Engine control method and engine

Abstract

The application relates to the technical field of engines, and discloses an engine control method and an engine. The engine control method comprises the following steps: when the engine is in a first operating condition, determining a first fuel injection amount injected into a tangential air inlet, a second fuel injection amount injected into a spiral air inlet, a first time period for injecting fuel into the tangential air inlet, and a second time period for injecting fuel into the spiral air inlet according to an air intake flow of an air intake manifold, an engine rotating speed and an engine torque; injecting the first fuel injection amount into the tangential air inlet in the first time period, and injecting the second fuel injection amount into the spiral air inlet in the second time period; and the first fuel injection amount is greater than the second fuel injection amount. The engine using the engine control method can effectively relieve the phenomenon that fuel is prone to colliding with the wall and causing wall attachment due to the mismatch between the fuel injection amount and the air intake flow on the basis of ensuring the charging efficiency, and can effectively improve the atomization effect of the fuel and the mixing effect after the fuel flows into the combustion chamber.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more particularly to engine control methods and engines. Background Technology

[0002] Replacing traditional fuels such as diesel and gasoline with methanol can significantly reduce engine emissions of nitrogen oxides and particulate matter. Studies have shown that the key factors affecting the methanol substitution rate and methanol-to-fuel ratio are the atomization effect of methanol in the intake manifold and the mixing state of methanol after it flows into the cylinder. Regarding the atomization effect of methanol in the intake manifold, when methanol is injected at a high injection volume, it is easy for methanol to collide with the wall of the intake manifold, resulting in some methanol adhering to the wall of the intake manifold in liquid form, which affects the breakdown, atomization and transport of methanol in the intake manifold with the intake airflow.

[0003] Currently, methanol engines in related technologies typically have one or two intake ports. To alleviate the phenomenon of methanol adhering to the walls of the intake ports in liquid form, the injection volume and injection pressure of the injector into the intake ports are usually adjusted according to the engine operating conditions so that the methanol spray can be roughly in the central area of ​​the intake ports. However, this will cause a mismatch between the methanol injection volume and the intake flow rate, which will affect the engine's working performance. Moreover, the effect of alleviating the methanol adhesion phenomenon still needs to be further improved. Summary of the Invention

[0004] The purpose of this invention is to provide an engine control method and an engine to solve the aforementioned problems existing in engines in the related art.

[0005] On one hand, the present invention provides an engine control method, wherein the cylinder head of the engine is provided with mutually independent tangential intake passages and helical intake passages, one end of each of the tangential intake passages and one end of each of the helical intake passages are connected to the engine's intake manifold, and the other ends of each of the tangential intake passages and the helical intake passages are connected to the engine's combustion chamber; the engine control method includes:

[0006] When the engine is in the first operating condition, the fuel injection parameters are determined based on the intake flow rate of the intake manifold, the engine speed and the engine torque. The fuel injection parameters include a first amount of fuel injected into the tangential intake manifold, a second amount of fuel injected into the spiral intake manifold, a first time period for fuel injection into the tangential intake manifold, and a second time period for fuel injection into the spiral intake manifold.

[0007] During the first time period, the first amount of fuel is injected into the tangential intake, and during the second time period, the second amount of fuel is injected into the spiral intake; the first amount of fuel is greater than the second amount of fuel.

[0008] As an alternative to the above engine control method, the crankshaft angle corresponding to the start time of the first time period is the first crankshaft angle, and the crankshaft angle corresponding to the start time of the second time period is the second crankshaft angle, wherein the first crankshaft angle is smaller than the second crankshaft angle.

[0009] As an alternative to the above-mentioned engine control method, the absolute value of the difference between the first crankshaft angle and the second crankshaft angle ranges from 30°CA to 50°CA.

[0010] As an optional solution to the above engine control method, the specific steps for determining the first and second injection quantities based on the intake manifold flow rate, engine speed, and engine torque include:

[0011] The total amount of the first fuel injection is determined based on the current intake airflow.

[0012] The first fuel injection percentage of the first fuel injection quantity to the first total fuel injection quantity and the second fuel injection percentage of the second fuel injection quantity to the first total fuel injection quantity are determined based on the current engine speed and the current engine torque.

[0013] The first fuel injection quantity and the second fuel injection quantity are calculated based on the first total fuel injection quantity, the first fuel injection percentage, and the second fuel injection percentage.

[0014] As an optional solution to the above engine control method, the top surface of the piston of the engine is provided with a combustion chamber recess, the top surface is perpendicular to the axial direction of the piston, and the inner peripheral wall and the inner bottom wall of the combustion chamber recess are perpendicularly connected; the first fuel injection ratio is greater than 50% and less than 65%, and the second fuel injection ratio is greater than 35% and less than 50%.

[0015] As an optional embodiment of the above-mentioned engine control method, the engine control method further includes:

[0016] When the engine is in the first operating condition, the cylinder pressure of the engine is acquired in real time;

[0017] Determine whether the cylinder pressure is within the range of the first cylinder pressure;

[0018] If the cylinder pressure is not within the first cylinder pressure range, then during the next injection, both the first time period and the second time period remain unchanged, and the first fuel injection ratio and the second fuel injection ratio are adjusted, or the first fuel injection total amount is adjusted, while the first fuel injection total amount remains unchanged.

[0019] As an optional solution of the above engine control method, if the cylinder pressure is greater than the maximum value of the first cylinder pressure range, then during the next injection, both the first time period and the second time period remain unchanged, and it is determined whether the first fuel injection ratio minus A% is within the first preset ratio range, and whether the second fuel injection ratio plus B% is within the second preset ratio range.

[0020] If the determined first fuel injection percentage minus A% is within the first preset percentage range, and the determined second fuel injection percentage plus B% is within the second preset percentage range, then the adjusted first fuel injection percentage for the next injection into the tangential intake duct is equal to the determined first fuel injection percentage minus A%, and the adjusted second fuel injection percentage for the next injection into the spiral intake duct is equal to the determined second fuel injection percentage plus B%.

[0021] Where A is a positive number greater than zero, and B is a positive number greater than zero.

[0022] As an optional solution to the above engine control method, if the first fuel injection ratio minus A% is not within the first preset ratio range, and / or the second fuel injection ratio plus B% is not within the second preset ratio range, then it is determined whether the first fuel injection total minus C is less than the first minimum limit fuel injection total.

[0023] If the first fuel injection total amount determined this time minus C is greater than or equal to the first minimum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to be equal to the first fuel injection total amount determined this time minus C.

[0024] If the first fuel injection total amount determined this time minus C is less than the first minimum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to equal the first minimum limit fuel injection total amount.

[0025] Wherein, C is the first adjustment step size of the first total fuel injection.

[0026] As an optional solution of the above engine control method, if the cylinder pressure is less than the minimum value of the first cylinder pressure range, then during the next injection, both the first time period and the second time period remain unchanged, and it is determined whether the first fuel injection ratio plus D% determined this time is within the first preset ratio range, and whether the second fuel injection ratio minus E% determined this time is within the second preset ratio range.

[0027] If the first fuel injection percentage plus D% is within the first preset percentage range, and the second fuel injection percentage minus E% is within the second preset percentage range, then the first fuel injection percentage to be injected into the tangential intake duct next time will be adjusted as follows: first fuel injection percentage plus D%; second fuel injection percentage to be injected into the spiral intake duct next time will be adjusted as follows: second fuel injection percentage minus E%.

[0028] Where D is a positive number greater than zero, and E is a positive number greater than zero.

