JP3306699B2 - Heating device for seaming part of metal can - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heating a crimped joint (hereinafter simply referred to as a seaming portion) of a metal can formed of a laminated steel sheet to fuse laminated films overlapping on the inner surface of the seaming portion. Accordingly, the present invention relates to a seaming portion heating device for a metal can for improving the sealing property of the seaming portion.

[0002]

2. Description of the Related Art For example, Japanese Patent Publication No. 5-132061 discloses a method of manufacturing a metal can using a laminated steel sheet as a material. Japanese Utility Model Publication No. 3-7054 discloses a heating device for a seaming portion related to the present invention. However,
This heating device is a heating device for heating the adhesive previously sealed in the inner surface of the seaming portion to cause a crosslinking reaction. There, there is a pre-heating section for heating the seaming portion of the canopy and the can body and the bottom lid and the can body, and a post-heating section for heating the seaming portion of the can body peripheral surface, and the heating is performed in the pre-heating section. A cooling transport line for allowing the heat of the seaming section to cool to room temperature, and connects both heating sections in the front and rear stages. In the former heating section, the metal can is rolled in the circumferential direction of the canopy and the bottom lid, and each side of the square is heated twice by the high-frequency heating coil. In the latter heating section, the seaming portion of the can body is slid and fed along a linear heating rail, and is heated by a high-frequency heating coil embedded in the heating rail.

[0003] The metal can is intermittently fed in a vertically upright posture, and while the feeding operation is stopped, the canopy and the can body and the seaming portion between the bottom lid and the can body are heated at a stroke. An apparatus is known from Japanese Patent Publication No. 62-55275. Moreover, the metal can in the sideways asked to support, apparatus for heating an seaming portion of the can body located at the lowest portion in this state at a high frequency heating coil is known in Japanese Unexamined Utility Model Publication No. 53-39151. These heating devices also heat the adhesive in the same manner as the previous heating device. In this type of heating device, the seaming part is
Heat to 00-220 ° C and keep that state for about 10 seconds.

[0004]

Even in a metal can formed of a laminated steel sheet, if the seaming portion is heat-treated with the above-described conventional apparatus, a sufficient sealing effect should be obtained as long as the heating conditions are appropriate. Yes. However, when a test operation was actually performed to perform a durability test on metal cans, the liquid stored in some metal cans leaked from the seaming part, or corroded storage parts corroded the seaming part. Occurred.

[0005] As a result of investigating the cause of such a liquid leak or the like, as a result of the overlap between the canopy and the can lid or the bottom lid and the seaming portion of the can trunk, and the seaming portion of the can trunk (hereinafter referred to as a multiple joint portion), It was found that a bad seal had occurred. Specifically, when disassembling the multi-joint, the film on the inner surface of the canopy or bottom lid and the film on the inner surface of the can body are not sufficiently fused, and the area where the fusion should be performed A plurality of fine holes were observed. The same defective fusion was found in the metal can immediately after the test operation.

[0006] Since such defective fusion occurs at the multiple junctions, it is understood that sufficient heat is applied to the other heating sections, but sufficient heat is not transmitted to the multiple junctions. . In order to avoid such a situation, it is easy to raise the heating temperature.However, even if the heating temperature of the multi-junction can be adjusted appropriately, the other seaming part cannot be prevented from being overheated. As a result, defects such as defective sealing due to the flow of the molten film resin occur, and the sealing performance of the entire seaming portion is reduced.

An object of the present invention is to provide a heating device capable of properly heating a multi-joint portion similarly to other seaming portions and securely sealing the inner surface of the multi-joint portion. An object of the present invention is to manufacture a highly reliable metal can that does not cause leakage or internal corrosion.

[0008]

The heating device according to the present invention comprises:
Focusing on the fact that the seaming part on the lid side and the seaming part on the can body side are each heated by separate heating devices, with a moderate amount of residual heat remaining in the multiple joints heated by the preceding heating device By reheating the multiple joints by a heating device at a later stage, the multiple joints can be appropriately heated without causing other seaming portions to be overheated.

