Lean vehicle

Abstract

To provide a lean vehicle that is able to control driving forces of a left front wheel and a right front wheel independently of each other.SOLUTION: A lean vehicle 1 includes: a vehicle body frame 10 having a head pipe 12; a left front wheel 20L; a right front wheel 20R; a steering shaft 31 rotatable leftwards and rightwards together with the left front wheel 20L and the right front wheel 20R; a handlebar 30; a link mechanism 40 connecting the vehicle body frame 10, the left front wheel 20L, and the right front wheel 20R so that these are capable of leaning together; a left in-wheel motor 50L provided in the left front wheel 20L; and a right in-wheel motor 50R provided in the right front wheel 20R.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lean vehicle that has left and right front wheels and whose body frame tilts when turning left or right. [Background technology]

[0002] Conventionally, there has been known a lean vehicle that has a left front wheel and a right front wheel and whose body frame tilts when turning left or right, as described in, for example, Patent Document 1. When turning left or right, a rider turns the lean vehicle by steering the handlebars. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-51631 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a lean vehicle, if the drive forces of the left and right front wheels could be appropriately changed independently of each other, various controls would be possible.

[0005] For example, many riders prefer a constant force for holding the handlebars while turning (hereinafter referred to as holding force). However, the holding force changes depending on the speed and turning radius of the lean vehicle. It is difficult to design a lean vehicle so that the holding force is always constant regardless of the speed and turning radius. In addition, some riders may prefer to change the holding force according to their own preferences while turning, rather than keeping it constant. In conventional lean vehicles, it is not possible to keep the holding force constant or to change the holding force according to the rider's preferences. However, if the driving forces of the left front wheel and the right front wheel can be controlled independently of each other, it becomes possible to control the holding force, such as changing it according to the rider's preferences.

[0006] An object of the present invention is to provide a lean vehicle in which the drive forces of the left and right front wheels can be controlled independently of each other. [Means for solving the problem]

[0007] The lean vehicle disclosed herein comprises a body frame having a head pipe, a left front wheel positioned to the left of the head pipe, a right front wheel positioned to the right of the head pipe, a steering shaft supported by the head pipe and rotatable left and right together with the left and right front wheels, a handlebar fixed to the steering shaft and operated by a rider, a link mechanism connecting the body frame, the left front wheel, and the right front wheel so that the body frame, the left front wheel, and the right front wheel can tilt with respect to the ground, a left in-wheel motor provided on the left front wheel, and a right in-wheel motor provided on the right front wheel.

[0008] According to the above-described lean vehicle, the left front wheel can be driven by the left in-wheel motor, and the right front wheel can be driven by the right in-wheel motor, so that the driving forces of the left front wheel and the right front wheel can be controlled independently of each other by controlling the left in-wheel motor and the right in-wheel motor.

[0009] The lean vehicle may include a bank angle sensor that detects a bank angle of the vehicle body frame, and a control device that is communicatively connected to the bank angle sensor and controls the left in-wheel motor and the right in-wheel motor based on the bank angle detected by the bank angle sensor.

[0010] This makes it possible to control the drive forces of the left and right front wheels independently of each other, based on the bank angle of the body frame.

[0011] The control device may be configured to be able to adjust a difference between the drive force of the left front wheel and the drive force of the right front wheel during turning.

[0012] As a result, when turning, the control device can adjust the difference between the driving force of the left front wheel and the driving force of the right front wheel, thereby adjusting the holding force of the handlebars when turning.

[0013] The lean vehicle may include an input device operated by a rider. The control device may be communicatively connected to the input device and configured to adjust the difference between the driving force of the left front wheel and the driving force of the right front wheel during a turn based on an input value to the input device by the rider.

[0014] This allows the rider to input the desired gripping force for the handlebars by operating the input device, and the control device can control the gripping force during cornering according to the rider's preference.

[0015] When a lean vehicle turns, one of the left front wheel and the right front wheel becomes an outer wheel and the other becomes an inner wheel. The control device may be configured to be capable of executing counter steering control to make the driving force of the outer wheel greater than the driving force of the inner wheel.

[0016] The control device may be configured to be capable of executing steering control to make the driving force of the outer wheel smaller than the driving force of the inner wheel.

[0017] The lean vehicle may include a bank angle sensor that detects a bank angle of the vehicle body frame, a vehicle speed sensor that detects vehicle speed, and a control device that is communicatively connected to the bank angle sensor and the vehicle speed sensor and controls the left in-wheel motor and the right in-wheel motor based on the bank angle and the vehicle speed.

[0018] This makes it possible to control the drive forces of the left and right front wheels independently of each other based on the bank angle and vehicle speed.

[0019] The control device may be configured to execute control to reduce the driving force of the outer wheel and / or increase the driving force of the inner wheel when the bank angle is equal to or greater than a threshold value.

[0020] This allows the bank angle to be automatically made shallower when the rider makes a turn if the bank angle becomes too steep, without the rider having to hold the handlebars with increased force. The rider can raise the frame relatively easily.

[0021] The control device may be configured to execute anti-toppling control to reduce the driving force of the outer wheel and / or increase the driving force of the inner wheel when the vehicle speed is equal to or greater than a first threshold and the bank angle is equal to or greater than a second threshold.

[0022] This makes it possible to prevent the lean vehicle from tipping over when making a sharp turn at a relatively high speed.

[0023] The lean vehicle may include an angular velocity sensor that detects an angular velocity of a bank angle of the vehicle body frame. The control device may be configured to execute anti-toppling control to reduce the driving force of the outer wheels and / or increase the driving force of the inner wheels when the vehicle speed is equal to or greater than a first threshold value and the angular velocity of the bank angle is equal to or greater than a third threshold value.

[0024] This makes it possible to prevent the lean vehicle from tipping over when making a sharp turn at a relatively high speed.