[0029] As an alternative to the above engine control method, if the first fuel injection ratio plus D% determined this time is not within the first preset ratio range, and / or the second fuel injection ratio minus E% determined this time is not within the second preset ratio range, then it is determined whether the first fuel injection total plus F determined this time is greater than the first maximum limit fuel injection total.

[0030] If the first fuel injection total amount determined this time plus F is greater than or equal to the first maximum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to equal the first maximum limit fuel injection total amount.

[0031] If the total first fuel injection amount determined this time plus F is less than the first maximum limit fuel injection amount, then the total first fuel injection amount for the next time will be adjusted to be the total first fuel injection amount determined this time plus F.

[0032] Where F is the second adjustment step of the first total fuel injection.

[0033] As an alternative to the above engine control method, when the engine is in the second operating condition, the total amount of the second fuel injection to be injected into the tangential intake port is determined based on the intake flow rate of the intake manifold, and the third time period for injection into the tangential intake port is determined based on the engine speed and engine torque.

[0034] During the third time period, the total amount of the second fuel injection is injected into the tangential intake duct;

[0035] In the first operating condition, the engine load is greater than the engine load in the second operating condition.

[0036] As an optional embodiment of the above-mentioned engine control method, the engine control method further includes:

[0037] When the engine is in the second operating condition, the cylinder pressure of the engine is acquired in real time;

[0038] Determine whether the cylinder pressure is within the range of the second cylinder pressure;

[0039] If the cylinder pressure is not within the range of the second cylinder pressure, then during the next combustion, the third time period remains unchanged, and the total amount of the second fuel injection is adjusted.

[0040] As an alternative to the above engine control method, if the cylinder pressure is greater than the maximum value of the second cylinder pressure range, then during the next injection, the third time period remains unchanged, and it is determined whether the second fuel injection total amount minus G is less than the second minimum limit fuel injection total amount.

[0041] If the total amount of the second fuel injection determined this time minus G is greater than or equal to the total amount of the second minimum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to be the total amount of the second fuel injection determined this time minus G.

[0042] If the total amount of the second fuel injection determined this time minus G is less than the total amount of the second minimum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to equal the total amount of the second minimum limit fuel injection.

[0043] Wherein, G is the first adjustment step of the second total fuel injection quantity.

[0044] As an alternative to the above engine control method, if the cylinder pressure is less than the minimum value of the second cylinder pressure range, then during the next injection, the third time period remains unchanged, and it is determined whether the second fuel injection total amount plus H determined this time is greater than the second maximum limit fuel injection total amount.

[0045] If the total amount of the second fuel injection determined this time plus H is greater than or equal to the total amount of the second maximum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to the total amount of the second maximum limit fuel injection.

[0046] If the total amount of the second fuel injection determined this time plus H is less than the total amount of the second maximum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to be equal to the total amount of the second fuel injection determined this time plus H.

[0047] Wherein, H is the second adjustment step size of the second total fuel injection.

[0048] The engine control method provided by this invention has at least the following beneficial effects:

[0049] Because engines require larger quantities of both fuel and air during high-load operation, the system controls fuel injection during this period based on intake manifold flow rate, engine speed, and engine torque. A first-time period involves injecting a first-quantity fuel into the tangential intake manifold, and a second-time period involves injecting a second-quantity fuel into the spiral intake manifold. Under this operating condition, each injection is divided into two parts: the first part is injected into the tangential intake manifold, mixes with the air there, and flows into the engine's combustion chamber; the second part is injected into the spiral intake manifold, mixes with the air there, and flows into the engine's combustion chamber. Compared to related technologies, the fuel injected into the tangential intake manifold... The amount of fuel injected into the spiral intake is less than the total amount of fuel injected, which effectively alleviates the problem of fuel adhering to the walls caused by the mismatch between the fuel injection amount and the intake flow rate due to the large amount of fuel injected into one intake in related technologies. It can effectively improve the atomization effect of the fuel injected into the tangential intake and the spiral intake. In addition, by setting the first amount of fuel injected into the tangential intake to be greater than the second amount of fuel injected into the spiral intake, the characteristics of the tangential intake, such as large flow rate, low flow resistance, and high charging efficiency, as well as the characteristics of the spiral intake, such as the ability to form strong vortices, are effectively combined. Specifically, the tangential intake has the characteristics of large flow rate, low flow resistance and high charging efficiency, which can efficiently deliver the air-fuel mixture to the combustion chamber of the engine. Therefore, while ensuring charging efficiency, it can further alleviate the phenomenon of fuel adhering to the walls in the tangential intake caused by the mismatch between fuel injection amount and intake flow rate. The spiral intake has the characteristic of forming a strong vortex, which can effectively improve the mixing effect of air and fuel after entering the combustion chamber in the spiral intake. Moreover, since the amount of fuel injected into the spiral intake is smaller, it can also further effectively alleviate the phenomenon of fuel adhering to the walls in the spiral intake caused by the mismatch between fuel injection amount and intake flow rate.

[0050] On the other hand, the present invention provides an engine in which the cylinder head is provided with an independent tangential intake passage and a spiral intake passage. One end of the tangential intake passage and one end of the spiral intake passage are connected to the intake manifold of the engine, and the other end of the tangential intake passage and the other end of the spiral intake passage are connected to the combustion chamber of the engine. The engine is used to implement the above-described engine control method.

[0051] The engine provided by this invention has at least the following beneficial effects:

[0052] By employing the aforementioned engine control method, this engine can effectively mitigate the phenomenon of fuel adhering to the combustion chamber walls due to the mismatch between fuel injection quantity and intake air flow while ensuring charging efficiency during high-load operation. It can also effectively improve fuel atomization and enhance the mixing effect of air and fuel after they flow into the combustion chamber. Attached Figure Description

[0053] Figure 1 A schematic diagram of the cylinder head's air passage from a first perspective, provided in an embodiment of the present invention;

[0054] Figure 2 A schematic diagram of the cylinder head's air passage from a second perspective, provided in an embodiment of the present invention;

[0055] Figure 3 A schematic diagram of the cylinder head's air passage from a third-view perspective, provided in an embodiment of the present invention;

[0056] Figure 4 This is a first flowchart of an engine control method provided in an embodiment of the present invention;

[0057] Figure 5 This is a second flowchart of the engine control method provided in an embodiment of the present invention;

[0058] Figure 6 A line graph comparing the amount of wall adhesion before and after optimization, provided for an embodiment of the present invention;

[0059] Figure 7 A bar chart comparing the amount of gaseous methanol before and after optimization, provided for an embodiment of the present invention.

[0060] In the picture:

[0061] 1. Tangential intake duct; 2. Spiral intake duct; 3. First mounting hole; 4. Second mounting hole; 5. Exhaust duct. Detailed Implementation

[0062] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0065] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0066] This invention provides an engine, such as Figure 1-3 As shown, the engine cylinder head has independent tangential intake manifold 1 and spiral intake manifold 2. One end of tangential intake manifold 1 and one end of spiral intake manifold 2 are connected to the engine's intake manifold, and the other end of tangential intake manifold 1 and spiral intake manifold 2 are connected to the engine's combustion chamber. The air-fuel mixture can flow into the engine's combustion chamber through tangential intake manifold 1 and spiral intake manifold 2.

