JP2023061172A - Magnetic viscosity fluid device - Google Patents

Abstract

To provide a magnetic viscosity fluid device which can apply a magnetic field to a magnetic viscous fluid efficiently while preventing a magnetic path which causes a short circuit in a radial direction from being formed from an outer periphery part of the rotary plate.SOLUTION: A magnetic viscosity fluid device 1 includes: a rotary plate 20; a first yoke 30 which faces the rotary plate through a first gap S1; a second yoke 40 which faces the rotary plate through a second gap S2; a magnetic viscous fluid 50 disposed between the first gap and the second gap; and a coil 60. The first yoke and the second yoke have a magnetic flux delivery part 70. The first yoke has: a first yoke base part 31; and a first yoke first extending part 32. The second yoke has: a second yoke base part 41; and a second yoke extending part 42 which extends from the second yoke base part and forms the magnetic flux delivery part with the first yoke first extending part. A short circuit magnetic path prevention member 80 formed of a non-magnetic material is disposed between an outer periphery part of the rotary plate 20 and an inner peripheral surface 42i of the second yoke extending part.SELECTED DRAWING: Figure 1

Description

The present invention is a magneto-rheological fluid that can change the torque transmitted between the members by interposing a magneto-rheological fluid between members that are relatively rotatable and changing the strength of the magnetic field applied to the magneto-rheological fluid. It relates to viscous fluid devices.

Various magneto-rheological fluid devices have been proposed. For example, a magneto-rheological fluid device (100B) disclosed in FIG. 3 of Patent Document 1 includes a rotating plate (2B) fixed to a rotating shaft (1B) that rotates around an axis (N), and a rotating plate (2B) ) and a first yoke (3C) having opposing surfaces (37A, 37B) opposed to one main surface (2a) of the rotating plate (2B) with a gap therebetween, and a gap 61 in the other main surface (2b) of the rotating plate (2B). A second yoke (3B) having opposing surfaces (36) facing each other through a magneto-rheological fluid (6) interposed between the two gaps, so as to form a magnetic flux in the first yoke (3C) when energized. A coil (4) provided in an annular recess of the first yoke (3C).

In the magneto-rheological fluid device (100B) disclosed in Patent Document 1, the recess of the first yoke (3C) is configured so that the annular coil (4) can be loaded into the recess of the first yoke (3C). It is open on the rotating plate (2B) side in the direction of the axis (N).

JP 2014-181778 A

The inventors of the present application have proposed a first yoke 30H in which the opening of the concave portion of the first yoke in which the coil is loaded faces radially outward as shown in FIG. The magneto-rheological fluid device 1H provided is also being researched and developed. According to this magneto-rheological fluid device 1H, compared with the conventional magneto-rheological fluid device (100B), the facing area between the first yoke 30H and the rotor plate 20 can be increased. The rotation resistance of the rotor plate 20 per predetermined current value can be efficiently increased.

A first yoke 30H of a magneto-rheological fluid device 1H shown in FIG. 11 has a first tube 31H and two annular plates 32H and 33H fixed to the outer peripheral portions of the first tube 31H on both sides in the direction of the axis N. . The two annular plates 32H and 33H are fastened to the first tube 31H with bolts or the like (not shown). In the first yoke 30H, the first cylinder 31H and the two annular plates 32H and 33H form a recess 30Hd that opens radially outward. The first yoke 30H accommodates an annular coil 60H in the recess 30Hd.

The magneto-rheological fluid device 1H further includes a second yoke 40H. The second yoke 40H includes a disk 41H arranged below the rotating plate 20 and a second tube 42H fixed to the outer peripheral portion of the disk 41. As shown in FIG. The second cylinder 42H is fastened to the disk 41H with bolts B2.

As shown in FIG. 11, in the magneto-rheological fluid device 1H, the rotating plate 20 and the magneto-rheological fluid 50 are arranged in a space surrounded by the first tube 31H, the annular plate 33H, the disk 41H, and the second tube 42H. are housed in Only the magneto-rheological fluid 50 is interposed between the outer peripheral portion of the rotating plate 20 and the inner peripheral surface 42Hi of the second tube 42H, and the outer peripheral portion of the rotating plate 20 is short-circuited to the second tube 42H in the radial direction. A magnetic path (a magnetic path indicated by a dashed line Ra with an arrow in FIG. 11) may be formed. When a magnetic path short-circuiting in the radial direction from the outer peripheral portion of the rotor plate 20 to the second cylinder 42H is formed, the magnetic field intervening in the gap (second gap S2) between the rotor plate 20 and the disk 41H of the second yoke 40H is generated. There is a problem that a magnetic field cannot be applied efficiently to the viscous fluid 50 .

The present invention has been devised in view of the above problems, and prevents the formation of a short-circuited magnetic path in the radial direction from the outer periphery of the rotor plate, thereby efficiently applying a magnetic field to the magneto-rheological fluid. It is an object of the present invention to provide a magneto-rheological fluid device that can be applied.

