JP4948153B2 - Centrifugal loading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal force loading device having a short rotation arm length, placeable on a narrow space, capable of loading a great centrifugal force onto an experimental sample. <P>SOLUTION: On one end side of the rotation arm, a platform 7 for both dynamic and static experiments suspended rockably between horizontal beams 4<SB>1</SB>, 4<SB>2</SB>is provided, and a back plate 10 for preventing vibration caused by a reaction at a sample excitation time by seating thereon an outer surface bottom part of the platform 7 in the swung-up state horizontally by a centrifugal force is provided. On the other end side of the rotation arm, a platform 12 for an exclusive static experiment having no back plate mechanism suspended rockably between the pair of horizontal beams 4<SB>1</SB>, 4<SB>2</SB>is provided, and each balance weight 14, 14 is provided on the outward of a suspension position of the platform for the exclusive static experiment of the pair of horizontal beams, to be supported by frame bodies 16, 16 wherein the center shaft of the balance weight is positioned on a straight line P connecting the center Q of the balance weight to the center S of a rotating shaft 1. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention reproduces the full-scale weight of the above-mentioned embankment, ground, etc. by applying a centrifugal force according to the scale scale for strength experiments, etc. of embankment, ground, etc., using these scale models. This relates to the structure of a centrifugal loading device.

  As this type of centrifugal force loading device, one having a structure as shown in FIG. 6 is generally known. That is, the rotating shaft 1 vertically supported by the centrifuge base 2, the rotating arm 4 attached to the rotating shaft 1 and rotating horizontally around the rotating shaft 1, the rotating shafts 1 at both ends of the rotating arm 4, etc. A pair of platforms 17, 17, which are swingably suspended by a horizontal axis 8 perpendicular to the rotary arm 4, are provided at a distance, and the scale model 9 of the sample is placed on one platform 17, while the other When a dummy weight 18 is placed on the platform 17 and rotation is applied to the rotary shaft 1 to rotate the rotary arm 4 at a high speed, the pair of platforms 17 and 7 are swung up to a position parallel to the rotary arm 4, This is a mechanism in which centrifugal force is applied to the scale model 9.

  By the way, there are a static experiment and a dynamic experiment in an experiment performed using such a centrifugal loading device. A static experiment is an experiment related to ground stabilization, such as deep underground excavation or uneven settlement of a building. For example, a centrifugal force due to high-speed rotation of the rotary arm 4 is simply applied to the scale model 9 for a long time. It is an experiment to be performed. The dynamic experiment is, for example, an experiment for predicting the behavior of the ground and the structure at the time of an earthquake. A centrifugal force due to high-speed rotation of the rotary arm 4 is applied to the scale model 9 of the sample, and vibration and the like are applied. It is an experiment that gives power.

  However, in the centrifugal loading device having the structure shown in FIG. 6, a dynamic experiment could not be accurately performed even though a static experiment could be performed. That is, in the centrifugal force field where the rotating arm 4 rotates at a high speed, if vibration is applied to the scale model 9 of the sample mounted on the platform 17 swung up horizontally by a vibration table or the like, the entire platform 17 is caused by the reaction force. As a result, the seismic wave to be vibrated on the scale model 9 cannot be accurately reproduced.

  For this reason, in a recent centrifugal loading device, as shown in FIG. 7, as shown in FIG. The back plate 10, 10 of the platform 17 is provided so that the bottom of the platform 17 in the state of being swung up is seated and the movement such as vibration caused by the reaction force is absorbed. As a result, it was possible to accurately reproduce seismic waves in dynamic experiments as well as static experiments. (See Patent Document 1)

JP 2002-357511 A

  However, the centrifugal loading device with the back plates 10 and 10 has the back plate 10 as compared with the conventional centrifugal loading device having the same overall length L of the rotary arm 4 and no seating portion. Accordingly, the effective radius R ′ (the distance from the center S of the rotating shaft 1 to the sample mounting surface of the platform that is swung up horizontally by centrifugal force) is shortened, and the scale model 9 of the material placed on the platform 17 is reduced. On the other hand, the centrifugal force loaded becomes small. Therefore, when compared with the same level of performance, when a centrifugal loading device with a back plate 10 is newly introduced, the total length L of the rotating arm 4 is inevitably higher than that of a conventional centrifugal loading device without a back plate. Since the installation space is long and large, the conventional installation space cannot be used as it is, and installation work for the installation space or the need to prepare another wide installation space arises. There were a lot of cases.

