Packaging containers

Abstract

To provide a packaging container capable of preventing both crushing and damage to the side surface of a lid and cracking and damage to the top surface of the lid when the lid is closed even when a thin sheet is used.SOLUTION: A body side surface part 11 is provided with a body prop rib 17 that protrudes inward and extends along a vertical direction, a lid side surface part 31 is provided with a lid prop rib 40 that is provided at a circumferential direction corresponding to the body prop rib 17, protrudes outward, and extends in a vertical direction, when the lid is closed, the lid prop rib 40 and the body prop rib 17 are aligned vertically to form a prop column, and when viewed from above in the closed state, the lower end part of the lid prop rib 40 is spaced inward from the upper end part of the body prop rib 17.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a packaging container suitable for containing food. [Background technology]

[0002] When closing the lid, attaching a label to the top surface of the lid when the lid is closed, or stacking multiple packaging containers containing food, a large force is applied to the top surface of the lid. To withstand this force, ribs are sometimes provided along the vertical direction on the side surfaces of the lid and the container body. For example, the container disclosed in Patent Document 1 listed below has multiple ribs provided along the entire periphery of each of the side surfaces of the lid and the container body. By providing ribs on the side surfaces of the lid and the container body in this way, the side surfaces of the lid and the container body are less likely to be crushed during the lid closing operation, label attachment to the top surface, or stacking.

[0003] However, when the thickness of the sheet is thin, cracks and breakage easily occur in the top surface of the lid near the ribs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 59-26714 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a packaging container that can prevent both crushing damage to the side portions and cracking damage to the top portion of the lid, even when a thin sheet is used. [Means for solving the problem]

[0006] The packaging container according to the present invention is a packaging container comprising a container body and a lid body made of a synthetic resin sheet, the container body comprising a bottom surface, a body side surface extending upward from the peripheral edge of the bottom surface, and a body fitting portion provided on the outside of the body side surface, the body side surface having a body tensioning rib that protrudes inward and extends along the vertical direction, the lid body comprising a top surface, a lid side surface extending downward from the peripheral edge of the top surface, and a lid side surface extending outward from the lower end of the lid side surface and having a top surface of the body tensioning rib that is fitted to the top surface of the lid body when the lid is closed. and a lid fitting portion provided on the outside of the lid extension portion and fitting into the main body fitting portion in the closed state, the lid side portion is provided at a circumferential position corresponding to the main body tensioning rib and has a lid tensioning rib that protrudes outward and extends in the vertical direction, the lid tensioning rib and the main body tensioning rib are lined up one above the other in the closed state to form a tension column portion, and in a plan view in the closed state, the lower end of the lid tensioning rib is spaced inward from the upper end of the main body tensioning rib.

[0007] According to this configuration, main body tensioning ribs are provided along the vertical direction on the side surfaces of the main body, and lid tensioning ribs are provided along the vertical direction on the side surfaces of the lid. This increases the resistance to downward external forces acting on the top surface of the lid, preventing the lid side surfaces and the main body side surfaces from collapsing under compression. In particular, the lid tensioning ribs are provided at circumferential positions corresponding to the main body tensioning ribs, and the lid tensioning ribs and the main body tensioning ribs are aligned vertically to form a single tension column when the lid is closed. This enhances the tensioning function of the lid tensioning ribs and the main body tensioning ribs, allowing them to withstand large downward loads. Therefore, even if a large external force acts on the top surface of the lid, such as when closing the lid, attaching a label to the top surface with the lid closed, or stacking multiple packaging containers containing food one above the other, this effectively prevents the lid side surfaces and the main body side surfaces from collapsing under compression.

[0008] On the other hand, in a plan view in the closed state, the lower end of the lid tensioning rib does not overlap the upper end of the main body tensioning rib but is spaced inward from the upper end of the main body tensioning rib. When a large downward external force acts on the top surface of the lid when closing the lid or when the lid is in the closed state, the external force is transmitted to the upper end of the main body tensioning portion via the region of the lid extension between the lower end of the lid tensioning rib and the upper end of the main body tensioning rib in the inward / outward direction. This region of the lid extension is referred to as the cushion region. When a downward external force acts on the top surface of the lid, the cushion region elastically deforms, bending downward with the inner edge of the upper end of the main body tensioning rib as a fulcrum. This elastic deformation of the cushion region absorbs and alleviates the downward external force. Therefore, even when a large external force acts on the top surface of the lid when closing the lid or attaching a label to the top surface with the lid closed, the top surface of the lid is less likely to crack or break. Some automated devices, such as automatic lid closing devices and automatic labeling devices, have a narrow load adjustment range on the device side, but even when using such automated devices, the packaging container of this configuration makes it less likely for cracks or damage to occur in the top surface of the lid body, as external forces are absorbed and alleviated by the elastic deformation of the cushion area.

