Tube container, mandrel, and method for manufacturing tube container

Abstract

To provide a tube container in which curvature radii of four corners of a sleeve are reduced and fixing strength between a sleeve and a head is ensured, and furthermore in which deformation of the sleeve during molding is prevented.SOLUTION: A tube container comprises: a flange part (21) in which a peripheral edge part (17a) is fastened to one end (13a), the one end (13a) linearly extends in an axial direction, and the peripheral edge part (17a) is fastened to an axial end surface (13c) of the one end (13a); and an outer periphery part (22) fastened to an inner peripheral surface (13d) of the one end (13a). A head (14) comprises an annular protruding part (23) that protrudes downward from a base part (15), and an outer peripheral surface (23a) of the protruding part (23) is fastened to the inner peripheral surface (13d) of the one end (13a). On the inner-surface side of four corner parts (25), a protruding part inner peripheral surface (23b), i.e., an inner peripheral surface of the protruding part (23), is an inclined surface that linearly extends so as to spread radially outward toward a downward direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a tube container, a mandrel, and a method for manufacturing a tube container. [Background technology]

[0002] Conventionally, a tube container has been known that includes a cylindrical sleeve and a head having a mouth that closes the opening at one end of the sleeve, with the peripheral edge of the head fixed to one end of the sleeve (see, for example, Patent Document 1). In the container of Patent Document 1, one end of the sleeve is formed as a bent portion in which the upper end of the sleeve is bent radially inward, and this bent portion is fixed to the peripheral edge of the head. This ensures a large bonding area between the one end of the sleeve and the peripheral edge of the head, resulting in high bonding strength. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-40293 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, tube containers are commonly known in which the portion of the sleeve connected to the head has a square shape with four corners when viewed in the axial direction. In such tube containers, it is sometimes desirable to reduce the radius of curvature of the four corners to improve appearance. However, if the radius of curvature of the corners is reduced using the conventional structure in which a bent portion provided on the sleeve is fixed to the head, defects in the shape of the sleeve at the corners are likely to occur during molding of the tube container, such as phenomena such as the head material wrapping around the outside of the sleeve or wrinkles occurring in the sleeve at the bent portion. On the other hand, if the sleeve does not have a bent portion, it is difficult to ensure the strength of the bond between the sleeve and the head. Furthermore, by inserting a mandrel having four corners for forming into a sleeve, the four corners can be formed on the sleeve. However, when inserting the mandrel into the sleeve, the mandrel may get caught on the corners of the sleeve, causing deformation of the sleeve. In particular, when the radius of curvature of the four corners of the mandrel is small, the mandrel is likely to get caught on the corners of the sleeve. For this reason, it is desirable to suppress deformation of the sleeve caused by the mandrel.

[0005] In view of these points, the present invention aims to provide a tube container in which the radius of curvature of the four corners of the sleeve is small, the strength of the bond between the sleeve and the head is ensured, and deformation of the sleeve during molding can be suppressed. [Means for solving the problem]

[0006] The tube container comprises a cylindrical sleeve, a plate-shaped base, and a head having a mouth extending from the base and closing the opening at one end of the sleeve, the peripheral edge of the base being fixed to the one end, and the sleeve being formed in a quadrangular shape having four corners when viewed from the head side in the axial direction of the sleeve, the one end extending linearly in the axial direction of the sleeve, the peripheral edge comprising a flange portion fixed to the axial end face of the one end and an outer peripheral portion fixed to the inner peripheral surface of the one end, the head comprising an annular protrusion protruding downward from the base, the outer peripheral surface of the protrusion being fixed to the inner peripheral surface of the one end below the outer peripheral portion, and on the inner surface side of the four corners, the inner peripheral surface of the protrusion is an inclined surface that extends linearly so as to be positioned radially outward as it extends downward.

[0007] The mandrel used in manufacturing the tube container comprises a forming corner portion that forms the corner portion, a head forming portion shaped to fit the head, and a protrusion forming portion that is provided on the outer periphery of the head forming portion and forms the protrusion, and the protrusion forming portion is a linear chamfered portion that fits along the inner surface of the protrusion.

