JPH0128283Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an engine that can prevent excessive fuel intake due to inertial rotation of the engine while the stop switch is turned on so that the primary wire of the ignition circuit is grounded when the engine is stopped. This invention relates to a stop control device.

Generally, in a gasoline engine equipped with a governor mechanism, the throttle lever of the carburetor can be set to a high speed side or a low speed side by adjusting the rotation of the governor control lever. The throttle lever is set to the low speed side, and during normal operation, the governor mechanism is adjusted to a predetermined rotation speed (high speed side), and the throttle lever is pulled and set to the high speed side accordingly. Therefore, when stopping the engine, after setting the throttle lever to the low speed side by adjusting the governor mechanism, turn on the stop switch so as to ground the primary wire of the ignition circuit. There was no excessive intake of fuel or blowback due to inertial rotation of the engine, and there were no problems when restarting.

However, general-purpose engines are connected to drive driven machines such as generators and welding machines, and the governor mechanism is adjusted and set to the required rotation speed of the driven machine. There may be cases where the rotation speed cannot be changed or the governor mechanism is difficult to operate.In such cases, it is common practice to operate the governor control lever, set it to the required rotation, and then fix the governor control lever. If you press the stop switch in this state to stop the engine, the carburetor throttle will remain set to the high speed side, so
A large amount of fuel is supplied due to the inertial rotation of the engine, causing too much fuel to be sucked into the cylinder and carburetor. Also, if the fuel that is not sucked into the cylinder is blown back to the air cleaner side and a large amount of fuel adheres to the cleaner element, or if there is a locally heated heat point in the muffler, the air-fuel mixture will be affected by the heat. This can cause afterburn, which can cause an explosion. In particular, when the engine stops after load operation and restarts immediately, the restartability and acceleration after startup are poor because the air-fuel ratio is too rich.

For this reason, Japanese Patent Application Laid-Open No. 57-32033 discloses a stop control device for an engine-driven generator as a prior art technique that prevents excessive fuel intake when the engine is stopped. This is designed to keep the throttle at a low speed position by energizing the solenoid and supplying power from the battery to the solenoid for a certain period of time even after the stop switch is turned on during low speed rotation. be. However, the prior art requires a battery as a power source for energizing the solenoid for a certain period of time after the stop switch is turned on, and also requires a plurality of electronic circuits to control its operation.

The present invention was developed in view of these circumstances, and uses a simple mechanical configuration to eliminate unnecessary fuel consumption without using a battery for excitation of the solenoid after the stop switch is turned on, or a control electronic circuit such as a delay circuit. It is an object of the present invention to provide an engine stop control device that prevents excessive suction and fuel blowback, improves restart performance and acceleration performance after restart, and prevents afterburn.
In order to achieve the above object, the engine stop control device according to the present invention normally sets the throttle lever to the high speed side by the governor spring of the governor mechanism, and is turned on by the stop operation of the stop switch operating body, and the engine stop control device of the present invention In the engine equipped with a stop switch that stops the rotation of the engine by grounding a wire, the stop switch operating body follows the stop operation to move the throttle lever toward a low speed side against a governor spring. A valve is provided and configured to follow the above-mentioned stop operation to shut off the fuel supply passage leading from the float chamber to the main nozzle.

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 relate to an embodiment of the engine stop control device of the present invention, FIG. 1 is a front view of the device of the present invention, and FIG. 2 is a diagram showing a governor mechanism and a carburetor in a stop operation state. FIG. 3 is a partially cutaway front view showing the governor mechanism and carburetor in an operating state, and FIG. 4 is a sectional view of the stop switch.

In these figures, reference numeral 1 is the engine, 2 is the carburetor, and 3 is the governor mechanism, which is pressed and rotated by the movement of the governor weight, governor sleeve, etc. (not shown), and the governor lever 5 and governor control lever 6, on which the governor shaft 4 is pivoted, are connected. A governor spring 7 is stretched between them, and one end of the governor lever 5 and a throttle lever 8 of the carburetor 2 are connected by a governor rod 10 around which a rod spring 9 is wound. and,
In the present invention, the governor lever 5 is rotated to the high speed side by the biasing force of the governor spring 7 by adjusting the rotation of the governor control lever 6, and accordingly, the throttle lever 8 is always set to rotate to the high speed side. It is becoming more and more common.

The governor lever 5 has a governor shaft 4 side, which is a rotating shaft, bent and extended horizontally below the carburetor 2, and this extension part 11 is formed into an L-shaped cross section, so that a stop switch 12 faces the bottom surface of the carburetor 2. It is arranged. This stop switch 12 is
A contact 14 connected to the primary line of the ignition circuit via a cable and a ground side contact 15 are installed inside the main body 13, while a switch operating body 16 is attached to the surface opening of the main body 13 in a protruding state.
The switch has a contact piece 17 on the bottom surface thereof, and is turned on and off by bringing the contact piece 17 into contact with and separating from the contacts 14 and 15, and the switch operating body 16 is separated by a built-in return spring 18. is biased in the direction. The operating body 16 of the switch 12 has a rod 19 extending from the bottom surface of the main body 13 at its bottom, and can be slid in the approaching direction by pressing the operating body 16 and separated by the biasing force of the return spring 18. By sliding in the direction, the main body 1
It is designed to protrude and sink toward the bottom of 3.

