JPS5833243Y2 - 2-cycle engine exhaust gas control device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an exhaust gas control device for a two-stroke engine such as an automobile.

In two-stroke engines, when decelerating or at low speeds, fresh air and exhaust gas are not sufficiently exchanged, resulting in non-combustion, and the exhaust gas contains a large amount of unburned components, increasing the emission of harmful gases.

This invention has been improved in view of these points, and an embodiment of the invention shown in the drawings will be described below.

A butterfly-shaped on-off valve 5 is rotatably attached to an exhaust pipe 3 connected to an exhaust hole 2 of an engine 1 so as to narrow a flow path 4.

Then, the lever 6 of the on-off valve 5 is urged by a spring 7 so that the on-off valve 5 opens parallel to the flow path 4, and the lever 6 is connected to a vacuum actuator 9 via a rod 8.

The vacuum actuator 9 sucks the diaphragm 11 with the negative pressure of the negative pressure chamber 10 and pulls the rod 8.

The vacuum actuator 9 is connected to a negative pressure outlet 16 provided near the throttle valve 15 of the carburetor 14 via an electromagnetic three-way valve 12 and an orifice 13 .

The three-way valve 12 is connected in parallel to an accelerator switch 18, which is closed when the accelerator 17 is released, and a speed change switch 20, which is closed when the change lever 19 is selected for low-speed gear engagement, and connected to a power source.

Explain and explain the action.

When driving at high speed with the accelerator 1 and 7 selected and the change lever 19 set to the high speed gear, both the accelerator switch 18 and the gear change switch 20 are turned off, and the three-way valve 12 is opened to the atmosphere. Vacuum actuator 9
No negative pressure is applied to the valve, and the on-off valve 5 is open.

When the accelerator 17 is released to decelerate or to perform idling operation, the accelerator switch 18 is closed, and when the change lever 19 is set to low-speed gear engagement, such as the second gear of a four-speed transmission, the shift switch 20 is closed. closes.

In these cases, the three-way valve 12 communicates the vacuum actuator 9 with the negative pressure outlet 16, and the negative pressure near the throttle valve 15 in the intake path is transferred to the vacuum actuator 9.
This acts to close the on-off valve 5 and narrow the flow path 4.

During deceleration, idling operation, or low rotation, the throttle valve 15 is also closed or only slightly opened.
Inadequate intake air causes irregular combustion, but in response to this, the flow path 4 is restricted as described above to suppress the flow of exhaust gas and reduce the amount of exhaust gas.

Even if the speed change switch 20 is closed, when you want to accelerate suddenly, the accelerator 17 is wide open, so the negative pressure near the throttle valve 15 is small, and the vacuum actuator 9
, the on-off valve 5 is open and a large output is obtained.

Incidentally, the orifice 13 is configured to be able to adjust the flow of negative pressure.

As explained above, this invention provides an on-off valve that narrows the flow path in the exhaust pipe of a two-stroke engine, connects the on-off valve to a vacuum actuator, and connects the vacuum actuator to the carburetor via an electromagnetic three-way valve. Connect the three-way valve to the negative pressure outlet near the Throntle valve, and connect the three-way valve in parallel to the accelerator switch, which closes when the accelerator is released, and the speed change switch, which is linked to the change lever and closes when low-speed gears are engaged, so that either switch closes. When this occurs, the vacuum actuator and negative pressure outlet are communicated with each other using a three-way valve, and the on-off valve is closed to narrow the flow path, thereby limiting the amount of exhaust discharged during deceleration, idle link operation, and low speed range operation. can reduce the release of harmful components.

Moreover, at high speeds, the on-off valve opens and the flow path becomes larger.
Large output can be obtained.

Even at low speeds, when accelerating suddenly, there is little negative pressure near the throttle valve, which opens the on-off valve and provides high output.

In this way, it is possible to limit exhaust gases with less hindrance to driving.

Furthermore, when exhaust gas is restricted, exhaust noise is concomitantly reduced and the engine braking effect during deceleration is also improved.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view showing an embodiment of the present invention. 1...Engine, 3...Exhaust pipe, 4.
...Flow path, 5...Opening/closing valve, 9...
・Vacuum actuator, 12... Three-way valve,
14... Carburizer, 15... Throttle valve, 16... Negative pressure outlet, 17...
Accelerator, 18... Accelerator switch, 19.
・・・・・・Change lever, 20・・・Shift switch.

Claims (1)

[Scope of utility model registration request] An on-off valve that narrows the flow path is provided in the exhaust pipe of a two-stroke engine, and the on-off valve is connected to a vacuum actuator, and the vacuum actuator is connected to a negative pressure intake near the throttle valve of the electric appliance via an electromagnetic three-way valve. The three-way valve is connected to the outlet and connected in parallel to the accelerator switch, which closes when the accelerator is released, and the gear change switch, which is linked to the change lever and closes when low-speed gears are engaged.When either switch closes, the three-way valve closes the gear. An exhaust gas control device for a two-stroke engine, characterized in that a vacuum actuator and a negative pressure outlet are communicated with each other, and a flow path is narrowed by closing an on-off valve.