Magnetorheological fluid rotary load device and its control method

Abstract

The present invention relates to a magnetorheological fluid rotary load device and a control method thereof. The magnetorheological fluid rotary load device according to the present invention is characterized by including a housing, a yoke fixed within the housing, a shaft rotatably provided at the center of the housing, at least one rotary ring connected to the shaft and rotating in conjunction with the rotation of the shaft, a coil disposed within the housing, and a magnetorheological fluid filled within the housing.

Description

[Technical field]

[0001] The present invention relates to a magnetorheological fluid rotary loading device and a control method thereof, and more particularly to a magnetorheological fluid rotary loading device including a magnetorheological fluid, in which a rotational torque is adjusted as a magnetic field is applied to the magnetorheological fluid, and a control method thereof. [Background technology]

[0002] As user interfaces used in vehicles are becoming increasingly diverse, jog dials, which have been used primarily in household appliances, are now being introduced into vehicles as the main input device for Driver Information Systems (DIS) such as telematics terminals.

[0003] A jog dial is a rotatable circular dial that allows a user to select a specific function by rotating the dial clockwise or counterclockwise. When the user removes the force applied to the jog dial, the dial is positioned at a specific position, allowing for precise positional movement.

[0004] FIG. 1 is a schematic diagram showing a conventional jog dial. A conventional mechanical jog dial operates by meshing. As a result, the rotational tactile sensation of the conventional mechanical jog dial is limited to a single tactile sensation due to meshing and cannot express various tactile sensations according to rotation or use mode. In addition, the mechanical jog dial only has a fixed rotational torque due to meshing and cannot freely change the rotational torque. Even if a driving means such as a motor is further provided to control the rotational torque or a separate vibration motor for providing a haptic function is added, parts and devices must be added for that purpose, which increases the production cost and increases the volume of the device. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a magnetorheological fluid rotary load device and a control method thereof, which, unlike conventional mechanical structures that are monotonous and generate a single tactile pattern, generates a variety of tactile patterns in response to a variety of input signals during rotation, thereby providing the user with a diverse and luxurious tactile sensation.

[0006] In addition, according to one embodiment of the present invention, it is an object to provide a magnetorheological fluid rotating load device and a control method thereof that have a built-in haptic function, can change the rotational torque, reduce production costs, and can easily miniaturize the device.

[0007] It is another object of the present invention to provide a magnetorheological fluid rotary load device and a control method thereof that can be applied in a variety of ways according to purposes by using the shear characteristics and viscosity of the magnetorheological fluid.

[0008] However, such challenges are exemplary and are not intended to limit the scope of the invention. [Means for solving the problem]

[0009] The above-mentioned objects of the present invention are achieved by a magnetorheological fluid rotary load device comprising: a housing; a yoke portion fixed within the housing; a shaft rotatably provided within the housing; at least one rotating ring connected to the shaft and rotating in conjunction with the rotation of the shaft; a coil portion disposed within the housing; and a magnetorheological fluid filled within at least a portion of the housing, wherein at least a portion of the housing is made of a magnetic material.

[0010] According to one embodiment of the present invention, the content of magnetic particles in the magnetorheological fluid is 60 to 95 wt %.

[0011] Also, according to an embodiment of the present invention, as the content of magnetic particles in the magnetorheological fluid increases, the rotational torque acting between the yoke and the rotating ring increases.

[0012] Furthermore, according to one embodiment of the present invention, the size of the predetermined gap between at least the yoke portion and the rotating ring in which the magnetorheological fluid is disposed is 10 to 100 times the average diameter of the magnetic particles in the magnetorheological fluid.

[0013] Furthermore, according to one embodiment of the present invention, the greater the viscosity of the magnetorheological fluid, the greater the rotational torque acting between the yoke portion and the rotating ring.

[0014] In addition, according to one embodiment of the present invention, at least one of the viscosity of the magnetorheological fluid, the number of yoke portions and rotatable rings, the area of ​​the yoke portion and the rotatable ring, the size of the gap between the yoke portion and the rotatable ring, and the strength of the current applied to the coil portion can be set to a level that increases the maximum value of the rotational torque acting between the yoke portion and the rotatable ring, thereby preventing rotational operations in a specific user situation.

[0015] In addition, according to an embodiment of the present invention, the magnetorheological fluid may further include a control unit that controls a magnetic field applied to the magnetorheological fluid by the coil unit.

[0016] In addition, according to one embodiment of the present invention, before the operation of the magnetorheological fluid rotary load device, a preliminary input signal is transmitted from the control unit to the coil unit. The preliminary input signal is a signal for redispersing the precipitated particles of the magnetorheological fluid after they have formed an incomplete or complete chain shape in at least one of the vertical and horizontal directions within a predetermined gap.

[0017] Moreover, according to one embodiment of the present invention, the incomplete chain shape is a spike shape.

[0018] Furthermore, according to one embodiment of the present invention, when the control unit applies an operating voltage V1 to the coil unit, if it determines that the height of the chain formed by the particles of the magnetorheological fluid at a predetermined gap between the yoke unit and the rotating ring is lower than the height of the gap, it can apply a voltage V2 having a magnitude greater than V1.

[0019] Furthermore, according to one embodiment of the present invention, when the temperature rises compared to the initial operating temperature of the magnetorheological fluid rotating load device, the control unit can control either the strength or the pattern of the magnetic field to maintain the torque strength of the initial operating temperature.

[0020] Moreover, according to one embodiment of the present invention, at least one rotating ring is connected to the shaft with a gap between them, and the yoke portion may have a shape including a first surface facing the outer peripheral surface of the rotating ring, and a second surface facing the rotational surface of the rotating ring and perpendicular to the first surface.

[0021] Also, according to one embodiment of the present invention, the yoke portion is disposed on the outside of the rotating ring, and the coil portion is disposed between the yoke portion and the vertical inner side of the housing.

[0022] Moreover, according to one embodiment of the present invention, at least one rotating ring is connected to the shaft with a gap between them, and the yoke portion can have a shape including a first surface facing the outer peripheral surface of the rotating ring and a second surface not facing the outer peripheral surface of the rotating ring.

[0023] Furthermore, according to one embodiment of the present invention, the yoke portion is arranged vertically inside the housing, the coil portion is arranged between a second surface of the yoke portion and the shaft, and a protective portion is connected onto a surface of the coil portion that faces the rotating surface of the rotating ring.

[0024] Furthermore, according to one embodiment of the present invention, the yoke portion includes at least one yoke ring, the yoke ring and the rotating ring have a predetermined gap from each other and are arranged alternately along the vertical direction, the yoke portion is arranged outside the rotating ring, and the coil portion is arranged between the yoke portion and the vertical inner side of the housing.

[0025] In addition, according to one embodiment of the present invention, when a magnetic field is applied to the magnetorheological fluid from the coil portion, the particles of the magnetorheological fluid form chains in the vertical direction, thereby increasing the rotational torque acting between the yoke portion and the rotating ring.

[0026] In addition, according to one embodiment of the present invention, a fluid passage hole is formed on at least one of the rotation surface of the rotating ring or the surface of the yoke part facing the rotation surface of the rotating ring, and a magnetorheological fluid is disposed in a predetermined gap and fluid passage hole between the yoke part and the rotating ring. When a magnetic field is applied, as chains are formed vertically within the gap and fluid passage hole, the rotational torque acting between the yoke part and the rotating ring increases.

[0027] Also, according to an embodiment of the present invention, the fluid passing holes may be formed at an angle of 30 to 80° to the rotation surface of the rotation ring or to the surface of the yoke part facing the rotation surface of the rotation ring. In addition, according to one embodiment of the present invention, (1) a protruding pattern may be formed on the upper part of the rotational surface of the rotating ring or the surface of the yoke part opposite the rotational surface of the rotating ring, or (2) protruding patterns may be formed opposite each other or alternately on the rotational surface of the rotating ring and the upper part of the surface of the yoke part opposite the rotational surface of the rotating ring.

