JP2021131092A - Active type anti-vibration device - Google Patents

Abstract

To provide an active type anti-vibration device capable of reduction in size.SOLUTION: A mount bush 10 has first and second liquid chambers 54, 56 formed fluid-tightly, and an intermediate plate 36 arranged while being sandwiched in an axial direction by first and second magnetic members 40, 42 of an outer magnetic material core 34. The first magnetic member 40 has a first communication passage 58 having one end opened to the first liquid chamber 54, and the second magnetic member 42 has a second communication passage 60 having one end opened to the second liquid chamber 56. The intermediate plate 36 has a third communication passage 62 that has one end connected to the other end of the first communication passage 58 and the other end connected to the other end of the second communication passage 60. A magnetic viscous fluid 64 is filled in the first and second liquid chambers 54, 56 and the first, second and third communication passages 58, 60, 62.SELECTED DRAWING: Figure 3

Description

The present invention relates to an active vibration isolator having a ferrofluid.

In the following Patent Document 1, a first fluid chamber and a second fluid chamber partitioned by a piston are provided inside the cylinder, and a fluid passage communicating the first fluid chamber and the second fluid chamber with the piston is axially oriented. A damper that extends to and is disclosed. A magnetic viscous fluid is sealed in the first fluid chamber, the second fluid chamber, and the fluid passage, and the viscosity of the magnetic viscous fluid changes by energizing a coil provided inside the piston.

Japanese Unexamined Patent Publication No. 2006-07777

In Patent Document 1, since the fluid passage communicating between the first fluid chamber and the second fluid chamber is formed so as to extend in the axial direction, there is a problem that the damper becomes large in the axial direction.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an active vibration isolator capable of miniaturization.

In an aspect of the present invention, an inner member having an inner magnetic core formed so as to extend in the axial direction and an inner member formed so as to extend coaxially with the inner member so as to surround a radial outer peripheral portion of the inner magnetic core. An outer member having an arranged outer magnetic core, an electromagnetic coil provided on one of the inner magnetic core and the outer magnetic core to generate a magnetic field, an outer peripheral surface of the inner member, and an inner side of the outer member. An active anti-vibration device having a liquid-tightly formed first liquid chamber and a second liquid chamber, which are arranged apart from each other with the peripheral surface, and the outer magnetic core is a magnetic material core. A non-magnetic member having a first magnetic member and a second magnetic member separate from the first magnetic member, and arranged so as to be axially sandwiched between the first magnetic member and the second magnetic member. The first magnetic member has a member, the first magnetic member has a first passage that opens to the first liquid chamber at one end, and the second magnetic member has a second passage that opens to the second liquid chamber at one end. The non-magnetic member has a passage, and the non-magnetic member is formed in an endd arc shape when the non-magnetic member is viewed from the axial direction, one end is connected to the other end of the first continuous passage, and the other end is the first. It has a third passage that connects to the other end of the two passages, and a magnetic viscous fluid in the first liquid chamber, the second liquid chamber, the first passage, the second passage, and the third passage. Is filled.

According to the present invention, the size of the active anti-vibration device can be reduced.

It is a perspective view of a mount bush. It is the figure which looked at the mount bush from the axial direction. It is sectional drawing of the mount bush. It is sectional drawing of the mount bush. It is sectional drawing of the inner magnetic material core and the electromagnetic coil. It is the figure which looked at the intermediate plate from the axial direction. 7A and 7B are schematic views of the ferrofluid. It is a figure which shows the magnetic flux of the magnetic field generated in the mount bush when the electromagnetic coil is energized. It is a figure which shows the magnetic flux of the magnetic field generated in the mount bush when the electromagnetic coil is energized. It is a figure which shows the magnetic flux of the magnetic field generated in the mount bush when the electromagnetic coil is energized. 11A and 11B are diagrams showing the force acting on the ferrofluid from the first inclined surface when the inner magnetic core is displaced relative to the outer magnetic core. It is sectional drawing of the mount bush. It is sectional drawing of the mount bush. It is sectional drawing of the mount bush. It is the figure which looked at the intermediate plate from the axial direction. It is sectional drawing of the mount bush. It is sectional drawing of the mount bush. It is a schematic diagram of a magnetic viscoelastic elastomer. It is a figure which shows the magnetic flux of the magnetic field generated in the mount bush when the electromagnetic coil is energized. It is a figure which shows the magnetic flux of the magnetic field generated in the mount bush when the electromagnetic coil is energized.

[First Embodiment]
FIG. 1 is a perspective view of the mount bush 10. FIG. 2 is a view of the mount bush 10 as viewed from the axial direction. The mount bush 10 corresponds to the active anti-vibration device of the present invention. The mount bush 10 is used as a subframe mount provided between a subframe and a body of an automobile, a suspension bush provided between a suspension link and a body, and the like.

FIG. 3 is a cross-sectional view of the mount bush 10 cut along the line III-III in FIG. FIG. 4 is a cross-sectional view of the mount bush 10 cut along the IV-IV line in FIG. The mount bush 10 has an inner member 12 and an outer member 14.

The inner member 12 has an inner magnetic core 16 made of a magnetic material such as iron, an electromagnetic coil 18 that generates a magnetic field when energized, and a tubular member 20 made of a non-magnetic material such as stainless steel or aluminum.

