JPS63212717A - Multiple throttle type internal combustion engine - Google Patents

Abstract

PURPOSE:To improve stability in a low-speed low-load range by communicating a premix fuel-air supply passage with the downstream side of each main intake throttle valve, and providing an auxiliary fuel supply device in the premix fuel-air supply passage. CONSTITUTION:A main intake throttle valve 16 and a main fuel injection valve 17 are disposed in each intake pipe 13. A premix fuel-air supply passage 19 is communicated with the downstream side of the main intake throttle valve 16. An auxiliary fuel injection valve 22 is disposed in the premix fuel-air supply passage 19. In a low-speed low-load operating range, premix fuel-air is generated from the auxiliary fuel injection valve 22 to be supplied to each cylinder. Thus the stability in the low-speed low-load region can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a multiple throttle internal combustion engine having intake throttle valves connected to each other in each intake passage of each cylinder. Regarding structure.

<Prior art> An example of this type of multiple throttle internal combustion engine is the one shown in Figure 6 (Toyota Technology, 1933).
(See June 9th, Vol. 34, No. 1, pp. 41-47).

That is, a multiple throttle internal combustion engine includes an intake throttle valve 3 in each intake passage 2 connected to each cylinder 1 of the multiple cylinder internal combustion engine, an electronically controlled fuel injection valve 4 for each cylinder, This is generally used in motorsports racing and rally engines.

The reason for this is that, as shown in the figure, the volume between the intake throttle valve and the intake valve 5 downstream of the intake throttle valve can be reduced, so that when the intake throttle valve 3 is opened, the time response of the intake air entering each cylinder l is This is because there is little delay and a very fast torque increase can be obtained.

In addition, the fuel supply system of a multiple throttle internal combustion engine is
used a carburetor, but recently, as mentioned above, electronically controlled fuel injection valves 4 have been widely used.

Here, an example is shown in which the fuel injection valve 4 is disposed on the upstream side of the intake throttle valve 3, but fuel injection valves disposed on the downstream side of the intake throttle valve 3 are also known.

<Problems to be solved by the invention> However, such conventional multiple throttle internal combustion engines place emphasis on engine performance at high speeds and high loads, and are not suitable for internal combustion engines for practical vehicles running on public roads. As a result, it lacked stability and drivability at low speeds and low loads, including during idling, and did not meet the requirements of fuel economy and exhaust regulations.

The present invention has been made by focusing on the problems of the conventional technology, and improves stability in the low speed and low load range while maintaining engine performance in the high speed and high load range of a multiple throttle internal combustion engine. The purpose of the present invention is to provide a multiple throttle internal combustion engine that improves drivability and meets the requirements of fuel economy and exhaust regulations.

<Means for solving the problem> For this reason, a main fuel supply device is provided near the intake port provided for each cylinder, and a main fuel supply device is provided for each cylinder to control the amount of intake air according to the engine load. While the intake throttle valves are connected to each other, a premixture supply passage communicating with the downstream side of each main intake throttle valve is provided, and an auxiliary fuel supply device is provided in the premixture supply passage.

Effect> Since the above configuration is adopted, the premixture of fuel and intake air supplied from the auxiliary fuel supply device is supplied to each cylinder via the premixture supply passage.

As a result, stability and drivability in the low-speed and low-load range, which were shortcomings of conventional multiple-throttle internal combustion engines, are improved, and compatibility with fuel efficiency and exhaust emission regulations is achieved.

On the other hand, in a high speed/high load region of the engine, a mixture of fuel supplied from the main fuel supply device and intake air is supplied to each cylinder. Therefore, the high engine performance of the multiple throttle internal combustion engine is maintained as in the conventional case.

<Example> An embodiment of the present invention is shown in FIGS. 1 to 4.

FIG. 1 shows a four-cylinder internal combustion engine 10, and the intake ports 11 of each cylinder #1 to #4 of the internal combustion engine 10 are connected to a collector 12 connected to an air cleaner (not shown), an intake pipe 13, and a bellows pipe 14. It's communicating. Each intake pipe 13 is provided with a main intake throttle valve 16 that rotates in conjunction with each other via a connecting portion 15, and a main fuel injection valve as a main fuel supply device is provided downstream of the main intake throttle valve 16. 17 are provided. The main fuel injection valve 17 is designed to operate in conjunction with the opening operation of the main intake throttle valve 16. Note that since the main intake throttle valve 16 is not provided in the collector 12, the collector 12 can be made of synthetic resin, contributing to weight reduction.

A downstream side of the main intake throttle valve 16 of the intake pipe 13 communicates with the collector 12 via a communication passage 18 and a single premix supply passage 19 . In this embodiment, the premixture supply passage 19 is provided with a sub-intake throttle valve 21 that is opened and closed by a throttle drum 20 connected to an accelerator pedal (not shown), and a sub-intake throttle valve 21 is provided upstream of the sub-intake throttle valve 21. A sub-fuel injection valve 22 as a fuel supply device and an ultrasonic vibrator 23 for atomizing the injected fuel are provided downstream of the sub-fuel injection valve 22. The auxiliary fuel injection valve 22 and the ultrasonic vibrator 23 operate in conjunction with the opening operation of the auxiliary intake throttle valve 21.

