JPH0595877U - Thermal stress relaxation structure of heat insulation container - Google Patents

Abstract

(57) [Abstract] [Purpose] To alleviate the stress of the cover plate at the end face of the heat insulating layer where the maximum stress is generated by the thermal expansion of the inner wall of the heat insulating container, and to improve the heat insulating performance. [Structure] By forming a step portion 18 in the vicinity of the opening 14 of the heat insulating layer 13, the plate width W of the lid plate 17 is made larger than the thickness T of the intermediate portion of the heat insulating layer 13 other than in the vicinity of the opening. . [Effect] The lid plate 17 deforms reasonably and absorbs the thermal expansion of the inner wall 11. Therefore, the stress generated in the cover plate 17 is relieved. Further, since the length of the heat bridge formed by the cover plate 17 is increased, the heat transfer resistance is increased and the heat insulation performance is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermal stress relaxation structure for a heat insulating container used at high temperatures.

[0002]

[Prior Art]

 As shown in FIG. 2, a conventional heat insulating container of this type is formed of a metal plate, a plastic plate, or the like into a box shape having an inner and outer double wall structure, and has a heat insulating layer 3 between the inner wall 1 and the outer wall 2. The heat insulating lid 5 is provided in the opening 4. The heat insulating layer 3 is filled with a heat insulating material 6 such as silica fine powder or glass fiber, then the end face on the opening 4 side is sealed with a cover plate 7, and the inside is evacuated to improve the heat insulating property. ing. This insulated container is used to house an object inside and keep it at a high temperature, eg 300-400 ° C. At that time, half of the thermal expansion of the inner wall 1, which has become hotter than that of the outer wall 2, occurs on the opening 4 side, and the thermal expansion is absorbed by the deformation of the cover plate 7, as shown by the phantom line in the figure. ..

[0003]

[Problems to be solved by the device]

 However, in the above conventional heat insulating container, when the thickness t of the heat insulating layer 3 is set to a normal thickness, the thermal expansion of the inner wall 1 toward the opening 4 side is absorbed by the deformation of the cover plate 7. The lid plate 7 is largely deformed and a large stress is generated. Since the cover plate 7 is repeatedly subjected to such stress, it is damaged in a short time, and the vacuum of the heat insulating layer 3 is broken. On the other hand, since the lid plate 7 forms a heat bridge, heat is easily transferred from the inner wall 1 to the outer wall 2 via the lid plate 7, which causes a problem that the heat insulating performance is deteriorated. These problems become more prominent as the thickness t of the heat insulating layer 3 is reduced for the size of the heat insulating container in order to improve the volumetric efficiency of the heat insulating container.

Therefore, the present invention aims to solve such problems, prevent damage to the lid plate of the heat insulating container, and improve the heat insulating performance.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is formed in a box shape of an inner and outer double wall structure having an opening on one side, and the end surface of the heat insulating layer provided between the inner wall and the outer wall on the opening side is sealed by a cover plate. In the above heat insulating container, a step is formed in the heat insulating layer in the vicinity of the opening, and the plate width of the cover plate is larger than the thickness of the heat insulating layer other than in the vicinity of the opening.

[0006]

[Action]

 According to such a configuration, since the step portion is formed near the opening of the heat insulating layer and the plate width of the lid plate is made larger than the thickness of the intermediate portion of the heat insulating layer other than near the opening portion, the lid plate is opened. It is possible to make the plate width of the cover plate sufficiently large so as to reasonably absorb the thermal expansion of the inner wall toward the side. Therefore, the stress generated in the lid plate when absorbing the thermal expansion of the inner wall is significantly relieved, and the lid plate is prevented from being damaged by repeated stress. Moreover, since the length of the heat bridge formed by the cover plate is longer than that of the conventional cover plate, the heat transfer resistance is increased and the heat insulation performance is improved.

[0007]

【Example】

 The heat-insulating container shown in FIG. 1 is formed of a metal plate, a plastic plate, or the like in a box shape having an inner-outer double-wall structure, has a heat-insulating layer 13 between the inner wall 11 and the outer wall 12, and has an opening 14 with a heat-insulating lid. 15 are provided. The heat insulating layer 13 was filled with a heat insulating material 16 such as silica fine powder or glass fiber, then the end face on the opening 14 side was sealed with a lid plate 17, and the inside was evacuated to improve the heat insulating property. It is a thing.

In the portion of the heat insulating layer 13 in the vicinity of the opening 14, the plate width W of the lid plate 17 is changed to the thickness T of the heat insulating layer 13 other than in the vicinity of the opening by forming a step 18 protruding inward. It is 1.5 to 2.0 times larger. In the conventional heat insulating container, as shown in FIG. 2, the plate width w of the lid plate 7 is the same as the thickness t of the heat insulating layer 3. Therefore, the plate width W in the present embodiment is the same as the conventional plate width. It is 1.5 to 2.0 times w.

Therefore, in the heat-insulating container having the above-described configuration, the thermal expansion of the inner wall 11 toward the opening 14 side when the contained object is heated to a high temperature and kept warm is naturally absorbed by the deformation of the cover plate 17. It This is because when the thermal expansion amount of the inner wall 11 is the same as the conventional one, the ratio of the deformation amount of the lid plate 17 to the plate width W is larger than that of the conventional deformation amount of the lid plate 7 to the plate width w. This is because the stress is greatly reduced, and the stress generated in the lid plate 17 is significantly relieved. Therefore, it is possible to prevent the lid plate 17 from being damaged by this stress. For example, if the plate width W of the cover plate 17 is increased from 40 mm to 60 mm, the service life of the cover plate 17 with respect to repeated thermal stress is approximately tripled.

Further, since the length of the heat bridge formed by the cover plate 17 is 1.5 to 2.0 times longer than that of the conventional cover plate 7, heat is transferred from the inner wall 11 to the outer wall 12 via the cover plate 17. In this case, the heat transfer resistance is increased, which improves the heat insulation performance.

The stepped portion 18 may be formed on the outer wall 12 side instead of being formed on the inner wall 11 side as shown.

[0012]

[Effect of the device]

 As described above, according to the present invention, the step is formed near the opening of the heat insulating layer, and the plate width of the lid plate is made larger than the thickness of the heat insulating layer other than the vicinity of the opening. It is possible to significantly reduce the amount of deformation of the lid plate when absorbing the thermal expansion toward the opening side of the. Therefore, the lid plate can be reasonably deformed to absorb the thermal expansion of the inner wall, and the stress generated in the lid plate can be significantly relieved. Therefore, the lid plate can be prevented from being damaged by the repeated stress, and the life of the heat insulating container can be improved.

Further, since the length of the heat bridge formed by the cover plate can be increased, the heat transfer resistance when heat is transferred from the inner wall to the outer wall via the cover plate can be increased, and the heat insulation performance can be improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of a heat insulating container according to an embodiment of the present invention.

FIG. 2 is a partially cutaway sectional view showing an example of a conventional heat insulating container.

[Explanation of symbols]

 11 Inner wall 12 Outer wall 13 Insulation layer 14 Opening 17 Cover plate 18 Step W width

Claims (1)

[Scope of utility model registration request] 1. A heat-insulating container, which is formed in a box shape having an inner-outer double-wall structure having an opening on one side and in which an opening-side end surface of a heat-insulating layer provided between the inner wall and the outer wall is sealed by a lid plate,
A thermal stress relaxation structure for a heat insulating container, characterized in that a step portion is formed in the heat insulating layer near the opening so that the plate width of the lid plate is larger than the thickness of the heat insulating layer other than near the opening.