JP2003278579A - Engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent battery exhaustion and accelerating failure during regeneration of a filter. <P>SOLUTION: In an engine control device of a vehicle including an exhaust emission control device for scavenging particulate matter in exhaust by a filter 16, and incinerating the scavenged particulate matter by an electric heater 18 to regenerate the filter, when a fuel increase command signal showing that the filter is under regeneration is given from a DPF controller 44, the fuel injection quantity is increased to increase the rotating speed of a diesel engine 10. Whereupon, the power generation amount of a generator driven by the diesel engine 10 is increased, so that even if filter regeneration is conducted by the electric heater 18, battery exhaustion and accelerating failure are prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in an engine provided with an exhaust gas purification device for collecting and removing particulate matter in exhaust gas by means of a filter, particularly prevents battery exhaustion and acceleration failure during filter regeneration by an electric heater. Regarding technology.

[0002]

2. Description of the Related Art Conventionally, there is known an exhaust gas purifying apparatus for collecting and removing particulate matter by a filter provided in an exhaust passage for the purpose of purifying exhaust gas discharged from an engine. In such an exhaust emission control device, the clogging of the filter progresses as the amount of trapped particulate matter increases. Therefore, for example, as disclosed in Japanese Patent Laid-Open No. 11-125109, heating means such as an electric heater is used. It is necessary to regenerate the filter by incinerating the collected particulate matter.

[0003]

However, since the electric heater consumes a large amount of electric power, the battery is exhausted in a low engine speed range where the amount of power generated by the generator is small. Therefore, if the filter is regenerated during idling such as warm-up operation, the voltage between the terminals of the battery gradually decreases, and the battery may run out. Further, during the filter regeneration, a part of the engine output is consumed by the generator, so that the load on the engine increases, and there is a possibility that acceleration failure may occur when the vehicle starts or accelerates.

In view of the above-mentioned conventional problems, the present invention increases the idle rotation speed and torque of the engine as needed during filter regeneration to increase the amount of power generated by the generator and to increase the battery power. An object of the present invention is to provide an engine control device which prevents rising and acceleration failure.

[0005]

Therefore, according to the first aspect of the invention, the filter collects the particulate matter in the exhaust gas with a filter and incinerates the collected particulate matter with an electric heater. In an engine control device equipped with an exhaust purification device that performs regeneration, regeneration determination means for determining whether or not the filter regeneration is being performed, and when it is determined by the regeneration determination means that filter regeneration is being performed, The engine control device is configured to include rotation speed increasing means for increasing the idle rotation speed and torque of the engine.

According to this structure, when it is determined that the filter regeneration is being performed by the electric heater, the idle speed and torque of the engine are increased. Therefore, the amount of power generation of the generator driven by the engine is increased, and battery exhaustion and acceleration failure during filter regeneration by the electric heater are prevented. According to a second aspect of the present invention, the rotation speed increasing means increases the fuel supply amount to the engine.

According to this structure, the amount of fuel supplied to the engine is increased during filter regeneration, so that the idle speed and torque of the engine are increased and the amount of power generation of the generator is increased. According to the invention of claim 3, a rotation speed detecting means for detecting an engine rotation speed, an opening degree detecting means for detecting an accelerator opening degree, and an operating state detecting means for detecting an operating state of engine-driven accessories. Equipped with
The rotation speed increasing means is a fuel supply amount to the engine based on the rotation speed, the accelerator opening degree and the operating state of the auxiliary machinery detected by the rotating speed detecting means, the opening degree detecting means and the operating state detecting means, respectively. It is characterized by determining.

According to this structure, the engine speed,
Since the fuel supply amount to the engine is determined based on the accelerator opening degree and the operating states of the auxiliary machinery, the fuel is supplied according to the engine operating state. For this reason, it is possible to suppress deterioration of fuel efficiency and exhaust properties due to excessive fuel supply.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows, as an example, the overall configuration of a diesel engine including an engine control device for a vehicle according to the present invention. Exhaust passage 1 of diesel engine 10
2 is branched into two branch passages 12a and 12b in the middle through the chamber 14, and each branch passage 12a and 1b
2b each have a substantially cylindrical filter 16 (16a and 16b) made of a porous member such as silicon carbide (SiC).
Is installed. A large number of cells that are substantially parallel to the exhaust flow are formed in the filter 16 by honeycomb-shaped partition walls, and the outlets and inlets of the cells are alternately plugged by a blocking material. Then, when the exhaust gas flows into the adjacent cells via the partition wall, the particulate matter contained in the exhaust gas is collected and removed by the partition wall. Note that the filter 16 having such a configuration generally has
It is called a "Diesel particulate filter".

