Lid body and packaging container

Abstract

To provide a lid body and a packaging container in which the deformation of protruding parts can be suppressed, and the production of the lid body can be facilitated.SOLUTION: A lid body 20 is fitted to a container body to compose a container 1. The lid body 20 comprises: a top plate part 21; and a side wall part 22. An end part 21a of the top plate part 21 is provided with at least two protruding parts 31 for regulating positional deviation between the container body and the lid body 20 when each container 1 is stacked and the container body is arranged on the lid body 20. Each protruding part 31 includes: a pedestal part 32; and a pair of convex parts 35 arranged on the pedestal part 32 at intervals. Each of the pair of convex part 35 extends along the end part 21a of the top plate part 21, and the pedestal part 32 includes an intermediate part 34 located between the pair of convex parts 35. In a direction intersecting with the end part 21a, the maximum width W1 of a top face 34a in the intermediate part 34 is wider than the maximum width W2 of each top face 35a in the pair of convex parts 35.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a lid and a packaging container. [Background technology]

[0002] Patent Document 1 describes a packaging container that includes a container body and a lid body that is attached to the container body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 54-104332 Summary of the Invention [Problem to be solved by the invention]

[0004] The packaging container as described above is used to package foods such as lunch boxes and side dishes. Such packaging containers may be stacked with food contained therein during transportation or display at a store. In order to prevent the position of the container body placed on the lid from shifting in this state, a projection for preventing shifting may be provided at the corner of the lid. However, for example, the projection may be deformed by an external force when attaching the lid to the container body or an external force when stacking the container body on the lid, and the function of preventing shifting may be impaired. In addition, if the projection is deformed and crushed, the commercial value decreases. The shape of the projection has been devised so that it can return to its original shape even if it is deformed, but even if such a shape is adopted, if it is greatly deformed or deformed many times, the deformed part may remain as a mark even if it is restored, and this mark may cause the projection to be damaged. In this way, it is required for the lid of the packaging container to suppress the deformation of the projection. In addition, it is also required for the packaging container to be easy to manufacture.

[0005] Therefore, an object of the present invention is to provide a lid and a packaging container that can suppress deformation of a protrusion and can facilitate the manufacture of the lid. [Means for solving the problem]

[0006] The lid of the present invention is, [1] "a lid which is attached to a container body to form a packaging container, the lid having a top plate and a side wall, the edge of the top plate having at least two protrusions for regulating misalignment between the container body and the lid when the packaging containers are stacked and the container body is placed on the lid, each of the protrusions having a base and a pair of convex portions spaced apart on the base, each of the pair of convex portions extending along the edge of the top plate, the base having an intermediate portion located between the pair of convex portions when viewed from a direction perpendicular to the top plate, the maximum width of the top surface of the intermediate portion being wider than the maximum width of the top surface of each of the pair of convex portions in a direction intersecting the edge."

[0007] In this lid, each protrusion has a base and a pair of convex parts arranged on the base at an interval. This configuration can suppress deformation (crushing) of the protrusion. In addition, in each protrusion, the maximum width of the top surface of the middle part located between the pair of convex parts on the base is wider than the maximum width of the top surface of each convex part. By making the width of the middle part of the base wider than the width of the convex part in this way, deformation of the protrusion can be further suppressed. Furthermore, when the width of the middle part is wider than the width of the convex part, the inclination of the side surface of the protrusion can be made gentler than when the width of the middle part is equal to or smaller than the width of the convex part. When the inclination of the side surface of the protrusion is gentle, the molding of the lid can be made easier than when the inclination is steep. Therefore, according to this lid, deformation of the protrusion can be suppressed and the manufacture of the lid can be made easier.

