JP5484252B2 - Can winding device - Google Patents

Description

The present invention relates to equipment for tightening up the can lid to the can body.

  When the can lid is wrapped around the can body, the can body filled with the contents is placed on the lifter, the can lid placed on the flange portion of the can body is pressed from above by the chuck member, and the can lid is held by the chuck member. The can lid and the can body are rotated while being held from the surface side, the winding roll is approached from the outside of the curled portion of the outer periphery of the can lid, and the chuck member and the winding roll are connected to the curled portion and the flange portion of the can body. It is trying to tighten while pinching between.

As such a tightening device, there are devices described in Patent Document 1 and Patent Document 2. In the winding device described in Patent Document 1, an annular convex portion that fits into an annular concave portion of the counter sink portion of the can lid is formed at the lower end portion of the chuck member that holds the can lid, and this annular convex portion is used as the counter sink portion. The outer circumferential surface of the chuck member is supported by substantially the entire surface from the counter sink portion of the can lid to the inner circumferential surface of the chuck wall that continues upward.
Further, the winding device described in Patent Document 2 does not have an annular convex portion as described in Patent Document 1 on the lower end surface of the chuck member, and therefore the chuck member does not enter the counter sink portion of the can lid. In this case, only the chuck wall in the upper position is contacted. In this case, the chuck wall of the can lid has a tapered surface inclined at a large inclination angle with respect to the vertical direction, and the chuck member is in contact with the tapered surface.

Special table 2007-526859 gazette Japanese Patent No. 3809190

In such a tightening device, in Patent Document 1, the rotational driving force of the chuck member is transmitted to the can lid over almost the entire outer peripheral surface including the annular convex portion, and in Patent Document 2, the taper surface having a relatively large area. In any case, a uniform contact state is required on the transmission surface of the driving force.
However, in recent years, speeding up of production lines has been planned, and as a result, even if the contact state between the chuck member and the can lid becomes slightly uneven, if the contact is insufficient, slipping occurs and winding is tightened. However, if the axial load is excessively increased, the can becomes unable to withstand the longitudinal load and buckling is likely to occur.
For this reason, the proposal of the winding-up technique which can respond to higher speed is calculated | required.

The present invention has been made in view of such circumstances, and can reliably transmit the rotational driving force to the can lid to prevent the occurrence of winding tightening and processing troubles and to enable high-speed winding. and to provide a tightening equipment.

The can winding device of the present invention includes a chuck member that holds the can lid from the surface side during winding, and the chuck member includes an annular protrusion that fits in the counter sink portion of the can lid, and the annular member. A tapered portion continuous from the outer peripheral surface of the protrusion and facing the inner peripheral surface of the central peripheral wall portion above the countersink portion of the can lid, and continuous from the tapered portion, and inside the shoulder portion of the can lid And a base portion that receives the pressing force of the winding roll, and a cylindrical portion is formed at the lower end portion of the annular projecting portion, and the lower end surface of the cylindrical portion is continuous from the inner peripheral surface of the cylindrical portion. Thus, the inner peripheral surface of the inner convex curved portion that protrudes downward and radially inward is formed, and the inner diameter of the cylindrical portion is outside the lower end edge of the outer peripheral surface of the inner wall portion of the counter sink portion. is smaller than the diameter, the inner peripheral surface of the inner convex curved part, the When the cylindrical portion of the Jo protrusion is fitted into the countersink section, the dimension bite into at least a portion of the inner curved portion continuous to the inner wall portion and the inner side wall lower end of the countersink section configuration and It is characterized by being.
That is, the annular protrusion of the chuck member is placed in a state where the inner peripheral surface of the counter sink portion of the can lid is hard to be inserted, and the chuck member firmly holds the can lid by the biting, and the rotational driving force thereof is the biting portion. Can be reliably transmitted by the frictional force.

In the can winding device of the present invention, the maximum amount of biting of the inner peripheral surface of the inner convex curved portion is preferably 40 to 70% with respect to the plate thickness of the can lid.
If the maximum biting amount is less than 40%, the rotational driving force may not be properly transmitted to the can lid during winding, and slipping may occur. When the lifter is lowered so as to separate the lid from the chuck member, a phenomenon occurs in which the can body is suspended without the can lid being detached. Accordingly, the maximum biting amount is preferably 40 to 70% with respect to the plate thickness of the can lid.