[0028] According to an embodiment of the present invention, protrusion patterns may be formed in a plurality of regions on at least one of a rotation surface of the rotation ring and a surface of a yoke portion facing the rotation surface of the rotation ring.

[0029] According to an embodiment of the present invention, the bearing may further include a bearing disposed in an upper portion of the housing, into which the axis of the shaft is inserted to control the rotational friction force. Effect of the Invention

[0030] According to the present invention configured as described above, unlike the conventional mechanical structure which generates a monotonous and single tactile pattern, various tactile patterns are generated in response to various input signals during rotation, thereby providing the user with a diverse and luxurious tactile sensation.

[0031] In addition, according to the present invention, a haptic function is built in, the rotation torque can be changed, production costs can be reduced, and the device can be easily miniaturized.

[0032] Furthermore, the present invention allows for a variety of applications that suit different purposes by utilizing the shear characteristics and viscosity of the magnetorheological fluid.

[0033] Of course, the scope of the present invention is not limited to such effects. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a schematic diagram showing a conventional jog dial. [Diagram 2] 1 is a schematic perspective view of a magnetorheological fluid rotary load device according to a first embodiment of the present invention. [Diagram 3] 1 is a schematic exploded view of a magnetorheological fluid rotary load device according to a first embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view of a magnetorheological fluid rotary load device according to a first embodiment of the present invention. [Diagram 5] 5 is an enlarged view of part V in FIG. 4. [Figure 6] FIG. 2 is a schematic diagram illustrating the behavior of a magnetorheological fluid in a gap space according to an embodiment of the present invention. [Figure 7] FIG. 5 is a schematic exploded view of a magnetorheological fluid rotary load device according to a second embodiment of the present invention. [Figure 8] FIG. 4 is a schematic cross-sectional view of a magnetorheological fluid rotary load device according to a second embodiment of the present invention. [Figure 9] 9 is an enlarged view of a portion VI in FIG. 8. [Figure 10] FIG. 11 is a schematic perspective view of a magnetorheological fluid rotary load device according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a schematic exploded view of a magnetorheological fluid rotary load device according to a third embodiment of the present invention. [Figure 12] FIG. 11 is a schematic cross-sectional view of a magnetorheological fluid rotary load device according to a third embodiment of the present invention. [Figure 13] 13 is an enlarged view of portion VII of FIG. 12. [Figure 14]4A and 4B are schematic diagrams showing a yoke part and a rotating ring in which a fluid passage hole is formed according to an embodiment of the present invention, and a schematic diagram showing a shape of a magnetic chain in the fluid passage hole; [Figure 15] 11 is a graph showing torque values ​​before and after the formation of fluid passage holes according to an example. [Figure 16] 4 is a schematic diagram showing a pattern shape on a horizontal surface of a yoke portion and a rotating ring according to an embodiment of the present invention. FIG. [Figure 17] 1 is a graph showing torque values ​​depending on the viscosity of a magnetorheological fluid according to an example of the present invention. [Figure 18] 4 is a schematic diagram illustrating a process in which a precipitated magnetorheological fluid is redispersed by application of a pre-input signal according to an embodiment of the present invention. FIG. [Figure 19] 4 is a diagram showing a spike-shaped magnetorheological fluid when a preliminary input signal is applied according to an embodiment of the present invention; [Figure 20] 1 is a graph showing torque values ​​depending on temperature of a magnetorheological fluid according to an example of the present invention. [Figure 21] 4 is a graph showing torque values ​​when applied to an anti-lock brake system (ABS) according to an embodiment of the present invention. [Figure 22] FIG. 2 is a schematic diagram illustrating a magnetorheological fluid rotating load module according to one embodiment of the present invention. [Figure 23] 1 is a diagram illustrating a state in which a magnetorheological fluid rotary load device according to various embodiments of the present invention is applied; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Reference is made to the accompanying drawings, which illustrate embodiments by way of example. These embodiments are described in detail to enable those skilled in the art to fully practice the invention. It should be understood that the various embodiments of the invention are different from one another, but are not necessarily mutually exclusive. For example, a particular shape, structure, and characteristic described herein may be embodied in other embodiments without departing from the spirit and scope of the invention. It should also be understood that the location or arrangement of individual components within each disclosed embodiment may be modified without departing from the spirit and scope of the invention. Therefore, the detailed description below is not intended to be taken in a limiting sense, and the scope of the invention is limited only by the appended claims, with all scope equivalent to what such claims are entitled to if properly described. Similar reference numerals in the drawings refer to the same or similar functions throughout the various aspects, and lengths, areas, thicknesses, and other shapes may be exaggerated for convenience.

[0036] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to enable those skilled in the art to easily carry out the present invention, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0037] Fig. 2 is a schematic perspective view of the magnetorheological fluid rotary loading device 100 according to the first embodiment of the present invention. Fig. 3 is a schematic exploded view of the magnetorheological fluid rotary loading device 100 according to the first embodiment of the present invention. Fig. 4 is a schematic cross-sectional view of the magnetorheological fluid rotary loading device 100 according to the first embodiment of the present invention. Fig. 5 is an enlarged view of part V in Fig. 4.

[0038] 2 to 5, the magnetorheological fluid rotary load device 100 of the first embodiment includes a housing 110, a shaft 120, a coil unit 130, a yoke unit 140, a rotating ring 150, and the magnetorheological fluid 10, and may further include a bearing 190.

[0039] The housing 110 provides a space (S) in which other components are disposed. The components of the magnetorheological fluid rotary load device 100 are disposed in the housing 110, and the magnetorheological fluid 10 is filled in the remaining empty space in the housing 110. The housing 110 may have a substantially cylindrical shape so as to provide the space (S) in which the shaft 120 and the rotating ring 150 can rotate, but may have other shapes as long as the housing 110 provides the space (S) in which the shaft 120 and the rotating ring 150 can rotate.

[0040] As an example, the housing (110:111, 115) may include a first housing 111 that provides a space (S) in which the coil portion 130, the yoke portion 140, the rotating ring 150, and the magnetorheological fluid 10 are disposed, and a second housing 115 that covers the top of the first housing 111 and seals the internal space (S) of the first housing 111.

[0041] After the components of the magnetorheological fluid rotary loading device 100 and the magnetorheological fluid 10 are placed in the space (S) of the first housing 111, the open upper part of the first housing 111 is covered with the second housing 115 to seal the inside. The present invention has the advantage that the assembly of the magnetorheological fluid rotary loading device 100 can be completed while sealing the magnetorheological fluid 10 with only the simple structure of the first and second housings (110: 111, 115).

[0042] The shaft 120 is rotatably installed at the center of the housing 110. The shaft 120 is installed to extend vertically, and a rotating ring (150: 151, 152) may be inserted into the axis of the shaft 120 to rotate together. Alternatively, the shaft 120 and the rotating ring 150 may be formed integrally. An edge portion 121 is formed at the upper end of the shaft 120, and a user grip means (not shown) such as a dial may be inserted into the edge portion 121 at the upper end of the shaft 120 to easily transmit a rotational force to the axis of the shaft 120. The lower end of the shaft 120 is placed in a shaft receiving groove 114 formed in the lower surface of the first housing 111, and is supported so that the position of the axis does not deviate from the shaft receiving groove 114 while the shaft 120 is rotating.

