JPH0727374Y2 - Intake device for V-type 8-cylinder internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an intake device for a V-type 8-cylinder internal combustion engine.

Conventional technology In order to effectively use the dynamic effect of intake air, it is necessary to secure a relatively long path length of the branch section from the surge tank to each intake port, and make it equal in each cylinder. .

Therefore, as an intake device for a V-type 8-cylinder internal combustion engine, a pair of surge tanks are arranged above the cylinder heads as disclosed in Japanese Utility Model Publication No. 61-53528 and Japanese Utility Model Publication No. 62-49626. However, there is known an intake device in which eight branch portions are alternately arranged so that the cylinder of the right bank is connected to the surge tank above the left bank and the cylinder of the left bank is connected to the surge tank above the right bank. ing.

The V-type 8-cylinder internal combustion engine with a bank angle of 90 ° has a one-plane type crankshaft in which crankpins are arranged every 180 °, and crankpins are arranged every 90 °. Some have a two-plane type crankshaft, but most of the engines in practical use have a two-plane type.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the configuration in which the pair of surge tanks are arranged above each cylinder head as described above, the entire internal combustion engine becomes large in size, and in particular, its overall height becomes high, so that it is easy to mount on a vehicle. It gets very bad.

The ignition sequence of the above-mentioned 2-plane V-type 8-cylinder internal combustion engine is, for example, “1-2-
7-3-4-5-6-8 "," 1-5-6-3-4-2 "
-7-8 "or the like, but in the case where the surge tanks are simply separated for each of the left and right banks as in the above-mentioned conventional case,
Two cylinders having consecutive intake strokes are included in any of the surge tanks, and the intake dynamic effect cannot be effectively obtained.

Means for Solving the Problems An intake system for a V-type 8-cylinder internal combustion engine according to the present invention is an intake system for a V-type 8-cylinder internal combustion engine in which a crankshaft has a two-plane type, and a crankshaft shaft is provided between both banks. A surge tank that is arranged in a slender shape along the direction and is divided into a pair of left and right volume chambers by a partition wall provided inside, and a concave portion between the V banks by bending downward from the intake port of the cylinder head. Four connected to the bottom of the volume chamber, which is curved in a substantially U shape at the bottom of the recessed space and extends in a direction away from the intake port, and is connected to the bottom of the volume chamber located away from the intake port. Of the branch head and the intake port of the cylinder head, and is bent downward into the recess space between the V banks, and is curved in a substantially U-shape at the bottom of the recess space, And four branch portions that extend toward the intake port and are connected to the bottom of the volume chamber located closer to the intake port, and that the branch portions are arranged so as not to intersect each other. The intake ports of # 1, # 4, # 6, and # 7 cylinders are connected to one of the volume chambers, # 2, # 3, # 5, # It is characterized in that the intake ports of the eight cylinders are respectively communicated with the other volume chamber.

Action In the above configuration, the single surge tank and the eight U-shaped branch portions are accommodated in the space between the banks. Since each branch portion is curved in a substantially U shape, a relatively long passage length can be obtained in a limited space.

In addition, since the volume chambers for # 1, # 4, # 6, and # 7 cylinders and the volume chambers for # 2, # 3, # 5, and # 8 cylinders are partitioned in the surge tank, two planes are provided. In various ignition sequences of the V-type 8-cylinder internal combustion engine, two cylinders having consecutive intake strokes are reliably separated.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

1 and 2 show a state in which a V-type 8-cylinder internal combustion engine 1 of a 2-plane type is mounted in an engine room 3 of an automobile 2 in a so-called horizontal type. In addition, in FIG.
4 is a radiator, 5 and 6 are cooling fans, 7 is a fender panel, and 8 in FIG. 2 is an engine hood.

The internal combustion engine 1 has a bank angle of 90 °, and the cylinder head 1 is provided on the upper surface of each bank of the cylinder block 9.
0,11 are placed and fixed, and each cylinder head 10,1
Each intake port 12 is opened on the inner side surface of the bank of 1. In the illustrated example, cylinder numbers are assigned as # 1, # 2, ... In order from the left side of FIG. 1, and therefore, the cylinder head 10 on the front side of FIG. 1 has # 1, # 3, # 5, # 7. There are cylinders, and the other cylinder head 11 has cylinders # 2, # 4, # 6 and # 8.

