JP7133947B2 - floating foundation - Google Patents

Description

The present invention relates to floating foundations such as anti-vibration floors.

For example, in a live house or concert hall, the vibrations caused by the vertical movement of the audience in time with the music will cause the surrounding buildings to shake, and the vibrations of equipment that produces vertical vibrations, such as rotary presses, will propagate to the surroundings. In some cases, the vibration force is transmitted to the surroundings, causing vibration problems.

Conventionally, floating foundations (including anti-vibration mounts and anti-vibration floors) that support a vibration source via spring members are known as techniques for coping with such vibration problems.

Here, as shown in FIGS. 8(a) and 8(b), in the floating foundation 1, when the reaction force transmitted to the ground G is reduced to about 1/10 of the excitation force, It is necessary to set a natural frequency that is about 1/3 to 1/5 of the vibration frequency.

On the other hand, there is no problem in setting this natural frequency if the frequency to be controlled is a high frequency of ten and several Hz to several tens of Hz. A soft floating foundation is required. For example, as shown in FIG. 8(b), the vibration caused by the vertical axis during a concert is about 2 to 4 Hz. A floating foundation of 57 Hz or less is required.

If a floating foundation with such a very low natural frequency is adopted, there is a risk of causing additional inconveniences such as excessive sinking due to the surcharge or soft movement of the floor that causes discomfort during walking.

In addition, it is possible to realize a floating foundation of 0.57 Hz or less by using a spring with high rigidity, but in this case, a large mass is required, and the floating foundation becomes large and expensive. Inconvenience such as enlargement occurs.

On the other hand, as shown in FIGS. 9(a) and 9(b), adding an inertia mass damper in parallel with the spring member that supports the floating foundation may reduce the natural frequency of the floating foundation too much. A technical method has been proposed and put into practical use that exhibits higher vibration isolation performance in the frequency band to be controlled without any vibration (see, for example, Patent Document 1).

A technical method (vibration isolation connection mechanism) that uses a rotational inertia mass to isolate vibrations of a controlled object has also been proposed as one that uses the same principle (see, for example, Patent Document 2).

The technique described above adjusts the frequency to be controlled (cutoff frequency) by setting the inertia mass value, and can obtain a high vibration reduction effect in the target frequency range.

Incidentally, since the controlled frequency is the natural frequency of the spring stiffness and the inertial mass of the floating foundation, the controlled frequency is f _{cnt. , and the} spring stiffness is k, the required inertia mass _md can be obtained by the following equation (1).

For example, as shown in FIG. 9(b), in a floating foundation with a natural frequency of 1.0 Hz, if you want to reduce vibration with a frequency ratio (= excitation frequency / natural frequency) of 2.5, By adding an inertial mass damper with an inertial mass ratio of 0.16, the response at the frequency ratio of 2.5 (2.5 Hz in this case) can be greatly reduced, and the response in the surrounding frequency range is also It becomes possible to reduce to about 1/10.

JP 2008-82541 A JP-A-09-177875

However, in the above-described conventional floating foundation disclosed in Patent Document 1 and Patent Document 2, the inertial mass is a value set in advance in the inertial mass damper. For this reason, it is difficult to change the frequency to be controlled after installation. There was a problem that sufficient vibration reduction performance could not be obtained.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a floating foundation in which the frequency to be controlled can be easily changed/adjusted even after installation, and which can effectively exhibit vibration reduction performance even when the excitation frequency fluctuates. for the purpose.

In order to achieve the above objects, the present invention provides the following means.

A floating foundation according to the present invention comprises a floating foundation body to be damped, a spring element, a damping element, and an inertia mass mechanism for supporting the floating foundation body, wherein the floating foundation body is and a vibration reduction characteristic variable mechanism that adjusts and controls the inertia mass value of the inertia mass mechanism according to an operation command of the control means that receives the detection result of the vibration detection means, The vibration reduction characteristic variable mechanism divides the oscillating weight into two pieces, forms female screw holes in one piece of the oscillating weight and the other piece of the oscillating weight, and has a position adjusting screw made of a male screw in the female screw hole. When the position adjusting screw is rotated in response to an operation command from the control means, the one oscillating weight piece and the other oscillating weight piece are moved away from and close to the rotating shaft at the same time and with the same amount of left and right displacement. The inertia mass value is adjusted by changing the rotation center distance of the oscillating weight.

According to the floating foundation of the present invention, the inertial mass value of the inertial mass mechanism, and consequently the frequency to be controlled, can be easily changed/adjusted even after installation. It becomes possible to impart vibration reduction performance.

