JPS6022179B2 - cylinder number control engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder number control engine that suspends operation of some cylinders during light loads.

Primarily in multi-cylinder engines for automobiles, a cylinder number control engine has been proposed that improves fuel efficiency by cutting fuel supply to some cylinders under light loads and operating only on the remaining cylinders. .

Generally, the fuel efficiency of an engine tends to improve as the engine is operated under a higher load.

Therefore, if the operation of some cylinders is stopped when full output is not required, the load on the remaining operating cylinders will increase relatively, which will result in good fuel efficiency without sacrificing performance. It becomes possible to drive.

The above-mentioned cylinder number control engine was devised based on this technical idea, and the operation of some cylinders is suspended during light loads when there is enough room in the total engine output.

By the way, in order to further improve the fuel efficiency under light load conditions with this cylinder number control engine, it is possible to increase the engine compression ratio or install a turbocharger that is driven by exhaust pressure to perform supercharging. It can be said that it is very effective.

However, when using this turbocharger for weekly wages, the problem is engine knocking, so
Usually, a type of relief valve called a wastegate valve is installed upstream of the exhaust turbine, and this allows part of the exhaust gas to bypass the exhaust turbine and escape, especially when the exhaust flow rate increases, thereby suppressing supercharging appropriately. This prevents knocking.

In particular, if knocking is a problem, countermeasures such as relatively lowering the compression ratio must be taken, and even though a turbocharger is installed, the effect of improving fuel efficiency may not be as great as expected. It was done.

Therefore, the present invention utilizes the characteristics of cylinder number control to drive the turbocharger with the exhaust pressure of the cylinder on the idle side and supercharge the intake air of the cylinder on the idle side, thereby preventing knocking and achieving a sufficient weekly pay effect. The object of the present invention is to provide a cylinder number controlled engine that achieves the following.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, an engine main body 1 is composed of a six-cylinder engine in a V-type arrangement, and cylinders #2, #4, and #6 are a cylinder group that continues to operate at all times, whereas #1, #3, and 5 cylinders indicate a group of cylinders whose operation is suspended due to the supply of fuel and air being cut off during light loads.

The intake passages 2a and 2b are provided independently from each other, and similarly the exhaust passages 3a and 3b are also provided independently from each other.

Throttle valves 4a and 4 are provided in the intake passages 2a and 2b, respectively.
Of these, the stop valve 4b is forcibly fully closed during partial cylinder operation.

Reference numeral 4 denotes an airflow meter that measures the amount of intake air in the intake passages 2a and 2b, and fuel injection valves FI to F6 are installed on the intake boats connected to each cylinder #1 to #6', respectively, and a control circuit (not shown) is installed. Fuel is injected and supplied based on the signal from.

A recirculation passage 5 is provided by short-circuiting the intake passage 2b and exhaust passage 3b on the side of the deactivated cylinder, and a recirculation valve 6 that opens only during partial cylinder operation is interposed in this passage 5, and the operation is suspended during this partial cylinder operation. Exhaust air is circulated and sucked into cylinders #1, #3, and #5 to prevent engine pumping loss. and,
This cylinder on the idle side is equipped with a turbocharger '0,
An exhaust turbine 8 installed in the exhaust passage 3b drives a compressor 9 installed in the intake passage 2b.

Next, the compression ratios of the active cylinders #2, #4, and #6 are set higher than those of the idle cylinders #1, #3, and #5, which greatly improves fuel efficiency, especially during light-load operation. There is.

In the above configuration, when the engine is in a medium or high load state, fuel is supplied from the fuel injection valves FI to F6 of all cylinders by a signal from a control circuit (not shown), and at the same time, the throttle valve 4b on the idle side is also supplied. It operates in proportion to the accelerator pedal and operates on all cylinders.

In this case, the active cylinders #2, #4, and #6 are limited in good fuel efficiency and output due to high compression, while the idle cylinders #1, #3, and #5 are also turbocharged, although their compression ratios are not high. The supercharging effect increases the air-fuel mixture filling efficiency, suppressing the occurrence of knocking and producing high output with the same good fuel.

Since the turbocharger 10 is driven by the exhaust pressure of the idle cylinders #1, #3, and #5, the drive is stopped during partial cylinder operation, so the supercharging rate is set in advance for the high speed rotation range. By doing so, proper weekly intake air intake can be achieved without the need for a special waste gate valve.

On the other hand, in a normal engine (or when the exhaust turbine 8 is installed in the exhaust gas flow path), the weekly rate at low and medium speeds must be taken into consideration, so at high speeds, excess air is inevitably generated. In order to avoid the phenomenon of pumping in water, a waste gate valve was required.

Next, in the light engine load range, a control circuit (not shown) cuts off the fuel supply to cylinders #1, #3, and #5, and at the same time, the throttle valve 4b fully closes to cut off the air supply. Therefore, only cylinders #2, #4, and #6 operate to perform partial cylinder operation.

0 The load on the active cylinder increases relatively, and since the compression ratio is high, operation is performed with very good fuel efficiency.

On the other hand, at this time, in the cylinder on the idle side, the recirculation valve 6 of the recirculation passage 5
is fully opened and the exhaust gas is circulated to the intake passage 2b downstream of the throttle valve 4b, so no pumping loss occurs and the output performance of the operating cylinder does not deteriorate.

Note that in this state, almost no exhaust gas flows to the turbocharger 10, so the turbocharger 10 is not driven, and of course no exhaust loss is caused.

The embodiment shown in Fig. 2 is an example in which the present invention is applied to an in-line 6-cylinder engine, but in this case, cylinders #1 to #3 stop operating during light loads, and cylinders #4 to #6 always operate. Everything is the same as the previous embodiment except that it continues.

Therefore, the same parts are given the same reference numerals and the description thereof will be omitted.

As is clear from the above explanation, according to the present invention, since the turbocharger is provided on the side of the idle cylinder while the compression ratio on the side of the active cylinder is increased, fuel efficiency can be improved under light load conditions. At the same time, it is possible to improve fuel efficiency and output performance while preventing knocking under high loads.

Further, a waste gate valve as a control device for the turbocharger is not required, and the structure can be simplified.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of the first and second embodiments of the present invention, respectively. 1...Engine body, 2a, 2b...Intake passage, 3
a, 3b...' Exhaust passage, 4a, 4b... Throttle valve 6... Reflux valve, 8... Exhaust turbine, 9
... Combretusa, 10...Turbo charger. Figure 1 Figure 2

Claims (1)

[Claims] 1 A cylinder that is equipped with a cylinder to which the supply of fuel and air is cut off in a light engine load range, a cylinder to which fuel and air are constantly supplied, and an intake passage and an exhaust passage that are independent of each other corresponding to these cylinders. In a numerically controlled engine, the compression ratio of the normally active cylinder is set higher than that of the inactive cylinder, while a turbocharger is provided to supercharge the intake air driven by the exhaust pressure of the inactive cylinder. Features a cylinder number control engine.