Anomaly detection device

Abstract

Anomaly detection device for use in an exhaust gas purification system, which is arranged in an exhaust gas passage (31a) of an internal combustion engine (30) and comprises (a) an injection valve (50) for injecting a liquid reducing agent towards a NOx purification catalyst which purifies NOx in an exhaust gas, and (b) a pump (44) for compressing and supplying the reducing agent towards the injection valve via a reducing agent passage (42), wherein the anomaly detection device has: a acquisition section (S17) which obtains a pump speed in an injection state of the injector as an injection time speed (Np); and a determining device (S28) which determines, based on the injection time rotational speed (Np), whether the injection valve has an anomaly, wherein The determining device determines whether the injector has an anomaly based on a difference between (i) a required injection amount (Qo) of the injector and (ii) an actual injection amount (Qp) calculated from the injection time speed; The acquisition section obtains a pump speed in an injection-stop state of the injector, in which a drive signal (Sm) supplied to the injector (50) for opening and closing the injector (50) corresponds to an OFF voltage for closing the injector (50), as a non-injection-time speed (Ns) (S14), wherein a duration in which the drive signal (Sm) corresponds to the OFF voltage is an injection-stop duration (Ts), and the acquisition section obtains the pump speed in the injection-stop state of the injector (50) after the elapsed time (Tc) following the start of the injection-stop duration (Ts), if the injector (50) injects immediately before the injection-stop duration (Ts), and the predetermined duration (Tc) is set such that it is proportional to an injection duration (TP) with respect to the duration increases; the determining device calculates the actual injection amount from an increase (ΔN) of the injection time speed relative to the non-injection time speed (S20); the determining device, when the determining device determines that the injector has an anomaly, compares the non-injection time speed with a preset speed threshold (Nt) (S38); The determining device determines that the injector has an open-jaw anomaly that prevents the injector from closing when the non-injection-time speed is greater than the threshold (S40); and The determining device determines that the injector has a clamping anomaly when fully closed, in which the injector remains closed when the non-injection speed is lower than or equal to the threshold (S42).

Description

[0001] The present disclosure relates in general to an anomaly detection device for detecting anomalies in an injection valve in an exhaust gas purification system, comprising a pump and an injection valve.

[0002] In recent years, a urea SCR system (selective catalytic reduction) has been developed and mass-produced as an exhaust gas purification system for cleaning NOx (i.e., nitrogen oxides) in the exhaust gases of vehicle engines with a high cleaning rate, especially in diesel engines.

[0003] The urea SCR system comprises (i) a pump for pumping or conveying an aqueous urea solution, stored under pressure in a tank, to a reducing agent passage, and (ii) an injection valve for injecting the aqueous urea solution conveyed through the reducing agent passage into an exhaust line or exhaust pipe of the engine. The aqueous urea solution can also be referred to as urea water and can act as the reducing agent.

[0004] In the urea SCR system, the exhaust gas is cleaned by the reduction reaction of NOx on a NOx purification catalyst in the exhaust pipe. During NOx reduction, ammonia (NH3) is first generated by the hydrolysis of the urea solution injected into the exhaust pipe by the injection valve, using exhaust gas heat, and is then absorbed by the SCR catalyst. The NOx in the exhaust gas is reduced and cleaned by the reduction reaction with ammonia on the SCR catalyst.

[0005] In such a urea SCR system, the amount of urea injected can become abnormal if the operation of the injection valve is hindered by urea crystallization or by foreign matter introduced into the injection valve from the exhaust pipe side via an injection port. To counteract such a potential anomaly, Japanese patent number JP 4 964 353 B1 proposes a device for checking whether the injection valve is abnormal. Specifically, the device in JP 4 964 353 B1 checks for an anomaly in the injection valve by using a duty cycle (hereinafter referred to as the pump duty cycle) to control an electrical current supplied to the pump.JP 4 964 353 B1 describes in particular a device which determines the presence or absence of an anomaly in the injection valve based on a relationship between a pump duty cycle and an injection quantity of urea water, wherein the pressure in the urea water supply line is kept constant.

[0006] However, in the urea SCR system described in JP 4 964 353 B1, the presence or absence of an injector anomaly cannot be precisely determined. For example, in the process of estimating the injection quantity based on the pump duty cycle, when determining the injector anomaly using the pump duty cycle, the effective value of the current supplied to the pump is calculated from the pump duty cycle, and the amount of urea delivered by the pump (hereafter referred to as the "delivery quantity") is calculated based on the effective value. Since the pump varies the delivery quantity to compensate for the amount of urea solution injected by the injector, the injector's injection quantity is calculated based on the delivery quantity. That is, the injection quantity is calculated indirectly from the pump duty cycle.If an error occurs in calculating the effective current value based on the pump duty cycle, or if an error occurs in calculating the delivery amount based on the effective current value, it is therefore difficult to accurately determine the injection valve anomaly. Such a problem is not limited to situations using urea solution; it is also a common problem in other situations where fluids other than the reducing agent are used.

[0007] Furthermore, US 2017 / 0241315A1 discloses that in a case where an integrated value of a determination value correlates with an order value for a feed quantity of a reducing agent reaches an integration threshold at the time when the order value is greater than an order feed quantity threshold, a diagnostic condition is determined to be met, and an anomaly in the feed quantity of the reducing agent is diagnosed based on an integrated value of the order value for the feed quantity of the reducing agent and an integrated value of an estimated value of the feed quantity of the reducing agent, whereas in cases where a time interval during which the diagnostic condition is not met is longer than a time interval threshold, a feed interval of the reducing agent is extended.

[0008] Furthermore, DE 10 2008 043 469 A1 discloses a method for testing the functionality of a metering valve of a reducing agent system of an internal combustion engine, in which metering agent is conveyed from a tank to the metering valve by means of a controllable pump at constant pressure, which has the following steps: - the metering valve is acted upon with a control variable characterizing the induction of a change of state of the metering valve, - a quantity characterizing the delivery rate of the pump is recorded, - the functionality of the metering valve is inferred from the quantity characterizing the delivery rate.

[0009] It is an objective of the present disclosure to provide an anomaly detection device that is capable of adequately and accurately detecting the presence or absence of an anomaly in an injection valve.

[0010] The foregoing problem is solved by the subject matter of claim 1. Advantageous embodiments of the invention are the subject matter of the dependent claims that follow.

