Patent Publication Number: US-2021187587-A1

Title: Bottle can manufacturing apparatus and bottle can manufacturing method

Description:
TECHNICAL FIELD 
     The present invention relates to a bottle can manufacturing apparatus and a bottle can manufacturing method. 
     BACKGROUND ART 
     A bottle can in which beverages or the like is to be filled is a can container having a bottle shape in which a mouth portion has a reduced diameter, and one with a re-pluggable screw type cap-attached container is generally used. 
     For example, in the case of an aluminum can, in a bottle can manufacturing process, an aluminum plate is punched out and subjected to shallow squeezing to form a base cup, the formed cup is squeezed and drawn to form a can barrel, the can barrel is trimmed to align a height of an upper part thereof, processes such as cleaning, printing, and inner coating are performed as necessary, and then a mouth portion formation step is performed. In the mouth portion formation step, necking, trimming, formation of a screw part, formation of a curled part, etc., are performed, and also in this case, trimming for adjusting a top height of the mouth portion is performed before the screw part and the curled part are formed. 
     In the trimming performed in the mouth portion formation step, adjustment of a can height is performed by cutting an upper end part thereof. A trimming apparatus used in this step is, for example, an apparatus or the like which includes a cutting tool for cutting an opening edge of the can body, a guide part disposed inside an opening part of the can body, and a suction duct for sucking shavings generated by cutting with the cutting tool (for example, see PTL 1). 
     CITATION LIST 
     Patent Literature 
     
         
         [PTL 1] Japanese Patent Application Publication No. 2005-40803 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     According to the conventional apparatus mentioned above, since shavings are generated by trimming in the mouth portion formation step, it is difficult to completely remove fine shavings even when the trimming apparatus having the suction duct is used as in the conventional technique mentioned above, and thus it is inevitable to clean and dry the can body after the mouth portion formation step. 
     Cleaning and drying of the can body performed after the mouth portion formation step greatly affects productivity of the bottle can since processing time therefor is added. For this reason, in order to obtain high productivity, trimming (adjustment of the can height) that does not generate shavings in the mouth portion formation step is required so that cleaning and drying become unnecessary. 
     The present invention has an object to cope with such situations. That is, an object of the present invention is to provide a bottle can manufacturing apparatus in which no fine shavings are generated in a mouth portion formation step and cleaning and drying after the mouth portion formation step are not unnecessary. 
     Solution to Problem 
     In order to solve such problems, the present invention has the following configurations. 
     A bottle can manufacturing apparatus for forming a mouth portion in a bottomed cylindrical can body includes necking processing parts each of which performs necking processing while moving the can body around a rotation axis, and trimming processing parts each of which performs slit processing on an upper end part of the can body to perform trimming while moving the can body around the rotation axis and rotating the can body, and wherein a plurality of the necking processing parts are continuously disposed, and the trimming processing parts are continuously disposed for at least one of the necking processing parts. 
     A bottle can manufacturing method for forming a mouth portion in a bottomed cylindrical can body includes: performing a plurality of stages of necking processing in sequence in which each stage of the necking processing is performed while moving the can body around a rotation axis, and performing slit processing on an upper end part of the can body to perform trimming in sequence with at least one stage of the necking processing while moving the can body around the rotation axis and rotating the can body. 
     Advantageous Effects of Invention 
     According to the present invention having such features, since there can be performed manufacturing of a bottle can in which no fine shavings are generated in a mouth portion formation step and cleaning and drying after the mouth portion formation step are unnecessary, productivity of the bottle can be significantly improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an explanatory diagram showing a bottle can manufacturing apparatus according to an embodiment of the present invention. 
         FIG. 2  is an explanatory diagram showing a rotating turret of a necking processing part. 
         FIG. 3  is an explanatory diagram showing an operation of a necking tool of the necking processing part, (a) shows a state immediately after a can body is supplied to the rotating turret, (b) shows a state in which the rotating turret is rotated thereafter, and (c) shows a state in which an upper end part of the can body is inserted between an inner tool and an outer tool thereafter. 
         FIG. 4  is an explanatory diagram showing a trimming processing part. 
         FIG. 5  is an explanatory diagram showing a trimming tool of the trimming processing part. 
