JP2018104096A - Bottle can and bottle can with cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely close a cap.SOLUTION: A bottle can has a male screw part 9 with a screw part 9d of predetermined height of one round or more on an upper-end side of a neck part 7 of a can body 1 having a can axis C in the center, and a curl part 10 on the upper end side, and the screw part 9d of predetermined height of the male screw part 9 is designed to have, in a cross section along the can axis C, a difference of 0.4 mm or larger between a screw thread radius from the can axis C to a crest of a screw thread 9a and a screw root radius of a screw root 9f, adjoining a lower end side of the screw thread 9a, from the can axis C to a root bottom. The screw part 9d of predetermined height has a multi-stage part 9e formed having two or more screw threads 9a in a cross section along the can axis C, a screw thread radius of the multi-stage part 9e from the can axis C to a crest of the screw thread 9a is such that in a state in which the curl part 10 is formed, a screw thread radius R1 of the screw thread 9a of a first stage most on the side of the curl part 10 is smaller than a screw thread radius R2 of the screw thread 9a of the second stage adjoining a lower end side of the screw thread 9a of the first stage at least on the side of a screw beginning part 9c of the screw part 9d of predetermined height.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bottle can with a screw in which a male screw portion is formed on the outer periphery of an upper end portion, and a bottle can with a cap in which a female screw portion is screwed onto a male screw portion of the bottle can and a cap is attached. It is.

  As a method of forming such a screw-equipped bottle can, for example, in Patent Document 1, a curled portion formed by folding the tip of the bottle can body on the outer periphery of the bottle can body, and the tip of the cap portion from the tip side toward the bottom of the can. In the method for forming a cap portion of a bottle can body that forms a thread portion having a thread region having a plurality of steps facing each other, when the screw portion is formed before forming the curled portion, the cap portion is positioned on the tip side of the cap portion of the bottle can body. It is described that the height of the first stage thread is formed lower than the other stage thread within an angle range of at least 90 degrees from the screw starting portion that does not include an incomplete thread and functions effectively as a screw. Yes.

  In the bottle can body in which the base part is formed by such a forming method, the first-stage thread of the thread part is crushed and expanded in diameter by receiving a pressing force in the curl caulking process when forming the curled part. As a result, the first-stage screw thread has substantially the same height as the other-stage screw threads, and all the screw threads can be formed satisfactorily. In addition, this Patent Document 1 also describes that when the cap is attached to the bottle can in which the curl portion is formed in this way, the cap is attached in a shape corresponding to the shape of the base portion, That is, the cap has a female screw portion that is shaped so as to follow the screw portion that is the male screw portion of the bottle can.

Japanese Patent No. 4,570,838

  By the way, a beverage can made of such a bottle can is a beverage that can be carried around or dropped by closing the cap after removing the cap attached to the male screw part and drinking a part of the filled beverage. Since it does not spill out, it is easy to handle, and it is not necessary to drink the filled beverage all at once, which is a feature of beverage cans using pull tabs and the like.

  However, in the bottle can molded by the molding method described in Patent Document 1, the first-stage thread of the male thread portion has a height substantially equal to the thread of the other-stage as described above, and accordingly, Since the valley of the female threaded portion of the cap also has substantially the same depth, when the cap is closed, the valley is in sliding contact with the thread from when the female thread is screwed into the first thread. The friction increases and the friction increases as the cap is screwed. For this reason, the rotational force required at the time of plugging, that is, reseal torque, is large from the beginning of screwing of the cap and increases as the cap is screwed, which may make it difficult to perform reliable plugging.

  Further, in recent years, in order to save resources and energy, the thickness of the can body has been reduced even in such bottle cans, and the conventional molding load of the curled portion, for example, a capping load of about 1000N to 1200N, Alternatively, even if the load is less than that, the first-stage screw thread is crushed and buckled, and the diameter is easily increased. For this reason, even when the curl portion is molded with respect to the conventional molding load, even if the first stage thread is set to have a height substantially equal to the other stage thread, the thinned bottle can Then, there is a possibility that the first-step screw thread is greatly expanded and protrudes from the other-step screw thread.

