JPH0331459Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a seaming chuck for a can seaming device that seams a can lid to a can body.

(Prior art) As is well known, the process of wrapping a can lid onto a can body is as follows:
The can body and can lid are pressed between the lifter plate and the seaming chuck and rotated together, and the primary seaming roll rapidly rotates around the can lid while applying pressure to the outer curled edge of the can lid. Then, wrap the outer curled edge under the opening outer flange edge of the can body,
Subsequently, the secondary seaming roll is backed up on the lip of the seaming chuck and compresses the outer periphery flange edge and outer periphery curled edge of the can body and can lid to form a seamed portion. If a slip occurs between the seaming chuck and the can lid during this seaming process, it will not be possible to obtain the appropriate seaming force, resulting in poor seaming and damage such as scratches on the can lid.
Furthermore, it wears out the seaming chuck.

Therefore, in order to prevent slippage between the seaming chuck and the can body, attempts have been made to roughen the bottom surface of the seaming chuck by shot peening, etc., to increase the frictional force between the seaming chuck and the can lid. (for example, Japanese Utility Model Application Publication No. 58-128733), and those in which the upper part of the outer peripheral surface of the seaming chuck is knurled to increase the friction with the chuck wall surface, and the upper part of the outer peripheral surface of the seaming chuck. It has been proposed that the lower part is knurled and the lower part is roughened (Japanese Utility Model Publication No. 77634/1983).

(Problem to be solved by the invention) In recent years, with the advent of can bodies made of materials with weak axial load resistance, such as thinner-walled aluminum and steel drawn and ironed cans, and PET laminated cans, Less pressure must be applied to the lifter and seaming chuck. On the other hand, high-hardness can bodies such as Teinfreel steel, that is, can materials with high seaming resistance, have been widely used. Moreover, there is a strong trend toward faster seaming operations, and the factors that cause slippage between the seaming chuck and the can lid have increased even more than in the past. As a result, the above-mentioned proposed means has the following problems and cannot be adequately addressed. In other words, conventional seaming chucks with a roughened lower part of the outer circumferential lip can be expected to have a certain effect on preventing slippage during the primary seaming process, but the surface roughness is 0.8 to 2S. Since the slip is small in size, slips are likely to occur during high-speed seaming, and once a slip occurs, the rough surface is lost and future slips cannot be effectively prevented. As a result, the outer circumferential surface of the seaming chuck portion is worn, shortening its life and requiring frequent replacement of the seaming chuck. In order to solve this problem, it is possible to make the surface roughness of the lip part rougher than the current one, but if the roughness is increased,
Once slippage occurs, there is a risk of leaving large scratch marks on the can lid, so there is a limit.

In addition, the upper part of the outer peripheral surface of the seaming chuck is knurled to increase the friction with the chuck wall surface, which is mainly intended to prevent slippage during the secondary seaming process, but it also increases the friction. In order for the knurling to work effectively, the knurling must be formed large, and the pitch of the conventional knurling is approximately 1.0 mm or more, the depth is approximately 0.26 mm, and the shoulder corner 16 of the knurling groove 15 is
had to be formed sharply as shown in FIG. Therefore, if the can is made of soft can lid material such as aluminum,
As shown in FIG. 7, large bite marks 19 are formed on the chuck wall 18 surface of the seam band, and when drinking the contents from a beverage can, the marks touch the lips and give a strange feeling. Further, there are also drawbacks such as peeling of the coating film and generation of scratches in the area. Furthermore, the upper part of the outer circumferential surface of the seaming chuck is knurled and the lower part is roughened.By having both of the above means, the seaming chuck has a knurling process on the upper part and a roughening process on the lower part. Although this method effectively prevents slippage in both cases, it does not overcome the technical drawbacks of both of the above methods, and it does not overcome the technical drawbacks of both methods, such as the occurrence of slippage at high speeds, unevenness on the can lid chuck wall surface, and scratches on the paint film. We are still not satisfied with the occurrence.

In addition, if the can lid slips, it not only damages the seaming chuck and the can as described above, but also causes the lifter plate surface to wear out, and as the number of seams increases, the lifter plate surface gradually becomes curved and depressed. is occurring.

The present invention was devised to eliminate the drawbacks of the conventional seaming chuck mentioned above, and does not leave large bite marks on the inner circumferential surface of the can lid due to the knurling, thereby preventing the occurrence of slippage. The purpose of the present invention is to provide a seaming chuck with low wear and long life that can effectively seam canned goods, prevent wear of the seaming chuck and lifter plate, and improve the efficiency of seaming work. .

