Vibration Damping Device

Abstract

A vibration damping device that utilizes magnetic force, in which restrictions on the amount of movement of a member that applies magnetic force are suppressed. [Solution] The vibration damping device comprises an inner member and an outer member configured to be able to move back and forth relative to one another along a first direction, wherein the inner member is positioned inside the outer member in a second direction perpendicular to the first direction and comprises an end member configured opposite the magnetic pole of the outer member in the second direction and made of a magnetic material, and the outer member comprises a magnetic device configured to attract the end member in an equilibrium state, and movement of the end member and the magnetic device in the second direction is restricted so as not to come into contact.

Description

[Technical field]

[0001] The present invention relates to a vibration damping device that utilizes magnetic force. [Background technology]

[0002] Conventionally, the magnetic flux collector includes a base, an upper annular permanent magnet, a lower annular permanent magnet, a connecting rod, and a central permanent magnet, a metal conductor sleeve is connected to the upper surface of the base, the metal conductor sleeve is a hollow metal cylinder, the base seals the lower end surface of the metal conductor sleeve, the upper annular permanent magnet and the lower annular permanent magnet have the same shape and are both hollow rings, the upper annular permanent magnet and the lower annular permanent magnet are fitted into an upper annular bush and a lower annular bush, respectively, the upper annular bush and the lower annular bush are connected to the upper end and the lower end of the inner wall of the metal conductor sleeve, respectively, the upper annular permanent magnet, the lower annular permanent magnet, and the metal conductor sleeve are concentric in the axial direction, and the upper annular permanent magnet is fitted into an upper annular bush and a lower annular bush, respectively ..., the lower annular permanent magnet, and the metal conductor sleeve are concentric in the axial direction, A one-degree-of-freedom magnetic vibration isolation device is known, characterized in that "the polarities of the magnetic poles on the opposing surfaces of the annular permanent magnet and the lower annular permanent magnet are opposite, the axis of the connecting rod is coaxial with the central axis of the metal conductor sleeve, the central permanent magnet is a hollow ring which is concentrically covered with the connecting rod and fixed thereto, the upper end of the connecting rod passes through the central hole of the upper annular permanent magnet, the central permanent magnet is located between the upper annular permanent magnet and the lower annular permanent magnet and can move axially together with the connecting rod between the upper annular permanent magnet and the lower annular permanent magnet, the polarities of the magnetic poles on the opposing surfaces of the central permanent magnet and the upper annular permanent magnet are opposite, and the polarities of the magnetic poles on the opposing surfaces of the central permanent magnet and the lower annular permanent magnet are opposite" (see, for example, Reference 1).

[0003] The one-degree-of-freedom magnetic vibration isolation device disclosed in the cited document 1 "can generate magnetostatic and dynamic forces without requiring energy supply and with high reliability. The magnetostatic force is realized by mutual attraction between opposite poles of a permanent magnet, and the dynamic force is realized by an eddy current damper generated by the relative motion of a metal conductor sleeve and a permanent magnet. The magnitude of the magnetostatic force is related only to the displacement, and the magnetic force exists even when the device of the present invention is stationary, so it can be considered as a kind of rigid force, while the eddy current damper is related only to the relative motion speed and exists only when motion occurs in the magnetic mechanism, so it can be considered as a kind of viscous damping force." In addition, this one-degree-of-freedom magnetic vibration isolation device "can be arranged in parallel with a passive vibration isolation structure such as a rigid coil spring or an air spring, thereby reducing the increase in amplitude value at the natural frequency without affecting the high-frequency damping performance of the passive vibration isolation system, and effectively improving the passive vibration isolation performance of the original system." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6317822 Summary of the Invention [Problem to be solved by the invention]

[0005] The one-degree-of-freedom magnetic vibration isolation device disclosed in Patent Document 1 "opposes the polarity of the magnetic poles on the opposing surfaces of the upper annular permanent magnet and the lower annular permanent magnet," and "the central permanent magnet is located between the upper annular permanent magnet and the lower annular permanent magnet, and moves axially between the upper annular permanent magnet and the lower annular permanent magnet together with the connecting rod." Therefore, when the central permanent magnet moves in either the up or down direction from the equilibrium state, the upper annular permanent magnet or the lower annular permanent magnet is present on its extension line, so that the amount of movement of the central permanent magnet is limited.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a vibration damping device that uses magnetic force and minimizes restrictions on the amount of movement of the member that applies the magnetic force. [Means for solving the problem]

[0007] The vibration damping device of the present invention is a vibration damping device comprising an inner member and an outer member configured to be able to move back and forth relative to one another along a first direction, wherein the inner member is arranged inside the outer member in a second direction perpendicular to the first direction and comprises an end member made of a magnetic material arranged opposite a magnetic pole of the outer member in the second direction, the outer member comprises a magnetic device configured to attract the end member in an equilibrium state, and movement of the end member and the magnetic device in the second direction is restricted so as not to come into contact with each other. Effect of the Invention

