JPH0242946Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is designed to protect supported objects such as piping in power plants, chemical plants, etc. from vibrations caused by earthquakes, etc. The present invention relates to a vibration damping device installed therein.

Conventionally, as this type of vibration damping device, the relative displacement between the supporting body and the supported body is controlled by the relative displacement in the axial direction between the threaded rod and the nut screwed into the rod. The vibration is damped by converting it into a rotational motion of multiple weights that can rotate relative to each other within a range, damping the vibration by using the inertia of the weight, and then changing the inertia by sequentially connecting the weights according to the acceleration. Devices that prevent resonance between a target and a vibration damping device are known.

However, in the case of such conventional vibration damping devices, although the damping effect is recognized due to the inertial resistance of the weights, the range in which the weights can be rotated relative to each other so that the multiple joint operating points correspond to the resonance point, It is extremely difficult to set the coupling conditions such as the weight of the weights, and if the coupling conditions are not set appropriately, the vibration may be amplified or the vibration damping effect in the normal vibration frequency range may be impaired, making it difficult to achieve the desired result. I can't reach my goal.

The present invention was developed in view of the above-mentioned points of conventional vibration damping devices, and it is possible to easily set conditions for preventing resonance between the supported body and the vibration damping device, and to prevent resonance. The purpose is to effectively prevent this.

Embodiments of the present invention will be described below with reference to the figures. The main cylinder 1 has a lid 2 at one end, an intermediate wall 3 at the middle part, and is open at the other end. On the outside of the lid 2,
It has a handle 2a for connecting to a supported body such as a piping system or a supporting body such as a building.

The threaded rod 4 is rotatably supported by the main cylinder intermediate wall 3 in the middle.

A pair of opposing weights 5 and 6 are provided on a threaded rod 4 within the housing 1a of the main cylinder 1 so as to be rotatable relative to each other at intervals. Oval grooves 5b and 6b are formed on the inner peripheries of the shaft holes 5a and 6a of both weights 6 and 6, respectively.
A rolling ball 7 is inserted between ball receiving recesses 4a, 4b formed at corresponding positions on the threaded rod 4 and b, 6b.

Both ends of a plate-shaped coil spring 8 are respectively locked on the outer peripheries of the two weights 5 and 6, and the weights 5 and 6 allow the rolling balls 7 and 7 to fit into the respective oval grooves 5b and 6b. are located at opposite ends of the That is, each weight 5, 6
can rotate in opposite directions within the range of the oval grooves 5b and 6b, and when a relative rotation occurs between them, the coil spring 8 is unwound to expand its diameter. The outer periphery of the main cylinder 1 is frictionally engaged with the inner surface of the main cylinder 1.

The secondary cylinder 9 has a handle 10a on the lid 10 at one end, a nut 11 screwed into the threaded rod 4 at the other end, and the main cylinder 1
It is inserted into the shaft so that it can be freely moved in and out in the axial direction. Sub cylinder 9
can be connected to a supporting body such as a building or a supported body such as a piping system using a handle 10a. The movement of the auxiliary cylinder 9 in and out relative to the main cylinder 1 is converted into rotational movement of the threaded rod 4 by the nut 11.

Next, the action will be explained. This vibration damping device
Alternatively, one of the sub-tubes 9 is connected to the supported body and the other to the support body. When a slow relative displacement occurs between the supported body and the supported body due to thermal expansion of the supported body, the threaded rod 4 slowly rotates. The two weights 5 and 6 are coupled to each other by a spring 8 and rotate together with the threaded rod 4.
Therefore, slow displacement of the supported body is allowed without difficulty. On the other hand, if a sudden relative displacement occurs between the supported body and the supported body due to an earthquake, etc., the rotation of the threaded rod 4 is suppressed by the inertial resistance of the weights 5 and 6, and the vibration damping effect of the supported body is suppressed. conduct. Furthermore, when this vibration damping device resonates with the vibration of the supported body, the threaded rod 4 rotates with a higher relative acceleration with respect to the weights 5 and 6, depending on the direction of rotation. , one of the weights 5, 6 rotates together with the threaded rod 4, but the other weight 6, 5 cannot follow this due to inertia, and the oval grooves 5b, 6 rotate.
A relative rotation occurs between the threaded rod 4 and one of the weights 5 and 6 within the range b. Due to this relative rotation between both weights 5 and 6, the spring 8 is unwound, and the spring 8 expands its diameter, causing its outer circumferential surface to frictionally engage with the inner circumferential surface of the main cylinder 1, and the rotation of the threaded rod 4. to prevent This changes the vibration of the device and prevents resonance. The spring 8 is selected to have a spring force that can be unwound by a predetermined large reaction force between the threaded rod 4 and the weights 5 and 6 that occurs due to resonance or the like.

