JP2010106676A - Control device of vehicle with clutch mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a vehicle which can avoid the deterioration of drivability when an engine returns to fuel injection from fuel cut operation. <P>SOLUTION: The control device executes an ignition retard correction operation according to the intake air amount adjusted in response to a driving states of auxiliaries 21, 23 when returning to fuel injection from fuel cut operation in which lock-up clutch mechanism 12 is engaged and fuel injection is stopped. As an intake air amount is increased, an ignition retard correction amount of ignition plugs at return to fuel injection is increased. Thus, a sudden rise and slow rise in drive torque after the return to fuel injection can be avoided to improve drivability. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle including a clutch mechanism for connecting / disconnecting (disconnecting / engaging) an engine and a transmission. In particular, the present invention relates to an improvement in ignition timing control at the time of return from engine fuel cut operation (at the time of fuel injection return).

  2. Description of the Related Art Conventionally, a vehicle with a clutch mechanism that connects and disconnects an engine and a transmission is known, such as a vehicle in which a torque converter with a lock-up clutch is interposed between an engine and a transmission. In such a vehicle, the lock-up clutch is operated under a predetermined condition to perform lock-up that directly connects (engages) the engine and the transmission, resulting in torque transmission by fluid in the torque converter. The reduction of power transmission efficiency is suppressed.

  Further, in this type of vehicle, as disclosed in, for example, Patent Document 1 and Patent Document 2 below, if the state (lock-up state) in which the lock-up clutch is operated during vehicle deceleration is maintained, the drive wheels Since the rotation is directly transmitted to the engine and the rotation is maintained without operating the engine, the fuel cut region can be expanded to improve fuel efficiency.

  In particular, in a vehicle equipped with a continuously variable transmission (CVT) capable of continuously changing the gear ratio, the gear ratio can be continuously changed while the lock-up clutch is operated. The operation of the lockup clutch during deceleration of the vehicle can be maintained for a longer period of time, and the fuel cut area can be greatly expanded, thereby further improving fuel consumption.

  Further, when the engine is operating in the fuel cut operation region as described above, the engine speed decreases to a predetermined lower limit speed (the lower limit speed for preventing engine stall) or the driver depresses the accelerator pedal. When an operation is performed, the fuel cut operation state is returned to the normal operation state by fuel injection (fuel injection return).

Even if fuel injection is performed at the time of fuel injection recovery, if sufficient air amount is not secured in the cylinder, the necessary engine torque may not be obtained after fuel injection recovery. During the cutting operation, the intake air amount is adjusted in advance according to various parameters. For example, the intake air amount in this fuel cut operation region is set according to the vehicle speed, the operating state of the auxiliary machinery, and the like. The adjustment of the intake air amount is adjusted by the opening degree of the ISC valve provided in the passage for an engine having an ISC (Idle Speed Control) passage. It is adjusted by the opening of the throttle valve.
JP 2001-200987 A JP 2004-324437 A

  By the way, in the fuel cut operation state, the fuel is operated from the state in which the auxiliary machinery is operated and the intake air amount is adjusted to be relatively large, or the transmission gear ratio is set to be large. When the injection return operation is performed, there is a possibility that the drive torque transmitted to the drive wheels increases rapidly. For this reason, a return shock due to a sudden increase in the driving torque may occur, which may give the passenger an uncomfortable feeling.

  Conversely, in the fuel cut operation state, when the accessories are not operating and the intake air amount is adjusted to be relatively small, or the transmission gear ratio is set to be small. Even when the fuel injection return operation is performed, the drive torque transmitted to the drive wheels increases slowly. For this reason, insufficient acceleration of the vehicle (so-called acceleration stagnation) may occur, which may cause the driver to feel uncomfortable.

  The return shock and acceleration are caused by the fact that the vehicle acceleration at the time of fuel injection return is not properly obtained. Generally, this vehicle acceleration is given by the following equation (1).

