2003 results about "Cylinder pressure" patented technology

This disclosure teaches a method of controlling a direct injection internal combustion engine and predicting the behaviour of a direct injection internal combustion engine. An estimation of initial cylinder pressure, air flow and EGR flow (if applicable) is used to establish a system that provides engine behaviour by integrating an injection module, combustion module and engine control module to provide data indicative of engine behaviour such as brake torque and power, air flow, EGR flow, cylinder pressure, brake specific fuel consumption, start of combustion, heat release rate, turbo-charger speed and other variables. These values can then be used to adjust commanded variables such as start of injection, commanded pulse width, rail pressure to meet operator demand. Also the output data can be used as a tool to determine how a conceptualised engine design will behave. This is particularly useful for gaseous-fueled internal combustion engines where cylinder pressure influences behaviour of injected gases in light of the fact that rail pressure and cylinder pressure are, generally, of a similar magnitude.

Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.

An exhaust valve arrangement for use in a combustion chamber of a compression ignition internal combustion engine, includes a piston which is movable outwardly from the combustion chamber in response to pressure generated within the combustion chamber as a result of combustion, and an outer sleeve within which the piston is movable. The outer sleeve is an exhaust valve which is actuable between open and closed positions to open and close, respectively, an exhaust passage from the combustion chamber. The exhaust valve arrangement further includes a pump chamber for receiving fluid, and a pumping plunger coupled to the piston and movable with the piston so as to pressurise fluid (e.g. fuel) within the pump chamber as the piston is urged outwardly from the combustion chamber. The pressure within the pump chamber is proportional to cylinder pressure and is sensed by a sensor which provides an output signal to an Engine Control Unit (ECU 16). An accumulator volume receives fluid that is pressurised within the pump chamber. Where the fluid is fuel, the accumulator volume is arranged to deliver fuel to one or more injectors of a common rail fuel injection system. Alternatively the accumulator volume may be arranged to deliver pressurised fluid to one or more engine systems e.g. for actuation purposes.

A split injection of gasoline produces stratified charge in at least one cylinder. A sensor measures cylinder pressure or knock and generates a sensor signal indicative of combustion event timing of stratified charge. From the sensor signal, a controller determines an actual value of a characteristic parameter representing combustion event timing in the cylinder. The controller modifies at least one of operating variables governing a split injection for the subsequent cycle in such a direction as to decrease a deviation between the actual value of the characteristic parameter and a target value thereof toward zero.

A gaseous-fuelled internal combustion engine and a method of engine operation improve combustion stability and reducing emissions of NOx, PM, and unburned hydrocarbons. The method comprises fuelling an internal combustion engine with hydrogen and natural gas, which can be directly injected into the combustion chamber together or introduced separately. Of the total gaseous fuel delivered to the engine, at least 5% by volume at standard temperature and pressure is hydrogen. For at least one engine operating condition, the ratio of fuel rail pressure to peak in-cylinder pressure is at least 1.5:1. A fuel injection valve introduces the gaseous fuel mixture directly into the combustion chamber. Two separate fuel injection valves could also introduce the methane and hydrogen separately. An electronic controller controls timing for operating the fuel injection valve(s). The engine has a preferred compression ratio of at least 14:1.

The present method and apparatus employ a signal indicative of cylinder pressure within the combustion chamber of an internal combustion engine to control combustion phasing or start of combustion (SOC) in subsequent cycles of the engine where the engine is driven by combustion of both a fuel / air premixed charge and a directly injected quantity of fuel. A ratio of signals indicative of pre-combustion pressure and post-combustion pressure within a cycle are employed to estimate SOC and then, based on a predetermined target SOC, an ignition lever is employed to adjust subsequent SOC. A preferred ignition lever is, in a pilot fuel ignited engine, pilot fuel quantity.

In a multi-cylinder engine having a compression ignition combustion mode, a vibration detecting sensor that is preferably mounted in a cylinder block or a cylinder head is used to detect a frequency and the detected frequency is appropriately analyzed to detect or estimate a cylinder pressure peak value and peak timing for each cylinder. An amount of internal EGR, a fuel injection condition, an engine speed and the like are then controlled so as to bring each of these parameters into an appropriate range thereof. The control apparatus suppresses variations in combustion states among different cylinders and different cycles arising from unit-to-unit variations or deterioration in the engine or part-to-part variations or deterioration in a component thereof.

A braking pressure control apparatus including a first pressure source including a power-operated pressurizing device, a second pressure source operable by a manually operable brake operating member to pressurize a fluid to a pressure higher than a level corresponding to the operating force of the brake operating member, a switching device for selectively placing the braking system in a first state in which a brake cylinder is operated with the fluid pressurized by the first pressure source and a second state in which the brake cylinder is operated with the fluid pressurized by the second pressure source, and a change restricting device operable upon a switching between the first and second states, to restrict a change of the operating state of the brake operating member and a change of the brake cylinder pressure, which change take place due to the switching, or a switching control device for controlling the switching device on the basis of the running condition of a vehicle whose wheel is braked by the braking pressure.

A control apparatus for an internal combustion engine having two cylinder groups and two variable valve control mechanisms provided to the respective cylinder groups, includes a detecting section that detects an incylinder pressure of each cylinder, a comparing section that makes a comparison between the two cylinder groups with respect to a combustion stability and a control section that varies valve lift characteristics of intake valves of one cylinder group which is larger in the average incylinder pressure than the other cylinder group in accordance with a result of comparison by the comparing section so as to make intake air quantities for the respective cylinder groups be equal to each other.

A control system and method to dynamically determine a parametric value for combustion chamber deposits (CCD), e.g. in a controlled auto-ignition engine, including in-situ evaluation of thickness of CCD, based on a sensor which monitors combustion. It includes a temperature sensor operative to monitor the combustion chamber, and a CCD parameter that is based upon a peak combustion temperature measured at a crank angle. A CCD parameter can also be determined utilizing an in-cylinder pressure monitor, wherein a combustion chamber deposit parameter is based upon crank angle location of a peak in-cylinder pressure parameter.