JPH057023A - Integrally molded heat insulating retainer - Google Patents

Abstract

PURPOSE:To improve thermal insulation properties in the range from a low temperature to a high temperature, by arranging two cylinders, whose diameters are different, in the superposed coaxial circles state, and integrally molding the adjacent cylinders in a unified body at the central parts of the cylinders. CONSTITUTION:Reinforcing fiber impregnated with resin is wound around a rotary mandrel 14 in the state that an auxiliary mandrel 15 and a bolt 16 are removed. When molding is finished until a part corresponding to an inner cylinder, the mandrel is interrupted and the auxiliary mandrel 15 is fixed to the mandrel 14 by using the bolt 16. By rotating again the mandrel 14 the reinforcing fiber impregnated with resin is wound around the central part and the auxiliary mandrel 15, thus forming an outer cylinder part 1 and a central part 3. These are left to stand for a specified time and then the bolt is removed and the auxiliary mandrel 15 is pulled out. Thereby a double cylinder heat insulating retainer which is connected by integral molding at the central part can be obtained, so that a heat insulating retainer for a low temperature vessel which retainer has excellent heat insulating properties can be obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat insulating support made of fiber reinforced resin.

[0002]

2. Description of the Related Art A container for holding a low temperature, particularly a container for holding a cryogenic temperature, that is, a heat insulating container for storing liquid helium is excellent in order to minimize the evaporation amount of liquid helium. It is necessary to have good heat insulation properties and to have a small amount of heat intrusion into the interior. In a simple container for liquid helium, various adiabatic support structures have been adopted to satisfy this condition.However, in a container for a superconducting magnet used for a levitation railway, the levitation force acting on the internal superconducting magnet and It is necessary to transfer the driving force to the room temperature section,
Therefore, while it is necessary to have a cooperative supporting force between the liquid helium inner tank containing the superconducting coil and the room temperature part,
Since it is desirable to minimize the heat infiltration into liquid helium, it is a very difficult problem.

Regarding the heat insulating support structure of a cryogenic container, in JP-A-55-87000, JP-A-56-152211, and JP-A-59-98570, a plurality of cylinders having different diameters are arranged concentrically. However, it is constructed by alternately combining the joints of adjacent cylinders at the center of the cylinders and the joints at both ends, and can support front, rear, left and right, and up and down by a single unit. The structure is disclosed.

[0004]

However, in the conventional method, since the cylinders are individually manufactured and then the adjacent cylinders are joined to each other, there remains a problem to withstand a large load. That is, it is difficult to join the cylinders together, and it is necessary to perform machining to smooth the surfaces of the cylinders before joining.In addition, the concentric cylinders are joined together with an adhesive at the center. Even if it was tried, it was difficult to apply sufficient pressure, there was a problem in adhesive strength, and further productivity was lacking. The present invention is intended to solve the above-mentioned drawbacks, and provides a heat insulating support material for a cryogenic container having excellent heat insulating performance.

[0005]

The present invention has a structure in which two cylinders having different diameters are concentrically overlapped with each other, and adjacent cylinders are integrally formed at the center of the cylinder. The present invention relates to an integrally molded heat-insulating support material made of a fiber-reinforced resin.

The present invention will be described below with reference to the drawings.
FIG. 1 shows an example of an integrally molded heat-insulating support material made of fiber reinforced resin of the present invention, which is a heat-insulating support material having a double cylindrical structure in which an adjacent outer cylinder 1 and inner cylinder 2 are integrally molded at the central portion. is there.

FIG. 2 is a sectional view of a heat insulating support structure for a cryogenic container using the integrally formed heat insulating support shown in FIG. This is because the adjacent outer cylinder 1 and inner cylinder 2 of the present invention are a double-cylinder heat insulating support member integrally formed at the central portion 3, and the adjacent outer cylinder 4 and inner cylinder 5 are integrally formed at the central portion 6. The heat-insulating support structure made of a quadruple cylinder in which the heat-insulating support material made of the formed double cylinder is joined by the connecting jig 7 is shown. The heat insulating support structure connects and fixes the low temperature container side wall 8 and the room temperature mounting part side wall 9. A well-known method such as welding or pin joining is used as a fixing method for each.

FIG. 3 shows a heat insulation structure for a superconducting coil used in a levitation railway, and is a schematic side view of a heat insulation support structure of a cryogenic container using the heat insulation support material shown in FIG. In this heat insulating support structure, a cryogenic container 12 containing a superconducting coil and a truck mounting portion 11 are fixed by a heat insulating support material 10. Here, the auxiliary wheels and the like are omitted, and a part 13 of the carriage is shown.

A filament winding method, a hand lay-up method or the like can be applied as a method for producing the integrally molded heat-insulating support material of the present invention, but the filament winding method (hereinafter sometimes referred to as FW method) is preferable. Figure 4
Shows an example of a set of mandrels used when the integrally molded heat-insulating support material of the present invention is manufactured by the filament winding method, and shows a state in which an auxiliary mandrel 15 is fixed to a cylindrical mandrel 14 with bolts 16. ..

