Tube container, mandrel, and method for manufacturing tube container

Abstract

The present invention provides a tube container in which the radius of curvature of the four corners of a sleeve is reduced and the fixing strength between the sleeve and a head is ensured, and furthermore in which deformation of the sleeve during molding is suppressed.　The tube container comprises: a flange part (21) in which a peripheral edge part (17a) is fixed to one end part (13a), the one end part (13a) extends in a straight line in an axial direction, and the peripheral edge part (17a) is fixed to an axial end face (13c) of the one end part (13a); and an outer peripheral part (22) fixed to an inner peripheral surface (13d) of the one end part (13a), wherein a head (14) comprises an annular protruding part (23) that protrudes downward from a base part (15), an outer peripheral surface (23a) of the protruding part (23) is fixed to the inner peripheral surface (13d) of the one end part (13a), and on the inner-surface side of four corner parts (25), a protruding part inner peripheral surface (23b), i.e., the inner peripheral surface of the protruding part (23), is an inclined surface that extends in a straight line so as to be positioned radially outward as the inclined surface proceeds downward.

Description

Tube container, mandrel, and method for manufacturing tube container

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

[0002] A tube container has been known in the past 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 the one end of the sleeve (see, for example, Patent Document 1). In the container of Patent Document 1, the 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.

[0003] Japanese Patent Application Laid-Open No. 2003-40293

[0004] A commonly known tube container has a sleeve with a rectangular shape, with four corners when viewed in the axial direction, where the portion of the sleeve connected to the head is connected to the head. For such tube containers, the curvature radius of the four corners may need to be reduced to improve appearance. However, if the curvature radius of the corners is reduced using the conventional structure in which a bent portion of the sleeve is fixed to the head, defects in the shape of the sleeve at the corners may occur during molding of the tube container. For example, the head material may bend to the outside of the sleeve or the sleeve may wrinkle at the bent portion. On the other hand, if the sleeve does not have a bent portion, it is difficult to ensure the bonding strength between the sleeve and the head. Furthermore, while four corners can be formed on the sleeve by inserting a mandrel with four corners for molding into the sleeve, the mandrel may get caught on the corners of the sleeve when inserting the mandrel into the sleeve, resulting in deformation of the sleeve. In particular, if the curvature radius 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.

[0006] The tube container comprises a cylindrical sleeve, a plate-shaped base, and a head having a mouth portion erected 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 in the axial direction of the sleeve from the head side, 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, which is 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.

[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.

[0010] Fig. 1 is a side view of a tube container according to a first embodiment of the present invention; Fig. 2 is a plan view of the tube container as seen from above; Fig. 3 is a cross-sectional view of the tube container; Fig. 4 is a diagram illustrating an example of a manufacturing method for a container body; Fig. 5 is a side view of a mandrel; Fig. 6 is a bottom view of the mandrel as seen from below; Fig. 7 is an enlarged cross-sectional view of a connection portion between a head and a sleeve in a second embodiment;

[0011] [First embodiment] 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 a first embodiment of the present invention. Fig. 2 is a plan view of the tube container 10 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 that stores 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 or food. The container body 11 includes a cylindrical sleeve 13 and a head 14 that is 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 formed continuously by extrusion molding or the like to 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) in the axial direction open. The opening at the 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 inner surfaces facing each other at the other end are abutted against each other.

[0014] 1 and 3 show the tube container 10 in an upright position, with the axis 13b of the sleeve 13 oriented vertically. The sleeve 13 is cylindrical when cut from the tube body, but when connected to the head 14 to form the container body 11, it forms the container barrel, which is the barrel of the container body 11. When viewed in the axial direction of the sleeve 13 from the head 14 side as shown in FIG. 2, the sleeve 13 is formed in a quadrangular shape with four curved corners 25 that conform to the shape of the head 14. 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 quadrangular, but the lower part of the sleeve 13 has a flattened shape that tapers toward the other end.

[0015] The head 14 includes a plate-like 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 that extends from one end 13a of the sleeve 13 radially inward of the sleeve 13, and a cylindrical upward extension 18 that extends radially inward and upward from the center of the shoulder 17. The head 14 is fixed to the one end 13a of the sleeve 13 via a radially outer peripheral edge 17a 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 peripheral engagement portion 16a with which the cap (not shown) engages is provided on the outer periphery of the mouth portion 16. The outer peripheral engagement portion 16a is a male threaded portion. The lower end of the mouth portion 16 is provided with a bottom plate portion 16b extending radially inward from the inner circumferential surface of the mouth portion 16, and a hole 16c penetrating the bottom plate portion 16b in the axial direction (up and down). Below the mouth portion 16, a stopper portion 18a is provided on the outer periphery of the upward extension portion 18 to restrict the rotational position of the cap threaded onto the outer peripheral engagement portion 16a to a predetermined position.

