JPS60245895A - Double even pipe structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Technical Classification/Field> The disclosed technology belongs to the technical field of vacuum insulated double piping structures for transporting rocket fuel and the like.

<Explanation of the gist> Accordingly, the present invention comprises a sealed outer tube having joint parts such as bayonet joints at both ends, at least one expansion joint interposed therebetween, and an inner tube. This invention relates to a double piping structure in which a unit's double piping is constructed by communicating internally, and in particular, a bellows is integrally interposed between a pair of short joint pipes, and a bellows is integrally inserted between a pair of short joint pipes. Three or more expansion joints are interposed in the outer tube, each of which is provided with hinge plates extending oppositely from the upper and lower parts of the flanges ringed at the opposing ends to pivot the bottle, and which are configured to be expandable and bendable in both directions. This invention relates to a double piping structure.

<Prior art> As is well known, liquid hydrogen is used as fuel for rockets used to launch artificial satellites, etc., and when transporting and supplying such liquid fuel to rockets, it is necessary to improve heat insulation, etc. Therefore, vacuum insulated double piping is used.

As shown in Fig. 1.2, this kind of vacuum insulated double piping has bent parts such as the U-shaped double piping 1a and the L-shaped double piping 1b, and has an outer pipe 2 and a bent part. It is composed of an inner tube 3 and is divided into units so that it can be easily transported to the destination.

Bayonet joints 4.4 as joints are connected to both ends of the double pipes 1a, 1b, and the inner pipe 3 is inserted into the outer pipe 2 from the bayonet joint 4 at one end, and the inner pipe 3 is inserted into the outer pipe 2 from the bayonet joint 4 at one end. A space 5 that communicates with and projects from the bayonet joint 4 and is formed by the outer tube 2 and the inner tube 3 is evacuated through a predetermined means to become a vacuum. A bellows 6 and the like are integrally formed so as to absorb the strain caused by the large expansion/contraction difference between the inner and outer tubes due to the temperature difference between the inner tube 3 and the outer tube 2.

<Problems with the prior art> However, the bellows 6 integrally formed on the outer tube 2 cannot sufficiently absorb the strain caused by thermal contraction of the inner and outer tubes of the double pipes 1a, 11 having bent portions. As a result, thermal deformation of the inner tube 3 is restrained by the outer tube 2, and a large bending stress is concentrated on the bayonet joint 4.4, which tends to damage the bayonet joint 4, etc., and causes liquid leakage. was there.

Furthermore, when one or two hinge plates are used, the movement of the inner tube is mechanically restricted, resulting in similar drawbacks.

Furthermore, when the space 5 formed by the outer tube 2 and the inner tube 3 is evacuated, a thrust force due to the vacuum is applied to the bayonet joint 4.4, causing a large bending stress to be generated in the bayonet joint 4.4. was there.

It is also possible to insert a spacer or the like to prevent contact between the inner and outer tubes due to heat contraction, but as mentioned above, the design must be strong enough to withstand the thrust caused by vacuuming, and the material of the spacer must be There were some problems in implementation.

<Object of the Invention> The object of the present invention is to solve the problems of the double piping structure having a bent part based on the above-mentioned prior art, and to A joint is inserted to minimize the restraining force of the outer pipe against the deformation of the inner pipe, reducing the concentrated stress applied to the end of the double pipe, and reliably preventing leakage of liquid fuel. It is an object of this invention to provide an excellent double piping structure that is beneficial to the field of piping application in industry.

<Structure of the Invention> In order to solve the above-mentioned problems, the structure of the present invention, which is in line with the above-mentioned object and whose gist is the scope of the above-mentioned claims, is that a bellows is integrally interposed between a pair of joint short pipes, and At least one expansion joint is connected to the outer pipe near the bent part of the double piping, and the expansion joint is pivoted by extending hinge plates to the flanges provided at opposite ends of the pair of joint short pipes. The restraining force of the outer pipe due to the deformation of the pipe is reduced by being dispersed and absorbed by the expansion and contraction behavior of the expansion joint, and the bending stress concentrated and applied to the end of the double piping due to the inner pipe restraint of the outer pipe is reduced. This technology takes technical measures to prevent damage to the end portion by suppressing the damage and to prevent leakage of liquid fuel.

<Embodiment - Configuration> Next, an embodiment of the present invention will be described below based on the drawings from FIG. 3 onwards.

Note that the same parts as in FIG. 1.2 will be explained using the same reference numerals.

In the embodiment shown in Fig. 3.4, 18' is a mouth-shaped vacuum insulated double piping, and lb' is a single-shaped vacuum insulated double piping, both of which constitute the piping of the unit. Three bellows joints 7 as expansion joints, which will be described later, are connected and interposed in the outer tube 2 including the outer tube 2 near the bent portion.