[0025] The lean vehicle may be equipped with a forward sensor that detects an object in front. The "object" may include another vehicle (hereinafter, referred to as a preceding vehicle) traveling in front of the lean vehicle, a driving lane marked on a road, etc. The control device may be configured to execute notification control that alternates between a first state in which the driving force of the right front wheel is greater than the driving force of the left front wheel and a second state in which the driving force of the left front wheel is greater than the driving force of the right front wheel when the forward sensor detects the object, the vehicle speed is equal to or greater than a fourth threshold, and the bank angle is equal to or less than a fifth threshold.

[0026] As a result, when a predetermined object is detected ahead while the lean-in vehicle is traveling at a relatively high speed, the first state and the second state are repeated to notify the rider. For example, when a preceding vehicle is detected while the lean-in vehicle is traveling at a relatively high speed, the rider who receives the notification can avoid a collision with the preceding vehicle by decelerating the vehicle, etc. Also, when the lean-in vehicle approaches the center line, the center line is detected ahead. The rider who receives the notification can operate the handlebars to prevent the lean-in vehicle from crossing the center line. Effect of the Invention

[0027] According to the present invention, it is possible to provide a lean vehicle in which the drive forces of the left and right front wheels can be controlled independently of each other. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a left side view of a lean vehicle according to one embodiment. [Diagram 2] FIG. 2 is a front view of the front part of a lean vehicle. [Diagram 3] FIG. 3 is a left side view of the front part of the lean vehicle. [Figure 4] FIG. 4 is a plan view of the front of a lean vehicle. [Diagram 5] FIG. 5 is a plan view of the front part of a lean vehicle during steering. [Figure 6] FIG. 6 is a front view of the front part of a lean vehicle when leaning. [Figure 7] FIG. 7 is a front view of the front of a lean vehicle when leaning and steering. [Figure 8] FIG. 8 is a block diagram of the control system for a lean vehicle. [Figure 9] FIG. 9 is a flowchart of the first control. [Figure 10]Fig. 10(a) is a graph showing the relationship between the input value and the base factor for the first control, Fig. 10(b) is a graph showing the relationship between the vehicle speed and the speed factor for the first control, and Fig. 10(c) is a graph showing the relationship between the bank angle and the bank angle factor for the first control. [Figure 11] Fig. 11(a) is a graph showing a change in target torque for the right front wheel regarding the first control, and Fig. 11(b) is a graph showing a change in target torque for the left front wheel regarding the first control. [Figure 12] FIG. 12 is a flowchart of the second control. [Figure 13] Fig. 13(a) is a graph showing the relationship between the input value and the base factor for the second control. Fig. 13(b) is a graph showing the relationship between the vehicle speed and the speed factor for the second control. Fig. 13(c) is a graph showing the relationship between the bank angular velocity and the bank angular velocity factor for the second control. Fig. 13(d) is a graph showing the relationship between the bank angle and the bank angle factor for the second control. [Figure 14] Fig. 14(a) is a graph showing the relationship between the input value and the base factor for the third control. Fig. 14(b) is a graph showing the relationship between the vehicle speed and the speed factor for the third control. Fig. 14(c) is a graph showing the relationship between the bank angular velocity and the bank angular velocity factor for the third control. Fig. 14(d) is a graph showing the relationship between the bank angle and the bank angle factor for the third control. [Figure 15] FIG. 15 is a flowchart of the fourth control. [Figure 16] Fig. 16(a) is a graph showing the relationship between the input value and the base factor for the fourth control, Fig. 16(b) is a graph showing the relationship between the vehicle speed and the speed factor for the fourth control, and Fig. 16(c) is a graph showing the relationship between the bank angle and the bank angle factor for the fourth control. [Figure 17] Fig. 17(a) is a graph showing the change in adjustment torque for the right front wheel, and Fig. 17(b) is a graph showing the change in adjustment torque for the left front wheel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of a lean vehicle will be described with reference to the drawings. Fig. 1 is a left side view of a lean vehicle 1 according to one embodiment.

[0030] In the following description, unless otherwise specified, the terms front, rear, left, right, top, and bottom refer to the front, rear, left, right, top, and bottom as seen by a virtual rider seated on the seat 2 when the lean-mounted vehicle 1, with no rider and no luggage on it, is stopped in an upright position on a horizontal plane. Note that the state in which the lean-mounted vehicle 1 is upright on a horizontal plane means a state in which the body frame 10, which will be described later, is not inclined relative to the horizontal plane (see FIG. 2). In the drawings, F, B, L, R, U, and D respectively represent the front, rear, left, right, top, and bottom.

[0031] Fig. 2 is a front view of the front part of the lean vehicle 1. Fig. 3 is a left side view of the front part of the lean vehicle 1. Fig. 4 is a plan view of the front part of the lean vehicle 1. Fig. 5 is a plan view of the front part of the lean vehicle 1 when steering. Fig. 6 is a front view of the front part of the lean vehicle 1 when leaning. Fig. 7 is a front view of the front part of the lean vehicle 1 when leaning and steering.

[0032] As shown in Fig. 1, the lean vehicle 1 includes a body frame 10, a seat 2 supported by the body frame 10, a left front wheel 20L, a right front wheel 20R (see Fig. 2), a rear wheel 28, and a power unit 4. As shown in Fig. 2, the lean vehicle 1 includes a handlebar 30, a link mechanism 40 that connects the body frame 10, the left front wheel 20L, and the right front wheel 20R, a left in-wheel motor 50L provided on the left front wheel 20L, and a right in-wheel motor 50R provided on the right front wheel 20R. Note that the left in-wheel motor 50L and the right in-wheel motor 50R are not shown in Figs. 3 to 7.

[0033] As shown in Fig. 4, the body frame 10 includes a head pipe 12 and a link pipe 14 disposed forward of the head pipe 12. The head pipe 12 supports a steering shaft 31 fixed to a handlebar 30 so as to be rotatable left and right. The link pipe 14 supports a steering shaft 32 so as to be rotatable left and right.

