JP5969414B2 - Temperature sensor - Google Patents

Description

  The present invention relates to a temperature sensor including a thermal element whose resistance value changes according to temperature.

  2. Description of the Related Art Conventionally, a temperature sensor that detects the temperature of exhaust gas flowing through an exhaust gas passage such as an exhaust pipe of an automobile by a thermal element (for example, a thermistor element) is known. For example, the temperature sensor described in Patent Document 1 includes a thermistor element in the tip of a metal tube. A pair of jumet wires that are connected to the thermistor element and extract the output are connected to a pair of conductive wires inserted through the metal tube by resistance welding. The conductive wire is connected to a pair of lead wires responsible for electrical connection with an external device at the rear end of the metal tube. The metal tube has an insulating tube having two holes penetrating in the axial direction inside. The pair of conductive wires are inserted through the respective holes to ensure insulation between the metal tube and the conductive wires.

  In general, a dumet wire obtained by coating a nickel wire with copper has a lower tensile strength than a conductive wire using a stainless alloy or the like. In order to prevent breakage of the dumet wire, the insulating tube fixes the conductive wire in the hole by a fixing member such as cement filled in the hole. In recent years, there has been a problem that it is difficult to fill the gap between the hole and the conductive wire, which is thinner than before, with the fixing member due to the reduction in the diameter of the insulating tube accompanying the performance improvement of the temperature sensor. The insulating tube described in Patent Document 1 forms a notch that exposes two holes on an outer surface corresponding to a portion where a connection part between a jumet wire and a conductive wire is disposed in the hole. The fixing member is filled from the notch into the hole, and the insulating tube can reliably fix the pair of conductive wires in each hole.

JP 2012-247243 A

  However, since the insulating tube of Patent Document 1 is sized so that the notch portion exposes the two holes, the strength at the time of receiving an external force in the direction perpendicular to the axis at the notch portion formation site is other than that. There was a possibility that it would be lower than the region.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a temperature sensor that can easily dispose the fixing member in the hole and can secure the strength of the insulating member. .

  According to the 1st aspect of this invention, it has a heat sensitive part from which resistance value changes according to temperature, and a pair of 1st conductive wire which extends along an extending | stretching direction and one end side is each connected to the said temperature sensitive part. A thermal element and an end extending along the extending direction, one end side being connected to the other end of the first conductive line, and the other end side being respectively directed to the opposite side to the one end side of the first conductive line An insulating insulating member having a second conductive line and a pair of holes extending in the extending direction and penetrating through the second conductive line in the extending direction, wherein the other end of the first conductive line and the second conductive line A temperature sensor comprising: an insulating member that disposes a joining portion that joins one end portion of the conductive wire in each of the hole portions, and an outer periphery of the insulating member corresponding to an arrangement position of the joining portion in at least the hole portion Groove shape extending along the extending direction on the surface A pair of slits that connect the inside and the outside of each of the pair of holes, and at least a portion of the holes connected to the slit, and at least the joint is the hole A fixing member that fixes the inner peripheral surface of the slit portion, wherein the opening width of the slit portion is smaller than the hole diameter of the hole portion, and the hole portion includes a dimension larger than the opening width of the slit portion. A temperature sensor is provided in which the second conductive wire having a cross-sectional shape is disposed.

  Since the slit portion is provided with a fixing member in the hole portion and fixes the joint portion to the inner peripheral surface of the hole portion, the slit portion opens at the position of the outer peripheral surface corresponding to the joint portion. Therefore, in the insulating member, it is possible to ensure a large thickness of a portion that supports a portion lacking as the slit portion. Therefore, the insulating member can ensure a sufficient strength particularly against bending in the radial direction. Further, the second conductive line has a size that includes a dimension larger than the opening width of the slit portion when viewed in a cross-sectional shape. Therefore, when the second conductive wire is inserted into the hole at the time of assembling the temperature sensor, the second conductive wire does not come out through the slit portion, and the assembly is easy. Further, by providing the slit portion, it is possible to look into the slit portion and confirm the fixing state of the joint portion by the fixing member when or after the fixing member is provided at the position where the joint portion is disposed.

