AT500517A1 - INTERNAL COMBUSTION ENGINE WITH AN INTAKE PIPE ASSEMBLY - Google Patents

Description

< Λ • ♦ • • • • ♦ ♦ • • • • - ι ';

55171

The invention relates to an internal combustion engine having an inlet pipe arrangement for at least two cylinders.

From WO 02/057617 Al a device for reducing the intake air noise is known. In this case, a tuning tube is provided in addition to an inlet tube, wherein the length of the inlet tube and the tuning tube are dimensioned so that half a wavelength wave of the engine noise is extinguished. With this device, the engine noise can be damped.

The object of the invention is to selectively modify the intake pipe noise in order to achieve noise shaping of the engine noise.

According to the invention, this is achieved in that the inlet pipes have different lengths for at least two cylinders.

It is preferably provided that at least a second inlet pipe is longer than the first inlet pipe by at least 5%, preferably by at least 10%.

Additionally or alternatively, it can be provided that at least a third inlet pipe is at least 5%, preferably at least 10%, shorter than the first inlet pipe.

By these measures, it is possible other orders in the intake noise than those dominated by cylinder number and operation (2- / 4-stroke) (second order in 4-cylinder 4-stroke engine, third order in 6-cylinder 4 Clock motor, etc.). For example, in the intake noise, it is possible to raise the 1st, 5th and 2nd engine orders to the 2nd order dominant in the 4-cylinder engine. Although it comes to minimal differences in delivery, which, however, only slightly affect the performance of the internal combustion engine.

The invention will be explained in more detail below with reference to FIG.

The figure shows schematically an internal combustion engine 10 with a plurality of cylinders 1, 2, 3, 4, with an inlet pipe assembly 20 and an outlet pipe assembly 30. The inlet pipe assembly 20 has per cylinder at least one of a common inlet header 22 outgoing inlet pipe 5, 6, 7, 8 , To the intake manifold 22, a common intake passage 24 leads.

In order to selectively modify the noise of the internal combustion engine 10, at least one second intake pipe is made longer by at least 10% than at least one first intake pipe 6, 7, 8. By selectively changing the intake pipe length of at least one cylinder, e.g. of the cylinder 1, the l, 5 th and 2,5 th engine orders in the intake noise are raised relative to the second order dominant in the 4-cylinder engine. Any differences in delivery grade compared to the other three cylinders 2, 3, 4 are deliberately accepted.

It is particularly advantageous if, in the case of at least two cylinders 1, 4, an opposite change in the intake pipe lengths, e.g. Extension of the second inlet pipe 5 of the first cylinder 1 and shortening of the third intake pipe 8 of the cylinder 4 with respect to the first intake pipes 6, 7 of the cylinder 2, 3 is performed. Thereby, the desired orders can be increased and at the same time the delivery degree deviations to the remaining cylinders 2, 3 can be minimized. Calculated can be achieved at half change the intake manifold length with this design similar rule increases as with full change in a single cylinder, with a significant improvement in air distribution is achieved. Since the engine control is faced with fewer cylinder deviations from the mean, the calibration effort is reduced.

Claims (3)

1. internal combustion engine (10) with an inlet pipe arrangement (20) for at least two cylinders (1, 2, 3, 4), characterized in that the inlet pipes (5, 6, 7, 8) for at least two Cylinders (1, 2, 3, 4) have different lengths. 2. internal combustion engine (10) according to claim 1, wherein at least a first inlet pipe (6, 7) to a cylinder (2, 3) and at least a second inlet pipe (5) leads to another cylinder (1), characterized in that at least a second inlet pipe (5) is at least 5%, preferably at least 10%, longer than the first inlet pipe (6, 7). 3. internal combustion engine (10) according to claim 1 or 2, wherein at least a first inlet pipe (6, 7) to a cylinder (2, 3) and at least a third inlet pipe (8) leads to another cylinder (4), characterized in that at least a third inlet pipe (8) is shorter by at least 5%, preferably by at least 10%, than the first inlet pipe (6, 7). 2004 12 02 Fu / Sc A-1150 Vienna, Mariahilfer Gürtel 39/1; Tel .: (+43 1) 8¾ 89 33-5 fax: (+43 1) S92 83 333 ** m * il: petentehabeiuk at x Patent Attorney Dipl.-Ing. Mag. Michael Babelul ·