JPH0350380A - Starter of motorcycle engine - Google Patents

Abstract

PURPOSE:To reduce capacity of a starter motor by a method wherein a decompressor is operated to drive the starter motor at the time of starting an engine, and when the number of engine rotations reaches a specific value, the decompressor is released as well as the starter motor is stopped simultaneously to start ignition. CONSTITUTION:At the time of starting an engine, by turning ON a main switch 5 and a starter switch 6, the contact of a cutoff relay 7 and a starter relay 2 is self-held so that power is supplied to a starter motor 3, a fuel cutting solenoid 9 and a compressor solenoid 10. Thus the starter motor 3 is rotated as well as fuel supply to a carburetor is cut and an exhaust valve is opened by the decompressor. When the number of engine rotations reaches a specific value, the starter switch 6 is turned OFF, fuel supply to the carburetor is started and opening of the exhaust valve is canceled by the decompressor as well as ignition of the engine is started.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a starting device for a motorcycle engine.

[Prior Art] Conventionally, vehicle engines that are started by slowing down the rotation of a starting motor and rotating a crankshaft are known to be equipped with a decompression device. This reduces the compression load in the combustion chamber by activating the decompression device when the starting motor rotates and opening the exhaust valve that also serves as the decompression valve, and when the engine speed increases, the decompression device This method closes the exhaust valve and starts after the compression and explosion strokes. Note that in cases where there is no exhaust valve, such as in a two-stroke engine, a decompression valve is provided independently. Figure 5 shows the crankshaft rotation speed without the decompression device, and Figure 6 shows the crankshaft rotation speed when the decompression device is activated.When the decompression device is activated, the rotation speed becomes stable, making starting easier. can be done.

[Problems to be Solved by the Invention] Incidentally, there are restrictions on the capacity of the starting motor and battery mounted on a motorcycle. Therefore,
In the above-mentioned conventional starting method, torque acts on the starting motor during the compression stroke when the exhaust valve is closed by the decompression device, or when the piston explodes before the top dead center of the piston, which adversely affects the motor. However, there is a problem in that a large current flows through the starting motor, making ignition by the battery unstable.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a starting device for a motorcycle engine that can reduce the capacity of a starting motor and a battery.

[Means for Solving the Problems] To this end, the motorcycle engine starting device of the present invention includes a decompression device 10 that communicates the combustion chamber of the engine with the atmosphere, and in an engine started by the starting motor 3. , operates the decompression device to communicate the combustion chamber with the atmosphere, and also operates the starting motor 3.
After the engine speed reaches a predetermined speed (2), the decompression device 10 is released, and at the same time, the starting motor 3 is de-energized and the engine is ignited.

Note that the numbers added to the above configurations are for comparison with the drawings, and the configurations of the present invention are not limited thereby.

[Operation] In the present invention, for example, as shown in FIG. 1, when the main switch 5 is turned on and the starter switch 6 is turned on,
The starting motor 3, the fuel cut solenoid 9, and the decompression solenoid 10 are energized to rotate the starting motor 3, cut off the fuel supply to the carburetor, and operate the decompression device to open the exhaust valve. The exhaust valve is opened and the compression load on the combustion chamber is reduced, so even if the starting motor 3 is small, its rotational speed increases without difficulty, and when it reaches the rotational speed N shown in Fig. 2, the starter switch 6 is turned off. When turned off, the starting motor 3, fuel cut solenoid 9, and decompression solenoid 10 are de-energized. Therefore, fuel supply to the carburetor is started, and at the same time, the decompression device is operated and the exhaust valve is closed. The starting motor 3 uses its inertia to rotate the crankshaft, during which time the engine is ignited.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a control circuit diagram showing one embodiment of the starting device of the present invention, in which a starting motor 3 is connected to a battery 1 via a starter relay 2, and a main switch 5 and a starter switch 6 are connected to the battery 1. A cut-off relay is connected to the relay, and a fuel cut solenoid 9 that cuts off fuel supply to the carburetor, a decompression solenoid 10 that operates a decompression device and releases an exhaust valve, and the starter relay 2 are connected to the relay. has been done.

The operation of the starting device constructed as described above will be explained with reference to FIG.

When the starter switch 6 is turned on after the main switch 5, the contacts of the cutoff relay and the starter relay 2 are self-held, and the starting motor 3, the fuel cut solenoid 9, and the decompression solenoid 10 are energized. Therefore, the starting motor 3 is rotated,
It also cuts off the fuel supply to the carburetor and activates the decompression device to open the exhaust valve.

The exhaust valve opens and the compression load on the combustion chamber decreases, so even if the starting motor 3 is small, its rotational speed rises without difficulty, and when it reaches the rotational speed N shown in Fig. 2, the starter switch 6 is turned off. When turned off, starting motor 3, fuel cut solenoid 9 and decompression solenoid 1
0 is turned off. Therefore, fuel supply to the carburetor is started, and at the same time, the decompression device is operated and the exhaust valve is closed. The starting motor 3 uses its inertia to rotate the crankshaft about 3 to 4 times, during which time the engine is ignited.

Incidentally, in order to increase the inertial force of the starting motor 3, the rotation speed N is set high. For this purpose, the gear ratio between the starting motor 3 and the crankshaft is set low.

Next, another embodiment of the present invention will be described with reference to FIG.

In this embodiment, a control unit 11 is provided in place of the cutoff relay shown in FIG. This control unit 11 controls the starting motor 3, the fuel cut solenoid 9, and the decompression solenoid 10 to be energized when the starter switch 6 is turned on, and also controls to turn them off after a certain period of time. It is.

FIG. 4 shows yet another embodiment of the invention. In this embodiment, the ignition unit 12 outputs a signal indicating the engine speed to the control unit 11, and when the engine speed reaches a preset speed, the starting motor 3, fuel cut solenoid 9, and decompression solenoid 10
This controls the power supply to be turned off.

[Effects of the Invention] As explained above, in the present invention, when the starting motor is energized, the decompression device is activated to communicate the combustion chamber with the exhaust side, and when the engine is ignited, the decompression device is released and the starting motor is activated. Since the electricity is turned off, during the compression stroke when the exhaust valve is closed, or when the piston explodes before the top dead center, torque will not be applied to the starting motor and have no adverse effect on the motor. A large current does not flow through the starting motor, making ignition by the battery more stable.

Furthermore, since the load due to compression in the combustion chamber is reduced, the capacities of the starting motor and battery can be reduced in size.

Furthermore, since the fuel supply is cut off while the decompression device is in operation, afterfire can be prevented.

[Brief explanation of drawings]

FIG. 1 is a control circuit diagram showing one embodiment of the starting device of the invention, FIG. 2 is a diagram for explaining the invention in detail, and FIGS. 3 and 4 are diagrams showing other embodiments of the invention. The control circuit diagrams shown in FIGS. 5 and 6 are diagrams for explaining a conventional example. 3...Starting motor, 6...Starter switch, 9...Fuel cut solenoid, 10...Decompression solenoid.

Claims (2)

[Claims] (1) In an engine that has a decompression device that communicates the combustion chamber of the engine with the atmosphere side and is started by a starting motor, the decompression device is operated to communicate the combustion chamber with the atmosphere side and energizes the starting motor. A starting device for a motorcycle engine, characterized in that, after the engine speed reaches a predetermined amount, a decompression device is released, and at the same time, electricity is turned off to the starting motor to ignite the engine. (2) The motorcycle engine starting device according to claim 1, wherein fuel supply is cut off while the decompression device is in operation.