JP2000289740A - Method for welding synthetic resin film piece joining section in metal container and manufacture of metal container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the strength in a joining section in a welding method for synthetic resin film piece joining section of a metal container. SOLUTION: Fluororesin ribbons for welding joining sections of fluororesin film pieces 12 on the inner periphery of a metal can are fusion bonded in parallel and in multistages. In the parallel and in multistage fusion bonding, firstly one synthetic resin ribbon 94a is fusion bonded on joining lines between the fluororesin film pieces 12. Then mother synthetic resin ribbons 94b and 94c are fusion bonded in parallel on both sides of the already-fusion bonded synthetic resin ribbon, and a third synthetic resin ribbons 94d and 94e are fusion bonded in parallel on joining lines between the rigid resin ribbons 94b and 94a, and between the 94a and 94c fusion bonded in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal container such as stainless steel having a synthetic resin film such as a fluororesin on its inner surface.

[0002]

2. Description of the Related Art In a semiconductor manufacturing industry, as a metal container used for accommodating a chemical such as a photoresist, a can body is formed of stainless steel, and a fluorine resin having high chemical resistance (for example, polytetrafluoroethylene (for example, Some of them are commercially available from DuPont of the United States under the registered trademark of Teflon or the like. The fluororesin film is bonded to the inner surface of the can body with a rubber-based (acrylic) adhesive.

[0003] The diameter of the inlet of the can body is considerably smaller than the diameter of its body, and the thickness of the fluororesin film exceeds 2 mm, which is not flexible. Therefore, it is difficult to introduce a fluororesin film large enough to cover the entire inner surface of the container into a narrow container at a time to perform the bonding operation. Therefore, the fluororesin film is cut into small pieces having a size corresponding to the size of a part of the inner surface of the container, and the thus cut fluororesin film pieces are introduced into the container, and the predetermined amount in the container is set. The coating is formed on the entire surface of the inner periphery of the container by adhering to the location and repeating this process as appropriate over the entire inner periphery of the container.

If the fluororesin film piece is simply welded to the inner peripheral surface of the container, there is a possibility that leakage may occur from the gap at the joint between the fluororesin film pieces. Therefore, a ribbon (welding rod) made of fluororesin is welded to the joint by pressing under heat (hot air) to seal the joint between adjacent fluororesin film pieces.

[0005]

The ribbon made of fluororesin as a welding rod is welded to the fluororesin film by pressing under hot air. The ribbon as a welding rod also contains a fluorine resin as a main component. Therefore, the weldability of the ribbon to the fluororesin film is good. However, if only one ribbon is welded on the seam, the bonding strength is insufficient and there is a risk of leakage. That is, there is a large difference in the coefficient of thermal expansion between the stainless steel forming the can body and the fluororesin forming the coating on the inner periphery. for that reason,
When the can body is heated, the large thermal stress applied between the both concentrates intensively on the weak seam part, the seam part breaks, the solution leaks from this part, and the metal (stainless steel) part There was a risk of corrosion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to increase the strength of the joint between fluororesin film pieces around the inside of a metal can.

[0007]

According to the present invention, a synthetic resin film to be formed on the inner surface of a metal can is divided into a plurality of pieces corresponding to different portions of the inner surface of the metal can. A method of welding the synthetic resin film pieces by bonding the separated synthetic resin film pieces to corresponding portions of the inner surface of the metal can body, and welding a synthetic resin ribbon on a joining line between the divided synthetic resin film pieces. A method for welding a synthetic resin film piece joint in a metal container, wherein the welding of the synthetic resin ribbon is performed in parallel and in multiple stages along the joining line.

According to the method of welding a piece of a synthetic resin film joint, the strength of the joint can be increased by performing the welding of the synthetic resin ribbons at the joint of the synthetic resin film in parallel and in multiple stages. For this reason, it is possible to avoid the possibility of breakage of the joint and leakage of the liquid associated therewith, and further, the risk of corrosion of the metal part.

The present invention also discloses a method for manufacturing a metal container having a synthetic resin film on the inner surface of a metal can,
According to this method, a plurality of portions constituting the metal can and a synthetic resin film piece having a shape corresponding to each of the portions of the metal can are prepared, and the respective portions of the can and the corresponding synthetic resin film pieces are prepared. An adhesive is applied, and the can body portion and the synthetic resin film piece are brought into contact with each other under pressure between the adhesive applied surfaces thereof to adhere the can body portion and the synthetic resin film piece over the entire contact surface thereof, After that, welding between each part of the can body outside the can body and welding between the synthetic resin film pieces inside the can body are performed, and the welding of the synthetic resin ribbon is performed in parallel and multiple stages along the joining line. I do.

In the method for manufacturing a metal container, the same effect can be obtained that the strength of the joint can be increased by welding the synthetic resin ribbons in parallel and in multiple stages along the joint line.

