JP3643765B2 - Centrifugal loading device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is suitable for carrying out various tests by loading a test object with a centrifugal force, and particularly relates to a centrifugal force loading device capable of reducing the capacity of a rotational drive means.
[0002]
[Prior art]
A conventional general centrifugal loading device includes a rotating shaft supported at the center of a cylindrical pit, a motor for rotating the rotating shaft, a rotating arm fixed to the rotating shaft in a horizontal direction, And a bucket attached so as to be swingable around a pin provided at the tip of the rotary arm.
[0003]
When performing a test with such a centrifugal loading device, first, a test body is installed in the bucket, and the rotating arm is rotated at a high speed by a motor. Thereby, the hanging bucket is swung up by centrifugal force, and the bottom surface of the bucket faces the side surface of the pit. Further, when the rotating arm rotates at a high speed while the bucket is swung up, a centrifugal force is loaded on the test body and a gravitational acceleration is applied. At this time, when a 1 / N scale model of a real object is used as a test object, experimental data can be obtained under the same conditions as those of the actual experiment by applying N times gravity acceleration to the test object.
[0004]
As the test body, for example, an actual 1 / N scale ground model is stored in a test container, and the actual 1 / N scale shield machine model or deep shaft model is set in the ground model. Or an actual 1 / N scale ground model stored in a test container and a vibration device attached to the test container. Further, as this type of centrifugal force loading device, those described in JP-A-10-176972, JP-A-10-300639, and the like are known.
[0005]
[Problems to be solved by the invention]
Since the centrifugal force loading device rotates a rotating body such as a rotating arm and a bucket at high speed in the pit, windage resistance is generated between the rotating body and the top, side and bottom surfaces of the pit. . In particular, since the peripheral speed becomes maximum at the bottom surface of the bucket that is the tip of the rotating body, the windage resistance becomes maximum between the bottom surface of the bucket and the side surface of the pit. For this reason, in the conventional centrifugal loading device, it is necessary to determine the motor capacity in consideration of such windage resistance, and there is a problem that the motor capacity increases correspondingly. This is the same even when a rotational drive means other than a motor is used.
[0006]
Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a centrifugal force loading device capable of reducing the capacity of a rotation driving means such as a motor.
[0007]
[Means for Solving the Problems]
In order to achieve the above-described object, a centrifugal force loading device according to claim 1 is a rotating shaft that is rotatably supported on a vertical central axis in a cylindrical pit, and a rotation driving unit that rotates the rotating shaft. A centrifugal loading device comprising: a rotary arm fixed in a horizontal direction to the rotary shaft; and a bucket that swings due to centrifugal force at a tip of the rotary arm and mounts a test specimen. Sealing means for sealing between the bottom surface of the bucket and the side surface of the pit is provided on the bottom surface of the bucket facing the side surface of the pit .
[0008]
In this way, by sealing between the bottom surface of the bucket and the side surface of the pit where the windage resistance becomes maximum, the windage resistance between the bottom surface of the bucket and the side surface of the pit can be extremely reduced. For this reason, it becomes possible to reduce the capacity | capacitance of a rotational drive means. In addition, as a rotational drive means, a motor, a turbine, etc. can be used, for example.
[0009]
In addition, as such a sealing means, a leaf seal (Claim 2) constituted by a plurality of flexible plates having one edge fixed to the bottom surface of the bucket, or a plurality of ones having one end fixed to the bottom surface of the bucket. The brush seal (Claim 3) constituted by the flexible wire, the air curtain (Claim 5) formed by jetting air from the bucket end, and the like. In particular, according to the leaf seal or the brush seal, the sealing means can be easily configured.
[0010]
Further, it is possible to further improve the sealing performance by forming the outer portion of the leaf seal or the brush seal into an arc shape that follows the arc of the side surface of the pit. Further, even if the sealing means is provided on the side surface of the pit facing the bottom surface of the bucket by the rotation of the rotating arm, the windage resistance between the bottom surface of the bucket and the side surface of the pit is extremely reduced as described above. (Claim 6). Moreover, the said structure can also be applied to the rotating arm of a cantilever structure (Claim 7).
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.
