摘要:
A one-piece piston blank of near-net shape wherein the piston blank has a flange disposed opposite a skirt, the flange being spin-bendable to form a cooling channel with reduced preliminary removal of material relative to conventional forged piston blanks.
摘要:
A galleryless piston for an internal combustion engine and method of construction thereof are provided. The piston has a monolithic piston body extending along a central longitudinal axis. The piston body has an upper wall forming an upper combustion surface with first and second portions, with the first portion extending annularly along an outer periphery of the upper wall and the second portion forming a combustion bowl. The upper wall has an undercrown surface on an underside of the combustion bowl directly opposite the second portion of the upper combustion surface. The undercrown surface has an openly exposed 2-dimensional surface area, as viewed looking along the central longitudinal axis, between about 35-60 percent of an area defined by a maximum outer diameter of the piston body, thereby providing an expansive area against which oil being splashed or sprayed can freely contact to cool the piston.
摘要:
A three section steel piston for two-stroke engines is provided. The piston is provided with an upper section, a middle section and a lower section. Piston ring grooves are formed into the upper and lower sections, and pin bosses with openings and skirts are formed into the middle section. The middle section has relatively thinner walls as compared to the portions of the upper and lower sections at the piston ring grooves to reduce the mass of the piston. A closed cooling gallery may be formed adjacent an upper combustion surface of the piston with the cooling gallery being defined at least partially by the upper section.
摘要:
An opposed-piston engine includes pistons, each piston having an annular cavity in the piston's sidewall and positioned between its crown and ring grooves to block transfer of heat from the crown to the piston body.
摘要:
A peripheral wall portion of a piston is provided with a through hole penetrating through the peripheral wall portion. A cylinder is provided with a scavenging passage having a first opening being open in a bore surface and configured to make a bore section and a crank chamber communicate with each other and is provided with a communication passage having a second opening being open in the bore surface on the other side with respect to the first opening and configured to make the bore section and the scavenging passage communicate with each other. The cylinder and piston are configured so that the through hole overlaps the second opening to communicate with the communication passage in a partial interval of a scavenging stroke in which the first opening becomes open in the bore surface on one side of the piston with reciprocal motion of the piston.
摘要:
A piston for an internal combustion engine may include a piston head and a piston skirt. The piston head may include a piston crown, an encircling fire land, an encircling ring belt having a plurality of ring grooves and an encircling cooling duct disposed radially inwards from the ring belt. The cooling duct may be open in an axial direction away from the fire land and may be at least partially closed via a closure element. The cooling duct may have a cooling duct base and a cooling duct ceiling. The closure element may be arranged on the piston head to define the cooling duct base in a position above a lowermost ring groove of the plurality of ring grooves.
摘要:
A piston assembly and method of construction thereof for an internal combustion engine are provided. The assembly includes a piston head having an upper combustion wall with an undercrown surface and a ring belt region. The piston head has a floor with an upper surface and a bottom surface. The floor is spaced beneath the upper combustion wall in radial alignment with the ring belt region. A substantially enclosed, annular cooling gallery is bounded by the undercrown surface and the floor. A pair of pin bores depends directly from the floor of the cooling gallery. The assembly further includes a pin having ends configured for oscillating receipt in the pin bores. A pin bearing surface extends within the pin bores and between the pin bores in the lower surface of the floor. The assembly includes a connecting rod with an end fixed to the pin for conjoint oscillation therewith.
摘要:
A three section steel piston for two-stroke engines is provided. The piston is provided with an upper section, a middle section and a lower section. Piston ring grooves are formed into the upper and lower sections, and pin bosses with openings and skirts are formed into the middle section. The middle section has relatively thinner walls as compared to the portions of the upper and lower sections at the piston ring grooves to reduce the mass of the piston. A closed cooling gallery may be formed adjacent an upper combustion surface of the piston with the cooling gallery being defined at least partially by the upper section.
摘要:
The invention relates to a piston (10, 110) for an internal combustion engine. Said piston comprises a piston head (11), a piston skirt (12) and a peripheral recess (24) between the piston head (11) and the piston skirt (12), an annular peripheral cooling channel (17), which is open towards the bottom and which is closed by a closing element (18), being provided in the piston head (11), and the piston skirt (12) having fillets (21) which are connected to the bottom of the piston skirt (11) and interconnected via bearing surfaces (23, 123). According to the invention, at least one projection (26, 126) is formed in the region of a free end face (25, 125) of the bearing surfaces (23, 123) and extends radially into a region of the cooling channel (17), said projection matching an opening (19) in the closing element (18) of the cooling channel (17).
摘要:
A method for producing a piston for an internal combustion engine, which piston has at least one cooling channel and is produced from at least one upper part and one lower part. The cooling channel of the piston is formed of the upper part and the lower part where the upper part and the lower part of the piston are each produced by means of a forging process At least one rib-like element, in particular, at least one rib, is additionally forged during the forging of the upper part an area of the cooling channel and/or at least one rib-like element, in particular, at least one rib, is additionally forged during the forging of the lower part in an area of the cooling channel. Two alternative production methods and to a piston for an internal combustion engine are disclosed.