JPS59200933A - Production of temperature measuring resistor - Google Patents

Abstract

PURPOSE:To omit welding and to bring parts close to metallic pipes by fitting a connection ring to the stepped part of one metallic pipe and then fitting the stepped part of one metallic pipe to the stepped part of the other metallic pipe to bring the ring into press contact with the metallic pipes. CONSTITUTION:The connection ring 23 is fitted to the step part 22 of the metallic pipe 21 and then the step part 25 of the metallic pipe 24 is fitted to the step part 22 of the metallic pipe 21. While rotating the metallic pipes 21, 24 and the connection ring 23, pressing is repeated. The connection ring is deformed by the press contact and the gap of the stepped part 22 of the metallic part 21 is filled with the connection ring 23, so that the metallic pipes 21, 24 are adhered and united.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resistance temperature detector that uses a so-called sheath wire in which a resistance element that detects temperature by a change in electrical resistance is inserted into a metal pipe, and in particular, the metal pipe is made to have an extremely small diameter. The present invention relates to a method for manufacturing a temperature measuring resistor that enables the manufacturing process to be performed and improves productivity during manufacturing.

Fig. 1 is a cross-sectional view showing an example of a conventional resistance temperature detector. 1 is a resistance element, which is made by winding a resistance wire 3 such as a platinum wire around a cylindrical winding core 2 made of glass or the like. 0.0025m
Wind the resistance wire 3 of 2 with a wire diameter of about m from one end of the winding core 2 toward the other end, and wind both resistance wires 3 so that a predetermined resistance value is achieved.
The ends of the welded portion 4 are welded to form a welded portion 4 to form a non-inductive winding.

Reference numeral 5 denotes an index line of the resistance wire 3, and 6 indicates a relay wire such as a ribbon wire whose one end is connected to the sunrise wire 5 by welding, which has a larger cross-sectional area than the resistance wire 3. 7 is a support conductor connected to the other end of the relay wire 6 by welding; 8 is a first metal pipe in which the support conductor 7 is housed; Filled. 10 is a second metal pipe, and one end 10a thereof is brought into contact with one end 8a of the first metal pipe 8 to form a welded portion 11 by arc welding or the like. Next, the resistance temperature detector 13 is formed by filling the second metal pipe 1o with the inorganic insulator 9 from the other end 10b and then closing it with the cap 12.

By the way, the conventional resistance temperature detector 13 has the first. In order to join the second metal pipes 8 and 10 by forming a welded part 11 by arc welding, the first. second metal pipes 8, 10,
Alternatively, the support conductor 7 may be melted. To avoid this, first. It is necessary to increase the diameter of the second metal pipes 8 and 10 to increase the distance between them and the support conductor 7, which may increase the shape of the resistance temperature detector 13 or cause defective products due to welding. The disadvantage was that productivity deteriorated.

FIG. 2 is a sectional view showing another example of a conventional resistance temperature detector, in which the same reference numerals as in FIG. 1 indicate the same parts, and 14 is a resistance temperature detector.

Also in this case, in order to facilitate welding between the relay wire 6 and the support conductor 7, the support conductor 7 is connected between the metal pipe 8 and the resistance element 1.
The present invention has been made in order to solve the above-mentioned drawbacks. This invention will be explained below.

FIGS. 3(a) to 3(e) are process diagrams showing one embodiment of the present invention. In these figures, the same reference numerals as in FIG. 1 indicate the same parts.

First, as shown in FIG. 3(a), the first metal pipe 2
A stepped portion 22 is formed on the outer peripheral surface of one end portion 21a of the support pillar 7, and the support conductor 7 is housed in the step part 22, which is filled with an inorganic insulator 9 and then the relay wire 6 of the resistance element 1 is connected to the support conductor 7 by welding. do.

Next, in FIG. 3(b), 23 is a connecting ring fitted to the step 22 of the first metal pipe 21, 24 is a second metal pipe, and the inner peripheral surface of one end 24a is A step portion 25 that fits into the step portion 22 of the first metal pipe 21 is formed.

Next, move the connecting ring 23 in the direction of arrow A to
furthermore, the stepped portion 2'5 of the second metal pipe 24
is moved in the direction of arrow B to remove the stepped portion 2 of the first metal pipe 21.
2 into the state shown in FIG. 3(C).

In FIG. 3(C), 26 is a ram of a compressor (not shown) that presses the connection ring 23, and 27 is a gouer.

Moreover, FIG. 3(d) is a sectional view taken along the line X--X in FIG. 3(c)(7).

