Internal combustion engine with cylinder head, and method for producing a cylinder head of an internal combustion engine of said type

Abstract

The application relates to internal combustion engines, cylinder heads, exhaust passages, and shapes and configurations of the exhaust passages. The exhaust passage may have cross-sectional shapes formed by two limbs. The cross-sectional shape of the exhaust passage may change as the passage extends. The exhaust passage may also merge with other exhaust passage. The exhaust passage may be part of a cylinder head or an exhaust manifold.

Claims

1. An internal combustion engine having at least one cylinder head comprising at least one cylinder, in which each cylinder has at least one inlet opening, each inlet opening being adjoined by an intake line for the supply of air via an intake system, each cylinder has at least one outlet opening, each outlet opening being adjoined by an exhaust line for the discharge of exhaust gas via an exhaust-gas discharge system, and at least one exhaust line has a cross-section which changes in a flow direction, wherein the cross-section has an L-shaped outline, wherein the cross-section is arranged within the at least one cylinder head.

2. The internal combustion engine as claimed in claim 1, wherein the cross-section has at least one rounded corner.

3. The internal combustion engine as claimed in claim 1, wherein an edge which delimits the cross-section runs in curving fashion.

4. The internal combustion engine as claimed in claim 1, having at least two exhaust lines, wherein the at least two exhaust lines merge to form one exhaust line within the at least one cylinder head.

5. The internal combustion engine as claimed in claim 1, wherein the cross-section has two limbs which are connected together and form an angle and the angle meets the following criterion at point in the cross-section: 90.

6. The internal combustion engine as claimed in claim 5, wherein the angle meets the following criterion: 90 at a second point in the cross-section.

7. A method for producing a cylinder head of an internal combustion engine as claimed in claim 1, wherein the cylinder head is cast.

8. An internal combustion engine having at least one cylinder head comprising at least one cylinder, in which each cylinder has at least one inlet opening, each inlet opening being adjoined by an intake line for the supply of air via an intake system, each cylinder has at least one outlet opening, each outlet opening being adjoined by an exhaust line for the discharge of exhaust gas via an exhaust-gas discharge system, and at least one exhaust line has a cross-section which changes in a flow direction, wherein the cross-section has an L-shaped outline, wherein an edge which delimits the cross-section runs in undulating fashion.

9. An internal combustion engine having at least one cylinder head comprising at least two cylinders, in which each cylinder has at least one inlet opening, each inlet opening being adjoined by an intake line for the supply of air via an intake system, each cylinder has at least two outlet openings, each outlet opening being adjoined by an exhaust line for the discharge of exhaust gas via an exhaust-gas discharge system, and at least one exhaust line has a cross-section which changes in a flow direction, wherein the cross-section has an L-shaped outline, wherein the at least two exhaust lines of each cylinder first merge into a partial exhaust line before the partial exhaust lines merge into at least one overall exhaust line, and the merging into at least one overall exhaust line occurs within the at least one cylinder head.

10. The internal combustion engine as claimed in claim 9, in which the cross-section has two limbs which are connected together and form an angle , wherein a first upper limb of the cross-section is arranged on a side of the exhaust passage opposite the at least one cylinder.

11. The internal combustion engine as claimed in claim 10, wherein a second side limb of the cross-section is arranged at angle from the first upper limb and extends toward the cylinder.

12. The internal combustion engine as claimed in claim 11, wherein the second side limb tapers towards its free end.

13. The internal combustion engine as claimed in claim 12, wherein the second side limb is narrower and/or shorter than the first upper limb.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The application will be described in more detail below on the basis of exemplary embodiments in accordance with the figures listed below.

(2) FIG. 1A shows diagrammatically, in a perspective view, a state-of-the-art exhaust manifold.

(3) FIG. 1B shows diagrammatically, in a perspective view, the exhaust manifold integrated into the cylinder head of a first embodiment of the internal combustion engine, together with a fragment of a cylinder.

(4) FIG. 2A shows a fragment of the exhaust manifold shown in FIG. 1B with a view onto the underside of the manifold.

(5) FIG. 2B shows the cross-section X-X marked in FIG. 2A.

(6) FIG. 2C shows the cross-section Y-Y marked in FIG. 2A.

(7) FIG. 3 shows further embodiments of exhaust passage cross-sections.

(8) FIG. 4 is a top down view through a cylinder head of an engine with integrated exhaust manifold.

(9) FIG. 5 is a schematic view of an engine featuring a turbocharger.

(10) FIG. 6 is a view of a cylinder and exhaust passage.

