JP4367776B2 - Metal can heating device - Google Patents

Description

The present invention relates to a heating device for heating the empty cans of metal cans, such as a bottle-type can or three-piece cans, in particular, locally heated by high-frequency induction heating curl portion formed on the opening edge of the can The present invention relates to a metal can heating device.

For metal cans such as bottle-type cans and 3-piece cans, high-frequency induction heating is applied to the curled portion formed at the opening edge of the can and the tightening portion that tightens the bottom lid of the can. For example, the following Patent Documents 1 to 3 below are known in the art. That is, Patent Document 1 below discloses that the curled portion is heated twice by high-frequency induction heating in order to bond the heat seal lid to the curled portion of the opening edge of the can. In Patent Document 2 below, in order to omit the sealing compound of the can lid, after the can lid is wound around the can body, the winding portion is heated by high-frequency induction heating, so that the resin coating of the can lid is performed. It is disclosed that the layer is melted to improve the sealing performance of the tightening portion. Further, Patent Document 3 below discloses that the can is irradiated with ultraviolet rays in order to sterilize the winding portion of the empty can for aseptic filling. It is disclosed that the winding part is heat sterilized by high-frequency induction heating while irradiating with a laser beam.
Japanese Examined Patent Publication No. 62-18404 JP 2000-126836 A JP 59-15027 A

  By the way, in the case of trying to locally heat the curled part or the winding part of the metal can by high frequency induction heating, any of the conventionally known heating means disclosed in each of the above patent documents can be used for high frequency induction. Since the heating coil is directly opposed to the side of the curled part and the winding part, the heating of the metal can by the high-frequency induction heating coil affects the coating and coating of the neck and neck in the case of the curled part. In the case of a tightened part, it also affects the coating and coating of the body part, so that only the curled part and the tightened part are efficient without affecting other parts. Heating is difficult.

The present invention has an object to eliminate the above problem, specifically, the heating device of a metal can according to high-frequency induction heating, little without affecting the other portions, the portion of the curled portion It is an object to make it possible to efficiently heat only.

In order to solve the above problems, the present invention provides a heating device for heating the curled portion of the opening edge of the can by high frequency induction heating, with respect to an empty can positioned by an insulating holder, A magnetic flux generating coil is installed concentrically with the can above the curl portion of the can, and a flat ring-shaped insulating plate is installed below the magnetic flux generating coil. With the flat ring-shaped copper disc having the same thickness as the width sandwiched between the insulating holder and the insulating plate, the inner surface of the copper disc faces the curl of the can from the outside . It is characterized by being installed as follows.

  According to the metal can heating apparatus of the present invention as described above, when the curled portion of the empty can is heated by high frequency induction heating, magnetic flux is generated in the copper disk due to the alternating current in the magnetic flux generating coil. This magnetic flux generates an induced current that flows in the circumferential direction at the curled portion facing the copper disk, and the metal of the curled portion rises in temperature, and the disk is made of copper. The penetration depth of the high-frequency current is shallower than when ferrite is used, and an induced current is generated on the surface of the disk. Only the curled portion can be efficiently heated without exerting any effect.

The heating device of a metal can according to high-frequency induction heating, particularly almost without affecting the other parts, the objective of allowing heat only portions of the curled portion effectively, in the following examples as the best mode As shown in the figure, as a heating device for heating the curled portion of the opening edge of the can by high frequency induction heating, the can is positioned above the curled portion of the can with respect to the empty can positioned by the insulating holder. A magnetic flux generating coil is installed concentrically, a flat ring-shaped insulating plate is installed below the magnetic flux generating coil, and a flat plate having a thickness substantially equal to the vertical width of the curl portion of the can is provided below the insulating plate. Realized by installing a ring-shaped copper disc sandwiched between an insulating holder and an insulating plate so that the inner surface of the copper disc faces the curl of the can from the outside . .

  Hereinafter, one embodiment of a heating apparatus for a metal can according to the present invention will be described. The heating apparatus of this embodiment preheats each of a curled portion and a winding portion of an empty can of a bottle type can used in an aseptic filling method. Because it is for sterilization, simply sterilizing an empty can with sterilizing liquid such as oxonia or ultraviolet rays, it is difficult to sterilize well inside the curl part of the can and the inside of the tightening part, About such a part, it is for heating-sterilizing only the said part locally by high frequency induction heating.

  In such a heating apparatus of the present embodiment, as shown in FIG. 1, the empty bottle-shaped can 2 is arranged so that the center axis of the can 2 and the center axis of the apparatus 1 coincide with the heating apparatus 1. In the state of being positioned and standing upright, the upper holder 3 and the lower holder 4 made of an electrically insulating resin material are fixedly held.

  The upper holder 3 is formed in a cylindrical shape with a large wall thickness, and has an upper end surface that is a flat surface and a lower end surface that follows the shoulder of the can 2. Further, as shown in FIG. 3, the lower holder 4 is integrally formed with a thin plate ring portion 4b having a thickness of about 1 mm inside from the lower end of the cylindrical portion 4a. The upper inner surface is in contact with the lower end portion of the body portion of the can, and the thin flat ring portion 4b extending inward from the lower end of the cylindrical portion 4a is placed on the winding fastening portion 2b of the can 2 thereon. It has become.

