JP2007162567A - Regeneration timing control device and regeneration timing control method of engine exhaust gas filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regeneration timing control device of an engine exhaust gas filter, properly setting start timing of a regeneration control of an engine exhaust gas filter. <P>SOLUTION: A regeneration timing control method comprises: an accumulation amount calculating means (a step S2) for calculating an accumulation amount of exhaust particulate accumulated on the exhaust gas filter which catches exhaust particulate contained in exhaust gas of an engine and prevents discharge of the exhaust particulate to the air; a travel distance calculating means (a step S1) for calculating a travel distance since the previous regeneration control is completed; a regeneration starting means (a step S7) for starting the regeneration control removing the exhaust particulate accumulated on the exhaust gas filter when the accumulation amount calculated by the accumulation amount calculating means exceeds a specified value or when the travel distance calculated by the travel distance calculating means exceeds a specified distance; and a regeneration start postponing means (steps S5 and S6) postponing start timing of the regeneration control when the accumulation amount calculated by the accumulation amount calculating means does not exceed the specified value and when the travel distance calculated by the travel distance calculating means exceeds the specified distance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus and method for controlling the regeneration timing of an exhaust gas filter that captures exhaust particulates contained in exhaust gas discharged from an engine and prevents its emission to the atmosphere.

  Conventionally, a diesel engine has been fitted with a diesel particulate filter (Diesel Particulate Filter; hereinafter referred to as “DPF”) that captures particulate matter (hereinafter referred to as “PM”) in the exhaust passage as a measure against exhaust gas purification. Yes. If the DPF continues to capture PM, it will eventually become clogged. If PM accumulates to some extent, the exhaust gas temperature is raised, and the accumulated PM is forcibly burned and removed to regenerate the DPF.

In order to determine whether or not PM has accumulated so that regeneration of the DPF is necessary, the PM accumulation amount is estimated based on the differential pressure (front-rear differential pressure) between the inlet and outlet of the DPF, or the operating state of the engine The estimation is based on the PM discharge amount (for example, rotation speed and fuel injection amount) (for example, Patent Document 1).
JP 2002-97930 A

  However, any of the above-described conventional methods may indirectly estimate the amount of accumulated PM instead of actually detecting it, and thus may be erroneously estimated. In the unlikely event that it is erroneously estimated to a small extent and the amount of accumulated PM actually increases, there is a risk that PM will overcombust during PM combustion removal and the DPF will melt.

  Therefore, in order to prevent the DPF from damaging even if it is erroneously estimated to a small extent, the present inventors have found that the estimated distance of PM deposition does not exceed the DPF regeneration start amount even when the travel distance exceeds the specified value. Started forced regeneration control.

  However, the start time of the regeneration control may be too early depending on the operating state.

  The present invention has been made paying attention to such a conventional problem, and an engine exhaust gas filter regeneration timing control device and regeneration timing control capable of appropriately setting the start timing of regeneration control of the engine exhaust gas filter. It aims to provide a method.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention captures exhaust particulates contained in the exhaust gas of the engine (10) to prevent emission to the atmosphere, and calculates the amount of exhaust particulates deposited on the exhaust gas filter (52). A deposit amount calculating means (step S2), a travel distance calculating means (step S1) for calculating a travel distance from the end of the previous regeneration control, and a deposit amount calculated by the deposit amount calculating means When it exceeds, or when the travel distance calculated by the travel distance calculation means exceeds a specified distance, regeneration start means for starting regeneration control for removing exhaust particulates deposited on the exhaust gas filter (52) (step S7) ), And when the travel distance calculated by the travel distance calculation means exceeds the specified distance without the deposition amount calculated by the deposition amount calculation means exceeding the specified amount, the regeneration control is started. Reproduction start postponement means (step S5-S6, step S8-S10) to postpone the period and having a.

  According to the present invention, the start time of the regeneration control is postponed when the accumulated distance of the exhaust particulates calculated by the accumulation amount calculation means does not exceed the specified amount and the travel distance exceeds the specified distance. The start time of regeneration control of the engine exhaust gas filter can be set appropriately.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram for explaining the action of a DPF in normal operation of a diesel engine. FIG. 1 (A) shows a state when PM is captured, and FIG. The state when playing is shown.

