JP2006183524A - Intake device for multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable resonance supercharge in a low-middle speed zone and inertia supercharge in a high speed zone by a separate type intake air collector even in a V-type eight cylinder internal combustion engine provided with a double plane crankshaft in which combustion occurs at uneven intervals in cylinders in each bank. <P>SOLUTION: An intake port 13 of each cylinder is connected to both of a first intake air collector C1 and a second intake air collector C2 with equal passage length by intake air passages 11, 12 provided for each cylinder. All cylinders are separated to a group of half numbers of cylinders of which ignition order is every other order and a group of rest of cylinders. First intake control valves 14 connecting and separating the first intake air collector C1 and the intake port 13 are provided on the cylinders of one group, and second intake air control valves 15 connecting and separating the second intake air collector C2 and the intake air port 13 are provided on the cylinders of another group. The first and the second intake air control valves 14, 15 are closed in the low-middle speed zone and is opened in the high speed zone. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intake device for a multi-cylinder internal combustion engine.

In Patent Document 1, in a V-type 6-cylinder internal combustion engine, an intake collector (distribution chamber) is provided for each bank, so that low-speed torque is improved by resonance supercharging, and these two intake collectors are made to communicate with each other. What improves high-speed torque by supercharging is disclosed.
JP 05-098968 A

In the V-type 6-cylinder internal combustion engine as in Patent Document 1, since the combustion of the cylinders in each bank is equally spaced, if an intake collector is provided for each bank, the low-speed torque is improved due to the effect of pulsation. High speed torque (maximum output) can be improved by connecting the intake collector.
However, in a V-type 8-cylinder internal combustion engine, particularly a V-type 8-cylinder internal combustion engine having a double plane crankshaft, the combustion of the cylinders in each bank is not equally spaced. The effect cannot be used, and improvement in low-speed torque cannot be expected.

  Therefore, in general, in a V-type 8-cylinder internal combustion engine of a double plane crank (unequally spaced combustion in a bank), inertial variable intake is used to improve low-speed torque, but the intake system tends to increase upward, The engine height cannot be reduced. On the other hand, resonance supercharging can be used for single plane cranks (equal interval combustion in the bank), but single plane cranks have problems in terms of vibration compared to double plane cranks and are difficult to adopt in passenger cars. It is.

  In view of such a situation, the present invention is an intake device applicable to a V-type eight-cylinder internal combustion engine having a double plane crankshaft, although the intake collector capable of suppressing the overall height of the engine is divided into two. The purpose is to provide.

  Therefore, in the present invention, on the assumption that the first intake collector and the second intake collector are provided, the intake port of each cylinder is connected to the first intake collector and the second intake collector by the intake passage provided for each cylinder. Both are connected, and the passage length from the intake port inlet to the first intake collector and the passage length from the intake port inlet to the intake collector are set to be approximately equal.

  According to the present invention, each cylinder can intake air equally from two intake collectors, and is equivalent to having a single large collector. Therefore, at least the maximum output can be improved. It can be developed as an intake device.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a front view of an intake device of a multi-cylinder internal combustion engine showing an embodiment of the present invention (cross-sectional view taken along line XX in FIG. 2), FIG. 2 is a plan view of the same, and FIG. It is sectional drawing.
The multi-cylinder internal combustion engine in the present embodiment is a V-type 8-cylinder internal combustion engine, and four cylinders are arranged in each of the left and right banks B1 and B2. Specifically, cylinders # 1, # 3, # 5, and # 7 are arranged in the left first bank B1, and cylinders # 2, # 4, # 6, and # 8 are arranged in the second bank B2 on the right side. Has been placed.

  Moreover, the double plane crankshaft 10 which has arrange | positioned the crankpin CP on two planes including the centerline of the journal part JN is provided. Specifically, the crankpins of the # 1, # 2 cylinder and the crankpins of the # 7, # 8 cylinder are arranged on one plane, and on the other plane (a plane that is 90 ° out of phase), 3. Crank pins for cylinders # 3 and # 4 and crank pins for cylinders # 5 and # 6 are arranged.

