Anti-vibration device

Abstract

To provide a vibration isolator which can be sufficiently changed in stiffness by a simple constitution while using a magnetic fluid.SOLUTION: A vibration isolator 100 of the present invention includes an inside attachment member 1, a cylindrical outside attachment member 2, an elastic body 3 arranged between the inside attachment member 1 and the outside attachment member 2, and a liquid chamber 4 using the elastic body 3 as at least a part of a chamber wall. In the vibration isolator 100, a portion 23 protruding toward the liquid chamber 4 in a radial direction is formed at the outside attachment member 2, a magnetic fluid MF is sealed into the liquid chamber 4, and at least a part of the protrusion 23 of the outside attachment member 2 in a circumferential direction is constituted of at least a part of electromagnets 24 including a yoke 241 and an electromagnetic coil 242 which is wound around the yoke 241. The electromagnets 24 are arranged in a plurality of pieces in the circumferential direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an anti-vibration device. [Background technology]

[0002] Conventionally, known variable-rigidity vibration-damping devices that can change the rigidity and damping characteristics as desired include vibration-damping devices in which a magnetic fluid is sealed in a liquid chamber facing an elastic body. For example, Patent Document 1 discloses a vibration-damping device in which a partition wall separating the liquid chamber containing the magnetic fluid into a first liquid chamber and a second liquid chamber is provided with a circumferential passage that connects the two liquid chambers and a single electromagnet consisting of a yoke and a coil, and in which the viscosity of the magnetic fluid can be changed by passing an electric current through the coil, thereby changing the rigidity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-139547 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, a circumferential passage and one electromagnet consisting of a yoke and a coil are formed inside the partition wall that divides the liquid chamber into two, which makes the structure of the vibration-damping device complex. Furthermore, if the number of electromagnets (coils) is increased in order to achieve a more sufficient change in rigidity, the structure of the device becomes even more complex, which in turn leads to problems such as increased space and cost.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an anti-vibration device that uses a magnetic fluid and has a simple structure and can sufficiently change the rigidity. [Means for solving the problem]

[0006] The vibration isolation device of the present invention comprises: 1. A vibration-damping device comprising: an inner mounting member; a cylindrical outer mounting member; an elastic body disposed between the inner mounting member and the outer mounting member; and a liquid chamber having the elastic body as at least a part of a chamber wall, The outer mounting member is formed with a protrusion that protrudes radially toward the liquid chamber, A magnetic fluid is sealed in the liquid chamber, at least a portion of the protrusion of the outer mounting member in the circumferential direction is configured by at least a portion of an electromagnet including a yoke and an electromagnetic coil wound around the yoke, A plurality of the electromagnets are provided in the circumferential direction. According to the vibration isolation device of the present invention, the rigidity can be sufficiently changed with a simple configuration while using a magnetic fluid.

[0007] In the vibration isolation device of the present invention, Each of the plurality of electromagnets may have two radial yoke portions that form the protrusion and extend radially, a circumferential yoke portion that connects the two radial yoke portions and extends circumferentially, and an electromagnetic coil wound around the circumferential yoke portion. In this case, the vibration isolation device can be configured more simply.

[0008] In the vibration isolation device of the present invention, the yoke includes a plurality of radial yoke portions each constituting the protrusion and extending in a radial direction, and a circumferential yoke portion connecting the plurality of radial yoke portions to each other and extending over the entire circumferential direction, Each of the plurality of electromagnets may have one radial yoke portion of the plurality of radial yoke portions and an electromagnetic coil wound around the one radial yoke portion. In this case, it becomes easier to change the rigidity of the vibration isolation device more greatly.

[0009] In the vibration isolation device of the present invention, The outer mounting member incorporates a load sensor that detects an input load to the vibration isolation device and a controller, It is preferable that the controller controls the value of the current flowing through the electromagnetic coil based on the load detected by the load sensor. In this case, the rigidity of the vibration isolation device can be controlled with a simple system configuration.

[0010] In the vibration isolation device of the present invention, the outer mounting member has an actuator portion including the electromagnet and a member mounting portion that is attached to the vibration generating portion or the vibration receiving portion, It is preferable that the actuator portion and the member attachment portion are connected via the load sensor and the elastic body. In this case, failure of the load sensor can be suppressed. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a vibration-damping device that uses a magnetic fluid and is capable of sufficiently changing the rigidity with a simple configuration. [Brief explanation of the drawings]

[0012] [Figure 1] 4 is a cross-sectional view showing the vibration isolation device according to the first embodiment of the present invention, taken along line YY in FIG. 3, which includes the axis of the vibration isolation device. [Figure 2] 2A and 2B are half-sectional views with the same cross section as in FIG. 1 to explain the deformation of the vibration-damping device of FIG. 1 during operation, where FIG. 2A shows the state immediately after the damper rod has been relatively displaced downward, and FIG. 2B shows the state immediately after the damper rod has been relatively displaced upward. [Figure 3] 2 is a partial cross-sectional view of the vibration isolation device of FIG. 1 taken along line XX of FIG. 1. [Figure 4] 4 is an enlarged view of a portion A in FIG. 3 for explaining a magnetic circuit formed in the vibration isolation device of FIG. 1. FIG. [Figure 5] 7 is a half cross-sectional view showing a vibration-damping device according to a second embodiment of the present invention, taken along line ZZ in FIG. 6, which includes the axis of the vibration-damping device. [Figure 6]6 is a partial cross-sectional view showing the vibration isolation device of FIG. 5 in the same cross section as FIG. 1. [Figure 7] 7 is a half cross-sectional view showing a vibration-damping device according to a third embodiment of the present invention, taken along line ZZ in FIG. 6, which includes the axis of the vibration-damping device. [Figure 8] FIG. 8 is an explanatory diagram for explaining the overall configuration of a vibration isolation system including the vibration isolation device of FIG. [Figure 9] FIG. 8 is an equivalent model diagram for explaining the vibration isolation form of the vibration isolation device of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, vibration isolation devices according to several embodiments of the present invention will be described with reference to the drawings. In each drawing, the same members and parts are designated by the same reference numerals. In this specification, the term "axial direction" refers to a direction parallel to the axis O of the vibration damping device and is indicated by the symbol "AD" in some drawings. The term "circumferential direction" refers to a direction circumferentially around the axis O of the vibration damping device and is indicated by the symbol "CD" in some drawings. The term "radial direction" refers to a direction perpendicular to the axis O of the vibration damping device and is indicated by the symbol "RD" in some drawings. The term "radially inner" refers to the side closer to the axis O in the radial direction, and the term "radially outer" refers to the side farther from the axis O in the radial direction. Furthermore, the terms "upper" and "lower" refer to the sides that become the "upper side" and "lower side" when the vibration damping device is mounted on, for example, a vehicle. The term "yoke" in this specification collectively refers to the iron core portion around which the electromagnetic coil is wound and the yoke portion that transmits the magnetic flux generated in the iron core portion to other parts. Although the vibration isolation device 100 in the embodiment described below is configured as a strut mount, it may be configured as any type of vibration isolation device.

