Temperature Sensor

Abstract

To provide a temperature sensor where a mounting direction to a measurement part and a connection direction to an external connector are perpendicular to each other, which secures high airtightness by an O ring mounted on the temperature sensor.SOLUTION: A temperature sensor includes a resin molding, an O ring on which the resin molding is mounted, and a metal case to which the resin molding is inserted, wherein a terminal includes a first terminal region in a first direction and a second terminal region in a second direction, the resin molding has a first region in which a temperature-sensitive element is arranged, a third region in which the terminal is arranged, and a second region arranged between the first region and the third region, the third region has a parting line along a side face of the terminal, the second region has a parting line along a ridge line on a side opposite to the first region in the first direction, and a parting line is not arranged in the first region.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a temperature sensor in which the direction of attachment to a measuring unit and the direction of connection to an external connector are perpendicular to each other. [Background technology]

[0002] Patent Document 1 discloses a temperature sensor configured so that the attachment direction to the measurement unit and the connection direction to the external connector are orthogonal. This temperature sensor is manufactured using a resin molding device that uses a pair of molds. Because this temperature sensor has a structure in which the attachment direction to the measurement unit and the connection direction to the external connector are orthogonal, the terminal of the temperature sensor that is electrically connected to the external connector is bent at a right angle in the middle. Furthermore, the temperature sensor must ensure airtightness both inside and outside the measurement unit. For this reason, an O-ring is attached to the temperature sensor at the attachment point to the measurement unit.

[0003] The resin molding device is positioned so that one of the molds supports the tip of the terminal, and therefore the parting line formed on the contact surface of the pair of molds is formed along the mounting direction of the temperature sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-38832 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in such a temperature sensor, the O-ring is placed across the parting line, which causes the O-ring to partially lift off the surface of the temperature sensor, making it difficult to ensure a high level of airtightness with the O-ring attached to the temperature sensor.

[0006] Therefore, an object of the present disclosure is to solve such problems and ensure a high level of airtightness using an O-ring attached to a temperature sensor. [Means for solving the problem]

[0007] To achieve this objective, the temperature sensor of the present disclosure comprises a resin molded body covering a portion of the terminal, the temperature-sensing element, and the lead wires, an O-ring to which the resin molded body is attached, and a metal case into which the resin molded body is inserted, wherein the terminal has a first terminal region along a first direction and a second terminal region along a second direction perpendicular to the first direction, and the resin molded body has a first region in which the temperature-sensing element is arranged, a third region in which the terminal is arranged, and a second region arranged between the first and third regions for positioning the O-ring, wherein the third region has a parting line along the side of the terminal, and the second region has a parting line along the ridge line on the opposite side of the first region in the first direction, and no parting line is arranged in the first region. [Effects of the Invention]

[0008] This structure ensures a high level of airtightness using the O-ring attached to the temperature sensor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an exploded perspective view of a temperature sensor according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of a temperature-sensitive member in the temperature sensor of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view of a temperature sensor of the present disclosure. [Figure 4] FIG. 4 is an exploded perspective view of a molding die for a resin molded body in a temperature sensor of the present disclosure. [Figure 5] FIG. 5 is a perspective view of a support member that supports the temperature-sensitive member of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0011] Fig. 1 is an exploded perspective view of a temperature sensor. Fig. 2 is a perspective view of a temperature sensing part used in the temperature sensor. Fig. 3 is a cross-sectional view of the temperature sensor. In this embodiment, directions that are perpendicular to each other are defined as a first direction D1, a second direction D2, and a third direction D3, and the side indicated by an arrow in each direction is defined as the leading end side, and the side opposite to the arrow side is defined as the trailing end side.

[0012] Temperature sensor 100 is attached to a device that contains a measurement object and detects the temperature of the measurement object. For example, the device is a radiator that includes a flow path, and the measurement object is radiator liquid. In this case, temperature sensor 100 is attached to the flow path that constitutes the radiator and detects the temperature of the radiator liquid flowing within the flow path.

[0013] The temperature sensor 100 comprises a temperature-sensitive member 10, a resin molded body 20, an O-ring 30, and a metal case 40. The temperature-sensitive member 1, shown by the dashed line, is disposed inside the resin molded body 20. As shown in FIG. 2, the temperature-sensitive member 10 comprises a temperature-sensitive element 11 for detecting heat, a pair of terminals 12 for electrical connection to the outside, and lead wires 13 for electrically connecting the temperature-sensitive element 11 and the terminals 12. The direction in which the temperature sensor 100 is attached to the device is a first direction D1, and the direction in which it is connected to the outside is a third direction D3.

[0014] The temperature sensing element 11 can be configured with a thermistor, a thermocouple, etc. As shown in Fig. 3, the temperature sensing element 11 is disposed on the tip side of the resin molded body 20 in the first direction D1.