A magneto-rheological fluid device according to a first aspect of the present invention comprises: a rotating plate fixed to a rotating shaft that rotates about an axis; a first yoke having a surface, a second yoke having a second facing surface facing the other main surface of the rotating plate with a second gap therebetween, and magneto-rheological properties interposed between the first gap and the second gap. A fluid and a coil disposed around the first yoke to create a magnetic flux in the first yoke when energized. The first yoke and the second yoke have a magnetic flux transfer section that transfers magnetic flux to each other. In this magneto-rheological fluid device, when current flows through the coil, the first yoke, the magneto-rheological fluid interposed in the first gap, the rotating plate, the magneto-rheological fluid interposed in the second gap, and the A magnetic path passing through the second yoke is formed, and a magnetic field is applied to the magneto-rheological fluid interposed between the first gap and the second gap. The first yoke is arranged such that the coil is interposed between the rotating plate and a first yoke base having a peripheral surface in which the axis passes through and the coil is arranged around the first yoke. a first yoke first extension extending radially outward from the first yoke base. The second yoke includes a second yoke base portion including the second facing surface and arranged on the other main surface side of the rotor plate, and a rotor plate extending from the second yoke base portion in the axial direction. and a second yoke extension that passes through the outside of the first yoke and forms the magnetic flux transfer section with the first yoke first extension. A short-circuit magnetic path preventing member made of a non-magnetic material is interposed between the outer peripheral portion of the rotating plate and the inner peripheral surface of the second yoke extension portion.

According to the magneto-rheological fluid device having such a configuration, since the short-circuit magnetic path prevention member made of a non-magnetic material is interposed between the outer peripheral portion of the rotor plate and the inner peripheral surface of the second yoke extension, A magnetic path short-circuited in the radial direction is prevented from being formed between the outer peripheral portion and the inner peripheral surface of the second yoke extending portion, and a magnetic field is efficiently applied to the magneto-rheological fluid interposed in the second gap. be able to.

A magneto-rheological fluid device according to a second aspect of the present invention is the magneto-rheological fluid device according to the first aspect, wherein the first yoke extends from the first yoke base to between the rotor plate and the coil. A first yoke second extension extending radially outward through the first yoke second extension is provided, and the short-circuit magnetic path prevention member is provided between the rotating plate and the outer peripheral portions of the first yoke second extension and the second extension. It is interposed between the inner peripheral surface of the yoke extending portion.

A magneto-rheological fluid device according to a third aspect of the present invention is the magneto-rheological fluid device according to the first aspect or the magneto-rheological fluid device according to the second aspect, wherein the short-circuit preventing member It abuts on the second yoke base.

A magneto-rheological fluid device according to a fourth aspect of the present invention is the magneto-rheological fluid device according to the first aspect or the magneto-rheological fluid device according to the second aspect, wherein the short-circuit magnetic path preventing member is the second yoke. Interposed between the inner peripheral surface of the extending portion and the coil and between the inner peripheral surface of the second yoke extending portion and the rotating plate, the first yoke first extending portion and the second It is configured such that the dimension of the gap between the first opposing surface and the second opposing surface is defined by being sandwiched between the yoke base and the axial direction without any gap.

According to the present invention, it is possible to provide a magneto-rheological fluid device capable of efficiently applying a magnetic field to a magneto-rheological fluid by preventing the formation of a radially short-circuited magnetic path from the outer peripheral portion of the rotor plate. can be done.

1 is a cross-sectional view showing a magneto-rheological fluid device according to a first embodiment of the present invention; FIG. FIG. 3 is a cross-sectional view showing a first yoke of the magneto-rheological fluid device according to the first embodiment of the present invention; 4 is a cross-sectional view showing a second yoke of the magneto-rheological fluid device according to the first embodiment of the present invention; FIG. Assuming that no short-circuit magnetic path prevention member is provided in the magneto-rheological fluid device according to the first embodiment of the present invention, the magnetic path short-circuits near the outer periphery of the rotating plate and the first yoke second extension. 2 is a partially enlarged cross-sectional view showing an example of . FIG. 5 is a cross-sectional view showing a magneto-rheological fluid device according to a second embodiment of the present invention; FIG. 5 is a cross-sectional view showing a magneto-rheological fluid device according to a third embodiment of the present invention; FIG. 5 is a cross-sectional view showing a magneto-rheological fluid device according to a fourth embodiment of the present invention; FIG. 11 is a cross-sectional view showing a magneto-rheological fluid device according to a fifth embodiment of the present invention; FIG. 11 is a cross-sectional view showing a magneto-rheological fluid device according to a sixth embodiment of the present invention; FIG. 11 is a cross-sectional view showing a magneto-rheological fluid device according to a seventh embodiment of the present invention; 1 is a sectional view showing a magneto-rheological fluid device developed by the inventors of the present invention; FIG.

