JPH02176534A - Experimental apparatus for loading dynamic centrifugal force - Google Patents

Abstract

PURPOSE:To stably carry out an excitation test upto a high frequency range by mounting direct an actuator for excitation on a rotational arm. CONSTITUTION:A shaft 8 is made to revolve against a slide bearing 7 when a centrifugal force F1 is exerted, and a supporting matter 15 for test sample is swung up horizontally by the centrifugal force produced from a rotation of the rotational arm 4. The tip end part of a piston rod 6 on the actuator 9 for excitation is connected direct to the supporting matter 15 and supported to an actuator housing 10 by the slide bearing 18 which is capable of freely sliding in both directions of the revolution and the shaft; therefore, the rod 6 is also made to revolve following up to the swinging movement. If center axes 0-0 of the rod 6 and the swinging movement coincide, the relation between the rod 6 and the supporting matter 15 is same for either cases of swinging up and down, and a fluid pressure is supplied alternately to rooms at both sides divided by the rod 6 in a cylinder of the housing 10. The supporting matter 15 can be thereby excited in stable condition.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a dynamic centrifugal force loading experimental device that performs tests by simultaneously applying centrifugal acceleration and vibration acceleration to scale models of the ground, structures, etc. In particular, the present invention relates to a dynamic centrifugal force loading experimental device suitable for conducting seismic tests using stable excitation up to a high frequency range.

[Conventional technology]

When conducting an experiment by creating a scale model 4 If the test is conducted in a normal gravitational field, it is difficult to reproduce the stress due to the weight of the specimen. The centrifugal force loading experiment device basically attaches a scale model of the ground, structure, etc. to be tested at the tip of a rotating arm, and rotates the rotating arm at high speed in a horizontal plane for one rotation. Apply centrifugal acceleration to 1/N
This creates a state equivalent to applying N times the gravitational acceleration to the scale model. Techniques related to this type of device include, for example, the technique described in Japanese Utility Model Publication No. 61-46439.

[Problem to be solved by the invention]

In the above-mentioned centrifugal force loading test equipment, when an excitation mechanism is installed to apply centrifugal acceleration and vibration acceleration to the specimen at the same time to perform an earthquake resistance test on the specimen, the excitation mechanism must be installed in a horizontal plane. A sample holder is suspended by a pair of leaf springs from a shaft provided at the tip of a rotating rotary arm, an excitation actuator is attached to the shaft that swings together with the sample holder, and a specimen is placed inside the sample holder. Therefore, a mechanism that vibrates the sample support is generally considered. The shaft is a housing.

It is supported by a thrust bearing consisting of a rotating plate and a sliding plate, and two spherical bearings, and the centrifugal force caused by the rotation of the rotating arm causes the sample support to swing into a horizontal position.

As exemplified by this mechanism, when a swinging object is generally excited at the tip of a rotating arm, a vibration actuator is attached to the swinging part to vibrate the sample support. ing.

According to this structure, the excitation reaction force generated by the excitation actuator must be supported by a bearing mechanism such as a sliding plate that connects the oscillating part. There was a problem in which deformation due to the excitation reaction force due to weakness or backlash had an adverse effect on the excitation performance.6 The object of the present invention is to solve the problems of the prior art described above, and to solve the problem that the attachment of the excitation actuator is It is an object of the present invention to provide a dynamic centrifugal force loading experimental device that has strong rigidity, is capable of stably imparting vibration to a sample support, and is capable of performing stable vibration tests up to a high frequency range.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a vibration actuator directly attached to a rotating arm, a piston rod of the vibration actuator having its central axis aligned with the central axis of the swinging motion of the sample support, and The piston rod is directly connected to the sample support.

[Effect]

In the dynamic centrifugal force loading experimental device of the present invention, the sample support swings and swings up due to the centrifugal force received by one rotation of the arm.
By aligning the center axis of the piston rod with the center axis of the rocking motion when in the horizontal position, the piston rod swings up and rotates at the same time, changing the positional relationship between the piston rod of the vibration actuator and the sample support. does not change, so the piston rod can be connected directly to the sample support,
It becomes possible to vibrate the sample support.

This mechanism allows the sample support to be stably excited by the vibration actuator attached to the rotating arm.
Furthermore, by attaching the vibration actuator, it is possible to increase the rigidity of the part, and therefore high performance vibration up to a high frequency range can be realized.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing an outline of a dynamic centrifugal force loading experimental device according to the present invention.

The electric motor 1 is configured to rotate a vertically provided rotating shaft 3 via a bevel transmission 2.

A rotary arm 4 is attached to the rotary shaft 3, and the rotary arm 4 rotates within a horizontal plane.

A sample support 15 is suspended from the tip of the rotary arm 4, and when the rotary arm 4 rotates, the sample support 15
In response to centrifugal force F1 in the direction of the arrow, the vertical position shown on the left side of the figure changes to the horizontal position shown on the right side of the figure.

Figure 2 shows the vibration actuator, which is the main part of the present invention,
FIG. 3 is an enlarged longitudinal cross-sectional side view showing the swinging mechanism of the sample support.