(11) FIGS. 1A, 1B, 2A, 2B, 2C, 3, 4, and 6 are shown approximately to scale.

DETAILED DESCRIPTION

(12) FIG. 1A shows diagrammatically, in a perspective view, a state-of-the-art exhaust manifold 4 integrated into the cylinder head of an embodiment of the internal combustion engine, together with a fragment of a cylinder 9.

(13) FIG. 1B shows diagrammatically, in a perspective view, the exhaust manifold 4 integrated into the cylinder head of an embodiment of the internal combustion engine, together with a fragment of a cylinder 9. This embodiment shows an exhaust manifold 4 of a three-cylinder in-line engine which has three cylinders 9, two outer cylinders and one inner cylinder. The manifold 4 is shown from above or the top.

(14) Each of the three cylinders 9 is equipped with two outlet openings 8a, 8b, wherein each outlet opening 8a, 8b is adjoined by an exhaust line 1a, 1b. The exhaust lines 1a, 1b of each cylinder 9 merge to form a partial exhaust line 2 associated with the cylinder 9, wherein the partial exhaust lines 2 in turn merge subsequently, that is to say downstream, to form a common overall exhaust line 3. All the exhaust gas from the cylinders 9 passes through the overall exhaust line 3.

(15) Starting from an outlet opening 8a, 8b of the cylinder 9, the adjoining exhaust line 1a, 1b changes its cross-section in the flow direction.

(16) FIG. 2A shows a fragment of the exhaust manifold 4 shown in FIG. 1B with a view onto the underside of the manifold 4. The cross-section 5a, 5b of each exhaust line 1a, 1b changes in the flow direction, wherein the cross-section 5a, 5b in places has an L-shaped outline such that the overall shape of the cross-section is L-shaped.

(17) Cross-sections X-X and Y-Y are marked in FIG. 2A, which are shown in FIGS. 2B and 2C. Both sections run inclined by an angle 45 relative to the longitudinal axis of the cylinder 9. The longitudinal axis of the cylinder is shown as the z-axis in FIG. 6. An angle of inclination of an exhaust passage can be seen relative to his z-axis.

(18) FIG. 2B shows the section X-X marked in FIG. 2A through the two separate exhaust lines 1a, 1b. The substantially L-shaped cross-sections 5a, 5b are each delimited by an associated edge 6a, 6b which runs in a curving fashion, so that the cross-sections 5a, 5b have rounded corners.

(19) The depicted embodiment cross-section 5a, 5b has two limbs 7a, 7b which are connected together and form an angle . The depicted angle is greater than 90 but the angle will vary with the embodiment and location of the section on the exhaust passage.

(20) An upper limb 7a of each cross-section 5a, 5b is arranged on the top of the exhaust manifold 4, i.e. on the side of the manifold 4 facing away from the cylinder 9 and forming part of the top side of the manifold 4 or toward the top face of a cylinder head. For example, FIG. 6 depicts a z-axis of a cylinder. The upper limb 7a is arranged on a side of the exhaust passage distal from the cylinder in a z-direction. The upper limb 7a may have a planar shape primarily extending in the x and y directions of the cylinder and have a thickness primarily in a z direction of the cylinder. The exhaust passage may also extend at an angle relative to the cylinder.

(21) A side limb 7b of each cross-section 5a, 5b is arranged at an angle from the upper limb 7a. This angle can be used to determine the orientation of the side limb 7b. In some embodiments, the angle is approximately 90 degrees. In this instance, the side limb 7b will extend primarily in a z and y plane and have a thickness in the x direction. The side limb 7b may extend in a similar direction to a vertical side wall of a cylinder head or exhaust manifold 4.

(22) Both the upper and side limbs 7 may taper towards their free ends. Also, the second side limb 7b may be narrower and shorter than the associated first upper limb 7a.

(23) FIG. 2C shows the section Y-Y marked in FIG. 2A through partial exhaust lines 2 belonging to the cylinder. The substantially F-shaped cross-section 5c of the partial exhaust line 2 is delimited by an associated edge 6c which runs in curving fashion, so that the cross-section 5c has rounded corners.

