JP2007298067A - Dynamic damper and its adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damping device having simple construction for giving vibration damping effects to slight vibration such as environmental vibration in an easily adjustable manner, and to provide its adjusting method. <P>SOLUTION: The vibration damping deice A comprises a frame 1 to be fixed to a building, a weight 2 arranged movable relative to the frame, and a pair of springs 3 arranged between the frame and the weight in the directions perpendicular to the directions of adjusting the natural frequency of the weight and each having a tension adjusting means 4. The pair of springs 3 are arranged in the same horizontal plane and on one straight line, each having one end fixed to the weight via a mounting means 6 and the other end connected to the frame 1. The adjusting method comprises adjusting the natural frequency of the weight 2 by adjusting tension on the pair of springs 3 arranged between the frame 1 and the weight 2 in the directions perpendicular to the directions of adjusting the natural frequency as shown by arrowmarks a, b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention has a frequency of 2 Hz in a building such as a medium- and low-rise house, for example, a minute vibration due to a vehicle traveling around the building or a construction work performed around the building, a minute vibration due to walking in a house, or a minute vibration due to wind. The present invention relates to a dynamic damper of a building suitable for controlling a minute vibration (hereinafter referred to as “environmental vibration”) having a relatively short period of about 5 Hz and an adjustment method thereof.

  Conventionally, as a dynamic damper for suppressing environmental vibrations acting on a building, as shown in FIG. 6, a weight 53 is attached to a frame 51 fixed on the rooftop of the building via a spring 52 so as to be swingable. What has been proposed.

  In the above technique, since it is necessary to adjust the natural frequency of the weight 53 according to the natural frequency of each building, a plurality of weights 53 having different weights in advance and a plurality of springs 52 having different spring constants. The weight 53 is adjusted by adding or removing the weight 53, changing the spring constant of the spring 52 by changing the spring 52, or adjusting the number of the springs 52 to be attached. By finely adjusting the natural frequency to match the natural frequency of the building, environmental vibrations acting on the building are suppressed.

  On the other hand, in the invention described in Patent Document 1, a pair of coil springs is arranged between the frame and the weight so as to coincide with the direction in which the natural frequency of the weight is to be adjusted, and the coil spring is bent. Without increasing or decreasing the number of turns (increase or decrease the effective length of the coil spring), the spring constant is increased or decreased, thereby adjusting the spring constant of the spring to match the natural frequency of the building. is there.

  In the above technique, one end of the coil spring is fixed to the weight, and the other end is fitted into a groove provided on the outer periphery of the rod, and the rod is rotated with respect to the frame while being inserted / removed corresponding to the coil spring lead. Thus, the fitting length with respect to the rod can be adjusted without causing the coil spring to bend. That is, the spring constant can be adjusted by increasing / decreasing the number of turns accompanying the increase / decrease in the effective length of the coil spring.

JP 2001-254775 A "

  In the above conventional example, the weight 53 and the spring 52 must be individually replaced and adjusted, and it takes time to replace the weight 53 and the spring 52, so that the adjustment takes time and fine adjustment can be performed accurately. There was no problem. In order to perform fine adjustment, a large number of springs 52 having low rigidity must be prepared, and a plurality of weights 53 and springs 52 are transported to the roof of the building for adjustment. There is a problem that workability is poor because the spring 52 must be taken home.

  That is, in order to perform fine adjustment accurately, it is necessary to prepare an extremely large number of weights 53 and springs 52. Since continuous adjustment is impossible, strictly inaccurate adjustment can be performed.

  In the technique of Patent Document 1, the spring constant is adjusted by changing the effective number of turns of the coil spring, which is a direct and advantageous method. However, in order to directly change the number of turns of the coil spring arranged in the direction in which the natural frequency of the weight is to be adjusted, the rod and coil spring must be precisely interlocked in order to make fine adjustments at the final stage. The device becomes complicated.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to provide a dynamic damper having a simple structure and capable of exhibiting a damping action against minute vibrations such as environmental vibrations, and an adjustment method thereof easily. Is intended to provide.

  The dynamic damper adjusting method according to the present invention for solving the above-described problems is characterized in that a natural frequency of a dynamic damper having a frame fixed to a building and a weight disposed so as to be displaceable with respect to the frame in a specific direction. This is a dynamic damper adjustment method for adjusting the tension, and the tension acting on the pair of elastic members arranged between the frame and the weight is adjusted in a direction orthogonal to a specific direction in which the natural frequency is to be adjusted. By doing so, the natural frequency of the weight with respect to the specific direction is adjusted.

