JPH048304Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an intake passage device for a V-type internal combustion engine.

<Prior art> As a conventional intake passage device of this type, there is one shown in FIG. 4, for example.
No. 107263 (see Japanese Unexamined Patent Publication No. 59-231161).

To give an overview based on the diagram, in a V-type 6-cylinder internal combustion engine, the #1, #3, and #5 cylinders (hereinafter collectively referred to as the first cylinder group) arranged in the cylinder bank on the left side of the diagram are in the ignition order. are not consecutive, and the intake valve opening timings do not overlap with each other.
#2, #4, arranged in a row in the right cylinder bank
The #6 cylinder (hereinafter collectively referred to as the second cylinder group) also has a relationship in which the opening timings of the intake valves do not overlap with each other.

Each branch intake passage 21 connected to each cylinder of the first cylinder group is connected to an intake collector 22 , and each branch intake passage 23 connected to each cylinder of the second cylinder group is connected to an intake collector 24 . The upstream end of the intake passage 25 extends from the end of one intake collector 22 on the #1 cylinder side to the right in the figure, and the upstream end of the intake passage 25 extends from the end of the other intake collector 24 on the #6 cylinder side to the right. Throttle chambers 29 and 30 each having a throttle valve 27 and 28 interposed therein are connected to the upstream ends of the intake passages 26 that extend continuously in the direction, and furthermore, the upstream ends of each throttle chamber 29 and 30 are connected to They are connected to one common surge tank 33 via connecting members 31 and 32, respectively.

An air flow meter and an air cleaner (not shown) are connected to the upstream side of the surge tank 33, and fuel injection valves (not shown) are installed in the branch intake passages 21 and 23 of each cylinder, respectively.

<Problems to be solved by the invention> By the way, in the case of such a conventional intake passage device for a V-type internal combustion engine, as shown in FIG.
The intake collector of each cylinder group and the surge tank are connected via a straight upstream intake passage.

For this reason, a difference occurs between the effective passage length of the intake passage from the surge tank to each combustion chamber of the first cylinder group and the effective passage length of the intake passage from the surge tank to each combustion chamber of the second cylinder group. Since the natural frequencies of the air columns are different, the amount of air supplied to the first cylinder group and the second cylinder group is different, which reduces responsiveness during transient operation and causes a difference in the mixture concentration in the combustion chamber. Exhaust composition deteriorates.

Further, since the upstream ends of the two intake passages connected to the surge tank are located at both ends of the engine and are separated from each other, the surge tank becomes large and responsiveness during transient operation is reduced in this respect as well.

Furthermore, since the length of the intake passage between the surge tank and the intake collector cannot be made sufficiently long, the natural frequency of the air column is small, resulting in a problem of insufficient low- and medium-speed output.

The present invention was developed by focusing on these conventional problems, and by improving the shape of the intake passage, it is possible to equalize the amount of air supplied to each cylinder, improve responsiveness during transient operation, and improve the air-fuel mixture. It is an object of the present invention to provide an intake passage device for a V-type internal combustion engine, which can improve the exhaust composition by making the concentration uniform, and can also improve the output during low and medium speed operation.

<Means for Solving the Problems> For this reason, the present invention provides a V-type internal combustion engine in which a pair of V-shaped cylinder banks is each provided with a cylinder group consisting of cylinders whose intake valve opening timings do not overlap with each other. In the intake passage device of The cylinders are connected in communication with the corresponding intake collectors, are connected in communication with mutually different ends of each intake collector, extend to one side with respect to the center line sandwiching both cylinder banks, and have the same length. The upstream intake passages are disposed with their respective upstream portions close to each other, and a throttle valve is provided in the adjacent portion of each upstream intake passage that is connected to a common support shaft and opens and closes in conjunction with each other, The upstream end of each upstream intake passage is communicated and connected to a common surge tank, and a part of the inner side wall of the intake passage extending from the intake collector on the side far from the surge tank also serves as a partition wall from the other intake collector. shall be.

<Function> With this configuration, each upstream intake passage has the same length, so the amount of air supplied to the combustion chamber of each cylinder group is equalized, improving responsiveness during excessive operation, etc.
Further, by making the mixture concentration uniform, the exhaust gas composition is improved.

Furthermore, since the upstream portions of the upstream intake passages are disposed close to each other, the surge tank can be downsized and responsiveness during transient operation can be further improved.

