JP2023013231A - Container lid and vapor discharge method for container - Google Patents

Abstract

To provide a container lid capable of discharging vapor without getting off from a container when heat-cooking with an electronic oven or the like even using a structure with no holes.SOLUTION: A container lid includes: a top surface part 21 covering an opening part 11 of a container body 10 storing food products; and a lid edge part 22 fixed on a body edge part 14 of the container body 10 so as to be detachable. The top surface part 21 has a deformation part 21c urging local deformation by an internal pressure when heating. The lid edge part 22 has: an engagement part 23 engaged with the body edge part 14; and one or more vapor discharge parts 24 arranged while being sandwiched by the engagement part 23. The vapor discharge part 24 is projected more upward than the deformation part 21c. The vapor discharge part 24 is displaced upward accompanied with the deformation of the deformation part 21c, and has a partition part 24d including an opposing surface FA which opposes to an internal surface of the container body 10, ad abuts on the internal surface of the container body 10 to extend.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a container lid for storing food, a container, and a method for discharging steam from the container.

2. Description of the Related Art Some containers for storing food or the like have a function of exhausting steam generated during cooking with a microwave oven or the like. As a container that can exhaust steam, a steam hole such as a valve punched in a U-shape or C-shape on the top surface of the lid so that the lid does not pop off due to the internal pressure of the container and the decrease in rigidity of the container material during heating. (see, for example, Patent Document 1). In addition, there is a type in which side air is provided to facilitate exhaust by providing a projecting portion on the side wall of the lid (see, for example, Patent Document 2).

In addition, as another container that can exhaust steam, a concave portion or a curved portion is provided on the top surface of the lid, a slit or a notch (slit valve) is provided in the concave portion or the curved portion, and the slit valve is opened when the internal pressure of the container is applied by heating. Some have openings to exhaust steam (see, for example, Patent Documents 3 to 6). Further, as another container, a large number of pores formed by laser irradiation are provided, and vapor is exhausted from the pores (see, for example, Patent Document 7).

As in the containers of Patent Documents 1, 2, and 7, in a configuration in which exhaust ports such as steam vents, side air, and pores are provided, the size and number of the exhaust ports prevent entry of insects and contamination such as dust. Although a suppressing effect can be expected, these cannot be completely prevented. In addition, as in the containers of Patent Documents 3 to 6, in a configuration in which an exhaust port is provided by a slit valve, the slit valve is opened by the internal pressure of the container during heating when the exhaust port is closed, and the exhaust port is completely closed. If the closed state can be maintained, foreign matter can be prevented from entering, but it is not perfect because a gap is easily created by external pressure. In addition, there is a method for solving the above problems by attaching a low-adhesion label or a notched label to the steam vent or slit valve, but the problem is that the cost and the number of man-hours increase.

In addition, in order to prevent foreign matter from entering the container, a hole for steam discharge is not provided in the top surface of the lid as another container, and the lid flange softened by the steam generated by heating is released from the upper surface of the body flange. There are some that exhaust steam by surfacing (see, for example, Patent Document 8). Specifically, the container of Patent Document 8 has a plurality of communicating grooves that serve as steam passages on the outer surface of the lid inner fitting surface portion, and when the lid is closed, an annular downward groove provided on the lid flange portion. Only the ridge is in contact with the upper surface of the body flange portion. The container has an annular inner space formed by the lid flange portion, the body flange portion, and the downward ridge inside the downward ridge. At the time of heating, steam enters the groove for communication and fills the inner space. The filled steam heats the lid flange portion and softens the resin of the lid flange portion. Due to the softening of the resin, the lid flange easily floats upward, forming a gap between the downward ridge and the upper surface of the body flange, through which steam is exhausted to the outside.

In the case of the container of Patent Document 8, when the steam generated by a sudden increase in the internal pressure of the container due to heating by a high-power microwave oven or the like enters the groove for communication all at once, the steam leaks out all at once because the lid flange cannot rise in time. There is a risk.

As another container, a groove for discharging steam is formed in the outer circumference of the lid or in the fitting portion of the container body, and the closed groove is opened by pushing up the lid due to the increase in internal pressure of the container. There are some that exhaust steam from the part (see, for example, US Pat. The same problem as in Patent Document 8 may occur in the containers of Patent Documents 9 to 11 as well. Further, in the container of Patent Document 11, since the lid moves upward to form an exhaust portion, it cannot be used for shrink packaging or the like.

