WO2021241703A1 - Filter state detection device - Google Patents

Filter state detection device Download PDF

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Publication number
WO2021241703A1
WO2021241703A1 PCT/JP2021/020267 JP2021020267W WO2021241703A1 WO 2021241703 A1 WO2021241703 A1 WO 2021241703A1 JP 2021020267 W JP2021020267 W JP 2021020267W WO 2021241703 A1 WO2021241703 A1 WO 2021241703A1
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WO
WIPO (PCT)
Prior art keywords
filter
differential pressure
particulate matter
detection device
calculation unit
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PCT/JP2021/020267
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French (fr)
Japanese (ja)
Inventor
薫 田中
裕行 荒木
主斗 石川
Original Assignee
いすゞ自動車株式会社
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Application filed by いすゞ自動車株式会社 filed Critical いすゞ自動車株式会社
Priority to CN202180037241.1A priority Critical patent/CN115667680A/en
Publication of WO2021241703A1 publication Critical patent/WO2021241703A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • This disclosure relates to a filter state detection device.
  • a filter that captures particulate matter (Particulate Matter) contained in exhaust gas has been arranged in the exhaust pipe, and a filter state detection device that detects the state of this filter has been put into practical use.
  • a filter state detection device there is known a technique of calculating the deposited amount of particulate matter in the filter based on the filter differential pressure on the upstream side and the downstream side of the filter.
  • the filter state detection device can calculate the amount of ash deposited among the particulate matter based on the filter differential pressure.
  • This ash is a nonflammable substance caused by metal oxides and sulfates contained in engine oil and fuel additives, and it is difficult to remove it by the regeneration process of a filter that burns particulate matter at high temperature. .. Therefore, by calculating the amount of ash deposited, it is possible to determine the timing of maintenance such as cleaning and replacement of the filter, for example. Here, it is required to accurately determine the maintenance time of the filter.
  • Patent Document 1 discloses a DPF regeneration processing control method in which the accuracy of determining the presence or absence of a DPF failure is improved.
  • this regeneration processing control method the threshold value for determining the over-deposition of particulate matter is changed based on the amount of ash deposited, so that the maintenance time of the filter can be accurately determined in consideration of the amount of ash deposited.
  • the regeneration processing control method of Patent Document 1 determines the amount of particulate matter deposited on the filter based only on the filter differential pressure on the upstream side and the downstream side of the filter. Since the filter differential pressure changes greatly depending on the flow rate of the exhaust gas and the like, it is difficult to detect the state of the filter such as the amount of accumulated particulate matter with high accuracy.
  • the object of the present disclosure is to provide a filter state detection device that detects the state of a filter with high accuracy.
  • the filter state detection device includes a differential pressure sensor that detects the differential pressure between the upstream and downstream filters of the filter arranged in the exhaust pipe in order to capture the particulate matter contained in the exhaust gas of the vehicle. Calculated by the calculation unit and the calculation unit that calculate the pressure ratio between the reference differential pressure on the upstream side and downstream side of the filter preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor. It is provided with a determination unit for estimating the accumulated amount of particulate matter in the filter based on the pressure ratio.
  • FIG. 1 is a diagram showing a configuration of a vehicle provided with a filter state detection device according to the first embodiment of the present disclosure.
  • FIG. 2 is a graph showing changes in the filter differential pressure detected by the differential pressure sensor.
  • FIG. 3 is a graph showing the pressure ratio between the reference differential pressure and the filter differential pressure.
  • FIG. 4 is a graph showing the change in the pressure ratio calculated each time the filter regeneration process is performed.
  • FIG. 5 is a diagram showing a configuration of a main part of the filter state detection device according to the second embodiment.
  • FIG. 1 shows a configuration of a vehicle provided with a filter state detection device according to the first embodiment of the present disclosure.
  • the vehicle has an internal combustion engine 1, an intake pipe 2, an exhaust pipe 3, an internal combustion engine control unit 4, and a purification device 5.
  • Examples of vehicles include commercial vehicles such as trucks.
  • the internal combustion engine 1 is for driving a vehicle, and is composed of, for example, a so-called 4-stroke engine that repeats four strokes of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke.
  • Examples of the internal combustion engine 1 include a diesel engine and the like.
  • the intake pipe 2 is a flow path whose tip end is connected to the intake port of the internal combustion engine 1 and supplies air sucked from the outside to the internal combustion engine 1.
  • the exhaust pipe 3 is arranged so as to extend outward from the exhaust port of the internal combustion engine 1, and is a flow path for discharging the exhaust gas discharged from the internal combustion engine 1 to the outside.
  • the internal combustion engine control unit 4 controls the internal combustion engine 1 and is connected to the internal combustion engine 1 and the regeneration processing control unit of the purification device 5, respectively.
  • the internal combustion engine control unit 4 controls, for example, the flow rates of air and exhaust gas flowing through the intake pipe 2 and the exhaust pipe 3, the engine speed, the injection of fuel, and the like.
  • the purification device 5 includes an oxidation catalyst 6, a filter 7, temperature sensors 8a and 8b, a valve 9, an injector 10, a regeneration processing control unit 11, and a filter state detection device 12.
  • the oxidation catalyst 6 is arranged in the exhaust pipe 3 and oxidizes and purifies unburned fuel such as hydrocarbons and carbon monoxide contained in the exhaust gas. Further, the oxidation catalyst 6 oxidizes the fuel injected from the injector 10 and heats the exhaust gas to a high temperature by the reaction heat.
  • the oxidation catalyst 6 can be composed of, for example, platinum and cerium oxide.
  • the filter 7 is arranged on the downstream side of the oxidation catalyst 6 in the exhaust pipe 3 and captures particulate matter such as soot components and ash.
  • the filter 7 can be composed of, for example, a so-called wall flow type in which cells made of porous ceramics such as cordierite and silicon carbide are arranged so that inlets and outlets are alternately closed.
  • the temperature sensors 8a and 8b detect the temperature of the exhaust gas flowing in the exhaust pipe 3, and are arranged so as to sandwich the oxidation catalyst 6 in the exhaust pipe 3.
  • the valve 9 is a so-called exhaust throttle valve that is connected to the regeneration processing control unit 11 and adjusts the opening degree of the exhaust pipe 3 under the control of the regeneration processing control unit 11.
  • the valve 9 can be configured to adjust the opening degree of the exhaust pipe 3, for example, by rotating around a rotation axis orthogonal to the exhaust pipe 3. Further, the valve 9 can be arranged between the internal combustion engine 1 and the temperature sensor 8a in the vicinity of the internal combustion engine 1, specifically, on the downstream side of the turbocharger (not shown).
  • the injector 10 is connected to the regeneration processing control unit 11 and injects fuel into the exhaust pipe 3 under the control of the regeneration processing control unit 11.
  • the injector 10 is arranged on the downstream side of the valve 9 in the exhaust pipe 3.
  • the regeneration processing control unit 11 is connected to the internal combustion engine control unit 4, the temperature sensor 8a, the temperature sensor 8b, and the differential pressure sensor 13 of the filter state detection device 12.
  • the reproduction processing control unit 11 determines the timing to start the reproduction processing of the filter 7 based on the filter differential pressure on the upstream side and the downstream side of the filter 7 input from the differential pressure sensor 13 of the filter state detection device 12.
  • the injector 10 is controlled to inject fuel into the exhaust pipe 3 and react with the oxidation catalyst 6 to heat the exhaust gas.
  • the regeneration processing control unit 11 controls the valve 9 to close the exhaust pipe 3 to increase the load of the internal combustion engine 1 and raise the temperature of the exhaust gas.
  • the regeneration processing control unit 11 controls the regeneration processing of the filter 7 based on the temperature information input from the temperature sensors 8a and 8b.
  • a reference differential pressure between the upstream side and the downstream side of the filter 7 according to the flow rate of the exhaust gas is preset. Further, the flow rate of the exhaust gas is sequentially input to the regeneration processing control unit 11 from the internal combustion engine control unit 4. The regeneration processing control unit 11 sequentially calculates the reference differential pressure of the filter 7 based on the flow rate of the exhaust gas input from the internal combustion engine control unit 4.
  • the reference differential pressure of the filter 7 can be set, for example, by creating a map showing the change of the differential pressure of the filter 7 with respect to the flow rate of the exhaust gas by simulation or the like.
  • the filter state detection device 12 includes a differential pressure sensor 13, a calculation unit 14, a determination unit 15, a notification unit 16, a communication unit 17, and an information providing unit 18.
  • the differential pressure sensor 13 is connected to the determination unit 15 via the calculation unit 14.
  • the calculation unit 14 is also connected to the reproduction processing control unit 11.
  • the determination unit 15 is connected to the notification unit 16 and the communication unit 17, respectively, and the communication unit 17 is connected to the information providing unit 18 by wireless communication.
  • the differential pressure sensor 13 is arranged in the exhaust pipe 3 and detects the filter differential pressure on the upstream side and the downstream side of the filter 7.
  • the calculation unit 14 calculates the pressure ratio between the reference differential pressure of the filter 7 calculated by the reproduction processing control unit 11 and the filter differential pressure of the filter 7 detected by the differential pressure sensor 13.
  • the determination unit 15 estimates the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. Then, the determination unit 15 determines the maintenance time of the filter 7 based on the estimated amount of ash deposited.
  • the notification unit 16 notifies the vehicle user of the determination result determined by the determination unit 15.
  • the notification unit 16 can be composed of, for example, a display unit and a speaker.
  • the communication unit 17 wirelessly transmits the determination result determined by the determination unit 15 to the information providing unit 18.
  • the information providing unit 18 provides the vehicle user with the maintenance time of the filter based on the determination result transmitted from the communication unit 17.
  • the information providing unit 18 can be provided in, for example, a vehicle management company, a vehicle maintenance site, a dealer, or the like.
  • the functions of the internal combustion engine control unit 4, the reproduction processing control unit 11, the calculation unit 14, and the determination unit 15 can also be realized by a computer program.
  • a computer reading device reads the program from a recording medium in which a program for realizing the functions of the internal combustion engine control unit 4, the reproduction processing control unit 11, the calculation unit 14, and the determination unit 15 is recorded, and stores the program in the storage device. Let me. Then, the CPU copies the program stored in the storage device to the RAM, sequentially reads the instructions included in the program from the RAM, and executes the program, whereby the internal combustion engine control unit 4, the reproduction processing control unit 11, and the calculation unit 14 are executed. And the function of the determination unit 15 can be realized.