  The present invention has been made to solve such problems, and has a structure in which a dynamic experiment can be performed by providing a platform back plate on a rotating arm, but the rotating arm has a short length and is installed in a narrow space. An object of the present invention is to provide a centrifugal loading device capable of applying a large centrifugal force to a scale model of a material placed on a platform during a static experiment.

  The centrifugal loading device of the present invention that achieves the above object is supported by a vertical rotating shaft that is rotationally driven by power, and one end side of a rotating arm that is composed of a pair of horizontal beams facing each other across the rotating shaft. In addition, a dynamic and static experimental platform suspended in a swingable manner between the horizontal beams is provided and the bottom of the outer surface of the dynamic and static experimental platform swung horizontally by centrifugal force. A back plate that prevents the vibration due to the reaction force when the sample is vibrated is provided, and the other end of the rotating arm has no back plate mechanism that swings freely between the pair of horizontal beams. In addition to providing an experimental platform, a pair of horizontal beams is provided outside the above-described static experimental platform suspension position of the pair of horizontal beams. , It is configured to be supported by a stretchable frame body that protrudes outward from the outer surface of each corresponding horizontal beam and whose center axis is located on a straight line that connects the center of the balance weight and the rotation axis center. Features.

  In this case, the balance weight is preferably provided in a weight-adjustable structure in which a plurality of weights are stacked through pins at the center, and the frame body that supports the balance weight has a structure that can be expanded and contracted in the axial direction. Is desirable. Further, it is preferable that the rotary arm has a fine balance adjustment function that horizontally moves a certain amount to the one end side or the other end side around the rotation axis.

  According to the centrifugal loading device of the present invention having the above-mentioned configuration, the platform for exclusive use in static experiments is provided with a platform for both dynamic and static experiments in which one end side of the rotary arm has a back plate and the other end side has no back plate. It has a structure with. Therefore, the total length of the rotary arm is shorter than that of the rotary arm provided with the back plate at both ends, and the rotary arm can be installed in a narrow space. In addition, both dynamic and static experiments are possible. Particularly in static experiments, a large effective radius can be secured, and a large centrifugal force can be applied to the experimental sample.

  In addition, the unbalance in weight due to the structural difference between the one end side and the other end side of the rotating arm is eliminated by adjusting the weight of the balance weight provided on the other end side of the rotating arm, so the rotating arm is always smooth. It will not interfere with the experiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show an example in which a centrifugal loading device according to the present invention is installed in an underground pit. 1 is a rotating shaft, 4 is a rotating arm, 7 is a platform for both dynamic and static experiments, and 10 is a back. The plate, 12 is a platform for static experiments, and 14 and 14 are balance weights.

  That is, the rotating shaft 1 is vertically supported by the centrifugal base 2 at a substantially central portion in the pit, and is rotated by the power M. In addition, a slip ring 3 is provided on the top of the rotary shaft 1, and information from various measuring instruments attached to the inside of the apparatus can be taken out via the slip ring 3.

The rotating arm 4 is attached to the central portion of the rotating shaft 1 and rotates horizontally as the rotating shaft 1 rotates. As shown in FIG. 4, the rotating arm 4 is composed of a pair of horizontal beams 4 ₁ and 4 ₂ facing each other across the rotating shaft 1, and the central portions of these horizontal beams 4 ₁ and 4 ₂ are rotated. It is attached so as to be sandwiched between upper and lower plate-like frames 5a and 5b for mounting a measuring instrument fixed around the shaft 1. In the illustrated example, hydraulic cylinders 6 and 6 for fine adjustment of balance are incorporated between the upper and lower plate frames 5a and 5b to which the horizontal beams 4 ₁ and 4 ₂ are attached, and these hydraulic cylinders 6 and 6 are synchronized. When it is extended or contracted, the entire rotary arm 4 slides between the plate-like frames 5a and 5b in the direction of the one end 4 ′ or the other end 4 ″ depending on the amount.

On one end side 4 ′ of the rotating arm 4, a platform 7 for both dynamic and static experiments and a back plate 10 are provided. A platform 7 for both dynamic and static experiments suspended between a pair of horizontal beams 4 ₁ and 4 ₂ has a groove-like frame shape, and side wall surfaces 7b on both sides of the flat sample mounting surface 7a. 7b upper end portions are rotatably attached to the corresponding horizontal beams 4 ₁ and 4 ₂ by shafts 8 and 8, respectively. When the rotating arm 4 rotates and a centrifugal force is applied, the scale mounting model 9 or the sample mounting surface 7a on which the counterweight is mounted swings in parallel with the horizontal beams 4 ₁ and 4 _2. Yes. Further, the platform 7 has an outer surface bottom portion 7c formed in an arc surface so that it can be easily seated on a back plate 10 described later.

