JP6436822B2 - Insulated container - Google Patents

Description

  The present invention relates to an insulated container.

  Conventionally, heat-insulated containers have been widely used for packing foods that require a certain temperature control. The heat insulating container protects the contents such as food contained in the container from the external environment at a temperature higher or lower than that inside the container by blocking heat transfer between the inside of the container and the external environment as much as possible. As an example of a heat insulating container, a container main body with an open upper surface, a lid that closes the upper surface opening of the container main body, and a lid that houses a flat rectangular parallelepiped cold storage material or heat storage material on the lower surface of the lid A container having a lower surface accommodating portion is known (see Patent Document 1 below).

  Referring to FIG. 3 of Patent Document 1, a first step portion (11E) is formed on the inner surface of the container body (11) over the entire opening edge of the upper surface opening (11K). The pair of short side walls (12, 12) is formed with a second stepped portion (11F) inside the first stepped portion (11E) to form a two-step staircase. Therefore, on the upper side of the first step portion (11E) of the container body (11), the thickness of the short side wall (12) is thinner than the thickness of the long side wall (13).

  However, the thickness of the short side wall (12) of the container body (11) is thicker than the thickness of the long side wall (13) on the lower side of the first step portion (11E) adjacent to the internal space. There are many cases. One reason for this is that the short side wall (12) of the container body (11) is provided with a concave manual feed portion (12H) for carrying the container (10). ) Is required to ensure mechanical strength by increasing the thickness.

JP 2014-231919 A

In the container (10) described in Patent Document 1, when the thickness of the short side wall (12) is relatively large and the thickness of the long side wall (13) is relatively thin, the long side wall ( The heat transmissivity (W / m ² K) of 13) is higher than the heat transmissivity of the short side wall (12). The area of the outer surface of the long side wall (13) is larger than the area of the outer surface of the short side wall (12). Therefore, the amount of heat entering and exiting the container (10) through the long side wall (13), that is, the amount of heat transferred to the long side wall (13) is the amount of heat entering and exiting the container (10) through the short side wall (12), That is, it becomes larger than the heat transfer amount of the short side wall (12). As a result, the internal temperature of the container (10) fluctuates relatively greatly in the vicinity of the long side wall (13), the internal temperature of the container (10) becomes non-uniform, and the contents of the container (10) such as food are changed. There is a risk of adverse effects.

  The present invention has been made in view of the above problems, and aims to more effectively protect contents such as food from temperature changes in the external environment by making the internal temperature of the heat insulating container uniform than before. To do.

  In order to achieve the above object, a heat-insulated container of the present invention comprises a container body having a bottom wall and a plurality of side walls, the upper part of which is open, and a lid that closes the upper opening of the container body. And each said side wall is each set to the thickness from which the difference of the heat transfer amount concerning the said side wall and the heat transfer amount concerning the said other side wall becomes 10% or less, It is characterized by the above-mentioned. Here, the heat transfer amount applied to the side wall is the amount of heat that enters the inside of the container body or is released to the outside of the container body through the side wall.

  When the insulated container of the present invention is used as a cold storage container, it is usually required to maintain the temperature inside the container body at a temperature lower than the temperature of the external environment. In this case, heat enters the inside of the container main body containing the contents such as food from the outside of the container main body through the respective side walls. On the other hand, when the heat insulating container of the present invention is used as a heat retaining container, it is usually required to maintain the temperature inside the container body at a temperature higher than the temperature of the external environment. In this case, heat is released from the inside of the container body to the outside of the container body through the respective side walls.

  In a heat insulating container, if the difference in the amount of heat transfer between each side wall and the other side wall exceeds 10%, the temperature balance inside the container body is broken and the temperature inside the container becomes non-uniform. As a result, the container There is a risk of adversely affecting the food inside. That is, in the vicinity of the side wall where the amount of heat transfer is relatively large and the amount of heat entering the inside of the container body or being released to the outside of the container body is large, the internal temperature of the container body is affected by the temperature difference from the temperature of the external environment. It becomes easy to fluctuate in response.

  On the other hand, in the vicinity of the side wall where the amount of heat transfer is relatively small and the amount of heat that penetrates into the container body or is released to the outside of the container body is small, the internal temperature of the container body is affected by the temperature difference from the temperature of the external environment. It becomes difficult and stable. Therefore, if the difference in the amount of heat transfer between each side wall and the other side wall exceeds 10%, the temperature difference due to the position inside the container main body will appear remarkably, the internal temperature of the heat insulating container will become uneven, There is a possibility that the influence on the contents cannot be ignored.