A magneto-rheological fluid device according to a first embodiment of the present invention will be described below with reference to the drawings. In this specification, "axis N" means the axis N of the rotating shaft 10, "radial direction" means the radial direction of the rotating shaft 10, and "downward" means one of the directions of the axis N. and "above" means the other side of the axis N direction. Of course, the state of use of the magneto-rheological fluid device is not limited to the state in which the axis N of the rotating shaft 10 is oriented in the vertical direction of the real space. Also, a dashed line with an arrow indicated by symbol P in the drawing illustrates a magnetic path.

<First embodiment>
As shown in FIG. 1, the magneto-rheological fluid device 1 according to the present embodiment includes a rotating portion 5, a first yoke 30, a second yoke 40, a magneto-rheological fluid 50, a coil 60, and a short-circuit magnetic path preventing member 80. there is

The rotating part 5 has a rotating shaft 10 and a rotating plate 20 . The rotating portion 5 is rotatable about the axis N of the rotating shaft 10 with respect to the first yoke 30 and the second yoke 40 .

The rotary shaft 10 is rotatably supported around the axis N through a bearing 130 in a shaft hole 31h formed in the first yoke 30 . The rotary shaft 10 has a medium diameter portion 12 fitted into the inner diameter side of the bearing 130 , a small diameter portion 11 connected to the lower side of the medium diameter portion 12 , and a large diameter portion 13 connected to the lower side of the small diameter portion 11 . , have The small-diameter portion 11 is provided with a first enlarged-diameter protrusion 14 located below the bearing 130 and expanding in the radial direction. A second enlarged diameter projection 15 that expands in the radial direction is provided at a position below the first enlarged diameter projection 14 and at an intermediate position in the direction of the axis N of the small diameter portion 11 . The material of the rotating shaft 10 is desirably a non-magnetic material. Bearing 130 may be a rolling bearing or a sliding bearing.

The rotating plate 20 is a circular disk in this embodiment. The rotating plate 20 is fixed to the lower end surface of the large diameter portion 13 of the rotating shaft 10 that rotates around the axis N, and rotates together with the rotating shaft 10 . The rotating plate 20 has a first main surface 21 positioned on the upper side and a second main surface 22 positioned on the lower side. Rotating plate 20 is desirably made of a magnetic material.

In this embodiment, the first yoke 30 and the second yoke 40 function as one yoke through which the magnetic path formed around the coil 60 indicated by the arrowed dashed line P is passed, and the casing of the magneto-rheological fluid device 1 . also functions as The first yoke 30 and the second yoke 40 are fastened together with a bolt B1. The first yoke 30 and the second yoke 40 are each constructed using a magnetic material. The first yoke 30 and the second yoke 40 contain a space for accommodating the coil 60, a space for accommodating the bearing 130 and the rotary shaft 10, a rotatable rotary plate 20, and a magneto-rheological fluid 50. A space is formed. The first yoke 30 , the second yoke 40 , and the rotor plate 20 of the rotor 5 transmit torque to each other via the magneto-rheological fluid 50 .

The first yoke 30, as shown in FIGS. 1 and 2, is arranged above the rotating plate 20 and has an annular recess 30d for accommodating the coil 60. As shown in FIG. The recess 30d opens radially outward. A shaft hole 31 h formed in the first yoke 30 is inserted with the rotating shaft 10 . The first yoke 30 has a first opposing surface 34 that faces the first main surface 21 of the rotor plate 20 with a first gap S1 interposed therebetween. In addition, in the present embodiment, the first yoke 30 is formed in a substantially annular shape centering on the axis N. As shown in FIG.

The first yoke 30 includes a first yoke base portion 31 extending in the direction of the axis N and a first yoke first extension extending radially outward from an upper portion (one portion in the axial direction) of the first yoke base portion 31 . and a first yoke second extending portion 33 extending radially outward from the lower portion (the other portion in the axial direction) of the first yoke base portion 31 .

In the first yoke 30, the first yoke base portion 31, the first yoke first extension portion 32, and the first yoke second extension portion 33 form the recess 30d. Hereinafter, the space inside the recess 30d will be referred to as a "coil housing space".

The first yoke base portion 31 has a substantially cylindrical shape, and accommodates the bearing 130 and the rotating shaft 10 in a radially inner space. The axis N passes through the inside of the first yoke base portion 31 . The diameter of the lower portion of the inner peripheral surface of the first yoke base portion 31 is set to be slightly larger than the diameter of the large diameter portion 13 of the rotary shaft 10 . The diameter of the upper portion of the inner peripheral surface of the first yoke base portion 31 is formed larger than the diameter of the lower portion. A bearing 130 is fitted in the upper portion of the inner peripheral surface of the first yoke base portion 31 .

The lower surface of the first yoke base portion 31 forms part of a first opposing surface 34 that faces the first main surface 21 of the rotary plate 20 via the first gap S1.

