Steer-by-wire steering device and vehicle

Abstract

Steer-by-wire steering device (10; 10A; 10B; 10C) comprising: a first element (80, 80B, 80C) that rotates together with an input shaft (21) when a steering wheel (11) is turned, and that includes a first projection (82, 82B, 82C) that extends from the input shaft (21) in a radial direction; a second element (90, 90A) provided on the input shaft (21), having a center of mass (G2) spaced relative to the center line (CL) of the input shaft (21) and a second projection (92) that extends into a path of movement of the first projection (82, 82B, 82C), wherein the second element (90) is rotatable together with the first element (80, 80B, 80C) when the first projection (82, 82B, 82C) is in contact with the second projection (92); and a stop (61a) which is arranged in a position suitable for adjoining only one path of movement of the second element (90) when the second element (90) is rotated by the first element (80, 80B, 80C), and which is suitable for limiting a rotation of the steering wheel (11) by means of the input shaft (21) when the second projection (92) is in contact with it, wherein the second projection (92) comprises a radial projection (92a) extending in the radial direction from the second base (91) and an axial projection (92b) extending in the direction along the axial line (CL) from the radial projection (92a), and wherein the axial projection (92b) is able to rest against the first projection (82, 82B, 82C) and against the stop (61a).

Description

Technical field

[0001] The present invention relates to a steer-by-wire steering device that limits the rotation angle of a steering wheel. State of the art

[0002] Regarding steering devices for vehicles, etc., a steer-by-wire (electronic) system is known that has an input shaft which is rotatable together with a steering wheel and decoupled from the steered wheels. Various steering devices have been proposed that are suitable for limiting the rotation angle of the steering wheel.

[0003] DE 100 17 049 A1 discloses a steering device for a vehicle in which the power transmission from the steering spindle to the steering gear can be effected via mechanical, hydraulic, pneumatic, or electrical transmission elements. The steering spindle has axial and / or torsional stops to limit the angle of rotation in both directions. Counter-stops are arranged on the housing side.

[0004] JP 2010-126 031 A discloses a steering device for a vehicle with a reaction force generating device which increases a reaction force in a predetermined rotation angle range and limits the rotation of the steering wheel and thus the rotation angle from a predetermined rotation angle.

[0005] Another technology of such a steering device is disclosed, for example, in JP H10-194 152 A. The steering device disclosed in JP H10-194 152 A comprises an input shaft which is rotated by turning a steering wheel, a slotted element which is designed to rotate about the input shaft relative to it and which has an elongated hole which is open along the circumferential direction of the input shaft, a pin which passes completely through the elongated hole of the slotted element and which has a tip which is inserted into the input shaft, and a stop which is designed to bear against the slotted element.

[0006] When a driver turns the steering wheel, the pin rotates along with the input shaft. The slotted element does not rotate while the pin moves within the slot. As the steering wheel continues to turn, the pin moves to the end of the slot and rests against the slotted element. As the steering wheel continues to turn, the slotted element, pushed by the pin, also rotates. When the steering wheel is turned a predetermined amount, part of the slotted element reaches the stop, thus limiting the steering wheel's rotation.

[0007] The steering device limits the rotation angle of the steering wheel by the length of the elongated hole and by the position of the stop. Summary of the invention; Technical task

[0008] According to the steering device disclosed in JP H10-194152A, a portion of the slotted element protrudes to abut the stop. The center of mass of the slotted element is offset from the centerline of the input shaft by a distance corresponding to the weight of the protruding portion. Therefore, the slotted element rotates when it is not in contact with the pin, and if the stop is located in the path of this rotation, the slotted element abuts the stop. When the slotted element rotates and abuts the pin, noise can be generated.

[0009] It is an object of the present invention to provide a technology that is capable of limiting the rotation angle of a steering wheel and reducing the generation of impact noise by a rotating element. Solution to the task

[0010] This problem is solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0011] Through intensive investigations and considerations, the inventors of the present invention have gained a technical insight showing that by adjusting the position of the stop and taking into account the position of the center of mass of a rotating element, the generation of impact noise can be reduced. The present invention was made in consideration of this technical insight.

[0012] The present invention is described below. In the following description, a reference numeral is used in the accompanying figures to facilitate understanding of the present invention; however, this does not limit the scope of the present invention to the embodiments shown.

[0013] According to one embodiment, a steer-by-wire steering device is provided, which includes: a first element 80, 80B or 80C which rotates together with an input shaft 21 when a steering wheel 11 is turned, and which comprises a first projection 82, 82B or 82C which extends from the input shaft in a radial direction; a second element 90 or 90A provided on the input shaft, having a center of mass G2 spaced relative to a center line CL of the input shaft and comprising a second projection 92 that extends into a path of motion of the first projection, wherein the second element is rotatable together with the first element when the first projection is in contact with the second projection; and a stop 61a or 61a which is arranged in a position suitable to only adjoin a path of movement of the second element when the second element is rotated by the first element, and which is suitable to limit a rotation of the steering wheel by means of the input shaft when the second projection is in contact.

