JPH0133649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine with controlled number of cylinders.

For multi-cylinder engines, the number of operating cylinders is increased or decreased depending on the operating condition. For example, for a 3-cylinder engine, only one cylinder is operated when idling or under light load, and at medium load of about 40 km/h. There are engines that control the number of cylinders, such as by operating with two cylinders and, when the load is higher, operating with all three cylinders, in order to maintain an optimum air supply ratio at all times, thereby improving fuel efficiency. In order to achieve the above technical concept in such a cylinder number controlled engine, a control valve is generally arranged in a part or all of the intake pipe of the intake manifold,
The valve is opened in accordance with the opening degree of a throttle valve.

However, in all of these, the opening degree of the control valve corresponds to the opening degree of the throttle valve, so especially in the early stages of opening the control valve, a shock may occur while the irregular combustion range is exceeded, resulting in poor ride quality. It had the disadvantage of damaging the

Additionally, in general, two-stroke multi-cylinder engines,
It is said that in order to improve the exhaust interference effect, it is sufficient to narrow down the collecting part of the exhaust manifold. but,
If the constriction is too narrow, outflow resistance will increase and back pressure will increase, resulting in poor gas exchange and a decrease in output. This phenomenon is particularly noticeable in engines with controlled number of cylinders.

In view of these problems, the present invention provides an engine with cylinder number control that can produce the best torque over the entire range of load fluctuations without impairing riding comfort. , a normally closed intake control valve is disposed in at least a part of the intake pipe of an intake manifold that supplies air-fuel mixture to each cylinder from one throttle valve, and a negative pressure actuator is linked to each intake control valve. ,
The pressure chambers of these negative pressure actuators are connected downstream of the intake control valves of the respective intake pipes through switching valves operated by the throttle valves, and when the throttle valves are smaller than a certain opening, the The pressure chamber of the pressure actuator is opened to the atmosphere, and when the throttle valve reaches a certain opening degree or more, the switching valve is operated to communicate the pressure chamber of the negative pressure actuator downstream of the intake control valve of the intake pipe. , thereby opening the intake control valve, further disposing a half-open exhaust control valve in the gathering part of the exhaust manifold, and linking the negative pressure actuator to the exhaust control valve, and opening the pressure chamber of the negative pressure actuator. is connected downstream of the intake control valve of one of the intake pipes, and the exhaust control valve is fully opened in synchronization with the opening operation of the intake control valve.

The present invention will be described below with reference to embodiments shown in the drawings. In each of the embodiments, the present invention is applied to a two-stroke three-cylinder engine.

As shown in Fig. 1, this engine has normally closed intake control valves in intake pipes _{2 1} , 2 ₂ , 2 ₃ of an intake manifold 2 that supply air-fuel mixture to each cylinder 1 ₁ , 1 ₂ , 1 ₃ . 3 ₁ , 3 ₂ , 3 ₃ are installed, and their control valves 3
₁ , 3 ₂ , 3 ₃ when the throttle valve 4 reaches a certain opening degree,
Independently of the throttle valve 4, the throttle valve 4 is sequentially opened fully open or close to fully open instantaneously, and furthermore, a half-open exhaust control valve 6 is disposed in the gathering part 5a of the exhaust manifold 5, and the control valve 6 is used as an intake control valve. The control valve is fully opened in synchronization with the opening operation of one of the control valves 3 ₁ , 3 ₂ , and 3 ₃ .