JP 2007-191161 A JP 2010-58809 A JP 2019-167158 A Registered Utility Model No. 3220615 JP 2019-81612 A JP 2019-147574 A JP 2018-20851 A Japanese Patent Application Laid-Open No. 2020-132240 JP-A-2001-80682 JP-A-10-316177 JP 2010-215259 A

The present invention has been made in view of the above background art, and the lid of a container that can discharge steam without coming off the container during cooking with a microwave oven or the like even if it has a structure that does not have a hole, and the lid. It is an object of the present invention to provide a method for venting steam from a container fitted with a

In order to achieve the above object, the lid for a container according to the present invention includes a top surface portion covering an opening of a container body containing food, and a lid edge portion detachably fixed to the body edge portion of the container body. A lid for a container, wherein the top surface portion has a deformation portion that promotes local deformation due to internal pressure during heating, and the lid edge portion is sandwiched between the fitting portion that fits into the body edge portion and the fitting portion. and one or more steam discharge portions arranged along the edge of the container body, the steam discharge portion protruding upward from the deformation portion, the steam discharge portion being displaced upward as the deformation portion deforms, and It has a partition that faces the inner surface and includes a facing surface that extends in contact with the inner surface of the container body.

According to the lid of the container, since the top surface portion has the deformable portion that can be deformed during heating, the internal pressure increase in the container during heating can be moderated. In addition, since the lid edge portion has the vapor discharge portion, and the vapor discharge portion has the partition portion, it is possible to suppress entry of foreign matter such as insects and dust. The steam exhaust portion opens as the deformable portion deforms and exhausts the steam.

In a specific aspect of the present invention, in the lid of the container, the steam discharge part includes an inner wall including a facing surface, an outer wall disposed on the opposite side of the inner wall across the body edge, and upper parts of the inner wall and the outer wall. and the top slopes upward from the inner wall to the outer wall. In this case, during heating, the fitting by the fitting portion is maintained, and the vapor discharge portion is deformed and displaced along with the deformation of the deformable portion, and the position of the vapor discharge portion in the outer edge portion of the container is for evacuation. Gaps are easily formed. As a result, the exhaust function can be maintained without removing the lid from the container even in the case of high-power, long-time cooking. In addition, the upward inclination of the vapor discharge portion can prevent deformation of the vapor discharge portion due to the shrink film in the container wrapped in the shrink film. That is, it prevents the shrink film or the like from obstructing the appearance of the steam exhaust port.

In another aspect of the invention, the inner wall extends against or is positioned adjacent to the inner surface of the container body, and the outer wall has a gap between it and the body edge. In this case, it is possible to easily form a gap between the steam discharge part and the container body during heating.

In still another aspect of the present invention, the partition has an exhaust port forming portion that is deformed in accordance with the deformation of the deformable portion. In this case, the exhaust port forming portion forms an exhaust port between the steam exhaust portion and the edge portion of the main body by deforming or displacing the steam exhaust portion due to the internal pressure and temperature rise of the container during heating. The exhaust port also appears when the lid is fixed with a shrink film, band label, or the like.

In yet another aspect of the invention, the facing surface is inclined with respect to the axis of symmetry of the container body. In this case, the displacement of the steam discharge portion can be promoted more, and the formation of the exhaust port or the gap is ensured.

In still another aspect of the present invention, in a cross-sectional view including the axis of symmetry of the container body, the top surface portion is inclined radially outward from the center toward the axis of symmetry of the container body, and then inclined upward. . In this case, when the top surface portion is deformed due to the increase in the internal pressure inside the container during heating, a partial increase occurs to widen the space, making it easier to store steam and further suppressing the increase in the internal pressure inside the container.

In still another aspect of the present invention, the top surface portion has a support portion closer to the center than the deformation portion, and the deformation portion extends from the outer edge of the support portion toward the lid edge portion in a cross-sectional view. It curves and inclines in the direction from the bottom to the top. In this case, by providing the support portion, it is possible to increase the inclination change of the entire top surface portion from the bottom to the top. can be done. Further, by providing the supporting portion, it is possible to prevent deformation of the steam discharge portion due to the shrink film in the container wrapped with the shrink film.

