JP2000084486A - Shaking machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaking machine capable of faithfully reproducing desired vibration and adaptable even to a minute model. SOLUTION: The piston rods 14A, 15A of the hydraulic cylinders 14, 15 arranged to a base plate 10 are fixed to the lower part of a vibration plate 13 having an object to be vibrated arranged thereto and reduced wall parts 14a, 15a having thicknesses less than the diameters 14A, 14B of the piston rods are formed to the intermediate parts of the piston rods 14A, 15A and the projection and retreat of the piston rods 14A, 15A are repeated by supplying oil pressure to the hydraulic cylinders 14, 15 through hydraulic servo valves to transmit vibration to a vibration plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration generating device for reproducing vibration such as an earthquake.

[0002]

The vibration exciter is designed to provide a user with a simulated experience of an earthquake by reproducing the vibration of an earthquake in an earthquake experience device for disaster prevention guidance.
It is used in games machines, movie theaters, theme park attractions, and the like to reproduce the vibrations of earthquakes and vehicles to increase the sense of realism.

FIG. 5 is a schematic diagram showing the configuration of a conventional vibration generating device used for an earthquake experience device.

In this conventional vibration generating device, hydraulic cylinders 2 and 3 are mounted on a base 1 and piston rods 2a and 3
The vibrating table 4 is supported on the hydraulic cylinders 2 and 3 by connecting the tips of the piston rods 2a and 3a to the bottom surfaces thereof.

[0005] A hydraulic servo valve SV is connected to the hydraulic cylinders 2 and 3.
However, the hydraulic pressure is alternately supplied to the hydraulic chambers on both sides of the respective pistons 2b, 3b of the hydraulic cylinders 2, 3 by a signal from a drive circuit (not shown), so that the piston rods 2a, 3a
Is moved up and down by a short stroke, so that a longitudinal vibration is applied to the vibration table 4.

Further, the vibrating device includes a vibration table 4
Is connected to a hydraulic cylinder (not shown) in which a piston rod is installed horizontally, so that the vibration table 4 is similarly subjected to lateral vibration, and a composite of longitudinal vibration and lateral vibration is provided. As a result, the vibration of the earthquake is faithfully reproduced.

In the vibrating device, the vibration table 4 and the piston rods 2a, 3a of the hydraulic cylinders 2, 3 are pin-mounted on a bracket 4A attached to the bottom of the vibration table 4, as shown in FIG. The piston rods 2a and 3a are rotatably connected by the shaft 4B, thereby allowing the vibration table 4 to swing,
It has made it possible to faithfully reproduce earthquakes.

Here, in addition to the case where a full-scale model is put on the vibration table 4 as in the above-described vibration generator and a vibration experiment is performed, the full-scale model is too large-scale to be implemented. In recent years, there has been an increasing demand for performing various kinds of vibration experiments with a small model obtained by reducing the actual thing to a fraction.

However, when manufacturing a vibration device for a test using such a small model, if a full-size vibration device is to be manufactured as it is, the vibration table of FIG. Piston rods 2a, 3a
A slight backlash is generated at the connecting portion between the pin shaft 4B and the pin hole of the bracket 4A due to a gap formed between the pin shaft 4B and the pin hole of the bracket 4A. As a result, the vibration whose amplitude is reduced is absorbed by the rattling of the connection between the vibration table and the piston rod of the hydraulic cylinder in the micro model, and the problem that the desired vibration cannot be reproduced occurs. come.

[0010] For this reason, there is a strong demand for the development of a vibration exciter capable of faithfully reproducing a desired vibration even in a small model.

In particular, as shown in FIG. 7, the weight of the ground model to be tested is increased to a required magnification by the centrifugal force of the centrifugal loading device 5 like a vibration device 6 attached to the centrifugal loading device 5. Then, a seismic wave is applied to the earthquake model reduced by a similar ratio of 1 / magnification, and an exciter that performs a ground vibration test of civil engineering in a centrifugal field can be attached to a centrifugal loading device and has a desired shape. There is a strong demand for the development of a micro model vibration generator capable of faithfully reproducing vibration.

The present invention has been made in order to solve the above-described problems in manufacturing the vibration generating device. That is, an object of the present invention is to provide a vibration generating device that can faithfully reproduce a desired vibration and can be applied to a minute model.

[0013]

According to a first aspect of the present invention, a piston rod of a hydraulic cylinder installed on a base is connected to a lower portion of a diaphragm on which an object to be vibrated is installed. In a vibrating device in which hydraulic pressure is supplied to a hydraulic cylinder via a hydraulic servo valve to repeatedly vibrate a diaphragm by repeatedly projecting and retracting a piston rod, the distal end of the piston rod of the hydraulic cylinder is It is characterized in that it is fixed to a lower part and a reduced thickness portion having a thickness smaller than the diameter of the piston rod is formed in an intermediate portion of the piston rod.