FIG. 2 shows the operating mechanism of the intake control valve ₃₃ and the exhaust control valve 6 in such an engine.
The control valve ₃₃ is connected to a negative pressure actuator 11 via a rod 10. The negative pressure actuator 11 connects its pressure chamber 12 to the outlet 14a of the electromagnetic switching valve 14 via a conduit 13, while the inlet 14b of the switching valve 14 is connected to the downstream side of the control valve ₃₃ in the intake pipe ₂₃ . is connected to. This switching valve 14 is
In addition to the above-mentioned ports 14a and 14b, an atmospheric port 14c
and in a non-excited state, closes the atmospheric port 14c and communicates the inlet 14b and the outlet 14a,
energized to close inlet 14b and close outlet 14
b and the atmosphere port 14c are communicated with each other. This electromagnetic switching valve 14 is energized by turning on the main switch 15 when starting the engine, and the second
The control valve ₃₃ is opened as shown in the figure. The electromagnetic switching valve 14 thus excited is turned off by the cam 16 which rotates together with the throttle valve 4, and the switch 17 is turned off, thereby demagnetizing the electromagnetic switching valve 14. In the figure, 16 is a trough on the cam surface, 16b is a peak on the cam surface, 18 is a roller that is in contact with the cam surface, 19 is a lever that supports the roller, and 20 is a portion that projects from the lever. This is the pushing piece for operating the switch. Further, in the electromagnetic switching valve 14, 14d is a valve body. Furthermore, in FIG. 2, a lever 21 is disposed at an appropriate location on the housing, one end of the lever is engaged with a pin 22 protruding from the rod 10 of the actuator 11, and the other end of the lever 21 is connected via the rod 23. It is connected to cam 16.

Further, in this engine, a negative pressure actuator 24 is attached, and the actuating lever 26 of the exhaust control valve 6 is engaged with the rod 25 of the negative pressure actuator 24. The intake control valve 3 at ₃ is communicated with the downstream side of ₃ .

The cylinder number control engine shown in FIG. 2 operates as follows. When the main switch 15 is turned on to start the engine, the electromagnetic switching valve 14 is energized, closing the inlet 14b and closing the outlet 14a.
and the atmospheric air port 14c. Therefore, the pressure chamber 12 of the negative pressure actuator 11 is communicated with the atmosphere, and the intake control valve ₃₃ is maintained in a closed state.
In this case, fuel is sent to another intake pipe (not shown), such as the intake pipe ₁₁ , and the engine is kept in an idling state. In this state, maximum negative pressure acts on the pressure chamber 27 of the negative pressure actuator 24, and the exhaust control valve 6 is maintained in a half-open state. Next, when the accelerator pedal is depressed, the throttle valve 4 is rotated counterclockwise to increase its opening degree. In such a state, fuel corresponding to the opening degree of the throttle valve 4 is transferred to the other cylinder 1 ₁ via the other intake pipe 2 _{2 .}
and into the cylinder 1 ₂ via the newly opened intake pipe 2 ₂ . When the throttle valve 5 is further rotated counterclockwise, the cam 16 is also rotated counterclockwise, and when the cam has rotated to a certain angle, the roller 18 touches the peak 16b of the cam 16. This causes the pushing piece 20 to be pushed up and the switch 17 to be disconnected. Therefore, the electromagnetic switching valve 14
is demagnetized, closes the atmospheric port 14c, and
The outlet 14a and the inlet 14b are communicated, that is, the pressure chamber 12 of the negative pressure actuator 11 is communicated with the downstream side of the control valve ₃₃ in the intake pipe ₂₃ , and the negative pressure actuator 11 is operated. As a result, control valve 3
₃ is opened, and fuel is also supplied to the illustrated cylinder ₁₃ . When fuel starts to be supplied to the cylinder 1 ₃ , the negative pressure downstream of the control valve 3 ₃ in the intake pipe 2 ₃ weakens.
Therefore, the biasing force of the spring 29 causes the exhaust control valve 6 to be fully opened.

In FIG. 3, a switch 30 detects when the intake control valve ₃₃ is opened, and the electromagnetic switching valve 31
A specific example is shown in which the downstream side of the intake control valve 3 ₃ in the intake pipe 2 ₃ and the pressure chamber 27 of the negative pressure actuator 24 are connected to each other by operating the pipe 32, thereby increasing the opening degree of the exhaust control valve 6. FIG. The embodiment shown in FIG. 4 is based on the switch 17 and the electromagnetic switching valve 14 in the cylinder number control engine shown in FIG.
The opening timing of the intake control valve ₃₃ and the opening expansion timing of the exhaust control valve 6 are synchronized. That is, in this embodiment, the operating lever 2 of the exhaust control valve 6
6 is engaged with the rod 25 of the negative pressure actuator 24, and the pressure chamber 27 of the negative pressure actuator 24 is connected to the outlet 14a of the electromagnetic switching valve 14 via a conduit 32.