Moreover, in still another aspect of the present invention, the deformation portion is either a curved portion or a bent portion. In this case, the top surface can be easily deformed.

In order to achieve the above object, a method for discharging steam from a container according to the present invention includes: a container main body for containing food; a top surface portion covering an opening of the container main body; and a lid having a lid edge, wherein the top surface has a deformation portion that promotes local deformation due to internal pressure during heating, and the lid edge is attached to the main body edge. It has a fitting part to be fitted, and one or more steam discharge parts sandwiched between the fitting parts, the steam discharge part protruding upward from the deformation part, and the steam discharge part is connected to the deformation part. Displaced upward with the deformation of the container body, facing the inner surface of the container body, and having a partition portion including a facing surface extending in contact with the inner surface of the container body, and the partition portion is deformed with the deformation of the deformed portion during heating Steam is exhausted from the interior of the container by separating from the inner surface of the container body so that the steam can be discharged.

According to the method for discharging steam from a container, the top surface portion has a deformable portion that can be deformed during heating, so that the increase in internal pressure inside the container during heating can be moderated. In addition, since the lid edge portion has the steam discharge portion and the steam discharge portion has the partition portion, it is possible to prevent foreign matter such as insects and dust from entering before heating.

(A) and (B) are a conceptual plan view and a front view explaining the container according to the embodiment. (A) is a cross-sectional view of the container shown in FIG. 1(A), (B) is a cross-sectional view of the lid of the container, and (C) is a cross-sectional view of the container main body. (A) to (D) are conceptual partial enlarged cross-sectional views for explaining the lid of the container shown in FIG. 1 is a cross-sectional view along -B, (C) is a cross-sectional view along CC, and (D) is a cross-sectional view along DD. (A) is a diagram in which cross-sectional views of the lids shown in FIGS. 3A to 3C are superimposed, (B) is a conceptual cross-sectional view of the container during heating, ) is a partial enlarged view including a vapor discharge portion of the lid of the side surface of the container, and (D) is an enlarged cross-sectional view of the vapor discharge portion. It is a conceptual diagram explaining the example which stacks a container. (A) is a conceptual diagram showing the state of the container before cooking, and (B) is a conceptual diagram showing the state of the container during cooking. (A) and (B) are cross-sectional views illustrating the fitting portion of the lid. 1(A) to 1(C) are diagrams for explaining modifications of the lid of the container shown in FIG. 1(A).

[Embodiment]
Hereinafter, a container 100 having a lid 20 according to the present invention will be described with reference to FIG. 1(A) and the like. The container 100 accommodates food or ingredients. The container 100 can be used for heating and cooking food contained in the container body 10 with the lid 20 closed, that is, with the lid closed, using a microwave oven or the like.

As shown in FIGS. 1A, 1B, and 2A, the container 100 includes a container body 10 and a lid 20. As shown in FIGS. 1(B) and 2(A) show a state in which the entire container 100 is wrapped with a shrink film 30. FIG. The container 100 has various shapes such as a circle, an ellipse, a rectangle, and a polygon in plan view. A container 100 such as FIG. 1A shows an example having a circular outer shape in plan view. Although illustration is omitted, when the shape of the container 100 is rectangular or polygonal, the sides of the container 100 may be linear or curved. When the shape of the container 100 is rectangular or polygonal, the corners of the container 100 are preferably rounded. An example in which the container 100 is circular in plan view will be described below.

As shown in FIGS. 1(A), 1(B), 2(A), and 2(C), the container body 10 is a bowl-shaped vessel having an opening 11 on the upper side, and a bottom portion 12 and a , a body side portion 13 and a body edge portion 14 . The bottom portion 12 has a substantially circular shape in plan view. A leg portion 15 is provided on the lower portion of the bottom portion 12 . Note that the leg portion 15 may be omitted. Main body side surface portion 13 is cylindrical, and more specifically, has a tapered shape extending upward from peripheral edge 12 a of bottom surface portion 12 . The main body edge portion 14 is provided so as to protrude outside the upper end 13 a of the main body side portion 13 . The body edge portion 14 is provided around the entire circumference of the opening 11 of the container body 10 . The main body edge portion 14 and a fitting portion 23 of the lid edge portion 22 described later can be fitted. The body edge portion 14 may be formed by curling the peripheral edge of the container body 10, or may be formed as a projection. The container body 10 is made of paper, resin, or the like. The material of the container body 10 has heat resistance that can withstand heating by a microwave oven. Examples of resins include polypropylene, polyethylene, polyester, and polystyrene.

