SAMPLING DEVICE, SAMPLING METHOD AND EXHAUST GAS PURIFICATION DEVICE WITH SAMPLING DEVICE
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- ISUZU MOTORS LTD
- Filing Date
- 2019-12-25
- Publication Date
- 2026-07-23
Abstract
Description
TECHNICAL AREA
[0001] The present disclosure relates to a detection device, a detection method and an exhaust gas purification device comprising the detection device. STATE OF THE ART
[0002] An example of an exhaust gas purification device is one that includes a particulate filter (hereinafter referred to as the filter) which collects particulate matter (hereinafter referred to as PM) in exhaust gas emitted by an internal combustion engine. In this type of exhaust gas purification device, the amount of PM accumulated in the filter is estimated based on an upstream-downstream differential pressure of the filter, and a so-called filter regeneration process for burning and removing PM is carried out periodically when the PM accumulation reaches a predetermined level.
[0003] Even if filter regeneration is performed periodically, the filter can enter a so-called PM excess accumulation state, in which PM accumulates excessively within the filter. If filter regeneration is performed in such a PM excess accumulation state, cracks or erosion of the filter can occur due to thermal runaway or the like, caused by rapid combustion of excessively accumulated PM. As a technique to prevent such filter erosion or the like, patent literature 1, for example, discloses a technique for preventing filter regeneration when the PM accumulation quantity exceeds a predetermined upper limit. CITATION LIST PATENT LITERATURE
[0004] Patent Literature 1: JP-A-2006-316733 SUMMARY OF THE INVENTIONAL PROBLEM
[0005] For example, if the exhaust aftertreatment system is located in a low-temperature environment after the engine has been stopped, condensation may form in the exhaust pipe due to condensation or similar processes. If such condensation adheres to the PM particles collected in the filter, the PM may collapse due to the influence of exhaust gas flowing into the filter after the engine is started, or similar factors. When the PM particles collapse, one cell of the filter becomes partially clogged, increasing the differential pressure. This can lead to a false positive reading of excess PM accumulation, even though no excessive PM has actually been collected in the filter.
[0006] One purpose of the present revelation is to effectively capture the collapse of PM that has been collected in a filter. SOLUTION TO THE PROBLEM
[0007] A detection device of the present disclosure is a detection device configured to detect the collapse of particulate mass collected in a filter provided in an exhaust system flow path of an internal combustion engine, wherein the detection device comprises: a differential pressure detection means for detecting a differential pressure between an exhaust inlet side and an exhaust outlet side of the filter; a water generation determination means for determining whether water is generated in the exhaust system flow path;and a collapse determination device for determining that at least part of the particle mass collected in the filter has collapsed if, within a predetermined time, the detected differential pressure has increased by a predetermined differential pressure or more, or a particle mass accumulation quantity in the filter, estimated based on the detected differential pressure, has increased by a predetermined accumulation quantity or more within the predetermined time period in a state in which: the detected differential pressure is equal to or greater than a predetermined first differential pressure threshold, or the estimated particle mass accumulation quantity in the filter is equal to or greater than a predetermined first accumulation quantity threshold; and the water generation determination device has determined that water is being generated.
[0008] Furthermore, it is preferred that the detection device further comprises a water temperature detection means for detecting a water temperature of the cooling water of the internal combustion engine, and the water generation determining means determines that water is generated in the exhaust system flow path in a case where a water temperature decrease amount during a stop period, obtained by subtracting a restart time water temperature from a stop time water temperature, is equal to or greater than a predetermined amount, wherein the water temperature at the restart time is detected by the water temperature detection means when the internal combustion engine is restarted, and the stop time water temperature is detected by the water temperature detection means when the internal combustion engine is stopped.
[0009] An exhaust gas purification device of the present disclosure is an exhaust gas purification device comprising: the detection device described above; the filter; an oxidation catalyst provided in the exhaust system flow path on an upstream side of the filter; a fuel supply means for supplying unburned fuel to the oxidation catalyst; and a filter regeneration means for carrying out a filter regeneration in which the particulate mass accumulated in the filter is burned and removed by supplying the unburned fuel through the fuel supply means when the collapse determining means determines that the particulate mass has collapsed.
[0010] Furthermore, it is preferred that the filter regeneration agent also performs filter regeneration when the detected differential pressure has reached a predetermined second differential pressure threshold that is greater than the first differential pressure threshold, or when the particle mass accumulation amount in the filter, estimated based on the differential pressure, has reached a predetermined second accumulation amount threshold that is greater than the first accumulation amount threshold.
