JP5886600B2 - Breaker and method of manufacturing breaker - Google Patents

Description

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

  Conventionally, a breaker has been used as a protection device 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. A breaker used as such a protection device is required to operate accurately following a change in temperature and have a stable resistance value when energized in order to ensure the safety of the device.

  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 shields 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 circuit breaker shown in the same document includes a fixed piece (base terminal), a movable piece (movable arm), a thermally responsive element, a PTC thermistor and the like housed in a resin case. Is used by being connected to an electric circuit of an electric device.

WO2011-105175

  In order to ensure stable temperature followability and resistance (contact resistance between the fixed contact and the movable contact) in a circuit breaker that has been reduced in size, it is provided at the fixed contact provided on the fixed piece and the tip of the movable piece. It is necessary to stabilize the relative positional relationship (posture) with the movable contact. In the breaker having the configuration shown in Patent Document 1, since the fixed piece is fixed to the resin case, the accuracy with which the movable piece is incorporated into the resin case becomes important. This is because if the posture of the movable piece with respect to the resin case is slightly changed, the position of the movable contact provided at the tip thereof is changed, which affects the relative positional relationship with the fixed contact.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a breaker capable of realizing downsizing while ensuring stable temperature followability and resistance value.

  In order to achieve the above object, a breaker according to the present invention includes a fixed piece having a fixed contact, an elastic portion that is elastically deformed, and a movable contact at a tip of the elastic portion, and the movable contact is used as the fixed contact. A movable piece that is pressed and brought into contact; a thermally responsive element that operates the movable piece so that the movable contact is separated from the fixed contact by being deformed as the temperature changes; and the fixed piece, the movable piece, and the thermal responsive element In a breaker including a first case that accommodates an element and a second case that is attached to the first case, the second case has an inclined surface that contacts a part of the movable piece, and the first case The case has a first positioning portion that contacts another part of the movable piece pushed by the slope and positions the movable piece.

  The breaker according to the present invention includes a fixed piece having a fixed contact, an elastic part that is elastically deformed, and a movable contact at a tip of the elastic part, and the movable contact is pressed against the fixed contact to make contact. A first piece that accommodates the piece, 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, and the fixed piece, the movable piece, and the thermally responsive element. In a breaker including a case and a second case attached to the first case, the movable piece has a slope contacting a part of the second case, and the first case is the movable piece. And a first positioning portion for positioning the movable piece.

  In this invention, it is preferable that the first positioning portion is provided continuously or at a plurality of locations along a direction perpendicular to a direction in which the movable piece contacts and is pressed against the second case. .

  In this invention, it is preferable that the first case has a second positioning portion that contacts a part of the second case and positions the second case.

  In this invention, it is preferable that the second positioning portion is provided continuously or at a plurality of locations along a direction perpendicular to a direction in which the movable piece contacts and is pressed against the second case. .

  In this invention, the movable piece has a through-hole penetrating in the thickness direction of the movable piece on the opposite side of the movable contact across the elastic portion, and the first case is inserted into the through-hole. It is preferable to have a protrusion.

  In this invention, it is preferable that the first case and the second case are joined by ultrasonic welding.

  In this invention, it is preferable that the protrusion of the first case is joined to the inner wall surface of the second case.

  According to the breaker of the present invention, the slope formed in the second case contacts a part of the movable piece, and the movable piece is pushed in a predetermined direction. At this time, the other part of the movable piece comes into contact with the first positioning portion of the first case. Thereby, a movable piece is correctly positioned by the 1st positioning part, and the attitude | position of the movable piece with respect to a 1st case is stabilized. Accordingly, variation in the relative positional relationship between the movable contact and the fixed contact provided at the tip of the movable piece is suppressed, and the breaker can be downsized while ensuring stable temperature followability and resistance value. it can.

  Further, in the form in which the inclined surface formed on the movable piece abuts a part of the second case and the movable piece is pushed in a predetermined direction, the breaker is ensured in the same manner as described above while ensuring stable temperature followability. Can be miniaturized.

