Engine ignition control method, engine ignition control system and vehicle

Abstract

The invention discloses an engine ignition control method, an engine ignition control system and a vehicle. The method comprises the steps that basic ignition energy of the ignition coil structure is determined; based on the basic ignition energy, a first relation table including the engine rotating speed, the power supply voltage and the basic magnetizing time is obtained; engine rotating speed information and power supply voltage information are obtained, and corresponding basic magnetizing time is obtained and serves as first magnetizing time information; controlling the power supply to magnetize the ignition coil structure according to the first magnetizing time information; monitoring the ignition frequency and the torque fluctuation value of the engine; judging whether the engine misfire frequency is greater than or equal to a misfire threshold value or whether the torque fluctuation value is greater than or equal to a preset fluctuation upper limit; if yes, increasing preset incremental time to obtain second magnetizing time; judging whether the engine misfire frequency is equal to zero and whether the torque fluctuation value is smaller than a preset fluctuation lower limit; and if yes, stable combustion of the engine is determined. According to the method, the ignition stability in the lean-burn mode of the engine is improved.

Description

Technical Field

[0001] The present application relates to the technical field of engine ignition control, and particularly relates to an engine ignition control method, an engine ignition control system and a vehicle. Background Art

[0002] With the intensification of the global energy crisis and environmental problems, engine low fuel consumption technology has become an important technology in the automotive industry. Among them, lean burn technology is an important technology for future engines to reduce fuel consumption. The core principle of lean burn is to dilute the combustion mixture gas, extend the combustion time, thereby reducing the combustion temperature and reducing the generation of nitrogen oxides (NOx). This technology can significantly reduce fuel consumption without affecting power output, while reducing the emission of harmful pollutants. Compared with traditional stoichiometric rich combustion, lean burn has obvious advantages in combustion efficiency and environmental protection performance. With the continuous tightening of environmental protection regulations and the increasing demand for energy conservation, lean burn technology will be more widely promoted and applied in the future.

[0003] The core of lean burn technology lies in achieving reliable and stable ignition. In the lean burn mode, the ignition system needs to generate high and stable ignition energy. However, due to the complex working state of the engine and the ignition environment, and the ignition energy of the ignition system is closely related to the working state of the engine and the ignition environment, the current ignition system has poor ignition stability in the lean burn mode. Summary of the Invention

[0004] In view of the above, it is necessary to provide an engine ignition control method, an engine ignition control system and a vehicle to improve the ignition stability in the lean burn mode.

[0005] An embodiment of the present application provides an engine ignition control method, including: determining the basic ignition energy of the ignition coil structure; obtaining a first relationship table based on the basic ignition energy, where the first relationship table includes the engine speed, the supply voltage, and the basic magnetization time; obtaining the engine speed information and the supply voltage information under the current working condition; obtaining the corresponding basic magnetization time information according to the engine speed information, the supply voltage information, and the first relationship table, and using the basic magnetization time information as the first magnetization time; controlling the power supply to supply power to the ignition coil structure according to the first magnetization time and controlling the ignition coil structure to release the ignition energy; monitoring the number of engine misfires and the torque fluctuation value; determining whether the number of engine misfires is greater than or equal to the misfire threshold or the torque fluctuation value is greater than or equal to the preset fluctuation upper limit; if so, adding a preset increment time to the first magnetization time to obtain a second magnetization time; controlling the power supply to supply power to the ignition coil structure according to the second magnetization time and controlling the ignition coil structure to release the ignition energy; determining whether the number of engine misfires is equal to zero and the torque fluctuation value is less than the preset fluctuation lower limit, where the preset fluctuation lower limit is less than or equal to the preset fluctuation upper limit; if so, determining that the engine stably burns under the current working condition.

[0006] In some embodiments, when determining whether the number of engine misfires is greater than or equal to the misfire threshold or the torque fluctuation value is greater than or equal to the preset fluctuation upper limit; if not, perform the step of determining whether the number of engine misfires is equal to zero and the torque fluctuation value is less than the preset fluctuation lower limit.

[0007] In some embodiments, after the step of controlling the power supply to supply power to the ignition coil structure according to the second magnetization time and controlling the ignition coil structure to release the ignition energy, when determining whether the number of engine misfires is equal to zero and the torque fluctuation value is less than the preset fluctuation lower limit; if not, use the second magnetization time as the first magnetization time, and repeat the step of adding a preset increment time to the first magnetization time to obtain a second magnetization time.

[0008] In some embodiments, before the step of obtaining the engine speed information and the power supply voltage information under the current working condition, the method further includes: determining the maximum ignition energy of the ignition coil structure; obtaining a second relationship table based on the maximum ignition energy, where the second relationship table includes the engine speed, the power supply voltage, and the maximum magnetization time; after the step of obtaining the engine speed information and the power supply voltage information under the current working condition, the method further includes: obtaining the corresponding maximum magnetization time information according to the engine speed information, the power supply voltage information, and the second relationship table; after the step of increasing the first magnetization time by a preset increment time to obtain a second magnetization time, the method further includes: determining whether the second magnetization time is less than or equal to the maximum magnetization time information; if so, performing the step of controlling the power supply to supply power to the ignition coil structure according to the second magnetization time and controlling the ignition coil structure to release ignition energy.

