Saddle-type electric vehicle

Abstract

To provide a saddle-riding type electric vehicle which can obtain large driving force while inhibiting enlargement of a motor.SOLUTION: An two-wheeled electric vehicle includes a master motor 11 and a slave motor 12. The master motor 11 and the slave motor 12 are attached to both ends of a shaft member 13. The two-wheeled electric vehicle includes a transmission mechanism which transmits rotation of the shaft member 13 to a rear wheel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a straddle-type electric vehicle. [Background technology]

[0002] In recent years, straddle-type electric vehicles such as motorcycles that are powered by a motor instead of an internal combustion engine have been developed. One such straddle-type electric vehicle has been disclosed in which the rear drive wheels are driven by an electric motor (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-129338 Summary of the Invention [Problem to be solved by the invention]

[0004] Saddle-type electric vehicles rarely have excessive load weights due to carrying large luggage or carrying many passengers. Therefore, although the drive force obtained by the motor of the saddle-type electric vehicle disclosed in Patent Document 1 is limited, it is fully practical when the load weight is not excessive.

[0005] However, when a saddle-type electric vehicle is loaded with a large amount of luggage or when multiple passengers are permitted to ride, it is difficult to obtain sufficient driving force. While increasing the driving force by increasing the size of the motor is an option, large motors often require high development costs. Furthermore, increasing the size of the motor limits the space available for installing the motor on the vehicle and increases the vehicle's weight.

[0006] In particular, in Southeast Asian countries, saddle-type electric vehicles are often used to carry large amounts of luggage or carry multiple passengers, so there has been a strong demand for saddle-type electric vehicles with increased driving force.

[0007] Therefore, an object of the present invention is to provide a straddle-type electric vehicle that can obtain a large driving force while suppressing an increase in the size of the motor. [Means for solving the problem]

[0008] A saddle-type electric vehicle according to one embodiment of the present invention, which solves the above-described problems, is characterized by including a pair of motors, a shaft member having the pair of motors attached to both ends thereof, and a transmission mechanism that transmits the rotation of the shaft member to a drive wheel.

[0009] With this configuration, the pair of motors supplies driving force to the shaft member. The driving force supplied to the shaft member is transmitted to the drive wheels via a transmission mechanism. In this way, the pair of motors supplies driving force to the drive wheels, so a large driving force can be obtained while suppressing an increase in the size of the motors. In addition, the pair of motors are attached to both ends of the shaft member. This prevents the installation space for the motors from being excessively large.

[0010] In the above-described straddle-type electric vehicle, the pair of motors may be outer rotor brushless motors.

[0011] With this configuration, the wheels can be driven by a motor with a large driving force.

[0012] The saddle-type electric vehicle may further include a rotation angle detection means for detecting a rotation angle of one of the pair of motors, and a controller for controlling the rotation of the pair of motors based on the rotation angle detected by the rotation angle detection means.

[0013] With this configuration, it is possible to use only one controller to drive two motors. When driving two motors, it is often necessary to detect the rotation angle of each motor. In this regard, in the above-mentioned saddle-type electric vehicle, two motors are attached to both ends of a shaft member, so the two motors always rotate in the same phase. Therefore, by detecting the rotation angle of one motor, the rotation angles of both motors can be detected, making it easy to drive two motors with one controller.

[0014] In the above-described straddle-type electric vehicle, the pair of motors may be arranged at positions symmetrical with respect to the center of the vehicle body.

[0015] With this configuration, the stability of the saddle-type vehicle can be improved.

[0016] In the above-described straddle-type electric vehicle, a speed reduction mechanism may be interposed between the shaft member and the drive wheel.