The ignition order is # 1 → # 8 → # 7 → # 3 → # 6 → # 5 → # 4 → # 2.
Therefore, the combustion intervals of the first bank B1 (# 1, # 3, # 5, # 7) are unequal intervals, and the combustion intervals of the second bank B2 (# 2, # 4, # 6, # 8) Are also unequal intervals.
Next, the intake system will be described.
A first intake collector C1 is disposed above the first bank B1, and a second intake collector C2 is disposed above the second bank B2.

Each of the first intake collector C1 and the second intake collector C2 has an intake inlet portion on an outer side surface at a central portion in the front-rear direction (cylinder row direction) of the engine, and includes throttle chambers T1, T2 and an intake duct D1. , D2 are connected.
Then, the intake ports 13 and 12 provided for each cylinder connect the intake port 13 of each cylinder to both the first intake collector C1 and the second intake collector C2.

  Specifically, for each cylinder (# 1, # 3, # 5, # 7) of the first bank B1, an intake port 13 is provided by an intake passage 11 extending in a parabolic manner from the inner surface of the second intake collector C2. Is connected to the second intake collector C2, and the intake port 13 is connected to the first intake collector C1 by the intake passage 12 that extends from the inner surface of the first intake collector C1 and curves and merges in the middle of the intake passage 11. Connecting.

Here, the passage length from the intake port 13 inlet to the second intake collector C2 (passage length of the intake passage 11) L1, and the passage length from the intake port 13 inlet to the first intake collector C1 (to the middle of the intake passage 11) The total passage length L2 with respect to the intake passage 12 is set to be approximately the same length. Further, not only the passage length but also the passage resistance is set to be substantially equal.
Further, for each cylinder (# 2, # 4, # 6, # 8) of the first bank B2, the intake port 13 is connected to the intake port 11 by the intake passage 11 extending in a parabolic manner from the inner surface of the first intake collector C1. The intake port 13 is connected to the second intake collector C2 by an intake passage 12 connected to the first intake collector C1 and extending from the inner surface of the second intake collector C2 to bend and merge in the middle of the intake passage 11.

Again, the passage length from the intake port 13 inlet to the first intake collector C1 (passage length of the intake passage 11) L1, and the passage length from the intake port 13 inlet to the second intake collector C2 (to the middle of the intake passage 11) The total passage length L2 with respect to the intake passage 12 is set to be approximately the same length. Further, not only the passage length but also the passage resistance is set to be substantially equal.
In other words, the intake ports 13 and 12 provided for each cylinder connect the intake port 13 of each cylinder to both the first intake collector C1 and the second intake collector C2 with substantially equal passage length and substantially equal passage resistance. To do.

  Further, for each cylinder, the first intake control valve 14 for intermittently connecting the first intake collector C1 and the intake port 13 or the second intake control valve for intermittently connecting the second intake collector C2 and the intake port 13. Any one of 15 is provided, but all the cylinders are divided into a group of half of the cylinders in which every other ignition order (intake order) and a group of remaining cylinders (the cylinders in this group also have every other ignition order). The first intake control valve 14 is provided in a cylinder belonging to one group, and the second intake control valve 15 is provided in a cylinder belonging to the other group.

  Specifically, since the ignition order is # 1 → # 8 → # 7 → # 3 → # 6 → # 5 → # 4 → # 2, every other # 1, # 7, # 6, # 4 The cylinders are divided into the remaining # 8, # 3, # 5, and # 2 cylinders. For the # 1, # 7, # 6, and # 4 cylinders, the first intake collector C1 and the intake passage 11 or 12 are connected. The first intake control valve 14 for intermittently connecting the first intake collector C1 and the intake port 13 is provided in the section, and for the # 8, # 3, # 5, and # 2 cylinders, the second intake collector C2 and the intake passage are provided. 11 or 12 is provided with a second intake control valve 15 for intermittently connecting the second intake collector C2 and the intake port 13 to each other.