[0008] A method for manufacturing a tube container using a mandrel includes an insertion step of inserting the mandrel into the sleeve through the protrusion forming portion, and a molding step of forming the corner portion using the molding corner portion, molding the head material in a cavity formed between a mold and the mandrel to form the head, and fixing the peripheral portion and the protrusion portion to the one end. [Effects of the Invention]

[0009] According to the present invention, in a tube container, the radius of curvature of the four corners of the sleeve can be reduced, the strength of the bond between the sleeve and the head can be ensured, and deformation of the sleeve during molding can be suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view of a tube container according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the tube container seen from above. [Figure 3] FIG. 2 is a cross-sectional view of a tube container. [Figure 4] 10A to 10C are diagrams illustrating an example of a method for manufacturing a container body. [Figure 5A] FIG. 2 is a side view of the mandrel. [Figure 5B] FIG. 2 is a bottom view of the mandrel. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a tube container according to the present invention will be described with reference to the drawings. Fig. 1 is a side view of a tube container 10 according to an embodiment of the present invention. Fig. 2 is a plan view of the tube container 10 as seen from above. Fig. 3 is a cross-sectional view of the tube container 10.

[0012] The tube container 10 includes a container body 11 for storing the contents, and a cap (not shown) that is attached to the container body 11. The contents of the tube container 10 are not particularly limited, but may be, for example, viscous substances such as cosmetics and food. The container body 11 includes a cylindrical sleeve 13 and a head 14 fixed to one end 13a of the sleeve 13 in the axial direction.

[0013] The sleeve 13 is a tube formed by cutting a tube body continuously formed by extrusion molding or the like into a predetermined length in the axial direction. The sleeve 13 is made of synthetic resin. The sleeve 13 alone has one end 13a and the other end (not shown) open in the axial direction. The opening at one end 13a of the sleeve 13 is closed by fixing the head 14 to the one end 13a. The opening at the other end of the sleeve 13 is closed by fixing the other end by a method such as welding while the opposing inner surfaces at the other end are brought into contact with each other.

[0014] 1 and 3, the tube container 10 is shown in an upright position in which the tube container 10 is upright so that the axis 13b of the sleeve 13 is oriented in the vertical direction. The sleeve 13 is cylindrical by itself after the tube body is cut, but when it is connected to the head 14 to form the container body 11, it forms the container body portion, which is the barrel portion of the container body 11. 2, the sleeve 13 is formed in a quadrangular shape having four curved corners 25 that conform to the shape of the head 14 when viewed in the axial direction of the sleeve 13 from the head 14 side. More specifically, the sleeve 13 is a rectangular cylinder when viewed in the axial direction. The axis 13b is located at the center of the quadrangular sleeve 13. When viewed in the axial direction from the head 14 side, the basic shape of the sleeve 13 is rectangular, but the lower part of the sleeve 13 has a flat shape that tapers toward the other end.

[0015] The head 14 includes a plate-shaped base 15 and a cylindrical mouth 16 that stands upright from the base 15. The head 14 is a component that is formed separately from the sleeve 13. The head 14 is made of synthetic resin. The base 15 includes a shoulder 17 extending radially inward from one end 13a of the sleeve 13, and a cylindrical upward extension 18 extending radially inward and upward from the center of the shoulder 17. The head 14 is fixed to one end 13 a of the sleeve 13 via a radially outer peripheral edge 17 a of the shoulder 17 .

[0016] The mouth portion 16 stands upright from the upper end of the upward extension portion 18. The mouth portion 16 is cylindrical and arranged coaxially with the axis 13b. The contents of the container body 11 are discharged from the mouth portion 16. The cap closes the mouth portion 16. An outer periphery engaging portion 16a that engages with the cap (not shown) is provided on the outer periphery of the mouth portion 16. The outer periphery engaging portion 16a is a male thread portion. The lower end of the mouth 16 is provided with a bottom plate 16b extending radially inward from the inner circumferential surface of the mouth 16, and a hole 16c penetrating the bottom plate 16b in the axial direction (vertical direction). A stopper portion 18a is provided on the outer periphery of the upward extension portion 18 below the mouth portion 16 to restrict the rotational position of the cap screwed onto the outer periphery engagement portion 16a to a predetermined position.

