阅读说明：本技术 每个汽缸带有两个阀门的直喷式内燃发动机 (Direct injection internal combustion engine with two valves per cylinder ) 是由 B·范登赫维尔 W·埃曼克 K·P·海因 A·霍普夫 J·邦泽 于 2019-06-05 设计创作，主要内容包括：本发明涉及具有汽缸盖(1)的直喷式内燃发动机,所述汽缸盖(1)包括成直列式布置的至少三个汽缸(3),在所述内燃发动机中-每个汽缸(3)具有进口开口,每个进口开口与进气管路(4)邻接,并且所述汽缸(3)的进气管路(4)合并以形成总进气管路(6),从而形成进气歧管(7),-每个汽缸(3)具有出口开口,每个出口开口与排气管路(8)邻接,-每个进口开口装备有进口阀,并且每个出口开口装备有出口阀,-每个汽缸(3)包括铰接地连接到曲轴的活塞,当所述曲轴围绕旋转轴线旋转时,所述活塞沿汽缸纵向轴线振荡,所述汽缸纵向轴线垂直于所述曲轴的所述旋转轴线,并且-每个汽缸(3)装备有喷嘴,用于将燃料直接引入所述汽缸(3)中。本发明旨在提供一种合适的内燃发动机,其特征在于改进的混合物形成并且提供令人满意的功率输出。此目的通过一种内燃发动机实现,所述内燃发动机的特征在于,汽缸专用的喷嘴被居中地布置,与汽缸纵向轴线没有间距,并且沿着所述汽缸纵向轴线定向。(The invention relates to a direct injection internal combustion engine having a cylinder head (1), the cylinder head (1) comprising at least three cylinders (3) arranged in line, in which internal combustion engine-each cylinder (3) has an inlet opening, each inlet opening adjoins an intake line (4), and the intake lines (4) of the cylinders (3) merge to form a total intake line (6), forming an intake manifold (7), -each cylinder (3) has an outlet opening, each outlet opening adjoins an exhaust line (8), -each inlet opening is equipped with an inlet valve, and each outlet opening is equipped with an outlet valve, -each cylinder (3) comprises a piston hingedly connected to a crankshaft, which piston oscillates along a cylinder longitudinal axis, which cylinder longitudinal axis is perpendicular to the axis of rotation of the crankshaft, when the crankshaft rotates about the axis of rotation, and-each cylinder (3) is equipped with an injection nozzle for introducing fuel directly into said cylinder (3). The present invention aims to provide a suitable internal combustion engine which is characterized by improved mixture formation and provides satisfactory power output. This object is achieved by an internal combustion engine which is characterized in that the cylinder-specific nozzle is arranged centrally, without a spacing from the cylinder longitudinal axis, and is oriented along the cylinder longitudinal axis.)

1. A direct injection internal combustion engine having a cylinder head (1), the cylinder head (1) comprising at least three cylinders (3) arranged in-line along a longitudinal axis (2) of the cylinder head (1), in which internal combustion engine

-each cylinder (3) having an inlet opening for supplying combustion air into the cylinder (3) via an intake system, each inlet opening being contiguous with an intake conduit (4), and the intake conduits (4) of the cylinders (3) merging to form a total intake conduit (6) forming an intake manifold (7),

-each cylinder (3) having an outlet opening for discharging the exhaust gases via an exhaust gas discharge system, each outlet opening being adjoined by an exhaust line (8),

Each inlet opening is equipped with an inlet valve and each outlet opening is equipped with an outlet valve,

-each cylinder (3) comprises a piston hingedly connected to a crankshaft, which piston oscillates along a cylinder longitudinal axis when the crankshaft rotates about an axis of rotation, which cylinder longitudinal axis is perpendicular to the axis of rotation of the crankshaft, and

-each cylinder (3) is equipped with an injection nozzle for introducing fuel directly into said cylinder (3), wherein

-the cylinder-specific nozzle is arranged centrally, without a spacing from the cylinder longitudinal axis, and is oriented along the cylinder longitudinal axis.

2. The direct injection internal combustion engine according to claim 1, wherein the cylinder head (1) comprises three or five cylinders (3) arranged in-line, the intake manifold (7) having an asymmetric design such that the total intake conduit (6) is arranged eccentrically with respect to the manifold (7).

3. The direct injection internal combustion engine according to claim 1 or 2, wherein the cylinder head (1) comprises three cylinders (3), two of which (c/l: (d))3) Is an outer cylinder (3 a)₁、3a₂) And one cylinder (3) is an inner cylinder (3b), said inner cylinder (3b) being arranged between said two outer cylinders (3 a)₁、3a₂) In the meantime.

