JP6686646B2 - Engine and control method thereof - Google Patents

Description

  The present invention relates to an engine and a control method thereof, and more particularly, to an engine and a control method thereof that reduce running costs.

  A device for reducing running cost related to an engine has been proposed (for example, refer to Patent Document 1). This device delays the injection timing of the main fuel that burns in the cylinder when the unit price of the reducing agent that reduces the nitrogen oxides in the exhaust gas becomes high, so that the nitrogen oxides in the exhaust gas Emissions are decreasing. That is, the running cost is reduced by increasing the consumption of the main fuel and suppressing the consumption of the reducing agent.

  On the other hand, the discharge amount of the nitrogen oxides and the discharge amount of the particulate matter discharged to the exhaust passage due to the combustion of the main fuel have a relationship in which one increases and the other decreases. Therefore, in the above-described control, the regeneration frequency of the collection filter increases as the emission amount of the particulate matter increases. The consumption of the regenerating fuel used for regenerating the collection filter is not uniform because it changes depending on the operating condition of the engine, the condition of the traveling path, and the like.

  However, in the above device, when calculating the running cost, the consumption of the regeneration fuel is treated as a constant value with respect to the consumption of the main fuel. Therefore, there is a case where the actual consumption amount of the fuel varies and the accurate running cost cannot be achieved, but rather the running cost increases.

JP, 2015-42855, A

  An object of the present invention is to provide an engine and a control method thereof that reduce the total running cost of the main fuel, the regenerating fuel, and the reducing agent, respectively.

  An engine of the present invention that achieves the above object is a fuel injection valve for injecting a main fuel and a regenerating fuel, an oxidation catalyst disposed in an exhaust passage through which exhaust gas generated by combustion of the main fuel passes, and a collection filter. A reducing agent injection valve and a selective reduction catalyst, which outputs a driving force by the combustion of the main fuel injected from the fuel injection valve, and the selective agent is generated by the reducing agent injected from the reducing agent injection valve. A configuration in which nitrogen oxides in exhaust gas are reduced by a reduction catalyst, and particulate matter trapped by the trapping filter is removed by oxidation of the regeneration fuel injected from the fuel injection valve in the oxidation catalyst for regeneration. In the engine, the unit price acquisition device that acquires the fuel unit price and the reducing agent unit price, and the control that is connected to the unit price acquisition device and adjusts the injection of each of the fuel injection valve and the reducing agent injection valve are performed. And a control device, for each preset section or period, by the control device, the fuel unit price and the reducing agent unit price, and the main fuel consumption amount, reducing agent consumption amount accumulated in the section or period, And, based on the total fuel consumption in the section or period calculated from the fuel consumption for regeneration, set the target total fuel consumption to be less than the total fuel consumption, based on the set target total fuel consumption, the next section or period It is configured to adjust the injection of each of the fuel injection valve and the reducing agent injection valve in.

  The total fuel consumption is the sum of the product of the main fuel consumption and the fuel unit price, the product of the regeneration fuel consumption and the fuel unit price, and the product of the reducing agent consumption and the reducing agent unit price.

  The engine control method of the present invention to achieve the above object is to inject main fuel from a fuel injection valve to output a driving force, and exhaust gas generated by combustion of the main fuel is an oxidation catalyst, a collection filter, And the selective reduction catalyst, in order to collect the particulate matter by the collection filter, the selective reduction catalyst reduces the nitrogen oxides by the reducing agent injected from the reducing agent injection valve. A method of controlling an engine for purifying and injecting regenerating fuel from the fuel injection valve, oxidizing the regenerating fuel with the oxidation catalyst to remove particulate matter accumulated on the collection filter, and regenerating , When the preset section or period ends, the main fuel consumption amount, the reducing agent consumption amount, and the regeneration fuel consumption amount consumed in the section or period are calculated, and the fuel unit price and the reducing agent unit price acquired in advance are calculated. , And before Based on the main fuel consumption amount, the regeneration fuel consumption amount, and the reducing agent consumption amount, calculate the total fuel consumption in the section or period, set the target total fuel consumption to be less than or equal to this total fuel consumption, and in the next section or period. The method is characterized by adjusting the respective injections in the fuel injection valve and the reducing agent injection valve based on the target total fuel consumption.

  According to the present invention, the actual total fuel consumption including the fuel consumption for regeneration is calculated for each preset section or period, and the target total fuel consumption for the next section or period is set so as to be equal to or less than the total fuel consumption. Since it is updated, the difference between the actual total fuel consumption and the target total fuel consumption due to the increase or decrease in the amount of fuel consumption for regeneration can be corrected in the next section or period. This is advantageous for suppressing the deviation between the target total fuel consumption and the actual total fuel consumption, and the target total fuel consumption effective for reducing the running cost can be set. Along with this, it is possible to reduce the total true running cost of the main fuel that contributes to driving, the reducing agent that contributes to purification of nitrogen oxides, and the regeneration fuel that contributes to regeneration of the collection filter.

