drive system

Abstract

Drive system (40) for use in a human-powered vehicle (10), comprising a crank (12) into which human power is input and a drive wheel (14) which is driven by the human power, wherein the drive system (40) comprises: a coupling mechanism (46) which is provided in a power transmission path (T) from the crank (12) to the drive wheel (14); and a motor (44) which is arranged spaced apart from the drive wheel (14) and is connected to the drive wheel (14) via the coupling mechanism (46), wherein the motor (44) is configured to brake the drive wheel (14) in a case in which driving force is received from the drive wheel (14), wherein in a case in which the crank (12) is turned in a first direction (A1), the clutch mechanism (46) is operable in a first state in which the clutch mechanism (46) transmits the human driving force to the drive wheel (14) and turns the drive wheel (14) in a second direction (A2), in a case in which the drive wheel (14) is rotated in the second direction (A2), the clutch mechanism (46) can be operated in a second state in which the clutch mechanism (46) does not transmit any force from the drive wheel (14) to the motor (44), and in a case in which the drive wheel (14) is rotated in the second direction (A2), the clutch mechanism (46) can be operated in a third state in which the clutch mechanism (46) transmits a force from the drive wheel (14) to the motor (44), characterized by the fact that the clutch mechanism (46) is configured to not transmit the human driving force to the drive wheel (14) in the third state, even in a case where the crank (12) is turned in the first direction (A1).

Description

[0001] The present invention relates to a drive system.

[0002] An example of a drive system is disclosed in JP 2016 - 203 735 A. The drive system is configured to, in a case where a human-powered vehicle is moving forward, transfer the rotational force of a crank to a downstream side of a power transmission path and rotate a drive wheel in a forward direction, and transfer the rotational force of the drive wheel in the forward direction to an upstream side of a power transmission path to perform regenerative braking with a motor.

[0003] Further propulsion systems are disclosed in US 8 640 805 B2, EP 1 457 414 B1 and EP 3 287 355 A1.

[0004] In a conventional drive system, the rotational force of the drive wheel is constantly transferred to the upstream side of the drive transmission path during coasting, even when no regenerative braking is required. This increases driving resistance.

[0005] One objective of the present invention is to provide a drive system that limits the increase in driving resistance in a case where a drive wheel rotates in the forward direction.

[0006] A drive system according to a first aspect of the present invention is a drive system for use in a human-powered vehicle, comprising a crank into which human power is applied and a drive wheel driven by the human power. The drive system includes a clutch mechanism and a motor. The clutch mechanism is provided in a power transmission path from the crank to the drive wheel. The motor is spaced apart from the drive wheel and connected to the drive wheel via the clutch mechanism. The motor is configured to brake the drive wheel when power is being received from the drive wheel.In a case where the crank is turned in a first direction, the clutch mechanism can be operated in a first state, in which it transmits the human power to the drive wheel and turns the drive wheel in a second direction. In a case where the drive wheel is turned in the second direction, the clutch mechanism can be operated in a second state, in which it does not transmit any power from the drive wheel to the motor. In a case where the drive wheel is turned in the second direction, the clutch mechanism can be operated in a third state, in which it transmits power from the drive wheel to the motor.According to the propulsion system of the first aspect, the human-driven vehicle is propelled by operating the clutch mechanism in the first state, increases in driving resistance are limited by operating the clutch mechanism in the second state, and the human-driven vehicle is braked by operating the clutch mechanism in the third state.

[0007] According to a second aspect of the present invention, the motor in the drive system according to the first aspect is configured to perform regenerative braking. According to the drive system of the second aspect, the consumption of electrical energy required for braking is reduced.

[0008] According to a third aspect of the present invention, the drive system according to the first or second aspect further comprises a control unit that controls the clutch mechanism. The control unit operates the clutch mechanism in the third state when a predetermined condition is met. According to the drive system of the third aspect, the clutch mechanism is operated in the third state when the predetermined condition is met.

[0009] According to a fourth aspect of the present invention, the drive system according to the first or second aspect further comprises a control unit that operates the clutch mechanism in the third state when an actuating unit provided on the human-powered vehicle is actuated. According to the drive system of the fourth aspect, the clutch mechanism is operated in the third state when the actuating unit is actuated by the user.

[0010] According to a fifth aspect of the present invention, the drive system according to the fourth aspect is configured such that the actuating unit includes a brake lever. According to the drive system of the fifth aspect, the clutch mechanism is operated in the third state when the brake lever is actuated by the user.

[0011] According to the invention, the clutch mechanism in the drive system is configured according to one of the first to fifth aspects in order not to transmit the human driving force to the drive wheel in the third state, even in a case where the crank is turned in the first direction. According to the invention, the human-driven vehicle is not driven by the crank in the third state.

[0012] According to a seventh aspect of the present invention, the motor in the drive system is configured according to one of the first to sixth aspects to assist the propulsion of the human-powered vehicle according to the human driving force in a case where the crank is turned in the first direction. According to the drive system of the seventh aspect, the motor assists the propulsion of the human-powered vehicle.

[0013] According to an eighth aspect of the present invention, the drive system is configured according to one of the first to seventh aspects such that the motor is arranged near the crank.

[0014] According to the drive system of the eighth aspect, a drive unit can be easily constructed that includes the crank and the motor.

[0015] According to a ninth aspect of the present invention, the drive system according to any one of the first to eighth aspects further comprises a base rotatably supporting the crank, with the motor being provided on the base. According to the drive system of the ninth aspect, the crank and the motor are preferably supported by the base.

[0016] According to a tenth aspect of the present invention, the drive system according to any one of the first to ninth aspects is configured such that the clutch mechanism includes a two-way clutch. According to the drive system of the tenth aspect, the first state, the second state, and the third state are easily reached by means of the two-way clutch.

