JPS60220280A - Snack bar - 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 [Field of Application of the Invention] The present invention relates to a mechanical snap bar for supporting piping, which is suitable for use when supporting various piping installed in, for example, nuclear power plant equipment. - related to

[Background of the invention]

In nuclear power plant equipment, a huge number of various types of piping are installed, and the number of locations for piping support structures that support these pipes is approximately 25,000 in each nuclear power plant equipment. In addition, there are many different types of piping support structures, such as those that suppress sudden shock vibrations such as those caused by earthquakes, those that support the weight of piping and its attached equipment, and those that limit excessive displacement due to thermal expansion of piping. There are types that suppress fluid vibrations in piping and mechanical vibrations generated from pumps and other rotating equipment, and even types that have a combination of the above functions. Depending on the purpose and conditions of use, the various piping support structures listed above , K is designed to be installed in the same direction as the piping axis, in a direction perpendicular to the piping axis, and in a direction inclined to the piping axis.

Figure 1 is a schematic illustration of a conventional oil snubber.
In the figure, a indicates a cylinder, b indicates an oil reservoir, and other specific structures and functions are well known.

When using this oil snubber to support various types of piping, unless the piping is installed in a special environment, there will be no particular problem in using the snubber itself.
When piping is installed in nuclear power plant equipment, there is a problem in that hydraulic oil is exposed to a large amount of radiation and its properties change, making it unable to function as a snubber.

For this reason, oil snubbers that support piping installed in high radiation areas, such as reactor secondary cooling system piping, have traditionally had their hydraulic oil replaced periodically; In order to regularly replace the hydraulic fluid of the machine, not only is the replacement work itself troublesome, but
The utmost care must be taken to prevent workers from being exposed to radiation.

Nuclear power plant equipment has an extremely large number of supporting parts for piping, depending on the purpose of use and conditions.
The piping support snubber is installed in the same direction as the piping axis, perpendicular to the piping axis, or diagonally to the piping axis, but when using an oil snubber to support the piping, use any of the above mounting methods. Even if such a system is adopted, the oil reservoir shown in FIG. 1 must be set vertically in order to prevent oil leakage.

Fig. 2 is a partial vertical sectional view showing the internal structure of a conventional mechanical snap bar. In the figure, C is a pole screw, d is a flywheel that converts the linear motion of the pole screw C into rotational motion, and
1 shows a flywheel bearing, and the other specific construction and operation are also well known as in the case of the oil snubber shown in FIG.

When using this mechanical snubber to support various types of piping, unless the piping is installed in a special environment, there will be no particular problem in using the snubber itself, as in the case of an oil snubber. When piping is installed in nuclear power plant equipment, the lubricating oil applied to rotating sliding parts such as pole screws C and flywheel bearings e is exposed to radiation and its properties change, albeit in small amounts. As with the case of oil snubbers, it is essential to manage the maintenance of the snapper until it is no longer able to fully fulfill its function as a snapper.

[Purpose of the invention]

The present invention was made as a result of various research and development in order to solve the problems of the conventional oil snubber and mechanical snubber described above. A mechanical snubber with an unprecedented new structure that is maintenance-free and has a spring constant that can be changed depending on the location of the piping, offering excellent reliability and versatility as a shock absorber.
This is what we are trying to provide.

[A essential point of the invention]

In order to achieve the above object, the snubber according to the present invention includes:
A cylinder and a rod each having a joint attached to one end thereof are provided, and the rod is accommodated in the cylinder, and
A spring constant adjustment piece having a spiral groove for fitting a helical spring is attached to the outer periphery of the rod housed in the cylinder.
It is characterized in that a helical spring is fitted into the spring fitting spiral groove of the bridge.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on an embodiment shown in FIGS. 3 to 5. FIG. 3 shows a diagram of the piping support structure by the snubber of the present invention, and FIG. 4 shows the internal structure of the snubber of the present invention. The vertical sectional view and FIG. 5 are perspective views of a spring constant adjusting piece which is a main component of the snubber of the present invention. In FIG. .

