TW201325986A - External shifting mechanism for electrical bicycle - Google Patents

Abstract

The invention relates to an external shifting mechanism for an electrical bicycle, mainly providing an unidirectional device that is configured between a large teeth plate and a crankshaft and capable of being driven by the crankshaft to rotate the large teeth plate in an unidirectional direction, so that a rear wheel, the large teeth plate and a chain can be rotated at the same speed. A sensing device is provided to sense the rotational speed of the rear wheel, the large teeth plate or the chain. Once the rotational speed of the rear wheel, the large teeth plate or the chain is too low or less than a preset value, the function of an electronic derailleur is terminated, and a rider is not allowed to shift by either the manual control mode or the automatic control, thereby assuring a speed changing cable to have a suitable tension and preventing falling of chain.

Description

Electric bicycle outside shifting mechanism

The present invention relates to an electric bicycle, and more particularly to a shifting mechanism other than an electric bicycle.

The shifting mechanism of the bicycle can be divided into two types: internal shifting and external shifting. In short, the internal shifting mechanism is hidden inside the rear hub without contact with the outside soil or rainwater, so regular maintenance is not required, but the installation space is limited. The shifting range will also be limited; the external shifting mechanism will directly contact the outside soil or rainwater, so it must be cleaned and maintained regularly, but due to the large external installation space, the shift range will be larger.

In the case of the conventional external shifting mechanism, if the rider performs a forced shifting operation when the large toothed disc stops rotating or the rotational speed is too low, it is easy to make the shifting line appear taut and affect the service life of the shifting line. Moreover, if the rider is stepping on again at this time, the situation of the chain is likely to occur. Therefore, the rider must pay attention to the rotation speed of the large toothed disc during the riding process in order to perform shifting, which is quite inconvenient in operation.

The main object of the present invention is to provide an external electric bicycle shifting mechanism that cannot perform a shifting operation when the rotational speed of the rear wheel, the large toothed disc or the chain is too low, so as to ensure that the shifting line maintains an appropriate tightness, and at the same time Avoid the situation of falling chains.

In order to achieve the above object, the external shifting mechanism of the present invention includes a rear wheel, a crank set, a large toothed disk, a one-way device, a transmission, a chain, and a sensing device. The rear wheel has a rear hub; the crank set has a crank shaft and two cranks, and the two cranks are disposed at two ends of the crank shaft for driving the crank shaft to rotate; the large toothed disc is sleeved on the crank group a crankshaft; the one-way device is disposed between the large toothed disc and the crankshaft, and is coupled to one of the cranks, and is driven by a crank that is assembled with the crankshaft to drive the large toothed disc to perform one-way rotation; The transmission has a shifting sprocket and an electronic derailleur, the shifting sprocket is disposed behind the rear wheel, and the electronic derailleur is disposed on the shifting sprocket for performing a shifting shifting operation; the chain winding The large toothed disc, the shifting sprocket of the transmission, and the electronic derailleur of the transmission enable the rear hub, the large chainring, and the chain to be simultaneously rotatable; the sensing device is electrically connected to the electronic dial a chain device for sensing the rotational speed of the rear wheel, the rotational speed of the large chainring or the rotational speed of the chain. Thereby, when the rotating speed sensed by the sensing device is higher than a set value, the electronic derailleur can smoothly perform a shifting operation, and when the sensing speed sensed by the sensing device is lower than a set value At this time, the electronic derailleur cannot perform the shifting action.

For a detailed description of the structure, features, and advantages of the present invention, a preferred embodiment is illustrated and described in conjunction with the following drawings.

Referring to the first figure, in order to apply the electric bicycle 10 of the first preferred embodiment of the present invention, the electric bicycle 10 shown in the drawing mainly comprises a frame 12 and a front wheel 14 disposed at the front end of the frame 12. Referring to the second to fourth figures, the external shifting mechanism 16 of the first preferred embodiment of the present invention mainly includes a rear wheel 18, a crank set 20, a large toothed disc 30, a one-way device 40, and a transmission. 50. A chain 70, a power generating device 80, a sensing device 90, and a center motor.

The rear wheel 18 is disposed at the rear end of the frame 12 and has a rear hub 182.

The crankset 20 has a crankshaft 22 and two cranks 24. The crankshaft 22 is rotatably disposed in the frame 12. The inner ends of the cranks 24 are fixed to one end of the crankshaft 22, and a pedal is provided at the outer end of each crank 24. 26 installation.

The large chainring 30 is sleeved on the crankshaft 22 of the crankset 20 for providing power transmission.

The one-way device 40 has a ratchet ring 42, a ratchet seat 44, and a plurality of pawls 46, wherein the ratchet ring 42 is coupled to the large chainring 30, the ratchet seat 44 is coupled to the crank 24, and each pawl 46 is located in the ratchet ring 42 and the ratchet seat 44, and one end thereof is pivotally disposed on the ratchet seat 44, and the other end is engaged with the ratchet ring 42, as shown in the fourth and fifth figures, so that the one-way device 40 can be connected thereto. The driving of the crank 24 drives the large toothed disc 30 to rotate in one direction. Once the rotational speed of the large toothed disc 30 is higher than the rotational speed of the two cranks 24, the one-way device 40 releases the transmission between the two.

