JPH06317601A - Speedometer for bicycle - Google Patents

Abstract

PURPOSE:To provide a bicycle speedometer which can easily inform a driver of a gear position. CONSTITUTION:A bicycle speedo meter is composed of a wheel revolution detecting section 7 to detect the number of revolutions of the rear wheel 2 of a bicycle 1; a crank revolution detecting section 10 to detect the number of revolutions of a crank 8; a computing means to compute the running speed of the bicycle and the number of revolutions of the crank on both the rotational signal of the wheel output from the wheel revolution detecting section 7 and the rotational signal of the crank 8 output from the crank revolution detecting section 10; and a liquid crystal display section to display the running speed and the number of revolutions of the crank. The gear position of the bicycle is computed on the ratio of the front gear to the rear gear of the bicycle, the number of revolutions of the rear wheel 2 and the number of revolutions of the crank 8 which are previously input by the computing means. The gear position is then displayed through the crystal display section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle speedometer. More specifically, the present invention relates to a bicycle speedometer that calculates and displays running data such as the traveling speed of a bicycle and the number of revolutions of a crank.

[0002]

2. Description of the Related Art A conventional bicycle speedometer calculates running data such as a running speed and a running distance of a bicycle by detecting the number of rotations of wheels, or displays the number of rotations of wheels of a bicycle. By detecting the crank rotation speed, the traveling speed, traveling distance, crank rotation speed, etc. are calculated and displayed.

On the other hand, recent bicycles are provided with an extremely large number of gears so that the bicycle can be run in a gear suitable for the driver even under various driving conditions from the viewpoint of improving sports running performance.

[0004]

When a bicycle such as this is run, the driver cannot easily know which gear he is currently running. In sports driving, if the driver does not know in which gear he / she is traveling, there is a problem that a gear change is delayed or a gear change is missed, resulting in time loss. In addition, the torque applied to the crank suddenly changes due to a shift error, which poses a problem that the bicycle is wobbled and is dangerous.

The present invention has been made in view of the above problems, and an object thereof is to provide a bicycle speedometer capable of easily informing a driver of a gear position.

[0006]

A bicycle speedometer according to the present invention comprises a wheel rotation speed detecting means for detecting a rotation speed of a bicycle wheel, a crank rotation speed detecting means for detecting a rotation speed of a crank of a bicycle, Calculating means for calculating the traveling speed and the crank rotation speed of the bicycle from the rotation signal of the wheel output from the wheel rotation speed detecting means and the rotation signal of the crank output from the crank rotation speed detecting means;
At least the display unit for displaying the traveling speed, based on the gear ratio of the front gear and rear gear of the bicycle and the rotation speed of the wheel and the rotation speed of the crank, which are input in advance, the gear position of the bicycle is calculated by the calculating means. The gear position is calculated and displayed on the display unit.

[0007]

According to the present invention, in a speedometer for displaying the crank rotation speed, running speed, etc. of a bicycle, the gear ratio is preset without any sensor other than the crank rotation speed detecting means and the wheel rotation speed detecting means. It is possible to calculate an accurate gear position at that time on the basis of the gear ratio, the crank rotation speed, and the traveling speed and display it on the display unit simply by inputting the value into the calculating means.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A speedometer of the present invention will be described with reference to the drawings. 1 is a front view of a bicycle equipped with a speedometer, which is an embodiment of the speedometer of the present invention.
[Fig. 2] is an enlarged plan view of an essential part near the chain stay of the bicycle shown in Fig. 1.

As shown in FIG. 1, magnets 4 are attached to the spokes 3 of the rear wheel 2 of the bicycle 1. Rear wheel 2
A wheel rotation speed detection unit 7 incorporating a reed switch (not shown) is mounted on the rotation locus of the magnet 4 accompanying the rotation of the rear wheel 2 of the chain stay 6 of the frame 5 that supports the wheel.

Also, a magnet 9 is attached to the left crank 8 of the bicycle 1, and a crank rotation in which a reed switch (not shown) is built in is on the rotation locus of the magnet 9 accompanying the rotation of the crank 8 of the chain stay 6. Number detector
10 is installed.

