Ignition coil protection control method, storage medium, engine ignition system, and vehicle

Abstract

An ignition coil protection control method, comprising: measuring the temperature of an ignition module; if the temperature of the ignition module is greater than or equal to a first set temperature value, reducing the charging duration of an ignition coil until the temperature of the ignition module is less than the first set temperature value; and if the temperature of the ignition module is less than the first set temperature value, determining the charging duration of the ignition coil on the basis of an engine speed, the value of direct current voltage, and a preset mapping relationship. Also disclosed are a storage medium, an engine ignition system, and a vehicle.

Description

Ignition coil protection control methods, storage media, engine ignition system and vehicle

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202410915599.5, filed on July 9, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of ignition coil technology, and in particular to an ignition coil protection and control method, a storage medium, an engine ignition system, and a vehicle. Background Technology

[0004] Ignition energy refers to the energy released by the high-voltage discharge between the spark plug electrodes in an engine. It is the integral of the product of the voltage and current acting between the spark plug electrodes over time during the secondary high-voltage discharge of the system. The ignition system must ensure that it provides the engine with sufficient energy to ignite the combustible mixture in the engine combustion chamber under different operating conditions. If the ignition energy is too low, the engine's power and torque will decrease, fuel consumption will increase, emissions will worsen, and it may even cause the engine to stall.

[0005] Ignition coils are crucial components of automotive engine ignition systems, delivering high voltage to the spark plugs to ignite the air-fuel mixture. With automotive engines now trending towards higher compression ratios and higher thermal efficiency, high-thermal-efficiency hybrid engines have emerged. Lean-burn conditions place even greater demands on engine ignition performance. To achieve better ignition stability, ignition coils with higher ignition energy are needed. High-energy ignition coils have more turns and generate more heat; however, the heat generated by high-energy ignition coils can lead to overheating of the ignition module.

[0006] To protect the ignition module, the charging time of the existing ignition coil is set to a fixed charging time to prevent the heat dissipated by the ignition coil from damaging the ignition module. However, this method cannot give full play to the advantage of the high ignition energy of the high-energy ignition coil. Summary of the Invention

[0007] The main objective of this application is to provide an ignition coil protection control method, which aims to provide an ignition module that protects high-energy ignition coils.

[0008] To achieve the above objectives, this application proposes an ignition coil protection control method, which is applied to an engine ignition system. The engine ignition system includes an ignition module and an ignition coil. A first terminal of the ignition module is connected to a first terminal of the primary coil of the ignition coil, and a second terminal is grounded. A DC voltage is connected to the second terminal of the primary coil. A first terminal of the secondary coil of the ignition coil is connected to a spark plug.

[0009] The ignition coil protection control method includes:

[0010] Detect the temperature of the ignition module;

[0011] If the temperature of the ignition module is higher than or equal to the first set temperature value, the charging time of the ignition coil is reduced until the temperature of the ignition module is lower than the first set temperature value.

[0012] In one embodiment, after the step of waiting until the temperature of the ignition module is lower than a first set temperature value, the method further includes:

[0013] If the temperature of the ignition module is lower than the first set temperature value, the charging time of the ignition coil is determined according to the engine speed, the value of the DC voltage and the preset mapping relationship.

[0014] In one embodiment, the step of reducing the charging time of the ignition coil specifically includes:

[0015] Obtain the engine's EGR rate;

[0016] The minimum ignition energy is determined based on the EGR rate.

[0017] The minimum charging time is determined based on the minimum ignition energy, and the charging time of the ignition coil is reduced to the minimum charging time.

[0018] In one embodiment, the first set temperature value is 175°C.

[0019] This application also proposes a storage medium storing an ignition coil protection control program, which, when executed by a processor, implements the steps of the ignition coil protection control method as described above.

[0020] This application also proposes an engine ignition system, which includes: an ignition module, a control module, and an ignition coil;

[0021] The control module is connected to the ignition module; the first end of the ignition module is connected to the first end of the primary coil of the ignition coil, and the second end is grounded; the second end of the primary coil is connected to a DC voltage; the first end of the secondary coil of the ignition coil is connected to the spark plug.

[0022] The ignition module includes a temperature sensor, a power switch, and a control circuit.

[0023] The temperature sensor is connected to the control module and is used to detect the temperature of the ignition module and output it to the control module.

[0024] The first terminal of the power switch is connected to the first terminal of the primary coil, and the second terminal is grounded.

[0025] The first terminal of the control circuit is connected to the control module, and the second terminal is connected to the control terminal of the power switch; the control circuit is used to control the power switch to be turned on according to the ignition signal output by the control module.

[0026] The control circuit is also connected to the temperature sensor; the control circuit is also used to control the power switch to turn off when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the ignition module is higher than a first set temperature value.

[0027] In one embodiment, the control circuit is used to control the power switch to be turned off in a soft-shutdown manner when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the ignition module is higher than a first set temperature value.

[0028] In one embodiment, the power switch is an IGBT transistor;

[0029] The temperature sensor is used to detect the temperature of the IGBT tube and output it to the control module and the control circuit.