[0012]
(Embodiment 1)
FIG. 1 is a configuration diagram showing a centrifugal loading device according to Embodiment 1 of the present invention. This centrifugal force loading device is installed in a cylindrical pit dug in the foundation. Moreover, the upper surface 2, the side surface 3, and the bottom surface 4 of the pit 1 are made of concrete, and the surface thereof is rough. A support base 5 is installed at the center of the bottom surface 4 of the pit 1. The lower end of the rotary shaft 6 is rotatably supported on the support base 5, and the rotary shaft 6 is disposed on the vertical center axis in the pit 1. Further, the support 5 is provided with a rotation driving means comprising a motor 7 and a reduction gear or other rotational force transmission mechanism (not shown) provided between the motor 7 and the rotation shaft. It has been.
[0013]
A rotating arm 8 is fixed in a horizontal direction (a direction orthogonal to the rotating shaft 6) at substantially the middle of the rotating shaft 6. The rotating arm 8 has both structures extending from the rotating shaft 6 in both directions, and forms a beam or truss structure that is symmetrical about the rotating shaft 6. Buckets 9 and 10 are swingably attached to both ends of the rotary arm 8 by pins 11 and 12, respectively. The axes of the pins 11 and 12 are located in a direction perpendicular to the vertical central axis direction of the rotating shaft 6 and the horizontal extending direction of the rotating arm 8. A test body 13 is mounted on one bucket 9, and a counterweight 14 is mounted on the other bucket 10. As a result, a balance is maintained between the weights of the rotary arm 8, the bucket 9 and the test body 13 on the one side with respect to the rotary shaft 6 and the weights of the rotary arm 8, the bucket 10 and the counterweight 14 on the other side.
[0014]
The buckets 9 and 10 are in a suspended state as indicated by a two-dot chain line in FIG. 1 when the centrifugal force loading device is stopped. The test body 13 is provided with a CCD camera for measuring the test state and its camera illumination 15. Further, a strobe camera 16 for measuring the test state is provided on the upper surface 2 of the pit 1. On the upper surface 2 of the pit 1, a monitoring camera 17 for monitoring the centrifugal loading device and its camera illumination 18 are also provided. Further, a switch 19 is provided on the side surface 3 of the pit 1 to make an emergency stop of the centrifugal force loading device.
[0015]
An electronic device mounting portion 20 is provided substantially in the middle of the rotating shaft 6. A wireless LAN transmitting antenna 22 and a wireless LAN receiving antenna 23 are provided at the upper end of the rotating shaft 6 and the dome 21. The dome 21 is provided on the upper lid 24 constituting the upper surface 2 of the pit 1. A rotary joint 25 and a slip ring 26 are provided at the upper end of the rotating shaft 6. The rotary joint 25 supplies pressure oil, test water, and air from the external hydraulic pressure supply device 27, test water supply device 28, and air source device 29 to the test body 13.
[0016]
The slip ring 26 connects an external control device (not shown) to the CCD camera 15 and a real 1 / N scale device model. An automatic balance device 30 is built in the rotating arm 8. The automatic balance device 30 includes a motor 31, a feed screw rod 32 that rotates by driving the motor 31, and a balance weight 33 that moves forward and backward by the feed action of the feed screw rod 32. The above is the structure of a general centrifugal loading device.
[0017]
Next, in the centrifugal force loading device of the present invention, as shown in FIGS. 2 and 3, sealing means is provided on the bottom surfaces of the buckets 9 and 10. The sealing means includes a leaf seal 34 made of a plurality of flexible plates, for example, metal thin plates (so-called leaf springs) such as aluminum thin plates. As shown in FIGS. 1 to 3, the leaf seal 34 is configured such that a plurality of flexible plates are erected vertically at almost equal intervals, one edge is fixed to the bottom surfaces of the buckets 9 and 10, and the other edge is free. This is the configuration. The free side edge (tip) of the leaf seal 34 has an arc shape that follows the arc of the side surface 3 of the pit 1. Further, when the centrifugal force loading device is driven, the elastic force of the leaf seal is appropriately adjusted so that a gap (not shown) between the tip of the leaf seal 34 and the side surface 3 of the pit 1 is floated on the order of microns. Determine the area.