FIG. 5 is a cross-sectional perspective view of the inner magnetic core 16 and the electromagnetic coil 18. The outer shape of the inner magnetic core 16 is formed in a rotating body shape centered on the axis of the mount bush 10. The inner magnetic core 16 has a through hole 22 penetrating in the axial direction. The inner magnetic core 16 has an electromagnetic coil mounting portion 24 formed in a radial direction in the middle portion in the axial direction over the entire circumference, and the electromagnetic coil 18 is mounted on the electromagnetic coil mounting portion 24. In the present embodiment, the electromagnetic coil 18 is attached to the inner magnetic core 16, but the electromagnetic coil 18 may be attached to the outer magnetic core 34 described later.

Both ends of the inner magnetic core 16 in the axial direction are formed in a conical shape, and the area of the cross section cut in the direction orthogonal to the axial direction of the inner magnetic core 16 becomes narrower toward the axial end. The outer peripheral surface of this conical portion constitutes the first inclined surface 28.

The outer peripheral surface of the electromagnetic coil 18 is covered with a cover 30 made of a non-magnetic material such as stainless steel or aluminum. As a result, when the electromagnetic coil 18 is energized, the magnetic flux does not leak to the outside from the portion covered with the cover 30.

The tubular member 20 is formed in a cylindrical shape and has a through hole 32 penetrating in the axial direction. The tubular member 20 is attached to both sides of the inner magnetic core 16 in the axial direction, and the through hole 32 of the tubular member 20 communicates with the through hole 22 of the inner magnetic core 16.

The outer member 14 has an outer magnetic core 34 made of a magnetic material such as iron, an intermediate plate 36 made of a non-magnetic material such as stainless steel or aluminum, and an outer plate 38 made of a non-magnetic material such as stainless steel or aluminum. ing.

The outer shape of the outer magnetic core 34 is formed in a rotating body shape centered on the axis of the mount bush 10. The outer magnetic core 34 has a first magnetic member 40 and a second magnetic member 42 that is separate from the first magnetic member 40. The intermediate plate 36 is a disk-shaped member and has a through hole 44 penetrating in the axial direction. The intermediate plate 36 is arranged so as to be sandwiched in the axial direction by the first magnetic member 40 and the second magnetic member 42. The intermediate plate 36 corresponds to the non-magnetic member of the present invention.

The outer magnetic core 34 is arranged so as to surround the radial outer side of the inner magnetic core 16. The inner peripheral surface of the outer magnetic core 34 is formed along the outer peripheral surfaces of the inner magnetic core 16 and the cover 30. The outer magnetic core 34 has a second inclined surface 46 facing the first inclined surface 28 of the inner magnetic core 16. The second inclined surface 46 is formed substantially parallel to the first inclined surface 28. When the electromagnetic coil 18 is energized, the magnetic flux leaking from the first inclined surface 28 enters the outer magnetic core 34 from the second inclined surface 46.

The outer plate 38 is a disk-shaped member and has a through hole 48 penetrating in the axial direction. The outer plate 38 is attached to each of the axially both sides of the outer magnetic core 34, and the tubular member 20 penetrates the through hole 48.

A first elastic member 50 and a second elastic member 52 are provided between the inner member 12 and the outer member 14. The first elastic member 50 is provided so as to connect the inner peripheral surface of the outer plate 38 and the outer peripheral surface of the tubular member 20. The first elastic member 50 is provided over the entire circumference of the outer plate 38 and the tubular member 20. The second elastic member 52 is provided so as to connect the inner peripheral surface of the intermediate plate 36 and the outer peripheral surface of the cover 30. The second elastic member 52 is provided over the entire circumference of the outer plate 38 and the cover 30. The space between the inner peripheral surface of the outer member 14 and the outer peripheral surface of the inner member 12 is partitioned by the inner peripheral surface of the outer member 14, the outer peripheral surface of the inner member 12, the first elastic member 50, and the second elastic member 52. The first liquid chamber 54 and the second liquid chamber 56 are provided. The first liquid chamber 54 and the second liquid chamber 56 are formed to be liquid-tight. The first liquid chamber 54 and the second liquid chamber 56 are arranged so as to be axially separated from each other with the second elastic member 52 interposed therebetween.

As shown in FIG. 3, the first magnetic member 40 has a first continuous passage 58 whose one end opens into the first liquid chamber 54. As shown in FIG. 4, the second magnetic member 42 has a second passage 60 whose one end opens into the second liquid chamber 56.

FIG. 6 is a view of the intermediate plate 36 as viewed from the axial direction. As shown in FIG. 6, the intermediate plate 36 has a third passage 62 formed in an endd arc shape or a C shape when viewed from the axial direction. The third passage 62 is formed so as to penetrate the intermediate plate 36 in the axial direction. One end of the third passage 62 is connected to the other end of the first passage 58, and the other end of the third passage 62 is connected to the other end of the second passage 60. When the third passage 62 is cut in the axial direction of the outer member 14, as shown in FIG. 3, the shape of the cross section of the third passage 62 is rectangular, and the side extending in the axial direction is the long side. The side extending in the direction orthogonal to the axial direction is formed to be the short side.

