100 results about "Variable valve timing" patented technology

A valve timing control device includes: a unit for calculating a target valve timing for one of an intake valve and an exhaust valve in accordance with an operational state; a unit for detecting an actual valve timing of one of the intake valve and the exhaust valve; an actual valve timing control unit for generating a controlled variable for the VVT based on a difference between the target valve timing and the actual valve timing; a unit for learning a learning value of the controlled variable required for maintenance of the actual valve timing based on an integral correction value; and a unit for detecting a malfunction in a VVT from an amount of a shift in the actual valve timing when learning is not completed yet, and for detecting a malfunction in the VVT from the difference when learning is already completed.

The invention discloses a dual-fuel engine combustion control method based on hydrogen-ammonia energy ratio and gas distribution overlap angle regulation and control, which comprises the following steps: 1) fuel ratio control: acquiring current operation state parameters of an engine, determining a target AER according to preset mapping, regulating ammonia gas supply quantity and hydrogen supply quantity to enable the actual AER to reach the target AER, and controlling the fuel ratio; the AER is adaptively set according to engine load and combustion stability conditions; 2) valve timing control: adjusting the opening time of an intake valve or the closing time of an exhaust valve through a variable valve timing mechanism so as to change a valve timing overlap angle VOA, wherein the VOA is set to be a negative value, a small overlap angle or a positive overlap angle according to the working condition of an engine; (3) injection time sequence optimization is conducted, specifically, the injection time of ammonia gas and the in-cylinder direct injection time of hydrogen are controlled respectively, and coordinated optimization of a fuel injection strategy and valve timing is achieved; and 4) closed-loop steady-state control: monitoring a combustion state and an emission index in real time, comparing the combustion state and the emission index with a threshold value to serve as a feedback signal, and correcting the target AER and VOA settings in time. According to the dual-fuel engine combustion control method based on regulation and control of the hydrogen-ammonia energy ratio and the gas distribution overlapping angle, the energy ratio of hydrogen fuel and ammonia fuel and the overlapping opening angle of an intake valve and an exhaust valve are dynamically adjusted under different working conditions, so that the combustion reaction rate and temperature are coordinated, and the stable and efficient combustion process is achieved; and harmful emissions of NOx, unburned ammonia and the like are obviously reduced.

The invention discloses an engine control method and a related device, and the method comprises the steps: obtaining a current engine load parameter, a current engine power parameter and a current environment pressure value of the operation of an engine under the condition that the engine enters a dynamic VVT (Variable Valve Timing), and obtaining a control parameter of the engine based on the current engine power parameter and the current environment pressure value; and determining a quit dynamic VVT critical value meeting the current engine working condition, and controlling the engine to quit the dynamic VVT under the condition that the current engine load parameter and the quit dynamic VVT critical value meet the quit dynamic VVT condition. According to the method, when the dynamic VVT condition is determined to exit, the engine power parameters and the pressure value of the environment where the engine runs are comprehensively considered, so that it can be guaranteed that the dynamic VVT condition is exited to meet the running environment and power requirements of the engine, and the dynamic VVT condition can be exited under the condition that the required torque of the engine in a high-altitude area is large. And the condition that the engine frequently advances and retreats into the dynamic VVT is effectively avoided.

The invention discloses a control method and system of a hybrid vehicle and the hybrid vehicle, and relates to the technical field of vehicles. The method comprises the following steps: acquiring a plurality of sensing signals of the hybrid vehicle; identifying working state differences among cylinders of the engine based on the plurality of sensing signals; and in response to the recognized working state difference, layered control is conducted on an oil injection mechanism, a variable valve timing mechanism and an ignition mechanism, and a P2 motor is controlled. Therefore, the combustion stability, NVH performance and efficiency of the engine under the hybrid working condition can be improved.

The invention provides an engine control method and related equipment, and relates to the technical field of engine control. The engine control method comprises the steps that in response to an engine stop request, an engine is controlled to stop oil injection; the generator is controlled to drive the engine to run at a first preset rotating speed, the engine is controlled to execute exhaust operation, and the exhaust operation includes using a variable valve timing system and a throttle valve to exhaust mixed gas; and after the exhaust operation of the first preset duration is executed, the generator is controlled to reduce the rotating speed of the engine to zero. By means of the method, the problems of shaking and explosion sound caused by compression ignition of residual oil-gas mixed gas in the engine cylinder can be effectively solved.