4. The direct injection internal combustion engine according to claim 3, wherein adjacent to the first outer cylinder (3 a)₁) The traction mechanism drive is arranged on the front side (5) of the cylinder head (1).

5. The direct injection internal combustion engine according to claim 3 or 4, wherein the intake pipe (4) of the cylinder (3) merges to the inner cylinder (3b) and the outer cylinder (3 a)₁、3a₂) Centrally forming said total inlet line (6).

6. The direct injection internal combustion engine according to claim 5, wherein the intake conduit (4) of the cylinder (3) merges to the inner cylinder (3b) and the second outer cylinder (3 a)₂) Centrally forming said total inlet line (6).

7. The direct injection internal combustion engine according to claim 5 or 6, wherein the intake pipe (4) and the outer cylinder (3 a) of the inner cylinder (3b)₁、3a₂) Has a symmetrical form, in particular with respect to a central plane S, which is located between the two cylinders (3 a)₁、3a₂3b) and perpendicular to the longitudinal axis (2) of the cylinder head (1), the total intake line (6) being arranged centrally in the intake line (4) of the inner cylinder (3b) and in the outer cylinder (3 a)₁、3a₂) Between said inlet lines (4).

8. The direct injection internal combustion engine according to claims 3 to 7, wherein the first outer cylinder (3 a)₁) First of all, and then they jointly with the second outer cylinder (3 a) and then the intake pipe (4) of the inner cylinder (3b)₂) Is/are as followsThe intake lines (4) merge to form the total intake line (6).

9. The direct injection internal combustion engine according to claims 4 to 8, wherein a generator is provided between the front side (5) of the cylinder head (1) and the total intake pipe (6).

10. the direct injection internal combustion engine according to claim 1, wherein the cylinder head (1) comprises four cylinders (3) arranged in-line, the intake manifold (7) having a symmetrical design such that the total intake conduit (6) is arranged centrally with respect to the manifold (7).

11. The direct injection internal combustion engine according to claim 2, wherein the cylinder head (1) comprises five cylinders (3), two of which (3) are outer cylinders (3) and one cylinder (3) is a central cylinder (3), in each case one inner cylinder (3) being arranged between a centrally located cylinder (3) and an outer cylinder (3).

12. The direct injection internal combustion engine according to claim 11, wherein adjacent to a first outer cylinder (3) a traction mechanism drive is provided on the front side (5) of the cylinder head (1).

13. The direct injection internal combustion engine according to claim 11 or 12, wherein the intake conduits (4) of the cylinders (3) merge to form the total intake conduit (6) centrally between the central cylinder (3) and an inner cylinder (3).

14. The direct injection internal combustion engine according to claim 12 or 13, wherein the intake conduits (4) of the cylinders (3) merge to form the total intake conduit (6) centrally between the central cylinder (3) and an inner cylinder (3) adjacent to the first outer cylinder (3).

15. The direct injection internal combustion engine according to claim 13 or 14, wherein the intake conduit (4) of the central cylinder (3) and the intake conduit (4) of the inner cylinder (3) have a symmetrical form, in particular with respect to a central plane S extending centrally between the two cylinders (3) and perpendicular to the longitudinal axis (2) of the cylinder head (1), the total intake conduit (6) being arranged centrally between the intake conduit (4) of the central cylinder (3) and the intake conduit (4) of the inner cylinder (3).

16. The direct injection internal combustion engine according to any one of the preceding claims, wherein the intake conduits (4) merge to form a total intake conduit (6) within the cylinder head (1).

17. The direct injection internal combustion engine according to any one of the preceding claims, wherein the inlet valve and the outlet valve are spaced from each other in an inline arrangement along an axis (2) of the cylinder head (1), the axis (2) of the cylinder head (1) extending parallel to the rotational axis of the crankshaft.

18. The direct injection internal combustion engine of any one of the preceding claims, wherein a common camshaft is provided for actuating the inlet valve and the outlet valve.

19. The direct injection internal combustion engine according to claim 18, wherein the common camshaft is arranged eccentrically and at the outlet side and mounted on the cylinder head (1).

20. The direct injection internal combustion engine of claim 19, wherein the inlet and outlet valves are inclined relative to an associated cylinder longitudinal axis.

21. The direct injection internal combustion engine according to any one of the preceding claims, wherein the cylinder head (1) is equipped with at least one coolant jacket so as to form a liquid type cooling arrangement.