[0067] Specifically, when air enters the engine, it is divided into two parts. The first part flows into the engine's combustion chamber through the tangential intake duct 1, and the second part simultaneously flows into the engine's combustion chamber through the spiral intake duct 2. More specifically, the tangential intake duct 1 features high flow rate, low flow resistance, and high charging efficiency, while the spiral intake duct 2 is capable of generating strong vortices. The specific structures of the tangential intake duct 1 and the spiral intake duct 2 are existing technologies and will not be described in detail here.

[0068] In this embodiment, for example, one end of the tangential intake duct 1 and one end of the spiral intake duct 2 are directly connected to the intake manifold, which is connected to the main intake pipe. Air flows from the main intake pipe to the intake manifold, and then is divided into two parts that flow into the combustion chamber of the engine through the tangential intake duct 1 and the spiral intake duct 2, respectively.

[0069] In this embodiment, the engine further includes a first injector and a second injector disposed on the cylinder head. The injection end of the first injector extends into the tangential intake manifold 1 for injecting combustion into the tangential intake manifold 1, and the injection end of the second injector extends into the spiral intake manifold 2 for injecting combustion into the spiral intake manifold 2. Further, in this embodiment, as... Figure 3 As shown, the cylinder head is provided with a first mounting hole 3 communicating with the tangential intake passage 1 and a second mounting hole 4 communicating with the spiral intake passage 2; the first injector is mounted on the cylinder head through the first mounting hole 3 and the injection end of the first injector extends into the tangential intake passage 1; the second injector is mounted on the cylinder head through the second mounting hole 4 and the injection end of the second injector extends into the spiral intake passage 2.

[0070] Furthermore, in this embodiment, the fuel injected by the first injector and the second injector is methanol, meaning the engine in this embodiment is a methanol engine. In other embodiments, the fuel injected by the first injector and the second injector may also be clean fuels such as liquid ammonia or methane.

[0071] Optionally, the combustion direction of the first injector is at an acute angle to the flow direction of the gas through the tangential intake duct 1. This allows the fuel injected by the first injector into the tangential intake duct 1 to mix better with the air inside the tangential intake duct 1, improving the mixing effect. Secondly, it effectively mitigates the wall adhesion phenomenon caused by the fuel injected by the first injector colliding with the wall of the tangential intake duct 1, thereby effectively improving the atomization effect of the fuel injected by the first injector. It is understood that the angle between the combustion direction of the first injector and the flow direction of the gas through the tangential intake duct 1 can be set to 45°, 50°, or 60°, etc., according to actual operating conditions.

[0072] Optionally, the combustion direction of the second injector is at an acute angle to the flow direction of the gas through the spiral intake duct 2. This allows the fuel injected by the second injector into the spiral intake duct 2 to mix better with the air inside the spiral intake duct 2, improving the mixing effect. Secondly, it effectively mitigates the wall adhesion phenomenon caused by the fuel injected by the second injector colliding with the wall of the spiral intake duct 2, thereby effectively improving the atomization effect of the fuel injected by the second injector. It is understood that the angle between the combustion direction of the second injector and the flow direction of the gas through the spiral intake duct 2 can be set to 45°, 50°, or 60°, etc., according to actual operating conditions.

[0073] Specifically, such as Figure 1-3 As shown, the cylinder head also has an exhaust passage 5, which is used for exhaust. The air passages on the cylinder head include a tangential intake passage 1, a spiral intake passage 2, and an exhaust passage 5. The intake passage includes the tangential intake passage 1 and the spiral intake passage 2. The specific structure of the exhaust passage 5 is prior art and will not be described in detail here.

[0074] Since the tangential intake duct 1, the spiral intake duct 2, and the exhaust duct 5 are all virtual structures... Figure 1-3 The tangential air intake 1 indicated in the text is used to represent the outline of the tangential air intake 1. Figure 1-3 The spiral air intake 2 shown in the text is used to illustrate the outline of the spiral air intake 2. Figure 1-3 The exhaust duct 5 indicated is used to represent the outline of the exhaust duct 5. Furthermore, since the first mounting hole 3 communicates with the tangential intake duct 1 and the second mounting hole 4 communicates with the spiral intake duct 2, Figure 3 The first mounting hole 3 indicated in the text is used to show the outline of the first mounting hole 3. Figure 3 The second mounting hole 4 indicated in the text is used to show the outline of the second mounting hole 4.

[0075] Specifically, the engine also includes a piston, the top surface of which has a combustion chamber recess, forming a combustion chamber between the piston and the cylinder head. The combustion chamber is used to burn fuel and generate high-temperature, high-pressure gas.

[0076] In this embodiment, the top surface of the piston is perpendicular to the piston's axis, and the inner peripheral wall and the inner bottom wall of the combustion chamber recess are vertically connected. Furthermore, the inner peripheral wall and the inner bottom wall are connected by a curved chamfered surface. It is understood that the combustion chamber recess is approximately cylindrical in shape. In other embodiments, the inner peripheral wall and the inner bottom wall of the combustion chamber recess may also be directly vertically connected. It is understood that the specific shape of the combustion chamber recess can be adjusted according to actual operating conditions.

[0077] In this embodiment, an intake flow sensor is provided on the intake manifold to monitor the intake flow rate of the intake manifold.

[0078] In this embodiment, a pressure sensor electrically connected to the controller is also provided on the cylinder head. The pressure sensor is used to monitor cylinder pressure. Cylinder pressure refers to the pressure inside the combustion chamber when the piston of the engine moves to the top dead center of the compression stroke.

[0079] More specifically, the intake air flow sensor, pressure sensor, first injector, and second injector are all electrically connected to the controller. The controller can receive the intake air flow monitored by the intake air flow sensor and the cylinder pressure monitored by the pressure sensor, and the controller can control the first and second injectors to inject fuel. In this embodiment, the controller is a vehicle controller.

[0080] This invention also provides an engine control method, such as... Figure 4 and Figure 5 As shown, the engine control method includes:

[0081] S100: During engine operation, the engine's operating condition is determined in real time. This operating condition includes a first operating condition and a second operating condition; the engine load is greater in the first operating condition than in the second operating condition. Specifically, the first operating condition refers to the engine's high-load operating condition, and the second operating condition refers to the engine's low-load operating condition.

[0082] Specifically, when the engine load is greater than or equal to a preset load percentage, the engine operates under a high load condition, i.e., the engine is in the first operating condition; when the engine load is less than the preset load percentage, the engine operates under a low load condition, i.e., the engine is in the second operating condition. In this embodiment, the preset load percentage is set to 30% for example. The preset load percentage is an empirical value obtained from a large number of previous tests.

[0083] Specifically, engine load refers to the ratio of the engine's actual output to its maximum output at a specific engine speed, where output refers to power or torque, etc. Engine load percentage refers to the ratio of the engine's actual output torque to its maximum torque when the engine throttle is fully open at a specific engine speed, expressed as a percentage.

[0084] If the engine is in the first operating condition, then steps S200 and S300 are executed.

[0085] S200. The fuel injection parameters are determined based on the intake flow rate of the intake manifold, the engine speed and the engine torque. The fuel injection parameters include the first amount of fuel injected into the tangential intake duct 1, the second amount of fuel injected into the spiral intake duct 2, the first time period of fuel injection into the tangential intake duct 1 and the second time period of fuel injection into the spiral intake duct 2.

[0086] S300: During the first time period, fuel of a first amount is injected into the tangential intake 1, and fuel of a second amount is injected into the spiral intake 2 during the second time period; the first amount of fuel is greater than the second amount of fuel.

[0087] If the engine is in the second operating condition, then steps S400 and S500 are executed.

