Saddle-riding type electric vehicle

Abstract

To provide a saddle-riding type electric vehicle that is prevented from unintentionally moving when the vehicle restarts from stopping at an inclined road surface.SOLUTION: A saddle-riding type electric vehicle includes: an electric motor for making a vehicle travel; a control device for controlling power supply to the electric motor; brake operators (brake levers 2cL, 2cR) operated by an occupant to actuate the brake device. When the brake levers 2cL, 2cR are operated to equal to or more than a prescribed threshold (second lever position P2) or when all of the plurality of brake levers 2cL, 2cR are operated, the control device causes the electric motor to be three-phase short-circuited.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a saddle-riding type electric vehicle.

Background Art

[0002] Conventionally, in a scooter-type saddle-riding type electric vehicle whose prime mover is an electric motor, as an anti-accidental start device, a configuration is known in which starting is impossible even if the accelerator is operated unless the brake is operated (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, as one of the controls of an electric motor, there is a control in which when a brake operation is performed, the electric motor is not driven (the power supply to the electric motor is cut off) even if the accelerator is opened. In this configuration, after the saddle-riding type electric vehicle stops by a brake operation, in order to restart, the electric motor cannot be driven unless the brake operation is released. For this reason, when restarting after stopping on a road surface with an upward slope, if the timing of the accelerator operation after releasing the brake is delayed, the saddle-riding type electric vehicle may move backward (slip down) due to the slope of the road surface. Therefore, a means for preventing such an event is required.

[0005] Therefore, an object of the present invention is to prevent unintentional movement of a vehicle when restarting from a stop on a sloped road surface in a saddle-riding type electric vehicle.

Means for Solving the Problems

[0006] As a means for solving the above problems, a first aspect of the present invention is an electric motorcycle (1) including an electric motor (20) for driving the vehicle, a control device (25) for controlling the power supply to the electric motor (20), and a brake operator (2c) operated by a passenger to operate the brake device. When the brake operator is operated to be equal to or greater than a specified threshold value, the control device (25) causes the electric motor (20) to have a three-phase short circuit. According to this configuration, when the brake operator is operated to be equal to or greater than a specified threshold value, by performing three-phase short-circuit control of the electric motor, in addition to the operation of the brake device by the brake operation, a motor brake is generated by the electric motor, and the vehicle can be easily and surely stopped. As a result, even when restarting from a stop on a sloping road surface, the movement of the vehicle due to the slope of the road surface can be prevented, and smooth and rapid starting can be performed. Note that the three-phase short circuit means short-circuiting all of the three phases U, V, and W of a three-phase AC motor (that is, setting the Lo sides of the switches for controlling the U, V, and W phases of the inverter to the ON state) to bring about a three-phase short-circuit state, making it difficult for current to flow through the electric motor and making it difficult for the electric motor to rotate.

[0007] A second aspect of the present invention is an electric motorcycle (1) including an electric motor (20) for driving the vehicle, a control device (25) for controlling the power supply to the electric motor (20), and a plurality of brake operators (2cL, 2cR) operated by a passenger to operate the brake device. When the plurality of brake operators (2cL, 2cR) are both operated, the control device (25) causes the electric motor (20) to have a three-phase short circuit. According to this configuration, when the plurality of brake operators are simultaneously operated, by performing three-phase short-circuit control of the electric motor, in addition to the operation of the brake device by the brake operation, a motor brake is generated by the electric motor, and the vehicle can be easily and surely stopped. As a result, even when restarting from a stop on a sloping road surface, the movement of the vehicle due to the slope of the road surface can be prevented, and smooth and rapid starting can be performed.

[0008] A third aspect of the present invention is that, in the above first or second aspect, an accelerator operator (2aR) is provided which is operated by an occupant to drive the electric motor (20), and the control device (25) short - circuits the three - phase of the electric motor (20) and then releases the three - phase short - circuit when the accelerator operator (2aR) is opened. According to this configuration, by canceling the three - phase short - circuit control of the electric motor according to the accelerator operation, the stop state due to the three - phase short - circuit can be easily canceled by the operation during normal driving, and smooth and prompt start - up can be performed.

