Exhaust manifold for internal combustion engine
The present invention relates to an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders capable of preventing an increase in the fuel consumption and of reducing load application time. The engine satisfies at least one of the following expressions, where D is the diameter of a main tube of the exhaust manifold, d is the diameter of a branch tube, D1 is the diameter of a passage of a connection connecting the branch tube to the main tube, R is the radius in the outer peripheral side of the connection smoothly connecting the branch tube to the main tube of the exhaust manifold, and r is the radius in the inner circumference side. 1.2≦(D/d)2 ≦2.5, 0.8≦(d/de)2≦1.2, 0.7≦(D/D1)2≦1.4, 1.7≦R/r≦2.1.
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The present invention relates to an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders.
BACKGROUND ARTThere are two sorts of turbocharging systems in an exhaust manifold of an internal combustion engine with a supercharger. One is a pulse turbocharging system and another is a constant-pressure turbocharging system. In the former, it is set up so as to make an exhaust pulse large or enhance in an inlet-port section of a turbine, and the supercharger is driven by the enhanced exhaust pulse. According to the former, its acceleration performance is improved, however, its fuel consumption at a rated horsepower point is increased. In the latter, it is set up so as to change the exhaust pulse into static pressure for using a part with high supercharger effectiveness. According to the latter, its fuel consumption in a rated horsepower point is reduced, however, its acceleration performance is inferior as compared with the former. If both are set up so as to make a main tube's passage small, the exhaust pulse will become enhance, therefore the acceleration performance will be improved.
It has been well known that the fuel consumption will be improved when a load application time(build up time) amount is set up for a long time, on the contrary, the fuel consumption will get worse when the load application time amount is set up short.
In the conventional internal combustion engine, the diameter of the main tube is greatly set up provided on the constant pressure system for the purpose of improving the fuel consumption, although the load application time amount became long.
[Patent reference 1] Utility Model Registration No. 2564126
DISCLOSURE OF INVENTION[Problem(s) to be Solved by the Invention]
An object of the present invention is to provide a manifold for an internal combustion engine in which the fuel consumption is improved and the load application time is reduced or shorten.
[Means for Solving the Problem]
In order to achieve the object mentioned above, in accordance with the invention of claim 1, there is provided an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
the diameter D of a main tube of the exhaust manifold and the diameter d of a branch tube of the exhaust manifold satisfy the expression of 1.2≦(D/d)2≦2.5.
In accordance with the invention of claim 2, there is provided an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
the diameter d of a branch tube of the exhaust manifold and the diameter de of an exhaust valve sheet satisfy the expression of 0.8≦(d/de)2≦1.2.
In accordance with the invention of claim 3, there is provided an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
the diameter D of a main tube of the exhaust manifold and the diameter D1 of a passage connecting a branch tube to the main tube satisfy the expression of 0.7≦(D/D1)2≦1.4.
In accordance with the invention of claim 4, there is provided an exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
a branch tube of the exhaust manifold is smoothly connected to a main tube of the exhaust manifold,
the radius R of the outer peripheral side of a connection connecting the branch tube to the main tube and the radius r of the connection satisfy the expression of 1.7≦R/r≦2.1.
[Effect of the Invention]
According to the invention of claim 1, the load application time (build up time) can be reduced without worsening the fuel consumption. According to the invention of claim 2, 3 and 4, the same effectiveness or advantage as invention of claim 1 can be done so.
BRIEF DESCRIPTION OF THE DRAWINGS
[Description of Notations]
- 1 Main Tube
- 2 Branch Tube
- 4 Piston
- 5 Exhaust Valve
- 6 Exhaust Port
- 7 Connection
- 10 cylinder
- 100 Exhaust Manifold
- d Diameter of a branch tube
- de Diameter of an exhaust valve sheet
- D Diameter of a main tube
- D1 Diameter of a connection
- D2 Diameter of a boa
- r Inner circumference radius
- R Outer periphery radius
As shown in
A cross-section configuration of a passage of the branch tube 2 or a connection 7 is not limited in the form of circular. In case the cross-section configuration of the passage of the branch tube 2 or the connection 7 is not formed of circular, it calculates the diameter of the circle of the same area, and applies the value of said calculated diameter as the diameter d of the branch tube 2 and the diameter D1 of the connection 7, respectively.
Basing on the diameter d of the branch tube 2 set up at this time, the diameter D of the main tube 1 is determined using the following expression (1).
1.2≦(D/d)2≦2.5 (1)
As shown in
Therefore, the diameter d of the branch tube 2 and the diameter de of the exhaust valve sheet are set up so that the following expression (2) may be satisfied. 0.8≦(d/de)2≦1.2 (2)
Therefore, the diameter D of the main tube 1 and the diameter D1 of the connection 7 are set up so that the following expression (3) may be satisfied.
0.7≦(D/D1)2≦1.4 (3)
In the case the cross-section configuration of the passage of the connection 7 is not in the form of circular, the diameter of circle of the same area is applied as the diameter D1 of the connection 7.
According to
Therefore, the value of the outer periphery radius R and the inner circumference radius r are set up so that the following expression (4) may be satisfied.
1.7≦R/r≦2.1 (4)
Although it is desirable to satisfy the expressions (1)-(4) altogether as for the exhaust manifold 100, if at least one is satisfied, the load application time can be short set up rather than the conventional exhaust manifold, without worsening fuel consumption.
Claims
1. An exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
- the diameter D of a main tube of the exhaust manifold and
- the diameter d of a branch tube satisfy the expression of 1.2≦(D/d)2≦2.5.
2. An exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
- the diameter d of a branch tube of the exhaust manifold and the diameter de of an exhaust valve sheet satisfy the expression of 0.8≦(d/de)2≦1.2.
3. An exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
- the diameter D of a main tube of the exhaust manifold and the diameter D1 of a passage of a connection connecting a branch tube to the main tube satisfy the expression of 0.7≦(D/D1)2≦1.4.
4. An exhaust manifold for a supercharger-equipped internal combustion engine having multiple cylinders, characterized in that;
- a branch tube is smoothly connected to a main tube of the exhaust manifold via a connection,
- the radius R of the outer peripheral side of the connection, and the radius r of the inner circumference side of the connection satisfy the expression of 1.7≦R/r≦2.1.
Type: Application
Filed: Nov 12, 2004
Publication Date: Apr 12, 2007
Applicant: Yanmar Co., Ltd. (Osaka-shi)
Inventors: Hiroshi Omote (Osaka-shi), Shunji Hamaoka (Osaka-shi), Keiichi Tsujimoto (Osaka-shi)
Application Number: 10/579,493
International Classification: F01N 5/02 (20060101); F01N 7/00 (20060101);