Control device and notification method

Abstract

An embodiment of the present application is a control device having a notification section that, in an exhaust gas aftertreatment device that includes a filter that collects particulate matter in exhaust gas of an engine and an oxidation catalyst provided upstream of the filter, regenerates the filter using the action of the oxidation catalyst, in a case where forced regeneration that forcibly raises the temperature of the exhaust gas is performed, when the number of times that it is estimated that the temperature of the exhaust gas is below a light-off temperature for a predetermined time or more exceeds a predetermined threshold value, the notification section notifies of a message that there is a problem with the operating state of the engine.

Description

TECHNICAL FIELD

[0001] The present application relates to a control device and a notification method.

[0002] This application claims priority based on Japanese Patent Application No. 2021-034111 filed on March 4, 2021, the contents of which are incorporated herein. BACKGROUND

[0003] As described in Patent Literature 1, in an exhaust purification device of a diesel engine, when the exhaust temperature is maintained at or above the light-off temperature (activation temperature) of the catalyst of the filter for a predetermined time (for example, several minutes), the collected particulate matter is combusted, and the filter is regenerated (self-regeneration), but when the exhaust temperature does not reach the activation temperature or when the temperature drops before the regeneration is completed even if the activation temperature is reached, the particulate matter accumulates in the filter. As a filter regeneration method for avoiding such a situation, forced regeneration for removing the particulate matter by forcibly raising the exhaust temperature is sometimes performed. In the forced regeneration, automatic regeneration in which regeneration is automatically performed when a certain condition is satisfied and manual regeneration in which regeneration is performed at an arbitrary timing by the operation of the driver are included. However, in a working machine, even if forced regeneration can be performed by automatic or manual, since the frequency of engine stop is high, and the variation of engine speed corresponding to the work content and work load is large, although forced regeneration can be performed, the tendency of particulate matter accumulation is strong.

[0004] Here, the working machine described in Patent Literature 1 is a working machine equipped with an exhaust purification device that collects particulate matter in the exhaust of a diesel engine using a filter and regenerates the filter by combusting the collected particulate matter, and has, for example, a regeneration determination mechanism that determines that the forced regeneration has failed when the exhaust temperature reaches below a threshold value indicating that regeneration is possible during forced regeneration of the filter, and a notification mechanism that notifies a message indicating that the forced regeneration has failed when the number of times that the forced regeneration has failed determined by the regeneration determination mechanism reaches a predetermined threshold value or more. In the working machine described in Patent Literature 1, for example, in the case where automatic regeneration of the filter has failed a predetermined number of times, warning information that notifies a message indicating that the forced regeneration has failed, the number of times of regeneration failure, and the reason for the regeneration failure such as a decrease in the exhaust temperature are notified. Also, according to the working machine described in Patent Literature 1, in the case where regeneration failure frequently occurs due to the use pattern of the working machine or the like, the message indicating that the regeneration failure has occurred can be prevented from being frequently notified.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2010-203297 SUMMARY

[0008] The problem that the invention aims to solve

[0009] In the working machine described in Patent Document 1, although it is possible to inform the reasons for regeneration failure, such as the drop in exhaust temperature after regeneration failure, there are problems such as the inability to inform the operating status during forced regeneration when regeneration has not failed or when regeneration fails for other reasons.

[0010] The present invention was made in view of the above circumstances, and its object is to provide a control device and notification method capable of notifying the user of problems such as the operating status during forced regeneration.

[0011] Methods for solving problems

[0012] To address the aforementioned issues, one embodiment of the present invention provides a control device comprising a regeneration state determination unit. In an exhaust aftertreatment device comprising a filter for collecting particulate matter from engine exhaust, an oxidation catalyst disposed upstream of the filter, and an exhaust aftertreatment device that regenerates the filter using the action of the oxidation catalyst, when forced regeneration is performed to forcibly raise the temperature of the exhaust, the regeneration state determination unit notifies the engine of a problem in its operating state when the number of times the exhaust temperature is estimated to be below the ignition temperature for a predetermined period of time exceeds a predetermined threshold.

[0013] Furthermore, in one embodiment of the present invention, a notification method includes the following steps: in an exhaust aftertreatment device comprising a filter for collecting particulate matter in engine exhaust and an oxidation catalyst disposed upstream of the filter, and regenerating the filter using the action of the oxidation catalyst, when forced regeneration that forces a forced increase in the temperature of the exhaust is performed, the notification message is sent when the number of times the estimated temperature of the exhaust is below the ignition temperature for a predetermined time exceeds a predetermined threshold.

