Engine decompression mechanism
AssigneeYamaha Motor Co., Ltd.
InventorsToshikazu Sugiura, Yuki Sagawa
Life of this patent
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Abstract
An engine features a decompression mechanism that extends through a bore formed in a camshaft. The mechanism has an actuator that is formed of multiple shafts. The shafts are joined in the region of a decompression pin. The actuator rotates relative to the camshaft and the rotation drives translation of decompression pins in a radial direction of the camshaft.
Claims19
An engine with a decompression mechanism, the engine comprising a generally hollow camshaft, said camshaft comprising an inner wall that defines a bore, an actuator positioned within said bore, said actuator comprising at least two actuator portions that are rotatable within said bore of said camshaft, said at least two actuator portions being joined end to end at a coupling location, a protrusion extending axially outward of a first end of each of said at least two actuator portions, each said protrusion being radially offset from a rotational axis of said corresponding actuator portion, a driving unit mechanically coupled to said actuator and adapted to rotate said actuator relative to said camshaft, at least two pin holes extending at least partway through said camshaft, said pin holes being positioned proximate said coupling location of said actuator and extending transversely across said camshaft, a pin positioned in each of said at least two pin holes, said pins being adapted to open a valve, said pins comprising an axial direction and being moveable in said axial direction relative to said camshaft, said pins further comprising a recessed portion positioned within said bore of said camshaft, each of said protruding portions of said at least two actuator portions being positioned within a corresponding one of said recesses of said pins such that said recess and said protrusion define a cam mechanism that converts rotational movement of said actuator to translating movement of said pins.
An engine comprising a decompression mechanism, the engine comprising a camshaft, said camshaft being generally hollow and having an inner wall that defines a bore that extends in an axial direction of said camshaft, a first cross hole and a second cross hole extending in a radial direction of said camshaft, said camshaft also comprising a first cam lobe and a second cam lobe, an actuator extending within said bore, said actuator comprising a first portion and a second portion, said first portion having a first portion first end and a first portion second end, said second portion having a second portion first end and a second portion second end, said first portion second end being mechanically coupled to said second portion first end, a first pin being positioned within said first cross hole and being positioned between said first portion second end and said second portion first end, and said first pin being mechanically coupled to at least one of said first portion or said second portion.
An engine comprising a decompression mechanism, the engine comprising a camshaft, said camshaft being generally hollow and having an inner wall that defines a bore that extends in an axial direction of said camshaft, a first cross hole and a second cross hole extending in a radial direction of said camshaft, a first pin positioned within said cross hole and adapted for movement in and out of said first cross hole, a second pin positioned within said cross hole and adapted for movement in and out of said second cross hole, said camshaft also comprising a first cam lobe and a second cam lobe, said first and second pin being positioned respectively adjacent to said first and second cam lobes, an actuator extending within said bore and capable of rotational movement relative to said camshaft, and means for transforming rotation of said actuator relative to said camshaft into bidirectional translation of said first and second pins such that relative rotation in a first direction drives translation in a first direction and relative rotation in a second direction drives translation in a second direction.
Dependencies are inferred from the claim text.