JP2006057786A - Inner tank supporting device of liquefied gas tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inner tank supporting device of a liquefied gas tank capable of reducing positional deviation and twisting force acting on a band-like load supporting body when holding an inner tank in a central part of an outer tank. <P>SOLUTION: This inner tank supporting device 1 is composed of a two-shaft supporting fitting 2 for supporting intermediate part shafts 3 in the direction in which they cross mutually and orthogonally in tip parts of a pair of flat brackets 2a protruding in the mutually opposing directions, one-shaft supporting fittings 4 arranged on both sides nipping the two-shaft supporting fitting 2 and supporting end part shafts 5 in tip parts of a pair of flat brackets 4a, and the band-like load supporting body 6 hooked on the intermediate part shaft 3 and the end part shaft 5 and formed like an endless belt. A screw rod 7 attached to the one-shaft supporting fitting 4 is connected with an outer tank side fitting 53 provided in the outer tank and an inner tank side fitting 54 provided in an inner tank bracket through a washer unit 8 composed of a first washer 8a having a projecting curved surface and a second washer 8b having a recessed curved surface to allow precessing motion and turn motion of the screw rod 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention comprises an outer tank that holds a vacuum for heat insulation, and an inner tank filled with liquefied gas, for example, liquefied hydrogen, and one end side of the outer tank side metal fitting provided inside the outer tank The other end side is connected with the inner tank side metal fitting provided in the exterior of the said inner tank, and is related with the inner tank support apparatus of the liquefied gas tank which hold | maintains the said inner tank in the center part inside the said outer tank.

  In a liquefied gas tank with a double shell insulation structure consisting of an outer tank that holds a vacuum for heat insulation and an inner tank that contains cryogenic liquefied gas, the amount of heat input from the atmosphere is reduced in order to reduce the amount of liquefied gas evaporation. Need to be reduced. Therefore, the inner tank is supported at the center of the outer tank using a band-shaped load support made of fiber reinforced plastic. As such a band-shaped load support for supporting the inner tub, for example, a support structure for a band-shaped load support in a cryostat having a configuration described later is known.

  Hereinafter, a schematic configuration of the support structure of the band-shaped load support in the cryostat according to the conventional example will be described with reference to FIG. 3 of the entire configuration explanatory diagram of the band-shaped load support having the support structure. That is, in the support structure of the band-shaped load support body 103 composed of the fiber reinforced plastic that supports the low-temperature-side supported body (corresponding to the inner tank) 102 by the room temperature side vacuum container (corresponding to the outer tank) 101, A combination body (spherical bearing) of an outer spherical ring 108 and an inner spherical ring 109 fitted to the outside of the outer spherical ring 108 is fitted to the metal pins 104 that support both ends of the body 103, and the outer peripheral surface of the combined body A band-shaped load support 103 is wound around and supported. For this reason, even if a positional deviation occurs between the fulcrums of the band-shaped load support 103, the support portion of the band-shaped load support 103 is immediately and automatically aligned. A fork 105 is fixed to the room temperature side vacuum vessel 101 and the low temperature side support 102 and supports the metal pin 104.

Therefore, according to the support structure of the band-shaped load support in the cryostat according to this conventional example, the contact portion between the band-shaped load support and the metal pin due to the positional deviation between the band-shaped load support 103 and the metal pin 104 is provided. The problem of the stress concentration which arises is solved, and the safety | security improvement of the support structure by the band-shaped load support body 103 is attained further (for example, refer patent document 1).
Utility Kaihei 5-8200

  The band-shaped load support used to support the inner tank in the central part of the outer tank assembles a liquefied gas tank with a double-shell insulation structure at atmospheric temperature in order to demonstrate excellent strength against tensile load At this time, it is necessary to assemble with high accuracy so that the tensile load acts only in the fiber direction of the band-shaped load support. However, both the outer tank that holds the heat insulation vacuum of the liquefied gas tank that has a double shell insulation structure and the inner tank that stores the cryogenic liquefied gas are manufactured into a cylindrical shape after bending and welding the flat plate. The openings at both ends of the cylindrical outer tub and the inner tub are closed by end plates. That is, these outer and inner tanks are canned products, and their dimensional accuracy is far inferior to machined products.