In the present invention, the parallel and multi-stage welding of the synthetic resin ribbons is performed by first welding the synthetic resin ribbons along the joining lines, and then paralleling another synthetic resin ribbon on both sides of the welded synthetic resin ribbons. It can be carried out by welding and then welding another synthetic resin ribbon in parallel on the joining line between the rigid welded ribbons. By performing the parallel / multi-stage welding in this way, a maximum increase in the strength of the joint can be obtained.

In the present invention, both the synthetic resin film and the synthetic resin ribbon contain a fluororesin as a main component.

Prior to welding the synthetic resin ribbon, the joint of the synthetic resin film pieces is formed in a V-shaped cross section, and welding of a synthetic resin rod having a circular cross section to the joint ensures the required strength of the weld. Therefore, it is preferable.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows each part of a stainless steel can body 10 constituting a metal container which is separated before welding.
The stainless steel can 10 has a body 12, a bottom mirror 14, and an upper mirror 1
6 and a lid 18. The skirt 2 is attached to the bottom mirror 14.
0 is already welded. The upper mirror portion 16 has a plurality of screw holes 21 circumferentially separated from each other in a flange portion 16-1 at an upper end thereof. On the other hand, the lid 18 is a flange 16 of the upper mirror 16.
An opening 24 is provided at a position aligned with the -1 screw hole 21 and an opening 29 for mounting a nozzle.

In the embodiment of the present invention, the above-mentioned body 12, bottom mirror 14, upper mirror 16 and lid 18 of the can body 10 are each provided with a fluorocarbon film cut out of a roll into a shape suitable for each part. The pieces are glued and then the body 1 on the outer circumference
2. Stainless steel plasma welding between the bottom mirror part 14 and the top mirror part 16 and welding between the film-like fluororesin film pieces on the inner peripheral side are performed, and the lid part 18 is attached to complete the metal container. Is done. The steps up to the completion of such a metal container will be described in the following order.

The surfaces of the stainless steel parts 12, 14, 16, and 18 to which the fluororesin film pieces are adhered are shot blasted. The oxide film on the surface is removed by the shot blast treatment, and the adhesion between the stainless steel parts 12, 14, 16, and 18 and the fluororesin film piece can be improved.

Next, the step of bonding the fluororesin film pieces to the respective parts 12, 14, 16, and 18 will be described. First, the torso 1
Explaining the formation of the fluororesin film on No. 2, the fluororesin film material is, for example, polytetrafluoroethylene (registered trademark: Teflon) sold by DuPont, USA, and is wound in a roll. Condition (thickness
2.4 to 3.0 mm) supplied by the manufacturer. The roll is cut out in accordance with the shape of the required portion of the can body parts 12, 14, 16, and 18 to be covered. In FIG. 2, a fluororesin film piece cut out from a roll for covering the inner periphery of the body 12 is denoted by reference numeral 22. The width W of the fluororesin film piece 22 is slightly larger than the height H of the body 12, and the length L is made substantially equal to the inner peripheral length of the body 12.

Next, a rubber adhesive (for example, G17 of Konishi Co., Ltd.) is applied to the entire surface of the fluororesin film piece 22 by using a brush 23 or the like.
An adhesive is also applied to the inner circumference of the second. In the application of the inner periphery of the body portion 12, a band-like region where an appropriate length of adhesive is not applied is left from both ends. Then, it is left until the adhesive is completely dried. The size of the margin S is about 5 cm for the reason described later.

Next, the fluororesin film piece 22 and the body 12
When the adhesive step is explained, the fluororesin film piece 22 from which the adhesive has been dried is rolled into a cylindrical shape with the adhesive layer facing outward and inserted into the body 12. The body 12 is heated by a burner or the like, and is at a temperature at which the adhesive softens (about 80 ° C. in the case of G17 of Konishi Co., Ltd.). Then, as a preliminary operation, the fluororesin film piece 22 rounded into a cylindrical shape was pressed against the inner surface of the body 12 by a hand-held roller, and the body 12 and the fluororesin film piece 22 were lightly bonded. State. However, many bubbles remain in the adhesive layer due to spots and the like, and it is necessary to eliminate this. Next, the adhesive applied layer of the fluororesin film piece 22 is brought into close contact with the adhesive applied layer on the surface of the body 12 by a pressing device using a pair of rollers. This pressure device is composed of a pair of pressure rollers 25 and 26 as shown in FIG. The pressure roller 25 on the driving side is fixed,
Both ends are supported by fixed bearings. The rotating shaft 25-1 is connected at one end to a drive motor 27, and the rotational motion from the motor 27 is transmitted to the pressure roller 25. The roller 26 is a driven side, is rotatably supported by bearings 28 at both ends (only one end is shown), and the bearing is slidable up and down with respect to the frame.

