JPH0245821Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a kill switch that is installed on large motorcycles in particular, and which manually cuts off the power voltage supply to the engine ignition system to immediately stop the engine in an emergency. The present invention relates to a tachometer needle shake prevention circuit caused by.

In recent years, especially large motorcycles, in order to ensure the safety of the occupants in the event of a vehicle tipping over, a dedicated engine stop switch has been installed, allowing the vehicle to temporarily stop, for example, to run errands or have a conversation with others. Sometimes, a method is used to simply stop the engine using the engine stop switch described above without turning off the key switch each time.

In general, on motorcycles, the key switch operation part that connects the power to electrical equipment such as instruments is installed near the instrument mounting part in the center of the handlebar, especially when riding on a large vehicle and falling due to a slip or other cause. Due to their weight, they cannot stand up immediately, and the engine cannot be immediately stopped to prevent the occupants from being in danger due to the rotation of the drive wheels. In recent years, in order to avoid such dangers to occupants, an open/close switch that connects the key switch to the engine ignition system has been installed near the handle grip, as shown in Figure 1. If the vehicle falls over, the engine can be stopped immediately by operating the switch with the thumb. The configurations that allow this are becoming standardized. That is, accelerator grip 1
Attach the left/right rotating switch knob 2 near the
The power supply path to the engine ignition system is connected at the center position (RUN display), and the power supply path is opened at the left and right rotation position (OFF display) regulated by the locking pins 3 and 4, In the event of a fall, the switch knob 2 can be turned to the OFF position with the thumb of the right hand without any movement from the accelerator operation with the right hand, and the engine can be stopped immediately. , it is possible to prevent burnout accidents caused by gasoline ignition. Note that 5 is a slide switch for direction indication, and 6 is a push switch for engine starter.

By the way, when the switch for stopping the engine (hereinafter referred to as the kill switch) opened and closed by the switch knob 2 is closed when the key switch is closed, the needle of a moving coil type tachometer for indicating the engine speed, etc. It may cause vibration.

FIG. 2 is a conventional circuit diagram showing the connection relationship between a kill switch and a tachometer. A drive circuit 9 with a differential and waveform shaping circuit is connected from an on-vehicle battery 7 through a key switch 8, and the output of the drive circuit 9 is A tachometer 10 consisting of a moving coil type indicator, which is known per se, is connected.

An ignition coil 12 is connected to the key switch 8 through a kill switch 11, and the ignition coil 12 is configured to control energization to the spark plug by grounding and opening operations by an engine ignition timing circuit 13 such as a transistor igniter.

In this case, a pulse signal proportional to the engine rotation to the tachometer drive circuit 9 is supplied from the level change at the output terminal of the timing circuit 13 as shown in the figure. It is easily understood from the principle of operation that when noise unrelated to engine rotation is input, the pointer of the tachometer 10 instantaneously jumps up through the drive circuit 9.

Now, if the kill switch 11 is left open and the key switch 8 is closed, power will not be supplied to the engine ignition system, and voltage will be supplied only to the instrument electrical components including the tachometer 10 (drive circuit 9). Here, in order to start the engine, the kill switch 11 and the starter switch 6 shown in FIG. A rising waveform due to voltage application is input, and through differentiation and waveform shaping processing inside the circuit, just one pulse of noise signal is supplied to the tachometer as a rotation detection pulse, and one pulse of electricity is applied to the movable part of the tachometer 10. This causes the pointer to momentarily jump, resulting in an unsightly needle runout phenomenon. Normally, the purpose of opening and closing the kill switch 11 is to immediately stop the engine when the vehicle overturns, but occupants sometimes need to stop temporarily to run errands or have a conversation with an acquaintance, and generally, the Key switch 8 at a time
There is a trend toward using the kill switch 11, which can be operated extremely easily with the thumb of the right hand, to avoid the trouble of stopping the engine by opening the switch.

After stopping the engine by opening the kill switch 11, when restarting the engine, the kill switch 1 is
1 is closed, one pulse input due to voltage application to the input terminal of the drive circuit 9 described above causes the pointer of the tachometer 10 to instantaneously jump significantly, resulting in a needle runout phenomenon that is extremely annoying to the occupants. This creates an impression of discomfort, which can lead to instrument malfunction.

The object of the present invention is to provide a highly reliable tachometer that always gives an instruction related to the engine speed without causing any needle deflection even when the kill switch for stopping the engine is closed.