[0011] Furthermore, it is preferred that the exhaust gas purification device further comprises: an excess accumulation determiner for determining an excess accumulation state in which the particle mass is excessively accumulated in the filter when the detected differential pressure has reached a predetermined third differential pressure threshold that is greater than the second differential pressure threshold, or when the particle mass accumulation amount in the filter, estimated based on the differential pressure, has reached a predetermined third accumulation amount threshold that is greater than the second accumulation amount threshold; and a preventer for preventing the filter regeneration agent from performing filter regeneration when the excess accumulation state is determined by the excess accumulation determiner.
[0012] A detection method of the present disclosure is a detection method for detecting the collapse of particulate mass collected in a filter provided in an exhaust system flow path of an internal combustion engine, wherein the detection method comprises: detecting a differential pressure between an exhaust inlet side and an exhaust outlet side of the filter and determining whether water is generated in the exhaust system flow path;and determine that at least part of the particle mass collected in the filter has collapsed if the detected differential pressure has increased by a predetermined differential pressure or more within a predetermined period, or if a particle mass accumulation amount in the filter, estimated based on the detected differential pressure, has increased by a predetermined accumulation amount or more within the predetermined period in a state where: the detected differential pressure is equal to or greater than a predetermined first differential pressure threshold, or the particle mass accumulation amount in the filter, estimated based on the differential pressure, is equal to or greater than a predetermined first accumulation amount threshold; and determine that water is generated in the exhaust system flow path. ADVANTAGEOUS EFFECTS OF THE INVENTION
[0013] According to the technique of the present disclosure, the collapse of PM collected in the filter can be effectively detected. List of characters Fig. Figure 1 is a schematic overall configuration diagram showing an exhaust system of an internal combustion engine according to the present embodiment. Fig. Figure 2 is a schematic functional block diagram showing an electronic control unit and an associated peripheral configuration according to the present embodiment. Fig. Figure 3A is a schematic diagram illustrating an example of a flow until PM, which has accumulated in a filter according to the present embodiment, collapses and blocks a cell. Fig. Figure 3B is a schematic diagram illustrating the example of the flow until the PM accumulated in the filter collapses and blocks the cell according to the present embodiment. Fig. Figure 3C is a schematic diagram illustrating the example of the flow until the PM accumulated in the filter collapses and blocks the cell according to the present embodiment. Fig. Figure 4 is a time graph illustrating an example of a change in the upstream-downstream differential pressure of the filter increasing due to PM collapse, and a change in the amount of PM accumulation estimated based on the upstream-downstream differential pressure. Fig. Figure 5 is a flowchart illustrating the acquisition processing and filter regeneration processing according to the present embodiment. DESCRIPTION OF THE EXECUTION FORMS
[0014] The following describes a detection device, a detection method, and an exhaust gas purification device incorporating the detection device according to the present embodiment, with reference to the accompanying drawings. Identical components are identified by the same reference numerals, and their names and functions are also identical. Therefore, detailed descriptions of the same components are not repeated.
[0015] Fig. Figure 1 is a schematic overall configuration diagram showing an exhaust system of an internal combustion engine according to the present embodiment.
[0016] As in Fig. As shown in Figure 1, each cylinder of an engine (internal combustion engine) 10 has an injector nozzle arranged in the cylinder. 11(An example of a fuel delivery device) that injects fuel directly into the cylinder. Fuel injection quantity, injection timing, number of injections, and similar parameters of the injector located in the cylinder. 11 are controlled according to an instruction signal issued by an electronic control unit (ECU) 100 is received.
[0017] The engine 10 is equipped with an exhaust manifold 12 (an example of an exhaust system flow path) that collects exhaust gases emitted from each cylinder. An exhaust pipe 13 (An example of the exhaust system flow path) for the removal of exhaust gas is with the exhaust manifold. 12 connected. The exhaust pipe 13 is equipped with an exhaust pipe injection nozzle 20 (an example of the fuel supply medium), an exhaust aftertreatment device 30and the like in this order provided from an upstream side of the exhaust gas.