[0014] The first element 80 can further comprise a first base 81 that surrounds the input wave 21.

[0015] The second element 90 or 90A can further comprise a second base 91 surrounding the first base 81.

[0016] The first element 80 can further comprise a first weight 83, which aligns a center of mass G1 of the first element with the center line CL of the input wave 21.

[0017] The second element can further comprise a second base 91 surrounding the input shaft 21 and a second weight 93A provided on the second base, and the center of mass G2 of the second element can be located between the center line CL of the input shaft 21 and the second weight.

[0018] According to another embodiment, a steer-by-wire steering device is provided, which includes: a first element 80, which surrounds a first base 81, which is to be rotated when a steering wheel 11 is turned, and is rotatable together with the input shaft, and comprises a first projection 82, which projects from the first base in a radial direction or in an axial direction; a second element 90 comprising a second base 91 surrounding the first base and a second projection 92 extending from the second base and into a path of motion of the first projection 82, the second element being rotatable together with the first element when the first projection is in contact with the second projection, and a center of mass G2 of the second element being arranged between a center line of the input shaft and the second projection; and a stop 61a or 61a, which is separate from the second projection and is formed above the center line of the input shaft in a path of movement of the second projection, if the center of mass of the second element is arranged below the center line of the input shaft, and which is suitable to limit a rotation of the steering wheel by means of the input shaft when the second projection is in contact.

[0019] According to another embodiment, a steer-by-wire steering device is provided, which includes: a first element 80, comprising a first base 81, which surrounds an input shaft 21 to be rotated when a steering wheel 11 is turned, and which is rotatable together with the input shaft, and comprising a first projection 82, which projects from the first base in a radial direction or in an axial direction; a second element 90A comprising a second base 91 surrounding the first base, a second projection 92 extending from the second base and into a path of motion of the first projection, and a second weight 93A arranged to overlap a line L1 extending from the second projection and passing through a centerline CL of the input shaft, the second element being rotatable together with the first element when the first projection abuts the second projection, and a center of mass G2 of the second element being arranged between the centerline of the input shaft and a tip of the second weight; and a stop 61a or 61a, which is separate from the second projection and is formed in a path of movement of the second projection, if the center of mass of the second element is arranged below the center line of the input shaft, and which is suitable to limit a rotation of the steering wheel by means of the input shaft when the second projection is in contact.

[0020] Preferably, a vehicle includes one of the steer-by-wire steering devices described above. Advantageous effects of the invention

[0021] According to the present invention, a technology is provided which is suitable for limiting the rotation angle of a steering wheel and reducing the generation of impact noise by a rotating element. Brief description of the drawings Fig. Figure 1 is a representation showing, by way of example, a steer-by-wire steering device according to a first embodiment; Fig. 2 is a cross-sectional view of a Fig. 1 steering angle limiting device shown; Fig. 3 is an exploded view of the in Fig. 2 steering angle limiting device shown; Fig. Figure 4 is a perspective exploded view of a first element and a second element, both of which are in Fig. 2 are shown; Fig. 5 is a cross-sectional view along a line 5-5 in Fig. 2; Fig. 6A is a representation showing a state in which the first element rotates without a first projection touching a second projection. Fig. 6B is a representation showing a state until the second projection touches a stop when the first projection is abutting the second projection. Fig. 6C is a representation showing a state in which the first element is rotated clockwise, and Fig. 6D is a representation showing a state in which the first element and the second element rotate clockwise and touch the stop; Fig. Figure 7 is a representation describing a main section of a steer-by-wire steering device according to a second embodiment; Fig. 8 is a front view of a Fig. 7 second element shown; Fig. Figure 9 is a representation describing a main section of a steer-by-wire steering device according to a third embodiment; and Fig. Figure 10 is a representation describing a main section of a steer-by-wire steering device according to a fourth embodiment. Description of embodiments

[0022] Embodiments of the present invention are described below with reference to the accompanying figures. It should be noted that in the following description, the terms right and left mean the right and left sides as viewed by a person in a vehicle, and the terms front and rear mean the front and back as viewed by the direction of travel of the vehicle. Furthermore, in the figures, Fr, Rr, Le, Ri, Up, and Dn denote the front, back, left side, right side, top, and bottom as viewed by a person in the vehicle, respectively. The embodiments shown in the accompanying figures are merely examples of the present invention, and the present invention is not limited to these embodiments. First embodiment

[0023] Referring to Fig. 1 is a steer-by-wire steering device 10 (hereinafter referred to as "steering device 10") according to a first embodiment in Fig. The steering device 10 comprises a steering unit 12, in which a steering input is effected by a vehicle steering wheel 11, a rotary unit 14, which rotates a right and a left steered wheel 13 and 13, a clutch 15, which is located between the steering unit 12 and the rotary unit 14, and a control unit 16.