[0030] The control circuit is also used to control the IGBT to turn off in a soft-shutdown manner when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the IGBT is higher than a first set temperature value.

[0031] In one embodiment, the engine ignition system further includes:

[0032] An anomaly alert module is connected to both the control circuit and the vehicle's engine malfunction indicator light.

[0033] The control circuit is also used to output an abnormal signal to the abnormality reminder module when the duration of the ignition signal output by the control module exceeds a first preset duration;

[0034] The anomaly alert module records the number of anomaly signals received; the anomaly alert module is also used to illuminate the engine fault indicator light and clear the count value to zero when the count value exceeds a preset number.

[0035] In one embodiment, the control circuit includes: a first resistor, a second resistor, a main control unit, and a first Zener diode;

[0036] The control module is connected to the first terminal of the first resistor, the cathode of the first Zener diode, and the first terminal of the second resistor;

[0037] The second end of the first resistor is connected to the anode of the first Zener diode, the emitter of the IGBT, and the second end of the main control unit;

[0038] The second end of the second resistor is connected to the first end of the main control unit and the gate of the IGBT transistor.

[0039] In one embodiment, the ignition coil further includes: a second Zener diode;

[0040] The anode of the second Zener diode is connected to the second end of the secondary coil, and the cathode is connected to the second end of the primary coil.

[0041] This application also proposes a vehicle that includes the engine ignition system or the storage medium described above.

[0042] This application discloses an ignition coil protection control method, a storage medium, an engine ignition system, and a vehicle. The ignition coil protection control method includes: detecting the temperature of the ignition module; if the temperature of the ignition module is higher than or equal to a first preset temperature value, reducing the charging time of the ignition coil until the temperature of the ignition module is lower than the first preset temperature value; if the temperature of the ignition module is lower than the first preset temperature value, determining the charging time of the ignition coil based on the engine speed, the value of the DC voltage, and a preset mapping relationship. By detecting the temperature of the ignition module and adjusting the charging time of the ignition coil accordingly, this application can output the highest ignition energy during normal operation, and output a smaller ignition energy that meets the engine ignition requirements when the ignition module temperature is higher than or equal to the first preset temperature, thereby reducing the ignition module temperature and preventing overheating damage. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0044] Figure 1 is a structural schematic diagram of an embodiment of the engine ignition system of this application;

[0045] Figure 2 is a schematic diagram of ignition signal controlling ignition coil operation according to an embodiment of the ignition coil protection control method of this application;

[0046] Figure 3 shows the maximum charging time under different operating conditions of an embodiment of the ignition coil protection control method of this application.

[0047] Figure 4 is a flowchart illustrating an embodiment of the ignition coil protection control method of this application;

[0048] Figure 5 is a schematic diagram of the working principle and energy of the ignition coil in an embodiment of the ignition coil protection and control method of this application.

[0049] Figure 6 is a schematic diagram of the soft shutdown action correspondence of an embodiment of the ignition coil protection control method of this application;

[0050] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Embodiments of the present invention

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0052] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0053] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0055] The ignition coil plays a crucial role in a car engine. Its main function is to convert the low-voltage electrical energy provided by the car battery into high-voltage electrical energy, which is then used to generate a spark with sufficient energy in the spark plug to ignite the fuel-air mixture compressed in the engine cylinders. This conversion process is achieved through the principle of electromagnetic induction, involving a primary coil and a secondary coil. The primary coil is typically made of thicker enameled wire, while the secondary coil is made of thinner enameled wire, with a high turns ratio to ensure the generation of high voltage. When the primary coil of the ignition coil is energized, it generates a strong magnetic field. When the circuit is suddenly interrupted, this magnetic field decays rapidly, causing the secondary coil to induce a voltage of tens of thousands of volts. This high-voltage electricity is then delivered to the spark plug, igniting the fuel and driving the engine.

[0056] The charging time of an ignition coil refers to the period during which current flows through the primary coil of the ignition coil and stores energy in the ignition system. This process is typically controlled by the ignition switch. The duration and magnitude of the current determine the strength of the magnetic field in the primary coil, which in turn affects the energy of the high-voltage electricity generated in the secondary coil. Controlling the charging time is crucial to ensuring that the ignition coil can generate a spark with sufficient energy, which directly relates to the engine's ignition efficiency and performance.

[0057] Currently, there are two main ways to change ignition energy: one is to regulate ignition energy by altering the energy stored in the ignition coil. With the coil constant, the energy stored in the coil is solely determined by the primary current; an increase in current increases energy storage, and vice versa. The primary current increases exponentially, but after 3τ, the current essentially stops increasing and has no effect on storing magnetic energy. Therefore, the primary current can be changed by cutting it off before it reaches a stable value. However, this method is only effective before the primary current reaches a stable value.