[0015] The terminal 12 is made of a conductive metal such as stainless steel. The terminal 12 is disposed on the rear end side of the resin molded body 20 in the first direction D1. The terminal 12 has a bent portion 12A located midway between the tip in the first direction D1 and the tip in the third direction. The terminal 12 has a first terminal region 12B extending from the bent portion 12A to one end on the tip side in the first direction D1, and a second terminal region 12C extending from the bent portion 12A to the other end on the tip side in the third direction D3. The lead wire 13 is connected to the tip side of the first terminal region 12B. The tip side of the second terminal region 12C protrudes from the surface of the resin molded body 20. The tip side of the second terminal region 12C protruding from the resin molded body 20 is connected to an external circuit, electrically connecting the temperature sensing element 11 to the external circuit.

[0016] As shown in FIG. 3, the resin molded body 20 has a first region 20A, a second region 20B, and a third region 20C. The first region 20A, the second region 20B, and the third region 20C are arranged in this order from the front end to the rear end in the first direction D1. The resin molded body 20 may be made of a resin such as polybutylene terephthalate (PBT) or polyphthalamide (PPA). The first region 20A and the second region 20B are regions that are inserted into the metal case 40. The first region 20A includes a cylindrical region 20AA in which the temperature sensing element 11 is disposed and a connection region 20AB that connects the cylindrical region 20AA and the second region. The connection region 20AB has a tapered shape that widens from the rear end of the cylindrical region 20AA toward the second region 20B. The second region 20B has a larger diameter than the first region 20A. The third region 20C is disposed outside the metal case 40. The third region 20C has a recess 20CA that opens at its tip along the third direction. The tip of the second terminal region 12C protrudes into the recess 20CA and is used as a connector for connecting to an external circuit.

[0017] The O-ring 30 is inserted from the tip side of the first region 20A of the resin molded body 20, and is disposed at a position where it abuts against the main surface on the tip side of the second region 20B.

[0018] The metal case 40 can be made of stainless steel or brass. The metal case 40 has a recess 40A into which the resin molded body 20 is inserted. The first region 20A and the second region 20B of the resin molded body 20 are inserted into the recess 40A. The recess 40A has a step portion 40B and a step portion 40C. The step portion 40B and the step portion 40C are arranged in order toward the rear end side in the first direction D1. The first region 20A of the resin molded body 20 is arranged on the front end side by the step portion 40B of the recess 40A. The second region 20B of the resin molded body 20 is arranged between the step portion 40B and the step portion 40C of the recess 40A. The third region 20C of the resin molded body 20 and the O-ring 30 are arranged on the rear end side by the step portion 40C of the recess 40A. The resin molded body 20 restricts its insertion position relative to the metal case 40 by abutting the main surface of the tip side of the second region 20B against the main surface of the rear end side of the stepped portion 40C via the O-ring 30.

[0019] Next, a method for manufacturing the temperature sensor 100 will be described. The temperature sensor 100 is manufactured by resin molding a previously prepared temperature-sensitive member 10 to create a resin molded body 20. Next, as shown in Fig. 1, an O-ring 30 is attached to the front end side of the resin molded body 20, and the resin molded body 20 with the O-ring 30 attached is inserted into a recess 40A in a metal case 40. Then, as shown in Fig. 3, the open end of the recess 40A is crimped to the main surface of the rear end side of the second region 20B of the resin molded body 20, thereby completing the manufacturing of the temperature sensor 100.

[0020] Next, resin molding of the resin molded body 20 will be described. FIG. 4 is an exploded perspective view of a molding die used for resin molding. The molding die 50 can be composed of a slide die 51 and a split die 52. The slide die 51 has a cavity 51A that forms the first region 20A and the second region 20B of the resin molded body 20. The split die 52 is composed of a first mold 53, a second mold 54, and a third mold 55. The first mold 53 has a cavity 53A that forms the rear end portion of the third region 20C in the third direction D3. The second mold 54 has a cavity 54A that forms the front end portion of the third region 20C in the third direction D3 and the portion further front than the second terminal region 12C in the first direction D1. The third mold 55 has a cavity 55A (not shown) that forms the leading end portion of the third region 20C in the third direction D3 and the rear end portion of the second terminal region 12C in the first direction D1. An insertion portion 56 that supports the protrusion of the second terminal region is formed on the mating surface of the second mold 54 and the third mold 55. In other words, the split mold 52, which is a combination of the first mold 53, the second mold 54, and the third mold 55, forms a cavity that forms the third region 20C in the resin molded body 20.

[0021] By resin-molding the resin molded body 20 using such a molding die 50, it is possible to ensure with high precision the airtightness provided by the O-ring 30, which is a component of the temperature sensor 100. That is, the molding die 50 is composed of a combination of a slide die 51 and a split die 52. Therefore, the parting lines formed on the resin molded body 20 are a line along the mating surfaces of the slide die 51 and the split die 52, a line along the mating surfaces of the first die 53 and the second die 54, a line along the mating surfaces of the first die 53 and the third die 55, and a line along the mating surfaces of the second die 54 and the third die 55.

