KR960012380B1 - Variable intake system for i.c. engine - Google Patents

Abstract

None.

Description

Variable intake of internal combustion engine

1 is a front view of an engine showing an embodiment of the present invention.

2 is a cross-sectional view of the intake mani holder of the present invention.

3 is a plan view from above of the lower block of the invention;

4 is a plan view from above of the intermediate block of the invention;

5 is a plan view from below of the upper block of the invention;

6 is a side view of the upper block of the present invention.

7 is a front view of an engine showing a conventional example.

* Explanation of symbols for main parts of the drawings

6: intake mani holder 8: lower block

9: middle block 10: upper block

13, 14: branch pipe 15, 16: surge tank

17: bulkhead 21, 22, 26: control valve

23, 24: branch short circuit 25: connection path between tanks

26: control valve

[Industrial use]

The present invention relates to an improvement of a variable intake apparatus of an internal combustion engine.

[Prior art]

In order to maintain the suction efficiency by moving from a low speed to a high speed, there is a change in the length of the branch pipe connecting the surge tank and the cylinder depending on the operating conditions.

As the variable intake apparatus provided with the V-shaped engine, there is a conventional example shown in FIG. 7 (see Japanese Patent Application Laid-Open No. 3-17233).

In other words, the intake manifold holder 50 crosses the branch pipes 53 communicating with the respective cylinders of the left and right banks 51 and 52, and the left and right surge tanks 54 and 55 which collect the branch pipes 53. Are disposed on the left and right banks 51 and 52.

The center surge tank 56 is arrange | positioned above each branch pipe 53, and the branch short circuit 57 which connects the middle surge tank 56 and the middle surge tank 56 of each branch pipe 53 is formed.

A branch control valve 59 is provided to open and close each branch short circuit 57 in accordance with an operating state. By opening and closing each branch control valve 59 to change the intake passage length, it is possible to increase the supercharging effect of the intake air according to the engine speed.

[Problem to Solve Invention]

However, in the conventional air intake mani holder 50 as described above, the respective branch pipes are formed by the space of the engine room limited for the structure in which the left and right surge tanks 54 and 55 protrude and are disposed on the left and right banks 51 and 52. There is a problem that the length of 53) and the volumes of the left and right surge tanks 54 and 55 are restricted, and the suction efficiency cannot be sufficiently increased.

In addition, since the intake mani holder 50 generally forms three surge tanks 54 and 56 and respective branch pipes 53, the structure is complicated, and blow-by-gas and EGR There is a problem that the degree of freedom for providing a passage for refluxing gas and the like is small.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and aims to reduce the size of an intake mani holder in a variable intake apparatus of an internal combustion engine and to increase the degree of freedom of arrangement of various passages.

[Means for solving the problem]

The invention described in claim 1, wherein the branch pipes communicating with the respective cylinders of the left and right banks facing each other in a V-shape cross each other, and a surge tank having a predetermined volume is disposed above each branch pipe, and each branch pipe is disposed with respect to the surge tank. It has a cross-sectional shape and has a branch valve which opens the middle of each branch pipe to each surge tank in the partition wall separating them, and has a control valve to open and close each branch communication path according to the operating conditions. .

According to the invention of claim 2, in the invention of claim 1, the two communication tanks which aggregate the branch pipes communicating with the cylinder groups of the left and right banks are formed and the communication path between the tanks communicating with each of the surge tanks is formed. It is provided with a tank control valve for forming and opening and closing the communication path between the tanks in accordance with the operating conditions.

The invention of claim 3 is an intermediate block having an upper block for forming a surge tank, a lower block for forming each branch pipe, and a partition wall for separating the surge tank and each branch pipe in the invention according to claim 1. Are formed by dividing each other and form a passage for guiding the fluid sucked into the trachea at the junction of the upper block or the lower block to the intermediate block.

[Action]

According to the invention of claim 1, the branch control valve is closed in the low-rotation region to lengthen the intake passage length of each branch pipe so as to perform resonance supercharging using the pulsating energy of the intake air. The branch control valve opens the branch short circuit in the high rotation region to shorten the length of the intake passage of each branch pipe, thereby performing inertia performance using the kinetic energy of the intake air.

