US-12618720-B2 - Temperature sensor and method of manufacturing temperature sensor
Abstract
A temperature sensor includes: a thermosensitive element including a thermosensitive body, an extension wire having one end electrically connected to the thermosensitive body, and a sealing body made of an insulation material and covering a part of the extension wire and the thermosensitive body; a lead wire electrically connected to another end of the extension wire; and a covering body made of a resin and having a long shape and a rectangular cross-section, the covering body covering a part of the lead wire and the thermosensitive element. In a lateral direction of the covering body, a dimension of a region of the covering body covering the thermosensitive element is set less than a dimension of a region of the covering body covering the lead wire.
Inventors
- Takamasa Yoshihara
- Michiru TAKEMURA
Assignees
- SHIBAURA ELECTRONICS CO., LTD.
Dates
- Publication Date
- 20260505
- Application Date
- 20211014
Claims (7)
- 1 . A temperature sensor, comprising: a thermosensitive element including a thermosensitive body, an extension wire having one end electrically connected to the thermosensitive body, and a sealing body that is made of an insulation material and covers a part of the extension wire and the thermosensitive body; a lead wire electrically connected to another end of the extension wire of the thermosensitive element; and a covering body that is made of a resin and has a long shape and a rectangular cross-section, the covering body covering a part of the lead wire and the thermosensitive element, wherein in a first direction in the rectangular cross-section of the covering body, a thickness of a region of the covering body covering the thermosensitive element is set less than a thickness of a region of the covering body covering the lead wire, in a second direction orthogonal to the first direction in the rectangular cross-section of the covering body, the thickness of the region of the covering body covering the thermosensitive element is set less than the thickness of the region of the covering body covering the lead wire, the region of the covering body covering the thermosensitive element is formed in a rectangular-parallelepiped shape, and each of the region of the covering body covering the thermosensitive element and the region of the covering body covering the lead wire have a rectangular cross-section having a constant thickness in the first direction and a constant thickness in the second direction, and wherein a boundary is formed between the region of the covering body covering the thermosensitive element and the region of the covering body covering the lead wire.
- 2 . The temperature sensor according to claim 1 , wherein the lead wire includes a core wire connected to the extension wire and a covering provided around the core wire, and in the first or second direction of the covering body, the thickness of the region of the covering body covering the thermosensitive element is set less than an outer diameter of the covering of the lead wire.
- 3 . The temperature sensor according to claim 1 , wherein the region of the covering body covering the lead wire is formed in a rectangular-parallelepiped shape.
- 4 . The temperature sensor according to claim 1 , wherein a pair of the extension wires of the thermosensitive element are drawn out toward one side from the thermosensitive body, the sealing body is disposed in the region of the covering body covering the thermosensitive element, and a joint portion of each of the extension wires and the respective lead wire is disposed in the region of the covering body covering the lead wire.
- 5 . The temperature sensor according to claim 4 , wherein a center of the cross-section of the region of the covering body covering the thermosensitive element and a center of the cross-section of the region of the covering body covering the lead wire are coincident with each other.
- 6 . The temperature sensor according to claim 4 , wherein the thickness in the first or second direction of the region of the covering body covering the thermosensitive element is reduced toward an end of the covering body.