  • the differential pressure sensor 13 sequentially detects the filter differential pressure of the filter 7. Then, the regeneration processing control unit 11 determines the start timing of the regeneration processing for burning and removing the particulate matter deposited on the filter 7 based on the filter differential pressure detected by the differential pressure sensor 13.
  • the reproduction processing control unit 11 can determine that the reproduction processing of the filter 7 is started when the filter differential pressure detected by the differential pressure sensor 13 exceeds a predetermined threshold value for a certain period of time.
  • the injector 10 When the regeneration processing control unit 11 determines that the regeneration processing of the filter 7 is started, the injector 10 is controlled based on the temperature detected by the temperature sensors 8a and 8b, and fuel, for example, light oil is injected into the exhaust pipe 3. As a result, the oxidation catalyst 6 oxidizes the fuel injected from the injector 10, and the heat of reaction thereof heats the exhaust gas to a high temperature. Further, the regeneration processing control unit 11 controls the valve 9 so as to close the exhaust pipe 3 to raise the temperature of the exhaust gas.
  • the exhaust gas heated to a high temperature passes through the filter 7 to burn the soot component of the particulate matter deposited on the filter 7, and the filter 7 is regenerated. Then, when the regeneration process of the filter 7 is completed, the regeneration process control unit 11 controls the valve 9 so as to stop the injector 10 and open the exhaust pipe 3.
  • the calculation unit 14 acquires the filter differential pressure of the filter 7 detected by the differential pressure sensor 13 immediately after the regeneration process of the filter 7. For example, as shown in FIG. 2, the calculation unit 14 sequentially acquires the filter differential pressure detected by the differential pressure sensor 13 over a predetermined time from the time S1 to the time S2 when the reproduction process of the filter 7 is completed at regular intervals. ..
  • the calculation unit 14 acquires the reference differential pressure of the filter 7 calculated by the reproduction processing control unit 11.
  • a map showing the change in the differential pressure of the filter 7 with respect to the flow rate of the exhaust gas is preset in the regeneration processing control unit 11.
  • the regeneration processing control unit 11 sequentially acquires the flow rate of the exhaust gas that changes according to the drive of the internal combustion engine 1 from the internal combustion engine control unit 4.
  • the regeneration processing control unit 11 sequentially calculates the reference differential pressure on the upstream side and the downstream side of the filter 7 according to the flow rate of the exhaust gas acquired from the internal combustion engine control unit 4 based on the preset map.
  • the regeneration processing control unit 11 can easily calculate the reference differential pressure of the filter 7 by setting the change of the differential pressure of the filter 7 with respect to the flow rate of the exhaust gas as a map.
  • the reproduction processing control unit 11 outputs the calculated reference differential pressure of the filter 7 to the calculation unit 14.
  • the calculation unit 14 sequentially inputs the filter differential pressure of the filter 7 detected by the differential pressure sensor 13 and the reference differential pressure of the filter 7 calculated by the reproduction processing control unit 11. Then, the calculation unit 14 determines the pressure ratio between the filter differential pressure of the filter 7 detected by the differential pressure sensor 13 and the reference differential pressure of the filter 7 according to the flow rate of the exhaust gas when the filter differential pressure is detected. calculate. For example, as shown in FIG. 3, the calculation unit 14 sequentially calculates the pressure ratio between the filter differential pressure detected by the differential pressure sensor 13 and the reference differential pressure corresponding to the filter differential pressure over a predetermined time. Then, the calculation unit 14 can calculate the pressure ratio immediately after the regeneration process of the filter 7 by approximating the calculated plurality of pressure ratios with the approximate expression E. The calculation unit 14 outputs the calculated pressure ratio to the determination unit 15.
  • the calculation unit 14 is not limited to approximating a plurality of pressure ratios with the approximation formula E, and calculates the pressure ratio immediately after the regeneration process of the filter 7, for example, by averaging the plurality of pressure ratios. May be good.
  • the determination unit 15 estimates the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. For example, it is assumed that the map stored in the regeneration processing control unit 11 is preset based on the filter 7 in which a predetermined amount of particulate matter is deposited, for example, the particulate matter is deposited as a whole. In this case, the determination unit 15 estimates that the closer the pressure ratio is to 1, the larger the amount of ash deposited, and the closer the pressure ratio is to zero, the smaller the amount of ash deposited.
  • the filter differential pressure detected by the differential pressure sensor 13 greatly varies depending on the detection time depending on the flow rate of the exhaust gas and the like. Specifically, as calculated from Bernoulli's theorem, the filter differential pressure is proportional to the square of the exhaust gas flow rate. For example, when the exhaust gas flow rate increases 1.2 times, the filter differential pressure increases 1.44 times. Will be.
  • the amount of ash deposited in the filter 7 has been calculated directly from the filter differential pressure detected by the differential pressure sensor 13. Therefore, the calculated value fluctuates greatly according to the flow rate of the exhaust gas, and there is a possibility that the amount of ash deposited cannot be estimated accurately.
  • the filter differential pressure of the filter 7 is detected while the vehicle is stopped and the accelerator operation amount is kept constant, in order to estimate the amount of ash deposited. It took a lot of effort.
  • the determination unit 15 calculates the amount of ash deposited in the filter 7 based on the pressure ratio between the preset reference differential pressure of the filter 7 and the filter differential pressure detected by the differential pressure sensor 13. do.
  • this method for example, when the flow rate of the exhaust gas increases 1.2 times, both the filter differential pressure and the reference differential pressure increase 1.44 times, so that the pressure ratio does not depend on the exhaust gas flow rate. It becomes constant. As a result, it is possible to suppress the calculated ash deposit amount from fluctuating according to the flow rate of the exhaust gas, and to detect the state of the filter 7 with high accuracy.
  • the determination unit 15 can calculate the amount of ash deposited while traveling the vehicle. Therefore, for example, it is not necessary to maintain a constant amount of accelerator operation, and the amount of ash deposited can be easily calculated.
  • the calculation unit 14 calculates the pressure ratio based on the plurality of filter differential pressures sequentially detected by the differential pressure sensor 13 over a predetermined time. Therefore, the determination unit 15 can accurately estimate the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. At this time, it is preferable that the calculation unit 14 sequentially acquires the filter differential pressure within about 1 hour after the regeneration process of the filter 7 is completed.
  • the calculation unit 14 calculates the pressure ratio based on the filter differential pressure when the internal combustion engine 1 is operating near the steady state among the plurality of filter differential pressures sequentially detected by the differential pressure sensor 13 over a predetermined time. It is preferable to calculate. For example, the calculation unit 14 acquires the operation information of the internal combustion engine 1 from the internal combustion engine control unit 4, and obtains the period during which the internal combustion engine 1 is operating near the steady state based on the operation information. Then, the calculation unit 14 calculates the pressure ratio based on the filter differential pressure detected by the differential pressure sensor 13 during that period. As a result, the calculation unit 14 can accurately calculate the pressure ratio.
  • the calculation unit 14 has a reference differential pressure set in advance based on the filter 7 in which particulate matter is deposited on the whole, and a filter differential pressure detected by the differential pressure sensor 13 immediately after the regeneration process of the filter 7, that is, The pressure ratio with the filter differential pressure of the filter 7 in a state where most of the soot component is removed and only ash is deposited is calculated. Therefore, the determination unit 15 can accurately estimate the amount of ash deposited in the filter 7 based on this pressure ratio.
  • the calculation unit 14 determines the reference differential pressure of the preset filter 7 and the filter difference detected by the differential pressure sensor 13 each time the reproduction process of the filter 7 is performed. Calculate the pressure ratio to the pressure. Subsequently, the determination unit 15 estimates the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. Then, the determination unit 15 determines the maintenance time of the filter 7 based on the estimated amount of ash deposited.
  • the determination unit 15 is preset with a threshold value T of a pressure ratio that requires maintenance of the filter 7.
  • the determination unit 15 estimates that the amount of ash deposited on the filter 7 increases as the pressure ratio approaches the threshold value T. Then, when the pressure ratio exceeds the threshold value T, the determination unit 15 estimates that a predetermined amount of ash has accumulated on the filter 7, and determines that maintenance of the filter 7 is necessary.
  • the determination unit 15 outputs the determination result to the notification unit 16 and outputs the determination result to the information providing unit 18 via the communication unit 17. Then, the notification unit 16 notifies the vehicle user by displaying the maintenance time of the filter 7 based on the determination result of the determination unit 15. Further, the information providing unit 18 provides the vehicle user with the maintenance time of the filter 7 based on the determination result of the determination unit 15. By providing the maintenance period of the filter 7 in this way, the user of the vehicle can efficiently perform maintenance such as cleaning and replacement of the filter 7.
  • the determination unit 15 can determine that the device other than the filter 7 is defective.
  • the determination unit 15 can determine that the exhaust gas is not heated to a high temperature due to a malfunction of devices such as the internal combustion engine 1, the oxidation catalyst 6, the valve 9, and the injector 10.
  • the determination unit 15 is based on the pressure ratio between the reference differential pressure of the filter 7 preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor 13. Since the amount of ash deposited on the filter 7 is estimated, the state of the filter 7 can be detected with high accuracy.
  • Embodiment 2 of the present disclosure will be described.
  • the differences from the first embodiment will be mainly described, and the common reference numerals will be used for the common points with the first embodiment, and detailed description thereof will be omitted.
  • the determination unit 15 estimates the amount of ash deposited on the filter 7, but the present invention is not limited to this as long as the amount of particulate matter deposited on the filter 7 can be estimated.
  • the determination unit 21 can be arranged in place of the determination unit 15 of the first embodiment, and the reproduction processing control unit 22 can be arranged in place of the reproduction processing control unit 11.
  • the determination unit 21 is connected to the reproduction processing control unit 22.
  • the determination unit 21 estimates the amount of particulate matter including soot components and ash deposited on the filter 7 based on the pressure ratio calculated by the calculation unit 14.
  • the regeneration processing control unit 22 determines the timing to start the regeneration processing of the filter 7 based on the accumulated amount of particulate matter estimated by the determination unit 21.
