Electromagnetic protection device for a signal line of an automobile engine

Abstract

The application discloses an electromagnetic protection device for a car engine signal line, characterized in that the electromagnetic protection device comprises an engine signal protection circuit and a protection shell; wherein the engine signal protection circuit comprises a gas discharge tube, a transient voltage suppression diode and a filter circuit; the gas discharge tube is arranged at the front end of the engine signal protection circuit and is used for primary energy discharge; the transient voltage suppression diode is arranged at the middle section of the engine signal protection circuit and is used for fast response and voltage limiting protection; and the filter circuit is distributed at the middle section and the rear end of the engine signal protection circuit and is used for high-frequency interference suppression. The electromagnetic safety of the engine signal line can be comprehensively ensured, the reliability and stability of the vehicle control system are improved, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic protection technology, and more specifically, relates to an electromagnetic protection device for automotive engine signal lines. Background Technology

[0002] In the modern automotive industry, electronic control systems have become a core technological support for vehicle power performance, fuel economy, and emission control. The engine electronic control unit (ECU) collects signals from various sensors, such as accelerator pedal position, throttle opening, intake pressure, and temperature, to adjust fuel injection quantity, ignition timing, and intake air volume in real time, thereby achieving precise control of the engine's operating state. These sensor signals are mostly analog voltage signals, with amplitudes typically ranging from 0 to 5V, characterized by low frequency and small amplitude. However, with the continuous improvement of automotive electronics and intelligence, the number of onboard electronic devices has increased dramatically, the electromagnetic environment inside the vehicle has become increasingly complex, and the electromagnetic interference threat faced by engine signal circuits has significantly intensified.

[0003] During vehicle operation, high-voltage pulses generated by the ignition system, switching transients of motors and relays, radio frequency radiation from the vehicle communication system, and external lightning and electrostatic discharge can all interfere with sensitive sensor signal lines. This electromagnetic interference can lead to signal distortion, sampling errors, and in severe cases, even damage the input circuit of the control unit, causing problems such as abnormal engine operation, unstable power output, and excessive emissions, directly affecting vehicle driving safety and user experience.

[0004] In existing technologies, electromagnetic protection for automotive electronic systems mainly employs passive protection measures such as shielded cables, optimized grounding, and simple filter circuits. However, these methods have limited protection against high-energy electromagnetic pulses and insufficient response speed to rapid transient interference, making it difficult to meet the stringent electromagnetic compatibility requirements of modern automobiles. Especially in high-voltage electrical systems such as new energy vehicles and hybrid vehicles, the electromagnetic environment is even more severe, and traditional protection methods can no longer provide adequate protection.

[0005] Therefore, there is an urgent need to develop an integrated, miniaturized, and high-performance electromagnetic protection device that can rapidly discharge high-energy pulses, precisely clamp residual overvoltages, and effectively suppress high-frequency interference within a limited installation space, thereby comprehensively ensuring the electromagnetic safety of automotive engine signal circuits and improving the reliability and stability of the entire vehicle's electronic system. Summary of the Invention

[0006] The purpose of this application is to provide an electromagnetic protection device for automotive engine signal lines to improve the reliability and stability of the vehicle's electronic systems.

[0007] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides an electromagnetic protection device for automotive engine signal lines, comprising: an engine signal protection circuit and a protective housing; wherein, the engine signal protection circuit includes a gas discharge tube, a transient voltage suppression diode, and a filter circuit; the gas discharge tube is disposed at the front end of the engine signal protection circuit for primary energy discharge; the transient voltage suppression diode is arranged in the middle section of the engine signal protection circuit for fast response and voltage limiting protection; the filter circuit is distributed at the middle and rear ends of the engine signal protection circuit for suppressing high-frequency interference.

[0008] Optionally, the engine signal protection circuit is mounted on an integrated circuit board, which is fixedly installed inside the protective housing. The protective housing includes a metal housing, a metal cover plate, and a plug assembly. The metal cover plate is connected to the metal housing by metal screws. The plug assembly has a four-pin structure, divided into two sets of pins for signal input and output, respectively. The plug assembly is electrically connected to the integrated circuit board via wires.

