Inner tray for packaging containers

Abstract

To provide a packaging container and an inner tray which can easily ensure sealing while forming upper and lower spaces inside with an inner tray, and can also easily ensure sealing even when a lid body is directly attached to the container body without using the inner tray. [Solution] A food packaging container (1) comprising a container body (2) having an opening (M), a lid body (4) that closes the opening (M), and an inner tray (3) arranged between the container body (2) and the lid body (4), wherein the container body (2) has a fitting receiving portion (24) provided on the upper part of the peripheral wall (22), the lid body (4) has a lid body fitting portion (45) that can fit into the inner surface Fa of the fitting receiving portion (24), and the inner tray (3) has a partition portion (31) that separates a lower space (Sa) and an upper space (Sb), an interior fitting portion (36) that fits into the inner surface Fa of the fitting receiving portion (24), an exterior fitting portion (37) that fits into the outer surface of the lid body fitting portion (45), and a dimensional difference adjustment portion (5) that expands in diameter and protrudes from the upper part of the interior fitting portion (36) and is connected to the lower part of the exterior fitting portion (37).

Description

Technical Field

[0001] The present invention relates to a packaging container and an inner tray for accommodating food and the like therein.

Background Art

[0002] There is a disposable packaging container made of foamed resin that can accommodate food and the like inside, and a lid can close the opening of the container so that the inside of the container can be isolated from the outside. In particular, in a fitting method generally called an inner fitting lid type, the lid fits onto the inner surface of the container body to close the opening and isolate the inside from the outside. By using a flexible container body made of foamed synthetic resin, there is a high demand as a disposable packaging container in the food field.

[0003] In such a container, a packaging container further provided with an inner tray that forms upper and lower spaces inside is known. For example, Patent Document 1 discloses a second container body corresponding to an inner tray. In this type of packaging container, the fitting portion of the inner tray is sandwiched and attached between the fitting portion of the container body and the fitting portion of the lid.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional packaging container assuming the use of an inner tray, when the lid is fitted to the container body without using the inner tray, the fitting becomes loose by the thickness of the inner tray, resulting in poor sealing performance and the lid being easily detached from the container body. Therefore, in a conventional packaging container, it is not practical to directly fit the lid to the container body without using the inner tray, and no device has been made under such an assumption.

[0006] The present invention aims to provide a packaging container and an inner tray that facilitate sealing while creating an upper and lower space inside using an inner tray, and further facilitate sealing even when the lid is directly attached to the container body without using an inner tray. [Means for solving the problem]

[0007] The present invention relates to a packaging container comprising: a container body having an opening on the opposite side of the bottom; a lid that closes the opening; and an inner tray disposed between the container body and the lid, forming a lower space on the bottom side and an upper space on the opening side inside the container body. The container body comprises a peripheral wall that forms the opening and a fitting receiving portion provided on the upper part of the peripheral wall. The lid comprises a cover portion that covers the opening and a lid fitting portion provided along the outer edge of the cover portion and having an outer diameter that can be fitted to the inner circumferential surface of the fitting receiving portion. The inner tray comprises a partition portion that separates the lower space and the upper space, an interior fitting portion erected along the periphery of the partition portion and fitted to the inner circumferential surface of the fitting receiving portion, an exterior fitting portion fitted to the outer circumferential surface of the lid fitting portion, and a dimensional difference adjustment portion that expands in diameter from the upper part of the interior fitting portion and is connected to the lower part of the exterior fitting portion.

[0008] This packaging container is equipped with an inner tray that forms a lower space and an upper space inside the container body. The inner fitting portion of the inner tray fits onto the inner circumferential surface of the fitting receiving portion of the container body, ensuring a seal in the lower space. The outer fitting portion fits onto the outer circumferential surface of the lid fitting portion of the lid, ensuring a seal in the upper space. Furthermore, the lid fitting portion of the lid has an outer diameter that allows it to fit onto the inner circumferential surface of the fitting receiving portion. Therefore, if the inner tray is not used, the lid fitting portion of the lid can be directly fitted onto the inner circumferential surface of the fitting receiving portion to ensure a seal. On the other hand, if the lid fitting portion is made to fit onto the inner circumferential surface of the fitting receiving portion, a dimensional difference will occur between the inner fitting portion and the outer fitting portion of the inner tray. However, this dimensional difference is absorbed by the dimensional difference adjustment portion, so no force is applied when installing the inner tray. Therefore, the inner tray makes it easier to ensure a seal while creating an upper and lower space inside, and furthermore, it also makes it easier to ensure a seal even when the lid is attached directly to the container body without using the inner tray.

[0009] In the above-described packaging container, the dimensional difference adjustment section may extend in the height direction from which the outer fitting section is erected, and may also include an expanding wall section that widens the upper space. Including an expanding wall section makes it easier to widen the upper space.

[0010] In the above-described packaging container, the depth of the upper space may be greater than the depth of the lower space, based on the height from the bottom of the container body to the cover portion of the lid. This allows for effective use of the upper space when storing food or other items inside the container body.

