JP2001010581A - Automatic transmission device of bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a smooth and stable speed reducing operation by performing the speed reducing operation according to the timing of reducing the pedaling force. SOLUTION: In a shift change that is performed by pressing a shift rod 14a by the movement of a slider 17 by the actuator motor 15 of a shift mechanism 12, the present shift position is detected by the position detection of the slider 17 by the magnetic force detecting reed switch 23 of a magnet 22. When it is judged by the comparison in a controller that the shift operation is necessary because the optimum shift position is differed from the present shift position, the speed reducing operation is waited until the pedaling force value is a prescribed value or less, and when it reaches the prescribed value or lower, the slider 17 is moved by the rotation of an output shaft 16 by the actuator motor 15 driven by the receipt of a shift change instruction, and the speed reducing operation by the pressing of a shift rod 14a is performed according to the timing of reducing the pedaling force, whereby the speed changing operation can be smoothly and stably performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle automatic transmission.

[0002]

2. Description of the Related Art An automatic transmission provided in a bicycle detects the speed of the bicycle and the pedaling force of an occupant, selects an optimum shift position in accordance with the detected speed and the pedaling force, and performs automatic transmission. 2. Description of the Related Art A type of automatic transmission is configured by combining, for example, a parallel gear and a ratchet, and performs speed change by sequentially raising the ratchet when increasing speed.

[0003]

However, in the conventional automatic transmission having the above structure, if a driving force of a certain value or more is present at the time of deceleration, a load acts on the ratchet, so that the ratchet cannot be stored, and the speed is reduced. There was a problem that the operation could not be performed smoothly. In particular, in the case of an electric assist bicycle that travels by receiving auxiliary power from an electric motor, the load is constantly applied to the ratchet because the auxiliary power is applied as it is during traveling, making it more difficult to smoothly perform the deceleration operation. .

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide an automatic transmission for a bicycle that can perform a smooth deceleration operation stably.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention according to claim 1 detects speed and treading force, and selects an optimum shift position according to the detected speed and treading force. The automatic transmission for a bicycle according to the present invention is characterized in that the deceleration operation is performed in accordance with the timing at which the pedaling force decreases.

According to a second aspect of the present invention, there is provided an apparatus provided for a bicycle that travels by receiving auxiliary power from an electric motor, and detects a speed and a pedaling force, and determines an optimal shift position according to the detected speed and the pedaling force. In the automatic transmission for a bicycle which automatically shifts the speed by selecting, the auxiliary power of the electric motor is reduced or stopped according to the timing of the deceleration operation.

Therefore, according to the present invention, the deceleration operation is performed in accordance with the timing at which the pedaling force is reduced, or the auxiliary power of the electric motor is reduced or stopped in accordance with the timing of the deceleration operation. The load acting on the device is kept small, and a smooth deceleration operation can be performed stably.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a side view of a rear part of an electric assist bicycle showing a system configuration of an automatic transmission according to the present invention, and FIG. 2 is a configuration diagram of a shift mechanism of the automatic transmission.

In FIG. 1, reference numeral 1 denotes a power unit mounted on an electric assisted bicycle, 2 denotes a rear wheel which is a driving wheel, 3 denotes a crankshaft, and cranks 4 are attached to both ends of the crankshaft 3. The pedals 5 are respectively supported at the ends of the pedals.

A large-diameter sprocket 6 is mounted on an output shaft (combined shaft) (not shown) of the power unit 1, and a small-diameter sprocket 8 is mounted on the rear axle 7. Is wound with an endless chain 9.

The power unit 1 includes an electric motor 10 driven by the supply of a current from a battery (not shown) and a pedal force detection unit (not shown) for detecting a pedal force of an occupant input from the pedal 5 to the crankshaft 3. And speed detecting means (not shown) for detecting the running speed of the bicycle from the rotational speed of the crankshaft 3 and the shift position.

The automatic transmission according to the present invention includes a shift mechanism 12 provided on the rear axle 7 and a controller 13.
The details of the configuration of the shift mechanism 12 are shown in FIG.

That is, in FIG. 2, reference numeral 14 denotes a shift change device including a shift rod 14a, 15 denotes an actuator motor, and an output shaft 16 of the actuator motor 15 forms a screw shaft. A slider 17 is screwed to the output shaft 16 of the actuator motor 15 so as to be movable in the direction of the arrow shown in the figure. A bracket 18 attached to the slider 17 has an elongated hole 18a formed therein. Is connected to one end of a bell crank 19 by a pin 20.