[0009] Optionally, the engine signal protection circuit adopts a hierarchical protection structure, including a primary protection network and a secondary protection network; the primary protection network is composed of the gas discharge tube, which is located at the signal input terminal for rapid conduction and release of high-amplitude pulses; the secondary protection network is composed of multiple transient voltage suppression diodes connected in parallel, which are located after the gas discharge tube for clamping residual overvoltage; a matching resistor is provided between the gas discharge tube and the transient voltage suppression diodes for absorbing standing waves formed by reflected signals.

[0010] Optionally, the transient voltage suppression diodes in the secondary protection network are a four-wire parallel transient voltage suppression diode array, used to improve current sharing capability and total power capacity.

[0011] Optionally, the filtering circuit is an LC low-pass filter network, including a common-mode inductor and a bypass capacitor; the common-mode inductor is connected in series in the signal path to suppress common-mode noise; the bypass capacitor is connected in parallel between the signal path and the ground terminal to bypass high-frequency interference signals.

[0012] Optionally, the rated operating voltage of the engine signal protection circuit is 5V, the withstand voltage is 32V, and the rated operating current is less than 1mA; the cutoff frequency of the LC low-pass filter network is set to 15Hz.

[0013] Optionally, the engine signal protection component is located at the accelerator pedal sensor input signal port or the electronic throttle signal port to protect the vehicle's electronic control system from external electromagnetic pulse interference.

[0014] This application provides an electromagnetic protection device for automotive engine signal lines, comprising: an engine signal protection circuit and a protective housing; wherein, the engine signal protection circuit includes a gas discharge tube, a transient voltage suppression diode, and a filter circuit; the gas discharge tube is disposed at the front end of the engine signal protection circuit for primary energy discharge; the transient voltage suppression diode is arranged in the middle section of the engine signal protection circuit for fast response and voltage limiting protection; the filter circuit is distributed at the middle and rear ends of the engine signal protection circuit for suppressing high-frequency interference.

[0015] By employing a hierarchical protection structure consisting of a gas discharge tube, transient voltage suppression diodes, and a filter circuit, comprehensive protection against electromagnetic interference is achieved. The gas discharge tube, as the primary protection network, rapidly discharges high-energy electromagnetic pulses and lightning surges, protecting downstream circuits from high-energy impacts. The secondary protection network, composed of multiple parallel transient voltage suppression diodes, offers fast response and high clamping accuracy, effectively suppressing residual overvoltage and rapid transient interference. Secondly, the LC low-pass filter network, with its low cutoff frequency of 15Hz, efficiently filters out high-frequency noise while ensuring complete signal transmission, significantly improving signal quality and sampling accuracy. Thirdly, the modular packaging design is compact and easy to install, while the metal casing provides excellent electromagnetic shielding performance. Finally, the high withstand voltage of 32V provides ample safety margin, adapting to various transient conditions in automotive electrical systems. Overall, the protective device of this invention comprehensively ensures the electromagnetic safety of engine signal lines, improves the reliability and stability of vehicle control systems, and reduces maintenance costs. Attached Figure Description

[0016] 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a structural diagram of an electromagnetic protection device for an automotive engine signal line provided in an embodiment of this application; Figure 2 A circuit design diagram of an electromagnetic protection device for an automotive engine signal line provided in an embodiment of this application; Figure 3 This is an external structural diagram of an electromagnetic protection device for an automotive engine signal line provided in an embodiment of this application.

[0018] In the picture: 1-Electromagnetic protection device, 101-Gas discharge tube, 102-Transient voltage suppression diode, 103-Filter circuit, 201-Metal screw, 202-Plug assembly, 203-Metal cover plate, 204-Metal housing. Detailed Implementation

[0019] The purpose of this application is to provide an electromagnetic protection device for automotive engine signal lines to improve the reliability and stability of the vehicle's electronic systems.

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] The following embodiment illustrates an electromagnetic protection device for automotive engine signal lines provided in this application.

[0022] Please refer to Figure 1 , Figure 1 This is a structural diagram of an electromagnetic protection device for an automotive engine signal line provided in an embodiment of this application.

[0023] Please refer to Figure 2 , Figure 2 This is a circuit design diagram of an electromagnetic protection device for an automotive engine signal line provided in an embodiment of this application.

[0024] This embodiment provides an electromagnetic protection device 1 for automotive engine signal lines. The device includes an engine signal protection component, which consists of an engine signal protection circuit and a protective housing.