  Therefore, each side wall of the container main body included in the heat insulating container of the present invention is set to a thickness such that the difference in heat transfer amount with the other side wall is 10% or less of the heat transfer amount of the other side wall. Thereby, the temperature change characteristic (movement of heat quantity) in the vicinity of each side wall is made uniform inside the container body, and as a result, the internal temperature of the heat insulating container is made uniform. Therefore, according to the heat insulating container of the present invention, it is possible to protect the contents such as foods more effectively from the temperature change of the external environment by making the internal temperature uniform than the conventional heat insulating container.

  In addition, each side wall of the container body has a thickness in which the difference in heat transfer amount from the other side wall is smaller than 10% of the heat transfer amount of the other side wall, for example, 5% or less, 3% or less, 1% More preferably, the thickness is as follows. Moreover, it is more preferable that each side wall of the container main body is set to a thickness at which the heat transfer amount is equal to the heat transfer amount of the other side walls. Thereby, the temperature change characteristic in the vicinity of each side wall is made more uniform inside the container body, and as a result, the internal temperature of the heat insulation container is made more uniform.

  In the heat insulating container of the present invention, the plurality of side walls may include a narrow short side wall and a wide long side wall. That is, the heat insulating container of the present invention has a regular polygonal shape such as a square in a plan view perpendicular to the bottom wall of the container body, and all the side walls may have the same width. For example, it may have a polygonal shape with different side lengths, such as a rectangle, and may have a plurality of side walls with different widths. Thereby, it becomes possible to design the shape of a heat insulation container freely by the shape and use of the contents. Here, the width of the side wall means the dimension of the side wall in the direction parallel to the bottom wall of the container body and perpendicular to the thickness direction of the side wall, that is, the dimension of each side wall along each side of the bottom wall of the container body. . The vertical here can include not only perfect vertical but also an inclination of about 0.5 ° to 5 °.

  Moreover, the heat insulation container of this invention WHEREIN: It is preferable that the thickness of the said long side wall is thicker than the thickness of the said short side wall. Thereby, in a container main body, the difference between the heat transfer amount by a long side wall with a relatively large area and the heat transfer amount by a short side wall with a relatively small area can be reduced. Therefore, the internal temperature of the heat insulating container can be made more uniform, and contents such as food can be more effectively protected from temperature changes in the external environment.

  Moreover, the heat insulation container of this invention WHEREIN: It is preferable that the thickness of the said bottom wall is thicker than the thickness of the said long side wall. The bottom wall of the container main body may be disposed in contact with or adjacent to a road surface, floor surface, cargo bed, carriage, etc., which is higher or lower than the temperature around the heat insulating container, for example, when the heat insulating container is transported. . In such a case, by making the bottom wall thicker than the long side wall, the amount of heat that enters the inside of the heat insulating container through the bottom wall or is released to the outside of the heat insulating container is reduced, and By making the internal temperature of the container more uniform, contents such as food can be more effectively protected from temperature changes in the external environment. Moreover, the intensity | strength of the bottom wall of a container main body can be improved and durability of a heat insulation container can be improved.

  Moreover, the heat insulation container of this invention WHEREIN: The thickness of the said cover body may be thicker than the thickness of the said long side wall. As a result, when the heat insulating container of the present invention is used as, for example, a heat insulating container, air having a relatively high temperature stays above the inside of the container, and the temperature difference between the inside and outside of the lid body is between the inside and outside of the long side wall. Even when the temperature difference becomes larger, the amount of heat released from the inside of the container body to the outside through the lid can be reduced.

  Further, in the heat insulating container of the present invention, a regenerator material may be disposed on the upper part of the container body so as to face the lower surface of the lid, and the thickness of the lid is thinner than the thickness of the long side wall. May be. Thereby, the cold air cooled by the cool storage material can be lowered from the upper side to the lower side inside the container main body, and the cooling effect inside the container main body can be improved. In addition, since the cold storage material can absorb the heat that enters the inside of the heat insulating container from the outside of the heat insulating container through the cover, the thickness of the cover is reduced to reduce the size and weight of the heat insulating container and reduce the cost. Can do.

  Further, in the heat insulating container of the present invention, the heat transfer amount Q of the side wall is as follows: K is the thermal conductivity of the side wall, A is the area of the outer surface of the side wall, ΔT is the temperature difference between the inside and the outside of the container body. Assuming that time is H, the film coefficient of the inner surface of the side wall is α1, the film coefficient of the outer surface of the side wall is α2, the thickness of the side wall is d, and the thermal conductivity of the side wall is λ, the following formula ( 1) and (2).

Q = K · A · ΔT · H (1)
K = 1 / (1 / α1 + d / λ + 1 / α2) (2)

  Based on the formulas (1) and (2), in the heat insulating container of the present invention, the difference in the heat transfer amount Q between each side wall of the container body and the other side wall is 10 of the heat transfer amount Q of the other side wall. % Or less can be set.