The first liquid chamber 54, the second liquid chamber 56, the first passage 58, the second passage 60, and the third passage 62 are filled with the ferrofluid 64. When the inner member 12 is displaced relative to the outer member 14 in the axial direction, the ferrofluid 64 in the first liquid chamber 54 passes through the first passage 58, the second passage 60, and the third passage 62. It passes through and moves to the second liquid chamber 56. Alternatively, when the inner member 12 is displaced relative to the outer member 14 in the axial direction, the ferrofluid 64 in the second liquid chamber 56 becomes the first passage 58, the second passage 60, and the third passage. It passes through 62 and moves to the first liquid chamber 54. The first passage 58, the second passage 60, and the third passage 62 serve as orifices, and the flow resistance of the magnetic viscous fluid 64 passing through the first passage 58, the second passage 60, and the third passage 62 Become. Therefore, when energy for displaced the inner member 12 and the outer member 14 in the axial direction is input to the mount bush 10, a part of the input energy is consumed by the flow path resistance when passing through the orifice. Will be done. As a result, the mount bush 10 of the present embodiment has a vibration damping function against vibration input in the axial direction.

The magnetic viscous fluid 64 is a fluid 66 such as oil mixed with magnetic particles 68 such as iron powder. 7A and 7B are schematic views of the ferrofluid 64, FIG. 7A shows a state when a magnetic field is not applied, and FIG. 7B shows a state when a magnetic field is applied. When no magnetic field is applied, the magnetic particles 68 can move freely in the fluid 66. Therefore, the magnetic particles 68 do not obstruct the flow of the fluid 66. On the other hand, when a magnetic field is applied, the magnetic particles 68 in the fluid 66 are aligned in the fluid 66 along the direction of the magnetic flux. Therefore, the aligned magnetic particles 68 obstruct the flow of the fluid 66. As a result, the viscosity of the magnetic viscous fluid 64 when the magnetic field is applied becomes higher than the viscosity of the magnetic viscous fluid 64 when the magnetic field is not applied. As a result, the vibration damping force of the mount bush 10 can be made variable by controlling the magnitude of the current flowing through the electromagnetic coil 18 to change the viscosity of the ferrofluid fluid 64.

FIG. 8 is a diagram showing the magnetic flux of the magnetic field generated in the mount bush 10 when the electromagnetic coil 18 is energized. FIG. 9 is a diagram showing the magnetic flux of the magnetic field generated in the mount bush 10 when the electromagnetic coil 18 is energized. FIG. 9 is an enlarged view of the portion shown by IX surrounded by the alternate long and short dash line in FIG.

When the electromagnetic coil 18 is energized, a circulating magnetic field is generated between the inner magnetic core 16 and the outer magnetic core 34 as shown in FIG. An intermediate plate 36 made of a non-magnetic material is interposed between the first magnetic member 40 and the second magnetic member 42 of the outer magnetic material core 34. Since the magnetic permeability of the intermediate plate 36 is lower than the magnetic permeability of the ferrofluid 64, the magnetic flux passes through the third passage 62 as shown in FIG. The direction of the magnetic flux passing through the third passage 62 is orthogonal to the direction in which the ferrofluid 64 flows in the third passage 62. Therefore, the viscosity of the ferrofluid 64 in the third passage 62 can be changed when the electromagnetic coil 18 is energized and when the electromagnetic coil 18 is not energized.

FIG. 10 is a diagram showing the magnetic flux of the magnetic field generated in the mount bush 10 when the electromagnetic coil 18 is energized. FIG. 10 is an enlarged view of the portion indicated by X surrounded by the alternate long and short dash line in FIG. 8, and schematically shows the magnetic particles 68 in the ferrofluid 64. As shown in FIG. 10, a magnetic field flows in the ferrofluid 64 between the first inclined surface 28 of the inner magnetic core 16 and the second inclined surface 46 of the outer magnetic core 34. At this time, the direction of the magnetic flux between the first inclined surface 28 of the inner magnetic core 16 and the second inclined surface 46 of the outer magnetic core 34 is substantially relative to the first inclined surface 28 and the second inclined surface 46. The directions are orthogonal. The magnetic particles 68 in the ferrofluid 64 located between the first inclined surface 28 and the second inclined surface 46 are substantially orthogonal to the first inclined surface 28 and the second inclined surface 46 along the magnetic flux. Arranged in the direction. The magnetic viscous fluid 64 when a magnetic field is applied has high elasticity in the direction of the magnetic flux, that is, in the direction in which the magnetic particles 68 are arranged.

11A and 11B are views showing the force acting on the ferrofluid 64 from the first inclined surface 28 when the inner magnetic core 16 is displaced relative to the outer magnetic core 34. FIG. 11A shows the force acting on the ferrofluid 64 from the first inclined surface 28 when the inner magnetic core 16 is displaced axially with respect to the outer magnetic core 34. FIG. 11B shows the force acting on the ferrofluid 64 from the first inclined surface 28 when the inner magnetic core 16 is displaced with respect to the outer magnetic core 34 in the radial direction.

When the inner magnetic core 16 is displaced with respect to the outer magnetic core 34 in the axial direction, a force F1 acts on the magnetic viscous fluid 64 from the first inclined surface 28 as shown in FIG. 11A. It has a component F2 orthogonal to one inclined surface 28. Similarly, when the inner magnetic core 16 is displaced in the radial direction with respect to the outer magnetic core 34, a force G1 acts on the magnetically viscous fluid 64 from the first inclined surface 28 as shown in FIG. 11B. Has a component G2 orthogonal to the first inclined surface 28. Therefore, even when a force that relatively displaces the inner member 12 and the outer member 14 in the axial direction is input to the mount bush 10, a force that relatively displaces the inner member 12 and the outer member 14 in the radial direction is input. Even if there is, a force acts on the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 in the direction of the magnetic flux of the magnetic field. Therefore, the elasticity of the ferrofluid 64 located between the first inclined surface 28 and the second inclined surface 46 can be made variable when the electromagnetic coil 18 is energized and when it is not energized.

