Abstract:
A method for manufacturing a raceway member, in which a hardness of a region to be plastically deformed is controllable in a stable manner and a sufficient rolling contact fatigue life is ensured by making a hardness of a region including a raceway surface sufficiently high, while suppressing increase in the manufacturing cost, includes a steel member preparation step, a heat treatment step, and a finishing step. The heat treatment step includes: a carbonitriding step, in which the steel member is heated to a carbonitriding temperature, which is a temperature not lower than A1 point, and carbonitrided; a temperature holding step, in which the steel member is cooled from the carbonitriding temperature to a temperature range between not lower than a temperature 100° C. below A1 point and lower than A1 point and is held in the temperature range for not less than 60 minutes and not more than 180 minutes; and a induction hardening step, in which the high hardness region in the steel member including a region to become a raceway surface of the raceway member is induction hardened, without quench hardening of a low hardness region which is a region other than the high hardness region.
Abstract:
A rolling bearing for a rocker arm includes an outer ring in rolling contact with a cam of an engine, an outer-ring shaft placed inside the outer ring and fixed to the rocker arm, and a plurality of rollers provided between the outer ring and the outer-ring shaft. At least one of the outer ring, the outer-ring shaft and the rolling elements has a nitrogen-rich layer, an austenite crystal grain size number in a range exceeding 10, and a surface hardness Hv of at least 653. Thus, the life can be extended.
Abstract:
The invention relates to an electromotive device for operating gas exchange valves on internal combustion engines, comprising a rotary actuator exerting forces on one or more valve stem ends of one or more gas exchange valves by means of a lever arrangement. The rotary actuator is a reluctance motor with a cylindrical iron rotor with permanent magnet segments of alternating magnetisation arranged on the circumference thereof. The average angular separation of the poles of the stator of the reluctance motor are approximately equal to the average angular separation of the permanent magnet segments on the rotor. The valve shaft ends operated by the lever arrangement preferably belong to gas exchange valves of a cylinder of an internal combustion engine the opening times of which do not coincide or belong to gas exchange valves on different cylinders. The reluctance motor preferably has a single-phase design. The device permits a valve clearance adjustment of the gas exchange valves by control of the actuator current and carrying out part lifts. The electromotive device for operating gas exchange valves is space-saving, low in energy consumption and wear and self-retaining in certain working positions.
Abstract:
A valve lash measurement device is provided for an internal combustion engine having an articulated valve train including a rocker arm having a bore at one end that receives a valve abutting shoe having an uneven surface. A fixed geometry reference surface is attached to a spring loaded base insertable into the bore. A weight connected to an arm and hook with a fulcrum in between is movable along a reference plate to pivot the rocker arm between its extremes of movement. A dial indicator abuts the reference surface and indicates the relative displacement between the extremes of movement and therefore the lash.
Abstract:
The present invention relates to a lash adjuster including a ball retainer having a generally conical chamber for situating a ball near the base of the lash adjuster housing. The chamber has both an external and internal shoulder for engaging a plunger spring and a ball spring, respectively. The chamber may further define at least one aperture near its apex and at least one aperture near its base to facilitate oil flow through the lash adjuster.
Abstract:
In an internal combustion engine includes an intake valve port that opens into a combustion chamber on one side of a plane containing the axis of a cylinder bore. An exhaust valve port opens into the combustion chamber on the other side of the plane. A spark plug has a tip end that fronts a substantially central portion of the combustion chamber. The spark plug is disposed between the intake valve and the exhaust valve. In order to restrain the blow-by of an unburned fuel-air mixture, and to suppress the bulging of the cylinder head to the intake system side, the operation axis of an intake valve is set to be substantially parallel to the axis of the cylinder bore. In addition, one side surface of a cylinder head is formed to be substantially parallel to the axis of the cylinder bore.
Abstract:
The invention allows for a larger bronze axle outer diameter for increased contact area to carry system loads in tappet body assemblies of engine valve trains; thereby, improving wear and improving the life of the tappet. Relatively small diameter steel pins are used to secure the bronze axle and because the pins are within the bronze axle they do not need to be specifically processed for stress contact or retention. The bronze axle requires the cam roller follower inside diameter to increase as well to reduce the cross section of the cam roller follower. This thinner cross section improves the rotational inertia reducing the risk of skidding at the cam-to-roller interface. Skidding at this interface significantly reduces the life of the cam roller follower and/or the cam lobe. The smaller pin diameter provides addition clearance when packaged next to an adjacent cam lobe.
Abstract:
An automatic tappet clearance adjuster comprising a unit for adjusting the projection by advancing/retracting an adjust screw from the forward end of a rocker arm, a section for detecting the torque by rotating the adjust screw, and a control mechanism section for controlling the adjusting unit according to the torque value measured by the torque detecting section. The control mechanism section measures the torque value continuously when a valve is closed by retracting the adjust screw from the open state of the valve. A rotation reference position corresponding to the intersection of a first approximation line and a second approximation line approximating the sections immediately before and after the inflection point of differential value of the torque value is detected as a reference point, and the adjust screw is retracted by a set amount from the reference point.
Abstract:
A valve control mechanism is provided for an overhead valve, internal combustion engine having a camshaft moving a pushrod to move a rocker arm that in turn moves the valve. Three aligned rollers are fastened to the end of the pushrod adjacent the rocker arm. The outer two rollers roll along parallel profiled surfaces that control at least the valve lift and ramp. The middle roller rolls along an engaging surface on the rocker to move the rocker arm in a motion determined by the configuration and location of the profiled surfaces and the engaging first and second rollers. The outer rollers rotate in a direction opposite the middle roller.
Abstract:
A valve system lifter for combustion engines includes a hard metal face pad connected to a lower-grade metal lifter body. The connecting material is one or more materials that are different from both the lifter body and the face pad. Preferably, the connecting material is a silver-and copper-containing material, that may take the form of a wafer with silver or silver alloy layered over a copper alloy core. The preferred body includes one or more ferrous compounds, and the preferred face includes tungsten carbide. The resulting lifter is resistant to the cracking, breakage, and wear that plague conventional lifters, due to the harsh temperature and impact environment of the lifter. The resulting lifter may be used to reduce the need for change-out and down-time in many engines.