[0043] The coil unit 130 is disposed inside the housing 110. In order to apply a magnetic field uniformly inside the housing 110, the coil unit 130 is preferably in a ring shape with an opening formed in a shape corresponding to the vertical inner wall 112 of the housing 110, but is not limited thereto. The coil unit 130 is preferably a solenoid coil, and when a current is applied, it forms a magnetic field in a vertical direction (shaft axis direction). The magnetic field in the vertical direction causes the particles 11 of the magnetorheological fluid 10 to form a chain structure along the vertical direction (shaft axis direction), thereby controlling the rotational torque.

[0044] The yoke portion 140 is fixedly provided within the housing 110. The yoke portion 140 is fixedly provided such that the outer surface thereof faces the inner surface 131 of the opening of the coil portion .

[0045] The yoke portion 140 may have a shape including at least a first surface 143 and a second surface 144 [see FIG. 5] that face a rotatable ring (150: 151, 152) described below. In other words, the inner surface of the yoke portion 140 may include at least the first surface 143 and the second surface 144. More specifically, the yoke portion 140 may have a shape including a first surface (143: 143a, 143b) that faces an outer circumferential surface (153: 153a, 153b) [see FIG. 5] of the rotatable ring (150: 151, 152) and a second surface (144: 144a, 144b) that faces a rotation surface (154: 154a, 154b, 154c, 154d) of the rotatable ring (150: 151, 152) and is perpendicular to the first surface 143. The yoke part 140 may have a through hole 149 formed at the center thereof through which the shaft 120 can pass.

[0046] From another perspective, the yoke portion 140 is in the shape of a circular disk with a through hole 149 formed therein, and in addition, a cylindrical vertical wall 146 is formed vertically from the outer periphery of the circular disk, so that the shape of the cross section (see FIG. 4) is approximately 'H' shaped excluding the through hole 149. A rotating ring 150 is placed in the inner space of the yoke portion 140 where the vertical wall 146 is formed, so as to increase the corresponding surface area.

[0047] The rotating ring 150 has a circular disk shape as a whole, and is connected to the shaft 120. A through hole 159 corresponding to the outer diameter of the shaft 120 is formed in the rotating ring (150: 151, 152) and inserted into the shaft 120. The rotating ring 150 can rotate relatively to the fixed yoke part 140 in conjunction with the rotation of the shaft 120.

[0048] A plurality of rotating rings (150:151, 152) are disposed inside the housing 110, and the rotating rings (150:151, 152) are connected to the shaft 120 with a gap therebetween. In particular, a gap holding portion 155 having a step with the rotating surface 154 [or circular disk plane] of the rotating ring 152 may be formed in the center of any one of the rotating rings 152. It goes without saying that a through hole 159 is also formed in the gap holding portion 155. The through hole 149 of the yoke portion 140 may be formed to correspond to the outer diameter of the gap holding portion 155. Since the gap holding portion 155 is formed integrally with the rotating ring 150 with a step, there is an advantage in that only the rotating rings 150 are inserted into the shaft 120 in sequence without the need to insert a separate spacer into the shaft 120, and the spacing between the rotating rings 150 can be maintained.

[0049] 4 shows an example in which the yoke portion 140 is disposed between two rotating rings (150: 151, 152), but if there are three or more rotating rings, the number of yoke portions 140 will increase. In this case, the yoke portions 140 may be arranged in a vertically stacked manner while being alternately disposed with the rotating rings 150. After the coil portion 130 is fixed in the internal space (S) of the first housing 111, the rotating rings 150 and the yoke portion 140 are alternately stacked, and the shaft 120 is inserted, the magnetorheological fluid 10 is filled, and the internal space (S) is sealed with the second housing 115, completing the assembly process. The present invention has the advantage that the rotational torque can increase as the number or size of the yoke portions 140 and rotating rings 150 increases, and the magnetorheological fluid rotating load device 100 can be constructed through a simple process of assembling the yoke portions 140 and rotating rings 150 by alternately stacking them within the housing 110, so that it can flexibly accommodate size changes to provide a torque value suitable for the intended use.

[0050] A predetermined gap (G) is formed between the yoke part 140 and the rotatable ring 150, and the gap (G) is filled with magnetorheological fluid 10. Specifically, the gap (G) may be formed between the first surface 143 of the yoke part 140 and the outer circumferential surface 153 of the rotatable ring 150, and between the second surface 144 of the yoke part 140 and the rotation surface 154 of the rotatable ring 150. The gap (G) may also be formed between the housing 110 and the yoke part 140, and between the housing 110 and the rotatable ring 150. As the properties such as viscosity and rigidity of the magnetorheological fluid 10 filled in the gap (G) change, the rotation torque of the rotatable ring 150 may be changed.

[0051] The magnitude of torque (T) generated between rotatable ring 150 and yoke portion 140 due to the rotational motion of rotatable ring 160 can be calculated from the shear stress and the contact area as follows. T = Tc + Tη + Tf

[0052] Here, Tc is the controllable torque generated when an electric field or a magnetic field is applied, Tη is the viscous torque due to the viscosity of the magnetorheological fluid 10 when no electric field or magnetic field is applied, and Tf is the frictional torque generated by the mechanical elements. When there is no load, Tc does not appear.

[0053] Therefore, the present invention is characterized in that the overall torque (T) of the magnetorheological fluid rotary load device 100 can be freely changed as the magnetic field applied to the magnetorheological fluid 10 by the coil section 130 is controlled, i.e., as Tc is controlled.

[0054] FIG. 6 is a schematic diagram illustrating the behavior of a magnetorheological fluid 10 in a gap (G) space according to one embodiment of the present invention.

[0055] The magnetorheological fluid rotary loading device 100 may further include a control unit (not shown) that controls the strength, frequency, waveform, etc. of the magnetic field generated from the coil unit 130. When a user rotates the shaft 120 of the magnetorheological fluid rotary loading device 100, the control unit can change the magnetic field applied from the coil unit 130 to change the torque of the rotating ring 150.

[0056] 5 and 6, a gap (G) between the yoke portion 140 and the rotating ring 150 (or a gap (G) between the housing 110 and the yoke portion 140 and the rotating ring 150) is filled with a magnetorheological fluid 10. The magnetorheological fluid 10 includes magnetic particles 11 and a fluid-type medium 12 such as oil or water in which the magnetic particles 11 are dispersed.

[0057] In FIG. 6(a), when no magnetic field is applied, the magnetic particles 11 are dispersed in the medium 12. That is, when no load is applied, Tc=0, so T=Tη+Tf is a fixed value. Conversely, when a magnetic field is applied, the magnetic particles 11 may form a magnetic chain in the direction of the magnetic field. The chain may be formed so that it is in contact with one side of the yoke part 140 from one side of the rotating ring 150. As a result, the Tc value appears, so the torque increases to T=Tc+Tη+Tf, and the overall torque changes according to the change in the Tc value. As a result, the torque required for the shaft 120 to rotate may change depending on the strength of the magnetic field, the binding force of the magnetic chain, the friction shear force between the yoke part 140 and the rotating ring 150, etc. In order to better form the magnetic chain, at least the housing 110 includes a magnetic part, and the yoke part 140 and the rotating ring 150 may also include a magnetic part. Including a magnetic part includes a form in which the entire part is made of a magnetic material, or only a part is made of a magnetic material. Magnetic materials may include iron, nickel, cobalt, ferrite (Fe3O4) or alloys thereof, and metals that have been nitrided, oxidized, carbidized, siliconized, or the like.

