JP4266098B2 - Filter control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter control device capable of regenerating a filter for collecting particulates contained in engine exhaust gas at an appropriate timing.
[0002]
[Prior art]
In order to suppress the diffusion of fine particles contained in the exhaust gas of a diesel engine into the atmosphere, various devices have recently been installed in the exhaust system of a diesel engine to post-process diesel particulates in the exhaust gas. Has been developed. Each of these types of exhaust gas treatment apparatuses includes a filter for collecting particulates contained in the exhaust gas discharged from the diesel engine when the exhaust gas passes through the exhaust passage. Therefore, the collected particulates are gradually accumulated on the filter, and finally the filter becomes clogged, resulting in an increase in loss due to an increase in exhaust resistance.
[0003]
For this reason, conventionally, when it is estimated that the accumulated amount of the particulates in the filter has reached a predetermined level, the particulates are incinerated by heating the filter, for example, to regenerate the particulates, and the particulates again It can be collected. As described above, since the regeneration of the filter is based on the means of incineration of the particulates by heating the filter, the filter is subjected to a thermal load, and thus the regeneration is repeated at an appropriate timing corresponding to the collection ability of the filter. Thus, the frequency of filter regeneration must be minimized and the filter must be used effectively.
[0004]
Therefore, conventionally, the amount of particulates accumulated on the filter is estimated by measuring the differential pressure of the exhaust gas before and after the filter, the regeneration timing of the filter is determined according to the estimation result, and the regeneration control of the filter is performed. The arrangements made are widely used. Japanese Patent Laid-Open No. 2000-170521 estimates the particulate accumulation amount based on various parameters indicating the operating state of the engine without performing differential pressure measurement, and based on this estimation result, the appropriate particulate matter is estimated. A method is disclosed in which the regeneration operation of the curate filter can be performed.
[0005]
[Problems to be solved by the invention]
According to the configuration disclosed in Japanese Patent Application Laid-Open No. 2000-170521, the particulate discharge amount is calculated from the operating state of the engine and the collection efficiency is also calculated, and the particulate matter is calculated from the particulate discharge amount and the collection efficiency. Calculates the amount of curate collected. Here, the particulate emissions are calculated based on the fuel injection amount and the engine speed. However, the particulate emissions are greatly influenced by other operating efficiency of the engine, so the fuel injection amount The amount of generated particulates cannot be calculated with high accuracy by estimation based on the engine speed. Therefore, it is difficult to accurately estimate an appropriate regeneration timing of the particulate collection filter.
[0006]
In order to accurately estimate the regeneration timing of the filter, in addition to accurately accumulating the accumulated amount of particulates, it is also necessary to accurately estimate the self-regeneration amount. However, this conventional estimation is based solely on the exhaust gas temperature and its duration, and does not consider other factors that affect the actual combustion state of the particulates. Could not do.
[0007]
Particulates are burned and regenerated by heating the filter or raising the exhaust gas temperature. If additives are added to the fuel for efficient self-regeneration in the filter, this additive Accumulates in the filter as incombustible ash and causes filter clogging. Therefore, it is necessary to determine the reproduction timing in consideration of this, but in the past, the filter reproduction timing has not been determined in consideration of this point, so the filter can be reproduced at an appropriate timing. There wasn't.
[0008]
Further, when the filter is regenerated and repeatedly used, it is necessary to appropriately determine the filter replacement time in addition to the estimation of the amount of particulates accumulated in the filter. In this case, the filter collection efficiency value can be used as one guideline for filter replacement, but the filter collection efficiency itself is also affected by the number of filter regenerations, and an appropriate filter replacement time is determined. A powerful method has not yet been established.
[0009]
An object of the present invention is to provide a filter control device capable of solving the above-mentioned problems in the prior art.
[0010]
[Means for Solving the Problems]
In order to solve the above problem, according to the first aspect of the present invention, the particulate accumulation amount in the filter for collecting particulates contained in the exhaust gas of the engine is estimated, and based on the estimation result, the filter accumulation is estimated. Load condition data indicating the load condition of the engine in a filter control device adapted to perform regeneration First estimated generation amount calculation means for calculating an estimated generation amount of particulates based on Change amount data indicating the change amount of the load state Second estimated generation amount calculation means for calculating an estimated generation amount of particulates based on the first and second estimated generation amount calculation means based on the sum of the calculation results of the first and second estimated generation amount calculation means Responsive to the first computing means for computing the estimated particulate generation amount, the second computing means for computing the estimated self-regeneration amount of the particulates based on the exhaust state of the engine, and the first and second computing means Third calculation means for calculating the estimated accumulation amount of the particulates in the filter at that time, and comparing the calculation result by the third calculation means with a given reference value to determine whether or not to start regeneration of the filter And a discriminating means for providing a filter control device.