[0011] In the above-described packaging container, the inner fitting portion may have a lower protrusion that protrudes outward, and the fitting receiving portion may have a lower recess that accommodates the lower protrusion. The engagement between the lower protrusion of the inner fitting portion and the lower recess of the fitting receiving portion prevents the inner tray from unintentionally detaching from the container body.

[0012] In the above-described packaging container, the interior fitting portion may include a lower sealing portion that is in close contact with the lower recess, continuously forming a closed annular shape in the circumferential direction along the outer edge of the opening. Providing a lower sealing portion is advantageous for improving the sealing performance of the lower space.

[0013] In the above-described packaging container, the lid fitting portion may include an upper recess that is continuous in a closed annular shape in the circumferential direction along the outer edge of the opening, and the outer fitting portion may include an upper sealing portion that is continuous in a closed annular shape in the circumferential direction along the outer edge of the opening and is in close contact with the upper recess. Providing an upper sealing portion is advantageous for improving the sealing performance of the upper space.

[0014] The present invention also relates to an inner tray for a packaging container, which is positioned between a container body and a lid, whose peripheral edges can be fitted together, and which forms a lower space and an upper space inside the container body, comprising: a partition portion that separates the lower space and the upper space; an interior fitting portion erected along the peripheral edge of the partition portion and which can be fitted to the inner circumferential surface of the fitting receiving portion of the container body; an exterior fitting portion that can be fitted to the outer circumferential surface of the lid fitting portion of the lid; and a dimensional difference adjustment portion that expands in diameter from the upper part of the interior fitting portion and is connected to the lower part of the exterior fitting portion.

[0015] This inner tray makes it easier to ensure a seal while creating an upper and lower space inside the packaging container, and furthermore, it also makes it easier to ensure a seal even when the lid is attached directly to the container body without using the inner tray. [Effects of the Invention]

[0016] According to the present invention, it is easy to ensure a seal while forming an upper space and a lower space inside using the inner tray, and furthermore, it is easy to ensure a seal even when the lid is attached directly to the container body without using the inner tray. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a perspective view of a food packaging container according to an embodiment. [Figure 2] Figure 2 is a perspective view showing the food packaging container according to the embodiment with the lid removed. [Figure 3] Figure 3 is a side view of a food packaging container according to an embodiment. [Figure 4] Figure 4 is a cross-sectional view along the line VI-VI in Figure 3. [Figure 5] Figure 5 is a cross-sectional view corresponding to Figure 4, showing the state in which the lid is directly attached to the container body. [Figure 6] Figure 6 is a schematic cross-sectional view of a food packaging container according to an embodiment, where (a) is a cross-sectional view showing the container with the inner tray attached, and (b) is a cross-sectional view showing the container without the inner tray. [Figure 7] Figure 7 is a schematic cross-sectional view of a food packaging container relating to a comparative form, where (a) is a cross-sectional view showing the container with the inner tray attached, and (b) is a cross-sectional view showing the container without the inner tray. [Figure 8] Figure 8 is a cross-sectional view showing an enlarged view of the fitting portion of a food packaging container according to another embodiment. [Figure 9]FIG. 9 is a diagram for explaining a method of changing the internal volume by mounting different types of inner dishes. FIG. (a) shows a food packaging container according to an embodiment without an extended wall, FIG. (b) shows a food packaging container according to another embodiment with an extended wall, and FIG. (c) shows a modified example of a food packaging container according to another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, a food packaging container 1 (an example of a "packaging container") according to an embodiment of the present invention will be described with reference to the drawings. The food packaging container 1 is a container for accommodating an article containing food (hereinafter referred to as "food etc. F"). Food etc. F widely includes rice, noodles, raw vegetables, various prepared foods, seasonings and soups, etc., and further includes utensils related to meals such as spoons, forks or chopsticks.

[0019] The food packaging container 1 includes a container body 2, a lid 4 that closes the opening M of the container body 2, and an inner dish 3 disposed between the container body 2 and the lid 4. The peripheral edges of the container body 2 and the lid 4 can be fitted to each other. The technical meaning of the lid 4 closing the opening M means that in the state where the inner dish 3 is mounted, the opening M is indirectly closed via the inner dish 3, and in the state where the inner dish 3 is not used and omitted, the opening M is directly closed.

[0020] Inside the container body 2, a lower space Sa on the bottom 21 side and an upper space Sb on the opening M side are formed by the inner dish 3. Different food etc. F (see FIG. 4) may be accommodated in the upper space Sb and the lower space Sa, or the same food etc. F may be accommodated. For example, noodles may be accommodated in the lower space Sa, and prepared foods as toppings may be put in the upper space Sb. Also, rice and various prepared foods may be accommodated in the lower space Sa, and chopsticks, spoons, etc. may be accommodated in the upper space Sb.

