JPH05319357A - Electric transmission for bicycle - Google Patents

Abstract

PURPOSE:To satisfy the cross directional dimension of a vehicle at a motor mounted part with the dimension for one motor, and make an electric transmission for bicycle compact by positioning each output shaft of a motor for front transmission and a motor for rear transmission on the same flat surface crossing the cross direction of a vehicle. CONSTITUTION:In an electric transmission for changing the speed of the rotation of a crank shaft and for transmitting the changed speed to a rear wheel, which is provided with a built-in type front transmission arranged at a crank shaft part and a built-in type rear transmission arranged at a rear wheel shaft part and a switching control device for switching the front and the rear transmissions to a desired speed, the switching control device is provided with a power unit 33, t6 which the shift position signal corresponding to the speed commanded by a shift switch is input, and the power unit 33 switches the front and the rear transmissions through cables 21, 29. In this case, in the power unit 33, output shafts 41a, 42a of motors 41, 42 for each transmission are positioned on the same flat surface crossing the cross direction of a vehicle, and fitted to a case main body 40b. An electric transmission for bicycle is thereby made thin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle electric transmission in which the drive sources of a front transmission and a rear transmission are motors.

[0002]

2. Description of the Related Art Conventionally, as a bicycle transmission, there is one having a structure in which a transmission is driven by a motor, as disclosed in, for example, Japanese Patent Publication No. 58-57351. In the transmission shown in this publication, a transmission having a structure for changing the winding diameter of a chain is arranged at a hub portion of a rear wheel, and a transmission cable for operating the transmission is connected to a transmission motor.

The transmission motor is housed in a control box together with a battery and mounted on the side of the rear carrier.
The output shaft of the gear shifting motor was oriented in the vehicle width direction and was connected to the gear shift cable pulley via a spur gear. The transmission is configured such that the shift motor mounted on the handle operates the shift motor to shift the transmission.

[0004]

However, in the transmission constructed as described above, the control box accommodating the gear shifting motor projects greatly from the rear carrier toward the side of the vehicle body, which may be an obstacle when maneuvering the vehicle body. There was a problem that it was easy to collide with the next bicycle at a bicycle storage place. In order to eliminate such a problem, the control box may be formed with a narrow width, but since the transmission motor is housed with its axial direction being the same direction as the vehicle width direction,
There was a limit to doing so.

The present invention has been made to solve such a problem, and an object thereof is to reduce the size and thickness of the mounting portion of the transmission motor.

[0006]

SUMMARY OF THE INVENTION An electric transmission for a bicycle according to the present invention comprises a front transmission arranged at a crankshaft portion, a rear transmission arranged at a rear wheel portion, and the front portion. A power unit for driving the transmission and the rear transmission by the front transmission motor and the rear transmission motor, a shift switch for inputting a target shift speed, and a target shift speed input by the shift switch. And a control unit for driving the power unit to control the shift positions of the front transmission and the rear transmission, the output shaft of the front transmission motor and the output shaft of the rear transmission motor. Are positioned on substantially the same plane orthogonal to the vehicle width direction.

[0007]

When mounting the two motors of the front transmission motor and the rear transmission motor, the dimension of the motor mounting portion in the vehicle width direction need only be one motor.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described in detail by. 1 is a side view of a bicycle equipped with an electric transmission according to the present invention, FIG. 2 is a partially cutaway plan view of a front transmission, FIG. 3 is a side view of the same, and FIG.
Is a plan view showing the rear detection device partially broken, FIG. 5 is a plan view showing the whole rear detection device, and FIG. 6 is a side view showing the rear detection device partially broken.

FIG. 7 is a block diagram showing the structure of the electric transmission according to the present invention, FIG. 8 is a plan view of the shift switch, and FIG.
Is a side view showing a state in which the cover of the power unit is removed, FIG. 10 is a sectional view taken along the line XX in FIG. 9, and FIG. 11 is a flowchart for explaining the operation of the electric transmission according to the present invention. The first half of the speed change operation is shown. FIG. 12 is a flowchart showing the latter half of the gear shift operation.