As shown in FIGS. 1(A), 1(B), 2(A), and 2(B), the lid 20 has a top surface portion 21 and a lid edge portion 22 . The lid 20 corresponds to the shape of the container body 10 and can be fitted to the container body 10 .

The lid 20 is made of paper, resin, or the like. The material of the lid 20 has heat resistance to withstand heating by a microwave oven. Examples of resins include polypropylene, polyethylene, polyester, and polystyrene. Further, the lid 20 has such a thickness that it can be deformed by the internal pressure and heat of the container 100 during heating or cooking. The lid 20 is formed by, for example, vacuum forming, pressure forming, or the like.

The top surface portion 21 covers the opening portion 11 of the container body 10 . The top surface portion 21 has a substantially circular shape in plan view.

3(A) to 3(D) are conceptual partial enlarged cross-sectional views for explaining the lid 20 shown in FIG. 1(A) and the like. 3A is a cross-sectional view along AA of FIG. 1A, FIG. 3B is a cross-sectional view along B-B, and FIG. 3C is a cross-sectional view along CC. , and FIG. 3D is a cross-sectional view taken along line DD. FIG. 4A is a diagram showing the cross-sectional views of the lid 20 shown in FIGS. 3A to 3C superimposed, and FIG. It is a diagram. 4C is a partially enlarged view of the side surface of the container 100 including the steam discharge portion 24 of the lid 20. FIG. 4D is an enlarged cross-sectional view of the steam discharge portion 24. As shown in FIG. As shown in FIG. 3A and the like, the top surface portion 21 includes a flat portion 21a, a support portion 21b, and a deformation portion 21c in this order radially outward from the center passing through the axis of symmetry OA of the container body 10 or the center. and

The flat portion 21a has a substantially circular shape in plan view and is arranged around the axis of symmetry OA. The support portion 21b protrudes upward in the direction of the axis of symmetry OA relative to the flat portion 21a and the deformation portion 21c. Correspondingly, the support portion 21b has a cylindrical surface, an annular flat surface, and a tapered surface. The support portion 21b supports the shrink film 30 to prevent deformation of the steam discharge portion 24, which will be described later, from being suppressed by the film, and can reliably develop the exhaust port 24e. In addition, the support portion 21b can support another lid 20 when stacking another lid 20 . As shown in FIG. 3D, the support portion 21b has a concave portion C for preventing the lids 20 from overlapping each other and being difficult to peel off when other lids 20 are stacked.

The deformation portion 21c extends radially outward from the outer edge of the support portion 21b. The deformation portion 21c promotes local deformation of the lid 20 by the internal pressure of the container 100 during heating. The deformation portion 21c is a curved portion BE having a curved surface. The curved portion BE can facilitate deformation of the top surface portion 21 . In a cross-sectional view including the axis of symmetry OA, the deformable portion 21c is curved and inclined in a direction from below the axis of symmetry OA toward the lid edge portion 22 located radially outward from the outer edge of the support portion 21b. In the illustrated example, the deformed portion 21c is recessed downward at the portion of the step 21d provided on the inner side, and curves upward from the step 21d toward the outside. When viewed as a whole together with the support portion 21b, the top surface portion 21 is inclined radially outward from the center downward about the axis of symmetry OA and then inclined upward. Since the top surface portion 21 has the above-described inclination, the deformation of the top surface portion 21 due to the increase in the internal pressure inside the container 100 during heating causes a partial rise, widening the space, making it easier for steam to accumulate, and increasing the temperature inside the container 100. It is possible to further suppress the increase in internal pressure. In particular, by providing the support portion 21b, it is possible to increase the inclination change of the entire top surface portion 21 from the bottom to the top. can be extended to

The top surface portion 21 has stoppers ST1 and ST2 that allow the containers 100 to be stacked. The outer stopper ST1 is formed by a step 21d provided in the deformation portion 21c. The inner stopper ST2 is formed by the boundary between the support portion 21b and the deformation portion 21c. FIG. 5 is a diagram illustrating an example in which the containers 100 are stacked on the lid 20. As shown in FIG. As shown in FIG. 5, when the containers 100 are the containers 101 and 102 of the first and second container standards, the lateral movement of the container 100 placed on the top of the lid 20 is suppressed by the stopper ST1. do. When the container 100 is the container 103 of the third container standard, the lateral movement of the container 100 placed on the top of the lid 20 is suppressed by the stopper ST2.

