JP5405969B2 - Motorcycle steering device - Google Patents

Description

  The present invention relates to a motorcycle steering apparatus, and more particularly, to a motorcycle steering apparatus to which power assist means for applying an auxiliary steering force by an electric motor is applied.

  2. Description of the Related Art Conventionally, in a vehicle steering apparatus, a configuration in which power assist means for assisting steering force with an electric motor is applied so as to reduce an operation burden on an occupant is known.

  In Patent Document 1, in a straddle-type four-wheel vehicle in which a front wheel is steered by a bar-type handle extending in the vehicle width direction, a stem coupled to a lower portion of the handle and pivotally supported by a head pipe is disclosed. A power assist means is disclosed in which an auxiliary steering force by an electric motor is input to a shaft.

JP 2006-232060 A

  However, the power assist means for a four-wheeled vehicle described in Patent Document 1 only gives an auxiliary steering force corresponding to the steering force by the occupant, and a method for giving an auxiliary steering force suitable for a two-wheeled vehicle is particularly considered. Was not. More specifically, in a two-wheeled vehicle that travels only on the front and rear wheels, a “stagger” occurs when the vehicle body tilts to the left and right when traveling at a very low speed. It is necessary to keep the balance of the vehicle body by moving. In particular, in a heavy vehicle, it can be considered that the burden on the steering wheel operation for maintaining this balance also increases. The technique described in Patent Document 1 does not consider using power assist means to assist such a steering operation.

  The object of the present invention is to solve the above-mentioned problems of the prior art, one of which makes it possible to control the attitude of a motorcycle at low speed using power assist means, and the other uses ratio variable means. An object of the present invention is to provide a steering device for a motorcycle in which an optimum steering ratio can be obtained in all speed ranges.

  In order to achieve the above object, according to the present invention, a pair of left and right front forks (4) for pivotally supporting a front wheel (WF) is mounted on a top bridge (16) and a vehicle body lower side of the top bridge (16). A steering wheel (5) operated by an occupant in a steering device (30) for a motorcycle that is held by a bottom bridge (17) and that supports the front fork (4) in a steerable manner with respect to a vehicle body frame (2). A power assist means (W1) for applying an auxiliary steering force by the second motor (M2) according to an input torque (Mz) inputted to the vehicle, a vehicle speed detecting means (92) for detecting the vehicle speed (V), and the input An input torque detecting means (48) for detecting torque (Mz), and a steering ratio (j) which is a ratio between a rotation angle of the handle (5) and a steering angle of the front wheel (WF) is detected. A steering ratio detecting means (92) for performing the detection, a roll angular speed detecting means (93) for detecting an angular speed (ω) in the roll direction of the vehicle body, and a control section (100) for controlling the second motor (M2). The control unit (100) controls the second motor (M2) based on values of the vehicle speed (V), the input torque (Mz), and the angular velocity (ω) in the roll direction. There are features.

  Further, based on the function of the vehicle speed (V), the input torque (Mz), and the steering ratio (j) (T1 = Mz · k (k = f (j, V))), the auxiliary steering force is Steering angle for canceling the angular velocity (ω) in the roll direction based on the power assist torque calculating means (104) for obtaining the power assist torque (T1) and the vehicle speed-angular velocity map that changes according to the vehicle speed (V). Steering angle correction torque calculation means (105) for obtaining correction torque (T2), and the second motor (M2) adds the power assist torque (T1) and the steering angle correction torque (T2) together. The control unit (100) controls the position of the center of gravity (G) of the vehicle body when the vehicle speed (V) is equal to or lower than a predetermined value and the angular velocity (ω) in the roll direction is equal to or higher than the predetermined value. Reed direction The second feature is that the strike force is increased.

  In addition, a steering ratio variable means (S1) for arbitrarily changing the steering ratio (j) by the first motor (M1) is provided, and the control unit (100) is a function of the vehicle speed (V) (J = A third feature is that the first motor (M1) is controlled based on the difference between the target steering ratio (J) obtained by f (V)) and the steering ratio (j).

  Further, a pair of left and right front forks (4) that rotatably support the front wheel (WF) is held by a top bridge (16) and a bottom bridge (17) located on the vehicle body lower side of the top bridge (16). In addition, in the steering device (30) for the motorcycle that supports the front fork (4) so as to be steerable with respect to the vehicle body frame (2), the input torque (Mz) input to the handle (5) operated by the occupant. Accordingly, a power assist means (W1) for providing an auxiliary steering force by the second motor (M2), a vehicle speed detection means (92) for detecting the vehicle speed (V), and an input torque detection for detecting the input torque (Mz). Means (48), and a steering ratio detection means (92) for detecting a steering ratio (j) which is a ratio of a rotation angle of the handle (5) and a steering angle of the front wheel (WF). A roll angular velocity detecting means (93) for detecting an angular velocity (ω) in the roll direction of the vehicle body, and a control unit (200) for controlling the second motor (M2), the control unit (200) comprising: A fourth feature is that the second motor (M2) is controlled based on the values of the vehicle speed (V) and the input torque (Mz).

  Further, based on the function of the vehicle speed (V), the input torque (Mz), and the steering ratio (j) (T = Mz · k (k = f (j, V))), A fifth feature is that power assist torque calculating means (204) for obtaining power assist torque (T) is provided, and the second motor (M2) is controlled based on the value of the power assist torque (T). There is.

  In addition, a steering ratio variable means (S1) for arbitrarily changing the steering ratio (j) by the first motor (M1) is provided, and the control unit (200) is a function of the vehicle speed (V) (J = There is a sixth feature in that the first motor (M1) is controlled based on the difference between the target steering ratio (J) obtained by f (V)) and the steering ratio (j).