(Means for solving the problems) The above-mentioned problems with conventional seaming chucks are (1) the groove shoulder angle of the knurling is sharp, (2) the pitch of the knurling and the depth of the groove are too small. (3) This is due to the small surface roughness of the seaming chuck clip, but these factors are
Conventionally, this has been regarded as a necessary technical means to increase the friction with the seaming chuck, and no other effective alternative has yet been found. However, as a result of various experiments, the inventor of the present invention found that, contrary to the conventional wisdom, by adopting the following measures, the knurling was made smaller, the angle of the shoulder of the knurling groove was blunted, and the roughness of the chuck clip portion was reduced. Even if the surface is roughened,
The present invention was developed based on the discovery that it is possible to improve the frictional force and seal the can lid well without damaging it.

That is, in the seaming chuck of the present invention, the upper part of the outer peripheral surface that fits into the inner peripheral surface of the can lid is knurled, and at least the shoulder corner of the knurled groove of the knurled part is roughened to form a knurled groove. The above problems were solved by blunting the corners of the shoulders and roughening the lower part of the outer peripheral surface.

Furthermore, the groove pitch of the knurling part is adjusted.
range from 0.1 to 1.0 mm, preferably from 0.3 to 0.7 mm,
In addition, the roughness of the rough surface applied to the lower part of the outer peripheral surface is 0.8 to 3S.
By setting the amount within this range, it is possible to more effectively prevent damage to the can lid and prevent slipping.

(Function) By making the groove shoulders of the knurling process rough by sandblasting, etc., the friction with the can lid increases dramatically due to the increase in friction due to the knurling process and the increase in friction due to the roughening process. increases.
Therefore, even if the groove pitch and depth of the knurled part are made smaller than before, sufficient friction with the can lid can be maintained, and there are no inconveniences such as the formation of large irregularities on the inner circumferential surface of the can lid as in the past. Does not occur. Furthermore, since the corners of the groove shoulders of the knurled portion are blunted by surface roughening, phenomena such as damage to the paint film on the can lid can be prevented. The present invention further increases the friction in this part by making the roughened part of the lip part rougher than before, and in conjunction with the above structure, even in high-speed seaming, the primary Also, the seaming chuck and can lid are effectively prevented from slipping during secondary seaming. As a result, there is less wear on the seaming chuck, and the life of the seaming chuck is long.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows cross sections of essential parts of various types of seaming chucks for can lids to which the present invention is applied, in which a is a straight type, b is a double angle type, and c is a step type. Figure 2 a, b
1 shows an embodiment of the seaming chuck of the present invention applied to a straight type. In the figure, 1 is the seaming chuck, 2 is the outer circumferential surface, 3 is the knurled part on the upper part of the outer circumferential surface, and 4 is the outer circumferential surface. This is the lip at the bottom. The knurling groove shoulder portion 5 and lip portion 4 of the knurled portion 3 have a roughness of 2.
~3S rough surface processing is applied.

Figures 3a to 3c show various cross-sectional shapes of the grooves 6 of the knurling. The knurling groove width w of the knurled part in the present invention is in the range of 0.1 to 0.5 mm, and the depth h is in the range of 0.1 to 0.05 mm, and the knurling is finer than that of the conventional knurling.
Note that the shape of the groove of the knurling is not limited to the shape shown in the figure, but may have an appropriate shape such as a trapezoidal shape in which the groove side walls are equally sloped or have asymmetrical side walls with a strong slope at the rear of the rotation of the seaming chuck. It is possible. Also,
When the seaming chuck is viewed from the side, the direction of the knurling is generally parallel to the axial direction of the seaming chuck as shown in Figure 2a, but as shown in Figure 2b. It may also be tilted as shown. The direction of this inclination is such that when the lid tries to rotate in the opposite direction relative to the direction of rotation of the seaming chuck, the screw action of this inclination causes the lid to incline in the direction in which it comes into close contact with the chuck. desirable.

FIG. 4 is an enlarged cross-sectional view of the knurled part, and by roughening the knurled groove shoulder, the knurled groove shoulder corner 7 is rounded and blunted to form a rough surface. The surface roughening may be performed uniformly over the entire knurled portion, but it must be applied at least to the corners of the groove shoulders.

