JP2015217816A - Drive mechanism for bicycle and bicycle with drive mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To put a rear-wheel brake in a non-operating state when the vehicle moves back, without requiring a special rear-wheel hub, in a drive mechanism for the vehicle having a back pedal brake.SOLUTION: A drive mechanism for a bicycle comprises: a crank shaft in which the tread force of a rider is input; a rear-wheel drive member connected to the crank shaft via a first one-way clutch and engaged with a drive force transmission member that transmits drive force to a rear wheel; and a rear-wheel brake drive member connected to the crank shaft via a slip lock mechanism and drives the rear-wheel. The first one-way clutch transmits normal-direction drive force to the rear-wheel drive member from the crank shaft. The slip lock mechanism is brought to a free state when the rotations of the crank shaft and rear-wheel drive member synchronize, and brought to a locked state when the rotations of the crank shaft and rear-wheel drive member do not synchronize.

Description

  The present invention relates to a bicycle drive mechanism and a bicycle equipped with the drive mechanism.

  In a bicycle, there is a mechanism (back pedal brake) that operates a rear wheel brake by depressing a pedal in a reverse direction. As such a mechanism, a mechanism generally called a coaster brake (referred to as “coaster hub” in JIS D9201) is well known. The coaster hub incorporates a brake mechanism in the freewheel hub of the rear wheel, and the sprocket connected to the rear wheel hub is rotated in the reverse direction to move the clutch in the axial direction and press the brake shoe against the brake drum. Get.

  However, the coaster brake can not be used unless it has a structure that can transmit the rotational force in the reverse direction to the rear wheel hub. Therefore, for example, the coaster brake cannot be used for a bicycle having a structure in which a one-way clutch is provided between the crankshaft and the drive sprocket for some reason.

  Therefore, a mechanism that directly detects the reverse rotation of the crankshaft and activates the rear wheel brake can be considered, but if such a simple mechanism is employed, when the bicycle is moved backward, the crankshaft Since it rotates in reverse with the reverse rotation, there is a problem that the rear wheel brake operates.

  In Patent Document 1, in a mechanism for operating the rear wheel brake by detecting reverse rotation of the crankshaft, when the bicycle is moved backward, the wire 14 is pulled by the operation ring 23 attached to the hub of the rear wheel (drive wheel). , A mechanism for stopping the rear wheel brake by rotating the ring 11 of the pedal-crank assembly and causing the one-way clutch in the assembly to idle is described.

Japanese translation of PCT publication

  The present invention has been made based on such circumstances, and the problem is that a bicycle drive mechanism equipped with a back pedal brake does not require a special rear wheel hub, and does not require a rear wheel brake when the vehicle moves backward. Inactive.

  In order to solve the above problems, the present invention has various aspects in the present application, and the outline of typical aspects of these aspects is as follows.

  (1) A crankshaft to which an occupant's pedaling force is input, and a rear wheel drive member that is connected to the crankshaft via a first one-way clutch and engages with a drive force transmission member that transmits drive force to the rear wheels. And a rear wheel brake drive member that is connected to the crankshaft via a slip lock mechanism and drives a rear wheel brake, and the first one-way clutch is connected to the rear wheel drive member from the crankshaft. The slip lock mechanism is in a free state when the rotation of the crankshaft and the rear wheel drive member is synchronized, and the crankshaft and the rear wheel drive member Bicycle drive mechanism that locks when the rotation of the is asynchronous.

  (2) In (1), a torque sensor that detects torque input to the crankshaft, and a motor that applies auxiliary driving force to the rear wheel driving member based on torque detected by the torque sensor, Bicycle drive mechanism having.

  (3) In (1) or (2), the slip lock mechanism includes a first rotating member that rotates synchronously with the crankshaft, a second rotating member that rotates synchronously with the rear wheel brake drive member, and the first rotating member. A plurality of torque transmitting members disposed between the rotating member and the second rotating member; and a retainer disposed between the torque transmitting members, wherein the retainer and the rear wheel driving member rotate synchronously. Bicycle drive mechanism to be connected.

  (4) In (3), the retainer and the rear wheel drive member are connected via a second one-way clutch, and the second one-way clutch transmits reverse power from the rear wheel drive member to the retainer. Bicycle drive mechanism that transmits.

  (5) The bicycle drive mechanism according to (4), wherein the retainer and the rear wheel drive member are elastically connected by an elastic member.

  (6) In any one of (3) to (5), the surface of the second rotating member has concavities and convexities that engage with the torque transmitting member when the first rotating member rotates relatively in the opposite direction. Bicycle drive mechanism provided with structure.

  (7) The bicycle drive mechanism according to any one of (3) to (6), wherein the rear wheel brake drive member and the second rotation member are an integral member.

  (8) A bicycle equipped with the bicycle drive mechanism according to any one of (1) to (7).

  According to the above invention, in the bicycle drive mechanism provided with the back pedal brake, the rear wheel brake can be deactivated when the vehicle moves backward without requiring a special rear wheel hub.