Effects of the Invention

[0009] According to the present invention, in a saddle - riding type electric vehicle, when restarting from a stop on a sloped road surface, unintentional movement of the vehicle can be prevented.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the directions such as front, rear, left, and right are the same as those in the vehicle described below unless otherwise specified. In the figures used in the following description, arrows FR indicating the front of the vehicle, LH indicating the left side of the vehicle, UP indicating the upper side of the vehicle, and a line CL indicating the center of the vehicle body left and right are shown at appropriate positions.

[0012] <Entire vehicle> In FIGS. 1 and 2, as an example of a saddle-riding type electric vehicle, a scooter type electric two-wheeler (motorcycle) 1 having a floor portion (low floor portion) 9 on which an occupant (driver) R places their feet is shown. The electric two-wheeler 1 includes a front wheel 3 that is a steering wheel and a rear wheel 4 that is a drive wheel. The front wheel 3 can be steered by a bar handle (steering handle) 2.

[0013] Referring also to FIG. 3, on both the left and right sides of the bar handle 2, a pair of left and right grip portions 2a that are gripped by the occupant R with their left and right hands respectively are provided. The periphery of the bar handle 2 is covered with a handle cover 2b except for the left and right grip portions 2a. In front of the left and right grip portions 2a, a pair of left and right brake levers 2cL, 2cR that are operated by the hands of the occupant R gripping the left and right grip portions 2a and squeezing them are arranged. In the embodiment, the left and right brake levers 2cL, 2cR may be collectively referred to as the brake lever 2c.

[0014] The left and right brake levers 2c are operated to swing rearward (toward the grip portion 2a) about the proximal end side (inside in the vehicle width direction) by being squeezed by the hands gripping the left and right grip portions 2a. By this squeezing operation, brake devices 3a, 4a provided individually on the front and rear wheels 3, 4 are actuated, braking the rotation of the front and rear wheels 3, 4 and thus the forward and backward movement of the electric two-wheeler 1. An accelerator grip (accelerator operating element) 2aR for the occupant R to open and close the accelerator is attached to the right grip portion 2a.

[0015] The rear wheel 4 is driven by an electric motor 20, for example, as an in-wheel motor. The electric motor 20 generates the driving force for the running of the electric two-wheeler 1. The electric two-wheeler 1 includes a floor portion 9 on which a driver seated on the seat 8 places their feet, a front body FB connected to the front of the floor portion 9, and a rear body RB connected to the rear of the floor portion 9. Above the floor portion 9, a straddling space K1 is formed to facilitate the rider R to straddle the vehicle body. For example, inside the rear body RB below the seat 8, a battery 21 for storing the power supplied to the electric motor 20 is housed. For example, inside the floor portion 9, a control device (PCU) 22 for controlling the power of the battery 21 and supplying it to the electric motor 20 is housed.

[0016] Referring also to FIG. 5, battery cables 23 extend from the positive and negative electrodes of the battery 21 respectively. Each battery cable 23 is connected to the PCU 22. A three-phase cable 24 extends from the PCU 22, and this three-phase cable 24 is connected to the electric motor 20 which is a three-phase AC motor. The PCU 22 includes an inverter that converts the DC current supplied by the battery 21 into three-phase AC and supplies it to the electric motor 20. The electric motor 20 performs a power running operation according to the control by the PCU 22 to run the electric two-wheeler 1. The electric motor 20 performs regenerative braking when the electric two-wheeler 1 decelerates, and recovers the kinetic energy of the vehicle body as electrical energy to the battery 21.

[0017] For example, inside the front body FB, an ECU 25 as a vehicle control device that controls the functions of all the electrical components of the electric two-wheeler 1, and an inclination sensor (for example, an acceleration sensor 26 such as an IMU (Inertial Measurement Unit)) that detects the inclination angles of the front, rear, left, and right of the vehicle body, are housed. The acceleration sensor 26 is communicably connected to the ECU 25, and a vehicle speed sensor 27 that detects the vehicle speed of the electric two-wheeler 1, a brake sensor 28 that detects a brake operation on the electric two-wheeler 1, and an accelerator sensor 29 that detects an accelerator operation on the electric two-wheeler 1 are each communicably connected.

