Method and device for detecting failure of urea injector, exhaust treatment system and vehicle

Abstract

The application discloses a fault detection method and device of a urea injector, an exhaust treatment system and a vehicle. The fault detection method comprises the following steps: acquiring a current working state of the urea injector; acquiring electric energy data of a control loop of the injector; and determining a fault state of the urea injector according to the current working state and the electric energy data. The method can detect the fault state of the injector in time, improve the injection precision of the urea injector, and avoid the problem that the nitrogen oxides in the exhaust exceed the standard due to the influence of the injection precision of the urea injector.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of urea injectors, in particular to a fault detection method and device of a urea injector, an exhaust treatment system and a vehicle. BACKGROUND

[0002] In the related art, the urea injector sprays according to the urea demand value of the urea injector calculated by the engine controller to reduce nitrogen oxides in the exhaust gas, but when the urea injector fails, the spraying accuracy of the urea injector is affected, thereby causing the problem of excessive nitrogen oxides in the exhaust gas. SUMMARY

[0003] The present application aims to solve at least one of the technical problems in the prior art. To this end, one object of the present application is to provide a fault detection method for a urea injector, which can detect the fault condition of the injector in time to improve the spraying accuracy of the urea injector, thereby avoiding the problem of excessive nitrogen oxides in the exhaust gas due to the influence of the spraying accuracy of the urea injector.

[0004] A second object of the present application is to provide a fault detection device for a urea injector.

[0005] A third object of the present application is to provide an exhaust treatment system.

[0006] A fourth object of the present application is to provide a vehicle.

[0007] To solve the above problems, the first aspect of the present application provides a fault detection method for a urea injector, which is used in an exhaust treatment system, the exhaust treatment system comprising an injector control loop, the urea injector being arranged in the injector control loop, the fault detection method comprising: acquiring a current working state of the urea injector; acquiring electrical energy data of the injector control loop; and determining a fault state of the urea injector according to the current working state and the electrical energy data.

[0008] The fault detection method for a urea injector according to the present application monitors the fault state of the urea injector through the electrical energy data of the injector control loop for different current working states of the urea injector, so that the fault condition of the injector can be detected in time in different working states, so as to timely remind the user to repair the fault condition of the urea injector, thereby improving the spraying accuracy of the urea injector and avoiding the problem of excessive nitrogen oxides in the exhaust gas due to the influence of the spraying accuracy of the urea injector.

[0009] In some embodiments, the injector control loop includes a voltage regulator for providing a constant voltage to the urea injector and a driver for collecting the electrical energy data. Before obtaining the current operating status of the urea injector, the fault detection method further includes: controlling the voltage regulator to start, and controlling the driver to start after a preset time.

[0010] In some embodiments, the electric energy data includes at least a positive electrode voltage of the urea injector, and determining a fault state of the urea injector according to the current working state and the electric energy data includes: determining that the current working state is an activated state; and determining the fault state of the urea injector according to the positive electrode voltage.

[0011] In some embodiments, determining the fault state of the urea injector according to the positive electrode voltage includes: if the positive electrode voltage is lower than a first preset threshold, determining that the fault state of the urea injector is a short circuit fault to ground; if the positive electrode voltage is higher than a second preset threshold, determining that the fault state of the urea injector is a short circuit fault to power supply; if the positive electrode voltage is higher than the first preset threshold and lower than the second preset threshold, determining that the positive electrode of the urea injector is in a normal state.

[0012] In some embodiments, the electric energy data includes at least a cathode voltage of the urea injector, and determining a fault state of the urea injector according to the current working state and the electric energy data includes: determining that the current working state is an activated state; and determining the fault state of the urea injector according to the cathode voltage.

[0013] In some embodiments, determining the fault state of the urea injector according to the cathode voltage includes: if the cathode voltage is lower than a first preset threshold, determining that the fault state of the urea injector is an open circuit fault; if the cathode voltage is higher than a second preset threshold, determining that the fault state of the urea injector is a short circuit fault to a power supply; if the cathode voltage is higher than the first preset threshold and lower than the second preset threshold, determining that the cathode of the urea injector is in a normal state.