  According to the first and second features, it is possible to control the steering apparatus including the power assist means in consideration of the angular velocity in the roll direction of the vehicle body. As a result, it is possible to automatically control the steering operation for preventing the vehicle body from wobbling, and the operation burden on the occupant can be reduced. In addition, it is possible to reduce wobbling of the vehicle body particularly in the low speed range, and to improve the stability and mobility of the motorcycle in all speed ranges.

  Furthermore, since the stability and mobility of the motorcycle are improved by the steering device, the fatigue of the occupant is reduced, and the same stability and mobility can be obtained even if the rigidity of the body frame is reduced to reduce the weight. Further, the structure of the vehicle body can be simplified, such as eliminating the need for a steering damper.

  According to the third feature, the steering device including the power assist means and the steering ratio variable means can be controlled in consideration of the angular velocity in the roll direction of the vehicle body. As a result, an optimum steering ratio can be obtained in all speed ranges from low speed to high speed, and the stability and mobility of the motorcycle can be improved.

  According to the fourth and fifth features, the steering device provided with the power assist means can be controlled with a simple configuration without using the roll angular velocity detection means, and the stability and mobility of the motorcycle can be enhanced. In addition, since the auxiliary steering force is applied to the steering operation that prevents the vehicle body from falling down, the operation burden on the occupant can be reduced.

  According to the sixth feature, the steering device including the power assist means and the steering ratio variable means can be controlled without considering the angular velocity in the roll direction of the vehicle body. As a result, an optimum steering ratio can be obtained in all speed ranges from low speed to high speed, and the stability and mobility of the motorcycle can be improved.

1 is a side view of a motorcycle to which a steering device for a motorcycle according to an embodiment of the present invention is applied. It is a side view of a steering device. It is a top view of a steering device. It is side surface sectional drawing of a steering device. It is a side view of a steering device in the state where a slider moved to the vehicle body front side. It is an upper surface sectional view of a steering device. It is operation | movement explanatory drawing of a steering ratio variable means. It is a block diagram which shows the structure of the control part of the steering apparatus which concerns on this embodiment. Fig. 3 is a schematic diagram showing a fluctuation state of a center of gravity of a motorcycle. It is a schematic diagram which shows a mode that a gravity center moves with handle | steering-wheel operation. It is a schematic diagram which shows the process in which a gravity center returns to an upright state with steering wheel operation. It is a block diagram which shows the structure of the control part of the steering device which concerns on 2nd Embodiment of this invention. It is a graph which shows the relationship between a vehicle speed and a steering ratio.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of a motorcycle 1 to which a motorcycle steering device 30 (hereinafter also simply referred to as a steering device 30) according to an embodiment of the present invention is applied. A front wheel WF as a steered wheel of the motorcycle 1 is rotatably supported at the lower ends of the pair of left and right front forks 4. The steering device 30 according to one embodiment of the present invention is disposed at the front end of the vehicle body frame 2. The steering device 30 can steer the front wheel WF by a rotation amount different from the input operation amount to the handlebar 5 by a steering ratio variable means described later, and can assist the steering force of the front wheel WF by a power assist means. This is an electric steering mechanism.

  The front fork 4 is supported by a top bridge 16 located on the upper side of the steering device 30 and a bottom bridge 17 located on the lower side of the steering device 30. The front wheel WF is steered when the top bridge 16 and the bottom bridge 17 are integrally rotated with respect to the steering device 30. Above the top bridge 16, a handle bar 5 having a pair of left and right handle grips 6 held by a passenger is disposed.

  A front cowl 7 as an exterior part is disposed on the front side of the vehicle body of the handle bar 5. An engine hanger 3 is provided below the vehicle body frame 2 so as to extend rearward and downward from the vehicle body. An engine 8 serving as a power source for the vehicle is fixed so as to be suspended by the engine hanger 3. A rear wheel WR as a drive wheel is rotatably supported by a rear end portion of a swing arm (not shown) disposed on the center side in the vehicle width direction of the muffler 10. The front end portion of the swing arm is pivotally supported by a swing arm pivot 9 provided at the lower rear of the body frame 2.

  A fuel tank cover 19 having a fuel filler lid 11 is disposed in front of the vehicle body of the seat 12 on which the driver is seated. A rear seat 13 on which a passenger sits is provided behind the seat 12. A trunk 14 is attached to the rear of the rear seat 13 at the center in the vehicle width direction, and a pair of left and right side cases 15 are attached to the lower side of the trunk 14.

  FIG. 2 is a side view of the steering device 30 according to an embodiment of the present invention. FIG. 3 is a top view of the steering device 30. The steering device 30 is disposed on the head pipe at the front end of the vehicle body frame 2. In the present embodiment, a support case (head pipe) 18 formed by aluminum casting or the like is coupled to the front end portions of a pair of left and right main frames 2a made of aluminum pipe material or the like. The steering device 30 is fixed to the front end portion of the vehicle body frame 2 by fixing the steering device 30 to the recess formed in the support case 18 using a fastening member or the like. At this time, the surface on the vehicle body front side of the steering device 30 is exposed from the support case 18 to the vehicle body front side. Not only the front end portion of the main frame 2 a but also the upper end portion of the engine hanger 3 is coupled to the support case 18. The support case 18 according to this embodiment corresponds to a head pipe of a normal two-wheeled vehicle, and enables the front fork 4 to be rotationally steered with respect to the vehicle body frame 2. The support case 18 may be formed integrally with the front end portion of the vehicle body frame 2.

