JPH11320175A - Method and device for manufacturing cylindrical body for steel drum can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothen a step part of a drum can at high efficiency resulting in improvement of quality by narrow-pressing/pressurizing a side edge part to be welded of a cylindrical body by means of a pair of narrow-pressing rolls at a given temperature immediately after the welding. SOLUTION: Side edges of a cylindrical body 1, obtained by forming a steel sheet into a cylindrical shape and overlapping its side edges, are welded by electrode rolls 2a, 2b. The side edge portion immediately after the welding is narrow-pressed and pressurized at 400 deg.C or above by means of a pair of narrow-pressing rolls 4a, 4b. One roll 4a is mounted to a supporting arm 3, and the other roll 4b is rotatably mounted to a frame 100 side where an electrode roll 2b is installed, so as to drive both of them by a motor 7. A load transmitting roll 5b is mounted on the opposite side to the roll 4a of the supporting arm 3, so that a pressing force of the roll 5b can be applied to an outside load transmitting roll 5a via the cylindrical body 1. The roll 5a is held by a member 300. The member 300 is integrated with the bottom frame 100, so as to obtain an enough narrow-pressing force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a steel drum, and more particularly to a post-treatment after welding a side edge portion of a cylindrical portion thereof.

[0002]

2. Description of the Related Art A steel drum can is formed by rolling a thin steel plate into a cylindrical shape, and welding a side edge thereof to form a cylindrical body.
Next, flange processing is performed on both ends of the cylindrical body, and furthermore, a reinforcing ring is formed on the cylindrical body, and oil, dirt, etc. attached to the surface are cleaned, and then the cylindrical body is tightened by winding or the like. It is manufactured by attaching a base plate and, if necessary, a top plate, and then painting.

[0003] However, the bead generated when welding the side edge portion of the cylindrical body has a convex shape, and at the time of welding, a step is generated by superimposing thin steel plates in the circumferential direction, so that welding is performed. However, there are problems that the corner portions of the side edges are not sufficiently coated, and that the adhesion of the coating film is reduced. In addition, there is also a problem that the top plate and the base plate are incompletely tightened due to the presence of the step portion.

[0004] Therefore, after welding, only the both ends of the cylindrical body are cold-forged at both ends to eliminate a step from the bead and smoothen in the circumferential direction. Also, in JP-A-5-96336,
Using a device different from the device that makes the cylindrical body by welding the side edges,
The smoothed bead and step are realized by a method in which the welded cylindrical body is placed on a support table, and a rotating roller is advanced inside the cylindrical body to cold-crush the entire length of the welded portion at the side edge.

[0005]

However, in the conventional local smoothing by cold forging, since only the both ends of the cylindrical body can be processed, the above-mentioned beads and steps remain in portions other than both ends. Therefore, there is a problem that sufficient corrosion resistance cannot be obtained after painting over the entire length.

Further, in the method disclosed in Japanese Patent Application Laid-Open No. 5-96336, although corrosion resistance after coating can be ensured, the weld bead after cold crushing is work-hardened, and the bead becomes brittle, resulting in an annular zone. There are problems such as cracking during processing and flange processing. An object of the present invention is to provide a method and an apparatus for manufacturing a cylindrical body for a steel drum, which can solve the above-mentioned problems, achieve a highly efficient smoothing of the stepped portion, and improve the quality of the steel drum. And

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for manufacturing a cylindrical body for a steel drum can, wherein a cylindrical body is formed by welding and forming a cylindrical body while the side edges of a thin steel sheet formed into a cylindrical shape are overlapped and advanced. The above object has been solved by a method for manufacturing a cylindrical body for a steel drum can, characterized in that the welded side edge of the body is reduced by pressing with a pair of pressing rolls immediately after welding at a temperature of 400 ° C. or more. is there.

Further, in the above invention, a load transmitting roll is provided on a support arm of the pair of pressing rolls which holds the pressing roll on the inner surface side of the cylinder, and forms a pair with the load transmitting roll. It has been found that it is preferable to provide a load transmitting roll on an outer member via a side wall of the cylindrical body. In addition, the inventor has found that it is preferable to provide a set of guide rolls for guiding the cylindrical body to the support arm, and to advance the cylindrical body along the guide rolls.

