JP7178549B2 - Anchor strap structure - Google Patents

Description

The present invention relates to, for example, an anchor strap structure, and more particularly to an anchor strap structure for a cryogenic tank for storing liquefied gas.

FIG. 1 is a front partial cross-sectional view of a typical cryogenic tank. As a cryogenic tank for storing a cryogenic liquid such as liquid hydrogen, an inner tank as shown in FIG. A double-shell cryogenic tank formed from an outer tank is known.

Most cryogenic tanks 100 of this type are cylindrical, and typical floating-floor tanks have a spherical roof, and are mounted on piles buried in the ground at a predetermined distance from the ground. A concrete base 3 is provided, a bottom structure 5 is provided on the base 3, and the inner tank 1 is seated on the bottom plate structure 5 to support the load. , and an outer tank 2 is provided to cover this and form a cold insulating layer of a predetermined thickness. Between the side plate 30 of the inner tank 1 and the base 3, a large number of metal anchor straps 4 are provided on the outer periphery of the side plate 30 at intervals of about 1 m in order to prevent the cryogenic tank 100 from floating and falling.

An example of this type of anchor strap is the one shown in Patent Document 1.

The invention described in Patent Document 1 aims to reduce the amount of 9% nickel steel used to reduce costs. The plate is attached by welding, and a dead anchor is attached to the surface by welding. The upper end of the PC (Prestressed Concrete) steel wire is fixed to the dead anchor, and the lower end of the PC steel wire is attached to the outer tank. Anchor straps are formed by passing the PC steel wires through bolt holes provided in the bottom plate and connecting the lower ends of the PC steel wires to PC anchors embedded in the bottom surface of the bottom plate of the outer tank.

The PC steel wire is stipulated in JISG3536, and when an earthquake occurs, it is generated by connecting the dead anchor attached to the side plate of the inner tank and the PC anchor embedded in the bottom plate of the outer tank with the required tension applied. The strength of the PC steel wire in the tensile direction prevents the inner tank from rising.

JP 2009-250291 A

By the way, in the technical idea described in the above-mentioned Patent Document 1, although cost reduction and strength are considered, reduction of the amount of heat entering from the base to the cryogenic tank through the anchor strap is not considered. Anchor straps installed in cryogenic tanks such as liquid hydrogen must have both sufficient tensile axial rigidity to prevent floating and overturning and low thermal conductivity to reduce the amount of heat that enters.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low thermal conductivity anchor strap structure for preventing the cryogenic tank from floating and overturning.

Another object of the present invention is to provide a reasonable structure of fiber-reinforced plastic and a method of joining it to metal for reducing the amount of heat entering from the anchor strap structure.

In order to solve the above problems, the present inventors have developed a low thermal conductivity anchor strap structure that suppresses the heat input from the base to the cryogenic tank. That is, the present inventors focused on adopting a structure that reduces heat infiltration by using fiber-reinforced plastic, which has a lower thermal conductivity than metal, for the anchor strap. When metal and fiber reinforced plastic are used together, the joining method is mechanical joining using bolts and nuts, adhesive joining, or hooking with a hook.

Tensile force acts on the anchor strap during operation of the cryogenic tank, but in mechanical joints using bolts and nuts, the force is transmitted through surface pressure around the bolt holes of the bolts and fiber-reinforced plastic. Therefore, it is necessary to add an oblique lamination that is effective against the surface pressure load to the fiber reinforced plastic of the bolted joint. As the heat input increases, the heat insulation performance decreases. Therefore, the present inventors have adopted a structure in which the plate thickness of the fiber-reinforced plastic is thickened only at the joints with the metal, and the plate thickness of other general portions is thinned according to the required tensile axial rigidity. In order to prevent the decrease of Then, the fiber-reinforced plastic parts were divided into a joint part, a rubbed part, and a general part. Here, when the fibers are tilted with respect to the load direction in order to change the plate thickness of the fiber-reinforced plastic on which the tensile force acts, gentle I came to the realization that it was necessary to slide on the slope.

The rubbing portion is a portion where the plate thickness becomes thinner as it moves away from the joint, and we have come to realize that it is necessary for the slope to be gentle. ing.