[0025] The engine signal protection circuit comprises three core components: a gas discharge tube 101, a transient voltage suppression diode 102, and a filter circuit 103. In the circuit topology, the gas discharge tube 101 is positioned at the front end of the circuit, near the signal input terminal, serving as the first line of defense for primary energy dissipation. When a high-energy electromagnetic pulse or transient surge occurs externally, the gas discharge tube 101 can quickly conduct, releasing most of the energy to ground, preventing high energy from directly impacting subsequent sensitive circuits.

[0026] Transient voltage suppressor diode 102 is positioned in the middle of the circuit, after the gas discharge tube 101 and before the filter circuit 103. Transient voltage suppressor diode 102 has an extremely fast response speed, typically in the sub-nanosecond range, enabling rapid response and voltage limiting protection against voltage spikes with fast rising edges. After the gas discharge tube 101 has discharged most of its energy, the residual overvoltage is precisely clamped by transient voltage suppressor diode 102, limiting the voltage within a safe range and ensuring that subsequent circuitry is not damaged.

[0027] The filter circuit 103 is distributed in the middle and rear sections of the circuit. The middle section filter circuit 103 works in conjunction with the transient voltage suppression diode 102, while the rear section filter circuit 103 is located near the signal output terminal. The main function of the filter circuit 103 is to suppress high-frequency interference. By designing a reasonable cutoff frequency, it effectively blocks the propagation path of high-frequency electromagnetic interference signals while ensuring the normal transmission of effective signals, thereby improving the signal stability and electromagnetic compatibility performance of the entire system.

[0028] Through the coordinated operation of the gas discharge tube 101, transient voltage suppression diode 102 and filter circuit 103, a multi-level, multi-frequency electromagnetic protection system is constructed, which can effectively cope with various interference threats faced by automotive engine signal lines in complex electromagnetic environments and ensure the stable and reliable operation of the engine electronic control system.

[0029] In another embodiment.

[0030] Please refer to Figure 3 , Figure 3 This is an external structural diagram of an electromagnetic protection device for an automotive engine signal line provided in an embodiment of this application.

[0031] like Figure 3 As shown, this embodiment further defines the physical structure and packaging form of the engine signal protection device.

[0032] The engine signal protection circuit is housed on an integrated circuit board, which features a miniaturized design and optimized dimensions to fit the installation requirements of standard automotive control boxes or wiring harnesses. The integrated circuit board is securely mounted inside a protective housing, employing a rational mounting method to ensure stable connection under vibration and shock conditions during vehicle operation.

[0033] The protective housing includes a metal housing 204, a metal cover 203, and a plug assembly 202. The metal housing 204 serves as the main cavity, providing physical protection and electromagnetic shielding space for the internal circuit board. The metal cover 203 covers the opening of the metal housing 204 and is securely connected to the metal housing 204 by four metal screws 201, forming a complete shielding cavity. The metal housing 204 and the metal cover 203 are typically made of metal materials with good conductivity and shielding properties, such as aluminum alloy or stainless steel, which can effectively block external electromagnetic fields from interfering with the internal circuitry and also prevent electromagnetic radiation generated by the internal circuitry from leaking outwards.

[0034] The plug assembly 202 has a four-pin structure, divided into two sets of pins. The first set of pins is used for signal input, connecting to external sensors or signal sources; the second set of pins is used for signal output, connecting to the vehicle control unit. The plug assembly 202 is electrically connected to the integrated circuit board via wires soldered to the input / output pads of the circuit board to ensure reliable electrical connections. The four-pin structure design is simple and straightforward, facilitating on-site installation and maintenance, while meeting the reliability and protection requirements of automotive electronic systems for connectors.

[0035] This modular packaging design makes the entire protective device compact and structurally stable, facilitating rapid deployment and replacement in vehicle electronic systems, and providing excellent engineering adaptability and ease of maintenance.

[0036] In another embodiment, the hierarchical protection structure design of the engine signal protection circuit is described in detail.

[0037] like Figure 2 As shown, the engine signal protection circuit adopts a hierarchical protection structure, including a primary protection network and a secondary protection network, to achieve the coordinated operation of high-energy transient surge discharge and low-voltage precision clamping.

