Dynamic vibration absorbing structure

Abstract

Provided is a dynamic vibration absorbing structure capable of improving the efficiency of tuning work, even when provided at a position unsuitable for tuning.　This dynamic vibration absorbing structure comprises a pair of support members that extend in a predetermined direction on a horizontal plane and that are spaced apart in a direction orthogonal thereto, and a dynamic vibration absorbing device supported so as to span the pair of support members. The dynamic vibration absorbing device is provided with a base member placed on placement surfaces of the pair of support members, an elastic member provided on the base member, a mass body provided on the elastic member such that the elastic member is held between the mass body and the base member, and an attachment means for attaching the mass body to the base member. The base member is placed on the placement surfaces of the pair of support members so as to be movable in a predetermined direction with respect to the pair of support members.

Description

Dynamic vibration absorption structure

[0001] The present invention relates to a dynamic vibration absorption structure.

[0002] Conventionally, for example, a vibration damping device described in Patent Document 1 has been known. The vibration damping device described in Patent Document 1 is for reducing the vibration of a predetermined frequency generated in a beam by resonating a mass member. Specifically, the vibration damping device includes a pair of L-shaped brackets attached to the opposing side surfaces of two beams arranged in parallel and spaced apart on the ceiling portion, four rubber mounts attached to each L-shaped bracket in two, and one mass member placed and fixed on the rubber mounts.

[0003] The L-shaped bracket has a mounting substrate attached to the side surface of the beam and a support substrate bent in a right angle direction from one end of the mounting substrate. The mounting substrate has an oval-shaped insertion hole through which a mounting screw screwed into the side surface of the beam is inserted. By moving the mounting screw within the insertion hole, the mounting position of the vibration damping device with respect to the beam can be adjusted.

[0004] The vibration damping device described in Patent Document 1 can effectively reduce the vibration of a preset frequency by the mass member and the rubber mounts. On the other hand, when the frequency of the vibration generated in the beam is different from the preset frequency, it is necessary to perform so-called tuning to change the weight of the mass member.

[0005] When performing tuning, it is necessary to attach and detach the mass member through an inspection port formed under the two beams and the space between the two beams. Since the position of the inspection port is restricted by the building layout and the like, for example, it may be set at a position unsuitable for tuning, such as directly below the vibration damping device.

[0006] When the inspection port is provided at a position unsuitable for tuning in this way, in the vibration damping device described in Patent Document 1, the L-shaped bracket (the entire vibration damping device) can be moved within the range where the insertion hole extends by loosening the mounting screw. However, since the range in which the entire vibration damping device can be moved is limited within the range where the insertion hole extends, it is difficult to move to a position where the tuning operation can be efficiently performed.

[0007] One might consider removing the mounting screws from the beam and moving the entire vibration damping device, but the vibration damping device described in Patent Document 1 is supported by the beam only by mounting screws. Therefore, if the mounting screws are removed, the worker would have to bear the weight of the vibration damping device, resulting in poor work efficiency.

[0008] Japanese Patent Publication No. 2006-161862

[0009] The object of the present invention is to provide a dynamic vibration-absorbing structure that can improve the efficiency of tuning work, even when it is installed in a location unsuitable for tuning.

[0010] A dynamic vibration-absorbing structure according to one aspect of the present invention comprises a pair of support members extending in a predetermined direction on a horizontal plane and spaced apart in an orthogonal direction perpendicular to the predetermined direction on a horizontal plane, and a dynamic vibration-absorbing device supported by the pair of support members so as to straddle the pair of support members. The dynamic vibration-absorbing device comprises a base member having a pair of mounting portions placed on a mounting surface extending in the predetermined direction on each of the pair of support members, and a connecting portion connecting the pair of mounting portions, an elastic member provided on the base member, a mass body provided on the elastic member so as to sandwich the elastic member between the base member and the elastic member, and mounting means for attaching the mass body to the base member in a state that can be switched between a restricting state that restricts movement in the predetermined direction and the orthogonal direction and allows movement in the vertical direction, and an allowable state that allows the removal of the mass body by movement in the predetermined direction. The base member is placed on the aforementioned mounting surface of the pair of support members in a state that it can move in the predetermined direction relative to the pair of support members.

[0011] As described above, the present invention provides a dynamic vibration-absorbing structure that can improve the efficiency of tuning work, even when it is installed in a position unsuitable for tuning.