[0088] S400: Determine the total amount of the second fuel injection into the tangential intake duct 1 based on the intake flow rate of the intake manifold, and determine the third time period for the fuel injection into the tangential intake duct 1 based on the engine speed and engine torque.

[0089] S500, during the third time period, injects the second fuel injection total amount into the tangential intake duct 1.

[0090] Specifically, when the engine is running at low load, the throttle opening is small, the air intake is small, and the amount of fuel to be injected is small. When the engine is running at high load, the throttle opening is large, the air intake is large, and the amount of fuel to be injected is large.

[0091] Since the engine requires less fuel and air when operating at low load, the amount of fuel injected into the tangential intake duct 1 is controlled only during the third time period based on the intake flow rate of the intake manifold, engine speed, and engine torque. This ensures that the amount of fuel injected meets the engine's operating requirements while avoiding the additional energy consumption caused by simultaneously activating the first and second injectors. Furthermore, because the tangential intake duct 1 has the characteristics of high flow rate, low flow resistance, and high charging efficiency, the air in the tangential intake duct 1 can mix with the fuel injected by the first injector and carry the fuel injected by the first injector into the engine's combustion chamber quickly and efficiently. This effectively alleviates the phenomenon of fuel adhering to the walls of the tangential intake duct 1 while ensuring charging efficiency.

[0092] Because the engine requires a large amount of fuel and air during high-load operation, the first amount of fuel is injected into the tangential intake manifold 1 during a first time period, and the second amount of fuel is injected into the spiral intake manifold 2 during a second time period, based on the intake flow rate of the intake manifold, engine speed, and engine torque. Under this operating condition, the fuel is divided into two parts for each injection. The first part of the fuel is injected into the tangential intake manifold 1 through the first injector, mixes with the air therein, and flows into the engine's combustion chamber. The second part of the fuel is injected into the spiral intake manifold 2 through the second injector, mixes with the air therein, and flows into the engine's combustion chamber. Compared to related technologies, this embodiment... The amount of fuel injected into the tangential intake duct 1 is less than the total combustion amount, and the amount of fuel injected into the spiral intake duct 2 is also less than the total combustion amount. This effectively alleviates the problem of fuel adhering to the walls caused by the mismatch between the fuel injection amount and the intake flow rate due to the large amount of fuel injected into one intake duct in related technologies. It also effectively improves the atomization effect of the fuel injected into the tangential intake duct 1 and the spiral intake duct 2. In addition, by setting the first combustion amount injected into the tangential intake duct 1 to be greater than the second combustion amount injected into the spiral intake duct 2, the characteristics of the tangential intake duct 1 (large flow rate, low flow resistance, and high charging efficiency) and the characteristics of the spiral intake duct 2 (able to form a strong vortex) are effectively combined. Specifically, the tangential intake duct 1 features high flow rate, low flow resistance, and high charging efficiency, effectively delivering the air-fuel mixture to the engine's combustion chamber. Therefore, while ensuring charging efficiency, it further mitigates the phenomenon of fuel adhering to the walls within the tangential intake duct 1 due to a mismatch between fuel injection quantity and intake flow rate. The spiral intake duct 2 is characterized by its ability to generate strong vortices, effectively improving the mixing effect of air and fuel entering the combustion chamber. Furthermore, because less fuel is injected into the spiral intake duct 2, it further effectively mitigates the phenomenon of fuel adhering to the walls within the spiral intake duct 2 due to a mismatch between fuel injection quantity and intake flow rate.

[0093] Furthermore, the combustion direction of the first injector is at an acute angle to the flow direction of the gas through the tangential intake duct 1. This allows the fuel injected by the first injector into the tangential intake duct 1 to mix better with the air inside the tangential intake duct 1, improving the mixing effect. It also further mitigates the wall adhesion phenomenon caused by the fuel injected by the first injector colliding with the wall of the tangential intake duct 1. It should be noted that the flow direction of the gas through the tangential intake duct 1 here refers to the gas flow direction at the first injector inside the tangential intake duct 1.

[0094] Furthermore, the combustion direction of the second injector is at an acute angle to the flow direction of the gas through the spiral intake duct 2. This allows the fuel injected by the second injector into the spiral intake duct 2 to mix better with the air inside the spiral intake duct 2, improving the mixing effect. It also further mitigates the wall adhesion phenomenon caused by the fuel injected by the second injector colliding with the wall of the spiral intake duct 2. It should be noted that the flow direction of the gas through the spiral intake duct 2 here refers to the gas flow direction at the second injector within the spiral intake duct 2.

[0095] Therefore, by adopting this engine control method, the phenomenon of fuel sticking to the combustion chamber wall due to mismatch between fuel injection quantity and intake flow can be effectively mitigated while ensuring charging efficiency throughout the entire engine operation process. This effectively improves fuel atomization and the mixing effect of air and fuel after entering the combustion chamber. Secondly, it effectively avoids additional energy consumption.

[0096] like Figure 4 and Figure 5 As shown, the specific steps in step S200 for determining the first and second injection quantities based on the intake flow rate of the intake manifold, engine speed, and engine torque include:

[0097] S211. Determine the total amount of the first fuel injection based on the current intake air flow.

[0098] Specifically, the first total fuel injection amount is obtained by referring to the first table based on the current intake air flow rate. The first table is formed by the intake air flow rate and the first total fuel injection amount. The first table is an empirical table obtained from a large number of previous tests. As an alternative, the first total fuel injection amount is obtained by referring to the first map based on the current intake air flow rate. The first map is formed by the intake air flow rate and the first total fuel injection amount. The first map is an empirical map obtained from a large number of previous tests.

[0099] S212. Determine the first fuel injection percentage of the first fuel injection quantity to the first total fuel injection quantity, and the second fuel injection percentage of the second fuel injection quantity to the first total fuel injection quantity, based on the current engine speed and the current engine torque.

[0100] Specifically, the percentage ratio is obtained by referring to a second table based on the current engine speed and torque. The second table consists of engine speed, engine torque, and the percentage ratio, where the percentage ratio is the ratio of the first fuel injection percentage to the second fuel injection percentage. This second table is an empirical table obtained from extensive prior testing. Alternatively, the percentage ratio is obtained by referring to a second map based on the current engine speed and torque. This second map also consists of engine speed, engine torque, and the percentage ratio, where the percentage ratio is the ratio of the first fuel injection percentage to the second fuel injection percentage. This second map is an empirical map obtained from extensive prior testing.

[0101] S213. Calculate the first fuel injection quantity and the second fuel injection quantity based on the first fuel injection total quantity, the first fuel injection ratio, and the second fuel injection ratio.

[0102] Specifically, the first fuel injection total amount × the first fuel injection percentage = the first fuel injection amount; the first fuel injection total amount × the second fuel injection percentage = the second fuel injection amount.

[0103] In this embodiment, for an engine where the top surface of the piston is perpendicular to the piston's axis and the inner peripheral wall and inner bottom wall of the combustion chamber recess are perpendicularly connected, the value of the first fuel injection ratio is greater than 50% and less than 65%, and the value of the second fuel injection ratio is greater than 35% and less than 50%. It is understood that the values ​​of the first and second fuel injection ratios will differ for combustion chamber recesses of different shapes and sizes.