[0017] According to an eleventh aspect of the present invention, the coupling mechanism in the drive system according to the tenth aspect comprises a first element, a second element, a first pawl provided on one of the first and second elements and configured to engage with the other of the first and second elements, and a second pawl provided on one of the first and second elements and configured to engage with the other of the first and second elements. The first pawl configures a first one-way coupling with the first and second elements. The second pawl configures a second one-way coupling with the first and second elements. The second one-way coupling and the first one-way coupling rotate the first and second elements relative to each other in opposite directions.According to the drive system of the eleventh aspect, the first state, the second state and the third state are easily reached by the first one-way coupling and the second one-way coupling.

[0018] According to a twelfth aspect of the present invention, the drive system according to any one of the first to eleventh aspects is configured such that the clutch mechanism is provided at the drive wheel. According to the drive system of the twelfth aspect, the transmission of the rotation of the drive wheel to the upstream side of the power transmission path is restricted in the second state at a point near the drive wheel in the power transmission path.

[0019] According to a thirteenth aspect of the present invention, the drive system according to the twelfth aspect is configured such that the drive wheel has a gear hub and the clutch mechanism is provided in the gear hub. According to the drive system of the thirteenth aspect, the gear hub and the clutch mechanism are integrated.

[0020] According to a fourteenth aspect of the present invention, the drive system according to any of the first to thirteenth aspects is configured such that the clutch mechanism is located near the crank. According to the drive system of the fourteenth aspect, the transmission of the rotation of the drive wheel to the upstream side of the power transmission path is restricted in the second state at a point near the crank in the power transmission path.

[0021] According to a fifteenth aspect of the present invention, the drive system according to any one of the first to thirteenth aspects further comprises a speed converter device provided in a power transmission path from the drive wheel to the motor. The speed converter device is configured to reduce the rotational speed when power is transmitted from the drive wheel to the motor, and the speed converter device is configured to maintain the rotational speed when power is transmitted from the motor to the drive wheel. According to the drive system of the fifteenth aspect, the speed converter device reduces the rotational speed transmitted to the motor in the third state when power is transmitted from the drive wheel to the motor.

[0022] The drive system according to the present invention limits the increase in driving resistance in a case where a drive wheel rotates in the forward direction.

[0023] A more comprehensive assessment of the invention and many of its associated advantages will be readily possible, as it will be better understood through the following detailed description of embodiments of the present invention, which are considered in conjunction with the accompanying drawings. Selected embodiments of the present invention will now be explained with reference to the drawings, wherein Fig. 1 is a side view of a human-powered vehicle that includes a propulsion system according to an embodiment; Fig. 2 is a block diagram showing a power transmission path of the human-powered vehicle according to the embodiment; Fig. Figure 3 is a schematic view showing a coupling mechanism of Fig. 2 shows in a first state; Fig. 4 is a schematic view showing a direction of rotation of a drive mechanism in a case where the coupling mechanism of Fig. 2 is in the first state; Fig. Figure 5 is a schematic view showing the coupling mechanism of Fig. 2 shows in a second state; Fig. Figure 6 is a schematic view showing a direction of rotation of the drive mechanism in a case where the coupling mechanism is located on the outside. Fig. 2 is in a second state; Fig. Figure 7 is a schematic view showing the coupling mechanism of Fig. 2 shows in a third state; Fig. Figure 8 is a schematic view showing a direction of rotation of the drive mechanism in a case where the coupling mechanism is located Fig. 2 is in the third state; Fig. 9 is a block diagram showing the electrical configuration of the human-powered vehicle according to the embodiment; Fig. 10. A flowchart of a process for switching operating states of the clutch mechanism, controlled by a controller of Fig. 9 is executed; Fig. 11 is a block diagram showing a power transmission path of a human-powered vehicle according to a first modified example; Fig. 12 is a block diagram showing a power transmission path of a human-powered vehicle according to a second modified example; and Fig. 13 is a flowchart of a process for switching operating states of the clutch mechanism, which is executed by a controller of a third modified example.

[0024] Identical reference symbols denote corresponding or identical elements in the different drawings.

[0025] A drive system 40 of a human-powered vehicle 10 according to an embodiment is now described with reference to Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 to Fig. The propulsion system 40 is provided in the human-powered vehicle 10. The human-powered vehicle 10 is a vehicle configured to be propelled by human power at a minimum. The number of wheels of the human-powered vehicle 10 is not limited. The human-powered vehicle 10 can, for example, be a unicycle or a vehicle with three or more wheels. The human-powered vehicle 10 is one of several types of bicycles, including a mountain bike, a racing bike, a city bike, a cargo bike, a recumbent bike, and an electrically assisted bicycle (e-bike). In the described and illustrated embodiment, a bicycle is referred to as the human-powered vehicle 10.

[0026] As in Fig. As shown in Figure 1, the human-powered vehicle 10 includes a crank 12 into which a human driving force H is applied, and a drive wheel 14 which is driven by the human driving force H. The human-powered vehicle 10 further includes a frame 16. The crank 12 includes a crankshaft 12A, which is rotatable relative to the frame 16, and crank arms 12B, which are provided at two axial ends of the crankshaft 12A. A pedal 18 is coupled to each crank arm 12B. The drive wheel 14 is driven by the rotation of the crank 12. The drive wheel 14 is supported by the frame 16. The crank 12 and the drive wheel 14 are connected via a drive mechanism 20. The drive mechanism 20 includes a first rotating body 22, which is coupled to the crankshaft 12A. The crankshaft 12A and the first rotating body 22 are coupled via a one-way coupling 20A (see Fig. 2) The one-way coupling 20A is configured to rotate the first rotating body 22 forward when the crank 12 rotates forward, and to prevent the first rotating body 22 from rotating backward when the crank 12 rotates backward. The one-way coupling 20A is configured by a roller coupling, a ratchet-type coupling, or a freewheel coupling. The first rotating body 22 includes a sprocket, a pulley, or a bevel gear. The drive mechanism 20 further includes a connecting element 26 and a second rotating body 24. The connecting element 26 transmits the rotational force from the first rotating body 22 to the second rotating body 24. The connecting element 26 includes, for example, a chain, a belt, or a shaft.