[0018] For example, the right brake lever 2cR is for front wheel braking (for front brake operation), and the left brake lever 2cL is for rear wheel braking (for rear brake operation). The functions of the left and right brake levers 2c are not limited to the above, and for example, a configuration in which only one of the left and right brake levers 2c can interlock the front and rear brakes at a specified ratio may be adopted. The front and rear brake devices 3a, 4a can be individually and independently operated according to operations and controls.

[0019] The electric two-wheeler 1 may be configured to include a brake pedal (brake operating element) that is operated by the foot of the passenger R placed on the step. In this case, for example, it is a combination of one of the left and right brake levers 2c (for example, the right brake lever 2cR) and one of the left and right brake pedals (for example, the right brake pedal). The electric two-wheeler 1 is not limited to a scooter-type vehicle having a floor portion 9, and may be a vehicle having a knee grip portion sandwiched between the knees of the passenger R.

[0020] When a brake operation is being performed on the electric two-wheeler 1, it is controlled so that even if an accelerator operation is performed, power is not supplied to the electric motor 20 (that is, it does not run). That is, the electric two-wheeler 1 is controlled so that power is not supplied to the electric motor 20 when a brake operation is performed even during an accelerator operation. Referring to FIG. 2, after the electric two-wheeler 1 stops by a braking operation on a road surface G with a gradient (inclination angle θ) such as an uphill slope, when attempting to restart by releasing (liberating) the braking operation, an accelerator operation will be performed after releasing the braking operation. Therefore, depending on the gradient of the road surface G, there is a risk that the electric two-wheeler 1 will unintentionally move backward (or forward in the case of a downhill slope). To regulate this forward and backward movement, in the embodiment, when stopping under specified conditions, a three-phase short-circuit state of the electric motor 20 is set, and control is performed to prevent the electric two-wheeler 1 from slipping down or the like.

[0021] As conditions for performing the above-described three-phase short-circuit control, the electric two-wheeler 1 stops by a braking operation on a road surface G with a gradient of a predetermined angle or more, and a predetermined braking operation is performed. The inclination angle θ of the road surface G is detected, for example, by an acceleration sensor 26 provided on the electric two-wheeler 1. That is, the acceleration sensor 26 detects the inclination angle of the vehicle body and recognizes this inclination angle as the inclination angle θ of the road surface G. The acceleration sensor 26 is, for example, an IMU, but is not limited thereto, and various sensors that detect the inclination angle of the vehicle body may be used. The fact that the vehicle is in a stopped state is detected, for example, from the detection information of a vehicle speed sensor 27 such as a wheel speed sensor provided on the front and rear wheels 3 and 4.

[0022] The predetermined braking operation for performing the three-phase short-circuit control means that a braking operation is performed on each of the left and right brake levers 2c, and a braking operation with an operation amount (and thus an operating force) of a predetermined value or more is performed on at least one of the brake levers 2c. The braking operation on the left and right brake levers 2c is detected, for example, by the on / off of a pair of left and right brake switches 2dL and 2dR provided on each of the left and right brake levers 2c. In the embodiment, the left and right brake switches 2dL and 2dR may be collectively referred to as the brake switch 2d. Each brake switch 2d functions, for example, as a lighting switch for a brake lamp and switches on / off with a relatively light braking operation force (and thus a light braking force).

[0023] Referring to FIG. 4, the lever position at which the brake switch 2d in the left and right brake levers 2c (the left brake lever 2cL is illustrated in FIG. 4) is turned on (the braking device operates) is indicated by reference numeral P1 in the figure. Reference numeral P0 in the figure indicates the initial position before the left and right brake levers 2c are operated. The brake switch 2d functions as a brake operation sensor that detects that a brake operation has been performed on the brake lever 2c. The left and right brake operation sensors are included in the brake sensor 28.

