JP2844241B2 - Multi-cylinder V-type engine intake system - Google Patents

Description

The present invention relates to an intake device for a multi-cylinder V-type engine mounted on a passenger car or the like.

[Conventional technology]

Conventionally, as an intake device for a V-type engine, an effective pipe length or a substantial sectional area of an intake pipe that communicates between an intake surge tank and a cylinder is changed according to the engine speed, and the intake pipe is resonated by inertia supercharging effect. There is one in which the filling efficiency is maintained high from a low rotation range to a high rotation range to obtain a high output (for example, Japanese Patent Application No. 61-50444). In this case, a surge tank is disposed above each cylinder row of an engine, and a plurality of intake pipes are arranged in a V-shaped space. The intake pipe includes a low-speed (primary) pipe whose overall length is set relatively long so as to obtain the effect of inertia supercharging at low engine revolutions, in other words, at normal revolutions, and a control valve that has an engine height. Two types of pipes were provided: a high-speed (secondary) pipe whose overall length was set short so as to obtain the effect of inertial supercharging during rotation. The secondary intake pipe to which intake air is supplied at the time of high engine rotation is V
It was communicated with the surge tank above the cylinder through the space, and was bent at a substantially right angle in the V-shaped space.

[Problems to be solved by the invention]

However, in the conventional intake device configured as described above, it is difficult to install a relatively long low-speed pipe in a limited V-shaped space, and the surge tank is located above the cylinder. Must be installed so as to protrude greatly. For this reason, there has been a problem that the entire engine becomes large. Further, when the secondary intake pipe is bent in the V-shaped space, there is a problem that the intake resistance is increased, and the charging efficiency of the intake air is reduced at the time of high engine rotation where a large amount of intake air is supplied.

[Means for solving the problem]

In the intake device for a multi-cylinder V-type engine according to the present invention, the secondary intake passage extends obliquely upward from the cylinder, and the primary intake passage bypasses the axis of the valve rotation axis of the control valve. It extends upward.

(Operation)

The secondary intake passage communicates with the lower part of the surge tank, and the primary intake passage passes through the side of the surge tank and communicates with the internal air chamber. The tank can be positioned lower in the V-shaped space. Further, since the secondary intake passage is substantially linearly communicated with the intake passage in the cylinder, the intake resistance can be reduced.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a front view showing a main part of an intake device of a multi-cylinder V-type engine according to the present invention cut away, and FIG. 2 is a plan view showing an enlarged intake device of a multi-cylinder V-type engine according to the present invention. FIG. 3 is a side view and FIG. 4 is a sectional view taken along the line IV-IV in FIG. In these figures, reference numeral 1 denotes a four-cylinder V-type eight-cylinder engine on one side, and reference numerals 2 and 3 denote two left and right cylinder rows of the engine 1. The cylinder row 2 includes cylinders 2a to 2d, and the cylinder row 3 includes cylinders 3a to 3d. A primary port 5 and a secondary port 6, which are communicated with each other near the intake valve 4 in the cylinder, are opened for each cylinder on the surfaces of the cylinder rows 2 and 3 facing each other. A fuel injection nozzle 7 is provided in the intake passage between the primary port 5 and the intake valve 4 so as to face the passage.

10 is an intake device for a multi-cylinder V-type engine according to the present invention,
The intake device 10 has a built-in throttle valve (not shown), an upstream side communicating with an air cleaner (not shown), a throttle box 11, and a downstream side of the throttle box 11 with an intake pipe.
The surge tank 14 is connected to the primary port 5 and the secondary port 6 of each of the cylinders via an intake passage block 13. An intake pipe 12, an intake passage block 13, and a surge tank 14 of the intake device 10 are installed in a V-shaped space between the two cylinder rows 2 and 3, and the surge tank 14 corresponds to the two cylinder rows 2 and 3.
It is fixed to the engine 1 through two intake passage blocks 13,13.