[0027] The second rotating body 24 is connected to the drive wheel 14. The second rotating body 24 includes a sprocket, a pulley, or a bevel gear.

[0028] The human-powered vehicle 10 includes a front wheel and a rear wheel. The front wheel is attached to the frame 16 by a front fork 16A. A handlebar 16C is connected to the front fork 16A via a handlebar stem 16B. In the following description, the rear wheel will be referred to as the drive wheel 14. Alternatively, the front wheel can serve as the drive wheel 14.

[0029] In the present embodiment, the drive wheel 14 includes a gear hub 28. The gear hub 28 is configured to change a gear ratio. The gear ratio is a ratio of the rotational speed of the drive wheel 14 to the rotational speed N of the crank 12. The gear hub 28 can be configured to change the gear ratio in stages using a planetary gear set. Alternatively, the gear hub 28 can be configured using a continuously variable transmission (CVT).

[0030] The human-powered vehicle 10 includes an actuation unit 30. The actuation unit 30 preferably includes a brake lever 30A. The actuation unit 30 is used to actuate the braking device. Preferably, the braking device includes a friction unit that comes into contact with a part of the human-powered vehicle 10 to generate a braking force. The braking device includes at least one disc brake, one rim brake, one drum brake, and one roller brake. The disc brake brakes the wheel by bringing the friction unit into contact with a disc brake rotor provided on the wheel. The disc brake rotor is integrally rotatable with the wheel. The rim brake brakes the wheel by having the friction unit contact the rim of the wheel. The friction unit includes a brake pad or a brake shoe. The brake lever can be configured to pull a cable that actuates the braking device.Alternatively, the brake lever can be configured to control the hydraulic pressure of the hydraulic cable that actuates the brake device. The actuation unit 30 is connected to the control unit 42 of the drive system 40 to communicate with the control unit 42 via a wired or wireless connection. The actuation unit 30 is configured to communicate with the control unit 42, for example, via power line communication (PLC). The actuation unit 30 includes, for example, an actuating element, a detector 30B (see ). Fig. 9), which detects the movement of the actuating element, and an electrical circuit that communicates with the controller 42 according to an output signal from the detector 30B. Preferably, in a case where the actuating unit 30 includes the brake lever 30A, the actuating element includes the brake lever 30A. In a case where the actuating element is actuated by a user, the actuating unit 30 sends an output signal to the controller 42. In a case where the brake lever 30A is actuated, braking is performed by the braking device and the output signal is transmitted to the controller 42. In a case where the actuating unit 30 does not include the brake lever 30A, the actuating element and the detector 30B, which detects the movement of the actuating element, can be configured to include a push button, a toggle switch, or a touch panel.

[0031] The human-powered vehicle 10 is equipped with the battery 32. The battery 32 comprises one or more battery cells. The battery cell contains a rechargeable battery. The battery 32 is provided on the human-powered vehicle 10 to supply electrical energy to other electrical components, such as a motor 44 and the controller 42, which are electrically connected to the battery 32 via wires. The battery 32 is connected to the controller 42 to communicate with it via a wired or wireless connection. The battery 32 is configured to communicate with the controller 42, for example, via power line communication (PLC). The battery 32 is attached to the outside of the frame 16 or at least partially integrated into the frame 16.

[0032] The drive system 40 is used in the human-powered vehicle 10. The drive system 40 includes a clutch mechanism 46, which is located in Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. Figure 8 shows the motor 44. The clutch mechanism 46 is provided in a power transmission path T from the crank 12 to the drive wheel 14. The motor 44 is spaced apart from the drive wheel 14 and connected to it via the clutch mechanism 46 to brake the drive wheel 14 when a driving force is applied. When the crank 12 is turned in a first direction A1, the clutch mechanism 46 can be operated in a first state in which it transmits the human driving force H to the drive wheel 14, turning it in a second direction A2. When the drive wheel 14 is turned in the second direction A2, the clutch mechanism 46 can be operated in a second state in which it does not transmit any force from the drive wheel 14 to the motor 44.Furthermore, in a case where the drive wheel 14 is rotated in the second direction A2, the clutch mechanism 46 can be operated in a third state in which the clutch mechanism transmits the force from the drive wheel 14 to the motor 44. In the third state, the clutch mechanism 46 is configured not to transmit the human driving force H to the drive wheel 14, even in a case where the crank 12 is rotated in the first direction A1. The first direction A1 of the crank 12 corresponds to the direction of rotation of the crank 12 in a case where the human-powered vehicle 10 is moving forward. The second direction A2 of the drive wheel 14 corresponds to the direction of rotation of the drive wheel 14 in a case where the human-powered vehicle 10 is moving forward.In the following description, the direction of rotation of each rotating body contained in the power transmission path T for moving the human-powered vehicle 10 forward is also referred to as the forward direction of rotation, and the direction of rotation opposite to the forward direction of rotation is also referred to as the reverse direction of rotation.

