JP2021068610A - Micro heater, manufacturing method of micro heater, and micro heater sheath cable used for the manufacturing method - Google Patents

Abstract

To provide a micro heater which is capable of maintaining excellent workability by preventing a protrusion which causes catching at the time of routing from being formed on an outer surface of an intermediate part of a metal sheath, capable of efficiently providing at low cost various combinations of a heating part and a non-heating part of different lengths and easily confirming whether the length of the heating part/non-heating part is a preset length and further, of which the reliability is improved by preventing a burden from being applied to a connection part of a heating wire and a non-heating wire.SOLUTION: A heating wire 3 and a non-heating wire 4 are disposed in parallel while being spaced from each other over a full length inside of a metal sheath 2 excluding a boundary region R1 between a heating part 11 and a non-heating part 12. In the boundary region R1, non-heating wires 4 (4A and 4B) are cut. A boundary-side end 40 of the cut non-heating wire 4A extending closer to the non-heating part 12 between the cut non-heating wires 4A and 4B is connected to at least the heating wire 3 (3B) extending closer to the heating part 11 by welding, etc.SELECTED DRAWING: Figure 1

Description

The present invention relates to a microheater in which a heating wire and a non-heating wire are housed in a metal sheath and a heat-resistant insulating material is filled in a gap to form a heating portion and a non-heating portion along the axial direction.

In this type of microheater, for example, a heating wire and a non-heating wire are connected in advance, the connected wire is housed in a metal sheath, the gap is filled with a heat-resistant insulating material, and then die drawing or aging is performed. Some are manufactured with a reduced diameter (see, for example, Patent Document 1). In such a microheater, the region where the heating wire exists inside the outer peripheral surface of the metal sheath becomes the heat generating portion, and the region where the non-heating wire exists becomes the non-heating portion.

The heat-generating portion is a portion that is arranged on the heating target to heat the heating target, and the non-heating portion is a portion for crawling a place other than the heating target and further for providing a terminal portion. Therefore, the lengths of the heat-generating portion and the non-heating portion are variously combined depending on the type of the heating target, the position where the heating target is installed, the position on the device main body side to which the terminal portion is connected, and the like. Is required. It would be costly and time consuming to manufacture such many microheaters with different dimensions from scratch as described above after adjusting the lengths of the heating wire and the non-heating wire. In addition, since the connection between the heating wire and the non-heating wire moves in the axial direction due to die drawing or aging, it is difficult to check whether the length is as set, and the connection is burdened during the processing process. There is a problem that it takes.

On the other hand, a sheath cable for a heat generating part in which a heating wire is stored in a metal sheath and a heat-resistant insulating material is filled in the gap, and a non-heating wire is stored in the metal sheath and the gap is filled with a heat-resistant insulating material. It has also been proposed to provide a sheath cable for the non-heating part, cut it to the required length, connect the heating wire and the non-heating wire, and connect the metal sheaths with a connecting sleeve to make a microheater. (See, for example, Patent Document 2). However, such a connecting sleeve becomes a protruding portion protruding from the outer surface of the metal sheath, which causes a catch when the microheater is routed and installed on the heating target, and there is a problem that the usability is deteriorated. In addition, it is necessary to pressurize and reduce the diameter of the connecting sleeve so that the heat-resistant insulating material to be filled in the connecting sleeve is brought into close contact with the connecting sleeve. ..

JP-A-2019-114445 JP-A-2007-220325

Therefore, in view of the above-mentioned situation, the present invention tries to solve the problem by not forming a protruding portion on the outer surface of the intermediate portion of the metal sheath, which causes catching during routing, and can maintain good workability. It is possible to efficiently provide various combinations of different lengths of the heat-generating part and the non-heating part at low cost, and it is easy whether the length of the heat-generating part / non-heating part is as set. Furthermore, it is possible to provide a highly reliable microheater and a method for manufacturing the same without imposing a burden on the connection portion between the heating wire and the non-heating wire.

The present invention includes the following inventions.
(1) A microheater in which a heating wire and a non-heating wire are housed in a metal sheath and a heat-resistant insulating material is filled in a gap, and a heating portion and a non-heating portion are formed along the axial direction. Except for the boundary region between the heat generating portion and the non-heating portion, the heating wire and the non-heating wire are arranged in parallel with each other at intervals over the entire length, and in the boundary region, the non-heating wire is arranged. Is cut in the middle, and the end of the cut non-heating wire extending toward the non-heating portion side of the cut non-heating wire extends at least toward the heating portion side. A microheater characterized in that it is connected to the heating wire.