It is explanatory drawing which illustrates embodiment of the engine of this invention. It is a 1st flowchart which illustrates embodiment of the control method of the engine of this invention. It is the map data in which the target total fuel consumption and the target emission amount are set based on the price ratio. It is a 2nd flowchart which illustrates embodiment of the control method of the engine of this invention. It is a relationship diagram which illustrates the relationship between the inlet temperature of a selective reduction catalyst, and a reduction rate. It is map data which illustrates the relationship between the inlet temperature of a selective reduction catalyst, and a correction amount. It is map data which illustrates the result of the control method of FIG. It is a 3rd flowchart which illustrates embodiment of the control method of the engine of this invention. 9 is a flow diagram illustrating some of the steps of FIG. 8. It is a relationship diagram which illustrates the relationship between the discharge amount of nitrogen oxides and the discharge amount of particulate matter. It is map data which illustrates the result of the control method of FIG.

  Embodiments of the engine and the control method thereof according to the present invention will be described below.

  The engine 10 of the embodiment illustrated in FIG. 1 includes an engine body 13 having a plurality of cylinders 11 and a fuel injection valve 12 arranged in series, and exhaust gas G generated by combustion of fuel passes through an exhaust manifold 14. And an exhaust passage 15 that is discharged. An oxidation catalyst 16, a collection filter 17, a reducing agent injection valve 18, and a selective reduction catalyst 19 are arranged in the exhaust passage 15 in the flow direction of the exhaust gas G. The white arrow in FIG. 1 indicates the exhaust gas G.

The fuel injection valve 12 injects the main fuel and the regeneration fuel. The main fuel is a fuel that burns in the cylinder 11 and contributes to driving, and is exemplified by the fuel injected in so-called pre-injection, main injection, and after-injection. The regeneration fuel is a fuel that is not burned in the cylinder 11 and is discharged to the exhaust passage 15 in an unburned state, and is exemplified by the fuel injected by so-called post injection. The fuel injection valve 12 may be arranged, for example, in both the cylinder 11 and the exhaust passage 15, and one main fuel injection valve 12 injects the main fuel into the cylinder 11 and the other fuel injection valve 12 extends in the exhaust passage. Regeneration fuel may be injected into 15.

  The oxidation catalyst 16 has a porous structure carrying a precious metal that oxidizes hydrocarbons and carbon monoxide. The collection filter 17 is composed of a honeycomb structure in which adjacent vents are alternately sealed. The reducing agent injection valve 18 injects urea as a reducing agent. The selective reduction catalyst 19 has a porous structure in which zeolite or the like is supported.

  The oxidation catalyst 16 oxidizes hydrocarbons and carbon oxides contained in the exhaust gas G. Next, the collection filter 17 collects the particulate matter contained in the exhaust gas G. Next, the selective reduction catalyst 19 reduces the nitrogen oxides contained in the exhaust gas G by a reduction reaction with ammonia generated by the hydrolysis of urea water.

  When the amount of particulate matter collected and accumulated inside the collection filter 17 becomes large, the pressure difference between the front and rear becomes larger than a predetermined value. In such a state, the collection filter 17 is regenerated. Specifically, regeneration fuel is injected from the fuel injection valve 12. Next, the injected regeneration fuel is supplied to the oxidation catalyst 16 in an unburned state without being burned in the cylinder 11 and is oxidized. Next, the temperature of the exhaust gas G passing through the oxidation catalyst 16 rises due to the heat generated by this oxidation, and the temperature of the collection filter 17 rises. Then, the particulate matter deposited due to the temperature rise of the collection filter 17 is burned and removed.

  The engine 10 of the present invention includes a unit price acquisition device 20, a temperature acquisition device 21, a pressure difference acquisition device 22, a travel distance acquisition device 23, and a control device 24. Then, for each preset section La, the controller 24 updates the next target total fuel consumption TTCx (target emission amount Ex) based on the calculated actual total fuel consumption TCx. Further, when the inlet temperature Tx of the selective reduction catalyst 19 is lower than the activation temperature Ta, the controller 24 corrects the target emission amount Ex (target total fuel consumption TTCx) based on the inlet temperature Tx.

