JPH0220927B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for vibrating a specimen in a vibration generator.

Generally, when performing a vibration test, a vibration table is fixed to the drive part of a vibration generator, and a specimen is fixed to this vibration table. However, when a plate-shaped vibration table a is used to vibrate in the P and Q directions as shown in Fig. 1, when a force in the compression direction P is applied to the vibration table a, the vibration table a buckles as shown in the figure. There was a problem in that the uniformity of the test could not be ensured due to the unintended extra vibration being applied in the direction of the arrow R. In addition, even if the specimen is the same, if the thickness and shape of the plate-shaped vibration table a differ, different results will be obtained for each test, resulting in an unreliable vibration test. .

The present invention solves these problems, prevents buckling of the vibration table, reliably transmits the vibration of the drive part of the vibration generator to the specimen, and allows accurate vibration tests to be performed. The purpose of this study is to provide a method for exciting specimens. Therefore, the features of the present invention are as follows:
It is equipped with a plate-shaped vibration table on which the specimen is attached, and a drive part of a vibration generator is fixed to both ends of the plate-shaped vibration table in the direction of the drive axis, and the positive side of the input signal is transmitted to one of the vibration generators. and input the negative side signal of the above input signal to the other opposing vibration generator, and drive the driving parts of both vibration generators only in the tensile direction. The point is that it is vibrated and driven only by tensile force.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

In Figure 2, 1 and 1 are vibration generators 2 and 2, respectively.
The fixed parts 1, 1 are provided with drive parts 3, 3, respectively, and the drive parts 3, 3 are left and right opposed, and the vibration generators 2, 2 are connected at a predetermined interval.
will be placed. Reference numeral 4 denotes a plate-shaped vibration table fixed horizontally between the drive parts 3 and 3 of the vibration generators 2 and 2, and the vibration table 4 has both ends in the direction of the drive axis G (left and right in the drawing). These drive parts 3, 3 are fixed to both ends). A specimen 5 to be subjected to a vibration test is attached to this plate-shaped vibration table 4.

Therefore, the pair of vibration generators 2, 2 facing each other always act on only the tensile force in the H direction so as not to apply compressive force to the vibration table 4, and as shown in FIGS. 3 and 5, the input Signal A is amplified by preamplifier 6, rectified, and divided into voltage signals B and C.
The signals D and E are input into respective power amplifiers 7 and 7, and are further amplified and sent to the drive coils of the respective vibration generators 2 and 2 to drive the drive units 3 and 3. Signals D and E have pulsating flow waveforms, and only tension in the H direction acts. Moreover, the current does not become zero as shown in the signals D and E shown in FIG. 5, but maintains a minimum constant value S, and the vibration table 4 is moved by a force proportional to the momentary absolute value difference between the two signals D and E. It is starting to be excited.

The tensile force based on this minimum constant value S acts to more reliably prevent the plate-shaped vibration table 4 from performing the curved vibration R as shown in FIG. (In the present invention, it goes without saying that the case where S=0 is also included within the technical scope.

It is also possible to form a circuit as shown in FIG. 4 and use one power amplifier 8 to drive the two vibration generators 2, 2, where 9, 9 indicates a power source, and each signal A to The D waveform is the same as in FIG.

Although the vibrating table 4 is shown in a horizontal position in FIGS. 2 and 3, it may be in a vertical or oblique direction. In addition, as shown in FIG. 6, vibration generators 2a and 2a are arranged facing each other, and vibration generators 2b and 2b are arranged facing each other on the other opposite side to apply force in the two axes X and Y directions. When shaking, it is sufficient to similarly drive a pair of opposing vibration generators using only the force in the tensile direction. It goes without saying that the present invention can also be applied to vertical and horizontal two-axis excitation and three-axis excitation.

Further, the vibration generator 2 may be an electrodynamic vibration generator or an electro-hydraulic vibration generator, and is not limited.

With the above-described configuration, the present invention can always maintain a flat plate shape without being curved and deformed as shown in FIG. 1 even if the vibration table 4 is a thin plate, and can provide the desired high-precision vibration to the specimen. Can be added. Therefore, accurate vibration test results can be obtained.

[Brief explanation of drawings]

FIG. 1 is a front view of main parts showing a conventional vibration excitation method. Fig. 2 is a front view of main parts showing one embodiment of the present invention, Figs. 3 and 4 are control circuit configuration diagrams of the vibration generator, respectively, and Fig. 5 is a timing chart in Figs. 3 and 4. The chart diagram and FIG. 6 are perspective views of other embodiments. 2... Vibration generator, 3... Drive unit, 4... Vibration table, G
...Drive shaft center.

Claims (1)

[Claims] 1. A plate-shaped vibration table 4 to which a specimen 5 is attached is provided, and the drive parts 3, 3 of the vibration generators 2, 2 are fixed to both ends of the plate-shaped vibration table 4 in the direction of the drive axis G, and the input signal A is A signal D on the positive side of the input signal A is inputted to one vibration generator 2, and a signal E on the negative side of the input signal A is inputted to the other vibration generator 2 facing the input signal A. drive parts 3, 3, respectively, only in the tensile direction,
A vibrating method characterized by driving the plate-shaped vibrating table 4 to vibrate with only a tensile force.