[0018]
Next, the operation of the centrifugal loading device will be described. By driving the motor 7, the rotary arm 8 rotates via the rotary shaft 6. Along with this, the suspended buckets 9 and 10 are swung up around the pins 11 and 12 by centrifugal force, and the bottom surfaces of both buckets 9 and 10 face the side surface 3 of the pit 1. Then, the rotating bodies such as the buckets 9 and 10 and the rotating arm 8 that have been swung up are continuously rotated at high speed, whereby a centrifugal force is loaded on the test body 13 mounted on one of the buckets 9 and a predetermined gravitational acceleration is applied. It is done.
[0019]
Further, when the rotary arm rotates at a high speed, wind pressure is applied to the leaf seal 34, and the tip thereof is bent to form a micron-order gap with the side surface 3 of the pit 1. For this reason, even if the side surface 3 of the pit 1 is a rough surface, it can be suitably sealed by the leaf seal 34.
[0020]
As described above, the centrifugal force loading device according to the first embodiment can seal between the bottom surfaces of the buckets 9 and 10 where the windage resistance is maximized and the side surface 3 of the pit 1 by the leaf seal 34. Therefore, the windage resistance between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1 can be reduced as much as possible. For this reason, the windage resistance can be significantly reduced as compared with the conventional centrifugal loading device, and accordingly, the capacity of the motor 7 can be reduced when the same gravity acceleration is applied. Become. Further, the seal between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1 can be performed with a simple configuration.
[0021]
Further, the leaf seal 34 according to the first embodiment has an arc shape whose tip follows the arc of the side surface 3 of the pit 1, so that the sealing performance between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1 is achieved. Can be further improved, and wind resistance can be further reduced.
[0022]
(Embodiment 2)
4 and 5 are partial configuration diagrams showing a centrifugal loading device according to Embodiment 2 of the present invention. In the figure, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The sealing means in the second embodiment is constituted by a brush seal 35 made of a plurality of flexible wires, for example, metal fine wires such as aluminum fine wires. The brush seal 35 is configured such that one end of a large number (numerous) flexible thin wires is fixed to the bottom surfaces of the buckets 9 and 10 and the other end is free. Further, the free end (tip) of the brush seal 35 has an arc shape that follows the arc of the side surface 3 of the pit 1. Further, when the centrifugal force loading device is driven, the elastic force of the leaf seal is appropriately adjusted so that a gap (not shown) between the tip of the leaf seal 34 and the side surface 3 of the pit 1 is floated on the order of microns. Determine the area. Even if the brush seal 35 is used in this way, the same effect as in the first embodiment can be obtained.
[0023]
(Embodiment 3)
6 and 7 are partial configuration diagrams showing a centrifugal loading device according to Embodiment 3 of the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The sealing means in the third embodiment is composed of an air curtain 37 (shown by a solid line arrow in FIG. 6) formed by an air injection mechanism 36. That is, the air injection mechanism 36 includes a compressor 38 mounted on the buckets 9, 10, an injection port 39 formed in a vertical direction on the bottom surfaces of the buckets 9, 10, and the injection port 39 and the compressor 38. And an air supply path 40 provided between the two. The injection port 39 has an elongated slit shape in a direction perpendicular to the rotation direction. Further, the slit may be formed slightly inclined from the direction shown in FIG.
[0024]
When the compressor 38 is driven, compressed air is injected from the injection port 39 to the side surface 3 of the pit 1 through the air supply path 40, and the air curtain 37 is interposed between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1. Is formed. For this reason, the space between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1 is suitably sealed by the air curtain 37.
[0025]
For example, when the peripheral speed of the bottom surfaces of the buckets 9 and 10 is 20 m / s to 40 m / s, if the injection speed of the compressed air from the injection port 39 is set to 200 m / s, the air curtain 37 causes the buckets 9 and 10 to It has been theoretically and experimentally found that a good seal is provided between the bottom surface of the pit and the side surface 3 of the pit 1. In order to set the jet speed of the compressed air from the jet port 39 to 200 m / s, the width of the jet port 39 may be set to 10 mm. In order to obtain the speed at the width, a small compressor pressure (for example, A compressor 38 of ^{2 to 3} kg / cm ² suffices. Note that the external air source device 29 and the injection port 39 may be connected via the rotary joint 25 without using the compressor 38. Thus, even when the sealing means of the air curtain 37 is used, the same effect as in the first embodiment can be obtained.