[0011]
According to a second aspect of the present invention, there is proposed a filter control device according to the first aspect, wherein the load state data includes at least data indicating an accelerator operation amount or a gear ratio of a transmission.
[0012]
According to a third aspect of the present invention, there is provided a filter control device according to the first aspect, wherein the change amount data includes at least data indicating a change amount of an accelerator operation amount or a change amount of the engine speed. Is done.
[0013]
According to a fourth aspect of the present invention, in the first aspect of the invention, the first control means is configured to add a predetermined value to the estimated generation amount each time the engine is started. Is proposed.
[0014]
According to the invention of claim 5, in the invention of claim 1, In the second calculation means, the estimated self-regeneration amount is calculated in consideration of the air flow rate and the particulate accumulation amount in the filter. A filter control device is proposed.
[0015]
According to the invention of claim 6, Claim 1 The invention further includes start determination means for determining whether or not the engine has been started, and each time the first calculation means determines that the engine has been started by the start determination means. A filter control device is proposed in which a predetermined value is added to the estimated curate generation amount.
[0016]
According to the invention of claim 7, claims 1, 2, 3, 4 or 6 In the invention, a filter control device is proposed in which at least the engine coolant temperature or the outside air temperature is considered in the calculation of the estimated particulate generation amount in the first calculation means.
[0017]
According to the invention of claim 8, claims 1, 2, 3, 4 is 6 In the invention, a filter control device is proposed in which an initial value of the estimated particulate generation amount calculated by the first calculation means is determined according to the number of regeneration times of the filter.
[0018]
According to a ninth aspect of the present invention, there is proposed a filter control device according to the first aspect, wherein the reference value is determined according to the number of times of regeneration of the filter.
[0019]
According to a tenth aspect of the present invention, there is proposed a filter control device according to the ninth aspect, wherein an alarm for prompting replacement of the filter is output when the number of regeneration times of the filter reaches a predetermined value.
[0020]
According to an eleventh aspect of the present invention, there is proposed a filter control device according to the first aspect, wherein the second calculation means calculates an estimated self-regeneration amount further considering an air flow rate in the filter. .
[0021]
According to a twelfth aspect of the present invention, there is provided a filter control device according to the first aspect, wherein the second calculation means calculates an estimated self-regeneration amount further considering a particulate accumulation amount in the filter. Is done.
[0023]
Claim 13 According to the invention of claim 9, in the invention of claim 9, a filter control device is proposed in which the reference value is further determined in consideration of the amount of incombustible ash accumulated in the filter.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
[0025]
FIG. 1 is a block diagram showing an example of an embodiment of an exhaust gas processing apparatus provided with a filter control apparatus according to the present invention. The exhaust gas processing device 1 is a device for post-processing particulates contained in the exhaust gas of the diesel engine 2, and is provided between the outlet end 3 </ b> A of the exhaust manifold 3 of the diesel engine 2 and the exhaust muffler 4. ing. The exhaust gas processing apparatus 1 has an exhaust gas having a pair of parallel passage portions that are bifurcated into two at the inlet side at the outlet end 3A of the exhaust manifold 3 and are mutually bypassed so as to gather together at the exhaust muffler 4 side. A first filter 61 and a second filter 62 for collecting particulates in the exhaust gas are respectively provided in the first branch passage 51 and the second branch passage 52 having the passage 5 and constituting the parallel passage portion. Is provided.
[0026]
Both the first filter 61 and the second filter 62 have a known configuration used for this type of purpose, and all exhaust gas sent to the first branch passage 51 passes through the first filter 61. The exhaust gas is sent to the exhaust muffler 4 side, and at this time, the first filter 61 can effectively collect the particulates contained in the exhaust gas. The same applies to the second filter 62.
[0027]
In order to collect the particulates contained in the exhaust gas by one of the pair of filters constituted by the first filter 61 and the second filter 62, the first branch is provided at the outlet side of the exhaust gas passage 5. A switching valve device 7 is provided for selectively allowing the exhaust gas to flow through one of the passage 51 and the second branch passage 52. The switching valve device 7 is provided in the outlet portion 51A of the first branch passage 51, and is capable of arbitrarily adjusting the flow rate of the exhaust gas passing through the outlet portion 51A, and the outlet of the second branch passage 52. A second flow rate adjusting valve 72 is provided in the portion 52A and can arbitrarily adjust the flow rate of the exhaust gas passing through the outlet portion 52A.
