JP2009138893A - Variable rigid spring, vibration control device and structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable rigid spring, a vibration control device and a structure producing small energy loss, and capable of controlling vibration of a vibrating body. <P>SOLUTION: This variable rigid spring 40 is composed of three installation units 42, 44 and 46 and a selective current-carrying unit 48. When detecting vibration, a control device 30 determines a proper spring constant for controlling the vibration, and operates the selective current-carrying unit 48. The selective current-carrying unit 48 carries an electric current by selecting at least one installation unit so that a spring constant of the variable rigid spring 40 becomes a desired spring constant. A coil spring becomes a solid state when a magnetic field acts on an MR fluid since the magnetic field is generated by current-carrying. Thus, displacement of the coil spring is checked, and the spring constant of the variable rigid spring 40 changes. Thus, the energy loss is reduced since a partial rigidity change is sufficient as compared with a conventional air spring for changing rigidity of the whole spring member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable stiffness spring, a vibration damping device, and a structure.

  Vibration occurs when a large number of spectators perform a jumping movement in concert with music in a live house or multipurpose hall, or when a press machine or the like continuously operates in a factory. This vibration propagates to buildings around the building via the foundation and the ground, induces vertical vibrations, and is felt as an unpleasant vibration. In order to eliminate this unpleasant vibration, there is an apparatus in which a vibration generating device that performs vibration suppression by forcibly generating a vibration that cancels the vibration is provided around a vibration generation source (for example, see Patent Document 1).

The vibration generator disclosed in Patent Document 1 performs vibration suppression by adjusting the internal pressure of the air spring and changing the natural frequency based on the vibration measured by the vibration sensor. However, the vibration generator of Patent Document 1 has a large energy loss because the internal pressure of the air spring is changed to change the rigidity of the entire air spring.
JP-A-6-200536

  An object of the present invention is to obtain a variable stiffness spring, a vibration damping device, and a structure that have a small energy loss and are capable of damping a vibrating body.

  A variable stiffness spring according to claim 1 of the present invention includes a plurality of spring members arranged in series, and a displacement prevention means provided on at least one of the plurality of spring members to prevent displacement of the spring member, It is characterized by having.

  According to the above configuration, the displacement preventing means prevents the displacement of at least one spring member among the plurality of spring members arranged in series, whereby the spring constants of the plurality of spring members as a whole change, that is, the rigidity. Can be changed. Thereby, as compared with the conventional one that changes the rigidity of the entire spring member, only a partial change in rigidity is required, so that energy loss is reduced. Further, by changing the stiffness of the variable stiffness spring according to the frequency of the vibrating body whose frequency changes, the vibration propagating from the vibrating body can be controlled.

  The variable stiffness spring according to claim 2 of the present invention is a housing in which the displacement prevention means is provided between an attachment member attached to each end of the spring member and between the pair of attachment members and contains MR fluid. And a projecting unit provided on the one attachment member and immersed in the MR fluid, and a magnetic field generating means for generating a magnetic field and applying the magnetic field to the MR fluid. It is characterized by having.

  According to the above configuration, the magnetic field generating means generates a magnetic field and causes the magnetic field to act on the MR fluid in the housing portion of the mounting unit. In the MR fluid in the housing portion, the magnetic field acts, and the contained granular magnetic bodies gather to form a cluster, so that the movement of the convex portion is prevented. Thereby, the attachment member in which the convex part was formed stops moving. For this reason, the displacement of the spring member attached to the attachment member that has stopped moving among the plurality of spring members is prevented, and the rigidity of the plurality of spring members as a whole changes. As described above, since the rigidity can be changed only by applying a magnetic field to the MR fluid, the rigidity of the variable rigidity spring can be easily changed. In addition, since the MR fluid instantaneously forms clusters due to the action of the magnetic field, the rigidity of the entire plurality of spring members can be changed in a short time.

  The variable stiffness spring according to claim 3 of the present invention is characterized in that the magnetic field generating means is a coil spring as the spring member, and the magnetic field is generated by energizing the coil spring. According to the above configuration, since the coil spring has both functions of the spring member and the magnetic field generating means, there is no need to separately provide the spring member and the magnetic field generating means, and the variable rigid spring can be downsized. Become.

  A variable stiffness spring according to a fourth aspect of the present invention includes a plurality of stacked mounting units, and magnetic field selection generation means for selectively energizing the coil spring to generate a magnetic field. .

  According to the above configuration, the magnetic field selection generation unit selects and energizes at least one coil spring that requires a change in rigidity among the coil springs of the plurality of stacked mounting units, and generates a magnetic field. When this magnetic field acts on the MR fluid in the housing portion, the displacement of the coil spring of the selected mounting unit is prevented, and the rigidity of the entire plurality of coil springs changes. Here, since the rigidity of the whole of the plurality of coil springs, that is, the rigidity of the variable rigidity spring can be changed into a plurality of types only by changing the combination of selection of the coil springs, the degree of freedom in changing the rigidity of the variable rigidity spring can be increased. Increase.

