JPH10241845A - Coupling structure for sheath heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupling structure for sheath heater that need not to take the non-heat generating part long on the edge when plural sheath heaters are coupled, and make the size of the device to be compact. SOLUTION: When plural sheath heater 2 are coupled, the coupling sections are constructed as to be sealed by flexible tube. By doing so, the seal materials which are required conventionally become unnecessary, and it makes unnecessary to restrict the temperature of the edge of the sheath heater 2 below 300 deg.C, and also it become possible to make the length of non-heat generating part small, and to make the device size compact, and to use the sheath heater 2 for high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a sheathed heater integrally manufactured by compressing a high insulating powder and a heating element into a metal pipe.

[0002]

2. Description of the Related Art Conventionally, in a sheathed heater, a heating tube such as a nichrome wire is inserted into a hollow tube of stainless steel or the like, an insulating material such as magnesium oxide is filled in the hollow tube, and the end of the hollow tube is sealed with glass or the like. Things. The reason why the end of the hollow tube is sealed in this way is that magnesium oxide or the like as an insulating material generally has a hygroscopic property, and the insulating property is impaired by the moisture absorption. However, the heat resistance of glass seals is usually 3
Since there is a limit such as 00 ° C. or less, care is taken to keep the ends of the sheathed heater from becoming hot.

When two or more sheathed heaters are connected and used in a zigzag manner, as described above, the non-heat generating portion must be extended so that the ends of the sheathed heater do not become hot. Ingenuity such as installation was made.

[0004]

The connection structure of the conventional sheathed heater as described above has the following problems. That is, when connecting a plurality of sheathed heaters, it is necessary to take a long non-heat generating portion at the end, so that there has been a problem that the size of the device becomes large and the device cannot be made compact. In recent years, the heat generation temperature of the sheathed heater has also been increasing, and the above-mentioned problems have become more remarkable.

The present invention solves the problems of the conventional structure for connecting sheathed heaters described above. Even when a plurality of sheathed heaters are connected, it is not necessary to take a long non-heat-generating portion at the end, and the size of the device is reduced. It is an object of the present invention to provide a sheathed heater connection structure that can be made compact.

[0006]

In order to solve the above-mentioned problems, the invention according to the first aspect has a plurality of sheathed heaters, one end of which is connected to each other by a conductive wire, and the same power supply. The gist is that a heating element configured to generate heat in a circuit covers an insulator surrounding a conductive wire connecting the ends, and at the same time, a cover member that seals between the connected ends is provided. I do. Therefore, since the ends of the connected sheathed heaters are sealed, there is no concern that the insulating property of the insulating material is impaired without moisture being mixed in from the outside.

According to a second aspect of the present invention, in the first aspect, the cover member is a flexible tube made of a heat-resistant metal. Therefore, when connecting and using a plurality of the sheathed heaters, the sheathed heaters can be connected in any shape such as a zigzag shape or a U-shape as well as a linear shape.

According to a third aspect of the present invention, in the first aspect, the cover member is a heat-resistant metal half-pipe. Therefore, when a plurality of sheathed heaters are connected and used, if a half-split pipe of an arbitrary shape is prepared in advance, it can be connected in a free shape in a zigzag or U-shape as well as in a straight line. can do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a perspective view of a heating body in which a sheathed heater according to the present invention is connected in two upper and lower stages. FIG. 2 is a sectional view showing the internal structure of the sheathed heater. FIG. 3 is a cross-sectional view showing an internal structure when a conventional sheathed heater is connected in two upper and lower stages. FIG. 4 is a perspective view of a cover member according to the present invention, in which (a) shows a flexible tube, and (b) and (c) show half-split pipes.