[0014] Invention Effects

[0015] According to various embodiments of the present invention, it is possible to notify of problems such as operational status during forced regeneration. Attached Figure Description

[0016] Figure 1 This is a system diagram illustrating an example configuration of an engine control system according to an embodiment of the present invention.

[0017] Figure 2 It means Figure 1 A block diagram illustrating an example configuration of the control device 100 shown in the figure.

[0018] Figure 3 It is a schematic representation Figure 2A timing chart showing an example of the operation of the control device 100.

[0019] Figure 4 is a schematic view showing Figure 1 A timing chart showing an example of the operation of the engine control system.

[0020] Figure 5 is a view showing Figure 2 A flowchart showing an example of the operation of the regeneration target temperature resetting section 104.

[0021] Figure 6 is a control block diagram showing the regeneration state determination section 105.

[0022] Figure 7 is a view showing Figure 2 A flow showing an example of the operation of the regeneration state determination section 105.

[0023] Figure 8 is a mode diagram for explaining Figure 2 A mode diagram showing an example of the operation of the regeneration state determination section 105.

[0024] Figure 9 is a mode diagram for explaining Figure 2 A mode diagram showing an example of the operation of the regeneration state determination section 105.

[0025] Figure 10 is Figure 2 A flowchart showing an example of the operation of the regeneration state determination section 105. DETAILED DESCRIPTION

[0026] Hereinafter, an embodiment of the present application will be described with reference to the drawings. Note that the same or corresponding components are denoted by the same reference numerals in each drawing, and the description will be appropriately omitted.

[0027] (Engine Control System 10)

[0028] Figure 1 is a system diagram showing an example of the configuration of the engine control system 10 of one example of the exhaust purification system of each embodiment of the present application. Figure 1 The engine control system 10 shown in FIG. 1 includes an engine 1, an exhaust pipe 3, a DPF device 5 as one example of an exhaust aftertreatment device, a display 8, a control device 100, and an HC distributor 7. Note that in Figure 1 In the engine control system 10 (or the control device 100) of the present embodiment, mainly the configuration related to the forced regeneration of the DPF device 5 is shown, and the configuration related to other actions such as fuel injection control is appropriately omitted from the illustration.

[0029] The engine 1 is an example of a constitution of an internal combustion engine, and in the present embodiment, is a multi-cylinder diesel engine. An exhaust pipe 3 passes exhaust gas of the engine 1 through the DPF device 5 and exhausts it to the atmosphere.

[0030] The DPF device 5 is a device that purifies particulate matter (PM) contained in the exhaust gas of the engine 1, and includes a DOC (Diesel Oxidation Catalyst) 51 provided in the exhaust pipe 3 of the engine 1, and a filter DPF (Diesel Particulate Filter) 52 that collects PM in the exhaust gas of the engine 1. The DPF device 5 regenerates the DPF 52 by the action of the DOC 51. The DPF device 5 oxidizes PM collected downstream by nitrogen dioxide converted by the DOC 51 provided upstream of the DPF 52 into carbon dioxide, thereby removing the PM.

[0031] Further, the DPF device 5 includes a DOC inlet temperature sensor 94 that detects the exhaust gas temperature at the inlet of the DOC 51, and a DOC outlet temperature sensor 95 that detects the exhaust gas temperature at the outlet of the DOC 51, and a set of pressure sensors 96, 97 that detect the pressure difference at the inlet and outlet of the DPF 52. The respective detection values of the DOC inlet temperature sensor 94, the DOC outlet temperature sensor 95, and the pressure sensors 96, 97 are output to the control device 100.

[0032] The HC distributor 7 is an exhaust pipe fuel injection device that injects fuel (HC) (hereinafter referred to as HC supply) into the exhaust pipe 3 upstream of the DOC 51. The HC supply distributed by the HC distributor 7 is controlled by the control device 100.

[0033] The display 8 includes, for example, a display panel and an input panel, functions as a display device and an output device, displays predetermined characters, images, and the like according to the instruction of the control device 100, and outputs a signal corresponding to the output operation of the user (operator) to the control device 100.

[0034] The engine control system 10 of the present embodiment performs forced regeneration (DPF regeneration operation) periodically in order to burn PM accumulated in the DPF 52. In the forced regeneration, the temperature of the exhaust gas, the temperature of the DOC 51, and the like are forcibly raised. The forced regeneration is performed by, for example, post injection for mixing fuel into the exhaust gas in the engine 1, or by combining post injection and HC (fuel) supply (injection) by the HC distributor 7 toward the inside of the exhaust pipe 3 upstream of the DPF device 5, and burning HC in the inside of the DOC 51 provided upstream of the DPF 52, and raising the temperature of the DPF 52.