  The variable stiffness spring according to claim 5 of the present invention is characterized in that spring constants of the plurality of spring members are different from each other. According to the above configuration, it is possible to set more spring constants as a whole by combining different spring constants of the plurality of spring members.

  The vibration damping device according to claim 6 of the present invention is provided in a structure, provided in a measuring means for measuring the frequency and amplitude of the structure generated in the vertical direction, and in a pillar or a pile of the structure, Damping means for generating a damping force in the vertical direction that cancels vibrations of the structure, and control means for controlling the magnitude of the damping force based on the frequency and amplitude of the structure measured by the measuring means And the vibration damping means is provided between the vibration portion that can vibrate in the vertical direction, and between the vibration portion and the column or the pile. And the control means vibrates the excitation unit based on the amplitude and changes the stiffness of the variable stiffness spring based on the frequency. It is characterized by letting.

  According to the above configuration, when canceling (vibrating) the vibration of the structure, the amplitude is adjusted by the vibration of the excitation unit, and the frequency is adjusted by changing the rigidity of the variable stiffness spring. The magnitude of damping force can be controlled with a simple configuration. Moreover, the energy loss of a damping device can be made small by using a variable rigidity spring.

  A structure according to claim 7 of the present invention is characterized in that the vibration damping device according to claim 6 is provided on a column or a pile. According to the above configuration, when vertical vibrations are generated in the structure, such as when a person jumps in a group, the vibration damping device applies a vibration damping force to the column or pile based on the vertical vibration frequency and amplitude. . As a result, the vibration is not transmitted to the surrounding structures through the ground because the vibrations are canceled by the pillars and piles where the vibrations in the vertical direction of the structure as the vibration generation source concentrate.

  Since the present invention has the above configuration, the energy loss is small and the vibration body can be controlled.

  A variable rigid spring, a vibration damping device, and a structure according to a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a building 10 is constructed on the ground 20. The building 10 is constructed by forming a pile 12 made of concrete or the like in the vertical direction of the ground 22 and assembling and fixing a plurality of columns 14 and a plurality of beams 16 made of H steel on the pile 12. . The building 10 has a hall 24 for accommodating a large number of people on the top floor. A vibration sensor 26 that measures the amplitude and frequency of vibration generated in the hall 24 is provided on the floor 18 of the hall 24.

  On the other hand, a vibration damping device 100 that generates vibration (arrow B) that cancels vibration (arrow A) generated at the floor 18 of the hole 24 is included in the central portion 14B of the plurality of pillars 14A immediately below the hole 24. . A control device 30 that controls the vibration of the vibration damping device 100 is provided on the lower floor of the hall 24 based on the amplitude and frequency of vibration measured by the vibration sensor 26. The control device 30 and the vibration sensor 26 are connected by a cable 28 that can be energized, and the control device 30 and the vibration damping device 100 are similarly connected by a cable 32 that can be energized. The control device 30 includes a power source (not shown) and can supply power from the control device 30 to the outside.

  As shown in FIG. 2A, a ceiling wall 104 and a bottom wall 106, which are made of steel plates and are spread in the horizontal direction, are welded between the flanges of the central portion 14B of the column 14A. Further, on both sides of the web of the central portion 14B, a storage portion 107A and a storage portion 107B are formed by being surrounded by the ceiling wall 104 and the bottom wall 106. The damping device 100 is housed in each of the housing portion 107A and the housing portion 107B. In addition, since the damping device 100 in the storage unit 107A and the storage unit 107B has the same configuration, the description of the damping device 100 in the storage unit 107B is omitted.

  Next, the vibration damping device 100 will be described. As shown in FIGS. 2A and 2B, the vibration damping device 100 includes a vibration unit 108 that generates vibrations and a frequency generated by the vibration unit 108 to adjust the frequency of the ceiling wall 104 and the bottom. The vibration adjusting unit 110 is configured to transmit to the wall 106.

  The vibration unit 108 has two columns of channel steel 140 opposed to each other on the bottom plate 118 to form a gap 121, and two auxiliary columns 126 erected on both sides of the column 120. The movable portion 122 is inserted in the column 120 in a hollow cylindrical shape, and the top plate 116 is supported by the column 120 and the auxiliary column 126.

  The support column 120 is surrounded by the movable portion 122, and a support member 128 extending inward from the movable portion 122 is positioned in the gap portion 121 so as to be movable in the vertical direction. Further, a plurality of magnets 142 are fixed in a vertical direction on the inner side (web) of the channel steel 140 constituting the support column 120.

  In the center of the support member 128, an electromagnetic coil 130 is fixed, which is wound around a core metal (not shown), and is opposed to the magnet 142. Thereby, the electromagnetic coil 130 and the movable part 122 are integrated, and can move along the outer peripheral surface of the column 120. One end of a cable 132 that can be energized is connected to the electromagnetic coil 130. The other end of the cable 132 is connected to a power source (not shown), and control of energization to the cable 132 is controlled by the control device 30 (see FIG. 1).

