JP2019114445A - Micro heater with non-heating part - Google Patents

Abstract

To solve the problem in which, in a micro heater having a non-heating part, a decrease in a diameter of a wire produced at a butt-welding portion with a heating wire of a non-heating wire sometimes causes disconnection at a time of use, and to provide a micro heater having a non-heating part without a decrease in a diameter of the non-heating wire.SOLUTION: In a micro heater 1 having a non-heating part in which a heating wire 6 of nichrome and a non-heating wire 7 of copper are accommodated by interposing an inorganic insulating material powder 12 in a metal sheath tube 5, by providing a metal connecting pipe 8 at a connection part between the heating wire 6 and the non-heating wire 7, a structure does not require butt-welding of the heating wire 6 and the non-heating wire 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a microheater having a non-heat generating portion among microheaters in which an inorganic insulating material powder is interposed in a metal sheath and a heating wire generating Joule heat by energization is accommodated.

  The micro-heater is a flexible heater in which an inorganic insulating material powder is interposed in a metal sheath tube and a heating wire generating Joule heat when energized is accommodated. The basic structure is shown in FIGS. 6 and 7. There are two types. FIG. 6 is a cross-sectional view showing a basic and general first configuration of a conventional micro heater, and FIG. 7 is a cross-sectional view showing a basic and second configuration of the conventional micro heater.

  6 (a) and 7 (a) are cross-sectional views in the longitudinal direction, and FIGS. 6 (b) and 7 (b) are cross-sectional views taken along the line E-E of FIG. 6 (a), and FIG. It is a figure of the FF cross section of. However, the terminal sleeve 9 and the insulation coatings 13 and 15 of the lead wires 80 and 81 for supplying electricity are drawn in external form, and for easy viewing, FIGS. 6 (b) and 7 (b) are shown in FIG. a) is drawn at a larger scale than FIG.

  In the microheater 10 shown in FIG. 6, the heating wire 6 is accommodated in the metal sheath tube 5 with the inorganic insulating material powder 12 interposed, and the end sleeve 9 is provided at both ends thereof. The conductors 14 and 16 exposed from the insulation coatings 13 and 15 of the lead wires 80 and 81 are connected thereto. In the metal outer frame of the end sleeve 9, the end of the heating wire 6 and the ends of the conductors 14, 16 are connected, and moisture does not infiltrate the inorganic insulating material powder 12 to prevent the insulation resistance from decreasing. A seal is provided.

  The micro heater 20 shown in FIG. 7 differs from the micro heater 10 in FIG. 6 in that the reciprocating heating wire 6 is accommodated in the metal sheath tube 5 with the inorganic insulating material powder 12 interposed, and therefore the end sleeve 9 Is provided only on one side. The role of the end sleeve 9 is the same as that of the end sleeve 9 in FIG. 6, and the ends of the heating wire 6 and the ends of the conductors 14 and 16 exposed from the insulation coatings 13 and 15 of the lead wires 80 and 81 in the metal outer frame , And a seal is provided so that moisture does not infiltrate the inorganic insulating material powder 12 and the insulation resistance is not reduced.

  As a material of the heating wire 6 of the microheaters 10 and 20 of FIG. 6 and FIG. 7, nichrome having a large electric resistance and a large heating value is used except for a special exception. Further, the specific structure of the inside of the end sleeve 9 is typically as shown in FIG. 1 of Patent Document 1. As shown in the figure, the end of the heating wire (22) and the conductor (13) of the lead wire in the metal outer frame (11) interpose an insulating material (14, 17). The seal is housed in the outer frame (code 11), and a seal (code 15) is provided at the end of the metal outer frame (code 11). In each end sleeve 9 in the structure of FIG. 6, one heating wire (code 22) and one conductor (code 13) in FIG. 1 of Patent Document 1 are provided. Here, the reference numerals in parentheses are the reference numerals shown in FIG. 1 of Patent Document 1.

  When the object to be heated and the end seal are separated, for example, when the object to be heated is in the container, the end sleeve 9 of FIGS. 6 and 7 is usually placed outside the container, and the heating wire 6 and the inorganic insulating material powder are separated. A metal sheath 5 containing 12 is laid in the container to the object to be heated. In this case, in the microheaters 10 and 20 of FIGS. 6 and 7 where the heating wire 6 is provided over the entire length in the metal sheath tube 5, the parts not requiring heating are also heated, and the microheaters 10 and 20 are unnecessary. Power consumption, and other problems such as damage to the device by heating the device in the container having a low heat-resistant temperature other than the heating target.