The object of the present invention is to provide a combustion system and a combustion method for a diesel and ammonia dual-fuel engine based on a composite EGR circuit, including a combustion system, an electronic control system, a composite EGR circuit system, a variable valve system, a high-pressure common rail fuel system, and an ammonia supply system. The composite EGR circuit system includes three circuits: 1. an in-cylinder high-temperature EGR circuit based on variable valve timing, 2. an out-of-cylinder low-flow low-temperature EGR circuit, and 3. an out-of-cylinder high-flow low-temperature EGR circuit. The electronic control system controls the two concentric double-needle valve fuel injectors and the in-cylinder direct injection ammonia injector with a flexible injection strategy in combination with the composite circuit EGR system according to different working conditions and the combustion characteristics of the fuel, which can effectively control the mixing characteristics and ignition characteristics in the cylinder, thereby optimizing the in-cylinder combustion and significantly reducing emissions at the same time. The present invention can improve the performance of the engine under all working conditions, achieve high combustion efficiency and low emissions, and has good adaptability to low-temperature environments.

According to the engine system, the intake valve of the engine body is connected with the intake pipeline, and the exhaust valve of the engine body is connected with the exhaust pipeline, so that normal operation of the engine body is achieved; the engine body comprises a variable valve timing system, and the variable valve timing system comprises at least three different VVT MAPs used for controlling opening timing of an intake valve and closing timing of an exhaust valve so as to control the engine system under different operation conditions. According to the invention, the air inlet amount of the engine body can reach the best under different operation conditions, so that the engine system can reach higher combustion efficiency under different operation conditions, the oil consumption is reduced, and the economical efficiency of the engine system in the operation process is improved.

This internal combustion engine (1) has a hydraulically driven variable valve timing mechanism (8) capable of changing the valve timing of an engine valve. To change the valve timing of the engine valve, the internal combustion engine (1) temporarily increases the working hydraulic pressure supplied to the variable valve timing mechanism (8) to a target hydraulic pressure (Pt) at the time of switching. To change the valve timing of the engine valve, when the working hydraulic pressure becomes equal to or higher than a predetermined control-permission hydraulic pressure (Pc) lower than the target hydraulic pressure (Pt) at the time of switching, the internal combustion engine (1) starts control of the variable valve timing mechanism (8) to change the valve timing of the engine valve.

The invention discloses an engine control method and device and a storage medium, and belongs to the technical field of vehicle control. The method comprises the steps that the rotating speed, the load, the variable valve timing angle, the water temperature and the intake manifold temperature before an engine stops are obtained; calculating the oil film residual volume on the inner wall surface of the combustion chamber when the engine is shut down; calculating a preset throttle opening degree when the engine is stopped based on the oil film residual amount and the rotating speed of the engine; the engine is controlled to start to execute shutdown ventilation operation at the preset throttle opening degree; the air-fuel ratio of gas exhausted by the engine is continuously obtained in the shutdown ventilation operation; whether the air inflow of the engine reaches the air inflow needed in the engine shutdown process or not is judged based on the air-fuel ratio; and in response to the fact that the air inflow of the engine reaches the air inflow needed in the engine shutdown process, the engine is controlled to be shut down through the motor. Fuel oil in the combustion chamber is discharged through exhaust of the engine, and the compression ignition phenomenon during next-time starting is avoided.

The present application relates to an assembly method and an assembly tooling for an engine variable valve timing system. The assembly tooling includes: a fixed frame; a positioning shaft fixedly connected to the fixed frame. One end of the positioning shaft away from the fixed frame is provided with a first shaft section, a second shaft section and a third shaft section which are sequentially distributed in a stepped manner. The first shaft section is used for fitting with the inner diameter of the inner rotor, the third shaft section is used for fitting with the timing drive wheel, and the second shaft section is provided with a positioning pin hole for fitting with the pin shaft on the inner rotor; a positioning device coaxially arranged with the positioning shaft, which is used for sleeving the outer rotor on the outer peripheral side of the inner rotor and pressing the cover plate onto the outer rotor so that the threaded holes of the cover plate, the outer rotor and the timing drive wheel are aligned; a first jaw and a second jaw which are symmetrically arranged and connected to the fixed frame. The central axes of the first jaw and the second jaw are eccentrically arranged with respect to the central axis of the positioning shaft, and are used for clamping the timing drive wheel to move in the eccentric direction so as to control the phase of the radial runout of the phaser in a preset direction.