[0018] The exhaust aftertreatment device 30 includes a housing 30A (an example of the exhaust system flow path), which connects to the exhaust pipe 13 is connected. An oxidation catalyst 31 and a filter 32 are in this order from the upstream side of the exhaust gas in the housing 30A housed an exhaust gas temperature sensor 90 , which is a temperature TE of the filter 32 captured in the flowing exhaust gas, is located immediately downstream (exhaust section) of the oxidation catalyst. 31 Provided for. At an exhaust gas inlet and an exhaust gas outlet of the filter. 32 is a differential pressure sensor 91 (Differential pressure sensing device) provided, which measures the upstream-downstream differential pressure ΔP of the filter. 32 Recorded sensor values. Sensor readings90 , 91 will be sent to the ECU 100 transmitted, which is electrically connected to the sensors.
[0019] The oxidation catalyst 31 This is formed, for example, by carrying a catalyst component or the like on the surface of a ceramic support, such as a cordierite honeycomb structure. When unburned fuel (HC) is injected by the injector located in the cylinder... 11 or exhaust pipe injection of the exhaust pipe injection nozzle 20 When supplied, the oxidation catalyst oxidizes 31 the unburned fuel to increase the exhaust gas temperature.
[0020] The filter 32For example, it is formed by arranging many cells 32C, which are subdivided by porous partitions 32A, along a flow direction of the exhaust gas and alternately sealing the upstream and downstream ends of the cells 32C with plugs 32B. In the present embodiment, the filter 32 preferably in the housing 30A so that a flow path direction (axial direction) of cell 32C is aligned in a substantially lateral direction (substantially horizontal direction).
[0021] The filter 32 PM collects in the exhaust gas in the pores and surfaces of the partition walls 32A and performs a filter regeneration to periodically burn off and remove the accumulated PM. Filter regeneration is achieved by supplying unburned fuel to the oxidation catalyst. 31 by the post-injection of the injector nozzle located in the cylinder 11and / or the exhaust pipe injection of the exhaust pipe injection nozzle 20 and increasing the temperature of the water in the filter 32 The process involves heating the flowing exhaust gas to a PM combustion temperature (for example, approximately 600°C). Details of the filter regeneration will be described later.
[0022] An engine speed sensor 92 detects an engine speed Ne from a crankshaft (not shown) of the engine 10 A gas pedal opening sensor 93 detects a fuel injection quantity Q (an instruction value for the injector located in the cylinder) 11 ) of the engine 10 according to a pressure applied to an accelerator pedal (not shown). A coolant temperature sensor 94 (Water temperature sensing device) detects a coolant temperature TW in a coolant circuit (not shown) of the engine. 10 . Sensor values of these sensors 92 until 94 will be sent to the ECU 100transmitted, which is electrically connected to the sensors.
[0023] Fig. 2 is a schematic functional block diagram showing the ECU 100 and shows an associated peripheral configuration according to the present embodiment.
[0024] The ECU 100 is configured to have various controls on the motor 10 and the like, and includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), an input port, an output port, and the like.
[0025] The ECU 100 It includes a PM accumulation quantity estimation unit as part of its functional elements. 110 , a water production determination unit 120 , a PM collapse determination unit 130 , a filter regeneration control unit 140 , a PM excess accumulation determination unit150 and a filter regeneration prevention unit 160 These functional elements are referred to as being in the ECU. 100 The integrated hardware is described as provided, however, some of these functional elements may be provided in separate hardware.
[0026] The PM accumulation quantity estimation unit 110 estimates the PM accumulation amount DA of the filter 32 based on the upstream-downstream differential pressure ΔP of the filter 32 , which is from the differential pressure sensor 91 is received. In particular, a memory of the ECU stores 100 a PM accumulation quantity characteristic curve M, which is created in advance and establishes a relationship between the upstream-downstream differential pressure ΔP of the filter. 32and the PM accumulation quantity DA is defined. In the PM accumulation quantity characteristic curve M, the PM accumulation quantity DA is set so that it increases when the upstream-downstream differential pressure ΔP increases. The PM accumulation quantity estimation unit 110 estimates the PM accumulation amount DA of the filter 32 at predetermined intervals or in real time with reference to the PM accumulation quantity characteristic curve M and based on the upstream-downstream differential pressure ΔP, which is measured by the differential pressure sensor 91 is received. A method for estimating the PM accumulation quantity DA is not limited to the method using the characteristic curve M, and the PM accumulation quantity DA can be estimated based on an arithmetic expression or the like.