FIG. 3 is an electrical wiring diagram showing an embodiment of the tachometer anti-shake circuit according to the present invention, in which the same components as in the conventional circuit of FIG. 2 are given the same reference numerals. In the figure, the power supply voltage supply to the tachometer drive circuit 9 is controlled by a shaping circuit 14 and a switching circuit 15, which are operated by opening and closing a kill switch 11.

That is, even if the key switch 8 is simply closed while the kill switch 11 is open, no voltage is supplied to the drive circuit 9, and the kill switch 11
This provides a delay operation that prevents the tachometer 10 from operating even if the tachometer 10 is closed and one pulse as a noise signal is input to the pulse input terminal.

To explain the specific configuration here, the shaping circuit 14
is the resistor 1 connected from the negative side of the kill switch 11
6, the switching circuit 1 is composed of a diode 17 and a capacitor 18 with a relatively large capacity.
The control output to 5 is provided with a delay by capacitor 18. The switching circuit 15 is composed of a transistor 21 which is biased through resistors 19 and 20 by the delayed output from the shaping circuit 14, and a transistor 24 which is biased through resistors 22 and 23 by conduction of the transistor 21 and supplies voltage to the drive circuit 9. be done.

In the above configuration, the operation of preventing needle runout of the tachometer 10 will be explained.

Now, if key switch 8 is closed and kill switch 11 is open, transistor 2
1 and 24 are both in a cutoff state, and no voltage is supplied to the drive circuit 9 and the engine ignition system. Here, when the kill switch 11 is closed to start the engine, the power supply voltage from the vehicle battery 7 is applied to each input terminal of the shaping circuit 14 and the drive circuit 9. In the shaping circuit 14, the rise of the voltage is controlled by the resistor 16.
Since the delay is caused by the capacitor 18, the transistor 21 (transistor 24) in the switching circuit 15 does not become conductive immediately;
It will be biased with a slight delay due to the increase in the delay of capacitor 18. Therefore, voltage is supplied to the drive circuit 9 due to conduction of the switching circuit 15 with a slight delay from when voltage is applied to the input terminal due to closing of the kill switch 11. When the circuit 9 is activated, the one-pulse noise signal caused by the voltage applied to the input terminal disappears, so the pointer of the tachometer 10 does not jump due to the noise signal caused by the closing of the kill switch 11, and the engine rotation due to the starter starts. A stable rotation instruction can be obtained by inputting a regular pulse signal proportional to the number of rotations.

In the embodiment described above, the input of the shaping circuit 14 is directly connected to the negative side of the kill switch 11, but it is also possible to connect it to the output of the timing circuit 13, which is the same as the output line to the drive circuit 9. This has the advantage that the wiring can be routed easily by using a common connection terminal. In this case, compared to connecting to the negative side of the kill switch 11, there is a difference that a pulse input occurs when the engine starts, but the shaping circuit 14
By setting the capacitance of the capacitor 18 relatively large, the output voltage to the switching circuit 15 can be supplied as a smoothed DC voltage, keeping the transistors 21 and 24 conductive and cutting off the voltage supply to the drive circuit 9. It will not be done.

As described above, the tachometer needle deflection prevention circuit of the present invention can reliably prevent the tachometer pointer from jumping up when the engine stop kill switch is closed, and can easily stop the engine using the kill switch for the occupant. It is possible to provide a highly reliable tachometer that eliminates the discomfort caused by needle deflection during subsequent restarts.

[Brief explanation of the drawing]

Fig. 1 is an external view of an operating knob equipped with a kill switch for stopping the engine near the handle grip of a motorcycle, and Fig. 2 is an electrical wiring diagram showing a conventional example of a voltage supply path to a tachometer for a motorcycle equipped with the kill switch. FIG. 3 is an electrical wiring diagram showing an embodiment of the tachometer needle shake prevention circuit according to the present invention. Key switch...8, Drive circuit...9, Tachometer...10, Kill switch...11, Ignition coil...12, Engine ignition timing circuit...13, Shaping circuit...14, Switching circuit...15.

Claims (1)

[Scope of utility model registration request] In the voltage supply circuit for a tachometer equipped with a kill switch that manually cuts off the voltage supply to the engine ignition system of a motorcycle and makes it possible to immediately stop the engine in an emergency, the power supply line from the kill switch to the engine ignition system is A shaping circuit that delays the voltage rise due to closing of the kill switch is connected to the arbitrary voltage terminal, and a power supply path from the key switch to the tachometer drive circuit is operated according to the output state of the shaping circuit to control opening and closing of the power supply path. A tachometer needle shake prevention circuit characterized by connecting a switching circuit.