Pendulum device, vibration control device and designing method of vibration control device

Abstract

To provide a pendulum device capable of adjusting amplitude dependence of a restoring force by gravity of a pendulum to desirable characteristics.SOLUTION: A pendulum device 1 includes a pendulum member 2 which is hung down by a shaft 32 provided on a pendulum supporting member 3 and performs pendulum motion within a vertical surface with a shaft 32 as a fulcrum and a pair of fixed magnetic members 4a, 4b which are arranged so as to interpose the pendulum member 2 within a vertical surface on which the pendulum member 2 performs pendulum motion. Therein, the pendulum member 2 has a pair of pendulum side magnetic members 22a, 22b which face each of the pair of fixed magnetic members 4a, 4b, and magnetic polarity of the side which faces each of the fixed magnetic members 4a, 4b and the pendulum side magnetic members 22a, 22b is respectively the same, and the fixed magnetic members 4a, 4b give repulsion forces to the pendulum magnetic members 22a, 22b.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pendulum device, a vibration damping device, and a method for designing a vibration damping device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, vibration damping devices that reduce the shaking of structures caused by wind or earthquakes have been known, such as those that use a pendulum to damp vibration (see, for example, Patent Document 1). In such a vibration control device using a pendulum, for example, a method is known in which a vibration control effect is obtained by using a pendulum in which the natural frequency of the object to be controlled and the natural frequency of the pendulum are 1:1. Also, in a vibration control device using a pendulum, a method has been proposed in which a pendulum-type dynamic vibration absorber system using autoparametric excitation is constructed, and a pendulum in which the natural frequency of the object to be controlled and the natural frequency of the pendulum are 1:1 / 2 is used to obtain a vibration control effect (for example, see Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-125976 [Non-patent literature]

[0004] [Non-Patent Document 1] “Response of a Dynamic Vibration Absorber System Using Parametric Excitation of a Pendulum”, Transactions of the Japan Society of Mechanical Engineers (Series C), Vol. 67, No. 661 (2001-9), Paper No. 00-1494, pp. 15-21 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when a pendulum is allowed to oscillate freely, in areas where the swing angle of the pendulum is large and the amplitude is large, the restoring force due to gravity acting on the pendulum is not proportional to the swing angle of the pendulum, but becomes nonlinear, and the pendulum's natural frequency changes. Therefore, in vibration control devices that use pendulums, in areas where the amplitude of the pendulum is large and the restoring force is nonlinear, the ratio of the natural frequency of the object to be controlled cannot be maintained at the required value (1:1 or 1:1 / 2, etc.), reducing the vibration control effect, or the pendulum moves chaotically. For this reason, pendulums are used only in a small amplitude range where the nonlinear effect can be ignored, and vibration control effects are obtained within this amplitude range.

[0006] In a pendulum-type dynamic vibration absorber system that uses autoparametric excitation, the natural frequency of the pendulum is set to half the natural frequency of the object to be damped, the mass of the pendulum weight is reduced, and the amplitude of the pendulum is increased accordingly, thereby obtaining the required restoring force. However, in areas where the amplitude of the pendulum is large, the restoring force due to gravity acting on the pendulum is not proportional to the angle of the pendulum, and the natural frequency changes according to the magnitude of the pendulum's amplitude. If the natural frequency changes, the condition of 1 / 2 mentioned above will not be met, and sufficient vibration control effect cannot be obtained, resulting in a problem of reduced vibration control performance of the vibration control device.

[0007] Therefore, the present invention has been made with attention to the above-mentioned conventional unsolved problems, and has an object to provide a pendulum device that makes it possible to adjust the amplitude dependency of the restoring force due to gravity of the pendulum to desired characteristics, as well as a vibration control device that uses this pendulum device and a method of designing a vibration control device. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a pendulum device comprising: a pendulum member that performs pendulum motion around a fulcrum and is at least partially constituted by a first magnetic member; and a fixed member that applies a magnetic repulsive or attractive force to the pendulum member and is at least partially constituted by a second magnetic member.

[0009] According to another aspect of the present invention, there is provided a vibration control device that controls vibration of an object to be vibration-controlled by using a pendulum device that performs pendulum motion, the pendulum device using the pendulum device of the above aspect as the pendulum device.

[0010] Furthermore, according to another aspect of the present invention, there is provided a method for designing a vibration control device that uses a pendulum member that performs pendulum motion to control the vibration of an object to be controlled, the method comprising: arranging a first magnetic member on at least a part of the pendulum member; arranging a second magnetic member in a position that applies a magnetic repulsive or attractive force to the first magnetic member; and adjusting at least one of the magnetic flux densities of the first magnetic member and the second magnetic member, the relative position between the first magnetic member and the second magnetic member, and the mass of the pendulum member so that the sum of the restoring force due to gravity of the pendulum member and the restoring force due to magnetic force between the first magnetic member and the second magnetic member has desired restoring force characteristics.

[0011] Furthermore, according to another aspect of the present invention, there is provided a pendulum device which comprises: a first magnetic member disposed on at least a part of a pendulum member which performs pendulum motion around a fulcrum and at least a part of which is constituted by a first magnetic member; and a second magnetic member disposed in a position which exerts a magnetic repulsive or attractive force on the first magnetic member; and which adjusts at least one of the magnetic flux densities of the first magnetic member and the second magnetic member, the relative position of the first magnetic member and the second magnetic member, and the mass of the pendulum member so that the sum of the restoring force due to gravity of the pendulum member and the restoring force due to the magnetic force between the first magnetic member and the second magnetic member has desired restoring force characteristics.

[0012] According to another aspect of the present invention, there is provided a pendulum device comprising: a first pendulum member which performs pendulum motion about a fulcrum and at least a portion of which is constituted by a first magnetic member; a first fixed member which applies a magnetic repulsive force to the first pendulum member and at least a portion of which is constituted by a second magnetic member; a second pendulum member which performs pendulum motion about the fulcrum and at least a portion of which is constituted by a third magnetic member; and a second fixed member which applies a magnetic attractive force to the second pendulum member and at least a portion of which is constituted by a fourth magnetic member. Effect of the Invention

[0013] According to one aspect of the present invention, in a pendulum device, the amplitude dependency of the restoring force can be adjusted to desired characteristics, and by using this pendulum device, it is possible to suppress the deterioration of the vibration damping performance of the vibration damping device that is associated with the amplitude dependency of the restoring force. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram showing an example of a vibration damping device according to the present invention. [Diagram 2] FIG. 1 is a configuration diagram showing an example of a pendulum device according to the present invention. [Diagram 3] 11 is a graph showing a displacement state when a pendulum body is allowed to freely vibrate without the action of a restoring force from a magnetic member. [Figure 4] 4 is a graph showing the spinal curve of FIG. 3. [Diagram 5] 1 is a graph showing a time history waveform obtained in an experiment when the pendulum member according to the present invention is allowed to freely vibrate. [Figure 6] 6 is a graph showing the spinal curve of FIG. 5. [Figure 7] 1 is a graph showing a time history waveform obtained in an experiment when the pendulum member according to the present invention is allowed to freely vibrate. [Figure 8] 8 is a graph showing the spinal curve of FIG. 7. [Figure 9] FIG. 13 is an explanatory diagram showing a schematic diagram of a horizontally moving magnet for explaining a magnetic force acting on a pendulum-side magnetic member. [Figure 10] 1 is a graph showing the relationship between the amount of movement of a magnet and the ratio of the coefficient of the first-order term to the coefficient of the third-order term in a mathematical formula that represents the total magnetic force acting on a horizontally moving magnet. [Figure 11] FIG. 3 is a schematic diagram of the pendulum device shown in FIG. 2. [Figure 12] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining a fourth modified example. [Figure 13] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining a fourth modified example. [Figure 14] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining a fourth modified example. [Figure 15] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 5. [Figure 16] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 7. [Figure 17] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 7. [Figure 18] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 7. [Figure 19] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 7. [Figure 20] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 7. [Figure 21] FIG. 13 is an explanatory diagram illustrating a pendulum device for explaining Modification 7. [Figure 22] FIG. 23 is an explanatory diagram illustrating a pendulum device for explaining Modification 8. [Diagram 23] FIG. 13 is an explanatory diagram of the mounting position of a pendulum device, provided for explaining Modification 9. [Figure 24] FIG. 13 is an explanatory diagram of the mounting position of a pendulum device, provided for explaining Modification 9. [Diagram 25] FIG. 13 is an explanatory diagram of the mounting position of a pendulum device, provided for explaining Modification 9. [Figure 26]23 is a graph illustrating the relationship between a nonlinear component and a vibration frequency, which is used to explain Modification Example 10. [Figure 27] 23 is a graph illustrating the relationship between a nonlinear component and a vibration frequency, which is used to explain Modification Example 10. [Figure 28] FIG. 1 is an explanatory diagram showing a schematic diagram of a pendulum device for explaining a method for adjusting the motion characteristics of a pendulum member. [Figure 29] FIG. 1 is an explanatory diagram showing a schematic diagram of a pendulum device for explaining a method for adjusting the motion characteristics of a pendulum member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] In the following detailed description, many specific configurations are described to provide a complete understanding of the embodiments of the present invention. However, it is clear that other embodiments can be implemented without being limited to such specific configurations. In addition, the following embodiments do not limit the invention according to the claims. In addition, all combinations of features described in the embodiments are not necessarily essential to the solution of the invention.

[0017] <Embodiment> Here, a case will be described in which the pendulum device 1 according to one embodiment of the present invention is applied to a vibration damping device 10 for a building 20, but the application is not limited to the vibration damping device 10 for the building 20.

[0018] FIG. 1( a ) is a vibration model showing an example of a vibration damping device 10 . In Fig. 1(a), M, k, and c are the mass, spring constant, and viscous damping coefficient of the main system, respectively. Also, m, θ, and L are the mass of the pendulum member, the angle of the pendulum member from the perpendicular line, and the distance from the fulcrum to the other end of the pendulum member, respectively. 1(b) is a conceptual diagram of a structure in which the vibration control device 10 is provided on a building 20. The vibration control device 10 is provided on the roof of the building 20 to suppress lateral shaking of the building 20.

[0019] FIG. 2 is a front view showing an example of the pendulum device 1. As shown in FIG. The pendulum device 1 includes a pendulum member that performs pendulum motion around a fulcrum and at least a part of which is constituted by a first magnetic member, and a fixed member that applies a repulsive or attractive force due to a magnetic force to the pendulum member and at least a part of which is constituted by a second magnetic member.

[0020] Specifically, the pendulum device 1 comprises a pendulum member 2, a pendulum support member 3 that supports the pendulum member 2, a pair of fixed magnetic members (second magnetic members) 4a, 4b provided on either side of the pendulum member 2, magnetic member support parts 5a, 5b that support the fixed magnetic members 4a, 4b, and a support main body 6 that supports the pendulum support member 3 and the magnetic member support parts 5a, 5b. The pendulum member 2 is suspended from a pendulum support member 3 and performs pendulum motion within a vertical plane with an axis 32 of the pendulum support member 3 as a fulcrum.

[0021] The pendulum member 2 comprises a pendulum body 21 and a pair of pendulum-side magnetic members 22a, 22b. The pendulum body 21 is formed from a thin, elongated rectangular plate, and the pendulum-side magnetic members 22a, 22b are provided on the front and back surfaces of the pendulum body 21. As described below, a repulsive force acts on the pendulum body 21, which is generated between the fixed magnetic members 4a, 4b and the pendulum-side magnetic members 22a, 22b, so it is preferable that the pendulum body 21 has a rigidity that does not deform even when the repulsive force acts on it.