[0008] According to the above invention, a magnetic force in a direction in which the inner member and the outer member are attracted to each other is generated between the inner member and the outer member, and since the movement paths of the inner member and the outer member do not intersect, the movement of each member is not restricted. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a main configuration of a vibration damping device 100 according to a first embodiment. [Diagram 2] 2 is an enlarged view of the first end 13 and the magnetic pole 21a of the magnetic device 21 of FIG. [Diagram 3] 2 is a schematic diagram showing a state in which the inner member 10 of the vibration damping device 100 shown in FIG. 1 has been moved in the z direction. [Figure 4] 5 is a diagram showing the relationship between the moving distance of the inner member 10 of the vibration damping device 100 according to the first embodiment and the generated magnetic force. FIG. [Diagram 5] 1 is a schematic diagram of a main configuration of a vibration damping device 100A which is a modified example of the vibration damping device 100 according to the first embodiment. [Figure 6]6 is a diagram showing the relationship between the moving distance of the inner member 10 of the vibration damping device 100A according to the modified example shown in FIG. 5 and the generated magnetic force. FIG. [Figure 7] 1 is an example of a schematic diagram of a vibration damping device 100 and 100A according to embodiment 1 in a plan view (as viewed from the z direction). [Figure 8] 10 is another example of a schematic diagram showing the vibration damping devices 100 and 100A according to the first embodiment in a plan view (as viewed from the z direction). FIG. [Figure 9] 1 is a schematic diagram of a main configuration of a vibration damping device 100B which is a modified example of the vibration damping device 100 according to the first embodiment. [Figure 10] 1 is a schematic diagram of a main configuration of a vibration damping device 100C which is a modified example of the vibration damping device 100 according to the first embodiment. [Figure 11] 10 is a schematic diagram of a main configuration of a vibration damping device 200 according to a second embodiment. FIG. [Figure 12] 2 is a diagram showing the relationship between the movement distance of the inner member 10 and the generated load in the vibration damping device 100 shown in FIG. 1, and the relationship between the expansion and contraction amount of the elastic member 30 and the generated load. FIG. [Figure 13] 10 is a diagram showing the relationship between the moving distance of the inner member 10 of the vibration damping device 200 according to the second embodiment and the generated magnetic force. FIG. [Figure 14] 5. FIG. 12 is a diagram showing the relationship between the moving distance of the inner member 10 and the generated magnetic force when the vibration damping device 100 in the vibration damping device 200 shown in FIG. 11 is replaced with the vibration damping device 100A shown in FIG. [Figure 15] FIG. 11 is a schematic diagram of a main configuration of a vibration damping device 300 according to a third embodiment. [Figure 16] 16 is a schematic diagram of a state in which the inner member 10 has been moved in the z2 direction from the vibration damping device 300 in the state shown in FIG. 15. FIG. [Figure 17] 1 is a schematic diagram of the main configuration of a vibration damping device 100D which is a modified example in which the second end portion 12 is removed from the vibration damping device 100 according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The preferred embodiments of the vibration damping device of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below are preferred specific examples of the present invention, and therefore various technically preferable limitations are attached, but the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited.

[0011] Embodiment 1 <Vibration damping device 100> FIG. 1 is a schematic diagram of a main configuration of a vibration damping device 100 according to a first embodiment. The vibration damping device 100 shown in FIG. 1 includes an inner member 10 movable in the z direction and a fixed outer member 20. For example, the inner member 10 of the vibration damping device 100 is connected to another structure, and acts to suppress the displacement of the structure in the z direction by magnetic force. The vibration damping device 100 is used for the purpose of damping vibrations in, for example, automobile dampers, seismic isolation devices for buildings, or vibration control devices for machines. Note that, although an example in which the inner member 10 moves in the z direction is described in the first embodiment, the vibration damping device 100 may have a structure in which the inner member 10 and the outer member 20 can move relatively in the z direction.

[0012] In the vibration damping device 100, for example, the outer member 20 is formed in a cylindrical shape. The outer member 20 surrounds the inner member 10 from a direction perpendicular to the z direction. The outer member 20 includes a magnetic device 21. In the magnetic device 21, a pair of magnetic poles 21a and 21b are arranged along the z direction in a cross section parallel to the z direction. In FIG. 1, the magnetic device 21A and the magnetic device 21B are arranged so that the S pole is located at the end in the z1 direction and the N pole is located at the end in the z2 direction. The magnetic device 21A and the magnetic device 21B may be an integrated magnetic device or may be separate magnetic devices. The z direction may be referred to as the first direction, and the direction perpendicular to the z direction may be referred to as the second direction.

[0013] The inner member 10 is disposed inside the outer member 20 in a direction (xy direction) perpendicular to the z direction. The inner member 10 has a first end 13 and a second end 12 disposed apart in the z direction. The first end 13 and the second end 12 are each made of a magnetic material. In FIG. 1, the first end 13 and the second end 12 are each made of a magnet, but may be made of a soft magnetic material such as iron or nickel. In other words, the first end 13 and the second end 12 may have no or almost no magnetic force by themselves, but may be attracted to the magnetic device 21.

[0014] The first end 13 and the second end 12 are connected by a connecting member 11 in the z direction. The connecting member 11 is a member for keeping the distance between the first end 13 and the second end 12 constant. The connecting member 11 may be a non-magnetic material such as a resin material, or may be a metal containing a magnetic material. The inner member 10 may include structures that support the first end 13 and the second end 12 at the ends in the z direction, and the structures may be connected to each other in the z direction by the connecting member 11. The structures that support the first end 13 and the second end 12 may be members formed integrally with the connecting member 11, or separate members may be connected by means of members such as bolts or welding. The first end 13 and the second end 12 may be collectively referred to as an end member. In other words, the first end 13 and the second end 12 constitute an end member.