In the vibration generating device according to the first aspect of the present invention, the supply of hydraulic pressure to the hydraulic cylinder by the operation of the hydraulic servo valve causes the piston rod to repeatedly protrude and retreat in a short stroke, whereby vibration is applied to the diaphragm. However, at this time, since the piston rod is fixedly attached to the diaphragm, for example, as in a case where the piston rod and the diaphragm are relatively movably connected via a connection shaft or the like. Thus, the vibration of the piston rod is reliably transmitted to the diaphragm without being absorbed at the connection with the diaphragm.

[0015] Even when the relative positional relationship between the piston rod and the diaphragm changes due to the vibration of the diaphragm, and the piston rod is fixed to the diaphragm, a bending force acts on the piston rod. In the thinned portion formed in the middle part of the piston rod, the piston rod bends and the distortion due to the change in the relative positional relationship between the piston rod and the diaphragm is absorbed, so that the vibration of the diaphragm is allowed, The vibration as set is transmitted to the diaphragm.

As described above, according to the first aspect,
The piston rod is fixed to the diaphragm by forming a thinned part on the piston rod and absorbing the strain caused by the change in the relative positional relationship when the piston rod and the diaphragm vibrate at the thinned part. As a result, the vibration generated by the hydraulic cylinder can be reliably transmitted without being absorbed at the connection between the piston rod and the diaphragm.

Therefore, if the present invention is applied to a vibrating device for a micro model that vibrates a model whose actual size is reduced, it is possible to reliably transmit a fine vibration whose actual amplitude is reduced to the diaphragm. Become.

According to a second aspect of the present invention, in order to achieve the above object, in addition to the configuration of the first aspect, the vibration-reducing device is characterized in that the thinned portion is formed at a plurality of positions of a piston rod. I have.

According to the vibration generating device of the second aspect, in addition to the effect of the first aspect, distortion caused by a change in the relative positional relationship between the piston rod and the diaphragm during vibration is reduced.
Since the piston rod is absorbed by bending at the plurality of thinned portions formed at the intermediate portion of the piston rod, vibration of the diaphragm is allowed in a wider range,
Transmission of the vibration as set to the diaphragm can be performed more reliably. This further widens the range of application of the micro model to the vibration generating device.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view showing an example of a vibration generating device according to an embodiment of the present invention with a diaphragm removed, and FIG. 2 is a side view showing the vibration generating device of the same example. 1 and 2, air cushions 12 are attached to four corners on a substrate 10, respectively.

Then, the diaphragm 13 serves as the air cushion 1.
2 is placed in parallel with the substrate 10 and the diaphragm 1
The upper end of each air cushion 12 is connected to four corners of the lower surface of the lower surface 3, so that the upper surface of the air cushion 12 is supported so as to be able to vibrate vertically and vertically and horizontally.

A compressor (not shown) is connected to the air cushion 12, and is installed to help support the weight of the vibrating object on the diaphragm 13 when a hydraulic cylinder described later is in an inoperative state. ing.

A pair of hydraulic cylinders 14 and 15 are attached to the left and right side edges of the substrate 10 in FIG. As shown in FIG. 3, the hydraulic cylinders 14 and 15 have their respective piston rods 14A and 15A directed obliquely upward and inward to each other so as to form an eight-shape. It is fixed to the lower surface of the diaphragm 13 via 16 and 17.

The hydraulic chambers on both sides of the pistons 14B and 15B of the hydraulic cylinders 14 and 15 are connected to hydraulic pumps (not shown) via hydraulic servo valves.

FIG. 4 is a view showing the shape of the piston rod 14A of the hydraulic cylinder 14. In FIG. 4, the hydraulic cylinder 14A of the metal piston rod 14A is shown.
In the portion protruding from the main body, a thinned portion 14a is formed in two places, and a cylindrical shaft is cut from both sides and formed into a plate shape.

The piston rod 15A of the hydraulic cylinder 15
The shape of the piston rod 14A is also the same as that of the piston rod 14A. In the part of the piston rod 15A protruding from the main body of the hydraulic cylinder 15, two cylindrical shafts are cut from both sides to form a plate-shaped reduction rod. A meat portion 15a is formed.

In FIG. 1, the base end of the support shaft 18 is swingably connected to a corner on the substrate 10 at the lower left of the drawing in a plane parallel to the plane including the piston rods 14A and 15A. Further, the base end of the support shaft 19 is swingably connected to a corner on the substrate 10 at the upper right of the drawing in a plane parallel to a plane including the piston rods 14A and 15A.