[0022] The pendulum side magnetic members (first magnetic members) 22a, 22b are formed of plate-shaped magnets made of thin, elongated rectangular permanent magnets, with one of the front and back surfaces magnetized to the N pole and the other magnetized to the S pole. The pendulum side magnetic members 22a, 22b are fixed to the front and back surfaces of the pendulum main body 21 so that one surface of the pendulum main body 21 is the N pole and the other surface is the S pole. Here, the pendulum side magnetic members 22a and 22b are provided on the front and back surfaces of the pendulum main body 21, respectively, but it is also possible to use a single pendulum side magnetic member itself, with one front and back surface magnetized to the N pole and the other to the S pole, for example, as the pendulum main body 21.

[0023] The pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b do not have to be permanent magnets as long as they can generate a repulsive force between the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b, etc., but from the standpoint of ease of use, it is preferable that they be permanent magnets.

[0024] Furthermore, from the viewpoint of adjusting the restoring force, it is preferable that the pendulum side magnetic member 22a and the pendulum side magnetic member 22b have the same magnetic flux density and size, and similarly, it is preferable that the fixed magnetic member 4a and the fixed magnetic member 4b have the same magnetic flux density and size. One end of the pendulum body 21 is attached to the axis 32 of the pendulum support member 3. At this time, the pendulum body 21 performs pendulum motion in the vertical plane with the axis 32 as the fulcrum, and the pendulum side magnetic members 22a and 22b are attached so as to face the direction in which the amplitude of the pendulum body 21 increases.

[0025] In the pendulum member 2, the entire pendulum body 21 to which the pendulum side magnetic members 22a and 22b are fixed plays the role of the pendulum weight. Here, the pendulum body 21 itself is used as the weight, but this is not limited thereto, and the pendulum body 21 may be provided with a separate weight. The pendulum support member 3 comprises a support mechanism 31 and an axis 32 extending in a direction perpendicular to the plane of the paper in Figure 2. The support mechanism 31 connects the axis 32 to the pendulum member 2 via a bearing, etc., so that the pendulum member 2 is supported so as to be freely movable around the axis 32 as a fulcrum, allowing it to perform pendulum motion.

[0026] The fixed magnetic members 4a and 4b are formed of, for example, cylindrical ferrite magnets, with one surface in the thickness direction magnetized to the N pole and the other surface magnetized to the S pole. The magnetic member support part 5a is formed by connecting a first member 51a and a second member 52a in a shape that is approximately the shape of a letter "L" in the hiragana character. The inner angle formed by the first member 51a and the second member 52a is on the pendulum member 2 side, and the end part of the first member 51a side is fixed to the support part main body 6 so that the second member 52a extends in the vertical direction. The fixed magnetic member 4a is fixed to the end part of the magnetic member support part 5a on the second member 52a side, and the fixed magnetic member 4a is arranged so that its magnetized surface faces the magnetized surface of the pendulum side magnetic member 22a fixed to the pendulum main body 21 in a stationary state (equilibrium state). The fixed magnetic member 4a has a magnetic polarity such that the magnetic polarities of the mutually facing magnetized surfaces of the fixed magnetic member 4a and the pendulum side magnetic member 22a are the same polarity.

[0027] The magnetic member support part 5b is formed by connecting a first member 51b and a second member 52a in a shape that is approximately an inverted "L" character of the Japanese hiragana, and the inner angle formed by the first member 51b and the second member 52b is on the pendulum member 2 side, and the end part on the first member 51b side is fixed to the support part main body 6 so that the second member 52b extends in the vertical direction. The fixed magnetic member 4b is fixed to the end part on the second member 52b side of the magnetic member support part 5b, and the fixed magnetic member 4b is arranged so that its magnetized surface faces the magnetized surface of the pendulum side magnetic member 22b fixed to the pendulum main body 21 in a stationary state. In addition, the fixed magnetic member 4b has a magnetic polarity such that the magnetic polarities of the mutually facing magnetized surfaces of the fixed magnetic member 4b and the pendulum side magnetic member 22b are the same polarity.

[0028] The magnetic member support parts 5a and 5b are configured to be symmetrical about the pendulum member 2 in a stationary state. The magnetic member support parts 5a and 5b are arranged so as not to impede the movement of the pendulum member 2 when it performs a pendulum motion. Furthermore, the magnetic member support parts 5a and 5b are attached to the support part main body 6 so that their vertical positions can be changed. The pendulum support member 3 is attached to the support part main body 6 so that its vertical position can be changed. This allows the vertical relative positions of the fixed magnetic members 4a and 4b and the pendulum side magnetic members 22a and 22b to be adjusted by adjusting the vertical positions of the magnetic member support parts 5a and 5b and the vertical position of the shaft 32. In other words, the repulsive force between the fixed magnetic members 4a and 4b and the pendulum side magnetic members 22a and 22b can be adjusted. It should be noted that not only the vertical positions but also the horizontal positions of the magnetic member support parts 5a and 5b may be configured to be adjustable.

[0029] The support body 6 to which the magnetic member support parts 5a, 5b and the pendulum support member 3 are attached is fixed to a building 20, which is the object to be vibration-controlled, so that the pendulum member 2 is suspended in the vertical direction.

[0030] In the pendulum device 1 having such a configuration, the pendulum member 2 performs pendulum motion with the axis 32 as the fulcrum, and as the pendulum side magnetic members 22a, 22b fixed to the pendulum main body 21 approach the opposing fixed magnetic members 4a, 4b, respectively, a repulsive force is generated between the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b, and the repulsive force acts on the pendulum member 2. Therefore, the restoring force is larger than when the fixed magnetic members 4a, 4b and the pendulum side magnetic members 22a, 22b are not present.

[0031] <Restoring force characteristics> Here, the restoring force characteristics of the pendulum member 2 will be described. When the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b are not provided, the restoring force of the pendulum body 21 due to gravity can be expanded in a power series by Taylor expansion of sin θ as shown in the following equation (1). In equation (1), m is the mass of the pendulum member 2, g is the gravitational acceleration, and θ is the displacement angle from the stationary state.

[0032]

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[0033] As shown in equation (1), the coefficient of the term proportional to the cube is negative, so the restoring force due to gravity has the nonlinear characteristics of a soft spring. Figure 3 shows the displacement state taking into account the direction of movement of pendulum body 21 when it is allowed to freely vibrate, and Figure 4 shows the spine curve that shows the relationship between the amplitude and natural frequency of pendulum body 21 based on the stationary state. It can be seen from Figure 4 that the natural frequency changes depending on the amplitude, resulting in soft spring characteristics.

[0034] On the other hand, as shown in FIG. 2, when the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b are provided, the restoring force F of the pendulum due to the magnetic force is m can be expressed by Taylor expansion as shown in the following equation (2).

[0035]

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[0036] Therefore, as shown in FIG. 2, when the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b are provided, the restoring force characteristics of the pendulum can be approximated by the following formula (3) from formulas (1) and (2).

[0037]

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[0038] Equation (3) can be summarized into a linear component and a nonlinear component as shown in the following equation (4).

[0039]

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[0040] Here, when the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b are opposed to each other and the magnetic poles of the opposing surfaces are made the same, that is, when a repulsive force is generated, F in formula (4) is 1 is positive (linear restoring force characteristic) 、 F 3 is positive (hard spring characteristic). When the magnetic poles of the opposing surfaces of the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b are opposite to each other, that is, when an attractive force is generated, F 1 is negative (does not have linear restoring force characteristics) 、 F 3 is negative (soft spring characteristic).

[0041] From equation (4), F 3 It can be seen that if F is adjusted to satisfy the following formula (5), the nonlinearity of the restoring force acting on the pendulum member 2 due to gravity and magnetic force can be suppressed. 3 The magnetic flux density, magnet shape and arrangement of the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b, as well as the mass of the pendulum member 2, specifically the mass of the pendulum main body 21 and the pendulum side magnetic members 22a, 22b, etc., can be selected so as to satisfy equation (5), and the magnetic force acting on the pendulum member 2 can be adjusted.

[0042]

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[0043] As shown in Fig. 2, in the pendulum device 1 equipped with the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b and adjusted to satisfy formula (5), the time history waveform obtained in an experiment when the pendulum member 2 was allowed to freely vibrate is shown in Fig. 5, and the spine curve obtained in the experiment, which shows the relationship between the amplitude and natural frequency of the pendulum member 2, is shown in Fig. 6. It can be seen from Fig. 6 that there is almost no change in the natural frequency depending on the magnitude of the amplitude of the pendulum member 2.

[0044] Figures 7 and 8 show the time history waveform (Figure 7) and the spine curve (Figure 8) obtained in an experiment showing the relationship between the amplitude and natural frequency of the pendulum member 2 when the pendulum device 1 shown in Figure 2, which has been adjusted to satisfy formula (5), is made to use two ferrite magnets each as the fixed magnetic members 4a and 4b, the magnetic force acting on the pendulum member 2 is increased, and the pendulum member 2 is allowed to freely vibrate. Figure 8 shows that by forming the fixed magnetic members 4a and 4b by stacking two ferrite magnets each, the restoring force of the hard spring characteristics due to the magnetic force greatly exceeds the restoring force of the soft spring characteristics due to gravity, and as a whole, a hard spring characteristic is shown in which the natural frequency increases as the amplitude increases.

[0045] In other words, by changing the number of magnets used as the magnetic members, the magnetic flux density of the magnetic members, and the arrangement position of the magnetic members to adjust the restoring force due to magnetic force, it is possible to adjust the restoring force characteristics of the pendulum member, which is the sum of the restoring force due to gravity and the restoring force due to magnetic force. In the above formula (5), "(mg / 6) = F 3 By adjusting the restoring force by the magnetic force so as to satisfy "(mg / 6)", it is possible to generate a linear restoring force as shown in Figs. 5 and 6, and the natural frequency can be maintained approximately constant regardless of the amplitude. <F 3 By adjusting the restoring force by the magnetic force so as to satisfy "(mg / 6)>F", it is possible to generate a restoring force having hard spring characteristics, as shown in Figs. 7 and 8. On the other hand, if "(mg / 6)>F 3By adjusting the restoring force due to magnetic force so as to satisfy the condition "1.0," it is possible to generate a restoring force with stronger soft spring characteristics compared to when there is no magnet, as shown in Figures 3 and 4.

[0046] The displacement state of the pendulum main body 21 and the pendulum member 2 was measured under the following conditions. (a) When the pendulum member 2 shown in FIG. 2 was used (corresponding to FIGS. 5 and 6), the conditions for measuring the displacement state were as follows: The fixed magnetic members 4a and 4b were cylindrical ferrite magnets with a diameter d of 18 mm and a thickness t of 5 mm. The horizontal distance between the pendulum side magnetic members 22a and 22b and the fixed magnetic members 4a and 4b was 63 mm, and the vertical distance between the vertical center of the fixed magnetic members 4a and 4b and the center of the shaft 32 was 50 mm.

[0047] The measurement was performed using a laser displacement meter (LK-G35A, manufactured by Keyence Corporation) by fixing the laser displacement meter to the magnetic member support portion 5b and measuring the distance from the pendulum-side magnetic member 22b. At this time, the horizontal distance to the pendulum-side magnetic member 22b was measured using a point 16 mm away in the vertical direction from the center of the axis 32 of the stationary pendulum member 2. When the swing width of the pendulum member 2 (the change width of the measurement value by the laser displacement meter) was 5 mm, the rotation angle of the pendulum member 2 was approximately 17 degrees.

