JPS61296229A - Thermocouple and method for mounting the same - Google Patents

Abstract

PURPOSE:To enable the mounting of a thermocouple and to make it possible to accurately measure the surface temp. of a temp. measuring body, by fixing two thermocouple strands comprising a different kind of metals to a thin plate piece and mounting the thermocouple to the surface of the temp. measuring body. CONSTITUTION:Strands 2, 2 are fixed to the surface of a thin plate piece 1 by spot welding and the cover part 4 of the thermocouple strands are fixed by a metal press jig. In order to use this thermocouple T/C, the thin plate piece 1 is mounted to the surface of a boiler tube by spot welding and, because the thin plate piece 1 is thin, the surface temp. of the boiler tube can be accurately measured at the hot contacts of the leading ends of the thermocouple strands. Further, the thermocouple T/C can be simply formed at a separate place other than the boiler tube on the site. Further, in order to impart no thermal effect to the boiler tube in the mounting of the thermocouple T/C, the thin plate piece 1 is fixed by spot welding or, if necessary, by other fusing means to make it possible to eliminate the point at issue.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermocouple for detecting the surface temperature of a temperature-measuring object, and a method for attaching the thermocouple to the surface of the temperature-measuring object.

Conventional technology Conventionally, as a thermocouple for measuring the temperature on the surface of a temperature-measuring object, a metal-coated thermocouple a is embedded in a metal heat transfer plate b, for example, a metal plate of about 3 mm in thickness, as shown in Fig. 5. , thermocouples with hot junctions formed thereon were attached to the surface of the temperature-measuring object by electric or gas welding. Thermocouples could be used and installed only when the metal was durable and could withstand welding, or when the metal was in a state where it could be welded, but in other cases it could not be used.

(2) Since the volume of the thermometer itself is large, it is smaller than the temperature detector, and in the case of a thin metal temperature detector, the surface temperature cannot be accurately detected.

■Producing a temperature sensor requires sophisticated and precise work such as precise welding and X-ray inspection that cannot be performed on site due to its structure, making it impossible to manufacture the temperature sensor on site.

■Furthermore, when attaching a temperature measuring element, high temperature welding is performed to the temperature measuring element, so it may affect the temperature measuring element thermally and require precise dimensional accuracy, it may have a small volume, or it may have a large wall thickness. Cannot be installed on thin objects.

It had various drawbacks.

Problems to be Solved by the Invention The present invention has been made in order to solve the above-mentioned problems.The present invention has been made in order to solve the above-mentioned problems. In addition, if the temperature-measuring object is a metal device, the temperature-measuring element can be easily attached to the surface even if water or oil is inside, making it possible to perform high-temperature welding work. There is no fatigue in the metal due to thermal distortion or sudden temperature gradients, and there is no decrease in mechanical strength or functional deterioration of the temperature sensing element itself due to thermal effects, ensuring high temperature measurement accuracy. We are trying to provide what we can.

Means for Solving the Problems The present invention solves the problems of the prior art and achieves the above object by forming two thermocouple wires made of different metals used as thermocouples into thin plate pieces. The aim is to achieve this purpose with a thermocouple completed by fixing the thermocouple to the thermocouple. The two thermocouple wires here are two different metal wires that have been used in the past, and the thin plate pieces are made of various metal materials. These thermocouple wires can be fixed to a thin plate by welding to only one surface, or by inserting the ends of the wires into two through holes formed in the thickness direction of the thin plate. A type in which the tip of the strand is inserted into the surface of the thin plate from one side to the other and fixed in a state where it is exposed or close to the surface is adopted.

Function The present invention is a thermocouple in which two thermocouple wires made of different metals are fixed to a thin plate piece, so the thin plate piece of the thermocouple can be attached to a metal device or a tube as the object to be measured. It can be attached to the surface of the body, etc. by a method such as welding, or in places where such methods cannot be used, it can be bound or glued with other materials to the surface of the body to be measured. It is to be installed by Since the thermocouple is constructed by fixing the thermocouple wire to the thin plate, for example, the thermocouple wire is welded to the thin plate at the construction site, and then the thin plate is welded by spot welding or other appropriate methods. The temperature on the surface of the object to be measured can be easily and accurately measured by simply attaching the strip to the surface of the object to be measured, and it can be easily installed without causing any thermal effects on the object to be measured. can.

