Thermal protector

Abstract

This thermal protector is provided with: a resin base member and a cover member; the fixed contact and the movable contact are arranged in the accommodating space; a fixed member provided with a fixed contact; a movable member provided with a movable contact; and a thermal actuator which is housed in the housing space, and which deforms by being heated, thereby causing a force in the direction in which the movable contact is separated from the fixed contact to act on the movable member. The base member has a protruding portion provided on the base member and protruding from a surface of the base member. The cover member has a through-hole portion formed at a position corresponding to the protruding portion and formed so as to penetrate through the cover member. The base member and the cover member are fixed to each other by projecting the projecting portion toward the outside of the cover member through the through-hole portion and forming a thermally swaged portion thermally swaged at the projecting portion.

Description

Technical Field

[0001] An embodiment of the present invention relates to a thermal protector. Background Art

[0002] The thermal protector contains a thermal element and a normally closed contact mechanism inside a housing member made of insulating resin. When abnormal heating is sensed, the thermal element is activated, thereby opening the contact mechanism to cut off the current. The housing member is formed by, for example, joining a cover member and a base member to each other. In such a conventional structure, the cover member and the base member are joined to each other by ultrasonically welding the peripheries of the cover member and the base member.

[0003] However, in the case of ultrasonic welding, for example, the cover member and the base member may be worn due to high-frequency vibration, and wear powder may be generated inside the housing member. Furthermore, when the wear powder generated inside the housing member enters between the contacts, the possibility of causing poor resistance, poor conduction, etc. becomes high, and as a result, the reliability of the thermal protector may be reduced.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-100054. Summary of the invention

[0007] Problem that the invention aims to solve

[0008] Therefore, the present invention provides a thermal protector capable of achieving improved reliability.

[0009] Solutions for solving problems

[0010] The thermal protector of the embodiment has: a base member, which is composed of a resin having electrical insulation and thermoplasticity; a cover member, which is composed of a resin having electrical insulation, is installed on the base member and forms a housing space between the base member and the cover member; a fixed contact and a movable contact, which are arranged in the housing space; a fixed member, which is provided with the fixed contact and is fixed to the base member; a movable member, which is provided with the movable contact and is configured to be deformable in the housing space and to cause a force in a direction of contacting the fixed contact to act on the movable contact; and a thermal element, which is accommodated in the housing space and deforms by being heated, thereby causing a force in a direction of the movable contact to move away from the fixed contact to act on the movable member. The base member has a protrusion provided on the base member and protruding from the surface of the base member. The cover member has a through hole formed at a position corresponding to the protrusion and penetrating the cover member. The protruding portion passes through the through hole portion and protrudes to the outside of the cover member, and a heat caulking portion that is heat caulked is formed at the protruding portion, so that the base member and the cover member are fixed to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a perspective view showing an example of a thermal protector according to an embodiment, in which a switch assembly, a first case, and a second case constituting the thermal protector are exploded and shown.

[0012] Figure 2 This is an example of a thermal protector according to an embodiment, and is a perspective view showing a switch assembly from the base member side.

[0013] Figure 3 This is an example of a thermal protector according to an embodiment, and is a perspective view showing a switch assembly from the cover member side.

[0014] Figure 4 This is a perspective view showing an example of a thermal protector according to an embodiment, showing a switch assembly from the cover member side, and is a view showing a state before a thermal caulking portion is formed on a protruding portion.

[0015] Figure 5 This is a perspective view showing an example of a thermal protector according to an embodiment, in which a switch assembly is exploded.

[0016] Figure 6 This is an example of a thermal protector according to an embodiment, and shows a plan view of a switch assembly from the cover member side.

[0017] Figure 7 This is a plan view showing an example of a thermal protector according to an embodiment, showing a state before a cover member, a contact member, and a clip are attached to a base member in a process of assembling a switch assembly.

[0018] Figure 8 is an example of a thermal protector according to one embodiment. Figure 6 The X8-X8 line shows a cross-sectional view.

[0019] Fig. 9 is an example of a thermal protector according to one embodiment. Figure 6 The X9-X9 line shows a cross-sectional view.

[0020] Fig.10 is an example of a thermal protector according to one embodiment, wherein the thermal element is Fig. 9 A cross-sectional view of a state in which the fixed contact and the movable contact are opened by deforming the state.

[0021] Fig.11 is an example of a thermal protector according to one embodiment, and is enlarged to show Fig.10 A cross-sectional view of the X11 section.

[0022] Fig.12 This is a cross-sectional view showing an example of a thermal protector according to an embodiment, in which a portion of a second housing and a portion of a first housing are cut away to show a housing state of a switch assembly.

[0023] Fig.13 is an example of a thermal protector according to one embodiment, and shows an enlarged view of Fig.12 A cross-sectional view of a portion taken along line X13-X13.

[0024] Fig.14 is an example of a thermal protector according to one embodiment, and shows an enlarged view of Fig.12 A cross-sectional view of a portion of the X14-X14 line.

[0025] Fig.15 is an example of a thermal protector according to one embodiment, and is enlarged to show Fig.12 A cross-sectional view of the X15 section. DETAILED DESCRIPTION

[0026] Hereinafter, one embodiment will be described with reference to the drawings.