However, if the plate thickness of the joint portion and the plate thickness of the general portion are rubbed at 1:100, for example, the rubbed portion is required over the entire length of the fiber reinforced plastic, resulting in an increase in the cross-sectional area. Insulation performance deteriorates. In addition, the fact that most of the entire length of the fiber-reinforced plastic becomes the rubbed portion has the disadvantage of taking time and effort in manufacturing and increasing the cost.

Therefore, in the present invention, in order to reduce the amount of heat that penetrates from the anchor strap structure, a unique structure is used for joining fiber reinforced plastic and metal.

Specifically, a first aspect of the present application is a low thermal conductivity anchor strap structure characterized in that a fiber reinforced plastic having a lower thermal conductivity than metal is provided at a connecting portion between the base structure and the standing structure. is realized as

The term “base structure” refers to a base structure, for example, a floor plate structure of a cryogenic tank, a bottom structure formed on the floor plate structure, or a structure including a base formed thereon.

The term "upright structure" refers to a wall structure that is set up (substantially) vertically, and includes, for example, an inner tank side plate or an outer tank side plate of a cryogenic tank.

According to a second aspect of the present application, in the first aspect, a metal is further provided at the connecting portion between the base structure and the standing structure, and the fiber-reinforced plastic and the metal are joined by bolts and nuts. It is characterized by at least one of mechanical bonding, adhesive bonding, and bonding in which mechanical bonding and adhesive bonding are combined.

According to a third aspect of the present application, in the first aspect, a metal is further provided at the connecting portion between the base structure and the erected structure, and the fiber-reinforced plastic and the metal are joined together using the fiber-reinforced plastic. is hooked on the metal.

According to a fourth aspect of the present application, in the second or third aspect, the fiber-reinforced plastic has a joint portion to be joined to the metal, and a sliding portion and/or It is characterized by having a general portion which is thinner than the joint portion and whose thickness does not change.

According to a fifth aspect of the present application, in the fourth aspect, the joint portion is provided with a through hole for the bolt to pass through.

A sixth aspect of the present application is characterized in that, in the fifth aspect, the through hole has substantially the same diameter as the bolt.

A seventh aspect of the present application is characterized in that, in the fourth aspect, the joint portion has a hook shape to be hooked on the metal.

According to an eighth aspect of the present application, in the seventh aspect, the metal is provided with a hole and/or a protrusion for hooking the joint portion.

According to a ninth aspect of the present application, in the fifth aspect, the fiber orientation in the joint portion is a fiber direction equal to the axial direction of the low thermal conductivity anchor strap structure and an oblique direction for preventing shear failure of the fiber reinforced plastic. It is characterized by having a cross layer.

According to a tenth aspect of the present application, in the ninth aspect, an angle of the oblique lamination with respect to the axial direction of the joint portion is approximately ±45°.

An eleventh aspect of the present application is characterized in that, in the fourth aspect, the fiber direction is substantially symmetrical with respect to the plate thickness center line of the fiber-reinforced plastic.

A twelfth aspect of the present application is any one of the fourth to sixth and ninth to eleventh aspects, wherein the fiber-reinforced plastic has a bundle structure in which two or more sheets are laminated in the plate thickness direction. .

According to a thirteenth aspect of the present application, in the fifth aspect, the joint portion has a joint plate made of metal sandwiched from both sides in a butted portion between the metal and the fiber-reinforced plastic, and the metal, the fiber-reinforced plastic, Each of the joint plates is characterized by having a structure joined by the bolts/nuts and/or adhesive.

A fourteenth aspect of the present application is characterized in that the nut is tightened with a predetermined torque in the thirteenth aspect.

According to a fifteenth aspect of the present application, in the second aspect, the joint portion has joint plates made of fiber-reinforced plastic sandwiched from both sides in the abutted portion between the metal and the fiber-reinforced plastic, each of which is attached to the bolt. It is characterized by having a structure joined by a nut and/or an adhesive.

By using fiber-reinforced plastic, which has a lower thermal conductivity than metal, for the anchor strap structure, it is possible to reduce the amount of heat that enters the tank inner tank from the base.

By joining fiber-reinforced plastic and metal by various methods, it is possible to establish a rational anchor slap structure with the right material in the right place.

