thermistor

Abstract

To provide a thermistor that can improve its detection accuracy.SOLUTION: A thermistor 1 comprises: a holding member 3 that is assembled on a wall part partitioning the inside and outside of a housing member from each other; and a thermistor body 5 that is held by the holding member 3 and detects the temperature inside the housing member. The thermistor body 5 has a thermistor element that detects temperature, lead wires 31 that are electrically connected with the thermistor element, and a resin part 33 that covers the thermistor element and from which the lead wires 31 are lead out to the outside. The holding member 3 has a holding part 11 that holds the resin part 33 and arranges the thermistor element inside the housing member, and a lead-out part 13 that leads out the lead wires 31 to the outside of the housing member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a thermistor. [Background technology]

[0002] Conventionally, thermistors have been provided with a duct mounting member as a holding member that is attached to a wall that separates the inside and outside of a duct, which serves as a housing member. Also known is a thermistor body that is held by the duct mounting member and detects the temperature inside the duct (see Patent Document 1). In this thermistor, the thermistor body includes a thermistor element that detects temperature, lead wires electrically connected to the thermistor element, and a resin portion that is integral with the lead wires and covers them. By assembling the resin portion to the duct mounting member, the thermistor body is attached to the duct mounting member, and the thermistor element is positioned inside the duct. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-6323 Summary of the Invention [Problem to be solved by the invention]

[0004] In the thermistor of Patent Document 1, when the thermistor body is attached to the holding member, the lead wire is covered with a resin portion, and the resin portion is covered with the holding member. Therefore, the lead wire is doubly covered by the resin portion and the holding member, making it difficult for heat inside the housing member to be transferred to the lead wire. The lead wire is drawn to the outside of the housing member and is easily affected by the temperature outside the housing member. When heat inside the housing member is not easily transferred to the lead wire, the temperature difference between the inside of the housing member and the lead wire becomes large. A large temperature difference between the inside of the housing member and the lead wire may affect the temperature detected by the thermistor element that detects the temperature electrically connected to the lead wire, potentially reducing detection accuracy.

[0005] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a thermistor that can improve detection accuracy. [Means for solving the problem]

[0006] The thermistor of this embodiment comprises a holding member that is attached to a wall portion that separates the inside and outside of a housing member, and a thermistor main body that is held by the holding member and detects the temperature inside the housing member, the thermistor main body having a thermistor element that detects the temperature, lead wires electrically connected to the thermistor element, and a resin portion that covers the thermistor element and from which the lead wires are extended to the outside, and the holding member has a holding portion that holds the resin portion and positions the thermistor element inside the housing member, and a withdrawal portion that extends the lead wires to the outside of the housing member. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a thermistor that can improve detection accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a thermistor according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the thermistor according to the embodiment. [Figure 3] FIG. 1 is a cross-sectional view of a thermistor according to an embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view of a thermistor body of the thermistor according to the embodiment. [Figure 5] FIG. 2 is a perspective view of a thermistor body excluding a resin portion of the thermistor according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The thermistor according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0010] As shown in Fig. 1, the thermistor 1 according to this embodiment is used to detect the temperature inside a housing member (not shown), such as a duct that blows air to a battery unit mounted on a vehicle. By detecting the temperature inside the duct, the thermistor 1 can, for example, blow appropriate air from the duct and control the temperature of the battery unit. Controlling the temperature of the battery unit can stabilize the driving output of the battery unit to the vehicle.

[0011] As shown in FIGS. 1 to 5, the thermistor 1 includes a holding member 3 and a thermistor body 5. The holding member 3 and the thermistor body 5 are made of a material such as aluminum.

[0012] As shown in FIGS. 1 to 3, the holding member 3 is made of an insulating material such as polypropylene (PP resin). The holding member 3 is formed in a cylindrical shape so as to straddle the inside and outside of a wall (not shown) that separates the inside and outside of the housing member. The holding member 3 is attached to the wall by passing through a hole (not shown) formed through the wall of the housing member. The outer surface of the holding member 3 that is located on the wall is provided with a flange 7 that abuts against the outer surface of the outer side of the wall. The outer surface of the holding member 3 that is located on the inside of the housing member is provided with a pair of elastically deformable locking pieces 9, 9 that engage with the edges of the hole in the wall.

[0013] The holding member 3 is inserted into the hole in the wall portion from the outside to the inside of the housing member. At this time, the pair of locking pieces 9, 9 abut against the edge of the hole and are elastically deformed, allowing the holding member 3 to be inserted into the hole. As the insertion of the holding member 3 into the hole continues, the flange portion 7 abuts against the wall portion of the housing member, and the insertion of the holding member 3 is completed. At this time, the pair of locking pieces 9, 9 return to their original shape from elastic deformation and engage with the edge of the hole, and the holding member 3 is attached to the wall portion of the housing member. The holding member 3 includes a holding portion 11 and a pull-out portion 13.