That is, the apparatus for heating the seaming portion of the present invention comprises the can 2 of the metal can C and the can body 1, and the bottom cover 3 and the can body 1.
<Br of each seaming portion S2 · S3, and a previous lid heater 5 for heating in a state where the metal can C in the upright position, the subsequent heating in a state that the seaming portion S1 of the can body 1 has been laterally recumbent posture The body heating device 7 and the metal can C fed from the lid heating device 5
And a posture change device 6 for feeding are arranged in a straight line with attitude change to cylinder heating device 7.

[0010] Lid heating device 5 and the intermittent feed Kyusuru can sending mechanism 10 at a predetermined pitch to hold gold Shokukan C in an upright position and placed above and below the can feed stop position adjacent to the conveying direction, the bottom lid And a heating unit for the canopy. Both heating units include a heating coil 20 fixedly supported in a fixed position and a metal can C
And an operation cylinder 21 that performs an approach operation toward the vehicle.
The body heating device 7 includes a guide frame 40 that supports the metal can C in the reclined position, a feed mechanism 41 that performs a feeding operation of the metal can C along the guide frame 40, and a movement trajectory of the seaming portion S1 of the can body 1. And a heating coil 42 arranged in a vertical direction.

[0011] posture conversion apparatus 6 includes a rollover mechanism 23 for operating the overturning shape along the metal can C which is fed from the cover heating device 5 in the conveying direction, a roll metal cans C around the can center axis Lying down to match the heating posture of the body heating device 2 by turning the body
And a turning mechanism 24 for displacing the posture . Hide
And the seaming portions S2 and S3 of the lids 2 and 3 and the can body 1
At the multiple junction W where the upper and lower ends of the seaming portion S1 overlap
With the residual heat at a constant temperature remaining , the metal can C is moved to the posture changing device 6.
And feeds it to the body heating device 7.

The heating coils 20 of the lid heating device 5 are each constituted by a high-frequency induction coil,
The portion 20a corresponding to the multiple junction W of 0 can be provided at a position farther from the seaming portions S2 and S3 than other coil portions.

[0013]

[Action] Since the cover heating device 5 is provided in the preceding stage, the metal cans C after the seaming portion S2 · S3 canopy 2 and the bottom lid 3 is heated, the attitude changed in cylinder heating apparatus in the posture change device 6 Transferred to 7. Since a certain amount of time is required for this posture change and transfer, the temperature of each of the seaming portions S2 and S3 is lowered by natural cooling before reaching the body heating device 7. If the residual heat temperature of the multiple joining portion W at this time is equal to or higher than a predetermined value, when the seaming portion S1 of the can body 1 is heated by the body heating device 7, the multiple joining portion W is reheated to a sufficient temperature,
Adjacent films can be reliably fused on the inner surface. In other words, while the multiple joint portion W has sufficient residual heat, the attitude of the metal can C is changed so that the two heating devices 5 and 7 can be quickly sent to the body heating device 7 by the attitude changing device 6. Will be connected.

Disposing the lid heating device 5, the posture changing device 6, and the body heating device 7 in a straight line may also shorten the path length of the posture changing device 6 and make the two heating devices 5 in the front and rear stages. 7 is connected at the shortest distance to help speed up the feeding of metal cans C. Basically, the temperature of the multiple junction W after being heated is lower than that of the other seaming parts S2 and S3.
However, when the ambient temperature of the heating device is high, the residual heat temperature of the multiple junction W may be higher than necessary. In such a case, in order to set the residual heat temperature of the multiple junction W to an appropriate state, the portion 20a of the heating coil 20 corresponding to the multiple junction W is formed with a seaming portion S2 · S
3 to prevent the multiple matching portion W from being heated more than necessary.

[0015]

1 to 10 show an embodiment of a seaming portion heating apparatus according to the present invention. Metal can C to be heated
Is a rectangular cylinder-shaped can body 1 vertically long as shown in FIG.
A canopy 2 and a bottom lid 3 which are fastened and fixed to the upper and lower ends of a can body 1
This is a square can with an internal capacity of 18 liters. The can body 1 and the lids 2 and 3 are each made of a laminated steel sheet, and the laminated films are respectively located on the inner surface side of the can. The seaming portion provided at the corner of the can body 1 is denoted by reference numeral S1, and the seaming portions of the canopy 2 and the bottom lid 3 are denoted by reference numerals S2 and S3. Further, each seaming section S
The multiple junction where 1 · S2 · S3 overlaps is indicated by the symbol W.