  On the outer surface of the movable portion 122, a weight 124 made of a steel plate is fixed so as to be replaceable by fixing means such as a bolt and a nut (not shown). By changing the weight of the weight 124, the weight of the movable portion 122 can be changed.

  Here, when the electromagnetic coil 130 is energized in response to a command from the control device 30 (see FIG. 1), a magnetic field is generated around the electromagnetic coil 130 and is movable by the repulsive force between the magnetic field and the magnetic field of the magnet 142 described above. The part 122 moves along the column 120. The moving direction of the movable part 122 changes depending on the energization direction to the electromagnetic coil 130, and the movable part 122 moves in the vertical direction (arrow F direction) when the control device 30 appropriately changes the energization direction. . As the movable part 122 moves in the vertical direction, the vibration part 108 vibrates and a vibration force is generated.

  On the other hand, the vibration adjusting unit 110 includes a spring 112 having a predetermined spring constant (inherent rigidity) and a variable rigidity spring 40 whose spring constant (rigidity) is changed by energization from the control device 30 (see FIG. 1). ing. One end of the spring 112 and the variable stiffness spring 40 is fixed to the ceiling wall 104 or the bottom wall 106, and the other end is fixed to the top plate 116 or the bottom plate 118.

  Next, the variable stiffness spring 40 will be described. Here, the variable stiffness spring 40 disposed between the ceiling wall 104 and the top plate 116 will be described, but the variable stiffness spring 40 disposed between the bottom wall 106 and the bottom plate 118 has the same configuration. As shown in FIG. 3A, the variable stiffness spring 40 includes three attachment units 42, 44, 46 and a selective energization unit 48 provided in the control device 30 (see FIG. 1). .

  The attachment unit 42 has a substantially plate-like lower attachment member 54. On the upper surface of the lower mounting member 54, a substantially cylindrical storage case 58 having an opening formed in the upper portion is attached by adhesion or the like. In the storage case 58, an MR (Magneto-Rheological) fluid 56 made of silicon oil in which the granular magnetic material G is dispersed and mixed is stored.

  The MR fluid 56 is a fluid liquid in which the granular magnetic material G is dispersed in a normal time when the magnetic field M (magnetic field) is not acting, but is generated as shown in FIG. When the applied magnetic field M acts, the granular magnetic bodies G gather to form a cluster and become a solid having a yield stress. 3B shows the action state of the magnetic field M on the MR fluid 56 in the mounting unit 46, the same applies to the other mounting units 42 and 44. FIG.

  A metal coil spring 50 is extrapolated to the housing case 58, and the lower end of the coil spring 50 is fixed to the upper surface of the lower mounting member 54 by bonding or the like. Further, the upper end portion of the coil spring 50 is fixed to the lower surface of the substantially plate-like upper mounting member 52 disposed on the housing case 58 by bonding or the like. On the lower surface side of the upper mounting member 52, a convex portion 60 that is inserted into the opening of the housing case 58 and immersed in the MR fluid 56 is provided inside the coil spring 50.

  In this way, the upper mounting member 52 and the lower mounting member 54 that are respectively attached to both ends of the coil spring 50, and the storage case 58 that is provided between the upper mounting member 52 and the lower mounting member 54 and stores the MR fluid 56. The projection unit 60 provided in the upper mounting member 52 and immersed in the MR fluid 56 constitutes the mounting unit 42.

  Similarly, the attachment unit 44 accommodates the MR fluid 56 provided between the upper attachment member 64 and the lower attachment member 66 attached to both ends of the coil spring 62 and between the upper attachment member 64 and the lower attachment member 66. And the convex portion 70 provided in the upper mounting member 64 and immersed in the MR fluid 56.

  The mounting unit 46 also includes an upper mounting member 74 and a lower mounting member 76 that are respectively mounted at both ends of the coil spring 72, and a housing that accommodates the MR fluid 56 provided between the upper mounting member 74 and the lower mounting member 76. A case 78 and a convex portion 80 provided on the upper mounting member 74 and immersed in the MR fluid 56 are configured.

  Here, a projecting portion 54A having an outer diameter smaller than that of the convex portion 70 is formed downward from substantially the center of the lower surface of the lower mounting member 54, and the outer surface of the projecting portion 54A is disposed at the approximate center of the upper surface of the upper mounting member 64. A hole 64A having an inner diameter substantially equal to the diameter is formed. The mounting units 42 and 44 are stacked by fitting the protrusion 54A into the hole 64A.

  Similarly, a protrusion 66A having an outer diameter smaller than that of the convex portion 80 is formed downward from substantially the center of the lower surface of the lower mounting member 66, and the outer surface of the protrusion 66A is formed at the approximate center of the upper surface of the upper mounting member 74. A hole 74A having an inner diameter substantially equal to the diameter is formed. The mounting units 44 and 46 are stacked by fitting the protrusion 66A into the hole 74A.

