JP2012181297A - Quake generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quake generator which is capable of reproducing long-period earthquake motion without being increased in scale.SOLUTION: A quake generator K1 includes: a linear actuator 3 having a movable part M capable of reciprocating in a linear direction; a spring element 5 which expands and contracts in accordance with reciprocation of the movable part M; a holding member 2 holding one of the linear actuator 3 and the spring element 5; and a movable floor 4 which can be moved at least in the same direction as a reciprocating direction of the movable part M relatively to the holding member 2. The linear actuator 3 and the spring element 5 are connected in series between the holding member 2 and the movable floor 4.

Description

  The present invention relates to a seismic device.

  Conventionally, as a seismic device, for example, when mounted on a vehicle, a cross member fixed to a vehicle body, an X-axis direction moving frame movable in the X-axis direction with respect to the cross member, And a hydraulic cylinder interposed between the cross member and the X-axis direction moving frame, and driving the hydraulic cylinder drives the X-axis direction moving frame with respect to the vehicle body in the X-axis direction. And by making it vibrate, the earthquake motion is reproduced.

  In this seismic device, a Y-axis direction moving frame that can move in the Y-axis direction with respect to the X-axis direction moving frame, and the Y-axis direction in order to reproduce the earthquake motion in both the Y-axis direction and the Z-axis direction. A Z-axis direction moving frame that is movable in the Z-axis direction with respect to the moving frame is provided, and the Y-axis direction moving frame is disposed between the X-axis direction moving frame and the Y-axis direction moving frame with respect to the X-axis direction moving frame. A hydraulic cylinder that intervenes a hydraulic cylinder that drives in the Y-axis direction and that drives the Z-axis moving frame in the Z-axis direction with respect to the Y-axis moving frame between the Y-axis moving frame and the Z-axis moving frame. A cylinder is interposed (for example, see Patent Document 1).

JP 2000-259073 A

  In conventional seismic devices, there is no problem in that each frame can be vibrated with the acceleration that is generally generated by a large earthquake by expanding and contracting the hydraulic cylinder, but there is a problem when trying to reproduce long-period ground motion Occurs.

  Here, long-period ground motion vibrates the high-rise building at a frequency close to the natural frequency of the high-rise building where earthquake countermeasures have been taken. It is known to grow very large.

  In order to experience such a long-period ground motion with a conventional shaking device, each frame in the shaking device must be vibrated with a large amplitude. Specifically, since a large amplitude is reproduced by expansion and contraction of a linear actuator such as a hydraulic cylinder, there is a problem that the linear actuator becomes long and the seismic device becomes large.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a seismic device capable of reproducing long-period ground motion while avoiding an increase in size of the device. It is.

  In order to achieve the above object, a seismic device in the problem solving means of the present invention includes a linear actuator having a movable part that can reciprocate in a linear direction, a spring element that expands and contracts by reciprocating movement of the movable part, and the linear A holding member that holds one of an actuator and a spring element; and a movable floor that can move relative to the holding member in the same direction as at least the reciprocating direction of the movable portion. The linear actuator and the spring element are connected in series and interposed between the floor and the floor.

  In this seismic device, when the movable portion of the linear actuator is reciprocated at a frequency that matches the natural frequency of the system composed of the movable floor and the spring element, the spring element expands and contracts at the natural frequency. Thereby, a movable floor resonates and exhibits a reciprocating motion. As a result, the amplitude of the movable part of the linear actuator can be amplified and transmitted to the movable floor, and the amplitude of the movable floor can be made larger than the stroke length of the linear actuator.

  According to the seismic device of the present invention, it is possible to amplify the amplitude of the movable portion of the linear actuator and vibrate the movable floor with a large amplitude. Therefore, use a linear actuator having a stroke length shorter than the amplitude of the movable floor. Can do. As a result, it is possible to reproduce long-period ground motion while avoiding an increase in the size of the apparatus.