  In order to avoid such an adverse effect when the object to be heated is separated from the end seal, conventionally, only the portion to be heated in contact with the object to be heated generates heat, and the other portion does not generate heat as shown in FIG. In many cases, the micro heaters 11 and 21 shown in 9 are used. FIG. 8 is a cross-sectional view showing a basic first configuration of a conventional microheater having a non-heat generation portion, and FIG. 9 is a cross-sectional view showing a basic second configuration of a conventional microheater having a non-heat generation portion FIGS. 8 and 9 show the outer sheaths 13 and 15 of the end sleeve 9 and the lead wires 80 and 81 in the same manner as in FIGS.

  While the heating wire 6 made of nichrome, which has a high electrical resistivity, in the microheaters 10 and 20 of FIGS. 6 and 7 generates heat over the entire length, the microheaters 11 and 21 of FIGS. A heat generating portion containing a heat generating wire 6 made of nichrome wire, a non-heat generating portion containing a non-heat generating wire 7 made of copper having a small amount of heat generation due to a small electrical resistivity, and an alloy of nichrome and copper It can be divided into an intermediate heating portion in which the portion 19 is present. The same components as those of the microheaters 10 and 20 of FIGS. 6 and 7 except that the non-heating wire 7 and the alloy portion 19 are present, and the same components are shown in FIGS. .

  In the micro-heaters 11 and 21 of FIGS. 8 and 9, by setting only the portion to be heated in contact with the heating object as the heat generating portion, unnecessary power consumption is suppressed, and damage to the device due to unnecessary heating is avoided. be able to.

  The portion shown in FIGS. 6 to 9 in which the metal sheath tube 5 has the inorganic insulating material powder 12 interposed and a metal wire such as the heating wire 6 or the non-heating wire 7 is accommodated is often referred to as a microheater cable. Hereinafter, the micro heater cable refers to this part. As shown in FIGS. 7 and 8 of Patent Document 2, a micro-heater cable is first made thicker than the finished diameter, and the diameter is reduced by die drawing or swaging to make a predetermined diameter shown in FIG. 6 of the same document. Finished in diameter micro heater cable.

  In the micro-heaters with non-heat generating parts shown in FIGS. 8 and 9, the metal wires accommodated when making a micro cable thicker than the finished diameter before diameter reduction are at both ends of the heating wire 6 thicker than the finished diameter made of nichrome. The non-heating wire 7 made of copper of substantially the same diameter is butt welded.

  In the butt welding of the heating wire 6 and the non-heating wire 7, an alloy portion of nichrome which is the material of the heating wire 6 and copper of the material of the non-heating wire 7 inevitably occurs, and this alloy portion is stretched after diameter reduction The alloy portion 19 is formed, and the portion where the portion is present becomes an intermediate heat generation portion having an intermediate resistance between nichrome and copper.

  In addition, even if it is a copper wire, generation | occurrence | production of Joule heat is not zero. Since the calorific value per unit length is proportional to the square of the applied current and the resistance value per unit length, the calorific value per unit length of two types of connected wires through which the same current flows is per unit length Proportional to the resistance value of If the two types of wires have the same diameter, the resistance per unit length is proportional to the electrical resistivity, and the calorific value per unit length is proportional to the electrical resistivity. In the non-heat generation part of FIGS. 8 and 9, since the electrical resistivity of copper is about 1.6% of nichrome, the calorific value per unit length is about 1 of the calorific value per unit length of the calorific part. It is .6%. As described above, even in the non-heating wire and the non-heating portion, heat is generated although it is smaller than the heating wire and the heating portion. Also in the following, a heating wire and a wire and a portion whose heat generation is smaller than that of the heating portion are respectively referred to as a non-heating wire and a non-heating portion.

JP, 2010-257582, A JP, 2017-112079, A

  As well known, welding of dissimilar metals is difficult. As mentioned above, in the conventional microheater having a non-heat generation portion shown in FIGS. 8 and 9, it is necessary to butt weld before the diameter reduction of the heat generation wire 6 made of nichrome and the non-heat generation wire 7 made of copper. is there.

  In this butt-welded portion, a bulge of the alloy portion 19 and a recess 22 of the non-heating wire 7 often occur as shown in FIG. 10 (b). The cause of this is that the melting point of copper is lower than that of nichrome, and the thermal conductivity of copper is high. During butt welding, copper melts extensively before it is raised to the melting point of nichrome, and copper melted by surface tension Still move to the solid nichrome side, and after welding, the non-heat-generating wire 7 side of the alloy portion 19 swells around the entire circumference, ie, the shape shown in FIG. It is considered that a recess 23 is formed on the entire periphery near the boundary, and when this is reduced to the finished diameter, the swelling of the alloy portion 19 and the recess 22 of the non-heating line 7 in FIG.