[0009] In particular, it is preferable that a pressure-receiving surface portion be provided at the upper end of the main body tensioning rib, and that a tapered surface portion be provided adjacent to the inside of the pressure-receiving surface portion, the tapered surface portion becoming more outward as it approaches the upper end. With this configuration, the pressure-receiving surface portion at the upper end of the main body tensioning rib receives force from the lid. The region of the lid extension portion between the outer edge of the tapered surface portion (the inner edge of the pressure-receiving surface portion) and the lower end of the lid tensioning rib in the inward / outward direction serves as a cushion region and elastically deforms. By providing the tapered surface portion adjacent to the inside of the pressure-receiving surface portion, the dimensions of the cushion region in the inward / outward direction are expanded. This makes the cushion region even more susceptible to elastic deformation, improves the external force absorption function of the cushion region, and more effectively prevents cracking and damage to the top surface of the lid.

[0010] The lid side surface portion has a lid side main portion that constitutes the vertical main portion of the lid side surface portion and is provided with a lid tensioning rib, and a lid step portion adjacent to the underside of the lid side main portion and connected to the lid extension portion, the lid step portion having a step upper surface portion extending outward from the lower end of the lid side main portion and a step side portion extending from the outer edge of the step upper surface portion to the lid extension portion, the lower end of the lid tensioning rib being located on the step upper surface portion, and preferably having an inwardly recessed portion provided at a location on the step side portion corresponding to the lid tensioning rib so as to locally extend the lid extension portion inward. With this configuration, since the lid tensioning rib is provided on the lid side main portion, which is a main portion of the lid side surface portion, the lid side surface portion can be effectively reinforced by the lid tensioning rib and can effectively prevent the lid side surface portion from being crushed by compression. In addition, a lid step is provided between the lid side main portion and the lid extension portion, and a lid tensioning rib extends to the step upper surface of the lid step portion, with the lower end of the lid tensioning rib located on the step upper surface. Therefore, the synergistic effect of the lid tensioning rib and the lid step portion can firmly reinforce the area near the lower end of the lid side portion in particular. Furthermore, a recess is provided in the step side portion of the lid step portion, and this recess locally expands the lid extension portion inward at a position corresponding to the lid tensioning rib. Therefore, the dimensions of the cushion area in the inward and outward directions are expanded, further improving the external force absorption function of the cushion area.

[0011] Furthermore, when the packaging container is rectangular in plan view, the lid tensioning ribs and the main body tensioning ribs are preferably provided at or near the corners. The corners or the vicinity of the corners are areas where a large force acts when closing the lid. Therefore, by providing the lid tensioning ribs and the main body tensioning ribs at or near the corners and providing a cushion area, it is possible to easily achieve both a tensioning function and an external force absorption function at or near the corners, and easily achieve both prevention of compression collapse of the lid side surfaces and the main body side surfaces and prevention of cracking and breakage of the lid top surface. [Effects of the Invention]

[0012] As described above, even when a thin sheet is used, it is possible to prevent the side surfaces of the lid and the main body from being crushed by compression and to prevent the top surface of the lid from cracking or breaking. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view showing a packaging container in an open state according to an embodiment of the present invention; [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] 5 is a cross-sectional view corresponding to AA in FIG. 4, showing the container in an open state. [Figure 6] 5 is a cross-sectional view corresponding to BB in FIG. 4, showing the container in an open state. [Figure 7] Cross section AA of Figure 4. [Figure 8] Cross section B-B of Figure 4. [Figure 9] FIG. 2 is a cross-sectional view taken along line AA showing the state in which an external force is applied to the container. [Figure 10] FIG. 8 is a cross-sectional view of the container showing a state where an external force is applied. DETAILED DESCRIPTION OF THE INVENTION

[0014] A packaging container according to one embodiment of the present invention will be described below with reference to the drawings. The packaging container shown in FIG. 1 comprises a container body 1 and a lid 2. The container body 1 has an opening at the top and can accommodate various contents. Various foods are particularly suitable as contents. The lid 2 is removably attached to the container body 1, and the opening of the container body 1 is closed by the lid 2. The lid 2 is attached to the container body 1 by engagement. In this embodiment, the type of engagement is an internal / external engagement structure that includes both internal and external engagement, but it may also be an internal engagement structure only, or it may have a side engagement structure.