[0012] This is a perspective view showing the schematic configuration of the main part of a building to which an embodiment of the present invention of the dynamic vibration absorption structure is applied. This is a diagram showing the dynamic vibration absorption structure as viewed from a predetermined direction. This is a cross-sectional view of the dynamic vibration absorption structure along the line III-III in Figure 2, showing the dynamic vibration absorption device as viewed from above. This is a cross-sectional view of the dynamic vibration absorption structure along the line IV-IV in Figure 2, showing the dynamic vibration absorption device as viewed from a perpendicular direction. This is a cross-sectional view of the dynamic vibration absorption structure along the line V-V in Figure 3. This is a plan view of the second layer of the mass body provided in the dynamic vibration absorption device of the dynamic vibration absorption structure. This is a plan view of the first layer of the mass body provided in the dynamic vibration absorption device of the dynamic vibration absorption structure. This is a cross-sectional view of the dynamic vibration absorption structure corresponding to Figure 5, showing the state in which the second layer of the mass body has been removed. This is a diagram showing the dynamic vibration absorption device as viewed from above, corresponding to Figure 3, showing the state in which the second layer of the mass body has been removed. This is a cross-sectional view of the dynamic vibration absorption structure corresponding to Figure 8, showing the state in which the upper layer of the first layer of the mass body has been removed. This is a cross-sectional view of the dynamic vibration absorption structure corresponding to Figure 8, showing the lower layer of the first layer of the mass body being removed.

[0013] Embodiments of the present invention will be described below with reference to the attached drawings. Note that the following embodiments are examples that embody the present invention and are not intended to limit the technical scope of the present invention.

[0014] Figure 1 is a perspective view showing the schematic configuration of the main part of a building to which a dynamic vibration-absorbing structure 1 according to an embodiment of the present invention is applied. The dynamic vibration-absorbing structure 1 is for reducing vibrations of a predetermined frequency that occur in a beam 100 that supports the ceiling panel 101 of the lower floor and the floor panel 102 of the upper floor in a multi-story building, for example. The dynamic vibration-absorbing structure 1 is placed in the space S between the ceiling panel 101 of the lower floor and the floor panel 102 of the upper floor. The ceiling panel 101 is provided with an inspection opening 101A for inspecting the space S. With the dynamic vibration-absorbing structure 1 placed in the space S, a tuning operation is performed by a worker through the inspection opening 101A to effectively reduce vibrations that occur in the beam 100 by the dynamic vibration-absorbing structure 1 according to the frequency of vibrations of the beam 100.

[0015] The dynamic vibration absorption structure 1 will be described in detail with reference to Figures 2 to 11. The dynamic vibration absorption structure 1 comprises a pair of support members 2 extending in a predetermined direction D1 on a horizontal plane and spaced apart in an orthogonal direction D2 perpendicular to the predetermined direction D1 on a horizontal plane, and a dynamic vibration absorption device 3 supported by the pair of support members 2 so as to straddle the pair of support members 2. In the following description, the directional relationships will be defined as the predetermined direction D1 and the orthogonal direction D2, respectively, where each direction is orthogonal to the other on a horizontal plane, and the vertical direction perpendicular to the predetermined direction D1 and the orthogonal direction D2 will be defined as the up and down direction D3.

[0016] The pair of support members 2 are fixed to the beam 100 of the building. For example, as shown in Figures 2 and 3, each of the pair of support members 2 is, for example, a member with a C-shaped cross-section. Specifically, each of the pair of support members 2 has a flat plate-shaped support body portion 21 that extends in a predetermined direction D1 and a vertical direction D3, a flat plate-shaped upper projection portion 22 that protrudes from the upper end of the support body portion 21 in a direction perpendicular to the dynamic vibration absorber 3 in a direction D2 and extends in the predetermined direction D1, and a flat plate-shaped lower projection portion 23 that protrudes from the lower end of the support body portion 21 in a direction perpendicular to the dynamic vibration absorber 3 in a direction D2 and extends in the predetermined direction D1. Each of the pair of support members 2 has a surface on the lower projection portion 23 that faces upward in the vertical direction D3 and extends in the predetermined direction D1, which serves as the mounting surface 231.

[0017] The dynamic vibration absorber 3, as shown in Figures 2 to 5, for example, comprises a base member 4 placed on the mounting surfaces 231 of a pair of support members 2 so as to straddle the pair of support members 2, an elastic member 5 provided on the base member 4, a mass body 6 provided on the elastic member 5, and mounting means 7 for attaching the mass body 6 to the base member 4.

[0018] The base member 4 is, for example, a rectangular flat plate-shaped member, as shown in Figures 3 and 9. The base member 4 is made of, for example, steel. The base member 4 has a pair of mounting portions 41 placed on a mounting surface 231 extending in a predetermined direction D1 in each of the pair of support members 2, and a connecting portion 42 connecting the pair of mounting portions 41. In the base member 4, the regions located at both ends in the orthogonal direction D2 become the pair of mounting portions 41, and the region located between the pair of mounting portions 41 in the orthogonal direction D2 becomes the connecting portion 42.

[0019] The base member 4 is placed on the mounting surface 231 of the pair of support members 2 in a state that it can move in a predetermined direction D1 relative to the pair of support members 2. When the pair of mounting portions 41 of the base member 4 are fixed to the lower protrusions 23 of the pair of support members 2 by base fixing bolts 82, the movement of the base member 4 along the mounting surface 231 is restricted, while when the base fixing bolts 82 are removed, it can move along the mounting surface 231 in a predetermined direction D1.

