JP5402677B2 - Can with bead - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a can with a bead for stuffing beverages, foods, and the like, and particularly to a can with a bead suitable for improving strength characteristics required for a can such as axial compression strength, paneling strength, and rheometer strength.

  Cans with beads are widely used as small containers for stuffing food, beverages, and the like, and the thickness of the can body is being reduced from the viewpoint of reducing material costs and saving resources.

  However, since external force acts on cans with beads during manufacture, transportation, loading, etc., the thickness should be reduced after ensuring strength characteristics that do not damage the can against external forces. Is required. Possible causes of damage to the can include, for example, 1) buckling of the can body as a negative pressure can in which a pressure difference occurs between the inside and outside of the can due to expansion and contraction of the contents due to heat sterilization processing during the production of canned and beverage cans, 2) There are dents in the can body due to the support pressure on the side surface of the can body acting when the can is transported, etc., and 3) buckling with respect to the compression axial force in the can height direction due to the load applied when the cans are stacked.

  If deformation due to damage to the can body occurs, the value of the product as a canned or beverage can will be significantly reduced, so the can body has paneling strength against buckling of the negative pressure can and side support pressure. Rheometer strength, axial compressive strength in the can height direction, etc. are required. For this reason, from the viewpoint of improving the strength characteristics while reducing the thickness of the can body, a technique for forming an uneven bead in an annular shape so as to be adjacent to each other in the circumferential direction with respect to the can body is widely known.

  For example, in a can with a bead disclosed in Patent Document 1, a corrugated bead having a substantially triangular shape in cross section that gradually deepens as it shifts from the predetermined upper and lower end regions to the center of the can body in multiple stages in the circumferential direction of the can body Provided. The technology disclosed in Patent Document 1 intends to improve the vacuum resistance, that is, the paneling strength against negative pressure while suppressing the development length of the can body surface with respect to the height of the can after molding.

  In the three-piece can disclosed in Patent Document 2, an uneven bead having a waveform having a substantially triangular cross section is provided in the circumferential direction of the can body. In the disclosed technique of Patent Document 2, an uneven bead in the circumferential direction is formed within a range of 2 to 15% of the can height to improve the rheometer strength.

  In order to improve the paneling strength and rheometer strength in this way, it is necessary to increase the uneven height of the uneven beads to increase the bending resistance of the uneven beads in the circumferential direction. A problem arises that the uneven bead tends to collapse in an accordion shape against an external force in the height direction, and the axial compressive strength decreases. On the other hand, paying attention to this characteristic, as shown in Patent Documents 3 and 4, by securing the uneven height of the uneven bead having a substantially triangular cross section, the used empty can can be accordion-shaped from the can height direction. Also disclosed is a technique for easily crushing.

  FIG. 5 shows a side view of a conventional can 7 with a bead 7 provided with an uneven bead 72 having a substantially triangular cross section. This can 7 with a bead is formed in a cylindrical shape, and includes a can body 77 in which an annular uneven bead 72 is formed in the circumferential direction, and can lids 73 provided at the upper and lower ends of the can body 77. The can lid 73 is integrated with a winding 74. The can 7 with beads is formed of a thin metal plate such as steel. In the drawing, symbol D represents the diameter of the can, H represents the height of the can, and L represents the height of the installation range of the uneven beads 72.

  FIG. 6 shows an enlarged cross-sectional view of the concavo-convex bead 72 in the can 7 with a bead. The concave and convex beads 72 are alternately bent so as to have a substantially triangular cross section.

  When the bead-equipped can 7 provided with such an uneven bead 72 is subjected to a negative pressure, a pressure P1 acts from the outer surface toward the inner surface due to a pressure difference between the inside and the outside of the can as shown in FIG. FIG. 7A is a plan sectional view of the can body 77 provided with the uneven beads 72. The dotted line indicates the state before deformation, and the solid line indicates the state after deformation. Moreover, FIG.7 (b) has shown the side view of this can 7 with a bead in the state to which the pressure P1 acted. When the pressure P <b> 1 acts, the can body 77 is buckled and deformed so as to wave in the circumferential direction.

  The uneven bead 72 having a substantially triangular cross section is mainly resisted by the bending resistance I of the uneven bead 72 in the circumferential direction shown in FIG. Demonstrates a certain paneling strength. The bending resistance I can be improved by increasing the uneven height a of the uneven bead 72. On the other hand, when the concave / convex height a of the concave / convex bead 72 is increased, the compressive force pb on the can body surface shown in FIG. 8 (b), which is generated when the compression axial force P2 in the can height direction B shown in FIG. Since the amount of eccentricity (corresponding to the uneven height a) increases, the bending moment M generated at the inner edge and the outer edge of the uneven bead 72 increases, and the axial compressive strength P2 decreases.

