Cylinder head for an internal combustion engine and an internal combustion engine with such a cylinder head

Abstract

Cylinder head (5) for an internal combustion engine (1), comprising: a cylinder head assembly having an inlet channel (7) with a combustion chamber inlet opening (9), an injector (18) connected to the cylinder head assembly, and a tubular injection tube (19) extending along a tubular liner (L19) into the inlet channel (7) and fluidically connected to the injector (18), characterized in that an attachment element (21) is arranged on the injection tube (19), and that the attachment element (21) has an air guide section (25, 26, 27) extending radially outwards with respect to the tubular liner (L19) such that the flow in the inlet channel (7) is influenced by the air guide section (25, 26, 27).

Description

[0001] The present invention relates to a cylinder head for an internal combustion engine and an internal combustion engine having such a cylinder head.

[0002] The cylinder head of an internal combustion engine encloses the combustion chambers on the side opposite the piston and typically includes the intake and exhaust ports, as well as the valve control for the gas exchange processes within the engine. In engines with port fuel injection, fuel is injected into the intake port, forming a mixture of fuel and intake air in the intake port.

[0003] From EP 0 694 124 B1 an internal combustion engine with intake manifold injection is known in which fuel is injected into the intake port via a tube.

[0004] At the end opening into the intake port, the tube includes an atomizing screen that atomizes the fuel flowing out of the tube to improve fuel mixture formation. This has the disadvantage that the atomizing screen can become clogged during continuous operation, impairing fuel delivery. Furthermore, fuel can be retained in the tube by the atomizing screen, which can lead to unwanted backfiring, particularly when hydrogen is used as fuel.

[0005] Based on this, the present invention is based on the object of providing a cylinder head for an internal combustion engine and an internal combustion engine with such a cylinder head, which enables a permanently favorable mixture formation in the intake channel.

[0006] To achieve the object, a cylinder head for an internal combustion engine, in particular for a hydrogen-powered internal combustion engine, is proposed, comprising: a cylinder head arrangement having an inlet channel, an injector connected to the cylinder head arrangement, and a tubular injection tube extending along a tube core into the inlet channel and fluidically connected to the injector, wherein an attachment element is arranged on the injection tube, and the attachment element has an air guide section which extends radially outward with respect to the tube core such that a flow in the inlet channel is influenced by the air guide section.

[0007] The radially outwardly extending air guide section creates a more turbulent flow in the intake air downstream of the air guide section, which enables improved mixing of the intake air with the fuel injected into the intake port via the injection tube. Due to the radially outwardly extending arrangement of the air guide section, the injection tube is not blocked by the air guide section, so that the injection tube neither becomes clogged nor does it retain fuel in the injection tube as operation progresses.

[0008] In one possible embodiment, a radial extension of the air guiding section with respect to the tube core may be greater than an axial extension in the direction of the tube core.

[0009] The air guide section can be designed, in particular, as an air guide plate. In this case, its extension along a circumference around the tube core can be smaller than its radial extension relative to the tube core.

[0010] In a further embodiment, the attachment element may have a first connecting portion with which the attachment element is arranged on the injection tube.

[0011] The air guiding section may extend radially outward from the first connecting section with respect to the tube core.

[0012] An embodiment is possible in which the smallest cylindrical envelope of the first connecting section, whose cylinder axis is arranged coaxially to the tube core, has a smaller radius than the largest radial distance of the air guiding section from the tube core.

[0013] In another possible embodiment, the attachment element can have a second connecting section that rests against a wall of the intake duct. The first connecting section and the second connecting section can be connected to each other via the air guide section. Forces acting on the injection tube, for example, mass inertia forces caused by external vibrations, can thus be supported by the attachment element on the wall of the intake duct. This reduces the stress on the injection tube, particularly in a transition area to the injector, and accordingly increases the service life of the injection tube.

[0014] In another possible embodiment, the injection tube may have an injection opening that opens into the intake channel. The attachment element may be arranged between the injector and the injection opening.

[0015] In another possible embodiment, the cylinder head can comprise a first valve that can selectively open and close a first combustion chamber opening of the intake port. The first valve can have a valve plate and a valve stem extending along a first valve axis. The injection opening can be arranged, at least in sections, within a smallest cylindrical envelope of the valve plate of the first valve, which envelope is coaxial with the first valve axis. In other words, the injection opening can be arranged within an imaginary cylinder defined by a base area of ​​the cylinder plate and the valve axis.

[0016] In an alternative embodiment, the cylinder head may comprise a first valve that can selectively open and close a first combustion chamber opening of the intake port, the first valve having a valve disk and a valve stem extending along a first valve axis, and a second valve that can selectively open and close a second combustion chamber opening of the intake port, the second valve having a valve disk and a valve stem extending along a second valve axis. In this case, the injection opening may be arranged between a first imaginary plane defined by the first valve axis and a perpendicular to the tube core, and a second imaginary plane in which the second valve axis lies and which extends parallel to the first imaginary plane.