The driven roller 26 can be lifted or rotated with respect to the driving pressure roller 25. In this state, the fluororesin film piece 22 is preliminarily provided on the inner surface between the rollers 25 and 26. The body 12 in a state of being adhered is introduced, and the driven pressure roller 26 is returned to the original position shown in FIG. As a result, the body 12 and the fluororesin film piece 22 are sandwiched between the rollers 25 and 26. At this time, the fluororesin film piece 22 is pressed against the inner surface of the body 12 by a force corresponding to the weight of the driven pressure roller 26. See also FIG. At the start of the adhesion step, as shown in FIG. 3, the position of the fluororesin film piece 22 is adjusted so that the protruding length of the fluororesin film piece 22 from both sides of the body 12 becomes a predetermined value.

As described above, the body 12 is heated to a temperature at which the adhesive is softened. In this state, when the rotation from the electric motor 27 is transmitted to the drive side pressure roller 25 (arrow F), the fluorine is released. While the resin film piece 22 is pressed against the body 12 along the entire length of the generatrix by the own weight of the driven roller 26, the body 12 and the fluororesin film piece 22 are moved in the circumferential direction as shown by the arrow G. Therefore, the still soft adhesive layer between the body portion 12 and the fluororesin film piece 22 can be leveled evenly, and even if bubbles are included in the adhesive layer due to unevenness of application of the adhesive, this is completely discharged. be able to. In other words, even if bubbles are present in the adhesive layer, the fluororesin film piece 22 is subjected to the wiping action over the entire length of the generatrix, so that the bubbles are sequentially sent to the downstream side in the rotation direction, and the rotation is repeated several times. The adhesive layer is completely leveled and can eventually be driven to a completely air-free state. During this time, the adhesive is solidified, and the fluororesin film piece 22 is adhered to the inner surface of the body 12. FIG. 11 shows a state in which the fluororesin film piece 22 is adhered to the inner surface of the body 12.
Is also shown.

In the pressing device, the driving-side pressing roller 25
The driven roller 26 has an elastic body (rubber) coated on its surface. Due to this elasticity, even if there is surface unevenness during the execution of the adhesive layer adhesion step, it can be overcome.

Next, the adhesion of the fluororesin film material to the bottom mirror portion 14 will be described. In FIG.
A circular section cut out from a roll of a fluororesin film material according to the shape of the film forming portion of the bottom mirror portion 14 is shown. The diameter of the fluororesin film piece 30 is such that when the piece 30 is applied to the inner surface of the bottom mirror 14 as shown in FIG. The diameter is selected so as to remain. A rubber-based adhesive is also applied to the inner surface of the bottom mirror 14, and the adhesive is applied to a band-like region T of an appropriate length from the upper end edge of the bottom mirror 14 covered with the fluororesin film piece 30. (See also FIG. 6). Depending on the width of the roll of the fluororesin film material, it may not be possible to cut out the fluororesin film piece 30 completely, but in this case, several fluororesin film pieces 30 are cut out as shown in FIG. ) And (d) and FIG.
It is possible to join and combine them by mating welding and ribbon welding described in 3 (e) and (f) to use them as a fluororesin film piece 30 of a complete shape.

FIG. 7 schematically shows a roller driving device for adhering a fluororesin film on a curved surface. That is, the apparatus includes a cylindrical support member 32, a rod 34 slidably received in the support member 32, and a rod 34.
And a spring 38 rotatably attached to the tip of the roller. The upper end of the support member 35 is rotatably supported by a frame (not shown) by a pin 40, and the support member 35 can swing in an upright plane. The roller 36 is arranged so that its rotation center is parallel to the swinging surface of the support member 35. Further, the support member 35 has an ear 42, and the ear 4
A manual or power-type lever (not shown) is connected to 2, and by operating this lever, the position and speed of the support member 35 in the close contact process can be controlled.

Next, the roller rolling process by the apparatus shown in FIG. 7 will be described with reference to FIG. 6 as well. After the adhesive is dried, the fluororesin film piece 30 is placed on the inner surface of the bottom mirror portion 14 with the adhesive applied surface facing downward. Apply to The bottom mirror 14 is heated by a burner or the like to a temperature of about 80 ° C. at which the adhesive softens. Then, manual preparation is performed as preparation work. That is, the fluororesin film piece 30 is pressed against the inner surface of the bottom mirror part 14 by a hand-held roller so that the fluororesin film piece 30 follows the concave shape of the inner periphery of the bottom mirror part 14. After this preparatory work, a close contacting step is performed by the apparatus shown in FIG. At the start of the close contact process, the roller is moved by a two-dot chain line 36 'by operating a control lever (not shown).
As shown by, it is located on the upright center line 44 of the concave surface of the bottom mirror portion 14. Then, the roller 36 presses the fluororesin film piece 30 against the inner surface of the bottom mirror section 14 under the elastic force of the spring 38. Then, by rotating a table (not shown) on which the bottom mirror section 14 is placed, the bottom mirror section 1 is rotated.
4 is rotated about the center line 44 as indicated by the arrow F (see also FIG. 6). As described above, while the bottom mirror portion 14 is being rotated, a pulling force is applied to the ear portion 42 as indicated by an arrow G by operating the lever, and as a result, the support member 32 whose upper end is pivotally supported by the pin 40 becomes an upright surface. (The surface including the paper surface) is gradually moved radially outward as indicated by an arrow H. While pressing the fluororesin film piece 30 against the inner surface of the bottom mirror section with a constant force by the roller 36 receiving the elastic force, the bottom mirror section 14 is rotated around the upright center line 44 and the roller 36 is rotated.
Is gradually moved outward from the center, the adhesive between the contact surfaces between the bottom mirror portion 14 and the fluororesin film piece 30 is made uniform, and the air bubbles contained therein are removed by the roller 36. As it moves, it is gradually spiraled outward from the radius, and finally discharged to the outside. for that reason,
In the adhesive layer between the contact surface between the bottom mirror portion 14 and the fluororesin film piece 30, it can be driven into a state in which bubbles are completely eliminated. During this time, the adhesive is solidified, and the fluororesin film piece 30 is adhered to the bottom mirror surface.