  In contrast to the empty bottle-shaped can 2 that is fixedly held in an upright state by the upper holder 3 and the lower holder 4 as described above, in the heating apparatus 1 of this embodiment, as shown in FIG. High-frequency induction heating means 5 for heating and sterilizing the curled portion of the opening edge (ie, the outer curled portion formed at the upper end opening edge of the mouth and neck portion of the can) and the winding of the bottom lid of the can 2 High-frequency induction heating means 6 are provided for heating and sterilizing the fastening portion (that is, the fastening portion in which the lower end flange portion of the can body and the peripheral flange portion of the bottom lid are double-tightened) 2b.

  The high frequency induction heating means 5 for heat sterilizing the curled portion 2a of the can 2 includes a magnetic flux generating coil 10 surrounded on three sides by an electrically insulating resin core 11 and two ferrite rings 12. And a flat ring-shaped copper disc 13 having a thickness substantially the same as the vertical width of the curled portion 2a, and a flat ring-shaped silicon plate between the magnetic flux generating coil 10 and the copper disc 13 14 is sandwiched as an insulating plate, and the core 11 and the ferrite ring 12 are covered with an electrically insulating resin case member 15 from above, and the entire periphery thereof is covered with a vinyl chloride cover member 16. The cover member 16 is covered with a case member by a bolt or the like with a silicon rubber flat ring 17 interposed between the folded portion at the lower end of the cover member 16 and the peripheral portion of the copper disc 13. It is integrally fixed to the 5.

  The flat ring-shaped copper disc 13 is integrally connected by screwing while being concentrically placed on the upper end surface of the substantially cylindrical upper holder 3, and the upper surface of the copper disc 13 is flat. As shown in FIG. 2, the inner surface of the copper disk 13 that is covered with the ring-shaped silicon plate 14 and exposed between the upper holder 3 and the silicon plate 14 is in contact with the curled portion 2 a of the can 2. The curl portion 2a is confronted with the curl portion 2a in a state of being close to the curl portion 2a. As shown in FIG. 1, an annular copper pipe 18 for circulating cooling water is installed on the lower surface side of the copper disk 13 and outside the upper holder 3 while being covered with an insulator. Has been.

  On the upper side of the silicon plate 14 covering the upper surface of the copper disk 13, the magnetic flux generating coil 10 is installed in a state surrounded by a resin core 11 and two ferrite rings 12, but two The inner surface of the ferrite ring 12 is positioned outside the outer surface of the mouth and neck of the can 2 so that the magnetic flux from the ferrite ring 12 does not directly reach the mouth and neck of the can 2.

  The center portion of the case member 15 of the high-frequency induction heating means 5 for the curled portion 2 a configured as described above is fixed to the rod 8 a of the air cylinder 8. When the can 2 is put into and out of the heating apparatus 1 by an appropriate means (not shown) fixed to the beam 7a, the entire high-frequency induction heating means 5 is moved by the expansion and contraction of the rod 8a of the air cylinder 8. Together with the integrally connected upper holder 3, it can be moved up and down to the position indicated by the one-dot chain line in FIG. 1.

  As for the high frequency induction heating means 6 for heat sterilizing the winding portion 2b of the can 2, a magnetic flux generating coil 20 surrounded on three sides by an electrically insulating resin core 21 and two ferrite rings 22 is provided. And a secondary coil 30 for generating a magnetic flux by the current in the magnetic flux generating coil 20, and the secondary coil 30 is provided with a flat ring-shaped copper plate 23 on the lower side thereof, A ferrite ring 29 is provided (inside the secondary coil 30 and the copper plate 23), and the lower side of the copper plate 23 and the ferrite ring 29 is covered with a disk-shaped silicon plate 24 serving as an insulating plate.

  The core 21 and the ferrite ring 22 surrounding the magnetic flux generating coil 20 are covered from below with an electrically insulating resin case member 25, and the entire periphery thereof is covered with a vinyl chloride cover member 26. The cover member 26 is integrally fixed to the case member 25 with bolts or the like in a state in which a flat plate ring 27 made of silicon rubber is sandwiched between the folded portion at the upper end of the cover member 26 and the peripheral portion of the copper disk 23. ing.

  The secondary coil 30 provided with the copper plate 23 and the ferrite ring 29 on the lower side and the inner side is installed above the magnetic flux generating coil 20 with a disc-shaped silicon plate 24 sandwiched between them as an insulating plate. As shown in FIG. 3, the secondary coil 30 does not come into contact with the winding portion 2b between the lower holder 4 and the silicon plate 24 on which the winding portion 2b of the can 2 is placed and held. In this manner, the winding portion 2b is opposed to the winding portion 2b from the inside in a state of being close to the winding portion 2b. As shown in FIG. 1, an annular copper pipe 28 for circulating cooling water is installed outside the secondary coil 30 so as to be covered with an insulator.