  First, in order to facilitate understanding of the present invention, the inventors' knowledge will be described with reference to FIG. Conventionally, as described above, the PM accumulation amount is estimated based on the differential pressure (front-rear differential pressure) between the inlet and the outlet of the DPF, or the PM emission amount depending on the operating state of the engine (for example, the rotational speed and the fuel injection amount). The DPF regeneration start time is determined based on the estimated PM accumulation amount. However, if the amount of accumulated PM is indirectly detected and estimated in this way, there is a possibility that the DPF may be melted and erroneously estimated. Therefore, in order to prevent the DPF from damaging even if it is erroneously estimated to a small extent, the present inventors have found that the estimated distance of PM deposition does not exceed the DPF regeneration start amount even when the travel distance exceeds the specified value. Decided to start forced regeneration control.

  However, the start time of the regeneration control may be too early depending on the operating state. The inventors have earnestly studied day and night, and have found that this cause is the natural regeneration of DPF.

  This point will be described in detail with reference to FIG. The DPF has a porous honeycomb structure made of ceramic such as cordierite. In the DPF, flow paths are partitioned in a lattice shape by a porous thin wall. As shown in FIG. 1A, the inlets of the respective channels are alternately sealed. In the flow path where the inlet is not sealed, the outlet is sealed.

  As shown by the arrows in the figure, the exhaust gas flowing into the DPF permeates through the porous thin walls that define the flow paths and is discharged downstream. During normal operation, as shown in FIG. 1A, PM contained in the exhaust gas is trapped and deposited on the inner surface of the porous thin wall. Although a part of the trapped PM burns in the DPF, if the DPF temperature (BED temperature) is not high, the combustion amount is small and the deposition amount is larger than the PM combustion amount. If this state continues and the DPF continues to capture PM, it will eventually become clogged. Therefore, when the PM is accumulated to some extent, the exhaust gas temperature is raised and the accumulated PM is forcibly removed by combustion.

  On the other hand, during high-speed traveling, the exhaust gas temperature is high, and the DPF temperature (BED temperature) is also high. In this state, as shown in FIG. 1B, when PM contained in the exhaust gas is captured on the inner surface of the porous thin wall of the DPF, it spontaneously burns without accumulating.

  Thus, according to the present inventors, it has been found that when the exhaust gas temperature is high and the temperature of the DPF (BED temperature) is also high, PM burns and the DPF naturally regenerates. Then, the present inventors have found that the start time of the regeneration control may be too early unless such natural regeneration is taken into consideration.

  Therefore, in the present invention, when the travel distance exceeds the specified value, the regeneration control is started even if the PM accumulation estimated amount does not exceed the DPF regeneration start amount, and in this case, the DPF is naturally regenerated. In this case, forced regeneration is not performed and the start time of regeneration control is delayed.

  FIG. 2 is an overall system diagram showing the engine exhaust gas filter regeneration timing control apparatus according to the first embodiment of the present invention.

  The engine exhaust gas filter regeneration timing control device 1 includes a diesel engine 10, an intake passage 21, a throttle valve 22, an exhaust passage 23, an exhaust gas recirculation (hereinafter referred to as “EGR device”) 30, A diesel oxidation catalyst (Diesel Oxidative Catalyst; hereinafter referred to as “DOC”) 40, a DPF assembly 50, sensors 61 to 64, and a controller 70 are included.

  The diesel engine 10 is injected with fuel, which has been increased in pressure by the high-pressure pump 14 and once accumulated in the common rail 13, from the injector 12 in accordance with the injection timing.

  Part of the exhaust gas discharged from the diesel engine 10 returns to the intake passage 21 via the EGR device 30. The EGR device 30 includes an EGR cooler 32 and an EGR valve 33 in the EGR passage 31. The EGR cooler 32 cools the exhaust gas recirculated from the exhaust passage 23. The EGR valve 33 is opened and closed to adjust the EGR amount. The EGR valve 33 is duty-controlled by the controller 70.

  The DOC 40 is provided in the exhaust passage 23 of the diesel engine 10 and reduces particulate matter by an oxidizing action by a catalyst such as palladium or platinum. When an unburned component (hydrocarbon HC) flows into the DOC 40, exhaust gas that has become a high temperature due to the catalytic reaction flows out of the DOC 40.

  The DPF assembly 50 is provided further downstream of the DOC 40. The DPF assembly 50 incorporates a DPF 52 in a DPF housing 51. The DPF 52 has a porous honeycomb structure made of ceramic such as cordierite. In the DPF 52, flow paths are partitioned in a lattice shape by porous thin walls. As shown in FIG. 1, the inlets of the respective channels are alternately sealed. In the flow path where the inlet is not sealed, the outlet is sealed.