  The upper attachment member 52 is attached to the ceiling wall 104 by fixing means by bonding or fastening such as bolts and nuts. The lower mounting member 54 and the upper mounting member 64, the lower mounting member 66 and the upper mounting member 74, and the lower mounting member 76 and the top plate 116 are fixed by the same fixing means. In this way, the three attachment units 42, 44 and 46 are stacked.

  Here, the spring constant of the coil spring 50 is K1, the spring constant of the coil spring 62 is K2, the spring constant of the coil spring 72 is K3, and the spring constant of the variable stiffness spring 40 is K. Further, as a simple model, the variable stiffness spring 40 has coil springs 50, 62, and 72 connected in series. At this time, 1 / K = 1 / K1 + 1 / K2 + 1 / K3. K1, K2, and K3 may be the same value or different values, but are different values here. This is because the number of patterns that can be set for the spring constant K of the variable stiffness spring 40 increases when the spring constants are set to different values.

  The upper end of the coil spring 50 is connected to one end of the cable 82A, and the lower end is connected to one end of the cable 82B. The other ends of the cable 82A and the cable 82B are connected to the selective energization unit 48. Similarly, the upper end of the coil spring 62 is connected to one end of the cable 84A, and the lower end is connected to one end of the cable 84B. The other ends of the cable 84A and the cable 84B are connected to the selective energization unit 48. Similarly, the upper end of the coil spring 72 is connected to one end of the cable 86A, and the lower end is connected to one end of the cable 86B. The other ends of the cable 86A and the cable 86B are connected to the selective energization unit 48.

  When the control device 30 selects the spring constant K of the variable stiffness spring 40 based on the vibration frequency measured by the vibration sensor 26 (see FIG. 1), the selection energization unit 48 is based on the selected spring constant K. At least one of the coil springs 50, 62, 72 is energized. On the other hand, when at least one of the coil springs 50, 62, 72 is energized, the spring constant K of the variable stiffness spring 40 changes. As a result, the stiffness of the variable stiffness spring 40 changes, the stiffness of the vibration adjustment unit 110 changes, and the frequency generated by the above-described excitation unit 108 (see FIG. 2) changes.

  Next, the operation of the first embodiment of the present invention will be described.

  As shown in FIGS. 1 and 2, when a concert or the like is performed in the hall 24 and a person jumps in a group in accordance with the rhythm of the music, the floor 18 of the building 10 vibrates in the vertical direction. The vibration wave A (amplitude a, period T1, frequency 1 / T1) generated in the floor 18 is concentrated and propagated on the column 14A. The vibration sensor 26 measures the amplitude a of the vibration wave A, the period T1, and the vibration frequency 1 / T1, and transmits data to the control device 30.

  Subsequently, the control device 30 energizes the electromagnetic coil 130 so as to generate the vibration of the vibration wave B (amplitude a, vibration frequency 1 / T1) that is shifted from the vibration wave A by ½ period to generate a magnetic field. Thus, the excitation unit 108 vibrates up and down. The vibration of the excitation unit 108 is adjusted in frequency by the rigidity (spring constant) of the vibration adjustment unit 110 including the spring 112 and the variable stiffness spring 40. It is assumed that the spring constant K of the variable stiffness spring 40 is set in accordance with the predicted frequency before the first music performance is performed.

  The vibration wave A propagated to the column 14A is generated by the excitation unit 108 and is canceled by the vibration suppression force of the vibration wave B whose frequency is adjusted by the vibration adjustment unit 110. Therefore, the vibration propagates downward from the central portion 14B. Is almost gone. When weak vibration is measured by the vibration sensor 26, the control device 30 adjusts the energization to the electromagnetic coil 130 and appropriately performs feedback control, so that the vibration wave A is suppressed.

  Next, vibration suppression when the vibration frequency and amplitude of the vibration wave in the hole 24 change will be described. As shown in FIGS. 1 and 5, in the hall 24, for example, a concert is performed, and a group of people jumps in time with the first song, and a vibration wave for canceling the vibration wave generated at that time is a graph C ( Amplitude b, period T2, frequency 1 / T2). Here, the first song is finished, the second song is started, and a group of people jumps to the song again, and the vibration wave of graph A (amplitude a, period T1, frequency 1 / T1) Suppose that occurs.

  Based on the data (amplitude a, period T1, frequency 1 / T1) transmitted from the vibration sensor 26, the control device 30 changes the energization amount and energization direction to the electromagnetic coil 130 (see FIG. 2b), The amplitude of the vibration wave of graph C is adjusted from b to a (arrow Y) while being shifted from the vibration wave of A by ½ period.