[0034] As shown in FIG. 1, the power unit 4 is supported by a body frame 10. The body frame 10 has a power unit support portion 16 that supports the power unit 4. In addition, the front end of a rear arm 29 is connected to the power unit 4 so as to be able to rotate up and down. A rear wheel 28 is attached to the rear end of the rear arm 29. The power unit 4 is connected to the rear wheel 28. The power unit 4 has a power source formed of an internal combustion engine or an electric motor. The power unit 4 drives the rear wheel 28.

[0035] 4, the left front wheel 20L is disposed to the left of the head pipe 12. The right front wheel 20R is disposed to the right of the head pipe 12. The left front wheel 20L and the right front wheel 20R are rotatable left and right together with the steering shaft 31.

[0036] 2, the left in-wheel motor 50L is connected to the left front wheel 20L. The right in-wheel motor 50R is connected to the right front wheel 20R. The left in-wheel motor 50L drives the left front wheel 20L, and the right in-wheel motor 50R drives the right front wheel 20R.

[0037] The lean vehicle 1 includes a left shock absorber 22L and a right shock absorber 22R. As shown in FIG. 3, the left shock absorber 22L is a so-called telescopic shock absorber. The left shock absorber 22L includes a pair of front and rear telescopic elements 24. Each telescopic element 24 includes an outer tube 24A and an inner tube 24B inserted into the outer tube 24A. As shown in FIG. 2, the right shock absorber 22R is disposed symmetrically to the left shock absorber 22L. The right shock absorber 22R includes a similar configuration to the left shock absorber 22L. The right shock absorber 22R also includes a pair of front and rear telescopic elements 24.

[0038] As shown in FIG. 2, the lean vehicle 1 includes a left bracket 23L, a left bracket 25L, a right bracket 23R, and a right bracket 25R. As shown in FIG. 3, the upper end of the telescopic element 24 of the left shock absorber 22L is fixed to the left bracket 23L. The lower end of the telescopic element 24 of the left shock absorber 22L is fixed to the left bracket 25L. The left front wheel 20L is supported by the left bracket 25L. As shown in FIG. 2, the upper end of the telescopic element 24 of the right shock absorber 22R is fixed to the right bracket 23R. The lower end of the telescopic element 24 of the right shock absorber 22R is fixed to the right bracket 25R. The right front wheel 20R is supported by the right bracket 25R.

[0039] As shown in FIG. 4, the lean vehicle 1 includes a steering force transmission mechanism 6. The steering force transmission mechanism 6 includes a handlebar 30, a steering shaft 31, and a steering shaft 32 disposed forward of the steering shaft 31. The steering shaft 31 is supported by the head pipe 12 so as to be rotatable left and right. The steering shaft 32 is supported by the link pipe 14 so as to be rotatable left and right. The handlebar 30 is fixed to the steering shaft 31. A right grip 33R and a left grip 33L are attached to the handlebar 30. The right grip 33R is rotatable relative to the handlebar 30, and constitutes an accelerator grip for the rider to operate the power unit 4. The steering shaft 31 and the steering shaft 32 are connected by a connecting member 80. The connecting member 80 connects the steering shaft 31 and the steering shaft 32 so as to rotate together.

[0040] The link mechanism 40 is a four-parallel link (also called a parallelogram link) type link mechanism. As shown in FIG. 2, the link mechanism 40 has an upper cross member 41, a lower cross member 42, and a lower cross member 45 (see FIG. 3) that extend left and right, and a left side member 43 and a right side member 44 that extend up and down. The link mechanism 40 is supported by a steering shaft 32 that is supported by the link pipe 14 so as to be rotatable left and right. The link mechanism 40 is rotatable left and right relative to the steering shaft 32 (see FIG. 5). The link mechanism 40 is configured not to rotate together with the steering shaft 32 even when the steering shaft 32 rotates left and right.

[0041] The upper cross member 41 is connected to the link pipe 14 by a connecting shaft 41C, to the left side member 43 by a connecting shaft 41L, and to the right side member 44 by a connecting shaft 41R. The upper cross member 41 is connected to each of the link pipe 14, the left side member 43, and the right side member 44 so as to be rotatable around an axis extending in the front-rear direction.

[0042] 4, the lower cross member 42 is disposed in front of the link pipe 14. The lower cross member 45 is disposed rearward of the link pipe 14. The lower cross member 42 and the lower cross member 45 are connected by a connecting block 46.

[0043] 2, the lower cross member 42 is connected to the link pipe 14 by a connecting shaft 42C, to the left side member 43 by a connecting shaft 42L, and to the right side member 44 by a connecting shaft 42R. The lower cross member 42 is connected to each of the link pipe 14, the left side member 43, and the right side member 44 so as to be rotatable around an axis extending in the front-rear direction.

[0044] A lower portion of the left side member 43 is connected to the left bracket 23L. The left bracket 23L is connected to the left side member 43 so as to be rotatable about an axis extending in the vertical direction. A lower portion of the right side member 44 is connected to the right bracket 23R. The right bracket 23R is connected to the right side member 44 so as to be rotatable about an axis extending in the vertical direction.

[0045] As shown in FIGS. 2 and 4, the steering force transmission mechanism 6 has an intermediate transmission plate 61, a left transmission plate 62, a right transmission plate 63, an intermediate joint 64, a left joint 65, a right joint 66, and a tie rod 67.

[0046] The intermediate transmission plate 61 is connected to a lower portion of the steering shaft 32. The intermediate transmission plate 61 extends forward from the steering shaft 32 (see FIG. 4). The left transmission plate 62 is connected to the left bracket 23L. The right transmission plate 63 is connected to the right bracket 23R.

