JP4092686B2 - Heating device for thermoplastic resin molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in an apparatus for heating a welded portion of a thermoplastic resin molded body, and more specifically, is molded from a thermoplastic resin such as PP, ABS, PMMA, PC, AAS, PS, PEI, PA, POM. The present invention relates to an improvement of an apparatus suitable for heating a welded portion when a thermoplastic resin molded body is welded to produce a finished product.
[0002]
[Prior art]
Conventionally, as an apparatus for heating a welded portion of a thermoplastic resin molded body, as shown in FIG. 6, the apparatus has a shape corresponding to the welded surface of the thermoplastic resin molded body M and is made of a highly thermally conductive material such as aluminum. There is one in which the metal block 63 is heated by a cartridge heater 62 embedded therein, and the welded portion 61 is heated and softened by the heat of the metal block 63.
[0003]
[Problems to be solved by the invention]
However, in the conventional heating apparatus configured as described above, the entire metal block must be heated, so that the heat capacity is large and the heat radiation area is widened. Therefore, the metal is heated to a temperature sufficient to heat and soften the welded portion. In order to raise the temperature of the block surface, a long time and a large amount of electric power were required. Also, if the weld surface of the welded portion of the thermoplastic resin molding has a three-dimensionally expanding shape, or if there are obstacles such as ribs near the welded portion, the surface of the metal block and the cartridge Since it is difficult to arrange the distance from the heater uniformly over the entire area, the surface temperature of the metal block cannot be made uniform over the entire area. Along with this, the welded part is overheated and deteriorated, foam burrs are generated and the appearance of the thermoplastic resin molded product is greatly impaired, or the welded part becomes insufficiently softened due to insufficient heating. There is a problem that the welding strength cannot be obtained.
[0004]
The present invention has been made in view of the above circumstances, and an object of the present invention is to be able to heat to a required temperature in a very short time and with low power consumption, and to heat a welded portion of a thermoplastic resin molded body to a substantially uniform temperature. It is in providing the heating apparatus which can do.
[0005]
[Means for Solving the Problems]
In order to achieve the above-described object, the thermoplastic resin molded body heating device according to the present invention has a structure in which at least one of the above-mentioned thermoplastic resin molded bodies is welded to each other when two or more thermoplastic resin molded bodies are welded together. after heating and softening the heated portion of the two or more of the thermoplastic resin molded article having a heating portion for welding to the thermoplastic resin molded article, and pressed against the heating portion and the welding portion of the thermoplastic resin molded article Upon welded together, a heating apparatus for heating and softening the heated portion, electric heating between the energization heater that generates heat by extending and energized in opposition to the heating portion, said heating portion and said energization heater A plate that is arranged at an appropriate distance from the body, extends opposite to the energization heating element, is heated by the energization heating element, and then heats and softens the heated portion, or the energization heating element is hot. The volume or / and area can be increased at the location where the heat is applied, or the volume or / and area can be decreased at the location where the energization heating element is at a low temperature, and the amount of heat corresponding to the temperature, volume and shape of the energization heating element can be retained. And a high thermal conductivity material that conducts radiant heat from the energization heating element in a band shape, and holding means that holds the energization heating element and the high thermal conductivity material.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The energization heating element in the present invention is a metal having a high electric resistance such as nickel / chromium alloy, iron / chromium alloy, etc., formed in a coil shape, a wire shape or a strip shape, or these energization methods. A sheathed heater using a heating element may be used.
It generates heat when current is passed through it. When the welded portion of the thermoplastic resin molded body is bent at a right angle or an acute angle, or when the welded surface of the welded portion extends three-dimensionally, it is desirable to form a coil from the viewpoint of manufacturing or mounting. . Moreover, the thermal expansion of the energization heating element itself can be absorbed by forming it in a coil shape. Here, the coil shape means a shape obtained by winding a linear energization heating element around a rod having a circular, elliptical or polygonal cross-sectional shape. Further, when the energization heating element is a nickel-chromium wire, even if the diameter is 1.0 mm or less, it is sufficient to heat and soften the welded portion through a high thermal conductive material, and heat can be generated with a small amount of electric power. However, 0.04 to 1.0 mm is preferable. Further, it is appropriate that the inner diameter of the coil is not more than 10 times the diameter of the wire, and the pitch of the coil is 2 to 3 times the diameter of the wire.
[0007]
In addition, the high thermal conductivity material in the present invention is any material as long as it has good thermal conductivity, such as copper, aluminum, alloys thereof, and carbon, has a small heat capacity, and can be easily three-dimensionally bent or shaped. But you can. Moreover, the said high heat conductive material can heat-soften a welding part by approaching or contacting the welding surface of the welding part of a thermoplastic resin molding. In the case of contact, the contact surface with the welded portion may be coated with silicon, Teflon or the like in order to prevent adhesion of the welded portion. Further, when maintenance is required, it is only necessary to replace the high thermal conductivity material, and maintenance time, cost, and weight can be greatly reduced as compared with a conventional metal block embedded in a cartridge heater. In addition, the high thermal conductivity material may be an integral type when attached to the holding means, but may be a divided type in consideration of thermal expansion.