It is a figure which shows the rotary inertia mass damper (inertial mass mechanism) of the floating base, and a vibration reduction characteristic variable mechanism which concern on one Embodiment of this invention. FIG. 5 is a diagram showing a rotary inertia mass damper (inertia mass mechanism) and a vibration reduction characteristic variable mechanism of a floating foundation according to another embodiment of the present invention; FIG. 5 is a diagram showing a rotary inertia mass damper (inertia mass mechanism) and a vibration reduction characteristic variable mechanism of a floating foundation according to another embodiment of the present invention; FIG. 5 is a diagram showing a rotary inertia mass damper (inertia mass mechanism) and a vibration reduction characteristic variable mechanism of a floating foundation according to another embodiment of the present invention; FIG. 5 is a diagram showing a rotary inertia mass damper (inertia mass mechanism) and a vibration reduction characteristic variable mechanism of a floating foundation according to another embodiment of the present invention; FIG. 5 is a diagram showing the relationship between the center-of-rotation distance and the rate of change of the inertial mass value; It is a figure which shows the relationship between an inertia mass ratio and the reaction force response magnification of a floating foundation. It is a figure which shows the conventional floating foundation. FIG. 3 shows a floating foundation with a rotating inertial mass damper (inertial mass mechanism). 1 is a diagram showing a conventional rotary inertia mass damper (inertia mass mechanism); FIG.

A floating foundation according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 7 (and FIGS. 9 and 10).

The floating foundation of this embodiment is a floating foundation using an inertial mass, and is equipped with a vibration reduction characteristic variable mechanism that can easily change the inertia mass value (vibration damping target frequency), resulting in more effective vibration reduction performance. It is configured so that it can demonstrate

Specifically, similar to the floating foundation shown in FIG. 9(a), the floating foundation A of this embodiment includes a floating foundation main body 1, a spring member (spring rigidity/spring element) 2, and damping (damping) such as an oil damper. Element) 3 and a rotational inertia mass damper (rotational inertia mass M/inertia mass mechanism) 4 are connected to and supported by the ground G (including the floor and the like).

Here, the conventional rotary inertia mass damper 4 provided on the floating foundation 1 of FIG. , an inertial mass device consisting of an oscillating weight 4e fixed to a ball nut 4b via a guide plate 4d, a connecting member 4f connected to the floating foundation main body 1, and a fixing housing 4c connected to the ground G.

In this rotational inertia mass damper 4, when relative displacement occurs at both ends of the damper (connecting member 4f, fixing housing 4c end), the ball screw 4a moves in the direction of the axis O1 and the ball nut 4b rotates. The rotation of the rotating weight 4e connected to the ball nut 4b generates an inertial resistance force, which reduces the vibration of the floating foundation main body 1 (object to be damped).

On the other hand, the inertial mass damper 4' of this embodiment, as shown in FIG. frequency) can be adjusted.

Specifically, in the inertial mass damper 4′ (vibration reduction characteristic variable mechanism 5) of the present embodiment, first, the oscillating weight 6 is divided into one (left) oscillating weight piece 6a and the other (right) oscillating weight piece 6b. Further, the one oscillating weight piece 6a and the other oscillating weight piece 6b are provided with a guide plate slide hole 7 and a female screw hole 8, respectively. In the vibration reduction characteristic variable mechanism 5 of the present embodiment, the male screws at both ends are screwed into the female screw holes 8 of one oscillating weight piece 6a and the other oscillating weight piece 6b, respectively, so that the axis O2 is connected to the ball screw 4a. and a position adjusting screw (left-right screw) 9 provided in a horizontal direction perpendicular to the axis O1 of the ball nut 4b. Attachment/detachment means 10 for fixing/releasing (detachment) the one oscillating weight piece 6a and the other oscillating weight piece 6b to/from the guide plate 4d automatically or by remote control at any horizontal position may be provided.

In the inertial mass damper 4′/vibration reduction characteristic variable mechanism 5 configured as described above, the position adjustment screw 9 is rotated around the axis O2 as shown in FIGS. When rotated in one direction and the other direction respectively, one oscillating weight piece 6a and the other oscillating weight piece 6b advance and retreat horizontally along the guide plate 4d at the same time and with the same amount of displacement (synchronously). One oscillating weight piece 6a and the other oscillating weight piece 6b can be freely moved to the left and right of the center of the axis O1 of the ball screw 4a and the ball nut 4b.

As a result, the inertia mass value (vibration target frequency) can be freely adjusted by changing the rotation center distance r of the oscillating weight 6 .