In the can tightening device of the present invention, the longitudinal cross-sectional shape of the counter sink part of the can lid and the annular projecting part of the chuck member is the inner convex shape when they are superimposed on a design drawing. At least a part of the inner peripheral surface of the curved portion protrudes from the outer peripheral surface of at least one of the inner wall portion or the inner curved portion of the counter sink portion in the plate thickness direction, and the inner peripheral surface of the central peripheral wall portion and the taper A gap may be formed between the outer peripheral surface of the shaped portion.
The annular protrusion of the chuck member is designed to form a gap between the outer peripheral surface of the taper-shaped portion of the chuck member and the inner peripheral surface of the central peripheral wall of the can lid in a state where the counter sink portion of the can lid is recessed. The other portions do not obstruct the biting between the protruding portion and the counter sink portion, and it is possible to make them difficult to insert.

  According to the present invention, the annular protruding portion of the chuck member is inserted into the outer peripheral surface of the inner wall portion of the counter sink portion of the can lid, so that the rotational driving force of the chuck member can be reliably transmitted from the counter sink portion to the can lid. It is possible to prevent the occurrence of defects such as poor winding and buckling of the can body and cope with high-speed winding.

It is a longitudinal cross-sectional view of the principal part which shows the fitting state to the can lid of the chuck member in 1st Embodiment of the can winding apparatus which concerns on this invention. It is the longitudinal cross-sectional view which expanded and showed the fitting part of the cyclic | annular protrusion part and counter sink part in FIG. It is a longitudinal cross-sectional view which shows the state of the biting start of the chuck member in FIG. It is a longitudinal cross-sectional view which shows the state after being wound up from the fitting state of the chuck member shown in FIG. It is the front view which showed roughly a set of winding unit in the can winding apparatus of 1st Embodiment.

Hereinafter, embodiments of a can winding apparatus and a can winding method according to the present invention will be described with reference to the drawings.
First, the can lid applied to the can winding device of the first embodiment will be described. As shown in FIGS. 1 and 2, the can lid 1 is a disc-shaped member disposed at the center portion thereof. Panel sink 2, countersink part 5 that forms an annular recess 4 that continues downward via corner part 3 on the outer periphery of panel part 2, and upwards from the outer periphery of countersink part 5 The central peripheral wall portion 6 extends while being substantially enlarged in diameter, the shoulder portion 7 is continuous from the outer peripheral edge of the central peripheral wall portion 6, and the curl portion 8 is continuous to the shoulder portion 7.

In the counter sink part 5, the inner wall part 11 connected to the corner part 3 extends so as to slightly increase in diameter as it goes vertically downward, and the inner curved part 12 and the outside from the lower edge of the inner wall part 11 to the outside. The curved portion 13 is continuous. The curved portions 12 and 13 are formed so that the inner curved portion 12 protrudes downward and radially inward so that the bottom portion of the counter sink portion 5 is formed in half, and the outer curved portion 13 is The shape is convex downward and radially outward. The outer wall portion 14 extends from the outer curved portion 13 while slightly expanding the diameter upward. The inner wall portion 11, the inner curved portion 12, the outer curved portion 13, and the outer wall portion 14 serve to counter the counter sink portion. 5 is configured.
In this case, the inner peripheral surface of both the inner curved portion 12 and the outer curved portion 13 is formed with substantially the same radius of curvature r, and is set to r = 0.15 to 0.60 mm, for example. Moreover, the nominal diameter is 204 (the outer diameter of the double tightening portion after being wound around the can body is 56.5 to 56.7 mm, and the outermost diameter of the curled portion 8 of the can lid 1 before being tightened is 62. 0 to 62.4 mm), the diameter of the curvature center position of the outer curved portion 13 is D = 48.72 to 49.72 mm. Moreover, since the inner wall part 11 and the outer wall part 14 are inclined so as to gradually approach as they go downward, the width of the annular recess 4 gradually becomes narrower as it goes downward.