[0011] An anomaly detection device according to an explanatory aspect of the present disclosure is used in an exhaust gas purification system. The exhaust gas purification system comprises an injection valve provided in an exhaust port or exhaust pipe of an internal combustion engine to inject a liquid reducing agent into a NOx purification catalyst for the purpose of removing NOx from the exhaust gas. The exhaust gas purification system also comprises a pump that compresses the reducing agent and delivers it to the injection valve via a reducing agent passage. The anomaly detection device comprises a acquisition section that detects the rotational speed of the pump in an injection state of the injection valve as an injection time speed; and a determination device that determines the presence or absence of an anomaly in the injection valve based on the injection time speed.

[0012] When the reducing agent is conveyed from the injector to the exhaust line, the pressure in the reducing agent passage decreases. As the pressure in the reducing agent passage decreases, the pump speed increases to compensate for the amount of reducing agent injected by the injector. Therefore, since there is a relationship between the injector pressure and the change in pump speed, it is possible to accurately determine injector malfunctions based on the pump speed.

[0013] Since the anomaly detection is performed using a direct relationship between the injection state of the reducing agent and the pump speed, the anomaly detection accuracy based on the above configuration is improved compared to anomaly detection based on a drive signal (for example, a duty signal) to drive the pump.

[0014] The functions, features and advantages of the present disclosure will become more apparent from the following detailed description, which is carried out with reference to the accompanying illustrations, wherein: Fig. 1 is a schematic diagram of an exhaust gas purification system of an engine; Fig. 2 is a transition diagram of a rotational speed during an injection through an injector; Fig. 3 is a flowchart of an anomaly detection process; Fig. 4 is a diagram of a relationship between rotational speed and actual injection quantity by a pump; Fig. 5 is a flowchart of a preparation process; Fig. 6 is a transition diagram of an engine speed at a small injection quantity; Fig. 7 is a transition diagram of an engine speed at a large injection quantity; Fig. 8 is a transition diagram of an integration value of the actual injection amount and an integration value of a requested injection amount; Fig. 9 a transition diagram of a speed is when the injector has an open clamping anomaly; and Fig. 10 a transition diagram of a speed is when the injection valve has a clamping anomaly on complete closure or on a complete closing.

[0015] An exhaust gas purification system 10 with a pump control unit 70 and reference to an anomaly detection device is described with reference to the figures. The exhaust gas purification system 10 cleans NOx in the exhaust gas using a selective reduction catalyst (i.e., an SCR catalyst) and is configured as a urea SCR system. The exhaust gas purification system 10 is applicable to various types of vehicles with a diesel engine 30 as an internal combustion engine. The diesel engine 30 can simply be referred to as the engine 30. The exhaust gas purification system 10 can also be applied to construction machinery, such as cranes, agricultural machinery, such as tractors, and the like.

[0016] As in Fig. As shown in Figure 1, an engine exhaust system of the exhaust aftertreatment system 10 can comprise an exhaust pipe or exhaust line 31, which forms an exhaust passage 31a connected to the engine 30. A diesel particulate filter (DPF) 32 and an selective catalytic reduction (SCR) catalyst 33 are arranged sequentially on the upstream side of the engine exhaust system in the exhaust pipe 31. A urea-water injection valve 50 is located between the DPF 32 and the SCR catalyst 33 in the exhaust pipe 31. This valve injects an aqueous urea solution (i.e., urea water) as a liquid reducing agent into the exhaust passage 31a. The urea-water injection valve 50 can simply be referred to as the injection valve 50. The injector 50 is attached to the exhaust pipe 31, with only a tip part positioned in the line 31 in order to avoid the influence of heat from high-temperature exhaust gases on the injector 50 as much as possible.The exhaust gases can, for example, have temperatures around 600 °C. In the present embodiment, the SCR catalyst 33 can also be referred to as a “NOx cleaning catalyst”.

[0017] The DPF 32 is a particulate filter (PM) that collects PM from the exhaust gas. It incorporates a platinum-based oxidation catalyst and removes hydrocarbons (HC) and carbon monoxide (CO), along with soluble organic compounds (SOF), as PM components. The PM trapped in the DPF 32 are burned off and removed during a post-injection, meaning after the main fuel injection in the engine 30, allowing the DPF 32 to be used continuously.

[0018] The SCR catalyst 33 promotes the reduction reaction of NOx (for example, an exhaust gas purification reaction), as 4NO + 4NH3 + O2 - 4N2 + 6H2O (Equation 1) 6NO2 + 8NH3 → 7N2 + 12H2O (Equation 2) NO + NO2 + 2NH3 → 2N2 + 3H2O (Equation 3) for the purification of NOx in the exhaust gas. The injection valve 50 provided on the upstream side of the SCR catalyst 33 corresponds to a device for injecting urea water to generate ammonia (NH3), which serves as a reducing agent for NOx in these reactions.

[0019] An oxidation catalyst can be provided as an ammonia removal device on the downstream side of the SCR catalyst 33 in the exhaust pipe 31. The oxidation catalyst can remove excess ammonia (NH3) from the SCR catalyst.

[0020] The configuration and components of a reducing agent injection system 20, which injects urea solution via the injection valve 50 into the exhaust gas purification system 10, are described below. In the following description, the urea solution is routed from a urea solution tank 40 to the injection valve 50. The urea solution tank 40 can simply be referred to as tank 40. The following description assumes that tank 40 is located upstream of the exhaust gas purification system 10 and that the injection valve 50 is located downstream of the exhaust gas purification system 10.

[0021] As in Fig. As shown in Figure 1, tank 40 is a sealed container with a liquid feed cap, and a urea solution with a predetermined specific concentration is stored in tank 40. In the present embodiment, the urea concentration is 32.5%, which corresponds to a concentration level with the lowest freezing point. At a urea concentration of 32.5%, the urea solution freezes at temperatures around -11°C or lower.

[0022] Tank 40 and injection valve 50 are connected by a supply line 42. An end section on the upstream side of the supply line 42 is connected to a bottom surface of tank 40 to allow the urea solution stored in tank 40 to flow into the supply line 42. In the present embodiment, the supply line 42 can also be referred to as a "reducing agent passage".

[0023] The central part of the supply line 42 includes a urea water pump 44. The urea water pump 44 can also simply be referred to as pump 44. Pump 44 is an electric pump that is driven by an electric current supplied by the pump control unit 70. Pump 44 compresses the urea water and delivers it via the supply line 42 to the injection valve 50.