[0024] In a normal state, the clutch 15 is disengaged, and the steering unit 12 and the rotary unit 14 are mechanically separated. This means that, in a normal state, the corresponding ends of the steering unit 12 and the rotary unit 14 are decoupled. The steering device 10 uses an electronic (steer-by-wire, abbreviated as "SBW") system that rotates the right and left steered wheels 13 and 13 by actuating a rotary actuator 39 according to the steering input of the steering wheel 11.

[0025] In an emergency, a switching device 17 is actuated, which has received an electrical signal from the control unit 16 and causes the clutch 15 to be engaged. This results in the steering unit 12 and the rotary unit 14 being mechanically connected to each other.

[0026] The steering unit 12 comprises the steering wheel 11, which is to be operated by a driver, and an input shaft 21, which is connected to the steering wheel 11.

[0027] A steering angle limiting device 70 is provided on the input shaft 21, which limits the rotation angle of the steering wheel. The steering angle limiting device 70 is described in detail below.

[0028] The rotary unit 14 comprises an output shaft 34, which is connected to the input shaft 21 via the coupling 15, a rotary shaft 36, which is connected to the output shaft 34 via an actuating force transmission mechanism 35, a left and a right tie rod 37 and 37, which are provided at corresponding ends of the rotary shaft 36, a right and a left kingpin 38 and 38, which are connected to the right and left steering wheel 13 and 13 respectively via the respective right and left tie rod 37 and 37, and the rotary drive 39 which exerts a rotational force on the rotary shaft 36.

[0029] The actuating force transmission mechanism 35 is, for example, a rack and pinion mechanism. The rack and pinion mechanism 35 (the actuating force transmission mechanism 35) comprises a pinion 35a, which is provided on the output shaft 34, and a rack 35b, which is provided on the rotating shaft 36. The rotating shaft 36 is movable in the axial direction (a vehicle width direction).

[0030] The rotary drive 39 comprises a rotary motor 41, which generates a rotary force, and a rotary force transmission mechanism 42, which transmits the rotary force to the rotating shaft 36. The rotary force generated by the rotary motor 41 is transmitted to the rotating shaft 36 by the rotary force transmission mechanism 42. Consequently, the rotating shaft 36 moves in the transverse direction of the vehicle. The rotary motor 41 is, for example, an electric motor.

[0031] The torque transmission mechanism 42 comprises, for example, a belt drive mechanism 43 and a ball screw drive 44. The belt drive mechanism 43 comprises a driven pulley 45, which is provided on a motor shaft 41a of the torque motor 41, a follower pulley 46, which is provided on the nut of the ball screw drive 44, and a belt 47, which is tensioned between the driven pulley 45 and the follower pulley 46.

[0032] The ball screw drive 44 is a type of conversion mechanism that converts a rotary motion into a linear motion and transmits the drive force generated by the rotary motor 41 to the rotary shaft 36. It should be noted that the rotary force transmission mechanism 42 is not limited to a design that uses the belt drive mechanism 43 and the ball screw drive 44, and can, for example, use a worm gear mechanism or a rack and pinion mechanism.

[0033] The control unit 16 receives corresponding recognition signals from a steering angle sensor 51, a steering torque sensor 52, a motor rotation angle sensor 53, an output shaft rotation angle sensor 54, a vehicle speed sensor 55, a yaw rate sensor 56, an acceleration sensor 57 and various other sensors 58 and, in response to the received recognition signal, applies a current to the clutch 15, the switching device 17, the torque motor 41, as well as a reaction force motor 101 and a stop main body 112, both of which will be described in detail later.

[0034] The steering angle sensor 51 detects the steering angle of the steering wheel 11. The steering torque sensor 52 detects a steering torque generated at the input shaft 21. The motor rotation angle sensor 53 detects the rotation angle of the reaction force motor 101. The output shaft rotation angle sensor 54 detects the rotation angle of the output shaft 34, which has the pinion 35a. The vehicle speed sensor 55 detects the vehicle's speed. The yaw rate sensor 56 detects a yaw rate (angular velocity of the yaw movement). The acceleration sensor 57 detects the vehicle's acceleration. The various other sensors 58 include a rotation angle sensor that detects the rotation angle of the rotary force motor 41. The rotation angle sensor is, for example, formed by a rotary encoder provided on the rotary force motor 41.

