JP5461220B2 - Manufacturing method of planar heater and planar heater - Google Patents

Description

  The present invention relates to a method for manufacturing a planar heater that uses electrical energy for heating a fluid that circulates mainly in a cylindrical thin tube, and a planar heater. More specifically, when a large number of types of sheet heaters for heating the fluid flowing through the inside of various types of thin tubes having different outer diameters, etc. are produced, these sheet shapes can be efficiently and easily produced. The present invention relates to a manufacturing method and a planar heater capable of manufacturing a heater.

  2. Description of the Related Art Conventionally, planar heaters that are attached to the outer surfaces of various pipes and the like and heat fluid flowing through the pipes have been widely used. As a form of such a heater, for example, as shown in JP-A-11-74066 and JP-A-2004-158271, a tape-like heater wound around the outer circumference of a pipe, JP 2000-505582A, is disclosed. As shown in Japanese Laid-Open Patent Publication Nos. 2002-295883 and 2002-352941, jacket heaters in which a heating element and a heat insulating material are integrated have been developed.

  In addition, as a heating element used in the planar heater as described above, a glass cloth is impregnated using a synthetic resin (conductive resin) containing graft carbon, carbon powder, metal powder, or metal oxide powder. Ingredients, those obtained by applying or printing a conductive resin such as the above to an insulating base sheet such as polyester, polyimide, mica, etc., those obtained by etching a metal foil into a circuit, or insulating metal resistance wires Examples include a circuit formed on a substrate sheet.

Japanese Patent Laid-Open No. 11-74066 Special table 2000-505582 JP 2002-295883 A Japanese Patent Laid-Open No. 2002-352941 JP 2004-158271 A

  However, the tape-shaped heater is installed around the pipe to be heated, etc., so that the temperature distribution tends to be non-uniform, and it is necessary to prepare a heat insulating material that matches the outer periphery. In some cases, there is a problem in terms of heat insulation. The jacket heater is excellent in uniformity of temperature distribution and heat insulation because the heating element and the heat insulating material are integrated, but when attached to the outer peripheral surface of a pipe or the like, for example, as shown in Patent Document 2, There is an inconvenience that it takes time to manufacture a cylindrical heater in which a heating element and a heat insulating material are integrated. Moreover, although the heat insulating material can be extruded by an extruder and the heat insulating material can be formed on the outer peripheral side of the cylindrical heating element, it is not suitable for multi-product small-scale production.

  Therefore, the problem to be solved by the present invention is a manufacturing method and a planar shape of a planar heater that uses electrical energy for heating a fluid flowing through a cylindrical pipe, particularly a narrow pipe, from the outer peripheral side of the pipe. Manufacturing method of planar heater and planar heater that can be manufactured efficiently and easily even when the heater is a small variety of small-sized heaters (when small-sized planar heaters having different inner diameters are produced) Is to provide.

  As a result of intensive studies to solve these problems, the present inventors have determined that a mold (cylindrical or cylindrical having a slit in the longitudinal direction) having a cylindrical outer peripheral surface with a predetermined outer diameter. Prepare the heat-shrinkable resin tube in advance and place (set) the heat-shrinkable resin tube on the outer peripheral surface of these molds and heat it to shrink the heat-shrinkable resin tube. I found out that Furthermore, a heating element and an insulating resin sheet are arranged on the outer peripheral surface, and after heating to form a flexible cylindrical surface heater, the longitudinal direction is slit by a cutter or the like. The present inventors have found that a sheet heater having a slit can be easily obtained, and arrived at the sheet heater manufacturing method and sheet heater of the present invention.

  That is, according to the present invention, after the heat-shrinkable resin tube is disposed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface having a predetermined outer diameter, the heat-shrinkable resin tube is contracted by heating and molded into a cylindrical shape. The heat shrinkable heat-shrinkable resin tube is disposed on the outer peripheral surface of the heat-shrinkable resin tube so as to overlap the heat-generating element and the insulating resin sheet having flexibility, and the heat-shrinkable heat-shrinkable resin tube, the heat-generating element, and the heat-shrinkable resin tube An insulating resin sheet is heated to be integrally formed into a cylindrical shape, and further a slit is formed.

  In the present invention, the heat-shrinkable resin tube is disposed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface having a predetermined outer diameter, and the heat-shrinkable resin tube is contracted by heating to be formed into a cylindrical shape. Thereafter, the heat-shrinkable resin tube, the heat-generating element, and the heat-shrinkable resin tube, the heat-shrinkable resin tube, the heat-shrinkable resin tube, the heat-shrinkable resin tube, the heat-shrinkable resin tube, The sheet heater is characterized in that the insulating resin sheet is heated and integrally formed into a cylindrical shape, and further slits are formed.