A shaft seal member 90 is provided between the first yoke base portion 31 and the small diameter portion 11 of the rotary shaft 10 . The shaft seal member 90 seals between the first yoke base 31 and the rotating shaft 10 so that the magneto-rheological fluid 50, which will be described later, does not leak upward. For example, an O-ring or Y-packing is used for the shaft seal member 90 . Two shaft seal members 90 are arranged vertically, and the upper shaft seal member 90 is arranged between the first enlarged diameter projection 14 and the second enlarged diameter projection 15 of the rotating shaft 10 . . The lower shaft seal member 90 is arranged between the second enlarged diameter protrusion 15 and the large diameter portion 13 of the rotary shaft 10 .

The first yoke base 31 has a peripheral surface 31c that is a radially outer surface. A coil 60 having a shape that encircles the axis N is arranged around the peripheral surface 31c. A coil conducting wire is wound around the peripheral surface 31c. The radial center of the peripheral surface 31c coincides with the axis N. As shown in FIG.

It is desirable that an insulating coating ic is formed on the peripheral surface 31 c to prevent the current flowing through the coil 60 from leaking to the first yoke base 31 . That is, it is desirable that the first yoke 30 has an insulating coating formed on the portion around which the coil conductive wire is wound. The insulating coating ic is configured using, for example, epoxy resin or silicone resin.

The first yoke first extending portion 32 extends radially outward from the first yoke base portion 31 so that the coil 60 is interposed between it and the rotating plate 20 positioned below. In the present embodiment, the first yoke first extending portion 32 extends like a flange with respect to the upper portion of the first yoke base portion 31 . In this embodiment, the outer diameter of the first yoke first extension portion 32 is larger than the outer diameter of the coil 60 and the outer diameter of the rotating plate 20 in order to provide a short-circuit magnetic path prevention member 80 to be described later.

The first yoke second extension 33 extends radially outward from the first yoke base 31 between the rotor plate 20 and the coil 60 . In the present embodiment, the first yoke second extending portion 33 extends like a flange with respect to the lower portion of the first yoke base portion 31 . In the present embodiment, since a short-circuit magnetic path preventing member 80, which will be described later, is provided, the outer diameter of the first yoke second extending portion 33 is larger than the outer diameter of the rotating plate 20, and the first yoke first extending portion It is smaller than the outer diameter of the portion 32 .

The lower surface of the first yoke second extending portion 33 forms, together with the lower surface of the first yoke base portion 31, a first opposing surface 34 that faces the first main surface 21 of the rotary plate 20 via the first gap S1. .

The first yoke base portion 31 and the first yoke first extension portion 32 are integrally formed without interposing a dividing surface. Similarly, the first yoke base portion 31 and the first yoke second extension portion 33 are also integrally formed without interposing a dividing surface. That is, the first yoke 30 consists of one member that does not have a dividing surface. As a result, a magnetic path passing through the first yoke 30 is efficiently formed without causing magnetic resistance due to the division surface within the first yoke 30 .

As shown in FIGS. 1 and 3, the second yoke 40 is provided so that the rotating plate 20 is interposed between it and the first yoke, and a part thereof extends upward to form the coil accommodation space of the first yoke 30 . It covers the opening of (recess 30d). The second yoke 40 has a second opposing surface 44 that faces the second main surface 22 of the rotor plate 20 with a second gap S2 therebetween.

The second yoke 40 includes a disk-shaped second yoke base portion 41 that extends in a direction orthogonal to the axis line N centered on the axis line N, and a coil side (upper side) in the direction of the axis line N from the radially outer portion of the second yoke base portion 41 . and a second yoke extension 42 extending into the . The second yoke 40 has a bottomed cylindrical shape with a second yoke base portion 41 as a bottom portion and a second yoke extension portion 42 as a cylinder wall. The diameter of the second yoke base portion 41 is set to be larger than the outer diameter of the first yoke first extension portion 32 .

A hole 41 h is formed in the central portion of the second yoke base portion 41 . A piston 110 is fitted into the hole 41h so as to be movable within a predetermined range in the axis N direction. The piston 110 suppresses pressure fluctuations in the space containing the magnetorheological fluid 50 by moving according to the pressure in the space containing the magnetorheological fluid 50 . This prevents the magneto-rheological fluid 50 from leaking from the sealing portion between the rotary shaft 10 and the shaft hole 31h due to a large increase in internal pressure. An O-ring 120 is attached to the piston 110 to prevent the magneto-rheological fluid from leaking from the hole 41h.

The second yoke extension portion 42 extends from the outer peripheral portion of the second yoke base portion 41 in the direction of the axis N, passes through the radially outer side of the rotor plate 20 and the outer side of the coil 60, and extends from the first yoke first extension portion. It extends to the outside of the portion 32 . The second yoke extension 42 has a cylindrical shape centered on the axis N, and is arranged concentrically with the first yoke base 31 and the coil 60 . The upper end portion of the second yoke extending portion 42 and the first yoke first extending portion 32 are fastened together by bolts B1.