  Here, in a normal motorcycle, a pair of left and right front forks are supported by a top bridge and a bottom bridge, and a stem shaft as a pivot shaft for connecting and fixing the top bridge and the bottom bridge is provided at the front end of the vehicle body frame. The front wheels can be steered by being pivotally supported on the formed head pipe. On the other hand, the steering device 30 according to the present embodiment has a configuration different from that of a normal motorcycle because the front wheel WF can be steered by a steering angle and a steering force different from the input operation to the handlebar 5. ing.

  In the present embodiment, the bottom bridge 17 is fixed to the output shaft 66 provided at the lower portion of the steering device 30, so that the bottom bridge 17, the top bridge 16, and the front fork 4 are moved along with the rotation operation of the output shaft 66. It is comprised so that it may rotate integrally. The handlebar 5 that is input by the occupant is not fixed to the top bridge 16 so that the handlebar 5 can be rotated at an angle different from the swing angle of the front fork 4. It is directly connected to an input shaft 40 provided at the top. In the present embodiment, the rotation shafts of the input shaft 40 and the output shaft 66 are configured to be coaxial.

  The steering device 30 has an upper housing 31 and a lower housing 32, and the steering ratio variable means and the power assist means described above are housed in an internal space formed by both. The upper housing 31 and the lower housing 32 are fixed with three fastening screws 33. A first motor M1 for operating the steering ratio variable means and a second motor M2 for operating the power assist means are respectively attached to the rear side of the vehicle body of the lower housing 32. The first motor M1 and the second motor M2 are arranged such that their respective axes J1 and J2 are oriented in parallel in the vehicle longitudinal direction and are positioned between the top bridge 16 and the bottom bridge 17. . In this embodiment, the second motor M2 is disposed at a slightly lower position in the vertical direction of the vehicle body than the first motor M1, but is arranged so that the axes J1 and J2 are positioned at substantially the same height. You may set up.

  Referring also to FIG. 3, similarly to the top bridge 16, the bottom bridge 17 is formed with an insertion hole 4 a for supporting the pair of left and right front forks 4. The steering device 30 is configured to fit in a space between the left and right front forks 4. Accordingly, it becomes easy to secure a large front wheel steering angle, and the weight of the steering device 30 can be concentrated in the center in the vehicle width direction. The steering device 30 is arranged so as not to protrude from the front end surface of the front fork 4 to the front side of the vehicle body except for one boss portion on the front side of the vehicle body through which the fastening screw 33 passes.

  Further, the first motor M1 and the second motor M2 are disposed so as to fit inside the support case 18, that is, inside the vehicle body, without protruding from the outer wall of the main frame 2a and the support case 18 to the vehicle body front side. . In the present embodiment, the rotation shafts J1 and J2 of the motors M1 and M2 are oriented in the longitudinal direction of the vehicle body, and the rear end portions of the motors M1 and M2 are disposed so as to slightly protrude from the rear end surface of the support case 18. Yes. According to such an arrangement of the first and second motors, for example, the position of the center of gravity of the steering device 30 can be moved to the rear side of the vehicle body as compared with a configuration in which both motors are arranged on the front side of the vehicle body of the steering device 30. It is possible to reduce the influence of the weight of the steering device 30 on the vehicle body balance. In addition, since the first and second motors do not protrude outward from the main frame 2a, both motors can be prevented from being affected by external force, moisture, and the like.

  In the present embodiment, a motor that is larger than the first motor M1 that drives the steering ratio variable means is applied to the second motor M2 that assists the steering force (for example, the first motor M1: 0. 3Nm, second motor M2: 1.3Nm). In the present embodiment, the first motor M1 is disposed on the right side in the vehicle width direction, and the second motor M2 is disposed on the left side in the vehicle width direction and below the first motor M1. Such an arrangement of the first and second motors is suitable, for example, in a vehicle in which the muffler is disposed only on the right side of the vehicle body in order to optimize the weight balance by reducing the weight on the right side in the vehicle width direction. The arrangement positions of the motors M1 and M2 can be variously modified according to the shapes of the upper and lower housings 31 and 32 and the body frame.

  If the mounting recess of the steering device 30 provided in the storage case 18 is configured so that a head pipe used in a normal motorcycle can be mounted, the present invention uses a common body frame. It is possible to produce a vehicle to which the steering device according to the above is applied and a vehicle having a normal steering mechanism.

  FIG. 4 is a side sectional view of the steering device 30. FIG. 5 is a side view showing a state in which a slider S1 described later has moved to the front side of the vehicle body. The same reference numerals as those described above denote the same or equivalent parts. As described above, the steering device 30 has the input shaft 40 that protrudes upward and the output shaft 66 that protrudes downward. A handle base 43 that rotates integrally with the input shaft 40 by spline fitting is attached to the upper end portion of the input shaft 40 by a nut 41 and a washer 42. The handle base 43 and the top bridge 16 are rotatably engaged with each other by a bearing 44. The handle bar 5 operated by the occupant is fixed to the handle base 43, and an input operation to the handle bar 5 is directly input to the input shaft 40 without passing through the top bridge 16.

  A cylindrical portion 31 a is formed on the upper portion of the upper housing 31 of the steering device 30. A dust seal 45 that prevents moisture and the like from entering the steering device 30 and a bearing 46 that supports the input shaft 40 are disposed at the upper end of the cylindrical portion 31a. An oil seal 47 is disposed below the bearing 46, and two torque sensors 48 serving as input torque detecting means are provided below the oil seal 47 below. A magnetostrictive type is applied to the torque sensor 48, and a magnetic ring 40 a is attached to the outer peripheral portion of the input shaft 40 at a portion facing the torque sensor 48. In the present embodiment, the torque sensor 48 detects the amount of twist of the input shaft 40, and the steering torque by the occupant's steering wheel operation is calculated based on this amount of twist.

