TWI728558B - Bicycle shifting system - Google Patents

Abstract

A bicycle shifting system mounted on a bicycle, the bicycle having a vehicle body, a steering handle pivoted on a front side of the vehicle body, a pedaling mechanism pivoted on the vehicle body, and a shifting mechanism disposed on the vehicle body, The bicycle shifting system includes a sensing device, an electronic shifting device, and a shifting indicating device. The sensing device is disposed on the pedaling mechanism for detecting the torque and the frequency of the pedaling mechanism. The electronic shifting device is disposed on the vehicle body and can interlock the shifting mechanism and is electrically connected to the sensing device. The shift indicating device is disposed on the steering handle and electrically connected to the electronic shifting device. The shifting indicating device sends a shifting command to the electronic shifting device, and the electronic shifting device interlocks the shifting mechanism for shifting at an optimal shifting timing according to the information detected by the sensing device.

Description

Bicycle transmission system

The invention relates to a bicycle gear shifting device, in particular to a bicycle gear shifting system and a method for judging the best gear shifting timing of a bicycle.

Bicycle transmission mechanism can be divided into two types: internal transmission and external transmission. In simple terms, the internal transmission mechanism is hidden inside the rear hub and will not be in contact with external soil or rain, so it does not require regular maintenance, but due to limited installation space , The transmission range will also be limited; the external transmission mechanism is in direct contact with external soil or rain, so it must be cleaned and maintained regularly. However, due to the large external installation space, the transmission range will also be relatively large.

As far as the existing external transmission mechanism is concerned, if the rider performs a forced shift action when the large chainring stops rotating or the speed is too low, it is easy to make the transmission line tight and affect the service life of the transmission line. Moreover, if the rider pedals again at this time, it is easy to fall off the chain. Therefore, the rider must pay attention to the rotation speed of the large chainring to shift gears during riding, which is quite inconvenient in operation.

Therefore, the object of the present invention is to provide a bicycle transmission system that can shift gears at the best timing.

The bicycle transmission system of the present invention is installed on a bicycle. The bicycle has a body, a steering handle pivoted on the front side of the body, a pedaling mechanism pivoted on the body, and a shift mechanism provided on the body , The bicycle shifting system includes a sensing device, an electronic shifting device, and a shifting indicating device. The sensing device is arranged on the pedaling mechanism to detect the pedaling torque and pedaling frequency of the pedaling mechanism. The electronic speed change device is arranged on the vehicle body and can link the speed change mechanism and is electrically connected to the sensing device. The speed change indication device is arranged on the steering handle and is electrically connected to the electronic speed change device. The shift indicating device will send a shift command to the electronic shifting device, and the electronic shifting device will link the shifting mechanism to shift gears at an optimal shift timing based on the information detected by the sensing device.

Another technical means of the present invention is that the electronic transmission device applies the information detected by the sensing device to the exponential smoothing method, and predicts the maximum torque occurrence time as the best shift timing. When the electronic transmission device receives After the shift command is reached, the shift mechanism will be linked to shift gears at the optimal shift timing.

Another technical means of the present invention is that the electronic transmission device includes a control chip, a servo motor electrically connected to the control chip, and a first swing arm and a second swing arm respectively linked by the servo motor. The transmission mechanism of the bicycle includes a front transmission, a rear transmission, and a front transmission cable and a rear transmission cable that control the front transmission and the rear transmission respectively. The first swing arm and the second swing arm are controlled separately The tightness of the front gear cable and the rear gear cable.

Another technical means of the present invention is that the shift indicating device includes an upshift button and a downshift button.

Another technical means of the present invention is that the gear shift indicating device further includes a gear display.

Another technical means of the present invention is that the sensing device includes a torque sensor arranged on the pedaling mechanism, and a cadence sensor arranged on the pedaling mechanism.

Another object of the present invention is to provide a method for judging the best shift timing of a bicycle.