The central peripheral wall portion 6 is continuous with the upper end edge of the outer wall portion 14 of the counter sink portion 5 and is continuous with the upper end edge of the first curved portion 15 and the first curved portion 15 curved so as to be convex inward. The second curved portion 16 is curved so as to be convex outward, and the continuous shape of the first curved portion 15 and the second curved portion 16 expands upward as a whole. The shape is a diameter.
The shoulder portion 7 is continuous with the upper end edge (outer peripheral edge) of the second curved portion 16 of the central peripheral wall portion 6, expands in diameter while curving so as to protrude upward, and extends outward in the radial direction. . In this case, since the second curved portion 16 of the central peripheral wall portion 6 is curved in a state in which the inner surface is inclined obliquely upward, as a whole, the second curved portion 16 has a shape that gradually increases in diameter from the bottom to the top. The shoulder portion 7 continuing to the second curved portion 16 is also enlarged from the bottom to the top.
The curled portion 8 extends radially outward continuously from the outer peripheral edge of the shoulder portion 7, and has a shape formed by folding the outer peripheral edge downward and radially inward.

On the other hand, in the can body 21 around which the can lid 1 is wound, an outward flange portion 25 is continuously connected to an upper end of a neck portion 23 whose diameter is reduced from a bottomed cylindrical can body 22 via a bent portion 24. The shape is formed.
Then, when the can body 21 is covered with the can lid 1, the outer surface side concave surface of the shoulder portion 7 of the can lid 1 faces the bent portion 24 of the can body 21, and the shoulder portion is disposed on the upper surface of the flange portion 25. The back surface from the portion 7 to the curled portion 8 is arranged to face the other.

An apparatus for winding the can body 21 and the can lid 1 is configured as follows.
As shown in FIG. 5, the can winding device 31 is placed on a turret of an unillustrated main body of a tightening machine, and a can body 21 is placed on the turret, and a can 32 is moved up and down and rotationally driven. While holding the can lid 1 from above, a chuck member 33 arranged on the surface side of the can lid 1, and the can body 21 and the can lid 1 that are rotated while being sandwiched between the chuck member 33 and the lifter 32. A plurality of winding tightening units composed of a combination of a plurality of winding rolls 34 and 35 that perform the tightening process by approaching from the radially outer position are provided at intervals in the circumferential direction of the turret. The lifter 32, the chuck member 33, and the winding rolls 34, 35 move between the lifter 32 and the chuck member 33 while moving in the circumferential direction by the turning of the turret of the winding machine body, and the can body 21 and the can lid 1 is received and these are clamped, and are wound around the winding rolls 34 and 35. FIG. 5 shows only one set of the winding unit including the lifter 32, the chuck member 33, and the winding rolls 34 and 35.

The lifter 32 includes a lifter plate 36 on which the can body 21 is placed, and a holder portion 37 that holds a spring or the like that biases the lifter plate 36 upward, and rotates together with the turret of the winding machine body. As a result, it moves up and down as shown by arrow B while moving along a ring-shaped cam (not shown) fixed to the tightening machine body, and rotates around its own axis X as shown by arrow C. It is the structure which is made.
The winding rolls 34 and 35 are formed with a molding surface on the outer peripheral surface, move away from and close to the chuck member 33 as indicated by arrows E and F, and are rotatably supported around their own axis Y. The curl portion 8 of the can lid 1 on the flange portion 25 of the can body 21 that is sandwiched and rotated between the lifter 32 and the chuck member 33 is sequentially approached from the radially outward position while being molded. It comes to tighten. That is, the first winding roll 34 approaches the curled portion 8, and the curled portion 8 of the can lid 1 is wound while being wound around the flange portion 25 of the can body 21, and then separated from the wound portion. Then, the winding roll 35 approaches to perform the tightening molding again, and finally the double tightening portion 52 is formed as shown in FIG.