It is a side view of the bicycle provided with the drive mechanism of the bicycle concerning a first embodiment of the present invention. It is a schematic diagram which shows the structure of a drive mechanism. It is the figure which showed the state of the bicycle and the operation state of each part of a drive mechanism in the table | surface. It is a partially broken perspective view which shows the structure of a drive mechanism. It is a vertical sectional view which passes through the central axis of the crankshaft of the drive mechanism. It is sectional drawing explaining the structure of the slip lock mechanism seen from the rotating shaft direction. In the 1st Embodiment of this invention, it is a partially broken perspective view of a slip lock mechanism which shows the modification which used the ratchet mechanism as a slip lock mechanism. It is a partially broken figure explaining the structure of the slip lock mechanism seen from the rotating shaft direction. It is the figure which showed the state of the bicycle and the operation state of each part of a drive mechanism in the table | surface. It is a schematic diagram which shows the structure of the drive mechanism which concerns on the 2nd Embodiment of this invention. It is the figure which showed the state of the bicycle and the operation state of each part of a drive mechanism in the table | surface. In the 2nd Embodiment of this invention, it is a partially broken fragmentary perspective view of the drive mechanism which shows the positional relationship of a 2nd one-way clutch and a slip lock mechanism. It is the partially broken view which looked at the connection ring which comprises the 2nd one-way clutch which concerns on the 2nd Embodiment of this invention from the slip lock mechanism side. It is the partially broken view which looked at the connection ring which comprises the 2nd one-way clutch which concerns on the 2nd Embodiment of this invention from the drive sprocket side. It is a figure explaining operation | movement of the slip lock mechanism which concerns on the 2nd Embodiment of this invention. It is a figure explaining operation | movement of the slip lock mechanism which concerns on the modification of the 2nd Embodiment of this invention.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a side view of a bicycle 1 having a bicycle drive mechanism 10 according to a first embodiment of the present invention. The bicycle 1 includes a drive structure 10 having a structure as a general bicycle, that is, a frame 2, a front wheel 3 and a rear wheel 4, a handle 5 and a saddle 6, and a foot pedal 11. In a general form, the rider steps on the pedal 11 of the driving mechanism 10 and transmits the driving force obtained by rotating the pedal crank 12 in the forward direction to the rear wheel 4 so that the bicycle 1 moves forward. Here, the “forward direction” refers to the direction of movement of each component when the bicycle 1 moves forward. On the other hand, the “reverse direction” indicates a direction opposite to the forward direction.

  The pedal crank 12 is a normal component similar to the component of the same name generally found in the bicycle 1, and is a component that connects the crankshaft 13 and the pedal 11. The pedal crank 12 is fixed in a non-rotatable manner with respect to the crankshaft 13 (that is, the pedal crank 12 and the crankshaft 13 rotate together), and the pedal 11 is fixed in a rotatable manner with respect to the pedal crank 12. The driving force by the occupant is transmitted to a drive sprocket 14 provided coaxially with the crankshaft 13 and further transmitted to a driven sprocket 16 via a chain 15. As a result, the rear wheel hub 17 rotates, and the rear wheel 4 attached to the rear wheel hub 17 rotates in the forward direction. The rear wheel hub 17 is a so-called free wheel hub that is generally used for bicycles, and transmits a forward driving force from the driven sprocket 16 to the rear wheel hub 17 but does not transmit a reverse driving force. A one-way clutch mechanism is provided.

  The drive mechanism 10 shown in FIG. 1 includes an electric motor 18 that assists the pedaling force of the passenger and a battery 19 that is a power source thereof. The electric motor 18 applies assist torque to the drive sprocket 14 in accordance with the pedaling force of the passenger. In the present embodiment, the assist sprocket 20 around which the chain 15 is wound is rotated by the electric motor 18 so that the chain 15 is pulled in the forward direction to give assist torque to the drive sprocket 14. In addition, the mechanism in which the electric motor 18 gives the assist torque to the drive sprocket 14 is not particularly limited, and other mechanisms that directly give the assist torque to the drive sprocket 14 may be used. Parts such as the electric motor 18 and the assist sprocket 20 are covered with an electric motor cover 21, and the upper portions of the drive sprocket 14 and the chain 15 are covered and protected by a chain cover 22, and the driving mechanism 10 for the occupant's body and clothes. Prevents inward entrainment.

  In the present embodiment, the forward drive force from the crankshaft 13 to the drive sprocket 14 is transmitted between the crankshaft 13 and the drive sprocket 14 for the convenience of the electric motor 18 giving assist torque to the drive sprocket 14. However, a one-way clutch mechanism (hereinafter referred to as a first one-way clutch) that does not transmit the driving force in the reverse direction is incorporated. Therefore, even if the passenger rotates the pedal 11 in the reverse direction, the rotational force is not transmitted to the drive sprocket 14.

  In the above description, the bicycle 1 is shown as a so-called electric assist bicycle that includes the electric motor 18 and the battery 19 and applies assist torque according to the pedaling force of the passenger. However, the bicycle 1 is not necessarily a type of power assist. Alternatively, the bicycle may be of a type that does not have any assist mechanism and runs only by human power. However, even in this case, the present embodiment is intended for the one provided with the above-described first one-way clutch between the crankshaft 13 and the drive sprocket 14.

  Further, the driving mechanism 10 of the bicycle 1 does not necessarily need to use a mechanism using the chain 15 as shown here to transmit the driving force to the rear wheel 4, and other mechanisms such as a belt or a shaft may be used. The mechanism used may be used. Even in that case, the bicycle 1 is engaged with the driving force transmitting member for transmitting the driving force to the rear wheel 4 and the rear wheel driving for engaging with the driving force transmitting member and transmitting the rotation of the crankshaft 13. It has at least a member. In this embodiment, the chain 15 corresponds to the driving force transmission member and the drive sprocket 14 corresponds to the rear wheel driving member. However, in the belt driving system, the belt corresponds to the driving force transmission member and the pulley corresponds to the rear wheel driving member. In the drive system, the shaft corresponds to the driving force transmission member, and the bevel gear corresponds to the rear wheel driving member.