  Further, according to the embodiment in which the first positioning portions are provided continuously or at a plurality of locations along the direction perpendicular to the direction in which the movable piece is pressed, the displacement due to the rotation of the movable piece with respect to the first case is prevented. Can be suppressed. Thereby, the relative positional relationship between the movable contact and the fixed contact can be further stabilized.

  Moreover, according to the form which the 2nd positioning part of a 1st case and a part of 2nd case contact | abut, a 2nd case is correctly positioned with respect to a 1st case. Thereby, the contact state of the movable piece and the second case is stabilized, and variations in the posture of the movable piece can be suppressed.

  Further, according to the aspect in which the second positioning portions are provided continuously or at a plurality of locations along the direction perpendicular to the direction in which the movable piece is pressed, the displacement due to the rotation of the second case with respect to the first case Can be suppressed. Thereby, the contact state of the movable piece and the second case can be further stabilized, and variation in the posture of the movable piece can be further suppressed.

  Further, according to the embodiment in which the through hole through which the protrusion of the first case is inserted is provided in the movable piece, the work of assembling the movable piece into the first case can be easily performed. Even in this case, the stability of the posture of the movable piece relative to the first case is maintained by the action of the movable piece pushed through the slope and the first positioning portion.

  Moreover, according to the form in which the first case and the second case are joined by ultrasonic welding, the first case and the second case are joined easily and firmly, and the relative position between the movable contact and the fixed contact The relationship can be further stabilized.

  Moreover, according to the form in which the protrusion of the first case is joined to the inner wall surface of the second case, the joining structure of the first case and the second case around the through hole of the movable piece becomes strong. Thereby, the posture of the movable piece can be further stabilized.

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. The perspective view which shows a mode that a movable piece is integrated in a resin base. Sectional drawing which shows a mode that a cover member is mounted | worn with a resin base. (A) is sectional drawing which shows the state in which a movable piece is pushed by a cover member, (b) is the top view which saw through the cover member in the same state. Sectional drawing of the breaker with which the cover member was mounted | worn.

  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 resin case 7 that accommodates a PTC thermistor 6. The resin 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, and the like.

  The fixed piece 2 is formed by pressing a metal plate mainly composed of phosphor bronze (in addition, a metal plate such as copper-titanium alloy, white or brass), and is embedded in the resin base 71 by insert molding. ing. A terminal 22 electrically connected to the outside is formed at one end of the fixed piece 2, and a PTC thermistor 6 is placed in the vicinity of the other end. The PTC thermistor 6 is placed on convex dowels (small protrusions) formed at three locations in the vicinity of the other end of the fixed piece 2. 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 73 formed above. The terminal 22 protrudes outward from one end of the resin base 71.

  The movable piece 4 is formed in an arm shape by pressing a metal plate equivalent to the fixed piece 2. A terminal 41 that is electrically connected to the outside is formed at one end in the longitudinal direction of the movable piece 4 and protrudes outward from the resin base 71. In the present embodiment, the movable piece 4 is bent in a crank shape at a step bending portion 46 inside the resin case 7 in order to make the height of the terminal 22 of the fixed piece 2 and the terminal 41 of the movable piece 4 uniform. . 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 made of the same material as the fixed contact 21 and is joined to the tip of the movable piece 4 by a technique such as welding. The movable piece 4 has a fixed portion 42 (corresponding to the base end of the arm-shaped movable piece 4) and an elastic portion 43 between the movable contact 3 and the terminal 41. The movable piece 4 is fixed by being sandwiched between the resin base 71 and the cover member 72 in the fixed portion 42, and the elastic portion 43 is elastically deformed, whereby the movable contact 3 formed at the tip thereof is pressed against the fixed contact 21 side. Thus, the fixed piece 2 and the movable piece 4 can be energized.