As described above, in the present invention, the threaded rod 4 is rotatably provided on the axis inside the main cylinder 1 which can be connected to a supporting body such as a structure or a supported body such as piping. A rolling ball 7 is rotatably inserted into rolling ball holding recesses formed at intervals in the axial direction on the outer periphery of one end, and a pair of disc-shaped weights 5 are attached to this rolling ball receiving portion on the threaded rod 4. , 6 into the threaded rod through hole 5 of each weight 5, 6 so as to be relatively rotatable.
Oval grooves 5b, 6b are formed on the inner circumferences of the weights 5, 6a for rolling the rolling ball 7 within a predetermined rotation angle range, and coil springs bias the weights 5, 6 to rotate in opposite directions. 8 connects the two, and the outer circumference of the coil spring 8 is frictionally engaged with the inner circumferential surface of the main cylinder 1 by expanding the diameter of the coil spring 8 when relative rotation occurs between the two weights 6 and 6. One end of the sub-cylinder 9 is inserted into the main cylinder 1 so as to be able to move in and out of the main cylinder 1 in the axial direction, and the other end is connected to either a supported body or a supporting body. Since a vibration damping device is constructed by fixing a nut 11 screwed onto the threaded rod 4 to one end of this sub-tube 9, slow relative movements such as thermal displacement between the supporting body and the supported body can be prevented. Although this displacement is reasonably tolerated, sudden relative displacement between the supporting body and the supported body due to an earthquake or the like is normally suppressed by the inertial resistance of the weights 5 and 6. Furthermore, when this device resonates with the damping target, either the weights 5 or 6 rotate with a higher relative acceleration, so the diameter of the coil spring 8 is expanded due to the relative rotation between the weights 6 and 6. This can be prevented by frictionally engaging the inner peripheral surface of the main cylinder 1. The frictional engagement operating point of the coil spring 8 can be freely changed by setting the spring constant and diameter of the coil spring 8, and the optimum conditions can be easily selected. Furthermore, the structure is extremely simple and can be obtained at low cost, and the structure can be made compact.

[Brief explanation of the drawing]

FIG. 1 is a sectional view, and FIG. 2 is a sectional view of FIG. 1. 1... Main cylinder, 4... Threaded rod, 5, 6... Weight, 5b, 6b... Oval groove, 7... Rolling ball, 8
...Coil spring, 9...Sub-tube, 11...Natsuto.

Claims (1)

[Claims for Utility Model Registration] A threaded rod is rotatably provided on the axis in the main cylinder that can be connected to either the supporting body or the supported body. A rolling ball is rotatably inserted into the rolling ball holding recesses formed at intervals, and a pair of disc-shaped weights are fitted into the rolling ball corresponding portions on the threaded rod so as to be relatively rotatable, and each weight is inserted through the threaded rod. forming an oval groove in the inner circumference of the hole for rolling the rolling ball within a predetermined rotation angle range, and connecting both weights with a coil spring that urges them to rotate in opposite directions; The outer periphery of this coil spring faces near the inner peripheral surface of the main cylinder so that when relative rotation occurs between both weights, the diameter of the coil spring expands and frictionally engages with the inner peripheral surface of the main cylinder. In addition, one end of the sub-cylinder is inserted into the main cylinder so as to be able to move in and out in the axial direction, and the other end can be connected to either a supported body or a supporting body, and the threaded rod is attached to one end of the sub-cylinder. A vibration damping device characterized by a fixed nut that is screwed into the.