JPS60116938A - Vibration suppressor - Google Patents

Abstract

PURPOSE:To improve the reliability and safety, in a vibration suppressor provided with a mechanical vibration-isolating mechanism comprised of a ball screw ball nut, by enabling quick suppression of micro displacement. CONSTITUTION:A load column 3 is fitted slidably with a sliding frictional cylinder 19 where a sliding cylinder 17 is lined with frictional member 18 and a pair of elongated holes 20 are made axially in a portion of said cylinder 19. Each stopper bolt 21 is fixed horizontally through each belleville spring 22 and each elongated hole 20 to the load column 3 where both elongated holes 20 are located. An idle cylinder 23 having a flange section 23a is fitted to the load column 3 below said cylinder 19 and engaged resiliently with a holding cylinder 9 through coil springs 24, 26. Consequently, the spring constant is high for micro vibration resulting in vibration suppressing function.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an allocator interposed between a supported body and a supporting body (stationary member) by four types of equipment, piping, etc. in a nuclear power plant, for example. Regarding device σ.

In particular, the present invention relates to a vibration damping device that allows expansion and contraction due to thermal expansion and damps vibrations and shocks caused by earthquakes and the like.

[Technical background of the invention]

In general, supported bodies such as piping in Zorant nuclear power plants, chemical plants, etc. can tolerate gradual changes due to thermal expansion due to temperature changes, but are particularly susceptible to high acceleration displacement due to sudden external forces such as earthquakes.

It is designed to suppress vibration.

As vibration damping devices of this type that have already been proposed, (1) a hydraulic vibration isolator and (c) a mechanical vibration damping device using a ball screw have been proposed.

That is, this mechanical vibration isolator is constructed as shown in FIG.

In FIG. 1, the reference numeral 1 denotes a connecting member connected to a supported body such as a pipe by a support shaft, and one end portion /a of this connecting member 1 is connected to a cylindrical load column 3.
A dust cover cylindrical body DA is concentrically hung vertically by a set screw S, and a pole nut 6 is attached to the lower end 3a of the load column 3. A ball screw 13, which will be described later, is screwed into this pole nut base.

On the other hand, a support member 7 connected to a stationary member is erected directly below the load column 3, and a holding cylinder 9 having a built-in mechanical vibration isolating mechanism g is mounted on the support member 7 to support the load column 3. 3 so as to be able to slide relatively thereon. Further, this holding cylinder is formed of a cylindrical part 9a and a bulging cylinder part 9b), and a sliding key IO is attached in the axial direction on the inner periphery of this cylindrical part 9a. Further, the ball nut 6 is engaged with the sliding key 10, and the ball nut 6 is guided by the sliding key 10 so that it can move in the axial direction. Furthermore, an inertia cylinder l/ having a bottomed cylinder shape as a load receiving member is rotatably provided on the seat 9d in the bulging cylinder part qb of the mechanical vibration isolating mechanism t. Inertia cylinder/
A bearing 1 is attached to the catch seat 9d that holds the /. - On the other hand, the bearing 12 has the base of the ball screw 13 screwed into the pole nut base. A is rotatably mounted so that it does not fall out, and a ball screw 13 is mounted on the seat part //a of the inertial member /l located around the base /Ja of the ball screw 13. An inner ring body /lI that slides in the axial direction relative to the ball screw 13 and rotates together with the ball screw 13 is provided so as to be engaged with the ball screw 13 through a plurality of stress transmitting balls /S.

Further, a return spring /A is elastically interposed between the flange of the inner ring body /4' and the inertial cylinder body //,
This return spring /6 presses the inner ring body III against the seat portion //a via the stress transmission pole /S.

That is, the inner ring body lll which is integral with the upper N6 ball screw 13
The load is such that a forward and reverse rotational force is applied to the inertial cylinder // through the stress transmission pole /j.

