JP2007278302A - Diesel engine control method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the interruption of shift shock preventing effects on a diesel engine in which a fuel injection amount is reduced for black smoke prevention and shift shock prevention. <P>SOLUTION: During the shift operation of an automatic transmission (YES in S104), when the setting (Fig.3: S204) of a black smoke countermeasure calculated value A is established (YES in S104a), a value for min(A, B) is corrected to be greater to correct a degree of reducing a fuel injection amount to be lower for substantial black smoke prevention. This construction avoids the interruption of shift shock prevention by a shift ECU even when black smoke countermeasure control processing (Fig.3) and shift torque-down control processing (Fig.4) are executed. During the shift operation, a reduction of the amount of fuel for black smoke countermeasures means that a degree of the reduction is only lower and it does not mean that a reduction of the amount of fuel is stopped, and so there are almost no problems on the black smoke prevention. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a diesel engine control that executes a fuel injection amount reduction process for preventing black smoke based on an engine speed and executes a fuel injection amount reduction process for preventing a shift shock during a shift of an automatic transmission. .

  A process in which the shift control system in a diesel engine temporarily reduces the engine output torque by causing the engine control system to reduce the fuel injection amount during shifts, thereby preventing shift shocks caused by the automatic transmission. Is known (Patent Document 1).

On the other hand, when the engine speed increases rapidly, black smoke may be generated due to combustion instability of the diesel engine. For this reason, on the engine control system side, if the engine speed change shows an increase higher than the judgment value provided for black smoke countermeasures, the fuel injection amount is temporarily reduced to generate black smoke. Is suppressed.
Japanese Patent Laid-Open No. 5-71385

  However, when the above-described shift control system and the engine control system are combined, there are the following problems. That is, when the speed change control system is executing speed change processing, particularly when performing a downshift at power-on, the engine speed rapidly increases, and the engine control system side prevents the above-described black smoke. This may cause a fuel injection amount reduction process.

  As described above, on the shift control system side, the output torque of the diesel engine is reduced to prevent shift shock, and the combination of the rotating members in the automatic transmission is switched at an appropriate timing corresponding to the reduction of the engine output torque. It is carried out. By executing such a series of processes, torque fluctuations in the output shaft of the automatic transmission accompanying a shift are appropriately prevented.

  However, unlike the shift control as described above, when the fuel injection amount is reduced from the viewpoint of preventing black smoke, the engine output torque is unexpectedly decreased on the shift control system side. For this reason, the rotation state of each rotary member in the automatic transmission becomes a state that cannot be predicted by the shift control system, and the switching of the combination of the rotary members in the automatic transmission described above cannot be performed at an appropriate timing. For this reason, there is a risk that torque fluctuations on the output shaft of the automatic transmission will not be properly prevented.

  According to the present invention, in a diesel engine having a configuration in which a fuel injection amount reduction process for preventing black smoke and a fuel injection amount reduction process for preventing a shift shock of an automatic transmission are executed, the shift shock prevention effect is not hindered. The purpose is to make it.

In the following, means for achieving the above object and its effects are described.
The diesel engine control method according to claim 1 executes a fuel injection amount reduction process for preventing black smoke based on the engine speed, and reduces a fuel injection amount for preventing a shift shock during a shift of the automatic transmission. In the diesel engine for performing the processing, each of the fuel injection amount reduction processes is performed by reducing the upper limit value of the fuel injection amount, and the smaller upper limit value among the upper limit values obtained by the two fuel injection amount reduction processes. And limiting the fuel injection amount based on the selected upper limit value, and during the shift of the automatic transmission and when the fuel injection amount reduction processing for preventing the black smoke is being performed, The selected upper limit value is increased and corrected.

  As described above, when the automatic transmission is being shifted and the fuel injection amount reduction process for preventing black smoke is being executed, the selected upper limit value is increased and corrected to substantially prevent black smoke. Therefore, the fuel injection amount reduction amount by the fuel injection amount reduction process for the reduction can be corrected. As a result, even if a fuel injection amount reduction process for preventing black smoke is executed during gear shifting, a reduction in engine output torque that is unexpected for the gear shifting control system is suppressed. For this reason, even when the combination of the rotating members in the automatic transmission is switched at the timing corresponding to the fuel injection amount reduction process for preventing the shift shock, the rotation state of the rotating members in the automatic transmission is not expected. Since there is no significant difference from the above state, the shift shock can be reliably prevented. As described above, in the diesel engine, even if the fuel injection amount reduction process for preventing black smoke and the fuel injection amount reduction process for preventing the shift shock of the automatic transmission are executed, the shift shock prevention effect is inhibited. It will not be done.

  It should be noted that the reduction correction of the fuel injection amount reduction amount for preventing black smoke is temporary because it is made during the shift, and further, the fuel injection amount reduction processing for preventing black smoke is completely prohibited. Do not mean. For this reason, although the degree is lower than usual, there is a case where the fuel injection amount is reduced to prevent black smoke, so that the influence on black smoke prevention is very small. Moreover, since the fuel injection amount reduction processing for preventing the shift shock is performed during this shift, the black smoke tends to be suppressed even if the fuel injection amount reduction amount is corrected to reduce the black smoke. There are almost no problems with black smoke prevention.

  The diesel engine control method according to claim 2 executes a fuel injection amount reduction process for preventing black smoke based on the engine speed, and reduces a fuel injection amount for preventing a shift shock during a shift of the automatic transmission. In the diesel engine for performing the processing, each of the fuel injection amount reduction processes is performed by reducing the upper limit value of the fuel injection amount, and the smaller upper limit value among the upper limit values obtained by the two fuel injection amount reduction processes. The fuel injection amount is limited based on the selected upper limit value, and the fuel injection amount reduction process for preventing the shift shock and the fuel injection amount reduction process for preventing the black smoke are being executed. In some cases, the selected upper limit value is increased and corrected.