  The dynamic damper according to the present invention includes a frame fixed to a building, a weight arranged to be movable with respect to the frame, and a direction orthogonal to a direction in which the natural frequency of the weight is to be adjusted. And an elastic member having a pair of tension adjusting means arranged between the frame and the weight, and the pair of elastic members are arranged in a straight line on the same horizontal plane, and one end of each elastic member Is fixed to the weight via attachment means, and the other end of each elastic member is connected to the frame.

  In the dynamic damper, it is preferable that a plurality of pairs of elastic members are arranged in parallel, and one end of each elastic member is fixed to the weight via attachment means, and the other end is connected to the frame.

  In any of the above dynamic dampers, the direction in which the natural frequency of the weight is to be adjusted is two directions orthogonal to each other, and the direction in which the natural frequency of the weight is to be adjusted is orthogonal to each other. A pair of elastic members are arranged, and the pair of elastic members are arranged in a straight line and in a straight line, and one end of each elastic member is fixed to the weight via an attachment means, and each elastic member It is preferable to connect the other end to the frame.

  Furthermore, in any of the above dynamic dampers, the elastic member is preferably a coil spring.

  In the dynamic damper adjusting method of the present invention (hereinafter simply referred to as “adjusting method”), the natural frequency of the weight to be adjusted with respect to the weight displaceably disposed on the frame fixed to the building is specified. The natural frequency in a specific direction can be adjusted by arranging a pair of elastic members in a direction orthogonal to the direction of the direction and between the frame and the weight and adjusting the tension acting on the elastic members. it can.

  In this adjustment method, instead of changing the spring constant of the elastic member, the resistance to the force in the direction orthogonal to the tensile direction of the elastic member is changed by simply changing the tension to be applied. Since the natural frequency in the vibration direction of the orthogonal weights is adjusted without changing the natural frequency of the weight in the pulling direction of the elastic member, the subtle natural frequency can be easily adjusted.

  In the dynamic damper of the present invention, the weight is disposed so as to be movable with respect to the frame fixed to the building, and the direction of the natural frequency of the weight is perpendicular to the direction in which the weight is to be adjusted. An elastic member having a pair of tension adjusting means is disposed between the weights, and one end of each of these elastic members is connected to the weight and the other end is connected to the frame. The desired tension can be applied by operating the tension adjusting means. For this reason, the natural frequency of the weight in the direction to be adjusted can be easily adjusted.

  In particular, when a plurality of pairs of elastic members are arranged in parallel, it is possible to add adjustment capability by individual elastic members, and the range of adjustment of the natural frequency of the weight can be widened by a plurality of pairs of elastic members. .

  Further, the directions in which the natural frequency of the weight should be adjusted are two directions orthogonal to each other, and elastic members each having a pair of tension adjusting means are arranged in the two orthogonal directions, and one end of each of these elastic members is weighted. When the other end is connected to the frame, the tension adjusting means provided on each elastic member is operated so that the natural frequency of the weight in the pulling direction of the elastic member is not changed. The natural frequency in two orthogonal directions can be easily adjusted.

  Further, when the elastic member is a coil spring, the coil spring can freely move in a state where a tension is applied. For this reason, the coil spring arranged in the direction orthogonal to the moving direction along with the movement of the weight can easily follow the displacement in the orthogonal direction with respect to the direction in which the tension acts.

  Therefore, multiple types of dynamic dampers corresponding to the natural frequency of the building (for example, 2.0 Hz to 3.0 Hz, 2.8 Hz to 3.8 Hz, 3.6 Hz to 4.6 Hz,...) In a factory or the like in advance. By making it, it can be adjusted at the construction site after fixing the frame to the building.

  Hereinafter, a dynamic damper adjusting method according to the present invention and a dynamic damper most preferable for realizing the adjusting method will be described.

   The frame and weight of the dynamic damper referred to in the present invention are coupled through an elastic body such as a spring or laminated rubber. As a result, a vibration system is formed. If the spring constant such as a spring or laminated rubber acting on the weight changes, the natural frequency of the weight changes. Hereinafter, “the natural frequency of the weight” has the same meaning as “the natural frequency of the dynamic damper”.