[0058] The size of the gap (G) is preferably 10 to 100 times the average diameter of the magnetic particles 11 in the magnetorheological fluid 10, and more preferably about 20 times. If the gap (G) is too small, the torque value at no load increases or there is a problem of interference when the component rotates, and if the gap (G) is too large, it is disadvantageous to miniaturization of the device, and the magnetic chain is not sufficiently formed in a small magnetic field. For example, the diameter of the magnetic particles 11 is distributed in a range of about 2 to 10 μm, and the average diameter is about 5 μm. In this case, the gap (G) is about 0.1 mm, and within this numerical range, the magnetic particles 11 form a magnetic chain in the direction of the magnetic field and can induce a change in the Tc value to the extent that a change in the tactile sensation is transmitted to the user's hand. In addition, the more the magnetic particles 11 in the magnetorheological fluid 10, the stronger the magnetic chain is formed, and the maximum torque generated in the rotating load device increases, and the magnetic particles 11 in the magnetorheological fluid 10 are preferably 60 to 95 wt %. If the magnetic particles 11 are less than 60 wt%, the maximum torque will be reduced and the tactile sensation and rigidity transmission will not be sufficient for the user to feel, and if the magnetic particles 11 are more than 95 wt%, the torque value at no load will be high due to too many magnetic particles 11.

[0059] 6(b) shows a form in which the torque changes depending on the strength of the applied magnetic field. When an AC magnetic field is applied to the coil unit 130, a corresponding torque can be generated in the shaft 120. This allows various patterns and tactile sensations to be provided to the user who rotates the shaft 120 of the magnetorheological fluid rotary load device 100.

[0060] Meanwhile, the magnetorheological fluid rotary load device 100 may further include a bearing 190 disposed on the upper part of the housing 110. The bearing 190 is connected to the receiving groove 117 on the upper part of the housing 110, and the axis of the shaft 120 is inserted into the bearing 190 to control the rotational frictional force of the shaft 120. In addition, another bearing (not shown) may be inserted into the axis of the shaft 120 in the internal space of the housing 110.

[0061] Fig. 7 is a schematic exploded view of a magnetorheological fluid rotary load device 200 according to a second embodiment of the present invention. Fig. 8 is a schematic cross-sectional view of the magnetorheological fluid rotary load device 200 according to the second embodiment of the present invention. Fig. 9 is an enlarged view of a portion VI in Fig. 8.

[0062] The magnetorheological fluid rotary load device 200 of the second embodiment has substantially the same or similar appearance as the magnetorheological fluid rotary load device 100 of the first embodiment, as shown in Fig. 2. Hereinafter, only configurations different from the first embodiment will be described, and the same configurations are substituted with those described above. In the first and second embodiments, it can be noted that the same configurations are represented by reference numerals in the 100 and 200 series, which correspond to each other.

[0063] 2 and 7 to 9, the magnetorheological fluid rotary load device 200 of the second embodiment includes a housing 210, a shaft 220, a coil unit 230, a yoke unit 240, a rotating ring 250, and magnetorheological fluid 10, and may further include a bearing 290. The housing 210 and the shaft 220 are substantially the same as those of the first embodiment, except for some differences in shape.

[0064] The coil unit 230 is disposed inside the yoke unit 240, directly below or above rotating rings (250: 251, 252) spaced apart from each other and connected to the shaft 220. The through hole 239 of the coil unit 230 is formed only to the extent that the shaft 220 passes through to form a gap (G), and the outer circumferential surface of the coil unit 230 is connected to the inner surface 244 of the yoke unit 240 and fixedly supported.

[0065] The yoke portion 240 is fixedly installed within the housing 110. The outer peripheral surface of the yoke portion 240 is preferably in a shape corresponding to the vertical inner wall 212 of the housing 210 and is in a ring shape with an opening of a size in which the coil portion 230 is disposed, but is not limited thereto. The yoke portion 240 is fixedly installed such that its outer surface faces the vertical inner wall 212 of the housing 210.

[0066] The yoke portion 240 may have a shape including at least a first surface 243 facing the rotating ring (250: 251, 252) and a second surface 244 [see FIG. 9] not facing the rotating ring 250. In other words, the inner surface of the yoke portion 240 may include at least the first surface 243 and the second surface 244. More specifically, the yoke portion 240 may have a shape including a first surface (243: 243a, 243b) facing the outer circumferential surface (253: 253a, 253b) [see FIG. 9] of the rotating ring (250: 251, 252), and a second surface 244 not facing the rotating ring 250. The second surface 244 faces and is connected to the outer circumferential surface of the coil portion 230. From another perspective, the coil portion 230 is disposed between the second surface 244 of the yoke portion 240 and the shaft 220.

[0067] The rotating ring 250 has a circular disk shape as a whole, and is connected to the shaft 220. A through hole 259 corresponding to the outer axial diameter of the shaft 220 is formed in the rotating ring (250: 251, 252) and is inserted into the shaft 220. The rotating ring 250 can rotate relatively to the coil portion 230 fixed to the second surface 244 of the yoke portion 240 in conjunction with the rotation of the shaft 220.

[0068] A plurality of rotating rings (250: 251, 252) are disposed inside the housing 210, and the rotating rings (250: 251, 252) are spaced apart from each other and connected to the shaft 220. A coil unit 230 is disposed between the rotating rings (250: 251, 252), and a rotating surface 254 of the rotating ring 250 and upper and lower surfaces (234: 234a, 234b) of the coil unit 230 may face each other. A plurality of coil units 230 may be provided and disposed between the rotating rings 250, respectively.

[0069] A predetermined gap (G) is formed between the yoke unit 240 and the rotatable ring 250, and between the coil unit 230 and the rotatable ring 250, and the gap (G) is filled with the magnetorheological fluid 10. Specifically, the gap (G) may be formed between the first surface 243 of the yoke unit 240 and the outer circumferential surface 253 of the rotatable ring 250, and between the upper and lower surfaces 234 of the coil unit 230 and the rotation surface 254 of the rotatable ring 250. The gap (G) may also be formed between the housing 210 and the rotatable ring 250, and between the coil unit 230 and the shaft 220. As the properties such as viscosity and rigidity of the magnetorheological fluid 10 filled in the gap (G) change, the rotation torque of the rotatable ring 250 may be changed.

[0070] Meanwhile, a protective part 260 is connected to a surface 234 of the coil part 230 that faces the rotation surface 254 of the rotating ring 250. When the coil part 230 and the magnetorheological fluid 10 are in direct contact with each other, the magnetorheological fluid 10 can permeate into the gaps between the coils of the coil part 230. Thus, the flat protective part 260 can be disposed on the surface 234 of the coil part 230 that can come into contact with the magnetorheological fluid 10 to cover the gaps in the coil part 230.

[0071] In the present invention, the coil unit 230 and the rotatable ring 250 are closely spaced from each other while facing each other over a wide area, so that the magnetic field generated by the coil unit 230 is immediately applied to the magnetorheological fluid 10 that fills the gap (G) between the coil unit 230 and the rotatable ring 250. Since a strong magnetic field is applied to a wide area, more and stronger magnetic chains are formed, which has the advantage of significantly increasing the rotational torque.

[0072] The magnetorheological fluid rotary load device 200 of the second embodiment has an advantage over the first embodiment in that the coil unit 230 is not positioned outside the outer circumference of the rotatable ring 250 but is arranged on the upper or lower part of the rotatable ring 250, thereby reducing the diameter size of the entire device 200 due to the arrangement of the coil unit 230. In the first embodiment, the coil unit 130 is arranged outside the outer circumference of the yoke unit 140 and the rotatable ring 150, so the diameter size of the entire device 200 is relatively large.

[0073] In addition, in the magnetorheological fluid rotary load device 200 of the second embodiment, the coil unit 230 and the rotary ring 250 are adjacent to each other, so that the rotary torque can be significantly increased by applying a strong magnetic field. As a result, the device 200 can be applied to an object requiring a large torque, and can also be applied to a braking device such as a brake.

