JPS6245148Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sheathed thermocouple temperature sensor, and more specifically, relates to a method of coupling a metal fitting to the sheathed thermocouple for attaching the detector to a temperature measurement site. It is.

Thermocouple temperature detectors are widely used in applications such as industrial furnaces because of their wide range of measuring temperatures and their simplicity. A typical type of thermocouple is a sheath type thermocouple, which protects the hot junction of the thermocouple by covering it with a sheath made of metal, hard glass, ceramic, etc. The conventional one has the structure shown in Figure 1. It is a common item.

FIG. 1 shows a partial cross-sectional view of a conventional sheathed thermocouple temperature sensor. Here, 1 is a sheath into which the hot junction of the thermocouple is inserted, 2 is a covered lead wire, 3 is a flange, 4 is a joint pipe,
5 is a fixing screw. Open end 1b of the sheath
The thermocouple element wire 1c comes out from the wire, and the covered lead wire 2
It is connected to the bare wire portion 2a that protrudes further. The flange 3 is composed of a thick flange portion 3a and a hollow cylindrical portion 3b. The joint pipe 4 has a relatively long hollow cylindrical shape with a stepped part 4a that becomes narrower at one end. And the flange 3a of the flange 3
The above-mentioned thermocouple and lead wire 2 are inserted into the flange 3 and the joint pipe 4 so that the stepped part 4a of the joint pipe 4 is on the distal end 1a side of the sheath 1. The hollow cylindrical portion 3b of the flange 3 and the stepped portion 4a of the joint pipe 4 are connected to the sheath by a caulking method at joint portions 3c and 4b, respectively. On the other hand, the covered lead wire 2 and the joint pipe 4 are mechanically crimped and joined at a crimping part 4d on the opposite side to the stepped part 4a, and the middle part 4c of the joint pipe 4 is connected to the thermocouple wire 1c. and bare wire part 2 of the lead wire
Protects the area around the connection with a. The sheath 1, lead wire 2, flange 3, and joint pipe 4 together constitute a temperature sensor. This detector is further assembled by being inserted through a hollow fixing screw 5, and then screwed into a location where temperature measurement is to be applied. In addition to the above-mentioned caulking method, silver brazing, welding, etc. are also used to join the sheath 1, flange 3, and joint pipe 4.

However, in such a configuration, since the flange 3 and the joint pipe 4 are each independently connected to the sheath 1, if an external force is applied from the flange 3 or the joint pipe 4 side, especially from a direction perpendicular to the sheath 1, In addition, stress tends to concentrate in the intermediate portion 1d between the joint portions 3c and 4b, and the sheath, which is originally designed to be thin and thin, may be damaged.

Further, in such a structure, during manufacturing, for example, during caulking, the load during processing is concentrated on the intermediate portion 1d of the sheath 1, which tends to cause the sheath 1 to break, resulting in a decrease in yield. On the other hand, although processing by silver brazing and welding does not require as much stress as caulking, brazing and welding work on such detailed parts requires extremely high skill and requires high yield and high production. It was quite difficult to realize my sexuality. In addition, the stepped portion 4 is attached to the joint pipe 4 in advance.
Since drawing processing is required, such as providing a,
It was also disadvantageous in terms of cost.

In addition, in order to make it possible to braze, weld, or caulk both the flange and the joint pipe to the sheath as described above, the diameter and wall thickness of the sheath must be increased to a certain extent. , when used as a temperature sensor,
As the heat capacity of the sheath increases, there is also the problem of delayed response.

Therefore, as a result of intensive research in order to solve the problems of the conventional sheath type thermocouple temperature detector as described above, the inventor of the present invention solved the above problems by caulking the sheath and flange, and the flange and the joint pipe respectively. The problem was solved and the present invention was completed.

That is, the gist of the present invention is that in a sheathed thermocouple temperature sensor, a flange for attaching the thermocouple to the temperature measurement site is fixed to the sheath by a mechanical crimping method, and the thermocouple wire and A sheath type thermocouple temperature sensor is provided, characterized in that a joint pipe that covers the connection portion with the lead wire and the mechanically crimped fixing portion is fixed to the flange by a mechanical crimping method.

Next, one embodiment of the present invention will be explained based on the drawings.

FIG. 2 shows a sheath type thermocouple temperature detector according to an embodiment of the present invention. Here, 1 is a sheath into which a hot junction of a thermocouple is inserted, 2 is a covered lead wire, 7 is a metal flange, 8 is a metal joint pipe, and 9 is a fixing screw. As in FIG. 1, two thermocouple wires 1c are inserted from the open end 1b of the sheath.
are protruding from each other, and are connected to the bare wire portions 2a protruding from the covered lead wire 2, respectively.