  FIGS. 10A and 10B show a method for measuring the rheometer strength of the can. After setting the actual measuring can 101 to the measuring apparatus 110 provided with a tip bar for can barrel pressing (iron round bar having a length of 40 mm and a diameter of 10 mm) 111, a measuring jig (chip bar) Stress is applied to the can body 102 by moving 111 downward. FIG. 10C shows a state where the can body 102 is pressed by the tip bar 111. The rheometer strength due to the support pressure on the side surface of the can body 102 shown in FIG. 10 is resisted mainly by the bending resistance I of the uneven bead 72 in the circumferential direction, similar to the paneling strength. In order to improve the meter strength, it is necessary to increase the height of the unevenness, so that the axial compression strength is lowered. Furthermore, if the height of the uneven bead is large, the design of the can may be deteriorated.

  Moreover, as a cross-sectional shape of the annular concavo-convex bead provided in the circumferential direction of the can body, in addition to the substantially triangular cross section, Patent Document 5 discloses that the top and bottom surfaces of the convex portion among the concavo-convex beads formed on the can body. An example in which only a flat unprocessed body wall portion is provided is disclosed. However, this unprocessed body wall portion only leaves an unprocessed flat portion, and is not intentionally provided to improve the resistance characteristics against the external force of the beaded can. The purpose is to reduce the amount of spring pack generated in the trunk. At this time, since the concave portion has a substantially triangular shape and is not symmetrical with the convex portion, the neutral axis for bending in the circumferential direction of the uneven bead greatly deviates from the center position in the uneven height direction. There is a problem that it is difficult to ensure the bending resistance.

  As described above, in order to increase paneling strength, rheometer strength, and axial compression strength against external forces during manufacture, transportation, loading, etc. of a can with a bead, it exhibits properties that are contradictory to the unevenness height. Therefore, it is a problem to reliably increase both the bending resistance of the uneven bead and the axial compression resistance in the circumferential direction.

Japanese Utility Model Publication No. 56-32039 JP 2000-72143 A JP 2002-284159 A Japanese Patent Laid-Open No. 06-64651 Japanese Utility Model Publication No. 56-125828

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is to reduce the panel thickness of the can body and reduce the paneling strength against the buckling of the negative pressure can and the side support pressure. An object of the present invention is to provide a can with a bead provided with an uneven bead having a cross-sectional shape capable of improving strength characteristics required for a can such as a rheometer strength and an axial compressive strength in a can height direction.

In order to solve the above-mentioned problems, the present inventor has a cylindrical can body provided with an annular concave and convex bead in the circumferential direction, and a can lid provided with can lids provided at the upper and lower ends of the can body. In the uneven bead, the outer diameter portion and the inner diameter portion are alternately continued in the can height direction through the continuous portion, and the outer diameter portion and the inner diameter portion are respectively in the can height direction. A can with a bead was invented , which has a cross-sectional shape that is substantially parallel and substantially flat, and has the same width in the can height direction of the outer diameter portion and the inner diameter portion .

  The present invention relates to an annular concavo-convex bead provided in the circumferential direction of the can body of a can with a bead, and the outer diameter portion and the inner diameter portion are alternately continued in the can height direction through the continuous portion, and the outer diameter portion. The cross-sectional shape is such that the inner diameter portion is substantially flat and substantially parallel to the can height direction.

  Compared to the corrugated uneven bead having a substantially triangular cross section, which has a flat surface on the outer diameter portion and the inner diameter portion, by making the outer shape portion and the inner diameter portion have a substantially flat surface. The bending resistance of the concavo-convex beads with respect to the circumferential direction can be increased. Here, the bending resistance of the concavo-convex bead can be increased more efficiently by making the outer diameter portion and the inner diameter portion of the concavo-convex bead substantially the same in the can height direction. As a result, the paneling strength and rheometer strength can be improved even if the uneven bead height is kept small, and the uneven bead is bellows-shaped against the external force in the can height direction by suppressing the uneven height. It becomes difficult to be crushed and the axial compression strength can be improved.

  In this way, the paneling strength, rheometer strength, and axial compression strength can all be increased, ensuring the strength characteristics required for cans and reducing material costs and resource savings by reducing the thickness of the can body. It becomes possible to plan. Furthermore, the shape of the can body with the uneven bead height suppressed leads to improvement in the design of the can.