Technical Field

The present invention relates to a direct injection internal combustion engine having a cylinder head comprising at least three cylinders arranged in-line along a longitudinal axis of the cylinder head, in which internal combustion engine

Each cylinder having an inlet opening for supplying combustion air into the cylinder via an intake system, each inlet opening being contiguous with an intake conduit and the intake conduits of the cylinders merging to form an overall intake conduit, thereby forming an intake manifold,

Each cylinder having an outlet opening for discharging exhaust gases via an exhaust gas discharge system, each outlet opening being contiguous with an exhaust line,

each inlet opening is equipped with an inlet valve and each outlet opening is equipped with an outlet valve,

Each cylinder comprises a piston hingedly connected to the crankshaft, the piston oscillating along a cylinder longitudinal axis when the crankshaft rotates about an axis of rotation, the cylinder longitudinal axis being perpendicular to the axis of rotation of the crankshaft, and

Each cylinder is equipped with a nozzle for introducing fuel directly into the cylinder.

Internal combustion engines of the type described above are used, for example, as drives for motor vehicles.

Background

within the scope of the present invention, the term "internal combustion engine" covers auto-ignition diesel engines, but also hybrid internal combustion engines, i.e. internal combustion engines which are operated by a hybrid combustion process with auto-ignition, and hybrid drives which, in addition to the auto-ignition internal combustion engine, comprise at least one further torque source for driving the motor vehicle, for example an electric machine which can be connected in terms of drive or which is connected in terms of drive to the auto-ignition internal combustion engine and which outputs power instead of or in addition to the internal combustion engine.

An internal combustion engine according to the present invention has a cylinder block and a cylinder head connected to each other to form at least three cylinders or combustion chambers. In order to make a satisfactory connection (i.e. a connection sealing the combustion chamber between the cylinder head and the cylinder block), a sufficient number of sufficiently large bores must be provided, which affects and complicates, among other things, the structural design of the cylinder head.

The cylinder block, which is the upper crankcase half, serves to house the pistons and cylinder liners of the cylinders. A crankshaft mounted in the crankcase absorbs the connecting rod forces and converts the oscillating stroke motion of the piston into a rotational motion of the crankshaft. In order to hold and mount the crankshaft, at least two bearings are provided in the crankcase.

The cylinder head is typically used to house the valve actuators required for the charge exchange. For actuating the valve, it is usually the case that first a valve spring is provided for preloading the valve in the direction of the valve closed position, and then a valve actuating device is provided for opening the valve against the preload force of the valve spring.

Here, the valve actuating device usually comprises a camshaft with cams, wherein an overhead camshaft, i.e. a camshaft located above the separating plane between the cylinder head and the cylinder block, is usually mounted on the cylinder head. As another valve drive component, the valve actuation device may include a rocker arm, a finger-type rocker, or a tappet as a cam follower element.

During the charge exchange process, the discharge of combustion gases via the exhaust gas discharge system takes place via the outlet openings of the cylinders, and the supply of combustion air via the intake system takes place via the inlet openings of the cylinders. According to the prior art, in four-stroke engines, for controlling the charge exchange, only a poppet valve is actually used, which is movable along its longitudinal axis between a valve-closed position and a valve-open position and which, during operation of the internal combustion engine, performs an oscillating lifting movement in order to open and close the inlet and outlet openings.

The actuating mechanism required for the valve, including the valve, is referred to as the valve driver. The purpose of the valve drive here is to open and close the cylinder opening of the cylinder at the correct time, while seeking a quick opening of the largest possible flow cross section in order to keep the throttling losses in the inflowing and outflowing gas flow low and in order to ensure the best possible charging of the cylinder, and an efficient (i.e. complete) discharge of the combustion gases.

For this reason, the cylinders of internal combustion engines are usually equipped with two or more inlet openings and two or more outlet openings.

The invention relates to an internal combustion engine having only one inlet opening and only one outlet opening per cylinder, thereby simplifying the structure of the internal combustion engine and enabling cost reduction. In contrast, charge exchange (particularly charging the cylinder with combustion air) is impeded, and therefore problems are encountered in achieving satisfactory power output. In order to improve the charge exchange, it is sought to design the inlet and outlet openings as large as possible.