[0033] In the present embodiment, as in Fig. As shown in Figure 1, the motor 44 is located near the crank 12. Preferably, the drive system 40 includes a base 48 for rotatably mounting the crank 12. Preferably, the motor 44 is mounted on the base 48. The base 48 supports the crankshaft 12A. Preferably, the base 48 includes a housing in which at least part of the motor 44 is received. The drive system 40 further includes a drive circuit 44B (see Figure 1). Fig. 9) The motor 44, together with the drive circuit 44B, forms a drive unit 44A. Preferably, the motor 44 and the drive circuit 44B are provided at the base 48. The drive circuit 44B controls the electrical energy supplied by the battery 32 to the motor 44. The drive circuit 44B is connected to the controller 42 of the drive system 40 to communicate with the controller 42 via a wired or wireless connection. The drive circuit 44B is configured to communicate with the controller 42, for example, via serial communication. The drive circuit 44B drives the motor 44 according to a control signal from the controller 42. Preferably, the motor 44 is designed to assist the propulsion of the human-powered vehicle 10.The motor 44 is configured to assist the propulsion of the human-powered vehicle 10 according to the human driving force H when the crank 12 is turned in the first direction A1. Preferably, the motor 44 is configured to perform regenerative braking. The motor 44 can be configured to perform DC braking. The motor 44 includes an electric motor. The motor 44 is positioned along a power transmission path T of the human driving force H from the pedal 18 to the rear wheel to transmit the rotational force. In the present embodiment, the motor 44 is connected to the power transmission path T (see ). Fig. 2) coupled from the crankshaft 12A to the first rotating body 22. The base 48, on which the motor 44 and the drive circuit 44B are provided, can be equipped with components other than the motor 44 and the drive circuit 44B. For example, a reduction gear that reduces the speed generated by the motor 44 and outputs the speed can be provided on the base 48.

[0034] The in Fig. The force transmission path T shown in Figure 2 includes a first force transmission path T1 for the first state and a second force transmission path T2 for the second state.

[0035] The first power transmission path T1 is in Fig. Figure 2 is represented by solid lines. In the first power transmission path T1, the rotational force of the crank 12 is transmitted in the first direction A1 to the drive wheel 14 via a first one-way clutch 46A of the clutch mechanism 46. In a case where the rotational force of the crank 12 is transmitted to the drive wheel 14 in the first direction A1 and the motor 44 assists the propulsion of the human-powered vehicle 10, the power of the motor 44 merges with the human propulsion force H at an output unit 20B, which is contained in the drive mechanism 20. For example, the output unit 20B is arranged such that the axis of rotation of the output unit 20B coincides with the axis of rotation of the crankshaft 12A and surrounds a portion of the crankshaft 12A around the axis of rotation of the crankshaft 12A. Preferably, the one-way clutch 20A is provided between the crankshaft 12A and the output unit 20B in the power transmission path T.

[0036] The second power transmission path T2 is in Fig. 2, indicated by dashed lines. In the second power transmission path T2, the rotational force of the drive wheel 14 is transmitted in the second direction A2 via a second one-way clutch 46B of the clutch mechanism 46 to the motor 44. The motor 44 is rotated in the forward direction by the force transmitted from the drive wheel 14 to the motor 44, and regenerative braking is performed.

[0037] Preferably, the coupling mechanism 46 includes a two-way coupling. Preferably, the coupling mechanism 46 includes a first element 50, a second element 52, first pawls 54, and second pawls 56, as shown in [reference]. Fig. Figure 3 shows the first locking pawls 54 being provided and configured on one of the first element 50 and the second element 52 to be engaged with the other of the first element 50 and the second element 52.

[0038] The second pawls 56 are provided and configured on one of the first elements 50 and the second element 52 to engage with the other of the first element 50 and the second element 52. The first pawls 54 configure the first one-way coupling 46A with the first element 50 and the second element 52. The second pawls 56 configure the second one-way coupling 46B with the first element 50 and the second element 52. The second one-way coupling 46B and the first one-way coupling 46A rotate the first element 50 and the second element 52 in opposite directions relative to each other. In the coupling mechanism 46, the first one-way coupling 46A can be formed separately from the second one-way coupling 46B. In this case, the first one-way coupling 46A and the second one-way coupling 46B can be provided at different points along the power transmission path T.The coupling mechanism 46 can be a freewheel coupling with clamping pieces, a roller coupling, or a disc coupling. The coupling mechanism 46 can include an electromagnetic coupling instead of a two-way coupling.

[0039] In the present embodiment, as in Fig. As shown in Figure 2, the coupling mechanism 46 is provided on the drive wheel 14. In the present embodiment, the coupling mechanism 46 is provided on the gear hub 28. The drive system 40 can be configured to include the gear hub 28. The gear hub 28 is provided in the power transmission path T between a hub housing 14A of the drive wheel 14 and the second rotating body 24. The gear hub 28 is preferably accommodated in the hub housing 14A. The coupling mechanism 46 is provided in the power transmission path T between the hub housing 14A and the second rotating body 24. The coupling mechanism 46 is preferably accommodated in the hub housing 14A.

[0040] In the present embodiment, the in Fig. Figure 3 shows the first element 50 arranged on the second rotating body 24 such that it is integrally rotatable with the second rotating body 24. In the present embodiment, the second element 52 is provided on an input unit of the gear hub 28 such that it is integrally rotatable with the input unit of the gear hub 28. In this case, an output unit of the gear hub 28 includes the hub housing 14A. The first element 50 can be provided on the output unit of the gear hub 28 such that it is integrally rotatable with the output unit of the gear hub 28, and the second element 52 can be provided on the hub housing 14A such that it is integrally rotatable with the hub housing 14A. In this case, the output unit of the gear hub 28 includes a rotating body that is rotatable relative to the hub housing 14A of the gear hub 28.The first element 50 can be provided in the gear hub 28 such that it is integrally rotatable with the rotating body within the gear hub 28, and the second element 52 can be provided in the gear hub 28 such that it is integrally rotatable with a rotating body on a downstream side of the rotating body, which is provided with the first element 50 of the rotating body within the gear hub 28.