Furthermore, since the upstream intake passage can be bent to have a sufficiently large passage length, it is also possible to reduce the natural frequency of the air column and secure output during low to medium speed operation.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

In FIGS. 1 and 2 showing the configuration of an embodiment, #1, #3, and #5 are respectively provided in a pair of cylinder banks forming a V-shape of a V-type six-cylinder internal combustion engine 1.
In the first cylinder group consisting of cylinders and the second cylinder group consisting of cylinders #2, #4, and #6, the ignition timings of each cylinder in each cylinder group are not consecutive, and the opening timings of the intake valves do not overlap. (Therefore, there is no intake interference).

The intake ports of each cylinder of the first cylinder group and the second cylinder group are opened in the V-shaped inner wall of the cylinder bank. Each branch intake passage 2 connected to each intake port opening of the first cylinder group and each branch intake passage 3 connected to each intake port opening of the second cylinder group each extend upward and have upstream portions close to each other. The upstream end of each branch intake passage 2 of the first cylinder group is connected in communication with the bottom wall of an intake collector 4 disposed horizontally above the cylinder banks, and the upstream end of each branch intake passage 2 of the second cylinder group The upstream end of the intake collector 3 is connected to the bottom wall of an intake collector 5 adjacent to the intake collector 4 via a partition wall.

It extends horizontally from the front end of the intake collector 4 (the end on the #1 cylinder side) to the second cylinder group side while being adjacent to the front end of the other intake collector 5 (the end on the #2 cylinder side). An intake passage 6 whose upstream end part is bent rearward and whose upstream end extends again toward the second cylinder group side, and an intake passage 6 which extends from the rear end of the intake collector 5 (the end on the #6 cylinder side) to the second cylinder like the intake passage 6. An intake passage 7, which extends horizontally toward the group side, bends forward, has an upstream end close to the intake passage 6, and extends again toward the second cylinder group side is integrated with each intake collector 4, 5. It is formed.

At the upstream end of each of the intake passages 6, 7, a throttle valve 8,
Throttle chambers 10 and 11 are connected to one surge tank 1 through connecting members 12 and 13, respectively.
Connected to 4. A single intake pipe 15 is connected to the bottom wall of the surge tank 14 , and an air cleaner 17 is connected to the upstream end of the intake pipe 15 via an air flow meter 16 .

Here, an upstream intake passage formed by an intake passage 6, a throttle chamber 10, and a connecting member 12 connecting one intake collector 4 and the surge tank 14, the other intake collector 5, and the surge tank 1.
Intake path 7 connecting between 4 and throttle chamber 1
1. It has the same length as the upstream intake passage formed by the connecting member 13.

Further, the throttle chambers 10 and 11 are integrally connected, and the throttle valves 8 and 9 are opened and closed in conjunction with each other by a common short shaft 18.

Furthermore, a part of the partition wall that partitions the two intake collectors 4 and 5 is opened, and the opening is closed in a low-to-medium speed range below a predetermined engine speed (for example, 3200 rpm), and in a high-speed range above a predetermined engine speed. Control valve 19 that opens with
will be established.

Note that fuel injection valves 20 are installed in the branch intake passages 2 and 3 of each cylinder, respectively.

Next, the action will be explained.

During operation of the engine, air sucked from the air cleaner 17 flows into the surge tank 14 via the intake pipe 15 after its flow rate is measured by the air flow meter 16 . From here, connecting member 1
2. Through the throttle chamber 10, one upstream intake passage consisting of the intake passage 6, and the intake collector 4, each branched intake passage 2 is distributed to the combustion chamber of each cylinder of the first cylinder group, and connected. The air is distributed from each branch intake passage 3 to the combustion chamber of each cylinder of the second cylinder group via the other upstream intake passage consisting of the member 13, the throttle chamber 11, the intake passage 7, and the intake collector 5.

On the other hand, fuel is injected and supplied from the fuel injection valves 20 provided in each of the branch intake passages 2 and 3 at a predetermined timing. Here, the fuel injection amount is set by a control circuit (not shown) based on signals detected not only by the air flow meter 16 but also by an engine speed sensor (not shown), a throttle valve opening sensor, and the like.

Now, when the throttle valves 8 and 9 are opened, the length of the upstream intake passage between the surge tank 14 and one intake collector 4 is equal to the length of the upstream intake passage between the surge tank 14 and the other intake collector 5. Since the lengths of the passages are set to be the same, the natural frequencies of the air columns in the respective passages are equal, and as a result, substantially the same amount of air is supplied to the first cylinder group and the second cylinder group.

As a result, the responsiveness of the engine is improved and the exhaust composition is improved (HC, CO, NOx, etc. are reduced). In particular, the above effect is remarkable during transient operation such as sudden acceleration when the throttle valves 8 and 9 are suddenly opened. Further, since the upstream ends of the upstream intake passages are provided close to each other, the surge tank 14 can be downsized, and from this point of view as well, responsiveness during transient operation can be improved.