However, large design cylinder openings often make it difficult to achieve a favorable centering arrangement of the cylinder-specific nozzles. The invention relates to an internal combustion engine, in particular to a direct injection internal combustion engine.

the time available for injection of fuel, preparation of the mixture in the combustion chamber (in particular thorough mixing of air and fuel and preparation of fuel in the case of preliminary reactions involving evaporation) and ignition of the prepared mixture is relatively small, for which reason a method of mixture formation is required in the case of direct injection of fuel, by means of which method the mixture formation is assisted and accelerated in order to render the fuel-air mixture substantially homogeneous before ignition.

good thorough mixing of the intake air with the injected fuel can be achieved if the inlet flow (when air is drawn into the combustion chamber) has a motion forced onto it, thereby creating a charge motion in the combustion chamber.

For example, the generation of so-called tumbling or swirling flows can accelerate and contribute to the mixture formation. The vortex is a vortex of air whose axis extends parallel and therefore generally coaxially with respect to the piston longitudinal axis (i.e., the cylinder longitudinal axis). In contrast, tumble is a vortex of air around an imaginary axis that extends transversely or perpendicularly with respect to the cylinder longitudinal axis and according to the prior art parallel to the longitudinal axis (i.e., the rotational axis of the crankshaft).

The arrangement and geometry of the intake system (i.e. the intake line) has a significant influence on the charge movement and thus on the mixture formation, wherein the charge movement in the cylinder is simultaneously influenced by the geometry of the combustion chamber, in particular by the geometry of the piston crown or of the piston recess optionally provided therein. According to the prior art, in the case of direct-injection internal combustion engines, recesses which are rotationally symmetrical to the longitudinal axis of the piston, in particular omega-shaped recesses, are generally used. Due to the shrinking spatial conditions in the cylinder head, optimization of the intake line with respect to mixture formation and charge exchange may not be possible, or may not be entirely possible.

according to the prior art, the intake line leading to the inlet opening and the exhaust line adjoining the outlet opening are at least partially integrated in the cylinder head and usually merge in each case so as to form at least one manifold.

In the case of the internal combustion engine to which the invention relates, the intake lines are merged to form a total intake line, thus forming an intake manifold.

Usually, the exhaust lines of the cylinders merge within the cylinder head in order to form an integrated exhaust manifold, that is to say the exhaust manifold is fully integrated in the cylinder head. Cylinder heads of the type described are also characterized by a very compact design, which allows a dense packing of the drive unit as a whole. Furthermore, the exhaust manifold can benefit from a liquid type cooling arrangement that may be provided in the cylinder head, so that the manifold does not need to be manufactured from thermally highly loadable and therefore expensive materials.

The use of a cylinder head with an integrated manifold also results in a reduction in the number of components, thereby reducing costs, particularly assembly and procurement costs.

The cylinder heads of modern internal combustion engines usually have a higher thermal load and therefore also place higher demands on the cooling arrangement, especially if the cylinder heads are equipped with an integrated exhaust manifold and/or the internal combustion engine is a supercharged internal combustion engine.

If the internal combustion engine has a liquid cooling arrangement, forming at least one coolant jacket in the cylinder head, which coolant jacket conducts coolant through the cylinder head; this requires a relatively complex cylinder head structure.

The above statements clearly show that the cylinder head of an internal combustion engine is a thermally and mechanically highly loaded component. In this case, it must be taken into account that an increased proportion of the internal combustion engine is supercharged by means of an exhaust-gas turbocharger or supercharger. The thermal load of internal combustion engines and cylinder heads in particular increases due to the denser packing in the engine compartment and the increasing integration of parts and components into the cylinder head (e.g. integration of the exhaust manifold), so that higher demands are placed on the cooling system.

In the case of a direct injection internal combustion engine, it is also necessary for the injection device of each cylinder to be arranged in the cylinder head near the combustion chamber. This is problematic in particular in the case of internal combustion engines with two valves per cylinder, in which case the inlet and outlet openings should be designed as large as possible in order to achieve a satisfactory charge exchange, that is to say in order to ensure good charging of the cylinders and effective discharge of the combustion gases.

According to the prior art, the spatial conditions of the shrinkage in the cylinder head have the effect of: the nozzles are arranged eccentrically and so as to be inclined with respect to the longitudinal axis of the cylinder. This arrangement of the nozzles hinders the widest and uniform possible distribution of the fuel in the fuel chamber. This is very detrimental to mixture formation and homogenization of the fuel-air mixture.

Disclosure of Invention

On the background of the above, it is an object of the present invention to provide a direct injection internal combustion engine with two valves per cylinder according to the preamble of claim 1, which is characterized by an improved mixture formation and provides a satisfactory power output.