[0035] Fig. Figure 2 shows a cross-sectional view of the structure around the input shaft 21. The input shaft 21 runs completely through a housing 61 and is supported by the housing 61 in such a way that it is freely rotatable by means of the ball bearings 62 and 63. The steering angle limiting device 70 is housed in the housing 61. The housing 61 is provided with a recess 61b that prevents the ball bearing 62 from entering the recess. Fig. 2 is solved in a downward direction.

[0036] The housing 61 can be made of any material.

[0037] The nut 64 is attached to the input shaft 21. The nut 64 is designed to rest against the inner ring of the ball bearing 62 and limits the movement of the input shaft 21 to the right in the figure.

[0038] The ball bearings 62 and 63, for example, are prevented from being detached from the housing 61 by C-rings 65 and 66, each of which is in the shape of the letter C.

[0039] Referring to Fig. 3 The steering angle limiting device 70 comprises a first element 80, which is attached to the input shaft 21 and which is rotatable together with the input shaft 21, a first and a second bearing 72 and 73, which are provided on the outer circumference of the first element 80 and which are each formed from a metal ring, a second element 90, which is arranged on the outer circumference of the first element 80 by means of the first and the second bearings 72 and 73, a stop 61a, which is provided in the path of movement of the second element 90 and which is formed by a part of the housing 61, a third bearing 75, which is formed by a metal ring which is suitable for bearing against the first element 80 and on the second element 90, a reaction force-applying mechanism 100, which is arranged next to the third bearing 75 and which exerts a torque in a direction opposite to the rotation of the input shaft 21, and a stop 110 at any angle,which is arranged next to the reaction force-generating mechanism 100 and which stops the rotation of the input shaft 21 at any angle.

[0040] Referring to Fig. 2 and on Fig. 4 The first element 80 comprises a first base 81 which is attached to the input shaft 21 and which is rotatable together with such an input shaft, a first projection 82 which extends in the radial direction from the first base 81, and a first weight 83 which is integrally provided with the first base 81.

[0041] Regarding the material of the first element 80, any material can be selected, such as a high-stiffness material like metal or ceramic, or an elastic material like rubber or elastic resin. Regarding the material of the first weight 83, a different material from those of the first base 81 and the first projection 82 can be used. The first element 80 can be cast by two-color casting or overmolding.

[0042] If the steering angle limiting device 70 is formed and one end of the other element, which can be displaced in the axial direction along the input shaft 21, rests against another component that cannot be displaced in the axial direction, one end of the first base 81, which is parallel in the axial direction to an axis of rotation CL of the first element 80, can be configured such that it rests against the other end of such a component.

[0043] Furthermore, if two other components, arranged at corresponding ends in the axial direction parallel to the axis of rotation CL of the first element and forming the steering angle limiting device 70, can be displaced in the axial direction along the input shaft 21, the maximum distance between these two other components and the length of the first base 82 in the axial direction can be designed to be congruent with each other.

[0044] Such a design prevents the other elements 62 and 75 from being displaced axially, thus eliminating the need for a component to prevent play and loosening. This allows for a reduction in the number of components, etc. This is advantageous in terms of cost, etc. In other words, the first base 81 also serves as a positioning element for the other element, which forms the steering angle limiting device 70.

[0045] For example, in Fig. As shown in Figure 2, a design is used in which the lower end of the first base 81, which is parallel to the axis of rotation of the first element 80 in the figure, rests against an upper end of the ball bearing 62 when the lower end of the ball bearing 62 rests against the housing recess 61b. This prevents the ball bearing 62 from being displaced in the axial direction, thus preventing play and loosening.

[0046] For example, in Fig. As further shown in Figure 2, a setup is used in which the upper end of the first base 81, parallel to the axis of rotation of the first element 80 in the figure, rests against the lower end of the third bearing 75 when the upper end of the third bearing 75 abuts the worm 102a, which is pressed onto and attached to the input shaft. This prevents the third bearing 75 from being displaced in the axial direction, thus eliminating any play in the third bearing 75. This allows the third bearing 75 to have a large dimensional tolerance of the inner diameter relative to the outer diameter of the input shaft 21.

[0047] The first projection 82 can further comprise an annular section 82a, which is formed annularly along the outer circumference of the first base 81. In this case, the term radial direction means a direction extending radially around the axial line CL of the input shaft 21.

[0048] The annular section 82a is formed along the entire outer circumference of the first base 81. This prevents the first bearing 72, the second bearing 73, and the second element 90 from becoming loose and having play.

