JPH08132530A - High frequency heating device for plastic tube, and high frequency heating and welding apparatus equipped therewith - Google Patents

Abstract

PURPOSE: To provide an inexpensive high capacity high frequency heating device adaptable to a plastic tube from which aluminum foil is excluded while utilizing an existing high frequency generator or an existing press device as it is, and further provide a high frequency heating and welding apparatus equipped therewith. CONSTITUTION: The support member 16 loosely fitted to the opening welding part 1a of a plastic tube 1 from below is provided and the metal ring 25 positioned within the opening welding part 1a of the plastic tube 1 is fitted to the outer periphery of the intermediate part of the support member 16 through a clearance. An induction heating coil 26 allowing the metal ring 25 to generate heat by the current supply operation of a high frequency generator 9 is provided on the outer peripheral side of the metal ring 25 so as to surround the metal ring 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating apparatus for a plastic tube for heating and welding an opening weld portion of a thermoplastic tube, and a high-frequency heating welding apparatus including the same.

[0002]

2. Description of the Related Art Conventionally, as a tube for filling and wrapping a toothpaste, a "laminate tube" in which aluminum foil is laminated on plastic has been used from the viewpoint of increasing packaging characteristics. The high-frequency welding system is widely adopted for the high-speed filling and sealing machine targeted for. This high-frequency welding method causes an eddy current in the aluminum foil laminated in the plastic by the induction heating method and melts the plastic by the heat conduction of the Joule heat to perform compression welding, so to speak, the packaging material itself generates heat. This is a heat welding method. As prior art documents of this type, there are FIGS. 1 to 4 of JP-A-59-162018.

[0003]

By the way, in recent years, environmental problems and resource problems have been actively discussed internationally, and due to the influence, in the field of packaging as well, the development of plastic tubes that eliminate aluminum foil from laminated tubes is progressing. I am doing it. When using this plastic tube, the high-frequency welding equipment that has been used in high-speed filling and sealing machines up to now is
As a matter of course, it is useless as it is, so it is possible to use other methods (for example, hot air welding method, radiant heating furnace welding method, ultrasonic vibration welding method, hot plate contact welding method, etc.). It needs to be modified or the entire high speed filling and sealing machine must be replaced.

However, other methods such as the hot air welding method, the radiant heating method in the furnace, the ultrasonic vibration welding method, and the hot plate contact welding method are all stable for high-speed filling and sealing machines. There were many problems in terms of sex. Further, it has been extremely difficult and extremely difficult to modify the welding device portion of the conventional high-speed filling and sealing machine to the other system. Therefore, in the case of using the plastic tube excluding the aluminum foil, after all, there was a problem that a large amount of capital investment was required and the entire equipment was replaced.

The present invention has been made in view of the above problems, and is an inexpensive and high-performance plastic tube that can be applied to a plastic tube from which aluminum foil has been removed, while using existing high-frequency generators and presses as they are. It is an object of the present invention to provide a high-frequency heating device and a high-frequency heating welding device including the same. Another object of the present invention is to provide a high-frequency heating device for a plastic tube that can be easily used as both a laminate tube and a plastic tube, and a high-frequency heating welding device including the same.

[0006]

In the first aspect of the present invention, in order to achieve the above object, a metal ring for heating an opening weld portion of a plastic tube is fitted to a support body, and the metal ring An induction heating coil for heating the metal ring is provided on the outer side in a state of being opposed to each other with a clearance interposed therebetween. The support body is fixed to the main cage via a coupling component, and a storage groove is formed on the outer periphery of the support body, and a temperature sensor for detecting the temperature of the metal ring is arranged in the storage groove. , The support body is provided with a discharge hole for discharging the gas generated from the inside of the plastic tube during heating to the outside,
It is preferable that a hole for feeding the gas corresponding to the discharged amount of the gas is bored in the joint part to feed the gas into the plastic tube. Further, the induction heating coil is formed in a ring shape, and an outer surface cooling portion for cooling the outer surface of the plastic tube near the opening welded portion is formed on the inner peripheral portion of the induction heating coil and the opening of the plastic tube is formed. A guide part for guiding the welded portion is formed, a cooling pipe is arranged on the outer periphery of the induction heating coil, the induction heating coil is housed in a coil case, and the coil case is fixed to a lower portion of the main cage. It is preferable. Further, in the second aspect of the present invention, in order to achieve the above object, a metal ring for heating the opening weld portion of the plastic tube is fitted to the support body, and the metal ring is attached to the outside of the metal ring. A high-frequency heating device for a plastic tube provided with induction heating coils facing each other through a clearance, and a press device for compressing and cooling an opening weld portion of the heated plastic tube downstream of the high-frequency heating device. I am trying to arrange.