[0014] (First embodiment) 1 to 4 are drawings for explaining a vibration-damping device 100 according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view of the vibration-damping device according to the first embodiment of the present invention, taken along line YY in FIG. 3, which includes the axis of the vibration-damping device. FIG. 2 is a half-sectional view, taken along a cross-section similar to FIG. 1, for explaining deformation of the vibration-damping device of FIG. 1 during operation, where FIG. 2(a) is a view showing a state immediately after the damper rod has been relatively displaced downward, and FIG. 2(b) is a view showing a state immediately after the damper rod has been relatively displaced upward. FIG. 3 is a partial cross-sectional view of the vibration-damping device of FIG. 1, taken along line XX in FIG. 1. FIG. 4 is an enlarged view of part A in FIG. 3 for explaining a magnetic circuit formed in the vibration-damping device of FIG. 1.

[0015] The vibration damping device 100 according to the first embodiment of the present invention is configured as a strut mount that is placed on top of a damper such as a shock absorber of a vehicle. As shown in Figures 1 and 3, the vibration-damping device 100 according to the first embodiment of the present invention includes an inner mounting member 1, a cylindrical outer mounting member 2, a main body rubber (elastic body) 3 arranged between the inner mounting member 1 and the outer mounting member 2, and a liquid chamber 4 having the main body rubber 3 as part of the chamber wall. 1, in this embodiment, a shock absorber consisting of a damper rod 51 and a cylinder (not shown), and a bump cap 52 are connected to the lower part of the inner mounting member 1 of the vibration isolation device 100 as a strut mount with bolts B1 or the like, and a coil spring 53 is attached to the lower part of the outer mounting member 2, and the vehicle suspension device is made up of the vibration isolation device 100 as a strut mount, the shock absorber, the bump cap 52, and the coil spring 53 as a whole. However, the vibration isolation device 100 may also be configured as, for example, a cab mount attached to the cabin of a vehicle, or any other type of vibration isolation device, in which case the vibration isolation device 100 does not have to be configured as part of the suspension device described above.

[0016] As shown in FIG. 1, in this embodiment, the inner mounting member 1 is configured to be attached to a member (in this example, a damper rod 51) that serves as either a vibration generating part or a vibration receiving part. More specifically, in this embodiment, the inner mounting member 1 has a bottom portion 1a extending radially, a side portion 1b erected axially upward from the bottom portion 1a, and a top portion 1c extending radially outward from the upper end of the side portion 1b, and is configured so that the upper end of the damper rod 51 is fitted into a recess formed by the bottom portion 1a and the side portion 1b and is fitted in place by a bolt B1 or the like. The top portion 1c functions as a stopper when the vibration-damping device 100 rebounds (the state shown in FIG. 2(a) , which will be described later). In this embodiment, an upper stopper rubber 11 is fixed to the axial lower part of the top 1c of the inner mounting member 1 by means of vulcanization and / or adhesion. The upper stopper rubber 11 functions as a rebound stopper rubber that cushions impacts caused by contact between the inner mounting member 1 and an outer mounting member 2 (described later) when the vibration damping device 100 rebounds (the state shown in FIG. 2(a) (described later)). In this example, the upper stopper rubber 11 is continuous with and integral with a main body rubber 3 (described later). However, the upper stopper rubber 11 may also be formed separately from the main body rubber 3.

[0017] In this embodiment, the inner mounting member 1 is a mounting fixture and is made of metal. More specifically, the inner mounting member 1 is preferably made of a magnetic material, i.e., a metal with high magnetic permeability, so that an appropriate magnetic circuit is formed between it and the electromagnet 24 described below. More specifically, it is preferable that the inner mounting member 1 is made entirely of or contains a metal exhibiting ferromagnetism (ferromagnetic material) such as iron and / or cobalt. In this embodiment, the inner mounting member 1 is made of iron.

[0018] 1 and 3, in this embodiment, the outer mounting member 2 is a cylindrical (annular) member that is attached to the other member (e.g., the body of a vehicle, not shown) that will be the vibration generating part or the vibration receiving part with bolts B2 or the like, and is configured to support that member. The central axis of the cylindrical outer mounting member 2 corresponds to the axis O of the vibration isolation device 100. More specifically, in this embodiment, the outer mounting member 2 includes an outer mounting member main body 20 and an electromagnet 24. The outer mounting member main body 20 is preferably made of a non-magnetic material, that is, a metal or resin having a lower magnetic permeability than the metal constituting the inner mounting member 1 described above and the metal constituting the yoke 241 described below, and more specifically, is preferably made of aluminum and / or a hard resin having a certain strength. In this embodiment, the outer mounting member main body 20 is made of aluminum. In addition, in this embodiment, a lower stopper rubber 21 is fixed to the axial lower part of the outer mounting member 2 (more specifically, the outer mounting member main body 20) by means of vulcanization and / or adhesion, etc., and functions as a bound stopper rubber that cushions impacts caused by contact between the outer mounting member 2 and the lower member (more specifically, the bump cap 52 in this example) when the vibration-damping device 100 bounds (the state of Figure 2(b) described below). The configuration of the electromagnet 24 and the more specific configuration of the outer mounting member will be described in detail later.

[0019] As shown in Figures 1 to 2(a) and (b), in this embodiment, the top 1c of the inner mounting member 1 and the upper stopper rubber 11 fixed to the lower part of the top 1c, and the outer mounting member 2 and the lower stopper rubber 21 fixed to the lower part of the outer mounting member 2 each serve as stoppers when the damper rod 51 (and thus the inner mounting member 1) is relatively displaced up and down in the axial direction.

[0020] 1 and 3, in this embodiment, a main body rubber 3 serving as an elastic body is disposed between the inner mounting member 1 and the outer mounting member 2. The main body rubber 3 is fixed to each of the inner mounting member 1 (more specifically, the side portion 1b of the inner mounting member 1) and the outer mounting member 2 (more specifically, the radially inner end edge of the outer mounting member main body 20) by means of vulcanization and / or adhesive. Note that the main body rubber 3 may also be fixed to each of the inner mounting member 1 and the outer mounting member 2 via, for example, a mounting plate 32 as shown in FIG. 7.

