JPH0227118A - Engine intake device - Google Patents

Abstract

PURPOSE:To suppress a surge tank from being vibrated by bending an intake pipe connected to a cylinder head at one end toward the underside of an engine and providing the surge tank at a connection between an engine body and the other end of the intake pipe. CONSTITUTION:An intake pipe 3 connected to a cylinder head 1 at one end is bent toward the underside of an engine. The other end of the intake pipe 3 is connected to the engine body and a surge tank 10 is formed integrally with the engine body at that connection, whereby the engine can be made more compact and the vibration of the surge tank can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for an engine equipped with a surge tank, and more particularly to a mounting structure for a surge tank and an intake manifold.

(Prior Art) Conventionally, in an engine intake system equipped with a surge tank, in order to suppress vibration of the surge tank that occurs due to vibration of the engine body and to ensure an independent intake passage length on the downstream side of the surge tank, For example, Utsukai Showa 57-75158
As disclosed in the above publication, a surge tank mounting structure has been proposed in which the surge tank is integrally formed in the cylinder head cover of an engine.

However, if the surge tank is integrally formed in the hendkaher, even if it is possible to suppress the vibration of the surge tank, the surge tank or the independent intake passage on the downstream side of the surge tank will be placed above the cylinder cover. As a result, the overall height of the engine increases, raising the center of gravity, making it impossible to sufficiently reduce engine vibration, while also failing to achieve a low bonnet, which poses undesirable problems from both aerodynamic and design perspectives.

(Object of the Invention) Therefore, an object of the present invention is to provide an engine intake device that can suppress the vibration of a surge tank while making the engine more compact. The intake device extends an intake pipe whose one end is connected to the cylinder head in a curved state downward from the engine, and the other end of the intake pipe is connected to the cylinder head at a lower side than the part where the one end is connected to the cylinder head. It is characterized in that it is connected to the engine body at this connection point and that a surge tank is integrally formed with the engine body at this connection portion.

(Effects of the Invention) According to the present invention, the surge tank is formed integrally with the engine body at a position lower than the opening of the intake port in the cylinder head. Shaking of the surge tank due to vibration can be suppressed.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a DOHC type series 4, which is the first embodiment of the present invention.
This is a vertical cross-sectional view of the main parts of a cylinder engine.A cylinder head 1 is formed with an intake boat 3 and an exhaust bow 1-4 that open into the combustion chamber 2 of each cylinder. An intake valve 5 and an exhaust valve 6 for respectively opening and closing are arranged in a figure 7 shape with a predetermined angle.

At the top of the cylinder head 1, there are an intake valve 5 and an exhaust valve 6.
Two camshafts 8.9 are pivotally supported to drive the camshafts through hydraulic lash adjusters 7, respectively.

On the side surface of the intake side of the cylinder head 1, a volume portion extending in the cylinder arrangement direction is integrally formed adjacent to the lower part of the four-wood intake boat 3 to constitute a surge tank 1°. 1o and the intake boats 3 of each cylinder, an intake manifold 11 as shown in FIG. 2 is installed. This intake manifold 11 includes four U-shaped intake pipes 13 that form independent intake passages 12 that communicate between the surge tank 10 and the intake boat 3 of each cylinder, and both ends of these intake pipes 13. It consists of a mounting flange 14 (171I) for connecting to the cylinder head 1.As is clear from FIG. 2 forms a plane P, and the intake manifold l in FIG. Four elliptical openings 15 that match the openings on the plane P of the boat 3 are formed as one end of each independent intake passage 12 in alignment in the cylinder arrangement direction, and each intake pipe 13 Extends diagonally upward from position 15 to the side opposite to the cylinder head 1 side,
Next, the engine curves downward, and then the cylinder head 1
It curves toward the side and is connected to the lower part of the flange 14 in a horizontal state. And on the flange 14,
Four circular openings 16 are located below the opening 15,
They are formed as the other end of each independent intake passage 12 and aligned in the cylinder arrangement direction.

