Mahle International Gmbh

Mahle Gmbh

Helmut Kollotzek

Wolfgang Issler

Markus Leitl

Josip Zvonkovic

Arnold Benz

Sven Schilling

Ernst Limbach

Thomas Hettich

Frank Ehmann

A soluble and substantially ring-shaped casting core may include a cooling channel in a piston having at least one inflow and at least one outflow. The casting core may form a closed ring and the inflow may be arranged directly adjacent to the outflow. The casting core may have a cross-sectional taper for forming a choke in the circumferential direction between the inflow and the outflow.

Casting core for forming a cooling channel in a piston

The invention relates to a soluble and essentially annular casting core () for forming a cooling channel that transitions into two areas () which are approximately parallel to the piston axis () and are facing away from the piston head (), via a respective bending of the core () in the shape of a quadrant, wherein the second area () transitions into a part of the casting core () that forms the feed opening () of the cooling channel, and the first area () transitions into a part of the casting core () that forms the discharge opening () of the cooling channel. The two areas () of the casting core () are disposed at a distance from one another, which corresponds at a maximum to two times the cross-sectional diameter of one of the two areas (). As a result, the throughflow of the cooling oil traversing the cooling channel is accelerated and the cooling of the piston improved.

Casting core for forming a cooling channel in a piston produced by casting

A soluble casting core for forming a cooling channel in a piston has a formed-on part for forming an oil supply opening and a formed-on part for forming an oil drain opening. In order to improve the mechanical strength of the piston, the oil supply opening and the oil drain opening lie in a different pin boss support of the pin bosses of the piston. A third formed-on part, which lies in the circumferential direction and is configured in oblong manner, is disposed between the first formed-on part and the end of the casting core, which part has a shape that narrows conically towards the end of the casting core and forms a continuation of the cooling channel, which narrows conically towards the end of the cooling channel.

Casting core for forming a cooling channel

A piston for an internal combustion engine has annular cooling passage arranged in the vicinity of the piston crown and radially on the outside, which, in those regions of the pin bosses which lie close to the boss holes, has boss cooling passages which are connected to the cooling passage and are intended for improved cooling of the pin bosses.

Piston for an internal combustion engine and method for its production

A piston for an internal combustion engine has an annular cooling channel provided with oil admission boreholes and oil discharge boreholes, the oil discharge boreholes being oriented in the direction of the bolt hubs for the cooling thereof.

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Mutlangen, Germany

Helmut Kollotzek