Therefore, in the above-mentioned mechanical vibration isolator, when the connecting member l is moved in the axial direction (upward or downward) by the supported body, the load column 3 and the pole nut 6 which are integral with this also move together, and the ball nod 6 The screwed ball screw 13 is configured to rotate forward or backward.

On the other hand, when the supported body slowly changes due to temperature changes, the connecting member l moves at a low speed, which causes the ball screw 13 and the inner ring body/9 integrated therewith to move at a low speed. Rotates forward or backward at different speeds. When the inner ring body rotates at a low speed, the stress transmission ball lS that engages with it rotates the inertial cylinder l/ against the elasticity of the return spring /6.

Therefore, no resistance force that suppresses the displacement of the supported body is generated, and low-speed displacement is allowed.

On the other hand, when an external force such as an earthquake causes a high-speed displacement, the load column 3 of the connecting member 1 rotates the ball screw 13 screwed into the pole nut base at high speed in the forward or reverse direction. As a result, the ball screw 13 and the integral inner ring body /4C rotate together, so that the inertial cylinder body /4C rotates together with the ball screw 13.
/ cannot follow the movement of the above-mentioned operation button, and is suppressed by the elasticity of the return spring 16.

[Problems with background technology]

However, the mechanical vibration isolator mentioned above.

For example, it is difficult to prevent vibrations from rapid and minute displacements, such as vibrations caused during Bonzo operation, and it is also difficult to prevent the ball screw from being damaged by minute vibrations over a long period of time. 13 etc. are worn out and damaged, and when used in a nuclear power plant, there are problems with reliability and safety over time.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and is an vibration allocation device equipped with a mechanical vibration isolation mechanism using a ball screw and a Paul naud, in which a sliding friction cylinder is fitted into a load column integrated with a connecting member. The purpose of the present invention is to provide a vibration damping device that aims to suppress rapid and weak displacements, as well as damp vibrations and the like to improve reliability and safety.

[Summary of the invention]

The present invention provides a vibration damping device equipped with a mechanical vibration isolating mechanism using a ball screw and a ball nut, in which a sliding friction cylinder is fitted into a connecting member and a load column of a lower body, and a presser bolt is attached to the load column by a disc spring and the sliding member. A dynamic friction cylinder is fixed through a long hole, a floating cylinder having a flange is fitted to the load column below the sliding friction cylinder, and a holding cylinder by the mechanical vibration isolation mechanism is attached to the floating cylinder. The body is configured to engage resiliently.

[Embodiments of the invention]

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

It should be noted that the present invention will be described with the same reference numerals attached to the same constituent members as in the above-described specific example.

In FIGS. 1 and 1, reference numeral lFi denotes a connecting member connected by a support shaft to a supported body by equal pressure piping in a nuclear power plant, for example, and at one end of this connecting member l, A cylindrical load column 3 and a dust cover cylindrical body are vertically disposed concentrically by set screws S,
A pole nut 6 is attached to the lower end 3a of the load column 3.
is attached. A ball screw 13, which will be described later, is screwed into this pole nut base.

On the other hand, a support member 7 connected to a stationary member is erected directly below the load column 3, and a holding cylinder 9 by a mechanical vibration isolation mechanism g is mounted on the support member 7 around the outer circumference of the load column 3. is fitted in. Moreover, this holding cylinder 9
is formed of a cylindrical portion 9a having a flange 9c and a bulging cylindrical portion 9b, and a sliding key 10 is attached in the axial direction on the inner periphery of this cylindrical portion 9a. Further, a part of the above-mentioned pole nut base is engaged with this sliding key 10, and this ball nut 6 is connected to the above-mentioned sliding key i.

It is designed to be able to slide in the axial direction while being guided by. Furthermore, the bulging cylinder portion qb of the mechanical vibration isolation mechanism g
Inside is an inertia cylinder with a bottomed cylinder shape as a load receiving member.
1 is rotatably provided, and a bearing qt1 for holding the inertial cylinder body // is provided with a bearing qt1.