[0038] The primary protection network consists of a gas discharge tube 101 (GDT). The gas discharge tube 101 is located at the signal input terminal, directly facing external electromagnetic interference and transient surges. The gas discharge tube 101 has a high response voltage threshold and a very high current carrying capacity. When a high-amplitude pulse exceeding its response voltage appears at the input terminal, the gas inside the gas discharge tube 101 breaks down and quickly conducts, forming a low-impedance path, rapidly releasing the high-energy pulse to ground, thereby protecting the subsequent circuitry from damage caused by high-energy impacts. This characteristic of the gas discharge tube 101 makes it the preferred device for dealing with high-energy interference such as lightning surges and electromagnetic pulses.

[0039] The secondary protection network consists of multiple transient voltage suppressor diodes 102 connected in parallel. This secondary protection network is positioned after the gas discharge tube 101, downstream of the primary protection network in the circuit topology. Even after the gas discharge tube 101 has discharged most of its energy, residual overvoltage or rapidly rising voltage spikes may still exist; in this case, the secondary protection network comes into play. The transient voltage suppressor diodes 102 have extremely fast response times, typically in the picosecond to nanosecond range, enabling precise clamping of these rapid transients and limiting the voltage within a preset safe threshold. The parallel design of multiple TVS diodes significantly improves the overall current sharing capability, avoids overloading of individual devices, and simultaneously enhances the system's total power capacity and reliability.

[0040] A matching resistor is provided between the gas discharge tube 101 and the transient voltage suppression diode 102. The function of this matching resistor is to absorb reflected signals caused by impedance mismatch during signal transmission, reducing the formation of standing waves (VSWRs). VSWRs can cause local extreme values ​​of voltage and current at the signal port, potentially causing additional stress on the device. By appropriately selecting the value of the matching resistor, the VSWR of the signal port can be optimized, the impedance matching characteristics of the circuit can be improved, and the overall electromagnetic compatibility performance can be further enhanced.

[0041] By utilizing the high-energy discharge of the primary protection network and the rapid and precise clamping of the secondary protection network, along with impedance optimization of the matching resistor, this embodiment constructs a comprehensive hierarchical protection system capable of responding to various electromagnetic threats ranging from high-energy surges to rapid transients.

[0042] In another embodiment, the specific configuration of the transient voltage suppression diode 102 in the secondary protection network is further defined.

[0043] The transient voltage suppression diodes 102 in the secondary protection network are configured as a four-wire parallel TVS array. Specifically, four independent TVS diodes are connected in parallel on the signal line, with the anode of each TVS diode connected to the signal line and the cathodes grounded together.

[0044] This four-wire parallel configuration offers several technical advantages. First, the parallel structure reduces the current flowing through each TVS diode to only about a quarter of the total current, significantly lowering the current stress on individual devices and effectively preventing device damage or performance degradation due to overcurrent. Second, the total current carrying capacity and power capacity are increased to four times that of a single device, enabling the entire protection module to cope with higher-energy transient impact events and significantly improving the system's protection margin. Third, the parallel operation of multiple devices also provides a certain degree of redundancy protection; even if one TVS device fails, the remaining devices can still continue to provide protection, enhancing the system's fault tolerance and long-term reliability.

[0045] In practical applications, the four-wire parallel TVS array configuration can ensure that the protection module operates reliably under various transient impact conditions, meet the stringent reliability and safety requirements of automotive electronic systems, effectively extend the service life of devices, and reduce system maintenance costs.

[0046] In another embodiment, the specific structure and working principle of the filter circuit 103 are described in detail.

[0047] like Figure 2 As shown, the filter circuit 103 adopts an LC low-pass filter network structure, including two core components: a common-mode inductor and a bypass capacitor.

[0048] The common-mode inductor is connected in series in the signal path. The signal line enters the common-mode inductor after passing through the gas discharge tube 101 and the transient voltage suppression diode 102 from the input terminal, and then outputs to the load terminal. The common-mode inductor typically employs a dual-winding structure, with two signal lines (such as the positive and negative lines of a differential signal or the signal line and reference line) wound on the same magnetic core in the same direction. For common-mode interference signals, i.e., interference currents flowing in the same direction on both lines, the common-mode inductor exhibits high impedance, effectively suppressing the propagation of common-mode noise. For differential-mode signals, i.e., normal useful signals, since the current directions are opposite, the magnetic flux cancels each other out, and the common-mode inductor exhibits low impedance, not affecting the transmission of the useful signal. This characteristic makes the common-mode inductor particularly suitable for suppressing common-mode noise caused by cable coupling or ground potential difference.