  Since the thermal expansion coefficient of the nichrome heating wire 6 and copper non-heating wire 7 is different from the thermal expansion coefficient of the inorganic insulating material powder 12 and the metal sheath tube 5, the heating wire 6 and non-heating wire 7 when using the microheater There is tension and compressive stress on the surface. This stress is particularly large at the time of temperature rise when the temperature difference with the metal sheath tube 5 becomes large, and at the time of temperature decrease, and when temperature rise and fall is repeated, a break occurs at a location where the diameter is narrowed by the recess 22 of the copper non-heating wire 7 There has been a problem with the conventional non-heated portion micro-heater that a problem may occur. If the temperature of the welded portion is not sufficiently raised to eliminate the depression, the conduction between the heating wire 6 and the non-heating wire 7 becomes insufficient, and the temperature of this portion rises excessively at the time of use due to the presence of contact resistance. As a result, another problem of disconnection due to evaporation of the heating wire 6 and the non-heating wire 7 occurs.

  A nickel-based alloy wire having an intermediate thermal conductivity or melting point between copper and nichrome, as a countermeasure for the problem that the diameter may be reduced due to the depression 22 of the non-heating wire 7 and disconnection may occur during use In some cases, a copper-based alloy wire or a wire in which copper is clad with nickel may be used as a relay wire of the heating wire and the non-heating wire. In this case, the short relay wire is butt-welded to the heating wire made of nichrome, and the non-heating wire of copper is butt-welded to the relay wire, so the depression of the non-heating wire is reduced. However, the depression does not disappear at all, and the problem of disconnection can not be completely solved. Moreover, in this method, the electrical resistivity of the relay wire is usually an intermediate value between nichrome and copper, so the relay wire becomes the intermediate heat generation portion shown in FIGS. 8 and 9 and the intermediate heat generation portion becomes long. A problem arises. When the intermediate heating portion becomes longer, unnecessary power consumption in this portion is increased, and there is an additional problem that the possibility of heating a portion not to be heated is increased.

  The present invention has been made in view of the problem of disconnection caused by the depression of the non-heating wire caused by welding of dissimilar metals in a conventional micro-heater having the non-heating region, and the non-heating portion has no recess in the non-heating line. It aims at providing a certain micro heater.

(First aspect)
The micro-heater with non-heating part according to the invention is
With a metal sheath,
A heating wire housed in a metal sheath tube and made of nichrome and generating Joule heat by energization;
A non-heating wire which is housed in a metal sheath and made of copper and has substantially the same diameter as the heating wire,
A connecting pipe housed in a metal sheath tube and made of metal and having an inner diameter substantially the same as the heating wire and the non-heating wire;
Inorganic insulating material powder filled between the metal sheath tube and the heating wire, the non-heating wire, and the joining tube,
One end of the heating wire and one end of the non-heating wire are in contact with each other in the joining pipe and conducted, and only the end of the heating wire in contact with the non-heating wire and the end of the non-heating wire at least in contact with the heating wire In the connecting tube, the inner surface of the connecting tube is in contact with the heating wire inside and the outer surface of the non-heating wire, and the portion where the non-heating wire exists is outside the connecting tube of the heating wire It is characterized in that it is a non-heat generating portion with a smaller amount of heat generation.

  As described above, in the manufacture of the microheater cable, a cable thicker than the finished diameter is first made, and the diameter is reduced by die drawing or swaging to obtain a microheater cable of a predetermined diameter. In microheaters without non-heat generation parts, the diameter reduction ratio is reduced to make a long micro heater cable, and this is cut to produce a large number of micro heaters while microheaters with non-heat generation parts In this case, since the position of the heat generating part is different depending on the place of use, and since the heat generating part and the non-heat generating part are present, it is impossible to cut a long micro heater cable to manufacture a large number of micro heaters. Usually, the diameter reduction ratio is about one half to one third.

  The diameter reduction ratio in the fabrication of the microheater cable having the non-heat generation portion according to the present invention is also about 1/2 to 1/3, but the heating wire before the diameter reduction, the non-heating wire and the connecting tube A state in which one end is in contact with one end of the heating wire and one end of the non-heating wire having substantially the same diameter, and an end portion in contact with the non-heating wire of the heating wire in an inside diameter connecting tube where the heating wire and the non-heating wire can be inserted And by at least temporarily welding the end of the non-heating wire in contact with the heating wire inside the connecting tube, the diameter of the connecting tube is reduced by the external force at the time of diameter reduction, and the heating wire is reduced. A state in which the end of the heating wire in contact with the non-heating wire and at least the end in contact with the heating wire of the non-heating wire are in the connecting pipe in a state in which the one end of the heating wire is in contact with the one end. Also, before the diameter reduction between the inner surface of the connecting pipe and the outer surface of the heating wire and the non-heating wire, It is also fixed in tight contact with reduced diameter as were gaps.

