Magneto-rheological auxiliary steering mechanism

Abstract

The invention discloses a magneto-rheological auxiliary steering mechanism, and belongs to the technical field of automobile steering. Comprising a steering motor and a magneto-rheological damper, the steering motor is connected with the magneto-rheological damper in series, a motor outer shell of the steering motor is fixedly connected with a damper outer shell of the magneto-rheological damper, and a motor shaft of the steering motor is fixedly connected with a damper shaft of the magneto-rheological damper. The damper inner shell is rotationally installed on the periphery of the damper shaft through the two bearings. The steering motor and the magneto-rheological damper form a magneto-rheological auxiliary steering mechanism which is compact in structure and efficient, the structural compactness and integration degree of the vehicle corner module are improved, the space, occupied by the corner module assembly, of a steering system is reduced, and therefore more arrangement space is provided for other structures of a vehicle. In addition, the mechanism can be widely applied to various automobiles by being matched with different rotary magnetorheological dampers, the driving safety and comfort can be remarkably improved, and the requirements of different drivers are met.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive steering, and particularly to a magnetorheological assisted steering mechanism. Background Art

[0002] Automobile steering safety is an important part of the overall safety performance of a vehicle, which is directly related to the driver's control ability and driving stability of the vehicle. A good steering system can ensure precise control of the vehicle under various driving conditions, enhance driving confidence, and reduce the risk of accidents. Modern automobiles generally adopt an electric power steering (EPS) system. This technology provides assistance through an electric motor, which not only improves the steering sensitivity and comfort, but also can adjust the assistance magnitude in real time according to the vehicle speed and driving conditions, thereby enhancing safety. In addition, the design of the steering system must also consider the transmission of steering feedback and road feel. The steering system should be able to effectively feedback the road surface conditions to the driver so that he can make timely responses and avoid accidents caused by losing control of the vehicle driving state. With the development of autonomous driving technology, the concept of steering safety is also constantly evolving.

[0003] Traditional electric power steering systems are prone to cause the vehicle to skid or lose control in extreme steering conditions, which requires the vehicle's steering system to have higher reliability and redundant design to ensure safety in various complex situations. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a magnetorheological assisted steering mechanism, in which a steering motor and a magnetorheological damper are connected in series. Compared with traditional electric power steering systems, the steering mechanism in the present invention can change the damping force, making the steering response faster, the overshoot angle of steering lower, the energy consumption required lower, and at the same time improving the structural compactness and integration of the steering mechanism angle module, having better market prospects.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A magnetorheological assisted steering mechanism, comprising:

[0007] A steering motor, the steering motor includes a motor main body, a motor shaft and a motor housing, the motor main body is fixedly arranged in the motor housing, and the motor shaft is rotatably inserted into the motor main body;

[0008] Magnetorheological damper, the magnetorheological damper includes a damper inner housing, a stator-rotor module, a damper shaft, an excitation coil and a damper outer housing. The damper shaft is rotatably arranged in the damper inner housing. The stator-rotor module is arranged between the damper inner housing and the damper outer housing. A chamber for accommodating magnetorheological fluid is formed between the stator-rotor module and the damper inner housing. The excitation coil is sleeved on the top end of the damper inner housing;

[0009] Wherein, the top end of the motor shaft is fixedly connected to the bottom end of the damper shaft through a coupling, and the motor outer housing is fixedly connected to the damper outer housing.

[0010] As a further scheme of the present invention: the stator-rotor module includes end gaskets, an outer rotor, a stator and an inner rotor. The end gaskets are fixedly sleeved on the upper and lower ends of the damper inner housing respectively. The outer rotor, the stator and the inner rotor are sequentially arranged at intervals from outside to inside between the two end gaskets. The outer rotor and the inner rotor are fixedly connected to the damper shaft through rotor gaskets and screws.

[0011] As a further scheme of the present invention: the damper inner housing, the outer rotor, the stator and the inner rotor together form four chambers connected by magnetorheological fluid.

[0012] As a further scheme of the present invention: the stator-rotor module further includes a first annular seal ring, and the first annular seal ring is arranged between the end gasket and the damper inner housing to achieve static sealing between the end gasket and the damper inner housing.

