Cummins Engine Company, Inc.

Amarjit S Ghuman

Lester L Peters

Julius P Perr

Edward D Smith

Benjamin M Yen

David L Buchanan

Yul J Tarr

Laszlo D Tikk

Robert C Yu

Peter Vinson Woon

David A Vittorio

Rod Radovanovic

Harold G Weber

P Douglas Free

Brian E Walsham

Isoroku Kubo

Chung Y Liu

Canden R Nelson

Byron J Bunker

John M Janssen

Steven C Francis

Rodoljub Radovanovic

Andrew G Stiles

Eric Liang

A system and a method for hydraulic actuation of poppet valves. The poppet valve is opened by application of hydraulic pressure to a piston, and is closed by action of a mechanical spring. Hydraulic pressure comes from either a high pressure source of a low pressure source, the low pressure source being higher than ambient pressure. Application of hydraulic pressure is made by a pressure control device based upon signals received from an electronic controller. Hydraulic pressure is applied in a way that minimizes the power required to actuate the valve by making use of valve inertia.

Dual-pressure hydraulic valve-actuation system

An exhaust valve system for an internal combustion engine including a turbocharger is provided for effectively increasing the turbocharged boost pressure at low load engine conditions thereby effectively improving engine transient response. The exhaust valve system includes an exhaust valve control device operable in a normal timing mode for permitting normal opening of one or more exhaust valves at a normal opening crank angle, and in an advanced timing mode for advancing the timing of the opening of the exhaust valve to an advanced opening crank angle prior to the normal opening crank angle while maintaining the timing of normal closing of the exhaust valves at a normal closing crank angle. In one embodiment, the exhaust valve control device includes a tappet and an actuating fluid supply which operate to move the tappet between expanded and collapsed states to advance the opening of the exhaust valve while permitting normal exhaust valve lift to be introduced prior to peak exhaust valve lift thereby maintaining the normal peak lift and the normal timing of exhaust valve closure. In a second embodiment, the exhaust valve control device includes a dedicated advanced timing mode rocker lever capable of selectively actuating one of a pair of exhaust valves to create an early opening exhaust event prior to a normal exhaust event.

Early exhaust valve opening control system and method

Fuel injection rate shaping is integrated into the pressure intensification stage of a hydraulically actuated fuel injector having a pressure intensifier. In a first embodiment, the pressure intensification plunger is formed of two parts creating a damping chamber therebetween from which fluid is forced out through orifices in a lower one of the plunger parts during an initial phase of displacement of the upper part. Thus, injection will be performed initially at a lower pressure and rate, which increases once the plunger parts make contact. In a second embodiment, a throttled flow is set via a restrictor housing that telescopingly receives the upper plunger part, so that a lower injection rate occurs while fluid is bled off through a restricted flow path between the restrictor housing and the upper plunger part, and a higher injection rate is produced once a port in the upper plunger clears the restrictor housing. In a third embodiment, the two plunger parts of the intensifier have different areas relative to each other. In a fourth embodiment, flow to the intensifier plunger is varied by the intensifier plunger co-acting with a shaped inlet port increasing the effective area of the inlet port through which flow enters the intensifier as the intensifier plunger is displaced during its injection stroke. In a fifth embodiment, a throttling effect produced by a clearance between a protrusion on the intensifier plunger and a receiving bore in the intensifier body is used reduce the intensification effect during the initial phase of injection.

Hydraulically actuated fuel injector with injection rate shaping

In accordance with preferred embodiments of the invention a timing adjustment device includes a cam follower that is engaged between an overhead cam and an injector rocker arm, and is mounted on a rotatable eccentric shaft. The geometry of the eccentric shaft and cam follower is designed so that, as timing is varied by rotation of the eccentric shaft, no change is produced in the vertical height of the rocker arm when the cam shaft is on the outer base circle and the injector is bottomed, in order to assure that the 'mechanical crush' of the PT type injector is constant despite changes in timing. In a first application of the timing arrangement, it is used together with a simple injector, which does not utilize a multi-plunger arrangement to form a hydraulic link, to achieve lower parasitic losses. To obtain independent control over injection pressure and timing, a fuel injector in which a hydraulic link is formed between plungers of a multi-plunger arrangement is used with the timing arrangement in order to allow the injection pressure to be maintained constant over a wide range of engine speeds without interfering with engine timing.

Variable injection timing and injection pressure control arrangement

A turbocompound engine having a power turbine bypass valve and a control module for controlling opening and closing of the bypass valve. The control module opens the bypass valve for various operating conditions, such as at high altitudes, low speed/high load, and transient load conditions for improved engine operation.

Turbocompound engine with power turbine bypass control

A cam for controlling the injection rate of fuel in a fuel injection system having a four part cam profile is disclosed. The first 120.degree. is the plunger advancement segment. The next 80.degree. is the advanced dwell segment. The next 100.degree. is the plunger retraction segment and the last 60.degree. is the retracted dwell segment. The plunger advancement segment is divided into three subsegments: pre-injection stroke, injection stroke, and overtravel stroke. The pre-injection subsegment achieves minimum velocity and acceleration at the start of injection. In the injection subsegment, the cam follower acceleration is achieved as rapidly as can Hertz stress permits to increase the injection pressure and to achieve the maximum injection rate. The overtravel subsegment achieves a sharp and clean end of injection. Preferably, this cam causes injection of less than 20 mm.sup.3 of fuel per stroke during the first ten cam angle degrees of cam rotation. The injection pressure and the amount of injection are reduced at the beginning of injection, timing is advanced, and optimal control over the rate of fuel injection is provided.

Injection rate control cam

A system is provided for increasing the efficiency of internal combustion engines operating at high loads and more particularly to a multi-cylinder engine in which at least one cylinder is used as the power recovery device. The waste heat generated during operation of the engine is utilized for producing an amount of energy to perform the work by means of a Rankine cycle.

Rankine-diesel integrated system

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Columbus, IN, United States of America

Amarjit S Ghuman