[0015] The shape of the container in plan view is arbitrary and may be a polygon such as a rectangle in plan view, a circle, an ellipse, or the like. In this embodiment, the container is rectangular in plan view, specifically a rectangle that is long in a predetermined direction. Therefore, the container has four sides and four corners. Each side may be straight, or may be curved, for example, to bulge slightly outward. In addition, in plan view, the outside of the container is simply referred to as the outside, the inside of the container is simply referred to as the inside, the direction inward and outward from the container is simply referred to as the inward and outward direction, and the circumferential direction of the container is simply referred to as the circumferential direction.

[0016] Both the container body 1 and the lid 2 are made of synthetic resin sheets. The container body 1 and the lid 2 are formed by various thermoforming (sheet forming) methods such as vacuum forming and pressure forming. The synthetic resin sheets used for the container body 1 and the lid 2 may be the same or different. The synthetic resin sheets may be made of, for example, polyethylene terephthalate, polystyrene, polypropylene, polyethylene, or other polyolefins. Furthermore, as these sheet materials, sheets in which inorganic substances are dispersed in the aforementioned synthetic resins, foamed sheets in which the aforementioned synthetic resins are foamed, or stretched sheets in which the aforementioned sheets are stretched can be used. It is preferable to use a sheet with excellent transparency for the lid 2, and particularly, stretched sheets in which transparent polyethylene terephthalate, polystyrene, polypropylene, or the like are uniaxially or biaxially stretched are preferred.

[0017] <Container body 1> As shown in FIG. 1 , the container body 1 includes a bottom portion 10, a body side portion 11 extending upward from the periphery of the bottom portion 10, a body extension portion 12 extending outward from the upper end of the body side portion 11, a body fitting portion 13 provided on the outside of the body extension portion 12, and a body flange portion 14 provided on the outside of the body fitting portion 13. Although the body extension portion 12 is provided in this embodiment, the body extension portion 12 may be omitted. The upper surface of the bottom portion 10 may be provided with various shapes of upwardly protruding convex stripes or downwardly recessed stripes, as indicated by the two-dot chain line in FIG. 1 . Leg portions 15 may be provided on the lower surface of the bottom portion 10, protruding downward. In this embodiment, the legs 15 are provided at each of the four corners. The legs 15 are provided on the periphery of the corners of the bottom portion 10. Therefore, at the corners, the body side portion 11 extends upward from the outer edges of the legs 15.

[0018] The main body side surface portions 11 rise upward while expanding outward from the peripheral edge of the bottom surface portion 10. The main body side surface portions 11 are composed of four main body corner side surface portions 11a provided at each corner portion and four main body side surface portions 11b provided at each side portion. The main body corner side surface portions 11a are provided in a region of a predetermined length in the circumferential direction centered on the corner portion, and extend from the corner portion to the short side portion and the long side portion by a predetermined length, respectively. The main body side side surface portions 11b are provided between adjacent main body corner side surface portions 11a and connect adjacent main body corner side surface portions 11a. The main body corner side surface portions 11a are provided offset inward from the main body side side surface portions 11b.

[0019] The main body side surface portion 11 is provided with streak ribs 16 and main body tension ribs 17. Both the streak ribs 16 and the main body tension ribs 17 extend in the vertical direction. Both the streak ribs 16 and the main body tension ribs 17 are inward protrusions that protrude inward. The amount of protrusion of the main body tension ribs 17 in the inward and outward directions is greater than the amount of protrusion of the streak ribs 16 in the inward and outward directions. The amount of protrusion of the main body tension ribs 17 in the inward and outward directions is approximately constant over the entire length in the vertical direction. Furthermore, the circumferential dimension (width) of the main body tension ribs 17 is greater than the circumferential dimension of the streak ribs 16. Therefore, the main body tension ribs 17 are thick ribs and the streak ribs 16 are thin ribs. A large number of streak ribs 16 may be provided on the main body side surface portion 11, and may be provided continuously around the entire circumference of the main body side surface portion 11 or only partially around the entire circumference. The streak ribs 16 may be omitted. In this embodiment, the main body tensioning ribs 17 are provided only at or near the corners, but may also be provided, for example, at the center of the sides.

[0020] The main body tensioning ribs 17 are provided at each corner, specifically at the boundary between the corner and the side. More specifically, the main body tensioning ribs 17 are provided in pairs at circumferentially spaced intervals on the main body corner side surface 11a. Note that the main body tensioning ribs 17 provided at the short side end of the corner are sometimes referred to as the short side main body tensioning rib 171, and the main body tensioning rib 17 provided at the long side end of the corner are sometimes referred to as the long side main body tensioning rib 172.