[0017] 1 and 3, the head 14 has a peripheral edge 17a of the shoulder 17 fixed to one end 13a of the sleeve 13. The one end 13a is a rectangular cylindrical portion that extends linearly in the axial direction of the sleeve 13. The one end 13a is the upper end of the 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 includes 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 circumferential surface 13d of the one end 13a below the flange 21. The head 14 also includes a protrusion 23 protruding downward from the lower surface 17b of the peripheral edge 17a of the shoulder 17. In FIG. 3, the lower surface 17b is illustrated 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 that protrudes radially outward from the outer circumferential portion 22 above the peripheral edge portion 17a. When viewed in the axial direction of the sleeve 13, the flange portion 21 has a rectangular shape that conforms to the one end portion 13a. The lower surface of the flange portion 21 is fixed to the end face 13c of the one end portion 13a by welding. The end face 13c is the upper end face of the one end portion 13a. The side and upper surfaces of the outer end of the flange portion 21 are chamfered into a curved shape by a chamfered portion 21a. The radius of curvature of the chamfered portion 21a is equal to or smaller than the thickness t2 of the one end portion 13a. Note that the corners of the flange portion 21 may be edges without providing the chamfered portion 21a. The portion of the upper surface of the shoulder portion 17 that is radially inward from 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 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 13a by welding.

[0022] As shown in FIG. 3 , in a cross-sectional view perpendicular to the axial direction of the sleeve 13, the protrusion inner peripheral surface 23b, which is the inner peripheral surface of the protrusion 23, extends obliquely in a straight line downward and radially outward from the lower surface 17b of the peripheral edge portion 17a and connects to the lower end of the outer peripheral surface 23a. That is, the 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 as it extends downward. In this embodiment, the protrusion inner peripheral surface 23b does not have an upwardly convex curve (a curve in which the protrusion inner peripheral 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 throughout the entire length (height) of the protrusion 23.

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

[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] 4 is a diagram illustrating an example of a manufacturing method of the container body 11. Fig. 4 illustrates a molding process, 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. Referring to Figs. 4, 5A, and 5B, the mandrel 30 has a block-shaped mandrel body portion 31 that is inserted into the sleeve 13, and a head forming portion 32 formed on the lower surface of the mandrel body portion 31.

[0028] A sleeve-forming portion 31a that fits into the inner circumference of the sleeve 13 is provided on the outer periphery of the lower part of the mandrel body 31. Furthermore, a relief portion 31b that is formed with a smaller diameter than the sleeve-forming portion 31a is provided on the outer periphery of the mandrel body 31 above the sleeve-forming portion 31a. As shown in FIG. 5B , when viewed in the axial direction of the sleeve 13, the sleeve-forming portion 31a has a rectangular shape that follows the inner periphery of the sleeve 13. The four corners of the rectangular shape of the sleeve-forming portion 31a are forming corners 31c that are used to form the four corners 25 of the sleeve 13. The forming 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 upper 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 shaped to fit along the protrusion inner peripheral surface 23b is provided on the outer periphery of the shoulder molding portion 32b. The protrusion molding portion 32c is a chamfered portion in which the outer peripheral edge of the lower surface of the mandrel body 31 is chamfered obliquely in a linear manner. 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 is tapered downward.

[0030] The mold 40 includes a first mold 41 having a base molding portion 41a shaped to fit the outer surface of the upward extension 18 and the outer surface of the shoulder 17, a second mold 42 having a shape corresponding to the outer periphery of the mouth 16, a third mold 43 having a shape corresponding to the tip of the mouth 16, and a fourth mold 44 having a shape corresponding to the inner periphery of the mouth 16. The first mold 41 has a cylindrical outer periphery guide portion 41b that receives the outer periphery of one end 13a of the sleeve 13. The outer periphery guide portion 41b extends linearly in the axial direction along the one end 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-out 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, molding the head 14 material in a cavity formed between the mandrel 30 and the mold 40 to form the head 14, and fixing the peripheral portion 17a and the protrusion 23 to one end 13a, as shown in Figure 4.