  In the present embodiment, a so-called back pedal brake mechanism that incorporates a brake by rotating the pedal 11 in the reverse direction is incorporated in the drive mechanism 10. Here, the back pedal brake mechanism applies a brake to the rear wheel 4. When the brake arm 23 provided coaxially with the crankshaft 13 is reversed, the brake wire 24 is pulled, and the drum attached to the rear wheel 4. The brake 25 is activated. The type of rear wheel brake attached to the rear wheel 4 is not particularly limited. The drum brake 25 is an example of a rear wheel brake. Further, the rear wheel brake driving member that is a member for operating the rear wheel brake is not limited to the brake arm 23 as shown here. As long as the rear wheel brake can be operated, its shape and form are not limited. The brake arm 23 is an example of a rear wheel brake drive member.

  Although the front wheel brake is not shown in FIG. 1, an appropriate type of brake mechanism may be provided as necessary.

  FIG. 2 is a schematic diagram illustrating the configuration of the drive mechanism 10. A pedal crank 12 and a pedal 11 are attached to both ends of the crankshaft 13 (only one of them is shown in the figure). A drive sprocket 14 is attached to the crankshaft 13 via a first one-way clutch 26. A chain 15 is wound around the drive sprocket 14, and the chain 15 is wound around a driven sprocket 16. The rear wheel hub 17 is provided coaxially with the driven sprocket 16. Similarly, a brake arm 23 is attached to the crankshaft 13 via a slip lock mechanism 27.

  Furthermore, the crankshaft 13 is provided with a torque sensor 28, detects the torque acting on the crankshaft 13, and the controller 29 controls the electric motor 18 based on the detection result. To be added.

  Here, the arrows shown in the first one-way clutch 26 and the rear wheel hub 17 indicate the power transmission direction, the solid line arrow indicates the forward power transmission direction, and the broken arrow indicates the reverse power transmission. Indicates direction. That is, the first one-way clutch 26 is locked when the crankshaft 13 tries to rotate in the forward direction with respect to the drive sprocket 14, and transmits the rotational force of the crankshaft 13 to the drive sprocket 14. In the case of rotating in the reverse direction with respect to 14, the free state is entered, and the crankshaft 13 is idled. When viewed from the drive sprocket 14 side, the first one-way clutch 26 is locked when the drive sprocket 14 attempts to rotate in the reverse direction relative to the crankshaft 13, and free when the drive sprocket 14 attempts to rotate in the forward direction. It becomes.

  On the other hand, the slip lock mechanism 27 is interposed between the crankshaft 13 and the brake arm 23, and the rotation of the drive sprocket 14 is also input. The operation of the slip lock mechanism 27 is in a free state when the rotation of the crankshaft 13 and the drive sprocket 14 is synchronized, that is, when both are rotating together (or both are stopped). Thus, when the rotation of the crankshaft 13 and the drive sprocket 14 is asynchronous, that is, when there is a slip between the two rotations, the locked state is established.

  The operation of the drive mechanism 10 will be described with further reference to FIG. FIG. 3 is a table showing the state of the bicycle 1 and the operating state of each part of the drive mechanism 10. In the figure, the vertical column indicates the state of the bicycle 1, the horizontal column indicates the operation state of each part, "FW" in the table indicates the forward operation, "RW" indicates the reverse operation, and "N "" Indicates a stopped state or a free rotation state, "LOCK" indicates that the first one-way clutch 26 or the slip lock mechanism 27 is in a locked state, and "FREE" indicates that it is in a free state.

  First, consider a state in which a passenger rides the pedal 11 of the bicycle 1 in the forward direction and the bicycle 1 is traveling forward. The crankshaft 13 is rotated in the forward direction by the pedaling force transmitted from the pedal 11 via the pedal crank 12, and the first one-way clutch 26 is locked, so that the drive sprocket 14 is also rotated in the forward direction. The driven sprocket 16 also rotates in the forward direction via the chain 15, and the driving force is transmitted to the rear wheel hub 17. The rear wheel hub 17 rotates in the forward direction, so that the rear wheel 4 of the bicycle 1 moves in the forward direction. Rotate to.

  At this time, since the first one-way clutch 26 is locked and the rotation of the crankshaft 13 and the drive sprocket 14 is synchronized, the slip lock mechanism 27 is in a free state, the brake arm 23 does not rotate, and the drum brake 25 also operates. do not do.

  Further, the electric motor 18 generates an assist torque corresponding to the torque acting on the crankshaft 13 and causes the drive sprocket 14 to act.

  Next, consider a state in which the bicycle 1 is traveling with inertia, that is, the bicycle 1 is traveling forward with inertia (or downhill) but the passenger is not stroking the pedal 11. Since the crankshaft 13 does not rotate, the drive sprocket 14 also does not rotate, and the first one-way clutch 26 is in a free state. The rear wheel hub 17 rotates in the forward direction as the rear wheel 4 rotates, but the rotation is not transmitted to the driven sprocket 16 and the driven sprocket 16 does not rotate either.

  At this time, since the crankshaft 13 and the drive sprocket 14 do not rotate, the slip lock mechanism 27 enters a free state, the brake arm 23 does not rotate, and the drum brake 25 does not operate.

  The electric motor 18 does not generate assist torque because no torque acts on the crankshaft 13.