[0021] 1, the main rubber 3 has two peaks: a peak 33a located on the axially upper side, and a peak 33b located on the axially lower side. In the example shown in the figure, the main rubber 3 is formed as a whole with the two peaks 33a and 33b connected to each other by thin rubber (rubber with a thin radial thickness), and thus the main rubber 3 has a recess 31 formed between the two peaks 33a and 33b inside the main rubber 3 itself. However, the main rubber 3 may also have the two peaks 33a and 33b not connected to each other by thin rubber, but formed as separate pieces separated from each other. However, in order to prevent impact noise and the like caused by contact between the convex portion 23 of the outer mounting member 2 described later and the inner mounting member 1 (more specifically, the side portion 1b of the inner mounting member 1) when radial input is applied to the vibration-damping device 100, it is preferable that the two ridge portions 33a and 33b of the main rubber 3 are connected to each other by the above-mentioned thin rubber.

[0022] 1 and 3, in this embodiment, the liquid chamber 4 has the main rubber 3 (elastic body) as at least a part of its chamber wall. More specifically, in the example shown in the figures, the liquid chamber 4 has the main rubber 3 and the outer mounting member 2 as its chamber wall, and even more specifically, the liquid chamber 4 is formed between the outer mounting member 2 and a recess 31 formed between two ridges 33a and 33b of the main rubber 3. However, the configuration of the liquid chamber 4 is not particularly limited as long as the main rubber 3 forms at least a part of the chamber wall; for example, the main rubber 3, the outer mounting member 2, and the inner mounting member 1 may form the chamber wall. As shown in Figure 1, in this embodiment, a convex portion 23 is provided on the outer mounting member 2 as described below, and the liquid chamber 4 is configured so that the upper liquid chamber portion 4a and the lower liquid chamber portion 4b can communicate with each other through a gap portion 4c formed between the convex portion 23 and the chamber wall radially adjacent to the convex portion 23.

[0023] 3, in this embodiment, the liquid chamber 4 exists continuously over the entire circumferential direction. In addition, in Fig. 3, the radially outer edge 4eo of the liquid chamber 4 is shown by a dotted line, but this means that the liquid chamber 4 that continues from the radially outer edge of the main rubber 3 also exists radially inward of the radially outer edge 4eo, on the back side (and front side) of the page.

[0024] 1 and 3, in this embodiment, the outer mounting member 2 is formed with a convex portion 23 that protrudes radially toward the liquid chamber 4. That is, the outer mounting member 2 has the convex portion 23. More specifically, in this embodiment, the convex portion 23 of the outer mounting member 2 is disposed axially between the ridge portions 33a and 33b on both the upper and lower sides of the main rubber 3, and ultimately within the recessed portion 31 formed in the main rubber 3 in the example shown in the figure. As a result, as described above, a gap 4c with a relatively narrow radial width in the liquid chamber 4 is formed between the convex portion 23 and the chamber wall of the liquid chamber 4 that is radially adjacent to the convex portion 23 (more specifically, in this example, the thin portion of the main rubber 3).

[0025] 3, in this embodiment, the convex portion 23 of the outer mounting member 2 extends continuously over the entire circumferential direction. However, the convex portion 23 of the outer mounting member 2 does not have to extend continuously over the entire circumferential direction. For example, in the circumferential direction, only the yoke 241 (more specifically, the radial yoke portion 241r described later) of the electromagnet 24 described later may be used as the convex portion 23 of the outer mounting member 2, and the convex portion 23 may be provided intermittently in the circumferential direction. However, from the viewpoint of more effectively changing the rigidity of the vibration damping device 100 by the magnetic fluid MF described later, it is preferable that the convex portion 23 of the outer mounting member 2 extend continuously over the entire circumferential direction, as in this embodiment.

[0026] The liquid chamber 4 is filled with a magnetic fluid MF. The magnetic fluid MF is a fluid whose viscosity increases when placed in a magnetic field and whose viscosity changes depending on the applied magnetic field. In this embodiment, the magnetic fluid MF is sealed in the liquid chamber 4, and therefore, by appropriately controlling the magnetic field (magnetic flux density) applied to the magnetic fluid MF, the viscosity of the magnetic fluid MF in the liquid chamber 4 can be changed, thereby changing and controlling the stiffness and therefore the damping force of the vibration control device 100. Examples of magnetic fluids MF include MR fluids in which iron particles having an average particle size of 0.5 μm or more, preferably 1.0 μm or more, are dispersed at a high concentration in a liquid such as ethylene glycol or polyα-olefin.

[0027] As shown in Figures 1 and 3, in this embodiment, at least a portion of the circumferential direction of the protrusion 23 of the outer mounting member 2 is constituted by at least a portion of an electromagnet 24 including a yoke 241 and an electromagnetic coil 242 wound around the yoke 241. 3, in this embodiment, at least a portion (in this example, a portion) of the circumferential direction of the protrusion 23 of the outer mounting member 2 (a portion of the outer mounting member 2 radially inward from the radially outer edge 4eo of the liquid chamber 4 in FIG. 3) is constituted by a yoke 241 (more specifically, a radial yoke portion 241r described later), which is at least a portion (in this example, a portion) of the electromagnet 24. More specifically, as shown in FIG. 3, in this example, the protrusion 23 is constituted by twelve radial yoke portions 241r in the circumferential direction and the outer mounting member main body portion 20 interposed therebetween. As described above, for example, in the circumferential direction, when only the yoke 241 (more specifically, the radial yoke portion 241r) of the electromagnet 24 described later is used as the convex portion 23 of the outer mounting member 2 and the convex portion 23 is provided intermittently in the circumferential direction, the entire circumferential portion of the convex portion 23 of the outer mounting member 2 is constituted by at least a part of the electromagnet 24.

[0028] In this specification, the term "electromagnet" refers to an entity including a yoke and an electromagnetic coil wound around the yoke. As shown in FIGS. 1 and 3, in this embodiment, the electromagnet 24 includes a yoke 241 and an electromagnetic coil 242 wound around the yoke 241. In this embodiment, a plurality of electromagnets 24 are provided in the circumferential direction. More specifically, in the example of Fig. 3, the electromagnets 24 are provided on the outer mounting member 2, and six electromagnets 24 are provided along the circumferential direction at equal intervals. However, the number of electromagnets 24 is not particularly limited as long as there is a plurality, and there may be two to five, or seven or more electromagnets in the circumferential direction. However, from the viewpoint of more effectively changing the rigidity of the vibration damping device 100 by the magnetic fluid MF, it is preferable that six or more electromagnets 24 are provided in the circumferential direction, and it is more preferable that six to ten electromagnets 24 are provided in the circumferential direction. In this embodiment, as shown in Fig. 3, the shapes and sizes of the multiple (six in the example of Fig. 3) electromagnets 24 (and therefore the yokes 241 and the electromagnetic coils 242) are all the same. However, the shapes or sizes of the multiple electromagnets 24 (and therefore the yokes 241 and the electromagnetic coils 242) may differ between at least two of the electromagnets 24. However, from the viewpoints of making the magnitude of the magnetic field (magnetic flux) applied to the magnetic fluid MF in the liquid chamber 4 as uniform as possible in the circumferential direction and simplifying the configuration and ease of manufacture of the vibration damping device 100, it is preferable that the shapes and sizes of the multiple electromagnets 24 (and therefore the yokes 241 and the electromagnetic coils 242) are all the same, as in this embodiment. As described above, in this embodiment, the plurality of electromagnets 24 are arranged at equal intervals in the circumferential direction, as shown in Fig. 3. However, the plurality of electromagnets 24 do not have to be arranged at equal intervals in the circumferential direction. However, from the same viewpoint as above, it is preferable that the plurality of electromagnets 24 be arranged at equal intervals in the circumferential direction, as in this embodiment.