[0015] The first end 13 and the second end 12 are configured to be attracted to the magnetic pole 21a or 21b of the magnetic device 21 in the balanced state shown in Fig. 1. The tip 13a of the first end 13 is configured to be attracted to the magnetic pole 21a of the magnetic device 21, and is the N pole in the example shown in Fig. 1. The tip 12a of the second end 12 is configured to be attracted to the magnetic pole 21b of the magnetic device 21, and is the S pole in the example shown in Fig. 1.

[0016] In FIG. 1, the structure supporting each of the inner member 10 and the outer member 20 is not shown, but the vibration damping device 100 may be provided with a structure supporting each of the inner member 10 and the outer member 20. Alternatively, since the inner member 10 is configured to be attracted to the outer member 20, a spacer or bearing may be provided to maintain a predetermined distance between the inner member 10 and the outer member 20 so that the tip 13a of the first end 13 and the tip 12a of the second end 12 do not come into contact with the magnetic poles 21a and 21b. In addition, the distance between the inner member 10 and the outer member 20 in a direction perpendicular to the z direction may be configured to be dynamically controllable. The magnetic force of attraction can be controlled by dynamically controlling the distance between the end members (the first end 13 and the second end 12) and the magnetic device 21 in a direction perpendicular to the z direction. This allows the damping force of the vibration damping device 100 to be controlled.

[0017] Fig. 2 is an enlarged view of the first end 13 and the magnetic pole 21a of the magnetic device 21 in Fig. 1. Fig. 2(a) illustrates a schematic diagram of the magnetic force generated at the first end 13. Fig. 2(b) illustrates a schematic diagram of the distribution of magnetic field lines of the magnetic device 21. The operating principle of the vibration damping device 100 will be explained with reference to Figs. 1 and 2.

[0018] The tip 13a of the first end 13 of the inner member 10 is positioned so as to face the magnetic pole 21a of the magnetic device 21 in the x direction. The tip 13a of the first end 13 is an N pole, and receives a magnetic force in an attractive direction along the magnetic field lines generated from the magnetic pole 21a of the magnetic device 21 shown in FIG. 2(b). Therefore, as shown in FIG. 2(a), the end on the z2 side of the end face of the tip 13a generates a magnetic force fa, and the end on the z1 side of the end face of the tip 13a generates a magnetic force fb. The magnetic forces fa and fb are resolved into x-direction component forces xa and xb, and z-direction component forces za and zb. FIG. 2(a) shows the balanced state (initial position) of the vibration damping device 100, and the z-direction component forces za and zb are balanced. Further, the x-direction component forces xa and xb balance with the magnetic force generated between the tip 13a of the first end 13 located on the x2 side shown in FIG. 1 and the magnetic pole 21a of the magnetic device 21A.

[0019] Since the tip 13a of the first end 13 and the tip 12a of the second end 12 of the inner member 10 are subjected to component forces as shown in FIG. 2(a), the magnetic forces are balanced in the z direction and in a direction perpendicular to the z direction (the x direction in FIG. 2), and the inner member 10 and the outer member 20 are stationary. The state in which the vibration damping device 100 is stationary in this manner is called an equilibrium state. If the magnetic forces generated between the inner member 10 and the outer member 20 are ideally balanced, the inner member 10 and the outer member 20 can maintain a state of equilibrium even without a support structure, but the vibration damping device 100 has a structure that restricts at least the inner member 10 and the outer member 20 from moving in a direction perpendicular to the z direction because it is connected to an external structure and receives an external force. The inner member 10 and the outer member 20 may be supported by a support member such as a bearing, and the movement in a direction perpendicular to the z direction may be restricted, or one of them may be fixed. In any case, the inner member 10 and the outer member 20 are configured to be able to move relatively to each other at least in the z direction.

[0020] 2(a), the center of the z-direction width of the tip 13a of the first end 13 of the inner member 10 and the tip surface of the magnetic device 21B of the outer member 20 are aligned in the z-direction, which is an equilibrium state. However, for example, when the inner member 10 is subjected to an external force such as gravity, the equilibrium state shifts in the direction of gravity. At this time, the load received by the inner member 10 in the direction of gravity and the magnetic forces generated at the first end 13 and the second end 12 are balanced in the z-direction, and this position is the equilibrium state.

[0021] FIG. 3 is a schematic diagram showing a state where the inner member 10 of the vibration damping device 100 shown in FIG. 1 has moved in the z direction. FIG. 3(a) shows a state where the inner member 10 has moved in the z1 direction, and FIG. 3(b) shows a state where the inner member has moved in the z2 direction. The inner member 10 is configured such that the first end 13 and the second end 12 are attracted to the magnetic poles 21a and 21b of the magnetic device 21. Therefore, the inner member 10 receives a magnetic force in the opposite direction to the direction of movement, regardless of whether the inner member 10 moves in the z1 direction or the z2 direction. In other words, when the inner member 10 moves from the equilibrium state in the z1 direction, it receives a magnetic force in the z2 direction, and when the inner member 10 moves from the equilibrium state in the z2 direction, it receives a magnetic force in the z1 direction. In this way, in the vibration damping device 100, a magnetic force is generated in the opposite direction to the direction in which the inner member 10 moved, so that, for example, when a displacement occurs in a structure connected to the inner member 10, a magnetic force is generated in the opposite direction to the direction of movement, and a force that tries to return the inner member 10 to the equilibrium state is generated. The vibration damping device 100 thus damps vibrations induced in structures connected to the inner member 10 .

