Gas time-sharing gas inlet system and method based on crankshaft synchronizing signal control

Abstract

The invention discloses a gas time-sharing gas inlet method based on crankshaft synchronizing signal control, which belongs to the technical field of internal combustion engines, and comprises a gas supply channel which is arranged independent of an air inlet channel and is used for guiding gas to a cylinder, and a gas control valve is arranged on the gas supply channel; the servo motor is connected with the gas control valve and used for driving the gas control valve to execute opening or closing action; the crankshaft position sensor is used for detecting the rotating angle of an engine crankshaft in real time and generating a crankshaft synchronizing signal; and the electronic control unit is electrically connected with the crankshaft position sensor and the servo motor, receives the crankshaft synchronizing signal, judges the real-time phase of the engine according to the crankshaft synchronizing signal, and controls the servo motor to drive the gas control valve in the air inlet stroke, so that the gas control valve is kept closed in the air valve overlapping stage of the air cylinder and is opened after the air valve overlapping stage is ended. The invention aims to fundamentally solve the problems of mixed gas escape and tempering in the valve overlap angle period, and meanwhile, the economical efficiency, the dynamic property and the emission level of the engine are improved.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine technology, and in particular to a time-sharing gas intake system and method based on crankshaft synchronization signal control. Background Technology

[0002] A four-stroke engine's working cycle includes four strokes: intake, compression, power, and exhaust. Its performance is closely related to the quality of the air-fuel mixture formed during the intake stroke. To improve exhaust efficiency, modern engines are generally designed with a valve overlap angle, meaning that the intake valve opens before the exhaust valve is fully closed at the beginning of the intake stroke. While this design helps to remove residual exhaust gases, it also presents two significant technical challenges: First, there's the issue of fuel escape (short circuit). During the valve overlap phase, negative pressure within the cylinder acts simultaneously on both the intake and exhaust manifolds. If the air-fuel mixture has already entered the cylinder at this time, some unburned mixture will be directly "short-circuited" out through the still-open exhaust valve. This not only wastes fuel (experiments show that at idle to medium speeds, the escape amount can reach 5%-8% of the total intake air volume), but also directly leads to an increase in the concentration of unburned hydrocarbons (HC) in the exhaust, making it difficult to meet increasingly stringent emission regulations (such as China VI and Euro VI standards).

[0003] Secondly, there is the safety hazard of backfire. During valve overlap, high-temperature exhaust gases (reaching 600-800℃) in the exhaust manifold may be drawn into the intake manifold. If a combustible mixture already exists in the intake manifold, these high-temperature exhaust gases can easily ignite it, causing backfire. The shock wave generated by backfire can damage components such as intake valves and intake manifolds, posing a serious safety hazard. Current technology typically addresses this by installing backfire preventers in the intake pipe, but this is a passive protection measure that cannot eliminate the cause and increases intake resistance.

[0004] To address the aforementioned issues, existing technologies primarily attempt to improve the technology in two ways: first, by optimizing the valve overlap angle parameters, but this sacrifices low-speed torque and exhaust efficiency, making it difficult to achieve both simultaneously; second, by employing variable intake manifolds or mechanical gas valves. The former can only regulate airflow and cannot achieve sequential separation of gas and air, while the latter, due to its reliance on camshaft drive, suffers from inherent defects such as low control precision (large opening error), sluggish response, and inability to dynamically adjust according to operating conditions, making it difficult to achieve high-precision sequential control. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a time-sharing intake system and method for gas based on crankshaft synchronization signal control, aiming to fundamentally solve the problems of mixture escape and backfire during valve overlap angle, while improving engine economy, power and emission levels.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A first aspect of the present invention provides a time-sharing gas intake system based on crankshaft synchronization signal control, comprising: A gas supply channel, set independently of the air intake channel, is used to guide gas to the cylinder, and a gas control valve is provided on the gas supply channel; A servo motor, connected to the gas control valve, is used to drive the gas control valve to perform opening or closing actions; Crankshaft position sensor, used to detect the rotation angle of the engine crankshaft in real time and generate crankshaft synchronization signal; The electronic control unit, electrically connected to the crankshaft position sensor and servo motor, is configured to: receive the crankshaft synchronization signal and determine the real-time phase of the engine accordingly; control the servo motor to drive the gas control valve during the intake stroke, so that the gas control valve remains closed during the valve overlap phase of the cylinder; and control the gas control valve to open after the valve overlap phase ends to supply gas into the cylinder.

