894 results about "Engine knocking" patented technology

An engine system and method are disclosed for controlling pre-ignition of an alcohol fuel. In one embodiment, the fuel injection timing is adjusted to cause the fuel to avoid combustion chamber surfaces. In another embodiment, the fuel injection timing is adjusted to spray the fuel directly onto the piston surface to cool the piston. Also disclosed is a cylinder cleaning cycle in which engine knock is purposely caused for one to hundreds of engine cycles by adjusting the fuel content away from alcohol toward gasoline. Further measures to cause knock which are disclosed: adjusting spark timing, intake boost, exhaust gas fraction in the cylinder, cam timing, and transmission gear ratio.

An environmentally clean dual fuel for an internal combustion engine, comprising acetylene as a primary fuel and a combustible fuel, such as one or more fluids selected from an alcohol such as ethanol, methanol or any other alcohol or alcohols from the group comprising C1-C20 carbon chains, ethers such as from the group comprising dimethyl ether, diethyl ether, methyl t-butyl ether, ethyl t-butyl ether, t-amyl methyl ether, di-isopropyl ether and the like, low-molecular-weight esters such as from the group comprising methyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate and the like, or other suitable combustible fluid such as mineral spirits and the like, as a secondary fuel for operatively preventing early ignition and knock arising from the primary fuel. The dual fuel, internal combustion system, which generally utilizes a two-stage process for start-up and operation and can be operated with air- or liquid-cooling, is environmentally clean with hydrocarbon, CO, NOx, and SOx emissions substantially eliminated.

A method of mounting an accelerometer to an internal combustion engine comprises securing the accelerometer to a mating surface on an engine component external to a combustion chamber where the accelerometer can generate a signal output that is characteristic of engine knock, when it occurs, and at least one other combustion behavior inside the combustion chamber during a combustion event. The method further comprises connecting a signal wire at one end to the accelerometer and at an opposite end to a signal processor, and increasing the signal output's signal-to-noise ratio.

A method for processing knock-related data reduces the memory locations required for the method and also simplify the processing steps needed to determine a sum, average, and threshold value relating to magnitudes of knock ratios. Inputs from either pressure sensor or accelerometers are filtered and then used to form a ratio between a knock portion of a curve and a reference portion. Sequential magnitudes of the knock ratio are received and analyzed in a manner that reduces required memory locations and improves processing speed.

An engine ECU executes a program including a step of calculating coefficient of correlation K that is a value related to a deviation between a vibration waveform and a knock waveform model by comparing the engine's vibration waveform with the knock waveform model stored in advance at a plurality of timings, a step of calculating a knock intensity N as based on a largest coefficient of correlation K among the calculated coefficient of correlation Ks, a step of determining that the engine knocks if knock intensity N is larger than a predetermined reference value (YES at S108), and a step of determining that the engine does not knock if knock intensity N is not larger than a predetermined reference value (NO at S108).

A pulsed detonation engine having improved efficiency has a detonation chamber for receiving a detonable mixture, an igniter for igniting the detonable mixture, and an outlet for discharging detonation products. A diverging-converging nozzle is provided at the outlet of the detonation chamber. The geometry of the diverging-converging nozzle is selected to enable a relatively short nozzle to significantly improve efficiency of the pulsed detonation engine.

Internal combustion ("IC") engine system for high fuel conversion efficiency and low exhaust emissions, particularly although not exclusively with gaseous fuels. An IC engine operates at approximately stoichiometric (lambda=1) air/fuel mass ratios. A higher-than-normal compression ratio for typical stoichiometric operation is possible for the engine, due to the introduction of an inert (i.e., not chemically reactive in the combustion process) gas into the air/fuel mixture. The inert gas slows the combustion rate to avoid uncontrolled combustion rates and engine "knock." The elevated compression ratio yields higher fuel conversion efficiency. Stoichiometric air/fuel ratio permits catalytic processing of the exhaust gas stream to reduce CO, NOx, and HC emissions via a combination of non-selective catalytic reduction process.

A knock detection system for a spark-ignition engine includes a knock sensor that is responsive to vibration of the engine and that generates a knock signal. A first module calculates a knock energy based on the knock signal and a second module calculates a knock intensity based on the knock energy. A third module regulates a spark timing of the engine based on the knock intensity.