[0022] FIG. 4 is a diagram showing the relationship between the moving distance of the inner member 10 of the vibration damping device 100 according to the first embodiment and the generated magnetic force. The moving distance indicates the relative distance fluctuation in the z direction between the inner member 10 and the outer member 20, and a large moving distance means that the magnetic poles 21a and 21b of the magnetic devices 21A and 21B are apart from the tip 13a of the first end 13 and the tip 12a of the second end 12 in the z direction. The balanced state of the vibration damping device 100 is shown as a moving distance of 0. The load in FIG. 4 shows an absolute value. That is, in FIG. 1 and FIG. 3, when the inner member 10 moves in the z1 direction, the load shown in FIG. 4 acts in the z2 direction according to the moving distance, and when the inner member 10 moves in the z2 direction, the load shown in FIG. 4 acts in the z1 direction according to the moving distance.

[0023] Magnetic force is inversely proportional to the square of the distance between objects over which it acts. Thus, as shown in Figure 4, if the inner member 10 moves in the z direction relative to the outer member 20, the greater the distance moved, the weaker the force attempting to return the inner member 10 to equilibrium.

[0024] FIG. 5 is a schematic diagram of the main configuration of a vibration damping device 100A which is a modified example of the vibration damping device 100 according to the first embodiment. As shown in FIG. 5, the tip 13a of the first end 13 and the tip 12a of the second end 12 of the inner member 10 of the vibration damping device 100A are configured so that their widths become narrower toward the outside in a direction perpendicular to the z direction. As shown in FIG. 5(a), the tip 13a of the first end 13 and the tip 12a of the second end 12 may be formed in a shape with pointed edge portions 13c, 12c, or as shown in FIG. 5(b), flat surfaces may remain on the edge portions 13c, 12c. In other words, the tip 13a of the first end 13 and the tip 12a of the second end 12 of the inner member 10 may have a trapezoidal shape provided with inclined portions 13d, 12d such that the width in the z direction becomes smaller toward the tip. Furthermore, as shown in FIG. 5(c), the tip 13a and the tip 12a may have a structure in which a step is formed. In this case, a plurality of end faces 13e located on the inner side of edge portion 13c may be provided. In other words, tip 13a and tip 12a may be formed in a stepped shape.

[0025] Fig. 6 is a diagram showing the relationship between the moving distance of the inner member 10 of the vibration damping device 100A according to the modified example shown in Fig. 5 and the generated magnetic force. In the case of the vibration damping device 100A, since the width of the tip 13a of the first end 13 of the inner member 10 is narrow, the influence of the magnetic force of the edge portion 13c of the tip 13a is large and the influence of the magnetic force of the inclined portion 13d is small. Therefore, when moved in the z direction from the balanced state shown in Fig. 5, the influence of the magnetic force generated in the edge portion 13c becomes dominant.

[0026] Therefore, for example, assuming that edge portion 13c of tip 13a of first end portion 13 moves slightly in the z1 direction, a force that returns edge portion 13c to an equilibrium state is generated by the magnetic force generated in the z2 direction. In contrast, the effect of the magnetic force generated in inclined portion 13d is smaller than that of the magnetic force generated in edge portion 13c, and the magnetic force that cancels the magnetic force that returns edge portion 13c to the z2 direction is small. Therefore, the force that returns tip 13a of first end portion 13 to an equilibrium state is larger than when tip 13a has a flat surface along the z direction as shown in FIG. 2.

[0027] 2, when tip 13a has a plane along the z direction, as tip 13a moves in the z1 direction, magnetic force fa increases and magnetic force fb decreases. In this case, the z-direction component of magnetic force fa (i.e., the force facing the z1 direction) is greater than the z-direction component of magnetic force fb (i.e., the force facing the z2 direction), and the force pulling tip 13a back in the z2 direction is reduced because the z-direction component of magnetic force fa and the z-direction component of magnetic force fb cancel each other out.

[0028] Therefore, in the case of the vibration damping device 100A of the modified example shown in FIG. 5, as indicated by the solid line in the graph of FIG. 6, the reduction in load due to movement of the inner member 10 in the z direction becomes gradual.

[0029] Furthermore, when the width of the tip 13a of the first end 13 and the tip 12a of the second end 12 shown in Fig. 5 is configured to be narrower, it is preferable to configure the edge portions 13c and 12c to be located closer to the magnetic pole of the magnetic device 21 than the tips 13a and 12a which are flat surfaces as shown in Fig. 1. By configuring in this way, the vibration damping device 100A shown in Fig. 5 suppresses a decrease in the magnetic force acting on the inner member 10 with respect to the vibration damping device 100, while gradual reduction in the load due to movement of the inner member 10 in the z direction as shown in Fig. 6.

