Intake manifold

Abstract

Intake manifold (30), comprising: a housing structure (31) defining a collection space (33); an air inlet duct (40) coupled to the housing structure (31), the air inlet duct (40) being arranged to introduce charge air into the plenum (33) in a first direction; a secondary gas inlet (60) arranged to discharge secondary gas into the housing structure (31) in a second direction, substantially opposite to the first direction, wherein the air inlet channel (40) comprises an inlet valve (50), and wherein the second direction is oriented towards the inlet valve (50); and wherein the inlet valve (50) is a butterfly valve comprising a valve disc (54), and wherein the secondary gas inlet (60) is arranged to discharge secondary gas towards a center of the valve disc (54), and wherein the secondary gas inlet (60) is constructed as an inlet tube (61) having an outlet end (65) received within the housing structure (31), and wherein a distance between the outlet end (65) and the air inlet valve is less than 2 times the diameter of the valve disc (54).

Description

TECHNICAL FIELD

[0001] This disclosure relates to an intake manifold for internal combustion engines and, more specifically, to a device for introducing secondary gases into the intake manifold.

[0002] The invention further relates to an internal combustion engine and a vehicle comprising the intake manifold. STATE OF THE ART

[0003] In internal combustion engines, the intake manifold is a part that supplies air or a fuel / air mixture to the cylinder head of a corresponding cylinder block.

[0004] The engine may be a multi-cylinder engine and the manifold may be arranged to supply air or a fuel / air mixture to a plurality of cylinders.

[0005] It is well known that supplying a uniform mixture of fuel and charge air to each respective cylinder is crucial for fuel efficiency, environmental impact and improvement of an internal combustion engine.

[0006] If the fuel and charge air from the intake manifold are not distributed evenly, this can result in each separate cylinder having different fuel / air mixture ratios.

[0007] As a result, some cylinders may receive a “fuel-rich” mixture, whereas other cylinder heads may be supplied with a “fuel-lean” mixture.

[0008] This discrepancy in the mixture ratios can lead to increased fuel consumption, higher emissions and engine instability.

[0009] Secondary gases can be mixed with the charge air to reduce (among other things) evaporative emissions.

[0010] Secondary gases can be any purified gas from a fuel tank vent control system, a vent gas from a crankcase ventilation system, exhaust residue from an exhaust gas recirculation system, or other known gases introduced into the intake manifold.

[0011] Conventional manifolds include a plenum chamber for mixing charge air, primary and / or secondary gases.

[0012] The gas mixture created in the collection chamber is then distributed to a number of cylinders via individual channels that connect each of the cylinders to the collection chamber.

[0013] In order to achieve the required degree of mixing of secondary gases and charge air, it is known to provide conventional intake manifolds with a large collection space.

[0014] This design ensures that charge air introduced into the plenum via a gas inlet at a first end of the manifold remains within the plenum long enough for the secondary gases to be sufficiently mixed with the charge air before the mixture is distributed into individual channels connecting the plenum to corresponding cylinder heads.

[0015] In recent years, however, tight space conditions within the engine compartment of, for example, passenger cars have required intake manifolds to be significantly reduced in size, thus preventing large collection spaces and resulting in a loss of performance.

[0016] From US 2014 / 0165948 A1 an intake manifold is known which is capable of releasing oil or water into a liquid reservoir in a stable manner.

[0017] JP 2000054915A relates to an EGR device comprising a tip portion of an EGR pipe connecting an exhaust passage of an engine to an intake passage and inserted into and protruding from the intake passage. An opening portion at the tip of the EGR pipe is arranged to face the intake air upstream.

[0018] In view of the foregoing, this invention aims to remedy the disadvantages associated with the prior art.

[0019] In particular, it is the object of the present invention to provide an intake manifold that facilitates improved mixing of secondary gases and charge air before entering the channels, while at the same time having a compact design that takes into account current space constraints. SUMMARY OF THE INVENTION

[0020] The invention relates to an intake manifold according to claim 1, an internal combustion engine according to claim 19 and a vehicle according to claim 22.

[0021] According to one aspect of the present invention, an intake manifold is provided comprising a housing structure including a plenum and an air inlet duct coupled to the housing structure, the air inlet duct being arranged to introduce charge air into the plenum in a first direction.