[0008]
In addition, the high thermal conductivity material can improve the heating efficiency by radiant heat by treating the surface with a ceramic such as zirconia having a far infrared radiation effect. In addition, the high thermal conductivity material has a large volume or / and area at a location where the energization heating element becomes high temperature or a small volume or / and area at a location where the energization heating element becomes low temperature. The temperature of the entire surface of the conductive material can be adjusted almost uniformly.
For example, when the energization heating element has a coil shape and the welding surface of the welding portion extends three-dimensionally, a portion having a long pitch and a portion having a short pitch are generated. Along with this, the energization heating element has a portion where the radiant heat is weak and a portion where the radiant heat is weak, but by adjusting the capacity partially so that the high thermal conductivity material reaches a predetermined temperature, the high thermal conductivity material A substantially uniform temperature can be obtained over the entire area.
[0009]
Further, the holding means in the present invention has an insulating property and has a function of holding at least the energizing heating element embedded in a groove shape.
[0010]
[Example 1]
Example 1 of the heating apparatus to which the present invention is applied will be described in detail with reference to FIG. As shown in FIG. 1, the heating device includes an energizing heating element 2 that extends opposite to a welding portion 1 of a thermoplastic resin molded body M and generates heat by energization, and the welding portion 1 and the energizing heating element 2. A copper plate 3 as a high thermal conductive material disposed between and extending opposite the energizing heating element 2 and heating and softening the welded portion after being heated by the energizing heating element 2, and the energizing heating element 2 and the high thermal conductivity And holding means 4 for holding the material 3. And the said thermoplastic resin molded object M is hold | maintained by the molded object holder 5 arrange | positioned above the said heating apparatus so that raising / lowering is possible.
[0011]
The holding means 4 includes a holding body 7 made of a machinable ceramic having a groove 6 extending on the upper surface facing the welded portion 1 of the thermoplastic resin molded body M, and having insulation and heat resistance. A pair of machinable ceramic pressing members 8 and 8 which are mounted on the main body 7 and extend along the groove 6 to hold the copper plate 3 from above and have insulation and heat resistance, and the holding main body 7 are supported. A platen-shaped support member 9 is used. The groove 6 has a two-step shape with a wide upper portion so that the energization heating element 2 can be accommodated by placing the energization heating element 2 at the bottom position and the copper plate 3 at a position immediately above the energization heating element 2. is doing. In addition, the width of the upper portion of the groove 6 is substantially equal to or slightly wider than the width of the copper plate 3, and the depth of the upper portion is equal to or slightly smaller (shallow) than the thickness of the copper plate 3. The upper surface of the copper plate 3 coincides with the upper surface of the holding body 7 or slightly protrudes. Further, the width and depth of the lower portion of the groove 6 are slightly wider and deeper than the outer diameter of the coil of the energization heating element 2 so that the energization heating element 2 does not contact the copper plate 3 to prevent electric shock. It has become. When contacted, the contact surface is covered with an insulating material.
[0012]
Further, the holding member 8 is composed of two strip-shaped components, and protrudes from both sides of the groove 6 toward the inside of the groove 6 to adjust the distance on the upper surface of the copper plate 3 corresponding to the welded portion. Can be done. The pressing member 8 is as thin as possible and needs to be strong enough to prevent deformation of the copper plate 3. For this reason, the pressing member 8 is a sheet having an insulating property in contact with the copper plate 3. You may use metal plate materials, such as stainless steel in which the heat-resistant material of the shape was interposed. Furthermore, the pressing member 8 may be firmly fixed to the holding body 7 by a fixing means having a low head, such as a low head bolt, a headless hook, or a U-shaped locking bracket (not shown). As a result, the copper plate 3 can be strongly held and fixed so as not to be deformed by the bottom of the groove 6 and the pressing member 8.
[0013]
In this configuration, the energization heating element 2 is heated by supplying power to the energization heating element 2, and the entire copper plate 3 is heated to a required temperature in a relatively short time by radiant heat from the energization heating element 2. The copper plate 3 heated in this manner heats the welded portion 1 by the approach or contact of the welded portion 1.
[0014]
[Example 2]
As shown in FIG. 2, when the rib 22 in the thermoplastic resin molded body M is close to and adjacent to the welded portion 21 and is longer than the welded portion 21, the copper plate 3 of Example 1 has the welded portion 21. It cannot be heated sufficiently. In this case, the high thermal conductivity material 23 instead of the copper plate 3 has a structure having a protruding surface extending in a three-dimensional manner, ie, a band having a shape that rises up facing the welding surface of the welding portion 21. It may be plate-shaped. Thereby, only the welding surface of the welding part 21 can be heated appropriately. In this case, the holding member 8 that holds the high thermal conductivity material 23 needs to be covered so as not to melt the rib 22. Other components are the same as those in the first embodiment.
[0016]
[Example 3]
As shown in FIG. 3, only the energization heating element 2 may be embedded in the holding body 37 and the energization heating element 2 may be held by the holding body 37. In this case, the groove 36 can be easily cut.