[0017] To achieve the object, an internal combustion engine is further proposed which comprises a cylinder head in a previously described embodiment.

[0018] In the following, possible embodiments of a cylinder head or an internal combustion engine according to the invention are explained with reference to the drawings.

[0019] This shows: Fig. 1 is a schematic representation of a partial sectional view of an internal combustion engine with a first cylinder head according to the invention; Fig. 2 a front view of the first attachment element Fig. 1; Fig. 3 a sectional view of the first attachment element along the section line III-III in Fig. 2; Fig. 4 a front view of the second attachment element Fig. 1; Fig. 5 a sectional view of the second attachment element along the section line VV in Fig. 4; Fig. 6 a schematic representation of a partial sectional view of an internal combustion engine with a second cylinder head according to the invention.

[0020] In the Fig. 1 to 5, which are described together below, depict an internal combustion engine 1. The internal combustion engine 1 is operated, in particular, with hydrogen as fuel. The internal combustion engine 1 comprises a crankcase 2 connected to a cylinder head 5 according to the invention.

[0021] The crankcase 2 comprises, in a known manner, a variable combustion chamber 3, which is defined by a movable piston 4 and the cylinder head 5. The cylinder head 5 comprises a cylinder head assembly comprising a cylinder head base element 6 and a cylinder head cover (not shown), which are connected to one another.

[0022] An inlet port 7 and an exhaust port 10 are cast into the cylinder head base element 6. An air-fuel mixture can be supplied to the combustion chamber 3 via the inlet port 7. The inlet port 7 is delimited by a wall 8 and comprises a combustion chamber inlet opening 9 that opens towards the combustion chamber 3. The combustion chamber inlet opening 9 can be selectively opened or closed in a known manner by an inlet valve 12. For this purpose, the inlet valve 12 comprises an inlet valve plate 13, which is arranged in a valve seat of the combustion chamber inlet opening 9 when the combustion chamber inlet opening 9 is to be closed, and an inlet valve stem 14, which extends essentially cylindrically along a valve axis L12. The inlet valve 12 can be moved along the valve axis L12 by a corresponding valve train, which is arranged above the cylinder head base body 6.

[0023] The exhaust gases produced by the combustion of the air-fuel mixture in the combustion chamber 3 can flow out of the combustion chamber 3 via the exhaust channel 10. The exhaust channel 10 is delimited by a wall and comprises a combustion chamber outlet opening 11 that opens towards the combustion chamber 3. The combustion chamber outlet opening 11 can be selectively opened or closed in a known manner by an exhaust valve 30. For this purpose, the exhaust valve 15 comprises an exhaust valve disk 16, which is arranged in a valve seat of the combustion chamber outlet opening 11 when the combustion chamber outlet opening 11 is to be closed, and an exhaust valve stem 17, which extends essentially cylindrically along a valve axis L15. The exhaust valve 15 can be moved along the valve axis L15 by the valve train.

[0024] To form the air-fuel mixture, fuel is injected into the intake port 7 via an injector 18, which is connected to the cylinder head assembly, in particular to the cylinder head base element 6, via connecting means not shown. For this purpose, an outlet of the injector 18 is fluidically connected to an injection tube 19, which extends along a tube core L19 into the intake port 7. The injection tube 19 comprises an injection opening 20, which opens into the intake port 7. The injection tube 19 is angled in the present case and comprises a first straight end section on the injector 18 side and a second straight end section on the injection opening 20 side, which are connected to one another via a curved section. The tube core L19 extends completely from one end of the injection tube 19 to the opposite end, wherein the tube core L19 Fig. 1 is shown only in the area of ​​the second end section for the sake of clarity. It is also conceivable that the tube core could take on any other shape, for example, be completely straight or S-shaped.

[0025] In the present case, the injection opening 20 is arranged within an imaginary straight cylinder, the base area of ​​which is described by the inlet valve plate 13 and extends along the valve axis L12.

[0026] On the injection tube, in the area of ​​the second end section, there is a first attachment element 21, which is inserted into the Fig. 2 and Fig. 3, and a second attachment element 21', which is shown in the Fig. 4 and Fig. 5 is shown in detail. The first attachment element 21 and the second attachment element 21' are each arranged between the injection opening 20 of the injection tube 19 and the injector 18. The second attachment element 21' is arranged closer to the injection opening 20 along the tube core L19 than the first attachment element 21.

[0027] The first attachment element 21 comprises an annular first connecting portion 22, the inner contour of which is complementary to the outer contour of the injection tube 19. The first attachment element 21 is firmly connected to the injection tube 19. In the present case, the first attachment element 21 is pressed onto the injection tube 19. However, it is also conceivable that the two parts are joined in another way, for example, soldered or glued.