[0049] Referring to Fig. 4 and Fig. In section 5, the first weight 83 is formed transversely to the centerline CL at a location opposite the first projection 82. In other words, the first weight 83 is arranged such that it overlaps a line L1 extending from the first projection 82 and passing through the centerline CL of the input shaft 21 when the first element 80 is viewed from the front. The first weight 83 is integral with the first base 81 along its outer circumference, forming a single component with it. A center of mass G1 of the first element 80 is set by the first weight 83 such that it coincides with the centerline CL of the input shaft 21.

[0050] According to the steering angle limiting device of this embodiment, this prevents the first projection 82 from being attracted by gravity and rotated independently of the angle of the first element 80. The steering wheel can therefore be turned at will. In other words, the steering wheel is only turned by an external force, such as the driving action of the driver, and the probability of the first projection 82 being attracted by gravity and rotated together with the input shaft and the steering wheel is reduced.

[0051] It should be noted that the term "correspondence of the center of mass" covers all areas that achieve the advantageous effect for solving the problem described above and that cause the steering wheel to be turned at will.

[0052] The second element 90 comprises a second base 91 with an essentially ring-shaped form that surrounds the first base 81, and a second projection 92 that extends from the second base 91 and into the path of movement of the first projection 82. A feature such as the second projection 92 being positioned above the path of movement of the first projection 82 will be described in detail later. The second element 90 is positioned between the two ends of the first base 81.

[0053] The center of mass G2 of the second element 90 is located at a point that is as much closer to the second projection 92 than to the center line CL of the input wave 21 as the second projection 92 protrudes from the annular second base 91. That is, the center of mass G2 of the second element 90 is spaced relative to the center line CL of the input wave 21.

[0054] Regarding the material of the second element 90, any material can be selected, such as a metal, a rubber or a resin.

[0055] The second projection 92 comprises a radial projection 92a, which extends in the radial direction from the second base 91, and an axial projection 92b, which extends in the direction along the axial line CL from the radial projection 92a.

[0056] Although a mounting section 82b and the axial projection 92b can have any shape, it is preferred that they are formed in a substantially trapezoidal shape and have corresponding sections corresponding to the inclined sides of the respective trapezoid, which are directed in the same direction to ensure a large contact area between them.

[0057] Referring to Fig. 2 The reaction force generating mechanism 100 comprises a reaction force motor 101 (a motor 101) through which a current flow is generated according to the torque of the input shaft 21, and a reaction force transmission mechanism 102 which transmits a steering reaction force to the input shaft 21.

[0058] The reaction force motor 101, for example, is an electric motor. The control unit 16 supplies the current to the reaction force motor 101 and operates such a motor.

[0059] The reaction force transmission mechanism 102 is a worm gear mechanism. The reaction force transmission mechanism 102 comprises a worm 102a, which is provided on a motor shaft 101a of the reaction force motor 101, and a worm wheel 102b, which meshes with the worm 102a, is provided on the input shaft 21, and rotates along with the rotation of the worm 102a. The steering reaction force generated by the reaction force motor 101 is applied to the input shaft 21 via the reaction force transmission mechanism 102.

[0060] The reaction force-generating mechanism 100 provides the driver with a steering sensation by generating the steering reaction force against the steering force of the steering wheel 11 applied by the driver.

[0061] Also with reference to Fig. 1 is the stop 110 of any angle suitable for the steering range of the steering wheel 11 (see Fig. 1) to be changed as needed according to the vehicle's driving condition and the state of the steering device. For example, if the load on the rotary unit 14 becomes greater than or equal to a predetermined load (i.e., overload) that has been predefined, the stop 110 limits the steering range of the steering wheel 11 to any angle. More precisely, it limits the rotation of the steering wheel 11.

[0062] If the steered wheel 13 becomes stuck or encounters an obstacle, such as a curb, the control unit 16, according to conventional technologies, causes the clutch 15 to engage or the reaction force-generating mechanism 100 to generate a reaction force that prevents the driver from turning the steering wheel, thus allowing the driver to perceive such an event. Since the rotary unit 14, the clutch 15, and the reaction force-generating mechanism 100 must therefore possess a strength capable of withstanding high loads, these components are necessarily large in size.

[0063] In contrast, the stop 110, according to this embodiment, which has received the control signal from the control unit 16, limits the steering range in such a way that increasing rotational actuation of the steering wheel 11 is interrupted. Consequently, no large load is exerted on the clutch 15 and the reaction force-applying mechanism 100. This allows for a reduction in the size of the clutch 15 and the reaction force-applying mechanism 100.

[0064] The stop 110 of any angle comprises a ratchet wheel 111 which rotates together with the input shaft 21, and the stop main body 112 which is provided such that it is movable forwards or backwards relative to the ratchet wheel 111 and which is suitable to touch the ratchet wheel 111 by a forward movement.