The metal can C is fed to a heating device to heat-treat each of the seaming portions S1 to S3 to fuse the films on the inner surface. In FIG. 1, the heating device is configured such that the metal can C is in an upright posture, and the seaming portions S2.
A lid heating device 5 for heating S3, a posture changing device 6 for feeding the metal can C fed from the lid heating device 5 while changing the posture to a rear body heating device 7, and a metal can C having a rhombic cross section. A body heating device 7 for heating the seaming portion S1 of the can body 1 in the reclined position.

(Lid Heating Device) The lid heating device 5 includes a can feeding mechanism 10 for holding two metal cans C in an upright posture and intermittently feeding the metal cans C at a constant pitch, and a can feeding mechanism at a can feeding stop position adjacent to the feeding direction. Arranged at the top and bottom,
It comprises a heating unit for the bottom lid 3, a heating unit for the canopy 2, and the like. These devices are provided in two rows on the left and right along the transport direction so that the metal can C can be processed in accordance with the processing capacity of the body heating device 7 (see FIG. 2).

In FIG. 2, the can feeding mechanism 10 is a metal can C
A pair of left and right slide bases 11 slidably supported by the machine base in the transfer direction, a receiving frame 12 and a holding frame 13 disposed opposite to both slide bases 11, and both slide bases 11;
Is constituted by a crank arm 16 which reciprocates and slides via an interlocking frame 14 and a transmission rod 15. The presser frame 13 is reciprocated by the operation cylinder 17, and the metal can C
Is co-operated with the receiving frame 12 and fixed to the left and right. The crank arm 16 is driven to rotate in one direction and the slide table 1 is rotated.
Operate 1 back and forth. In order to absorb unnecessary motion components of the crank arm 16, the interlocking frame 14 is provided with a long hole 18 which engages with a drive pin. It should be noted that the can feed mechanism 0 arranged side by side has a phase position of 18 for each crank arm 16.
The two crank arms 16 are driven synchronously in a state of being shifted by 0 degrees.

FIG. 3 shows the seaming portions S2, S of the lids 2, 3.
3 shows a heating unit for heating 3. The heating unit includes a heating coil 20 fixed to a fixed position facing each of the lids 2 and 3.
And an operation cylinder 21 for pressing the metal can C toward the heating coil 20. The heating coil 20 and the operation cylinder 21 are opposed to each other above and below a can-feed stop position adjacent to the metal can C in the transport direction. Are located in The heating coil 20 is a high-frequency induction coil, and a copper conductor 20b is provided inside a plastic square frame-shaped insulating frame 20a.
Is formed by embedding. At the time of heating, the metal can C is pressed by the operation cylinder 21 so that the vertically tightened edges of the bottom lid 3 and the canopy 2 are separated from each other by the insulating frame 20a.
, And a high-frequency current is applied to the current-carrying body 20b while maintaining this state.

As described above, since the lid heating line is provided in two rows, the lid heating device 5 has a total of four heating coils 2.
0 is placed. These four heating coils 20 can reduce the power supply capacity by alternately energizing between the adjacent lid heating lines in a cascading manner.

(Posture Changer) FIGS. 4 to 7 show the posture changer 6. Lid heating device 5
The metal cans C subjected to the heat treatment in are sent out alternately from the respective lid heating lines. A set mechanism 22 to align these metal cans C in a row, a rollover mechanism 23 for overturning operated along the metal can C in an upright posture to the conveying direction, to turn operates the rollover metal cans C around the can center axis The turning mechanism 24 forms the posture changing device 6.

In FIG. 4, the collecting mechanism 22 includes an alignment section having a pair of belt conveyors 27 arranged on the upper surface of a roller conveyor 26, and a transfer conveyor 2 provided continuously to the alignment section.
8 The former conveyor 27 is arranged in a C-shape which is tapered toward the transport direction, and sends the metal cans C alternately sent from the lid heating device 5 to the transfer conveyor 28 while aligning them.