internal combustion engine (8) comprising a camshaft (1) which drives at least one inlet valve (5) with which a fluid inlet in a cylinder (9) of the internal combustion engine (8) can be controlled, - wherein the camshaft (1) comprises at least one cam (2), - wherein the cam (2) has at least a valve opening elevation (7) and a control projection (3,4), - wherein the valve opening lift (7) is arranged to open the inlet valve (5) to a maximum stroke, - wherein the inlet valve (5) is open at least during part of a compression movement of a piston (6) of the internal combustion engine (8) associated with the inlet valve (5) in order to decompress the cylinder (9), - wherein the inlet valve (5) can be controlled by the camshaft (1) via a variable valve timing system, and - wherein the variable valve control allows the valve lift of the inlet valve (5) to be adjusted, - wherein by adjusting the valve lift of the intake valve (5) the operation of the internal combustion engine (8) can be switched between depending on a speed of the internal combustion engine (8) ◯ an operation with early closing of the inlet valve (5) at high speeds, and ◯ an operation with late closing of the inlet valve (5) after the bottom dead center of the piston (6) at low speeds, - characterized by the fact that ◯ the operation with early closing of the inlet valve (5) before a bottom dead center of the piston (6) is adjustable by a small valve lift, and ◯ the operation with late closing of the inlet valve (5) is adjustable by a large valve lift.

The utility model relates to the technical field of marine engines, and discloses a variable valve timing and lifting device of a marine four-stroke engine, which comprises a rocker arm and a cam, a shaft hole connected with a fixed rotating shaft is arranged at one end of the rocker arm, a driving ring is arranged between the fixed rotating shaft and the rocker arm, and a step groove is arranged in the middle of the rocker arm. A step groove is formed in the rocker arm, a roller control arm is arranged in the step groove, a roller is arranged in the roller control arm, the roller control arm is connected with the driving ring, the driving ring can drive the roller control arm to move back and forth in the step groove, and the cam is located above the rocker arm and makes contact with the roller in the step groove of the rocker arm. The driving device is additionally arranged on the roller on the rocker arm of the valve mechanism of the four-stroke engine, so that the position of the roller relative to the cam is variable, the function that the phase of the valve mechanism of the engine is variable is achieved, the output characteristic of the engine can be effectively improved, the fuel economy is improved, and the system is simple and compact in structure and convenient to maintain.

Systems and methods for exhaust composition management during stochastic pre-ignition mitigation are provided. Combustion event data is received from at least one combustion event sensor associated with a plurality of cylinders. Each cylinder includes a combustion chamber, an intake valve, and an exhaust valve. Opening the intake valve allows air to flow from the intake manifold into the combustion chamber. Opening the exhaust valve allows air to flow from the combustion chamber to the exhaust manifold. When a determination is made that an SPI event has occurred in at least one of the cylinders based on the combustion event data, a command is issued to a variable valve timing (VVT) system to achieve a valve timing overlap for each of the plurality of cylinders during which intake valves and exhaust valves of the cylinders are simultaneously placed in open positions.

The application discloses a variable timing valve opening degree measurement method, device, storage medium and vehicle, and relates to the technical field of variable valve timing control, and can be used for measuring the opening degree of a variable timing valve. The method comprises the following steps: acquiring a camshaft signal wheel duty cycle signal of a camshaft signal wheel, and determining base tooth position information of the camshaft signal wheel according to the camshaft signal wheel duty cycle signal; acquiring crankshaft signal wheel sensor measurement information of a crankshaft signal wheel, and determining flag tooth position information of the crankshaft signal wheel according to the crankshaft signal wheel sensor measurement information; and determining the real-time opening degree of the variable timing valve according to the base tooth position information, the flag tooth position information and zero position information.