Instead of the spring 38 described above, an air cylinder or a hydraulic cylinder may be used to press the roller 36 under fluid pressure such as air pressure or hydraulic pressure.

Next, the formation of a fluororesin film on the upper mirror 16 will be described with reference to FIGS. A rubber-based adhesive is applied to the inner surface of the upper mirror 16 as in the case of the bottom mirror 14 described with reference to FIG. In FIG. 8A, the inner and upper surfaces of the flange 16-1 are coated with an adhesive.
Drying is performed. On the other hand, a circular piece 46 having a hole at the center is cut out from the fluororesin film pulled out from the roll. The fluororesin film piece 46 has an opening 48 circumferentially spaced at each location where the screw hole 21 of the flange portion 16-1 is formed. Then, an adhesive is applied to the lower surface of the fluororesin film piece 46 and dried.

At the next stage, as shown in FIG. 8 (b), the fluorine resin film piece 46 is applied to the flange portion 16-1 on the adhesive applied surface, and the bolt 50 is moved to the opening 48 of the fluorine resin film piece 46. Through the screw hole 21 of the flange portion 16-1. A center insert 52 having an outer diameter smaller than the center opening of the flange portion 16-1 by the thickness of the film (heated to a predetermined temperature of about 80 ° C. for softening the adhesive) is interposed from above through the fluororesin film piece 46. Into the center opening of the flange 16-1. (C) of FIG.
Is shown, and the fluororesin film piece is deformed so as to extend along the inner periphery of the center opening of the flange portion 16-1. Next, a flanged tubular outer insert 54 having an inner diameter that fits snugly into the center insert 52.
(Also heated to a predetermined temperature of about 80 ° C. for softening the adhesive) is inserted into the center insert 52 from below. The flange portion 54-1 of the outer insert 54 crushes the fluororesin film piece 46, and shows a state in which the crushed portion of the section 46 is in close contact with the inner periphery of the upper mirror 16 as shown in FIG. . During that time, the adhesive solidifies, and the fluororesin film is completely bonded. afterwards,
As shown in (e), the inserts 52 and 54 are removed, and the bolt 50 is also removed.

As described above, the flange portion 16-1 of the upper mirror portion 16
After the fluororesin film piece 46 is bonded to the bottom mirror portion 12 described with reference to FIGS.
This is carried out in the same manner as the adhesion of the fluororesin film piece 30 to the surface.
That is, the size of the fluororesin film piece 56 is such that a margin of about 5 cm remains from the widened edge when it is adjusted to the concave surface of the upper mirror portion 16. After drying the adhesive applied to the concave surface of the upper mirror portion 16 and one surface of the fluororesin film piece 56, while heating the upper mirror portion 16 to about 80 ° C,
The adhesive-coated surface of the fluororesin film piece 56 is aligned with the concave surface of the upper mirror 16 to which the adhesive has been applied, and the fluororesin film piece 56 follows the concave shape of the inner periphery of the upper mirror 16 by a manual roller. To Then, as shown in FIG. 9F, the upper mirror section 16 is placed on the turntable 58 with the flange section 16-1 down, and while rotating the turntable 58 about its upright center line 44, Under the force, the fluororesin film piece 56 is pressed against the inner surface of the upper mirror section 16 by the roller 36 and the roller 36 is moved radially outward from the center side.
Therefore, the adhesive between the contact surfaces of the upper mirror portion 16 and the fluororesin film piece 56 is made uniform, and the bubbles contained therein are gradually sent to the outside of the radius as the roller 36 moves. Eventually it is discharged outside. Therefore, air bubbles can be driven into a state in which air bubbles are completely eliminated in the adhesive layer between the contact surfaces between the upper mirror section 16 and the fluororesin film piece 56. During this time, the adhesive progresses,
The fluororesin film piece 56 is in a state of being adhered to the surface of the upper mirror.