The back plate 10 is provided between the extended portions 4 ₁ ′ and 4 ₂ ′ by extending the pair of horizontal beams 4 ₁ and 4 ₂ on the other end side 4 ′ of the rotating arm 4 by a required length. On the inner surface side of the back plate 10, there is attached an arcuate seating deck 11 that fits closely with the outer bottom 7 c of the platform 7. When the platform 7 is swung up in parallel with the pair of horizontal beams 4 ₁ and 4 ₂ by centrifugal force, the seating deck 11 is seated by closely fitting the outer bottom 7c of the platform 7 to the deck surface. By doing so, the motions such as vibrations propagating to the platform 7 are absorbed by reaction forces of various applied forces during dynamic experiments.

Incidentally, the centrifugal force loading device of the illustrated example, the overall length L of the rotary arm 4 is 5355Mm, one end 4 'length L ₁ from the axis of rotation 1 center S at the up end 2750Mm, effective half the diameter R' Is 2200 mm. Further, the platform 7 has a height T of 1000 mm from the center of the shaft 8 from which it is suspended to the outer bottom surface 7c, and the sample mounting surface 7a has a size of 950 mm × 1100 mm.

The other end side 4 ″ of the rotary arm 4 is provided with a platform 12 dedicated to static experiments and balance weights 14 and 14, and is not provided with a back plate as described above. 12 has a groove-like frame shape substantially the same as the platform 7 on the one end side 4 ', but the flat sample mounting surface 12a is formed slightly larger than the platform on the one end side 4'. Thus, the scale model 9 or counterweight of a larger experimental sample can be mounted on the platform 12. The upper ends of the side wall surfaces 12b and 12b on both sides of the sample mounting surface 12a are respectively corresponding horizontal beams. 4 ₁ and 4 ₂ are rotatably suspended by shafts 13 and 13. When the rotating arm 4 rotates and a centrifugal force is applied, A sample mounting surface 12a on which the scale model 9 or the counterweight is mounted swings in parallel with the horizontal beams 4 ₁ and 4 _2. The outer surface bottom portion 12C of the platform 12 is formed on a flat surface.

As shown in FIG. 5, each of the balance weights 14 and 14 is formed by stacking a plurality of metal weights 14 '(in the illustrated example in a disk shape) in a plurality of stages through pins 15 at the center (total weight 500 kg). ) Therefore, the weight can be adjusted by adjusting the number of metal weights 14 'to be stacked. These balance weights 14 and 14 are both to be located in the horizontal beams 4 _1, 4 ₂ platform 12 suspended portion (shaft 13 mounting position) outside of the corresponding pair of horizontal beams 4 _1, 4 ₂ It is supported by support frames 16 and 16 protruding from the same position on the outer surface. Each support frame 16, 16 has an arm shape with a required length, and is arranged so that its central axis is located on a straight line P connecting the center Q of the balance weight 14 to be supported and the center S of the rotary shaft 1. It is. Each of the support frames 16 and 16 in the illustrated example is fixed to a certain length. However, the entire support frame is formed of a hydraulic cylinder or the like, and the position of each balance weight 14 and 14 is set to the straight line P by the expansion / contraction operation. It may be possible to adjust the movement along.

Incidentally, the length L ₂ from the center S to the end of the rotating shaft 1 at the other end side 4 ″ of the rotating arm 4 is 2605 mm, and the effective radius R ′ is 2380 mm. The platform 12 suspends it. The height T from the center of the shaft 13 to the external bottom surface 12c is 1080 mm, and the sample mounting surface 12a is 950 mm × 1500 mm.

  In order to use the centrifugal loading device of the present invention having the above-described configuration, first, it is determined whether an experiment to be performed is a dynamic experiment or a static experiment. In the case of a dynamic experiment, a scale model 9 of an experimental sample is mounted on both the dynamic and static experimental platform 7 suspended on one end side 4 ′ of the rotating arm 4 and the other end side 4 ″ is mounted. A counterweight having a weight suitable for the scale model is mounted on the platform 12. If the experiment is a static experiment, the rotating arm may be used when a relatively large centrifugal force is required due to its scale. The scale model 9 of the experimental sample is mounted on the platform 12 for static experiments on the other end side 4 ″, and a counterweight having a weight corresponding to the scale model is mounted on the platform 12 on the other end side 4 ″. In a static experiment that does not require centrifugal force, a scale model 9 of an experimental sample is mounted on the platform 7 on the one end side 4 ′.

