JPH01240837A - Centrifugal force loading tester - Google Patents

Abstract

PURPOSE:To perform a vibration resistance test to a large body being tested using large centrifugal force, by throwing up a throw-up wt. by the rotation of a rotary arm and shaking the body tested on a vibration table in a centripetal direction to bring the same to a horizontal posture and vibrating the body being tested. CONSTITUTION:When an electromotor 1 rotates a rotary shaft 3 provided vertically through a bevel gearbox 2, a rotary arm 4 is rotated within a horizontal plane. The throw-up wt. suspended from the leading end of the rotary arm 4 receives centrifugal force F1 in the direction shown by an arrow when the rotary arm 4 is rotated to become a horizontal posture from the vertical posture. The body 6 tested arranged on the vibration table 7, which is fitted to the shaft 8 vibrated along with the throw-up wt. 5 on the side opposite to the throw-up wt. 5 thereof through a slide moving mechanism 23, becomes a horizontal posture along with the vibration table 7 when the throw- up wt. 5 is thrown up to receive the acceleration F2 due to the centrifugal force. The vibration of the vibration table 7 is performed by the hydraulic actuator 9 mounted on the shaft 8.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a centrifugal force loading experimental device for testing by simultaneously applying centrifugal acceleration and vibration acceleration to scale models of the ground, structures, etc. The present invention relates to an apparatus suitable for performing vibration resistance tests on comparatively large shaped specimens.

[Conventional technology]

When conducting an experiment by creating a scale model 1. If the test is conducted in a normal gravity field, it is difficult to reproduce the stress caused by the weight of the specimen. The centrifugal force loading experiment device basically attaches a scale model of the ground or structure under test to the tip of a single rotating arm, and rotates the rotating arm at high speed in a horizontal plane to create a large scale model on the test piece. Apply centrifugal acceleration to 1/H
This creates a state equivalent to applying N times the gravitational acceleration to the scale model. As a technique related to this type of device, for example, Japanese Utility Model Publication No. 46439/1984 can be cited.

[Problem to be solved by the invention]

In the above-mentioned centrifugal force mounting experimental apparatus, when an excitation mechanism is installed to apply centrifugal acceleration and vibration acceleration to the specimen at the same time and a vibration resistance test is to be performed on the specimen, the As shown in the figure, a sample support 15 is suspended by a pair of leaf springs 14 from a shaft 8 provided at the tip of a rotary arm 4 that rotates in a horizontal plane.

Generally, a mechanism is considered in which a vibration actuator 9 is attached to a shaft 8 that swings together with the sample support 15, a specimen is placed in the sample support 15, and the sample support 15 is vibrated. The shaft 8 has a housing 10° rotating plate 11. Slip board 1
The sample support 15 is supported by a thrust bearing consisting of 2 and 2 spherical bearings 13, and in FIG. It shows.

In this mechanism, the cross-sectional area of the leaf spring 14 must be small in order to excite vibrations. However, when testing a relatively large specimen, the centrifugal force F2 increases,
On the other hand, since the tensile stress generated in the leaf spring 14 in response to the centrifugal force F2 must be smaller than the allowable tensile stress of the leaf spring 14, it is necessary to increase the cross-sectional area of the leaf spring 14. In this way, when excitation is performed by the actuator in a state where a large centrifugal force is applied, the leaf spring 14 is subjected to a large centrifugal force.

Since the contradictory functions of having low rigidity and being able to withstand large tensile force are required, the specifications for centrifugal force mounting and dynamic vibration are limited due to the limits of the rigidity and tensile strength of the leaf spring.

Furthermore, as shown in FIG.
Because it must have enough rigidity to withstand vibration, there are restrictions on its shape and size. It was necessary to create a container as the sample support 15 each time, which can be hung and has sufficient rigidity to withstand vibration.

The purpose of the present invention is to eliminate the above-mentioned experimental limitations,
To provide a centrifugal force mounting experimental device capable of easily attaching a relatively large specimen or specimen container having an arbitrary shape and excitation while applying large acceleration due to centrifugal force. be.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a rotating arm that is attached to a vertically provided rotating shaft and rotates in a horizontal plane, and a swing-up arm that is suspended from the tip of the rotating arm and swings by the centrifugal force caused by the rotation. The swing-up weight includes a weight, a vibration table attached via a sliding mechanism to a shaft that swings together with the swing-up weight, and an actuator that is attached to the swinging shaft and vibrates the vibration table. and the vibration table are located on opposite sides of the vibration center, and the center of gravity of the entire rocking part is closer to the lifting weight than the vibration center, and the specimen mounting surface of the vibration table is It is constructed so that it lies on a vertical line passing through it.

[Effect]

In the centrifugal force mounting experimental device of the present invention, the lifting weight is swung up by the centrifugal force received by the rotation of the rotary arm to take a horizontal position, and the specimen placed on the vibration table is swung in the centripetal direction of the rotary arm. By placing the specimen in a horizontal position, the centrifugal force exerted by the specimen always acts on the vibration table as a compressive load in the vertical direction, and while this load is stably supported by the vibration table and sliding mechanism, the oscillating shaft A vibrating actuator attached above moves the vibrating table all the way to vibrate the specimen. Therefore, unlike the general vibration mechanism shown in Fig. 5, the specifications for centrifugal force mounting and dynamic vibration are not limited due to the limits of rigidity and tensile strength of the leaf spring, and the vibration table Centrifugal acceleration and vibrational acceleration can be simultaneously applied in a stable state to the specimen placed on top of the specimen, and the specimen can be placed directly on the vibration table or placed in a container, so the shape of the specimen can be easily controlled. It can have any shape without any restrictions on size or size. It is possible to perform vibration resistance tests on relatively large specimens under high centrifugal force.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a schematic front view of an embodiment of the centrifugal force mounting experimental apparatus according to the present invention.