[0007]

The first aspect of the present invention according to claim 1 having the above construction.
According to the invention of claim 1, when the opening weld of the plastic tube is positioned between the induction heating coil and the metal ring,
A high-frequency current is applied to the induction heating coil, and the induction heating coil generates magnetic lines of force, which act almost evenly around the entire circumference of the metal ring and cause the metal ring to generate heat. The inside of the opening weld is heated almost uniformly. According to the present invention as set forth in claim 2, the temperature of the metal ring is detected by the temperature sensor, and the temperature of the metal ring is controlled to a predetermined temperature based on the detected value. Further, when the opening weld portion of the plastic tube is heated, the plastic is melted and gas is generated from the inside of the opening weld portion.
If this gas is left as it is, it will adversely affect the contents, so it is necessary to discharge it before sealing.However, if other gas is not supplied according to the gas discharge amount, the plastic tube will be in a depressurized state. It becomes deformed, and the clearance with the metal ring becomes non-uniform, resulting in heating failure. However, according to the present invention, a gas corresponding to the discharged amount of gas, for example, clean air, is introduced from the outside into the inside of the plastic tube through the feeding hole and the feeding hole of the coupling component, so that the gas is , Clean air, etc. are exhausted to the outside through the discharge hole, and as a result, the depressurization inside the plastic tube and the adverse effects on the contents are prevented. Further, according to the present invention as set forth in claim 3, when the plastic tube is conveyed to the high-frequency heating device by a conveyor or the like and stopped, for example, the plastic tube ascends or relatively ascends, and the opening weld portion of the plastic tube is While being smoothly guided by the guide portion of the induction heating coil, the induction heating coil is positioned through the clearance between the induction heating coil and the metal ring. Further, when the opening welded part of the plastic tube is heated, the cooling medium such as a cooling liquid or gas flowing through the cooling pipe cools the induction heating coil, and the outer surface of the heated welded plastic tube is welded to the outer surface cooling part. To prevent the plastic tube from being deformed due to heating. Further, according to the second aspect of the present invention having the above-mentioned configuration, when the opening weld portion of the plastic tube is positioned between the induction heating coil and the metal ring, a high frequency current is applied to the induction heating coil. When energized, the induction heating coil generates lines of magnetic force, and the lines of magnetic force act almost evenly on the entire circumference of the metal ring to heat the metal ring,
The radiant heat of the metal ring heats the inside of the opening weld of the plastic tube substantially uniformly. When the heating of the opening welded portion of the plastic tube is completed in this way, the plastic tube is conveyed to the downstream press device by a conveyor or the like and stopped. Then, the opening weld portion of the plastic tube is hermetically welded by the pressing device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The high-frequency heating welding device equipped with the high-frequency heating device for the plastic tube in the present embodiment,
A high-frequency heating device 8 for heating the opening welding portion 1a of the plastic tube 1 and a press device 33 for compressing and cooling the heated opening welding portion 1a of the plastic tube 1 are provided, and the high-frequency heating device 8 and the pressing device 33 are high-speed. Each of the filling and sealing machines 5 is arranged.

As shown in FIGS. 1 and 2, the plastic tube 1 is formed into a slender hollow shape by a blow molding method or the like using plastic excluding aluminum foil as a main raw material, and one end which is the bottom thereof is substantially circular in a plane. Is formed as an opening welded portion 1a, and a cylindrical mouth portion 2 is projectingly provided at the center of the closed other end portion, and a cap 3 is detachably attached to the mouth portion 2. Has been done. The toothpaste 4 is filled and packaged inside the plastic tube 1 as described later. Further, the plastic tube 1 is held upside down in a vertically movable holder 7 of a conveyor 6 that constitutes the high-speed filling and sealing machine 5, and the opening welded portion 1a is arranged at a higher position.

