JPS58180851A - Apparatus for damping vibration of mechanical structure - Google Patents

Abstract

PURPOSE:To facilitate the damping of a structure, by hanging a plurality of plates in contact with each other in a hollow part of a mechanical structure, and allowing the plates in contact to move relatively in the dry state thereby damping the vibrations. CONSTITUTION:A bed 1 is formed with the hollow part 2 therein, and the plurality of plates 3 are hung in the hollow part 2 with the adjacent surfaces of the plates in contact with each other. Friction between the contacted surfaces of the plates 3 in the dry state occur due to the slight sliding, so that the vibration energy is converted into heat energy and therefore and vibrations can be absorbed and damped.

Description

[Detailed description of the invention] The present invention relates to a vibration damping device for mechanical structures.

In order to improve the rigidity of a mechanical structure, the static rigidity is often increased by increasing the thickness or size of the structural member or adding supporting members. However, when increasing the static stiffness as described above, the mass of the structural material also increases, so the natural frequency of the mechanical structure is basically determined based on the ratio of stiffness to mass. does not change significantly, especially the dynamic stiffness near the resonance point, so it is often insufficient to prevent automatic vibrations such as chatter vibrations of machine tools. On the other hand, in order to prevent unstable vibrations of mechanical structures, various arrangements are made for the construction of mechanical structures. Various attempts have been made and improvements have been made, including methods of increasing the amount of water and methods of directly connecting the machine to the concrete foundation.

However, the above-mentioned means have the disadvantage that they are both costly. In terms of cost, it is advantageous to use sheet metal for mechanical structures, but in this case there is no problem in maintaining static rigidity, but with regard to dynamic rigidity, the logarithmic damping rate due to the steel casting structure is about 0.1 to 0. Since the material damping of the sheet metal decreases by 0.01 to 0.04 compared to 2, some kind of active damping or increase is required. Especially in machines with a wide operating range, it would be ideal to be able to control the vibration damping effect in some way. In addition, for forging machines, iron-making machines, and other machines that generate large shocks during operation, the work environment and pollution -
There is a need to reduce the noise of mechanical objects due to various reasons. In other words, it is desired to absorb and attenuate vibrations in order to stop the propagation of the generated shock and prevent it from propagating to other machines and buildings.

The present invention was made in view of the above-mentioned situation, and an object of the present invention is to increase structural damping in a mechanical structure and improve shock absorption ability.

The gist of the present invention for achieving the above object is that a plurality of plates are suspended in a hollow part of a mechanical structure in contact with each other, and in addition, a suppressing means for pressing the plurality of plates against each other is provided. It is characterized by

Hereinafter, a vibration damping device according to the present invention will be explained in detail based on embodiments shown in the drawings.

Fig. 1 shows a perspective appearance of a ped of a machine tool taken as an example of a mechanical structure, and Figs. 2 and 3 show a front view of an embodiment of the vibration damping device of the present invention applied to the ped. A cross section and a side section are shown. A hollow part 2 is formed inside the ped 1, and a plurality of boards 3 are suspended in the hollow part 2 with adjacent boards 3 in surface contact with each other. The suspension structure of the plate 3 is such that pins 4 protruding from both sides of the upper part of the plate 3 are pivotally supported by bearing members 5 provided on the inner top surface 2a of the hollow part 2. In this embodiment, two groups of plates 3 are suspended along the longitudinal direction of the ped 1, but this may be one group, or three or more groups, which can be selected as appropriate depending on the size of the hollow part 2. can. Further, in this embodiment, the plane of the plate 3 is parallel to the front surface 1a of the ped 1, but the plane of the plate 3 may be parallel to the side surface 1bK or in any other direction. It can be determined as appropriate.

In the vibration damping device configured as described above, when an impact or a circumferential excitation force is applied to the ped 1 from the outside, the vibration force is transmitted from the ped 1 to the plate 3 via the bearing member 5 and the pin 4.

Then, dry friction occurs due to minute sliding on the mutual contact surfaces of the plates 3, and - vibration energy is converted into thermal energy,
Vibration damping is achieved along with vibration absorption. In addition, the propagation of vibration to other machines or parts connected to the ped 1 is also suppressed, and the generation of solid sound from the bed 1 itself is also reduced, so that noise prevention is also achieved.

FIG. 4 shows another embodiment of the invention. This increases the contact surface by adding opposite slopes 1 to adjacent plates 3 that are suspended in contact with each other in the hollow part 2,
This increases the damping effect.

FIG. 5 shows yet another embodiment. This is achieved by installing fluid pressure cylinders 6 as pressing means on both sides of the ped 1, pressurizing the 3 groups of plates from both sides with a presser plate 8 provided at the tip of the rod 7 that penetrates the wall surface 1a of the ped 1, and pressurizing the 3 groups of plates from both sides. This allows the contact surface pressure between the two to be controlled.

As described above in detail with reference to embodiments, according to the vibration damping device according to the present invention, a plurality of plates are suspended in a hollow part of a mechanical structure in contact with each other. Vibration is damped by dry friction. In addition, a suppressing means for pressing a plurality of plates against each other is provided to reduce the contact surface pressure between the plates by 11.
By adjusting the contact surface pressure, it is possible to obtain an optimal vibration damping characteristic according to the vibration generated in the mechanical structure.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a ped as an example of a mechanical structure to which the present invention is applied, FIG. 2 is a front cross-sectional view of an embodiment of the present invention, FIG. 3 is a side cross-sectional view, and FIG. FIG. 5 is a side cross-sectional view of another embodiment of the invention. FIG. 5 is a cross-sectional view of still another embodiment. In the drawing, 2 is a hollow part, atJ plate, 4 is a pin, 5 is a bearing member, and 6 is a fluid pressure cylinder.

Claims (1)

[Claims] (1) A vibration damping device for a mechanical structure, characterized in that a number of plates in the hollow part of the mechanical structure (VC1l) are suspended in contact with each other. (21) A vibration damping device for a mechanical structure, characterized in that a plurality of plates are suspended in contact with each other in a hollow part of the mechanical structure, and a pressing means for pressing the plurality of plates against each other is provided.