[0022] The intake manifold includes a secondary gas inlet arranged to discharge secondary gas into the housing structure in a second direction toward the air inlet duct substantially opposite to the first direction.

[0023] According to the present invention, secondary gases, such as purge gas, recirculated exhaust gas or crankcase ventilation gases, are injected into the plenum substantially against the onset flow of charge air.

[0024] This special arrangement results in a high degree of mixing of charge air and the secondary gas before the air mixture is distributed to the cylinders.

[0025] Due to the improved mixing properties, the size of the collection chamber can be significantly reduced while maintaining the same degree of mixing as with previous state-of-the-art solutions.

[0026] In other words, this invention provides an intake manifold that meets engine functionality requirements while minimizing intake manifold volume, weight, and cost.

[0027] In addition, improved vehicle transmission behavior can be achieved through lower throttled volumes of charge air.

[0028] The secondary gas inlet can be constructed in different ways.

[0029] As described in more detail below, one embodiment includes a secondary gas inlet tube extending through an outer wall of the housing structure into the interior air volume to deliver secondary gas toward the air inlet duct.

[0030] However, it is also possible to construct the secondary gas inlet as a bore in the outer wall of the housing structure, wherein the bore is in this case arranged to end at a position of the housing structure that releases secondary gas into the internal air volume towards the air inlet channel.

[0031] According to another embodiment, the air inlet duct is arranged to introduce charge air into the plenum in a first direction substantially opposite to the second direction.

[0032] While it is entirely within the scope of this invention to introduce charge air into the plenum in a first direction that is at an angle of up to 30° relative to the second direction, it has been found that mixing levels are maximized when charge air is introduced in a direction directly opposite to the secondary gas.

[0033] According to the invention, the air intake duct comprises an intake valve, with the second direction being oriented toward the intake valve. It has been found that vortices forming downstream of the valve assist in mixing the charge air with the secondary gas if the secondary gas is injected toward the intake valve, where the vortices are generated.

[0034] According to the invention, the intake valve is designed as a butterfly valve comprising a valve disc, wherein the secondary gas inlet is arranged to discharge secondary gas towards a center of the valve disc and against the incoming flow of intake air.

[0035] The butterfly valve may include a valve stem extending through the center of the valve disc. The secondary gas may be discharged toward the valve stem of the butterfly valve, which has been found to assist in recirculating the secondary gas flow toward the vortexes created by the butterfly valve on the sidewalls of the air intake duct.

[0036] It may be advantageous to design the butterfly valve so that the valve stem extends beyond a valve disc surface that faces the internal air volume of the body structure.

[0037] In other words, the valve stem projects at least partially into an internal volume within the housing structure and acts as an airflow distributor that redirects the secondary gas flow from the center of the butterfly valve toward its outer periphery, i.e., toward the side walls of the housing structure.

[0038] In yet another embodiment, the housing structure defines a mixing chamber extending between the air inlet valve and the plenum.

[0039] The mixing chamber is a specially designed part for an air volume within the housing structure that ensures sufficient mixing of the charge air with the primary and / or secondary fuel gases.

[0040] The mixing chamber is shaped so that the mixing of the charge air with the primary / secondary gases is essentially completed before the air / gas mixture enters the plenum.

[0041] In addition, the mixing chamber can have a significantly smaller cross-sectional area of ​​fluid flow than the collection space.

[0042] The secondary gas inlet may be constructed as an inlet pipe and extends at least partially into the plenum and / or the mixing chamber.

[0043] As stated hereinabove, the secondary gas inlet may also be constructed as a bore disposed in the side walls of the housing structure.

[0044] However, designing the secondary gas inlet as an inlet tube provides better control over the secondary gas flow within the housing structure, which helps to direct the secondary gas flow toward the inlet air duct, i.e., the second direction.

[0045] The secondary gas inlet pipe may extend straight within the housing structure.

[0046] Alternatively, the inlet tube may be curved within the housing structure as long as the secondary gas is ultimately discharged in the second direction.

[0047] According to another embodiment, an outlet end of the second gas inlet tube is received in the mixing chamber.

[0048] It has been found that moving the outlet end of the intake pipe closer to the intake valve by placing the outlet end within the mixing chamber increases the mixing effect between the charge air and the secondary gases.

[0049] However, it is equally possible to arrange the outlet end of the inlet pipe within the plenum so that the secondary gases are discharged towards the mixing chamber / air inlet duct.