  In the first aspect, the insulating member has, in the extending direction, a first end portion that is an end portion on a side where one end side of the first conductive wire is disposed when the joint portion is disposed in the hole portion. The opening portion of the slit portion may be formed on the outer peripheral surface of the joint portion. Since the slit part opened to the position of the outer peripheral surface corresponding to the position which arrange | positions a junction part in a hole part does not open to the whole insulating member, an insulating member can ensure intensity | strength. Since the slit portion is formed starting from the first end portion of the insulating member, positioning at the slit portion formation can be omitted at least on the first end portion side, and labor can be reduced.

  1st aspect WHEREIN: The said insulating member is near the 2nd end part which is an edge part on the opposite side to the said 1st end part from the said 1st end part in the said extending | stretching direction from the arrangement position of the said junction part. The opening portion of the slit portion may be formed on the outer peripheral surface extending to the position. Since the slit part is formed in the portion from the first end side to the position near the second end part beyond the arrangement position of the joint part, when or after providing the fixing member at the joint position, Not only from the first end side, but also from the second end side, the fixed state of the joint by the fixing member can be confirmed.

  In the first aspect, the insulating member has, in the extending direction, a first end portion that is an end portion on a side where one end side of the first conductive wire is disposed when the joint portion is disposed in the hole portion. The opening portion of the slit portion may be formed on the outer peripheral surface extending to the second end portion that is the end portion on the opposite side to the first end portion. By providing the slit portion over the entire length of the insulating member, positioning in forming the slit portion on both the first end portion side and the second end portion side can be omitted when manufacturing the insulating member, and labor can be reduced. Moreover, it can use without considering the directivity in the extending | stretching direction of an insulating member by forming the slit part in full length. That is, when manufacturing the temperature sensor, there is no need to specify the direction of the insulating member, and the second conductive wire may be inserted from the first end side or the second end side of the insulating member. The lead time in assembling the temperature sensor can be shortened.

  1st aspect WHEREIN: In the cross section of the said insulating member orthogonal to the said extending | stretching direction and including the formation position of the said slit part, the said pair of slit part is the inner peripheral surface of the said pair of hole part, and the said outer periphery of the said insulating member You may form in the site | part with the shortest distance with a surface, respectively. The formation position of the slit portion is a portion where the depth of the groove constituting the slit portion is the shallowest. Therefore, when the fixing member is provided in the slit portion, it is easy to reach the hole portion when the fixing member is injected from the opening. For this reason, it is possible to reduce the possibility that the injection of the fixing member stays in the groove or does not reach the joint even if it reaches. Moreover, the usage-amount of a fixing member can be reduced and manufacturing cost can be reduced.

2 is a longitudinal sectional view of a temperature sensor 100. FIG. 3 is a perspective view of an insulating tube 4. FIG. It is sectional drawing of the insulating tube 4 seen from the arrow direction in the dashed-dotted line AA of FIG. 3 is a perspective view of an insulating tube 104. FIG. It is sectional drawing of the insulating tube 104 seen from the arrow direction in the dashed-dotted line BB of FIG.

  Embodiments of a temperature sensor embodying the present invention will be described below with reference to the drawings. The drawings to be referred to are used for explaining the technical features that can be adopted by the present invention, and the configuration of the apparatus described is not intended to be limited to that, but is merely an illustrative example.

  The configuration of the temperature sensor 100 will be described with reference to FIG. In the following description, the vertical direction in FIG. 1 is the vertical direction of the temperature sensor 100. The upper side of FIG. 1 is the rear end side of the temperature sensor 100, and the lower side is the front end side of the temperature sensor 100. In FIG. 1, an axis O indicated by a one-dot chain line is an axis of the temperature sensor 100.

  The temperature sensor 100 includes the thermistor element 2. The thermistor element 2 is an example of a thermal element capable of detecting temperature by changing a resistance value according to temperature. The temperature sensor 100 is attached to, for example, an exhaust pipe that discharges exhaust gas discharged from an engine of a car (not shown) to the outside of the car. The thermistor element 2 is disposed in the exhaust pipe and detects the temperature of the exhaust gas.

  As shown in FIG. 1, the temperature sensor 100 includes a metal tube 1, a thermistor element 2, an element holder 3, an insulating tube 4, a metal shell 5, a grommet 7, and the like. The metal tube 1 is a metal tube that extends along the direction of the axis O and has a closed end portion 11 and is formed using, for example, a stainless alloy. The metal tube 1 includes a small-diameter portion 13, a first medium-diameter portion 14, a second relay portion 15, and a large-diameter portion 16 whose outer diameter sequentially increases from the front end portion 11 side toward the rear end portion 12 side.