The chuck member 33 is disposed on the same axis X as the lifter 32, and is formed in a sleeve shape as a whole. The chuck member 33 is directed inward in the radial direction applied from the winding rolls 34 and 35 at the time of winding. A base 41 for supporting the pressing force on the inside of the shoulder 7 of the can lid 1 is formed outward in the radial direction, and the inside of the central peripheral wall 6 of the can lid 1 is formed downward from the base 41. A curved tapered portion 42 facing the peripheral surface continuously extends, and an annular projecting portion 43 fitted into the counter sink portion 5 is formed below the tapered portion 42. The tapered portion 42 has a convex curved surface 44 facing the inner peripheral surface of the second curved portion 16 of the can lid 1 and a concave curved surface 45 facing the inner peripheral surface of the first curved portion 15. Due to the continuous shape of the convex curved surface 44 and the concave curved surface 45, the overall shape is gradually reduced from the upper side to the lower side.
Further, in a state where the annular protrusion 43 is fitted to the counter sink portion 5, the outer surfaces from the base metal portion 41 to the convex curved surface 44 and the concave curved surface 45 of the tapered portion 42 are as shown in FIG. In addition, a slight gap is formed between the corresponding shoulder portion 7 of the can lid 1 and the inner surfaces of both curved portions 16 and 15 of the central peripheral wall portion 6, with the gap formed in this portion. The tip of the annular projecting portion 43 is set so that the inner wall portion 11 of the counter sink portion 5 is difficult to fit.

As shown in the enlarged view of FIG. 2, the tip of the annular protrusion 43 has a lower end surface of the substantially straight cylindrical portion 46 continuously downward from the outer peripheral surface of the cylindrical portion 46 and radially outward. The outer convex curved portion 47 that is convex toward the inner side and the inner convex curved portion 48 that is convex downward and radially inward from the inner peripheral surface of the cylindrical portion 46 are connected at the center. The shape is different. In this case, the curvature radius R1 of the outer peripheral surface of the outer convex curved portion 47 is set slightly larger than the curvature radius R2 of the outer peripheral surface of the inner convex curved portion 48. For example, R1 = 0.42 to 0.62 mm and R2 = 0.28 to 0.48 mm. Further, the center of curvature of the outer convex curved portion 47 is disposed on the same circumference as the center of curvature of the outer curved portion 13 in the counter sink portion 5 of the can lid 1.
The cylindrical portion 46 has an inner diameter that is smaller than the outer diameter of the lower end edge of the outer peripheral surface of the inner wall portion 11 of the counter sink portion 5, that is, the maximum outer diameter of the inner wall portion 11. When fitted, the portion from the inner convex curved portion 48 to the inner peripheral surface of the lower end portion of the cylindrical portion 46 is difficult from the lower end portion of the inner wall portion 11 of the counter sink portion 5 to the outer peripheral surface of the inner curved portion 12. It comes to include.
On the other hand, the outer diameter of the cylindrical portion 46 is formed to be smaller than the minimum inner diameter of the outer wall portion 14 of the counter sink portion 5, and when fitted into the counter sink portion 5, A slight gap is formed between the wall portion 14 and the inner peripheral surface.

  The upper portion of the chuck member 33 is rotatably supported by the turret of the winding machine main body, and as the turret turns, a pinion gear engages with the rack of the winding machine main body and is indicated by an arrow G. In this way, it is driven to rotate. A rotatable knockout pad 51 that presses the panel portion 2 of the can lid 1 is provided inside the chuck member 33 so as to be movable up and down with respect to the chuck member 33.

  When the can lid 1 is wound on the can body 21 by the can tightening device 31 configured as described above, the can body 21 is sequentially supplied to each lifter 32 swung by the turret and placed on the lifter 32. After the can lids 1 are supplied one by one on the flange portion 25 of the can body 21 in a state where the can body 21 is in a state, the can body 21 and the can lid 1 are sandwiched between the lifter 32 and the chuck member 33. After being rotated and subjected to the winding process by the winding rolls 34 and 35, the rolls are discharged from the turret.

  In this series of winding operations, when the can body 21 and the can lid 1 are sandwiched between the lifter 32 and the chuck member 33, the chuck member 33 is disposed above the can lid 1 placed on the can body 21. First, the knockout pad 51 inside the chuck member 33 descends and presses the panel portion 2 of the can lid 1 so that the can body 21 and the can lid 1 can be connected to the lifter 32 and the axis of the chuck member 33. Position and fix on top.