A shaft 8 is supported at the distal end of the rotary arm 4, and a leaf spring 14 is attached to the shaft 8 via a slip bearing 7. A sample support 15 is suspended from the tip of the plate spring 14.

Furthermore, a vibration actuator 9 that vibrates the sample support 15 using fluid pressure is directly attached to one side of the rotary arm 4. The vibration actuator 9
The actuator housing 10 includes an actuator housing 10 having a cylinder chamber and fixed to the rotary arm 4, and a piston rod 6 supported at both axial ends of the actuator housing 10 via slide bearings 18.

The piston rod 6 of the vibration actuator 9 is supported by the actuator housing 10 so that its central axis coincides with the central axis o-o of the rocking motion of the sample support 15, and this piston rod 6 is It passes through the inside of the shaft 8 and is directly connected to the sample support 15 .

The vibration actuator in this embodiment.

The swinging mechanism of the sample support operates as follows.

That is, when the above-mentioned centrifugal force Fs is applied, the shaft 8 rotates relative to the sliding bearing 7, and the sample support 15 suspended by the leaf spring 14 is swung up horizontally. The tip of the piston rod 6 of the vibration actuator 9 is directly connected to the sample support 15 and supported by a sliding bearing 18 that freely slides in both the rotational and axial directions with respect to the actuator housing 10. Therefore, the piston rod 6 also rotates following the above-mentioned swinging motion.

Here, if the central axis of the piston rod 6 and the central axis O-0 of the swinging movement match, the relationship between the piston rod 6 and the sample support 15 is the same both when swinging up and when swinging down.
By alternately supplying fluid pressure to both chambers divided by the piston rod 6 in the cylinder of the actuator housing 10, the sample support 15 can be stably vibrated.

Next, FIG. 3 shows another embodiment of the present invention, and is a depressed vertical sectional side view of the vibration actuator and the swinging mechanism of the sample support.

In the embodiment shown in FIG. 3, instead of the leaf spring, an outer frame 11, a slide guide 16, and a compression spring 17 are used.
and supports the sample support 15.

In this case as well, it is possible to vibrate the sample support 15 using the vibrating actuator 9 directly attached to the one-rotation arm 4 according to the operating principle described above.

Here, the compression spring 17 is compressed in advance by a force Fo in a state where no centrifugal force is applied.

Furthermore, the compression spring 17 is elastic in the vibration direction as well. By setting the centrifugal force F1 and the force Fo to equal values, the force applied to the sample support 15 and the reaction force of the compression spring 17 are balanced when the centrifugal force F1 is applied, and the centrifugal force F is applied. The force generated between the sample support 15 and the slide guide 16 when
It is possible to reduce the frictional force of the slide guide 16 that is generated in the slide guide 16 and has an adverse effect on vibration to zero.

In each of the above embodiments, the vibration actuator 9 is attached to the highly rigid rotary arm 4, and the piston rod 6 of the vibration actuator 9 is directly connected to the sample support 15, so that the central axis of the piston rod 6 and the sample Since the sample support 15 is vibrated by aligning the center axis of the swing motion of the support 15 with 〇-〇, it is possible to remove looseness and weak parts from the swing mechanism of the sample support 15 before applying the vibration. Vibration performance can be improved, making it possible to conduct stable vibration tests up to high frequency ranges.

〔Effect of the invention〕

According to the present invention described above, the vibration actuator is directly attached to the highly rigid rotating arm.

Further, the central axis of the piston rod of the vibration actuator is arranged to coincide with the central axis of the oscillation aM movement of the sample support, and the piston rod is directly connected to the sample support,
Since the attachment of the vibration actuator can eliminate weak rigid parts and backlash, it is possible to conduct stable vibration tests up to high frequency ranges.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an outline of a dynamic centrifugal force loading experimental device to which the present invention is applied, and FIGS. It is an enlarged longitudinal cross-sectional side view showing an example of a moving mechanism part. DESCRIPTION OF SYMBOLS 1... Electric motor, 2... Bevel transmission, 3... Rotating shaft, 4... Rotating arm, 6... Piston rod, 8...
- Axis, 9... Actuator for vibration, 10... Actuator housing, 14... Temporary spring, 15...
Sample support, 16... Slide guide, 17... Compression spring, ○-O... Central axis of swing movement of the sample support 4, Rotation angle 6, Piston rod 10, Terminal 1, Eta housing link /4 board 1τ
Salt's 6 Piston rod a Su ＼ bearing 8 @ So I finished talking to Kaba Nayuta L・-A 2 ÷ Work 1 − Ta I ＼ Ushin 7 11 Outside 11j + 1714

Claims (1)

[Claims] 1. A rotary arm is provided on a vertically mounted rotary shaft so as to be rotatable in a horizontal plane, and a sample support is suspended from the tip of the rotary arm so as to be swingable by centrifugal force. , in a dynamic centrifugal force loading experimental device equipped with an excitation actuator that vibrates the sample support using fluid pressure, the excitation actuator is directly attached to the rotary arm, and the piston of the excitation actuator is attached directly to the rotary arm. The central axis of the rod is aligned with the central axis of the swinging motion of the sample holder,
A dynamic centrifugal force loading experimental device characterized in that the piston rod is directly connected to a sample support.