Therefore, in this embodiment, the throttle valve 4 is opened to a certain degree, the switch 17 is cut off by the peak 16b of the cam 16, and the switching valve 14 is demagnetized to open the pressure chamber 12 of the negative pressure actuator 11. The intake pipe 2 ₃ is connected to the downstream side of the intake control valve 3 ₃ , thereby opening the intake control valve 3 ₃ . At the same time, since the pressure chamber 27 of the negative pressure actuator 24 is also communicated with the downstream side of the intake control valve 3 ₃ in the intake pipe 2 ₃ via the conduit 32, the opening degree of the exhaust control valve 6 is also expanded. In this embodiment, the electromagnetic switching valve 14
The operating signal is obtained by detecting the opening degree of the throttle valve 4, but there is no substantial difference from the principle diagram shown in FIG.

In such an engine with controlled number of cylinders according to the present invention, each intake control valve is instantaneously fully opened or almost fully opened, so shocks due to irregular combustion in the engine are prevented, the riding feeling is extremely good, and the exhaust manifold is An exhaust control valve is installed at the collecting part,
Since the opening degree of the control valve is expanded in accordance with the engine load, the maximum torque can always be obtained and the fuel efficiency is extremely high.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram showing an engine with cylinder number control according to the present invention, Fig. 2 is a conceptual diagram showing the operating mechanism of the intake control valve and exhaust control valve, and Fig. 3 is a conceptual diagram showing the cylinder number control engine according to the present invention. FIG. 4 is a principle diagram showing another operating mechanism of the engine, and FIG. 4 is a conceptual diagram showing an embodiment thereof. 1 ₁ , 1 ₂ , 1 ₃ ... cylinder, 2 ... intake manifold, 2 ₁ , 2 ₂ , 2 ₃ ... intake pipe, 3 ₁ , 3 ₂ , 3 ₃
...Intake control valve, 4...Throttle valve, 5...Exhaust manifold, 5a...Collection part,
6...Exhaust control unit, 11...Negative pressure actuator, 12...Pressure chamber, 14...Solenoid switching valve, 14
a...Outlet, 14b...Inlet, 14c...Atmospheric port, 14d...Valve body, 16...Cam, 16a...
Tanibe, 16b... Yamabe, 17... Switch, 24
... Negative pressure actuator, 27 ... Pressure chamber, 30
...Switch, 31...Switching valve, 32...Pipe line.

Claims (1)

[Claims] 1. A normally closed intake control valve is provided in at least a part of the intake pipe of an intake manifold that supplies air-fuel mixture to each cylinder from one throttle valve, and a negative pressure actuator is linked to each intake control valve, and , connecting the pressure chambers of these negative pressure actuators downstream of the intake control valves of the respective intake pipes via switching valves operated by the throttle valves,
When the opening of the throttle valve is smaller than a certain opening, the pressure chamber of the negative pressure actuator is opened to the atmosphere, and when the opening of the throttle valve exceeds a certain opening, the switching valve is operated to reduce the pressure of the negative pressure actuator. A chamber is communicated downstream of the intake control valve of the intake pipe, thereby opening the intake control valve, and further, a half-open exhaust control valve is disposed at a gathering part of the exhaust manifold, and a negative pressure is applied to the exhaust control valve. The actuators are linked together, and the pressure chamber of the negative pressure actuator is connected downstream of the intake control valve of one of the intake pipes, and the exhaust control valve is fully opened in synchronization with the opening operation of the intake control valve. An engine with a controlled number of cylinders.