Note that the auxiliary intake throttle valve 21 may not be provided, and the auxiliary fuel injection valve 22 may be configured by a well-known carburetor.

Further, a bypass passage 25 is formed in the premixture supply passage 19, bypassing the auxiliary intake throttle valve 21, and through which the mixture for setting the idle rotational speed passes. The bypass passage 25 includes an idle speed control valve (
ISO valve) 24 valves are installed, TSC valve 2
On the upstream side of 4, there is a provision passage 26 and a canister passage 2.
7 are merging. Note that the bypass passage 25 for setting the idle rotational speed is provided only in the premixture supply passage 19.

Here, with reference to FIG. 2, the valve shaft 2 of the auxiliary intake throttle valve 21
The connecting portion 28 between 1a and the valve shaft 16a of the main intake throttle valve 16 will be explained.

The main intake throttle valve 16 and the auxiliary intake throttle valve 21 are connected to the valve shaft 1
In the initial state where 6a and 21a are not rotated, they both maintain a closed state.

A connecting member 29 having a convex piece 29a extending θ in the direction of the valve shaft is fixed to the end of the valve shaft 21a of the auxiliary intake throttle valve 21. A connecting member 30 having a housing portion 30a that rotatably stores the convex piece 29a by a predetermined angle is fixed to the portion.

Here, the connecting members 29 and 30 are configured as interlocking means for the auxiliary intake throttle valve 21 and the main intake throttle valve 16.

With this configuration, when the rotation angle of the throttle drum 20 is within a predetermined angle range corresponding to the storage portion 30a (low speed/low load area), only the sub-intake throttle valve 21 is rotated and opened. On the other hand, when the rotation angle of the throttle drum 20 exceeds the predetermined angle range (high speed/high load region), the main intake throttle valve 16 is closed to the sub intake throttle valve 21. The valve opens in conjunction with the rotation of the cylinder, and intake air is guided to each cylinder independently. Note that by appropriately setting the initial mounting angles of the main intake throttle valve 16 and the auxiliary intake throttle valve 21 and the connecting member 30, interlocking characteristics that exhibit desired engine performance can be obtained.

Next, this effect will be explained.

In low-speed/low-load operating ranges, including during idling, a premixture is generated by the auxiliary fuel injection valve 22 and the ultrasonic vibrator 23, and is communicated with the premixture supply passage 19 via the auxiliary intake throttle valve 21. It is supplied from the passage 18 to each cylinder #l to #4.

Here, when the engine is running at idle, the air-fuel mixture.

Blow-by gas and canister gas pass through the bypass passage 25
is guided through the ISC pulp 24 of each cylinder #1 to #4.
supplied to For this reason, it has been difficult to create an air-fuel mixture in conventional multiple throttle internal combustion engines.

Since the distribution of blow-by gas and canister gas between the cylinders can be improved, the effective work among the cylinders can be made uniform, and stable idling can be performed.

When the load increases slightly from the idling state, the throttle drum 20 rotates, and the auxiliary intake throttle valve 21 opens accordingly. Then, the premixture with good air-fuel mixture properties is supplied to each cylinder #1 to #4. At this time, the main intake throttle valve 16 and the main fuel injection valve 17 are in the closed state, so
Fuel is supplied to each cylinder #1 to #4 only from the premixture supply passage 19.

When the load further increases from this state (including during acceleration), the throttle drum 20 rotates further, the valve shaft 21a of the auxiliary intake throttle valve 21 rotates, and the auxiliary intake throttle valve 21 becomes fully open or close to fully open. The convex piece 29a formed on the connecting member 29 fixed at the end of the valve shaft 21a comes into contact with the connecting member 30 fixed at the end of the valve shaft 16a of the main intake throttle valve 16, and the main intake throttle valve 16 is opened. is started.

Then, in conjunction with the opening of the main intake throttle valve 16, the driving of the main fuel injection valve 17 is started, and the air-fuel mixture is injected into each cylinder #1 to #4.
supplied to

That is, the main intake throttle valve 16 and the auxiliary intake throttle valve 21 have an overlap area (see FIG. 5), and the main fuel injection valve 17 and the auxiliary fuel injection valve 22 that are linked to these also have an overlap area to some extent. have. Here, the injection amounts of both fuel injection valves 17 and 22 are controlled to increase or decrease, respectively, so that there is no difference in the mixture ratio of the air-fuel mixture supplied to each cylinder.