The high-speed filling and sealing machine 5 is shown with a part thereof omitted, but the plastic tube 1 sequentially conveyed from the upstream (rightward in FIG. 2) by the conveyor 6 is cleaned in a clean process, and the downstream After filling the plastic tube 1 with the toothpaste 4 using the filling machine in the filling step, the plastic tube 1 is conveyed to the downstream positioning step. Then, in the downstream welding process, the high frequency heating device 8 is used to heat the opening welding part 1a of the plastic tube 1, and the pressing device 33 is used to compress and cool the opening welding part 1a of the plastic tube 1 to seal it. It has the function of completing the welding work, cutting the unnecessary part of the opening welded portion 1a of the plastic tube 1 in the downstream trimming process, and then discharging the commercialized plastic tube 1 from the downstream side (left direction in FIG. 2). ing.

On the other hand, the high-frequency heating device 8 adopts a synchronous instantaneous heating system, and as shown in FIG. 1, is composed of an expensive high-frequency generator 9 and a heating device part 10 which is a tool part. 10 is arranged right above the conveyor 6. The synchronous instantaneous heating method means the fitting timing of the opening welding portion 1a of the plastic tube 1 and the metal ring 2
5 is a method of substantially synchronizing the heating timing, and rapid heating is repeatedly performed in a short time, which is extremely effective for the plastic tube 1 from which the aluminum foil is excluded. The high-frequency generator 9 is the most expensive in terms of equipment cost among the high-frequency heating devices 8 and is not a new one. However, if there is no problem, a new high frequency generator 9 may be used. Furthermore, the heating device portion 10 is provided with a mounting portion 11 as shown in FIG. 1, a metal ring 25 is fitted to the mounting portion 11 via a support body 16, and the outer periphery of the metal ring 25 is attached to the mounting portion 11. Is provided with an induction heating coil 26.

As shown in FIG. 1, a columnar main cage 12 is hung from a plurality of bolts at the lower portion of the mounting portion 11 of the heating device section 10. The stepped portion is cut out. Mounting part 1
1 and the center of the main cage 12 have feeding holes 13 with different diameters.
・ 14 are provided so as to communicate with each other. The feeding holes 13 and 14 are a feeding hole 21 and a plurality of discharging holes 2 which will be described later.
2 and the discharge port 31 and the like, but these functions will be described in detail in the description of the operation. A cooling pipe 15 is wound around the outer circumference of the main cage 12 in a horizontal state, and a cooling liquid C flowing through the cooling pipe 15 (see FIG. 1).
(See the arrow in FIG. 3) acts to cool the heated main cage 12.

Further, as shown in FIG. 1, the support body 16 is composed of an upper support 17 and a lower support 18 which are fitted to each other in a plane circular shape.
The lower support 18 is made of a ceramic or the like having heat resistance and insulation that can withstand a high temperature of about 600 ° C. A mounting hole 19 is provided at the center of the support body 16.
Is provided in the vertical direction, and a fixing bolt 20 penetrating the mounting hole 19 is screwed into a feeding hole of the main cage 12 to fix the upper support 17 to the lower surface of the main cage 12. An elongated feeding hole 21 is provided at the center of the fixing bolt 20.
Is provided in the axial direction, and the feeding hole 21 and the main cage 12 are
Of the feeding holes 14 are communicated with each other. Further, the upper support 17 is formed in a substantially disk shape in plan view. In addition, the lower surface of the lower support 18 has a substantially hemispherical shape.
And these upper support 17 and lower support 1
8, a plurality of discharge holes 22 are provided so as to communicate with each other. Further, a ring-shaped storage groove 23 is formed by cutting out in the outer peripheral surface of the intermediate portion near the fitting surface of the upper support 17 and the lower support 18, and the storage groove 23 is formed.
A single temperature sensor 24 is arranged inside.

