Piezoelectric crystal fuel injector damage detection device and method

Abstract

The invention discloses a piezo-electric crystal fuel injector damage detection device and method, and relates to the technical field of equipment fault detection, the device comprises a detection wire harness, a parameter acquisition module, an operation input module, an MCU, a power supply module and a display module; the detection harness is used for connecting the oil injector interface and the parameter acquisition module; the parameter acquisition module is used for acquiring voltage and oscillation frequency of the oil injector; the operation input module is used for providing model information of different oil injectors; the MCU is used for calling a corresponding fuel injector capacitance expected value according to the currently input fuel injector model information, and performing fault detection on the connected fuel injector in combination with the voltage and oscillation frequency provided by the parameter acquisition module to determine the damage state of the fuel injector; the power supply module is used for providing required voltage for each module in the device; the display module is used for displaying the damage state and parameter information of the oil sprayer. The device improves the capacitance test precision of the oil injector, can automatically identify different damage states of the piezoelectric oil injector, and reports corresponding faults.

Description

Technical Field

[0001] This invention relates to the field of equipment fault detection technology, and in particular to a piezoelectric crystal fuel injector damage detection device and method. Background Technology

[0002] Piezoelectric crystal injectors are the core component of the most advanced and precise electronic fuel injection system in modern diesel engines, especially high-performance diesel engines that meet stringent emission standards (such as Euro VI and China VI). Piezoelectric crystal injectors utilize the piezoelectric effect to achieve high-precision control of fuel injection. Compared to traditional injectors, piezoelectric crystal injectors offer faster response times, higher injection accuracy, stronger multiple injection capability, and better control consistency. They have played a revolutionary role in improving engine power, economy, and reducing emissions. Currently, the industry offers various types of piezoelectric crystal injectors based on differences in compatible engine models, structural design, and operating parameters, meeting the adaptation needs of electronic fuel injection systems with different power levels and operating conditions, and their application coverage continues to expand.

[0003] However, in actual operation and maintenance, the damage detection and troubleshooting of piezoelectric crystal fuel injectors face numerous technical challenges. For example, the working environment of piezoelectric crystal fuel injectors is typically characterized by complex conditions such as high temperature, high pressure, strong vibration, and fuel impurity corrosion. Furthermore, due to their diverse types, the causes of damage are multifaceted, including structural failures such as aging and fatigue damage of the piezoelectric crystal elements, as well as external factors such as poor circuit contact and fuel passage blockage. Moreover, the fault states of fuel injectors after failure are varied, making it difficult to identify the failure mode. Existing technologies for fuel injector detection are mostly adapted to traditional electromagnetic fuel injectors, lacking specific detection methods tailored to the characteristics, damage causes, and failure patterns of piezoelectric crystal fuel injectors, thus failing to meet the needs for efficient and accurate damage detection.

[0004] Therefore, there is an urgent need for a method and device for detecting damage to piezoelectric crystal fuel injectors in order to solve the aforementioned industry pain points. Summary of the Invention

[0005] In response to the above-mentioned problems and technical requirements, the inventors have proposed a piezoelectric crystal injector damage detection device and method, which solves the problem of difficulty in determining the damage mode / state of piezoelectric crystal injectors.

[0006] The technical solution of the present invention is as follows: In a first aspect, this application provides a piezoelectric crystal injector damage detection device, comprising: The detection harness is used to connect the piezoelectric crystal injector interface and the parameter acquisition module; The parameter acquisition module is used to acquire the voltage and oscillation frequency of the fuel injector; The operation input module is used to provide information on different injector models; The MCU is used to retrieve the expected value of the corresponding injector capacitor based on the currently input injector model information, and, in conjunction with the voltage and oscillation frequency provided by the parameter acquisition module, to perform fault detection on the connected injector and determine the damage status of the injector. The power module is used to provide the required voltage to the various modules inside the device. The display module is used to show the damage status and parameter information of the fuel injector.