  The present invention has been made under such a background. The initial friction of the cap is small, the reseal torque is small, and it is possible to perform reliable closure, and the first-stage screw thread has two stages. It is an object of the present invention to provide a bottle can and a bottle can with a cap that can surely prevent protruding from the thread of the eye.

  In order to solve the above-mentioned problems and achieve such an object, the bottle can of the present invention has a shoulder whose diameter is reduced from the body part of the bottomed cylindrical can body centering on the can axis toward the upper end side. Part, a neck part extending further from the shoulder part toward the upper end side, a male thread part having one or more turns at a predetermined height provided on the upper end side of the neck part, and an upper end of the male thread part A bottle can provided with a curled portion formed by folding the upper end of the can body to the outer peripheral side on the side, wherein the predetermined height screw portion in the male screw portion is the cross section along the can axis, The difference between the thread radius from the can axis to the top of the thread and the thread valley radius from the can axis to the bottom of the thread valley adjacent to the lower end of the thread is in a range of 0.4 mm or more. In the cross section along the can axis, the predetermined height screw portion has 2 A multi-step portion having the above thread is formed, and the thread radius from the can shaft to the top of the screw thread in the multi-step portion is at least along the screw thread in the state where the curl portion is formed. The thread radius of the first thread located closest to the curl part on the screw start part side where the difference in the predetermined height thread part is within the range as it goes toward the lower end side of the male thread part Is smaller than the screw thread radius of the second screw thread adjacent to the lower end of the can body of the first screw thread.

  Further, the bottle with a cap of the present invention is a cap attached with a bottomed cylindrical cap having a top plate portion and a peripheral wall portion from the curled portion of the bottle can to the male screw portion. The bottle has a female screw part formed so as to follow the male screw part of the bottle can on the inner periphery of the peripheral wall part. The thread radius of the first stage thread located on the curl side is made smaller than the thread radius of the second stage thread adjacent to the lower end of the can body of the first stage thread. It is characterized by being.

  In the bottle can having the above-described configuration, the thread radius of the multi-stage portion of the thread portion at the predetermined height of the male screw portion is at least the predetermined height in a state where the curl portion is formed on the upper end side of the male screw portion. On the screw start portion side of the screw portion, the screw radius of the first step screw thread located closest to the curl portion side is the second step screw screw thread adjacent to the lower end side of the can body of the first step screw thread. Therefore, the female screw portion of the cap of the bottle can with cap formed so as to follow the male screw portion is positioned on the top plate portion side of the predetermined height screw portion. The trough bottom radius of the second trough adjacent to the lower end side of the cap becomes larger than the trough bottom radius from the can shaft of the trough of the step.

  For this reason, when the cap once removed is screwed onto the male screw portion again to close the cap, at the beginning of the screwing, the first step with a small thread radius is placed in the valley of the female screw portion of the second and subsequent caps with a large root bottom radius. Since the thread of the male thread portion of the eye comes into sliding contact, the friction is small and the reseal torque can be suppressed to be small on average. On the other hand, at the final stage of plugging, the first and second screw threads and valleys with corresponding thread radii and valley bottom radii are screwed together, so that a sealing property can be secured and drinking is possible. The beverage does not leak out and can be reliably plugged. Further, since the thread radius of the first stage thread is smaller than the thread radius of the second stage thread in the state where the curled part is formed, the curled part is formed even in a thin bottle can. Of course, even when the cap is attached, there is no possibility that the first-stage screw thread protrudes. The portion where the difference between the thread radius from the can axis to the top of the thread and the thread valley radius from the can axis to the bottom of the thread valley is below the above range in the male thread portion is the male part of the bottle can. It becomes an incomplete screw part that does not function effectively as a screw part.

  Here, the screw thread radius of the first stage screw thread is within a range of at least 90 ° from the screw starting portion of the predetermined height screw portion to the twist direction of the male screw portion around the can shaft. Thus, it is desirable that the thread radius of the second stage thread is smaller than the thread radius. If the thread radius of the first stage thread of the male thread is only smaller than the thread radius of the second stage thread up to a position smaller than this range, The second trough portion of the female screw portion of the cap immediately comes into sliding contact with the screw thread, and there is a possibility that the reseal torque cannot be sufficiently reduced without suppressing the friction.