This object is achieved by a direct injection internal combustion engine having a cylinder head comprising at least three cylinders arranged in-line along a longitudinal axis of the cylinder head, in which internal combustion engine

-each cylinder having an inlet opening for supplying combustion air into the cylinder via an intake system, each inlet opening being contiguous with an intake conduit and the intake conduits of the cylinders merging to form a total intake conduit, forming an intake manifold,

Each cylinder having an outlet opening for discharging the exhaust gases via an exhaust gas discharge system, each outlet opening being contiguous with an exhaust line,

Each inlet opening is equipped with an inlet valve and each outlet opening is equipped with an outlet valve,

-each cylinder comprises a piston hingedly connected to a crankshaft, the piston oscillating along a cylinder longitudinal axis when the crankshaft rotates about an axis of rotation, the cylinder longitudinal axis being perpendicular to the axis of rotation of the crankshaft, and

Each cylinder is equipped with a nozzle for introducing fuel directly into said cylinder,

And the internal combustion engine is characterized in that:

-the cylinder-specific nozzle is arranged centrally, without a spacing from the cylinder longitudinal axis, and is oriented along the cylinder longitudinal axis.

Each cylinder of the internal combustion engine according to the invention is equipped with a nozzle which is arranged centrally in the cylinder, i.e. in the middle of the cylinder, in particular without a spacing from the longitudinal axis of the cylinder. Furthermore, the nozzle is oriented along the longitudinal axis of the cylinder and thus in the direction of the piston crown.

This arrangement of the nozzles ensures or allows a wide and uniform distribution of the fuel in the combustion chamber, thereby facilitating mixture formation in the cylinder, in particular homogenization of the fuel-air mixture within the short time available.

The object on which the invention is based is therefore achieved by providing a direct injection internal combustion engine with two valves per cylinder, which is characterized by improved mixture formation and provides satisfactory power, according to the preamble of claim 1.

Further advantageous embodiments of the direct injection internal combustion engine will be discussed in conjunction with the dependent claims.

Embodiments of the direct injection internal combustion engine in which the cylinder head comprises three or five cylinders arranged in-line and the intake manifold has an asymmetric design such that the total intake conduit is arranged eccentrically with respect to the manifold are advantageous.

in the present case, the cylinder head has an intake manifold of asymmetrical design, in which case the total intake line is not arranged centrally in the manifold but rather eccentrically.

in this way, in the case of a cylinder head having three, four, or five cylinders, the total intake pipe can be arranged at an equal pitch to the front face side of the cylinder head. This provides an advantage, for example, if the traction mechanism drive is provided on the front side of the cylinder head and a generator which can be driven by the traction mechanism drive is to be arranged between the front side and the total intake line.

Regardless of the respective number of cylinders, structurally identical generators may be used, which are positioned in cylinder heads with different numbers of cylinders and fastened at the same location and interlinked or connected with the rest of the structure around the generator.

What has been stated above applies to, for example, engine families that include cylinder heads with three, four and five cylinders. In the case of a cylinder head with four cylinders, the intake manifold will be of a symmetrical form, so that the total intake line is arranged centrally between the two inner cylinders, that is to say between the second and third cylinders. In the case of cylinder heads with three and five cylinders, the intake manifold will be of asymmetric form, in particular so that the total intake line is arranged eccentrically, but also between the second and third cylinders, with the cylinders numbered consecutively from the front side of the cylinder head, from one to three or from one to five.

The eccentric arrangement of the total intake pipe, i.e. the intake manifold according to the invention in an asymmetrical form, can also be advantageously used with other components of the internal combustion engine (in particular auxiliary assemblies), in particular whenever it is possible to benefit from: the total intake line is arranged in a constant manner between the second and third cylinders, irrespective of the number of cylinders of the cylinder head. These may also include a high-pressure pump of the direct fuel injection device and/or a compressor of the air conditioning system, which may be installed in a constant manner regardless of the number of cylinders, as long as the generator is located at the same position. In this case, mention must also be made of compressors of the supercharging arrangement.

Embodiments of the direct injection internal combustion engine in which the cylinder head has three cylinders, two of which are outer cylinders and one of which is an inner cylinder, the inner cylinder being arranged between the two outer cylinders are advantageous.

In the case of a three-cylinder inline engine, the cylinders have an offset of 240 ° ca with respect to their operation, so that charge exchange (in particular the supply of combustion air) takes place successively, that is to say separately from one another, and possibly also with an overlap, which is however small. The eccentric arrangement of the overall intake pipe (i.e. the asymmetric form of the intake manifold) does not generally affect charge exchange.