  As can be understood from the above description, according to the heat insulating container of the present invention, the internal temperature of the heat insulating container can be made more uniform than before, and the contents such as food can be more effectively protected from temperature changes in the external environment. it can.

The disassembled perspective view of the container main body and the cover body with which the heat insulation container which concerns on Embodiment 1 of this invention is provided. The top view which looked at the container main body shown in FIG. 1 from the direction perpendicular | vertical to a bottom wall. Sectional drawing which follows the transversal direction of the heat insulation container shown in FIG. Sectional drawing equivalent to FIG. 3 of the heat insulation container which concerns on Embodiment 2 of this invention. The top view of the container main body with which the heat insulation container which concerns on Embodiment 3 of this invention is provided. The top view of the container main body with which the heat insulation container which concerns on Embodiment 4 of this invention is provided. Sectional drawing equivalent to FIG. 3 of the heat insulation container which concerns on the Example of this invention. The graph which shows the temperature change of an external environment, and the temperature change inside a heat insulation container.

Hereinafter, an embodiment of a heat insulation container of the present invention is described in detail using a drawing.

(Embodiment 1)
FIG. 1 is an exploded perspective view of a heat insulating container 1 according to Embodiment 1 of the present invention. FIG. 2 is a plan view of the container body 10 from which the lid 20 of the heat insulating container 1 shown in FIG. FIG. 3 is a cross-sectional view along the short direction of the heat insulating container 1 shown in FIG. 1 in a sealed state.

  The heat insulating container 1 according to the present embodiment includes a box-shaped container main body 10 that has a substantially rectangular parallelepiped shape and is open at the top, and a lid body 20 that closes the upper opening 10 a of the container main body 10. The container body 10 has a bottom wall 11 and a plurality of side walls 12. More specifically, the container body 10 includes a bottom wall 11 that is rectangular in a plan view and a plurality of side walls 12 that are rectangular in a side view, and the plurality of side walls 12 are relative to each other along a pair of short sides of the bottom wall 11. In particular, a pair of short side walls 12a having a narrow width W1 and a pair of long side walls 12b having a relatively wide width W2 along a pair of long sides of the bottom wall 11 are included. In the following, the short side wall 12a and the long side wall 12b of the container body 10 may be collectively referred to as the side wall 12.

  The container main body 10 and the lid body 20 of the heat insulating container 1 can be manufactured by, for example, a foamed resin such as foamed plastic. The foamed resin constituting the heat insulating container 1 is not particularly limited as long as the heat insulating property and durability required for the heat insulating container 1 are satisfied. For example, polystyrene resin, polyolefin resin, polyester resin, etc. Can be used. In particular, from the viewpoint of moldability and cost, it is preferable to be a foam-molded product made by foam-molding pre-foamed polystyrene-based foamed resin particles by an in-mold foam molding method. In addition, the container main body 10 and the lid 20 of the heat insulating container 1 are not limited to those made of foamed resin, and may be made of, for example, a hollow material obtained by molding a resin such as polyolefin resin by an injection molding method.

  When the thermal conductivity of a foamed resin suitable as the material of the heat insulating container 1 is illustrated, for example, the thermal conductivity λ is about 0.02 W / m · K to about 5.5 W / m · K, more preferably about 0.025 W. / M · K to about 0.04 W / m · K.

  In the heat insulating container 1 according to the present embodiment, each of the side walls 12 of the container main body 10 is characterized in that the heat transfer amount of the side wall 12 is set to a thickness that is substantially equal to the heat transfer amount of the other side walls 12. Yes. More specifically, each side wall 12 is set to a thickness at which the difference between the heat transfer amount of the side wall 12 and the heat transfer amount of the other side wall 12 is approximately within 10% of the side wall 12. The heat transfer amount Q in the heat insulating container 1 of the present embodiment can be expressed by the following formulas (1) and (2).

Q = K · A · ΔT · H (1)
K = 1 / (1 / α1 + d / λ + 1 / α2) (2)

In the above formula (1), Q is the heat transfer amount (kcal) of each side wall 12, K is the heat flow rate (W / m ² · K) of each side wall 12, and A is the area of the outer surface of each side wall 12. (M ² ), ΔT is the temperature difference (K) between the inside and outside of the container body 10 sealed with the lid 20, and H is the elapsed time (h). In the above formula (2), K is the thermal conductivity of each side wall 12, α 1 is the film coefficient of the inner surface of each side wall 12, α 2 is the film coefficient of the outer surface of each side wall 12, and d is each film coefficient. The thickness (m) and λ of the side wall 12 are the thermal conductivity (W / m ² · K) of each side wall 12. The area contributing to the heat transfer rate of each side wall 12 is smaller than the area A of the outer surface of each side wall 12 and can be considered to be equal to, for example, the area of the inner surface of each side wall 12. However, in the heat insulating container 1 of the present embodiment, the area of the outer surface of each side wall 12 of the container body 10 is used as the area A that contributes to the heat transfer amount of the side wall 12 for a safer design.