[0007] A further technical solution is that the parameter acquisition module includes components connected to the MCU: The voltage acquisition unit is used to inject voltage into the connected injector and collect the voltage signal, and transmit the collected injector voltage to the MCU for damage status judgment. The oscillation frequency acquisition unit is used to generate an oscillation waveform that meets the requirements of the injector drive, and transmits the acquired injector oscillation frequency to the MCU for capacitor abnormality detection.

[0008] A further technical solution is that the voltage acquisition unit includes a first control switch circuit, a voltage injection circuit, and a voltage feedback circuit, wherein: The input terminal of the first control switch circuit is connected to the power supply voltage provided by the power module, the control terminal is connected to the MCU, and the output terminal is connected to the power supply terminal of the voltage feedback circuit. The input terminal of the voltage injection circuit is connected to the reference voltage provided by the power module, and the output terminal is connected in series with a resistor to the detection harness, which is used to charge the injector through the resistor. The input terminal of the voltage feedback circuit is connected to the detection harness, and the output terminal is connected to the MCU. It is used to feedback the signal after the injector voltage is injected when the MCU controls the first control switch circuit to be turned on, and transmit the feedback voltage to the MCU.

[0009] A further technical solution is that the oscillation frequency acquisition unit includes a second control switch circuit, a matching resistor selection switch matrix, and an oscillator circuit, wherein: The input terminal of the second control switch circuit is connected to the power supply voltage provided by the power module, the control terminal is connected to the MCU, and the output terminal is connected to the power supply terminal of the matching resistor selection switch matrix and oscillator circuit. The input of the matching resistor selection switch matrix is ​​connected to the MCU, and the output is connected to the resistor selection terminal of the oscillator circuit. It is used to select a suitable matching resistor in conjunction with the MCU when the second control switch circuit is turned on by the MCU, and configure it for the oscillator circuit. The input of the oscillator circuit is connected to the detection harness, and the output is connected to the MCU through the RC frequency detection circuit. When the MCU controls the second control switch circuit to be turned on, it will generate an oscillation waveform in conjunction with the internal capacitor of the fuel injector and transmit the oscillation frequency collected by the RC frequency detection circuit to the MCU.

[0010] A further technical solution involves performing fault detection on the connected injectors to determine the damage condition of the injectors, including: The MCU enables the voltage acquisition unit. When the collected voltage is 0V, it determines that the damage is an internal short circuit in the injector and transmits the information to the display module for display. When the feedback voltage is not 0V, the damage status is determined by combining the expected value of the injector capacitor, either by an internal open circuit in the injector or by entering the injector capacitor abnormality detection, and then transmitted to the display module for display. When detecting abnormalities in the injector capacitor, the MCU shuts down the voltage acquisition unit, enables the oscillation frequency acquisition unit, and calculates the current capacitance value of the injector based on the oscillation frequency. The MCU compares the current capacitance value of the injector with the expected capacitance value of the injector to determine whether there is any abnormality in the injector capacitance parameter, and then transmits the result to the display module for display.

[0011] The further technical solution is that when the sampling voltage is not 0V, the damage state is determined by combining the expected value of the injector capacitor to be either an internal open circuit in the injector or an abnormality detection of the injector capacitor, including: When the sampling voltage is not 0V, and the sampling voltage collected within the set sampling period is equal to the injection voltage provided by the voltage acquisition unit, the damage condition is determined to be an internal open circuit in the injector. When the sampling voltage is not 0V, and the sampling voltage collected within the set sampling period is less than the injection voltage provided by the voltage acquisition unit, the MCU enters the injector capacitor abnormality detection. The length of the sampling period is set to be less than the product of the expected value of the injector capacitor and the resistance value of the resistor connected to the voltage injection circuit in the voltage acquisition unit.