  The total fuel consumption TCx is the actual running cost, and is the product of the main fuel consumption Cmf and the fuel unit price UPf, the product of the regeneration fuel consumption Crf and the fuel unit price UPf, and the product of the reducing agent consumption Cu and the reducing agent unit price UPu. Is added and calculated. The target total fuel consumption TTCx is a target running cost. The target emission amount Ex is a target value of the emission amount of nitrogen oxides discharged from the engine body 13 to the exhaust passage 15.

  The unit price acquisition device 20 sequentially or periodically acquires the fuel unit price UPf and the reducing agent unit price UPu. In this embodiment, the input device is provided in a driver's cab of a vehicle (not shown) equipped with the engine 10, and each unit price is input by the driver. As the unit price acquisition device 20, for example, it is possible to communicate with a database in which the unit fuel price UPf outside the vehicle and the reducing agent unit price UPu are stored or a database on the Internet, and when each unit price fluctuates, the fluctuation can be automatically updated. Any communication device may be used.

The temperature acquisition device 21 is arranged near the inlet of the selective reduction catalyst 19 and is connected to the control device 24. The temperature acquisition device 21 detects the temperature of the exhaust gas G flowing into the selective reduction catalyst 19 (hereinafter referred to as the inlet temperature Tx). In this embodiment, the temperature acquisition device 21 is a temperature sensor that directly acquires the inlet temperature Tx. As the temperature acquisition device 21, for example, a device that indirectly acquires the inlet temperature Tx using an engine model, an exhaust gas model, or the like may be used.

  The pressure difference acquisition device 22 is connected to the control device 24 and acquires the pressure difference before and after the collection filter 17. In this embodiment, it is a pressure difference sensor that directly acquires the pressure difference before and after the collection filter 17. As the pressure difference acquisition device 22, for example, a device that estimates the deposition state of the particulate matter on the collection filter 17, such as the amount of the particulate matter deposited on the collection filter 17, may be used.

  The travel distance acquisition device 23 is connected to the control device 24 and measures the travel distance of the vehicle in which the engine 10 is mounted. In this embodiment, it is a mileage meter that detects the number of revolutions of an output shaft such as a propeller shaft (not shown) and measures the mileage of a vehicle equipped with the engine 10 based on the number of revolutions. As the travel distance acquisition device 23, for example, a navigation system that communicates with a satellite positioning system and calculates the travel distance of the vehicle may be used.

  The control device 24 is connected to each of the fuel injection valve 12 and the reducing agent injection valve 18 via a signal line indicated by a chain line in addition to the above-described devices. The control device 24 includes a CPRU that performs various types of processing, an internal storage device that can read and write programs used to perform various types of information processing and information processing results, and various interfaces.

  The control device 24 reduces the main fuel injected from the fuel injection valve 12, the main fuel consumption amount Cmf, which is the cumulative consumption amount of the regeneration fuel, and the regeneration fuel consumption amount Crf, and the reduction, which is the cumulative amount of the reducing agent. The agent consumption amount Cu is sequentially stored in the internal storage device. The control device 24 measures the injection time of each injection valve and integrates each consumption amount based on the time. In addition to the injection time, the pressure at the time of injection may be used to integrate the consumption amount.

  The control method of the engine 10 will be described below with reference to the flowchart and map data. The total fuel consumption TCx, the target total fuel consumption TTCx, and the target emission amount Ex calculated by this control method are sequentially stored in the internal storage device of the control device 24. The exemplified map data is created in advance by experiments or tests, stored in the internal storage device of the control device 24, and read by the control device 24 at appropriate times.

  A control method for setting the target total fuel consumption TTCx immediately after the engine 10 is started will be described with reference to the flowchart of FIG. 2 and the map data of FIG.

  When the engine 10 is started, the control device 24 acquires the fuel unit price UPf and the reducing agent unit price UPu via the unit price acquisition device 20 (S10). Next, the control device 24 determines whether or not the fuel unit price UPf and the reducing agent unit price UPu have changed (S20). When it is determined in this step that both the fuel unit price UPf and the reducing agent unit price UPu have not changed, that is, the price ratio PRx has not changed, the previous target total fuel consumption TTCx is maintained (S30). On the other hand, when it is determined that at least one of the fuel unit price UPf and the reducing agent unit price UPu has changed, the process proceeds to the next.

  Next, the control device 24 calculates the price ratio PR3 (UPu / UPf) of the fuel unit price UPf and the reducing agent unit price UPu (S40). Next, the control device 24 calculates the minimum target total fuel consumption TTC3 with reference to the calculated price ratio PR3 and the price ratio map data M1 illustrated in FIG. 3 (S50).

In the price ratio map data M1, the target total fuel consumption TTCx required to maintain the amount of nitrogen oxide released to the outside below the specified value Va is set based on the price ratio PRx. In other words, the target total fuel consumption TTCx required to purify the target exhaust amount Ex of nitrogen oxides discharged from the engine body 13 to less than the specified value Va is set. As the specified value Va, for example, a reference value defined by law may be used.