[0035] Note that the engine control system 10 of the present embodiment includes, at the time of forced regeneration (DPF regeneration operation), automatic regeneration that automatically performs regeneration in a normal operation state (a state in which the engine speed is not forcibly fixed, and normal operation and work are performed) when a certain condition is satisfied, and custom manual regeneration (manual regeneration) that performs regeneration at an arbitrary timing according to an operation of the user. The custom manual regeneration is a control in which, in a case where the exhaust temperature does not sufficiently rise in the normal operation state, and the temperature of the DPF device 5 cannot be stably controlled to the target temperature, the normal operation is stopped at the user's permission, and the control of the performance of the DPF device 5 is resumed. In the custom manual regeneration, the control device 100 first prompts the user of a state in which the custom manual regeneration can be performed using the display 8, and further presents a request to perform the custom manual regeneration. In response to this, if the user issues an instruction to perform the custom manual regeneration using the display 8, the control device 100 fixes the engine speed to a certain speed, and raises the exhaust temperature to perform forced regeneration.

[0036] (CONTROL DEVICE 100)

[0037] REFERENCE Figures 2 to 10 , the configuration example and the action example of the control device 100 indicated in Figure 1 will be described. Figure 2 is a block diagram indicating a configuration example of the control device 100 indicated in Figure 1 . Figure 3 is a time chart schematically indicating an action example of the control device 100 indicated in Figure 2 . Figure 4 is a time chart schematically indicating an action example of the engine control system indicated in Figure 1 . Figure 5 is a flowchart indicating an action example of the regeneration target temperature resetting section 104 indicated in Figure 2 . Figure 6 is a control block diagram indicating the regeneration state determination section 105 indicated in 2. Figure 7 is a flow indicating an action example of the regeneration state determination section 105 indicated in Figure 2 . Figures 8 to 9 is a mode diagram for explaining the action example of the regeneration state determination section 105 indicated in Figure 2 .92 Figure 10 is a flowchart indicating an action example of the regeneration state determination section 105 indicated in Figure 2 .

[0038] The control device 100 indicated in Figure 2 can be configured using, for example, a computer such as a microcomputer, a peripheral circuit of the computer, a peripheral device, as a functioning configuration that is configured by combining hardware of the computer and software such as a program executed by the computer, and includes a plurality of modules as indicated in Figure 2 . In the control device 100, the control device 100 is configured by combining the plurality of modules indicated inFigure 2 In the illustrated example, the control device 100 includes a fuel injection control unit 101, a forced regeneration start determination unit 102, a forced regeneration control unit 103, a regeneration target temperature reset unit 104, and a regeneration state determination unit 105. It should be noted that the control device 100 has the function of obtaining the engine speed (rotational speed) of the engine 1 based on the output of a speed sensor (not shown) and estimating the amount of dust accumulation in the DPF device 5 based on the operating state, etc.

[0039] The fuel injection control unit 101 controls the fuel injection device (not shown) of the engine 1 to perform, for example, post-injection during forced regeneration, according to instructions from, for example, the forced regeneration control unit 103.

[0040] The forced regeneration start determination unit 102, based on the pressure difference of the DPF 52 detected by pressure sensors 96 and 97, requests the start of forced regeneration when the pressure difference exceeds a predetermined threshold. In this embodiment, the forced regeneration start determination unit 102 makes the state requiring the start of forced regeneration a state with a regeneration requirement. The state with a regeneration requirement can be set to a state without a regeneration requirement, for example, by the regeneration state determination unit 105, either when regeneration is determined to be complete, or when regeneration is determined to be unable to be completed and regeneration is terminated.

[0041] When regeneration is required, the forced regeneration control unit 103 performs temperature control during forced regeneration as follows: For example, the forced regeneration control unit 103 uses the control of the engine 1's post-injection and the control of the HC feed rate from the HC distributor 7 to provide feedback on the DOC outlet temperature, thereby controlling the DOC outlet temperature to be similar to that required in, for example... Figure 3 The predetermined regeneration target temperature calculated sequentially is consistent with the figure shown. However, the HC is fed (injected) after the DOC inlet temperature reaches the activation temperature (ignition temperature, e.g., about 250°C) of the catalyst contained in DOC51.

