a, and the inclined portion 29a are formed over the entire distal end portion 23a of the substantially rectangular support portion 23. The extending portion 27b, the curved portion 28b, and the inclined portion 29b are formed over substantially the entire side end portion 23b of the substantially rectangular support portion 23. These may be partially formed in a part of the front end portion 23a or the side end portion 23b. When molding the resin base 71 by inserting the fixing piece 2A, the resin material constituting the resin base 71 flows into the outer surfaces of the inclined portions 29a and 29b, and the locking portions 96a and 96b are formed. Same as 2.

  In the fixed piece 2A, the contact area between the support portion 23 and the resin base 71 is ensured to be equal to or greater than that of the conventional breaker 1, and by the locking portions 96a and 96b formed on the outer surfaces of the inclined portions 29a and 29b. The deformation of the support portion 23 is suppressed. Therefore, although the outer dimensions of the breaker 1 tend to be slightly larger due to the elimination of the retracting portion 25 and the side end portion 26, the fixed contact 21 and the movable contact 3 are further suppressed by further suppressing the deformation of the support portion 23. It is possible to maintain good temperature characteristics while suppressing the contact resistance with the.

(Modification)
FIG. 11 shows a cross section of the periphery of the distal end portion 23a of the fixed piece 2B which is another modification of the fixed piece 2. In the fixed piece 2B, an inclined portion 29a is formed on a part of the outer surface without extending the extending portion 27a from the distal end portion 23a. In the modification shown in FIG. 11A, an inclined portion 29a is formed on the outer surface of the tip of the fixed piece 2B. Moreover, in the modification shown in FIG.11 (b), the through-hole 97 is formed in the front-end | tip part 23a of the fixed piece 2B, and the inclined part 29a is formed in the periphery. The inclined portion 29a can be formed by pressing or the like when the protrusion 24a or the like is formed on the fixed piece 2. In any of the modified examples, the resin material constituting the resin base 71 flows into the outer surface of the inclined portion 29a to form the locking portions 96a and 96b, and the deformation of the support portion 23 is suppressed. In FIG. 11B, the resin material constituting the resin base 71 also flows into the through hole 97 to suppress deformation of the fixed piece 2B. In addition, even if it replaces with the inclination part 29a on a slope and the front-end | tip part 23a of the fixed piece 2B is formed in step shape, the equivalent effect is obtained. In the present modification, the inclined portion 29a formed at the distal end portion 23a has been described, but the same applies to the inclined portion 29b formed at the side end portion 23b.

(Modification)
FIG. 12 shows a variation of the modified example of the retracting portion 25, the recessed portion 91, and the inclined portions 29a and 29b. In the following, an example of retreating with respect to the recessed portion 91 is shown, but the same applies to the case of retracting with respect to the recessed portion 93. The shape of the evacuation part 25 is not particularly limited as long as it is a shape that evacuates (escapes) from the recess 91. As shown in FIG. 12 (a), the corner of the edge of the fixed piece 2 is rounded so that the corner of the fixed piece 2 faces the recess 91, or the edge of the edge of the fixed piece 2 as shown in FIG. 12 (b). It may be a chamfered shape that is dropped so as to face the recess 91. Moreover, as shown in FIG.12 (c), the corner | angular corner of the fixed piece 2 was notched in the similar shape along the outer edge of the recessed part 91, or as shown in FIG.12 (d), the fixed piece 2 The corner may be cut in a rectangular shape so as to face the recess 91. Also, as shown in FIG. 12 (e), the corners cut out in a rectangle are filled with inverted corners, or the corners cut out in a rectangle are rounded as shown in FIG. 12 (f). It may be a shape. Such a chamfered or rounded shape is larger than the degree required for processing with respect to other normal corners such as the corner of the terminal 22 of the fixed piece 2 and the corner of the terminal 41 of the movable piece 4, Or the thing which is remarkably rounded or rounded more than the grade given to the normal corner | corner in which the evacuation part 25 is not formed is included. In FIG. 12, the inclined portions 29a and 29b are formed on the outer surface of the extending portion extending from a part or the whole of the front end portion or the side end portion of the support portion 23 where the retracting portion 25 is not formed. It is embedded in 71.

(Modification)
FIG. 13 shows another variation of the modified example of the retracting portion 25, the recessed portion 91, and the inclined portions 29a and 29b. As shown in FIG. 13A, the recess 91 has a shape reaching one side of the edge of the resin base 71, or a shape reaching two sides of the edge of the resin base 71 as shown in FIG. There may be. Also in FIG. 13, the inclined portions 29 a and 29 b are formed on the outer surface of the extending portion that extends from a part or the whole of the front end portion or the side end portion of the support portion 23 in which the retracting portion 25 is not formed. Embedded in the base 71.

