The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 19, 1999
Filed:
Mar. 24, 1997
Yul J Tarr, Columbus, IN (US);
Cummins Engine Company, Inc., Columbus, IN (US);
Abstract
An improved nozzle assembly for servo-controlled fuel injectors is provided which includes a needle valve control device including a rate shaping control device for effectively producing a predetermined time varying change in the flow rate of fuel injected into the combustion chamber during an injection event so as to reduce emissions. The rate shaping control device includes an injection control valve positioned along a drain circuit connected to a control volume positioned at one end of the needle valve element. The injection control valve includes an actuator for controlling the flow of fuel through the drain circuit to variably control the rate of movement of the needle valve element between the open and closed positions so as to provide the desired shaping to the flow rate of fuel into the combustion chamber. The injection control valve may include a control valve element positioned in the control volume adjacent the needle valve element for cooperating with the needle valve element to control the drain flow of fuel through the drain circuit during the injection event. The needle valve element may include a valve surface wherein positioning of the control valve member relative to the valve surface controls drain flow through the drain circuit. The valve surface may be either a flat valve surface or a conically shaped surface for positive abutment by the control valve member, or alternatively, the needle valve element and the control valve member may be of the spool-type.