[0021] The container body 2 is formed by molding a sheet of foamed synthetic resin material into a predetermined container shape, such as a mortar-shaped container, within a mold. The lid 4 and inner tray 3 are components formed by molding a sheet of synthetic resin material into a predetermined lid shape for the container body 2.

[0022] Generally, foamed synthetic resin sheet material is used as the material for the container body 2. Typical foamed synthetic resin sheet materials include various synthetic resin sheets such as polyethylene terephthalate, polystyrene, polypropylene, and polyolefins such as polyethylene. In particular, among these, foamed polystyrene sheets made by foaming polystyrene, and heat-resistant foamed polystyrene sheets made by foaming polystyrene with excellent heat resistance are preferred. Examples of such foamed sheets include foamed sheets made by kneading and extruding foamed styrene sheets together with a physical blowing agent such as butane or pentane, a chemical blowing agent such as azodicarbonamide, or a blowing agent such as carbon dioxide, nitrogen, or air in an extruder, or foamed sheets made by laminating a resin film on one or both sides thereof. Furthermore, a non-foamed sheet may be used as the material for the container body 2. For example, various synthetic resin sheets such as polyethylene terephthalate, polystyrene, polypropylene, and polyethylene or other polyolefins can be used.

[0023] Generally, a transparent synthetic resin sheet material is used as the material for the lid 4. Typical transparent synthetic resin sheet materials include various synthetic resin sheets such as polyethylene terephthalate, polystyrene, polypropylene, and polyolefins such as polyethylene. In particular, among these, polystyrene sheets obtained by biaxial stretching of polystyrene are preferred, and for microwave heating, heat-resistant biaxially stretched styrene resin sheets are preferred. Examples of such transparent sheets include styrene resin alone, or copolymer resins of monomers such as methacrylic acid and styrene monomer.

[0024] For the inner tray 3, various synthetic resin sheets can be used, such as polyethylene terephthalate, polystyrene, polypropylene, and polyolefins such as polyethylene. For microwave heating, it is preferable to use polypropylene or a sheet made of polypropylene with fillers such as talc.

[0025] The container body 2 can be molded using various sheet molding methods. Examples of sheet molding methods include vacuum forming, pressure forming, vacuum pressure forming, and double-sided vacuum forming. The container can be formed by thermoforming a synthetic resin sheet using any of these methods. In particular, when molding a foamed sheet, match molding, which consists of an outer mold and an inner mold, is suitable.

[0026] The lid 4 and the inner tray 3 can also be formed using various sheet molding methods. Examples of sheet molding methods include vacuum forming, pressure forming, vacuum pressure forming, and double-sided vacuum forming. These can be formed by thermoforming a synthetic resin sheet using any of these methods. In particular, when forming a stretched sheet, hot plate forming, in which the sheet is sandwiched between a heated plate and a mold, is suitable.

[0027] As shown in Figures 1, 2, 3, and 4, the container body 2 has a base at the bottom 21, an opening M larger than the size of the bottom 21, and a hollow, inverted truncated cone shape inside. In this embodiment, we will define and explain the top and bottom based on the assumption that the container body 2 is placed on a horizontal stand, with the bottom 21 located on the lower side in the vertical direction and the opening M located on the upper side in the vertical direction.

[0028] The container body 2 comprises a bottom portion 21 and a peripheral wall 22 erected from the periphery of the bottom portion 21. The upper end portion of the area enclosed by the peripheral wall 22 is open, forming an opening M. Food F and the inner tray 3 are inserted and removed through the opening M. The shape of the opening M can be selected from a circle, an ellipse, a polygon, etc. The shape of the peripheral wall 22 can be any shape to match the shape of the opening M. In this embodiment, a peripheral wall 22 exhibiting the shape of a so-called "mortar" will be described as an example. A fitting receiving portion 24 for fitting into the inner tray 3 or lid 4 is provided at the upper part of the peripheral wall 22.

[0029] The inner tray 3 comprises a partition portion 31, an inner tray fitting portion 35 erected along the periphery of the partition portion 31, a lid positioning portion 38 provided so as to protrude outward from the upper part of the inner tray fitting portion 35, and a skirt portion 39 formed at the tip of the lid positioning portion 38.

[0030] The partition 31 divides the inside of the container body 2 into a lower space Sa on the bottom 21 side and an upper space Sb on the opening M side. The partition 31 includes a tray portion 32 on which food or the like F is placed, an inner wall portion 33 erected along the periphery of the tray portion 32, and a latching portion 34 protruding outward from the upper end of the inner wall portion 33. The inner tray fitting portion 35 is erected along the periphery of the latching portion 34. The inner tray fitting portion 35 is fitted into the fitting receiving portion 24 of the container body 2 and is also fitted into the lid 4. In this embodiment, a portion of the inner wall portion 33 protrudes toward the partition 31 side, forming a block-shaped bulge portion 33a (see Figure 2). A U-shaped groove 33b that can be opened and closed is formed in the ceiling portion of the bulge portion 33a, which serves as a steam vent.