[0048] (b) In the case where the fixed magnetic members 4a, 4b and the pendulum side magnetic members 22a, 22b are not present (corresponding to Figs. 3 and 4), that is, the conditions for measuring the displacement state of the pendulum main body 21 are as follows. That is, the measurement was performed under the same conditions as those for the above-mentioned (a) when the pendulum member 2 in Fig. 2 was used, except that the fixed magnetic members 4a, 4b and the pendulum side magnetic members 22a, 22b were not provided. In other words, the measurement point was set to a point 16 mm away in the vertical direction from the center of the axis 32 of the pendulum main body 21 in a stationary state, and the horizontal distance to the pendulum main body 21 was measured.

[0049] (c) In the case where a pendulum member 2 having two ferrite magnets as fixed magnetic members 4a and 4b is used (corresponding to Figs. 7 and 8), the conditions for measuring the displacement state are as follows: That is, the measurement was performed under the same conditions as those for the case where the pendulum member 2 in Fig. 2 (a) was used above, except that two ferrite magnets were used as the fixed magnetic members 4a and 4b. That is, two cylindrical ferrite magnets with a diameter d of 18 mm and a thickness t of 5 mm were stacked as the fixed magnetic members 4a and 4b, and the fixed magnetic members 4a and 4b were essentially ferrite magnets with a thickness of 10 mm. The horizontal distance to the pendulum-side magnetic member 22b was measured from a point 16 mm away from the center of the axis 32 of the pendulum member 2 in a stationary state as the measurement point.

[0050] In addition, in Figs. 3, 5, and 7, the horizontal axis indicates elapsed time, and the vertical axis indicates displacement taking into account the moving direction of the pendulum member 2 or the pendulum body 21. In Figs. 4, 6, and 8, the horizontal axis indicates frequency, and the vertical axis indicates amplitude. The frequency was calculated from the time interval between peaks in Figs. 3, 5, and 7. In Fig. 3, the natural frequency changes from 1.398 Hz to 1.391 Hz due to the amplitude, which is a change of about 0.5%. In Fig. 5, the natural frequency changes from 1.446 Hz to 1.448 Hz due to the amplitude, which is a change of about 0.1%, and in Fig. 7, the natural frequency changes from 1.511 Hz to 1.518 Hz due to the amplitude, which is a change of about 0.5%.

[0051] <Adjustment of restoring force characteristics> To give the pendulum device 1 a linear restoring force, first, the number of magnets constituting each magnetic member, the magnetic force of the magnets, the installation positions of the magnets, etc. are determined so as to satisfy formula (5) in the pendulum device 1 shown in Fig. 2. Specifically, the restoring force due to magnetic force is adjusted by adjusting the vertical positions of the magnetic member support parts 5a, 5b and the vertical position of the shaft 32, adjusting the number of fixed magnetic members 4a, 4b and the magnetic force of the magnets, the number of pendulum side magnetic members 22a, 22b and the magnetic force of the magnets, adjusting the mass of the pendulum member 2, etc. If the natural frequency of the building 20 as the object to be damped is Ω, the pendulum device 1 is constructed so that the natural frequency ω of the pendulum member 2 satisfies ω=Ω.

[0052] (Characteristics of magnetic force) Here, the characteristics of the magnetic forces acting on the pendulum side magnetic members 22a and 22b will be described. (Magnetic force characteristics during horizontal movement) First, as shown in FIG. 9, magnets A to C are arranged in this order on a plane in a straight line, and the magnetic force characteristics when magnet B moves horizontally between magnets A and C will be described.

[0053] Magnets A to C have the same shape, are formed into thin plates, and one of the front and back sides is magnetized as a north pole and the other as a south pole. Magnets A and B are arranged so that their south poles face each other, and magnets B and C are arranged so that their north poles face each other. The thickness of magnets A to C is d.

[0054] In Figure 9, the initial state is when magnet B is in the middle between magnet A and magnet C, and the gap between magnet A and magnet B in the initial state and the gap between magnet B and magnet C in the initial state are denoted as r. The gap r between magnet A and magnet B represents the horizontal distance from the center of magnet A's thickness to the center of magnet B's thickness. Similarly, the gap r between magnet B and magnet C represents the horizontal distance from the center of magnet B's thickness to the center of magnet C's thickness. In addition, the displacement of magnet B from the initial state is denoted as x, and the displacement x represents the horizontal movement distance of the center of magnet B's thickness. In Figure 9, the force F acting on magnet B by magnet A is L is expressed by the following equation (6).

[0055]

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[0056] Also, the force F acting on magnet B due to magnet C R is expressed by the following equation (7).

[0057]

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[0058] In equations (6) and (7), m is the magnetic flux density of magnet B, m' is the magnetic flux density of magnets A and B, and μ is magnetic permeability. When equation (6) is expanded by Taylor series, it is expressed as the following equation (8).

[0059]

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[0060] When equation (7) is expanded by Taylor series, it is expressed as the following equation (9).

[0061]

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[0062] The total magnetic force F acting on magnet B can be approximated from equations (8) and (9) as shown in the following equation (10).

[0063]

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[0064] Here, in equation (10), the coefficient of the first-order term is defined as in the following equation (11).

[0065]

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[0066] In equation (10), the coefficient of the third-order term is defined as in the following equation (12).

[0067]

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[0068] From equations (11) and (12), the ratio of the coefficient of the first-order term to the coefficient of the third-order term in equation (10) is expressed by the following equation (13).

[0069]

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[0070] In Fig. 10, the horizontal axis represents "d / r" in equation (13), and the vertical axis represents "a 3 / a 1 This graph shows these relationships as the ratio of coefficients "a 3 / a 1 The larger "d / r" is, the greater the nonlinear effect of the magnetic force becomes compared to the linear effect. Therefore, from Figure 10, it can be seen that it is easier to obtain the nonlinear effect of the magnetic force by making "d / r" smaller.

[0071] (Magnetic characteristics during pendulum motion) Next, the magnetic force characteristics during pendulum motion in the pendulum device 1 shown in FIG. 2 will be described. FIG. 11 is a schematic diagram of the pendulum device 1 shown in FIG. When the fixed magnetic members 4a and 4b and the pendulum member 2 having the pendulum-side magnetic members 22a and 22b are in the positional relationship shown in FIG. 11, the force F acting on the pendulum member 2 by the fixed magnetic member 4a is l is expressed by the following equation (14).

[0072]

number

[0073] In addition, the force F acting on the pendulum member 2 by the fixed magnetic member 4b is r is expressed by the following equation (15).

[0074]

number

[0075] In the formulas (14) and (15), m1 is the magnetic flux density of the magnets as the pendulum side magnetic members 22a and 22b attached to the pendulum, m2 is the magnetic flux density of the fixed magnetic members 4a and 4b, μ is the magnetic permeability, and r is the gap between the magnetic poles when in a stationary state. In Fig. 11, when the pendulum side magnetic members 22a and 22b are regarded as an integrated magnetic member, the gap r is the horizontal distance from the center of the thickness of the fixed magnetic member 4a to the center of gravity of the pendulum side magnetic member, and is also the horizontal distance from the center of the thickness of the fixed magnetic member 4b to the center of gravity of the pendulum side magnetic member. x is the displacement of the pendulum member 2 from the stationary state, l is the equivalent length of the pendulum, and is the horizontal distance from the fulcrum Q to the center of gravity of the pendulum side magnetic member. When equation (14) is expanded by Taylor series, it is expressed as the following equation (16).

[0076]

number

[0077] When equation (15) is expanded by Taylor series, it is expressed as the following equation (17).

[0078]

number

[0079] Here, in equations (16) and (17), the following equation (18) is defined, where k is a constant.

[0080]

number

[0081] The force F acting on the pendulum member 2 by the fixed magnetic member 4a l and the force F acting on the pendulum member 2 by the fixed magnetic member 4b. r By adding these together, the restoring force F due to the magnetic force can be approximated as shown in the following equation (19).

[0082]

number

[0083] Furthermore, since x=lsinθ, the following equation (20) can be obtained from equation (19): Here, θ is the displacement angle of the pendulum member 2 from its resting state.

[0084]

number

[0085] On the other hand, the restoring force of the pendulum member 2 due to gravity can be approximated as shown in the following equation (21). In equation (21), m is the mass of the pendulum member 2, l is the equivalent length of the pendulum, which is the length from the fulcrum Q to the center of gravity of the pendulum-side magnetic member, θ is the displacement angle of the pendulum member 2 from its stationary state, θ" is the angular acceleration of the displacement angle θ, and k is a value determined from equation (18).

[0086]

number

[0087] Here, the magnetic force acting on the pendulum member 2 shown in FIG. 11 is an equivalent spring force F * can be considered equivalent to

[0088]

number

[0089] In equation (22), a 1 The term containing the linear component of the magnetic force, a 3 The terms including are nonlinear components of the magnetic force. Equivalent spring force F * is a 1 Linear components including a 3 Depending on the sign of the nonlinear component, including a 1 :a 1 >0: Positive stiffness, a 1<0: Negative stiffness a 3 :a 3 >0: hard spring, a 3 <0: Soft spring

[0090] In equation (20), the coefficient of the first-order term is the coefficient a in equation (22), as shown in the following equation (23). 1 It can be regarded as:

[0091]

number

[0092] Similarly, in equation (20), the coefficient of the third-order term is the coefficient a in equation (22), as shown in the following equation (24). 3 It can be regarded as:

[0093]

number

[0094] Therefore, the coefficient a of the third-order term expressed by equation (24) is set to satisfy the following equation (25). 3 By adjusting each component contained in the magnetic material, the restoring force of the magnetic force of the pendulum member 2 can be adjusted to have hard spring characteristics or soft spring characteristics.

[0095]

number

[0096] <Actions and Effects> When vibration is input to the building 20 as the vibration control target with the restoring force due to the magnetic force adjusted in this way, the support body 6 fixed to the building 20 vibrates in accordance with the vibration of the building 20, and the pendulum member 2 starts to swing in a vertical plane with the axis 32 as the fulcrum. In a region where the amplitude of the pendulum member 2 is relatively small, the restoring force due to the magnetic force, i.e., the repulsive force, is relatively small, and the restoring force due to gravity has a linear component, so that the pendulum member 2 as a whole has a linear restoring force. In a region where the amplitude of the pendulum member 2 is relatively large, the restoring force due to gravity has a nonlinear component, but since the restoring force due to the magnetic force, which has a nonlinear component of a magnitude that cancels out the nonlinear component, is added at the same time as this restoring force due to gravity, the nonlinear component is canceled out, and the pendulum member 2 has a linear restoring force. Therefore, the restoring force is linear regardless of the magnitude of the amplitude of the pendulum member 2.

[0097] For this reason, the restoring force of the pendulum member 2 is linear over a wider range of motion, and as a result, regardless of the amplitude of the pendulum member 2, the natural frequency of the pendulum member 2 can be maintained at a level approximately equivalent to the natural frequency of the building 20, thereby suppressing the deterioration of vibration control performance that depends on the amplitude of the pendulum device 1. Furthermore, because the pendulum member 2 maintains a linear restoring force over a wider operating range of the amplitude of the pendulum member 2, the pendulum member 2 can be made to swing with a larger amplitude than in a pendulum device in which the linear restoring force is limited to a small amplitude range, thereby improving vibration control performance.