  Therefore, the assembly work with high accuracy so that the tensile load acts only in the fiber direction of the band-shaped load support is very complicated. If the assembly is performed while ignoring the dimensional accuracy, there is a possibility that an appropriate tensile load may not be applied due to the positional deviation between the fulcrums of the band-shaped load support or that the twist may be applied to the band-shaped load support. Furthermore, if the inner tank of the liquefied gas tank is filled with cryogenic liquefied gas, the inner tank and the band-shaped load support are thermally contracted, and the dimensional accuracy changes during assembly at atmospheric temperature. A positional shift or torsional load acts on the band-like load support, and there is a fear that an appropriate tensile load does not act on the band-shaped load support.

In the case of the support structure for the band-shaped load support according to the above-described conventional example, the inner spherical ring fitted to the outside of the outer spherical ring rotates even if the positional deviation occurs between the fulcrums of the band-shaped load support. It will be. Therefore, since the self-alignment is performed at the support portion of the band-shaped load support body, it is explained that the problem of stress concentration occurring at the contact portion between the band-shaped load support body and the metal pin due to the displacement between the fulcrums is solved. Has been. However, the contact surface between the outer spherical ring and the inner spherical ring is a metal surface and has a very large coefficient of friction in a vacuum. Therefore, even when a liquefied gas tank with a double shell insulation structure is assembled with high accuracy at atmospheric temperature, the inner spherical ring fitted to the outside of the outer spherical ring is rotated by the temperature drop due to the filling of cryogenic liquefied gas. It becomes difficult to move.
For this reason, due to the shrinkage of the inner tank and the band-shaped load support, a positional shift or a torsional load acts on the band-shaped load support, and an appropriate tensile load may not act on the band-shaped load support.

  Further, a plurality of band-shaped load supports are used for assembling a liquefied gas tank having a double shell heat insulation configuration. As mentioned above, the outer and inner tanks are canned products, and the dimensional accuracy is far inferior to machined products, so the dimension between the fulcrum at the place where the band-shaped load support is used is Is different. Therefore, in the band-shaped load support according to the conventional example, the dimensions of the fork that supports the metal pin must be determined according to the place to be used, and the fork must be machined. become.

  Therefore, the object of the present invention is to easily cope with the difference in mounting dimension caused by dimensional accuracy when an appropriate tensile load acts on the band-shaped load support when assembling a liquefied gas tank having a double shell insulation structure. An object of the present invention is to provide an inner tank support device for a liquefied gas tank that makes it possible to do this.

  In order to solve the above problems, the inner tank support device 1 for a liquefied gas tank according to the present invention is configured as follows. In other words, the inner tank support device 1 for a liquefied gas tank according to claim 1 of the present invention has an inner tank bracket in which one end side is installed outside the inner tank 52 on the outer tank side metal fitting 53 provided inside the outer tank 51. In the inner tank support device 1 for a liquefied gas tank in which the other end side is connected to the inner tank side metal fitting 54 provided on the inner tank and the inner tank 52 is held in the center of the outer tank 51, the outer tank side metal fitting 53 and the inner tank A shaft hole provided so that the central axis is perpendicular to the connecting line is formed on the tip side of the pair of flat brackets 2a, 2a protruding in opposite directions along the connecting line connecting the side metal fittings 54. A biaxial support fitting 2 that supports the intermediate shaft 3 that is disposed so that the central axes are orthogonal to each other and is removably inserted into the shaft hole, and is disposed on both sides of the biaxial support fitting 2. A shaft provided on the tip side of the flat bracket 4a A uniaxial support bracket 4 that supports an end shaft 5 that is removably inserted into the band, and a band-shaped load support 6 that is stretched over the intermediate shaft 3 and the end shaft 5 and is made of fiber-reinforced plastic. A screw rod 7 that is inserted into a rod hole provided in the outer tub side metal fitting 53 or the inner tub side metal fitting 54 and connects the uniaxial support metal fitting 4, and is externally fitted to a thread portion of the screw rod 7. The screw rod 7 includes a washer unit 8 that allows a sawtooth motion and a pivoting motion, and a nut 9 that is screwed to a projecting end of the screw portion of the screw rod 7 from the washer unit 8. Is.

Further, in the inner tank support device 1 for a liquefied gas tank according to claim 2 of the present invention, the washer unit 8 has a concave curved surface of the first washer 8a when the first washer 8a has a concave curved surface. When the first washer 8a has a convex curved surface, the second washer 8b has a concave curved surface that slidably contacts the convex curved surface of the first washer 8a. It is characterized by.