[0013] As a further scheme of the present invention: the stator-rotor module further includes a second annular seal ring, and the second annular seal ring is arranged between the end gasket and the damper outer housing to achieve static sealing between the end gasket and the damper outer housing.

[0014] As a further scheme of the present invention: the stator-rotor module further includes a third annular seal ring, and the third annular seal ring is arranged between the damper inner housing and the damper shaft to achieve dynamic sealing between the damper inner housing and the damper shaft.

[0015] As a further scheme of the present invention: the magnetorheological damper further includes end covers, and the end covers are fixedly installed at the top end and the bottom end of the damper outer housing respectively.

[0016] As a further scheme of the present invention: a protective housing is fixedly connected between the end cover at the bottom end of the damper outer housing and the top end of the motor outer housing.

[0017] As a further solution of the present invention: the motor housing is made of a magnetic isolation material; the damper housing and the damper inner housing are made of a magnetic conductive material.

[0018] As a further solution of the present invention: the damper inner housing is rotatably mounted on the outer periphery of the damper shaft through two bearings.

[0019] Advantages of the present invention:

[0020] When the magnetorheological assist steering mechanism works in the active resistance mode, the semi-active controlled magnetorheological damper can achieve a very large damping coefficient with extremely low power consumption, and the active resistance required from the steering motor is extremely small or the steering motor does not need to work. Therefore, compared with an electric power steering (EPS) system (where the resistance is entirely generated by the active force of the steering motor), it has lower energy consumption.

[0021] Since most of the damping force for steering overshoot can be provided by the magnetorheological damper, the requirement for the rated force of the steering motor is significantly reduced compared with the electric power steering system, and the cost of the steering motor is significantly reduced.

[0022] The steering motor and the magnetorheological damper are concentrically and serially arranged. On the basis of ensuring the steering function, it can improve the overall structural integration and structural compactness of the steering system, optimize the structural space of the steering system, and improve the structural compactness and integration of the corner module.

[0023] It has failure safety. When the steering motor fails partially, the magnetorheological damper can still work normally, avoiding extreme steering of the vehicle and providing better safety.

[0024] In summary, in the present invention, the steering motor and the magnetorheological damper together constitute a structurally compact and efficient magnetorheological assist steering mechanism, which improves the structural compactness and integration of the vehicle corner module, reduces the space occupied by the corner module components in the steering system, and thus provides more layout space for other structures of the vehicle. Moreover, this mechanism can be widely applied to various automobiles by matching different rotary magnetorheological dampers, and can also significantly improve the driving safety and comfort, meeting the needs of different drivers. Description of the Drawings

[0025] The present invention will be further described below with reference to the drawings.

[0026] Figure 1 is a schematic diagram of the internal structure of a magnetorheological assist steering mechanism of the present invention;

[0027] Figure 2 is a schematic diagram of the internal structure of the magnetorheological damper of the present invention;

[0028] Figure 3 isFigure 2 Schematic enlarged view of the structure at position A in

[0029] Figure 4 is Figure 2 Schematic enlarged view of the structure at position B in

[0030] In the figure: 1. Steering motor; 11. Motor main body; 12. Motor shaft; 13. Motor housing; 2. Magnetorheological damper; 21. Damper inner housing; 22. Stator-rotor module; 221. End gasket; 222. External rotor; 223. Stator; 224. Inner rotor; 225. First annular sealing ring; 226. Second annular sealing ring; 227. Third annular sealing ring; 228. Rotor gasket; 23. Damper shaft; 24. Excitation coil; 25. Damper housing; 26. End cover; 27. Bearing; 3. Protection housing; 4. Coupling. Specific embodiments

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, specific orientation structure and operation. Therefore, it should not be construed as a limitation of the present invention.

[0033] In addition, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0034] Please refer to Figures 1-4 As shown, the embodiment of the present invention provides a magnetorheological assisted steering mechanism, which is applicable to a corner module. The corner module is provided with a vehicle body mounting portion and a steering system mounting portion. The vehicle body mounting portion is suitable for connecting to the vehicle body to reduce the space occupied by the steering system.