  Further, as shown in FIGS. 3, 4 (c), and 5, the control device 30 adjusts the frequency of the vibration wave of the graph C from 1 / T 2 to 1 / T 1 (arrow X), and therefore is variable. Of the mounting units 42, 44, 46 in the rigid spring 40, which mounting unit should be changed in rigidity is selected.

  This selection can be made, for example, without deleting or deleting any of the three terms on the right side of the relational expression 1 / K = 1 / K1 + 1 / K2 + 1 / K3 of the spring constant K of the variable stiffness spring 40 described above. The period T is calculated using this spring constant K, and when the obtained T is the closest value to T1, it can be performed depending on which attachment unit term is deleted. Here, it is assumed that the rigidity of the variable rigidity spring 40 is changed by changing the rigidity of the mounting unit 42. Assuming that the spring constant of the variable stiffness spring 40 after the change is K ′, 1 / K ′ = 1 / K2 + 1 / K3.

  By selecting the attachment unit 42, the control device 30 operates the selective energization unit 48 to energize the coil spring 50. In the coil spring 50, a magnetic field M is generated according to the energization amount from the selective energization unit 48 and the number of turns of the coil spring 50. When the magnetic field M acts on the MR fluid 56 inside the housing case 58, the granular magnetic bodies G form clusters and become solid. Thereby, the displacement of the convex portion 60 of the upper attachment member 52 is prevented, and the displacement of the coil spring 50 attached to the upper attachment member 52 and the lower attachment member 54 is prevented.

  Here, FIG. 4A shows a state where the displacement of the coil springs 50, 62, 72 is not blocked, and FIG. 4B shows a state where the displacement of the coil spring 50 is blocked. Yes. In FIG. 4A, since the displacement of the coil springs 50, 62, 72 is not prevented, the distances d1, d2, d3 between the mounting members are variable. On the other hand, in FIG. 4B, since only the displacement of the coil spring 50 is blocked, the distance d1 is fixed and the distances d2 and d3 are variable.

  As described above, since the spring constant of the variable stiffness spring 40 is changed to K ′, the stiffness of the vibration adjustment unit 110 is changed in FIGS. 2, 4 (c), and 5, and the vibration of the excitation unit 108 is changed. The number is adjusted. As a result, the vibration wave of graph B (amplitude a, frequency 1 / T1, delay of period T1 / 2) is generated in the excitation unit 108, and the vibration wave of graph A is generated by the damping force of the vibration wave of graph B. Be countered.

  As described above, the displacement of at least one coil spring among the plurality of coil springs 50, 62, 72 arranged in series by the mounting units 42, 44, 46 and the selective energization unit 48 as the displacement prevention means. By preventing this, the spring constants of the plurality of coil springs 50, 62, 72 as a whole can be changed, and the rigidity of the variable stiffness spring 40 can be changed. Thereby, as compared with the conventional air spring that changes the rigidity of the entire spring member, a partial change in rigidity is sufficient, and energy loss is reduced. Further, the vibration propagating from the hole 24 to the ground 22 can be suppressed by changing the rigidity of the variable stiffness spring 40 according to the frequency of the hole 24 (floor portion 18) where the frequency changes.

  Furthermore, since the rigidity of the variable rigidity spring 40 can be changed by simply applying the magnetic field M to the MR fluid 56, the rigidity of the variable rigidity spring 40 can be easily changed. Further, in the MR fluid 56, the granular magnetic bodies G form clusters instantly by the action of the magnetic field M, so that the rigidity of the variable stiffness spring 40 can be changed in a short time.

  Further, since the coil springs 50, 62, and 72 have both functions of the spring member and the magnetic field generating means constituting the variable stiffness spring 40, it is not necessary to separately provide the spring member and the magnetic field generating means, and the variable is variable. The rigid spring 40 can be downsized.

  In addition, since the rigidity of the whole of the plurality of coil springs 50, 62, 72, that is, the rigidity of the variable rigidity spring 40 can be changed into a plurality of types only by changing the combination of selection of each coil spring, The degree of freedom of rigidity change is improved.

  In addition, when the vibration damping device 100 cancels (vibrates) the vibration of the building 10, the amplitude is adjusted by the vibration of the excitation unit 108, and the frequency is adjusted by changing the rigidity of the variable stiffness spring 40. Therefore, the magnitude of the damping force can be controlled with a simple configuration. Further, by using the variable stiffness spring 40, the energy loss of the vibration damping device 100 can be reduced.

  In addition, when a vertical vibration occurs in the building 10 due to a person jumping in a group, the vibration damping device 100 applies a vibration damping force to the column 14 or the pile 12 based on the vertical vibration frequency and amplitude. Thereby, in the building 10 which is a vibration generation source, the vibration is canceled by the column 14 where the vibration in the vertical direction is concentrated, so that the vibration is not transmitted to the surrounding buildings through the ground 22. In addition, if the damping device 100 is provided in the pile 12, the damping can also be performed on the pile 12.