[0074] FIG. 10 is a schematic perspective view of a magnetorheological fluid rotary load device 300 according to a third embodiment of the present invention. FIG. 11 is a schematic exploded view of a magnetorheological fluid rotary load device 300 according to a third embodiment of the present invention. FIG. 12 is a schematic cross-sectional view of a magnetorheological fluid rotary load device 300 according to a third embodiment of the present invention. FIG. 13 is an enlarged view of a portion VII of FIG. 12. Hereinafter, only configurations different from the first embodiment will be described, and the same configurations are substituted by those described above. In the first and third embodiments, it can be seen that the same configurations correspond to each other with reference numerals in the 100s and 300s.

[0075] 10 to 13, the magnetorheological fluid rotary load device 300 includes a housing 310, a shaft 320, a coil unit 330, a yoke unit 340, and a rotary ring 350, and may further include a shield cover 380 and a bearing 390. The housing 310, the shaft 320, and the coil unit 330 are substantially the same as those in the first embodiment, except for some differences in shape.

[0076] The coil unit 330 is disposed inside the housing 310. In order to apply a magnetic field uniformly inside the housing 310, the coil unit 330 is preferably in a ring shape with an opening formed in a shape corresponding to the vertical inner wall of the housing 310, but is not limited thereto. The vertical magnetic field formed by the coil unit 330 causes the particles 11 of the magnetorheological fluid 10 to form chains along the vertical direction (shaft axial direction), thereby controlling the rotational torque.

[0077] The yoke portion (340: 340a, 340b, 340c) is fixed in the housing 310. The yoke portion 340 is fixed such that its outer surface faces the inner surface 331 of the opening of the coil portion 330.

[0078] The yoke portion 340 may have a shape including at least a first surface (343: 343a, 343b) facing the rotating ring (350: 351, 352) and a second surface 344 [see FIG. 13]. In other words, the inner surface of the yoke portion 340 may include at least the first surface 343 and the second surface 344.

[0079] The yoke portion (340: 340a, 340b, 340c) is fixed in the housing 310 and may include at least one yoke ring 340b. The yoke rings 340b are arranged alternately with the rotating rings (350: 351, 352) and form a predetermined gap (G) with the rotating rings (350: 351, 352) so that the gap (G) is filled with the magnetorheological fluid 10. In this specification, a form in which one yoke ring 340b is arranged between two rotating rings (350: 351, 352) is illustrated, but the number of rotating rings 350 and yoke rings 340b may be greater.

[0080] The yoke portion 340 includes an upper yoke 340a at its upper end and a lower yoke 340c at its lower end, with at least one yoke ring 340b disposed in an internal space formed by the upper yoke 340a and the lower yoke 340c.

[0081] The upper yoke 340a may constitute an upper wall and a side wall of the yoke unit 340. The upper yoke 340a may also have a substantially cylindrical shape to provide a space in which the shaft 320 and the rotating ring 350 can rotate, like the housing 310. The upper yoke 340a desirably has an inner diameter larger than the outer diameters of the rotating ring 350 and the yoke ring 340b. A through hole 349 into which the shaft 320 and the gap retainer 355 are inserted may be formed at the center of the upper surface of the upper yoke 340a. In addition, a plurality of fluid passing holes 347a may be formed on the upper surface of the upper yoke 340a.

[0082] At least one rotating ring (350: 351, 352) and at least one yoke ring 340b are disposed in the internal space of the upper yoke 340a. The yoke ring 340b is fixed in the internal space of the upper yoke 340a, and the rotating ring 350 is disposed above and / or below the yoke ring 340b and is provided to be rotatable in conjunction with the rotation of the shaft 320.

[0083] The yoke ring 340b is disposed on the upper and / or lower part of the rotating ring 350. The yoke ring 340b may have a circular disk shape as a whole such that the rotating ring 350 and the flat portions 344, 354 face each other. A through hole 349 into which the shaft 320 and the gap retainer 355 are inserted may be formed in the center of the yoke ring 340b.

[0084] Meanwhile, while the flat portions 344, 354 of the yoke ring 340b and the rotatable ring 350 face each other, a step is formed on the upper surface of the yoke ring 340b to reduce the overall height and increase the corresponding surface area, and the rotatable rings (350:351) are placed in the space formed by the step wall 346b.

[0085] The lower yoke 340c is provided under the upper yoke 340a to seal the lower part of the upper yoke 340a, the lower part of which is open. At the same time, the upper flat part of the lower yoke 340c faces the lower flat part of the rotating ring (350:352). In addition, a shaft receiving groove 348 is formed on the upper part of the lower yoke 340c to receive a part of the lower end of the shaft 320. This has the effect of preventing the shaft 320 from moving out of the shaft receiving groove 348 while rotating.

[0086] The interior is sealed by upper yoke 340a and lower yoke 340c, and rotatable rings 350 and yoke rings 340b are alternately arranged in the vertical direction in the internal space. The vertical direction corresponds to the direction in which the axis of shaft 320 is formed, and the horizontal direction corresponds to the planar direction of rotatable ring 350. As a result, there is a predetermined gap (G) between the inner surface of the upper part of upper yoke 340a, the upper and lower surfaces of yoke ring 340b, and the upper surface of lower yoke 340c and the upper and lower surfaces of rotatable ring 350 [see FIG. 13].

[0087] Meanwhile, a step is formed on the upper surface of the upper yoke 340a, and a shield cover 380 is placed in a space formed by a step wall 346a. The shield cover 380 seals the upper surface of the upper yoke 340a to prevent the magnetorheological fluid 10 from leaking out of the yoke part 340. The shield cover 380 has a hole 389 formed in the center so that the axis of the shaft 320 can pass through.

[0088] Conventional mechanical jog dials provide only a single tactile sensation, cannot provide a variety of patterns for various user modes, and suffer from wear due to mechanical operation. In addition to mechanical jog dials, there are also vibration motor type jogs, but the vibration motor type transmits a sense of contact through a vibration motor disposed at the bottom, rather than a direct tactile sensation, and therefore has a lower tactile sensation transmission power than a direct tactile sensation transmission.

[0089] Meanwhile, the present invention has the advantage that various torque patterns can be formed according to the input signal of the magnetic field applied from the coil unit 130, 230, 330, so that the user can feel various tactile sensations, and that the problem of wear is eliminated since the shear force is changed according to the change in state of the magnetorheological fluid 10, and that tactile sensations can be directly transmitted through the shaft 120, 220, 320.

[0090] In addition, the present invention can control the characteristics according to various application purposes by using the physical properties of the magnetorheological fluid 10. For example, if a heavy feel is required, a magnetorheological fluid 10 with high viscosity can be used.

[0091] 14 is a schematic diagram (a) and (b) showing the yoke parts 140, 340a, 340b and the rotating ring 150 with the fluid passage holes 147, 157, 347 formed therein according to an embodiment of the present invention, and a schematic diagram (c) and (d) showing the shape of the magnetic chain with the fluid passage holes 157 and 157'. FIG 15 is a graph showing the torque value before and after the formation of the fluid passage holes according to an experimental example.

[0092] 14(a) and (b), a plurality of fluid passage holes (147, 347: 347a, 347b) may be formed in the yoke portion 140, the upper yoke 340a, the yoke ring 340b, etc. Also, a plurality of fluid passage holes 157 may be formed in the rotating ring. The fluid passage holes 147, 157, 347 are formed to penetrate vertically on a horizontal plane such as the faces 344, 344 of the yoke portions 140, 340 and the rotating face 154 of the rotating ring 150. Also, without being limited thereto, the fluid passage holes may be formed to penetrate horizontally on a vertical plane such as the vertical wall 146 and the step walls 346a, 346b.

[0093] 14(c), the fluid passage hole 157 can further increase the length of the magnetic particles 11 of the magnetorheological fluid 10 forming a vertical chain (G1->G2). That is, the length of the chain of the magnetic particles 11 can be formed to a length that reaches the gap (G2) by adding the thickness of the fluid passage hole 157 from the thickness of the original gap (G, G1). This further increases the amount of change in the Tc value for the same applied load, and further increases the overall torque. According to an embodiment, when the diameter of the yoke part 140, 340 and the rotating ring 150 is about 10 mm, the diameter of the fluid passage holes 147, 157, 347 is about 0.3 mm.