First Embodiment The thermocouple and its mounting method according to the present invention will be explained based on the first embodiment shown in FIGS. 1 and 2.
The thermocouple of the first embodiment of the present invention shown in the figure is, for example, as shown in the figure, the surface of a 0.8 mm thick nickel thin plate l is coated with glass wool, and the tip of the thermocouple wire is 2,
The thermocouple wire 2 is made bare by removing the covering portion thereof, and is fixed to the surface of the thin plate piece 1 by spot welding or the like, and the covering portion 4 of the thermocouple element wire is fixed with a presser metal fitting 3. To use this thermocouple T/C, as shown in FIG. 2, for example, the nickel thin plate piece 1 is attached to the surface of the boiler tube 5, in which water is present, by spot welding.
Since this thin plate piece 1 is thin, it is possible to accurately measure the temperature on the surface of the boiler tube 5 at the hot junction at the tip of the thermocouple wire, and it is also easy to manufacture a thermocouple as shown in Figure 1 on site. In addition, it can be made in a separate location from the boiler tube 5, and when installing it, spot welding or other welding if necessary is required to avoid thermal effects on the boiler tube 5. The thin plate piece 1 can be attached to the boiler tube 5 by fixing it by other means or the like without problems caused by the influence of heat over time. In this example, a nickel plate was used as the thin plate piece 1, but even if the thin plate piece 1 is made of a metal other than nickel, it may be made of various metals depending on the place and purpose of use. is adopted as appropriate, and its thickness is also adjusted.

However, since this thin plate piece 1 constitutes a temperature sensing element, it is preferable to use a material with high thermal conductivity, and in the case of spot welding, etc., it is preferable to use the same material as the temperature sensing element. Needless to say, this is preferable.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

The present thermocouple disclosed in this figure has two parallel grooves 6 formed in a thin plate piece 1, and holes 7, 7 that penetrate in the thickness direction at the tips of the grooves 6, 6, that is, in the central part of the thin plate piece 1. is formed, and two thermocouple wires are placed inside the groove 6 and hole 7. That is, with the covering part 4 of a part of the tip of the coated thermocouple wire 2 removed, this wire is embedded in two non-conducting wires 6, 6, and two holes 7 are inserted through the tip wire 2 itself in the thickness direction. The thermocouple wire 2 and the thin plate piece 1 are fixed to each other with the tip of the wire 2 exposed to the other surface of the thin plate piece 1 and fixed to the surface of the thin plate piece 1 by welding or the like. It is something that To use this thermocouple, as shown in Fig. 4, if the thin plate piece 1 is fixed to the surface of the object to be measured by spot welding, etc., the hot junction of the thermocouple wire will be connected to the surface of the object to be measured. Since the thermocouple T/C can be installed in a state where it is in direct contact with the thermocouple, it is natural to eliminate the thermal influence when attaching the thermocouple T/C to the surface of the object to be measured, as in the first embodiment.
Furthermore, in addition to this, a hot junction exists in direct contact with the surface of the object to be measured, thereby making it possible to accurately measure the temperature.

Effects of the Invention As described above, the thermocouple and its attachment method according to the present invention are made by fixing two thermocouple wires made of different metals to a thin plate piece, and also attaching the thermocouple to the surface of the object to be measured. Thermocouples can be attached by attaching them using a fixing method such as spot welding, so thermocouples can be easily installed on-site, and the material and By selecting the appropriate thickness and fixing it to one surface, or inserting the wire into a hole made through the thin plate piece and fixing it to the other surface, it is possible to accurately pack the surface of the object to be measured. In addition to being able to easily manufacture a thermocouple that enables temperature measurement, it is also possible to provide a thermocouple that can be easily attached by eliminating the thermal influence when attaching the nuclear thermocouple to the surface of a temperature-measuring object.

[Brief explanation of drawings]

FIG. 1 is a perspective view for explaining the first embodiment of the thermocouple according to the present invention, FIG. 2 is an explanatory diagram of the first embodiment attached to the surface of the object to be measured, and FIG. 3 is the second embodiment. FIG. 4 is an explanatory cross-sectional view of the second embodiment attached to the surface of a temperature-measuring object, and FIG. 5 is an explanatory perspective view showing a conventional thermocouple. 1: Thin plate piece, 2: Wire, 3: Holder, 4: Coating, 5: Boiler tube, 6: Groove, 7: Hole, T/C: Thermocouple patent applicant Mitsubishi Heavy Industries, Ltd. 1113 Figure 85 Figure 4 Figure 1 Figure 2

Claims (4)

[Claims] (1) A thermocouple characterized by having two thermocouple wires made of different metals fixed to a thin plate piece. (2) The thermocouple according to claim 1, wherein the thermocouple is fixed to the surface of a thin plate piece. (3) The ends of two thermocouple wires made of different metals are inserted into two through holes arranged side by side in the thickness direction of the thin plate piece and fixed to the thin plate piece. Thermocouple according to item 1. (4) A method for attaching a thermocouple, which comprises fixing two thermocouple wires made of different metals to the surface of a temperature-measuring object with a thin metal plate interposed therebetween.