(Modification)
FIG. 14 shows still another variation of the modified example of the retracting portion 25, the recessed portion 91, and the inclined portions 29a and 29b. As shown in FIG. 14 (a), a shape in which one side of the edge of the fixed piece 2 is cut out in a similar shape along the outer edge of the recess 91, or as shown in FIG. A shape in which one side of the edge is cut into a rectangle so as to face the recess 91 may be used. Further, as shown in FIG. 14 (c), a shape in which a corner cut out in a rectangle is filled in a reverse chamfered shape, or a shape in which a corner cut out in a rectangle is rounded as shown in FIG. 14 (d). It may be. As shown in FIG. 14E, the recess 91 may have a shape that reaches one side of the edge of the resin base 71. Furthermore, as shown in FIG. 14 (f), the retracting portion 25 may be formed not inside the outer edge of the fixed piece 2 but inside. Also in FIG. 14, the inclined portions 29 a and 29 b are formed on the outer surface of the extending portion extending from a part or the whole of the front end portion or the side end portion of the support portion 23 in which the retracting portion 25 is not formed. Embedded in the base 71. The inclined portions 29 a and 29 b may be formed on the outer surface of the extending portion extending from a part or the whole of the retracting portion 25 and embedded in the resin base 71.

  As described above, the shape of the retracting portion 25 is not limited to a shape based on a circle or a rectangle as long as it is separated from the recesses 91 and 93 by the first distance D1 or more, for example, a shape based on a polygon. Alternatively, it may be an arbitrary curve such as an ellipse or a parabola.

  In addition, about the position of the recessed parts 91 and 93, the vicinity of the location which the gate trace 92 and the fixed piece 2 approach through the retracting part 25 (near the edge of the fixed piece 2 provided with the retracting part 25) There is no particular limitation as long as the retracting portion 25 and the recesses 91 and 93 are separated from each other by the first distance D1 or more and the circuit breaker 1 can be reduced in size. For example, in FIG. 5 and the like, the concave portion 91 and the concave portion 93 (engraved mark 78) are unevenly distributed in the vicinity of one side edge of the resin base 71 (side edge on which the terminal 41 of the movable piece 4 protrudes). Although illustrated, they may be provided near different sides. Moreover, the aspect unevenly distributed in the vicinity of the edge | side (edge edge | side where the terminal 22 of the fixed piece 2 protrudes, or an edge | side orthogonal to it) different from the illustrated form may be sufficient. Moreover, it may be distributed in the vicinity of each side. Considering that the strength and rigidity of the breaker 1 are increased, as shown in FIGS. 5, 12, and 14 (excluding FIG. 14 (e)), the recesses 91, A configuration in which 93 is provided, that is, a simple configuration in which the edge of the resin base 71 is closed over the entire circumference and the side surface of the resin base 71 is not opened by the recesses 91 and 93 is more preferable. In particular, even when a multi-cavity mold is applied so that a large number of resin bases 71 can be molded simultaneously, the side surfaces or bottom surfaces of the recesses 91 and 93 are formed on the resin base 71 in consideration of the processability of the molds. A simple form in which the concave portions 91 and 93 are provided at positions that do not reach the edge side is preferable. In order to reduce the size of the breaker 1, the edge of the fixed piece 2 and the recesses 91, 93 of the resin base 71 are brought close to each other so that the retracting portion 25 and the recesses 91, 93 overlap on the bottom surface. desirable.

  The present invention is not limited to the configuration of the embodiment described above, and at least the outer surface of the support portion 23 of the fixed piece 2 is inclined toward the inner side of the resin base 71 and embedded in the resin base 71. 29a or 29b may be formed.

  Further, in order to suppress the deformation of the support portion 23, the tip portions 23a, 27b and the inclined portions 29a, 29b are replaced with or added to the extended portions 27a, 27b and the inclined portions 29a, 29b. You may comprise so that the contact area of the support part 23 and the resin base 71 may be ensured by forming a micro recessed part or convex part in the side edge part 23b and the extension parts 27a and 27b. Further, a similar effect can be obtained even if the surface of the tip portion 23a, the side end portion 23b, and the extending portions 27a and 27b that are in contact with the resin base 71 is roughened.

  Moreover, in FIG. 1 etc., the movable piece 4 is a form which has the structure of the through-hole 45, the step bending part 46, and the constriction part 49, However, Any or all of these structures may be abolished. . For example, when the through hole 45 is discarded, the projection 74a of the resin base 71 is also discarded. Moreover, when the step bending part 46 is abolished, the terminal 41 becomes a flat shape. In this configuration, by eliminating the step bending portion 46, the longitudinal dimension of the movable piece 4 and the resin base 71 can be reduced, and the breaker 1 can be further reduced in size. Further, when the constricted portion 49 is eliminated, the movable piece 4 is formed to have a uniform width from the contact portion 42 to the terminal 41, and the shape of the positioning portion 75 of the resin base 71 is changed accordingly. As described above, the shapes of the contact portion 42 of the movable piece 4, the contact portion 74 of the resin base 71, the contact portion 79 of the cover member 72, and the like are not limited to those shown in FIG. is there. Further, the shapes of the thermally responsive element 5 and the storage portion 73 are not limited to those shown in FIG. 1 and can be changed as appropriate.