  • the calculation unit 14 acquires the filter differential pressure detected by the differential pressure sensor 13 while the internal combustion engine 1 is being driven, and the filter 7 is set in advance according to the flow rate of the exhaust gas.
  • the pressure ratio between the reference differential pressure and the filter differential pressure detected by the differential pressure sensor 13 is sequentially calculated.
  • the calculation unit 14 outputs the calculated pressure ratio to the determination unit 21.
  • the determination unit 21 estimates the amount of particulate matter deposited on the filter 7 based on the pressure ratio calculated by the calculation unit 14.
  • the map stored in the regeneration processing control unit 22 is preset based on the filter 7 in which the particulate matter is deposited as a whole, as in the first embodiment. In this case, the determination unit 21 estimates that the closer the pressure ratio is to 1, the larger the amount of particulate matter deposited, and the closer the pressure ratio is to zero, the smaller the amount of particulate matter deposited.
  • a threshold value of the pressure ratio for executing the regeneration process of the filter 7 is preset in the determination unit 21, and when the pressure ratio exceeds the threshold value, it is estimated that a predetermined amount of particulate matter is deposited on the filter 7. do.
  • the determination unit 21 outputs the accumulated amount of the particulate matter to the regeneration processing control unit 22.
  • the regeneration processing control unit 22 determines that the regeneration processing of the filter 7 is started.
  • the reproduction processing control unit 22 has determined the timing to start the reproduction processing of the filter 7 based on the filter differential pressure detected by the differential pressure sensor 13. For this reason, the timing for starting the regeneration process of the filter 7 varies depending on the flow rate of the exhaust gas, and it is difficult to start the regeneration process of the filter when particulate matter is deposited on the filter 7 with a constant deposition amount. there were.
  • the determination unit 21 filters based on the pressure ratio between the reference differential pressure of the filter 7 preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor 13. Estimate the amount of particulate matter deposited in 7. Then, the regeneration processing control unit 22 determines the timing to start the regeneration processing of the filter 7 based on the accumulated amount of the particulate matter in the filter 7 estimated by the determination unit 21. Therefore, the filter 7 can be regenerated at the timing when a certain amount of particulate matter is deposited on the filter 7, and the regenerating process of the filter 7 can be performed at an appropriate timing.
  • the injector 10 and the valve 9 are controlled to heat the exhaust gas to a high temperature.
  • the soot component of the particulate matter deposited on the filter 7 is burned, and the filter 7 is regenerated.
  • the determination unit 21 is based on the pressure ratio between the reference differential pressure of the filter 7 preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor 13. , Estimate the amount of particulate matter deposited on the filter 7. Therefore, the regeneration processing control unit 22 can appropriately determine the timing at which the regeneration processing of the filter 7 is started based on the accumulated amount of the particulate matter in the filter 7 estimated by the determination unit 21.
  • the calculation unit 14 calculates the pressure ratio based on the plurality of filter differential pressures detected by the differential pressure sensor 13 over a predetermined time, but the pressure ratio is calculated as one filter differential pressure.
  • the pressure ratio may be calculated based on this.
  • the calculation unit 14 sets the reference differential pressure in advance based on the filter 7 in which the particulate matter is deposited on the whole, but the reference differential pressure is set according to the flow rate of the exhaust gas. It is only necessary to be able to set, and it is not limited to this.
  • the calculation unit 14 can set the reference differential pressure based on the filter 7 in which the particulate matter is not deposited.
  • the calculation unit 14 and the determination unit 15 are arranged in the vehicle, but they can also be arranged outside to transmit / receive information via a communication line.
  • the regeneration processing control unit controls the injector 10 to heat the exhaust gas to a high temperature, but the reaction heat of the oxidation catalyst 6 may heat the exhaust gas to a high temperature. If possible, it is not limited to the injector 10.
  • the regeneration processing control unit can control the multi-stage injection of the internal combustion engine 1 to react the oxidation catalyst 6.
  • the filter state detection device can be used for a device in which a filter for capturing particulate matter contained in exhaust gas is arranged in an exhaust pipe.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Processes For Solid Components From Exhaust (AREA)

Abstract

Provided is a filter state detection device which detects the state of a filter with high accuracy. This filter state detection device comprises: a differential pressure sensor which detects a filter differential pressure between the upstream side and the downstream side of a filter disposed in an exhaust pipe in order to capture particulate matter contained in exhaust gas of a vehicle; a calculation unit which calculates a pressure ratio of the filter differential pressure detected by the differential pressure sensor to a reference differential pressure between the upstream side and the downstream side of the filter which is pre-set in accordance with the flow rate of the exhaust gas; and a determination unit which estimates the accumulated amount of particulate matter in the filter on the basis of the pressure ratio calculated by the calculation unit.

Description

フィルタ状態検知装置Filter state detector
　本開示は、フィルタ状態検知装置に関する。 This disclosure relates to a filter state detection device.
　従来から、例えば商用車などの車両において、排気ガスに含まれる粒子状物質（Ｐａｒｔｉｃｕｌａｔｅ　Ｍａｔｔｅｒ）を捕捉するフィルタが排気管に配置されており、このフィルタの状態を検知するフィルタ状態検知装置が実用化されている。フィルタ状態検知装置の一例として、フィルタの上流側と下流側のフィルタ差圧に基づいて、フィルタにおける粒子状物質の堆積量を算出する技術が知られている。 Conventionally, in vehicles such as commercial vehicles, a filter that captures particulate matter (Particulate Matter) contained in exhaust gas has been arranged in the exhaust pipe, and a filter state detection device that detects the state of this filter has been put into practical use. Has been done. As an example of the filter state detection device, there is known a technique of calculating the deposited amount of particulate matter in the filter based on the filter differential pressure on the upstream side and the downstream side of the filter.
　例えば、フィルタの再生処理直後に使用すれば、フィルタ状態検知装置は、フィルタ差圧に基づいて、粒子状物質のうちアッシュの堆積量を算出することができる。このアッシュは、エンジンオイルおよび燃料添加物などに含まれる金属酸化物および硫酸塩などに起因する不燃性物質であり、高温により粒子状物質を燃焼させるフィルタの再生処理で除去することが困難となる。このため、アッシュの堆積量を算出することにより、例えば、フィルタの洗浄および交換などのメンテナンスの時期を判定することができる。ここで、フィルタのメンテナンス時期を正確に判定することが求められている。 For example, if it is used immediately after the filter regeneration process, the filter state detection device can calculate the amount of ash deposited among the particulate matter based on the filter differential pressure. This ash is a nonflammable substance caused by metal oxides and sulfates contained in engine oil and fuel additives, and it is difficult to remove it by the regeneration process of a filter that burns particulate matter at high temperature. .. Therefore, by calculating the amount of ash deposited, it is possible to determine the timing of maintenance such as cleaning and replacement of the filter, for example. Here, it is required to accurately determine the maintenance time of the filter.
　そこで、フィルタのメンテナンス時期を正確に判定する技術として、例えば、特許文献１には、ＤＰＦの故障の有無の判定精度を向上したＤＰＦの再生処理制御方法が開示されている。この再生処理制御方法は、粒子状物質の過堆積を判定する閾値をアッシュの堆積量に基づいて変化させるため、アッシュの堆積量を考慮してフィルタのメンテナンス時期を正確に判定することができる。 Therefore, as a technique for accurately determining the maintenance time of the filter, for example, Patent Document 1 discloses a DPF regeneration processing control method in which the accuracy of determining the presence or absence of a DPF failure is improved. In this regeneration processing control method, the threshold value for determining the over-deposition of particulate matter is changed based on the amount of ash deposited, so that the maintenance time of the filter can be accurately determined in consideration of the amount of ash deposited.
日本国特開２００７－２７０６９５号公報Japanese Patent Application Laid-Open No. 2007-270695
　しかしながら、特許文献１の再生処理制御方法は、フィルタの上流側と下流側のフィルタ差圧のみに基づいて、フィルタにおける粒子状物質の堆積量を判定する。フィルタ差圧は、排気ガスの流量などに応じて大きく変化するため、粒子状物質の堆積量などのフィルタの状態を高精度に検知することは困難であった。 However, the regeneration processing control method of Patent Document 1 determines the amount of particulate matter deposited on the filter based only on the filter differential pressure on the upstream side and the downstream side of the filter. Since the filter differential pressure changes greatly depending on the flow rate of the exhaust gas and the like, it is difficult to detect the state of the filter such as the amount of accumulated particulate matter with high accuracy.
　本開示は、フィルタの状態を高精度に検知するフィルタ状態検知装置を提供することを目的とする。 The object of the present disclosure is to provide a filter state detection device that detects the state of a filter with high accuracy.
　本開示に係るフィルタ状態検知装置は、車両の排気ガスに含まれる粒子状物質を捕捉するために排気管に配置されたフィルタの上流側と下流側のフィルタ差圧を検出する差圧センサと、排気ガスの流量に応じて予め設定されたフィルタの上流側と下流側の基準差圧と、差圧センサで検出されたフィルタ差圧との圧力比を算出する算出部と、算出部で算出された圧力比に基づいて、フィルタにおける粒子状物質の堆積量を推定する判定部とを備えるものである。 The filter state detection device according to the present disclosure includes a differential pressure sensor that detects the differential pressure between the upstream and downstream filters of the filter arranged in the exhaust pipe in order to capture the particulate matter contained in the exhaust gas of the vehicle. Calculated by the calculation unit and the calculation unit that calculate the pressure ratio between the reference differential pressure on the upstream side and downstream side of the filter preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor. It is provided with a determination unit for estimating the accumulated amount of particulate matter in the filter based on the pressure ratio.
　本開示によれば、フィルタの状態を高精度に検知することが可能となる。 According to the present disclosure, it is possible to detect the state of the filter with high accuracy.