[0020] As shown in Figure 2, the elastic member 5 is fixed to the connection portion 42 of the base member 4 by an elastic fixing bolt 81. A mass body 6 is provided on this elastic member 5. The elastic member 5 is capable of elastic deformation in accordance with the relative vertical movement D3 of the mass body 6 with respect to the base member 4 which is placed on the mounting surface 231 of the pair of support members 2. The elastic member 5 is made of, for example, a spring member. The number and position of the elastic members 5 relative to the connection portion 42 of the base member 4 are not particularly limited as long as it is possible to keep the mass body 6 provided on the elastic member 5 in a horizontal position with respect to the base member 4. In this embodiment, for example, four elastic members 5 are fixed to the connection portion 42 of the base member 4.

[0021] The mass body 6 is made of, for example, steel. As shown in Figure 2, the mass body 6 is provided on the elastic member 5 so as to sandwich the elastic member 5 between itself and the base member 4. As shown in Figure 3, the mass body 6 is provided on the elastic member 5 so as to be located within the range of the connection portion 42 of the base member 4 in a plan view taken from the vertical direction D3.

[0022] In the dynamic vibration absorption structure 1, when a pair of support members 2 fixed to the beam 100 vibrates in response to the vibration of the beam 100, a mass body 6 supported by an elastic member 5 on a connection portion 42 of a base member 4 placed on the mounting surface 231 of the pair of support members 2 moves in the opposite direction based on inertial force to the vertical vibration D3 of the pair of support members 2, thereby suppressing the vibration of the beam 100 via the pair of support members 2.

[0023] The mounting means 7 attaches the mass body 6 to the base member 4 in a state that can be switched between a restricted state and a permissible state. Figure 5 shows the mounting means 7 in the restricted state, and Figures 8, 10, and 11 show the mounting means 7 in the permissible state. When the mass body 6 is attached to the base member 4 in the restricted state, the mounting means 7 restricts the movement of the mass body 6 in a predetermined direction D1 and a perpendicular direction D2, while allowing the movement of the mass body 6 in the vertical direction D3. When the mass body 6 is attached to the base member 4 in the permissible state, the mounting means 7 allows the removal of the mass body 6 by movement in the predetermined direction D1.

[0024] According to the dynamic vibration absorption structure 1 described above, by switching the mounting means 7 to a restricting state, when vibrations of a preset frequency occur in the pair of support members 2 in accordance with the vibration of the beam 100, the mass body 6 can be moved in the vertical direction D3 while restricting movement in the predetermined direction D1 and the orthogonal direction D2, thereby suppressing the vibrations. Furthermore, since the base member 4 is placed on the mounting surface 231 in a state that allows it to move in the predetermined direction D1 relative to the pair of support members 2, the base member 4, that is, the dynamic vibration absorption device 3, can be moved in the predetermined direction D1 to a position suitable for tuning when the mounting means 7 is switched to a restricting state.

[0025] The position suitable for tuning is a position where, when the frequency of vibrations generated in the pair of support members 2 in response to the vibration of the beam 100 differs from a frequency preset in the dynamic vibration absorber 3, the operator can efficiently perform tuning work to change the weight of the mass 6 through the inspection port 101A. When performing tuning work on the dynamic vibration absorber 3, the operator accesses the dynamic vibration absorber structure 1 through the inspection port 101A and releases the base member 4 from the pair of support members 2 by removing the base fixing bolts 82. The operator can then move the dynamic vibration absorber 3 in a predetermined direction D1 to a position suitable for tuning by moving the base member 4 along the mounting surface 231 of the pair of support members 2. In this state, with the dynamic vibration absorber 3 moved to a position suitable for tuning, the mass 6 can be moved in a predetermined direction D1 relative to the base member 4 by switching the mounting means 7 to an allowable state, and for example, the mass 6 can be removed. Therefore, the dynamic vibration absorption structure 1 allows the entire dynamic vibration absorption device 3 to be moved in a predetermined direction D1 to a position suitable for tuning, and also allows the weight of the mass body 6 to be changed for the dynamic vibration absorption device 3 in a position suitable for tuning. Thus, even if the dynamic vibration absorption structure 1 is installed in a position unsuitable for tuning, the efficiency of the tuning process can be improved.

[0026] After the tuning work is completed, the operator can move the dynamic vibration absorber 3 back to its original predetermined position in the predetermined direction D1 by switching the mounting means 7 to the restricted state and then moving the base member 4 along the mounting surface 231 of the pair of support members 2. After that, the operator fixes the base member 4 to the pair of support members 2 with base fixing bolts 82.

[0027] In the dynamic vibration absorber 3, the mass body 6 may have, for example, a first layer 61 and a second layer 62 stacked on the first layer 61, as shown in Figures 2 and 4. In the mass body 6, the first layer 61 and the second layer 62 are made of, for example, rectangular flat steel material. The number of the first layer 61 and the second layer 62 is not particularly limited and may be one or more. In this embodiment, the mass body 6 has, for example, two first layers 61 and two second layers 62.