[0014] In some embodiments, the injector control circuit includes a first resistor, a second resistor, a first switch, and a second switch, the first resistor, the urea injector, and the second resistor are connected in series in sequence, the first switch is connected in parallel with the first resistor, and the second switch is connected in parallel with the second resistor. The fault detection method further includes: upon receiving an injection control instruction, controlling the urea injector to enter an action state, wherein in the action state, the first switch and the second switch are controlled to be periodically closed.

[0015] In some embodiments, the electric energy data at least comprises working current of the injector control loop, and determining the fault state of the urea injector according to the current working state and the electric energy data comprises: determining that the current working state is an action state; and determining the fault state of the urea injector according to the working current.

[0016] In some embodiments, determining the fault state of the urea injector according to the working current comprises: if the working current is higher than a preset current value, determining that the fault state of the urea injector is a positive and negative electrode short circuit fault; and if the working current is lower than the preset current value, determining that the urea injector is in a normal state.

[0017] The second aspect of the present application provides a fault detection device of a urea injector, which is used in an exhaust treatment system, the exhaust treatment system comprising an injector control loop, and the urea injector being arranged in the injector control loop, the fault detection device comprising: a first acquisition module configured to acquire a current working state of the urea injector; a second acquisition module configured to acquire electric energy data of the injector control loop; and a determination module configured to determine a fault state of the urea injector according to the current working state and the electric energy data.

[0018] The fault detection device of the urea injector according to the embodiments of the present application, the determination module monitors the fault state of the urea injector through the electric energy data of the injector control loop for different current working states of the urea injector, so that the fault condition of the injector can be detected in time in different working states, so as to timely remind the user to maintain the urea injector for the fault condition, thereby improving the injection accuracy of the urea injector and avoiding the problem of exceeding the nitrogen oxides in the exhaust gas due to the influence of the injection accuracy of the urea injector.

[0019] The third aspect of the present application provides an exhaust treatment system, comprising: an injector control loop; a urea injector arranged in the injector control loop; and a controller connected with the injector control loop and configured to execute the fault detection method of the urea injector according to the above embodiments.

[0020] The exhaust treatment system according to the embodiments of the present application can detect the fault condition of the injector in time by executing the fault detection method of the urea injector according to the above embodiments, so as to improve the injection accuracy of the urea injector and avoid the problem of exceeding the nitrogen oxides in the exhaust gas due to the influence of the injection accuracy of the urea injector.

[0021] In some embodiments, the injector control loop comprises: a voltage regulator configured to provide a constant voltage for the urea injector; and a driver configured to collect the electric energy data.

[0022] In some embodiments, the injector control circuit comprises a first resistor, a second resistor, a first switch and a second switch, the first resistor, the urea injector and the second resistor are connected in series, the first switch is connected in parallel with the first resistor, and the second switch is connected in parallel with the second resistor.

[0023] An embodiment of the fourth aspect of the present application provides a vehicle comprising the exhaust treatment system as described in the above embodiments.

[0024] According to the vehicle of the embodiments of the present application, the failure of the injector can be detected in time through the exhaust treatment system as described in the above embodiments, so as to improve the injection accuracy of the urea injector, thereby avoiding the problem that the nitrogen oxides in the exhaust gas exceed the standard due to the influence of the injection accuracy of the urea injector.

[0025] Additional aspects and advantages of the present application will be given in part in the following description, become apparent from the following description, or be understood through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a schematic diagram of an exhaust treatment system according to an embodiment of the present application;

[0028] Figure 2 is a flow chart of a failure detection method of a urea injector according to an embodiment of the present application;

[0029] Figure 3 is a schematic diagram of voltage variation when a voltage regulator and a driver are started according to an embodiment of the present application;

[0030] Figure 4 is a flow chart of a failure detection method of a urea injector according to another embodiment of the present application;

[0031] Figure 5 is a structural block diagram of a failure detection device according to an embodiment of the present application;

[0032] Figure 6 is a structural block diagram of an exhaust treatment system according to an embodiment of the present application;

[0033] Figure 7 is a structural block diagram of a vehicle according to an embodiment of the present application.

