JPH0244021Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of the Invention The present invention relates to an intake device for improving the intake inertia effect in a multi-cylinder internal combustion engine, and particularly to an intake device for uniformizing the amount of intake air to each cylinder.

Background of the invention In a multi-cylinder internal combustion engine, a partition wall is provided that divides the inside of the intake passage into two parts in the longitudinal direction, and the intake passages are joined on the upstream side, and each passage divided by the partition wall is divided into two parts in which the intake order is not adjacent to each other. one cylinder group and a second cylinder group (for example, in a 6-cylinder engine, the intake order is #1-#5-#3-#6-#2-
If each cylinder in #4 is in order, #1, #2,
Intake systems connected to cylinders #3 and cylinders #4, #5, and #6 have been known for a long time.
Attempts have been made to improve the volumetric efficiency (the ratio of the amount of intake air to the stroke volume of the cylinder) by providing a communication hole in the partition wall of such an intake system and controlling the opening and closing of the communication hole according to the operating conditions of the engine. However, if the intake throttle valve is provided upstream of the confluence of the two divided passages, the volume downstream of the throttle valve will increase and the responsiveness of load control will deteriorate. On the other hand, if an intake throttle valve is provided downstream of the communication hole between the two passages, it goes without saying that each passage requires an intake throttle valve.
It is difficult to equalize the amount of air passing through both valves due to the processing accuracy, positioning accuracy, etc. of the valves. Therefore, normally, the shaft on which the throttle valve is attached is divided into two parts, and an adjustment mechanism is installed to adjust the relative position of both valves so that the pressure downstream of the valve is equalized, especially when the throttle valve opening is small. There is.

Purpose of the invention A partition wall is provided that divides the intake passage into two parts in the longitudinal direction, and the partition walls are merged on the upstream side of the partition wall. In a multi-cylinder internal combustion engine connected to cylinder groups, the intake pressures of the divided passages are made equal to each other, thereby making the amount of intake air to each cylinder uniform.

Structure of the invention In the multi-cylinder internal combustion engine as described above, a communication hole is provided in the partition wall to communicate each passage, and a control valve is provided that opens the communication hole in a light or medium load range of the engine and closes it in a high load range. Further, an intake throttle valve is attached to each of the passages upstream of the control valve.

Embodiment In the figure, 1 is the main body of a six-cylinder engine, 2 is an intake manifold, and 3 is an exhaust manifold. The intake manifold 2 is grouped into a first cylinder group 2a and a second cylinder group 2b, which are not adjacent in intake order. That is, the intake order of each cylinder is #1
-#5-#3-#6-#2-#4, so that the intake order is not adjacent, #1, #2, #3 are in the first cylinder group 2a, #4, #5, # 6 is the second cylinder group 2b
Each is summarized in The intake passage 4 is divided into two in the longitudinal direction by a partition wall 5, which merge at a merging portion 6 on the upstream side, and are further connected to an air cleaner 7 on the upstream side. Reference numeral 8 denotes an atmospheric air intake port of the air cleaner 7. 2 by partition wall 5
The divided intake passages 4a and 4b are connected to the first cylinder group 2a and the second cylinder group 2b, respectively, at a gathering portion 15. The partition wall 5 is provided with a communication hole 9 that communicates between the divided intake passages 4a and 4b.
This communication hole 9 is controlled to open and close by a diaphragm type control valve 10. The diaphragm control valve 10 is
It is connected to a solenoid valve 12 that is driven by a control signal from a control device 11, and is switched so that negative pressure from a negative pressure source 13 such as a vacuum pump or atmospheric pressure acts, and the communication hole is opened accordingly. Open and close 9. Intake throttle valves 14a and 14b are installed in each intake passage 4a and 4b upstream of the control valve 10 and downstream of the merging portion 6, respectively.

Note that when the cross section of the two intake passages 4a and 4b divided by the partition wall 5 is circular, the throttle valve 1
4a and 14b can be circular butterfly valves as shown. In addition, the intake passages 4a, 4
If the inner wall surface divided by the partition wall 5 of b is not cylindrical, only the portion where the throttle valves 14a and 14b are provided may have a circular cross section.

When the engine is operating under light or medium load, negative pressure is transmitted to the diaphragm control valve 10 and the communication hole 9 is opened. As a result, the throttle valve 1
The pressures in the two divided intake passages 4a and 4b downstream of 4a and 14b are equal to each other, so that the pressure in the first cylinder group 2
a. The amount of air distributed to the second cylinder group 2b becomes equal,
The amount of air taken into each cylinder can be made uniform. In a high load range, atmospheric pressure is introduced into the diaphragm control valve 10 and the communication hole 9 is closed. This increases the intake inertia effect in the high load range and improves the volumetric efficiency. Note that the engine load is caused by the intake pipe negative pressure downstream of the throttle valves 14a and 14b or by the throttle valve 14.
It is detected by detecting the opening degrees of a and 14b and is input to the control device 11.

Effects of the invention The intake inertia effect is enhanced in the high load range of the engine, and the amount of air can be made uniform in the light and medium load range, where the intake air volume distribution to each cylinder tends to be uneven. Further, there is no need for a means for adjusting the relative positions of both throttle valves 14a, 14b, and the device can be simplified.

[Brief explanation of the drawing]

The figure schematically shows an embodiment of the intake system for a multi-cylinder internal combustion engine according to the present invention. 2...Intake manifold, 4...Intake passage, 5...
...Partition wall, 9...Communication hole, 10...Control valve, 14
a, 14b... Throttle valve.

Claims (1)

[Scope of utility model registration request] A partition wall 5 is provided that divides the inside of the intake passage 4 into two in the longitudinal direction, and the partition wall 5 is made to merge on the upstream side thereof, and each passage 4a, 4b divided by the partition wall is connected to a first cylinder group 2a whose intake order is not adjacent to each other. A control valve 10 is provided which is connected to each of the second cylinder groups 2b and has a communication hole 9 in the partition wall that communicates each passage, and which opens the communication hole in a light or medium load range of the engine and closes it in a high load. , furthermore, an intake throttle valve 1 is provided in each of the passages 4a and 4b upstream of the control valve.
An intake system for a multi-cylinder internal combustion engine, characterized in that 4a and 14b are attached.