  The differential pressure sensor 61 detects the differential pressure in the upstream chamber 51 a (inlet of the DPF 52) and the downstream chamber 51 b (exit of the DPF 52) of the DPF housing 51, and outputs a differential pressure signal to the controller 70.

  The DPF inlet temperature sensor 62 detects the inlet temperature Tin of the DPF 52 and outputs an inlet temperature signal to the controller 70.

  The DPF outlet temperature sensor 63 detects the outlet temperature Tout of the DPF 52 and outputs an outlet temperature signal to the controller 70.

  The crank angle sensor 64 detects the rotational speed of the crankshaft 11 of the diesel engine 10.

  The controller 70 receives a differential pressure signal from the differential pressure sensor 61, and estimates the PM accumulation amount PMa1 of the DPF 52 based on the magnitude of the differential pressure. Further, the PM accumulation amount PMa21 in the DPF 52 is obtained by integrating the PM emission amount based on the PM emission amount map for each engine operating state (for example, the rotation speed and the fuel injection amount). The DPF state (previously estimated PM deposition amount, BED temperature and inlet temperature) is applied to the characteristic map stored in advance in the ROM to obtain the DPF PM combustion amount PMa22. Then, the PM accumulation amount PMa2 is estimated by subtracting the PM combustion amount PMa22 from the PM accumulation amount PMa21. The controller 70 inputs the inlet temperature signal of the DPF inlet temperature sensor 62 and the outlet temperature signal of the DPF outlet temperature sensor 63, and calculates the BED temperature of the DPF 52 based on these signals. The controller 70 determines the optimum gear position (gear ratio) from the operating state of the engine, and calculates the travel distance together with the signal of the crank angle sensor 64.

  The controller 70 controls the injector 12 and the high-pressure pump 14 based on the input signal to adjust the fuel injection amount and the injection timing. The controller 70 adjusts the opening degree of the throttle valve 22 based on the input signal. The controller 70 performs duty control on the EGR valve 33. The controller 70 controls these to adjust the excess air ratio (air-fuel ratio) (λ control) to adjust the unburned components (hydrocarbon HC) contained in the exhaust gas, and increase the exhaust gas temperature flowing out from the DOC 40 And DPF regeneration is executed.

  The controller 70 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface).

  Next, with reference to the operation of the controller 70, the specific operation of the engine exhaust gas filter regeneration timing control apparatus according to the present invention will be described.

  FIG. 3 is a flowchart for explaining a regeneration start distance threshold setting routine of the regeneration timing control device for the engine exhaust gas filter. The controller 70 executes this process only once when the previous reproduction control is finished.

  In step S101, the controller 70 determines whether or not the DPF 52 has been completely regenerated by the previous regeneration control. Specifically, it is determined whether or not complete regeneration has been performed based on the PM residual accumulation amount when the previous DPF regeneration control has been completed. When the complete reproduction is performed, the process proceeds to step S102, and when partial reproduction is performed, the process proceeds to step S103.

  In step S102, the controller 70 sets L1 as the reproduction start distance threshold LC.

  In step S103, the controller 70 sets L2 as the reproduction start distance threshold LC. L2 is smaller than L1.

  FIG. 4 is a main flowchart for explaining the operation of the first embodiment of the regeneration timing control device for the engine exhaust gas filter. The controller 70 repeatedly executes this process every certain minute time (for example, 10 milliseconds).

  In step S1, the controller 70 obtains the travel distance L0 during the current processing cycle from the engine speed and the shift speed (gear ratio), and adds the travel distance L0 to the integrated travel distance L. As a result, the travel distance L from the end of the previous regeneration control is calculated.

  In step S2, the controller 70 estimates the PM accumulation amount PMa. A specific estimation method will be described later.

  In step S3, the controller 70 determines whether or not the PM accumulation amount PMa is larger than the regeneration start threshold value PMc. If it is larger, the process proceeds to step S7, and if not, the process proceeds to step S4. Note that the regeneration start threshold value PMc is set in advance through experiments.

  In step S4, the controller 70 determines whether or not the integrated travel distance L is greater than the regeneration start distance threshold Lc. If it is larger, the process proceeds to step S5, and if not, the process is temporarily exited. Note that the reproduction start distance threshold Lc is set in the above-described reproduction start distance threshold setting routine.

  In step S5, the controller 70 determines whether or not the DPF 52 is in the natural regeneration state, and sets the flag F. Specific processing will be described later.