[0027] The thermal protector of the present invention can be applied to, for example, a thermal protector for a three-phase motor in which the protected object is a three-phase motor. The thermal protector of the present invention is installed on the protected object and has the function of sensing the heat generated by the protected object and cutting off the current to the protected object when abnormal heat is generated. The thermal protector of the present invention can take, for example, a three-phase motor as the protected object. In this case, the thermal protector is connected to all windings on the neutral point side of the star-connected three-phase motor. Moreover, when the thermal protector senses abnormal heat generation of the three-phase motor, it cuts off all windings at the neutral point. In addition, the thermal protector of the present invention can be applied to both a thermal protector for a single-phase motor and a thermal protector for a device other than a motor as the protected object.

[0028] like Figure 1 As shown, the thermal protector 1 of this embodiment includes a second housing 2, a first housing 3, and a switch assembly 10. The switch assembly 10 is a main structure of the thermal protector 1 and has a function of cutting off the current when abnormal heating is sensed. Figure 2 and Figure 3 As shown, the switch assembly 10 is configured as a rectangular plate as a whole. In addition, in the following description, the length direction of the switch assembly 10 is sometimes referred to as the length direction of the switch assembly 10 and the thermal protector 1, and the direction perpendicular to the length direction is sometimes referred to as the width direction of the switch assembly 10 and the thermal protector 1. Moreover, the direction perpendicular to both the length direction and the width direction is sometimes referred to as the height direction or thickness direction of the switch assembly 10 and the thermal protector 1.

[0029] like Figure 5 As shown in FIG. 1 , the switch assembly 10 includes a fixed contact 12, a movable contact 13, a fixed member 20, a movable member 30, a thermal element 40, a base member 50, a cover member 60, a clip 70, and an abutment member 80. The base member 50 and the cover member 60 constitute a housing member as an outer shell of the switch assembly 10. The base member 50 and the cover member 60 are combined with each other to constitute the outer shell of the switch assembly 10, and as shown in FIG. Figure 8 and Fig. 9 As shown, a receiving space 11 is formed inside.

[0030] like Figure 5 As shown in the figures, the switch assembly 10 has two fixed contacts 12, two movable contacts 13, two fixed members 20, and one movable member 30. The fixed contacts 12, the movable contacts 13, a part of the fixed members 20, a part of the movable member 30, and the thermal element 40 are arranged in the accommodating space 11. The fixed contacts 12, the movable contacts 13, the fixed members 20, and the movable member 30 constitute a contact mechanism that is normally closed and opened by the action of the thermal element 40. The fixed contacts 12 and the movable contacts 13 can be formed using an alloy containing a metal with low resistance, such as gold, silver, or copper.

[0031] The fixing member 20 is fixed to the base member 50. The fixing member 20 is made of a long plate-shaped and conductive metal plate. The fixing member 20 can be made of a metal plate such as steel, copper, or stainless steel. Fig. 9 As shown, a portion of the fixing member 20 is embedded in the base member 50 by insert molding. Figure 5 As shown, the two fixing members 20 are arranged in parallel in a state of being separated from each other and buried in the base member 50 so as to be electrically insulated from each other.

[0032] like Fig. 9 As shown in the figures, one end of the fixing member 20 is exposed to the outside from the base member 50. The portion of the fixing member 20 exposed to the outside of the base member 50 is sometimes referred to as the fixing part side connection portion 21. The fixing part side connection portion 21 is connected to the power line connected to the device to be protected. In the case of the present embodiment, two phase power lines of the three-phase power lines connected to the device to be protected are connected to the fixing part side connection portions 21 of each of the two fixing members 20. The other end 22 of the fixing member 20 is partially exposed in the accommodation space 11. The fixed contact 12 is provided at the end 22 on the opposite side of the fixing part side connection portion 21, and is exposed in the accommodation space 11.

[0033] like Fig. 9 As shown in the figures, the movable member 30 is sandwiched between the base member 50 and the cover member 60 and supported in a cantilever beam shape. Among the parts of the movable member 30 other than the part sandwiched between the base member 50 and the cover member 60, a part is exposed to the outside of the base member 50 and the cover member 60, and the other part is exposed in the accommodation space 11.

[0034] The movable member 30 is preferably made of a spring alloy material having low electrical resistance and high heat resistance. For example, beryllium copper alloy, titanium copper alloy, Corson copper alloy, etc. can be used as the material of the movable member 30. Figure 5 and Figure 7 As shown, the movable member 30 is composed of a partially forked metal plate as a whole, for example. The length direction of the movable member 30 is consistent with the length direction of the switch assembly 10, and the width direction of the movable member 30 is consistent with the width direction of the switch assembly 10. The movable member 30 has a movable portion side connecting portion 31, a clamped portion 32, a fulcrum portion 33, two arm portions 34, and two or more (three in this case) insertion hole portions 35.

[0035] like Figure 7 , Figure 8 and Fig. 9As shown, the movable part side connection part 31 is provided at the unbranched end of the two ends of the movable member 30 and is exposed to the outside of the base member 50 and the cover member 60. The power line connected to the equipment to be protected is connected to the movable part side connection part 31. In the case of this embodiment, one phase power line of the three-phase power line connected to the equipment to be protected is connected to the movable part side connection part 31.

[0036] The clamped portion 32 is provided between the movable portion side connecting portion 31 and the arm portion 34. The clamped portion 32 is a portion that contacts the base member 50 or the cover member 60 when the movable member 30 is sandwiched between the base member 50 and the cover member 60, that is, a portion that receives a pressing force from the base member 50 and the cover member 60. The clamped portion 32 can be formed in a rectangular shape, for example, in a rectangular shape that is long in the width direction of the switch assembly 10.

