INTERNAL COMBUSTION ENGINE INCLUDING AN ELEMENT AT THE CYLINDER INNER WALL FOR SCRAPING OFF OIL CARBON

Abstract

An internal combustion engine of a motor vehicle includes an element at the cylinder inner wall for scraping off oil carbon. The internal combustion engine includes at least one working cylinder and a cylinder head closing the working cylinder, the working cylinder including a cylinder barrel and/or a cylinder liner (1), and which includes at least one element in the area of the cylinder head, which is suitable for scraping off any accumulated oil carbon.

Claims

1. An internal combustion engine comprising: at least one working cylinder; and a cylinder head closing the working cylinder, the working cylinder including a cylinder barrel or a cylinder liner including at least one element in an area of the cylinder head or a top dead center of a corresponding piston of the cylinder barrel or cylinder liner, the at least one element being configured for scraping off any accumulated oil carbon.

2. The internal combustion engine as recited in claim 1, wherein the at least one element is raised in a direction of the corresponding piston.

3. The internal combustion engine as recited in claim 1, wherein the at least one element includes at least one circumferential groove.

4. The internal combustion engine as recited in claim 1, wherein the at least one element includes at least one knurled section.

5. The internal combustion engine as recited in claim 3, wherein the at least one knurled sections is raised at an inner wall of the cylinder barrel or the cylinder liner.

6. The internal combustion engine as recited in claim 1, wherein an inner diameter of the cylinder barrel or the cylinder liner is smaller in the area of the cylinder head or the top dead center of a corresponding piston than in an remaining course of the cylinder barrel or the cylinder liner due to the at least one element.

7. The internal combustion engine as recited in claim 1, wherein the at least one element is made up of at least one circular circumferential groove.

8. The internal combustion engine as recited in claim 1, wherein the at least one element is made up of circumferential grooves situated one above the other in a circular manner.

9. The internal combustion engine as recited in as recited in claim 1, wherein the at least one element is made up of an inner thread.

10. The internal combustion engine as recited in claim 1 wherein the internal combustion engine is a diesel engine of a motor vehicle.

11. A method for operating an internal combustion engine comprising: providing the internal combustion engine as recited in claim 1; and operating the internal combustion engine such that the at least one element scrapes off any accumulated oil carbon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure is explained in greater detail below on the basis of one exemplary embodiment.

[0029] FIG. 1 shows a detail of an internal combustion engine, which shows the knurled section of a cylinder liner and an associated piston;

[0030] FIG. 2 shows a detail of the knurled section, which shows the grooves.

DETAILED DESCRIPTION

[0031] FIG. 1 shows a detail of an internal combustion engine, including a cylinder liner 1, embossed knurled section 7 in the area of the cylinder head-side top dead center position of corresponding piston 2 at its inner wall. Piston 2 includes piston rings 3, a piston crown and fire land zone 5, which extends from the piston crown to first piston ring 3. The narrowing of cylinder liner 1 in the area of the top dead center position of the corresponding piston begins with knurled section 7, as is apparent in detail in FIG. 2. Due to the raised knurled sections, which cylinder liner 1 has on its inner wall, the inner diameter in this area (TDC) is smaller than in the remaining course of the cylinder or cylinder liner 1. As a result, no oil carbon or only oil carbon in a very small quantity or in a very thin layer may accumulate in fire land zone 5, which increases wear and may damage the cylinder liner and the honing in the upward and downward motion of piston 2. Grooves 8 and knurled sections 7 are situated in an inclined manner and have an angle with respect to the cylinder or cylinder liner 1. Knurled section 7 is an integral part of the cylinder or cylinder liner 1 and may be machined out of the preferred material of the cylinder or cylinder liner 1. Methods of non-cutting knurling are also useful to apply knurled section 7 in the cylinder or the cylinder liner.

[0032] FIG. 2 shows an enlarged view of knurled section 7 in the axially parallel section; individual grooves 8 are apparent as integral parts of the cylinder or cylinder liner 1.

LIST OF REFERENCE NUMERALS

[0033] 1 cylinder liner [0034] 2 piston [0035] 3 piston ring [0036] 5 fire land zone [0037] 7 knurled section [0038] 8 groove