In this case, an embodiment of the direct injection internal combustion engine is advantageous in which the traction mechanism drive is provided on the front side of the cylinder head adjacent to the first outer cylinder. To distinguish between the two outer cylinders, the two cylinders are numbered and in the present case referred to as the first and second outer cylinders. The first outer cylinder is the first cylinder if the cylinders are numbered consecutively from one to three from the front side of the cylinder head.

A belt drive and a chain drive may be used as the traction mechanism drive, in which case a belt or a chain, respectively, is used as the traction mechanism. In general, a portion of the power obtained in an internal combustion engine as a result of the chemical conversion of the fuel is used to drive the camshaft required for the control valves of an auxiliary component (in particular an injection pump, an oil pump, a coolant pump, an alternator or generator, etc.) or a valve drive required for the operation of the internal combustion engine or of the motor vehicle.

The traction mechanism drive generally comprises, in addition to the traction mechanism, a drive wheel arranged on the crankshaft of the internal combustion engine and at least one further wheel arranged on the shaft of the auxiliary assembly, wherein the traction mechanism is guided around the wheels. A tensioning device is generally provided which exerts a force on the traction mechanism, engages into the traction mechanism so as to form a contact zone, and thus tensions the traction mechanism.

In the case of a cylinder head with three cylinders, an embodiment is advantageous in which the intake lines of the cylinders merge to form a total intake line centrally between the inner and outer cylinders.

In the case of cylinder heads of the same engine series with four cylinders, the intake manifold may be of symmetrical form, so that the total intake line is arranged centrally between the two inner cylinders, that is to say between the second and third cylinders.

In this case, an embodiment of the direct-injection internal combustion engine in which the intake lines of the cylinders merge to form a total intake line centrally between the inner cylinder and the second outer cylinder is therefore also advantageous. The second outer cylinder is in the present case the third cylinder if the cylinders are numbered consecutively from one to three from the front side of the cylinder head.

In the case of a cylinder head with three cylinders, in which the intake conduits of the cylinders merge to form a total intake conduit centrally between the inner and outer cylinders, embodiments are advantageous in which the intake conduits of the inner and outer cylinders have a symmetrical form, in particular with respect to a central plane S which extends centrally between the two cylinders and is perpendicular to the longitudinal axis of the cylinder head, the total intake conduit being arranged centrally between the intake conduits of the inner and outer cylinders.

In the case of a cylinder head of the same engine series with four cylinders, then the intake manifold will be of symmetrical form, so that the intake conduit of the manifold is of symmetrical form with respect to a central plane S arranged centrally between the two inner cylinders, i.e. between the second and third cylinders.

in the case of a cylinder head with three cylinders arranged in-line, an embodiment is advantageous in which the intake lines of the first outer cylinders and the intake lines of the inner cylinders merge first, and then they merge jointly with the intake lines of the second outer cylinders to form a total intake line.

In the case of a cylinder head with three cylinders (with the traction mechanism drive adjacent to the first outer cylinder being arranged on the front side of the cylinder head), an embodiment is advantageous in which the generator is arranged between the front side of the cylinder head and the total intake line.

in the case of a cylinder head with three cylinders arranged in line, an embodiment is advantageous in this case in which the intake lines of the first outer cylinders and the intake lines of the inner cylinders merge first, and then they merge jointly with the intake lines of the second outer cylinders to form a total intake line.

Embodiments of a direct injection internal combustion engine in which the cylinder head comprises four cylinders arranged in-line and the intake manifold has a symmetrical design such that the total intake conduit is centrally disposed with respect to the manifold may also be advantageous. Reference is made to the explanations already given in connection with the four-cylinder in-line engine, in particular to the salient advantages that arise if the four-cylinder in-line engine belongs to the engine family.

Embodiments of such a direct injection internal combustion engine may also be advantageous, wherein the cylinder head comprises five cylinders, two of which are outer cylinders and one of which is a central cylinder, in each case one inner cylinder being arranged between the centrally located cylinder and the outer cylinder.

In this case, an embodiment of the direct injection internal combustion engine is advantageous in which the traction mechanism drive is arranged on the front side of the cylinder head adjacent to the first outer cylinder.

In the case of a cylinder head with five cylinders arranged in-line, an embodiment is advantageous in which the intake lines of the cylinders merge to form a total intake line centrally between the central cylinder and the inner cylinder.