In addition, since these upstream intake passages are bent so that their upstream ends are close to each other, the passage length can be made sufficiently large, thereby reducing the natural frequency of the air column in this passage part. This can enhance the inertia supercharging effect at low and medium speeds and improve output.

Incidentally, in a 4-stroke engine with a displacement of 2 to 3, the intake valve (#3 in the first cylinder group) is removed from the surge tank 14.
The passage length to the cylinder (for the 2nd cylinder group, the #4 cylinder is referenced) is 50 to 100 cm, the length of the branch intake passages 2 and 3 (between the intake collector and the intake valve) is 15 to 30 cm, the intake collector 4, When the capacity of the control valve 19 is set to 0.5 to 1.0 and the capacity of the surge tank 14 is set to 0.6 to 1.5, the control valve 19 is
is closed, the effective passage length from the surge tank 14 to the intake valve increases, and the full load output increases as shown in FIG.

On the other hand, in a high-speed range exceeding 3200 rpm, the control valve 19 is opened and the intake passages of all cylinders merge in the space where the two intake collectors 4 and 5 communicate. Only the branched intake passages 2 and 3 constitute the intake passage supplied to inertial supercharging. The branched intake passages 2 and 3 are sufficiently short and inertia supercharging matched to the high speed range is performed, so that high output can be obtained even in the high speed range as shown in FIG.

The two throttle valves 8 and 9 are provided in an integrated throttle chamber 10 and 11, and can be opened and closed in conjunction with the same short support shaft 18, and can be easily adjusted to the same opening degree. can be done.

In addition, since the upstream ends of the two upstream intake passages are formed close to each other and integrally connected as shown in the figure, and are led out to the center in the longitudinal direction of the engine, the passages of these upstream intake passages are It has sufficient rigidity even if the length is increased, and the overhang is short,
Damage etc. can be prevented.

Although this embodiment is provided with a control valve that changes the effective length of the intake passage according to the engine speed, it is of course applicable to a system without a control valve, and sufficient effectiveness can be obtained even in this case. .

<Effects of the invention> As explained above, according to the invention, each cylinder group consisting of cylinders in which the intake valve opening timings of each cylinder bank of a V-type internal combustion engine do not overlap is connected to an intake collector, and these intake valve opening timings are connected to an intake collector. The upstream intake passages connected to the collectors are of the same length, and their upstream parts are placed close to each other on the same side of the engine, and connected to the surge tank. This makes it possible to equalize the amount of air supplied to the combustion chambers of each cylinder group in response to the opening and closing of the throttle valves, and together with the miniaturization of the surge tank, it is possible to improve the responsiveness of the engine, especially during transient operation.
Furthermore, it is possible to improve the exhaust gas composition by making the mixture concentration uniform. Furthermore, since a plurality of throttle valves can be linked together using a short common support shaft, it also has the advantage that they can be easily adjusted to the same opening degree.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the configuration of an embodiment of the present invention, Fig. 2 is a front view of the same embodiment, Fig. 3 is a diagram showing the output torque characteristics of the above embodiment, and Fig. 4 is a conventional example. FIG. 1... V-type 6-cylinder internal combustion engine, 2, 3... Branch intake passage, 4, 5... Intake collector, 6, 7... Intake passage, 8, 9... Throttle valve, 10, 11... Throttle Chamber, 12, 13... Connection member, 14...
Surge tank.

Claims (1)

[Scope of utility model registration request] In an intake passage device for a V-type internal combustion engine, in which a pair of cylinder banks forming a V-shape are each provided with a cylinder group consisting of cylinders whose intake valve opening timings do not overlap with each other, a pair of cylinder banks adjacent to each other are located between the two banks. The intake collectors are arranged along the direction of the cylinder row, and the branch intake passages connected to each cylinder in each cylinder group are communicated and connected to the corresponding intake collectors provided in each cylinder group. connected to mutually different ends and extending to one side with respect to the center line sandwiching both cylinder banks,
The upstream intake passages are arranged with their upstream portions close to each other so that they have the same length, and are connected to a common shaft to open and close in conjunction with the adjacent portions of the upstream intake passages. In addition to providing a throttle valve, the upstream end of each upstream intake passage is connected in communication with a common surge tank, and a part of the inner side wall of the intake passage extending from the intake collector on the side far from the surge tank is connected to the other intake collector. An intake passage device for a V-type internal combustion engine, characterized in that it is configured to also serve as a partition wall.