[0029] The yoke 241 is preferably made of a magnetic material, i.e., a metal with high magnetic permeability, so that an appropriate magnetic circuit is formed between the yoke 241 and the inner mounting member 1. More specifically, it is preferably made entirely of or contains a metal exhibiting ferromagnetism (a ferromagnetic material) such as iron and / or cobalt. In this embodiment, the yoke 241 is made of iron.

[0030] Referring to FIG. 3, in this embodiment, each of the plurality of electromagnets 24, that is, one electromagnet 24, has two radial yoke portions 241r, a circumferential yoke portion 241c, and an electromagnetic coil 242.

[0031] In this embodiment, the two radial yoke portions 241r each constitute the convex portion 23 (more specifically, at least a part of the circumferential direction of the convex portion 23) of the aforementioned outer mounting member 2. That is, the tip side (the radially inner end side) of the radial yoke portion 241r protrudes radially toward the liquid chamber 4. The two radial yoke portions 241r extend in the radial direction. Here, in this specification, "extending in the radial direction" does not only mean extending along the radial direction, which is the extension direction of a straight line passing through the axis O (i.e., at an angle of 0° with respect to the radial direction), in a plan view (see FIG. 3) of the vibration damping device 100 projected from the direction of the axis O, but also includes extending in a direction that has a radial component and is inclined at a relatively small angle with respect to the radial direction (for example, an angle of 45° or less, preferably 30° or less, and more preferably 15° or less) in a plan view. As shown in FIG. 3, in this embodiment, each radial yoke portion 241r extends in a direction inclined at an angle of approximately 15° with respect to the radial direction.

[0032] In this embodiment, the circumferential yoke portion 241c connects the two radial yoke portions 241r together (more specifically, the radially outer ends of the two radial yoke portions 241r). The yoke 241 is formed such that the two radial yoke portions 241r and the circumferential yoke portion 241c are continuously formed and integrated. The circumferential yoke portion 241c extends in the circumferential direction. In this specification, "extending in the circumferential direction" refers not only to extending along the circumferential direction, which is the extension direction of a circle centered on the axis O (i.e., in an arc shape along the circumferential direction), in a plan view (see FIG. 3) of the anti-vibration device 100 projected from the direction of the axis O, but also to extending in a tangential direction to the circle or at a relatively small angle (for example, 45° or less, preferably 30° or less, more preferably 15° or less) relative to the tangential direction of the circle. As shown in FIG. 3, in this embodiment, the circumferential yoke portion 241c extends in a tangential direction to the circle.

[0033] In this embodiment, the electromagnetic coil 242 is wound around the circumferential yoke portion 241c of the yoke 241. There are no particular restrictions on the number of turns of the electromagnetic coil, but from the perspective of more effectively changing the rigidity of the vibration damping device 100 with the magnetic fluid MF, it is preferable that the number of turns is as large as possible.

[0034] In the vibration-damping device 100 of this embodiment configured as described above, the current flowing through the electromagnetic coil 242 is controlled, for example, by a controller provided outside the vibration-damping device 100 (for example, on the vehicle body side) via a lead wire (not shown) connected to the electromagnetic coil 242.

[0035] Next, the operation and control method of the vibration isolation device 100 according to this embodiment having the above-described configuration will be described with reference to FIGS. 2(a), 2(b), 4, etc. Figure 2 is a half-sectional view illustrating deformation during operation of the vibration isolation device 100 according to this embodiment, with Figure 2(a) showing the state immediately after the damper rod has been relatively displaced downward, and Figure 2(b) showing the state immediately after the damper rod has been relatively displaced upward. Note that in Figures 2(a) and 2(b), the right half of the vibration isolation device 100 has the same configuration as the left half shown. 2(a) and 2(b), as described above, the liquid chamber 4 is filled with a magnetic fluid MF. As shown in FIG. 2(a), when the damper rod 51 and, therefore, the inner mounting member 1 are displaced (moved) axially downward relative to the outer mounting member 2 due to up-and-down vehicle movement (indicated by the thick arrow in the figure), the magnetic fluid MF in the upper liquid chamber 4a (see FIG. 1) passes through the gap 4c (see FIG. 1) and moves toward the lower liquid chamber 4b. On the other hand, as shown in FIG. 2(b), when the damper rod 51 and, therefore, the inner mounting member 1 are displaced (moved) axially upward relative to the outer mounting member 2 due to up-and-down vehicle movement (indicated by the thick arrow in the figure), the magnetic fluid MF in the lower liquid chamber 4b (see FIG. 1) passes through the gap 4c (see FIG. 1) and moves toward the upper liquid chamber 4a. This movement of the magnetic fluid MF through the gap 4c generates a certain damping force. Furthermore, when current is passed through the electromagnetic coil 242 of the electromagnet 24 during the above-mentioned relative displacement, the magnetic flux generated in the electromagnet 24 passes through the magnetic fluid MF, increasing the viscosity of the magnetic fluid MF, thereby increasing the reaction force that displaces the damper rod 51 and therefore the inner mounting member 1 up and down in the axial direction, and ultimately increasing the rigidity of the vibration-damping device 100. Furthermore, the viscosity of the magnetic fluid MF increases as the magnitude (current value) of the current passed through the electromagnetic coil 242 increases. Therefore, by controlling the magnitude (current value) of the current passed through the electromagnetic coil 242, the rigidity of the vibration-damping device 100 can be varied as needed, and ultimately the rigidity of the vibration-damping device 100 can be suitably controlled.