[0041] The first element 50 and the second element 52 are rotatable about the axis of rotation C1. One of the first element 50 and the second element 52 is located on the inside of the other of the first element 50 and the second element 52 in a direction perpendicular to the axis of rotation C1. In the present embodiment, the second element 52 is substantially cylindrical, and the first element 50 is surrounded by the second element 52 in a direction perpendicular to the axis of rotation C1. The first pawls 54 and the second pawls 56 are arranged between the first element 50 and the second element 52. A plurality of first pawls 54 can be arranged between the first element 50 and the second element 52. A plurality of second pawls 56 can be arranged between the first element 50 and the second element 52. Grooves 58 are formed in one of the first element 50 and the second element 52.In the present embodiment, the groove 58 is formed in an inner circumferential section of the second element 52. The first pawls 54 and the second pawls 56 are configured to engage with the grooves 58. The first pawls 54 and the second pawls 56 each move between a first position, engaged with the corresponding groove 58 to transmit the rotational force between the first element 50 and the second element 52, and a second position, disengaged from the corresponding groove 58 to allow relative rotation of the first element 50 and the second element. Preferably, the coupling mechanism 46 further includes a first preloading element that preloads each first pawl 54 in a direction projecting towards one of the first element 50 and the second element 52.Preferably, the coupling mechanism 46 further includes a second preloading element that preloads each second pawl 56 in a direction that projects towards one of the first element 50 and the second element 52. The first preloading element and the second preloading element each include a spring.

[0042] The first pawls 54 and the second pawls 56 are each configured to switch between a state that is movable between the first and second positions and a state that is held in the second position. In a case where the first pawls 54 are movable between the first and second positions and the first element 50 is rotated forward at a speed greater than or equal to the speed of the second element 52, the first pawls 54 are each in the first position. In a case where the first pawls 54 are movable between the first and second positions and the second element 52 is rotated forward at a speed greater than or equal to the speed of the first element 50, the first pawls 54 are not engaged with the grooves 58.In a case where the first pawls 54 are each in the first position and the first element 50 is rotated at a speed greater than or equal to the speed of the second element 52 in the forward direction of rotation, the first pawls 54 transmit the rotational force of the first element 50 in the forward direction of rotation to the second element 52. In a case where the second pawls 56 are each movable between the first position and the second position and the second element 52 is rotated at a speed greater than or equal to the speed of the first element 50 in the forward direction of rotation, the second pawls 56 are each in the first position.In a case where the second pawls 56 are each movable between the first and second positions, and the first element 50 is rotated at a speed greater than or equal to the forward rotational speed of the second element 52, the second pawl 56 is not engaged with the grooves 58. In a case where the second pawls 56 are each in the first position, and the second element 52 is rotated at a speed greater than or equal to the forward rotational speed of the first element 50, the second pawls 56 transmit the forward rotational force of the second element 52 to the first element 50.

[0043] The controller 42 operates the clutch mechanism 46 in the first state, the second state, and the third state by holding at least one of the first pawls 54 and the second pawls 56 in the second position. In the present embodiment, the controller 42 operates the clutch mechanism 46 in the first state by allowing each first pawl 54 to move between the first position and the second position while holding each second pawl 56 in the second position. The controller 42 operates the clutch mechanism 46 in the second state by holding each first pawl 54 in the second position and each second pawl 56 in the second position. The controller 42 operates the clutch mechanism 46 in the third state by holding each first pawl 54 in the second position and simultaneously allowing each second pawl 56 to move between the first position and the second position.

[0044] Fig. 3 and Fig. Figure 4 shows the clutch mechanism 46 in its first state. In the first state, the rotational force of the crank 12 is transmitted in the first direction A1 to the drive wheel 14 via the first one-way clutch 46A, and the rotational force is not transmitted between the crank 12 and the drive wheel 14 via the second one-way clutch 46B. In the first state, when the crank 12 is rotated in the first direction A1, the first pawls 54 are in the first position and engaged with the grooves 58. In the first state, when the crank 12 rotates in the first direction A1, the second pawls 56 are in the second position and not engaged with the groove 58.Therefore, in a case where the crank 12 is turned in the first direction A1, the human driving force H is transferred to the drive wheel 14 and the drive wheel 14 is turned in the second direction A2.

[0045] Fig. 5 and Fig. Figure 6 shows the clutch mechanism 46 in the second state. In the case where the clutch mechanism 46 operates in the second state, the rotational force is not transmitted between the crank 12 and the drive wheel 14 through the first one-way clutch 46A, and the rotational force is not transmitted between the crank 12 and the drive wheel 14 through the second one-way clutch 46B. In the case where the drive wheel 14 is rotated in the second direction A2 in the second state, the first pawls 54 are each in the second position and are not engaged with the groove 58. In the case where the drive wheel 14 is rotated in the second direction A2 in the second state, the second pawls 56 are each in the second position and are not engaged with the grooves 58. Therefore, in the case where the drive wheel 14 is rotated in the second direction A2, no force is transmitted from the drive wheel 14 to the motor 44.In a case where the clutch mechanism 46 operates in the second state, the first pawls 54 and the second pawls 56 are arranged such that they do not touch either the first or the second element. This reduces the noise of the clutch mechanism 46.

[0046] Fig. 7 and Fig. Figure 8 shows the clutch mechanism 46 in the third state. In the third state, the rotational force is not transmitted between the crank 12 and the drive wheel 14 through the first one-way clutch 46A, and the rotational force of the drive wheel 14 in the second direction A2 is transmitted to the first rotating body 22 through the second one-way clutch 46B. In the third state, when the drive wheel 14 rotates in the second direction A2, the first pawls 54 are each in the second position and are not engaged with the grooves 58. In the second state, when the drive wheel 14 rotates in the second direction A2, the second pawls 56 are each in the first position and are engaged with the grooves 58. Therefore, in a case where the drive wheel 14 is turned in the second direction A2, the force is transferred from the drive wheel 14 to the motor 44.

[0047] The drive system 40 also includes the control unit 42 for controlling the clutch mechanism 46. The in Fig. The control unit 42 shown in Figure 9 includes a processor that executes a predefined control program. The processor is, for example, a central processing unit (CPU) or a microprocessor unit (MPU). The control unit 42 can include one or more microcomputers. The control unit 42 can include multiple processors at different locations. The drive system 40 also includes a memory 60. The memory 60 stores various control programs and information used for different control processes. The memory 60 includes, for example, non-volatile memory and volatile memory. The control unit 42 and the memory 60 are, for example, provided in the base 48, in which the motor 44 is provided. The control unit 42 can include the drive circuit 44B.