  As described above, according to the present invention, it is possible to perform a reliable opening / closing stopper while suppressing resealing torque while ensuring sealing performance and enabling reliable closure, and a thin bottle can However, when attaching the cap, the first stage thread does not protrude beyond the second stage thread.

It is a partially broken side view showing one embodiment of the bottle can of the present invention. It is an enlarged side view of the upper end part of embodiment shown in FIG. It is a partially broken expanded side view which shows one Embodiment of the bottle can with a cap of this invention which attached the cap to embodiment shown in FIG.

  1 and 2 show one embodiment of the bottle can of the present invention, and FIG. 3 shows one embodiment of the bottle can with a cap of the present invention. As shown in FIG. 1, the bottle can of the present embodiment has a bottom 2 and an outer periphery formed integrally with the bottom 2 and extending from the outer periphery of the bottom 2 to the upper end side (upper side in FIG. 1). It has a generally multi-stage bottomed cylindrical shape centering on a can shaft C provided with a portion 3.

  A dome portion 2a having a substantially arc-shaped cross section that is recessed inwardly in the can axis C direction (upper end side of the can body 1) is formed in the bottom portion 2 at the center, and the outer periphery of the dome portion 2a is in the can axis C direction. An annular convex portion 2b that protrudes to the outside (the lower end side of the can body 1) is formed continuously in the circumferential direction around the can axis C. In addition, the outer peripheral portion 3 has a cylindrical body portion 5 centering on the can shaft C in order from the bottom portion 2 to the opening portion 4 on the upper end side of the can body 1, and gradually with a constant inclination toward the upper end side. A frustoconical shoulder 6 having a reduced diameter, a cylindrical neck 7 extending further from the shoulder 6 toward the upper end, a bulging portion 8 projecting from the upper end of the neck 7 to the outer peripheral side, and a male screw portion 9 and a curled portion 10 are formed.

  In order to manufacture such a bottle can, first, a cup-shaped material with a shallow depth is manufactured by punching a metal plate such as aluminum or aluminum alloy into a disk shape and performing a drawing process in a cupping press process by a cupping press machine. To do. Next, the cup-shaped material is subjected to redrawing and ironing in a DI press process by a DI press machine and stretched in the direction of the can axis C, whereby the dome portion 2a and the annular convex portion 2b are formed on the bottom portion 2. A bottom cylinder (DI can) is formed.

In this embodiment, the metal plate formed into a cup-shaped material in the cupping press process is an aluminum alloy plate of A3004 or A3104 in JIS H 4000 having a base plate thickness of 0.285 mm to 0.365 mm, and is 205 ° C. × 20. A 0.2% proof stress after minute baking is in the range of 235 N / mm ^{2 to} 265 N / mm ² . In addition, the bottomed cylindrical body formed from the cup-shaped material has a cylindrical portion around the can axis C on the outer peripheral portion, and the outer diameter of the cylindrical portion is outside the body portion 5 of the can body 1. A constant outer diameter substantially equal to the diameter. However, the thickness of the upper end side portion of this cylindrical portion is in the range of 0.180 mm to 0.225 mm, while the thickness of the lower end side portion is in the range of 0.110 mm to 0.135 mm, Thinner than the side part.

  The bottomed cylindrical body formed in this way is cleaned and dried in the first cleaning step, and then the inner and outer surfaces are painted and baked in the coating step. And the bottomed cylindrical body to which the coating has been applied, in the bottle neck forming step by the bottle necker, the lower end side of the upper end side portion of the cylindrical portion is reduced in diameter by a mold, and the shoulder portion 6 and the neck portion 7 are formed, Next, the upper end side of the neck portion 7 is expanded by a diameter expanding tool to form the bulging portion 8, and the threading process is further performed on the upper end side of the bulging portion 8 to form the male screw portion 9. After that, the upper end side of the male screw portion 9 is folded back to the outer peripheral side and curled and then crushed by throttle processing to form a curled portion 10, which is formed into a can body 1 of a bottle can as shown in FIG. The The external diameter of the male threaded portion 9 is approximately 30.4 mm to 34.4 mm when a cap having a nominal diameter of 33 mm is attached, and 35.0 mm to 39.3 when a cap having a nominal diameter of 38 mm is attached. 0 mm.