[0017] 1 and 3, the head 14 has a peripheral edge 17 a of a shoulder 17 fixed to one end 13 a of the sleeve 13 . One end 13a is a rectangular cylindrical portion that extends linearly in the axial direction of sleeve 13. One end 13a is the upper end of sleeve 13.

[0018] The shoulder 17 extends obliquely radially inward and upward from the one end 13a. The peripheral edge 17a of the shoulder 17 has a flange 21 fixed to the axial end face 13c of the one end 13a, and an outer peripheral portion 22 fixed to the inner peripheral surface 13d of the one end 13a below the flange 21. The head 14 also has a protrusion 23 that protrudes downward from the lower surface 17b of the peripheral edge 17a of the shoulder 17. In Fig. 3, the lower surface 17b is shown by imaginary lines. The protrusion 23 is provided along the entire circumference of the inner circumferential surface 13d of the one end 13a, and has a rectangular ring shape when viewed in the axial direction of the sleeve 13.

[0019] The flange portion 21 is an annular portion located above the peripheral edge portion 17a and protruding radially outward relative to the outer periphery portion 22. When viewed in the axial direction of the sleeve 13, the flange portion 21 has a rectangular shape that follows the one end portion 13a. The lower surface of the flange portion 21 is fixed to the end surface 13c of the one end portion 13a by welding. The end surface 13c is the upper end surface of the one end portion 13a. The side and top surfaces of the outer end of flange 21 are chamfered into a curved shape by chamfered portions 21a. The radius of curvature of chamfered portions 21a is equal to or smaller than the thickness t2 of one end 13a. Note that the corners of flange 21 may be edges without providing chamfered portions 21a. The portion of the upper surface of the shoulder portion 17 that is radially inward of the chamfered portion 21a forms a flat plane portion 17c. The lower end of the outer circumferential surface of the flange portion 21 is flush with the outer circumferential surface of the one end portion 13a.

[0020] The outer circumferential portion 22 of the peripheral edge portion 17a extends linearly in the vertical direction along the inner circumferential surface 13d of the one end portion 13a. The outer circumferential portion 22 is a stepped portion of the peripheral edge portion 17a recessed radially inward relative to the flange portion 21, and extends from the lower surface of the flange portion 21 to the lower end of the peripheral edge portion 17a. When viewed in the axial direction of the sleeve 13, the outer circumferential portion 22 has a rectangular shape that follows the one end portion 13a. The outer circumferential portion 22 is fixed to the inner circumferential surface 13d of the one end portion 13a by welding.

[0021] The outer peripheral surface 23a of the protrusion 23 extends linearly in the vertical direction along the inner peripheral surface 13d of the one end portion 13a. The outer peripheral surface 23a and the outer peripheral portion 22 of the peripheral edge portion 17a have the same diameter, and the outer peripheral surface 23a is continuous with the outer peripheral portion 22. The outer peripheral surface 23a of the protrusion 23 is fixed to the inner peripheral surface 13d of the one end portion 13a by welding.

[0022] 3, in a cross-sectional view perpendicular to the axial direction of sleeve 13, protrusion inner peripheral surface 23b, which is the inner peripheral surface of protrusion 23, extends obliquely in a straight line downward and radially outward from lower surface 17b of peripheral edge 17a and is connected to the lower end of outer peripheral surface 23a. In other words, protrusion inner peripheral surface 23b is an inclined surface that extends in a straight line so as to be positioned radially outward as it extends downward. Therefore, the radial thickness t1 of the protrusion 23 decreases downward. In this embodiment, the protrusion inner circumferential surface 23b does not have an upwardly convex curve (a curve in which the protrusion inner circumferential surface 23b in FIG. 3 is recessed toward the flange portion 21), but extends obliquely in a straight line, so that the thickness t1 can be ensured to be large over the entire length (height) of the protrusion 23.

[0023] The thickness t1 of the protruding portion 23 is greater than the thickness t2 of the one end portion 13a. In the vertical direction, the length L1 of the protrusion 23 is longer than the length L2 of the outer periphery 22 of the peripheral edge 17a. Furthermore, the length L2 of the outer circumferential portion 22 is longer than the length L3 of the flange portion 21 in the vertical direction.