  The dynamic damper adjusting method according to the present invention adjusts the natural frequency of the weight so that it matches the natural frequency of the building in a dynamic damper that mainly suppresses low frequency vibrations such as environmental vibrations acting on the building. Therefore, easy adjustment is realized by a simple operation.

  The dynamic damper according to the present invention has a function of mainly suppressing low-frequency vibrations such as environmental vibrations acting on steel structure middle- and low-rise buildings, and the action direction of vibrations to be suppressed and the moving direction of the weights are controlled. They are matched and placed on the roof of the building and fixed to the housing.

  The dynamic damper according to the present invention includes a frame fixed to a building, a weight connected to the frame via an elastic body and movably disposed, and orthogonal to a direction in which the weight is to be damped. And an elastic member having tension adjusting means for adjusting the tension arranged in the direction. Then, by appropriately adjusting the tension acting on the elastic member, the spring constant acting on the weight between the frame and the weight is changed, and as a result, the natural frequency of the weight is reduced to the natural frequency of the building. It is adjusted to match.

  In the dynamic damper, the weight is configured to be able to move in a direction in which vibration of the building should be suppressed. When adjusting the natural frequency of the weight so as to substantially match the natural frequency of the building, the spring constant of an elastic body such as a laminated rubber or a spring acting on the weight with respect to the moving direction of the weight is adjusted. Is done.

  As described in detail later, tension is applied to a pair of elastic members arranged in a direction orthogonal to the direction in which the natural frequency of the weight is to be adjusted (the moving direction of the weight) when stationary. When the weight moves (vibrates), that is, when the elastic body (in the case of a spring) bends (extends), the direction of the tension acting in the direction orthogonal to the moving direction of the weight is slightly inclined. The component force of tension accompanying this inclination acts as a reaction force on the weight and the elastic body. Therefore, the spring constant acting on the weight can be adjusted by adjusting the tension of the elastic member by the tension adjusting means. However, when there is no movement that suppresses vibration in the weight, that is, when the weight is stationary, the weight is not affected by the tension acting on the elastic member, and the stable weight is maintained. .

  That is, when the weight is moved in a direction to suppress the vibration due to the vibration acting on the building, the elastic member is stretched (displaced) and tilted along with the movement. That is, a force (reaction force) opposite to the moving direction according to the displacement amount and the inclination angle of the elastic member acts on the weight. Therefore, by adjusting the magnitude of the reaction force, it is possible to adjust the spring constant of the elastic body acting on the weight, and to adjust the natural frequency of the weight accordingly.

  The reaction force changes according to the tension acting on the elastic member when the weight is stationary and the moving amount of the weight. On the other hand, it is easy to adjust the tension acting on the elastic member.

  That is, when the weight is the same, when the tension applied to the elastic member is increased, a large reaction force can be applied in the moving direction of the weight along with the movement of the weight. When the tension applied to the weight is reduced, the reaction force acting with the movement of the weight can be reduced.

  In the present invention, the frame constituting the dynamic damper is fixed to the building, the weight is movably disposed, and the elastic member having the tension adjusting means disposed between the weights is connected. The structure and the shape are not limited as long as the function can be exhibited. That is, the frame is a structure for fixing a dynamic damper in a building to be installed, a structure for moving a weight, or a position and type of an elastic member connected to the weight, and tension adjusting means possessed by the elastic member. It is preferable to set appropriately according to the structure of the above. As such a frame, there are a frame-shaped frame and a frame formed simply by a flat plate.

  In the present invention, the shape and mass of the weight is not limited, the building conditions such as the planar shape and natural frequency of the target building, and the suppression conditions such as the natural frequency to be suppressed and its range, It is preferable to set as appropriate according to preset conditions such as.

  The weight is disposed so as to be movable with respect to the frame. The moving structure as a dynamic damper with respect to the weight frame is not particularly limited, and there is a structure that can move freely in one preset direction or a structure that can move freely in all directions. It is preferable to select and use it appropriately in accordance with a preset vibration control direction in the target building. For example, when the preset vibration suppression direction is one direction, the moving direction of the weight may be limited to only one direction matched with the vibration suppression direction, and the preset vibration suppression direction may be When the directions are two directions orthogonal to each other, the moving direction of the weight is preferably all directions within the same horizontal plane.