Next, the 1. Second metal pipes 21, 24. Connection ring Ji! +41! = 23 in the direction of arrow C in Fig. 3(d), turn the ram 26 in the direction of arrow C.
When the pressure is repeatedly applied in the direction D), the connecting ring 23 deforms due to pressure contact and fills the gap between the stepped portion 22 of the first metal pipe 21. The second metal pipes 21, 24 are bonded and integrated as shown in FIG. 3(e). Thereafter, the inorganic insulator 9 is filled from the other end 24b of the second metal pipe 24, and the cap 28 is closed to complete the resistance temperature detector 29.

It should be noted that the pressure welding of the connecting ring 23 is carried out in an atmosphere of an inert gas such as argon gas in order to prevent oxidation due to exothermic melting.

FIG. 4 is a side sectional view showing another example of the shape of the connecting ring.
1 is a connecting ring having a trapezoidal cross section, and 32 is its tapered surface. Also, 1st. Each step 22.25 of the second metal pipe 21.24 is formed with a chi, <surface 33.34, which corresponds to the tapered surface 32 of the connecting ring 31. Note that illustration of internal resistance elements and the like is omitted. Also, the fourth
The manufacturing method in the case shown is the same as in the case shown in FIGS. 3(a) to 3(e).

In addition, in the above embodiment, 2Il using two pillar conductors 7 is used.
Although the type A type has been described, an appropriate number of three or more pillar conductors 7 can be connected to form a three-wire type or a four-wire type. The resistance element 1 also includes a t±ceramic element. Furthermore, it goes without saying that the connection ring 23 may be formed by forming a round wire or a ribbon wire into an annular shape.

As explained above, the present invention involves inserting a support conductor into a first metal pipe having a step formed on the outer circumferential surface of one end, filling it with an inorganic insulator, winding a resistance wire around the winding core, and wrapping the conductor at both ends. Connect the relay wire of the resistor element with the relay wire connected to the support conductor,
A connecting ring is fitted into the stepped portion of the first metal pipe, and the resistance element is placed on the second metal pipe whose inner circumferential surface at one end is formed into the stepped portion. The steps of the second metal pipe are engaged and connected together by compressing the connecting ring in an inert gas, and the opening of the second metal pipe is filled with an inorganic insulator, and then the lid is closed. Since it is sealed, the metal pipe, internal resistance element, relay wire, support conductor, etc. will not be melted by welding, and these parts can be placed close to each metal pipe, so the outer diameter of each metal pipe can be adjusted. It is much smaller than the conventional one, with a 4-wire type and an outer diameter of 1 mm.
This is an extremely excellent product that can also be manufactured with diameters smaller than φ.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a conventional resistance temperature detector, Fig. 2 is a sectional view showing another example of a conventional resistance temperature sensor, and Fig. 3 is a (
a) to (e) are process diagrams showing one embodiment of the present invention, and FIGS. 3(a) and (b). (c) and (e) are side sectional views, and Figure 3 (d) is Figure 3 (C
), and FIG. 4 is a side sectional view showing a case where a resistance temperature detector is formed using a connecting ring of another shape. In the figure, 1 is a resistance element, 2 is a winding core, 3 is a resistance wire, 4 is a welded part, 5 is a lead wire, 6 is a relay wire, 7 is a column groove body, 9 is an inorganic insulator, 21 is a first Metal pipe, 22 is a stepped portion, 23 is a connecting ring, 24 is a second metal pipe, 25 is a stepped portion, 28
is a cap, and 29 is a resistance temperature sensor. Figure 1 Figure 2 Figure 3 (a) (1)) Figure 3 (c) -X (d) Figure 3 (e) Figure 4 z34

Claims (1)

[Claims] A support conductor is inserted into a first metal pipe having a step formed on the outer peripheral surface of one end, and a relay wire of a resistance element filled with an inorganic insulator is connected to the support conductor by welding,
Next, after fitting a connecting ring to the stepped portion of the first metal pipe, a second metal pipe having a stepped portion formed on the inner circumferential surface of one end is fitted onto the first metal pipe while covering the resistive element. The first metal cap and the second metal pipe are integrated by fitting the step of the second metal pipe into the step of the pipe, and then pressing the connecting ring in an inert gas. A method for manufacturing a resistance temperature detector, comprising: connecting the first metal pipe to the other end of the second metal pipe, and filling the opening with an inorganic insulating material from the other end of the second metal pipe, and then covering the opening with a lid.