[0014] The retaining portion 11 is provided in a portion of the retaining member 3 that is to be disposed inside the housing member. The retaining portion 11 is a space defined by the top surface of the insertion portion 15 that extends from the flange portion 7 toward the interior of the housing member and the inner surfaces of a pair of retaining walls 17, 17 that extend from the top surface of the insertion portion 15 toward the interior of the housing member. The outer surfaces of the pair of retaining walls 17, 17 are formed from a single member to which the base ends of the pair of locking pieces 9, 9 are continuous. The retaining portion 11 accommodates a resin portion 33 of the thermistor body 5, which will be described later. The retaining portion 11 is provided with an elastically deformable retaining piece 19 that extends from the top surface of the insertion portion 15 toward the interior of the housing member. When the resin portion 33 is accommodated in the retaining portion 11, the retaining piece 19 engages with the resin portion 33 to hold the thermistor body 5 in the retaining member 3. The retaining portion 11 is provided with a plurality of resin exposure portions 21 that expose the resin portion 33 accommodated in the retaining portion 11 to the outside. The exposed resin portion 21 is an opening between the pair of retaining walls 17, 17, between the pair of retaining walls 17, 17 and the retaining piece 19, and at the tip side of the pair of retaining walls 17, 17 and the retaining piece 19. By providing the exposed resin portion 21 in the retaining portion 11, the resin portion 33 can come into direct contact with the internal air inside the housing member, thereby improving the accuracy of temperature detection by the thermistor main body 5.

[0015] The lead-out portion 13 is provided in a portion of the holding member 3 that is disposed inside and outside the housing member. The lead-out portion 13 includes an insertion portion 15 and a cylindrical portion 23 that extends cylindrically from the flange portion 7 toward the outside of the housing member. The insertion portion 15 is provided with an insertion hole 25 that communicates with the holding portion 11 and the cylindrical portion 23 and through which a lead wire 31 of the thermistor body 5 (described later) can be inserted. The insertion portion 15 is provided with a lead wire exposed portion 27 that communicates with the insertion hole 25 and exposes the lead wire 31 inserted through the insertion hole 25 to the outside. The provision of the lead wire exposed portion 27 in the lead-out portion 13 allows the lead wire 31 to directly contact the air inside the housing member, allowing the temperature of the lead wire 31 to approach the temperature inside the housing member. The lead wire 31 inserted through the insertion hole 25 is disposed in the cylindrical portion 23. For example, a connector (not shown) electrically connected to a controller (not shown) that controls various mechanisms mounted on the vehicle can be fitted into the cylindrical portion 23. By fitting the connector into the cylindrical portion 23, the temperature inside the housing member detected by the thermistor main body 5 is input to the controller.

[0016] 1 to 5, the thermistor body 5 is attached to the holding member 3 before the holding member 3 is attached to the housing member. The thermistor body 5 includes a thermistor element 29, lead wires 31, and a resin portion 33.

[0017] The thermistor element 29 is made of, for example, an electronic component whose resistance changes with temperature. When the holding member 3 is assembled to the housing member, the thermistor element 29 is disposed inside the housing member and detects the temperature inside the housing member.

[0018] The lead wire 31 is made of a conductive material, and one end is electrically connected to the thermistor element 29. A plurality of lead wires 31 (two in this example) are provided for the thermistor element 29. The other end of the lead wire 31 is inserted through the insertion hole 25 of the insertion portion 15 and disposed inside the cylindrical portion 23 when the thermistor main body 5 is assembled to the holding member 3. When the holding member 3 is assembled to the housing member, one end of the lead wire 31 is disposed inside the housing member and the other end is disposed outside the housing member. The lead wire 31 is electrically connected to the controller via the connector by fitting the connector into the cylindrical portion 23.

[0019] The resin portion 33 is made of epoxy resin, an insulating material with better thermal conductivity than PP resin. The resin portion 33 is insert-molded into a rectangular parallelepiped shape so as to cover the thermistor element 29 and extend the lead wires 31 to the outside. When the thermistor body 5 is assembled to the holding member 3, the resin portion 33 is housed in the holding portion 11, and the holding pieces 19 are engaged, thereby holding the thermistor body 5 to the holding member 3. When the holding member 3 is assembled to the housing member, the resin portion 33 is placed inside the housing member, and the thermistor element 29 is placed inside the housing member.

[0020] Because the lead wires 31 are drawn to the outside of the resin portion 33, only the holding member 3 (insertion portion 15) is arranged around the lead wires 31 located inside the housing member. This facilitates heat transfer from the inside of the housing member to the lead wires 31, and the temperature of the lead wires 31 becomes closer to the temperature inside the housing member. When the temperature of the lead wires 31 becomes closer to the temperature inside the housing member, the influence on the temperature detected by the thermistor element 29 electrically connected to the lead wires 31 can be suppressed. This improves the accuracy of temperature detection by the thermistor element 29. In addition, because the resin portion 33 is made of epoxy resin with excellent heat conductivity, heat from the inside of the housing member can be easily transferred to the thermistor element 29, improving the accuracy of temperature detection by the thermistor element 29.

