JPS6411849B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention allows slow displacement of equipment such as piping systems in power plants, chemical plants, etc. due to temperature changes, but does not allow rapid displacement due to earthquakes etc. The present invention relates to a vibration isolator that has the function of restraining vibrations.

Piping systems in power plants and chemical plants expand and contract as the temperature changes due to the fluid being transferred, causing slow displacement. Therefore, it is necessary to allow such slow displacement so as not to apply undue stress to the pipe system. On the other hand, sudden vibrations in the pipe system due to earthquakes and the like must naturally be prevented. As a vibration isolator for such equipment, the relative reciprocating motion in the axial direction between one support member connected to the pipe system and the other support member connected to the structure is controlled by a weight using a ball screw mechanism. There is a known type that converts the rotational motion into rotational motion and restrains sudden displacement of the pipe system by inertial resistance against the rotational motion. However, in this type of ball screw, since an external load acts directly on the ball screw, it is large in size and must be of high quality, making it expensive. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vibration isolator that is robust and inexpensive compared to conventional vibration isolators.

An example will be described below with reference to the drawings. One end of the square cylindrical casing 1, which is one support member, can be connected to the structure via a handle 1a, and from the other end, one end of the square column-shaped connecting rod 2, which is the other support member, is connected to the structure. , are inserted freely relative to each other in the axial direction. The other end of the connecting rod 2 is connected to a vibration-isolated object such as a piping system via a handle 2a. Therefore, when a relative movement occurs between the object to be vibration-isolated and the structure, the connecting rod 2 moves in and out of the casing 1 in the axial direction.

A ball screw 3 is rotatably supported between both end walls 1b and 1c of the casing 1 in parallel with the connecting rod 2. One end of the ball screw passes through the casing end wall 1c and has a rotating weight W outside the casing. Since this rotating weight W is held by disc springs S from both sides, it can rotate idly without exerting excessive torsional force on the ball screw 3. The ball screw 3 is screwed into a pair of opposing ball nuts 4, 4 at its intermediate portion, and freely passes through a pair of opposing friction plates 5, 5 disposed between both ball nuts.

Each ball nut 4 prevents its rotation, but
It has a rectangular mounting plate 4a that fits inside the casing 1 so that it can move freely in the axial direction. Abutting pieces 4b are provided protruding from the opposing inner sides of each mounting plate 4a.

Both friction plates 5 have a rectangular plate shape and cannot be rotated, but are inserted into the casing 1 so as to be freely movable in the axial direction. They are connected by a shaped leaf spring 5a. The side edges of both friction plates 5 on the sloped top side face the inner surface of the casing 1, and the other side edges engage with both edges of the engagement recess 2b provided on one inner side of the connecting rod 2. Further, both outer surfaces thereof are in contact with the tips of the contact pieces 4b of the ball nut mounting plate. The ball screw 3 loosely passes through a through hole 5b formed in both friction plates 5 and having a larger diameter than the outer diameter of the through hole 5b.

Next, the operation of this device will be explained. When the pipe system expands and contracts due to temperature changes and is displaced relative to the structure, the connecting rod 2 gently moves in and out of the casing 1, and the friction plate 5 moves left and right along with this. Ball nut 4 is pushed by this, and weight W
At the same time, the ball screw 3 is slowly rotated and driven. In this way, slow relative displacement between the structure and the piping system is easily tolerated.

On the other hand, when a sudden relative displacement occurs between the structure and the piping system due to an earthquake or the like, the connecting rod 2 tries to move in and out of the casing 1 suddenly, but the inertia of the weight W This restricts the rotation of the ball screw 3, and the movement of the ball nut 4 lags behind the movement of the connecting rod 2 in and out. Then, the connecting rod 2 touches the contact piece 4b of one of the ball nut mounting plates.
The friction plate 5 is compressed against its spring 5a. The friction plates 5 stand up while reducing their mutual inclination angles, press their side edges against the inner surface of the casing 1, and prevent the connecting rod 2 from moving in and out of the casing 1 due to the frictional resistance. That is, here, the ball screw 3 equipped with the weight W and the ball nut 4 screwed therewith sense a constant acceleration of the relative movement between the casing 1 and the connecting rod 2, and apply a braking action to the friction plate 5. It acts as a vibration sensitive means to cause the vibration to occur. While the piping system vibrates repeatedly, even if there is a resonance state with the vibration based on the internal torsional spring properties of the weight and the ball screw, the weight W in the present invention idles between the disc spring S and the ball screw 3 Do not apply excessive torque. After the rapid movement in and out between the casing 1 and the connecting rod 2 is completed, the weight W starts rotating together with the ball screw 3, and the ball nut 4 moves accordingly, allowing the friction plate 5 to tilt. As a result, the friction plate 5 is restored to its original state, its inclination angle increases, and the friction between it and the inner surface of the casing 1 decreases, allowing relative movement between the casing and the connecting rod.