  Since the heating wire before reduction in diameter, non-heating wire and connecting pipe may be temporarily fixed welding, spot welding can be used, and temperature rise until the entire cross section becomes completely molten as in the prior art is unnecessary, etc. Therefore, no depression occurs in the non-heating wire as in the conventional microheater having a non-heating portion, and no depression occurs in the heating wire and the connecting tube. Therefore, there is no concern that disconnection may occur due to the depression of the non-heating line as in the conventional micro heater having the non-heating part.

  In addition, even if the contact between the heating wire and the non-heating wire is insufficient and the contact resistance remains, the inner surface of the joining tube is in close contact with the heating wire and the surface of the non-heating wire in the tube. Even if it flows, there is no excessive temperature rise there.

  As described above, the calorific value per unit length is proportional to the resistance per unit length. The resistance value of the portion where the non-heating wire exists in the joining tube is the resistance value in which the resistance of the non-heating wire and the joining tube is connected in parallel, so the resistance value per unit length is the non-heating wire outside the joining tube Less than resistance per unit length. This indicates that the portion having the non-heating line in the joining pipe belongs to the non-heating part, and the calorific value per unit length is smaller than that of the non-heating line outside the joining pipe.

  On the other hand, since the resistance value of the portion where the heating wire exists in the joining tube is the resistance value in which the resistance of the heating wire and the joining tube is connected in parallel, the resistance value per unit length is the resistance value of the heating wire outside the joining tube. It is smaller than the resistance per unit length, and usually larger than the resistance per unit length of the non-heating wire outside the joining pipe. Therefore, the calorific value per unit length of the portion with the heating wire in the joining tube is intermediate between the heating wire and the non-heating wire outside the joining tube, and the portion with the heating wire in the joining tube is the intermediate heating portion Become.

  The intermediate heat generation portion consumes unnecessary power and has the disadvantage of increasing the possibility of heating a portion which should not be heated. However, in the micro-heater having a non-heat generation portion of the present invention, heat generation into the connecting tube is generated. By shortening the insertion length of the wire, the intermediate heat generation portion can be shortened, and thus, the adverse effect of the intermediate heat generation portion can be suppressed to a small level.

(Second aspect)
In the micro-heater having a non-heating portion of the present invention, the non-heating wire in the joining tube may be only the end portion in contact with the heating wire of the non-heating wire. In this case, there is no concern that disconnection may occur due to the depression of the non-heating wire, and the effect in the first mode in which an excessive temperature increase due to contact resistance does not occur is taken over as it is.

(Third aspect)
Furthermore, the non-heating line in the connecting tube may be the total length of the non-heating line. Also in this case, there is no concern that disconnection may occur due to the depression of the non-heating wire, and no excessive temperature rise due to contact resistance will occur. In addition, since the entire length of the non-heating wire is in the joining tube, the calorific value per unit length of the non-heating part is smaller than that in the case of the non-heating wire not covered by the joining tube, as described above As a result, unnecessary heat generation and power consumption are eliminated.

(Fourth aspect)
The material of the connecting pipe is preferably nickel or copper. Nickel tubules and copper tubules are commercially available and readily available, and it is economically advantageous to make the connecting tube of nickel or copper.
If the material of the connecting tube is copper, the electrical resistivity of copper is low, so the heat generating wire in the connecting tube serving as the intermediate heating portion has a small amount of heat generation, and the non-heating wire has the non-heating wire The part also produces less heat. Therefore, the effect of reducing unnecessary heat generation and power consumption is large.
Also, the electrical resistivity of nickel is higher than that of copper but lower than that of copper, and by using nickel as the material of the connecting tube, the effect of suppressing unnecessary heat generation and power consumption is large even if it is not copper. .

  As described above, the micro-heater having a non-heating portion according to the present invention can eliminate the reduction of the diameter due to the depression near the welding portion with the heating line, which has conventionally occurred, in the non-heating line. There is no concern that the stress will break it. In addition, even if contact between the heating wire and the non-heating wire is insufficient and contact resistance remains, the current also flows to the connecting tube, so there is no additional effect that an excessive temperature rise occurs at the time of use There is also.

Sectional drawing which shows 1st Embodiment of the micro heater with the non-heating part by this invention Sectional view showing a second embodiment of the micro-heater with non-heating part according to the present invention Sectional view showing a third embodiment of the micro-heater with non-heating part according to the present invention Sectional view showing a fourth embodiment of the micro-heater with non-heat generating portion according to the present invention Sectional drawing which shows the boundary part of the heating line and non-heating line in 1st Embodiment of this invention. Sectional view showing a basic first configuration of a conventional micro heater Sectional view showing a basic second configuration of a conventional micro heater Cross-sectional view showing a first basic configuration of a micro-heater having a conventional non-heat generation portion Sectional view showing a second basic configuration of a conventional microheater having a non-heating portion Sectional drawing which shows the boundary part of the heating line and non-heating line in the basic 1st structure of the microheater with the conventional non-heating part

  First to fourth four embodiments for practicing the present invention will be described.