[0098] If the linear restoring force of the pendulum member 2 is limited to a small amplitude range, it would be necessary to provide, for example, a vibration damping device for small amplitude and a vibration damping device for large amplitude in order to obtain a vibration damping effect over a wider amplitude range. The vibration damping device 10 according to this embodiment can provide a vibration damping effect over a wider amplitude range, from small amplitude to relatively large amplitude, simply by providing the fixed magnetic members 4a, 4b and the pendulum side magnetic members 22a, 22b, thereby reducing costs and preventing the device from becoming larger.

[0099] Furthermore, since a linear restoring force can be obtained in this way over a wider operating range, a dynamic vibration absorber system that utilizes autoparametric excitation can be constructed, and vibration damping effects can be exerted over a wider operating range, even when, for example, the natural frequency of the object to be damped and the natural frequency of the pendulum device 1 are constructed at "1:1 / 2." Furthermore, with this dynamic vibration absorber system, the mass of the pendulum weight can be reduced, that is, the mass of the pendulum member 2 can be reduced, and therefore the pendulum device 1 and further the vibration damping device 10 can be made lighter.

[0100] Furthermore, a method of performing feedback control is generally known theoretically as a method of removing nonlinear components of the restoring force, but in order to perform feedback control, actuators and sensors must be provided, which complicates the structure of the vibration control device and results in increased costs and power consumption. With the pendulum device 1 according to this embodiment, a pendulum device 1 that generates a linear restoring force can be realized simply by providing the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b. Therefore, it can be realized with a simple structure without increasing costs, and in particular without generating power consumption.

[0101] Furthermore, the magnetic member support parts 5a and 5b and the shaft 32 are attached to the support part main body 6 so that their vertical positions can be changed, making it easy to adjust the restoring force of the pendulum member 2 caused by the magnetic force. Furthermore, the pendulum-side magnetic members 22a, 22b are formed so as to be longer in the vertical direction than the fixed magnetic members 4a, 4b, so that when the pendulum member 2 performs pendulum motion, a repulsive force can be generated between them and the fixed magnetic members 4a, 4b over a wider range, making it possible to efficiently adjust the restoring force caused by the magnetic force.

[0102] <Modification> (Variation 1) In the above embodiment, the case where the restoring force characteristic of the pendulum member 2 is linear has been described. <F 3", the restoring force characteristic of the pendulum device 1 can be made to have a hard spring characteristic. Conversely, if "(mg / 6)>F 3 " can be adjusted to satisfy the condition "soft spring characteristic." For example, by using the pendulum device 1 with hard spring characteristic as the vibration damping device 10 and arranging it on a self-excited vibrating pipe or a plant pipe, it can exhibit good vibration damping performance.

[0103] In order to strengthen the soft spring characteristics of the pendulum device 1, it is necessary to make the magnetic poles of the opposing faces of the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b different from each other to generate an attractive force. In this case, F in the above formula (2) 1 is negative and does not generate a restoring force by itself, so the component mg ​​(mg in the first term on the right-hand side of equation (4)) which represents the effect of gravity is always necessary. For example, as in the pendulum device 201 shown typically in FIG. 19, described as a modified example below, when the pendulum member 202 oscillates in a horizontal plane, gravity does not affect the movement of the pendulum member 202. Therefore, in the pendulum device 201 shown in FIG. 19, if the magnetic poles of the opposing surfaces of the pendulum side magnetic member and the fixed magnetic member are changed to opposite poles, the pendulum device cannot have a restoring force and cannot realize a vibration damping device.

[0104] (Variation 2) In the above embodiment, the natural frequency of the pendulum member 2 may be obtained at a predetermined timing, and the relative positions of the pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b may be adjusted so that the natural frequency coincides with the natural frequency of the building 20 as the object to be damped. For example, the natural frequency of the pendulum member 2 is calculated by measuring the distance to the pendulum member 2 using a laser displacement meter and calculating the natural frequency from the measurement results. An adjustment mechanism is provided that can adjust the relative position of the magnetic member supports 5a and 5b that support the fixed magnetic members 4a and 4b and the support body 6, and the positions of the magnetic member supports 5a and 5b are adjusted in a direction in which the natural frequency of the pendulum member 2 coincides with the natural frequency of the building 20 as the object to be damped. By performing this operation at a preset timing, such as a preset fixed period, it is possible to eliminate deviations in the natural frequency due to changes over time.

[0105] (Variation 3) In the above embodiment, the pendulum device 1 in which the pendulum member 2 performs pendulum motion within one vertical plane has been described, but the present invention is not limited to this. For example, it may be configured so that the pendulum moves within two perpendicular vertical planes. In this case, for example, a mechanism for supporting the support mechanism 31 is provided between the support mechanism 31 and the support body 6 shown in Fig. 2 so that the pendulum member 2 moves in a vertical plane perpendicular to the vertical plane in which the pendulum member 2 moves, with an axis provided on the support body 6 as the fulcrum, and the support mechanism 31 is caused to move in a pendulum motion in a vertical plane perpendicular to the vertical plane in which the pendulum member 2 moves in a pendulum motion with the axis 32 as the fulcrum. Then, the pendulum member 2 is provided with the pendulum side magnetic members 22a, 22b, and a pair of pendulum side magnetic members formed similarly to the pendulum side magnetic members 22a, 22b are provided on a plane perpendicular to the pendulum side magnetic members 22a, 22b, and further, a pair of fixed magnetic members formed similarly to the fixed magnetic members 4a, 4b are provided at positions facing the pair of pendulum side magnetic members.

[0106] As a result, the pendulum member 2 performs a pendulum motion in two mutually perpendicular vertical planes, making it possible to realize a vibration damping device that damps vibrations along the pendulum motion of the pendulum member. In this case as well, as in the above embodiment, a restoring force due to magnetic force can be generated along two vertical planes, making it possible to obtain the same effects as in the above embodiment. Even if the pendulum member 2 performs pendulum motion in three or more vertical planes, the same effect as described above can be obtained by providing pendulum side magnetic members 22a, 22b and fixed magnetic members 4a, 4b for each vertical plane.

[0107] (Variation 4) In a pendulum device that performs conical pendulum motion, the nonlinear components of the conical pendulum motion can also be removed. When applied to a pendulum device 101 that performs conical pendulum motion, as shown in Fig. 12, for example a pivot is used to support the pendulum member 102 so that it can swing around the fulcrum Q. Then, a pendulum-side magnetic member 122, for example a permanent magnet, is disposed on the end of the pendulum member 102 opposite the fulcrum Q. The permanent magnet as the pendulum-side magnetic member 122 is magnetized with a north pole on one end in the longitudinal direction and a south pole on the other end, and is disposed so that one pole of the permanent magnet, for example the north pole, is on the fulcrum Q side and the south pole is on the opposite side to the fulcrum Q.

[0108] On the other hand, for example, a sheet-shaped permanent magnet is used as the fixed magnetic member 104, and this fixed magnetic member 104 is arranged horizontally below the pendulum-side magnetic member 122. At this time, the surface of the fixed magnetic member 104 facing the pendulum-side magnetic member 122 is arranged as an S pole so as to repel the pendulum-side magnetic member 122, and the other surface is arranged as an N pole.

[0109] The magnetic force taking into consideration only the magnetic pole (fixed magnetic member 104) of the surface facing the pendulum side magnetic member 122 can be expressed as follows. (a) First, as shown in FIG. 13, a case will be described where the magnetic pole face of the fixed magnetic member 104 is sufficiently wide, that is, where the pendulum-side magnetic member 122 always faces the fixed magnetic member 104 regardless of the magnitude of the displacement angle θ from the stationary state of the pendulum member 102. The restoring force F of the pendulum member 102 due to the magnetic force can be approximated as shown in the following equation (26). In equation (26), k is a constant consisting of magnetic permeability and magnetic flux density. In equation (26), l is the equivalent length of the pendulum, which is the distance from the fulcrum Q to the center of gravity of the pendulum-side magnetic member 122. d is the distance from the center of gravity of the pendulum-side magnetic member 122 to the magnetized surface of the S pole of the fixed magnetic member 104 when in a stationary state. The distance from the fulcrum Q to the magnetized surface of the S pole of the fixed magnetic member 104 is "l+d."

[0110]

number

[0111] On the other hand, the restoring force of the pendulum member 102 due to gravity can be approximated as shown in the following equation (27). In equation (27), m is the mass of the pendulum member 102, l is the equivalent length of the pendulum, and is the distance from the fulcrum Q to the center of gravity of the pendulum-side magnetic member 122. θ is the displacement angle of the pendulum member 102 from the stationary state, and θ" is the angular acceleration of the displacement angle θ. In the case of the configuration shown in Fig. 13, the restoring force F due to the magnetic force is directed vertically upward.

[0112]

number

[0113] In equation (27), the coefficient of the first-order term, "-(k / d 2 )" represents the linear component, and "-(kl / d 3 )" represents the nonlinear component. Here, the linear component a 1 =-(k / d 2 ), nonlinear component a 3 =-(kl / d 3 ), the linear component a 1 and the nonlinear component a 3 Relative to a 3 / a 1 is expressed by the following equation (28).

[0114]

number

[0115] Therefore, it can be seen that by making "l" larger than "d", it is easier to obtain a nonlinear effect of magnetic force.

[0116] (b) Next, as shown in FIG. 14, a configuration will be described in which the magnetic pole surface of the fixed magnetic member 104 is not sufficiently wide, that is, when the displacement angle θ from the stationary state of the pendulum member 102 is small, the pendulum side magnetic member 122 and the fixed magnetic member 104 face each other, but when the displacement angle θ is large, the pendulum side magnetic member 122 and the fixed magnetic member 104 do not face each other. In this case, the restoring force of the pendulum member 102 due to gravity can be approximated as shown in the following equation (29). In equation (29), m is the mass of the pendulum member 102, l is the equivalent length of the pendulum, θ is the displacement angle of the pendulum member 102 from a stationary state, and θ" is the angular acceleration of the displacement angle θ. k is a constant consisting of magnetic permeability and magnetic flux density. In equation (29), d is the distance from the center of gravity of the pendulum-side magnetic member 122 to the center of the thickness of the fixed magnetic member 104 when in a stationary state. The distance from the fulcrum Q to the center of the thickness of the fixed magnetic member 104 is "l+d". In the case of the configuration shown in FIG. 14, the restoring force F due to the magnetic force is in an obliquely upward direction as shown in the figure.

[0117]

number

[0118] In equation (29), the linear component a 1 =(kd+kl) / d 3 , the nonlinear component a 3 =(k(d+l)(d 2 +9dl+9l 2 )) / 6d 5 Then, the linear component a 1 and the nonlinear component a 3 Relative to a 3 / a 1 is expressed by the following equation (30).

[0119]

number

[0120] Therefore, it can be seen that it is easier to obtain a nonlinear effect of magnetic force by making "l" larger than "d". 12 is a schematic diagram showing an example of a pendulum device 101 that performs conical pendulum motion. In Fig. 12 to Fig. 14, a pendulum member 102 corresponds to the pendulum member 2 in the above embodiment, a fixed magnetic member 104 corresponds to the fixed magnetic members 4a and 4b, and a pendulum-side magnetic member 122 corresponds to the pendulum-side magnetic members 22a and 22b.