[0021] The main body tensioning rib 17 is formed over the entire vertical length of the main body side surface portion 11. Therefore, the upper end 17a of the main body tensioning rib 17 is located at the upper end of the main body side surface portion 11, and the lower end of the main body tensioning rib 17 is located at the lower end of the main body side surface portion 11. The upper end 17a of the main body tensioning rib 17 is a closed end. A pressure-receiving surface portion 18 that is continuous with the main body extension portion 12 is provided at the upper end 17a of the main body tensioning rib 17. In this embodiment, the pressure-receiving surface portion 18 is provided over the entire upper end 17a of the main body tensioning rib 17. The pressure-receiving surface portion 18 is made of a horizontal plane, and the main body extension portion 12 and the pressure-receiving surface portion 18 are flush with each other.

[0022] It is preferable that a tapered surface portion 19 be provided adjacent to the inside of the pressure-receiving surface portion 18, with the tapered surface portion 19 being more outward as it approaches the upper side. The tapered surface portion 19 is an inclined surface. The tapered surface portion 19 is provided over the entire circumferential length (full width) of the main body tensioning rib 17. The tapered surface portion 19 may be provided on all main body tensioning ribs 17, but in this embodiment, it is provided only on the main body tensioning rib 171 on the short side out of the main body tensioning rib 172 on the long side and the main body tensioning rib 171 on the short side. Note that instead of the tapered surface portion 19, a curved surface portion that curves upward may be provided.

[0023] The lower end of the main body tensioning rib 17 is an open end that opens downward. As described above, a leg 15 is provided at each corner, and the main body side surface portion 11 extends upward from the outer edge of the leg 15. Therefore, the lower end of the main body tensioning rib 17 is located at the outer edge of the leg 15. Furthermore, the main body tensioning rib 17 is the part that protrudes most inward at the corner, and the inner surface of the main body tensioning rib 17 is the surface that is located most inward among the inner surfaces of the main body side surface portion 11 at the corner.

[0024] Furthermore, a main body protrusion 20 for preventing blocking may be provided at the upper end of the main body side portion 11 to prevent the so-called blocking phenomenon, in which the container bodies 1 become tightly fitted together and cannot be removed when a large number of container bodies 1 are stacked one on top of the other.

[0025] <Body extension part 12> The main body extension portion 12 extends horizontally outward from the upper end of the main body side portion 11, and the main body extension portion 12 is a flat surface. The main body extension portion 12 is preferably formed around the entire circumference. The height of the main body extension portion 12 may be constant around the entire circumference. Furthermore, the inner and outer dimensions of the main body extension portion 12 may be constant around the entire circumference, but in this embodiment, they are different at the side portions and corner portions.

[0026] The main body extension 12 consists of main body corner extensions 12a provided at each corner and main body side extensions 12b provided at each side. The main body corner extensions 12a are provided at locations around the entire circumference that correspond to the main body corner side portions 11a, and the main body side extensions 12b are provided at locations around the entire circumference that correspond to the main body side side portions 11b. The height of the main body corner extensions 12a is the same as the height of the main body side extensions 12b, and the main body corner extensions 12a and 12b are flush and continuous with each other. The inner and outer dimensions of the main body corner extensions 12a are larger than the inner and outer dimensions of the main body side side portions 11b, and the main body corner extensions 12a are relatively wide. The main body tensioning rib 17 mentioned above is connected to the main body corner extensions 12a, and the pressure-receiving surface portions 18 of the main body tensioning ribs 17 are flush and continuous with the main body corner extensions 12a.

[0027] <Main body fitting portion 13> The body fitting portion 13 is formed around the entire circumference. Therefore, body fitting portions 13 are provided not only on the four sides but also on the four corners. The body fitting portion 13 includes an internal body fitting portion 13a extending upward from the outer edge of the body extension portion 12, a body fitting top surface 13b extending outward from the upper end of the internal body fitting portion 13a, and an external body fitting portion 13c extending downward from the outer edge of the body fitting top surface 13b. The internal body fitting portion 13a may have various shapes, and one example is an inverted tapered shape that tapers inward toward the upper side. The body fitting top surface 13b connects the internal body fitting portion 13a and the external body fitting portion 13c in the inward and outward directions. The internal body fitting top surface 13b may be horizontal or may have a constant height around the entire circumference. The shape of the outer body fitting portion 13c may also be various, for example, a reverse tapered shape that tapers inward toward the bottom. Note that the upper end of the inner body fitting portion 13a and the upper end of the outer body fitting portion 13c may each be provided with a body chamfer 13d.

