Temperature sensor and heating cooker
A temperature sensor includes a protective tube made of metal, a sensor element including a thermosensitive body and a pair of conductive wires electrically connected to the thermosensitive body and accommodated in the protective tube, a first heat-resistant insulator for ensuring electrical insulation of the pair of conductive wires inside the protective tube, and a second heat-resistant insulator provided between the first heat-resistant insulator and the protective tube for ensuring electrical insulation between the conductive wires and the protective tube.
1 . A temperature sensor, comprising:
a protective tube made of metal;
a sensor element including a thermosensitive body and a pair of conductive wires electrically connected to the thermosensitive body and accommodated in the protective tube;
a first heat-resistant insulator that electrically insulates the pair of conductive wires inside the protective tube; and
a cylindrical second heat-resistant insulator made of solid glass and provided between the first heat-resistant insulator and the protective tube that electrically insulates the protective tube from the pair of conductive wires, wherein
the sensor element further includes:
a covering body covering a periphery of the thermosensitive body; and
a support tube joined to an end portion of the covering body and having a higher mechanical strength than the covering body, and
an end portion of the cylindrical second heat-resistant insulator is fitted to an outside of the support tube in a radial direction of the cylindrical second heat-resistant insulator.
2 . The temperature sensor according to claim 1 , wherein each of the pair of conductive wires is independently inserted through the first heat-resistant insulator.
3 . The temperature sensor according to claim 1 , wherein only one of the pair of conductive wires is inserted through the first heat-resistant insulator.
4 . The temperature sensor according to claim 1 , further comprising:
a pair of cylindrical insulators comprising an electrically insulating material that electrically insulates the pair of conductive wires, wherein
the pair of conductive wires is inserted through the first heat-resistant insulator in a first area which is an area on a side of an end portion of the protective tube having the end portion which is closed at a front, and is respectively inserted through the pair of cylindrical insulators in a second area at a rear of the first area.
5 . The temperature sensor according to claim 4 , wherein the cylindrical second heat-resistant insulator straddles the pair of cylindrical insulators covering the pair of conductive wires on a rear side.
6 . The temperature sensor according to claim 5 , wherein the pair of conductive wires is mechanically fixed to the protective tube by crimping through a crimping protective covering in an area of the pair of conductive wires where the pair of cylindrical insulators is provided.
7 . The temperature sensor according to claim 4 , wherein:
the protective tube further includes a flange that extends in a direction intersecting a length direction of the protective tube; and
a dimension of the cylindrical second heat-resistant insulator in the length direction is set equal to or less than a dimension in the length direction from the end portion of the protective tube to a position where the flange is provided.
8 . The temperature sensor according to claim 7 , wherein:
the pair of conductive wires is mechanically fixed to the protective tube by crimping through a crimping protective covering in an area of the pair of conductive wires where the pair of cylindrical insulators is provided; and
the crimping is applied at a rear of the position where the flange of the protective tube is provided.
9 . The temperature sensor according to claim 8 , wherein an outer surface of the protective tube is black.
10 . A heating cooker in which the temperature sensor according to claim 1 is arranged in a heating chamber.