Next, the lifter 32 is raised, and the annular protrusion 43 of the chuck member 33 is fitted to the counter sink portion 5 of the can lid 1. At this time, as shown in FIG. 3, in the annular protrusion 43, the inner peripheral surface of the inner convex curved portion 48 at the lower end first comes into contact with the outer peripheral surface of the inner wall portion 11 of the counter sink portion 5.
Then, as the lifter 32 is raised, the inner peripheral surface of the inner convex curved portion 48 of the annular projecting portion 43 gradually bites into the inner wall portion 11 of the counter sink portion 5 as shown by the chain line in FIG. For the sake of convenience, the annular protrusion 43 of the chuck member 33 is shown as being displaced with respect to the can lid 1). When the uppermost position is reached, as shown in FIGS. The portion from the inner convex curved portion 48 of 43 to the lower end portion of the tubular portion 46 is in a state of being bitten from the outside into the portion from the inner curved portion 12 of the counter sink portion 5 to the lower end portion of the inner wall portion 11. .

In this way, when the annular protrusion 43 of the chuck member 33 is fitted into the counter sink portion 5 of the can lid 1, the can lid 1 and the can body 21 receive the rotational driving force from the chuck member 33. First, the winding roll 34 approaches and curls the curled portion 8 of the can lid 1 while being wound around the flange portion 25 of the can body 21, and then moves away from the winding fastening portion, and then the winding roll 35 approaches. Then, the tightening is performed again, and finally the double tightening portion 52 is formed as shown in FIG. As described above, the inner peripheral surface from the central peripheral wall portion 6 to the shoulder portion 7 of the can lid 1 is the tapered portion of the chuck member 33 in the state shown in FIG. 1 where the chuck member 33 is fitted to the can lid 1. Although a gap is formed between the outer peripheral surface from 42 to the base metal part 41, when the winding rolls 34 and 35 approach and close the chuck member 33, the winding rolls 34 and 35 cause the radius from the outside. In order to receive a pressing force inward in the direction, at least the convex curved surface 44 of the tapered portion 42 and the inner peripheral surface of the second curved portion 16 of the can lid 1 are in contact, and the convex curved surface 44 is a fulcrum. As described above, the can lid 1 and the can body 21 are tightened between the base 41 and the winding rolls 34 and 35 while the second bending portion 16 is further bent.
FIG. 4 shows a second winding roll 35 that performs final forming among the winding rolls 34 and 35 approaching in order.
After forming the double tightening portion 52 by the curled portion 8 of the can lid 1 and the flange portion 25 of the can body 21 as described above, the chuck member 33 fitted to the counter sink portion 5 is attached to the can lid 1. The lifter 32 and the knockout pad 51 are moved down while being synchronized with each other, the can lid 1 is completely separated from the chuck member 33, the knockout pad 51 is lifted, and then the can is discharged from the turret of the winding machine. .

  FIG. 2 shows a state in which the counter sink portion 5 of the can lid 1 and the annular protrusion 43 of the chuck member 33 are overlapped on the design drawing (the same applies to FIGS. 1, 3 and 4), and the biting is performed. The part is shown hatched. The amount of biting of the annular protrusion 43 is 40% to 70% with respect to the plate thickness of the can lid 1 of 0.205 to 0.235 mm with the biting amount of the largest portion (depth from the inner surface of the can lid) D. Is done. When the biting amount D is less than 40%, the rotational driving force necessary for winding is not transmitted to the can lid 1, so that torque in the rotational direction cannot be obtained at the can lid 1, and when it exceeds 70%, the winding is tightened. It is difficult for the chuck member 33 to come out of the can lid 1 after completion.

Further, the height H of the biting portion is, for example, within 1.5 mm, preferably 1 mm from the deepest portion of the annular recess 4 forming the inner surface of the counter sink portion 5. Therefore, the upper end of the cylindrical portion 46 in the annular protrusion 43 needs to be 1.5 mm or more from the lower end of the annular protrusion 43.
In this biting state, the gap A (see FIG. 1) between the inner peripheral surface of the second curved portion 16 of the can lid 1 and the convex curved surface 44 of the tapered portion 42 of the chuck member 33 is 0.02. ˜0.10 mm. When the gap A is less than 0.02 mm, the convex curved surface 44 is formed on the can lid 1 before the annular projection 43 of the chuck member 33 is difficult to be inserted into the counter sink portion 5 when an axial load is applied. As a result, there is a risk that slipping may occur during tightening without obtaining a necessary amount of biting, and if the thickness exceeds 0.10 mm, the can lid 1 tends to wrinkle due to insufficient tightening. .