[0008] The lid of the present invention may be [2] "the lid according to [1], in which the top surface of the base is located between the top surface of the base and the top surface of the protrusion in a direction perpendicular to the top plate." In this case, the difference in height between the top surface of the protrusion and the top surface of the base can be reduced, and deformation of the protrusion can be further suppressed. In other words, if the difference is large, the boundary between the protrusion and the middle part of the base may become the starting point for deformation of the protrusion, but by reducing the difference, it is possible to prevent the boundary from becoming the starting point for deformation. Furthermore, the small difference makes it easier to mold the lid.

[0009] The lid of the present invention may be [3] "the lid according to [1] or [2], in which the length of the protrusion in the direction along the edge is 5 times or less the height of the top surface of the protrusion from the top plate portion." In this case, the length of the protrusion in the direction along the edge can be shortened, and the protrusion can be prevented from becoming a starting point of deformation.

[0010] The lid of the present invention may be [4] "the lid according to any one of [1] to [3], in which a step is formed by the base and the convex portion at an end of the protrusion in the direction along the edge." In this case, the strength of the end of the protrusion can be increased, and deformation of the protrusion can be further suppressed.

[0011] The lid of the present invention may be [5] "a lid according to any one of [1] to [4], in which the inner surface of the protrusion facing the center of the top plate includes a curved portion that is curved so as to be recessed toward the opposite side to the center of the top plate, and the curved portion is connected to the top plate." In this case, an external force acting on the protrusion can be suitably released to the top plate, and deformation of the protrusion can be further suppressed. In addition, when placing a container body on the lid, the container body can be guided by the curved portion, and the container body can be easily and accurately placed on the lid.

[0012] The packaging container of the present invention may be [6] "a lid according to any one of [1] to [5], in which the inner side surface facing the center of the top plate portion and the outer side surface facing the opposite side to the center of the top plate portion of the protrusion are sloped surfaces inclined with respect to a direction perpendicular to the top plate portion, and the slope of the inner side surface relative to the top plate portion is gentler than the slope of the outer side surface relative to the top plate portion." In this case, since the inner and outer sides of the protrusion are sloped surfaces, deformation of the protrusion can be further suppressed. In addition, when the container body is placed on the lid, the container body can be guided by the gently sloping inner side surface, and the container body can be easily and accurately placed on the lid.

[0013] The packaging container of the present invention may be [7] "a packaging container comprising the lid body according to any one of [1] to [6] and the container body to which the lid body is attached." According to this packaging container, for the reasons described above, it is possible to suppress deformation of the protrusions and facilitate the manufacture of the lid body. Effect of the Invention

[0014] According to the present invention, it is possible to provide a lid and a packaging container that can suppress deformation of a protrusion and can facilitate the manufacture of the lid. [Brief description of the drawings]

[0015] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view of the lid body as seen from below. [Diagram 3] FIG. 2 is a perspective view of the container body as seen from above. [Figure 4] FIG. 2 is a perspective view of the container body as seen from below. [Diagram 5] FIG. 4 is a perspective view of the protrusion as seen from the outside. [Figure 6] FIG. 4 is a perspective view of the protrusion as seen from the inside. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or corresponding elements are designated by the same reference numerals, and duplicated descriptions will be omitted. [Packaging containers]

[0017] As shown in Figures 1 to 4, container 1 (packaging container) comprises a container body 10 for containing contents, and a lid body 20 removably attached to container body 10. The contents contained (packaged) in container 1 are foods such as boxed lunches and side dishes. Container 1 is formed into a generally rectangular parallelepiped shape as a whole.

[0018] In the following description, the attachment direction of the lid body 20 to the container body 10 (the vertical direction in Figs. 1 to 4) is defined as the vertical direction, the side where the lid body 20 is located relative to the container body 10 when the lid body 20 is attached to the container body 10 (the upper side in Figs. 1 and 3) is defined as the upper side, and the side where the container body 10 is located relative to the lid body 20 (the lower side in Figs. 1 and 3) is defined as the lower side. In addition, when viewed from the vertical direction, the side of the center C of the top plate portion 21 described later is defined as the inside, and the side opposite to the center C is defined as the outside. Note that these directions do not limit the usage of the container 1. The container 1 is usually used in a state where the lid body 20 is located vertically above the container body 10, but is not limited to this usage.