It is a side view of the seismic device in one embodiment. It is a gain characteristic figure of the amplitude of a movable floor to the amplitude of a movable part of a linear actuator. It is a bird's-eye view of the seismic device in other embodiments. It is a bird's-eye view of the seismic device in another embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, the seismic device K <b> 1 in one embodiment has a holding member 2, a linear actuator 3, and a relative movement relative to the holding member 2 in at least the same direction as the expansion / contraction direction of the linear actuator 3. A movable floor 4 and a spring element 5 are provided, and the linear actuator 3 and the spring element 5 are connected in series between the movable floor 4 and the holding member 2. It is.

  In this seismic device K1, the earthquake can be reproduced by vibrating the movable floor 4 with the linear actuator 3. For example, the subject can experience an earthquake by placing the subject on the movable floor 4 and applying the vibration. It is also possible to conduct earthquake damage experiments on structures, buildings, etc. by placing structures, buildings, etc. on the movable floor 4 and vibrating the movable floor 4.

  Hereinafter, each part of seismic device K1 of one embodiment is explained in detail. In this embodiment, the holding member 2 includes a traveling floor 2a on which the movable floor 4 travels and a holding portion 2b that stands up from the traveling floor 2a and holds the linear actuator 3.

  In this embodiment, the linear actuator 3 is a hydraulic cylinder, a cylinder 3a held by the holding portion 2b of the holding member 2, a piston 3b slidably inserted into the cylinder 3a, and a cylinder 3a. The hydraulic oil is supplied to and discharged from the piston rod 3c, which is movably inserted into the piston 3b and connected to the piston 3b, and the rod side chamber R1 and the piston side chamber R2 partitioned by the piston 3b in the cylinder 3a. On the other hand, a hydraulic pump 3d that relatively moves the piston 3b in the axial direction is provided. In the linear actuator 3, the hydraulic oil is supplied to the rod side chamber R1 by the hydraulic pump 3d and is discharged from the piston side chamber R2, so that the piston 3b and the piston rod 3c connected thereto are discharged. 1 can be moved in the right direction in FIG. 1, and the hydraulic oil is discharged from the rod side chamber R1, and the hydraulic oil is supplied to the piston side chamber R2, so that the piston 3b and the piston rod 3c connected thereto are shown in FIG. It can be moved to the left. That is, in this embodiment, the movable part M in the linear actuator 3 is constituted by the piston 3b and the piston rod 3c connected thereto, and the movable part M can be reciprocated in the linear direction.

  The linear actuator 3 may be a pneumatic cylinder that uses a fluid other than the working oil, for example, a gas, as a working fluid. In addition to such a cylinder type actuator, a linear motor or a rotary type may be used. It may be a linear actuator composed of a motor and a feed screw mechanism. And if it is a linear motor, it is comprised with a magnet and an electromagnet, and what is necessary is just to make any one into a movable part. Even if it exists in the linear actuator which consists of a rotary motor and a feed screw mechanism, a motor or a feed screw mechanism A member that exhibits a linear motion in the above may be used as a movable portion.

  On the other hand, the movable floor 4 includes a floor main body 4a and a plurality of traveling wheels 4b provided in the lower portion of the floor main body 4a, and the traveling floor 2a of the holding member 2 described above is arranged in the left-right direction in FIG. The vehicle can travel in a direction that matches the expansion / contraction direction. That is, the movable floor 4 can move in a direction that matches the expansion / contraction direction of the linear actuator 3 with respect to the holding member 2.