[0042] Figure 3 The horizontal axis is set to time, and the vertical axis is set to DOC outlet temperature, illustrating the change in the regeneration target temperature. Figure 3 In the illustrated example, the forced regeneration control unit 103 divides the regeneration process into five stages, causing the target regeneration temperature to change. It should be noted that... Figure 3In the example shown, the setting is to have a regeneration request at time tll (there is no regeneration state before time tll). The regeneration state has 5 stages: (1) before the start of regeneration (regeneration state: none), (2) ToWarmUp state before reaching the WarmUp Target temperature (about 350°C), (3) WarmUp state reaching the WarmUp Target temperature, (4) ToTarget state before reaching the Target temperature (500°C level, final target temperature), and (5) Target state reaching the Target temperature.

[0043] The ToWarmUp state is a regeneration state in which the maximum value of the regeneration target temperature is set to the WarmUp Target temperature (for example, 350°C). In the ToWarmUp state, the actual DOC outlet temperature at the time tll at which regeneration is forced to start is set to an initial value, and the regeneration target temperature is calculated in such a manner as to increase to the WarmUp Target temperature until a predetermined time elapses at time t12. The regeneration state from time tll to time t12 is the ToWarmUp state.

[0044] Also, the WarmUp state is a regeneration state in which the regeneration target temperature is fixed at the WarmUp Target temperature (for example, 350°C). The regeneration state from time t12 to time t13 after a predetermined time elapses is the WarmUp state. Note that, hereinafter, there are cases in which the ToWarmUp state and the WarmUp state are collectively referred to as the WarmUp state. Also, in the time from time tll to time t13, there is one temperature rise, for example, of about 2 minutes.

[0045] Also, the ToTarget state is a regeneration state in which the maximum value of the regeneration target temperature is set to the Target temperature - 50°C (for example, 450°C). In the ToTarget state, the WarmUp Target temperature (for example, 350°C) is set to an initial value, and the regeneration target temperature is calculated in such a manner as to increase to the Target temperature - 50°C until a predetermined time elapses at time t14. The regeneration state from time t13 to time t14 is the ToTarget state.

[0046] Also, the Target state is a regeneration state in which the maximum value of the regeneration target temperature is set to the Target temperature (for example, 500°C). In the Target state, the Target temperature - 50°C (for example, 450°C) is set to an initial value, and the regeneration target temperature is calculated in such a manner as to increase to the Target temperature (for example, 500°C) at a predetermined inclination, and, after increasing to the Target temperature, the Target temperature is held fixed. The regeneration state after time t14 is the Target state.

[0047] Figure 4 Set the horizontal axis to time and the vertical axis to DOC inlet temperature, DOC outlet temperature, or HC feed rate to illustrate an example of temperature control. Figure 4 In the example shown, regeneration is required at time t1. Forced regeneration begins at time t1, for example, by using post-injection control, causing the DOC inlet and outlet temperatures to rise. Then, at time t2, when the DOC inlet temperature reaches the HC feed start temperature (e.g., ignition temperature or a predetermined margin temperature held by the ignition temperature), HC feed begins. The DOC outlet temperature is then feedback-controlled to the final value of the regeneration target temperature (Target temperature). Finally, if regeneration ends at time t3, forced regeneration is complete, and HC feed stops. It should be noted that dt1 corresponds to the increase in engine exhaust temperature, and dt2 corresponds to the increase in temperature due to combustion within the DOC51 using fuel supply.

[0048] Next, regarding Figure 2 The regeneration target temperature reset unit 104 will be described below. Under certain conditions, the regeneration target temperature reset unit 104 has the function of resetting the regeneration target temperature to the ToWarmUp state or WarmUp state. When forced regeneration starts and the regeneration state is ToTarget state or Target state, if the regeneration target temperature - DOC outlet temperature becomes, for example, 200°C or higher, the regeneration target temperature reset unit 104, upon receiving extreme feedback, resets the regeneration state to the ToWarmUp state or WarmUp state according to the forced regeneration control unit 103 in a way that prevents the DOC outlet temperature from becoming excessively high. It should be noted that the following condition, "the regeneration target temperature - DOC outlet temperature is 200°C or higher," is used as an example to illustrate the operation.