[0007] As a further implementation, the servo motor is a high-response servo motor that can receive command signals from the electronic control unit and achieve high-precision phase matching with the crankshaft synchronization signal. It can convert electronic control commands into precise angle outputs, thereby driving the gas control valve to complete the opening and closing actions.

[0008] As a further implementation, the outlet of the gas supply passage is a gas intake port opened on the cylinder head, and the gas intake port is also located on the two air intake passages.

[0009] As a further implementation, the electronic control unit stores a control MAP based on engine speed and load calibration, which is used to determine the timing of crankshaft angle for controlling the opening and closing of the gas control valve for different operating conditions.

[0010] As a further implementation, the gas control valve is a rotary valve driven by a servo motor.

[0011] A second aspect of the present invention provides a time-sharing gas intake method based on crankshaft synchronization signal control, and a time-sharing gas intake system based on crankshaft synchronization signal control according to the first aspect of the present invention, comprising the following steps: At the beginning of the engine intake stroke, when the crankshaft rotates to the first predetermined angle, the control servo motor drives the gas control valve to close, and only air is injected into the cylinder for scavenging. When the crankshaft rotates to the second predetermined angle, the control servo motor drives the gas control valve to open, so that the gas is injected into the cylinder through the gas intake port. The fuel gas mixes with the air that follows in the cylinder to form a combustible mixture; Before the intake stroke ends, the gas control valve is closed to stop the gas supply.

[0012] As a further implementation, the first predetermined angle corresponds to the valve overlap phase when the intake valve is open and the exhaust valve is not yet fully closed.

[0013] As a further implementation, the second predetermined angle corresponds to the exhaust valve being completely closed or the effective flow area of ​​the exhaust valve being reduced to below a preset threshold.

[0014] As a further implementation method, the timing and duration of the gas control valve opening are dynamically determined by the electronic control unit based on the real-time received engine speed signal and load signal, by querying a pre-calibrated control MAP.

[0015] As a further implementation method, the valve overlap stage is determined based on the crankshaft synchronization signal.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention, a time-shaft intake system and method for fuel gas based on crankshaft synchronization signal control, creatively separates the timing of fuel gas supply from the valve overlap angle. During the high-risk period of valve overlap, the system injects only pure air into the cylinder, with no fuel gas components in the cylinder. This fundamentally eliminates the possibility of the fuel mixture escaping through a "short circuit" from the exhaust valve and completely eliminates the prerequisite for backfire caused by high-temperature exhaust gas igniting the fuel mixture. The system safety is thus substantially improved.

[0017] The present invention relates to a time-shaft intake system and method for gas based on crankshaft synchronization signal control, which avoids ineffective fuel loss during valve overlap and ensures that all supplied gas can effectively participate in combustion and work, directly improving fuel utilization and engine thermal efficiency, and significantly improving fuel economy.

[0018] The present invention relates to a time-shaft intake system and method for gas combustion based on crankshaft synchronization signal control, which effectively solves the problem of large amounts of unburned HC emissions caused by short-circuiting of the air-fuel mixture, achieving ultra-low emissions. The improvement in emissions during cold starts, idling, and low-speed conditions is particularly significant, making it easier for engines to meet current and future stringent environmental regulations.

[0019] The present invention relates to a time-shaft intake system and method for gas injection based on crankshaft synchronization signal control. This system uses the crankshaft synchronization signal as the control reference and combines it with a high-response servo motor (such as a servo motor) as the actuator, achieving millisecond-level precise closed-loop control of the gas injection start point and duration. Its control accuracy and dynamic response speed are far superior to traditional mechanical cam-driven methods, enabling flexible adaptation to various complex engine operating conditions.