[0035] Please refer to Figure 1As shown in the figure, the magnetorheological assisted steering mechanism includes a steering motor 1 and a magnetorheological damper 2. Among them, the steering motor 1 includes a motor main body 11, a motor shaft 12 and a motor housing 13. The magnetorheological damper 2 includes a damper inner housing 21, a stator-rotor module 22, a damper shaft 23, an excitation coil 24 and a damper housing 25. The steering motor 1 is connected in series with the magnetorheological damper 2. The motor housing 13 of the steering motor 1 is fixedly connected to the damper housing 25 of the magnetorheological damper 2. The motor shaft 12 of the steering motor 1 is fixedly connected to the damper shaft 23 of the magnetorheological damper 2. The damper inner housing 21 is rotatably mounted on the outer periphery of the damper shaft 23 through two bearings 27.

[0036] The motor main body 11 is fixedly arranged inside the motor housing 13. The motor main body 11 provides power to drive the steering mechanism to rotate, so that the wheels can rotate. The motor shaft 12 can rotatably pass through the motor main body 11 and is connected to the damper shaft 23 through a coupling 4 at one end, and is connected to the controller at the other end. The active steering force provided by the steering motor 1 acts on the damper shaft 23 through the coupling 4. The damper shaft 23 is rotatably arranged inside the damper inner housing 21. The stator-rotor module 22 is arranged between the damper inner housing 21 and the damper housing 25. A chamber for accommodating magnetorheological fluid is formed between the stator-rotor module 22 and the damper inner housing 21. The excitation coil 24 is sleeved on the top of the damper inner housing 21. The magnetic field intensity generated by the excitation coil 24 at the annular flow channel can be changed by changing the magnitude of the applied current. The magnetorheological fluid will change its viscosity with the strength of the magnetic field, and then change the damping coefficient of the magnetorheological damper 2.

[0037] The active steering force provided by the steering motor 1 acts on the damper shaft 23 through the coupling 4. When this force is the same as the force provided by the steering wheel rotation direction, this force can be transmitted to the wheels through the magnetorheological damper 2 in real time. At this time, the magnetorheological damper 2 reduces the damping to the lowest level, improving the steering response rate; when this force is opposite to the force provided by the steering wheel rotation direction, the magnetorheological damper 2 outputs a large damping force, improving the energy dissipation efficiency and making the steering return more stable.

[0038] When the active steering force provided by the steering motor 1 is opposite to the force generated by the steering wheel rotation, most of the force required for steering can be provided by the magnetorheological damper 2 at this time. At this time, the steering motor 1 only needs to provide a small force. The magnetorheological damper 2 can achieve a large damping force with extremely low power, so the energy consumption in this working condition is significantly reduced compared with the traditional steering mechanism; only when the active steering force provided by the steering motor 1 is the same as the force generated by the steering wheel rotation, the required steering force is only provided by the steering motor 1 at this time. To reduce the motor energy consumption in this working condition, the damping coefficient of the magnetorheological damper 2 is adjusted to the lowest level at this time, reducing the resistance opposite to the active steering to the minimum.

[0039] It should be noted that the motor housing 13 is made of a magnetic shielding material, and the damper housing 25 and the damper inner housing 21 are made of a magnetic conductive material. This combination of magnetic shielding material and magnetic conductive material can effectively isolate the influence of the external magnetic field on the magnetorheological fluid inside the magnetorheological damper 2. At the same time, a closed-loop magnetic field is formed under the action of the current inside, effectively avoiding the leakage of the internal magnetic field and improving the magnetic field action efficiency.

[0040] Please refer to Figure 2 As shown, end caps 26 are respectively fixedly installed at the top and bottom of the damper housing 25 through long screws. Please refer to Figure 1 As shown, a protective housing 3 is fixedly connected between the end cap 26 at the bottom of the damper housing 25 and the top of the motor housing 13.