Vehicle acceleration = (engine torque x total gear ratio x power transmission efficiency) /
(Tire effective radius x vehicle weight) (1)
Thus, conventionally, when fuel injection is returned from the fuel cut operation state, there is a possibility that a return shock or insufficient acceleration may occur depending on the state of the engine or transmission during the fuel cut operation. There was a possibility of leading to deterioration.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle control device capable of avoiding deterioration in drivability at the time of fuel injection return from the fuel cut operation of the engine. It is to provide.

-Principle of solving the problem-
The solution principle of the present invention taken in order to achieve the above object is that when fuel injection is returned from the fuel cut operation of the engine, depending on the state of the engine or transmission before the fuel injection return, The ignition timing of the spark plug is adjusted so that the drive torque after returning from fuel injection (torque output toward the drive wheels) is prevented from suddenly rising or slowing down.

-Solution-
Specifically, the present invention includes a clutch mechanism that disconnects / engages between the engine and the transmission, and engages the clutch mechanism and cuts the fuel of the engine when a predetermined fuel cut condition is satisfied. A control device for a vehicle with a clutch mechanism that restarts fuel injection of an engine when a predetermined fuel injection return condition is satisfied is assumed. With respect to the control device for a vehicle with a clutch mechanism, the physical quantity related to the output torque to the drive wheel after the fuel injection return is used as a parameter, and the physical quantity during the fuel cut execution increases the output torque after the fuel injection return. An ignition timing correction means for setting a larger ignition delay amount at the time of returning from fuel injection is provided.

  Due to this specific matter, the clutch mechanism is engaged when a predetermined fuel cut condition is satisfied (for example, when the vehicle decelerates when the accelerator pedal depression amount is “0” and the engine speed is equal to or higher than the predetermined speed). Thus, the engine and the transmission are directly connected, and the engine fuel cut is performed. As a result, the rotation of the drive wheels is directly transmitted to the engine, so that the rotation is maintained and the fuel consumption can be improved without operating the engine. When a predetermined fuel injection return condition (for example, when the engine speed decreases to a predetermined lower limit speed or when the driver depresses the accelerator pedal) is established after such fuel cut, the clutch mechanism The fuel injection of the engine is resumed (the fuel injection is restored) while the state is engaged. When the fuel injection is restored, the ignition retard amount is set to be larger as the physical quantity related to the output torque to the drive wheels after the fuel injection is restored increases the output torque after the fuel injection is restored. In other words, if there is a possibility that the output torque to the drive wheels will increase after the fuel injection is restored, the ignition retard amount is set to be large so that the engine torque at the time of the fuel injection restoration can be reduced. As a result, it is possible to avoid a sudden increase in the drive torque after returning from fuel injection and to prevent occurrence of a return shock. On the other hand, if there is a possibility that the output torque to the drive wheels will be relatively small after the fuel injection is restored, the engine torque at the time of the fuel injection restoration is not reduced by setting the ignition retard amount small. Thereby, sufficient engine torque can be obtained, insufficient acceleration of the vehicle can be resolved, and sufficient acceleration can be obtained for the vehicle. By adjusting the ignition retard amount in this way, it is possible to avoid a sudden increase or slow increase in the drive torque (torque output toward the drive wheels) after fuel injection is restored. Can be improved.

  Examples of the physical quantity related to the output torque to the drive wheel include the following. First, the physical quantity is used as the intake air quantity during the fuel cut of the engine. In this case, the ignition timing correcting means sets the ignition retard amount larger as the intake air amount during the fuel cut is larger.

  In other words, when fuel injection is restored when the intake air amount is large, the engine torque may become excessively high and cause a return shock. By setting the retard amount large, the engine torque can be appropriately limited, thereby preventing the return shock. Conversely, the smaller the intake air amount during the fuel cut, the smaller the ignition delay amount will be set. Therefore, the engine torque can be sufficiently obtained, the lack of acceleration of the vehicle is resolved, and the fuel injection is restored Acceleration slack can be avoided.

  Further, the physical quantity may be a transmission gear ratio during execution of fuel cut of the engine. In this case, the ignition timing correction means sets the ignition retard amount larger as the transmission gear ratio during the fuel cut is larger.