  In the price ratio map data M1, parabolas indicating a plurality of price ratios PR1 to PR4 are set. The price ratios PR1 to PR4 gradually decrease from the price ratio PR1, that is, the fuel unit price UPf is lower than the reducing agent unit price UPu. The price ratio PRx may be subdivided to provide a larger number of parabolas. The parabola indicating the price ratio PRx becomes convex toward the direction where the target total fuel consumption TTCx becomes cheaper, that is, toward the lower side in the figure. Therefore, the minimum target total fuel consumption TTCx becomes the apex (the lowest point) of the parabola indicating this price ratio PRx. The target total fuel consumption TTC1 to the target total fuel consumption TTC4 decrease from the target total fuel consumption TTC1 in order, and the target emission amount E1 to the target emission amount E4 increase from the target emission amount E1 in order.

  The control of the control device 24 when the target total fuel consumption TTCx is set is as follows. The control device 24 adjusts the injection of each of the fuel injection valve 12 and the reducing agent injection valve 18 based on the target total fuel consumption TTCx. Specifically, the control device 24 adjusts the injection of each injection valve based on the target emission amount Ex according to the target total fuel consumption TTCx.

  The target emission amount Ex of nitrogen oxides emitted from the engine body 13 and the consumption amount of the main fuel have a relationship in which one increases and the other decreases. On the other hand, the target emission amount Ex of nitrogen oxides and the consumption amount of the reducing agent have a relationship in which when one increases, the other also increases and decreases.

  When the fuel unit price UPf becomes the price ratio PR1 that becomes higher than the reducing agent unit price UPu, the control device 24 selects the target total fuel consumption TTC1 (target emission amount E1) as illustrated in FIG. That is, the control device 24 increases the consumption amount of the main fuel by delaying the injection timing of the fuel injection valve 12, and decreases the consumption amount of the reducing agent by decreasing the target emission amount E1 of nitrogen oxides. This reduces running costs.

  On the other hand, when the reducing agent unit price UPu becomes the price ratio PR4, which is higher than the fuel unit price UPf, the control device 24 selects the target total fuel consumption TTC4 (target emission amount E4). That is, the control device 24 reduces the consumption amount of the main fuel by advancing the injection timing of the fuel injection valve 12, and reduces the consumption amount of the reducing agent with respect to the increase of the target emission amount E4 of nitrogen oxides. By increasing, the running cost is reduced.

  As described above, when the engine 10 starts and at least one of the fuel unit price UPf and the reducing agent unit price UPu fluctuates, that is, when the price ratio PRx fluctuates, the minimum target total fuel consumption TTCx is updated. . As a result, it is possible to set the target total fuel consumption TTCx according to the latest price ratio PRx and reduce the running cost.

  Next, a control method for correcting the target emission amount Ex after the target emission amount Ex is set by setting the target total fuel consumption TTCx, a flowchart illustrated in FIG. 4 and maps illustrated in FIGS. It will be explained with reference to the data. Hereinafter, it is assumed that the control device 24 adjusts the injection of the fuel injection valve 12 and the reducing agent injection valve 18 based on the target emission amount E2.

  The control method illustrated in FIG. 4 is performed after the target emission amount Ex is set and before the injection of the fuel injection valve 12 and the reducing agent injection valve 18 is adjusted based on the target emission amount Ex. That is, it is performed every time the target total fuel consumption TTCx is updated.

  After updating the target total fuel consumption TTCx, the control device 24 acquires the inlet temperature T5 via the temperature acquisition device 21 (S100). Next, the controller 24 determines whether the inlet temperature T5 is lower than the activation temperature Ta (S110).

  As illustrated in FIG. 5, the reduction rate RRx of the nitrogen oxides in the selective reduction catalyst 19 decreases as the inlet temperature Tx decreases. An activation temperature Ta is set for the selective reduction catalyst 19. In the region where the inlet temperature Tx is lower than the activation temperature Ta, the selective reduction catalyst 19 cannot reduce the emission amount of nitrogen oxides below the specified value Va when the reduction rate RRx is low and the emission amount of nitrogen oxides is large. There is a risk.

  Therefore, when the inlet temperature Tx is below the activation temperature Ta, the controller 24 calculates the correction amount ΔEx based on the reduction rate RRx of the selective reduction catalyst 19 at the inlet temperature Tx (S120). Then, the correction amount ΔEx is subtracted from the target emission amount Ex to calculate the corrected emission amount CEx that makes the emission amount of nitrogen oxides released to the outside equal to or less than the preset specified value Va (S130).