[0024] In this way, the peripheral edge 17a of the shoulder 17 of the head 14 is fixed to the one end 13a that extends linearly in the axial direction of the sleeve 13, and the one end 13a is not bent toward the inside in the radial direction of the sleeve 13. This makes it possible to avoid the formation of a large curved surface at the connection (fixing portion) between the peripheral edge 17a of the head 14 and the one end 13a.

[0025] Furthermore, the flange portion 21 of the head 14 is fixed to the axial end face 13c of the one end 13a, and the outer peripheral portion 22 and the outer peripheral surface 23a of the protruding portion 23 are fixed to the inner peripheral surface 13d of the one end 13a. This allows the head 14 to be fixed to the one end 13a in the axial and radial directions, and also ensures a large area for the fixed portion. Therefore, even if the one end 13a is linear, the head 14 can be firmly fixed to the sleeve 13.

[0026] Fig. 4 is a diagram illustrating an example of a method for manufacturing the container body 11. Fig. 4 illustrates a molding step, which will be described later. The container body 11 is manufactured by compression molding using a mandrel 30 and a mold 40 .

[0027] Fig. 5A is a side view of the mandrel 30. Fig. 5B is a bottom view of the mandrel 30 as seen from below. 4, 5A and 5B, the mandrel 30 has a block-shaped mandrel body 31 that is inserted into the sleeve 13, and a head forming portion 32 that is formed on the lower surface of the mandrel body 31.

[0028] A sleeve forming portion 31a that fits onto the inner periphery of the sleeve 13 is provided on the outer periphery of the lower part of the mandrel body 31. Also, above the sleeve forming portion 31a on the outer periphery of the mandrel body 31, a relief portion 31b that is formed with a smaller diameter than the sleeve forming portion 31a is provided. 5B, when viewed in the axial direction of the sleeve 13, the sleeve molding portion 31a has a rectangular shape that follows the inner circumferential shape of the sleeve 13. The four corners of the rectangular shape of the sleeve molding portion 31a are molding corners 31c for molding the four corners 25 of the sleeve 13. The molding corners 31c are formed into curved surfaces that follow the inner surfaces of the corners 25.

[0029] The head molding portion 32 includes a central molding portion 32a shaped to fit along the inner surfaces of the upward extension portion 18 and the bottom plate portion 16b, and a shoulder molding portion 32b shaped to fit along the inner surface of the shoulder portion 17. A protrusion molding portion 32c having a shape that fits along the protrusion inner peripheral surface 23b is provided on the outer periphery of the shoulder molding portion 32b. The protrusion forming portion 32c is a chamfered portion obtained by linearly and obliquely chamfering the outer peripheral edge of the lower surface of the mandrel body 31. The chamfering angle θ of this chamfered portion is, for example, 40° with respect to a line parallel to the axis 13b. The protrusion molding portion 32c is provided around the entire outer periphery of the shoulder molding portion 32b. By providing the protrusion molding portion 32c, which is an inclined surface, the outer periphery of the shoulder molding portion 32b has a tapered shape that narrows downward.

[0030] The mold 40 comprises a first mold 41 having a base molding portion 41a shaped to conform to the outer surface of the upward extension portion 18 and the outer surface of the shoulder portion 17, a second mold 42 having a shape corresponding to the outer periphery of the mouth portion 16, a third mold 43 having a shape corresponding to the tip of the mouth portion 16, and a fourth mold 44 having a shape corresponding to the inner periphery of the mouth portion 16. The first mold 41 has a cylindrical outer periphery guide portion 41b that receives the outer periphery of one end portion 13a of the sleeve 13. The outer periphery guide portion 41b extends linearly in the axial direction along the one end portion 13a.

[0031] The manufacturing method of the container body 11 includes an insertion step of inserting the mandrel 30 into the sleeve 13, a material fitting step of fitting the punched head 14 material into the sleeve 13 after the insertion step, and a molding step of lowering the mandrel 30 within the sleeve 13 to form the corner 25 with the molding corner 31c, as shown in Figure 4, and molding the head 14 material in the cavity formed between the mandrel 30 and the mold 40 to form the head 14, and also fixing the peripheral portion 17a and the protrusion 23 to one end 13a.

