LEANING VEHICLE

Abstract

A leaning vehicle, including a vehicle body leaning left and right when the leaning vehicle turns left and right, respectively, left and right steerable front wheels that are each steerable by a turning manipulation input device, a rear wheel unsteerable by the turning manipulation input device, a lean actuator that causes the vehicle body to lean, and a control device configured to control the lean actuator. When the left and right steerable front wheels are steered in a first direction while the leaning vehicle is traveling straight backward with the vehicle body being upright, the lean actuator causes the leaning vehicle to turn in the first direction, with a front portion thereof moving farther in a second direction than a rear portion, such that the vehicle body kept upright, where the first and second directions are respectively one and the other of the left and right directions.

Claims

1. A leaning vehicle, comprising: a vehicle body, which leans left when the leaning vehicle turns in a left direction, and leans right when the leaning vehicle turns in a right direction, while the leaning vehicle is traveling forward; a turning manipulation input device; a left steerable front wheel and a right steerable front wheel, each of which is steerable by manipulation of the turning manipulation input device; a rear wheel that is unsteerable by the manipulation of the turning manipulation input device; a lean actuator that causes the vehicle body to lean; and a control device configured to control the lean actuator, such that when the left steerable front wheel and the right steerable front wheel are steered in a first direction by the manipulation of the turning manipulation input device while the leaning vehicle is traveling straight backward with the vehicle body being upright, the leaning vehicle turns in the first direction, with a front portion of the leaning vehicle moving farther in a second direction than a rear portion of the leaning vehicle, while the leaning vehicle is traveling backward with the vehicle body kept upright, wherein the first direction and the second direction are respectively the left direction and the right direction, or respectively the right direction and the left direction.

2. The leaning vehicle according to claim 1, wherein the control device so controls the lean actuator without regard to a speed of the leaning vehicle.

3. The leaning vehicle according to claim 1, wherein the control device controls the lean actuator to keep an upward-downward direction of the leaning vehicle vertical, when the leaning vehicle is on a road surface that is inclined in a left-right direction of the leaning vehicle.

4. The leaning vehicle according to claim 1, wherein a position at which a steering axis of the left steerable front wheel and a steering axis of the right steerable front wheel intersect a road surface is located farther in a forward direction than a position at which the left steerable front wheel or the right steerable front wheel is in contact with the road surface.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 A diagram showing a left view of a leaning vehicle according to an embodiment of the present teaching as well as a block diagram of a leaning control system included in the leaning vehicle.

[0025] FIG. 2 A flowchart showing an operation control on a lean actuator, which is performed by a control device.

[0026] FIG. 3 An illustrative diagram for illustrating a lean angle of a vehicle body in a case where a road surface is inclined in a left-right direction of the leaning vehicle.

DESCRIPTION OF EMBODIMENTS

[0027] In the following, details of a leaning vehicle according to an embodiment of the present teaching will be described with reference to the drawings. The embodiment described below is just an example. The present teaching should never be construed in a limited way by the embodiment described below.

[0028] Referring to FIG. 1, a leaning vehicle 10 according to the embodiment of the present teaching will be described. FIG. 1 is a diagram showing a left view of the leaning vehicle 10 as well as a block diagram of a leaning control system included in the leaning vehicle 10.

[0029] In this Description, various directions in relation to the leaning vehicle 10 are defined as follows.

[0030] The forward (front) direction of the leaning vehicle 10 is defined as forward direction F. The backward (rear) direction of the leaning vehicle 10 is defined as backward direction B. The left direction of the leaning vehicle 10 is defined as left direction L. The right direction of the leaning vehicle 10 is defined as right direction R. The upward (upper) direction of the leaning vehicle 10 is defined as upward direction U. The downward (lower) direction of the leaning vehicle 10 is defined as downward direction D. The forward-backward (front-rear) direction of the leaning vehicle 10 is defined as forward-backward direction FB. The left-right direction of the leaning vehicle 10 is defined as left-right direction LR. The upward-downward (up-down) direction of the leaning vehicle 10 is defined as upward-downward direction UD. It should be noted that forward, backward, upward, downward, left, and right of the leaning vehicle 10 are forward, backward, upward, downward, left, and right as viewed by a rider sitting on a seat 202 of the leaning vehicle 10.