As shown in FIG. 1, the metal ring 25 is made of a nickel-chromium alloy or the like having a corrosion resistance capable of withstanding a high temperature of about 600 ° C., and has a heating width substantially equal to the heating width in the opening welded portion 1a of the plastic tube 1. The plate is formed to have the same plate width, and the plate thickness is as thin as 0.2 mm. And the storage groove 2 of the support body 16
It is fitted so as to cover 3 and is arranged in proximity to the temperature sensor 24, and acts so as to be loosely fitted into the opening welded portion 1a of the plastic tube 1 via a clearance.

Further, as shown in FIG. 1, the induction heating coil 26 is composed of a one-turn coil to be cooled in a ring shape, and has the same core as the metal ring 25 in the lower opening of the cylindrical coil case 27. It is stored and arranged through the clearance. Then, the induction heating coil 26 is disposed on the outer peripheral side of the support body 16 and the metal ring 25 with a clearance by fitting the opening upper part of the coil case 27 to the lower surface of the main retainer 12 and electrically. It has a function of causing the metal ring 25 to generate heat based on the energization action from the connected high frequency generator 9. On the inner peripheral surface of the induction heating coil 26, an outer surface cooling portion 28 that cools the outer surface of the opening welding portion 1a of the plastic tube 1 in a contact state is formed flat. At the lower end of the inner peripheral surface of the induction heating coil 26, a tapered skirt portion 29 having a diameter increasing toward the lower side is provided, and the skirt portion 29 guides and guides the opening welding portion 1a of the plastic tube 1. Further, the coil case 27 is configured to have a diameter larger than that of the induction heating coil 26, and the flange portion 3 is provided at the center of the inner peripheral surface thereof.
0 is provided so as to project inward in the radial direction, and the flange portion 30 is provided with a discharge port 31 connected to a vacuum device B (not shown). In addition, the coil case 27,
A cooling pipe 32 is pierced through, and the cooling pipe 32 is wound around the outer circumference of the induction heating coil 26 in a horizontal state. The cooling liquid C flowing through the cooling pipe 32 (see an arrow in FIG. 1) is an induction heating coil. 26 serves to constantly cool 26 and to cool the outer surface of the heated plastic tube 1 at the opening weld 1a. The magnitude of the high-frequency current supplied to the induction heating coil 26 and the duration of the high-frequency current are the main factors that cause the metal ring 25 to generate heat at a predetermined temperature. The energization time, in other words, the heating time in this embodiment is set to about 0.3 to 0.4 seconds. The frequency of the high-frequency current is effective from several tens of KHZ to several MHZ, and 100 KHZ to 300 KHZ is effective. However, it is not necessarily limited to these numerical values.

Further, as shown in FIG. 2 and FIG. 3, the press device 33 is almost the same as the existing equipment.
If there is no problem, a new device may be used. This press device 33 is provided with a pair of press jaws 34 that can be opened and closed in the direction of the arrow, and is arranged downstream of the high-frequency heating device 8, in other words, rearward, in an adjacent state, and directly above the conveyor 6. Functioning in conjunction with the high frequency heating device 8. The pair of press jaws 34 are cooled by a cooling device (not shown).

Next, the operation will be described. The plastic tube 1 is sequentially conveyed to the clean process from upstream by the conveyor 6 of the high-speed filling and sealing machine 5 to be cleaned, and then the toothpaste 4 is filled by the filling machine in the filling process, and then the positioning process is performed. Downstream high frequency heating device 8
Will be transported to and paused.

Then, the holder 7 rises in the direction of the arrow in FIG. 2, and the opening welding portion 1a of the plastic tube 1 is smoothly guided and guided by the skirt portion 29 of the induction heating coil 26, and the induction heating coil 26 and the metal ring 25. Is positioned with a slight clearance between them, and the end of the opening welded portion 1a of the plastic tube 1 is arranged near the lower edge of the discharge hole 22 of the support body 16. Next, the high-frequency generator 9 is energized, a large high-frequency current is applied to the induction heating coil 26, the induction heating coil 26 generates a large number of magnetic force lines, and the large number of magnetic force lines act uniformly on the entire circumference of the metal ring 25. Then, the metal ring 25 is rapidly heated to about 600 ° C., and the radiant heat of the metal ring 25 uniformly heats the inner surface of the plastic tube 1 at the opening welded portion 1a.