[0094] 14(d), the fluid passage hole 157' does not necessarily have to be formed vertically (a=90°) but may be formed at an inclined angle (a). As the fluid passage hole 157' is formed at an incline, the chains of the magnetic particles 11 increase along the expanded surface area of ​​the fluid passage hole 157'. That is, in addition to the chains of the magnetic particles 11 being formed in the original gaps (G, G1) and the gap (G2) which is further added by the thickness of the fluid passage hole 157', the chains are further formed in the gap (G3) which extends from the inclined surface of the fluid passage hole 157' to the rotation surface 154 of the rotating ring 150 or the surface 144 of the yoke part 140. In particular, it is preferable that the inclination direction is formed along the rotation direction (R) of the rotating ring 150.

[0095] The inclined angle (a) may be set in consideration of the diameter, number, and strength of rotation torque of the fluid passage holes 157', and is preferably formed at an inclined angle (a) of 30 to 80 degrees. If it is less than 30 degrees, the fluid passage holes 157' may be penetrated to an excessively large size on the horizontal plane, making it difficult to exhibit the intended effect of the fluid passage holes, and if it is more than 80 degrees, there may be little difference in effect from the vertical fluid passage holes 157.

[0096] 15(a) and (b), when a load of 10 Hz and 100 Hz is applied, it can be seen that the torque is greater when there are fluid passage holes 147, 157, and 347. Furthermore, even when there is no load and no magnetic field is applied, it can be seen that the torque is greater when there are fluid passage holes 147, 157, and 347. This is believed to be the result of an increase in the friction torque Tf value due to the magnetorheological fluid 10 flowing into the fluid passage holes 147, 157, and 347.

[0097] Fig. 16 is a schematic diagram showing a pattern configuration on a horizontal plane of a yoke portion 140 and a rotating ring 150 according to an embodiment of the present invention. Fig. 16(a) is a schematic cross-sectional side view of the yoke portion 140 and the rotating ring 150, and Fig. 16(b1), (b2), and (b3) are schematic plan views.

[0098] 16(a), a protruding pattern (P1) may be formed on the surface 144 of the yoke part 140, or a protruding pattern (P2) may be formed on the rotation surface 154 of the rotation ring 150. The protruding patterns (P1, P2) may increase the surface area between the yoke part 140 and the rotation ring 150 to form more magnetic chains. This may increase the rotation torque of the magnetorheological fluid rotary load device 100 of the same size. In addition to the protruding patterns (P1, P2), the surface of the surface 144 of the yoke part 140 and the rotation surface 154 of the rotation ring 150 may be roughened to increase the surface roughness, thereby increasing the surface area and forming more magnetic chains.

[0099] The protruding patterns (P1, P2) may be formed on only one of the yoke portion 140 and the rotating ring 150, or on both of them. In addition, the protruding patterns (P1, P2) may be formed to face each other or alternately.

[0100] 16(b1), (b2), and (b3), the protruding patterns P3 and P4 may be formed in separate regions on the surfaces 144 and 154 of the yoke portion 140 and the rotating ring 150. The formation regions, formation intervals, angles, etc. of the protruding patterns P3 and P4 may be freely changed.

[0101] As an example, the protruding patterns (P3, P4) are formed on the yoke part 140 and the rotating ring 150 to face each other, and a total of eight of them may be formed radially at 45° intervals. In FIG. 16 (b1), the user can rotate the shaft 120 in a clockwise direction based on the point SP1. At this time, the protruding patterns (P3, P4) face each other, and the magnetic chain is formed within a short gap (corresponding to the distance between the protruding patterns), so a relatively strong torque (T1) can act. Next, as shown in FIG. 16 (b2), when rotating at the point SP2, in the region where the protruding patterns (P3, P4) do not face each other, the magnetic chain is formed within a relatively long gap (corresponding to the distance between the yoke part and the surface of the rotating ring), so a relatively weak torque (T2) can act. As the torque weakens from T1 to T2, the user can be provided with a tactile sensation of a loose rotation. 16(b3), when the rotation reaches point SP3, the protruding patterns P3 and P4 face each other again and the magnetic chain is formed within a short gap (corresponding to the distance between the protruding patterns), so a relatively strong torque T1 acts. As the torque weakens from T2 to T1, the user may be provided with a tactile sensation of the rotation being harder. In this way, the user may be provided with a tactile sensation of the torque varying by region as he or she rotates the shaft 120.

[0102] 17 is a graph showing torque values ​​depending on the viscosity of a magnetorheological fluid according to an embodiment of the present invention. As an example, the standard viscosity was set to about 0.15 Pa s, the high viscosity was set to about 0.4 Pa s, and the density was set to about 2.8 g / ml and 3.8 g / ml.

[0103] 17(a) and 17(b), it can be seen that the torque is larger in the case of the high viscosity magnetorheological fluid 10 when a load is applied at 10 Hz and 100 Hz. Thus, a torque value that is difficult to realize even when the load voltage is increased to 10 V or more with a standard viscosity can be realized through the high viscosity magnetorheological fluid 10. For example, a torque larger than 1.5 mN·m is difficult to realize with a standard viscosity based on 5 V, but a torque larger than 2 mN·m can be realized with a high viscosity. In particular, when a load of 12 V is used in a vehicle, the realized torque value can be increased to the maximum, and an application can be made to prevent the rotation of the rotating load device in a specific situation (such as a dangerous situation or while driving). In this way, a safety lock function that prevents a user from rotating the magnetorheological fluid rotating load device 100 can be applied by setting the viscosity of the magnetorheological fluid 10 to increase the maximum torque to the magnetorheological fluid rotating load device 100. As long as the safety lock function is within the range of preventing the user from rotating the device at the maximum torque value, it can be realized by structural changes such as increasing the number and area (facing area, surface area, etc.) of the rotating ring and the yoke, or reducing the gap (G) in addition to adjusting the viscosity.The safety lock function can also be realized by applying a larger current to the coil.

[0104] The safety lock function not only ensures safety by preventing dangerous operations while driving a vehicle (for example, changing gears by a jog dial while driving), but can also prevent children from operating household appliances such as washing machines in an unexpected manner.

[0105] 18 is a schematic diagram showing a process in which the precipitated magnetorheological fluid is redispersed by application of a preliminary input signal according to an embodiment of the present invention, and FIG 19 is a diagram showing a spike-shaped magnetorheological fluid when a preliminary input signal is applied according to an embodiment of the present invention.

[0106] When the magnetorheological fluid 10 is applied, the settling of the magnetic particles 11 in the fluid 12 becomes an issue. If the magnetic particles are not uniformly distributed inside the housing 110 because the magnetic particles sink down over time, the magnetic chains are not formed properly. Or, as the magnetorheological fluid rotary load device 100 is continuously used, the magnetic particles 11 are concentrated in a specific part in the gap (G) between the yoke part 140 and the rotary ring 150. For example, in the device 100 of the first embodiment, the outer parts of the yoke part 140 and the rotary ring 150 are close to the solenoid coil part 130, so many chains are formed, and the inner part closer to the axis of the shaft 120 is farther from the solenoid coil part 130, so that the chains are formed relatively less due to a weak magnetic field. In this way, the magnetic particles 11 are concentrated only in a specific area in the gap (G) due to the settling of the magnetic particles 11, and the magnetic particles 11 may be settled and concentrated in a lower area in the housing 110. If the magnetorheological fluid rotary load device 100 is immediately operated in this state, a torque of a size different from the default size will be generated.