[0027] The water production determination unit 120determines whether water, such as condensation, which is present due to condensation in the exhaust system flow path including the exhaust pipe. 13 , of the case 30A and similar substances are generated in the exhaust system flow path. Especially when the engine 10 The water generation control unit stores data stored when the process is stopped by an OFF operation of an ignition switch (not shown). 120 a coolant temperature (hereinafter referred to as stop-time coolant temperature TW1) measured by the coolant temperature sensor 94 what was recorded at that time was stored in the ECU's memory 100 Furthermore, the water production determination unit includes 120 , when the engine 10 restarted by an ON operation of the ignition switch, a coolant temperature (hereinafter referred to as a restart time coolant temperature TW2) is determined by the coolant temperature sensor 94at this time. If a water temperature reduction amount ΔTW (=TW1-TW2) during an engine stop period, obtained by subtracting the restart-time coolant temperature TW2 from the stop-time coolant temperature TW1, is equal to or greater than a predetermined upper limit reduction threshold ΔTWMax, then the water generation determination unit determines 120 that water is generated in the exhaust system flow path. The upper limit decrease threshold ΔTMax can be preset, for example, by detecting a water temperature decrease of the cooling water that can cause condensation in the exhaust system flow path, through an experiment or the like, when the engine is running. 10 is placed in a low-temperature environment during the stop period.
[0028] The PM collapse determination unit 130 determines whether a PM collapse occurs, in which the filter 32PM collected from the partition walls 32A of the filter 32 into cell 32C. Here, PM collapse refers to a condition in which, for example, PM particles that have accumulated on the partition walls 32A of the filter... 32 accumulated, as in Fig. 3A shows that water, such as condensation, floats from the partition walls 32A and into an axial midside of cell 32C, as shown in Fig. 3B shown, advances and then, as in Fig. As shown in Figure 3C, the advancing PM collapses under the influence of exhaust gas or the like, which passes through the filter. 32 flows into cell 32C and partially blocks cell 32C.
[0029] The PM collapse determination unit 130 determined that a PM collapse has occurred in a case where, in a state where the PM accumulation quantity estimation unit 110The estimated PM accumulation amount DA is equal to or greater than a predetermined first accumulation amount threshold DA1, indicating that the PM is being filtered to some extent. 32 has accumulated (or if the upstream-downstream differential pressure ΔP is equal to or greater than a predetermined first differential pressure threshold ΔP1) and the water generation determination unit 120 has determined that the water is produced, the PM accumulation quantity DA (or the upstream-downstream differential pressure ΔP), which is determined by the PM accumulation quantity estimation unit 110 is estimated to be increasing at an abnormal rate. Whether a degree of increase in PM accumulation DA corresponds to an abnormal increase can be determined, for example, as in Fig. As shown in Figure 4, the degree of increase of the abnormal increase is determined by specifying that in a case where an increase amount ΔDA of the PM accumulation quantity DA (or an increase amount ΔPInc of the upstream-downstream differential pressure ΔP) increases by a predetermined amount or more from time t1 to time t2, relative to a normal reference PM increase amount ΔDA_ST (or a reference differential pressure increase amount ΔPInc_ST) based on an operating condition of the engine, the increase amount ΔDA_ST is determined by determining that the increase amount ΔDA_ST is the abnormal increase in a case where an increase amount ΔDA_ST of the PM accumulation quantity DA (or an increase amount ΔPInc_ST) is a predetermined amount or more. 10 or similar estimates. The operating condition of the engine. 10 This can be done, for example, by the engine speed sensor 92 , the accelerator pedal opening sensor 93 or similar.
[0030] In this way, by detecting PM collapse based on the degree of increase in the PM accumulation quantity DA during a predetermined time period from time t1 to time t2, a so-called erroneous determination, in which the PM excess accumulation state is determined simply because the PM accumulation quantity DA shows a large value, can be effectively prevented. The determination of PM collapse is not limited to determination based on the PM accumulation quantity DA; the determination can also be performed based on the degree of increase in the upstream-downstream differential pressure ΔP.
[0031] The filter regeneration control unit 140 Filter regeneration leads to the burning and removal of PM from the filter. 32 in a case in which (1) the PM collapse determination unit 130 determines that PM collapse has occurred, or (2) the PM accumulation quantity estimation unit110 The estimated PM accumulation quantity DA has reached a predetermined second accumulation quantity threshold DA2 that is greater than the first accumulation quantity threshold DA1 (or the upstream-downstream differential pressure ΔP has reached a predetermined second differential pressure threshold ΔP2 that is greater than the first differential pressure threshold P1).