  In step S6, the controller 70 determines whether or not the flag F is 1 (that is, the DPF 52 is in the natural regeneration state). If the flag F is 1, the process is temporarily exited. Otherwise, the process proceeds to step S7.

  In step S <b> 7, the controller 70 starts regeneration control of the DPF 52.

  FIG. 5 is a flowchart of a subroutine showing the PM accumulation amount estimation processing.

  In step S21, the controller 70 obtains the PM deposition amount PMa1 deposited on the DPF 52 by applying the differential pressure detection value ΔP before and after the DPF of the differential pressure sensor 61 to the characteristic map stored in the ROM in advance. This map is set in advance through experiments.

  In step S22, the controller 70 applies the engine operating state (rotation speed and fuel injection amount) to the characteristic map stored in the ROM in advance to calculate the PM emission amount from the engine, and integrates this PM emission amount. Thus, the PM deposition amount PMa21 on the DPF 52 is obtained. The DPF state (previously estimated PM deposition amount, BED temperature and inlet temperature) is applied to the characteristic map stored in advance in the ROM to obtain the DPF PM combustion amount PMa22. Then, the PM combustion amount PMa22 is subtracted from the PM deposition amount PMa21 to obtain the PM deposition amount PMa2. That is, PMa2 = PMa21−PMa22. These maps are set in advance through experiments.

  In step S23, the controller 70 determines whether or not the PM accumulation amount PMa1 due to the differential pressure across the DPF is larger than the PM accumulation amount PMa2 due to the operating state. If it is larger, the process proceeds to step S24, and if not, the process proceeds to step S25.

  In step S24, the controller 70 sets the PM accumulation amount PMa1 based on the differential pressure across the DPF as the PM accumulation amount PMa.

  In step S25, the controller 70 sets the PM deposition amount PMa2 depending on the operation state as the PM deposition amount PMa.

  FIG. 6 is a flowchart of a subroutine showing the natural reproduction determination process.

  In step S51, the controller 70 calculates the average vehicle speed Vave. The average vehicle speed Vave is a moving average value from the present to a predetermined time before, and the travel distance L0 during the processing cycle obtained in step S1 is sequentially stored and calculated.

  In step S52, the controller 70 determines whether or not the average vehicle speed Vave is smaller than the natural regeneration travel speed threshold value Vc. If it is smaller, the process is temporarily exited. If not, the process proceeds to step S7. The natural regeneration travel speed threshold value Vc is set in advance through experiments. When the average vehicle speed Vave is greater than the natural regeneration travel speed threshold value Vc, the exhaust gas temperature is high, PM burns inside the DPF 52, and the natural regeneration of the DPF 52 is performed.

  In step S53, the controller 70 sets 0 to the flag F.

  In step S54, the controller 70 sets 1 to the flag F.

  FIG. 7 is a diagram illustrating a control result of the first embodiment. The horizontal axis is the travel distance from the end of the previous regeneration, and the vertical axis is the PM accumulation amount and average vehicle speed in the DPF. In the previous time, the regeneration was complete, and the PM accumulation amount was zero when the travel distance was zero. Therefore, L1 is set as the reproduction start distance threshold LC by the reproduction start distance threshold setting routine. In addition, step numbers are added with S to make it easy to understand the correspondence with the flowchart.

  Until the PM accumulation amount PMa exceeds the threshold value PMc or the travel distance exceeds L1, the processes of steps S1, S2, S3, and S4 are repeated.

  In FIG. 7, the travel distance reaches L1 without the PM accumulation amount PMa exceeding the threshold value PMc. Then, the process proceeds from step S4 to step S5, and natural reproduction determination is performed. Since the average vehicle speed Vave is larger than the natural regeneration travel speed threshold value Vc, 1 is set in the flag F (step S54), and the process is temporarily exited from step S6. Steps S1, S2, S3, S4, S5, and S6 are repeated until the travel distance reaches L3. As shown in FIG. 7, the DPF 52 naturally regenerates during this time, and the PM deposition amount decreases.

  Then, the average vehicle speed Vave decreases, and the average vehicle speed Vave becomes smaller than the natural regeneration travel speed threshold Vc at the travel distance L3. Then, 0 is set to the flag F in step S53. In response to this, the process proceeds from step S6 to step S7, and regeneration control of the DPF 52 is started.

  According to the present embodiment, the regeneration control is started not only by the estimated accumulation amount of PM but also by the travel distance. Therefore, even if the accumulation amount of PM is erroneously estimated, the DPF may be melted. There is no. Since the regeneration start distance threshold Lc is postponed in consideration of the natural regeneration of the DPF due to high-speed travel, useless regeneration control does not occur and fuel consumption deterioration can be prevented.