[0037] The fulcrum portion 33 is a boundary portion between the clamped portion 32 and the arm portion 34. The arm portion 34 is a portion of the movable member 30 exposed in the housing space 11, and in this case, is a base point of the bifurcated portion. The arm portion 34 is configured to be deformable in the housing space 11 with the fulcrum portion 33 as a fulcrum, that is, to be able to swing in the thickness direction.

[0038] The movable contact 13 is provided near the top of the bifurcated portion of the movable member 30, that is, near the top of the arm portion 34, and at a position facing the corresponding fixed contact 12. When no external force is applied to the movable member 30, that is, when the switch assembly 10 is not assembled, the movable member 30 is formed in a shape that is bent so as to bulge toward the cover member 60 side. When the movable member 30 is assembled into the switch assembly 10, the movable contact 13 is fixed between the base member 50 and the cover member 60 in a state where the movable contact 13 is in contact with the fixed contact 12 and the arm portion 34 is elastically deformed with the fulcrum portion 33 as a fulcrum. The movable member 30 applies a force to the movable contact 13 in a direction of pressing the movable contact 13 toward the fixed contact 12 by the elastic force, that is, the restoring force, of the movable member 30.

[0039] The arm 34, when not receiving any external force other than the resistance from the fixed contact 12, presses the movable contact 13 against the fixed contact 12 by the elastic force of the movable member 30. In this case, the thermal protector 1 is in a closed state, that is, the fixed part side connection part 21 of the fixed member 20 and the connection part 31 of the movable member 30 are in electrical conduction. On the other hand, the arm 34 is in a state where the movable contact 13 moves away from the fixed contact 12, that is, the movable contact 13 moves away from the fixed contact 12. Fig. 9When an external force is applied in the upward direction of the paper surface and is greater than the elastic force of the movable member 30, the movable contact 13 is deformed in the direction away from the fixed contact 12, and as a result, the movable contact 13 is away from the fixed contact 12. In this case, the thermal protector 1 is in an open state, that is, the fixed part side connection part 21 of the fixed member 20 and the connection part 31 of the movable member 30 are electrically disconnected.

[0040] like Figure 5 and Figure 8 As shown in FIG. 1 , the insertion hole 35 is formed by penetrating the clamped portion 32 in the thickness direction. The insertion hole 35 is, for example, a circular, quadrilateral, or elliptical hole. In the present embodiment, the movable member 30 has three insertion holes 35. The three insertion holes 35 are arranged, for example, on a straight line along the length direction of the clamped portion 32, that is, the width direction of the movable member 30. Figure 7 As shown, one of the three insertion hole portions 35 is provided on the center line C in the width direction of the movable member 30 .

[0041] The thermal element 40 is received in the receiving space 11. Figure 8 As shown in FIG. 1 and FIG. 2 , when viewed in the thickness direction of the switch assembly 10, the switch assembly 10 is disposed between the fixed member 20 and the movable member 30. The thermal element 40 is formed of a bimetallic material and is in a rectangular plate shape. The thermal element 40 is not fixedly arranged in the accommodation space 11. The thermal element 40 is deformed by heat, so that a force in a direction in which the movable contact 13 is separated from the fixed contact 12 acts on the movable member 30.

[0042] like Fig. 9 As shown, the thermal element 40, when not deforming, is in a shape that is curved in an arc shape from the vertex 41 toward both ends of the length direction of the switch assembly 10 or in a disc shape that is curved on a spherical surface. The thermal element 40 deforms when subjected to a predetermined amount of heat. Fig.10 As shown in the figure, the bending direction is reversed. Then, the edge 42 on one end side of the switch assembly 10 in the thermal element 40 in the length direction contacts the vicinity of the fulcrum portion 33 of the movable member 30. In addition, the edge 43 on the other end side of the switch assembly 10 in the thermal element 40 in the length direction contacts the arm portion 34. A convex portion may also be provided at the portion of the arm portion 34 that is abutted by the edge 43.

[0043] In the following description, the side portion 42 that contacts the vicinity of the fulcrum portion 33 when the deformation action is performed among the sides 42, 43, 44 around the thermal element 40 is sometimes referred to as the rear side portion 42. In addition, the side portion 43 that contacts the arm portion 34 when the deformation action is performed among the sides 42, 43, 44 around the thermal element 40 is sometimes referred to as the front side portion 43. And, the side portion sandwiched between the rear side portion 42 and the front side portion 43 among the sides 42, 43, 44 around the thermal element 40 is sometimes referred to as the side side portion 44.

[0044] Here, if Fig.11 As shown, the vicinity of the fulcrum portion 33 is sandwiched by the base member 50 and the cover member 60, so it is difficult to deform even when subjected to the force from the thermal element 40. Therefore, when the thermal element 40 is deforming, it swings with the side portion 42 in contact with the vicinity of the fulcrum portion 33 as a fulcrum. Moreover, the side portion 43 in the thermal element 40 in contact with the arm portion 34 lifts the arm portion 34 toward the cover member 60. As a result, the movable contact 13 separates from the fixed contact 12 and switches to a state in which the thermal protector 1 is opened, that is, a state in which the power supply to the device to be protected is cut off.

[0045] like Fig.11 As shown in FIG. 1 , in the portion where the movable member 30 is sandwiched between the cover member 60 and the base member 50, i.e., the portion in contact with the clamped portion 32, the cover member 60 extends further toward the top end side of the movable member 30, i.e., the arm portion 34 side, than the base member 50. That is, the rear edge 42 of the thermal element 40 and the portion in contact with the movable member 30 in the cover member 60 are arranged in a plan view. Fig.11 overlap in part A of area.