[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. This prevents the mandrel 30 from getting caught on the sleeve 13 when inserting the mandrel 30 into the sleeve 13, thereby preventing deformation of the sleeve 13 and allowing the mandrel 30 to be inserted smoothly into the sleeve 13.

[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 forming process, the portion of the sleeve 13 on the one end 13a side is sandwiched between the forming corners 31c and the first mold 41, thereby forming four corners 25. In this embodiment, the radius of curvature of the corners 25 is set to be relatively small, for example, 1.5 mm or less. If the radius of curvature of the corners 25 is small, the radius of curvature of the forming corners 31c also becomes small, making it easier for the forming corners 31c to get caught on the sleeve 13 when the mandrel 30 is inserted into the sleeve 13. In this embodiment, because the mandrel 30 includes the protrusion forming portion 32c, which is a linear chamfer, the mandrel 30 can be prevented from getting caught on the sleeve 13 even when the radius of curvature of the forming corners 31c is small.

[0035] In the molding process, the material for the head 14, softened by heating, is compressed between the mandrel 30 and the mold 40 as shown in Figure 4, thereby molding the head 14 and welding the head 14 to the one end 13a. During the molding process, the one end 13a of the sleeve 13 is radially supported 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 the material for the head 14 can be efficiently filled into the cavity that molds the flange portion 21.

[0036] If the radius of curvature of the corner 25 is small and the sleeve 13 is provided with a bent portion where the one end 13a bends radially inward, the deformation load of the sleeve 13 at this portion increases, making it more likely that defects will occur in the shape of the sleeve 13 at the corner 25 of the one end 13a. In this case, the material of the head 14 may wrap around to the outside of the sleeve 13 during the molding process. In this embodiment, the one end 13a is straight and does not bend radially inward, so the corner 25 of the one end 13a can be molded into the correct shape. This prevents the material of the head 14 from wrapping around to 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 a protrusion 23, and the protrusion 23 is fixed to the one end 13a, thereby increasing the area of ​​the fixed portion between the head 14 and the one end 13a. Furthermore, as shown in FIG. 3, the thickness t1 of the protrusion 23 is greater than the thickness t2 of the one end 13a, so that the temperature of the protrusion 23 is maintained to a certain extent when the temperature of the head 14 drops after molding. This allows the protrusion 23 to be well welded to the one end 13a. Furthermore, the length L1 of the protrusion 23 in the vertical direction is longer than the length L2 of the outer periphery 22, so the temperature of the protrusion 23 can be well maintained during welding.

[0039] As described above, according to the first 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 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 includes an annular protrusion 23 that protrudes downward from the base 15, and an outer peripheral surface 23a of the protrusion 23 is fixed to the inner peripheral surface 13d of the one end 13a below the outer peripheral portion 22, and an inner peripheral surface 23b of the protrusion 23 is an inclined surface that extends linearly on the inner side of the four corners 25 so as to be positioned radially outward as it extends downward. With this configuration, the head 14 is fixed to the axial end face 13c of the one end 13a of the sleeve 13 by the flange portion 21 of the peripheral edge 17a of the base 15, and is fixed to the inner peripheral surface 13d of the one end 13a of the sleeve 13 by the outer peripheral portion 22 of the peripheral edge 17a of the base 15 and the outer peripheral surface 23a of the protrusion 23. This allows the peripheral edge 17a of the head 14 to be fixed to the one end 13a of the sleeve 13 in 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 radially, reducing the radius 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. This prevents the material of the head 14 from wrapping around the outside of the sleeve 13 or wrinkles from forming on the sleeve 13 at the bent radial portions. This allows the radius of curvature of the four corners 25 of the sleeve 13 to be reduced. Furthermore, on the inner side of the four corners 25 of the sleeve 13, the shape of the mandrel 30 that forms the protrusion inner circumferential surface 23b has 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. Therefore, deformation of the sleeve 13 during molding can be prevented.

[0040] Furthermore, protrusion inner circumferential surface 23b is provided around the entire inner circumference of protrusion 23. With 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) similar to protrusion inner circumferential surface 23b all around. Therefore, mandrel 30 can be inserted into sleeve 13 via the inclined surface that is provided all around the mandrel 30, and the mandrel 30 can be prevented from getting caught on corners 25 of sleeve 13.