[0032] Filter regeneration is carried out by increasing the temperature of the water entering the filter. 32 The flowing exhaust gas is raised to the PM combustion temperature by feeding unburned fuel to the oxidation catalyst. 31 Fuel is supplied via post-injection and / or exhaust port injection. The fuel injection quantity during filter regeneration can be determined, for example, based on a deviation between a target PM combustion temperature and the exhaust gas temperature TE, which is measured by the exhaust gas temperature sensor. 90The detected data is fed back into the system. For example, filter regeneration is stopped when the PM accumulation quantity estimation unit exceeds the limit. 110 The estimated PM accumulation amount DA decreases to a predetermined lower limit accumulation amount (or the upstream-downstream differential pressure ΔP reaches a predetermined lower limit differential pressure) or when a time elapsed since the start of filter regeneration reaches a predetermined upper limit time.
[0033] If the PM accumulation quantity estimation unit 110 The PM excess accumulation determination unit determines the estimated PM accumulation quantity DA reaches a predetermined third accumulation quantity threshold DA3 that is greater than the second accumulation quantity threshold DA2, (or when the upstream-downstream differential pressure ΔP reaches a predetermined third differential pressure threshold ΔP3 that is greater than the second differential pressure threshold ΔP2).150 a PM excess accumulation state in which the PM is excessively concentrated in the filter 32 has accumulated. When the PM excess accumulation state is determined, a warning is issued, prompting a display device 200 to indicate that filter maintenance is required. 32 is required. A warning procedure is not particularly restricted, and the warning can be issued by a tone from a loudspeaker 210 or the like.
[0034] If the PM excess accumulation determination unit 150 The PM excess accumulation state is determined by the filter regeneration prevention unit. 160 the filter regeneration control unit 140 to perform filter regeneration. The prohibition on filter regeneration is lifted when the filter 32 undergoes maintenance (e.g., cleaning, replacement, or the like) in a maintenance facility or similar.
[0035] Next, a sequence of acquisition processing and filter regeneration processing according to the present embodiment will be described with reference to Fig. 5 described. This routine is implemented, for example, by operating the engine's ignition switch in the ON position. 10 started.
[0036] In step S100, it is determined whether the filter is based on the upstream-downstream differential pressure ΔP. 32 The estimated PM accumulation quantity DA is equal to or greater than the predetermined first accumulation quantity threshold DA1. If the PM accumulation quantity DA is equal to or greater than the first accumulation quantity threshold DA1 (Yes), the controller proceeds to step S110. Conversely, if the PM accumulation quantity DA is less than the first accumulation quantity threshold DA1 (No), the controller repeats the determination process in step S100.
[0037] In step S110, it is determined whether the water temperature decrease ΔTW (=TW1 - TW2) during an engine stop period, which is obtained by subtracting the current coolant temperature TW2 at the time of restart from the coolant temperature TW1 stored at the time of the previous engine stop, is equal to or greater than the predetermined upper limit decrease threshold ΔTW Max is. In a case where the water temperature decrease amount ΔTW is equal to or greater than the upper limit decrease amount threshold (ΔTW) Max (Yes) if the answer is yes, the control system proceeds to step S120. On the other hand, if the water temperature decrease amount ΔTW is less than the upper limit decrease amount threshold ΔTW, the control system proceeds to step S120. Max (No) is, the control for determining step S150 continues. The processing of step S100 and step S110 can be carried out in random order.
[0038] In step S120, it is determined that water is present in the exhaust system flow path, including the exhaust pipe. 13 , of the case 30A and the like. Next, in step S130, it is determined whether the soot accumulation amount DA, estimated based on the upstream-downstream differential pressure ΔP, has increased at an abnormal rate within a predetermined time period. If the PM accumulation amount DA has increased abnormally (Yes), the controller proceeds to step S140, determines that a PM collapse has occurred, and continues with the processing of step S200. Conversely, if the PM accumulation amount DA has not increased abnormally (No), the controller continues with the determination in step S150.
[0039] In step S150, it is determined whether the PM accumulation quantity DA, estimated based on the upstream-downstream differential pressure ΔP, is equal to or greater than the predetermined second accumulation quantity threshold DA2. If the PM accumulation quantity DA is equal to or greater than the second accumulation quantity threshold DA2 (Yes), the controller proceeds to the determination in step S160. Conversely, if the PM accumulation quantity DA is less than the second accumulation quantity threshold DA2 (No), the controller repeats the determination process of step S150.