[0012] A further technical solution involves the MCU comparing the current capacitance value of the injector with the expected capacitance value to determine if there are any abnormalities in the injector capacitance parameters. The MCU's judgment logic includes: If the current capacitance value of the injector is less than the expected value of the injector capacitor, the injector capacitor is determined to be abnormal. If the current capacitance value of the injector is equal to the expected value of the injector capacitor, then the injector capacitor is considered to be normal. If the current capacitance value of the injector is greater than the expected value of the injector capacitance, the device is considered to be faulty.

[0013] A further technical solution is that the operation input module includes: The control panel provides an operation and control interface, with buttons arranged to represent different injector models; A button sensor is used to sense button signals on the control panel and convert the button signals into electrical signals. The sensor detection circuit is used to filter the electrical signal output by the button sensor and transmit it to the MCU.

[0014] Its further technical solution is that the power module includes: Power port protection circuit, used to protect against and filter abnormalities in the raw voltage supplied by external power supply; The voltage regulator circuit is used to step down the filtered voltage output by the power port protection circuit or the voltage provided by the internal battery to provide the required voltage for each module. Internal battery connected to voltage regulator circuit; When there is an external power input, the internal battery is charged through the voltage regulator circuit, and when there is no external power input, the internal battery powers the voltage regulator circuit.

[0015] Secondly, this application also provides a method for detecting damage to a piezoelectric crystal injector. This method is integrated within the MCU of the piezoelectric crystal injector damage detection device as described in the first aspect, and includes the following steps: Real-time acquisition of the voltage and oscillation frequency of the piezoelectric crystal fuel injector connected to the device; Based on the currently input injector model information, retrieve the corresponding injector capacitor expectation value, and combine it with voltage and oscillation frequency to perform fault detection on the connected injectors and determine the injector's damage status.

[0016] The beneficial technical effects of this invention are: This device addresses the diverse types and parameters of fuel injectors by incorporating an executable solution within the MCU, including injector model identification, capacitor parameter matching, and specific injector fault detection. Fault detection relies on a parameter acquisition module that collects injector voltage and oscillation frequency. The MCU first determines the damage state based on the injector voltage and expected capacitor value. To address the issue of small fluctuations in injector capacitor parameters, a capacitor anomaly detection method is designed. When a potential injector capacitor anomaly is detected, further damage state determination is performed based on the oscillation frequency and expected capacitor value. This device can automatically identify different damage states of piezoelectric injectors and report corresponding faults. It can also identify the causes of piezoelectric crystal injector damage based on the damage state, providing valuable assistance for troubleshooting and resolving problems during actual maintenance. Attached Figure Description

[0017] Figure 1This is a simplified schematic diagram of the structure of the piezoelectric crystal fuel injector damage detection device provided in this application; Figure 2 This is a complete schematic diagram of the structure of the piezoelectric crystal fuel injector damage detection device provided in this application; Figure 3 This is a schematic diagram of the control switch circuit provided in this application; Figure 4 This is a circuit diagram of the oscillation frequency acquisition unit provided in this application; Figure 5 This is a flowchart of the piezoelectric crystal injector damage detection method provided in this application. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0019] Through research and analysis of piezoelectric crystal injectors, the inventors have concluded that the causes of damage to piezoelectric crystal injectors include electrical breakdown, mechanical breakage, and aging. Common states / modes of piezoelectric crystal injector damage include changes in electrical parameters (mainly capacitance changes), injector short circuits, and injector open circuits. Therefore, one embodiment of this application provides a piezoelectric crystal injector damage detection device, such as... Figure 1 As shown, the device includes: a detection harness, an MCU, and a parameter acquisition module, an operation input module, a power supply module, and a display module connected to the MCU. Each part performs the following functions: 1) The detection harness is used to connect the piezoelectric crystal injector interface and the parameter acquisition module when the device is in use. In this embodiment, the detection harness is designed as a one-to-many harness. One end of the harness is connected to a pair of positive and negative differential interfaces on the device end, and the other end branches into multiple harness interfaces, which are connected to different injector interfaces, thereby adapting to different piezoelectric crystal injector products on the market.