[0058] Another approach is to use a multiple ignition system, which generates multiple electric sparks at a single ignition moment by controlling the on / off state of the primary current. This method not only controls the ignition energy by controlling the number of ignitions, but also ensures that the energy required for subsequent ignition reactions is replenished in a timely manner by generating multiple electric sparks at a single ignition moment. This effectively shortens the ignition prolongation period, improves the combustion efficiency of the air-fuel mixture, and consequently shortens the duration of high-temperature combustion, reducing losses such as high-temperature heat dissipation, thereby improving the engine's thermal efficiency.

[0059] Compared to traditional ignition coils, high-energy ignition coils are typically manufactured using more advanced technologies and materials, providing stronger ignition capability and higher ignition energy. This helps improve combustion efficiency, increase power output, and reduce emissions. However, high-energy ignition coils generate more heat. While existing technologies using a fixed charging time can protect the ignition module, they cannot fully utilize the superior ignition capability of high-energy ignition coils.

[0060] This application proposes an ignition coil protection control method, aiming to provide a control method that leverages the strong ignition capability of high-energy ignition coils.

[0061] This application discloses an ignition coil protection control method, which is applied to an engine ignition system. The engine ignition system includes an ignition module, a control module, and an ignition coil. The control module is connected to the ignition module. A first terminal of the ignition module is connected to a first terminal of the primary coil of the ignition coil, and a second terminal is grounded. A DC voltage is applied to the second terminal of the primary coil. A first terminal of the secondary coil of the ignition coil is connected to a spark plug.

[0062] The ignition coil protection control method includes:

[0063] Detect the temperature of the ignition module;

[0064] If the temperature of the ignition module is higher than or equal to the first set temperature value, the charging time of the ignition coil is reduced until the temperature of the ignition module is lower than the first set temperature value.

[0065] It should be noted that the execution entity in the control method disclosed in this application is the control module; depending on the specific scenario, the control module can be a vehicle controller or an engine controller. The control module may include controllers such as MCUs, FPGAs, or SOCs.

[0066] Referring to Figure 1, which is a structural schematic diagram of an embodiment of the engine ignition system, the control module outputs control commands to the ignition module to control the ignition module to turn on or off the grounding path of the primary coil, thereby realizing the charging or discharging of the ignition coil. During the charging process of the ignition coil, the current flowing through the primary coil passes through the ignition module; the ignition module includes a power switch, which heats up when current flows through it, and whether the power switch is damaged directly affects whether the ignition coil can charge and discharge normally.

[0067] Alternatively, the DC voltage can be provided by a battery, as shown in Figure 1; the DC voltage can also be provided by the engine ignition system or by a vehicle equipped with an engine ignition system. The source of the DC voltage is not limited, as long as it can output DC voltage before engine ignition, and the value of the DC voltage needs to be greater than the minimum ignition voltage designed for the engine ignition system.

[0068] Referring to Figure 2, which is a schematic diagram of the control module outputting an ignition signal to control the ignition coil, the control module outputs an ignition signal to the ignition module. The ignition module connects the primary coil to ground, increasing the current flowing through the primary coil. After the control module stops outputting the ignition signal, the ignition module disconnects the primary coil from ground, and a voltage is output from the secondary coil. As shown in Figure 2, the ignition signal output by the control module is a square wave. During the duration of the square wave signal, the ignition module connects the primary coil to ground, and a primary current flows through the primary coil. The primary current increases with the duration of the ignition signal. When the ignition signal disappears, the ignition module disconnects the primary coil from ground, and the primary current becomes zero. It should be noted that the ignition coil is essentially a transformer; the primary coil is the primary side, and the secondary coil is the secondary side. After the connection is broken, the secondary coil of the ignition coil outputs a negative high voltage, as shown by the secondary voltage curve in the figure.

[0069] The temperature of the ignition module is obtained. It's easy to understand that when the ignition coil is charging, current flows through both the ignition module and the ignition coil, generating heat. The ignition coil can withstand temperatures higher than the maximum operating temperature of the ignition module. In practical applications, the ignition coil and the ignition module are located close to each other, and the heat from the ignition coil is transferred to the ignition module via thermal transfer. Furthermore, the normal operation of the ignition system requires the ignition module and ignition coil to operate normally. Since the maximum operating temperature of the ignition coil is higher than that of the ignition module, the ignition energy of the ignition coil can be maximized, provided the temperature of the ignition module is within a safe range, to achieve better engine ignition efficiency.

[0070] The ignition module may be equipped with a temperature sensor or a thermistor and a corresponding voltage divider circuit for detecting the temperature of the ignition module. Alternatively, the control module may include a temperature sensor or a thermistor for detecting the temperature of the ignition module. In particular, the ignition module may be in a packaged form.

[0071] If the temperature of the ignition module is higher than or equal to the first set temperature value, the charging time of the ignition coil is reduced until the temperature of the ignition module is lower than the first set temperature value.