  A columnar input member 50 is formed at the lower end of the input shaft 40. The input member 50 is rotatably supported by a bearing 49 fitted to the upper housing 31. Two steel balls 51 and 52 are rotatably supported on the lower surface of the input member 50, and the input member 50 and the slider S1 disposed adjacent thereto are in contact with only the steel balls 51 and 52. It is configured. A guide rail 54 for restricting the rolling direction of the steel ball 51 is formed on the front side of the upper surface of the slider S1 so as to be directed in the longitudinal direction of the vehicle body. Between the upper housing 31 and the lower housing 32, an O (O) ring 90 that keeps the internal space sealed is disposed.

  The columnar slider S1 as the steering ratio varying means is rotatably supported on the base SB by a large-diameter bearing 53 and is movable in the longitudinal direction of the vehicle body by driving the first motor M1. Yes. The position of the slider S1 shows a neutral position in FIG. 4, and FIG. 5 shows a state where the slider S1 is moved to the front side of the vehicle body. Similarly, the slider S1 can move from the neutral position to the rear side of the vehicle body. Here, the slider S1 is described as the steering ratio variable means. However, in the following, the entire system including the input member 50, the drive mechanism of the slider S1 and the like in addition to the slider S1 may be referred to as the steering ratio variable means. is there.

  Two steel balls 55 and 56 are rotatably supported on the lower surface of the slider S1, and the top plate 67 of the worm wheel W1 disposed adjacent to the slider S1 is in contact with only the steel balls 55 and 56. Is configured to do. A guide rail 57 for guiding the steel ball 56 is formed on the upper surface portion of the top plate 67 so as to be directed in the longitudinal direction of the vehicle body. Here, the worm wheel W1 has been described as the power assist means, but hereinafter, the entire system including the drive mechanism of the worm wheel W1 in addition to the worm wheel W1 may be referred to as power assist means.

  The worm wheel W1 and the top plate 67 are fixed to the output shaft 66 so that they cannot rotate relative to each other. The output shaft 66 is rotatably supported by bearings 58 and 59 below the worm wheel W1. The bearings 58 and 59 are fitted to a bearing collar 62 having a male screw portion on the outer peripheral portion, and the lower housing is formed by screwing the bearing collar 62 into a female screw portion provided in an opening of the lower housing 32. 32. An O-ring 60 is disposed between the lower housing 32 and the bearing collar 62. The bearing collar 62 is fixed to the lower housing 32 so as not to rotate by fastening a lock ring 63 to the outer peripheral portion thereof. A dust seal 61 is disposed below the bearing 59.

  The output shaft 66 and the mounting collar 64, the mounting collar 64, and the bottom bridge 17 are fitted by a spline structure, respectively, and are fastened to each other by fastening a nut 65 to the tip of the output shaft 66. With the configuration described above, the rotational driving force transmitted to the output shaft 66 is transmitted from the bottom bridge 17 to the front fork 4 and to the top bridge 16 that supports the front fork 4 at the upper end portion thereof. In the present embodiment, the input shaft 40 and the output shaft 66 are coaxially positioned, and the output shaft 66 and the front fork 4 are configured to be parallel.

  FIG. 6 is a top sectional view of the steering device 30. The same reference numerals as those described above denote the same or equivalent parts. As described above, the worm wheel W1 directly connected to the output shaft 66 can be rotated at an arbitrary speed by the second motor M2. The second motor M2 is based on various sensor information of the motorcycle 1 (steering torque, vehicle speed, engine speed, number of gears, body roll angle and pitch angle, yaw angle, rudder angle, steering ratio, etc.). It is driven to properly assist the steering force. As a result, for example, it is possible to perform control such as reducing the operating force when operating the steering wheel when the vehicle is stopped, or driving to an optimum steering torque in a predetermined traveling state.

  The second motor M2 is configured by housing a rotating shaft 83 to which a coil 84 is attached in a cover 85 having a plurality of permanent magnets attached to the inner periphery thereof. The cover 85 is fastened to the lower housing 32 together with the base member 81 by screws 82. The rotating shaft 83 is pivotally supported by a bearing 80 fitted to the base member 81. The end of the rotating shaft 83 is connected to a shaft 87 to which a worm (screw gear) 77 is attached via a connecting member 79. The shaft 87 is pivotally supported by the bearing 78 on the vehicle body rear side of the worm 77 and is also pivotally supported by the bearing 76 on the vehicle body front side of the worm 77.

  On the other hand, the slider S1 is configured to be movable in the longitudinal direction of the vehicle body by the first motor M1. The first motor M1 has a configuration in which a rotating shaft 73 to which a coil 74 is attached is housed in a cover 75 having a plurality of permanent magnets attached to the inner periphery thereof. The cover 75 is fastened to the lower housing 32 together with the base member 72 by screws 86.

  The rotating shaft 73 is pivotally supported by a bearing 71 fitted to the base member 72, and an end portion of the rotating shaft 73 is connected to a shaft 69 via a connecting member 70. A feed screw mechanism (not shown) including a male screw formed on the shaft 69 side and a female screw formed on the slider S1 side is provided between the shaft 69 and the slider S1. Thus, the slider S1 is configured to move in the longitudinal direction of the vehicle body as the shaft 69 rotates.