By adopting a bundle structure, the thickness difference between the joint part and the general part is reduced, and it is possible to reduce the total cross-sectional area of the fiber-reinforced plastic by reducing the length of the rubbing part while ensuring a gentle slope. Therefore, separation between layers can be prevented, and the amount of heat that enters can be reduced.

Compressive force is introduced in the plate thickness direction of the fiber-reinforced plastic by sandwiching the fiber-reinforced plastic between highly rigid metal joint plates and applying torque to the bolt. Due to this effect, microscopic buckling of the fibers is suppressed, and the surface pressure strength around the bolt holes can be improved. Therefore, a design that reduces the number of bundles in the joint becomes possible, and in addition to the above, it becomes possible to reduce the amount of incoming heat.

The surface pressure strength of the fiber-reinforced plastic is maximized when the diameter of the bolt through-hole of the fiber-reinforced plastic and the bolt are the same. Therefore, it is possible to reduce the amount of incoming heat as described above.

1 is a front partial cross-sectional view of a typical cryogenic tank; FIG. 1 is a front view of an anchor strap 4 according to one embodiment of the invention; FIG. Figure 2B is a side view of Figure 2A; FIG. 4 is a diagram showing an example of a lamination configuration of a one-bundle structure used for the anchor strap 4 according to the present invention; FIG. 4 is a diagram showing an example of a partial diffusion diagram of the laminated structure shown in FIG. 3; FIG. 4 is a view showing a fiber-reinforced plastic portion of an anchor strap structure in which a plurality of 1-bundle structures shown in FIG. 3 are bundled and adhered; FIG. 6 is a view showing an example of a joint between the fiber-reinforced plastic and the metal plate shown in FIG. 5; FIG. 5 is a diagram showing an example of a joint between fiber-reinforced plastic and a metal plate according to another embodiment of the present invention; FIG. 5 is a diagram showing a structure for hooking fiber-reinforced plastic to a hole made in metal according to another embodiment of the present invention. FIG. 10 is a diagram showing another example of a connecting portion between fiber-reinforced plastic and a metal plate according to yet another embodiment of the present application;

Embodiments will be described below with reference to the drawings.

<Overview of anchor strap>
2A is a front view of an anchor strap 4 according to one embodiment of the invention, and FIG. 2B is a side view of FIG. 2A.

Anchor strap 4 consists of first metal plate 11 connected to cryogenic tank 100, second metal plate 12 connected to base 3, and first metal plate 11 and second metal plate 12. Fiber reinforced plastics 10 connected via a first joint portion 13 and a second joint portion 14, respectively.

Specifically, the anchor strap 4 includes a first joint portion 10-1, a second joint portion 10-5, a first rubbing portion 10-2, a second rubbing portion 10-4, and a general portion 10-3, a first metal plate 11 with one end attached to the side plate 30, a second metal plate 12 embedded in the base 3, and the first metal plate 11 A first joint portion 13 that connects the first joint portion 10-1, and a second joint portion 14 that connects the second joint portion 10-5 and the second metal plate 12, It has rubbed portions 10-2 and 10-4 at both ends of the general portion 10-3, the thickness of which increases toward the first joint portion 13 and the second joint portion .

The first joint portion 13 is a pair of first joint plates 13-1 and 13-2 sandwiched so as to cover both main surfaces of the first joint portion 10-1 and the end portion of the first metal plate 11. Then, the first joint portion 10-1, the first metal plate 11, the first joint portion 10-1, the first metal plate 11, and the second It has a bolt 17a, a washer 18a, and a nut 19a as means for fastening a pair of joint plates 13-1 and 13-2.

The second joint portion 14 is a pair of second joint plates 14-1 and 14-2 sandwiched so as to cover both main surfaces of the second joint portion 10-5 and the end portion of the second metal plate 12. Then, the second joint portion 10-5, the second metal plate 12, the second joint portion 10-5, the second metal plate 12, and the second It has a bolt 17b, a washer 18b and a nut 19b as second fastening means for fastening the pair of two joint plates 14-1 and 14-2.

The hammer head 15 is fixed to the first metal plate 11 and the pad plate 16 is fixed to the side plate 30 of the cryogenic tank 100, both of which are members for connecting the anchor strap 4 and the side plate 30.