First Embodiment
FIG. 1 is a cross-sectional view showing a first embodiment of a microheater having a non-heating portion according to the present invention, FIG. 1 (a) is a longitudinal cross-sectional view, and FIGS. 1 (b) and (c) are each a diagram It is an AA cross section and a BB cross section of 1 (a). However, the terminal sleeve 9 of FIG. 1 (a) and the insulation coatings 13 and 15 of the lead wires 80 and 81 are drawn in external form, and in order to make it easy to view, FIGS. It is drawn at a large scale. Further, the reference numerals in the figures indicate the same components as those of the conventional micro-heaters shown in FIGS. 6 to 9 have the same reference numerals as those in FIGS. It is similar.

  In the microheater 1 having the non-heat generating portion according to the first embodiment, the inorganic insulating material powder 12 is interposed in the metal sheath pipe 5, and the heating wire 6 made of nichrome and generating Joule heat by energization is made of copper. The non-heating wire 7 having substantially the same diameter as the heating wire 6 and the connecting tube 8 having substantially the same diameter as the heating wire 6 and the non-heating wire 7 having an inner diameter of nickel are accommodated. One end and one end of the non-heating wire 7 are in contact and conducted, and the end of the heating wire 6 in contact with the non-heating wire 7 and the end of the non-heating wire 7 in contact with the heating wire 6 are in the connecting tube 8 , And the inner surface of the connecting tube 8 is in contact with the outer surface of the heating wire 6 and the non-heating wire 7 inside.

  End sleeves 9 are provided at both ends of the metal sheath tube 5, the inorganic insulating material powder 12 and the metal sheath tube 5 other than the connecting tube 8, and lead wires 80 and 81 for the current application to the terminal sleeve 9. The structure in which the conductors 14 and 16 exposed from the insulating coatings 13 and 15 are connected is the same as the conventional microheater 11 having a non-heating portion shown in FIG. In addition, as for the structure in the end sleeve 9, the heating wire shown by the code 22 in FIG. 1 of FIG. 1 by the same applicant as the present patent application and the conductor shown by the code 13 are respectively provided. It is a structure.

  Also in the present embodiment, as in the prior art, in the production of a portion called a microheater cable in which the heating wire 6, the non-heating wire 7 and the joining tube 8 are accommodated with the inorganic insulating material powder 12 interposed in the metal sheath tube As described above, first, one thicker than the finished diameter is first made, and the diameter is reduced to a half to a third by die drawing or swaging to obtain a microheater cable having a predetermined outer diameter.

  The heating wire 6, the non-heating wire 7, and the connecting tube 8 can be inserted in a state where one end of the heating wire 6 and one end of the non-heating wire 7 are in contact and the heating wire 6 and the non-heating wire 7 are barely inserted. By temporarily fixing in a state where the end of the heating wire 6 in contact with the non-heating wire 7 and the end of the non-heating wire 7 in contact with the heating wire 6 are present in the inside diameter connecting pipe 8 After diameter reduction, it becomes the form shown in FIG.

  Since the heating wire 6, the non-heating wire 7, and the joining tube 8 before diameter reduction may be temporarily fixed welding, spot welding can be used, and temperature rise until the entire cross section becomes completely molten as in the prior art is unnecessary. As in the case of the conventional microheater having a nonheat-generating portion, no dent is not generated in the non-heating wire, and no dent is generated in the heating wire 6 and the connecting tube 8 as in the conventional case. Therefore, there is no concern that disconnection may occur due to the depression of the non-heating line as in the conventional micro heater having the non-heating part.

  In addition, even if there is a slight gap between the inner surface of the joining tube 8 and the heating wire 6 and the non-heating wire 7 before reducing the diameter, it is in close contact with the reduced diameter. Therefore, even if the contact between the heating wire 6 and the non-heating wire 7 is insufficient and the contact resistance remains, the inner surface of the connecting tube 8 is in close contact with the surfaces of the heating wire 6 and the non-heating wire 7 in the tube, The current also flows through the connecting tube 8 and has an additional advantage that an excessive temperature rise due to contact resistance in use does not occur.

