Openwork variable valve timing with a locking device for a camshaft phase shifter of an internal combustion engine.

摘要

A variable timing system camshaft, comprising: a rotatable cam (36); a pallet (20) having at least one lobe (22, 24 or 26) fixed to the camshaft for rotation therewith, said blade not being oscillatable with respect to the camshaft; an annular housing (28) surrounding the vane and having at least one recess (30, 32 or 34), having at least one recess a circumferential extent greater than the circumferential extent of at least one lobe and receiving at least one lobe, said annular housing being rotatable with said camshaft and being oscillatable said blade and with respect to said camshaft and said vane; means driven with oil pressure motor (56, 58, 68) for causing relative circumferential motion between said housing and said vane; and means reactive to engine oil pressure for preventing relative circumferential movement between the housing and said blade said lock; characterized in that said annular housing comprises a first series of teeth (76), and said locking means comprise a locking plate ring (50) having a second series of annular teeth (74), wherein in a first position of said plate lock (50) relative to said annular housing (28), said second annular array of teeth (74) engaging said first annular array of teeth (76) at one end of a plurality of circumferential positions relative to said housing (28 ) and said blade, engaging each tooth of said first annular array with a recess between neighboring teeth of the second annular array and each recess of said second series by an annular tooth of said first annular array, thereby preventing movement being coupled circumferential relative between said carcass (28) and said pallet (20), and in a second position of said locking plate (5) relative to said annular housing, said second annular series of teeth (74) is disengaged from said first annular array of teeth to allow relative circumferential movement between said annular housing and said vane (20); and that there are provided elastic means (52) which deflect said annular locking plate to said first position during periods of low engine oil pressure.