The method for judging the optimal shift timing of a bicycle of the present invention includes an initial step, a detecting step, a predicting step, and a shifting step. The initial step is that the speed indication device sends a speed change command, the detection step is that the sensing device detects the pedaling torque and pedaling frequency of the pedaling mechanism, and the predicting step is that the electronic speed change device detects according to the sensing device The information obtained can predict the best gear shift timing. In the shift step, the electronic transmission device links the transmission mechanism to shift gears at the optimal shift timing.

Another technical means of the present invention is that in the predicting step, the optimal shift timing is the predictive timing of the maximum torque.

Another technical means of the present invention is that in the predicting step, the electronic transmission device applies the information detected by the sensing device to an exponential smoothing method to predict the occurrence time of the maximum torque.

The effect of the present invention is that through the above-mentioned structure and method, improper operation of the user on the gear shift can be effectively avoided, and the risk of incorrect gear shifting can be reduced.

The features and technical content of the related patent applications of the present invention will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. Before detailed description, it should be noted that similar components are denoted by the same numbers.

1 and 2, a preferred embodiment of the bicycle transmission system of the present invention is installed on a bicycle. The bicycle has a body 11, a steering handle 12 pivoted on the front side of the body 11, and a steering handle 12 pivoted on the front side of the body 11. A pedaling mechanism 13 on the body 11 and a speed change mechanism 14 provided on the body 11, the bicycle speed change system includes a sensing device 2, an electronic speed change device 3, and a speed change indication device 4.

The sensing device 2 is arranged on the pedaling mechanism 13 to detect the pedaling torque and pedaling frequency of the pedaling mechanism 13. The sensing device 2 includes a torque sensor 21 and a cadence sensor 22. In this embodiment, a resistive torque sensor 21 is used and installed in the central axis of the pedaling mechanism 13, and a double crank (double pedaling force) sensing function is provided. When the pedaling torque is greater, the measured The higher the voltage of, the data can be obtained by analog-to-digital converter. In addition, the cadence sensor 22 can be installed in the central shaft of the pedaling mechanism 13, or on the pedal or crankshaft of the pedaling mechanism 13, as long as it is a position where the user's pedaling frequency can be detected. The cadence sensor 22 uses infrared rays to sense the pedaling frequency. When the pedaling mechanism 13 rotates once, the cadence sensor 22 will receive ten pulse signals. When the pedaling mechanism 13 is not rotating, No signal.

Referring to FIGS. 2 and 3, the electronic transmission device 3 is arranged on the vehicle body 11 and can interlock with the transmission mechanism 14 and is electrically connected to the sensing device 2. The electronic transmission device 3 includes a control chip 31, a servo motor 32 electrically connected to the control chip 31, and a first swing arm 33 and a second swing arm 34 respectively linked by the servo motor 32. It should be noted that, in this embodiment, the bicycle transmission mechanism 14 is an external transmission type as an example, and includes a front transmission 141, a rear transmission 142, and control the front transmission 141 and the rear transmission 142 respectively. A front shift cable 143 and a rear shift cable 144. The first swing arm 33 and the second swing arm 34 of the electronic transmission device 3 respectively control the tightness of the front shift cable 143 and the rear shift cable 144 of the bicycle.

2 and 4, the shift indicating device 4 is arranged on the steering handle 12 and electrically connected to the electronic shift device 3, and includes an upshift button 41, a downshift button 42, and a gear display 43 .