  In other words, if fuel injection is restored when the gear ratio of the transmission is large (low gear side), the output torque to the drive wheels may become too large and cause a return shock. However, according to the present solution, the engine torque is appropriately limited by setting the ignition retard amount large, thereby preventing the occurrence of return shock. Conversely, the smaller the gear ratio of the transmission during the fuel cut, the smaller the ignition delay amount will be set. Therefore, sufficient engine torque can be obtained, the vehicle's insufficient acceleration will be resolved, and fuel injection will be restored. It is possible to avoid slack in later acceleration.

  The ignition timing corrected by the ignition retardation amount set as described above may be further corrected by the engine speed. Specifically, the ignition timing correction unit corrects the ignition delay amount to be smaller as the engine speed is higher than the ignition delay amount set using the physical quantity as a parameter. Is.

  In other words, when the engine speed is high, the amount of rotation of the crankshaft per unit time increases. Therefore, if the ignition timing is corrected with the same ignition delay amount as when the engine speed is low, the combustion state in the combustion chamber There is a possibility that the engine torque will become worse or the engine torque will be smaller than the target torque. For this reason, the higher the engine speed, the smaller the ignition delay amount, and the ignition timing is set to the advance side than when the engine speed is low, thereby improving the combustion state in the combustion chamber and the target torque. Is to be obtained.

  Further, as described above, means for setting the ignition retard amount upon returning from the fuel injection and then returning the ignition retard amount to the original amount (ignition timing at which combustion is optimal) include the following. That is, as the ignition timing correction means sets the ignition delay amount at the time of fuel injection return larger, the return per unit period for returning the ignition delay amount after the fuel injection return to the original ignition delay amount. The ignition delay attenuation amount, which is the amount, is set to be small.

  If the ignition retard amount is set large in order to avoid a sudden increase in drive torque, if the ignition retard amount is immediately returned to the original value immediately thereafter, the drive torque may suddenly increase. is there. In addition, when the ignition retard amount is set to a small value in order to avoid a slow increase in drive torque, if the ignition retard amount is immediately returned to the original value, the drive torque increases thereafter. Can be slow. For this reason, in the present solution, a state in which a sudden increase in the drive torque can be avoided and a state in which the increase in the drive torque can be avoided for a predetermined period are continued for a predetermined period of time, thereby further improving drivability. I have to. In particular, when the ignition delay amount at the time of fuel injection return is set large, the deviation from the original ignition delay amount is large, so when the ignition delay amount at the time of fuel injection return is set small. Compared to the above, the ignition delay attenuation amount is set smaller (the return speed of the ignition delay amount is set lower) to ensure good drivability.

  In the present invention, when the fuel injection is returned from the fuel cut operation of the engine, the physical quantity related to the output torque to the drive wheels increases the output torque after the fuel injection is returned, so that The ignition retard amount is set large so that the engine torque becomes small. For this reason, at the time of fuel injection return, it becomes possible to appropriately obtain the engine torque corresponding to the physical quantity, and it is possible to avoid a sudden increase or slow increase in the drive torque after the fuel injection return. Can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

-Configuration of power transmission system-
FIG. 1 is a schematic configuration diagram illustrating a vehicle with a clutch mechanism and a control device thereof according to the present embodiment. First, the configuration of a power transmission system that transmits power between the engine 10 and the drive wheels 17 in this vehicle will be described.

  As shown in FIG. 1, a crankshaft (output shaft) 10 a of the engine 10 is connected to a torque converter 11. This torque converter 11 is a kind of fluid joint that transmits input rotation through fluid (oil), and appropriately adjusts the rotational torque of the crankshaft 10a by mediating fluid to drive wheel 17 side. To communicate.

  The torque converter 11 includes a lockup clutch mechanism 12. The lock-up clutch mechanism 12 operates based on hydraulic control by the hydraulic control circuit 19 and enables direct power transmission between the engine 10 side and the drive wheel 17 side of the torque converter 11.