  According to the method for manufacturing a planar heater of the present invention, various types of planar heaters (planar heaters having different inner diameters) can be easily and inexpensively manufactured without requiring a complicated apparatus or an expensive apparatus. Can do. Moreover, the planar heater manufactured by the manufacturing method of the planar heater of the present invention is a cylindrical heater having a slit along the longitudinal direction and has flexibility. By attaching and then releasing the hand, it can be easily attached to the target pipe with good adhesion.

The planar heater manufacturing method and planar heater of the present invention are applied to the planar heater manufacturing method and planar heater using electric energy for heating the fluid flowing through the cylindrical pipe. In particular, the present invention is suitably applied to a method for manufacturing a planar heater for heating a thin tube (diameter of about 2 to 10 mm) and the planar heater.
Hereinafter, although the manufacturing method and planar heater of the planar heater of this invention are demonstrated based on FIGS. 1-5, this invention is not limited by this.

  FIG. 1 is a vertical view showing an example when the heat-shrinkable resin tube is disposed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface with a predetermined outer diameter and a groove for cutting the slit portion. It is sectional drawing. FIG. 2 is a perspective view showing an example when the heating element is arranged on the insulating resin sheet. FIG. 3 is a vertical cross-sectional view showing an example when the heat generating element and the insulating resin sheet are arranged on the outer peripheral surface of the heat-shrinked resin tube. FIG. 4 is a vertical cross-sectional view showing an example in which a slit is formed in the longitudinal direction of a cylindrical molded body formed of a heat-shrinkable heat-shrinkable resin tube, a heating element, and an insulating resin sheet. FIG. 5 is a perspective view (cross-sectional cut view) showing an example of a planar heater manufactured by the manufacturing method of the present invention.

  As shown in FIG. 1, the manufacturing method of the planar heater according to the present invention has a heat-shrinkable resin tube 1 disposed on the outer peripheral surface of a mold 2 having a cylindrical outer peripheral surface having a predetermined outer diameter, and heated to After the heat-shrinkable resin tube 1 is shrunk and formed into a cylindrical shape, as shown in FIG. 3, the heat-shrinkable resin tube 1 ′ and the heat-insulating resin tube 1 ′ have heat-generating elements 4 and flexible insulation on the outer peripheral surface. The resin sheet 5 is placed in an overlapping manner, and the heat-shrinkable resin tube 1 ′, the heat generating element 4 and the insulating resin sheet 5 that have been heat-shrinked are heated and integrally formed into a cylindrical shape, and further shown in FIG. In this way, the slit 6 is inserted.

  Examples of the material of the heat-shrinkable resin tube used in the present invention include silicone resin, Teflon (registered trademark) resin, polyolefin resin, polyester resin, and vinyl chloride resin. It is preferable to use a silicone resin because it is flexible and has excellent processability. The diameter of the heat-shrinkable resin tube before shrinkage is larger than the diameter of the completed planar heater, and the size is determined by the shrinkage rate of the heat-shrinkable resin tube used.

  The heat-shrinkable resin tube is disposed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface with a predetermined outer diameter, and then contracts by heating the mold to 90 to 200 ° C. and heating it. Adheres closely to the outer peripheral surface of the cylinder of the mold. Therefore, a flexible cylindrical resin having an inner diameter substantially the same as the outer diameter of the mold can be easily obtained. In addition, the thickness of the heat-shrinkable resin tube after shrinkage is usually 0.2 to 4 mm, preferably 0.3 to 3 mm. When the thickness is less than 0.2 mm, the electrical insulation is deteriorated, and when the thickness exceeds 4 mm, the thermal conductivity to the pipe may be deteriorated.

  Next, the heat generating element 4 and the flexible insulating resin sheet 5 are disposed on the outer peripheral surface of a flexible cylindrical resin (resin tube 1 ′) obtained by shrinking the heat-shrinkable resin tube 1. The At that time, after arranging the heat generating element, an insulating resin sheet may be arranged on the outside thereof, but if this method is performed, a space is easily formed between the cylindrical resin, as shown in FIG. It is preferable to provide a recess in the insulating resin sheet 5 in advance and arrange the heat generating element 4 or to embed the heat generating element in the insulating resin sheet (inside the vicinity of the surface) so that the surface is not uneven as much as possible. . In any of the methods, it is more preferable that the surface of the insulating resin sheet after the heat generating element is arranged is not uneven.