  Further, consider a state in which the passenger rides the pedal 11 of the bicycle 1 in the reverse direction and applies the back pedal brake. The crankshaft 13 rotates in the reverse direction according to the pedaling force applied to the pedal 11. However, this rotation is not transmitted to the drive sprocket 14 because the first one-way clutch 26 is in a free state. The drive sprocket 14 is in a free rotating state and does not normally rotate. The driven sprocket 16 is also not rotated. The rear wheel hub 17 rotates in the forward direction when the bicycle 1 is traveling with inertia, and does not rotate when the bicycle 1 is stopped. In any case, the state of the rear wheel hub 17 is not transmitted to the driven sprocket 16.

  At this time, the crankshaft 13 rotates in the opposite direction, while the drive sprocket 14 does not rotate, and the rotation of both does not synchronize, so the slip lock mechanism 27 is locked. Thereby, the rotational force in the reverse direction is transmitted from the crankshaft 13 to the brake arm 23, the brake arm 23 rotates in the reverse direction, and the drum brake 25 operates.

  The electric motor 18 does not generate assist torque because reverse torque acts on the crankshaft 13.

  Finally, let us consider a state in which the bicycle 1 is retracted, that is, a state in which the passenger gets off the bicycle 1 and pushes the bicycle 1 backward. At this time, the rear wheel hub 17 rotates in the reverse direction in synchronization with the rear wheel 4, and the rotation is transmitted to the driven sprocket 16, so the driven sprocket 16 rotates in the reverse direction. Furthermore, the drive sprocket 14 also rotates in the opposite direction via the chain 15. When the drive sprocket 14 rotates in the reverse direction, the first one-way clutch 26 is locked, so that the crankshaft 13 also rotates in the reverse direction.

  Here, the crankshaft 13 and the drive sprocket 14 rotate in the reverse direction in synchronization because the first one-way clutch 26 is locked. Therefore, since the slip lock mechanism 27 is in a free state, the reverse rotation is not transmitted to the brake arm 23, and the brake arm 23 does not rotate and the drum brake 25 does not operate.

  The electric motor 18 naturally does not generate assist torque in this case.

  As described above, the bicycle lock 1 according to the present embodiment can operate the back pedal brake when the bicycle 1 is running or stopped by the action of the slip lock mechanism 27, and when the bicycle 1 is moved backward, the drum 1 The brake 25 does not act, and the bicycle 1 can be moved backward smoothly. The rear wheel hub 17 may be a general freewheel hub and is not a special product.

  Subsequently, an example of a specific mechanism of the drive mechanism 10 will be described with reference to FIGS.

  FIG. 4 is a partially broken perspective view showing the configuration of the drive mechanism 10. FIG. 5 is a vertical sectional view passing through the central axis of the crankshaft 13 of the drive mechanism 10.

  The first one-way clutch 26 incorporated between the crankshaft 13 and the drive sprocket 14 includes an outer cylinder 30 that rotates integrally with the crankshaft 13, an inner cylinder 31 that is rotatably supported by the crankshaft 13, and an outer cylinder. 30 and a ratchet pawl 32 disposed between the inner cylinder 31 and the inner cylinder 31. Here, the first one-way clutch 26 is shown as a ratchet type, but other types such as a cam type and a sprag type may be used.

  The drive sprocket 14 and the connection ring 33 are fixed to the inner cylinder 31, and these members rotate together. These integrally rotating parts may be created as separate members as shown here, and may be assembled together, or may be created together as an integral part. The same applies to the following description. A recess 34 into which a retainer 37 described later is inserted is formed on the side surface of the connection ring 33 facing the slip lock mechanism 27.

  The slip lock mechanism 27 includes an axle adapter 35 that rotates integrally with the crankshaft 13, a brake arm 23 that is rotatably supported by the crankshaft 13, and a roller 36 that is disposed between the axle adapter 35 and the brake arm 23. A retainer 37 is included. A cam surface 38 that pushes the roller 36 radially outward is formed on a part of the outer peripheral surface of the axle adapter 35, and a roller contact surface 39 that contacts the roller 36 is formed on a part of the inner peripheral surface of the brake arm 23. Is formed. The retainer 37 is a member that is disposed between the rollers 36 and maintains a distance so that adjacent rollers 36 do not contact each other. A part of the retainer 37 extends in the direction of the first one-way clutch 26, and the recess 34 of the connection ring 33 is provided. In the recess 34, the spring 40 is elastically connected to the connection ring 33. Thereby, the connection ring 33 and the retainer 37 are connected to rotate synchronously. Since the connection ring 33 and the drive sprocket 14 rotate as a unit, the drive sprocket 14 and the retainer 37 are connected to rotate synchronously. However, since the spring 40 is an elastic body and can be deformed to some extent, the drive sprocket 14 and the retainer 37 do not always rotate together, and there is a slight displacement in the rotational direction. Permissible.

  The pedal adapter 12 is attached to the axle adapter 35 so as to rotate integrally. Since the axle adapter 35 and the crankshaft 13 rotate integrally, the pedal crank 12 rotates together with the crankshaft 13. The pedal crank 12 may be directly attached to the crankshaft 13 without the axle adapter 35 being interposed.

  FIG. 6 is a cross-sectional view illustrating the structure of the slip lock mechanism 27 as viewed from the direction of the rotation axis. As illustrated, both ends of the spring 40 are engaged with the connection ring 33 and the retainer 37, respectively. Therefore, in the slip lock mechanism 27, when the connection ring 33 and the axle adapter 35 are rotating synchronously or both are not rotating, the retainer 37 is maintained at a predetermined position by the action of the spring 40. . In such a state, the roller 36 is not pushed radially outward by the cam surface 38, and the brake arm 23 is placed in a freely rotatable state with respect to the axle adapter 35. That is, in this state, the brake arm 23 is in a free state with respect to the crankshaft 13.