  Further, as shown in FIG. 3, all the connecting portions of the intake passages 11 or 12 of the respective cylinders to the first intake collector C1 are arranged in a straight line (at the same height position), and the first intake control valve 14 is arranged. By arranging in the vicinity of the connecting portion, four first intake control valves 14 are attached to the common valve shaft 14a arranged on the straight line, and the four first intake control valves 14 are opened and closed by one actuator 14b. Make it possible.

Similarly, the connecting portions of the intake passages 11 or 12 of the respective cylinders to the second intake collector C2 are all arranged in a straight line (same height position), and the second intake control valve 15 is arranged in the vicinity of the connecting portion. Thus, the four second intake control valves 15 are attached to the common valve shaft 15a arranged on the straight line, and the four second intake control valves 15 can be opened and closed by one actuator 15b.
All the first intake control valves 14 and the second intake control valves 15 may be opened and closed by one actuator by connecting the rotating members of the two valve shafts 14b and 15b by links or the like.

The actuators 14b and 15b are controlled by a control unit 16, and a signal from a rotational speed sensor 17 for detecting the rotational speed Ne of the engine is inputted to the control unit 16.
Next, the operation will be described.
When the first and second intake control valves 14 and 15 are open, the intake port 13 of each cylinder is connected by the intake passages 11 and 12 (in other words, by a relatively straight flow path and a U-turn flow path. ), The first intake collector C1 and the second intake collector C2 are almost equally connected to each other, and the inertia supercharging can be performed by substantially increasing the capacity of the intake collector. Therefore, the characteristic indicated by the thick line in FIG. 4 is obtained, and the volumetric efficiency in the high speed region is improved, and the high speed torque (maximum output) can be improved.

  In a state where the first and second intake control valves 14 and 15 are closed, the intake port 13 of each cylinder is connected to only one of the first intake collector C1 and the second intake collector C2, and substantially four cylinders. Become an engine. The cylinders connected to the first intake collector C1 are # 2, # 3, # 5, and # 8 cylinders, and the ignition sequence (# 1 → # 8 → # 7 → # 3 → # 6 → # 5 → # 4). → As seen from # 2), since every other cylinder is used, intake air from the first intake collector C1 is equally spaced, and resonance supercharging utilizing the pulsation effect is possible. The cylinders connected to the second intake collector C2 are the cylinders # 1, # 4, # 6, and # 7, and the ignition sequence (# 1 → # 8 → # 7 → # 3 → # 6 → # 5 → # 4). → As seen from # 2), since every other cylinder is provided, intake air from the second intake collector C2 is also equally spaced, and resonance supercharging utilizing the pulsation effect is possible. Therefore, the characteristic indicated by the thin line in FIG. 4 is obtained, and the volume efficiency in the low and medium speed rolling region is improved and the low speed torque can be improved.

Therefore, as can be seen from FIG. 4, in the low and medium speed range (less than the rotational speed Neth1), the first and second intake control valves 14 and 15 can be closed to improve the low speed torque, and the high speed range (the rotational speed Neth1 or higher). ), The high-speed torque can be improved by opening the first and second intake control valves 14 and 15.
FIG. 5 is a flowchart of the opening / closing control of the first and second intake control valves 14 and 15 executed by the control unit 16.

In S1, the rotational speed Ne of the engine is read.
In next S2, the rotational speed Ne is compared with a predetermined threshold value Neth1, and it is determined whether Ne <Neth1 or not.
In this determination, if YES, that is, if Ne <Neth1 (low / medium speed range), the process proceeds to S3, and the first and second intake control valves 14, 15 are controlled to be closed.

In this determination, if NO, that is, Ne ≧ Neth1 (high speed range), the process proceeds to S4, and the first and second intake control valves 14, 15 are controlled to open.
According to this embodiment, the intake port 13 of each cylinder is connected to both the first intake collector C1 and the second intake collector C2 by the intake passages 11 and 12 provided for each cylinder, and the first intake collector from the intake port 13 inlet is connected. By setting the passage length L1 to C1 and the passage length L2 from the intake port 13 inlet to the second intake collector C2 to be substantially equal, the overall height of the engine can be suppressed by dividing the intake collector, Since intake can be performed equally from the two intake collectors C1 and C2 and is equivalent to having one large collector, the maximum output can be improved by inertia supercharging.