  It should be noted that 1 / α1 and 1 / α2, which are terms related to the film coefficients α1 and α2 in the formula (2), are extremely small values, and the influence on the heat transfer amount Q is small. Therefore, 1 / α1 and 1 / α2 in the formula (2) can be approximated by zero. In this case, the thermal conductivity K of each side wall 12 can be expressed by the following formula (3).

      K = λ / d (3)

  In this embodiment, since the height H of each side wall 12 is equal, the area A1 of the outer surface of the short side wall 12a having a narrow width W1 is smaller than the area A2 of the outer surface of the long side wall 12b having a large width W2. . Moreover, when the material of each side wall 12 is equal, for example, when the container main body 10 is integrally molded, the thermal conductivity λ of each side wall 12 becomes equal. Here, in Formula (1), the heat transfer amount Q of the short side wall 12a is Q1, and in Formula (3), the thickness d of the short side wall 12a is d1. Further, in the equation (1), the heat transfer amount Q through the long side wall 12b is Q2, and in the equation (3), the thickness d of the long side wall 12b is d2. In this case, assuming that Q1 = Q2, the thickness d2 of the long side wall 12b can be expressed by the following formula (4).

      d2 = d1 · (A2 / A1) (4)

  In the formula (4), since the area A2 of the outer surface of the long side wall 12b is larger than the area A1 of the outer surface of the short side wall 12a, the thickness d2 of the long side wall 12b is larger than the thickness d1 of the short side wall 12a. Become thicker. Thus, by setting the thickness d2 of the long side wall 12b to be larger than the thickness d1 of the short side wall 12a so as to satisfy the relationship of the above formula (4), the heat transfer amount Q1 of the long side wall 12b and the heat transfer of the short side wall 12a. It is possible to make the heat quantity Q2 equal. The heat transfer amount Q1 of the long side wall 12b and the heat transfer amount Q2 of the short side wall 12a are preferably equal, but the difference between them may be 10% or less of the heat transfer amounts Q1 and Q2.

  Further, the side wall 12 may be formed with a concave portion or a convex portion on the inner surface or the outer surface, or may be formed with a thickness different from at least one of the height H direction and the width W1, W2 directions. In this case, in the equations (2) to (4), the thickness d of the side wall 12 can be an average value of the thickness d of the side wall 12 in the region facing the internal space of the heat insulating container 1. That is, the thickness d of the side wall 12 can be integrated in the region facing the internal space of the heat insulating container 1 and divided by the area of the region can be the thickness d of the side wall 12.

  As shown in FIG. 3, in the heat insulation container 1 of this embodiment, the thickness d3 of the bottom wall 11 of the container main body 10 is thicker than the thickness d2 of the long side wall 12b. Further, the thickness d4 of the lid 20 is thicker than the thickness d2 of the long side wall 12b of the container body 10. The thicknesses d3 and d4 of the bottom wall 11 and the lid 20 can be the average values of the thicknesses d3 and d4 of the bottom wall 11 and the lid 20 in the region facing the internal space of the heat insulating container 1, respectively. . That is, the thicknesses d3 and d4 of the bottom wall 11 and the lid 20 are integrated in the region facing the internal space of the heat insulating container 1, and the values divided by the areas of the regions are respectively calculated for the bottom wall 11 and the lid 20. The thickness can be d3 and d4.

  Hereinafter, the effect | action of the heat insulation container 1 of this embodiment is demonstrated.

  The insulated container 1 of this embodiment is stored or transported in a state in which contents that require temperature management, such as food, are accommodated. When accommodating the contents in the heat insulating container 1, contents such as food are accommodated inside the container body 10 with the upper opening 10 a of the container body 10 opened, and the upper opening of the container body 10 is opened by the lid 20. The heat insulating container 1 is sealed by closing 10a.

  When the insulated container 1 is used as a cold container, it is usually required to maintain the temperature inside the container body 10 at a temperature lower than the temperature of the external environment. In this case, heat enters the inside of the container main body 10 containing the contents such as food from the outside of the container main body 10 through the side walls 12. On the other hand, when using the heat insulation container 1 of this embodiment as a heat insulation container, it is normally required to maintain the temperature inside the container body 10 at a temperature higher than the temperature of the external environment. In this case, heat is released from the inside of the container body 10 to the outside of the container body 10 through the side walls 12.

  Here, in the heat insulation container 1 of the present embodiment, each side wall 12 of the container body 10 has a thickness at which the difference in heat transfer amount with the other side wall 12 is 10% or less of the heat transfer amount of the other side wall 12. Is set to More specifically, the short side wall 12a is set such that the difference in heat transfer amount with the long side wall 12b is 10% or less of the heat transfer amount of the long side wall 12b. Further, the long side wall 12b is set such that the difference in heat transfer amount with the short side wall 12a is 10% or less of the heat transfer amount of the short side wall 12a.

