JPH06235357A - Intake device for engine - Google Patents

Abstract

PURPOSE:To improve the workability in the forging work for an intake manifold by forming a compact engine by diminish the external shape of the intake manifold. CONSTITUTION:A surge tank 24 and a branched pipe 26 are formed separately, and auxiliary branched pipe parts 30-1-30-4 which project into the surge tank are installed in order to secure the nearly equal length of an intake passage leading to a combustion chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an engine, and more particularly to supplying intake air to a plurality of combustion chambers provided in the engine through an intake manifold composed of a surge tank and a plurality of branch pipes. In addition, the present invention relates to an intake device for an engine in which a surge tank is offset.

[0002]

2. Description of the Related Art Conventionally, in an engine, a throttle valve provided in an intake passage is opened and closed by operating an accelerator pedal to adjust an intake amount.

Recently, an intake device formed by two intake passages is adopted so that appropriate output characteristics can be obtained in a wide operating range of the engine from low speed to high speed in accordance with the load amount. There is a case.

An intake manifold is used to feed intake air from the upstream side of the intake system to a plurality of combustion chambers provided in the engine. This intake manifold is formed by a surge tank and a branch pipe.

As another engine intake device, as disclosed in Japanese Examined Patent Publication No. 2-17707, a surge tank disposed above the multi-cylinder engine body and extending in the cylinder arrangement direction, and intake air of each cylinder are provided. The ports are connected by independent intake pipes juxtaposed in the cylinder arrangement direction, and the independent intake pipes extend in a direction away from one side surface of the surge tank, and then are curved toward one side surface of the engine body. In the intake device, the surge tank is arranged so as to be inclined so that one end of the surge tank is higher than the other end, and the independent intake pipe is closer to one side surface of the engine body as far as the independent intake pipe is located on the one end side in the cylinder arrangement direction. Some were placed in position.

[0006]

By the way, the lengths of the respective branch pipes of the intake manifold have to be made equal to perform the inertial intake.

As shown in FIGS. 9A and 9B, the surge tank 124 of the intake manifold 122 and the engine 10 are
When the two cylinder heads 106 are arranged without being offset, the branch pipes can be easily equalized in length.

However, depending on the shape of the engine room (not shown) and the like, the surge tank 224 and the cylinder head 206 may be arranged offset from each other. In such a case, as shown in FIGS. 10 (a) and 10 (b), the curvature ratio of each branch pipe 226 may be changed,
As shown in FIG. 1 (a) and FIG. 11 (b), the surge tank 22
4 is offset from the other end in the front-rear direction by a predetermined distance a, or as shown in FIGS. 12 to 14, the other end is offset from the one end of the surge tank 224 in the vertical direction by a predetermined distance b. By doing so, each branch pipe 226 was made equal in length.

Further, in recent years, since the comfortability and the height of the vehicle have been required to be improved in the same body size, the engine room is narrowed, and in all the above-mentioned measures, the equal lengths of the respective branch pipes are used. However, the size of the engine is determined, which is disadvantageous in practical use.

Further, in the measures shown in FIGS. 10 (a) and 10 (b), when the EGR distribution pipes (not shown) are arranged because the branch pipes 226 have different curvature rates. In addition, there is a problem that the shape of the EGR distribution pipe (not shown) is complicated.

[0011]

In order to eliminate the above-mentioned inconvenience, the present invention introduces intake air into a plurality of combustion chambers provided in an engine through an intake manifold consisting of a surge tank and a plurality of branch pipes. In the intake device of the engine in which the surge tank is provided while offsetting the supply, the surge tank and the branch pipe are separately formed,
It is characterized in that an auxiliary branch pipe portion projecting into the surge tank is provided so that the intake passages to the respective combustion chambers have substantially the same length.

[0012]

According to the structure of the present invention, the intake air on the upstream side of the intake system flows into the surge tank, flows into the branch pipe through the auxiliary branch pipe portion in the surge tank, and from the branch pipe into the engine. Is being supplied to. At this time, since the lengths of the intake passages to the respective combustion chambers are made substantially the same, intake air having substantially the same inertia is supplied from the upstream side of the intake system to the respective combustion chambers.

[0013]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 8 show an embodiment of the present invention.

In FIG. 7, reference numeral 2 denotes an engine, 4 is a cylinder block, 6 is a cylinder head, 8 is a piston, 10 is a combustion chamber, 12 is an intake valve, and 14 is an exhaust valve. The intake valve 12 and the exhaust valve 14
Are provided in the intake port 16 and the exhaust port 18 of the cylinder head 6, and the intake / exhaust camshafts 20-1 and 20
The intake port 16 and the exhaust port 18 which are swung by -2 and communicate with the combustion chamber 10 are opened and closed.

An intake manifold 22 is connected to the intake port 16. This intake manifold 22
Has a surge tank 24 and a branch pipe 26. This intake manifold 22 is installed in the engine 2 from the upstream side of the intake system.
The intake air is supplied to a plurality of combustion chambers 10 provided inside.

Further, the surge tank 24 and the branch pipe 26
Are separately formed, and auxiliary branch pipe portions 30 projecting into the surge tank 24 are provided so that the lengths of the intake passages 28 to the respective combustion chambers 10 are made substantially the same.

More specifically, a plurality of, for example, four first to first
The fourth branch pipes 26-1 to 26-4 are formed. This 1st
As shown in FIG. 5, the fourth branch pipes 26-1 to 26-4 are formed so that the length thereof gradually increases from one side (right side in FIG. 5) to the other side (left side in FIG. 5). In addition, as shown in FIG. 6, they have substantially the same curvature rate.