[0020] 2) The parameter acquisition module is a circuit unit assembly used to acquire the voltage and oscillation frequency of the connected injectors. In this embodiment, the module includes a voltage acquisition unit and an oscillation frequency acquisition unit connected to the MCU. The voltage acquisition unit injects voltage into the connected injectors and acquires the voltage signal, transmitting the acquired injector voltage to the MCU for damage status assessment. The oscillation frequency acquisition unit generates an oscillation waveform that meets the injector driving requirements and transmits the acquired injector oscillation frequency to the MCU for capacitance anomaly detection.

[0021] 3) The operation input module provides different injector model information to match different capacitance parameters, thereby accurately testing the damage status. All injector model information is typically stored in the injector database. 4) The MCU is the core computing and processing unit of the device. Its functions include identifying injector model information, retrieving injector capacitance parameters, controlling and processing the voltage and oscillation frequency acquisition units, and communicating with the external display module. In this embodiment, the MCU retrieves the corresponding expected injector capacitance value based on the currently input injector model information. Combined with the voltage and oscillation frequency provided by the parameter acquisition module, it performs fault detection on the connected injectors to determine their damage status. Optionally, it can also determine the cause of the damage. The MCU outputs the identified injector damage status and cause, along with injector parameter information (such as current capacitance value and model), to the display module for display via the communication module. In this embodiment, the display module uses an LCD screen, and the communication interface is a CAN communication interface.

[0022] 5) The power module provides the necessary operating voltage for the internal MCU, parameter acquisition module, operation input module, and display module. In this embodiment, the power module is designed to support both external power supply and internal power supply, increasing the ease of use of the device.

[0023] The following is combined Figure 2 The diagram showing the complete structure of the device further illustrates the internal composition and working principle of each module: The power module includes a power port protection circuit, a voltage regulator circuit, and an internal battery. The power port protection circuit is used to protect against and filter abnormalities in the raw voltage supplied by the external power source. In one possible implementation, the power port protection circuit includes: a surge protection circuit for protecting against external surge interference, implemented using a TVS design; a reverse connection protection circuit, implemented using a diode design; and a CLC π-type filter circuit for filtering out power line interference. The connection method between them can be implemented with reference to existing circuit structures, and will not be described in detail here.

[0024] The voltage regulator circuit is used to step down the filtered voltage output from the power port protection circuit or the voltage provided by the internal battery to provide the operating voltage required by the aforementioned modules. In one possible implementation, the voltage regulator circuit is designed using a DC-DC converter + LDO structure: the DC-DC converter first pre-steps down the external input voltage, then the LDO performs a second-stage step-down, with the LDO output voltage used to power the internal circuitry. Optionally, a high-voltage-resistance DC-DC converter is selected, using the TI LMR76002. This power supply solution supports 48V external battery power, 24V battery power, and 12V battery power, meeting the application requirements of current mainstream piezoelectric injector products and covering various application scenarios.

[0025] The added internal battery contains a charging and discharging circuit, which can perform two functions: first, it charges the internal battery through the voltage regulator circuit when there is an external power input; second, it uses the internal battery to power the voltage regulator circuit when there is no external power input, ensuring that the device can work continuously.

[0026] The communication module includes a communication signal processing circuit and a communication interface filtering and protection circuit. The two ends of the communication signal processing circuit are connected to the MCU and the communication interface filtering and protection circuit, respectively. In this embodiment, a CAN circuit is used for the communication signal processing circuit design, and the selected solution is the Texas Instruments (TI) TCAN1042, which has strong anti-interference capabilities and more reliable communication. The communication interface filtering and protection circuit mainly handles and protects against surges, ESD, and communication interference. In this embodiment, a common-mode filter circuit is designed using a TDK common-mode inductor ACT45B-510-2P-TL003 to protect against common-mode interference; electrostatic surge protection is achieved by designing a port protection TVS and a filter capacitor.