  Here, when the crankshaft 13 and the drive sprocket 14 rotate relative to each other so that the rotation of the connection ring 33 and the axle adapter 35 becomes asynchronous, the axle adapter 35 is moved within the range of elastic deformation of the spring 40 with respect to the connection ring 33. The cam surface 38 drives the roller 36 radially outward. As a result, the roller 36 is engaged between the roller contact surface 39 and the cam surface 38 of the brake arm 23, and the brake arm 23 rotates integrally with the axle adapter 35. That is, in this state, the brake arm 23 is locked with respect to the crankshaft 13.

  The cam profile of the cam surface 38 may have a shape that does not depend on the rotation input direction, for example, each surface may be a simple plane. However, in this embodiment, the cam profile is asymmetric with respect to the rotation direction as shown in FIG. When the crankshaft 13 rotates in the reverse direction, the cam surface 38 pushes up the roller 36 and locks it, whereas when the crankshaft 13 rotates in the forward direction, the cam surface 38 rotates the roller 36. The cam profile is set to idle without pushing up.

  In the above description, the slip lock mechanism 27 has been described as using a cam roller mechanism, but other mechanisms may be used. FIG. 7 is a partially broken perspective view of the slip lock mechanism 27 showing a modification using a ratchet mechanism as the slip lock mechanism 27 in the present embodiment, and FIG. 8 is a slip lock mechanism viewed from the direction of the rotation axis. FIG.

  In this modification, in place of the roller 36 of the previous example, ratchet claws 41 are provided on the outer peripheral surface of the axle adapter 35 at a predetermined interval. A retainer 37 is inserted between the adjacent ratchet claws 41. Further, a coil spring 42 is provided between the retainer 37 and each ratchet pawl 41 and urges the ratchet pawl 41 to open in the outer circumferential direction. Further, the meshing surface 43 that is an inner peripheral surface that comes into contact with the ratchet pawl 41 of the brake arm 23 is provided with a step so as to mesh with the ratchet pawl 41 when the axle adapter 35 rotates reversely. The retainer 37 and the connection ring 33 are elastically connected by a spring 40 and are rotated in synchronization.

  In the slip lock mechanism 27 according to this modification, the crankshaft 13 rotates in the reverse direction with respect to the drive sprocket 14, so that the rotation of the connection ring 33 and the axle adapter 35 becomes asynchronous, and the axle adapter 35 with respect to the connection ring 33. When the rotation direction is reverse, the retainer 37 presses the ratchet pawl 41 outward by the action of the spring 40, that is, in the clockwise direction in FIG. As a result, the tip of the ratchet pawl 41 engages with the step of the engagement surface 43, and the brake arm 23 rotates integrally with the axle adapter 35. That is, in this state, the brake arm 23 is locked with respect to the crankshaft 13.

  On the other hand, when the connection ring 33 and the axle adapter 35 are rotating synchronously or both are not rotating, the retainer 37 closes the ratchet pawl 41 inward by the action of the spring 40, that is, In the figure, it is pressed counterclockwise. As a result, the ratchet pawl 41 is closed, the tip of the ratchet pawl 41 does not mesh with the step of the meshing surface 43, and the brake arm 23 is placed in a freely rotatable state with respect to the axle adapter 35. That is, in this state, the brake arm 23 is in a free state with respect to the crankshaft 13.

  Also in this modified example, as in the previous example, the slip lock mechanism 27 is synchronized with the rotation of the crankshaft 13 and the drive sprocket 14, that is, when both are rotating together or both are stopped. The crankshaft 13 and the drive sprocket 14 are asynchronous, i.e., there is a slip between the rotations of the crankshaft 13 and the drive sprocket 14.

  In the above examples and modifications, the slip lock mechanism 27 has been described using a cam roller mechanism and a ratchet mechanism. However, another mechanism such as a sprag mechanism may be used. Good. In any case, in the specific example of the slip lock mechanism 27 used in the present embodiment, the first rotating member that rotates synchronously with the crankshaft 13 and the second rotating member that rotates synchronously with the brake arm 23 that is the rear wheel brake driving member. In this case, a plurality of torque transmission members are disposed between the first rotation member and the second rotation member, and a retainer is disposed between the torque transmission members. The drive sprocket 14 is a retainer and a rear wheel drive member. Are designed to be elastically connected to rotate synchronously.

  In the previous example, the roller 36 corresponds to the torque transmission member, and in the modification, the ratchet pawl 41 corresponds to the torque transmission member. If a sprag mechanism is employed, the sprag will correspond to the torque transmission member. In any example, the axle adapter 35 corresponds to the first rotating member, and the portion where the roller contact surface 39 or the meshing surface 43 of the brake arm 23 is provided corresponds to the second rotating member. Of course, even if the brake arm 23 is divided and a portion corresponding to the arm to which the brake wire 24 is attached and a portion corresponding to the second rotating member are separately created and fixed together so that both of them rotate synchronously later. There is no problem. However, in the present embodiment, the brake arm 23 is manufactured as an integral member, thereby reducing the number of parts and the cost.

  By the way, in the bicycle 1 provided with the bicycle drive mechanism 10 according to the first embodiment described above, there is a concern that the behavior of the bicycle 1 may become unintended depending on the control of the electric motor 18 by the controller 29. Such behavior will be described with reference to FIG.