[0026]
(Embodiment 4)
FIG. 8: is a partial block diagram which shows the centrifugal force loading apparatus concerning Embodiment 4 of this invention. In addition, in the figure, the same code | symbol is attached | subjected to the component same as Embodiment 1, and the description is abbreviate | omitted. In this centrifugal force loading device, a leaf seal 41 made of a plurality of flexible plates, for example, metal thin plates such as aluminum thin plates (so-called leaf springs) is provided on the side surface 3 of the pit 1 facing the bottom surfaces of the buckets 9 and 10. There is a feature in the point. The leaf seal 41 has a configuration in which a plurality of flexible plates are vertically set at substantially equal intervals, one edge thereof is fixed to the side surface 3 of the pit 1 and the other edge (tip) is free. Also with such a configuration, the space between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1 can be suitably sealed, so that substantially the same effect as the centrifugal force loading device of the first embodiment can be obtained. .
[0027]
(Embodiment 5)
FIG. 9: is a partial block diagram which shows the centrifugal loading apparatus concerning Embodiment 5 of this invention. In addition, in the figure, the same code | symbol is attached | subjected to the component same as Embodiment 1, and the description is abbreviate | omitted. This centrifugal force loading device is characterized in that a brush seal 42 made of a plurality of flexible wires, for example, metal fine wires such as aluminum fine wires, is provided on the side surface 3 of the pit 1 facing the bottom surfaces of the buckets 9 and 10. . The brush seal 42 is configured such that one end of a large number (numerous) flexible thin wires is fixed to the side surface 3 of the pit 1 and the other end (tip) is free. Also with such a configuration, the space between the bottom surfaces of the buckets 9 and 10 and the side surface 3 of the pit 1 can be suitably sealed, so that substantially the same effect as the centrifugal force loading device of the first embodiment can be obtained. .
[0028]
(Embodiment 6)
FIG. 10: is a partial block diagram which shows the centrifugal force loading apparatus concerning Embodiment 5 of this invention. This centrifugal force loading device has a cantilever structure in which a rotating arm 43 is extended from the rotating shaft 6 in one direction. A bucket 9 on which the test body 13 is mounted is attached to a tip of the rotating arm 43 so as to be swingable by a pin 11. For example, a leaf seal 34 is provided on the bottom surface of the bucket 9. A counterweight 44 is attached to the other end of the rotating arm 43.
[0029]
According to this centrifugal force loading device, the windage resistance can be reduced as much as the one-side rotary arm 8 is omitted, so that the capacity of the motor can be further reduced. In the centrifugal loading device, the leaf seal 34 is provided on the bottom surface of the bucket 9, but a brush seal 35 or an air injection mechanism 36 may be provided instead. Alternatively, the tips of the leaf seal 34 and the brush seal 35 provided on the bottom surface of the bucket 9 may have an arc shape that follows the arc of the side surface 3 of the pit 1. Furthermore, instead of providing air seal means on the bottom surface of the bucket 9, air seal means (leaf seal 41, brush seal 42) may be provided on the side surface 3 of the pit 1.
[0030]
【The invention's effect】
As described above, in the centrifugal load device according to the present invention (Claim 1), the windage resistance is maximized by providing the sealing means on the bottom surface of the bucket facing the side surface of the pit by the rotation of the rotary arm. It is possible to seal between the bottom surface of the bucket and the side surface of the pit. For this reason, the windage resistance can be made extremely small between the bottom surface of the bucket and the side surface of the pit, and the capacity of the rotation driving means can be reduced. Even when the sealing means is provided on the side surface of the pit, the same effect can be obtained (claim 6).
[0031]
Further, as a sealing means, a leaf seal (Claim 2) constituted by a plurality of flexible plates having one edge fixed to the bottom surface of the bucket, or a plurality of flexible wires having one end fixed to the bottom surface of the bucket. The constructed brush seal (Claim 3), an air curtain (Claim 5) formed by injecting air from the bucket end, etc. can be used. Easy to configure.