[0047] As shown in FIG. 4, the intermediate joint 64 is connected to a front portion of the intermediate transmission plate 61. The intermediate joint 64 is connected to the intermediate transmission plate 61 so as to be rotatable about an axis extending in the vertical direction. The left joint 65 is connected to a front portion of the left transmission plate 62. The left joint 65 is connected to the left transmission plate 62 so as to be rotatable about an axis extending in the vertical direction. The right joint 66 is connected to a front portion of the right transmission plate 63. The right joint 66 is connected to the right transmission plate 63 so as to be rotatable about an axis extending in the vertical direction.

[0048] The tie rod 67 is connected to each of the intermediate joint 64, the left joint 65, and the right joint 66 so as to be rotatable about an axis extending in the front-rear direction.

[0049] In this manner, the handlebar 30, the left front wheel 20L, and the right front wheel 20R are connected via the steering force transmission mechanism 6. As shown in Fig. 5, when the rider steers the handlebar 30, the steering shaft 31 rotates left and right. With the rotation of the steering shaft 31, the left front wheel 20L and the right front wheel 20R rotate left and right, and the traveling direction of the left front wheel 20L and the right front wheel 20R is changed, as shown by the arrows S and T.

[0050] The body frame 10, the left front wheel 20L, and the right front wheel 20R are connected via a link mechanism 40. As shown in Fig. 6, when the rider leans the body frame 10, the left front wheel 20L and the right front wheel 20R also lean.

[0051] As shown in FIG. 7, when the rider steers the handlebars 30 and leans the body frame 10, the left front wheel 20L and the right front wheel 20R lean and the traveling direction is changed.

[0052] As described above, the lean vehicle 1 includes the left in-wheel motor 50L that drives the left front wheel 20L and the right in-wheel motor 50R that drives the right front wheel 20R (see FIG. 2). The lean vehicle 1 can control the left front wheel 20L and the right front wheel 20R independently of each other. As shown in FIG. 8, the lean vehicle 1 includes a control device 70 that controls the left in-wheel motor 50L and the right in-wheel motor 50R. The control device 70 is configured by a microcomputer having a CPU 71 and a memory 72. The control device 70 may be separate from the control device that controls the power unit 4, or may be used as the control device that controls the power unit 4. The control device 70 is connected to be able to communicate with the left in-wheel motor 50L and the right in-wheel motor 50R.

[0053] The lean vehicle 1 includes a bank angle sensor 81 that detects the bank angle (hereinafter simply referred to as bank angle) of the body frame 10, an angular velocity sensor 82 that detects the angular velocity of the bank angle (hereinafter referred to as bank angular velocity), a vehicle speed sensor 83 that detects the traveling speed (hereinafter referred to as vehicle speed) of the lean vehicle 1, and a front sensor 84 that detects an object in front of the lean vehicle 1. The bank angle sensor 81, the angular velocity sensor 82, the vehicle speed sensor 83, and the front sensor 84 are communicatively connected to the control device 70. For example, an inertial measurement unit (IMU) can be suitably used as the bank angle sensor 81. However, the bank angle sensor 81 is not limited in any way. For example, a potentiometer that detects the displacement amount of the link mechanism 40 (for example, the rotation angle of the left side member 43 relative to the upper cross member 41) may be used as the bank angle sensor 81. The angular velocity sensor 82 may be a sensor separate from the bank angle sensor 81, or the control device 70 may detect the bank angular velocity by calculating the amount of change per unit time of the bank angle detected by the bank angle sensor 81. In this case, the angular velocity sensor 82 is composed of the bank angle sensor 81 and the control device 70. The forward sensor 84 can suitably be a camera, a millimeter wave radar, a sensor using LiDAR (Light Detection And Ranging), an infrared sensor, or the like.

[0054] The lean vehicle 1 includes an input device 85 operated by a rider. The location of the input device 85 is not particularly limited. For example, the input device 85 may be located behind the handlebar 30 and in front of the seat 2. As described below, the lean vehicle 1 is capable of various controls by controlling the drive torque of the left front wheel 20L and the right front wheel 20R. The input device 85 is used for the rider to adjust the control amount related to those controls. The specific configuration of the input device 85 is not limited in any way. The input device 85 may include, for example, an input dial, a numeric keypad, an enter key, or a touch panel.

[0055] The above is the configuration of the lean vehicle 1. The lean vehicle 1 according to this embodiment can control the drive torque of the left front wheel 20L and the drive torque of the right front wheel 20R independently of each other, so that various controls are possible. Note that the drive torque (hereinafter simply referred to as torque) is synonymous with the drive force. Next, an example of the control that the lean vehicle 1 can execute will be described.

[0056] (First control) The first control is a control for adjusting the steering characteristic according to the rider's preference. The steering characteristic is a characteristic related to the force with which the rider holds the handlebar 30 (i.e., the holding force) while the lean vehicle 1 is turning. Figure 9 is a flowchart of the first control.

[0057] First, in step S11, it is determined whether the bank angle φ detected by the bank angle sensor 81 is equal to or greater than a predetermined threshold value φmin. When the lean vehicle 1 is traveling straight, the body frame 10 may tilt slightly to the left or right. However, when the lean vehicle 1 is traveling straight, the bank angle φ does not become large. On the other hand, when the lean vehicle 1 turns, the bank angle φ becomes relatively large. The threshold value φmin is set to a predetermined value in advance as the minimum bank angle φ when the lean vehicle 1 is considered to be turning. The threshold value φmin is stored in the memory 72 (see FIG. 8) of the control device 70. In step S11, it is determined whether the lean vehicle 1 is turning. If the determination result in step S11 is YES, the process proceeds to step S12. If the determination result in step S11 is NO, this control is terminated.

[0058] In step S12, the control device 70 calculates target torques for the left front wheel 20L and the right front wheel 20R based on the information related to the steering characteristic input by the rider and the running state of the lean vehicle 1.