[0031] In the leaning vehicle 10, the forward (front) direction of a vehicle body 20 is defined as forward direction f. The backward (rear) direction of the vehicle body 20 is defined as backward direction b. The left direction of the vehicle body 20 is defined as left direction 1. The right direction of the vehicle body 20 is defined as right direction r. The upward (upper) direction of the vehicle body 20 is defined as upward direction u. The downward (lower) direction of the vehicle body 20 is defined as downward direction d. The forward-backward (front-rear) direction of the vehicle body 20 is defined as forward-backward direction fb. The left-right direction of the vehicle body 20 is defined as left-right direction lr. The upward-downward (up-down) direction of the vehicle body 20 is defined as upward-downward direction ud.

[0032] In the leaning vehicle 10, the vehicle body 20 is able to lean in the left direction L or the right direction R. When the vehicle body 20 leans in the left direction L or the right direction R, the upward-downward direction ud and the left-right direction lr of the vehicle body 20 are not coincident with the upward-downward direction UD and the left-right direction LR of the leaning vehicle 10, respectively. When the vehicle body 20 is upright, the upward-downward direction ud and the left-right direction lr of the vehicle body 20 are coincident with the upward-downward direction UD and the left-right direction LR of the leaning vehicle 10.

[0033] The leaning vehicle 10, in forward traveling, turns in the left direction L with the vehicle body 20 leaning in the left direction L, and turns in the right direction R with the vehicle body 20 leaning in the right direction R. The leaning vehicle 10 includes the vehicle body 20, plural wheels 30, a power unit 40, a turning manipulation input device 50, a lean actuator 60, a steering actuator 70, and a control device 100. These will be described below.

[0034] The vehicle body 20 leans in the left direction L when the leaning vehicle 10 turns in the left direction L, and leans in the right direction R when the leaning vehicle 10 turns in the right direction R. The vehicle body 20 includes a vehicle body frame 201 and the seat 202.

[0035] The vehicle body frame 201 supports the power unit 40. The power unit 40 includes an engine as a drive source, a transmission, and the like. The drive source may be either an electric motor or a combination of an engine and an electric motor. The seat 202 is where the rider of the leaning vehicle 10 sits.

[0036] The vehicle body frame 201 includes a head pipe 2011. The head pipe 2011 receives a steering shaft 203 therein. The steering shaft 203 is not mechanically connected to a handlebar 501. Thus, a turning manipulation that the rider performs on the handlebar 501 is not mechanically transmitted to the steering shaft 203.

[0037] The vehicle body 20 supports the plural wheels 30. The plural wheels 30 lean in the left direction L together with the vehicle body 20 when the leaning vehicle 10 turns in the left direction L, and lean in the right direction R together with the vehicle body 20 when the leaning vehicle 10 turns in the right direction R. The plural wheels 30 include a pair of left and right steerable front wheels 30F and a rear wheel 30R.

[0038] The pair of left and right steerable front wheels 30F comprises a left steerable front wheel and a right steerable front wheel, which are arranged side by side in the left-right direction LR. The pair of left and right steerable front wheels 30F is steered by the rider of the leaning vehicle 10 manipulating the turning manipulation input device 50. When viewed in the left direction L or the right direction R of the leaning vehicle 10, a position P1 at which a steering central axis line CL of the pair of left and right steerable front wheels 30F intersects a road surface RS is located farther in the forward direction than a position P2 at which each of the left and right paired steerable front wheels 30F is in contact with the road surface RS. The pair of left and right steerable front wheels 30F leans in the left direction L together with the vehicle body 20 when the leaning vehicle 10 turns in the left direction L, and leans in the right direction R together with the vehicle body 20 when the leaning vehicle 10 turns in the right direction R. A lean mechanism 2041 for leaning the pair of left and right steerable front wheels 30F is a lean mechanism that adopts a parallelogram link system, for example. The pair of left and right steerable front wheels 30F is supported by the vehicle body frame 201 via a suspension device 204 including the lean mechanism 2041.

[0039] The rear wheel 30R is disposed farther in the backward direction with respect to the forward-backward direction FB than the pair of left and right steerable front wheels 30F. The rear wheel 30R leans in the left direction L together with the vehicle body 20 when the leaning vehicle 10 turns in the left direction L, and leans in the right direction R together with the vehicle body 20 when the leaning vehicle 10 turns in the right direction R. The rear wheel 30 is supported by the vehicle body frame 201 via a swing arm. The rear wheel 30 is rotated by receiving power from the power unit 40. This causes the leaning vehicle 10 to travel. The rear wheel 30R is not steered even though the rider of the leaning vehicle 10 manipulates the turning manipulation input device 50.