[0050] To ensure sufficient mixing levels in the intake manifold of the present invention, the length of the mixing chamber may be more than 0.5 times the diameter of the valve disc, preferably more than 0.75 times the diameter of the valve disc. It should be understood that the length of the mixing chamber refers to the charge air flow path between the air intake valve and the plenum.

[0051] Optionally, if the secondary gas inlet is an inlet tube with an outlet end housed in the housing structure, the distance between the outlet end and a central axis of the valve stem may be less than twice the diameter of the valve disc, preferably less than 1.5 times the diameter of the valve disc. Positioning the outlet end of the secondary gas inlet tube near the inlet valve has been found to be advantageous.

[0052] This is because vortices form at a certain distance from the valve disc, which depends on the diameter of the valve disc and therefore the diameter of the air intake duct.

[0053] It has been found that the best mixing results are achieved if secondary gases are introduced upstream of the vortexes, i.e. closer to the valve disc than the vortexes themselves.

[0054] As explained above, the secondary gas inlet tube can be straight or curved within the internal volume of the housing structure.

[0055] Accordingly, in one embodiment, a secondary gas inlet tube is provided comprising an injector portion proximate the outlet end, wherein at least the injector portion of the secondary gas inlet tube extends along an injection axis aligned with the second direction.

[0056] In simple terms, the last part of the inlet pipe immediately before the outlet end extends in the second direction to discharge secondary gas along the injection axis, that is, along the second direction.

[0057] The injection axis may intersect a central axis of the air intake duct at an angle between -25° and 25°, preferably between -10° and 10°.

[0058] If a butterfly valve is mounted at the outlet end of the intake air duct, this corresponds to the intersection of a central axis of the intake valve at the angles through the injection axis.

[0059] Furthermore, the radial distance between the center axis of the air intake duct and the injection axis at the outlet end of the secondary gas inlet pipe can be less than 0.25 times the diameter of the valve disc. The aforementioned dimensions ensure that the secondary gas flow within the mixing chamber is most effectively directed toward a central area of ​​the intake valve.

[0060] In one embodiment, the injection axis may be aligned coaxially with the center axis of the air inlet duct so that the secondary gas flow is directed exactly toward the center of the air inlet duct.

[0061] In another embodiment, the secondary gas inlet is a purge gas inlet connected to a tank venting control system.

[0062] Alternatively, the secondary gas inlet may be a recirculation inlet connected to an exhaust gas recirculation system.

[0063] In either case, the secondary gas inlet may be a passive gas inlet, meaning that secondary gas may be drawn into the internal air volume by a vacuum created during operation of the respective combustion chambers within the intake manifold.

[0064] However, it is of course also possible to actively inject secondary gases into the intake manifold, i.e. to provide pressurized secondary gas.

[0065] In another embodiment, the housing structure comprises a second secondary gas inlet arranged to discharge gas into the internal air volume in a third direction substantially perpendicular to the second direction.

[0066] Alternatively, the secondary gas inlet may be arranged to discharge gas into the internal air volume in the second direction; in this case, the secondary gas inlet may be constructed as a second gas inlet pipe arranged substantially parallel to the inlet pipe of the first secondary gas inlet.

[0067] The secondary gas inlet may be a vent inlet connected to a crankcase ventilation system.

[0068] The intake manifold may include a plurality of channels for fluidly connecting a mixing chamber of the air volume to intake ports of the corresponding cylinder heads.

[0069] As explained above, the ports may be constructed as individual tubes extending from the end of the mixing chamber to a plurality of individual combustion chambers connected to the ports via intake valves of their respective cylinder heads.

[0070] According to another aspect of this invention, there is provided an internal combustion engine comprising an intake manifold as described above herein.

[0071] The internal combustion engine can be a direct injection engine, meaning that the fuel mixture can be injected directly into the combustion chamber rather than into the mixing chamber of the intake manifold.

[0072] The combustion engine can be a gasoline engine (petrol engine); however, it is equally possible to use the described intake manifold in diesel or natural gas engines.

[0073] According to another aspect of this invention, a vehicle is provided including an internal combustion engine as described hereinabove.

