Improved t-shaped rotor-type haptic actuator based on magnetorheological fluid

Abstract

The present invention relates to an improved T-shaped rotor-type haptic actuator based on a magnetorheological (MR) fluid, wherein an improved T-shaped rotary shaft and a magnetic induction ring are used to induce a high magnetic field in the MR fluid and thereby increase the viscosity of the MR fluid, thus making it possible to simultaneously satisfy a shear mode and a flow mode of the MR fluid and generate a higher rotational resistance force.

Description

An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids

[0001] The present invention relates to an improved T-shaped rotor type haptic actuator based on a magnetorheological fluid, and more particularly, to an improved T-shaped rotor type haptic actuator based on a magnetorheological fluid, which can simultaneously satisfy the shear mode and the flow mode of the MR fluid and generate higher rotational resistance by inducing a high magnetic field in the MR fluid using an improved T-shaped rotating shaft and a magnetic induction ring to increase the viscosity of the MR fluid.

[0002]

[0003] In general, magnetorheological fluids (MR fluids) exhibit a phenomenon similar to ER (ELECTRO-RHEOLOGICAL) fluids, with the effect of increasing fluid flow resistance when subjected to a magnetic field. MR fluids are composed of paramagnetic particles dispersed in a low-permeability solvent. When no magnetic field is applied, they exhibit behavior similar to that of a Newtonian fluid, in which the particles move freely. However, when subjected to a magnetic field, the particles become charged and form chain structures, exhibiting behavior similar to that of a Bingham fluid with a yield stress.

[0004] These MR fluids are used in the design, manufacture, positioning, vibration control and rotation of various application devices, such as vehicle shock absorbers, impact dampers, engine mounts and vehicle suspensions.

[0005] Meanwhile, rotating bodies using MR fluids are generally broadly categorized into drum structures, disk structures, and T-shaped structures. MR fluids have the characteristic of increasing viscosity depending on the strength of the magnetic field. However, in conventional rotating bodies using MR fluids, the viscosity increase of the MR fluid due to magnetic field induction is somewhat limited. Therefore, technological development is required to generate greater rotational resistance.

[0006]

[0007] The present invention aims to solve the above problems by providing an improved T-shaped rotor-type haptic actuator based on magnetorheological fluid, which can simultaneously satisfy the shear mode and flow mode of the MR fluid and generate higher rotational resistance by inducing a high magnetic field in the magnetorheological fluid (MR fluid) using an improved T-shaped rotating shaft and a magnetic induction ring to increase the viscosity of the MR fluid.

[0008]

[0009] An improved T-shaped rotor type haptic actuator (100) based on a magnetorheological fluid according to one embodiment of the present invention comprises: an actuator housing (110), an actuator housing cover (120) covering the upper side of the actuator housing (110), a rotating part (130) accommodated in the housing (110) and partially exposed to the outside through the actuator housing cover (120) and provided to be rotatable within the housing (110), an MR fluid (140) provided inside the actuator housing (110) and filled between the inner wall of the actuator housing (110) and the rotating part (130), a solenoid coil (150) provided in a ring shape inside the actuator housing (110), and a solenoid coil (150) provided in a ring shape inside the actuator housing (110) and the solenoid coil (150) and the It may include a magnetic induction ring (160) positioned between the rotating parts (130).

[0010] In one embodiment, the actuator housing cover (120) may include a lower housing cover (121) connected to the actuator housing (110) and having a through hole (121a) formed therein for exposing the rotating part (130) to the outside, an upper housing cover (122) connected to the upper side of the lower housing cover (121) and having a through hole (122a) formed therein for exposing the rotating part (130) to the outside, an O-ring (123) provided in the through hole (121a) to prevent the MR fluid (140) from leaking to the outside, and a bearing (124) provided in the through hole (122a) to prevent friction with the rotating part (130).

[0011] In one embodiment, the rotating part (130) may include a cylindrical rotating part body (131) accommodated inside the actuator housing (110), a rotating shaft (132) accommodated inside the actuator housing (110) and formed integrally with the upper side of the rotating part body (131) to have a diameter larger than that of the rotating part body (131), and a rotating shaft (133) formed integrally with the upper side of the rotating shaft (132) and protruding to the outside through the through hole (121a, 122a).

[0012] In one embodiment, the rotating shaft (132) may be formed in a sawtooth shape with one or more bumps protruding along the periphery of the edge.

[0013] In one embodiment, the magnetic induction ring (160) may correspond to a non-magnetic material.

[0014]

[0015] According to one aspect of the present invention, by inducing a high magnetic field in a magnetorheological fluid (MR fluid) using an improved T-shaped rotation shaft and a magnetic induction ring to increase the viscosity of the MR fluid, it has the advantage of simultaneously satisfying the shear mode and flow mode of the MR fluid, as well as generating a higher rotational resistance.