The greater the distance between the first inclined surface 28 and the second inclined surface 46, the smaller the magnetic force acting between the first inclined surface 28 and the second inclined surface 46. Therefore, the bonding force between the magnetic particles 68 in the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 becomes small, and the rigidity of the magnetic viscous fluid 64 becomes low. On the other hand, the smaller the distance between the first inclined surface 28 and the second inclined surface 46, the greater the magnetic force acting between the first inclined surface 28 and the second inclined surface 46. Therefore, the bonding force between the magnetic particles 68 in the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 increases, and the rigidity of the magnetic viscous fluid 64 increases. That is, when the inner magnetic core 16 is displaced with respect to the outer magnetic core 34, the rigidity of the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 changes.

When the inner magnetic core 16 is displaced with respect to the outer magnetic core 34 in the axial direction, the amount of displacement of the distance between the first inclined surface 28 and the second inclined surface 46 is smaller than the amount of axial displacement. When the inner magnetic core 16 is displaced with respect to the outer magnetic core 34 in the radial direction, the displacement amount of the distance between the first inclined surface 28 and the second inclined surface 46 with respect to the displacement amount in the radial direction is small. Therefore, it is possible to reduce the change in the rigidity of the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 when the inner magnetic core 16 is displaced with respect to the outer magnetic core 34.

[Action effect]
The mount bush 10 of the present embodiment is arranged apart from each other between the outer peripheral surface of the inner member 12 and the inner peripheral surface of the outer member 14, and is liquid-tightly formed in the first liquid chamber 54 and the second liquid chamber 54. It has a liquid chamber 56. The inner member 12 has an inner magnetic core 16 made of a magnetic material, and the outer member 14 has an outer magnetic core 34 made of a magnetic material. Further, the outer magnetic core 34 has a first magnetic member 40 and a second magnetic member 42. The first magnetic member 40 has a first passage 58 having one end opening into the first liquid chamber 54, and the second magnetic member 42 has a second passage 60 having one end opening into the second liquid chamber 56. .. The intermediate plate 36 made of a non-magnetic material sandwiched between the first magnetic member 40 and the second magnetic member 42 in the axial direction has a third passage 62. The third passage 62 is formed in an endd arc shape when the intermediate plate 36 is viewed from the axial direction, one end is connected to the other end of the first passage 58, and the other end is the second passage 60. It is connected to the other end of. The first liquid chamber 54, the second liquid chamber 56, the first passage 58, the second passage 60, and the third passage 62 are filled with the ferrofluid 64.

As a result, the vibration damping force of the mount bush 10 is changed by controlling the current flowing through the electromagnetic coil 18 to change the viscosity of the ferrofluid 64 in the third communication passage 62, so that the vibration damping characteristics can be made variable. can.

Further, since the third passage 62 serving as the orifice is formed in an arc shape around the axis of the intermediate plate 36, it is possible to suppress the increase in size of the mount bush 10 in the axial direction while ensuring the flow path resistance due to the orifice. ..

By using the mount bush 10 of the present embodiment as a subframe mount or suspension bush, it is input to the vehicle body from the subframe or suspension according to the vehicle speed, lateral acceleration, steering angle, engine speed, accelerator pedal opening, and the like. The amount of vibration cutoff can be adjusted. For example, during cruising on a highway, the current flowing through the electromagnetic coil 18 is reduced to reduce the damping force of the mount bush 10. As a result, vibration input to the vehicle body can be suppressed and comfort can be improved. Further, when traveling on a winding road, the current flowing through the electromagnetic coil 18 is increased to increase the damping force of the mount bush 10. Thereby, the turning performance of the vehicle can be improved. For example, by switching the switch by the user, it is possible to switch between a highly comfortable state and a highly maneuverable state, and it is possible to construct a vehicle having two sides. For example, in an autonomous vehicle in which the mount bush 10 of the present embodiment is used as a subframe mount or a suspension bush, the vehicle is normally set to a highly comfortable state, and is automatically set to a highly maneuverable state in an emergency such as danger avoidance. You can also switch.

Further, in the mount bush 10 of the present embodiment, the inner magnetic core 16 has a first inclined surface 28 formed so as to be inclined with respect to the axial direction on the outer peripheral surfaces of both ends in the axial direction. Further, the outer magnetic core 34 has a second inclined surface 46 formed so as to be inclined with respect to the axial direction at a position facing the first inclined surface 28 on the inner peripheral surface thereof. As a result, even when a force that causes the inner member 12 and the outer member 14 to be relatively displaced in the axial direction is input to the mount bush 10, a force that is relatively displaced in the radial direction is input. Even so, a force acts on the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 in the direction of the magnetic flux of the magnetic field. Therefore, the mount bush 10 controls the current flowing through the electromagnetic coil 18 to change the elasticity of the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46, thereby changing the elasticity of the mount bush 10. Both the stiffness with respect to the axial force and the stiffness with respect to the radial force can be changed. Therefore, both the anti-vibration characteristic for the axial force of the mount bush 10 and the anti-vibration characteristic for the force in the direction intersecting the axial direction can be made variable.

When the inner magnetic core 16 is displaced with respect to the outer magnetic core 34 in the axial direction, the amount of displacement of the distance between the first inclined surface 28 and the second inclined surface 46 is smaller than the amount of axial displacement. When the inner magnetic core 16 is displaced with respect to the outer magnetic core 34 in the radial direction, the displacement amount of the distance between the first inclined surface 28 and the second inclined surface 46 with respect to the displacement amount in the radial direction is small. Therefore, it is possible to reduce the change in the rigidity of the magnetic viscous fluid 64 located between the first inclined surface 28 and the second inclined surface 46 when the inner magnetic core 16 is displaced with respect to the outer magnetic core 34.