Returning to FIG. 2A and the like, the lid edge portion 22 is detachably fixed to the body edge portion 14 of the container body 10 . The lid edge portion 22 has a cylindrical shape, and extends downward from the peripheral edge 21 e of the top surface portion 21 while covering the main body edge portion 14 . The lid edge portion 22 is a fitting portion 23 (see FIGS. 3(B) to 3(D)) that fits into the body edge portion 14 of the container body 10, and one that is sandwiched between the fitting portion 23. It has the above steam exhaust part 24 (see FIG. 3(A)). In the example of FIG. 1(A), two vapor discharge portions 24 are provided on a straight line perpendicular to the axis of symmetry OA. The steam discharge portion 24 is provided in the outer peripheral region of the lid edge portion 22 over a range of 5% to 30%, preferably 10% to 20% of the entire circumference. In addition, the lid edge portion 22 has a flat brim-shaped outer edge portion 25 extending substantially horizontally from the fitting portion 23 or the steam discharge portion 24 on the entire periphery of the outermost edge. Although illustration is omitted, the outer edge portion 25 may be formed with a plurality of unevenness in order to reduce the sharpness of the edge portion.

As shown in FIGS. 3(B), 3(C), 4(A), and 4(C), etc., the fitting portion 23 has an annular portion 23a at its upper portion and a first groove portion 23b at its intermediate portion. and a second groove portion 23c, and a bottom portion 23d.

The annular portion 23a has a shape that substantially conforms to the inner surface of the container body 10, specifically, the shape of the upper end inner wall of the body side surface portion 13 of the container body 10 and the shape of the upper portion of the body edge portion 14. 22 (specifically, a region excluding a portion corresponding to the steam discharge portion 24). The annular portion 23a is formed slightly smaller than the width (horizontal or lateral length) of the main body edge portion 14, and is fitted by deforming the main body edge portion 14. As shown in FIG. The skirt portion 23d extends outwardly from the first and second groove portions 23b and 23c to the outer edge portion 25 while curving.

The first and second grooves 23b and 23c are annular grooves extending downward from the annular portion 23a as a whole and partially narrowed in radius at the intermediate portion of the lid edge portion 22. They are formed alternately over substantially the entire circumference. The first groove portion 23b and the second groove portion 23c are fitted with the body edge portion 14 at the lower portion of the body edge portion 14 . The cross-sectional shape including the axis of symmetry OA of the first and second grooves 23b and 23c may be an angular U-shape or an arc shape. The first groove portion 23b is formed shallower than the second groove portion 23c and fits relatively loosely with the container body 10 . As a result, the lid 20 can be moderately easily removed from the container body 10 . The second groove portion 23c is formed deeper than the first groove portion 23b, and fits relatively tightly with the container body 10. As shown in FIG. This makes it difficult for the lid 20 to come off the container body 10 during cooking. The arrangement, size, and shape of the first and second grooves 23b and 23c take into consideration the fitted state of the lid 20 before and after heating, which facilitates fitting and prevents the lid 20 from coming off during heating. It is a condition. Even if the steam during heating and the deformation of the deformable portion 21c cause the steam to be discharged, the fitting portion 23 fits the lid 20 to the container body 10, so the lid 20 is kept from the container body 10. never come off. By appropriately setting the inclination angles and lengths of the upper sides of the first and second grooves 23b and 23c, the fitting portion 23 is prevented from coming off even when the deformation portion 21c is deformed or the exhaust port 24e appears.

As shown in FIGS. 3(A), 4(A), 4(C), and 4(D), etc., the steam discharge portion 24 protrudes upward from the deformable portion 21c, and expands as the deformable portion 21c deforms. is displaced upwards. The steam discharge portion 24 is arranged on the opposite side of the inner wall 24a including the facing surface FA that faces the inner surface of the container body 10 and extends in contact with the inner surface of the container body 10, and the inner wall 24a with the body edge portion 14 interposed therebetween. It has an outer wall 24b and a top portion 24c connecting upper portions of the inner wall 24a and the outer wall 24b.

