JPS5937709Y2 - RTD element - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a temperature measuring resistance element.

Conventional resistance temperature detectors include the one shown in Figure 1, in which an inorganic insulating powder such as magnesia is filled between a metal outer tube a and conductors I and B' to insulate the outer wire D. The lead wire f of the resistance temperature detector e is connected to the conductive wire bs b'.
At the same time as connecting f'i gsg', an end pipe fitting is joined to the metal outer tube a, and an inorganic insulating powder c'? After filling, the open end is closed with gold.

In addition, there is also a conventional product as shown in Fig. 2, in which an inorganic insulating powder such as magnesia is filled between a metal outer tube a and four conductive wires b%b', b〃, b'''. A resistance temperature detector ef is housed in an end pipe connected to the outer tube a, and a pair of lead wires f, f' of the resistance temperature detector wire in the resistor e is a pair of purple conducting wires b.
, b″′, and the other pair of conducting wires,
b' so that the resistance temperature detector e'fc is clamped,
The end tube is filled with inorganic insulating powder c' and gold, and a pair of conducting wires bbb' are electrically connected to the end tube's purple-closed metal lid i.

However, since powder is used for inorganic insulating materials, it is difficult to achieve close packing, especially when the metal outer tube a, end tubes are thin, or the internal structure is complicated as shown in Figure 2, so the packing density is low. is extremely low, and some parts may not be filled at all, and the larger the porosity (residual air) of the powder, the lower the thermal conductivity.

In addition, when inorganic insulating powder gold is tightly packed, a vibrating metal is applied to measure the amount of tight packing, so the fixed position of the resistance temperature sensor e tends to be offset from the center of the tube, causing the assembled temperature measurement Resistance elements have poor responsiveness to temperature, resulting in variations in quality from product to product, and are often prone to poor insulation.

Further, although the metal outer tube a and the end tube are joined by welding means, there is a drawback that joining becomes difficult when the outer diameter and wall thickness of both tubes a and h become thinner.

Therefore, the present invention is an attempt to eliminate the above-mentioned six drawbacks, and will be described in detail based on an embodiment illustrated in FIG. ', 2//
, 2///, an inorganic insulating powder 3 such as magnesia is densely filled and an exterior wire 4 is formed into a metal shape, and an end tube 5 is abutted against one end of the metal tube 5 in the shape of a congruent shaft. , are joined by welding means or the like at the joining part 6, and a 7-karat gold current measuring resistor is housed in both pipes 5. However, in the present invention, before joining the metal outer pipe 1 and the end pipe 5, The tube 5 is filled with an inorganic fired body 8 made of magnesia or the like, so that the inorganic fired body 8 protrudes from the base end of the end tube 5, and this protruding end 8ae is fitted into the end of the metal outer tube 1. and the end tube 5 has the above-mentioned protruding end 8ak.
As described above, it is welded to the metal outer tube 1 as a guide.

Here, as shown in FIGS. 4A and 4B, the inorganic fired body 8 is packed tightly into the end tube 5 and the metal outer tube 1.
A gap 9 is formed between the current measuring resistor 7 and the inner hole 8b of the fired inorganic body 8, which is formed into a cylindrical shape with an outer diameter set to a cylindrical shape. to the above conductor 2
．． 2' and 2'' extend into the inner space 10 of the end tube 5 as shown in FIG. In the space 10, the lead wires 11, 11', . The empty space is tightly filled with inorganic insulating powder such as magnesia, inorganic fired material, or inorganic insulating material such as inorganic adhesive, and the open end 5ak of the end tube 5 is closed with a metal lid 14 or welded overlay. It can be constructed by

In addition, as shown in FIGS. 4B and 5, the inorganic fired body 8 has an inner hole 8b (r) of a size corresponding to the outer diameter of the current-measuring resistor 7 so that it can be inserted tightly. At the same time, a plurality of concave grooves 15, 15', 15/15' are formed on the peripheral wall of the inner hole 8b.
/, 15''' can also be provided in the axial direction.