  Further, the number of protrusions provided on the support portion 23 is not particularly limited. For example, only the protrusion 24 a may be provided, or another protrusion may be added to a location adjacent to the fixed contact 21, the center portion of the support portion 23, or the like. Furthermore, the structure which arrange | positions another component between the PTC thermistor 6 and the fixed piece 2 may be sufficient. In this case, the support portion 23 supports the PTC thermistor 6 via the separate part. Moreover, in the support part 23, one part or all protrusions may be abolished.

  Moreover, the joining method of the resin base 71 and the cover member 72 is not limited to ultrasonic welding, and can be appropriately applied as long as both are firmly joined. For example, a liquid or gel adhesive may be applied, filled, and cured to bond them together. Further, the case 7 is not limited to the form constituted by the resin base 71 and the cover member 72 and the like, but may be any form as long as the movable piece 4 is sandwiched and held by two or more parts. In this case, one is the first case and the other is the second case.

  Moreover, the structure which forms the movable piece 4 and the thermally responsive element 5 integrally by forming the movable piece 4 with a bimetal or a trimetal etc. may be sufficient. In this case, the heat transfer part is formed in the integrated movable piece, the structure of the breaker is simplified, and further miniaturization can be achieved.

  Further, as shown in JP-A-2005-203277, the movable piece 4 is structurally separated into the terminal 41 side and the movable contact 3 side in the contact portion 42 or the vicinity thereof. The invention may be applied. Further, the arm terminal and the movable arm may be fixed by welding or the like.

  Further, the breaker 1 of the present invention can be widely applied to secondary battery packs, safety circuits for electric devices, and the like. FIG. 15 shows the secondary battery pack 100. The secondary battery pack 100 includes a secondary battery 101 and a breaker 1 provided in the output terminal circuit of the secondary battery 101. FIG. 16 shows a safety circuit 102 for electrical equipment. The safety circuit 102 includes a breaker 1 in series in the output circuit of the secondary battery 101.

DESCRIPTION OF SYMBOLS 1 Breaker 2, 2A, 2B Fixed piece 3 Movable contact 4 Movable piece 5 Thermally responsive element 7 Case 8 Cover piece 21 Fixed contact 23 Support part 23a Tip part 23b Side edge part 24a, 24b Protrusion 26 Side part 28a, 28b Bending part 29a, 29b Inclined part 91, 93 Concave part 101 Secondary battery 102 Safety circuit

Claims (10)

A fixed piece having a fixed contact;
A movable piece having a movable contact, and pressing the movable contact against the fixed contact;
A thermally responsive element that operates the movable piece so that the movable contact is separated from the fixed contact by being deformed with a temperature change;
A positive characteristic that is inserted between the thermally responsive element and the fixed piece and electrically connects the movable piece and the fixed piece via the thermally responsive element when the movable contact is separated from the fixed contact. The thermistor,
In the breaker comprising the fixed piece, the movable piece, the case that accommodates the thermally responsive element and the positive temperature coefficient thermistor,
The fixed piece includes a terminal that is electrically connected to the outside, and a support portion that supports the positive temperature coefficient thermistor,
A breaker, wherein an outer surface of the support portion is inclined toward an inner side of the case and is embedded in the case.   The breaker according to claim 1, wherein the fixed piece has a curved portion bent toward the inside of the case at a base end of the inclined portion.   A plurality of protrusions that protrude toward the positive temperature coefficient thermistor and abut against the positive temperature coefficient thermistor are formed on the support portion, and the inclined portion is adjacent to at least one of the plurality of protrusions. The breaker according to claim 1, wherein the breaker is formed at a place.   At least one of the plurality of protrusions is formed in an area overlapping with a contact area between the thermal response element and the positive temperature coefficient thermistor in plan view when the thermal response element is deformed. The breaker according to claim 3.   The breaker according to any one of claims 1 to 4, wherein the inclined portion is formed to protrude from a distal end portion of the support portion.   The breaker according to any one of claims 1 to 5, wherein the inclined portion is formed to protrude from a side end portion of the support portion.   The breaker according to any one of claims 1 to 6, wherein the fixed piece has a side end portion formed along an edge of the positive temperature coefficient thermistor. The case has a recess recessed from a peripheral portion,
The breaker according to claim 7, wherein the end portion is formed by retracting from a concave portion of the case.   A safety circuit for electrical equipment, comprising the breaker according to any one of claims 1 to 8.   A secondary battery circuit comprising the breaker according to any one of claims 1 to 8.

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