Thereafter, abutting welding and ribbon welding of the abutting surfaces of the fluororesin film pieces 46 covering the flange portion 16-1 and the fluororesin film pieces 56 covering the inner surface of the upper mirror portion are performed. Is the same as the joint welding and the ribbon welding at the abutting portion between the trunk portion and the bottom mirror portion and between the trunk portion and the upper mirror portion, which will be described later.

FIGS. 10A to 10D illustrate the bonding of the fluororesin film piece to the lower surface of the lid 18 and the nozzle welding. (B) shows the adhesion of the fluororesin film piece 57 to the lower surface of the lid. Next, as shown in (c), the nozzle hole 29 is expanded as shown by 29 ', and the expanded nozzle hole 29 is filled with the fluororesin nozzle 61 as shown in (d).
Is inserted. A fluororesin welding rod is applied to an outer peripheral portion of the nozzle 61 protruding from the fluororesin film piece 57, and hot air is blown onto the nozzle 61 so as to be welded along the entire circumference as indicated by 63. After the container is completed (see FIG. 19 for the completed state), external connection parts such as valves are attached to the nozzle 61.

Next, the welding between the can parts 12, 14 and 16 after the formation of the fluororesin film on the inner surface as described above will be described. In this invention, stainless steel welding is first performed between the canned portions on the outer periphery between the joints, and then the fluororesin ribbon welding between the fluororesin film pieces is performed on the inner periphery. FIG. 11 shows a state in which the upper mirror 16 and the lid 18 are prepared with the upper mirror 16 and the lid 18 turned sideways for welding the body 12 and the bottom mirror 14. Numeral 60 denotes an abutting portion between the body portion 12 and the bottom mirror portion 14, along which the stainless steel plasma welding is performed. As described with reference to FIG. 2, the body 12 has a region S (see FIG. 2) where no adhesive is applied at both ends, and the bottom mirror portion 14 has a region T where the adhesive is not applied at its edge. (FIG. 5
See). The lengths of the regions S and T are the lengths of the region of the body portion 12 and the bottom mirror portion 14 which can be increased to a temperature at which the fluororesin film may be thermally degraded at a high temperature during the plasma welding of the stainless steel on the outer periphery. A centimeter is sufficient. Fluororesin film piece 22 covering body 12
Is longer than the length of the body 12, so that the end 22 ′ of the non-bonded fluororesin film piece is connected to the body 12 and the bottom mirror 1.
4 and slightly overlap the edge of the fluororesin film piece 30 covering the bottom mirror portion 14 via the abutting portion 4. This state is shown enlarged in FIG. FIG. 12B shows a state in which a baffle plate 62 is installed for welding the abutting portion 60 between the body portion 12 and the bottom mirror portion 14 made of stainless steel. This baffle plate 62
This is for protecting a portion of the fluororesin film (melting point is at most 300 ° C.) close to a high temperature (as high as 2000 ° C. in a flame portion) generated at the time of plasma welding between 2 and the bottom mirror portion 14. That is, the end face of the fluororesin film piece 30 formed on the inner surface of the bottom mirror portion 14 becomes the abutting welding surface in the fluororesin ribbon welding performed later. The fluororesin film piece can be shielded and protected from the influence of heat by such an offset arrangement and the use of the baffle plate 62 by being arranged offset from the butting welding surface 60 exhibiting a high temperature. The baffle plate 62 is made of SUS steel and has an annular shape arranged along the abutment portion 60. The baffle plate 62 has a U-shaped cross section straddling the abutment surface 60, and sheets 64, 66 formed of a noncombustible material (for example, glass wool) on the inner and outer circumferences of the U-shaped cross section. Are formed.

FIG. 15 schematically shows a stainless steel plasma welding method between the body portion 12 and the bottom mirror portion 14. The body portion 12 and the bottom mirror portion 14 are mounted on a supporting device 70 having rollers in a lateral direction. The plasma welding head 72 is mounted on the support 7
3 up and down (arrow a) and horizontal movement (arrow b)
Attached to the tip of a possible arm 74. The arm 74 is urged downward by a known air pressurizing means, and the rest roller 76 is in contact with the upper surface of the body 12. The CCD camera 78 is provided for monitoring the welding condition at the welding portion, and the CCD camera 78 is connected to a computer 80 having a monitor. A control panel 82 operated by a driver can finely move the welding head 72 right and left via the computer 80 to control the welding beam so as to accurately hit the portion to be welded.

At the time of welding, the body 12 and the bottom mirror 14 are rotated by the rollers of the support device 70 (arrow J), and the body 12 and the bottom mirror 14 are brought into contact with the abutment 60 by the plasma flame from the welding head 72. Is welded along.
During this time, the driver monitors the welding condition at the welded portion photographed by the CCD camera 78 on the monitor of the computer 80, and if necessary, operates the control panel 82 to obtain the welding beam of the welding head 72 in order to obtain the optimal welding condition. Is performed.