The transmission 50 has a shifting sprocket 54 and an electronic derailleur 60. The shifting sprocket 54 is disposed at one end of the hub 182 behind the rear wheel 18 for providing different shift positions. The electronic derailleur 60 is disposed on the shifting sprocket. 54 is electrically connected to a microcomputer 62. As shown in the sixth figure, the automatic shifting operation can be performed under the control of the microcomputer 62.

The chain 70 is wound around the large chainring 30, the shifting sprocket 54 of the transmission 50, and the electronic derailleur 60 of the transmission 50 such that the rear wheel 18, the large chainring 30, and the chain 70 are simultaneously rotatable. It is worth mentioning that the shifting mechanism 16 of the present invention can provide a center motor having an output gear for connecting one of the crank shaft 22, the large chain gear 30 or the chain 70.

In the present embodiment, the power generating device 80 has a coil holder 82, a coil 84, a wire 86, and a magnet 88. As shown in the fifth figure, the coil holder 82 is attached to the crank shaft 22 by two bearings 83, so that the crank The shaft 22 is rotatable relative to the coil base 82; the coil 84 is fixed to the inner circumferential surface of the coil base 82; the magnet 88 is fixed to the crank shaft 22 and is rotatable relative to the coil 84 by the crank shaft 22 to rotate around the coil 84, thereby generating The magnetic field changes to cause the coil 84 to generate an induced current; the wire 86 is connected at one end thereof to the coil 84 for transmitting the induced current generated by the coil 84 to a device that requires charging, such as a battery or a headlight.

The sensing device 90 has a mounting seat 92, a Hall sensor 94, and a plurality of magnets 96. In the present embodiment, as shown in the fifth figure, the mounting seat 92 is sleeved on the crank shaft 22; Hall sensing The device 94 is disposed on the mounting base 92 and electrically connected to the microcomputer 62. The magnets 96 are fixed to the side of one of the Hall sensors 94 of the large toothed discs 30, and can be driven by the large toothed discs 30 to sense the sense of the Hall. The detector 94 rotates.

The above is the detailed structure of the shifting mechanism 16 other than the present invention, and the operation process and features of the present invention will be described below.

When the rider presses the two pedals 26 to drive the crankset 20 to rotate, the large-toothed disc 30 starts to rotate by the driving of the one-way device 40, and the rear hub 182 is synchronously rotated by the chain 70, thereby driving The wheel 18 is rotated to allow the electric bicycle 10 to advance smoothly. During the rotation of the large toothed disc 30, the Hall sensor 94 senses the rotational speed of the large toothed disc 30 through the change of the magnetic field generated by the magnets 96, and transmits the sensed rotational speed to the microcomputer 62. When the rotational speed of the large chainring 30 is maintained at more than 20 RPM, the rider can perform automatic shifting in addition to the manual shifting, but also through the setting of the microcomputer 62, but when the Hall sensor 94 is used. When the rotation speed of the large toothed disc 30 is sensed to be lower than 20 RPM, the microcomputer 62 can control the electronic derailleur 60 to perform the shifting operation, and the rider at this time cannot use the manual control or the automatic control by the microcomputer 62. Shifting is performed to ensure that the shift line maintains proper tightness while avoiding chaining.

It must be additionally noted that since the rear wheel 18, the large chainring 30, and the chain 70 are simultaneously rotated, the Hall sensor 94 can be mounted at an appropriate position of the frame 12, and the magnet 96 can be disposed at The rim 184 of the rear wheel 18 or the chain 70, as shown in Figures 7 and 8, can achieve the same effect by allowing the Hall sensor 94 to sense the magnets 96. On the other hand, when the magnet 96 is disposed on the rim 184 or the chain 70 of the rear wheel 18, the coil base 82 and the magnet 88 of the power generating device 80 can be respectively mounted to the crank shaft 22 and the large chainring 30, as shown in FIG. Thereby, the magnet 88 is driven by the large toothed disc 30 to rotate around the coil 84 to generate a magnetic field change, and the electric wire 86 transmits the induced current generated by the coil 84.

In summary, the shifting mechanism of the present invention utilizes the arrangement of the one-way device 40 to allow the rear wheel 18, the large chainring 30, and the chain 70 to be rotated at the same speed, and is further coupled with the sensing device 90. Sensing the rotational speed of the rear wheel 18, the large chainring 30 or the chain 70, once the rotational speed is too low, the electronic derailleur 60 can be controlled to be unable to shift to ensure that the shifting line maintains proper tightness while avoiding The condition of the chain is broken.