[0028] The mounting means 7 includes a restraining mechanism 71, as shown in Figures 5, 8, 10, and 11, for example. The number of restraining mechanisms 71 is not particularly limited and may be one or more. In this embodiment, as shown in Figure 2, for example, the mounting means 7 includes two restraining mechanisms 71 spaced apart from each other in an orthogonal direction D2. The restraining mechanism 71 is switchable between a restrained state in which the second layer 62 is restrained to the first layer 61 (the state shown in Figure 5) and a detachable state in which the second layer 62 is allowed to move in a predetermined direction D1 relative to the first layer 61 so that the second layer 62 can be removed from the first layer 61 (the state shown in Figures 8, 10, and 11). By switching the restraining mechanism 71 to the restrained state, the mounting means 7 can be switched to the above-mentioned restrictive state. Furthermore, by switching the restraint mechanism 71 to the detached state, the mounting means 7 can be switched to the above-mentioned permissible state.

[0029] By switching the restraint mechanism 71 to the restrained state, when vibration occurs in the pair of support members 2, the mass body 6 can be moved vertically D3 while restraining the second layer 62 with respect to the first layer 61, thereby suppressing the vibration. Furthermore, if tuning work is required for the dynamic vibration absorber 3, the base member 4 can be moved along the mounting surface 231 of the pair of support members 2 with the restraint mechanism 71 switched to the restrained state, thereby moving the dynamic vibration absorber 3 in a predetermined direction D1 to a position suitable for tuning. In this state, with the dynamic vibration absorber 3 moved to a position suitable for tuning, the second layer 62 can be removed from the first layer 61 of the mass body 6 by switching the restraint mechanism 71 to the detached state. Here, since the second layer 62 is stacked on top of the first layer 61, the second layer 62 can be removed from the first layer 61 by moving the second layer 62 in a predetermined direction D1 while its weight is supported by the first layer 61. Therefore, compared to the case where the worker bears the weight of the second layer 62 while removing the second layer 62, the efficiency of the tuning work can be improved.

[0030] Furthermore, in the dynamic vibration absorber 3, the mass body 6 may have a support layer 63 attached to the elastic member 5 between the first layer 61 and the elastic member 5. In the mass body 6, the support layer 63 is a layer that supports the first layer 61 and the second layer 62 from below while attached to the elastic member 5, and is made of, for example, a rectangular flat steel plate. The number of support layers 63 is not particularly limited and may be one or more. In this embodiment, the mass body 6 has, for example, three support layers 63.

[0031] In the mounting means 7, the restraint mechanism 71 may have a restraint shaft 711 and a clamping portion 712. In the restraint mechanism 71, the restraint shaft 711 is made up of, for example, a bolt, and the clamping portion 712 is made up of, for example, a nut. The restraint shaft 711 is a shaft that extends from the support layer 63 to above the second layer 62 so as to penetrate the second layer 62 and the first layer 61 with respect to the mass body 6. The clamping portion 712 is provided on the restraint shaft 711 in a state in which it is relatively displaceable in the vertical direction D3 with respect to the support layer 63, between a close state (shown in Figure 5) in which it is close to the support layer 63 so as to clamp the second layer 62 and the first layer 61 in the vertical direction D3 with respect to the support layer 63, and a separated state (shown in Figures 8, 10, and 11) which is further above the support layer 63 than the close state. By providing the clamping portion 712 on the restraint shaft 711 in the close state, it is possible to switch the restraint mechanism 71 to the above restraint state. Furthermore, by providing the clamping portion 712 on the restraining shaft 711 in a separated state, it becomes possible to switch the restraining mechanism 71 to the above-mentioned detached state.

[0032] If the restraint mechanism 71 has a restraint shaft 711 and a clamping portion 712, the second layer 62 in the mass body 6 may have, as shown in Figure 6, a second insertion portion 62A through which the restraint shaft 711 is inserted, and a second extension portion 62B that extends from the second insertion portion 62A to the edge of the second layer 62 in the predetermined direction D1, allowing the restraint shaft 711 to be guided from the second insertion portion 62A to a position on one side of the second layer 62 in the predetermined direction D1. In the example in Figure 6, the second layer 62 has two second insertion portions 62A and two second extension portions 62B, corresponding to each of the two restraint mechanisms 71 that are spaced apart from each other in the orthogonal direction D2.

[0033] In the mass body 6, the first layer 61 may have, as shown in Figure 7, a first insertion portion 61A through which the restraint shaft 711 is inserted, and a first extension portion 61B that extends from the first insertion portion 61A to the edge of the first layer 61 in the orthogonal direction D2, allowing the restraint shaft 711 to be guided from the first insertion portion 61A to a position on one side of the first layer 61 in the orthogonal direction D2. In the example of Figure 7, the first layer 61 has two first insertion portions 61A and two first extension portions 61B, corresponding to each of the two restraint mechanisms 71 that are spaced apart from each other in the orthogonal direction D2.