For example, when setting the air-fuel ratio commensurate with the amount of intake air by feedback control using the output of an oxygen sensor (not shown) installed in the exhaust pipe 31, the total amount of injection should be the amount commensurate with the amount of intake air. , both fuel injection valves 17.
To smoothly increase and decrease the fuel injection amount between 22 and 22. Note that the intake air amount is detected from the rotation angle from a throttle sensor (not shown) provided on the throttle drum 20. In this case, the throttle sensor is connected to both fuel injectors 17.
A two-track type having two sensor sections corresponding to 22 is suitable for maintaining accuracy.

Furthermore, when the load increases and the main intake throttle valve 16 becomes fully open, the auxiliary intake throttle valve 21 closes and each cylinder #1 to # Air-fuel mixture is supplied to each of the four.

As described above, in the conventional multiple throttle internal combustion engine, the premixture supply passage 19. A premixture supply system consisting of a sub-intake throttle valve 21, etc. is added, and the opening degree of the sub-intake throttle valve 21 is controlled to control the air-fuel mixture properties from the premixture supply system during low speed and low load regions including idling. By supplying a good premixture, smooth operation without surge or vibration is possible at low speeds and low loads, and stability at low speeds and low loads, which was a drawback of multiple throttle internal combustion engines, has been improved. sex,
In addition to improving drivability, it is possible to achieve compliance with fuel efficiency and emission regulation conditions.

On the other hand, during transient operation or high-speed/high-load operation, the main intake throttle valve 16 rotates in conjunction with the rotation of the auxiliary intake throttle valve 21, supplying air-fuel mixture to each cylinder as before, so the intake The air tracking performance is improved, and the high engine performance that is characteristic of multiple throttle internal combustion engines can be demonstrated.

In addition, especially during sudden acceleration, the main intake throttle valve 16 suddenly engages from the state where the premixture is filled in the intake port, and fuel is injected from the main fuel injection valve 17 to perform acceleration. Compared to a type internal combustion engine where the fuel is suddenly injected from a state where there is no pre-mixture at all, lean misfire (fuel is supplied as a liquid without vaporizing even though the intake air increases) As a result, smooth acceleration can be achieved with less occurrence of the phenomenon in which the air-fuel mixture temporarily becomes diluted and combustion stops.

In the embodiment, the main intake throttle valve 16 is moved slowly and interlocked with the rotation of the auxiliary intake throttle valve 21 so that it opens when the auxiliary intake throttle valve 21 reaches a predetermined opening degree or more. However,
It may be possible to open the valves at the same time without delaying the operation. In this case, the auxiliary intake throttle valve 21 may open at low speeds and low loads.
In order to obtain the desired engine performance, well-known means (for example, a variable gear ratio device) are taken such as keeping the opening increase rate of the main intake throttle valve 16 low relative to the opening increase rate of the main intake throttle valve 16, and increasing it at high speeds and high loads. Create interlocking characteristics that allow

Further, a connecting member 29 fixes the main intake throttle valve 16 to these valve shafts 16a, 21a to allow rotation of the auxiliary intake throttle valve 21;
30, but they may be rotated in conjunction with each other via a control cable or the like.

Further, a sensor for detecting the opening of the sub-intake throttle valve 21 and an actuator for driving the main intake throttle valve 16 are provided, and the drive actuator for the main intake throttle valve 16 is controlled in accordance with the opening and closing of the sub-intake throttle valve 21. You can also do this.

<Effects of the Invention> As described above, according to the present invention, main fuel injection valves are provided in the vicinity of the intake port provided for each cylinder, and intake air is injected into each cylinder according to the engine load. Main intake throttle valves for controlling the amount of air are connected to each other, and a premixture supply passage communicating with the downstream side of each main intake throttle valve is provided, and an auxiliary fuel supply device is provided in the premixture supply passage. Therefore, while maintaining the high engine operating performance in the high speed and high load range of the conventional multiple throttle internal combustion engine, it has improved stability and drivability in the low speed and low load range, and has also improved fuel efficiency and emission regulation requirements. compatibility can be achieved.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is a view of the main parts of the same as shown above, FIG. 3 is a cross-sectional view of the same, FIG. 4 is a cross-sectional view of the same, and FIG. The same intake throttle valve opening characteristic diagram as above and FIG. 6 are overall configuration diagrams showing a conventional multiple throttle type internal combustion engine. 11...Intake port) 16...Main intake throttle valve 1
7...Main fuel injection valve 19...Premixture supply passage 22...Auxiliary fuel injection valve #1 to #4...Each cylinder Patent applicant Nissan Motor Co., Ltd. Hitachi, Ltd. Agent Patent attorney Tomijio Sasashima Accessories ν Petatsu Rest Mouth

Claims (1)

[Claims] A main fuel supply device is provided near the intake port provided for each cylinder, and each cylinder is provided with main intake throttle valves connected to each other to control the amount of intake air according to the engine load. A multiple throttle internal combustion engine, characterized in that a premixture supply passage communicating with the downstream side of each of the main intake throttle valves is provided, and an auxiliary fuel supply device is provided in the premixture supply passage. Throttle type internal combustion engine.