[0074] According to another embodiment, an intake manifold is provided for supplying charge air from an air cleaner to an internal combustion engine, the manifold comprising a housing structure defining an air inlet duct arranged to direct charge air from an inlet end to an outlet end to supply the charge air to the engine, the direction of charge air flow through the inlet duct defining a first direction, the manifold further comprising a secondary gas inlet arranged to discharge a secondary gas into the air inlet duct, the secondary gas inlet being arranged to direct the secondary gas into the inlet duct in a second direction substantially opposite to the first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] One or more embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a vehicle according to an embodiment of the present invention; Fig. 2 is a schematic perspective view of an intake manifold according to an embodiment of the present invention; Fig. 3 is a schematic front view of the intake manifold embodiment of Fig. 2; Fig. 4 is a schematic side view of an intake manifold embodiment of Fig. 2; Fig. 5 is a schematic side view of an intake manifold according to another embodiment of the present invention. DETAILED DESCRIPTION

[0076] Fig. 1 shows a vehicle 1 comprising an internal combustion engine 2 with an intake manifold 3 according to the present invention.

[0077] The engine 2 and the intake manifold 3 are arranged in the engine compartment of the vehicle, which is located either at the front or the rear of the vehicle.

[0078] As will be described in more detail below, the intake manifold 3 is connected to an air inlet duct 4 which supplies the intake manifold with fresh air from the ambient air.

[0079] One or more secondary gas inlets may be arranged on the intake manifold 3 to mix secondary gases with the fresh air provided by the air intake duct 4 before the mixture is introduced into the combustion chambers of the internal combustion engine 2 via ducts 5a, 5b and 5c.

[0080] An embodiment of the intake manifold according to the present invention is shown in the schematic views of Fig. 2 to 4.

[0081] The intake manifold 30 generally includes a housing structure 31 that defines a plenum 33.

[0082] The plenum 33 is connected to individual cylinders of an engine (not shown) via a plurality of channels 35a, 35b, 35c and 35d.

[0083] In the embodiment of the Fig. 2 to 4, an air inlet duct 40 is connected to a lower end of the housing structure 31, although it is understood that the invention is not limited to the position of the air inlet duct 40 with respect to the housing structure 31.

[0084] The air inlet duct 40 is coupled to the air housing structure at an outlet end 41 and has a central axis A ( Fig. 4) extending in a longitudinal direction of the air inlet duct 40.

[0085] An inlet valve 50 is arranged at the outlet end 41 of the air inlet duct 40.

[0086] The air inlet duct valve 50 of the Fig. The embodiment shown in Figures 2 to 4 is designed as a butterfly valve.

[0087] The butterfly valve has a valve stem 52 and a valve disc 54.

[0088] In this embodiment, the valve stem 52 is located in the center of the valve disc 54 and protrudes from both surfaces of the valve disc. Specifically, the valve stem 52 protrudes from an upper surface 56 and a lower surface 57 of the valve disc 54.

[0089] In other words, a portion of the valve stem 52 in its closed state extends into a mixing chamber 34 of the housing structure 32, whereas an opposite, second part of the valve stem extends into the air inlet channel 40.

[0090] The mixing chamber 34 extends between the central axis of the air inlet valve 50 and the collection chamber 33, as Fig. 4 can be removed (given as the length L).

[0091] The mixing chamber 34 of the embodiment in Fig. 2 to 4 is a generally funnel-shaped extension of the air inlet duct 40.

[0092] The mixing chamber 34 includes a first end 35 located downstream of the air inlet valve 50, having a first diameter.

[0093] An opposite, second end 36 of the mixing chamber 34 is connected to the collection space 33 and has a second diameter that is larger than the first diameter.

[0094] A first end portion of the mixing chamber 34, directly downstream of the first end 35, is constructed as a rod portion having a substantially constant diameter.

[0095] An opposite, second end portion of the mixing chamber 34, directly upstream of the second end 36, is constructed as a conical portion with a continuously increasing diameter, which eventually opens outwardly to the collection space 33, downstream of the second end 36.

[0096] A first secondary gas inlet 60 is provided and configured to discharge secondary gases, such as exhaust gas recirculation gases and purge gases, into the housing structure 31 and in particular into the mixing chamber 34.

[0097] The secondary gas inlet 60 of the embodiments in Fig. 2 to 4 is constructed as a secondary gas inlet pipe 61.