  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 74 of the resin base 71 is inserted, a step bent portion 46 formed in a crank shape, and a step bent portion 46. A pair of engaging portions 48 that are engaged with the formed slope 47 and the first positioning portion 75 of the resin base 71 are formed. The through hole 45, the step bent portion 46, the inclined surface 47, and the engaging portion 48 are provided on the side opposite to the movable contact 3 across the elastic portion 43, that is, on the terminal 41 side with respect to the elastic portion 43. The slope 47 is continuously formed at a place other than the slope 47 along a direction perpendicular to the longitudinal direction of the movable piece 4. The engaging portions 48 are provided at two locations along a direction perpendicular to the longitudinal direction of the movable piece 4.

  In addition, a pair of small protrusions 44 are formed on the lower surface of the elastic portion 43 so as to face the thermally responsive element 5. The small protrusion 44 and the thermal response element 5 come into contact with each other, and the deformation of the thermal response element 5 is transmitted to the elastic portion 43 through the small protrusion 44 (see FIGS. 2 and 3). The material of the movable piece 4 is preferably a material mainly composed of phosphor bronze. In addition, a conductive elastic material such as copper-titanium alloy, white or brass may be used. Note that the movable piece 4 is curved or bent at the elastic portion 43 by press working. The degree of bending or bending is not particularly limited as long as the thermally responsive element 5 can be accommodated, and may be set as appropriate in consideration of the elastic force at the operating temperature and the return temperature, the pressing force of the contacts, and the like.

  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, and stainless steel including 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 kinds of materials made of various alloys having different coefficients of thermal expansion 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 shape is not particularly limited as long as these properties are not impaired.

  The resin base 71 and the cover member 72 constituting the resin case 7 are formed of a resin such as flame retardant polyamide, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), or polybutylene terephthalate (PBT) having excellent heat resistance. ing. The resin base 71 is formed with an opening 73 for accommodating the fixed piece 2, the movable piece 4, the thermally responsive element 5, the PTC thermistor 6, and the like. 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 opening 73, so that the thermal responsive element 5 is reversely warped. It is guided at times.

  The resin base 71 is fitted with a projection 74 inserted through the through hole 45 of the movable piece 4, a pair of first positioning portions 75 for positioning the movable piece 4, and a convex portion 79 of the cover member 72. A pair of concave portions (second positioning portions) 76. The first positioning portions 75 are provided at two locations along a direction perpendicular to the longitudinal direction of the movable piece 4. In the present embodiment, a part of the side wall of the resin base 71 constitutes the first positioning portion 75. The concave portions 76 are also provided at two locations along the direction perpendicular to the longitudinal direction of the movable piece 4. In addition, the 1st positioning part 75 and the recessed part 76 may be provided in three or more places. In this case, three or more engaging portions 48 corresponding to the first positioning portions 75 and convex portions 79 corresponding to the concave portions 76 are also provided.

  The cover member 72 includes a stepped portion 77 projecting from the inner wall surface thereof into a shape corresponding to the stepped bent portion 46 of the movable piece 4, a slope 78 (see FIG. 5) formed on the stepped portion 77, and a concave portion of the resin base 71. And a convex portion 79 to be inserted into 76. The slope 78 corresponds to the slope 47 of the movable piece 4 and is formed continuously along a direction perpendicular to the longitudinal direction of the movable piece 4. Two convex portions 79 are provided at positions corresponding to the concave portions 76 of the resin base 71.

  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 phosphor bronze or a metal plate such as stainless steel. As shown in FIGS. 2 and 3, the cover piece 8 is in contact with the upper surface of the movable piece 4 as appropriate to restrict the movement of the movable piece 4, and the cover member 72 and the rigidity of the resin case 7 as a casing are also provided. Increase strength.

  As shown in FIG. 1, a cover member 72 is formed on the upper surface of the resin base 71 so as to close the opening 73 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. Installed. 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 how the movable piece 4 is incorporated into the resin base 71. The movable piece 4 is guided into the openings 73 a and 73 b of the resin base 71 and incorporated into the resin base 71. At this time, the protrusion 74 of the resin base 71 is inserted into the through hole 45 formed in the movable piece 4. Thereby, since the movable piece 4 is guided by the protrusion 74, the temporary alignment of the movable piece 4 with respect to the resin base 71 is made.

