Two-part piston for an internal combustion engine
First Claim
1. Two-part piston (1, 1″
- ) for an internal combustion engine,having an upper part (2, 2″
) that forms a piston crown (4, 4′
),whereby a cylindrical pin (31) having an outside thread (32) and lying coaxial to the piston axis (12) is formed onto the underside of the upper part (2, 2″
), on the side facing away from the piston crown (4, 4″
), andhaving a lower part (3, 3″
), on the underside of which pin bosses (9, 9′
) having pin bores (10, 10′
) and skirt elements (13) that connected the pin bosses (9, 9′
) with one another are disposed,whereby the lower part (3, 3′
, 3″
) has an upper crown part (25, 25′
) with an opening (27, 27′
) that lies coaxial to the piston axis (12), into which opening the pin (31) is introduced, by way of which pin the upper part (2, 2″
) is screwed to the lower part (3, 3″
) by means of a hexagonal nut (29) screwed onto the pin (31),whereinthe radial inside of the opening (27) has a ring-shaped surface (21) disposed on the skirt side, which lies further removed from the piston crown (4) than the upper face surface (23) of the hexagonal nut (29), andthat an expansion sleeve (26) is disposed between the face surface (23) and the surface (21), which sleeve, for one thing, has a collar (28) directed radially inward, disposed on its side facing the piston crown, this collar having a radially oriented inside surface (20) on its side facing away from the piston crown, against which surface the face surface (23) of the hexagonal nut (29) rests, and, for another thing, has a contact surface (19) that faces the piston crown in its region that faces away from the piston crown, which surface rests against the surface (21).
1 Assignment
0 Petitions
Accused Products
Abstract
A two-piece piston for an internal combustion engine has an upper piece and a lower piece, the lower piece having an upper base part with an opening lying coaxial to the piston axis into which a pin on the upper piece is inserted. The upper piece is connected to the lower piece with a hexagonal nut screwed onto the pin. A resilient sleeve is arranged between the upper piece and the lower piece comprising an inwardly directed collar on the against which the upper face of the hexagonal nut lies and in the region facing away from the piston crown, a contact surface facing the piston crown lying on a surface on the inner side of the opening. An economically produced two-piece piston results with a resilient sleeve between both screwed piston pieces which exerts a pre-tensioning and thus provides security for the screw connection.
16 Citations
7 Claims
-
1. Two-part piston (1, 1″
- ) for an internal combustion engine,
having an upper part (2, 2″
) that forms a piston crown (4, 4′
),whereby a cylindrical pin (31) having an outside thread (32) and lying coaxial to the piston axis (12) is formed onto the underside of the upper part (2, 2″
), on the side facing away from the piston crown (4, 4″
), andhaving a lower part (3, 3″
), on the underside of which pin bosses (9, 9′
) having pin bores (10, 10′
) and skirt elements (13) that connected the pin bosses (9, 9′
) with one another are disposed,whereby the lower part (3, 3′
, 3″
) has an upper crown part (25, 25′
) with an opening (27, 27′
) that lies coaxial to the piston axis (12), into which opening the pin (31) is introduced, by way of which pin the upper part (2, 2″
) is screwed to the lower part (3, 3″
) by means of a hexagonal nut (29) screwed onto the pin (31),wherein the radial inside of the opening (27) has a ring-shaped surface (21) disposed on the skirt side, which lies further removed from the piston crown (4) than the upper face surface (23) of the hexagonal nut (29), and that an expansion sleeve (26) is disposed between the face surface (23) and the surface (21), which sleeve, for one thing, has a collar (28) directed radially inward, disposed on its side facing the piston crown, this collar having a radially oriented inside surface (20) on its side facing away from the piston crown, against which surface the face surface (23) of the hexagonal nut (29) rests, and, for another thing, has a contact surface (19) that faces the piston crown in its region that faces away from the piston crown, which surface rests against the surface (21). - View Dependent Claims (2, 3, 4, 5, 6, 7)
whereby the piston (1, 1″
) has a ring-shaped, inner cooling channel (24), within the outer cooling channel (22), disposed coaxial to the piston axis (12), delimited radially on the inside by the pin (31), which channel is connected with the outer cooling channel (22) by way of at least one overflow channel (37, 37′
), andwhereby a ring-shaped gap (33) is situated between the collar (28) of the expansion sleeve (26, 26″
) and the pin (31),wherein the hexagonal nut (29) has at least one radially disposed groove (34, 34′
, 34″
, 34′
″
) in its upper face surface (23), which groove opens radially on the inside, into the gap (33),that an interstice (35) is situated between the hexagonal nut (29) and the expansion sleeve (26, 26″
), the end of which interstice, on the piston crown side, stands in connection with the at least one groove (34, 34′
, 34″
, 34′
″
),that the end of the interstice (35) facing away from the piston crown opens into the piston interior (36), and that a continuous oil channel occurs, proceeding from the oil feed channel (52), by way of the outer cooling channel (22), by way of the at least one overflow channel (37, 37′
), by way of the inner cooling channel (24), by way of the gap (33) between the collar (28) and the pin (31), by way of the at least one groove (34, 34′
, 34″
, 34′
″
) in the face surface (23) of the hexagonal nut (29), and by way of the interstice (35) between the hexagonal nut (29) and the pin (31).
- ) for an internal combustion engine,
-
6. Piston according to claim 5, wherein the hexagonal nut (29) has four radially disposed grooves (34, 34′
- , 34″
, 34′
″
) distributed uniformly over its circumference, on its upper face surface (23).
- , 34″
-
7. Piston according to claim 1, wherein a collar (44) directed radially outward is disposed on the end of the expansion sleeve (26″
- ) facing away from the piston crown, which collar has a radially oriented contact surface (19′
) on the piston crown side, and that a cantilever (45) that narrows conically radially inward in the direction facing away from the piston crown and is elastically resilient is formed onto the inside wall of the opening (27′
), which cantilever has a radially oriented surface (21′
) on its side facing away from the piston crown, against which surface the contact surface (19′
) rests.
- ) facing away from the piston crown, which collar has a radially oriented contact surface (19′
Specification