  In this embodiment, the movable floor 4 travels on the traveling floor 2a of the holding member 2. However, the holding member 2 includes a rail along the expansion / contraction direction of the linear actuator 3 instead of the traveling floor. The movable floor 4 may run on the rail, or a linear guide composed of a guide rail and a slider is provided between the holding member 2 and the movable floor 4 so that the movable floor 4 is connected to the linear actuator 3. You may restrict | limit moving to directions other than the direction corresponding to an expansion-contraction direction. In particular, when the relative movement direction of the movable floor 4 with respect to the holding member 2 is not limited, the traveling wheel 4b may rotate around the axis with respect to the floor body 4a about the vertical direction in the figure. Alternatively, a ball wheel having a spherical wheel may be used as the traveling wheel 4b, or a large number of balls may be arranged on the lower surface of the floor body 4a of the movable floor 4 or the upper surface of the traveling floor 2a of the holding member 2 to move the movable floor 4b. The relative movement may be smoothed. Further, the traveling wheel 4b may be eliminated, and a number of rollers may be disposed on the traveling floor 2a, and the movable floor 4 may be caused to travel on the roller. The traveling wheel 4b may be eliminated and the traveling floor 2a and the movable floor may be disposed. 4 may be formed with a low friction material amount so that these contact surfaces are smoothed, and the movable floor 4 may be slid on the traveling floor 2a. Since the holding member 2 only needs to hold the linear actuator 3, the traveling floor 2a is not essential. However, as described above, the provision of the traveling floor 2a provides an environment suitable for traveling on the movable floor 4. Therefore, smooth movement of the movable floor 4 can be realized.

  In this case, the spring element 5 is a coil spring, and one end is connected to the movable floor 4 and the other end is connected to the piston rod 3 c of the linear actuator 3. That is, the spring element 5 and the linear actuator 3 are connected in series and are interposed between the holding member 2 and the movable floor 4. The spring element 5 is not limited to a coil spring, and may be any element that expands and contracts by receiving an external force and generates a reaction force that opposes the external force along with the expansion and contraction.

  In the seismic device K1 configured in this way, when the piston 3b and the piston rod 3c, which are the movable part M of the linear actuator 3, are reciprocated, the spring element 5 expands and contracts. Since the vibration of the movable part M is transmitted to the movable floor 4 via the spring element 5, the seismic device K <b> 1 can move the movable floor 4 relative to the holding member 2.

  If the mass of the spring element 5 is ignored, the natural frequency determined by the mass of the movable floor 4 and the spring constant of the spring element 5, that is, at a frequency that matches the natural frequency in the system of the movable floor 4 and the spring element 5. When the movable part M of the linear actuator 3 is reciprocated, the spring element 5 expands and contracts at the natural frequency and the movable floor 4 resonates, so that the amplitude of the movable part M of the linear actuator 3 is amplified and transmitted to the movable floor 4. Will be. When the mass of the movable floor 4 is 1000 kg, the natural frequency is 0.2 Hz, and the vibration damping ratio is 5%, the gain characteristic of the amplitude of the movable floor 4 with respect to the amplitude of the movable portion M of the linear actuator 3 is shown in FIG. 2, when the movable portion M of the linear actuator 3 is expanded and contracted at the natural frequency, the amplitude of the movable floor 4 with respect to the amplitude of the movable portion M is about 10 times (solid line in FIG. 2). ). Further, when the attenuation ratio is 2% under the same conditions, the same magnification is about 25 times (dashed line in FIG. 2). Actually, when the movable floor 4 is vibrated by the linear actuator 3, the natural frequency including the subject and the mass of the object loaded on the movable floor 4 is obtained, and the linear actuator 3 is driven. .

  As described above, in the seismic device K1 of the present invention, the movable floor 4 can be vibrated with a large amplitude by amplifying the amplitude of the movable portion M of the linear actuator 3. Thereby, in the seismic device K1, the linear actuator 3 which has a stroke length shorter than the amplitude of the movable floor 4 can be utilized. Therefore, according to the seismic device 1 of the present invention, long-period ground motion can be reproduced while avoiding an increase in the size of the device.

  Moreover, when experiencing long-period ground motion with this seismic device K1, the characteristics of various buildings can be easily reproduced by changing the spring constant of the spring element 5.

  Although the linear actuator 3 is connected to the holding member 2, the spring element 5 is connected to the holding member 2 so that the linear actuator 3 is interposed between the movable floor 4 and the spring element 5. Good. Specifically, one end of the spring element 5 is connected to the holding portion 2b of the holding member 2, the other end of the spring element 5 is connected to one of the cylinder 3a and the movable portion M of the linear actuator 3, and the cylinder of the linear actuator 3 is connected. You may make it connect the other of 3a and the movable part M to the movable floor 4. Also in this case, when the movable portion M of the linear actuator 3 is reciprocated, the movable floor 4 moves relative to the holding member 2 and the spring element 5 expands and contracts due to inertial force. An effect can be obtained.