As shown in FIG. 5, the roll mechanism 23 has a chute 29 disposed adjacent to the rear end of the transfer conveyor 28 in the transport direction.
And a swing conveyor 30. The chute 29 receives the metal can C sent from the transfer conveyor 28 and shifts the metal can C while slightly falling toward the swing conveyor 30. The swing conveyor 30 is basically a belt conveyor, but the entire conveyor is swingably supported around a shaft 31 at the lower part of the conveyor. The metal can C can be fed into the turning mechanism 24 of the next stage by tilting the whole conveyor to a receiving position indicated by an imaginary line and a sending position indicated by a solid line by an operation cylinder (not shown).
In order to prevent the metal can C from dropping from the conveyor surface by its own weight during tilting, a magnet 3 is provided on the back side of the belt surface receiving the metal can C.
2 is arranged.

In FIG. 6, the turning device 24 includes a pair of belt conveyors 34 and 35 arranged in parallel along the conveying direction.
And an inclined conveyor 36 which is provided continuously to these belt conveyors 34 and 35 and transports the metal can C in the pre-rotation position, and is disposed adjacent to the end of the inclined conveyor 36,
The metal can C which is pre-turn composed of such a pusher 37 for raising operation-out collision.

The above-mentioned pair of belt conveyors 34 and 35
The metal can C received from the swing conveyor 30 is transported in a horizontal posture. However, the end of one belt conveyor 34 is provided adjacent to the inclined conveyor 36, while the other belt conveyor 35 is set shorter than the previous belt conveyor 34. Therefore, the latter belt conveyor 3
After passing through 5, the metal can C is supported by the former belt conveyor 34 and the roller conveyor, and is inclined to the pre-rotation position (the state shown by the solid line in FIG. 8). In this state, the metal can C is transferred onto the inclined conveyor 36 and transferred. On the back surface of the inclined conveyor 36, a magnet 38 for preventing the metal can C from falling due to its own weight is arranged over substantially the entire length of the transport path.

The pusher 37 is made from the operation cylinder, the piston rod 37a projecting operation, the attitude of FIG. 8 you fit the metal can C in the heating position of the cylinder heating apparatus 7, ingredients
Physically, the metal can C is turned with the pusher 37 so that the seaming portion S1 of the can body 1 is located at the lower corner.

(Body Heating Apparatus) FIGS. 7 to 9 show the body heating apparatus 7 and a metal can C
, Three sets of guide frames 40 that respectively support the left and right opposite corners, a feed mechanism 41 that shifts the metal can C along the guide frames 40, and along the shift trajectory of the seaming portion S1. And a heating coil 42 arranged linearly and a heat shield cover 43 covering the upper outer surface of the transition locus of the metal can C.

The three sets of guide frames 40 are formed of a pair of parallel guide rods, respectively, and guide the metal can C in a state in which the corners of each can enter between the pair of guide rods. Of the three sets of guide frames 40, the guide frame 40 on the side facing the pusher 37 and the guide rod on the side of the upper guide frame 40 facing the pusher 37 move the metal can C pushed up by the pusher 37. In order to receive it, it protrudes from the other guide frame 40 toward the inclined conveyor 36 (see FIG. 7).

The feed mechanism 41 is basically a chain conveyor. A feed claw 44 for moving the metal can C is mounted at regular intervals of the chain link, and the feed claw 44 is protruded toward the can transfer locus. I do. The rotation center axis of the drive sprocket of the chain conveyor is provided in parallel with the cylindrical flat wall on the lower surface side of the metal can C. As a result, the feed claw 44 comes into contact with the side on the lower surface side of the bottom lid 3 and moves the metal can C at a constant speed.

In FIG. 9, the heating coil 42 is composed of a high-frequency induction coil formed by burying a copper conductor 42b inside a plastic insulator 42a.
A high-frequency current is supplied to b, and the seaming portion S1 is heated by heat generated by the induction action. As described above, the metal can C supported by the three guide frames 40 is horizontally conveyed with the seaming portion S1 positioned at the lowermost end of the can peripheral surface. In this transport posture, as shown in FIG. 7, the multiple bonding portion W passes a position closer to the heating coil 42 than the seaming portion S1. Therefore, it is possible to more reliably heat the multiple junction W that is difficult to heat.

