JP2018151271A - Temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature sensor having a separator capable of preventing variation of detection sensitivity in mass production.SOLUTION: A temperature sensor 100 includes: a case 10 having an opening 11; a temperature-sensitive part 20 disposed in the opening 11; a lead wire 30 connected to the temperature-sensitive part 20; a separator 40 disposed in the opening; and a resin member 60 filled in the opening 11. The separator 40 has a through hole 41 through which the lead wire 30 is inserted. The through hole 41 has a first segment 42 and a second segment 43. The first segment 42 is disposed closer to a temperature-sensitive part 20 side than the second segment 43. A hole diameter d1 of the first segment 42 is larger than a hole diameter d2 of the second segment 43.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a temperature sensor having a separator.

  In general, a temperature sensor has a structure in which a temperature sensing part connected to a lead wire is disposed in an opening of a case and the opening is sealed with a resin so that the lead wire is led out.

  As a method for manufacturing such a temperature sensor, Patent Document 1 discloses a method in which a temperature-sensitive portion connected to a lead wire is disposed in a case, and a sealing resin is poured and cured. Patent Document 2 discloses a method of inserting a temperature sensing part connected to a lead wire into the resin after pouring the resin into the case.

JP 2005-17088 A Japanese Patent Laid-Open No. 10-300589

  However, such a temperature sensor has a low strength because it is a structure in which the temperature sensing part is connected to the lead wire. For this reason, when the resin is poured into the temperature sensing portion or the resin is inserted into the temperature sensing portion, the temperature sensing portion receives stress from the resin, thereby changing the position of the temperature sensing portion inside the case. This variation in the position of the temperature sensing unit affects the detection sensitivity. For example, if the distance between the temperature sensing part and the case is small, the detection sensitivity for the external temperature increases, and if the distance between the temperature sensing part and the case is small, the detection sensitivity for the external temperature decreases. Therefore, when such temperature sensors are mass-produced, there is a problem that the detection sensitivity of each temperature sensor becomes unstable.

  Therefore, the present disclosure aims to solve such a problem and suppress variations in detection sensitivity in the temperature sensor.

  A temperature sensor according to an aspect of the present disclosure includes a case having an opening, a temperature sensing unit disposed in the opening, a first lead wire having one end connected to the temperature sensing unit, and one end serving as the temperature sensing unit. A second lead wire connected; a separator disposed closer to the opening end than the temperature sensing portion in the opening; and a resin member filled in the opening. The separator is inserted with the first lead. The first through hole and the second through hole into which the second lead wire is inserted. The first through hole and the second through hole each have a first hole diameter. The first section has a section and a second section having a second hole diameter, and the first section is disposed closer to the temperature sensitive part than the second section, and the first hole diameter is greater than the second hole diameter. Big and configured.

  The temperature sensor of this indication can control variation in detection sensitivity in mass production.

FIG. 1 is a cross-sectional view schematically illustrating a usage state of the temperature sensor according to the present disclosure. FIG. 2 is a cross-sectional view of a separator constituting the temperature sensor according to the present disclosure. FIG. 3 is a perspective view of a separator according to the present disclosure. FIG. 4 is a schematic diagram illustrating a method for manufacturing a temperature sensor according to the present disclosure. FIG. 5 is a front view of a separator according to another embodiment of the present disclosure. FIG. 6 is a front view of a separator according to another embodiment of the present disclosure. FIG. 7 is a perspective view showing a modified example of the separator.

  Hereinafter, a temperature sensor according to an embodiment of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a preferred specific example of the present disclosure. Accordingly, the shapes, components, arrangement of components, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. In each figure, substantially the same structure is denoted by the same reference numeral, and redundant description is omitted or simplified.

  FIG. 1 is a cross-sectional view schematically illustrating a usage state of the temperature sensor of the present disclosure. This temperature sensor 100 is attached to the radiator 200 of the car and measures the temperature of the cooling water 201 disposed inside the radiator 200. The measured temperature information of the cooling water 201 is fed back as engine control information and used for injection injection control and the like.

  The temperature sensor 100 includes a case 10, a temperature sensing unit 20, a pair of lead wires 30, a separator 40, a coupler 50, and a resin member 60 filled in the case 10.