[0031] The lid positioning portion 38 has a mounting surface that receives the flange portion 46, which is the outer edge of the lid 4. The skirt portion 39 is a part that bends downward from the tip of the lid positioning portion 38 and abuts against the outer edge of the curved protrusion 24c of the container body 2.

[0032] The lid 4 has a bulge above the opening M in the central part of the container body 2, and is designed to prevent food or other items F inside the container body 2 from coming into contact with the inner surface of the lid 4. Specifically, the lid 4 comprises a cover portion 41 that indirectly covers the opening M of the container body 2 via the inner tray 3, and a lid fitting portion 45 provided along the outer edge of the cover portion 41 and fitted into the inner tray fitting portion 35. The lid 4 may also be provided with steam vents depending on the food or other items F to be stored inside.

[0033] The cover portion 41 has a shape resembling an inverted cup, with a bulge inside. The cover portion 41 comprises a ceiling portion 43 that primarily covers the food or other items F placed on the inner tray 3 or the food or other items F contained inside the container body 2, and a side wall portion 44 provided along the periphery of the ceiling portion 43. The side wall portion 44 comprises an inclined side surface portion 44a that is connected to the ceiling portion 43 and widens in diameter in a tapered manner, a cylindrical portion 44b connected to the inclined side surface portion 44a, and an annular connecting portion 44c that protrudes outward from the lower end of the cylindrical portion 44b.

[0034] The fitting receiving portion 24 of the container body 2 is provided so as to surround the opening M. The fitting receiving portion 24 is fitted into the inner tray fitting portion 35 of the inner tray 3 or the lid fitting portion 45 of the lid 4, and as a result the opening M is closed. By closing the opening M with the inner tray 3 or the lid 4, the inside of the container body 2 is isolated from the outside, and the container 1 can perform its intended function as a food packaging container.

[0035] Next, referring to Figure 4, the fitting structure of the container body 2, the inner tray 3, and the lid 4 will be explained. In the following explanation, "inward" refers to the direction facing inward with respect to the container body 2, that is, the direction toward the inside (center) of the radial direction of the container body 2. On the other hand, "outward" refers to the direction opposite to "inward". Furthermore, the inner circumferential surface refers to the surface facing inward, and the outer circumferential surface refers to the surface facing outward.

[0036] The container body 2 is provided with a peripheral wall 22 that forms an opening M. The peripheral wall 22 includes a side wall portion 23 that is erected at an angle so as to increase in inner diameter (area in plan view) from the bottom 21 of the container body 2 to the opening M, and a fitting receiving portion 24 provided on the upper part of the side wall portion 23. The fitting receiving portion 24 includes a lower recess portion 24a provided at the boundary with the side wall portion 23, a main body fitting wall portion 24b erected from the lower recess portion 24a, and a curved protrusion portion 24c that curves outward from the upper part of the main body fitting wall portion 24b.

[0037] The lower recess 24a of the fitting receiver 24 is formed, for example, in the molding process of forming the container body 2, such that the thickness of the wall surface of the container body 2 remains almost constant while exhibiting a curved shape due to the shape of the mold. In other words, when viewed in cross-section of the container body 2, the outer and inner shapes of the lower recess 24a are curved to protrude outward (outward in the thickness direction) from the lower recess 24a (container body 2), and the recess is defined as the inner curved surface. The recess of the lower recess 24a is continuous in a closed annular shape in the circumferential direction along the outer edge of the opening M of the container body 2.

[0038] A main body fitting wall portion 24b is formed above the lower recess portion 24a. The main body fitting wall portion 24b is erected while curving upward from the lower recess portion 24a, and the inner circumferential surface of the main body fitting wall portion 24b has a curved shape that bulges inward in cross-sectional view. Due to the effect of the curved shape of the inner circumferential surface of the main body fitting wall portion 24b, smooth attachment of the lid fitting portion 45 is possible.

[0039] The inner tray 3 is equipped with an inner tray fitting portion 35 erected along the periphery of the latching portion 34 (the periphery of the partition portion 31). The inner tray fitting portion 35 comprises a lower interior fitting portion 36, an upper exterior fitting portion 37, and a dimensional difference adjustment portion 5 connecting the interior fitting portion 36 and the exterior fitting portion 37. The interior fitting portion 36 is fitted in contact with the inner circumferential surface Fa of the fitting receiving portion 24 of the container body 2. The exterior fitting portion 37 is in contact with the outer circumferential surface Fb of the lid fitting portion 45.

[0040] The inner plate fitting portion 35 is formed by bending the sheet material using a predetermined mold and has substantially the same thickness. In addition, the inner fitting portion 36, the outer fitting portion 37, and the dimensional difference adjustment portion 5 are formed with a flexible shape and thickness so that minute deformation is possible due to the elasticity inherent in the sheet material.