The intake passage block 13 includes a primary intake passage 13a and a secondary intake passage 13b that are respectively connected to the primary port 5 and the secondary port 6 of each cylinder.
Are provided, and two intake passages 13a, 13 per cylinder are provided.
b is integrally formed for four cylinders. Each of the secondary intake passages 13b extends obliquely upward from the cylinder toward the center in the width direction of the engine 1, and linearly communicates with the intake passage in the cylinder with the intake passage block 13 mounted on the engine 1. The inclination angle is set so as to be adjusted. The length of the secondary intake passage 13b is set so that the effect of inertia supercharging can be obtained in a high-speed operation range where the engine speed is high. In addition, each secondary intake passage 13
In the vicinity of the upper opening of b, a control valve that closes this passage when the engine speed is low and opens when the engine speed is high
15 is rotatably mounted via a valve shaft 16. The valve shaft 16 extends through all the secondary intake passages 13b in order to make the control valves 15 interlock with each other.
3 and is configured to be rotatably supported by the actuator 17. This actuator 17
Are operated by the intake negative pressure of the engine 1,
The one that is operated in accordance with the engine speed by the engine control computer is adopted, and is installed in the V-shaped space and below the surge tank 14. The primary intake passage 13a extends upward from the cylinder with a larger inclination angle than the secondary intake passage 13b so as to bypass the valve shaft 16. In the present embodiment, the intake passage block 13 is bent so as to be directed substantially upward from a connection portion with the primary port 5 in a state where the intake passage block 13 is mounted on the engine 1.

The surge tank 14 is formed to be long along the longitudinal direction of a crankshaft (not shown), and has a cylinder line 2 therein.
In addition, a partition plate 14a that defines the inside of the surge tank 14 into two chambers, A and B, corresponding to the cylinder row 3 is provided integrally. An opening 1 for communicating the intake pipe 12 with the air chambers A and B is provided at the bottom of the surge tank 14.
4b and a secondary intake passage of the intake passage block 13
An opening 14c communicating with 13b is provided. Reference numeral 18 denotes a primary intake passage for the surge tank 14. The primary intake passage 18 is a surge tank that bypasses the outside of the surge tank 14 in order to obtain a predetermined length, eight in total, one for each cylinder. 14 are provided integrally with each other, and are respectively opened at the lower part of the surge tank 14 with a positional relationship communicating with the primary intake passage 13a of the intake passage block 13. The primary intake passages 18, 18,... Communicating with the cylinders 2a, 2d, 3a, 3d pass through the surge tank 14 through the longitudinal side (front or rear) of the surge tank 14. Each of the two air chambers A and B communicates with the nearest air chamber. That is,
Those connected to the cylinders 2a and 2d are connected to an air chamber A located on the cylinder row 2 side, and those connected to the cylinders 3a and 3d are connected to an air chamber B located on the cylinder row 3 side. The primary intake passage 18 that communicates with the cylinders 2b, 2c, 3b, and 3c passes through the upper part of the surge tank 14 and is located on the other cylinder row side of the two air chambers A and B. Each room is in communication. That is, the cylinders 2b and 2c communicate with the cylinders 3b and 3c in the cylinder chamber B located on the side of the cylinder row 3 opposite to the cylinder row 2.
What is communicated with c is communicated with the air chamber A located on the side of the cylinder example 2 facing the cylinder row 3. The length of each primary intake passage 18 described above is the same as that of the intake passage block.
In the state where the length of the primary intake passage 13a in 13 is added, the inertia supercharging effect is set to be obtained in a low speed operation range where the engine speed is low. As described above, the primary intake passage 18 communicating with the cylinders in the same cylinder row is divided into the air chambers A and B for each cylinder because the ignition sequence of the engine 1 used in the present embodiment is considered. is there. The engine 1 of this embodiment has crankshafts in which crankpins are provided in four directions, each of which is shifted by 90 degrees with respect to the center of the crankshaft, and the ignition order of the cylinders is 2a-2b-3b.
The order of −2c−3c−3a−2d−3d is adopted. That is, the cylinders in the ignition order (for example, cylinder 2a
The primary intake passage 18 communicated with the cylinder 2b) is connected to an air chamber located on the opposite side of each cylinder (for example, the cylinder 2a).
In this case, the intake air can be supplied from the different air chambers to the cylinders having the same ignition sequence, by connecting the one for the cylinder to the air chamber A and the one for the cylinder 2b to the air chamber B). For this reason, one cylinder of the surge tank 14 can be alternately used for intake with another cylinder without interfering with intake of another cylinder at the time of low engine rotation. It is possible to suppress the occurrence of intake interference in a low rotation speed range due to the overlap of valve overlap times.