  The liquefied gas tank inner tank support device 1 according to claim 3 of the present invention is the liquefied gas tank inner tank support device 1 according to claim 2, wherein the curved surface of the first washer 8a and the second washer 8b. Further, a coating layer made of a low friction material is formed.

  In the inner tank support device 1 for a liquefied gas tank according to claims 1 to 3 of the present invention, even if a displacement occurs in the fiber direction of the connecting line of the inner tank support device 1 and the band-shaped load support, the band-shaped load The axis center line passing through the center of the intermediate shaft and the end shaft supporting the support and the center line passing through the screw rod fixing portion coincide with each other by the action of the washer unit 8 that allows the screw rod 7 to move and rotate. To do. Therefore, according to the inner tank support device 1 of the liquefied gas tank according to claims 1 to 3 of the present invention, an appropriate tensile load acts on the band-shaped load support. Moreover, since the distance between the connection of the screw rod 7 of the inner tank support apparatus 1 can be adjusted by adjusting the screwing amount of the nut to the screw rod 7, the outer tank side metal fitting 53 and the inner tank side metal fitting 54 can be screwed. There is no need to manufacture according to the distance between the connecting rods. Furthermore, since the band surfaces of the band-shaped load support body supported by the biaxial support fitting 2 are orthogonal, even if a positional deviation or a torsional load is applied, the positional deviation or the torsional load is smaller than in the conventional example.

  In the inner tank support device 1 for a liquefied gas tank according to claim 3 of the present invention, a coating layer made of a low friction material is formed on the curved surfaces of the first washer 8a and the second washer 8b of the washer unit 8, Even if the inner tank support device 1 becomes a low temperature in a vacuum, the direction of the screw rod 7 is changed with a small force and can be rotated. Therefore, according to the inner tank support device 1 of the liquefied gas tank according to claim 3 of the present invention, the fiber direction of the band-shaped load support of the inner tank support device 1 is the axis of the tensile load on which the inner tank support device 1 acts. An appropriate tensile load without twisting is applied to the band-shaped load support which is easily matched.

  Hereinafter, an inner tank support device 1 for a liquefied gas tank according to the present invention will be described with reference to the accompanying drawings. FIG. 1A is a schematic cross-sectional view of a liquefied gas tank having a double shell insulation structure assembled using the inner tank support device 1 according to the present invention, and FIG. FIG. 2 is an enlarged view and FIG. 2 is an explanatory diagram of the configuration of the inner tank support device 1 for a liquefied gas tank according to the present invention.

  Reference numeral 50 shown in the figure is a liquefied gas tank having a double shell heat insulation configuration. The liquefied gas tank 50 includes an outer tank 51 that holds a heat insulating vacuum, and an inner tank 52 that stores a cryogenic liquefied gas is provided at the center of the outer tank 51. The inner tub 52 is connected to an outer tub side metal fitting 53 provided inside the outer tub 51 at one end side and to the inner tub side metal fitting 54 provided outside the inner tub 52, respectively. It is supported by the inner tank support apparatus 1 which becomes the structure to perform. In addition, what surrounds the said inner tank 52 is the heat insulation layer 55 which consists of a laminated body of aluminum foil and glass fiber cloth, for example.

  As shown in FIG. 2, the inner tank support device 1 includes a biaxial support fitting 2. The biaxial support fitting 2 includes a pair of flat plate brackets 2a and 2a protruding in opposite directions, and a shaft hole is provided on the tip side of each flat plate bracket 2a. An intermediate shaft 3 is removably inserted into each shaft hole, and the intermediate shafts 3 are configured to be orthogonal to each other. Male screws are threaded on both ends of the intermediate shaft 3, and washers 3a are fitted to these male screws, and nuts 3b are threaded.

  Further, a pair of uniaxial support fittings 4 with a pair of protruding flat-plate brackets 4a facing the biaxial support fitting 2 side are disposed at both side positions sandwiching the biaxial support fitting 2. A shaft hole is provided on the front end side of the flat bracket 4a of each uniaxial support bracket 4, and the end shaft 5 is removably inserted into the shaft hole. A male screw is threaded at both ends of the end shaft 5 in the same manner as the intermediate shaft 3, and a washer 5 a is fitted to the male screw and a nut 5 b is threaded. A band-shaped load support 6 made of fiber reinforced plastic (alumina fiber FRP, carbon fiber FRP, glass fiber FRP, or the like) is hung across the intermediate shaft 3 and the end shaft 5. In this embodiment, male screws are threaded on both ends of the intermediate shaft 3 and the end shaft 5, but the intermediate shaft 3 and the end shaft 5 can be replaced with metal pins according to the conventional example.