[0048] The control unit 42 operates the clutch mechanism 46 in the third state when a predetermined condition is met. In the present embodiment, the control unit 42 operates the clutch mechanism 46 in the third state when the actuating unit 30 provided on the human-powered vehicle 10 is actuated. The predetermined condition includes the actuating of the actuating unit 30. The control unit 42 switches the operating state of the clutch mechanism 46 to the first state, the second state, or the third state according to the output of the detector 30B.

[0049] The drive system 40 further includes an actuator 62. The actuator 62 actuates the first pawl 54 and the second pawl 56. The actuator 62 includes, for example, an electric motor and a magnet. The control unit 42 switches between a state in which the first pawls 54 and the second pawls 56 are each movable between the first and second positions, and a state in which the first and second pawls 54 and 56 are each held in the second position. The actuator 62 can be configured to switch to the first, second, or third state by controlling the actuator 62. The actuator 62 can be configured to rotate pivot shafts of the first pawls 54 and the second pawls 56 and to move the first pawls 54 and the second pawls 56.The actuator 62 can be configured to move the first pawls 54 and the second pawls 56 by actuating arm elements that push the projections provided on side surfaces of the first pawls 54 and the second pawls 56 in the direction of the axis of rotation of the first pawls 54 and the second pawls 56.

[0050] Preferably, the drive system 40 further includes a crank rotation sensor 64, a vehicle speed sensor 66 and a torque sensor 68.

[0051] The crank rotation sensor 64 is used to detect the rotational speed N of the crank 12. The crank rotation sensor 64 is attached to the frame 16 of the human-powered vehicle 10 or to the base 48 on which the motor 44 is mounted. The crank rotation sensor 64 includes a magnetic sensor that outputs a signal corresponding to the intensity of the magnetic field. A ring magnet, whose magnetic field strength changes circumferentially, is located on the crankshaft 12A or on the power transmission path between the crankshaft 12A and the first rotating body 22. The crank rotation sensor 64 is connected to the controller 42 to communicate with it via a wired or wireless connection. The crank rotation sensor 64 outputs a signal corresponding to the rotational speed N of the crank 12 to the controller 42 of the drive system 40.

[0052] A magnet detected by the crank rotation sensor 64 can be provided on an element that rotates integrally with the crankshaft 12A in the power transmission path of the human driving force H from the crankshaft 12A to the first rotating body 22.

[0053] The vehicle speed sensor 66 is used to detect the rotational speed of the wheel. The vehicle speed sensor 66 is electrically connected to the controller 42, either wired or wirelessly. The vehicle speed sensor 66 communicates with the controller 42 via a wired or wireless connection. The vehicle speed sensor 66 outputs a signal to the controller 42 corresponding to the rotational speed of the wheel. The controller 42 calculates the vehicle speed V of the human-powered vehicle 10 based on the rotational speed of the wheel. Preferably, the vehicle speed sensor 66 includes a magnetic reed switch or a Hall effect sensor. The vehicle speed sensor 66 can be mounted on a chainstay of the frame 16 to detect a magnet attached to the rear wheel, or on the front fork 16A to detect a magnet attached to the front wheel.

[0054] The torque sensor 68 is, for example, located at the base 48 where the motor 44 is mounted. The torque sensor 68 is used to detect a torque TH of the human driving force H at the crank 12. The torque sensor 68 is, for example, located on the upstream side of the one-way coupling 20A in the power transmission path T. The torque sensor 68 includes a strain sensor, a magnetostrictive sensor, or the like. The strain sensor includes a strain gauge. In a case where the torque sensor 68 includes a strain sensor, the strain sensor is, for example, located on the outer circumferential section of the rotating body contained in the power transmission path T. The torque sensor 68 is connected to the controller 42 to communicate with the controller 42 via a wired or wireless connection.The torque sensor 68 can include a wireless or wired communicator. In this case, the communicator of the torque sensor 68 is configured to communicate with the controller 42.

[0055] The control unit 42 is configured to control the motor 44 according to the human driving force H applied to the vehicle 10. The control unit 42 is configured to control the motor 44 such that the ratio X of an auxiliary force M generated by the motor 44 to the human driving force H applied to the crank 12 equals a predetermined ratio. The predetermined ratio can be a constant value, a value that varies according to the human driving force H, a value that varies according to the vehicle speed V, or a value that varies according to the rotational speed N of the crank 12. The human driving force H includes the torque TH of the human driving force H or the power (watts) of the human driving force H.The ratio XT of the torque TM of the auxiliary force M generated by the motor 44 to the torque TH of the human propulsion force H applied to the human-propelled vehicle 10 is also referred to as the ratio X. The ratio XW of the power (watts) of the auxiliary force M generated by the motor 44 to the power (watts) of the human propulsion force H applied to the human-propelled vehicle 10 is also referred to as the ratio X. The work of the human propulsion force H is calculated by multiplying the torque TH of the human propulsion force H applied to the crank 12 by the rotational speed N of the crank 12. In a case where the power of the motor 44 is applied to the power transmission path of the human propulsion force H via the reduction gear, the output of the reduction gear is used as the auxiliary force M by the motor 44.In a case where the speed of the human-powered vehicle 10 is higher than or equal to a predetermined speed, the control unit 42 stops the assistance of the motor 44. The predetermined speed is, for example, 25 km / h or 45 km / h.

[0056] A method for controlling the coupling mechanism 46 is now described with reference to Fig. 10 described. The controller 42 starts the process and proceeds with step S11 of the in Fig. The flowchart shown in Figure 10 continues in a case where electrical energy is supplied from the battery 32 to the controller 42. The drive system 40 includes a power switch. The power switch is located, for example, on the handlebar 16C. In a case where the user activates the power switch in a state where no electrical energy is supplied from the battery 32 to the controller 42, electrical energy is supplied from the battery 32 to the controller 42. In a case where no electrical energy is supplied from the battery 32 to the controller 42, the clutch mechanism 46 is in the first state, which is an initial state.