[0036] The above describes the case where a force is applied to the inner mounting member 1 in the vertical direction, causing a relative displacement in the vertical direction between the inner mounting member 1 and the outer mounting member 2. However, even if a force is applied to the inner mounting member 1 in the radial direction (for example, in the front-to-rear and / or left-to-right direction of the vehicle) and a relative displacement in the radial direction occurs between the inner mounting member 1 and the outer mounting member 2, the magnetic fluid MF held in the liquid chamber 4 including the gap portion 4c can increase the rigidity of the vibration-damping device 100, particularly in the radial direction, and can suppress the relative displacement in the radial direction.

[0037] The current value flowing through the electromagnetic coil 242 can be controlled by a controller provided outside the vibration damping device 100 (for example, on the vehicle body side), or inside the vibration damping device 100 as in the third embodiment described below with reference to Figures 7 to 9. For example, when the vehicle is traveling on a good road with little up-and-down movement of the vehicle, the reaction force of the damper rod 51 (the damping force of the shock absorber) is not high, so the controller does not pass current to the electromagnetic coil 242 or reduces the value of the current passed through the electromagnetic coil 242, thereby reducing the rigidity of the vibration control device 100, thereby reducing the transmission of high-frequency vibrations such as road noise. On the other hand, when the vehicle is traveling on a rough road with significant shaking, or when the driver operates the steering wheel and the vehicle turns, the controller passes current to the electromagnetic coil 242 or increases the value of the current passed through the electromagnetic coil 242, thereby increasing the rigidity of the vibration control device 100, thereby actively utilizing the damping force of the shock absorber, including the damper rod 51, to suppress vibration. This control of the current value by the controller results in improved NV performance (noise and vibration suppression performance) without sacrificing handling stability and ride comfort. Here, which of the above-mentioned situations the vehicle is in can be determined based on the load detected by a load sensor, as in a third embodiment described later with reference to Figures 7 to 9. Furthermore, the value of the current flowing through the electromagnet 24 may be continuously controlled (i.e., continuously changed) or intermittently controlled (i.e., intermittently changed) by a controller.

[0038] FIG. 4 is an enlarged view of a portion A in FIG. 3 for explaining a magnetic circuit formed in the vibration isolation device of FIG. In the vibration-damping device 100 according to this embodiment shown in Figures 1 and 3, when current is passed through the electromagnetic coil 242 of the electromagnet 24, the yoke 241 (i.e., the two radial yoke portions 241r and the circumferential yoke portion 241c) is magnetized, and as a result, as shown in Figure 4 (in Figure 4, only the magnetic field lines ML generated outside the electromagnet 24 are shown), the magnetic field lines ML pass through the circumferential yoke portion 241c of the electromagnet 24 (not shown in Figure 4), the radial yoke portion 241r (241ra (see also Figure 3)) on one circumferential side of the same electromagnet 24, the inner mounting member 1, the radial yoke portion 241r (241rb (see also Figure 3)) on the other circumferential side of the same electromagnet 24, and the original circumferential yoke portion 241c of the same electromagnet in this order, forming a magnetic circuit between them. As partially shown in the upper part of Figure 4, the magnetic field lines ML also pass through the circumferential yoke portion 241c of one electromagnet 24 (not shown in Figure 4), the radial yoke portion 241r (241ra (see also Figure 3)) on one circumferential side of the electromagnet 24, the radial yoke portion 241r (241rb (see also Figure 3)) on the other circumferential side of another electromagnet 24 circumferentially adjacent to the electromagnet 24 (not shown in Figure 4), and the original circumferential yoke portion 241c of the original electromagnet 24, and a magnetic circuit is also formed between these. Therefore, in this embodiment, the liquid chamber 4 provided between the radial yoke portion 241r and the inner mounting member 1, and thus the magnetic fluid MF sealed in the liquid chamber 4, are placed on a magnetic circuit and a magnetic field is applied, and the viscosity can be increased or changed by passing an electric current through the electromagnetic coil 242 of the electromagnet 24.

[0039] In this embodiment, as shown in FIG. 4, the vibration damping device 100 is preferably configured and / or controlled so that the circumferentially adjacent radial yoke portions 241ra and 241rb (more specifically, the respective tip ends (radially inner ends) of the radial yoke portions 241ra and 241rb) have opposite polarities. Here, "circumferentially adjacent radial yoke portions 241ra and 241rb" includes both the radial yoke portions 241ra and 241rb that are circumferentially adjacent to each other within the same electromagnet 24, and the radial yoke portions 241ra and 241rb that are circumferentially adjacent to each other within different circumferentially adjacent electromagnets 24 (see FIG. 3). In this case, the magnetic field lines (magnetic flux) generated by passing a current through the electromagnetic coil 242 of the electromagnet 24 are not canceled out, and the magnitude of the magnetic field (magnetic flux density) applied to the magnetic fluid MF in the liquid chamber 4 can be more effectively increased. In this embodiment, as shown in FIG. 4, the vibration-damping device 100 is configured and / or controlled so that the radial yoke portion 241ra (more specifically, the tip portion (radially inner end portion) of the radial yoke portion 241ra) is the north pole, and the radial yoke portion 241rb (more specifically, the tip portion (radially inner end portion) of the radial yoke portion 241rb) is the south pole. However, the vibration isolation device 100 does not have to be configured and / or controlled so that the radial yoke portions 241ra and 241rb adjacent in the circumferential direction have opposite poles.

[0040] In this embodiment, as described above, in order to make the radial yoke portions 241ra and 241rb adjacent in the circumferential direction have different poles from each other, for example, in multiple (six in the example of Figure 3) electromagnets 24, the way in which each electromagnetic coil 242 is wound around the yoke 241 (whether it is right-handed or left-handed when viewed from one side in the circumferential direction) and / or the direction of the current flowing in each electromagnetic coil 242 (whether it is the same direction or different directions when viewed in the circumferential direction) can be adjusted. For example, in this embodiment, the winding method of each of the electromagnetic coils 242 in the multiple electromagnets 24 may be the same (clockwise or counterclockwise as viewed from one side in the circumferential direction). In this case, simply by controlling the direction of the current flowing through each of the electromagnetic coils 242 in the multiple electromagnets 24 to be the same (same direction as viewed in the circumferential direction), the radial yoke portions 241ra and 241rb adjacent in the circumferential direction can be made to have opposite poles. However, there are no particular limitations on the configuration or control method for making the radial yoke portions 241ra and 241rb adjacent in the circumferential direction have opposite poles.