Embodiments of the direct injection internal combustion engine in which the intake conduits of the cylinders merge to form a total intake conduit centrally between the central cylinder and the inner cylinder adjacent to the first outer cylinder are particularly advantageous. In the present case, the first outer cylinder is the first cylinder if the cylinders are numbered consecutively from one to five from the front side of the cylinder head.

in this case, an embodiment of the direct injection internal combustion engine is advantageous in which the inlet line of the central cylinder and the inlet line of the inner cylinder have a symmetrical form, in particular with respect to a central plane S which extends centrally between the two cylinders and is perpendicular to the longitudinal axis of the cylinder head, the total inlet line being arranged centrally in the inlet line of the central cylinder and in the inlet line of the inner cylinder.

Embodiments of the direct injection internal combustion engine in which the intake conduits merge to form a total intake conduit within the cylinder head are advantageous.

The intake lines of the cylinders then merge to form an overall intake line in such a way that an intake manifold integrated in the cylinder head is formed. This measure results in a small volume and a small surface area of the intake system in the region of the intake manifold, with the advantages described above. Furthermore, assembly is simplified and results in cost advantages.

The compressor of the exhaust-gas turbocharger can be positioned close to the inlet opening of the cylinder, ensuring good response behavior of the internal combustion engine. The volume of the pipe system between the inlet opening of the cylinder and the compressor is further reduced.

A plurality of additional lines (e.g. a bypass line of a charge air cooler, a bypass line of a compressor or a recirculation line of an external exhaust gas recirculation arrangement) may enter the air intake system or the total air intake line.

Exhaust gas recirculation (i.e., recirculation of combustion gases from the exhaust gas emission system into the intake system) is a concept to reduce nitrogen oxide emissions, which may decrease significantly with increasing exhaust gas recirculation rates. If the exhaust gas is recirculated, the combustion air comprises not only fresh air but also exhaust gas.

However, embodiments of direct injection internal combustion engines may also be advantageous in which the intake conduits merge to form a total intake conduit external to the cylinder head.

Embodiments of the direct injection internal combustion engine in which the inlet and outlet valves are spaced from one another in an inline arrangement along an axis of the cylinder head, which axis extends parallel to the axis of rotation of the crankshaft, are advantageous. The longitudinal axis of the cylinder head is a specific axis, extending parallel to the axis of rotation of the crankshaft, and relative to the other axes of the cylinder head, characterized in that it intersects the longitudinal axis of the cylinder.

The two cylinder-specific valves are not arranged in pairs opposite to each other on different sides of the crankshaft, but rather are arranged along the crankshaft. All valves of the cylinder head according to the above described embodiments are arranged one after the other along an axis or the longitudinal axis of the cylinder head and thus in the direction of the crankshaft. The valve is arranged along an axis which extends parallel to the longitudinal axis of the crankshaft and also forms the axis of rotation of the crankshaft.

This structural feature forms the basis of an inexpensive concept. Here, the inlet valves and the outlet valves of the cylinders can basically be actuated by a common single camshaft.

The valves, which are arranged one after the other in the direction of the crankshaft in a row, regardless of the shrinking spatial conditions in the cylinder head, make it possible for the intake line leading to the inlet opening to be provided in a form which permits or ensures the formation of a charging movement when the inlet opening is open during the course of the charge exchange. As already mentioned, the arrangement and geometry of the inlet line has a significant influence on the charge movement in the cylinder.

For the reasons stated above, embodiments of such a direct injection internal combustion engine are advantageous in which a common camshaft is provided for actuating the inlet and outlet valves.

In this case, an embodiment of the direct injection internal combustion engine is advantageous in which the common camshaft is arranged eccentrically and at the outlet side and is mounted on the cylinder head.

This concept generally leads to a longer intake line and a shorter exhaust line, but also improves the charge exchange and thus leads to a greater power output, since the throughflow behavior of the inlet opening is less sensitive in terms of the oblique arrangement of the inlet valve relative to the intake line than in the case of the exhaust line and the associated outlet valve. In this case, it must be taken into account that the inlet line is designed with a view to the charge movement in the cylinder (generally so as to have a spiral configuration) and that the outlet line generally has a more rectilinear form.

However, an embodiment of a direct injection internal combustion engine in which the common camshaft is arranged eccentrically and at the inlet side and is mounted on the cylinder head may also be advantageous.

Although the common camshaft is preferably mounted in the cylinder head, it can basically also be mounted in a separate camshaft carrier unit.

