JPS58180852A - Apparatus for damping vibration of mechanical structure - Google Patents

Abstract

PURPOSE:To facilitate the damping of a structure, by allowing a plurality of plates arranged in a hollow part of a mechanical structure to come in contact with each other and to move relatively in the dry state thereby damping vibrations. CONSTITUTION:A bed 1 is formed with the hollow part 2 therein, two fixed plates 3 are secured to the bottom surface 2a with a space therebetween, and three depending plates 4 are hung from a ceiling surface 2b with the plates 4 in contact with the surfaces of the fixed plates 3. When a shock is applied from outside, friction occurs between the contacted surfaces of the fixed plates 3 and the depending plates 4 in the dry state due to the slight vibrations, so that the vibration energy is converted into heat energy and therefore the vibrations can be absorbed and damped.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to vibration damping devices for mechanical structures. This is often used to increase static stiffness. However, when attempting to increase the static stiffness as described above, the mass of the structural material also increases at the same time. Since the vibration frequency does not change significantly and the dynamic stiffness near the resonance point does not change much, 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 in mechanical structures, various considerations have been made to the structure of mechanical structures, such as using castings with high material damping, or leaving some castings in place to increase material damping. Various methods and improvements have been made, including methods for directly connecting machines to concrete foundations.

However, all of the above methods have the disadvantage of being 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 number attenuation rate due to the 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 increase is required. Especially in machines with a wide operating range, it is a good idea to have some form of control over the vibration damping effect. In addition, for forging machines, iron making machines, and other machines that generate large shocks during operation, there is a need to reduce the noise of the machine structures from the viewpoint of the working environment and pollution. In other words, it is desired to stop the propagation of the generated impact and to absorb and attenuate the vibrations transmitted to other machines.

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, which achieves the above object, is to provide a fixing plate that is fixed to the hollow part of a mechanical structure, and to fix it to the fixing plate! The present invention is characterized in that the suspension plate is suspended in the hollow portion by touching the suspension plate, and that a suppressing means for suppressing the fixed plate and the suspension plate from each other is provided.

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 view of the bed of a machine tool taken as an example of a KFi machine structure, and FIG.

FIG. 3 shows a front cross section and a side cross section of an embodiment of the vibration damping device of the present invention applied to the bed. After the internal KFi hollow II 2 of the bed 1 is formed, three suspension plates 4 are formed.
is suspended from the top 2bK. The hanging structure of the hanging plate 4- is such that the bins are assembled on both sides of the upper part of the hanging plate 4-.
It is provided on the top surface 2b of the hollow part 2 and is pivotally supported by a round bearing member 6. Book IJ! In the koji example, the combination of the fixed plate 3 and the hanging plate 4 is provided for 2 m along the longitudinal direction of the bed l, but this may be one set, or three or more sets may be provided. Further, the number of constant plates 3 and hanging plates 4 in each combination K may be different from that of this embodiment. For example, one suspension plate 4 may be brought into contact with one fixed plate 3. Furthermore, in this embodiment, the surfaces of the plates 3 and 4 are parallel to the normal direction 1a of the bed 1, but they may be parallel to the side surfaces or in other directions, depending on the shape of the bed 1 and the manner in which vibrations occur. It can be determined as appropriate.

In the vibration damping device having the above configuration, the bed l has an external
When an impact or periodic excitation force is applied, the bearing member 6. Vibratory forces are transmitted via the bottle 5. and,
Dry friction occurs due to minute sliding on the contact surface between the fixed plate 3 and the suspension plate 4, thereby converting vibration energy into thermal energy, which absorbs and damps vibrations. In addition, the propagation of vibration to other machines or parts connected to the bed IK is suppressed, and the generation of solid sound from the bed 1 itself is also reduced, so that noise prevention is also achieved.

As another embodiment of the present invention, the contact surface between the fixed plate 3 and the suspension plate 4 may be sloped to increase the contact area, thereby increasing the vibration damping effect.

FIG. 4 shows yet another embodiment. This is achieved by installing fluid pressure cylinders 7 as pressing means on both sides of the bed 1, and at the tip of the rod 8 that penetrates the wall surface of the bed 1, a constant plate 3 and a suspension plate 4 are connected with nine presser plates 9. The contact surface pressure between the plates 3 and 4 can be controlled. Changing the contact pressure between the plates 3 and 4 using the fluid pressure cylinder 7
Therefore, it is possible to obtain optimal vibration characteristics according to the vibrations generated by the bed IK.

As described above in detail with reference to embodiments, according to the vibration damping device according to the present invention, a fixed plate is provided in the hollow part of a mechanical structure, and a suspended plate is placed in contact with the fixed plate. are suspended in the hollow part, so sand vibrations are damped by dry friction between the plates. Also, the suppression hand Ii that suppresses the identification board and the suspension board from each other! Since it is possible to adjust the contact surface pressure between the plates by providing the plate, it is possible to obtain optimum vibration damping characteristics depending on the nature of the vibration generated in the mechanical structure.

[Brief explanation of drawings]

jIllIlI#i A perspective view of a bed as an example of a mechanical structure to which the present invention is applied, No. FIG. 4 is a side sectional view of another solid line example. In the figure, 1 is a bed, 2 is a hollow part, 3 is a fixed plate, 4 is a suspension plate, 5 is a bottle, 6 is a bearing member, and is a yFi fluid pressure cylinder. Special fraud applicant Mitsubishi Heavy Industries, Ltd. Fukudai Hoto Patent Attorney Shibe Mitsuishi (and five others) Figure 1

Claims (2)

[Claims] (1) A vibration damping device for a mechanical structure, characterized in that a fixed plate is fixed to a hollow part of the mechanical structure, and a suspension plate is suspended in the hollow part in contact with the fixed plate. (2)) A fixing plate is fixed to a hollow part of the mechanical structure, and a suspension plate is suspended in the hollow part by contacting the fixing plate, and the fixing plate and the suspension plate are connected to each other. A vibration damping device for a mechanical structure, characterized in that it is provided with a suppression means for suppressing vibration.