On the other hand, the bearing 12 has a base of a pole screw 13 screwed into the base of the pole nut. K so that a does not fall
The base of the above-mentioned pole screw /3 is rotatably mounted on the shaft. The seat portion //a of the inertial member body //a located around the inertial member body //a has an inner ring body that slides in the axial direction with respect to the ball screw /3 but rotates integrally with the above-mentioned pole screw 13. /lI is provided so as to be engaged through a plurality of stress transmission balls 15. Moreover, the above-mentioned inner ring body lI
A return spring 16 is elastically interposed between the flange of I and the inertial cylinder l/, and this return spring 1
The elastic force of 6 presses the inner ring body /lI against the seat part //a via the stress transmission pole is.

That is, the load on the inner ring body /4 (which rotates integrally with the ball screw 13) applies forward and reverse rotational force to the inertial cylinder l/ through the stress transmission pole /S. There is.

On the other hand, a sliding friction cylinder /9 having a friction material itr attached to the sliding cylinder 17 is fitted in the load column 3 above the pole nut base so as to be able to slide,
A pair of elongated holes J are bored in a part of this sliding friction cylinder it in the axial direction. Further, to the load column 3 where both of the elongated holes J are located, each pusher and T portco are horizontally fixed via six disc springs and each of the elongated holes. moreover,
The load column 3 below the sliding friction body 19 includes:
The floating cylinder n is fitted so that it can slide, and the collar 9C of the cylindrical part 9a engages with the collar 3a formed at the lower part of the floating cylinder. There is. Furthermore, an extensible coil spring is interposed between the top surface of the flange 9C and a spring receiver hb attached to the upper part of the floating cylinder n, and this coil spring is connected to the floating cylinder. It is held in such a way as to lift up the body N. Moreover, the cylindrical portion 9
At the top of a.

A preload column j formed so as to enclose the six presser bolts 2/ and the coil spring is screwed onto the upper flange Jja of this preload column and the lower part of the sliding friction cylinder/wa. An extensible coil spring 26 is interposed between the tabular spring holder/9a,
This coil spring 26 presses down the sliding friction cylinder/9 and moves away from the floating cylinder. It is designed to come into contact with the top of the

The operation of the present invention will be explained below.

1. When minute vibrations act on the load column 3.

When the load from the supported body received by the load column 3 integrated with the connecting member l is smaller than the frictional force of the sliding friction cylinder/9, the load is applied to the load column 3, the sliding friction cylinder/9, It is transmitted to the floating cylinder 3 and the holding cylinder 9. Therefore, play due to wear does not occur in the ball nut 6 or the ball screw 13 screwed thereon, and damage to the pole nut B that would occur due to this can be prevented. That is, each member to which the load is transmitted has a large spring constant and has a distributing effect on the minute vibrations. Therefore, the relationship becomes linear as shown in the graph of FIG. 3 showing the relationship between the load and the displacement of the load column 3.

When a sudden large load or vibration such as an earthquake is applied to the load column 3.

Since the load from the supported body received by the load column 3, which is integrated with the connecting member 1, is larger than the frictional force of the sliding friction cylinder/9, the sliding friction cylinder 19.

As a result of this, the ball nut 6 of the mechanical vibration isolation mechanism g, which includes the ball screw 13 and the ball nut 6, is moved from the load column 3 to the ball screw/3. Inner ring body/
4', return spring/B, the inertial cylinder body // is rotated via the stress transmission ball 1S to restrain and control vibration. At this point, the relationship between the load acting on the load column 3 and the displacement is as shown in the graph of Figure 3.

3. When displacement due to thermal expansion acts on the load column 3.

If the displacement due to thermal expansion is a load less than the frictional force of the sliding friction cylinder 19, the load is restrained by the sliding friction cylinder/9.