As shown in FIGS. 5 to 8, the bellows joint 7 constitutes a joint pipe by a pair of short joint pipes 8.8 and a bellows 6'. Both ends of a bellows 6' are fixed to the opposing inner surfaces of the pipe 8 through a predetermined means, and the bellows 6' is interposed protrudingly between the pair of short joint pipes 8.8.

A pair of flanges 9.10 are provided on the opposing outer surfaces of the pair of joint short pipes 8.8, and hinge plates 11 are provided on the upper and lower surfaces of one flange 9 and the other flange 10, respectively. .12 are arranged in two stacked upper and lower layers facing each other, and their base lower surfaces are fixed to the upper and lower surfaces of each flange 9.10 through means such as welding, and the hinges of each of the two stacked plates are The plate 11.12 is pivotally supported by a pin 14 through a washer 13, and a pair of joint short pipes 8.8 are bent freely in both directions around the pin 14, as shown in FIG. There is.

Incidentally, bayonet joints 4.4 are connected to both ends of the outer pipe 2 of each of the double pipes 1a', lb', as in the conventional embodiment, and the inner pipe 3 is inserted and communicated with the inner pipe 3 and the outer pipe. The space 5 of No. 2 is evacuated via a predetermined means.

<Embodiment - Effects> 1) In this configuration, the piping for transporting liquid hydrogen rocket fuel from the fuel supply source to the destination is a double pipe 18' shaped like a vacuum insulator, a double pipe L shaped vacuum heat insulated Piping 11)'
If a plurality of pipes for each unit are connected together, the function of transporting liquid hydrogen will be exhibited.

Therefore, a double pipe 1a having a bending part for each unit
Even if the inner tube 3 of ', 1b' is deformed due to the thermal load due to the temperature difference with the outer tube 2, or the load of wind, earthquake, etc., there is a bellows joint near the bent part of the outer tube 2. 1 are interposed and connected, so that the outer pipe 3 and the inner pipe 3
The restraining force is dispersed and absorbed by each of the bellows joints 7, and the outer pipe 2 mechanically follows the deformation of the inner pipe 3, so that the restraining force of the outer pipe 2 can be suppressed to a minimum. It looks like this.

In addition, the bending stress applied to the bayonet joints 4 and 4 at both ends of the double piping 1a' and 1b' is also reduced by each bellows joint 7, so that no excessive force is applied to the bayonet joints 4, etc. Damage can now be reliably prevented, and liquid fuel can be transported stably without leakage.

<Other Embodiments> It goes without saying that the embodiments of the present invention are not limited to the above-described embodiments, and various embodiments may be adopted, for example, the bellows may have a double structure to improve durability and pressure resistance. It is possible.

<Effects of the Invention> As described above, according to the present invention, the outer pipe sealed via the joints at both ends is provided with at least one expansion joint in the middle thereof, and the inner pipe is communicated with the inner pipe. In the piping structure, a bellows is integrally interposed between a pair of short joint pipes that form and cover the expansion joint, and a hinge plate is attached to a ring flange at the opposite end of the pair of short joint pipes. By having each tube extend oppositely and pivotably supported by a bottle, the strain caused by the temperature difference between the inner tube and the outer tube can be sufficiently absorbed by the expansion joint, and as a result, the restriction of the outer tube against thermal deformation of the inner tube is minimized. It is possible to reduce the bending stress that tends to concentrate at the end of the double pipe due to the bending part, and to have an excellent effect of reliably preventing damage to the end due to bending stress.

Therefore, the liquid fuel can be transported reliably by preventing liquid leakage, and the advantage is that the fuel can be safely supplied.

In addition, even if the space between the outer and inner tubes is evacuated, the joints at both ends of the double piping will not be affected in any way, so the installation of spacers, etc. that easily absorb external heat can be kept to a minimum. This has the added benefit of reducing heat absorption from the outside.

[Brief explanation of the drawing]

Fig. 1.2 is a partial cross-sectional explanatory diagram of a vacuum insulated double pipe based on the prior art, Fig. 3 and the following are detailed explanatory diagrams of the present invention, and Fig. 3.4 is a diagram equivalent to Fig. 1.2. , Figure 5 is a sectional view of the bellows joint, Figure 6 is a side view of the bellows joint, and Figure 7.8.
The figure is a plan view of a bellows joint. 4...Joint part, 2...Outer pipe, 7...Expansion joint, 3...Inner pipe, 1a', ib'...Double piping, 8...Joint short pipe, 6' ...Bellows, 9.10...Flange,

Claims (1)

[Claims] In a double piping structure in which an outer pipe sealed via both end joints is provided with at least one expansion joint in the middle thereof, and an inner pipe is communicated with the inner pipe, the above-mentioned expansion joint is A pair of joint short pipes is integrally interposed between the pair of joint short pipes, and hinge plates are respectively extended oppositely from flanges provided at opposite ends of the pair of joint short pipes. A double piping structure characterized by having three or more pivotally supported structures interposed in the outer pipe.