[0017] With this configuration, it is possible to increase or decrease the driving force applied to the wheels without causing large fluctuations in the motor output. [Effects of the Invention]

[0018] According to the straddle-type electric vehicle of the present invention, it is possible to obtain a large driving force while suppressing an increase in the size of the motor. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a side view of an electric motorcycle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partially cutaway side view of the power unit. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 1 is a block diagram of an electric motorcycle. [Figure 6] (A) is a partially cutaway side cross-sectional view of a power generating device with an internal combustion engine attached, (B) is a partially cutaway side cross-sectional view of the power generating device with the internal combustion engine of (A) removed, and (C) is a partially cutaway side cross-sectional view of a power generating device with the internal combustion engine replaced with a motor. DETAILED DESCRIPTION OF THE INVENTION

[0020] An electric motorcycle according to an embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, the front side refers to the forward direction of the vehicle, and the right side and left side refer to the right and left sides when looking at the forward direction of the vehicle.

[0021] Fig. 1 is a side view of an electric motorcycle. As shown in Fig. 1, an electric motorcycle 80, which is an example of a saddle-type electric vehicle of the present invention, is a commercial motorcycle equipped with a motor as a drive source. The electric motorcycle 80 is equipped with a power unit 10. The power unit 10 is located to the left of a front wheel 84 and a rear wheel 91, which are located at the center of the vehicle body, and supplies power to the rear wheel 91. The electric motorcycle 80 is a so-called rear-wheel drive vehicle.

[0022] 1, the electric motorcycle (small vehicle) 80 has a body frame 82 formed by joining together several types of steel materials by welding, etc. The body frame 82 is of a so-called backbone type, with a single main tube 88 extending downward and rearward from a head pipe 83 that supports the front wheel suspension system in a steerable manner, and the area between the head pipe 83 and a rider seat 89 being positioned at a low level to improve ease of straddling the frame.

[0023] A pivot bracket 90 extends below the rear end of the main tube 88, and the front end of a swing arm 92 of a rear wheel suspension system is supported on the pivot bracket 90 so that it can swing up and down. A seat frame 93 extends above and rearward of the rear end of the main tube 88, a seat 89 is disposed on the seat frame 93, and a rear cushion 94 of the rear wheel suspension system is disposed between the seat frame 93 and the swing arm 92. In the drawing, reference numeral 85 denotes a front fork, reference numeral 86 denotes a steering stem, and reference numeral 87 denotes a steering handlebar. A power unit 10, which is the prime mover of the electric motorcycle 80, is supported below the main tube 88.

[0024] Fig. 2 is a partially cutaway side view of the power unit. As shown in Fig. 2, the power unit 10 includes a pair of motors: a master motor 11 and a slave motor 12. Both the master motor 11 and the slave motor 12 are outer rotor brushless motors, and each includes a stator 21, a stator holding member 23, and a rotor 25. The master motor 11 and the slave motor 12 are disposed on opposite sides of a crankcase 50. The rotor 25 of the master motor 11 and the rotor 25 of the slave motor 12 are connected via a shaft member 13. The shaft member 13 is disposed within the crankcase 50. Driving force is supplied to the shaft member 13 by the master motor 11 and the slave motor 12, which are attached to both ends of the shaft member 13, respectively.

[0025] The shaft member 13 is rotatably supported by bearings 30, 30 arranged inside the crankcase 50. The master motor 11 and the slave motor 12 have roughly the same configuration, except for whether or not a rotor position detection sensor (hereinafter referred to as "position sensor") 35 is attached. Below, the configuration of the master motor 11 out of the master motor 11 and the slave motor 12 will be described with reference to Figures 2 to 4. In Figure 2, the same components of the slave motor 12 as those of the master motor 11 are designated by the same reference numerals.

[0026] Fig. 3 is a perspective view of the master motor, and Fig. 4 is an exploded perspective view of the master motor. As shown in Figs. 2 and 3, stator 21 has coils 22. Stator 21 also includes stator core 28. As shown in Fig. 4, stator core 28 has a plurality of teeth 28a protruding in the radial direction, and insulators 29, which are insulating members, are attached to each of these teeth 28a. Coils 22 are wound around teeth 28a of stator core 28 from above insulator 29.