[0019] Each of the container body 10 and the lid body 20 is manufactured, for example, by molding a synthetic resin sheet material into a predetermined shape using a predetermined mold.

[0020] The material of the container body 10 may be a non-foamed sheet material. The non-foamed sheet material may be polyethylene terephthalate, polystyrene, or polyolefin such as polypropylene or polyethylene. The non-foamed sheet material may be a sheet containing an inorganic component such as calcium carbonate, talc, or a filler to improve heat resistance. The non-foamed sheet material may be multi-layered or single-layered. A film may be attached to the non-foamed sheet material. The non-foamed sheet material may be transparent or may have various colors or patterns. Various additives may be added to produce the non-foamed sheet material.

[0021] The material of the container body 10 may be a foamed synthetic resin sheet material. The foamed synthetic resin sheet material may be polyethylene terephthalate, polystyrene, or polyolefin such as polypropylene or polyethylene. For example, a foamed polystyrene sheet obtained by foaming polystyrene, or a heat-resistant foamed polystyrene sheet obtained by foaming polystyrene with excellent heat resistance may be used.

[0022] The material of the lid 20 may be a transparent synthetic resin sheet material. The transparent synthetic resin sheet material may be polyethylene terephthalate, polystyrene, or polyolefin such as polypropylene or polyethylene. For example, a polystyrene sheet obtained by biaxially stretching polystyrene, or a heat-resistant biaxially stretched styrene-based resin sheet may be used. The material of the lid 20 may be a translucent or opaque synthetic resin sheet material. The non-transparent synthetic resin sheet material may be high impact polystyrene (HIPS) that contains a rubber component to increase impact resistance, or PP filler (filler-containing polypropylene).

[0023] Examples of methods for forming the container body 10 and the lid body 20 include vacuum forming, pressure forming, vacuum pressure forming, double-sided vacuum forming, and hot plate forming. The container body 10 and the lid body 20 can be manufactured by thermoforming a synthetic resin sheet by any of these methods. When a stretched sheet is used, hot plate forming may be employed in which the sheet is sandwiched between a heated hot plate and a mold to perform molding. [Container body]

[0024] As shown in FIG. 3 and FIG. 4, the container body 10 has a bottom plate portion 11, a side wall portion 12, a fitting portion 13, and a flange portion 14. The bottom plate portion 11 is formed in a substantially rectangular shape. A pair of protruding portions 15 protruding downward is formed on the bottom plate portion 11. The pair of protruding portions 15 are arranged so as to extend along a pair of short sides of the bottom plate portion 11, respectively, and face each other in the long side direction of the bottom plate portion 11. In this example, the protruding portion 15 is formed in a substantially rectangular shape having a long side along the short side of the bottom plate portion 11 in a plan view (when viewed from the top and bottom direction), and extends along substantially the entire short side of the bottom plate portion 11. The edges (both the inner surface side edge and the outer surface side edge) of the bottom surface 15a of the protruding portion 15 are curved at the corners, and the bottom surface 15a and the side surface 15b of the protruding portion 15 are smoothly connected (so that no sharp parts are formed between them) via the curved surfaces.

[0025] The side wall portion 12 is formed so as to surround the bottom plate portion 11 in a plan view, and is connected to the edge of the bottom plate portion 11 and extends upward from the edge. The side wall portion 12 extends at an incline with respect to the up-down direction so as to move outward as it moves upward. The fitting portion 13 is formed on the upper side of the side wall portion 12. In this example, the fitting portion 13 is a step portion (recess) formed around the entire circumference at the boundary portion between the side wall portion 12 and the flange portion 14. A fitting portion 23 of the lid body 20, which will be described later, is fitted into the fitting portion 13. The flange portion 14 extends outward from the fitting portion 13. The flange portion 14 is formed around the entire circumference and has a rectangular ring shape in a plan view. [Lid]

[0026] 1 and 2, the lid 20 has a top plate portion 21, a side wall portion 22, a fitting portion 23, and a flange portion 24. The top plate portion 21 is formed in a substantially rectangular shape corresponding to the bottom plate portion 11 of the container body 10. The top plate portion 21 is formed with four protrusions 31 that protrude upward. The protrusions 31 will be described in detail later.

