JP2742022B2 - Method of manufacturing thermistor element and thermistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thermistor element and a thermistor, and more particularly to a high temperature thermistor for an automobile.

[0002]

2. Description of the Related Art As shown in FIG. 11, a conventional thermistor is connected to a lead wire 10 from one end of a cylindrical thermistor body 101.
2 ・ 102 is projected, or as shown in FIG.
Lead wire 202 from both sides of cylindrical thermistor body 201
It is a projection of 202.

[0003]

Problems to be Solved by the Invention Conventional FIGS. 11 and 12
Thermistor shown in the figure is 1400 for thermistor body 101/201
Since it is sintered at a high temperature of not less than ° C., it burns with a general metal, so platinum is used. Lead wire 102/202
Expensive platinum or the like is used, and the thermistor itself becomes very expensive.

The production of the thermistors as shown in FIGS. 11 and 12 has a problem that the characteristics are varied and the yield is low.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention is to form a thermistor in a tubular shape by using a thermistor material so that the thermistor can be mass-produced inexpensively and mass-produced. One or more insulators
After drawing the sheath containing the porcelain tube and the middle electrode, which is fitted between the sheath and the middle electrode located in the sheath, and reducing the diameter of the sheath to make the porcelain tube into a powder form, and drawing the sheath, the characteristics of the sheath are examined. A method for manufacturing a thermistor element, in which a thermistor element is manufactured by cutting to a required length.

[0006] Further, the present invention provides a thermistor element in which a middle electrode is positioned within a sheath and a thermistor material is filled between the sheath and the middle electrode so that thermistor assembly can be mass-produced. A thermistor having a hollow electrode, a core wire protruding from a MI cable containing a core wire and an inorganic insulator in the cable inside the hollow portion, and a core wire tip and a middle electrode, and a sheath and a cable joined to each other. And

[0007]

According to the present invention, one or more insulator tubes formed of a thermistor material in a cylindrical shape are fitted between a sheath and a middle electrode located in the sheath, and a sheath accommodating the insulator tube and the middle electrode is provided. This is a method for manufacturing a thermistor element in which the diameter of the insulator tube is reduced to a powder by drawing, and after drawing, the sheath is cut to a required length to manufacture a thermistor element. Yield is good, easy to manufacture, suitable for mass production, and inexpensive.

[0008] Further, the present invention provides a method in which a middle electrode is placed in a sheath, a hollow portion of the middle electrode of a thermistor element formed by filling a thermistor material between the sheath and the middle electrode has a core wire and a cable inside. Since the core wire protruding from the MI cable containing the inorganic insulator is internally fitted and the tip of the core wire and the middle electrode, and the sheath and the cable are respectively joined, the thermistor element and the MI cable are connected. The center wire protruding part of the MI cable is fitted inside the hollow part of the middle electrode of the thermistor element, and the tip of the core wire and the middle electrode, the sheath and the cable are respectively joined, so it is excellent in vibration resistance and suitable for mass production and inexpensive Can be provided with a thermistor.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on specific embodiments shown in the accompanying drawings. First, the thermistor element will be described. As shown in FIGS. 1 and 2, a cylindrical inner electrode 2 made of Inconel 600 is arranged in an axial direction in a cylindrical sheath 1 made of Inconel 600, and a sheath 1 is formed.
And the middle electrode 2 are filled with a thermistor material 3.

[0010] As the thermistor material 3, a spinel-based material,
Perovskite, zirconia and SiC can be used. Next, a method for manufacturing a thermistor element will be described. As shown in FIG. 3, the powder of the thermistor material 3 is mixed with an adhesive and solidified. Next, as shown in FIG. 4, the cylinder body 4 is formed by extruding a mixture of the powder of the thermistor material 3 mixed with an adhesive and solidifying the mixture.

Further, as shown in FIG. 5, the cylindrical body 4 is naturally dried. Subsequently, as shown in FIG. 6, firing is performed at about 1250 ° C. to form the insulator tube 5. At this time, the outer diameter 6 of the insulator tube 5 is formed so that it can be fitted inside the sheath 1, and the center hole 7 can be fitted outside the middle electrode 2. Subsequently, as shown in FIG. 7, one or more of the insulator tubes 5 formed as described above are fitted inside the sheath 1 and the center hole 7 is fitted outside the middle electrode 2. Externally fit the required number as needed.