[0016]

[0017] FIG. 1 is a drawing showing the configuration of an improved T-shaped rotor type haptic actuator (100) based on a magnetorheological fluid according to one embodiment of the present invention.

[0018] FIG. 2 is a cross-sectional view of an improved T-shaped rotor type haptic actuator (100) based on magnetorheological fluid illustrated in FIG. 1.

[0019] Figure 3 is a drawing showing the rotating part (130) illustrated in Figure 1 in more detail.

[0020] FIG. 4(a) is a diagram showing the structure of the rotating shaft (132) shown in FIG. 3, and FIG. 4(b) is a diagram showing simulation results for the torque resistance change amount according to various shapes of the rotating shaft (132) and the number of bumps of the rotating shaft (132), respectively.

[0021] Figures 5(a) and 5(b) are diagrams showing the shear mode and flow mode of each bump and non-bump area and the simulation results accordingly.

[0022] Figure 6 is a drawing showing a magnetic field path induced in the MR fluid (140) illustrated in Figure 2.

[0023] FIG. 7(a), FIG. 7(b), and FIG. 7(c) are diagrams showing simulation results for the magnetic field path induced in the MR fluid (140) with and without the magnetic induction ring (160) illustrated in FIG. 2, respectively.

[0024]

[0025] Hereinafter, preferred examples are presented to aid in understanding the present invention. However, the following examples are provided solely to facilitate a better understanding of the present invention, and the scope of the present invention is not limited by the examples.

[0026]

[0027] FIG. 1 is a drawing showing the configuration of an improved T-shaped rotor type haptic actuator (100) based on a magnetorheological fluid according to one embodiment of the present invention, and FIG. 2 is a drawing showing a cross-section of the improved T-shaped rotor type haptic actuator (100) based on a magnetorheological fluid illustrated in FIG. 1.

[0028] Referring to FIGS. 1 and 2, an improved T-shaped rotor type haptic actuator (100) based on a magnetorheological fluid according to one embodiment of the present invention is largely configured to include an actuator housing (110), an actuator housing cover (120), a rotating part (130), an MR fluid (140), a solenoid coil (150), and a magnetic induction ring (160).

[0029] The actuator housing (110) accommodates a rotating part (130), MR fluid (140), solenoid coil (150), and magnetic induction ring (160) inside, and the inner shape is formed with an engraved shape corresponding to the shape of the rotating part (130).

[0030] The actuator housing cover (120) covers the upper side of the actuator housing (110) and serves to prevent the upper part of the actuator housing (110) from being exposed to the outside.

[0031] This actuator housing cover (120) is composed of a lower housing cover (121), an upper housing cover (122), an O-ring (123), and a bearing (124).

[0032] The lower housing cover (121) is directly connected to the upper side of the actuator housing (110), and can be fixed to the upper side of the actuator housing (110) in a fitting manner, or can be fixed in a bolt-joint manner by combining with a screw line formed along the upper inner surface of the actuator housing (110).

[0033] The lower housing cover (121) has a partially protruding structure so that a portion of the lower portion can be inserted into the actuator housing (110). In addition, a through hole (121a) is formed in the center of the lower housing cover (121) so that the rotation shaft (133) of the rotation part (130) described later penetrates upward and is exposed to the outside. In addition, since an O-ring (123) is provided in the through hole (121a), the MR fluid (140) filled in the actuator housing (110) can be prevented from leaking to the outside.

[0034] An upper housing cover (122) is attached to the upper side of the lower housing cover (121).

[0035] The upper housing cover (122) is formed in a shape corresponding to the lower housing cover (121), and has a partially protruding structure so that a portion of the lower portion is inserted into the upper side of the lower housing cover (121).

[0036] The upper housing cover (122) can be fixed by a fitting method to the upper side of the lower housing cover (121), or can be fixed by a bolt connection method by combining with a screw thread formed along the upper inner surface of the lower housing cover (121).

[0037] A through hole (122a) is formed in the center of the upper housing cover (122) so that the rotation axis (133) of the rotation part (130) penetrates upward and is exposed to the outside. This is positioned on the same vertical line as the through hole (121a) of the lower housing cover (121), and its diameter is also formed to be the same.

[0038] A bearing (124) is provided in the through hole (122a) of the upper housing cover (122). The bearing (124) is provided to penetrate the through hole (121a, 122a) and come into contact with the rotation shaft (133) of the rotation part (130) exposed (protruded) to the outside, so as to minimize friction when the rotation shaft (133) rotates at high speed.