[0027] The operation input module includes an operation panel, button sensors, and sensor detection circuitry. The operation panel provides the operation control interface, displaying buttons representing different injector models. The button sensors detect button signals on the operation panel and convert them into electrical signals. The sensor detection circuitry filters the electrical signals output by the button sensors and transmits them to the MCU for injector fault detection. Optionally, when the MCU detects multiple simultaneous button signals, it determines it as an external input anomaly and transmits the information to the display module via communication circuitry, displaying an error message on the operation panel to alert the operator of any misoperation.

[0028] The voltage acquisition unit includes a first control switch circuit, a voltage injection circuit, and a voltage recovery circuit. The input of the first control switch circuit is connected to the power supply voltage provided by the power module, its control terminal is connected to the MCU, and its output terminal is connected to the power supply terminal of the voltage recovery circuit. The input of the voltage injection circuit is connected to a diagnostic reference voltage, which is designed and output by the power module. The output of the voltage injection circuit is connected in series with a resistor to the detection harness, used to charge the injector through the resistor. The input of the voltage recovery circuit is connected to the detection harness, and its output terminal is connected to the MCU. When the MCU controls the first control switch circuit to be turned on, it recovers the signal after the injector voltage is injected and transmits the recovered voltage to the MCU.

[0029] The oscillation frequency acquisition unit includes a second control switch circuit, a matching resistor selection switch matrix, and an oscillator circuit. The input of the second control switch circuit is connected to the power supply voltage provided by the power module, its control terminal is connected to the MCU, and its output terminal is connected to the power supply terminals of the matching resistor selection switch matrix and the oscillator circuit. The input of the matching resistor selection switch matrix is ​​connected to the MCU, and its output terminal is connected to the resistor selection terminal of the oscillator circuit. This allows the MCU to select a suitable matching resistor and configure it for the oscillator circuit when controlling the second control switch circuit to conduct. The input of the oscillator circuit is connected to a detection harness, and its output terminal is connected to the MCU via an RC frequency detection circuit. This allows the oscillator circuit to generate an oscillation waveform in conjunction with the internal capacitor of the fuel injector when the MCU controls the second control switch circuit to conduct, and transmits the oscillation frequency acquired by the RC frequency detection circuit to the MCU.

[0030] In this embodiment, the first and second control switch circuits are designed with identical structures, using a MOSFET Q1, a transistor Q2, and three resistors. Their connection relationship is as follows: Figure 3 As shown. When the MCU needs to enter the fault state judgment or capacitor abnormality detection, it provides a valid level signal to transistor Q2, causing MOSFET Q1 to conduct, thereby transmitting the voltage provided by the voltage regulator circuit to the subsequent circuits.

[0031] In one possible implementation, a schematic diagram of the matching resistor selection switch matrix, oscillator circuit, and RC frequency detection circuit can be referenced. Figure 4 As shown, the matching resistor selection switch matrix is ​​implemented using two AD5171 digital potentiometers, each representing a multi-position matching resistor. Pins 4 and 5 of each digital potentiometer are connected to the MCU, and pin 8 (equivalent to the sliding end of the sliding resistor) is connected to the resistor selection terminal of the oscillator circuit (corresponding to pins 6 and 7). The MCU calculates the most suitable value for the oscillator circuit based on the expected value of the injector capacitor. , Match the resistor parameters and control the output of the two digital potentiometers to obtain the resistance value. The oscillator circuit uses a 555 timer multivibrator. When the oscillator is working, its 6th pin is used as the Connector_Out to connect to the fuel injector capacitor, and its 3rd pin is connected to the MCU through an RC frequency detection circuit.

[0032] When the MCU performs fault detection on the connected injectors, it first activates the voltage acquisition unit to enter the damage status judgment process. After identifying the specific damage status, it then considers whether to switch to the oscillation frequency acquisition unit to enter the capacitor abnormality detection process. The switching between units relies on the first and second control switch circuits. That is, after the MCU inputs a valid level signal to the first control switch circuit and an invalid level signal to the second control switch circuit, the MCU judges the damage status based on the voltage sampled by the voltage acquisition unit.