In these drawings, reference numeral 1 denotes a bicycle equipped with the device of this embodiment. This bicycle 1 has a body frame 2
A front fork 4 that rotatably supports the front wheel 3 is pivotally supported on the front part of the vehicle, and a rear fork 6 with a built-in drive shaft that rotatably supports the rear wheel 5 is provided on the rear part of the vehicle body frame 2. In addition, 7 is a saddle and 8 is a steering handle.

Reference numeral 9 denotes an electric transmission for changing the rotation of the crankshaft 10 and transmitting the same to the rear wheels 5, which is an internal front transmission 11 arranged on the crankshaft 10.
And an internal rear transmission 12 arranged on the rear wheel shaft 5a.
And a switching control device 13 for switching the front and rear transmissions 11 and 12 to desired gears.

As shown in FIG. 2 and FIG. 3, the front transmission 11 is disposed in the left and right split type casing 14, and the crankshaft 10 has cranks 10a with foot pedals fixed to both ends thereof. A carrier 15 fixed to the shaft 10, a driven rotating body 16 rotatably mounted on the crank shaft 10, three sets of planetary gears 17 pivotally supported by the carrier 15, and a periphery of the crank shaft 10. Three sets of sun gears 1 arranged to mesh with the planetary gears 17
8 and a switching mechanism 19 for fixing any one of these sun gears 18.

Reference numeral 20 denotes a drive shaft for transmitting the output of the front transmission 11 to a rear transmission 12, which will be described later. The drive shaft 20 is built in the right rear fork 6 and rotated by the rear fork 6. It is supported freely. A bevel gear 20a is fixed to the tip of the drive shaft 20, and the bevel gear 20a meshes with the output gear 16a formed on the outer surface of the driven rotor 16.

Then, the shifting cylinder 19 of the switching mechanism 19
The rear end of the front drive cable 21 is connected to one end of the switching lever 19b that rotates a. The front end of the front drive cable 21 is connected to a power unit of the switching control device 13, which will be described later. Reference numeral 22 denotes an urging spring for urging the switching lever 19b to the initial position counterclockwise in FIG. 3, which is interposed between the switching lever 19b and the fixed bracket 23. At the initial position of the switching lever 19b, the cable holding portion 19c of the switching lever 19b is the stopper 23a of the fixed bracket 23.
It refers to the position in contact with.

At the other end of the switching lever 19b,
A front detection device 24 for detecting the shift position of the front transmission 11 is provided. The front detecting device 24 includes a fan-shaped drive gear 24a that is bolted and fixed to the switching lever 19b, a driven gear 24b that meshes with the drive gear 24a, and a sensor 25 that is fixed to the outer surface of the casing 14. Therefore, the driven gear 24b is fixed to the input shaft of the sensor 25.

The sensor 25 has a structure in which the electric resistance of the internal circuit changes when the rotational position of the input shaft changes. That is, the sensor 25 is the switching lever 1
9b to output a detection signal corresponding to the rotation angle of the switching lever 19b, in other words, the gear shift position of the front transmission 11, from the relationship of being connected to the gear 9b via the speed-increasing gear including the drive gear 24a and the driven gear 24b. become.

The rear transmission 12 is, as shown in FIGS. 4 to 6, a transmission gear train (not shown) housed in the hub of the rear wheel 5 and arranged around the rear wheel shaft 5a. It is composed of a switching mechanism 26 for switching the transmission gear train to a predetermined shift position. In the switching mechanism 26, the switching rod 26a slidably inserted into the rear wheel shaft 5a is provided with a rear wheel shaft 5a.
It is configured to be pushed by the pressing portion 27a of the switching arm 27 against the spring force of the rod urging spring (not shown) therein.

The switching arm 27 is axially supported by a rotary shaft 27b which is planted upward on a support bracket 28 which supports the rear wheel shaft 5a, and the rear end of the rear drive cable 29 is attached to the inner end 27c thereof. Are connected. The front end of the rear drive cable 29 has a switching control device 13 to be described later.
Connected to the power unit.

