A piston for a heavy duty diesel engine including a composite layer forming at least a portion of a combustion surface is provided. The composite layer has a thickness greater than 500 microns and includes a mixture of components typically used to form brake pads, such as a thermoset resin, an insulating component, strengthening fibers, and an impact toughening additive. According to one example, the thermoset resin is a phenolic resin, the insulating component is a ceramic, the strengthening fibers are graphite, and the impact toughening additive is an aramid pulp of fibrillated chopped synthetic fibers. The composite layer also has a thermal conductivity of 0.8 to 5 W/m.Math.K. The body portion of the piston can include an undercut scroll thread to improve mechanical locking of the composite layer. The piston can also include a ceramic insert between the body portion and the composite layer.

A piston for a heavy duty diesel engine including a composite layer forming at least a portion of a combustion surface is provided. The composite layer has a thickness greater than 500 microns and includes a mixture of components typically used to form brake pads, such as a thermoset resin, an insulating component, strengthening fibers, and an impact toughening additive. According to one example, the thermoset resin is a phenolic resin, the insulating component is a ceramic, the strengthening fibers are graphite, and the impact toughening additive is an aramid pulp of fibrillated chopped synthetic fibers. The composite layer also has a thermal conductivity of 0.8 to 5 W/m.Math.K. The body portion of the piston can include an undercut scroll thread to improve mechanical locking of the composite layer. The piston can also include a ceramic insert between the body portion and the composite layer.

Piston (1) of an internal combustion engine, which piston is designed in structured construction, comprising two oppositely arranged load-bearing skirt wall portions (2), wherein a connecting wall (3) respectively extends, starting from a pin boss (4), in the direction of the side edge of the load-bearing skirt wall portions (2), characterized in that in an interior of the piston (1) is (are) disposed at least one rib (5, 6, 7), preferably three ribs (5, 6, 7), and the material of the regions around the at least one rib (5, 6, 7) is reduced.

The present invention relates to a piston (10) for an internal combustion engine, which has a piston skirt (14) as well as a piston head (13) having a circumferential ring belt (21) and having a circumferential cooling channel (24) closed off with a closure element (26), wherein a circumferential recess (23) is formed between the piston head (13) and the piston skirt (14). According to the invention, it is provided that the closure element (26) consists of at least two subcomponents (27, 28), that each subcomponent (27, 28) has a radially oriented base plate (29) and at least one circumferential collar (31) oriented axially on the outer edge (29a) of the base plate (29), which collar is accommodated in at least one outer fold (34) that runs underneath the ring belt (21).

A piston for an internal combustion engine, configured as a gallery-cooled piston of two-piece construction includes a main body and a ring element. The ring element which has a ring zone and a fire land encloses a cooling gallery on the outside, which cooling gallery is delimited on the inside by an intermediate wall which separates the cooling gallery from a combustion chamber recess which is made in a piston head of the main body. The main body and the ring element together form two circumferential dividing planes which are offset with respect to one another, to which end in each case two interacting joining webs of the ring element and of the main body are connected with a material-to-material bond.

The present invention relates to a multi-piece, in particular at least two-piece, piston (1) for an internal combustion engine having a longitudinal axis (L), comprising a piston outer part (10) having a closed piston head (11), which in the fitted state defines a combustion chamber, and a piston body (13) extending axially away from the piston head (11), and a piston inner part (20), which in the fitted state is connected to a connecting rod. An outer surface (2) radially defining the piston (1) is formed exclusively by at least one portion of the piston body (13) of the piston outer part (10). The piston inner part (20), viewed in an axial direction, is arranged radially entirely inside the piston body (13) or its circumferential surface.

A method is provided for designing and producing fiber-reinforced polymer (FRP) pistons. Pistons made with FRP have a lower mass than prior art metal pistons conferring advantageous engine efficiency and stability. FRP pistons also increase the thermal efficiency of engines by having a lower thermal conductivity, with tighter piston-to-bore clearance, and/increased air-fuel ratio than pistons of metal. The technical parameters of the piston are identified, and a piston body blank is produced. The blank is then machined, a bearing surface for the pin bore is created, the piston blank is optionally coated, is optionally subjected to Heavy Metal Ion Implantation (HMII) treatment and is subjected to sodium silicate impregnation to produce the final pistons.

A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The oil gallery channel is first forged to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine-finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original forged condition.

The present invention relates to a method for producing a piston (1) for an internal combustion engine from a piston upper part (2) and a piston lower part (3).

The method has the following method steps: producing a piston upper part (2) having a piston top (6), at least parts of a ring section (12) and at least part (7) of a cooling channel (8), by forging or casting for example, producing the piston lower part (3) and closing the part (7) of the cooling channel (8) which is arranged in the piston upper part (2) by means of an additive method, finish-machining the piston (1), including the production of at least one annular groove (4) in the ring support (5) for receiving a piston ring.

In this way, it is possible to provide a piston (1) that has a greater strength in its piston upper part (2), which is subjected to high thermal and mechanical loads, than in its piston lower part (3), which is subjected to lower thermal and mechanical loads, and that permits greater freedom of manufacture in respect of the shape of the piston lower part (3).

The present disclosure provides a sealing ring assembly with one or more piston-integrated gap cover features, configured to seal a high-pressure region from a relatively lower pressure region of a piston and cylinder device. The sealing ring assembly may include two rings which each may include one or more ring segments. The one or more gap-cover features, which may be in the form of protrusions in the piston ring groove, may engage with corresponding flat sections of the ring segments. As the sealing ring wears, the gap-cover features may stay engaged with the ring segments, thereby maintaining a seal.