[0028] Starting from the first connecting section 22, a first air guide section 24, a second air guide section 25, and a third air guide section 26 each extend radially outward relative to the tube core L19. The three air guide sections 24, 25, and 26 each have a greater extension in the radial direction relative to the tube core L19 than in the axial direction. The air guide sections 24, 25, and 26 each have a smaller extension in the circumferential direction around the tube core L19 than in the radial and / or axial direction and can accordingly be referred to as air guide plates. The air guide sections 24, 25, and 26 are each shaped in such a way that the flow of intake air in the inlet duct 7 is influenced by them.

[0029] In the present case, the air guide sections 24, 25, and 26 are designed as flat air guide plates. However, the air guide sections 24, 25, and 26, or air guide plates, can also have a shape other than flat; for example, they can be curved or twisted in the direction of the tube core L19. The flow of the intake air in the inlet duct can thus be imparted with a swirling and / or rolling motion by the air guide sections 24, 25, and 26.

[0030] The first attachment element 21 also comprises an annular second connecting portion 23, which engages a portion of the wall 8 of the inlet channel 7. In the present case, the second connecting portion 23 is pressed into the inlet channel 7. However, it is also conceivable here that the connecting portion 23 is joined to the wall 8 of the inlet channel 7 in some other way.

[0031] The first connecting section 22 and the second connecting section 23 are firmly connected to one another via the air guide sections 24, 25, and 26. The injection tube 19 is thus supported on the wall 8 of the intake channel 7 via the first attachment element 21. Thus, forces acting on the injection tube 19, for example, in the case of vibrations of the internal combustion engine 1, the inertial force of the injection tube 19 itself, can be supported by the attachment element 21. Thus, the stress on the injection tube 19 can be reduced and the service life of the injection tube 19 can be increased accordingly.

[0032] The second attachment element 21' differs from the first attachment element 21 only in that, in addition to the first air guide section 24, the second air guide section 25, and the third air guide section 26, a fourth air guide section 27 is provided. In this respect, the above statements regarding the similarities in the context of the first attachment element 21 also apply analogously to the second attachment element 21'. Identical elements are provided with the same reference numerals.

[0033] The fourth air guide section 27 is arranged skew relative to the tube core L19. Along the tube core L19, the fourth air guide section 27 is angled relative to the tube core L19. Thus, along the tube core L19, the distance between the fourth air guide section 27 and the tube core L19 deviates from constant. In particular, the distance between the fourth air guide section 27 and the tube core L19 increases uniformly along the tube core L19.

[0034] The first attachment element 21 and the second attachment element 21' thus influence the flow of the intake air in the intake channel 27 in such a way that mixture formation is improved when the fuel is injected into the intake channel 7. Due to the arrangement of the two attachment elements 21, 21' away from the injection opening 20 of the injection tube 19, the cross-section through which the fuel can flow from the injection tube 19 into the intake channel 7 is not reduced, so that the flow of fuel through the attachment elements 21, 21' is not impeded, nor can the remaining cross-section become clogged with increasing operating time.

[0035] It is understood that, depending on the application, any combination of first attachment elements 21 and second shoulder elements 21' may be provided instead of the two attachment elements 21, 21'. In particular, exactly one first attachment element 21 or one second attachment element 21' may be provided.

[0036] In Fig. 6 shows a further embodiment of the internal combustion engine 1', which differs from the embodiment of the internal combustion engine 1 Fig. 1 by the shape of the inlet channel 7'. In Fig. 6 are accordingly the Fig. 1 identical elements are given the same reference numerals. In this respect, the above applies in the context of Fig. 1 to 5 regarding the similarities, what was said analogously also applies to the internal combustion engine of the Fig. 6.

[0037] An inlet port 7' is cast into the cylinder head base element 6'. The outlet port is in Fig.6 not shown. An air-fuel mixture can be supplied to the combustion chamber 3 via the inlet channel 7'. The inlet channel 7' is delimited by a wall 8' and comprises a first combustion chamber inlet opening 9 and a second combustion chamber inlet opening 9', each of which opens toward the combustion chamber 3.

[0038] The first combustion chamber inlet opening 9 can be selectively opened or closed in a known manner by a first inlet valve 12. For this purpose, the first inlet valve 12 comprises an inlet valve plate 13, which is arranged in a valve seat of the first combustion chamber inlet opening 9 when the first combustion chamber inlet opening 9 is to be closed, and an inlet valve stem 14, which extends essentially cylindrically along a first valve axis L12. The first inlet valve 12 can be moved along the first valve axis L12 by a corresponding valve train, which is arranged above the cylinder head base body 6.

