JPS5845151B2 - Cylindrical sheathed heater enclosing a metal sheathed thermocouple and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheathed heater in which a metal sheath thermocouple is embedded in the sheath of the sheathed heater, and a method for manufacturing the same.

In this specification, a metal-thick ceramic insulated thermocouple is referred to as a metal-sheath thermocouple.

The sheath of a sheathed heater usually has a thickness of about 1.5 mm and a length of about 500 to 3000 nm.

However, embedding a thermocouple to measure the temperature of the sheath heater in this sheath is necessary for temperature control and safety reasons, but the sheath is thin and the length of the sheath is Because of the long length of the sheath, it was almost impossible to make a small hole for inserting the thermocouple in the sheath parallel to the axis of the sheath.

For this reason, for example, by drilling a hole in a thick-walled sheath at the time of the prototube,
This is done by reducing the diameter and making it to a predetermined thickness by pulling, but it has the drawback that the hole does not pass through properly.

The present invention was conceived in view of the above problem, and an object of the present invention is to provide a sheathed heater in which a metal sheath thermocouple is embedded in the sheath of the sheathed heater, and a method for manufacturing the same.

A feature of the present invention is that the sheath has two layers, an inner layer and an outer layer, and a metal sheath thermocouple is attached between the layers, so that the two layers of sheath and metal sheath thermocouple are closely attached to each other.

Further, a first hollow cylindrical sheath having a predetermined number of grooves having a semicircular cross section provided in parallel along the axis on the outer periphery by an appropriate method;
and a second hollow cylindrical sheath having an inner diameter slightly larger than the outer diameter of the first hollow cylindrical sheath and having grooves having a semicircular cross section equal to the predetermined number provided in parallel along the axis. ,
The first hollow cylindrical sheath is inserted inside the second hollow cylindrical sheath, a substantially cylindrical hole is formed with the grooves of the first and second hollow cylindrical sheaths, and a substantially cylindrical hole is formed in the cylindrical hole. It is characterized by inserting a metal sheath thermocouple and then compressing it to reduce its diameter.

In addition, by doing this, it is possible to insert the metal sheath thermocouple into the sheath of the sheathed heater extremely easily, and by performing diameter reduction compression processing, there is no gap between the metal sheath thermocouple and the sheath of the sheathed heater, and the metal sheath thermocouple is integrated into the sheath of the sheathed heater. You can get a sheathed heater.

Embodiments of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of the sheathed heater of the present invention.

The sheath of the sheathed heater has two layers, and the inner layer is 1-1.
The outer layer is shown as 1-2.

A metal sheath thermocouple 2 is inserted between the inner layer 1-1 and the outer layer 1-2, and the inner and outer layers 1-1 and 1-2 and the metal sheath thermocouple 2 are in close contact with each other. be.

FIGS. 2, 3, and 4 are cross-sectional views for explaining the manufacturing method of the present invention.

As shown in FIG. 2, a grooved hollow cylindrical sheath 3 having a required number of grooves 4 having a semicircular cross section on its outer periphery is prepared.

The radius of the groove 4 is approximately equal to the radius of the metal sheathed thermocouple 2, and the required number is equal to the number of metal sheathed thermocouples required to be inserted into the sheath.

A hollow cylindrical sheath 5 having an inner diameter slightly larger than the outer diameter of the sheath 3 is created.

The inner surface of this sheath has the same number and the same radius as those provided on the outer periphery of the hollow cylindrical sheath 3, and faces oppositely when the hollow cylindrical sheath 3 is inserted into the hollow cylindrical sheath 5. A groove 4 is provided so as to be in the correct position.

As shown in FIG. 4, the hollow cylindrical sheath 3 is inserted into the hollow cylindrical sheath 5, the grooves 4 are opposed to each other to form a substantially cylindrical hole 6, and the metal sheath thermocouple is inserted into the cylindrical hole 6. 2 is inserted, and the hollow cylindrical sheaths 3 and 5 and the metal sheath thermocouple 2 are brought into close contact with each other and formed integrally by performing diameter reduction compression processing.

In this manner, the sheathed heater of the present invention shown in FIG. 1 can be manufactured.

In this case, a drawn hollow cylindrical sheath provided with the grooves described above can also be produced by the method described above.

FIG. 5 shows a partially enlarged view of FIG. 4.

FIG. 6 shows a partially enlarged view after the diameter reduction compression process described above.

In addition, Fig. 7 is an outline drawing of a flat sheath with grooves, and Fig. 8
The figure is a relationship diagram showing the mutual relationship between a metal sheath thermocouple and a groove.

When making a hollow cylindrical sheathed heater in which the metal sheath thermocouple of the present invention is enclosed from a flat plate sheath, the process is as follows.

A required number of grooves 4 having a semicircular cross section are provided on the surfaces of the two flat sheaths 7 and 7'.

The required number is the same as the number of metal sheath thermocouples embedded in the sheath, and the radius of the groove 4 is slightly larger than the radius of the metal sheath thermocouple 2, as shown in FIG.

