JPS58174739A - Vibration damping structure for mechanical structure - Google Patents

Abstract

PURPOSE:To absorb the external shock effectively by contacting a plurality of frame board members contained in a hollow section of a mechanical structure each other and against the inner wall of said hollow section thus producing dry frictional function. CONSTITUTION:A hollow section is formed in a bed body 1 of a machine tool and a pair of frame board members 2, 3 are contained in said hollow section while facing each other such that they are connected each other and contact against the inner wall of the hollow section. Coupling rods 4 are coupled to said members 2, 3 such that said members 2, 3 can move to the left and right through said rods 4 and the connecting face pressure can be adjusted through slight motion of the inclined face on the mutual connecting face. Consequently the external shock can be absorbed by dry friction due to the contact.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to precision machines such as machine tools, processing machines such as forging machines and rolling machines, and other mechanical structures in general in which vibration damping is particularly important, and particularly to vibration damping structures with improved dynamic rigidity. .

Conventional 9 In order to improve the rigidity of a machine, the static rigidity is often increased by increasing the thickness or size of its structural members or by adding supporting members. However, as mentioned above, increasing the static stiffness also increases the mass of the structural members, so the natural frequency of the mechanical structure, which is basically determined based on the ratio of stiffness to mass, will not change significantly. In particular, the dynamic stiffness near the resonance point does not change much, so it is often insufficient to prevent self-excited vibrations such as chatter vibrations of machine tools, etc.

On the other hand, in order to prevent unstable vibrations of mechanical products, consideration has been given to the construction of mechanical structures, such as the use of castings with high material damping.

Furthermore, various methods have been tried and improved, such as a method of increasing material damping by leaving some of the casting sand, such as directly connecting the machine to the cosiclete foundation.
There is no problem in maintaining static image quality, but regarding dynamic stiffness, the logarithmic damping rate of 0.1 to 0.2 due to the casting structure,
This is because the material damping of the sheet metal decreases by one order of magnitude, from 0.01 to 0.04.

) In machines where some positive damping increase is required and the operating range is wide, it was desired to be able to control the vibration damping effect in the form of an equivalent force. In addition, for forging machines, iron-making machines, and other machines that generate large shocks during operation, it is required to reduce the noise of machine structures from the viewpoint of the working environment and pollution.1. It has been desired to absorb and attenuate vibrations in order to eliminate their propagation to machinery and buildings.

In view of the above-mentioned current situation and requirements, the present invention adds structural damping to nine mechanical structures and provides one piece of shock absorption. Yoai 5
6[11i'llm-gao6゜], the gist of which is to store a plurality of frame-shaped plates in the hollow part of a 9-machine structure, and to store the same frame-shaped plates with each other and with the open frame cover plate and the above. A vibration damping structure for a mechanical structure characterized in that the inner surface of the horizontal spear structure is configured to contact each other, and a plurality of frame-shaped plates are housed in a hollow part of the mechanical structure, and the frame-shaped plates The frame-shaped plate material and the inner surface of the mechanical structure are configured so as to be in contact with each other, and the contact portions of the frame-shaped plate materials are formed into a tapered shape, and means for slidingly pressing the frame-shaped plate materials against each other is provided. A vibration damping structure for a mechanical structure is provided.

The present invention will be explained in detail below using examples.

Fig. 1 is a perspective view of the bed of a machine tool, which is an example of the mechanical structure to which the present invention applies, Fig. 2 is a vertical side view of the bed, and Fig. 6 is a sectional view taken along the line ■-■ of Fig. 2. be. In these figures, (1) is a bed main body, and a hollow part is formed inside. t21, (3) are relative to each other in the hollow part:
A pair of frame-shaped plates are housed and installed facing each other, and there is a space between these frame-shaped plates and between these frame-shaped plates and the bed body i11.
and the inner surface of the hollow part are in contact with each other over a wide range.

In addition, the connecting rod (21, (31)
4) penetrates the bed (1), and a silicator (5) disposed outside is connected to the connecting rod (4), and the position of the frame plate (2+, (3)) is as shown in Fig. 2. It is now possible to move left and right in the center.Furthermore, frame-shaped board material (2+
(3) The mutual contact surfaces form a minute inclined surface (Taber).

According to the above structure, the bed as a mechanical structure (1)
However, if an impact or periodic excitation force is applied from the outside, the frame plate material (2) from the bed (1).

The vibration force is transmitted to (3), but at this time the bed +11
Due to the dry friction at the contact area between the inner surface of the hollow part and the frame plate material (2), (31) and the mutual contact area, the vibration energy A becomes the thermal energy A. It absorbs vibrations and produces a damping effect.It also suppresses the propagation of vibrations to other machines or parts (not shown) connected to the bed (1), and also reduces solid-state sound generated by the mechanical structure itself. It also has a noise prevention effect.Also, by operating the silicator (5), 1 frame plate material + 2)
, (3) are pressed against each other by sliding, and the frame-shaped plates (2+,
f3) Mutual contact surface pressure and frame plate material +21, (
By controlling the contact pressure between 31 and the inner surface of the hollow part of the bed (1), it is possible to set the contact pressure that can maximize the above-mentioned vibration damping effect and aim for the maximum dynamic rigidity improvement effect. Adaptive control is also possible to realize an optimal adjustment mechanism according to external force conditions.

The frame-shaped plate material (21, (3)) is not limited to a pair of U-shaped cross-sectional materials as shown in Fig. 3, but may be arranged in multiple pairs as shown in Fig. 4, or as shown in Fig. 5. Two different modifications are possible, such as a comb-shaped cross-section material.

It can also be used as a means to slide and press frame-shaped plate materials.

A hand-cranked bolt may be used instead of the shilling (5).

When there is no need to control the contact surface pressure, such as when the working range of the mechanical device is narrow, this sliding pressing means and the frame-shaped plate (2
+, The inclined surface (taper) in (3) is unnecessary.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of one practical example of the present invention, Fig. 2 is a vertical side view, Fig. 5 is a cross-sectional view taken along the line -■ of Fig. 2, and Fig. 4 is another practical example of the present invention. FIG. 5 is a cross-sectional side view of still another embodiment of the present invention. (1)...Bed; (21, (3)...Frame deaf board material; (5)...Syringe. 1 scolding 2 round plate 4 round□□□□-□--lower blade

Claims (2)

[Claims] (1) A plurality of frame-shaped plates are housed in a hollow part of the mechanical structure, and the frame-shaped plates are in contact with each other and the frame-shaped plates and the inner surface of the mechanical structure are in contact with each other. Vibration damping structure for mechanical structures. (2) A plurality of frame-shaped plates are housed in a hollow part of the mechanical structure, and the same frame-shaped plates are configured to contact each other and the same frame-shaped plates and the inner surface of the mechanical structure; A vibration damping structure for a mechanical structure, characterized in that the contact portions of the plate materials are formed into a tapered shape, and a means for suppressing sliding of the same frame-shaped plate materials relative to each other is provided.