The inner peripheral surface of the upper end of the second yoke extending portion 42 and the outer peripheral surface of the first yoke first extending portion 32 are magnetic flux transfer portions that are close to or in contact with each other so that the magnetic flux is transferred to each other. 70 is formed.

The second yoke base portion 41 and the second yoke extension portion 42 are integrally formed without interposing a dividing surface. That is, the second yoke 40 consists of one member that does not have a dividing surface. As a result, a magnetic path passing through the second yoke 40 is efficiently formed without causing magnetic resistance due to the division surface within the second yoke 40 .

The magneto-rheological fluid 50 is housed in the magneto-rheological fluid 50 housing spaces in the first yoke 30 and the second yoke 40 . The accommodation space for the magneto-rheological fluid 50 is the space formed between the first facing surface 34 of the first yoke 30 and the second facing surface 44 of the second yoke 40, and in FIG. is. The magneto-rheological fluid 50 is interposed between the first gap S1 between the rotor plate 20 and the first yoke 30 and the second gap S2 between the rotor plate 20 and the second yoke 40, and the viscosity of the fluid between them is adjusted according to the viscosity. It transmits torque. In order to position the rotor plate 20 in the direction of the axis N in the space containing the magneto-rheological fluid 50, in other words, to define the gap dimension of the second gap S2, the second main gap of the rotor plate 20 is required. A gap defining plate member 100 is arranged between the surface 22 and the second opposing surface 44 of the second yoke 40 . The gap regulating plate member 100 is made of a plate member having a circular hole, and a part of the rotating shaft 10 is inserted through the circular hole so as to be relatively rotatable. The outer peripheral shape of the gap defining plate member 100 is not particularly limited, and may be circular or polygonal.

The magneto-rheological fluid 50 is a liquid in which magnetic particles are dispersed in a dispersion medium, and in particular, the magnetic particles can be nano-sized metal particles (metal nanoparticles). The magnetic particles are made of a magnetizable metal material, and the metal material is not particularly limited, but a soft magnetic material is preferred. Soft magnetic materials include, for example, iron, cobalt, nickel, and alloys such as permalloy. The dispersion medium is not particularly limited, but hydrophobic silicone oil can be mentioned as an example. The amount of magnetic particles in the magneto-rheological fluid may be, for example, 3 to 40 vol %. Various additives can also be added to the magneto-rheological fluid to obtain various desired properties.

The coil 60 is provided around the first yoke 30 so as to form magnetic flux in the first yoke 30 when energized. In this embodiment, the coil 60 is formed by directly winding a coil conductive wire around the peripheral surface 31c of the first yoke base 31 without using a member such as a bobbin. A current is supplied to the coil 60 from an external current supply device through a power supply line (not shown). The current supply device can control the current value supplied to the coil 60 . When a current flows through the coil 60, along the direction indicated by the dashed line P with an arrow in FIG. A magnetic path passing through the magneto-rheological fluid 50, the second yoke 40 and the magnetic flux transfer section 70 is formed. A magnetic field corresponding to the current value applied to the coil 60 is applied to the magneto-rheological fluid 50 interposed between the first gap S1 and the second gap S2.

When a magnetic field is applied to the magneto-rheological fluid 50 interposed between the first gap S1 and the second gap S2, viscosity (shear stress) is developed in the magneto-rheological fluid 50 according to the strength of the magnetic field. As a result, torque is transmitted between the rotating portion 5 and the first yoke 30 and the second yoke 40 according to the magnitude of the current value applied to the coil 60 .

The short-circuit magnetic path prevention member 80, as indicated by the dashed line P with an arrow in FIG. The magnetic path that passes through the rotor plate 20 in the plate thickness direction and is directed to the second yoke base 41 passes through the first gap S1 and the second gap S2, as indicated by dashed lines R1, R2, and R3 with arrows in FIG. A short circuit to the second yoke extension part 42 is prevented without penetrating or penetrating only the second gap S2.

The short-circuit magnetic path prevention member 80 is made of a non-magnetic material and has a magnetic permeability lower than that of the magneto-rheological fluid 50 . Examples of the short-circuit magnetic path prevention member 80 include austenitic stainless steel such as SUS304 and SUS316, as well as copper, aluminum, titanium, resin, brass, ceramic, and glass. The magnetic permeability of austenitic stainless steel is 1.260×10 ⁻⁶ to 8.8×10 ⁻⁶ [N/A ² ], and the relative magnetic permeability of austenitic stainless steel to vacuum is 1.0026 to 7. . The magnetic permeability of aluminum is 1.256665×10 ⁻⁶ [N/A ² ], and the relative magnetic permeability of aluminum to a vacuum is 1.000022. The magnetic permeability of the resin is 1.2567×10 ⁻⁶ [N/A ² ], and the relative magnetic permeability of the resin to vacuum is 1.00005.