  As described above, when both the fuel injection amount reduction process for preventing shift shock and the fuel injection amount reduction process for preventing black smoke are being executed, the selected upper limit value is increased and corrected. In particular, the fuel injection amount reduction amount by the fuel injection amount reduction processing for preventing black smoke can be reduced and corrected. As a result, even if the fuel injection amount reduction process for preventing black smoke is executed during the execution of the fuel injection amount reduction process for preventing the shift shock, the engine output torque is not unexpectedly reduced for the shift control system side. It won't be big. Therefore, even when the combination of the rotating members in the automatic transmission is switched at a timing corresponding to the fuel injection amount reduction process for preventing the shift shock, the rotation state of the rotating members in the automatic transmission is expected. Since there is no significant difference from the above state, a shift shock can be prevented. As described above, in the diesel engine, even if the fuel injection amount reduction process for preventing black smoke and the fuel injection amount reduction process for preventing the shift shock of the automatic transmission are executed, the shift shock prevention effect is inhibited. It will not be done.

  The fuel injection amount reduction correction for preventing black smoke is temporary during the execution of the fuel injection amount reduction processing for preventing shift shock, and is also used for preventing black smoke. The fuel injection amount reduction process is not completely prohibited. For this reason, although the degree is lower than usual, there is a case where the fuel injection amount is reduced to prevent black smoke, so that the influence on black smoke prevention is very small. In addition, since the fuel injection amount reduction processing for preventing the shift shock is performed at this time, the black smoke tends to be suppressed even if the fuel injection amount reduction amount is corrected to reduce the black smoke. Therefore, there is almost no problem in preventing black smoke.

  According to a third aspect of the present invention, there is provided a diesel engine control device comprising: an engine speed detecting means for detecting an engine speed of a diesel engine; and an engine speed change detected by the engine speed detecting means being larger than a black smoke countermeasure determination value. When the amount of change is indicated, the black smoke prevention means for reducing the fuel injection amount to prevent black smoke by reducing the upper limit value of the fuel injection amount, the shift control means for controlling the shift of the automatic transmission, Shift shock prevention means for reducing the fuel injection amount to prevent shift shock by reducing the upper limit value of the fuel injection amount during shift of the automatic transmission by the shift control means, the black smoke prevention means, and the shift shock Limiting means for selecting the smaller upper limit value among the upper limit values set by the prevention means and limiting the fuel injection amount based on the selected upper limit value; Black smoke-preventing fuel that corrects the upper limit value selected by the limiting means when the shift control means is shifting the automatic transmission and the fuel injection amount is being reduced by the black smoke preventing means. An injection reduction amount reducing means is provided.

  Thus, when the automatic transmission is shifting and the fuel injection amount reduction by the black smoke prevention means is being executed, the black smoke prevention fuel injection reduction amount reduction means sets the upper limit value selected by the restriction means. By performing the increase correction, it is possible to substantially reduce and correct the fuel injection amount reduction amount for preventing black smoke. For this reason, during the speed change, the engine output torque is not reduced unexpectedly for the speed change control means. Therefore, when the shift control unit executes switching of the combination of the rotating members in the automatic transmission at the timing corresponding to the fuel injection amount reduction process for preventing the shift shock performed by the shift shock preventing unit, the automatic shift is performed. The rotational state of each rotating member inside the machine is not significantly different from the expected state. For this reason, a shift shock can be reliably prevented. In this way, even if the black smoke prevention means and the shift shock prevention means are provided in the diesel engine, the shift shock prevention effect by the shift shock prevention means is not hindered.

  The fuel injection amount reduction correction performed by the black smoke prevention fuel injection reduction amount reduction means is temporary because it is made during a shift, and the fuel injection amount reduction by the black smoke prevention means is completely prohibited. I'm not doing it. For this reason, since the amount of fuel injection for black smoke prevention may be reduced by the black smoke prevention means to a lesser extent than usual, the influence on black smoke prevention is very small. In addition, since the fuel injection amount is reduced by the shift shock prevention means during this shift, black smoke tends to be suppressed even if the fuel injection amount reduction amount is corrected by the black smoke prevention means. There is almost no problem with black smoke prevention.

  According to a fourth aspect of the present invention, there is provided a diesel engine control device comprising: an engine speed detecting means for detecting an engine speed of a diesel engine; and an engine speed change detected by the engine speed detecting means being larger than a black smoke countermeasure determination value. When the amount of change is indicated, the black smoke prevention means for reducing the fuel injection amount to prevent black smoke by reducing the upper limit value of the fuel injection amount, the shift control means for controlling the shift of the automatic transmission, Shift shock prevention means for reducing the fuel injection amount to prevent shift shock by reducing the upper limit value of the fuel injection amount during shift of the automatic transmission by the shift control means, the black smoke prevention means, and the shift shock Limiting means for selecting the smaller upper limit value among the upper limit values set by the prevention means and limiting the fuel injection amount based on the selected upper limit value; When both the shift shock prevention means and the black smoke prevention means are executing the fuel injection amount reduction, the shift shock prevention means and the black smoke prevention fuel injection reduction amount reduction means for increasing and correcting the upper limit value selected by the restriction means are provided. Features.

  Thus, when both the shift shock prevention means and the black smoke prevention means are executing the fuel injection amount reduction, the black smoke prevention fuel injection reduction amount reduction means increases and corrects the upper limit value selected by the restriction means. Thus, it is possible to substantially reduce and correct the fuel injection amount reduction amount for preventing black smoke. As a result, even if the fuel injection amount is reduced by the black smoke prevention means while the fuel injection amount is being reduced by the shift shock prevention means, an unexpected decrease in engine output torque for the shift control means is not significant. For this reason, a shift shock can be prevented. In this way, even if the black smoke prevention means and the shift shock prevention means are provided in the diesel engine, the shift shock prevention effect by the shift shock prevention means is not hindered.

  The reduction correction of the fuel injection amount reduction amount in the black smoke prevention means is temporary because it is when the fuel injection amount by the shift shock prevention means is reduced, and the fuel injection amount in the black smoke prevention means. Reduction is not completely prohibited. For this reason, although the degree is lower than usual, there is a case where the fuel injection amount is reduced to prevent black smoke, so that the influence on black smoke prevention is very small. Moreover, since the fuel injection amount is reduced by the shift shock prevention means at this time, the black smoke tends to be suppressed even if the black smoke prevention means corrects the fuel injection amount reduction amount. There are few problems with prevention.

[Embodiment 1]
FIG. 1 is a block diagram showing an accumulator diesel engine 2, an automatic transmission 4, and their respective ECUs (electronic control units) 6 and 8 as the first embodiment. The accumulator diesel engine 2 is mounted on a vehicle as an automobile engine.

  The diesel engine 2 is provided with a plurality of cylinders, for example, four cylinders, and a fuel injection valve is provided for each combustion chamber. Fuel that has been boosted to the fuel injection pressure from the common rail is supplied to the fuel injection valve, and the fuel injection valve is opened by a command from the engine ECU 6 during a valve opening period corresponding to the fuel injection amount required for the diesel engine 2. As a result, fuel is injected into each cylinder.

  The diesel engine 2 is provided with various sensors 10 such as an accelerator opening sensor, an engine speed sensor, a cylinder discrimination sensor, a cooling water temperature sensor, an intake air temperature sensor, a fuel pressure sensor, and a vehicle speed sensor. Based on the output, the engine ECU 6 detects the operating state of the diesel engine 2 and the traveling state of the vehicle. The engine ECU 6 also communicates with the speed change ECU 8 to exchange commands and data with each other. The engine ECU 6 controls the combustion state of the diesel engine 2 by fuel injection amount control or the like based on these commands and data.

  The automatic transmission 4 is a torque converter type automatic transmission, and is a transmission that changes gears by controlling the operation of various internal gears such as planetary gears, clutches, and brakes. The various sensors 10 include a shift position sensor and a turbine rotation speed sensor provided in the automatic transmission 4. The shift ECU 8 determines the driver's request, the internal state of the automatic transmission 4 and the vehicle running state based on data such as the accelerator opening ACCP, the throttle opening, the engine speed NE, the shift position, the turbine speed NT, and the vehicle speed. The shift control for the automatic transmission 4 is executed upon detection. Further, among the data detected by the engine ECU 6, the coolant temperature, the brake state, and the like are also read. As described above, the speed change ECU 8 also communicates with the engine ECU 6 to exchange commands and data with each other. The shift ECU 8 performs shift control of the automatic transmission 4 by switching the electromagnetic valve of the hydraulic control circuit 4a based on these commands and data. For example, the hydraulic control circuit is configured to determine the gear stage of the automatic transmission 4 based on the vehicle speed V and the fuel injection amount (or accelerator opening) from a pre-stored shift diagram and to establish the determined gear stage. The solenoid valve 4a is switched.

The engine ECU 6 and the speed change ECU 8 are mainly composed of a microcomputer including the following elements.
Central processing controller (CPU).
A read-only memory (ROM) that stores various programs and maps in advance.
A random access memory (RAM) that temporarily stores CPU calculation results and the like.
A backup RAM that stores calculation results and prestored data.
-Timer counter and input interface.
-Output interface.

  Next, fuel injection amount control processing in the control executed by the engine ECU 6 in the present embodiment will be described. FIG. 2 shows a flowchart of the fuel injection amount control process. This process is executed by interruption every constant crank angle (every explosion stroke). The steps in the flowchart corresponding to individual processes are represented by “S˜”.

  When this process is started, first, the operation state of the diesel engine 2 is read by the sensors described above (S100). Then, calculation processing is executed based on the operation state read in step S100, and a basic required injection amount Q is calculated (S102). The calculation process of the basic required injection amount Q is calculated to be reflected in the basic required injection amount Q by calculating an increase / decrease of the injection amount so that the idle target rotation speed is realized at the time of idling. In addition, when the engine is not idling, the basic required injection amount Q is calculated by calculating the injection amount in consideration of the engine speed NE and the like so as to output the torque according to the driver's instruction by the accelerator opening ACCP. It is calculated to be reflected in.

Next, it is determined whether or not shifting is in progress (S104). If the speed is not being changed (“NO” in S104), then the injection amount upper limit value QFUL is calculated as in the following equation 1 (S106).
[Equation 1]
QFUL <-max (min (A, B), C) + D ... [Formula 1]
Here, the black smoke countermeasure calculation value A is a value set by a black smoke countermeasure control process (FIG. 3) to be described later, and a shift torque reduction calculation value B is a shift torque reduction control process (FIG. 4) to be described later. ). The minimum guard value C is a value for determining the minimum level of the injection amount upper limit value QFUL, and the offset value D is an offset value after guarding. Min (x, y) is an operator that means to extract the smaller one of x and y, and max (x, y) is to extract the larger of x and y. Is an operator that means

  Actually, since the gear is not being shifted at the time of the process of step S106, the value required for the torque reduction at the time of shifting is set to the calculated value B for the torque reduction at the time of shifting in the torque decreasing control process at the time of shifting (described later) The default value is large enough. For this reason, the calculated value A for black smoke countermeasures is sufficiently smaller than the calculated value B for torque reduction during shifting. Therefore, the calculated value A for black smoke countermeasures is extracted at min (A, B) and “QFUL = max (A, C) + D ”.

  Also, if the default value is set for both the black smoke countermeasure calculation value A and the shift torque reduction calculation value B, for example, if the shift torque reduction calculation value B is smaller at the default value, min In (A, B), the calculated torque reduction value B is extracted and becomes “QFUL = max (B, C) + D”. However, in this case, since the calculated torque reduction value B is sufficiently large, the injection amount upper limit value QFUL is also increased.

On the other hand, if the gear is being changed (“YES” in S104), the injection amount upper limit value QFUL is then calculated as in the following equation 2 (S108).
[Equation 2]
QFUL <-max (B, C) + D ... [Formula 2]
The value set for the black smoke countermeasure value A for the black smoke countermeasure is the value set for the torque down calculation value B for the gear shift torque reduction or the default value of the calculation value B for the torque reduction gear shift. A sufficiently small value is set in comparison with. Therefore, if the value for black smoke countermeasure is set to the calculation value A for black smoke countermeasure during gear shifting, if the above equation 1 is applied, the calculation for black smoke countermeasure is performed in “min (A, B)”. The value A is extracted and becomes “injection amount upper limit value QFUL = max (A, C) + D”.

  However, in the present embodiment, since the expression 2 is applied during the shift, the injection amount is independent of the value of the black smoke countermeasure calculation value A regardless of what value is set as the black smoke countermeasure calculation value A. An upper limit value QFUL is calculated. Accordingly, the black smoke countermeasure calculation value A is not affected by the injection amount upper limit value QFUL during gear shifting.

  When the injection amount upper limit value QFUL is calculated in step S106 or step S108, it is determined whether or not the basic required injection amount Q is larger than the injection amount upper limit value QFUL (S110). If Q> QFUL (“YES” in S110), the injection amount upper limit value QFUL is set as the final fuel injection amount QFINC (S112). If Q ≦ QFUL (“NO” in S110), the value of the basic required injection amount Q is set to the final fuel injection amount QFINC (S114).

  When the final fuel injection amount QFINC is obtained in step S112 or step S114, the injection period Tq for the fuel injection valve to be injected next time is calculated based on the final fuel injection amount QFINC and the fuel pressure Pf. (S116).

  In this way, this process is once completed. Thus, the fuel injection valve to be injected this time is opened based on the injection period Tq, and fuel corresponding to the final fuel injection amount QFINC is injected into the cylinder.

  Next, the black smoke countermeasure control process (FIG. 3) will be described. This process is a process executed by the engine ECU 6 and is executed before the fuel injection amount control process (FIG. 2). When this process is started, first, the time change amount DNE of the engine speed NE is read (S200). The engine speed change amount DNE is a value obtained by processing separately executed at a constant time period, and is a change amount at a constant time interval of the engine speed NE detected by the engine speed sensor. Equivalent to.

  Next, it is determined whether or not the engine speed time variation DNE is equal to or greater than the black smoke countermeasure determination value DNEpm (S202). Here, the black smoke countermeasure determination value DNEpm is a reference value for determining whether or not combustion has become unstable and black smoke is likely to be generated due to a rapid increase in the engine speed NE.

  If DNE <DNEpm (“NO” in S202), it is not necessary to execute black smoke suppression by reducing the fuel injection amount, so a default value is set for the calculated value A for black smoke countermeasures ( S204).

  On the other hand, if DNE ≧ DNEpm (“YES” in S202), it is necessary to suppress black smoke by reducing the fuel injection amount. Value is set. This black smoke countermeasure value is a value that can sufficiently suppress black smoke, and is sufficiently smaller than the default value.

In this way, this process is once completed.
Next, the torque reduction control process during shifting (FIG. 4) will be described. This process is a process executed by the shifting ECU 8, and is a process executed repeatedly in a short cycle. When this process is started, it is first determined whether or not the gear is being changed (S300). If the gear is not being shifted (“NO” in S300), it is not necessary to execute torque reduction during the gear shift, so a default value is set for the calculated value B for torque reduction during gear shifting (S302).

  On the other hand, if the gear is being changed (“YES” in S300), torque down timing is calculated (S304). This torque down timing indicates a period during which the shift shock is suppressed by torque down during the shift. The torque down timing is set based on, for example, the accelerator opening ACCP, the vehicle speed V, the turbine speed NT, the shift state, and the like. Specifically, the torque down start that starts in the inertia phase during the shift is performed. It consists of timing and torque down end timing.

  Next, it is determined whether or not it is a torque reduction execution timing (S306). That is, it is determined whether or not it is in a period from the start timing to the end timing. If it is not the torque-down execution timing (“NO” in S306), it is not necessary to execute torque-down yet, so a default value is set for the shift-time torque-down calculation value B (S302).

  If it is time to execute torque reduction (“YES” in S306), then a value required for torque reduction at the current shift is set as the torque-down calculated value B during shift (S308). For example, it is set based on the accelerator opening ACCP, the basic required injection amount Q, the vehicle speed V, the turbine speed NT, the shift state, and the like. The set calculated value B for torque reduction during shift is a value sufficiently smaller than the default value in step S302.

In this way, this process is once completed.
An example of the processing described above is shown in the timing chart of FIG. In the present embodiment, during the downshift with power-on indicated by the solid line (t0 to t5), the engine speed NE increases rapidly and the black smoke countermeasure calculation process (FIG. 3) calculates. The value A is set (S204: t2). However, in the fuel injection amount control process (FIG. 2), since a shift is being performed (“YES” in S104), step S108 is executed, and the injection amount upper limit value QFUL is obtained by the above equation 2. Therefore, the black smoke countermeasure calculation value A does not affect the level of the injection amount upper limit QFUL. Therefore, during gear shifting, the final fuel injection amount QFINC does not drop significantly as shown by the broken line (t2) for black smoke countermeasures, so fuel reduction for shifting-down torque reduction is also started early ( t3).

  Further, since the rotation state of the rotating member in the automatic transmission 4 is not disturbed by the fuel reduction to prevent black smoke, the rotation state of each rotating member in the automatic transmission 4 is as expected by the gear shifting ECU 8. Smoothly shifts to a state where shift shock can be prevented. Specifically, here, when the clutch inside the automatic transmission 4 is engaged (t3 to t5), the increase in the engine speed NE becomes loose, and the turbine speed NT (not shown) corresponding to this increases. Since the rise is loosened, there is less shock when the clutch is engaged.

  In the conventional example, the same calculation as in the above formula 1 (S106) is performed even during a shift, so the calculated value A for black smoke countermeasures set by the sudden increase in the engine speed NE during the shift is the level of the injection amount upper limit QFUL. As shown by the broken line from time t2, the final fuel injection amount QFINC is greatly reduced. As a result, the increase in the engine speed NE is delayed, and the increase in the turbine speed NT is also slowed. After that, however, when the fuel injection amount reduction for the black smoke countermeasure is completed, as shown by the broken line, the engine speed NE And the rotational speed of the turbine rotational speed NT increases. Therefore, the shift completion (t6) is delayed as compared with the case where the fuel reduction for black smoke countermeasures is not performed. At this time, even if the turbine rotational speed NT is observed and fuel reduction is performed to prevent shift shock as indicated by the broken line from time t4, the rotational state of each rotating member in the automatic transmission 4 remains in the shifting ECU 8. However, this is not necessarily the optimum state expected for preventing shift shock. Specifically, when the internal clutch of the automatic transmission 4 is engaged (t4 to t6), there is a period in which the engine speed NE increases rapidly as indicated by the broken line, and the turbine speed NT corresponds to this period. Since the rise of the speed is sudden, the shock at the time of clutch engagement becomes large. Therefore, there is a risk that the shift shock prevention will be insufficient.

  In the configuration described above, the engine speed sensor corresponds to the engine speed detecting means. Further, the black smoke countermeasure control process (FIG. 3) corresponds to the process as the black smoke prevention means, the shift ECU 8 corresponds to the shift control means, and the shift torque reduction control process (FIG. 4) corresponds to the process as the shift shock prevention means. To do. Further, steps S104 and S108 of the fuel injection amount control processing (FIG. 2) correspond to processing as black smoke prevention fuel injection amount reduction prohibiting means. Note that the calculation of “min (A, B)” in Equation 1 corresponds to the processing as the limiting means.

According to the first embodiment described above, the following effects can be obtained.
(I). In the fuel injection amount control process (FIG. 2), during the shift of the automatic transmission 4 (“YES” in S104), Equation 1 (S106) is not executed, and Equation 2 (S108) is executed. Reduction of fuel injection amount to prevent smoke is prohibited. For this reason, a decrease in engine output torque that disturbs the shift control by the shift ECU 8 does not occur. Therefore, when the combination of the rotating members in the automatic transmission 4 is switched in response to the torque reduction by the shift torque reduction control process (FIG. 4), the rotation state of the rotating members in the automatic transmission 4 is as follows. The speed change ECU 8 is in an expected state. For this reason, the combination of rotating members is switched at an appropriate timing, and a shift shock can be reliably prevented. As described above, in the diesel engine 2, even if the black smoke countermeasure control process (FIG. 3) and the shift torque reduction control process (FIG. 4) are executed, the shift shock prevention by the shift ECU 8 is not hindered.

  (B). Note that the prohibition of the fuel injection amount reduction for preventing black smoke by executing the formula 2 is temporary because the shift is being performed, and the influence on black smoke prevention is small. In addition, during this shift, the fuel injection amount is reduced by the shift torque-down control process (FIG. 4), so that black smoke tends to be suppressed even if the execution of Equation 1 is prohibited. There are few problems with prevention.

[Embodiment 2]
The present embodiment differs in that the fuel injection amount control process shown in FIG. 6 is executed instead of the fuel injection amount control process (FIG. 2) of the first embodiment. Other processes are the same as those in the first embodiment.

  The fuel injection amount control process (FIG. 6) will be described. In FIG. 6, steps S100, S102, and S106 to S116 are the same as the processing of the same step number described in FIG. The difference from FIG. 2 is that it is determined whether or not the shift-down torque-down calculation value B is being set after the calculation of the basic required injection amount Q (S102) (S105). That is, reduction of the fuel injection amount for preventing black smoke is not always prohibited during the shift, but reduction of the fuel injection amount for preventing black smoke is prohibited only during the setting of the calculation value B for torque reduction during the shift. become.

  An example of the processing described above is shown in the timing chart of FIG. Here, as shown by the solid line, the torque reduction start timing at the time of shifting is set earlier after the start of shifting (t10) compared to the first embodiment, depending on the characteristics or required performance of the diesel engine 2 or the automatic transmission 4. Shows the case. Then, the engine speed NE suddenly increased during the shift time torque reduction (t12 to t15), and the black smoke countermeasure calculation value A was set (S204: t13) in the black smoke countermeasure control process (FIG. 3). Suppose that is the case.

  In the fuel injection amount control process (FIG. 6), it is determined as “YES” in step S105, and step S108 is executed, whereby the injection amount upper limit value QFUL is calculated as shown in the equation 2 (S108). . Therefore, the black smoke countermeasure calculation value A does not affect the level of the injection amount upper limit value QFUL.

  Therefore, even during gear shifting, especially during gear shifting torque reduction, the final fuel injection amount QFINC is not greatly reduced to prevent black smoke, so that gear shifting control by the gear shifting ECU 8 is not disturbed. Therefore, as expected by the shifting ECU 8, the rotational state of each rotating member in the automatic transmission 4 smoothly shifts to a state in which a shift shock can be prevented. Specifically, here, when the internal clutch of the automatic transmission 4 is engaged (t12 to t17), the increase in the engine speed NE is generally slow, and the increase in the turbine speed NT is correspondingly increased. Since it becomes sluggish as a whole, there is little shock when the clutch is connected.

  In the conventional example, as indicated by the broken line, the final fuel injection amount QFINC significantly decreases during the shift time torque reduction as a measure against black smoke (S106: t13 to t14). Therefore, as indicated by the broken line, the engine speed NE increases. Is once slowed (from t13), and the increase in the turbine rotational speed NT is also slowed accordingly. However, after that, when the fuel injection amount reduction for the black smoke countermeasure is completed (t14), the engine speed NE and the turbine speed NT rapidly increase. Therefore, the shift control by the shift ECU 8 is disturbed. For this reason, the rotation state of each rotating member in the automatic transmission 4 is not always the optimum state expected by the shifting ECU 8 to prevent shift shock. Specifically, when the internal clutch of the automatic transmission 4 is engaged (t12 to t18), there is a period in which the engine speed NE increases rapidly as indicated by the broken line, and the turbine speed NT corresponds to this period. Since the rise of the speed is sudden, the shock at the time of clutch engagement becomes large. Therefore, there is a risk that the shift shock prevention will be insufficient. Further, since the shift completion (t18) is delayed as compared with the case where the fuel reduction for black smoke countermeasures is not performed, the shift period becomes longer.

In the configuration described above, steps S105 and S108 of the fuel injection amount control processing (FIG. 6) correspond to processing as black smoke prevention fuel injection amount reduction prohibiting means.
According to the second embodiment described above, the following effects can be obtained.

  (I). In the fuel injection amount control process (FIG. 6), while the torque reduction during shifting is being executed (“YES” in S105), Equation 1 (S106) is not executed, and Equation 2 (S108) is executed. The fuel injection amount reduction for black smoke prevention is prohibited. Therefore, the shift control by the shift ECU 8 is not disturbed, and a shift shock can be reliably prevented.

  In the case of the present embodiment, even if the gear is being shifted, if the torque reduction during shifting is not being executed (“NO” in S105), the fuel injection amount reduction for preventing black smoke is not prohibited. In this way, the state in which the fuel injection amount reduction for preventing black smoke is executed except when the torque reduction during the shift is not executed hardly affects the shift control, so that the shift shock can be sufficiently prevented. .

  (B). Note that the prohibition of execution of Equation 1 is temporary because the torque reduction during shifting is being executed, and has little influence on prevention of black smoke. In addition, since the fuel injection amount is reduced by the torque reduction during shifting at this time, black smoke tends to be suppressed even if the execution of Equation 1 is prohibited, so there is almost no problem in preventing black smoke. .

[Other embodiments]
(A). In the first embodiment, steps S104 to S108 of the fuel injection amount control process (FIG. 2) are replaced as shown in FIG. The degree of fuel injection amount reduction for smoke prevention may be reduced and corrected. That is, if the gear is not being shifted (“NO” in S104), the injection amount upper limit value QFUL is calculated as in the above-described equation 1 (S106). On the other hand, if shifting is in progress (“YES” in S104), a new black smoke countermeasure calculation value Ah is calculated from the black smoke countermeasure calculation value A as shown in the following equation 3 (S109a).

[Equation 3]
Ah ← A + dA ... [Formula 3]
Here, the correction value dA is a correction value for increasing the black smoke countermeasure calculation value A and setting it to the black smoke countermeasure calculation value Ah.

Then, the injection amount upper limit value QFUL is calculated as in the following expression 4 (S109b).
[Equation 4]
QFUL <-max (min (Ah, B), C) + D ... [Formula 4]
Here, the calculated torque reduction value B, the minimum guard value C, the offset value D, the operator min () and the operator max () are as described above. Further, when the calculated value A for black smoke countermeasures and the calculated value B for torque reduction during shifting are set in step S204 (FIG. 3) or step S308 (FIG. 4), A <B <Ah. The correction value dA is set in such a relationship.

  Therefore, as shown in the timing chart of FIG. 9, even during the shift (t20 to t25), it is possible to reduce the fuel for black smoke countermeasures (t22 to) by increasing the engine speed NE. However, the amount of reduction is less than the normal level when the speed change is not indicated by the broken line. Therefore, black smoke can be suppressed without significantly affecting the speed change control side. In FIG. 9, hatched portions (t23˜) indicate that B <Ah in Equation 4, that is, “min (Ah, B) = B”.

  With such a configuration, even if the black smoke countermeasure control process (FIG. 3) and the shift torque reduction control process (FIG. 4) are executed, the shift shock prevention by the shift ECU 8 is not hindered. In addition, during the shift, the fuel reduction for black smoke countermeasures only reduces the degree of reduction and does not stop the fuel reduction, so there is almost no problem in preventing black smoke.

  In this configuration, steps S104 and S109a in FIG. 8 correspond to processing as a black smoke prevention fuel injection reduction amount reducing means. Note that the calculation of “min (Ah, B)” in Equation 4 corresponds to processing as a limiting means.

  (B). In the second embodiment, as in the case (a), the steps S105 to S108 in FIG. 6 are replaced as shown in FIG. By increasing the calculated value A, the degree of fuel injection amount reduction for preventing black smoke may be corrected to decrease.

  However, in this example, if the calculated value A for black smoke countermeasures and the calculated value B for torque reduction during shifting are set in step S204 (FIG. 3) or step S308 (FIG. 4), respectively, A <Ah < The correction value dA is set in such a relationship as to be B.

  Therefore, as shown in the timing chart of FIG. 11, even during the torque reduction during the shift (t32 to t34), the fuel reduction for the black smoke countermeasure can be performed by increasing the engine speed NE (t33 to). However, the amount of reduction is less than the normal level when the speed change is not indicated by the broken line. Therefore, black smoke can be suppressed without significantly affecting the speed change control side. In FIG. 11, the hatched portion indicates a state in which Ah <B, that is, “min (Ah, B) = Ah” in the above-described Expression 4.

  With such a configuration, even if the black smoke countermeasure control process (FIG. 3) and the shift torque reduction control process (FIG. 4) are executed, the shift shock prevention by the shift ECU 8 is not hindered. In addition, during the torque reduction at the time of shifting, the fuel reduction for black smoke countermeasures only reduces the amount of reduction and does not stop the fuel reduction, so there is almost no problem in preventing black smoke.

In this configuration, steps S105 and S109a in FIG. 10 correspond to the processing as the black smoke prevention fuel injection reduction amount reducing means.
(C). In the second embodiment, steps S105 to S108 in FIG. 6 are replaced as shown in FIG. 12, so that during the torque reduction during shifting (“YES” in S105) You may restrict | limit the influence by the calculation value A for countermeasures. That is, if the calculated torque reduction value B is being set (“YES” in S105), it is next determined whether or not the following equation 5 is satisfied (S109c).

[Equation 5]
A <B × kb ... [Formula 5]
Here, the reduction coefficient kb is a value for decreasing the shift torque reduction calculation value B, and is set in a range of “0 <kb <1”, for example, “0.9”. That is, the above formula 5 determines whether the calculated value A for black smoke countermeasures is smaller than the calculated value B for torque reduction during shifting, and whether or not the relationship is more or less apart on the smaller side. It is.

  If Equation 5 is not satisfied (“NO” in S109c), the injection amount upper limit value QFUL is calculated by Equation 1 (S106). On the other hand, when the formula 5 is satisfied (“YES” in S109c), as shown in the following formula 6, the black smoke countermeasure calculated value Ah is calculated (S109d).

[Equation 6]
Ah ← B x kb [Formula 6]
Therefore, the black smoke countermeasure calculation value Ah is set to a value smaller than the shift torque-down calculation value B based on the shift torque-down calculation value B.

Next, the injection amount upper limit value QFUL is calculated as in the following equation 7 (S109e).
[Equation 7]
QFUL ← Ah + D ... [Formula 7]
By calculating the injection amount upper limit value QFUL in this way, the fuel reduction for the countermeasure against black smoke can be limited based on the calculated value B for torque reduction during shifting during the torque reduction during shifting. For example, using the timing chart of FIG. 11 described above, the bottom of the hatched portion (from t33) will not be smaller than the calculated shift-down torque-down calculation value B × kb at this time.

In this configuration, steps S105, S109c, S109d, and S109e of the fuel injection amount control process (FIG. 12) correspond to the process as the black smoke prevention fuel injection reduction amount limiting means.
(D). In the first embodiment, steps S104 to S108 of the fuel injection amount control process (FIG. 2) may be replaced as shown in FIG. As a result, when shifting is in progress (“YES” in S104) and the black smoke countermeasure calculation value A is set (FIG. 3: S204) (“YES” in S104a), min (A, B) By correcting the increase in the value of, the fuel injection amount reduction degree for preventing black smoke is substantially reduced. That is, when the gear is not being shifted (“NO” in S104) or when the calculation value A for black smoke countermeasures is not being set (“NO” in S104a), the injection amount upper limit value QFUL is calculated as in the above-described equation 1. (S106). On the other hand, if the gear is being shifted (“YES” in S104) and the calculation value A for black smoke countermeasure is being set (“YES” in S104a), the injection amount upper limit value QFUL is calculated as in the following equation 8 (S109f). ).

[Equation 8]
QFUL <-max (min (A, B) + [alpha], C) + D ... [Formula 8]
Here, the increase correction value α is a correction value that increases the calculation result of min (A, B). That is, the calculation of “min (A, B)” is normally selected as the black smoke countermeasure calculation value A in the situation where “YES” is determined in step S104a. Therefore, by calculating “min (A, B) + α”, the black smoke countermeasure calculation value A is substantially increased and corrected by the increase correction value α, and the fuel injection amount reduction degree for black smoke prevention is corrected to decrease. It will be.

Thus, the effect as described in the above (a) can be produced.
In this configuration, steps S104, S104a, and S109f in FIG. 13 correspond to the processing as the black smoke prevention fuel injection reduction amount reducing means. Note that the calculation of “min (A, B)” in Equation 8 corresponds to processing as a limiting means.

(E). In the second embodiment, steps S105 to S108 in FIG. 6 may be replaced as shown in FIG. Thus, when both the black smoke countermeasure calculation value A and the shift torque reduction calculation value B are set (“YES” in S105a), the value of min (A, B) is corrected to be increased. Thus, the fuel injection amount reduction degree for black smoke prevention is substantially corrected. That is, when both or one of the calculated value A for black smoke countermeasures and the calculated value B for torque reduction during shifting is not set ("NO" in S105a), the injection amount as in the above-described equation 1 An upper limit value QFUL is calculated (S106). On the other hand, if both the black smoke countermeasure calculation value A and the shift torque reduction calculation value B are set (“YES” in S105a), the injection amount upper limit value QFUL is calculated as shown in Equation 8 ( S109g).

  Even if both the calculated value A for black smoke countermeasures and the calculated value B for torque reduction during shifting are set, the calculation value A for black smoke countermeasures is normally selected in the calculation of “min (A, B)”. The Therefore, by calculating “min (A, B) + α”, the black smoke countermeasure calculation value A is substantially increased and corrected by the increase correction value α, and the fuel injection amount reduction degree for black smoke prevention is corrected to decrease. It will be.

Thus, the effect as described in the above (b) can be produced.
In this configuration, steps S105a and S109g in FIG. 14 correspond to processing as the black smoke prevention fuel injection reduction amount reducing means.

  (F). The offset value D for determining the injection amount upper limit value QFUL in each of the above embodiments is appropriately set according to the operating state of the diesel engine, but the offset value D may not be used.

  (G). In each of the embodiments described above, the fuel injection amount is reduced by adjusting the injection amount upper limit value QFUL. However, by directly executing the reduction correction for the fuel injection amount, the countermeasure for black smoke or at the time of shifting is performed. A fuel injection amount reduction for torque reduction may be executed.

1 is a block diagram showing a pressure accumulating diesel engine, an automatic transmission, and each ECU of the first embodiment. 3 is a flowchart of fuel injection amount control processing according to the first embodiment. 4 is a flowchart of black smoke countermeasure control processing according to the first embodiment. 5 is a flowchart of a torque reduction control process during shifting according to the first embodiment. 4 is a timing chart illustrating an example of processing according to the first embodiment. 7 is a flowchart of fuel injection amount control processing according to the second embodiment. 9 is a timing chart illustrating an example of processing according to the second embodiment. The flowchart which shows a part of fuel injection amount control process in other embodiment. The timing chart which shows an example of the process in other embodiment. The flowchart which shows a part of fuel injection amount control process in other embodiment. The timing chart which shows an example of the process in other embodiment. The flowchart which shows a part of fuel injection amount control process in other embodiment. The flowchart which shows a part of fuel injection amount control process in other embodiment. The flowchart which shows a part of fuel injection amount control process in other embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Diesel engine, 4 ... Automatic transmission, 4a ... Hydraulic control circuit, 6 ... ECU for engine, 8 ... ECU for transmission, 10 ... Various sensors.

Claims (4)

In a diesel engine that executes a fuel injection amount reduction process for preventing black smoke based on the engine speed and executes a fuel injection amount reduction process for preventing a shift shock during a shift of an automatic transmission,
Each of the fuel injection amount reduction processes is performed by reducing the upper limit value of the fuel injection amount, and a smaller upper limit value is selected from the upper limit values obtained by the two fuel injection amount reduction processes, and the selected upper limit value is selected. The fuel injection amount is limited based on the value, and when the shift of the automatic transmission is being performed and the fuel injection amount reduction process for preventing the black smoke is being executed, the selected upper limit value is increased and corrected. A method for controlling a diesel engine. In a diesel engine that executes a fuel injection amount reduction process for preventing black smoke based on the engine speed and executes a fuel injection amount reduction process for preventing a shift shock during a shift of an automatic transmission,
Each of the fuel injection amount reduction processes is performed by reducing the upper limit value of the fuel injection amount, and a smaller upper limit value is selected from the upper limit values obtained by the two fuel injection amount reduction processes, and the selected upper limit value is selected. The fuel injection amount is limited based on the value, and the fuel injection amount reduction process for preventing the shift shock and the fuel injection amount reduction process for preventing the black smoke are being executed. A diesel engine control method, wherein the upper limit value is corrected to be increased. Engine speed detecting means for detecting the engine speed of the diesel engine;
When the engine speed change detected by the engine speed detection means shows a change amount larger than the black smoke countermeasure determination value, the fuel injection amount is reduced to prevent black smoke by reducing the upper limit value of the fuel injection amount. Black smoke prevention means to perform,
Shift control means for controlling the shift of the automatic transmission;
Shift shock prevention means for performing fuel injection amount reduction for preventing shift shock by reducing the upper limit value of the fuel injection amount during shifting of the automatic transmission by the shift control means;
Limiting means for selecting a smaller upper limit value among the upper limit values set by the black smoke prevention means and the shift shock prevention means, and for limiting the fuel injection amount based on the selected upper limit value; ,
Black smoke prevention for increasing and correcting the upper limit value selected by the limiting means when the shift control means is shifting the automatic transmission and the fuel injection amount is being reduced by the black smoke prevention means. A fuel injection reduction amount reducing means;
A diesel engine control device comprising: Engine speed detecting means for detecting the engine speed of the diesel engine;
When the engine speed change detected by the engine speed detection means shows a change amount larger than the black smoke countermeasure determination value, the fuel injection amount is reduced to prevent black smoke by reducing the upper limit value of the fuel injection amount. Black smoke prevention means to perform,
Shift control means for controlling the shift of the automatic transmission;
Shift shock prevention means for performing fuel injection amount reduction for preventing shift shock by reducing the upper limit value of the fuel injection amount during shifting of the automatic transmission by the shift control means;
Limiting means for selecting a smaller upper limit value among the upper limit values set by the black smoke prevention means and the shift shock prevention means, and for limiting the fuel injection amount based on the selected upper limit value; ,
While both the shift shock prevention means and the black smoke prevention means are executing the fuel injection amount reduction, the black smoke prevention fuel injection reduction amount reduction means for increasing and correcting the upper limit value selected by the restriction means;
A diesel engine control device comprising:

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