ONE-PIECE CAST PISTON FOR AN INTERNAL COMBUSTION ENGINE

Abstract

A one-piece cast piston (10) for an internal combustion engine includes a cooling channel (12) and at least one rib (18) on the inner side of the piston opposite the recess base of a combustion bowl (14).

Claims

1. A one-piece cast piston for an internal combustion engine, comprising a piston body fabricated of a one-piece casting of iron-based material and including, as part of the one-piece casting, a cooling channel, a pair of pin bosses, and at least one rib on the inner side of the piston opposite a recess base of a combustion bowl, wherein when the piston is viewed in the direction of an axis of the pin bosses, the at least one rib extends from an area of at least one of piston pin bosses which is located at a maximum distance from a piston axis, the piston axis is perpendicular to the piston pin axis, and wherein a lowermost limiting of the cooling channel in a direction of the piston axis is located at essentially the same level as a lower groove flank of a lowest piston-ring groove and/or a deepest point of the combustion bowl.

2. The one-piece cast piston for an internal combustion engine according to claim 1, wherein at least one rib extends in a direction of the axis of the pin bosses.

3. The one-piece cast piston for an internal combustion engine according to claim 1, wherein the cooling channel extends in a direction of the piston axis substantially over the whole area of piston-ring grooves.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention is explained in more detail below using a preferred exemplary embodiment.

[0017] The figure shows a section of a piston according to the invention which is perpendicular to the piston pin axis.

DETAILED DESCRIPTION

[0018] As can be seen in the figure, the piston 10 according to the disclosed embodiment has in its upper aea, in the piston axis A1 direction at approximately the same level on the outer face, a ring zone 20 located radially within a preferable closed cooling channel 12 and in the central area a combustion bowl 14. Facing away from the recess base, in a section perpendicular to the piston pin axis A2 in the example shown, there is formed at approximately the deepest part of a ω-shaped combustion bowl a thickening or rib 18 on that side of the recess base which is facing away from the combustion chamber, in other words facing towards the piston pin boss 16. In the example shown, two substantially symmetrical ribs are formed which extend essentially parallel to the piston pin axis A2, that is perpendicular to the drawing plane, towards the side areas of the piston pin boss 16. As can be seen in the figure, the ribs 18 are executed in rounded form on their upper side, which is the underside in the orientation shown. This applies equally for the adjacent areas of the piston underside, so that the respective rib 18, when viewed from the outside to the inside, substantially constitutes a succession of a concave, a convex and a concave curve, which in the example shown transitions into the concave curve of the underside of the combustion bowl 14. It should be mentioned that the described form of the rib 18 can be formed in an advantageous manner when the piston is cast, so that no finishing is required.

[0019] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that the invention may be practiced otherwise than as specifically described while still being within the scope of the invention.