The carburetor 2 has at its bottom a fuel supply passage 22 that communicates with the float chamber 20 on the upstream side and communicates with the main nozzle 21 on the downstream side. A portion of the bottom of the carburetor 2 bulges downward, and a plunger valve 24 is disposed within this bulge 23, penetrating vertically. The plunger valve 24 has an upper end that opens and closes the fuel supply passage 22 of the carburetor 2, and a lower end that opens and closes the fuel supply passage 22 of the carburetor 2.
3 The stop switch 1 protrudes downward from the bottom surface.
This stop switch 12 is opposite to the rod 19 of 2.
By operating the switch operating body 16, the rod 19 is pushed back and the plunger valve 24 is slid. A diaphragm 25 is disposed between the outer periphery of the plunger valve 24 and the inner wall of the carburetor bulging portion 23 to make the carburetor float chamber 20 or the fuel supply passage 22 liquid-tight. A coil spring 26 is wound around the outer circumference of the plunger valve 24, and the plunger valve 24 is normally biased in the direction in which the fuel supply passage 22 is opened, that is, downward as shown in FIG. .

Note that the reference numeral 27 in the figure indicates a throttle valve.

In this configuration, as shown in FIGS. 1 and 3, the carburetor throttle lever 8 is normally set to the high speed side by adjusting the governor control lever 6. Further, the fuel supply passage 22 is opened by sliding the plunger valve 24 downward due to the biasing force of the coil spring 26, so that the fuel in the float chamber 20 passes through the fuel supply passage 22 and reaches the main nozzle 21.
It is then supplied to the carburetor bench.

On the other hand, when the engine is stopped, the throttle lever 8 is set to the high speed side by the governor mechanism 3, and the bent extension part 11 of the governor lever 5 is
The switch operating body 1 of the stop switch 12 arranged in
6 in the direction indicated by the arrow in FIG. 1, the governor lever 5 rotates around the governor shaft 4 in a direction that pulls the throttle lever 8 toward the low speed side (counterclockwise in FIG. 1). The throttle lever 8 is rotated toward the low speed side against the urging force of the governor spring 7 toward the high speed side due to the setting of the governor mechanism, and the throttle valve 27 is closed. When the switch operating body 16 of the stop switch 12 is pressed, the rod 19 projects and pushes up the plunger valve 24 against the coil spring 26, closing the fuel supply passage 22 and closing the float chamber 20.
The fuel supplied from the main nozzle 21 to the main nozzle 21 is cut off. Further, when the stop switch 12 is turned on, the primary wire of the ignition circuit is grounded and the rotation of the engine gradually decreases. Therefore,
By continuing to press the switch operating body 16 of the stop switch 12 until the engine completely stops rotating, not only can the throttle lever 8 be maintained on the low speed side, but also the fuel can be supplied from the float chamber 20 to the main nozzle 21. This can completely cut off unnecessary fuel intake due to inertial rotation of the engine and prevent the intake fuel from blowing back. After the engine has completely stopped, releasing the pressure on the switch operating body 16 of the stop switch 12 turns off the switch 12.
The throttle lever 8 is pulled toward the high speed side again by rotating the governor lever 5 to return to the state shown in FIG. The plunger valve 24 which had been blocking the fuel supply passage 22 is also returned by the spring 26 and the fuel supply passage 22 is closed.
is opened, and fuel is normally supplied from the float chamber 20 to the main nozzle 21.

As explained above, according to the present invention, when the governor mechanism sets the throttle to the high speed side, the governor spring of the governor mechanism is moved to the high speed side in accordance with the stop operation of the engine stop operation body. Move the throttle valve in the closing direction against the force.
At the same time as the maintenance operation, the fuel supply passage leading from the float chamber to the main nozzle is shut off at the same time, so there is no wasted fuel, and no fuel is accumulated in the cylinder when restarting, so starting due to excessive air-fuel ratio is not possible. Problems such as defects are improved, and there is no fuel blowback, which prevents wetting and contamination of the air cleaner element.

[Brief explanation of the drawing]

1 to 4 relate to an embodiment of the engine stop control device of the present invention, FIG. 1 is a front view of the device of the present invention, and FIG. 2 is a diagram showing a governor mechanism and a carburetor in a stop operation state. FIG. 3 is a partially cutaway front view showing the governor mechanism and carburetor in an operating state, and FIG. 4 is a sectional view of the stop switch. 2... Carburetor, 3... Governor mechanism, 5...
Governor lever, 7... Governor spring, 8...
Throttle lever, 12...stop switch, 16
...stop switch operating body, 20...float chamber,
22...Fuel supply passage, 24...Valve.

Claims (1)

[Scope of utility model registration request] The throttle lever is normally set to the high speed side by the governor spring of the governor mechanism, and the stop switch is turned on by the stop operation of the stop switch operating body to ground the primary wire of the ignition circuit and stop the rotation of the engine. The stop switch operating body is disposed so as to move the throttle lever toward a low speed side against a governor spring in response to the stop operation, and the float chamber is moved in response to the stop operation. An engine stop control device comprising a valve that shuts off a fuel supply passage leading from the main nozzle to the main nozzle.