PISTON FOR AN INTERNAL COMBUSTION ENGINE

Abstract

A piston (10) for an internal combustion engine includes a groove (16) for an oil wiper ring and a recess (18) between the groove (16) and at least one shaft wall (20). A lower edge of the groove (16), which is closer to the shaft wall (20), has a larger diameter than a lower edge of the recess (18).

Claims

1. A piston for an internal combustion engine, comprising a groove for an oil wiper ring and a recess between the groove and at least one shaft wall, wherein a lower edge of the groove, which is located closer to the shaft wall, has a larger diameter than a lower edge of the recess.

2. The piston according to claim 1, wherein the diameter in the area of the lower edge of the groove is at least 0.08 mm larger than the diameter in the area of the lower edge of the recess.

3. The piston according to claim 1, wherein the upper edge of the recess has essentially the same diameter than the lower edge of the groove.

4. The piston according to claim 1, wherein the recess has an asymmetrically rounded cross-section.

5. The piston according to claim 4, wherein the deepest position of the recess is positioned closer to the upper edge of the recess.

6. The piston according to claim 1, wherein at least one bore is provided which intersects both the lower edge of the groove and the upper edge of the recess.

7. The piston according to claim 6, wherein the at least one bore is configured as a blind hole.

8. The piston according to claim 6, wherein the at least one bore extends at least to the bottom of the groove.

9. The piston according to claim 6, wherein the at least one bore is configured as a through-bore.

10. The piston according to claim 1, wherein that the groove is configured deeper than the recess.

11. The piston according to claim 1, wherein the recess is configured larger in the direction of the piston stroke axis than the groove.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the following, the invention will be described in more detail by means of one embodiment which is shown as an example. The drawings show the following:

[0020] FIG. 1 a partial section through the piston according to the invention; and

[0021] FIG. 2 a perspective view of a part of the piston according to the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0022] As can be seen in FIG. 1, the piston 10 according to the invention comprises a ring zone 12 with two compression ring grooves 14 and a groove 16 for an oil wiper ring which is not shown. Below, i.e. located further away from the piston crown (in the figure above), a recess 18 is provided that is less spaced from the groove 16 in the direction of the piston stroke axis than the groove 16 from the lowest compression ring groove 14. Moreover, the recess is configured less deep than the groove 16 for the oil wiper ring. In particular, it seems sufficient if the recess 18 has less than half the depth of the groove 16. However, it is preferred that the recess 18 has a larger dimension in the direction of the piston stroke axis than the groove 16 for the oil wiper ring.

[0023] In the case shown, the recess 18 has in cross-section the shape of a rounded notch, with the deepest point being located closer to the groove 16. As can be seen, in principle, in the figure, the diameter in the area of the lower edge of the groove 18 is configured smaller than the diameter at the lower edge of the groove 16 in order to achieve here the largest possible support surface for the oil wiper ring.

[0024] In the case shown in FIG. 2, two bores 22 can be seen which serve as oil drainages and intersect both the lower edge of the groove 16 and the upper edge of the recess 18. In addition, in the case shown, the bores extend to the bottom of the groove which is configured deeper than the recess 18, and therefore an oil flow from the groove 16 to the recess 18 can be ensured. In the direction of the piston stroke axis, the bores 22 typically extend from the bottom of the groove 16 to the course of the recess 18.