On the other hand, the displacement due to the thermal expansion causes the sliding friction cylinder iq
If the load is greater than the frictional force of , this sliding friction cylinder /q will slip. This displacement is transmitted to the ball nut 6 and ball screw 13, but since it is a static load such as thermal expansion, the mechanical vibration isolation mechanism including the ball nut 6 and ball screw 3 does not operate. No binding force occurs.

Therefore, against displacement due to thermal expansion, no restraint force greater than the frictional force of the sliding friction cylinder 19 acts, and an excessive load does not continue to act on the equipment or piping.

At this time, the relationship between the load acting on the load column due to thermal expansion and the displacement draws a repeating and continuous curve as shown in the graph of FIG.

D. When the friction surface of the sliding friction cylinder/9 is fixed, displacement due to thermal expansion or the like acts on the load column 3. .

Coil spring by the above preload column, 2S, 24
.

When a load larger than the pre-applied load acts on 2A, in the case of a downward direction (+ direction), the holding cylinder t
and the floating cylinder n are spaced apart, and on the other hand, in the upward direction (one direction), the sliding friction cylinder/9 and the floating cylinder 23 are spaced apart. And the load column 3 above. Sliding friction body/? ,
The load that has been transmitted to the holding cylinder 9 via the floating cylinder 3 is transmitted to the holding cylinder 9 or the preload cell J via the load column 3, the sliding friction body 19, and the coil springs J and -6. do.

For this reason, the spring constant is low and the above displacement can be absorbed. Therefore, even if the sliding friction body 19 is stuck to the load column 3, the displacement due to thermal expansion can be absorbed, and the An excessive load will not act on the load column 3 and cause damage.At this time, the relationship between the load acting on the load column 3 and the displacement is as shown in the graph of FIG.

Next, in the embodiment of the present invention shown in FIG. 7, the sliding friction 19 and the holding bolt 21, which constitute the main parts of the present invention, are arranged on the outside of the preload column 2.
This has the same configuration as the specific example described above.

〔Effect of the invention〕

As described above, according to the present invention, in a vibration damping device including a mechanical vibration isolating mechanism g using a ball screw 13 and a ball nut 13, a load column 3 integrated with a connecting member l is provided.
Fit the sliding friction cylinder / into the load column 3 and press the portco / onto the disc springs j, 2 and the sliding friction cylinder /q.
A floating cylinder unit 3 having a flange 23a is fitted into the load column 3 below the sliding friction cylinder /9 through a long hole of the sliding friction cylinder /9. Since the holding cylinder 9 is elastically engaged by the vibrating mechanism, it is not only possible to eliminate wear caused by the ball screw 13, but also to easily suppress minute vibrations. , it is possible to suppress large vibrations such as earthquakes and protect piping, etc.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a vibration damping device that has already been proposed, Fig. 1 is a sectional view showing the main parts of a vibration damping device according to the present invention, and Figs. each graph for,
FIG. 7 is a diagram showing another embodiment of the present invention. l... Connecting member, 3... Load column, 6... Pole nut, g... Mechanical vibration isolation mechanism, 9... Holding cylinder. /7...Sliding cylinder body, /Ir...Friction material, 79...
Sliding friction cylinder. π...long hole, 2/...presser bolt, 22...countersink 1.23...swivel cylinder, 2S...preload column. Applicant's agent Kiyoshi Inomata Figure 2 Figure 7

Claims (1)

[Claims] 1. In a vibration damping device equipped with a mechanical vibration isolating mechanism using a ball screw and a ball nut, a sliding friction cylinder is fitted into a load column that is integrated with a connecting member, and a presser bolt is countersunk in the load column. A spring is fixed through the long hole of the sliding friction cylinder, a floating cylinder having a flange is fitted to the load column below the sliding friction cylinder, and the mechanical vibration isolator is attached to the floating cylinder. A vibration damping device characterized in that a holding cylinder is pressed by a mechanism so as to be elastically engaged. (c) The allocation device according to claim 7, characterized in that the sliding friction cylinder has a friction material attached thereto.