[0028]
As described in detail later, the first flow rate control valve 71 and the second flow rate control valve 72 are driven and controlled by drive signals D1 and D2 from the control unit 8 so that when one is fully open, the other is substantially fully closed. Thus, the particulates in the exhaust gas of the diesel engine 2 can always be collected in any one of the first and second filters 61 and 62. Thus, when any one of the filters performs the particulate collection operation, the exhaust gas does not substantially flow through the other remaining filter.
[0029]
In order to be able to regenerate the filter by heating and removing the particulates accumulated there by the particulate collection operation of the first and second filters 61 and 62, the inlet of the exhaust gas passage 5 is used. On the side, there is provided a fuel combustion device indicated generally by 9.
[0030]
The fuel combustion apparatus 9 includes a first burner 91 disposed near the inlet of the filter 61 in the first branch passage 51 and a second burner 92 disposed near the inlet of the filter 62 in the second branch passage 52. The pressurized fuel obtained by pressurizing the fuel for the diesel engine 2 in the fuel tank 93 by the fuel pump 94 is supplied to the first and second burners 91, 92. It is configured to be supplied via a supply oil passage 95. Of course, the fuel supplied to the first and second burners 91 and 92 may be supplied not from the fuel tank 93 but from another fuel supply source provided separately via the supply oil passage 95. It is.
[0031]
The nozzle 91A of the first burner 91 is directed to the first filter 61, and a spark plug 96 for igniting the fuel injected from the nozzle 91A is disposed near the nozzle 91A. Similarly, the spark plug 97 is also disposed near the nozzle hole 92A for the nozzle hole 92A of the second burner 92. The on / off operation of these spark plugs 96, 97 is controlled by ignition control signals F1, F2 from the control unit 8.
[0032]
The first burner 91 is provided with an electromagnetic valve 91B that is controlled to open and close by a drive signal E1 from the control unit 8, and when the electromagnetic valve 91B is opened at a predetermined timing by a command from the control unit 8. Fuel is injected from the nozzle 91A toward the first filter 61, and the spark plug 96 operates in synchronism with this to generate an ignition spark, thereby causing the flame generated by the ignition of the fuel injected from the nozzle 91A to the first filter. The particulates radiated to the first filter 61 and accumulated in the first filter 61 can be heated and burned.
[0033]
Similarly, the second burner 92 is also provided with an electromagnetic valve 92B that is controlled to open and close by a drive signal E2 from the control unit 8, and the electromagnetic valve 92B is opened at a predetermined timing by a command from the control unit 8. At this time, the fuel is injected from the nozzle 92A toward the second filter 62, and the spark plug 97 operates in synchronism with this to generate an ignition spark. This causes the fuel injected from the nozzle 92A to ignite. The flame is radiated to the second filter 62, and the particulates accumulated in the second filter 62 can be heated and burned.
[0034]
Whether the heating and burning of the particulates in the first and second filters 61 and 62 are completed by the flames radiated as described above from the first and second burners 91 and 92, that is, whether the regeneration of the filter is completed. Temperature sensors 11 and 12 are provided on the outer peripheral surfaces 61A and 62A of the first and second filters 61 and 62, respectively, and the outer peripheral surfaces 61A and 62A are provided by the temperature sensors 11 and 12, respectively. The temperature signals T1 and T2 indicating the temperature are sent to the control unit 8.
[0035]
The control unit 8 is provided with a switching control for switching the flow path of the exhaust gas passage 5 so that the exhaust gas is sent to one of the first and second filters 61 and 62, and a filter in which particulates are accumulated by use. This is a unit for performing reproduction control for reproduction, and is configured as a computer control system using a microcomputer 81.
[0036]
FIG. 2 is a block diagram showing the configuration of the control unit 8. The control unit 8 includes a determination unit 82 that determines whether or not the filter regeneration processing should be performed by estimating and calculating the particulate accumulation amount of the filter collecting particulates in the exhaust gas. In the part 82, the calculation for estimating the particulate accumulation amount of the filter is performed as will be described in detail later, and the regeneration start signal X for instructing the start of the regeneration of the filter based on the particulate estimation amount obtained as a result of the estimation operation. Is output, and the reproduction start signal X is input to the switching control unit 83.
[0037]
In order to obtain data necessary for executing the required determination processing calculation in the determination unit 82, the control unit 8 includes an exhaust state detection unit 8A, a time detection unit 8B, a start determination unit 8C, and a first engine load state detection unit. 8D, the 2nd engine load state detection part 8E, the environmental condition detection part 8F, and the air quantity detection part 8G are provided.