[0104] Step S200, which determines the first and second time periods based on the intake flow rate of the intake manifold, engine speed, and engine torque, includes the following specific steps:

[0105] Based on the current engine speed and current engine torque, determine the first crankshaft angle corresponding to the start of combustion in the tangential intake duct 1, the change in the first crankshaft angle corresponding to the duration of combustion in the tangential intake duct 1, the second crankshaft angle corresponding to the start of combustion in the spiral intake duct 2, and the change in the second crankshaft angle corresponding to the duration of combustion in the spiral intake duct 2. Determine the first time period based on the first crankshaft angle and the change in the first crankshaft angle; determine the second time period based on the second crankshaft angle and the change in the second crankshaft angle.

[0106] Specifically, the first crankshaft angle is obtained by referring to a third table based on the current engine speed and torque. This third table is composed of engine speed, engine torque, and the first crankshaft angle. This third table is an empirical table obtained from extensive prior testing. Alternatively, the first crankshaft angle can be obtained by referring to a third map based on the current engine speed and torque. This third map is also composed of engine speed, engine torque, and the first crankshaft angle. This third map is an empirical map obtained from extensive prior testing.

[0107] Specifically, the change in the first crankshaft angle is obtained by referring to the fourth table based on the current engine speed and torque. The fourth table is composed of engine speed, engine torque, and the change in the first crankshaft angle. The fourth table is an empirical table obtained from extensive previous testing. As an alternative, the change in the first crankshaft angle is obtained by referring to the fourth map based on the current engine speed and torque. The fourth map is also composed of engine speed, engine torque, and the change in the first crankshaft angle. The fourth map is an empirical map obtained from extensive previous testing.

[0108] Specifically, the second crankshaft angle is obtained by referring to the fifth table based on the current engine speed and torque. The fifth table is composed of engine speed, engine torque, and the second crankshaft angle. The fifth table is an empirical table obtained from extensive previous testing. As an alternative, the second crankshaft angle is obtained by referring to the fifth map based on the current engine speed and torque. The fifth map is also composed of engine speed, engine torque, and the second crankshaft angle. The fifth map is an empirical map obtained from extensive previous testing.

[0109] Specifically, the change in the second crankshaft angle is obtained by referring to Table 6 based on the current engine speed and torque. Table 6 is composed of engine speed, engine torque, and the change in the second crankshaft angle. Table 6 is an empirical table obtained from extensive previous testing. As an alternative, the change in the second crankshaft angle is obtained by referring to Map 6 based on the current engine speed and torque. Map 6 is also composed of engine speed, engine torque, and the change in the second crankshaft angle. Map 6 is an empirical map obtained from extensive previous testing.

[0110] As an alternative, the above tables can be merged into one table. Similarly, the above maps can be merged into one map.

[0111] It is understandable that the crankshaft angle at the start of the first time period is the first crankshaft angle, and the crankshaft angle at the start of the second time period is the second crankshaft angle.

[0112] Understandably, since the first crankshaft angle corresponding to the start of combustion in the tangential intake duct 1 and the change in the first crankshaft angle corresponding to the duration of combustion in the tangential intake duct 1 are both determined, the combustion pressure injected into the tangential intake duct 1 through the first injector is fixed each time. Similarly, since the second crankshaft angle corresponding to the start of combustion in the spiral intake duct 2 and the change in the second crankshaft angle corresponding to the duration of combustion in the spiral intake duct 2 are both determined, the combustion pressure injected into the spiral intake duct 2 through the second injector is fixed each time.

[0113] In other embodiments, the first crankshaft angle corresponding to the start of combustion in the tangential intake duct 1, the third crankshaft angle corresponding to the end of combustion in the tangential intake duct 1, the second crankshaft angle corresponding to the start of combustion in the spiral intake duct 2, and the fourth crankshaft angle corresponding to the end of combustion in the spiral intake duct 2 can also be obtained by looking up a table or a map. The first time period is determined based on the first crankshaft angle and the third crankshaft angle, and the second time period is determined based on the second crankshaft angle and the fourth crankshaft angle.

[0114] Specifically, in this embodiment, steps S211 to S213 and the step of determining the first time period and the second time period are preferably executed simultaneously to improve efficiency. In other embodiments, steps S211 to S213 are executed first, followed by the step of determining the first time period and the second time period; or, the step of determining the first time period and the second time period is executed first, followed by steps S211 to S213.

[0115] This configuration ensures that, when the engine is in its first operating condition, it can effectively mitigate the fuel adhesion problem caused by the mismatch between fuel injection volume and intake flow rate due to excessive fuel injection into one intake manifold, which is common in related technologies. Secondly, especially for the spiral intake manifold 2, it can effectively improve the air-fuel mixing effect within the spiral intake manifold 2, alleviate the fuel adhesion problem caused by fuel hitting the walls within the spiral intake manifold 2, and effectively improve the mixing effect of air and fuel after they flow into the combustion chamber.

[0116] Preferably, the first crankshaft angle is smaller than the second crankshaft angle. It can be understood that when the engine is in its first operating condition, fuel is first injected into the tangential intake duct 1 via the first injector, and the amount of fuel injected by the first injector is relatively large. Then, fuel is injected into the spiral intake duct 2 via the second injector, and the amount of fuel injected by the second injector is relatively small, forming an asynchronous injection mode of "early and large injections in the tangential intake duct 1, and late and small injections in the spiral intake duct 2".

[0117] For "early and frequent injection of tangential intake duct 1", it can better take advantage of the characteristics of large flow rate, low flow resistance and high charging efficiency of tangential intake duct 1. Thus, while ensuring charging efficiency, it can further alleviate the phenomenon that fuel is prone to hitting the wall in tangential intake duct 1 and causing adhesion due to mismatch between fuel injection quantity and intake flow rate.

[0118] Since the penetration distance of the spiral intake duct 2 is relatively short, the "later and less injection of the spiral intake duct 2" setting can better utilize the characteristics of the strong vortex formed by the spiral intake duct 2, and further alleviate the phenomenon of fuel hitting the wall and causing it to stick to the wall in the spiral intake duct 2; secondly, it can further alleviate the phenomenon of fuel hitting the wall and causing it to stick to the wall in the spiral intake duct 2 due to the mismatch between the fuel injection quantity and the intake flow rate.

[0119] This configuration allows for a better match between the structural characteristics of the tangential intake duct 1 and the spiral intake duct 2. It ensures a better match between the fuel in the tangential intake duct 1 and its penetration distance, and vice versa. This further mitigates the problem of fuel adhering to the walls of the intake ducts due to a mismatch between fuel injection quantity and intake flow rate. Secondly, this configuration allows the fuel-air mixture in the tangential intake duct 1 and the spiral intake duct 2 to flow into the combustion chamber approximately synchronously. Furthermore, the strong vortex characteristic of the spiral intake duct 2 further enhances the mixing of fuel and air within the combustion chamber, improving the uniformity of the mixture's distribution and thus effectively improving the combustion efficiency in the cylinder. The penetration distance refers to the maximum distance the fuel can travel in the injection direction.

[0120] In this embodiment, for an engine where the piston's top surface is perpendicular to the piston's axis and the inner peripheral wall and bottom wall of the combustion chamber recess are perpendicularly connected, the first crankshaft angle ranges from 330°CA to 380°CA, and the absolute value of the difference between the first and second crankshaft angles ranges from 30°CA to 50°CA. This ensures that the first crankshaft angle is less than the second crankshaft angle and defines the combustion times at which the first and second injectors begin combustion. It is understood that for combustion chamber recesses of different shapes and sizes, the range of the first crankshaft angle, the value of the second crankshaft angle, the amount of change in the first crankshaft angle, and the amount of change in the second crankshaft angle will all differ. Specifically, the crankshaft angle range for one working cycle of the engine is 0°CA to 720°CA, where 0°CA is the crankshaft angle corresponding to top dead center.