  Further, the drive wheel 17 side of the torque converter 11 provided with such a lockup clutch mechanism 12 is connected to a forward / reverse switching mechanism 13 that reverses the direction of rotation input from the engine 10 side when the vehicle reverses, and further drives the torque converter 11. The wheel 17 side is connected to a transmission 14 for shifting. Therefore, the crankshaft 10a of the engine 10 and the transmission 14 are directly connected by the engagement of the lockup clutch mechanism 12, and the crankshaft 10a of the engine 10 and the transmission 14 are connected by the disengagement of the lockup clutch mechanism 12. I will be refused.

  Then, the lockup clutch mechanism 12 is operated to allow direct power transmission between the engine 10 and the transmission 14 without mediating the fluid (oil) of the torque converter 11, so-called “lockup”. To do. By executing such lock-up, it is possible to favorably avoid a reduction in power transmission efficiency due to torque transmission due to fluid in the torque converter 11 and improve the fuel consumption of the engine 10.

  In the vehicle of the present embodiment, a continuously variable transmission (CVT), in particular, a belt type CVT, in which the gear ratio can be continuously changed continuously is adopted as the transmission 14. The CVT 14 includes a driving pulley 14b and a driven pulley 14c that are connected to each other by a belt 14a wound around each other. The driving and driven pulleys 14b and 14c are configured so that the clamping width of the belt 14a can be changed by hydraulic pressure. Then, the transmission ratio is continuously changed by changing the clamping width of the belt 14a between the pulleys 14b and 14c and changing the winding radius of the belt 14a by the hydraulic control by the hydraulic control circuit 19. ing.

  In addition, the drive wheel 17 side of the CVT 14 is connected to a speed reduction mechanism 15 that transmits the rotation from the engine 10 side at a reduced speed, and a differential (differential device) 16 that allows the left and right drive wheels 17 to be differential. And connected to the drive wheel 17.

  Thus, power is transmitted between the engine 10 and the drive wheels 17 through the torque converter 11 including the lockup clutch mechanism 12, the CVT 14, and the like.

  On the other hand, the crankshaft 10a of the engine 10 can transmit power to the A / C compressor 21 that compresses the refrigerant of the air conditioner ("A / C"). Here, the rotation of the crankshaft 10 a of the engine 10 is transmitted to the A / C compressor 21 via the auxiliary belt 20. The operation / stop of the A / C compressor 21 is switched by selectively connecting / disconnecting the drive connection between the crankshaft 10a and the A / C compressor 21 by the electromagnetic clutch 22.

  The auxiliary belt 20 is also stretched over a generator (alternator) 23. That is, power is generated by transmitting the driving force from the engine 10 to the generator 23 via the auxiliary belt 20. In addition to the A / C compressor 21 and the generator 23 described above, various auxiliary machines (not shown) are wound around the auxiliary belt 20.

-Engine-
FIG. 2 is a diagram showing a schematic configuration of the engine 10 and its intake and exhaust system according to the present embodiment. In FIG. 2, only the configuration of one cylinder of the engine 10 is shown.

  The engine 10 in this embodiment is, for example, a four-cylinder gasoline engine, and includes a piston 42 that forms a combustion chamber 41 and the crankshaft 10a. The piston 42 is connected to the crankshaft 10 a via a connecting rod 44, and the reciprocating motion of the piston 42 is converted into rotation of the crankshaft 10 a by the connecting rod 44.

  A signal rotor 45 having a plurality of protrusions (teeth) 46 on the outer peripheral surface is attached to the crankshaft 10a. A crank position sensor (engine speed sensor) 31 is disposed near the side of the signal rotor 45. The crank position sensor 31 is, for example, an electromagnetic pickup, and generates a pulse-like signal (output pulse) corresponding to the protrusion 46 of the signal rotor 45 when the crankshaft 10a rotates.

  The cylinder block 47 of the engine 10 is provided with a water temperature sensor 32 that detects the engine water temperature (cooling water temperature).