On the other hand, the speedometer main body 12 is detachably attached to the handlebar 11 of the bicycle 1 via the bracket 13, and the wheel rotation speed detecting section 7 and the crank rotation speed detecting section 10 are connected via the cord 14 to the speedometer. It is electrically connected to the main body 12.

FIG. 3 is a front view of the speedometer main body 12 shown in FIG. 1, and 16 is a liquid crystal display section for displaying the crank rotation speed and traveling speed. Reference numeral 17 denotes a mode change switch, which can change the display mode of the lower display of the liquid crystal display unit 16 each time the switch is pressed. In this embodiment, a clock display mode for displaying the time, a maximum speed display mode for displaying the maximum speed, a traveling distance display mode for displaying the traveling distance, an integrated distance display mode for displaying the accumulated distance, and an average speed display for displaying the average speed. The mode, the elapsed time display mode for displaying the elapsed time, and the cadence display mode for displaying the number of revolutions of the crank can be sequentially switched (FIG. 4).
reference). Further, 18 is an ST / STOP (start / stop) switch for instructing the start and end of the traveling distance, the average speed and the elapsed time.

FIG. 5 is an explanatory plan view of the liquid crystal display unit 16 (a).
Is an explanatory diagram of full lighting display, and (b) is an explanatory diagram of a specific usage example. As shown in FIG. 5 (a), 19 in the upper stage is a traveling speed display unit, 20 in the lower stage is a numerical value display unit for displaying the numerical values of each mode, 21 is a position display unit of the front gear, 22 is a rear gear position display section.
(B) shows the cadence display on the numerical display 20, the OUTER gear on the front gear position display 21, and the rear gear position display 22 when the rear gear is a five-stage gear. However, for the rear gear, the gear with the largest number of teeth is 1
2 steps ... 7 steps. Although the speedometer shown in this embodiment has two front gears and seven rear gears, the number of stages is not limited to these.

Next, the operation will be described with reference to the flow charts of FIGS. 1 to 5 and FIG.

First, when the power source of the speedometer is turned on, the liquid crystal display section 16 is in a fully lit state as shown in FIG. 5 (a). Next, the unit display unit 23 for the traveling speed is set to the setting state of kilometers per hour [km / h] or miles per hour [mile / h]. At this time, the speed unit is selected by the mode changeover switch 17 and set by the ST / STOP switch 18 (step S1). After setting the speed unit, the circumferential length of the rear tire is set. At this time, the mode switch 17
The numerical value of the circumference is selected by the operation of and is set by the ST / STOP switch 18 (step S2). After setting the circumferential length, the number of teeth of the gear is set. At this time, the number of teeth of the gear is selected by operating the mode selector switch 17, and the ST / S
Set with TOP switch 18. This operation is sequentially performed for the inner and outer gears of the front gear and the 1st to 7th gears of the rear gear (step S3). After setting all the gear teeth,
A microcomputer (not shown) in 12 calculates and stores the gear ratio of each gear combination (step S
4). As described above, the bicycle is run after executing S1 to S4.

During traveling, when the magnets 4 attached to the spokes 3 of the rear wheels 2 circularly move with the rotation of the rear wheels 2 and pass near the wheel rotational speed detecting portion 7 attached to the chain stay 6, A reed switch (not shown) inside the wheel rotation speed detection unit 7 opens and closes to output a wheel rotation signal. Similarly, as the magnet 8 attached to the crank 8 moves circularly as the crank 8 rotates, a reed switch (not shown) inside the crank rotation speed detector 10 attached to the chain stay 6 is also provided. Opens and closes
A crank rotation signal is output (step S5). The wheel rotation signal and the crank rotation signal are input to a control circuit (not shown) inside the speedometer main body 12 via a cord 14.

The control circuit calculates the wheel rotation speed and traveling speed based on the wheel rotation signal and the preset wheel circumference (step S6), and the liquid crystal display unit 16
(Step S7). Further, the crank rotation speed is calculated based on the crank rotation signal (step S
8). This crank rotation speed is displayed on the liquid crystal display unit 16 when the mode change switch 17 is pressed to enter the cadence display mode (step S9). Next, the ratio of the rotational speeds is obtained from the wheel rotational speed and the crank rotational speed (step S10) and compared with the gear ratio previously obtained (step S11), and the gear position is obtained and displayed on the liquid crystal display unit 16 (step S10). S12). The gear position display is shown in Fig. 5.
As shown in (b), the current rear gear position 5 is displayed in white on the rear gear position display portion 22. on the other hand,
The current gear position is displayed on the front gear position display section 21 as either "OUTER" or "INNER".