[0059] In step S13, the control device 70 controls the left in-wheel motor 50L and the right in-wheel motor 50R so that the torques output by the left front wheel 20L and the right front wheel 20R become the respective target torques, and then returns to step S11.

[0060] The method of calculating the target torque in step S12 is not limited. The target torque is calculated, for example, as follows. In one example of calculating the target torque, the control device 70 calculates the target torque TL of the left front wheel 20L and the target torque TR of the right front wheel 20R based on the input value M of the rider to the input device 85, the vehicle speed V, and the bank angle φ. The target torques TL and TR are calculated by adding or subtracting an adjustment torque ΔT to a reference torque T0. Here, the reference torque T0 refers to the target torque of the left front wheel 20L and the right front wheel 20R that is determined based on the operation amount of the accelerator grip 33R by the rider and the running state of the lean vehicle 1. When the lean vehicle 1 is traveling straight, the target torque TL of the left front wheel 20L and the target torque TR of the right front wheel 20R are equal to each other and each coincides with the reference torque T0. The adjustment torque ΔT is a torque that is added or subtracted to adjust the steering characteristics. Here, the adjustment torque ΔT is calculated by multiplying a predetermined torque Tm by a coefficient K, i.e., ΔT=K×Tm. The coefficient K is calculated by multiplying a base factor FB, a speed factor Fv, and a bank angle factor Fφ, i.e., K=FB×Fv×Fφ.

[0061] FIG. 10(a) is a graph showing the relationship between the input value M and the base factor FB. The method of inputting the input value M to the input device 85 is not limited in any way. For example, if the input device 85 has an input dial and an enter key, the input value M can be changed by rotating the input dial and the input value M can be input by pressing the enter key. If the input device 85 has a numeric keypad and an enter key, the input value M can be changed by pressing the numeric keypad and the input value M can be input by pressing the enter key. If the input device 85 has a touch panel, the input value M can be changed and input by operating the touch panel. The same applies to the input of the input value M in each control described later.

[0062] FIG. 10(b) is a graph showing the relationship between vehicle speed V and speed factor Fv. Here, between V1 and V2, the speed factor Fv is set to increase as the vehicle speed V increases. FIG. 10(c) is a graph showing the relationship between bank angle φ and bank angle factor Fφ. Here, between φ1 and φ2, the bank angle factor Fφ is set to increase as the bank angle φ increases. The information shown in FIGS. 10(a) to 10(c) is stored in memory 72 of control device 70.

[0063] When the lean vehicle 1 turns, one of the left front wheel 20L and the right front wheel 20R becomes an outer wheel, and the other becomes an inner wheel. In detail, when the lean vehicle 1 turns right, the left front wheel 20L becomes an outer wheel, and the right front wheel 20R becomes an inner wheel. When the lean vehicle 1 turns left, the right front wheel 20R becomes an outer wheel, and the left front wheel 20L becomes an inner wheel. In this embodiment, it is possible to execute counter steering control, which makes the torque of the outer wheel larger than that of the inner wheel, and pull steering control, which makes the torque of the outer wheel smaller than that of the inner wheel. The rider can select counter steering control or pull steering control by operating the input device 85. For example, a selection switch may be provided in the input device 85, and the rider may select counter steering control or pull steering control by operating the selection switch.

[0064] In the case where the rider selects counter-steering control, for example, when the lean vehicle 1 turns right, the control device 70 sets the torque obtained by adding the adjustment torque ΔT to the reference torque T0 as the target torque TR of the right front wheel 20R, and sets the torque obtained by subtracting the adjustment torque ΔT from the reference torque T0 as the target torque TL of the left front wheel 20L. That is, TR=T0+ΔT, TL=T0-ΔT. As a result, as shown in, for example, FIG. 11(a) and FIG. 11(b), after the lean vehicle 1 starts turning right (after time t=t1), the torque TR of the right front wheel 20R increases and the torque TL of the left front wheel 20L decreases. As a result, the torque of the inner wheel becomes larger than the torque of the outer wheel, and a counterclockwise force is applied to the handlebar 30. A force in the opposite direction to the turning direction of the lean vehicle 1 acts on the handlebar 30, and the rider's preferred steering characteristics are obtained.

[0065] In the case where the rider selects pull steering control, for example when the lean vehicle 1 turns right, the control device 70 sets the torque obtained by subtracting the adjustment torque ΔT from the reference torque T0 as the target torque TR of the right front wheel 20R, and sets the torque obtained by adding the adjustment torque ΔT to the reference torque T0 as the target torque TL of the left front wheel 20L. In other words, TR=T0-ΔT, TL=T0+ΔT. As a result, the torque of the outer wheel becomes greater than the torque of the inner wheel, so a clockwise force is applied to the handlebar 30. A force in the same direction as the turning direction of the lean vehicle 1 acts on the handlebar 30, and the rider's preferred steering characteristics are obtained.

[0066] (Second control) The second control is a control for preventing the lean vehicle 1 from tipping over during turning. Fig. 12 is a flowchart of the second control.

[0067] First, in step S21, it is determined whether the vehicle speed V is equal to or greater than a predetermined threshold value Vmin. The threshold value Vmin is an example of a "first threshold value." The threshold value Vmin is set in advance as a predetermined value as the minimum vehicle speed V when the lean vehicle 1 is considered to be traveling, and is stored in the memory 72 of the control device 70. If the determination result in step S21 is YES, the process proceeds to step S22. If the determination result in step S21 is NO, this control is terminated.

[0068] In step S22, it is determined whether the bank angle φ is equal to or greater than a predetermined threshold value φt. The bank angle φ can be positive or negative. The "bank angle φ" in step S22 refers to the absolute value of the bank angle φ. The threshold value φt is an example of a "second threshold value." Step S22 is a process for determining whether the inclination of the body frame 10 is large. If the determination result in step S22 is YES, the anti-toppling control in step S24 is executed. If the determination result in step S22 is NO, the process proceeds to step S23.