  Further, a screw rod 7 protruding in the opposite direction of the flat bracket 4a is attached to the uniaxial support bracket 4 by a nut 7a, and the tip of the screw rod 7 is connected to the outer tank side metal 53 or the inner tank side metal. 54 is inserted into a rod hole provided in 54. A washer unit 8 having a configuration which will be described later and which allows a sawtooth motion and a rotational motion of the screw rod 7 is externally fitted to a male screw portion threaded on the distal end side of the screw rod 7. Then, a nut 9 having a function of preventing loosening is screwed onto the projecting end of the threaded portion of the threaded rod 7 from the washer unit 8, so that the inner tank support device 1 can be moved through the threaded rod 7. The tank side metal fitting 53 and the inner tank side metal piece 54 are connected to each other.

  In the case of this embodiment, the outer tub side metal fitting 53 is welded to a plurality of locations inside the outer tub 51, and a plurality of inner tub side metal fittings 54 paired with the outer tub side metal fitting 53 are formed into an inner tub bracket 56. It is welded to. And from the point of dimensional accuracy of the outer tub 51 and the inner tub 52, in the state where the inner tub 52 is assembled in the central portion inside the outer tub 51, the outer tub side metal fitting 53, the inner tub side metal fitting 54, The intervals between are different. However, the difference in the distance between the outer tub side fitting 53 and the inner tub side fitting 54 is easily absorbed by adjusting the screwing amount of the nut 9 into the screw rod 7.

  The washer unit 8 includes a first washer 8a having a concave curved surface, and a second washer 8b having a curved surface having the same curvature radius as the concave curved surface of the first washer 8a and having a convex curved surface slidably contacting the concave curved surface. It is configured. A coating layer (not shown) made of a low friction material is formed on the surfaces of the concave curved surface of the first washer 8a and the convex curved surface of the second washer 8b. This low friction material is made of a molybdenum disulfide-based material having a function capable of maintaining a low friction state even in a vacuum and at a low temperature (for example, −269 ° C.), and has a thickness of, for example, 15 to 20 μm. Is enough. In this embodiment, the first washer 8a is provided with a concave curved surface and the second washer 8b is provided with a convex curved surface. On the contrary, the first washer 8a has a convex curved surface, Even if the washer 8b is provided with a concave curved surface, the same function can be exhibited.

  Hereinafter, the operation mode of the inner tank support device 1 having the above-described configuration of the present invention will be described. In the inner tank support device 1 of this liquefied gas tank, even if a positional deviation occurs in the fiber direction of the connecting line of the inner tank support device 1 and the band-shaped load support 6, an intermediate portion that supports the band-shaped load support 6. Due to the axial center line passing through the center of the shaft 3 and the end shaft 5 and the function of the washer unit 8 that allows the sliding motion and the rotational motion of the threaded rod 7, the threaded rod 7 performs the sliding motion and the radial direction. Since it rotates around the axis passing through the center, the center line passing through the screw rod fixing portion coincides. Therefore, according to the inner tank support device 1 of the liquefied gas tank according to the embodiment of the present invention, an appropriate tensile load without twisting acts on the band-shaped load support 6.

  Moreover, in the inner tank support device 1 of the liquefied gas tank according to the embodiment of the present invention, the screw rod 7 of the inner tank support device 1 is adjusted by adjusting the screwing amount of the nut 9 into the screw rod 7 of the inner tank support device 1. The distance between connections can be adjusted. Therefore, according to the inner tank support device 1 of the liquefied gas tank according to the embodiment of the present invention, unlike the support structure according to the conventional example, the inner tank side metal fitting 54 and the outer tank side metal fitting 53 are set at a distance between the connection of the screw rods 7. There is no need to manufacture accordingly. The two central shafts 3 supported by the biaxial support bracket 2 are oriented orthogonally to each other, and the band surfaces of the band-shaped load support 6 are orthogonal to each other. Even if a load is applied, the positional deviation and the torsional load are smaller than those of the conventional example, so that the possibility of damaging the band-shaped load support 6 is reduced.