  After the can body 1 thus molded is cleaned and dried in the second cleaning process, the inspection process is inspected for the presence of pinholes, adhesion of foreign matters on the outer surface, scratches, dirt, printing defects, etc. After being transported and filled with contents such as a beverage, a cap 11 is attached and sealed from the curled portion 10 to the male screw portion 9 and the bulging portion 8 so as to cover the opening 4 as shown in FIG. Shipped. In addition, during the above steps of the can body 1 or during each step, trimming for cutting the upper edge of the bottomed cylindrical body and bottom reforming for re-forming the cross-sectional shape of the annular projection 2b at the bottom as necessary. Is done.

  Thus, when the cap 11 is attached to the can body 1 of the bottle can, the disc-shaped top plate portion 11a made of aluminum or aluminum alloy and the cylindrical peripheral wall portion 11b are integrally provided in the same manner as the can body 1. A bottomed cylindrical cap material is placed from the curled portion 10 to the male screw portion 9 and the bulging portion 8 so as to close the opening 4 of the can body 1 with the opening facing downward, and is applied by the pressure block of the capping device. While the top plate portion 11a is pressed by the curl portion 10 and drawn, the screw processing roll is pressed against the peripheral wall portion 11b and is subjected to screw processing so as to follow the male screw portion 9, whereby the female screw portion is formed on the inner periphery. 11c is formed, and the lower end edge of the peripheral wall portion 11b is wound around the bulging portion 8 by the bottom winding roll. A sealing liner 11d is provided in advance on the back surface of the top plate portion 11a.

  Here, the male threaded portion 9 of the can body 1 is gradually twisted toward the lower end as it goes in the clockwise direction in plan view from the curled portion 10 side, and the thread 9a gradually protrudes to the outer peripheral side at the incomplete threaded portion 9b. Along the thread 9a toward the lower end side of the male thread portion 9, at the screw start portion 9c, the thread radius R1 from the can shaft C to the apex of the thread 9a and the lower end side of the thread 9a The difference between the screw valley radius r1 from the can axis C to the bottom of the adjacent screw valley 9f is in the range of 0.4 mm or more, and the predetermined height screw portion 9d that functions effectively as the male screw portion 9 of the bottle can. It becomes. That is, when the difference is less than the above range, the height from the bottom of the screw valley 9f to the top of the screw thread 9a adjacent to the upper end becomes small, and the cap 11 cannot be securely screwed. The upper limit of this difference is, for example, 1.0 mm. If the upper limit is exceeded, for example, the depth from the top of the thread 9a to the bottom of the thread valley 9f increases and the inner diameter of the male thread 9 also decreases. In addition, it becomes difficult to drink contents such as beverages, and neither of them effectively functions as the male screw portion 9 of the bottle can. Further, the male screw portion 9 gradually retreats to the inner peripheral side when the screw thread 9a makes one or more turns (for example, 2.2 turns) in the predetermined height screw portion 9d, and becomes the incomplete screw portion 9b again. It sunk in the upper end part of the bulging part 8.

  Accordingly, the male screw portion 9 is formed with a multi-step portion 9e having two or more screw threads 9a in a cross section along the can axis C at the position of the screw start portion 9c of at least the predetermined height screw portion 9d. The thread radius from the can shaft C to the top of the thread 9a in the multi-stage part 9e is at least a predetermined height of the thread part 9d with the curled part 10 formed on the upper end side of the male thread part 9. On the screw start portion 9c side, the thread radius R1 of the first-stage screw thread 9a located closest to the curl section 10 side is the second-stage screw adjacent to the lower end side of the can body 1 of the first-stage screw thread 9a. The thread 9a is smaller than the thread radius R2. Here, the difference R2-R1 between the thread radius R1 of the first stage thread 9a and the thread radius R2 of the second stage thread 9a is, for example, in the range of 0.1 mm to 0.5 mm, preferably The range is 0.1 mm to 0.3 mm.

  In the present embodiment, the thread radius R1 of the first stage thread 9a is set so that the male thread portion 9 is centered on the can axis C from the screw start portion 9c of the predetermined height thread portion 9d as shown in FIG. In the range L of at least 90 ° toward the torsional direction, the thread radius R2 of the second-stage thread 9a is made smaller than the thread radius R2, and from the point where the range L is exceeded, the second-stage thread gradually increases. It becomes the thread radius R2 of the thread 9a of the eye. However, the range L does not exceed one turn from the screw start portion 9c of the predetermined height screw portion 9d.