[0040] In step S160, it is determined whether the PM accumulation amount DA, estimated based on the upstream-downstream differential pressure ΔP, is equal to or greater than the predetermined third accumulation threshold DA3. If the PM accumulation amount DA is equal to or greater than the third accumulation threshold DA3 (Yes), the controller proceeds to step S300, the PM excess accumulation state is determined, filter regeneration in step S310 is prevented, and the controller terminates. Conversely, if the PM accumulation amount DA is less than the third accumulation threshold DA3 (No), the controller proceeds to processing step S200.
[0041] When the control system progresses from step S140 or step S160 to step S200, filter regeneration is performed based on post-injection or exhaust port injection. Next, in step S210, it is determined whether a filter regeneration end condition has been met. The filter regeneration end condition can be met if the PM accumulation quantity (DA) decreases to a predetermined lower limit or if the time elapsed since the start of filter regeneration reaches a predetermined upper limit. If the end condition is met (Yes), the control system proceeds to determine step S220. If the end condition is not met (No), the control system continues with the processing of step S200.
[0042] Step S220 determines whether the motor 10is stopped by the ignition switch being in the OFF position. In a case where the engine 10 If the motor is not stopped (No), the controller returns to processing step S100. In a case where the motor is not stopped, the controller returns to processing step S100. 10 If stopped (Yes), the control unit continues with the processing of step S230; the stop time coolant temperature TW1 is stored in the ECU's memory. 100 saved, after which the control is terminated.
[0043] According to the embodiment described in detail above, in a case where the estimated PM accumulation quantity DA has increased at an abnormal rate during a predetermined period from time 1t to time t2, in a state where the PM accumulation quantity DA of the filter 32equal to or greater than the first accumulation threshold DA1 and it is determined that water is being generated in the exhaust system flow path, it is determined that PM collapse has occurred, in which at least some of the PM that was in the filter 32 The PM collapse has occurred. This means that a PM collapse can be effectively detected based on the degree of increase in the PM accumulation quantity DA during the predetermined time period from time t1 to time t2. Therefore, it is possible to effectively prevent a so-called erroneous determination, in which the PM excess accumulation state is uniformly determined by simply showing a large PM accumulation quantity DA value, even though the PM is not actually excessively present in the filter. 32 is collected.
[0044] Furthermore, when PM collapse is detected, filter regeneration is performed to burn off and remove the PM. Therefore, when PM collapse occurs, the PM that partially blocks cell 32C due to the collapse is adequately burned off and removed, and the filter... 32 It can still be used even after the collapse of the PM.
[0045] The present disclosure is not limited to the embodiment described above and can be modified and implemented in a suitable manner without departing from the spirit of the present disclosure.
[0046] For example, in the Fig. The flow shown in section 5 can be used to determine whether the temperature of the oxidation catalyst is high. 31 has reached a predetermined activation temperature (for example, about 200°C), based on a sensor value from the exhaust gas temperature sensor. 90before the filter regeneration is performed in step S200, and when the temperature of the oxidation catalyst 31 If the activation temperature has not been reached, a catalyst temperature increase control can be implemented to cause an intake throttle valve or the injector located in the cylinder to open. 11 performs an early post-injection (where the injection is carried out at a time close to a post-injection).
[0047] In the above embodiment, filter regeneration is carried out by post-injection or exhaust pipe injection, but the filter 32 It may be equipped with a heater or similar device, and the PM can be burned off and removed by the heater. The motor 10 is not limited to the four-cylinder engine shown and can be a single-cylinder engine or a multi-cylinder engine that differs from the four-cylinder engine.