[0049] The bypass capacitor is connected in parallel between the signal path and the ground terminal. In the circuit topology, the bypass capacitor is usually placed after the common-mode inductor, close to the signal output terminal. The bypass capacitor exhibits low impedance characteristics for high-frequency signals, which can shun high-frequency interference signals to the ground terminal, thus achieving energy bypass. At the same time, the capacitor and the common-mode inductor together form an LC low-pass filter, which has a well-defined cutoff frequency characteristic, achieving frequency-selective attenuation of signals above the cutoff frequency.

[0050] The common-mode inductor and bypass capacitor work together to form a complete LC low-pass filter network. This network not only effectively suppresses radio frequency interference and electrical fast transient pulses, but also significantly enhances the integrity and stability of the signal link, ensuring that the signal transmitted to the control unit is clean and accurate, meeting the requirements of high-precision analog signal sampling.

[0051] In another embodiment, the key electrical parameters of the engine signal protection circuit are further clarified.

[0052] The rated operating voltage of the engine signal protection circuit is set to 5V. This is because analog sensors such as the accelerator pedal sensor in modern automotive electronic systems generally use a 5V power supply standard. The rated operating voltage defines the voltage level during normal circuit operation and is also the benchmark for designing the parameters of each level of protection device.

[0053] A withstand voltage rating of 32V indicates that the protection circuit can withstand a continuous voltage of up to 32V without damage or performance degradation. This withstand voltage setting fully considers voltage fluctuations, startup surges, and other transient overvoltage events that may occur in automotive electrical systems, providing sufficient safety margin.

[0054] The rated operating current is less than 1mA. This is because the accelerator pedal sensor is an analog voltage output sensor, and signal transmission mainly relies on voltage rather than current, resulting in a very small actual operating current. The protection circuit is designed in a low-power, low-current mode to ensure that it does not affect the signal transmission load, while also reducing the overall energy consumption of the system.

[0055] The cutoff frequency of the LC low-pass filter network is set to 15Hz. This cutoff frequency is chosen based on an in-depth analysis of the accelerator pedal sensor signal characteristics. The accelerator pedal signal is a low-frequency analog signal, with an effective frequency range typically between several hertz and tens of hertz, exhibiting stable frequency and slow frequency change. Setting the filter cutoff frequency to 15Hz ensures the complete passage of the effective signal while effectively attenuating high-frequency interference signals above 15Hz. This low cutoff frequency design is particularly suitable for applications requiring high ADC sampling accuracy, significantly reducing the impact of high-frequency noise on the sampling results and improving signal quality and control precision.

[0056] By setting the above electrical parameters reasonably, the protection circuit of this embodiment can provide reliable electromagnetic protection function and ensure the accuracy and stability of signal transmission, fully meeting the actual needs of automotive engine signal protection.

[0057] In another embodiment, the specific application scenario and installation location of the engine signal protection device are illustrated.

[0058] The engine signal protection component can be installed at the accelerator pedal sensor input signal port. The accelerator pedal sensor is one of the key sensors in the automotive electronic control system, responsible for converting the driver's pedal input intention into an electrical signal and transmitting it to the engine control unit. This signal line is exposed to the complex electromagnetic environment inside the vehicle, making it susceptible to electromagnetic interference from the ignition system, motors, relays, and other devices, and also vulnerable to high-energy electromagnetic pulses such as lightning strikes and electrostatic discharges. Installing the protection component at the accelerator pedal sensor input signal port—that is, connecting the protection device in series on the signal line between the sensor output and the control unit input—can effectively block various types of electromagnetic interference, protect the control unit's input circuit from damage, and ensure accurate transmission of the accelerator signal.

[0059] The engine signal protection component can also be installed at the electronic throttle signal port. The electronic throttle is the actuator of the engine intake system, receiving commands from the control unit and adjusting the intake air volume. The position feedback signal of the electronic throttle also requires high precision and high reliability, and this signal line faces similar electromagnetic interference threats. Installing the protection device of this invention at the electronic throttle signal port can protect the position sensor signal and control signal from electromagnetic interference, ensuring the accuracy and response speed of throttle control.