[0009] In some embodiments, after the step of determining the basic ignition energy of the ignition coil structure, the method further includes: determining the target air-fuel ratio of the engine under various working conditions based on the basic ignition energy; when determining whether the second magnetization time is less than or equal to the maximum magnetization time information; if not, obtaining the target air-fuel ratio under the current working condition and using the target air-fuel ratio as the current air-fuel ratio; controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio; determining whether the number of engine misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; if so, determining that the engine stably burns under the current working condition.

[0010] In some embodiments, after the step of controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio, when determining whether the number of engine misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; if not, repeating the step of controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio.

[0011] In some embodiments, after the step of controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio, when determining whether the number of engine misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; if so, sending a spark plug replacement alarm message before or after the step of determining that the engine stably burns under the current working condition.

[0012] Through the above steps, the engine ignition control method according to the embodiment of the present application varies the magnetization time of the ignition coil structure according to the engine speed information and the power supply voltage information under the current working condition, and adjusts it according to the number of engine misfires and the torque fluctuation value feedback by the engine, thereby ensuring that the ignition coil structure can generate high and stable ignition energy, and further improving the ignition stability of the engine in the lean combustion mode.

[0013] The embodiment of the present application also provides an engine ignition control system, including an engine, an ignition coil structure, a spark plug and an engine controller. The ignition coil structure is arranged on the engine; the spark plug is arranged on the engine and connected to the ignition coil structure; the engine controller is electrically connected to the engine and the ignition coil structure, and is used to load and execute the engine ignition control method as described above.

[0014] By implementing the above engine ignition control method, the engine ignition control system according to the embodiment of the present application improves the stability of controlling the engine ignition.

[0015] In some embodiments, the ignition coil structure includes two ignition coils and an output terminal. The two ignition coils are arranged in parallel, and the output ends of the two ignition coils are both connected to the output terminal, and the output terminal is used to be connected to the spark plug. The embodiment of the present application also provides a vehicle, including the engine ignition control system as described above.

[0016] By setting the above engine ignition control system that implements the above engine ignition control method, the vehicle according to the embodiment of the present application improves the ignition stability of the engine in the lean combustion mode. Description of the Drawings

[0017] Figure 1 is a flowchart of the engine ignition control method provided by the embodiment of the present application.

[0018] Figure 2 is a schematic diagram of the relationship between the target air-fuel ratio of the engine determined based on the basic ignition energy and the engine power point.

[0019] Figure 3 is an architecture diagram of the engine ignition control system provided by the embodiment of the present application.

[0020] Figure 4 is Figure 3 a circuit schematic diagram of the ignition coil structure in the shown engine ignition control system.

[0021] Figure 5 is Figure 4 a schematic comparison diagram of the relationship between the discharge duration and the discharge current of the secondary coil of the shown ignition coil structure and the existing single ignition coil.

[0022] Figure 6 It is a schematic structural diagram of a vehicle provided by an embodiment of the present application.

[0023] Main element symbol description: Vehicle 1000, engine ignition control system 100, engine controller 10, ignition coil structure 20, ignition coil 21, primary coil 211, first end 2111, second end 2112, secondary coil 212, output end 2121, ground end 2122, triode 213, anti - feedback diode 214, suppression resistor 215, output terminal 22, spark plug 30, engine 40, battery management module 50, power supply 51, crankshaft position sensor 60, knock sensor 70. Detailed implementation manners

[0024] The following details the implementation manners of the present application. The examples of the implementation manners are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The implementation manners described below with reference to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application.

[0025] In the description of the present application, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, it should be noted that the meaning of "plural" is two or more unless otherwise specifically defined.

[0026] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that can communicate with each other. It can be a direct connection or an indirect connection through an intermediate medium. It can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to specific circumstances.

[0027] Some embodiments of the present application will be described in detail below with reference to the drawings.

[0028] Please refer to Figure 1 and Figure 3, embodiments of the present application provide an engine ignition control method, which is applied to an engine ignition control system 100. Among them, the engine ignition control system 100 can be applied to hybrid vehicles, fuel vehicles, etc. For the sake of easy understanding, embodiments of the present application take the engine ignition control method applied to the engine ignition control system 100 of a hybrid vehicle as an example for illustration. Obviously, this is not a limitation on the embodiments of the present application.

[0029] Please refer to Figure 1 and Figure 3 , in embodiments of the present application, the engine ignition control method includes the following steps: Step S100, determine the basic ignition energy of the ignition coil structure 20.

[0030] Specifically, when the engine 40 is in the lean burn mode, its air-fuel ratio λ > 2, and it is more sensitive to ignition energy. The supply voltage value of the ignition coil structure 20 will have a greater impact on the output magnitude of the ignition energy. Under normal operating conditions of the vehicle 1000 (as shown in Figure 6 ), the voltage range of the power supply 51 (as shown in Figure 4 ) is generally 12V to 14V. If the bench test is carried out for calibration by supplying power to the ignition coil structure 20 at the supply voltage of 14V of the power supply 51, at a voltage of 14V, the magnetization time is 5.14ms, corresponding to an ignition energy of 290mJ. However, if the bench test is carried out for calibration by supplying power to the ignition coil structure 20 at the supply voltage of 12V of the power supply 51, at a voltage of 12V, the maximum magnetization time is 5.56ms (the coil thermal balance requirements need to be comprehensively considered), corresponding to an ignition energy of 240mJ, which is much less than 290mJ. In this case, after the engine 40 is installed on the vehicle 1000, there will be problems such as some lean burn conditions that cannot be normally ignited, or the engine 40 burns unstably, and the in-cylinder cyclic fluctuation value increases sharply. Therefore, considering the unstable supply voltage of the ignition coil structure 20, in this embodiment, a bench test is carried out based on the lowest supply voltage value of 12V to determine that the basic ignition energy of the ignition coil structure 20 is 240mJ.