(Second Embodiment)
FIG. 8 is a main flowchart for explaining the operation of the second embodiment of the regeneration timing control device for the engine exhaust gas filter. The controller 70 repeats this process every certain minute time (for example, 10 milliseconds). In the following description, the same reference numerals are given to portions that perform the same functions as those in the first embodiment, and overlapping descriptions are omitted as appropriate. The second embodiment is different from the first embodiment in step S8, step S9, and step S10, and these will be mainly described.

  In step S <b> 8, the controller 70 determines whether or not the threshold postponement flag F is 1. The initial value of this flag is zero and is set to 1 in step S10. If the flag F is 1, the process proceeds to step S7, and if not, the process proceeds to step S9.

  In step S9, the controller 70 corrects the reproduction start distance threshold Lc. A specific correction method will be described later.

  In step S10, the controller 70 sets the threshold postponement flag F to 1.

  FIG. 9 is a flowchart of a subroutine showing the reproduction start distance threshold value correcting process.

  In step S91, the controller 70 calculates ΔPM.

  In step S92, the controller 70 calculates ΔLmend by applying ΔPM to the characteristic map shown in FIG. 10 stored in advance in the ROM.

  In step S93, the controller 70 corrects the reproduction start distance threshold Lc by adding the threshold extension amount Lamend.

  FIG. 11 is a diagram illustrating a control result of the second embodiment. The horizontal axis is the travel distance from the end of the previous regeneration, and the vertical axis is the PM accumulation amount in the DPF. In the previous time, the regeneration was complete, and the PM accumulation amount was zero when the travel distance was zero. Therefore, L1 is set as the reproduction start distance threshold LC by the reproduction start distance threshold setting routine. In addition, step numbers are added with S to make it easy to understand the correspondence with the flowchart.

  Until the PM accumulation amount PMa exceeds the threshold value PMc or the travel distance exceeds L1, the processes of steps S1, S2, S3, and S4 are repeated.

  In FIG. 11, the travel distance reaches L1 without the PM accumulation amount PMa exceeding the threshold value PMc. Then, the process proceeds from step S4 to step S8, and it is determined whether or not the threshold postponement flag F is 1. Since the initial value of the flag F is zero, the process proceeds to step S9.

  A difference ΔPM between the regeneration start threshold value PMc and the PM accumulation amount PMa is calculated (step S91), a threshold extension amount Lamend is calculated (step S92), and the regeneration start distance threshold value Lc is postponed (step S93). In step S10, the threshold postponement flag F is set to 1.

  In the next cycle, the process proceeds from step S 1 → S 2 → S 3 → S 4 → S 8 → S 7 and the regeneration control of the DPF 52 is started.

  Also according to this embodiment, since regeneration control is started not only by the estimated amount of PM deposition but also by the travel distance, even if the PM accumulation amount is estimated to be small, the DPF may be damaged. Absent. Since the regeneration start distance threshold Lc is postponed in accordance with the difference ΔPM between the regeneration start threshold value PMc and the PM accumulation amount PMa, the speed is high but flows into the DPF as in high-speed running in a cold region. Even when the exhaust gas temperature does not become so high, appropriate regeneration control can be performed, and deterioration of fuel consumption can be prevented.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

  For example, in the first embodiment, the natural regeneration of the DPF is determined based on the traveling speed, and if the traveling speed is high, the natural regeneration is performed. However, the concept is not limited to this, and natural regeneration may be determined when high rotation continues for a specified time based on, for example, the engine rotation speed. Further, the natural regeneration of the DPF may be determined based on the BED temperature of the DPF or the inlet temperature of the DPF. The BED temperature of the DPF may be detected by attaching a sensor to the DPF. The map is only an example, and may be appropriately selected by experiment. Further, the regeneration start distance threshold Lc is set in a binary manner depending on whether or not the DPF has been completely controlled by the previous regeneration control. However, the regeneration start distance threshold Lc may be set in proportion to the PM residual accumulation amount. .

  Further, in the second embodiment, the reproduction start distance threshold Lc is postponed only once, but it may be postponed two or more times.

  Furthermore, in the said embodiment, although the diesel engine was mentioned as an example and demonstrated as an engine, a gasoline engine may be sufficient.