When heating the metal ring 25,
The heating efficiency increases as the metal ring 25 is brought closer to the opening welded portion 1a of the plastic tube 1, but when the metal ring 25 is brought into contact with the opening welded portion 1a of the plastic tube 1, various adverse effects occur. Therefore, it is desirable that the clearance between the metal ring 25 and the opening welded portion 1a of the plastic tube 1 be set and secured to be at least 0.5 mm, effectively around 1 mm.
However, it is not necessarily limited to this numerical value.

In the above-mentioned state, the opening welded portion 1a of the plastic tube 1 is heated. The temperature of the metal ring 25 at this time is detected by the temperature sensor 24, and the high frequency generator is generated based on the detected value. 9 is controlled so that the high frequency generator 9 maintains the temperature of the metal ring 25 at a predetermined temperature.
to manage.

By the way, when the opening welded portion 1a of the plastic tube 1 is heated, the plastic is semi-melted, and some gas generated by vaporizing the plastic is generated from the inner surface of the opening welded portion 1a. If this gas is left as it is, it will have an adverse effect on the toothpaste 4, so it is necessary to discharge it before sealing. However, if the gas corresponding to the discharge amount of gas is not fed, the plastic tube 1 Becomes deformed under reduced pressure, and the clearance with the metal ring 25 becomes non-uniform, resulting in heating failure. Therefore, in the present embodiment, clean air A corresponding to the amount of discharged gas is supplied from the outside to the feed hole 13 of the mounting portion 11, the feed hole 14 of the main cage 12, and the feed hole 21 of the fixing bolt 20. It is introduced into the inside of the plastic tube 1 sequentially. By doing so, the gas is discharged from the plurality of discharge holes 22 to the discharge port 31 together with the clean air A as shown by the arrow in FIG.
The vacuum device B is evacuated to the vacuum device B (see the arrow in FIG. 1) without any trouble. Therefore, the plastic tube 1
It is possible to prevent depressurization of the inside and adverse effects on the toothpaste 4. It should be noted that the balance control between the exhaust amount of gas and the supply amount of clean air A is extremely important for obtaining stable heating. This is because, for example, if the supply amount of the clean air A is too large, the clean air A leaks to the outside through the clearance between the plastic tube 1 and the metal ring 25, resulting in poor heating.

Further, when the opening welded portion 1a of the plastic tube 1 is heated, the cooling liquid C flowing through the cooling pipe 32.
Cools the induction heating coil 26 and cools the outer surface of the heated welded portion 1a of the plastic tube 1 via the outer surface cooling portion 28 to prevent deformation of the plastic tube 1 due to heating.

Thus, when the heating of the opening welded portion 1a of the plastic tube 1 is completed (at the same time, the temperature of the metal ring 25 is also rapidly lowered), the plastic tube 1 is moved to its original position as the holder 7 is lowered. Then, the conveyor 6 is intermittently conveyed to the downstream press device 33 by the conveyor 6 and temporarily stopped. Then, the opening welded portion 1a of the plastic tube 1 is compressed and cooled in a state of being sandwiched between the pair of press jaws 34, hermetically welded, and then conveyed downstream by the conveyor 6. Hereinafter, the above operation is repeated according to the number of the plastic tubes 1.

According to the above construction, the existing high-frequency generator 9 and the press machine 33, which are the most expensive in terms of equipment cost, can be used almost as they are, and the heating device part 10 as the tool part can be simply replaced with the structure described above. So good
There is no need to make a large capital investment and replace the entire facility. Therefore, it is possible to provide an inexpensive, high-speed, high-performance high-frequency heating apparatus and a high-frequency heating welding apparatus that can be applied to the plastic tube 1 from which the aluminum foil is excluded. Further, it can be used extremely easily for both the laminate tube and the plastic tube 1.