[0040] The turning manipulation input device 50 is manipulated by the rider of the leaning vehicle 10 in order to turn the leaning vehicle 10. The turning manipulation input device 50 includes the handlebar 501 as a manipulated member that the rider can manipulate.

[0041] The turning manipulation input device 50 is configured such that a turning manipulation performed by the rider of the leaning vehicle 10 is not mechanically transmitted to the pair of left and right steerable front wheels 30F and thus does not cause the pair of left and right steerable front wheels 30F to be steered about the central axis line CL. More specifically, the handlebar 501 is not mechanically connected to the pair of left and right steerable front wheels 30F. That is, no power is transmitted from the handlebar 501 to the pair of left and right steerable front wheels 30F.

[0042] The turning manipulation input device 50, for example, detects a direction of a manipulation on the handlebar 501 and the amount of the manipulation on the handlebar 501, and inputs the detected direction and amount of the manipulation on the handlebar 501 to the control device 100. For the detection of the direction and amount of the manipulation on the handlebar 501, an encoder or the like is used, for example.

[0043] The lean actuator 60 leans the vehicle body 20. The lean actuator 60 is, for example, an electric motor capable of rotating an output member in a normal direction and a reverse direction, the output member being mechanically connected to a member included in the lean mechanism 2041.

[0044] The lean actuator 60 applies a torque to the member included in the lean mechanism 2041, based on a turning manipulation received by the turning manipulation input device 50. The member to which the torque is applied by the lean actuator 60 rotates relative to the vehicle body frame 201. This involves an operation of the lean mechanism 2041. Accordingly, the left and right paired steerable front wheels 30F change their respective positions relative to the vehicle body frame 201 with respect to the upward-downward direction ud. Consequently, the vehicle body frame 201 leans in the left direction L or the right direction R. That is, the vehicle body 20 leans in the left direction L or the right direction R.

[0045] The steering actuator 70 steers each of the left and right paired steerable front wheels 30F, based on a manipulation that the rider of the leaning vehicle 10 performs on the turning manipulation input device 50. The steering actuator 70, for example, rotates an output member that is mechanically connected to the steering shaft 203. The steering actuator 70 is, for example, an electric motor capable of rotating the output member mechanically connected to the steering shaft 203 in a normal direction and a reverse direction.

[0046] The steering actuator 70 rotates the steering shaft 203 based on a turning manipulation received by the turning manipulation input device 50. The rotation of the steering shaft 203 is transmitted to the pair of left and right steerable front wheels 30F via a tie rod 205. As a result, each of the left and right paired steerable front wheels 30F is steered. The steering actuator 70 may also be used as a damper for suppressing swinging of the pair of left and right steerable front wheels 30F in the left-right direction LR while the leaning vehicle 10 is traveling in the backward direction.

[0047] The leaning vehicle 10 is configured to be capable of backward traveling. For example, the engine included in the power unit 40 serves as a backward traveling drive source that outputs power for causing backward traveling of the leaning vehicle 10. With this configuration, the power of the backward traveling drive source is transmitted to the rear wheel 30R via a backward traveling power transmission mechanism. Used as the backward traveling power transmission mechanism is a part of a forward traveling power transmission mechanism that transmits engine power to the rear wheel 30R in forward traveling of the leaning vehicle 10.

[0048] The control device 100 controls the lean actuator 60 and the steering actuator 70 based on a manipulation on the turning manipulation input device 50. In response to a situation where the pair of left and right steerable front wheels 30F is steered in the left direction L based on a manipulation on the turning manipulation input device 50 while the leaning vehicle 10 is traveling straight backward with the vehicle body 20 being upright, the control device 100 controls the lean actuator 60 such that the leaning vehicle 10 turns in the left direction L with a front portion of the leaning vehicle 10 moving in the right direction R more largely than a rear portion of the leaning vehicle 10 while the leaning vehicle 10 is traveling backward with the vehicle body 20 kept upright. In response to a situation where the pair of left and right steerable front wheels 30F is steered in the right direction R based on a manipulation on the turning manipulation input device 50 while the leaning vehicle 10 is traveling straight backward with the vehicle body 20 being upright, the control device 100 controls the lean actuator 60 such that the leaning vehicle 10 turns in the right direction R with the front portion of the leaning vehicle 10 moving in the left direction L more largely than the rear portion of the leaning vehicle 10 while the leaning vehicle 10 is traveling backward with the vehicle body 20 kept upright. Here, it may be possible that the control device 100 keeps the vehicle body 20 upright in the entire vehicle speed region while the leaning vehicle 10 is traveling backward.