Further, the flange 14 has a mounting hole 18 for mounting the fuel injector 17 at each opening 1 on the upper side.
5, and the fuel injector 17 is attached to the mounting hole 18 with its axis perpendicular to the plane P, and the fuel injector 17 is attached to the U-shaped intake pipe 13 of the intake manifold 11. It is configured to inject fuel into each intake port 3. A fuel distribution pipe 19 connects the heads of each fuel injector 17 and extends in the cylinder arrangement direction. In this embodiment, as is clear from FIG. 2, the openings 16 forming the ends of the independent intake passages 12 in the intake manifold 11 on the surge tank 10 side are not located directly below the openings 15, but are located relative to the openings 15. It is located at a laterally offset position. When the intake manifold 1■ is viewed from the direction A in FIG. 1 (the state shown in FIG. 2), each intake pipe 13 is curved so as not to overlap the fuel injector 17, thereby improving the serviceability of the fuel injector 17. I have to. surge tank 10
A throttle body 20 is attached to the center of the throttle body 20 as shown by the imaginary line in FIG.
A common intake passage (not shown) on the upstream side is connected to.

The cylinder head 1 in which the surge tank 10 is thus integrally formed and the intake manifold 11 is attached is fixed to the upper end of the cylinder block 21 via the head gasket 22. Note that 23 is a bottom cover that covers the upper surface of the cylinder head 1.

The above is the configuration of the first embodiment of the present invention. According to this embodiment, the intake manifold 11, whose one end is connected to the cylinder head l, is extended in a curved state toward the lower side of the engine, The other end of the manifold 11 is connected to the cylinder head 1 below the part where the one end is connected to the cylinder head 1, and the surge tank 10 is integrally formed with the cylinder head 1 at this connection part. , it is possible to secure the passage length of the independent intake passage 12 on the downstream side of the surge tank 10, and also to reduce the height of the engine, making the engine more compact and suppressing swinging of the surge tank due to engine vibration. can do.

Further, according to this embodiment, since the connection surface of the intake manifold 11 to the intake port 3 and the connection surface to the surge tank 10 are on the same plane P, the cylinder head 1
The workability of the intake manifold 11 is also good.

Further, according to this embodiment, the fuel distribution pipe 19 is arranged inside the curved intake pipe 12 of the intake manifold 11, and the intake pipe 12 functions as a protector for the fuel distribution pipe 19. .

Furthermore, according to the present embodiment, the formation positions of the openings 15 and 16 at both ends of the independent intake passage 12 are offset in the lateral direction,
Since the intake pipe 12 and the fuel injector 17 are prevented from overlapping, the serviceability for the fuel injector 17 is good.

Next, FIG. 3 shows a second embodiment of the present invention. Parts corresponding to those in FIG. Volume part 10a
In addition, a volume portion 10b is integrally formed on the cylinder block 21 side, and these two volume portions lOa and 10b constitute a surge tank 10, which is different from the one shown in FIG. Therefore, the head gasket 22 is extended toward the surge tank 10, and this extended portion 22a seals the connection surface between the volumes 10a and 10b.

It is clear that the second embodiment of the present invention also provides the same effects as the first embodiment described above.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a longitudinal sectional view showing the main parts of the first embodiment of the present invention;
FIG. 2 is a side view of the intake manifold viewed from direction A in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view showing the main parts of a second embodiment of the present invention. 1-Cylinder head 3=-Intake port 5-Intake valve 10-Surge tank 11-Intake manifold 12-Independent intake passage 13-Intake pipe 14-Mounting flange 16-Opening fuel injector Fuel distribution pipe Cylinder block

Claims (1)

[Claims] One end of the intake pipe is connected to the cylinder head, and the other end of the intake pipe is extended in a curved manner toward the bottom of the engine.
An intake device for an engine, wherein the one end is connected to the engine body at a position lower than a portion connected to the cylinder head, and a surge tank is integrally formed with the engine body at this connection portion.