CS233164B1 - Intake manifold, especially for internal combustion engine - Google Patents

Abstract

The invention relates to an intake manifold, especially for internal combustion engines, formed by a casing surrounding bypass walls through which air or a fuel-air mixture flows. The essence of the invention lies in the fact that at least a part of the bypass wall of the intake manifold forms a helical surface. The bypass walls are formed by the inner wall of the intake manifold of non-circular cross-section. The bypass walls can be formed on a deflector arranged inside the intake manifold

Description

(54) Intake manifold, especially for internal combustion engine

BACKGROUND OF THE INVENTION The invention relates to an intake manifold, in particular for internal combustion engines, comprising a casing surrounding bypass passages bypassing air or a fuel-air mixture.

It is an object of the invention that at least a portion of the bypass wall of the suction line forms a helical surface. The bypass walls are formed by the inner wall of the suction pipe of non-circular cross-section. The bypass walls may be formed on a deflector arranged inside the suction line.

233 164 (11) (B1) (51) IntCI. ⁵ F02M 29/04

233 164

BACKGROUND OF THE INVENTION The invention relates to an intake manifold, in particular for an internal combustion engine, comprising a casing surrounding bypass walls bypassing air or an air-fuel mixture.

For a perfect combustion of the fuel in the cylinders of the internal combustion engine, it is necessary to create a turbulent environment inside the cylinders which helps to effectively burn the fuel. It is advantageous to cause turbulence even during the engine intake cycle, thereby effectively mixing the mixture in the engine cylinder, and thus turbulence is also favorably affected during the compression cycle. In modern diesel engines, turbulence is induced by spiral intake ducts that run tangentially to the engine cylinder or by forming an orifice plate on the intake valve. These methods, although favorably affecting combustion, have a common disadvantage. The intake air or fuel-air flow is changed just before entering the engine cylinder near the intake valve. In order to induce the necessary turbulence, it is necessary in these cases to select a shape which adversely affects the flow resistance; thereby reducing the volumetric efficiency of the engine.

The aim of the suction line according to the invention is to achieve a turbulent flow of intake air or somewhere without substantially increasing the flow resistances while

achieved favorable volumetric efficiency of the engine.

233 164

The essence of the suction line according to the invention is that at least part of the bypass wall of the suction line forms a helical surface. The bypass wall may be formed by an inner wall of a suction pipe of non-circular cross section, or it may be formed on a deflector arranged inside the suction pipe.

The advantage of the intake manifold according to the invention is that it is possible to bring the intake air flow into the required turbulent flow without significantly increasing the flow resistances of the intake manifold or achieving greater turbulence in the engine cylinder at the same flow resistance.

An exemplary embodiment of the intake manifold according to the invention is shown schematically in the accompanying drawings, in which Fig. 1 shows a plan view of the intake manifold with partial cross-sectional views thereof; Fig. 2 shows a side view of the intake manifold.

The illustrated intake manifold 1 is intended for a four-stroke spark-ignition internal combustion engine with double intake valves and is formed by a mixing chamber 4 from which two arms extend, each of which is directed to the intake valves of two cylinders. These arms form part of the intake manifold between the mixing chamber and the cylinder head inlet. At the inlet to the mixing chamber 4 an inlet flange is provided for fastening the carburetor, the suction pipe X being fixed to the cylinder head by means of the outlet flange. The cross section of the arms of the intake manifold X is non-circular, the arms being twisted into a helix. The individual inner walls χ of the intake manifold χ and form screw surfaces. The inner walls X thus form bypass walls for the flowing air or mixture.

- 3 233 164

The intake air or mixture stream flows from the carburetor through the mixing chamber 6 to the arms 2 of the intake manifold 6. The flow of the intake air or mixture is brought along the entire length of the arms to rotate about the longitudinal axis by flowing around the screwed inner walls. The sense and speed of rotation of the flowing medium are determined by the helix parameters. The rotating current passes through the intake valves into the cylinder space of the engine, causing the necessary turbulence.

By using only a circular cross section of the suction line, the same effect as in the above-described embodiment can be achieved if the bypass walls are arranged on a separate body - a deflector arranged inside the suction line.

- 4 SCOPE OF THE INVENTION

Claims (3)

233 164 Intake manifold in particular for an internal combustion engine comprising a casing surrounding bypass walls bypassing air or a fuel-air mixture, characterized in that at least a portion of the bypass wall of the intake manifold (1) forms a helical surface. Intake manifold especially for an internal combustion engine according to claim 1, characterized in that the bypass walls are formed by an inner wall (3) of the intake manifold (1) of non-circular cross-section. Intake manifold especially for an internal combustion engine according to claim 1, characterized in that the bypass walls are formed on a deflector arranged inside the intake manifold.