[0034] REFERENCE SIGNS:

[0035] vehicle 100; exhaust treatment system 90; failure detection device 80;

[0036] injector control circuit 1; urea injector 2; controller 3; voltage regulator 11; driver 12; first resistor R1; second resistor R2; first switch S1; second switch S2; first acquisition module 4; second acquisition module 5; determination module 6. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments of the present application described below with reference to the accompanying drawings are exemplary.

[0038] To solve the above problems, the first aspect of the present application provides a urea injector fault detection method, which is used in an exhaust treatment system. The method can detect the fault of the injector in time, improve the injection accuracy of the urea injector, and avoid the problem of exceeding the nitrogen oxide in the exhaust gas due to the influence of the injection accuracy of the urea injector.

[0039] In the embodiments, as shown in FIG. 1, the exhaust treatment system 90 includes an injector control circuit 1, and a urea injector 2 is arranged in the injector control circuit. Figure 1

[0040] The urea injector fault detection method according to the embodiments of the present application is described below with reference to FIG. 2. As shown in FIG. 2, the fault detection method at least includes steps S1-S3. Figure 2 Figure 2 Step S1: Acquire the current working state of the urea injector.

[0041] Specifically, the exhaust treatment system acquires the current working state of the urea injector.

[0042] Specifically, the exhaust treatment system acquires the current working state of the urea injector.

[0043] Step S2: Acquire the electrical energy data of the injector control circuit.

[0044] Specifically, the exhaust treatment system acquires the electrical energy data of the injector control circuit, wherein the electrical energy data at least includes voltage data and current data, etc., which is not limited.

[0045] Step S3: Determine the fault state of the urea injector according to the current working state and the electrical energy data.

[0046] ​​Specifically, in the related art, the urea injector sprays according to the urea demand value of the urea injector calculated by the engine controller to reduce nitrogen oxides in the exhaust gas, but when the urea injector fails, the spraying accuracy of the urea injector is affected, thereby causing the problem of excessive nitrogen oxides in the exhaust gas. In order to solve this problem, in the process of starting and driving the vehicle, the failure of the injector is detected in time in the present application through the current working state and the electric energy data, so as to improve the spraying accuracy of the urea injector, so that the spraying amount of the urea injector will not deviate, thereby avoiding the problem of excessive nitrogen oxides in the exhaust gas. That is, for the current working state of the urea injector, the failure state of the urea injector is monitored through the electric energy data of the injector control loop, for example, the failure state of the urea injector is monitored through the size of the voltage data and the current data of the injector control loop, so that when the urea injector fails, the failure of the urea injector can be detected in time and accurately, so as to timely remind the user to repair the failure of the urea injector, thereby improving the spraying accuracy of the urea injector, and further avoiding the problem of excessive nitrogen oxides in the exhaust gas caused by the influence of the spraying accuracy of the urea injector. In addition, since the user is reminded in time to repair the failure of the urea injector, the failure is avoided from being upgraded to affect the user's use of the vehicle, the repair time and cost are reduced, and the occurrence of incomplete repair is reduced.

[0047] According to the urea injector failure detection method of the embodiment of the present application, for different current working states of the urea injector, the failure state of the urea injector is monitored through the electric energy data of the injector control loop, so that the failure of the injector can be detected in time in different working states, so as to timely remind the user to repair the failure of the urea injector, thereby improving the spraying accuracy of the urea injector and avoiding the problem of excessive nitrogen oxides in the exhaust gas caused by the influence of the spraying accuracy of the urea injector.

[0048] In some embodiments, the injector control loop includes a voltage regulator for providing a constant voltage to the urea injector and a driver for collecting electric energy data, such as Figure 3As shown, the voltage output to the urea injector by the exhaust treatment system increases from 0 to a set voltage value in the initial stage of power-on, in order to ensure that the urea injector is provided with a constant voltage each time it is powered on, before obtaining the current working state of the urea injector, the control voltage regulator is started to adjust the supply voltage of the urea injector, for example, the voltage regulator is mainly applied when the voltage is unstable in the first power-on, to provide a constant voltage for the urea injector, thereby adjusting the supply voltage of the urea injector by increasing the voltage regulator in the injector control loop, to avoid the problem of false failure of the urea injector caused by unstable voltage in the initial stage of power-on, and after a preset time, the driver is controlled to start, that is, after the voltage regulator is started for a period of time, that is, after the supply voltage is in a stable state, the driver is controlled to start, and the driver collects the power data of the injector control loop, to ensure that constant power data can be obtained, thereby avoiding false judgment of the failure of the urea injector due to the power information in the initial stage of power-on. And it needs to be noted that the start time of the voltage regulator should be earlier than that of the driver, so as to ensure that the driver can obtain constant power data.