[0107] Therefore, the present invention is characterized in that, in order to smoothly redisperse magnetic particles 11 when they are precipitated in the magnetorheological fluid rotary loading device 100, a preliminary input signal in the form of a spike, pulse, or sine wave is transmitted from a control unit (not shown) to the coil unit 130 before the operation of the magnetorheological fluid rotary loading device 100. If the magnetorheological fluid rotary loading device 100 does not operate for a set time or more, the control unit can transmit a preliminary input signal to the coil unit 130 before operation.

[0108] The preliminary input signal is different from the input signal constituting the magnetic chain described above in FIG. 6. The preliminary input signal is a signal that causes the magnetic particles in the magnetorheological fluid 10 to move and form an incomplete or complete chain in at least one of the vertical and horizontal directions in the gap (G), and is a signal that applies a single or multiple strong magnetic fields without having a specific frequency, waveform, etc. Also, the preliminary input signal does not need to be a signal that causes the magnetic particles 11 to form a complete magnetic chain that connects from the lower surface of the gap (G) [for example, the upper surface of the rotating ring 150] to the upper surface of the gap (G) [for example, the lower surface of the yoke part 140]. FIG. 19 illustrates various spike shapes that are incomplete chain shapes made of magnetic particles.

[0109] When a magnetic field is applied from the coil unit 130 through a preliminary input signal, the precipitated particles 11 in the magnetorheological fluid 10 form an incomplete chain shape like a spike in the direction of the magnetic field, and at the same time or immediately after, the application of the magnetic field is removed or only a weak magnetic field is applied, which results in the spike shape being released and the magnetic particles 11 that formed an incomplete chain shape like a spike expanding and being redispersed from within the gap (G).

[0110] On the other hand, if the control unit determines that the height of the magnetic chain formed at the smallest height in the gap (G) between the yoke portion 140 and the rotating ring 150 is lower than the height of the gap (G) when the operating voltage V1 of the magnetorheological fluid rotating load device 100 is applied, it can apply a preliminary input signal voltage V2 greater than V1 to resolve this.

[0111] FIG. 20 is a graph showing torque values ​​as a function of temperature for a magnetorheological fluid according to an example of the present invention.

[0112] 20, it can be seen that the torque gradually decreases as the temperature rises from the initial state (default state) (operating state of the rotating load device) due to the change in the viscosity and shear stress characteristics of the magnetorheological fluid based on the 5V standard. Therefore, after detecting the operating temperature of the magnetorheological fluid rotating load device, if the temperature rises compared to the initial operating temperature, the control unit controls the strength and pattern of the magnetic field to offset the torque reduction caused by the temperature rise, thereby maintaining the torque strength at the initial operating temperature even in a high temperature state. This has the advantage of ensuring uniformity of the torque value regardless of the external temperature environment, such as summer or winter.

[0113] FIG. 21 is a graph showing torque values ​​when applied to an ABS system according to an embodiment of the present invention.

[0114] As described above, in the magnetorheological fluid rotary load device of the present invention, the torque can be increased by stacking the yoke unit 140 and the rotating ring 150 in multiple layers or increasing the surface area, and the torque can be increased by arranging the coil unit 2230 closest to the rotating ring 250 as in the second embodiment. This allows the magnetorheological fluid rotary load device to be applied to an object requiring a large torque. The object can be a means of transportation such as a vehicle, and the magnetorheological fluid rotary load device can be a braking device such as a brake.

[0115] In particular, the present invention can realize various torque values ​​by only changing the strength and pattern of the magnetic field applied from the coil unit, without the need to control the instantaneous change of various torque values ​​by adopting a complex structure and various parts as in the conventional mechanical braking device. Therefore, the magnetorheological fluid rotary load device of the present invention can be applied to the ABS system to realize the torque change as shown in Figure 21.

[0116] When a vehicle brakes suddenly, if the tires lock up instantaneously, the vehicle loses braking force and slides on the ground due to inertia (travel speed). The maximum static friction occurs at the moment the vehicle slides, and after the slide, kinetic friction, which is a relatively small friction force, acts. The ABS system repeatedly creates short moments when the maximum static friction is active, and continuously creates points where static friction turns into kinetic friction, thereby maximizing friction.

[0117] Conventional ABS systems require an ABS modulator, including a pump and accumulator for controlling hydraulic pressure and pressure reduction in the brakes, and are limited in how fast the static friction force can be activated. On the other hand, the magnetorheological fluid rotary load device of the present invention has the advantage of being able to realize an ABS system with a simple configuration that controls the strength and period of the magnetic field applied.

[0118] According to one embodiment, in order to improve the inability to steer the vehicle due to wheel lock during sudden braking of the vehicle, the wheel slip ratio can be maintained at a level of 20%. The slip ratio (%) is calculated as {V (vehicle speed) - V (wheel speed)} / V (wheel speed).

[0119] The braking system to which the present invention is applied has the advantages of improving durability problems caused by repeated hydraulic brake control, enabling accurate brake control, and preventing frequent breakdowns of the ABS modulator.

[0120] Fig. 22 is a schematic diagram showing a magnetorheological fluid rotary load module according to an embodiment of the present invention, and Fig. 23 shows a state in which a magnetorheological fluid rotary load device according to various embodiments of the present invention is applied.

[0121] It is possible to apply it as a rotational load module by combining various units with the magnetorheological fluid rotational load device 300. According to one embodiment, the magnetorheological fluid rotational load module is a form in which an encoder sensor 400 is combined with the magnetorheological fluid rotational load device 300. In general, a bearing 390 and a shaft 320 are combined to reduce rotational friction, but an encoder sensor 400 in which the bearing 390 is combined with an encoder that senses data on the rotational speed, position, and direction can be combined with the magnetorheological fluid rotational load device 300.

[0122] The magnetorheological fluid rotary load device and rotary load module can be applied to any device equipped with a dial or wheel.

[0123] As an example, when applied to a vehicle, when a jog dial (rotation load device) is set in a normal driving mode, a light vibration and a small torque feel can be provided, while when the jog dial is set in a sports driving mode, a strong vibration and a strong torque feel can be provided. As another example, when turning a jog dial to change gears in a vehicle, different vibration and torque intensities can be provided depending on parking (P), driving (D), neutral (N), and reverse (R). This allows a user to easily change driving modes and gears by touch alone, with their eyes fixed on the road, without having to check the jog dial with their naked eyes.

[0124] 23(a), the magnetorheological fluid rotary load device 100 is applied to a UI (user interface) of a washing machine 400, a microwave oven, etc., and a dial [shaft 120] is positioned at a position corresponding to each driving mode, so that various tactile sensations can be provided according to the driving mode. For example, when the washing machine 400 is set to a normal washing mode, a soft rotation sensation can be provided, and when the washing machine is set to a powerful washing mode, a strong torque rotation sensation can be provided.

[0125] Also, as shown in FIG. 23(b), when applied to the wheel of the mouse 500, the torque of the wheel operation changes depending on the usage environment, and various haptic sensations can be provided. For example, when a crisis occurs during a game, the torque for driving the wheel becomes stronger. Also, as shown in FIG. 23(c), when playing a brick breaking game 600 that moves left and right using a mouse wheel, the wheel is operated up and down to move the reflector 610 left and right. When the wheel is driven upward and the reflector 610 moves to the left edge and there is no space to move any further, the torque of the mouse wheel driving upward becomes strong, making further operation difficult, and only the mouse wheel driving downward is permitted. Also, at the moment when the ball 620 reflects off the reflector 610, the rigidity of the wheel can be changed instantly to immediately provide the user with a haptic sensation of the ball 620 being reflected.

[0126] As described above, the present invention has the effect of providing a user with a variety of tactile sensations and a sense of luxury by creating various patterns according to various input signals when a rotary load device is rotated. In addition, the present invention has the effect of reducing production costs by changing the rotation torque, facilitating miniaturization of the device, and enabling various applications according to purposes using the shear characteristics and viscosity of the magnetorheological fluid 10.