In this case, embodiments of the direct injection internal combustion engine are advantageous in which the inlet and outlet valves are inclined relative to the associated cylinder longitudinal axis.

Embodiments of the direct injection internal combustion engine in which the cylinder head is equipped with at least one coolant jacket so as to form a liquid-type cooling arrangement are advantageous.

Drawings

The invention will be described in more detail below on the basis of two exemplary embodiments and according to fig. 1 and 2. In the drawings:

FIG. 1 schematically shows in plan view an intake and exhaust line of a first embodiment of a cylinder head of a direct injection internal combustion engine, the cylinder head comprising three cylinders, an

Fig. 2 schematically shows in plan view an intake and an exhaust line of a second embodiment of a cylinder head of a direct injection internal combustion engine, the cylinder head comprising four cylinders.

Detailed Description

Fig. 1 schematically shows in plan view an intake line 4 and an exhaust line 8 of a first embodiment of a cylinder head 1 of a direct injection internal combustion engine, the cylinder head 1 comprising three cylinders 3.

The cylinder head 1 has three cylinders 3 arranged along the longitudinal axis 2 of the cylinder head 1 or parallel to the cylinder head longitudinal axis 2, i.e. in-line, and thus two outer cylinders 3a₁、3a₂And an inner cylinder 3 b.

Starting from the front side 5 of the cylinder head 1, the first cylinder 3 forms a first outer cylinder 3a if the cylinders 3 are numbered consecutively from one to three₁The second cylinder 3 forming an inner cylinder 3b and the third cylinder 3 forming a second outer cylinder 3a₂。

Each cylinder 3 has an inlet opening for supplying combustion air via the intake system, each inlet opening being adjacent to an intake line 4. The intake lines 4 of the cylinders 3 merge to form a total intake line 6, forming an intake manifold 7. The intake manifold 7 has an asymmetrical form, in particular such that the total intake pipe 6 is arranged eccentrically with respect to the manifold 7.

The intake conduits 4 of the three cylinders 3 merge into an inner cylinder 3b (i.e. the second cylinder 3) and a second outer cylinder 3a₂(i.e. the third cylinder 3) forms a total inlet line 6 centrally between them.

The inlet line 4 of the inner cylinder 3b and the second outer cylinder 3a₂Has a symmetrical form with respect to a central plane S in the two cylinders 3a₁、3a₂Extending centrally between and perpendicular to the longitudinal axis 2 of the cylinder head 1, a total inlet line 6 being centrally arranged in the inlet line 4 of the inner cylinder 3b and the second outer cylinder 3a₂between the inlet lines 4.

In order to discharge the exhaust gases via an exhaust-gas discharge system, each cylinder 3 is equipped with an outlet opening, which adjoins in each case one exhaust line 8.

Fig. 2 schematically shows in plan view an intake line 4 and an exhaust line 8 of a second embodiment of a cylinder head 1 of a direct injection internal combustion engine, the cylinder head 1 comprising four cylinders 3. It is merely sought to explain additional features related to fig. 1, for which reason reference is made to fig. 1 and the associated description. The same reference numerals have been used for the same components.

The intake manifold 7 has a symmetrical form such that the total intake line 6 is arranged centrally with respect to the manifold 7. The inlet lines 4 of the four cylinders 3 merge centrally between the two inner cylinders 3, i.e. between the second cylinder 3 and the third cylinder 3. This results in a common feature with respect to the intake manifold 7 shown in fig. 1, in particular with respect to the arrangement of the overall intake line 6.

The illustrated intake manifold 7 of the four-cylinder inline engine also shows the starting point of the structural design according to the embodiment of fig. 1.

This is advantageous for achieving the object of creating as many common features as possible in an engine series comprising cylinder heads 1 with different numbers of cylinders 3 in the structural design of the intake system.

Starting from the intake manifold 7 of a four-cylinder in-line engine as shown in fig. 2, the intake line 4 of the fourth cylinder 3 is omitted in order to reach the intake manifold 7 of fig. 1.

It can also be seen that the inlet line 4 is longer than the outlet line 8.

Reference mark

1 Cylinder head

Cylinder head longitudinal axis, parallel to cylinder head longitudinal axis

3 cylinder

3a₁First outer cylinder

3a₂Second outer cylinder

3b inner cylinder

4 air inlet pipeline

5 front side of cylinder head

6 total air inlet pipeline

7 air intake manifold

8 exhaust pipeline

S reference plane of air inlet pipeline