[0034] As shown in Figure 5, in the restraint mechanism 71, the clamping portion 712 is provided on the restraint shaft 711 in close proximity, so that the clamping portion 712 clamps the second layer 62 and the first layer 61 in the vertical direction D3 between the support layer 63 attached to the elastic member 5 and the clamping portion 712. As a result, when vibration occurs in the pair of support members 2, the mass body 6 can be moved in the vertical direction D3 while the second layer 62 and the first layer 61 are clamped against the support layer 63, thereby suppressing the vibration.

[0035] Furthermore, if tuning of the dynamic vibration absorber 3 is required, the dynamic vibration absorber 3 can be moved in a predetermined direction D1 to a position suitable for tuning by moving the base member 4 along the mounting surface 231 of the pair of support members 2 while the clamping portion 712 is positioned close to the restraining shaft 711. In this state, with the dynamic vibration absorber 3 moved to a position suitable for tuning, and with the clamping portion 712 positioned spaced apart on the restraining shaft 711 as shown in Figure 8, the second layer 62 can be moved from the first layer 61 in a predetermined direction D1 by guiding the restraining shaft 711 along the second extension portion 62B from the second insertion portion 62A. This allows the second layer 62 to be removed from the first layer 61 in the mass body 6.

[0036] Furthermore, after removing the second layer 62 from the first layer 61 while the clamping portion 712 is positioned apart on the restraint shaft 711, as shown in Figures 10 and 11, the restraint shaft 711 can be removed from the first layer 61 by moving the first layer 61 in a direction D2 perpendicular to the restraint shaft 711 from the first insertion portion 61A along the first extension portion 61B, thereby removing the first layer 61 from the restraint shaft 711. Here, since the removal direction of the second layer 62 is a predetermined direction D1, while the removal direction of the first layer 61 is a direction D2 perpendicular to the predetermined direction D1, it is possible to suppress the movement of the first layer 61 together with the second layer 62 when the second layer 62 is removed.

[0037] Furthermore, as shown in Figures 6 and 7, the length L1 of the first extension portion 61B in the first layer 61 in the orthogonal direction D2 is shorter than the length L2 of the second extension portion 62B in the second layer 62 in the predetermined direction D1. In the dynamic vibration absorption structure 1, as previously described, the base member 4 is movable in the predetermined direction D1 relative to the pair of support members 2, so when tuning the dynamic vibration absorption device 3, it is easier to secure a larger working space in the predetermined direction D1 than in the orthogonal direction D2. Under these circumstances, the length L1 of the first extension portion 61B in the first layer 61 in the orthogonal direction D2 is shorter than the length L2 of the second extension portion 62B in the second layer 62 in the predetermined direction D1, that is, the distance for removing the first layer 61 from the restraint shaft 711 is shorter than the distance for removing the second layer 62 from the restraint shaft 711. Therefore, in the orthogonal direction D2, where the workspace is relatively limited, the distance the first layer 61 needs to travel to release the constraint on the first layer 61 by the constraint axis 711 can be shortened.

[0038] Furthermore, as shown in Figure 7, the first layer 61 in the mass body 6 may have a first basic piece 611 and a first adjacent piece 612 adjacent to the first basic piece 611 in a direction D2 perpendicular to it. In this case, the second layer 62 may have a size that can cover the first basic piece 611 and the first adjacent piece 612 from above, and may have a mass smaller than the combined mass of the first basic piece 611 and the first adjacent piece 612. Then, as shown in Figures 10 and 11, the restraining mechanism 71 attaches the first layer 61 to the base member 4 such that, in the detached state where the clamping portion 712 is separated and provided on the restraining shaft 711, the first adjacent piece 612 and the first basic piece 611 can be individually removed by removing the second layer 62.

[0039] In the mass body 6, the first layer 61, which has a greater mass than the second layer 62, is divided into two pieces, the first basic piece 611 and the first adjacent piece 612. Furthermore, when the restraint mechanism 71 is removed, the first basic piece 611 and the first adjacent piece 612 can be removed individually. This reduces the weight burden when removing the first layer 61 compared to removing the entire first layer 61 at once, thus making the tuning work more efficient.

[0040] Furthermore, as shown in Figures 2 to 4, for example, the mounting means 7 may include a pair of first restricting members 72 and a pair of first damping members 721. The pair of first restricting members 72 are attached to the base member 4 by restricting fixing bolts 83 on both sides of the support layer 63 in a predetermined direction D1 so as to restrict the movement of the support layer 63 of the mass body 6 in a predetermined direction D1. The pair of first restricting members 72 have, for example, first restricting bolts 72A extending in the predetermined direction D1. The first restricting bolts 72A are normally not in contact with the support layer 63 and only come into contact with the support layer 63 when the support layer 63 moves slightly in the predetermined direction D1. The pair of first restricting members 72 can restrict the movement of the support layer 63 of the mass body 6 in a predetermined direction D1 by the contact of the first restricting bolts 72A. The pair of first damping members 721 are sandwiched between the pair of first restricting members 72 and the support layer 63 and are members for damping vibrations of the mass body 6. The pair of first damping members 721 are in contact with the support layer 63. The pair of first damping members 721 are made of, for example, an elastically deformable rubber material.