The electric motor 1 rotates a vertically provided rotating shaft 3 via a bevel transmission 2. The rotating arm 4 attached to the rotating shaft 3 rotates within a horizontal plane.

The lifting weight 5 is suspended from the tip of the rotating arm 4, and when the rotating arm 4 rotates, it receives centrifugal force F1 in the direction of the arrow, and changes from the vertical position shown on the left side of the figure to the horizontal position shown on the right side of the figure. It becomes a posture. The vibration table 7 is attached to the opposite side of the shaft 8, which swings together with the lifting weight 5, via a vertical movement mechanism 23. When the swing-up weight 5 is swung up, the specimen 6 placed on the vibration table 7 assumes the horizontal position shown on the right side of the figure together with the vibration table 7, and is subjected to acceleration F2 due to centrifugal force.

Vibration of the vibration table 7 is performed by a hydraulic actuator 9 attached to a shaft 8.

FIG. 2 is an explanatory diagram in which a hydraulic system diagram is added to a cross-sectional view of the hydraulic actuator 9. In the figure, the inside of the part surrounded by the two-dot chain line shows the components installed on the rotary arm 4''. It is a piping diagram.

The hydraulic power source device 17 is operated while the rotary arm 4 is stopped, and hydraulic oil is accumulated in the accumulator 16 via the connection joint 18. When a control current is applied to the servo valve 20 while the connecting joint 18 is disconnected and the rotary arm 4 is rotating, the hydraulic oil accumulated in the accumulator 16 is released and flows into the cylinder 22 of the hydraulic actuator 9.

The hydraulic oil on the opposite side of the cylinder 22 is then returned to the receiver 19. The piston rod 21 is connected to the vibration table 7, and by reciprocating the piston rod 21 by changing the oil flow direction, the vibration table 7
Excite.

FIG. 3 is a detailed view of the swinging part and dynamic vibration mechanism installed at the tip of the rotary arm 4, and is a view in the direction of arrow A in FIG.
The figure is a sectional view taken along line B-13 in FIG.

In FIG. 3, when the rotary arm 4 rotates in a horizontal plane, a centrifugal force Fl acts on the swinging portion at the tip of the rotary arm 4. rotating arm 4
At the tip of the shaft 8, there is a thrust bearing consisting of a housing 10, a rotating plate 11, a sliding plate 12, and two spherical bearings 13.
It is supported by

A lifting weight S and a hydraulic actuator 9 are attached to this shaft 8. The tip of the piston rod 21 of the hydraulic actuator 9 is connected to a vibration table 7, and the vibration table 7 is supported on a shaft 8 via a sliding movement mechanism 23 so that the vibration table 7 can be moved in the direction of vibration by the hydraulic actuator 9. There is.

A specimen 6 or a specimen container is mounted on this vibration table 7.

Here, as shown in FIG. 4, the center of gravity G of the part (including the specimen 6) that is attached to the above-mentioned shaft 8 and swings together with the shaft 8 is on the side of the swing-up weight 5 with respect to the swing center 0. If the center of gravity [G] is located on a line drawn perpendicularly from the center of the specimen 6 to the specimen mounting surface of the vibration table 7, then when the centrifugal force F1 mentioned above acts,
The lifting weight 5 is swung to a horizontal position as shown in Fig. 4, and at the same time, the specimen 6 and the vibration table 7 are
By swinging to the horizontal position on the opposite side, a large acceleration F2 due to centrifugal force in a constant direction (direction perpendicular to the vibration table 7) can always be applied to the specimen 6.

With the above mechanism, it is possible to vibrate the specimen 6 while applying a large acceleration due to centrifugal force.

〔Effect of the invention〕

According to the present invention, an actuator can vibrate a relatively large specimen having an arbitrary shape while applying a large acceleration due to centrifugal force.

Therefore, there is an effect that a vibration resistance test can be easily performed on a scale model of the ground, a structure, etc. in a state where the stress due to its own weight is reproduced.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of an embodiment of the centrifugal force loading experimental device according to the present invention, Fig. 2 is an explanatory diagram with a hydraulic system diagram added to a sectional view of the vibration actuator, and Fig. A in the diagram
4 is a sectional view taken along the line BB in FIG. 3, and FIG. 5 is a sectional view of a vibration mechanism according to the prior art. 6 3...rotating shaft, 4... rotating arm, 5... ... Weight for swinging up, 6 ... Specimen, 7 ... Vibration table, 8 ...
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Claims (1)

[Claims] 1. A rotating arm that is attached to a vertically installed rotating shaft and rotates in a horizontal plane, a lifting weight that is suspended from the tip of the rotating arm and swings by the centrifugal force caused by the rotation, and the above-mentioned lifting weight. A vibration table is attached to a swinging shaft via a sliding mechanism, and an actuator is mounted to the swinging shaft and vibrates the vibration table, and the swinging weight and the vibration table swing. They are located on opposite sides with respect to the center, and are configured so that the center of gravity of the entire swinging part is on the swinging weight side of the swinging center and on a vertical line passing through the specimen installation surface of the vibration table. Centrifugal force loading experimental device.