Abstract:
A premixed-charge compression-ignition engine, and a control system (10), is provided which effectively initiates combustion by compression-ignition and maintains stable combustion while achieving extremely low nitrous-oxide emissions, good overall efficiency and acceptable combustion noise and cylinder pressures. The present engine and control system (10) effectively controls the combustion history, that is, the time at which combustion occurs, the rate of combustion, the duration of combustion and/or the completeness of combustion by controlling the operation of certain control variables providing temperature control, pressure control, control of the mixture's auto-ignition properties and equivalence ratio control. The combustion control system (10) provides active feedback control of the combustion event and includes a sensor (16) for detecting an engine operating condition indicative of the combustion history, e.g. the start of combustion, and generating an associated engine operating condition signal (18).
Abstract:
A thermal barrier coating for metal articles subjected to rapid thermal cycling includes a metallic bond coat deposited on the metal article, at least one MCrA1Y/ceramic layer deposited on the bond coat, and a ceramic top layer deposited on the MCrAlY/ceramic layer. The M in the MCrA1Y material is Fe, Ni, Co, or a mixture of Ni and Co. The ceramic in the MCrAlY/ceramic layer is mullite or Al2O3. The ceramic top layer includes a ceramic with a coefficient of thermal expansion less than about 5.4 x 10 DEG C and a thermal conductivity between about 1 J sec m DEG C and about 1.7 J sec m DEG C .
Abstract:
Un mécanisme à poulie de tension (20) permet de maintenir la tension d'une courroie de transmission (18) dans un système à courroie de transmission, comprenant un bras (22) d'une poulie de tension, une poulie (24) montée sur le bras en rotation autour d'un axe de rotation (26), une plaque de montage réglable de manière pivotante (30), un moyen (28) de montage pivotant du bras sur la plaque de montage excentriquement par rapport à l'axe de pivotement de la plaque, et des moyens élastiques (54) associés effectivement au moyen de montage pivotant pour solliciter élastiquement la poulie (24) en engagement de tension avec la courroie de transmission (18). L'application d'un couple prédéterminé sur l'axe de pivotement de la plaque réglable donne à la courroie de transmission une tension sensiblement constante indépendamment de la longueur de la courroie, dans des tolérances prédéterminées.
Abstract:
A fuel injection rate shaping control system is provided which effectively controls the flow rate of fuel injected into the combustion chamber of an engine to improve combustion and reduce emissions by controlling the rate of pressure increase during injection. The injection rate shaping control system includes a rate shaping control device (10) including a rate shaping transfer passage (22) having a predetermined length and diameter specifically designed to create a desired injection pressure rate shape. In other embodiments of the present invention, two or more rate shaping transfer passages (72, 74) capable of producing distinct rate shapes are packaged in various fuel injection systems to selectively provide various rate shapes depending on operating conditions. Switching valves, i.e. solenoid operated three-way valves (76, 84, 86), may be used to direct the fuel or timing fluid flow to any one of the rate shaping transfer passages. Also, a dampening means in the form of a reverse flow restrictor valve (26) is positioned in the rate shaping transfer passage to dampen reflected pressure waves thereby minimizing the adverse effects thereof.
Abstract:
A fuel injector (10) includes a plunger assembly (20) disposed within a central axial bore (18) and including a lower plunger (22), an intermediate plunger (24), and an upper plunger (26). The lower plunger (22) reciprocates to meter a variable quantity of fuel and to inject this fuel. A timing chamber (34) formed between the upper and intermediate plungers (26, 24) receives an amount of timing fluid to create a variable length hydraulic link between the plungers (26, 24). The fluid is drained from the chamber (34) through a drain passage (38) at the end of the injection cycle. In a preferred embodiment, the drain passage (38) is located along the central axis of the intermediate plunger (24), and the upper plunger (26) is provided with a projecting portion (29) which moves into position as the timing chamber (34) collapses to effectively constrict the drain passage (38), thus changing the timing fluid flow function to a function which provides greater fluid pressure in the timing chamber (34), maintaining a large downward force on the lower plunger (22) preventing additional, undesired fuel flow into the combustion chamber.