[0072] The time it takes for current to flow through the primary coil of the ignition coil is the charging time of the ignition coil, which is also the duration for which the control module outputs the ignition signal under normal conditions. The temperature of the ignition module rises during this charging time. The first set temperature value is determined by the R&D personnel; specifically, the first set temperature is lower than the maximum operating temperature of the power switch in the ignition module. It should be noted that the higher the ignition energy released by the ignition coil, the longer the charging time of the ignition coil, the higher the temperature of the ignition module, and the faster its temperature rises. It is readily apparent that the higher the ignition energy released by the ignition coil, the higher the specific value corresponding to the first set temperature needs to be. Furthermore, the magnitude of the current flowing through the primary coil of the ignition coil affects the voltage output of the secondary coil; specifically, the two are positively correlated.

[0073] The ignition module can dissipate heat by transferring heat to the outside. Preferably, the device with the engine ignition system can be equipped with air-cooling or water-cooling equipment to cool the ignition module.

[0074] The temperature trend of the ignition module depends on the comparison between the heat generated and received by the ignition module and the heat it dissipates. If the heat dissipation is greater, the ignition module temperature decreases; if the heat dissipation is less, the ignition module temperature increases. Furthermore, the charging time of the ignition coil alters this comparison. It is readily apparent that there exists a critical time; when the charging time of the ignition coil exceeds this critical time, the ignition module temperature increases; when the charging time of the ignition coil is less than this critical time, the ignition module temperature decreases.

[0075] After determining that the temperature of the ignition module is higher than or equal to a first set temperature value, in order to reduce the temperature of the ignition module and avoid overheating damage, the charging time of the ignition coil is reduced until the temperature of the ignition module is lower than the first set temperature value. The charging time is related to the duration of the ignition signal output by the control module; correspondingly, the duration of the ignition signal is reduced. It should be noted that the reduced charging time must ensure that the ignition energy output by the ignition coil can successfully ignite the fuel-air mixture in the cylinder. In one embodiment, the charging time of the ignition coil can be gradually reduced, with the step size determined based on the difference between the temperature of the ignition module and the first set temperature value; specifically, the larger the difference, the larger the step size. In another embodiment, after the temperature of the ignition module is higher than or equal to the first set temperature value, the charging time can be adjusted to a first preset time; the first preset time meets the ignition energy requirements for the ignition coil to ignite the fuel-air mixture. The first preset time is determined by the researchers.

[0076] To maximize the ignition energy output from the ignition coil, specifically, the ignition coil is a high-energy coil. In one embodiment of this application, after the step of waiting until the temperature of the ignition module is lower than a first set temperature value, the method further includes:

[0077] If the temperature of the ignition module is lower than the first set temperature value, the charging time of the ignition coil is determined according to the engine speed, the value of the DC voltage and the preset mapping relationship.

[0078] A charging time that is too short for the ignition coil will result in poor spark plug ignition, while a charging time that is too long will lead to energy waste and heat buildup. The ignition energy released by the ignition coil is used to ignite the fuel-air mixture. The ignition energy required to ignite the fuel-air mixture in the cylinder is related to the engine speed. Specifically, the two are inversely proportional. The DC voltage applied across the primary coil affects the current flowing through the primary coil when the ignition module connects the primary coil to ground, thus affecting the energy accumulated by the ignition coil during the charging time. However, since an excessively long charging time leads to energy waste and heat buildup, it is necessary to determine an appropriate charging time that can output high ignition energy. In this embodiment, researchers can determine the maximum charging time of the ignition coil under different engine speeds and DC voltages based on experimental data and establish a preset mapping relationship.

[0079] Then, the charging time of the ignition coil can be determined based on the engine speed, the DC voltage value, and a preset mapping relationship. Referring to Figure 3, which shows the maximum allowable charging time of a high-energy ignition coil under different operating conditions in this embodiment, the energizing time in the figure is the charging time; the power supply voltage represents the value of the DC voltage. As shown in Figure 3, the higher the power supply voltage, the shorter the energizing time; the higher the engine speed, the shorter the energizing time.

[0080] This application discloses an ignition coil protection control method, a storage medium, an engine ignition system, and a vehicle. The ignition coil protection control method includes: detecting the temperature of the ignition module; if the temperature of the ignition module is higher than or equal to a first preset temperature value, reducing the charging time of the ignition coil until the temperature of the ignition module is lower than the first preset temperature value; if the temperature of the ignition module is lower than the first preset temperature value, determining the charging time of the ignition coil based on the engine speed, the value of the DC voltage, and a preset mapping relationship. By detecting the temperature of the ignition module and adjusting the charging time of the ignition coil accordingly, this application can output the highest ignition energy during normal operation, and output a smaller ignition energy that meets the engine ignition requirements when the ignition module temperature is higher than or equal to the first preset temperature, thereby reducing the ignition module temperature and preventing overheating damage.

[0081] Referring to Figure 4, in one embodiment of this application, the step of reducing the charging time of the ignition coil specifically includes:

[0082] Step S110: Obtain the engine's EGR rate;

[0083] Step S120: Determine the minimum ignition energy based on the EGR rate;

[0084] Step S130: Determine the minimum charging time based on the minimum ignition energy, and reduce the charging time of the ignition coil to the minimum charging time.