  The metal tube 1 accommodates a thermistor element 2, an element holder 3, an insulating tube 4 and a grommet 7 inside. The thermistor element 2 is arranged inside the metal tube 1, that is, in the small diameter portion 13. The thermistor element 2 includes a thermistor sintered body 21, a pair of jumet wires 22 and a sealing body 23. The thermistor sintered body 21 is a chip-like element whose resistance value changes with temperature. The dumet wire 22 is a conductive wire obtained by coating a nickel steel wire with copper. The tips of the dumet wires 22 are connected to electrodes formed on the front and back surfaces of the thermistor sintered body 21 facing each other. The jumet lines 22 extend rearward in the direction of the axis O and are arranged side by side. The sealing body 23 is glass, and seals the tip end portion of the jumet wire 22 and the thermistor sintered body 21 inside. The distal end of the sealing body 23 contacts the inner surface of the distal end portion 11 of the metal tube 1.

  The element holding body 3 is disposed at a position across the step portion between the small diameter portion 13 and the first medium diameter portion 14 of the metal tube 1 on the rear end side of the thermistor element 2. The element holder 3 is a cylindrical member in which a pair of holes 31 are formed in an insulating ceramic body. The element holding body 3 positions the thermistor element 2 by inserting the jumet wire 22 into each hole 31 and bringing the tip into contact with the sealing body 23.

  The insulating tube 4 is a cylindrical member in which a pair of holes 43 penetrating in the axis O direction are formed in an insulator made of ceramic such as alumina extending in the axis O direction. The insulating tube 4 is disposed on the rear end side of the element holder 3 and extends from the distal end side of the first medium diameter portion 14 of the metal tube 1 to the vicinity of the center of the large diameter portion 16. Details of the insulating tube 4 will be described later.

  The insulating tube 4 has a pair of conductive wires 8 disposed in the two holes 43. The conductive wire 8 is two metal wires extending along the axis O, and is formed in a circular cross section using, for example, a stainless alloy such as SUS304. The conductive wire 8 has a distal end portion 81 disposed at the distal end portion 41 of the insulating tube 4 in the hole portion 43, and extends backward in the hole portion 43 along the axis O toward the rear end side. The tip 81 of the conductive wire 8 is processed into a flat plate shape. The rear end portion 82 of the conductive wire 8 is exposed from the rear end portion 42 of the insulating tube 4. The leading end portion 81 of the conductive wire 8 is joined to the rear end portion 24 of the jumet wire 22 of the thermistor element 2 by resistance welding to form a joining portion 80. The joint portions 80 are respectively disposed in the hole portions 43 at the distal end portion 41 of the insulating tube 4. The outer diameter R1 of the conductive wire 8 is larger than the outer diameter P of the dumet wire 22 (see FIG. 3).

  The grommet 7 is a rubber member having a pair of holes 73 extending in the axis O direction and penetrating in the axis O direction. The grommet 7 is fitted into the rear end portion 12 of the metal tube 1 and is disposed on the large diameter portion 16. A part of the front end portion of the grommet 7 contacts the rear end 50 of the insulating tube 4 and covers the periphery of the rear end portion 42. The metal tube 1 includes a caulking portion 17 whose outer diameter is deformed to be small by caulking in the large diameter portion 16. The metal tube 1 presses the grommet 7 inward in the radial direction by the crimping portion 17, and holds the grommet 7 in the large diameter portion 16. The grommet 7 is elastically deformed by the formation of the caulking portion 17 and extends in the direction of the axis O, and presses the insulating tube 4 toward the tip side in the direction of the axis O. The thermistor element 2 is pressed toward the inner surface of the tip 11 of the metal tube 1 through the insulating tube 4 and the element holder 3. The metal tube 1 is fixed by sandwiching the thermistor element 2, the element holding body 3 and the insulating tube 4 between the inner surface of the distal end portion 11 and the grommet 7.