[0041] The mounting means 7 includes a pair of first restricting members 72 and a pair of first damping members 721. This allows the mass body 6 to move vertically D3 in response to vibrations of the pair of support members 2, suppressing unintended vibrations of the mass body 6 in a predetermined direction D1, and more effectively suppressing vibrations generated in the pair of support members 2. Furthermore, since the first damping member 721 is provided between the support layer 63 and the first restricting member 72, which are attached and detached less frequently than the first layer 61 and the second layer 62 during tuning work on the dynamic vibration absorber 3, the above effects can be obtained while maintaining the workability of the tuning work.

[0042] The mounting means 7 may also include a pair of second restricting members 73 and a pair of second damping members 731. The pair of second restricting members 73 are attached to the base member 4 by restricting fixing bolts 83 on both sides of the support layer 63 in the direction D2 orthogonal to the support layer 63, so as to restrict the movement of the mass body 6 in the direction D2 orthogonal to the support layer 63. The pair of second restricting members 73 have, for example, second restricting bolts 73A extending in the direction D2 orthogonal to the support layer 63. The second restricting bolts 73A are normally not in contact with the support layer 63 and only come into contact with the support layer 63 when the support layer 63 moves slightly in the direction D2 orthogonal to the support layer 63. The pair of second restricting members 73 can restrict the movement of the mass body 6 in the direction D2 orthogonal to the support layer 63 by contact of the second restricting bolts 73A. The pair of second damping members 731 are sandwiched between the pair of second restricting members 73 and the support layer 63 and are members for damping vibrations of the mass body 6. The pair of second damping members 731 are in contact with the support layer 63. The pair of second damping members 731 are made of, for example, an elastically deformable rubber material.

[0043] The mounting means 7 includes a pair of second restricting members 73 and a pair of second damping members 731. This allows the mass body 6 to move in the vertical direction D3 in response to vibrations of the pair of support members 2, thereby suppressing unintended vibrations of the mass body 6 in the orthogonal direction D2, and also more effectively suppressing vibrations generated in the pair of support members 2.

[0044] Incidentally, by slightly tightening the first regulating bolts 72A of the pair of first regulating members 72 while they are in contact with the support layer 63, the movement of the mass body 6 in the vertical direction D3 can be restricted. Similarly, by slightly tightening the second regulating bolts 73A of the pair of second regulating members 73 while they are in contact with the support layer 63, the movement of the mass body 6 in the vertical direction D3 can be restricted. In this way, when the first regulating bolt 72A and the second regulating bolt 73A are in contact with the support layer 63 and the movement of the mass body 6 in the vertical direction D3 is restricted, the suppression effect of the vibration generated in the pair of support members 2 due to the movement of the mass body 6 in the vertical direction D3 can be turned off. In this case, by comparing the vibration of the pair of support members 2 when the first regulating bolt 72A and the second regulating bolt 73A are not in contact with the support layer 63 with the vibration of the pair of support members 2 when the first regulating bolt 72A and the second regulating bolt 73A are in contact with the support layer 63, the suppression effect of the vibration accompanying the movement of the mass body 6 in the vertical direction D3 can be grasped.

[0045] Further, when the first regulating bolt 72A and the second regulating bolt 73A are not in contact with the support layer 63 and the movement of the mass body 6 in the vertical direction D3 is not restricted, if the first layer 61 and the second layer 62 of the mass body 6 are removed, the mass body 6 becomes lighter and is more likely to move in the vertical direction D3, so there is a risk of excessive deformation occurring in the first damping member 721 and the second damping member 731. Therefore, in a state where the movement of the mass body 6 in the vertical direction D3 is restricted by bringing the first regulating bolt 72A and the second regulating bolt 73A into contact with the support layer 63, by attaching or detaching the dynamic vibration absorber 3 to / from the pair of support members 2 in a light state where the first layer 61 and the second layer 62 of the mass body 6 are removed, it is possible to suppress excessive deformation from occurring in the first damping member 721 and the second damping member 731.

[0046] Incidentally, the above-described specific embodiments mainly include inventions having the following configurations.