An intake manifold 13 is arranged between the cylinder heads 10 and 11 of the internal combustion engine 1. 3 to 5 show the intake manifold 13.

The intake manifold 13 is roughly divided into a flat box-shaped surge tank 14 and eight branch portions 15 to 22 led out from the surge tank 14.

The surge tank 14 has an elongated shape along the axial direction of the crankshaft and is arranged in a recessed space between the cylinder heads 10 and 11 as shown in FIGS.
A partition 36 is provided inside the surge tank 14 substantially along the center thereof, and the partition 36 defines a pair of left and right volume chambers, that is, a first volume chamber 23 and a second volume chamber 24. . As shown in FIG. 3, the surge tank 14 is integrally formed with the branch portions 15 to 22 with its upper surface opened, and a separate cover 25 is attached to the upper surface opening. 1 and 5 show the state in which the cover 25 is removed. Further, at one end of the surge tank 14, intake ports 26, 27 are opened for each of the volume chambers 23, 24, and a throttle chamber 30 equipped with two throttle valves 28, 29 is attached. At the other end of the surge tank 14, communication ports 31 and 32 are opened for each of the volume chambers 23 and 24, and a control valve chamber 33 is provided to cover the communication ports 31 and 32.
Is attached. The control valve chamber 33 has a passage portion 34 that allows the communication ports 31 and 32 to communicate with each other, and a butterfly valve type intake control valve 35 that interrupts the communication between the passage portions 34 and 32 in the middle thereof. That is, when the intake control valve 35 is closed, both volume chambers 23 and 24 are separated and independent, and when the intake control valve 35 is open, both volume chambers 2 and 2 are separated.
3,24 is practically one. Therefore, by controlling the opening / closing of the intake control valve 35 based on the engine speed or the like, the intake dynamic effect can be utilized over a wide operating range.

On the other hand, each of the branch parts 15 to 22, as shown in FIGS.
Each has a substantially U shape that bulges downward, and its base ends 15a to 22a are connected to the bottom surface of the surge tank 14, respectively, and the flange portions 15b to 22b at the tips are fixed to the cylinder heads 10 and 11. Connected to each intake port 12. These branch parts 15 to 22 are roughly classified into two types. That is, the intake port of the cylinder head 11
It is bent downward from 12 toward the concave space between the V banks, is curved in a substantially U-shape at the bottom of the concave space, and extends in a direction away from the intake port 12 and is separated from the intake port 12. The four branch parts 15, 16, 21, 22 connected to the bottoms of the volume chambers 23, 24 located at the position and the intake port 12 of the cylinder head 11 are bent downward to enter the concave space between the V banks. The volume chamber facing the intake port 12 and curved toward a substantially U-shape at the bottom of the recess space and extending toward the intake port 12
It is provided with four branch parts 17, 18, 19, 20 connected to the bottom surfaces of 23, 24. For more details, please refer to branch # 15 for # 1 cylinder and # 7.
It has substantially the same shape as the cylinder branch portion 21, the tip is connected to each cylinder of the cylinder head 10, and the base end
15a and 21a open to the first volume chamber 23 located on the opposite side, that is, on the cylinder head 11 side. Then, the second cylinder branch unit 16 and the # 8 cylinder branch unit 22 have the above-mentioned # 1, #
It has a substantially symmetrical shape with the branch parts 15 and 21 for 7 cylinders,
The tip end is connected to each cylinder of the cylinder head 11, and the base ends 16a and 22a open to the second volume chamber 24 located on the opposite side, that is, on the cylinder head 10 side.

In addition, # 3 cylinder branch section 17 and # 5 cylinder branch section 19
And have substantially the same shape. These have a shape that is more strongly curved than the above-mentioned four branch portions 15, 21, 16 and 22, and the tip end is connected to each cylinder of the cylinder head 10, and the base ends 17a and 19a are It opens to the second volume chamber 24 located on the same side as this. And
# 4 cylinder branch 18 and # 6 cylinder branch 20
Has a substantially symmetrical shape with the # 3 and # 5 branch portions 19 and has a tip connected to each cylinder of the cylinder head 11 and a base end 18a, 20a located on the same side as the first end.
It opens to the volume chamber 23.