[0028] The main body flange portion 14 extends horizontally outward from the lower end of the main body outer fitting portion 13c. The main body flange portion 14 is formed around the entire circumference. It is preferable to form numerous extremely fine irregularities on the outer edge of the main body flange portion 14, which provides reinforcement and prevents finger cuts. These irregularities have a wave-like shape when viewed enlarged from the front, with the direction in which the numerous peaks and valleys extend in the width direction (inward and outward). The irregularities may be formed by knurling, such as flat knurling or twill knurling, and twill knurling is particularly preferable to form them to prevent slippage. Main body gripping portions 14a are provided at the corners of the main body flange portion 14.

[0029] <Lid 2> The lid body 2 includes a top surface 30, a lid side surface 31 extending downward from the peripheral edge of the top surface 30, a lid extension 32 extending outward from the lower end of the lid side surface 31, a lid fitting portion 33 provided on the outside of the lid extension 32, and a lid flange portion 34 provided on the outside of the lid fitting portion 33. The top surface 30 is preferably a flat surface without any irregularities.

[0030] The lid side surface portion 31 extends downward from the peripheral edge of the top surface portion 30 while widening as a whole. At the corner portion, the lid side surface portion 31 includes a lid side main portion 35 that constitutes the main portion of the lid side surface portion 31, and a lid step portion 36 provided adjacent to the lower side of the lid side main portion 35. The lid side main portion 35 is connected to the top surface portion 30 and extends downward from the peripheral edge of the top surface portion 30. The lid side main portion 35 accounts for most of the overall length of the lid side surface portion 31 in the vertical direction. The lid step portion 36 extends outward from the lower end of the lid side main portion 35. The lid step portion 36 is provided between the lid side surface main portion 35 and the lid extension portion 32, and is connected to the lower end of the lid side main portion 35 and the inner edge of the lid extension portion 32. The lid step portion 36 has a step upper surface portion 36a extending horizontally outward from the lower end of the lid side main portion 35, and a step side portion 36b hanging down from the outer edge of the step upper surface portion 36a to the lid extension portion 32.

[0031] Lid tension ribs 40 are provided at the corners of the lid side surface portion 31. The lid tension ribs 40 extend in the vertical direction. The lid tension ribs 40 are provided on the lid side surface main portion 35. The lid tension ribs 40 may be provided over most of the entire vertical length of the lid side surface main portion 35. The lid tension ribs 40 reach the lid step portion 36, and therefore the lower end portion 40a of the lid tension rib 40 is located on the step upper surface portion 36a. The lid tension ribs 40 are outward protrusions that protrude outward from the lid side surface main portion 35. The amount of protrusion of the lid tension ribs 40 in the inward and outward directions increases downward, and is greatest at the lower end portion 40a of the lid tension rib 40.

[0032] A lid tension rib 40 is provided at each corner. A pair of lid tension ribs 40 are provided at each corner, spaced apart in the circumferential direction. The lid tension ribs 40 provided at the short-side end of the corner are sometimes referred to as short-side lid tension ribs 401, and the lid tension ribs 40 provided at the long-side end of the corner are sometimes referred to as long-side lid tension ribs 402. The lid tension ribs 40 are provided at circumferential positions corresponding to the main body tension ribs 17.

[0033] The outer edge of the lid step portion 36 is provided with an inwardly recessed cutout portion 50. The cutout portion 50 is provided on the step side portion 36b and extends over the entire vertical length of the step side portion 36b. The cutout portion 50 may have any shape, such as a rectangular, V-shape, or U-shape in plan view, but in this embodiment, it is arc-shaped in plan view. The cutout portion 50 is provided in a position corresponding to the lid tension rib 40 and continues below the lid tension rib 40. Since a pair of lid tension ribs 40 is provided at each corner portion, a corresponding pair of cutout portions 50 is also provided at each corner portion. By providing the recess 50 in the step side portion 36b, the inward and outward dimensions of the step upper surface portion 36a are locally reduced at the location where the recess 50 is formed, and the amount of inward and outward protrusion at the lower end portion 40a of the lid tensioning rib 40 is equal to the inward and outward dimensions of the step upper surface portion 36a at the location where the recess 50 is formed.

[0034] In order to prevent the so-called blocking phenomenon, in which the lid bodies 2 become tightly fitted together and cannot be removed when many lid bodies 2 are stacked one on top of the other, a lid protrusion 60 may be provided at the bottom of the lid side surface portion 31. The lid protrusion 60 may be provided in an outward protruding position to prevent blocking, but the lid protrusion 60 may be positioned arbitrarily, but in this embodiment, the lid protrusion 60 is provided at the corner, at the lower end of the lid side main portion 35.