[0121] Specifically, when the engine is operating at its highest operating condition, if the cylinder pressure exceeds the maximum value of the first cylinder pressure range, although the in-cylinder combustion effect is better, the engine may experience detonation, knocking, and / or mechanical damage. If the cylinder pressure is less than the minimum value of the first cylinder pressure range, there are risks of incomplete combustion and reduced engine power performance. The first cylinder pressure range is an empirical value obtained from extensive prior testing. Therefore, to avoid these risks when the engine is operating at its highest operating condition, the preferred engine control method further includes:

[0122] When the engine is in its first operating condition, the cylinder pressure of the engine is acquired in real time.

[0123] Determine if the cylinder pressure is within the range of the first cylinder pressure.

[0124] If the cylinder pressure is within the first cylinder pressure range, then during the next combustion, the first amount of fuel is injected into the tangential intake duct 1 during the first time period, and the second amount of fuel is injected into the spiral intake duct 2 during the second time period.

[0125] If the cylinder pressure is not within the first cylinder pressure range, then during the next injection, both the first and second time periods will remain unchanged. The first and second fuel injection percentages, or the total first fuel injection amount, will be adjusted while maintaining the first fuel injection total amount unchanged. This is to avoid potential problems caused by the cylinder pressure not being within the first cylinder pressure range when the engine is in its first operating condition.

[0126] If the cylinder pressure is greater than the maximum value of the first cylinder pressure range, then during the next injection, both the first and second time periods remain unchanged. It is then determined whether the determined first fuel injection percentage minus A% is within the first preset percentage range, and whether the determined second fuel injection percentage plus B% is within the second preset percentage range. Here, A is a positive number greater than zero, and B is a positive number greater than zero.

[0127] If the determined first fuel injection percentage minus A% is within the first preset percentage range, and the determined second fuel injection percentage plus B% is within the second preset percentage range, then the adjusted first fuel injection percentage for the next injection into the tangential intake duct 1 is equal to the determined first fuel injection percentage minus A%, and the adjusted second fuel injection percentage for the next injection into the spiral intake duct 2 is equal to the determined second fuel injection percentage plus B%. This setting aims to reduce the difference between the earlier and more frequent injections in the tangential intake duct 1 and the later and less frequent injections in the spiral intake duct 2, i.e., to reduce the difference between asynchronous injection amounts, thereby mitigating the phenomenon of cylinder pressure exceeding the maximum value of the first cylinder pressure range and improving the engine's operational safety and reliability.

[0128] If the determined first fuel injection percentage minus A% is not within the first preset percentage range, and / or the determined second fuel injection percentage plus B% is not within the second preset percentage range, then it is determined whether the determined first fuel injection total amount minus C is less than the first minimum limit fuel injection total amount. Wherein, C is the first adjustment step size of the first fuel injection total amount.

[0129] If the total first fuel injection amount determined this time minus C is greater than or equal to the first minimum limit fuel injection amount, then the total first fuel injection amount for the next time will be adjusted to be the total first fuel injection amount determined this time minus C.

[0130] If the first fuel injection total amount determined this time minus C is less than the first minimum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to equal the first minimum limit fuel injection total amount.

[0131] It is understandable that when the determined first fuel injection ratio minus A% is not within the first preset ratio range, and / or the determined second fuel injection ratio plus B% is not within the second preset ratio range, the phenomenon of cylinder pressure exceeding the maximum value of the first cylinder pressure range is alleviated by reducing the total amount of the first fuel injection in the next operation, thereby improving the engine's operational safety and reliability. Thus, when the engine is operating at its highest operating condition, the engine's power performance can be guaranteed while effectively improving its power safety and reliability.

[0132] Specifically, both the first and second preset ratio ranges are empirical ranges obtained from extensive prior testing. The first minimum limit fuel injection total is an empirical value obtained from extensive prior testing.

[0133] For example, in this embodiment, the first preset ratio range is 50% to 65%; the second preset ratio range is 35% to 50%. Further, in this embodiment, the values ​​of A and B are both set to 5. It is understood that the values ​​of A and B can be adaptively increased or decreased according to actual working conditions.

[0134] If the cylinder pressure is less than the minimum value of the first cylinder pressure range, then during the next injection, both the first and second time periods remain unchanged. It is then determined whether the determined first fuel injection percentage plus D% is within the first preset percentage range, and whether the determined second fuel injection percentage minus E% is within the second preset percentage range. Here, D is a positive number greater than zero, and E is a positive number greater than zero.

[0135] If the determined first fuel injection percentage plus D% is within the first preset percentage range, and the determined second fuel injection percentage minus E% is within the second preset percentage range, then the adjusted first fuel injection percentage for the next injection into the tangential intake duct 1 is equal to the determined first fuel injection percentage plus D%, and the adjusted second fuel injection percentage for the next injection into the spiral intake duct 2 is equal to the determined second fuel injection percentage minus E%. This increases the difference between the injection quantities of "early and abundant injection in the tangential intake duct 1, and late and less injection in the spiral intake duct 2," that is, increases the difference between asynchronous injection quantities, allowing more air-fuel mixture to accumulate in the engine's combustion chamber in a short time, and resulting in better air-fuel mixture mixing, thereby promoting in-cylinder combustion and increasing cylinder pressure.

[0136] If the first fuel injection percentage plus D% determined this time is not within the first preset percentage range, and / or the second fuel injection percentage minus E% determined this time is not within the second preset percentage range, then it is determined whether the first fuel injection total amount plus F determined this time is greater than the first maximum limit fuel injection total amount. Wherein, F is the second adjustment step size of the first fuel injection total amount.

[0137] If the first fuel injection total amount determined this time plus F is greater than or equal to the first maximum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to equal the first maximum limit fuel injection total amount.

[0138] If the total first fuel injection amount determined this time plus F is less than the total first maximum limit fuel injection amount, then the total first fuel injection amount for the next time will be adjusted to the total first fuel injection amount determined this time plus F.

[0139] It is understandable that if the first fuel injection percentage plus D% is not within the first preset percentage range, and / or the second fuel injection percentage minus E% is not within the second preset percentage range, then the combustion effect will be improved by increasing the total amount of the first fuel injection in the next cycle, so as to further promote in-cylinder combustion and increase cylinder pressure.

[0140] Specifically, the first maximum limit of fuel injection is an empirical value obtained from a large number of previous tests.

[0141] In this embodiment, the values ​​of D and E are both set to 5. It is understood that the values ​​of D and E can be increased or decreased according to actual working conditions.

[0142] In this embodiment, the first adjustment step size of the first fuel injection quantity is exemplarily set to be equal to the second adjustment step size of the first fuel injection quantity. In other embodiments, the first adjustment step size and the second adjustment step size of the first fuel injection quantity may not be equal.

[0143] Specifically, the steps in step S400 for determining the total amount of second fuel injected into the tangential intake duct 1 based on the intake flow rate of the intake manifold are as follows:

[0144] The second total fuel injection amount is obtained by referring to Table 7 based on the current intake airflow. Table 7 is composed of the intake airflow and the second total fuel injection amount. Table 7 is an empirical table obtained from extensive previous testing. Alternatively, the second total fuel injection amount is obtained by referring to Map 7 based on the current intake airflow. Map 7 is composed of the intake airflow and the second total fuel injection amount. Map 7 is an empirical map obtained from extensive previous testing.