  Specifically, when it is determined that the inlet temperature Tx is lower than the activation temperature Ta in the above step, the control device 24, based on the inlet temperature T5 and the inlet temperature map data M2 illustrated in FIG. The correction amount ΔE5 is calculated (S120).

  In the inlet temperature map data M2, the relationship between the inlet temperature Tx and the correction amount ΔEx is set. The correction amount ΔEx is related to the inlet temperature Tx such that one increases and the other decreases. The correction amount ΔEx is a subtraction value with respect to the target emission amount Ex of nitrogen oxides, and is set according to the reduction rate RRx of the selective reduction catalyst 19 at the inlet temperature Tx.

  Next, the controller 24 corrects the target emission amount E4 (S130). Specifically, the control device 24 subtracts the calculated correction amount ΔE5 from the target discharge amount E4 to calculate the corrected discharge amount CE5. The calculated corrected emission amount CE5 is maintained based on the reduction rate RR5 of the selective reduction catalyst 19 at the inlet temperature T5 illustrated in FIG. 5 so that the amount of released nitrogen oxides is kept below the specified value Va. It becomes a possible target value.

  As illustrated in FIG. 7, the target total fuel consumption TTC5 according to the corrected emission amount CE5 is higher than the set target total fuel consumption TTC4. On the other hand, the corrected discharge amount CE5 is smaller than the initially set target discharge amount E4 by the correction amount ΔE5.

  Next, the control device 24 adjusts the injection of the fuel injection valve 12 and the reducing agent injection valve 18 based on the corrected emission amount CE5 (S140). Specifically, the control device 24 retards the injection timing of the fuel injection valve 12 and reduces the injection amount of the reducing agent injection valve 18 as compared with the case where the control is performed based on the target emission amount E4.

  On the other hand, when the inlet temperature T6 is determined to be equal to or higher than the activation temperature Ta in the above step, the controller 24 maintains the initially set target emission amount E4 (S150). Alternatively, when the corrected emission amount CE5 has been corrected in the above step, the corrected emission amount CE5 is returned to the target emission amount E4 (S150). Next, the control device 24 adjusts the injection of the fuel injection valve 12 and the reducing agent injection valve 18 based on the target emission amount E4 (S160).

As described above, when the inlet temperature Tx of the selective reduction catalyst 19 is lower than the activation temperature Ta, the fuel unit price UPf and the reducing agent are set as the target values of the nitrogen oxide emission amount based on the inlet temperature Tx. Since the corrected emission amount CEx which is smaller than the target emission amount Ex corresponding to the unit price UPu is set, the actual emission amount of nitrogen oxides into the exhaust passage 15 can be reduced. This is advantageous for reducing the amount of nitrogen oxides that cannot be fully reduced by the selective reduction catalyst 19 that has not reached the activation temperature Ta, and the amount of nitrogen oxides released to the outside can be suppressed. Further, since the reducing agent is reduced to the consumption amount that can be consumed by the selective reduction catalyst 19, it is advantageous in suppressing the wasteful consumption amount of the reducing agent, suppressing the release of the reducing agent to the outside and reducing the running cost. It can be reduced.

  Further, since the control is performed based on the corrected discharge amount CEx which is smaller than the target discharge amount Ex, it is possible to retard the injection timing of the fuel injection valve 12 and increase the injection amount of the main fuel. This is advantageous for increasing the temperature of the exhaust gas G, and the inlet temperature Tx can be brought close to the activation temperature Ta early. With the early activation of the selective reduction catalyst 19, the target emission amount Ex more effective in reducing the running cost than the corrected emission amount CEx can be promptly returned.

  In this embodiment, by performing the above-described control until the injection of the fuel injection valve 12 and the reducing agent injection valve 18 is adjusted based on the set target emission amount Ex, before the injection of each injection valve. Can be corrected to. This is advantageous for suppressing discharge of nitrogen oxides that cannot be completely reduced to the exhaust passage 15, and can suppress discharge of nitrogen oxides to the outside. In particular, it is effective when the engine 10 is started on a cost basis from a state where the ambient temperature is low.

  In this embodiment, the correction amount ΔEx based on the reduction rate RRx of the selective reduction catalyst 19 at the inlet temperature Tx is calculated, and the calculated correction amount ΔEx from the target emission amount Ex is subtracted. It can be surely suppressed. This is advantageous in suppressing the release of the reducing agent to the outside and reducing the running cost of the reducing agent.

  The target total fuel consumption TTCx and the target emission amount Ex of nitrogen oxides Ex have a relationship in which when one increases, the other also increases. Therefore, in the above control, the target total fuel consumption TTCx may be corrected instead of correcting the target emission amount Ex.