[0098] The inlet pipe 61 is inserted into the mixing chamber 34 through an outer wall of the housing structure 31 and adapted to direct secondary gas flow toward the air inlet channel 40 in a second direction 11.

[0099] In particular, the air inlet pipe 61 of the Fig. 2 to 4 are arranged pointing downwards into the mixing chamber 34 so that secondary gases are discharged against the inlet air flow provided by the inlet air duct 40.

[0100] The intake / charge air flow of this embodiment is directed in a first direction 12 which is opposite to the second direction 11.

[0101] The charge air flow, which moves substantially in the first direction 12, flows through the inlet valve 50 along the side walls of the air inlet duct 40 and the mixing chamber 34.

[0102] Charge air moving in the first direction 12 forms vortices within the mixing chamber 34.

[0103] As secondary gases are introduced into the mixing chamber 34 in the second direction 11, the secondary gas flow is reflected by the inlet valve 50 and mixes quickly and effectively with the swirls of the charge air.

[0104] In order to introduce the secondary gases in the second direction 11, the inlet pipe 61 comprises an injector section 63 near an outlet end 65 of the inlet pipe 61.

[0105] The injector section runs along an injection axis B which is aligned in the second direction 11.

[0106] In the embodiment of the Fig. 2 to 4, the inlet pipe 61 is curved outside the housing structure 31, and it is only the straight injector section 63 that extends into the mixing chamber 34.

[0107] It should be understood, however, that in other embodiments, parts of the inlet tube accommodated in the housing structure could have a curved shape; the last part of the inlet tube, ie the injector section immediately upstream of the outlet end, is always oriented in the second direction 11.

[0108] A distance between the outlet end 65 of the inlet pipe 61 and the outlet end 41 of the air inlet duct 40 is adapted to be less than 2 times the diameter of the valve disc 54, preferably less than 1.5 times the diameter of the valve disc 54.

[0109] The mixing chamber 34 has a length L that is more than 0.5 times the diameter of the valve disc, preferably more than 0.75 times the diameter of the valve disc. This length defines the volume of the mixing chamber 34 and therefore the degree of mixing of the charge air and the secondary gases before the mixture enters the plenum 33.

[0110] By introducing the secondary gases in the second direction 11 towards the inlet air duct 40, the length L of the mixing chamber 34 and thus the distance I can be considerably reduced without impairing the degree of mixing.

[0111] The Fig. 2 to 4 further show a second secondary gas inlet 70 constructed as a gas inlet pipe 71.

[0112] The second secondary gas inlet pipe 71 is arranged to discharge secondary gases into the plenum 33 in a third direction which is substantially perpendicular to the second direction 11.

[0113] In an alternative embodiment, the second secondary gas inlet 70 could be arranged in parallel with the first secondary gas inlet 60 to discharge secondary gases in the second direction similar to the first inlet tube 61.

[0114] The second secondary gas inlet 70 is designed as a vent inlet connected to a crankcase ventilation system.

[0115] Fig. 5 shows another embodiment of the intake manifold according to the invention, in which the secondary gas inlet 81 is not aligned coaxially with the central axis A of the air inlet duct 40.

[0116] Rather, the injector section 83 of the second, in Fig.4, extend along an injection axis C which intersects the central axis A of the intake air duct 40 at an angle α between -25° and 25°, preferably between -10° and 10°.

[0117] This may be the case if the outlet end 85 of the secondary gas inlet pipe 81 is offset radially from the central axis A of the air inlet duct 40.

[0118] It has been found that the outlet end 85 of the inlet tube 81 should not be spaced radially from the central axis A of the air inlet duct 40 by more than 0.25 times the diameter of the valve disc 54 in order to achieve the desired mixing results.

[0119] It should be understood that if the injection axis C and therefore the second direction 11 is at an angle α with respect to the central axis A, the first direction 12 is still substantially opposite to the second direction 11 according to the present invention.

[0120] The secondary gas inlets 60, 70, 80 of the present invention may be constructed as passive gas inlets, but it is also possible to implement active gas inlets that provide pressurized secondary gas.

[0121] While the above examples have been described with reference to a four-cylinder gasoline engine, it should be understood that this application is not limited to any number of cylinders or any fuel type.

