JPS6357657B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vibration-isolated mechanical foundation intended for mechanical foundations whose main vibration is horizontal vibration. Compressors, vibrating screens, etc. transmit large vibrations to the surrounding ground via the machine foundation due to their vibrations, causing so-called vibration disturbances. Also, such a foundation shortens the life of the machine,
This causes vibration disturbances that reduce the accuracy of the finished product. Conventionally, as a means of vibration isolation for machine foundations that experience large horizontal vibrations as described above, methods have been generally used, such as interposing an elastic material such as rubber or a spring between the equipment and the machine foundation, or enlarging the bottom of the foundation. There is. However, elastic materials such as rubber cannot be expected to be effective in preventing vibrations from the machine foundation in the case of large equipment that generates large vibrations, and when springs are used, the vibration to the machine foundation cannot be expected to be effective. Although the transmission can be reduced to some extent, it has the disadvantage of increasing the vibration of the equipment, and is therefore not applicable especially in cases where the vibration of the equipment itself causes problems. In addition, the method of enlarging the base of the foundation reduces the vibration of equipment and machine foundations, but it has the disadvantage of making the shape of the machine foundation excessively large, and the current situation is that we compromise on a foundation of an appropriate size for practical purposes. It is. A feature of the present invention is that a pseudo-resonator with an extremely small amount of damping is attached to the machine foundation, which is built on a material with an extremely large amount of damping, in accordance with the external force frequency, and complex analysis is performed, which is different from conventional mechanical foundation design theory. method (welding method that takes into account the phase difference), we have obtained a theoretical solution for dynamic vibration absorption, and we have achieved extremely significant vibration isolation even in any frequency range other than the resonance point, which was not possible with conventional methods. Therefore, it is possible to obtain a vibration isolation effect not only at the external force frequency generated by the equipment, but also in the predominant period range of the surrounding ground that causes vibration pollution, and the size of the false resonator can be determined by theoretical analysis. According to the research, it is possible to obtain a remarkable vibration damping effect even with an extremely small pseudo-resonator, and furthermore, when placing pseudo-resonators in various locations, the weight of each pseudo-resonator must be moved to adjust the length of the fulcrum of the elastic support. After adjusting the natural frequency of the pseudo-resonator by increasing or decreasing
By connecting the weights of the pseudo-resonator, it is possible to precisely match the natural frequency of the pseudo-resonator to the external force frequency generated by the device, thereby increasing the vibration-proofing effect. The object of the invention is to provide an effective anti-vibration mechanical foundation having the above-mentioned characteristics. The present invention will be explained below based on embodiment figures. FIGS. 1 and 2 are examples showing the arrangement of a pseudo resonator, a device that generates an external force, and a machine foundation. A plurality of devices 1 that generate vibration are fixed to the upper end of the machine foundation 2. A plurality of spaces 6 are provided in a part of the foundation 2, and false resonators 5 are attached to the spaces. The pseudo-resonator 5 is composed of a weight 3 and an elastic support 4, and after adjusting the length of the fulcrum of the elastic support by moving the weight up and down, the weights are connected with a connecting member 7 made of a steel rod, a steel plate, etc. By making the dynamic characteristics of the individual weights interfere with each other, vibrations are damped and vibrations generated by the equipment are effectively absorbed. Specific examples are shown in Table-1. Table-1
(A) is a case where the weights are independent, and the vibration isolation frequencies are strictly separated and the amplitude value is A1. On the other hand, in (b), each weight is connected and integrated with a thin-walled steel tube of φ101.6, which results in a smaller amplitude value A2 and a better vibration-proofing effect. In addition, H2, H4, and H7 in the table indicate the vibration measurement values at the left end, center, and right end of the foundation in Figure 2. In addition, the conventional construction method using the foundation and weight as the measurement location, Japanese Patent Application No. 53-96249 (Japanese Patent Application No. 55-26304)
(The length of the fulcrum of the elastic support is adjusted by moving the weight up and down.) Table 2 shows the results of comparative measurements of vibrations between the construction method according to the present invention and the construction method according to the present invention.

[Table] Adjustment of the natural frequency of the pseudo-resonator by moving the harpoon up and down.
Next, a method for connecting the three weights will be explained. First, prior to pouring concrete for foundation 2,
A sleeve 8 through which a connecting member 7 is inserted is installed horizontally inside the foundation at the height where the weight of the false resonator 5 is installed, and then foundation concrete is poured. Subsequently, a weight having a metal fitting at the end for fixing the connecting member 7 and an elastic support are fixed in the hollow space of the foundation. The previously attached connecting member 7 is connected to the fastening metal fitting provided at the end of the weight by a known means such as bolts or welding. (Not shown) Although the actual diagram shows three pseudo resonators connected in series, the present invention is not limited to this, and according to the measurement results, two of the plurality of weights are , three or four... are connected to produce the above effect. FIG. 3 shows another embodiment, in which a steel rod of an elastic support, which is an H-beam steel beam 10, is fixed across the left and right foundations 9, 9, and both ends of the steel beam 10 are connected to the foundations 9, 9. It protrudes outward in a cantilever type, and consists of a pseudo-resonator 12 with an extremely small amount of attenuation, with supporting steel and weights 11 placed orthogonally on the protruding part. No. 108907 (Unexamined Japanese Patent Publication No. 55-36636)
In contrast to the horizontal movement of a single weight 11 by long-distance operation, which has been filed as a patent application, the present invention connects the weights 11 with a connecting member 13, integrates them, moves them horizontally, and provides vibration isolation. In addition, the fact that the entire pseudo-resonator 5 is housed within the space 6 formed in the machine foundation 2 has the advantage that the pseudo-resonator 5 does not become crowded depending on the location, and also has the advantage that the pseudo-resonator 5 does not vibrate during use. This is advantageous because it prevents the danger of humans coming into contact with it. As mentioned above, when installing a plurality of false resonators on a machine foundation, the vibration-proof foundation of the present invention moves the weight vertically or horizontally so as to increase or decrease the length of the fulcrum of the elastic support. After adjusting the natural frequency of the resonator, by connecting the weights of an appropriate pseudo-resonator with a connecting material, the vibration of a machine foundation installed on the ground where the resonance point is not clear can be effectively reduced. Therefore, it is possible to effectively prevent vibrations transmitted to the ground. It should be noted that the present invention can be applied to vibration isolation of foundations that are subject to a wide range of vibrations without changing the gist thereof.

[Brief explanation of drawings]

Fig. 1 is a plan view of a vibration-proof mechanical foundation showing the arrangement of the pseudo resonator of the present invention, equipment that generates external force, and the machine foundation, Fig. 2 is a sectional view of Fig. 1, and Fig. 3 is the invention of the present invention. FIG. 3 is a plan view of another embodiment of the invention. 1... Equipment that generates vibration, 2... Mechanical foundation, 3
... Weight, 4 ... Elastic support, 5 ... False resonator, 6 ... Vacancy, 7 ... Connecting material, 8 ... Sleeve, 9 ... Foundation, 10 ... Steel beam, 11 ... Weight , 12... false resonator, 13... connecting material, 14...
Gear motor, 15... Jack, 16... Drive connection shaft, 17... Gear box.

Claims (1)

[Claims] 1 A machine foundation on which equipment that generates vibration is installed is equipped with multiple pseudo-resonators with extremely small attenuation made of weights and elastic supports such as steel rods and steel plates, and the natural frequency of the pseudo-resonators is In order to adjust the vibration, the length of the fulcrum of the elastic support is increased or decreased, and two or more weights of the pseudo-resonator are connected to each other, so that the dynamic characteristics of the individual weights interfere with each other. .