[0038]
The exhaust state detection unit 8A receives an exhaust gas temperature signal T5 indicating the exhaust gas temperature on the input side of the filter from the temperature sensor 16 provided on the inlet side of the first and second filters 61 and 62, and receives the received exhaust gas temperature. Based on the signal T5, temperature data T0 indicating the exhaust gas temperature at that time is output. Based on the exhaust gas temperature signal T5, the time detection unit 8B outputs time data TM0 indicating the elapsed time during which the exhaust gas temperature is in a predetermined high temperature state. The start determination unit 8C responds to a rotation speed sensor (not shown) provided in the diesel engine 2 and outputs start determination data ST when it is determined that the engine is started.
[0039]
The first engine load state detection unit 8D responds to an accelerator opening sensor (not shown) and a gear shift position sensor (not shown) that detects a gear ratio provided in the transmission, and indicates the accelerator opening at that time. Data AS and gear ratio data VN indicating the current gear ratio of the transmission are output. The second engine load state detection unit 8E is based on a rotational speed signal output from a rotational speed sensor (not shown) provided in the diesel engine 2 and an accelerator opening signal obtained by an accelerator opening sensor (not shown). Engine speed change amount data ΔN indicating the amount of change in engine speed per unit time and accelerator change amount data ΔA indicating the amount of change in accelerator opening per unit time are output.
[0040]
The environmental condition detection unit 8F responds to a water temperature sensor (not shown) for detecting the engine cooling water temperature and an outside air temperature sensor for detecting the outside air temperature, and indicates temperature data T3 indicating the water temperature of the engine cooling water and the outside air temperature. The temperature data T4 is output. The air amount detector 8G receives the air amount signals A1 and A2 output from the flow rate sensors 13A and 13B that detect the amount of air flowing into each filter provided on the inlet side of each of the first and second filters 61 and 62. The first and second air amount data A10 and A20 based on the received air amount signals A1 and A2 are output, and all these data are input to the determination unit 82.
[0041]
The determination unit 82 includes a first accumulation amount counter 82A, a second accumulation amount counter 82B, a regeneration processing number counter 82C, and an EEPROM 82D. The first accumulation amount counter 82A is for counting the estimated accumulation amount of the particulates in the first or second filter 61, 62 collecting the particulates at that time, and the second accumulation amount counter 82B is The non-renewable incombustible ash generated due to the additive added to the fuel in order to efficiently perform self-regeneration in the first or second filter 61 or 62 collecting particulates at that time This is for counting the estimated amount of deposition. The reproduction process number counter 82C indicates the number of reproduction processes of the first or second filter 61 or 62 collecting particulates at that time. The EEPROM 82D is a non-volatile memory means for storing count values of the first accumulation amount counter 82A, the second accumulation amount counter 82B, and the regeneration processing number counter 82C when the control unit 8 is powered off. It is.
[0042]
The determination unit 82 also outputs a filter deterioration notification signal SX for prompting replacement of the filter when the number of filter regeneration times exceeds a predetermined number, and a warning signal SY when the exhaust gas temperature becomes high. The display device 86 performs a predetermined display in response to the output of the filter deterioration notification signal SX and the warning signal SY.
[0043]
In response to the regeneration start signal X, the switching control unit 83 outputs a switching command signal Y for instructing switching of the exhaust gas flow path in the exhaust gas passage 5. In response to the switch command signal Y, the drive unit 84 outputs drive signals D1 and D2 to invert the open / close states of the first flow rate control valve 71 and the second flow rate control valve 72 of the switch valve device 7, thereby switching the filter. I do.
[0044]
In response to the switching command signal Y, the regeneration control unit 85 heats the filter to be regenerated in order to regenerate the filter determined by the determining unit 82 that the particulate accumulation amount of the filter has exceeded a predetermined level. In order to control the operation of the fuel combustion apparatus 9, drive signals E1, E2 and ignition control signals F1, F2 are output.
[0045]
As a result, for example, when the second filter 62 is regenerated, the electromagnetic valve 91B remains closed by the drive signal E1, and the electromagnetic valve 92B is opened by the drive signal E2. Then, the ignition plug 97 is operated by the ignition control signal F 2, ignites the fuel injected from the injection hole 92 A, and sends the flame generated thereby to the second filter 62. The temperature of the second filter 62 is monitored by a temperature signal T2, and the electromagnetic valve 92B is closed when the temperature of the second filter 62 is equal to or higher than a predetermined value based on the temperature signal T2 for a predetermined time, and the second The regeneration of the filter 62 is completed.
[0046]
Although the regeneration of the second filter 62 has been described above, the regeneration of the first filter 61 is performed in the same manner. The exhaust gas treatment device 1 is not limited to the configuration of the above-described embodiment, and it is sufficient that the exhaust gas treatment device 1 has a configuration that regenerates at least a filter that collects particulates contained in the exhaust gas.