  As described above, the moving direction of the movable floor 4 is not limited, and the spring element 5 is allowed to bend in the direction penetrating the paper surface in FIG. 1. Is also allowed. However, in this state, the degree of freedom is low. Therefore, in order to increase the degree of freedom, the holding member 2 reciprocates the movable portion of the linear actuator 3 on the second holding member 6 as in the seismic device K2 of another embodiment shown in FIG. A movable portion that reciprocally moves in a direction different from the reciprocating direction of the movable portion of the linear actuator 3 between the holding member 2 and the second holding member 6. The second linear actuator 7 and the second spring element 8 may be interposed in series.

  The second holding member 6 includes a traveling floor 6a on which the holding member 2 travels and a holding portion 6b that stands up from the traveling floor 6a and holds the second linear actuator 7. In this case, the holding member 2 is provided with a plurality of traveling wheels 2c below the traveling floor 2a, and can smoothly travel on the traveling floor 6a of the second holding member 6.

  Although not shown in detail, the second linear actuator 7 includes a movable portion that reciprocates in the linear direction, like the linear actuator 3, and can use various linear actuators. 8 is the same as the spring element 5.

  The relationship between the second holding member 6 and the holding member 2 in this other embodiment corresponds to the relationship between the holding member 2 and the movable floor 4 in the embodiment shown in FIG. Accordingly, the second linear actuator 7 having a movable portion that reciprocates in a direction different from the reciprocating direction of the movable portion of the linear actuator 3 and the second spring element 8 are used to hold the holding member 2 with respect to the second holding member 6. Since the holding member 2 is vibrated in a direction different from the reciprocating direction of the movable portion of the linear actuator 3, the amplitude of the holding member 2 is also amplified by the second linear actuator 7. The amplitude exceeds the stroke length. In FIG. 3, since the drawing is complicated, illustration of the traveling wheels 4 b provided in the lower part of the floor body 4 a of the movable floor 4 is omitted. 3 indicates the reciprocating direction of the movable portion of the actuator 3, that is, the reciprocating direction, and the broken arrow indicates the reciprocating motion of the movable portion (not shown) of the second actuator 7. Shows direction.

  The seismic device K2 in the other embodiment has the same configuration as that of the embodiment, that is, the holding member 2, the linear actuator 3, the movable floor 4, and the spring element 5 are provided. On the holding member 2, the movable floor 4 exhibits the same operation as that of the seismic device K1 of the above-described embodiment. In this example, for the second linear actuator 7, the holding member 2, the movable floor 4, the linear actuator 3 and the spring element 5 are vibrated, so the natural frequency in the system of these and the second spring element 8 is Thus, the second linear actuator 7 is driven at the natural frequency. Specifically, the natural frequency may be obtained from the mass obtained by adding the traveling wheel 2c to the same member as the seismic device K1 and the spring constant of the second spring element 8.

  By configuring the seismic device K2 in this way, the movable floor 4 is vibrated by the linear actuator 3 and the second linear actuator 7 that expand and contract in different directions, so that the movable floor 4 is vibrated with two degrees of freedom. It will be possible to reproduce seismic motion that is closer to reality.

  Further, since the holding member 2 can be vibrated with an amplitude greater than or equal to the stroke length of the second linear actuator 7, it is natural that long-period ground motion can be reproduced while avoiding an increase in the size of the apparatus.

  As described above, the relationship between the second holding member 6 and the holding member 2 corresponds to the relationship between the holding member 2 and the movable floor 4 in the embodiment shown in FIG. Of course, as described in the detailed description of the holding member 2 and the movable floor 4, various structures can be adopted.

