JPH0630740U - Thermistor temperature sensor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a highly reliable thermistor temperature sensor which is excellent in heat resistance and mechanical strength and which prevents the influence of peeling of the copper layer of the lead wire. [Structure] The thermistor lead wire is covered with a metal pipe to the deepest part of the lead wire hole of the ceramic body, and is sealed by welding at the end of the metal pipe on the lead-out side, and at the same time connected to the conductor of the heat-resistant wire, Further, it is formed by covering a metal pipe with an insulation of a heat resistant electric wire. [Effect] Since the thermistor element is glass-sealed, stable electrical characteristics can be obtained, and since the thermistor lead wire is covered with a metal pipe, it has high heat resistance and can be used at high temperature. . Further, by coating the lead wire with a metal pipe, the mechanical strength is excellent, and by coating the metal pipe with the jacket insulator of the heat resistant electric wire, the electrical insulation can be further improved and the characteristics can be stabilized.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermistor temperature sensor, and more specifically, to a thermistor temperature sensor used for detecting the temperature of a heat generating part of a stove, a gas range, an automobile or the like.

[0002]

[Prior art]

 Conventionally, negative thermistors used for temperature detection are used in large quantities for temperature measurement and control of home appliances, automobiles, and other industrial equipment.

FIG. 2 shows a conventional thermistor temperature sensor, which has a structure mainly used at an ambient temperature of 200 ° C. to 300 ° C. In the figure, 2 is a thermistor element, 3 is a lead wire, 4 is a glass sealing body, 7 is a heat resistant electric wire, 7a is a conductor of the heat resistant electric wire 7, 7b is a heat resistant insulator, 7c is a jacket insulator, and 8 is a lead wire. Reference numeral 3 is a connecting portion between the conductor 7a of the heat resistant electric wire 7 and 9 is an insulating tube.

In the thermistor temperature sensor shown in FIG. 2, a thermistor element 2 having silver or silver-palladium alloy thick film electrodes on both sides is provided with a Dumet wire formed by covering an iron-nickel alloy wire with a copper tube. A glass-sealed thermistor is used in which one end of the pair of lead wires 3 used is connected and the whole except a part of the lead wire 3 is fusion-sealed by a glass-sealed body 4 to be integrated.

The lead wire 3 drawn out from the glass sealing body 4 is insulated between wires by an insulating tube 9 made of polyimide resin or fluorine resin, and is connected to the conductor 7 a of the heat resistant electric wire 7 by welding at a connecting portion 8. Constitutes a thermistor temperature sensor.

The thermistor temperature sensor shown in FIG. 2 is housed in a bottomed metal protection tube (not shown), and a gap inside the metal protection tube is filled with silicon grease, which is a heat conductive insulating material, and sealed.

[0007]

[Problems to be solved by the device]

 If the temperature of the heat generating part of the stove, gas range, automobile, etc. is abnormal, or if the temperature is temporarily raised, the ambient temperature will rise even higher, so a product with higher heat resistance and reliability is required. To be done.

The conventional thermistor temperature sensor has a drawback in the heat resistance of the insulating tube electrically insulating between the lead wires of the thermistor against a temperature change of 300 ° C. or more, and the insulating tube deteriorates and cracks. Further, the surface of the lead wire is oxidized and the copper layer is peeled off due to vibration and the like.

The silicon grease filled in the metal protection tube described above is decomposed and hardened by the silicon oil and fat, and cracks are generated.

Therefore, the debris of the copper layer peeled off from the lead wire of the thermistor temperature sensor moves between the lead wires due to vibration, and the electrical insulation between the lead wires decreases, resulting in lack of stability. is there.

The present invention is intended to solve such a problem of the prior art, prevents the influence of the copper layer peeling of the lead wire, and has high heat resistance and mechanical strength and high reliability. It is intended to provide a thermistor temperature sensor.

[0012]

[Means for Solving the Problems]

 The thermistor temperature sensor of the present invention comprises a thermistor element and a glass sealing body for sealing the lead wire of the thermistor element, and a ceramic body having two lead wire through holes integrally fused to each other. In a thermistor temperature sensor connected with an external heat-resistant wire, the lead wire of the thermistor is covered with a metal pipe up to the deepest part of the lead wire hole in the ceramic body, and sealed at the end of the metal pipe by welding. At the same time, it is connected to the conductor of the heat-resistant electric wire, and is further formed by covering the metal pipe with the insulator of the heat-resistant electric wire.