[0065] The stop body 112 is a solenoid attached to the housing 61. In response to the electrical signal from the control unit 16, the stop body 112 causes a rod 112a to move forward towards the ratchet wheel 111. The contact of the rod 112a with the ratchet wheel 111 limits the rotation of the input shaft 21.

[0066] Next, the sequence of actions of the present invention will be described.

[0067] Referring to Fig. 6A the input shaft 21 and the first element 80 are also rotated in a counterclockwise direction when the steering wheel 11 (see Fig. 1) is rotated counterclockwise. In the state shown in the figure, the first projection 82 is not in contact with the second projection 92. If the first projection 82 is not in contact with the second projection 92, the second element 90 does not rotate. That is, the input shaft 21 and the first element 80 rotate without engaging with the second element 90 when the first projection 82 is not in contact with the second projection 92.

[0068] Referring also to Fig. 6B is the second projection 92 arranged in the path of motion of the first projection 82. The first projection 82 therefore ejects from the position in the steering wheel 11 when the steering wheel is turned. Fig. 6A state shown at the second projection 92 ( Fig. 6B). The second projection 92 is pushed by the first projection 82 by further rotating the steering wheel 11 from this state. Consequently, the second element 90 rotates together with the first element 80.

[0069] A further turn of the steering wheel 11 causes the second projection 92 to touch the stop 61a (see dashed lines in Fig. 6B). The contact of the stop 61a by the second projection 92 limits the rotation of the steering wheel 11.

[0070] Referring to Fig. 6B and Fig. 6C will turn the steering wheel 11 out of the state that is in Fig. 6B, indicated by the dashed lines, is rotated clockwise. This causes the first projection 82 to detach from the second projection 92, allowing only the first element 80 to rotate. By continuously rotating the steering wheel 11, as shown in Fig. As shown in Figure 6C, the first projection 82 abuts the second projection 92 in a lower part of the same.

[0071] Referring to Fig. 6C and Fig. 6D, the second projection 92 is pushed by the first projection 82 when the steering wheel 11 is turned further. Consequently, the second element 90 rotates together with the first element 80.

[0072] A further turn of the steering wheel 11 causes the second projection 92 to touch the stop 61a (see Fig. 6D). The contact of the stop 61a by the second projection 92 limits the rotation of the steering wheel 11.

[0073] The steering device 10 according to the first embodiment can be summarized as follows.

[0074] Referring to Fig. 1 and Fig. 5 includes the steering device 10: the first element 80, which includes the first base 81, which surrounds the input shaft 21 to be rotated when the steering wheel 11 is turned, and which is rotatable together with the input shaft, as well as the first projection 82, which projects from the first base 81 in the radial direction or in the axial direction; the second element 90, comprising the second base 91, which surrounds the first base 81, and the second projection 92, which extends from the second base 91 and into the path of motion of the first projection 82, wherein the second element is rotatable together with the first element 80 when the first projection 82 is in contact with the second projection 92, and wherein the center of mass G2 is arranged between the center line CL of the input shaft 21 and the second projection 92; and the stops 61a and 61a, which are separated from the second projection 92 and are formed above the center line CL of the input shaft 21 in the path of movement of the second projection 92, when the center of mass G2 of the second element 90 is arranged below the center line CL of the input shaft 21, and which are suitable to limit the rotation of the steering wheel 11 by means of the input shaft 21 when the second projection 92 is in contact.

[0075] The center of mass G2 of the second element 90 is spaced relative to the center line CL of the input shaft 21. Therefore, the second element 90 can rotate relative to the input shaft 21 due to adverse effects, such as vibrations during vehicle operation. According to the steering device 10, the stops 61a and 61a are located above the center line CL of the input shaft 21 within the path of movement of the second projection 92. This means that they are positioned such that they only adjoin the path of movement of the second projection 92 when the second element 90 is rotated by the first element 80. When the second element 90 rotates on its own, the second projection 92 is prevented from striking either of the stops 61a and 61a. This prevents the generation of impact noises if the second projection 92 were to strike either of the stops 61a and 61a., that the rotation angle of the steering wheel 11 can be limited and that the generation of impact noise by the rotating element (the second element 90) can also be reduced.

[0076] Furthermore, the first element 80 includes the first base 81, which surrounds the input shaft 21. Since the first element 80 can be arranged to be displaceable along the input shaft 21, the assembly of the steering device 10 is simplified.

[0077] Furthermore, the second element 90 comprises the second base 91, which surrounds the first base 81. Once the second base 91 is joined to the first base 81, the first element 80 and the second element 90 can be joined to the input shaft 21. This further simplifies the assembly of the steering device 10.