  The structure in which the weight can move with respect to the frame is not particularly limited, and as a structure that can move only horizontally in one direction, a pair of a rail and a wheel, a roller, a ball, and the like are used. It is possible to interpose an elastic spring or laminated rubber between the weight and the frame. As a structure that can move in all directions within the same horizontal plane, a laminated rubber is disposed between the weight and the bottom surface of the frame, a sphere is disposed between the weight and the bottom surface of the frame, There is a structure in which a weight is suspended from above and an elastic spring or laminated rubber is interposed between the weight and the frame, and any of them can be employed. When laminated rubber is disposed between the weight and the bottom surface of the frame, it is advantageous not only because the spring constant can be easily adjusted, but also because the weight can be supported.

  The moving direction of the weight configured to move in all directions within the same horizontal plane is defined by the mounting direction of the elastic body that is arranged between the weight and the frame and connects the two.

  The pair of elastic members disposed between the weight and the frame is preferably in the same horizontal plane and in a straight line. Thus, in the pair of elastic members arranged on the same horizontal plane and in a straight line, the tension acts on the straight line, and the eccentric force does not act on the weight, resulting in a complicated behavior. There is nothing.

  When multiple pairs of elastic members are arranged in parallel between the weight and the frame, the force applied to the weight by each elastic member increases, and as a result, the range of natural frequencies that can be adjusted is expanded. Is possible and preferable.

  Moreover, when suppressing the environmental vibration which acts on a building, there are a case where only one specific direction is targeted and a case where two orthogonal directions are targeted. Thus, when suppressing vibration in two orthogonal directions, an elastic member in two orthogonal directions is arranged between the weight and the frame, and the weight and the frame are connected by the respective elastic members. It is possible.

  When arranging elastic members in two orthogonal directions between the weight and the frame, there is no limitation on the pair of elastic members arranged in each direction, and a pair or a plurality of pairs of elastic members are arranged. It is possible to connect the weight and the frame.

  As described above, when a pair or a plurality of pairs of elastic members are arranged in parallel in two orthogonal directions, the pair or the plurality of pairs of elastic members arranged at least in the same direction are within the same horizontal plane and each pair is straight. It is preferable to arrange on a line.

  The elastic member has a large amount of deflection according to the magnitude of the applied tension, and can easily be inclined in a direction perpendicular to the direction in which the tension is applied (hereinafter also referred to as “axial direction”). Any structure or structure may be used. Examples of such an elastic member include rubber and a spring, and a coil spring is particularly preferable.

  In particular, as an elastic member, in order to increase the range of tension to be applied, the length in the initial state where no load is applied is short, and even when a large tension is applied, it is within the elastic limit. It is preferable.

  The attaching means attaches the elastic member to the weight, and any means having this function can be used. In particular, in the present invention, the tension is applied to the elastic member to adjust the natural frequency of the weight in the direction orthogonal to the direction of the action, and the performance depends on the attachment structure of the elastic member to the weight. There is no risk of change. For this reason, the attachment means can be utilized as long as it can simply attach one end of the elastic member to the weight.

  The tension adjusting means has a function of adjusting the tension acting on the elastic member, and can be used as long as it can exhibit this function. In particular, the tension adjusting means preferably has an optimum structure and shape corresponding to the structure and shape of the elastic member.

  Such tension adjusting means includes a hydraulic device including a hydraulic jack, a combination of a screw and a nut, and any of them can be preferably used. For example, in the case of a hydraulic jack, since the hydraulic jack is a reciprocating linear drive device, by operating the hydraulic pump portion, the elastic member is linearly pulled to apply tension, and the tensile force is adjusted, and the elastic force is adjusted. It is possible to adjust the tension acting on the member.

  When the tension adjusting means is a combination of a screw and a nut, the engaging portion of the elastic member provided at the end of the screw is configured to be rotatable and the nut is fixed to the frame, and the screw is attached to the nut. The elastic member is engaged with the engaging portion by screwing, and the tension is applied to the elastic member by rotating the screw in this state, and the tension acting on the elastic member is adjusted by adjusting the rotation of the screw. Is possible.

  The tension adjusting means does not always have to be interposed between the elastic member and the frame. After applying the tension necessary to achieve the object to the elastic member, the elastic member is directly connected to the frame. Alternatively, the connection may be made via a special connection member and then removed from between the elastic member and the frame. In this case, it is natural that it is necessary to attach the tension adjusting means every time it is necessary to readjust the natural frequency of the dynamic damper once installed in the building.