The short-circuit magnetic path prevention member 80 has a cylindrical shape centered on the axis N, and is arranged concentrically with the first yoke base portion 31, the coil 60, and the second yoke extension portion . The outer diameter of the short-circuit magnetic path prevention member 80 is set substantially equal to the diameter of the inner peripheral surface 42 i of the second yoke extension portion 42 . The inner diameter of the short-circuit magnetic path prevention member 80 is set substantially equal to the outer diameter of the first yoke second extension portion 33 . The length of the short-circuit magnetic path prevention member 80 in the direction of the axis N is set equal to the length from the upper surface (second facing surface 44) of the second yoke base portion 41 to the lower surface of the first extension portion 32 of the first yoke. It is

The short-circuit magnetic path prevention member 80 is interposed between the inner peripheral surface 42 i of the second yoke extension portion 42 and the outer peripheral portion of the first yoke second extension portion 33 . The short-circuit magnetic path prevention member 80 is also interposed between the inner peripheral surface 42 i of the second yoke extension portion 42 and the coil 60 . The short-circuit magnetic path prevention member 80 is also interposed between the inner peripheral surface 42 i of the second yoke extension portion 42 and the outer peripheral portion of the rotary plate 20 .

Furthermore, the short-circuit magnetic path prevention member 80 is sandwiched between the first yoke first extending portion 32 and the second yoke base portion 41 in the direction of the axis N without a gap. Thereby, the first yoke 30 is positioned in the direction of the axis N with respect to the second yoke 40 . By positioning in this manner, the dimension of the gap between the second facing surface 44 of the second yoke 40 and the first facing surface 34 of the first yoke 30 is defined.

(Effect)
According to the magneto-rheological fluid device 1 according to the present embodiment described above, the first yoke base portion 31 and the first yoke first extension portion 32 that constitute the first yoke 30 are integrally formed without interposing a dividing surface. Since it is formed, the magnetic resistance in the first yoke 30 is reduced, and the magnetic path can be efficiently formed.

Furthermore, according to the magneto-rheological fluid device 1, the first yoke base portion 31 and the first yoke second extension portion 33, which constitute the first yoke 30, are integrally formed without interposing a dividing surface. Magnetic resistance in the 1 yoke 30 is reduced, and a magnetic path can be efficiently formed.

Furthermore, according to the magneto-rheological fluid device 1, the second yoke base portion 41 and the second yoke extension portion 42, which constitute the second yoke 40, are integrally formed without intervening a dividing surface. The magnetic resistance at 40 is reduced, and the magnetic path can be efficiently formed.

Furthermore, according to the magneto-rheological fluid device 1, since the first yoke second extension part 33 is interposed between the rotating plate 20 and the coil 60, the coil 60 does not come into contact with the magneto-rheological fluid 50. As the magnetorheological fluid 50 flows, the magnetic particles contained in the magnetorheological fluid 50 do not wear the coil 60 .

Furthermore, according to the magneto-rheological fluid device 1, the short-circuit magnetic path preventing member 80 made of a non-magnetic material is interposed between the outer peripheral portion of the rotor plate 20 and the inner peripheral surface 42i of the second yoke extension portion 42. A short-circuited magnetic path R2 is prevented from being formed between the outer peripheral portion of the rotor plate 20 and the inner peripheral surface 42i of the second yoke extension portion 42 as shown in FIG. A magnetic field can be efficiently applied to the magneto-rheological fluid 50 .

Furthermore, according to the magneto-rheological fluid device 1, the short-circuit magnetic path prevention member made of a non-magnetic material is provided between the outer peripheral portion of the first yoke second extension portion 33 and the inner peripheral surface 42i of the second yoke extension portion 42. 80 is interposed, a short-circuit magnetic path R1 is formed between the outer peripheral portion of the first yoke second extension portion 33 and the inner peripheral surface 42i of the second yoke extension portion 42 as shown in FIG. is prevented, and a magnetic field can be efficiently applied to the magneto-rheological fluid 50 interposed in the first gap S1 and the second gap S2.

Furthermore, according to the magneto-rheological fluid device 1, the lower end of the short-circuit magnetic path prevention member 80 interposed between the outer peripheral portion of the rotor plate 20 and the inner peripheral surface 42i of the second yoke extension portion 42 is the second yoke base portion. 41, not only the magnetic path R2 short-circuiting from the rotating plate 20 to the inner peripheral surface 42i of the second yoke extension portion 42 as shown in FIG. 50 to the inner peripheral surface 42i of the second yoke extension 42 is prevented from being formed, and a magnetic field can be efficiently applied to the magneto-rheological fluid 50 interposed in the second gap S2. can.

Furthermore, according to the magneto-rheological fluid device 1, the short-circuit magnetic path prevention member 80 is sandwiched between the first yoke first extending portion 32 and the second yoke base portion 41 without a gap in the direction of the axis N, Since the dimension of the gap between the first opposing surface 34 and the second opposing surface 44 is defined, the total dimension of the first gap S1 and the second gap S2 can be adjusted to the design value with high accuracy.