[0047]
Next, the determination unit 82 shown in FIG. 2 will be described in detail. The processing performed in the determination unit 82 is performed by executing a predetermined program in the microcomputer 81 in the control unit 8, and FIGS. 3 and 4 are flowcharts showing the predetermined program. It is.
[0048]
The determination unit 82 will be described with reference to the flowcharts shown in FIGS. After starting the program, in step S11, predetermined initialization is executed. At this time, the count values N, DD, and CD of the first accumulation amount counter 82A, the second accumulation amount counter 82B, and the regeneration processing number counter 82C are performed. Is set to zero and step S12 is entered. In step S12, the previous count value N stored in the EEPROM 82D is set in the first accumulation amount counter 82A, and the count value DD is set in the second accumulation amount counter 82B. Each counter is set to set the count value CD to the reproduction processing number counter 82C. Then, the process enters step S13, where execution of the task is started in the microcomputer 81, and step S14 is entered.
[0049]
Steps S <b> 14 to S <b> 21 are processes for estimating the amount of particulates accumulated in the first or second filter 61, 62. In step S14, it is determined whether or not the engine is starting in response to the start determination data ST. If it is determined that the engine is starting, the determination result in step S14 is YES and step S15 is entered. In step S15, a predetermined value Nb indicating the particulate accumulation amount on the filter at the time of engine start is added to the count value N at that time of the accumulation amount counter 82A. The predetermined value Nb indicates the amount of particulates generated per engine start, and Nb is added to N every time engine start is determined in step S14.
[0050]
By adding a predetermined value Nb when the engine is started, an estimation of the amount of accumulation is performed in consideration of the fact that a larger amount of particulates is deposited on the filter at the time of engine startup than during normal operation. It is possible to estimate the particulate deposition with higher accuracy. When the execution of step S15 is completed, step S16 is entered.
[0051]
On the other hand, if it is determined in step S14 that the engine is not being started, the determination result in step S14 is NO, and step S15 is not executed, and step S16 is entered.
[0052]
In step S16, based on the gear ratio data VN and accelerator opening degree data AS output from the first engine load state detection unit 8D, a value indicating the estimated accumulation amount of the particulates considering the state of the static load during operation. A certain first estimated generation amount P1 is calculated. Next, in step S17, a process of adding the first estimated generation amount P1 of particulates corresponding to the static load during operation calculated in step S16 to the count value N of the first accumulation amount counter 82A is performed. Enter S18.
[0053]
In step S18, the estimated accumulation amount of the particulates considering the variable load state during operation is shown based on the engine speed change amount data ΔN and the accelerator change amount data ΔA output from the second engine load state detecting unit 8F. A second estimated generation amount P2 that is a value is calculated. In step S19, a process of adding the second estimated generation amount P2 calculated in step S18 to the count value N that is the current particulate accumulation amount in consideration of the static load during operation calculated in step S17. The process is performed on the deposition amount counter 82A, and the process enters step S20.
[0054]
In step S20, the self-regeneration amount in the first or second filter 61, 62 is calculated for the count value N calculated in step S19. Temperature data T0 indicating the exhaust gas temperature before the filter during the operation time output from the exhaust state detection unit 8A, and time data TM0 indicating the operation time from the start of task execution to the present output from the time detection unit 8B. Based on the above, the amount of the particulates self-regenerated by heating the filter with the exhaust gas is calculated, and the estimated self-regeneration amount P4 indicating the current estimated self-regeneration amount is calculated. If the exhaust temperature is kept high enough to burn the particulates for a certain period of time, the particulates will be burned and removed by the hot exhaust gas, and the filter will self-regenerate by that amount. A value indicating the amount that the particulate is estimated to be burned is referred to as a particulate self-regeneration amount P4.
[0055]
Here, the amount of self-regeneration of the filter greatly varies depending on the amount of particulate accumulation in each filter, and the self-regeneration is promoted as the amount of air increases. In order to cope with this, a coefficient value indicating the self-regeneration efficiency set to a predetermined value in accordance with the count value N is prepared in advance in the computer. On the other hand, the self-regeneration amount is calculated from the temperature data T0 and the time data TM0, and the coefficient value and the current filter output from the air amount detection unit 8G flow into the self-regeneration amount thus obtained. The estimated self-regeneration amount P4 of the first or second filter 61, 62 can be calculated more accurately by multiplying the first or second air amount data A10, A20 indicating the air amount.
[0056]
In step S21, a process of subtracting the estimated self-regeneration amount P4 calculated in step S20 from the value of N at that time is performed on the first deposition amount counter 82A. By this processing, the value of the count value N is also taken into consideration for the decrease in particulates when the filter is self-regenerated due to the exhaust gas emission state, and the current particulate accumulation amount can be accurately estimated.
