Double-link piston crank mechanism for internal combustion engine
AssigneeNissan Motor Co., Ltd.
InventorsTakashi Tanabe, Katsuya Moteki
Life of this patent
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Abstract
A multi-link piston crank mechanism includes a crank pin bearing portion including a crank pin bearing central portion that is disposed at a center thereof in an axial direction of a crank shaft. The crank pin bearing central portion at a portion positioned on the first end side of the lower link is thicker in a radial direction of the crank pin than a portion positioned on the second end side of the lower link. The second control link end portion is thicker along a radial direction of the second through hole than the second upper link end portion along a radial direction of the first through hole.
Claims8
A multi-link piston crank mechanism for an internal combustion engine, comprising:
- a lower link comprising a crank pin bearing portion rotatably mounted to a crank pin of a crank shaft;
- an upper link comprising a first upper link end portion connected to a piston pin of a piston, and a second upper link end portion connected to a first end side of the lower link through a first link pin inserted into a first through hole of the second upper link end portion;
- and
- a control link comprising a first control link end portion supported by a cylinder block, and a second control link end portion connected to a second end side of the lower link through a second link pin inserted into a second through hole of the second control link end portion,
- wherein the second end side of the lower link is configured to have an input load due to a combustion load acted thereon,
- wherein the lower link comprises a first bifurcated end side protruding piece portion and a second bifurcated end side protruding piece portion which are positioned on both sides of the crank pin bearing portion when viewed from an axial direction of the crank shaft,
- wherein the first bifurcated end side protruding piece portion sandwiches the second upper link end portion,
- wherein the second bifurcated end side protruding piece portion sandwiches the second control link end portion,
- wherein the crank pin bearing portion comprises a crank pin bearing central portion disposed at a center thereof in the axial direction of the crank shaft,
- wherein the crank pin bearing central portion at a portion positioned on the first end side of the lower link is thicker in a radial direction of the crank pin than a portion positioned on the second end side of the lower link, and
- wherein the second control link end portion is thicker along a radial direction of the second through hole than the second upper link end portion along a radial direction of the first through hole.
Dependencies are inferred from the claim text.