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

[0042] Furthermore, 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 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. The protrusion forming portion 32c is a linear chamfer that fits along the protrusion inner circumferential surface 23b. With this configuration, when inserting the mandrel 30 into the sleeve 13, the protrusion forming portion 32c, which is a linear chamfer, can be used as a guide to smoothly insert the mandrel 30 into the sleeve 13.

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

[0044] Although one embodiment of the present invention has been described above, it should be understood that the present invention is not limited to this specific embodiment. Unless otherwise specified 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 illustrative of the effects of the present invention and do not necessarily imply that the effects of the present invention are limited to these. In the above embodiment, the container body 11 is described as being manufactured by compression molding. However, the present invention is not limited to this. The container body 11 may also be manufactured by, for example, injection molding, in which molten resin from which the head 14 is made is injected into a cavity. Furthermore, in the above embodiment, the protrusion inner circumferential surface 23b is described as being provided around the entire inner circumferential surface of the protrusion 23. However, the present invention is not limited to this. For example, the protrusion inner circumferential surface 23b, which is a linear inclined surface, may be provided only on the inner surface of the four corners 25, with the remaining portions of the inner circumferential surface of the protrusion 23 being curved inclined surfaces. 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 suppressing the occurrence of wrinkles or folds at the one end 13a.

[0045] Second Embodiment A second embodiment to which the present invention is applied will now be described with reference to FIG.

[0046] FIG. 6 is an enlarged cross-sectional view of the connection portion between the head 214 and the sleeve 213 in the second embodiment.

[0047] The tube container 210 includes a container body 211 that stores the contents, and a cap 212 that is attached to the container body 211. The container body 211 includes a cylindrical sleeve 213 and a head 214 that is fixed to one end 213a of the sleeve 213 in the axial direction.

[0048] The sleeve 213 is a tube formed by cutting a tube body formed continuously by extrusion molding or the like to a predetermined length in the axial direction. The sleeve 213 is made of synthetic resin. The sleeve 213 alone has one end 213a and the other end (not shown) in the axial direction open. The opening at the one end 213a of the sleeve 213 is closed by fixing the head 214 to the one end 213a. The opening at the other end of the sleeve 213 is closed by fixing the other end by a method such as welding while the inner surfaces facing each other at the other end are abutted against each other. When viewed in the axial direction, the sleeve 213 has a shape that follows the outer shape of the head 214. The outer shape of the head 214 may be circular or rectangular when viewed in the axial direction. The shape of the sleeve 213 is flattened at the lower part of the sleeve 213 and tapers toward the other end. In FIG. 6, the tube container 210 is shown in an upright position in which the tube container 210 is upright so that the axis of the sleeve 213 (similar to the axis 13b in FIG. 3) is oriented in the vertical direction.

[0049] The head 214 includes a plate-like base 215 and a cylindrical mouth portion extending from the base 215. This mouth portion is not shown in FIG. 6 , but is formed similarly to the mouth portion 16 shown in FIGS. 1 and 3 . The head 214 is a component formed separately from the sleeve 213. The head 214 is made of synthetic resin. The base 215 includes a shoulder portion 217 extending radially inward from one end 213 a of the sleeve 213, and a cylindrical upward extension portion 218 extending radially inward and upward from the center of the shoulder portion 217. The head 214 is fixed to the one end 213 a of the sleeve 213 via a radially outer peripheral edge portion 217 a of the shoulder portion 217.

[0050] The mouth portion is erected upward from the upper end of the upward extension portion 218. This mouth portion is cylindrical and disposed coaxially with the sleeve 213, and is disposed on the axis of the sleeve 213. In addition, an outer peripheral engaging portion (see outer peripheral engaging portion 16a in FIG. 3) with which the cap 212 engages is provided on the outer periphery of the mouth portion. The outer peripheral engaging portion is a male thread portion. The lower end of the mouth portion is provided with a bottom plate portion (similar to bottom plate portion 16b in FIG. 3) extending radially inward from the inner circumferential surface of the mouth portion, and a hole (similar to hole 16c in FIG. 3) penetrating this bottom plate portion in the axial direction (up and down direction).

[0051] The mouth is fitted with a check valve (not shown) for preventing backflow of the contents, and a nozzle (not shown). The contents of the container body 211 pass through the mouth and are discharged from the opening at the tip (upper end) of the nozzle.