The general portion 10-3, the rubbed portions 10-2 and 10-4, the first joint portion 10-1 and the second joint portion 10-5 are preferably made of fiber reinforced plastic. Stainless steel, for example, can be used as the material for the first metal plate 11 and the second metal plate 12 .

<Main part of anchor strap 4>
<Bundle structure>
FIG. 3 is a conceptual cross-sectional view showing an example of a lamination configuration of a one-bundle structure used for the anchor strap 4 according to one embodiment of the present invention. Incidentally, bolt holes are omitted in FIG.

One bundle includes a general portion 10-3 of UD 0° layers 20-1 to 20-10 oriented in the same direction as the axial direction of the anchor strap, both ends having a rubbed portion 10-2 and a joint portion 10-1 (Fig. at the right end). In the joint portion 10-1, in addition to the UD 0° layers 20-1 to 20-10, UD +45° layers 21-1 to 21- as a second layer in which the fiber orientation (angle θ1) is rotated +45°, for example. 8, and the UD 0° layers 20-1 to 20-10 are the UD-45° layers 22-1 to 22-8 as a third layer in which the fiber orientation (angle θ2) is rotated by -45°, for example. It has a structure in which two sheets are stacked and inserted.

Here, UD is an abbreviation for Uni-Direction and means having unidirectionality.

The UD+45° layers 21-1 to 21-8 and the UD−45° layers 22-1 to 22-8 are arranged so that the length in the longitudinal direction from the inner layer to the outer layer is the slope of the rubbed portion 10-2. formed to be shorter along the By configuring such a bundle structure, the thickness difference between the joint portion and the general portion is reduced, so that the length of the rubbing portion can be shortened while ensuring a gentle slope.

The arrangement and total number of the second layers 21-1 to 21-8 and the third layers 22-1 to 22-8 are the first joint portion 10-1, the second joint portion 10-5, the first In the rubbed portion 10-2 and the second rubbed portion 10-4, the cross-sectional shape is set to be line symmetrical with respect to the plate thickness center line. As a result, heat is evenly transferred by hot pressing during manufacturing, and warping and deformation are less likely to occur. As a result, it is possible to suppress the occurrence of harmful deformation that hinders bundling.

In the above, the total thickness of the ±45° layers is preferably set to be 40% or more of the total thickness of the joint.

FIG. 4 is a conceptual diagram showing an example of a partial diffusion diagram of one bundle shown in FIG. UD0° layer 20-1, UD+45° layer 21-1, UD-45° layer 22-1, UD0° layer 20-2, UD+45° layer 21-2, UD-45° layer 22-2 from the top of FIG. , UD0° layer 20-3, . . . The lengths of the UD+45° layers 21-1, 21-2, . . . and the UD−45° layers 22-1, 22-2, . is different.

UD0° layers 20-1, 20-2, 20-3, . . . , UD+45° layers 21-1, 21-2, . 10-1 has bolt holes 20-1a, 21-1a, 22-1a, 21-2a, 22-2a, 20- 3a, .

Here, when the angles .theta.1 and .theta.2 indicating a single direction with respect to the longitudinal direction are +45.degree.

<Bundle type fiber reinforced plastic>
FIG. 5 is an example of a side view in which a plurality of one-bundle fiber-reinforced plastics shown in FIG. 3 are laminated (the figure shows an example of 10 sheets, but the number is not limited to 10 sheets). Incidentally, bolt holes are omitted in FIG.

The bundle-type fiber-reinforced plastic 10 is adhered with an adhesive after each bundle 25-1, 25-2, . . . , 25-10 is molded. Each of the bundles 25-1, 25-2, . . . , 25-10 has the structure shown in FIG. At this time, the thickness and length ratios are not limited to those shown in FIGS.

<Junction>
FIG. 6 is an example of a partially enlarged cross-sectional view showing the vicinity of the first joint 13 that connects the bundle-type fiber-reinforced plastic 10 and the first metal plate 11 shown in FIG.