Next, description will be given of second to seventh embodiments in which a part of the magneto-rheological fluid device 1 according to the first embodiment has a different configuration. For each embodiment after the second embodiment, only differences from the magneto-rheological fluid device 1 according to the above-described first embodiment will be described, and the same members that perform the same functions as the members in the magneto-rheological fluid device 1 will be described. are assigned the same reference numerals, and the description thereof is omitted.

<Second embodiment>
In the magneto-rheological fluid device 1 according to the above-described first embodiment, in a state in which the inner peripheral surface of the distal end portion of the second yoke extending portion 42 overlaps the outer peripheral surface of the first yoke first extending portion 32, the first The first yoke extension portion 32 and the second yoke extension portion 42 are bolted to each other, and the magnetic flux transfer portion 70 is formed parallel to the direction of the axis N, but the first yoke first extension portion 32 and the second yoke extension portion 42 are not limited to this direction. For example, it may be configured like a magneto-rheological fluid device 1A according to the second embodiment shown in FIG. In the magneto-rheological fluid device 1A, the first yoke first extension 32A of the first yoke 30A extends radially longer than the first yoke first extension 32 of the first embodiment, and the second yoke The upper end surface of the second yoke extending portion 42A of 40A overlaps the lower surface of the first yoke first extending portion 32A. The first yoke first extending portion 32A and the second yoke extending portion 42A are fastened together by a bolt B1 along the axis N direction. In the magneto-rheological fluid device 1A according to the second embodiment, the magnetic path transfer portion 70A is formed parallel to the radial direction.

<Third Embodiment>
In the magneto-rheological fluid device 1 according to the first embodiment, the first yoke second extension 33 is interposed between the coil 60 and the rotor plate 20. However, the third embodiment shown in FIG. It may be configured like the magneto-rheological fluid device 1B according to the embodiment. In the magneto-rheological fluid device 1B, the first yoke 30B does not have the first yoke second extension 33, and the short-circuit magnetic path prevention member 80B is interposed at the position of the first yoke second extension 33. there is The short-circuit magnetic path prevention member 80B has a base portion 81B and an extension portion 82B. The base portion 81B has the same shape as the short-circuit magnetic path prevention member 80 according to the first embodiment. The extending portion 82B is interposed between the coil 60 and the rotating plate 20 and extends radially inward from the base portion 81B to the first yoke base portion 31 . The lower surface of the extending portion 82B is aligned on the same plane as the first opposing surface 34 of the first yoke base portion 31, and forms a first gap S1 with the first main surface 21 of the rotating plate 20. .

According to the magneto-rheological fluid device 1B according to the third embodiment, the coil 60 can be prevented from coming into contact with the magneto-rheological fluid 50, and the magnetic path is formed from the first yoke base 31 to the second yoke extension 42. A radial short circuit can be prevented.

<Fourth Embodiment>
Like the magneto-rheological fluid device 1C according to the fourth embodiment shown in FIG. It may be provided downward to the same position in the direction of the axis N as (the first opposing surface 34). According to the magnetorheological fluid device 1</b>C according to the fourth embodiment, the number of turns of the coil 60</b>C can be increased compared to the magnetorheological fluid device 1 .

<Fifth Embodiment>
In the magneto-rheological fluid device 1 according to the above-described first embodiment, the short-circuit magnetic path prevention member 80 was interposed between the coil 60 and the second yoke extension 42, but the fifth embodiment shown in FIG. It may be configured like the magneto-rheological fluid device 1D according to the embodiment. In the magneto-rheological fluid device 1D according to the fifth embodiment, the short-circuit magnetic path preventing member 80 is not interposed between the coil 60 and the second yoke extension 42, and the coil 60D extends to the second yoke extension 42. radially expanded. According to the magneto-rheological fluid device 1D according to the fifth embodiment, the number of turns of the coil 60D can be increased. The magneto-rheological fluid device 1D according to the fifth embodiment has a short-circuit magnetic path preventing member 80D different from the short-circuit magnetic path preventing member 80 described in the first embodiment. The short-circuit magnetic path prevention member 80D in the fifth embodiment is interposed between the coil 60D and the second yoke base portion 41 in the direction of the axis N, and is located between the first yoke second extension portion 33 and the rotor plate 20 in the radial direction. 2 It is interposed between the yoke extension portion 42 . The short-circuit magnetic path prevention member 80D is composed of, for example, one cylindrical member.

<Sixth Embodiment>
In the magneto-rheological fluid device 1 according to the above-described first embodiment, the first yoke 30 is integrally formed without intervening a dividing surface. good. For example, in the magneto-rheological fluid device 1F according to the sixth embodiment shown in FIG. 9, the first yoke 30F has the same shape as the first yoke 30 according to the first embodiment, but the first yoke base 31 and the first yoke The first extending portion 32 and the first yoke second extending portion 33 are configured by separate members. Specifically, the first yoke 30F includes a first tube 31F and a second tube 31F as members corresponding to the first yoke base portion 31, the first yoke first extension portion 32, and the first yoke second extension portion 33, respectively. It has one upper annular plate 32F and a first lower annular plate 33F. The first upper annular plate 32F and the first lower annular plate 33F are fastened to the first tube 31F by bolts or the like (not shown).