[0039] The second combustion chamber inlet opening 9' can be selectively opened or closed in a known manner by a second inlet valve 12'. For this purpose, the second inlet valve 12' comprises an inlet valve disk 13', which is arranged in a valve seat of the second combustion chamber inlet opening 9' when the second combustion chamber inlet opening 9' is to be closed, and an inlet valve stem 14', which extends substantially cylindrically along a second valve axis L12'. The second inlet valve 12' can be moved along the second valve axis L12' by the valve train.

[0040] The injection opening 20' of the injection tube 19' is arranged between a first imaginary plane, which is described by the first valve axis L12 and a perpendicular to the tube core L19', and a second imaginary plane, in which the second valve axis L12' lies and which extends parallel to the first imaginary plane. List of reference symbols 1 internal combustion engine 2 crankcases 3 combustion chamber 4 pistons 5 cylinder head 6 Cylinder head base element 7 Inlet channel 8 Wall 9 Combustion chamber inlet opening 10 exhaust channel 11 Combustion chamber outlet opening 12 Inlet valve 13 Intake valve plate 14 Intake valve stem 15 Exhaust valve 16 exhaust valve plates 17 Exhaust valve stem 18 Injector 19 injection tubes 20 injection opening 21 Top element 22 First connecting section 23 Second connecting section 24 air guidance section 25 Air guidance section 26 Air guidance section 27 Air guidance section L19 tube core L12 valve axis L15 valve axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 0694124 B1

[0003]

Claims

[1] Cylinder head for an internal combustion engine, in particular for a hydrogen-powered internal combustion engine, comprising: a cylinder head assembly having an inlet port (7), an injector (18) connected to the cylinder head assembly, and a tubular injection tube (19) extending along a tube core (L19) into the intake port (7) and fluidly connected to the injector (18), characterized by , that an attachment element (21) is arranged on the injection tube (19), and that the attachment element (21) has an air guiding section (25, 26, 27), which extends radially outwards with respect to the tube core (L19) in such a way that a flow in the inlet channel (7) is influenced by the air guide section (25, 26, 27). [2] Cylinder head according to claim 1, characterized bythat a radial extension of the air guiding section (25, 26, 27) with respect to the tube core (L19) is greater than an axial extension. [3] Cylinder head according to one of claims 1 or 2, characterized by that the attachment element (21) has a first connecting section (22) with which the attachment element (21) is arranged on the injection tube (19), wherein the air guide section (25, 26, 27) extends radially outwards in particular from the first connecting section (22) with respect to the tube core (L19). [4] Cylinder head according to claim 3, characterized by that the smallest cylindrical envelope of the first connecting section (22), the cylinder axis of which is arranged coaxially to the tube core (L19), has a smaller radius than the greatest radial distance of the air guiding section (25, 26, 27) from the tube core (L19). [5] Cylinder head according to one of claims 3 or 4, characterized byin that the attachment element (21) has a second connecting section (23) which is in contact with a wall (8) of the inlet duct (7), wherein the first connecting section (22) and the second connecting section (23) are connected to one another via the air guide section (25, 26, 27). [6] Cylinder head according to one of claims 1 to 5, characterized by that the injection tube (19) has an injection opening (20) which opens into the inlet channel (7), wherein the attachment element (21) is arranged between the injector (18) and the injection opening (20). [7] Cylinder head according to claim 6, characterized byin that the cylinder head (5) comprises a first valve (12) which can open and close a first combustion chamber opening (9) of the inlet channel (7), wherein the first valve (12) has a valve plate (13) and a valve stem (14) which extends along a first valve axis (L12), wherein the injection opening (20) is arranged at least in sections within a smallest cylindrical envelope of the valve plate of the first valve (12), which is coaxial with the first valve axis (L12). [8] Cylinder head according to claim 6, characterized by that the cylinder head (5) comprises a first valve (12) which can open and close a first combustion chamber opening (9) of the intake port (7), wherein the first valve (12) has a valve plate (13) and a valve stem (14) extending along a first valve axis (L12), and that the cylinder head (5) comprises a second valve (12') which can reversibly open and close a second combustion chamber opening (9') of the intake port (7), wherein the second valve (12') has a valve plate (13') and a valve stem (14') extending along a second valve axis (L12'), wherein the injection opening (20) is arranged between a first imaginary plane, which is described by the first valve axis (L12) and a perpendicular to the tube core (L19), and a second imaginary plane, in which the second valve axis (L12') lies and which extends parallel to the first imaginary plane. [9] Cylinder head according to one of claims 1 to 8, characterized by that the air guiding section (25, 26, 27) is designed as an air guiding plate, the extension of which along a circumference around the tube core (L19) is smaller than the radial extension with respect to the tube core (L19). [10] Internal combustion engine comprising: a cylinder head according to claims 1 to 9.

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