  A spark plug 2 is disposed in the combustion chamber 41 of the engine 10. The ignition timing (ignition timing) of the spark plug 2 is adjusted by the igniter 2a. The igniter 2 a is controlled by an ECU (Electronic Control Unit) 30.

  The ECU 30 is an engine ECU that controls the engine 10 such as fuel injection control and ignition timing control, a CVT ECU that controls the CVT 14 and the lockup clutch mechanism 12 based on the operation control of the hydraulic control circuit 19, The electronic circuit group includes an A / C ECU for controlling A / C such as operating / stopping the / C compressor 21.

  An intake passage 3 and an exhaust passage 4 are connected to the combustion chamber 41 of the engine 10. An intake valve 3a is provided between the intake passage 3 and the combustion chamber 41, and the intake passage 3 and the combustion chamber 41 are communicated or blocked by opening and closing the intake valve 3a. Further, an exhaust valve 4a is provided between the exhaust passage 4 and the combustion chamber 41, and the exhaust passage 4 and the combustion chamber 41 are communicated or blocked by opening and closing the exhaust valve 4a. The opening / closing drive of the intake valve 3a and the exhaust valve 4a is performed by each rotation of the intake camshaft and the exhaust camshaft (both not shown) to which the rotation of the crankshaft 10a is transmitted.

  In the intake passage 3, an air cleaner 3b, a hot-wire air flow meter 33, an intake air temperature sensor 36 (built in the air flow meter 33), and an electronically controlled throttle valve 3c for adjusting the intake air amount of the engine 10 are arranged. ing. The throttle valve 3c is driven by a throttle motor 3d. The opening degree of the throttle valve 3 c is detected by a throttle opening degree sensor 37.

A three-way catalyst 4 b is disposed in the exhaust passage 4 of the engine 10. The three-way catalyst 4b has an O ₂ storage function (oxygen storage function) for storing (occluding) oxygen. Even if the air-fuel ratio shifts from the stoichiometric air-fuel ratio to a certain extent by this oxygen storage function, HC, CO and NOx can be purified. That is, when the air-fuel ratio of the engine 10 becomes lean and oxygen and NOx in the exhaust gas flowing into the three-way catalyst 4b increase, the three-way catalyst 4b occludes part of the oxygen, thereby reducing and purifying NOx. Promote. On the other hand, when the air-fuel ratio of the engine 10 becomes rich and the exhaust gas flowing into the three-way catalyst 4b contains a large amount of HC and CO, the three-way catalyst 4b releases the oxygen molecules stored therein, Oxygen molecules are given to these HC and CO to promote oxidation and purification.

  An air-fuel ratio sensor (A / F sensor) 38 is disposed in the exhaust passage 4 on the upstream side of the three-way catalyst 4b. For example, a limiting current type oxygen concentration sensor is applied to the air-fuel ratio sensor 38, and an output voltage corresponding to the air-fuel ratio is generated over a wide air-fuel ratio region.

An oxygen sensor (O ₂ sensor) 39 is disposed in the exhaust passage 4 on the downstream side of the three-way catalyst 4b. As the oxygen sensor 39, for example, an electromotive force type (concentration cell type) oxygen concentration sensor is applied.

  The signals generated by the air-fuel ratio sensor 38 and the oxygen sensor 39 are A / D converted and then input to the ECU 30.

  An injector 3e for fuel injection is disposed in the intake passage 3. Fuel of a predetermined pressure is supplied from the fuel tank to the injector 3e by a fuel pump, and the fuel is injected into the intake passage 3. This injected fuel is mixed with intake air to form an air-fuel mixture and introduced into the combustion chamber 41 of the engine 10. The air-fuel mixture (fuel + air) introduced into the combustion chamber 41 undergoes a compression stroke of the engine 10 and is then ignited by the spark plug 2 to burn and explode. Due to the combustion / explosion of the air-fuel mixture in the combustion chamber 41, the piston 42 reciprocates and the crankshaft 10a rotates.