[0030] FIG. 7 is an example of a schematic diagram of the vibration damping device 100 and 100A according to the first embodiment in a plan view (as viewed from the z direction). FIG. 7(a) is a diagram showing a case where the outer member 20 is configured to surround the inner member 10 from the x direction and the y direction. As shown in FIG. 7(a), the vibration damping device 100 and 100A may be configured such that the outer member 20 is formed in a rectangular tubular shape and the inner member 10 is disposed inside the outer member 20. The structure shown in FIG. 1 and FIG. 5 shows the cross-sectional structure of the AA portion of FIG. 7(a), which shows the cross-sectional structure parallel to the z direction and the x direction. In the vibration damping device 100 and 100A shown in FIG. 7(a), the cross-sectional structure parallel to the z direction and the y direction is also the same as the structure shown in FIG. 1 and FIG. 5.

[0031] 7(b) is a schematic diagram of another example of the vibration damping devices 100 and 100A in plan view (as viewed from the z direction). The outer member 20 does not necessarily have to surround the entire periphery of the inner member 10, and may have a structure in which magnetic devices 21 are disposed on both ends in the x direction.

[0032] Furthermore, the outer member 20 may be circular in plan view or may have another shape, as long as the magnetic poles 21a and 21b of the magnetic device 21 are disposed to face the tip 13a and the second end 13b of the first end 13 in a direction perpendicular to the z direction.

[0033] 8 is another example of a schematic diagram of the vibration damping devices 100 and 100A according to the first embodiment in plan view (as viewed from the z direction). The inner member 10 may include a magnetic body formed in a triangular shape in plan view. In addition, the magnetic body is not limited to a triangular shape in plan view, and may have other shapes such as a rectangular shape.

[0034] 7(a) and (b), the magnetic poles 21a of the magnetic devices 21 of the outer member 20 all have the same polarity when viewed in plan, but the orientation of the magnetic devices 21 is not limited to this. As shown in Fig. 8, the four magnetic devices 21 arranged on the four sides of the rectangular outer member 20 are arranged so that the N poles are visible on the two opposing left and right sides and the S poles are visible on the two opposing top and bottom sides. The magnetic poles of the magnets of the inner member 10 are arranged to match the magnetic devices 21 of the outer member 20.

[0035] 9 is a schematic diagram of the main configuration of a vibration damping device 100B which is a modified example of the vibration damping device 100 according to the first embodiment. In the vibration damping device 100B, the tip 13a of the first end 13 and the tip 12a of the second end 12 of the inner member 10 are configured with a pair of magnetic poles of a magnet. The magnetic device 21 provided in the outer member 20 has magnetic poles arranged in accordance with the magnetic poles of the tip 13a of the first end 13 and the tip 12a of the second end 12. With this configuration, the width of the first end 13 and the second end 12 of the inner member 10 in the x direction is reduced, and the width of the vibration damping device 100B can be configured compactly.

[0036] Fig. 10 is a schematic diagram of the main configuration of a vibration damping device 100C which is a modified example of the vibration damping device 100 according to the first embodiment. The vibration damping device 100C is obtained by eliminating the first end 13 and the second end 12 arranged on the x1 side of the inner member 10 shown in Fig. 1. The inner member 10 is configured to limit movement in the x direction and guide movement in the z direction, so that the first end 13 and the second end 12 arranged symmetrically in the x direction can be eliminated. Even with this structure, the inner member 10 functions in the same way as the vibration damping device 100 shown in Fig. 1, since a force acts on the inner member 10 to return it to an equilibrium state when it moves in the z direction.

[0037] The vibration damping devices 100, 100A, 100B, and 100C described above can provide a structure that includes the inner member 10 and the outer member 20 that can relatively reciprocate in the z direction, and that attempts to return the inner member 10 and the outer member 20 to an equilibrium state by the action of magnetic force. In the vibration damping devices 100, 100A, 100B, and 100C, the outer member 20 is disposed in a position that does not interfere with the moving direction of the inner member 10, so that when the inner member 10 moves in either the z1 direction or the z2 direction relative to the outer member 20, a load that attempts to return to an equilibrium state by the action of magnetic force acts on the inner member 10, making it possible to damp the vibrating displacement.

[0038] Moreover, the one-degree-of-freedom magnetic vibration isolator disclosed in Patent Document 1 is configured so that the magnetic force becomes stronger as the amount of displacement in either the up or down direction increases. However, this one-degree-of-freedom magnetic vibration isolator "opposes the polarity of the magnetic poles on the opposing surfaces of the upper and lower annular permanent magnets" and "the central permanent magnet is located between the upper and lower annular permanent magnets and moves in the axial direction between the upper and lower annular permanent magnets together with the connecting rod." Therefore, when the central permanent magnet moves in either the up or down direction from the equilibrium state, the magnetic force in the direction of movement becomes large, and an external force larger than the magnetic force is required to pull it back to the equilibrium state. Also, since the upper or lower annular permanent magnet is present on the extension line of the path along which the central permanent magnet moves, the amount of movement is limited. On the other hand, in the vibration damping devices 100, 100A, 100B, and 100C according to the first embodiment, the outer member 20 is not present on the path along which the inner member 10 moves, so the inner member 10 and the outer member 20 do not restrict each other's movement.