[0031] Step S103, obtain a first relationship table based on the basic ignition energy. The first relationship table includes the engine speed, supply voltage, and basic magnetization time.

[0032] Specifically, based on the basic ignition energy, the relationship between the engine speed, supply voltage, and basic magnetization time is determined through the bench test of the engine 40, and the relationship between the engine speed, supply voltage, and basic magnetization time is converted into a first relationship table and stored in the engine controller 10.

[0033] During the actual operation of the engine 40, the fuel cut-off speed is generally set within the engine speed of 4000 r / min (that is, the influence of the engine speed within 4000 r / min on the ignition of the ignition coil structure 20 is focused on). The engine speed directly affects the magnetization ignition frequency of the ignition coil structure 20. Therefore, the relationship between the engine speed, the supply voltage, and the basic magnetization time is formed into a first relationship table. The first relationship table of this embodiment is shown in Table 1. According to the engine speed increasing by 200 r / min or 400 r / min, and the supply voltage of the ignition coil structure 20 increasing by 1 V at intervals, the magnetization time is preset. When presetting the magnetization time, it is necessary to consider that the ignition coil structure 20 reaches thermal equilibrium at the corresponding engine speed and supply voltage. In addition, it should be noted that the operable voltage range of the ignition coil structure 20 is 6V - 16V. This embodiment focuses on the relationship between the engine speed, the supply voltage, and the basic magnetization time within the range of 12V - 14V. The data outside 12V - 14V are all obtained through tests considering abnormal situations.

[0034] Table 1 In some other embodiments, the engine speed can also be set to increase by 100 r / min as needed, and the supply voltage of the ignition coil structure 20 increases by 0.5 V at intervals to preset the magnetization time, so as to obtain a more refined first relationship table. The embodiments of this application do not make specific limitations on this.

[0035] In some other embodiments, in addition to the engine speed, the supply voltage, and the basic magnetization time, the first relationship table may also include other information related to engine ignition control. The embodiments of this application do not make specific limitations on this.

[0036] Step S105: Obtain the engine speed information and the supply voltage information under the current working condition.

[0037] Specifically, please refer to Figure 3 and Figure 4 , the engine controller 10 is electrically connected to the battery management module 50, the knock sensor 70, the crankshaft position sensor 60, and the ignition coil structure 20. The engine controller 10 obtains the supply voltage information of the power supply 51 under the current working condition through the battery management module 50, and the engine controller 10 obtains the engine speed information under the current working condition through the crankshaft position sensor 60.

[0038] Step S107: Obtain the corresponding basic magnetization time information according to the engine speed information, the supply voltage information, and the first relationship table, and use the basic magnetization time information as the first magnetization time.

[0039] After obtaining the engine speed information and the power supply voltage information under the current working condition, the corresponding basic magnetization time information can be obtained by retrieving the first relational table. Step S109: Control the power supply 51 to supply power to the ignition coil structure 20 according to the first magnetization time, and control the ignition coil structure 20 to release ignition energy.

[0040] Specifically, after obtaining the first magnetization time, the engine controller 10 controls the power supply 51 to supply power to the ignition coil structure 20 according to the first magnetization time. Then, the engine controller 10 controls the ignition coil structure 20 to release ignition energy to the spark plug 30, and the spark plug 30 performs an ignition operation.

[0041] Step S111: Monitor the engine misfire count and the torque fluctuation value.

[0042] Specifically, the engine controller 10 obtains the engine misfire count in real time through the knock sensor 70, and the engine controller 10 obtains the torque fluctuation value in real time through the crankshaft position sensor 60.

[0043] In order to verify whether the ignition energy output by the ignition coil structure 20 meets the requirements for the stable operation of the lean combustion of the engine 40 under the corresponding working conditions, the engine controller 10 monitors the misfire count of each cylinder of the engine 40 and the engine torque fluctuation in real time, so as to judge whether the engine 40 burns stably in the lean burn mode.

[0044] Step S113: Judge whether the engine misfire count is greater than or equal to the misfire threshold or whether the torque fluctuation value is greater than or equal to the preset fluctuation upper limit.

[0045] The engine misfire count is the misfire count of a single cylinder of the engine 40. The engine misfire count is set as Nlossfire, and the misfire threshold is set as Nlossmax. Generally, when the misfire count of the engine 40 per unit time is greater than zero, it means that the ignition energy is insufficient and the in-cylinder combustion is not good. When the misfire count per unit time is greater than or equal to 2, it means that the ignition energy is seriously insufficient and the combustible mixture cannot be ignited. Therefore, the value of Nlossmax can be set to 2.

[0046] The torque fluctuation value is set as Tcov, and the preset fluctuation upper limit is set as Tcovmax. When Tcov ≥ 5%, it means that the ignition energy is insufficient at this time, and the combustible mixture cannot be ignited or the in-cylinder combustion is not good. Therefore, the value of Tcovmax can be set to 5 N·m.

[0047] In this step, the engine controller 10 prestores a misfire threshold Nlossmax and a preset fluctuation upper limit Tcovmax. The engine controller 10 determines whether Nlossfire≥Nlossmax or Tcov≥Tcovmax based on the obtained values of Nlossfire and Tcov.

[0048] When step S113 is executed, if it is Yes, then step S115 is executed, and a preset increment time is added to the first magnetization time to obtain a second magnetization time.

