JPS6011276B2 - Piping support device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe support device, and in particular to a pipe support device suitable for supporting pipes for liquid metal cooled fast breeder reactors, which undergo weight changes due to filling and discharging of fluid inside the pipes during high-temperature operation. The present invention relates to a support device.

A conventional constant load type pipe support device is characterized in that it can always support the pipe with a constant load even when there is vertical heat movement in the supported pipe. FIG. 1 is an example of a longitudinal sectional view of a conventional constant load type pipe support device. In FIG. 1, the end of a coil spring 3, which is housed in a spring case 2 and has one end fixed to the end of the spring case 2, is connected to a rotating arm 7 by a pin B via a rod 5 fixed to a spring plate 4. . The rod 5 has an elongated hole 6, and a pin C fixed to the spring case 2, which is iron-fitted to the innermost hole 6, serves as the rotation axis of the rod 5 as well as a guide pin. The weight of the pipe is supported via the rod 8. For example, when the supported piping moves downward due to thermal expansion, the pin A moves downward, the rotating arm 7 rotates clockwise about the main shaft P, and the spring plate 4 coupled to the rod 5 compresses the coil spring 03. Although the reaction force of the coil spring increases, the load supported by the rod 8 does not change. This operating principle is well known and can be explained as follows with reference to FIG. That is, in Fig. 2, from point P to straight line BC
The length of the perpendicular x drawn to is expressed as follows from the well-known formula of trigonometric functions. X = sheep i small….・{210
Here, b; constant with the length of the straight line BP; constant with the length of the straight line CP; 1; length of the straight line BC; J; the angle formed by the straight line BP and the straight line CP; and the balance condition of the moment around point P. The following relational expression is obtained.

Wasino=k6x: k6 is also small... ．．・'3} Here, 8; angle k between straight line AP and vertical line; spring constant of coil spring 6; amount of deflection W of coil spring; support load a; length of straight line AP; If the condition that 6 and 1 are always equal is satisfied, the supporting load W will always be equal regardless of the position of point A, as shown in Z next.

Wkik-----■ The 8th stop is the opening angle Q of the rotating arm equal to (Ge-B) when the constant angle between the straight line PC and the horizontal class is 8, so it is also 6 and 1 make the initial deflection of the coil spring equal to the length of straight line BC when there is no external force, so
are always equal.

Since the conventional constant load type pipe support device operates as described above, it is suitable for supporting pipes of constant weight that are operated at high temperatures.

However, for example, in a fast breeder reactor that uses liquid sodium as a coolant, the piping that contains the coolant must be heated to a certain temperature (for example, 200°C), but it is difficult to install the piping. It is extremely difficult to maintain the piping at such a high temperature during the installation stage of the support device. Therefore, it is necessary that the above-mentioned operation be carried out at room temperature without the inclusion of a coolant. On the other hand, the load W of the pipe support device is determined for the pipe containing the coolant,
Therefore, while the pipe to which the support device is attached as described above is not filled with coolant, in addition to the support load W8 that balances the weight of the pipe, the force FN corresponding to the weight of the coolant is applied to the pipe support device. You will receive it from That is, FN
=W-WB...[1] This force FN causes extra stress on the pipe, especially in large-diameter main pipes where this force FN reaches about 50% of the supporting load W during operation. However, each time the coolant is filled and discharged, a large stress is applied, which poses a major problem in terms of fatigue strength.

Furthermore, the pipes should be kept at a certain temperature (e.g. 20°C) before filling the coolant.
When preheating to 0qo) and checking for interference with structures or other piping, there is a risk of erroneous judgment because the deformation behavior due to the force FN is also exhibited in addition to the deformation behavior due to pure thermal expansion. SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a pipe support device that can automatically generate a support load that responds quickly to stepwise changes in pipe weight.
The piping support device of the present invention comprises: [a] a container; [b] a plurality of coil springs having different lengths and diameters, arranged in the same circular shape within the container, each having one end fixed to the container;
The main component is a constant load transmission mechanism in which one end of the coil spring is attached to the end of the longest spring of the coil springs on the side opposite to the container fixing side, and the pond end is attached to the piping via a link mechanism, and Each coil end on the opposite side to the fixed side is engaged in parallel in sequence from the longest coil spring end to the shortest coil end so that the supporting load of the spring increases in stages as the displacement of the piping increases. It is characterized by being configured to fit.

An embodiment of the invention is shown in FIG.

In FIG. 3, the other end of the coil spring 3A is housed in the spring case 2 and has one end fixed to the end of the spring case 2.
pin B via the rod 5 fixed to the spring plate 4A.
is connected to the rotating arm.