[0085] While reducing the ignition coil charging time is necessary to lower the ignition module temperature, it's crucial to ensure the ignition coil outputs sufficient ignition energy to ignite the fuel-air mixture, thus affecting engine operation. EGR (Exhaust Gas Recirculation) rate refers to the ratio of recirculated exhaust gas to the total intake air volume. Properly controlling the EGR rate is vital for reducing nitrogen oxide (NOx) emissions and improving engine combustion efficiency. EGR reduces NOx formation by lowering in-cylinder combustion temperature, but may also affect combustion speed and stability. At higher EGR rates, combustion time may increase, but optimizing ignition timing can maintain good combustion efficiency and stability. A complex interplay exists between EGR rate, in-cylinder combustion conditions, and ignition energy. Higher EGR rates may require higher ignition energy to ensure stable combustion, especially at high EGR rates. High-energy ignition modes effectively reduce the initial core formation period at high EGR rates, facilitating flame core formation and improving engine combustion stability. Simultaneously, optimizing ignition energy improves combustion efficiency, reduces emissions, and enhances overall engine performance.

[0086] Therefore, the minimum ignition energy required for combustion of the fuel-air mixture can be obtained based on the EGR rate and the combustion effect within the engine cylinder. The combustion effect within the engine cylinder is related to the EGR rate. Ignition energy refers to the minimum energy required to initiate a combustion reaction. It ensures that the fuel-oxidizer mixture begins combustion at the appropriate time and place. First, the type of fuel and its physical state must be determined. Different fuels have different ignition energy requirements; for example, liquid fuels and solid fuels have different ignition energy requirements. Furthermore, the physical state of the fuel, such as temperature and pressure, also affects the ignition energy.

[0087] In addition, the composition of the air-fuel mixture, the pressure and temperature of the air-fuel mixture, the spark plug gap, and the spark plug electrode shape are all related to the minimum ignition energy.

[0088] The minimum ignition energy initially decreases with decreasing air-fuel mixture density and then increases, exhibiting a saddle-shaped curve. When the air-fuel mixture density increases to the upper limit of flame propagation, the minimum ignition energy begins to decrease sharply. Since the total amount of air-fuel mixture per unit volume in the cylinder combustion chamber increases with increasing mixture pressure, improving ignition performance, the minimum ignition energy is approximately inversely proportional to the square of the mixture pressure. It is also easily understood that the minimum ignition energy is inversely proportional to temperature.

[0089] Because the electrodes have a cooling effect on the ignition source, part of the energy generated by the spark plug ignition is absorbed by the spark plug electrodes, and the other part is used for ignition. Under otherwise constant conditions, the smaller the spark plug gap, the more energy the electrodes absorb; therefore, the minimum ignition energy decreases as the spark plug gap increases. Furthermore, different shapes of the spark plug's center electrode produce different cooling effects. The sharper the electrode, the lower the minimum ignition energy.

[0090] In an engine, the EGR rate affects the ratio of fuel gas to oxygen in the fuel mixture. Ignition energy can be calculated using thermal equilibrium models, diffusion flame models, and detailed chemical kinetic models. The thermal equilibrium model assumes that the fuel and oxidizer mixture reaches thermal equilibrium at ignition, simplifying the calculation process. The diffusion flame model considers the flame propagation speed and fuel concentration distribution.

[0091] Analyzing the ignition process within the engine cylinders during operation, the ignition angle remains constant under stable operating conditions. Consequently, the temperature and pressure of the fuel-air mixture are approximately the same at the ignition moment. Furthermore, the spark plug gap, spark plug electrode shape, and fuel type and form do not change during engine operation. The specific values ​​of these factors can be pre-calibrated. Then, the EGR rate and the corresponding values ​​of the aforementioned factors can be input into the model for calculation, allowing the control module to obtain the corresponding minimum ignition energy based on the EGR rate.

[0092] The minimum charging time is then determined based on the minimum ignition energy. In one embodiment, the correspondence between ignition energy and charging time can be determined experimentally. The minimum charging time is then determined based on this correspondence and the obtained minimum ignition energy.

[0093] After obtaining the minimum charging time, the charging time of the ignition coil is reduced to the minimum charging time to protect the ignition module and prevent it from being damaged by overheating.

[0094] Referring to Figure 5, which illustrates the working principle and energy distribution of the ignition coil, it can be seen that the ignition energy released by the ignition coil during the discharge duration can be obtained by integrating the voltage and current output by the secondary coil during the discharge time. A corresponding mapping relationship can then be established. The ignition energy corresponding to the discharge duration can be determined using the above method combined with experimental data; or, based on the integration of the secondary discharge current and voltage over the discharge time, it can be verified whether the ignition coil releases the expected ignition energy.

[0095] In one embodiment of this application, the ignition module uses an IGBT transistor with fast turn-on speed and high switching frequency as a power switch to control whether the primary coil is grounded. The maximum allowable operating temperature of the IGBT transistor is 175°C. The first set temperature value can be set to 175°C. It is understood that the first set temperature is determined by the R&D personnel; it can also be determined to be any other temperature value lower than the maximum junction temperature of the power switch.