[0024] The fact that the brake operation has been performed with a predetermined or greater operation amount (and thus operation force) is detected from, for example, the swing angle of the brake lever 2c, the operation amount of an operation force transmission member such as an operation cable, or the load applied to these members. That is, the brake operation amount (and thus the brake operation force) is detected from the operation amount and the load, and when this detected value is equal to or greater than a threshold value, it is determined that a brake operation of a predetermined or greater amount has been performed. For example, in the case of a hydraulic brake, it may be determined that a brake operation of a predetermined or greater amount has been performed from the generated hydraulic pressure of a master cylinder or the like.

[0025] When the detected value of each sensor related to the brake operation amount (or operation force) reaches the threshold value, the brake lever 2c reaches a second lever position P2 where it is gripped more deeply (strongly) than the lever position P1 in the figure. Each sensor related to the brake operation amount (or operation force) functions as a brake operation amount sensor that detects that a brake operation of a predetermined or greater amount has been performed on the brake lever 2c. Each sensor related to the brake operation amount (or operation force) is also included in the brake sensor 28.

[0026] After a predetermined brake operation is performed to carry out three-phase short-circuit control, even if the brake operation is released, the three-phase short-circuit control is maintained until an accelerator operation is performed or until a predetermined time has elapsed. Thereby, when stopping on a road surface G with a gradient (inclination angle θ), the stopped state is maintained even if the brake operation is released, preventing the unintended forward or backward movement of the electric two-wheeler 1. The motor brake due to three-phase short circuit is released, for example, when the occupant R releases the brake lever 2c and opens the accelerator. Thereby, restart from a stop on a gradient road can be easily and surely performed. In the embodiment, when the brake operation amount (or operation force) is equal to or greater than a threshold value, it is determined to perform the three-phase short circuit control, but the present invention is not limited to this configuration. For example, when operations on the left and right brake levers 2c (two brake operations) are performed simultaneously, it may be determined to perform the three-phase short circuit control. At this time, it may be a condition that both of the two brake operations have an operation force equal to or greater than the threshold value, or it may be a condition that only one of the two brake operations has an operation force equal to or greater than the threshold value.

[0027] Hereinafter, the process until the three-phase short circuit control in the ECU 25 is performed and the process until the three-phase short circuit control in the ECU 25 is released will be described with reference to the flowcharts of FIGS. 6 to 8. In the following description, a case where the left and right brake levers 2c are provided as two brake operators is shown. The above process is repeatedly executed at a predetermined cycle when the power is ON (the main switch of the electric two-wheeler 1 is ON). The ECU 25 sends a command to the control unit of the PCU 22 to perform the three-phase short circuit control.

[0028] Referring to FIG. 6, a first example of the process until the three-phase short circuit control is performed will be described. First, in step S11, it is determined whether the electric two-wheeler 1 is in a stopped state. This determination is made, for example, based on whether the vehicle speed is 0 km (or whether a predetermined time has elapsed at a vehicle speed of 0 km). If YES (in a stopped state) in step S11, the process proceeds to step S12. If NO (not in a stopped state) in step S11, the process is terminated once. In step S12, it is determined whether or not the longitudinal inclination (gradient of the road surface G) of the vehicle body in the stopped state is equal to or greater than a specified angle θ1. This determination is made based on, for example, the detection value of an acceleration sensor 26 mounted on the electric two-wheeler 1. For example, it is determined whether or not the absolute value of the angle (forward or backward inclination) detected by the acceleration sensor 26 is equal to or greater than the specified angle θ1. The inclination angle of the vehicle body detected by the acceleration sensor 26 corresponds to the inclination angle θ (uphill or downhill gradient) of the road surface G on which the electric two-wheeler 1 has stopped. If YES in step S12 (the absolute value of the inclination angle θ1 is equal to or greater than the specified angle θ1), the process proceeds to step S13. If NO in step S12 (the absolute value of the inclination angle θ1 is less than the specified angle θ1), the process is terminated once.

[0029] In step S13, it is determined whether or not the operation amount (and thus the operating force) of each brake lever 2c is equal to or greater than a specified value (threshold value, second lever position P2). This determination is made based on the detection value of a brake operation amount sensor. When the motor is stopped by a brake operation, if the gradient of the road surface G is large, there is a risk that the electric two-wheeler 1 will start moving due to this gradient. In particular, when the electric two-wheeler 1 has stopped on an uphill gradient, the electric two-wheeler 1 may move backward unintentionally.