  Next, an example of a dynamic damper according to the present invention and an example of an adjusting method for adjusting the dynamic damper will be described with reference to the drawings. FIG. 1 is a diagram schematically illustrating the configuration of a dynamic damper. FIG. 2 is a schematic plan view for explaining the adjustment method. The dynamic damper A shown in FIG. 1 is configured such that the direction to be damped is set in one direction.

  In FIG. 1, a dynamic damper A includes a frame 1 fixed to a building frame (not shown), a weight 2 disposed on the frame 1, a pair of coil springs (springs) 3, and tension applied to the spring 3. The tension adjusting means 4 for adjusting and the laminated rubber 5 disposed between the lower surface 2a of the weight 2 and the bottom piece 1a of the frame 1 are configured.

  In the present embodiment, the frame 1 is formed in a box shape including a bottom piece 1a and standing pieces 1b and 1c provided around the bottom piece 1a. The bottom piece 1a is placed and fixed on a horizontal member typified by a beam constituting a steel frame in a building (not shown), and the upright pieces 1b and 1c are also fixed to corresponding members. However, it is not always necessary to fix all the pieces 1a to 1c to the casing, and the structure that fixes the bottom piece 1a or the standing pieces 1b and 1c to the casing on the condition that the dynamic damper A can exhibit a sufficient vibration damping function. It may be.

  The weight 2 is disposed inside the frame 1, and the laminated rubber 5 is interposed between the lower surface 2 a and the bottom surface 1 a of the frame 1, so that the weight 2 can move in all directions of the movable range of the laminated rubber 5. It has become. In this embodiment, the moving direction of the weight 2 is set to a straight line composed of the directions of arrows a and b.

  Further, a pair of attachment means 6 are provided at symmetrical positions on the upper surface 2 b of the weight 2 with the center on the plane as the center, and one end of the spring 3 is attached to the attachment means 6. The structure and shape of the attachment means 6 are not limited, and an optimum one is set corresponding to the end shape of the elastic member represented by the spring 3. In this embodiment, since the spring 3 acting on the tension is used, the bracket is fixed to the upper surface 2b of the weight 2 so that the end of the spring 3 can be hooked and attached. In addition, a hole is provided in the bracket.

  Each of the pair of springs 3 is configured as a tension spring, and is disposed in a direction orthogonal to the directions of arrows a and b, which are moving directions of the weight 2, and connects the weight 2 and the frame 1. That is, one end of the spring 3 is locked in a hole provided in the attachment means 6, and the other end is locked in tension adjusting means 4 provided in the standing piece 1 c of the frame 1. It is arranged between and connects the two. Accordingly, the pair of springs 3 are arranged in a direction orthogonal to the directions of the arrows a and b to connect the weight 2 and the frame 1.

  The pair of springs 3 are arranged on the same horizontal plane and in a straight line. That is, the pair of springs 3 are arranged in the same horizontal plane set at a position parallel to the bottom surface 1a of the frame 1 and separated from the bottom surface 1a, and further in the directions of arrows a and b which are the moving directions of the weight 2. They are arranged on a straight line in a direction orthogonal to the direction. For this reason, when tension is applied to the pair of springs 3, no couple is applied to the weight 2, and the weight 2 is kept stationary when no vibration is applied to the building. Is possible.

  The spring 3 has a preset wire diameter d and coil diameter D, the number of turns n, and a free length l. The spring 3 has a spring constant k set from these conditions. Therefore, the spring 3 generates a deflection δ (= t · k) corresponding to the acting tension t. In other words, the reaction force P corresponding to the deflection δ (= P · k) acts on the spring 3.

  The tension adjusting means 4 is disposed on each of the two upright pieces 1c constituting the frame 1 and adjusts so that a desired tension acts on the spring 3 disposed between the weight 2 and the frame 1. It is what has. In the present embodiment, the tension adjusting means 4 is configured by a screw mechanism in which nuts are respectively fixed to the standing upright pieces 1c and a screw rod is screwed onto the nuts. In this screw mechanism, the tip portion of the screw rod is configured to be rotatable, and for example, a locking hole for locking the end of the spring 3 is provided at the tip. Therefore, even if the screw rod is rotated in a state where the end of the spring 3 is locked to the tip of the screw rod, the rotation is not transmitted to the spring 3, and the magnitude of the tension can be simply adjusted.