[0046] According to this structure, when the thermal element 40 deforms and the rear edge 42 of the thermal element 40 contacts the movable member 30, the cover member 60 can bear the force applied to the movable member 30 from the rear edge 42 in the region A of the cover member 60. Therefore, even when the boundary portion 62 between the portion in contact with the movable member 30 and the portion not in contact with the movable member 30 in the cover member 60 is square, it is possible to suppress a large shear force from acting on the portion in contact with the boundary portion 62 of the movable member 30, and as a result, it is possible to suppress deformation and breakage of the movable member 30.

[0047] The base member 50 is made of, for example, a resin having electrical insulation and thermoplasticity. The base member 50 is preferably made of, for example, a member having heat resistance and electrical insulation and good adhesion of an epoxy adhesive. The base member 50 can be made of, for example, polyphenylene sulfide (PPS) mixed with about 30% to 40% of glass fiber. The base member 50 is generally formed in, for example, a rectangular plate shape.

[0048] like Figure 5 and Figure 7 to Figure 9 As shown in FIG. 1 , the base member 50 is configured to include a recessed portion 51, a support portion 52, a plurality of protruding portions 531, 532, 533, a contact hole portion 54, a rear wall portion 55, a side wall portion 56, and an intermediate wall portion 57. The recessed portion 51, the support portion 52, the plurality of protruding portions 531, 532, 533, the contact hole portion 54, the rear wall portion 55, the side wall portion 56, and the intermediate wall portion 57 are integrally configured by resin molding. The protruding portions 531 and 533 are provided on one side of the base member 50 in the longitudinal direction in a plan view, and the protruding portion 532 is provided on the other side of the base member 50 in the longitudinal direction.

[0049] The recessed portion 51 is a portion formed by making the surface of the base member 50 facing the cover member 60 recessed to form the recessed portion 51. The recessed portion 51 is a portion that forms the accommodation space 11 when the cover member 60 is mounted on the base member 50. The support portion 52 has a function of supporting the thermal element 40. The support portion 52 is provided in the recessed portion 51 near the center of the base member 50 in the width direction, and protrudes from the bottom portion of the recessed portion 51 in a cylindrical shape. In this case, the thermal element 40 is supported only by the support portion 52, and is not subject to pressing force or application force from other components.

[0050] The base member 50 has five protrusions 531, 532, 533. Each protrusion 531, 532, 533 is formed by protruding from the surface 501, 502 of the base member 50. Four protrusions 531, 531, 532, 532 are respectively provided near the corners of the base member 50. The remaining protrusion 533 is provided on a straight line connecting two protrusions 531, 531 arranged in the width direction and at a middle position between the two protrusions 531, 531. In the case of this embodiment, the height dimension of the protrusions 531, 532 provided near the corners is substantially equal to the thickness dimension of the base member 50 excluding the protrusions 531, 532.

[0051] In a state before the base member 50 and the cover member 60 are joined, as shown in FIG. Figure 4 and Figure 5 As shown in FIG. 1 , each protrusion 531, 532, 533 is formed in a cylindrical rod shape. Figure 3 , Figure 8 and Fig. 9As shown, heat caulking portions 531a, 532a, 533a are formed at the top end of each protrusion 531, 532, 533. The heat caulking portions 531a, 532a, 533a are formed by heating and collapsing the portions of each protrusion 531, 532, 533 exposed to the outside of the cover member 60, so-called heat caulking. The outer diameter of the heat caulking portions 531a, 532a, 533a is larger than the inner diameter of the through hole portions 611, 612, 613 of the cover member 60.

[0052] The base member 50 and the cover member 60 are formed in a rectangular shape, for example, a rectangular shape, as a whole in a plan view. The heat caulking portions 531a and 532a are provided at least at the corners of the base member 50 and the cover member 60. In the present embodiment, a heat caulking portion 533a is further provided between the two heat caulking portions 531a.

[0053] like Figure 5 , Figure 7 and Fig. 9 As shown, two contact holes 54 are provided in the recessed portion 51. Fig. 9 As shown in the figures, the contact hole 54 is formed in a circular shape and penetrates the bottom of the recessed portion 51. The two contact holes 54 are arranged in the recessed portion 51 along the width direction of the base member 50. The two contact holes 54 are arranged in the length direction of the base member 50 close to the side opposite to the three protrusions 531, 532, 533 arranged along the width direction of the base member 50. The fixed contact 12 provided in the fixed member 20 is exposed from the contact hole 54 to the storage space 11.

[0054] like Figure 5 and Figure 7 As shown, the rear wall portion 55, the side wall portion 56, and the intermediate wall portion 57 have the function of defining the position of the thermal element 40 disposed in the recessed portion 51. The rear wall portion 55 and the side wall portion 56 constitute a part of the wall portion surrounding the recessed portion 51. The rear wall portion 55 is a wall portion on the side of the protrusions 531, 533 in the wall portion surrounding the recessed portion 51.

[0055] The rear wall portion 55 has a function of limiting the movement of the thermal element 40 toward the protrusions 531, 533 in the longitudinal direction of the base member 50. Figure 7 The rear wall portion 55 is in contact with one of the edges extending in the width direction of the base member 50 in the outer periphery of the thermal element 40, that is, the edge 42 on one side in the length direction of the base member 50. The rear wall portion 55 is provided over the entire area of ​​the edge 42 of the thermal element 40.