[0020] The present invention relates to a time-shaft intake system and method for combustion gases based on crankshaft synchronization signal control. This system utilizes pure air for scavenging, which is more efficient than a combustible mixture in removing high-temperature residual exhaust gases from the cylinder, thus improving charging efficiency and creating conditions for increasing engine power and torque. Simultaneously, the turbulent mixing of combustion gases with air within the cylinder helps form a more uniform mixture, improving combustion quality.

[0021] The present invention relates to a time-shaft gas intake system and method based on crankshaft synchronization signal control, which does not require large-scale structural modifications to the engine body. It is mainly achieved by adding an independent gas passage and electronically controlled valve to the existing intake port layout. It is easy to integrate and modify on existing engine platforms, with relatively low implementation costs and a wide range of applications. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 This is a schematic diagram of the installation of the gas control valve and servo motor in the air intake duct of the present invention. Figure 2 This is a block diagram of the overall structure of the gas time-sharing intake system based on crankshaft synchronization signal control of the present invention; Figure 3 This is a schematic diagram of the control logic and timing of the gas time-sharing intake method based on crankshaft synchronization signal control according to the present invention.

[0024] The components are: 1. Cylinder head; 2. Cylinder wall; 3. Upper end face of piston; 4. First air intake port; 5. Second air intake port; 6. First gas intake port; 7. Second gas intake port; 8. Gas control valve; 9. Servo motor; 11. Electronic control unit; 12. Gas supply main pipe; 13. Crankshaft position sensor; 14. Crankshaft; 15. Connecting rod. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0028] Example 1 The primary objective of this invention is to provide a time-sharing gas supply system and method that physically separates the supply of air and gas in time and introduces a crankshaft synchronization signal as a control reference to ensure that only pure air enters the cylinder during the high-risk period of valve overlap, thereby completely eliminating fuel short circuit and backfire risk.

[0029] Another core objective of this invention is to achieve precise control of the gas injection start point and duration at the millisecond level by using crankshaft synchronization signals to control the actuators (such as high-response servo motors) in the gas passage, thereby adapting to various complex engine operating conditions.

[0030] A further objective of this invention is to improve the quality of the air-fuel mixture formation, reduce harmful emissions, and ultimately achieve a comprehensive improvement in engine economy, environmental friendliness, and safety through the aforementioned time-sharing supply and in-cylinder mixing method. The specific solution of this invention is as follows: like Figures 1 to 2 As shown, this embodiment provides a gas time-sharing intake system based on crankshaft synchronization signal control, mainly including: cylinder head 1, cylinder wall 2, piston, first air intake port 4, second air intake port 5, first gas intake port 6, second gas intake port 7, gas control valve 8, servo motor 9, electronic control unit 11, and crankshaft position sensor 13. In this embodiment, the servo motor 9 is a high-response servo motor capable of receiving command signals from the electronic control unit 11 and achieving high-precision phase matching with the crankshaft synchronization signal. It can convert electronic control commands into precise angle outputs, thereby driving the gas control valve 8 to complete the opening and closing actions.

[0031] The gas supply channel (including the first gas intake channel 6 and the second gas intake channel 7) is set independently of the air intake channel (including the first air intake channel 4 and the second air intake channel 5) and is used to guide the gas to the cylinder. A gas control valve 8 is provided on the gas supply channel. Servo motor 9 is connected to gas control valve 8 and is used to drive gas control valve 8 to perform opening or closing actions; Crankshaft position sensor 13 is used to detect the rotation angle of engine crankshaft 14 in real time and generate crankshaft synchronization signal; The electronic control unit 11, electrically connected to the crankshaft position sensor 13 and the servo motor 9, is configured to: receive the crankshaft synchronization signal and determine the real-time phase of the engine accordingly; control the servo motor 9 to drive the gas control valve 8 during the intake stroke, so that the gas control valve 8 remains closed during the valve overlap phase of the cylinder, and controls the gas control valve 8 to open after the valve overlap phase ends to supply gas into the cylinder.