(2) In the boundary region, the heating wire is also cut in the middle, and the end portion on the boundary side of the non-heating wire extends to the heating portion side of the cut heating wire. The microheater according to (1), which is connected to the end of the cut boundary side.

(3) In the boundary region of the metal sheath, sealing holes for the connection work are provided at positions equidistant from both the heating wire and the non-heating wire (1) or (1) or ( 2) The microheater described.

(4) A microheater in which a heating wire and a non-heating wire are housed in a metal sheath and a heat-resistant insulating material is filled in a gap to form a heating portion and a non-heating portion along the axial direction. In the manufacturing method, a heating wire and a non-heating wire are arranged in parallel with each other at intervals over the entire length in a metal sheath, and a sheath cable filled with the heat-resistant insulating material is provided in a gap, and the sheath cable is provided. By making a working hole in the peripheral wall of the metal sheath at a predetermined position along the axial direction and working through the hole, the non-heating wire is cut and one of the cut non-heating wires is cut. The end of the non-heating wire on the cutting side is connected to the heating wire extending to at least the side where the other non-heating wire is present, whereby the region where the hole is present is set as the boundary region and is more than this. A method for manufacturing a microheater, characterized in that the non-heating portion is formed on the side where one of the non-heating wires is present, and the heating portion is formed on the side where the other non-heating wire is present.

(5) By working through the hole, the non-heating wire is cut and the heating wire is also cut, and the end of the one non-heating wire on the cutting side is the other of the cut heating wires. It is connected to the end of the cutting side of the heating wire that extends to the side where the non-heating wire exists, so that the region where the hole also exists is set as the boundary region, and one of the non-heating wires is present. The method for manufacturing a microheater according to (4), wherein the non-heating portion is formed on the side where the heat is generated, and the heat generating portion is formed on the side where the other non-heating wire exists.

(6) The method for manufacturing a microheater according to (4) or (5), wherein the holes are provided at positions equidistant from both the heating wire and the non-heating wire.

(7) A sheath cable used in the method for manufacturing a microheater according to any one of (4) to (6), in which a heating wire and a non-heating wire are parallel to each other with a distance from each other over the entire length in the metal sheath. A sheath cable for a microheater that is placed and the gap is filled with heat-resistant insulating material.

According to the present invention as described above, the metal sheaths are not connected to each other by the connecting sleeve, and the heating wire and the non-heating wire arranged in parallel to each other inside the metal sheath are the boundary between the heating portion and the non-heating portion. Since the structure is cut and connected in the region, a protruding portion that causes catching at the time of routing is not formed on the outer surface of the intermediate portion of the metal sheath, and good workability is maintained.

Further, such cutting / connection can be easily processed by making a hole in the peripheral wall portion of the metal sheath to remove the insulating material, and the heating wire and the non-heating wire are spaced apart from each other over the entire length. If the sheath cables arranged in parallel with each other are prepared, various combinations of different lengths of the heat generating portion and the non-heating portion can be provided efficiently and at low cost according to the user's request. It can be easily confirmed at the backfilling position of the hole whether the length of the heat generating part / non-heating part is as set. Further, die drawing, aging, compression diameter processing, etc. are not required, the burden on the connecting portion between the heating wire and the non-heating wire can be avoided, and a highly reliable microheater can be provided.

(A) is a vertical sectional view showing a microheater according to a typical embodiment of the present invention, and (b) is a horizontal sectional view of a boundary region. (A) is a vertical sectional view showing a sheath cable for a microheater used for manufacturing the microheater of the present invention, and (b) is a horizontal sectional view. The explanatory view which also shows the manufacturing procedure of a microheater. Similarly, a vertical cross-sectional view showing a modified example of the microheater. The explanatory view which shows the manufacturing procedure of the microheater of the same modification example. The cross-sectional view which shows the modification of the microheater which provided a plurality of pairs of heating wire and non-heating wire.

Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the microheater 1 of the present invention, as shown in FIG. 1, the heating wire 3 (3A, 3B) and the non-heating wire 4 (4A, 4B) are housed in the metal sheath 2, and the heat-resistant insulating material 5 is provided. The gap is filled, and a region of the heat generating portion 11 and a region of the non-heating portion 12 are formed along the axial direction. Similar to the conventional case, the heat generating portion 11 is a portion arranged on the heating target to heat the heating target, and the non-heating portion 12 is a portion for crawling a place other than the heating target, and a terminal portion is provided at the end thereof. It is a part for.