In FIG. 12C, after stainless steel welding is completed, the baffle plate 62 is removed, and the body 12 and the bottom mirror 1 are removed.
4 is schematically represented by the numeral 90. Thereafter, an adhesive is applied to the regions S and T on the inner surfaces of the body portion 12 and the bottom mirror portion 14, and one end 2 of the fluororesin film covering the body portion 12.
An adhesive is also applied to and bonded to the inner surface of 2 '. Then, mating welding and ribbon welding of the fluororesin film piece 22 covering the body 12 and the fluororesin film piece 30 covering the bottom mirror part 14 are performed. Hereinafter, this welding step will be described. First, as shown in FIG.
Fluororesin film piece 22 covering body 12 and bottom mirror 14
The abutting surface with the fluororesin film piece 30 for covering is cut into a V-shape. The fluororesin welding rod 92 having a circular cross section is applied to the V-shaped groove obtained in this manner, and joint welding by hot air from the hot air of the plasma welding head is performed. (D) 93 indicates a portion which has been subjected to joint welding, and joint welding is performed by a welding head 97 shown in FIG. After the joint welding, ribbon welding is performed. In the present invention, ribbon welding is performed in parallel and two times as shown in (d) of FIG. 12 and (e) and (f) of FIG.
Done in steps. In ribbon welding, the welding rod made of fluororesin is in the form of a ribbon with a rectangular cross section, and the welding rod (a piece of the fluororesin film on the inner surface of the can) is moved (rotating the can body) while moving the welding rod with hot air. It is welded to the joint by supplying it under pressure. Figure 17 shows the head for ribbon welding.
(A).

The parallel / multi-stage ribbon welding will be described. As shown in FIG. 12D, first, the ribbon is supplied under hot air and pressure along the joint welding portion 93, and the ribbon is welded. 94a shows the portion of the molten metal after the first ribbon welding. Next, as shown in FIG. 13E, ribbon welding is sequentially performed on both sides of the first ribbon welding portion 94a as shown by 94b and 94c. As a result, three ribbon welding portions 94b, 94a, 94c are juxtaposed in parallel and closely on the joining portion of the fluororesin film piece 22.
Is formed. Next, these ribbon welds 94b, 94a, 9
Perform second-stage ribbon welding on 4c in parallel. That is, the ribbon welding is performed in parallel and closely on the joining line between the ribbon welding portions 94b, 94a, 94c as shown by 94d, 94e. The finally obtained ribbon weld is shown at 94.

Parallel and multi-stage ribbon welding as in the present invention
The joint strength between fluororesin film pieces
There is an effect that can be dramatically increased. Below,
The test results for strength are shown. Fluororesin film (mother
Material) is marketed under the trade name Polyflon (registered trademark).
250 m long made of polytetrafluoroethylene
m, width W₁= 50 mm, thickness T₁= 3.0 mm
Neoflon (registered trademark) as a fluororesin ribbon
Trademark W)₂= 14 mm, thickness T ₂=
The thing of 2.4 mm was used. (A), (b), and (c) in FIG.
Three types of samples were prepared. sample
In (a), one piece is placed on the joint welding portion 93 between the base materials.
Only one ribbon 94a is welded. The sample (b)
In addition to ribbon 94a, ribbons 94b and 94c are welded on both sides.
Indicates a column structure. Sample (c) is ribbon 94b, 94a
Lined up to cover the joint between
Shows two-stage parallel structure with ribbons 94d and 94e welded to rows
You. These samples (a) to (c) are tensile testers
Was subjected to a breaking load test. Table I below shows the
The test results are shown.Table I Sample load (kgf) Cutting point Specimen (a) 345 Welded specimen Specimen (b) 335 Welded specimen (c) 362 Base material As is clear from the results of Table I above, in the practice of the present invention,
In the case of parallel / multi-stage welding of a test specimen (c), the cutting load
Weight is the highest and more importantly the cut is
It was caused by the base metal part. This is
In the case of the parallel / multi-stage welding, which is the invention, there is no defect in the welding.
And that no liquid leakage through the weld can occur.
I taste. For specimens (a) and (b) that are not in a parallel / multistage structure
The break is caused at the weld, in which case the weld is broken.
This indicates that liquid leakage due to disconnection may occur.

FIG. 16 schematically shows a method for joint welding and ribbon welding. That is, the welding head 96 for ribbon welding or the welding head for mating (FIG. 17)
(B) 97) is attached to the tip of the arm 98. The arm 98 can move up and down (arrow c) and move left and right (arrow d) with respect to the support table 100. On the other hand, the body portion 12 and the bottom mirror portion (skirt 20) to which the fluororesin film pieces 22, 30 are to be welded are placed on the rollers 70A, 70B of the support device 70, and are mounted thereon by the rotation of the rollers 70A, 70B. The rotated body 12 and bottom mirror 14 can be rotated.