[0013]

[Action]

 According to the above configuration, the lead wire drawn out from the glass sealing body and the metal pipe that covers and protects the lead wire are completely insulated from each other inside the ceramic body, and the copper layer portion on the surface of the lead wire is also present. Since it is not exposed to the outside, there is no reduction in insulation due to the peeling of the copper layer.

By covering the lead wire with a metal pipe, the lead wire becomes strong against external force, and the electrical insulation between the metal pipes can be maintained as it is.

Since the metal pipe outside the ceramic body is electrically insulated by the jacket insulator of the heat-resistant wire, the insulation between the metal pipes is further improved.

Therefore, the thermistor temperature sensor of the present invention is mechanically strong, has improved heat resistance, and can stabilize electrical characteristics.

[0017]

【Example】

 FIG. 1 is a sectional view showing an embodiment of the thermistor temperature sensor of the present invention. The thermistor element 2 is formed by cutting a plate-like thermistor that has been fired to a predetermined size into small chips, and has thick film electrodes made of silver or silver-palladium alloy on both sides. is doing. The lead wire 3 is a Dumet wire in which an iron-nickel alloy wire is coated with a copper tube.

The thermistor element 2 and one end of the lead wire 3 are bonded to each other with a conductive paint containing silver or the like, and are baked and connected when the glass sealing body 4 is sealed. At the same time, the glass sealing body 4 and the ceramic body 5 made of fine ceramics having two lead wire through holes, tempered glass or the like are fused and integrally formed.

The lead wire 3 of the thermistor is covered with a metal pipe 6 made of a heat-resistant material such as stainless steel to the deepest part of the lead wire hole of the ceramic body 5 so that the copper layer portion on the surface of the lead wire 3 is not exposed. The end of the metal pipe 6 on the pull-out side is sealed.

The heat-resistant electric wire 7 is formed by concentrically coating a heat-resistant insulator 7b made of silica fiber or the like on a conductor 7a, such as a nickel wire, which can be electrically welded, and further glass fiber on the heat-resistant insulator 7b. The outer cover insulator 7c braided with is covered and treated with silicon varnish.

The lead wire 3 sealed at the end portion of the metal pipe 6 on the lead-out side is connected to the metal pipe 6 and the conductor 7 a of the heat resistant electric wire 7 by welding at the connecting portion 8 at the same time as the heat resistant electric wire 7 The metal pipe 6 is covered with the jacket insulator 7c to form a thermistor temperature sensor.

[0022]

[Effect of device]

 As described above, in the thermistor temperature sensor of the present invention, since the thermistor element is glass-sealed, stable electrical characteristics can be obtained, and the lead wire of the thermistor is covered with a metal pipe. Therefore, it has high heat resistance and can be used at high temperatures. Also, by coating the lead wire with a metal pipe, it has excellent mechanical strength, and by coating the metal pipe with the insulation of the heat-resistant wire, the electrical insulation can be further improved and the characteristics can be stabilized. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Thermistor Temperature Sensor 2 Thermistor Element 3 Lead Wire 4 Glass Sealing Body 5 Ceramic Body 6 Metal Pipe 7 Heat Resistant Electric Wire 7a Conductor 7b Heat Resistant Insulator 7c Outer Insulator 8 Connection 9 Insulation Tube

Claims (1)

[Scope of utility model registration request] 1. A thermistor, a glass encapsulant for encapsulating the lead wire of the thermistor element, and a thermistor in which a ceramic body having two lead wire through-holes are integrally fused, and a heat-resistant electric wire for external extraction. In the thermistor temperature sensor connected to, the lead wire of the thermistor is covered with a metal pipe up to the deepest part of the lead wire hole of the ceramic body, and is sealed by welding at the end portion on the pull-out side of the metal pipe, and at the same time. A thermistor temperature sensor, wherein the thermistor temperature sensor is connected to a conductor of the heat-resistant electric wire and further covered with the metal pipe with an insulator of the heat-resistant electric wire.