On the upstream side of the filters 16a and 16b,
The electric heater 18 (1) that regenerates the filter 16 by incinerating the particulate matter collected by the filter 16
8a and 18b) are arranged respectively. That is, since most of the particulate matter is carbon (C), the electric heater 1
When the particulate matter is heated by 8, the particulate matter (C) reacts with oxygen (O ₂ ) to be discharged as harmless carbon dioxide (CO ₂ ), and a filter regeneration treatment is performed.

On the other hand, the branch passage 12 upstream of the filter 16
The solenoid valves 20 (20a and 20b) are provided in a and 12b so that one branch passage is closed and the other branch passage is opened.
Switching valve 2 such as a butterfly valve driven to open and close by
2 (22a and 22b) are respectively interposed. Further, in the intake passage 24, a compressor 26a and an intercooler 28, which form a turbocharger, are provided from the upstream side thereof, respectively. In the exhaust passage 12 on the upstream side of the chamber 14,
Turbine 2 constituting a turbocharger from the upstream side
6b and the exhaust brake device 30 are respectively installed.

Filters 16a and 16b and electric heater 1
Temperature sensors 32 (32a and 32b) for detecting the temperature T on the upstream side of the filter 16 are provided between the temperature sensors 32 and 8a and 18b, respectively. In addition, the chamber 16 includes a filter 16
Pressure sensor 3 for detecting upstream pressure (gauge pressure) Pg
4, an intake air pressure sensor 36 for detecting a supercharging pressure (absolute pressure) Pa is provided in each intake passage 24. Further, in the diesel engine 10, a rotation speed sensor 38 (rotation speed detection means) that detects an engine rotation speed (hereinafter referred to as “rotation speed”) N, and an accelerator opening sensor 40 (opening detection) that detects an accelerator opening Acc. Means) and an air conditioner as auxiliary equipment (hereinafter referred to as "air conditioner")
An air conditioner switch 42 (operating state detecting means) that outputs an ON / OFF signal indicating the operating state of each is provided.
Then, the temperature sensors 32a and 32b, the pressure sensor 3
4. Each signal of the air pressure sensor 36 and the rotation speed sensor 38 is input to the DPF controller 44 having a microcomputer built therein, and the filter regeneration process is executed by the process described later. Note that the accelerator opening sensor 40 detects the accelerator pedal position as the accelerator opening Acc.

In addition, the diesel engine 10 is equipped with an engine controller 46 for performing various controls such as fuel injection control. The engine controller 46 includes a rotation speed sensor 38, an accelerator opening sensor 4
0 and each signal from the air conditioner switch 42 and DPF
Fuel increase command signals (details will be described later) from the controller 44 are input respectively. It should be noted that the processing in the engine controller 46 realizes the reproduction determination means and the rotation speed increasing means.

Next, the control contents of the diesel engine having such a configuration will be described with reference to the flow chart. FIG. 2 shows the DPF controller 44.
The processing contents of the main routine that is repeatedly executed every predetermined time are shown. Step 0 (abbreviated as "S0" in the figure).
(The same applies hereinafter), as a default, the "reproducing" flag indicating whether or not the filter 16 is being reproduced is lowered.

In step 1, the rotational speed N, the pressure sensor 34, and the air pressure sensor 36 are used to detect the rotational speed N,
The pressure Pg and the supercharging pressure Pa are read respectively. In step 2, based on the rotation speed N, the diesel engine 1
It is determined whether 0 is rotating, that is, whether the rotation speed N is positive. And diesel engine 10
Is rotating, the process proceeds to step 3 (Yes), and if the diesel engine 10 is not rotating, the process proceeds to step 6 (No).