  The calorific value per unit length is proportional to the resistance per unit length. The resistance value of the portion where the non-heating wire 7 exists in the connecting tube 8 is the resistance value in which the resistances of the non-heating wire 7 and the connecting tube 8 are connected in parallel, so the resistance value per unit length is the connecting tube 8 It is smaller than the resistance value per unit length of the outer non-heating wire 7. This indicates that the portion where the non-heating wire 7 exists in the connecting tube 8 belongs to the non-heating portion, and the calorific value per unit length is smaller than that of the non-heating wire 7 outside the connecting tube 8 . Therefore, all the portions with non-heating wire 7 become non-heating portions.

  On the other hand, the resistance value of the portion where the heating wire 6 exists in the connecting tube 8 is the resistance value in which the resistance of the nichrome heating wire 6 and the connecting tube 8 of nickel are connected in parallel, so the resistance value per unit length Is smaller than the resistance value per unit length of the heating wire 6 of nichrome outside the joining tube 8 and generally larger than the resistance value per unit length of the non-heating wire 7 outside the joining tube 8. Therefore, the calorific value per unit length of the portion where the heating wire 6 exists in the connecting tube 8 is an intermediate amount between the heating wire 6 and the non-heating wire 7 outside the connecting tube 8, and the heating wire is generated in the connecting tube 8 The portion 6 is an intermediate heat generating portion, and the portion where the heat generating wire 6 is outside the connecting pipe 8 is a heat generating portion.

  The intermediate heating portion consumes wasteful power and has the disadvantage of increasing the possibility that the portion not to be heated is heated. However, the micro-heater 1 having the non-heating portion of the present invention is shown in FIG. By shortening the insertion length of the heating wire 6 into the connecting pipe 8 as described above, the middle heating portion is shortened, thereby reducing the harmful effect of the middle heating portion and making it substantially harmless.

  With regard to the material of this embodiment, the heating wire 6, the non-heating wire 7 and the connecting tube 8 are as described above, and the heating wire 6 uses Nichrome, which has a high electrical resistivity and a large heating value, as in the prior art. The calorific value of the part is made equal to that of the conventional micro-heater, and copper with a low electrical resistivity is used for the non-heat generation wire 7 to suppress the calorific value of the non-heat generation part low to limit wasteful power consumption. Is the same as the conventional one.

  Further, regarding the material of the connecting tube 8, a nickel thin tube and a copper thin tube are commercially available and easy to obtain, and using nickel or copper as the material of the connecting tube 8 is economically advantageous. In the present embodiment, the material of the connecting pipe 8 is nickel, but since the electrical resistivity of nickel is as low as that of copper, a portion having the heating wire 6 in the connecting pipe 8 serving as an intermediate heat generating portion, non-heat generating portion The calorific value of the portion where the non-heating wire 7 is in the connecting pipe 8 is low, and there is an advantage that wasteful heat generation and power consumption are suppressed to a low level although not as much as copper.

  The material of the connecting pipe 8 may be copper which has an economic advantage. Since the electrical resistivity of copper is lower than that of nickel, unnecessary heat generation and power consumption are reduced compared to the case of using nickel as a material.

  Other materials are the metal sheath tube 5 is SUS316, and the inorganic insulating material powder 12 is magnesia. These two materials are not limited to this, and the materials may be changed according to the use conditions such as temperature.

  Regarding the cross-sectional shape, the outer diameter of the metal sheath tube 5 of this embodiment is 3.2 mm, the inner diameter is 2.56 mm, the outer diameter of the heating wire 6 and the non-heating wire 7 is 0.77 mm, the thickness of the connecting tube 8 is The outer diameter of the connecting pipe 8 is 1.37 mm at 0.3 mm. The inner diameter of the metal sheath tube 5 and the outer diameters of the heating wire 6 and the non-heating wire 7 are respectively shown in the micro heater 10 of 3.2 mm in the outer diameter of the conventional metal sheath tube 5 shown in FIG. The standard inner diameter of the metal sheath tube 5 and the standard outer diameters of the heating wire 6 and the non-heating wire 7 of the microheater 11 having the non-heating part with the outer diameter of the conventional metal sheathing tube 5 of 3.2 mm It is almost the same.

  FIG. 5 is a cross-sectional view showing the boundary between the heating wire and the non-heating wire in the first embodiment of the present invention, and FIG. 5 (a) is a cross-sectional view before diameter reduction at the time of manufacturing the microheater cable; FIG. 5 (c) is an enlarged view of a portion surrounded by a dashed line in FIG. 5 (b) after the diameter reduction. FIG. 5 shows an example in which temporary welding of the heating wire 6, the non-heating wire 7 and the joining tube 8 before diameter reduction is performed by laser spot welding. The code | symbol 18 in a figure is the temporary fixing | fixed part by the spot welding of the joining pipe | tube 8 and the exothermic line 6. As shown in FIG. If contact between the heating wire 6 and the non-heating wire 7 is not ensured by the method of diameter reduction, temporary spot welding is added to keep the heating wire 6 and the non-heating wire 7 in contact as shown by reference numeral 24. If the weld is raised from the outer diameter of the heating wire 6 and the non-heating wire 7, the raised portion is removed by means of a belter polishing. The spot welds 18, 24 are not illustrated in FIG. 5 (b) because they are difficult to scale. Of course, temporary fixing spot welding of the connecting pipe 8 and the non-heating wire 7 may be additionally performed.