[0032]
Further, it is possible to further improve the sealing performance by forming the outer portion of the leaf seal or the brush seal into an arc shape that follows the arc of the side surface of the pit. These configurations can also be applied to a rotating arm having a cantilever structure (claim 7). In the case of a rotating arm having a cantilever structure, the windage resistance can be further reduced, so that the capacity of the rotation driving means can be further reduced.
[Brief description of the drawings]
FIG. 1 is an overall schematic side view showing Embodiment 1 of a centrifugal force loading device of the present invention.
FIG. 2 is a view as seen from an arrow A during driving in FIG. 1 of the first embodiment.
FIG. 3 is a view taken in the direction of an arrow B in FIG.
FIG. 4 shows a centrifugal loading device according to a second embodiment of the present invention, and is a view taken along arrow A in FIG. 1 during driving.
FIG. 5 is a view as seen from an arrow B in FIG.
6 shows Embodiment 3 of the centrifugal force loading device of the present invention, and is a view taken along arrow A in FIG. 1 during driving. FIG.
7 is a view as seen from the direction of arrow B in FIG.
8 shows a centrifugal loading device according to a fourth embodiment of the present invention, and is a view taken along arrow A in FIG. 1 during driving.
FIG. 9 shows a centrifugal force loading device according to a fifth embodiment of the present invention, and is a view taken along arrow A in FIG. 1 during driving.
FIG. 10 is an overall schematic side view showing a sixth embodiment of the centrifugal force loading device of the invention.
[Explanation of symbols]
1 Pit 3 Side 6 Rotating shaft 7 Motor (Rotation drive means)
8 Rotating arm (both structures)
9, 10 Bucket 11, 12 Pin 13 Specimen 34, 41 Leaf seal (sealing means)
35, 42 Brush seal (sealing means)
36 Air injection mechanism 37 Air curtain 43 Rotating arm (single structure)

Claims (9)

A rotating shaft rotatably supported on a vertical central axis in a cylindrical pit, a rotation driving means for rotating the rotating shaft, a rotating arm fixed to the rotating shaft in a horizontal direction, and In the centrifugal force loading device provided with a bucket that swings at the tip due to centrifugal force and carries a test specimen,
The bottom surface of the bucket opposed to the side of the pit by the rotation of the rotating arm, the sealing means for sealing between the side surface of said the bottom surface of the bucket pit, centrifugal force loading apparatus characterized by comprising.   The centrifugal loading device according to claim 1, wherein the sealing means is a leaf seal composed of a plurality of flexible plates, one edge of which is fixed to the bottom surface of the bucket.   2. The centrifugal force loading device according to claim 1, wherein the sealing means is a brush seal composed of a plurality of flexible wires, one end of which is fixed to the bottom surface of the bucket.   The centrifugal force loading device according to claim 2 or 3, wherein an outer portion of the leaf seal or the brush seal has an arc shape that follows an arc of a side surface of the pit.   The centrifugal loading device according to claim 1, wherein the sealing means is an air curtain formed by injecting air from the bucket end. A rotating shaft rotatably supported on a vertical central axis in a cylindrical pit, a rotation driving means for rotating the rotating shaft, a rotating arm fixed to the rotating shaft in a horizontal direction, and In the centrifugal force loading device provided with a bucket that swings at the tip due to centrifugal force and carries a test specimen,
The sides of the pit which faces the bottom surface of the bucket by the rotation of the rotating arm, the sealing means for sealing between the side surface of said the bottom surface of the bucket pit, centrifugal force loading apparatus characterized by comprising. The centrifugal force loading device according to claim 6, wherein the sealing means is a leaf seal composed of a plurality of flexible plates, one edge of which is fixed to a side surface of the pit. The centrifugal force loading device according to claim 6, wherein the sealing means is a brush seal composed of a plurality of flexible wires, one end of which is fixed to a side surface of the pit. The rotary arm, centrifugal force loading device according to any one of claims 1-8, characterized in that the said rotary shaft is a cantilever structure that extends in one direction.

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