  Thereby, the temperature change characteristic in the vicinity of each side wall 12 in the container body 10 is made uniform, and as a result, the internal temperature of the heat insulating container 1 is made uniform. Therefore, according to the heat insulating container 1 of the present embodiment, it is possible to protect the contents such as foods more effectively from the temperature change of the external environment by making the internal temperature uniform than the conventional heat insulating container.

  In addition, when the thickness of each side wall 12 is set so that the heat transfer amount of each side wall 12 of the container main body 10 becomes substantially equal, that is, the heat transfer amount of the short side wall 12a is substantially equal to the heat transfer amount of the long side wall 12b. When the thicknesses of the short side wall 12a and the long side wall 12b are determined so as to be equal, the internal temperature of the heat insulating container 1 is made more uniform, and the contents such as food are more effective from the temperature change of the external environment. Can be protected.

  Moreover, in the heat insulation container 1 of this embodiment, the some side wall 12 of the container main body 10 contains the narrow short side wall 12a and the wide long side wall 12b. More specifically, the heat insulating container 1 of the present embodiment has a rectangular shape in a plan view perpendicular to the bottom wall 11 of the container body 10 and has a substantially rectangular parallelepiped shape. In this case, after determining the thickness d2 of the long side wall 12b so as to satisfy the temperature condition required inside the heat insulating container 1, the thickness d1 of the short side wall 12a is set to the above formulas (1) and (2) or the above formula. By determining based on (1) and (3), the design of the heat insulating container 1 can be optimized without increasing the thickness d1 of the short side wall 12a more than necessary.

  Moreover, in the heat insulation container 1 of this embodiment, the thickness d2 of the long side wall 12b of the container main body 10 is thicker than the thickness d1 of the short side wall 12a of the container main body 10. That is, by optimizing the design of the heat insulating container 1, the thickness d1 of the short side wall 12a is made thinner than the thickness d2 of the long side wall 12b, so that the thickness d1 of the short side wall 12a is greater than the thickness d2 of the long side wall 12b. As compared with the case of increasing the thickness, waste of the material of the heat insulating container 1 can be eliminated, and the maximum heat insulating effect can be exhibited with the minimum amount of material used.

  Moreover, in the heat insulation container 1 of this embodiment, the thickness d3 of the bottom wall 11 of the container main body 10 is thicker than the thickness d2 of the long side wall 12b of the container main body 10. The bottom wall 11 of the container body 10 is disposed adjacent to or adjacent to a road surface, a floor surface, a cargo bed, a carriage, or the like that is higher or lower than the temperature around the heat insulating container 1 when the heat insulating container 1 is transported, for example. There is a case. In such a case, by making the thickness d3 of the bottom wall 11 thicker than the thickness d2 of the long side wall 12b, it enters the inside of the heat insulating container 1 through the bottom wall 11 or releases it to the outside of the heat insulating container 1. The amount of heat generated can be reduced, the internal temperature of the heat insulating container 1 can be made more uniform, and contents such as food can be more effectively protected from temperature changes in the external environment. Moreover, the intensity | strength of the bottom wall 11 of the container main body 10 can be improved, and the durability of the heat insulation container 1 can be improved.

  Moreover, in the heat insulation container 1 of this embodiment, the thickness d4 of the lid body 20 is thicker than the thickness d2 of the long side wall 12b of the container body 10. Thereby, when using the heat insulation container 1 of this embodiment as a heat insulation container, the air with comparatively high temperature stays above the inside of a container, and the temperature difference of the inner side of the cover body 20 and an outer side is the inner side of the long side wall 12b. Even when the temperature difference exceeds the outside, the amount of heat released from the inside of the container body 10 to the outside via the lid 20 can be reduced.

  As described above, according to the heat insulating container 1 of the present embodiment, it is possible to more effectively protect contents such as food from temperature changes in the external environment by making the internal temperature of the heat insulating container 1 uniform than before. it can.

(Embodiment 2)
FIG. 4 is a cross-sectional view corresponding to FIG. 3 of the heat insulating container 1A according to Embodiment 2 of the present invention. In the heat insulating container 1A of the present embodiment, the cold storage material 30 is disposed on the upper portion of the container body 10 so as to face the lower surface of the lid body 20, and the thickness d4 of the lid body 20 is the thickness d2 of the long side wall 12b of the container body 10. It is different from the heat insulating container 1 of the first embodiment described above in that it is thinner. Since the other points of the heat insulating container 1A of the present embodiment are the same as those of the heat insulating container 1 of the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  1 A of heat insulation containers of this embodiment have the step-shaped holding part 13 which hold | maintains the edge part of the cool storage material 30 inside the upper end part of the long side wall 12b. The cold storage material 30 is configured by enclosing a liquid material in which water, a gel agent, a preservative, a coloring agent, and the like are mixed in a rectangular flat polyethylene resin container, for example. Thereby, the cold air of the frozen regenerator material 30 can be lowered from the upper side to the lower side in the container body 10, and the cooling effect inside the container body 10 can be improved.