[0041] The interior fitting portion 36 comprises a lower projection 36a connected to the latching portion 34 (partition portion 31) and a lower fitting wall portion 36b connected to the upper part of the lower projection 36a. The lower projection 36a protrudes outward at an angle from the latching portion 34 and has a shape that is folded back midway. The bent top of the lower projection 36a is continuous in a closed annular shape in the circumferential direction along the outer edge of the opening M of the container body 2. The lower fitting wall portion 36b is cylindrical and erected from the upper part of the lower projection 36a. In this embodiment, the lower projection 36a and the lower fitting wall portion 36b have substantially the same thickness.

[0042] When the interior fitting portion 36 is fitted into the fitting receiving portion 24 of the container body 2, the lower protrusion 36a and the fitting receiving portion 24 rub against each other and undergo elastic deformation. Furthermore, when the lower protrusion 36a passes the main body fitting wall portion 24b and reaches the recess of the lower recess portion 24a, the lower protrusion 36a fits into the recess provided on the inner circumferential surface of the lower recess portion 24a and comes into close contact with the inner circumferential surface Fa of the fitting receiving portion 24. In addition, the lower fitting wall portion 36b and the main body fitting wall portion 24b remain in close contact while in a state of elastic deformation.

[0043] As described above, the lower protrusion 36a and the fitting receiving portion 24 are in close contact with each other, while mutually repulsing each other through elastic deformation. Similarly, the lower fitting wall portion 36b and the main fitting wall portion 24b are in close contact with each other, while mutually repulsing each other through elastic deformation. As a result, the fitting strength between the interior fitting portion 36 and the fitting receiving portion 24 can be strengthened. Furthermore, the lower protrusion 36a and the lower fitting wall portion 36b ensure sealing performance by being in close contact with the inner circumferential surface Fa of the fitting receiving portion 24, and function as a lower sealing portion. Moreover, since the lower protrusion 36a fits into and engages with the lower recess portion 24a, it also provides a function to prevent it from coming loose.

[0044] The exterior fitting portion 37 comprises an upper fitting wall portion 37a positioned outwardly offset from the lower fitting wall portion 36b of the interior fitting portion 36, and an upper protrusion 37b connected to the upper part of the upper fitting wall portion 37a.

[0045] The upper fitting wall portion 37a is a cylindrical portion provided along the outer edge of the opening M of the container body 2. The upper protrusion 37b extends inward from the upper part of the upper fitting wall portion 37a at an angle and has a shape that is folded back midway. The bent top of the upper protrusion 37b is continuous in a closed annular shape in the circumferential direction along the outer edge of the opening M of the container body 2. In this embodiment, the upper fitting wall portion 37a and the upper protrusion 37b have substantially the same thickness.

[0046] The lid 4 comprises a lid fitting portion 45 and a flange portion 46 provided on the upper part of the lid fitting portion 45. The lid fitting portion 45 comprises a lower wall portion 45a connected to the periphery of the cover portion 41, an upper recess portion 45b connected to the upper part of the lower wall portion 45a, and an upper wall portion 45c connected to the upper part of the upper recess portion 45b. The flange portion 46 protrudes outward from the upper part of the upper wall portion 45c and is positioned by contacting the lid positioning portion 38 of the inner tray 3. The lid 4 is formed by bending a sheet material using a predetermined mold and has substantially the same thickness. The lid fitting portion 45 is formed with a flexible shape and thickness so that it can be slightly deformed by the elasticity inherent in the sheet material.

[0047] The lower wall portion 45a is a cylindrical portion provided along the outer edge of the opening M of the container body 2. The upper recess portion 45b comprises, for example, a lower inclined portion that bends inward from the lower wall portion 45a, an upright portion that rises from the lower inclined portion, and an upper inclined portion that bends outward from the upright portion. The upright portion is set back inward from the lower wall portion 45a, and as a result, an inward recess is formed on the outer circumferential surface of the upper recess portion 45b. The recess of the upper recess portion 45b is continuous in a closed annular shape in the circumferential direction along the outer edge of the opening M of the container body 2. Furthermore, the recess of the upper recess portion 45b has an area sufficient to accommodate the upper protrusion 37b of the inner tray 3 and the curved inner circumferential surface of the main body fitting wall portion 24b of the container body 2. In this embodiment, the lower wall portion 45a, the upper recess portion 45b, and the upper wall portion 45c have substantially the same thickness.

[0048] When fitting the lid fitting portion 45 into the outer fitting portion 37 of the inner plate fitting portion 35, the lower wall portion 45a of the lid fitting portion 45 and the upper protrusion 37b of the outer fitting portion 37 rub against each other and undergo elastic deformation. Furthermore, when the lower wall portion 45a passes the upper protrusion 37b and the upper protrusion 37b reaches the recess of the upper recess portion 45b, the upper protrusion 37b fits into the recess provided on the outer circumferential surface of the upper recess portion 45b and comes into close contact with the outer circumferential surface Fb of the lid fitting portion 45. In addition, the upper fitting wall portion 37a and the lower wall portion 45a of the outer fitting portion 37 remain in close contact while in a state of elastic deformation.