Each branch pipe crosses each other, and is connected to each surge tank disposed above it in a J-shape to be connected to each other so that the length of the intake passage and the volume of the surge tank are sufficiently secured while the engine height is kept low. Inhalation efficiency can be improved.

Since each surge tank is arranged above each branch pipe, each surge tank does not overhang on the left and right banks, but the rigidity of the intake mani holder can be secured sufficiently to suppress the generation of vibration.

According to the invention of claim 2, in the invention according to claim 1, the opening area of the intake pipe in a wide range of the rotational speed is varied by changing the opening area according to the operating conditions such as the engine rotational speed in the inter-tank communication path communicating the two surge tanks. You can increase your performance pay.

According to the invention of claim 3, the invention of claim 1 or 2 forms a passage for guiding a blow-by-gas and an EGR gas to a junction of an upper block or a lower block with respect to an intermediate block formed by dividing each other. As a result, the degree of freedom in arranging these passages with respect to the intake mani holder is large, and the gas delivered from these passages can be evenly distributed to each cylinder.

For example, by dividing the lower block and the middle block along the branch pipes, and also by dividing the middle block and the upper block at the ends of the branch pipes and the branch short circuits, each block can be formed in diecast and productivity can be increased. .

EXAMPLE

Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

As shown in FIG. 1, the V-type six-cylinder engine has left and right cylinders 2 and 3 installed on the upper side of the cylinder block 1, and an intake manifold holder 6 is provided inside the left and right cylinder heads 2 and 3, respectively. An exhaust pipe (not shown) is connected to the outside of the left and right cylinder heads 2 and 3. In addition, the left and right banks gather cylinders that are not continuous in the ignition order.

Here, if a line segment orthogonal to the left and right banks and a line segment orthogonal to the crankshaft (not shown) is used as the center line B between the banks, the plane perpendicular to the center line B between the banks is a horizontal plane and the center line B between the banks is horizontal. The direction away from the bank axis is defined as upward.

The intake manifold holder 6 is composed of two surge tanks 15 and 16 in which branch pipes 13 and 14 communicate with respective intake holders of the left and right cylinder heads 2 and 3 to aggregate the branch pipes 13 and 14. It is provided.

Each branch pipe 13 and 14 is provided crossing each other on the front view of FIG. That is, each branch pipe 13 connected to the right bank 2 extends on the left bank, and each branch pipe 14 connected to the left bank 3 extends on the right bank.

The intake manifold holder 6 includes a lower manifold holder 7 connected to the left and right cylinder heads 2 and 3 and a lower block 8 and an intermediate block 10 which are sequentially stacked on top of the lower manifold holder 7. It is formed by dividing at.

As shown in FIG. 2, the intermediate block 9 has partition walls 17 for separating the branch pipes 13 and 14 and the surge tanks 15 and 16, respectively. The partition 17 extends in the horizontal direction, and each branch pipe 13 and 14 is connected to each surge tank 15 and 16 with a J-shaped cross section. Therefore, the surge tank 15, the branch pipe 13, the surge tank 16 and the branch pipe 14 have a structure of a two-story building parallel to the top and bottom via the partition 17, respectively.

Each branch short-circuit 23 and 24 opens to the partition 17. Each branch short-circuit 23, 24 is formed inclined at a predetermined angle so as to extend in the same direction as the intake ports of the cylinder heads 2, 3. Therefore, each branch short circuit path 23 and 24, each branch pipe 13 and 14, and each intake port do not bend large, but continue straight.

In the branch short circuit paths 23 and 24, butterfly branch control valves 21 and 22 are interposed. Each branch control valve 21, 22 opens and closes each branch short-circuit 23, 24 by rotating according to an operating condition by an actuator (not shown) and a control device thereof.

An inter-tank communication path 25 is formed between the upper block 10 and the intermediate block 9 to communicate the surge tanks 15 and 16. A butterfly tank control valve 26 is interposed between the tank communicating paths 25. Each tank control valve 26 opens and closes the communication path 25 between tanks by rotating according to an operating condition by the actuator (not shown) and its control apparatus.