On the other hand, as shown in FIGS. 2 and 3, the vibration reduction characteristic variable mechanism 5 has one oscillating weight piece 6a and the other oscillating weight piece 6b connected by screwing two position adjusting screws 9 to each other. The adjustment screw 9 may be configured to move forward and backward in the horizontal direction when it rotates around the axis O2. Furthermore, in this case, the two position adjusting screws 9 each have, for example, a driven gear 11a of the spur gear 11 fixed in the center, and these driven gears 11a are coaxially connected to the rotating shaft of the stepping motor 12. is provided in mesh with the drive gear 11b. Further, the electric stepping motor 12 receives a pulse signal from a control means (controller) 13 that receives a detection result of vibration detection means (not shown) for detecting vibration (acceleration, etc.) of the floating foundation body 1, and the pulse signal is sent to the stepping motor 12. It is configured to be driven according to a signal.

In this vibration reduction characteristic variable mechanism 5, the stepping motor 12 is driven in accordance with the pulse signal sent from the control means 13 which receives the detection result of the vibration detection means for detecting the vibration of the floating foundation main body 1. The rotation angle and rotation speed of 11b and, in turn, the driven gear 11a can be accurately controlled, enabling fine positioning. Moreover, if the stepping motor 12 is energized, it has a holding force to hold the position when stopped.

When the stepping motor 12 is driven, the connected spur gear 11 rotates and the position adjustment screw 9 rotates, and the one oscillating weight piece 6a and the other oscillating weight piece 6b advance and retreat accurately according to the amount of rotation of the driven gear 11a. can be moved. At this time, by controlling the stepping motor 12, the amount of movement of the oscillating weight 6 (one oscillating weight piece 6a and the other oscillating weight piece 6b) can be controlled to move the oscillating weight to a position where a predetermined inertial mass is obtained. The position can be held by the holding force of the stepping motor 12 . Therefore, the attachment/detachment means 10 can be made unnecessary.

The stepping motor 12 is fixed to the guide plate 4d by a motor fixing jig 15, and the ball nut 4b, the guide plate 4d, the oscillating weight 6, and the stepping motor 12 are arranged to rotate integrally when the damper is operated. It is

Furthermore, as shown in FIG. 3, a slip ring 16 is preferably used to power the stepping motor 12 .

The slip ring 16 is a connector that transmits electric power and signals via a metal ring 16a and a brush 16b arranged on a rotating body (see, for example, Tosoku Co., Ltd. "Slip Ring"). As a result, unlike the case where the cable is directly connected to the stepping motor 12, the damper 4' is displaced in the axial direction, the oscillating weight rotates, and the cable is not entangled in the damper 4'.

Also, the ring 16a of the slip ring 16 may be fixed to the rotary shaft 4g connecting the ball nut 4b and the guide plate 4d, and the brush 16b may be fixed to the fixing housing 4c or the floor.

As shown in FIG. 4, wireless power feeding may be used to power the stepping motor 12 that rotates together with the oscillating weight 6 . In this case, the output unit 17a of the wireless power supply system 17 may be connected to the motor driver 18 and fixed to the floor or the like.

Also, the transmission section 17b of the wireless power supply system 17 is connected to, for example, the stepping motor 12 and fixed to a connection fitting 19 extending from the guide plate 4d of the damper 4'. Electricity can be supplied from the output section 17a to the transmission section 17b in a non-contact state, thereby driving the stepping motor 12. FIG. Further, if both the output part 17a and the transmission part 17b of the wireless power supply system 17 are arranged on the axis O1 of the ball screw 4a of the damper 4', the position does not change even if the oscillating weight 6 rotates. It is possible to supply power at all times, including In this case, the cable 20 is only connected to the output portion 17a fixed to the floor, which does not move even when the damper 4' is actuated, so that the cable 20 is not entangled with the damper 4'.

Furthermore, as shown in FIG. 5, for example, the vibration reduction characteristic variable mechanism 5 has racks 21 fixed to one oscillating weight piece 6a and the other oscillating weight piece 6b, respectively, and a pinion is mounted between the two racks 21. 22 may be meshed together. In this case, the stepping motor 12 is connected to the pinion 22, and when the stepping motor 12 is driven, the pinion 22 rotates, the rack 21 moves, and one oscillating weight piece 6a connected to the rack 21 and the other oscillating weight piece 6b are connected to the rack 21. move forward and backward along the guide plate 4d in the same manner as the vibration reduction characteristic variable mechanism 5 of the present embodiment.

Next, the operation and effect of the floating foundation A using the inertial mass damper 4' of the present embodiment, that is, changing the inertial mass value to change the control target frequency will be described.

The inertial mass _md of the inertial mass damper 4' (4) having the oscillating weight 6 (4e) can be calculated using, for example, the following equations (2) and (3).

Here, α is the displacement in the direction of the damper _axis per unit rotation angle (cm/rad), Ix is the moment of inertia of area of the oscillating weight, and A is the cross-sectional area of the oscillating weight.