Next, the winding amount D of the annular protrusion 43 into the can lid 1 and the gap A between the inner peripheral surface of the second curved portion 16 of the can lid 1 and the convex curved surface 44 of the chuck member 33 are wound. Tables 1 and 2 show the results of experiments on the influence on tightening. Also in the following description, for convenience, the reference numerals used in the above embodiment are attached.
Table 1 shows the results of experiments on the relationship between the amount D of the annular protrusion 43 inserted into the can lid 1, the fitting torque, and the chuck removal failure. A can lid 1 having a nominal diameter of 204 (the outer diameter of the double tightened portion after the tightening is 56.5 to 56.7 mm) was used. The plate thickness is 0.22 mm. The shapes of the can lid 1 and the chuck member 33 used were overlapped on the design drawing and the corresponding part was measured. The curvature radius r of the inner curved portion 12 and the outer curved portion 13 of the counter sink portion 5 of the can lid 1 is 0.4 mm, and the curvature radius R1 of the outer surface of the outer convex curved portion 47 in the annular projection 43 of the chuck member 33 is. Is 0.52 mm, the radius of curvature R2 of the outer surface of the inner convex curved portion 48 is 0.38 mm, and a plurality of combinations in which the center of curvature of the inner curved portion 12 and the center of curvature of the outer convex curved portion 47 are different. By doing so, the bite amount D was changed. The winding speed was a speed corresponding to 2000 cans / minute.
The fitting torque is wound with a jig for hooking a torque wrench sandwiched between the bottom surface of the can 21 and the lifter 32, and the winding roll 35 is released at a position closest to the second winding roll 35; The torque in the rotational direction was measured with a torque wrench. The numerical value in the table | surface has shown the average value in 20 cans measured. An average value of 2.5 N · m or more and an individual value of 1.8 N · m or more was regarded as acceptable (◯). The chuck unsuccessful defect indicates that the can has not been spontaneously detached (dropped) from the chuck member 33 after the end of winding. The number of cans in which 20 cans were tightened and a chuck failure occurred is shown. A product that does not cause a chuck failure is a pass (◯).

Table 2 shows the relationship between the clearance (clearance) A between the inner peripheral surface of the second curved portion 16 of the can lid 1 and the convex curved surface 44 of the chuck member 33, the fitting torque, and the drop strength. Results are shown. As the can lid, one having a nominal diameter of 204 and a plate thickness of 0.22 mm was used, and in both cases, the amount D of the annular protrusion 43 into the can lid 1 was set to 50%. The tightening speed was equivalent to cans / minute. The dimension A in the table is a numerical value obtained by superimposing the design shape of the can lid 1 and the chuck member 33 used in the experiment on the design drawing, and measuring the corresponding part. The-(minus) dimension and 0 mm are When the annular protrusion 43 of the chuck member 33 is fitted to the counter sink portion 5 of the can lid 1, the inner peripheral surface of the second curved portion 16 of the can lid 1 and the convex curved surface 44 of the chuck member 33 are in contact with each other. Is meant to do.
The fitting torque is the same as the measurement method in Table 1. The numerical value in the table | surface has shown the minimum value in 20 cans measured. Falling leaks, 20 cans dropped on an iron plate in an inverted posture with the can lid facing down from a height of 80 cm, filled with water and wrapped with carbonated water or nitrogen filled with internal pressure. The number of cans in which leakage occurred was measured. Those that do not cause leakage cans are accepted (◯).

Further, the pressure resistance of the can lid 1 was measured as follows. The can lid 1 is wound around the can body 21, an internal pressure is applied with carbonated water, and the internal pressure is measured when the reverse buckling occurs so that the vicinity of the counter sink portion of the can lid is raised outward. Strength. A can lid having a nominal diameter of 204 and having a bite amount of 40% as described above was used as an example, and a bite amount of 0% was used as a comparative example.
The results are shown in Table 3.