  Further, according to the present embodiment, all the cylinders are divided into a group of half cylinders (# 1, # 7, # 6, # 4) with every other ignition order and a group of remaining cylinders (# 8, # 4). 3, # 5, # 2), a cylinder belonging to one group is provided with a first intake control valve 14 for intermittently connecting the first intake collector C 1 and the intake port 13, and a cylinder belonging to the other group In addition, by providing the second intake control valve 15 for intermittently connecting the second intake collector C2 and the intake port 13, the first intake collector C1 is closed by closing the first and second intake control valves 14, 15. And intake air from the second intake collector C2 can be set at equal intervals, and intake pulsations entering the first and second intake collectors C1 and C2 can be set at equal intervals. It becomes possible to improve the torque .

  Further, according to the present embodiment, the connection portion of the intake passage 11 or 12 of each cylinder to the first intake collector C1 is arranged in a straight line, and the first intake control valve 14 is arranged in the vicinity of the connection portion. Thus, the plurality of first intake control valves 14 can be operated by the common valve shaft 14a, and the connection portions of the intake passages 11 or 12 of the respective cylinders to the second intake collector C2 are arranged in a straight line, and the first By disposing the two intake control valves 15 in the vicinity of the connecting portion, the plurality of second intake control valves 15 can be operated by a common valve shaft 15a.

  Further, according to the present embodiment, both the first intake control valve 14 and the second intake control valve 15 are closed when the rotational speed Ne of the engine is in the first rotational speed range (a range less than Neth1). By controlling both the first intake control valve 14 and the second intake control valve 15 to the open state when the engine rotational speed Ne is in the second rotational speed range (range of Neth1 or more). The resonance supercharging and the inertial supercharging can be switched according to the rotational speed of the engine.

Further, according to the present embodiment, by setting the low and medium speed range to the first rotation speed range and setting the high speed area to the second rotation speed range, resonance supercharging is performed in the low and medium speed range. Low-speed torque can be improved, and high-speed torque can be improved by inertia supercharging at high speeds.
However, an ultra high speed range exceeding the high speed range may be set as the first rotation speed range. This is because, depending on the engine specifications, the volumetric efficiency when the intake control valve is closed may be larger than the volumetric efficiency when the intake control valve is open in the ultra-high speed range. In this case, two rotation speed thresholds are set (Neth1 and Neth2). When the rotation speed Ne is less than Neth1, the first and second intake control valves 14 and 15 are closed, and the rotation speed Ne is equal to or higher than Neth1. When the rotational speed Ne is equal to or higher than Neth2, the first and second intake control valves 14 and 15 are closed. A flowchart in this case is shown in FIG. A difference is that in S2, the rotational speed Ne is compared with two predetermined threshold values Neth1 and Neth2 (Neth2> Neth1), and it is determined whether Ne <Neth1 or Ne ≧ Neth2. In this determination, if YES, that is, if Ne <Neth1 (low / medium speed region) or Ne ≧ Neth2 (superhigh speed region), the process proceeds to S3 so that the first and second intake control valves 14, 15 are closed. Control.

  Further, according to the present embodiment, each of the first intake collector C1 and the second intake collector C2 has an intake inlet at the center in the front-rear direction (cylinder row direction) of the engine, and the throttle chamber T1, The following effects can be obtained by connecting T2 and the intake ducts D1 and D2. Regardless of whether the first and second intake control valves 14 are opened or closed, the distance from the inlet portion of the intake passages 11 and 12 to the intake port 13 is the same between the cylinders, so that the first and second intake collectors C1 and C2 When the intake ducts D1 and D2 are connected to the central portion in the cylinder row direction, the variation between the cylinders in the distance from the inlets of the intake ducts D1 and D2 to the outlets of the first and second intake collectors C1 and C2 can be minimized. In addition, the distance from the inlets of the intake ducts D1 and D2 to the outlet of the intake manifold (inlet of the intake port 13) can be made uniform between the cylinders, so that the intake tone can be improved. In other words, the intake sound is a clear sound with basic order components.