The embodiment of the present application provides a variable valve timing assembly and a vehicle, wherein the variable valve timing assembly includes: a camshaft, a timing pulley, a first cover plate, and a locking member disposed on the first cover plate; the timing pulley is sleeved on the camshaft and connected to the engine; the first cover plate is disposed on the timing pulley; the locking member includes an elastic member and a positioning pin, the first end of the elastic member is connected to the first cover plate, the second end of the elastic member is connected to the positioning pin, and the elastic member drives the positioning pin to move in an operating area, which is an area on the camshaft; a plurality of limiting holes are provided on the operating area, and when the positioning pin is located in at least one of the plurality of limiting holes, the camshaft and the timing pulley stop relative rotation. In this way, by changing the relative position between the positioning pin and the plurality of limiting holes in the operating area, multi-angle adjustment of the variable valve timing is achieved, thereby improving adjustment flexibility.

To improve startability of an engine regardless of a state of a lock pin in a variable valve train in an engine control device.SOLUTION: An engine control device 30 includes a setting part 31 and a control part 32. When the engine 1 is stopped, the setting unit 31 sets the flag to ON if the oil temperature of the engine oil that drives the variable valve mechanism 10 is equal to or lower than a predetermined temperature, and sets the flag to OFF if the oil temperature exceeds the predetermined temperature. At the start of the engine 1, the control unit 32 performs the normal control when the flag is off, and performs the scavenging control and the normal control when the flag is on. The normal control is a control for starting the engine 1 by cranking while performing both fuel injection and ignition. The scavenging control is control for scavenging the inside of the combustion chamber by cranking without performing both fuel injection and ignition.SELECTED DRAWING: Figure 1

A variable valve timing phaser comprises a stator part, a rotor and an outer cover plate, the stator part comprises a stator ring, an inner cover plate and a chain wheel, the inner cover plate is integrally connected to one side of the back face of the stator ring and extends to the inner side of the stator ring, and the chain wheel is integrally connected to one side of the back face of the stator ring and extends to the outer side of the stator ring. The outer cover plate is detachably connected to one side of the front face of the stator ring, and the rotor is rotatably installed in the stator ring and limited between the inner cover plate and the outer cover plate. According to the scheme, the inner cover plate, the chain wheel and the stator ring are designed to be integrally connected, so that a plurality of parts which are independently produced originally are combined together, and the production cost is greatly reduced; meanwhile, the inner cover plate and the chain wheel are integrally connected to one side of the back face of the stator ring, the inner cover plate can play a certain role in supporting and reinforcing the chain wheel mainly bearing loads, and the overall structural strength is better.

The invention relates to the technical field of engine control, and particularly discloses an evaluation method and device for variable valve timing of an engine, a storage medium and a vehicle. The evaluation method for the variable valve timing of the engine comprises the steps that multiple evaluation dimensions of the variable valve timing of the engine are obtained; establishing an analysis template and an evaluation standard of each evaluation dimension; determining a single evaluation score of each evaluation dimension according to the analysis template and the evaluation criteria; obtaining a weight coefficient of each single evaluation score; and determining the total evaluation score of the variable valve timing of the engine according to each single evaluation score and the corresponding weight coefficient, thereby improving the evaluation accuracy of the variable valve timing and saving human resources.

The present application relates to a kind of control method, device, vehicle and storage medium, wherein, control method includes: obtaining engine speed, engine actual load and the engine target load corresponding to set type;According to engine speed, engine actual load and engine target load, the target angle corresponding to the set type of variable valve timing mechanism is determined;According to target angle, the angle corresponding to the set type of variable valve timing mechanism is controlled.According to the above technical means, when engine target load is rapidly reduced and engine actual load is larger, the target angle corresponding to the set type of variable valve timing mechanism can be limited, so that the target angle corresponding to the set type is set to the angle that does not produce over-blast, thereby reducing the probability of over-blast occurrence, to protect engine, and better driving performance can be obtained.