In the low-speed range, the branch control valves 21 and 22 are closed, the tank control valve 36 is closed, and resonance supercharging is performed. In the medium speed region, the branch control valves 21 and 22 are closed, the tank control valve 36 is opened, and inertia is carried out. In the high-speed range, the branch valves 21 and 22 are opened, and the tank control valve 36 is opened to perform inertia performance.

As shown in FIG. 3, a blow-by-gas passage 28 is formed at the joint surface 27 with respect to the intermediate block 9 of the lower block 8 and at the same time as shown in FIG. At the joining surface 39 to the lower block 8 of 9, a blow-by gas passage 30 is formed. Each blow-by gas 30 and 28 communicate with each other, and the blow-by gas passage 30 communicates with the crank chamber through a pipe (not shown) and blows the blow-by gas blown into the crank chamber at the gap between the piston and the cylinder. It is refluxed into the holder 6.

The blow-by gas passage 28 is formed by bending to bypass each branch pipe 13, 14 and the six blow-by gas communicating the blow-by gas passage 28 with each branch pipe 13, 14. The air vent 29 is formed.

As shown in FIG. 4 and FIG. 5, the EGR passage 32 is formed in the back surface of each joining surface 31 and 41 of the intermediate block 9 and the upper block 10, respectively. The EGR passage 32 communicates with the exhaust pipe via a pipe (not shown) and a control valve to return a part of the exhaust gas into the intake mani holder 6. As a part of the exhaust gas returns to the combustion chamber via the intake mani holder 6, the maximum temperature at the time of combustion is lowered to suppress the generation of NOx, which is a harmful component in the exhaust gas.

The EGR passage 32 is formed along the rear of each surge tank 15, 16, and the EGR gas blower 33, which communicates the EGR passage 32 and each surge tank 15, 16 to the intermediate block 9, is provided. 34) are formed respectively.

Auxiliary air passages 35 are formed in front of the joining surfaces 31, 41 of the intermediate block 9 and the upper block 10, respectively. The auxiliary air passage 35 communicates with the intake passage upstream of the intake throttle valve via a pipe (not shown) and the auxiliary air amount control valve. The auxiliary air amount control valve adjusts the amount of intake air present at the time of full closing of the intake throttle valve by controlling the valve opening time, and feedback-controls the idle circuit number of the engine to the target value.

The auxiliary air passage 35 is formed along the front portion of each surge tank 15, 16, and an auxiliary air blower opening communicating the auxiliary air passage 35 and each surge tank 15, 16 to the upper block 10 ( 36 and 37 are formed respectively.

As shown in FIG. 6, the upper block 10 is formed with two inlets 43 and 44 for introducing intake air into the surge tanks 15 and 16, respectively. A throttle chamber (not shown) is connected to each inlet port 43 and 44, and the intake air amount is adjusted by the intake throttle valve attached to the throttle chamber.

It is comprised as mentioned above, and an operation | movement is demonstrated next.

The intake air received by the air cleaner (not shown) is sent to each surge tank 15, 16 through each inlet 43, 44 in the throttle chamber, and then intake strokes are sequentially received through the branch pipes 13, 14, respectively. Is sucked into the cylinder.

In the low-rotation region, the branch control valves 21 and 22 are closed together to lengthen the intake passage length of each branch pipe 13 and 14, and the surge tanks 15 and 16 via the tank control valve 26. Resonant supercharging is performed by using the pulsating energy of the intake air by changing the opening area communicating with ().

Since the branch pipes 13 and 14 cross each other and are connected to each of the surge tanks 15 and 16 arranged above, they are connected in a J-shape, the respective intake passage lengths and surges are suppressed while suppressing the overall engine height. The volume of the tanks 15 and 16 is sufficiently secured, and the suction efficiency at low rotation is increased.

In the high-rotation region, the branch control valves 21 and 22 are opened together to shorten the length of the intake passages of the branch pipes 13 and 14, and open the tank control valve 26 to open the respective surge tanks 15 and 16. ) Is used to perform inertia pay using the kinetic energy of the intake air.

Since each branch short-circuit 23 and 24, each branch pipe 13 and 14, and each intake port extend straight without being largely curved, the intake resistance flowing through them is suppressed small to increase the suction efficiency at high rotation. .