It is a side view of a can with a bead to which the present invention is applied. It is an expanded sectional view of the uneven bead in the present invention. It is another side view of the can with a bead to which the present invention is applied. It is a figure for demonstrating the effect of the can with a bead to which this invention is applied. It is a side view of the can with a bead provided with the uneven bead of the conventional cross-sectional substantially triangular shape. It is an expanded sectional view of the conventional uneven bead having a substantially triangular cross section. It is a figure for demonstrating the paneling intensity | strength with respect to the buckling of a negative pressure can. It is a figure for demonstrating the characteristic of the conventional uneven bead. It is a figure for demonstrating the axial compressive strength when a compressive axial force acts. It is a figure for demonstrating the measuring method of rheometer intensity | strength. It is a figure for demonstrating a FEM analysis result. It is a figure for demonstrating a FEM analysis result.

  Hereinafter, as an embodiment of the present invention, a can with a bead for stuffing a beverage or food will be described in detail.

  FIG. 1 is a side view of a can 1 with a bead to which the present invention is applied. This can 1 with a bead is formed in a cylindrical shape, a can body 2 in which an annular uneven bead 20 and a flat portion 30 without a bead are formed in a circumferential direction, and a can lid 3 provided at the upper and lower ends of the can body 2. , And the can body 2 and the can lid 3 are integrated by a winding 4. The ratio of the uneven bead 20 and the flat portion 30 in the can height direction may be adjusted according to the performance required for the can, and the flat portion 30 is omitted and the uneven bead 20 is directly connected to the can lid 3. You may do it. In addition, although the three-piece can which provided the can lid 3 in the upper and lower ends is illustrated in FIG. 1, the can bottom corresponding to the lower end can lid 3 is integrally formed with the can body, and the can lid 3 is formed only at the upper end. The provided two-piece can is also an object of the present invention. The material constituting the can with bead 1 may be steel (tinplate, tin-free steel, stainless steel, etc.), metal such as aluminum, resin, or other materials. In addition, the symbol D in a figure represents the diameter of the can, H represents can height, and L represents the height of the installation range of the uneven bead 20. The can height direction represents the direction of arrow A in the figure.

  FIG. 2 shows an enlarged cross-sectional view of the uneven bead 20 provided on the can body 2. The concave and convex bead 20 provided on the can body 2 having a plate thickness t has a can height through the continuous portion 23 so that the outer diameter portion 21 on the outer side of the can and the inner diameter portion 22 on the inner side of the can have a concave and convex height a. They are formed alternately in the vertical direction. The outer diameter portion 21 and the inner diameter portion 22 are respectively connected to the continuous portion 23 via the bent portion 24. The bending radius of the bent portion 24 can be appropriately set according to the material used. The width fo in the can height direction A of the outer diameter portion 21 and the width fi in the can height direction A of the inner diameter portion 22 include slightly bent portions 24 having curvatures at both ends, respectively. The inner diameter portion 22 is formed as a substantially flat surface substantially parallel to the can height direction. Further, if the projected length of the continuous portion 23 onto the can body surface is w, the crossing angle of the continuous portion 23 with respect to the outer diameter portion 21 and the inner diameter portion 22 is represented by θ (= atan (a / w)). . The continuous portion 23 does not necessarily have to be a flat surface, and the continuous portion 23 having an arcuate surface may be formed integrally with the bent portion 24. Further, it is desirable that the width fo of the outer diameter portion 21 in the can height direction A and the width fi of the inner diameter portion 22 of the can height direction A be substantially the same size.

  The embodiment of FIG. 3 is obtained by changing the ratio of the uneven bead 20 and the flat portion 30 in the can height direction A with respect to the example of FIG. This ratio is expressed as a ratio of the height L of the uneven bead 20 to the can height H. The embodiment of FIG. 3 assumes a case in which the strength performance of the can is enhanced by paying attention to the rheometer strength, but in this case as well, by applying the uneven bead 20 similar to FIG. Strength characteristics of cans with beads can be enhanced.

  In the present invention, as shown in FIG. 4, the bending resistance I of the uneven bead 20 shown in FIG. 4 (a) can be efficiently increased by providing the outer diameter portion 21 and the inner diameter portion 22 of a substantially flat surface. The paneling strength and the rheometer strength can be improved even if the uneven height a is suppressed. Accordingly, by suppressing the uneven height a while securing the paneling strength and the rheometer strength, the uneven bead 20 is not easily crushed into an accordion shape with respect to the external force in the can height direction A, and the axial compression strength is also improved. Is possible.