[0145] For example, the specific steps of the third time period in step S400, in which combustion is injected into the tangential intake duct 1 based on engine speed and engine torque, are as follows:

[0146] Based on the current engine speed and torque, determine the fifth crankshaft angle corresponding to the start of combustion in the tangential intake duct 1, and the third crankshaft angle change corresponding to the duration of combustion in the tangential intake duct 1. The third time period is then determined based on the fifth crankshaft angle and the change in the third crankshaft angle.

[0147] It is understandable that the crankshaft angle at the start of the third time period is the fifth crankshaft angle.

[0148] Specifically, the fifth crankshaft angle is obtained by referring to Table 8 based on the current engine speed and torque. Table 8 is composed of engine speed, engine torque, and the fifth crankshaft angle. Table 8 is an empirical table obtained from extensive previous testing. As an alternative, the fifth crankshaft angle is obtained by referring to Map 8 based on the current engine speed and torque. Map 8 is composed of engine speed, engine torque, and the fifth crankshaft angle. Map 8 is an empirical map obtained from extensive previous testing.

[0149] Specifically, the change in the third crankshaft angle is obtained by referring to Table 9 based on the current engine speed and torque. Table 9 is composed of engine speed, engine torque, and the change in the third crankshaft angle. Table 9 is an empirical table obtained from extensive previous testing. As an alternative, the change in the third crankshaft angle is obtained by referring to Map 9 based on the current engine speed and torque. Map 9 is composed of engine speed, engine torque, and the change in the third crankshaft angle. Map 9 is an empirical map obtained from extensive previous testing.

[0150] In other embodiments, the fifth crankshaft angle corresponding to the start of combustion in the tangential intake duct 1 and the sixth crankshaft angle corresponding to the end of combustion in the tangential intake duct 1 can also be obtained by looking up a table or a map; the third time period is determined based on the fifth crankshaft angle and the sixth crankshaft angle.

[0151] As an alternative, the above tables can be merged into one table. Similarly, the above maps can be merged into one map.

[0152] This configuration ensures that, when the engine is in its second operating condition, it can effectively mitigate the phenomenon of fuel adhering to the walls of the tangential intake manifold 1 while maintaining charging efficiency.

[0153] Specifically, when the engine is in the second operating condition, if the cylinder pressure is greater than the maximum value of the second cylinder pressure range, although the in-cylinder combustion effect is better, it will cause potential problems such as increased fuel consumption and / or mechanical damage. If the cylinder pressure is less than the minimum value of the second cylinder pressure range, it will also cause potential problems such as incomplete in-cylinder combustion and decreased engine power performance. The second cylinder pressure range is an empirical value obtained from extensive prior testing. Therefore, to avoid the above-mentioned problems when the engine is in the second operating condition, the preferred engine control method further includes:

[0154] When the engine is in the second operating condition, the cylinder pressure of the engine is acquired in real time.

[0155] Determine if the cylinder pressure is within the range of the second cylinder pressure.

[0156] If the cylinder pressure is within the second cylinder pressure range, then during the next combustion, the total amount of the second fuel injection will be injected into the tangential intake port 1 within the third time period.

[0157] If the cylinder pressure is not within the range of the second cylinder pressure, then during the next injection, the third time period remains unchanged, and the total amount of the second fuel injection is adjusted.

[0158] If the cylinder pressure is greater than the maximum value of the second cylinder pressure range, then during the next injection, the third time period remains unchanged, and it is determined whether the determined second fuel injection total amount minus G is less than the second minimum limit fuel injection total amount. Here, G is the first adjustment step size of the second fuel injection total amount.

[0159] If the total amount of the second fuel injection determined this time minus G is greater than or equal to the total amount of the second minimum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to the total amount of the second fuel injection determined this time minus G.

[0160] If the total amount of the second fuel injection determined this time minus G is less than the total amount of the second minimum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to equal the total amount of the second minimum limit fuel injection.

[0161] The second minimum limit for total fuel injection is an empirical value obtained from numerous previous tests.

[0162] It is understandable that when the cylinder pressure is greater than the maximum value of the second cylinder pressure range, the phenomenon of the cylinder pressure being greater than the maximum value of the second cylinder pressure range is alleviated by reducing the total amount of the second fuel injection in the next cycle. This can also avoid increased fuel consumption and extend the service life of the engine.

[0163] If the cylinder pressure is less than the minimum value of the second cylinder pressure range, then during the next injection, the third time period remains unchanged, and it is determined whether the second fuel injection total amount plus H determined in this instance is greater than the second maximum limit fuel injection total amount. Here, H is the second adjustment step size of the second fuel injection total amount.

[0164] If the total amount of the second fuel injection determined this time plus H is greater than or equal to the total amount of the second maximum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to the total amount of the second maximum limit fuel injection.

[0165] If the total amount of the second fuel injection determined this time plus H is less than the total amount of the second maximum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to the total amount of the second fuel injection determined this time plus H.

[0166] The second maximum limit of fuel injection is an empirical value obtained from a large number of previous tests.

[0167] It is understandable that when the cylinder pressure is less than the minimum value of the second cylinder pressure range, the combustion effect is improved by increasing the total amount of the second fuel injection in the next cycle, so as to further promote in-cylinder combustion and increase cylinder pressure.

[0168] In this embodiment, the first adjustment step size of the second fuel injection quantity is set to be equal to the second adjustment step size of the second fuel injection quantity. In other embodiments, the first adjustment step size of the second fuel injection quantity and the second adjustment step size of the second fuel injection quantity may not be equal.

[0169] Combination Figure 6 and Figure 7 As shown, the methanol engine in this embodiment is controlled by the engine control method described above. Compared to related technologies that simultaneously inject fuel using at least two injectors in one intake manifold, when the engine is in its first operating condition, the amount of methanol fuel adhering to the engine wall is reduced by 15%, the amount of gaseous methanol in the cylinder is increased by 6%, and the in-cylinder mixture non-uniformity is reduced by 45%. Figure 6 The graph before optimization corresponds to the line graph of wall adhesion when two injectors simultaneously inject fuel in an intake manifold, while the graph after optimization corresponds to the line graph of wall adhesion when the engine control method of this embodiment is used to control the methanol engine. Figure 7The graph before optimization corresponds to the gaseous methanol quantity histogram formed when two injectors simultaneously inject fuel in one intake manifold, while the graph after optimization corresponds to the gaseous methanol quantity histogram formed when the engine control method of this embodiment is used to control the methanol engine.

[0170] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An engine control method, characterized in that, The cylinder head of the engine is provided with an independent tangential intake passage (1) and a spiral intake passage (2). One end of the tangential intake passage (1) and one end of the spiral intake passage (2) are connected to the intake manifold of the engine. The other end of the tangential intake passage (1) and the other end of the spiral intake passage (2) are connected to the combustion chamber of the engine. The engine control method includes: When the engine is in the first operating condition, the fuel injection parameters are determined based on the intake flow rate of the intake manifold, the engine speed and the engine torque. The fuel injection parameters include the first amount of fuel injected into the tangential intake (1), the second amount of fuel injected into the spiral intake (2), the first time period of fuel injection into the tangential intake (1), and the second time period of fuel injection into the spiral intake (2). During the first time period, fuel of the first amount of fuel is injected into the tangential intake (1), and fuel of the second amount of fuel is injected into the spiral intake (2) during the second time period; the first amount of fuel is greater than the second amount of fuel. Specifically, when the engine load is greater than or equal to a preset load percentage, the engine is in the first operating condition.