[0030] In the embodiment, in addition to a normal brake operation in which the brake switch 2d is detected as being on, when the brake lever 2c is further squeezed, three-phase short-circuit control of the electric motor 20 is performed to more reliably suppress the forward and backward movement of the electric two-wheeler 1 when stopped. If YES in step S13 (the operation amount of each brake lever 2c is equal to or greater than the specified value), the process proceeds to step S14 and three-phase short-circuit control is performed. If NO in step S13 (the operation amount of each brake lever 2c is less than the specified value), the process is terminated once.

[0031] "YES" in step S13 may be the case where the operation amounts of both of the two brake levers 2cL and 2cR are equal to or greater than a specified value, or may be the case where the operation amount of only one of the two brake levers 2cL and 2cR is equal to or greater than the specified value. That is, it suffices if the operation amount of at least one of the two brake levers 2cL and 2cR is equal to or greater than the specified value.

[0032] Referring to FIG. 7, a second example of the process until the three-phase short-circuit control is performed will be described. The second example is particularly different from the first example in that step S23 is provided instead of step S13. The same components as those in the first example are denoted by the same reference numerals and their description is omitted.

[0033] In step S23, it is determined whether or not the braking operations of both of the brake levers 2c have been performed. This determination is made based on at least one of the on / off state of the brake switch 2d and the detected value of the brake operation amount sensor. In the electric two-wheeler 1 provided with two braking operators, the continuation of the operations of the two braking operators even after stopping is considered to be for surely suppressing the movement of the electric two-wheeler 1 at the time of stopping. For this reason, in the second example, when the operations of the two brake levers 2c are continued even after stopping, the three-phase short-circuit control of the electric motor 20 is performed to more surely suppress the forward and backward movement of the electric two-wheeler 1 at the time of stopping. When YES (the operations of the two brake levers 2c are continued) in step S23, the process proceeds to step S14 to perform the three-phase short-circuit control. When NO (the operation of at least one of the two brake levers 2c is released) in step S23, the process is once terminated. "YES" in step S23 suffices if the brake switches 2d of at least two brake levers 2c are on. "YES" in step S23 may include, for example, the condition that the operation amount of at least one of the two brake levers 2c is equal to or greater than a specified value.

[0034] Referring to FIG. 8, the process until the three-phase short-circuit control is released will be described. First, it is determined whether three-phase short-circuit control is being performed in step S31. If YES (in the three-phase short-circuit control state) in step S31, the process proceeds to step S32. If NO (not in the three-phase short-circuit control state) in step S31, the process is terminated once. In step S32, it is determined whether both of the two brake operators are released. This determination is made, for example, based on whether the brake switch 2d of each brake lever 2c is off. If YES (the brake operation is released) in step S32, the process proceeds to step S33. If NO (the brake operation is not released) in step S32, the process is terminated once. In step S33, it is determined whether the accelerator is opened. This determination is made, for example, based on the detected value of an accelerator opening sensor linked to the accelerator grip 2aR. If YES (the accelerator is opened) in step S33, the process proceeds to step S34. If NO (the accelerator is not opened) in step S33, the process is terminated once.

[0035] In step S34, the three-phase short-circuit control is released, and the electric motor 20 is driven according to the accelerator opening to enable the electric two-wheeler 1 to travel. By such control, even if the gradient of the road surface G at the time of stopping is large, the three-phase short-circuit control is maintained until the occupant R opens the accelerator. Therefore, for example, when restarting from a stop on an uphill gradient, it is possible to suppress the electric two-wheeler 1 from moving backward between releasing the brake operation and opening the accelerator.

[0036] As described above, in the saddle-riding type electric vehicle according to the above embodiment, in the electric two-wheeler 1 including an electric motor 20 that drives the vehicle, a control device (ECU25) that controls the power supply to the electric motor 20, and a brake operator (brake lever 2c) that is operated by the occupant R to operate the brake device, when the brake lever 2c is operated to be equal to or higher than a specified threshold value (second lever position P2), the ECU25 causes the electric motor 20 to have a three-phase short circuit. According to this configuration, when the brake lever 2c is operated beyond a specified threshold value, by performing three-phase short-circuit control of the electric motor 20, in addition to the operation of the braking device by the brake operation, a motor brake by the electric motor 20 is generated, and the vehicle can be easily and surely stopped. Thereby, even when restarting from a stop on a sloped road surface G, movement of the vehicle due to the slope of the road surface G can be prevented, and smooth and prompt starting can be performed.