[0049] Specifically, when the engine misfire count is greater than or equal to the misfire threshold or the torque fluctuation value is greater than or equal to the preset fluctuation upper limit, that is, when Nlossfire≥Nlossmax or Tcov≥Tcovmax, it is determined that the ignition energy of the ignition coil structure 20 is insufficient. At this time, a preset increment time needs to be added to the first magnetization time to obtain a second magnetization time.

[0050] Among them, the first magnetization time is set to Tdwell, the preset increment time is set to Δt, the second magnetization time is set to Tdwell', the value of Δt can be 0.1 ms, and Tdwell' = Tdwell + Δt. With such a setting, it can effectively prevent adding too much to the first magnetization time at once, causing the ignition coil structure 20 to not meet the thermal balance, thereby reducing the probability of damage to the ignition coil structure 20.

[0051] In some other embodiments, the value of Δt can also be set to 0.05 ms, 0.2 ms, etc. according to actual situations, and the embodiments of the present application do not make specific limitations on this.

[0052] Step S117, control the power supply 51 to supply power to the ignition coil structure 20 according to the second magnetization time and control the ignition coil structure 20 to release ignition energy.

[0053] Specifically, the engine controller 10 controls the power supply 51 to supply power to the ignition coil structure 20 according to the value of the second magnetization time Tdwell'. After that, the engine controller 10 controls the ignition coil structure 20 to release ignition energy to the spark plug 30, and the spark plug 30 performs an ignition operation.

[0054] Step S119, determine whether the engine misfire count is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit, where the preset fluctuation lower limit is less than or equal to the preset fluctuation upper limit.

[0055] Specifically, the preset lower limit of the fluctuation is set to Tcovmin, and the value of Tcovmin can be set to 3 N·m, that is, Tcovmin < Tcovmax. When Nlossfire = 0 and Tcov < Tcovmin, it is determined that the ignition energy of the ignition coil structure 20 can enable the engine 40 to stably burn in the lean combustion mode.

[0056] In some other embodiments, by reasonably setting the critical point, the value of the preset lower limit of the fluctuation Tcovmin can also be set to be the same as the value of the preset upper limit of the fluctuation Tcovmax. The embodiments of the present application do not make specific limitations on this.

[0057] When performing step S119, if it is yes, then step S121 is performed to determine that the engine 40 stably burns under the current working condition.

[0058] Specifically, when the number of engine misfires of the engine 40 is equal to zero and the torque fluctuation value is less than the preset lower limit of the fluctuation, that is, Nlossfire = 0 and Tcov < Tcovmin, it is determined that the ignition energy of the ignition coil structure 20 can enable the engine 40 to stably burn in the lean combustion mode.

[0059] The engine ignition control method of the embodiments of the present application enables the magnetization time of the ignition coil structure 20 to change according to the engine speed information and the power supply voltage information under the current working condition through the above steps, and is adjusted according to the number of engine misfires and the torque fluctuation value fed back by the engine 40, so as to ensure that the ignition coil structure 20 can generate a high and stable ignition energy, thereby improving the ignition stability of the engine 40 in the lean combustion mode.

[0060] In this embodiment, when step S113 is performed; if it is no, then step S119 is performed.

[0061] Specifically, when it is determined whether the number of engine misfires Nlossfire is greater than or equal to the misfire threshold Nlossmax or whether the torque fluctuation value Tcov is greater than or equal to the preset upper limit of the fluctuation Tcovmax, if it is no, then it is further determined whether the number of engine misfires Nlossfire is equal to zero and whether the torque fluctuation value Tcov is less than the preset lower limit of the fluctuation Tcovmin. If Nlossfire = 0 and Tcov < Tcovmin, it is determined that the engine 40 stably burns under the current working condition.

[0062] In this way, by making two determinations on the number of engine misfires and the torque fluctuation value monitored in real time, the accuracy of determining that the engine 40 stably burns under the current working condition is improved.

[0063] In this embodiment, after step S117, when step S119 is executed, if the answer is no, then step S120 is executed to use the second magnetization time as the first magnetization time, and then step S115 is repeated.

[0064] Specifically, after step S117, when it is determined whether the number of engine misfires Nlossfire is equal to zero and whether the torque fluctuation value Tcov is less than the preset fluctuation lower limit Tcovmin, if the answer is no, then the second magnetization time Tdwell' is used as the first magnetization time Tdwell, and the preset increment time Δt is added to the first magnetization time Tdwell to obtain the second magnetization time Tdwell'. Then, the engine controller 10 controls the power supply 51 to supply power to the ignition coil structure 20 according to the value of Tdwell' again, and the engine controller 10 controls the ignition coil structure 20 to release ignition energy to the spark plug 30, and the spark plug 30 performs an ignition operation.

[0065] In this way, when the conditions set in step S119 are not met, the preset increment time Δt is sequentially accumulated on the basis of the first magnetization time Tdwell to increase the magnetization time, thereby increasing the ignition energy until the conditions set in step S119 are met, thus improving the ignition and combustion stability of the engine 40 in the lean burn mode.

[0066] In this embodiment, when step S113 is executed; if the answer is no, then step S119 is executed; if the answer is no, then step S115 is executed.

[0067] Specifically, when it is determined whether the number of engine misfires Nlossfire is greater than or equal to the misfire threshold Nlossmax or whether the torque fluctuation value Tcov is greater than or equal to the preset fluctuation upper limit Tcovmax, if the answer is no, then it is further determined whether the number of engine misfires Nlossfire is equal to zero and whether the torque fluctuation value Tcov is less than the preset fluctuation lower limit Tcovmin. If the conditions are not met and the second magnetization time is not obtained, then step S120 is skipped and step S115 is directly executed.