  Next, the control for updating the target total fuel efficiency TTCx for each predetermined section La after the target total fuel efficiency TTCx is set will be described with reference to the flowchart illustrated in FIG. 8. Hereinafter, it is assumed that the control device 24 adjusts the injection of the fuel injection valve 12 and the reducing agent injection valve 18 based on the target total fuel consumption TTC2 (target emission amount E2). Further, it is assumed that the control device 24 sequentially integrates the consumption amounts of the main fuel, the regenerating fuel, and the reducing agent immediately after the engine 10 is started.

  As illustrated in FIG. 8, the control device 24 adjusts the injection of the fuel injection valve 12 and the reducing agent injection valve 18 based on the set target total fuel consumption TTC2 (target emission amount E2) (S200). Next, the control device 24 acquires the traveling distance Lx of the vehicle via the traveling distance acquisition device 23 (S210). Next, the control device 24 determines whether or not the acquired travel distance Lx is equal to or longer than the preset section La (S220).

  The section La is set in advance and is a section from the setting of the target total fuel consumption TTC2 to the number of times n of regeneration of the collection filter 17 becomes a plurality of times. The section La may be at least a section including a section from the number of times n of regeneration of the collection filter 17 is zero to a plurality of times. The control device 24 may determine whether or not the traveling distance Lx has reached the section La, and may also determine whether or not the number of times of regeneration n of the collection filter 17 is a plurality or more at the traveling distance Lx.

  In this step, when it is determined that the traveling distance Lx has not reached the section La, the control based on the target total fuel consumption TTC2 is continued. On the other hand, when it is determined that the traveling distance Lx has reached the section La, the target total fuel consumption TTC2 is updated.

  Next, the control device 24 calculates the main fuel consumption amount Cmf, the regeneration fuel consumption amount Crf, and the reducing agent consumption amount Cu, which are integrated values of the consumption amount in the section La (S230). Next, the control device 24 controls the fuel unit price UPf and the reducing agent unit price UPu acquired through the unit price acquiring device 20 and the accumulated main fuel consumption amount Cmf, regeneration fuel consumption amount Crf, and reducing agent consumption. The actual total fuel consumption TC2 in the section La is calculated based on the amount Cu (S240). Next, the control device 24 updates the target total fuel consumption TTC7 that is equal to or less than the total fuel consumption TC2 with reference to the total fuel consumption TC2 (S250). After updating to the target total fuel consumption TTC7, the process returns to the start and the above steps (S200 to S250) are repeated for each section La.

  The steps from the calculation of the total fuel consumption TCx (S240) to the updating of the target total fuel consumption TTCx (S250) will be described with reference to the flowchart illustrated in FIG. 9 and the map data in FIGS. 10 and 11.

  The control device 24 determines the target total fuel consumption TTCx based on the increase / decrease in the main fuel consumption Cmf and the reducing agent consumption Cu when it is assumed that the regeneration fuel consumption Crf in the section La is increased / decreased with reference to the total fuel consumption TCx. To calculate.

  As illustrated in FIG. 9, the control device 24 decreases the accumulation amount Q2 by the increase / decrease amount ΔQ, assuming that the regeneration fuel consumption amount Crf is decreased in the section La (S241). Next, the control device 24 calculates the target emission amount E7 which is increased from the target emission amount E2 by the increase / decrease amount ΔE (S243).

  As illustrated in FIG. 10, the target emission amount Ex of nitrogen oxides discharged from the engine body 13 and the deposition amount Qx of the particulate matter deposited on the collection filter 17 (the particulate matter discharged from the engine body 13 Emission amount), the relationship is such that when one increases, the other decreases. That is, assuming that the regeneration fuel consumption amount Crf in the section La is increased, the deposition amount Qx increases while the target emission amount Ex decreases. On the contrary, if it is assumed that the regeneration fuel consumption amount Crf in the section La is decreased, the accumulation amount Qx is decreased and the target emission amount Ex is increased.

  The control device 24 uses, as the increase / decrease amount ΔQ, an amount that can increase / decrease the number of times of regeneration n of the collection filter 17 in the section La by one time. That is, the controller 24 assumes that the collection filter 17 is set to the number of times of regeneration (n-1) in the section La, and the accumulated amount Q2 is removed by one time of regeneration of the collection filter 17 (ΔQ ) Only decreases. Decreasing the accumulation amount Q2 increases the target emission amount E2. The number of times of increase / decrease in the number of times n of the collection filter 17 to be reproduced may be increased or decreased once or more.