[0049] As described above, the lower wall portion 45a and the upper fitting wall portion 37a are in close contact with each other, while mutually applying repulsive force due to elastic deformation. As a result, the fitting strength between the exterior fitting portion 37 and the lid fitting portion 45 can be strengthened. In addition, the upper fitting wall portion 37a ensures sealing performance by being in close contact with the outer peripheral surface Fb of the lid fitting portion 45, and functions as an upper sealing portion. Furthermore, the upper protrusion 37b fits into the upper recess portion 45b, reinforcing the fitting of the upper fitting wall portion 37a to the lid fitting portion 45, and the upper protrusion 37b also functions as an anti-loosening mechanism as it fits into and engages with the upper recess portion 45b.

[0050] As shown in Figure 5, in this embodiment, the food packaging container 1 can also omit the inner tray 3 and have the lid 4 directly attached to the container body 2. In other words, the lid fitting portion 45 of the lid 4 can be fitted onto the inner circumferential surface Fa of the fitting receiving portion 24 of the container body 2. Here, the statement that the lid fitting portion 45 of the lid 4 can be fitted onto the inner circumferential surface Fa of the fitting receiving portion 24 of the container body 2 means that the outer diameter of the lid fitting portion 45 is greater than or equal to the inner diameter of the fitting receiving portion 24 of the container body 2, and that it has dimensions that allow for a tight fit when the lid fitting portion 45 is press-fitted into the fitting receiving portion 24 of the container body 2.

[0051] Here, the inner fitting portion 36 of the inner tray 3 (see Figure 4) can be fitted onto the inner circumferential surface Fa of the fitting receiving portion 24 of the container body 2, as described above. The outer fitting portion 37 is positioned offset outward from the inner fitting portion 36, so that it can be fitted onto the outer circumferential surface Fb of the lid fitting portion 45. In other words, there is a dimensional difference between the inner fitting portion 36 and the outer fitting portion 37, and a dimensional difference adjustment portion 5 is provided to bridge this dimensional difference and connect them. For example, the dimensional difference adjustment portion 5 is a portion that expands in diameter and protrudes outward from the upper part of the inner fitting portion 36, and in this embodiment, it protrudes outward at an angle from the upper part of the inner fitting portion 36 and is connected to the lower part of the outer fitting portion 37. Note that the dimensional difference adjustment portion 5 can be broadly applied in a form that expands in diameter and protrudes from the upper part of the inner fitting portion 36 and is connected to the lower part of the outer fitting portion 37, thereby bridging the dimensional difference between the inner fitting portion 36 and the outer fitting portion 37. For example, the dimensional difference adjustment section 5 may be a portion that protrudes outward from the upper part of the interior fitting section 36 without being inclined.

[0052] Next, referring to Figures 6 and 7, the usage of the food packaging container 1 according to this embodiment will be explained in comparison with the food packaging container 100 according to a comparative embodiment. Figure 6 is a schematic cross-sectional view of the food packaging container 1 according to this embodiment, where (a) shows the container with the inner tray 3 attached, and (b) shows the container without the inner tray 3. Figure 7 is a schematic cross-sectional view of the food packaging container 100 according to a comparative embodiment, where (a) shows the container with the inner tray 300 attached, and (b) shows the container without the inner tray 300.

[0053] As shown in Figure 7, in the case of the food packaging container 100 according to the comparative form, there is no dimensional difference adjustment part, and therefore the outer circumferential surface of the inner tray fitting part 350 is fitted into the fitting receiving part 240 of the container body 200, and the inner circumferential surface of the inner tray fitting part 350 is fitted into the lid fitting part 450. In the case of the food packaging container 100 according to the comparative form, the sealing performance inside the container body 200 is maintained when the inner tray 300 is attached. However, if the inner tray 300 is omitted and the lid 400 is to be attached directly to the container body 200, a gap will be created due to the thickness of the inner tray 300, making it difficult to ensure sealing performance.

[0054] On the other hand, in the case of the food packaging container 1 according to this embodiment, the sealing performance inside the container body 2 can be ensured regardless of whether the inner tray 3 is present or not. For example, as shown in Figure 6(a), when the inner tray 3 is installed, the inner tray 3 forms a lower space Sa and an upper space Sb inside the container body 2. Furthermore, in this state, the inner fitting portion 36 of the inner tray 3 fits into the fitting receiving portion 24 of the container body 2, ensuring sealing performance. As a result, the food etc. F contained in the lower space Sa is stably maintained without leaking out of the lower space Sa. Also, the outer fitting portion 37 of the inner tray 3 fits into the lid fitting portion 45, ensuring sealing performance. As a result, the food etc. F contained in the upper space Sb is stably maintained without leaking out of the upper space Sb.

[0055] In this embodiment of the food packaging container 1, the depth D1 of the upper space Sb is greater than the depth D2 of the lower space Sa, based on the height from the bottom 21 of the container body 2 to the cover portion 41 of the lid 4. As a result, when food or other items F are placed inside the container body 2, the upper space Sb can be effectively utilized.