[0039]

[0040] FIG. 3 is a drawing showing the rotating part (130) illustrated in FIG. 1 in more detail, FIG. 4 is a drawing showing the structure of the rotating shaft (132) illustrated in FIG. 3, various shapes of the rotating shaft (132) according to the number of bumps on the rotating shaft (132), and simulation results for the amount of torque resistance change according to the number of bumps, and FIG. 5 is a drawing showing the shear mode and flow mode of each of the bump and non-bump areas, and the simulation results accordingly.

[0041] Looking at FIGS. 3 to 5, the rotating part (130) is largely composed of a rotating part body (131), a rotating shaft (132), and a rotating axis (133).

[0042] The rotating body (131) is a structure accommodated in the innermost part of the actuator housing (110) and has a cylindrical shape. At this time, the rotating body (131) rotates in the space within the actuator housing (110), and MR fluid (140) is filled between the rotating body (131) and the inner wall of the actuator housing (110).

[0043] A rotating shaft (132) having a larger diameter than the rotating body (131) is provided on the upper side of the rotating body (131). The rotating shaft (132) is formed integrally with the rotating body (131) while being accommodated in the actuator housing (110), and has a structure for generating a rotational resistance force by magnetic field induction of the MR fluid (140).

[0044] More specifically, the rotating shaft (132) has a sawtooth shape with one or more bumps protruding along the edge. Here, the bumps refer to the teeth themselves, and the shape of the rotating shaft (132) itself can be formed in various ways depending on the number and angle of the bumps, as shown in FIG. 4.

[0045] When the number of bumps is 0, the edge of the rotating shaft (132) itself becomes one bump, and the bump angle is 360 degrees. When the number of bumps is 2, two bumps protrude from the edge of the rotating shaft (132) to form teeth, and the bump angle is 90 degrees. When the number of bumps is 4, four bumps protrude from the edge of the rotating shaft (132) to form teeth, and the bump angle is 45 degrees. When the number of bumps is 6, six bumps protrude from the edge of the rotating shaft (132) to form teeth, and the bump angle is 30 degrees. When the number of bumps is 8, eight bumps protrude from the edge of the rotating shaft (132) to form teeth, and the bump angle is 22.5 degrees. When the number of bumps is 10, 10 bumps protrude from the edge of the rotating shaft (132) to form teeth, and the bump angle at this time is 18 degrees.

[0046] That is, as the number of bumps increases, the bump angle is divided accordingly, and the shape in which the number of teeth of the rotating shaft (132) itself increases is shown.

[0047] At this time, looking at the simulation results of Fig. 4, it can be seen that the highest torque resistance (Nmm) is shown when the number of bumps is 6 based on the same MR fluid (140). Accordingly, in the present invention, the rotary shaft (132) can be formed with bumps having 6 bumps and each bump angle being 30 degrees.

[0048] Referring to FIG. 5, in the bump of the rotating shaft (132), the shear mode can be applied by the MR fluid (140) filled in the gap between the bump and the actuator housing (110), and in the MR fluid (140) filled in the gap between the non-bump area and the actuator housing (110), the shear mode and the flow mode are applied simultaneously by a larger space. At this time, since the MR fluid (140) has viscosity due to the magnetic field generated from the solenoid coil (150), a greater resistance occurs in the rotating shaft (132) itself, which forms a greater torque resistance.

[0049]

[0050] MR fluid (140) is an intelligent fluid that undergoes a phase change due to a magnetic field. It is composed of a base fluid such as silicone oil and magnetic particles, and is an intelligent fluid that can control the flow of the fluid according to an external magnetic field. In addition, it can be utilized in a rotating body because it has a very fast response, excellent yield stress during flow, and particularly high damping force even with a small amount of power. This MR fluid (140) becomes more viscous when a magnetic field is applied.

[0051] The yield stress of the MR fluid (140) is proportional to the magnetic flux density (B) as described in the mathematical formula below, and the magnetic flux density is proportional to the magnetic flux (Φ) formed in the magnetic circuit and inversely proportional to the magnetic surface area (A).

[0052] [Mathematical formula]

[0053] B= Φ / A

[0054] (Here, B is the magnetic flux density, Φ is the magnetic flux, and A is the magnetic surface area)

[0055]

[0056] The viscosity of the MR fluid (140) increases as a result of the magnetic field induction, and accordingly, a greater resistance is applied to the bump of the rotating shaft (132), so that the shear mode and the flow mode can be applied simultaneously.

[0057]

[0058] The solenoid coil (150) is provided in a ring shape inside the actuator housing (110) and is positioned at a distance from the rotating body (131) by the length of the magnetic induction ring (160).

[0059] When current is applied to the solenoid coil (150), a magnetic field is generated, which induces a magnetic field of the MR fluid (140) filled between the actuator housing (110) and the rotating part (130), thereby increasing viscosity and generating rotational resistance.