The inner wall 24a extends against or is positioned adjacent to the inner surface of the container body 10 and the outer wall 24b has a gap between it and the body edge 14 . This makes it easier to form a gap between the steam discharge part 24 and the container body 10 during heating. The top portion 24c slopes upward from the inner wall 24a toward the outer wall 24b in a cross-sectional view. At the time of heating, while the fitting by the fitting portion 23 is maintained, the vapor discharge portion 24 is deformed and displaced along with the deformation of the deformable portion 21c, and the exhaust is discharged at the position of the vapor discharge portion 24 in the outer edge portion of the container 100. It becomes easy to form a gap for As a result, the exhaust function can be maintained without removing the lid 20 from the container 100 even in the case of high-power, long-time cooking. In addition, due to the upward inclination of the steam discharge portion 24 , deformation suppression of the steam discharge portion 24 by the shrink film 30 can be prevented in the container 100 wrapped with the shrink film 30 .

The steam discharge portion 24 has a partition portion 24 d that faces the inner surface of the container body 10 and includes a facing surface FA that extends in contact with the inner surface of the container body 10 . The facing surface FA is desirably inclined with respect to the axis of symmetry OA of the container body 10 . Specifically, the facing surface FA extends so as to expand upward from the axis of symmetry OA. As a result, the displacement of the steam discharge portion 24 can be further promoted, and the formation of the exhaust port 24e or the gap is ensured. The partition part 24d is a part or the whole of the inner wall 24a, and locally partitions the inside and the outside of the container 100 by using the upper and lower steps inside the steam discharge part 24. As shown in FIG. The partition portion 24d abuts along the inner surface of the container body 10, specifically, the inner wall of the upper end of the side surface portion 13 of the container body 10 or the inner wall of the edge portion 14 of the container body 10. As shown in FIG. Since the partition part 24d has a shape in contact with the inner wall of the container body 10, it is possible to prevent foreign substances such as insects and dust from entering. The partition part 24d only needs to be in contact with the container body 10 to the extent that foreign matter is prevented from entering. A fitting portion 23 prevents foreign matter such as insects and dust from entering a portion of the lid edge portion 22 where the vapor discharge portion 24 is not provided. The height H of the partition 24d is, for example, 1 mm. As shown in FIG. 4B, the partition portion 24d of the steam discharge portion 24 has an exhaust port forming portion VE that is deformed with the deformation of the deformation portion 21c. As a result, the exhaust port forming portion VE forms an exhaust port 24e between the steam exhaust portion 24 and the body edge portion 14 by deforming or displacing the steam exhaust portion 24 due to the internal pressure and temperature rise of the container 100 during heating. do. The exhaust port 24e also appears when the lid 20 is fixed with the shrink film 30, band label, or the like.

Hereinafter, changes in the state of the lid 20 due to cooking will be described with reference to FIGS. 6(A) and 6(B).

As shown in FIG. 6A , in the container 100 before cooking, the partition 24 d of the steam discharge portion 24 of the lid 20 is in contact with the upper end inner wall of the main body side portion 13 of the container main body 10 . In other words, the inner wall 24a of the steam discharge portion 24 abuts on the upper end inner wall of the main body side portion 13 of the container main body 10 . In the portion of the lid edge portion 22 where the steam discharge portion 24 is provided, the partition portion 24d prevents foreign matter from entering the interior of the container 100. As shown in FIG. Also, in the lid edge portion 22 , the fitting portion 23 prevents foreign matter from entering the portion where the vapor discharge portion 24 is not provided.

As shown in FIG. 6B, when the internal pressure of the container 100 rises during cooking with a microwave oven or the like, the deformation portion 21c of the top surface portion 21 expands upward due to the increase in pressure and the softening of the lid 20. . Along with this deformation, the partition portion 24d of the steam discharge portion 24 moves or deforms above the container 100, so that the exhaust port forming portion VE of the steam discharge portion 24 forms an exhaust port 24e. After that, the steam is exhausted from the exhaust port 24e. According to the steam discharge method of the container 100 described above, the partition part 24d of the steam discharge part 24 is separated from the inner surface of the container body 10 so that the steam can be discharged as the deformable part 21c is deformed during heating, whereby the steam is discharged from the inside of the container 100. be done. Although not shown, after cooking, the lid 20 returns to its original state or a shape close to its original state due to the reduction in the internal pressure of the container 100 .

