JPH0318792Y2 - - Google Patents

Description

[Detailed description of the invention] [Field to which the invention pertains] The present invention relates to a vibration isolator, and is particularly intended to allow low-speed displacement of objects to be vibration-isolated, such as piping, and to prevent high-speed displacement due to earthquakes, etc. This invention relates to a vibration isolator.

[Prior art and its problems]

Regarding various types of piping under special environments such as thermal power plants and nuclear power plants, there are various restrictions in terms of anti-vibration measures. That is, in locations where the temperature changes significantly throughout the day or throughout the year, it is necessary to effectively tolerate slow movement of the piping. On the other hand, it is necessary to effectively prevent sudden vibrations caused by earthquakes and the like to prevent piping damage accidents.

Research on vibration isolation means that can effectively overcome this type of restriction has been carried out in various directions. For example, there is a system in which the linear reciprocating motion of vibration is converted into rotational motion, and a generator is installed in the rotating part to perform dynamic braking.

However, conventional systems using dynamic braking have a complicated and expensive structure, use many coils and require load resistance, and therefore have complicated equipment.
In addition, productivity is low, and since a large amount of current flows through the resistance circuit of the load during operation, the electrical components deteriorate over time, resulting in poor durability. Further, there was a problem in that it was difficult to deal with areas where thermal deformation was large.

[Purpose of invention]

The present invention improves the disadvantages of such conventional examples, and in particular, has a simple structure, does not require any electrical parts, is durable, and has stable operation that can sufficiently cope with areas subject to large thermal deformation. Its purpose is to provide a vibration isolator.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 1 indicates a cylindrical first support container, and reference numeral 2 indicates a load column as a cylindrical second support container. The second support container 2 is loosely inserted into an opening 1A formed at one end of the first support container 1 and engaged with the first support container 1. In addition, the first support container 1
is formed into a stepped tubular shape with an overall T-shape,
A lid 1B is provided with a mounting portion 1a at its upper end. A housing portion 1C is provided in the center portion of the first support container 1. A screw shaft 3 is disposed on the central axis of the first support container 1 . The screw shaft 3 is rotatably supported at its intermediate portion by the thrust bearing 6 in the housing portion 1C described above. The screw shaft 3 has a ball screw portion 3A necessary as a ball screw mechanism formed at one end thereof. A ball nut 4 for a ball screw mechanism is screwed into this ball screw portion 3A.

This ball nut 4 is firmly supported by the load column 2, which serves as the second support container described above.

A keyway is formed on the side surface of the ball nut 4,
A sliding key 5 that guides this keyway is fixed to the inner wall of the first support container 1. Due to the guiding action of the sliding key 5, the ball nut 4 is biased by the rotational movement of the ball screw portion 3A, so that it can reciprocate extremely smoothly.

A disk-shaped flywheel 7 is provided at the upper end portion of the screw shaft 3 in FIG. In this case, the flywheel 7 effectively acts on the ball screw mechanism as follows. That is, the ball screw mechanism is a mechanical element that converts linear motion into rotational motion. When this ball screw mechanism is installed between the piping and the floor, it exhibits almost no resistance to gradual movement due to thermal expansion of the piping, but due to earthquakes etc. If a sudden relative movement is about to occur between them, the relative movement is considerably suppressed except at the resonance point by the rotational inertia effect of the screw shaft 3 (therefore, the deformation of the piping is reduced). This relative movement suppression effect increases as the moment of inertia of the screw shaft 3 increases, so if a flywheel 7 of an appropriate size is added to the tip of the screw shaft 3, the relative displacement between the pipe and the floor can be more effectively suppressed. You will be detained. In addition, since this flywheel is shaped like a disk, if the installation length (height) of the device is constant, the screw shaft 3 can be set relatively long, which results in a relatively large amount of heat. Even deformed areas can be adequately accommodated. The code 8 is
A rubber or plastic bellows is shown mounted on the outside of the lower part of the first support container 1 as a dust guard.

Therefore, since the vibration direction of seismic waves repeats in the forward and reverse directions in a short period of time, by equipping the flywheel 7 as described above, the purpose of vibration suppression described above can be fully achieved. It's summery.