  The rear end portion 82 of the conductive wire 8 is joined to a connection terminal 96 provided at the front end portion of the pair of lead wires 95 by resistance welding. The lead wire 95 passes through the hole 73 of the grommet 7 and is drawn out of the temperature sensor 100. The grommet 7 seals the gap between the hole 73 and the lead wire 95 by forming the above-described caulking portion 17 to ensure watertightness.

  In the metal tube 1, a cylindrical metal shell 5 having a cylindrical hole 55 penetrating in the direction of the axis O is fitted on the outer periphery of the second medium diameter portion 15. The metal shell 5 is a metal fitting for attaching the temperature sensor 100 to an exhaust pipe (not shown). The cylindrical hole 55 has a stepped portion 56 on the rear end side where the stepped portion 18 between the second medium diameter portion 15 and the large diameter portion 16 of the metal tube 1 is locked. The metal shell 5 is integrated with the metal tube 1 by brazing the inner peripheral surface of the cylindrical hole 55 and the outer peripheral surface of the second medium diameter portion 15 with the metal tube 1 positioned on the stepped portion 56. Join.

  The metal shell 5 includes an attachment portion 52 and a tool engagement portion 54. The mounting portion 52 has a male screw 53 on the outer peripheral surface, and fixes the metal shell 5 to a mounting hole (screw hole) provided in the exhaust pipe by a screwing method. The tool engaging portion 54 protrudes in a bowl shape toward the radially outer side on the rear end side of the mounting portion 52. The tool engaging portion 54 has, for example, a hexagonal shape in which a cross section perpendicular to the axis O can engage with a tool used when the metal shell 5 is attached to the exhaust pipe. In the metal shell 5, a gasket 51 formed by bending an annular plate material is attached to a screw neck between the attachment portion 52 and the tool engagement portion 54. The gasket 51 is crushed and deformed when the temperature sensor 100 is screwed into the mounting hole (screw hole) of the exhaust pipe, and seals the gap between the opening peripheral portion of the mounting hole and the tip end surface 57 of the tool engaging portion 54. Stop.

  Next, the insulating tube 4 will be described with reference to FIGS. As described above, the insulating tube 4 is a cylindrical member in which a pair of holes 43 are formed in an insulating ceramic insulator. As shown in FIG. 3, the outer peripheral surface 46 of the insulating tube 4 and the inner peripheral surface 44 of the hole 43 have a substantially circular cross-sectional shape orthogonal to the axis O. The hole portions 43 are arranged side by side in the insulating tube 4, and a slit portion 45 that connects the inside of the hole portion 43 and the outside of the insulating tube 4 is formed in each. As shown in FIG. 2, the slit portion 45 has a narrow groove shape extending along the direction of the axis O and opens on the outer peripheral surface 46 of the distal end portion 41 of the insulating tube 4.

  As shown in FIG. 3, the slit portion 45 is formed at a position connecting the outer peripheral surface 46 and each hole portion 43 along the direction in which the two hole portions 43 are arranged in the cross section of the insulating tube 4. More specifically, the slit portion 45 is formed in the groove at a position including a virtual line L1 (indicated by a two-dot chain line) passing through the center positions C1 and C2 of the inner peripheral surface 44 of each hole portion 43. Yes. The formation position of the slit portion 45 is a position where the distance D between the inner peripheral surface 44 of the hole 43 and the outer peripheral surface 46 of the insulating tube 4 can be minimized in the cross section of the insulating tube 4. In other words, the formation position of the slit portion 45 is a position where the depth of the groove from the outside to the inside of the hole portion 43 can be minimized. Desirably, the center position in the width direction of the slit portion 45 in the cross section of the insulating tube 4 may be located on the virtual line L1.

  As shown in FIGS. 1 and 2, in the slit portion 45, the joint portion 80 between the jumet wire 22 and the conductive wire 8 is arranged in the hole portion 43 from the position of the tip 47 at the tip portion 41 of the insulating tube 4. It opens to the outer peripheral surface 46 over a certain position. That is, the joint 80 disposed in the hole 43 is visible from the outside of the insulating tube 4 through the slit 45. The slit portion 45 also opens on the outer peripheral surface 46 from the position where the joint portion 80 is disposed to a position closer to the rear end portion 42 than the position. That is, in the direction of the axis O, the tip 48 of the slit 45 is located at the tip 47 of the insulating tube 4, and the rear end 49 of the slit 45 is located behind the position where the joint 80 is disposed. In other words, the opening of the slit portion 45 is located on the outer peripheral surface 46 of the distal end portion 41 of the insulating tube 4 at a position closer to the rear end portion 42 across the arrangement position of the joint portion 80 from the position of the distal end 47 along the axis O direction. Is formed.

