A steel piston (1) for a combustion engine, having an upper part in which a ring section (7) with at least one ring groove (8) is arranged, wherein the upper part is adjoined by a lower part that has two opposing skirt wall sections (2), wherein the two skirt wall sections (2) are connected via two mutually opposite case walls (3), wherein a pin bore (4) surrounded by a piston boss (6) is provided in each case wall (3). In one example, there is at least one aperture (14) or at least one recess in the case wall (3) in the region between the piston boss (6) and the skirt wall section (2).

The present invention relates to pistons (10) for use in internal combustion engines, having: a piston crown (12) which is adjoined by a piston skirt (14), wherein the piston skirt (14) has surfaces (18) which abut the cylinder wall during use of the piston, wherein the surfaces (16) have one or more friction-reducing coatings (18) and wherein depressions (20) are provided in the coating, which are arranged such that the spacing S between each two adjacent depressions (20) along the axial direction (A) of the piston and the width L of the depressions (20) along the axial direction (A) of the piston satisfy the formula S>2L.

A sliding component for an internal combustion engine includes: a sliding component main body that includes a plurality of concave portions formed in a predetermined portion thereof; and a coating layer that covers a portion of the sliding component main body, in which the plurality of concave portions are not formed.

A piston in which a solid lubricant resin layer made of a resin containing a solid lubricant is formed at a skirt portion. A guide groove absent area where no guide groove is formed, which is provided in a predetermined range of the solid lubricant resin layer at a center portion in a width direction. The guide grooves directing from the both ends in the width direction of the guide groove absent area to both ends in the width direction of the skirt portion. The end portions of the guide grooves extended to end edges of the solid lubricant resin layer to form open ends. The solid lubricant resin layer and the guide grooves are formed at least at a thrust side skirt portion. The guide grooves are formed in a shape inclined upward from the guide groove absent area toward the end edges of the solid lubricant resin layer.

A piston for an internal combustion engine has a plurality of recesses formed in a skirt including an upper, a lower, and a central portion. The recesses in the upper portion close to an upper boundary of the central portion have lower ends located upwardly at a given distance away from the upper boundary. The recesses in the central portion close to the upper boundary have upper ends located downwardly at the given distance away from the upper boundary. The recesses in the lower portion close to the lower boundary have upper ends located downwardly at the given distance away from the lower boundary. The recesses in the central portion closer to the lower boundary have lower ends located upwardly at the given distance away from the lower boundary. This enhances lubrication between the piston and an inner wall of a cylinder bore and reduces a friction loss of the piston.

[Problem to be Solved] A space from a skirt to a side wall is uniformly deformed in a wide range without a bias. [Solution] A piston 1 has two pin bosses 3 disposed so as to face each other at an interval, a side wall 4 disposed on both sides of the pin boss 3, and a skirt 5 provided continuously to the side wall 4, and a pin hole 3a into which a piston pin 1a can be inserted is formed in the pin boss 3. Inner walls 10 of the side wall 4 and the skirt 5 are continuous with each other and disposed by facing on both sides of a pin boss axis C1 with the pin boss axis C1 between them. A horizontal section of the inner wall 10 is formed along a specific oval shape E.

A steel piston (1) for a combustion engine, having an upper part in which a ring section (7) with at least one ring groove (8) is arranged, wherein the upper part is adjoined by a lower part that has two opposing skirt wall sections (2), wherein the two skirt wall sections (2) are connected via two mutually opposite case walls (3), wherein a pin bore (4) surrounded by a piston boss (6) is provided in each case wall (3). In one example, there is at least one aperture (14) or at least one recess in the case wall (3) in the region between the piston boss (6) and the skirt wall section (2).

The present invention provides a piston of an internal combustion engine capable of reducing a deformation amount of a piston head. A piston of an internal combustion engine includes a piston head, a pair of piston pin boss portions, a pair of skirt portions, and four apron portions connecting each of the pair of piston pin boss portions and each of the pair of skirt portions. Each of the four apron portions includes a bent portion, a boss portion-side portion positioned on one side where the pair of piston pin boss portions is located with respect to the bent portion, and a skirt portion-side portion positioned on an opposite side from the pair of piston pin boss portions with respect to the bent portion. A distance between an axis perpendicular to both an axis of a cylinder of the internal combustion engine and an axis of a piston hole and the boss portion-side portion is increasing according to an increase in a distance from the axis of the piston pin hole.

[Problem to be Solved] A space from a skirt to a side wall is uniformly deformed in a wide range without a bias.

[Solution] A piston 1 has two pin bosses 3 disposed so as to face each other at an interval, a side wall 4 disposed on both sides of the pin boss 3, and a skirt 5 provided continuously to the side wall 4, and a pin hole 3a into which a piston pin 1a can be inserted is formed in the pin boss 3. Inner walls 10 of the side wall 4 and the skirt 5 are continuous with each other and disposed by facing on both sides of a pin boss axis C1 with the pin boss axis C1 between them. A horizontal section of the inner wall 10 is formed along a specific oval shape E.

A piston for an internal combustion engine has a plurality of recesses formed in a skirt including an upper, a lower, and a central portion. The recesses in the upper portion close to an upper boundary of the central portion have lower ends located upwardly at a given distance away from the upper boundary. The recesses in the central portion close to the upper boundary have upper ends located downwardly at the given distance away from the upper boundary. The recesses in the lower portion close to the lower boundary have upper ends located downwardly at the given distance away from the lower boundary. The recesses in the central portion closer to the lower boundary have lower ends located upwardly at the given distance away from the lower boundary. This enhances lubrication between the piston and an inner wall of a cylinder bore and reduces a friction loss of the piston.