In manufacturing the integrally molded heat-insulating support material of the present invention, first, with the auxiliary mandrel 15 and the bolts 16 removed, the rotating mandrel 14 is wrapped with a resin-impregnated reinforcing fiber, and then the inner cylinder is wound. After forming the corresponding part, stop the mandrel and fix the auxiliary mandrel 15 to the mandrel 14 with bolts 16.
The mandrel 14 is rotated again, and the reinforcing fiber impregnated with the resin is wound around the central part and the auxiliary mandrel 15 to form the outer cylinder part 1 and the central part 3 in FIG.

When the resin used is a room temperature curable resin, it is allowed to stand for a predetermined time, and when it is a heat curable resin,
After holding at a predetermined temperature for a predetermined time, the bolt 16 is removed and the auxiliary mandrel 15 is pulled out to obtain a double-cylinder heat-insulating support material integrally connected at the central portion.

It is preferable that the auxiliary mandrel 15 has a taper of 0.5 ° or more only on the outer periphery toward the central portion. With a taper of less than 0.5 °, it is difficult to pull out the auxiliary mandrel 15 from the FRP after curing.

Also, the mandrel 14 and the auxiliary mandrel 1
As for the material of No. 5, it is preferable to use two kinds of metals having different thermal expansion coefficients. That is, when a metal having a large coefficient of thermal expansion is used for the mandrel 14 and a metal having a coefficient of thermal expansion smaller than that of the mandrel 14 is used for the auxiliary mandrel 15, in the case of a thermosetting resin, the expansion of the mandrel 14 during curing is Since it is large, pressure is applied to the cylindrical portion, and the fibers are better impregnated with the resin. Also, when the mandrel is released from the mold, the mandrel 14 shrinks more when cooled,
Easy to pull out and preferable.

Examples of the reinforcing fiber used in the present invention include alumina fiber, ceramic fiber, glass fiber, carbon fiber and aramid fiber. Carbon fibers are preferable in a range of only an extremely low temperature because they have low thermal conductivity, and glass fibers are preferable in a temperature range of liquid nitrogen to room temperature because they have low thermal conductivity.

Alumina fibers have excellent heat insulating properties from room temperature to extremely low temperatures. For example, carbon fiber has a lower thermal conductivity than glass fiber in an extremely low temperature range, but conversely, glass fiber has a lower thermal conductivity than carbon fiber in a room temperature range. Therefore, in order to minimize the amount of heat penetration, it was necessary to take a complicated structure using both glass fiber reinforced resin and carbon fiber reinforced resin. However, since the alumina fiber shows almost the same thermal conductivity as the lower one of the glass fiber and the carbon fiber in a wide temperature range from the extremely low temperature region to the room temperature region, the entire alumina fiber reinforced resin (hereinafter, ALF
(Sometimes referred to as RP).

The composition of the alumina fiber used in the present invention has an alumina content of 60% by weight or more and a silica content of 4%.
0 wt% or less, preferably 72 wt% or more of alumina, 28 wt% or less of silica, and more preferably 75 to 75
It is preferably 98% by weight or less and 25 to 2% by weight silica.
Of the silica content, 10% by weight based on the total weight of the fiber
Below, preferably in the range of 5 wt% or less, lithium, beryllium, boron, sodium, magnesium,
It may be replaced with one or more oxides of phosphorus, potassium, calcium, titanium, chromium, manganese, yttrium, zirconium, lanthanum, tungsten, barium.

The form of the alumina fiber used in the present invention is preferably used as long fibers because the characteristics of high strength can be utilized. When it is a long fiber, it is preferably used as a roving, a mat or a woven fabric.

As such an alumina fiber, Artex (trade name: manufactured by Sumitomo Chemical Co., Ltd.), Arsen (trade name: manufactured by Denki Kagaku Co., Ltd.), Nextel (trade name: manufactured by 3M Company), Examples include Almax (trade name: manufactured by Mitsui Mining Co., Ltd.) and FP Fiber (manufactured by Du Pont). Among these, preferred alumina fibers are
These are Altex (produced by Sumitomo Chemical Co., Ltd.) and Arsen (produced by Denki Kagaku Co., Ltd.).

The strength and elastic modulus of the alumina fiber are 150 kg / mm ² and 2, respectively, when the fiber diameter is about 10 μm.
Those having a value of 0 t / mm ² or more are preferable. For example, an alumina fiber Altex having a diameter of 10 μm and having a composition of 85% by weight of alumina and 15% by weight of silica has a tensile strength of 180 kg / mm ² or more and a tensile elastic modulus of 21 t /
Indicates a value of mm ² or more.

