JPH0563299B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a flat vacuum heat insulating material.

[Background of the invention]

Vacuum heat insulating materials with high heat insulating properties have been limited to cylindrical or spherical structures due to their pressure-resistant structure, but recently flat or box-like structures with built-in spacers have been considered.

This spacer is made by laminating ultra-thin diameter inorganic fibers in a direction perpendicular to the heat transfer direction, and has a heat insulating function due to multi-stage contact thermal resistance.
As it is, the density is low and the compressive deformation due to vacuum pressure is large, and the entire panel is deformed greatly, making it difficult to assemble. Measures have been taken to increase density and reduce compressive deformation by sewing through the material in the direction of heat transfer.

However, this method has a drawback in that since some of the fibers coincide with the heat transfer direction, heat is directly transmitted to the outer panel of the vacuum container due to heat conduction of the sewn fibers, reducing the heat insulation function.

[Purpose of the invention]

The present invention has been made to improve the above defects.

[Summary of the invention]

In other words, a fiber mat made of fine-diameter inorganic fibers randomly laminated with the main direction perpendicular to the heat transfer direction, and a high-density fiber mat with sewn fibers passed diagonally through the layers is installed inside a flat panel. It is a vacuum insulation material whose interior is sealed to create a high vacuum.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1 to 5. 1 is made of stainless steel,
1a is a flange thereof, 1b is a cylindrical collar provided at the pressed bottom of the drawn outer plate 1, 2 is an outer plate serving as a lid of the drawn outer plate 1, and 3 is a vacuum pipe. One end of it is welded to the collar 1b. 4 is a high-density fiber mat made of small-diameter inorganic fibers, and the inorganic material has heat resistance of several hundred degrees or more and can prevent gas generation.

4a are small diameter fibers randomly laminated with the main direction of the fiber mat 4 being perpendicular to the heat transfer direction, and these small diameter fibers 4a are in point contact with each other,
This is configured to have multiple stages in the heat transfer direction. 4b
is a sewn-in fiber that penetrates diagonally to the heat transfer direction in order to withstand pressure and reduce deformation under pressure, thereby forming a high-density fiber mat 4.

In order to construct a vacuum insulation material with the hanging parts, first, a fiber mat 4 is installed inside the concave part of the aperture outer plate 1,
Cover with the outer plate 2, hermetically weld the flange 1a and the outer periphery of the outer plate 2, connect a vacuum pump (not shown) to the vacuum pipe 3, heat it to a high temperature while exhausting, and degas it. After baking and degassing are completed, a part of the vacuum pipe 3 is sealed and cut to complete the vacuum insulation material.

〔Effect of the invention〕

In the vacuum heat insulating material constructed as described above, the small diameter fibers 4a of the fiber mats 4 serving as spacers are laminated at right angles to the heat transfer direction and randomly, so that heat transfer is achieved through large contact points with multiple stages. The sewn-in fibers 4b, which have a high thermal resistance and have a high heat insulation function, and are penetrated to increase the density, do not match the heat transfer direction and run obliquely to it, so that the sewn-in fibers 4a are elongated. This increases the heat conduction resistance and has the effect of preventing heat loss through this. The convection heat transfer loss is reduced by the vacuum, the radiation loss is reduced by the small diameter fibers 4a that are reflected in multiple stages, and the heat loss around the outer panels by the aperture skin 1 and the skin 2 is reduced by the stainless steel material with low thermal conductivity. It prevents heat build-up and exhibits a high overall heat insulation function.

Furthermore, since the fiber mat 4 has a high density, it is less compressively deformed by vacuum pressure, and has the effect of facilitating assembly and installation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a vacuum insulation material, FIG. 2 is a vertical sectional view of FIG. 1, FIG. 3 is a perspective view of a fiber mat, and FIG. 4 is a diagram of random lamination of small diameter fibers.
FIG. 5 is an enlarged side view of the fiber mat. 1... Drawn outer plate, 1a... Flange, 1b... Collar, 2... Outer plate, 3... Vacuum pipe, 4... Fiber mat, 4a... Small diameter fiber, 4b... Sewing fiber.

Claims (1)

[Claims] 1. The main direction of inorganic small diameter fibers 4a is randomly laminated in a direction perpendicular to the heat transfer direction, and the sewing fibers 4b are penetrated diagonally to the heat transfer direction. A vacuum insulation material comprising a high-density fiber mat 4, installed inside a flat panel, and sealed to create a high vacuum inside. 2. The vacuum insulation material according to claim 1, characterized in that the stitched fibers 4b are penetrated from both sides of the fiber mat 4.