Abstract:
A valve timing control system for varying a valve timing determines whether an engine operating condition falls within a specific valve timing range established for a specific valve timing or a standard valve timing range, other than the specific valve timing range, established for a standard valve timing. A valve timing device is activated so as to change a valve timing to the standard valve timing when the engine operates in the standard valve timing range. The valve timing device is also deactivated so as to change a valve timing to the specific valve timing when the engine operates in the specific valve timing range.
Abstract:
A rotational phase difference adjusting device for adjusting a rotational phase difference between a first rotational member and a second rotational member, comprises, an input member connected to the first rotational member to be rotated thereby, an output member arranged coaxially with the input member and connected to the second rotational member to rotate it, a differential device for connecting the input member to the output member to be rotated thereby and for generating a difference in rotation between the input member and the output member, and a damping device including a viscous fluid which is arranged between the input member and the output member so that a vibration of a relative movement between the input member and the output member is absorbed by a viscosity of the viscous fluid, and including a sealing device for holding the viscous fluid between the input member and the output member against a slide movement of the sealing device between the input member and the output member, wherein the slide movement of the sealing means is carried out on a plane extending substantially perpendicularly to the axis of the input and output members.
Abstract:
Several embodiments of variable camshaft timing means for twin overhead cam engines. There is provided a first timing altering means between the engine output shaft and one of the camshafts and a second timing altering means that is operative between the one camshaft and the other camshaft. Both timing altering means are operated by the same hydraulic pressure in several embodiments and a locking device is incorporated so as to avoid self-induced timing adjustment due to the change in driving loads.
Abstract:
A valve driving mechanism for a double overhead camshaft engine includes a camshaft drive mechanism, including a camshaft sprocket for transmitting engine output from a crankshaft of the engine to one of intake and exhaust camshafts. A valve timing varying mechanism is driven so as to vary a valve timing of, for example, a set of intake valves relative to a valve timing of a set of exhaust valves. The valve timing varying mechanism includes a first helical gear, mounted on the exhaust camshaft for rotation, a second helical gear, in mesh with the first helical gear, which is rigidly secured to the intake camshaft, and a cylindrical sliding element, mounted on the exhaust camshaft for axial displacement. The cylindrical sliding element operationally couples the exhaust camshaft to the camshaft drive mechanism so as to cause a relative rotational displacement therebetween when the cylindrical sliding element undergoes axial displacement with respect to the exhaust camshaft.
Abstract:
A combination bearing and apparatus for maintaining the relative axial location of the input and output members of a camshaft phase change device. Peripheral grooves are formed in the members to receive a plurality of balls which support the input member for rotation on the output member. Radial slots are formed in the output member for insertion of the balls, and the angular position of the balls is maintained by fingers formed on a retention member which has spoke members received in the slots, and which is held in engagement with the output member by a retaining ring.
Abstract:
A valve-controlled internal combustion engine has an device 13 for adjusting the camshaft 2 relative to its timing gear 14. The adjusting device has an operating sleeve, which is interlocked over different gear systems, on the one hand, with the timing gear and, on the other, with the camshaft, and a hydraulic adjusting piston, which can be acted upon on both sides. Pressure is caused to act upon the adjusting piston by means of the engine oil, which is circulating under pressure and which is branched off before a restrictor 11 in the inflow to the bearings 12 in the cylinder head 2 of the internal combustion engine. By these means, the full pressure of the lubricating pump 7 can be used to shift the operating sleeve.
Abstract:
A phase adjustment mechanism for setting the phase of the engine camshaft relative to that of the crankshaft. The operative coupling of the crankshaft to the camshaft is via two sets of splines, one set having pitch different from that of the other set. A spline engagement ring contains a spline of one set on its O.D. and a spline of the other set on its I.D. The axial positioning of the ring controls the relative phasing and is accomplished by a screw and nut mechanism with the nut being operated by a worm drive that is under the control of the engine ECU.
Abstract:
The proposed device comprises a cylinder rigid with a camshaft drive pulley, and a piston restrained to said cylinder and camshaft by helical groove connections and prismatic pair connections which, on command, allow said camshaft to undergo rotation relative to said pulley.
Abstract:
A valve timing control device includes a rotatable shaft, a housing including a timing wheel axially immovable but angularly movable with respect to the timing wheel, a piston disposed coaxially with the rotatable shaft and the timing wheel, a hydraulic chamber for applying a hydraulic pressure to move the piston axially, a servovalve disposed between the hydraulic pressure chamber and hydraulic pressure supply and release passages and comprising a sleeve and a spool, an actuator for axially moving the spool, and a phase adjusting mechanism operatively coupling the piston, the housing, and the rotatable shaft for varying angular relationship between the timing wheel and the rotatable shaft in response to axial movement of the piston. The actuator may be a hydraulic actuator or an electric actuator. The phase adjusting mechanism may comprise roller pins mounted on the piston and rollingly fitted in a guide groove defined in the rotatable shaft and a guide slot defined in the housing, or meshing helical teeth on the piston, the housing, and the rotatable shaft.
Abstract:
This invention relates to a device for automatically varying the timing of a camshaft relative to the drive shaft of an internal combustion engine, comprising an axially slidable splined sleeve which connects the camshaft to its drive pulley, and is operated by the engine lubricating oil in such a manner as to change the angular position of said camshaft by way of valve means controlled by an electromagnetic actuator as a function of at least one engine parameter.