[0048] The present application is based on Japanese patent application No. 2018-248797, filed on December 29, 2018, the contents of which are included here for reference. COMMERCIAL APPLICABILITY
[0049] The detection device, the detection method and the exhaust gas purification device including the detection device of the present disclosure are useful insofar as the collapse of the PM accumulated in the filter can be effectively detected. Reference symbol list 10: Engine (internal combustion engine) 11: Fuel injector located in the cylinder (fuel supply unit) 12: Exhaust manifold (exhaust system flow path) 13: Exhaust pipe (exhaust system flow path) 20: Exhaust pipe injection nozzle (fuel supply unit) 30: Exhaust aftertreatment device 30A: Housing (exhaust system flow path) 31: Oxidation catalyst 32: Filter 90: Exhaust gas temperature sensor 91: Differential pressure sensor (differential pressure sensing device) 92: Engine speed sensor 93: Accelerator pedal opening sensor 94: Coolant temperature sensor (water temperature sensing device) 100: ECU 110: PM accumulation quantity estimation unit 120: Water production determination unit (water production determination tool) 130: PM collapse determination unit (collapse determination agent) 140: Filter regeneration control unit (filter regeneration fluid) 150: PM excess accumulation determination unit (PM excess accumulation determination agent) 160: Filter regeneration prevention unit (prevention agent) QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] JP 2006316733 A
[0004] JP 2018248797
[0048]
Claims
[1] Detection device configured to detect the collapse of particulate mass collected in a filter provided in an exhaust system flow path of an internal combustion engine, the detection device comprising: a differential pressure sensing device for detecting a differential pressure between an exhaust gas inlet side and an exhaust gas outlet side of the filter; a water generation determination tool for determining whether water is generated in the exhaust system flow path; and A collapse determination device for determining that at least part of the particle mass collected in the filter has collapsed if the detected differential pressure has increased by a predetermined differential pressure or more within a predetermined time, or if a particle mass accumulation quantity in the filter, estimated based on the detected differential pressure, has increased by a predetermined accumulation quantity or more within the predetermined time period in a state in which: the detected differential pressure is equal to or greater than a predetermined first differential pressure threshold or the estimated particle mass accumulation in the filter, based on the differential pressure being equal to or greater than a predetermined first accumulation threshold; and the water generation determiner has determined that water is being generated. [2] Detection device according to claim 1, further comprising: a water temperature sensing device for measuring the water temperature of the cooling water of the internal combustion engine, wherein the water generation determiner determines that water is generated in the exhaust system flow path in a case where a water temperature decrease amount during a stop period, obtained by subtracting a restart time water temperature from a stop time water temperature, is equal to or greater than a predetermined amount, wherein the restart time water temperature is detected by the water temperature detection means when the internal combustion engine is restarted, and the stop time water temperature is detected by the water temperature detection means when the internal combustion engine is stopped. [3] Exhaust gas purification device comprising the following: the detection device according to claim 1 or 2; the filter; an oxidation catalyst that is provided in the exhaust system flow path on an upstream side of the filter; a fuel supply device for supplying unburned fuel to the oxidation catalyst; and A filter regeneration agent for carrying out a filter regeneration in which the particle mass accumulated in the filter is burned and removed by supplying the unburned fuel through the fuel supply agent when the collapse determining agent determines that the particle mass has collapsed. [4] Exhaust gas purification device according to claim 3, wherein the filter regeneration agent also performs filter regeneration when the detected differential pressure has reached a predetermined second differential pressure threshold that is greater than the first differential pressure threshold, or when the particle mass accumulation amount in the filter estimated on the basis of the differential pressure has reached a predetermined second accumulation amount threshold that is greater than the first accumulation amount threshold. [5] Exhaust gas purification device according to claim 4, further comprising: an excess accumulation determiner for determining an excess accumulation state in which the particle mass is excessively accumulated in the filter when the detected differential pressure has reached a predetermined third differential pressure threshold greater than the second differential pressure threshold, or when the particle mass accumulation amount in the filter, estimated based on the differential pressure, has reached a predetermined third accumulation amount threshold greater than the second accumulation amount threshold; and a preventive agent to prevent the filter regeneration agent from performing filter regeneration when the excess accumulation state is determined by the excess accumulation determiner. [6] Detection method for detecting the collapse of particulate mass collected in a filter provided in an exhaust system flow path of an internal combustion engine, the detection method comprising: Determining the differential pressure between an exhaust inlet side and an exhaust outlet side of the filter and determining whether water is generated in the exhaust system flow path; and Determine that at least part of the particle mass collected in the filter has collapsed if the detected differential pressure has increased by a predetermined differential pressure or more within a predetermined period, or if a particle mass accumulation amount in the filter, estimated based on the detected differential pressure, has increased by a predetermined accumulation amount or more within the predetermined period in a state in which: the detected differential pressure is equal to or greater than a predetermined first differential pressure threshold, or the amount of particle mass accumulated in the filter, estimated based on the differential pressure, is equal to or greater than a predetermined first accumulation threshold; and the determination confirms that water is generated in the exhaust system flow path.