JPH04362268A - Surge tank of internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a surge tank of an internal combustion engine which is lightweight and secures large capacity easily. CONSTITUTION:A surge tank 3 is constituted of an assembly part of a surge tank lower side first part 8 which is obtained by press-molding an iron plate to a prescribed shape, surge tank lower side second part 9, and a surge tank cover part 10, and a sealing member 11 and a gasket 14 are interposed in a joint part between the parts, and airtightness is secured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surge tank for an internal combustion engine, and more particularly to a surge tank provided upstream of a throttle valve in a so-called independent throttle internal combustion engine, in which an independent throttle valve is installed in each intake passage of each cylinder. .

0002

[Prior Art] Generally, a surge tank is connected to the intake manifold of an internal combustion engine to prevent intake pulsation of the engine.
For example, as seen in Japanese Utility Model Application Publication No. 60-23239, the structure is formed integrally with the intake manifold by a manufacturing method such as casting. The surge tank disclosed herein has an EGR passage therein, and has a complicated structure in which the discharge opening opens toward the downstream side in the direction of air flow within the surge tank.

0003

[Problems to be Solved by the Invention] In so-called independent throttle internal combustion engines in which an independent throttle valve is installed in each intake passage of each cylinder, the throttle valve is normally attached to the intake manifold extending from the engine body (cylinder head). The surge tank is arranged on the upstream side of the intake air with respect to the throttle bodies.

Therefore, in an internal combustion engine in which the throttle body is provided between the intake manifold and the surge tank, the intake manifold and the surge tank cannot be integrally manufactured by casting as in the prior art described above. Furthermore, the weight of the engine increases as the number of throttle bodies increases.

[0005] In such an internal combustion engine, if the capacity of the cast surge tank is further increased in order to obtain an inertial supercharging effect in the low and medium speed range of the engine, the weight of the engine will further increase and the engine performance will be significantly reduced. There is a problem.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide a large-capacity surge tank for independent throttle internal combustion engines whose weight tends to increase without significantly increasing the weight.

[0007]

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, a surge tank of an internal combustion engine is provided on the intake upstream side of each throttle valve separately provided corresponding to each cylinder of the internal combustion engine. The present invention provides a surge tank characterized in that the surge tank is formed by joining a plurality of press-formed metal plates together via a sealing means.

[0008]

[Operation] Since the surge tank is formed by combining press-formed metal plates, its thin plate structure makes it lightweight.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the surge tank according to the present invention will be described below with reference to the drawings. Figure 1 is a side view of the engine showing the positional relationship of the surge tank with respect to the internal combustion engine body (engine body), and 1 is an air flow meter located at the most upstream side of the intake system and measures the amount of intake air taken into the engine. , 2 is an air cleaner hose that purifies the air taken in, 3 is a surge tank connected to this air cleaner hose 2 and distributes intake air to each cylinder, and 4 is an engine body located on the back side of this surge tank 3.

FIG. 2 is an external view of the surge tank 3 viewed from the direction of arrow II in FIG. 1, and FIG. 3 is a sectional view showing the inside of the surge tank. As is clear from these figures, an intake manifold 5 having intake passages corresponding to each cylinder extends from the engine body 4 toward the surge tank 3, and between the intake manifold 5 and the surge tank 3,
A throttle body 7 is provided therein to movably accommodate a throttle valve 6 corresponding to the intake passage.

[0011] In the intake system configured as above,
According to this embodiment, the surge tank 3 connected to the throttle body 7 is provided by assembling three press-formed metal plate parts.

[0012] This metal plate component may be provided simply by pressing an iron plate, or may be provided by, for example, a so-called multi-layer vibration damping sandwich structure in which a resin material such as polypropylene is sandwiched between two thin iron plates. It can also be obtained by pressing a material into a predetermined shape, and in terms of its structure, in this embodiment, the lower first part is attached to the flange part 7a of the throttle body 7.
It consists of a part 8, a second lower part 9 joined to the first lower part 8, and a surge tank cover part 10 placed over both of these parts.

Regarding the joining of the lower first part 8 and the lower second part 9, as shown in FIG. 4, which is a cross section of the joined part,
The edge 8a of the lower first part 8 that has been folded back to the outside is inserted into the edge 9a of the lower second part 9 that has also been folded back to the outside but is also folded back inward, with the sealing material 11 interposed. The two parts are joined by mating surfaces of a so-called hemming structure, and the structure is such that air does not leak to the outside from the joint of these two parts.

As shown in FIG. 3, the surge tank lower assembly 12 consisting of the first lower part 8 and the second lower part 9 assembled in this way is attached to the flange portion 7a of the throttle body 7. In this embodiment, the flange portion 13a is placed on the assembly 12 during this assembly.
An intake pipe 13 equipped with a bolt 14 is abutted against the bolt 14, and the surge tank lower assembly 12 and the intake pipe 13 are integrally connected to the flange portion 7a of the throttle body 7 by the bolt 14.

As is clear from the figure, this intake pipe 13 is designed to obtain an inertial supercharging effect in the low and medium speed range of the engine by extending the intake passage upstream of the throttle valve 6. As shown in FIG. 5, the shape is curved downward from the flange 7a of the throttle body 7, and there are a plurality of them (four in the figure) corresponding to the number of cylinders.
It is made of, for example, a resin material to reduce weight.

In this embodiment, the surge tank cover 10 is mounted on the surge tank lower assembly 12 with the intake pipe 13 and the surge tank lower assembly 12 attached to the throttle body 7 in this manner. For assembly, the peripheral portion 12 of the surge tank lower assembly 12 is bent outwardly.
One surge tank 3 is provided by abutting the peripheral edge portion 10a of the surge tank cover 10 against the surge tank a through a gasket 14 as a sealing means, and fastening both together with a plurality of bolts 15.

As described above, according to this embodiment, the surge tank, which has been a cast part such as aluminum die-casting, can be
Since it is constructed from a lightweight member made of iron plates, it is possible to increase the volume of the surge tank without significantly increasing the weight, thereby improving the inertial supercharging effect in the low and medium speed range of the engine. In addition, the surge tank 3 in this embodiment has a sealing material 1 at the joint between the component parts.
1 and the gasket 14, gas leakage, which is common in such assemblies, is unlikely to occur, and a surge tank with sufficient airtightness can be provided.

[0018]

[Effects of the Invention] As explained above, according to the present invention, the surge tank is formed by combining press-formed metal plates, so its thin plate structure makes it lighter than a cast surge tank, and therefore larger. It becomes possible to increase the capacity and improve the performance of the internal combustion engine.

[Brief explanation of drawings]

FIG. 1 is a side view of an engine equipped with a surge tank according to the present invention.

FIG. 2 is a rear view of the surge tank seen from the direction of arrow II in FIG. 1;

FIG. 3 is a sectional view of the surge tank taken along line III-III in FIG. 1;

FIG. 4 is an enlarged cross-sectional view of the surge tank joint along line IV-IV in FIG. 1;

FIG. 5 is an external perspective view showing the inside of the surge tank shown in FIG. 1, with a portion thereof cut away.

[Explanation of symbols]

3...Surge tank 6...Throttle valve 8...Surge tank lower first part 9…Surge tank lower second part 10...Surge tank cover parts 11...Sealing material 14...Gasket

Claims (1)

[Claims] 1. A surge tank for an internal combustion engine, which is provided on the intake upstream side of each throttle valve that is separately provided corresponding to each cylinder of the internal combustion engine, the surge tank comprising a plurality of press-formed metal plates. A surge tank characterized in that it is formed by joining together via a sealing means.