The upper part of the flywheel 7 is equipped with a dynamic braking means 10 as shown in FIG. This dynamic braking means 10 includes a rotating disk 1 made of a non-magnetic material.
1, and a pair of upper and lower permanent magnets 12A and 12B that are disposed at the end of the rotating disk 11 and have a magnetic path in a direction perpendicular to the rotating surface of the rotating disk 11. The rotating disk 11 is made of copper or aluminum. Further, each of the plurality of sets of permanent magnets 12A and 12B is attached with the north pole 12A and the south pole 12B facing each other with the rotating disk 11 in between. Reference numeral 13 indicates a partition plate provided between the flywheel 7 and the rotating disk 11.

In this case, the rotating disk 1 is damaged due to an earthquake or the like.
1 rotates, the rotating disk 11 cuts the magnetic flux between the N pole 12A and the S pole 12B of the permanent magnet, causing an eddy current in the rotating disk 11, and this eddy current and the magnetic flux of the permanent magnet 12 Due to the interaction with the rotating disk 11, a force in the opposite rotation direction is exerted on the rotating disk 11. This braking torque has a magnitude proportional to the rotational speed.

In this case, in addition to using a strong magnet such as a rare earth magnet to strengthen the magnetic field between the N and S poles,
It is preferable to use iron material for each of the first support container 1 and the partition plate 13 to form a magnetic path.

Therefore, even if the piping system is shaken by resonance frequency due to an earthquake or the like, and the relative displacement and velocity between the piping and the floor become large (therefore, the rotational speed of the ball screw shaft 3 will increase) ), the rotation of the screw shaft 3 is braked by the braking torque generated based on the eddy current generated in the rotating disk 11, and the deformation of the piping is restrained. Further, as described above, when the piping is shaken at a frequency other than the resonance frequency, the deformation of the piping is restrained by the rotational inertia effect of the screw shaft 3 and flywheel 7.

[Effect of idea]

Since the present invention is configured and functions as described above,
According to this, since a flywheel is used, normal vibrations can be effectively suppressed by its inertia force and deformation of piping etc. can be restrained, and the flywheel is shaped like a disk. Therefore, it is possible to increase the inertia force by several steps compared to a cylindrical object of the same weight, and the thickness direction of the flywheel can be set smaller, so the dimensions of the device attachment point remain constant. In this case, the screw shaft portion can be set relatively long, and therefore, it is possible to sufficiently cope with relatively large thermal deformation locations. In addition, with respect to resonant vibrations in piping, etc., it is possible to effectively suppress the resonant vibrations that occur suddenly due to the interaction between the rotating disk and the permanent magnet, and also effectively restrain and protect the deformation of the piping, etc. In addition, since the structure does not use any electrical parts such as resistors or coils as a dynamic braking means, the durability can be significantly increased, and the simplified structure improves productivity and maintainability. It is possible to provide a vibration isolating device that is fully equipped with unprecedented practicality in that it can improve the performance of the vibration damping device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1... First support container, 1A... Opening, 2...
...Load column as a second support container, 3...
Screw shaft, 7... flywheel, 10... dynamic braking means, 11... rotating disk, 12A, 12B... permanent magnet.

Claims (1)

[Claims for Utility Model Registration] A cylindrical first support container, a second support container loosely inserted through an opening of the first support container and engaged with the first support container; A screw shaft disposed on the central axis of the first support container and rotatably supported by the first support container, and a screw shaft screwed into a threaded portion formed at one end of the screw shaft and the second A vibration isolator having a nut portion fixed to a support container and having a dynamic braking means at the other end of the screw shaft, wherein the dynamic braking means is a rotating disk made of an electrically conductive and non-magnetic member. and a permanent magnet that is disposed at the end of this rotating disk and has a magnetic path in a direction perpendicular to the rotating surface of the rotating disk, and the lid, partition plate, and housing part are connected to each other through this permanent magnet. A vibration isolating device characterized in that a closed magnetic path is formed by a part of the screw shaft, and a disc-shaped flywheel is attached to the other end of the screw shaft in addition to the dynamic braking means.