[0049] Figure 5 This describes an example of the operation of the regeneration target temperature reset unit 104. Figure 5 The processing indicated will be performed when regeneration is required. Figure 5When the processing of the indication is started, first, the regeneration target temperature resetting section 104 acquires the regeneration target temperature and the DOC outlet temperature and the regeneration state (step S101). Next, the regeneration target temperature resetting section 104 determines whether or not the forced regeneration is in progress (step S102). In the case where the forced regeneration is in progress (the case of "Y" in step S102), the regeneration target temperature resetting section 104 determines whether or not the regeneration state is in the ToTarget state or the Target state (step S103). In the case where the regeneration state is in the ToTarget state or the Target state (the case of "Y" in step S103), the regeneration target temperature resetting section 104 determines whether or not the time during which the regeneration target temperature - DOC outlet temperature > 200°C is in progress is a certain time or more (step S104).

[0050] The case where the time during which the regeneration target temperature - DOC outlet temperature > 200°C is in progress is a certain time or more, which is the determination condition in step S104, can be set to correspond to the case where the estimated exhaust temperature (DOC 51 inlet temperature) is below the light-off temperature for a predetermined time or more. As for the temperature condition, since the maximum value of the regeneration target temperature is the final target value of the Target state (Target temperature = for example, 500°C), it is the case where the DOC outlet temperature < 300°C in this example. Also, as for the time condition, by appropriately setting the certain time, it can correspond to the case where the estimated exhaust temperature (DOC 51 inlet temperature) is below the light-off temperature for a predetermined time or more. The certain time can be, for example, the order of several tens of seconds to several minutes.

[0051] In the case where the time during which the regeneration target temperature - DOC outlet temperature > 200°C is in progress is a certain time or more (the case of "Y" in step S104), the regeneration target temperature resetting section 104 resets the regeneration target temperature, issues an instruction to the forced regeneration control section 103 to reset the regeneration state from the WarmUp state (ToWarmUp state or WarmUp state), and increases the warm-up reset count by 1 (step S105). The warm-up reset count indicates the number of times that the regeneration state is reset from the ToTarget state or the Target state to the ToWarmUp state or the WarmUp state during the period from when the regeneration request occurs to when the forced regeneration is completed (the number of times of the warm-up from when the estimated DOC inlet temperature is lower than the light-off temperature to when the estimated DOC inlet temperature is higher than the reset DOC outlet temperature).

[0052] On the other hand, in a case where the regeneration state is not the ToTarget state and also not the Target state (a case of "N" in step S103), or a case where the time during which the regeneration target temperature - DOC outlet temperature > 200°C does not reach a certain time or more (a case of "N" in step S104), the regeneration target temperature resetting section 104 executes the process after step S101 again.

[0053] On the other hand, in a case where the regeneration state is not the ToTarget state and also not the Target state (a case of "N" in step S103), or a case where the time during which the regeneration target temperature - DOC outlet temperature > 200°C does not reach a certain time or more (a case of "N" in step S104), the regeneration target temperature resetting section 104 executes the process after step S101 again. Figure 5 The process is completed.

[0054] Next, the regeneration state determination section 105 will be described. Figure 2 The regeneration state determination section 105 determines in which state the temperature control is in in a case where the DOC outlet temperature does not reach the Target temperature at the time of forced regeneration, and notifies the user of the result of the determination, the reason, the processing method, and the like. In the present embodiment, in the case of forced regeneration, the case where the DOC outlet temperature does not reach the Target temperature is classified into three cases of inefficient regeneration (1), inefficient regeneration (2), and regeneration not completed.

[0055] Inefficient regeneration (1): a case where the exhaust gas temperature (DOC inlet temperature) reaches the light-off temperature, but HC does not burn in the DOC 51 due to deterioration of the catalyst of the DOC 51, and the DOC outlet temperature does not reach the Target temperature (for example, 500°C).

[0056] Inefficient regeneration (2): a case where the DOC inlet temperature exceeds the light-off temperature and frequently fluctuates up and down due to the operating state or the like, HC injection is frequently stopped, and the DOC outlet temperature does not reach the Target temperature.

[0057] Regeneration not completed: a case where the exhaust gas temperature does not reach the light-off temperature (250°C) due to a failure of the engine or the like, and thus HC injection cannot be performed, and the DOC outlet temperature does not reach the Target temperature.

[0058] In order to distinguish the above cases, as Figure 6The regeneration state determination section 105 determines the state of the failure more accurately by counting the number of resets including the DOC inlet temperature, the DOC outlet temperature, the regeneration state, and the regeneration target temperature. Further, the regeneration state determination section 105 can notify information indicating the determination result, such as a failure code, to a predetermined notification target, and can also notify information indicating a warning to the user. Here, the predetermined notification target is, for example, a server outside that remotely manages the operation state of the engine control system 10 and the like, a notification target outside that is registered in advance on a WEB system and the like, and the like. Further, the regeneration state determination section 105 can also notify the user of the prescribed information based on the determination result using the display 8.