In order to attach the intake device of the multi-cylinder V-type engine thus configured to the engine 1, first, the intake pipe 12 and the intake passage blocks 13, 13 are attached to the bottom of the surge tank 14 with the assembling bolts 19, 20. Next, surge tank 14
And the intake passage block 13 are fixed to the engine 1 by tightening bolts 21 which penetrate through the both and fasten together. When the surge tank 14 and the intake passage block 13 are stacked and assembled as described above, not only can the assembly be performed easily, but also the two cylinder rows 2 and 3 can be rigidly connected to each other. Can be reinforced.
Since the control valve 15 is closed when the engine 1 is running at a low speed, the intake air supplied to the air chambers A and B of the surge tank 14 is supplied to the primary intake passage 18 and the intake passage block 13 of the surge tank 14. Is supplied to each cylinder through the primary intake passage 13a. In addition, since the control valve 15 is open at the time of high rotation, the intake air supplied to both air chambers A and B of the surge tank 14 is added to the above-described primary intake passages 18 and 13a, and a relatively short intake air is supplied. The air is supplied to each cylinder also through the secondary intake passage 13b of the passage block 13. In this way, when the engine 1 is at a low rotation speed, the intake is performed through a long intake passage, and when the engine 1 is at a high rotation speed, the air is also suctioned from a short intake passage. Can be obtained.

Therefore, as shown in this embodiment, the secondary intake passage 13b extends obliquely upward from the cylinder, and the primary intake passage 13a extends upward so as to bypass the axis of the valve shaft 16 of the control valve 15. As a result, the secondary intake passage 13b communicates with the lower part of the surge tank 14 from below, and the primary intake passage 13a passes through the side of the surge tank 14 and communicates with the internal air chamber. Therefore, the surge tank 14 can be positioned at a lower position in the V-shaped space while ensuring the length dimension of each intake passage. Further, since the secondary intake passage 13b communicates with the intake passage in the cylinder substantially linearly, the intake resistance can be reduced.

In this embodiment, of the primary intake passages 18 of the surge tank 14, those communicating with the cylinders 2a, 3b, 3c and 2d are respectively placed in the air chamber A of the surge tank 14 and the cylinders 3a, 2b, 2c and 3c. Although the example in which the communicating objects are respectively communicated with the air chambers B has been described, the present invention is not limited to such a limitation, and it is possible to change the communicating air chambers according to the ignition sequence of the engine to be used. it can.

Further, in the present embodiment, an example is shown in which the primary intake passage 18 is formed integrally with the surge tank 14, but both may be formed separately.

Further, in the present embodiment, an example in which a V-type eight-cylinder engine is used has been described. However, in the case of a V-type engine, effects similar to those of the present embodiment can be obtained regardless of the number of cylinders.

〔The invention's effect〕

As described above, the intake device for a multi-cylinder V-type engine according to the present invention has the secondary intake passage extending obliquely upward from the cylinder, and the primary intake passage extending along the axis of the valve rotation axis of the control valve. Since the secondary intake passage extends upward so as to make a detour, the secondary intake passage communicates with the lower portion of the surge tank, and the primary intake passage passes through the side of the surge tank and communicates with the internal air chamber. Therefore, the surge tank can be positioned at a low position in the V-shaped space while securing the length of each intake passage, so that the size of the entire engine can be reduced. Further, since the secondary intake passage communicates with the intake passage in the cylinder substantially linearly, the intake resistance can be reduced. Therefore, a large amount of intake air can be supplied when the engine is rotating at high speed, and the charging efficiency can be increased. further,
Since the primary intake passage can be prevented from interfering with the valve rotation shaft, it is possible to prevent the valve rotation shaft from penetrating through the primary intake passage and increasing intake resistance.

[Brief description of the drawings]

FIG. 1 is a front view showing a main part of an intake device of a multi-cylinder V-type engine according to the present invention cut away, and FIG. 2 is a plan view showing an enlarged intake device of a multi-cylinder V-type engine according to the present invention. , Third
FIG. 4 is a side view, and FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1 ... Engine, 2,3 ... Cylinder row, 5 ... Primary port, 6 ... Secondary port, 10 ... Intake device, 13 ...
... intake passage block, 13a, 18 ... primary intake passage, 13b ... secondary intake passage, 14 ... surge tank, 14a ... partition plate, 15 ... control valve, 16 ... valve shaft.

Claims (1)

(57) [Claims] In a multi-cylinder V-type engine, a primary port and a secondary port opened to a V-shaped space side of each cylinder are respectively connected to a surge tank in the V-shaped space via a primary intake passage and a secondary intake passage. In the intake device for a multi-cylinder V-type engine, which is communicated with and is provided with a control valve that is closed when the engine speed is low and opens when the engine speed is high in the secondary intake passage, the secondary intake passage extends obliquely upward from the cylinder. An intake device for a multi-cylinder V-type engine, wherein the primary intake passage extends upward so as to bypass an axis of a valve rotation shaft of the control valve.