[0049] In addition, the engine controller supplies power to the controller of the exhaust treatment system through the relay, and the controller provides a constant voltage of 12V for the urea injector after adjustment by the voltage regulator, which is not limited. The vehicle battery can also be used to provide the required power for the exhaust treatment system, and the normal voltage of the battery is 12V.

[0050] In some embodiments, the power data at least includes the positive electrode voltage of the urea injector, and the failure state of the urea injector is determined according to the current working state and the power data, that is, if the current working state of the urea injector is determined to be the active state, that is, if the current working state of the urea injector is determined to be only the power-on state, the failure state of the urea injector is determined according to the positive electrode voltage of the urea injector collected by the driver, thereby realizing the failure detection of the urea injector in the active state.

[0051] In some embodiments, the current working state of the urea injector is the active state after the vehicle is powered on, the fault state of the urea injector is determined according to the positive voltage, the positive voltage of the urea injector collected by the driver is very large when the urea injector has a short circuit to the power supply fault, the positive voltage is the power supply voltage of the exhaust treatment system, and the positive voltage of the urea injector when the short circuit to the power supply fault is larger than the positive voltage in the normal state, and the positive voltage of the urea injector collected by the driver is very low and almost zero when the short circuit to ground fault occurs, so in this application, a preset threshold for detecting the fault state of the urea injector is set in the exhaust treatment system, and the positive voltage of the injector control loop collected by the driver is compared with the preset threshold to determine the fault state of the urea injector, that is, if the positive voltage is lower than the first preset threshold, wherein the first preset threshold is a voltage value calibrated according to the short circuit to ground fault of the urea injector, for example, the first preset threshold is 1V, and the positive voltage of the urea injector is very low at this time, then the fault state of the urea injector is determined to be a short circuit to ground fault; if the positive voltage is higher than the second preset threshold, wherein the second preset threshold is a voltage value calibrated according to the short circuit to the power supply fault of the urea injector, for example, the second preset threshold is 4V, and the positive voltage of the urea injector is very high at this time, then the fault state of the urea injector is determined to be a short circuit to the power supply fault; if the positive voltage is higher than the first preset threshold and lower than the second preset threshold, that is, the positive voltage of the urea injector is in the normal positive voltage range, then the positive voltage of the urea injector is in the normal state. Thus, the fault detection of the urea injector in the active state is realized.

[0052] In addition, the first preset threshold and the second preset threshold can be adjusted according to the actual situation of the whole vehicle.

[0053] In some embodiments, the electrical energy data at least includes the negative voltage of the urea injector, and the fault state of the urea injector is determined according to the current working state and the electrical energy data, that is, if it is determined that the current working state of the urea injector is the active state, that is, if it is determined that the current working state of the urea injector is only the powered state, then the fault state of the urea injector is determined according to the negative voltage of the urea injector collected by the driver. Thus, the fault detection of the urea injector in the active state is realized.