[0059] Referring to Figure 7 An example of the operation of the regeneration state determination section 105 will be described. Figure 7 The processing indicated by the arrow is executed in the case where the regeneration is required. If Figure 7 The processing indicated by the arrow starts, and first, the regeneration state determination section 105 acquires the DOC inlet temperature, the DOC outlet temperature, and the number of resets of the temperature increase (step S201). Next, the regeneration state determination section 105 determines whether the time after the regeneration was required is 2 hours or more (step S202). The 2 hours in this case is only an example of a second determination time that is longer than the first determination time.

[0060] In the case where the time after the regeneration was required is 2 hours or more (the case where "Y" in step S202), the regeneration state determination section 105 determines that the regeneration has not ended and notifies a message that the regeneration is not started due to the engine failure or the like (step S210), and then, requests the custom manual regeneration (step S211). In step S211, for example, a response to the request for the custom manual regeneration is waited for for a certain time, and in the case where there is no response and also there is no increase in the DOC outlet temperature, a warning is issued again, and Figure 7 The processing indicated by the arrow is completed.

[0061] On the other hand, in a case where the time after the regeneration is requested is not 2 hours or more (a case of "N" in step S202), the regeneration state determination part 105 determines whether the number of times of resetting the regeneration from the WarmUp state is X or more (X is an arbitrary natural number) based on the number of times of the warm-up reset (step S203). In a case where the number of times of resetting the regeneration from the WarmUp state is X or more (a case of "Y" in step S203), the regeneration state determination part 105 determines the case of the inefficient regeneration (2) and notifies a warning or the like (step S207), and determines whether the regeneration end condition is reached (step S205). The regeneration end condition is, for example, a case where the PM accumulation amount estimated from the temperature change or the like according to the regeneration control is below a predetermined threshold value, a case where the DOC outlet temperature reaches the Target temperature - 50°C in a time of a predetermined threshold value or more, or the like, with the estimated value of the PM accumulation amount or the like as an initial value. In a case where the regeneration end condition is reached (a case of "Y" in step S205), the regeneration state determination part 105 completes the forced regeneration (sets the regeneration request to have no regeneration request) (step S206), and then Figure 7 the processing indicated by the arrow is completed. On the other hand, in a case where the regeneration end condition is not reached (a case of "N" in step S205), the regeneration state determination part 105 executes the processing after step S201 again.

[0062] On the other hand, in a case where the number of times of resetting the regeneration from the WarmUp state is not X or more (a case of "N" in step S203), the regeneration state determination part 105 determines whether the time during which the DOC outlet temperature is below the Target temperature - 50°C in the HC supply is 1 hour or more (step S204). Here, in the HC supply, the state in which the DOC inlet temperature reaches the HC supply start temperature (for example, the light-off temperature or a temperature at which the light-off temperature has a predetermined margin) will continue. Also, the 1 hour of this case is one example of the first determination time.

[0063] In a case where the time during which the DOC outlet temperature is below the Target temperature - 50°C in the HC supply is 1 hour or more (a case of "Y" in step S204), the regeneration state determination part 105 determines the case of the inefficient regeneration (1) and notifies a message or the like indicating the possibility of the failure of the DOC 51 (step S208), then requests the custom manual regeneration (step S209), and completes the forced regeneration (sets the regeneration request to have no regeneration request) (step S206), and then Figure 7 the processing indicated by the arrow is completed.

[0064] On the other hand, in the case where the time during which the DOC outlet temperature is below the Target temperature - 50°C in the HC supply is not more than 1 hour (the case of "N" in Step S204), the regeneration state determination part 105 determines whether the regeneration end condition is satisfied (Step S205). In the case where the regeneration end condition is satisfied (the case of "Y" in Step S205), the regeneration state determination part 105 completes the forced regeneration (sets the regeneration request to have no regeneration request) (Step S206), and then Figure 7 the processing is completed. On the other hand, in the case where the regeneration end condition is not satisfied (the case of "N" in Step S205), the regeneration state determination part 105 executes the processing after Step S201 again.