  In this temporary alignment stage, it is not necessary that the movable piece 4 is accurately positioned with respect to the resin base 71. Further, the movable piece 4 is placed on the resin base 71 so as to be finally aligned in a later process, and is not fixed. In addition, the positions, shapes, dimensions, and the like of the openings 73a and 73b and the protrusions 74 of the resin base 71 are such that the movable piece 4 can be easily guided from the position where provisional alignment is performed to the fixed position where the positioning is completely performed. It is formed in a similar shape to the corresponding part of the movable piece 4.

  FIG. 5 shows a state in which the cover member 72 is attached to the resin base 71 in a cross section including the concave portion 76 and the convex portion 79. The cover member 72 inserts the convex portion 79 into the concave portion 76 and presses the stepped portion 77 of the cover member 72 against the stepped bent portion 46 of the movable piece 4 to align the movable piece 4 with the resin base 71. Installed.

  FIG. 6 shows how the movable piece 4 is pushed by the cover member 72 while being sandwiched between the resin base 71 and the cover member 72 when the cover member 72 is completely attached to the resin base 71. FIG. 2B is a perspective view of the cover member 72 in order to clearly show the internal structure of the breaker 1. When the cover member 72 is pressed in the direction of the resin base 71 while the cover member 72 is being attached to the resin base 71 (the white arrow in the figure), the slope 47 of the movable piece 4 and the slope 78 of the cover member 72. And abut. Since the inclined surface 47 and the inclined surface 78 are continuously formed along the direction perpendicular to the longitudinal direction of the movable piece 4, the movable piece is still pressed when the cover member 72 is pressed in the direction of the resin base 71. The four slopes 47 are pushed (biased) by the slope 78 of the cover member 72 in the longitudinal direction of the movable piece 4. As a result, the entire movable piece 4 is pushed and moved in the longitudinal direction, that is, the arrow A direction where the fixed piece 2 exists, and the engaging portion 48 abuts on and engages with the first positioning portion 75. As a result, the movable piece 4 that has been temporarily aligned by the protrusion 74 or the like in FIG. 5 is accurately positioned with respect to the resin base 71. That is, the error at the time of temporary alignment that occurs when the movable piece 4 is assembled with the resin base 71 is reduced, and the positioning error of the movable piece 4 with respect to the resin base 71 is substantially reduced. 1 The positioning portion 75 and the engaging portion 48 of the movable piece 4 can be limited to a dimensional error at the time of manufacturing.

  6B, the distance from the engaging portion 48 of the movable piece 4 to the contact location of the movable contact 3 (see FIG. 2) and the contact location of the fixed contact 21 from the first positioning portion 75 of the resin base 71. The distance to (see FIG. 2) is set equal in plan view. Therefore, when the movable piece 4 is accurately positioned, the movable contact 3 and the fixed contact 21 come into contact with each other at an appropriate contact location. Thereby, the contact resistance between both at the time of electricity supply is optimized.

  In the present embodiment, a pair of the engaging portion 48 and the first positioning portion 75 are provided along the short direction of the movable piece 4 (the vertical direction in FIG. 6B). Further, since the pair of engaging portions 48 and the pair of first positioning portions 75 are located on the outer side of the slope 47 and the slope 78 in the short direction of the movable piece 4, the movable piece 4 is rotated. Deviation from the resin base 71 can be suppressed. This also prevents interference between the tip of the movable piece 4 and the resin base 71 even if the clearance between the tip of the movable piece 4 and the opening 73b of the resin base 71 is set small. Further downsizing can be achieved.