To precisely identify an intake valve and an exhaust valve that generate noise.SOLUTION: A noise diagnostic system according to the invention is configured to: when noise is determined to be generated by a driven valve system of an internal combustion engine, determine, on the basis of information on a crank angle in a predetermined period, information on a valve lift timing of the internal combustion engine, amounts of change in opening / closing timings of a variable valve timing mechanism and a waveform of a recorded sound, whether or not at least one of opening / closing timings of an intake valve and an exhaust valve of each of air cylinders in the predetermined period is included within a predetermined timing range including timings of peaks of a waveform of the recorded sound: and, when the at least one of opening / closing timings of the intake valve and the exhaust valve of each of the air cylinders in the predetermined period is included within the predetermined timing range, diagnose that the noise is generated by an intake valve or exhaust valve of an air cylinder whose opening / closing timing is included in the predetermined timing range among the intake valves and exhaust valves of a plurality of air cylinders.SELECTED DRAWING: Figure 2

The utility model belongs to the technical field of engine oil control valves of variable valve timing systems, and particularly relates to a central control valve. The central control valve comprises a valve shell provided with a cavity; the valve sleeve assembly is arranged in the cavity and comprises a valve sleeve and an oil guide sleeve, the valve sleeve and the oil guide sleeve are provided with an oil inlet, a first oil outlet and a second oil outlet, and the oil inlet is located between the first oil outlet and the second oil outlet; and the valve element is movably arranged in the oil guide sleeve, and a check ring is arranged on the valve shell. One end of the valve sleeve abuts against the valve shell through the check ring, and the other end of the valve sleeve abuts against the valve shell through the valve seat and is provided with a channel and an oil passing hole. A metal spring seat is arranged in the channel, and the spring seat and the valve sleeve are formed in an injection molding mode. The valve element abuts against the check ring through the first spring. One end of the ball abuts against the spring seat through the second spring, and the other end of the ball abuts against the valve seat. Therefore, the problems that in the prior art, a control valve is complex to assemble and low in efficiency are solved.

Variable Valve Timing Clamp

A method (100) for controlling a boosted spark-ignition internal combustion engine (10), the engine comprising a heat exchanger mounted downstream of a compressor of a boosting system and a variable valve timing system (27) configured to control a valve lift (VVT) between an exhaust bottom dead center (exhaust BDC), a top dead center (TDC), and an intake bottom dead center (intake BDC), wherein:-the mass (Mwater) of the liquid water stored on the inner wall of the exchanger (26) is estimated in real time; -comparing the estimated mass (Mwater) with a threshold (S); and-initiating a purge of the cooler (26) when the estimated mass (Mwater) of water is greater than a threshold (S), causing an oscillation of the intake volumetric flow (Qvol) into the exchanger (26) between the nominal volumetric flow value (Qvolname) and the increased volumetric flow value (Qvol +).

The variable duration valve train controls the flow of air into the combustion chambers of the combustion engine. The variable duration valve train includes a drive cylinder structure, a stroke limit cylinder structure, an engine valve structure, a plurality of cams, and a working fluid. The engine valve structure attaches to the drive cylinder structure. The stroke limit cylinder structure forms a fluidic connection with the drive cylinder structure. The working fluid fills the stroke limit cylinder structure and the drive cylinder structure. The plurality of cams form mechanical linkages with the drive cylinder structure and the stroke limit cylinder structure. The working fluid and the plurality of cams limit the range of motion of the engine valve structure.

There is provided a variable valve timing system for an engine in which a cylinder head is fixed on a cylinder, and the cylinder head is suspended on a vehicle body frame, the variable valve timing system including: a variable valve device configured to change an opening and closing timing of a valve according to a hydraulic pressure; and an oil control valve. The vehicle body frame includes a main frame configured to laterally cover a rear side of the cylinder head and a down frame configured to laterally cover a front side of the cylinder head. In a side view of a vehicle, the oil control valve is detachably disposed on an outer surface of the engine below an area surrounded by the main frame, the down frame, and a lower surface of the cylinder head.