-Description of control block-
The operating state of the engine 10 is controlled by the ECU 30. As shown in FIG. 3, the ECU 30 includes a CPU (Central Processing Unit) 30a, a ROM (Read Only Memory) 30b, a RAM (Random Access Memory) 30c, a backup RAM 30d, and the like.

  The ROM 30b stores various control programs, maps that are referred to when the various control programs are executed, and the like.

  The CPU 30a executes arithmetic processing based on various control programs and maps stored in the ROM 30b.

  The RAM 30c is a memory that temporarily stores calculation results in the CPU 30a, data input from each sensor, and the like.

  The backup RAM 30d is a non-volatile memory that stores data to be saved when the engine 10 is stopped.

  The ROM 30b, the CPU 30a, the RAM 30c, and the backup RAM 30d are connected to each other via the bus 30e, and are connected to the external input circuit 30f and the external output circuit 30g.

  In addition to the crank position sensor 31, the water temperature sensor 32, the air flow meter 33, the intake air temperature sensor 36, the throttle opening sensor 37, the air-fuel ratio sensor 38, the oxygen sensor 39, the external input circuit 30f includes an accelerator opening sensor 35, A cam angle sensor 3A, a knock sensor 3B, a vehicle speed sensor 3C, a temperature sensor 3D, an input shaft rotational speed sensor 3E, an output shaft rotational speed sensor 3F, and the like are connected. On the other hand, the external output circuit 30g is connected to a throttle motor 3d for driving the throttle valve 3c, the injector 3e, the igniter 2a, the hydraulic control circuit 19, and the like.

  The crank position sensor 31 is disposed in the vicinity of the crankshaft 10a as described above, and detects the rotation angle (crank angle CA) and the rotation speed (engine speed Ne) of the crankshaft 10a.

  The water temperature sensor 32 detects the temperature of the cooling water flowing in the water jacket 47 a formed in the cylinder block 47 and transmits the cooling water temperature signal to the ECU 30.

  The air flow meter 33 detects the intake air amount and transmits the intake air amount signal to the ECU 30.

  The intake air temperature sensor 36 is provided integrally with the air flow meter 33, detects the intake air temperature, and transmits the intake air temperature signal to the ECU 30.

  The throttle opening sensor 37 detects the opening of the throttle valve 3c and transmits the throttle opening signal to the ECU 30.

  The air-fuel ratio sensor 38 generates an output voltage corresponding to the air-fuel ratio of the exhaust discharged from the combustion chamber 41 (exhaust on the upstream side of the three-way catalyst 4b), and transmits the output voltage signal to the ECU 30.

  The oxygen sensor 39 generates an output voltage corresponding to the oxygen concentration of the exhaust gas downstream of the three-way catalyst 4b, and transmits the output voltage signal to the ECU 30.

  The accelerator opening sensor 35 detects the opening (operation amount) of the accelerator pedal 35a operated by the driver, and transmits the opening signal to the ECU 30.

  The cam angle sensor 3A is disposed in the vicinity of the intake camshaft, and is used as a cylinder discrimination sensor by outputting a pulse signal corresponding to the compression top dead center (TDC) of the first cylinder, for example. That is, the cam angle sensor 3A outputs a pulse signal for each rotation of the intake camshaft. As an example of a cam angle detection method using this cam angle sensor, external teeth are formed at one location on the outer peripheral surface of the rotor integrally formed with the intake camshaft, and the external teeth are opposed to each other by an electromagnetic pickup. The cam angle sensor 3A is arranged, and when the external teeth pass near the cam angle sensor 3A as the intake cam shaft rotates, the cam angle sensor 3A generates an output pulse. Since this rotor rotates at half the rotational speed of the crankshaft 10a, an output pulse is generated every time the crankshaft 10a rotates 720 °. In other words, an output pulse is generated each time a specific cylinder reaches the same stroke (for example, when the first cylinder reaches compression top dead center).

  The knock sensor 3B is a vibration sensor that detects the vibration of the engine transmitted to the cylinder block 47 by a piezoelectric element type (piezo element type) or an electromagnetic type (magnet, coil).