[0032] A first gas intake duct 6 and a second gas intake duct 7 are respectively installed on the first air intake duct 4 and the second air intake duct 5. Gas is supplied to the first gas intake duct 6 and the second gas intake duct 7 by the gas supply manifold 12. The outlets of the first gas intake duct 6 and the second gas intake duct 7 are gas intake holes opened on the cylinder head 1, and these gas intake holes are also located on the two air intake ducts. The first gas intake duct 6 and the second gas intake duct 7 are connected to the gas supply manifold 12 through a gas control valve 8. A gas control valve 8 is installed on the servo motor 9. This valve is driven by the servo motor 9. In this system, the servo motor 9 and the gas control valve 8 are a direct-drive rotary valve structure. The output shaft of the servo motor 9 is directly rigidly connected to the valve stem of the rotary valve core (using a ball valve). The rotational angular displacement of the motor can be directly converted into the opening and closing action of the valve core.

[0033] A crankshaft position sensor 13 is mounted near the engine crankshaft 14 to monitor the rotational position of the crankshaft 14 in real time and generate a crankshaft synchronization signal. This signal is transmitted to the electronic control unit 11 (ECU) in real time.

[0034] The electronic control unit 11 internally stores a control map calibrated based on engine speed and load, used to determine the timing of crankshaft angle control for opening and closing the gas control valve under different operating conditions. During operation, the ECU 11 continuously receives crankshaft synchronization signals and uses this to determine the real-time phase of the engine. When the intake stroke begins and the crankshaft angle reaches the intake valve start point, the ECU 11 sends a command to the servo motor 9 to keep the gas control valve 8 closed. At this time, only pure air enters the cylinder through the air intake passage 4 and the gas intake passage 5, performing the scavenging function.

[0035] As crankshaft 14 continues to rotate until the exhaust valve closes, ECU 11 immediately sends an opening command to servo motor 9. Servo motor 9 responds quickly, driving gas control valve 8 to open, injecting gas into the cylinder and mixing it with the subsequently entering air. Until the end of the intake stroke, when crankshaft 14 reaches the point where the intake valve closes, ECU 11 again sends a command to close gas control valve 8, completing one gas supply cycle.

[0036] The present invention relates to a time-shaft intake system for gas based on crankshaft synchronization signal control, which is particularly suitable for four-stroke engines. It can achieve precise control of the gas intake timing through crankshaft synchronization signal, and is applicable to various fuel types such as gasoline, natural gas, and liquefied gas. It can be widely used in power equipment such as automobiles, construction machinery, and generator sets.

[0037] Example 2 like Figure 3 As shown, this embodiment provides a time-sharing gas intake method based on crankshaft synchronization signal control, and a time-sharing gas intake system based on crankshaft synchronization signal control according to Embodiment 1, including the following steps: At the beginning of the engine intake stroke, when the crankshaft rotates to the first predetermined angle, the control servo motor drives the gas control valve to close, and only air is injected into the cylinder for scavenging. When the crankshaft rotates to the second predetermined angle, the control servo motor drives the gas control valve to open, so that the gas is injected into the cylinder through the gas intake port. The fuel gas mixes with the air that follows in the cylinder to form a combustible mixture; Before the intake stroke ends, the gas control valve is closed to stop the gas supply.

[0038] The first predetermined angle corresponds to the valve overlap phase when the intake valve is open but the exhaust valve is not yet fully closed. The second predetermined angle corresponds to when the exhaust valve is fully closed or the effective flow area of ​​the exhaust valve has decreased to below a preset threshold. The timing and duration of the gas control valve opening are dynamically determined by the electronic control unit based on the real-time received engine speed and load signals, by querying a pre-calibrated control MAP. The entry into the valve overlap phase is determined based on the crankshaft synchronization signal.

[0039] The first and second predetermined angles correspond to the opening / closing moments of the intake / exhaust valves. This moment is the angle (CAD) corresponding to the crankshaft rotation angle. The first and second predetermined angles are based on the piston's top dead center (TDC) as the 0-degree reference.

[0040] The specific steps are as follows: Pure air scavenging (intake stroke start) stage: The piston descends, and the intake and exhaust valves open simultaneously due to the valve overlap angle. At this time, the ECU, based on the received crankshaft synchronization signal, controls the servo motor to keep the gas control valve closed. Pure air is only introduced into the cylinder through the air intake manifold. This fresh air forces residual exhaust gases out of the exhaust valve. Since there is no combustion gas in the cylinder at this time, fuel short-circuiting and backfire are completely avoided.