In FIG. 4 showing the internal structure of the snubber of the present invention, the snubber 1 is roughly divided into a cylinder 2 and a rod 3, each having a universal joint 4 and 5 attached to one end thereof, and a rod 3 having a universal joint 5 attached to one end thereof. A flange 6 serving as a so-called stop seat is provided at the other end of the flange 3 for receiving a helical spring 9, which will be described later. However, the above rod 3
is housed in the cylinder 2, and the outer periphery of the nine rods 3 housed in the cylinder 2 has a spring constant adjusting groove 8 for fitting a helical spring, as shown in FIG. A working piece 7 is attached, and a helical spring 9 is fitted into a spring fitting spiral groove 8 of the piece 7. Fourth
In the figure and FIG. 5, 10°10 is a cross-shaped hole drilled from the outer periphery of the piece 7 toward its axis. A bar tool (not shown) is inserted.

The present invention has the above configuration, and the snubber of the present invention
For example, the state in which the piping is specifically supported by the snubber 1 is as shown in FIG. If you insert the bar-shaped tool into the hole 10 of the piece 7 and rotate the piece 7 by operating this bar-shaped tool, the piece 7
moves in the direction of arrow F1 or F2 in FIG. 4 along the helical spring 9 fitted in the helical groove 8 of the piece 7, just as the male thread moves forward and backward with respect to the female thread, Since the position of the piece 7 is changed, the helical springs 9a and 9 located on the left and right sides of the piece 7 are placed in the center.
The spring constant of b can be adjusted as appropriate.

Specific examples of changing the spring constant of the snubber depending on the piping installation location include, for example, when the snubber is used to suppress sudden shock vibrations such as those caused by an earthquake, or when excessive vibrations due to thermal expansion of the piping occur. Examples include cases where snubbers are used to limit large displacements, and furthermore, where snubbers are used to suppress fluid vibrations in piping or mechanical vibrations generated from pumps or other rotating equipment. It will be done.

〔Effect of the invention〕

As detailed above, according to the present invention, the shock absorber has reliability and versatility as it is maintenance-free despite its simple configuration and can change the spring constant depending on the location where the piping is installed. It is possible to provide a mechanical snubber with an unprecedented new structure with excellent performance.
In particular, unlike conventional oil snubbers or mechanical snubbers, the snubber of the present invention does not use hydraulic oil or lubricating oil whose properties change due to radiation irradiation. The effect when adopted in nuclear power plant equipment is extremely significant.

[Brief explanation of the drawing]

Fig. 1 is a schematic structural explanatory diagram of a conventional oil snubber, Fig. 2 is a partial vertical sectional view showing the internal structure of a conventional mechanical snubber, and Figs. 3 to 5 show an embodiment of the present invention. 3 is a diagram of the piping support structure by the snapper of the present invention, Figure 4 is a vertical sectional view showing the internal structure of the snapper of the present invention, and Figure 5 is a diagram showing the spring constant adjustment which is the main component of the snapper of the present invention. It is a perspective view of a working arm. DESCRIPTION OF SYMBOLS 1...Snat bar-12...Cylinder, 3...Rod, 4 and 5...Universal joint, 6...Flange,
7... Arm for adjusting spring constant, 8... Spiral groove for fitting helical spring, 9... Spiral spring, 10... Hole, 11...
··Piping. Agent Patent attorney Hiroo Nagasaki (1 other person)

Claims (1)

[Claims] 1. A spring constant adjustment device comprising a cylinder and a rond each having a joint attached to one end thereof, the rond being housed in the cylinder, and having a helical groove for fitting a helical spring on the outer periphery of the rond housed in the cylinder. Snut bar-0, characterized in that a helical spring is fitted into a spiral groove for fitting a spring in the piece.