[0056] The side wall portion 56 has a function of limiting the movement of the thermal element 40 in the width direction of the base member 50. Two side wall portions 56 are provided on both sides of the width direction of the recessed portion 51. The side wall portions 56 are in contact with a portion of the edge portion 44 extending in the length direction of the base member 50 in the outer periphery of the thermal element 40, that is, the edge portion 44 located on both sides in the width direction. The two side wall portions 56 are provided over a portion of the edge portion 44 in the width direction of the thermal element 40. The two side wall portions 56 are provided on the side close to the rear wall portion 55 in the length direction of the base member 50.

[0057] The intermediate wall portion 57 has a function of limiting the movement of the thermal element 40 toward the protrusion 532 in the longitudinal direction of the base member 50. Figure 7 The middle wall portion 57 has the function of moving to the right side of the paper. The middle wall portion 57 is arranged in a manner of standing upright from the bottom of the recessed portion 51. The middle wall portion 57 is arranged in the center portion of the width direction of the base member 50 in the recessed portion 51. The middle wall portion 57 is arranged between the two contact hole portions 54 and extends along the length direction of the base member 50. The middle wall portion 57 contacts the remaining one side portion 43 among the sides extending along the width direction of the base member 50 in the outer periphery of the thermal element 40. In addition, the middle wall portion 57 also has the function of ensuring the insulation distance between the fixed contacts 12, 12 of different phases arranged in the two contact hole portions 54.

[0058] When the thermal element 40 is disposed inside the recessed portion 51, the position of the thermal element 40 in the longitudinal direction relative to the base member 50 is determined by contacting the rear wall portion 55 and the intermediate wall portion 57. The position of the thermal element 40 in the width direction relative to the base member 50 is determined by contacting the side wall portion 56. When the thermal element 40 is not deforming, the outer periphery of the thermal element 40 does not contact any part other than the rear wall portion 55, the side wall portion 56, and the intermediate wall portion 57.

[0059] The cover member 60 is made of an electrically insulating resin, and is attached to the base member 50 to form the accommodation space 11 between the cover member 60 and the base member 50. The cover member 60 blocks the recessed portion 51 of the base member 50, thereby forming the accommodation space 11 in the recessed portion 51. Similar to the base member 50, the cover member 60 can be made of, for example, polyphenylene sulfide (PPS) mixed with about 30% to 40% of glass fiber.

[0060] like Figure 5As shown in the figures, the cover member 60 has a plurality of, for example, five, through-hole portions 611, 612, 613. Each through-hole portion 611, 612, 613 is formed at a position corresponding to each protrusion portion 531, 532, 533. Each through-hole portion 611, 612, 613 is formed, for example, in a circular shape to penetrate the cover member 60. The inner diameter of each through-hole portion 611, 612, 613 is slightly larger than the outer diameter of the corresponding protrusion portion 531, 532, 533.

[0061] The base member 50 and the cover member 60 are joined to each other without using a member such as a fastening member such as a screw or an adhesive, that is, a member other than the base member 50 and the cover member 60. The base member 50 and the cover member 60 are joined to each other without ultrasonic welding. When the switch assembly 10 is assembled, the base member 50 and the cover member 60 are joined to each other as follows.

[0062] First, the thermodynamic element 40 is arranged in the support portion 52 in the recessed portion 51 of the base member 50. Next, the movable member 30 is arranged in the base member 50 in a state where the three protrusions 531 and 533 are inserted into the insertion hole portion 35 of the movable member 30. Next, the corresponding protrusions 531, 532, 533 are inserted into the through holes 611, 612, 612 of the cover member 60, and the cover member 60 and the base member 50 are assembled.

[0063] At this time, if Figure 4 As shown, the top end of each protrusion 531, 532, 533 protrudes from each through hole 611, 612, 612 to the outside of the cover member 60. In addition, the portion of each protrusion 531, 532, 533 that protrudes to the outside of the cover member 60 is subjected to heat riveting. Through this heat riveting, the top end of each protrusion 531, 532, 533 is collapsed in a softened state to form heat riveted portions 531a, 532a, 533a. Each heat riveted portion 531a, 532a, 533a is locked in each through hole 611, 612, 613, thereby fixing the base member 50 and the cover member 60 to each other. This heat riveting is different from ultrasonic welding and the like, and high-frequency vibration is not used. Therefore, the vibration during ultrasonic welding, which is the cause of the generation of wear powder, is not applied to the base member 50 and the cover member 60, and the generation of wear powder in the storage space 11 can be suppressed.

[0064] The clip 70 is attached to the long side portions of the base member 50 and the cover member 60. The clip 70 clamps and holds the base member 50 and the cover member 60 from the outside of the base member 50 and the cover member 60. The clip 70 is formed by bending a metal plate such as a spring plate. The clip 70 applies a force in a direction in which the base member 50 and the cover member 60 approach each other, thereby preventing the base member 50 and the cover member 60 from being separated from each other.

[0065] like Figure 6 As shown, the clip 70 is provided near the center of the base member 50 and the cover member 60 in the longitudinal direction when the switch assembly 10 is viewed from above. The clip 70 is located between the protrusions 531, 533 and the protrusion 532 in the longitudinal direction of the switch assembly 10.

[0066] like Figure 5 As shown, the base member 50 has a base side receiving portion 58. The base side receiving portion 58 is a portion formed by recessing the side portion of the base member 50 by about the thickness of the clip 70. The cover member 60 has a cover side receiving portion 63. The cover side receiving portion 63 is a portion formed by recessing the side portion of the cover member 60 by about the thickness of the clip 70. When the base member 50 and the cover member 60 are combined, the base side receiving portion 58 and the cover side receiving portion 63 are substantially flush with each other. Furthermore, the clip 70 is embedded in the base side receiving portion 58 and the cover side receiving portion 63.