図１は、本開示の実施の形態１に係るフィルタ状態検知装置を備えた車両の構成を示す図である。FIG. 1 is a diagram showing a configuration of a vehicle provided with a filter state detection device according to the first embodiment of the present disclosure. 図２は、差圧センサで検出されるフィルタ差圧の変化を示すグラフである。FIG. 2 is a graph showing changes in the filter differential pressure detected by the differential pressure sensor. 図３は、基準差圧とフィルタ差圧との圧力比を示すグラフである。FIG. 3 is a graph showing the pressure ratio between the reference differential pressure and the filter differential pressure. 図４は、フィルタの再生処理が実施される度に算出された圧力比の変化を示すグラフである。FIG. 4 is a graph showing the change in the pressure ratio calculated each time the filter regeneration process is performed. 図５は、実施の形態２に係るフィルタ状態検知装置の要部の構成を示す図である。FIG. 5 is a diagram showing a configuration of a main part of the filter state detection device according to the second embodiment.
　以下、本開示に係る実施の形態を添付図面に基づいて説明する。 Hereinafter, embodiments according to the present disclosure will be described with reference to the attached drawings.
（実施の形態１）
　図１に、本開示の実施の形態１に係るフィルタ状態検知装置を備えた車両の構成を示す。車両は、内燃機関１と、吸気管２と、排気管３と、内燃機関制御部４と、浄化装置５とを有する。なお、車両としては、例えば、トラックなどの商用車が挙げられる。 (Embodiment 1)
FIG. 1 shows a configuration of a vehicle provided with a filter state detection device according to the first embodiment of the present disclosure. The vehicle has an internal combustion engine 1, an intake pipe 2, an exhaust pipe 3, an internal combustion engine control unit 4, and a purification device 5. Examples of vehicles include commercial vehicles such as trucks.
　内燃機関１は、車両を駆動するためのもので、例えば、吸気行程、圧縮行程、膨張行程および排気行程の４つの行程を繰り返す、いわゆる４ストローク機関から構成されている。内燃機関１としては、例えば、ディーゼルエンジンなどが挙げられる。 The internal combustion engine 1 is for driving a vehicle, and is composed of, for example, a so-called 4-stroke engine that repeats four strokes of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. Examples of the internal combustion engine 1 include a diesel engine and the like.
　吸気管２は、先端部が内燃機関１の吸気口に接続され、外部から吸入された空気を内燃機関１に供給する流路である。
　排気管３は、内燃機関１の排気口から外部に延びるように配置され、内燃機関１から排出される排気ガスを外部に排出する流路である。 The intake pipe 2 is a flow path whose tip end is connected to the intake port of the internal combustion engine 1 and supplies air sucked from the outside to the internal combustion engine 1.
The exhaust pipe 3 is arranged so as to extend outward from the exhaust port of the internal combustion engine 1, and is a flow path for discharging the exhaust gas discharged from the internal combustion engine 1 to the outside.
　内燃機関制御部４は、内燃機関１を制御するもので、内燃機関１および浄化装置５の再生処理制御部にそれぞれ接続されている。内燃機関制御部４は、例えば、吸気管２および排気管３を流通する空気および排気ガスの流量、エンジン回転数および燃料の噴射などを制御する。 The internal combustion engine control unit 4 controls the internal combustion engine 1 and is connected to the internal combustion engine 1 and the regeneration processing control unit of the purification device 5, respectively. The internal combustion engine control unit 4 controls, for example, the flow rates of air and exhaust gas flowing through the intake pipe 2 and the exhaust pipe 3, the engine speed, the injection of fuel, and the like.
　浄化装置５は、酸化触媒６と、フィルタ７と、温度センサ８ａおよび８ｂと、バルブ９と、インジェクタ１０と、再生処理制御部１１と、フィルタ状態検知装置１２とを有する。 The purification device 5 includes an oxidation catalyst 6, a filter 7, temperature sensors 8a and 8b, a valve 9, an injector 10, a regeneration processing control unit 11, and a filter state detection device 12.
　酸化触媒６は、排気管３内に配置され、排気ガスに含まれる炭化水素および一酸化炭素などの未燃焼燃料を酸化して浄化する。また、酸化触媒６は、インジェクタ１０から噴射される燃料を酸化することにより、その反応熱で排気ガスを高温に加熱する。酸化触媒６は、例えば、白金および酸化セリウムなどから構成することができる。 The oxidation catalyst 6 is arranged in the exhaust pipe 3 and oxidizes and purifies unburned fuel such as hydrocarbons and carbon monoxide contained in the exhaust gas. Further, the oxidation catalyst 6 oxidizes the fuel injected from the injector 10 and heats the exhaust gas to a high temperature by the reaction heat. The oxidation catalyst 6 can be composed of, for example, platinum and cerium oxide.
　フィルタ７は、排気管３内において酸化触媒６の下流側に配置され、煤成分およびアッシュなどの粒子状物質を捕捉する。フィルタ７は、例えば、コーディエライトおよび炭化ケイ素などの多孔質セラミックから形成されたセルを、入口と出口が交互に閉鎖するように並べた、いわゆるウォールフロー型から構成することができる。 The filter 7 is arranged on the downstream side of the oxidation catalyst 6 in the exhaust pipe 3 and captures particulate matter such as soot components and ash. The filter 7 can be composed of, for example, a so-called wall flow type in which cells made of porous ceramics such as cordierite and silicon carbide are arranged so that inlets and outlets are alternately closed.
　温度センサ８ａおよび８ｂは、排気管３内を流通する排気ガスの温度を検出するもので、排気管３において酸化触媒６を挟むように配置されている。 The temperature sensors 8a and 8b detect the temperature of the exhaust gas flowing in the exhaust pipe 3, and are arranged so as to sandwich the oxidation catalyst 6 in the exhaust pipe 3.
　バルブ９は、再生処理制御部１１に接続され、再生処理制御部１１の制御の下、排気管３の開度を調整する、いわゆるエグゾーストスロットルバルブである。バルブ９は、例えば、排気管３に直交する回転軸の周りに回転することで排気管３の開度を調整するように構成することができる。また、バルブ９は、内燃機関１と温度センサ８ａとの間において内燃機関１の近傍、具体的には図示しないターボチャージャーの下流側に配置することができる。 The valve 9 is a so-called exhaust throttle valve that is connected to the regeneration processing control unit 11 and adjusts the opening degree of the exhaust pipe 3 under the control of the regeneration processing control unit 11. The valve 9 can be configured to adjust the opening degree of the exhaust pipe 3, for example, by rotating around a rotation axis orthogonal to the exhaust pipe 3. Further, the valve 9 can be arranged between the internal combustion engine 1 and the temperature sensor 8a in the vicinity of the internal combustion engine 1, specifically, on the downstream side of the turbocharger (not shown).
　インジェクタ１０は、再生処理制御部１１に接続され、再生処理制御部１１の制御の下、排気管３内に燃料を噴射する。インジェクタ１０は、排気管３においてバルブ９の下流側に配置されている。 The injector 10 is connected to the regeneration processing control unit 11 and injects fuel into the exhaust pipe 3 under the control of the regeneration processing control unit 11. The injector 10 is arranged on the downstream side of the valve 9 in the exhaust pipe 3.
　再生処理制御部１１は、内燃機関制御部４、温度センサ８ａ、温度センサ８ｂおよびフィルタ状態検知装置１２の差圧センサ１３に接続されている。再生処理制御部１１は、フィルタ状態検知装置１２の差圧センサ１３から入力されるフィルタ７の上流側と下流側のフィルタ差圧に基づいて、フィルタ７の再生処理を開始するタイミングを判定する。再生処理制御部１１は、再生処理を開始すると判定した場合には、インジェクタ１０を制御して排気管３内に燃料を噴射し、酸化触媒６を反応させて排気ガスを加熱させる。また、再生処理制御部１１は、バルブ９を制御して排気管３を閉じることにより内燃機関１の負荷を増やし、排気ガスの温度を上昇させる。このとき、再生処理制御部１１は、温度センサ８ａおよび８ｂから入力される温度情報に基づいてフィルタ７の再生処理を制御する。 The regeneration processing control unit 11 is connected to the internal combustion engine control unit 4, the temperature sensor 8a, the temperature sensor 8b, and the differential pressure sensor 13 of the filter state detection device 12. The reproduction processing control unit 11 determines the timing to start the reproduction processing of the filter 7 based on the filter differential pressure on the upstream side and the downstream side of the filter 7 input from the differential pressure sensor 13 of the filter state detection device 12. When the regeneration processing control unit 11 determines that the regeneration processing is to be started, the injector 10 is controlled to inject fuel into the exhaust pipe 3 and react with the oxidation catalyst 6 to heat the exhaust gas. Further, the regeneration processing control unit 11 controls the valve 9 to close the exhaust pipe 3 to increase the load of the internal combustion engine 1 and raise the temperature of the exhaust gas. At this time, the regeneration processing control unit 11 controls the regeneration processing of the filter 7 based on the temperature information input from the temperature sensors 8a and 8b.
　また、再生処理制御部１１には、フィルタ７の再生処理を制御するために、排気ガスの流量に応じたフィルタ７の上流側と下流側の基準差圧が予め設定されている。また、再生処理制御部１１には、内燃機関制御部４から排気ガスの流量が順次入力されている。再生処理制御部１１は、内燃機関制御部４から入力される排気ガスの流量に基づいて、フィルタ７の基準差圧を順次算出する。
　なお、フィルタ７の基準差圧は、例えば、排気ガスの流量に対するフィルタ７の差圧の変化を示すマップをシミュレーションなどにより作成して設定することができる。 Further, in the regeneration processing control unit 11, in order to control the regeneration processing of the filter 7, a reference differential pressure between the upstream side and the downstream side of the filter 7 according to the flow rate of the exhaust gas is preset. Further, the flow rate of the exhaust gas is sequentially input to the regeneration processing control unit 11 from the internal combustion engine control unit 4. The regeneration processing control unit 11 sequentially calculates the reference differential pressure of the filter 7 based on the flow rate of the exhaust gas input from the internal combustion engine control unit 4.
The reference differential pressure of the filter 7 can be set, for example, by creating a map showing the change of the differential pressure of the filter 7 with respect to the flow rate of the exhaust gas by simulation or the like.