[0041] Gas injection phase: When the crankshaft position sensor detects that the crankshaft has rotated to the second predetermined angle (this angle is calibrated to ensure that the exhaust valve is basically closed or the effective flow area has been significantly reduced), the ECU immediately sends a high-precision opening command signal to the servo motor. The servo motor quickly moves to drive the gas control valve to open, allowing gas to be injected into the cylinder through the gas intake port.

[0042] Mixture formation stage: The air that enters later and the injected combustion gas are mixed in a turbulent flow in the cylinder to form a uniform combustible mixture.

[0043] End of intake stroke: As the piston approaches bottom dead center, the intake valve closes, and the ECU, based on the crankshaft synchronization signal, instructs the servo motor to drive the gas control valve to close, stopping the gas supply.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0045] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A gas split-time intake system based on control of a crankshaft synchronous signal, characterized by, The application relates to a gas split-time intake system based on a crankshaft synchronous signal control, comprising the following steps: a gas supply channel is arranged independently of the air intake channel and is used for guiding gas to the cylinder, and a gas control valve is arranged on the gas supply channel; a servo motor is connected with the gas control valve and is used for driving the gas control valve to perform opening or closing actions; a crankshaft position sensor is used for detecting the rotating angle of the engine crankshaft in real time and generating a crankshaft synchronous signal; an electronic control unit is electrically connected with the crankshaft position sensor and the servo motor and is configured to receive the crankshaft synchronous signal and judge the real-time phase of the engine, control the servo motor to drive the gas control valve in the air intake stroke, keep the gas control valve closed in the valve overlap stage of the cylinder, and control the gas control valve to open to supply gas into the cylinder after the valve overlap stage ends.

2. A split-cycle gas engine system as claimed in claim 1, wherein, The servo motor is a high-response servo motor capable of receiving an instruction signal of the electronic control unit and realizing high-precision phase matching with the crankshaft synchronous signal, which can convert the electric control instruction into an accurate angle output to drive the gas control valve to complete the opening and closing actions.

3. A split-cycle gas engine system as claimed in claim 1, wherein, The outlet of the gas supply channel is a gas intake hole arranged on the cylinder head, and the gas intake hole is also located on the two air intake channels.

4. A split-cycle gas engine system as claimed in claim 1, wherein, The electronic control unit internally stores a control MAP graph calibrated based on the engine rotating speed and load, which is used for determining the crankshaft rotating angle timing of controlling the gas control valve to open and close under different working conditions.

5. A split-cycle gas engine system as defined in claim 1, wherein, The gas control valve is a rotary valve driven by the servo motor.

6. A gas split-time intake method based on a crankshaft synchronous signal control, characterized by, The application discloses a gas split-time intake system based on a crankshaft synchronous signal control, comprising the following steps: in the starting stage of the engine air intake stroke, when the crankshaft rotates to a first predetermined angle, the servo motor is controlled to drive the gas control valve to close, and only air is filled into the cylinder for scavenging; when the crankshaft rotates to a second predetermined angle, the servo motor is controlled to drive the gas control valve to open, so that gas is injected into the cylinder through the gas intake hole; the gas mixes with the subsequent entering air in the cylinder to form combustible mixed gas; before the end of the air intake stroke, the gas control valve is controlled to close to stop the gas supply.

7. A gas split-cycle method of admission based on the control of the crankshaft synchronisation signal as claimed in claim 6, characterised in that, The first predetermined angle corresponds to the valve overlap stage in which the intake valve is opened and the exhaust valve has not been completely closed.

8. A gas split admission method based on crankshaft synchronous signal control as claimed in claim 6, characterized in that, The second predetermined angle corresponds to the exhaust valve being completely closed or the effective flow area of the exhaust valve being reduced to below a preset threshold.

9. A gas split-cycle time admission method based on crankshaft synchronous signal control as defined in claim 6, characterized in that, The timing and duration of the opening of the gas control valve are dynamically determined by the electronic control unit according to the real-time received engine rotating speed signal and load signal, and the control MAP graph is queried.

10. A gas split admission method based on crankshaft synchronous signal control as claimed in claim 7, characterized in that, The entering valve overlap stage is judged based on the crankshaft synchronous signal.

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