  The present invention is generally applicable to a multi-cylinder internal combustion engine. In particular, the present invention includes two cylinder groups each including the same number of cylinders, and the two cylinder groups are arranged in a V-type or a horizontally opposed type. It is effective for a cylinder internal combustion engine. Further, particularly when a plurality of cylinders included in each cylinder group burn at unequal intervals, a remarkable effect is obtained. In other words, a remarkable effect is obtained particularly in a V-type 8-cylinder internal combustion engine having a double plane crankshaft.

FIG. 2 is a front view of an intake device for a multi-cylinder internal combustion engine showing an embodiment of the present invention (cross-sectional view taken along line XX in FIG. 2). Same as above YY sectional view of FIG. Rotational speed vs. volumetric efficiency characteristics by opening / closing intake control valve Flow chart of intake control valve opening and closing control Flow chart of another example of opening / closing control of intake control valve

Explanation of symbols

B1 1st bank
B2 Bank 2
C1 First intake collector
C2 Second intake collector
T1, T2 Throttle chamber
D1, D2 Intake duct
10 Double plane crankshaft
11, 12 Intake passage of each cylinder
13 Intake port
14 First intake control valve
15 Second intake control valve
16 Control unit
17 Rotational speed sensor

Claims (9)

In an intake device of a multi-cylinder internal combustion engine comprising a first intake collector and a second intake collector,
An intake port provided for each cylinder connects an intake port of each cylinder to both the first intake collector and the second intake collector;
An intake system for a multi-cylinder internal combustion engine, characterized in that a passage length from an intake port inlet to the first intake collector and a passage length from the intake port inlet to the second intake collector are set to be approximately equal.   All cylinders are divided into a group of half of the cylinders whose ignition order is every other one and a group of the remaining cylinders, and the cylinders belonging to one group are connected to the first intake collector and the intake port intermittently. 2. The multi-cylinder internal combustion engine according to claim 1, wherein one intake control valve is provided, and a second intake control valve for connecting and disconnecting the second intake collector and the intake port is provided in a cylinder belonging to the other group. Inhalation device. The connecting portion of the intake passage of each cylinder to the first intake collector is arranged in a straight line, and the first intake control valve is arranged in the vicinity of the connecting portion,
3. The multi-port system according to claim 2, wherein a connection portion of the intake passage of each cylinder to the second intake collector is arranged in a straight line, and the second intake control valve is arranged in the vicinity of the connection portion. Intake device for a cylinder internal combustion engine.   When the rotational speed of the engine is in the first rotational speed range, both the first intake control valve and the second intake control valve are controlled to be closed, and the rotational speed of the engine is in the second rotational speed range. 4. The intake system for a multi-cylinder internal combustion engine according to claim 2, wherein both the first intake control valve and the second intake control valve are controlled to be in an open state at a certain time.   5. An intake system for a multi-cylinder internal combustion engine according to claim 4, wherein a low and medium speed range is set in the first rotation speed range, and a high speed range is set in the second rotation speed range.   6. An intake system for a multi-cylinder internal combustion engine according to claim 5, wherein an ultra-high speed range exceeding the high speed range is set as the first rotational speed range.   7. The engine according to claim 1, wherein the engine includes two cylinder groups each including the same number of cylinders, and the two cylinder groups are arranged in a V-type or a horizontally opposed type. An intake device for a multi-cylinder internal combustion engine described in 1.   8. The intake system for a multi-cylinder internal combustion engine according to claim 7, wherein a plurality of cylinders included in each cylinder group burn at unequal intervals.   The intake system for a multi-cylinder internal combustion engine according to any one of claims 1 to 8, wherein the engine is a V-type 8-cylinder internal combustion engine having a double plane crankshaft.

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