  In the high-frequency induction heating means 6 for the tightening portion 2b configured as described above, the center portion of the case member 25 is fixed to the main body 9a of the support portion 9 with a bolt, and the main body 9a of the support portion 9 is provided. Is installed to be movable up and down with respect to the pedestal portion 7b of the machine frame 7 via the mounting portion 9b, and is always urged upward by a spring 9c interposed between the main body 9a and the support portion 9b. Has been. Thereby, the high-frequency induction heating means 6 is always held at a fixed position, and when receiving an impact from above, the high-frequency induction heating means 6 is slightly lowered against the urging force of the spring 9c so that the impact can be absorbed. After moving to, it immediately returns to its original position.

  As described above, the heating apparatus 1 according to this embodiment includes both the high-frequency induction heating means 5 for heat sterilizing the curled portion 2a and the high-frequency induction heating means 6 for heat sterilizing the winding portion 2b. According to the high frequency induction heating means 5 for heat sterilizing the curled portion 2a, when a 2 KW alternating current is passed through the magnetic flux generating coil 10 for about 2.5 seconds, the alternating current in the magnetic flux generating coil 10 is changed to a copper disc. 13, a magnetic flux is generated in the circumferential direction, whereby an induced current is generated in the circumferential direction in the curled portion 2a of the can 2 facing the copper disc 13, and the curled portion 2a is 170 to 200 ° C. The temperature will be increased.

  In addition, in such high-frequency induction heating of the curled portion 2a, since the disc 13 is made of copper, the penetration depth of the high-frequency current in the disc 13 becomes shallower than when a ferrite disc is used. The induced current is generated on the surface of the disk 13, and as a result, only the curled portion 2a is efficiently heat sterilized without affecting the coating or painting of the mouth and neck portion in the portion other than the curled portion 2a. can do.

  On the other hand, in the high-frequency induction heating means 6 for heating and sterilizing the winding portion 2b, when an alternating current of 2 kW is passed through the magnetic flux generating coil 20 for about 2.5 seconds, the alternating current in the magnetic flux generating coil 20 is converted into the secondary coil. 30 generates a magnetic flux in the circumferential direction, whereby an induced current is generated in the circumferential direction at the tightening portion 2b of the can 2 facing the secondary coil 30, and the tightening portion 2b becomes 170 to The temperature will rise to 210 ° C.

  In addition, in such high-frequency induction heating of the winding part 2b, the secondary coil 30 faces the winding part 2b from the inside, so that an induction current is generated from the inside to the winding part 2b. As a result, the temperature of the part 2b is increased from the bottom lid side, and as a result, only the tightening part 2b is efficiently heat sterilized without substantially affecting the coating film or the film of the body part other than the tightening part 2b. can do.

  In the heating device 1 of the present embodiment, the two high-frequency induction heating means 5 and 6 are provided in one device, so that the heating of the curled portion 2a and the winding portion 2b are simultaneously performed in one stroke. It can be carried out. Even if heating of the curled portion 2a and heating of the winding portion 2b are performed at the same time, each heating is induction heating that generates an induced current flowing locally and in the circumferential direction. There is no mutual contact, and both heating operations can be performed without problems.

As mentioned above, although one Example of the heating apparatus of the metal can of this invention was described, this invention is not limited only to the above Examples, For example, about the use, it is in said Example. It can be used not only for the heat sterilization as shown, but also for other uses that require local heating of the curled portion. When the curled portion of the can is heat sterilized by the apparatus of the present invention, after the heat sterilization by the apparatus of the present invention, the inner and outer surfaces of the can are further sterilized by a sterilization method using a sterilizing solution using a conventional oxonia or the like. Needless to say, you can.

In addition, the metal can to be heated is not limited to the bottle-type can as shown in the above embodiment, but may be other types of metal cans, and the entire structure of the heating device for, in the above embodiment, both the high-frequency induction heating means for heating the curling unit, provided with a high-frequency induction heating means for heating the seamed portion, although the hotel structure in one unit, such Needless to say, the high-frequency induction heating means for heating the tightening portion may be omitted as appropriate, and may be omitted.

The longitudinal cross-sectional view which shows one Example of the heating apparatus of the metal can of this invention. The longitudinal cross-sectional view which expands and shows the vicinity of the copper disk of the heating apparatus shown in FIG. The longitudinal cross-sectional view which expands and shows the vicinity of the secondary coil of the heating apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating device 2 Can 2a Curl part 2b (Can) winding part 3 Upper holder 4 Lower holder 10 Magnetic flux generating coil 13 Copper disk 14 Insulating board 20 Magnetic flux generating coil 24 Insulating board 30 Secondary coil

Claims (1)

As a heating device for heating the curled portion of the opening edge of the can by high frequency induction heating, magnetic flux is generated concentrically with the can above the curled portion of the can with respect to an empty can positioned by an insulating holder A coil is installed, a flat ring-shaped insulating plate is installed below the magnetic flux generating coil, and a flat plate ring-shaped copper disc having a thickness substantially the same as the vertical width of the curl portion of the can under the insulating plate However, the metal can is heated in such a manner that the inner surface of the copper disk faces the curled portion of the can from the outside while being sandwiched between the insulating holder and the insulating plate. apparatus.

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