[0010] As shown in FIG.
Metal pipe 1A, insulating material 1B, sealing material 1C at both ends,
The heating wire 4 includes a heating wire 4 as a heating element, and the heating wire 4 is composed of a heating portion H of a high-density portion wound tightly and a non-heating portion L of a straight portion that hardly generates heat. The glass material used as the sealing material 1C has a heat resistant temperature of 300.
° C, the temperature near the sealing material at both ends is 300
It was necessary to be below ° C. Therefore, the heating portion H of the heating wire 4 is short, and the non-heating portion L is long. The connecting portion of the two sheathed heaters is connected by a conductive wire 8, and the conductive wire 8 is covered with an insulator 7.

As shown in FIGS. 1 and 2, at the joint between the sheathed heater 1 and the sheathed heater 2 to which the present invention is applied, a cover member 6 for covering an insulator 7 covering the conductive wire 8 is connected to both ends. Because it is configured to seal between the parts, no moisture is mixed in from the outside, and the insulating property of the insulating material 1B is not impaired at the connecting part without using a sealing material. , The end temperature of the connection
It may be 0 ° C. or higher. Therefore, when the connection structure of the present invention is employed, a high-temperature sheathed heater can be employed, and the non-heating portion L at the end of the sheathed heater of the connection portion can be reduced, so that the device size is reduced and the device is compact. Can be

The heating element 3 shown in FIG. 1 has a sheathed heater 1 and a sheathed heater 2 connected in two vertical stages, and is formed by processing a material having good heat transfer such as a copper alloy or an aluminum alloy. It is a thing. The two sheathed heaters are electrically connected in series, and are connected to a power supply 5 by a connection line 4a. Power supply side ends 1a, 2 of each sheathed heater
In a, the length of the non-heating portion L is set to be long, and the temperature near the sealing material 1c is set to 300 ° C. or less.

The cover member 6 shown in FIG. 2 is a flexible tube made of a heat-resistant metal. After the sheathed heater 1 and the sheathed heater 2 are connected linearly, the tube is inserted from the outside and the sheathed heater is formed. After being brazed to the ends or adhered by welding or the like, they can be bent so as to have a two-tiered configuration. With the above configuration, the connected sheathed heater can easily correspond to various shapes such as a linear shape, a zigzag shape, and a U-shape. In the present invention, SUS-316L is used as the flexible tube and SUS-316L is also used as the metal pipe of the sheathed heater. However, other materials, for example, titanium and the like can be used, so the material is not limited.

Instead of the above-described flexible tube, a half-split pipe shown in FIG. 4B or 4C may be used. When using the half-split pipe,
It is clear that if a half-split pipe of any shape is prepared in advance, it can correspond to each shape such as a straight shape, a zigzag shape, and a U-shape. Since the dimensional accuracy is required, a connection structure using the flexible tube is also desirable.

[0015]

As described above, according to the present invention,
When connecting a plurality of sheathed heaters, the connecting portion is configured to be sealed with a flexible tube, so that a conventionally required sealing material is unnecessary, and the temperature of the end of the sheathed heater is set to 300 ° C. The length of the non-heat-generating portion can be reduced, and the size of the device can be reduced and a high-temperature sheathed heater can be used.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heating body in which a sheathed heater according to the present invention is connected in two upper and lower stages.

FIG. 2 is a sectional view showing an internal structure of the sheathed heater.

FIG. 3 is a cross-sectional view showing an internal structure when a conventional sheathed heater is connected in two upper and lower stages.

FIG. 4 is a perspective view of a cover member according to the present invention,
(A) is a flexible tube, (b) and (c) show a half-split pipe.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheath heater 2 sheath heater 3 heating element 4 heating wire 5 power supply 6 cover member 7 insulator 8 conductive wire

Claims (3)

[Claims] 1. A conductive element having a plurality of sheathed heaters, one end of which is connected to each other by a conductive wire, and which is configured to generate heat by the same power supply circuit. A sheathed heater connection structure, characterized in that a cover member for covering an insulator surrounding the wire and for sealing between the connected ends is provided. 2. The connection structure for a sheathed heater according to claim 1, wherein the cover member is a flexible tube made of a heat-resistant metal. 3. The sheathed heater connection structure according to claim 1, wherein the cover member is a heat-resistant metal half-split pipe.