[0041] Please refer to Figure 2 As shown, in one embodiment, the stator-rotor module 22 includes end shims 221, an outer rotor 222, a stator 223, and an inner rotor 224. End shims 221 are respectively fixedly sleeved at the upper and lower ends of the damper inner housing 21. The outer rotor 222, the stator 223, and the inner rotor 224 are sequentially arranged at intervals between the two end shims 221 from outside to inside. The outer rotor 222 and the inner rotor 224 are fixedly connected to the damper shaft 23 through rotor shims 228 and screws. The rotation of the damper shaft 23 drives the rotation of the outer rotor 222 and the inner rotor 224. The damper inner housing 21, the outer rotor 222, the stator 223, and the inner rotor 224 together form four chambers connected by the magnetorheological fluid. The chambers are used as accommodation spaces for the magnetorheological fluid. The rotation of the outer rotor 222 and the inner rotor 224 drives the magnetorheological fluid to generate a damping force. The magnetic field strength generated by the excitation coil 24 at the annular flow path can be changed by changing the magnitude of the current applied to the excitation coil 24. The magnetorheological fluid will change its viscosity with the strength of the magnetic field, thereby changing the damping coefficient of the magnetorheological damper 2.

[0042] Furthermore, in some embodiments, the stator-rotor module 22 further includes a first annular sealing ring 225, a second annular sealing ring 226, and a third annular sealing ring 227. Please combine Figure 2 and Figure 3 As shown, the first annular sealing ring 225 is arranged between the end shim 221 and the damper inner housing 21 to achieve static sealing between the end shim 221 and the damper inner housing 21. Please combine Figure 2 and Figure 4 As shown, the second annular sealing ring 226 is arranged between the end shim 221 and the damper housing 25 to achieve static sealing between the end shim 221 and the damper housing 25. Please refer to Figure 2As shown, a third annular sealing ring 227 is disposed between the damper inner housing 21 and the damper shaft 23 to achieve dynamic sealing between the damper inner housing 21 and the damper shaft 23.

[0043] The magnetorheological assist steering mechanism has three working modes: active thrust mode, active resistance mode, and resistance-then-thrust mode.

[0044] Active thrust mode: When the torque required by the magnetorheological assist steering mechanism is in the same direction as the rotation direction, the force required at this time is only provided by the steering motor 1. To reduce the motor energy consumption under this condition, the damping coefficient of the magnetorheological damper 2 is adjusted to the lowest at this time, so that the resistance in the direction opposite to the steering direction is reduced to the minimum.

[0045] Active resistance mode: When the torque required by the magnetorheological assist steering mechanism is in the opposite direction to the rotation direction, the force required at this time is preferentially provided by the magnetorheological damper 2. When the damping force output by the magnetorheological damper 2 cannot meet the demand, the steering motor 1 is used to provide additional force. At this time, the steering motor 1 only needs to provide a very small force or does not work. Since the magnetorheological damper 2 can achieve a large damping force with a very small power, the power consumption under this condition is significantly reduced compared with the traditional planetary gear drive.

[0046] Resistance-then-thrust mode: When the actual steering angle is about to be greater than the predetermined steering angle, the magnetorheological damper 2 outputs a large damping force to reduce the overshoot angle during the vehicle steering process. When the actual steering angle has been greater than the predetermined steering angle, the damping coefficient of the magnetorheological damper 2 is adjusted to the lowest at this time, so as to improve the steering response speed. The working switch of the magnetorheological damper 2 can reduce the torque output of the steering motor 1, thereby reducing the energy consumption of the vehicle during the steering process.

[0047] In summary, the combination of the steering motor 1 and the magnetorheological damper 2 provided by the present invention can achieve a damping coefficient and damping force that are adjustable in real time. During the driving of the vehicle, when the wheels do not need to be steered, the magnetorheological damper 2 can be used to maintain the steering of the wheels at this time while the steering motor 1 does not work. Compared with the current situation where the motor of the steering gear needs to continuously output torque to maintain the wheel direction, the present invention can greatly reduce the energy loss of the motor. During the vehicle steering process, the damping coefficient can be flexibly adjusted and maintained near the critical coefficient, thereby providing better handling performance. Especially during the high-speed driving of the vehicle, the required steering torque increases. If the magnetorheological damper 2 is not added, there will be a situation where the steering torque provided by the steering motor 1 is insufficient and the energy consumption is too large. Since most of the damping force can be provided by the magnetorheological damper 2, the steering motor 1 only needs to output a part of the force, and the power consumption of the magnetorheological damper 2 is much lower than that of the motor, resulting in a significant reduction in the overall energy consumption. In addition, the magnetorheological damper 2 can adjust the damping coefficient in real time, effectively reducing the overshoot of the steering and improving the response speed of the steering return. This ability of instant adjustment enables the vehicle to maintain excellent handling stability under different driving conditions.