[0032] In the above insertion step, the mandrel 30 is inserted into the sleeve 13 by inserting the head forming portion 32 from the opening at the upper end (other end) of the sleeve 13 (not shown in Figure 4). At this time, the mandrel 30 can be inserted into the sleeve 13 by making the protrusion forming portion 32c, which is a linear chamfered portion, contact the inner periphery of the opening at the upper end of the sleeve 13. Therefore, when the mandrel 30 is inserted into the sleeve 13, it is possible to prevent the mandrel 30 from getting caught on the sleeve 13, suppress deformation of the sleeve 13, and enable the mandrel 30 to be inserted into the sleeve 13 smoothly.

[0033] In the material fitting process, the material of the head 14 is heated and softened, and then punched out by a punch and fitted into the sleeve 13 .

[0034] In the molding process, the portion of the sleeve 13 on the side of the one end 13a is sandwiched between the molding corner portion 31c and the first mold 41, so that the four corner portions 25 are formed. In this embodiment, the radius of curvature of the corner 25 is set to be relatively small, for example, 1.5 mm or less. If the radius of curvature of corner 25 is small, the radius of curvature of forming corner 31c also becomes small, and when mandrel 30 is inserted into sleeve 13, forming corner 31c is more likely to get caught on sleeve 13. In this embodiment, mandrel 30 has protrusion forming portion 32c, which is a linear chamfered portion, so that even if the radius of curvature of forming corner 31c is small, mandrel 30 can be prevented from getting caught on sleeve 13.

[0035] In addition, in the molding process, the material of head 14 softened by heating is compressed between mandrel 30 and mold 40 as shown in Figure 4, thereby molding head 14 and welding head 14 to one end 13a. During the molding process, one end 13a of the sleeve 13 is radially received by the outer circumferential guide portion 41b of the first mold 41. The flange portion 21 is formed by the material for the head 14 that is filled into the cavity between the end face 13c of the one end 13a and the base molding portion 41a. During the molding process, the inclined protrusion molding portion 32c faces the cavity that molds the flange portion 21, so that the material for the head 14 can be filled well into the cavity that molds the flange portion 21.

[0036] If the radius of curvature of corner 25 is small and one end 13a is provided with a bent portion that bends radially inward, the deformation load of sleeve 13 at this portion increases, and defects in the shape of sleeve 13 are likely to occur at corner 25 of one end 13a. In this case, a phenomenon may occur in which the material of head 14 wraps around to the outside of sleeve 13 during the molding process. In this embodiment, the one end 13a is straight and not bent radially inward, so that the corner 25 of the one end 13a can be formed into the correct shape. This prevents the material of the head 14 from wrapping around the outside of the sleeve 13.

[0037] After the molding process, the container body 11 is removed from the mandrel 30 and the mold 40. The other end of the sleeve 13 is closed by welding or other means after the container body 11 is filled with the contents.

[0038] In the container body 11, the head 14 has the protrusion 23, and the protrusion 23 is fixed to the one end 13a, so that the area of the fixed portion between the head 14 and the one end 13a can be increased. 3, the thickness t1 of the protruding portion 23 is greater than the thickness t2 of the one end portion 13a, and therefore the temperature of the protruding portion 23 is maintained to a certain extent when the temperature of the head 14 drops after molding. This allows the protruding portion 23 to be well welded to the one end portion 13a. Furthermore, since the length L1 of the protruding portion 23 in the vertical direction is longer than the length L2 of the outer circumferential portion 22, the temperature of the protruding portion 23 can be maintained at a good level during welding.