[0057] In step S11, the controller 42 determines whether the actuating unit 30 has been actuated or not. For example, if the controller 42 receives a signal from detector 30B indicating that the brake lever 30A has been actuated to activate the brake device, the controller 42 determines that the actuating unit 30 has been actuated. If the actuating unit 30 has been actuated, the controller 42 proceeds to step S12.

[0058] In step S12, the control unit 42 operates the clutch mechanism 46 in the third state. Specifically, the control unit 42 controls the actuator 62 to hold each first pawl 54 in the second position and to move each second pawl 56 into a state that is movable between the first and second positions. Thus, the rotation of the drive wheel 14 in the second direction A2 is transmitted to the motor 44.

[0059] After step S12 is executed, the controller 42 proceeds to step S13. In step S13, the controller 42 determines whether or not a shutdown command has been received. If the user operates the power switch while electrical energy is being supplied to the controller 42 from the battery 32, the controller 42 receives a shutdown command. If the controller 42 determines that a shutdown command has been received, it proceeds to step S14, operates the clutch mechanism 46 in the first state, and terminates the process. Specifically, the controller 42 controls the actuator 62 to move each first pawl 54 into a state movable between the first and second positions and to hold each second pawl 56 in the second position. This transmits the rotation of the crank 12 in the first direction A1 to the drive wheel 14.In a case where the controller 42 determines that no shutdown command has been received, the controller 42 terminates the process.

[0060] If the controller 42 determines that the actuating unit 30 was not actuated in step S11, the controller 42 proceeds to step S15. In step S15, the controller 42 determines whether the product of the crank rotation speed N of the crank 12 detected by the crank rotation sensor 64 and the gear ratio is less than the wheel rotation speed detected by the vehicle speed sensor 66. If the controller 42 determines that the product of the crank rotation speed N of the crank 12 and the gear ratio is less than the wheel rotation speed, the controller 42 proceeds to step S16. In step S16, the controller 42 operates the clutch mechanism 46 in the second state and then proceeds to step S13. Specifically, the controller 42 controls the actuator 62 to hold each first pawl 54 in the second position and each second pawl 56 in the second position.Thus, the rotation of the drive wheel 14 in the second direction A2 is not transmitted to the motor 44.

[0061] In a case where the controller 42 determines that the product of the rotational speed N of the crank 12 and the gear ratio is not less than the rotational speed of the wheel in step S15, the controller 42 proceeds to step S17. In step S17, the controller 42 operates the clutch mechanism 46 in the first state and then proceeds to step S13.

[0062] The description relating to the embodiments mentioned above illustrates, without limitation, one applicable form of a drive system according to the present invention. In addition to the embodiments described above, the drive system according to the present invention applies, for example, to modified examples of the embodiments described above and combinations of at least two of the modified examples that do not contradict each other. In the modified examples described below, the components that are identical to the corresponding components of the embodiment described above are given the same reference numerals. A detailed description of these components is omitted.

[0063] The coupling mechanism 46 can be provided near the crank 12. The one in Fig. The coupling mechanism 46 shown in Figure 11 is provided in the drive unit 44A. In this case, for example, the coupling mechanism 46 can be provided in the power transmission path T between the output unit 20B and the motor 44 or in the power transmission path T between the first rotating body 22 and the output unit 20B.

[0064] The drive system 40 can further include a speed converter device 70, which is located in Fig. Figure 12 shows the speed converter device 70, which is located in the power transmission path T from the drive wheel 14 to the motor 44. The speed converter device 70 is configured to reduce the rotational speed when power is transmitted from the drive wheel 14 to the motor 44, and to maintain the rotational speed when power is transmitted from the motor 44 to the drive wheel 14. The speed converter device 70 can be located in the transmission hub 28. In this case, for example, the speed converter device is located in the power transmission path T between the second one-way clutch 46B and the second rotating body 24. The speed converter device 70 can, for example, utilize the structure of JP 2016-203735A.

[0065] The control unit 42 can operate the clutch mechanism 46 in the third state in a case where a predefined condition, other than the actuation of the actuating unit 30, is met. For example, the control unit 42 executes step S21 of Fig. 13 instead of step S11 in the process of Fig. 10 out. In the process of Fig. In step S21, the controller 42 determines whether a predetermined condition is met. If the predetermined condition is met, the controller 42 proceeds to step S21. If the predetermined condition is not met, the controller 42 proceeds to step S15. The predetermined condition includes, for example, a case in which the rotational speed N of the crank 12 is less than or equal to a predetermined speed and the vehicle speed V is greater than or equal to a first speed. In this case, for example, in a state where the crank 12 is stopped and the human-powered vehicle 10 is moving, regenerative braking is performed if the vehicle speed V becomes greater than or equal to the first speed.

[0066] In the embodiment and the modified examples, the first pawls 54 can each be movable between the first position and the second position in the second state. The first pawls 54 and the second pawls 56 can be in the same state as the first state. In particular, the first pawls 54 are each movable between the first position and the second position, and the second pawl 56 is held in the second position. In this case, too, no force is transmitted from the drive wheel 14 to the motor 44 when the drive wheel is rotated in the second direction A2. The control load of the controller 42 can be reduced if the states of the first pawls 54 and the second pawls 56 in the second state are the same as the first state. In this case, for example, steps S15 and S16 in the flowcharts of Fig. 10 and Fig. 13 is omitted, and the control 42 continues with step S17 if a negative determination is present in step S11 or step S21.

[0067] In the embodiment and the modified examples, in a case where the battery 32 does not supply power to the control unit 42, the coupling mechanism 46 can be operated in the second state, which is an output state.

[0068] In the embodiment and the modified examples, in a case where the battery 32 does not supply power to the control unit 42, the coupling mechanism 46 can operate in the third state, which is an output state.