Claims

[1] Intake manifold (30), comprising: a housing structure (31) defining a collection space (33); an air inlet duct (40) coupled to the housing structure (31), the air inlet duct (40) being arranged to introduce charge air into the plenum (33) in a first direction; a secondary gas inlet (60) arranged to discharge secondary gas into the housing structure (31) in a second direction, substantially opposite to the first direction, wherein the air inlet channel (40) comprises an inlet valve (50), and wherein the second direction is oriented towards the inlet valve (50); and wherein the inlet valve (50) is a butterfly valve comprising a valve disc (54), and wherein the secondary gas inlet (60) is arranged to discharge secondary gas towards a center of the valve disc (54), and wherein the secondary gas inlet (60) is constructed as an inlet tube (61) having an outlet end (65) received within the housing structure (31), and wherein a distance between the outlet end (65) and the air inlet valve is less than 2 times the diameter of the valve disc (54). [2] Intake manifold (30) according to claim 1, wherein the housing structure (31) defines a mixing chamber (34) extending between the intake valve (50) and the plenum (33). [3] Intake manifold (30) according to claim 2, wherein the secondary gas inlet (60) is constructed as an inlet pipe (61), the inlet pipe (61) comprising an outlet end (65) received within the mixing chamber (34). [4] Intake manifold (30) according to claim 2 or 3, wherein the mixing chamber (34) has a smaller cross-sectional area of ​​fluid flow than the plenum (33). [5] Intake manifold (30) according to one of claims 2 to 4, wherein a length (L) of the mixing chamber (34) is more than 0.5 times the diameter of the valve disc (54), preferably more than 0.75 times the diameter of the valve disc (54). [6] Intake manifold (30) according to claim 1, wherein a distance between the outlet end (65) and the air intake valve (50) is less than 1.5 times the diameter of the valve disc (54). [7] Intake manifold (30) according to one of claims 1 to 6, wherein the secondary gas inlet (60) is constructed as an inlet pipe (61) comprising an injector portion (63) near the outlet end (65), and wherein at least the injector portion (63) of the secondary gas inlet pipe (61) extends along an injection axis (B; C) oriented in the second direction. [8] Intake manifold (30) according to claim 7, wherein the injection axis (B; C) intersects a central axis (A) of the air inlet duct (40) at an angle between -25° and 25°, preferably between -10° and 10°. [9] Intake manifold (30) according to claim 8, wherein a radial distance between the central axis (A) of the air intake duct (40) and the outlet end (65) of the secondary gas inlet pipe (61) is less than 0.25 times the diameter of the valve disc (54). [10] Intake manifold (30) according to claim 7, wherein the injection axis (B) is coaxially aligned with a central axis (A) of the air intake duct (40). [11] Intake manifold (30) according to one of claims 1 to 10, wherein the housing structure (31) comprises a second secondary gas inlet (70) arranged to discharge gas into the charge air in a third direction substantially perpendicular to the second direction. [12] Intake manifold (30) according to one of claims 1 to 11, wherein the secondary gas inlet (60) is a purge gas inlet connected to a tank venting control system. [13] Intake manifold (30) according to one of claims 1 to 11, wherein the secondary gas inlet (60) is a recirculation inlet connected to an exhaust gas recirculation system. [14] Intake manifold (30) according to one of claims 1 to 13, wherein the secondary gas inlet (60) is a passive gas inlet. [15] Intake manifold (30) according to one of claims 1 to 14, wherein the housing structure (31) comprises a second secondary gas inlet (70) arranged to discharge gas into the charge air in the second direction. [16] Intake manifold (30) according to claim 15, wherein the secondary gas inlet (70) is constructed as a second gas inlet pipe (71) and is arranged substantially parallel to an inlet pipe (61) of the first secondary gas inlet (60). [17] Intake manifold (30) according to one of claims 15 to 16, wherein the second secondary gas inlet (70) is a vent inlet connected to a crankcase ventilation system. [18] Intake manifold (30) according to one of claims 1 to 17, wherein the intake manifold (30) comprises a plurality of channels for fluidly connecting the plenum (33) to intake ports of the corresponding cylinder heads. [19] An internal combustion engine comprising the intake manifold (30) according to any one of claims 1 to 18. [20] An internal combustion engine according to claim 19, wherein the internal combustion engine is a direct injection engine. [21] An internal combustion engine according to claim 19 or 20, wherein the internal combustion engine is a gasoline engine. [22] A vehicle comprising an internal combustion engine according to any one of claims 19 to 21.

Images