In particular, in the present invention, the heating wire 3 and the non-heating wire 4 are arranged in parallel inside the metal sheath 2 at intervals over the entire length, except for the boundary region R1 between the heating portion 11 and the non-heating portion 12. In the boundary region R1, the non-heating wire 4 is cut in the middle, and the non-heating wire 4A extending to the non-heating portion 12 side of the cut non-heating wires 4A and 4B is cut. The end portion 40 on the boundary side is connected to at least the heating wire 3 (3B) extending to the heating portion 11 side by welding or the like.

More specifically, in the boundary region R1, the heating wire 3 is also cut in the middle, and the end portion 40 on the boundary side of the non-heating wire 4A extends to the heating portion 11 side of the cut heating wire 3. It is connected to the cut boundary side end 30 of the heating wire 3B by welding or the like. Reference numeral 70 indicates a connection portion formed by welding or the like. The boundary region R1 is provided with a sealing hole 6 for the connection work at a position equidistant from both the heating wire 3 and the non-heating wire 4.

The sealing hole 6 is a hole formed for performing operations such as forming the non-heating wire 4 in the boundary region R1 in a cut state, connecting to the heating wire 3B, and the like, and is heat-resistant insulating as described later. It is a hole in which the material 5 is removed, cutting and connecting work is performed, the heat-resistant insulating material is backfilled, and the hole is welded and sealed with metal or the like. In this example, non-heating portions 12 are formed on both ends of the heat generating portion 11 via the boundary region R1, and such a microheater 1 is such that the non-heating portion 12 on one end side does not generate heat. By energizing the wire 4A, the heating wire 3B of the heat generating portion 11, and the non-heating wire 4A of the non-heating portion 12 on the other end side, only the heating portion 11 can be made to generate heat.

As each material of the metal sheath 2, the heating wire 3, the non-heating wire 4, and the heat-resistant insulating material 5, the same materials as those conventionally known can be used. For example, the heating wire 11 has a large electric resistance value. Nichrome wire or the like that generates Joule heat by energization is preferable, and nickel, copper or the like having a small electric resistance value is suitable for the non-heating wire 12.

Next, the manufacturing procedure of the microheater 1 of the present embodiment will be described with reference to FIGS. 2 and 3.

First, as shown in FIG. 2, the sheath cable 10 in which the heating wire 3 and the non-heating wire 4 are arranged in parallel with each other at intervals over the entire length in the metal sheath 2, and the gap is filled with the heat-resistant insulating material 5. Is provided. Next, as shown in FIGS. 3A and 3B, a working hole 6 is formed in the peripheral wall of the metal sheath 2 at a predetermined position along the axial direction of the sheath cable 10 (for example, drilling a hole). Processing), the heat-resistant insulating material 5 immediately below the hole is removed through the hole 6 to expose the heating wire 3 and the non-heating wire 4.

The holes 6 are preferably provided at positions equidistant from both the heating wire 3 and the non-heating wire 4 in terms of work efficiency. Next, as shown in FIG. 3C, the heating wire 3 and the non-heating wire 4 are cut at predetermined positions through the hole 6. Reference numerals 32 and 42 indicate cut portions.

Then, as shown in FIGS. 3D and 3E, the end 40 on the cut side of one of the cut non-heating lines 4A is the side where the other non-heating line 4B exists. The heat-resistant insulating material 5 is backfilled and the hole 6 is metal-sealed by welding or the like by connecting to the end 30 on the cutting side of the cut heating wire 3B extending to the above. As a result, the region where the hole 6 exists is set as the boundary region R1, and the non-heating portion 12 is formed on the side where the one non-heating wire 4A exists and the other side where the non-heating wire 4B exists. That is, the heat generating portion 11 is formed on the side where the heating wire 3B exists.

In the above typical embodiment, in the boundary region R1, both the non-heating wire 4 and the heating wire 3 are cut off in the middle, and the end portion 40 on the boundary side of the non-heating wire 4A is on the heating portion 11 side of the heating wire 3. Although the heating wire 3B extending to the above-mentioned end 30 on the boundary side of the cut edge is connected by welding or the like, another example of the present invention is as shown in FIG.
Similarly, in the boundary region R1, only the non-heating wire 4 is cut in the middle, and the end portion 40 on the boundary side of the non-heating wire 4A may be connected to the intermediate portion 31 of the heating wire 3 by welding or the like.