[0037] Further, in the electric two-wheeler 1, the ECU 25 may be configured to short-circuit the three phases of the electric motor 20 when both of the two brake levers 2cL and 2cR are operated. According to this configuration, when a plurality of brake levers 2cL and 2cR are simultaneously operated, by performing three-phase short-circuit control of the electric motor 20, in addition to the operation of the braking device by the brake operation, a motor brake by the electric motor 20 is generated, and the vehicle can be easily and surely stopped. Thereby, even when restarting from a stop on a sloped road surface G, movement of the vehicle due to the slope of the road surface G can be prevented, and smooth and prompt starting can be performed.

[0038] In the electric two-wheeler 1, an accelerator operating element (accelerator grip 2aR) operated by the occupant R to drive the electric motor 20 is provided, and the ECU 25 releases the three-phase short circuit when the accelerator grip 2aR is opened after short-circuiting the three phases of the electric motor 20. According to this configuration, by releasing the three-phase short-circuit control of the electric motor 20 in response to an accelerator operation, the stop state due to the three-phase short circuit can be easily released by the operation during normal driving, and smooth and prompt starting can be performed.

[0039] Note that the present invention is not limited to the above-described embodiment. For example, the inclination in the front-rear direction of the vehicle body is detected by an inclination sensor, and three-phase short-circuit control is performed on the condition that the inclination of the vehicle body (corresponding to the inclination of the road surface G) is equal to or greater than a predetermined value. However, a configuration may be adopted in which three-phase short-circuit control is performed when a specified braking operation is performed regardless of the inclination of the road surface G. The three-phase short-circuit control may be canceled not only when, for example, an accelerator opening operation is performed, but also, for example, after a predetermined time of about 1 to 2 seconds has elapsed after the braking operation is canceled. The power unit of the present embodiment may be applied to a straddle-type vehicle other than a motorcycle. The straddle-type vehicle includes all vehicles on which a driver rides straddling the vehicle body, and includes not only motorcycles (including motor bicycles and scooter-type vehicles), but also three-wheeled (including vehicles with one front wheel and two rear wheels, and vehicles with two front wheels and one rear wheel) or four-wheeled (such as four-wheel buggies) vehicles. The configuration in the above embodiment is an example of the present invention, and various modifications can be made without departing from the gist of the present invention, such as replacing the components of the embodiment with well-known components.

Description of Reference Numerals

[0040] 1 Motorcycle (straddle-type electric vehicle) 2aR Accelerator grip (accelerator operating element) 2c Brake lever (brake operating element) 2cL, 2cR Left and right brake levers (plural brake operating elements) 20 Electric motor 25 ECU (control device) G Road surface P2 Second lever position (threshold value)

Claims

1. In a saddle-type electric vehicle (1) comprising an electric motor (20) for driving the vehicle, a control device (25) for controlling the power supply to the electric motor (20), and a brake operator (2c) operated by a passenger to operate a brake device, the control device (25) causes a three-phase short circuit of the electric motor (20) when the brake operator is operated beyond a specified threshold value. Saddle-type electric vehicle.

2. In a saddle-type electric vehicle (1) comprising an electric motor (20) for driving the vehicle, a control device (25) for controlling the power supply to the electric motor (20), and a plurality of brake operators (2cL, 2cR) operated by a passenger to operate a brake device, the control device (25) causes a three-phase short circuit of the electric motor (20) when the plurality of brake operators (2cL, 2cR) are both operated. Saddle-type electric vehicle.

3. comprising an accelerator operator (2aR) operated by a passenger to drive the electric motor (20), after causing a three-phase short circuit of the electric motor (20), the control device (25) releases the three-phase short circuit when the accelerator operator (2aR) is opened. The saddle-type electric vehicle according to claim 1 or 2.

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