  The case 10 is made of a metal material such as brass and has a bottomed opening 11. The opening 11 has a small opening diameter on the front end side of the temperature sensor 100, that is, on the bottom side of the opening 11, and a large opening diameter on the rear end side of the temperature sensor 100, that is, on the opening side of the opening 11. The tip side of the case 10 is inserted into a temperature detection region such as the cooling water 201. The rear end side of the case 10 has a bolt structure and is fixed to a detection target member such as the radiator 200. The bolt structure is, for example, a hexagon bolt.

  The temperature sensing unit 20 includes a temperature sensing element 21 that detects temperature, a pair of electrodes 22, and a pair of electrode wires 23. As the temperature sensitive element 21, for example, a thermistor element can be used. The temperature sensitive element 21 is disposed between the pair of electrodes 22. One end of the electrode wire 23a is connected to the electrode 22a. One end of the electrode wire 23b is connected to the electrode 22b. The temperature sensitive element 21 may be covered with an insulating member 24 such as glass. The other ends of the electrode wires 23a and 23b are led out from the insulating member 24 outward. The electrode wire 23a is connected to the lead wire 30a. The electrode wire 23b is connected to the lead wire 30b.

  The coupler 50 has a pair of connection terminals 51. The connection terminal 51a is connected to the lead wire 30a. The connection terminal 51b is connected to the lead wire 30b. The temperature sensor 100 is electrically connected to an external connection device (not particularly shown) via the connection terminal 51. The externally connected device is, for example, a vehicle control circuit.

The separator 40 is disposed on the opening end side of the opening 11. The separator 40 has a pair of through holes 41. A lead wire 30a is inserted into the through hole 41a. A lead wire 30b is inserted into the through hole 41b. The separator 40 can be formed of, for example, polyphenylene sulfide resin. The detail of the separator 40 is demonstrated using FIG. 2, FIG. FIG. 2 is a cross-sectional view of the separator 40. FIG. 3 is a perspective view of the separator 40 as viewed from the front end side of the temperature sensor 100. The through holes 41 arranged in the separator 40 each have a first section 42 and a second section 43 having different hole diameters. The first section 42 is disposed on the distal end side with respect to the second section 43, and the hole diameter d 1 is larger than the hole diameter d 2 of the second section 43. The hole diameter d1 of the first section 42 is 3 mm, for example. The hole diameter d2 of the second section 43 is 2 mm, for example. In addition, the separator 40 includes an outer peripheral wall 44 in the outer peripheral portion of the main surface 40a on the front end side. In the separator 40, a recess 45 is formed by the main surface 40 a on the front end side and the outer peripheral wall 44.

  The resin member 60 is filled in the opening 11. The resin member 60 is, for example, an epoxy resin. The resin member 60 hermetically seals the temperature sensing unit 20 inside the case 10. The resin member 60 fixes the separator 40 to the opening 11 of the case 10.

  Next, the manufacturing method of the temperature sensor 100 is demonstrated using FIG.

  First, as shown in FIG. 4A, a primary structure 70 in which the electrode wire 23 and the lead wire 30 in the temperature sensing unit 20 are connected is manufactured. The electrode wire 23 and the lead wire 30 can be connected using the connecting member 25. For the connection member 25, for example, a crimp band can be used. The crimp band is made of a plate-like metal. The crimping band can be integrated by bending the end portions of the lead wire 30 and the electrode wire 23 arranged side by side.

  Next, as shown in FIG. 4B, the primary structure 70 is immersed in a liquid coating resin 71, and the surface of the primary structure 70 is covered with the coating resin 71. The coating resin 71 is, for example, an epoxy resin. In addition, this coating resin 71 and the resin member 60 with which the opening part 11 mentioned above is filled can be made into the same material.