[0096] When the ignition module uses other types of power switches to control whether the primary coil is grounded, the first set temperature needs to be changed accordingly based on the type and model of the selected power switch.

[0097] This application also proposes a storage medium storing an ignition coil protection control program, which, when executed by a processor, implements the steps of the ignition coil protection control method.

[0098] The above embodiment discloses a scheme for adjusting the ignition coil charging time based on the ignition module temperature. Specifically, it adjusts the duration of the ignition signal output by the control module according to the ignition module temperature. However, this scheme requires that the control module not output abnormal signals; specifically, the control module cannot abnormally output an ignition signal with an excessively long duration, which would cause the ignition coil charging time to be too long and the ignition module to overheat.

[0099] Based on this, this application also proposes an engine ignition system, which includes: an ignition module, a control module, and an ignition coil;

[0100] The control module is connected to the ignition module; the first end of the ignition module is connected to the first end of the primary coil of the ignition coil, and the second end is grounded; the second end of the primary coil is connected to a DC voltage; the first end of the secondary coil of the ignition coil is connected to the spark plug.

[0101] The ignition module includes a temperature sensor, a power switch, and a control circuit.

[0102] The temperature sensor is connected to the control module and is used to detect the temperature of the ignition module and output it to the control module.

[0103] The first terminal of the power switch is connected to the first terminal of the primary coil, and the second terminal is grounded.

[0104] The first terminal of the control circuit is connected to the control module, and the second terminal is connected to the control terminal of the power switch; the control circuit is used to control the power switch to be turned on according to the ignition signal output by the control module.

[0105] The control circuit is also connected to the temperature sensor; the control circuit is also used to control the power switch to turn off when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the ignition module is higher than a first set temperature value.

[0106] The temperature sensor detects the temperature of the ignition module and outputs it to the control module and the control circuit. The control circuit needs to identify and respond promptly to abnormal signals output by the control module. First, according to the above embodiment, if the ignition module overheats, the control module first reduces the duration of the ignition signal; if the control module outputs an abnormal ignition signal for a longer duration, the temperature of the ignition module will remain above the first set temperature value.

[0107] When the control circuit detects that the duration of the ignition signal output by the control module exceeds a first preset duration, and the temperature of the ignition module is higher than a first set temperature value, it determines that the control module is outputting an abnormal signal and needs to intervene to promptly shut off the power switch to prevent damage to the ignition module. The first preset duration is determined by the R&D personnel. It should be noted that a longer first preset duration can improve the accuracy of detecting abnormal output from the control module; a shorter first preset duration can shorten the control circuit's reaction time to abnormal output from the control module.

[0108] The control circuit may further include a current detection circuit; the current detection circuit is connected to the control circuit; the current detection circuit is used to detect the current flowing through the power switch and output it to the control circuit. It is easy to understand that, to avoid excessively high voltage output from the secondary coil causing spark plug damage, it is necessary to control the current flowing through the primary coil; and the primary coil is connected in series with the power switch. When the current flowing through the power switch exceeds a preset current value, the control circuit controls the power switch to turn off.

[0109] Furthermore, based on the previous embodiment, the control circuit needs to detect the duration of the ignition signal and the temperature of the ignition module, and can only control the power switch to turn off under certain conditions; it can only handle situations where the ignition module overheats due to an abnormal ignition signal output by the control circuit. In another embodiment of this application, in order to prevent the ignition coil from carrying current for an extended period of time in the event of a short circuit in the engine ignition system, which could lead to overheating and damage to the ignition module, the control circuit can be used to control the power switch to turn off when the temperature of the ignition module is higher than a second set temperature value. The second set temperature value is higher than the first set temperature value, thereby avoiding interference in determining whether the ignition module overheats due to an abnormal signal output by the control module. The second set temperature value is determined by the researchers.

[0110] In summary, the steps for protecting the ignition module proposed in this application are as follows: if the temperature of the ignition module is higher than or equal to a first set temperature value, the duration of the ignition signal output by the control module is reduced. If reducing the duration of the ignition signal is ineffective (corresponding to abnormal control module output signals, short circuit in the engine ignition system, or prolonged grounding issues), the power switch is turned off. It should be noted that, as shown in Figure 2, if the corresponding control module outputs an abnormal signal, after the ignition signal returns to normal, the control circuit resets and resumes normal operation, rather than continuously turning off the power switch.

[0111] In Figure 2, after the temperature of the ignition module is detected to exceed the set temperature, the primary current in the primary coil is forcibly cut off. It is easy to understand that the voltage output on the secondary coil is positively correlated with the current in the primary coil. Suddenly forcibly disconnecting the power switch will cause high voltage to be generated on the ignition coil, affecting the life of the engine ignition system, spark plugs, and engine.

[0112] The specific model of the temperature sensor is not limited here. In one embodiment, a thermistor can be used to detect the temperature of the ignition module. The power switch can be an IGBT, a transistor, or a MOSFET, etc.

[0113] To avoid generating high voltage due to sudden forced disconnection, and to protect the engine ignition system, spark plugs, and engine, in one embodiment of this application, the control circuit is used to control the power switch to soft-shut down when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the ignition module is higher than a first set temperature value.