[0065] The determination condition, the determination result, the countermeasure, and the like of the regeneration state determination part 105 are collectively shown in Table 1. Figure 8

[0066] In the case of the low-efficiency regeneration (1), the determination condition is that the time during which the DOC outlet temperature is below the Target temperature - 50°C in the HC supply is more than 1 hour. The state of the engine 1 is not problematic. The state of the DPF device 5 is that there is a possibility that the DOC 51 is deteriorated. The operation state of the vehicle on which the engine 1 is mounted is not problematic. The countermeasure is to request the custom manual regeneration. In the case where the custom manual regeneration cannot be eliminated, the failure inspection associated with the DPF device 5 is performed. As the failure inspection, for example, the DOC efficiency measurement, the DOC dry operation, and the like are performed. Note that the DOC efficiency can be calculated by the formula of (heat of the heat converted by the DOC / heat of the HC injected for regeneration) * 100. Further, the DOC dry operation is an operation for removing the unburned fuel and dust adhered to the DOC inlet by the engine exhaust gas temperature rise control + no regeneration HC injection.

[0067] In the case of the low-efficiency regeneration (2), the determination condition is that the number of times of resetting the regeneration from the WarmUp state is more than X times. The state of the engine 1 and the state of the DPF device 5 are not problematic. The operation state of the vehicle is that the load variation is large and the DOC inlet temperature is frequently below 250°C. The countermeasure is to suggest the custom manual regeneration and to warn that the operation state of the vehicle is in a state where the load variation is large (for example, a notification that advises the change of the operation state of the vehicle to a state where the load variation is small).

[0068] ​In the case where the regeneration is not completed, the determination condition is that the time after the regeneration request reaches 2 hours or more. The state of the engine is a state where a failure occurs, a state where the low-idle state (an idle state of the lowest rotation speed of the engine which does not stop) is pending. As a result of the case where the low-idle state is pending, the forced regeneration cannot be started because the light-off temperature is not reached, for example, by the notification target confirmation operation state (pending time or the like) according to the determination result of the regeneration state determination section 105, the cause can be specific. The state of the DPF device 5 and the operation state of the vehicle are not problematic. The countermeasure is to request the custom manual regeneration. In the case where the custom manual regeneration cannot be eliminated, the engine is subjected to failure inspection (VGT (Variable Geometry Turbine) failure, blow-by or the like).

[0069] Next, with reference to Figure 9 , the change in the HC supply state in the case of the low-efficiency regeneration (1), the low-efficiency regeneration (2), and the case where the regeneration is not completed will be described. Figure 9 The horizontal axis is set to time, and the state of the HC supply (in execution (in control) or in stop) in the case of the low-efficiency regeneration (1), the low-efficiency regeneration (2), and the case where the regeneration is not completed is sequentially indicated from top to bottom. Note that, Figure 9 In the case of the low-efficiency regeneration (1), the forced regeneration is requested at time t21, the state where 1 hour has passed from time t21 is indicated at time t22, and the state where 2 hours have passed from time t21 is indicated at time t23.

[0070] The case of the low-efficiency regeneration (1) is a state where the exhaust temperature continuously reaches the light-off temperature, and the HC supply is continuously executed. The case of the low-efficiency regeneration (2) is a state where the exhaust temperature intermittently reaches the light-off temperature, and the HC supply is intermittently executed. The case where the regeneration is not completed is a state where the exhaust temperature continuously does not reach the light-off temperature, and the HC supply is continuously stopped. However, in this example, in the case where the regeneration is not completed, the exhaust temperature reaches the light-off temperature before time T20 of time t23, and becomes a state where the HC supply is executed before time T20 of time t23, but the regeneration completion condition is not satisfied before time t23 is reached.

[0071] Next, with reference to Figure 10 An operation example of the regeneration state determination section 105 in the case where the forced regeneration is in a state of being cut off or interrupted will be described. In Figure 10 The processing indicated by the flowchart is executed in the case where the regeneration is requested. Figure 10 At the start of the processing indicated by the flowchart, first, the regeneration state determination section 105 acquires the DOC outlet temperature, the engine rotation speed, and the estimated value of the soot accumulation amount (step S301). Next, the regeneration state determination section 105 determines whether the regeneration stop condition is reached (step S302). The regeneration stop condition is, for example, engine stop (cut off) according to the engine being off, interruption of the regeneration according to the user or the like.

[0072] In a case where the regeneration stop condition is reached (the case of "Y" in step S302), the regeneration state determination portion 105 repeatedly executes the process of step S301 and step S302 until the regeneration stop condition disappears.