[0060] Meanwhile, inside the actuator housing (110), a magnetic induction ring (160) corresponding to a non-magnetic body is provided along the longitudinal direction between the solenoid coil (150) and the rotating body (131) of the rotating part (130).

[0061] Since the magnetic induction ring (160) is a non-magnetic material and is not magnetized, a magnetic field cannot be induced by itself. Therefore, the solenoid coil (150) itself can generate a larger magnetic field in the MR fluid (140), thereby inducing a larger magnetic field. Accordingly, the viscosity of the MR fluid (140) increases further, thereby enabling it to have the greatest torque resistance. This will be examined in more detail as follows.

[0062] FIG. 6 is a drawing showing a magnetic field path induced in the MR fluid (140) illustrated in FIG. 2, and FIG. 7 is a drawing showing simulation results for the magnetic field path induced in the MR fluid (140) with and without the magnetic induction ring (160) illustrated in FIG. 2, respectively.

[0063] Referring to FIGS. 6 and 7, since the magnetic induction ring (160) is a non-magnetic material in itself, it is not magnetized and thus a magnetic field cannot be induced. Therefore, when a larger magnetic field is generated in the MR fluid (140) from the solenoid coil (150) as shown in FIG. 6 to induce a larger magnetic field, the magnetic field is induced further along the longitudinal direction of the magnetic induction ring (160) along the magnetic induction ring (160). The magnetic field thus induced forms a larger torque resistance force in the rotating part (130). As shown in FIG. 7, it can be seen that the largest torque resistance force is formed when the thickness of the magnetic induction ring (160) is 1000 μm.

[0064] In addition, as shown in Fig. 7, when there is no magnetic induction ring (160), the magnetic field is induced only in the solenoid coil (150) itself, whereas when there is a magnetic induction ring (160), the magnetic field is induced more strongly along the magnetic induction ring (160).

[0065]

[0066] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. Actuator housing (110); An actuator housing cover (120) covering the upper side of the actuator housing (110); A rotating part (130) accommodated within the housing (110) and partially exposed to the outside through the actuator housing cover (120), and configured to be rotatable within the housing (110); An MR fluid (140) provided inside the actuator housing (110) and filled between the inner wall of the actuator housing (110) and the rotating part (130); A solenoid coil (150) provided in a ring shape inside the above actuator housing (110); and It is characterized by including a magnetic induction ring (160) which is provided in a ring shape inside the actuator housing (110) and is positioned between the solenoid coil (150) and the rotating part (130). An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

2. In paragraph 1, The above actuator housing cover (120) is A lower housing cover (121) connected to the actuator housing (110) and having a through hole (121a) formed to expose the rotating part (130) to the outside; An upper housing cover (122) connected to the upper side of the lower housing cover (121) and having a through hole (122a) formed therein for exposing the rotating part (130) to the outside; An O-ring (123) provided in the above through hole (121a) and preventing the MR fluid (140) from leaking to the outside; and It is characterized by including a bearing (124) provided in the above through hole (122a) and preventing friction with the rotating part (130). An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

3. In paragraph 2, The above rotating part (130) is A cylindrical rotating body (131) accommodated inside the above actuator housing (110); A rotary shaft (132) that is accommodated inside the actuator housing (110) and is integrally formed to have a diameter larger than that of the rotary body (131) on the upper side of the rotary body (131); and It is characterized by including a rotation shaft (133) formed integrally on the upper side of the above rotation shaft (132) and protruding outward through the through hole (121a, 122a). An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

4. In paragraph 3, The above rotating shaft (132) is characterized by having a sawtooth shape with one or more bumps protruding along the edge perimeter; An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

5. In paragraph 1, The above magnetic induction ring (160) is characterized by being a non-magnetic material. An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

6. In paragraph 1, The above rotation axis (133) is Characterized by its hexagonal prism shape, An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

7. In paragraph 2, Between the above through hole (122a) and the bearing (124), Characterized by the application of grease to prevent frictional heat, An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

8. In paragraph 3, On the lower inner side of the above actuator housing (110), It is characterized in that a rotational axis is provided that is inserted inwardly from the lower part of the above-mentioned rotational body (131). An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

9. In paragraph 4, The above bump is, Characterized in that it is formed in an even number along the edge circumference of the above rotating shaft (132). An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

10. In paragraph 4, A shear mode is formed in the gap between the actuator housing (110) and the bump. It is characterized in that the shear mode and the flow mode are formed simultaneously in the gap between the actuator housing (110) and the edge of the rotary shaft (132) where the bump is not formed. An improved T-shaped rotor-type haptic actuator based on magnetorheological fluids.

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