By molding the inorganic fired body 8 in this way, it is possible to arrange the current measuring resistor 7ff more accurately and densely in the center of the end tube 5, and the conductor wires 2.2', 2〃, 2''' The lid wires 11.11 are passed through the gold recesses 15.15', 15//, 15'' and extended into the space 10 of the end tube 5.
Since it is possible to connect 13, 13... with
The inorganic insulating material 12 also becomes easier to pack more closely.

In addition, the current-measuring resistor 7 has a current-measuring resistance wire wound between a mica core body (not shown) and a mica exterior body, and is composed of a regular gold metal frame outside the mica exterior body. Things can be stored in the field.

As explained above, according to the temperature measuring resistance element according to the present invention, the metal outer tube 1 and the plurality of conductive wires 2, 2', 2〃, 2'''
An end tube 5 is coaxially joined to one end of the armored wire 4 which is filled with inorganic insulating powder such as magnesia between the . The plurality of conductive wires are passed through metal fittings between the current measuring resistor 7 having an interior σ, and the inorganic fired body 8 made of magnesia or the like, which is disposed internally from the metal outer tube 1 to the end tube 5. The above current measuring resistor 7
The inner space of the fifth end tube, which is connected to the lid wires 11 and 11' and whose open end is closed, is densely filled with an inorganic insulating material 124 such as inorganic insulating powder such as magnesia, fired body, inorganic adhesive, etc. Therefore, the current measuring resistor 7 can be accurately and easily positioned at the center of the gold end tube 5, and the inorganic fired body 8 can be replaced with conventional inorganic insulating powder, which is difficult to fill in small details. Since this has been replaced, the inner space 10 of the end tube 5 can also be filled with insulating materials such as inorganic fired bodies or inorganic adhesives instead of inorganic insulating powder, which can be easily packed tightly. Because of this, the pore density of the insulating material can be easily measured and the thermal conductivity can be improved, thereby contributing to the improvement of responsiveness.Furthermore, the current measuring resistor 7 is fixed with an inorganic fired body 8. Therefore, movement due to vibration can be prevented, and therefore, a metal with excellent durability can be provided.Furthermore, when the protruding end 8ak of the inorganic fired body 8 is fitted into the metal outer tube 1 and the end tube 5 is placed coaxially with the metal Since the outer tube 1 and the end tube 5 can be joined with metal 6, even if the metal outer tube 1 and the end tube 5 have small diameters and are thin, the joining of both tubes 1 and 5 can be easily and reliably performed. assembly can be made easier.

[Brief explanation of drawings]

FIGS. 1 and 2 are longitudinal sectional side views showing the conventional swamp resistance element, FIG. 3 is a longitudinal sectional side view of the swamp resistance element according to the present invention, and FIG. FIG. 4B is an enlarged cross-sectional view of the embodiment shown in the same manner as FIG. 4A, and FIG. FIG. 2 is a perspective view of an example gold stone. 1...Metal outer tube 2, 2/, 2//,
2///,... Conductor wire, 3... Inorganic insulating powder, 4... Exterior wire, 5... End tube, 6.
...Junction, 7... Current measuring resistor, 8...
...Inorganic fired body, 8b...Inner hole, 10.
...Inner tube of end tube, 11, 11' ... Lead wire of resistance temperature detector, 12 ... Inorganic insulating material, 1
5, 15', 15〃, 5'ku... Concave grooves in the inorganic fired body.

Claims (3)

[Scope of utility model registration request] (1) An end tube is coaxially joined to one end of the outer wire, which is made by filling an inorganic insulating powder such as magnesia between a metal outer tube and multiple conductor wires, and the axial center position of the end tube is The plurality of conductive wires are passed between the temperature-measuring resistor housed in the temperature-measuring resistor and the inorganic fired body made of magnesia, etc., housed from the metal outer tube to the end tube. In the internal cavity of the end tube, which is connected to the lead wire of the body and whose open end is closed, inorganic insulating powder such as magnesha, etc.
A temperature-measuring resistance element formed by densely filling inorganic insulating metal such as a fired body and an inorganic adhesive. (2) The temperature measuring resistance element according to claim 1, wherein the inorganic fired body is formed in a cylindrical shape. (3) The inorganic fired body is provided in a cylindrical shape, and each conductive wire is conducted through a plurality of grooves formed in the axial direction on the inner hole wall of the utility model registration claim. The temperature measuring resistance element according to item 1.