[0041] Next, the main effects of the above-described embodiment will be described below. First, in this embodiment, the outer mounting member 2 is formed with a convex portion 23 that protrudes radially toward the liquid chamber 4, and the liquid chamber 4 is filled with a magnetic fluid MF. At least a portion of the convex portion 23 of the outer mounting member 2 in the circumferential direction is composed of at least a portion of an electromagnet 24 including a yoke 241 and an electromagnetic coil 242 wound around the yoke 241, and multiple electromagnets 24 are provided in the circumferential direction. That is, according to this embodiment, a magnetic fluid MF is sealed in the liquid chamber 4, and at least a portion of the convex portion 23 protruding toward the liquid chamber 4 of the outer mounting member 2 is formed by a part of the electromagnet 24 including the electromagnetic coil 242. Therefore, by passing an electric current through the electromagnetic coil 242, the viscosity of the magnetic fluid MF in the liquid chamber 4 can be changed, and ultimately the rigidity of the vibration-damping device 100 can be changed. Furthermore, according to this embodiment, the outer mounting member 2 has a protrusion 23 that protrudes toward the liquid chamber, and at least a portion of the protrusion 23 is simply configured as at least a portion of the electromagnet 24. Therefore, compared to a case where, for example, a partition wall is provided to divide the liquid chamber into two, and a single electromagnet consisting of a circumferential passage, a yoke, and an electromagnetic coil is formed within the partition wall, the structure of the vibration-damping device 100 is simpler, and the structure of the vibration-damping device 100 does not become more complex even when the number of electromagnets is increased in order to achieve sufficient rigidity change. Furthermore, according to this embodiment, since multiple electromagnets 24 (and thus electromagnetic coils 242) are provided in the circumferential direction, the magnitude of the magnetic field (magnetic flux density) applied to the magnetic fluid MF in the liquid chamber 4 can be sufficiently increased, and therefore the rigidity of the vibration-damping device 100 can be sufficiently increased and / or sufficiently changed. As described above, the vibration isolation device 100 according to this embodiment can sufficiently change the rigidity with a simple configuration while using magnetic fluid.

[0042] In this embodiment, each of the multiple electromagnets 24 has two radial yoke portions 241r that form the protrusions 23 and extend radially, a circumferential yoke portion 241c that connects the two radial yoke portions 241r and extends circumferentially, and an electromagnetic coil 242 wound around the circumferential yoke portion 241c. In this case, the electromagnets 24 have a simple shape, that is, an electromagnetic coil 242 wound around a yoke 241 that is U-shaped when viewed from above, and multiple electromagnets 24 are arranged in the circumferential direction, which makes the configuration of the vibration-damping device 100 simpler.

[0043] In this embodiment, the plurality of electromagnets 24 (and in turn the yokes 241 and the electromagnetic coils 242) provided in the circumferential direction all have the same shape and size. In this case, the vibration isolation device 100 has a simpler configuration and is easier to manufacture.

[0044] Furthermore, in this embodiment, one electromagnet 24 has two radial yoke portions 241r, and a plurality of such electromagnets 24 are provided in the circumferential direction. That is, in this embodiment, the total number of radial yoke portions 241r in the entire circumferential direction is an even number. In this case, for example, by simply controlling the winding method of each electromagnetic coil 242 in the multiple electromagnets 24 to be the same (right-handed or left-handed when viewed from one side in the circumferential direction) and the direction of the current flowing through each electromagnetic coil 242 in the multiple electromagnets 24 to be the same (same direction when viewed in the circumferential direction), the radial yoke portions 241r adjacent to each other in the circumferential direction (more specifically, the tip ends (radially inner ends) of the radial yoke portions 241r) will always have opposite poles, and thus the magnitude of the magnetic field (magnetic flux density) applied to the magnetic fluid MF in the liquid chamber 4 can be more effectively increased.

[0045] In addition, in this embodiment, the upper stopper rubber 11 fixed to the top 1c of the inner mounting member 1 and the lower part of the top 1c, and the lower stopper rubber 21 fixed to the outer mounting member 2 and the lower part of the outer mounting member 2, each serve as stoppers when the damper rod 51 (and thus the inner mounting member 1) is displaced relatively up and down in the axial direction. In this case, especially when the vibration-damping device 100 receives a large input in the vertical direction, excessive vertical stroke of the damper rod 51 (and thus the inner mounting member 1) is suppressed, and the damping force of the shock absorber including the damper rod 51 can be sufficiently transmitted to the vehicle body, etc. supported by the vibration-damping device 100.

[0046] (Second embodiment) Next, a vibration isolation device 100 according to a second embodiment of the present invention will be described with reference to Figures 5 and 6. In the second embodiment, the same members or parts as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted. The vibration control device 100 according to the second embodiment of the present invention differs from the vibration control device 100 according to the first embodiment of the present invention only in the configuration of the electromagnet 24, and is otherwise substantially the same as the vibration control device 100 according to the first embodiment. The following description will mainly focus on the differences from the first embodiment.

[0047] Fig. 5 is a half cross-sectional view showing an anti-vibration device according to a second embodiment of the present invention, taken along line ZZ in Fig. 6, which includes the axis of the anti-vibration device. Fig. 6 is a partial cross-sectional view showing the anti-vibration device of Fig. 5 in the same cross section as Fig. 1. In Fig. 5, the right half of the anti-vibration device 100 has the same configuration as the left half shown. 5 and 6, in this embodiment, the yoke 241 of the electromagnet 24 includes a plurality of radial yoke portions 241r that each form the protrusion 23 of the outer mounting member 2 and extend radially, and a circumferential yoke portion 241c that connects the plurality of radial yoke portions 241r together and extends in the entire circumferential direction (i.e., the entire circumference).

[0048] More specifically, in this embodiment, the multiple radial yoke portions 241r extend radially, similarly to the first embodiment, and form the protrusions 23 (more specifically, at least a portion of the protrusions 23 in the circumferential direction) of the outer mounting member 2. That is, the distal ends (diametrically inner ends) of the radial yoke portions 241r protrude radially toward the liquid chamber 4. Also, as shown in FIG. 6, a large number of radial yoke portions 241r (24 in the example of FIG. 6) are provided radially (i.e., along the radial direction) around the axis O, at equal intervals from one another in the circumferential direction. Furthermore, in this embodiment, the circumferential yoke portion 241c extends in the circumferential direction, similar to the first embodiment, and connects the multiple radial yoke portions 241r (more specifically, the radial outer ends of the multiple radial yoke portions 241r) together, but unlike the first embodiment, the circumferential yoke portion 241c extends throughout the entire circumferential direction. The radial yoke portions 241r and the circumferential yoke portions 241c may be formed separately and connected to each other by welding or the like, or may be formed as a continuous, integrated unit. Furthermore, the radial yoke portions 241r and the circumferential yoke portions 241c may simply be in contact with each other. In this embodiment, the material of the yoke 241 is the same as that of the first embodiment described above.