The application discloses an electro-hydraulic control variable valve timing and lift adjustment method and device, and belongs to the field of power machinery control. The application constructs a working mode suitable for the electro-hydraulic control variable valve timing and lift adjustment device, including a full lift mode, an early intake valve closing mode, a late intake valve opening mode and a multiple intake valve mode; the profile of a cam, the diameter of a driving receiving piston, the diameter of a high-pressure oil way and a solenoid valve are optimized; based on the working characteristics of a high-speed solenoid valve for controlling the on-off of an oil way, a solenoid valve current waveform and a power driving circuit are designed to realize the thermal protection and quick opening and closing of the solenoid valve; according to the requirements of different modes, corresponding control strategies are designed, a controller module judges the current cylinder number according to a camshaft signal and sends a control signal to a driving circuit according to a crankshaft signal to control the accurate opening and closing of the solenoid valve, so that the multi-mode adjustment of valve timing and lift is realized. The application has the advantages of high controllability and strong practicability and is suitable for the requirements of continuously adjusting the valve timing and lift of a high-power vehicle.

This invention discloses an unlocking control method for a center-lock variable valve timing system, comprising: S1: After obtaining an unlocking command and meeting the unlocking conditions, proceeding to S2; S2: Obtaining the current duty cycle, controlling the current duty cycle for time t1 in an open loop, and obtaining the current phase of the camshaft in real time. If the phase difference between the current phase and the initial phase is greater than or equal to a deviation threshold, unlocking is successful, and the current duty cycle is controlled in a closed loop to adjust the current phase to the target phase; otherwise, unlocking fails, proceeding to S3; S3: Adjusting the current duty cycle to the first duty cycle time t2; S4: Adjusting the current duty cycle for time t3 according to the oscillation-assisted unlocking rule, and obtaining the current phase in real time. If the phase difference is greater than or equal to the deviation threshold, unlocking is successful, and the current duty cycle is controlled in a closed loop to adjust the current phase to the target phase; otherwise, unlocking fails, and a fault code is reported. This method can shorten the unlocking time under normal conditions and reduce overshoot, thus reducing the phenomenon of failure to unlock.

The present disclosure discloses a phaser and an engine variable valve timing system, belonging to the field of engines. The phaser includes a stator and a rotor, and the rotor is rotatably located radially inside the stator; the rotor includes a plurality of blade portions, the stator is provided with a plurality of oil cavity portions, and the plurality of blade portions are respectively located in the plurality of oil cavity portions and divide each oil cavity portion into an advance cavity and a retard cavity that are circumferentially distributed; at least one of the plurality of blade portions is provided with an internal circulation oil circuit structure, and both ends of the internal circulation oil circuit structure are respectively communicated with the advance cavity and the retard cavity corresponding to the blade portion; the internal circulation oil circuit structure is configured such that the oil can flow from one of the advance cavity and the retard cavity that is in a contracted state toward the other that is in an expanded state. The phaser of the present disclosure can achieve stable oil pressure supply, small oil pressure fluctuation, small phase retraction, and increase the stability of phase adjustment.

If the intake valve closing timing during cranking is constant, it can easily lead to starting problems under low-temperature conditions, and conversely, knocking under high-temperature conditions. [Solution] The internal combustion engine is equipped with an electrically operated variable valve timing mechanism that changes the phase of the camshaft and the crankshaft that open and close the intake valves within a predetermined angular range. In its default state, the variable valve timing mechanism is set to a late closing setting where the intake valve closing timing IVC is relatively far behind bottom dead center BDC. During cranking, the target conversion angle of the variable valve timing mechanism is controlled according to the coolant temperature, such that the lower the coolant temperature, the closer the intake valve closing timing IVC is to bottom dead center BDC, increasing the amount of intake air in the cylinder.

A method (100) of controlling a supercharged spark ignition internal combustion engine (10) comprising a heat exchanger mounted downstream of a compressor of a supercharging system and a variable valve timing system (27) configured to control valve lift (VVT) between exhaust bottom dead centre (exhaust BDC), top dead centre (TDC) and intake bottom dead centre (intake BDC), wherein: - the mass (M_water) of liquid water stored in real time on the internal walls of the exchanger (26) is estimated; - the said estimated mass (M_water) is compared with a threshold value (S); and - the cooler purge (26) is activated when the water mass estimate (M_water) is greater than the threshold value (S), by generating oscillations of the intake air volumetric flow rate (Qvol) entering the exchanger (26) between a nominal volumetric flow rate value (Qvol_name) and an increased flow rate value (Qvol_+).