Further, the cooling liquid C flowing through the cooling pipe 15
Since the heated main cage 12 is cooled, it is possible to reliably prevent damage to the main cage 12 due to heating.
Further, since the clean air A corresponding to the discharged gas is introduced into the plastic tube 1, it is possible to reliably prevent the clearance from becoming non-uniform and the heating failure due to the pressure reduction inside the plastic tube 1. be able to. Further, since the support body 16 is composed of the upper support 17 and the lower support 18, it is expected that the disassembling and assembling and the maintenance will be significantly facilitated. In addition, the temperature of the metal ring 25 that is repeatedly heated is measured by the temperature sensor 2.
4 can be easily detected, so the high frequency generator 9
Control to maintain the temperature of the metal ring 25 at a predetermined temperature.
It is easy to manage. And the induction heating coil 2
Since 6 is housed and arranged so as to have the same core as the metal ring 25, a large number of magnetic lines of force act uniformly on the entire circumference of the metal ring 25, and as a result, the inner surface of the plastic tube 1 at the opening welded portion 1a is made uniform. It can be heated.
Further, since the skirt portion 29 of the induction heating coil 26 smoothly guides and guides the opening welding portion 1a of the plastic tube 1, it is expected that the plastic tube 1 can be loosely fitted and positioned remarkably easily. Furthermore, since the cooling liquid C flowing through the cooling pipe 32 cools the outer surface of the heated welded portion 1a of the plastic tube 1,
It is possible to reliably prevent deformation of the plastic tube 1 due to heating.

Although the plastic tube 1 is merely shown in the above embodiment, the size, shape, structure, material, etc. of the plastic tube 1 and the opening welded portion 1a may be appropriately increased or decreased according to the necessity. Is possible. In addition, the high-frequency heating welding apparatus in the above-described embodiment can obtain particularly good results when used in a package that is welded in the transverse direction in the opening area. The contents packed in the plastic tube 1 are toothpaste 4
It is needless to say that the present invention is not limited to the above, and may be, for example, a seasoning, a drug, a luxury item, a food, or a beverage. Further, the working process, structure, etc. of the high-speed filling and sealing machine 5 can be appropriately changed according to the necessity. For example, a marking process or its mechanism may be added, or the high frequency heating device 8 may be moved up and down instead of the holder 7.

Further, although the synchronous instantaneous heating method is shown in the above embodiment, the immediately preceding instantaneous heating method or the continuous heating method may be adopted. Here, the immediately-preceding instantaneous heating method is a method of ending the heating timing of the metal ring 25 immediately before the fitting timing of the opening welded portion 1a of the plastic tube 1. This immediately-preceding instantaneous heating method is effective for both the plastic tube in which aluminum foil is laminated and the plastic tube 1 in which aluminum foil is excluded. On the other hand, the continuous heating method refers to a method in which the metal ring 25 is continuously heated and constantly maintained at a constant temperature. This continuous heating method is effective for the plastic tube 1 excluding the aluminum foil, and the rated output of the high frequency generator 9 can be small. Therefore, it is extremely advantageous when introducing new equipment.

Further, the material and shape of the support body 16, the type and shape of the connecting part composed of the fixing bolt 20, and the feeding hole 2
1, the shape and number of the discharge holes 22, the shape and structure of the storage groove 23,
Alternatively, the location, type, number, etc. of the temperature sensor 24 can be increased or decreased as appropriate according to the need. In addition, a metal ring 25, which is a heating element, and an induction heating coil 26.
The shape of may be appropriately changed according to the shape of the opening welded portion 1a of the plastic tube 1, for example, an elliptical shape, an oval shape, a polygonal shape, a frame shape, or a combination thereof. Further, instead of the clean air A, a necessary gas such as nitrogen gas may be introduced into the plastic tube 1 and used for deactivating the plastic tube 1 after hermetically welding.