- 7 . A method of manufacturing a temperature sensor, the temperature sensor including a thermosensitive element including a thermosensitive body, a lead wire connected to the thermosensitive element, and a covering body that is made of a resin and has a long shape, the covering body covering a part of the lead wire and the thermosensitive element, the method comprising: a housing step of housing the part of the lead wire and the thermosensitive element inside a material made of a resin; a heating step of heating the material; and a pressure forming step of pressurizing the material to form the material in a shape having a rectangular cross-section, wherein in the pressure forming step, in a first direction in the rectangular cross-section of the covering body and in a second direction orthogonal to the first direction in the rectangular cross-section of the covering body, a thickness of a region of the covering body covering the thermosensitive element is set less than a thickness of a region of the covering body covering the lead wire by deforming, by pressurization, the material on the thermosensitive element side by a deformation amount greater than a deformation amount of the material on the lead wire side, the region of the covering body covering the thermosensitive element is formed in a rectangular-parallelepiped shape, and each of the region of the covering body covering the thermosensitive element and the region of the covering body covering the lead wire have the rectangular cross-section having a constant thickness in the first direction and a constant thickness in the second direction, and wherein a boundary is formed between the region of the covering body covering the thermosensitive element and the region of the covering body covering the lead wire.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS This is a National Stage application of PCT international application PCT/JP2021/038098, filed on Oct. 14, 2021, the contents of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present invention relates to a temperature sensor and a method of manufacturing the temperature sensor. BACKGROUND ART A temperature sensor including a thermosensitive element such as a thermistor is widely used (for example, Patent Literature 1). To protect the thermosensitive element from, for example, a surrounding environment, a covering body made of a resin material is provided for the thermosensitive element and a predetermined range of a lead wire connected to the thermosensitive element. A temperature sensor disclosed in Patent Literature 1 includes a covering body that includes an inner layer and an outer layer and is formed in a rectangular-parallelepiped shape. The outer layer is higher in melting point than the inner layer and has heat shrinkability. Such a covering body includes an inside tube housing the thermosensitive element and an outside tube to be externally inserted into the inside tube, and is formed to have a constant thickness enough to house a lead wire in the covering body by, for example, heat processing and press processing. CITATION LIST Patent Literature Patent Literature 1: JP 5830636 B2 SUMMARY OF INVENTION Technical Problem With improvement in performance of an apparatus on which the temperature sensor is to be mounted, performance improvement of the temperature sensor is constantly required. The covering body covering the thermosensitive element and the predetermined range of the lead wire influences on responsiveness of the temperature sensor. In particular, in a small-sized temperature sensor, the covering body largely influences on the responsiveness. Therefore, a first objective of the present invention is to provide a temperature sensor that can further improve responsiveness, and a method of manufacturing the temperature sensor. Further, since a thickness of the temperature sensor is determined with a diameter of a lead wire as a reference, it is difficult to install the temperature sensor depending on a shape and a dimension of an object on which the temperature sensor is installed. Therefore, together with or in place of the first objective, a second objective of the present invention is to provide a temperature sensor that can improve installation flexibility, and a method of manufacturing the temperature sensor. Solution to Problem A temperature sensor according to the present invention includes: a thermosensitive element including a thermosensitive body, an extension wire having one end electrically connected to the thermosensitive body, and a sealing body that is made of an insulation material and covers a part of the extension wire and the thermosensitive body; a lead wire electrically connected to another end of the extension wire of the thermosensitive element; and a covering body that is made of a resin and has a long shape and a rectangular cross-section, the covering body covering a part of the lead wire and the thermosensitive element. In a lateral direction of the covering body, a dimension of a region of the covering body covering the thermosensitive element is set less than a dimension of a region of the covering body covering the lead wire. In the temperature sensor according to the present invention, the lead wire preferably includes a core wire connected to the extension wire and a covering provided around the core wire, and in the lateral direction of the covering body, the dimension of the region of the covering body covering the thermosensitive element is preferably set less than an outer diameter of the covering of the lead wire. In the temperature sensor according to the present invention, the lateral direction is preferably at least one of a first direction and a second direction orthogonal to the first direction, in the rectangular cross-section. In the temperature sensor according to the present invention, either one of the region of the covering body covering the thermosensitive element and the region of the covering body covering the lead wire is preferably formed in a rectangular-parallelepiped shape. In the temperature sensor according to the present invention, in a first direction in the rectangular cross-section, a dimension of the region of the covering body covering the thermosensitive element is preferably set less than a dimension of the region of the covering body covering the lead wire, and in a second direction orthogonal to the first direction in the rectangular cross-section, a dimension of the region of the covering body covering the thermosensitive element is preferably set less than a dimension of the region of the covering body covering the lead wire. In the temperature sensor according to the present invention, a pair of the extension wires of the thermosensitive element are pre