In step 3, it is judged whether the filter 16 is in the process of regeneration. At this time, whether or not the reproduction process is being performed is determined by the presence / absence of the "reproduction" flag. If the filter 16 is in the process of reproduction, the process proceeds to step 4 (Yes), and the subroutine (see FIG. 3) for executing the filter reproduction process is called. On the other hand, if the filter 16 is not in the regeneration process, the process proceeds to step 5 (No), and the subroutine (see FIG. 4) for executing the trapping process for trapping and removing the particulate matter in the exhaust gas is called.

In step 6 for processing when the diesel engine 10 is not rotating, since power is not being generated by the generator, power supply to the electric heater 18 is stopped in order to prevent battery consumption. FIG. 3 shows a subroutine for executing the filter regeneration process. In step 11, the temperature T on the upstream side of the filter 16 during the regeneration process is read from the temperature sensor 32.

In step 12, the current supplied to the electric heater 18 is duty-controlled in accordance with the temperature T so that the particulate matter collected by the filter 16 is efficiently incinerated. At this time, the temperature T on the upstream side of the filter 16 is controlled to be about 600 ° C. or higher within a range where the filter 16 is not thermally affected. In step 13, a fuel increase command signal is output to the engine controller 46 in order to increase the power generation amount of the generator.

In step 14, it is determined whether or not a predetermined time has elapsed since the filter regeneration process was started. When the predetermined time has elapsed, the process proceeds to step 15 (Y
es), the electric heater 18 is de-energized, and the "regenerating" flag is cleared. On the other hand, if the predetermined time has not elapsed, the process returns to step 11 (No), and the filter regeneration process is continued.

FIG. 4 shows a subroutine for executing the collecting process. In step 21, the collection amount of the particulate matter collected by the filter 16 is estimated and calculated. That is, the pressure Pg on the upstream side of the filter 16, the supercharging pressure Pa, and the rotation speed N are read from the pressure sensor 34, the air pressure sensor 36, and the rotation speed sensor 38, respectively, and the trapped amount is estimated and calculated using these as parameters. .

In step 22, it is judged whether or not the collected amount is less than or equal to the threshold value. Here, the threshold value is for determining whether or not filter regeneration should be performed, and is set to an optimum value in consideration of the characteristics of the filter 16 and the like. If the collected amount is less than or equal to the threshold value, the process proceeds to step 23 (Yes), and if the collected amount is larger than the threshold value, step 25.
Proceed to (No).

In step 23, the filter 16 is detected based on the pressure difference between the pressure Pg on the upstream side of the filter 16 and the atmospheric pressure P _0.
It is determined whether or not the pressure loss due to is less than or equal to the threshold.
Here, the threshold value is for determining whether or not to perform the filter regeneration process when the pressure loss is large even if the trapped amount of the particulate matter is small, and like the threshold value of the trapped amount. , The optimum value is set in consideration of the characteristics of the filter 16. If the pressure loss is less than or equal to the threshold value, the process proceeds to step 24 (Yes), and the power supply to the electric heater 18 is stopped. On the other hand, if the pressure loss is larger than the threshold value, the process proceeds to step 25 (No).

In step 25, the solenoid valve 20 is controlled so that the "regeneration" flag is set and the switching valve 22 on the upstream side of the filter 16 for starting the filter regeneration processing is closed and the other switching valve 22 is opened. . In step 26,
Subroutine for executing filter regeneration processing (see Fig. 3)
Is called.

According to the processing of FIGS. 2 to 4 described above,
When the amount of particulate matter collected by the filter 16 becomes larger than the threshold value, or when the pressure loss by the filter 16 becomes larger than the threshold value, the regeneration process of the filter 16 is started. Then, during the regeneration process of the filter 16, a fuel increase command signal is output from the DPF controller 44 to the engine controller 46 in order to increase the fuel injection amount and increase the generator power generation amount.

FIG. 5 shows the contents of processing that is repeatedly executed by the engine controller 46 at predetermined time intervals.
The processing shown in FIG. 5 corresponds to the rotation speed increasing means. In step 31, O from the air conditioner switch 42
Based on the N / OFF signal, it is determined whether the air conditioner is operating. If the air conditioner is operating, the process proceeds to step 32 (Yes), and if the air conditioner is not operating, the process proceeds to step 35 (No).