　フィルタ状態検知装置１２は、差圧センサ１３と、算出部１４と、判定部１５と、報知部１６と、通信部１７と、情報提供部１８とを有する。差圧センサ１３が、算出部１４を介して判定部１５に接続されている。また、算出部１４は、再生処理制御部１１にも接続されている。そして、判定部１５が、報知部１６および通信部１７にそれぞれ接続され、通信部１７が無線通信により情報提供部１８に接続されている。 The filter state detection device 12 includes a differential pressure sensor 13, a calculation unit 14, a determination unit 15, a notification unit 16, a communication unit 17, and an information providing unit 18. The differential pressure sensor 13 is connected to the determination unit 15 via the calculation unit 14. The calculation unit 14 is also connected to the reproduction processing control unit 11. The determination unit 15 is connected to the notification unit 16 and the communication unit 17, respectively, and the communication unit 17 is connected to the information providing unit 18 by wireless communication.
　差圧センサ１３は、排気管３に配置され、フィルタ７の上流側と下流側のフィルタ差圧を検出する。 The differential pressure sensor 13 is arranged in the exhaust pipe 3 and detects the filter differential pressure on the upstream side and the downstream side of the filter 7.
　算出部１４は、再生処理制御部１１で算出されたフィルタ７の基準差圧と、差圧センサ１３で検出されたフィルタ７のフィルタ差圧との圧力比を算出する。 The calculation unit 14 calculates the pressure ratio between the reference differential pressure of the filter 7 calculated by the reproduction processing control unit 11 and the filter differential pressure of the filter 7 detected by the differential pressure sensor 13.
　判定部１５は、算出部１４で算出された圧力比に基づいて、フィルタ７におけるアッシュの堆積量を推定する。そして、判定部１５は、推定されたアッシュの堆積量に基づいてフィルタ７のメンテナンス時期を判定する。 The determination unit 15 estimates the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. Then, the determination unit 15 determines the maintenance time of the filter 7 based on the estimated amount of ash deposited.
　報知部１６は、判定部１５で判定された判定結果を車両の使用者に報知する。報知部１６は、例えば、表示部およびスピーカーなどから構成することができる。 The notification unit 16 notifies the vehicle user of the determination result determined by the determination unit 15. The notification unit 16 can be composed of, for example, a display unit and a speaker.
　通信部１７は、判定部１５で判定された判定結果を情報提供部１８に無線で送信する。
　情報提供部１８は、通信部１７から送信された判定結果に基づいて、フィルタのメンテナンス時期を車両の使用者に提供する。情報提供部１８は、例えば、車両の管理会社、車両の整備場およびディーラーなどに設けることができる。 The communication unit 17 wirelessly transmits the determination result determined by the determination unit 15 to the information providing unit 18.
The information providing unit 18 provides the vehicle user with the maintenance time of the filter based on the determination result transmitted from the communication unit 17. The information providing unit 18 can be provided in, for example, a vehicle management company, a vehicle maintenance site, a dealer, or the like.
　なお、内燃機関制御部４、再生処理制御部１１、算出部１４および判定部１５の機能は、コンピュータプログラムにより実現させることもできる。例えば、コンピュータの読取装置が、内燃機関制御部４、再生処理制御部１１、算出部１４および判定部１５の機能を実現するためのプログラムを記録した記録媒体からそのプログラムを読み取り、記憶装置に記憶させる。そして、ＣＰＵが、記憶装置に記憶されたプログラムをＲＡＭにコピーし、そのプログラムに含まれる命令をＲＡＭから順次読み出して実行することにより、内燃機関制御部４、再生処理制御部１１、算出部１４および判定部１５の機能を実現することができる。 The functions of the internal combustion engine control unit 4, the reproduction processing control unit 11, the calculation unit 14, and the determination unit 15 can also be realized by a computer program. For example, a computer reading device reads the program from a recording medium in which a program for realizing the functions of the internal combustion engine control unit 4, the reproduction processing control unit 11, the calculation unit 14, and the determination unit 15 is recorded, and stores the program in the storage device. Let me. Then, the CPU copies the program stored in the storage device to the RAM, sequentially reads the instructions included in the program from the RAM, and executes the program, whereby the internal combustion engine control unit 4, the reproduction processing control unit 11, and the calculation unit 14 are executed. And the function of the determination unit 15 can be realized.
　次に、本実施の形態の動作について説明する。 Next, the operation of this embodiment will be described.
　まず、図１に示すように、内燃機関制御部４が内燃機関１を制御して車両が走行されると、内燃機関１で生じた排気ガスが排気管３を流通して外部に排出される。このとき、排気ガスがフィルタ７を通過することにより、排気ガスに含まれる煤成分およびアッシュなどの粒子状物質がフィルタ７に捕捉される。 First, as shown in FIG. 1, when the internal combustion engine control unit 4 controls the internal combustion engine 1 and the vehicle is driven, the exhaust gas generated by the internal combustion engine 1 flows through the exhaust pipe 3 and is discharged to the outside. .. At this time, when the exhaust gas passes through the filter 7, the soot component and particulate matter such as ash contained in the exhaust gas are captured by the filter 7.
　このようにして、フィルタ７に粒子状物質が堆積し、その堆積量が増加するに従ってフィルタ７の上流側と下流側のフィルタ差圧が上昇することになる。そこで、差圧センサ１３が、フィルタ７のフィルタ差圧を順次検出する。そして、再生処理制御部１１が、差圧センサ１３で検出されたフィルタ差圧に基づいて、フィルタ７に堆積した粒子状物質を燃焼して除去する再生処理の開始タイミングを判定する。 In this way, particulate matter is deposited on the filter 7, and as the amount of the deposited material increases, the filter differential pressure between the upstream side and the downstream side of the filter 7 increases. Therefore, the differential pressure sensor 13 sequentially detects the filter differential pressure of the filter 7. Then, the regeneration processing control unit 11 determines the start timing of the regeneration processing for burning and removing the particulate matter deposited on the filter 7 based on the filter differential pressure detected by the differential pressure sensor 13.
　例えば、再生処理制御部１１は、差圧センサ１３で検出されるフィルタ差圧が所定の閾値を一定期間超えた場合にフィルタ７の再生処理を開始すると判定することができる。 For example, the reproduction processing control unit 11 can determine that the reproduction processing of the filter 7 is started when the filter differential pressure detected by the differential pressure sensor 13 exceeds a predetermined threshold value for a certain period of time.
　再生処理制御部１１は、フィルタ７の再生処理を開始すると判定すると、温度センサ８ａおよび８ｂで検出される温度に基づいてインジェクタ１０を制御し、排気管３内に燃料、例えば軽油を噴射させる。これにより、酸化触媒６が、インジェクタ１０から噴射された燃料を酸化し、その反応熱で排気ガスが高温に加熱される。また、再生処理制御部１１は、排気管３を閉じるようにバルブ９を制御して、排気ガスの温度を上昇させる。 When the regeneration processing control unit 11 determines that the regeneration processing of the filter 7 is started, the injector 10 is controlled based on the temperature detected by the temperature sensors 8a and 8b, and fuel, for example, light oil is injected into the exhaust pipe 3. As a result, the oxidation catalyst 6 oxidizes the fuel injected from the injector 10, and the heat of reaction thereof heats the exhaust gas to a high temperature. Further, the regeneration processing control unit 11 controls the valve 9 so as to close the exhaust pipe 3 to raise the temperature of the exhaust gas.
　このようにして、高温に加熱された排気ガスが、フィルタ７を通過することにより、フィルタ７に堆積した粒子状物質の煤成分を燃焼し、フィルタ７が再生処理される。そして、再生処理制御部１１は、フィルタ７の再生処理が完了すると、インジェクタ１０を停止すると共に排気管３を開くようにバルブ９を制御する。 In this way, the exhaust gas heated to a high temperature passes through the filter 7 to burn the soot component of the particulate matter deposited on the filter 7, and the filter 7 is regenerated. Then, when the regeneration process of the filter 7 is completed, the regeneration process control unit 11 controls the valve 9 so as to stop the injector 10 and open the exhaust pipe 3.
　このフィルタ７の再生処理によりフィルタ７に堆積した粒子状物質が除去され、再びフィルタ７で排気ガスに含まれる粒子状物質が捕捉される。ここで、フィルタ７には、粒子状物質のうち燃焼可能な煤成分だけでなく、燃焼されないアッシュも堆積している。このため、フィルタ７の再生処理により、煤成分は除去されるが、アッシュはフィルタ７にそのまま堆積されることになる。 By this regeneration process of the filter 7, the particulate matter accumulated on the filter 7 is removed, and the particulate matter contained in the exhaust gas is captured again by the filter 7. Here, not only the combustible soot component of the particulate matter but also the non-combustible ash is deposited on the filter 7. Therefore, the soot component is removed by the regeneration process of the filter 7, but the ash is deposited on the filter 7 as it is.
　そこで、フィルタ７に堆積したアッシュの堆積量を推定するために、算出部１４が、フィルタ７の再生処理の直後に差圧センサ１３で検出されたフィルタ７のフィルタ差圧を取得する。例えば、図２に示すように、算出部１４は、フィルタ７の再生処理が完了した時間Ｓ１から時間Ｓ２までの所定時間にわたって差圧センサ１３で検出されたフィルタ差圧を一定間隔で順次取得する。 Therefore, in order to estimate the amount of ash deposited on the filter 7, the calculation unit 14 acquires the filter differential pressure of the filter 7 detected by the differential pressure sensor 13 immediately after the regeneration process of the filter 7. For example, as shown in FIG. 2, the calculation unit 14 sequentially acquires the filter differential pressure detected by the differential pressure sensor 13 over a predetermined time from the time S1 to the time S2 when the reproduction process of the filter 7 is completed at regular intervals. ..
　また、算出部１４は、再生処理制御部１１で算出されるフィルタ７の基準差圧を取得する。ここで、再生処理制御部１１には、排気ガスの流量に対するフィルタ７の差圧の変化を示すマップが予め設定されている。また、再生処理制御部１１は、内燃機関１の駆動に応じて変化する排気ガスの流量を内燃機関制御部４から順次取得する。再生処理制御部１１は、予め設定されたマップに基づいて、内燃機関制御部４から取得される排気ガスの流量に応じたフィルタ７の上流側と下流側の基準差圧を順次算出する。 Further, the calculation unit 14 acquires the reference differential pressure of the filter 7 calculated by the reproduction processing control unit 11. Here, a map showing the change in the differential pressure of the filter 7 with respect to the flow rate of the exhaust gas is preset in the regeneration processing control unit 11. Further, the regeneration processing control unit 11 sequentially acquires the flow rate of the exhaust gas that changes according to the drive of the internal combustion engine 1 from the internal combustion engine control unit 4. The regeneration processing control unit 11 sequentially calculates the reference differential pressure on the upstream side and the downstream side of the filter 7 according to the flow rate of the exhaust gas acquired from the internal combustion engine control unit 4 based on the preset map.
