The present invention refers to a method for controlling a piston cooling circuit of an internal combustion engine wherein said circuit comprises at least a circulation pump and means for emitting cooling oil connected to the delivery of the pump. According to the method, said pistons are cooled by a jet generated by said emitting means only during the upward stroke of said pistons from the bottom dead center to the top dead center.

A structure for attaching an oil jet valve includes a bracket secured to an internal combustion engine with a seal member, an attachment concavity extending through the interior of the bracket, an insertion hole extending through the interior of the internal combustion engine, an oil jet valve, a first stepped part formed in the oil jet valve, a second stepped part formed in the attachment concavity, and an interlocking member. The width of a wide part of the first stepped part is less than the width of a narrow part of the second stepped part. The width of the wide part of the first stepped part is less than the width of a portion, of the inner surface of the attachment concavity, that faces the wide part of the first stepped part.

A structure for attaching an oil jet valve includes a bracket secured to an internal combustion engine with a seal member, an attachment concavity extending through the interior of the bracket, an insertion hole extending through the interior of the internal combustion engine, an oil jet valve, a first stepped part formed in the oil jet valve, a second stepped part formed in the attachment concavity, and an interlocking member. The width of a wide part of the first stepped part is less than the width of a narrow part of the second stepped part. The width of the wide part of the first stepped part is less than the width of a portion, of the inner surface of the attachment concavity, that faces the wide part of the first stepped part.

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.

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.

An engine cylinder block includes a control valve and stratified layers defining a network internal to the cylinder block. The network includes a main feed line in fluid communication with the control valve, and branched and winding arterial channels extending from the main feed line with diameters that taper to define nozzles configured to spray coolant on sides of pistons carried within the cylinder block.

A galleryless piston having a reduced weight and a reduced operating temperature is provided. The piston includes an undercrown surface exposed from an underside of the piston, a ring belt, pin bosses each presenting a pin bore, and skirt panels depending from the ring belt and coupled to the pin bosses by strut. The piston further includes an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels, the struts, and the pin bosses. The piston also includes outer pockets each extending along the undercrown surface and each surrounded by a portion of the ring belt, one of the pin bosses, and the struts coupling the one pin boss to the skirt panels. Cutouts are located in the pin bosses above the pin bores to increase the area of the undercrown surface and thus allow cooling oil to remove more heat from the undercrown surface.

A piston of a cylinder of an internal combustion engine includes: an upper piston crown; a radially outer surface; a plurality grooves arranged on the radially outer surface; and a plurality of piston rings each positioned in a respective one of the grooves. The radially outer surface forms a top land arranged between the upper piston crown and an uppermost one of the grooves of the piston, and the top land has an axial length and a non-abrasion-proof coating.

A piston of a cylinder of an internal combustion engine includes: an upper piston crown; a radially outer surface; a plurality grooves arranged on the radially outer surface; and a plurality of piston rings each positioned in a respective one of the grooves. The radially outer surface forms a top land arranged between the upper piston crown and an uppermost one of the grooves of the piston, and the top land has an axial length and a non-abrasion-proof coating.

Systems and devices are disclosed for controlling fluid flow to piston cooling nozzles with a fluid flow control device configured to open when an internal combustion engine requires piston cooling at high speed but remains open for a period of time after the engine speed drops below a threshold to prevent heat soak damage to the pistons.