[0056] Furthermore, as shown in Figure 6(b), if the inner tray 3 is omitted, the lid fitting portion 45 is directly fitted to the fitting receiving portion 24 of the container body 2. Since the lid fitting portion 45 has an outer diameter that allows it to be fitted to the inner circumferential surface Fa of the fitting receiving portion 24, even if the lid fitting portion 45 is directly fitted to the fitting receiving portion 24 of the container body 2, the outer circumferential surface Fb of the lid fitting portion 45 is in close contact with the inner circumferential surface Fa of the fitting receiving portion 24, which is advantageous for ensuring a seal. In particular, in this embodiment, the main body fitting wall portion 24b of the fitting receiving portion 24 has an inner circumferential surface that protrudes inward and curves, and this inner circumferential surface fits into the recess of the upper recess portion 45b of the lid fitting portion 45, making close contact and further engaging with it. Furthermore, the lower wall portion 45a of the lid fitting portion 45 protrudes outward relative to the upper recess portion 45b, and this protrusion fits tightly into the recess of the lower recess portion 24a of the fitting receiving portion 24, and is further engaged. The tight contact between the main body fitting wall portion 24b and the upper recess portion 45b, and the tight contact between the lower wall portion 45a and the lower recess portion 24a, is advantageous for improving the internal sealing performance. In addition, the engagement between the main body fitting wall portion 24b and the upper recess portion 45b, and the engagement between the lower wall portion 45a and the lower recess portion 24a, can prevent the lid 4 from unintentionally detaching from the container body 2.

[0057] Furthermore, as an example of how the food packaging container 1 is used, multiple inner trays 3 may be stacked vertically, and multiple spaces may be formed by the multiple inner trays 3.

[0058] Next, a food packaging container 1A according to another embodiment will be described with reference to Figures 8 and 9. Figure 8 is a cross-sectional view mainly showing the fitting structure of the food packaging container 1A according to another embodiment, and Figure 9 is a diagram illustrating the food packaging container 1A according to another embodiment in comparison with the embodiment described above. In Figure 9, (a) shows the embodiment described above, (b) shows the food packaging container 1A according to another embodiment, and (c) shows a modified example of the food packaging container 1A according to another embodiment. Note that the food packaging container 1A according to another embodiment has the same structure and configuration as the food packaging container 1 according to the embodiment described above. Therefore, in the following description, the differences will be the main focus, and detailed explanations of similar structures and configurations will be omitted.

[0059] In another embodiment, the food packaging container 1A is equipped with a dimensional difference adjustment section 5, and the dimensional difference adjustment section 5 is provided with an expansion wall section 6. The expansion wall section 6 is a cylindrical portion that extends in the height direction from which the exterior fitting section 37 is erected. Providing the expansion wall section 6 is advantageous for widening the upper space Sb. In this embodiment, the expansion wall section 6 is provided at the lower part of the dimensional difference adjustment section 5. Specifically, the expansion wall section 6 is erected so as to be flush and continuous with the lower fitting wall section 36b of the interior fitting section 36. The expansion wall section 6 can also be provided at the upper part of the dimensional difference adjustment section 5, for example, it may be provided so as to be flush and continuous below the upper fitting wall section 37a of the exterior fitting section 37. Alternatively, the expansion wall section 6 may be provided so as to be erected from an intermediate part between the lower and upper parts of the dimensional difference adjustment section 5.

[0060] Next, referring to Figure 9, a method for changing the internal volume by attaching different types of inner trays 3 will be described. Figure 9(a) shows a food packaging container 1 according to the above embodiment, which does not have an expanded wall portion 6. First, we consider the lower space Sa and upper space Sb of the food packaging container 1 shown in Figure 9(a) as reference.

[0061] Figure 9(b) shows a food packaging container 1A according to another embodiment, which includes an expandable wall portion 6. The inner tray 3A of the food packaging container 1A is the same as the inner tray 3 according to the above embodiment, except for the expandable wall portion 6. In the case of the food packaging container 1A, since it is equipped with an expandable wall portion 6, it is possible to increase the volume of the upper space Sb by the height dimension of the expandable wall portion 6.

[0062] Figure 9(c) shows a modified example of the food packaging container 1A. In the modified food packaging container 1A, the partition 31 of the inner tray 3A is raised to increase the volume of the lower space Sa, and the volume of the upper space Sb is further increased by increasing the height dimension of the expansion wall 6. In this way, by preparing an inner tray 3 without the expansion wall 6, an inner tray 3A with the expansion wall 6, and multiple inner trays 3A with expansion wall 6 of different heights, it becomes easier to appropriately expand the volume of the internal space of the food packaging container 1A, especially the volume of the upper space Sb.