[0048] The above has described the preferred embodiments of the present invention in detail and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the present invention application shall still fall within the scope covered by the patent of the present invention.

Claims

1. A magnetorheological assisted steering mechanism, suitable for a corner module, characterized in that: include: A steering motor (1), the steering motor (1) comprising a motor body (11), a motor shaft (12) and a motor outer shell (13), the motor body (11) being fixedly arranged in the motor outer shell (13), and the motor shaft (12) being rotatably inserted in the motor body (11); A magnetorheological damper (2), the magnetorheological damper (2) comprising a damper inner shell (21), a stator-rotor module (22), a damper shaft (23), an excitation coil (24) and a damper outer shell (25), the damper shaft (23) being rotatably disposed in the damper inner shell (21), the stator-rotor module (22) being disposed between the damper inner shell (21) and the damper outer shell (25), a chamber for accommodating a magnetorheological fluid being formed between the stator-rotor module (22) and the damper inner shell (21), and the excitation coil (24) being sleeved on the top of the damper inner shell (21); The top end of the motor shaft (12) is fixedly connected to the bottom end of the damper shaft (23) via a coupling (4), and the motor outer shell (13) is fixedly connected to the damper outer shell (25).

2. A magnetorheological assisted steering mechanism according to claim 1, characterized in that: The stator-rotor module (22) comprises an end gasket (221), an external rotor (222), a stator (223) and an internal rotor (224); the end gaskets (221) are fixedly sleeved at the upper and lower ends of the damper inner housing (21); the external rotor (222), the stator (223) and the internal rotor (224) are sequentially arranged between the two end gaskets (221) from the outside to the inside; the external rotor (222) and the internal rotor (224) are fixedly connected to the damper shaft (23) via rotor gaskets (228) and screws.

3. A magnetorheological assisted steering mechanism according to claim 2, characterized in that: The damper inner housing (21), the outer rotor (222), the stator (223) and the inner rotor (224) together form four chambers connected by magnetorheological fluid.

4. A magnetorheological assisted steering mechanism according to claim 3, characterized in that: The stator-rotor module (22) further comprises a first annular sealing ring (225), wherein the first annular sealing ring (225) is arranged between the end gasket (221) and the damper inner housing (21), so as to achieve static sealing between the end gasket (221) and the damper inner housing (21).

5. A magnetorheological assisted steering mechanism according to claim 4, characterized in that: The stator-rotor module (22) further comprises a second annular sealing ring (226), which is arranged between the end gasket (221) and the damper outer shell (25) to achieve static sealing between the end gasket (221) and the damper outer shell (25).

6. A magnetorheological assisted steering mechanism according to claim 5, characterized in that: The stator-rotor module (22) further comprises a third annular sealing ring (227), wherein the third annular sealing ring (227) is arranged between the damper inner housing (21) and the damper shaft (23) to achieve dynamic sealing between the damper inner housing (21) and the damper shaft (23).

7. The magnetorheological assisted steering mechanism according to claim 1, characterized in that: The magnetorheological damper (2) further comprises an end cover (26), and the end cover (26) is fixedly mounted on the top and bottom ends of the damper outer shell (25), respectively.

8. A magnetorheological assisted steering mechanism according to claim 7, characterized in that: A protective housing (3) is fixedly connected between the end cover (26) at the bottom end of the damper outer housing (25) and the top end of the motor outer housing (13).

9. The magnetorheological assisted steering mechanism according to claim 1, characterized in that: The motor outer shell (13) is made of magnetic isolation material; the damper outer shell (25) and the damper inner shell (21) are made of magnetic conductive material.

10. The magnetorheological assisted steering mechanism according to claim 1, characterized in that: The damper inner housing (21) is rotatably mounted on the outer periphery of the damper shaft (23) via two bearings (27).

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