It should be particularly noted here that after testing the torque sensor 21, it is found that when the two feet exert an average force, the maximum torque appears in sequence, and it drops rapidly immediately after the maximum torque value. At the same time, refer to Figure 5. Figure 5 (a) shows the torque distribution of each pedaling point. The size of the circle corresponding to each pedaling position in the figure represents the torque. It can be seen that the pedaling position shown in Figure 5 (b) corresponds to The torque of is approaching the maximum value, which is the best gear shifting point, and the pedaling position shown in Figure 5(c) corresponds to the torque will become smaller and smaller, which is the worst gearing point. This embodiment uses the exponential smoothing method based on the aforementioned torque characteristics. By reading the continuous signal of the torsion force, it can use a small amount of sample data and does not discard the past data, but only gives the characteristics of gradually weakening the degree of influence, which can be predicted. A piece of future data is used to predict the point of occurrence of the maximum torque value, and shift gears at the point of occurrence of the maximum torque value in advance to increase riding smoothness.

Referring to FIG. 6, in this embodiment, the front transmission 141 has three large gears, A1 to A3, and the rear transmission 142 has eight flywheels, B1 to B8, respectively. The large gear and the flywheel are driven by a chain. Among them, the combination of the large gear and the flywheel shown in Figure 6 will cause excessive bending of the chain, causing improper wear of the chain, large gear, and flywheel, which is an unreasonable gear. The combination of large gear and flywheel as shown in Figure 7 is a reasonable gear.

In addition, as shown in the relationship between the gear position and gear ratio in the following table, the current transmission 141 is 2 gears, the rear transmission 142 is 2 gears (gear ratio 1.07:1), and the next gear is the front transmission 141 with 3 gears and rear The transmission 142 has 5 speeds (gear ratio 1.10:1). In other words, the relationship between the front derailleur 141 and the rear derailleur 142 is not linear but abrupt, and there will be repeated gear ratios. Gear ratio After 1 After 2 After 3 After 4 After 5 After 6 After 7 After 8 First 1 1.29 1.47 1.69 1.91 2.20 2.59 2.93 3.38 First 2 0.94 1.07 1.23 1.39 1.60 1.88 2.13 2.46 Top 3 0.65 0.73 0.85 0.96 1.10 1.29 1.47 1.69

Therefore, the control chip 31 of the electronic transmission 3 is pre-written with an exponential smoothing method. By reading the continuous signal of the torque detected by the torque sensor 21, the point of occurrence of the maximum torque value is predicted, and whether it is the maximum value is judged. Optimal variable speed pedal position is also written into the algorithm to avoid the aforementioned unreasonable and repeated gear positions.

Next, a preferred embodiment of the method for determining the optimal shift time for a bicycle of the present invention will be described, which includes an initial step, a detection step, a prediction step, and a shift step.

2 and 4, in the initial step, the shift instruction device 4 sends a shift command, that is, the user presses the upshift button 41 or the downshift button 42 through the shift instruction device 4, and in the gear It is displayed on the position indicator 43 to let the user know the current gear position.

Then, in the detection step, the sensing device 2 detects the pedaling torque and pedaling frequency of the pedaling mechanism 13 and feeds the signal back to the control chip 31 of the electronic transmission device 3. In the predicting step, the electronic transmission device 3 predicts the best shifting stepping point position based on the pedaling torque and the pedaling frequency detected by the sensing device 2, that is, the best shifting timing. In this embodiment, it is predicted that the point of occurrence of the maximum torque value is the best shift timing.

Finally, in the shifting step, the control chip 31 will drive the servo motor 32 at the best shift timing to adjust the swing angles of the first swing arm 33 and the second swing arm 34, and change the front speed change cable 143 and The tightness of the rear transmission cable 144 is used to adjust the relationship between the front transmission 141 and the rear transmission 142, thereby achieving the effect of adjusting the gear position. As shown in Figures 8 and 9, when the servo motor 32 adjusts the first swing arm 33 and the second swing arm 34 to move between different swing angles, the front speed change cable 143 and the rear The tightness of the speed change cable 144 is changed, and a shift operation can be performed.

To sum up, the bicycle transmission system of the present invention uses the control chip 31 as the system control core, and uses the data of the sensing device 2 to determine the pedaling torque and pedaling frequency. When a gear shift is required, the electronic transmission device 3 controls the bicycle. The original speed change mechanism 14 and the algorithm in the control chip 31 can achieve the effect of shifting gears at the time of maximum pedaling torque and avoiding unreasonable gear positions, which can indeed achieve the purpose of the invention.

