JP2543347Y2 - Engine exhaust manifold - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust manifold for a multi-cylinder engine having a plurality of exhaust ports.

[0002]

2. Description of the Related Art As this type of exhaust manifold, an exhaust manifold having a branch pipe made of a pipe and a collective case made of a casting has been proposed from the viewpoint that both weight reduction and ease of manufacture can be satisfied. (JP-A-63-1
No. 70515).

[0003]

[Problems to be Solved by the Invention] However, if all the branch pipes are made of pipes as described above, it is possible to make the pipes thinner, but there is an anxiety in terms of strength. there were.

An object of the present invention is to provide an exhaust manifold of an engine which has sufficient strength and can be reduced in weight.

[0005]

In order to achieve the above object, the present invention is directed to a multi-cylinder engine exhaust manifold having a plurality of branch pipes connected to a plurality of exhaust ports of the engine. Are formed integrally with a casting together with a series of inlet and outlet flanges for the entire branch pipe, and the other part is formed of a metal pipe.

[0006]

According to the above construction, a large strength is ensured in the casting, and the strength distribution in the pipe branch pipe is reduced. In addition, the pipe can be made thinner and lighter by using a branch pipe.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 and 2 in which the present invention is applied to a three-cylinder engine, reference numerals 1a to 1c denote branch pipes connected to exhaust ports (not shown) of the engine.
1c are provided with an inlet flange 2 at the upstream end thereof, fixed to a cylinder block (not shown) of the engine via the inlet flange 2, and the downstream end is connected to the collective case 3 so as to be connected to each of the exhaust ports. The inflowing exhaust gas passes through the branch pipes 1a to 1c to join in the collecting case 3, and is connected to a downstream opening of the collecting case 3 via an outlet flange 4 provided integrally with the periphery of the opening. It was led to an exhaust catalyst (not shown).

[0008] Of the three branch pipes 1a to 1c, a middle branch pipe 1b and an assembly case 4 including an outlet flange 4;
A series of inlet flanges 2 for all branch pipes are integrally formed by casting. In the figure, reference numeral 5 denotes a bracket for attaching a hot air cover.

On the other hand, the two branch pipes 1a and 1c on both sides are
It is formed in a curved shape with a metal pipe such as stainless steel and welded to the inlet flange 2 and the collecting case 3 at the respective upstream and downstream ends.

[0010] With this configuration, sufficient strength is ensured in the casting branch pipe 1b and the collecting case 3 connecting the inlet flange 2 and the outlet flange 4, and the branch pipes 1a and 1c made of metal pipes are secured. Strength sharing is reduced. Accordingly, the branch pipes 1a and 1c can be made as thin as possible, and the weight of the entire manifold can be reduced.

Further, since the collective case 3 and the inlet flange 2 are made of casting, the shape of the welded portion and the metal pipe (1a,
The molding of 1c) can be simplified, and the manufacture of the manifold becomes easy.

FIG. 3 shows another embodiment in which the present invention is applied to a four-cylinder engine. This means that the four branch pipes 1 converged into a pair at each downstream end to avoid exhaust interference due to the engine explosion sequence.
a to 1d, a pair of central branch pipes 1b and 1c and a series of inlet flanges 2 and outlet flanges 4 for all the branch pipes are integrally formed by casting, while another pair of both side pipes is formed. In this example, branch pipes 1a and 1d are formed of metal pipes and welded to an inlet flange 2 and an outlet flange 4, respectively. In the figure, reference numeral 5 denotes a bracket for mounting the hot air cover, and reference numeral 6 denotes a boss hole for mounting the hot air cover.

According to this embodiment, the same operation and effect as those of the previous embodiment can be obtained.

It should be noted that the present invention is not limited to the above embodiments, and various changes can be made without departing from the scope of the present invention.

[0015]

As described above, according to the present invention, a part of all branch pipes is integrally formed with a series of inlet and outlet flanges for all branch pipes by casting, and other parts are formed. Is formed by a metal pipe, it is possible to provide an exhaust manifold that has sufficient strength, can be measured, and is easy to manufacture.

[Brief description of the drawings]

FIG. 1 is a bottom view of an exhaust manifold showing one embodiment of the present invention.

FIG. 2 is a perspective view of the exhaust manifold.

FIG. 3 is a perspective view of an exhaust manifold showing another embodiment of the present invention.

[Explanation of symbols]

 1a to 1d Branch pipe 2 Inlet flange 3 Assembly case 4 Outlet flange

Claims (1)

(57) [Scope of request for utility model registration] 1. An exhaust manifold for a multi-cylinder engine having a plurality of branch pipes connected to a plurality of exhaust ports of an engine. An exhaust manifold for an engine, wherein the exhaust manifold is formed integrally with a casting, and the other part is formed of a metal pipe.