[0069] In step S23, it is determined whether the bank angular velocity ω=dφ / dt is equal to or greater than a predetermined threshold value ωt. The bank angular velocity ω can be positive or negative. The "bank angular velocity ω" in step S23 means the absolute value of the bank angular velocity ω. The threshold value ωt is an example of a "third threshold value." Step S23 is a process for determining whether the inclination speed of the body frame 10 is large. If the determination result of step S23 is YES, the anti-toppling control of step S24 is executed. If the determination result of step S23 is NO, there is no risk of toppling over, so this control is terminated. The order of steps S22 and S23 may be reversed. In this case, if the determination result of step S23 is YES, the process proceeds to step S24, and if the determination result of step S23 is NO, step S22 is executed.

[0070] The specific processing of step S24 is not limited in any way, but for example, the following processing is performed. Here, the control device 70 calculates the target torque TL of the left front wheel 20L and the target torque TR of the right front wheel 20R based on the input value M by the rider to the input device 85, the vehicle speed V, the bank angle φ, and the bank angular velocity ω. As in the first control example, the control device 70 calculates the target torques TL and TR by adding or subtracting the adjustment torque ΔT to the reference torque T0. The adjustment torque ΔT is calculated by multiplying a predetermined torque Tm by a coefficient K. ΔT=K×Tm. The coefficient K is calculated by multiplying a base factor FB, a speed factor Fv, a bank angular velocity factor Fω, and a bank angle factor Fφ. That is, K=FB×Fv×Fω×Fφ.

[0071] FIG. 13(a) is a graph showing the relationship between the input value M and the base factor FB. FIG. 13(b) is a graph showing the relationship between the vehicle speed V and the speed factor Fv. FIG. 13(c) is a graph showing the relationship between the bank angular velocity ω and the bank angular velocity factor Fω. Note that the bank angular velocity ω can be positive or negative, but the bank angular velocity ω shown in FIG. 13(c) means the absolute value of the bank angular velocity ω. FIG. 13(d) is a graph showing the relationship between the bank angle φ and the bank angle factor Fφ. Here, the bank angle φ is positive to the right and negative to the left. Therefore, when turning right, the bank angle φ takes a positive value, and when turning left, the bank angle φ takes a negative value. The information shown in FIG. 13(a) to FIG. 13(d) is stored in the memory 72 of the control device 70.

[0072] For example, when the lean vehicle 1 turns right, the control device 70 sets the torque obtained by adding the adjustment torque ΔT to the reference torque T0 as the target torque TR of the right front wheel 20R, and sets the torque obtained by subtracting the adjustment torque ΔT from the reference torque T0 as the target torque TL of the left front wheel 20L. That is, TR=T0+ΔT, TL=T0-ΔT. When the lean vehicle 1 turns right, the bank angle φ is a positive value, so the bank angle factor Fφ is positive (see FIG. 13(d)), and K is a positive value. Since ΔT=K×Tm, ΔT is a positive value. Therefore, the target torque TR of the right front wheel 20R is greater than the reference torque T0, and the target torque TL of the left front wheel 20L is smaller than the reference torque T0.

[0073] When the lean vehicle 1 turns right, the left front wheel 20L becomes the outer wheel and the right front wheel 20R becomes the inner wheel. Therefore, by the control device 70 adjusting the target torque TL of the left front wheel 20L and the target torque TR of the right front wheel 20R as described above, the torque of the inner wheel becomes larger and the torque of the outer wheel becomes smaller. Therefore, a counterclockwise force is applied to the handlebar 30. A force in the opposite direction to the turning direction of the lean vehicle 1 acts on the handlebar 30, and a force that tries to raise the body frame 10 acts on the body frame 10. Therefore, it is possible to prevent the lean vehicle 1 from tipping over. Furthermore, according to this embodiment, the larger the bank angular velocity ω, the larger the bank angular velocity factor Fω (see FIG. 13(c)), and the larger the bank angle φ, the larger the bank angle factor Fφ (see FIG. 13(d)). Therefore, it is possible to more reliably prevent the lean vehicle 1 from tipping over.

[0074] The above process for step S24 is merely an example. The control amount factor K may be determined based on only one of the base factor FB, the speed factor Fv, the bank angular velocity factor Fω, and the bank angle factor Fφ, or may be determined based on any two or three of the factors.

[0075] (Third control) The third control is a control for generating a force to raise the body frame 10 when the bank angle of the body frame 10 becomes equal to or greater than a predetermined value while the lean vehicle 1 is turning.

[0076] In the third control, steps S11 to S13 are executed in the same manner as in the first control (see FIG. 9). However, in the third control, the processing content of step S12 is different from that in the first control.

[0077] In the third control, for example, the following process is performed in step S12. The control device 70 calculates the target torque TL of the left front wheel 20L and the target torque TR of the right front wheel 20R based on the input value M by the rider to the input device 85, the vehicle speed V, the bank angular velocity ω, and the bank angle φ. The control device 70 calculates the target torques TL and TR by adding or subtracting the adjustment torque ΔT to the reference torque T0. The adjustment torque ΔT is calculated by multiplying a predetermined torque Tm by a coefficient K. ΔT=K×Tm. The coefficient K is calculated by multiplying a base factor FB, a speed factor Fv, a bank angular velocity factor Fω, and a bank angle factor Fφ. K=FB×Fv×Fω×Fφ.