[0063] Next, the operation and effects of the food packaging containers 1 and 1A according to each embodiment will be described. Each food packaging container 1 and 1A according to each embodiment is equipped with inner trays 3 and 3A. The inner fitting portion 36 of the inner tray 3 fits onto the inner circumferential surface Fa of the fitting receiving portion 24 of the container body 2, ensuring the sealing of the lower space Sa. The outer fitting portion 37 fits onto the outer circumferential surface Fb of the lid fitting portion 45 of the lid 4, ensuring the sealing of the upper space Sb. The lid fitting portion 45 of the lid 4 has an outer diameter dimension that allows it to fit onto the inner circumferential surface Fa of the fitting receiving portion 24. Therefore, when the inner trays 3 and 3A are not used, the lid fitting portion 45 of the lid 4 can be directly fitted onto the inner circumferential surface Fa of the fitting receiving portion 24 to ensure sealing. Here, the dimensional difference between the inner fitting portion 36 and the outer fitting portion 37 of the inner trays 3 and 3A is absorbed by the dimensional difference adjustment portion 5. Therefore, the inner trays 3 and 3A can be attached to the container body 2 without difficulty, and the lid 4 can also be attached to the inner trays 3 and 3A without difficulty. As a result, it is easier to ensure a seal while forming an upper space Sb and a lower space Sa inside with the inner trays 3 and 3A, and it is also easier to ensure a seal even when the lid 4 is attached directly to the container body 2 without using the inner tray 3.

[0064] Furthermore, in the food packaging containers 1,1A according to each embodiment, the lower protrusion 36a of the interior fitting portion 36 of the inner tray 3,3A abuts against and fits into the recess of the lower recess portion 24a of the container body 2, and the upper protrusion 37b of the exterior fitting portion 37 abuts against and fits into the recess of the upper recess portion 45b of the lid fitting portion 45. As a result, the engagement between the lower protrusion 36a of the interior fitting portion 36 and the lower recess portion 24a of the fitting receiving portion 24 prevents the inner tray 3 from unintentionally detaching from the container body 2. Also, the engagement between the upper protrusion 37b of the exterior fitting portion 37 and the upper recess portion 45b of the lid fitting portion 45 prevents the lid 4 from unintentionally detaching from the inner tray 3.

[0065] Furthermore, the lower protrusion 36a and lower fitting wall portion 36b of the interior fitting portion 36 of the inner tray 3 function as a lower sealing portion that is in close contact with the lower recess portion 24a in a closed annular continuous manner in the circumferential direction along the outer edge of the opening M. The function of the lower protrusion 36a and lower fitting wall portion 36b as a lower sealing portion is advantageous in improving the sealing performance of the lower space Sa.

[0066] Furthermore, the upper protrusion 37b and upper fitting wall portion 37a of the outer fitting portion 37 of the inner plate 3 function as an upper sealing portion that is in close contact with the upper recess portion 45b in a closed annular continuous manner along the outer edge of the opening M. The function of the upper protrusion 37b and upper fitting wall portion 37a as an upper sealing portion is advantageous in improving the sealing performance of the upper space Sb. [Explanation of symbols]

[0067] 1,1A...Food packaging container, 2...Container body, 3,3A...Inner tray, 4...Lid, 5...Dimensional difference adjustment part, 6...Expanded wall part, 21...Bottom part, 22...Surface wall, 24...Fitting receiving part, 31...Partition part, 36...Interior fitting part, 36a...Lower protrusion (lower seal part), 36b...Lower fitting wall part (lower seal part), 37...Exterior fitting part, 37a...Upper fitting wall part (upper seal part), 37b...Upper protrusion (upper seal part), 41...Cover part, 45...Lid fitting part, Fa...Inner surface of fitting receiving part, Fb...Outer surface of lid fitting part, M...Opening, Sa...Lower space, Sb...Upper space.

Claims

1. An inner tray for a packaging container, which is positioned between a container body and a lid that can be fitted onto the inner surface of the periphery of the container body, forming a lower space and an upper space inside the container body, and into which the lid is fitted. A partition separating the lower space and the upper space, An interior fitting portion is erected along the periphery of the partition portion and is capable of fitting onto the inner circumferential surface of the fitting receiving portion of the container body, An exterior fitting portion that can be fitted onto the outer circumferential surface of the lid fitting portion of the lid, It comprises a dimensional difference adjustment section that expands in diameter and protrudes from the upper part of the interior fitting section and is connected to the lower part of the exterior fitting section, The outer fitting portion comprises an upper fitting wall portion erected upward from the dimensional difference adjustment portion, and an upper protrusion that extends inward from the upper part of the upper fitting wall portion and is capable of fitting onto the outer circumferential surface of the lid fitting portion, in the middle plate.

2. The inner plate according to claim 1, wherein the dimension difference adjustment portion extends in the height direction in which the exterior fitting portion is erected, and further comprises an expanding wall portion that widens the upper space.

3. The inner tray according to claim 1 or 2, wherein the interior fitting portion has a lower protrusion that protrudes outward and is provided to fit into the recess of the fitting receiving portion.

4. The inner tray according to claim 3, wherein the interior fitting portion includes a lower sealing portion that is in close contact with the recessed portion in a closed, annular manner in the circumferential direction along the outer edge of the opening of the container body.

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