JPS5880884A - Thermocouple - Google Patents

Abstract

PURPOSE:To obtain a thermocouple capable of being readily inserted at the end to the tip of a guide tube even when the bore of the tip of the tube is drawn narrowly. CONSTITUTION:A stopper 4 which is expanded in the bore of one end side is fixed to the outer periphery of a sheathed thermocouple 1. Two pairs of opposing cutouts 5, 6 are formed at one end side of the stopper 4, a member between the cutouts 5 and 6 is bent in an outer circumferential direction as a stopper body 7, which is not operated as a stopper in the inserting direction of the thermocouple and which is operates at the end as a stopper in contact between the coils of the coil sheath. The coil spring 3 and the sheathed thermocouple 1 are engaged via the body 7, and the end of the thermocouple is projected slightly from the end of the sheath 3. The end of the thermocouple 1 thus constructed is inserted to the tip which is drawn at a guide tube 8, and the end of the sheath 3 is stopped immediately before the part which is drawn narrowly at the tube 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheathed thermocouple having a coil sheath around its outer periphery.

Thermocouples for measuring the temperature of the floor of the reactor vessel room, etc., are guided from the insertion operation room to the reactor vessel*iii in order to facilitate replacement in the event that the initially installed thermocouple breaks down or breaks. A tube is provided in advance and inserted into the guide tube.

However, the guide tubular shape is not straight but curved. This makes it difficult to insert the thermocouple into the guide tube.

Therefore, the authors have already proposed a thermocouple in which a coil sheath 2 is attached to the outer periphery of a sheathed thermocouple, the tip of which is attached to the sheath I/cl1 of a sheathed thermocouple, as shown in Figure 1.

Inserting this coil sheath thermocouple into the guide tube is extremely harmful.

On the other hand, whether the tip of the thermocouple touches the object to be measured or
Correct temperature detection is difficult unless the device is located within the target atmosphere.

In the above example, it is desirable that the space between the thermocouple and the guide tube be as small as possible at the tip of the guide tube.

Therefore, the inner diameter of the tip of the guide tube is reduced.

The present invention provides a thermocouple that can be inserted JIK even when the inner diameter of the guide tube tip is narrowed and narrowed as described above, and the thermocouple tip can be inserted at the guide tube tip ICT. The purpose is to

The present invention will be explained below with reference to examples.

FIG. 2 is a side view of one embodiment of the present invention.

In FIG. 2, 1 is a sheathed thermocouple, and 3 is a coil sheath wrapped around the outer periphery of the sheathed thermocouple.

A stopper 4 having an enlarged inner diameter at one end as shown in FIG. 3 is fixed to the outer periphery of the sheathed thermocouple l.

Two pairs of opposing notches 5 and 6 are provided at one end of the stopper 4, and the member between the notches 5 and 6 is curved toward the outer circumference of the stopper body 7, as shown in FIG. As shown, the stopper body 7 does not act as a stopper in the insertion direction of the sheath thermocouple, and acts as a stopper in the withdrawal direction of the sheath thermocouple pair because the tip of the stopper body 7 comes into contact between each coil of the coil sheath 3. It is configured to work.

Further, the coil spring 3 and the sheath thermocouple 1 are locked by the stopper body 7, and the tip of the sheath thermocouple 1 protrudes slightly from the tip of the coil sheath 3, as shown in FIG. 2, and is worn out.

The sheathed thermocouple 1 constructed as described above is inserted into the guide tube 11 whose distal end is constricted.

In this case, the sheath thermocouple 1 and the coil sheath 3 are inserted integrally, and are inserted smoothly even into the curved portion of the guide tube 8, as in the case of the conventional sheath thermocouple 1 and coil sheath 2 described above. .

As the insertion progresses and the tip of the sheath thermocouple 1 reaches the constricted portion Kt at the tip of the guide tube 8, a pressing force is applied only to the sheath thermocouple 1.

Therefore, only the sheath thermocouple 1 is inserted regardless of the presence of the stopper 4, and the tip of the sheath thermocouple 1 is inserted into the guide tube 8.
The distal end of the sheath 3 stops just before the constricted part of the guide tube 8.

Pushing in only the sheath thermocouple 1 is easy because the sheath thermocouple 1 moves inside the coil sheath 3, and also because the stopper 4 is provided.

There is no possibility that the sheathed thermocouple 1 will come back.

Therefore, as shown in FIG. 5, the tip of the sheathed thermocouple 1 is inserted up to the tip of the guide tube 8.

In this state, the tip of the sheathed thermocouple 1 is connected to the guide tube 8.
It reaches the tip of the sheath thermocouple 1 and the kite tube 8.
There is a small gap between the inner diameter of the tip and the temperature can be detected accurately.

Also, by slightly raising the tip of the guide tube 8, the guide vt
Even if the guide tube 8 is installed so as to reduce the convection of linearly heated gas in the space between the sheathed thermocouple 1 and the sheathed thermocouple 1, the sheathed thermocouple 1 can be easily inserted.

As explained above, according to the present invention, a coil sheath is sheathed on the outside of a sheathed thermocouple, and one or more sheathed thermocouples serving as one-way stoppers are fixed between the sheathed thermocouple and the coil sheath, thereby reducing the inner diameter of the tip. The sheathed thermocouple can be easily inserted into the guide tube that has been processed into a small size, and the tip of the sheathed thermocouple can be easily inserted into the tip of the guide tube.

[Brief explanation of the drawing]

FIGS. 1a and 1b are partial cross-sectional views of a conventional thermocouple. FIG. 2 is a partial sectional view of a thermocouple according to an embodiment of the present invention. FIG. 3 is a perspective view of a stopper used in one embodiment of the present invention. FIG. 4 is an enlarged view of an important part of an embodiment of the present invention. FIG. 5 is a partial cross-sectional view showing a state in which a thermocouple according to an embodiment of the present invention is inserted into a guide tube. 1... Sheath heat (vs. s) 3... Coil sheath. 4... Stopper, 8... Guide tube. Inventor Yasuo Takeichi Applicant Daido Sangyo Co., Ltd. Representative Hatao Takeichi/m a Office 2g 399 −

Claims (2)

[Claims] (1) A sheath thermocouple, a coil sheath covered with a skeleton sheath thermocouple, and a coil sheath that is solidly layered on the outer periphery of the sheath thermocouple and contacts the coil sheath only when the sheath thermocouple moves in one direction. A thermocouple comprising a stopper that locks a sheath thermocouple and a coil sheath. (2) The stopper is a cylindrical body into which the sheathed thermocouple is inserted, which is fixed to the sheathed thermocouple at one end, has a plurality of pairs of notches at the other end, and has the member between the notches expanded outward. Claim IIIE1
Thermocouples listed in section.