[0067] like Figure 8 to Figure 10 As shown, the abutment member 80 is embedded in the cover member 60 by insert molding. The abutment member 80 is arranged on the side opposite to the thermal element 40 relative to the movable member 30. The abutment member 80 has the function of dissipating the heat generated by the movable contact 13 and the movable member 30 when the switch assembly 10 is opened. The abutment member 80 can be composed of a metal plate with high thermal conductivity such as a stainless steel plate, a copper plate, etc.

[0068] The abutting member 80 has a contact portion 81. The contact portion 81 is provided at a position overlapping with the movable contact 13 in a plan view, and is exposed in the accommodating space 11. When the movable member 30 is deformed in a direction in which the movable contact 13 is separated from the fixed contact 12, the movable member 30 contacts the contact portion 81 of the abutting member 80. At this time, the heat generated by the movable contact 13 and the movable member 30 is dissipated to the cover member 60 via the abutting member 80.

[0069] like Fig.12 and Fig.13 As shown, the power line 91 is electrically and physically connected to the connection parts 21 and 31 of the switch assembly 10 by welding or the like. Figure 1 , Fig.12 and Fig.13 As shown, the thermal protector 1 is formed by inserting the first housing 3 into the second housing 2, and then inserting the switch assembly 10 into the first housing 3. The second housing 2 can be made of metal such as steel plate, stainless steel, copper, etc., and is formed into a box shape having a second opening 2a on one face of a cube. In order to improve mechanical strength and thermal conductivity, the second housing 2 can also be a housing that has been subjected to, for example, plating processing. In addition, the second housing 2 can also be made of a high-strength resin member such as so-called engineering plastics.

[0070] The first housing 3 is configured in a box shape having a first opening 3a on one face of a cube. The first housing 3 is formed of an electrically insulating resin and contains the switch assembly 10 therein. The first housing 3 can be formed of, for example, polyethylene terephthalate (PBT) mixed with about 30% to 40% of glass fiber.

[0071] The thermal protector 1 can be assembled, for example, in the following manner. First, the switch assembly 10 with the power lines 91 connected to the connection portions 21 and 31 is inserted into the first housing 3. Next, the first housing 3 housing the switch assembly 10 is inserted into the second housing 2. Thus, the thermal protector 1 is assembled.

[0072] like Figures 12 to 15 As shown, the thermal protector 1 further includes an insulating member 4, a first filler 5, and a second filler 6. The insulating member 4 is made of a resin material having electrical insulation. The insulating member 4 is inserted between adjacent connecting portions 21, 31, restricts the movement of the power lines 91 connected to the connecting portions 21, 31, and ensures insulation between the power lines 91.

[0073] The insulating member 4 can be made of, for example, the same material as the first housing 3, for example, polyethylene terephthalate (PBT) mixed with about 30% to 40% of glass fiber. The insulating member 4 integrally includes two isolating portions 4a and a connecting portion 4b. The two isolating portions 4a are arranged in parallel in a manner that the plate-like portions extending along the length direction of the switch assembly 10 face each other. The isolating portion 4a is arranged between the fixed portion side connecting portion 21 and the movable portion side connecting portion 31.

[0074] The connection portion 4b connects the two separators 4a. The connection portion 4b is formed in a plate shape having a surface perpendicular to the separator 4a. The connection portion 4b is arranged on one side in the thickness direction of the switch assembly 10, in this case, close to the base member 50 side.

[0075] like Figure 6 As shown, the switch assembly 10 further has two inserted portions 14. The inserted portions 14 are provided corresponding to the isolation portions 4a, and are formed by recessing the base member 50 and the cover member 60. When the insulating member 4 is mounted on the switch assembly 10, the top end portion of the isolation portion 4a enters the inserted portion 14. Thus, the mounting position of the insulating member 4 relative to the switch assembly 10 is specified.

[0076] The end portions of the insulating member 4 in the length direction, which are located on the outside, are not covered by the first filling material 5, but are exposed from the first filling material 5 and the first housing 3. When viewed along the thickness direction of the switch assembly 10, the end portions of the insulating member 4 in the length direction, which are located on the outside, are formed asymmetrically. The insulating member 4 has an asymmetric portion 4c. The asymmetric portion 4c can be formed by, for example, a cutout portion in which an outer corner of the isolating portion 4a is cut off. When an operator or an assembling device operates the switch assembly 10, the front and back sides of the switch assembly 10 can be identified by confirming the position of the asymmetric portion 4c of the insulating member 4.

[0077] like Fig.12 and Fig.13 As shown by the dashed section line of , the first filling material 5 is filled between the switch assembly 10 and the first housing 3. The first filling material 5 is a member having electrical insulation, and a thermosetting resin such as an epoxy adhesive can be used. After the switch assembly 10 and the insulating member 4 are inserted into the first housing 3, the first filling material 5 is filled into the first housing 3 from the first opening 3a of the first housing 3.

[0078] exist Fig.12 and Fig.13 In the figure, the second filling material 6 is represented by a dashed section line in a direction orthogonal to the section line of the first filling material 5. The second filling material 6 is located in the second housing 2 and is filled in the portion near the second opening 2a of the second housing 2 and in contact with the first filling material 5. The second filling material 6 is a member having electrical insulation, and, like the first filling material 5, a thermosetting resin such as an epoxy adhesive can be used. After the first housing 3 accommodating the switch assembly 10 and the insulating member 4 is inserted into the second housing 2, the second filling material 6 is filled into the second housing 2 from the second opening 2a of the second housing 2. The second filling material 6 is filled into the second housing 2 from the second opening 2a to block the second opening 2a, and the first housing 3 is fixed in the second housing 2. In addition, it is also possible to have a structure in which, for example, the gap between the first housing 3 and the second housing 2 is enlarged and the second filling material 6 is filled in the gap.