The first joint portion 10-1 of the bundle-type fiber-reinforced plastic 10 and the end portion of the first metal plate 11 abut against each other, and the pair of first joint plates 13-1 and 13-2 are used to form the first joint. While being sandwiched between the portion 10-1 and the first metal plate 11 so as to cover both main surfaces thereof, these are fastened together with a bolt 17a, a washer 18a, and a nut 19a. The first joint plates 13-1 and 13-2 compress the bundle-type fiber-reinforced plastic 10 by tightening the nut 19a with a predetermined torque. This improves the surface pressure strength around the bolt holes of the joints 10-1 and 10-5. Therefore, by applying a torque, it becomes possible to design the number of bundles to be reduced, and to reduce the amount of heat that enters.

The bolt 17a and nut 19a are preferably tightened with a torque that does not break the bundle-type fiber-reinforced plastic. The same applies to the bolt 17b, washer 18b, and nut 19b in the second joint 14. As shown in FIG.

Next, the action and operation of the anchor strap according to the embodiment of the present application configured as described above will be described.

In general, the anchor strap is subjected to tensile force during operation of the cryogenic tank. In mechanical joints using bolts and nuts, force is transmitted through surface pressure around the bolt holes of the bolt and fiber-reinforced plastic. At this time, it is necessary to add an oblique lamination that is effective against the surface pressure load to the fiber reinforced plastic of the bolted portion. increases, and the heat input increases, resulting in a decrease in thermal insulation performance.

In one embodiment of the present application, by adopting the above configuration, the plate thickness of the fiber-reinforced plastic is increased only at the joints with the metal, and the plate thickness of other general portions is reduced according to the required tensile axial rigidity. The use of fiber-reinforced plastic, which has a lower thermal conductivity than metal, reduces the amount of heat entering the tank from the base.

In the above anchor strap structure, the fiber reinforced plastic and the metal are joined by various methods to provide an anchor strap structure that rationally changes its cross section according to the generated force.

In addition, by adopting the above-mentioned bundle structure, the thickness difference between the joint part and the general part is reduced, and the total cross-sectional area of the fiber-reinforced plastic is reduced by reducing the length of the rubbing part while ensuring a gentle slope. Therefore, it is possible to prevent separation between layers and reduce the amount of heat that enters.

Furthermore, in the anchor strap structure described above, by sandwiching the fiber-reinforced plastic between metal plates and applying torque to the bolt, it is possible to suppress microscopic buckling of the fiber and improve surface pressure strength around the bolt hole. Therefore, a design that reduces the number of bundles in the joint becomes possible, and in addition to the above, it becomes possible to reduce the amount of incoming heat.

Considering that the surface pressure strength of fiber-reinforced plastic is maximized when the diameter of the bolt through-hole of the fiber-reinforced plastic and the bolt are the same, it is possible to reduce the amount of heat intrusion by adopting the anchor strap structure described above. .

Furthermore, as described above, in one embodiment of the present application, the fiber-reinforced plastic portion is divided into the joint portion, the rubbed portion, and the general portion, and then the plate thickness of the fiber-reinforced plastic on which the tensile force acts is changed. rice field. Since the fibers are inclined with respect to the load direction and the structure is rubbed with a gentle slope to avoid the separation of the layers due to the generation of the force component in the direction perpendicular to the load, the above-mentioned structure is adopted, so the overall length of the fiber reinforced plastic As a result, it is possible to prevent the increase in cross-sectional area and decrease in heat insulation performance, and to reduce the manufacturing labor due to the fact that most of the entire length of the fiber reinforced plastic becomes the rubbed portion. can be reduced, and cost reduction can be realized.

Overall, one embodiment of the present application provides a rational fiber-reinforced plastic structure for reducing the amount of heat that enters through the anchor strap structure.

Next, another embodiment of the present application will be described. In the following description, the same parts as in the above-described embodiment are replaced with the description in the embodiment, and the description is omitted.

FIG. 7 is a diagram showing another example of a joint between fiber-reinforced plastic and a metal plate according to another embodiment of the present application.

<Junction 2>
The difference between the joint portion 13 shown in FIG. 6 and the joint portion 13′ shown in FIG. , 13-2′ are adhesively bonded with an adhesive 200. FIG.