  Further, by making the width fo of the outer diameter portion 21 and the width fi of the inner diameter portion 22 substantially the same, the neutral axis for the bending of the uneven bead 20 in the circumferential direction coincides with the center position of the uneven height direction. The bending resistance of the uneven bead 20 can be increased efficiently. In addition, what is necessary is just to design suitably the other dimension of the shape of the uneven bead 20 according to the intensity | strength characteristic requested | required of the can 1 with a bead.

  Thus, by using the shape of the concavo-convex bead 20 of the present invention, the paneling strength, the rheometer strength, and the axial compression strength can all be increased, while satisfying the resistance characteristics against the external force required for the can, It is possible to reduce material costs and save resources by thinning the barrel. Furthermore, by suppressing the uneven bead height of the can body, the design of the can is improved.

  In order to explain the effects produced by the can with bead 1 to which the present invention is applied, the paneling strength P1 and axial compression of the can (No. 1A, 1B) having a can diameter of 153.8 mm × can height of 169.7 mm shown in Table 1 The rheometer strength of a can (No. 2A, 2B) having a strength P2 and a can diameter of 52.0 mm × can height of 104.0 mm shown in Table 2 was verified by FEM analysis, and a conventional substantially triangular uneven bead was provided. The yield strength of the can (No. 1A, 2A) and the can (No. 1B, 2B) provided with the uneven beads of the present invention were compared.

Each symbol in the table is: can diameter: D, can height: H, bead installation range height: L, plate thickness: t, uneven bead 20 height: a, uneven bead pitch: s, outer diameter portion 21 Width: fo, width of inner diameter part 22: fi, projected area of continuous part 23 onto can body surface: w, angle formed by continuous part 23 with respect to outer diameter part 21 and inner diameter part 22, θ, material yield point : Represents YP. In addition, since the comparative example (No. 1A, 2A) is a substantially triangular uneven bead without the outer diameter part 21 and the inner diameter part 22, the values of fo and fi in the table are zero. Assuming that steel is the component material of the can with bead, elasto-plastic large deformation analysis considering buckling behavior is performed using the finite element method program using Young's modulus: 205000 N / mm ² and Poisson's ratio: 0.3. The analysis results shown in FIGS. 11 to 12 were obtained.

  11A shows the analysis results regarding the paneling strengths of No. 1A and No. 1B, where the vertical axis in the figure represents the paneling load P1, and the horizontal axis in the figure represents the dent amount of the can body in the direction of the load P1. FIG. 11 (b) shows the analysis results regarding the axial compression strengths of No. 1A and No. 1B. The vertical axis in the figure indicates the axial compression load P2, and the horizontal axis in the figure indicates the amount of contraction in the can height direction in the direction of the load P2. Represent. 12 shows the analysis results regarding the rheometer strengths of No. 2A and No. 2B, the vertical axis of the figure represents the rheometer load P3, and the horizontal axis of the figure represents the amount of dent in the can body in the direction of the load P3. The maximum proof stress values (P1, P2, P3) and proof stress ratios (P1, P2, P3 ratios) determined from each figure are shown in Tables 1-2.

  From Table 1 and FIGS. 11 (a) to 11 (b), the can body with bead 1 to which the present invention is applied has a plate thickness of about 10% thinner than that of a conventional can with bead having a substantially triangular cross section. However, it was confirmed that equivalent paneling strength and axial compression strength could be secured.

  Also, from Table 2 and FIG. 12, the bead-equipped can 1 to which the present invention is applied has a rheometer strength of 1.4 times as long as the thickness of the same can body as compared with a conventional can-equipped bead having a substantially triangular cross section. It was confirmed that it can be improved. This result means that if the same rheometer strength is ensured, the can body can be made thinner.

  In addition, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations.

  Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

DESCRIPTION OF SYMBOLS 1 Can with bead 2 Can body 3 Can lid 4 Winding 20 Uneven bead 21 Outer diameter part 22 Inner diameter part 23 Continuous part 24 Bending part 30 Flat part

Claims (1)

In a can with a bead comprising a cylindrical can body provided with annular uneven beads in the circumferential direction, and can lids provided on the upper and lower ends of the can body,
The concavo-convex bead is formed such that an outer diameter portion and an inner diameter portion are alternately continued in a can height direction through a continuous portion,
The outer diameter and the inner diameter is substantially parallel respectively can height direction, and a substantially cross-sectional shape der which is flat is, the outer diameter and the inner diameter of the can height direction of the width A can with a bead characterized by substantially the same dimensions .

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