  The heating element used in the present invention includes a metal resistance wire as shown in FIG. 2, a metal foil etched into a circuit, graft carbon, carbon powder, metal powder, or metal oxide powder. And the like obtained by impregnating, coating, or printing on a flexible base material. These heating elements are usually flexible with a predetermined thickness. The insulating resin sheet is not particularly limited as long as it has electrical insulation, heat insulation, and flexibility with a predetermined thickness. For example, silicone resin, Teflon (registered trademark) resin, polyolefin resin, polyester Examples thereof include a resin and a vinyl chloride resin, and among these, a silicone resin is preferable. The thickness of the insulating resin sheet is usually 0.5 to 10 mm, preferably 1 to 5 mm. When the thickness is less than 0.5 mm, the electrical insulation and heat insulation properties deteriorate, and when the thickness exceeds 10 mm, the flexibility may deteriorate.

  In the method for manufacturing the planar heater of the present invention, as shown in FIG. 3, after the heat generating element 4 and the insulating resin sheet 5 are disposed on the outer peripheral surface of the heat-shrinked resin tube 1 ′, these are heated. It is integrally formed into a cylindrical shape. In the case of integral molding, these are usually heated to 90 to 200 ° C. Subsequently, a slit is made by a cutter or the like in the longitudinal direction of the molded body. Although it does not restrict | limit to the formation method of a slit, as shown in FIG. 4, when the metal mold | die provided with the groove | channel 3 for cutting a slit part is used, a slit can be formed easily. In the cross section of the cylinder, the angle formed by the line connecting the center point and the end of the slit (angle α in FIG. 4) is usually within 90 degrees, preferably within 45 degrees, and more preferably within 30 degrees. .

  The planar heater of the present invention is a planar heater manufactured by the above-described manufacturing method, and a heat-shrinkable resin tube is disposed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface with a predetermined outer diameter and heated. After the heat-shrinkable resin tube is shrunk and formed into a cylindrical shape, a heat-generating element and a flexible insulating resin sheet are placed on the outer peripheral surface of the heat-shrinkable resin tube that has been heat-shrinked. The heat-shrinkable resin tube that has been shrunk, the heat generating element, and the insulating resin sheet are integrally formed into a cylindrical shape by heating, and further a slit heater. That is, as shown in FIG. 5, there is a space for holding a pipe to be heated at the center, and a flexible cylindrical resin (heat A heat-shrinkable resin tube 1 ′) that has already been shrunk, and further includes a heating element 4 and an insulating resin sheet 5 on the outside thereof, and further a slit heater 6 that has a slit 6 in the longitudinal direction.

  The planar heater of the present invention is a cylindrical heater having a slit along the longitudinal direction, and has flexibility. When this is arranged on the pipe to be heated, the angle α (FIG. 4) is widened by manually pushing the slit wide, and can be easily attached to the pipe. Next, when the hand is released, the angle α is narrowed to the original state and can be easily brought into close contact with the target pipe. Therefore, the fluid flowing through the inside of the pipe can be efficiently heated.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

[Example 1]
(Manufacture of planar heaters)
A silicone resin tube (inner diameter: 15 mm, length: 500 mm, thickness: 1 mm) is used as the heat-shrinkable resin tube, and as shown in FIG. 1, a mold having an inner diameter of 8 mm, a length of 600 mm and two grooves in the longitudinal direction ( The silicone resin tube was placed on the outer peripheral surface of each groove having a width of 1 mm and an angle α of 15 degrees, and then heated at 180 ° C. for 5 minutes to shrink the silicone resin tube.

  On the other hand, a lead wire 8 for supplying power and a metal resistance wire (heating element 4) are connected by a crimp connection terminal 7, and a silicone resin sheet (25 mm in length, 500 mm in width, thickness) is used as a flexible insulating resin sheet. 2 mm), the metal resistance wires were embedded in the silicone resin sheet at a depth such that the metal resistance wires could be slightly seen in the arrangement as shown in FIG.

  Next, the metal resistance wire and the silicone resin sheet are wound around the outer peripheral surface of the contracted silicone resin tube as shown in FIG. 3, and a polyester film is wound around the outer surface and fixed as a release film. . These were put into a hot air drier and heated at 200 ° C. for 30 minutes to be integrally formed. After that, after curing at 180 ° C. for 2 hours, the slit portion was cut along the groove of the mold, and a cylindrical planar heater with a slit (inner diameter 8 mm, length 500 mm, thickness 2. 6 mm, angle α15 degrees).

(Evaluation of sheet heater)
The planar heater manufactured as described above has excellent flexibility, and can be easily attached to a pipe with an outer diameter of 8 mm by manually spreading the slit, and then easily released by attaching the hand to the pipe. It was possible to attach closely. As a result of energization, it was confirmed that the heat generation characteristics were also good.

[Example 2]
(Manufacture of planar heaters)
A polyolefin resin tube (inner diameter: 15 mm, length: 500 mm, thickness: 0.4 mm) is used as the heat-shrinkable resin tube, and as shown in FIG. After placing the tube, the polyolefin resin tube was contracted by heating at 120 ° C. for 3 minutes.