That is, the first joint plates 13-1′ and 13-2′ are connected while the first joint portion 10-1′ of the bundle-type fiber-reinforced plastic 10 and the end portion of the first metal plate 11 are butted against each other. When sandwiched so as to cover both main surfaces of the first joint portion 10-1′ and the end portion of the first metal plate 11 as a pair, the first joint portion 10-1′ and the first joint plate An adhesive 200 is applied to at least one of the surfaces with which the pairs of 13-1′ and 13-2′ are in contact (this figure shows a mode in which the adhesive 200 is applied to both of the contacting surfaces). , bolts 17a, washers 18a and nuts 19a fasten the first metal plate 11 and the pair of first joint plates 13-1' and 13-2'. Even with such a structure, the same effect as that of the joint shown in FIG. 6 can be obtained.

FIG. 8 is a diagram showing an example of a connecting portion between fiber-reinforced plastic and a metal plate according to another embodiment of the present application.

<Connecting part 1>
The difference between the joining portion 13 shown in FIG. 6 and the connecting portions 300, 301 shown in FIG. It is connected to through holes 11a' and 12a' formed in the .

As shown in FIG. 8, in this embodiment, both end portions 10b' and 10c' formed at both ends of a general portion 10a' of a bundle-type fiber-reinforced plastic 10' and metal plates 11' and 12' It has a hook shape that can be hooked on the through holes 11a' and 12a' respectively formed thereon. With this shape, both ends 10b' and 10c' of the bundle-type fiber-reinforced plastic 10' are connected by penetrating through holes 11a' and 12a' formed at the ends of the metal side plates 11' and 12'. state is retained. Even with such a structure, the same effect as that of the joint shown in FIG. 6 can be obtained. In the above description, the shapes of the both ends 10b' and 10c' are described as being hook-shaped, but the shape is not limited to the hook-shape, and the shape can be hooked to the through-holes 11a' and 12a'. Any shape, such as a hook shape or an L shape, may be used as long as it can be connected and maintain this connected state.

FIG. 9 is a diagram showing another example of a connecting portion between fiber-reinforced plastic and a metal plate according to still another embodiment of the present application.

<Connecting part 2>
The difference between the connecting portions 300' and 301' shown in FIG. 9 and the connecting portions 300 and 301 shown in FIG. , both ends 10b'' and 10c'' of the fiber-reinforced plastic 10' are hooked.

As shown in FIG. 9, in the present embodiment, both ends 10b'' and 10c'' of the bundle-type fiber-reinforced plastic 10' are connected to projections 110 and 120 formed at the ends of metal plates 11' and 12'. Each has a hook shape that can be hooked on. By having this shape, both ends 10b'' and 10c'' of the bundle-type fiber-reinforced plastic 10' are hooked on the projections 110 and 120 formed at the ends of the metal side plates 11' and 12', thereby connecting them. state is retained. Therefore, even in such a structure, an effect similar to that of the joint shown in FIG. 6 can be obtained. In the above description, the shape of the both end portions 10b'' and 10c'' is described as a hook shape, but the shape is not limited to the hook shape, and is connected by being caught by the projections 110 and 120. , any shape such as a hook shape or an L shape may be used as long as it can maintain this connected state.

It should be noted that the above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto, and can be modified in various ways without departing from the scope of the invention. It is possible. For example, the fiber directions of the joint are not limited to 0° and ±45°, and 90° layers may be included. Moreover, the use of the UD material is not limited to the use of the cloth material, and lamination of the cloth material is also possible. Further, the plate thickness of the metal plate and the plate thickness of the bundle anchor strap 10 do not necessarily have to be the same. Also, the angles of 0°, ±45°, 90°, etc. may be substantially 0°, ±45°, and 90°, respectively (the same applies to other angles).

Further, for example, in the above description, the structure provided with the rubbing portion and the general portion was exemplified, but as long as the intrusion heat is within the allowable range, a structure having only the laminated structure of the joint portion without the rubbing portion and the general portion can be used. good too.

The structure according to the present invention can be manufactured industrially and can be used for commercial transactions, so it has economic value and can be used in various industries such as the energy industry and the construction industry. It is an invention that can For example, it is considered possible to use it as a tensile member such as a hanging member for the inner tank of a double-shell cryogenic tank. By selecting an appropriate number of bundles according to the load, it is possible to reduce the amount of incoming heat compared to steel materials.

