Piston for an internal combustion engine

Abstract

The invention relates to a piston for an internal combustion engine, having shaft wall sections on the pressure and counter-pressure side, and connecting walls between the shaft wall sections. The connecting walls are arched on the counter-pressure side, and the connecting walls are largely straight on the pressure side, such that the counter-pressure side is more elastic that the pressure side.

Claims

1. A piston for an internal combustion engine, having shaft wall sections on pressure and counter-pressure sides of the piston, and connecting walls between the shaft wall sections, the connecting walls on the counter-pressure side being spaced from the connecting walls on the pressure side by pin bosses, the connecting walls being largely straight on the pressure side, the connecting walls on the counter-pressure side being convexly arched from the pin bosses initially over a short section, as viewed from the inside of the piston, and then pass into a concave arching followed by a concave arching of the shaft wall section on the counter-pressure side, such that the counter-pressure side is more elastic than the pressure side, the wall thickness of at least a portion of the shaft wall section and/or at least a portion of the connecting walls being reduced on the counter-pressure side in comparison with the rest of the shaft wall section and/or the rest of the connecting walls, and/or the wall thickness of at least a portion of the shaft wall section and/or at least a portion of the connecting walls being increased on the pressure side in comparison with the rest of the shaft wall section and/or the rest of the connecting walls, and the pin bosses extending outwardly relative to the connecting walls on the pressure and counter-pressure sides.

2. The piston according to claim 1, wherein the shaft wall section on the counter-pressure side is wider, at least in some areas, than the shaft wall section on the pressure side.

3. The piston according to claim 1, wherein one of the connecting walls on the pressure side is axially aligned with one of the connecting walls on the counter-pressure side at the pin boss spacing the connecting walls.

4. The piston according to claim 3, wherein each pin boss is formed by a flange surrounding a pin axis, the flange extends from the axially aligned connecting wall in a direction away from the other pin boss.

5. The piston according to claim 4, wherein the flange extends parallel to the pin axis and does not extend in a direction toward the other pin boss.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the following an exemplary embodiment illustrated in the drawing is described in greater detail.

(2) The FIGURE shows a cross-section through the piston according to the invention in the region of the pin bosses.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

(3) In FIG. 1 a cross-section, i.e. a section perpendicular to the axis of rotation of the piston 10 according to the invention is shown. The pin bosses 12 and the shaft wall sections 14 and 16 with which the piston is supported in the cylinder sleeve can be seen. In the FIGURE, 14 identifies the shaft wall section on the counter-pressure side, and 16 the shaft wall section on the pressure side. As a comparison of the two sides by means of the FIGURE shows, the shaft wall section 16 on the pressure side is somewhat narrower, i.e. as measured substantially in the direction of the piston pin axis A, than the shaft wall section 14 on the counter-pressure side. Moreover, the connecting walls 18 and 20 of the two sides differ. On the pressure side the connecting walls 20 are largely straight in order to support the shaft wall section 16 on the pressure side as rigidly as possible so that the loads can be absorbed. On the other hand, the connecting walls 18 on the counter-pressure side are arched so that a more elastic form is provided here which is advantageous for the piston noises. With the exemplary embodiment shown, the connecting walls 18 on the counter-pressure side are convexly arched from the pin bosses 12 initially over a short section, as viewed from the inside 22 of the piston, and then pass harmonically into a concave arching followed by the concave arching of the shaft wall section 14 on the counter-pressure side. Furthermore, in the exemplary embodiment shown in FIG. 1, one of the connecting walls 20 on the pressure side is axially aligned (relative to the pin axis A) with one of the connecting walls 18 on the counter-pressure side at the pin boss 12 which spaces those two connecting walls 18 and 20. Each pin boss 12 is formed by a flange surrounding the pin axis A, and the flange extends from the axially aligned connecting walls 18 and 20 along the pin axis A in a direction away from the other pin boss 12, but not in a direction toward the other pin boss 12.

(4) With the exemplary embodiment shown all of the connecting walls 18 are formed such that they accommodate the pin bosses 12 on the inside of the latter, i.e. on the side directed towards the piston interior 22. Furthermore, with the exemplary embodiment shown the shaft wall section 16 extends a little beyond the connecting walls 20 on the outside on the pressure side in order to make available a sufficient area in order to support the piston 10.