[0035] Each edge of the lid side surface 31 is provided with a panel portion 61, which is an inclined surface. The panel portion 61 is provided over the entire vertical length of the edge of the lid side surface 31, excluding the upper and lower ends. The panel portion 61 connects adjacent lid side surface main portions 35 and adjacent lid step portions 36 in the circumferential direction. The slope of the panel portion 61 is gentler than the slope of the lid side surface main portion 35. In other words, the inclination angle (rise angle) of the lid side surface main portion 35 with respect to the horizontal plane is greater than the inclination angle of the panel portion 61, and the lid side surface main portion 35 has a steeper slope than the panel portion 61. It is preferable that the panel portion 61 does not have any unevenness such as ribs. By making the panel portion 61 a smooth surface, visibility when viewing the interior through the panel portion 61 can be easily ensured.

[0036] <Lid extension part 32> The lid extension 32 extends horizontally outward from the lower end of the lid side surface 31, and is a flat surface. The dimension (width) of the lid extension 32 in the inward and outward directions may be constant around the entire periphery, except for the location of the above-mentioned hollowed-out portion 50. In other words, by forming the hollowed-out portion 50, the lid extension 32 is locally expanded inward at the location of the hollowed-out portion 50, and the dimension of the lid extension 32 in the inward and outward directions is larger at the location of the hollowed-out portion 50 than at other locations.

[0037] <Lid fitting portion 33> The lid fitting portion 33 is formed around the entire periphery. Therefore, the lid fitting portion 33 is provided not only on the four sides but also on the four corners. The lid fitting portion 33 includes a lid inner fitting portion 33a extending upward from the outer edge of the lid extension portion 32, a lid fitting top surface 33b extending outward from the upper end of the lid inner fitting portion 33a, and a lid outer fitting portion 33c extending downward from the outer edge of the lid fitting top surface 33b. The lid inner fitting portion 33a fits inside the main body inner fitting portion 13a. The lid inner fitting portion 33a may have various shapes, but is shaped to correspond to the shape of the lid inner fitting portion 33a. One example is a reverse tapered shape that tapers inward toward the upper side. The lid fitting top surface 33b connects the lid inner fitting portion 33a and the lid outer fitting portion 33c inward and outward directions. The lid fitting top surface 33b may be a horizontal plane and may have a constant height around the entire periphery. The shape of the lid outer fitting portion 33c may also be various, but is a shape that corresponds to the shape of the lid outer fitting portion 33c, and one example is a reverse tapered shape that tapers upward from the bottom. Note that a lid chamfer 33d may be provided at the upper end of the lid inner fitting portion 33a and the upper end of the lid outer fitting portion 33c, respectively.

[0038] <Lid flange part 34> The lid flange 34 extends horizontally outward from the lower end of the lid outer fitting portion 33c. The lid flange 34 is formed around the entire periphery. The outer edge of the lid flange 34 is preferably provided with numerous extremely fine irregularities, which provide reinforcement and prevent finger cuts. These irregularities are wavy when viewed enlarged from the front, with the direction of the numerous peaks and valleys extending in the width direction (inward / outward direction). The irregularities may be formed by knurling, such as flat knurling or twill knurling, with twill knurling being particularly preferred to prevent slippage. Lid grips 34a are provided at the corners of the lid flange 34.

[0039] <Lid closed> In the closed state, the lid extension 32 faces the upper side of the main body extension 12. As described above, the upper end 17a of the main body tensioning rib 17 is provided with a pressure-receiving surface 18 that is flush with and continuous with the main body extension 12. That is, the lid extension 32 faces the upper side of the main body tensioning rib 17. The lid extension 32, the main body extension 12, and the pressure-receiving surface 18 may be parallel to one another. It is preferable to form gaps between the lid extension 32, the main body extension 12, and the pressure-receiving surface 18 in the vertical direction, but the lid extension 32 may abut against the main body extension 12 or the pressure-receiving surface 18. The lid fitting 33 fits into the main body fitting 13. Specifically, the lid internal fitting 33a fits inside the main body internal fitting 13a, and the lid external fitting 33c fits outside the main body external fitting 13c. The lid fitting top surface 33b faces the upper side of the main body fitting top surface 13b. The lid fitting top surface 33b and the main body fitting top surface 13b may be parallel to each other. A gap may be formed between the lid fitting top surface 33b and the main body fitting top surface 13b in the vertical direction, or the lid fitting top surface 33b may abut against the main body fitting top surface 13b without a gap. The lid flange 34 faces the upper side of the main body flange 14. A gap may be formed between the lid flange 34 and the main body flange 14 in the vertical direction, or the lid flange 34 may abut against the main body flange 14 without a gap. In addition, in a plan view, it is preferable that the outer edge of the lid knob 34a protrudes outward beyond the outer edge of the main body knob 14a.