         FIG. 6  is a cross-sectional view taken along line A-A of  FIG. 5 , (a) shows a state in which a gap is formed between the inner tool and the outer tool, and (b) shows a state in which slit processing is performed by the inner tool and the outer tool. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the figures. In the following description, the same reference numeral in different figures indicates a part having the same function, and repeated descriptions of each figure will be omitted as appropriate. 
     As shown in  FIG. 1 , a bottle can manufacturing apparatus  1  is for forming a mouth portion in a bottomed cylindrical can body and includes a plurality of necking processing parts  2  and a trimming processing part  3 . Each necking processing part  2  includes a rotating turret  21  that performs necking processing while moving the can body around a rotation axis  20  thereof, and the trimming processing part  3  includes a rotating turret  31  that performs trimming processing while moving the can body around the rotation axis  30  and rotating the can body. 
     In the necking processing parts  2 , one stage of necking processing is performed by one necking processing part  2 . The plurality of necking processing parts  2  are continuously disposed via a coupling turret  4 , and the can body supplied to one rotating turret  21  via the coupling turret  4  undergoes one stage of necking processing while moving around the rotation axis  20  by a predetermined angle (for example, 120°), and is subjected to multi-stage necking processing by being processed in sequence by the plurality of necking processing parts  2 . 
     The trimming processing part  3  is continuously disposed with one of the necking processing parts  2 , and eliminates an upper end part of the can body by a predetermined height by slit processing in order to perform slit processing of the upper end part of the can body using the one trimming processing part  3  to adjust a height of the can body to a predetermined height. The can body transferred from one necking processing part  2  to the coupling turret  4  is supplied to the rotating turret  31  of the trimming processing part  3  via the coupling turret  4 . The can body supplied to the rotating turret  31  is subjected to slit processing of the upper end part while rotating when it moves around the rotation axis  30  by a predetermined angle (for example, 120°). 
     As shown in  FIG. 2 , the rotating turret  21  of each of the necking processing parts  2  includes a plurality of can body holding parts  21 P around the rotation axis  20 . In the illustrated example, ten can body holding parts  21 P are provided around the rotation axis  20  at every angle of 36°. One can body is held in each of the can body holding parts  21 P, and when the rotating turret  21  makes one rotation, one stage of necking processing is performed for the can bodies corresponding to the number (ten in the illustrated example) of can body holding parts  21 P. The can bodies held by the can body holding parts  21 P move around the rotation axis  20  with the rotation of the rotating turret  21 . 
     As shown in  FIG. 3 , necking processing is performed for the can body W held by each can body holding part  21 P using a necking tool  22 . One necking tool  22  corresponds to one can body holding part  21 P, and the necking tool  22  moves in synchronization with the rotation of the rotating turret  21 . 
     In the necking tool  22 , an inner tool  22 B and an outer tool  22 C are arranged around a center shaft  22 A arranged coaxially with a can axis O. The outer tool  22 C has an annular shape, and an inner diameter thereof is smaller by about 1 to 2 mm than an outside diameter of an opening part of the can body W. The inner tool  22 B has an outside diameter which is smaller by about 1 to 2 mm than an inner diameter of the opening part of the can body W and is disposed inside the can body W. In addition, by inserting the upper end part of the can body W between the inner tool  22 B and the outer tool  22 C, necking processing is performed on the upper end part of the can body W. 
     The inner tool  22 B and the can body holding part  21 P move forward and backward in a direction of the can axis O in synchronization with the rotation of the rotating turret  21 . Immediately after the can body W is supplied from the coupling turret  4  to the rotating turret  21 , the necking tool  22  and the can body holding part  21 P are separated from the can body W as shown in  FIG. 3( a ) . Thereafter, when the rotating turret  21  rotates, as shown in  FIG. 3( b ) , the can body holding part  21 P moves toward the can body W and holds a bottom part of the can body W, and the inner tool  22 B moves toward the can body W and is inserted into the opening part of the can body W. Thereafter, the inner tool  22 B, the can body W, and the can body holding part  21 P integrally move toward the outer tool  22 C, and as shown in  FIG. 3( c ) , the upper end part of the can body W is inserted between the inner tool  22 B and the outer tool  22 C, so that one stage of necking processing is performed. 