[0068] In this embodiment, before step S105, the engine ignition control method further includes the following steps: Step S101, determining the maximum ignition energy of the ignition coil structure 20.

[0069] Specifically, since the voltage range of the power supply 51 under normal operating conditions of the vehicle 1000 is generally 12V to 14V. If the bench test calibrates the ignition coil structure 20 by supplying power at the maximum supply voltage of 14V of the power supply 51, considering thermal equilibrium, at a voltage of 14V, the magnetization time is 5.14 ms, corresponding to an ignition energy of 290 mJ. Therefore, in this embodiment, a bench test is carried out based on the maximum supply voltage of 14V to determine that the maximum ignition energy of the ignition coil structure 20 is 290 mJ.

[0070] Step S104, obtaining a second relationship table based on the maximum ignition energy, where the second relationship table includes the engine speed, supply voltage, and maximum magnetization time.

[0071] Specifically, based on the maximum ignition energy, the relationship between the engine speed, supply voltage, and maximum magnetization time is determined through the bench test of the engine 40, and the relationship between the engine speed, supply voltage, and maximum magnetization time is converted into a second relationship table and stored in the engine controller 10.

[0072] When magnetizing the ignition coil structure 20, if the magnetization time is too long, the thermal equilibrium of the ignition coil structure 20 will be damaged, resulting in an increased probability of damage to the ignition coil structure 20. Therefore, when magnetizing the ignition coil structure 20, it is necessary to limit the magnetization time to reduce the probability of damage to the ignition coil structure 20.

[0073] The second relationship table of this embodiment is shown in Table 2. Based on the maximum ignition energy, when the engine speed increases by 200 r / min or 400 r / min, and the supply voltage of the ignition coil structure 20 is spaced 1V apart, the maximum magnetization time is preset. Within the maximum magnetization time range, the ignition coil structure 20 can reach thermal equilibrium. It should be noted that the operable voltage range of the ignition coil structure 20 is 6V - 16V. This embodiment focuses on the relationship between the engine speed, supply voltage, and maximum magnetization time within the range of 12V - 14V. The data outside 12V - 14V are all data obtained through tests considering abnormal situations.

[0074] Table 2 In some other embodiments, the engine speed can also be set to increase by 100 r / min as needed, and the supply voltage of the ignition coil structure 20 is spaced 0.5V apart to preset the maximum magnetization time, so as to obtain a more refined second relationship table. The embodiments of this application do not make specific limitations on this.

[0075] In some other embodiments, in addition to the engine speed, power supply voltage, and maximum magnetization time, the second relationship table may further include other information related to ensuring that the ignition coil structure 20 can reach thermal equilibrium, and the embodiments of the present application do not make specific limitations thereto.

[0076] In some other embodiments, step S104 and step S103 may be executed simultaneously, that is, the first relationship table and the second relationship table are obtained simultaneously based on the basic ignition energy, and the embodiments of the present application do not make specific limitations thereto.

[0077] After step S105, the engine ignition control method further includes the following steps: Step S108, obtaining the corresponding maximum magnetization time information according to the engine speed information, power supply voltage information, and the second relationship table.

[0078] After obtaining the engine speed information and power supply voltage information under the current working condition, the corresponding maximum magnetization time information can be obtained by retrieving the second relationship table, and the maximum magnetization time information is set as Tdwellmax. After step S115, the engine ignition control method further includes the following steps: Step S116, determining whether the second magnetization time is less than or equal to the maximum magnetization time information.

[0079] If it is yes, then step S117 is executed.

[0080] Specifically, after adding the preset increment time Δt to the first magnetization time Tdwell to obtain the second magnetization time Tdwell', it is determined whether the value of Tdwell' is less than or equal to Tdwellmax. When Tdwell'≤Tdwellmax, the engine controller 10 controls the power supply 51 to magnetize the ignition coil structure 20 according to the value of Tdwell'. In this way, it can be ensured that the ignition coil structure 20 always satisfies thermal equilibrium during the magnetization time, thereby reducing the probability of damage to the ignition coil structure 20.

[0081] In this embodiment, after step S100, the engine ignition control method further includes the following steps: Step S102, determining the target air-fuel ratio of the engine 40 under various working conditions based on the basic ignition energy.

[0082] Such as Figure 2As shown, the target air-fuel ratio is set to λ. When determining the target air-fuel ratio of the engine 40 under various operating conditions, according to the basic ignition energy (such as the basic ignition energy = 240 mJ), the engine 40 is swept through each speed-power point in the bench test of the engine 40. When the engine 40 stably burns (such as COV < 3 N.m) and the fuel consumption is at the lowest point, the target air-fuel ratio λ for stable combustion under this operating condition is determined, and thus the relationship between the engine power point (load point) and the target air-fuel ratio λ can be obtained. Among them, the air-fuel ratio in the cold start and low load conditions is relatively large, and in the high load condition, to ensure the power generation power and prevent knocking, the mixture gas is enriched, that is, the target air-fuel ratio is reduced. This relationship is converted into a corresponding table and stored in the engine controller 10 so that the engine 40 can look up the corresponding target air-fuel ratio λ at each operating point subsequently.