<Seventh embodiment>
Similarly, in the magneto-rheological fluid device 1 according to the above-described first embodiment, the second yoke 40 is integrally formed without intervening a dividing surface, but the second yoke 40 is composed of a plurality of members. There may be. For example, in the magneto-rheological fluid device 1G according to the seventh embodiment shown in FIG. 10, the second yoke 40G has the same shape as the second yoke 40 according to the first embodiment, but the second yoke base 41 and the second yoke The extending portion 42 is configured by a separate member. Specifically, the second yoke 40G has a second lower disk 41G and a second tube 42G as members corresponding to the second yoke base portion 41 and the second yoke extension portion 42, respectively. The second lower disk 41G and the second tube 42G are fastened together with bolts B2.

<Other embodiments>
In the magneto-rheological fluid devices 1 to 1F according to the first to seventh embodiments, the rotating shaft 10 is provided so as to protrude greatly toward the first yoke 30 (upward) with respect to the rotating plate 20. However, the rotating shaft 10 may be provided so as to protrude greatly toward the second yoke base portion 41 (downward), or may be so arranged that the rotating shaft 10 penetrates the first yoke 30 and the second yoke 40 in the direction of the axis N. may be provided in

According to the present invention, for example, by interposing a magnetorheological fluid between members provided to be able to rotate relative to each other and changing the strength of the magnetic field applied to the magnetorheological fluid, the torque transmitted between the members can be changed. It can be applied to a magneto-rheological fluid device that can

Reference Signs List 1, 1A, 1B, 1C, 1D, 1F, 1G magneto-rheological fluid device 10 rotating shaft 20 rotating plate 21 first main surface 22 second main surface 30, 30A, 30B, 30C, 30F first yoke 31, 31F first first Yoke base 31c Peripheral surface of first yoke base 32, 32A, 32F First yoke first extension 33, 33F First yoke second extension 34 First opposing surface 40, 40A, 40G Second yoke 41 Second Yoke base 42, 42A Second yoke extension 42i Inner peripheral surface of second yoke extension 44 Second opposing surface 50 Magneto-rheological fluid 60, 60C, 60D Coil 70, 70A Magnetic flux transfer section 80, 80B, 80D Short-circuit magnet Road prevention member S1 First clearance S2 Second clearance N Axis

Claims (4)

a rotating plate fixed to a rotating shaft that rotates about an axis;
a first yoke having a first facing surface facing one main surface of the rotating plate with a first gap therebetween;
a second yoke having a second facing surface facing the other main surface of the rotating plate with a second gap therebetween;
a magneto-rheological fluid interposed between the first gap and the second gap;
a coil provided around the first yoke to form a magnetic flux in the first yoke when energized;
with
the first yoke and the second yoke each have a magnetic flux transfer section that transfers magnetic flux to each other;
When an electric current flows through the coil, the magneto-rheological fluid passing through the first yoke, the magneto-rheological fluid interposed in the first gap, the rotating plate, the magneto-rheological fluid interposed in the second gap, and the second yoke A magneto-rheological fluid device configured to form a path and apply a magnetic field to the magneto-rheological fluid interposed between the first gap and the second gap,
The first yoke is
a first yoke base having a peripheral surface through which the axis passes and around which the coil is arranged;
a first yoke first extending portion extending radially outward from the first yoke base portion such that the coil is interposed between the rotating plate;
has
The second yoke is
a second yoke base portion including the second opposing surface and arranged on the other main surface side of the rotating plate;
a second yoke extension extending from the second yoke base in the axial direction, passing through the outer side of the rotating plate, and forming the magnetic flux transfer section with the first yoke first extension; ,
has
A short-circuit magnetic path prevention member made of a non-magnetic material is interposed between the outer peripheral portion of the rotating plate and the inner peripheral surface of the second yoke extension,
A magneto-rheological fluid device characterized by: The magneto-rheological fluid device according to claim 1,
the first yoke further includes a first yoke second extension extending radially outward from the first yoke base through between the rotor plate and the coil;
The short-circuit magnetic path prevention member is interposed between the rotating plate and the outer circumference of the first yoke second extension and the inner circumference of the second yoke extension.
A magneto-rheological fluid device characterized by: The magneto-rheological fluid device according to claim 1 or 2,
One end of the short-circuit magnetic path prevention member is in contact with the second yoke base.
A magneto-rheological fluid device characterized by: The magneto-rheological fluid device according to claim 1 or 2,
The short-circuit magnetic path prevention member is interposed between the inner peripheral surface of the second yoke extension portion and the coil and between the inner peripheral surface of the second yoke extension portion and the rotating plate, The dimension of the gap between the first opposing surface and the second opposing surface is defined by being sandwiched between the first yoke first extending portion and the second yoke base without a gap in the axial direction. configured as
A magneto-rheological fluid device characterized by:

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