As shown in FIG. 8, drawing is performed.
The outer diameter of the sheath 1 is reduced and the insulator tube 5 in the sheath 1 is crushed,
Powder 8 is formed. Finally, the thermistor element 9 manufactured as described above is cut to a required length L with a required resistance value, as shown in FIG. An arbitrary resistance value can be obtained by this cutting. In this way, mass production becomes possible to manufacture the thermistor element 9.

Next, the thermistor element 9 and the MI cable
The thermistor to which 13 is connected will be described. cable
MI cable containing inorganic insulator 12 such as MgO in 11
The core wire 14 is arranged on the center axis of the cable 13, and the core wire 14 is projected from one end of the MI cable 13. The length of the protruding core wire 14 is made equal to the length of the thermistor element. As shown in FIG. 10, the protruding core wire 14 of the MI cable 13 is inserted into the hollow portion of the middle electrode 2 of the thermistor element, and the tip of the core wire 14 is welded to the middle electrode 2, the sheath 1 and the cable 11 respectively. 16
To join. The joint between the thermistor element 9 and the MI cable 13 is covered with a tip cap 17, and the tip cap 17 is fixed to the MI cable 13 by welding 18.

Thus, the sheath thermistor element 9
And the MI cable 13, the connection is simple, and a thermistor having excellent vibration resistance can be provided at low cost.
In the above example, the case where the middle electrode 2 has a hollow portion has been described, but the middle electrode is not limited to a hollow one and may be a solid one.

[0015]

As described above, according to the present invention, one or a plurality of cylindrical insulator tubes formed of a thermistor material are inserted between a sheath and a middle electrode located in the sheath to form a hollow insulator tube. This is a method of manufacturing a thermistor element in which the sheath containing the electrodes is drawn to reduce the diameter to make the porcelain tube powdery, and the drawn sheath is cut to a required length to manufacture a thermistor element. In addition, the yield can be improved, mass production of thermistor elements becomes possible, and thermistor elements can be provided at low cost.

According to the present invention, as described above, the middle electrode is positioned in the sheath, and the thermistor element is filled with a thermistor material between the sheath and the middle electrode. M containing core wire and inorganic insulator in cable
Since the core wire protruding from the I cable is fitted inside and the tip of the core wire and the middle electrode, and the sheath and the cable are respectively joined, the connection between the thermistor element and the MI cable becomes easy. The mass production of the mrister becomes possible, and the thermistor can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a thermistor element according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a conceptual diagram of a thermistor material powder according to an embodiment of the present invention, which is solidified by mixing an adhesive.

FIG. 4 is a longitudinal sectional view of a cylindrical body formed by extrusion-molding a product obtained by hardening a thermistor material powder mixed with an adhesive.

FIG. 5 is a longitudinal sectional view showing a state where the cylindrical body of FIG. 4 is naturally dried.

FIG. 6 is a longitudinal sectional view of a porcelain tube formed by firing a cylindrical body according to an embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing a state where an insulator tube is inserted between a sheath of a thermistor element and a middle electrode.

FIG. 8 is a longitudinal sectional view of the thermistor element showing a state where the sheath accommodating the insulator tube is drawn to make the insulator tube into a powdery state.

FIG. 9 is a longitudinal sectional view showing a state where a resistance value that requires a thermistor element is cut to a required length L.

FIG. 10 is a longitudinal sectional view showing a state where a thermistor element and an MI cable are connected.

FIG. 11 is a front view of a conventional thermistor element.

FIG. 12 is a front view of a conventional thermistor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sheath 2 ... Middle electrode 3 ... Thermistor material 4 ... Cylindrical body 5 ... Insulator tube 6 ... Outer diameter of insulator tube 7 ... Center hole of insulator tube 8 ... Powder 9 ... Thermistor element 11 ... Cable 12 ... Inorganic insulator 13 ... MI cable 14… Core 15/16… Welding 17… Tip cap 18… Welding

Claims (2)

(57) [Claims] 1. One or more insulator tubes formed of a thermistor material in a cylindrical shape are fitted between a sheath and a middle electrode located in the sheath, and a sheath containing the insulator tube and the middle electrode is drawn. A method for manufacturing a thermistor element, wherein the diameter of the sheath is reduced to powder, and the drawn sheath is cut to a required length to manufacture a thermistor element. 2. A core wire and an inorganic insulator are placed in a cable in a hollow portion of a middle electrode of a thermistor element in which a thermistor material is filled between the sheath and the middle electrode. A thermistor in which a core wire protruding from an accommodated MI cable is fitted inside, and the tip of the core wire and the middle electrode, and the sheath and the cable are respectively joined.