A rear detection device 30 for detecting the shift position of the rear transmission 12 is disposed near the switching mechanism 26. The rear detection device 30 is composed of a fan-shaped drive gear 30a integrally formed with the switching arm 27, a driven gear 30b meshing with the drive gear 30a, and a sensor 31 fixed to the upper surface of the support bracket 28. The driven gear 30b is fixed to the input shaft of the sensor 31.

The sensor 31 is the same as the sensor 25 mounted on the front transmission 11, and outputs a detection signal corresponding to the rotation angle of the switching arm 27, that is, the shift position of the rear transmission 12. Is configured to.

As shown in FIG. 7, the switching control device 13 includes a shift switch 32 to which a target gear position is input.
And a control unit 34 for outputting a gear shift position signal corresponding to a gear shift position designated by the shift switch 32 to a power unit 33 described later, and the front and rear drive cables 21, 29 according to the gear shift position signal from the control unit 34. And a power supply unit 35 that supplies power to the above-described control device constituent members.

As shown in FIG. 8, the shift switch 32 includes an instruction button 36 for directly instructing any one of the first to twelfth gears, and one gear from the current gear. Up button 3 to switch to high speed side by step
7, a down button 38 for switching to the low speed side one by one, and a display lamp 39 for displaying the current gear position. The shift switch 32 is supported and fixed to the steering handle 8 as shown in FIG.

The power unit 33 is shown in FIG. 9 and FIG.
As shown in FIG. 0, the front transmission motor 4 is provided in the case 40.
1, a rear transmission motor 42 and a front reduction gear mechanism 4 for connecting front and rear drive cables 21, 29 to these motors
3, a rear reduction gear mechanism 44 is housed.
The front transmission motor 41 and the rear transmission motor 42
Are connected to the control unit 34.

The case 40 is composed of a case body 40a formed of a synthetic resin in a substantially box shape, and a synthetic resin cover 40b which is screwed to the case body 40a and closes the opening of the case body 40a. 40a is positioned on the right side of the vehicle body and fixed to the frame 2. A seal material 40c is interposed between the case body 40a and the cover 40b.

As shown in FIG. 1, the mounting position of the case 40 is below the saddle 7 and is located between the top tube 2a of the frame 2 and the seat tube 2b. In addition, the structure for fixing the case 40 to the frame 2 is such that a screw-type fastening band 45 is attached to the upper part of the case and the fastening band 45 is fastened to the top tube 2a, and a substantially U-shaped cross section integrally formed at the rear part of the case. The engaging piece 46 has a structure in which the seat tube 2b is held under pressure.

In this way, the case 40 is attached to the top tube 2
By attaching to the connecting portion between a and the seat tube 2b, even if a frame having a different top tube or seat tube length from the frame 2 of this embodiment is used, the angle formed by both tubes is unchanged. There is no gap between the case 40 and each tube. Moreover, since it is positioned on the relatively upper side, muddy water splashed from the front wheel 3 is not splashed. in addition,
The case 40, which accommodates a motor and the like and is heavy, can be brought close to the center of gravity of the passenger in the state of getting on.

The front transmission motor 41 and the rear transmission motor 42 have their respective output shafts 41a, 42a positioned on the same plane orthogonal to the vehicle width direction, and a case body 40b.
It is screwed to. In the present embodiment, the front transmission motor 41 is positioned below the rear transmission motor 42, and the output shafts 41a, 42a are parallel to each other in the axial direction. The output shafts 41a and 42a are fixed with worms 43a and 44a that form part of the front reduction gear mechanism 43 and the rear reduction gear mechanism 44, respectively.

Front reduction gear mechanism 43, rear reduction gear mechanism 44
Are worm wheels 43b and 44b meshing with the worms 43a and 44a, first spur gears 43c and 44c provided coaxially therewith, and the first spur gears 43c and 4c.
Second spur gears 43d and 44d meshing with 4c, and a third spur gear 43 provided coaxially with the second spur gears 43d and 44d.
e, 44e, and a front transmission pulley 47 and a rear transmission pulley 48 that mesh with the third spur gears 43e, 44e. The front drive cable 21 and the rear drive cable 29 are connected to the rotating ends of the front transmission pulley 47 and the rear transmission pulley 48. The rotation shafts of the gears are rotatably supported by the case body 40a and the cover 40b as shown in FIG.

