Piston for an Internal Combustion Engine and Method for its Production
AssigneeMahle International GmbH
InventorRainer Scharp
Life of this patent
Estimating the term…
Abstract
Proposed is a piston (1) for an internal combustion engine having a closed annular duct (4) which is arranged close to the piston head (5) and radially at the outside, which annular duct (4) has, at the piston head side, an annular opening (21) which, in section, has the shape of a trapezium with limbs which taper conically in the direction away from the piston head, and which is closed off by an annular closure element (3) which, in section, has the same trapezium shape as the opening (21), with the closure element (3) being fastened in the opening (21) by means of friction welding.
Claims7
Piston (1) for an internal combustion engine
- having a piston crown (5),
- having a ring belt (9) disposed close to the piston crown (5) and on the radial outside of the piston (1),
- having a ring channel (4) disposed close to the piston crown (5) and radially on the outside, which channel has a ring-shaped opening (21) on the piston crown side, which opening has the shape of a trapezoid with sides that run conically towards one another in the direction facing away from the piston crown, in section, whereby the ring channel (4) is connected with the piston interior (18) by way of an oil inflow opening (19) and an oil outflow opening (20),
- having skirt elements (10, 11) that follow the ring belt (9) in the direction away from the piston crown, and lie opposite one another, and
- having pin bosses (14) each having a pin bore (15), which lie opposite one another and are connected with the skirt elements (10, 11),
- wherein the opening (21) is closed off by a ring-shaped closure element (3) that has the same trapezoid shape, in section, as the opening (21), so that the closure element (3) can be attached in the opening (21) by means of a friction-welding method.
Method for the production of a piston (1) for an internal combustion engine, having the following method steps:
- forging a piston blank having a recess for the piston interior (18),
- precision machining the piston blank, using one or more cutting production methods, for the production of pin bores (15), a ring belt (9), and the radially outer surfaces of the skirt elements (10, 11),
- forming a recess that lies in the direction of the piston axis (22), for use as a ring channel (4), having a ring-shaped opening (21) on the piston crown side, proceeding from the piston crown 5, using a cutting production method, whereby the opening (21) has the shape of a trapezoid, in section, having sides that come together conically, in the direction facing away from the piston crown,
- introduction of an oil inflow opening (19) and an oil outflow opening (20) into the ring channel (4), comprising the following method steps:
- production of a ring-shaped closure element (3) that has the same radial diameter and the same cross-sectional shape as the opening (21), and
- attachment of the closure element (3) in the opening (21), using a friction-welding method.
Dependencies are inferred from the claim text.