FIG. 17A schematically shows the configuration of a welding head 96 for ribbon welding. That is, the welding head 96 is heated to a temperature (for example, 400
C.) and a guide portion 96B for a ribbon-shaped welding rod 102 drawn out from a roll (not shown). At the start of welding, hot air from nozzle 96A is applied to welding rod 102 while applying the tip of welding rod 102 to the welded portion (line L mating welding portion is virtually shown in FIG. 17A). The welding rod 102 is melted by spraying from the back. Roller 70A,
By the rotation of 70B, the welding rod 102 is automatically pulled out, and at the same time, the drawn-out portion of the welding rod 102 is melted by hot air from the nozzle 96A, and is superimposed on the welded joint 93 to form the welded part 94a. Become melt.

In the present invention, since the ribbon welding is performed in parallel and in multiple stages, the container and the head 96 are formed after the welded portion 94a is formed.
The ribbon is welded in parallel on both sides of the welded portion 94a as shown by 94b and 94c by slightly shifting (the state after the execution of the welding step is the same as that shown in FIG. 14B). To 2
The welding of the steps is performed as shown at 94d and 94e (the state after the execution of the welding step is as shown in FIG. 14C). FIG. 16 shows the parallel / multi-stage welded portions 94 after the ribbon welding is completed.

FIG. 17 (B) shows a welding head 97 for joint welding performed prior to ribbon welding. The welding head 97 is attached to the tip of the arm 98 in FIG. Head 9
7 includes a hot air nozzle 97A and a pipe-shaped guide portion 97B for guiding the round-shaped welding rod 92. During welding,
The guide portion 97B performs intermittent vertical movement using air pressure or the like, and when the guide portion 97B descends, the welding rod 92 guided by the guide portion 97B forms a V-shaped groove between the fluororesin film pieces 30 and 32 (FIG. 12).
(See (c) and (d)). Then, the guide 9
7B is raised to advance the welded portion (roller 70 in FIG. 16).
While the can body is being rotated by A and 70B), hot air is blown behind the welding rod 92 from the nozzle 97A. Therefore, welding rod 9
Numeral 2 becomes a melt 93 (FIG. 12 (d)) and melts into the V-shaped groove. After a certain distance welding, the guide part 97B is lowered again,
The welding rod is embedded in the V-shaped mating groove, and the same operation is repeated for the entire circumference thereafter.

Next, plasma welding of stainless steel on the outer periphery and fluororesin ribbon welding on the inner periphery of the upper mirror portion 16 are performed. Although not described in FIG. 9 (f),
After the fluororesin film piece 56 is adhered to the inner periphery of the upper mirror portion 16, the abutting portion of the fluororesin film piece 46 covering the flange portion 16-1 is cut out in a V-shape, and the body portion 12 and the bottom mirror are cut off. Part 14
With respect to the joining, the mating welding is performed by the fluororesin welding rod in the same manner as described with reference to FIGS.
Thereafter, the parallel / multi-stage ribbon welding described in (e) to (f) of FIG. 13 is performed. FIG. 18 shows a state in which the upper mirror 16 obtained in this manner is positioned to be welded to the body 12. A parallel / multi-stage ribbon weld is shown at 97. In this state, the abutting surface 10 between the body 12 and the upper mirror 16 on the outer periphery is used for joining between the body 12 and the bottom mirror 14 in the same manner as described with reference to FIG.
The stainless steel plasma welding of No. 4 is performed first. That is,
A baffle plate similar to the baffle plate 62 shown in FIG. 12B is provided on the inner circumference to prevent the influence of high temperature in plasma welding. The welded portion after the plasma welding is performed is indicated by 106. After the plasma welding between the body 12 and the upper mirror 16, joint welding is performed on the abutting surface between the fluororesin film piece 22 on the inner circumference of the body 12 and the fluororesin film piece 56 on the inner circumference of the upper mirror 16. And parallel
Multi-stage ribbon welding is performed in the same manner as the method described in FIGS. 12 (C) and (D) and FIGS. 13 (E) and (F). In FIG. 19, a parallel / multi-stage welded portion after the ribbon welding is performed is indicated by 108.

Finally, the metal container is completed by fixing the lid 18 to the upper mirror 16 with bolts 110 as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a sectional view showing each part of a can body in a separated state.

FIG. 2 is a schematic perspective view showing a state in which an adhesive is applied to a fluororesin film piece covering a body and its inner periphery.

FIG. 3 is a view showing a roller device for tightly contacting the surface of the body with the fluororesin film piece at the body.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a schematic perspective view showing a state in which an adhesive is applied to a fluororesin film piece covering the bottom mirror portion and the inner surface thereof.

