Westport Power Inc.

Westport Research Inc.

Westport Fuel Systems Canada Inc.

Alan B Welch

Mark E Dunn

Mike Hebbes

Irawan Rahardja

Sandeep Munshi

David Kalu Mumford

Philip G Hill

Gordon P McTaggart-Cowan

Guowei Li

Dehong Zhang

Alain Michel Touchette

Richard Wing

John Milton Lapetz

Hamed Karimi Sharif

Colin W Blair

Gordon P Mctaggart-Cowan

John M Lapetz

Fuel injection accuracy of gaseous fuel injectors is important for efficient engine operation. However, the performance of the injectors varies from part to part and across their lifetime, and when an injector is under performing according to its specification it is often unknown what is causing the problem. An apparatus for operating a gaseous fuel injector in an engine comprises a mass flow sensor that generates a signal representative of the mass flow rate of the gaseous fuel in a supply conduit in the engine. A controller connected with the injector and the mass flow sensor is programmed to actuate the injector to introduce gaseous fuel into the engine; determine the actual mass flow rate of the gaseous fuel based on the signal representative of the mass flow rate; calculate a difference between the actual mass flow rate and a desired mass flow rate; and adjust at least one of on-time of the gaseous fuel injector and a magnitude of an injector activation signal by respective amounts based on the difference when the absolute value of the difference is greater than a predetermined value.

Operating a gaseous fuel injector

A flexible-fuel internal combustion engine apparatus comprises a combustion chamber, an intake valve, a first fuel injector, a second fuel injector, and a computer. The intake valve is operable to admit an intake charge into the combustion chamber. The first fuel injector injects a gaseous fuel directly into the combustion chamber. The second fuel injector injects a liquid fuel into the intake charge upstream of the intake valve. The computer is operatively connected with the first fuel injector and the second fuel injector to actuate injection of fuel respectively therefrom. The computer is programmed to command a gaseous-to-liquid fuel ratio as a function of at least one operating parameter from a group comprising gaseous fuel pressure, gaseous fuel mass, engine speed, engine torque, inlet air temperature, inlet air humidity, knock detection, operating history, torque command, and emissions.

Apparatus and method for fuelling a flexible-fuel internal combustion engine

A method and apparatus are disclosed for introducing a gaseous fuel into a combustion chamber of an internal combustion engine. The method includes dividing the engine map into three distinct operating regions, with different operating modes in each region. When the engine is operating in a low load region, gaseous fuel is introduced to the combustion chamber during an intake stroke before an intake valve associated with the combustion chamber closes. When the engine is operating in a high load low-speed region, gaseous fuel is directly injected into the combustion chamber during a compression stroke after the intake valve is closed. When the engine is operating in a high load high-speed region, a split injection strategy is employed with a first portion of the gaseous fuel introduced into the charge before the intake valve closes and a second portion being injected after the intake valve is closed.

Mid-cycle fuel injection strategies

In a gaseous-fuelled stoichiometric compression ignition internal combustion engine, a pilot fuel is injected directly into the combustion chamber to help initiate a multi-point ignition. The engine provides performance improvements approaching those of high pressure direct injection engines but with less complexity because the gaseous fuel is introduced into the intake air subsystem at relatively low pressure and as a result of the stoichiometric combustion, the low oxygen content in the combustion products exiting the combustion chamber allows the use of a three-way catalyst instead of other after treatment arrangements normally associated with conventional compression ignition engines that require the addition of a reductant.

Gaseous-fuelled stoichiometric compression ignition internal combustion engine

A method is provided for operating a directly actuated valve that comprises a strain-type actuator to actuate a valve member to travel between a closed position and an open position, the method comprising transmitting displacements from the strain-type actuator to the valve member, maintaining a compressive stress on the actuator that is greater than a predetermined minimum stress by applying a pre-load compressive stress and limiting to less than predetermined limits at least one of: (a) acceleration and deceleration of the valve member when moving between open positions and the closed position; and (b) velocity of said valve member immediately before contacting the valve seat.

Directly actuated valve with a strain-type actuator and a method of operating same

A glow member, preferably in the shape of a ring, assists ignition and combustion of a fuel used in an internal combustion engine. A fuel injection valve injects a plurality of fuel jets directly into a combustion chamber during operation of the engine so that the fuel jets are aimed to the proximity of the glow member such that ignition of fuel in each fuel jet is assisted by the glow member. The glow member is made from high temperature materials and can include catalytic materials to further promote combustion. The glow member can be actively heated, for example by an electric current, in addition to being passively heated by the heat generated within the combustion chamber by the combustion of the fuel therein.

Glow ring ignition assist for internal combustion engine

A directly actuated injection valve comprises a hollow valve housing, a valve member disposed within the hollow interior, a biasing mechanism, an actuator assembly and a passive hydraulic link assembly. The valve member is movable between a closed position and an open position for governing the flow of fuel into the combustion chamber of an internal combustion engine. The biasing mechanism, preferably a spring, biases the valve member in the closed position. The actuator assembly generates an opening force that acts against the valve spring to open the valve. The hydraulic link assembly is interposed between the valve member and the valve spring and the actuator assembly. The hydraulic link assembly transmits respective closing and opening forces to the valve member. The hydraulic link preferably comprises a piston disposed within a cylinder that is filled with a hydraulic fluid.

Directly actuated injection valve

A directly actuated injection valve comprises a hollow valve housing, a valve needle disposed within the hollow interior, a needle spring, an actuator assembly, and a hydraulic link assembly. The valve needle is movable between a closed position and an open position for governing the flow of fuel into the combustion chamber of an internal combustion engine. The displacement of the valve needle from the closed position is defined as the lift. The a needle spring biases the valve needle in the closed position. The actuator assembly generates an opening force that acts against the needle spring to open the valve. The hydraulic link assembly is interposed between the valve needle and the needle spring and the actuator assembly. The hydraulic link assembly transmits respective closing and opening forces to the valve needle. The hydraulic link preferably comprises a piston disposed within a cylinder that is filled with a hydraulic fluid. The opening and closing forces are transmitted through a thickness of the hydraulic fluid that is trapped between the planar surfaces of the piston and the head and base of the hydraulic cylinder. In the preferred embodiment, the thickness of the hydraulic fluid trapped between the piston and cylinder head or base is automatically adjustable in response to changes in the dimensional relationship between components of the injection valve to maintain a desired valve needle lift when the actuator assembly is activated. When the actuator assembly comprises a magnetostrictive or piezoelectric member, the movements of the valve needle can be controlled by the application of a shaped control pulse or waveform to improve the speed of the opening and closing motion of the valve needle, and to reduce the impact of the valve needle on the valve seat upon closing.

Growing community of inventors

Vancouver, Canada

Alan B Welch