[0083] In some other embodiments, steps S102, S103, and S104 can also be executed simultaneously, that is, based on the basic ignition energy, the first relationship table and the second relationship table are obtained simultaneously, and the target air-fuel ratio of the engine 40 under various operating conditions is determined. The embodiments of the present application do not make specific limitations on this.

[0084] When step S116 is executed, if the answer is no, then step S123 is executed to obtain the target air-fuel ratio under the current operating condition and use the target air-fuel ratio as the current air-fuel ratio.

[0085] Specifically, the engine controller 10 obtains the engine power point under the current operating condition through the crankshaft position sensor 60, retrieves the corresponding target air-fuel ratio λ of the corresponding table according to the engine power point, and uses the target air-fuel ratio λ as the current air-fuel ratio λ1.

[0086] Step S125, on the basis of the current air-fuel ratio, control the engine 40 to reduce the air-fuel ratio according to a preset decrement.

[0087] Since high-energy ignition will accelerate the aging of the spark plug 30, such as electrode erosion and increased spark gap, higher ignition energy is required at this time. If the second magnetization time has exceeded the maximum magnetization time information under the corresponding operating condition, to avoid damage to the ignition coil structure 20 and ensure stable combustion of the engine 40 under the current operating condition, the mixture gas needs to be enriched at this time, that is, the current air-fuel ratio λ1 is reduced.

[0088] Set the preset decrement to Δp. The engine controller 10 controls the engine 40 to reduce the air-fuel ratio according to the preset decrement Δp on the basis of the current air-fuel ratio λ1, that is, the air-fuel ratio of the engine 40 after reduction is λ1 - Δp. In this way, the mixture gas entering the engine 40 is enriched, and the ignition energy required for the spark plug 30 during ignition is reduced, thereby improving the ignition and combustion stability of the engine 40.

[0089] In this embodiment, the value of Δp can be 0.1. In some other embodiments, the value of Δp can also be 0.05 or 0.2. The embodiments of the present application do not make specific limitations thereto.

[0090] Step S127: Determine whether the number of engine 40 misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit.

[0091] If so, it is determined that the engine 40 stably burns under the current working condition.

[0092] Specifically, after the engine controller 10 controls the engine 40 to reduce the air-fuel ratio by a preset decrement Δp based on the current air-fuel ratio λ1, it is determined whether the number of engine misfires Nlossfire is equal to zero or the torque fluctuation value Tcov is less than the preset fluctuation lower limit Tcovmin. If so, step S121 is executed.

[0093] In this embodiment, after step S125, when step S127 is executed; if not, step S125 is repeatedly executed.

[0094] Specifically, after the engine controller 10 controls the engine 40 to reduce the air-fuel ratio by a preset decrement Δp based on the current air-fuel ratio λ1, if the conditions set in step S127 are still not satisfied, the reduced air-fuel ratio is used as the current air-fuel ratio λ1, and the engine controller 10 controls the engine 40 to reduce the air-fuel ratio by the preset decrement Δp again based on the current air-fuel ratio λ1 until the conditions set in step S127 are satisfied.

[0095] In this way, the preset decrement Δp can be set to be small, and the air-fuel ratio of the engine 40 is gradually reduced to test whether the conditions for the stable combustion of the engine 40 are met, so as to achieve refined control and avoid increasing fuel consumption by enriching the mixture gas too much at one time.

[0096] In this embodiment, after step S125, when step S127 is executed; if so, before the step of determining that the engine 40 stably burns under the current working condition, step S128 is executed to send an alarm message for replacing the spark plug 30.

[0097] Specifically, since the second magnetization time has increased to the maximum magnetization time information under the corresponding working condition, and the number of engine misfires Nlossfire is still not equal to zero and the torque fluctuation value Tcov is still not less than the preset fluctuation lower limit Tcovmin, it indicates that the spark plug 30 has aged and requires a greater ignition energy. At this time, a replacement message for the spark plug 30 is sent to facilitate the driver to replace the spark plug 30 in a timely manner.

[0098] In some other embodiments, if after step S127, the step of determining the stable combustion of the engine 40 under the current working condition and step S121 belong to two completely independent steps, then after step S125, when step S127 is executed; if it is yes, step S128 may also be executed after the step of determining the stable combustion of the engine 40 under the current working condition. The embodiments of the present application do not make specific limitations on this.

[0099] In summary, through the above steps, the engine ignition control method of the embodiments of the present application makes the magnetization time of the ignition coil structure 20 change according to the engine speed information and the power supply voltage information under the current working condition, and adjusts according to the engine misfire count and the torque fluctuation value fed back by the engine 40, thereby ensuring that the ignition coil structure 20 can generate a high and stable ignition energy, and further improving the ignition stability of the engine 40 in the lean combustion mode. In addition, by controlling the magnetization time of the ignition coil structure 20 within the maximum magnetization time information, the ignition coil structure 20 can reach thermal equilibrium, thereby reducing the probability of damage to the ignition coil structure 20. Further, when the magnetization time has increased to the maximum magnetization time information corresponding to the working condition, and the engine misfire count is still not equal to zero and the torque fluctuation value is still not less than the preset fluctuation lower limit, by gradually reducing the air-fuel ratio of the engine 40, the ignition energy required by the spark plug 30 is reduced, so that the engine 40 can stably burn, thereby further improving the ignition and combustion stability of the engine 40 in the lean combustion mode.

[0100] Please refer to Figure 3 simultaneously, the embodiments of the present application provide an engine ignition control system 100, including an engine controller 10, an ignition coil structure 20, a spark plug 30 and an engine 40.