[0022] That is, as shown in FIG. 1 , the parting line 60 formed in the resin molded body 20 includes a parting line 60A, a parting line 60B, and a parting line 60C. The parting line 60A is formed on the ridge line on the rear end side of the second region 20B of the resin molded body 20 in the first direction D1. The parting line 60B is formed along the side surface of the terminal 12 in the first terminal region 12B in the third region 20C of the resin molded body 20. The parting line 60C is formed along the side surface of the terminal 12 in the second terminal region 12C in the third region 20C of the resin molded body 20. The parting line 60C is not formed in the first region 20A of the resin molded body 20. In other words, the parting line 60 is not formed on the surface of the first region 20A and the main surface on the front side of the second region 20B, which come into contact with the O-ring 30 when the O-ring 30 is attached to the resin molded body 20. This prevents the O-ring 30 from coming into contact with the parting line 60, preventing the O-ring 30 from floating due to the parting line 60. In other words, the O-ring 30 attached to the temperature sensor 100 ensures a high level of airtightness for the temperature sensing element 11 arranged inside the metal case 40.

[0023] Furthermore, when resin molding the resin molded body 20, it is necessary to make the temperature-sensitive member 10 easy to handle. That is, as explained in FIG. 2, the temperature-sensitive member 10 is constructed by connecting a pair of terminals 12 and a temperature-sensitive element 11 with lead wires 13, and therefore the positional relationship between the pair of terminals 12 becomes unstable. This makes it difficult to handle the temperature-sensitive member 10 during resin molding. Therefore, it is preferable to use a support 70 that supports the pair of terminals 12 to position the pair of terminals 12 relative to each other. A perspective view of the support 70 is shown in FIG. 5. Note that in FIG. 5, the temperature-sensitive member 10 is indicated by a dashed line. The support 70 has a first flat plate region 70A extending in a first direction D1 and a second flat plate region 70B extending in a third direction D3. A pair of grooves 71 are arranged in the first flat plate region 70A and the second flat plate region 70B. The first terminal region 12B is fitted into the groove 71 in the first flat plate region 70A. The second terminal region 12C is fitted into the groove 71 in the second flat plate region 70B.

[0024] In resin molding using the support 70, the support 70 is placed in the cavity of the molding die 50, so it is important to stabilize the flow of resin in the cavity and to position the support 70. Therefore, in the resin molded body 20, the positioning of the support 70 is achieved by exposing a portion of the support 70 on the surface of the resin molded body 20. According to this configuration, in the resin mold molding, the end of the terminal 12 of the temperature-sensitive member 10 protruding from the third region of the resin molded body 20 is clamped by the insertion portion 56 of the molding die 50, and the portion of the support 70 exposed on the surface of the resin molded body 20 abuts against the molding die 50. This positions the support 70 in the cavity of the molding die 50.

[0025] In consideration of the positioning accuracy of the support 70, it is desirable to configure the exposed surface at a location away from the protruding portion of the terminal 12 protruding from the third region 20C. In other words, it is preferable to position the exposed surface on the tip side of the support 70 in the first direction D1. For example, the tip side of the first flat plate region 70A of the support 70 is exposed as the exposed surface from the surface of the first region 20A of the resin molded body 20. More preferably, a tapered surface is formed on the tip side of the first flat plate region 70A of the support 70, and this tapered surface is exposed as the exposed surface from the tapered surface of the connection region 20AB, which is part of the first region 20A of the resin molded body 20. [Industrial Applicability]

[0026] The present invention has the effect of ensuring high levels of airtightness using an O-ring for temperature sensors in which the attachment direction to the measurement part and the connection direction to the external connector are perpendicular, and is particularly effective for automotive temperature sensors in harsh operating environments. [Explanation of symbols]

[0027] 100 Temperature Sensor 11 Thermosensor Terminal 12 12B First Terminal Area 12C Second Terminal Area 13 Lead wire 20 Resin molding 20A First Area 20B Second Area 20C Third Region 30 O-rings 40 Metal Case 60, 60A, 60B, 60C parting line 70 Support D1 First direction D2 Second direction

Claims

1. a temperature-sensing element disposed on one end side in the first direction; a pair of terminals arranged on the other end side in the first direction; a lead wire configured to connect the temperature-sensing element and the terminal; a resin molded body configured to cover a portion of the terminal, the temperature sensing element, and the lead wire; an O-ring to which the resin molded body is attached; a metal case into which the resin molded body is inserted, the terminal includes a first terminal area along the first direction and a second terminal area along a second direction perpendicular to the first direction; the lead wire is connected to the first terminal area; The resin molded body is a first region in which the temperature sensitive element is disposed; a third area in which the terminal is disposed; a second region disposed between the first region and the third region and configured to position the O-ring; The third region has a parting line along a side surface of the terminal, the second region has a parting line along a ridge line on an opposite side of the first region in the first direction, No parting line is disposed in the first region, Furthermore, the resin molded body has a support body therein for supporting the terminal, a part of the support body is exposed in the first region of the resin molded body; Temperature sensor.

2. The temperature sensor according to claim 1 , wherein the surface of the support exposed from the resin molded body is a tapered surface inclined with respect to the first direction.

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