In a tappet with a built-in lash adjuster, hydraulic oil is prevented from leaking from a low pressure chamber during a long-period stop.

A tappet (10) includes a hydraulic lash adjuster (11) which supports a lower end portion of a push rod (96) and a tappet case (12) to which the lash adjuster (11) is internally fitted and which is reciprocally displaced in a vertical direction according to a rotating cam (85). An inner peripheral surface of the tappet case (12) is provided with an air-vent passage (34) through which air existing between the tappet case (12) and the lash adjuster (11) can be discharged upward when the lash adjuster (11) is being assembled.

A hydraulic lash adjuster includes a longitudinally extending pushrod having a proximal end and a distal end, and a cavity located at the distal end and a piston received in the cavity. The piston includes an internal reservoir and a fluid pathway to the internal reservoir. The fluid pathway includes a longitudinal passage and a radial passage.

A hydraulic lash adjuster (HLA) sleeve configured to be received within a lifter bore of an engine block, includes a cylindrical sleeve having an outer surface defining an outer diameter, and an inner surface defining an inner diameter. The outer diameter is sized for an interference fit with the lifter bore to prevent rotation of the HLA sleeve within the lifter bore. The inner diameter is sized to receive a lifter.

An engine roller lifter for use in a leak-valvetrain of an internal combustion engine includes a body, a roller and an anti-rotation plug. The body includes an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied oil by an oil passage communicating therewith. The body defines an opening. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. The anti-rotation plug is received at the opening and has a plug body including an anti-rotation protrusion that extends radially beyond an outer peripheral surface of the plug body. The anti-rotation plug can be staked into the opening of the body.

An engine valve lifter assembly comprises a lifter body, a plunger assembly, and a spring. The lifter body comprises an oil control portion comprising an exterior surface, oil ports, and an interior oil chamber. A plunger interface end comprises an interior plunger chamber and a second spring seat. Selectively reciprocating plunger assembly comprises a piston end coupled to reciprocate in the oil chamber and a cam input end comprising a spring seat. A spring is biased between the spring seat and the second spring seat. The spring is configured to push the cam input end away from the plunger chamber. A sleeve is coupled around the oil control portion of the lifter body, and the sleeve is slidable between a lower position and an upper position to selectively block and unblock the oil ports.

Provided is a tappet capable of supplying lubricating oil to a cam even when provided with a lash adjuster.

A tappet (10) includes: a lash adjuster (11) having a plunger (14) and a body (13) in which the plunger (14) is housed so as to be vertically movable, wherein the plunger (14) has a top portion (16) against which a lower end portion of a push rod (88) slidably abuts; and a tappet body (12) which has an assembly hole (45) in which the body (13) is inserted, has a cup-like shape, and has a lower surface portion (27) which slidingly contacts a cam (70). The tappet body (12) has an oil guide passage (30) extending so as to guide lubricating oil from the push rod (88) side to the cam (70).

A variable valve train module selectively controls the opening and closing of a valve of an engine. The variable valve train module includes a drive element configured to be driven by a cam which rotates on a camshaft, a pump which is driven by the drive element, and a hydraulic control unit. The hydraulic control unit is configured to control the engine valve. The hydraulic control unit has a high pressure chamber containing hydraulic fluid which is selectively pressurized by the pump. The hydraulic control unit also has a control valve which is configured to depressurize the high pressure chamber, and a damper which is configured to increase an effective volume of the high pressure chamber when a pressure in the high pressure chamber exceeds a threshold value.

A method for controlling vehicle speed comprises selecting an engine speed profile for a vehicle. Road grade data is received and processed to determine a road grade for the vehicle. Vehicle speed data is received and processed to determine a vehicle speed for the vehicle. A cylinder deactivation mode for a valvetrain of a multi-cylinder engine of the vehicle is selected. The cylinder deactivation mode comprises deactivating one or more intake valve, exhaust valve, and fuel injection for one or more cylinder of the multi-cylinder engine. The selected cylinder deactivation mode provides a controlled deviation from the selected engine speed profile at the road grade and vehicle speed.

A variable displacement internal combustion engine control system includes an engine having cylinders, each having an intake valve and an exhaust valve. An engine control module determines when to activate and deactivate the cylinders, and when to purge gas entrained in an oil system. A solenoid-actuated hydraulic control valve communicates with the engine control module to deactivate and activate individual cylinders. An air accumulation estimation program running multiple times per second for each of the cylinders identifies an approximate gas volume accumulating in a control port of the solenoid-actuated hydraulic control valve and if the gas volume has reached a predetermined threshold allows a purge pulse to be issued. The purge pulse initiates at a purge pulse initiation point during one of intake valve lift, exhaust valve lift, and when valve lifters of both the intake and the exhaust valve are on a base circle providing zero lift.

A hydraulic lash adjuster (HLA) sleeve configured to be received within a lifter bore of an engine block, includes a cylindrical sleeve having an outer surface defining an outer diameter, and an inner surface defining an inner diameter. The outer diameter is sized for an interference fit with the lifter bore to prevent rotation of the HLA sleeve within the lifter bore. The inner diameter is sized to receive a lifter.