  The guide rail 54 formed on the upper surface of the slider S1 and the guide rail 57 formed on the top plate 67 of the worm wheel M1 are respectively formed along a guide rail locus 68 shown in FIG. . The rotational driving force input to the input shaft 40 from the handle bar 5 is transmitted from the steel ball 51 to the slider S1 via the guide rail 54. Further, the rotational driving force transmitted to the slider S1 is the steel ball 56. To the worm wheel W <b> 1 via the guide rail 57.

  In the present embodiment, the axis J1 of the first motor M1 and the axis J2 of the second motor M2 are arranged in parallel with the vehicle body center line C, respectively. Further, the distance from the vehicle body center line C to the axis line J1 and the distance from the vehicle body center line C to the axis line J2 are set to be approximately equal, thereby optimizing the weight balance in the vehicle width direction.

  In the present embodiment, the steel ball 51 on the rear side of the vehicle body of the input member 50 and the steel ball 55 on the front side of the vehicle body of the worm wheel W1 are not involved in the transmission of the rotational driving force, respectively, and the slider S1 serves as the rotation axis. It has only the function of supporting it so as not to tilt. Here, with reference to FIG. 7, the configuration of the steering ratio varying means according to the present embodiment will be described.

  FIG. 7 is an explanatory diagram of the operation of the steering ratio variable means. In this figure, columnar parts D, E, and F stacked in three upper and lower stages correspond to the input member 50, the slider S1, and the worm wheel W1 in the above embodiment, respectively. Further, the ball B1 supported on the lower surface of the part D so as to be able to roll is equivalent to the steel ball 51, and the ball B2 supported so as to be able to roll on the lower surface of the part E is equivalent to the steel ball 56. Here, the sphere B1 is restricted from relative movement in the circumferential direction with respect to the upper surface portion of the component E, and the sphere B2 is also restricted from relative movement in the circumferential direction relative to the upper surface portion of the component F. It is assumed that As a result, the rotational driving force input to the component E is transmitted to the component E by the ball B1, and further, the rotational driving force transmitted to the component E is transmitted to the component F by the ball B2. In the steering device 30 shown in the embodiment, the relative movement in the circumferential direction is restricted by the guide rails 54 and 57.

  First, the case (a) in which the part E is in the neutral position without sliding will be referred to. In (a), the rotation axes DO, EO, and FO of the parts D, E, and F are on the same axis. At this time, since the parts D, E, and F rotate synchronously, when the part D is rotated by θ degrees in the illustrated counterclockwise direction, the part F is similarly rotated by θ degrees.

  Next, reference is made to the case (b) in which the part E is slid by a predetermined distance toward the front side of the vehicle body. In (b), when the part E slides to the front side of the vehicle body, the rotational axis EO of the part E moves to the front side of the vehicle body from the rotational axes DO and FO of the parts D and F. Then, since the component E rotates about the rotation axis EO, when the component D is rotated by θ degrees, the rotation angle of the component E becomes θ1 degrees smaller than θ degrees. The decrease in the rotation angle of the component E is transmitted to the component F as it is, and the rotation angle of the component F is θ1 degree smaller than the input angle.

  Then, reference is made to the case (c) in which the part E is slid by a predetermined distance toward the rear side of the vehicle body. In (c), when the part E slides to the rear side of the vehicle body, the rotational axis EO of the part E moves to the rear side of the vehicle body from the rotational axes DO and FO of the parts D and F. Then, since the component E rotates about the rotation axis EO, when the component D is rotated by θ degrees, the rotation angle of the component E becomes θ2 degrees larger than θ degrees. The increase in the rotation angle of the component E is transmitted to the component F as it is, and the rotation angle of the component F becomes θ2 degrees larger than the input angle.

  As described above, according to the steering ratio varying unit according to the present embodiment, the output rotation angle of the component D with respect to the input rotation angle of the component D can be arbitrarily set by sliding the component E to an arbitrary position in the longitudinal direction of the vehicle body. It becomes possible to change. That is, in the embodiment (see FIG. 4), the ratio between the rotation angle of the input shaft 40 and the rotation angle of the output shaft 66 can be arbitrarily changed. The first motor M1 described above is based on various sensor information of the motorcycle 1 (steering torque, vehicle speed, engine speed, gear stage number, body roll angle and pitch angle, yaw angle, steering angle, steering ratio, etc.) Driven to be set to an optimum steering ratio. As a result, for example, as the vehicle speed of the motorcycle increases, the steering angle of the front wheel with respect to the same steering wheel operation amount is reduced, or the steering angle with respect to the steering wheel operation is increased when balancing by steering wheel operation at extremely low speeds. It becomes executable.

  Further, according to the configuration of the steering ratio variable means as described above, the ratio of the rotation angle between the input shaft and the output shaft can be arbitrarily changed without using a complicated mechanism such as a plurality of gears. It is possible to reduce the axial dimension. In the steering apparatus according to the present invention, a steering apparatus including both a steering ratio variable means and a power assist means is housed between a top bridge and a bottom bridge that support the front fork vertically. The application of the steering ratio variable means that simplifies the process and reduces the size greatly contributes.

  In addition, by storing the torque detection mechanism, steering ratio variable means, and power assist means in order from the top between the top bridge and the bottom bridge, the steering torque can be accurately adjusted before the rotational driving force of the motor is applied. It becomes possible to detect. Further, the steering device can be concentrated in the vicinity of the front end portion of the vehicle body frame. Further, since the assist is performed on the member (worm wheel) fixed to the output shaft, it is possible to reduce the loss due to mechanical friction and the like, and to efficiently convert the output of the second motor M into the steering force. .