　このように、再生処理制御部１１は、排気ガスの流量に対するフィルタ７の差圧の変化がマップとして設定されることにより、フィルタ７の基準差圧を容易に算出することができる。再生処理制御部１１は、算出されたフィルタ７の基準差圧を算出部１４に出力する。 As described above, the regeneration processing control unit 11 can easily calculate the reference differential pressure of the filter 7 by setting the change of the differential pressure of the filter 7 with respect to the flow rate of the exhaust gas as a map. The reproduction processing control unit 11 outputs the calculated reference differential pressure of the filter 7 to the calculation unit 14.
　このようにして、算出部１４は、差圧センサ１３で検出されたフィルタ７のフィルタ差圧と、再生処理制御部１１で算出されたフィルタ７の基準差圧が順次入力される。そして、算出部１４は、差圧センサ１３で検出されたフィルタ７のフィルタ差圧と、フィルタ差圧が検出されたときの排気ガスの流量に応じたフィルタ７の基準差圧との圧力比を算出する。
　例えば、図３に示すように、算出部１４は、差圧センサ１３で検出されたフィルタ差圧と、そのフィルタ差圧に対応する基準差圧との圧力比を所定時間にわたって順次算出する。そして、算出部１４は、算出された複数の圧力比を近似式Ｅで近似することにより、フィルタ７の再生処理の直後における圧力比を算出することができる。算出部１４は、算出された圧力比を判定部１５に出力する。 In this way, the calculation unit 14 sequentially inputs the filter differential pressure of the filter 7 detected by the differential pressure sensor 13 and the reference differential pressure of the filter 7 calculated by the reproduction processing control unit 11. Then, the calculation unit 14 determines the pressure ratio between the filter differential pressure of the filter 7 detected by the differential pressure sensor 13 and the reference differential pressure of the filter 7 according to the flow rate of the exhaust gas when the filter differential pressure is detected. calculate.
For example, as shown in FIG. 3, the calculation unit 14 sequentially calculates the pressure ratio between the filter differential pressure detected by the differential pressure sensor 13 and the reference differential pressure corresponding to the filter differential pressure over a predetermined time. Then, the calculation unit 14 can calculate the pressure ratio immediately after the regeneration process of the filter 7 by approximating the calculated plurality of pressure ratios with the approximate expression E. The calculation unit 14 outputs the calculated pressure ratio to the determination unit 15.
　なお、算出部１４は、複数の圧力比を近似式Ｅで近似するものに限られるものではなく、例えば複数の圧力比を平均することによりフィルタ７の再生処理の直後における圧力比を算出してもよい。 The calculation unit 14 is not limited to approximating a plurality of pressure ratios with the approximation formula E, and calculates the pressure ratio immediately after the regeneration process of the filter 7, for example, by averaging the plurality of pressure ratios. May be good.
　続いて、判定部１５が、算出部１４で算出された圧力比に基づいて、フィルタ７におけるアッシュの堆積量を推定する。例えば、再生処理制御部１１に記憶されたマップが、所定量の粒子状物質を堆積、例えば粒子状物質を全体に堆積したフィルタ７に基づいて予め設定されているものとする。この場合には、判定部１５は、圧力比が１に近づくほどアッシュの堆積量が多く、圧力比がゼロに近づくほどアッシュの堆積量が少ないと推定する。 Subsequently, the determination unit 15 estimates the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. For example, it is assumed that the map stored in the regeneration processing control unit 11 is preset based on the filter 7 in which a predetermined amount of particulate matter is deposited, for example, the particulate matter is deposited as a whole. In this case, the determination unit 15 estimates that the closer the pressure ratio is to 1, the larger the amount of ash deposited, and the closer the pressure ratio is to zero, the smaller the amount of ash deposited.
　ここで、図２に示すように、差圧センサ１３で検出されるフィルタ差圧は、排気ガスの流量などに応じて検出時間によって大きく変動する。具体的には、ベルヌーイの定理から算出されるようにフィルタ差圧は排気ガスの流量の二乗に比例し、例えば、排気ガスの流量が１．２倍になると、フィルタ差圧は１．４４倍となる。 Here, as shown in FIG. 2, the filter differential pressure detected by the differential pressure sensor 13 greatly varies depending on the detection time depending on the flow rate of the exhaust gas and the like. Specifically, as calculated from Bernoulli's theorem, the filter differential pressure is proportional to the square of the exhaust gas flow rate. For example, when the exhaust gas flow rate increases 1.2 times, the filter differential pressure increases 1.44 times. Will be.
　従来、フィルタ７におけるアッシュの堆積量は、差圧センサ１３で検出されるフィルタ差圧から直接的に算出されていた。このため、排気ガスの流量に応じて算出値が大きく変動し、アッシュの堆積量を正確に推定できないおそれがあった。この算出値の変動を抑制するために、例えば、車両を停止してアクセルの操作量を一定に維持した状態でフィルタ７のフィルタ差圧を検出するなど、アッシュの堆積量を推定するために多くの労力を要した。 Conventionally, the amount of ash deposited in the filter 7 has been calculated directly from the filter differential pressure detected by the differential pressure sensor 13. Therefore, the calculated value fluctuates greatly according to the flow rate of the exhaust gas, and there is a possibility that the amount of ash deposited cannot be estimated accurately. In order to suppress fluctuations in this calculated value, for example, the filter differential pressure of the filter 7 is detected while the vehicle is stopped and the accelerator operation amount is kept constant, in order to estimate the amount of ash deposited. It took a lot of effort.
　そこで、本開示では、判定部１５が、予め設定されたフィルタ７の基準差圧と差圧センサ１３で検出されたフィルタ差圧との圧力比に基づいて、フィルタ７におけるアッシュの堆積量を算出する。この方法では、例えば、排気ガスの流量が１．２倍になった場合に、フィルタ差圧と基準差圧の両者が１．４４倍になるため、圧力比は排気ガスの流量によらずに一定となる。これにより、算出されるアッシュの堆積量が排気ガスの流量に応じて変動することを抑制し、フィルタ７の状態を高精度に検知することができる。 Therefore, in the present disclosure, the determination unit 15 calculates the amount of ash deposited in the filter 7 based on the pressure ratio between the preset reference differential pressure of the filter 7 and the filter differential pressure detected by the differential pressure sensor 13. do. In this method, for example, when the flow rate of the exhaust gas increases 1.2 times, both the filter differential pressure and the reference differential pressure increase 1.44 times, so that the pressure ratio does not depend on the exhaust gas flow rate. It becomes constant. As a result, it is possible to suppress the calculated ash deposit amount from fluctuating according to the flow rate of the exhaust gas, and to detect the state of the filter 7 with high accuracy.
　また、判定部１５は、排気ガスの流量によらずに圧力比が一定となるため、車両を走行しつつアッシュの堆積量を算出することができる。このため、例えば、アクセルの操作量を一定に維持するなどの作業をする必要がなく、アッシュの堆積量を簡単に算出することができる。 Further, since the pressure ratio is constant regardless of the flow rate of the exhaust gas, the determination unit 15 can calculate the amount of ash deposited while traveling the vehicle. Therefore, for example, it is not necessary to maintain a constant amount of accelerator operation, and the amount of ash deposited can be easily calculated.
　また、算出部１４は、所定時間にわたって差圧センサ１３で順次検出された複数のフィルタ差圧に基づいて圧力比を算出する。このため、判定部１５は、算出部１４で算出された圧力比に基づいて、フィルタ７におけるアッシュの堆積量を正確に推定することができる。
　このとき、算出部１４は、フィルタ７の再生処理が完了してから約１時間以内のフィルタ差圧を順次取得することが好ましい。 Further, the calculation unit 14 calculates the pressure ratio based on the plurality of filter differential pressures sequentially detected by the differential pressure sensor 13 over a predetermined time. Therefore, the determination unit 15 can accurately estimate the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14.
At this time, it is preferable that the calculation unit 14 sequentially acquires the filter differential pressure within about 1 hour after the regeneration process of the filter 7 is completed.
　なお、算出部１４は、所定時間にわたって差圧センサ１３で順次検出される複数のフィルタ差圧のうち、内燃機関１が定常状態付近で稼働しているときのフィルタ差圧に基づいて圧力比を算出することが好ましい。算出部１４は、例えば、内燃機関制御部４から内燃機関１の稼働情報を取得し、その稼働情報に基づいて内燃機関１が定常状態付近で稼働している期間を求める。そして、算出部１４は、その期間に差圧センサ１３で検出されたフィルタ差圧に基づいて圧力比を算出する。これにより、算出部１４は、圧力比を正確に算出することができる。 The calculation unit 14 calculates the pressure ratio based on the filter differential pressure when the internal combustion engine 1 is operating near the steady state among the plurality of filter differential pressures sequentially detected by the differential pressure sensor 13 over a predetermined time. It is preferable to calculate. For example, the calculation unit 14 acquires the operation information of the internal combustion engine 1 from the internal combustion engine control unit 4, and obtains the period during which the internal combustion engine 1 is operating near the steady state based on the operation information. Then, the calculation unit 14 calculates the pressure ratio based on the filter differential pressure detected by the differential pressure sensor 13 during that period. As a result, the calculation unit 14 can accurately calculate the pressure ratio.
　また、算出部１４は、粒子状物質が全体に堆積したフィルタ７に基づいて予め設定された基準差圧と、フィルタ７の再生処理の直後に差圧センサ１３で検出されたフィルタ差圧、すなわち煤成分がほとんど除去されてアッシュのみが堆積した状態のフィルタ７のフィルタ差圧との圧力比を算出する。このため、判定部１５は、この圧力比に基づいてフィルタ７におけるアッシュの堆積量を正確に推定することができる。 Further, the calculation unit 14 has a reference differential pressure set in advance based on the filter 7 in which particulate matter is deposited on the whole, and a filter differential pressure detected by the differential pressure sensor 13 immediately after the regeneration process of the filter 7, that is, The pressure ratio with the filter differential pressure of the filter 7 in a state where most of the soot component is removed and only ash is deposited is calculated. Therefore, the determination unit 15 can accurately estimate the amount of ash deposited in the filter 7 based on this pressure ratio.