In step 32, the DPF controller 4
It is determined whether or not there is a fuel increase command signal from No. 4.
If there is a fuel increase command signal, the process proceeds to step 33 (Yes), and if there is no fuel increase command signal, step 3
Proceed to 4 (No). The process of step 32 corresponds to the reproduction determining means. In step 33, fuel injection control is performed when the air conditioner is operating and when the filter is being regenerated, based on the fuel injection amount map shown by the dashed line in FIG. That is, the rotation speed N and the accelerator opening Acc are read from the rotation speed sensor 38 and the accelerator opening sensor 40, respectively. Then, after the fuel injection amount Q is determined from the fuel injection amount map using the rotation speed N and the accelerator opening Acc as parameters, the fuel injection valve is drive-controlled based on the determined fuel injection amount Q. Instead of the fuel injection amount Q, the rack position of the fuel injection pump may be used (same below).

In step 34, the fuel injection control when the air conditioner is operating is executed based on the fuel injection map shown by the broken line in FIG. That is, similarly to step 33, after the fuel injection amount Q is determined from the fuel injection amount map using the rotation speed N and the accelerator opening Acc as parameters, the fuel injection valve is set based on the determined fuel injection amount Q. Drive controlled.

Here, the fuel injection amount Q when the air conditioner is operating
6 except when the accelerator opening Acc is 100%.
Since the fuel injection amount is increased from the normal fuel injection amount shown by the solid line, it is possible to prevent the rotation speed from decreasing due to the air conditioner operation. Further, since the fuel injection amount Q when the air conditioner is operating and when the filter is regenerated is further increased compared to the fuel injection amount when the air conditioner is operating, even if the filter regeneration process is performed when the air conditioner is operating, the idle rotation speed and torque are The amount of power generation increases as the price rises. For this reason, even if the electric heater 18 is energized when the air conditioner is operating, the consumption of the battery is suppressed, and the battery exhaustion and the acceleration failure can be prevented.

In step 35, the DPF controller 4
It is determined whether or not there is a fuel increase command signal from No. 4.
If there is a fuel increase command signal, the process proceeds to step 36 (Yes), and if there is no fuel increase command signal, step 3
Proceed to 7 (No). The process of step 35 corresponds to the reproduction determining means. In step 36, the fuel injection control at the time of filter regeneration is executed based on the fuel injection amount map shown by the broken line in FIG. That is, the rotation speed sensor 38
The rotation speed N and the accelerator opening Acc are read from the accelerator opening sensor 40. Then, after the fuel injection amount Q is determined from the fuel injection amount map using the rotation speed N and the accelerator opening Acc as parameters, the fuel injection valve is drive-controlled based on the determined fuel injection amount Q.

In step 37, the fuel injection control in normal time (when the air conditioner is not operating and the filter regeneration process is not performed) is executed based on the fuel injection amount map shown by the solid line in FIG. That is, similarly to step 36, after the fuel injection amount Q is determined from the fuel injection amount map using the rotation speed N and the accelerator opening Acc as parameters, the fuel injection valve is determined based on the determined fuel injection amount Q. Drive controlled.

Here, the fuel injection amount Q at the time of filter regeneration
As shown in FIG. 6, the accelerator opening Acc is 100%.
Since the amount of fuel injection is increased from the fuel injection amount at normal times except when, the amount of power generation is increased as the idle speed and torque increase, as shown in FIG. 7. Therefore, even if the electric heater 18 is energized, the consumption of the battery is suppressed, and the battery exhaustion and the acceleration failure can be prevented.

In this way, the fuel injection amount Q is determined based on the rotational speed N, the accelerator opening Acc and the air conditioner operating state, so that fuel is supplied according to the operating state of the diesel engine 10. become. For this reason,
It is possible to suppress deterioration of fuel efficiency and exhaust properties due to excessive fuel supply. The auxiliary machinery may be applied not only to the air conditioner but also to a power steering hydraulic pump or the like.