FIG. 5 shows the manufacturing procedure of this modified example, but the difference from the manufacturing procedure of the above-mentioned typical embodiment is that only the non-heating wire 4 is operated from the hole 6 as shown in FIG. 5 (c). The point where the heating wire 3 is cut (cut portion 42) and the heating wire 3 is not cut, and the end portion 40 of the cut non-heating wire 4A is connected to the intermediate portion 31 of the heating wire 3 by welding or the like as shown in FIG. 5 (d). The only point is that the others are the same.

The microheater 1A according to this modification also has a form in which non-heating portions 12 are formed on both ends of the heating portion 11 via the boundary region R1. Then, the non-heating wire 4A of the non-heating portion 12 on one end side, the heating wire 3 of the heating portion 11 (the region between the boundary regions R1 of the heating wires 3), and the non-heating wire 4A of the non-heating portion 12 on the other end side. By energizing the unit, only the heat generating portion 11 can be made to generate heat.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.
For example, in the above embodiment, one heating wire 3 and one non-heating wire 4 are provided, and the same as the conventional single-core type microheater, which can be used as a double-terminal type is illustrated. Is not limited to this, as shown in FIG. 6, a plurality of heating wires 3 are provided in parallel, and a non-heating wire 4 paired with each heating wire 3 is also provided, and both ends are provided in the same manner as the conventional multi-core type microheater. Of course, it can also be configured so that it can be used as a child type / single terminal type (the one shown in the figure can be used in the same way as the conventional two-core type).

1,1A Microheater 2 Metal sheath 3, 3A, 3B Heat-generating wire 4, 4A, 4B Non-heating wire 5 Heat-resistant insulating material 6 holes 10 Sheath cable 11 Heat-generating part 12 Non-heating part 30 End part 31 Midway part 32 Cutting part 40 End 42 Cut 70 Connection

Claims (7)

A microheater in which a heating wire and a non-heating wire are housed in a metal sheath and a heat-resistant insulating material is filled in a gap to form a heating portion and a non-heating portion along the axial direction.
Except for the boundary region between the heat generating portion and the non-heating portion, the heating wire and the non-heating portion are arranged in parallel with each other at intervals over the entire length.
In the boundary region, the non-heating wire is cut in the middle, and the end of the cut non-heating wire extending to the non-heating portion side on the cut boundary side is A microheater characterized by being connected to at least the heating wire extending to the heating portion side. In the boundary region, the heating wire is also cut in the middle, and the end portion of the non-heating wire on the boundary side is the cutting of the heating wire extending toward the heating portion side of the cut heating wire. The microheater according to claim 1, which is connected to an end on the boundary side. The micro according to claim 1 or 2, wherein a sealing hole for the connection work is provided in the boundary region of the metal sheath at a position equidistant from both the heating wire and the non-heating wire. heater. A method for manufacturing a microheater in which a heating wire and a non-heating wire are housed in a metal sheath and a heat-resistant insulating material is filled in a gap to form a heating portion and a non-heating portion along the axial direction. There,
A heating wire and a non-heating wire are arranged in parallel in the metal sheath at intervals over the entire length, and a sheath cable filled with the heat-resistant insulating material is provided in the gap.
A working hole is made in the peripheral wall of the metal sheath at a predetermined position along the axial direction of the sheath cable.
By working through the hole, the non-heating wire is cut in the middle and at the same time.
The end of one of the cut non-heating wires on the cut side is connected to the heating wire extending to at least the side where the other non-heating wire exists.
As a result, the non-heating portion is formed on the side where the one non-heating wire exists, and the heating portion is formed on the side where the other non-heating wire exists, with the region where the hole exists as the boundary region. A method for manufacturing a microheater, which comprises forming a microheater. By working through the hole, the non-heating wire is cut and the heating wire is also cut.
The end of the one non-heating wire on the cutting side is connected to the end of the cut heating wire on the cutting side extending to the side where the other non-heating wire exists.
As a result, the non-heating portion is formed on the side where the one non-heating wire exists, and the heat generation is generated on the side where the other non-heating wire exists, with the region where the hole exists as the boundary region. The method for manufacturing a microheater according to claim 4, wherein a portion is formed. The method for manufacturing a microheater according to claim 4 or 5, wherein the holes are provided at positions equidistant from both the heating wire and the non-heating wire. A sheath cable used in the method for manufacturing a microheater according to any one of claims 4 to 6.
A sheath cable for a microheater in which heating wires and non-heating wires are arranged in parallel with each other at intervals over the entire length in a metal sheath, and the gap is filled with a heat-resistant insulating material.

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