The rod 5 has an innermost hole 6, which is fitted over the outermost hole 61. A pin C fixed to the spring case 2 serves as a guide pin and a rotating shaft for the rod 5. Also provided within the spring case 2 is another coil spring 3B whose one end is compressed by a fixed piece 9 of the spring case 2 via a spring plate 4B. The spring plates 4A and 4B are spaced apart from each other by 6s. 6s, the amount of heat transfer in the downward direction of the supported piping corresponding to the piping temperature in which the supporting load is changed stepwise, that is, the cooling material filling and discharging temperatures, is applied to the pin A portion via the rod 8. This value is equal to the amount of increase in the distance between pin B and bin C when

Further, the coil spring 3A is given an initial compression deflection equal to the distance between B and C when there is no external force, and the coil spring 3B is given an initial compression deflection that is larger by 6 seconds. Therefore, by using the same concept as the above-mentioned formulas [3- and {4], formulas Waki-'8} are derived. That is,
If the movement amount of the spring plate 4A is 6 seconds or less, WEa
Sin○:k. 6. ¥Si small. ．． ．． ．． ．． (5) WE=k... ■Here, k,; Spring constant 6 of coil spring 3A
1; Total amount of deflection of coil spring 3A Also, if the amount of movement of spring plate 4A exceeds 6 seconds, spring plate 4A contacts spring plate 4B and both springs begin to be compressed at the same time, so Wasin8=(
k・6・10k262) School culture. ．． ．． ．． ．． ．． [71W = Good (
k. 10k2)-...-{8) Here, K2; Spring constant of coil spring 3B 62: Total deflection amount of coil spring 3B In the formula and the shelf type, each value of a, b, and c is determined by the support device as described above. is a constant dimension specific to , and the spring constant k
,, k2 is a constant spring constant, so the spring plate 4
The pipe support device can exert two types of constant loads, WB and W, before and after the movement amount A of 6 seconds.

This characteristic is as shown in FIG. According to this embodiment, when the piping is not filled with high-temperature fluid, the piping is supported by a load WE that balances the weight of the piping, and after the piping is filled with high-temperature fluid, the piping containing the fluid is moved as the piping undergoes thermal displacement. Since the piping is automatically supported with a load W that is in balance with its weight, the same piping support device can prevent stress changes and positional displacements caused by changes in the load applied to the piping before and after high-temperature fluid flow. It has the advantage of being able to significantly suppress the heat and to prevent deformation caused by applying excessive force to the piping before the high temperature fluid flows therethrough.

FIG. 5 shows another embodiment of the present invention, which has the same structure as the embodiment shown in FIG. 3, but includes three coil springs.

In this embodiment, a coil spring 3E (with one end fixed to the end of the spring case 2) is attached to the outside of the coil spring 3B.
The length of coil spring 3E is shorter than coil spring 3B,
) are provided concentrically and attached to the spring case 2.
The other end of the coil spring 38 is supported by a spring plate 48 supported by '. Spring plates 2B and 4E are separated by an interval of 6s'. In such a configuration, when the rod 5 moves by only 6 seconds, the behavior is similar to that shown in FIG. 3, and when the rod 5 moves by a further 6 seconds, the coil springs 3A, 3B, and 38 behave as parallel springs. This principle is exactly the same as that shown in Figures 3 and 4,
This allows three different support loads to be automatically obtained. As a result, even if, for example, the fluid in the piping is replaced with a fluid with a different specific gravity during operation, which increases the load applied to the piping and causes the position of the piping to shift, this can be done in two or three stages. Since the support loads of the stage and the support device automatically increase, the effect is that the amount of displacement can be sufficiently suppressed. In the two embodiments of the present invention described above, the heat transfer of the supported piping is downward, but even when the heat transfer of the supported piping is upward, the same effect can be achieved by changing the position of the coil spring that operates from the middle. Effects can be obtained.

As described above, according to the present invention, it is possible to provide a pipe support device that can automatically exert a supporting load that immediately responds to gradual changes in the weight of supported pipes, so that the displacement that occurs in the pipes due to weight changes can be provided. It is possible to significantly suppress it.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a constant load type pipe support device using the follower technology, Fig. 2 is an explanatory diagram of the operating principle of the pipe support device of Fig. 1, and Fig. 3 is a preferred embodiment of the present invention. FIG. 4 is a longitudinal sectional view of a certain two-stage constant load type pipe support device, FIG. 4 is a characteristic diagram of the pipe support device of FIG. 3, and FIG. FIG. 3A, 3B, 3E...Coil spring, 4A, 4B, 4C,
4E... Spring plate, 9... Piece, 5...
Rod, 7... Rotating arm, A, B, C... Pin, P""" Main shaft.

Claims (1)

[Claims] 1: (a) a container; (b) a plurality of coil springs of different lengths and diameters arranged concentrically within the container and each having one end fixed to the container; (c) one end of the coil spring; The main component is a constant load transmission mechanism, which is attached to the end of the longest spring opposite to the container fixing side, and the other end is attached to the piping via a link mechanism, and the other end is attached to the opposite end of the container fixing side. Each coil end is configured to engage in parallel in sequence from the longest coil end to the shortest coil end so that the supporting load of the spring increases stepwise in response to an increase in piping displacement. A piping support device characterized by: