JP4840397B2 - Fuel injection amount learning control device - Google Patents

Description

  The present invention relates to a fuel injection amount learning control device that is mounted on an internal combustion engine such as a diesel engine and executes a learning operation for appropriately obtaining a fuel injection amount from a fuel injection valve. In particular, the present invention relates to an improvement for efficiently completing a learning operation.

  Conventionally, as disclosed in Patent Document 1 below, for example, in an internal combustion engine such as an automobile diesel engine, an extremely small amount of fuel is required prior to main injection for the purpose of reducing combustion noise and NOx emissions. Pilot injection is performed to inject fuel into the cylinder.

In an engine that performs such pilot injection, the optimum value of the pilot injection amount differs depending on the operating state of the engine at that time. In general, the pilot injection amount is approximately several mm ³ depending on the cylinder capacity of the engine, and the pilot injection is executed with a target pilot injection amount obtained based on the engine speed or the like. Specifically, open / close control (control of valve opening time) of a fuel injection valve (hereinafter also referred to as an injector) is performed according to the fuel injection pressure.

  The problem here is the variation in fuel injection amount (individual variation) due to individual differences in the fuel injection system and the change in fuel injection amount over time. In other words, individual differences (injection amount variation) and individual differences (variation in sensor output) among the sensors used in the fuel injection system, and changes in injector characteristics over time (degradation of the injector) A deviation occurs between the target pilot injection amount obtained by a computer or the like and the actual pilot injection amount actually injected, and if such a deviation occurs, an appropriate pilot injection amount cannot be obtained. Become. In a situation where the actual pilot injection amount is significantly deviated from the target pilot injection amount, there is a possibility that combustion noise increases, PM (Pattern Matter) emission increases, engine misfires, etc. occur. Not only that, but also with this deviation in the fuel injection amount, there is a concern that the drivability deteriorates, white smoke is generated in the exhaust, and the fuel consumption rate deteriorates.

  For this reason, conventionally, for example, a pilot injection amount learning operation as disclosed in Patent Document 2 below has been performed. Patent Document 2 discloses a pilot injection amount learning operation in a common rail type diesel engine. As described above, in the pilot injection, the fuel injection at the target pilot injection amount is executed by appropriately setting the valve opening time of the injector according to the fuel injection pressure. For this reason, the engine ECU provided in the engine control system has a pilot injection amount and an energization time (open) for each of multiple stages (for example, four stages) of common rail pressure (for example, 30 MPa, 60 MPa, 90 MPa, and 120 MPa). The pilot injection amount setting map in which the relationship with the valve time is stored for each cylinder (for each injector) is stored. That is, the energization time to the injector according to the common rail pressure is obtained according to the pilot injection amount setting map so that the target pilot injection amount determined according to the engine speed or the like can be obtained. For example, in a four-cylinder engine, when learning is performed for each of four stages of common rail pressure, 16 learning values (map values) are stored in the pilot injection amount setting map.

  The learning operation of the pilot injection amount is performed by appropriately correcting the learning value on the pilot injection amount setting map, so that proper pilot injection can be performed even if individual variations of the fuel injection system or changes in the injection amount occur over time. This is to enable pilot injection with a quantity.

  Specifically, as this learning operation, there is no injection when the command injection amount to the injector is less than or equal to zero (for example, when the accelerator opening becomes “0” during traveling: in a vehicle equipped with a manual transmission) A very small amount of fuel equivalent to the pilot injection amount is injected toward a specific cylinder (a cylinder whose piston is near top dead center) during a shift-up operation (hereinafter referred to as “single injection”). ), The amount of change in the engine speed associated with this single injection (the amount of change in the engine operating state) is recognized. Then, the change amount data of the engine operation state when the single injection of a predetermined amount is executed accurately is compared with the change amount of the engine operation state when the single injection is actually performed, and according to the deviation amount The learning value of the pilot injection amount setting map is corrected. Such an operation is executed for each common rail pressure and each cylinder on the pilot injection amount setting map so that pilot injection can be performed with an appropriate pilot injection amount for all cylinders regardless of the common rail pressure. I have to.

  FIG. 9 shows a case where a learning value for correcting a change in the fuel injection amount due to the deterioration of the injector over time is acquired. From the upper stage, the deterioration degree of the injector, the injection amount accuracy of the injector, and the change in the learning value are respectively shown. Show. As shown in FIG. 9, although the deterioration of the injector progresses as the mileage of the vehicle increases (see the waveform indicating the degree of deterioration of the injector), the learning operation is performed at a predetermined interval (injection accuracy of the injector). The learning value is updated (see the waveform representing the learning value), so that the injection amount accuracy of the injector can be appropriately obtained. The guaranteed injection amount accuracy line in the figure defines the allowable limit value for the deterioration of the injection amount accuracy of the injector, and the learning operation is performed so that the injection amount accuracy of the injector does not exceed the guaranteed injection amount accuracy line. Performed regularly. As the execution timing of this learning operation, when the vehicle has traveled a predetermined travel distance from the previous learning operation execution time, the learning mode is entered, and in this mode, the command injection amount to the injector is zero or less. (For example, during a shift-up operation of a vehicle equipped with a manual transmission).

FIG. 10 is a timing chart showing an example of the execution timing of this learning operation, and shows changes in the vehicle speed, engine speed, and injector injection amount from the top. As can be seen from FIG. 10, the accelerator opening temporarily becomes “0” and the fuel injection amount becomes “0” during traveling, such as during a shift-up operation while the vehicle is traveling (at the same time, the clutch is also turned on). At the timing when the engine is cut off, the single injection is performed once while the engine speed is decreasing (the injection amount of this single injection is extremely small, so it does not appear in the injection amount waveform of FIG. 10). ), The learning value is acquired by recognizing the amount of change in the engine operating state at that time, and the pilot injection amount setting map is corrected. In FIG. 10, the command injection amount to the injector is “0” at each timing t <b> 1 to t <b> 6 in the drawing, and a learning operation is performed by performing a very small amount of fuel injection (single injection) here. Executed.
JP 2003-56389 A JP 2005-36788 A

  By the way, as described above, the learning value obtained by the learning operation of the pilot injection amount is stored in the engine ECU and is updated every time a new learning value is obtained. If the engine ECU is replaced at a car dealer or a repair shop, the learned value on the pilot injection amount setting map is lost, and pilot injection at an appropriate pilot injection amount cannot be performed.

  In such a situation, after replacing the engine ECU, the user travels the vehicle for a predetermined distance (after traveling for a predetermined distance, which is one of the learning operation execution conditions), and the accelerator opening is temporarily “ Until the learning operation execution condition is satisfied and a new learning value is acquired, control of the fuel injection amount that reflects individual differences in the fuel injection system and changes in the injection amount over time is performed. It becomes impossible to do. That is, the fuel injection amount cannot be corrected based on the learned value, and the traveling in the state where the actual pilot injection amount is significantly deviated from the appropriate amount is continued.

  FIG. 11 shows changes in the degree of deterioration of the injector, the injection amount accuracy of the injector, and the learning value when the engine ECU is replaced, and shows the case where the engine ECU is replaced at the timing tc in the figure. .

  As shown in FIG. 11, before the engine ECU is replaced, the learning operation is performed at a predetermined interval, and the learning value is updated, so that the injection amount accuracy of the injector can be appropriately obtained (in the drawing). (See the learning timing indicated by ta and tb).

  However, when the engine ECU is replaced at the timing tc in the figure and the learning value does not exist on the pilot injection amount setting map, the period until the next learning operation execution timing (timing td in the figure) (in the figure) In the period te), the learning value is “0”, and the injection amount accuracy of the injector is the fuel along the injector deterioration line, that is, the fuel is injected without correction according to the deterioration of the injector or the like. It will be broken. In other words, the deterioration or the like of the injector is directly reflected in the fuel injection amount, and the injection amount accuracy of the injector exceeds the guaranteed injection amount accuracy line, so that an appropriate fuel injection amount cannot be obtained. In such a situation, the above-described problems such as deterioration of drivability and generation of white smoke in the exhaust are caused.

  Then, when the learning operation execution condition is satisfied and the learning operation is executed after that, the learning operation is completed at the timing td in the figure. Therefore, only one learning operation was performed at the timing when the accelerator opening temporarily became “0” during traveling. Therefore, in order to complete the learning for each cylinder (for each injector) for each of the above-described common rail pressures (to obtain all 16 learning values as described above), it is very important. It took a long time, and during that time, there was a possibility that the situation causing the problems such as the deterioration of the drivability and the generation of white smoke in the exhaust gas could be continued. More specifically, the learning operation is executed about 10 times for one common rail pressure and one cylinder combination, and the average value of these learning values is reflected in the pilot injection amount setting map. Actually, for example, if the learning operation is not performed about 160 times, all the learned values on the pilot injection amount setting map are not properly obtained.

  As described above, the learning operation (single injection) when the accelerator opening temporarily becomes “0” while the vehicle is traveling is executed only once. In spite of the degree being “0”, the fuel injection (single injection) is performed from the injector. Therefore, the accelerator opening is temporarily set to “0” during the normal running by such a user. This is because if the fuel injection is performed a plurality of times at the same timing, the combustion noise becomes loud and the user may feel uncomfortable. That is, the conventional technical idea does not assume that the learning value is lost due to, for example, replacement of the engine ECU, and the learning value acquired before is used even if the learning frequency is relatively low. As a result, the fuel injection amount is learned based on the idea that the user does not feel uncomfortable due to the increase in the combustion noise. It was broken.

  In the above description, the pilot injection amount learning of the diesel engine has been described. However, the same problem may occur in the learning operation of the main injection amount and the learning operation of the fuel injection amount of the gasoline engine.

  The present invention has been made in view of such a point, and the object of the present invention is to obtain the latest learning value as soon as possible even when the learning value disappears due to replacement of the engine ECU or the like. An object of the present invention is to provide a fuel injection amount learning control device that can perform the above-described operation.

-Principle of solving the problem-
The solution principle of the present invention taken in order to achieve the above object is to shift to a mode in which the fuel injection amount learning operation is forcibly executed when the learned value disappears, for example, when the engine ECU is replaced. Then, the learning operation is completed in a short period of time so that fuel injection can be performed at a fuel injection amount according to an appropriate learning value at an early stage.

-Solution-
Specifically, the present invention performs fuel injection from a fuel injection valve into a specific cylinder of a vehicle internal combustion engine when an execution condition for a fuel injection amount learning operation is satisfied, and the operation of the internal combustion engine accompanying the fuel injection A fuel injection amount learning control device that executes a fuel injection amount learning operation for acquiring a learning value based on a deviation of an actual fuel injection amount from a target fuel injection amount from a change in state is assumed. A learning operation for forcibly executing a fuel injection amount learning operation for acquiring the learning value even when the execution condition is not satisfied when the learning value disappears for the fuel injection amount learning control device Forced execution means are provided. Then, when the learned value is lost, the learning operation forcible execution means is used when the accelerator opening associated with the driving operation for ensuring a long state of setting the accelerator opening to “0” becomes “0” or the fuel The fuel injection amount learning operation is forcibly executed when the command injection amount to the injection valve becomes less than or equal to zero, and when the fuel injection amount learning operation is forcibly executed, the accelerator opening is set to “0”. ”Or when the command injection amount to the fuel injection valve becomes less than or equal to zero, the engine speed is recognized, and the learning is performed in a period from when the engine speed decreases to the idle speed. The number of possible executions of injection is calculated, and a plurality of learning values are acquired by intermittently executing the calculated number of single injections during that period.

  According to this specific matter, for example, after the ECU mounted on the vehicle is replaced with a new one, the fuel injection amount learning operation is forcibly executed to acquire the learning value, which is stored in the ECU before replacement. A learning value equivalent to the learning value that has been stored can be acquired in a short period of time and stored in a new ECU. More specifically, it is not necessary for the user to travel a relatively long distance after replacing the ECU (without having to wait for the execution condition of the learning operation by driving the vehicle for a long distance). A dealer or the like forcibly shifts to the learning operation execution mode, and by executing this learning operation, an appropriate learning value can be obtained in a short period of time, and when the vehicle is delivered to the user, an appropriate fuel injection amount is obtained. Can be a thing.

  Specific examples of the fuel injection amount learning operation forcibly executed by the learning operation forcible execution means include the following.

  First, the learning operation forced execution means receives a forced learning command signal from a transmission means (tool) for transmitting a learning operation forced execution command so as to shift to the learning mode and forcibly execute the fuel injection amount learning operation. To.

  In this case, after receiving the forced learning command signal from the transmitting means, the fuel injection amount learning operation is forcibly executed when the fuel injector does not inject while the vehicle is running.

  In the case of this specific matter, since the learning operation is started almost simultaneously with the start of the vehicle travel, it is not necessary to wait for the execution condition of the learning operation to be satisfied by running the vehicle for a long distance. The learning value can be acquired later. Therefore, it is possible to complete the learning operation by driving the dealer operator. When the learning operation is executed by the driving of the operator of such a dealer, a driving operation different from that of the general user, that is, a driving operation suitable for early acquisition of the learning value can be expected. For example, in a vehicle equipped with a manual transmission, during the upshifting operation, the operator performs a driving operation (operation for slowly performing the shift change operation) that extends the period during which the accelerator opening is set to “0”. It is possible to acquire a large number of learning values in a short period of time (perform a single injection of a large number of single shots to acquire a large number of learning values) and complete the learning operation in a short period of time. be able to. Conventionally, since a learning operation is performed during driving by a general user, a driving operation suitable for early acquisition of a learning value cannot be expected, and one learning operation is performed by one upshifting operation. Was the limit.

  Further, after receiving the forced learning command signal from the transmitting means, the fuel injection amount learning operation may be forcibly executed in accordance with the learning operation start operation by the operator when the vehicle is stopped.

In this case, the accelerator depression operation by the work artisan may be the fuel injection from the fuel injection valve performed once to force the fuel injection amount learning operation each time it is performed once.

In this case, the accelerator depressing operation by the operator is repeated, and the fuel injection amount learning operation is performed by performing fuel injection from the fuel injection valve a plurality of times according to the operation. For this reason, the worker can continue the learning operation while confirming the progress of the learning operation. Further, by canceling the accelerator stepping operation before the completion of the learning operation, the learning operation can be stopped or interrupted as necessary.

  As described above, a more specific operation in the case where the fuel injection amount learning operation is performed by performing the fuel injection from the fuel injection valve once every time the accelerator is depressed by the operator is performed by the operator. Executes fuel injection from the fuel injection valve that is executed every time the accelerator is depressed, regardless of the operation period and amount of accelerator depression performed by the operator, with the fuel injection period and the fuel injection amount being uniform. I will let you.

  According to this, even if there is variation in the operation period and operation amount (depression amount) of the accelerator depressing operation by the operator, the fuel injection period and the fuel injection amount are uniform (a constant fuel injection period and a constant fuel injection amount). Thus, the learning operation can be executed. That is, fuel injection suitable for early acquisition of the learned value can be performed regardless of variations in the accelerator depressing operation by the operator.

  In addition, when the forced learning command signal is received from the transmission means, the fuel injection amount learning operation is forcibly executed by intermittently injecting fuel from the fuel injection valve automatically when the vehicle is stopped. In this case, it is possible to complete the learning operation automatically without requiring a special operation such as depressing the accelerator by the worker, and the burden on the worker can be greatly reduced.

  In the present invention, when the learning value disappears due to replacement of the ECU or the like, the mode is forcibly shifted to a mode in which the fuel injection amount learning operation is executed. Therefore, it is possible to complete the learning operation in a short period of time and perform fuel injection with the fuel injection amount according to the appropriate learning value at an early stage, and avoid problems caused by the fuel injection amount deviating from the appropriate value. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment demonstrates the case where this invention is applied to the common rail type | mold in-cylinder direct injection type multi-cylinder (for example, 4 cylinders) diesel engine mounted in the motor vehicle.

-Engine configuration description-
First, a schematic configuration of a diesel engine (hereinafter simply referred to as an engine) according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram of an engine 1 and its control system according to the present embodiment.

  An intake passage 4 is connected to a combustion chamber 3 formed between the cylinder 1a and the piston 1b in the engine 1 via an intake valve 4a as an intake system. An air cleaner 6 that filters intake air from the upstream side, an intake air amount sensor 8 that detects the intake air amount, an intake air temperature sensor 10 that detects the intake air temperature, and the combustion chamber 3 A throttle valve 14 is provided for adjusting the amount of intake air introduced into the interior.

  The throttle valve 14 is driven to open and close by a drive mechanism 16. The drive mechanism 16 includes a step motor 18 and a gear group that drives and connects the step motor 18 and the throttle valve 14. The step motor 18 is driven and controlled by an electronic control unit (hereinafter referred to as “ECU”) 20 for performing various controls of the engine 1. The drive mechanism 16 is provided with a fully open switch 22 that is turned on when the throttle valve 14 is in the fully open position.

  On the other hand, an exhaust passage 24 is connected to the combustion chamber 3 via an exhaust valve 24a as an exhaust system. An EGR (exhaust gas recirculation) passage 26 branches from the exhaust passage 24. The EGR passage 26 is connected to the downstream side of the throttle valve 14 in the intake passage 4. The EGR passage 26 is provided with an EGR valve 30 that is opened and closed by an actuator 28 controlled by the ECU 20. By adjusting the intake air amount by the throttle valve 14 and the EGR amount by the EGR valve 30, the ratio between the intake air amount introduced into the combustion chamber 3 and the EGR amount can be freely set. It is possible. As a result, the intake air amount and the EGR amount can be appropriately controlled over the entire operation region of the engine 1.

  The engine 1 is provided with a plurality of cylinders (in this embodiment, four cylinders, but only one cylinder is shown) # 1, # 2, # 3, and # 4. The injectors 32 are arranged for the combustion chambers 3 to # 4. Fuel injection from the injector 32 to the cylinders # 1 to # 4 of the engine 1 is controlled by turning on / off the electromagnetic valve 32a for injection control.

  The injector 32 is connected to a common rail 34 as a pressure accumulating container common to each cylinder, and the fuel in the common rail 34 burns from the injector 32 while the injection control electromagnetic valve 32a is open (injector opening period). It is injected into the chamber 3. A relatively high pressure corresponding to the fuel injection pressure is accumulated in the common rail 34. In order to realize this pressure accumulation, the common rail 34 is connected to the discharge port 36 a of the supply pump 36 via the supply pipe 35. A check valve 37 is provided in the middle of the supply pipe 35. Due to the presence of the check valve 37, the supply of fuel from the supply pump 36 to the common rail 34 is allowed, and the backflow of fuel from the common rail 34 to the supply pump 36 is restricted.

  The supply pump 36 is connected to a fuel tank 38 via a suction port 36b, and a filter 39 is provided in the middle thereof. The supply pump 36 sucks fuel from the fuel tank 38 through the filter 39. At the same time, the supply pump 36 receives the rotational driving force from the crankshaft, which is the output shaft of the engine 1, and reciprocates the plunger to increase the fuel pressure to the required pressure. Supply.

  Further, a pressure control valve 40 is provided in the vicinity of the discharge port 36 a of the supply pump 36. The pressure control valve 40 is for controlling the fuel pressure (that is, injection pressure) discharged from the discharge port 36a to the common rail 34. When the pressure control valve 40 is opened, excess fuel that is not discharged from the discharge port 36 a is returned from the return port 36 c provided in the supply pump 36 to the fuel tank 38 via the return pipe (return flow path) 41. It is supposed to be.

  As described above, the fuel supply system of the engine 1 is configured with the fuel tank 38, the supply pump 36, the common rail 34, and the injector 32 as main components.

  A glow plug 42 is disposed in the combustion chamber 3 of the engine 1. The glow plug 42 is a start assist device that is heated red when a current is passed through the glow relay 42a immediately before the engine 1 is started, and a part of the fuel spray is blown onto the glow plug 42a to promote ignition and combustion. .

  Note that the crankshaft of the engine 1 is provided with a rotor that rotates in synchronization with the rotation of the crankshaft, and a convex signal formed on the outer peripheral surface of the rotor is detected and a pulse signal corresponding to the rotational speed is generated. A rotation speed sensor 44 including an electromagnetic pickup for output is provided. The output of the rotation speed sensor 44 is taken into the ECU 20 as a signal that contributes to the calculation of the rotation speed of the engine 1.

  The ECU (Electronic Control Unit) 20 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a backup RAM, a timer, a counter, and the like, and an A / D (Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog / Analog An external input circuit including a digital converter and an external output circuit are connected by a bidirectional bus.

  The ECU 20 configured as described above inputs detection signals of various sensors via an external input circuit, and based on these signals, various controls relating to the operating state of the engine 1, such as basic control for fuel injection of the engine 1 and the like. Execute. Specifically, the ECU 20 includes an accelerator opening amount detected by the accelerator opening sensor 46, including the intake air amount information detected by the intake air amount sensor 8 and the intake air temperature information detected by the intake air temperature sensor 10. Degree information (accelerator pedal depression amount information), IG (ignition) switch 48 on / off information, starter switch 50 on / off information, and cooling water temperature detected by a cooling water temperature sensor 52 provided in the water jacket 2a. Information, shift position information detected by a shift position sensor 54 provided in the transmission and vehicle speed information detected by a signal from the vehicle speed sensor 56, detected by a fuel temperature sensor 58 provided in a return pipe 41 extending from the injector 32. Fuel temperature information, Information such as fuel temperature information detected by the fuel temperature sensor 59 provided in the vicinity of the engine port 36c and fuel pressure (injection pressure PC) information detected by the fuel pressure sensor 60 provided on the common rail 34 are also taken in, Various controls relating to the operating state of the engine 1 are executed based on these information.

-Fuel injection amount learning control-
Next, a plurality of embodiments of fuel injection amount learning control, which is a control operation that is a feature of the present embodiment, will be described.

  In the fuel injection amount learning control, as described above, a very small amount of fuel is directed to a specific cylinder (a cylinder in which the piston 1b is near the compression top dead center) at the time of non-injection when the command injection amount to the injector 32 is zero or less. The amount of change in the engine operating state associated with this single injection is recognized. Then, the change amount data of the engine operation state when the single injection of a predetermined amount is executed accurately is compared with the change amount of the engine operation state when the single injection is actually performed, and according to the deviation amount The learning value is acquired and the learning value of the injection amount setting map stored in the ECU 20 is corrected.

  However, if the ECU 20 is replaced by a car dealer or the like due to a failure of the ECU 20 or the like, the learning value on the injection amount setting map may be lost and an appropriate injection amount may not be obtained. .

  Each of the embodiments described below enables the newly installed ECU 20 to store an appropriate learning value in a short period of time by completing the learning operation early after replacement of the ECU 20 in such a situation. It is.

  Note that in a situation where the ECU 20 is not replaced, the learning operation is performed at the same timing as in the past. In other words, when the vehicle has traveled a predetermined distance from the completion of the previous learning operation, the mode is shifted to the learning mode, and in this mode, the single injection is performed at the time of non-injection when the command injection amount to the injector 32 becomes zero or less The learning value is acquired.

(First embodiment)
In this embodiment, after the ECU (engine ECU) 20 breaks down and the ECU 20 is replaced by the card dealer, the learning operation is executed by running the vehicle by the driving of the operator of the card dealer to perform fuel injection. The learning value of quantity is acquired.

  Specifically, after the replacement of the ECU 20, a tool for transmitting a command (forced learning command signal) for forcibly executing a learning operation to the newly mounted ECU 20 (transmitting means in the present invention: for example, personal A computer) and forcibly shift to the fuel injection amount learning mode (forced execution operation of the fuel injection amount learning operation by the learning operation forcible execution means). Then, the learning value of the fuel injection amount is appropriately obtained while the operator of the card dealer runs the vehicle over a relatively short distance (for example, about 2 km).

  FIG. 2 is an example of changes in the degree of deterioration of the injector, the injection amount accuracy of the injector 32 (the injection amount accuracy is worse in the upper side in the figure), and the learning value in this case, and the ECU 20 at timing Tc in the figure. Shows the case where is replaced.

  As shown in FIG. 2, before the ECU 20 is replaced, the deterioration of the injector 32 progresses as the vehicle travel distance increases (see the waveform representing the degree of deterioration of the injector 32), but learning is performed at a predetermined interval. The operation is executed (see the learning timings Ta and Tb on the waveform representing the injection amount accuracy of the injector 32), and the learning value is updated (see the waveform representing the learning value), whereby the injection amount accuracy of the injector 32 is obtained. Is obtained appropriately. The execution interval of the learning operation in this case is after the vehicle has traveled a predetermined travel distance from the previous execution of the learning operation, and when there is no injection when the command injection amount to the injector 32 becomes zero or less (for example, manual The learning operation is performed during a shift-up operation of a vehicle equipped with a transmission. By performing the learning operation at such timing, the injection amount accuracy of the injector 32 does not exceed the guaranteed injection amount accuracy line that is the allowable limit value for the deterioration of the injection amount accuracy of the injector 32.

  Then, when the ECU 20 is replaced at the timing Tc in the figure and the learned value no longer exists on the pilot injection amount setting map, the tool is connected to the newly mounted ECU 20 to forcibly learn the operation. A command to be executed is transmitted from this tool to the ECU 20. As a result, the ECU 20 forcibly shifts to the fuel injection amount learning mode.

  In this way, the learning operation is carried out while the card dealer's operator travels the vehicle for a relatively short distance (for example, about 2 km) in the state where the fuel injection amount learning mode has been entered.

  In this learning operation, the fuel injection amount learning operation is executed substantially simultaneously with the start of the vehicle travel, so there is no need to wait for the learning operation execution condition to be satisfied by traveling the vehicle for a long distance. Accordingly, the learning operation can be completed by traveling the vehicle over a relatively short distance by the dealer operator.

  Further, when the learning operation is executed by the driving of such a dealer operator, it is possible to expect a driving operation different from that of the general user, that is, a driving operation suitable for early acquisition of the learning value. For example, in a vehicle equipped with a manual transmission, during a shift change (for example, a shift up) operation, a driving operation (an operation for performing a shift change operation slowly) that increases the period during which the accelerator opening is “0” is performed. As a result, a large number (for example, 10) of learning values can be acquired by one shift change operation, and the learning operation can be completed in a short period of time. For example, in the work manual, it is described that when the learning operation is performed, a driving operation is performed so as to lengthen the period during which the accelerator opening is “0”, and the operator can easily perform the driving operation according to the operation. Can be realized.

  FIG. 3 shows that when the accelerator opening is set to “0” during a shift-up operation or the like (the accelerator opening is returned to “0” at the timing Td in the figure), 10 times while the engine speed is decreasing. It is a waveform which shows the change of the engine speed at the time of implementing single injection of this. As described above, it is possible to perform 10 single injections by performing an operation that ensures a long period (period Te in the figure) in which the accelerator opening is “0”. Ten learning values can be acquired continuously during the upshifting operation.

Specifically, when it is determined that the accelerator opening is “0” based on the accelerator opening signal detected by the accelerator opening sensor 46, the signal from the rotation speed sensor 44 is The engine speed is recognized, and the number of single injections that can be executed while the engine speed decreases from the engine speed to the idle speed is calculated. Then, the learning value is continuously acquired by intermittently performing the single injection of the number of times obtained by the above calculation while the engine speed is decreasing due to the accelerator opening being “0”. I am doing so. FIG. 3 shows that the engine speed N1 before the start of the upshift operation is 4000 rpm, the engine speed N2 (idle speed) during the upshift operation (when the accelerator opening is “0”) is 800 rpm, As a single injection, 2 mm ³ fuel injection is performed, and the case where the engine speed is increased by 2-3 rpm (N3 in the figure) by each single injection is shown. In this case, 10 single injections are performed. Is possible. In addition, if the difference between the engine speed N1 before the start of the upshifting operation and the engine speed N2 during the upshifting operation is made larger, it is possible to carry out 11 or more single injections. It is also possible to continuously acquire 11 or more learning values during the upshifting operation. For example, in a vehicle equipped with a manual transmission, at the time of shifting up, the engine disengagement operation is preceded by the release operation of the accelerator pedal, so that the engine speed is temporarily increased and the engine at the time when the accelerator pedal is released. One example is to ensure a high rotational speed.

  As described above, since a large number of learning values can be acquired continuously during one shift change operation, for example, when learning operation is completed by acquiring 160 learning values, For example, 10 learning values can be acquired by the shift change operation. As a result, the learning operation can be completed only by performing the shift change operation 16 times. Conventionally, since a learning operation is performed while a general user is driving, a driving operation suitable for early acquisition of a learning value cannot be expected, and one learning operation is performed by one shift change operation. Was the limit. For this reason, 160 shift changes are required to obtain 160 learning values, and a long period of time is required to complete the learning operation.

  As described above, in this embodiment, the learning operation can be completed by a relatively short-distance vehicle traveling by a dealer operator. Therefore, the latest operation can be performed at the same time as timing Tc in FIG. 2 or with a slight delay. A learned value is acquired, and the injection amount accuracy of the injector 32 can be obtained with this learned value. That is, even when the ECU 20 is replaced, the learning operation can be performed in the same manner as when the ECU 20 is not replaced or at an earlier timing than when the ECU 20 is not replaced, and an appropriate fuel injection amount can be obtained. .

  The two-dot chain line in FIG. 2 is a conventional example, and since the injector is replaced, the learning value is set to “0” until the next learning operation execution condition is satisfied, and the fuel injection accuracy deteriorates. The waveform is shown when

  As described above, in this embodiment, the learning operation can be completed at an early stage by driving the operator of the dealer. Therefore, when the vehicle is delivered to the user, an appropriate fuel injection amount can be obtained. As a result, problems (deterioration of drivability, generation of white smoke in exhaust, etc.) due to the fuel injection amount deviating from an appropriate value can be avoided.

(Second Embodiment)
In the present embodiment, after the ECU (engine ECU) 20 breaks down and the ECU 20 is replaced by a card dealer, the learning operation is executed while the vehicle is stopped to acquire the learning value of the fuel injection amount. It is. That is, the learning operation is completed by so-called racing in which the fuel injection operation is intermittently performed to increase the engine speed intermittently. Here, differences from the above-described first embodiment will be mainly described.

  Specifically, after the ECU 20 is replaced, a tool for transmitting a command for forcibly executing the learning operation is connected to the newly installed ECU 20 to forcibly shift to the fuel injection amount learning mode. Then, with the engine 1 in an idling state and the transmission set to neutral, the operator of the card dealer performs the accelerator pedal depression operation (learning operation start operation in the present invention) only once with the vehicle stopped. Then, the learning operation is started. That is, the learning value of the fuel injection amount is acquired by performing racing a plurality of times starting from a single depression of the accelerator pedal.

  FIG. 4 shows an example of changes in the engine speed and the injection amount of the injector 32 in this case.

  As shown in FIG. 4, when the operator performs the accelerator pedal stepping operation once, 14 times of racing are executed, and in each racing, the case described with reference to FIG. 3 in the first embodiment described above Similarly, 10 single injections are performed in the middle of the decrease in the engine speed, and 10 learning values are continuously acquired. In this case, the fuel injection period and the fuel injection amount in each racing are the same so that the learning operation can be completed early.

  Thereby, 140 learning values can be acquired, and the learning operation can be completed almost simultaneously with the end of 10 times of racing (the learning operation is completed by acquiring 140 learning values. If any).

  In the present embodiment, the operation until the learning operation is completed can be automated, and the burden on the operator can be reduced. In addition, the time required for completing the learning operation can be made constant.

(Third embodiment)
In the present embodiment, as in the case of the second embodiment described above, the fuel injection amount is obtained by executing the learning operation when the vehicle is stopped after the ECU 20 has been replaced by the card dealer due to the failure of the ECU 20 or the like. The learning value is acquired. That is, the learning operation is completed by so-called racing in which the engine speed is intermittently increased. Here, differences from the above-described second embodiment will be mainly described.

  Specifically, after the ECU 20 is replaced, a tool for transmitting a command for forcibly executing the learning operation is connected to the newly installed ECU 20 to forcibly shift to the fuel injection amount learning mode. Then, every time the operator of the card dealer performs the depression operation of the accelerator pedal while the vehicle is stopped, the racing is performed once to acquire the learning value of the fuel injection amount. That is, the operator intermittently depresses the accelerator pedal a plurality of times and performs racing each time, thereby acquiring a large number of learning values.

  A specific procedure of this operation will be described with reference to the flowchart of FIG. First, in step ST1, it is determined whether or not a command signal (command signal for forcibly executing a learning operation) is input from the tool. When this command signal is input and a Yes determination is made in step ST1, the process proceeds to step ST2 and shifts to a fuel injection amount learning mode by racing.

  After shifting to the fuel injection amount learning mode in this way, in step ST3, the operator waits for an accelerator pedal depression operation. When the accelerator pedal is depressed, a determination of Yes is made in step ST3 and the process proceeds to step ST4. In step ST4, the racing operation is performed once. By performing this racing operation, for example, 10 learning values are acquired in the same manner as in the above embodiment.

  After performing this racing operation, the process proceeds to step ST5, and the completion of the learning operation is determined. For example, the completion of the learning operation is determined based on whether or not 140 learning values have been acquired. If the acquired learning value is still small and No is determined in step ST5, the process returns to step ST3. That is, it waits for the next depressing operation of the accelerator pedal by the operator. When the accelerator pedal is depressed, the racing operation is performed once in the same manner as described above, and, for example, 10 learning values are acquired. The fuel injection period and the fuel injection amount in each racing in this case are also the same as in the case of the second embodiment.

  If such an operation is repeated and a predetermined number (for example, 140) of learning values are acquired, a Yes determination is made in step ST5, the racing learning mode is canceled, the normal mode is restored, and the learning operation is terminated. .

  FIG. 6 shows an example of changes in the learning progress, the engine speed, the injection amount of the injector 32, and the accelerator opening in this case.

  As shown in FIG. 6, in this embodiment, even if there is variation in the operation period and the operation amount (depression amount) of the accelerator depressing operation by the operator, the learning operation is performed with the fuel injection period and the fuel injection amount being uniform. I am trying to execute it. That is, fuel injection suitable for early acquisition of the learned value can be performed regardless of variations in the accelerator depressing operation by the operator.

  FIG. 7 shows an example in which the fuel injection is performed in the fuel injection period and the fuel injection amount according to the operation period and the operation amount (depression amount) of the accelerator depressing operation by the operator, and the learning operation is executed. That is, when the operation period of the accelerator depressing operation by the operator is short, the fuel injection period is also short, and when the operation amount (depressing amount) of the accelerator depressing operation is small, the fuel injection amount is also small. In this case, the learning progress may be delayed. In the present embodiment, as described above, the learning operation is executed with the fuel injection period and the fuel injection amount uniformly regardless of the variation in the accelerator depressing operation by the operator, so the learning progress is fast and the learning operation is performed in a short period of time. Can be completed.

  As described above, in this embodiment, the fuel injection amount learning operation is performed by performing the fuel injection from the injector 32 a plurality of times by repeating the accelerator stepping operation by the worker, so that the worker learns This learning operation can be continued while recognizing the progress of the operation. Further, by canceling the accelerator stepping operation before the completion of the learning operation, the learning operation can be stopped or interrupted as necessary.

(Fourth embodiment)
In the present embodiment, as in the case of the second embodiment described above, the fuel injection amount is obtained by executing the learning operation when the vehicle is stopped after the ECU 20 has been replaced by the card dealer due to the failure of the ECU 20 or the like. The learning value is acquired. That is, the learning operation is completed by so-called racing in which the engine speed is intermittently increased. Here, differences from the above-described second embodiment will be mainly described.

  Specifically, after the ECU 20 is replaced, a tool for transmitting a command for forcibly executing the learning operation is connected to the newly installed ECU 20 to forcibly shift to the fuel injection amount learning mode. When a command signal is received from this tool, the learning operation starts almost simultaneously. That is, the learning value of the fuel injection amount is acquired by automatically performing racing a plurality of times.

  A specific procedure of this operation will be described with reference to the flowchart of FIG. First, in step ST11, it is determined whether or not a command signal (command signal for forcibly executing a learning operation) is input from the tool. When this command signal is input and a Yes determination is made in step ST11, the process proceeds to step ST12 and shifts to a fuel injection amount learning mode (racing learning mode).

  In this way, simultaneously with the shift to the fuel injection amount learning mode, the racing operation is automatically performed a plurality of times to start the fuel injection amount learning operation, and the learning value is acquired. After performing this racing operation, the process proceeds to step ST13, and the completion of the learning operation is determined. For example, the completion of the learning operation is determined based on whether or not 140 learning values have been acquired. If the acquired learning value is still small and No is determined in step ST13, the learning operation is continued.

  When a predetermined number of learning values are acquired, a Yes determination is made in step ST13, the fuel injection amount learning mode is canceled, the normal mode is restored, and the learning operation is terminated.

  Also in this case, as shown in FIG. 4, when a command signal is received from the tool, 14 times of racing are automatically executed, and each racing is described with reference to FIG. 3 in the first embodiment described above. As in the case where the engine speed is decreased, 10 single injections are performed while the engine speed is decreasing, and 10 learning values are continuously acquired.

  Thereby, 140 learning values can be acquired, and the learning operation can be completed almost simultaneously with the end of 10 times of racing.

  As described above, in this embodiment, the operation until the learning operation is completed can be fully automated, and the burden on the operator can be reduced. In addition, the time required for completing the learning operation can be made constant.

-Other embodiments-
Each embodiment described above explained the case where the present invention was applied to a common rail in-cylinder direct injection multi-cylinder (four-cylinder) diesel engine. The present invention is not limited to this, and can be applied to a diesel engine having any other number of cylinders such as a six-cylinder diesel engine. Further, the present invention is not limited to a diesel engine but can be applied to other internal combustion engines such as a gasoline engine. Furthermore, the engine to which the present invention is applicable is not limited to an automobile engine.

  Moreover, although each said embodiment demonstrated the case where 10 single injections were implemented in the middle of the fall of an engine speed at the time of execution of learning operation | movement, it is not limited to this number of times.

  In each of the above embodiments, the case where the present invention is applied to a vehicle equipped with a manual transmission has been described. The present invention is not limited to this, and can also be applied to a vehicle equipped with an automatic transmission. For example, when the learning operation is performed while the vehicle is traveling as in the first embodiment, the learning operation is completed early by performing an operation that lengthens the period during which the accelerator opening is set to “0”. Can be made. For example, this is a driving operation that lengthens the coasting period. On the other hand, when the learning operation is executed while the vehicle is stopped as in the second to fourth embodiments, the shift lever range position is set to “P (parking)” or “N (neutral)”. Will be executed in the state.

  Furthermore, in the second embodiment, when the operator performs the accelerator pedal stepping operation once, racing is executed a plurality of times (14 times). That is, the accelerator pedal is used as a switch for executing a plurality of times of racing. For this reason, not only the depression operation of the accelerator pedal but also any operation can be used as a switch for executing a plurality of times of racing. For example, multiple races are executed in conjunction with the depression of the clutch pedal, or multiple races are executed when both the depression of the clutch pedal and the depression of the brake pedal are performed. Or you can. Further, a plurality of races may be executed in conjunction with operating switches provided on the tool.

It is a schematic block diagram of the engine which concerns on embodiment, and its control system. It is a figure which shows an example of the deterioration degree of the injector in 1st Embodiment, the injection quantity precision of an injector, and the change of a learning value. It is a wave form diagram which shows the change of an engine speed when implementing 10 single injections in the middle of the fall of an engine speed and acquiring ten learning values. It is a figure which shows an example of the change of the engine speed in 2nd Embodiment, and the injection quantity of an injector. It is a flowchart figure which shows the control procedure of learning operation | movement in 3rd Embodiment. It is a figure which shows an example of the change of learning progress in 3rd Embodiment, an engine speed, the injection quantity of an injector, and an accelerator opening. It is a figure which shows an example of the change of the learning progress in a comparative example, an engine speed, the injection quantity of an injector, and an accelerator opening. It is a flowchart figure which shows the control procedure of learning operation | movement in 4th Embodiment. It is a figure which respectively shows the deterioration degree of an injector, the injection amount precision of an injector, and the change of a learning value in the case of acquiring a learning value without exchanging ECU. It is a timing chart figure which shows an example of the execution timing of the conventional learning operation | movement. It is a figure which respectively shows the deterioration degree of an injector, the injection amount precision of an injector, and the change of a learning value when ECU is replaced | exchanged.

Explanation of symbols

1 engine (internal combustion engine)
20 ECU
32 Injector (fuel injection valve)

Claims (7)

When the execution condition of the fuel injection amount learning operation is satisfied, fuel is injected from a fuel injection valve into a specific cylinder of the vehicle internal combustion engine, and the target fuel injection amount is determined based on the change in the operating state of the internal combustion engine accompanying the fuel injection. In a fuel injection amount learning control device for executing a fuel injection amount learning operation for acquiring a learning value based on a deviation of an actual fuel injection amount with respect to
When the learning value disappears, the learning operation forcing execution means for forcibly executing the fuel injection amount learning operation for acquiring the learning value even when the execution condition is not satisfied is provided,
The learning operation compulsory execution means is configured such that when the learning value disappears, the accelerator opening associated with the driving operation for ensuring a long state of setting the accelerator opening to “0” becomes “0” or the fuel injection valve The fuel injection amount learning operation is forcibly executed when the command injection amount to 0 is less than or equal to zero, and when the fuel injection amount learning operation is forcibly executed, the accelerator opening is The engine speed is recognized at the time when it becomes “0” or when the command injection amount to the fuel injection valve becomes less than zero, and is used for learning in the period from when the engine speed decreases to the idle speed. A fuel injection amount configured to calculate a feasible number of single injections and to acquire a plurality of learning values by intermittently executing the calculated number of single injections during the period Learning control device. In the fuel injection amount learning control device according to claim 1,
The learning operation forcibly executing means is configured to forcibly execute the fuel injection amount learning operation by shifting to the learning mode by receiving a forced learning command signal from a transmitting means for transmitting a learning operation forcible execution command. A fuel injection amount learning control device. In the fuel injection amount learning control device according to claim 2,
The learning operation compulsory execution means forcibly executes the fuel injection amount learning operation when the fuel injection valve is not injecting during traveling of the vehicle after receiving the compulsory learning command signal from the transmitting means. A fuel injection amount learning control device. In the fuel injection amount learning control device according to claim 2,
The learning operation forcible execution means forcibly executes the fuel injection amount learning operation in accordance with the learning operation start operation by the operator when the vehicle is stopped after receiving the forced learning command signal from the transmission means. A fuel injection amount learning control device. In the fuel injection amount learning control device according to claim 4,
The learning operation start operation by the operator is an accelerator depression operation,
The learning operation forcible execution means is configured to forcibly execute the fuel injection amount learning operation by performing fuel injection from the fuel injection valve once every time the accelerator is depressed once by the operator. A fuel injection amount learning control device. In the fuel injection amount learning control device according to claim 5,
The learning operation compulsory execution means performs fuel injection from the fuel injection valve that is executed each time the accelerator is depressed by the operator regardless of the operation period and the amount of depression of the accelerator depression by the operator. A fuel injection amount learning control device characterized in that the injection period and the fuel injection amount are uniformly executed. In the fuel injection amount learning control device according to claim 2,
The learning operation forcibly executing means forcibly performs the fuel injection amount learning operation by intermittently injecting fuel from the fuel injection valve automatically when the vehicle is stopped when receiving the forced learning command signal from the transmitting means. A fuel injection amount learning control device characterized in that the fuel injection amount learning control device is executed.

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