  As shown in FIG. 3, the opening width Q <b> 1 of the slit portion 45 is smaller than the hole diameter S of the hole portion 43. The outer diameter R1 of the conductive wire 8 is larger than the opening width Q1 of the slit portion 45. Further, the width W of the tip portion 81 processed into a flat plate shape in the conductive wire 8 is also larger than the opening width Q <b> 1 of the slit portion 45. That is, the conductive wire 8 having a cross-sectional shape including a dimension larger than the opening width Q1 of the slit portion 45 is disposed in the hole portion 43. Thus, the conductive wire 8 does not come out of the insulating tube 4 through the slit portion 45 in a state where the conductive wire 8 is inserted into the hole 43 of the insulating tube 4. In addition, it is possible to easily perform the operation of joining the dumet wire 22 of the thermistor element 2 with the conductive wire 8 inserted into the insulating tube 4.

  As shown in FIGS. 2 and 3, the insulating tube 4 is provided with a fixing member 9 in the hole 43. The fixing member 9 is, for example, cement mainly composed of alumina. In the manufacturing process of the temperature sensor 100, the operator injects the fixing member 9 into the hole 43 through the slit 45 using, for example, a syringe. The fixing member 9 fixes at least the joint 80 between the conductive wire 8 and the dumet wire 22 to the inner peripheral surface 44 of the hole 43. The operator visually confirms the inside of the hole portion 43 through the slit portion 45 from the front end side in the axis O direction, thereby confirming the fixing state of the joint portion 80 to the inner peripheral surface 44 of the hole portion 43 by the fixing member 9. be able to. Further, the rear end 49 of the slit portion 45 is located behind the position where the joint portion 80 is disposed in the axis O direction. Therefore, the operator visually confirms the inside of the hole 43 from the rear end side in the direction of the axis O through the slit 45 and confirms the fixed state of the joint 80 to the inner peripheral surface 44 of the hole 43 by the fixing member 9. You can also

  The arrangement of the fixing member 9 in the hole 43 is not limited to injection by a syringe or the like. For example, the distal end portion 41 of the insulating tube 4 is immersed in the liquid fixing member 9 to penetrate into the slit portion 45, the fixing member 9 is disposed in the hole portion 43, and the joint portion 80 is fixed to the inner peripheral surface 44. Also good. Alternatively, after thickly applying the highly viscous fixing member 9 to the outer peripheral surface 46 of the distal end portion 41 of the insulating tube 4, one side of the hole portion 43 is closed and vacuuming is performed from the other side, so that the fixing member 9 is placed inside the hole portion 43. The joint 80 may be fixed to the inner peripheral surface 44.

  The temperature sensor 100 having such a configuration is generally manufactured as follows. First, the insulating tube 4 in which the slit portion 45 is formed is prepared.

  In the connection process of the conductive wires 8, a pair of conductive wires 8 whose tip portions 81 are processed into a flat plate shape are respectively inserted into the holes 43 from the rear end portion 42 side of the insulating tube 4, and from the tips 47 to the outside of the holes 43. Exposed. Since the outer diameter R1 of the conductive wire 8 is larger than the opening width Q1 of the slit portion 45 and the width W of the tip portion 81 processed into a flat plate shape is also larger than the opening width Q1 of the slit portion 45, The line 8 is positioned inside the hole 43 without coming out to the outside through the groove of the slit 45. The dumet wire 22 of the thermistor element 2 formed by another process is inserted into the pair of holes 31 of the element holding body 3. The rear end portion 24 of the dumet wire 22 and the front end portion 81 of the conductive wire 8 are connected by known resistance welding to form a joint portion 80.

  In the arrangement step of the joint portion 80, the conductive wire 8 is pulled toward the rear end portion 42 side of the insulating tube 4, and the joint portion 80 is drawn into the hole portion 43. The rear end of the element holder 3 abuts on the front end 47 of the insulating tube 4. The joint 80 is located within the hole 43 within the range where the slit 45 is formed. That is, the joint 80 is located between the front end 48 and the rear end 49 of the slit portion 45 in the direction of the axis O (more specifically, a position closer to the rear end 49).