[0024] Pump 44 has a gear 45 and supplies the urea solution based on the rotational speed of the gear 45. Pump 44 is specifically set to deliver a constant amount of urea solution per revolution of the gear 45. Furthermore, pump 44 is capable of rotating the gear 45 in both forward and reverse directions. Hereinafter, the forward rotation of the gear 45 is referred to as the forward rotation of pump 44, and the reverse rotation of the gear 45 is referred to as the reverse rotation of pump 44. The urea solution in tank 40 is drawn from tank 40 and conveyed downstream by the forward rotation of pump 44, and the reverse rotation of pump 44 returns the urea solution to tank 40.

[0025] The pump 44 is equipped with a rotation sensor 46. The rotation sensor 46 detects a rotational speed N, which corresponds to the number of revolutions or rotational speed ΣN of the pump 44 per unit of time. The rotation sensor 46 detects, for example, the urea water discharge rate through the pump 44. The urea water discharge rate can also be referred to as the pressure delivery rate.

[0026] The supply line 42 includes a pressure sensor 48 on the downstream side of the pump 44. The pressure sensor 48 detects a pressure P in the supply line 42 and, for example, detects a discharge pressure of the urea water through the pump 44.

[0027] The injection valve 50 is connected to a downstream end section of the supply line 42. The injection valve 50 has essentially the same configuration as an existing fuel injection valve (i.e., an injector).

[0028] The injection valve 50 is configured as an electromagnetic on / off valve with a drive part consisting of an electromagnetic solenoid and a valve body part with a needle 52 for opening and closing an injection port at a front end. The injection valve 50 is actuated to open and close in response to a drive signal Sm supplied by the pump control unit 70. That is, when the electromagnetic solenoid is energized in response to the drive signal Sm, the needle 52 moves in the opening direction based on the energization, and the injection port at the front end is opened by the movement of the needle 52 to inject the urea solution.

[0029] The supply line 42 includes a branch line 54. The branch line 54 connects the tank 40 to the supply line 42 at a branch section B on the downstream side of the pump 44. The pressure sensor 48 is provided at a section of the supply line 42 between the pump 44 and the branch section B.

[0030] One end of the branch line 54 is connected to the bottom of the tank 40. A shut-off valve 60 is located at the end of the branch line 54 that is connected to the tank 40. The shut-off valve 60 is closed when the pressure P in the branch line 54 is lower than a predetermined pressure, to prevent the urea solution stored in the tank 40 from flowing into the branch line 54. The shut-off valve 60 opens when the pressure P in the branch line 54 is higher than the predetermined pressure, allowing the urea solution in the branch line 54 to flow into the tank 40.

[0031] Tank 40 includes a heating element 62. The heating element 62 is, for example, an electric heater, and it thaws the frozen urea solution in tank 40 when the heating element 62 is energized based on a command signal from the pump control unit 70. The heating element 62 can be positioned anywhere in, on, or around tank 40 to thaw the frozen urea solution. For example, the heating element 62 can be located near a suction port or opening of the feed line 42.

[0032] A heating element 64 is provided on the outer circumference of the supply line 42. The heating element 64 is, for example, an electric heater, and this thaws the urea water frozen in the supply line 42 when the heating element 64 is energized based on a command signal from the pump control unit 70.

[0033] A temperature sensor 66 is located inside tank 40. The temperature sensor 66 is, for example, a temperature-sensitive diode or a thermistor and measures the temperature of the urea solution in tank 40. An ambient air temperature sensor 68 is located outside tank 40. The ambient air temperature sensor 68 is, for example, a temperature-sensitive diode or a thermistor, and is positioned at a specific distance from tank 40. The ambient air temperature sensor 68 measures the ambient air temperature around the vehicle.

[0034] The pump control unit 70 includes an ECU (electronic control unit) (not shown) which controls an exhaust gas purification process. The ECU includes, for example, a microcomputer with a CPU, ROM, RAM, and an input / output (I / O) interface (all not shown). The pump control unit 70 can obtain the rotational speed N of the pump 44 from the rotation sensor 46, the pressure P in the supply line 42 from the pressure sensor 48, the temperature of the urea solution in the tank 40 from the temperature sensor 66, and the ambient air temperature from the ambient air temperature sensor 68. The pump control unit 70 can control the components of the reducing agent injection system 20 based on these values.The pump control unit 70, in particular the control unit 70 ECU, can be configured to execute a program / instruction set stored in memory to perform a process or series of processes, for example those in the . Fig. 3 and Fig. 5 processes shown and described in more detail below. The microcomputer of the ECU of the control unit 70 can, in particular, be configured to execute a program / instruction set stored in the memory (e.g., RAM, ROM) of the ECU or the microcomputer itself in order to carry out a process or a series of processes, for example, those described in the Fig. 3 and Fig. The 5 processes shown. The microcomputer's memory corresponds to an example of a non-volatile, substantial storage medium.

[0035] When the pump 44 rotates in the forward direction, the pump control unit 70 performs pressure feedback control of the pump 44 (i.e., PI control) to control the pressure P measured by the pressure sensor 48 to match a predetermined reference pressure Po.

[0036] When pump 44 rotates in a forward direction, the pump control unit 70 calculates based on the current load and speed (see Fig. 2) The engine 30 determines a required injection quantity Qo for the injection valve 50. The pump control unit 70 generates a drive signal Sm to realize the calculated required injection quantity Qo and outputs the drive signal Sm to the injection valve 50. In this way, the pump control unit 70 controls the injection quantity Q of the injection valve 50.

[0037] Fig. Figure 2 shows the transition of the rotational speed N during injection through the injector 50. Part (a) of Fig. Figure 2 shows the transition value of the drive signal Sm, part (b) of Fig. 2 shows the transition of rotational speed N, and part (c) of Fig. Figure 2 shows the transition of the pressure P in the supply line 42. Fig. 2. Pulsations or fluctuations that occur at times other than during injection by injector 50 were removed from the transitions between engine speed N and pressure P. Fluctuations that occur at times other than during injection were also removed from the transitions between engine speed N and pressure P in the Fig. 6, Fig. 7, Fig. 9 and Fig. 10 away.

[0038] As in Fig. As shown in Figure 2, the drive signal Sm corresponds to a signal with two values: an ON voltage and an OFF voltage. When the drive signal Sm corresponds to an OFF voltage, the injection valve 50 is closed and the injection of the urea solution through the injection valve 50 is stopped. The duration for which the drive signal Sm corresponds to the OFF voltage is referred to as the injection stop duration Ts. During the injection stop duration Ts, the rotational speed N is controlled by the pressure feedback control of the pump 44 to a predetermined reference speed No. The excess urea solution is returned to the tank 40 via the branch line 54.