Since the surge tanks 15 and 16 are disposed above the branch pipes 13 and 14, the surge tanks 15 and 16 do not significantly overhang on the left and right banks, and thus the rigidity of the intake manifold holder 6 is increased. It secures enough to suppress the generation of vibration.

As a blow-by gas passageway 30 is formed at the junction of the intermediate block 9 of the lower block 8, six blow-by gas vents 29 are connected to each branch pipe 13, 14. It becomes possible to open to (), and can suppress that dispersion | distribution generate | occur | produces in the amount of blow-by gas distribute | distributed to each cylinder.

As the EGR passage 32 and the auxiliary air passage 35 are formed at the junction of the intermediate block 9 and the upper block 10, respectively, the EGR gas and the auxiliary air are evenly distributed to the surge tanks 15 and 16. This makes it possible to suppress the occurrence of dispersion in the amount of EGR gas and the amount of intake air distributed to each cylinder.

The lower block 8 and the middle block 9 are divided along the centerlines of the branch pipes 13 and 14, and the middle block 9 and the upper block 10 are divided into the branch pipes 13 and 14 and the branch short circuit ( By dividing at the ends of 23 and 24, it becomes possible to form each block 8-10 by diecast, and the improvement of quality and productivity is aimed at.

[Effects of the Invention]

As described above, the invention of claim 1 intersects the branch pipes communicating with the respective cylinders of the left and right banks facing the V-shape, arranges a surge tank having a predetermined volume above each branch pipe, and divides the branch pipes. A branch control valve is connected to each other with a J-shaped cross section, and the branch short circuit which shorts the middle of each branch pipe to each surge tank is opened in the partition wall which blocks both, and each branch communication path opens and closes according to an operating condition. For this purpose, the rigidity of the intake mani holder is sufficiently secured to suppress the generation of vibration and the engine height is sufficiently secured while sufficiently securing the intake passage length and the volume of the surge tank to increase the suction efficiency.

According to the invention of claim 2, in the invention of claim 1, two surge tanks for collecting branch pipes communicating with the cylinder groups of the left and right banks are formed, and an inter-tank communication path for communicating each surge tank forms an inter-bank communication path. In order to provide a bank control valve for opening and closing the valve according to the operating conditions, the intake air in the intake mani holder is controlled according to the operating conditions, thereby increasing the supercharging effect of the intake air over a wide range of revolutions.

The invention according to claim 3, wherein in the invention according to claim 1 or 2, an intermediate block having an upper block for forming a surge tank, a lower block for forming each branch pipe, and a partition wall for blocking the surge tank and each branch pipe is provided. It is formed by dividing each other, and by simplifying the shape of each block to form a passage for guiding the fluid sucked into the engine at the junction of the upper block or the lower block with respect to the intermediate block, while improving the quality and productivity, the intake mani holder It is possible to secure a large degree of freedom in arranging these passages relative to each other, and to distribute the gas guided in these passages evenly to each cylinder, and to prevent impairment of engine operability.

Claims (3)

The branch pipes communicating with each cylinder of the left and right banks facing each other in a V-shape cross each other, and a surge tank having a predetermined volume is disposed above each branch pipe, and each branch pipe is connected to the surge tank with a J-shaped cross section. A variable intake of an internal combustion engine, comprising a branch control valve which opens the middle of each branch pipe to a partition wall for separating both of the branch short circuits to short circuits to the surge tanks, and opens and closes each branch communication path according to the operating conditions. Device. The method according to claim 1, wherein two surge tanks for collecting branch pipes communicating with the cylinder groups of the left and right banks are formed, and an inter-bank communication path for communicating each surge tank is formed to open and close the inter-bank communication path according to the operating conditions. A variable intake apparatus for an internal combustion engine, comprising a tank control valve. The intermediate block according to claim 1 or 2, wherein an intermediate block having an upper block for forming a surge tank, a lower block for forming each branch pipe, and an intermediate block having a partition wall for separating the surge tank and each branch pipe are formed by dividing each other. And a passage for guiding fluid drawn into the engine at the junction of the upper block or the lower block to the variable intake apparatus of the internal combustion engine.