The mount bush 10 of the present embodiment has a rectangular cross-sectional shape when the third continuous passage 62 is cut in the axial direction of the outer member 14, and the side extending in the axial direction is the long side and is orthogonal to the axial direction. The side extending in the direction is formed to be a short side. By narrowing the width of the third passage 62 in the direction orthogonal to the axial direction, a magnetic field can be applied to the entire third passage 62 when the electromagnetic coil 18 is energized. Therefore, the amount of change in the viscosity of the ferrofluid 64 in the third passage 62 can be increased with respect to the controlled amount of the current flowing through the electromagnetic coil 18. Therefore, the amount of change in the vibration damping force of the mount bush 10 with respect to the vibration input in the axial direction can be increased, and the range of change in the vibration isolation characteristics can be increased.

[Second Embodiment]
In addition to the first liquid chamber 54 and the second liquid chamber 56 of the mount bush 10 of the first embodiment, the mount bush 10 of the present embodiment has a third liquid chamber 70 and a fourth liquid chamber 70 arranged apart from each other in the circumferential direction. It has a liquid chamber 72. Hereinafter, the configuration of the mount bush 10 of the present embodiment will be described, but the same configuration as that of the mount bush 10 of the first embodiment is designated by the same reference numerals and a part of the description is omitted.

FIG. 12 is a cross-sectional view of the mount bush 10 cut along the line XII-XII in FIG. FIG. 13 is a cross-sectional view of the mount bush 10 cut along the line XIII-XIII in FIG. FIG. 14 is a cross-sectional view of the mount bush 10 cut along the XIV-XIV line in FIG.

A first elastic member 50 and a second elastic member 52 are provided between the inner member 12 and the outer member 14. The first elastic member 50 is provided so as to connect the inner peripheral surface of the outer plate 38 and the outer peripheral surface of the tubular member 20. The first elastic member 50 is provided over the entire circumference of the outer plate 38 and the tubular member 20. The second elastic member 52 is provided so as to connect the inner peripheral surface of the intermediate plate 36 and the outer peripheral surface of the cover 30. The second elastic member 52 is provided over the entire circumference of the outer plate 38 and the cover 30.

The space between the inner peripheral surface of the outer member 14 and the outer peripheral surface of the inner member 12 is partitioned by the inner peripheral surface of the outer member 14, the outer peripheral surface of the inner member 12, the first elastic member 50, and the second elastic member 52. The first liquid chamber 54 and the second liquid chamber 56 are provided. The first liquid chamber 54 and the second liquid chamber 56 are formed to be liquid-tight. The first liquid chamber 54 and the second liquid chamber 56 are arranged so as to be axially separated from each other with the second elastic member 52 interposed therebetween.

In the space between the inner peripheral surface of the outer member 14 and the outer peripheral surface of the inner member 12, the third liquid chamber 70 and the fourth liquid chamber 72 are partitioned by the inner peripheral surface of the outer member 14 and the second elastic member 52. Is provided. The third liquid chamber 70 and the fourth liquid chamber 72 are formed to be liquid-tight. The third liquid chamber 70 and the fourth liquid chamber 72 are arranged apart from each other in the circumferential direction with the partition portion 74 of the second elastic member 52 shown in FIG. 14 interposed therebetween.

As shown in FIG. 12, the first magnetic member 40 has a first continuous passage 58 whose one end opens into the first liquid chamber 54. As shown in FIG. 13, the second magnetic member 42 has a second passage 60 whose one end opens into the second liquid chamber 56. As shown in FIG. 12, the first magnetic member 40 has a fourth passage 76 having one end opening into the third liquid chamber 70, and the second magnetic member 42 has one end opening into the fourth liquid chamber 72. It has a fifth passage 78.

FIG. 15 is a view of the intermediate plate 36 as viewed from the axial direction. As shown in FIG. 15, the intermediate plate 36 has a third passage 62 formed in an endd arc shape or a C shape when viewed from the axial direction. The third passage 62 is formed so as to penetrate the intermediate plate 36 in the axial direction. One end of the third passage 62 is connected to the other end of the first passage 58, and the other end of the third passage 62 is connected to the other end of the second passage 60.

Further, as shown in FIG. 15, the intermediate plate 36 has a sixth passage 80 formed in an endd arc shape or a C shape on the outer peripheral side of the third passage 62 when viewed from the axial direction. ing. The sixth passage 80 is formed so as to penetrate the intermediate plate 36 in the axial direction. One end of the sixth passage 80 is connected to the other end of the fourth passage 76, and the other end of the fifth passage 78 is connected to the other end of the second passage 60.

When the third passage 62 is cut in the axial direction of the outer member 14, as shown in FIG. 12, the shape of the cross section of the third passage 62 is rectangular, and the side extending in the axial direction is the long side. The side extending in the direction orthogonal to the axial direction is formed to be the short side. Similarly, when the 6th passage 80 is cut in the axial direction of the outer member 14, as shown in FIG. 12, the shape of the cross section of the 6th passage 80 is rectangular and the side extending in the axial direction is long. It is formed so that it becomes a side and the side extending in the direction orthogonal to the axial direction becomes the short side.