[0039] If, on the other hand, the drive signal Sm corresponds to the AN voltage, the injection valve 50 is open and the urea solution is injected through the injection valve 50. The duration for which the drive signal Sm corresponds to the AN voltage is referred to as the injection duration Tp. During the injection duration Tp, the pressure P in the supply line 42 decreases from the reference pressure Po during injection. To compensate for the pressure decrease during injection, the amount of urea solution delivered by the pump 44 is increased by the pressure feedback (hereinafter referred to as the pump delivery amount), and the rotational speed N increases accordingly. Consequently, the urea solution is drawn from the tank 40 and supplied to the injection valve 50. The amount of change or increase in the rotational speed N from the reference speed No during injection is referred to as ΔN.

[0040] The pump control unit 70 switches the ON voltage and the OFF voltage of the drive signal Sm according to a predetermined cycle. Thus, the injection valve 50 repeatedly performs injection and an injection stop (i.e., a pause in injection) according to a predetermined cycle. In the present embodiment, the cycle of the drive signal Sm is at a frequency of 2 Hz, and the injection stop duration Ts and the injection duration Tp during the cycle are controlled to be equal in duration.

[0041] When the pump 44 rotates in the reverse direction, the pump control unit 70 performs speed feedback control so that the speed N obtained from the rotation sensor 46 matches the predetermined speed.

[0042] In the operation described above, the pump control unit 70 controls a duty cycle Du of the electrical current supplied to the pump 44 during its forward rotation (i.e., the pump duty cycle) in order to control the injection quantity Q of the urea solution supplied to the injection valve 50. If an anomaly in the injection quantity Q occurs due to urea crystallization, the anomaly of the injection valve 50 can therefore be determined from the pump duty cycle Du. The anomaly may correspond to the ingress of foreign matter into the injection valve 50 from the side of the exhaust pipe 31 via the injection orifice of the injection valve.

[0043] However, for the following reasons, accurately determining the anomaly of injector 50 from the pump duty cycle Du can be difficult. In cases where, for example, the speed N of pump 44 varies according to the injection quantity Q, the process of calculating the injection quantity Q from the pump duty cycle Du involves calculating the effective value of the electrical current supplied to pump 44 from the pump duty cycle Du. Then, the speed N is calculated based on the effective value of the electrical current, and the injection quantity Q is calculated based on this speed N. That is, the injection quantity Q is calculated indirectly from the pump duty cycle Du. Therefore, if an error occurs during the calculation of the effective value of the electrical current from the pump duty cycle Du, or if the speed N is calculated from the effective value of the electrical current, it is not possible to accurately determine the anomaly of injector 50.

[0044] To solve the aforementioned problem, the pump control unit 70 of the present embodiment performs an anomaly detection process when the pump 44 rotates in the forward direction. The anomaly detection process corresponds to a process for obtaining the rotational speed N during the injection of the urea solution through the injection valve 50 and for determining the presence or absence of an anomaly in the injection valve 50 based on the obtained rotational speed N. Thus, it is possible to accurately determine the anomaly of the injection valve 50 based on the rotational speed N.

[0045] Fig. Figure 3 shows a flowchart of the anomaly detection process performed in the present embodiment. During operation of the motor 30, the pump control unit 70 repeatedly performs the anomaly detection process at predetermined time intervals.

[0046] When the anomaly detection process is started, the pump control unit 70 at S10 determines whether the motor 30 is in operation.

[0047] In particular, the pump control unit 70 determines whether the vehicle's ignition switch is in an ON state. If the pump control unit 70 receives an affirmative determination at S10, i.e., "YES", the process proceeds to S11.

[0048] At S11, the pump control unit 70 determines whether the anomaly detection process can be carried out. Specifically, the pump control unit 70 determines whether the rotation sensor 46, the pressure sensor 48, and the pressure feedback control are all in their normal states. If the pump control unit 70 receives a negative determination at S11, i.e., "NO," it terminates the anomaly detection process. Conversely, if the determination at S11 is positive, i.e., "YES," the process proceeds to S12.

[0049] At S12, the pump control unit 70 determines whether the drive signal Sm corresponds to the ON voltage. If the pump control unit 70 determines that the drive signal Sm is within the injection stop duration Ts, during which the drive voltage Sm corresponds to the OFF voltage, the pump control unit 70 performs a negative determination at S12, i.e., "NO", and the process proceeds to S14. At S14, the pump control unit 70 reaches the rotational speed N of the pump 44 using the rotation sensor 46.

[0050] As in Fig. As shown in Figure 2, with a normal injector 50, the rotational speed N during the injection stop duration Ts corresponds to the reference rotational speed No. However, the rotational speed N can deviate from the reference rotational speed No. during the injection stop duration Ts because it is influenced by the immediately preceding injection. If the injector 50 injects immediately before the target injection stop duration Ts, the pump control unit 70 reaches the reference rotational speed No. during the injection duration Ts after a predetermined time period Tc has elapsed following the start of the injection stop duration Ts. The rotational speed N reached during the injection stop duration Ts after the predetermined time period Tc has elapsed can be referred to as an injection stop speed or rotational speed Ns.In the present embodiment, the injection stop duration Ts after the predetermined time duration Tc has elapsed from the beginning of the injection stop duration Ts corresponds to an “injection stop state”, and the injection stop speed Ns at this time corresponds to a “non-injection speed”.

[0051] If, however, the pump control unit 70 determines that the drive signal Sm is within the injection duration Tp in which the drive signal Sm corresponds to the AN voltage, the pump control unit 70 receives an affirmative determination at S12, i.e., "YES", and the process proceeds to S16. At S16, the pump control unit 70 determines whether the injection stop speed Ns has already been reached. If the pump control unit 70 receives a negative determination at S16, i.e., "NO", the pump control unit 70 terminates the anomaly detection process. If, however, a positive determination occurs at S16, i.e., "YES", the process proceeds to S17, and the pump control unit 70 obtains the rotational speed N using the rotation sensor 46.In the present embodiment, if the process at S17 is carried out by the pump control unit 70, the pump control unit 70 can be referred to as a “gaining section”, since the pump control unit 70 obtains the rotational speed N using the rotation sensor 46.

[0052] The pump control unit 70 reaches rotational speed N during the injection duration Tp and subsequently during the predetermined time Tc following the injection duration Tp. The time period comprising the injection duration Tp and the subsequent predetermined time period Tc can be referred to as the acquisition time Te. The rotational speed N reached during the acquisition time Te can be referred to as the injection speed Np. In the present embodiment, the acquisition time Te corresponds to an "injection state" and the injection speed Np corresponds to an "injection time rotational speed".