[0027] The stator 21 is fixed to the stator holding member 23 by stator mounting bolts 27 shown in FIG. 2. The stator holding member 23 includes a holding portion 23A formed generally cylindrically from iron or aluminum, and a disk-shaped flange 23B extending from the inner outer peripheral edge of the holding portion 23A. A boss 51 is provided on the crankcase 50, and the flange 23B is fastened to the boss 51 by a mounting bolt 23C. This causes the holding portion 23A to protrude axially outward. The stator 21 is fixed to the holding portion 23A. That is, the stator 21 is fixed to the boss 51 via the stator holding member 23. Furthermore, the boss 51 supports a bearing 30.

[0028] The rotor 25 includes a cylindrical rotor yoke 31 with a bottom. A plurality of magnets 32 are attached to the inner surface of the rotor yoke 31, spaced apart from one another along the circumferential direction. A shaft connection portion 34 that protrudes inward is formed in the center of a side wall portion 33, which is the bottom of the rotor yoke 31. The shaft member 13 is inserted into the shaft connection portion 34 and fixed with bolts B. The magnets 32 of the rotor 25 are assembled facing the outer peripheral surface of the stator 21.

[0029] A position sensor 35, which is an example of a rotation angle detection means, is attached to the flange 23B of the stator holding member 23 via a mounting plate 36. As shown in FIG. 2, the position sensor 35 is disposed along the inner surface of the magnet 32 ​​of the rotor 25, at a distance from the magnet 32. The position sensor 35 detects changes in the magnetic flux of the magnet 32. The detected changes in magnetic flux are output as a signal to a controller 60, which will be described later. The controller 60 determines the rotation position (rotation angle) of the rotor 25 based on the detected changes in magnetic flux (details will be described later). Note that the position sensor 35 and mounting plate 36 are not provided in the slave motor 12.

[0030] 2, a primary drive gear 40a is provided at approximately the center of the longitudinal direction of the shaft member 13 so as to be rotatable integrally with the shaft member 13. The primary drive gear 40a meshes with a primary driven gear 40b that is supported on the right side of the main shaft 5 so as to be rotatable relative to the main shaft 5.

[0031] The transmission 4 is provided behind the shaft member 13 (below in FIG. 2). The transmission 4 includes a main shaft 5 and a counter shaft 6. The main shaft 5 and the counter shaft 6 are arranged with their respective central rotation axes aligned in the left-right direction (parallel to the crank axis).

[0032] A multi-plate clutch 42 is coaxially supported on the right end of the main shaft 5. The multi-plate clutch 42 is a gear-changing clutch and includes a clutch outer 42a, which is cylindrical with a bottom that opens to the right and is supported rotatably relative to the right end of the main shaft 5, and a clutch inner 42b, which is disposed on the inner periphery of the clutch outer 42a and is supported rotatably integrally with the right end of the main shaft 5. A primary driven gear 40b is supported rotatably integrally on the left side of the bottom wall of the clutch outer 42a. The multi-plate clutch 42 temporarily releases the pressure contact of clutch plates (not shown) in conjunction with a gear-shift operation using a shift pedal (not shown), making gear changes in the transmission 4 smoother.

[0033] The transmission 4 includes a main shaft 5, a counter shaft 6, and a set of speed change gears 7 supported across both shafts 5, 6. The rotational power of a shaft member 13 is transmitted from the main shaft 5 to the counter shaft 6 via any gear in the set of speed change gears 7. The left end of the counter shaft 6 forms an engine output section 41.

[0034] The group of speed change gears 7 is made up of gears supported on both shafts 5, 6, the number of which corresponds to the number of speed change stages. The transmission 4 is of a constant mesh type in which corresponding gears of the group of speed change gears 7 are always meshed between both shafts 5, 6. The gears supported on both shafts 5, 6 are classified into free gears that can rotate relatively to the shaft that supports them, fixed gears that can rotate integrally with the shaft that supports them, and slide gears that are spline-fitted to the shaft that supports them. The transmission 4 moves the slide gears by operating a change mechanism (not shown) to select a gear train that corresponds to the speed change stage.