  Further, in the heat insulating container 1A of the present embodiment, the thickness d4 of the lid 20 is thinner than the thickness d2 of the long side wall 12b of the container body 10. 1 A of heat insulation containers of this embodiment hold | maintain the both ends of the cool storage material 30 with the holding part 13 of the container main body 10, and the cool storage material 30 is arrange | positioned at the upper part of the container main body 10 facing the lower surface of the cover body 20. ing. Therefore, the amount of heat transferred to the inside of the container through the lid 20 increases, but the heat that tries to enter the inside of the container through the lid 20 can be absorbed by the cold storage material 30 and blocked. Therefore, the thickness d4 of the lid 20 can be reduced without reducing the performance of the heat insulating container 1A, thereby reducing the size and weight of the heat insulating container 1A and reducing the cost.

  The thickness d4 of the lid 20 may be equal to or greater than the thickness d2 of the long side wall 12b of the container body 10. In this case, the amount of heat transferred to the inside of the container through the lid 20 can be reduced, and the cold storage time of the cold storage material 30 can be extended. Also, by providing a gap between the lid 20 and the cold storage material 30, an air layer is interposed between the lid 20 and the cold storage material 30, and compared with the case where the lid 20 and the cold storage material 30 are in close contact with each other. Thus, the cooling time of the cold storage material 30 can be extended.

(Embodiment 3)
FIG. 5 is a plan view of a container body 10A included in the heat insulating container according to Embodiment 3 of the present invention. The heat insulation container of this embodiment is different from the heat insulation container of Embodiment 1 described above in that the width W of each side wall 12 is equal in a plan view perpendicular to the bottom wall 11 of the container body 10A. Since the other points of the heat insulating container of the present embodiment are the same as those of the heat insulating container of the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  The heat insulating container of this embodiment has a substantially square shape in a plan view perpendicular to the bottom wall 11 of the container body 10A, and the width W of each side wall 12 is equal. Although illustration is omitted, the heat insulating container of the present embodiment includes a lid having a shape corresponding to the planar shape of the container body 10A. Each side wall 12 of the container main body 10 </ b> A is set to a thickness such that the difference in heat transfer amount with the other side wall 12 is 10% or less of the heat transfer amount of the other side wall 12. More specifically, in the heat insulating container of the present embodiment, each side wall 12 of the container body 10A is set to a thickness that makes the amount of heat transfer equal to the other side walls 12. In other words, the side walls 12 of the container body 10A have the same thickness and the same amount of heat transfer.

  Therefore, according to the heat insulating container of the present embodiment, as in the heat insulating container of the first embodiment described above, the internal temperature of the heat insulating container is made more uniform than before, and the contents such as food are more effective from the temperature change of the external environment. Can be protected.

(Embodiment 4)
FIG. 6 is a plan view of a container body 10B provided in the heat insulating container according to Embodiment 4 of the present invention. The heat insulating container of the present embodiment has a hexagonal shape in a plan view perpendicular to the bottom wall 11 of the container body 10B, and has a long side wall 12b having a wide width W2 and a middle side wall 12c having a narrower width W3 than the long side wall 12b. And it differs from the heat insulation container 1 of the above-mentioned Embodiment 1 by the point which has the short side wall 12a whose width W1 is narrower than the inner side wall 12c. Since the other points of the heat insulating container of the present embodiment are the same as those of the heat insulating container 1 of the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  In the heat insulating container of the present embodiment, each side wall 12 of the container main body 10B is set to a thickness such that the difference in heat transfer amount with the other side wall 12 is 10% or less of the heat transfer amount of the other side wall 12. Yes. More specifically, the long side wall 12b is set to a thickness d2 at which the difference in heat transfer amount between the middle side wall 12c and the short side wall 12a is 10% or less of the heat transfer amount of the middle side wall 12c and the short side wall 12a. . The intermediate wall 12c is set to a thickness d5 at which the difference in heat transfer amount between the long side wall 12b and the short side wall 12a is 10% or less of the heat transfer amount between the long side wall 12b and the short side wall 12a. Further, the short side wall 12a is set to a thickness d1 at which the difference in heat transfer amount between the middle side wall 12c and the long side wall 12b is 10% or less of the heat transfer amount of the middle side wall 12c and the long side wall 12b. The long side wall 12b, the middle side wall 12c, and the short side wall 12a preferably have the same amount of heat transfer.