[0121] (Variation 5) In the pendulum device 101 performing conical pendulum motion shown in FIG. 12, instead of the sheet-shaped fixed magnetic member 104, a cylindrical radially anisotropic magnet can be used as the fixed magnetic member 104a as shown in FIG. 12, the pendulum member 102 is supported by, for example, a pivot so as to be able to swing about a fulcrum Q, and a pendulum-side magnetic member 122 made of a permanent magnet or the like is disposed on the end of the pendulum member 102 opposite the fulcrum Q. The permanent magnet is magnetized with a north pole at one end in the longitudinal direction and a south pole at the other end, and is disposed so that, for example, the north pole is on the fulcrum Q side and the south pole is on the opposite side to the fulcrum Q. A cylindrical radially anisotropic magnet is disposed as the fixed magnetic member 104a. The magnetic pole on the cylindrical inner surface of the fixed magnetic member 104a is an S pole that repels the pendulum-side magnetic member 122, and the magnetic pole on the outer surface is an N pole.

[0122] Since the magnetization of the south pole is not strictly isotropic, it is not guaranteed that the pendulum member 102 will stably point vertically downward. However, due to the effect of gravity, the pendulum member 102 will extend vertically when stationary. In this case, as in the case where the pendulum member 2 described in the above embodiment performs simple pendulum motion in a vertical plane, the nonlinear component of the restoring force of the pendulum member 102 in conical pendulum motion can be removed by adjusting the restoring force due to magnetic force and utilizing the nonlinear effect of magnetic force.

[0123] Furthermore, in the fourth and fifth modified examples, the pendulum member 102 is supported swingably using a pivot to cause a conical pendulum motion, but it may also be configured to cause a spherical pendulum motion. In addition, in the fourth and fifth modified examples, the pendulum member 102 and the fixed magnetic members 104 and 104a have different polarities, but it is also possible to make them the same polarity.

[0124] (Variation 6) In the above embodiment, the external shapes of the pendulum side magnetic member and the fixed magnetic member may be any of cylindrical, columnar, spherical, arc-shaped, ring-shaped, hollow cylindrical, curved, and flat shapes. The pendulum side magnetic member and the fixed magnetic member do not have to have the same external shape, and it is preferable that they have a shape that generates the required repulsive or attractive force. In the above embodiment, the pendulum body 21 is not limited to a thin plate, but may be made of any material having rigidity. For example, the pendulum side magnetic members 22a and 22b themselves may be used as the pendulum body 21 without providing a separate pendulum body 21.

[0125] Furthermore, the pendulum-side magnetic members 22a, 22b do not necessarily have to be provided at the tip of the pendulum body 21, and are preferably provided at positions where they can generate the required repulsive or attractive force. The same applies to the fixed magnetic members 4a, 4b. Without providing separate magnetic member support parts 5a, 5b, the fixed magnetic members 4a, 4b themselves may be used as the magnetic member support parts 5a, 5b, and the positioning positions of the fixed magnetic members 4a, 4b are not limited to the tips of the magnetic member support parts 5a, 5b. The pendulum side magnetic members 22a, 22b and the fixed magnetic members 4a, 4b may be in any position and have any size (length) that can generate the required repulsive or attractive force.

[0126] (Variation 7) In the above embodiment, the case has been described where the pendulum device 1 in which the pendulum member 2 is suspended and causes pendulum motion is applied as the vibration damping device 10, but the present invention is not limited to this. When the pendulum member 2 is suspended and caused to perform pendulum motion, the direction in which the pendulum member 2 extends is vertical when at rest. However, as shown in FIG. 16, one end of the pendulum member can be attached to a wall surface or the like of an object to be damped, so that when at rest the pendulum member is in a horizontal position and the pendulum moves with the horizontal position as the reference, and such a pendulum device can be used as a vibration damping device. Note that Figure 16 and Figures 17 to 22 described below are schematic diagrams of a pendulum device, and as in the above embodiment, one end of the pendulum member is attached to the object to be damped so that the pendulum member performs pendulum motion as the object to be damped vibrates, and the fixed magnetic member is positioned so as to vibrate integrally with the object to be damped as the object vibrates.

[0127] 16(a) shows a pendulum device 201 in which one end of a pendulum member 202 is attached to a wall surface or the like of an object to be vibration-damped 220 so that it can perform pendulum motion in a vertical plane, and the movable end side of the pendulum member 202 performs pendulum motion in the vertical plane as the object to be vibration-damped 220 vibrates up and down. In FIG. 16, the downward direction is the Z axis, the left direction is the X axis, the direction toward the paper surface is the Y axis, and the Z axis direction is the direction of gravity.

[0128] A pendulum-side magnetic member 222 is attached to the end of the pendulum member 202 opposite the object of vibration damping 220. The point on the object of vibration damping 220 to which one end of the pendulum member 202 is attached serves as a fulcrum Q, and the pendulum member 202 has the rigidity to maintain a horizontal state as a stable equilibrium state. As the vibration damping target 220 vibrates up and down, the pendulum member 202 performs a pendulum motion about a fulcrum Q as an axis, and the pendulum side magnetic member 222 is configured to move along an arc within a vertical plane.

[0129] The fixed magnetic member 204 is disposed on an extension of the horizontal pendulum member 202 in the extending direction, and is disposed so as to vibrate integrally with the vibration-damping target 220. The fixed magnetic member 204 and the pendulum-side magnetic member 222 are magnetized so that the magnetic poles of the opposing faces are opposite to each other. As a result, when the vibration-damping target 220 is not vibrating, the pendulum member 202 is maintained in a horizontal state by the attractive force between the fixed magnetic member 204 and the pendulum-side magnetic member 222, and when the amplitude of the pendulum member 202 from the horizontal state is within a certain range, the pendulum member 202 performs pendulum motion by the attractive force between the pendulum-side magnetic member 222 and the fixed magnetic member 204. When the object 220 to be damped vibrates in the Z-axis direction in FIG. 16 from a horizontal state in which the pendulum member 202 is stationary, the pendulum member 202 performs pendulum motion in the ZX plane with the fulcrum Q as the axis in response to the vibration of the object 220 to be damped.

[0130] In this case as well, the restoring force due to gravity and the restoring force due to magnetic force act on the pendulum member 202, and the nonlinear component of the restoring force due to gravity and the nonlinear component of the restoring force due to magnetic force cancel each other out, so that the pendulum member 202 as a whole has a linear restoring force, regardless of the magnitude of the amplitude of the pendulum member 202. This makes it possible to suppress the nonlinear component of the force acting due to gravity on the pendulum member 202 performing pendulum motion.

[0131] FIG. 17(b) shows the pendulum device 201 in FIG. 16, where two fixed magnetic members 204 are provided. 16, in the pendulum device 201 shown in Fig. 17, the pendulum member 202 is arranged so as to perform pendulum motion in the ZX plane with the fulcrum Q as the axis as the object of vibration control 220 vibrates up and down. In addition, fixed magnetic members 204a and 204b are arranged above and below the pendulum member 202, which is horizontal in a stationary state, and these fixed magnetic members 204a, 204b are arranged so as to vibrate integrally with the object of vibration control 220. The fixed magnetic members 204a and 204b are arranged to face the pendulum side magnetic member 222 which is arranged at the movable end of the pendulum member 202 which is in a horizontal state, and the surface of the pendulum side magnetic member 222 facing the fixed magnetic member 204a and the surface facing the fixed magnetic member 204b are magnetized with opposite polarities, the surfaces where the fixed magnetic member 204a and the pendulum side magnetic member 222 face each other are magnetized to have the same polarity, and the surfaces where the fixed magnetic member 204b and the pendulum side magnetic member 222 face each other are magnetized to have the same polarity.

[0132] As a result, when the vibration-damping object 220 is not vibrating, the pendulum member 202 is maintained in a horizontal state by the repulsive force between the fixed magnetic member 204a and the pendulum side magnetic member 222, the repulsive force between the fixed magnetic member 204b and the pendulum side magnetic member 222, and gravity, and when the amplitude of the pendulum member 202 from the horizontal state is within a certain range, the pendulum member 202 is configured to perform pendulum motion by the repulsive force between the pendulum side magnetic member 222 and the fixed magnetic members 204a, 204b. When the object 220 to be damped vibrates in the Z-axis direction in FIG. 17 from a horizontal state in which the pendulum member 202 is stationary, the pendulum member 202 performs pendulum motion in the ZX plane with the fulcrum Q as the axis in response to the vibration of the object 220 to be damped.

[0133] In this case as well, the restoring force due to gravity and the restoring force due to magnetic force act on the pendulum member 202, and the nonlinear component of the restoring force due to gravity and the nonlinear component of the restoring force due to magnetic force cancel each other out, so that the restoring force of the pendulum member 202 as a whole has a linear component, and the restoring force is linear regardless of the magnitude of the amplitude of the pendulum member 202. This makes it possible to suppress the nonlinear component contained in the restoring force due to gravity of the pendulum member 202 performing pendulum motion. 16 and 17, the pendulum member 202 corresponds to the pendulum member 2 in the above embodiment, the fixed magnetic members 204, 204a, and 204b correspond to the fixed magnetic members 4a and 4b, and the pendulum side magnetic member 222 corresponds to the pendulum side magnetic members 22a and 22b.

[0134] 18(c) shows a pendulum device 201 in FIG. 16 in which an object to be vibration-damped 220 to which a pendulum member 202 is attached vibrates in the Y-axis direction, thereby causing the movable end of the pendulum member 202 to vibrate in the XY plane. 18, the left direction is the X-axis, the upward direction is the Y-axis, the direction toward the paper surface is the Z-axis, and the Z-axis direction is the direction of gravity. That is, FIG 18 is a view of the pendulum device 201 as seen from above. The magnetic poles of the facing surfaces of the fixed magnetic member 204 and the pendulum side magnetic member 222 are opposite to each other.

[0135] The pendulum member 202 has rigidity to maintain a constant distance between the fulcrum Q and the pendulum side magnetic member 222, and is configured so that as the vibration control object 220 vibrates in a horizontal plane, the pendulum member 202 performs a pendulum motion around the fulcrum Q as its axis, and the pendulum side magnetic member 222 moves along an arc in the horizontal plane. The fixed magnetic member 204 is disposed on the longitudinal extension of the pendulum member 202 that is perpendicular to the vertical plane including the fulcrum Q of the vibration damping object 220, and is disposed so as to vibrate integrally with the vibration damping object 220. The fixed magnetic member 204 and the pendulum side magnetic member 222 are magnetized to have opposite poles.

[0136] As a result, when the object to be vibration-controlled 220 is not vibrating, the pendulum member 202 is in a horizontal state, and further, due to the attractive force between the fixed magnetic member 204 and the pendulum side magnetic member 222, the pendulum member 202 is maintained in a state perpendicular to a plane including the fulcrum Q of the object to be vibration-controlled 220 in the horizontal plane; when the object to be vibration-controlled 220 vibrates and the amplitude in the horizontal plane is within a certain range, the pendulum member 202 is configured to perform pendulum motion due to the attractive force between the pendulum side magnetic member 222 and the fixed magnetic member 204. When the pendulum member 202 is at rest and is vertical and horizontal to a vertical plane including the fulcrum Q of the vibration-damping target 220, and the vibration-damping target 220 vibrates in the horizontal direction, a restoring force due to the magnetic force acts on the pendulum member 202, causing the pendulum member 202 to perform pendulum motion in the XY plane with the fulcrum Q as its axis. In this case, gravity does not act on the pendulum member 202, so the restoring force characteristic of the pendulum device 201 becomes a soft spring characteristic.