[0057]
Next, in step S22, using the count value CD, the count value DD, and the model-specific correction data Q, reference data P0 indicating the amount of particulates to be accumulated in the filter regeneration process is calculated. The reference data P0 is determined according to the number of times the filter is regenerated and the accumulated amount of incombustible ash that cannot be regenerated by the fuel additive in the filter. This is because, when an additive is added to the fuel to facilitate the self-regeneration of particulates, incombustible ash from the additive is mixed in the exhaust gas, and this incombustible ash is collected by the filter together with the particulates. This incombustible ash is deposited on the filter without being incinerated when the filter is regenerated, so that the filter is clogged and its collecting ability is reduced.
[0058]
Further, as the number of times of regeneration increases, the filter collection capability decreases as shown in FIG. 5 due to deterioration of the filter due to heat load, clogging of the filter due to incineration ash (ash), and the like, so the value of the count value CD increases. Accordingly, the value of the reference data P0 is set to be small and reproduction is performed early.
[0059]
In FIG. 5, Z is a threshold value for the number of regeneration processes set as a reference value for prompting filter replacement. In addition to a decrease in capacity due to the number of filter regeneration processes, a filter is formed by depositing non-combustible ash on the filter with additives. The degree of clogging is also taken into consideration. The weight between the degree of filter capacity reduction and the degree of clogging due to incombustible ash can be changed by an input device (not shown) of the microcomputer 81, for example.
[0060]
When the count value CD is larger than the value Z by comparing the value Z with the count value CD, the filter deterioration is performed so that the filter is appropriately replaced before the filter capacity is suddenly lowered as will be described later. The notification signal SX is output. As a result, it is possible to perform reproduction at an appropriate timing that matches the filter capability at that time, and further, by considering the model-specific correction data Q, it is possible to determine an appropriate reproduction timing that matches the engine specified at that time. .
[0061]
Returning to FIG. 4, in step S <b> 22, the accumulated use time of the filter is further output from the time detection unit 8 </ b> B in order to obtain the accumulated accumulation amount of incombustible ash accumulated on the first or second filter 61, 62. Obtained by using the time data TMO, a count value DD indicating the accumulated amount of incombustible ash deposited on the filter in proportion to the obtained accumulated use time is obtained. As in the case of the count value CD, the value of the reference data P0 is set to be smaller as the count value DD is larger, so that the reproduction is also performed earlier.
[0062]
Furthermore, by providing model-specific correction data Q, it is possible to obtain corrected reference data P0 even in accordance with engine specifications.
[0063]
The reference data P0 corresponding to the number of regeneration processes may be obtained without considering the amount of incombustible ash deposited on the filter by the additive, but here the count value DD is used to deposit the incombustible ash on the filter. The case where the amount is also taken into account is described.
[0064]
In step S23, the value of the count value N indicating the current particulate deposition amount obtained in step S21 is compared with the reference data P0 obtained in step S22, and it is determined whether N ≧ P0. . If N ≧ P0, the determination result of step S23 is YES, and the process proceeds to step S24. In step S24, a process of outputting the regeneration start signal X to the switching control unit 83 is performed so as to start the filter regeneration process, and the process proceeds to step S25.
[0065]
In step S25, a process of resetting the first accumulation amount counter 82A is performed, and then step S26 is entered. In step S26, 1 is added to the counter value of the reproduction process number counter 82C to update the number of reproduction processes. The updated value of the processing count is given as the count value CD.
[0066]
Next, in step S27, the threshold value for the number of regeneration processes according to FIG. 5 set in advance in advance in the computer according to the filter capacity reduction and the degree of clogging of the filter due to the accumulation of incombustible ash due to the additive. Z is compared with the count value CD updated in step S26, and it is determined whether or not the count value CD is equal to or greater than the reproduction processing frequency threshold value Z. If the count value CD is equal to or greater than the reproduction processing frequency threshold value Z, the determination result of step S27 is YES, and the process proceeds to step S28. In step S28, a process of outputting a filter deterioration notification signal SX is performed to prompt filter replacement, and the process proceeds to step S29.
[0067]
If N <P0 in step S23 and CD <Z in step S27, both enter step S29.
[0068]
In step S29, temperature data T0 indicating the exhaust gas temperature is compared with a preset exhaust temperature threshold value TX, and it is determined whether or not the temperature data T0 is equal to or higher than the exhaust temperature threshold value TX. If the temperature data T0 is equal to or higher than the exhaust temperature threshold value TX, the determination result in step S29 is YES, and step S30 is entered. Here, a warning signal SY for warning that the temperature data T0 is too high is displayed. The output process is performed, and the process enters step S31. If the temperature data T0 is lower than the exhaust temperature threshold value TX in step S29, step S31 is entered without executing step S30.