[0053] At S18, the pump control unit 70 calculates the increase ΔN of the rotational speed N, that is, the change ΔN. The pump control unit 70 calculates the increase ΔN of the rotational speed N by subtracting the injection stop speed Ns obtained at S14 from the injection speed Np obtained at S17.

[0054] The pump control unit 70 achieves the injection speed Np for each acquisition time Te, and this in turn achieves the injection stop speed Ns for each injection stop time Ts. In this case, the pump control unit 70 (i) achieves the injection stop speed Ns during the injection stop time Ts before the target acquisition time Te, and (ii) achieves the injection speed Np during the target acquisition time Te. Here, the target acquisition time Te corresponds to the acquisition time Te after the injection stop time Ts in which the injection stop speed Ns is achieved. A preset condition for achieving the injection stop speed Ns can be that the injection stop speed Ns is obtained before the injection speed Np during the subsequent target acquisition time Te.At S18, the pump control unit 70 subtracts the injection stop speed Ns in the injection stop duration Ts before the target acquisition duration Te from the injection speed Np in the target acquisition duration Te, thereby calculating the increase ΔN of the rotational speed N in the target acquisition duration Te.

[0055] At S20, the pump control unit 70 calculates an actual injection quantity Qp from the increase in rotational speed N ΔN achieved at S18. As in Fig. As shown in Figure 4, a correlation diagram illustrates the relationship between the rotational speed ΣN of pump 44 and the actual injection quantity Qp. Such a correlation can be used to create a conversion table, which can be stored in the memory of the pump control unit 70. A conversion table can be a record of the values ​​of the actual injection quantity Qp and their corresponding rotational speeds ΣN, and vice versa. The pump control unit 70 integrates the rate of increase ΔN of rotational speed N obtained at S18 for the duration of the target acquisition time Te to calculate the rotational speed ΣN and uses the conversion table to convert the calculated rotational speed ΣN into the actual injection quantity Qp. After calculating the actual injection quantity Qp, the pump control unit 70 increments a number M by 1 at S21, and the process then proceeds to S22. The number M represents the number of injections, respectively.Frequency with which the actual injection amount Qp was calculated.

[0056] At S22, the pump control unit 70 determines whether the number M is greater than a prescribed number Mo, where Mo is a natural number (i.e., a positive integer) equal to or greater than two (i.e., Mo ≥ 2). The prescribed number Mo corresponds to the number of acquisition times Te for integrating the actual injection quantity Qp to correctly determine the anomaly of the injection valve 50, which in the present embodiment is set to "100". If the pump control unit 70 obtains a negative determination at S22, i.e., "NO", the pump control unit 70 terminates the anomaly determination process. If, on the other hand, the pump control unit 70 obtains an affirmative determination at S22, i.e., "YES", the process proceeds to S24.

[0057] At S24, the pump control unit 70 calculates an integrated actual injection quantity ΣQp by integrating the actual injection quantity Qp in the M parts of the acquisition time Te, and calculates an integrated required injection quantity ΣQo by integrating the required injection quantity Qo in the M parts of the acquisition time Te (that is, the injection time Tp). Subsequently, at S26, the pump control unit 70 calculates a consumption quantity deviation Dc, as shown in Equation 4, which is an absolute value of the difference between the integrated actual injection quantity ΣQp and the integrated required injection quantity ΣQo. |∑Qp−∑Qo|=Dc

[0058] At S28, the pump control unit 70 determines whether the consumption amount deviation Dc is greater than a predetermined differential threshold Dt. The differential threshold Dt corresponds to a threshold for determining whether an unexpected change has occurred in the injector 50. Here, the unexpected change in the injector 50 can be a change other than an expected change due to the aging of the injector 50, that is, a non-aging-related change. The differential threshold Dt is set to half of the integrated actual injection amount ΣQp, which is calculated at S24. If the pump control unit obtains a negative determination at S28, that is, "NO", the pump control unit 70 determines at S30 that the injector 50 is normal, and the process proceeds to S31.

[0059] At S31, the pump control unit 70 sets the value M to zero, and at S32, the pump control unit 70 updates the injection stop speed Ns, which is used in the determination at S28. That is, the pump control unit 70 updates the injection stop speed Ns, which is used to calculate the increase ΔN of the rotational speed N at S18, as a speed threshold value Nt. After the pump control unit 70 performs the update of the injection stop speed Ns at S32, the anomaly determination process ends. When the pump control unit 70 performs the process at S28 in the present embodiment, the pump control unit 70 can be referred to as a "determination device" because the pump control unit 70 performs a determination process.If the pump control unit 70 performs the process at S32, the pump control unit 70 can be referred to as an "updater" because it performs an update process. The updater can be part of the acquisition section. That is, the acquisition section can include the updater.

[0060] If, on the other hand, the pump control unit 70 receives a positive determination at S28, that is, "YES", the pump control unit 70 determines that the injector 50 is abnormal, and this determines the type of anomaly at S34, S36, S38, S40, and S42. If the consumption amount deviation Dc is greater than the difference threshold Dt, an anomaly can occur in which the actual injection amount Qp is significantly larger than the required injection amount Qo, or in which the actual injection amount Qp is significantly smaller than the required injection amount Qo.

[0061] If the actual injection quantity Qp is significantly greater than the required injection quantity Qo, an excess of urea solution relative to the amount of NOx in the exhaust gas is injected into exhaust gas passage 31a. In other words, more urea solution is injected into exhaust gas passage 31a than is required to clean the NOx in the exhaust gas. Consequently, a urea precipitate can form from the excess urea solution in exhaust gas passage 31a and collect in the outlet line 31.

[0062] If the actual injection quantity Qp is significantly smaller than the required injection quantity Qo, the amount of urea solution injected into exhaust port 31a is less than the corresponding amount of NOx in the exhaust gas. In other words, less urea solution is injected into exhaust port 31a than is required to clean the NOx in the exhaust gas. Therefore, it is possible that the NOx in the exhaust gas is not sufficiently cleaned. In the present embodiment, anomalies such as over-injection (i.e., excess) and under-injection (i.e., deficiency) of urea solution can be determined using the injection stop-speed Ns.

[0063] In particular, if the pump control unit obtains a positive determination at S28, the pump control unit 70 sets the value M to zero at S33 and proceeds to S34. At S34, the pump control unit 70 determines whether the integrated actual injection quantity ΣQp is less than an injection threshold value Qt. The injection threshold value Qt corresponds to an injection quantity according to a maximum injection quantity Qmax of the injector 50, which is more precisely set by integrating the maximum injection quantity Qmax of each acquisition time Te to an integrated injection quantity. If the pump control unit 70 obtains a negative determination at S34, the pump control unit 70 determines at S36 that a consumption quantity anomaly has occurred at the injector 50 and terminates the anomaly determination process.Here, the consumption amount anomaly corresponds to an anomaly in which the actual injection amount Qp is greater than the maximum injection amount Qmax.