[0039] Embodiment 2 A vibration damping device 200 according to embodiment 2 will be described. The vibration damping device 200 according to embodiment 2 is a combination of the vibration damping device 100 according to embodiment 1 and an elastic member 30. Note that components having the same functions and actions as those in embodiment 1 are given the same reference numerals and descriptions thereof will be omitted.

[0040] 11 is a schematic diagram of the main components of a vibration damping device 200 according to the second embodiment. The vibration damping device 200 is a combination of the vibration damping device 100 and an elastic member 30. The elastic member 30 is formed, for example, of a helical spring, and is connected to the inner member 10 so that, when the inner member 10 moves in the z direction, a load is applied in the direction opposite to the direction of movement. The elastic member 30 is also fixed to the support body 31, and is configured so as to be able to expand and contract in accordance with the movement of the inner member 10.

[0041] Fig. 12 is a diagram showing the relationship between the movement distance of the inner member 10 and the generated load in the vibration damping device 100 shown in Fig. 1, and the relationship between the expansion and contraction amount of the elastic member 30 and the generated load. As shown in Fig. 12(a), in the vibration damping device 100 shown in Fig. 1, only magnetic force acts on the inner member 10, so that as the movement distance increases, the load decreases inversely proportional to the square of the distance. As shown in Fig. 12(b), when the elastic member 30 shown in Fig. 11 expands and contracts in the z direction, a load proportional to the expansion and contraction amount is generated in the opposite direction to the expansion and contraction direction.

[0042] Fig. 13 is a diagram showing the relationship between the movement distance of the inner member 10 of the vibration damping device 200 according to the second embodiment and the generated magnetic force. In the vibration damping device 200, the magnetic force and the load due to the expansion and contraction of the elastic member 30 act on the inner member 10 in response to the displacement of the inner member 10, so that the reduction in the load applied to the inner member 10 is suppressed compared to the action of only the magnetic force shown in Fig. 12(a). Therefore, when the inner member 10 is displaced in the z direction, the force that returns the inner member 10 to the equilibrium state decreases while the amount of displacement is small, but as the amount of displacement increases, the force that returns the inner member 10 to the equilibrium state increases due to the action of the elastic member 30.

[0043] In other words, the vibration damping device 200 according to the second embodiment experiences less change in the force that returns the device to the equilibrium state than the vibration damping device 100 according to the first embodiment.

[0044] Fig. 14 is a diagram showing the relationship between the movement distance of the inner member 10 and the generated magnetic force when the vibration damping device 100 in the vibration damping device 200 shown in Fig. 11 is replaced with the vibration damping device 100A shown in Fig. 5. The two-dot chain line shown in Fig. 14 shows the relationship between the displacement and load of the inner member 10 of the vibration damping device 200 shown in Fig. 11, and the solid line shown in Fig. 14 shows the relationship between the displacement and load of the inner member 10 when the inner member 10 shown in Fig. 11 is replaced with that of the vibration damping device 100A shown in Fig. 5. Since the vibration damping device 100A shown in Fig. 5 has a gradual change in load relative to the displacement of the inner member 10 as shown in Fig. 6, when combined with the elastic member 30, the change in the force pulling back to the equilibrium state becomes smaller and the change in load becomes closer to flat.

[0045] The elastic member 30 is not limited to a helical spring, and may be a leaf spring, rubber, or the like, as long as it generates elastic force by deformation. In the second embodiment, the elastic member 30 is connected to the lower side of the inner member 10, but the arrangement of the elastic member 30 may be changed as appropriate. For example, the elastic members 30 may be arranged at intervals in the moving direction of the inner member 10, and a load from the elastic member 30 may act on the inner member 10 when the amount of movement of the inner member 10 reaches or exceeds a predetermined amount. In addition, when the outer member 20 of the vibration damping device 200 is configured to move, the load from the elastic member 30 may be applied to the outer member 20.

[0046] 11 may be disposed between the first end 13 and the second end 12 of the inner member 10. For example, the elastic member 30 may be disposed between the first end 13 and the second end 12 of the inner member 10 and fixed to the outer member 20. In this way, when the inner member 10 moves in the z direction relative to the outer member 20, the inner member 10 comes into contact with the elastic member 30, and the elastic member 30 can function in the same manner as the elastic member 30 of the vibration damping device 200 shown in FIG.

[0047] Embodiment 3 A vibration damping device 300 according to embodiment 3 will be described. The vibration damping device 300 according to embodiment 3 uses electromagnets as the magnetic devices 21A and 21B of the outer member 20 of the vibration damping device 100 according to embodiment 1. Note that components having the same functions and actions as those in embodiments 1 and 2 are given the same reference numerals and descriptions thereof will be omitted.

[0048] Fig. 15 is a schematic diagram of the main configuration of a vibration damping device 300 according to the third embodiment. In the vibration damping device 300 according to the third embodiment, the magnetic device 21 included in the outer member 20 of the vibration damping device 100 according to the first embodiment is replaced with an electromagnet. The magnetic device 321 constituted by an electromagnet can change the positions of the magnetic poles 21a and 21b by partially passing a current through it. In Fig. 15, the part of the magnetic device 321 indicated by the solid line is through which a current flows, and the part indicated by the dashed line is through which a current does not flow. The magnetic device 321 shown in Fig. 15 is energized so that the magnetic poles are located at positions corresponding to the tip 13a of the first end 13 and the tip 12a of the second end 12.