[0049] Also, referring to Figure 6, in this embodiment, each of the multiple electromagnets 24 has one radial yoke portion 241r among the multiple radial yoke portions 241r described above, and an electromagnetic coil 242 wound around that one radial yoke portion 241r. Thus, in this embodiment, unlike the first embodiment, the electromagnetic coil 242 is wound around the radial yoke portion 241r instead of the circumferential yoke portion 241c. In this specification, each electromagnet 24 having one coil is counted as one.

[0050] According to the vibration-damping device 100 of this embodiment configured as described above, the electromagnetic coil 242 is wound around a large number of radial yoke portions 241r arranged radially around the axis O. Therefore, compared to the vibration-damping device 100 of the first embodiment described above, for example, it is possible to increase the number of electromagnetic coils 242 and / or the total number of turns of the electromagnetic coil 242 (winding the electromagnetic coil around the radial yoke portion 241r rather than the circumferential yoke portion 241c allows the total length of the yoke portion that can be wound to be longer) in a limited space, and ultimately it becomes easier to change the rigidity of the vibration-damping device 100 more significantly. Other configurations and effects of the vibration isolation device 100 of this embodiment are similar to those of the vibration isolation device 100 of the first embodiment described above.

[0051] In this embodiment, as in the first embodiment, it is preferable that the vibration-damping device 100 be configured and / or controlled so that circumferentially adjacent radial yoke portions 241r (more specifically, the tip ends (radially inner ends) of the radial yoke portions 241r) have opposite polarities. 6, for example, it is preferable that one radial yoke portion 241r on which no electromagnetic coil 242 is wound is provided between two circumferentially adjacent radial yoke portions 241r on which an electromagnetic coil 242 is wound. In this case, for example, by simply controlling the winding methods of the plurality of electromagnetic coils 242 to be the same (clockwise or counterclockwise as viewed from the axis O side) and the directions of the currents flowing through the plurality of electromagnetic coils 242 to be the same (same direction as viewed radially from the axis O), the circumferentially adjacent radial yoke portions 241r (more specifically, the tip ends (radially inner ends) of the radial yoke portions 241r) have opposite polarities, and thus the magnitude of the magnetic field (magnetic flux density) applied to the magnetic fluid MF in the liquid chamber 4 can be more effectively increased.

[0052] (Third embodiment) Next, a vibration isolation device 100 according to a third embodiment of the present invention will be described with reference to Figures 7 to 9. In the third embodiment, the same members or parts as those in the second embodiment will be denoted by the same reference numerals and the description thereof will be omitted. The vibration-damping device 100 according to the third embodiment of the present invention differs from the vibration-damping device 100 according to the second embodiment of the present invention only in the configuration of the outer mounting member 2, and is otherwise substantially the same as the vibration-damping device 100 according to the second embodiment. The following description will mainly focus on the differences from the second embodiment.

[0053] Fig. 7 is a half cross-sectional view showing an anti-vibration device according to a third embodiment of the present invention, taken along line ZZ in Fig. 6, which includes the axis of the anti-vibration device. Fig. 8 is an explanatory diagram for explaining the overall configuration of a vibration isolation system including the anti-vibration device of Fig. 7. Fig. 9 is an equivalent model diagram for explaining the vibration isolation form of the anti-vibration device of Fig. 7. As shown in Figures 7 and 8, in this embodiment, the outer mounting member 2 has a built-in load sensor 6 and a control unit 7. As shown in Figure 8, the control unit 7 is made up of a controller 71 and an amplifier 72. Therefore, in this embodiment, the outer mounting member 2 has a built-in load sensor 6 and a built-in controller 71. Note that "built-in" means that the target member does not necessarily have to be completely buried in the outer mounting member 2, but may be held within the outer mounting member 2, rather than outside the outer mounting member 2.

[0054] The vibration isolation form of the vibration isolation device 100 of this embodiment including the load sensor 6 can be modeled using a mass element M, a damper element C, and a spring element K as shown in FIG. In FIG. 9, the damper element C corresponds to the magnetic fluid MF sealed in the liquid chamber 4.

[0055] The load sensor 6 detects an input load to the vibration-damping device 100. More specifically, in this embodiment, the load sensor 6 detects a load input to an actuator section 2a side (described later) of the outer mounting member 2, as shown in FIG. 7. The configuration and type of the load sensor 6 are not particularly limited as long as it can detect an input load to the vibration-damping device 100. The load sensor 6 may be, for example, a load cell, a piezoelectric element, or the like, or may also be a Hall element, a capacitance sensor, or the like that converts from a relative distance. The controller 71, for example, executes a program stored in the controller 71 to instruct and control the current that the amplifier 72 passes through the electromagnetic coil 242. The controller 71 may be configured to include one or more processors such as a CPU (Central Processing Unit). Communication between the controller 71 and the amplifier 72 or other components may be wired communication or wireless communication. The amplifier 72 applies a current to the electromagnetic coil 242 in accordance with an instruction from the controller 71 . 7, the vibration isolation system including the vibration isolation device 100 of this embodiment may be provided with a power supply 8 for starting up the control unit 7 (controller 71 and amplifier 72) outside the vibration isolation device 100 (for example, on the body of the vehicle). However, the power supply 8 may also be built into the vibration isolation device 100.

[0056] In this embodiment, the controller 71 controls the value of the current flowing through the electromagnetic coil 242 based on the load detected by the load sensor 6 (hereinafter also referred to as the "detected load"). More specifically, the controller 71 can control the current value using the detection load, for example, in the following manner. For example, when the detected load determines that the load input to the vehicle is small (for example, when the vehicle is traveling on a good road and there is little up and down movement of the vehicle), no current is passed or the current value is significantly reduced, thereby reducing the rigidity of the vibration isolation device 100 and suppressing the transmission of high-frequency vibrations such as road noise. On the other hand, if the detected load indicates that the load input to the vehicle is large (for example, when the vehicle is traveling on a rough road that causes large vibrations, or when the driver is operating the steering wheel and turning the vehicle), the current value is increased and the rigidity of the vibration control device 100 is increased, thereby actively utilizing the damping force of the shock absorber, including the damper rod 51, to suppress vibration. In this case, a coefficient that enables efficient utilization of the damping force of the shock absorber may be set and adjusted to optimize the input load and rigidity. This coefficient may be linear or nonlinear. More specifically, the damping force of the shock absorber is largely due to friction, especially when a small input is applied. Furthermore, the viscous damping caused by the oil in the shock absorber also has nonlinear characteristics due to the valve. Therefore, it may be better to adjust the coefficient to achieve an input-output relationship that optimizes the combination of these factors. Furthermore, for example, when the detected load determines that the load input to the vehicle is a medium input between the small input and the large input (for example, when the vehicle is traveling on a normal road surface), the current value is adjusted so that the vibration isolation device 100 exerts a damping force proportional to the detected load. Here, the determination of whether the load input is a small input, a large input, or a medium input can be made using, for example, the amplitude of the detection load or the frequency of the amplitude fluctuation of the detection load. When this determination is made using the amplitude of the detection load, for example, it may be determined that the input is a small input when the amplitude is 2N or less, a large input when it is 10 to 20N, and a medium input when it is an intermediate value between these. Furthermore, when this determination is made using the frequency of the amplitude fluctuation of the detection load, for example, it may be determined that the input is a small input when the frequency is 25Hz or more, a large input when it is 5Hz or less, and a medium input when it is an intermediate value between these.