[0027] The side wall portion 22 is formed so as to surround the top plate portion 21 in a plan view, and is connected to the edge portion 21a of the top plate portion 21 and extends downward from the edge portion 21a. The side wall portion 22 extends at an incline with respect to the up-down direction so as to extend outward as it approaches the lower side. The fitting portion 23 is formed on the lower side of the side wall portion 22. In this example, the fitting portion 23 is a convex portion formed around the entire circumference at the boundary portion between the side wall portion 22 and the flange portion 24, and protrudes downward with respect to the side wall portion 22 and the flange portion 24. The fitting portion 23 is fitted with the fitting portion 13 of the container body 10 described above. The flange portion 24 extends outward from the fitting portion 23. The flange portion 24 is formed around the entire circumference and has a rectangular ring shape in a plan view.

[0028] The fitting portion 23 of the lid body 20 is fitted into the fitting portion 13 of the container body 10, whereby the lid body 20 is attached to the container body 10, forming the container 1. In this attached state, the bottom plate portion 11 of the container body 10 and the top plate portion 21 of the lid body 20 face each other in the vertical direction, and the flange portion 14 of the container body 10 and the flange portion 24 of the lid body 20 face each other in the vertical direction. The flange portions 14, 24 may be in contact with each other in the attached state, or may face each other with a small gap therebetween. When removing the lid body 20, the engagement between the fitting portions 13, 23 is released by applying a force to the lid body 20 in a direction away from the container body 10, and the lid body 20 is removed from the container body 10.

[0029] In addition, the container 1 may be used by being stacked on top of another container 1. In this case, the container body 10 of another container 1 is placed on the lid body 20 of one container 1. At this time, the convex portion 15 formed on the bottom plate portion 11 of the container body 10 and the protrusion portion 31 formed on the top plate portion 21 of the lid body 20 regulate the positional deviation in the lateral direction (direction intersecting the vertical direction) between the container body 10 and the lid body 20. Specifically, for example, when the container body 10 arranged on the upper side tries to move in the lateral direction relative to the lid body 20 arranged on the lower side, the movement of the convex portion 15 of the container body 10 is regulated by the protrusion portion 31 of the lid body 20, so that the positional deviation between them is regulated. The details of the protrusion portion 31 will be described below. [Protrusion]

[0030] 1 and 2, the four protrusions 31 are formed on the edge 21a of the top plate portion 21. In this example, the four protrusions 31 are respectively arranged at the four corners 21b of the top plate portion 21. As particularly shown in FIGS. 5 and 6, each protrusion 31 has a base portion 32 and a pair of convex portions 35 arranged on the base portion 32 with a gap therebetween.

[0031] The base 32 extends along the edge 21a of the top plate 21. More specifically, the base 32 has a pair of extending portions 33 extending along a pair of sides constituting the corner 21b of the edge 21a, and an intermediate portion 34 located between the pair of extending portions 33. The above-mentioned protrusion 31 is formed on the extending portions 33, but is not formed on the intermediate portion 34. That is, the intermediate portion 34 is located between a pair of protruding portions 35 in a plan view (when viewed from a direction perpendicular to the top plate 21). In this example, the intermediate portion 34 extends in a curved manner along the corner 21b. Note that the base 32 is formed by molding a sheet material as described above, and the base 32 is not solid, and a space is formed inside the base 32.