[0047] A dynamic vibration absorber structure according to an aspect of the present invention includes a pair of support members that extend in a predetermined direction on a horizontal plane and are spaced apart in a direction orthogonal to the predetermined direction on the horizontal plane, and a dynamic vibration absorber supported by the pair of support members so as to straddle the pair of support members. The dynamic vibration absorber includes a base member having a pair of mounting portions mounted on mounting surfaces extending in the predetermined direction on each of the pair of support members, and a connecting portion connecting the pair of mounting portions, an elastic member provided on the base member, a mass body provided on the elastic member so as to sandwich the elastic member between the mass body and the base member, and attachment means for attaching the mass body to the base member in a state that is switchable between a restricted state that restricts movement in the predetermined direction and the orthogonal direction and allows movement in the vertical direction, and an allowable state that allows removal of the mass body by movement in the predetermined direction. The base member is mounted on the mounting surfaces of the pair of support members in a state that is movable in the predetermined direction with respect to the pair of support members.

[0048] According to the dynamic vibration absorber structure, by switching the attachment means to the restricted state, when vibrations of a preset frequency occur in the support members, the mass body can be moved in the vertical direction, so that the vibrations can be suppressed. Further, since the base member is mounted on the mounting surface in a state that is movable in the predetermined direction with respect to the pair of support members, the base member, that is, the dynamic vibration absorber can be moved in the predetermined direction to a position suitable for tuning in a state where the attachment means is switched to the restricted state. Thus, in a state where the dynamic vibration absorber is moved to a position suitable for tuning, by switching the attachment means to the allowable state, the mass body can be moved in the predetermined direction with respect to the base member, for example, the mass body can be removed. Therefore, according to the dynamic vibration absorber structure, the position of the entire dynamic vibration absorber can be moved in the predetermined direction to a position suitable for tuning, and the weight of the mass body can be changed with respect to the dynamic vibration absorber at a position suitable for tuning. Therefore, even when the structure is provided at a position unsuitable for tuning, the tuning work efficiency can be improved.

[0049] In the dynamic vibration-absorbing structure, the mass body may have a first layer and a second layer laminated on the first layer. The mounting means may include a restraining mechanism that can switch between a restraining state in which the second layer is restrained relative to the first layer and a detachment state in which movement in the predetermined direction relative to the first layer is permitted so that the second layer can be removed from the first layer.

[0050] According to the dynamic vibration absorption structure, the second layer can be removed from the first layer by switching the restraint mechanism to a detached state. Here, since the second layer is stacked on the first layer, the second layer can be moved in a predetermined direction while its weight is supported by the first layer, thereby removing it from the first layer. Therefore, the efficiency of the tuning work can be improved compared to the case where the worker bears the weight of the second layer while removing it.

[0051] In the dynamic vibration absorption structure, the mass body may have a support layer attached to the elastic member between the first layer and the elastic member. In this case, the restraint mechanism may have a restraint shaft extending from the support layer to above the second layer so as to penetrate the second layer and the first layer, and a clamping portion provided on the restraint shaft in a state that is relatively displaceable in the vertical direction relative to the support layer between a close state, which is close to the support layer, and a separated state, which is further above the support layer than the close state, so as to clamp the second layer and the first layer in the vertical direction between the support layer and the restraint shaft. The second layer has a second insertion portion through which the restraint shaft is inserted, and a second extension portion extending from the second insertion portion to the edge of the second layer in the predetermined direction so as to allow guidance of the restraint shaft from the second insertion portion to a position on one side of the second layer in the predetermined direction.

[0052] According to the dynamic vibration absorption structure, when the clamping portion is separated from the support layer, the restraining shaft is guided in a predetermined direction from the second insertion portion along the second extension portion, thereby allowing the second layer to be moved in a predetermined direction from the first layer.

[0053] In the dynamic vibration absorption structure, the first layer may have a first insertion portion through which the restraint shaft is inserted, and a first extension portion extending from the first insertion portion to the orthogonal edge of the first layer so as to allow guidance of the restraint shaft from the first insertion portion to a position on one side of the first layer in the orthogonal direction.

[0054] According to the dynamic vibration absorption structure, after removing the second layer from the first layer in a separated state where the clamping portion is separated above the support layer, the restraining shaft can be removed from the first layer by moving the first layer in a direction perpendicular to the restraining shaft along the first insertion portion to the first extension portion, thereby removing the first layer from the restraining shaft. Here, since the removal direction of the second layer is in a predetermined direction, while the removal direction of the first layer is in a direction perpendicular to the predetermined direction, it is possible to suppress the movement of the first layer together with the second layer when removing the second layer.

[0055] In the dynamic vibration absorption structure, the length of the first extension in the orthogonal direction may be shorter than the length of the second extension in the predetermined direction.

[0056] According to the dynamic vibration absorption structure, since the base member is movable in a predetermined direction relative to a pair of support members, it is easier to secure a larger workspace in the predetermined direction than in the orthogonal direction during tuning work. Under these circumstances, the length of the first extension in the orthogonal direction is shorter than the length of the second extension in the predetermined direction, that is, the distance for removing the first layer from the constraint axis is shorter than the distance for removing the second layer from the constraint axis. Therefore, in the orthogonal direction where space is relatively limited, the distance the first layer needs to move to release its constraint by the constraint axis can be shortened.