The bell crank 19 has a shaft 2 at its intermediate portion.
1 and is rotatably mounted on the bell crank 19.
Is in contact with an end of a shift rod 14a of the shift change device 14 as shown in the figure.

A magnet 22 is provided on the slider 17.
In the vicinity of the magnet 22, two detection reed switches 23 are juxtaposed in the moving direction of the slider 17. These detection reed switches 23 are connected to the controller 13.

When the occupant steps on the left and right pedals 5 alternately in the electric assisted bicycle according to the present embodiment, the occupant's treading force input to the crankshaft 3 is applied to the power unit 1 (not shown). It is detected by the detecting means, and this detection signal is output to the controller 13. Then, since the controller 13 outputs a current corresponding to the detected treading force to the electric motor 10 of the power unit 1, the electric motor 10 generates auxiliary power according to the treading force, and the resultant force of the auxiliary power and the treading force is the power unit 1. Are output to an output shaft (combined shaft) (not shown), and the rotation of the output shaft (combined shaft)
Is transmitted to the rear axle 7, and the rear axle 7 and the rear wheel 2 are integrally rotated and driven, and the electric assisted bicycle runs.
Since a part of the driving force is borne by the auxiliary power of the electric motor 10, the physical burden on the occupant is reduced.

The electric assisted bicycle according to the present embodiment is provided with the automatic transmission according to the present invention.
The electric assist bicycle is automatically shifted by the automatic transmission according to the speed and the pedaling force. Hereinafter, the procedure will be described based on the flowchart shown in FIG.

While the electric assisted bicycle is running, the speed detected by the speed detecting means (not shown) provided in the power unit 1 and the pedaling force detected by the pedaling force detecting means are input to the controller 13, and the controller 13 detects the speed. An optimum shift position is calculated according to the speed and the pedaling force (step S1).

When the output shaft 16 of the shift mechanism 12 is driven by driving the actuator motor 15 of the shift mechanism 12, the slider 17 screwed to the output shaft 16 reciprocates in the direction of the arrow in FIG. The movement causes the bell crank 19 to rotate about the shaft 21 in the direction of the arrow in FIG. 2 and press the shift rod 14 a of the shift change device 14 to perform a required shift change.
The current shift position is detected by detecting the position of the slider 17 by the detection reed switch 23 for detecting the magnetic force of the magnet 22 fixed to the controller 22, and this detection signal is input to the controller 13.

When the controller 13 calculates the optimum shift position as described above (step S1),
The controller 13 determines whether the optimal shift position is the same as the current shift position (step S2). If the optimal shift position is the same, the controller 13 calculates the optimal shift position again (step S1). It is determined whether the shift operation is a deceleration operation (step S3).

Here, the shift change device 14 used in the present embodiment is configured by combining a parallel gear and a ratchet, and the speed is increased by sequentially raising the ratchet during speed-up, so that the speed-up operation is always smooth. On the other hand, when a driving force of a certain value or more is present at the time of deceleration, a load acts on the ratchet, so that the ratchet is not stored, and the deceleration operation cannot be performed smoothly.

In this embodiment, when the shift operation is necessary because the optimum shift position is different from the current shift position, if the shift operation is a deceleration operation, the pedaling force value is reduced. The controller 13 waits until the pedaling force falls below a certain value (step S4). When the pedaling force falls below a certain value, the controller 13 sends a shift change instruction signal corresponding to the calculated optimal shift position to the shift mechanism 1.
Then, the data is transmitted to the second actuator motor 15 to drive the actuator motor 15 (step S5). Then
As described above, the output shaft 16 of the actuator motor 15 is driven to rotate, and the slider 17 moves.
7, the bell crank 19 rotates about the shaft 21 and the shift rod 14 of the shift change device 14
A desired deceleration operation is performed because a is pressed. In this case, the deceleration operation is performed in accordance with the timing at which the pedaling force decreases, so that a smooth deceleration operation is stably performed.

On the other hand, if the shift operation is necessary because the optimum shift position is different from the current shift position, and the shift operation is a speed-up operation, the speed-up operation is always smooth as described above. Therefore, the controller 13 transmits a shift change instruction signal corresponding to the optimum shift position to the actuator motor 15 of the shift mechanism 12 irrespective of the pedaling force value, and drives the actuator motor 15 to perform a desired speed-up operation. (Step S5).