[0032] Each protrusion 35 extends along the edge 21a of the top plate portion 21. In this example, the top surface 35a of the protrusion 35 is formed in a substantially trapezoidal shape having an inner edge as a first side 35a1 and an outer edge as a second side 35a2 that is parallel to the first side 35a1 and longer than the first side 35a1. The edge of the top surface 35a of the protrusion 35 is curved at the corners, and the top surface 35a and the side surface 35b of the protrusion 35 are smoothly connected (without forming a sharp portion between them) via the curved surface. In this example, the top surface 35a and the side surface 35b are smoothly connected at all corners, including the two corners located on the inside, among the four corners of the top surface 35a.

[0033] At both ends of the protrusion 31 in the direction along the edge 21a of the top plate 21, a step 36 is formed by the base 32 (extension 33) and the convex 35. That is, both ends of the protrusion 31 are formed in a staircase shape. The step 36 is formed by the extension 33 protruding outward from the convex 35 in the direction along the edge 21a.

[0034] In this example, the inner side surface 31a facing inward and the outer side surface 31b facing outward in the protrusion 31 are slope surfaces inclined with respect to the vertical direction (direction perpendicular to the top plate portion 21). That is, on both the inside and outside, the side surface of the base portion 32 and the side surface 35b of the protrusion 35 form a common slope surface. The inner side surface 31a is a curved surface that is curved so as to be recessed toward the outside. The outer side surface 31b is a slope surface that extends straight along a direction inclined with respect to the vertical direction. In this example, the outer side surface 31b forms a slope surface common to the side wall portion 22. In other words, the outer side surface of the lid body 20 is a slope surface that extends across the side wall portion 22 and the protrusion 31. No steps are formed on either the inner side surface 31a or the outer side surface 31b.

[0035] 8, the inclination of the inner side surface 31a with respect to the top plate portion 21 is gentler than the inclination of the outer side surface 31b with respect to the top plate portion 21. Note that the inclination here refers to the inclination angle when the surface extends straight like the outer side surface 31b, and when the surface is curved like the inner side surface 31a, it refers to the inclination angle when it is assumed that the surface extends straight without curving.

[0036] The dimensional relationship of each part will be described below. As shown in FIG. 5 and FIG. 6, the maximum width W1 of the top surface 34a of the middle part 34 of the base part 32 is wider than the maximum width W2 of the top surface 35a of the protruding part 35. The maximum widths W1 and W2 are widths in a direction intersecting (for example, perpendicular to) the edge part 21a of the top plate part 21. As an example, the maximum width W1 is about 8 mm, and the maximum width W2 is about 3 mm. Also, the maximum width W2 of the top surface 35a of the protruding part 35 is smaller than the minimum width of the top surface 34a of the middle part 34 (the minimum width of the base part 32). In this way, it is preferable that the maximum width W2 of the top surface 35a of the protruding part 35 is equal to or smaller than the minimum width of the top surface 34a of the middle part 34 (the minimum width of the base part 32). It should be noted that, as a different viewpoint from the above description, the protruding part 31 can also be considered to have a recess formed so as to separate a pair of protruding parts 35 from each other. In this case, the top surface 34a of the intermediate portion 34 corresponds to the bottom surface of the recess.

[0037] As shown in FIG. 7, the top surface of the base 32 (top surface 34a of the middle portion 34) is located between the top plate portion 21 and the top surface 35a of the protrusion 35 in the vertical direction. The length L1 (FIGS. 5 and 6) of the top surface 35a of the protrusion 35 in the direction along the edge portion 21a of the top plate portion 21 is 5 times or less than the height H1 (FIG. 7) of the top surface 35a of the protrusion 35 from the top plate portion 21. The length L1 may be 3 times or less than the height H1. As an example, the length L1 is about 8 mm, and the height H1 is about 3 mm. The maximum width W2 of the top surface 35a of the protrusion 35 described above is 1 / 3 times or more of the length L1 of the top surface 35a of the protrusion 35.

