Intake System for an Internal Combustion Engine, in Particular of a Motor Vehicle

Abstract

An intake system for an internal combustion engine has at least one inlet channel through which air can flow and by which the air flowing through the inlet channel is to be conducted into at least one combustion chamber of the internal combustion engine. The inlet channel is, on the bottom side thereof, of flat form at least in one length region, wherein the flat bottom side extends as far as a tumble edge by which a tumbling flow of the air flowing into the combustion chamber can be effected.

Claims

1. An intake system for an internal combustion engine, comprising: at least one inlet duct through which air flows and by which the air which flows through the inlet duct is conducted into at least one combustion chamber of the internal combustion engine, wherein the inlet duct has a flat underside at least in one length region on the underside, and the flat underside extends as far as a tumble edge, by which a tumble-shaped flow of the air which flows into the combustion chamber is effected.

2. The intake system according to claim 1, wherein the inlet duct is of asymmetrical configuration in cross section at least in one length region on an upper side which lies opposite the underside.

3. The intake system according to claim 1, wherein the tumble edge is produced by machining.

4. The intake system according to claim 3, wherein the tumble edge is produced by milling which is rotationally symmetrical with respect to a valve axis of a gas exchange valve.

5. The intake system according to claim 1, wherein the inlet duct is machined on the underside.

6. The intake system according to claim 5, wherein the inlet duct is machined on the underside by way of an end mill, a pear-shaped cutter, a spherical cutter and/or a side milling cutter.

7. The intake system according to claim 5, wherein the inlet duct is machined on the underside as far as a valve seat ring.

8. The intake system according to claim 2, wherein the inlet duct is machined on at least one side which is arranged between the underside and the upper side.

9. The intake system according to claim 5, wherein the inlet duct is widened by way of the machining.

10. The intake system according to claim 1, wherein on an upper side, the inlet duct has at least one clearance portion for spray jets of an injector which is configured for bringing about an intake manifold fuel injection.

11. The intake system according to claim 8, wherein the inlet duct is machined by way of an end mill or side mill cutter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a diagrammatic side view of an intake system according to an embodiment of the invention, having at least one inlet duct, the flat underside of which extends as far as a tumble edge.

[0026] FIG. 2 shows details of a diagrammatic rear view of the intake system.

[0027] FIG. 3 shows details of a further diagrammatic rear view of the intake system.

[0028] FIG. 4 shows details of a diagrammatic side view of the intake system.

[0029] FIG. 5 shows details of a further diagrammatic rear view of the intake system.

[0030] In the figures, identical or functionally identical elements are provided with identical designations.

DETAILED DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 shows a diagrammatic side view of an intake system (denoted overall by 1) for an internal combustion engine (not shown in greater detail in the figures) which is preferably configured as a reciprocating piston engine. The internal combustion engine is, for example, a constituent part of a drive train of a motor vehicle which can be configured as a car, in particular as a passenger car, and can be driven by way of the internal combustion engine. Here, the internal combustion engine has at least one combustion chamber which is configured, in particular, as a cylinder and is formed, for example, by way of an engine housing of the internal combustion engine.

[0032] The engine housing is, for example, a crankcase, in particular a cylinder crankcase. During combustion operation of the internal combustion engine, the cylinder is supplied with air and fuel, in particular liquid fuel, for operating the internal combustion engine. The fuel is injected directly into the cylinder, for example, by way of a direct fuel injection system. As an alternative or in addition, it is conceivable that what is known as an intake manifold injection system is provided. Within the context of the intake manifold injection system, the fuel is not perhaps injected directly into the cylinder, but rather into the intake system 1 at a point which is arranged upstream of the cylinder, and is entrained, for example, by the air which flows through the intake system 1, and is transported into the cylinder. The intake system 1 is arranged in an intake section of the internal combustion engine, through which intake section air can flow, with the result that the air which is to be fed to the cylinder is conducted to and, in particular, into the cylinder by way of the intake system 1.

[0033] To this end, the intake system 1 comprises at least one inlet duct 2 which can be seen particularly clearly in combination with FIG. 2, through which the air to be fed to the cylinder can flow, and which is formed or delimited, for example, by way of a duct element 3 of the intake system 1. In particular, the inlet duct 2 is provided in the abovementioned cylinder head and is formed by way of the cylinder head, with the result that, for example, the duct element 3 is formed by way of the cylinder head or the cylinder head is the duct element 3. The abovementioned point, at which the fuel is injected into the intake system 1 within the context of the intake manifold injection system, is provided, for example, in the inlet duct 2, with the result that the fuel is injected into the inlet duct 2 within the context of the intake manifold injection system.

[0034] It can be seen particularly clearly from FIGS. 2 and 3 that the inlet duct 2 branches into two duct parts 4 and 5 which are also called duct branches, in particular in the flow direction of the air which flows through the inlet duct 2. The duct branches for their part form respective inlet ducts, via which the air can flow into the cylinder. Here, the respective duct part 4 or 5 has an outflow opening 6 which is configured as a through opening and via which the air which flows through the inlet duct 2 can flow out of the duct branches and therefore out of the inlet duct 2 overall.

[0035] In the finally produced state of the internal combustion engine, the respective duct branch is assigned a gas exchange valve which is configured as an inlet valve and can be moved, in particular translationally, between a closed position and at least one open position, in particular relative to the duct element 3. In the closed position, the respective inlet valve closes the respective outflow opening 6, with the result that the air cannot flow via the outflow opening 6 out of the inlet duct 2 into the cylinder. In the open position, however, the respective inlet valve releases the respective outflow opening 6, with the result that air can then flow via the respective outflow opening 6 out of the inlet duct 2 into the cylinder. Here, the gas exchange valve has a valve axis, along which the gas exchange valve can be moved, for example, between the closed position and the open position. In particular, the valve axis is a center axis, the gas exchange valve being, for example, of rotationally symmetrical configuration in relation to the valve axis or center axis.