[0009] In the apparatus for manufacturing a cylindrical body for a steel drum can, which forms a cylindrical body by welding the side edges of the thin steel sheet formed into a cylindrical shape while superimposing and proceeding, a pair of squeezing pressures for squeezing the welded portion is provided. The problem was solved by providing the roll immediately after the electrode roll for welding. In the above manufacturing apparatus, a load transmitting roll is provided on a support arm that holds the pressing roll on the inner surface side of the cylinder, of the pair of pressing rolls, and the load transmitting roll forms a pair with the load transmitting roll. It has been found that it is preferable to provide the outer member through the side wall of the cylindrical body.

It has also been found that it is preferable to provide a guide roll for guiding the cylindrical body to the support arm.

[0011]

FIG. 1 shows an example of the apparatus of the present invention for producing a cylindrical body for a steel drum. (A) is a side view, (b) is a front view. In the drawing, reference numeral 1 denotes a cylindrical body formed by forming a thin steel plate into a cylindrical shape and overlapping the side edges.
The cylindrical body 1 is advanced in the direction of the arrow shown in the figure (leftward in the figure) by a moving device (not shown), for example, a moving device that hooks the cylindrical body to a belt, and is welded by the electrode rolls 2a and 2b. .

Reference numeral 3 denotes a support arm which overhangs from the gantry 200 and has an electrode roll 2a attached thereto. The support arm has one of the pressing rolls 4a which is a feature of the present invention.
Is rotatably mounted. In the present embodiment, the pressing roll 4a is not provided with a driving device, but may be driven to rotate by a motor. The other pressing roll 4b, which is in contact with the outside of the cylindrical body, is rotatably attached to the gantry 100 on the pass line where the electrode roll 2b is provided, and is driven by the motor 7. Further, the pressing force for pressing the side edge acting between the pressing rolls 4a and 4b is applied around the fulcrum J of the guide 6b.
The pressure is adjusted by changing the pressure of a pressurizing device 400, for example, a hydraulic cylinder, which moves 6b up and down.

The clamping roll 4b is rotatably supported not by the guide 6b but by a member provided separately from the guide 6b, and the member is movably supported up and down. May be adjusted. Note that 6
a and 6b also have a role of a guide for stabilizing the progress of the cylindrical body. This pressing force may be given only by the clamping force generated between the gantry 100 and the support arm 3, but it may be difficult to obtain a sufficient clamping force due to the elasticity of the arm.

For this purpose, a load transmitting roll 5b is attached to the support arm 3 on the side opposite to the pressing roll 4a, and the pressing force of the load transmitting roll 5b is applied to the external load transmitting roll 5a via the cylindrical body 1. The load transmitting roll 5a is a member 30
0, and in the figure, the member 300 is
, So that a sufficient clamping pressure can be obtained.

The load transmitting roll 5a is driven by the motor 7 like the pinching roll 4b, and contributes to the advance of the cylindrical body. The load transmitting rolls 5a and 5b preferably have a large roll diameter and a large contact area so as to prevent a portion in contact with the cylindrical body from being processed by these rolls. Further, it is preferable that the barrel length of each of the load transfer rolls 5a and 5b is long, and that the load transfer roll 5a is provided with a concave crown and the load transfer roll 5b is provided with a convex crown according to the shape of the cylindrical body.

Further, the pressing roll 4a and the load transmitting roll 5b
May be brought into direct contact with each other to roll. here,
The members 300 are preferably fixed to the gantry 100, but may be fixed to the floor independently. Similarly, the gantry 100 and the gantry 200 may be integrally connected, or may be independently fixed to the floor. Also, they may be integrated.

As shown in FIG. 2, in order to prevent deviation of the advance of the cylindrical body and to enable more stable advance, the cylindrical body is provided on both side surfaces of the arm 3 in a direction perpendicular to the clamping direction. The guide roll 8 which comes into contact with the inner surface may be rotatably provided. As described above, immediately after welding, the side edge of the cylindrical body is smoothed to eliminate the step with the bead.
Overhangs occur at both ends of the. This overhang is
Cut in the next step. After that, the above-described flange processing, ring forming processing, and at least the main plate winding processing are performed, followed by painting, and a steel drum can is manufactured.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A steel drum can obtained by welding a side edge portion of a cylindrical body and then performing hot or warm working at 400 to 700 ° C. with a pressing roll at a side edge portion is an example of the present invention. Was used as a comparative example. Further, a steel drum can cold-worked by a rotating roller with the side edge of the cylindrical body placed on a support table is referred to as Conventional Example 1, and a drum can manufactured without processing the side edge after welding is referred to as Conventional Example 2. Were compared. Tables 1 and 2 show the results.