[0049] Fig. 16 is a schematic diagram of a state in which the inner member 10 has moved in the z2 direction from the vibration damping device 300 in the state shown in Fig. 15. In Fig. 16, the magnetic device 321 provided in the outer member 20 moves the current-carrying range in the z2 direction in accordance with the movement of the inner member 10. In this way, the magnetic poles 21a and 21b of the magnetic device 321 move in accordance with the movement of the inner member 10, so that the vibration damping device 300 can be controlled so that the same magnetic force is applied even if the inner member 10 moves. In the vibration damping device 100 according to the first embodiment, as shown in Fig. 4, when the vibration damping device 100 moves in the z direction, the magnetic force decreases as the amount of movement increases, but according to the vibration damping device 300 according to the third embodiment, the magnetic force acting on the inner member 10 can be maintained approximately constant even if the inner member 10 moves in the z direction.

[0050] The magnetic device 321 of the vibration damping device 100 is configured, for example, by connecting a plurality of coils 324 in the z direction, and is configured to be able to select the coil 324 to be energized in accordance with the movement of the inner member 10. For example, the magnetic device 321 is configured by arranging the plurality of coils 324 so that the central axis of the winding is along the z direction, and is configured to be able to control the current flowing through each of the plurality of coils 324. In other words, the magnetic device 321 is configured so that the magnetic poles can be moved in the z direction by controlling the current flowing through the plurality of coils 324. Note that the magnetic device 321 is not limited to being configured by arranging a plurality of coils 324 continuously along the z direction as shown in Figs. 15 and 16, and can be appropriately modified, for example, by arranging the plurality of coils at intervals.

[0051] 15 and 16, the outer member 20 includes the magnetic devices 321A and 321B, but these may be an integrated magnetic device 321.

[0052] Furthermore, the magnetic devices 321A and 321B may control the magnetic force that attracts the first end 13 and the second end 12 by controlling the current flowing through the coil 324. This makes it possible to control the damping force of the vibration damping device 300.

[0053] The configurations shown in the above embodiments are merely examples, and it is possible to omit or change part of the configurations without departing from the spirit of the invention.

[0054] FIG. 17 is a schematic diagram of the main configuration of a vibration damping device 100D, which is a modification in which the second end 12 is removed from the vibration damping device 100 according to the first embodiment. The vibration damping devices 100, 100A, 100B, 100C, 200, and 300 shown in the first to third embodiments function as vibration damping devices even if either the first end 13 or the second end 12 constituting the end member is omitted. In the modification of FIG. 17, the first end 13 is supported by a structure 14, and the structure 14 is guided by a ball bearing 15 as an example. Even in this case, the force shown in FIG. 2(a) acts on the first end 13, so that the magnetic force acts as a vibration damping device. In this case, the magnetic device 21 does not need to have a pair of magnetic poles arranged along the z direction, and at least one magnetic pole may be arranged to face the first end 13 in a direction perpendicular to the z direction.

[0055] 17 can also be applied to the vibration damping devices 100A, 100B, 100C, 200, and 300. The structures of the structure 14 and the ball bearing 15 can be modified as appropriate, and the ball bearing 15 can be replaced with a sliding bearing or other support structure.

[0056] Furthermore, the present invention described above using the vibration damping devices 100, 100A, 100B, 100C, 100D, 200, and 300 may also include combinations of the features shown in the following Supplementary Notes 1 to 10. Such combinations are described below.

[0057] [Appendix 1] A vibration damping device including an inner member and an outer member configured to be relatively reciprocally movable along a first direction, The inner member includes: The outer member is disposed on an inner side of the outer member in a second direction perpendicular to the first direction, an end member made of a magnetic material and disposed opposite the magnetic pole of the outer member in the second direction; The outer member includes: a magnetic device configured to attract the end member in an equilibrium state; The end member and the magnetic device are Movement in the second direction is restricted so as not to come into contact with the Vibration damping device. [Appendix 2] 2. A vibration damping device according to claim 1, The inner member includes: The end member is composed of a first end and a second end spaced apart from each other in a first direction; a connecting member connecting the first end and the second end in a first direction, The magnetic device comprises: A pair of magnetic poles are arranged along a first direction, Each of the pair of magnetic poles is In a balanced state, the first end and the second end are disposed opposite each other in a second direction, The first end and the second end are configured to be attracted to a magnetic pole of the magnetic device that faces in a second direction in an equilibrium state; Vibration damping device. [Appendix 3] 3. A vibration damping device according to claim 1 or 2, The magnetic device comprises: It consists of multiple magnetic devices. The plurality of magnetic devices At least a pair of magnetic devices are arranged at positions facing each other in the second direction across the inner member, Vibration damping device. [Appendix 4] A vibration damping device according to any one of claims 1 to 3, The end member is It is made up of permanent magnets. The magnetic poles of the magnetic device are The polarity is set to be opposite to that of the end member. Vibration damping device. [Appendix 5] A vibration damping device according to any one of claims 1 to 3, The end member is Made of soft magnetic material, Vibration damping device. [Appendix 6] A vibration damping device according to any one of claims 1 to 5, The end member is In a cross section including the central axis of the inner member, the tip in the second direction has a structure in which the width in the first direction narrows as it moves outward from the central axis. Vibration damping device. [Appendix 7] A vibration damping device according to any one of claims 1 to 6, The elastic member further includes an elastic member that applies a load in a direction opposite to the direction of relative movement between the inner member and the outer member in a first direction. Vibration damping device. [Appendix 8] 8. A vibration damping device according to claim 7, The elastic member is connected to at least one of the inner member and the outer member; Vibration damping device. [Appendix 9] A vibration damping device according to any one of claims 1 to 8, The magnetic device comprises: The pair of magnetic poles are electromagnets configured to be movable in a first direction. Vibration damping device. [Appendix 10] 10. A vibration damping device according to claim 9, The magnetic device comprises: The coils are arranged so that their central axes are aligned along a first direction, A magnetic pole is moved in a first direction by varying a part of the coils to which current is applied among the plurality of coils. Vibration damping device. [Explanation of symbols]