[0057] In the dynamic vibration-absorbing structure, the first layer may have a first basic piece and a first adjacent piece adjacent to the first basic piece in the direction perpendicular to it. In this case, the second layer may have a size that can cover the first basic piece and the first adjacent piece from above, and a mass smaller than the combined mass of the first basic piece and the first adjacent piece. The restraining mechanism attaches the first layer to the base member such that, in the removed state, the first adjacent piece and the first basic piece can be individually removed by removing the second layer.

[0058] According to the dynamic vibration absorption structure, the first layer, which has a greater mass than the second layer, is divided into two pieces (a first basic piece and a first adjacent piece), and the first basic piece and the first adjacent piece can be removed individually when removed. Therefore, compared to removing the first layer as a whole at once, the weight burden when removing the first layer can be reduced, making the tuning work more efficient.

[0059] In the dynamic vibration absorption structure, the mounting means may include a pair of restricting members attached to the base member on both sides of the support layer in the predetermined direction so as to restrict the movement of the mass body in the support layer in the predetermined direction, and a pair of damping members sandwiched between the pair of restricting members and the support layer, respectively, for damping the vibration of the mass body.

[0060] According to the dynamic vibration absorption structure, because it has a restricting member and a damping member, it can suppress vibrations of the mass in an unintended direction (a predetermined direction) and can more effectively suppress vibrations generated in the support member. Furthermore, since the damping member is provided between the support layer and the restricting member, which are attached and detached less frequently than the first and second layers, the above effects can be obtained while maintaining the workability of the tuning work.

Claims

1. A dynamic vibration-absorbing structure comprising: a pair of support members extending in a predetermined direction on a horizontal plane and spaced apart in an orthogonal direction perpendicular to the predetermined direction on a horizontal plane; and a dynamic vibration-absorbing device supported by the pair of support members so as to straddle the pair of support members, wherein the dynamic vibration-absorbing device comprises: a base member having a pair of mounting portions placed on a mounting surface extending in the predetermined direction on each of the pair of support members, and a connecting portion connecting the pair of mounting portions; an elastic member provided on the base member; a mass body provided on the elastic member so as to sandwich the elastic member between itself and the base member; and mounting means for attaching the mass body to the base member in a state that is switchable between a restricting state that restricts movement in the predetermined direction and the orthogonal direction and allows movement in the vertical direction, and an allowable state that allows removal of the mass body by movement in the predetermined direction, wherein the base member is placed on the mounting surface of the pair of support members so as to be movable in the predetermined direction relative to the pair of support members.

2. The dynamic vibration-absorbing structure according to claim 1, wherein the mass body comprises a first layer and a second layer laminated on the first layer, and the mounting means includes a restraining mechanism that can switch between a restraining state in which the second layer is restrained with respect to the first layer and a detachment state in which movement in the predetermined direction relative to the first layer is permitted so as to allow the removal of the second layer from the first layer.

3. The dynamic vibration-absorbing structure according to claim 2, wherein the mass body has a support layer attached to the elastic member between the first layer and the elastic member, the restraint mechanism has a restraint shaft extending from the support layer to above the second layer so as to penetrate the second layer and the first layer, and a clamping portion provided on the restraint shaft in a state that is relatively displaceable in the vertical direction with respect to the support layer between a close state in which it is close to the support layer and a separated state which is further above the support layer than the close state so as to clamp the second layer and the first layer in the vertical direction between it and the support layer, and the second layer has a second insertion portion through which the restraint shaft is inserted, and a second extension portion extending from the second insertion portion to the edge of the second layer in the predetermined direction so as to allow guidance of the restraint shaft from the second insertion portion to a position on one side of the second layer in the predetermined direction.

4. The dynamic vibration-absorbing structure according to claim 3, wherein the first layer has a first insertion portion for inserting the restraint shaft, and a first extension portion extending from the first insertion portion to the orthogonal edge of the first layer so as to allow guidance of the restraint shaft from the first insertion portion to a position on one side of the first layer in the orthogonal direction.

5. The dynamic vibration-absorbing structure according to claim 4, wherein the length of the first extension in the orthogonal direction is shorter than the length of the second extension in the predetermined direction.

6. The dynamic vibration-absorbing structure according to any one of claims 2 to 5, wherein the first layer comprises a first basic piece and a first adjacent piece adjacent to the first basic piece in the direction perpendicular to it, the second layer is sized to cover the first basic piece and the first adjacent piece from above and has a mass smaller than the combined mass of the first basic piece and the first adjacent piece, and the restraining mechanism attaches the first layer to the base member such that, in the removed state, the first adjacent piece and the first basic piece can be individually removed by removing the second layer.

7. The dynamic vibration-absorbing structure according to any one of claims 3 to 6, wherein the mounting means comprises a pair of restricting members attached to the base member on both sides of the support layer in the predetermined direction so as to restrict the movement of the mass body on the support layer in the predetermined direction, and a pair of damping members sandwiched between the pair of restricting members and the support layer, respectively, for damping vibrations of the mass body.

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