[0035] The rotational power of the shaft member 13 is output to an engine output section 41 on the rear left side via the transmission 4. The engine output section 41 is connected to a rear wheel 91, which is a drive wheel, via a chain-type power transmission mechanism 41a. In this way, the rotational power of the shaft member 13 is transmitted to the rear wheel 91 via the transmission 4 and the chain-type power transmission mechanism 41a. The primary drive gear 40a, the primary driven gear 40b, and the speed change gear group 7 constitute a reduction mechanism.

[0036] Next, the control of the master motor 11 and the slave motor 12 will be described. Figure 5 is a block diagram of an electric motorcycle. As shown in Figure 5, an electric motorcycle 80 is equipped with a controller 60 that controls the master motor 11 and the slave motor 12. The master motor 11 and the slave motor 12 are connected by a shaft member 13, so the rotor of the master motor 11 and the rotor of the slave motor 12 rotate synchronously. In addition, a position sensor 35 is attached to the master motor 11, and the position sensor 35 outputs the detected rotational position of the rotor 25 of the master motor 11 to the controller 60 as a rotational position signal.

[0037] The electric motorcycle 80 also includes a main switch 61 and an accelerator 62. The main switch 61 and the accelerator 62 are electrically connected to the controller 60 via an operation system control unit 63. The operation system control unit 63 controls the running of the electric motorcycle 80 based on an ON / OFF signal sent from the main switch 61, an accelerator signal sent from the accelerator 62, and the like.

[0038] Furthermore, the electric motorcycle 80 includes a main battery 64, a molded case circuit breaker (hereinafter referred to as "MCB") 65, a converter 66, and a load 67. The main battery 64 is, for example, a 96V battery, and supplies power to the master motor 11, the slave motor 12, the load 67, etc. based on control signals from the controller 60 and the operation system control section 63. The MCB 65 opens the electrical circuit when an abnormal overcurrent flows in the master motor 11, the slave motor 12, or the load 67 due to an overload, short circuit, or other cause, and cuts off the power supply from the main battery 64, thereby protecting the load circuit and electrical wires from damage.

[0039] Converter 66 is a DC / DC converter that converts the high voltage supplied from main battery 64 into a low voltage, 12 V in this case, that corresponds to load 67. Load 67 includes lights, a horn, etc., which are respectively turned on and off by being supplied with 12 V electricity.

[0040] The controller 60 converts the DC current supplied from the main battery 64 into a three-phase (U-phase, V-phase, W-phase) AC voltage and supplies it to the coils of the master motor 11 and the slave motor 12. The controller 60 controls the rotation of the master motor 11 and the slave motor 12 based on a rotational position signal sent from a position sensor 35 provided in the master motor 11 and a rotational speed signal sent from an operation system control unit 63. The controller 60 controls the rotation of the master motor 11 and the slave motor 12 by appropriately adjusting the order in which the three-phase (U-phase, V-phase, W-phase) AC voltage is supplied.

[0041] In the electric motorcycle 80 according to this embodiment having the above configuration, driving force is supplied to the shaft member 13 by two motors, the master motor 11 and the slave motor 12. The driving force supplied to the shaft member 13 is transmitted to the rear wheel 91 via a transmission mechanism including the primary drive gear 40a, the primary driven gear 40b, and the transmission gear set 7. In this way, because driving force is supplied to the rear wheel 91 by two motors, the master motor 11 and the slave motor 12, a large driving force can be obtained while suppressing an increase in the size of the motors. Furthermore, the master motor 11 and the slave motor 12 are attached to both ends of the shaft member 13. This prevents the installation space for the master motor 11 and the slave motor 12 from being excessively large.

[0042] Furthermore, both the master motor 11 and the slave motor 12 are configured as outer rotor brushless motors, which means that the moment of inertia of the rotating shaft is greater than that of an inner rotor motor, allowing for stable driving force to be applied to the rear wheels 91.