[0039] As described above, according to an embodiment of the present invention, the tube container 10 includes a cylindrical sleeve 13, a plate-like base 15, and a head 14 having a mouth 16 extending upright from the base 15 and closing an opening at one end 13a of the sleeve 13. In the tube container 10, a peripheral edge 17a of the base 15 is fixed to the one end 13a, and the sleeve 13 is formed into a quadrangle having four corners 25 when viewed in the axial direction of the sleeve 13 from the head 14 side. The one end 13a extends linearly in the axial direction of the sleeve 13, and the peripheral edge 17a includes a flange portion 21 fixed to an axial end face 13c of the one end 13a and an outer peripheral portion 22 fixed to an inner circumferential surface 13d of the one end 13a. The head 14 has a ring-shaped protrusion 23 that protrudes downward from the base 15, and the outer surface 23a of the protrusion 23 is fixed to the inner surface 13d of one end 13a below the outer surface 22, and on the inner surface side of the four corners 25, the inner surface of the protrusion 23, which is the protrusion inner surface 23b, is an inclined surface that extends linearly so as to be positioned radially outward as it extends downward. According to this configuration, the head 14 is fixed to the axial end surface 13c of the one end 13a of the sleeve 13 by the flange portion 21 of the peripheral edge portion 17a of the base 15, and is fixed to the inner circumferential surface 13d of the one end 13a of the sleeve 13 by the outer circumferential portion 22 of the peripheral edge portion 17a of the base 15 and the outer circumferential surface 23a of the protrusion 23. This allows the peripheral edge portion 17a of the head 14 to be fixed to the one end 13a of the sleeve 13 in both the axial and radial directions of the sleeve 13, thereby increasing the bonding strength between the sleeve 13 and the head 14. Furthermore, because the one end 13a of the sleeve 13 extends linearly in the axial direction of the sleeve 13 and is not bent in the radial direction, reducing the radii of curvature of the four corners 25 at the one end 13a makes it less likely that defects in the shape of the sleeve 13 will occur. In other words, this prevents the material of the head 14 from wrapping around the outside of the sleeve 13 and prevents wrinkles from forming in the sleeve 13 at bent portions that bend in the radial direction. This allows the radius of curvature of the four corners 25 of the sleeve 13 to be small. Furthermore, on the inner surface side of the four corners 25 of the sleeve 13, the shape of the mandrel 30 that forms the protrusion inner circumferential surface 23b is an inclined surface (protrusion forming portion 32c) that extends linearly following the inclined surface of the protrusion inner circumferential surface 23b. Therefore, when inserting the mandrel 30 into the sleeve 13, the mandrel 30 can be inserted into the sleeve 13 via the inclined surface of the mandrel 30, and the mandrel 30 can be prevented from getting caught on the corners 25 of the sleeve 13. This allows deformation of the sleeve 13 to be suppressed when the sleeve 13 is formed.

[0040] The protrusion inner peripheral surface 23b is provided around the entire inner periphery of the protrusion 23. According to this configuration, protrusion inner circumferential surface 23b is provided around the entire inner circumference of protrusion 23, and therefore the shape of mandrel 30 that forms protrusion inner circumferential surface 23b has an inclined surface (protrusion forming portion 32c) around its entire circumference similar to protrusion inner circumferential surface 23b. Therefore, mandrel 30 can be inserted into sleeve 13 via the inclined surface that is provided around the entire circumference of mandrel 30, and it is possible to prevent mandrel 30 from getting caught on corners 25 of sleeve 13.

[0041] In addition, the head 14 is fixed to 13a by welding, and in a cross-sectional view perpendicular to the axial direction of the sleeve 13, the thickness t1 of the protrusion 23 is greater than the plate thickness t2 of one end 13a, and in the vertical direction, the length L1 of the protrusion 23 is longer than the length L2 of the outer circumferential portion 22. According to this configuration, the temperature of the protruding portion 23 can be maintained at a level suitable for welding, and the head 14 can be welded to the one end portion 13a in a satisfactory manner.

[0042] In addition, the mandrel 30 used in manufacturing the tube container 10 includes a forming corner portion 31c that forms the corner portion 25, a head forming portion 32 that is shaped to fit the head 14, and a protrusion forming portion 32c that is provided on the outer periphery of the head forming portion 32 and forms the protrusion 23, and the protrusion forming portion 32c is a linear chamfered portion that fits along the protrusion inner surface 23b. According to this configuration, when inserting the mandrel 30 into the sleeve 13, the protrusion forming portion 32c, which is a linear chamfered portion, can be used as a guide, allowing the mandrel 30 to be smoothly inserted into the sleeve 13.

[0043] Furthermore, the manufacturing method of the tube container 10 using the mandrel 30 includes an insertion step of inserting the mandrel 30 into the sleeve 13 via the protrusion forming portion 32c, and a molding step of forming the corner portion 25 using the molding corner portion 31c, molding the material of the head 14 in the cavity formed between the mold 40 and the mandrel 30 to form the head 14, and fixing the peripheral portion 17a and the protrusion 23 to one end 13a. According to this configuration, the mandrel 30 can be smoothly inserted into the sleeve 13 in the insertion step by utilizing the protrusion forming portion 32c, which is a chamfered portion for forming the protrusion 23 in the forming step.