[0040] The lid tension ribs 40 and the main body tension ribs 17 are positioned in the same circumferential position, with the main body tension ribs 17 located below the lid tension ribs 40. In detail, the main body tension ribs 171 on the short side are positioned below the lid tension ribs 401 on the short side in the same circumferential position, and the main body tension ribs 172 on the long side are positioned below the lid tension ribs 402 on the long side in the same circumferential position. In this way, the lid tension ribs 40 and the main body tension ribs 17 are aligned in a straight line vertically, so that the lid tension ribs 40 and the main body tension ribs 17 form a single tension column portion vertically.

[0041] In this way, the lid tensioning rib 40 and the main body tensioning rib 17 form a single tensioning column that cooperates with each other to provide tension against external forces in the vertical direction. Therefore, even if a large downward external force acts on the corner of the top surface 30 of the lid 2 when closing the lid 2, when attaching a label to the top surface 30 with the lid closed, or when multiple packaging containers containing food are stacked one on top of the other, the lid tensioning rib 40 and the main body tensioning rib 17 work together to provide tension against the external force. This effectively prevents the lid side surface 31 and the main body side surface 11 from being crushed by compression.

[0042] On the other hand, the lid tensioning ribs 40 and the main body tensioning ribs 17 are misaligned inward and outward in plan view. More specifically, in plan view, the lower end portions 40a of the lid tensioning ribs 40 are misaligned inward with respect to the pressure-receiving surface portions 18 of the main body tensioning ribs 17. In plan view, the lower end portions 40a of the lid tensioning ribs 40 do not overlap with the pressure-receiving surface portions 18 of the main body tensioning ribs 17, and are spaced inward from the pressure-receiving surface portions 18.

[0043] Figures 5 and 6 show longitudinal cross-sectional views of a corner portion in the open state. Figure 5 is a longitudinal cross-sectional view showing the relationship between the short-side lid tension rib 401 and the short-side main body tension rib 171, and Figure 6 is a longitudinal cross-sectional view showing the relationship between the long-side lid tension rib 402 and the long-side main body tension rib 172. Figures 7 and 8 show longitudinal cross-sectional views of a corner portion in the closed state. Figure 7 corresponds to Figure 5, and Figure 8 corresponds to Figure 6. In Figures 7 and 8, the reference characters D1 and D2 indicate the inner and outer distances between the outer edge of the lower end 40a of the lid tension rib 40 and the inner edge of the pressure-receiving surface 18 of the main body tension rib 17. As described above, the inner edge of the upper end 17a of the short-side main body tension rib 171 has a tapered surface 19, while the inner edge of the upper end 17a of the long-side main body tension rib 172 does not have a tapered surface 19. Therefore, the inward / outward separation distance D1 between the outer edge of the lower end 40a of the lid tensioning rib 40 on the short side and the inner edge of the pressure-receiving surface portion 18 of the main body tensioning rib 17 is greater than the separation distance D2 on the long side.

[0044] Because the lower end portions 40a of the lid tensioning ribs 40 are spaced inward from the pressure-receiving surface portions 18 of the main body tensioning ribs 17 in this way, when a downward external force acts on the top surface 30 of the lid body 2, the external force is not transmitted directly to the pressure-receiving surface portions 18 of the main body tensioning ribs 17, but is transmitted to the pressure-receiving surface portions 18 of the main body tensioning portion via a region of the lid extension portions 32 between the outer edge of the lower end portions 40a of the lid tensioning ribs 40 and the inner edge of the pressure-receiving surface portions 18 of the main body tensioning ribs 17 in the inward / outward directions. This region of the lid extension portions 32 between the outer edge of the lower end portions 40a of the lid tensioning ribs 40 and the inner edge of the pressure-receiving surface portions 18 of the main body tensioning ribs 17 in the inward / outward directions is referred to as a cushion region 70. The downward external force acting on the top surface 30 of the lid body 2 is transmitted from the lid tensioning ribs 40 to the main body tensioning ribs 17 via the cushion region 70. The cushion region 70 is the location of the hollowed-out portion 50 in the lid extension 32. Therefore, the cushion region 70 is a portion where the lid extension 32 locally expands inward, and has a larger dimension in the inward and outward directions than the portion other than the hollowed-out portion 50.

[0045] In this embodiment, the main body tensioning rib 171 on the short side is provided with a tapered surface portion 19. Therefore, the dimension of the cushion region 70 in the inward and outward directions is larger on the short side than on the long side.