As is clear from these experimental results, the can lid 1 is rotated with an appropriate fitting torque by setting the amount D of the chuck member 33 inserted into the can lid 1 to 40 to 70% of the plate thickness of the can lid 1. In addition, there was no defect in chucking after winding. Further, when the clearance (clearance) A between the inner peripheral surface of the second curved portion 16 of the can lid 1 and the convex curved surface 44 of the chuck member 33 is in the range of 0.02 to 0.10 mm. In addition, an appropriate fitting torque could be transmitted to the can lid 1 and no leakage occurred in the drop test. It can be seen that the pressure strength is also improved over the conventional one (comparative example).
In addition, it was confirmed that the chuck member 33 was caught in the corresponding portion of the counter sink portion 5 in the can lid of the can that was wound in the proper range of the biting amount D.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, the central peripheral wall portion of the can lid and the tapered portion of the chuck member are configured by a continuous shape of two curved portions in the embodiment, but are configured by one curved portion, a substantially straight tapered surface, or the like. May be.
Moreover, although it applied to the thing whose nominal diameter of a can is 204, 202 (the outer diameter of a double winding part is 53.6-54.4 mm, and the outermost diameter of the curl part of a can lid before winding is 59. 2 to 59.6 mm) or 206 (the outer diameter of the double tightening portion is 59.2 to 59.4 mm, and the outermost diameter of the curled portion of the can lid before winding is 64.5 to 64.9 mm) It can also be applied to.

DESCRIPTION OF SYMBOLS 1 Can lid 2 Panel part 3 Corner part 4 Annular recessed part 5 Counter sink part 6 Center peripheral wall part 7 Shoulder part 8 Curl part 11 Inner side wall part 12 Inner curved part 13 Outer curved part 14 Outer side wall part 15 First curved part 16 2nd Bending portion 21 Can body 22 Can body 23 Neck portion 24 Bending portion 25 Flange portion 31 Tightening device 32 Lifter 33 Chuck member 34, 35 Tightening roll 41 Base portion 42 Tapered portion 43 Annular protrusion 44 Convex curved surface 45 Concave curved surface 46 cylindrical portion 47 outer convex curved portion 48 inner convex curved portion 51 knockout pad

Claims (3)

  A chuck member that holds the can lid from the surface side when tightening, the chuck member is continuous from the annular protrusion fitted into the counter sink portion of the can lid, and the outer peripheral surface of the annular protrusion; A tapered portion facing the inner circumferential surface of the central peripheral wall portion above the counter sink portion of the can lid, and a continuous portion from the tapered portion, and receiving the pressing force of the winding roll inside the shoulder portion of the can lid A cylindrical portion is formed at the lower end portion of the annular projecting portion, and continuously downward and radially inward from the inner peripheral surface of the cylindrical portion on the lower end surface of the cylindrical portion. An inner peripheral surface of the inner convex curved portion that is convex toward the inner surface is formed, and an inner diameter of the cylindrical portion is formed to be smaller than an outer diameter of a lower end edge of the outer peripheral surface of the inner wall portion of the counter sink portion. The inner peripheral surface of the curved portion is the front of the tubular portion of the annular protrusion Can winding characterized in that it is dimensioned so that at least a part of the inner curved part continuous with the inner wall part of the counter sink part and the lower end of the inner wall part is inserted when fitted into the counter sink part. Fastening device.   The can tightening device according to claim 1, wherein the maximum biting amount of the inner peripheral surface of the inner convex curved portion is 40 to 70% with respect to the plate thickness of the can lid.   The longitudinal sectional shape of the counter sink part of the can lid and the annular projecting part of the chuck member is at least one of the inner peripheral surface of the inner convex curved part when they are superimposed on the design drawing. A portion protrudes from the outer peripheral surface of at least one of the inner wall portion or the inner curved portion of the counter sink portion in the thickness direction, and between the inner peripheral surface of the central peripheral wall portion and the outer peripheral surface of the tapered portion. The can winding device according to claim 1 or 2, wherein a gap is formed.

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