The front transmission pulley 47 and the rear transmission pulley 48 are formed in the same shape by engraving gears 47a and 48a meshing with the third spur gears 43e and 44e, respectively, and are formed in the same shape. Each of them is rotatably supported by a support shaft 49.

That is, when the front transmission motor 41 and the rear transmission motor 42 are operated, their output shafts 41a,
The rotation of 42a is caused by the front reduction gear mechanism 43 and the rear reduction gear mechanism 4
It is transmitted to the pulleys 47 and 48 through the respective gears of No. 4. Then, by changing the rotation direction of each output shaft 41a, 42a, the swinging direction of the pulleys 47, 48 is changed and the front and rear drive cables 21, 29 are pulled or loosened.

By arranging the front transmission pulley 47 and the rear transmission pulley 48 coaxially in this way, the pulley mounting portion can be made compact. Moreover, the front-rear drive cable 2
Since the take-out portions of Nos. 1 and 29 can be concentrated in one place and the take-out directions of the respective drive cables can be made to be the same direction, the front and rear reduction gear mechanisms 43 and 44 can be arranged as shown in this embodiment. By positioning on the rear side (seat tube 2b side) of the two motors 41, 42,
The front and rear drive cables 21 and 29 can be closely routed to the frame 2. The outer 21a of the front drive cable 21 extends downward from the case 40 along the seat tube 2b as shown in FIG. 1 and is guided to the front transmission 11. The outer 29a of the rear drive cable 29 is the seat tube. It extends from the 2b side to the rear fork 6 on the left side of the vehicle body, then extends rearward on the fork 6 and is guided to the rear transmission 12.

The control unit 34 presets a map in which a combination of shift positions of the front and rear transmissions 11 and 12 is preset in order to realize the shift stage (target shift stage) designated by the shift switch 32 (see FIG. (Not shown) is built in, and is configured to drive the power unit 33 according to the target shift speed. The sensor 25 of the front transmission 11 and the sensor 31 of the rear transmission 12 are connected to the control unit 34. The control unit 34 is housed in the case 40 together with the power unit 33. The position where the control unit is mounted in the case 40 is shown by a chain double-dashed line A in FIG.

The power supply unit 35 has a battery (not shown) built in a case, and is supported and fixed to the upper rear portion of the seat tube 2b as shown in FIG.
The power supply unit 35 is provided with a standby power supply switch 35a that cuts off power supply to each part when the electric transmission 9 is not used. When the standby power switch 35a is turned on, the electric transmission 9 can be used.

Next, the operation of the electric transmission 9 configured as described above will be described in detail with reference to the flowcharts shown in FIGS. 11 and 12.

To use the electric transmission 9, first, in step P ₁ , the standby power switch 35a of the power supply unit 35 is turned on. As a result, a weak current flows, and the electric transmission 9 is in a standby state waiting for a shift command. In this state, the button 36 of the shift switch 32,
Pressing in step P ₂ to one of 37, 38, the control unit 3 as shown in Step P ₃
A main circuit (not shown) in 4 is turned on. The control unit 34 stores the button pressed in step P ₂ in the internal memory until the shift switch 32 is newly operated.

Next, in step P ₄ , the control unit 34 determines whether the button pressed by the shift switch 32 is the up button 37, the down button 38, or the instruction button 36. Up button 37
If it is the down button 38 or the button 38, the process proceeds to step P ₅ . In the case of the instruction button 36, it is confirmed which one of the 1st to 12th gears is pressed, and the gear designated by the indication button 36 is set as the command gear (target gear). The process proceeds to step P ₁₁ described later.

Then, the control unit 34 fetches the front transmission position signal output from the sensor 25 in step P ₅ , and then fetches the rear transmission position signal output from the sensor 31 in step P ₆ , P ₇
At, the current shift speed is obtained from the map.