[0137] 19(d) shows a pendulum device 201 in FIG. 17, in which an object to be vibration-damped 220 to which a pendulum member 202 is attached vibrates in the Y-axis direction, thereby causing the movable end of the pendulum member 202 to vibrate in the XY plane. 18, in the pendulum device 201 shown in Fig. 19, the pendulum member 202 is arranged so as to perform pendulum motion in a horizontal plane with the fulcrum Q as an axis as the object of vibration control 220 vibrates in the horizontal direction. In addition, fixed magnetic members 204a, 204b are arranged on either side of the pendulum member 202 in the horizontal plane, which is in a stationary state horizontally intersecting at right angles to the vertical plane including the fulcrum Q of the object of vibration control 220, and these fixed magnetic members 204a, 204b are arranged so as to vibrate integrally with the object of vibration control 220. The surface of the pendulum side magnetic member 222 facing the fixed magnetic member 204a and the surface facing the fixed magnetic member 204b are magnetized with opposite polarities, the surfaces where the fixed magnetic member 204a and the pendulum side magnetic member 222 face each other are magnetized to have the same polarity, and the surfaces where the fixed magnetic member 204b and the pendulum side magnetic member 222 face each other are magnetized to have the same polarity.

[0138] As a result, when the vibration-damping object 220 is not vibrating, the pendulum member 202 is maintained in a horizontal state by the repulsive force between the fixed magnetic member 204a and the pendulum side magnetic member 222 and the repulsive force between the fixed magnetic member 204b and the pendulum side magnetic member 222, and is further maintained in a state perpendicular to the vertical plane including the fulcrum Q; when the amplitude of the pendulum member 202 from the horizontal state is within a certain range, the pendulum member 202 is configured to perform pendulum motion by the repulsive force between the pendulum side magnetic member 222 and the fixed magnetic members 204a, 204b. 19, when the pendulum member 202 is stationary and the object to be vibration-damped 220 vibrates in the Y-axis direction in Fig. 19, the pendulum member 202 performs pendulum motion in the XY plane around the fulcrum Q as the object to be vibration-damped 220 vibrates. In this case, since gravity does not act on the pendulum member 202, the pendulum device 201 has hard spring characteristics.

[0139] 18 and 19, the pendulum member 202 corresponds to the pendulum member 2 in the above embodiment, the fixed magnetic members 204, 204a, and 204b correspond to the fixed magnetic members 4a and 4b, and the pendulum side magnetic member 222 corresponds to the pendulum side magnetic members 22a and 22b.

[0140] 16, the pendulum device 201 has a pendulum member 202 attached to an object 220 to be vibration-damped, which vibrates in the X-axis direction, causing the movable end of the pendulum member 202 to vibrate in the ZX plane. In Fig. 20, the left direction is the Z-axis, the upward direction is the X-axis, the direction toward the paper surface is the Y-axis, and the Z-axis direction is the direction of gravity. In other words, the pendulum device 201 shown in Fig. 20 is a pendulum device in which the pendulum member 202 is suspended from the object 220 to be vibration-damped. In this case, the magnetic poles of the facing surfaces of the fixed magnetic member 204 and the pendulum side magnetic member 222 may be different or the same.

[0141] The pendulum member 202 has rigidity to maintain a constant distance between the fulcrum Q and the pendulum side magnetic member 222, and is configured so that as the vibration control object 220 vibrates in a horizontal plane, the pendulum member 202 performs a pendulum motion around the fulcrum Q as its axis, and the pendulum side magnetic member 222 moves in an arc in a vertical plane. The fixed magnetic member 204 is disposed on an extension of the pendulum member 202, which is in a stationary state with one end attached to a fulcrum Q of the vibration-damping object 220 and suspended, so as to vibrate integrally with the vibration-damping object 220. The fixed magnetic member 204 and the pendulum-side magnetic member 222 are magnetized, for example, to have opposite poles. As a result, when the vibration-damping object 220 is not vibrating, the pendulum member 202 is maintained in a vertical state by gravity and the attractive force between the fixed magnetic member 204 and the pendulum-side magnetic member 222.

[0142] When the object 220 to be damped vibrates in the horizontal direction from a state in which the pendulum member 202 is stationary and vertical, the pendulum member 202 accordingly performs a pendulum motion in the ZX plane with the fulcrum Q as the axis. In the case of opposite poles, the restoring force due to the magnetic force acts on the pendulum member 202, and the nonlinear component due to gravity and the nonlinear component due to the magnetic force cannot cancel each other out, so that although the pendulum member 202 as a whole has a linear restoring force, the resultant force acting on the pendulum due to gravity and magnetic force increases in nonlinear soft spring characteristics in proportion to the pendulum angle.

[0143] In addition, when the magnetic poles of the facing surfaces of the fixed magnetic member 204 and the pendulum-side magnetic member 222 are the same, in a state where the object of vibration damping 220 is not vibrating, if the magnitude of the linear component of the force acting on the pendulum due to gravity is greater than the linear component of the repulsive force due to the magnetic force, the pendulum member 202 is maintained in a stationary state facing vertically downward, and in a state where the amplitude of the pendulum member 202 facing vertically downward is within a certain range, the pendulum member 202 is configured to perform pendulum motion. As a result, when the facing surfaces of the fixed magnetic member 204 and the pendulum-side magnetic member 222 are the same polarity, a restoring force consisting of the sum of the restoring force due to gravity and the restoring force due to the magnetic force exists, so that the nonlinear components contained in each restoring force can be offset, and the pendulum member 202 as a whole can have linear restoring force characteristics without nonlinearity.

[0144] 21(f) shows a pendulum device 201 in FIG. 17 in which an object to be vibration-damped 220 to which a pendulum member 202 is attached vibrates in the X-axis direction, thereby causing the movable end of the pendulum member 202 to vibrate in the ZX plane. In this case, the magnetic poles of the fixed magnetic members 204a and 204b and the magnetic member 222 on the pendulum side facing each other may be the same or different. An example of the same polarity is the pendulum device 1 shown in FIG. The pendulum member 202 has rigidity to maintain a constant distance between the fulcrum Q and the pendulum side magnetic member 222, and is configured so that as the vibration control object 220 vibrates in a horizontal plane, the pendulum member 202 performs a pendulum motion around the fulcrum Q as its axis, and the pendulum side magnetic member 222 moves in an arc in a vertical plane.

[0145] The fixed magnetic members 204a and 204b are arranged on the extension of the pendulum member 202, which is in a stationary state with one end attached to and suspended from a fulcrum Q of the vibration-damping object 220, and are arranged so as to vibrate integrally with the vibration-damping object 220. The fixed magnetic member 204a and the pendulum-side magnetic member 222 are magnetized, for example, to have the same polarity, and similarly, the fixed magnetic member 204b and the pendulum-side magnetic member 222 are magnetized to have the same polarity. This allows the pendulum member 202 to be maintained in a vertical state by gravity and the repulsive force between the fixed magnetic members 204a and 204b and the pendulum-side magnetic member 222 when the vibration-damping object 220 is not vibrating.

[0146] When the object 220 to be damped vibrates in the horizontal direction from a state in which the pendulum member 202 is stationary and vertical, the pendulum member 202 accordingly performs a pendulum motion in the ZX plane with the fulcrum Q as the axis. In the case of the same polarity, the restoring force due to magnetic force acts on the pendulum member 202, and by setting parameters such as the distance between the magnets when they are stationary and facing vertically downward and the thickness of the magnets, the nonlinear component of the restoring force due to gravity and the nonlinear component of the magnetic force are offset, so that the pendulum member 202 as a whole has a linear restoring force, and the restoring force is linear regardless of the magnitude of the amplitude of the pendulum member 202.

[0147] On the other hand, when the magnetic poles of the facing surfaces of the fixed magnetic members 204a, 204b and the pendulum-side magnetic member 222 are opposite, the restoring force due to gravity is made greater than the linear component of the attractive force due to the magnetic force when the vibration-damping target 220 is not vibrating, so that the pendulum member 202 is configured to maintain a stationary state facing vertically downward. When the facing surfaces of the fixed magnetic members 204a, 204b and the pendulum-side magnetic member 222 are opposite, a restoring force consisting of the sum of the restoring force of gravity and the linear component of the magnetic force exists, and the pendulum member 202 can be made to perform pendulum motion in response to the vibration of the vibration-damping target 220, but in this case, the nonlinear component cannot be offset, resulting in an increase in the soft spring characteristic. Here, the restoring force characteristics of the pendulum device 201 differ depending on whether the magnetic poles on the opposing surfaces of the fixed magnetic members 204a, 204b and the pendulum side magnetic member 222 are opposite or the same polarity; if they are the same polarity, a soft spring characteristic results, and if they are opposite polarity, a hard spring characteristic results. Therefore, depending on the desired characteristics, it is sufficient to determine whether the magnetic poles on the opposing surfaces of the fixed magnetic members 204a, 204b and the pendulum side magnetic member 222 are opposite or the same polarity.

[0148] (Variation 8) For example, by combining the pendulum device 201 shown in FIG. 16 with the pendulum device 201 shown in FIG. 17, pendulum side magnetic members 222a, 222b may be provided on both ends of the pendulum member 202 as shown in FIG. 22 to form a pendulum device 301 having a fulcrum Q at the longitudinal middle portion of the pendulum member 202. For example, the pendulum member 202 is formed of two pendulum members connected by supporting one end of a first pendulum member and one end of a second pendulum member (not shown) so that they can freely rotate about a fulcrum Q, and the pendulum side magnetic member 222a side and the pendulum side magnetic member 222b side can vibrate independently with the fulcrum Q as an axis.

[0149] 22, a pendulum-side magnetic member (first magnetic member) 222a is provided at one end of the pendulum member 202. A fixed magnetic member (second magnetic member, first fixed member) 204 is provided at a position facing the pendulum-side magnetic member 222a on the extension of the pendulum member 202 in a horizontal state (stationary state). The magnetic poles of the opposing surfaces of the pendulum-side magnetic member 222a and the fixed magnetic member 204 are opposite to each other so that an attractive force is generated.

[0150] Moreover, a pendulum-side magnetic member (third magnetic member) 222b is provided at the other end, and fixed magnetic members (fourth magnetic member, second fixed member) 204a and 204b are provided on both sides of the pendulum-side magnetic member 222b. The magnetic pole of the surface of the pendulum-side magnetic member 222b facing 204a and the magnetic pole of the surface facing 204b are different poles, the magnetic pole of the surface where the pendulum-side magnetic member 222b and the fixed magnetic member 204a face each other are the same pole, and the magnetic pole of the surface where the pendulum-side magnetic member 222b and the fixed magnetic member 204b face each other are the same pole, so that they repel each other.

[0151] In this way, pendulum A on the left end side of pendulum member 202 and pendulum B on the right end side are configured to operate in conjunction with or independently, and the arrangement of the magnetic members is made different, for example, pendulum A is configured to have soft spring characteristics, and pendulum B is configured to have hard spring characteristics. By configuring so that the magnetic forces acting on pendulum A and pendulum B can be adjusted separately, and adjusting either or both of the magnetic forces acting on pendulum A and pendulum B according to the desired characteristics, the linear restoring force and the nonlinear restoring force can be set independently.

[0152] (Variation 9) The object to be damped is not limited to the building 20, but may be, for example, a moving object such as a train, a bridge, a pier, or a pipe.