  Here, in order to mold the can body 1 having such a male screw portion 9, for example, in the screw forming apparatus described in Patent Document 1, the first-stage screw forming portion of the core and the second and third steps The difference in height from the screw forming portion is determined by the amount of diameter expansion or capping load (for example, 800 N to 900 N) due to crushing of the first stage thread 9 a when forming the curled portion 10 by thinning the can body 1 or the cap 11. ), And a larger value may be set.

  Furthermore, in this embodiment, in the multi-step portion 9e of the male screw portion 9, the height from the bottom of the screw valley 9f adjacent to the lower end side of the first-step screw thread 9a to the apex of the first-step screw thread 9a is The height from the bottom of the screw valley 9f adjacent to the lower end side of the second-stage screw thread 9a to the apex of the second-stage screw thread 9a is made equal. The screw trough radii r1 and r2 from the can axis C to the bottom of the thread trough 9f adjacent to the lower end side are the thread trough radii of the first thread trough 9f than the thread trough radius r2 of the second thread trough 9f. By reducing r1, the thread radius R1 of the first stage thread 9a is formed to be smaller than the thread radius R2 of the second stage thread 9a. The thread height from the bottom of the thread valley 9f between the first and second stage threads 9a to the top of the first stage thread 9a is, for example, less than 0.7 mm, and the second stage thread The thread height to the apex of 9a is, for example, 0.7 mm or more.

  On the other hand, in the cap 11, as described above, the threading roll of the capping device is pressed against the peripheral wall part 11b and is threaded so as to follow the male threaded part 9, thereby forming the female threaded part 11c. Therefore, in the cross section of the male screw portion 9 at the position corresponding to the multi-step portion 9e, the valley bottom radius from the can shaft C to the valley bottom of the valley portion of the female screw portion 11c is 2. It becomes smaller than the valley bottom radius of the valley of the step.

  For this reason, when the cap 11 once removed is screwed into the male threaded portion 9 of the bottle can again to close the cap, the trough portion of the female threaded portion 11c of the cap 11 of the second or later stage having a large trough bottom radius is initially screwed. In addition, the first screw thread 9a having a small screw thread radius R1 of the male screw part 9 comes into sliding contact. Accordingly, the friction between the male screw portion 9 and the female screw portion 11c at the beginning of screwing is small, and the reseal torque can be suppressed to be small on average.

  On the other hand, at the final stage of closure, the thread ridges 9a of the first and second tiers of the bottle can corresponding to the thread radii R1 and R2 and the valley bottom radii and the troughs of the cap 11 are screwed together. Therefore, it is possible to ensure the capping, so that the drinkable beverage does not leak out. In addition, in the state where the curled portion 10 is formed as described above, the thread radius R1 of the first stage thread 9a is larger than the thread radius R2 of the second stage thread 9a even when the cap 11 is attached. Therefore, when the curled portion 10 is formed, when the cap 11 is attached even in a thin bottle can, the first thread 9a has a larger diameter than the second thread 9a. There is no risk of protruding.

  Further, in the present embodiment, the thread radius R1 of the first-stage thread 9a is directed from the screw start part 9c of the predetermined height thread part 9d toward the twist direction of the male thread part 9 around the can axis C. Within a range L of at least 90 °, it is smaller than the thread radius R2 of the second stage thread 9a, so that the friction can be reliably suppressed and the reseal torque at the time of closing can be reduced. That is, if the thread radius R1 of the first-stage thread 9a is only smaller than the thread radius R2 of the second-stage thread 9a up to a range smaller than this range L, the second-stage thread 9a. Immediately, the second trough portion of the female screw portion 11c of the cap 11 comes into sliding contact with the cap 11, and there is a possibility that the reseal torque cannot be sufficiently reduced without suppressing the friction.