[0073] On the other hand, in a case where the regeneration stop condition is not reached (the case of "N" in step S302), the regeneration state determination portion 105 issues an instruction to execute forced regeneration to the forced regeneration control portion 103 (step S303), and determines whether the regeneration end condition is reached (step S304). In a case where the regeneration end condition is reached (the case of "Y" in step S304), the regeneration state determination portion 105 completes the forced regeneration (sets the regeneration request to have no regeneration request) (step S305), and then Figure 10 the process is completed. On the other hand, in a case where the regeneration end condition is not reached (the case of "N" in step S304), the regeneration state determination portion 105 executes the process after step S301 again.

[0074] (Action and Effect)

[0075] As described above, according to the present embodiment, the control device 100 includes the DPF 52 (filter) that collects particulate matter in exhaust gas of the engine 1 and the DOC 51 (oxidation catalyst) provided upstream of the DPF 52, includes the regeneration state determination portion 105 in the DPF device 5 (exhaust gas aftertreatment device) that regenerates the DPF 52 by the action of the DOC 51, and the regeneration state determination portion 105, in a case where forced regeneration that forcibly raises the temperature of the exhaust gas is executed, notifies a message that there is a problem in the operation state of the engine 1 when the number of times that the temperature of the exhaust gas is presumed to be below the light-off temperature for a predetermined time or more exceeds a predetermined threshold value (X times). According to such a configuration, it is possible to notify a problem in the operation state or the like during forced regeneration.

[0076] Note that the regeneration state determination portion 105 can notify a message that the DOC 51 (oxidation catalyst) has a possibility of developing a failure in a case where it is determined that the forced regeneration has not ended even though the time during which the temperature of the exhaust gas is presumed to be above the light-off temperature has elapsed for a first determination time (1 hour) or more.

[0077] Further, the regeneration state determination portion 105 can notify a message that the engine has a possibility of developing a failure in a case where it is determined that the forced regeneration has not ended even though the time after the start of the forced regeneration has elapsed for a second determination time (2 hours) or more that is longer than the first determination time.

[0078] The above describes the embodiments of the application with reference to the drawings, and the specific configuration is not limited to the above-described embodiments, and includes design changes and the like within the scope of the gist of the application. For example, the exhaust gas aftertreatment device of the above-described embodiments is configured by the DPF device 5, and for example, further, an SCR device (Selective Catalytic Reduction device) can be provided downstream, or for example, an SCR device can also be provided downstream, and the DPF 52 can be omitted from the DPF device 5. Also, a part or all of the program executed by the control device 100 can be distributed through a computer-readable recording medium or a communication line.

[0079] Industrial Applicability

[0080] According to the above-described embodiments, it is possible to notify of a problem in the operation state and the like during forced regeneration.

[0081] Explanation of Reference Numerals:

[0082] 1...engine, 3...exhaust pipe, 5...DPF device, 7...HC distributor, 51...DOC, 52...DPF, 94...DOC inlet temperature sensor, 95...DOC outlet temperature sensor, 96, 97...pressure sensor, 100...control device, 105...regeneration state determination section

Claims

1. A control device for an engine, characterized in that, In an exhaust aftertreatment device that includes a filter for collecting particulate matter from engine exhaust and an oxidation catalyst disposed upstream of the filter, and regenerates the filter using the action of the oxidation catalyst, a forced regeneration process is performed that forces a rise in the temperature of the exhaust gas. When the regeneration state determination unit determines that the exhaust temperature has been below the ignition temperature for a predetermined period of time more than a predetermined number of times, the regeneration state determination unit determines that the exhaust temperature has been below the ignition temperature for a predetermined period of time more than a predetermined number of times. The message indicates that there is a problem with the engine's operating status.

2. The control device for the engine according to claim 1, characterized in that, The regeneration status determination unit also notifies a message that there is a possibility of a malfunction in the oxidation catalyst if it determines that the forced regeneration has not ended even if the time during which the exhaust temperature is presumed to be above the ignition temperature has exceeded the first determination time.

3. The engine control device according to claim 2, characterized in that, The regeneration status determination unit also determines that if the forced regeneration has not ended even after a second determination time that is longer than the first determination time, it will notify a message indicating the possibility of engine failure.

4. A method for notifying an engine, characterized in that, The notification method Includes the following steps, In an exhaust aftertreatment device that includes a filter for collecting particulate matter from engine exhaust and an oxidation catalyst disposed upstream of the filter, and regenerates the filter using the action of the oxidation catalyst, forced regeneration that forces an increase in the temperature of the exhaust gas is performed. When the number of times the estimated exhaust temperature is below the ignition temperature for a predetermined period of time exceeds a predetermined threshold, The message indicates that there is a problem with the engine's operating status.

Images