  FIG. 8 is a block diagram illustrating a configuration of a control unit of the steering apparatus according to the present embodiment. The same reference numerals as those described above denote the same or equivalent parts. The control unit 100 included in an ECU or the like that controls the engine includes an actual steering ratio detection unit 92 that detects a steering ratio j that is a ratio of the rotation angle of the handle 5 and the steering angle of the front wheel WF, and the vehicle speed of the motorcycle. A vehicle speed detecting means 91 for detecting V, an input torque detecting means (torque sensor) 48 for detecting an input torque (Mz) generated by an occupant steering the steering wheel 5, and a roll for detecting an angular velocity ω in the roll direction of the vehicle body Information from the angular velocity detection means 93 is input. The controller 100 drives the first motor M1 and the second motor M2 based on these pieces of sensor information. In the present embodiment, the second motor M2 is controlled based on the values of the vehicle speed V, the input torque Mz, and the angular velocity ω in the roll direction, while the first motor M1 is controlled based on the values of the vehicle speed V and the steering ratio j. Configured to control.

  In the present embodiment, the vehicle speed detection means 91 is configured by a hall sensor (not shown) that detects the rotational speed of the rear wheel WR and the like, and the actual steering ratio detection means 92 detects the sliding amount of the slider S1. The roll angular velocity detecting means 93 is constituted by a gyro sensor (not shown) mounted substantially in the center of the vehicle body.

  The target steering ratio calculation unit 101 calculates the target steering ratio J based on the vehicle speed V detected by the vehicle speed detection unit 91. This calculation process is executed by substituting the vehicle speed V into a predetermined function (J = f (V)). The target steering ratio J indicates the magnitude of the rotation angle of the front wheel WF relative to the rotation angle of the handle 5, and as shown in FIG. 13, for example, an initial value Ja (for example, when the vehicle speed V is zero) (for example, 1.4) to a predetermined value Jb (for example, 1.0) at a predetermined vehicle speed V1 (for example, 30 km / h), it can be set to decrease as the vehicle speed V increases.

  The first motor drive amount calculation means 102 calculates the first motor drive amount p1 (p1 = | J−j |) based on the difference between the target steering ratio J and the actual steering ratio (steering ratio) j. The first motor drive control unit 103 drives the first motor M1 based on the calculated value of the first motor drive amount p1.

  Further, the power assist torque calculation means 104 uses the power assist torque T1 (T1 = Mz) based on the vehicle speed V detected by the vehicle speed detection means 91, the input torque Mz detected by the input torque detection means 48, and the target steering ratio J. K) is calculated. Here, the assist coefficient k is a function of the target steering ratio J and the vehicle speed V (k = f (J, V)). For example, the assist coefficient k maintains a constant value up to a predetermined vehicle speed, and then gradually decreases as the vehicle speed increases. Can be set to.

  On the other hand, the steering angle correction torque calculation means 105 calculates the steering angle correction torque T2 based on the vehicle speed V detected by the vehicle speed detection means 91 and the roll angular speed ω detected by the roll angular speed detection means 93. This calculation process is performed by PID control or modern control for canceling the generated roll angular velocity ω. The vehicle speed V is used when selecting a data map used for calculating the steering angle correction torque T2.

  The second motor drive amount calculation means 106 calculates the second motor drive amount p2 based on the power assist torque T1 and the steering angle correction torque T2. This calculation process is performed by adding the power assist torque T1 and the steering angle correction torque T2 (p2 = T1 + T2). The second motor drive control unit 107 drives the second motor M2 based on the calculated value of the second motor drive amount p2.

  Hereinafter, with reference to FIGS. 9 to 11, a description will be given of the principle that the wobbling of the vehicle body is reduced by controlling the driving of the second motor M2.

  FIG. 9 is a schematic diagram showing a variation state of the center of gravity G of the motorcycle. In this figure, the state which looked at the vehicle from the front is shown. A motorcycle in which only the front wheel WF and the rear wheel WR are in contact with the road surface R at the contact point S travels at a speed equal to or higher than a predetermined value, and while the inertial force of the vehicle body and the rotational inertial force of the front and rear wheels are generated It is easy to keep G upright (solid line in the figure). However, during low-speed traveling where the inertial force of the vehicle body is weakened, the center of gravity G tends to move left and right around the ground point S as shown by the broken line in the figure, that is, the vehicle body tends to tilt in the left-right direction.

  In a normal motorcycle, the occupant performs an operation to return the center of gravity G to an upright state by a steering wheel operation or a weight shift in order to suppress such a lateral inclination (stagger) during low-speed traveling. Among them, the reason why the center of gravity G can be returned to the upright state by the handle operation is that the center of gravity G and the ground contact point S can be moved in accordance with the handle operation as described below. .

  FIG. 10 is a schematic diagram showing how the center of gravity G moves in accordance with the handle operation. In this figure, the front wheel WF and the rear wheel WR are viewed from above the motorcycle in contact with the road surface by the contact points SF and SR. As described above, the front wheel WF of the motorcycle is attached to the front fork that rotates around the head pipe H of the body frame, and is steered by turning the handle 5 attached to the top of the front fork left and right. can do. Usually, the head pipe H is disposed on the rear side of the vehicle body from the ground point SF of the front wheel WF. For this reason, when the steering wheel 5 is steered left and right, the head pipe H moves left and right around the ground contact point SF, and accordingly, the center of gravity G moves in the left and right direction of the vehicle body. This figure shows a state where the position of the center of gravity G has moved to the right by turning the handle 5 to the left.