  As another example of the first embodiment of the variable stiffness spring of the present invention, a configuration as shown in FIGS. 6A, 6B, and 6C may be used. The variable stiffness spring 150 shown in FIG. 6A is configured by stacking a plurality of mounting units 152. The mounting unit 152 includes an upper mounting member 154 and a lower mounting member 156 that are respectively mounted on both ends of the coil spring 50, and a position outside the outer peripheral surface of the coil spring 50 and between the upper mounting member 154 and the lower mounting member 156. The housing case 158 that accommodates the MR fluid 56 and the convex portion 160 that is provided in the upper mounting member 154 and is immersed in the MR fluid 56 are configured.

  Here, when the coil spring 50 is energized from a control device (not shown) and the magnetic field M is generated, the granular magnetic body G forms a cluster by the action of the magnetic field M, and the MR fluid 56 becomes solid, and the coil spring 50 Displacement is prevented. Thereby, the rigidity of the variable rigidity spring 150 can be changed.

  On the other hand, as shown in FIG. 6B, the energizing unit 162 including the power source may be connected only to the coil spring 50 to change the rigidity of only one coil spring 50, and FIG. As shown in FIG. 4, the coil springs 50 and 62 are connected to energizing units 162 and 164 including a power source, respectively, to change the rigidity of the two coil springs 50 and 62, and the rigidity of the remaining one coil spring 72 is left as it is. May be. When there are three coil springs as in this embodiment, there are seven combinations of coil springs that change the rigidity.

  Next, a variable stiffness spring, a vibration damping device, and a second embodiment of the structure of the present invention will be described with reference to the drawings. Note that the same reference numerals as those in the first embodiment are given to the same elements as those in the first embodiment described above, and the description thereof is omitted.

  As shown in FIG. 7, a variable stiffness spring 170 is attached between the ceiling wall 104 of the central portion 14B (see FIG. 2) of the column 14 and the top plate 116 of the vibration damping device 100 (see FIG. 2). . The variable stiffness spring 170 replaces the variable stiffness spring 40 of the vibration damping device 100 described above. The variable rigid spring 170 is configured by stacking three attachment units 172.

  The attachment unit 172 includes an upper plate member 174 and a lower plate member 176 respectively attached to both ends of the coil spring 50, and a magnetic member made of a magnetic material such as iron attached to the upper end outer peripheral surface of the coil spring 50 along the winding direction. 178 and an electromagnet 180 that is disposed outside the magnetic member 178 so as to face the magnetic member 178 and is energized by the control device 30 via the cable 182 to generate a magnetic field.

  Next, the operation of the second embodiment of the present invention will be described.

  It is assumed that a concert is performed in the hall 24 (see FIG. 1), the first music is finished, the second music is started, and a group of people jumps to the music again to generate a vibration wave. Based on the vibration data transmitted from the vibration sensor 26 (see FIG. 1), the control device 30 changes the amount and direction of energization of the electromagnetic coil 130 (see FIG. 2b) and adjusts the amplitude of the vibration wave. .

  Further, the control device 30 obtains a spring constant K required for the entire variable stiffness spring 170 and selects which of the three attachment units 172 should be changed in rigidity. Here, since the same three attachment units 172 are stacked, if the displacement of the three attachment units 172 is not prevented, 1 / K = 1 / K1 + 1 / K1 + 1 / K1 = 3 / K1 and one attachment When blocking the displacement of the unit 172, 1 / K = 2 / K1, and when blocking the displacement of the two mounting units 172, 1 / K = 1 / K1. Note that three attachment units having different spring constants may be used.

  Subsequently, the electromagnet 180 facing the mounting unit 172 selected by the control device 30 is energized from the control device 30 to generate a magnetic field. The generated magnetic field acts on the magnetic member 178 attached to the coil spring 50 to lock the magnetic member 178 at a position facing the electromagnet 180. As a result, the coil spring 50 is prevented from being displaced in the vertical direction, and the spring constant of the selected mounting unit 172 changes.

  In the vibration damping device 100 in which the spring constant of the selected mounting unit 172 has changed, the vibration frequency of the vibration exciting unit 108 is adjusted, and the vibration propagating to the central portion 14B of the column 14 is damped. As described above, the displacement of the coil spring 50 may be prevented by using the magnetic member 178 and the electromagnet 180 as the displacement prevention means.

  Next, a third embodiment of the variable stiffness spring of the present invention will be described with reference to the drawings. Note that the same reference numerals as those in the first embodiment are given to the same elements as those in the first embodiment described above, and the description thereof is omitted.

  FIGS. 8A and 8B show a state in which the variable stiffness spring 212 is used in a part of a car 200 that is an example of a vehicle. As shown in FIG. 8A, the car 200 has a vehicle body 202 as a main body. An axle 204 is provided on the bottom side of the vehicle body 202, and tires 206 are rotatably attached to both ends of the axle 204. A substantially rectangular parallelepiped pedestal 208 is provided near the end of the axle 204, and a suspension part 210 is attached to the upper surface of the pedestal 208.