[0153] (a) When the pendulum device according to this embodiment is attached to a pipe as a vibration absorber, for example, as shown in Fig. 23(a) and (b), when the pipe 320 vibrates in the vertical direction, the pendulum device 201 shown in Fig. 16 or 17 is used, and the pendulum device 201 is disposed on the side of the pipe 320 so that the pendulum member 202 in a stationary state extends in the X-axis direction of the pipe 320 in Fig. 23, and the pendulum device 201 is provided so that the pendulum member 202 performs pendulum motion in the ZX plane in response to the vertical vibration of the pipe 320. In Fig. 23(a), the left direction is the Y-axis, the direction toward the front of the paper is the X-axis, the downward direction is the Z-axis, and the Z-axis direction is the direction of gravity. Fig. 23(b) is a view of the pipe 320 in Fig. 23(a) as seen from the Y-axis direction.

[0154] 24(a) and 24(b), when the pipe 320 vibrates in the horizontal direction, the pendulum device 201 shown in FIG. 18 or 19 is used, and the pendulum device 201 is disposed under the pipe 320 so that the pendulum member 202 in the stationary state extends in the Z-axis direction of the pipe 320 in FIG. 24, and the pendulum device 201 is provided so that the pendulum member 202 performs pendulum motion in the ZX plane in response to the horizontal vibration of the pipe 320. In FIG. 24(a), the left direction is the Y-axis, the upward direction is the X-axis, the direction toward the paper is the Z-axis, and the Z-axis direction is the direction of gravity. FIG. 24(b) is a view of the pipe 320 shown in FIG. 24(a) as seen from the Y-axis direction.

[0155] (b) When the pendulum device according to this embodiment is attached to a train car as a vibration absorber, as shown in Fig. 25(a) and (b), in the case of vibration in the left-right direction in the running direction of the car 420, the pendulum device 201 shown in Fig. 18 or 19 may be used in the same manner as in the case of suppressing horizontal vibration of the pipe 320 shown in Fig. 24, and the pendulum device 201 may be arranged on the ceiling or the like inside the car so that the pendulum member 202 in the stationary state extends below the car in Fig. 25, and the pendulum device 201 may be provided so that the movable part of the pendulum member 202 vibrates in the left-right direction in the running direction of the car relative to the car 420 within a vertical plane. By arranging in this manner, it is possible to stabilize the vibration in the left-right direction in the running direction of the car 420.

[0156] Furthermore, for example, when the pendulum device according to this embodiment is attached to a bridge as a vibration control device to suppress the vertical vibration of the bridge, similarly to the case of suppressing the vertical vibration of the pipe 320 shown in Fig. 23, the pendulum device 201 shown in Fig. 16 or 17 may be used and provided so that the pendulum member 202 performs pendulum motion in a vertical plane in response to the vertical vibration of the bridge. In this case, when the natural frequency of the bridge is Ω, it is preferable to set the natural frequency ω of the pendulum member 2 so that ω = Ω / 2.

[0157] (Variation 10) It is also possible to enhance the nonlinearity of the pendulum device according to this embodiment and apply it to an energy harvester. Usually, the harvester resonates and can extract energy only when the excitation frequency γ is close to the natural frequency ω of the harvester (oscillator, here the pendulum member). That is, as shown in Fig. 26, energy can be extracted only when the excitation frequency γ is within a limited range. By using the pendulum device of this embodiment and adjusting the characteristics of the pendulum member to have soft spring characteristics or hard spring characteristics, a resonant state can be reached over a wider range of excitation frequencies γ, as shown in Figure 27, making it possible to efficiently operate the energy harvester.

[0158] In order to obtain the characteristics shown in Fig. 27, a pendulum device having both hard spring characteristics and soft spring characteristics is required. For example, the pendulum device 301 shown in Fig. 22 described in Modification Example 8 can be used. In Fig. 22, pendulum A has soft spring characteristics, and pendulum B has hard spring characteristics. By independently adjusting the distance between the magnets in each of pendulums A and B, the nonlinear characteristics of the pendulum can be set more freely.

[0159] For example, when the excitation frequency γ is smaller than the linear natural frequency ω of the pendulum device 301, the electromagnet of pendulum A having soft spring characteristics is activated, and the electromagnet of pendulum B is stopped. Conversely, when the excitation frequency γ is larger than the linear natural frequency ω of the pendulum device 1, the electromagnet of pendulum A is stopped, and the electromagnet of pendulum B having hard spring characteristics is activated. This allows the energy harvester to operate over a wider range of excitation frequencies γ, as shown in Fig. 27. The pendulum device 301 shown in FIG. 22 may be disposed so as to vibrate in the same direction as the vibration direction of the object to be damped.

[0160] Also, the present invention is not limited to the pendulum device 301 shown in Fig. 22, and other pendulum devices may be applied to the energy harvester. For example, as shown in Fig. 25, a pendulum device may be attached to a vehicle, and a pendulum member may be caused to perform a pendulum motion in response to the left and right swing of the vehicle relative to the traveling direction, and the vibration may be converted into electric energy. Also, a pendulum device may be provided on a bridge, and a pendulum member may be caused to perform a pendulum motion in response to the up and down swing of the bridge, and the vibration may be converted into electric energy. Also, a pendulum device may be disposed so that the pendulum member performs a pendulum motion due to waves, and the vibration of the pendulum member due to waves may be converted into electric energy.

[0161] As a generator that converts vibration into electrical energy, for example, a piezoelectric type, an electromagnetic induction type, an electrostatic type, or the like can be used. For example, when the pendulum device is attached to a vehicle, as shown in FIG. 25(b), a generator 420a for converting vibration into electric energy may be provided near the fulcrum Q of the pendulum member, and electric energy may be taken out from this.

[0162] <Method of adjusting the arrangement of magnetic members and the motion characteristics of pendulum members> In the pendulum member 102 performing conical pendulum motion shown in Fig. 13 (when the magnetic pole surface of the fixed magnetic member 104 is sufficiently wide), when the extension direction of the pendulum member 102 is vertical as shown in Fig. 28, the distance from the surface of the fixed magnetic member 104 to the center of gravity of the pendulum-side magnetic member 122 is r, the difference between the height of the center of gravity of the pendulum-side magnetic member 122 from the surface of the fixed magnetic member 104 when the displacement angle of the pendulum member 102 from the vertical direction is θ is x, and the distance from the fulcrum Q to the center of gravity of the pendulum-side magnetic member 122 is the equivalent length l of the pendulum. x is expressed by the following equation (31).

[0163]

number

[0164] Moreover, the restoring force F of the pendulum member 102 due to the magnetic force can be approximated as shown in the following equation (32) using equation (31): k in equation (32) is a constant consisting of magnetic permeability and magnetic flux density.

[0165]

number

[0166] On the other hand, the restoring force due to gravity of the pendulum member 102 can be approximated as shown in the following equation (33). In equation (33), m is the mass of the pendulum member 102, and θ″ is the angular acceleration of the displacement angle θ. In the case of the configuration shown in FIG. 28, the restoring force F due to the magnetic force is directed vertically upward.

[0167]

number

[0168] In equation (32), the coefficient of the first-order term, "(k / r 2 ) represents the linear component, and "-(kl / r 3 )" represents the nonlinear component. Here, the linear component a 1 =(k / r 2 ), nonlinear component a 3 =-(kl / r 3 ), the linear component a 1 and the nonlinear component a 3 Relative to a 3 / a 1 is expressed by the following equation (34).

[0169]

number

[0170] Therefore, it can be seen that it is easier to obtain a nonlinear effect by making "l" larger compared to "r". Here, when the opposing surfaces of the pendulum side magnetic member 122 and the fixed magnetic member 104 are of different polarities and attract each other, 1 is a1 >0, it has positive linear stiffness, a 3 is a 3 <0, and the nonlinear stiffness has soft spring characteristics. 1 A 1 >0, a restoring force can be generated. When the opposing surfaces of the pendulum side magnetic member 122 and the fixed magnetic member 104 are of the same polarity and repel each other, 1 is a 1 < 0, it has negative linear stiffness, a 3 is a 3 >0, the nonlinear stiffness has hard spring characteristics. 1 A 1 <0, and the linear stiffness is negative, so the pendulum device cannot have a restoring force.

[0171] In addition, when the restoring force of gravity can be used, for example, in the case of the pendulum device 201 shown in FIG. 1 <0 and have a negative linear stiffness, the effect of gravity can counter this and give an overall positive linear stiffness, in which case there is a restoring force and at the same time a hard spring characteristic of the magnetic member. The same characteristics are also observed in the pendulum member 102 that performs conical pendulum motion as shown in FIG. 14 (when the magnetic pole surface of the fixed magnetic member 104 is not sufficiently wide). 1 and a, which represents the coefficient of the nonlinear component 3 It can be found by the following procedure.

[0172] In the pendulum member 102 shown in Fig. 14, when the extension direction of the pendulum member 102 is vertical as shown in Fig. 29, the vertical distance from the center of gravity of the fixed magnetic member 104 to the center of gravity of the pendulum side magnetic member 122 is r, the distance from the center of gravity of the fixed magnetic member 104 to the center of gravity of the pendulum side magnetic member 122 when the displacement angle of the pendulum member 102 from the vertical direction is θ is x, and the distance from the fulcrum Q to the center of gravity of the pendulum side magnetic member 122 is the equivalent length of the pendulum l. In the configuration shown in Fig. 29, the restoring force F due to the magnetic force is a force in the vector direction extending from the center of gravity of the fixed magnetic member 104 toward the center of gravity of the pendulum side magnetic member 122. The angle formed by the tangent at the position of the center of gravity of the pendulum side magnetic member 122 when the displacement angle is θ on the movement trajectory of the center of gravity of the pendulum side magnetic member 122 when the pendulum member 102 moves in a pendulum motion is defined as α.

[0173] The restoring force F of the pendulum member 102 due to the magnetic force can be expressed by the following equation (35): k in equation (35) is a constant consisting of magnetic permeability and magnetic flux density.

[0174]

number

[0175] Moreover, from equation (35), the approximation equation shown in the following equation (36) can be derived.

[0176]

number

[0177] On the other hand, the restoring force of the pendulum member 102 due to gravity can be approximated as shown in the following equation (37): In equation (37), m is the mass of the pendulum member 102, and θ″ is the angular acceleration of the displacement angle θ.

[0178]

number

[0179] In equation (36), the coefficient of the first-order term, "(kl+kr)θ / r 3 " represents the linear component, and "-k(r+l)(r 2 +9rl+9l 2 )θ 3 / 6r 3 " represents the nonlinear component. Here, the linear component a1 = (kl + kr) / r 3 , the nonlinear component a3 = -k(r+l)(r 2 +9rl+9l 2 ) / 6r 3 Then, the ratio a3 / a1 of the linear component a1 to the nonlinear component a3 is expressed by the following equation (38).

[0180]

number

[0181] Therefore, it can be seen that by making "l" larger than "r", it is easier to obtain a nonlinear effect of magnetic force. The scope of the present invention is not limited to the exemplary embodiments shown and described, but includes all embodiments that achieve equivalent effects to those intended by the present invention. Moreover, the scope of the present invention may be defined by any desired combination of specific features among all the respective features disclosed.

[0182] The present invention can have the following configurations, for example.

[0183] (1) A pendulum member that performs pendulum motion around a fulcrum and is at least partially constituted by a first magnetic member; a fixed member that applies a magnetic repulsive or attractive force to the pendulum member and is at least partially constituted by a second magnetic member; A pendulum device comprising:

[0184] (2) The pendulum device according to (1) above, wherein the pendulum member is rotatably suspended from the fulcrum.