  As the deformation of the connecting tube 8, the outer diameter is made substantially the same as the heating wire 6 and the non-heating wire 7 and the inner diameter is reduced, so that the place where the heating wire 6 and the non-heating wire 7 enter into the connecting tube 8 is narrowed. You may

Second Embodiment
FIG. 2 is a cross-sectional view showing a second embodiment of the microheater having a non-heating portion according to the present invention, and a cross-sectional view in the longitudinal direction is shown. The radial cross section of the portion with the non-heating wire 7 in the connecting pipe 8 is the same as that in FIG. 1 (c). The components having the same functions as those of the conventional micro-heater shown in FIGS. 6 to 9 are denoted by the same reference numerals as those in FIGS. 6 to 9.

  The difference between the micro-heater 2 having the non-heating part of the present embodiment shown in FIG. 2 and the micro-heater 1 having the non-heating part of the first embodiment is that the total length of the non-heating line 7 is in the connecting pipe 8. It is. By doing this, the calorific value per unit length of the non-heat generation portion becomes smaller as compared with the case of the non-heat generation wire 7 which is not covered by the connecting pipe 8 of the first embodiment, as described above. More unnecessary heat generation and power consumption are eliminated as compared with the micro heater 1 having the non-heat generating portion of the embodiment.

  The other features, effects, materials, and cross-sectional dimensions are the same as in the first embodiment, and the description will be omitted.

Third Embodiment
FIG. 3 is a cross-sectional view showing a third embodiment of a microheater having a non-heating portion according to the present invention, FIG. 3 (a) is a longitudinal cross-sectional view, and FIGS. 3 (b) and (c) are each It is a CC cross section of 3 (a), and a DD cross section. However, the end sleeve 9 and the insulation coatings 13 and 15 of the lead wires 80 and 81 in FIG. 3A are drawn in external form, and in order to make it easy to see, FIG. 3B and FIG. Drawing to a large scale is the same as FIG. Further, in the figures, components having the same functions as those of the conventional micro-heater shown in FIGS. 6 to 9 are given the same symbols as in FIGS. 6 to 9.

  The radial direction cross section of the part with the non-heating wire 7 in the pipe of the connecting pipe 8 in FIG. 3 (a) is the same as FIG. 1 (c). The components having the same functions as those of the conventional micro-heater shown in FIGS. 6 to 9 are denoted by the same reference numerals as those in FIGS. 6 to 9.

  The difference between the micro-heater 3 having the non-heating portion of the third embodiment shown in FIG. 3 and the micro-heater 1 having the non-heating portion of the first embodiment is that the heating wire 6 and the non-heating wire 7 Similar to the conventional micro-heater 21 having a non-heat generating portion shown in FIG. 9, the point of reciprocal movement, the point that the end sleeve 9 is provided only on one side, and the ratio of cross-sectional dimensions are different. It is a point.

  The structure in the end sleeve 9 is the structure shown in FIG. 1 of Patent Document 1, and the end sleeve 9 is a conductor 14 exposed from the insulation coatings 13 and 15 of the lead wires 80 and 81 for energization. , 15 are the same as the conventional micro-heater 21 having a non-heating portion shown in FIG.

  Regarding the cross-sectional shape, the outer diameter of the metal sheath tube 5 of this embodiment is 3.2 mm, the inner diameter is 2.56 mm, the outer diameter of the heating wire 6 and the non-heating wire 7 is 0.31 mm, the thickness of the connecting tube 8 is The outer diameter of the connecting tube 8 is 0.61 mm at 0.15 mm. The inner diameter of the metal sheath tube 5 and the outer diameter of the heating wire 6 are respectively the microheater 20 of the conventional metal sheath tube 5 shown in FIG. 7 with an outer diameter of 3.2 mm and the conventional metal sheath shown in FIG. Match the standard inner diameter of the metal sheath tube 5, the standard outer diameter of the heating wire 6 and the standard outer diameter of the non-heating wire 7 of the micro heater 21 with the non-heating part of the outer diameter of the tube 5 of 3.2 mm. There is.

  The other features, effects, and materials are the same as in the first embodiment, and the shape of the boundary between the heating wire 6 and the non-heating wire 7 is also the same as that in FIG.