[0101] The ignition coil structure 20 is provided on the engine 40. The spark plug 30 is provided on the engine 40 and connected to the ignition coil structure 20. The engine controller 10 is electrically connected to the engine 40 and the ignition coil structure 20, and the engine controller 10 is used to load and execute the engine ignition control method as described above.

[0102] The engine ignition control system 100 of the embodiments of the present application improves the stability of controlling the ignition of the engine 40 by implementing the above engine ignition control method.

[0103] In this embodiment, the engine ignition control system 100 further includes a battery management module 50, a knock sensor 70, and a crankshaft position sensor 60. The engine controller 10 is electrically connected to the battery management module 50, the knock sensor 70, and the crankshaft position sensor 60. The engine controller 10 obtains the power supply voltage information under the current working condition through the battery management module 50. The engine controller 10 obtains the engine speed information and the torque fluctuation value under the current working condition through the crankshaft position sensor 60. The engine controller 10 obtains the engine misfire count in real time through the knock sensor 70.

[0104] Please refer to Figure 4 , in this embodiment, the ignition coil structure 20 includes two ignition coils 21 and an output terminal 22. The two ignition coils 21 are arranged in parallel, and the output ends 2121 of the two ignition coils 21 are both connected to the output terminal 22. The output terminal 22 is used to connect to the spark plug 30.

[0105] By arranging the two ignition coils 21 in parallel and connecting them to an output terminal 22 in the ignition coil structure 20 of this embodiment, the ignition energy output by the ignition coil structure 20 is twice that of a single ignition coil, so as to quickly and stably cooperate with the spark plug 30 to ignite the leaner mixture gas in the lean burn mode, thereby improving the ignition stability.

[0106] In this embodiment, each ignition coil 21 includes a support skeleton (not shown in the figure), a primary coil 211, and a secondary coil 212. The support skeleton can be an iron core. The primary coil 211 and the secondary coil 212 are both wound around the support skeleton. Energy transfer is achieved between the primary coil 211 and the secondary coil 212 through electromagnetic induction. The number of turns of the primary coil 211 is less than that of the secondary coil 212. The primary coil 211 includes a first end 2111 and a second end 2112. The first end 2111 is used to connect to the power supply 51. The secondary coil 212 includes an output end 2121 and a ground end 2122. The ground end 2122 is grounded, and the output end 2121 is connected to the output terminal 22.

[0107] When the ignition coil 21 ignites, the power supply 51 magnetizes the primary coil 211. The voltage of the secondary coil 212 instantaneously increases between the primary coil 211 and the secondary coil 212 through electromagnetic induction. Multiple secondary coils 212 release ignition energy to the spark plug 30 through the output terminal 22, and the spark plug 30 realizes the ignition operation. In this way, the structure of the ignition coil 21 is simple and the ignition stability is improved.

[0108] In this embodiment, each ignition coil 21 further includes a triode 213. The second end 2112 is connected to the collector of the triode 213. The base of the triode 213 is used to connect to the engine controller 10, and the emitter of the triode 213 is grounded.

[0109] When the engine controller 10 controls the ignition coil 21 to ignite, the engine controller 10 first outputs a high level, the collector and emitter of the triode 213 are turned on, an electric circuit is formed in the primary coil 211, and the power supply 51 magnetizes the primary coil 211. The duration of the high level is controlled by the magnetization time of the ignition coil 21. When the magnetization time ends, the engine controller 10 outputs a low level. At this time, the collector and emitter of the triode 213 are simultaneously disconnected, and the electric circuit of the primary coil 211 is open. Due to the sudden change of the current in the primary coil 211, the magnetic field changes rapidly, which is coupled to the secondary coil 212 through the iron core. According to Faraday's law of electromagnetic induction, a high voltage of tens of thousands of volts will be induced in the secondary coil 212 at the same time. The high voltage jumps through the gap of the spark plug 30 to ignite the combustible mixture. In this way, by setting the triode 213, it is convenient for the engine controller 10 to accurately control the magnetization time of the primary coil 211, thereby accurately controlling the ignition time and ignition energy of the ignition coil 21.

[0110] In this embodiment, each ignition coil 21 further includes a series-connected anti-back diode 214 and a suppression resistor 215. The positive electrode of the anti-back diode 214 is connected to one end of the suppression resistor 215, the negative electrode of the anti-back diode 214 is connected to the output terminal 2121, and the other end of the suppression resistor 215 is connected to the output terminal 22.

[0111] When the secondary coil 212 generates a high voltage, if the spark plug 30 fails to discharge normally (for example, the gap of the spark plug 30 is too large or damaged), the high voltage in the secondary coil 212 may be transmitted backward to the primary coil 211, thereby causing damage to the control circuit. By setting the anti-back diode 214, the high voltage in the secondary coil 212 is prevented from being transmitted backward to the primary coil 211, thereby reducing the probability of damage to the control circuit, and further improving the service life of the control circuit. In addition, when the secondary coil 212 generates a high voltage, the current will discharge through the gap of the spark plug 30. If the gap of the spark plug 30 is too small or short-circuited, the current may be too large, resulting in damage to the spark plug 30 and the ignition coil 21. By setting the suppression resistor 215 to limit the magnitude of the current, it not only ensures that the spark plug 30 generates sufficient spark energy, but also avoids the instability of the spark generated by the spark plug 30 due to excessive current, thereby improving the ignition stability of the ignition coil structure 20 and the service life of the spark plug 30 and the ignition coil 21.