  Thereby, the thickness d2 of the long side wall 12b is thicker than the thickness d5 of the middle side wall 12c, and the thickness d5 of the middle side wall 12c is thicker than the thickness d1 of the short side wall 12a. In other words, the thickness d2 of the long side wall 12b is the thickest, and the thickness d1 of the short side wall 12a is the thinnest. Therefore, according to the heat insulating container of the present embodiment, as in the heat insulating container 1 of the first embodiment described above, the internal temperature of the heat insulating container is made more uniform than before, and the contents of food and the like are further removed from the temperature change of the external environment. It can be effectively protected. When the widths W1, W2, and W3 of the side walls 12 are equal, the thicknesses d1, d2, and d5 of the side walls 12 can be made equal.

  The container body 10 of the heat insulating container 1 according to the embodiment of the present invention may be a multilayer container or a multiple container. For example, when the container body 10 is a double container composed of an outer container and an inner container disposed inside thereof, the inner surface of the side wall of the outer container and the outer surface of the side wall of the inner container are close to each other, The heat transmissivity K can be expressed by the following formula (5).

      K = 1 / {(da / λa) + (db / λb)} (5)

  In the above formula (5), λa is the thermal conductivity (W / m · K) of the material constituting the outer container, λb is the thermal conductivity (W / m · K) of the material constituting the inner container, and da is the outer side. The thickness (m) and db of the side wall of the container are the thickness (m) of the side wall of the inner container. Thereby, even if the side wall 12 of the container main body 10 of the heat insulation container 1 is a multilayer structure or a heat insulation container is a multiple container, the heat transfer amount of the side wall 12 of the container main body 10 can be known, and the subject of this invention is solved. Can do.

  The embodiment of the present invention has been described in detail above, but the specific configuration is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention, It is included in the present invention.

(Example)
FIG. 7 is a cross-sectional view corresponding to FIG. 3 of the heat insulating container 1B according to the embodiment of the present invention. The heat insulating container 1B of the present example has the same configuration as the heat insulating container 1A described in the second embodiment, and the cold storage material 30 is disposed on the upper portion of the container body 10 so as to face the lower surface of the lid 20. Yes. The heat insulating container 1B was made of expanded polystyrene, and its thermal conductivity was 0.033 W / m · K. The height H of the container body 10 of the heat insulating container 1B is 230 mm, the width W2 (see FIG. 2) of the long side wall 12b on the outer surface of the container body 10 is 380 mm, and the width W1 of the short side wall 12a on the outer surface of the container body 10 (See FIG. 2) was 305 mm. The dimensions of the outer surface of the bottom wall 11 and the lid 20 were 230 mm long × 305 mm wide. Moreover, the thickness d2 of the long side wall 12b was 25 mm thicker than the short side wall 12a, and the thickness d1 (see FIG. 2) of the short side wall 12a was 20 mm thinner than the long side wall 12b. Further, the thickness d3 of the bottom wall 11 of the container body 10 was set to 35 mm, and the thickness d4 of the lid body 20 was set to 30 mm.

The heat transmissivity calculated based on the formula (3) is as follows: the long side wall 12b is 1.32 W / m ² · K, the short side wall 12a is 1.65 W / m ² · K, and the bottom wall 11 is about was 0.94W / m 2 · ^K, the lid 20 was 1.1W / ^{m 2} · K. In equation (1), the heat transfer amount Q calculated with ΔT of 10 ° C. and time H of 10 hours is about 23.15 kcal for the long side wall 12 b, about 23.15 kcal for the short side wall 12 a, and about 21. 86 kcal and the lid 20 were about 25.50 kcal. In the heat insulating container 1B of the example, the long side wall 12b has a heat transfer amount difference of about 0.08 kcal from the short side wall 12a, which is about 0.35% of the heat transfer amount of the short side wall 12a of about 23.15 kcal. The heat transfer amount of the long side wall 12b and the heat transfer amount of the short side wall 12a were substantially equal.

(Comparative example)
The thickness d2 of the long side wall 12b of the container body 10 is set to 20 mm thinner than the short side wall 12a, the thickness d1 of the short side wall 12a is set to 30 mm thicker than the long side wall 12b, and the thickness d3 of the bottom wall 11 and the lid 20 is set. A heat insulating container of a comparative example having the same configuration as the heat insulating container 1B of the example was manufactured except that d4 was set to 30 mm.