[0078] FIG. 14(a) is a graph showing the relationship between the input value M and the base factor FB. FIG. 14(b) is a graph showing the relationship between the vehicle speed V and the speed factor Fv. FIG. 14(c) is a graph showing the relationship between the bank angular velocity ω and the bank angular velocity factor Fω. Note that the bank angular velocity ω can be positive or negative, but the bank angular velocity ω shown in FIG. 14(c) means the absolute value of the bank angular velocity ω. FIG. 14(d) is a graph showing the relationship between the bank angle φ and the bank angle factor Fφ. Here, the bank angle φ is positive to the right and negative to the left. Therefore, when turning right, the bank angle takes a positive value, and when turning left, the bank angle takes a negative value. When the bank angle φ is -φa<φ<φa with respect to a predetermined threshold value φa, the bank angle factor Fφ is zero. Therefore, when the absolute value of the bank angle φ is relatively small, that is, when 0<|φ|<φa, K=0, and the torque of the left front wheel 20L and the right front wheel 20R is not adjusted. On the other hand, when the absolute value of the bank angle φ is relatively large, that is, when φa≦|φ|, K takes a positive or negative value, and the torque of the left front wheel 20L and the right front wheel 20R is adjusted. The information shown in Figs. 14(a) to 14(d) is stored in the memory 72 of the control device 70.

[0079] For example, when the lean vehicle 1 turns right, the control device 70 sets the torque obtained by adding the adjustment torque ΔT to the reference torque T0 as the target torque TR of the right front wheel 20R, and sets the torque obtained by subtracting the adjustment torque ΔT from the reference torque T0 as the target torque TL of the left front wheel 20L. That is, TR=T0+ΔT, TL=T0-ΔT. When the lean vehicle 1 turns right, the bank angle φ takes a positive value, so when φa≦φ, the bank angle factor Fφ is positive (see FIG. 14(d)), and K takes a positive value. Since ΔT=K×Tm, ΔT takes a positive value. Therefore, when φa≦φ, the target torque TR of the right front wheel 20R is greater than the reference torque T0, and the target torque TL of the left front wheel 20L is smaller than the reference torque T0.

[0080] When the lean vehicle 1 turns right, the left front wheel 20L becomes the outer wheel and the right front wheel 20R becomes the inner wheel. Therefore, by the control device 70 adjusting the target torque TL of the left front wheel 20L and the target torque TR of the right front wheel 20R as described above, when φa≦φ, the torque of the inner wheel becomes large and the torque of the outer wheel becomes small. Therefore, a counterclockwise force is applied to the handlebar 30. A force in the opposite direction to the turning direction of the lean vehicle 1 acts on the handlebar 30, and a force that tries to raise the body frame 10 acts on the body frame 10. According to this embodiment, when the bank angle φ is relatively small (i.e., when 0<φ<φa), no force that tries to raise the body frame 10 is generated, and when the bank angle φ is relatively large (i.e., when φa≦φ), a force that tries to raise the body frame 10 is generated. Therefore, when the bank angle φ becomes too large, the rider can raise the body frame 10 relatively easily.

[0081] In addition, when the target torque is not adjusted when the bank angle φ is less than a predetermined value, and is adjusted when the bank angle φ is equal to or greater than the predetermined value, as in this control, the following effects can be obtained. That is, when the bank angle φ becomes equal to or greater than a predetermined value, a difference occurs between the torque of the left front wheel 20L and the torque of the right front wheel 20R, and the force acting on the handlebar 30 changes. Therefore, the rider can know that the bank angle φ has become equal to or greater than the predetermined value by feeling the change in the load on the handlebar 30. For example, if the predetermined value is set as the lean limit value, the rider can be notified of the lean limit while the lean vehicle 1 is turning.

[0082] (4th control) The fourth control is a control for notifying the rider when an object is detected in front of the lean vehicle 1. Fig. 15 is a flowchart of the fourth control.

[0083] First, in step S41, it is determined from the detection result of the front sensor 84 whether or not there is an object (hereinafter referred to as an obstacle) such as another vehicle or a wall in front of the lean vehicle 1. In this embodiment, the rider is notified when the lean vehicle 1 is traveling straight and the vehicle speed is relatively high. Then, in step S42, it is determined whether or not the vehicle speed V is equal to or greater than a threshold value Vb and the bank angle φ is equal to or less than a threshold value φb. Note that Vb is an example of the "fourth threshold value" and φb is an example of the "fifth threshold value". If the determination result in step S42 is YES, the process proceeds to step S43, and the rider is notified.

[0084] In step S43, a notification control is executed to alternately repeat a first state in which the torque of the right front wheel 20R is greater than the torque of the left front wheel 20L and a second state in which the torque of the left front wheel 20L is greater than the torque of the right front wheel 20R. Although the specific processing of step S43 is not limited in any way, for example, the following processing is performed.

[0085] The control device 70 calculates a target torque TL for the left front wheel 20L and a target torque TR for the right front wheel 20R based on an input value M input by the rider to the input device 85. The control device 70 calculates the target torques TL and TR by adding or subtracting an adjustment torque ΔT to a reference torque T0. The adjustment torque ΔT is calculated by multiplying a predetermined torque Tm by a coefficient K. Here, the coefficient K is calculated by multiplying a base factor FB, a speed factor Fv, and a bank angle factor Fφ. K=FB×Fv×Fφ.

[0086] FIG. 16(a) is a graph showing the relationship between the input value M and the base factor FB. FIG. 16(b) is a graph showing the relationship between the vehicle speed V and the speed factor Fv. FIG. 16(c) is a graph showing the relationship between the bank angle φ and the bank angle factor Fφ. Note that the bank angle can be a positive or negative value, but the bank angle φ shown in FIG. 16(c) means the absolute value of the bank angle. The information shown in FIGS. 16(a) to (c) is stored in the memory 72 of the control device 70.