(Example)
Examples of the present embodiment will be described below. 7A and 7B are diagrams for explaining the shape and dimensions of the fitting portion 23 of the lid edge portion 22. FIG. In FIGS. 7(A) and 7(B), reference character X1 is the diameter of the fitting portion 23 of the lid 20, and reference character X2 is the radial length (groove depth) of the first groove portion 23b. and X3 is the radial length (groove depth) of the second groove portion 23c. Symbol θ1 is the upper inclination angle when the first and second grooves 23b and 23c are U-shaped, and symbol θ2 is the lower inclination angle.

The dimensions, shapes, and evaluation of the state after heating of the samples used in the examples are shown below. "Fitted/opened" indicates the fitted state of the lid 20 before heating. "Oven Rating" indicates the fit of the lid after heating in a microwave oven. In the "range evaluation", 100 g or 300 g of water was placed in the sample container 100, and the fitted state of the lid 20 was evaluated after heating at 1520 W for 90 minutes.

(Sample 1)
Fitting diameter X1: 141.2 mm
Shape of first and second grooves: U-shape (see FIG. 7(A))
Length X2 of the first groove: 0.4 mm
Second groove length X3: 0.4 mm
Upper tilt angle θ1: 30°
Lower tilt angle θ2: 45°
Fitting/unsealing: Relatively good Range evaluation: No lid coming off (Sample 2)
Fitting diameter X1: 140.9mm
Shape of first and second grooves: U-shape (see FIG. 7(A))
Length X2 of the first groove: 0.4 mm
Second groove length X3: 0.5 mm
Upper tilt angle θ1: 30°
Lower tilt angle θ2: 45°
Fitting/unsealing: Relatively difficult to fit Range evaluation: No lid coming off (Sample 3)
Fitting diameter X1: 141.2mm
Shape of first and second grooves: U-shape (see FIG. 7(A))
Length X2 of the first groove: 0.4 mm
Second groove length X3: 0.4 mm
Upper tilt angle θ1: 45°
Lower tilt angle θ2: 45°
Fitting/unsealing: Relatively good Range evaluation: Occurrence of lid detachment (Sample 4)
Fitting diameter X1: 141.2mm
Shape of first and second grooves: Arc shape (see FIG. 7(B))
Length X2 of the first groove: 0.5 mm
Second groove length X3: 0.4 mm
Mating/unsealing: Good range evaluation: Lid detachment occurs

As can be seen from Samples 1 to 3, the smaller the inclination angle of the upper side of the first and second grooves 23b and 23c and the larger the groove length, the harder it is for the lid 20 to come off after heating. Moreover, as can be seen from Samples 1 and 4, regarding the shape of the first and second grooves 23b and 23c, the U-shape makes it more difficult for the cover 20 to come off after heating than the arc shape.

According to the lid 20 of the container 100 described above, the top surface portion 21 has the deformable portion 21c that can be deformed during heating, so that the increase in the internal pressure inside the container 100 during heating can be moderated. In addition, since the lid edge portion 22 has the vapor discharge portion 24 and the inner wall 24a of the vapor discharge portion 24 has the partition portion 24d, it is possible to suppress the entry of foreign substances such as insects and dust. The steam exhaust portion 24 opens as the deformation portion 21c deforms and exhausts the steam.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various modifications are possible.

For example, the shape of the container body 10 and the shape of the lid 20 can be changed as appropriate within the scope of the present embodiment. As shown in FIG. 8A, a step 21d may be provided only in an extension region corresponding to the steam discharge portion 24 in the deformed portion 21c of the top surface portion 21. As shown in FIG. As shown in FIG. 8B, a configuration in which the support portion 21b is not provided on the top surface portion 21 may be employed. As shown in FIG. 8C, the top surface portion 21 may be configured so that the step 21d between the support portion 21b and the deformation portion 21c is not provided.

In the above-described embodiment, the deformed portion 21c is the curved portion BE, but it may be a bent portion whose cross-sectional view is angular rather than curved.