  The suspension unit 210 includes a variable stiffness spring 212 as an elastic element having appropriate rigidity with respect to the vertical movement of the tire 206, and a shock absorber 214 as an appropriate vibration damping element. Note that the upper ends of the variable stiffness spring 212 and the shock absorber 214 are respectively attached to the vehicle body 202 by bolts or the like (not shown).

  As shown in FIG. 8B, the variable stiffness spring 212 is composed of three mounting units 213 and a selective energization unit 230 that are stacked. The attachment unit 213 includes an upper plate member 218 and a lower plate member 220 attached to both ends of the coil spring 216, a storage case 222 that is provided between the upper plate member 218 and the lower plate member 220, and stores the MR fluid 56, and an upper plate member. And a convex portion 224 that protrudes from the lower surface of 218 and is immersed in the MR fluid 56.

  At the connection portion of each mounting unit 213, the upper plate member 218 and the lower plate member 220 are fixed by fastening means such as bolts and nuts (not shown). On the other hand, the upper end of the coil spring 216 is connected to one end of the cable 226A, and the lower end of the coil spring 216 is connected to one end of the cable 226B. The other ends of the cables 226A and 226B are connected to the selective energization unit 230.

  The selection energization unit 230 selects the spring constant K of the variable stiffness spring 212 based on the vibration frequency measured by a vibration sensor (not shown) attached to the vehicle body 202 (see FIG. 8A). Yes. The selective energizing unit 230 energizes at least one coil spring 216 among the three attachment units 213 based on the spring constant K of the selected variable stiffness spring 212.

  When at least one of the three coil springs 216 is energized by the selective energization unit 230, the spring constant K of the variable stiffness spring 212 changes. As a result, the stiffness of the variable stiffness spring 212 changes, and the frequency of the vibration generated in the vehicle body 202 (see FIG. 8A) changes.

  Next, the operation of the third embodiment of the present invention will be described.

  As shown in FIG. 8A and FIG. 8B, when the vehicle 200 travels on a general road with relatively many irregularities, for example, the vibration frequency is measured by a vibration sensor (not shown) attached to the vehicle body 202. The Here, the electrification unit 230 selects the spring constant K of the variable stiffness spring 212 so that the vibration is canceled based on the frequency of the vibration, and the three attachment units 213 so that the selected spring constant K is obtained. Among these, at least one coil spring 216 is energized.

  In the energized coil spring 216, a magnetic field corresponding to the energization amount from the selective energization unit 230 and the number of turns of the coil spring 216 is generated. In the MR fluid 56 in the housing case 222, the magnetic field acts, whereby the granular magnetic body forms a cluster and becomes solid. Thereby, the displacement of the convex portion 224 of the upper plate 218 is prevented, and the displacement of the coil spring 216 is prevented.

  By preventing the displacement of the coil spring 216, the spring constant K of the variable stiffness spring 212 changes and the stiffness changes, so that the suspension unit 210 has an appropriate stiffness. In the suspension unit 210, moderate vibration damping is performed by the shock absorber 214. As described above, since the suspension unit 210 has appropriate rigidity and appropriate vibration attenuation is performed in the suspension unit 210, moderate vibration suppression is performed with respect to vibration caused by the vertical movement of the tire 206, and the interior of the vehicle 200 is reduced. It is possible to give a comfortable ride to the crew. In addition, the steering stability of the car 200 is increased by appropriate rigidity and vibration damping.

  In addition, this invention is not limited to said embodiment. The vibration sensor 26 may be provided anywhere as long as it is at the pillar 14. The vibration damping device 100 may be provided on the upper portion or the upper end portion of the pile 12 according to the structure of the building 10. The vibration unit 108 may be provided in one of the storage units 107A and 107B. The vibration adjustment unit 110 may be configured by the variable stiffness spring 40 at all three locations.

The magnetic field generating means is not limited to the one that directly energizes the coil spring, but a coil member that can be conducted separately from the coil spring may be arranged to energize the MR fluid 56 to act on the magnetic field. When the magnetic field generating means does not directly energize the spring member, the spring member is not limited to the coil spring but may be a leaf spring or the like.
Further, the magnetic field may be applied to the MR fluid 56 by arranging magnets close to or spaced apart from each other.

  The number of the spring 112 and the variable stiffness spring 40 arranged in parallel may be either a single number or a plurality. The number of coil springs and mounting units to be stacked is not limited to three, and may be two or more, and may be one when the spring 112 is used.