[0112] Please refer to Figure 5 , Figure 5It is a schematic diagram comparing the relationship between the discharge duration and discharge current of the ignition coil structure 20 of this embodiment and the secondary coil 212 of the existing single ignition coil. For example, if the engine 40 is to achieve an air-fuel ratio greater than or equal to 2.2 (i.e., lean combustion), the lean mixed combustible gas needs to be reliably ignited under the condition that the discharge current is greater than 100 mA. The ignition coil structure 20 of this embodiment is superior to the single ignition coil in terms of the current intensity released per unit time and the duration of igniting the mixture gas.

[0113] Please refer to Figure 6 , this application embodiment also provides a vehicle 1000, including the engine ignition control system 100 as described above.

[0114] The vehicle 1000 of this application embodiment improves the ignition stability of the engine 40 in the lean burn mode by setting the above-mentioned engine ignition control system 100 that implements the above-mentioned engine ignition control method.

[0115] For those skilled in the art, it is obvious that this application is not limited to the details of the above-mentioned exemplary embodiments, and without departing from the spirit or basic characteristics of this application, this application can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of this application is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in this application.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not restrictive. Although this application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of this application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of this application.

Claims

1. An engine ignition control method, characterized in that, Including: Determine the basic ignition energy of the ignition coil structure; Obtain a first relationship table based on the basic ignition energy, where the first relationship table includes engine speed, supply voltage, and basic magnetization time; Obtain the engine speed information and supply voltage information under the current working condition; Obtain the corresponding basic magnetization time information according to the engine speed information, the supply voltage information, and the first relationship table, and use the basic magnetization time information as the first magnetization time; Control the power supply to supply power to the ignition coil structure according to the first magnetization time and control the ignition coil structure to release ignition energy; Monitor the engine misfire count and torque fluctuation value; Judge whether the engine misfire count is greater than or equal to the misfire threshold or whether the torque fluctuation value is greater than or equal to the preset fluctuation upper limit; If so, add a preset increment time to the first magnetization time to obtain a second magnetization time; Control the power supply to supply power to the ignition coil structure according to the second magnetization time and control the ignition coil structure to release ignition energy; Judge whether the engine misfire count is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit, where the preset fluctuation lower limit is less than or equal to the preset fluctuation upper limit; If so, determine that the engine burns stably under the current working condition.

2. The engine ignition control method according to claim 1, characterized in that, When judging whether the engine misfire count is greater than or equal to the misfire threshold or whether the torque fluctuation value is greater than or equal to the preset fluctuation upper limit; If not, execute the step of judging whether the engine misfire count is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit.

3. The engine ignition control method according to claim 1, characterized in that, After the step of controlling the power supply to supply power to the ignition coil structure according to the second magnetization time and controlling the ignition coil structure to release ignition energy, when judging whether the engine misfire count is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; If not, use the second magnetization time as the first magnetization time, and repeat the step of adding a preset increment time to the first magnetization time to obtain a second magnetization time.

4. The engine ignition control method according to any one of claims 1-3, characterized in that, Before the step of obtaining the engine speed information and supply voltage information under the current working condition, the method further includes: Determine the maximum ignition energy of the ignition coil structure; Obtain a second relationship table based on the maximum ignition energy, where the second relationship table includes the engine speed, the supply voltage, and the maximum magnetization time; After the step of obtaining the engine speed information and supply voltage information under the current working condition, the method further includes: Obtain the corresponding maximum magnetization time information according to the engine speed information, the supply voltage information, and the second relationship table; After the step of adding a preset increment time to the first magnetization time to obtain a second magnetization time, the method further includes: Judge whether the second magnetization time is less than or equal to the maximum magnetization time information; If so, execute the step of controlling the power supply to supply power to the ignition coil structure according to the second magnetization time and controlling the ignition coil structure to release ignition energy.

5. The engine ignition control method according to claim 4, characterized in that After the step of determining the basic ignition energy of the ignition coil structure, the method further includes: Based on the basic ignition energy, determining the target air-fuel ratio of the engine under various operating conditions; When it is judged whether the second magnetization time is less than or equal to the maximum magnetization time information; If not, obtaining the target air-fuel ratio under the current operating condition and using the target air-fuel ratio as the current air-fuel ratio; Controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio; Judging whether the number of engine misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; If so, determining that the engine stably burns under the current operating condition.

6. The engine ignition control method according to claim 5, characterized in that, After the step of controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio, when it is judged whether the number of engine misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; If not, repeating the step of controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio.

7. The engine ignition control method according to claim 5, characterized in that, After the step of controlling the engine to decrease the air-fuel ratio by a preset decrement based on the current air-fuel ratio, when it is judged whether the number of engine misfires is equal to zero and whether the torque fluctuation value is less than the preset fluctuation lower limit; If so, sending a spark plug replacement alarm message before or after the step of determining that the engine stably burns under the current operating condition.

8. An engine ignition control system, characterized in that, Including: An engine; An ignition coil structure provided on the engine; A spark plug provided on the engine and connected to the ignition coil structure; An engine controller electrically connected to the engine and the ignition coil structure, and configured to load and execute the engine ignition control method according to any one of claims 1-7.

9. The engine ignition control system according to claim 8, wherein, The ignition coil structure includes two ignition coils and an output terminal. The two ignition coils are arranged in parallel, and the output ends of the two ignition coils are both connected to the output terminal, and the output terminal is used to connect to the spark plug.

10. A vehicle, characterized in that, Including the engine ignition control system according to claim 9.

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