  Next, as shown in FIG. 4C, the lead wire 30 is inserted into the through hole 41 arranged in the separator 40. The lead wire 30 is inserted from the first section 42 side and led out from the second section 43 side. The lead wire 30 is inserted with the above-described coating resin 71 being unhardened. The coating resin 71 covering the lead wire 30 is removed at the edge 43 a in the second section 43 of the through hole 41 when the lead wire 30 is inserted into the through hole 41. That is, the resin thickness covering the lead wire 30 led out from the separator 40 to the rear end side can be adjusted by the hole diameter d2 of the second section 43. The resin thickness of the coating resin 71 covering the lead wire 30 led out from the separator 40 to the rear end side is reduced. Therefore, the strength is lowered even after the coating resin 71 described later is cured. As a result, it is possible to prevent the lead wire 30 from being damaged by the remaining cured resin. The offset between the diameter of the through hole 41 and the diameter of the lead wire 30 is preferably in the range of 0 mm to 0.5 mm. When the offset amount is 0.5 mm or more, the strength of the cured resin remaining after curing increases, and the probability of damaging the lead wire 30 increases. Since the lead wire 30 is covered with an elastic body such as fluoro rubber, the lead wire 30 can be inserted into the through hole 41 even if the offset from the through hole 41 is 0 mm.

  Further, the first section 42 disposed on the distal end side of the second section 43 can be used as an area for storing the coating resin 71 removed in the second section 43. As a result, unnecessary coating resin 71 is prevented from entering the side surface 40 c of the separator 40. Furthermore, it is possible to prevent the coating resin 71 that has entered the side surface 40c from entering the lead surface 30 of the main surface 40b on the rear end side. Moreover, by providing the concave portion 45 on the main surface 40a on the front end side of the separator 40, the volume of the area where unnecessary coating resin 71 is stored can be increased.

  Next, as shown in FIG. 4D, the coating resin 71 coated on the primary structure 70 is cured to produce the secondary structure 75. In addition, the process of hardening the coating resin 71 is performed in the state which supported the primary structure 70 so that the temperature-sensitive part 20 may become an upper side and the separator 40 may become a lower side, as the figure shows. As a result, the direction in which the uncured coating resin 71 hangs is the direction from the temperature sensing unit 20 toward the separator 40. That is, the film thickness of the coating resin 71 covering the tip side of the temperature sensing unit 20 is reduced. Therefore, even in mass production, the variation in the film thickness of the coating resin 71 covering the tip side of the temperature sensing unit 20 is reduced.

  Next, as shown in FIG. 4E, the case 10 in which the opening portion 11 is filled with the liquid resin member 60 is prepared, and the secondary structure 75 is attached to the opening portion 11 in which the resin member 60 is filled. Insert from the temperature sensing element 21 side. When the secondary structure 75 is inserted into the case 10, the secondary structure 75 may be inserted into the opening 11 of the case 10 and then the opening 11 may be filled with resin. Note that the strength of the secondary structure 75 is significantly increased compared to the primary structure 70 because the coated coating resin 71 is cured. In particular, the reinforcing effect in the electrode wire 23 with low strength is remarkable. With this strength reinforcement, when the secondary structure 75 is inserted into the resin member 60, deformation based on the viscosity of the resin member 60 is suppressed. Even when the opening 11 into which the secondary structure 75 is inserted is filled with the resin member 60, deformation due to the flow of the resin member 60 is suppressed. In any case, since the deformation of the secondary structure 75 is suppressed, variation in the position of the temperature sensing unit 20 within the opening 11 in mass production is suppressed. That is, variation in detection sensitivity of the temperature sensor 100 is suppressed in mass production.

  Next, as shown in FIG. 4F, the resin member 60 is cured, and the temperature sensor 100 is manufactured.

  As described above, the temperature sensor 100 has a structure in which the temperature sensor 100 is manufactured using the secondary structure 75 coated with the coating resin 71 shown in FIG. Variation in sensitivity is suppressed. Further, the connection member 25 is made larger by making the width W (see FIG. 4A) of the connection member 25 used to connect the electrode wire 23 and the lead wire 30 larger than the hole diameter d1 of the first section 42 of the through hole 41. Is arranged outside the first section 42. As a result, the first section 42 can be used as a region for storing unnecessary coating resin 71. Moreover, by providing the concave portion 45 on the main surface 40a on the front end side of the separator 40, the volume of the portion where the unnecessary coating resin 71 remains can be increased.