[0069]
In step S31, it is determined whether or not there is a request to clear the EEPROM 82D from the outside using a service tool (not shown). If there is a request to clear the EEPROM 82D, the determination result in step S31 is YES, and the process proceeds to step S32. Here, the process of resetting the respective counter values of the first accumulation amount counter 82A and the regeneration processing number counter 82C. The process proceeds to step S33. If there is no request to clear the EEPROM 82D, the determination result of step S31 is NO and the process enters step S33.
[0070]
In step S33, a process of storing the counter values of the first accumulation amount counter 82A, the second accumulation amount counter 82B, and the regeneration processing number counter 82C at that time in the EEPROM 82D and updating the value of the EEPROM 82D is performed. That is, when there is an external request to clear the EEPROM 82D in step S31, zero is stored in the EEPROM 82D as the counter value at that time of each of the first accumulation amount counter 82A and the regeneration processing number counter 82C. Become.
[0071]
Next, in step S34, the execution of the task is terminated, and then the process returns to step S13, and the execution of the task is started again.
[0072]
In the present embodiment described above, the value of the reference data P0 is set to decrease as the count value CD and the count value DD increase, thereby increasing the number of filter regenerations and increasing the fuel additive. The filter is regenerated as soon as the amount of incombustible ash deposited on the generated filter increases. However, the configuration for performing filter regeneration earlier as the number of filter regenerations increases is not limited to this one configuration example. For example, instead of resetting the accumulation amount counter 82A in step S25, which is executed immediately after step S24, the accumulation amount counter 82A calculates an initial value that increases according to the number of times the filter is regenerated, and this initial value is calculated. In step S16 executed for the first time after filter regeneration, a means for setting or adopting means for determining an initial value of the estimated generation amount according to the number of filter regenerations is adopted, while the value of the reference data P0 is set to a predetermined constant value. It may be configured so that the filter is regenerated as soon as the number of filter regeneration increases.
[0073]
Further, the configuration for regenerating the filter as soon as the amount of incombustible ash generated by the fuel additive on the filter increases is not limited to this one configuration example. For example, immediately before step S22. Then, the value of the count value DD is added to the value of the count value N, N = N + DD is performed, and a means for calculating the count value N taking into account the amount of non-combustible ash deposited on the filter is added, while in step S22 the reference data P0 is It is possible not to consider the count value DD when setting. Further, the means for calculating the count value N in consideration of the amount of non-combustible ash accumulated on the filter by performing N = N + DD is added not only immediately before step S22 but also after the task is executed and in step S22. It may be after any step as long as it is before.
[0074]
Further, in the above-described embodiment, as a regeneration means when the amount of accumulated particulates exceeds a predetermined level, a fuel combustion device 9 provided with a burner is provided, fuel is injected from the burner, and this is ignited. A configuration is employed in which the accumulated particulates are heated and burned with the heat generated by the above.
[0075]
However, the regeneration of the filter is not limited to the above-described configuration, and the regeneration may be performed using the high heat of the exhaust gas by increasing the temperature of the exhaust gas. Alternatively, post-injection may be performed by the fuel injection device, combustion heat may be generated in the engine by the post-injection, and regeneration may be performed using the high-temperature exhaust gas generated at this time. Furthermore, the exhaust gas recirculation may be performed to heat the filter to a high temperature, thereby regenerating the filter.
[0076]
The arithmetic processing for determining the reproduction start timing of the first or second filter 61, 62 has been described above with reference to FIGS. This calculation process is executed alternately with respect to the first and second filters 61 and 62. For example, when the calculation process for determining the reproduction start timing is performed on the first filter 61 in use at that time, when the reproduction start signal X is output in step S24, the second filter 62 thereafter Since the filter is switched so that the particulate collection is performed, in the next program cycle, the arithmetic processing for determining the reproduction start timing is performed on the second filter 62.
[0077]
【The invention's effect】
According to the present invention, as described above, the first calculating means calculates the estimated particulate generation amount based on the load state data indicating the engine load state and the change amount data indicating the change amount of the engine load state. Since it comprised as mentioned above, the quantity of generated particulates can be estimated accurately according to the operating state of an engine. Then, the second calculating means calculates the estimated self-regeneration amount of the particulates based on the exhaust state of the engine, and the third calculating means accumulates the estimated particulate regeneration amount and the estimated self-regeneration amount in the filter at that time. Since the amount of particulates is calculated, the amount of particulates that accurately reflects the operating state of the engine can be accurately estimated. Further, since the amount of particulates deposited on the filter can be accurately estimated without using a special sensor, there is an advantage that the cost of the apparatus is not increased. In addition, since the amount of particulate accumulation can be accurately estimated, the filter can be regenerated at an appropriate timing. As a result, the filter regeneration frequency can be suppressed without increasing the manufacturing cost, and the load on the filter can be reduced to extend the life of the filter.