[0078] Furthermore, the first element 80 includes the first weight 83, which aligns the center of mass G1 of the first element 80 with the centerline CL of the input shaft 21. When the center of mass G1 of the first element 80 is spaced relative to the input shaft 21, a force can be exerted on the first element 80 in the direction of rotation. Since the first element 80 is rotatable together with the input shaft 21, the force exerted on the first element 80 in the direction of rotation is transmitted to the driver via the input shaft 21 and the steering wheel 11. This likely affects the steering feel. The steering feel can be improved by aligning the center of mass G1 of the first element 80 with the centerline CL of the input shaft 21.

[0079] Next, a second embodiment according to the present invention will be described with reference to the figures. Second embodiment

[0080] Fig. Figure 7 illustrates the main section of a steering device according to the second embodiment, and its representation corresponds to that shown in Figure 7. Fig. 5. According to a steering device 10A of the second embodiment, the construction of a steering angle limiting device 70A differs from that of the steering device 10 of the first embodiment (see Fig. 2) Other basic structures are identical to those of the steering device according to the first embodiment. The components common to the first embodiment are identified by the same reference numeral, and a detailed description thereof is omitted.

[0081] Also with reference to Fig. 8 comprises a second element 90A, a second weight 93A, which is provided on the second base 91. According to this embodiment, the second weight 93A is arranged such that it overlaps the line L1, which extends from the second projection 92 and passes through the centerline CL of the input shaft 21. The second weight 93A is provided along the outer circumference of the second base 91.

[0082] It should be noted that it is not always necessary for the second weight 93A to have a structure such that it overlaps line L1. Such a weight can be formed from two weight components, or only part of the second base 91 can be formed from a heavier material than the other parts, for example, through two-color casting.

[0083] The center of mass G2 of the second element 90A is located between the center line CL of the input shaft 21 and the tip of the second weight 93A. Since the center of mass G2 of the second element 90A is located between the center line CL of the input shaft 21 and the tip of the second weight 93A, in the normal state the second weight 93A is on the lower side and the second projection 92 is on the upper side.

[0084] The stops 61a and 61a are located at positions spaced apart from the second projection 92 when the second projection 92 is positioned on the upper side. The stops 61a and 61a are located below the center line CL of the input shaft 21. The distance from the second projection 92 to each of the stops 61a and 61a is the same.

[0085] The steering device 10A according to the second embodiment can be summarized as follows.

[0086] Referring to Fig. 1 and Fig. 7 includes the steering device 10A: the first element 80, which surrounds the first base 81, which is to be rotated when the steering wheel 11 is turned, and which is rotatable together with the input shaft, and includes the first projection 82, which projects from the first base 81 in the radial direction or in the axial direction; the second element 90A, comprising the second base 91, which surrounds the first base 81, the second projection 92, which extends from the second base 91 and into the path of movement of the first projection 82, and the second weight 93A, which is arranged to overlap the line L1 extending from the second projection 92 and passing through the centerline CL of the input shaft 21, wherein the second element is rotatable together with the first element 80 when the first projection 82 is in contact with the second projection 92, and wherein the center of mass G2 is arranged between the centerline CL of the input shaft 21 and the tip of the second weight 93A; and the stops 61a and 61a, which are separated from the second projection 92 and are formed in the path of movement of the second projection 92 when the center of mass G2 of the second element 90A is arranged below the center line CL of the input shaft 21, and which are suitable to limit the rotation of the steering wheel 11 by means of the input shaft 21 when the second projection 92 is in contact.

[0087] The steering device 10A according to the second embodiment also achieves the predetermined advantageous effects of the present invention.

[0088] Next, a third embodiment according to the present invention will be described with reference to the figure. Third embodiment

[0089] Fig. 9 represents the main section of a steering device according to the third embodiment and its representation corresponds to that shown in Fig. 5. According to a steering device 10B of the third embodiment, the structure of a first element 80B of a steering angle limiting device 70B differs from that of the steering device 10 of the first embodiment (see Fig. 2) Other basic structures are identical to those of the steering device according to the first embodiment. The components common to the first embodiment are identified by the same reference numeral, and a detailed description thereof is omitted.

[0090] The first element 80B is formed only by a first projection 82B, which is rod-shaped and extends radially from the input shaft 21. The first element 80B has a tip that is inserted into the input shaft 21, and its thickness increases towards the radially outer side.

[0091] The steering device 10B according to the third embodiment, as described above, can achieve the predetermined advantageous effects of the present invention.

[0092] Next, a fourth embodiment according to the present invention will be described with reference to the figure. Fourth embodiment

[0093] Fig. 10 represents the main section of a steering device according to the fourth embodiment and its representation corresponds to that shown in Fig. 5. According to a steering device 10C of the fourth embodiment, the structure of a first element 80C differs from that of a steering angle limiting device 70C (see Fig. 7) from that of the steering device 10A according to the first embodiment (see Fig.2) Other basic structures are identical to those of the steering device according to the second embodiment. The components common to the first or the second embodiment are identified by the same reference numerals, and a detailed description thereof is omitted.