  On the other hand, a lead wire 8 for supplying power and a metal resistance wire (heating element 4) are connected by a crimp connection terminal 7, and a polyolefin-based resin sheet (25 mm length, 500 mm width, In the arrangement as shown in FIG. 2, the metal resistance wire was embedded in the polyolefin resin sheet at such a depth that the metal resistance wire was slightly visible.

  Next, the metal resistance wire and the polyolefin resin sheet are wound around the outer peripheral surface of the contracted polyolefin resin tube as shown in FIG. 3, and a polyester film is wound around the outer surface as a release film. Fixed. These were put into a hot air dryer and heated at 180 ° C. for 30 minutes for integral molding. Then, the slit part was cut along the groove | channel of a metal mold | die, and the cylindrical planar heater (inner diameter 8mm, length 500mm, thickness 1.8mm, angle | corner (alpha) 15 degree | times) with a slit was obtained.

(Evaluation of sheet heater)
The planar heater manufactured as described above has excellent flexibility, and can be easily attached to a pipe with an outer diameter of 8 mm by manually spreading the slit, and then easily released by attaching the hand to the pipe. It was possible to attach closely. As a result of energization, it was confirmed that the heat generation characteristics were also good.

  As in the above-described embodiments, it can be seen that the method for manufacturing a planar heater of the present invention makes it possible to easily manufacture a wide variety of planar heaters at low cost without requiring a complicated apparatus or an expensive apparatus. It was. In addition, the planar heater manufactured by the manufacturing method of the planar heater of the present invention is a cylindrical heater having a slit along the longitudinal direction and has flexibility. It was confirmed that by attaching and then releasing the hand, it could be easily attached to the target pipe with good adhesion.

Vertical sectional view showing an example when the heat-shrinkable resin tube is arranged on the outer peripheral surface of a mold having a cylindrical outer peripheral surface of a predetermined outer diameter and having a groove for cutting the slit portion The perspective view which shows an example at the time of arrange | positioning a heat generating element to an insulating resin sheet Vertical sectional view showing an example when a heat-generating element and an insulating resin sheet are arranged on the outer peripheral surface of a heat-shrinkable heat-shrinkable resin tube. Vertical sectional view showing an example in which a slit is provided in the longitudinal direction of a cylindrical molded body made of a heat-shrinkable heat-shrinkable resin tube, a heating element, and an insulating resin sheet The perspective view which shows an example of the planar heater manufactured by the manufacturing method of this invention (cross-section cut figure)

DESCRIPTION OF SYMBOLS 1 Heat-shrinkable resin tube 1 'Heat-shrinkable heat-shrinkable resin tube 2 Mold 3 Groove 4 Heating element 5 Insulating resin sheet 6 Slit 7 Crimp connection terminal 8 Lead wire

Claims (7)

  The heat-shrinkable resin tube is placed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface of a predetermined outer diameter, and the heat-shrinkable resin tube is shrunk by heating and molded into a cylindrical shape. A heat-generating element and a flexible insulating resin sheet are placed on the outer peripheral surface of the heat-shrinkable resin tube, and the heat-shrinkable resin tube, the heat-generating element, and the insulating resin sheet that have been heat-shrinked are heated. Then, a method for manufacturing a planar heater, which is integrally formed into a cylindrical shape and further includes a slit.   The surface according to claim 1, wherein the heat generating element and the insulating resin sheet are preliminarily embedded in a concave portion of the insulating resin sheet and integrated before the heat shrinkable heat-shrinkable resin tube is disposed on the outer peripheral surface of the heat-shrinkable resin tube. Manufacturing method of a cylindrical heater.   The heat-shrinkable resin tube is placed on the outer peripheral surface of a mold having a cylindrical outer peripheral surface of a predetermined outer diameter, and the heat-shrinkable resin tube is shrunk by heating and molded into a cylindrical shape. A heat-generating element and a flexible insulating resin sheet are placed on the outer peripheral surface of the heat-shrinkable resin tube, and the heat-shrinkable resin tube, the heat-generating element, and the insulating resin sheet that have been heat-shrinked are heated. Then, the sheet heater is integrally formed into a cylindrical shape, and further has a slit.   The planar heater according to claim 3, wherein the heat-shrinkable resin tube is a silicone resin, a Teflon (registered trademark) resin, a polyolefin resin, a polyester resin, or a vinyl chloride resin.   The planar heater according to claim 3, wherein the insulating resin sheet is a silicone resin, a Teflon (registered trademark) resin, a polyolefin resin, a polyester resin, or a vinyl chloride resin.   The planar heater according to claim 3, wherein the heating element is a metal foil resistor or a metal wire resistor.   The planar heater according to claim 3, wherein the heating element is a resistor in which at least one selected from graft carbon, carbon powder, metal powder, and metal oxide powder is kneaded in a heat-resistant resin.

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