  The slope 78 of the cover member 72 that presses the slope 47 of the movable piece 4 is pushed back from the slope 47 by the reaction, and the entire cover member 72 has a direction opposite to the arrow A direction, that is, the terminal 41 of the movable piece 4 exists. Move in the direction of arrow B. Along with this, the concave portion 76 of the resin base 71 and the convex portion 79 of the cover member 72 abut on the wall surface on the arrow B direction side. As a result, the cover member 72 is accurately positioned with respect to the resin base 71. In the present embodiment, a pair of concave portions 76 and convex portions 79 are provided along the short direction of the movable piece 4. Further, since the pair of concave portions 76 and the pair of convex portions 79 are located on the outer side of the slope 47 and the slope 78 in the short direction of the movable piece 4, Can be suppressed. As a result, the posture of the inclined surface 78 with respect to the resin base 71 is stabilized, and the movable piece 4 can be pressed in an accurate direction, and the movable piece 4 by the inclined surface 47, the inclined surface 78, the first positioning portion 75, and the engaging portion 48. In combination with the positioning action, the posture of the movable piece 4 can be further stabilized.

  As shown in FIG. 7, when the cover member 72 is completely attached to the resin base 71, ultrasonic vibration is applied to one or both of the resin base 71 and the cover member 72, so that the resin base 71 and the cover member 72 are provided. Is welded. At this time, the tip of the protrusion 74 of the resin base 71 contacts the inner wall surface of the cover member 72 and is joined by ultrasonic welding. Accordingly, the movable piece 4 is firmly joined from above and below by the resin base 71 and the cover member 72 around the through hole 45, that is, at the fixed portion 42. Thereby, the movable piece 4 is fixed at a fixed position (position where it should be) with respect to the resin base 71. Even after the cover member 72 is welded to the resin base 71 and the movable piece 4 is fixed, the inclined surface 47 and the inclined surface 78 remain in contact with each other, and the movable piece 4 continues to be pushed in the direction of arrow A. Accordingly, the first positioning portion 75 and the engaging portion 48 maintain the engaged state, and the position and posture of the movable piece 4 with respect to the resin base 71 continue to be maintained normally.

  As described above, according to the breaker 1 of the present embodiment, when the cover member 72 is attached to the resin base 71, the slope 78 formed on the cover member 72 contacts the slope 47 of the movable piece 4, and the slope When the direction of the force is changed by 78 and 47, the movable piece 4 is pushed and moved in the arrow A direction which is the longitudinal direction. Accordingly, the engaging portion 48 of the movable piece 4 is engaged with the first positioning portion 75 of the resin base 71. Accordingly, the movable piece 4 is accurately positioned by the first positioning portion 75, and the posture of the movable piece 4 with respect to the resin base 71 is stabilized. Therefore, the variation in the relative positional relationship between the movable contact 3 and the fixed contact 21 provided at the tip of the movable piece 4 is suppressed, and the breaker 1 is reduced in size while ensuring stable temperature follow-up and resistance. Can be

  In addition, since the first positioning portions 75 are provided at a plurality of locations along the direction perpendicular to the arrow A direction in which the movable piece 4 is pressed, the displacement due to the rotation of the movable piece 4 with respect to the resin base 71 can be suppressed. Thereby, the relative positional relationship between the movable contact 3 and the fixed contact 21 can be further stabilized.

  Further, since the concave portion 76 of the resin base 71 and the convex portion 79 of the cover member 72 are engaged, the cover member 72 is accurately positioned with respect to the resin base 71. The contact state is stable, and variations in the posture of the movable piece 4 can be suppressed.

  In addition, since the recesses 76 are provided at a plurality of locations along the direction perpendicular to the arrow A direction in which the movable piece 4 is pressed, displacement due to the rotation of the cover member 72 with respect to the resin base 71 can be suppressed. Thereby, the contact state of the movable piece 4 and the cover member 72 is further stabilized, and variation in the posture of the movable piece 4 can be further suppressed.

  Moreover, since the through hole 45 through which the protrusion 74 of the resin base 71 is inserted is provided in the movable piece 4, the work of assembling the movable piece 4 into the resin base 71 can be easily performed. Even in this case, the stability of the posture of the movable piece 4 with respect to the resin base 71 is maintained by the action of the movable piece 4 pushed through the inclined surfaces 47 and 78 and the first positioning portion 75.