2. The engine control method according to claim 1, characterized in that, The crankshaft angle corresponding to the start time of the first time period is the first crankshaft angle, and the crankshaft angle corresponding to the start time of the second time period is the second crankshaft angle. The first crankshaft angle is smaller than the second crankshaft angle.

3. The engine control method according to claim 2, characterized in that, The absolute value of the difference between the first crankshaft angle and the second crankshaft angle ranges from 30°CA to 50°CA.

4. The engine control method according to any one of claims 1-3, characterized in that, The specific steps for determining the first and second injection quantities based on the intake manifold flow rate, engine speed, and engine torque include: The total amount of the first fuel injection is determined based on the current intake airflow. The first fuel injection percentage of the first fuel injection quantity to the first total fuel injection quantity and the second fuel injection percentage of the second fuel injection quantity to the first total fuel injection quantity are determined based on the current engine speed and the current engine torque. The first fuel injection quantity and the second fuel injection quantity are calculated based on the first total fuel injection quantity, the first fuel injection percentage, and the second fuel injection percentage.

5. The engine control method according to claim 4, characterized in that, The piston of the engine has a combustion chamber recess on its top surface, which is perpendicular to the axial direction of the piston. The inner peripheral wall and the inner bottom wall of the combustion chamber recess are perpendicularly connected. The first fuel injection ratio is greater than 50% and less than 65%, and the second fuel injection ratio is greater than 35% and less than 50%.

6. The engine control method according to claim 4, characterized in that, The engine control method further includes: When the engine is in the first operating condition, the cylinder pressure of the engine is acquired in real time; Determine whether the cylinder pressure is within the range of the first cylinder pressure; If the cylinder pressure is not within the first cylinder pressure range, then during the next injection, both the first time period and the second time period remain unchanged, and the first fuel injection ratio and the second fuel injection ratio are adjusted, or the first fuel injection total amount is adjusted, while the first fuel injection total amount remains unchanged.

7. The engine control method according to claim 6, characterized in that: If the cylinder pressure is greater than the maximum value of the first cylinder pressure range, then during the next injection, both the first time period and the second time period remain unchanged, and it is determined whether the first fuel injection ratio minus A% is within the first preset ratio range, and whether the second fuel injection ratio plus B% is within the second preset ratio range. If the first fuel injection percentage determined this time minus A% is within the first preset percentage range, and the second fuel injection percentage determined this time plus B% is within the second preset percentage range, then the first fuel injection percentage injected into the tangential intake (1) next time is adjusted to be equal to the first fuel injection percentage determined this time minus A%, and the second fuel injection percentage injected into the spiral intake (2) next time is adjusted to be equal to the second fuel injection percentage determined this time plus B%. Where A is a positive number greater than zero, and B is a positive number greater than zero.

8. The engine control method according to claim 7, characterized in that, If the first fuel injection percentage minus A% is not within the first preset percentage range, and / or the second fuel injection percentage plus B% is not within the second preset percentage range, then it is determined whether the first fuel injection total minus C is less than the first minimum limit fuel injection total. If the first fuel injection total amount determined this time minus C is greater than or equal to the first minimum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to be equal to the first fuel injection total amount determined this time minus C. If the first fuel injection total amount determined this time minus C is less than the first minimum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to equal the first minimum limit fuel injection total amount. Wherein, C is the first adjustment step size of the first total fuel injection.

9. The engine control method according to claim 6, characterized in that: If the cylinder pressure is less than the minimum value of the first cylinder pressure range, then during the next injection, both the first time period and the second time period remain unchanged, and it is determined whether the first fuel injection ratio plus D% determined this time is within the first preset ratio range, and whether the second fuel injection ratio minus E% determined this time is within the second preset ratio range. If the first fuel injection percentage plus D% is within the first preset percentage range, and the second fuel injection percentage minus E% is within the second preset percentage range, then the first fuel injection percentage to be injected into the tangential intake (1) next time is adjusted to be equal to the first fuel injection percentage plus D% and the second fuel injection percentage to be injected into the spiral intake (2) next time is adjusted to be equal to the second fuel injection percentage minus E%. Where D is a positive number greater than zero, and E is a positive number greater than zero.

10. The engine control method according to claim 9, characterized in that, If the first fuel injection percentage plus D% determined this time is not within the first preset percentage range, and / or the second fuel injection percentage minus E% determined this time is not within the second preset percentage range, then it is determined whether the first fuel injection total plus F determined this time is greater than the first maximum limit fuel injection total. If the first fuel injection total amount determined this time plus F is greater than or equal to the first maximum limit fuel injection total amount, then the first fuel injection total amount for the next time will be adjusted to equal the first maximum limit fuel injection total amount. If the total first fuel injection amount determined this time plus F is less than the first maximum limit fuel injection amount, then the total first fuel injection amount for the next time will be adjusted to be the total first fuel injection amount determined this time plus F. Where F is the second adjustment step of the first total fuel injection.

11. The engine control method according to any one of claims 1-3, characterized in that, When the engine is in the second operating condition, the total amount of the second fuel injection into the tangential intake passage (1) is determined based on the intake flow rate of the intake manifold, and the third time period for the fuel injection into the tangential intake passage (1) is determined based on the engine speed and engine torque. During the third time period, the total amount of the second fuel injection is injected into the tangential intake (1); Specifically, when the engine load is less than the preset load percentage, the engine is in the second operating condition.

12. The engine control method according to claim 11, characterized in that, The engine control method further includes: When the engine is in the second operating condition, the cylinder pressure of the engine is acquired in real time; Determine whether the cylinder pressure is within the range of the second cylinder pressure; If the cylinder pressure is not within the range of the second cylinder pressure, then during the next combustion, the third time period remains unchanged, and the total amount of the second fuel injection is adjusted.

13. The engine control method according to claim 12, characterized in that: If the cylinder pressure is greater than the maximum value of the second cylinder pressure range, then during the next injection, the third time period remains unchanged, and it is determined whether the second fuel injection total amount determined this time minus G is less than the second minimum limit fuel injection total amount; If the total amount of the second fuel injection determined this time minus G is greater than or equal to the total amount of the second minimum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to be the total amount of the second fuel injection determined this time minus G. If the total amount of the second fuel injection determined this time minus G is less than the total amount of the second minimum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to equal the total amount of the second minimum limit fuel injection. Wherein, G is the first adjustment step of the second total fuel injection quantity.

14. The engine control method according to claim 12, characterized in that: If the cylinder pressure is less than the minimum value of the second cylinder pressure range, then during the next injection, the third time period remains unchanged, and it is determined whether the second fuel injection total amount plus H determined this time is greater than the second maximum limit fuel injection total amount; If the total amount of the second fuel injection determined this time plus H is greater than or equal to the total amount of the second maximum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to the total amount of the second maximum limit fuel injection. If the total amount of the second fuel injection determined this time plus H is less than the total amount of the second maximum limit fuel injection, then the total amount of the second fuel injection next time will be adjusted to be equal to the total amount of the second fuel injection determined this time plus H. Wherein, H is the second adjustment step size of the second total fuel injection.

15. An engine, including a controller, characterized in that, The cylinder head of the engine is provided with an independent tangential intake passage (1) and a spiral intake passage (2). One end of the tangential intake passage (1) and one end of the spiral intake passage (2) are connected to the intake manifold of the engine. The other end of the tangential intake passage (1) and the other end of the spiral intake passage (2) are connected to the combustion chamber of the engine. The controller is used to implement the engine control method according to any one of claims 1-14.

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