  In the fixing process of the joint 80, the fixing member 9 (cement) is injected into the hole 43 of the insulating tube 4 through the slit 45 using a syringe or the like. The injection position of the fixing member 9 includes at least the arrangement position of the joint 80. It is confirmed by visual observation whether the fixing member 9 is reliably positioned between the inner peripheral surface 44 of the hole 43 and the joint 80. The fixing member 9 is dried, and the joint 80 is fixed to the inner peripheral surface 44 of the hole 43 by the fixing member 9. Through the above steps, an assembly in which the thermistor element 2 and the conductive wire 8 are held in the insulating tube 4 is obtained.

  In the assembly process of the temperature sensor 100, the rear end portion 82 of the conductive wire 8 of the assembly is resistance-welded to the connection terminal 96 of the lead wire 95. The assembly is inserted into the metal tube 1 and the thermistor element 2 is placed in the small diameter portion 13 of the metal tube 1. The lead wire 95 is inserted into the hole 73 of the grommet 7, and the grommet 7 is fitted into the large-diameter portion 16 of the metal tube 1, and a part of the tip is brought into contact with the rear end 50 of the insulating tube 4. Then, the outer periphery of the large diameter portion 16 is crimped inward to form a crimped portion 17, the grommet 7 is fixed to the large diameter portion 16, and the inside of the metal tube 1 is sealed.

  The metal tube 1 is inserted into the cylindrical hole 55 from the rear end side of the metal shell 5 produced in another process, and the step portion 18 of the metal tube 1 is locked to the step portion 56 of the metal shell 5 for positioning. The inner peripheral surface of the cylindrical hole 55 and the outer peripheral surface of the second medium diameter portion 15 are brazed, and the metal shell 5 and the metal tube 1 are joined together. The temperature sensor 100 is completed by attaching the gasket 51 to the threaded neck of the metal shell 5 and preventing it from coming off.

  As described above, the slit portion 45 is provided at the position of the outer peripheral surface 46 corresponding to the joint portion 80 because the fixing member 9 is provided in the hole portion 43 and the joint portion 80 is fixed to the inner peripheral surface 44 of the hole portion 43. The opening width Q1 is narrow because it is slit-shaped. Therefore, it is possible to secure a large thickness of a portion of the insulating tube 4 that supports a portion lacking as the slit portion 45. Therefore, the insulating tube 4 can ensure sufficient strength especially against bending in the radial direction. Further, the conductive wire 8 is formed to include a dimension larger than the opening width Q1 of the slit portion 45 when viewed in a cross-sectional shape including the front end portion 81. Therefore, when the conductive wire 8 is inserted into the hole 43 when the temperature sensor 100 is assembled, the conductive wire 8 does not come out through the slit 45 and the assembly is easy. Further, since the slit portion 45 is provided, when the fixing member 9 is provided at the position where the joint portion 80 is disposed or after the fixing member 9 is provided, the slit portion 45 is looked into and the fixing state of the joint portion 80 by the fixing member 9 is confirmed. It is also possible.

  Since the slit portion 45 opened to the position of the outer peripheral surface 46 corresponding to the position where the joint portion 80 is disposed in the hole portion 43 does not open to the entire insulating tube 4, the insulating tube 4 can ensure strength. Moreover, since the slit part 45 is formed with the front end 47 of the insulating tube 4 as a starting end, positioning at the formation of the slit part 45 can be omitted at least on the front end 47 side, and labor can be reduced. Furthermore, if the slit portion 45 is formed in a portion from the tip 47 side to the position near the second end portion beyond the position where the joint portion 80 is disposed, when the fixing member 9 is provided at the position where the joint portion 80 is disposed or After being provided, the fixed state of the joint 80 by the fixing member 9 can be confirmed not only by looking from the tip 47 side but also by looking from the second end side.

  Further, the slit 45 can have the smallest distance D between the inner peripheral surface 44 of the hole 43 and the outer peripheral surface 46 of the insulating tube 4 in the cross section of the insulating tube 4 (a cross section orthogonal to the axis O direction). Formed in position. That is, the formation position of the slit portion 45 is a portion where the depth of the groove constituting the slit portion 45 is the shallowest. Therefore, when the fixing member 9 is provided in the slit portion 45, the fixing member 9 can easily reach the hole portion 43 when the fixing member 9 is injected from the opening. For this reason, it is possible to reduce the possibility that the injection of the fixing member 9 stays in the groove or does not reach the joint 80 even if it reaches. Moreover, the usage-amount of the fixing member 9 can be reduced and manufacturing cost can be reduced.