The flange 7 is attached and fixed to the sheath 1 by caulking. As shown in FIG. 3, the flange 7 is made of a hollow cylindrical body, with a relatively thick hollow disc-shaped flange 7a at one end, and a hollow cylindrical body thinner than the central hollow cylindrical intermediate part 7b at the other end. It has a shaped caulking part 7c. However, the thinning of the caulking part 7c was done in order to avoid the hassle of inserting it into the joint pipe due to burrs caused by hexagonal caulking in that part. The middle part 1 as shown in the flange 10 in Fig. 4
0b and the caulking portion 10c may have the same thickness. Fourth
In the figure, 10a is a flange part, and 10d is a cylindrical hollow part.

The flange 7 and the sheath 1 are fixed by the flange 7.
The sheath 1 is inserted into the cylindrical hollow part 7d so that the front end 1a of the sheath 1 is positioned toward the flange flange 7a, and then the thin crimped part 7c is crimped and crimped. This is done by fixing at the joining part 7f. In this way, an integral sheath 1 and flange 7 is manufactured.

Next, the cylindrical pipe 8 is connected to the open end 1b of the sheath 1.
From the direction, the caulking part 7c and the intermediate part 7b of the flange 7 are covered, and the tip part 8a of the pipe 8 is attached to the flange 7.
Insert the combined sheath 1 and flange 7 into the pipe 8 until it contacts the flange 7a. In this state, the vicinity of the tip portion 8a is caulked, and the caulked joint portion 8b is
By fixing the pipe 8 and the flange 7 together, the pipe 8 and the flange 7 are connected. In this caulking process, since the sheath 1 is already protected by the flange 7, strong caulking is possible and the bonding force is large. Depending on the degree of crimping, a portion 7e of the hollow cylindrical intermediate portion 7b of the flange 7 to which the pipe 8 is crimped may be slightly deformed and come into contact with the sheath 1, as shown in FIG. As a result, the sheath 1, flange 7, and pipe 8 are integrally constructed. Next, thermocouple wire 1
A thermocouple type temperature sensor is constructed by further crimping the pipe 8 using the covered portion of the lead wire connected to c and fixing it at the crimped joint 8d. This detector is further combined with a hollow fixing screw 9 in a form that penetrates it, and is screwed into the temperature measurement application point.
will be used.

As described in detail above, the present invention provides a sheath type thermocouple temperature sensor in which the flange for attaching the thermocouple to the temperature measurement site is fixed to the sheath by mechanical caulking, and the thermocouple wire is The joint pipe, which covers the connection part with the lead wire and the above-mentioned mechanically fastened fixed part, is fixed to the flange using a mechanical fastening method, making assembly and manufacturing easy. It was sufficient to simply cut the parts, which ultimately became advantageous in terms of cost. In addition, since the crimping process is performed at the end of the flange 7 opposite to the flange 7a, the crimping process is performed with a relatively small force, hardly causing any damage to the sheath 1, and increasing the yield. . Moreover, loads such as vibration from the sheath tip side and loads from the covered lead wire side are mainly applied to the coupling pipe 8 and flange 7.
The sheath 1 is not damaged because the sheath 1 is not damaged, and since the crimped joint 8b is strongly crimped as described above, there is no risk of loosening or breaking from this part. There is no.
In addition, since the caulking is mechanically connected, the thermal strain caused by the difference in coefficient of thermal expansion due to the different materials of the sheath 1, flange 7, and pipe 8 can be absorbed by the displacement of the caulked parts. It does not cause damage and can be applied, for example, to a temperature detector in a catalytic converter overheat warning device of an automobile that is subject to large vibrations and thermal shocks. Furthermore, as mentioned above, stress is not concentrated on the sheath 1 itself, and the force required to tighten the flange 7 to the sheath 1 during manufacture is relatively small, so a smaller sheath 1 can be used, and as a result, the sheath 1 can be made smaller. Because the heat capacity of 1 itself is smaller and the caulked part has lower thermal conductivity than welded or brazed parts, it responds more quickly to temperature changes when measuring temperature as a detector, making it more accurate. It can be used as a temperature detector.

[Brief explanation of the drawing]

Figure 1 shows a conventional sheathed thermocouple temperature sensor.
Figure 2 shows an example of the sheathed thermocouple temperature sensor of the present invention, Figure 3 shows a flange used in an example of the present invention, and Figure 4 shows another flange that can be used in the present invention. FIG. 5 is a partially cutaway view showing the contact state between the flange and the sheath. 1... Sheath, 2... Covered lead wire, 3... Flange of conventional product, 4... Joint pipe of conventional product, 5
...Fixing screw, 7, 10...Flange, 8...Coupling pipe, 9...Fixing screw, 7f, 8b...Cerging joint portion.

Claims (1)

[Scope of utility model registration request] In a sheath type thermocouple temperature sensor, the flange for attaching the thermocouple to the temperature measurement site is fixed to the sheath by mechanical caulking, and the connecting part between the thermocouple element wire and the lead wire and the mechanical caulking described above are further fixed to the sheath by mechanical caulking. A sheath type thermocouple temperature sensor, characterized in that a joint pipe covering the fixed portion is fixed to the flange by a mechanical fastening method.