JP2989302B2 - Wireless speedometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle speed display device which detects a rotation of a wheel of a bicycle, calculates a traveling speed, and displays the calculated traveling speed.

[0002]

2. Description of the Related Art Conventionally, in this type of speed display device, as means for detecting the rotation of a wheel, a combination of a magnet and a lead switch, a combination of a magnet and a Hall IC, a photo interrupter, and the like are used. For example, in the case of a combination of a magnet and a lead switch, a magnet is attached to a spoke of a wheel, a lead switch is attached to a fork supporting the wheel, and the magnet is detected by a reed switch. Thus, a wheel speed signal is obtained, a running speed is calculated based on the wheel speed signal, and this is displayed on a display. Here, the wheel speed signal was transmitted via a lead wire to a main body case mounted on the handlebar.

[0003] However, the lead wire has a drawback in that a bent portion is formed by the operation of the handle, and the bent portion is liable to be broken. In addition, when mounting the device, there is a problem that it takes time and effort to wire the lead wire. .

Therefore, there has been provided a wireless type speed display device capable of transmitting a detection signal of the number of revolutions of a wheel to a main body case without using a lead wire. In this case, when the battery voltage on the transmission side becomes low even when the main body case is normal, the transmission signal does not reach the reception side, and the display speed and the traveling distance are erroneously displayed. However, it is difficult for the driver to determine whether the malfunction is due to a low battery voltage or a malfunction due to a failure of the main body.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a wireless type speed meter which allows a driver to recognize a malfunction of a display speed or a traveling distance caused by a decrease in a battery voltage on a transmission side. The task is to provide.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a fork supporting a wheel of a bicycle, a detecting means for detecting the rotation of the wheel, and a detecting means for detecting the rotation of the wheel. A sensor unit having a transmitting unit for wirelessly transmitting a signal is provided. A receiving unit for receiving a signal from the transmitting unit is provided on a main body unit attached to a driver's front position such as a handlebar of the bicycle, and a receiving unit for the receiving unit. In a wireless speed meter provided with a calculation unit for calculating a running speed, a running distance, and the like based on a received signal, and a display for displaying the running speed, a running distance, and the like, the voltages of the detection unit and the transmitting unit are adjusted. When the value falls below an appropriate value, the state is displayed on a display of the main body.

[0007]

In the wireless speedometer constructed as described above, the battery running state of the detecting means for detecting the rotation of the wheel and the transmitting section for wirelessly transmitting the detecting signal from the detecting means is determined by the main body section. Is displayed on the display device, the driver can immediately recognize that the battery voltage on the transmitting side has decreased. And, since this indication is displayed on the display only when the battery voltage becomes lower than the appropriate value, unlike the case where the remaining battery level is always displayed, the main unit required for display is displayed. The power on the unit side can be minimized, and the space for displaying such a state on the display unit is also minimum.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

A magnet holder 4 holding a magnet 3 is attached to a spoke 2 of a front wheel 1 of a bicycle, and a fork 5 supporting the front wheel 1 is opposed to a position of a locus of movement of the magnet 3 by a sensor unit. 6 is attached by an attachment 7. As shown in the block diagram of FIG. 2, a reed switch 8 for detecting the magnet 3 mounted on the front wheel 1, a waveform shaping circuit 9, a microcomputer 10, a transmission circuit 11, and , A transmission antenna 12, a transmission battery 13, and a voltage detection unit 14 for detecting the voltage of the transmission battery 13.

On the other hand, a main body 17 is attached to a handlebar 15 supported on the upper front part of the fork 5 via a support 16. As shown in the block diagram of FIG. 3, a receiving antenna 18 for receiving a transmission signal from the sensor unit 6 and a receiving circuit unit 19 for demodulating a reception signal received by the receiving antenna 18 are provided in the main body unit 17. A calculation unit 20 for calculating the traveling speed, the traveling distance, and the like, and an LCD display 21 for displaying the traveling speed, the traveling distance, and the like are provided. The receiving circuit section
Reference numeral 19 denotes an amplifier 22 for amplifying a received signal and a detection circuit 23 for demodulating the amplified received signal, and a microcomputer is used as the arithmetic unit 20.

That is, the magnet 3 held on the front wheel 1
The signal of the lead switch 8 operated by the above is shaped by the waveform shaping circuit 9 and processed by the microcomputer 10, then oscillated and amplified by the transmission circuit section 11. Then, the signal is transmitted from the transmission antenna 12 to the main unit 17. The transmission signal is received by the reception antenna 18 in the main body 17, and the wheel rotation signal is amplified by the reception signal, and
The signal is demodulated and then input to the arithmetic unit 20 to calculate a traveling speed, a traveling distance, and the like. This is displayed on the LCD display 21.

By the way, the voltage of the transmitting battery 13 is
If the wheel rotation signal can be transmitted sufficiently, the signal is not input from the voltage detection unit 14 to the microcomputer 10, but the value falls to a value at which the wheel rotation signal cannot be transmitted. Inputs a signal from the voltage detection unit 14 to the microcomputer 10, and the microcomputer 10 determines that the battery has run out. At this time, the microcomputer 10 processes the signal into a signal different from a signal synchronized with the rotation of the normal wheel, such as a continuous signal or a pulse having a long pulse time, and transmits the signal from the transmitting antenna 12.

The signal transmitted from the transmitting antenna 12 is received by the receiving antenna 18 in the main unit 17, the received signal is amplified by the amplifying unit 22, demodulated by the detection circuit 23, and sent to the arithmetic unit 20. Is entered. The arithmetic unit 20 determines whether the received signal is a normal signal or a signal different from the normal signal when the battery runs out, and when the battery runs out, as shown in FIG.
A mark such as 24 is displayed on the LCD display 21. With this mark 24, the driver can confirm that the battery on the transmitting side has run out. Here, FIG. 4 shows an embodiment of the LCD display 21, in which 25 indicates the speed, and 26 indicates the integrated traveling distance.

In FIG. 3, reference numeral 27 denotes a reference clock of the arithmetic unit 20, and reference numeral 28 denotes a switch for switching the display 26 to a clock or the like.

[0015]

According to the present invention, as is apparent from the above description, the driver immediately recognizes that the battery voltage on the transmitting side has become low by displaying it on the display unit of the main unit. It is possible to recognize an erroneous display speed or mileage caused thereby. In addition, this display
Since it is performed only when the battery voltage is lower than the proper value, unlike displaying the remaining battery level at all times, it is possible to minimize the power of the main unit required for display, Further, the space for displaying such a state occupying the display may be minimized, and the display can be miniaturized.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a block diagram showing the inside of a sensor unit according to an embodiment of the present invention.

FIG. 3 is a block diagram of the inside of a main body according to an embodiment of the present invention.

FIG. 4 is an embodiment of an LCD display.

[Explanation of symbols]

 1 Wheel 5 Hawk 6 Sensor 17 Body 21 Display

Claims (1)

(57) [Claims] A fork for supporting the wheel of a bicycle, a detection unit for detecting rotation of the wheel, and a sensor unit having a transmission unit for wirelessly transmitting a detection signal of the detection unit; A receiving unit that receives a signal from the transmitting unit, a calculating unit that calculates a traveling speed, a traveling distance, and the like based on a reception signal of the receiving unit; In a wireless type speed meter provided with a display for displaying a speed, a traveling distance, and the like, when the voltage of the detection means and the transmission section falls below an appropriate value, the state is displayed on a display of the main body section. A wireless type speed meter characterized by the following.