  Next, the control device 24 calculates the target total fuel consumption TTC7 according to the calculated target emission amount E7 (S245). Specifically, as illustrated in FIG. 11, the control device 24 calculates the target total fuel consumption TTC7 that becomes the target emission amount E7 in the price ratio PR2 of the price ratio map data M1. Next, the control device 24 determines whether or not the calculated target total fuel consumption TTC7 is equal to or less than the total fuel consumption TC2 (S247). If it is determined in this step that the target total fuel consumption TTC7 exceeds the total fuel consumption TC2, the process returns to the step of increasing or decreasing the accumulation amount Qx.

  On the other hand, when it is determined that the target total fuel consumption TTC7 is equal to or less than the total fuel consumption TC2, the process proceeds to the next. Next, the control device 24 calculates the target total fuel consumption TTC7 determined to be equal to or less than the total fuel consumption TC2 as a new target total fuel consumption TTCx (S249).

  As illustrated in FIG. 11, the total fuel consumption TC2 calculated in the above step (S240) becomes higher than the target total fuel consumption TTC2 by the fuel consumption for regeneration obtained by multiplying the regeneration fuel consumption amount Crf by the fuel unit price UPf. . On the other hand, the newly calculated target total fuel consumption TTC7 is lower than the total fuel consumption TC2 although the target emission amount E7 is increased.

The control device 24 adjusts the injection of the fuel injection valve 12 and the reducing agent injection valve 18 based on the updated target total fuel consumption TTC7 (target emission amount E7) (S200).

  In this embodiment, an example in which the target total fuel consumption TTCx is equal to or less than the total fuel consumption TCx when the deposition amount Qx is reduced has been described. However, when the deposition amount Qx is assumed to be increased, the target total fuel consumption TTCx is reduced. May be less than the total fuel consumption TCx. Therefore, it is preferable to repeatedly increase and decrease the accumulation amount Qx to calculate the target total fuel consumption TTCx that is equal to or less than the total fuel consumption TCx. When the increase / decrease in the accumulated amount Qx is repeated a plurality of times, the increase / decrease amount ΔQ may be gradually increased or decreased.

  By performing the control as described above, the total fuel consumption TCx including the regeneration fuel consumption amount Crf is calculated for each preset section La, and the target total fuel consumption TTCx that is equal to or less than the total fuel consumption TCx is updated. The deviation between the actual total fuel consumption TCx and the target total fuel consumption TTCx due to the increase or decrease in the regeneration fuel consumption amount Crf can be corrected in the next section. This is advantageous for suppressing the deviation between the target total fuel consumption TTCx and the actual total fuel consumption TCx, and the target total fuel consumption TTCx effective for reducing the running cost can be set. Accordingly, the total true running cost of the main fuel that contributes to driving, the reducing agent that contributes to purification of nitrogen oxides, and the regeneration fuel that contributes to regeneration of the collection filter 17 can be reduced.

  In this embodiment, the target total fuel consumption TTCx is calculated on the assumption that the regeneration fuel consumption amount Crf is increased or decreased on the basis of the calculated total fuel consumption TCx for each section La, and therefore the regeneration fuel consumption amount is unexpectedly exceeded. Even if Crf increases or decreases, the target total fuel consumption TTCx that is effective in reducing the running cost can be corrected and updated, which is advantageous in reducing the total running cost.

  In this embodiment, the section La is set to a section from when the target total fuel consumption TTCx is set to when the collection filter 17 is regenerated a plurality of times, so that the operating state of the engine 10 according to the driver and The condition of the road on which the vehicle travels can be reflected in the target total fuel consumption TTCx. This is advantageous for reducing the total running cost in consideration of the driving condition and the traveling condition.

  Since one of the accumulated amount Qx and the target emission amount Ex increases, the other decreases, so that the increase / decrease amount ΔQ and the increase / decrease amount ΔE both increase and decrease. Therefore, in the above steps (S241, S243), a new target emission amount Ex may be calculated on the assumption that the set target emission amount Ex has been increased or decreased based on the total fuel consumption TCx.

  The target total fuel consumption TTCx and the target emission amount Ex of nitrogen oxides Ex have a relationship in which when one increases, the other also increases. Therefore, in the above control, instead of the target total fuel consumption TTCx, the injection of the fuel injection valve 12 and the reducing agent injection valve 18 may be adjusted based on the target emission amount Ex.

  As described above, the engine 10 of the present invention does not follow a simple cost base, but changes in the reduction rate RRx of the selective reduction catalyst 19 due to the inlet temperature Tx and the regeneration fuel consumption amount Crf for each section La. Since the target total fuel consumption TTCx is sequentially updated based on the variation, the actual total running cost can be reduced. That is, the true running cost, which is the total cost of the device for purifying the exhaust gas G and the cost of driving the engine 10, can be reduced. Further, it is possible to surely suppress the release of the reducing agent or the nitrogen oxide generated on a simple cost basis to the outside.