[0060] In addition to the two typical application scenarios mentioned above, the protective device of this invention can also be applied to the protection of other analog signal ports related to various automotive engines, such as the signal interfaces of intake pressure sensors, intake air temperature sensors, coolant temperature sensors, and knock sensors. These sensor signals are crucial for the precise control of the engine. By deploying protective devices at their signal ports, the ability of the automotive electronic control system to be protected from external electromagnetic pulse interference can be comprehensively improved, ensuring the stable and reliable operation of the engine in various electromagnetic environments and improving the safety and reliability of the entire vehicle.

[0061] In actual installation, the protective components can be directly integrated inside the sensor plug, in the middle of the wiring harness sheath, or near the input terminal of the control unit. The optimal installation solution can be selected based on the specific vehicle model and wiring method. The modular packaging design makes installation, replacement, and maintenance very convenient, adapting to the development trend of rapid iteration and modular design in modern automotive electronic systems.

[0062] Furthermore, through another specific embodiment, an electromagnetic protection device for automotive engine signal lines provided in this application will be further described.

[0063] This embodiment describes a protection circuit for the accelerator pedal sensor input signal port. It employs an integrated circuit board design, resulting in a compact module that can be directly installed in the control unit or wiring harness. The module structure comprises a three-level protection network, including a gas discharge tube 101, a TVS array, and a low-pass filter, effectively creating a multi-level protection barrier against electromagnetic interference. This protection circuit aims to improve the system's resistance to voltage transients and electromagnetic interference, thereby ensuring the stable operation of the automotive electronic control system.

[0064] The key parameters of the protection circuit are as follows: rated operating voltage of 5V, withstand voltage of 32V, rated operating current of less than 1mA, and filter cutoff frequency set to 15Hz. Considering that the accelerator pedal sensor outputs an analog signal with a low and stable frequency, this device adopts a low cutoff frequency filtering design to effectively suppress high-frequency pulse interference without compromising effective signal transmission, making it particularly suitable for scenarios requiring high ADC sampling accuracy.

[0065] In the protection circuit proposed in this embodiment, the design of the discharge network fully considers the potential threats to system stability from electromagnetic interference and transient surge currents. This device adopts a hierarchical protection strategy to achieve the coordinated operation of high-energy transient surge discharge and low-voltage precision clamping: Specifically, the first-level protection uses a gas discharge tube 101 as a high-energy discharge element, which has a high response voltage and high current carrying capacity, and can quickly conduct and release high-amplitude pulses to prevent damage to downstream components. The second-level protection uses a four-wire parallel TVS array, which has a sub-nanosecond response speed and low breakdown voltage, and continues to suppress residual overvoltage even when the GDT is not conducting or after the GDT has discharged. The parallel structure design significantly improves the module current sharing capability and total power capacity, ensuring reliable operation under various transient impact conditions. At the same time, a matching resistor is added between the GDT and the TVS to effectively absorb the standing wave formed by the reflected signal, optimize the VSWR of the signal port, and improve electromagnetic compatibility.

[0066] To further enhance the system's electromagnetic compatibility and anti-interference capabilities, this embodiment integrates an LC low-pass filter network composed of a common-mode inductor and a bypass capacitor in the signal path. The structure consists of a common-mode inductor and a parallel bypass capacitor, effectively blocking the transmission path of high-frequency interference signals by forming a low-pass filter response in the signal path. The common-mode inductor effectively suppresses common-mode noise caused by cable coupling or ground potential difference, while the bypass capacitor achieves energy bypassing and frequency-selective attenuation for high-frequency interference. Their synergistic effect not only improves the system's ability to suppress radio frequency interference and electrical fast transient pulses but also significantly enhances the integrity and stability of the signal link. In summary, the accelerator pedal sensor input signal port protection circuit of this embodiment has a reasonable structure, combining surge protection and electromagnetic interference suppression functions. It is suitable for electrical protection scenarios of analog signal links and possesses good electrical stability and system compatibility.