Thereafter, the control unit 34 determines in step P ₈ whether or not the up switch 37 is pushed by the shift switch 32. If it is determined that the up switch 37 has been pressed, step P ₉
At a number obtained by adding 1 to the current gear is stored as a command gear position (target gear position), when it is determined that the up switch 37 down switch 38 rather than the current speed step P ₁₀ The number of gears obtained by subtracting 1 from the gear is stored as the command gear.

In the next step P ₁₁ , the above step P
Obtaining _9, and designated gear position stored in the P _10, the target gear position of the front transmission 11 and rear transmission 12, such as selected gear is obtained when it is judged as NO in step P ₄ from the map .. Then control unit 3
In step P ₁₂ , the current gear position of the front transmission 11 is detected from the output of the sensor 25, and in step ₁₃ , the current gear position of the rear transmission 12 is detected from the output of the sensor 31.

[0040] After detecting the shift position of the thus both transmissions, determines the front transmission for motor 41 of the power unit 33, the rotational direction of the rear transmission for a motor 42 in step P _14. As for the rotation direction of this motor, both transmissions 11,
12 is set in a direction from the current gear shift position to the target gear shift position. Then, in step P ₁₅ , the front gear shifting motor 41 is rotationally driven in the target direction, and in step P ₁₆ , the rear gear shifting motor 42 is also rotationally driven in the target direction. At this time, the front transmission pulley 47 and the rear transmission pulley 48 connected to the both motors 41 and 42 rotate, and the front drive cable 21 and the rear drive cable 29 are pulled or loosened. The front transmission 11 and the rear transmission 12 are shifted.

After operating the motors 41 and 42 as described above, in step P ₁₇ , the gear position of the front transmission 11 detected by the front transmission position signal from the sensor 25 is the target gear position. check whether a, the motor 41 is stopped by a stop command is outputted to the front transmission for motor 41 at step P ₁₈ If it is judged to the target gear position, it has reached the target speed position rear transmission 12 to determine whether or not reached the target gear position proceeds to step P ₁₉ in the absence. Also at this time, the shift position of the rear transmission 12 detected by the rear transmission position signal from the sensor 31 is compared with the target shift position.

When the rear transmission 12 has reached the target shift position, a stop command is output to the rear transmission motor 42 in step P ₂₀ to stop the motor 42. If the target position has not been reached, the next step is carried out. proceed to the P _21. In step P ₂₁ the stop command both motors 41 and 42 to check whether the output. When the both motors 41 and 42 are output stop command is stopped to display the current gear to the indicator 39 of the shift switch 32 in step P _22, when not output the stop command (before by the time section transmission 11 or the rear transmission 12 has not reached the target speed position), the flow proceeds to step P _23.

[0043] Step P _23, the step P3 main power is counting the elapsed time from the turned in, Step P ₄ even until passage of a predetermined time not be operated until the step P ₂₂ It is a determination flow in which the above-described shift operation is repeated by returning to. That is, the crank 10a
Since the front and rear transmissions 11 and 12 are difficult to shift when pedaling, the front and rear transmissions 11 and 12 did not shift to the target shift position in step P ₁₅ or step P ₁₆ . Even in this case, the gear shifting operation is repeated by repeating the above-described gear shifting operation until a certain time has elapsed.

[0044] Then, after a predetermined time has elapsed in step P _23, a shift switch 3 main circuit of the control unit 34 as shown in step P ₂₄ is turned off
Waiting for input from 2. When the power supply is automatically cut off in this way, the power consumption of the power supply unit 35 can be suppressed, and the motors 41 and 42 can be protected when the motors 41 and 42 are stopped due to overload. You can

Therefore, when the output shaft 41a of the front transmission motor 41 and the output shaft 42a of the rear transmission motor 42 are positioned on the same plane orthogonal to the vehicle width direction as shown in this embodiment, When the two motors, the front transmission motor 41 and the rear transmission motor 42, are mounted, the dimension of the motor mounting portion in the vehicle width direction can be the size of one motor.