[0094] The first element 80C is formed only by a first projection 82C, which is rod-shaped and extends radially from the input shaft 21. The first element 80C has a tip that is inserted into the input shaft 21, and its thickness increases towards the radially outer side.

[0095] The steering device 10C according to the fourth embodiment, as described above, can also achieve the predetermined advantageous effects of the present invention.

[0096] It should be noted that in the first and second embodiments, the first weight is not a significant component. In a design where the adverse effect of the steering feel has little impact on the driver, the first weight can be omitted.

[0097] Furthermore, in the third and fourth embodiments, the center of mass of the first element may or may not coincide with the center line of the input wave.

[0098] It should be noted that the respective embodiments can be combined with one another. The present invention is not limited to the embodiments described above, as long as the functions and advantageous effects of the present invention are achievable. Commercial applicability

[0099] The steering device according to the present invention is suitably installed in a vehicle, such as a passenger car. Reference symbol list 10, 10A, 10B, 10C steer-by-wire steering device 11 Steering wheel 21 Input wave 61a attack 80, 80C, 80C first element 81 first base 82, 82B, 82C first lead 83 first weight 90, 90A second element 91 second base 92 second lead 93A second weight CL midline of the input wave G1 Center of mass of the first element G2 Center of mass of the second element

Claims

[1] Steer-by-wire steering device (10; 10A; 10B; 10C) comprising: a first element (80, 80B, 80C) that rotates together with an input shaft (21) when a steering wheel (11) is turned, and that includes a first projection (82, 82B, 82C) that extends from the input shaft (21) in a radial direction; a second element (90, 90A) provided on the input shaft (21), having a center of mass (G2) spaced relative to the center line (CL) of the input shaft (21) and a second projection (92) that extends into a path of movement of the first projection (82, 82B, 82C), wherein the second element (90) is rotatable together with the first element (80, 80B, 80C) when the first projection (82, 82B, 82C) is in contact with the second projection (92); and a stop (61a) which is arranged in a position suitable for adjoining only one path of movement of the second element (90) when the second element (90) is rotated by the first element (80, 80B, 80C), and which is suitable for limiting a rotation of the steering wheel (11) by means of the input shaft (21) when the second projection (92) is in contact with it, wherein the second projection (92) comprises a radial projection (92a) extending in the radial direction from the second base (91) and an axial projection (92b) extending in the direction along the axial line (CL) from the radial projection (92a), and wherein the axial projection (92b) is able to rest against the first projection (82, 82B, 82C) and against the stop (61a). [2] Steer-by-wire steering device (10) according to claim 1, wherein the first element (80) further comprises a first base (81) surrounding the input shaft (21). [3] Steer-by-wire steering device (10) according to claim 2, wherein the second element (90, 90A) further comprises a second base (91) surrounding the first base (81). [4] Steer-by-wire steering device (10) according to any one of claims 1 to 3, wherein the first element (80) further comprises a first weight (83) which aligns a center of mass (G1) of the first element (80) with the center line (CL) of the input shaft (21). [5] Steer-by-wire steering device (10) according to claim 1, wherein the second element (90) further comprises a second base (91) surrounding the input shaft (21) and a second weight (93A) provided on the second base (91), and wherein the center of mass (G2) of the second element (90) is arranged between the center line (CL) of the input shaft (21) and the second weight (93A). [6] Steer-by-wire steering device according to claim 3, wherein the first projection (82) extends from the first base (81) in a radial direction or in an axial direction; the second projection (92) extends from the second base (91) and into a path of motion of the first projection (82), with the center of mass (G2) of the second element (90) being located between a center line (CL) of the input wave (21) and the second projection (92); and wherein the stop (61a) is separated from the second projection (92) when the center of mass (G2) of the second element (90) is located below the center line (CL) of the input shaft (21). [7] Steer-by-wire steering device according to claim 3, wherein the first projection (82) extends from the first base (81) in a radial direction or in an axial direction; the second element (90A) comprises a second weight (93A) arranged such that it overlaps a line (L1) extending from the second projection (92) and passing through a center line (CL) of the input shaft (21), and wherein a center of mass (G2) of the second element (90A) is arranged between the center line (CL) of the input shaft (21) and a tip of the second weight (93A), and the stop (61a) is separated from the second projection (92) when the center of mass (G2) of the second element (90A) is located below the center line (CL) of the input shaft (21). [8] Vehicle with the steer-by-wire steering device according to any one of claims 1 to 7.

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