JPH05171932A - Exhaust manifold and its manufacture - Google Patents

Abstract

PURPOSE:To reduce weight of a manifold and carry out heat resistant or ther mal insulative coating treatment on an inner surface of a passage by separately manufacturing an upper member and a lower member across a surface which passes an exhaust port, and connecting the members to each other through a common surface for structuring an exhaust manifold. CONSTITUTION:An exhaust manifold is composed of an upper member 1 and a lower member 2 respectively having connecting flanges 1a, 2a formed by press working. Semicircular ports are formed on the upper and lower members 1, 2, which ports respectively composes upper and lower halves of an internal combustion side exhaust port 11. An exhaust pipe side exhaust port 12 is formed on the lower member 2. The upper and lower members 1, 2 are previously and separately prepared by press working or drawing, while a straightening vane 3 is arranged on the lower member 2. The upper and lower members 1, 2 are connected to each other by means of the respective connecting flanges 1a, 2a. Flanges 4, 5 are then fitted into time exhaust ports 11, 12. It is therefore possible to reduce weight and treat an inner surface of a passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for an exhaust pipe of an internal combustion engine. The present invention relates to an improvement of an exhaust manifold that collects exhaust gas of a multi-cylinder internal combustion engine into a single pipe.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, it has been general to integrally form by casting. Alternatively, it is also known to bend a pipe material into a predetermined shape and weld an internal combustion engine side flange and an exhaust port side flange.

[0003]

Since the above-mentioned conventional exhaust manifold is integrally formed by casting or uses a pipe material, the inside of the exhaust gas passage is coated with a heat resistant material or a heat insulating material. In addition, when forming by casting, there is a limit to thinning the meat due to the flow of molten metal. Further, when a pipe material is used, the total length becomes long because it is restricted by the bending radius of the pipe material, and there is a problem that the weight cannot be reduced in any case.

The present invention solves such a problem, and provides an exhaust manifold capable of reducing the weight and coating the exhaust gas passage with a heat-resistant material or a heat insulating material, and a method of manufacturing the same. To aim.

[0005]

According to the present invention, in an exhaust manifold whose inlet side is connected to each exhaust port of an internal combustion engine having a plurality of cylinders and whose outlet side is connected to one silencer, the exhaust manifold passes through substantially the center of each exhaust port. It features a structure joined by faces.

The upper member and the lower member can be separately manufactured with the surface passing through the exhaust port as a boundary, and the upper member and the lower member can be joined to each other, and the upper member and the lower member can be manufactured by sheet metal working, respectively. Thus, the wall surface of each exhaust passage of the upper member and the lower member can be coated with a heat insulating material.

[0007]

[Function] The upper member and the lower member are separated from each other with the surface passing through the center of the exhaust port as a boundary and individually molded. If necessary, a rectifying plate for improving the flow of the exhaust gas is attached, The wall surface is coated with heat insulating material or heat resistant material, and the divided surfaces are joined by welding. The upper member and the lower member are formed by pressing a steel plate or sheet metal working.

As described above, since the steel plate which can be manufactured at low cost and which is thin and has sufficient strength can be used, the weight can be remarkably reduced, and further, the upper member and the lower member are separated. As it is molded, it can be subjected to thermal barrier coating on the inner surface, additional processing such as rusting, and other necessary inner surface treatment. Further, since the steel sheet rolled according to a certain standard is used, the quality is uniform and therefore the yield can be improved.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. 1 (a) is a plan view showing the structure of an exhaust manifold in the embodiment of the present invention, FIG. 1 (b) is a front view and a partially enlarged view showing the structure of the exhaust manifold in the embodiment of the present invention, and FIG. 1 (c). Is a side view of the exhaust manifold in the embodiment of the present invention,
FIG. 2 (a) is a front view of an upper member according to an embodiment of the present invention, FIG.
FIG. 3B is a plan view of the upper member of the exhaust manifold of the present invention, FIG. 3A is a front view of the lower member of the exhaust manifold of the present invention, and FIG. 3B is the embodiment of the present invention. FIG. 5 is a plan view of a lower member according to an example exhaust manifold.

As shown in FIG. 1, the exhaust manifold of the present invention is composed of an upper member 1 and a lower member 2,
Joining flanges 1a and 2a are formed on the outer peripheries of the upper member 1 and the lower member 2 by press working. Further, the upper member 1 is formed with a semi-circular opening 1b which constitutes the upper half of the internal combustion engine side exhaust port 11 shown in FIG. 2 by press working, and the lower member 2 is formed with the lower half of the internal combustion engine side exhaust port 11. The semi-circular port 2b and the exhaust pipe side exhaust port 12 that configure the above are formed from a pipe material.

The upper member 1 and the lower member 2 thus configured are separately formed by press working or sheet metal working, and the current plate 3 is attached to a predetermined position of the lower member 2 by welding. The heat insulating material, the heat resistant material, or the stainless steel powder is coated by thermal spraying in accordance with predetermined specifications. Operations on these inner surfaces can be easily performed because the upper member 1 and the lower member 2 are in the open state.

The upper member 1 shown in FIG. 2 and the lower member 2 shown in FIG. 3 whose inner surfaces have been processed and treated are joined at the surfaces of the joining flanges 1a and 2a, and the entire outer circumference thereof is welded. Are joined together. After joining, the flanges 4 are fitted into the exhaust ports 11 of the internal combustion engine system and fixed by welding, and similarly, the flanges 5 are fitted and welded to the exhaust pipe side exhaust ports 12.

[0013]

As described above, according to the present invention, since it is possible to use a steel sheet which is inexpensive, thin and has sufficient strength, it is possible to significantly reduce the weight. Further, since the upper member and the lower member are divided and molded, it is possible to easily perform processing or processing on the inside, and since the steel sheet rolled according to a certain standard is used, the quality becomes uniform, There is an effect that the yield can be improved.

[Brief description of drawings]

1A is a plan view showing the structure of an exhaust manifold in an embodiment of the present invention, FIG. 1B is a front view and a partially enlarged view showing the structure of an exhaust manifold in an embodiment of the present invention, and FIG. FIG. 3 is a side view of an exhaust manifold, a shape of a flange, and a partially enlarged view of the embodiment of the invention.

FIG. 2A is a front view of an upper member of an exhaust manifold of the present invention, and FIG. 2B is a plan view of an upper member of an exhaust manifold of the present invention.

3A is a front view of a lower member of an exhaust manifold of the present invention, and FIG. 3B is a plan view of a lower member of an exhaust manifold of the present invention.

FIG. 4 is a diagram showing a configuration of an exhaust manifold in a conventional example.

[Explanation of symbols]

 1 Upper Member 1a, 2a Joint Flange 1b, 2b Semicircular Port 2 Lower Member 3 Rectifier Plate 4, 5 Flange 11 Internal Combustion Engine Side Exhaust Port 12 Exhaust Pipe Side Exhaust Port

Claims (4)

[Claims] 1. An exhaust manifold whose inlet side is connected to each exhaust port of an internal combustion engine having a plurality of cylinders and whose outlet side is connected to one silencer, characterized by being joined by a surface that passes through substantially the center of each said exhaust port. And an exhaust manifold. 2. A method of manufacturing an exhaust manifold in which an upper member and a lower member are separately manufactured with a surface passing through an exhaust port as a boundary, and the surfaces are joined together. 3. The method for manufacturing an exhaust manifold according to claim 2, wherein the upper member and the lower member are manufactured by sheet metal working. 4. The method of manufacturing an exhaust manifold according to claim 2, wherein the exhaust passage wall surface of each of the upper member and the lower member is coated with a heat insulating material.