  Further, in the illustrated case, the second linear actuator 7 and the linear actuator 3 move the movable floor 4 in the horizontal direction, but in the vertical direction in the reciprocating direction of one or both of the movable parts. You may make it include a component. In this case, when a linear guide is provided between the holding member 2 and the second holding member 6 and between the movable floor 4 and the holding member 2 so that the movable floor 4 can be vibrated without being tilted. Good.

  Furthermore, the reciprocating direction of the movable part of the second linear actuator 7, the reciprocating direction of the movable part M of the linear actuator 3, the moving direction of the movable floor 4, and the moving direction of the holding member 2 are made to coincide. It is also possible. In this case, the holding member 2 resonates due to the expansion and contraction of the second linear actuator 7, and the movable floor 4 also resonates in the same direction as the holding member 2 due to the expansion and contraction of the linear actuator 3. Can be made larger than the seismic device K1.

  Finally, the seismic device K3 of another embodiment shown in FIG. 4 will be described. The seismic device K3 is configured to vibrate the movable floor 4 in the directions of three axes.

  As shown in FIG. 4, the seismic device K <b> 3 is provided with a third holding member 9, a third linear actuator 10, and a third spring element 11 in addition to the seismic device K <b> 2 of another embodiment.

  Specifically, unlike the expansion / contraction direction of the linear actuator 3 and the expansion / contraction direction of the second linear actuator 7 between the second holding member 6 and the third holding member 9, an in-plane including the expansion / contraction direction of the actuators 3, 7 is included. A third linear actuator 10 that expands and contracts in a direction that is not present and a third spring element 11 are connected in series. Although not shown in detail, the third linear actuator 9 includes a movable portion that reciprocates in the linear direction, like the linear actuator 3, and can use various linear actuators. 11 is the same as the spring element 5. 4, the illustration of the traveling wheel 4b of the movable floor 4 and the traveling wheel 2c of the holding member 2 is omitted because the drawing is complicated. 4 indicates the reciprocating direction of the movable part of the actuator 3, and the broken line arrow indicates the reciprocating direction of the movable part of the second actuator 7. Further, in FIG. A chain line arrow indicates a reciprocating direction of the movable portion of the third actuator 10.

  The vibration in the three directions of the movable floor 4 is given by the linear actuator 3, the second linear actuator 7, and the third linear actuator 10, but the directions of the three axes do not necessarily have to be orthogonal to each other. The expansion / contraction directions of the linear actuators 3, 7, and 10 are all different, and one of the three linear actuators 3, 7, and 10 is not in the plane including the remaining two expansion / contraction directions, The movable floor 4 can be vibrated three-dimensionally.

  In this embodiment, the second holding member 6 is caused to vibrate in the vertical direction with respect to the third holding member 9. For this purpose, the third holding member 9 holds one end of the third linear actuator 10. The base 9a includes a guide rail 9b that rises from the base 9a. The second holding member 6 includes a slider 6c that slidably holds the guide rail 9b.

  A third spring element 11 is interposed between the traveling floor 6 a of the second holding member 6 and the other end of the third linear actuator 10, and the second linear actuator 10 can be expanded and contracted to extend the second As shown in FIG. 3, the holding member 6 can be vibrated in the direction of the one-dot chain line. The relationship between the third holding member 9 and the second holding member 6 in this other embodiment is shown in FIG. 3 as the relationship between the holding member 2 and the movable floor 4 in the embodiment shown in FIG. This corresponds to the relationship between the second holding member 6 and the holding member 2 in another embodiment. Therefore, the second holding member 6 is attached to the third holding member 9 by the third linear actuator 10 and the third spring element 11 interposed between the third holding member 9 and the second holding member 6. In addition to the vibration, the amplitude of the third linear actuator 10 is amplified, so that the amplitude exceeds the stroke length of the third linear actuator 10.

  In addition, in the seismic device K3 in another embodiment, since it has the same configuration as in the other embodiments, on the second holding member 6, the holding member 2 and the movable floor 4 have the above-described configuration. The same operation as that of the seismic device K2 of other embodiments is exhibited. In the case of this example, for the third linear actuator 10, the natural frequency is obtained from the mass obtained by adding the slider 6 c to the member corresponding to the seismic device K 2 and the spring constant of the third spring element 11. Thus, the third linear actuator 10 is driven.