Further, when the display mode is changed during traveling, the mode changeover switch 17 is pressed to switch in the order shown in FIG. 4, and the current display mode is shown on the mode display section 24 (see FIG. 5A). .

Next, the front gear 2 steps, the rear gear 7 steps,
A specific method of calculating the gear position in the case of a bicycle having a wheel diameter of 26 inches will be described with reference to Table 1.

[0020]

[Table 1]

First, as shown in Table 1, the number of teeth of the front gear () and the rear gear () is stored in the microcomputer in the speedometer body 12 by operating the mode changeover switch 17 and the ST / STOP switch 18. Let Table 1 for microcomputers
Then, the gear ratio for each combination is calculated from the input number of gear teeth. During traveling, a wheel rotation signal from the wheel rotation speed detection unit 7 and a crank rotation signal from the crank rotation speed detection unit 10 are input to a microcomputer incorporated in the speedometer body 12. The respective rotation speeds are calculated from these signals. For example, if the wheel rotation speed is calculated to be 240 rpm (about 30 km / h) from the bicycle wheel rotation signal, and the crank rotation speed at this time is calculated to be 60 rpm, take the ratio of these rotation speeds and obtain 60 rpm / 240r
pm = 0.2500 and the rotation speed ratio can be obtained. The gear ratio in Table 1 in which the ratio of the rotational speeds matches is searched for. In the above case, the front gear is the OUTER gear and the rear gear is the same as the 6th gear. As a result, the microcomputer determines that the front gear is the outer gear and the rear gear is the sixth gear, and the liquid crystal display unit 16 displays the front and rear gear positions.

In the above embodiment, the magnet and the reed switch are used for detecting the rotation speed of the rear wheel and the rotation speed of the crank, but the application of the idea of the present invention is not limited to this. Any other means can be used as long as it can detect the rotation signal associated with the rotation of the crankshaft and the rotation signal associated with the rotation of the crank, and can calculate and display the crank rotation speed, the traveling speed, etc. based on the rotation signal. it can. Further, the items displayed on the speedometer are not limited to those in this embodiment, and the present invention can be applied to all speedometers that display gear positions.

[0023]

According to the present invention, since the current gear position is displayed on the display portion of the speedometer, the position of the gear position during driving can be easily recognized by the bicycle driver. Lost time due to delay in change or gear change mistake can be prevented. There is also an effect that it is possible to prevent the bicycle from wobbling due to a sudden change in the torque applied to the crank due to a gear change mistake. Furthermore, since another sensor for detecting the gear position is not required, the structure is simple and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of a bicycle equipped with a speedometer that is an embodiment of the speedometer of the present invention.

FIG. 2 is an enlarged plan view of an essential part near the chain stay of the bicycle shown in FIG.

FIG. 3 is a front view of the speedometer body of FIG.

4 is an explanatory diagram of a display mode of the speedometer of FIG.

5A and 5B are plan explanatory views of a liquid crystal display portion of the speedometer of FIG. 1, FIG. 5A is an explanatory view of full lighting display, and FIG. 5B is an explanatory view of a specific usage example.

FIG. 6 is a flowchart showing an operation procedure of the speedometer of FIG.

[Explanation of symbols]

 1 Bicycle 2 Rear wheel 7 Wheel speed detector 8 Crank 10 Crank speed detector 12 Speedometer body

Claims (1)

[Claims] 1. A wheel rotation speed detecting means for detecting a rotation speed of a bicycle wheel, a crank rotation speed detecting means for detecting a rotation speed of a bicycle crank, and a wheel rotation output from the wheel rotation speed detecting means. A bicycle input in advance, which comprises a calculating means for calculating the traveling speed and the crank rotation speed of the bicycle from the signal and the crank rotation signal output from the crank rotation speed detecting means, and a display section for displaying at least the traveling speed. A bicycle speed in which the gear position of the bicycle is calculated by the calculating means based on the gear ratio between the front gear and the rear gear, the rotation speed of the wheel, and the rotation speed of the crank, and the gear position is displayed on the display unit. Meter.