[0185] (3) The pendulum device according to (1) or (2) above, wherein the pendulum motion is any one of simple pendulum motion, spherical pendulum motion, and conical pendulum motion.

[0186] (4) The pendulum device described in (1) above is characterized in that the pendulum member has rigidity, is capable of simple pendulum motion in a vertical plane centered on the fulcrum, and is maintained in a horizontal state when in a stationary state by the repulsive or attractive force between the first magnetic member and the second magnetic member.

[0187] (5) The pendulum device described in (1) above is characterized in that the pendulum member has rigidity, is capable of simple pendulum motion within a horizontal plane centered on the fulcrum, and when in a stationary state, is maintained in a vertical state relative to a vertical plane that includes the fulcrum and is perpendicular to the horizontal plane due to the repulsive or attractive force between the first magnetic member and the second magnetic member.

[0188] (6) the pendulum motion is a simple pendulum motion, the second magnetic members are a pair, and the pair of second magnetic members are arranged facing each other with the pendulum member therebetween in the motion direction of the simple pendulum motion, The pendulum device described in any one of (1) to (5) above, characterized in that the first magnetic member is arranged for each of the second magnetic members so as to face each of the second magnetic members.

[0189] (7) the second magnetic member is disposed so as to surround the pendulum member, The pendulum device described in any one of (1) to (3) above, characterized in that the first magnetic member and the second magnetic member are arranged so that the magnetic poles on the sides facing each other are the same pole or opposite poles.

[0190] (8) The pendulum device according to any one of (1) to (7) above, wherein the first magnetic member and the second magnetic member are each constituted by a permanent magnet or an electromagnet.

[0191] (9) The pendulum device described in any one of (1) to (8) above, characterized in that the external shapes of the first magnetic member and the second magnetic member are each one of a cylindrical shape, a rectangular prism shape, a spherical shape, an arc shape, a ring shape, a hollow cylindrical shape, a curved shape, and a flat shape.

[0192] (10) The second magnetic member has a flat or curved outer shape, The pendulum device described in any one of (1) to (8) above, characterized in that the first magnetic member and the second magnetic member are arranged so that the magnetic poles on the sides facing each other are the same pole or different poles.

[0193] (11) The pendulum device described in any one of (1) to (10) above, characterized in that at least one of the magnetic flux density of at least one of the first magnetic member and the second magnetic member, the relative position of the first magnetic member and the second magnetic member, and the mass of the pendulum member is adjustable.

[0194] (12) The pendulum device according to any one of (1) to (11) above, wherein the fulcrum is provided directly on the object to be damped or on a structural part fixed to the object to be damped.

[0195] (13) A vibration damping device that damps the vibration of an object to be damped by using a pendulum device that performs pendulum motion, A vibration damping device, characterized in that the pendulum device described in any one of (1) to (12) above is used as the pendulum device.

[0196] (14) A method for designing a vibration damping device that damps vibration of an object to be damped by using a pendulum member that performs pendulum motion, comprising the steps of: A first magnetic member is disposed on at least a portion of the pendulum member; A second magnetic member is disposed at a position where a magnetic repulsive force or an attractive force is applied to the first magnetic member; A method for designing a vibration damping device, comprising adjusting at least one of the magnetic flux densities of the first magnetic member and the second magnetic member, the relative position of the first magnetic member and the second magnetic member, and the mass of the pendulum member so that the sum of the restoring force due to gravity of the pendulum member and the restoring force due to the magnetic force between the first magnetic member and the second magnetic member has desired restoring force characteristics.

[0197] (15) A pendulum member that performs a pendulum motion around a fulcrum and at least a portion of the pendulum member is composed of the first magnetic member; and a first magnetic member is disposed on at least a portion of the pendulum member; A second magnetic member is disposed at a position where a magnetic repulsive force or an attractive force is applied to the first magnetic member; A pendulum device comprising: at least one of the magnetic flux densities of the first magnetic member and the second magnetic member; the relative positions of the first magnetic member and the second magnetic member; and the mass of the pendulum member, adjusted so that the sum of the restoring force due to gravity of the pendulum member and the restoring force due to the magnetic force between the first magnetic member and the second magnetic member has desired restoring force characteristics.

[0198] (16) The pendulum device according to (15) above, wherein the restoring force characteristic is either a linear characteristic, a soft spring characteristic or a hard spring characteristic.

[0199] (17) a first pendulum member that performs pendulum motion around a fulcrum and is at least partially constituted by a first magnetic member; A first fixed member that applies a repulsive force due to a magnetic force to the first pendulum member and is at least partially constituted by a second magnetic member; A second pendulum member that performs pendulum motion about the fulcrum and is at least partially constituted by a third magnetic member; a second fixed member that applies a magnetic attraction force to the second pendulum member, and at least a portion of which is constituted by a fourth magnetic member.

[0200] (18) At least one of the first magnetic member, the second magnetic member, the third magnetic member, and the fourth magnetic member is an electromagnet, The pendulum device described in (17) above, characterized in that at least one of the hard spring characteristics of the first pendulum member due to the repulsive force and the soft spring characteristics of the second pendulum member due to the attractive force can be changed by at least one of changing the magnitude of the magnetic force of the electromagnet and deactivating the electromagnet.

[0201] (19) The pendulum device described in (18) above, characterized in that the first magnetic member and the second magnetic member are each composed of a permanent magnet or an electromagnet, and the third magnetic member and the fourth magnetic member are each composed of a permanent magnet or an electromagnet.

[0202] (20) The pendulum device according to any one of (17) to (19) above, further comprising a generator that converts the vibration of the first pendulum member or the second pendulum member into electrical energy. [Explanation of symbols]

[0203] 1, 101, 201, 301 Pendulum device 2, 102, 202 Pendulum member 21 Pendulum body 22, 22a, 22b, 122, 222 Pendulum side magnetic member 3 Pendulum support member 31 Support mechanism 32 Axis 4a, 4b, 104, 204 Fixed magnetic members 5a, 5b Magnetic member support portion 6 Support body 10 Vibration control device 20 Building 220 Vibration Control Objects

Claims

1. a pendulum member that performs pendulum motion around a fulcrum and is at least partially constituted by a first magnetic member; a fixed member that applies a repulsive or attractive force to the pendulum member by a magnetic force and is at least partially constituted by a second magnetic member; A pendulum device comprising:

2. 2. The pendulum device according to claim 1, wherein the pendulum member is rotatably suspended from the fulcrum.

3. 2. The pendulum device according to claim 1, wherein the pendulum motion is any one of a simple pendulum motion, a spherical pendulum motion, and a conical pendulum motion.

4. 2. The pendulum device according to claim 1, wherein the pendulum member has rigidity, is capable of simple pendulum motion in a vertical plane about the fulcrum, and is maintained in a horizontal state by a repulsive or attractive force between the first magnetic member and the second magnetic member when in a stationary state.

5. 2. The pendulum device according to claim 1, wherein the pendulum member has rigidity, is capable of simple pendulum motion within a horizontal plane centered on the fulcrum, and is maintained in a vertical state with respect to a vertical plane that includes the fulcrum and is perpendicular to the horizontal plane by a repulsive force or an attractive force between the first magnetic member and the second magnetic member when the pendulum member is in a stationary state.

6. the pendulum motion is a simple pendulum motion, the second magnetic members are a pair, and the pair of second magnetic members are arranged facing each other with the pendulum member therebetween in a motion direction of the simple pendulum motion, 6. The pendulum device according to claim 1, wherein the first magnetic members are arranged for each of the second magnetic members so as to face each of the second magnetic members.

7. the second magnetic member is disposed so as to surround the pendulum member, 4. The pendulum device according to claim 1, wherein the first magnetic member and the second magnetic member are arranged such that the magnetic poles on the sides facing each other are the same pole or different poles.

8. 6. The pendulum device according to claim 1, wherein the first magnetic member and the second magnetic member are each formed of a permanent magnet or an electromagnet.

9. 6. The pendulum device according to claim 1, wherein the external shapes of the first magnetic member and the second magnetic member are either cylindrical, prismatic, spherical, arc-shaped, ring-shaped, hollow cylindrical, curved, or flat.

10. The second magnetic member has a flat or curved outer shape, 6. The pendulum device according to claim 1, wherein the first magnetic member and the second magnetic member are arranged such that the magnetic poles on the sides facing each other are the same pole or different poles.

11. 6. The pendulum device according to claim 1, wherein at least one of the magnetic flux density of at least one of the first magnetic member and the second magnetic member, the relative position of the first magnetic member and the second magnetic member, and the mass of the pendulum member is adjustable.

12. 6. The pendulum device according to claim 1, wherein the fulcrum is provided directly on an object to be damped or on a structural part fixed to the object to be damped.

13. A vibration damping device that damps the vibration of an object to be damped by using a pendulum device that performs pendulum motion, A vibration damping device, comprising the pendulum device according to any one of claims 1 to 5 as the pendulum device.

14. A method for designing a vibration damping device that damps vibration of an object to be damped by using a pendulum member that performs pendulum motion, comprising the steps of: A first magnetic member is disposed on at least a portion of the pendulum member; A second magnetic member is disposed at a position where a repulsive force or an attractive force due to a magnetic force is applied to the first magnetic member; A method for designing a vibration damping device, comprising adjusting at least one of the magnetic flux densities of the first magnetic member and the second magnetic member, the relative position of the first magnetic member and the second magnetic member, and the mass of the pendulum member so that the sum of the restoring force due to gravity of the pendulum member and the restoring force due to the magnetic force between the first magnetic member and the second magnetic member has desired restoring force characteristics.

15. A pendulum member that performs a pendulum motion around a fulcrum and at least a portion of the pendulum member is composed of the first magnetic member; and the first magnetic member is disposed on at least a portion of the pendulum member; A second magnetic member is disposed at a position where a repulsive force or an attractive force due to a magnetic force is applied to the first magnetic member; a pendulum device comprising: a pendulum member having a magnetic flux density of the first magnetic member and the second magnetic member; a magnetic flux density of the first magnetic member and the second magnetic member; a magnetic flux density of the second magnetic member; a magnetic flux density of the first magnetic member and the second magnetic member; and a magnetic flux density of the second magnetic member;

16. 16. The pendulum device according to claim 15, wherein the restoring force characteristic is either a linear characteristic, a soft spring characteristic or a hard spring characteristic.

17. a first pendulum member that performs pendulum motion about a fulcrum and is at least partially constituted by a first magnetic member; a first fixed member that applies a repulsive force due to a magnetic force to the first pendulum member and is at least partially constituted by a second magnetic member; a second pendulum member that performs pendulum motion about the fulcrum and is at least partially constituted by a third magnetic member; a second fixed member that applies a magnetic attraction force to the second pendulum member, the second fixed member being at least partially constituted by a fourth magnetic member.

18. At least one of the first magnetic member, the second magnetic member, the third magnetic member, and the fourth magnetic member is an electromagnet, 18. The pendulum device according to claim 17, wherein at least one of the hard spring characteristics of the first pendulum member due to the repulsive force and the soft spring characteristics of the second pendulum member due to the attractive force can be changed by at least one of changing the magnitude of the magnetic force of the electromagnet and deactivating the electromagnet.

19. 19. The pendulum device according to claim 18, wherein the first magnetic member and the second magnetic member are each formed of a permanent magnet or an electromagnet, and the third magnetic member and the fourth magnetic member are each formed of a permanent magnet or an electromagnet.

20. 20. The pendulum device according to claim 17, further comprising a generator that converts vibration of the first pendulum member or the second pendulum member into electrical energy.

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