[0067] This embodiment adopts a highly integrated modular packaging form, facilitating rapid deployment and replacement in automotive electronic systems. The external structure of the cavity consists of four main components: a metal shell 204, a metal cover plate 203, metal screws 201, and a plug 202 for external connections. The core of the protective module is a small-sized PCB, which is fixedly installed inside the metal shielded cavity and securely connected by four metal screws. The module shell consists of a metal shell, a metal cover plate, and a plug assembly, providing excellent electromagnetic shielding performance and mechanical stability. The plug has a four-pin structure, divided into two sets of pins for signal input and output, respectively. After soldering, it is connected to the internal circuitry of the PCB via wires, achieving a stable and reliable external connection. The module package size is optimized to fit standard automotive control boxes or wiring harnesses, facilitating automotive-grade wiring and subsequent maintenance, demonstrating advantages in miniaturization and engineering adaptability.

[0068] Compared with existing technologies, this embodiment has significant advantages in electromagnetic pulse protection, mainly reflected in the following aspects: Multi-level protection + energy shunting design: TVS has a fast response and GDT has strong current carrying capacity; the two work together to enhance the electromagnetic pulse carrying capacity. High power capacity TVS array: The four-wire parallel structure design improves shunting efficiency, reduces stress on individual devices, effectively extends the service life of TVS devices, and enhances the overall reliability and stability of the system. Modular packaging: Facilitates system integration, field replacement, and maintenance; suitable for various throttle sensors, electronic throttle valves, and vehicle analog signal ports. Small size and high integration design: Greatly saves installation space and supports the miniaturization trend of vehicle electronic control systems. Simultaneous enhancement of filtering and anti-interference: Significantly improves EMC performance, meeting the reliability requirements of modern intelligent vehicles operating in strong interference environments.

[0069] In summary, this embodiment integrates a miniaturized, high-power-capacity multi-level protection structure to construct an electromagnetic protection module that is stable in performance, compact in structure, and flexible in application, providing a high-performance anti-interference solution with industrialization potential for automotive electronic systems.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0071] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0072] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0073] The electromagnetic protection device for automotive engine signal lines provided in this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. An electromagnetic protection device for automotive engine signal lines, characterized in that, include: An engine signal protection circuit and a protective housing; wherein the engine signal protection circuit includes a gas discharge tube, a transient voltage suppression diode, and a filter circuit; The gas discharge tube is located at the front end of the engine signal protection circuit for primary energy discharge; the transient voltage suppression diode is located in the middle section of the engine signal protection circuit for fast response and voltage limiting protection; the filter circuit is distributed in the middle and rear sections of the engine signal protection circuit for suppressing high-frequency interference.

2. The electromagnetic protection device according to claim 1, characterized in that, The engine signal protection circuit is mounted on an integrated circuit board, which is fixedly installed inside the protective housing. The protective housing includes a metal housing, a metal cover plate, and a plug assembly. The metal cover plate is connected to the metal housing by metal screws. The plug assembly has a four-pin structure, divided into two sets of pins for signal input and output, respectively. The plug assembly is electrically connected to the integrated circuit board via wires.

3. The electromagnetic protection device according to claim 2, characterized in that, The engine signal protection circuit adopts a hierarchical protection structure, including a primary protection network and a secondary protection network. The primary protection network is composed of the gas discharge tube, which is located at the signal input terminal for rapid conduction and release of high-amplitude pulses. The secondary protection network is composed of multiple transient voltage suppression diodes connected in parallel, which are located after the gas discharge tube for clamping residual overvoltage. A matching resistor is provided between the gas discharge tube and the transient voltage suppression diodes to absorb the standing waves formed by the reflected signal.

4. The electromagnetic protection device according to claim 3, characterized in that, The transient voltage suppression diodes in the secondary protection network are a four-wire parallel transient voltage suppression diode array, used to improve current sharing capability and total power capacity.

5. The electromagnetic protection device according to claim 4, characterized in that, The filter circuit 103 is an LC low-pass filter network, including a common-mode inductor and a bypass capacitor; the common-mode inductor is connected in series in the signal path to suppress common-mode noise; the bypass capacitor is connected in parallel between the signal path and the ground terminal to bypass high-frequency interference signals.

6. The electromagnetic protection device according to claim 5, characterized in that, The rated operating voltage of the engine signal protection circuit is 5V, the withstand voltage is 32V, and the rated operating current is less than 1mA; the cutoff frequency of the LC low-pass filter network is set to 15Hz.

7. The electromagnetic protection device according to claim 6, characterized in that, The engine signal protection component is located at the accelerator pedal sensor input signal port or the electronic throttle signal port to protect the vehicle's electronic control system from external electromagnetic pulse interference.

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