[0079] In addition, if Figures 2 to 4 , Fig.12 as well as Fig.15 As shown, the switch assembly 10 has a step portion 15. The step portion 15 is a step-shaped portion provided around the first opening portion 3a side of the first housing 3 in the switch assembly 10, and the step portion 15 contacted by the first filling material 5 is provided over the base member 50 and the cover member 60. Fig.15 As shown, the step portion 15 has a function of suppressing the progress of cracks V of the first filling material 5 or peeling of the bonding surface generated from the first opening portion 3a side. Fig.15As shown, for example, a crack V of the first filling material 5 generated from the first opening 3 a side encounters the step 15 and stops its progress.

[0080] The thermal protector 1 of this embodiment has a base member 50, a cover member 60, a fixed contact 12, a movable contact 13, a fixed member 20, a movable member 30, and a thermal element 40. The base member 50 is made of a resin having electrical insulation and thermoplasticity. The cover member 60 is made of a resin having electrical insulation, is mounted on the base member 50, and forms a receiving space 11 between the base member 50 and the cover member 60. The fixed contact 12 and the movable contact 13 are arranged in the receiving space 11. The fixed member 20 is provided with the fixed contact 12 and is fixed to the base member 50. The movable member 30 is provided with a movable contact, and is configured to be deformable in the receiving space 11, and a force in a direction of contacting the fixed contact 12 is applied to the movable contact 13. The thermal element 40 is accommodated in the receiving space 11, and deforms by being heated, thereby causing a force in a direction of moving the movable contact 13 away from the fixed contact 12 to act on the movable member 30.

[0081] The base member 50 has protrusions 531, 532, 533. The protrusions 531, 532, 533 are provided on the base member 50 and protrude from the surfaces 501, 502 of the base member 50. The cover member 60 has through-holes 611, 612, 613. The through-holes 611, 612, 613 are formed at positions corresponding to the protrusions 531, 532, 533 and penetrate the cover member 60. The protrusions 531, 532, 533 protrude to the outside of the cover member 60 through the through-holes 611, 612, 613, and the heat rivet portions 531a, 532a, 533a that are heat rivet are formed on the protruding portions, so that the base member 50 and the cover member 60 are fixed to each other.

[0082] Thus, the base member 50 and the cover member 60 can be joined to each other without using ultrasonic welding. Therefore, vibration during ultrasonic welding, which causes the generation of wear powder, is not applied to the base member 50 and the cover member 60, thereby suppressing the generation of wear powder in the accommodation space 11. In addition, the wear powder generated in the accommodation space 11 is suppressed from entering between the contacts 12 and 13, so that the occurrence of poor resistance, poor conduction, etc. caused by the wear powder can be reduced, and as a result, the reliability of the thermal protector 1 can be improved.

[0083] Therefore, the thermal protector 1 further includes a clip 70. The clip 70 is mounted on the long side portions of the base member 50 and the cover member 60, and clamps and holds the base member 50 and the cover member 60 from the outside of the base member 50 and the cover member 60. Thus, even when the base member 50 and the cover member 60 are joined by partial heat caulking, the base member 50 and the cover member 60 can be more reliably made to stick together. Thus, it is possible to prevent a gap from being generated between the base member 50 and the cover member 60, thereby preventing foreign matter, the first filling material 5, etc. from intruding into the accommodation space 11 through the gap. As a result, the reliability of the thermal protector 1 can be further improved.

[0084] The movable member 30 has two or more insertion holes 35. In the present embodiment, the movable member 30 has three insertion holes 35. The insertion holes 35 are located in the portion sandwiched between the base member 50 and the cover member 60, that is, the clamped portion 32, and are formed to penetrate in the thickness direction of the movable member 30. Each of the protrusions 531, 532, 533 is inserted into the corresponding insertion hole 35.

[0085] Thus, the movable member 30 can be assembled to the switch assembly 10 without fixing the movable member 30 to the base member 50 and the cover member 60. That is, according to this structure, the movable member 30 can be fixed between the base member 50 and the cover member 60 in the same process as the process of joining the base member 50 and the cover member 60. Therefore, the assembly process of the switch assembly 10 can be simplified.

[0086] The movable member 30 is sandwiched between the base member 50 and the cover member 60 and supported in a cantilever beam shape. Fig.11 As shown, the portion of the cover member 60 that contacts the sandwiched portion 32 of the movable member 30 extends further than the base member 50 by a portion of the region A toward the distal end side of the movable member 30 , that is, toward the arm portion 34 .

[0087] Therefore, even when the boundary portion 62 between the portion in contact with the movable component 30 and the portion not in contact with the movable component 30 in the cover member 60 is square in shape, it is possible to suppress a large shear force from acting from the rear edge 42 of the thermal element 40 on the portion in contact with the boundary portion 62 of the movable component 30, resulting in the suppression of deformation and breakage of the movable component 30.