The above seaming chuck is manufactured as follows. First, after forming the upper outer circumferential diameter to a size approximately 0.25 mm larger than the specified dimension (dimension A in Fig. 1), a predetermined knurling roughness is selected, and the knurls are formed at equal pitches in the C area of the upper outer circumference. Perform knurling processing. After that, it is hardened and polished to the dimension A in Figure 1. After that, B and C in FIG. 1 on the outer peripheral surface of the seaming chuck are
It is obtained by sandblasting, shot peening or liquid honing the area to obtain a rough surface with a roughness of 2 to 3S. Thereby, a seaming chuck with accurate external dimensions, uniform knurling shape and uniform surface roughness can be obtained.

As above, the knurling pitch is 0.3mm,
A seaming chuck is obtained in which knurling is performed to have a knurled groove width of 0.1 mm and a knurled groove depth of 0.2 mm, and the shoulder of the knurled groove and the outer periphery of the lip are roughened to a surface roughness of 3S. A 206P aluminum lid was tightened to the aluminum drawn and ironed can body using a mincing chuck, and the occurrence of slippage and damage such as peeling of the paint on the can lid were observed. As a result, even after sealing 10 million cans, no cans with scratch marks or peeling of the paint on the inner circumferential surface of the can lid were found, and all the cans were in good sealing condition, with no slippage during sealing. It was confirmed that this did not occur. In addition, the seam band portion 10 is shaped like A as shown in FIG.
- The sample was cut from side A, and the knurling marks generated on the inner circumferential surface of the can lid were observed using a microscope. The results are shown in FIG. 6, which is a reproduction of a microscopic photograph taken of the above-mentioned cut surface. As is clear from the figure, the chuck wall 11 of the seam band portion 10, that is, the knurling marks 12 formed on the inner peripheral surface of the can lid, has a maximum depth of 0.02 mm as shown in the figure, which is different from the conventional seaming chuck. The amount was almost negligible compared to the case of seaming. Furthermore, almost no wear on the lifter plate surface was observed.

(Effects) With the above configuration, the present invention provides the following special effects.

(b) By making the groove shoulders of the knurling process rough, the friction caused by the knurling process can be increased,
The increase in friction due to the rough surface processing works together to dramatically increase the friction with the can lid, and even if flexible cans or hard cans are seamed at high speed, there will be no slippage during both the primary and secondary seaming. There is no occurrence of this, and the can lid can be tightly sealed without damaging it. Furthermore, the seaming chuck has almost no wear and tear, dramatically increasing its lifespan, and the lifter plate has no wear at all. As a result, tool management for maintenance, inspection and maintenance in the seaming process, productivity work management, etc. have been greatly simplified, and stable, high-speed mass production of high-quality products has become possible.

(b) In addition, even if the groove pitch and depth of the knurling part are made smaller than before, sufficient friction with the can lid can be maintained, so large irregularities can be formed on the inner circumferential surface of the can lid, unlike conventional methods. No other inconveniences will occur.

[Brief explanation of the drawing]

Figures 1a, b, and c are front sectional views of essential parts of various types of seaming chucks to which the present invention is applied;
Figures 2a and b are front views of the seaming chuck according to the embodiment of the present invention, Figures 3a, b, and c are enlarged sectional views of various knurling grooves, and Figure 4 is a view of the knurling grooves in Figure 2. 5 is a front sectional view of the main part of the seaming part of a can seamed with the seaming chuck of the embodiment of the present invention; FIG. 6 is an enlarged view of the cross section taken along line A-A in FIG. FIG. 7 is a view corresponding to FIG. 6 of a can seamed with a conventional seaming chuck, and FIG. 8 is an enlarged cross-sectional plan view of the knurling groove of the conventional seaming chuck. 1... seaming chuck, 2... outer peripheral surface, 3
...Knurling part, 4...Rip part, 5...
Knurled groove shoulder, 6...Knurled groove, 7...
Knurled groove shoulder corner.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a seaming chuck of a can seaming device that seams a can lid to a can body, the upper part of the outer circumferential surface that fits into the inner peripheral surface of the can lid is knurled; A seam for a can seaming device, characterized in that at least the shoulder corners of the knurled grooves of the processed portion are roughened to blunt the corners of the knurled groove shoulders, and the lower portion of the outer peripheral surface is further roughened. Mingchatsk. 2 The groove pitch of the knurling part is 0.1 to 1.0.
2. The seaming chuck according to claim 1, wherein the seaming chuck has a roughness of 0.8 to 3S.