[0021] The thermistor body 5 is assembled to the holding member 3 by inserting the tip of the lead wire 31 into the insertion hole 25 from the holding portion 11 side of the holding member 3 before the holding member 3 is assembled to the housing member. Insertion of the thermistor body 5 into the holding member 3 is completed when the resin portion 33 abuts against the top surface of the insertion portion 15 and the step portion of the lead wire 31 abuts against the step portion of the insertion hole 25. At this time, the holding piece 19 of the holding portion 11 engages with the resin portion 33, and the thermistor body 5 is held by the holding member 3.

[0022] Such a thermistor 1 includes a holding member 3 attached to a wall separating the interior and exterior of a housing member, and a thermistor main body 5 held by the holding member 3 and detecting the temperature inside the housing member. The thermistor main body 5 includes a thermistor element 29 that detects temperature, lead wires 31 electrically connected to the thermistor element 29, and a resin portion 33 that covers the thermistor element 29 and from which the lead wires 31 are extended to the outside. The holding member 3 includes a holding portion 11 that holds the resin portion 33 and positions the thermistor element 29 inside the housing member, and an extension portion 13 that extends the lead wires 31 to the outside of the housing member.

[0023] Since the resin part 33 held by the holding part 11 has the lead wire 31 drawn out to the outside, only the holding member 3 is arranged around the lead wire 31 located inside the housing member. Therefore, heat from inside the housing member is easily transferred to the lead wire 31, and the temperature of the lead wire 31 becomes close to the temperature inside the housing member. If the temperature of the lead wire 31 becomes close to the temperature inside the housing member, the effect on the detection temperature of the thermistor element 29 electrically connected to the lead wire 31 can be suppressed.

[0024] Therefore, with such a thermistor 1, the detection accuracy can be improved.

[0025] Furthermore, the holding portion 11 is provided with a resin exposure portion 21 that exposes the resin portion 33 to the inside of the housing member.

[0026] Therefore, resin exposed portion 21 allows resin portion 33 to come into direct contact with the air inside the housing member, and the accuracy of temperature detection by thermistor body 5 can be improved.

[0027] Further, the lead-out portion 13 is provided with a lead wire exposure portion 27 that exposes the lead wires 31 to the inside of the housing member.

[0028] Therefore, the lead wire exposed portion 27 allows the lead wire 31 to come into direct contact with the air inside the housing member, and the temperature of the lead wire 31 can be made closer to the temperature inside the housing member.

[0029] The resin portion 33 is made of epoxy resin.

[0030] Therefore, the epoxy resin has excellent heat conductivity, making it easier for heat inside the housing member to be transferred to the thermistor element 29 arranged inside the resin part 33, thereby improving the accuracy of temperature detection by the thermistor element 29.

[0031] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment.

[0032] For example, although there are two lead wires, the number of lead wires is not limited to two, and three or more lead wires may be used. [Explanation of symbols]

[0033] 1 thermistor 3 Retaining member 5 Thermistor body 11 Holding part 13 Drawer section 21 Exposed resin part 27 Exposed lead wire 29 Thermistor element 31 Lead wire 33 Resin part

Claims

1. a holding member attached to a wall portion that separates the inside and outside of the housing member; a thermistor body held by the holding member and configured to detect the temperature inside the housing member; Equipped with the thermistor body includes a thermistor element for detecting temperature, lead wires electrically connected to the thermistor element, and a resin portion covering the thermistor element and from which the lead wires are drawn out; the holding member has a holding portion that holds the resin portion and positions the thermistor element inside the housing member, and a drawing portion that draws the lead wires to the outside of the housing member, The thermistor has a resin exposure portion in the holding portion that exposes the resin portion to the inside of the housing member.

2. A holding member attached to a wall portion that separates the inside and outside of a housing member; a thermistor body held by the holding member and configured to detect the temperature inside the housing member; Equipped with the thermistor body includes a thermistor element for detecting temperature, lead wires electrically connected to the thermistor element, and a resin portion covering the thermistor element and from which the lead wires are drawn out; the holding member has a holding portion that holds the resin portion and positions the thermistor element inside the housing member, and a drawing portion that draws the lead wires to the outside of the housing member, The thermistor has a lead wire exposure portion at the lead-out portion, which exposes the lead wire to the inside of the housing member.

3. 2. The thermistor according to claim 1, wherein the lead-out portion is provided with a lead-wire exposed portion that exposes the lead wire to the inside of the housing member.

4. 3. The thermistor according to claim 1, wherein the resin portion is made of an epoxy resin.

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