[0064] If the pump control unit 70 receives an affirmative determination at S34, it determines at S38 whether the injection stop speed Ns is less than or equal to the speed threshold Nt. The speed threshold Nt corresponds to a threshold for determining the type of anomaly of the injector 50 based on the injection stop speed Ns. Specifically, the speed threshold Nt corresponds to an injection stop speed Ns obtained in the previous anomaly determination process, and this is updated as the speed threshold Nt (i.e., at S32). If the pump control unit 70 receives a negative determination at S38, i.e., "NO," it determines at S40 that an open-jaw or open-jaw jamming anomaly has occurred in the injector 50 and terminates the anomaly determination process.An open-jaw anomaly corresponds to an anomaly in which the injector 50 is stuck or jammed in the open state (for example, remains in this position) and cannot close due to this anomaly. In the case of an open-jaw anomaly, the actual injection quantity Qp is significantly larger than the required injection quantity Qo.

[0065] If the pump control unit 70 receives a positive reading at S38, i.e., "YES", the pump control unit 70 determines at S42 that a jamming anomaly has occurred at the fully closed injection valve 50 and terminates the anomaly detection process. Here, the jamming anomaly at fully closed corresponds to an anomaly in which the injection valve 50 is stuck or jammed in a fully closed state (for example, remains in this position) and the injection valve 50 does not open. In the case of the jamming anomaly at fully closed, the actual injection quantity Qp is significantly smaller than the required injection quantity Qo.

[0066] If the pump control unit 70 receives a negative determination at S10, i.e., "NO", the process proceeds to S44. At S44, the pump control unit 70 performs a preparatory process to handle an anomaly in an unattended vehicle after the operation of the engine 30 has been stopped.

[0067] Fig. 5 is a flowchart of the preparation process at S44 in Fig. 3. After the preparation process begins, the pump control unit 70 at S50 performs a suction process. During this process, the pump control unit 70 rotates the pump 44 in reverse to draw the urea solution in the feed line 42 back into the tank 40. The suction process at S50 can prevent situations where urea solution remains in the feed line 42 while the vehicle is left unattended by draining the urea solution from the feed line 42 back into the tank 40. "Unattended" can refer to situations where the vehicle engine 30 is switched off and the driver leaves the vehicle with the engine off. Thus, the suction process at S50 can help limit and / or prevent situations where the feed line 42 freezes and bursts due to the freezing of the urea solution within it.

[0068] At S52, the pump control unit 70 determines whether the speed threshold value Nt has been updated during the operation of the motor 30. If the pump control unit 70 receives a negative determination at S52, i.e., "NO", the pump control unit 70 terminates the operation. Fig. 5 preparation process shown and the one in Fig. 3 anomaly detection process shown. If, on the other hand, the pump control unit 70 receives an affirmative determination at S52, that is, "YES", the pump control unit 70 proceeds to S54. An affirmative determination at S52 means that the speed threshold Nt was updated during the last operation of the motor 30 before the motor 30 was shut down. That is, the motor 30 is restarted after an update of the speed threshold Nt due to a normality determination at S30. Fig. 3 switched off.

[0069] At S54, the pump control unit 70 stores the speed threshold value Nt in memory (for example, a substantial non-volatile memory device such as RAM) and terminates the operation. Fig. 5 preparation process shown and the one in Fig. 3 anomaly detection process shown. Consequently, the speed threshold value Nt is stored during the time the engine is switched off (i.e., stopped) until the next start of the engine 30 (i.e., when the operation of the engine 30 is resumed). In the present embodiment, when the pump control unit 70 performs the process at S54, it can be described as a "retention device" because the pump control unit 70 holds the speed threshold value Nt in memory until the vehicle engine 30 is restarted.

[0070] An example of the anomaly detection process will then be presented with reference to the Fig. 6, Fig. 7, Fig. 8, Fig. 9 and Fig. 10 described. Fig. Figure 6 shows a transition in rotational speed N when the injection quantity Q is small. Fig. Figure 7 shows a transition in rotational speed N when the injection quantity Q is large.

[0071] In the two Fig. 6 and Fig. Figure 7 shows (a) a transition value of the drive signal Sm, (b) a transition of the rotational speed N and (c) a transition of the pressure P in the supply line 42.

[0072] When the urea water is injected through the injection valve 50 during the injection time Tp of the drive signal Sm, the pressure P in the supply line 42 decreases.

[0073] To compensate for the pressure drop during injection, the pump output is increased by pressure feedback, and the rotational speed N increases accordingly. As in Fig. As shown in Figure 6, with a short injection duration Tp and a small actual injection quantity Qp of the injector 50, the decrease in pressure P is small, and the increase in rotational speed N ΔN is also small. On the other hand, as shown in Fig. As shown in Figure 7, with a long injection duration Tp and a large actual injection quantity Qp of the injector 50, the decrease in pressure P is large and the increase in rotational speed N ΔN is also large. That is, there is a correlation between the actual injection quantity Qp of urea solution by the injector 50 and the increase in rotational speed N ΔN. Consequently, the actual injection quantity Qp can be calculated from the increase in rotational speed N ΔN. As shown in the Fig. 6 and Fig. As shown in Figure 7, the predetermined time duration Tc, during which the increase in rotational speed N ΔN is achieved, is set such that it increases proportionally to the injection duration Tp. That is, if the injection duration Tp becomes longer, the predetermined duration Tc also becomes longer.

[0074] Fig. Figure 8 shows the transition between the integration value of the actual injection quantity Qp and the integration value of the required injection quantity Qo. In an initial state before an expected change due to the aging of the injector 50, the actual injection quantity Qp is essentially equal to the required injection quantity Qo. However, when the aging of the injector 50 begins (that is, over time), a significant difference arises between the actual injection quantity Qp and the required injection quantity Qo. Thus, the consumption quantity deviation Dc is caused by the integration value of the actual injection quantity Qp and the integration value of the required injection quantity Qo. As shown in Figure 8, the actual injection quantity Qp is the gradual change in the fuel consumption. Fig. If the actual injection amount Qp is shown as a continuous line in Figure 8, the consumption amount deviation Dc at a time tm according to the number M is less than the difference threshold Dt if there is no anomaly in the injector 50.