[0054] In some embodiments, when the current working state of the urea injector is the activated state, the fault state of the urea injector is determined based on the negative electrode voltage. Since the resistance value in the injector control loop is much larger than the resistance value of the urea injector, the partial pressure of the urea injector in the injector control loop is small, and the voltage drop generated at both ends of the urea injector is small, and the voltage drop is almost negligible compared to the preset threshold value. Therefore, when the urea injector is in a normal state, the negative electrode voltage of the urea injector collected by the driver is almost equal to the positive electrode voltage, that is, the power supply voltage of the exhaust gas treatment system. For example, the negative electrode voltage and the positive electrode voltage of the urea injector are both 3.8V. Therefore, when the urea injector has an open circuit fault, the negative electrode voltage is lower than the negative electrode voltage in the normal state. Therefore, this invention The application sets a preset threshold for detecting urea injector faults in the exhaust gas treatment system. The fault status of the urea injector is determined by comparing the negative electrode voltage of the injector control circuit, as measured by the driver, with the preset threshold. Specifically, if the negative electrode voltage is lower than a first preset threshold (i.e., the negative electrode voltage of the urea injector is low), the urea injector fault is determined to be an open circuit fault. If the negative electrode voltage is higher than a second preset threshold (i.e., the negative electrode voltage of the urea injector is high), the urea injector fault is determined to be a short circuit to the power supply. If the negative electrode voltage is higher than the first preset threshold but lower than the second preset threshold (i.e., the negative electrode voltage is within the normal negative electrode voltage range of the urea injector), the urea injector fault is determined to be normal. This enables fault detection of the urea injector while it is activated. Furthermore, the preset thresholds for detecting urea injector faults can be different for the negative electrode voltage and the positive electrode voltage of the injector control circuit.

[0055] In the embodiment, after the vehicle has been running for a period of time, urea injection is required when the exhaust temperature and the nitrogen oxide concentration in the exhaust gas reach a threshold value, and the vehicle engine controller will send an injection control instruction. Therefore, the fault detection of the urea injector in the activated state can be completed within one minute at the beginning of power-on, and the fault detection of the urea injector in the activated state will continue.

[0056] In some embodiments, as Figure 1 As shown, the injector control circuit 1 includes a first resistor R1, a second resistor R2, a first switch S1 and a second switch S2. The first resistor R1, the urea injector 2 and the second resistor R2 are connected in series in sequence. The first switch S1 is connected in parallel with the first resistor R1, and the second switch S2 is connected in parallel with the second resistor R2. The fault detection method further includes: upon receiving an injection control instruction, controlling the urea injector to enter an action state, wherein in the action state, controlling the first switch and the second switch to be periodically closed.

[0057] Specifically, the vehicle needs to perform urea injection when the exhaust temperature and the concentration of nitrogen oxides in the exhaust gas reach a threshold value after a period of operation, the vehicle engine controller sends an injection control instruction, and the exhaust treatment system controls the urea injector to enter an active state after receiving the injection control instruction, that is, controls the urea injector to spray urea. Since the urea injector is in the active state, the urea injector controls the urea injection and the size of the injection amount by opening and closing the internal valve body and the length of time, that is, the opening and closing of the urea injector and the length of time of the opening and closing can control the urea injection and the size of the injection amount. Therefore, the first switch and the second switch are periodically closed in the active state to control the urea injection and the size of the injection amount to meet the needs of the exhaust treatment system for urea injection and the size of the injection amount. In addition, the length of time when the first switch and the second switch are closed is proportional to the size of the injection amount, and when the first switch and the second switch are periodically closed, the frequency is generally any frequency between 2HZ and 4HZ, and the positive voltage of the urea injector is 12V and the negative voltage is 0V when the first switch and the second switch are in the closed state. This is not limited.

[0058] In an embodiment, the active state only occurs when the engine controller has an injection requirement and the controller of the exhaust treatment system commands the nozzle to perform the injection phase.

[0059] In some embodiments, the electrical energy data at least includes the working current of the injector control circuit, and the fault state of the urea injector is determined according to the current working state and the electrical energy data, including: determining that the current working state is the active state; and determining the fault state of the urea injector according to the working current. Specifically, when the current working state of the urea injector is the active state, the fast closing of the first switch and the second switch will cause the dynamic change of the two-pole voltage of the urea injector, and the working current of the injector control circuit is relatively stable. Therefore, the fault state of the urea injector is determined by the size of the working current, thereby realizing the fault detection of the urea injector in the active state.

[0060] In an embodiment, the controller controls the operation of the urea pump to transport the urea solution through the delivery pipe to the nozzle end for injection.