When forming the surge tank 24,
In the surge tank 24, the first to fourth branch pipes 26-
First to fourth auxiliary branch pipe portions 30-corresponding to 1-26-4
1 to 30-4 are provided.

The first to fourth auxiliary branch pipe portions 30-1 to 30-3
As shown in FIG. 2, 0-4 are formed such that the amount of protrusion into the surge tank 24 from the one side (the right side in FIG. 2) to the other side (the left side in FIG. 2) becomes smaller in order. .

That is, the protrusion amount L1 of the first auxiliary branch pipe portion 30-1 and the protrusion amount L2 of the second auxiliary branch pipe portion 30-2,
The protrusion amount L3 of the third auxiliary branch pipe portion 30-3 and the protrusion amount L4 of the fourth auxiliary branch pipe portion 30-4 have a relationship of L1>L2>L3> L4.

When the intake manifold 22 is formed, the first branch pipe 26-1 having a smaller length and the first auxiliary branch pipe portion 30-1 having a larger protrusion amount are connected to each other. Similarly, the other second to fourth branch pipes 26-2 to 26-4 and the second to fourth
The auxiliary branch pipe parts 30-2 to 30-4 are connected to each other, and the first to fourth branch pipes 26-1 to 26 are connected to the first to fourth auxiliary branch pipe parts 30-1 to 30-4 from their upstream ends. The lengths of the intake passages to the respective combustion chambers 10 are made substantially the same by making the lengths of -4 to the downstream end portion substantially the same.

Next, the operation will be described.

The intake air on the upstream side of the intake system is the intake manifold 2
2 surge tank 24 flows into this surge tank 2
4 through the first to fourth auxiliary branch pipe portions 30-1 to 30-4 in the intake manifold 22.
1 to 26-4 are introduced into the first to fourth branch pipes 26.
It is supplied into the engine 2 from -1 to 26-4.

At this time, since the lengths of the intake passages 28 to the respective combustion chambers 10 are made substantially the same, intake air having substantially the same inertia is supplied from the upstream side of the intake system to the respective combustion chambers 20. .

As a result, the overall height and width of the intake manifold 22 can be reduced, the engine 2 can be made compact, and the space in the engine room (not shown) can be effectively used, which is practically advantageous.

Further, since the surge tank 24 of the intake manifold 22 and the first to fourth branch pipes 26- to 26-4 are separately formed, the workability of casting the intake manifold 22 can be improved. Manufacturing cost can be reduced, which is economically advantageous.

Further, in the surge tank 24, the first to fourth auxiliary branch pipe portions 30- projecting into the surge tank 24 are formed.
By providing 1 to 30-4, the intake manifold 22
The first to fourth branch pipes 26-1 to 26-4 can be formed to have substantially the same bending rate, and the EGR distribution pipe (not shown) can be easily arranged.

[0029]

As described above, according to the present invention, the surge tank and the branch pipe are separately formed, and the surge tank is provided in the surge tank so that the intake passages to the combustion chambers have substantially the same length. Since the projecting auxiliary branch pipe portion is provided, the outer shape of the intake manifold can be downsized, and the engine can be made compact, which is practically advantageous. Further, since the surge tank and the branch pipe are separately formed, the workability of casting work can be improved, the manufacturing cost can be reduced, and it is economically advantageous.

[Brief description of drawings]

FIG. 1 is a sectional view of an intake manifold showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the intake manifold taken along the line 〓-〓 of FIG.

3 is a cross-sectional view of the intake manifold taken along the line 〓-〓 of FIG.

FIG. 4 is a schematic explanatory view of an intake manifold.

FIG. 5 is a schematic plan view of an intake manifold.

FIG. 6 is a schematic side view of an intake manifold.

FIG. 7 is a sectional view of the engine.

FIG. 8 is a side view of the engine.

FIG. 9 (a) is a schematic plan view of an intake device for an engine showing a conventional technique of the present invention. (B) It is a schematic side view of the intake device of an engine.

FIG. 10 (a) is a schematic plan view of another engine intake device. (B) It is a schematic plan view of the intake device of another engine.

FIG. 11 (a) is a schematic plan view of another engine intake device. (B) It is a schematic side view of the other intake device of an engine.

FIG. 12 is a schematic plan view of an intake device for another engine.

FIG. 13 is a schematic side view of an intake system for another engine.

FIG. 14 is an enlarged explanatory view of an intake device for another engine.

[Explanation of symbols]

 2 engine 4 cylinder block 6 cylinder head 8 piston 10 combustion chamber 12 intake valve 16 intake port 22 intake manifold 24 surge tank 26 branch pipe 28 intake passage 30 auxiliary branch pipe section

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 19, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 9]

[Figure 10]

[Fig. 13]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Fig. 12]

FIG. 14

[Figure 7]

[Figure 8]

FIG. 11

Claims (1)

[Claims] 1. An intake device for an engine, wherein intake air is supplied to a plurality of combustion chambers provided in the engine through an intake manifold composed of a surge tank and a plurality of branch pipes, and the surge tank is offset. In the above, the surge tank and the branch pipe are separately formed, and an auxiliary branch pipe portion protruding into the surge tank is provided so that the lengths of the intake passages to the respective combustion chambers are substantially the same. Characteristic engine intake device.