[0036] Furthermore, the respective outflow opening 6 or the respective duct branch is assigned a valve seat ring 7, by way of which a respective valve seat 8 for the respective inlet valve is formed. In the closed position, the respective inlet valve is seated on the respectively associated valve seat 8, as a result of which the respective outflow opening 6 is closed fluidically. Here, for example, the duct element 3 and the valve seat ring 7 are configured as components which are produced separately from one another and, in particular, are connected to one another, it being possible for said components to preferably be formed from materials which are different than one another.

[0037] It can be seen particularly clearly from FIGS. 1 to 3 that the inlet duct 2 or the duct element 3 is of flat or planar configuration on its underside 9 at least in one length region and here, in particular, in the region of the respective duct branches.

[0038] In order for it then to be possible for particularly efficient and therefore low-fuel consumption and low-emissions operation of the internal combustion engine to be realized, it is provided in the case of the intake system 1 that the flat underside 9 extends as far as a respective tumble edge 10 of the respective duct branch, it being possible for a tumble-shaped flow of the air which flows into the cylinder to be brought about by means of the tumble edge 10. Moreover, the inlet duct 2 is drawn down to a great extent at the respective valve seat ring 7 with retention of the distinct tumble edge 10. Moreover, it is provided that (as can be seen, in particular, from FIG. 3) the inlet duct is of asymmetrical configuration in cross section on its upper side 11 which lies opposite the underside 9, in particular in the region of the respective duct branch. In other words, the respective upper side 11 of the individual duct branches is asymmetrical in cross section. By way of said configuration of the inlet duct 2, a particularly high charge movement can be realized, with the result that particularly advantageous mixture preparation and particularly rapid combustion can be realized. This results in a particularly high thermodynamic degree of efficiency, with the result that the fuel consumption of the internal combustion engine can be kept particularly low.

[0039] It has been shown to be particularly advantageous, furthermore, if the respective tumble edge 10 is produced by milling which is rotationally symmetrical with respect to a valve axis of a gas exchange valve. Here, for example, the inlet duct 2 is machined at least in a part region by use of a pear-shaped and/or spherical cutter, the respective tumble edge 10, in particular, being produced by use of a pear-shaped and/or spherical cutter of this type, in particular within the context of said milling. As can be seen particularly clearly from FIGS. 4 and 5, the inlet duct 2 has, moreover, a further, additional machined portion which is produced, for example, by an end mill or side milling cutter at least in respective part regions 12. By way of said further, additional machined portion, the inlet duct 2 is widened on its underside 9 and preferably on at least one side 13 which is arranged between the underside 9 and the upper side 11. In other words, the further, additional machined portion is provided at least laterally, with the result that the inlet duct 2 is also widened laterally by way of said further, additional machined portion. In particular, the inlet duct 2 is machined or widened by way of the additional, further machined portion at most as far as the valve seat ring 7. In other words, the additional further machined portion is preferably conducted as far to the outside as possible and in the process at most as far as the valve seat ring 7.

[0040] In order to realize the intake manifold injection system, at least one fastener (cannot be seen in the figures) is provided, in particular per duct branch, by means of which fastener an injector for bringing about the intake manifold injection can be fastened to the intake system 1 or to the duct element 3. The respective injector is also called an intake manifold injector, the respective injector providing, that is to say ejecting or spraying, at least one or more spray jets, in particular within the context of the intake manifold injection. The respective spray jet is formed by way of the abovementioned fuel for operating the internal combustion engine and/or by way of another (in particular, liquid) medium, and is injected into the inlet duct 2. Here, the spray jet widens or the spray jets widen along an injection direction, in particular starting from the injector. The fastener comprises, for example, a receptacle, in which the respective injector can be received at least partially. The receptacle is configured, for example, as a through opening, and has a length region, through which the spray jets can be sprayed. Here, a clearance portion 14 is preferably provided for the spray jets, with the result that excessive wetting of walls of the duct element 3 with the fuel can be avoided. Moreover, the fasteners are arranged on the upper side 11, with the result that the injectors can be mounted particularly simply. The fasteners or the clearance portions 14 represent an allowance for the intake manifold injection system, with the result that the intake manifold injection system can optionally be used or else can be dispensed with.

[0041] Furthermore, a guide 15 which is configured, for example, as a through opening is provided per duct branch, by means of which guide 15 the respective gas exchange valve is guided during its movements between the closed position and the open position.

[0042] It has been found that the inlet duct 2 generates a particularly high charge movement of the air. This leads to advantageous mixture preparation and to high turbulent kinetic energy of the air which flows into the cylinder. This results in a particularly high combustion rate, with the result that particularly efficient operation of the internal combustion engine can be produced.

LIST OF DESIGNATIONS

[0043] 1 Intake system [0044] 2 Inlet duct [0045] 3 Duct element [0046] 4 Duct part [0047] 5 Duct part [0048] 6 Outflow opening [0049] 7 Valve seat ring [0050] 8 Valve seat [0051] 9 Underside [0052] 10 Tumble edge [0053] 11 Upper side [0054] 12 Part region [0055] 13 Side [0056] 14 Clearance portion [0057] 15 Guide

[0058] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.