[0075] On the other hand, in the event of an anomaly of injector 50 (for example, a defect, a malfunction), as described in Fig. The actual injection quantity Qp, shown as a dashed line in Figure 8, indicates that the consumption quantity deviation Dc at time tm is greater than the difference threshold Dt. Thus, the presence or absence of an anomaly in the injector 50 can be determined based on the actual injection quantity Qp.

[0076] Fig. Figure 9 shows the transition of the rotational speed N for an injector 50 with an open clamping anomaly. Fig. Figure 10 shows the transition of the rotational speed N for an injector 50 with a clamping anomaly at full closure. In the Fig. 9 and Fig. Figure 10 shows (a) the transition value of the drive signal Sm, (b) the transition of the rotational speed N and (c) the transition of the pressure P in the supply line 42.

[0077] As in Fig. As shown in Figure 9, the injection stop speed Ns becomes the reference speed Nr when the clamping anomaly occurs at full closure at injector 50, since injector 50 is closed for the injection stop duration Ts. Conversely, injector 50 is not closed for the injection stop duration Ts when the open clamping anomaly occurs at injector 50, as shown in Figure 9. Fig. Figure 10 shows that, due to the constant injection of urea solution by the injection valve 50, the injection stop velocity Ns increases to a value higher than the reference velocity No in order to maintain the pressure P of the supply line 42. This means that the injection stop velocity Ns varies depending on the type of anomaly caused in the injection valve 50. Therefore, it is possible to determine the type of anomaly caused in the injection valve 50 based on the injection stop velocity Ns.

[0078] The following effects can be achieved by the present embodiment.

[0079] As described above, there is a relationship between the injection state of the urea solution by the injection valve 50 and the change in rotational speed N. Therefore, in the present embodiment, it is possible to correctly determine the anomaly of the injection valve 50 by determining it based on the rotational speed N.

[0080] In particular, in the present embodiment, since there is a correlation between (i) the actual injection quantity Qp of the injection valve 50, which indicates the injection state of the urea solution through the injection valve 50, and (ii) the increase ΔN of the rotational speed N, which indicates the change in rotational speed N, specific anomalies of the injection valve 50 can be determined based on the injection speed Np and the injection stop speed Ns. Therefore, it is possible to accurately determine the anomaly of the injection valve 50 by eliminating the influence of the injection stop speed Ns, compared to anomaly determinations where the anomaly of the injection valve 50 is determined solely by the injection speed Np.

[0081] In practical terms, the increase in rotational speed N ΔN is calculated from the injection velocity Np and the injection stop velocity Ns, and the actual injection quantity Qp of injector 50 is then calculated from the direct relationship between the increase in rotational speed N ΔN and the actual injection quantity Qp of injector 50. Since the difference between the actual injection quantity Qp and the required injection quantity Qo correlates with the anomaly of injector 50, it is possible to determine the anomaly of injector 50 based on the actual injection quantity Qp.

[0082] In the present embodiment, the presence or absence of an anomaly in the injection valve 50 is determined using a direct relationship between the injection state of urea water by the injection valve 50 and the rotational speed N. Therefore, it is possible to improve the accuracy of the anomaly determination compared to cases where the anomaly of the injection valve 50 is determined using the indirect relationship between the pump duty cycle Du and the rotational speed N.

[0083] In the present embodiment, since an anomaly in the injector 50 can be determined more precisely and a specific anomaly of the injector 50 can be identified, a vehicle user can be informed of the anomaly (for example, via a warning light, an audible warning, or an indication of the anomaly on a vehicle display) in order to facilitate and initiate precise repair of the exhaust aftertreatment system 10. This makes it possible to prevent and / or restrict the use of the vehicle in a condition in which the exhaust aftertreatment system 10 is defective (for example, exhibits an anomaly, defect, or malfunction) and the exhaust gas is not being cleaned.

[0084] In the present embodiment, when calculating the increase ΔN of the rotational speed N of the target duration Te, the increase ΔN is calculated using the injection stop speed Ns achieved during the injection stop duration Ts immediately before the target duration Te. The aging-related change of the injector 50 is reflected in the injection stop speed Ns achieved during the immediately preceding injection stop duration Ts. Therefore, it is possible to accurately determine the anomaly of the injector 50 in a state that reflects the aging of the injector 50.

[0085] In the present embodiment, the type of anomaly in the injection valve 50 is determined based on the injection stop speed Ns. The injection stop speed Ns varies depending on the type of anomaly occurring in the injection valve 50, such as a jamming anomaly during complete closure or an open jamming anomaly. Therefore, it is possible to correctly determine the type of anomaly in the injection valve 50 based on the injection stop speed Ns.

[0086] In the present embodiment, if the consumption amount deviation Dc, based on the difference between the required injection amount Qo and the actual injection amount Qp, is less than the difference threshold Dt, the injection stop speed Ns, which is used to calculate the actual injection amount Qp, is set as the speed threshold Nt.

[0087] Since the injection stop speed Ns varies with the injection stop duration Ts as injector 50 ages, the speed threshold Nt is also updated for comparison with the injection stop speed Ns. If the speed threshold Nt is updated to an abnormal value, it is difficult to correctly determine the type of anomaly in injector 50 based solely on the speed threshold Nt.

[0088] In the present embodiment, if the consumption amount deviation Dc is less than the difference threshold Dt, the pump control unit 70 determines that the injection valve 50 is normal. Therefore, the injection stop speed Ns, used to calculate the actual injection amount Qp of the injection valve 50 determined to be normal, is also considered normal.

[0089] Therefore, by updating the injection stop speed Ns as the speed threshold Nt, it is possible to update the speed threshold Nt appropriately.

[0090] In the present embodiment, if the operation of the motor 30 is stopped after the speed threshold Nt has been updated, the speed threshold Nt is stored unchanged in memory during the stop time.

[0091] An anomaly in injector 50 may occur during the stop period. If, in such a case, the speed threshold Nt is set after the next engine start 30, the speed threshold Nt may be set to an abnormal value due to the anomaly in injector 50. In such a case, it is not possible to correctly determine the type of anomaly in injector 50 based on the speed threshold Nt.

[0092] In the present embodiment, if the operation of the engine 30 is stopped after the speed threshold value Nt has been updated, the speed threshold value Nt remains unchanged over the stop period. Since the speed threshold value Nt has been updated, it is evaluated, assuming here that the unchanged speed threshold value Nt is normal. Therefore, even if an anomaly occurs in the injection valve 50 during the stop period, it is possible to appropriately determine the nature of the anomaly after its occurrence based on the speed threshold value Nt, which was determined to be normal before the anomaly occurred.