Although the entire contents of the seaming portion heating device are as described above, the most characteristic feature of the present invention is that the metal can C heated by the lid heating device 5 is supplied with sufficient residual heat at its multiple joint portion W. The remaining state is sent to the body heating device 7,
The point is that the multiple joint portion W, which is likely to be underheated, is heated to a sufficient temperature, and the laminated films on the inner surface thereof are surely fused together.

In the lid heating device 5, the seaming portions S2 and S
3 is heated to 160 ° C. and maintained in that state for about 2 seconds. As described above, when the heating time is extremely short and the amount of heat received is small, the temperature of the multiple junction W tends to decrease while the metal can C is transferred by the posture changing device 6. When the temperature is lowered to about room temperature, the inner surface temperature of the multiple bonding portion W cannot be raised to a predetermined temperature even if reheating is performed in the body heating device 7, and a fusion defect of the laminate film occurs.

In order to avoid such a situation, the metal can C is quickly rolled over by the posture changing device 6 and further turned around the central axis of the can to be fed into the body heating device 7. As a result of the experiment, in order to leave sufficient residual heat in the multiple joint W, the transfer time in the posture turning device 6 is set to room temperature (15 to 2).
It has been found that it is necessary to set the temperature to about 20 to 30 seconds at 0 ° C.) and to maintain the temperature of the multiple junction W at the entrance of the body heating device 7 within the range of 40 to 90 ° C. That is, all posture changes must be made within 20 to 30 seconds. As described above, in order to surely change the posture within a limited time, the three members of the lid heating device 5, the posture turning device 6, and the trunk heating device 7 are arranged in a linear row, and the heating devices 5 7 is shortened, and in the posture changing device 6, the rollover operation and the turning operation of the metal can C are continuously performed to speed up the posture change.

(Alternative Embodiment) As described with reference to FIG. 3, in the lid heating device 5, the lids 2.3 are pressed against the insulator 42a of each heating coil 20 to heat the seaming portions S2 and S3. . When the temperature of the working environment is near normal temperature, the multiple junction W can be appropriately heated by the heating coil 20. However, when the working environment temperature is high, even if the heating condition by the heating coil 20 is reduced, the residual heat temperature of the multiple junction W may be unnecessarily high. In such a case as well, in order to heat the multiple junction W to an appropriate temperature, as shown in FIG. 11, the portion 20a of the heating coil 20 corresponding to the multiple junction W is closer to the seaming portions S2 and S3 than the other coil portions. It can be provided at a position that goes away. More specifically, the corner portion of the current-carrying body 42b is bent toward the side away from each of the lids 2 and 3 at the portion 20a so as to reduce the field force acting on the multiple junction W.

In FIG. 12A, the heating coil 20 is
Heating can be performed in a state of circling around the seaming portions S2 and S3 of the lids 2 and 3. In this case, FIG.
As shown in (b), the corner portion 20a of the heating coil 20 facing the multi-joint portion W is closer to the seaming portions S2 and S3 than the other coil portions, and the multi-joint portion W is connected to another seam portion. Heating can be performed to a temperature approaching the heating temperature.

The arrangement of the heating coil 20 can be changed as shown in FIG. There, the heating coil 20 is
And, it is arranged along the inner surfaces of the seaming portions S2 and S3 of the bottom lid 3 so that the seaming portions S2 and S3 can be heated at a position close to the inner corner G between each lid 2.3 and the can body 1. .

[0037]

[0038]

According to the present invention, the seaming portions S2 and S3 of the canopy 2 and the can body 1 and the bottom cover 3 and the can body 1 and the seaming portion S1 of the can body 1 are combined with the lid heating device 5 and the body heating device. for heating in the 7, in a state where the multi-joint W heated by the lid heater 5 prior stages are still enough residual heat, metal cans C in the posture change device 6 to the subsequent cylinder heating device 7 Since the multiple joints W that are hard to be heated are appropriately heated in the same manner as the other seaming parts S2 and S3, the films on the inner surfaces of the multiple joints W can be reliably fused together, so that the inner surface of the seaming part is removed. Can be completely sealed. This makes it possible to obtain a highly reliable metal can that does not cause liquid leakage or internal corrosion even during long-term use.