The first liquid chamber 54, the second liquid chamber 56, the first passage 58, the second passage 60, and the third passage 62 are filled with the ferrofluid 64. When the inner member 12 is displaced relative to the outer member 14 in the axial direction, the ferrofluid 64 in the first liquid chamber 54 passes through the first passage 58, the second passage 60, and the third passage 62. It passes through and moves to the second liquid chamber 56. Alternatively, when the inner member 12 is displaced relative to the outer member 14 in the axial direction, the ferrofluid 64 of the second liquid chamber 56 becomes the first passage 58, the second passage 60, and the third passage 62. To move to the first liquid chamber 54. The first passage 58, the second passage 60, and the third passage 62 serve as orifices, and the flow resistance of the magnetic viscous fluid 64 passing through the first passage 58, the second passage 60, and the third passage 62 Become. Therefore, the force for moving the inner member 12 relative to the outer member 14 in the mount bush 10 in the axial direction is consumed by the flow path resistance when passing through the orifice. As a result, the mount bush 10 of the present embodiment has a vibration damping function against vibration input in the axial direction.

The third liquid chamber 70, the fourth liquid chamber 72, the fourth passage 76, the fifth passage 78, and the sixth passage 80 are filled with the ferrofluid 64. When the inner member 12 is displaced relative to the outer member 14 in the radial direction, the ferrofluid 64 in the third liquid chamber 70 passes through the fourth passage 76, the fifth passage 78, and the sixth passage 80. It passes through and moves to the fourth liquid chamber 72. Alternatively, when the inner member 12 is displaced relative to the outer member 14 in the radial direction, the ferrofluid 64 in the fourth liquid chamber 72 becomes the fourth passage 76, the fifth passage 78, and the sixth passage. It passes through 80 and moves to the third liquid chamber 70. The 4th passage 76, the 5th passage 78, and the 6th passage 80 serve as orifices, and the flow resistance of the magnetic viscous fluid 64 passing through the 4th passage 76, the 5th passage 78, and the 6th passage 80 Become. Therefore, when energy for displaced the inner member 12 and the outer member 14 in the relative radial direction is input to the mount bush 10, a part of the input energy is consumed by the flow path resistance when passing through the orifice. Will be done. As a result, the mount bush 10 of the present embodiment has a vibration damping function against vibration input in the radial direction.

[Action effect]
In the mount bush 10 of the present embodiment, the outer peripheral surface of the inner member 12 and the inner peripheral surface of the outer member 14 are arranged apart from each other in the axial direction, and the first liquid chamber is formed in a liquid-tight manner. It has 54 and a second liquid chamber 56. Further, the mount bush 10 is arranged between the outer peripheral surface of the inner member 12 and the inner peripheral surface of the outer member 14 so as to be separated from each other in the circumferential direction, and the third liquid chamber 70 and the liquid-tightly formed third liquid chamber 70 and the third liquid chamber 70 are formed. It has a four-liquid chamber 72. The first magnetic member 40 has a first passage 58 having one end opening into the first liquid chamber 54 and a fourth passage 76 having one end opening into the third liquid chamber 70. The second magnetic member 42 has a second passage 60 having one end opening into the second liquid chamber 56, and a fifth passage 78 having one end opening into the fourth liquid chamber 72. Further, the intermediate plate 36 made of a non-magnetic material sandwiched between the first magnetic member 40 and the second magnetic member 42 in the axial direction has a third passage 62 and a sixth passage 80. The third passage 62 and the sixth passage 80 are formed in an endd arc shape when the intermediate plate 36 is viewed from the axial direction. One end of the third passage 62 is connected to the other end of the first passage 58, and the other end of the third passage 62 is connected to the other end of the second passage 60. One end of the sixth passage 80 is connected to the other end of the fourth passage 76, and the other end of the sixth passage 80 is connected to the other end of the fifth passage 78. The first liquid chamber 54, the second liquid chamber 56, the first passage 58, the second passage 60 and the third passage 62, and the third liquid chamber 70, the fourth liquid chamber 72, the fourth passage 76, The fifth passage 78 and the sixth passage 80 are filled with the ferrofluid 64.

As a result, the mount bush 10 can have a vibration damping function for vibration input in the axial direction and also have a vibration damping function for vibration input in the radial direction.

The mount bush 10 of the present embodiment has a rectangular cross-sectional shape when the sixth passage 80 is cut in the axial direction of the outer member 14, and the side extending in the axial direction is the long side and is orthogonal to the axial direction. The side extending in the direction is formed to be a short side. By narrowing the width of the sixth passage 80 in the direction orthogonal to the axial direction, a magnetic field can be applied to the entire sixth passage 80 when the electromagnetic coil 18 is energized. Therefore, the amount of change in the viscosity of the ferrofluid 64 in the sixth passage 80 can be increased with respect to the controlled amount of the current flowing through the electromagnetic coil 18. Therefore, the amount of change in the vibration damping force of the mount bush 10 with respect to the vibration input in the radial direction can be increased, and the range of change in the vibration isolation characteristics can be increased.

[Third Embodiment]
In the mount bush 10 of the present embodiment, in addition to the first elastic member 50 and the second elastic member 52 of the mount bush 10 of the first embodiment, the magnetic viscoelastic elastomer 82 is provided between the inner member 12 and the outer member 14. Is provided. Hereinafter, the configuration of the mount bush 10 of the present embodiment will be described, but the same configuration as that of the mount bush 10 of the first embodiment is designated by the same reference numerals and a part of the description is omitted.