[0088] The thermal protector 1 further includes an abutment member 80. The abutment member 80 is made of metal and is provided on the cover member 60 by insert molding. When the movable member 30 is deformed in a direction in which the movable contact 13 is separated from the fixed contact 12, the abutment member 80 contacts the movable member 30. When the fixed contact 12 and the movable contact 13 are opened, the heat of the movable contact 13 can be released to the cover member 60 via the abutment member 80. Therefore, it is possible to suppress the inconvenience caused by excessive heat being applied to the movable member 30, such as a change in the spring constant of the movable member 30.

[0089] The thermal element 40 is not fixedly disposed in the housing space 11. Thus, the process of fixing the thermal element 40 to the base member 50 and the cover member 60 can be omitted, and thus the assembly process of the switch assembly 10 can be simplified.

[0090] The thermal protector 1 further includes a switch assembly 10, a first housing 3, and a first filling material 5. The switch assembly 10 is formed by assembling a base member 50, a cover member 60, a fixed contact 12, a movable contact 13, a fixed member 20, a movable member 30, and a thermal element 40. The first housing 3 is configured to accommodate the switch assembly 10 and has a first opening 3a into which the switch assembly 10 is inserted. The first filling material 5 is filled into the first housing 3 and around the switch assembly 10 from the first opening 3a of the first housing 3. In addition, the switch assembly 10 has a step 15 at a portion contacted by the first filling material 5.

[0091] Therefore, if Fig.15 As shown, for example, a crack V of the first filling material 5 generated from the first opening 3a side stops advancing when encountering the step 15. Therefore, the step 15 can suppress the progress of the crack V of the first filling material 5 generated from the first opening 3a side or the peeling of the bonding surface. As a result, it is possible to suppress the crack V from expanding and causing a decrease in insulation performance, and as a result, the reliability of the thermal protector 1 can be improved.

[0092] The thermal protector 1 further includes a second housing 2 and a second filling material 6. The second housing 2 is configured to accommodate the first housing 3 and has a second opening 2a into which the first housing 3 is inserted. The first housing 3 accommodates the switch assembly 10. The second filling material 6 is filled into the second housing 2 from the second opening 2a to block the second opening 2a and fix the first housing 3 in the second housing 2.

[0093] Thus, by covering the outside of the first shell 3 with the second shell 2, even when an external force is applied to the thermal protector 1, it is possible to prevent the external force from being directly applied to the first shell 3. In addition, by fixing the first shell 3 in the second shell 2 with the second filling material 6, even when an external force is applied to the thermal protector 1, it is possible to prevent the first shell 3 from moving greatly in the second shell 2 and violently colliding with each other. Therefore, according to this structure, by suppressing the deformation of the first shell 3 caused by the application of an external force to the thermal protector 1, it is possible to suppress the change in the characteristics of the thermal protector due to the deformation of the accommodation space 11, and as a result, the reliability of the thermal protector 1 can be further improved.

[0094] The above-described embodiment is provided as an example and is not intended to limit the scope of the invention. The new embodiment can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. The present embodiment and its variations are included in the scope and spirit of the invention, and are included in the invention described in the claims and their equivalents.

Claims

1. A thermal protector, comprising: a base member composed of a resin having electrical insulation and thermoplasticity; a cover member, which is made of an electrically insulating resin and is mounted on the base member to form a housing space between the cover member and the base member; Fixed contacts and movable contacts, which are arranged in the receiving space; a fixed member provided with the fixed contact and fixed to the base member; a movable member provided with the movable contact, configured to be deformable in the accommodation space and to cause a force in a direction of contact with the fixed contact to act on the movable contact; as well as a thermal element, which is accommodated in the accommodation space and deforms by being heated, thereby causing a force in a direction in which the movable contact moves away from the fixed contact to act on the movable member; The base member has a protrusion provided on the base member and protruding from the surface of the base member, The cover member has a through hole portion formed at a position corresponding to the protrusion and penetrating the cover member. The protruding portion passes through the through hole portion and protrudes to the outside of the cover member, and a heat caulking portion that is heat caulked is formed at the protruding portion, so that the base member and the cover member are fixed to each other.

2. The thermal protector according to claim 1, further comprising: A clip is mounted on the long side portions of the base member and the cover member to sandwich and hold the base member and the cover member from outside the base member and the cover member.

3. The thermal protector according to claim 1, wherein: The movable member has two or more insertion holes formed through the movable member in a thickness direction at a portion sandwiched by the base member and the cover member. The protrusion is inserted into the insertion hole.

4. The thermal protector according to claim 1, wherein: The movable member is sandwiched between the base member and the cover member and supported in a cantilever beam shape. A portion of the cover member that contacts the movable member extends further toward a tip end side of the movable member than the base member.

5. The thermal protector according to claim 1, further comprising: The metal abutment member is provided on the cover member by insert molding and is contacted by the movable member when the movable member is deformed in a direction in which the movable contact is separated from the fixed contact.

6. The thermal protector according to claim 1, wherein: The thermal element is volatilely disposed in the accommodation space.

7. The thermal protector according to any one of claims 1 to 6, further comprising: A switch assembly, which is formed by assembling the base member, the cover member, the fixed contact, the movable contact, the fixed member, the movable member, and the thermal element; A first housing configured to accommodate the switch assembly and having a first opening into which the switch assembly is inserted; as well as a first filling material filled into the first housing and around the switch assembly from the first opening; The switch component has a stepped portion at a portion contacted by the first filling material.

8. The thermal protector according to claim 7, further comprising: a second housing configured to accommodate the first housing and having a second opening into which the first housing is inserted, wherein the first housing accommodates the switch assembly; and The second filling material is filled into the second housing through the second opening to block the second opening and fix the first housing in the second housing.

Images