[0052] The cap 212 includes a cylindrical mounting portion that is mounted on the opening, a disk-shaped upper wall portion (not shown) that closes the nozzle opening from above, and a cylindrical peripheral wall portion 212c that surrounds the mounting portion. The mounting portion of the cap 212 extends downward from the center of the upper wall portion. The peripheral wall portion 212c extends downward from the peripheral edge of the upper wall portion. The mounting portion and peripheral wall portion are arranged coaxially with the sleeve 213. The cap 212 is attached to the opening by engaging an inner peripheral engaging portion, which is a female thread portion provided on the inner periphery of the mounting portion, with an outer peripheral engaging portion (see outer peripheral engaging portion 16a in FIG. 3).

[0053] The head 214 has a peripheral edge 217a of a shoulder 217 fixed to one end 213a of the sleeve 213. The one end 213a is a cylindrical portion that extends linearly in the axial direction of the sleeve 213. The one end 213a is the upper end of the sleeve 213.

[0054] The shoulder portion 217 extends obliquely radially inward and upward from the one end portion 213a. The peripheral edge portion 217a of the shoulder portion 217 includes a flange portion 221 fixed to an axial end face 213c of the one end portion 213a, and an outer peripheral portion 222 fixed to an inner peripheral surface 213d of the one end portion 213a below the flange portion 221. The head 214 also includes a protrusion 223 protruding downward from a lower surface 217b of the peripheral edge portion 217a of the shoulder portion 217. In FIG. 6, the lower surface 217b is shown by imaginary lines. The protrusion 223 is annular and disposed coaxially with the sleeve 213.

[0055] The flange portion 221 is an annular portion that protrudes radially outward from the outer circumferential portion 222 above the peripheral edge portion 217a. The lower surface of the flange portion 221 is fixed to the end face 213c of the one end portion 213a by welding. The end face 213c is the upper end face of the one end portion 213a. The side and upper surfaces of the outer end portion of the flange portion 221 are chamfered into a curved shape by a chamfered portion 221a. The radius of curvature of the chamfered portion 221a is equal to or smaller than the thickness t2 of the one end portion 213a. Note that the corners of the flange portion 221 may be edges without providing the chamfered portion 221a. The portion of the upper surface of the shoulder portion 217 that is radially inward from the chamfered portion 221a forms a flat plane portion 217c. The lower end of the outer circumferential surface of the flange portion 221 is flush with the outer circumferential surface of the one end portion 213a.

[0056] The outer circumferential portion 222 of the peripheral edge portion 217a extends linearly in the vertical direction along the inner circumferential surface 213d of the one end portion 213a. The outer circumferential portion 222 is a stepped portion where the peripheral edge portion 217a is recessed radially inward relative to the flange portion 221, and extends from the lower surface of the flange portion 221 to the lower end of the peripheral edge portion 217a. The outer circumferential portion 222 is fixed to the inner circumferential surface 213d of the one end portion 213a by welding.

[0057] The outer peripheral surface 223a of the protrusion 223 extends linearly in the vertical direction along the inner peripheral surface 213d of the one end 213a. The outer peripheral surface 223a and the outer peripheral portion 222 of the peripheral edge portion 217a have the same diameter, and the outer peripheral surface 223a is continuous with the outer peripheral portion 222. The outer peripheral surface 223a of the protrusion 223 is fixed to the inner peripheral surface 213d of the one end 213a by welding.

[0058] As shown in FIG. 6 , in a cross-sectional view perpendicular to the axial direction of the sleeve 213, the protrusion inner peripheral surface 223b, which is the inner peripheral surface of the protrusion 223, extends obliquely linearly downward and radially outward from the lower surface 217b of the peripheral edge 217a and connects to the lower end of the outer peripheral surface 223a. Therefore, the radial thickness t1 of the protrusion 223 decreases downward. In the second embodiment, the protrusion inner peripheral surface 223b extends obliquely linearly rather than in an upwardly convex curve, so that the thickness t1 of the protrusion 223 can be ensured to be large throughout the entire length (height) of the protrusion 223. Furthermore, the thickness t1 of the protrusion 223 is greater than the plate thickness t2 of the one end 213a.

[0059] In this way, the peripheral edge 217a of the shoulder 217 of the head 214 is fixed to the one end 213a that extends linearly in the axial direction of the sleeve 213, and the one end 213a is not bent toward the inside in the radial direction of the sleeve 213. This makes it possible to avoid the formation of a large curved surface at the connection (fixing portion) between the peripheral edge 217a of the head 214 and the one end 213a.