  The laminated rubber 5 is disposed between the bottom surface 1 a of the frame 1 and the lower surface 2 a of the weight 2 and allows the weight 2 to move. This laminated rubber is constituted by alternately laminating a plurality of thin rubber plates and a plurality of thin steel plates. When the weight 2 is stationary, it transmits a load acting in the vertical direction to the frame 1 to In a state where the weight 2 is moving, the rubber plate is deformed and allowed to move in the horizontal direction.

  In the dynamic damper A configured as described above, by adjusting the tension acting on the spring 3 by the tension adjusting means 4, first, the spring constant acting on the weight is changed. As a result, the arrow of the weight 2 is changed. It is possible to adjust the natural frequency in the a and b directions.

  Next, a change in tension acting on the spring 3 and a change in reaction force acting on the weight 2 will be described with reference to FIG. FIG. 2A shows a case where the tension acting on the spring 3 is small, and FIG. 2B shows a state where the tension acting on the spring 3 is increased from FIG.

  FIG. 4A shows a state in which the initial length La is given to the spring 3 by generating a deflection δa by applying a tension ta to the spring 3, and the weight 2 is stationary. Show. FIG. 5B shows that the spring 3 is caused to generate a deflection δb larger than the deflection δa by applying a tension tb larger than the tension ta to the spring 3, so that the spring 3 has an initial larger than the initial length La. The state where the length Lb is given is shown, and the weight 2 is stationary in this state.

  Consider the case where the weight 2 has moved a distance d in the direction of arrow a from the state in which the weight 2 is stationary as described above. In FIG. 5A, the deflection of the spring 3 increases with the movement of the weight 2, changes to δad, the length increases to Lad, and the spring 3 is in the initial state according to the increased deflection δad. A tension tad greater than the tension ta acts. The spring 3 is inclined at an angle θa in the direction of arrow a from the initial posture. As a result, tad · sin θa, which is a component of the tension tad in the directions of arrows a and b, acts as a reaction force Pa on the weight 2. The reaction force Pa acts in the direction opposite to the moving direction of the weight 2.

  Similarly, in FIG. 5B, the deflection of the spring 3 increases with the movement of the weight 2, changes to δbd, the length increases to Lbd, and the spring 3 is in the initial state according to the increased deflection δbd. A tension tbd larger than the tension tb in the region acts. The spring 3 is inclined at an angle θb in the direction of arrow a from the initial posture. As a result, tbd · sin θb, which is a component of the tension tbd in the directions of arrows a and b, acts on the weight 2 as the reaction force Pb. The reaction force Pb acts in the opposite direction to the moving direction of the weight 2.

  As described above, the magnitude of the reaction force P acting on the weight 2 increases as the tension t acting on the spring 3 increases. That is, by adjusting the tension t acting on the spring 3, the reaction force acting on the weight 2 can be adjusted, and accordingly, the spring constant acting on the weight 2 can be adjusted. It becomes.

  Therefore, it is preferable that the spring 3 has a short free length when no tension is applied. The natural frequency of the weight 2 in the directions of the arrows a and b can be adjusted by operating the tension adjusting means 4 so that a desired tension is applied to the spring 3 as described above.

  Next, the configuration of the dynamic damper B according to the second embodiment will be described. FIG. 3 is a diagram schematically illustrating the configuration of the dynamic damper according to the second embodiment. In the figure, the same reference numerals are given to the same parts and parts having the same functions as those of the above-described embodiment, and the description thereof will be omitted (the same applies hereinafter).

  The dynamic damper B shown in FIG. 3 is configured such that the weight 2 can move only in the directions of the arrows a and b, is arranged in a direction orthogonal to the directions of the arrows a and b, and the weight 2 and the frame The natural frequency of the weight 2 in the directions of arrows a and b can be adjusted by a pair of springs 3 that connect to the weight 1.

  The spring 3 is attached via attachment means (not shown) provided on the side surface 2c of the weight 2 without using the attachment means 6 provided on the upper surface 2b of the weight 2 as in the above-described embodiment. . In this way, the portion of the weight 2 to which the spring 3 is attached is not limited, and a sufficient tension can be applied to the spring 3 to adjust the natural frequency of the weight 2. If it is good.

  A plurality of springs 10 are arranged on the weight 2 along the directions of arrows a and b, that is, the direction in which vibration should be suppressed. Each spring 10 has one end at the weight 2 and the other at the upright piece of the frame 1. Connected to 1b. The spring 10 has a function of roughly adjusting the natural frequency of the weight 2 in the directions of the arrows a and b, and one end is engaged with a locking piece 2d provided at the center of the lower surface 2a of the weight 2. The other end is locked to the standing piece 1 b of the frame 1.