(24) FIG. 2C shows that passages 1a and 1b with substantially L-shape cross-sections 5a and 5b may merge forming a merged passage 11. The merged passage 11 may include attributes of the cross-sections 5a and 5b. For example, the merged passage 11 may include four limbs forming two angles. These four limbs and two angle correspond to the limbs 7a and 7b of FIG. 2B. The angles will be discussed in greater detail in regards to FIG. 3. The cross-section of the merged passaged 11 may have many shapes. In an embodiment of a cross-section with four limbs and two angles as depicted, the two angles may vary, the length of each limbs may vary, the taper of each of the limbs may vary or all of characteristics may vary simultaneously. Merged passages 11 may also change shape such that four limbs are no longer present. In one embodiment the side limbs 7b may shorten until they are no longer present, leaving only two limbs remaining. Many other shapes of the cross-section consistent with this application will be appreciated by one of ordinary skill in the art.

(25) The cross-section of the merged passage 11 may continue to change as the merged passage 11 extends. The merged passage 11 may have a cross-section that becomes more uniform as it extends. A uniform cross-section may be substantially circular, elliptical, square or rectangular. This uniform shape may occur by the shortening of the side limbs 7b and upper limbs 7a.

(26) FIG. 3 depicts further cross-sections of partial exhaust passage 1a. Cross-section 300 is depicted in FIG. 2A as W-W. Cross-section 300 depicts an angle 308 between limbs 312 and 314. The angle depicted in FIG. 3 is greater than 90 degrees but this angle may vary as the passage extends and in other embodiments. As shown in cross-section 304 with angle 310, the angle can be greater than depicted by angle 308. This angle can also be less than 90 degrees or approximately 90 degrees.

(27) Cross-section 300 also depicts the shape of elements of the cross-section. The taper of limb 312 can be seen in cross-section 300. A distal width 318 of limb 312 is less than a more central width 316. This depiction shows that limbs may taper as they extend. However, limbs may have other shapes as well. Limb 314 shows a limb with edges that extend approximately parallel while cross-section 306 show a limb which widens as it extends distally.

(28) Further cross-sections of exhaust passage 1a are depicted in FIG. 3. Cross-section 302 is depicted in FIG. 2A as V-V. Cross-section 304 is depicted in FIG. 2A as U-U. Cross-section 306 is depicted in FIG. 2A as T-T. The cross-sections 300, 302, 304, and 306 depict how the shape of exhaust passage 1a changes as it extends in a flow direction of the exhaust. Initially, the cross-section is non-uniform and round, as depicted in cross-section 306. As the exhaust passage extends, the cross-section becomes more defined and the angle between the limbs decreases as shown in cross-section 300. Then, the cross-section may merge with another passage as shown by merged passage 11, depicted in FIG. 2C. The merged passage 11 may then continue to change shape and merge with other passages before exiting the cylinder head.

(29) FIG. 4 depicts a top down view of an engine. FIG. 4 shows an engine 201 with integrated exhaust manifold 202. FIG. 1 also includes exhaust passages 203 and outlet openings 204. Exhaust gas exits the cylinder through the outlet openings 204. FIG. 4 also depicts the axes that will be used for reference in the present application. The z-axis is oriented longitudinally with the cylinder. The x-axis is oriented perpendicular to the z-axis and extends through the cylinders in multi-cylinder engines. The y-axis is perpendicular to both the x-axis and z-axis and extends away from the cylinder bank in multi-cylinder engines.

(30) Embodiments feature exhaust lines of an engine that merge within the cylinder head, so as to form an integrated exhaust manifold. If the exhaust lines merge within the cylinder head, so as to form an integrated exhaust manifold, the cross-sections according to the application are inevitably arranged within a cylinder head. Other embodiments may also feature conventional exhaust manifolds with exhaust line cross-sections according to the application outside of the cylinder head. These embodiments may feature at least two exhaust lines merging to form an overall exhaust line outside the at least one cylinder head.

(31) FIG. 5 is a schematic view of an engine system. FIG. 5 depicts a cylinder 220 with a piston 221. Exhaust gas exits the cylinder 220 through outlet openings 204 and travels through exhaust passages 203. The exhaust passage 203 is connected to a turbine 222. The turbine 222 is connected to compressor 223 which charges air.

(32) FIG. 6 shows cylinder 320 and exhaust passage 323. Exhaust gas travels through the outlet opening 324 into exhaust passage 323. The axis system described in FIG. 4 is also shown in FIG. 6. FIG. 6 shows an exhaust passage that changes direction relative to all three axes. FIG. 6 depicts a configuration wherein the gas traveling through the passage would initially be traveling in a primarily z direction before bending to travel in a primarily y direction. A further bend would direct the gas into a direction defined by both x and y. This configuration is only one embodiment of the application. Other embodiments could include shapes with shorter traveling distances, less z direction travel, smoother curves, and many other configurations.