REFERENCE SIGNS LIST 1 inner tank 2 outer tank 3 base 4 anchor strap 5 bottom structure 10, 10', 10'' bundle-type fiber reinforced plastic (resin plate)
10-1 First joint portion 10-2 First rubbed portion 10-3 General portion 10-4 Second rubbed portion 10-5 Second Second joint parts 10-2, 10-4 ... rubbing parts 10-3, 10a' ... general parts 11, 11' ... first metal plates 12, 12' ... second metal Plates 13, 13' First joint portion 14 Second joint portion 13-1, 13-2 First joint plate 14-1, 14-2 Second joint plate Joint plates 17a, 17b Bolts 18a, 18b Washers 19a, 19b Nuts 20-1 to 20-10 UD0° layer (first resin layer)
21-1 to 21-8 ... UD + 45 ° layer (second resin layer)
22-1 to 22-8 UD-45° layer (third resin layer)
25 Laminated plate 30 Side plate 100 Cryogenic tank 200 Adhesive 300, 300', 301, 301' Connecting portion

Claims (15)

Fiber-reinforced plastic, which has a lower thermal conductivity than metal, is installed at the connection point between the base structure and the standing structure.
The fiber-reinforced plastic has a joint portion that is joined to the metal, a rubbing portion whose plate thickness gradually changes from the joint portion, and a general portion that is thinner than the joint portion and whose thickness does not change. Preparation
A low thermal conductivity anchor strap structure characterized by: further comprising a metal at the connecting portion between the base structure and the standing structure;
The bonding between the fiber-reinforced plastic and the metal is at least one of mechanical bonding using bolts and nuts, adhesive bonding, and bonding in which mechanical bonding and adhesive bonding are combined. The low thermal conductivity anchor strap structure according to claim 1. further comprising a metal at the connecting portion between the base structure and the standing structure;
2. The low thermal conductivity anchor strap structure according to claim 1, wherein the fiber-reinforced plastic and the metal are joined by hooking the fiber-reinforced plastic on the metal. The fiber-reinforced plastic has a portion in which the joint portion , the rubbed portion , and the general portion are connected in this order, and the thickness of the rubbed portion varies from the general portion side to the joint portion side. 4. A low thermal conductivity anchor strap structure according to claim 2 or 3, characterized in that the thickness increases toward the bottom . 5. The low thermal conductivity anchor strap structure according to claim 4, wherein the joint portion is provided with a through hole for a bolt to pass through. 6. The low thermal conductivity anchor strap structure according to claim 5, wherein the through hole has substantially the same diameter as the bolt. 5. The low thermal conductivity anchor strap structure according to claim 4, wherein the joint portion has a hook shape to be hooked on the metal. 8. The low thermal conductivity anchor strap structure according to claim 7, wherein the metal is provided with holes and/or protrusions for hooking the joint portion. The fiber orientation in the joint portion has a fiber direction equal to the axial direction of the low thermal conductivity anchor strap structure and an oblique lamination for preventing shear failure of the fiber reinforced plastic. Item 6. A low thermal conductivity anchor strap structure according to item 5. The low thermal conductivity anchor strap structure according to claim 9, wherein the angle of the oblique lamination with respect to the axial direction of the joint portion is approximately ±45°. 5. The low thermal conductivity anchor strap structure according to claim 4, wherein the fiber direction is substantially symmetrical with respect to the plate thickness center line of the fiber reinforced plastic. The low thermal conductivity anchor strap according to any one of claims 4 to 6 and 9 to 11, wherein the fiber reinforced plastic has a bundle structure in which two or more sheets are laminated in the plate thickness direction. structure. In the joint portion, a joint plate made of metal is sandwiched from both sides in a butted portion of the metal and the fiber-reinforced plastic, and each of the metal, the fiber-reinforced plastic, and the joint plate is bonded to the bolt/nut and/or bonded. 6. The low thermal conductivity anchor strap structure of claim 5, having an adhesive bonded structure. 14. The low thermal conductivity type anchor strap structure according to claim 13, wherein the nut is tightened with a predetermined torque in the joining means by the bolt and nut. The joint portion has a structure in which a joint plate made of fiber-reinforced plastic is sandwiched from both sides at the butted portion of the metal and the fiber-reinforced plastic, and each of them is joined with the bolt/nut and/or adhesive. The low thermal conductivity anchor strap structure according to claim 2.

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