[0049] An operation control on the lean actuator 60, which is performed by the control device 100, will be described with reference to FIG. 2. FIG. 2 is a flowchart showing the operation control on the lean actuator 60, which is performed by the control device 100.

[0050] First, in step S11, the control device 100 determines whether or not the turning manipulation input device 50 is manipulated by the rider of the leaning vehicle 10. If the turning manipulation input device 50 is manipulated by the rider of the leaning vehicle 10 (step S11: YES), the control device 100 determines whether or not the leaning vehicle 10 is traveling backward (step S12). If the leaning vehicle 10 is traveling backward (step S12: YES), the control device 100 controls the lean actuator 60 so as to keep the vehicle body 20 upright (step S13). Then, the control device 100 terminates the control.

[0051] If the turning manipulation input device 50 is not manipulated by the rider of the leaning vehicle 10 (step S11: NO), the control device 100 executes the processing of step S13 and subsequent steps. If the leaning vehicle 10 is not traveling backward (step S12: NO), the control device 100 controls the lean actuator 60 so as to lean the vehicle body 20 based on the manipulation on the turning manipulation input device 50 (step S14). Then, the control device 100 terminates the control.

[0052] In the leaning vehicle 10, the vehicle body 20 can be kept upright not only when the leaning vehicle 10 travels straight backward but also when the leaning vehicle 10 turns while traveling backward. This helps the rider of the leaning vehicle 10 in grasping a behavior of the leaning vehicle 10 even when the leaning vehicle 10 is turning while traveling backward. Consequently, it is easy to make the leaning vehicle 10 turn while traveling backward.

[0053] (Variation 1 of Leaning Vehicle 10)

[0054] A variation of the leaning vehicle 10 will be described with reference to FIG. 3. FIG. 3 is an illustrative diagram for illustrating a lean angle α of the vehicle body 20 in a case where the road surface RS is inclined in the left-right direction LR of the leaning vehicle 10.

[0055] In the variation, the control device 100 controls the lean actuator 60 so as to have the upward-downward direction UD of the leaning vehicle 10 closer to verticalness, when the leaning vehicle 10 is present on the road surface RS that has an incline in the left-right direction LR of the leaning vehicle 10. In FIG. 3, the straight line L1 indicates a straight line perpendicular to the road surface RS, the straight line L2 indicates a straight line extending in the upward-downward direction ud of the vehicle body 20, and the straight line L3 indicates a straight line extending in the vertical direction.

[0056] In the variation, the vehicle body 20 can be caused to lean with the inclination of the road surface taken into account.

OTHER EMBODIMENTS

[0057] The embodiment and variation, of which at least either one of description or illustration has been given herein, are for ease of understanding the present disclosure, and not for limiting the concept of the present disclosure. The foregoing embodiment and variation may be altered and/or adapted without departing from the spirit of the present disclosure.

[0058] The spirit encompasses equivalent elements, modifications, omissions, combinations (for example, a combination of a feature of the embodiment and a feature of any variation), adaptations and/or alterations as would be appreciated by those skilled in the art based on the embodiment disclosed herein. The limitations in Claims are to be interpreted broadly based on the language employed in Claims and not limited to embodiments and variations described herein or during the prosecution of the present application. The embodiments and variations are to be construed as non-exclusive. For example, in this Description, the terms “preferably”, “may”, and “possible” are non-exclusive and mean “preferably, but not limited to”, “may, but not limited to”, and “possibly, but not limited to”, respectively.

[0059] For example, in the foregoing embodiment, the turning manipulation input device 50 may be configured such that a manipulation performed by the rider of the leaning vehicle 10 is mechanically transmitted to the pair of left and right steerable front wheels 30F and thus steers the pair of left and right steerable front wheels 30F. In such a configuration, a manipulation on the turning manipulation input device 50 that is mechanically transmitted to the pair of left and right steerable front wheels 30F may be assisted by an actuator.

REFERENCE SIGNS LIST

[0060] 10 leaning vehicle [0061] 20 vehicle body [0062] 30F steerable front wheel [0063] 30R rear wheel [0064] 50 turning manipulation input device [0065] 60 lean actuator [0066] 100 control device [0067] RS road surface [0068] P1 position [0069] P2 position [0070] CL steering central axis line