  In a motorcycle having such vehicle body characteristics, the position of the center of gravity G can be moved left and right by steering the handle 5. Therefore, for example, when the vehicle body starts to lean to the left, that is, when the center of gravity G starts to move to the left in the vehicle width direction, the position of the center of gravity G that has started to move by turning the handle 5 to the left. Can be returned to the center of the vehicle body.

  FIG. 11 is a schematic diagram showing a process in which the center of gravity G returns to an upright state in accordance with the handle operation. The same reference numerals as those described above denote the same or equivalent parts. In this figure, the state which looked at the vehicle from the front is shown. As described above, the center of gravity G that has started to tilt with respect to the contact point S can be returned to the upright state by moving the contact point S.

  In the figure, (a) shows a state in which the vehicle body is tilted to the right because the front wheel WF contacts the obstacle M during traveling. (B) in the figure shows a state in which the handle 5 is steered to the right side in the same direction as the direction in which the vehicle body is tilted in order to return the tilt to the upright state. In the figure, (c) shows a state in which the front wheel WF rolls along the locus K in the direction in which the handle 5 is turned, and the inclination of the vehicle body is returning to the upright state. In the drawing (d), the ground contact point SF of the front wheel WF is moved by a distance L from the vehicle body center line C in the drawing (a) to the right side of the vehicle body, and the center of gravity G is returned to the upright state. ing.

In the motorcycle steering apparatus according to this embodiment, when the angular velocity ω in the roll direction is detected by the gyro sensor, that is, when it is detected that the vehicle body starts to tilt, the power assist means W1 handles the steering in the tilted direction. 5 is configured so that the position of the center of gravity G and the position of the ground contact point S can be moved to quickly return the vehicle body to an upright state. The steering angle correction torque calculation means 105 of the control unit 100 calculates a steering angle correction torque T2 for canceling the detected angular velocity ω in the roll direction, and transmits it to the second motor driving force calculation means 106.
When the vehicle speed V is equal to or lower than the predetermined value and the angular velocity ω in the roll direction is equal to or higher than the predetermined value, the control unit 100 increases the assist force applied to the second motor M2 in a direction to return the position of the center of gravity G of the vehicle body to the vehicle body center. To control. As a result, it is possible to reduce the wobbling of the vehicle body particularly in the low speed range, and to improve the stability and mobility of the motorcycle in all speed ranges.

  According to the configuration of the wobbling reduction control according to the present embodiment, it is possible to perform fully automatic control that is executed based on each sensor output regardless of the operation of the occupant. However, the wobbling does not occur until the steering force by the occupant is applied. It may be configured to execute semi-automatic control in which the reduction is reduced.

  FIG. 12 is a block diagram illustrating a configuration of a control unit of the steering apparatus according to the second embodiment of the present invention. The same reference numerals as those described above denote the same or equivalent parts. The direction in which the control unit 100 shown in the first embodiment turns the steering wheel 5 and the magnitude of the steering force during the fluctuation reduction control are determined in advance as an ideal operation for suppressing the fluctuation of the vehicle body in the shortest time. It can be said that it was embodied based on maps and the like. However, normally, it can be assumed that a motorcycle occupant has the ability to perform an appropriate steering operation to suppress wobbling of the vehicle body. In this case, for example, even in a vehicle that requires a large steering force due to its large weight, it is easy to reduce the fluctuation of the vehicle body by providing the auxiliary steering force so that the front wheels are steered as the passenger intends. It is thought that a simple vehicle can be obtained.

  The steering device according to the second embodiment of the present invention is based on the values of the input torque Mz to the steering wheel and the vehicle speed V without considering the angular velocity ω in the roll direction in view of the characteristics of the motorcycle as described above. 2 The motor M2 is driven.

  The control unit 200 includes an actual steering ratio detection unit 92 that detects a steering ratio j that is a ratio between the rotation angle of the handle 5 and the steering angle of the front wheel WF, and a vehicle speed detection unit 91 that detects the vehicle speed V of the motorcycle. Information from an input torque detecting means (torque sensor) 48 for detecting an input torque (Mz) generated when the occupant steers the steering wheel 5 is input. The control unit 200 is configured to control the second motor M2 based on the values of the vehicle speed V and the input torque Mz, while controlling the first motor M1 based on the values of the vehicle speed V and the steering ratio j. ing.

  The target steering ratio calculation unit 201 calculates the target steering ratio J based on the vehicle speed V detected by the vehicle speed detection unit 91. This calculation process is executed by substituting the vehicle speed V into a predetermined function (J = f (V)).

  The first motor drive amount calculation means 202 calculates the first motor drive amount p1 (p1 = | J−j |) based on the difference between the target steering ratio J and the actual steering ratio j. The first motor drive control unit 203 drives the first motor M1 based on the calculated value of the first motor drive amount p1.

  Further, the power assist torque calculating means 204 uses the power assist torque T (T = Mz) based on the vehicle speed V detected by the vehicle speed detecting means 91, the input torque Mz detected by the input torque detecting means 48, and the target steering ratio J. K) is calculated. Here, the assist coefficient k is a function of the target steering ratio J and the vehicle speed V (k = f (J, V)).

  The second motor drive amount calculation means 205 calculates the second motor drive amount p2 based on the power assist torque T. The second motor drive control unit 206 drives the second motor M2 based on the calculated value of the second motor drive amount p2.

  According to the steering apparatus according to the present embodiment, by assisting the steering operation by the occupant to suppress the wobbling of the vehicle body by the power assist means W1, the occupant's intention to operate can be quickly reflected in the steering angle of the front wheel WF. It becomes possible. As a result, it is possible to reduce the operation burden on the occupant and quickly suppress the wobbling during low-speed traveling, while the main body of the steering wheel operation is always the occupant.