[0057] In this embodiment, as shown in FIG. 7, the outer mounting member 2 has an actuator portion 2a including an electromagnet 24, and a member mounting portion 2b that is attached to a vibration generating portion or a vibration receiving portion. 7, the actuator section 2a of the outer mounting member 2 is a section that is disposed radially inward from the component mounting section 2b as a whole, and includes an electromagnet 24. On the other hand, the component mounting section 2b of the outer mounting member 2 is a section that is disposed radially outward from the actuator section 2a as a whole. In this embodiment, the component mounting section 2b has a built-in control unit 7.

[0058] 7, the actuator part 2a and the member mounting part 2b are connected via the load sensor 6 and an elastic body made up of the connecting rubber 22 and the lower stopper rubber 21. In other words, the load sensor 6 and the elastic body are interposed between the actuator part 2a and the member mounting part 2b. 7, the load sensor 6 is fixed via a mounting plate 61 between a protrusion 2ap that protrudes radially outward from the upper end of the actuator portion 2a and a protrusion 2bp that protrudes radially inward from the lower end of the component mounting portion 2b. The connecting rubber 22, which forms part of the elastic body, has a portion that extends radially and a portion that extends axially, and is fixed between the actuator portion 2a and the protrusion 2bp of the component mounting portion 2b. Furthermore, at least a portion of the connecting rubber 22 and the lower stopper rubber 21 that form the elastic body, including at least the connecting rubber 22, is made of a rubber with relatively high rigidity.

[0059] According to the vibration-damping device 100 of this embodiment configured as described above, the outer mounting member 2 incorporates a load sensor 6 and a controller 71, and the controller 71 controls the current value flowing through the electromagnetic coil 242 based on the load detected by the load sensor 6. Therefore, there is no need to separately install the controller 71 or the like outside the vibration-damping device 100 using, for example, complex wiring or many terminals, and the vibration-damping device 100 alone, excluding the power supply 8, etc., can control the rigidity according to the input load. In other words, the rigidity of the vibration-damping device 100 can be controlled with a simple system configuration.

[0060] Furthermore, according to this embodiment, the actuator portion 2a and the member mounting portion 2b of the outer mounting member 2 are connected via the load sensor 6 and the elastic body. In this case, compared to when only the load sensor 6 is interposed between the actuator part 2a and the member mounting part 2b, part of the input load is borne by the elastic body, and not all of the input load is borne by the load sensor 6. Therefore, in this case, failure of the load sensor 6 can be suppressed. Other configurations and effects of the vibration isolation device 100 of this embodiment are similar to those of the vibration isolation device 100 of the second embodiment described above.

[0061] The foregoing describes exemplary embodiments of the present invention, and various modifications can be made without departing from the scope of the claims. [Industrial Applicability]

[0062] The vibration-damping device of the present invention can be suitably used as any vibration-damping device, and in particular can be suitably used as, for example, a strut mount placed on top of a damper such as a shock absorber of a vehicle, or a cab mount attached to the cabin of a vehicle. [Explanation of symbols]

[0063] 1: inner mounting member, 1a: bottom, 1b: side, 1c: top, 11: Upper stopper rubber, 2: outer mounting member, 2a: actuator portion, 2ap: protrusion portion, 2b: member mounting portion; 2bp: protrusion; 20: outer mounting member main body; 21: Lower stopper rubber (elastic body), 22: Connecting rubber (elastic body), 23: Convex portion, 24: electromagnet, 241: yoke, 241c: circumferential yoke portion, 241r, 241ra, 241rb: radial yoke portion, 242: electromagnetic coil, 3: Main body rubber (elastic body), 31: Recess, 32: Mounting plate, 33a, 33b: Yamabe, 4: liquid chamber, 4a: upper part of liquid chamber, 4b: lower part of liquid chamber, 4c: gap, 4eo: radially outer end, 51: Damper rod, 52: Bump cap, 53: Coil spring, 6: Load sensor, 61: Mounting plate, 7: Control unit, 71: Controller, 72: Amplifier, 8: Power, 100: vibration isolation device, AD: Axial direction, B1, B2: Bolt, C: Damper element, CD: Circumferential direction, K: spring element, M: mass element, MF: magnetic fluid, ML: magnetic field line, O: axis line, RD: Radial direction

Claims

1. 1. A vibration-damping device comprising: an inner mounting member; a cylindrical outer mounting member; an elastic body disposed between the inner mounting member and the outer mounting member; and a liquid chamber having the elastic body as at least a part of a chamber wall, The outer mounting member is formed with a protrusion that protrudes radially toward the liquid chamber, A magnetic fluid is sealed in the liquid chamber, at least a portion of the protrusion of the outer mounting member in the circumferential direction is configured by at least a portion of an electromagnet including a yoke and an electromagnetic coil wound around the yoke, A vibration-damping device, wherein a plurality of the electromagnets are provided in the circumferential direction.

2. 2. The vibration-damping device of claim 1, wherein each of the plurality of electromagnets has two radial yoke portions that form the protrusion and extend radially, a circumferential yoke portion that connects the two radial yoke portions and extends circumferentially, and an electromagnetic coil wound around the circumferential yoke portion.

3. the yoke includes a plurality of radial yoke portions each constituting the protrusion and extending in a radial direction, and a circumferential yoke portion connecting the plurality of radial yoke portions to each other and extending over the entire circumferential direction, 2. The vibration-damping device according to claim 1, wherein each of the plurality of electromagnets has one radial yoke portion among the plurality of radial yoke portions and an electromagnetic coil wound around the one radial yoke portion.

4. The outer mounting member incorporates a load sensor that detects an input load to the vibration isolation device and a controller, 4. The vibration isolation device according to claim 1, wherein the controller controls a value of a current flowing through the electromagnetic coil based on the load detected by the load sensor.

5. the outer mounting member has an actuator portion including the electromagnet and a member mounting portion that is attached to the vibration generating portion or the vibration receiving portion, The vibration-damping device according to claim 4 , wherein the actuator portion and the member mounting portion are connected via the load sensor and the elastic body.

Images