[0069] In the embodiment and the modified examples, the control 42 can change the state of the clutch mechanism 46 according to an actuation of the actuating unit 30, which is other than the brake lever 30A.

[0070] The coupling mechanism 46 can be mechanically controlled by a wire which is actuated in cooperation with the brake wire, instead of controlling the coupling mechanism 46 by actuating the actuator 62 with the control 42.

[0071] In step S15 of the flowcharts of the Fig. 10 and Fig. The controller 42 can determine whether the product of the rotational speed N of the crank 12 and the gear ratio is less than the preset value. The preset value is a value that is less than the rotational speed of the wheel and is, for example, a value that is three-quarters of the rotational speed of the wheel. In this case, if the user increases the rotational speed N of the crank 12 to accelerate the human-powered vehicle 10, the rotational force of the crank 12 continues to be smoothly transmitted to the drive wheel 14. REFERENCE MARK 10 Human-powered vehicle 12 Crank 12A Crankshaft 12B crank arm 14 drive wheel 14A Hub housing 16 frames 16A front fork 16B handlebar stem 16C handlebars 18 Pedal 20 Drive mechanism 20A one-way coupling 20B output unit 22 First solid of revolution 24 Second Body of Revolution 26 Connecting element 28 Gear hub 30 Actuating unit 30A brake lever 30B Detector 32 battery 40 Drive system 42 Control 44 engine 44A drive unit 44B Drive Circuit 46 Clutch mechanism 46A First one-way coupling 46B Second one-way coupling 48 base 50 First element 52 Second Element 54 First locking pawl 56 Second locking pawl 58 Nut 60 storage 62 Actuator 64 Crankshaft position sensor 66 Vehicle speed sensor 68 Torque sensor 70 Speed ​​converter device A1 First direction A2 Second direction C1 axis of rotation S11 - S17 Step S21 step T Power transmission path T1 First power transmission path T2 Second power transmission path

Claims

[1] Drive system (40) for use in a human-powered vehicle (10) comprising a crank (12) into which human power is input and a drive wheel (14) which is driven by the human power, wherein the drive system (40) comprises: a coupling mechanism (46) which is provided in a power transmission path (T) from the crank (12) to the drive wheel (14); and a motor (44) which is arranged spaced apart from the drive wheel (14) and is connected to the drive wheel (14) via the coupling mechanism (46), wherein the motor (44) is configured to brake the drive wheel (14) in a case in which driving force is received from the drive wheel (14), wherein in a case in which the crank (12) is turned in a first direction (A1), the clutch mechanism (46) is operable in a first state in which the clutch mechanism (46) transmits the human driving force to the drive wheel (14) and turns the drive wheel (14) in a second direction (A2), in a case in which the drive wheel (14) is rotated in the second direction (A2), the clutch mechanism (46) can be operated in a second state in which the clutch mechanism (46) does not transmit any force from the drive wheel (14) to the motor (44), and in a case in which the drive wheel (14) is rotated in the second direction (A2), the clutch mechanism (46) can be operated in a third state in which the clutch mechanism (46) transmits a force from the drive wheel (14) to the motor (44), characterized by , that the clutch mechanism (46) is configured to not transmit the human driving force to the drive wheel (14) in the third state, even in a case where the crank (12) is turned in the first direction (A1). [2] Drive system (40) according to claim 1, wherein the motor (44) is configured to perform regenerative braking. [3] Drive system (40) according to claim 1 or 2, further comprising a control (42) which controls the coupling mechanism (46), wherein the control (42) operates the coupling mechanism (46) in the third state in a case in which a predetermined condition is met. [4] Drive system (40) according to claim 1 or 2, further comprising a control (42) which operates the clutch mechanism (46) in the third state in a case in which an actuating unit (30) provided on the human-powered vehicle (10) is actuated. [5] Drive system (40) according to claim 4, wherein the actuating unit (30) includes a brake lever (30A). [6] Drive system (40) according to any one of claims 1 to 5, wherein the motor (44) is configured to assist the propulsion of the human-powered vehicle (10) according to the human driving force in a case in which the crank (12) is turned in the first direction (A1). [7] Drive system (40) according to one of claims 1 to 6, wherein the motor (44) is arranged near the crank (12). [8] Drive system (40) according to any one of claims 1 to 7, further comprising: a base (48) which rotatably supports the crank (12), the motor (44) being provided on the base (48). [9] Drive system (40) according to any one of claims 1 to 8, wherein the coupling mechanism (46) includes a two-way coupling. [10] Drive system (40) according to claim 9, wherein: the coupling mechanism (46) includes a first element (50), a second element (52), a first locking pawl (54) which is provided on one of the first element (50) and the second element (52) and is configured to engage with the other of the first element (50) and the second element (52), and a second locking pawl (56) which is provided on one of the first element (50) and the second element (52) and is configured to engage with the other of the first element (50) and the second element (52); the first locking pawl (54) a first one-way coupling (46A) with the first element (50) and configured the second element (52); and the second pawl (56) a second one-way coupling (46B) with the first element (50) and configured the second element (52), wherein the second one-way coupling (46B) and the first one-way coupling (46A) rotate the first element (50) and the second element (52) in relatively different directions. [11] Drive system (40) according to one of claims 1 to 10, wherein the coupling mechanism (46) is provided on the drive wheel (14). [12] Drive system (40) according to claim 11, wherein the drive wheel (14) has a gear hub (28) and the clutch mechanism (46) is provided in the gear hub (28). [13] Drive system (40) according to one of claims 1 to 12, wherein the coupling mechanism (46) is provided near the crank (12). [14] Drive system (40) according to any one of claims 1 to 12, further comprising a speed converter device (70) provided in a power transmission path (T) from the drive wheel (14) to the motor (44), wherein the speed converter device (70) is configured to reduce the speed in a case where a force is transmitted from the drive wheel (14) to the motor (44), and the speed converter device (70) is configured to not change the speed in a case where a force is transmitted from the motor (44) to the drive wheel (14).

Images