Although the present embodiment has been described with respect to an example in which the present invention is applied to an automatic transmission mounted on an electric assist bicycle, the present invention is similarly applied to an automatic transmission mounted on a normal bicycle. Can be applied to

Second Embodiment Next, a second embodiment of the present invention will be described.

It should be noted that the automatic transmission according to the present embodiment is also mounted on a battery-assisted bicycle as in the first embodiment.
Since the configuration is also the same as that shown in the first embodiment, illustration and description thereof are omitted, and the following description uses the reference numerals shown in FIGS.

This embodiment is characterized in that the auxiliary power of the electric motor 10 of the power unit 1 is reduced or stopped according to the timing of the deceleration operation. Less than,
The procedure will be described based on the flowchart shown in FIG.

While the electric assisted bicycle is traveling, the speed detected by the speed detecting means (not shown) provided in the power unit 1 and the treading force detected by the treading force detecting means are input to the controller 13, and the controller 13 detects the speed. An optimum shift position is calculated according to the speed and the pedaling force (step S11), and it is determined whether the optimum shift position is the same as the current shift position (step S12). If the optimum shift position is the same as the current shift position, the optimum shift position is calculated again (step S11), and if different, it is determined whether the shift operation is a deceleration operation (step S13).

When a shift operation is necessary because the optimum shift position is different from the current shift position, and if the shift operation is a deceleration operation, the current supplied to the motor 10 of the power unit 1 is reduced. The auxiliary power is reduced or set to 0 by reducing or stopping the supply of current (step S14), and a shift change instruction signal corresponding to the optimum shift position is transmitted to the actuator motor 15 of the shift mechanism 12 in this state. The actuator motor 15 is driven (Step S15). Accordingly, in this state, the load acting on the shift mechanism 12 during the deceleration operation is kept small, and a smooth deceleration operation can be stably performed as in the first embodiment.

During the shift operation, the current shift position is detected (step S16), and it is determined whether or not the current shift position matches the optimum shift position (step S17). Until they match (steps S15 to S1
7) When both shift positions match, the current supplied to the electric motor 10 is returned to a normal value (step S18).

On the other hand, if the shift operation is necessary because the optimum shift position is different from the current shift position, and the shift operation is a speed-up operation, the speed-up operation is always smoothly performed as described above. Therefore, a shift change instruction signal corresponding to the optimum shift position is transmitted to the actuator motor 15 of the shift mechanism 12 without changing the supply current to the electric motor 10 and the actuator motor 15 is driven to increase the desired amount. A speed operation is performed (step S15).

[0033]

As is apparent from the above description, according to the present invention, the deceleration operation is performed in accordance with the timing at which the pedaling force decreases, or the auxiliary power of the motor is reduced or stopped in accordance with the timing of the deceleration operation. As a result, the load acting on the automatic transmission during the deceleration operation is suppressed to be small, and an effect is obtained that a smooth deceleration operation can be performed stably.

[Brief description of the drawings]

FIG. 1 is a side view of a rear part of an electric assist bicycle showing a system configuration of an automatic transmission according to the present invention.

FIG. 2 is a configuration diagram of a shift mechanism of the automatic transmission according to the present invention.

FIG. 3 is a flowchart showing a shift operation procedure of the automatic transmission according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing a shift operation procedure of the automatic transmission according to Embodiment 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power unit 10 Electric motor 12 Shift mechanism 13 Controller 14 Shift change device 15 Actuator motor 17 Slider 19 Bell crank 22 Magnet 23 Reed switch for detection

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroshi Nagai 2500 Shinkai, Iwata-shi, Shizuoka F-term in Yamaha Motor Co., Ltd. (reference) 3J050 AA08 BA13 BB04 CE07 CE09 DA04

Claims (2)

[Claims] An automatic transmission for a bicycle that detects a speed and a treading force, selects an optimal shift position according to the detected speed and a treading force, and performs automatic shifting, performs a deceleration operation in accordance with a timing at which the treading force decreases. An automatic transmission for a bicycle, characterized in that the transmission is performed. 2. A device provided on a bicycle that travels by receiving auxiliary power from an electric motor, detects speed and treading force, and selects an optimal shift position according to the detected speed and treading force to automatically shift. An automatic transmission for a bicycle, comprising: reducing or stopping the auxiliary power of the electric motor in accordance with the timing of a deceleration operation.