JPH0130580Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is designed to improve the shape of the exhaust manifold of an internal combustion engine, especially for internal combustion engines with turbocharging, which utilize exhaust gas energy as dynamic pressure to perform supercharging. Regarding the shape of the exhaust manifold.

[Conventional technology]

In an internal combustion engine with a turbocharger, each branch pipe of the exhaust manifold leading to the combustion chamber of each cylinder is arranged independently up to just before the turbocharger in order to effectively perform supercharging by using the exhaust gas energy as dynamic pressure. There are things to do. However, in a cast iron exhaust manifold, the partition wall that partitions each branch pipe is exposed to high temperatures at the gathering part where each branch pipe gathers, and the casting crystal grains of this partition wall grow coarse and grow, causing deformation of the partition wall. There is a risk that this may occur. Furthermore, the growth of the partition wall adds force to the outer wall of the exhaust manifold, which in extreme cases may cause cracks to occur in the outer wall of the manifold.

In order to withstand the temperature and pressure of such exhaust gas, various improvements have been made to the exhaust manifold itself, and various proposals have been made. For example, the inner layer and intermediate layer of the exhaust manifold are provided with slidable fitting parts to absorb thermal expansion and prevent damage to the welded parts (Japanese Patent Laid-Open No. 57-52616), or A known example is one in which a ceramic heat insulating material is co-cast on the inner surface of the exhaust manifold when it is cast (Utility Model Application No. 1983-47712).

[Problem that the invention attempts to solve]

The present invention creates a reliable exhaust manifold suitable for turbocharged internal combustion engines by adding innovation to the shape of the exhaust manifold, especially the shape of the partition wall at the gathering part, so that it can sufficiently withstand the temperature of exhaust gas with a simple structure. It's about getting.

[Means for solving problems]

In order to solve these problems, the present invention includes a partition wall that partitions the plurality of branch pipes into at least two groups at the gathering part where the plurality of branch pipes of the exhaust manifold integrally formed of cast iron gather. An exhaust manifold for an internal combustion engine is proposed, characterized in that the partition wall is formed in an arcuate curved shape when viewed from a cross section perpendicular to the axis of the exhaust passage in the gathering portion.

〔Example〕

First, with reference to FIGS. 4 and 5, the shape of an exhaust manifold of a turbocharged internal combustion engine, which has been generally known in the past, will be explained.

In FIGS. 4 and 5, an exhaust manifold 10 integrally formed of cast iron is installed in each cylinder combustion chamber (not shown) of an internal combustion engine in order to prevent interference caused by exhaust gas pulsation and to effectively utilize dynamic pressure. Branch pipes 1, 2, 3, and 4 communicating with each other are independently arranged up to just before a turbocharger turbine (not shown), that is, just before an exhaust manifold outlet 16. Therefore, the collecting portion 12 is located near the outlet opening 16 of the exhaust manifold. The partition wall 14 extending to the outlet opening 16 includes #1 and #4 branch pipes 1, 4 and #2 and #3 branch pipes 2, 3.
It is in charge of the Conventionally, as shown in FIG. 4, this partition wall 14 has a straight shape when viewed from a cross section perpendicular to the axis of the exhaust passage in the collecting portion 12, and both ends thereof extend to the exhaust manifold outer wall 18, and the partition wall 14 has a straight shape when viewed from a cross section perpendicular to the axis of the exhaust passage in the collecting portion 12, and both ends thereof extend to the exhaust manifold outer wall 18, and the partition wall 14 has a straight shape when viewed from a cross section perpendicular to the axis of the exhaust passage in the gathering portion 12. 16 is divided into two parts, and as mentioned above, repeated use at high temperatures will cause the casting crystal grains in the partition wall 14 to become coarser, resulting in the crystal grains becoming coarser in the direction shown by the arrows in FIGS. 4 and 5. There was a risk that the particles would grow and even affect the exhaust manifold outer wall 18, causing deformation as shown by the two-dot chain line 14' in FIG.

1 to 3 show an embodiment of the exhaust manifold of the present invention. The exhaust manifold 10 is integrally formed of cast iron, and each branch pipe 1, 2, 3, 4 communicating with each cylinder combustion chamber (not shown) is located just before the turbocharger turbine (not shown), that is, the exhaust manifold outlet. 16, and the converging portions 12 are located near the outlet opening 16, as in the prior art.

The bulkhead 20 extends to the outlet opening 16.
It is the same as the conventional partition wall 14 in that it partitions the #1 and #4 branch pipes 1 and 4 from the #2 and #3 branch pipes, but in the present invention, the partition wall 20 is , the exhaust passage in the gathering part 12 is formed in an arch-like or inverted F-shaped curved shape when viewed from a cross section perpendicular to the axis, and both ends thereof are connected to the exhaust manifold outer wall 1.
8 and divides the exhaust manifold outlet opening 16 into two. Then, the relationship between #1 branch pipe 1 and #4 branch pipe 4, and the relationship between #2 branch pipe 2 and #3
As seen from FIG. 1, the relationship between the branch pipes 3 is
It has a slightly inverted F-shape extending along the arcuate partition wall 20 with each of them at the center. Since the partition wall 20 is curved in an arcuate shape in this way, even if the casting crystal grains in the partition wall 14 become coarse and deformed due to repeated use at high temperatures, the crystal grains in the partition wall 14 may become coarse and deformed, as indicated by the two-dot chain line 20' in FIG. As such, the partition wall 14 itself is easily deformed in the direction of reducing the arcuate curvature, and therefore the exhaust manifold outer wall 18 is not affected much. Therefore, there is no risk that the exhaust manifold outer wall 18 itself will be deformed.

[Effect of idea]

As described above, according to the present invention, the high temperature of the exhaust gas is only affected by the partition wall in the gathering part of the exhaust manifold, and does not affect the outer wall of the exhaust manifold, so deformation or cracking of the outer wall may occur. There is no danger of it happening. Therefore, the present invention improves the reliability of an exhaust manifold that utilizes dynamic pressure supercharging of exhaust gas, such as in a turbocharged internal combustion engine.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the exhaust manifold of the present invention, Fig. 2 is a sectional view taken along the line - of Fig. 1, Fig. 3 is a sectional view taken along the line - of Fig. 1, and Fig. 4 is a sectional view of the conventional exhaust manifold. The plan view, FIG. 5, is a sectional view taken along the line - in FIG. 4. DESCRIPTION OF SYMBOLS 1, 2, 3, 4... Branch pipe, 10... Exhaust manifold, 12... Collection part, 16... Outlet opening, 20... Partition wall.

Claims (1)

[Scope of utility model registration request] A partition wall that divides the plurality of branch pipes into at least two groups is integrally provided at a collecting part where a plurality of branch pipes of an exhaust manifold integrally formed of cast iron are collected, and the partition wall is provided at the collecting part in which the plurality of branch pipes are divided into at least two groups. An exhaust manifold for an internal combustion engine, characterized in that the exhaust manifold has an arcuate curved shape when viewed from a cross section perpendicular to the axis of the exhaust passage.