FIG. 16 is a cross-sectional view of the mount bush 10 cut along the XVI-XVI line in FIG. FIG. 17 is a cross-sectional view of the mount bush 10 cut along the line XVII-XVII in FIG.

The magnetic viscoelastic elastomer 82 is provided so as to connect the first inclined surface 28 of the inner magnetic core 16 and the second inclined surface 46 of the outer magnetic core 34. The magnetic viscoelastic elastomer 82 is provided in a part of the inner magnetic material core 16 and the outer magnetic material core 34 in the circumferential direction.

The magnetic viscoelastic elastomer 82 is a magnetic rubber in which magnetic particles 84 such as iron powder are mixed inside a base made of natural rubber, silicon rubber, or the like. FIG. 18 is a schematic view of the magnetic viscoelastic elastomer 82. The magnetic viscoelastic elastomer 82 has higher elasticity when a magnetic field is applied than when a magnetic field is not applied. The magnetic viscoelastic elastoma 82 causes a large change in elasticity between when a magnetic field is applied and when it is not applied, particularly with respect to a shearing force that deforms the magnetic viscoelastic elastoma 82 in a direction intersecting the direction of the magnetic flux of the magnetic field. Can be done. Further, the magnetic viscoelastic elastoma 82 can further increase the change in elasticity when the magnetic field is applied and when the magnetic field is not applied by arranging the magnetic particles 84 along the direction of the magnetic flux of the magnetic field. As a result, the rigidity of the mount bush 10 can be changed and the vibration isolation characteristics can be made variable by controlling the current flowing through the electromagnetic coil 18 and changing the elasticity of the magnetic viscoelastic elastomer 82.

FIG. 19 is a diagram showing the magnetic flux of the magnetic field generated in the mount bush 10 when the electromagnetic coil 18 is energized. FIG. 20 is a diagram showing the magnetic flux of the magnetic field generated in the mount bush 10 when the electromagnetic coil 18 is energized. FIG. 20 is an enlarged view of the portion indicated by XX surrounded by the alternate long and short dash line in FIG. 19, and schematically shows the magnetic particles 84 in the magnetic viscoelastic elastomer 82.

When the electromagnetic coil 18 is energized, a magnetic field flows inside the inner magnetic core 16 and the outer magnetic core 34 as shown in FIG. A magnetic field flows in the magnetic viscoelastic elastomer 82 between the first inclined surface 28 of the inner magnetic core 16 and the second inclined surface 46 of the outer magnetic core 34. As shown in FIG. 20, the magnetic particles 84 in the magnetic viscoelastic elastomer 82 are arranged along the direction of the magnetic flux line of the magnetic field flowing between the first inclined surface 28 and the second inclined surface 46 when the electromagnetic coil 18 is energized. It is arranged. In other words, the magnetic particles 84 in the magnetic viscoelastic elastomer 82 are arranged so as to be inclined with respect to the axial direction of the mount bush 10, as shown in FIG. Alternatively, as shown in FIG. 20, the magnetic particles 84 in the magnetic viscoelastic elastomer 82 can be said to be arranged in a direction substantially orthogonal to the first inclined surface 28 and the second inclined surface 46.

[Action effect]
The mount bush 10 of the present embodiment has a magnetic viscoelastic elastomer 82 between the outer peripheral surface of the inner magnetic core 16 and the inner peripheral surface of the outer magnetic core 34. As a result, the rigidity of the mount bush 10 can be changed and the vibration isolation characteristics can be made variable by controlling the current flowing through the electromagnetic coil 18 to change the elasticity of the magnetic viscoelastic elastomer 82.

[Technical Thought Obtained from the Embodiment]
The technical ideas that can be grasped from the above embodiments are described below.

An inner member (12) having an inner magnetic core (16) extending in the axial direction and an inner member (12) extending coaxially with the inner member so as to surround the radial outer peripheral portion of the inner magnetic core. An outer member (14) having an arranged outer magnetic core (34), an electromagnetic coil (18) provided on one of the inner magnetic core and the outer magnetic core to generate a magnetic field, and the inner member. Actively having a first liquid chamber (54) and a second liquid chamber (56) formed in a liquid-tight manner while being arranged apart from each other between the outer peripheral surface of the outer member and the inner peripheral surface of the outer member. In the mold anti-vibration device (10), the outer magnetic core has a first magnetic member (40) and a second magnetic member (42) separate from the first magnetic member. The first magnetic member has a non-magnetic member (36) arranged so as to be axially sandwiched between the first magnetic member and the second magnetic member, and one end of the first magnetic member opens into the first liquid chamber. The second magnetic member has a single passage (58), the second magnetic member has a second passage (60) at which one end opens into the second liquid chamber, and the non-magnetic member has the non-magnetic member as an axis. A third passage (62) formed in an arcuate shape when viewed from the direction, one end of which is connected to the other end of the first passage and the other end of which is connected to the other end of the second passage. The first liquid chamber, the second liquid chamber, the first passage, the second passage, and the third passage are filled with the magnetic viscous fluid (64).

In the active vibration isolator, the inner magnetic core has a first inclined surface (28) formed on the outer peripheral surfaces of both ends in the axial direction so as to be inclined with respect to the axial direction. The outer magnetic core may have a second inclined surface (46) formed so as to be inclined with respect to the axial direction at a position of the inner peripheral surface facing the first inclined surface.

In the active type anti-vibration device, the shape of the cross section when the third continuous passage is cut in the axial direction of the outer member is rectangular, and the side extending in the axial direction of the outer member is a long side. , The side extending in the direction orthogonal to the axial direction may be a short side.