[0038] The length L2 (FIGS. 5 and 6) of the top surface 34a of the intermediate portion 34 in the direction along the edge portion 21a is more than twice the height H2 (FIG. 7) of the top surface 34a of the intermediate portion 34 from the top plate portion 21. As an example, the length L2 is about 7 mm, and the height H2 is about 1.5 mm. The height H1 of the top surface 35a of the convex portion 35 from the top plate portion 21 is less than five times the height H2 of the top surface 34a of the intermediate portion 34 from the top plate portion 21. In this example, the height H2 of the top surface 34a of the intermediate portion 34 from the top plate portion 21 is lower than the height of the top surface of the extension portion 33 from the top plate portion 21.

[0039] As described above, when the container body 10 of another container 1 is placed on the lid body 20, the projection 31 and the convex portion 15 of the container body 10 regulate the lateral positional deviation between the container body 10 and the lid body 20. More specifically, for example, the container body 10 is placed on the lid body 20 so that one end of the convex portion 15 contacts one of the projections 31 and the other end of the convex portion 15 contacts the other projection 31. At this time, the container body 10 is placed on the lid body 20 while the convex portion 15 is guided by the inner surface 31a of the projection 31. This allows the container body 10 to be easily and accurately positioned on the lid body 20. [Action and Effects]

[0040] In the lid 20, each protrusion 31 has a base 32 and a pair of convex portions 35 arranged on the base 32 at an interval. With this configuration, deformation (crushing) of the protrusion 31 can be suppressed. In addition, in each protrusion 31, the maximum width W1 of the top surface 34a of the intermediate portion 34 located between the pair of convex portions 35 in the base 32 is wider than the maximum width W2 of the top surface 35a of each convex portion 35. By making the width of the intermediate portion 34 of the base 32 wider than the width of the convex portion 35 in this manner, deformation of the protrusion 31 can be further suppressed. Furthermore, when the width of the intermediate portion 34 is wider than the width of the convex portion 35, the inclination of the side surface (inner surface 31a) of the protrusion 31 can be made gentler than when the width of the intermediate portion 34 is equal to or smaller than the width of the convex portion 35. When the inclination of the side surface of the protrusion 31 is gentle, the molding of the lid 20 can be facilitated compared to when the inclination is steep. Therefore, according to the lid body 20, deformation of the protrusion 31 can be suppressed, and the manufacture of the lid body 20 can be facilitated.

[0041] The easiness of forming the lid body 20 will be further explained. When forming the lid body 20, for example, a sheet material is brought into contact with a heated mold by vacuum suction to deform it. In this case, the portion of the sheet material corresponding to the flange portion 24 contacts the mold first, and the portions corresponding to the top plate portion 21 and the protrusion portion 31 contact the mold later. Therefore, forming the top plate portion 21 and the protrusion portion 31 is relatively difficult. In particular, if there is a portion with a large height difference, forming can be difficult. In this regard, in the lid body 20 of the embodiment, the maximum width W1 of the top surface 34a of the middle portion 34 is wider than the maximum width W2 of the top surface 35a of each convex portion 35, so that the inclination of the side surface of the protrusion portion 31 can be made gentle, and the forming of the lid body 20 can be made easier.

[0042] In the up-down direction (direction perpendicular to the top plate portion 21), the top surface 32a of the base portion 32 is located between the top plate portion 21 and the top surface 35a of the protrusion 35. This makes it possible to reduce the difference in height between the top surface 35a of the protrusion 35 and the top surface 32a of the base portion 32, and to further suppress deformation of the protrusion 31. In other words, if the difference is large, the boundary portion between the protrusion 35 and the intermediate portion 34 of the base portion 32 may become the starting point for deformation of the protrusion 31, but by reducing the difference, it is possible to suppress the boundary portion from becoming the starting point for deformation. Furthermore, the small difference makes it possible to facilitate the molding of the lid body 20.