　このようにして、算出部１４は、図４に示すように、フィルタ７の再生処理が実施される度に、予め設定されたフィルタ７の基準差圧と差圧センサ１３で検出されたフィルタ差圧との圧力比を算出する。続いて、判定部１５が、算出部１４で算出された圧力比に基づいてフィルタ７におけるアッシュの堆積量を推定する。そして、判定部１５が、推定されたアッシュの堆積量に基づいてフィルタ７のメンテナンス時期を判定する。 In this way, as shown in FIG. 4, the calculation unit 14 determines the reference differential pressure of the preset filter 7 and the filter difference detected by the differential pressure sensor 13 each time the reproduction process of the filter 7 is performed. Calculate the pressure ratio to the pressure. Subsequently, the determination unit 15 estimates the amount of ash deposited in the filter 7 based on the pressure ratio calculated by the calculation unit 14. Then, the determination unit 15 determines the maintenance time of the filter 7 based on the estimated amount of ash deposited.
　例えば、判定部１５には、フィルタ７のメンテナンスが必要となる圧力比の閾値Ｔが予め設定されている。判定部１５は、圧力比が閾値Ｔに近づくほど、フィルタ７におけるアッシュの堆積量が増加したと推定する。そして、判定部１５は、圧力比が閾値Ｔを超えた場合には、フィルタ７に所定量のアッシュが堆積したと推定し、フィルタ７のメンテナンスが必要と判定する。 For example, the determination unit 15 is preset with a threshold value T of a pressure ratio that requires maintenance of the filter 7. The determination unit 15 estimates that the amount of ash deposited on the filter 7 increases as the pressure ratio approaches the threshold value T. Then, when the pressure ratio exceeds the threshold value T, the determination unit 15 estimates that a predetermined amount of ash has accumulated on the filter 7, and determines that maintenance of the filter 7 is necessary.
　判定部１５は、判定結果を報知部１６に出力すると共に、通信部１７を介して情報提供部１８に出力する。そして、報知部１６が、判定部１５の判定結果に基づいて、フィルタ７のメンテナンス時期を表示するなどして車両の使用者に報知する。また、情報提供部１８が、判定部１５の判定結果に基づいて、フィルタ７のメンテナンス時期を連絡するなどして車両の使用者に提供する。
　このように、フィルタ７のメンテナンス時期が提供されることにより、車両の使用者は、フィルタ７の洗浄および交換などのメンテナンスを効率的に行うことができる。 The determination unit 15 outputs the determination result to the notification unit 16 and outputs the determination result to the information providing unit 18 via the communication unit 17. Then, the notification unit 16 notifies the vehicle user by displaying the maintenance time of the filter 7 based on the determination result of the determination unit 15. Further, the information providing unit 18 provides the vehicle user with the maintenance time of the filter 7 based on the determination result of the determination unit 15.
By providing the maintenance period of the filter 7 in this way, the user of the vehicle can efficiently perform maintenance such as cleaning and replacement of the filter 7.
　さらに、判定部１５は、算出部１４で算出される圧力比が１．０を超えた場合には、フィルタ７以外の装置の不具合と判定することができる。判定部１５は、例えば、内燃機関１、酸化触媒６、バルブ９およびインジェクタ１０などの装置の不具合で排気ガスが高温に加熱されていないと判定することができる。 Further, when the pressure ratio calculated by the calculation unit 14 exceeds 1.0, the determination unit 15 can determine that the device other than the filter 7 is defective. The determination unit 15 can determine that the exhaust gas is not heated to a high temperature due to a malfunction of devices such as the internal combustion engine 1, the oxidation catalyst 6, the valve 9, and the injector 10.
　本実施の形態によれば、判定部１５が、排気ガスの流量に応じて予め設定されたフィルタ７の基準差圧と、差圧センサ１３で検出されたフィルタ差圧との圧力比に基づいて、フィルタ７におけるアッシュの堆積量を推定するため、フィルタ７の状態を高精度に検知することができる。 According to the present embodiment, the determination unit 15 is based on the pressure ratio between the reference differential pressure of the filter 7 preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor 13. Since the amount of ash deposited on the filter 7 is estimated, the state of the filter 7 can be detected with high accuracy.
（実施の形態２）
　以下、本開示の実施の形態２について説明する。ここでは、上記の実施の形態１との相違点を中心に説明し、上記の実施の形態１との共通点については、共通の参照符号を使用して、その詳細な説明を省略する。 (Embodiment 2)
Hereinafter, Embodiment 2 of the present disclosure will be described. Here, the differences from the first embodiment will be mainly described, and the common reference numerals will be used for the common points with the first embodiment, and detailed description thereof will be omitted.
　上記の実施の形態１では、判定部１５は、フィルタ７におけるアッシュの堆積量を推定したが、フィルタ７における粒子状物質の堆積量を推定できればよく、これに限られるものではない。 In the first embodiment described above, the determination unit 15 estimates the amount of ash deposited on the filter 7, but the present invention is not limited to this as long as the amount of particulate matter deposited on the filter 7 can be estimated.
　例えば、図５に示すように、実施の形態１の判定部１５に換えて判定部２１を配置すると共に、再生処理制御部１１に換えて再生処理制御部２２を配置することができる。判定部２１は、再生処理制御部２２に接続されている。 For example, as shown in FIG. 5, the determination unit 21 can be arranged in place of the determination unit 15 of the first embodiment, and the reproduction processing control unit 22 can be arranged in place of the reproduction processing control unit 11. The determination unit 21 is connected to the reproduction processing control unit 22.
　判定部２１は、算出部１４で算出される圧力比に基づいて、フィルタ７に堆積した煤成分およびアッシュを含む粒子状物質の堆積量を推定する。 The determination unit 21 estimates the amount of particulate matter including soot components and ash deposited on the filter 7 based on the pressure ratio calculated by the calculation unit 14.
　再生処理制御部２２は、判定部２１で推定された粒子状物質の堆積量に基づいて、フィルタ７の再生処理を開始するタイミングを判定する。 The regeneration processing control unit 22 determines the timing to start the regeneration processing of the filter 7 based on the accumulated amount of particulate matter estimated by the determination unit 21.
　このような構成により、算出部１４は、内燃機関１が駆動しているときに差圧センサ１３で検出されたフィルタ差圧を取得し、排気ガスの流量に応じて予め設定されたフィルタ７の基準差圧と、差圧センサ１３で検出されたフィルタ差圧との圧力比を順次算出する。算出部１４は、算出された圧力比を判定部２１に出力する。 With such a configuration, the calculation unit 14 acquires the filter differential pressure detected by the differential pressure sensor 13 while the internal combustion engine 1 is being driven, and the filter 7 is set in advance according to the flow rate of the exhaust gas. The pressure ratio between the reference differential pressure and the filter differential pressure detected by the differential pressure sensor 13 is sequentially calculated. The calculation unit 14 outputs the calculated pressure ratio to the determination unit 21.
　続いて、判定部２１が、算出部１４で算出された圧力比に基づいて、フィルタ７に堆積した粒子状物質の堆積量を推定する。ここで、実施の形態１と同様に、再生処理制御部２２に記憶されたマップが、粒子状物質を全体に堆積したフィルタ７に基づいて予め設定されているものとする。この場合には、判定部２１は、圧力比が１に近づくほど粒子状物質の堆積量が多く、圧力比がゼロに近づくほど粒子状物質の堆積量が少ないと推定する。 Subsequently, the determination unit 21 estimates the amount of particulate matter deposited on the filter 7 based on the pressure ratio calculated by the calculation unit 14. Here, it is assumed that the map stored in the regeneration processing control unit 22 is preset based on the filter 7 in which the particulate matter is deposited as a whole, as in the first embodiment. In this case, the determination unit 21 estimates that the closer the pressure ratio is to 1, the larger the amount of particulate matter deposited, and the closer the pressure ratio is to zero, the smaller the amount of particulate matter deposited.
　判定部２１には、フィルタ７の再生処理を実施する圧力比の閾値が予め設定されており、圧力比が閾値を超えた場合には、フィルタ７に所定量の粒子状物質が堆積したと推定する。判定部２１は、粒子状物質の堆積量を再生処理制御部２２に出力する。 A threshold value of the pressure ratio for executing the regeneration process of the filter 7 is preset in the determination unit 21, and when the pressure ratio exceeds the threshold value, it is estimated that a predetermined amount of particulate matter is deposited on the filter 7. do. The determination unit 21 outputs the accumulated amount of the particulate matter to the regeneration processing control unit 22.
　そして、再生処理制御部２２が、判定部２１においてフィルタ７に所定量の粒子状物質が堆積したと推定された場合には、フィルタ７の再生処理を開始すると判定する。 Then, when it is estimated in the determination unit 21 that a predetermined amount of particulate matter is deposited on the filter 7, the regeneration processing control unit 22 determines that the regeneration processing of the filter 7 is started.
　従来、再生処理制御部２２は、差圧センサ１３で検出されるフィルタ差圧に基づいて、フィルタ７の再生処理を開始するタイミングを判定していた。このため、排気ガスの流量に応じてフィルタ７の再生処理を開始するタイミングが変動し、フィルタ７に一定の堆積量で粒子状物質が堆積したときにフィルタの再生処理を開始することが困難であった。 Conventionally, the reproduction processing control unit 22 has determined the timing to start the reproduction processing of the filter 7 based on the filter differential pressure detected by the differential pressure sensor 13. For this reason, the timing for starting the regeneration process of the filter 7 varies depending on the flow rate of the exhaust gas, and it is difficult to start the regeneration process of the filter when particulate matter is deposited on the filter 7 with a constant deposition amount. there were.