[0061] In some embodiments, when the current working state of the urea injector is the action state, the fault state of the urea injector is determined according to the working current, since the working current when the urea injector has the positive and negative electrode short circuit fault is much larger than the working current when the urea injector is normal, therefore, in the exhaust treatment system, a preset current value for detecting the fault state of the urea injector is set in the application, by comparing the working current of the injector control loop collected by the driver with the preset current value, the fault state of the urea injector is judged, that is, if the working current is higher than the preset current value, wherein the preset current value is a current threshold value calibrated according to the positive and negative electrode short circuit fault of the urea injector, and the preset current value can be adjusted according to the actual situation of the whole vehicle, such as the preset current value is 3.8A, which is not limited, then it is determined that the fault state of the urea injector is the positive and negative electrode short circuit fault; if the working current is lower than the preset current value, at this time the working current of the injector control loop is in the normal current range, then it is determined that the urea injector is in the normal state. Thus the fault detection of the urea injector in the action state is realized.

[0062] In the embodiments, if the fault state of the urea injector in different working states is detected, the fault condition is reported through the instrument alarm to remind the user to repair the fault condition of the urea injector in time.

[0063] In the embodiments, when the fault state of the urea injector in different working states is detected for a plurality of times such as three times in a cycle, the fault condition is reported.

[0064] The fault detection method of the urea injector of the embodiments of the application will be illustrated below with reference to the accompanying drawings. Figure 4

[0065] Step S4, start.

[0066] Step S5, the positive electrode voltage of the injector control loop collected by the driver, when the current working state of the urea injector is the activation state, whether the positive electrode voltage is greater than the first preset threshold value is judged, if yes, step S7 is executed, otherwise step S6 is executed.

[0067] Step S6, it is determined that the fault state of the urea injector is the short circuit fault to the ground.

[0068] Step S7, whether the positive electrode voltage is greater than the second preset threshold value is judged, if yes, step S8 is executed, otherwise step S9 is executed.

[0069] Step S8, it is determined that the fault state of the urea injector is the short circuit fault to the power supply.

[0070] Step S9, the negative electrode voltage of the urea injector collected by the driver is collected, whether the negative electrode voltage is greater than the first preset threshold value is judged, if yes, step S11 is executed, otherwise step S10 is executed.​

[0071] If yes, step S10, it is determined that the fault state of the urea injector is an open circuit fault.

[0072] If yes, step S11, it is determined whether the negative electrode voltage is greater than a second preset threshold value, if yes, step S8 is executed, otherwise, step S12 is executed.

[0073] If yes, step S12, it is determined that the positive electrode or the negative electrode of the urea injector is in a normal state, and the fault state of the urea injector in the action state is monitored.

[0074] If yes, step S13, the driver collects the working current of the injector control circuit, and when the current working state of the urea injector is the action state, it is determined whether the working current is lower than a preset current value, if yes, step S15 is executed, otherwise, step S14 is executed.

[0075] If yes, step S14, it is determined that the fault state of the urea injector is a positive and negative electrode short circuit fault.

[0076] If yes, step S15, it is determined that the urea injector is in a normal state.

[0077] If yes, step S16, it is ended.

[0078] The second aspect embodiment of the present application provides a fault detection device of a urea injector, which is used in an exhaust treatment system, such as Figure 1 As shown in the figure, the exhaust treatment system 90 includes an injector control circuit 1, and a urea injector 2 is arranged in the injector control circuit 1, as shown in the figure. Figure 5 As shown in the figure, the fault detection device 90 includes a first acquisition module 4, a second acquisition module 5 and a determination module 6.

[0079] The first acquisition module 4 is used for acquiring the current working state of the urea injector, the second acquisition module 5 is used for acquiring the electrical energy data of the injector control circuit, and the determination module 6 is used for determining the fault state of the urea injector according to the current working state and the electrical energy data.

[0080] According to the fault detection device of the urea injector provided by the embodiment of the present application, the determination module monitors the fault state of the urea injector through the electrical energy data of the injector control circuit according to different current working states of the urea injector, so that the fault condition of the injector can be detected in time in different working states, so as to timely remind the user to maintain the urea injector according to the fault condition of the urea injector, thereby improving the injection accuracy of the urea injector and avoiding the problem that the nitrogen oxides in the exhaust gas exceed the standard due to the influence of the injection accuracy of the urea injector.

[0081] The third aspect embodiment of the present application provides an exhaust treatment system 90, as shown in the figure. Figure 1 and Figure 6As shown, the tail gas treatment system comprises: an injector control circuit 1, a urea injector 2 and a controller 3.