Heat transmission coefficient calculated based on the equation (3), the long side wall 12b is 1.65W / m 2 · ^K, the short side wall 12a, a bottom wall 11 and the lid 20 is 1.1 W / ^{m 2} · respectively K. In the above formula (1), the heat transfer amount calculated with ΔT being 10 ° C. and time H being 10 hours is that the long side wall 12b is about 28.84 kcal, the short side wall 12a is about 15.43 kcal, the bottom wall 11 and the lid 20 are Each was about 25.50 kcal. In the heat insulating container of the example, the long side wall 12b had a heat transfer amount difference of about 13.41 kcal from the short side wall 12a, which was about 86.9% of the heat transfer amount of the short side wall 12a of about 15.43 kcal. .

  Next, the experiment which compares the heat insulation container 1B of an Example and the heat insulation container of a comparative example was conducted. First, as shown in FIG. 7, 1000 g of the cold storage material 30 is arranged inside the heat insulating container 1B of the example and the heat insulating container of the comparative example, and 10 500 ml PET bottles P containing water are accommodated and the lid body. Sealed with 20. And in the heat insulation container 1B of an Example and the heat insulation container of a comparative example, the temperature of external environment is changed, the temperature of the PET bottle P1 arrange | positioned in the center, and the temperature of the PET bottle P2 of the side part adjacent to the long side wall 12b are changed. It was measured.

  FIG. 8A shows a temperature change in the external environment of the heat insulating container 1B of the example and the heat insulating container of the comparative example, and FIG. 8B shows a central plastic bottle of the heat insulating container 1B of the example and the heat insulating container of the comparative example. The temperature of P1 and the temperature of the side plastic bottle P2 are shown. Table 1 below shows the temperature of the central plastic bottle P1 of the heat insulating container 1B of the example and the heat insulating container of the comparative example, the temperature of the side plastic bottle P2, and the temperature difference therebetween.

  As shown in FIG. 8 (A) and Table 1, the temperature of the external environment was increased from 22.1 ° C. to 30.0 ° C. in 0.5 hours from the start of the experiment, and then about 30 over 3.5 hours. Maintained at 0 ° C. When 4 hours have passed since the start of the experiment, the temperature of the external environment was increased from about 30.0 ° C. to about 40.0 ° C. over 0.5 hours, and then about 40.0 over 3.5 hours. Maintained at ° C. When 8 hours have passed since the start of the experiment, the temperature of the external environment was decreased from about 40.0 ° C. to about 30.0 ° C. over 0.5 hours, and then about 30.0 over 1.5 hours. Maintained at ° C.

  As a result, as shown in FIG. 8B and Table 1, in the heat insulating container 1B of the example, the temperature increase of the central plastic bottle P1 is 3.2 ° C., and the temperature increase of the side plastic bottle P2 is 4. The temperature difference between the central PET bottle P1 and the side PET bottle P2 at 6 ° C. was suppressed to 1.6 ° C. at the maximum. On the other hand, in the heat insulating container of the comparative example, the temperature increase of the central plastic bottle P1 is 3.8 ° C., the temperature increase of the side plastic bottle P2 is 5.5 ° C., the central plastic bottle P1 and the side PET The temperature difference of the bottle P2 was 1.8 ° C. at the maximum. From the above results, in the heat insulating container 1B of the embodiment of the present invention, it was confirmed that the internal temperature is made uniform and the contents such as food can be more effectively protected from the temperature change of the external environment than the heat insulating container of the comparative example. It was.

1, 1A, 1B Insulated container, 10, 10A, 10B Container body, 10a Top opening, 11 Bottom wall, 12 Side wall, 12a Short side wall, 12b Long side wall, 20 Lid, 30 Cold storage material, d1 Thickness of short side wall, d2 long side wall thickness, d3 bottom wall thickness, d4 lid thickness, W1 short side wall width, W2 long side wall width

Claims (3)

A heat insulating container comprising a container body having a bottom wall and a plurality of side walls, the upper part being opened, and a lid for closing the upper opening of the container body,
A cold storage material is disposed on the upper part of the container body so as to face the lower surface of the lid,
The plurality of side walls include a short side wall and a long side wall wider than the short side wall,
The long side wall is thicker than the short side wall,
The lid body is thinner than the long side wall,
Each of the side walls is set to a thickness such that a difference between a heat transfer amount applied to the side wall and a heat transfer amount applied to the other side wall is 10% or less. The insulated container according to claim 1 , wherein the bottom wall is thicker than the long side wall. The heat transfer amount Q of the side wall is as follows: the thermal conductivity of the side wall is K, the area of the outer surface of the side wall is A, the temperature difference between the inside and the outside of the container body is ΔT, the elapsed time is H, the inner surface of the side wall Is expressed by the following equations (1) and (2), where α1 is the film coefficient, α2 is the film coefficient of the outer surface of the side wall, d is the thickness of the side wall, and λ is the thermal conductivity of the side wall. The insulated container according to claim 1 or 2 , wherein
Q = K · A · ΔT · H (1)
K = 1 / (1 / α1 + d / λ + 1 / α2) (2)

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