[0093] In the present embodiment, an anomaly of the injection valve 50 is determined using the integrated actual injection amount ΣQp, which is obtained by integrating the actual injection amount Qp in the M parts / times in the acquisition time duration Te.

[0094] The rate of increase ΔN of rotational speed N is smaller than the reference speed No. In particular, the rate of increase ΔN is approximately 20 to 30 rpm, while the reference speed No is approximately 1200 rpm. If the actual injection quantity Qp is only used for a given acquisition time Te, then determining an anomaly in injector 50 based on data (e.g., Qp) from only one time period Te cannot be correct.

[0095] In the present disclosure, the anomaly of the injector 50 is determined using the integrated actual injection quantity ΣQp, which is obtained by integrating the actual injection quantity Qp in the M parts / times during the acquisition time Te. In this way, the anomaly determination of the injector 50 in the present embodiment can be carried out more accurately and correctly than an anomaly determination in which the anomaly of the injector 50 is determined using the actual injection quantity Qp over an acquisition time Te.

[0096] The present disclosure is not limited to the description of the foregoing embodiment and may be modified as follows.

[0097] The anomaly detection process involves determining the type of anomaly (that is, S34 - S42 in Fig. 3) not necessarily carried out. The type of anomaly to be determined is not limited to, for example, an open-jaw anomaly and a jamming anomaly when completely closed, and it is not necessary to determine an anomaly in the consumption amount.

[0098] An example has been shown in which the injection stop speed Ns is reached during each injection stop duration Ts. However, the frequency of reaching the injection stop speed Ns is not limited to each injection stop duration Ts. For example, the injection stop speed Ns can be reached only once during the operation of engine 30, before the injection of urea solution by injector 50 is initiated. Thus, the preset condition for reaching the injection stop speed can be such that the injection stop speed is reached once after starting engine 30, but before the injection of urea solution by injector 50.

[0099] Furthermore, the injection stop speed Ns is not necessarily detected during the operation of engine 30. For example, if the speed threshold Nt, which was updated during the previous operation of engine 30, is retained (that is, S54 in Fig. 5) Such a speed threshold Nt can be used as the injection stop speed Ns during the running operation of the engine 30. In such a case, it may not be possible to determine the type of anomaly using the injection stop speed Ns.

[0100] The anomaly detection process requires the integration of the actual injection amount Qp (that is, S24 in Fig.3) does not necessarily have to be carried out. In this case, the absolute value of the difference between the actual injection quantity Qp and the required injection quantity Qo corresponds to the consumption quantity deviation Dc. Furthermore, it is possible to increase or decrease the number of integration times for integrating the actual injection quantity Qp.

[0101] Although an example is shown using the injection quantity Q in calculating the consumption quantity deviation Dc, the rotational speed ΣN can also be used in such a calculation. In particular, a required rotational speed ΣNo of the injector 50 is calculated based on the current load and the rotational speed of the engine 30, and the consumption quantity deviation Dc can be calculated from an absolute value of the difference between the actual rotational speed ΣNp, calculated from the increase in rotational speed ΔN of the rotational speed N, and the actual rotational speed ΣNo.

Claims

[1] Anomaly detection device for use in an exhaust gas purification system, which is arranged in an exhaust gas passage (31a) of an internal combustion engine (30) and comprises (a) an injection valve (50) for injecting a liquid reducing agent towards a NOx purification catalyst which purifies NOx in an exhaust gas, and (b) a pump (44) for compressing and supplying the reducing agent towards the injection valve via a reducing agent passage (42), wherein the anomaly detection device has: a acquisition section (S17) which obtains a pump speed in an injection state of the injector as an injection time speed (Np); and a determining device (S28) which determines, based on the injection time rotational speed (Np), whether the injection valve has an anomaly, wherein The determining device determines whether the injector has an anomaly based on a difference between (i) a required injection amount (Qo) of the injector and (ii) an actual injection amount (Qp) calculated from the injection time speed; The acquisition section obtains a pump speed in an injection-stop state of the injector, in which a drive signal (Sm) supplied to the injector (50) for opening and closing the injector (50) corresponds to an OFF voltage for closing the injector (50), as a non-injection-time speed (Ns) (S14), wherein a duration in which the drive signal (Sm) corresponds to the OFF voltage is an injection-stop duration (Ts), and the acquisition section obtains the pump speed in the injection-stop state of the injector (50) after the elapsed time (Tc) following the start of the injection-stop duration (Ts), if the injector (50) injects immediately before the injection-stop duration (Ts), and the predetermined duration (Tc) is set such that it is proportional to an injection duration (TP) with respect to the duration increases; the determining device calculates the actual injection amount from an increase (ΔN) of the injection time speed relative to the non-injection time speed (S20); the determining device, when the determining device determines that the injector has an anomaly, compares the non-injection time speed with a preset speed threshold (Nt) (S38); The determining device determines that the injector has an open-jaw anomaly that prevents the injector from closing when the non-injection-time speed is greater than the threshold (S40); and The determining device determines that the injector has a clamping anomaly when fully closed, in which the injector remains closed when the non-injection time speed is lower than or equal to the threshold (S42). [2] Anomaly detection device according to claim 1, wherein the injector repeatedly performs an injection and a stop of the injection in a preset cycle, The acquisition phase is when the injection-time speed is reached after the injection valve has started, while the non-injection-time speed is reached before the injection valve has started, and The determining device calculates the actual injection amount from the increase in (i) the injection time speed after the start of injection by the injector relative to (ii) the non-injection time speed before the start of injection by the injector. [3] Anomaly detection device according to claim 1 or 2, wherein The acquisition section repeatedly captures the non-injection-time speed according to a preset condition, and the acquisition section includes an updater (S32) which updates the speed threshold by the non-injection time rotational speed used when determining by the determining device that the injector does not have an anomaly. [4] Anomaly detection device according to claim 3, further comprising: a retention device (S54) which maintains the speed threshold value over a stop duration of the internal combustion engine, extending from a stop of the internal combustion engine to a subsequent start of the same, if operation of the internal combustion engine is stopped after the speed threshold value has been updated. [5] Anomaly detection device according to any one of claims 1 to 4, wherein The injector repeatedly performs an injection and a stop of the injection, and the determining device determines whether the injector has an anomaly based on a difference between (i) an integration value (ΣQp) of the required injection amount from each of a plurality of injection states and (ii) an integration value (ΣQo) of the actual injection amount from each of the plurality of injection states.

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