In the above-described embodiment, the container 100 is not limited to a rectangular shape in plan view, and can be various polygonal shapes. Alternatively, the container 100 may be oval.

In the above-described embodiment, an example in which two steam discharge portions 24 are provided was given, but one or three or more may be provided to the extent that the fitting function of the lid 20 is maintained.

In the above-described embodiment, the fitting portion 23 is not limited to having the inner wall including the facing surface facing the inner surface of the container body 10 along the inner surface of the container body 10 . There may be gaps between

In the above embodiment, the facing surface FA depends on the shape of the inner surface of the container body 10 and may be parallel to the sloping seams with respect to the axis of symmetry OA of the container body 10 .

In the above embodiment, the top portion 24c of the steam discharge portion 24 has a shape that slopes upward from the inner wall 24a toward the outer wall 24b. or a non-inclined shape.

DESCRIPTION OF SYMBOLS 10... Container main body 11... Opening part 12... Bottom part 12a... Peripheral edge 13... Body side part 13a... Upper end 14... Body edge part 15... Leg part 20... Lid 21... Top surface part 21a Flat portion 21b Support portion 21c Deformation portion 21d Step 21e Peripheral edge 22 Cover edge 23 Fitting portion 23a Annular portion 23b First groove 23c Second groove , 23d... skirt 24... steam discharge part 24a... inner wall 24b... outer wall 24c... top 24d... partition 24e... exhaust port 25... outer edge 30... shrink film 100... container BE... Curved portion C... Concave portion FA... Opposite surface OA... Symmetrical axis ST1, ST2... Stopper VE... Exhaust port forming part

Claims (9)

A lid for a container comprising a top surface portion covering an opening of a container body containing food, and a lid edge portion detachably fixed to the body edge portion of the container body,
The top surface portion has a deformation portion that promotes local deformation due to internal pressure during heating,
The lid edge portion has a fitting portion that fits into the body edge portion, and one or more steam discharge portions sandwiched between the fitting portions,
The steam discharge portion protrudes upward from the deformation portion,
The lid of the container, wherein the steam discharge part is displaced upward as the deformation part deforms, and has a partition part including a facing surface that faces the inner surface of the container body and extends in contact with the inner surface of the container body. The steam discharge part has an inner wall including the facing surface, an outer wall disposed on the opposite side of the inner wall across the main body edge, and a top connecting the upper part of the inner wall and the outer wall,
2. A container closure according to claim 1, wherein the top slopes upwardly from the inner wall toward the outer wall. 3. A container according to any one of claims 1 and 2, wherein the inner wall extends against or is positioned adjacent to the inner surface of the container body and the outer wall has a gap between it and the body edge. lid. The container lid according to any one of claims 1 to 3, wherein the partition part has an exhaust port forming part that is deformed as the deformation part deforms. The container lid according to any one of claims 1 to 4, wherein the facing surface is inclined with respect to the axis of symmetry of the container body. 6. The top panel according to any one of claims 1 to 5, wherein, in a cross-sectional view including the axis of symmetry of the container body, the top surface portion is inclined radially outwardly from the center downward of the axis of symmetry of the container body, and then inclined upward. or the lid of the container according to item 1. The top surface portion has a support portion closer to the center than the deformation portion,
7. The container lid according to claim 6, wherein said deformable portion is curved and inclined from the outer edge of said support portion toward the lid edge portion in a direction from below to above said axis of symmetry in said cross-sectional view. The lid for a container according to any one of claims 1 to 7, wherein the deformation portion is either a curved portion or a bent portion. A method for discharging steam from a container comprising: a container body containing food; a lid having a top surface covering an opening of the container body; and a lid edge detachably fixed to the body edge of the container body. and
The top surface portion has a deformation portion that promotes local deformation due to internal pressure during heating,
The lid edge portion has a fitting portion that fits into the body edge portion, and one or more steam discharge portions sandwiched between the fitting portions,
The steam discharge portion protrudes upward from the deformation portion,
the steam discharge portion includes a partition portion including a facing surface that is displaced upward as the deformation portion deforms, faces the inner surface of the container body, and extends in contact with the inner surface of the container body;
A steam discharging method for a container, wherein steam is discharged from the inside of the container by moving the partition part away from the inner surface of the container body so that the steam can be discharged as the deformation part is deformed during heating.

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