4 to 6 show another embodiment using one ball nut 4. In this case, the tip of one abutment piece 4b is made to face the outer surface of one friction plate 5 as in the previous embodiment, and the other abutment piece 4c connects the friction plate 5 from the mounting plate 4a. The connecting rod 4d extends freely through the connecting rod 4d, and its inner surface faces the outer surface of the other friction plate 5. In this embodiment, one of the two ball nuts 4 that operate in exactly the same manner as in the previous embodiment is omitted, and one
In this embodiment, one ball nut 4 is replaced with another ball nut by extending its arm beyond the friction plate 5 to hold the friction plate 5 from both sides, and functions in exactly the same way as the previous embodiment.

Still other embodiments are shown in FIGS. 7 and 8. In this embodiment, a weight is used as a vibration sensing means for sensing vibration and causing a brake operation.
In place of the ball screw and ball nut mechanism, a wire 6 and a weight W around which the wire 6 is wound and rotated are used.
The casing 1, the connecting rod 2 and the friction plate 5 are assembled in the same way as in the previous two embodiments. Casing 1
A pair of pulleys 7 are pivoted on both sides of the pulley 7, and a weight W is rotatably pivoted on a vertical shaft 8 outside the center thereof. A wire 6 is wound between both pulleys 7, 7, and this wire 6 is wound around a vertical shaft 8 in the middle, and is locked to a friction plate 5 at each end.

Thus, when the connecting rod 2 slowly moves in and out of the casing 1, the friction plate 5 moves together with the wire 6 while slowly rotating the weight W. However, when it moves in and out suddenly, the movement of the wire 6 and the friction plate 5 connected thereto is delayed by the relative movement of the casing 1 and the connecting rod 2 due to the inertial resistance of the weight W, and the friction plate 5 2, the springs 5a are compressed to stand up against each other, and their upper edges are pressed against the inner surface of the casing 1 to produce a braking action. In addition, as an application of this, it is possible to have a structure in which the weight W is directly attached to the pulley 7. Furthermore, the vibration sensing means in the present invention is capable of sensing the vibration between the structure and the object to be vibration-proofed, that is, between both supporting members such as the casing 1 and the connecting rod 2, and can be displaced with a delay in the relative displacement between the two. Any known vibration isolator such as a hydraulic vibration isolator or a spring type vibration isolator can be used as the vibration sensing means in the present invention. In other words, by incorporating various conventionally known vibration isolators into the configuration of the present invention, the vibration isolation function can be increased several times.

Since the present invention is configured as described above, it is possible to provide a vibration isolator that has a relatively simple structure, does not require much mechanical precision, can be obtained at low cost, and is robust.

[Brief explanation of drawings]

Fig. 1 is a sectional view, Fig. 2 is a sectional view of Fig. 1, Fig. 3 is a sectional view of Fig. 1, Fig. 4 is a front view of main parts of another embodiment, and Fig. 5 is the same plane. Figure, 6th
The figures are FIG. 5 - sectional view, FIG. 7 is a sectional view showing still another embodiment, and FIG. 8 is FIG. 7 - sectional view. 1... Casing, 2... Connecting rod, 3... Ball screw, 4... Ball nut, 4a... Mounting plate,
4b, 4c...Abutting piece, 4d...Connecting rod, 5...
Friction plate, 5a...plate spring, 5b...through hole, 6...
...Wire, 7...Pulley, 8...Vertical axis, W...
Weight, S... disc spring.

Claims (1)

[Scope of Claims] 1. A pair of supporting members, each connected to a structure or a vibration-isolating object, and assembled together so as to be able to freely move back and forth relative to each other in the axial direction, which are inclined in opposite directions and mutually maintain this inclined state When both outer sides of the expansion side are respectively engaged with at least a pair of engaging parts of the one support member and the angle formed between them is reduced, the convergence side end becomes at least one pair of friction plates that can be frictionally engaged with a corresponding friction surface of the other support member; and a friction plate that is displaced to follow a slow relative displacement in the axial direction between the two support members, but is displaced to follow a sudden displacement. vibration-sensing means that is displaced with a delay relative to the friction plate, and, due to this delay, cooperates with one of the engaging portions of the one support member to reduce the angle formed between the friction plates.