  In the above-described embodiment, the step of acquiring the fuel unit price UPf and the reducing agent unit price UPu is performed at the time of starting the engine 10. However, for example, the fuel unit price UPf and the reducing agent unit price UPu are only obtained when the fuel and the reducing agent are replenished. The step of obtaining may be performed.

  Further, instead of the travel distance acquisition device 23, a timer that counts the travel time or the drive time of the engine 10 may be used. When the timer is used, the step of updating the target total fuel consumption TTCx for each preset period is replaced with the step of updating the target total fuel consumption TTCx for each section La. The period may be a period corresponding to the time for traveling in the section La, and may be a period including at least the period from the number of times n of regeneration of the collection filter 17 is zero to a plurality of times.

10 engine 12 fuel injection valve 15 exhaust passage 16 oxidation catalyst 17 collection filter 18 reducing agent injection valve 19 selective reduction catalyst 20 unit price acquisition device 21 temperature acquisition device 24 controller TCx total fuel consumption TTCx target total fuel consumption

Claims (6)

A fuel injection valve for injecting a main fuel and a regenerating fuel, an oxidation catalyst arranged in an exhaust passage through which exhaust gas generated by combustion of the main fuel passes, a collection filter, a reducing agent injection valve, and a selective reduction catalyst A driving force is output by combustion of the main fuel injected from the fuel injection valve, and the reducing agent injected from the reducing agent injection valve reduces nitrogen oxides in the exhaust gas with the selective reduction catalyst. Then, in the engine configured to remove and regenerate the particulate matter collected by the collection filter by the oxidation in the oxidation catalyst of the regeneration fuel injected from the fuel injection valve,
A unit price acquisition device that acquires a fuel unit price and a reducing agent unit price, and a control device that is connected to the unit price acquisition device and that controls the injection of each of the fuel injection valve and the reducing agent injection valve,
The fuel unit price and the reducing agent unit price, and the main fuel consumption amount, the reducing agent consumption amount, and the regeneration fuel consumption amount accumulated in the section or period by the control device for each preset section or period. Based on the total fuel consumption in the section or period calculated from, set the target total fuel consumption to be equal to or less than the total fuel consumption, based on the set target total fuel consumption, the fuel injection valve in the next section or period and the An engine having a configuration in which each injection of the reducing agent injection valve is adjusted.   Based on the increase / decrease in the main fuel consumption amount and the reducing agent consumption amount when it is assumed that the regeneration fuel consumption amount in the section is increased or decreased based on the total fuel consumption, The engine according to claim 1, wherein the target total fuel consumption is calculated as follows. The control device, according to the price ratio of the fuel unit price and the reducing agent unit price, price ratio map data in which the relationship between the target emission amount of nitrogen oxides discharged to the exhaust passage and the target total fuel consumption is set. Have,
Based on the total fuel consumption, the control device calculates the target total fuel consumption that is equal to or less than the total fuel consumption based on the price ratio in the price ratio map data and the increase / decrease in the target emission amount. The engine according to claim 1 or 2.   When at least one of the fuel unit price and the reducing agent unit price fluctuates, based on the fuel unit price and the reducing agent unit price acquired by the unit price acquiring device and the price ratio map data, the controller makes the minimum. The engine according to claim 3, wherein the target total fuel consumption is set.   5. The section according to claim 1, wherein the section is set to a section including a section from when the target total fuel consumption is set to at least a number of times when the collection filter is regenerated a plurality of times. engine. The main fuel is injected from the fuel injection valve to output a driving force, and the exhaust gas generated by the combustion of the main fuel is passed through the oxidation catalyst, the collection filter, and the selective reduction catalyst in this order, and the collection filter. In addition to collecting the particulate matter with the selective reduction catalyst, the reducing agent injected from the reducing agent injection valve reduces and purifies nitrogen oxides and injects regeneration fuel from the fuel injection valve. In the engine control method, the regeneration fuel is oxidized by the oxidation catalyst to remove particulate matter deposited on the collection filter, and the regeneration is performed.
When a preset section or period ends, the main fuel consumption amount, the reducing agent consumption amount, and the regeneration fuel consumption amount consumed in the section or period are calculated,
Based on the fuel unit price and the reducing agent unit price acquired in advance, and the main fuel consumption amount, the regeneration fuel consumption amount, and the reducing agent consumption amount, calculate the total fuel consumption in the section or period,
Set the target total fuel efficiency below this total fuel efficiency,
A method for controlling an engine, comprising adjusting the respective injections of the fuel injection valve and the reducing agent injection valve based on the target total fuel consumption in the next section or period.