　そこで、本開示では、判定部２１が、排気ガスの流量に応じて予め設定されたフィルタ７の基準差圧と、差圧センサ１３で検出されたフィルタ差圧との圧力比に基づいて、フィルタ７における粒子状物質の堆積量を推定する。そして、再生処理制御部２２が、判定部２１で推定されたフィルタ７における粒子状物質の堆積量に基づいて、フィルタ７の再生処理を開始するタイミングを判定する。このため、フィルタ７に一定の堆積量の粒子状物質が堆積したタイミングでフィルタ７を再生処理することができ、フィルタ７の再生処理を適切なタイミング実施することができる。 Therefore, in the present disclosure, the determination unit 21 filters based on the pressure ratio between the reference differential pressure of the filter 7 preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor 13. Estimate the amount of particulate matter deposited in 7. Then, the regeneration processing control unit 22 determines the timing to start the regeneration processing of the filter 7 based on the accumulated amount of the particulate matter in the filter 7 estimated by the determination unit 21. Therefore, the filter 7 can be regenerated at the timing when a certain amount of particulate matter is deposited on the filter 7, and the regenerating process of the filter 7 can be performed at an appropriate timing.
　このようにして、再生処理制御部２２が、フィルタ７の再生処理を開始すると判定すると、インジェクタ１０およびバルブ９を制御して排気ガスが高温に加熱される。これにより、フィルタ７に堆積した粒子状物質の煤成分が燃焼して、フィルタ７が再生処理される。 In this way, when the regeneration processing control unit 22 determines that the regeneration processing of the filter 7 is started, the injector 10 and the valve 9 are controlled to heat the exhaust gas to a high temperature. As a result, the soot component of the particulate matter deposited on the filter 7 is burned, and the filter 7 is regenerated.
　本実施の形態によれば、判定部２１が、排気ガスの流量に応じて予め設定されたフィルタ７の基準差圧と、差圧センサ１３で検出されたフィルタ差圧との圧力比に基づいて、フィルタ７における粒子状物質の堆積量を推定する。このため、再生処理制御部２２が、判定部２１で推定されたフィルタ７における粒子状物質の堆積量に基づいて、フィルタ７の再生処理を開始するタイミングを適切に判定することができる。 According to the present embodiment, the determination unit 21 is based on the pressure ratio between the reference differential pressure of the filter 7 preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor 13. , Estimate the amount of particulate matter deposited on the filter 7. Therefore, the regeneration processing control unit 22 can appropriately determine the timing at which the regeneration processing of the filter 7 is started based on the accumulated amount of the particulate matter in the filter 7 estimated by the determination unit 21.
　なお、上記の実施の形態１および２では、算出部１４は、所定時間にわたって差圧センサ１３で検出された複数のフィルタ差圧に基づいて圧力比が算出されたが、１つのフィルタ差圧に基づいて圧力比を算出してもよい。 In the above-described first and second embodiments, the calculation unit 14 calculates the pressure ratio based on the plurality of filter differential pressures detected by the differential pressure sensor 13 over a predetermined time, but the pressure ratio is calculated as one filter differential pressure. The pressure ratio may be calculated based on this.
　また、上記の実施の形態１および２では、算出部１４は、粒子状物質が全体に堆積したフィルタ７に基づいて基準差圧が予め設定されたが、排気ガスの流量に応じて基準差圧を設定できればよく、これに限られるものではない。例えば、算出部１４は、粒子状物質が堆積していないフィルタ７に基づいて基準差圧を設定することもできる。 Further, in the above-described first and second embodiments, the calculation unit 14 sets the reference differential pressure in advance based on the filter 7 in which the particulate matter is deposited on the whole, but the reference differential pressure is set according to the flow rate of the exhaust gas. It is only necessary to be able to set, and it is not limited to this. For example, the calculation unit 14 can set the reference differential pressure based on the filter 7 in which the particulate matter is not deposited.
　また、上記の実施の形態１および２では、算出部１４および判定部１５は、車両に配置されたが、外部に配置して通信回線で情報を送受信することもできる。 Further, in the above-described first and second embodiments, the calculation unit 14 and the determination unit 15 are arranged in the vehicle, but they can also be arranged outside to transmit / receive information via a communication line.
　また、上記の実施の形態１および２では、再生処理制御部は、インジェクタ１０を制御して排気ガスを高温に加熱させたが、酸化触媒６の反応熱で排気ガスを高温に加熱することができればよく、インジェクタ１０に限られるものではない。
　例えば、再生処理制御部は、内燃機関１の多段噴射を制御して酸化触媒６を反応させることができる。 Further, in the above-described first and second embodiments, the regeneration processing control unit controls the injector 10 to heat the exhaust gas to a high temperature, but the reaction heat of the oxidation catalyst 6 may heat the exhaust gas to a high temperature. If possible, it is not limited to the injector 10.
For example, the regeneration processing control unit can control the multi-stage injection of the internal combustion engine 1 to react the oxidation catalyst 6.
　その他、上記の実施の形態は、何れも本発明の実施をするにあたっての具体化の一例を示したものに過ぎず、これらによって本発明の技術的範囲が限定的に解釈されてはならないものである。すなわち、本発明はその要旨、またはその主要な特徴から逸脱することなく、様々な形で実施することができる。例えば、上記の実施の形態で説明した各部の形状や個数などについての開示はあくまで例示であり、適宜変更して実施することができる。 In addition, the above embodiments are merely examples of embodiment of the present invention, and the technical scope of the present invention should not be construed in a limited manner by these. be. That is, the present invention can be implemented in various forms without departing from its gist or its main features. For example, the disclosure of the shape, number, and the like of each part described in the above embodiment is merely an example, and can be appropriately modified and carried out.
　本出願は、２０２０年５月２９日付で出願された日本国特許出願（特願２０２０－０９４３２１）に基づくものであり、その内容はここに参照として取り込まれる。 This application is based on a Japanese patent application filed on May 29, 2020 (Japanese Patent Application No. 2020-094321), the contents of which are incorporated herein by reference.
　本開示に係るフィルタ状態検知装置は、排気ガスに含まれる粒子状物質を捕捉するフィルタが排気管に配置された装置に利用できる。 The filter state detection device according to the present disclosure can be used for a device in which a filter for capturing particulate matter contained in exhaust gas is arranged in an exhaust pipe.
　１　内燃機関
　２　吸気管
　３　排気管
　４　内燃機関制御部
　５　浄化装置
　６　酸化触媒
　７　フィルタ
　８ａ，８ｂ　温度センサ
　９　バルブ
　１０　インジェクタ
　１１，２２　再生処理制御部
　１２　フィルタ状態検知装置
　１３　差圧センサ
　１４　算出部
　１５，２１　判定部
　１６　報知部
　１７　通信部
　１８　情報提供部
　Ｓ１，Ｓ２　時間
　Ｅ　近似式
　Ｔ　閾値 1 Internal combustion engine 2 Intake pipe 3 Exhaust pipe 4 Internal combustion engine control unit 5 Purification device 6 Oxidation catalyst 7 Filter 8a, 8b Temperature sensor 9 Valve 10 Injector 11,22 Regeneration processing control unit 12 Filter state detection device 13 Differential pressure sensor 14 Calculation unit 15, 21 Judgment unit 16 Notification unit 17 Communication unit 18 Information provision unit S1, S2 Time E Approximate formula T Threshold

Claims (7)

  1. 　車両の排気ガスに含まれる粒子状物質を捕捉するために排気管に配置されたフィルタの上流側と下流側のフィルタ差圧を検出する差圧センサと、
    　前記排気ガスの流量に応じて予め設定された前記フィルタの上流側と下流側の基準差圧と、前記差圧センサで検出された前記フィルタ差圧との圧力比を算出する算出部と、
    　前記算出部で算出された圧力比に基づいて、前記フィルタにおける前記粒子状物質の堆積量を推定する判定部とを備えるフィルタ状態検知装置。     A differential pressure sensor that detects the differential pressure between the upstream and downstream filters of the filter placed in the exhaust pipe to capture particulate matter contained in the exhaust gas of the vehicle.
    A calculation unit that calculates the pressure ratio between the reference differential pressure on the upstream side and the downstream side of the filter preset according to the flow rate of the exhaust gas and the filter differential pressure detected by the differential pressure sensor.
    A filter state detection device including a determination unit for estimating the amount of deposited particulate matter in the filter based on the pressure ratio calculated by the calculation unit.
  2. 　前記算出部は、所定時間にわたって前記差圧センサで検出された複数のフィルタ差圧に基づいて前記圧力比を算出する請求項１に記載のフィルタ状態検知装置。 The filter state detection device according to claim 1, wherein the calculation unit calculates the pressure ratio based on a plurality of filter differential pressures detected by the differential pressure sensor over a predetermined time.
  3. 　前記算出部は、所定量の前記粒子状物質が堆積した前記フィルタに基づいて予め設定された前記基準差圧と、前記フィルタに堆積した前記粒子状物質を燃焼させる再生処理の直後に前記差圧センサで検出された前記フィルタ差圧との圧力比を算出する請求項１に記載のフィルタ状態検知装置。 The calculation unit has the reference differential pressure preset based on the filter in which a predetermined amount of the particulate matter is deposited, and the differential pressure immediately after the regeneration process of burning the particulate matter deposited on the filter. The filter state detection device according to claim 1, wherein the pressure ratio with the filter differential pressure detected by the sensor is calculated.
  4. 　前記算出部は、前記再生処理が実施される度に前記圧力比を算出する請求項３に記載のフィルタ状態検知装置。 The filter state detection device according to claim 3, wherein the calculation unit calculates the pressure ratio each time the regeneration process is performed.
  5. 　前記判定部は、前記粒子状物質のうちアッシュの堆積量を推定する請求項１に記載のフィルタ状態検知装置。 The filter state detection device according to claim 1, wherein the determination unit estimates the amount of ash deposited among the particulate matter.
  6. 　前記判定部は、推定された前記アッシュの堆積量に基づいて前記フィルタのメンテナンス時期を判定する請求項５に記載のフィルタ状態検知装置。 The filter state detection device according to claim 5, wherein the determination unit determines the maintenance time of the filter based on the estimated accumulated amount of the ash.
  7. 　前記判定部で判定された判定結果を無線で送信する通信部と、
    　前記通信部から送信された前記判定結果に基づいて前記フィルタのメンテナンス時期を車両の使用者に提供する情報提供部とをさらに有する請求項６に記載のフィルタ状態検知装置。     A communication unit that wirelessly transmits the determination result determined by the determination unit, and
    The filter state detecting device according to claim 6, further comprising an information providing unit that provides a vehicle user with a maintenance time of the filter based on the determination result transmitted from the communication unit.
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