  Further, since the resin base 71 and the cover member 72 are joined by ultrasonic welding, the resin base 71 and the cover member 72 are joined easily and firmly, and the relative positional relationship between the movable contact 3 and the fixed contact 21 is obtained. Can be further stabilized. Further, since the protrusion 74 of the resin base 71 is joined to the inner wall surface of the cover member 72, the joining structure of the resin base 71 and the cover member 72 around the through hole 45 of the movable piece 4 is strengthened. Thereby, the posture of the movable piece 4 can be further stabilized.

  Moreover, since the fixed piece 2 is embedded in the resin base 71 by insert molding, the fixed piece 2 is firmly fixed to the resin base 71. Thereby, the relative positional relationship between the fixed contact 21 and the movable contact 3 can be further stabilized.

  The present invention is not limited to the configuration of the above embodiment, and the engaging portion 48 of the movable piece 4 pressed by at least the inclined surfaces 47 and 78 and the first positioning portion 75 of the resin base 71 are engaged, and the movable piece What is necessary is just to be comprised so that 4 may be positioned.

  The present invention can be modified in various ways. For example, the slopes 47 and 78 may be provided on either the movable piece 4 or the cover member 72. When the slope 47 is provided only on the movable piece 4, the slope 47 comes into contact with a part of the step 77 of the cover member 72 and the like, and the movable piece 4 is pushed in the arrow A direction. At this time, a part of the cover member 72 that comes into contact with the inclined surface 47 is not limited to the stepped portion 77 having the inclined surface 78. For example, a protrusion, a hole, a notch, etc. The position and shape are not limited as long as the movable piece 4 can be pushed in a predetermined direction by contact. On the other hand, when the slope 78 is provided only on the cover member 72, a part of the step bending portion 46 and the like of the movable piece 4 comes into contact with the slope 78, and the movable piece 4 is pushed in the arrow A direction. At this time, the part of the movable piece 4 that contacts the inclined surface 78 is not limited to the step bending portion 46 having the inclined surface 47. For example, a protrusion, a hole, a notch, etc. As long as the movable piece 4 can be pushed in a predetermined direction by contact, the position and shape thereof are not limited.

  Further, the direction in which the movable piece 4 is pushed by the inclined surfaces 47, 78 and the like is not limited to the arrow A direction that is the longitudinal direction of the movable piece 4. By changing the direction of the slopes 47 and 78, it can be set in an arbitrary direction. Accordingly, the positions of the first positioning portion 75, the engaging portion 48, the concave portion 76, and the convex portion 79 are also changed as appropriate. Further, the positions where the inclined surfaces 47 and 78 are provided are not limited to the step bending portion 46 and the step portion 77, and can be arranged at any place as long as the movable piece 4 is pushed in a predetermined direction.

  Moreover, the 1st positioning part 75 may be provided in arbitrary positions not only on the side wall of the resin base 71 but in arbitrary positions. For example, you may provide continuously along the direction perpendicular | vertical with respect to the direction where the movable piece 4 is pushed. Accordingly, the engaging portion corresponding to the first positioning portion 75 is also moved / deformed. More specifically, a portion of the resin base 71 that faces the step bending portion 46 may be formed in a shape corresponding to the step bending portion 46, and this may be used as the first positioning portion 75. In this case, the step bent portion 46 corresponds to the engaging portion 48. Even in this case, the rotation of the movable piece 4 is further suppressed by forming the first positioning portion 75 so as to be continuous in the direction perpendicular to the direction in which the movable piece 4 is pushed across the inclined surfaces 47 and 78. it can.

  Further, the portion that contacts the first positioning portion 75 and positions the movable piece 4 (hereinafter referred to as a contact portion) is not limited to the engaging portion 48 that engages with the first positioning portion 75, but the first positioning portion If it is the structure which contacts 75 and positions the movable piece 4, it will not specifically limit. For example, the 1st positioning part 75 and the contact part may be comprised by the recessed part and the convex part corresponding to it, a notch, the convex part corresponding to it, or a through-hole, and the convex part corresponding to it. In each of these configurations, it is only necessary that one is formed in the first positioning portion 75 and the other is formed in the contact portion.