[0033] Under the damage condition judgment process, when the sampled voltage is 0V, the damage condition is determined to be an internal short circuit in the injector. The cause of the damage may be due to electrical breakdown of the injector. The MCU outputs the injector short circuit fault and related damage cause information to the display module for display. When the sampled voltage is not 0V, it is necessary to combine the expected value of the injector capacitor to determine the damage condition as an internal open circuit in the injector, or switch to the injector capacitor abnormality detection process to further determine the damage condition. Specifically, the damage condition is as follows: When the sampling voltage is not 0V, and the sampling voltage collected within the set sampling period is equal to the injection voltage provided by the voltage acquisition unit, the damage status is determined to be an internal open circuit in the injector (the reason is that the injector capacitance is basically zero, so it can be quickly charged to the injection voltage). The damage may be caused by aging of the injector circuit, loose connectors, or blown fuses. The MCU outputs the injector open circuit fault and related damage information to the display module for display.

[0034] When the sampling voltage is not 0V, and the sampling voltage collected within the set sampling period is less than the injection voltage provided by the voltage acquisition unit, it indicates that there are still capacitive parameters inside the injector. The cause of the damage may be due to injector aging, mechanical breakage, or other reasons that may cause abnormalities in the injection capacitor parameters. In this case, the MCU needs to enter the injector capacitor abnormality detection process and combine the results of subsequent capacitor tests to output the specific damage status.

[0035] In this embodiment, the length of the sampling period must be less than the expected value of the injector capacitance. The resistance value of the resistor connected to the voltage injection circuit in the voltage acquisition unit The product. For example, setting the sampling period to... .

[0036] Because piezoelectric crystal injectors have relatively small capacitance values, and different injectors have different capacitance parameters, common causes of damage such as aging and vibration can lead to changes in capacitance parameters, although these changes are relatively small. This makes injector capacitance anomaly detection technically challenging. To address these issues, this embodiment provides an injector capacitance anomaly detection procedure, specifically including: a) When it is necessary to detect abnormality of injector capacitor, the MCU shuts down the voltage acquisition unit and enables the oscillation frequency acquisition unit. That is, after the MCU inputs an invalid level signal to the first control switch circuit and an effective level signal to the second control switch circuit, the oscillation frequency acquisition unit works.

[0037] b) Based on the expected value of the injector capacitor, the MCU calculates the most reasonable oscillator circuit. , Matching resistor parameters include: the oscillation frequency of the oscillator circuit. and duty cycle (45%~55% recommended, while also considering drive efficiency) The formula is:

[0038]

[0039] In the given The value can be derived from this. , To simplify the design, the relationship can be made = .Will , Relationship formula, expected value of different injector capacitors and target oscillation frequency Substituting the values ​​into the above frequency calculation formula, the optimal frequency for different injectors can be calculated. , Matching resistor parameters to create a multi-range matching resistor table (adapting to different resistors). The value is stored in the MCU. When the MCU determines the injector model based on the information input from the operation panel buttons, it obtains the expected value of the corresponding injector capacitor. Then, the MCU selects a matching resistor from the multi-range matching resistor table. , This, in turn, controls the matching resistor selection switch matrix to adjust to this resistor parameter and configures it to the oscillator circuit. The oscillator circuit then operates, working in conjunction with the internal capacitor of the fuel injector. An oscillation waveform is generated, and the oscillation frequency is then acquired by the RC frequency detection circuit and transmitted to the MCU.

[0040] In this embodiment, a resistance selection matrix is ​​designed to address the different capacitor parameters of different injectors. By adjusting the resistance selection, the accuracy of injector capacitor testing can be improved.

[0041] c) The MCU calculates the current capacitance value of the injector based on the oscillation frequency, which is the actual data collected. Substituting into the frequency calculation formula above, under the given... , The current capacity of the injector can be calculated at that time.