[0019]

[Table 1]

[0020]

[Table 2]

Here, in Table 1, the corrosion resistance after coating is determined by conducting a 5% salt spray test for 48 hours and determining the occurrence of rust at the weld step. When there is a lot of rust, it is x, and when it is little, it is x. The Vickers hardness is used as an evaluation criterion for the hardness of the welded portion, and x (hard) is 180 or more and ○ is less than 180. As shown in Tables 1 and 2, the steel drum according to the present invention has lower weld hardness than Conventional Example 1 and Comparative Example, and has better corrosion resistance than Conventional Example 2.

In the present invention, the welded portion of the cylindrical body is hot or warm-worked with a pressure roll at a surface temperature of 400 ° C. to 700 ° C. immediately after welding. As described above, since the workpiece is processed in a hot or warm state, the structure is refined,
The ductility and toughness are improved, and the hardening after processing can be reduced as compared with the case of processing in a cold state. Table 2
As shown in the above, in the comparative example and the conventional examples 1 and 2, welding cracks are generated during the processing of the flange and the annular zone. However, according to the present invention, it is possible to eliminate the occurrence of welding cracks during the processing of the flange and the annular zone. Was. In Conventional Example 2, since the side edge is not processed, the corrosion resistance after painting is inferior.

Further, the cylindrical body to which the present invention is applied has no steps in the circumferential direction, and complete smoothing is realized. Furthermore, the fine wavy surface of the bead corresponding to the welding nugget became flat, the corrosion resistance after painting was remarkably improved, and the problem of poor winding was solved.

[0024]

According to the present invention, the welding step of the cylindrical body is
Since the nip pressure is reduced by a pair of nip rolls at a temperature of not less than ° C., the bead and the step on the side edge of the cylindrical body can be easily smoothed, and embrittlement after the smoothing can be prevented. As a result, the rate of occurrence of welding cracks and poor tightening is significantly reduced,
Corrosion resistance after painting was also greatly improved.

[Brief description of the drawings]

1 (a) is a side view and FIG. 1 (b) is a front view showing a cylindrical body manufacturing apparatus of the present invention.

FIG. 2 shows a cylindrical body manufacturing apparatus according to another embodiment of the present invention.
(A) is a side view, (b) is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical body (cylindrical part of a drum can) 2a, 2b Electrode roll 3 Support arm 4a, 4b Nipping roll 5a, 5b Load transfer roll 6a, 6b Guide 7 Motor 8 Guide roll 100, 200 Mounting base 300

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Kato Itami City Aramaki Kagida 10 Kawatetsu Container Co., Ltd. Technical Department (72) Inventor Tsutomu Hanato 1-155 Mizushima Nishidori, Kurashiki City Kawatetsu Container Co., Ltd. Mizushima Inside plant (72) Inventor Hiroyuki Miura 1-1955 Mizushima Nishidori, Kurashiki-shi Inside Kawasaki Iron Container Co., Ltd. Mizushima Plant

Claims (6)

[Claims] 1. A method for manufacturing a cylindrical body for a steel drum can, wherein a side edge of a thin steel sheet formed into a cylindrical shape is overlapped and advanced while welding to form a cylindrical body, wherein the welded side edge of the cylindrical body is welded. Immediately after welding by a pair of clamping rolls at a temperature of 400 ° C. or more. 2. A load transmitting roll is provided on a support arm of the pair of pressing rolls which holds the pressing roll on the inner surface side of the cylinder, and the load transmitting roll and the load transmitting roll are paired with each other. The method for producing a cylindrical body for a steel drum according to claim 1, wherein the cylindrical body is provided on an outer member via a side wall of the cylindrical body. 3. A guide for guiding a cylindrical body to the support arm.
3. The method for producing a cylindrical body for a steel drum according to claim 1, wherein a set of guide rolls is provided, and the cylindrical body is advanced along the guide rolls. 4. An apparatus for manufacturing a cylindrical body for a steel drum can, which forms a cylindrical body by welding the side edges of a thin steel sheet formed into a cylindrical shape while superimposing the steel sheets on each other, and pressing the welded portion.
An apparatus for manufacturing a cylindrical body for a steel drum can, wherein a pair of pinching rolls is provided immediately after an electrode roll for welding. 5. A load transmitting roll is provided on a support arm of the pair of pressing rolls which holds the pressing roll on the inner surface side of the cylinder, and the load transmitting roll is paired with the load transmitting roll. The apparatus according to claim 4, wherein the apparatus is provided on an outer member via a side wall of the body. 6. The apparatus according to claim 4, wherein a guide roll for guiding the cylindrical body is provided on the support arm.