[0087] 17(a) and 17(b) are graphs showing the change in the adjustment torque ΔTR for the right front wheel 20R and the adjustment torque ΔTL for the left front wheel 20L, respectively. The control device 70 alternates between a first state C1 in which ΔTR=+K×Tm and ΔTL=-K×Tm, and a second state C2 in which ΔTR=-K×Tm and ΔTL=+K×Tm. In the first state C1, the torque TR of the right front wheel 20R becomes larger than the torque TL of the left front wheel 20L, and a counterclockwise force is applied to the handlebar 30. In the second state C2, the torque TL of the left front wheel 20L becomes larger than the torque TR of the right front wheel 20R, and a clockwise force is applied to the handlebar 30. Therefore, the first state C1 and the second state C2 are alternately repeated, and a counterclockwise load and a clockwise load are alternately applied to the rider holding the handlebar 30. This allows the rider to know that there is an obstacle ahead. That is, a notice is given to the rider. In this embodiment, the first state C1 and the second state C2 are not consecutive, and a state in which the torque of the left front wheel 20L and the right front wheel 20R is not adjusted is present between the first state C1 and the second state C2.

[0088] According to this control, the rider can easily recognize the presence of an obstacle ahead by feeling the load fluctuation on the handlebar 30. Therefore, when there is an obstacle ahead, the rider can start operations such as reducing speed or avoiding the obstacle early.

[0089] In the above description, the front sensor 84 detects whether or not there is an obstacle in front of the lean vehicle 1. However, the detection target of the front sensor 84 is not limited to an obstacle. The detection target of the front sensor 84 may be, for example, a center line provided on the road surface. For example, the front sensor 84 may determine whether or not the lean vehicle 1 is approaching the center line, and when the determination result is YES, the notification control of step S43 may be executed. In this case, the rider can easily grasp that there is a possibility that the lean vehicle 1 will cross the center line. Therefore, the rider can be alerted not to cross the center line. The rider who has received the notification can operate the handlebar 30 to prevent the lean vehicle 1 from crossing the center line. [Explanation of symbols]

[0090] 1... lean vehicle, 10... vehicle body frame, 12... head pipe, 20L... left front wheel, 20R... right front wheel, 30... handlebar, 31... steering shaft, 40... link mechanism, 50L... left in-wheel motor, 50R... right in-wheel motor, 70... control device, 81... bank angle sensor, 82... angular velocity sensor, 83... vehicle speed sensor, 84... forward sensor, 85... input device

Claims

1. a body frame having a head pipe; A left front wheel disposed to the left of the head pipe; A right front wheel disposed to the right of the head pipe; a steering shaft supported by the head pipe and rotatable left and right together with the left front wheel and the right front wheel; A handlebar fixed to the steering shaft and operated by a rider; a link mechanism connecting the body frame to the left front wheel and the right front wheel such that the body frame, the left front wheel, and the right front wheel can tilt with respect to the ground; a left in-wheel motor provided on the left front wheel; a right in-wheel motor provided on the right front wheel; A lean vehicle equipped with.

2. a bank angle sensor for detecting a bank angle of the vehicle body frame; a control device communicatively connected to the bank angle sensor and controlling the left in-wheel motor and the right in-wheel motor based on the bank angle detected by the bank angle sensor; 2. The lean vehicle of claim 1, comprising:

3. 3. The lean vehicle according to claim 2, wherein the control device is configured to be capable of adjusting a difference between the driving force of the left front wheel and the driving force of the right front wheel during turning.

4. An input device operated by a rider, 4. The lean vehicle according to claim 3, wherein the control device is communicatively connected to the input device and is configured to adjust the difference between the driving force of the left front wheel and the driving force of the right front wheel during turning based on an input value to the input device by the rider.

5. When turning, one of the left front wheel and the right front wheel becomes an outer wheel and the other becomes an inner wheel, The lean vehicle according to claim 4 , wherein the control device is configured to be capable of executing counter steering control for making the driving force of the outer wheels greater than the driving force of the inner wheels.

6. When turning, one of the left front wheel and the right front wheel becomes an outer wheel and the other becomes an inner wheel, The lean vehicle according to claim 4 , wherein the control device is configured to be capable of executing steering control to make the driving force of the outer wheels smaller than the driving force of the inner wheels.

7. a bank angle sensor for detecting a bank angle of the vehicle body frame; A vehicle speed sensor for detecting a vehicle speed; a control device that is communicatively connected to the bank angle sensor and the vehicle speed sensor and that controls the left in-wheel motor and the right in-wheel motor based on the bank angle and the vehicle speed; 2. The lean vehicle of claim 1, comprising:

8. When turning, one of the left front wheel and the right front wheel becomes an outer wheel and the other becomes an inner wheel, 8. The lean vehicle according to claim 7, wherein the control device is configured to execute control to reduce the driving force of the outer wheels and / or increase the driving force of the inner wheels when the bank angle is equal to or greater than a threshold value.

9. When turning, one of the left front wheel and the right front wheel becomes an outer wheel and the other becomes an inner wheel, 8. The lean vehicle of claim 7, wherein the control device is configured to execute anti-rollover control to reduce the driving force of the outer wheels and / or increase the driving force of the inner wheels when the vehicle speed is equal to or greater than a first threshold and the bank angle is equal to or greater than a second threshold.

10. an angular velocity sensor for detecting an angular velocity of a bank angle of the vehicle body frame; When turning, one of the left front wheel and the right front wheel becomes an outer wheel and the other becomes an inner wheel, 8. The lean vehicle of claim 7, wherein the control device is configured to execute anti-rollover control to reduce the driving force of the outer wheels and / or increase the driving force of the inner wheels when the vehicle speed is equal to or greater than a first threshold and the angular velocity of the bank angle is equal to or greater than a third threshold.

11. A forward sensor is provided to detect an object in front of the vehicle.

8. The lean vehicle of claim 7, wherein the control device is configured to execute notification control that alternates between a first state in which the driving force of the right front wheel is greater than the driving force of the left front wheel and a second state in which the driving force of the left front wheel is greater than the driving force of the right front wheel when the forward sensor detects the object, the vehicle speed is equal to or greater than a fourth threshold, and the bank angle is equal to or less than a fifth threshold.

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