[0127] Although the present invention has been illustrated and described with reference to the preferred embodiment as described above, the present invention is not limited to the above embodiment, and various modifications and alterations may be made by those skilled in the art without departing from the spirit of the present invention. Such modifications and alterations are to be regarded as falling within the scope of the present invention and the appended claims. [Explanation of symbols]

[0128] 10 Magnetorheological fluid 11 Magnetic particles 12 Medium 100, 200, 300 Magnetorheological fluid rotating load device 110, 210, 310 Housing 120, 220, 320 shaft 130, 230, 330 Coil section 140, 240, 340 Yoke section 150, 250, 350 rotating ring G Gap

Claims

1. Housing and a yoke portion fixed within a housing; A shaft rotatably disposed within the housing; At least one rotating ring connected to the shaft and rotating in conjunction with the rotation of the shaft; A coil portion disposed within the housing; a magnetorheological fluid filling at least a portion of the housing; A control unit that controls a magnetic field applied to the magnetorheological fluid by the coil unit; Including, At least a portion of the housing is constructed from a magnetic material; the size of the predetermined gap between at least the yoke portion and the rotating ring in which the magnetorheological fluid is disposed is 10 to 100 times the average diameter of the magnetic particles in the magnetorheological fluid; A magnetorheological fluid rotating load device in which, when the control unit applies an operating voltage V1 to the coil unit, if it determines that the height of the chain formed by the magnetorheological fluid particles in a specified gap between the yoke unit and the rotating ring is lower than the height of the gap, it applies a voltage V2 of greater strength than V1.

2. Housing and a yoke portion fixed within a housing; A shaft rotatably disposed within the housing; At least one rotating ring connected to the shaft and rotating in conjunction with the rotation of the shaft; A coil portion disposed within the housing; a magnetorheological fluid filling at least a portion of the housing; A control unit that controls a magnetic field applied to the magnetorheological fluid by the coil unit; Including, At least a portion of the housing is constructed from a magnetic material; the size of the predetermined gap between at least the yoke portion and the rotating ring in which the magnetorheological fluid is disposed is 10 to 100 times the average diameter of the magnetic particles in the magnetorheological fluid; Compared to the initial operating temperature of the magnetorheological fluid rotating load device, when the temperature rises, The control unit controls one of the strength and pattern of a magnetic field to maintain the torque strength at the initial operating temperature.

3. Housing and a yoke portion fixed within a housing; A shaft rotatably disposed within the housing; At least one rotating ring connected to the shaft and rotating in conjunction with the rotation of the shaft; A coil portion disposed within the housing; a magnetorheological fluid filling at least a portion of the housing; Including, At least a portion of the housing is constructed from a magnetic material; the size of the predetermined gap between at least the yoke portion and the rotating ring in which the magnetorheological fluid is disposed is 10 to 100 times the average diameter of the magnetic particles in the magnetorheological fluid; A fluid passage hole is formed in at least one of a rotation surface of the rotation ring and a surface of the yoke portion facing the rotation surface of the rotation ring, A magnetorheological fluid rotating load device in which a magnetorheological fluid is disposed in a predetermined gap and fluid passage hole between a yoke portion and a rotating ring, and when a magnetic field is applied, as chains are formed vertically within the gap and fluid passage hole, the rotational torque acting between the yoke portion and the rotating ring increases.

4. 4. The magnetorheological fluid rotary load device according to claim 1, wherein the content of the magnetic particles in the magnetorheological fluid is 60 to 95 wt %.

5. 4. The magnetorheological fluid rotary load device according to claim 1, wherein the rotational torque acting between the yoke portion and the rotating ring increases as the content of magnetic particles in the magnetorheological fluid increases.

6. 4. The magnetorheological fluid rotary load device according to claim 1, wherein the rotational torque acting between the yoke portion and the rotating ring increases as the viscosity of the magnetorheological fluid increases.

7. A magnetic rheological fluid rotating load device as described in any one of claims 1 to 3, wherein at least one of the viscosity of the magnetic rheological fluid, the number of yoke portions and rotating rings, the area of ​​the yoke portion and the rotating ring, the size of the gap between the yoke portion and the rotating ring, and the strength of the current applied to the coil portion is set to a degree that increases the maximum value of the rotational torque acting between the yoke portion and the rotating ring, thereby preventing rotational operations in a specific user situation.

8. Before the magnetorheological fluid rotary load device operates, a preliminary input signal is transmitted from the control unit to the coil unit.

3. The magnetic rheological fluid rotary load device according to claim 1 or 2, wherein the preliminary input signal is a signal for redispersing precipitated particles of the magnetic rheological fluid after they have formed incomplete or complete chains in at least one of the vertical and horizontal directions within a predetermined gap.

9. The magnetorheological fluid rotary load device according to claim 8 , wherein the incomplete chain shape is a spike shape.

10. A plurality of rotatable rings are connected to the shaft at intervals; A magnetic rheological fluid rotating load device as described in any one of claims 1 to 3, wherein the yoke portion has a shape including a first surface facing the outer peripheral surface of the rotating ring, and a second surface facing the rotational surface of the rotating ring and perpendicular to the first surface.

11. 11. The magnetorheological fluid rotary load device according to claim 10, wherein the yoke portion is disposed on the outside of the rotary ring, and the coil portion is disposed between the yoke portion and a vertical inner side of the housing.

12. A plurality of rotatable rings are connected to the shaft at intervals; 4. The magnetorheological fluid rotating load device according to claim 1, wherein the yoke portion has a shape including a first surface that faces an outer circumferential surface of the rotating ring and a second surface that does not face the outer circumferential surface of the rotating ring.

13. The yoke portion is disposed vertically inside the housing, The coil portion is disposed between the second surface of the yoke portion and the shaft, 13. The magnetorheological fluid rotary load device according to claim 12, wherein a protective portion is connected onto a surface of the coil portion that faces the rotation surface of the rotating ring.

14. The yoke portion includes at least one yoke ring; The yoke ring and the rotating ring are alternately arranged along a vertical direction with a predetermined gap between them, 4. The magnetorheological fluid rotary load device according to claim 1, wherein the yoke portion is disposed on the outside of the rotating ring, and the coil portion is disposed between the yoke portion and a vertical inner side of the housing.

15. A magnetic rheological fluid rotating load device as described in any one of claims 1 to 3, wherein when a magnetic field is applied to the magnetic rheological fluid from the coil portion, particles of the magnetic rheological fluid form chains in the vertical direction, thereby increasing the rotational torque acting between the yoke portion and the rotating ring.

16. 4. The magnetorheological fluid rotary load device according to claim 3, wherein the fluid passage holes are formed at an angle of 30 to 80 degrees on the rotation surface of the rotation ring or on a surface of the yoke portion opposed to the rotation surface of the rotation ring.

17. (1) A protruding pattern is formed on the upper portion of the rotating surface of the rotating ring or the surface of the yoke part facing the rotating surface of the rotating ring, (2) A magnetic rheological fluid rotating load device as described in any one of claims 1 to 3, in which protruding patterns are formed opposite each other or alternately on the upper part of the rotating surface of the rotating ring and the surface of the yoke portion opposite the rotating surface of the rotating ring.

18. 4. A magnetic rheological fluid rotating load device as described in any one of claims 1 to 3, wherein a protrusion pattern is formed in multiple regions on at least one of the rotating surface of the rotating ring and the surface of the yoke portion facing the rotating surface of the rotating ring.

19. 4. The magnetorheological fluid rotary load device according to claim 1, further comprising a bearing disposed in an upper portion of the housing, into which an axis of the shaft is inserted to control rotational friction force.

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