[0042] d) The MCU compares the current capacitance value of the injector with the expected capacitance value to determine if there is any abnormality in the injector capacitance parameter, and transmits this information to the display module for display. Specifically, if the current capacitance value of the injector is less than the expected capacitance value, an injector capacitance abnormality fault is output to the display module interface; if the current capacitance value of the injector is equal to the expected capacitance value, an injector capacitance normality is output to the display module interface; if the current capacitance value of the injector is greater than the expected capacitance value, a detection device fault is output to the display module interface.

[0043] Based on the same inventive concept, one embodiment of this application also provides a method for detecting damage to a piezoelectric crystal injector. This method is integrated within the MCU of the piezoelectric crystal injector damage detection device described above. Figure 5 As shown, the specific steps include the following: Step 502: Real-time acquisition of the voltage and oscillation frequency of the piezoelectric crystal injector connected to the detection device.

[0044] Step 504: Based on the currently input injector model information, retrieve the corresponding injector capacitor expected value, and combine it with voltage and oscillation frequency to perform fault detection on the connected injector, and determine the injector's damage status and cause of damage.

[0045] It should be noted that the solution provided by this method is similar to the solution described in the above-mentioned detection device. Therefore, the specific limitations of steps 502 and 504 can be found in the limitations of the piezoelectric crystal injector damage detection device described above, and will not be repeated here.

[0046] The above descriptions are merely preferred embodiments of this application, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A piezoelectric crystal fuel injector damage detection device, characterized in that, The device includes: The detection harness is used to connect the piezoelectric crystal injector interface and the parameter acquisition module; The parameter acquisition module is used to acquire the voltage and oscillation frequency of the injector; The operation input module is used to provide information on different injector models; The MCU is used to retrieve the corresponding expected value of the injector capacitor based on the currently input injector model information, and, in conjunction with the voltage and oscillation frequency provided by the parameter acquisition module, to perform fault detection on the connected injector and determine the damage status of the injector. A power module is used to provide the required voltage to the various modules inside the device. The display module is used to show the damage status and parameter information of the injector.

2. The piezoelectric crystal injector damage detection device according to claim 1, characterized in that, The parameter acquisition module includes components connected to the MCU: The voltage acquisition unit is used to inject voltage into the connected injector and collect the voltage signal, and transmit the collected injector voltage to the MCU for damage status judgment. The oscillation frequency acquisition unit is used to generate an oscillation waveform that meets the requirements of the injector drive, and transmits the acquired injector oscillation frequency to the MCU for capacitor abnormality detection.

3. The piezoelectric crystal injector damage detection device according to claim 2, characterized in that, The voltage acquisition unit includes a first control switch circuit, a voltage injection circuit, and a voltage recovery circuit, wherein: The input terminal of the first control switch circuit is connected to the power supply voltage provided by the power module, the control terminal is connected to the MCU, and the output terminal is connected to the power supply terminal of the voltage feedback circuit. The input terminal of the voltage injection circuit is connected to the reference voltage provided by the power module, and the output terminal is connected in series with a resistor to the detection harness for charging the injector through the resistor. The input terminal of the voltage recovery circuit is connected to the detection harness, and the output terminal is connected to the MCU. It is used to recover the signal after the injector voltage is injected when the MCU controls the first control switch circuit to be turned on, and transmit the recovered voltage to the MCU.

4. The piezoelectric crystal injector damage detection device according to claim 2, characterized in that, The oscillation frequency acquisition unit includes a second control switch circuit, a matching resistor selection switch matrix, and an oscillator circuit, wherein: The input terminal of the second control switch circuit is connected to the power supply voltage provided by the power module, the control terminal is connected to the MCU, and the output terminal is connected to the power supply terminal of the matching resistor selection switch matrix and the oscillator circuit. The input terminal of the matching resistor selection switch matrix is ​​connected to the MCU, and the output terminal is connected to the resistor selection terminal of the oscillator circuit. It is used to cooperate with the MCU to select a suitable matching resistor and configure it to the oscillator circuit when the MCU controls the second control switch circuit to be turned on. The input terminal of the oscillator circuit is connected to the detection harness, and the output terminal is connected to the MCU through the RC frequency detection circuit. When the MCU controls the second control switch circuit to be turned on, it is used to generate an oscillation waveform in conjunction with the internal capacitor of the fuel injector, and transmit the oscillation frequency collected by the RC frequency detection circuit to the MCU.