[0043] The length L1 of the top surface 35a of the protrusion 35 in the direction along the edge 21a is 5 times or less the height H1 of the top surface 35a of the protrusion 35 from the top plate portion 21. This makes it possible to shorten the length L1 of the top surface 35a of the protrusion 35, and to prevent the protrusion 35 from becoming a starting point of deformation.

[0044] At the end of the protrusion 31 in the direction along the edge 21a, a step portion 36 is formed by the base portion 32 and the convex portion 35. This makes it possible to increase the strength of the end of the protrusion 31, and to further suppress deformation of the protrusion 31.

[0045] The inner surface 31a of the protrusion 31 facing inward (toward the center C of the top plate 21) is a curved surface that is curved so as to be recessed toward the outside (the opposite side to the center C of the top plate 21). This allows the external force acting on the protrusion 31 to be suitably released to the top plate 21, and deformation of the protrusion 31 can be further suppressed. In addition, when placing the container body 10 on the lid 20, the container body 10 can be guided by the inner surface 31a, and the container body 10 can be placed on the lid 20 easily and accurately.

[0046] The inner side surface 31a and the outer side surface 31b of the protrusion 31 form a sloped surface inclined relative to the top plate portion 21, and the slope of the inner side surface 31a relative to the top plate portion 21 is gentler than the slope of the outer side surface 31b relative to the top plate portion 21. As a result, the inner side surface 31a and the outer side surface 31b form sloped surfaces, which can further suppress deformation of the protrusion 31. In addition, when placing the container body 10 on the lid body 20, the container body 10 can be guided by the gently sloping inner side surface 31a, and the container body 10 can be placed on the lid body 20 easily and accurately.

[0047] At least two of the corners of the top surface 35a of the protrusion 35 that are located on the side of the center C of the top plate portion 21 have curved edges 21a of the top surface 35a. This makes it possible to further suppress deformation of the protrusion 31.

[0048] The length L2 of the top surface 34a of the intermediate portion 34 in the direction along the edge 21a of the top plate portion 21 is at least twice the height H2 of the top surface 34a of the intermediate portion 34 from the top plate portion 21. This makes it possible to increase the length L2 of the intermediate portion 34, and further suppress deformation of the protrusion 31.

[0049] The height H1 of the top surface 35a of the protrusion 35 from the top plate portion 21 is 5 times or less the height H2 of the top surface 34a of the intermediate portion 34 from the top plate portion 21. This allows the height of the protrusion 35 to be lowered, and deformation of the protrusion 31 can be further suppressed.

[0050] The maximum width W2 of the top surface 35a of the protrusion 35 is ⅓ or more of the length L1 of the top surface 35a of the protrusion 35 in the direction along the edge 21a. This makes it possible to increase the width of the top surface 35a of the protrusion 35, thereby further suppressing deformation of the protrusion 31.

[0051] The top surface 35a of the protrusion 35 is formed in a substantially trapezoidal shape having an inner edge (the side of the center C of the top plate 21) as a first side 35a1 and an outer edge (the side opposite the center C of the top plate 21) as a second side 35a2 that is parallel to the first side 35a1 and longer than the first side 35a1. This makes it possible to prevent the protrusion 35 from becoming a starting point of deformation, and to further suppress deformation of the protrusion 31.

[0052] The present invention is not limited to the above embodiment. For example, the material and shape of each component are not limited to the above-mentioned material and shape, and various materials and shapes can be adopted. The dimensional relationship of each part is not limited to the above-mentioned example. For example, the length L1 of the top surface 35a of the convex portion 35 may be greater than five times the height H1 of the top surface 35a of the convex portion 35. The inner side surface 31a of the protrusion portion 31 does not have to be a curved surface, and may extend straight, for example. The inclination of the inner side surface 31a with respect to the top plate portion 21 does not necessarily have to be gentler than the inclination of the outer side surface 31b with respect to the top plate portion 21, and may be equal to the inclination of the outer side surface 31b, for example. In the above embodiment, the entire inner side surface 31a is a curved surface, but the inner side surface 31a has a curved portion that is curved so as to be recessed toward the outside, and it is sufficient that the inner side surface 31a is connected to the top plate portion 21 at the curved portion, and only a part of the inner side surface 31a may be curved.

