JPS5834276Y2 - Intake pipe structure of engine with cylinder number control - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake pipe structure for a cylinder number control engine equipped with a fuel injection device.

This type of cylinder number control engine is an engine that injects fuel into the golden cylinders to operate them when the load is heavy, and injects fuel to some cylinders when the load is light and stops the other cylinders. Although this method is extremely effective in terms of improving fuel efficiency, it has the following problems.

In other words, a conventional general cylinder number control engine divides a plurality of cylinders 4/-1 to +6 into two groups, A and B, as shown in FIG. has been suspended.

However, if, for example, the group B disposed downstream of the collecting section 8 (collector section) of the intake pipe I is configured to be inactive, the fuel simultaneously injected into each cylinder of the operating group A on the upstream side will be・Since the intake valves II to ■3 of the cylinders were opened in the past, the accumulated fuel remained near the intake ports PP1 to P3, so if the intake valves 14 to ■6 of each cylinder in the idle group B opened during this period, the accumulated fuel may be drawn into each cylinder #4-4P6 through the intake ports P4-P6 of the pause group B.

Therefore, part of this inhaled fuel is transferred to the idle cylinder 41=4
~J/I-6 is not combusted and is emitted, or is combusted at an excessively low air-fuel ratio, leading to an increase in hydrocarbons in the exhaust and deterioration of fuel efficiency. There was a risk of increased wear on the cylinder wall due to the booster port and carbon adhesion, and furthermore, catalyst burnout due to an abnormal oxidation reaction in the catalyst due to the exhaust of end-combustion gas.

In this case, it is considered that an opening/closing valve is installed in the cylinder station to separate both groups as shown in the figure, and by closing the opening valve, it is possible to prevent fuel from going around to the idle group B.
The pumping loss that should be kept in the idle capacity cylinders #4 to #6 becomes a problem, causing a decrease in output, which is not desirable.

1. Contrary to the above, if the number of cylinders is controlled so that group A on the upstream side of the collector section 8 is stopped and group B on the downstream side is operated from the viewpoint of reducing pumping loss, the above-mentioned partition is provided. Since this does not hold true, this will be abolished, but in that case, the circulation of fuel to the idle cylinders #1 to #3 will be done against the flow of intake air, so the circulation will be reduced, but this is still sufficient. isn't it.

Therefore, the throttle plate 9 as shown in Figure 2 is arranged at the location shown in Figure 1 to satisfy the prevention of fuel circulation, but the throttle plate 9 increases the suction resistance and reduces the output. In addition, when all cylinders are operated, there is a difference in the amount of intake air between upstream group A and downstream group B, and the air distribution between them becomes uneven, making it impossible to obtain an appropriate air-fuel ratio, resulting in lower emissions,
This results in deterioration of fuel efficiency and drivability.

The present invention was devised in view of the above, and its purpose is to change the inner diameter of the collector section from the downstream side to the upstream side in the cylinder number control engine in which the latter upstream group in the above example is deactivated. By making the cylinder larger in comparison, it suppresses the increase in intake resistance, reliably prevents fuel from flowing into the idle cylinders, and further improves fuel efficiency without deteriorating exhaust efficiency, fuel efficiency, or drivability. An object of the present invention is to provide an intake pipe structure for an engine that can control the number of cylinders.

FIG. 3 is a schematic configuration diagram of a cylinder number control engine 10 having the structure of the present invention, exemplified by six cylinders, and 11 is a block diagram of each cylinder #1.
An intake pipe consisting of branch parts M1 to M6 communicating with ~l and a large-diameter collector part 12, C is a face group consisting of cylinders +1 to #3 disposed upstream of the intake pipe 11 and collector part 12. , D are cylinders 44 to #6 arranged on the downstream side
This is an operating group consisting of:

13 is a throttle valve, 14 is an exhaust pipe, and cylinder 4/-1
The fuel injection valves disposed upstream of the intake ports #6 to #6 are not shown.