[Brief description of the drawings]

FIG. 1 is an overall side view of a heating device of a seaming section.

FIG. 2 is a plan view of a can feeding mechanism.

FIG. 3 is a side view of a heating unit.

FIG. 4 is a plan view of the collecting mechanism.

FIG. 5 is a side view of the roll mechanism.

FIG. 6 is a schematic perspective view of a turning mechanism.

FIG. 7 is a side view of an inlet portion of the trunk heating device.

FIG. 8 is a sectional view taken along line AA in FIG. 7;

FIG. 9 is a sectional view taken along line BB in FIG. 7;

FIG. 10 is a perspective view of a metal can.

FIG. 11 is a side view of a main part showing another embodiment of the heating coil.

FIG. 12A is a cross-sectional view of another embodiment in which the arrangement of the heating coils is changed. FIG.
It is a top view of the important section of (a).

FIG. 13 is a cross-sectional view in which the arrangement of the heating coils is changed.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 can body 2 canopy 3 bottom lid 5 lid heating device 6 attitude changing device 7 trunk heating device 10 can feeding mechanism 20 heating coil 21 operating cylinder 40 guide frame 41 feeding mechanism 42 heating coil C metal can S1 seaming section of can body S2 canopy Seam S3 Seam of bottom lid W Multiple joint

Continuation of the front page (72) Inventor Tsuruo Satake 629-17 Anaya Chatan, Kawaguchi-shi, Saitama Prefecture (56) References: JP-B-55-13824 (JP, B2) JP-B-62-55275 (JP, B2) 56-27332 (JP, B2) Jiko 62-13708 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21D 51/26 B21D 51/30 B21D 51/18

Claims (2)

(57) [Claims] 1. The seam (2) and the can body (1) of the metal can (C), and the seaming portions (S2 and S3) of the bottom lid (3) and the can body (1), are connected to the metal can (C). front lid heating device for heating while upright posture and (5), like that seaming portion of the can body (1) and (S1) laterally Wo posture
A cylinder heating apparatus subsequent heating in condition (7), the lid heating device (5) fed from a metal can (C), while attitude change to cylinder pressure <br/> thermal device (7) feeding posture change device for the (6) are arranged in a straight line, a lid heater (5) holds the metal cans (C) in the upright position
Feeding mechanism (10) for intermittent feeding at a constant pitch
Arranged above and below the can feeding stop position adjacent to the feeding direction
Heating unit for the bottom lid and heating unit for the canopy
Heating units , and both heating units are fixedly supported at fixed positions in a heating coil.
(20) and the metal can (C) toward the heating coil (20)
The cylinder heating device (7) supports the metal can (C) in the lying posture.
Guide frame (40) and metal can (C)
A feed mechanism (41) for performing a feed operation along 0) and a can body
Arranged along the trajectory of the seaming part (S1) in (1)
The attitude changing device (6) is fed from the lid heating device (5).
The metal can (C) sideways along the transport direction
Roll over mechanism (23) and roll over metal can (C) with can center axis
Around the body to adjust the heating posture of the body heating device (7).
A turning mechanism (24) for performing a displacement operation to a lying posture that matches
In this case, residual heat of a predetermined temperature remains in the multiple junction (W) where the seaming portions (S2, S3) of the lids (2, 3) and the upper and lower ends of the seaming portion (S1) of the can body (1) overlap. In a state, the metal can (C) is fed to the body heating device (7) by the posture changing device (6), and the seaming portion heating device for the metal can is provided. 2. A heating coil (20 · の ) of a lid heating device (5).
20) is composed of a high-frequency induction coil.
With the multiple junction (W) of the heating coil (20, 20)
The corresponding part (20a) is more seam than the other coil parts.
The heating device for a seaming portion of a metal can according to claim 1, wherein the heating device is provided at a position distant from the sealing portion (S2, S3) .