JP2515067Y2 - Thermistor temperature sensor - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermistor temperature sensor, and more particularly to a thermistor temperature sensor used for detecting the temperature of a heating portion of a stove, a gas range, an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, negative thermistors used for temperature detection have been 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,
Reference numeral 7a is a conductor of the heat-resistant electric wire 7, 7b is a heat-resistant insulator, 7c is a jacket insulator, 8 is a connecting portion between the lead wire 3 and 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, the thermistor element 2 having silver or silver-palladium alloy thick film electrodes on both sides uses a Dumet wire formed by coating an iron-nickel alloy wire with a copper tube. A pair of lead wires 3
There is used a glass-sealed thermistor in which one end is connected and the whole excluding a part of the lead wire 3 is fused and sealed by a glass-sealed body 4.

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 7a of the heat resistant electric wire 7 by welding at a connecting portion 8. It constitutes a thermistor temperature sensor.

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

[0007]

[Problems to be Solved by the Invention] When the temperature of the heat generating part of a stove, a gas range, an automobile or the like is abnormal, or when the temperature is temporarily raised, the ambient temperature becomes higher, so that the heat resistance is higher. What is reliable is required.

The conventional thermistor temperature sensor is 300 ° C.
With respect to the above temperature change, there is a problem in the heat resistance of the insulating tube that electrically insulates the lead wires of the thermistor, and the insulating tube deteriorates and cracks occur. Further, the surface of the lead wire is oxidized and the copper layer is peeled off due to vibration or the like.

The silicon grease filled in the above-mentioned metal protection tube is decomposed by the silicone oil and hardened to cause cracks.

Therefore, there is a problem that the fragments of the copper layer separated from the lead wires of the thermistor temperature sensor move between the lead wires due to vibration, and the degree of electrical insulation between the lead wires is reduced, resulting in lack of stability.

The present invention is intended to solve the above problems of the prior art and prevents the influence of the peeling of the copper layer of the lead wire, and is a highly reliable thermistor excellent in heat resistance and mechanical strength. It is intended to provide a temperature sensor.

[0012]

In the thermistor temperature sensor of the present invention, 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 are fused together. In the thermistor temperature sensor in which the externally drawn heat-resistant wire is connected to the thermistor that is attached, the lead wire of the thermistor is covered with a metal pipe to the deepest part of the lead wire hole of the ceramic body, and at the end of the lead side of the metal pipe. It is formed by sealing by welding and at the same time being connected to the conductor of the heat-resistant electric wire, and further covering the metal pipe with the insulation of the heat-resistant electric wire.

[0013]

According to the above construction, the lead wire pulled out from the glass sealing body and the metal pipe covering and protecting the lead wire are completely insulated from each other inside the ceramic body, and the copper layer on the surface of the lead wire is provided. Since the part is not exposed to the outside, the degree of insulation does not decrease 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 insulator of the heat resistant electric 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 electric characteristics.

[0017]

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

One ends of the thermistor element 2 and the lead wire 3 are
It is adhered with a conductive paint containing silver or the like and baked and connected when the glass sealing body 4 is sealed. At the same time, the glass sealing body 4
And a ceramic body 5 made of fine ceramics having two lead wire through holes, tempered glass or the like, which are fused and integrated with each other.

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 innermost 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, the heat-resistant insulator 7b.
The outer insulation 7c braided with glass fiber on
It is composed of silicon varnish.

The lead wire 3 sealed at the end of the metal pipe 6 on the lead-out side is connected to the metal pipe 6 and the conductor 7a of the heat resistant electric wire 7 at the same time by welding at the connecting portion 8, and further outside the heat resistant electric wire 7. The insulated pipe 7c covers the metal pipe 6 to form a thermistor temperature sensor.

[0022]

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. Since it has high heat resistance, it can be used at high temperature. Also, by coating the lead wire with a metal pipe, the mechanical strength is excellent, and by covering the metal pipe with the insulation of the heat resistant electric 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)

(57) [Scope of utility model registration request] 1. A thermistor element, 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 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 of the metal pipe on the pull-out side, and at the same time. A thermistor temperature sensor, wherein the thermistor temperature sensor is connected to the conductor of the heat-resistant electric wire, and the metal pipe is further covered with an insulator of the heat-resistant electric wire.