  In the dynamic damper B configured as described above, the natural frequency of the weight 2 is roughly adjusted in advance by the spring constant of the spring 10. By adjusting the tension acting on the spring 3, the natural frequency in the directions of the arrows a and b is adjusted. It is possible to make adjustments.

  Next, the structure of the dynamic damper C according to the third embodiment will be described. FIG. 4 is a diagram illustrating the configuration of the dynamic damper according to the third embodiment.

  The dynamic damper C shown in FIG. 4 is configured so that vibration in two orthogonal directions can be suppressed by the weight 2. For this reason, the tension adjusting means 4 is provided on each of the standing pieces 1 b and 1 c of the frame 1, and each tension adjusting means 4 and the weight 2 are connected by the spring 3. Accordingly, the spring 3 is arranged in two orthogonal directions, and the natural frequency of the weight 2 in two orthogonal directions is adjusted by adjusting the tension acting on the spring 3 arranged in each direction. Is possible.

  Next, the configuration of the dynamic damper D according to the fourth embodiment will be described. FIG. 5 is a diagram illustrating the configuration of the dynamic damper according to the fourth embodiment.

  The dynamic damper D shown in the figure has two pairs of springs 3 arranged in two orthogonal directions. Even in the dynamic damper configured as described above, the natural frequency in the two orthogonal directions of the weight 2 is adjusted by operating the tension adjusting means 4 on each spring 3 to apply equal tension. Is possible.

  In particular, providing a plurality of pairs of springs 3 in parallel is preferable because the range of the natural frequency of the weight 2 that can be adjusted can be expanded.

  The dynamic damper adjusting method and the dynamic damper according to the present invention are capable of adjusting the natural frequency of the weight by a simple operation of simply adjusting the tension of the elastic member, and have a middle and low layer having a steel frame. It is advantageous for use in building vibration control.

It is a figure which illustrates the composition of a dynamic damper typically. It is a typical top view explaining an adjustment method. It is a figure which illustrates typically the composition of the dynamic damper concerning the 2nd example. It is a figure explaining the structure of the dynamic damper which concerns on 3rd Example. It is a figure explaining the structure of the dynamic damper which concerns on 4th Example. It is a figure which illustrates the structure of the conventional dynamic damper typically.

Explanation of symbols

AD Dynamic damper 1 Frame 2 Weight 3 Coil spring (spring)
4 Tension adjusting means 5 Laminated rubber 1a Bottom piece 1b, 1c Standing piece 2a Lower surface 2b Upper surface 2c Side surface 2d Projection piece 6 Mounting means 10 Spring

Claims (5)

A dynamic damper adjusting method for adjusting a natural frequency in a specific direction of a dynamic damper having a frame fixed to a building and a weight disposed so as to be displaceable with respect to the frame. The natural frequency of the weight in the specific direction is adjusted by adjusting the tension acting on the pair of elastic members arranged in a direction perpendicular to the specific direction and between the frame and the weight. Dynamic damper adjustment method characterized by the above. A frame fixed to a building, a weight arranged to be movable with respect to the frame, a direction orthogonal to a direction in which the natural frequency of the weight is to be adjusted, and between the frame and the weight An elastic member having a pair of tension adjusting means arranged, and the pair of elastic members are arranged on the same horizontal plane and in a straight line, and one end of each elastic member is attached to the weight via the attaching means. A dynamic damper characterized in that it is fixed and the other end of each elastic member is connected to a frame. A plurality of pairs of the elastic members are arranged in parallel, and each elastic member has one end fixed to the weight via the attaching means and the other end connected to the frame via the tension adjusting means. The dynamic damper according to claim 2. The direction in which the natural frequency of the weight is to be adjusted is two directions orthogonal to each other, a pair of elastic members are arranged in directions orthogonal to the direction in which the natural frequency of the weight is to be adjusted, and A pair of elastic members are arranged in the same horizontal plane and in a straight line, one end of each elastic member is fixed to the weight via an attaching means, and the other end of each elastic member is connected to the frame. The dynamic damper according to claim 2 or 3, characterized in that: The dynamic damper according to claim 2, wherein the elastic member is a coil spring.

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