[0114] In this embodiment, a soft shutdown method is used to gradually reduce the current flowing through the primary coil and the power switch, thereby achieving the protection function. Figure 6 illustrates the corresponding relationship of the soft shutdown action. When an abnormal signal is detected from the control module output and the ignition module temperature exceeds the limit, the current in the primary coil is gradually reduced, thereby lowering the voltage generated by the secondary coil. As shown, after the ignition signal returns to normal, the control circuit resets and resumes normal operation.

[0115] In one embodiment, the power switch is an IGBT transistor;

[0116] The temperature sensor is used to detect the temperature of the IGBT tube and output it to the control module and the control circuit.

[0117] The control circuit is also used to control the IGBT to turn off in a soft-shutdown manner when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the IGBT is higher than a first set temperature value. The IGBT has the advantages of fast turn-off speed and high turn-off frequency, and is controlled by a voltage signal, which is beneficial for control.

[0118] In one embodiment of this application, the engine ignition system further includes:

[0119] An anomaly alert module is connected to both the control circuit and the vehicle's engine malfunction indicator light.

[0120] The control circuit is also used to output an abnormal signal to the abnormality reminder module when the duration of the ignition signal output by the control module exceeds a first preset duration;

[0121] The anomaly alert module records the number of anomaly signals received; the anomaly alert module is also used to illuminate the engine fault indicator light and clear the count value to zero when the count value exceeds a preset number.

[0122] The engine ignition system is used in the engine, which is generally used in vehicles. The vehicle's driver's cab has an instrument panel, which includes an engine malfunction indicator light. The anomaly warning module is connected to both the control circuit and the vehicle's engine malfunction indicator light. If the duration of the ignition signal output by the control module exceeds a first preset duration, it indicates that the control module may be damaged, or that the physical quantity used by the control module to determine the output ignition signal has been measured incorrectly, or that the control module has been subjected to external interference, resulting in the output of an incorrect ignition signal.

[0123] When the control circuit detects that the duration of the ignition signal exceeds a first preset duration, it outputs an abnormal signal to the abnormality alert module. It should be noted that if the abnormal signal occurs only once, it may be due to external interference with the control module; however, if the abnormal signal occurs multiple times, it may indicate a problem with the control module itself or the detection conditions. For example, poor grounding or other abnormal conditions may affect the parameters acquired by the control module, causing it to output an abnormal signal.

[0124] The anomaly alert module records the number of abnormal signals received. It also illuminates the engine malfunction indicator light and resets the count to zero when the count exceeds a preset number. After receiving more than the preset number of abnormal signals, the anomaly alert module illuminates the engine malfunction indicator light to alert the driver that the engine has malfunctioned and to promptly check the vehicle's grounding wire. Specifically, this malfunction will shorten the lifespan of the spark plugs, potentially causing the engine to fail to ignite and the vehicle to fail to start.

[0125] The preset number of times is determined by the R&D personnel.

[0126] The anomaly alert module records the number of abnormal signals received within a second preset time period. The module also illuminates the engine malfunction indicator light and resets the count to zero when the count exceeds a preset number. The second preset time period is determined by the R&D personnel. If the anomaly alert module records a sufficient number of abnormal signals received within the second preset time period, it indicates a significant potential hazard in engine operation. It is easy to understand that the larger the count within the second preset time period, the greater the potential hazard in engine operation.

[0127] In addition, the abnormality reminder module can also be connected to the vehicle controller. When the count value exceeds the preset number, it outputs a corresponding signal to the vehicle controller. After receiving the signal, the vehicle controller controls the in-vehicle speakers to play relevant prompts and / or controls the display screen to display relevant prompts.

[0128] In one embodiment of this application, the control circuit includes: a first resistor, a second resistor, a main control unit, and a first Zener diode;

[0129] The control module is connected to the first terminal of the first resistor, the cathode of the first Zener diode, and the first terminal of the second resistor;

[0130] The second end of the first resistor is connected to the anode of the first Zener diode, the emitter of the IGBT, and the second end of the main control unit;

[0131] The second end of the second resistor is connected to the first end of the main control unit and the gate of the IGBT transistor.

[0132] In this embodiment, the first resistor and the first Zener diode are used to protect the circuit; specifically, they are used to reduce the current flowing through the main control unit, preventing overcurrent damage to the main control unit; and they also accelerate the turn-on / turn-off speed of the IGBT. The second resistor is used to reduce the current flowing through the circuit, thereby reducing the voltage output of the secondary coil. The main control unit may include a controller such as a MUC, SOC, PLC, or FPGA.

[0133] In one embodiment of this application, the ignition coil further includes: a second Zener diode;

[0134] The anode of the second Zener diode is connected to the second end of the secondary coil, and the cathode is connected to the second end of the primary coil.