5. The piezoelectric crystal injector damage detection device according to claim 2, characterized in that, The step of fault detection of the connected injectors to determine the damage status of the injectors includes: The MCU enables the voltage acquisition unit. When the collected voltage is 0V, it determines that the damage is an internal short circuit in the injector and transmits the information to the display module for display. When the sampling voltage is not 0V, the damage status is determined by combining the expected value of the injector capacitor to be either an internal open circuit in the injector or an abnormality detection of the injector capacitor, and then transmitted to the display module for display. When the injector capacitor abnormality detection is performed, the MCU shuts down the voltage acquisition unit, enables the oscillation frequency acquisition unit, and calculates the current capacitance value of the injector based on the oscillation frequency. The MCU compares the current capacitance value of the injector with the expected capacitance value of the injector to determine whether there is any abnormality in the injector capacitance parameter, and then transmits the result to the display module for display.

6. The piezoelectric crystal injector damage detection device according to claim 5, characterized in that, When the sampling voltage is not 0V, the damage condition is determined by combining the expected value of the injector capacitor to be either an internal open circuit in the injector or an abnormality detection of the injector capacitor, including: When the sampling voltage is not 0V, and the sampling voltage collected within the set sampling period is equal to the injection voltage provided by the voltage acquisition unit, the damage condition is determined to be an internal open circuit of the injector. When the sampling voltage is not 0V, and the sampling voltage collected within the set sampling period is less than the injection voltage provided by the voltage acquisition unit, the MCU enters the abnormal detection of the injector capacitor. Wherein, the length of the set sampling period is less than the product of the expected value of the injector capacitor and the resistance value of the resistor connected to the voltage injection circuit in the voltage acquisition unit.

7. The piezoelectric crystal injector damage detection device according to claim 5, characterized in that, The MCU compares the current capacitance value of the injector with the expected capacitance value of the injector to determine whether there is an abnormality in the injector capacitance parameter. The MCU's judgment logic includes: If the current capacitance value of the injector is less than the expected value of the injector capacitance, the injector capacitance is determined to be abnormal. If the current capacitance value of the injector is equal to the expected value of the injector capacitance, then the injector capacitance is determined to be normal. If the current capacitance value of the injector is greater than the expected value of the injector capacitance, the device is determined to be faulty.

8. The piezoelectric crystal injector damage detection device according to claim 1, characterized in that, The operation input module includes: The control panel provides an operation and control interface, with buttons arranged to represent different injector models; A button sensor is used to sense button signals on the operation panel and convert the button signals into electrical signals. The sensor detection circuit is used to filter the electrical signal output by the button sensor and transmit it to the MCU.

9. The piezoelectric crystal injector damage detection device according to claim 1, characterized in that, The power module includes: Power port protection circuit, used to protect against and filter abnormalities in the raw voltage supplied by external power supply; A voltage regulator circuit is used to step down the filtered voltage output by the power port protection circuit or the voltage provided by the internal battery to provide the voltage required by each module. The internal battery is connected to the voltage regulator circuit; When there is an external power input, the internal battery is charged through the voltage regulator circuit, and when there is no external power input, the internal battery powers the voltage regulator circuit.

10. A method for detecting damage to a piezoelectric crystal fuel injector, characterized in that, The method is integrated within the MCU of the piezoelectric crystal injector damage detection device as described in any one of claims 1-9, and includes: Real-time acquisition of the voltage and oscillation frequency of the piezoelectric crystal fuel injector connected to the device; Based on the currently input injector model information, retrieve the corresponding injector capacitor expectation value, and combine it with the voltage and oscillation frequency to perform fault detection on the connected injector and determine the damage status of the injector.

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