[0053] In the above embodiment, the protrusion 31 is formed at the corner 21b of the top plate portion 21, but the protrusion 31 may be formed at the edge 21a of the top plate portion 21, for example, at a side portion away from the corner 21b. In the above embodiment, the top plate portion 21 of the lid body 20 is formed in a rectangular shape, but the shape of the top plate portion 21 may be any shape such as a square shape, a polygonal shape other than a rectangle, a circle shape, an ellipse shape, an oval shape, etc. For example, the top plate portion 21 and the bottom plate portion 11 may be formed in a circular shape. In this case, the protrusion 31 is formed at the circular edge portion 21a of the top plate portion 21 and extends in an arc shape along the edge portion 21a. For example, four protrusions may be arranged at 90° intervals so as to be equally spaced in the circumferential direction. At least two protrusions 31 may be formed, for example, only two may be formed, or three or five or more may be formed.

[0054] In the above embodiment, the lid body 20 is attached to the container body 10 by fitting the fitting portion 23 of the lid body 20 with the fitting portion 13 of the container body 10, but any method of attachment between the lid body 20 and the container body 10 may be used, and the fitting portions 13, 23 may not be formed. The flange portions 14, 24 may be omitted. [Explanation of symbols]

[0055] 1...container (packaging container), 10...container body, 20...lid body, 21...top plate portion, 21a...edge portion, 22...side wall portion, 31...projection portion, 31a...inner surface, 31b...outer surface, 32...base portion, 32a...top surface, 34...middle portion, 34a...top surface, 35...convex portion, 35a...top surface, 36...step portion, C...center, W1, W2...maximum width, L1...length, H1...height.

Claims

1. A lid body that is attached to a container body to form a packaging container, A top plate portion and a side wall portion are provided. At least two protrusions are provided on an edge of the top plate for preventing misalignment between the container body and the lid when the packaging containers are stacked and the container body is placed on the lid, Each of the protrusions has a base portion and a pair of convex portions arranged at a distance from each other on the base portion, each of the pair of convex portions extends along the edge portion of the top plate portion, and the base portion has an intermediate portion located between the pair of convex portions when viewed from a direction perpendicular to the top plate portion, A lid body, wherein in a direction intersecting with the edge portion, the maximum width of the top surface of the middle portion is wider than the maximum width of each of the top surfaces of the pair of protrusions.

2. The lid according to claim 1 , wherein in a direction perpendicular to the top plate, a top surface of the base portion is located between the top plate portion and a top surface of the protrusion portion.

3. The lid according to claim 1 or 2, wherein a length of the protrusion in a direction along the edge is 5 times or less a height of the top surface of the protrusion from the top plate portion.

4. The lid according to claim 1 , wherein a step is formed at an end of the protrusion in a direction along the edge by the base and the convex portion.

5. The lid body described in claim 1 or 2, wherein the inner surface of the protrusion facing the center of the top plate portion includes a curved portion that is curved so as to be recessed toward the side opposite the center of the top plate portion, and is connected to the top plate portion at the curved portion.

6. In the protrusion, an inner surface facing the center of the top plate portion and an outer surface facing the opposite side to the center of the top plate portion each have a slope surface inclined with respect to a direction perpendicular to the top plate portion, The lid according to claim 1 or 2, wherein the inclination of the inner side surface relative to the top plate portion is gentler than the inclination of the outer side surface relative to the top plate portion.

7. A lid body according to claim 1 or 2, A packaging container comprising the container body to which the lid is attached.

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