[0044] Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and unless otherwise limited in the above description, various modifications and variations are possible within the spirit and scope of the present invention as defined in the claims. For example, the configurations of the above-described embodiment may be added or deleted as appropriate, and the configurations of one embodiment may be incorporated into other embodiments. Furthermore, the effects of the above-described embodiment are merely examples of the effects resulting from the present invention, and do not mean that the effects of the present invention are limited to the above-described effects. In the above embodiment, the container body 11 is described as being manufactured by compression molding, but the present invention is not limited to this, and the container body 11 may also be manufactured by injection molding, for example, in which molten resin that will become the material for the head 14 is injected into a cavity. In the above embodiment, protrusion inner peripheral surface 23b is described as being provided on the entire inner peripheral surface of protrusion 23, but the present invention is not limited to this. For example, protrusion inner peripheral surface 23b, which is a linear inclined surface, may be provided only on the inner surface of four corners 25, with the remaining part of the inner peripheral surface of protrusion 23 being a curved inclined surface. Alternatively, the sleeve 13 may have a laminate structure in which a metal sheet made of, for example, an aluminum-based material is laminated on a main body of the sleeve 13 made of synthetic resin. In this case, one end 13a of the sleeve 13 extends linearly, and the one end 13a having the laminate structure is not bent radially inward, thereby preventing wrinkles and creases from occurring at the one end 13a. [Explanation of symbols]

[0045] 10: Tube container 13: Sleeve 13a: One end 13c: End face 13d: Inner surface 14: Head 15: Base 16: Mouth 17a: Periphery 21: Flange part 22: Outer periphery 23:Protrusion 23a: Outer surface 23b: Inner peripheral surface of protrusion 25: Corner 30: Mandrel 31c: Corner for molding 32: Head molding part 40: Mold t1: Thickness (thickness of protrusion) t2: Plate thickness (plate thickness at one end) L1: Length (length of protrusion) L2: Length (length of outer periphery)

Claims

1. A tube container comprising a cylindrical sleeve, a head having a plate-like base and a mouth portion extending from the base and closing an opening at one end of the sleeve, wherein a peripheral edge of the base is fixed to the one end, and the sleeve is formed in a quadrangular shape having four corners when viewed from the head side in the axial direction of the sleeve, The one end portion extends linearly in the axial direction of the sleeve, the peripheral edge portion includes a flange portion fixed to an axial end surface of the one end portion, and an outer circumferential portion fixed to an inner circumferential surface of the one end portion, the head includes an annular projection projecting downward from the base; an outer circumferential surface of the protrusion is fixed to the inner circumferential surface of the one end portion below the outer circumferential portion; A tube container in which the inner peripheral surface of the protrusion, which is the inner peripheral surface of the protrusion, on the inner surface side of the four corners is an inclined surface that extends linearly so as to be positioned radially outward as it extends downward.

2. The tube container according to claim 1 , wherein the inner peripheral surface of the protrusion is provided around the entire inner periphery of the protrusion.

3. the head is fixed to the one end by welding; 2. The tube container according to claim 1, wherein, in a cross-sectional view perpendicular to the axial direction of the sleeve, the thickness of the protrusion is greater than the plate thickness of the one end, and the length of the protrusion in the vertical direction is longer than the length of the outer circumferential portion.

4. A mandrel used in manufacturing the tube container according to claim 1, a molding corner portion for molding the corner portion, a head molding portion having a shape that fits the head, and a protrusion molding portion provided on an outer periphery of the head molding portion for molding the protrusion, The protrusion forming portion is a mandrel that is a linear chamfered portion that follows the inner peripheral surface of the protrusion.

5. A method for manufacturing a tube container using the mandrel according to claim 4, an insertion step of inserting the mandrel into the sleeve through the protrusion forming portion; a molding step of forming the corner portion using the molding corner portion, forming the head by molding the head material in a cavity formed between the mold and the mandrel, and fixing the peripheral portion and the protrusion portion to the one end.

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