  Furthermore, in the inner tank support device 1 of the liquefied gas tank according to the embodiment of the present invention, the coating layer made of a low friction material is formed on the surfaces of the concave curved surface of the first washer 8a and the convex curved surface of the second washer 8b of the washer unit 8. Is formed and the sliding is smooth, so that the direction of the screw rod can be changed and rotated with a small force even when the inner tank support device 1 becomes low temperature in a vacuum. Therefore, according to the inner tank support device 1 of the liquefied gas tank according to the embodiment of the present invention, the fiber direction of the band-shaped load support 6 of the inner tank support device 1 is easy to be a straight line connecting the connections of the inner tank support device 1. In addition, the band-like load support 6 is not subjected to positional displacement or torsional load.

  In addition, in the above form, the case where the inner tank support apparatus 1 of the liquefied gas tank was provided with the single biaxial support metal fitting 2 was demonstrated as an example. However, since two or more biaxial support metal fittings 2 may be provided, it is not limited to the structure which concerns on the said form. Moreover, since the inner tank support apparatus 1 which concerns on the said form is only one specific example, the design change etc. in the range which does not deviate from the technical idea of this invention are free.

(A) is typical sectional drawing of the liquefied gas tank used as the double shell heat insulation structure assembled using the inner tank support apparatus 1 which concerns on this invention. (B) is an enlarged view of the attachment part of the inner tank support apparatus 1. FIG. It is a structure explanatory view of the inner tank support device 1 of the liquefied gas tank concerning the present invention. It is related with a prior art example, and is a whole block explanatory drawing of the band-shaped load support body provided with the support structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner tank support apparatus 2 ... Biaxial support bracket, 2a ... Flat plate bracket 3 ... Middle part axis | shaft, 3a ... Washer, 3b ... Nut 4 ... Uniaxial support bracket 4a ... Flat plate bracket 5 ... End shaft 5a ... Washer 5b ... Nut 6 ... Band-shaped load support 7 ... Screw rod 8 ... Washer unit, 8a ... 1st washer, 8b ... 2nd washer 9 ... Nut 51 ... Outer tank, 52 ... Inner tank, 53 ... Outer tank side metal fitting, 54 ... Inner tank side Metal fitting 55 ... heat insulation layer, 56 ... tank bracket

Claims (3)

One end of the outer tub side metal fitting (53) provided inside the outer tub (51) and the other end of the inner tub side metal fitting (54) provided on the inner tub bracket arranged outside the inner tub (52) The inner tank support device of the liquefied gas tank, each of which is connected to each other, and holds the inner tank (52) in the center of the outer tank (51),
The inner tank support device (1) is disposed along a connecting line connecting the outer tank side metal fitting (53) and the inner tank side metal fitting (54), respectively, and a biaxial support metal fitting (2 ), A pair of uniaxial support brackets (4) (4) connected to the outer tub side metal fitting (53) and the inner tub side metal fitting (54), respectively, via a screw rod (7), and the biaxial support It consists of a pair of band-shaped load supports (6) (6) that connect the bracket (2) and the uniaxial support bracket (4) (4),
The biaxial support bracket (2) includes a pair of flat brackets (2a) and (2a) projecting oppositely along the connecting line, and the flat brackets (2a) are orthogonal to each other on the connecting line. The middle shaft (3) is removably inserted into the shaft hole,
Each uniaxial support bracket (4) includes a flat plate bracket (4a) that faces the flat plate bracket (2a) of the biaxial support bracket (2), and a shaft hole provided in the flat bracket (4a). The end shaft (5) is detachably fitted,
Each of the band-shaped load supports (6) is straddled across the intermediate shaft (3) and the end shaft (5), and the screw rod (7) is allowed to have a slit motion and a rotational motion at one end thereof. An apparatus for supporting an inner tank of a liquefied gas tank, comprising a washer unit (8). The washer unit (8) is a second washer (8b) having a convex curved surface that slidably contacts the concave curved surface of the first washer (8a) when the first washer (8a) has a concave curved surface. When the first washer (8a) has a convex curved surface, the first washer (8a) is a second washer (8b) having a concave curved surface slidably contacting the convex curved surface of the first washer (8a). The inner tank support apparatus of the liquefied gas tank of description. The inner tank of the liquefied gas tank according to claim 2, wherein a coating layer made of a low friction material is formed on the curved surfaces of the first washer (8a) and the second washer (8b). Support device.

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