A pulse detonation system for a gas turbine engine having a longitudinal centerline axis extending therethrough, the pulse detonation system includes an air inlet duct in flow communication with a source of compressed air, the air inlet duct including at least one port formed therein for permitting compressed air to flow therethrough, a fuel injector mounted to the air inlet duct in circumferentially spaced relation to each port, and a device mounted to the air inlet duct in circumferentially spaced relation to each fuel injector for initiating a detonation wave. A rotatable ring member is also positioned in coaxial relation around a portion of the air inlet duct, with the ring member including at least one stage of detonation disposed therein. Accordingly, a detonation wave is produced in each detonation stage and combustion gases following each detonation wave create a torque which causes the ring member to rotate. Each detonation stage in the ring member further includes a plurality of circumferentially spaced detonation ducts extending tangentially from an inner surface of the ring member, wherein the detonation ducts are aligned with each port, the fuel injector and the initiation device in a predetermined timing and sequence so that detonation waves are produced therein.

Methods of mitigating the occurrence of a low-speed pre-ignition event in a multi-cylinder internal combustion engine (10), the engine (10) having a computerized engine management control module (70) and an ignition timing module (66) controllable by the engine management control module (70). The computerized engine management module (70) monitors the operating conditions of the internal combustion engine (10) and at certain operating conditions dithers the ignition timing of at least one cylinder (20) of the engine (10) to induce light to medium SI engine knock temporarily. Due to the high temperature, high frequency pressure waves caused by SI engine knock, fuel and/or lubricant related deposits accumulated on combustion chamber components, i.e. top piston land crevices or piston crown, are consumed so that said deposits (60) cannot become a source of pre-ignition

An engine ECU executes a program including the steps of: detecting a waveform of vibration of an engine at a predetermined knock detection gate; determining whether a detected vibration's waveform and a knock waveform model stored in memory match within a predetermined range; if the model and the detected vibration's waveform match within the predetermined range, determining that the engine knocks; and if the model and the detected vibration's waveform do not match within the predetermined range, then determining that the engine does not knock.

In an automotive system (300), a knock detection scheme is provided for detecting knock events in an internal combustion engine that are sensed by a transducer structure, such as a non-intrusive acoustic accelerometer sensor (310) to generate sensor signal information which is processed by a signal processing structure (312, 316, 318, 326) which extracts digital signal parameters from the sensor signal information to identify a predetermined pitch frequency (330) and any short-term energy increase (328) in the digital signal information which in combination are used to provide a positive indication of engine knock behavior. When a short term Fourier transform (324) is used to extract the digital signal parameters, time frequency resolution may be improved by appropriately windowing the digital signal being transformed.

Methods and systems are provided for improving engine knock tolerance, in particular when rapidly ramping in LP-EGR from low levels of EGR. Until a desired LP-EGR rate is achieved, fuel may be delivered as a split injection with at least an intake stroke injection and a compression stroke injection to compensate for the transport delay in EGR filling the intake system. Subsequently, single fuel injection may be resumed.

The present invention creates a method and an apparatus for blanking out interfering noise in connection with detecting knocking in an internal combustion engine. The following functions are performed: Forming a sensor signal integral value (KI) during a measurement time slot (MF) of the sensor signal of a knocking sensor; forming a correction value (DKI) for the sensor signal integral value (KI) corresponding to an interfering noise during the measurement time slot (MF); and subtracting the correction value (DKI) from the sensor signal integral value (KI) for forming a corrected sensor signal integral value (KI') with the interfering noise blanked out.

An engine is provided with a variable valve mechanism capable of changing a degree of an operating angle and a phase of a valve-open period of an intake valve. A controller selectively executes at least one of a plurality of knock controls including a phase adjustment of the valve-open period of the intake valve when a knocking is detected by a knock sensor. When the operating angle of the intake valve is smaller than 180 degrees, a knock control is selected and executed such that a valve-open timing IVO of the intake valve does not exceed a predetermined timing (TDC+α) retarded from a top dead center TDC by a predetermined angle α. Specifically, for example, when the operating angle is smaller than 180 degrees and the valve-open timing IVO of the intake valve is after the top dead center TDC, the valve-open timing IVO is advanced.

The invention discloses a pre-combustion generator. The pre-combustion generator is mounted in an oil spraying device mounting hole on an engine cylinder cover, and comprises a pre-combustion generator body, wherein the pre-combustion generator body is provided with a pre-combustion chamber; the pre-combustion generator body is provided with a spraying hole for communicating the pre-combustion chamber with a combustion chamber; the pre-combustion generator body is further provided with a gas supplying device for supplying gas to the pre-combustion chamber; the pre-combustion chamber is provided with a sparking plug mounting hole; the sparking plug mounting hole is internally provided with a sparking plug; the pre-combustion generator body is further provided with a cooling device. The pre-combustion generator is provided with an independent cooling system, a gas feeding system and a control system so that one independent product is formed and the product can be conveniently applied to a diesel engine to be refitted into a gas engine; the tendency of detonation in a main combustion chamber can be reduced and the compression ratio of the existing gas engine can be increased; a piston and the cylinder cover do not need to be redesigned to change the compression ratio; the heat efficiency of the gas engine can be effectively improved and energy sources are saved.