[0135] When the primary coil of the ignition coil is de-energized, the secondary coil generates a high voltage to ignite the spark plug. However, before the primary coil is de-energized, the secondary coil briefly induces a low forward voltage. If this forward voltage is directly transmitted to the spark plug, it may cause misignition or damage other components of the ignition system. A Zener diode prevents this forward voltage, allowing only reverse high voltage to flow to the spark plug, thus protecting the ignition system.

[0136] This application also proposes a vehicle that includes the engine ignition system or the storage medium described above.

[0137] The specific implementation of the engine ignition system and the ignition coil protection control method is shown above. The vehicle includes at least the beneficial effects brought by the above embodiments, which will not be elaborated here.

[0138] The above descriptions are merely some embodiments of this application and do not limit the scope of the patent. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of this application.

Claims

1. A method for protecting and controlling an ignition coil, wherein, The ignition coil protection and control method is applied to an engine ignition system; the engine ignition system includes: an ignition module, a control module, and an ignition coil; the control module is connected to the ignition module; a first terminal of the ignition module is connected to a first terminal of the primary coil of the ignition coil, and a second terminal is grounded; a DC voltage is applied to the second terminal of the primary coil; a first terminal of the secondary coil of the ignition coil is connected to a spark plug. The ignition coil protection control method includes: Detect the temperature of the ignition module; If the temperature of the ignition module is higher than or equal to the first set temperature value, the charging time of the ignition coil is reduced until the temperature of the ignition module is lower than the first set temperature value.

2. The ignition coil protection control method as described in claim 1, wherein, After the step of waiting until the temperature of the ignition module is lower than the first set temperature value, the method further includes: If the temperature of the ignition module is lower than the first set temperature value, the charging time of the ignition coil is determined according to the engine speed, the value of the DC voltage and the preset mapping relationship.

3. The ignition coil protection control method as described in claim 1, wherein, The step of reducing the charging time of the ignition coil specifically includes: Obtain the engine's EGR rate; The minimum ignition energy is determined based on the EGR rate. The minimum charging time is determined based on the minimum ignition energy, and the charging time of the ignition coil is reduced to the minimum charging time.

4. The ignition coil protection control method according to any one of claims 1 to 3, wherein, The first set temperature value is 175℃.

5. A storage medium, wherein, The storage medium stores an ignition coil protection control program, which, when executed by a processor, implements the steps of the ignition coil protection control method as described in any one of claims 1 to 4.

6. An engine ignition system, wherein, The engine ignition system includes: an ignition module, a control module, and an ignition coil; The control module is connected to the ignition module; the first end of the ignition module is connected to the first end of the primary coil of the ignition coil, and the second end is grounded; the second end of the primary coil is connected to a DC voltage; the first end of the secondary coil of the ignition coil is connected to the spark plug. The ignition module includes a temperature sensor, a power switch, and a control circuit. The temperature sensor is connected to the control module and is used to detect the temperature of the ignition module and output it to the control module. The first terminal of the power switch is connected to the first terminal of the primary coil, and the second terminal is grounded. The first terminal of the control circuit is connected to the control module, and the second terminal is connected to the control terminal of the power switch; the control circuit is used to control the power switch to be turned on according to the ignition signal output by the control module. The control circuit is also connected to the temperature sensor; the control circuit is also used to control the power switch to turn off when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the ignition module is higher than a first set temperature value.

7. The engine ignition system as claimed in claim 6, wherein, The control circuit is used to control the power switch to be turned off in a soft-shutdown manner when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the ignition module is higher than a first set temperature value.

8. The engine ignition system as claimed in claim 7, wherein, The power switch is an IGBT transistor; The temperature sensor is used to detect the temperature of the IGBT tube and output it to the control module and the control circuit. The control circuit is also used to control the IGBT to turn off in a soft-shutdown manner when the duration of the ignition signal output by the control module exceeds a first preset duration and the temperature of the IGBT is higher than a first set temperature value.

9. The engine ignition system as claimed in claim 8, wherein, The engine ignition system also includes: An anomaly alert module is connected to both the control circuit and the vehicle's engine malfunction indicator light. The control circuit is also used to output an abnormal signal to the abnormality reminder module when the duration of the ignition signal output by the control module exceeds a first preset duration; The anomaly alert module records the number of anomaly signals received; the anomaly alert module is also used to illuminate the engine fault indicator light and clear the count value to zero when the count value exceeds a preset number.

10. The engine ignition system as claimed in claim 8, wherein, The control circuit includes: a first resistor, a second resistor, a main control unit, and a first Zener diode; The control module is connected to the first terminal of the first resistor, the cathode of the first Zener diode, and the first terminal of the second resistor; The second end of the first resistor is connected to the anode of the first Zener diode, the emitter of the IGBT, and the second end of the main control unit; The second end of the second resistor is connected to the first end of the main control unit and the gate of the IGBT transistor.

11. The engine ignition system according to any one of claims 6 to 10, wherein, The ignition coil also includes: a second Zener diode; The anode of the second Zener diode is connected to the second end of the secondary coil, and the cathode is connected to the second end of the primary coil.

12. A vehicle, wherein, The vehicle includes an engine ignition system as described in any one of claims 6 to 10, or a storage medium as described in claim 5.

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