As shown in FIG. 2, the distal ends of the support shafts 18 and 19 are slidably fitted into cylinders 18A and 19A attached to the side of the vibration plate 13, respectively. On the upper surface of the diaphragm 13,
A housing 20 on which an object to be subjected to a vibration experiment such as a miniature building built on the soil portion is fixed.

In the vibrating device, a hydraulic servo valve (not shown) is operated by a signal from a drive circuit, and hydraulic pressure is alternately supplied from a hydraulic pump to hydraulic chambers on both sides of pistons 14B and 15B of hydraulic cylinders 14 and 15, respectively. As supplied, the piston rods 14A and 15A repeatedly protrude and retreat in a short stroke.

At this time, when the operation of the hydraulic cylinders 14 and 15 is in the in-phase state in which the piston rods 14A and 15A protrude, the diaphragm 1 is perpendicular to the substrate 10.
When the piston 3 is lifted and the operation of the hydraulic cylinders 14 and 15 is in an out-of-phase state in which one piston rod is protruded and the other piston rod is retracted, the diaphragm 13 is located on the side of the hydraulic cylinder 14 or 15 for retracting the piston rod. Is moved horizontally with respect to the substrate 10.

When the operation of the hydraulic cylinders 14 and 15 is in an out-of-phase state, the support shafts 18 and 19 connected to both sides of the diaphragm 13 are slightly rotated with respect to the substrate 10, respectively, and the tip end is a cylinder 18A. And 1
Since the diaphragm 13 is slightly slid with respect to 9A to support the diaphragm 13, the diaphragm 13 always keeps a horizontal state without tilting.

In this vibrating device, the distal ends of the piston rods 14A and 15A are fixed to the lower surface of the diaphragm 13 by connecting portions 16 and 17, respectively, and their mounting angles θ and θ ′ (see FIG. 3). ) Does not change, when the hydraulic cylinders 14 and 15 operate in the same phase and the diaphragm 13 moves up and down, and when the hydraulic cylinders 14 and 15 operate in the different phases and the diaphragm 13 moves horizontally, The relative positional relationship between the piston rods 14A and 15A and the diaphragm 13 changes, and a bending force acts on the piston rods 14A and 15A.

At this time, the piston rods 14A and 14A
5A is slightly deflected at each of the thinned portions 14a and 15a, so that the piston rods 14A and 1A
Distortion due to a change in the relative positional relationship between the diaphragm 5A and the diaphragm 13 is absorbed, and vertical and horizontal movements of the diaphragm 13 are allowed.

As described above, the vibration generating device transmits the vibrations of the piston rods 14A and 15A to the diaphragm 13 with the distal ends of the piston rods 14A and 15A fixed to the lower surface of the diaphragm 13. Is transmitted to the diaphragm 13 as it is without being absorbed at the connection between the piston rods 14A and 15A and the diaphragm 13.

The piston rods 14A and 15A
Each of the thinned portions may be formed at one place, but by forming two places as in the above example, the relative positional relationship between the piston rods 14A and 15A and the diaphragm 13 can be changed. The vibration plate 1 can absorb more vibration and reliably set the vibration set for the experiment.
3 can be transmitted.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an embodiment of the present invention.

FIG. 2 is a side view of the same example.

FIG. 3 is a side view showing a mounted state of the hydraulic cylinder in the same example.

FIG. 4 is a perspective view showing a shape of a piston rod in the same example.

FIG. 5 is a schematic side view showing a conventional example.

FIG. 6 is an explanatory view showing a conventional method of connecting a vibration table and a piston rod.

FIG. 7 is a perspective view showing a conventional centrifugal loading device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Substrate (base) 13 ... Vibration plate 14, 15 ... Hydraulic cylinder 14A, 15A ... Piston rod 14a, 15a ... Thinning part

Claims (2)

[Claims] 1. A piston rod of a hydraulic cylinder installed on a base is connected to a lower portion of a diaphragm on which an object to be vibrated is installed, and hydraulic pressure is supplied to the hydraulic cylinder via a hydraulic servo valve so that the piston rod is In a vibrating device that vibrates the diaphragm by repeating protruding and retreating, a distal end of a piston rod of the hydraulic cylinder is fixed to a lower portion of the diaphragm, and the piston rod is disposed at an intermediate portion of the piston rod. A vibration exciter characterized in that a thinned portion having a thickness smaller than a diameter is formed. 2. The vibration oscillating device according to claim 1, wherein the thinned portions are formed at a plurality of positions on the piston rod.