Fourth Embodiment
FIG. 4 is a cross-sectional view showing a fourth embodiment of the micro-heater having a non-heating portion according to the present invention, and is a cross-sectional view in the longitudinal direction. The radial cross section of the portion where the non-heating wire 7 is present in the connecting pipe 8 is the same as FIG. 3 (c). The components having the same functions as those of the conventional micro-heater shown in FIGS. 6 to 9 are denoted by the same reference numerals as those in FIGS. 6 to 9.

  The difference between the micro-heater 4 having the non-heating portion of the present embodiment shown in FIG. 4 and the micro-heater 3 having the non-heating portion of the third embodiment is that the total length of the non-heating wire 7 is in the connecting pipe 8. It is. By doing this, the calorific value per unit length of the non-heat generation portion becomes smaller as compared with the case of the non-heat generation line 7 which is not covered by the connecting pipe 8 of the third embodiment, as described above. More unnecessary heat generation and power consumption are eliminated as compared with the micro heater 3 having the non-heat generating portion of the embodiment.

  The other features, effects, materials, and cross-sectional dimensions are the same as in the first embodiment, and the description will be omitted.

  As described above, although the finished diameter of the microheater cable in the four embodiments, that is, the outer diameter of the metal sheath tube 5 is 3.2 mm, the mainstream of the microheater cable conventionally used in industry is 1.6 mm to The microheater cable of the microheater having a non-heating part according to the present invention may have the same outer diameter as in the prior art, and the diameter of the heating wire 6 and the non-heating wire 7 may be connected according to the outer diameter. The inside and outside diameter of the tube 8 can be changed.

  The total length of the microheater cable and the position and length of the heat generating part are determined by the distance between the end sleeve and the object to be heated, the size of the object to be heated, etc. Absent.

1 Micro heater with non-heating part (1st embodiment)
2 Micro-heater with non-heating part (2nd embodiment)
3 Micro Heaters with Non-Heating Parts (Third Embodiment)
4 Micro heater with non-heating part (4th embodiment)
Reference Signs List 5 metal sheath tube 6 heating wire 7 non-heating wire 8 connecting tube 9 end sleeve 12 inorganic insulating material powder 80, 81 lead wire 13, 15 lead wire insulating coating 14, 16 conductor of lead wire

(First aspect)
The micro-heater with non-heating part according to the invention is
A metal sheath tube with no change in outer diameter in the axial direction ,
A heating wire housed in a metal sheath tube and made of nichrome and generating Joule heat by energization;
A non-heating wire which is housed in a metal sheath and made of copper and has substantially the same diameter as the heating wire,
A connecting pipe housed in a metal sheath tube and made of metal and having an inner diameter substantially the same as the heating wire and the non-heating wire;
Inorganic insulating material powder filled between the metal sheath tube and the heating wire, the non-heating wire, and the joining tube,
One end of the heating wire and one end of the non-heating wire are in contact with each other in the joining pipe and conducted, and only the end of the heating wire in contact with the non-heating wire and the end of the non-heating wire at least in contact with the heating wire In the connecting tube, the inner surface of the connecting tube is in contact with the heating wire inside and the outer surface of the non-heating wire, and the portion where the non-heating wire exists is outside the connecting tube of the heating wire It is characterized in that it is a non-heat generating portion with a smaller amount of heat generation.

Claims (4)

With a metal sheath,
A heating wire housed in the metal sheath tube and made of nichrome and generating Joule heat by energization;
A non-heating wire which is accommodated in the metal sheath and made of copper and has substantially the same diameter as the heating wire;
A connecting pipe which is accommodated in the metal sheath tube and made of metal and whose inside diameter is substantially the same as the heating wire and the non-heating wire;
And an inorganic insulating material powder filled between the metal sheath tube, the heating wire, the non-heating wire, and the joining tube,
One end of the heating wire and one end of the non-heating wire are in contact with each other in the connecting tube and conducted, and only the end of the heating wire in contact with the non-heating wire, and at least the heating wire of the non-heating wire The contact end portion is in the connecting tube, the inner surface of the connecting tube is in contact with the heating wire inside and the outer surface of the non-heating wire, and the portion where the non-heating wire exists is the heating A micro-heater having a non-heat generation part characterized in that it is a non-heat generation part that generates a smaller amount of heat than a part of the wire outside the connecting pipe.   The micro-heater having a non-heating portion according to claim 1, wherein the non-heating line in the connecting tube is only an end portion of the non-heating line contacting the heating line.   The micro-heater with non-heating part according to claim 1, wherein the non-heating line in the joining tube is the entire length of the non-heating line. The micro-heater with non-heating portion according to claim 1, wherein the material of the connecting pipe is nickel or copper.

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