[0082] The urea injector 2 is arranged in the injector control circuit 1; the controller 3 is connected with the injector control circuit 1 and is used for executing the fault detection method of the urea injector in the above embodiment. In addition, the controller 3 can interact with the engine controller, and the controller 3 controls the urea injector.

[0083] It should be noted that the specific implementation mode of the tail gas treatment system in the embodiment of the present application is similar to the specific implementation mode of the fault detection method of the urea injector in any of the above embodiments of the present application. For details, please refer to the description of the method part. In order to reduce redundancy, it will not be repeated here.

[0084] According to the tail gas treatment system in the embodiment of the present application, by executing the fault detection method of the urea injector in the above embodiment, the fault condition of the injector can be detected in time, so as to improve the injection accuracy of the urea injector, thereby avoiding the problem that the nitrogen oxides in the tail gas exceed the standard due to the influence of the injection accuracy of the urea injector.

[0085] In some embodiments, as shown in Figure 1 The injector control circuit 1 comprises: a voltage regulator 11 and a driver 12.

[0086] The voltage regulator 11 is used to provide a constant voltage for the urea injector; the driver 12 is used to collect power data. The selection of the driver 12 chip needs to be judged according to the actual demand.

[0087] Specifically, in order to ensure that a constant voltage is provided for the urea injector each time the power is turned on, before obtaining the current working state of the urea injector, the control voltage regulator is started to adjust the power supply voltage of the urea injector to provide a constant voltage for the urea injector, thereby avoiding the problem of false failure of the urea injector caused by unstable voltage in the initial stage of power-on of the vehicle, and after a preset time, the driver is controlled to start, and the driver collects the power data of the injector control circuit to ensure that constant power data can be output, thereby avoiding the false judgment of the fault condition of the urea injector due to the reception of power information in the initial stage of power-on.

[0088] In some embodiments, as shown in Figure 1 The injector control circuit 1 comprises: a first resistor R1, a second resistor R2, a first switch SI and a second switch S2. The first resistor R1, the urea injector 2 and the second resistor R2 are connected in series, the first switch SI is connected in parallel with the first resistor R1, and the second switch S2 is connected in parallel with the second resistor R2.

[0089] Specifically, when the current working state of the urea injector is the active state, the first switch and the second switch are in the open state; when the current working state of the urea injector is the action state, the control of the urea injection and the size of the injection amount can be realized by controlling the switches of the urea injector and the length of time of the switches, that is, by controlling the periodic closing of the first switch and the second switch, thereby realizing the control of the urea injection and the size of the injection amount to meet the demand of the exhaust treatment system on the urea injection and the urea injection amount. In addition, the resistance values of the first resistor and the second resistor are much larger than the resistance value of the urea injector.

[0090] The fourth aspect embodiment of the present application provides a vehicle 100, as shown in the figure, which comprises the exhaust treatment system 90 described in the above embodiments. Figure 7

[0091] According to the vehicle of the embodiments of the present application, the failure of the injector can be detected in time through the exhaust treatment system in the above embodiments, so as to improve the injection accuracy of the urea injector, thereby avoiding the problem of exceeding the nitrogen oxide in the exhaust gas due to the influence of the injection accuracy of the urea injector.

[0092] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0093] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.​

Claims

1. A method of failure detection of a urea injector, characterized in that, The application relates to a fault detection method for an exhaust treatment system, wherein the exhaust treatment system comprises an injector control circuit, and a urea injector is arranged in the injector control circuit; the injector control circuit comprises a first resistor, a second resistor, a first switch and a second switch; the first resistor, the urea injector and the second resistor are connected in series; the first switch is connected in parallel with the first resistor; the second switch is connected in parallel with the second resistor; the fault detection method comprises the following steps: acquiring a current working state of the urea injector; acquiring electric energy data of the injector control circuit; determining a fault state of the urea injector according to the current working state and the electric energy data; the fault detection method further comprises the following steps: receiving an injection control instruction, and controlling the urea injector to enter an action state; wherein, in the action state, the first switch and the second switch are controlled to be periodically closed.