  The present invention is not limited to the above embodiment, and various modifications may be made without departing from the scope of the present invention. For example, like the insulating tube 104 shown in FIG. 4, the slit portion 145 may be formed over the entire length of the insulating tube 104 in the axis O direction. In other words, the opening of the slit portion 145 may be formed on the outer peripheral surface 146 of the insulating tube 104 from the position of the front end 147 to the position of the rear end 150 along the axis O direction. The insulating tube 104 in which the slit portion 145 is formed over the entire length can be used without considering the directivity in the axis O direction. That is, in assembling the temperature sensor, the insulating tube 104 may be disposed in the metal tube 1 with the tip 147 in FIG. 4 facing the tip, or may be disposed toward the rear end. Since the work can be performed without specifying the direction of the insulating tube 104, the lead time in assembling the temperature sensor can be shortened. Further, in the manufacturing process of the insulating tube 104, when forming the slit portion 145, the position of the rear end 149 of the slit portion 145 is not positioned in the vicinity of the position where the joint portion 180 between the dumet wire 22 and the conductive wire 108 is arranged. It is good, so you can save time.

  As shown in FIGS. 4 and 5, the conductive wire 108 is not limited to a metal wire having a circular cross section, and may be a metal wire formed in a narrow plate shape. In this case, even if the thickness T of the conductive wire 108 is smaller than the opening width Q2 of the slit portion 145, the cross section of the conductive wire 108 when the joint portion 180 is disposed in the hole 143 of the insulating tube 104. The shape may include a dimension larger than the opening width Q2. Specifically, as shown in FIG. 5, in the cross-sectional shape of the conductive wire 108 when the bonding portion 180 is disposed in the hole 143, the length R <b> 2 in the direction orthogonal to the depth direction of the groove of the slit portion 145. However, what is necessary is just to be larger than the opening width Q2 of the slit part 145.

  More specifically, in a state where the joint portion 180 is disposed in the hole portion 143, a cross section of the insulating tube 104 that is orthogonal to the axis O and includes the conductive wire 108 is seen. In the cross section, an imaginary line L2 (indicated by a two-dot chain line) passing through the center position C3 of the opening of the slit portion 145 and the center position C2 of the inner peripheral surface 44 of the hole portion 143 on the outer peripheral surface 146 of the insulating tube 104. Consider a virtual line L3 (indicated by a two-dot chain line) orthogonal to the virtual line L2. The conductive line 108 and the opening of the slit portion 145 are projected onto the virtual line L3 along the virtual line L2. For convenience, it is assumed that the depth direction of the groove of the slit portion 145 is the same as the direction along the virtual line L2. At this time, the length of the projection range of the slit portion 145 projected onto the imaginary line L3, that is, the opening width Q2 of the slit portion 145 is the length of the projection range of the conductive line 108 projected onto the imaginary line L3, ie It is shorter than the length R2 in the cross-sectional shape of the conductive wire 108. With this configuration, even when the thickness T of the conductive wire 108 is smaller than the opening width Q <b> 2 of the slit portion 145, in the state where the conductive wire 108 is disposed in the hole portion 143, the conductive wire 108 causes the slit portion 145 to be disposed. Through the outside.

  The conductive wires 8 and 108 are not limited to a metal wire having a circular cross section as in the present embodiment or a narrow plate-like metal wire having a rectangular cross section as described above. That is, the conductive wires 8 and 108 have a cross-sectional shape that includes dimensions larger than the opening widths Q1 and Q2 of the slit portions 45 and 145 in a state where the conductive wires 8 and 108 are disposed in the hole portions 43 and 143, respectively. Good. For example, in the above embodiment, the tip portion 81 of the conductive wire 8 is processed into a flat plate shape, but the tip portion 81 is not processed, and is joined to the jumet wire 22 with a circular cross-section with resistance welding or the like. You may do it.

