JPH0217707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for an engine, and more particularly to an improvement in an intake system equipped with a surge tank that defines an intake expansion chamber in an intake passage. .

(Prior art) Recently, in the intake system of engines, especially automobile engines, a surge tank is arranged in the engine's intake system in order to improve the filling efficiency due to the dynamic effect of intake air. There is one in which these are connected by separate intake pipes.

In this type of intake system, a long independent intake pipe is used to improve filling efficiency, especially in the low load range. The design has a curved shape that bulges out to the side of the engine to ensure a smooth flow of intake air, that is, to solve the problem of intake resistance and to reduce the size of the device.
(Refer to Publication No. 175666).

(Problems to be Solved by the Invention) However, in this type of intake system, the independent intake pipe that bulges out to the side of the engine occupies the space on the side of the engine in the limited engine room. I have a problem.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an intake system for an engine that minimizes the occupation ratio of an independent intake pipe in a space to the side of the engine without increasing intake resistance.

(Means and effects for solving the problem) The present invention focuses on the arrangement relationship between the surge tank and the independent intake pipe, and provides one longitudinal end of the surge tank that is arranged above the engine body and extends in the cylinder arrangement direction. In addition to placing it higher than the other end,
An independent intake pipe is shaped so that it extends away from one side of the surge tank and then curves toward one side of the engine body. The configuration is such that they are placed in close proximity.

With this configuration, the length and bend of the independent intake pipes connected to each cylinder are the same as before, but the proportion of the space occupied by the independent intake pipes in the side space of the engine can be reduced toward one end of the engine. can do.

(Example) In Figures 1 to 3, 1 is an engine body, and the engine body 1 is an in-line 4-cylinder type and is placed vertically in the engine room A, that is, the cylinder arrangement direction is oriented toward the front-rear direction of the vehicle body. It is listed as such. This engine body 1 is composed of a cylinder block 2, a cylinder head 3, a cylinder head cover 4, etc., and each cylinder 5 of the engine body 1 has
Two intake ports 6 and 7 formed in the cylinder head 3 are closed, and each intake port 6 and 7 is provided with an intake valve (not shown), respectively.

The first and second intake ports 6 and 7 are branched within the cylinder head 3, and the upstream end thereof is a common intake port 8, which is connected to one side 3a of the cylinder head 3, that is, one side of the engine body 1. It is opened on the side surface 1a.

The intake passage connected to the common intake port 8 includes, in order from the intake port 8 side, individual independent intake pipes 9,
It is composed of a surge tank 10 defining an intake expansion chamber, a throttle body 11, a common intake pipe 12, and an air cleaner (not shown), and each of the independent intake pipes 9
A fuel injection valve 13 is disposed at the end connected to the cylinder head 3.

The surge tank 10 is disposed above the engine body 1, has a minimum volume necessary to obtain an intake dynamic effect, and has an equal longitudinal cross section in the longitudinal direction. And surge tank 1
0 is arranged so that its longitudinal direction is in the cylinder arrangement direction, and the rear end 10a of the surge tank 10 is
The surge tank 10 is arranged at an inclination such that it is higher than the front end 10b (see FIG. 2), and the inclination angle θ of the surge tank 10 is approximately equal to the inclination angle of the bonnet lines B and L.

On one side surface 10c of the surge tank 10, upstream independent intake pipe sections 14 that extend independently are arranged in parallel in the cylinder arrangement direction. Each branch pipe 15a of the intake manifold 15 is connected to the downstream end of the upstream independent intake pipe section 14, and each branch pipe 14a has a shape that extends in a direction away from 10c and then hangs downward. Each of them is connected to an intake port 8 that opens on one side 3a of the cylinder head 3.
That is, the upstream independent intake pipe portion 14 integrally formed with the surge tank 10 and each branch pipe 15a of the intake manifold 15 constitute an independent intake pipe 9 that connects the surge tank 10 and the intake port 8. , the independent intake pipe 9 extends away from one side 10c of the surge tank 10, then extends downward, and finally reaches the one side 3a of the cylinder head 3.
It has a curved shape that extends toward. and,
The independent intake pipes 9-1, 9-2, 9-3, and 9-4 arranged in order from the front end in the cylinder arrangement direction have almost the same pipe length, and the independent intake pipes are located at the rear end side in the cylinder arrangement direction. 9, that is, as it goes toward the independent intake pipe 9-4, it passes through a position closer to one side 1a of the engine body 1. In FIG. 3, reference numeral 16 is a master bag attached to the dash panel 17. As shown in FIG.

In the above configuration, the surge tank 10 is arranged to be inclined along the bonnet lines B and L, and the side surface 1a of the engine body 1 is closer to the independent intake pipe 9-4 located at the rear end in the cylinder arrangement direction. Since the intake pipes 9-1 to 9-4 are arranged close to each other, the lengths of all the independent intake pipes 9-1 to 9-4 can be easily made equal. Further, the occupation ratio in the engine room A of the independent intake pipe 9 that bulges out toward the side 1a of the engine body 1 can be made smaller as it goes toward the independent intake pipe 9-4. In other words, by tilting the surge tank 10, the bonnet line
By effectively utilizing the dead space sandwiched between the BL and the surge tank 10, the bulge of the independent intake pipe 9 is made smaller as it goes toward the rear end of the engine body 1, thereby easily securing space on the side of the engine. be able to.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, without causing problems such as an increase in intake resistance,
Since the bulge of the independent intake pipe that bulges out to the side of the engine body can be made smaller as it goes toward one end in the cylinder arrangement direction, it is possible to reasonably secure a space on the side of the engine in the engine room.

[Brief explanation of drawings]

FIG. 1 is a partial front view of the engine body viewed from the front, FIG. 2 is a side view of the engine body viewed from the other side, and FIG. 3 is a plan view of the inside of the engine room viewed from above. 1: Engine body, 1a: One side of the engine body, 3: Cylinder head, 5: Cylinder, 8: Common intake port, 9: Independent intake pipe, 10: Surge tank, 10a: Rear end of surge tank, 10b: Surge Front end of tank, 10c: one side, B, L: bonnet line, A: engine room.

Claims (1)

[Scope of Claims] 1. A surge tank arranged above a multi-cylinder engine body and extending in the cylinder arrangement direction and an intake port of each cylinder are connected by independent intake pipes arranged in parallel in the cylinder arrangement direction, and the In an engine intake system, the intake pipe is shaped to extend away from one side of the surge tank and then curve toward one side of the engine body, the surge tank having one end higher than the other end. An intake system for an engine, characterized in that the independent intake pipe is arranged at a position closer to one side of the engine body as the independent intake pipe is located closer to one end side in the cylinder arrangement direction. .