[0078]
Further, according to the configuration in which the second calculating means calculates the estimated self-regeneration amount of the particulate matter in consideration of the air flow rate and / or the particulate accumulation amount in the filter in addition to the exhaust state of the engine, Accumulation amount can be estimated more accurately. Then, the determination means compares the calculation result by the third calculation means with a given reference value considering the amount of incombustible ash accumulated in the filter to determine whether or not to start regeneration of the filter. Then, the filter regeneration process can be performed at a more appropriate time.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an example of an embodiment of an exhaust gas treatment apparatus provided with a filter control device according to the present invention.
FIG. 2 is a block diagram showing a configuration of a control unit shown in FIG.
FIG. 3 is a partial flowchart showing a program for configuring the determination unit shown in FIG. 2 with a microcomputer;
4 is a remaining partial view of a flowchart showing a program for configuring the determination unit shown in FIG. 2 by a microcomputer. FIG.
FIG. 5 is a graph showing the relationship between the number of regeneration processes of a filter and the collection ability.
[Explanation of symbols]
1 Exhaust gas treatment equipment
8 Control unit
8A Exhaust state detector
8B Time detection unit
8C Start determination unit
8D first engine load state detection unit
8E Second engine load state detector
8F Environmental condition detector
8G air volume detector
81 Microcomputer
82 Judgment part
82A First accumulation amount counter
82B Second deposition amount counter
83C Playback processing counter
82D EEPROM
A1, A2 Air volume signal
A10, A20 First and second air volume data
AS accelerator opening data
CD, DD, N Count value
ST start judgment data
T0, T3, T4 Temperature data
TM0 time data
VN gear ratio data
ΔA Accelerator change data
ΔN Engine speed change data

Claims (13)

In the filter control device that estimates the particulate accumulation amount in the filter for collecting the particulates contained in the exhaust gas of the engine, and regenerates the filter based on the estimation result,
A first estimated generation amount calculation means for calculating an estimated generation amount of particulates based on load state data indicating the load state of the engine, and an estimated generation amount of particulates based on change amount data indicating the change amount of the load state First calculation means for calculating a particulate estimated generation amount based on an addition value of calculation results of the first and second estimated generation amount calculation means ,
Second calculating means for calculating an estimated self-regeneration amount of the particulates based on an exhaust state of the engine;
Third calculation means for calculating an estimated accumulation amount of particulates in the filter at that time in response to the first and second calculation means;
A filter control apparatus comprising: a determination unit that compares the calculation result of the third calculation unit with a given reference value to determine whether to start regeneration of the filter.   The filter control device according to claim 1, wherein the load state data includes at least data indicating an accelerator operation amount or a gear ratio of the transmission.   The filter control device according to claim 1, wherein the change amount data includes at least data indicating a change amount of an accelerator operation amount or a change amount of the engine speed.   The filter control device according to claim 1, wherein the first calculation means is configured to add a predetermined value to the estimated generation amount each time the engine is started. 2. The filter control apparatus according to claim 1, wherein the second calculation means calculates the estimated self-regeneration amount further considering the air flow rate and the particulate accumulation amount in the filter. Further comprising start determination means for determining whether or not the engine has been started, and when the first calculation means determines that the engine has been started by the start determination means, the particulate estimation at that time is generated. The filter control device according to claim 1 , wherein a predetermined value is added to the quantity. The filter control device according to claim 1, 2, 3, 4, or 6 , wherein at least the engine coolant temperature or the outside air temperature is taken into account in the calculation of the estimated particulate generation amount in the first calculation means.   7. The filter control device according to claim 1, wherein an initial value of the estimated particulate generation amount calculated by the first calculation means is determined according to the number of regeneration times of the filter.   The filter control device according to claim 1, wherein the reference value is determined according to the number of regeneration times of the filter.   The filter control device according to claim 9, wherein an alarm for prompting replacement of the filter is output when the number of regeneration times of the filter reaches a predetermined value.   2. The filter control apparatus according to claim 1, wherein the second calculation means calculates the estimated self-regeneration amount further considering the air flow rate in the filter.   2. The filter control apparatus according to claim 1, wherein the second calculation means calculates an estimated self-regeneration amount by further taking into account a particulate accumulation amount in the filter. The filter control device according to claim 9, wherein the reference value is further determined in consideration of an amount of incombustible ash accumulated in the filter.

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