However, the above are only the preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the description of the invention, All are still within the scope of the invention patent.

11: Body 12: steering handle 13: trampling mechanism 14: Transmission mechanism 141: front derailleur 142: rear derailleur 143: Front gear cable 144: Rear gear cable 15: chain 2: Sensing device 21: Torque sensor 22: Cadence Sensor 3: Electronic transmission device 31: control chip 32: Servo motor 33: First swing arm 34: second swing arm 4: Variable speed indicating device 41: Upshift button 42: Downshift button 43: gear display

Fig. 1 is a schematic diagram showing a preferred embodiment of the bicycle transmission system of the present invention; Figure 2 is a system architecture diagram illustrating the composition of the preferred embodiment; Figure 3 is a partial schematic side view illustrating the structure of an electronic transmission device in the preferred embodiment; Figure 4 is a schematic diagram illustrating the structure of a speed indicator device in the preferred embodiment; Figure 5 is a schematic diagram illustrating the magnitude of the torque at each pedaling point, the best shifting pedaling point, and the worst shifting pedaling point in the preferred embodiment; Figure 6 is a schematic diagram illustrating the unreasonable gear matching of the front derailleur and the rear derailleur in the preferred embodiment; Figure 7 is a schematic diagram illustrating the reasonable gear matching of the front derailleur and the rear derailleur in the preferred embodiment; and Fig. 8 and Fig. 9 are partial schematic side views, illustrating the electronic gear shifting device in different gear shifting states.

14: Transmission mechanism

143: Front gear cable

144: Rear gear cable

2: Sensing device

21: Torque sensor

22: Cadence Sensor

3: Electronic transmission device

31: control chip

32: Servo motor

33: First swing arm

34: second swing arm

4: Variable speed indicating device

41: Upshift button

42: Downshift button

43: gear display

Claims (5)

A bicycle speed change system is installed on a bicycle. The bicycle has a body, a steering handle pivoted on the front side of the body, a pedaling mechanism pivoted on the body, and a speed change mechanism provided on the body, The transmission mechanism includes a front transmission, a rear transmission, and a front transmission cable and a rear transmission cable respectively controlling the front transmission and the rear transmission. The bicycle transmission system includes: a sensing device disposed on the pedaling mechanism , Used to detect the pedaling torque and pedaling frequency of the pedaling mechanism; an electronic transmission device, which is arranged on the vehicle body and can link the transmission mechanism and is electrically connected to the sensing device, wherein the electronic transmission device includes a control chip , A servo motor electrically connected to the control chip, and a first swing arm and a second swing arm respectively linked by the servo motor, the first swing arm and the second swing arm respectively control the front speed change cable And the tightness of the rear shifting cable; and a shift indicating device, arranged on the steering handle and electrically connected to the electronic shifting device, the shifting indicating device will send a shift command to the electronic shifting device, the electronic shifting device will be based on The information detected by the sensing device is linked to the transmission mechanism for shifting at an optimal shift timing. According to the bicycle shifting system described in item 1 of the scope of patent application, the electronic shifting device incorporates the information detected by the sensing device into an exponential smoothing method to predict the occurrence of the maximum torque as the best shifting timing, When the electronic transmission device receives a shift command, it will link the transmission mechanism to shift gears at the best shift timing. According to the bicycle shifting system described in item 1 of the scope of patent application, the shift indicating device includes an upshift button and a downshift button. According to the bicycle shifting system described in item 3 of the scope of patent application, the shift indicating device further includes a gear display. According to the bicycle transmission system described in the first item of the scope of patent application, the sensing device includes a torque sensor arranged on the pedaling mechanism and a cadence sensor arranged on the pedaling mechanism.

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