  FIG. 4 is a table showing the state of the bicycle 1 and the operation state of each part of the drive mechanism 10 according to FIG. What is concerned here is the state in which the assist torque by the electric motor 18 is acting on the drive sprocket 14. At this time, a state is considered in which the forward rotational speed of the crankshaft 13 exceeds the forward rotational speed of the drive shaft 13 for some reason, such as when the passenger stops pedaling (for example, “ FW> Crankshaft ”). At this time, the crankshaft 13 rotates or stops in the forward direction at a slower speed than the drive sprocket 14, and no driving force is transmitted to the drive sprocket 14, so the first one-way clutch 26 is in a free state. . The driven sprocket 16 and the rear wheel hub 17 rotate in the forward direction according to the drive sprocket 14.

  When the operation of the slip lock mechanism 27 at this time is considered with reference to FIG. 6, the connection ring 33 interlocked with the drive sprocket 14 rotates in the forward direction with respect to the axle adapter 35 interlocked with the crankshaft 13. At this time, the retainer 37 also tries to rotate in the forward direction in the same manner as the connection ring 33 due to the action of the spring 40. Then, the roller 36 is pushed by the retainer 37 and also tries to rotate in the forward direction with respect to the axle adapter 35.

  As a result, the roller 36 pushes the cam surface 38 of the axle adapter 35 in the forward direction, and torque for rotating in the forward direction is transmitted to the crankshaft 13 (shown as “Half LOCK” in the drawing). Further, the forward torque applied to the crankshaft 13 cannot be determined by the torque sensor 28 shown in FIG. Therefore, if the controller 29 is not appropriately controlled so as not to generate an assist torque that causes the drive sprocket 14 to rotate at a speed exceeding the crankshaft 13, the motor 18 generates the assist torque regardless of the pedal operation of the passenger. It can be a situation that keeps generating.

  Of course, this behavior is not intended by the passenger, and can be prevented by the control of the controller 29. However, in the second embodiment of the present invention described below, the occurrence of the above-described situation is mechanically affected. This is also prevented by the mechanism. Hereinafter, the bicycle 1 provided with the drive mechanism 10 according to the second embodiment of the present invention will be described with reference to FIGS.

  FIG. 10 is a schematic diagram showing the configuration of the drive mechanism 10 according to the second embodiment of the present invention. In addition, since the external shape of the bicycle 1 according to the present embodiment is not particularly different from that of the previous embodiment, FIG. 1 illustrated as that of the bicycle 1 according to the previous embodiment is the bicycle according to the present embodiment. Incorporated as one. In the present embodiment, the same or equivalent members as those in the previous embodiment are denoted by the same reference numerals, and redundant description thereof will be omitted.

  In the drive mechanism 10 shown here, the difference from that shown in FIG. 2 is that when the rotation of the drive sprocket 14 is input to the slip lock mechanism 27, the second one-way clutch 44 is interposed. The force transmission direction is limited. The power transmission direction of the second one-way clutch 44 is the same as that of the first one-way clutch 26. That is, the drive force in the reverse direction is transmitted from the drive sprocket 14 to the retainer 37 of the slip lock mechanism 27, but the drive force in the forward direction is not transmitted. Of course, this means that the forward driving force from the retainer 37 of the slip lock mechanism 27 to the drive sprocket 14 is transmitted at the same time, but the reverse driving force is not transmitted.

  The operation of the drive mechanism 10 according to the present embodiment will be described with further reference to FIG. FIG. 11 is a table showing the state of the bicycle 1 and the operating state of each part of the drive mechanism 10 as in FIG.

  When the rider rides the pedal 11 of the bicycle 1 in the forward direction and the bicycle 1 is traveling forward, the first one-way clutch 26 is locked and the drive sprocket 14 is also rotated in the forward direction, and the chain 15, driven sprocket The rear wheel hub 17 rotates in the forward direction via 16. At this time, the second one-way clutch 44 is in a free state, and the retainer 37 of the slip lock mechanism 27 is also in a free-rotatable state. At this time, referring to FIG. 6, the axle adapter 35 of the slip lock mechanism 27 rotates in the forward direction, and the cam surface 38 idles without pushing up the roller 36 as described above. As shown in FIG. 5, the drum brake 25 does not operate. The same applies to the case where the slip lock mechanism 27 uses a ratchet mechanism as shown in the previous modification or a sprag mechanism.

  When the bicycle 1 is running in inertia, the rotation of the rear wheel 4 is not transmitted from the rear wheel hub 17 to the upstream mechanism, and the crankshaft 13, the drive sprocket 14, and the driven sprocket 16 are all rotated. Of course, the drum brake 25 is not actuated by the brake arm 23. The first one-way clutch 26, the second one-way clutch 44, and the slip lock mechanism 27 are all in a free state.

  In a state where the rider pedals the pedal 11 of the bicycle 1 in the reverse direction, the crankshaft 13 rotates in the reverse direction, and the first one-way clutch 26 becomes free and the drive sprocket 14 does not rotate. Since the rotation of the crankshaft 13 and the drive sprocket 14 is not synchronized, the slip lock mechanism 27 is locked. Thereby, the rotational force in the reverse direction is transmitted from the crankshaft 13 to the brake arm 23, the brake arm 23 rotates in the reverse direction, and the drum brake 25 operates.

  The details of the operation of locking the slip lock mechanism 27 will be described later.

  Further, when the bicycle 1 is moved backward, the rear wheel hub 17, the driven sprocket 16, the drive sprocket 14, and the crankshaft 13 are rotated in the reverse direction in synchronization with the rear wheel 4, and the first one-way clutch 26 and the second Both one-way clutches 44 are locked. However, since the crankshaft 13 and the drive sprocket 14 rotate in the reverse direction synchronously, the slip lock mechanism 27 is in a free state and the drum brake 25 does not operate.