1 is an overall view of a building provided with a vibration damping device according to a first embodiment of the present invention. (A) It is a perspective view of the damping device concerning a 1st embodiment of the present invention. (B) It is sectional drawing of the damping device which concerns on 1st Embodiment of this invention. (A) It is sectional drawing of the variable rigidity spring which concerns on 1st Embodiment of this invention. (B) It is explanatory drawing which shows the generation | occurrence | production state of the magnetic field in the attachment unit which concerns on 1st Embodiment of this invention. (A)-(c) It is the schematic diagram and sectional drawing which show the locked state of a spring member when it supplies with electricity to each attachment unit which concerns on 1st Embodiment of this invention. It is the schematic diagram which showed the damping state by the damping device which concerns on 1st Embodiment of this invention using the vibration wave. It is sectional drawing which shows the other Example of the variable rigidity spring which concerns on 1st Embodiment of this invention. It is a schematic diagram of the variable rigidity spring which concerns on 2nd Embodiment of this invention. (A) It is a partial view of the vehicle provided with the variable rigidity spring which concerns on 3rd Embodiment of this invention. (B) It is sectional drawing of the variable rigidity spring which concerns on 3rd Embodiment of this invention.

Explanation of symbols

10 Building (structure)
12 Pile
14 pillars
26 Vibration sensor (measuring means)
30 Control device (control means)
40 Variable stiffness spring (variable stiffness spring)
42 Mounting unit (Mounting unit, displacement prevention means)
44 Mounting unit (Mounting unit, displacement prevention means)
46 Mounting unit (Mounting unit, displacement prevention means)
48 selective energization unit (magnetic field selection generation means, displacement prevention means)
50 Coil spring (spring member, magnetic field generating means)
52 Upper mounting member (Mounting member, displacement prevention means)
54 Lower mounting member (Mounting member, displacement prevention means)
56 MR fluid (MR fluid)
58 Storage case (storage part, displacement prevention means)
60 Convex (convex, displacement prevention means)
62 Coil spring (spring member, magnetic field generating means)
64 Upper mounting member (Mounting member, displacement prevention means)
66 Lower mounting member (Mounting member, displacement prevention means)
68 Storage case (storage part, displacement prevention means)
70 Convex (convex, displacement prevention means)
72 Coil spring (spring member, magnetic field generating means)
74 Upper mounting member (Mounting member, displacement prevention means)
76 Lower mounting member (Mounting member, displacement prevention means)
78 Storage case (storage part, displacement prevention means)
80 Convex (convex, displacement prevention means)
100 Damping device (damping device)
108 Excitation unit (vibration control means, excitation unit)
110 Vibration adjustment unit (vibration control means)
150 Variable stiffness spring (variable stiffness spring)
158 Storage case (storage part, displacement prevention means)
160 Convex (convex, displacement prevention means)
170 Variable stiffness spring (variable stiffness spring)
174 Upper plate (mounting member, displacement prevention means)
176 Lower plate (mounting member, displacement prevention means)
178 Magnetic member (displacement prevention means)
180 Electromagnet (Displacement prevention means)
212 Variable stiffness spring (variable stiffness spring)
213 Mounting unit (Mounting unit, displacement prevention means)
216 Coil spring (spring member, magnetic field generating means)
218 Upper plate (mounting member, displacement prevention means)
220 Lower plate (mounting member, displacement prevention means)
222 Storage case (storage part, displacement prevention means)
224 Convex part (convex part, displacement prevention means)
230 Selection energization unit (magnetic field selection generation means, displacement prevention means)
M magnetic field

Claims (7)

A plurality of spring members arranged in series;
A displacement preventing means provided on at least one of the plurality of spring members, and preventing displacement of the spring members;
A variable rigidity spring characterized by comprising: The displacement prevention means comprises:
An attachment member attached to each end of the spring member; an accommodation portion provided between the pair of attachment members for containing MR fluid; and a protrusion provided on the one attachment member and immersed in the MR fluid. A mounting unit comprising:
Magnetic field generating means for generating a magnetic field and applying the magnetic field to the MR fluid;
The variable stiffness spring according to claim 1, comprising: The magnetic field generating means is a coil spring as the spring member,
The variable stiffness spring according to claim 2, wherein the magnetic field is generated by energizing the coil spring. A plurality of the mounting units stacked;
Magnetic field selection generating means for selectively energizing the coil spring to generate a magnetic field;
The variable stiffness spring according to claim 3, wherein   The variable stiffness spring according to any one of claims 1 to 4, wherein the spring constants of the plurality of spring members are different from each other. Measuring means for measuring the vibration frequency and amplitude of the structure generated in the vertical direction and provided in the structure, and a vertical damping force provided in the column or pile of the structure and canceling the vibration of the structure In the vibration damping device, comprising:
The vibration damping means is
An excitation unit capable of vibrating in the vertical direction;
The variable stiffness spring according to any one of claims 1 to 5, wherein the variable stiffness spring is provided between the excitation unit and the pillar or the pile.
The vibration control device characterized in that the control means vibrates the excitation unit based on the amplitude and changes the stiffness of the variable stiffness spring based on the frequency.   A structure in which the vibration damping device according to claim 6 is provided on a pillar or a pile.