2. The urea injector failure detection method according to claim 1, characterized in that, The injector control circuit comprises a voltage regulator for providing a constant voltage for the urea injector and a driver for collecting the electric energy data; before acquiring the current working state of the urea injector, the fault detection method further comprises the following steps: controlling the voltage regulator to start, and controlling the driver to start after a preset time.

3. The urea injector failure detection method according to claim 1 or 2, characterized in that, The electric energy data at least comprises a positive electrode voltage of the urea injector; determining the fault state of the urea injector according to the current working state and the electric energy data comprises the following steps: determining that the current working state is an active state; determining the fault state of the urea injector according to the positive electrode voltage.

4. The urea injector failure detection method according to claim 3, characterized in that, Determining the fault state of the urea injector according to the positive electrode voltage comprises the following steps: if the positive electrode voltage is lower than a first preset threshold value, determining that the fault state of the urea injector is a ground short circuit fault; if the positive electrode voltage is higher than a second preset threshold value, determining that the fault state of the urea injector is a power supply short circuit fault; if the positive electrode voltage is higher than the first preset threshold value and lower than the second preset threshold value, determining that the positive electrode of the urea injector is in a normal state.

5. The urea injector failure detection method according to claim 1, characterized in that, The electric energy data at least comprises a negative electrode voltage of the urea injector; determining the fault state of the urea injector according to the current working state and the electric energy data comprises the following steps: determining that the current working state is an active state; determining the fault state of the urea injector according to the negative electrode voltage.

6. The urea injector failure detection method according to claim 5, characterized in that, Determining the fault state of the urea injector according to the negative electrode voltage comprises the following steps: if the negative electrode voltage is lower than a first preset threshold value, determining that the fault state of the urea injector is an open circuit fault; if the negative electrode voltage is higher than a second preset threshold value, determining that the fault state of the urea injector is a power supply short circuit fault; if the negative electrode voltage is higher than the first preset threshold value and lower than the second preset threshold value, determining that the negative electrode of the urea injector is in a normal state.

7. The urea injector failure detection method according to claim 1, characterized in that, The electric energy data at least comprises a working current of the injector control circuit; determining the fault state of the urea injector according to the current working state and the electric energy data comprises the following steps: determining that the current working state is an action state; determining the fault state of the urea injector according to the working current.

8. The urea injector failure detection method according to claim 7, characterized in that, According to the working current, a fault state of the urea injector is determined, comprising: If the working current is higher than a preset current value, the fault state of the urea injector is determined as a positive and negative electrode short circuit fault; If the working current is lower than the preset current value, the urea injector is determined to be in a normal state.

9. A fault detection device for a urea injector, characterized in that For an exhaust treatment system, the exhaust treatment system comprises an injector control circuit, the urea injector is arranged in the injector control circuit, the injector control circuit comprises a first resistor, a second resistor, a first switch and a second switch, the first resistor, the urea injector and the second resistor are connected in series, the first switch is connected in parallel with the first resistor, and the second switch is connected in parallel with the second resistor, the exhaust treatment system controls the urea injector to enter an action state after receiving an injection control instruction, wherein in the action state, the first switch and the second switch are controlled to be periodically closed, and the fault detection device comprises: A first acquisition module is configured to acquire a current working state of the urea injector. A second acquisition module is configured to acquire electrical energy data of the injector control circuit. A determination module is configured to determine a fault state of the urea injector according to the current working state and the electrical energy data.

10. An off-gas treatment system characterized by, Comprise: An injector control circuit, the injector control circuit comprises a first resistor, a second resistor, a first switch and a second switch, the first resistor, the urea injector and the second resistor are connected in series, the first switch is connected in parallel with the first resistor, and the second switch is connected in parallel with the second resistor; A urea injector, the urea injector is arranged in the injector control circuit; A controller, the controller is connected with the injector control circuit, and is used for executing the fault detection method of the urea injector according to any one of claims 1-8.

11. The exhaust treatment system of claim 10, wherein, The injector control circuit comprises: A voltage regulator is configured to provide a constant voltage for the urea injector; A driver is configured to collect the electrical energy data.

12. A vehicle characterized by comprising: The exhaust treatment system of claim 10 or 11 is provided.

Images