  The same applies to the position and shape of the second positioning portion. For example, a convex portion may be formed on the resin base 71 and a concave portion may be formed on the cover member 72. Even in this case, the rotation of the cover member 72 can be further suppressed by forming the second positioning portion so as to be continuous in the direction perpendicular to the direction in which the movable piece 4 is pushed across the inclined surfaces 47 and 78. .

  In this embodiment, the self-holding circuit using the PTC thermistor 6 is provided. However, the present invention can be applied to a configuration in which such a configuration is omitted, and ensures stable temperature follow-up and resistance value. Meanwhile, the breaker 1 can be reduced in size. 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 configuration of the breaker is simplified, and further miniaturization can be achieved.

  Further, the inclined surface 47 and the inclined surface 78 are not limited to a form in which the inclination angle is constant, and may be an aspect in which the inclination angle gradually increases or decreases. Further, the resin case 7 is not limited to the form constituted by the resin base 71 and the cover member 72, but may be any other form as long as it is constituted by two parts. In this case, one is the first case and the other is the second case.

  In addition, the present invention may be applied to a structure that is divided into the terminal 41 side and the movable contact 3 side at or near the fixed portion 42 as disclosed in JP-A-2005-203277. Furthermore, the present invention can also be applied to a form having two movable contacts (the first contact 141 and the second contact 142 in the same document) as disclosed in JP-A-2006-331705. .

DESCRIPTION OF SYMBOLS 1 Breaker 2 Fixed piece 3 Movable contact 4 Movable piece 5 Thermally responsive element 21 Fixed contact 43 Elastic part 45 Through hole 47 Slope 48 Engagement part 71 Resin base (1st case)
72 Cover member (second case)
74 Projection 75 First positioning portion 76 Recessed portion (second positioning portion)
78 Slope 79 Convex

Claims (7)

A fixed piece having a fixed contact;
A movable piece having an elastic part that is elastically deformed and a movable contact at a tip of the elastic part, 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 first case that houses the fixed piece, the movable piece, and the thermally responsive element;
In a breaker comprising a second case attached to the first case,
The movable piece includes a terminal that is electrically connected to the outside, a step bending portion that is provided inside the first case, and that arranges the elastic portion and the terminal in steps in the thickness direction of the movable piece. And the elastic portion is retracted in a direction away from the thermally responsive element inside the first case,
The second case has an inclined surface that comes into contact with the step bending portion of the movable piece,
The first case includes a first positioning portion that contacts the other part of the movable piece and positions the movable piece pressed by the inclined surface. The breaker according to claim 1, wherein the movable piece is pushed by the slope in a direction in which the fixed piece exists .   The first positioning portion is provided continuously or at a plurality of locations along a direction perpendicular to a direction in which the movable piece is pressed against the second case. The breaker of Claim 1 or Claim 2. A method for manufacturing a breaker according to any one of claims 1 to 3,
A first step of sequentially placing the thermally responsive element and the movable piece on the first case;
A second step of placing the second case on the first case and bringing the inclined surface into contact with the stepped bending portion;
A third step of biasing the movable piece by the inclined surface by pressing the second case in the direction of the first case;
And a fourth step of positioning the movable piece with respect to the first case by engaging another part of the movable piece with the first positioning portion of the first case. Manufacturing method. A fifth step of biasing the second case by a reaction of biasing the movable piece by the slope in the third step;
5. The sixth step of positioning the second case with respect to the first case by engaging a part of the second case with the first case. Breaker manufacturing method. The method for manufacturing a breaker according to claim 4 or 5, further comprising a seventh step of joining the first case and the second case by ultrasonic welding. The movable piece has a through-hole penetrating in the thickness direction of the movable piece on the opposite side of the movable contact across the elastic portion,
The first case has a protrusion inserted into the through hole,
The method for manufacturing a breaker according to claim 6, wherein, in the seventh step, the protrusion is joined to an inner wall surface of the second case.

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