As a structure for increasing the fuel injection amount,
As shown in FIG. 8, without using the engine controller 46, an idle up device 48 including a solenoid valve and the like.
Alternatively, the fuel increase command signal from the DPF controller 44 may be input to the idle-up relay 50. In this way, the fuel injection amount can be increased by utilizing the existing idle up device 48, so that the cost increase can be suppressed as much as possible.

At this time, the idle up device 48
As shown in FIG. 9, the two idle up relays 5
0a and 50b are used to turn on / off the fuel increase command signal from the DPF controller 44 or the air conditioner switch 42.
The operation may be controlled by the FF signal. With this configuration, by simply adding the idle-up relay 50b to the idle-up circuit of the air conditioner, as shown in FIG. 10, when the accelerator opening Acc is 0% (when idle), filter regeneration or In addition, the fuel injection amount when the air conditioner is operating can be increased.

In each of the embodiments described above, it is premised that two filters 16a and 16b are provided in the exhaust passage 12, but the present invention can be applied regardless of the number of filters. Needless to say.

[0036]

As described above, according to the first aspect of the present invention, the idle speed and torque of the engine increase during filter regeneration, so the amount of power generated by the generator increases, and the battery goes up and accelerates. It is possible to prevent defects. According to the second aspect of the present invention, the fuel supply amount to the engine is increased during the filter regeneration, so the idle speed and torque of the engine increase,
The power generation amount of the generator can be increased.

According to the third aspect of the present invention, the fuel supply amount to the engine is determined based on the engine rotation speed, the accelerator opening, and the operating states of the auxiliary machinery. It is possible to suppress deterioration and deterioration of exhaust properties.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a flowchart of a main routine executed by the DPF controller.

FIG. 3 is a flowchart of a subroutine showing a filter regeneration process of the above.

FIG. 4 is a flowchart of a sub-routine showing the collection processing of the above.

FIG. 5 is a flowchart of processing executed by the engine controller.

FIG. 6 is an explanatory diagram showing an example of a fuel injection amount map.

FIG. 7 is an explanatory diagram showing an effect of the present invention.

FIG. 8 is an overall configuration diagram showing a second embodiment of the present invention.

FIG. 9 is a configuration diagram of main parts showing a third embodiment of the present invention.

FIG. 10 is an explanatory diagram showing another example of the fuel injection amount map.

[Explanation of symbols]

10 diesel engine 16 (16a, 16b) filter 18 (18a, 18b) Electric heater 38 Rotation speed sensor 40 Accelerator position sensor 42 Air conditioner switch 44 DPF controller 46 engine controller 48 Idle up device 50 (50a, 50b) Idle up relay

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 45/00 364 F02D 45/00 364A F02P 5/15 F02P 5/15 AF term (reference) 3G022 AA10 DA02 GA05 GA06 GA08 3G084 BA05 BA17 EA08 EB08 FA07 FA10 FA19 FA26 FA32 FA33 FA35 FA37 3G090 AA02 AA04 BA04 CA02 CB13 CB23 CB24 DA03 DA13 EA04 3G301 HA02 KA07 MA11 NA08 NC02 NE23 PA09Z PE01 PF03Z PF11Z PF13

Claims (3)

[Claims] 1. An engine control device equipped with an exhaust gas purification device for collecting particulate matter in exhaust gas with a filter and incinerating the collected particulate matter with an electric heater to regenerate the filter. Regeneration determining means for determining whether or not filter regeneration is being performed, and rotation speed increasing means for increasing the idle rotation speed and torque of the engine when the regeneration determination means determines that filter regeneration is being performed. An engine control device comprising: 2. The engine control apparatus according to claim 1, wherein the rotation speed increasing means increases the amount of fuel supplied to the engine. 3. A rotational speed detecting means for detecting an engine rotational speed, an opening detecting means for detecting an accelerator opening, and an operating state detecting means for detecting an operating state of an engine-driven auxiliary machine, The rotation speed increasing means is a fuel supply amount to the engine based on the rotation speed, the accelerator opening degree and the operating state of the auxiliary machinery detected by the rotating speed detecting means, the opening degree detecting means and the operating state detecting means, respectively. The engine control device according to claim 2, wherein