The constituent elements of the present invention disclosed in the foregoing embodiments are merely illustrative and are not intended to limit the scope of the present invention. The alternative or variations of other equivalent elements are also covered by the scope of the patent application.

10. . . electric bicycle

12. . . Frame

14. . . Front wheel

16. . . External shifting mechanism

18. . . rear wheel

182. . . Back hub

184. . . Rim

20. . . Crank group

twenty two. . . Crankshaft

twenty four. . . crank

26. . . pedal

30. . . Large chainring

40. . . One-way device

42. . . Ratchet ring

44. . . Ratchet seat

46. . . pawl

50. . . transmission

54. . . Shifting sprocket

60. . . Electronic derailleur

62. . . Microcomputer

70. . . Chain

80. . . Power generation unit

82. . . Coil holder

84. . . Coil

86. . . wire

88. . . magnet

90. . . Sensing device

92. . . Mount

94. . . Hall sensor

96. . . magnet

The first figure is a plan view of a bicycle to which the first preferred embodiment of the present invention is applied.

The second and third figures are plan views of the first preferred embodiment of the present invention.

The fourth figure is a perspective view of a one-way device provided by the first preferred embodiment of the present invention.

Figure 5 is a cross-sectional view showing the combination of the first preferred embodiment of the present invention.

Figure 6 is a block diagram of a first preferred embodiment of the present invention.

7 and 8 are partial enlarged views of a second preferred embodiment of the present invention, mainly showing different mounting positions of the sensing device.

Figure 9 is a plan view showing a second preferred embodiment of the present invention, mainly showing different mounting positions of the power generating device.

16. . . External shifting mechanism

18. . . rear wheel

182. . . Back hub

20. . . Crank group

twenty four. . . crank

26. . . pedal

30. . . Large chainring

60. . . Electronic derailleur

70. . . Chain

86. . . wire

88. . . magnet

92. . . Mount

96. . . magnet

Claims (8)

An electric bicycle external shifting mechanism comprises: a rear wheel having a rear hub; a crank set having a crank shaft and two cranks, the two cranks being disposed at two ends of the crank shaft; a large toothed disc, a sleeve a crank shaft disposed in the crank set; a one-way device disposed between the large toothed disc and the crank shaft of the crank set and coupled to one of the cranks, the large toothed disc being driven by the crank a unidirectional rotation; a transmission having a shifting sprocket and an electronic derailleur, the shifting sprocket being disposed behind the rear wheel, the electronic derailleur being disposed on the shifting sprocket; a chain being wound around The large toothed disc, the shifting sprocket of the transmission, and the electronic derailleur of the transmission enable the rear wheel, the large chainring, and the chain to rotate simultaneously; and a sensing device electrically connected to the electronic dial a chain device for sensing the rotation speed of the rear wheel, the rotation speed of the large toothed disc or the rotation speed of the chain, so that the electronic derailleur can sense the rotation speed of the rear wheel according to the sensing device, the large tooth The speed of the disk or the speed of the chain is changed. Action. The electric bicycle external shifting mechanism according to claim 1, wherein the sensing device has a mounting seat, a Hall sensor, and a plurality of magnets, the mounting seat is sleeved on the crank shaft, and the Hall sensing The device is disposed on the mounting seat, and the magnets are fixed to the large toothed disc, and are driven by the large toothed disc to rotate relative to the Hall sensor. The electric bicycle external shifting mechanism according to claim 1, further comprising a power generating device having a coil base, a coil, a magnet, and a wire, the coil base being coupled to the crank shaft, the coil being fixed to the a coil holder fixed to the crank shaft and rotatable relative to the coil by the crank shaft to rotate relative to the coil, the wire connecting the coil. The electric bicycle external shifting mechanism according to claim 1, wherein the sensing device has a Hall sensor and a plurality of magnets fixed to the chain and respectively corresponding to the Hall sensors. The electric bicycle external shifting mechanism according to claim 1, wherein the sensing device has a Hall sensor and a plurality of magnets fixed to one of the rear wheels and respectively corresponding to the Hall sensor . The electric bicycle external shifting mechanism according to claim 1, further comprising a power generating device having a coil base, a coil, a magnet, and a wire, the coil base being connected to the crank shaft, wherein the coil is disposed on the crankshaft a coil holder, the magnet is disposed on the large toothed disc and opposite to the coil, and is rotatable around the coil by the large toothed disc, and the electric wire is connected to the coil. The electric bicycle external shifting mechanism according to claim 1, further comprising a center motor, wherein the center motor has an output gear for connecting the crank shaft, the large chain gear or one of the chains. The electric bicycle external shifting mechanism according to claim 1, wherein the one-way device comprises a ratchet ring, a ratchet seat, and a plurality of pawls disposed between the ratchet ring and the ratchet seat, the spine The ring gear is connected to the large toothed disc, and the ratchet seat is connected to the crank. One end of each of the pawls is pivoted to the ratchet seat, and the other end is engaged with the ratchet ring.