[0029]

As described above, according to the present invention, the existing expensive high frequency generator and press machine can be used as they are,
Since it suffices to replace and remodel the heating device part, which is the tool part, it becomes possible to eliminate the need to invest a large amount of equipment and replace the entire equipment. Therefore, it is possible to provide an inexpensive and high-performance high-frequency heating device that can be applied to a plastic tube excluding aluminum foil. Further, there is a special effect that it can be easily used for both a laminated tube and a plastic tube. According to the invention of claim 2,
It is possible to prevent heating failure due to depressurization inside the plastic tube. Moreover, since the temperature of the metal ring can be easily detected by the temperature sensor, the temperature of the metal ring can be easily controlled to a predetermined temperature.
Further, according to the present invention as set forth in claim 3, since the guide portion of the induction heating coil guides the opening weld portion of the plastic tube, it is expected that the positioning of the plastic tube can be facilitated. Further, since the cooling medium such as the cooling liquid flowing through the cooling pipe cools the outer surface of the heated plastic tube in the vicinity of the welded opening, deformation of the plastic tube due to heating can be prevented. Further, according to the present invention as set forth in claim 4, since it is sufficient to use the existing expensive high-frequency generator and press device almost as they are and to replace and modify the heating device part which is the tool part, a large amount of capital investment is required. Thus eliminating the need to replace the entire facility. Therefore, it is possible to provide a high-frequency heating and welding apparatus that is applicable to a plastic tube excluding aluminum foil and that is equipped with a high-frequency heating apparatus that is inexpensive and has high performance. Further, it can be easily used for both a laminated tube and a plastic tube. Furthermore, there is a remarkable effect that the opening welded portion of the plastic tube can be compressed / cooled and firmly sealed and welded.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a high-frequency heating apparatus for plastic tubes and a high-frequency heating welding apparatus including the same according to the present invention.

FIG. 2 is an overall explanatory view showing an embodiment of a high-frequency heating apparatus for plastic tubes and a high-frequency heating welding apparatus including the same according to the present invention.

FIG. 3 is a cross-sectional view showing an embodiment of a high-frequency heating apparatus for plastic tubes and a high-frequency heating welding apparatus including the same according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Plastic tube 1a ... Opening welding part 8 ... High frequency heating device 9 ... High frequency generator 10 ... Heating device part 11 ... Attachment part 12 ... Main retainer 13,14,21 ... Feed hole 16 ... Support body 20 ... Fixing bolt (Coupling parts) 22 ... Discharge hole 23 ... Storage groove 24 ... Temperature sensor 25 ... Metal ring 26 ... Induction heating coil 28 ... Outer surface cooling part 29 ... Skirt part (guide part) 32 ... Cooling pipe 33 ... Press device 34 ... Press chin A: Clean air (gas)

Claims (4)

[Claims] 1. A metal ring for heating an opening weld portion of a plastic tube is fitted on a support body, and an induction heating coil for heating the metal ring is provided outside the metal ring in a state of being opposed to each other via a clearance. A high-frequency heating device for plastic tubes characterized by being provided. 2. A temperature sensor for fixing the support body to a main cage via a coupling component, and forming a storage groove on the outer periphery of the support body, and detecting the temperature of the metal ring in the storage groove. The support member is provided with a discharge hole for discharging the gas generated from the inside of the plastic tube during heating to the outside, and the coupling component is
2. The high-frequency heating device for a plastic tube according to claim 1, further comprising a feed hole for feeding a gas corresponding to the discharged amount of the gas into the plastic tube. 3. The induction heating coil is formed in a ring shape, and an outer surface cooling portion for cooling an outer surface of the plastic tube near an opening weld portion is formed on an inner peripheral portion of the induction heating coil and the plastic A guide part for guiding the opening welded part of the tube is formed, a cooling pipe is arranged on the outer periphery of the induction heating coil, and the induction heating coil is housed in a coil case, and the coil case is placed under the main cage. The high-frequency heating device for a plastic tube according to claim 1 or 2, wherein the high-frequency heating device is a plastic tube. 4. A metal ring for heating an opening weld portion of a plastic tube is fitted to the support body, and an induction heating coil for heating the metal ring is provided outside the metal ring in a state of being opposed to each other via a clearance. A high-frequency heating device for a plastic tube, comprising: a high-frequency heating device for the provided plastic tube; and a press device for compressing and cooling the opening welded part of the heated plastic tube is provided downstream of the high-frequency heating device. High frequency heating and welding equipment equipped with.