In the active anti-vibration device, the first liquid chamber and the second liquid chamber are arranged so as to be axially separated from each other, and the outer peripheral surface of the inner member and the inner peripheral surface of the outer member are arranged. The first magnetic member has a third liquid chamber (70) and a fourth liquid chamber (72) which are arranged apart from each other in the circumferential direction and are formed in a liquid-tight manner, and one end of the first magnetic member is said to be the first. The second magnetic member has a fifth passage (78) at one end that opens into the fourth liquid chamber, and the non-magnetic member has a fourth passage (76) that opens into the third liquid chamber. The non-magnetic member is formed in an arcuate shape when viewed from the axial direction, one end of which is connected to the other end of the fourth passage, and the other end of which is connected to the other end of the fifth passage. It has 6 passages (80), and the third liquid chamber, the fourth liquid chamber, the fourth passage, the fifth passage and the sixth passage may be filled with a magnetic viscous fluid. ..

In the active vibration isolator, the shape of the cross section when the sixth passage is cut in the axial direction of the outer member is rectangular, and the side extending in the axial direction of the outer member is a long side. , The side extending in the direction orthogonal to the axial direction may be a short side.

The active anti-vibration device may have a magnetic viscoelastic elastomer (82) provided between the outer peripheral surface of the inner magnetic core and the inner peripheral surface of the outer magnetic core.

10 ... Mount bush (active vibration isolator) 12 ... Inner member 14 ... Outer member 16 ... Inner magnetic core 18 ... Electromagnetic coil 28 ... First inclined surface 34 ... Outer magnetic core 36 ... Intermediate plate (non-magnetic member)
40 ... 1st magnetic member 42 ... 2nd magnetic member 46 ... 2nd inclined surface 54 ... 1st liquid chamber 56 ... 2nd liquid chamber 58 ... 1st continuous passage 60 ... 2nd continuous passage 62 ... 3rd continuous passage 64 ... Magnetic viscous fluid 70 ... 3rd liquid chamber 72 ... 4th liquid chamber 76 ... 4th passage 78 ... 5th passage 80 ... 6th passage 82 ... Magnetic viscoelastic elastoma

Claims (6)

An inner member having an inner magnetic core formed extending in the axial direction,
An outer member having an outer magnetic core formed so as to extend coaxially with the inner member and arranged so as to surround a radial outer peripheral portion of the inner magnetic core.
An electromagnetic coil provided on one of the inner magnetic core and the outer magnetic core to generate a magnetic field,
The first liquid chamber and the second liquid chamber, which are arranged apart from each other between the outer peripheral surface of the inner member and the inner peripheral surface of the outer member and are liquid-tightly formed,
It is an active type anti-vibration device that has
The outer magnetic core has a first magnetic member and a second magnetic member separate from the first magnetic member.
It has a non-magnetic member arranged so as to be axially sandwiched between the first magnetic member and the second magnetic member.
The first magnetic member has a first continuous passage, one end of which opens into the first liquid chamber.
The second magnetic member has a second passage at one end that opens into the second liquid chamber.
The non-magnetic member is formed in an endd arc shape when the non-magnetic member is viewed from the axial direction, one end is connected to the other end of the first passage, and the other end is the other of the second passage. It has a third passage that connects to the end,
An active vibration isolator in which a magnetically viscous fluid is filled in the first liquid chamber, the second liquid chamber, the first passage, the second passage, and the third passage. The active anti-vibration device according to claim 1.
The inner magnetic core has a first inclined surface formed so as to be inclined with respect to the axial direction on the outer peripheral surfaces of both ends in the axial direction.
The outer magnetic core is an active anti-vibration device having a second inclined surface formed so as to be inclined in the axial direction at a position of the inner peripheral surface facing the first inclined surface. The active anti-vibration device according to claim 1 or 2.
The shape of the cross section when the third passage is cut in the axial direction of the outer member is rectangular, the side extending in the axial direction of the outer member is the long side, and the side extending in the direction orthogonal to the axial direction is defined as the long side. An active anti-vibration device with a short side. The active anti-vibration device according to any one of claims 1 to 3.
The first liquid chamber and the second liquid chamber are arranged so as to be axially separated from each other.
It has a third liquid chamber and a fourth liquid chamber that are arranged apart from each other in the circumferential direction between the outer peripheral surface of the inner member and the inner peripheral surface of the outer member and are liquid-tightly formed.
The first magnetic member has a fourth passage, one end of which opens into the third liquid chamber.
The second magnetic member has a fifth passage, one end of which opens into the fourth liquid chamber.
The non-magnetic member is formed in an endd arc shape when the non-magnetic member is viewed from the axial direction, one end is connected to the other end of the fourth passage, and the other end is the other of the fifth passage. It has a 6th passage that connects to the end,
An active vibration isolator in which the third liquid chamber, the fourth liquid chamber, the fourth passage, the fifth passage, and the sixth passage are filled with the ferrofluid. The active anti-vibration device according to claim 4.
The shape of the cross section when the sixth passage is cut in the axial direction of the outer member is rectangular, the side extending in the axial direction of the outer member is the long side, and the side extending in the direction orthogonal to the axial direction is defined as the long side. An active anti-vibration device with a short side. The active anti-vibration device according to any one of claims 1 to 5.
An active anti-vibration device having a magnetic viscoelastic elastomer provided between an outer peripheral surface of the inner magnetic core and an inner peripheral surface of the outer magnetic core.

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