  In both dynamic and static experiments, one end side 4 ′ of the rotary arm 4 provided with the back plate 10 is heavier than the other end side 4 ″ without the back plate, and the weight is unbalanced on both sides. Table 1 shows an example of this adjustment, which is adjusted in advance so as to balance when a centrifugal force is applied.

  That is, first, as the “unbalance amount at the time of stop”, the rotation axis in a state where the platforms 7 and 12 on both sides 4 ′ and 4 ″ of the rotary arm 4 before the start of the experiment are suspended (indicated by a solid line in FIG. 1). The total weight (4910 kgm) applied to one end side 4 '(both dynamic and static experimental platform 7 side) of the rotating arm 4 centered on 1, and the other end side of the rotating arm 4 also centered on the rotating shaft 1 The total weight (2998 kgm) applied to 4 ″ (the static experiment dedicated platform 12 side) is calculated.

  Next, as the “rotational unbalance amount”, the rotating arm 4 rotates based on the above calculated values, and the platforms 7 and 12 on both sides 4 ′ and 4 ″ are swung up horizontally by centrifugal force. The total weight (5384 kgm) of one end side 4 ′ (both dynamic and static experimental platform 7 side) of the rotating arm 4 in the state (shown by the imaginary line in FIG. 1) and the other end side 4 ″ The total weight (4000 kgm) of the static experiment dedicated platform 12 side is predicted and calculated.

  Then, the predicted value (4000 kgm) of the other end side 4 ″ (the static experiment dedicated platform 12 side) is the predicted value (5384 kgm) of the one end side 4 ′ (the dynamic and static experimental platform 7 side). The hydraulic cylinders 6 and 6 for fine balance adjustment are operated so as to approach as much as possible, and the weights of the balance weights 14 and 14 on the other end side 4 ″ of the rotary arm are adjusted.

  In the example of Table 1, the “balance weight adjustment amount” is “344 kg × 2 × 1.6 m = 1385.6 kgm”, and by this adjustment, one end side 4 ′ and the other end side 4 of the rotary arm 4 are obtained. "Unbalance amount" is 526.4 kgm when the rotating arm 4 is stopped, but only 1.6 kgm when the centrifugal force is applied, and a smooth rotational motion with a balanced weight balance is realized. ing.

It is a front view which shows an example of the centrifugal loading apparatus which concerns on this invention. It is a top view of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional enlarged view of FIG. It is a front view explaining an example of the conventional centrifugal force loading apparatus. It is a front view explaining an example of other conventional centrifugal loading devices.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 4 Rotating arm 4 ₁ and 4 ₂ pairs of horizontal beams 6 Hydraulic cylinder for fine balance adjustment 7 Platform for both dynamic and static experiments 9 Scale model of experimental sample 10 Back plate 11 Seating deck 12 Platform for static experiments 14 Balance weight 16 Support frame

Claims (4)

  A motion that is supported by a vertical rotating shaft that is rotationally driven by power, and swings between the horizontal beams on one end side of a rotating arm that is composed of a pair of horizontal beams facing both sides of the rotating shaft. Both the static and static experimental platforms are installed, and the bottom of the outer surface of both the dynamic and static experimental platforms swung up horizontally by centrifugal force is seated to vibrate due to the reaction force during sample excitation. A back plate for preventing static electricity and a platform for static experiments without a back plate mechanism swingably suspended between the pair of horizontal beams on the other end of the rotating arm, and the static beam of the pair of horizontal beams Balance weights are provided outside the platform suspension position for the special experiment, and each balance weight is moved outward from the outer surface of each corresponding horizontal beam. Out, centrifugal force loading apparatus to which the central axis is characterized by being configured to support the frame body located on the straight line connecting the rotation center and the center of the balance weight.   The centrifugal force loading device according to claim 1, wherein the balance weight has a weight adjustable structure in which a plurality of balance weights are stacked through a pin at a central portion thereof.   The centrifugal force loading device according to claim 1 or 2, wherein the frame body that supports the balance weight can be expanded and contracted in an axial direction thereof.   4. The centrifugal force loading device according to claim 1, wherein the rotary arm has a balance fine adjustment function of horizontally moving a fixed amount horizontally toward one end side or the other end side around the rotation axis.

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