FIG. 6 is a view similar to FIG. 5, but showing a state in which a fluororesin film piece is laid on the concave surface of the bottom mirror by a roller.

FIG. 7 is a sectional view showing a roller-type pressing mechanism used in FIG. 6;

FIG. 8 is a view showing stages (a) to (c) of a bonding step of a fluororesin film piece in the upper mirror portion.

FIG. 9 is a view showing stages (d) to (f) of a bonding step of a fluororesin film piece in the upper mirror portion.

FIG. 10 is a view showing stages (a) to (d) of a bonding process of a fluororesin film piece on a lid portion.

FIG. 11 is a diagram showing a joint state between the body and the bottom mirror before welding.

12 (a) to 12 (d) show how stainless plasma welding of the outer periphery and subsequent hot-air fluororesin welding of the inner periphery are performed at the abutting portion between the trunk and the bottom mirror. Is a diagram for explaining step by step. FIG.

13 is a step subsequent to (a) to (d) of FIG. 12 in FIG. 13;
It is a figure which shows (e) and (f).

FIGS. 14 (a) to (c) show samples for a strength test of a ribbon welded part, respectively.

FIG. 15 is a schematic perspective view illustrating an automatic stainless steel plasma welding method on the outer periphery of the body and the bottom mirror.

FIG. 16 is a schematic cross-sectional view for explaining an automatic fluororesin welding method using hot air on the inner periphery of a trunk portion and a bottom mirror portion.

17 (A) shows a schematic perspective view of a welding head for welding a fluororesin ribbon in (A), and FIG. 17 (B) shows a schematic perspective view of a welding head for welding and joining of a fluororesin in (B).

FIG. 18 is a cross-sectional view showing a state in which the upper mirror is joined to the upper end of the body to weld the upper mirror to the body to which the bottom mirror has been welded.

FIG. 19 is a cross-sectional view of a completed metal container in which the inner periphery of a stainless steel can is completely coated with a fluororesin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Stainless steel can 12 ... Trunk part 14 ... Bottom mirror part 16 ... Top mirror part 18 ... Lid part 20 ... Skirt part 22 ... Fluororesin film piece for coating the inner surface of a trunk part 25 ... Driving pressure roller 26 ... Pressure roller 28 ... Sliding bearing 30 ... Fluororesin film piece for coating the inner surface of bottom mirror 34 ... Rotable rod 36 ... Roller for adhesive leveling 38 ... Spring 46 ... Fluoro resin film piece for coating the inner surface of upper mirror part 52 ... Center insert 54 ... Outer insert 57 ... Sheet of fluororesin film for covering the inner surface of the lid 58 ... Rotating table 61 ... Nozzle 62 ... Baffle plate 62,64 ... Sheet made of noncombustible material 70 ... Support device 72 ... Plasma welding head 78 ... Welding state Monitoring CCD camera 80 Computer 82 Control panel 92 Welding rod 96 Fluoro resin hot air welding head

Claims (5)

[Claims] 1. A synthetic resin film to be formed on the inner surface of a metal can body is divided into a plurality of pieces corresponding to different portions of the inner surface of the metal can body. In the method of welding between synthetic resin film pieces by adhering to the corresponding portion of the inner surface of the above and welding the synthetic resin ribbon on the joining line between the divided synthetic resin film pieces, the welding of the synthetic resin A method of welding a joint portion of a synthetic resin film piece in a metal container, wherein the welding is performed in parallel and in multiple stages along the line. 2. A method for manufacturing a metal container having a synthetic resin film on an inner surface of a metal can body, the synthetic resin having a shape corresponding to a plurality of portions constituting the metal can body and the respective portions of the metal can body. Prepare a coating piece, apply an adhesive to each part of the can body and the corresponding synthetic resin film piece, and bring the can body part and the synthetic resin film piece into contact with each other with the adhesive applied surfaces under pressure. The can body portion and the synthetic resin film piece are adhered to each other over the entire surface of the contact surface, and then welding between each part of the can body outside the can body and welding between the synthetic resin film pieces inside the can body are performed. For welding between the coating pieces, use a synthetic resin ribbon,
A method for manufacturing a metal container, which is performed by welding in parallel and in multiple stages along a joining line. 3. The method according to claim 1, wherein
For the parallel / multi-stage welding of the synthetic resin ribbon, first, the synthetic resin ribbon is welded along the joining line, and then another synthetic resin ribbon is welded in parallel on both sides of the welded synthetic resin ribbon. And welding another synthetic resin ribbon in parallel on the joining line between the parallel-welded rigid resin ribbons. 4. The method according to claim 1, wherein each of the synthetic resin film and the synthetic resin ribbon contains a fluororesin as a main component. 5. The method according to claim 1, wherein prior to welding of the synthetic resin ribbon, a joining portion of the synthetic resin film piece is formed in a V-shaped cross section, and a cross section is formed at the joining portion. A method comprising welding a circular synthetic resin rod.