JPS60132148A - Dynamic vibration absorber - Google Patents

Abstract

PURPOSE:To enable to asorb vibration in low frequency region by a structure wherein a weight and an elastic vibration absorbing material are joined together and cuts or cutouts are provided on the vibration absorbing material in order to reduce the spring constant without increasing the thickness of the vibration absorbing material. CONSTITUTION:A dynamic vibration absorber is composed by joining a foamed material 2 with a weight 1 and joins to a matter to be absorbed its vibration 5. When the matter to be absorbed its vibration 5 vibrates, resonance occurs between the weight 1 and the foamed material 2 so that the weight 1 vibrates dynamically at the frequency determined by the spring constant of the foamed material 2 and the weight of the weight 1, resulting in reducing the vibration of the matter to be absorbed its vibration 5. In addition, the spring constant of the foamed material 2 is made small by providing cuts 3 or cutouts 4 on the foamed material 2, resulting in lowering the resonant frequency between the weight 1 and the foamed material 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a dynamic vibration reducer used for damping vibrations of electric motors, compressors, etc.

Structure of a conventional example and its problems FIG. 1 is a perspective view of a conventional dynamic vibration absorber. Reference numeral 101 indicates a heavy material that should serve as a weight, such as an iron plate or a lead plate. 1
The reference numeral 02 is a flat plate-shaped light source M1, L fixed to the weight 101, and is made of urethane or the like. In the dynamic vibration absorber configured as described above, the foam material 2 is made of a flat plate, so when the frequency to be damped is low, the thickness t is increased in order to reduce the spring constant. Therefore, ■ The amount of materials used is large and the price is high. ■ The thickness of the dynamic vibration absorber increases and the shape becomes larger. ■ The volume of the joint between the object to be absorbed and the dynamic vibration absorber was too large, and installation was subject to space constraints.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks, and aims to reduce the thickness of a dynamic vibration absorber and absorb vibrations in a low frequency range.

DESCRIPTION OF THE INVENTION To achieve this objective, the present invention comprises a weight and a resilient foam material having notches or notches, which reduces the spring constant and reduces the thickness of the foam material. It is possible to absorb vibrations in the low frequency range without increasing the vibration.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIGS. 2 to 4, reference numeral 1 denotes a heavy material that serves as a weight made of a rectangular flat plate, and is made of an iron plate, a lead plate, a copper plate, or the like. 2 is an elastic rectangular flat foam layer bonded to the weight 1, and is made of urethane or the like. 3
The notch 4 provided in the foamed material 2 is a notch provided in the foamed material 2. 5 is an object to be vibration-absorbed, and a foam material 2 is attached thereto.

In the above structure, the weight 1 is received on the foam material 2 to form a dynamic vibration absorber, and this is joined to the object 5 to be damped as shown in FIG. When the object 6 to be vibration-absorbed vibrates, resonance occurs between the weight 1 and the foaming material 2, dynamic vibration absorption is performed at a frequency determined by the spring constant of the foam material 2 and the weight of the weight 10, and the object 6 to be vibration-absorbed vibrates.
vibration is reduced. At this time, due to the notches 3 or 4 provided in the foamed material 2, the spring constant of the foamed material 2 is reduced, and the resonance frequency is therefore reduced.

Figure 6 shows this change. The horizontal axis shows the resonant frequency, and the vertical axis shows the vibration absorption level, and the parameters are shown in the notch 4 of the foam material 2. It was measured by cutting depth of 30 degrees and used as a spring constant. The one with the smallest spring constant is 1, and the next one is 2.
, the highest one is set to 3. As can be seen from this figure, the lower the spring constant, the lower the frequency indicating the maximum absorption amount, and the larger the vibration absorption frequency band.

In the above embodiment, the foamed material 2 is made of urethane, but any other material having elasticity and springiness may be used. Also, notch.

The shape of the cutout and the position in one direction may be arbitrary, as long as the spring constant is small.

Effects of the Invention As described above, the dynamic vibration absorber of the present invention is made by joining a weight and an elastic vibration absorber having a cutout or multi-notch portion, and the spring constant can be increased without increasing the thickness of the vibration absorber. This makes it possible to reduce vibration in the low frequency range.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional dynamic vibration absorber, FIG. 2 is a perspective view of a dynamic vibration absorber according to an embodiment of the present invention, and FIG. 3 is a perspective view of a dynamic vibration absorber according to an embodiment of the present invention. FIG. 4 is a cross-sectional view showing a dynamic vibration absorber according to an embodiment of the present invention bonded to an object to be vibration-absorbed, and FIG. 6 is a diagram showing changes in the vibration-absorbing state when the spring constant of the foam material changes. be. 1... Weight, 2... Foaming material (vibration absorbing material)
, 3... Notch, 4... Notch. Name of agent: Benkoishi Toshio Nakao and 1 other person 1st
Figure 2

Claims (1)

[Claims] A dynamic vibration absorber in which a weight and an elastic vibration-absorbing material are joined, and the vibration-absorbing material has a cutout or a cutout.