       FIG. 4  shows the trimming processing part  3 . In the illustrated example,  18  can body holding parts (not shown) are provided on the rotating turret  31  of the trimming processing part  3 , and one trimming tool  32  is provided for each can body holding part. Each can body holding part is configured to be rotatable around the can axis, and the can body held by each can body holding part rotates with rotation of the can body holding part. Each trimming tool  32  includes an inner tool  32 A and an outer tool  32 B. The inner tool  32 A is arranged inside the can body, the outer tool  32 B is arranged outside the can body, and the upper end part of the can body W is sandwiched between a cutting part of the inner tool  32 A and a cutting part of the outer tool  32 B and is sheared while the can body W rotates, whereby the slit processing is performed on the upper end part of the can body. 
     Similar to the necking processing part  2 , the trimming processing part  3  performs slit processing with the rotation of the rotating turret  31 . That is, the can body held by the can body holding part of the rotating turret  31  is subjected to slit processing using the inner tool  32 A and the outer tool  32 B while moving around the rotation axis  30  and rotating. 
     As shown in  FIG. 5 , the outer tool  32 B of the trimming tool  32  has a cutting part  32 B 1  and a relief part  32 B 2  around a rotation axis thereof. The relief part  32 B 2  is provided around the rotation axis to take up a predetermined angle (for example, 160°) out of 360°, and a part taking up the remaining angle (for example, 200°) forms the cutting part  32 B 1 . Also, the inner tool  32 A of the trimming tool  32  has a cutting part  32 A 1  on the entire circumference around the rotation axis. 
     A distance between the axes of the inner tool  32 A and the outer tool  32 B is constant, a gap is formed between the inner tool  32 A and the outer tool  32 B as shown in  FIG. 6( a )  at the timing when the relief part  32 B 2  approaches the inner tool  32 A, and at that timing, the upper end part of the can body W is inserted between the inner tool  32 A and the outer tool  32 B. 
     Then, as shown in  FIG. 6( b ) , the can body W is sandwiched between the cutting part  32 B 1  of the outer tool  32 B and the cutting part  32 A 1  of the inner tool  32 A with the rotation of the outer tool  32 B and the inner tool  32 A, and the entire circumference of the can body W is sheared while the can body W rotates, whereby slit processing is performed on a periphery of the upper end part of the can body W. As a result, the upper end part of the can body W is separated from the can body into a single ring shape and recovered by a recovery apparatus (not shown). 
     In the bottle can manufacturing apparatus  1  shown in  FIG. 1 , the number of necking processing parts  2  can be appropriately set in accordance with the number of stages of the necking processing. In addition, after predetermined necking processing are performed, a first stage of trimming processing is performed by the trimming processing part  3 . Thereafter, formation of a bead part or a screw part is performed on the mouth portion, and if necessary, necking processing is carried out in several stages by the necking processing parts  2 . Then, after a second stage of trimming processing is carried out, formation of a curled part is performed, whereby the bottle can in which the mouth portion has been formed can be obtained. 
     Further, the height of the upper end part of the can body W may become uneven when a plurality of stages of necking processing is performed, and a problem may occur if the next stage of necking processing is performed in the above state. For that reason, the trimming processing part  3  may be provided in the middle of the plurality of necking processing part  2  as necessary. 
     As a result, according to the bottle can manufacturing apparatus  1  according to the embodiment of the present invention, a ring-shaped cut end is generated by the slit processing using the trimming processing part  2 , but formation of the mouth portion can be completed without generating fine shavings. This eliminates the need for cleaning and drying after the trimming process, and can significantly improve the productivity of the bottle can. 
     REFERENCE SIGNS LIST 
     
         
           1  Bottle can manufacturing apparatus 
           2  Necking processing part 
           3  Trimming processing part 
           20 ,  30  Rotation axis 
           21 ,  31  Rotating turret 
           4  Coupling turret 
           21 P Can body holding part 
           22  Necking tool 
           22 A Center shaft 
           22 B Inner tool 
           22 C Outer tool 
           32  Trimming tool 
           32 A Inner tool 
           32 B Outer tool 
           32 A 1 ,  32 B 1  Cutting part 
           32 B 2  Relief part