In this example, as shown in the cross-sectional shape taken along the line IV'-IV in FIG.
5, and the inner diameter DI of the upstream side 12A of the collector section is smaller than the inner diameter D2 of the downstream side 12B.

According to this configuration, the collector section 12 is attached to the step section 15.
Since the downstream side is expanded, when all cylinders are in operation, the intake air guided to the intake pipe 11 by the negative pressure generated in each cylinder is
Since the flow resistance at the stepped portion 15 when flowing from the upstream collector portion 12A to the downstream collector portion 12B is small,
The inertia of the air causes it to flow into the downstream collector section 12B, so that it is evenly distributed to each cylinder.

In addition, when some cylinders are in operation, the diameter of the collector section 12 is reduced on the upstream side at the stepped section 15, so when air moves upstream, it is subjected to flow resistance due to the throttle toward the stepped section 15, so that the upstream side There is no word that goes around.

In short, the air distribution of intake air to each cylinder is always good, and the air-fuel ratio in each cylinder can be maintained uniformly. It is possible to prevent the 7th
As shown in the figure, exhaust emissions, fuel efficiency, and drivability can be improved.

In the figure, N indicates a normal six-cylinder engine without cylinder number control, P indicates a conventional cylinder number controlled engine, and Q indicates a cylinder number controlled engine of the present invention.

Here, baboon S (-8
If t/S 2 ) is increased, the circulation of fuel can be reduced, but if it is too large, it will be disadvantageous in terms of air distribution, etc.

The present inventor measured the above area ratio S and various performances regarding fuel consumption, hydrocarbon content, engine output, and suction resistance, and the results were as shown in Figure 5. It has been found that good results can be obtained by setting S in the range from 15 to the shadow.

Note that similar results were obtained when the cross-sectional shape of the collector portion 12 was formed into a rectangular shape as shown in FIG.

In summary, the intake pipe structure of the present invention configures an engine with cylinder number control by arranging a dormant cylinder on the upstream side of the intake pipe and an active cylinder on the downstream side, and also increases the opening area of the intake pipe collector section from the upstream side. Although it has a simple configuration in which the intake air is oriented toward the downstream side, it does not increase the intake resistance of the intake air. Therefore, it makes the air distribution to each cylinder uniform, the air-fuel ratio is uniform, and the operating cylinder This prevents fuel from flowing into the idle cylinders, reducing emissions,
It has great practical effects, such as improving fuel efficiency and drivability.

[Brief explanation of the drawing]

Figure 1 is a sales channel configuration diagram of a conventional engine with controlled number of cylinders.
The figure is a partial sectional view, FIG. 3 is a schematic configuration diagram of a cylinder number control engine with the structure of the present invention, and FIG. 4 is a partial cross-sectional view of FIG.
A cross-sectional view taken along the line IV, Figure 5 A is a diagram showing various performances relative to the area ratio, Figure 6 is a diagram similar to Figure 4 showing a modified example, and Figure 1 A5 is a diagram showing various performances as a function of vehicle speed. FIG. -II-1 to 4F6...Cylinder, 10...Multi-cylinder cylinder number control engine, 11...Intake pipe, 12...Collector part, 1
2A... Upstream collector section, 12B... Downstream collector section,

Claims (2)

[Scope of utility model registration request] (1) It is equipped with a plurality of cylinders and a fuel injection device that supplies fuel to the cylinders, and when the load is light, the fuel supply to the cylinder group connected to the upstream collector part of the intake pipe is stopped to make the cylinders inactive;
In a cylinder number control engine in which a group of cylinders connected to a downstream collector section on the downstream side of the intake pipe is an active cylinder,
An intake pipe structure for an engine with a controlled number of cylinders, characterized in that an opening area of a downstream collector section of the intake pipe is set to be smaller than an opening area of an upstream collector section of the intake pipe. (2) The intake pipe of the cylinder number controlled engine according to claim 1, wherein the ratio of the opening area of the upstream collector section to the opening area of the downstream collector section is set to 1,154/s. structure.