[0046] 9 and 10 show the state of the container when a large downward external force acts on a corner of the top surface 30 of the lid 2. FIG. 9 corresponds to FIG. 7, and FIG. 10 corresponds to FIG. 8. When a large downward external force acts on a corner of the top surface 30 of the lid 2, the external force is transmitted to the cushion region 70 via the lid tensioning rib 40. The cushion region 70 receives the downward force from the lower end 40a of the lid tensioning rib 40 and elastically deforms downward with the inner edge of the pressure-receiving surface 18 as a fulcrum. This elastic deformation of the cushion region 70 absorbs and alleviates the downward external force. Therefore, even if a large external force acts on the top surface 30 of the lid 2 when closing the lid 2 or attaching a label to the top surface 30 with the lid closed, the top surface 30 of the lid 2 is less likely to crack or break. In particular, by providing a tapered surface portion 19 inside the pressure-receiving surface portion 18, the cushion area 70 is expanded, allowing the cushion area 70 to easily elastically deform, increasing the external force absorption function of the cushion area 70 and effectively preventing cracking and damage to the bottom surface portion 10 of the lid body 2.

[0047] Furthermore, by providing a hollow portion 50 in the lid step portion 36, the cushion region 70 can be easily provided and the cushion region 70 can also be easily enlarged. Note that in this embodiment, the cushion region 70 is provided by forming a hollow portion 50 in the lid step portion 36, but the cushion region 70 may also be provided by enlarging the dimensions of the lid extension portion 32 in the inward and outward directions by offsetting the outer edge of the lid step portion 36 inward along its entire circumferential length, without providing a hollow portion 50. [Explanation of symbols]

[0048] 1 Container body 2 Lid 10 Bottom part 11 Side of the main body 11a Main unit corner side 11b Main body side part 12 Main body extension 12a Main body corner extension 12b Body side extension 13 Main body fitting part 13a Main body internal fitting portion 13b Main body fitting top surface part 13c Main body outer fitting part 13d Chamfered part of the main body 14 Main body flange 14a Main body knob 15 Legs 16 streaky ribs 17 Body tension rib 17a Upper end 171 Short side body tension rib 172 Long side body tension rib 18 Pressure receiving surface 19 Tapered surface 20 Protrusion on the main body 30 Top section 31 Lid side part 32 Lid extension 33 Lid fitting part 33a Inner lid fitting part 33b Lid fitting top surface part 33c Lid outer fitting part 33d Lid chamfer 34 Lid flange 34a Lid knob 35 Main part of the lid side 36 Lid step part 36a Upper surface of step 36b Step side 40 Lid tension rib 40a Bottom end 401 Short side lid tension rib 402 Lid tension rib on long side 50 Hollowed out part 60 Lid protrusion 61 Panel section 70 cushion area

Claims

1. A packaging container having a container body and a lid body made of a synthetic resin sheet, The container body includes a bottom surface portion, a body side surface portion extending upward from a peripheral edge portion of the bottom surface portion, and a body fitting portion provided on the outer side of the body side surface portion, The side surface of the main body includes a main body tensioning rib that protrudes inward and extends in the vertical direction, The lid body includes a top surface portion, a lid side surface portion extending downward from the peripheral edge portion of the top surface portion, a lid extension portion extending outward from the lower end portion of the lid side surface portion and facing the upper side of the main body tensioning rib in the closed state, and a lid fitting portion provided on the outside of the lid extension portion and fitting into the main body fitting portion in the closed state, The lid side surface portion is provided with a lid tension rib that is provided at a circumferential position corresponding to the main body tension rib, protrudes outward, and extends along the up-down direction; The lid tensioning rib and the main body tensioning rib are arranged vertically to form a tension column when the lid is closed, A packaging container in which, when viewed in a plan view in the closed state, the lower end of the lid tensioning rib is spaced inward from the upper end of the body tensioning rib.

2. 2. The packaging container according to claim 1, wherein a pressure-receiving surface portion is provided at the upper end of the main body tensioning rib, and a tapered surface portion that becomes outward as it approaches the upper side is provided adjacent to the inside of the pressure-receiving surface portion.

3. The lid side surface portion has a lid side main portion that constitutes a main portion of the lid side surface portion in the up-down direction and is provided with a lid tensioning rib, and a lid step portion that is adjacent to the underside of the lid side main portion and is connected to the lid extension portion, the lid step portion has a step upper surface portion extending outward from a lower end of the lid side main portion, and a step side surface portion extending from an outer edge of the step upper surface portion to the lid extension portion; The lower end of the lid tensioning rib is located on the upper surface of the step, 3. The packaging container according to claim 1, wherein a recessed portion is provided inward at a location on the stepped side surface corresponding to the lid tensioning rib so as to locally extend the lid extension portion inward.

4. The packaging container is rectangular in plan view, 3. The packaging container according to claim 1, wherein the lid tensioning rib and the body tensioning rib are provided at or near the corners.

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