  Finally, let us consider a state in which the forward rotation speed of the crankshaft 13 exceeds the forward rotation speed of the drive sprocket 14 for some reason. At this time, the first one-way clutch 26 is in a free state, and the drive sprocket 14 rotates relative to the crankshaft 13 in the forward direction. Therefore, the second one-way clutch 44 is in a free state, the rotation of the drive sprocket 14 is not transmitted to the slip lock mechanism 27, and the slip lock mechanism 27 is also in a free state. Therefore, the torque generated by the electric motor 18 is not transmitted to the crankshaft 13 and is not detected by the torque sensor 28. In this case, the controller 29 depends only on the occupant's pedaling force for assistance by the electric motor 18. Therefore, the behavior of the bicycle 1 does not become unintended.

  Further, as a secondary effect of the mechanism of the drive mechanism 10 according to the present embodiment, it is possible to easily realize the electric push walking. The electric push-walking means that the electric motor 18 is temporarily driven by an explicit operation such as pressing a switch while the passenger gets off the bicycle 1, and the bicycle 1 is advanced by the electric motor power without pedaling 11. Refers to an operation.

  In the drive mechanism 10 according to the first embodiment described above, the drive sprocket 14 and the retainer 37 are elastically coupled by the spring 40. Therefore, when the drive sprocket 14 rotates in the forward direction, the retainer 37 causes the roller 36 to move. The slip lock mechanism 27 is locked by moving in the forward direction. Therefore, the crankshaft 13 rotates in the forward direction, and as a result, the pedal crank 12 and the pedal 11 rotate in the forward direction.

  On the other hand, in the drive mechanism 10 according to the second embodiment, even if the drive sprocket 14 rotates, the first one-way clutch 26 and the second one-way clutch 44 are both free, so the crankshaft 13 As a result, the pedal crank 12 and the pedal 11 do not rotate. Therefore, the pedal crank 12 and the pedal 11 do not interfere with the passenger who is pushing the bicycle 1, and a comfortable operation is possible.

  FIG. 12 is a partially broken partial perspective view of the drive mechanism 10 showing the positional relationship between the second one-way clutch 44 and the slip lock mechanism 27 in the present embodiment. As shown in the figure, in the drive mechanism 10 according to the present embodiment, the connection ring 33 is divided into a first connection ring 45 and a second connection ring 46, and the first connection ring 45 and the second connection ring 46 are divided. The connection ring 33 itself functions as the second one-way clutch 44 by a ratchet mechanism provided between the connection rings 46. FIG. 12 shows a state in which the first connection ring 45 is disposed inside the second connection ring 46 and the ratchet pawl 47 is disposed between them. However, the arrangement relationship between the inside and outside of the first connection ring 45 and the second connection ring 46 is not limited, and the mechanism of the second one-way clutch 44 is a mechanism other than the ratchet mechanism, such as a cam roller mechanism or a sprag mechanism. It may be. Furthermore, the second one-way clutch 44 may be provided separately from the connection ring 33 and connected to each other.

  FIG. 13A is a partially cutaway view of the connection ring 33 constituting the second one-way clutch 44 according to the present embodiment as viewed from the slip lock mechanism 27 side, and FIG. 13B constitutes the second one-way clutch 44 according to the present embodiment. It is the partially broken figure which looked at the connection ring 33 to perform from the drive sprocket 14 side.

  The first connection ring 45 and the second connection ring 46 have a concavo-convex shape so as to mesh with each other in the axial direction, and the ratchet pawl 47 is disposed in the gap. The ratchet pawl 47 is urged to open outward by a spring 48. Further, on the surface of the second connection ring 46 on the slip lock mechanism 27 side, a recess 34 into which an extension of the retainer 37 is inserted, and a spring fixing portion 49 that engages with the end of the spring 40 are formed. . On the surface of the first connection ring 45 on the drive sprocket 14 side, there is a dog 50 that is a protrusion that fits with the drive sprocket 14 and rotates together with the first connection ring 45 and the drive sprocket 14. Is provided.

  FIG. 14 is a view for explaining the operation of the slip lock mechanism 27 according to the present embodiment. This figure is a view of the internal structure of the slip lock mechanism 27 viewed from the axial direction, and at the same time, the structure of the second one-way clutch 44 is indicated by a broken line.

  The direction in which the slip lock mechanism 27 is locked in the figure is the direction in which the axle adapter 35 rotates in the reverse direction, and is counterclockwise in the figure. At this time, a force that moves counterclockwise also acts on the roller 36 that is in contact with the cam surface 38, and accordingly, a counterclockwise torque acts on the retainer 37 as a whole. This torque is transmitted to the second connection ring 46 via the spring 40 and tries to rotate the second connection ring 46 counterclockwise. Since this direction is a direction in which the ratchet pawl 47 is released, the second one-way clutch 44 is in a free state.

  Here, when the axle adapter 35, the roller 36, the retainer 37, the spring 40, and the second connection ring 46 all rotate in complete synchronization, the cam surface 38 cannot push the roller 36 outward, and slip lock The mechanism 27 will not lock.