  Further, by providing the separator 40 with a protrusion that contacts the connecting member 25, the rotation operation of the lead wire 30 can be suppressed. 5 and 6 show examples of the arrangement of the protrusions. 5 and 6 are front views of the separator as viewed from the front end side of the temperature sensor. The separator 401 shown in FIG. 5 shows an example in which a protrusion 46a is disposed in a portion adjacent to the through hole 41a and a protrusion 46b is disposed in a portion adjacent to the through hole 41b on the inner peripheral surface of the outer peripheral wall 44. Each of the protrusions 46 a and 46 b has a structure having a groove 48 between the pair of protrusions 47. The end of the connection member 25 is inserted into the groove 48. The connection member 25 is inserted into the groove 48 when the lead wire 30 is inserted into the through hole 41 in FIG. Since the end portion of the connecting member 25 contacts the convex portion 47, the lead wire 30 is prevented from rotating.

  Further, the separator 402 shown in FIG. 6 is an example in which a protrusion 46c is disposed in the vicinity of the through-hole 41a on the main surface 40a on the front end side of the separator 402, and a protrusion 46d is disposed in the vicinity of the through-hole 41b. Show. Each of the protrusions 46 c and 46 d has a structure having a groove 48 between the pair of protrusions 47. The end of the connection member 25 is inserted into the groove 48. The connection member 25 is inserted into the groove 48 when the lead wire 30 is inserted into the through hole 41 in FIG. Since the end portion of the connecting member 25 contacts the convex portion 47, the lead wire 30 is prevented from rotating.

  Note that when the lead wire 30 rotates with respect to the separator 40, the lead wire 30 and the electrode wire 23 are twisted, and the position of the temperature sensing unit 20 with respect to the separator 40 changes. Therefore, by increasing the positional accuracy of the temperature sensing unit 20 with respect to the separator 40, variation in detection sensitivity of the temperature sensor 100 in mass production can be suppressed.

  A modification of the separator is shown in FIG. The separator 403 shown in FIG. 7 has a notch 80 connecting the inner side and the outer side of the outer peripheral wall at the end of the outer peripheral wall 44. The notch 80 can promote the flow of the resin member 60 in the step of arranging the secondary structure 75 described with reference to FIG. It is preferable to arrange at least three notches 80. By arranging the three notches 410, the three protrusions 81 formed between the adjacent notches 80 become three. Since the protruding portion 81 is a contact portion with the inner peripheral portion of the case 10, the arrangement accuracy of the separator 403 with respect to the case 10 can be stabilized by using three protruding portions.

  The present disclosure is particularly effective in a water temperature sensor attached to a radiator.

DESCRIPTION OF SYMBOLS 10 Case 11 Opening part 20 Temperature sensing part 21 Temperature sensing element 23 Electrode line 23a 1st electrode line 23b 2nd electrode line 25 Connection member 30 Lead wire 30a 1st lead wire 30b 2nd lead wire 40,401, 402, 403 Separator 41a First through hole 41b Second through hole 42 First section 43 Second section 45 Recess 46a, 46c First protrusion 46b, 46d Second protrusion 60 Resin member 100 Temperature sensor d1 1st hole diameter d2 2nd hole diameter

Claims (4)

A case having a bottomed opening, and
A temperature sensing part disposed on the bottom side of the opening;
A first lead wire having one end connected to the temperature sensing unit;
A second lead wire having one end connected to the temperature sensing unit;
A separator disposed on the opening end side from the temperature sensing part in the opening,
A resin member filled in the opening,
The separator has a first through hole into which the first lead wire is inserted, and a second through hole into which the second lead wire is inserted,
Each of the first through hole and the second through hole has a first section having a first hole diameter and a second section having a second hole diameter,
The first section is disposed closer to the temperature sensing unit than the second section,
The first hole diameter is larger than the second hole diameter;
Temperature sensor. The temperature sensor
A temperature sensing element for detecting the temperature;
A first electrode wire having one end connected to the temperature sensing element;
A second electrode wire having one end connected to the temperature sensitive element;
The first lead wire is connected to the first electrode wire by a first connecting member;
The second lead wire is connected to the second electrode wire by a second connecting member;
A width of the first connecting member is larger than a diameter of the first through hole;
A width of the second connecting member is larger than a diameter of the second through hole;
The temperature sensor according to claim 1. The separator includes a first protrusion and a second protrusion,
The first protrusion is in contact with the first connecting portion;
The second protrusion is in contact with the second connecting portion;
The temperature sensor according to claim 2. A concave portion is formed on the main surface of the separator on the side of the temperature sensitive portion,
The opening end of the first section is disposed on the bottom surface of the recess.
The temperature sensor according to claim 1.

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