  Next, the effect of the present invention will be demonstrated with examples of the present invention. In this example, a bottle can with a cap in which a cap 11 is attached to the can body 1 of the bottle can according to the above embodiment is manufactured, and the cap 11 is opened once before the original position (opposite to the screwing direction). The average reseal torque when returned to 30 ° to the side) was measured. In this embodiment, the thread radius R1 from the can shaft C to the top of the first stage thread 9a in the thread part 9d of the predetermined height of the male thread part 9 is 18.4 mm, and the second stage thread 9a is The thread radius R2 to the apex is 18.5 mm, and the thread radius R1 of the first-stage thread 9a is the male thread portion 9 centering on the can axis C from the screw start portion 9c of the predetermined height thread portion 9d. In the range L of 90 ° toward the twist direction, the thread radius R2 of the second stage thread 9a was smaller.

  Further, as a comparative example for this embodiment, the thread radius of the first stage screw thread from the can shaft to the male thread part at a predetermined height is also equal to the thread radius R2 up to the top of the second stage thread. A bottle can with a cap of 18.5 mm was manufactured, and the average reseal torque was measured in the same manner. In these examples and comparative examples, the original plate thickness of the metal plate (aluminum alloy plate) cupping pressed on the cup-shaped material is 0.330 mm, and the bottomed cylindrical body formed from this cup-shaped material in the DI pressing process The thickness of the upper end portion of the cylindrical portion was 0.220 mm, and the thickness of the lower end portion was 0.130 mm.

  As a result, the average value of the reseal torque in the comparative example was 5.0 N · cm, whereas the average value of the reseal torque in the example was 0 N · cm. The feel that can be lightly plugged was obtained.

DESCRIPTION OF SYMBOLS 1 Can main body 9 Male thread part 9a Screw thread 9b Incomplete thread part 9c Screw start part 9d Predetermined height screw part 9e Multi-stage part 9f Screw trough 10 Curl part 11 Cap 11a Top plate part 11b Circumferential wall part 11c Female thread part C Can axis R1 Thread radius from can axis C to top of first stage thread 9a R2 Thread radius from can axis C to top of second stage thread 9a r1 First stage thread 9a from can axis C Thread root radius r2 from the bottom of the screw valley 9f adjacent to the lower end side of the screw thread r2 Thread root radius from the can shaft C to the bottom of the screw valley 9f adjacent to the lower end side of the second stage screw thread 9a L From the screw start portion 9c Range in which the first stage thread 9a having a small thread radius R1 is formed

Claims (3)

Provided on the upper end side of the neck part, the shoulder part diameter-reducing from the body part of the bottomed cylindrical can body centering on the can axis toward the upper end side, the neck part extending further from the shoulder part toward the upper end side A bottle can provided with a male screw part having a thread part with a predetermined height of one or more turns on the outer periphery, and a curl part formed by folding the upper end part of the can body to the outer peripheral side at the upper end side of the male screw part There,
In the cross-section along the can axis, the predetermined height screw portion in the male screw portion is the thread radius from the can axis to the top of the thread and the can of the thread valley adjacent to the lower end side of the thread. The difference between the screw root radius from the shaft to the bottom of the valley is 0.4 mm or more, and the predetermined height screw portion has a multi-stage having two or more threads in the cross section along the can shaft. Part is formed,
The thread radius from the can shaft to the top of the thread in the multi-stage part is the predetermined height as it goes toward the lower end side of the male thread part along at least the thread with the curled part formed. On the screw start portion side where the difference in the screw portion is within the above range, the thread radius of the first screw thread located closest to the curl portion is the lower end side of the can body of the first screw thread. A bottle can characterized in that it is smaller than the thread radius of the second-stage thread adjacent to.   The thread radius of the first stage thread is within a range of at least 90 ° from the screw start portion of the thread portion of the predetermined height toward the twist direction of the male thread portion around the can shaft. The bottle can according to claim 1, wherein the bottle can is smaller than the thread radius of the second stage thread. A bottled can with a cap attached with a bottomed cylindrical cap having a top plate part and a peripheral wall part from the curled part to the male thread part of the bottle can according to claim 1 or 2 There,
The cap has a female screw portion formed to follow the male screw portion of the bottle can on the inner periphery of the peripheral wall portion,
With the cap attached, the second stage screw adjacent to the lower end side of the can body of the first stage screw thread is the thread radius of the first stage thread located closest to the curl side. A bottle can with a cap characterized by being smaller than the thread radius of the mountain.

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