FIG. 6 shows the relationship between the rotation center distance r and the change rate of the inertial mass value when it is assumed that the oscillating weight pieces 6a and 6b are semicircular with a radius of 100 mm. In this figure, the rate of change of the inertial mass is expressed as a ratio with respect to the inertial mass value when the rotation center distance r=50 mm. Further, as shown in this figure, when the rotation center distance r is changed in the range of 30 to 80 mm, the inertial mass value changes by about 0.5 to 2.0 times.

Then, as shown in FIG. 7, in the floating foundation A with the natural frequency of 1.0 Hz, the inertia mass ratio is set to 0.07 to 0.25 (approximately 0.5 to 2.0 times based on 0.125). When varied, the frequency to be controlled can be varied from about 2.0 to 3.8 Hz.

As a result, it is said that the vibration frequency due to vertical movement in a concert hall is about 2 to 4 Hz, and it can be said that effective vibration reduction is possible in this frequency range in accordance with the melody.

Further, in the floating foundation A using the inertial mass damper 4' of the present embodiment, vibration detection means such as an accelerometer is installed on the floating foundation (floating foundation body 1) to measure vibration during excitation, By sending this detection result to the control means 13 to vary and control the frequency to be controlled, it is possible to immediately tune to the inertial mass value corresponding to the actually measured value.

In addition, since the inertial mass value can be easily adjusted automatically or remotely, it is possible to change the value while the vibration is actually occurring.

Therefore, according to the floating foundation A of the present embodiment, the actual vibration can be monitored, and the control target frequency can be adjusted to match the dominant frequency, and a high vibration reduction effect can be reliably obtained.

In addition, it is possible to perform fine vibration control, such as adjusting for differences in tunes at concerts.

Furthermore, since it can be adjusted automatically or remotely while vibration is occurring, it is possible to adjust the inertia mass value while measuring the actual dominant frequency, and obtain a reliable vibration reduction effect corresponding to the actual vibration. can be done. In addition, since the control means 13 can be provided at a location away from the damper installation position, for example, the inertia mass can be changed without going to the damper installation floor (floating foundation main body installation position).

Furthermore, even if the number of inertial mass dampers 4' is large, adjustment can be performed all at once (synchronously) by controlling the stepping motors 12, and highly reliable vibration reduction control can be performed.

Furthermore, electrical control does not require a complicated control program because it is a simple mechanism that only rotates gears driven by a motor.

Moreover, even if a problem occurs in the adjustment of the inertia mass value, the vibration reduction rate is low, but there is also the advantage that a certain vibration reduction effect can be obtained.

Furthermore, when used as the basis of machinery such as precision equipment and high-vibration equipment, it can immediately respond to changes in the vibration characteristics of the equipment.

Although one embodiment of the floating foundation according to the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the scope of the invention.

1 floating foundation body 2 spring element 3 damping element 4 conventional rotary inertia mass damper (inertia mass mechanism)
4' rotating inertial mass damper (inertial mass mechanism)
4a Ball screw 4b Ball nut 4c Fixing housing 4d Guide plate 4e Conventional oscillating weight 4f Connecting member 4g Rotating shaft 5 Vibration reduction characteristic variable mechanism 6 Oscillating weight 6a One oscillating weight piece 6b The other oscillating weight piece 7 Guide plate slide hole 8 Female screw hole 9 Position adjusting screw 10 Detaching means 11 Spur gear 11a Driven gear 11b Drive gear 12 Stepping motor 13 Control means 15 Motor fixing jig 16 Slip ring 16a Ring 16b Brush 17 Wireless power feeding system 17a Output part 17b Transmission part 18 Motor Driver 19 Connection hardware 20 Cable 21 Rack 22 Pinion A Floating base O1 Ball screw axis O2 Position adjustment screw axis

Claims (1)

A floating foundation comprising a floating foundation body to be damped, and a spring element, a damping element, and an inertia mass mechanism for supporting the floating foundation body,
vibration detection means for detecting vibration of the floating foundation body;
a vibration reduction characteristic variable mechanism that adjusts and controls the inertia mass value of the inertia mass mechanism according to an operation command of the control means that receives the detection result of the vibration detection means,
The vibration reduction characteristic variable mechanism includes:
The oscillating weight is divided into two pieces, one oscillating weight piece and the other oscillating weight piece are each formed with a female screw hole, and the female screw hole is provided with a position adjusting screw made of a male screw,
When the position adjusting screw is rotated in accordance with the operation command of the control means, the one oscillating weight piece and the other oscillating weight piece are moved away from and close to the rotating shaft at the same time and with the same amount of displacement on the left and right sides . A floating foundation characterized by adjusting the inertia mass value by changing the rotation center distance of a weight.

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