It is desirable that the X-ray structure of the alumina fiber does not substantially show the reflection of α-alumina. Generally, in inorganic fibers, the crystal grains of the inorganic substance forming the fibers grow in the fiber at a high temperature, and the fiber strength is remarkably lowered due to the grain boundary destruction between these crystal grains. At the same time, the surface area of the fibers decreases with the growth of the crystal particles, which reduces the adhesion with the resin. This circumstance is characterized by the reflection of α-alumina in the X-ray diffraction image of the alumina fiber according to the results of studies by the present inventors. Therefore, the alumina fiber used in the present invention is preferably manufactured so that the reflection of α-alumina does not appear in the X-ray diffraction image.

Since ARTEX is composed of very fine crystallites of about several hundred angstroms, it has a thermal conductivity smaller than that of ordinary alumina fiber, and is therefore an optimum material for the purpose of the present invention.

As the synthetic resins used in the matrix of the present invention, known synthetic resins generally used in the production of fiber reinforced composite materials by the FW method, the hand layup method and the like are used. For example, epoxy resin,
Thermosetting of phenol resin, alkyd resin, urea resin, melamine resin, unsaturated polyester resin, aromatic polyamide resin, polyamide-imide resin, vinyl ester resin, polyester-imide resin, polyimide resin, polybenzothiazole resin, silicon resin, etc. Resin, polyethylene, polypropylene, polymethylmethacrylate, polystyrene (including so-called high impact polystyrene), polyvinyl chloride, fluororesin, ABS
Resin, styrene-acrylonitrile copolymer, polyamide (nylon 6,6,6,6,10,6,11,6.1
2 etc.), polyacetal, polysulfone, polycarbonate, polyphenylene oxide, polyetheretherketone, polyetherketone, polyamideimide,
There may be mentioned thermoplastic resins such as polysulfone, polyether sulfone and aromatic polyester. Preferred thermosetting resin compositions include epoxy resins, unsaturated polyester resins and vinyl ester resins. Preferred thermoplastic resins include polyetheretherketone, polyethersulfone and polyamideimide resins. It is also effective to perform plating, vapor deposition, etc. after molding using an epoxy resin for plating in order to reduce heat radiation of the support material.

[0023]

The integrally molded heat insulating support material of the present invention is not a cylinder in which concentric circularly stacked layers are joined together by an adhesive in the central portion, but is integrally molded by a filament winding method and is a double cylinder. Therefore, it has excellent mechanical properties, is stable, and has high productivity. In particular, the integrally molded heat-insulating support material of a cryogenic container made of an alumina fiber reinforced resin has excellent tensile strength, bending strength and respective rigidity, excellent interlaminar shear strength, and excellent heat insulating properties from the low temperature range to the normal temperature range. It is a thing.

[0024]

EXAMPLE Alumina fibers (commercial name Altex SX-11-1K) obtained by impregnating the rotating mandrel 14 for forming a cylinder with an epoxy resin in a state where the auxiliary mandrel 15 and the bolt 16 are removed from the mandrel shown in FIG. : Sumitomo Chemical Co., Ltd., fiber diameter 15 mm) is wound to form a portion corresponding to the inner cylinder. Then, the rotation is stopped, and the auxiliary mandrel 15 is fixed to both ends of the cylindrical molding die 14 with the bolts 16. The mandrel is rotated again, and the alumina fiber impregnated with the above resin is wound around the auxiliary mandrel 15 to form an outer cylinder. The central portion which is not covered by the auxiliary mold is directly wound around the surface of the inner cylinder previously wound. Thus, the integrally molded portion of the outer cylinder and the inner cylinder is formed. After standing at a predetermined temperature for a predetermined time, the bolt 16 is removed, and the auxiliary mandrel 15 is pulled out to obtain the fiber-reinforced resin integrally molded heat insulating support material shown in FIG. 1 of the present invention. A heat insulating support structure for a cryogenic container using the heat insulating support of the present invention is shown in FIGS. 2 and 3.

[Brief description of drawings]

FIG. 1 is a partially cut sectional view of an integrally molded heat insulating support material of the present invention.

FIG. 2 is a sectional view of a heat insulating support structure composed of a quadruple cylinder using two integrally formed heat insulating support materials.

FIG. 3 is a schematic side view of a heat insulating support structure for a cryogenic container.

FIG. 4 is a partially cut cross-sectional view of a mandrel used when manufacturing the integrally molded heat-insulating support material of the present invention.

[Explanation of symbols]

 1, outer cylinder part of integrally formed heat insulation support material 2, inner cylinder part of integrally formed heat insulation support material 3, central part of integrally formed heat insulation support material 4, outer cylinder part of integrally formed heat insulation support material 5, integrally formed heat insulation support material Inner cylinder part 6, central part of integrally molded heat insulating support 7, connecting jig 8, cryogenic container wall 9, mounting part side wall 10, heat insulating support 11, bogie mounting part 12, cryogenic temperature with superconducting coil Container 13, Part of cart 14, Cylindrical mandrel 15, Auxiliary mandrel 16, Bolt

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshifumi Nakano 6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd.

Claims (1)

Claims: 1. A structure in which two cylinders having different diameters are concentrically overlapped with each other, and adjacent cylinders are integrally molded at the center of the cylinder. An integrally molded heat-insulating support made of fiber-reinforced resin.