Further, in this embodiment, the shift switch 32
Both front and rear transmissions 11 and 12 according to the target gear position designated by
Since it is possible to shift gears, it is possible to immediately realize the shift speed instructed by the occupant, and it is possible to easily and surely shift gears even for a beginner or even if the number of shift speeds increases.

In this embodiment, the output shafts of the two motors (the front transmission motor 41 and the rear transmission motor 42) are positioned on the same plane, but the output shafts of both motors are It does not have to be strictly positioned on the same plane, and can be slightly shifted in the vehicle width direction.

Further, in detecting the shift positions of the front and rear transmissions 11 and 12, the sensors 25 and 31 rotate the front transmission pulley 47 and the rear transmission pulley 48 in the drive unit 33. It may be configured to detect the position. As shown in this embodiment, the switching lever 1 is used to detect the shift positions of the front and rear transmissions 11 and 12.
9b, if the structure is such that the rotation angle of the switching arm 27 is detected, the detection accuracy can be improved because it is not affected by the expansion of the front and rear drive cables 21 and 29. That is, as compared with the conventional device in which the shift position is known by the rotation angle of the shift lever located at the front end of the drive cable, the detected shift position does not have an error due to the extension of the drive cable.

[0049]

As described above, the electric transmission for a bicycle according to the present invention has a front transmission disposed on the crankshaft portion, a rear transmission disposed on the rear wheel portion, and the front transmission. Power unit for driving the partial transmission and the rear transmission by the front transmission motor and the rear transmission motor, the shift switch for inputting the target shift speed, and the target shift speed input to the shift switch. And a control unit for driving the power unit in response to the control unit to control the shift positions of the front transmission and the rear transmission, the output shaft of the front transmission motor and the output shaft of the rear transmission motor. Are positioned on substantially the same plane orthogonal to the vehicle width direction. Therefore, when mounting the two motors of the front transmission motor and the rear transmission motor, the dimension of the motor mounting portion in the vehicle width direction is 1 So it requires only minute dimensions.

Therefore, since the dimension of the motor mounting portion in the vehicle width direction can be set to the minimum required dimension, the motor mounting portion can be made compact and thin.

[Brief description of drawings]

FIG. 1 is a side view of a bicycle equipped with an electric transmission according to the present invention.

FIG. 2 is a plan view showing a front transmission partially broken away.

FIG. 3 is a side view showing the front transmission in a partially broken manner.

FIG. 4 is a plan view showing the rear detection device partially broken away.

FIG. 5 is a plan view showing the entire rear detection device.

FIG. 6 is a side view showing the rear detection device partially broken away.

FIG. 7 is a block diagram showing a configuration of an electric transmission according to the present invention.

FIG. 8 is a plan view of a shift switch.

FIG. 9 is a side view showing a state in which a cover of the power unit is removed.

10 is a cross-sectional view taken along line XX in FIG.

FIG. 11 is a flowchart for explaining the operation of the electric transmission according to the present invention, in which the first half of the gear changing operation is shown.

FIG. 12 is a flowchart for explaining the operation of the electric transmission according to the present invention, in which the latter half of the gear changing operation is shown.

[Explanation of symbols]

 9 Electric transmission device 10 Crankshaft 11 Front transmission 12 Rear transmission 13 Switching control device 24 Front detection device 30 Rear detection device 32 Shift switch 33 Power unit 34 Control unit 40 Case 41 Front transmission motor 41a Output shaft 42 Rear Transmission Motor 42a Output Shaft

Claims (1)

[Claims] 1. A front transmission disposed on a crankshaft portion, a rear transmission disposed on a rear wheel portion, the front transmission and the rear transmission including a front transmission motor and a rear portion. A power unit driven by a transmission motor, a shift switch to which a target shift speed is input, and the power unit that is driven according to the target shift speed input to this shift switch to drive the front transmission and the rear shift. A front transmission motor output shaft and a rear transmission motor output shaft are positioned on substantially the same plane orthogonal to the vehicle width direction. An electric transmission for a bicycle, which is characterized in that