  By constructing the seismic device K3 in this manner, the movable floor 4 can be vibrated in three axial directions, and the movable floor 4 can be vibrated three-dimensionally, so that the earthquake motion can be reproduced more precisely. become able to.

  Further, since the second holding member 6 can be vibrated with an amplitude equal to or greater than the stroke length of the third linear actuator 10, it is natural that long-period ground motion can be reproduced while avoiding an increase in the size of the apparatus.

  As described above, the relationship between the third holding member 9 and the second holding member 6 corresponds to the relationship between the holding member 2 and the movable floor 4 as described above. As described in the detailed description of the movable floor 4 and the movable floor 4, various structures can naturally be employed.

  Further, in the present embodiment, the second holding member 6 is caused to vibrate in the vertical direction with respect to the third holding member 9, but the holding member 2 is caused to vibrate in the vertical direction with respect to the second holding member 6. Naturally, it is possible to adopt a mode in which the movable floor 4 is vibrated in the vertical direction relative to the holding member 2.

  Furthermore, the reciprocating direction of the movable part of the third linear actuator 10, the reciprocating direction of the movable part of the second linear actuator 7, the reciprocating direction of the movable part M of the linear actuator 3, and the moving direction of the movable floor 4. It is also possible to make the movement direction of the holding member 2 coincide with the movement direction of the second holding member 5. In this case, the second holding member 6 resonates due to the expansion / contraction of the third linear actuator 10, the holding member 2 resonates due to the expansion / contraction of the second linear actuator 7, and the movable floor 4 is also held by the expansion / contraction of the linear actuator 3. Since the resonance occurs in the same direction as the member 2, the amplitude of the vibration of the movable floor 4 can be made larger than that of the seismic device K1.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

  The seismic device of the present invention can be used in an earthquake simulator or the like for experiencing an earthquake motion or giving an experiment and performing an experiment.

2 holding member 3 linear actuator 5 spring element 6 second holding member 7 second linear actuator 8 second spring element 9 third holding member 10 third linear actuator 11 third spring element M movable parts K1, K2, K3

Claims (5)

A linear actuator having a movable part that can reciprocate in a linear direction, a spring element that expands and contracts by reciprocating movement of the movable part, a holding member that holds one of the linear actuator and the spring element, and the holding member A movable floor capable of relative movement in the same direction as the reciprocating direction of the movable portion, and the linear actuator and the spring element are connected in series between the holding member and the movable floor. Seismic device characterized by wearing. One of a second linear actuator having a movable part that can reciprocate in a linear direction, a second spring element that expands and contracts by a reciprocating movement of the movable part of the second linear actuator, and the second linear actuator and the second spring member A second holding member for holding one of the holding members, and the holding member can be moved relative to the second holding member at least in the same direction as the moving direction of the movable portion of the second linear actuator, The seismic device according to claim 1, wherein the second linear actuator and the second spring element are connected in series and interposed between a member and the second holding member. The seismic device according to claim 2, wherein the reciprocating direction of the movable part of the linear actuator is different from the reciprocating direction of the movable part of the second linear actuator. One of a third linear actuator having a movable part that can reciprocate in a linear direction, a third spring element that expands and contracts by a reciprocating movement of the movable part of the third linear actuator, and the third linear actuator and the third spring element A third holding member for holding one, and the second holding member is capable of relative movement with respect to the third holding member at least in the same direction as the reciprocating direction of the movable portion of the third linear actuator. The third linear actuator and the third spring element are connected in series between the second holding member and the third holding member, and are interposed between the second holding member and the third holding member. Seismic device. The reciprocating direction of the movable part of the third linear actuator is not included in a plane including both the reciprocating direction of the movable part of the linear actuator and the reciprocating direction of the movable part of the second linear actuator. The seismic device according to claim 4.

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