[0060] The outer diameter of the peripheral wall portion 212c of the cap 212 is approximately the same as the outer diameter of the sleeve 213, and the outer peripheral surface of the peripheral wall portion 212c is continuous with the outer peripheral surface of the sleeve 213, giving the tube container 210 a neat appearance. In detail, the radially outer portion of the peripheral wall portion 212c of the cap 212 forms an overlapping portion 212e that overlaps with the position of one end portion 213a of the sleeve 213 in the radial direction. Note that the overlapping portion 212e is the portion outside the imaginary line shown in the peripheral wall portion 212c in FIG. 6.

[0061] The lower end 212f of the peripheral wall 212c faces from above a flat portion 217c provided on the upper surface of the shoulder 217 of the base 215 outside the opening. In this way, when the peripheral wall 212c of the cap 212 has the overlapping portion 212e, the lower end 212f of the peripheral wall 212c faces the flat portion 217c of the shoulder 217, thereby reducing the vertical gap G between the lower end 212f and the shoulder 217. This increases the sense of unity between the peripheral wall 212c of the cap 212 and the sleeve 213, improving the appearance of the tube container 210.

[0062] The container body 211 is manufactured by compression molding using a mandrel inserted into the sleeve 213 and a mold corresponding to the shape of the outer surface of the shoulder portion 217 and the shape of the mouth of the head 214, as in Figure 4.

[0063] According to the second embodiment, a cap 212 is provided that includes an attachment portion that is attached to the mouth of a head 214 and a cylindrical peripheral wall portion 212c that surrounds the attachment portion, the peripheral wall portion 212c being provided so as to overlap the one end 213a in the radial direction, and a lower end 212f of the peripheral wall portion 212c facing from above a flat portion 217c that is provided on the upper surface of the base 215 outside the mouth. With this configuration, when the peripheral wall portion 212c of the cap 212 is provided so as to overlap the one end 213a in the radial direction, the lower end 212f of the peripheral wall portion 212c faces the flat portion 217c on the upper surface of the base 215, thereby making it possible to reduce the gap G between the lower end 212f of the peripheral wall portion 212c and the upper surface of the base 215. This improves the appearance of the tube container 210 and also prevents foreign matter from entering the cap 212 through the gap G between the lower end 212f of the peripheral wall portion 212c and the upper surface of the base portion 215.

[0064] 10, 210: Tube container 13, 213: Sleeve 13a, 213a: One end 13c, 213c: End face 13d, 213d: Inner peripheral surface 14, 214: Head 15, 215: Base 16: Mouth 17a, 217a: Peripheral edge 21, 221: Flange 22, 222: Outer peripheral portion 23, 223: Protruding portion 23a, 223a: Outer peripheral surface 23b, 223b: Inner peripheral surface of protruding portion 25: Corner 30: Mandrel 31c: Forming corner 32: Head forming portion 40: Mold t1: Thickness (thickness of protruding portion) t2: Plate thickness (plate thickness of one end portion) L1: Length (length of protruding portion) L2: Length (length of outer peripheral portion)

Claims

1. A tube container comprising a cylindrical sleeve, a plate-like 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, the sleeve being formed in a quadrangular shape with four corners when viewed from the head in the axial direction of the sleeve, wherein the one end extends 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 circumferential portion fixed to the inner circumferential surface of the one end, the head comprising an annular protrusion protruding downward from the base, the outer circumferential surface of the protrusion being fixed to the inner circumferential surface of the one end below the outer circumferential portion, and the inner circumferential surface of the protrusion, which is the inner circumferential surface of the protrusion, is an inclined surface that extends linearly so as to be positioned radially outward as it extends downward on the inner side of the four corners.

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. A tube container according to claim 1, wherein the head is fixed to the one end by welding, and when viewed in a cross section perpendicular to the axial direction of the sleeve, the thickness of the protruding portion is greater than the thickness of the one end, and the length of the protruding portion in the vertical direction is longer than the length of the outer periphery.

4. A mandrel used in the manufacture of the tube container described in claim 1, comprising a forming corner portion for forming the corner portion, a head forming portion shaped to fit the head, and a protrusion forming portion provided on the outer periphery of the head forming portion for forming the protrusion, wherein the protrusion forming portion is a linear chamfered portion that fits the inner periphery of the protrusion.

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

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