  Moreover, in this embodiment, although the fixing member 9 fixed the joining part 80 to the inner peripheral surface 44 of the hole part 43 of the slit part 45, it is not restricted to the form in which the fixing member 9 covers the whole joining part 80, but a joining part A configuration may be adopted in which a part of 80 is fixed to the inner peripheral surface 44. Further, the fixing member 9 does not have to fill the inside of the hole portion 43, and may be provided, for example, only at a portion connected to the slit portion 45 in the hole portion 43. It is enough if possible. Moreover, although the fixing member 9 was cement mainly composed of alumina, it is not limited to this. For example, a cement mainly composed of magnesia may be used, and a ceramic adhesive, a UV curable adhesive, or the like may be used in addition to the cement.

  In the present embodiment, the thermistor sintered body 21 corresponds to the “heat sensitive part” of the present invention. The dumet line 22 corresponds to a “first conductive line”. The thermistor element 2 corresponds to a “thermal element”. The leading end portion 81 of the conductive wire 8 corresponds to “one end” of the second conductive wire. The rear end portion 82 of the conductive wire 8 corresponds to the “other end” of the second conductive wire. The conductive line 8 corresponds to a “second conductive line”. The insulating tube 4 corresponds to an “insulating member”. The tip 47 of the insulating tube 4 corresponds to the “first end” in claims 2 and 3, and the tip 147 corresponds to the “first end” in claim 4. The rear end 50 of the insulating tube 4 corresponds to the “second end” in claims 2 and 3, and the rear end 150 corresponds to the “second end” in claim 4.

2 Thermistor element 4,104 Insulating tube 8,108 Conductive wire 9 Fixing member 21 Thermistor sintered body 22 Dumet wire 43,143 Hole 44,144 Inner peripheral surface 45,145 Slit 46,146 Outer peripheral surface 47,147 Tip 50 , 150 Rear end 80, 180 Joint portion 81, 181 Front end portion 82, 182 Rear end portion 100 Temperature sensor

Claims (5)

A thermosensitive element having a resistance value that varies depending on temperature; and a thermosensitive element that has a pair of first conductive wires that extend along the extending direction and are connected to the thermosensitive section at one end side, and
A second extending along the extending direction, one end side of which is connected to the other end of the first conductive wire, and the other end side thereof is directed to the side opposite to the one end side of the first conductive wire. Conductive wire;
An insulating insulating member having a pair of holes extending in the extending direction and penetrating itself in the extending direction, wherein the other end of the first conductive wire and one end of the second conductive wire are joined Insulating members that respectively arrange the joints to be placed in the holes;
A temperature sensor comprising:
A pair that is provided in a groove shape extending along the extending direction on an outer peripheral surface of the insulating member corresponding to an arrangement position of the joint portion in at least the hole portion, and connects the inside and the outside of the pair of hole portions. Slit part of
A fixing member that is provided at least in the portion connected to the slit portion of the hole portion and fixes at least the joint portion to the inner peripheral surface of the hole portion;
With
The opening width of the slit portion is smaller than the hole diameter of the hole portion, and the second conductive wire having a cross-sectional shape including a dimension larger than the opening width of the slit portion is arranged in the hole portion. A temperature sensor characterized by that.   The insulating member is arranged in the extending direction from the first end portion which is an end portion on the side where one end side of the first conductive wire is arranged when the joining portion is arranged in the hole portion. The temperature sensor according to claim 1, wherein an opening of the slit portion is formed on the outer peripheral surface extending to a position.   In the extending direction, the insulating member extends from the first end to a position closer to the second end that is the end opposite to the first end than the position where the joint is disposed. The temperature sensor according to claim 2, wherein an opening of the slit portion is formed on an outer peripheral surface.   In the extending direction, the insulating member extends from the first end portion, which is the end portion on the side where the one end side of the first conductive wire is disposed, when the joining portion is disposed in the hole portion. 2. The temperature sensor according to claim 1, wherein an opening of the slit portion is formed on the outer peripheral surface extending to a second end portion that is an end portion on the opposite side.   In the cross section of the insulating member that is orthogonal to the extending direction and includes the formation position of the slit portion, the pair of slit portions has a distance between the inner peripheral surface of the pair of hole portions and the outer peripheral surface of the insulating member. The temperature sensor according to any one of claims 1 to 4, wherein the temperature sensor is formed in each of the smallest portions.

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