[0058] 10: Inner member 11: Connecting member 12:Second end 12a: Tip 12c: Edge section 13:First end 13a: Tip 13c: Edge section 13d: Inclined part 14 :Structure 15: Ball bearings 20:Outer member 21: Magnetic devices 21A: Magnetic devices 21B: Magnetic devices 21a: Magnetic pole 21b: Magnetic pole 30: Elastic member 31:Support 100: Vibration damping device 100A: Vibration damping device 100B: Vibration damping device 100C: Vibration damping device 200: Vibration damping device 300: Vibration damping device 321: Magnetic devices 321A: Magnetic Devices 321B :Magnetic devices 324: Coil

Claims

1. A vibration damping device including an inner member and an outer member configured to be relatively reciprocally movable along a first direction, The inner member includes: The outer member is disposed on an inner side of the outer member in a second direction perpendicular to the first direction, An end member made of a magnetic material, The end member is The first end and the second end are spaced apart in a first direction, The outer member includes: a magnetic device configured to attract the end member in an equilibrium state; The magnetic device comprises: A pair of magnetic poles are arranged along a first direction, Each of the pair of magnetic poles is In a balanced state, the first end and the second end are disposed opposite each other in a second direction; The first end and the second end are configured to be attracted to a magnetic pole of the magnetic device that faces in a second direction in an equilibrium state; The end member and the magnetic device are Movement in the second direction is restricted so as to avoid contact. Vibration damping device.

2. 2. The vibration damping device according to claim 1, The magnetic device comprises: It consists of multiple magnetic devices. The plurality of magnetic devices At least a pair of magnetic devices are disposed at positions facing each other in the second direction across the inner member. Vibration damping device.

3. 3. The vibration damping device according to claim 1 or 2, The end member is It is made up of permanent magnets. The magnetic poles of the magnetic device are The polarity is set to be opposite to that of the end member. Vibration damping device.

4. 3. The vibration damping device according to claim 1 or 2, The end member is Made of soft magnetic material, Vibration damping device.

5. 3. The vibration damping device according to claim 1 or 2, The end member is In a cross section including the central axis of the inner member, the tip in the second direction has a structure in which the width in the first direction narrows as it moves outward from the central axis. Vibration damping device.

6. 3. The vibration damping device according to claim 1 or 2, The elastic member further includes an elastic member that applies a load in a direction opposite to the direction of relative movement between the inner member and the outer member in a first direction. Vibration damping device.

7. 7. The vibration damping device according to claim 6, The elastic member is connected to at least one of the inner member and the outer member; Vibration damping device.

8. 2. The vibration damping device according to claim 1, The magnetic device comprises: The pair of magnetic poles are electromagnets configured to be movable in a first direction. Vibration damping device.

9. A vibration damping device including an inner member and an outer member configured to be relatively reciprocally movable along a first direction, The inner member includes: The outer member is disposed on an inner side of the outer member in a second direction perpendicular to the first direction, an end member made of a magnetic material and disposed opposite the magnetic pole of the outer member in the second direction; The outer member includes: a magnetic device configured to attract the end member in an equilibrium state; The end member and the magnetic device are Movement in the second direction is restricted so as not to come into contact with the The magnetic device comprises: The electromagnet is configured so that a pair of magnetic poles can be moved in a first direction by changing a current-carrying portion. Vibration damping device.

10. 10. A vibration damping device according to claim 8 or 9, The magnetic device comprises: The coils are arranged so that their central axes are aligned along a first direction, A magnetic pole is moved in a first direction by varying a part of the coils to which current is applied among the plurality of coils. Vibration damping device.

11. A vibration damping device including an inner member and an outer member configured to be relatively reciprocally movable along a first direction, The inner member includes: The outer member is disposed on an inner side of the outer member in a second direction perpendicular to the first direction, an end member made of a magnetic material and disposed opposite the magnetic pole of the outer member in the second direction; The outer member includes: a magnetic device configured to attract the end member in an equilibrium state; The end member and the magnetic device are Movement in the second direction is restricted so as not to come into contact with the The end member is In a cross section including the central axis of the inner member, the tip in the second direction has a structure in which the width in the first direction narrows as it moves outward from the central axis. Vibration damping device.

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