  However, in the mechanism shown in FIG. 14, when the axle adapter 35 rotates in the reverse direction, the roller 36 does not rotate immediately because of inertia. Further, since the spring 40 is elastically deformed, a rotational torque in the reverse direction is transmitted to the second connection ring 46, and there is a delay until the second connection ring 46 starts to rotate counterclockwise. Therefore, a reaction force is generated on the retainer 37 against the torque that tries to rotate the roller 36 together with the axle adapter 35 in the reverse direction. Further, the mechanical resistance such as the rolling resistance of the roller 36 and the rotational resistance of the second connection ring 46 also acts as a reaction force against the torque that tries to rotate the roller 36 together with the axle adapter 35 in the opposite direction. For this reason, when the axle adapter 35 rotates in the opposite direction, the roller 36 does not immediately rotate around the axis but is pushed outward by the cam surface 38 and is caught between the roller contact surface 39 and the axle adapter 35. The rotation between the brake arms 23 is locked.

  By the way, in the structure shown here, the rotational resistance of the roller 36 with respect to the rotation of the axle adapter 35 is only the inertia of each member and the mechanical resistance inside the slip lock mechanism 27 and the second one-way clutch 44. If the roller 36 does not fully engage between the surface 38 and the roller contact surface 39, the roller 36 may slide on the surface of the roller contact surface 39, and the slip lock mechanism 27 may be insufficiently locked. .

  FIG. 15 is a diagram for explaining the operation of the slip lock mechanism 27 according to a modification of the present embodiment. 14 is a view of the internal structure of the slip lock mechanism 27 as viewed from the axial direction, and at the same time, the structure of the second one-way clutch 44 is indicated by a broken line.

  In this modification, the shape of the roller contact surface 39 of the slip lock mechanism 27 provided on the brake arm 23 is not a mere cylindrical surface, and the axle adapter 35 is relatively opposite to the previous example. The difference is that the surface is provided with an uneven structure that engages with the roller 36 when rotated. In other words, the roller contact surface 39 is provided with a step in a direction in which the roller 36 is caught when trying to rotate in the opposite direction with respect to the rotation axis.

  Therefore, the roller 36 is once pushed upward by the cam surface 38 and is caught by the step when the roller 36 comes into contact with the roller contact surface 39. For this reason, once the roller 36 comes into contact with the roller contact surface 39, the roller 36 does not slide on the surface of the roller contact surface 36, and the lock by the slip lock mechanism 27 becomes strong. The brake arm 23 does not slide on each other.

  Although the present invention has been described above by taking specific embodiments as examples, the present invention is not limited to the specific configurations in these illustrated specific examples. The specific arrangement, shape, number, and the like of each member shown in the embodiments are merely examples, and those skilled in the art can appropriately design and change them in view of various circumstances as long as they have the same technical effects as described here. It's okay.

1 Bicycle, 2 Frame, 3 Front wheel, 4 Rear wheel, 5 Handle, 6 Saddle, 10 Drive mechanism, 11 Pedal, 12 Pedal crank, 13 Crankshaft, 14 Drive sprocket, 15 Chain, 16 Driven sprocket, 17 Rear wheel hub, 18 motor, 19 battery, 20 assist sprocket, 21 motor cover, 22 chain cover, 23 brake arm, 24 brake wire, 25 drum brake, 26 first one-way clutch, 27 slip lock mechanism, 28 torque sensor, 29 controller, 30 Outer cylinder, 31 Inner cylinder, 32 Ratchet claw, 33 Connection ring, 34 Recessed part, 35 Axle adapter, 36 Roller, 37 Retainer, 38 Cam surface, 39 Roller contact surface, 40 Spring, 41 Ratchet claw, 42 Coil spring, 3 engaging surface, 44 second one-way clutch, 45 first connecting ring, 46 a second connecting ring, 47 the ratchet pawls 48 spring, 49 spring fixing portion, 50 dogs.

Claims (8)

A crankshaft to which the occupant's pedaling force is input;
A rear wheel drive member connected to the crankshaft via a first one-way clutch and engaged with a driving force transmission member for transmitting a driving force to the rear wheel;
A rear wheel brake driving member connected to the crankshaft via a slip lock mechanism and driving a rear wheel brake;
Have
The first one-way clutch transmits a forward driving force from the crankshaft to the rear wheel driving member,
The slip lock mechanism is in a free state when the rotation of the crankshaft and the rear wheel drive member is synchronized, and is in a locked state when the rotation of the crankshaft and the rear wheel drive member is asynchronous. Drive mechanism. A torque sensor for detecting torque input to the crankshaft;
A motor for applying an auxiliary driving force to the rear wheel driving member based on the torque detected by the torque sensor;
The drive mechanism for a bicycle according to claim 1, comprising: The slip lock mechanism is
A first rotating member that rotates synchronously with the crankshaft;
A second rotating member that rotates synchronously with the rear wheel brake driving member;
A plurality of torque transmitting members disposed between the first rotating member and the second rotating member;
A retainer disposed between the torque transmitting members;
Have
The bicycle drive mechanism according to claim 1 or 2, wherein the retainer and the rear wheel drive member are connected to rotate synchronously. The retainer and the rear wheel drive member are connected via a second one-way clutch,
The second one-way clutch transmits reverse power from the rear wheel drive member to the retainer.
The bicycle drive mechanism according to claim 3.   The bicycle drive mechanism according to claim 4, wherein the retainer and the rear wheel drive member are elastically connected by an elastic member.   The uneven structure which engages with the said torque transmission member when the said 1st rotation member rotates to a reverse direction relatively is provided in the surface of the said 2nd rotation member. Bicycle drive mechanism.   The bicycle drive mechanism according to any one of claims 3 to 6, wherein the rear wheel brake drive member and the second rotation member are an integral member.   A bicycle equipped with the bicycle drive mechanism according to claim 1.

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