It is a schematic diagram explaining the effect | action of DPF in the normal driving | operation of a diesel engine. 1 is an overall system diagram illustrating a regeneration timing control device for an engine exhaust gas filter according to a first embodiment of the present invention. It is a flowchart explaining the regeneration start distance threshold value setting routine of the regeneration timing control device for the engine exhaust gas filter. It is a main flowchart explaining operation | movement of 1st Embodiment of the regeneration timing control apparatus of an engine exhaust gas filter. It is a flowchart of a subroutine showing PM accumulation amount estimation processing. It is a flowchart of a subroutine showing a natural reproduction determination process. It is a figure which shows the control result of 1st Embodiment. It is a main flowchart explaining operation | movement of 2nd Embodiment of the regeneration timing control apparatus of an engine exhaust gas filter. It is a flowchart of a subroutine showing a reproduction start distance threshold value correction process. It is a characteristic map for calculating | requiring the threshold value extension amount Lamend. It is a figure which shows the control result of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine exhaust gas filter regeneration timing control device 10 Diesel engine 50 DPF assembly 52 DPF (diesel particulate filter)
61 Differential pressure sensor 62 DPF inlet temperature sensor 63 DPF outlet temperature sensor 70 Controller Step S1 Travel distance calculation means / travel distance calculation step Step S2 Accumulation amount calculation means / deposition amount calculation step Step S7 Regeneration start means / Regeneration start step Step S5- S6, Steps S8-S10 Reproduction start postponement means / Reproduction start postponement step

Claims (8)

An exhaust gas filter that captures exhaust particulates contained in the exhaust gas of the engine and prevents emission to the atmosphere;
A deposition amount calculating means for calculating a deposition amount of exhaust particulates deposited on the exhaust gas filter;
Mileage calculating means for calculating the mileage since the end of the previous regeneration control;
When the accumulation amount calculated by the accumulation amount calculation means exceeds a specified amount, or when the travel distance calculated by the travel distance calculation means exceeds a specified distance, exhaust particulates that accumulate on the exhaust gas filter are removed. Playback start means for starting playback control;
A regeneration start postponing means for postponing the start timing of the regeneration control when the travel distance calculated by the travel distance calculation means exceeds the specified distance without the deposition amount calculated by the deposition amount calculation means exceeding the specified amount;
A regeneration timing control device for an engine exhaust gas filter. The regeneration start postponing means is configured to allow the exhaust gas filter to be naturally regenerated when the accumulated distance calculated by the accumulated amount calculating means does not exceed a specified amount and the travel distance calculated by the travel distance calculating means exceeds a specified distance. In the case of, the start time of the playback control is postponed until the natural playback ends.
The regeneration timing control device for an engine exhaust gas filter according to claim 1. The regeneration start postponing means determines whether or not the exhaust gas filter is undergoing natural regeneration based on a vehicle speed.
The regeneration timing control device for an engine exhaust gas filter according to claim 2. The regeneration start postponing means determines whether or not the exhaust gas filter is undergoing natural regeneration based on the rotational speed of the engine.
The regeneration timing control device for an engine exhaust gas filter according to claim 2. The regeneration start postponing means determines whether or not the exhaust gas filter is undergoing natural regeneration based on the temperature of the exhaust gas filter.
The regeneration timing control device for an engine exhaust gas filter according to claim 2. The regeneration start postponing means, when the travel distance calculated by the travel distance calculation means exceeds the specified distance without the deposit amount calculated by the deposit amount calculation means exceeding the specified amount, The start time of regeneration control is postponed according to the margin for the specified amount of accumulated deposit
The regeneration timing control device for an engine exhaust gas filter according to claim 1. Changing the specified distance based on the amount of PM remaining in the previous regeneration control;
The regeneration timing control device for an engine exhaust gas filter according to any one of claims 1 to 6, wherein An accumulation amount calculating step for calculating an accumulation amount of exhaust particulates to be deposited on an exhaust gas filter that captures exhaust particulates contained in engine exhaust gas and prevents emission to the atmosphere;
A mileage calculating step for calculating a mileage since the end of the previous regeneration control;
When the accumulation amount calculated in the accumulation amount calculation step exceeds a specified amount, or when the travel distance calculated in the travel distance calculation step exceeds a specified distance, exhaust particulates deposited on the exhaust gas filter are removed. A playback start step for starting playback control;
A regeneration start postponement step for postponing the start timing of the regeneration control when the travel distance calculated in the travel distance calculation step exceeds the specified distance without the deposition amount calculated in the deposition amount calculation step exceeding the specified amount;
An engine exhaust gas filter regeneration timing control method.

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