[0043] Furthermore, the position sensor 35 detects the rotation angle of the rotor 25 of only one of the master motor 11 and slave motor 12. The controller 60 controls the master motor 11 and the slave motor 12 based on the detection results. Normally, when controlling two brushless motors, a controller must control each brushless motor. In contrast, in the electric motorcycle 80 described above, the master motor 11 and the slave motor 12 are connected by a shaft member 13 and rotate in phase. Therefore, the rotation angle of the master motor 11 directly becomes the rotation angle of the slave motor 12, even if the rotation angle of the other motor, the slave motor 12, does not need to be detected. Therefore, by detecting the rotation angle of the master motor 11, the rotation angles of the master motor 11 and the slave motor 12 can be detected, making it easy to drive two motors with one controller. This reduces the number of controllers required.

[0044] In addition, a reduction mechanism consisting of a primary drive gear 40a, a primary driven gear 40b, and a group of transmission gears 7 is interposed between the shaft member 13 and the rear wheel 91. Therefore, it is possible to increase or decrease the driving force applied to the rear wheel 91 without greatly varying the output of the motor.

[0045] Furthermore, in the electric motorcycle 80 described above, the master motor 11 and the slave motor 12 are connected to both ends of the shaft member 13, and the shaft member 13 is rotated by the master motor 11 and the slave motor 12 to apply driving force to the rear wheel 91. Therefore, even when replacing the power engine of a motorcycle equipped with an internal combustion engine as the power engine with a pair of motors and shaft members, the replacement can be easily performed.

[0046] Below, we will explain a motorcycle equipped with an internal combustion engine, and then we will specifically explain the procedure for replacing the power engine of a motorcycle equipped with an internal combustion engine with a pair of motors. (A) is a partially cutaway side cross-sectional view of a power generating unit with an internal combustion engine attached, (B) is a partially cutaway side cross-sectional view of the power generating unit of (A) from which the internal combustion engine has been removed, and (C) is a partially cutaway side cross-sectional view of the power generating unit from which the internal combustion engine has been replaced with motors. As shown in Figure 6(A), a power unit 100 in a motorcycle that uses an internal combustion engine as its power unit is equipped with an internal combustion engine 110 and a crankshaft 120 instead of being equipped with a master motor 11, a slave motor 12, a shaft member 13, etc.

[0047] The internal combustion engine 110 includes a cylinder 111 and a piston 112 inserted into the cylinder 111. A crankshaft 120 is connected to the piston 112. In the internal combustion engine 110 of a motorcycle, fuel is burned in the cylinder 111, and combustion gas generated by the combustion of the fuel pushes out the piston 112. When the piston 112 is pushed out, the crankshaft 120 rotates, causing the piston 112 to reciprocate. In this way, the reciprocating motion of the piston 112 is converted into rotational motion by the crankshaft 120, thereby generating shaft power. A primary drive gear 121 is attached to the crankshaft 120. The primary drive gear 121 is in mesh with the primary driven gear 40b.

[0048] The power unit 100 is also provided with a kick starter 130. The kick starter 130 has a kick spindle 131 arranged in the left-right direction. A base end of a kick arm 132 is attached to the right end of the kick spindle 131. A kick drive gear 133 and a meshing mechanism 134 are coaxially supported on the left side of the kick spindle 131. The kick drive gear 133 rotates integrally with the kick spindle 131 via the meshing mechanism 134 only when the kick spindle 131 rotates in one direction by stepping down on the kick arm 132.

[0049] The kick drive gear 133 meshes with the driven gear of the transmission gear set 7. The kick drive gear 133 is connected to the centrifugal clutch 150 via the transmission gear set 7, the main shaft 5, the multi-plate clutch 42, the primary driven gear 40b, and the primary drive gear 121.