In addition, the code | symbol 38 is a pressing member in the figure, and other components are the same as Example 1. FIG.
[0017]
[Example 4]
As shown in FIG. 4, when the welding surface of the welded portion 41 of the thermoplastic resin molded body M is discontinuous, when the copper plate 43 as the high thermal conductivity material is discontinuous, the coiled energization heating element 42 is provided. The portion where the copper plate 43 is absent may be located on the back side of the holding body 47. By doing so, it is possible to supply power to the energization heating element 42 even from a single power source.
[0018]
[Example 5]
As shown in FIG. 5, an energization heating element 52 is embedded in a region facing the welded portion of the high thermal conductivity material 53 within a range in which the entire surface of the high thermal conductivity material 53 can be heated to a substantially uniform temperature. Also good. In this case, it is possible to ensure insulation with respect to the high thermal conductivity material 53 by using an insulating heating element 52 such as a sheath heater or a micro heater.
In addition, by providing the holding body 57 with a groove 56 that extends to face the high thermal conductivity material 53, the flow of heat from the high thermal conductivity material 53 to the holding body 57 is reduced, and the high thermal conductivity material 53. Since the heat capacity of the part to be heated is increased, the temperature of the entire surface of the high thermal conductivity material 53 can be easily made uniform.
[0019]
[Example 6]
As shown in FIG. 6, the heating device to which the present invention is applied may be disposed above the thermoplastic resin molded body M opposite to that in the first embodiment. In this case, the coiled energization heating element 2 may be supported by a wire 67 having insulation and heat resistance, such as glass fiber, or a U-shaped locking fitting 67 attached to the holding body 7. Good.
[0020]
【effect】
The above clearly seen the invention from the description, in the case of producing a mutually welded to PVC two or more thermoplastic resin molded article, for welding to at least one of the thermoplastic resin molded article after heating and softening the heated portion of the two or more of the thermoplastic resin molded article having a heating portion, when welded to each other by pressure contact with the heating portion and the welding portion of the thermoplastic resin molded article, the heated portion A heating device for softening by heating, the energizing heating element extending opposite to the heating portion and generating heat by energization, and the energizing heating element between the heating portion and the energizing heating element with an appropriate interval provided by the energization heater plate or to heat soften the heated part after being heated by extending to face and energization heater, the volume or / and a point where the electric heating element becomes high The area or the area where the energization heating element becomes cold can be reduced in volume or / and area so that the amount of heat corresponding to the temperature, volume and shape of the energization heating element can be retained and a belt- like shape is formed. Since it has a high thermal conductivity material that conducts radiant heat from the energization heating element and a holding means that holds the energization heating element and the high thermal conductivity material, a conventional cartridge heater is embedded to heat up the entire metal block. Compared to a heating device that heats, the present invention has a very small heat capacity, and it is uniform in correspondence with the entire heating surface of the heated portion of the thermoplastic resin molded body with a very short time of heating and low power consumption. There are excellent practical effects such as the ability to secure heat at the required temperature.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing a third embodiment of the present invention.
FIG. 4 is a longitudinal sectional view showing a fourth embodiment of the present invention.
FIG. 5 is a longitudinal sectional view showing a fifth embodiment of the present invention.
FIG. 6 is a longitudinal sectional view showing a sixth embodiment of the present invention.
FIG. 7 is a longitudinal sectional view showing a conventional heating device.
[Explanation of symbols]
1 welding portion 2 energization heating element 3 copper plate 4 holding means

Claims (3)

In the case of producing a finished product with each other welding two or more thermoplastic resin molded article, two or more of the thermoplastic resin having a heating portion for welding to at least one of the thermoplastic resin molded article after the heating portion was heated and softened in the forming body, when welded to each other by pressure contact heating portion and the welding portion of the thermoplastic resin molded article, a heating apparatus for heating and softening the heated portion,
An energization heating element 2 extending opposite to the heating portion and generating heat by energization;
The heating portion after the energization heater 2 is heated by and energization heater 2 extends to face the energization heater 2 is disposed at appropriate intervals during the heating portion and the energization heater 2 The volume or / and area is increased at a plate-like shape that heats and softens, or the energization heating element 2 is at a high temperature, or the volume or / and area is decreased at a location where the energization heating element 2 is at a low temperature, the temperature of the energization heater 2, a high thermal conductivity material 3 for conducting radiant heat from the energization heater 2 forms a is and strip can retain heat corresponding to the volume and shape,
Holding means 4 for holding the energization heating element 2 and the high thermal conductivity material 3 ;
An apparatus for heating a thermoplastic resin molded body, comprising: In the heating apparatus of the thermoplastic resin molding according to claim 1,
The energizing heating element 2 has a thermoplastic resin molded body heating device in which a portion of the welded portion facing a portion that should not be heated is disposed on the back side of the holding means 4. In the heating apparatus of the thermoplastic resin molding according to claim 1 or 2,
The heating device for a thermoplastic resin molded body, wherein the high thermal conductivity material 3 covers a portion of the welded portion facing a portion that should not be heated with a heat insulating member.

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