The above eight branch portions 15 to 22 are set to have substantially equal passage lengths.

In addition, the base ends 17a to 20a of the branch portions 17 to 20 for the # 3 to # 6 cylinders.
Is opened toward the center line of the surge tank 14, the partition wall 36 that divides both volume chambers 23 and 24 is
As shown in the figure, it is bent along the opening edge.

Now, in the above structure, the intake manifold 13 can be made very compact as a whole and can be completely housed in the space between the cylinder heads 10 and 11 of both banks, as shown in FIG. That is, the cylinder head 10,1
It does not project above 1, so that the engine hood 8 can be placed sufficiently low.
The internal combustion engine 1 has a center line m as shown in FIG.
Is mounted in a state in which it is tilted forward about 10 ° with respect to the vertical plane l.

In addition, # 1, # 4, # 6, and # 7 cylinders are placed in the first volume chamber 23, # 2, # 3,
The # 5 and # 8 cylinders are respectively connected to the second volume chamber 24, so that the "1-
2-7-3-4-5-6-8 "," 1-5-6-3-4 "
In the case of the ignition sequence such as "-2-7-8", two cylinders having consecutive intake strokes are reliably separated. That is, the cylinders included in the first volume chamber 23 and the cylinders included in the second volume chamber 24 are alternately ignited, and the intake dynamic effect can be effectively used. Moreover, by bending each of the branch portions 15 to 22 into a substantially U shape, it is possible to secure a sufficiently large passage length in the limited space between the banks.

EFFECTS OF THE INVENTION As is clear from the above description, in the intake system for the V-type 8-cylinder internal combustion engine according to the present invention, the intake device having a sufficiently long passage length is effectively used by effectively utilizing the recessed space between the banks. It can be accommodated in the space, and the internal dimensions of the internal combustion engine can be reduced, and the overall height can be shortened. Moreover, the passage lengths of the cylinders can be made substantially equal in a limited space. Further, the intake passages of the two cylinders having continuous intake strokes can be reliably separated by the partition wall, and the intake dynamic effect can be effectively used.

[Brief description of drawings]

FIG. 1 is a plan view of a V-type 8-cylinder internal combustion engine according to the present invention mounted on a vehicle, FIG. 2 is a sectional view of the same, and FIG. 3 is a sectional view of an intake manifold taken along line III-III in FIG. ,
FIG. 4 is a perspective view of the intake manifold, part of which is shown in phantom lines,
FIG. 5 is an exploded perspective view showing the structure of each branch portion. 13 ... Intake manifold, 14 ... Surge tank, 15-22 ...
… Branch section, 23 …… First volume chamber, 24 …… Second volume chamber,
36. Partition wall.

Claims (1)

[Scope of utility model registration request] 1. An intake system for a V-type 8-cylinder internal combustion engine in which a crankshaft has a two-plane type, and is disposed between both banks so as to have an elongated shape along the axial direction of the crankshaft, and is internally provided. The surge tank is divided into a pair of left and right volume chambers by the partition wall provided, and is bent downward from the intake port of the cylinder head toward the concave space between the V banks, and is substantially U-shaped at the bottom of the concave space. The four branch portions that are curved and extend in a direction away from the intake port and are connected to the bottom surface of the volume chamber at a position away from the intake port, and are bent downward from the intake port of the cylinder head to V. A position toward the inside of the recessed space between the banks, curved in a substantially U-shape at the bottom of the recessed space, and extending toward the intake port and close to the intake port It comprises four branch parts connected to the bottom of a volume chamber, and the branch parts are arranged so as not to intersect with each other and are configured to have a substantially equal length, and through the respective branch parts, The intake ports of the # 1, # 4, # 6, and # 7 cylinders were connected to one of the volume chambers, and the intake ports of the # 2, # 3, # 5, and # 8 cylinders were connected to the other volume chamber. V type 8 characterized by
Intake device for a cylinder internal combustion engine.