[0050] The power unit 10 according to the present embodiment shown in FIG. 2 can be made into the power unit 10 shown in FIG. 2 by replacing the internal combustion engine 110, crankshaft, kick starter 130, centrifugal clutch 150, etc. of the power unit 100 shown in FIG. 6(A) with a pair of motor and shaft members. In this case, first, the internal combustion engine 110, etc. of the power unit 100 shown in FIG. 6(A) are removed as shown in FIG. 6(B). Specifically, the cylinder 111 and piston 112 of the internal combustion engine 110, and further the crankshaft 120 connected to the piston 112 are removed. At this time, the primary drive gear 121 attached to the crankshaft 120 is disengaged from the primary driven gear 40b. The crankshaft 120 is supported by bearings 30, etc., which are used to support the shaft member 13, and are therefore left in place.

[0051] Next, as shown in FIG. 6(C), the master motor 11, slave motor 12, and shaft member 13 are attached to the positions where the internal combustion engine 110 and crankshaft 120 were removed. More specifically, the shaft member 13 is positioned coaxially with the position where the crankshaft 120 was previously installed, and the master motor 11 and slave motor 12 are positioned at both ends of the shaft member 13. As a result, nothing is installed in the position where the cylinder 111 of the internal combustion engine 110 was previously installed. Furthermore, the primary drive gear 40a installed on the shaft member 13 is meshed with the primary driven gear 40b. In this way, the internal combustion engine is replaced with the motor.

[0052] In this way, when comparing power unit 100 equipped with an internal combustion engine with power unit 10 equipped with a motor, crankshaft 120 can be replaced with shaft member 13, and instead of rotating crankshaft 120 with internal combustion engine 110, shaft member 13 can be rotated with master motor 11 and slave motor 12. Therefore, even when the power engine of a motorcycle equipped with internal combustion engine 110 is replaced with master motor 11 and slave motor 12 to create an electric motorcycle, the power engine can be easily replaced.

[0053] The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiments, a pair of motors is sufficient, and a third motor may be provided in the middle of the pair of motors, or more motors may be provided. Furthermore, although an outer rotor brushless motor is used as the motor, an inner rotor brushless motor or other motors may be used. Furthermore, although a two-wheeled vehicle is used as the saddle-ride type vehicle, a tricycle or other saddle-ride type vehicle may also be used. [Explanation of symbols]

[0054] 7...Speed ​​change gear group (transmission mechanism, reduction mechanism) 10...Power unit 11...Master motor (outer rotor brushless motor) 12...Slave motor (outer rotor brushless motor) 13...Shaft member 21...Stator 22...Coil 23... Stator holding member 23A…Holding part 23B…Tsubabe 23C...Mounting bolt 25...Rotor 26…Case 27... Stator mounting bolt 28...Stator core 28a…Teeth 29...Insulator 30...Bearing 31...Rotor yoke 32...Magnet 33...Side wall 34...Shaft connection part 35... Position sensor (rotation angle detection means) 36...Mounting plate 40a...Primary drive gear (transmission mechanism, reduction mechanism) 40b...Primary driven gear (transmission mechanism, reduction mechanism) 60...Controller 80...Electric two-wheeled vehicle (saddle-type electric vehicle) 91...rear wheel

Claims

1. A pair of motors; a shaft member having the pair of motors attached to both ends thereof; a transmission mechanism that transmits the rotation of the shaft member to a drive wheel; A straddle-type electric vehicle comprising:

2. 2. The straddle-type electric vehicle according to claim 1, wherein the pair of motors are outer rotor brushless motors.

3. a rotation angle detection means for detecting a rotation angle of one of the pair of motors; a controller that controls the rotation of the pair of motors based on the rotation angle detected by the rotation angle detection means; The straddle-type electric vehicle according to claim 1 or 2, comprising:

4. 4. The straddle-type electric vehicle according to claim 1, wherein the pair of motors are disposed at positions symmetrical with respect to the center of the vehicle body.

5. 5. The straddle-type electric vehicle according to claim 1, wherein a speed reduction mechanism is interposed between the shaft member and the drive wheel.

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