  The shape and arrangement of the front fork, top bridge, bottom bridge, body frame, support case, input torque detection means, roll angular velocity detection means, vehicle speed detection means and actual steering ratio detection means structure and arrangement, steering ratio variable means, and The form of the drive mechanism of the power assist means is not limited to the above embodiment, and various changes can be made. Further, the function for calculating the target steering ratio and the power assist torque, the calculation method of the steering angle correction torque, the set value of the assist coefficient, and the like can be appropriately changed according to the form of the vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 2a ... Main frame, 4 ... Front fork, 5 ... Handlebar, 16 ... Top bridge, 17 ... Bottom bridge, 18 ... Support case, 30 ... Steering device for motorcycle, 31 ... Upper housing 32. Lower housing 40 Input shaft 48 Torque sensor (input torque detection means) 66 Output shaft 91 Vehicle speed detection means 92 Actual steering ratio detection means 93 Roll angular velocity detection means DESCRIPTION OF SYMBOLS 100 ... Control part 101 ... Target steering ratio calculation means 102 ... First motor drive amount calculation means 103 ... First motor drive control part 105 ... Steering angle correction torque calculation means 104 ... Power assist torque calculation means 106: second motor drive amount calculation means, 107: second motor drive control unit, M1: first motor, M2: second motor, S1: slider Steering ratio varying means), W1 ... the worm wheel (power-assisted means)

Claims (4)

A pair of left and right front forks (4) for pivotally supporting the front wheel (WF) is held by a top bridge (16) and a bottom bridge (17) located on the vehicle body lower side of the top bridge (16), In a steering device (30) for a motorcycle that supports the front fork (4) in a steerable manner with respect to a vehicle body frame (2),
Power assist means (W1) for providing an auxiliary steering force by the second motor (M2) according to the input torque (Mz) input to the handle (5) operated by the occupant;
Vehicle speed detection means (92) for detecting the vehicle speed (V);
Input torque detection means (48) for detecting the input torque (Mz);
Steering ratio detection means (92) for detecting a steering ratio (j) which is a ratio of a rotation angle of the handle (5) and a steering angle of the front wheel (WF);
Roll angular velocity detection means (93) for detecting the angular velocity (ω) of the vehicle body in the roll direction;
A control unit (100) for controlling the second motor (M2),
The control unit (100) controls the second motor (M2) based on the vehicle speed (V), the input torque (Mz), and the angular velocity (ω) in the roll direction ,
Based on a function of the vehicle speed (V), the input torque (Mz), and the steering ratio (j) (T1 = Mz · k (k = f (j, V))), power assist as the auxiliary steering force Power assist torque calculating means (104) for obtaining torque (T1);
Steering angle correction torque calculation means (105) for obtaining a steering angle correction torque (T2) for canceling the angular velocity (ω) in the roll direction based on a vehicle speed-angular velocity map that changes according to the vehicle speed (V). Equipped,
The second motor (M2) is controlled based on a sum of the power assist torque (T1) and the steering angle correction torque (T2),
When the vehicle speed (V) is equal to or less than a predetermined value and the angular velocity (ω) in the roll direction is equal to or greater than a predetermined value, the control unit (100) provides assist force in a direction to return the position of the center of gravity (G) of the vehicle body to the vehicle body center. A steering apparatus for a motorcycle characterized by being enlarged . Steering ratio variable means (S1) for arbitrarily changing the steering ratio (j) by the first motor (M1),
The controller (100) is configured to control the first motor (based on a difference between a target steering ratio (J) and the steering ratio (j) obtained by a function (J = f (V)) of the vehicle speed (V). The steering apparatus for a motorcycle according to claim 1 , wherein M1) is controlled. (Old claim 4 + 5)
A pair of left and right front forks (4) for pivotally supporting the front wheel (WF) is held by a top bridge (16) and a bottom bridge (17) located on the vehicle body lower side of the top bridge (16), In a steering device (30) for a motorcycle that supports the front fork (4) in a steerable manner with respect to a vehicle body frame (2),
Power assist means (W1) for providing an auxiliary steering force by the second motor (M2) according to the input torque (Mz) input to the handle (5) operated by the occupant;
Vehicle speed detection means (92) for detecting the vehicle speed (V);
Input torque detection means (48) for detecting the input torque (Mz);
Steering ratio detection means (92) for detecting a steering ratio (j) which is a ratio of a rotation angle of the handle (5) and a steering angle of the front wheel (WF);
Roll angular velocity detection means (93) for detecting the angular velocity (ω) of the vehicle body in the roll direction;
A control unit (200) for controlling the second motor (M2),
The control unit (200) controls the second motor (M2) based on the values of the vehicle speed (V) and the input torque (Mz) ,
Based on a function of the vehicle speed (V), the input torque (Mz), and the steering ratio (j) (T = Mz · k (k = f (j, V))), power assist as the auxiliary steering force Power assist torque calculating means (204) for determining torque (T),
The steering apparatus for a motorcycle, wherein the second motor (M2) is controlled based on a value of the power assist torque (T) . Steering ratio variable means (S1) for arbitrarily changing the steering ratio (j) by the first motor (M1),
The controller (200) is configured to control the first motor (J) based on a difference between a target steering ratio (J) and the steering ratio (j) obtained by a function (J = f (V)) of the vehicle speed (V). The motorcycle steering apparatus according to claim 3 , wherein M1) is controlled.

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