The width of the flat sheaths 7 and 7' has the same length as the length of the inner diameter of the hollow cylindrical sheath.

As shown in FIGS. 2 and 3, the uneven surface of the flat plate sheath 7, that is, the surface with the grooves, is placed on the outside, and the grooves 4 are aligned in a straight line. Both end surfaces 8 and 9 of the flat plate sheath 7 are welded to form a first hollow cylindrical sheath.

In addition, the uneven surface, that is, the grooved surface of the other flat sheath 7' is placed on the inner surface, and the grooves 4 are aligned in a straight line, and both end surfaces 8' and 2 of the flat sheath 7' are shaped like a hollow cylinder. 9' is welded to form a second hollow cylindrical sheath.

In this case, the outer diameter of the first hollow cylindrical sheath is slightly smaller than the inner diameter of the second hollow cylindrical sheath.

The first hollow cylindrical sheath is placed on the inside and the second hollow cylindrical sheath is placed on the outside to form two layers with a small space between each other, so that each groove 2 forms a substantially cylindrical hole. The grooves of the flat sheath 7' and the grooves of the flat sheath 7 are aligned so that the grooves of the flat sheath 7' are aligned.

A metal sheath thermocouple 2 is inserted into the cylindrical hole.

In this case, there is a gap between the first hollow cylindrical sheath, the second hollow cylindrical sheath, and the metal sheath thermocouple.

Next, the diameter of the second hollow cylindrical sheath is reduced and compressed from the outer diameter side, and as shown in FIG. They disappear, and become closely connected and integrated.

Further, the above diameter-reducing compression process may be performed simultaneously with the compression process performed to solidify the insulating powder of the sheathed heater, or may be performed separately and independently.

According to the present invention, as explained above, a hollow cylindrical sheath enclosing a metal sheath thermocouple is manufactured by a simple method,
A cylindrical sheathed heater containing a metal sheath thermocouple can be manufactured by a conventional method using the hollow cylindrical sheath containing the metal sheath thermocouple.

Further, there is no gap between the sheathed heater and the metal sheathed thermocouple, and the temperature can be measured easily, accurately, and with good responsiveness.

It is also easy to mass produce, and when manufactured from a flat sheath, when stored as a material, the flat sheath requires less storage space and is easy to handle.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the sheath of the present invention, FIGS. 2, 3, and 4 are sectional views explaining the method of manufacturing the sheath of the present invention, and FIG. 5 is a partially enlarged view of FIG. Figure 6 is a partially enlarged view of the sheath after diameter reduction compression processing in Figure 5, Figure 7 is an outline diagram of the flat sheath with grooves, and Figure 8 is a diagram showing the grooves of the metal sheath thermocouple and the flat sheath. FIG. 9 is a perspective view of a sheath manufactured by the force method of the present invention. 1-1... Inner layer of sheath of sheathed heater, 1-2.
... Outer layer of sheath of sheathed heater, 2... Metal sheath thermocouple, 3... Grooved hollow cylindrical sheath, 4...
-Groove, 5...Hollow cylindrical sheath, 6...Cylindrical hole,
7 and 7'... flat sheath.

Claims (1)

[Claims] 1. A hollow cylindrical sheathed heater having a structure in which the sheath is made of two layers, a metal sheath thermocouple is attached between the layers, and the two layers of sheath and metal sheath thermocouple are brought into close contact with each other. A cylindrical sheathed heater with a characteristic metal sheathed thermocouple. 2. A first hollow cylindrical sheath having a predetermined number of grooves with a semicircular cross section provided in parallel along the axis on the outer periphery by an appropriate method, and having an inner diameter slightly larger than the outer diameter of the first hollow cylindrical sheath. A second groove having a semicircular cross section, the same number as the grooves provided in the first hollow cylindrical sheath, is provided on the inner surface in parallel along the axis.
a hollow cylindrical sheath, and inserting the first hollow cylindrical sheath inside the second hollow cylindrical sheath,
A substantially cylindrical hole is formed with the grooves of the first and second hollow cylindrical sheaths, and after a metal sheath thermocouple is inserted into the cylindrical hole, the metal sheath is compressed to reduce its diameter to form an integral piece. A method for manufacturing a cylindrical sheathed heater containing a metal sheathed thermocouple. 3. The metal according to claim 2, characterized in that the first hollow cylindrical sheath and the second hollow cylindrical sheath are made of bowed hollow tubes with grooves formed thereon as an appropriate method. A method for manufacturing a cylindrical sheathed heater containing a sheathed thermocouple. 4 As an appropriate method, a welded hollow cylindrical tube is used in which the first hollow cylindrical sheath and the second hollow cylindrical sheath are formed into a cylindrical shape by forming a grooved flat plate sheath, and welding opposing end surfaces. A method for manufacturing a cylindrical sheathed heater encapsulating a metal sheathed thermocouple according to claim 2.