Abstract:
Ensemble refroidisseur-filtre (2) comprenant une enceinte (4) du refroidisseur contenant une cavité (14) intérieure allongée qui s'ouvre aux faces terminales (16 et 18) généralement planaires, de l'enceinte (4) du refroidisseur; l'ensemble comprend aussi une structure de support (6) qui permet de monter l'enceinte (4) du refroidisseur sur un moteur à combustion interne et de former des passages (104, 106, 108 et 110) internes d'alimentation et de retour aussi bien pour le réfrigérant du moteur que pour le lubrifiant à travers une seule face terminale planaire (16) de l'enceinte (4) du refroidisseur. Une soupape (118) à commande thermostatique et un dispositif (80) de soupape sensible à la pression de l'huile commandent le flux de l'huile à travers l'ensemble (2) refroidisseur-filtre afin d'assurer un fonctionnement efficace et sûr de l'ensemble (2). Un dispositif d'échange thermique (24) comprend un organe (30) fixe ayant la forme d'une plaque, sur lequel est montée une des extrémités d'une pluralité de tubes allongés (26). Cet organe (30) contient également des orifices d'alimentation et de retour d'huile (54 et 56), qui permettent de simplifier l'agencement des passages du flux d'huile à l'intérieur de l'ensemble (2).
Abstract:
An improved HCCI engine and control scheme is provided which produces stable HCCI combustion while optimally minimizing emissions and maximizing efficiency. In the present invention, the fuel/air mixture is thoroughly mixed to form a very lean homogeneous mixture, or is mixed in a manner to form a desired air/fuel stratification, to ensure relatively even, low flame temperatures which result in extremely low NOx emissions. The control system senses the start of combustion, the combustion rate and/or the combustion duration and, based on the sensed condition, actively controls the temperature, pressure, equivalence ratio and autoignition properties to continuously maintain optimum combustion.
Abstract:
Improved fatigue strength properties are achieved in an induction hardened microalloy steel useful for demanding service environments. The microalloy steel has low carbon and sulfur contents, comprising in % by weight, 0.15 % to 0.45 % C, 0.50 % to 1.60 % Mn, up to 0.20 % V, 0.001 % to 0.01 % S, balance Fe. The material is fabricated to a selected configuration, such as an engine crankshaft, for example. Selected surfaces of the fabricated article are hardened by induction heating. The article can be used directly after induction hardening or it may be tempered at low to moderate temperatures of from about 100 DEG C (200 DEG F) to 290 DEG C (550 DEG F) to achieve a desired surface hardness and compressive residual stress level. The controlled alloy chemistry and low tempering temperature provide a substantial increase in bending fatigue strength over conventional higher carbon grade steels.
Abstract:
A fuel injector (1, 2) which uses interchangeable subassemblies (10, 11) to allow the injector to be converted from open to closed nozzle options without affecting engine installation, and without altering the timing or metering principles. The fuel injector (1, 2) is comprised of two subassemblies, a first subassembly of which is a timing or control subassembly (13) that is used with both the open and closed nozzle options, and a second subassembly which is formed in two versions, an open nozzle version (11) and a closed nozzle version (10).
Abstract:
A ceramic-metal composite structure which minimizes tensile ceramic loads and accommodates differences in thermal expansion characteristics between a metal member and a ceramic member without reliance on precise feature control for either member. The composite includes a mechanical retainer which allows a loose fitting relationship between the metal and ceramic members. The ceramic member is secured within a receiving bore in the metal member by the retainer in a manner which eliminates the need for precise machining of the ceramic and metal members. The metal member may be configured to accept either an internal or an external mechanical retainer element. The composite ceramic-metal structure of the present invention finds particular utility in forming a durable wear-resistant interface in internal combustion engine actuator or actuating components, such as compression brake master pistons.