  The vehicle speed sensor 3 </ b> C is provided on a drive shaft connected to the drive wheels 17, detects the traveling speed of the vehicle, and transmits a vehicle speed signal (SPD) to the ECU 30.

  The temperature sensor 3D detects the internal temperature (cooling temperature “TE”) of an evaporator (not shown) through which the refrigerant cooled as the A / C compressor 21 operates.

  The input shaft rotation speed sensor 3E detects the rotation speed of the input shaft of the transmission 14, and transmits the rotation speed signal to the ECU 30.

  The output shaft rotational speed sensor 3F detects the rotational speed of the output shaft of the transmission 14, and transmits the rotational speed signal to the ECU 30. The gear ratio in the transmission 14 can be obtained from the ratio between the rotational speed of the output shaft and the rotational speed of the input shaft. In addition, as a method for obtaining the speed ratio in the transmission 14, instead of obtaining the speed ratio from the rotation speed of the output shaft and the rotation speed of the input shaft, the speed ratio is determined by detecting the belt position of the transmission 14. You may make it ask.

  The ECU 30 executes various controls of the engine 10 based on the detection signals of the various sensors described above. For example, the oxygen concentration in the exhaust gas is calculated based on the outputs of the air-fuel ratio sensor 38 and the oxygen sensor 39 disposed in the exhaust passage 4 of the engine 10, and the actual air-fuel ratio obtained from the calculated oxygen concentration is the target air-fuel ratio. “Air-fuel ratio feedback control” is executed to control the fuel injection amount injected from the injector 3e into the intake passage 3 so as to coincide with the fuel ratio (for example, the theoretical air-fuel ratio).

  On the other hand, to the output port of the ECU 30, various actuators related to the control of the engine 10, the hydraulic control circuit 19, driving circuits for driving the A / C compressor 21, the generator 23, and the like are connected. The ECU 30 also executes operation control of the engine 10 such as fuel injection, shift control of the CVT 14 by controlling the hydraulic control circuit 19 and operation control of the lockup clutch mechanism 12 based on the outputs of the various sensors. Further, the ECU 30 executes the operation control of the A / C compressor 21 as part of the air conditioner control.

-Fuel cut operation-
Next, the fuel cut operation of the engine 10 will be described. As described above, if the lock-up clutch mechanism 12 is engaged during deceleration of the vehicle, power is directly transmitted from the drive wheels 17 to the engine 10 side, so that the engine speed can be increased without operating the engine 10. The rotation is raised above the idle rotation speed and the rotation is maintained. Therefore, when the fuel cut is performed while the vehicle is decelerating, if the lock-up clutch mechanism 12 is engaged, the fuel cut region can be expanded to improve the fuel consumption.

  In particular, in a vehicle equipped with the CVT 14 as in the present embodiment, continuous shift can be performed while the lockup clutch mechanism 12 is operated. It is possible to maintain the engagement and further enlarge the fuel cut region.

  Therefore, in the present embodiment, when the accelerator pedal 35a is turned off (depression amount “0”) and the vehicle is decelerated, the fuel cut of the engine 10 is performed and the lockup clutch mechanism 12 is engaged. The fuel cut area is expanded.

  On the other hand, as the vehicle is decelerated, the gear ratio of the CVT 14 is set to the low side (side to increase the gear ratio) in order to ensure power performance during reacceleration. Therefore, even if the speed of the vehicle is lower than a certain level, if the speed ratio of the transmission 14 is increased while the operation of the lockup clutch mechanism 12 is maintained, the engine speed does not cause engine stall. Can be maintained.

  During fuel cut operation in such a lock-up state, even if fuel injection is executed at the time of fuel injection return, if a sufficient amount of air is not secured in the cylinder, the engine required after fuel injection return Since torque may not be obtained, the intake air amount is adjusted in advance according to various parameters during the fuel cut operation. This will be specifically described below.

  The vehicle speed detected by the vehicle speed sensor 3C, the intake air amount detected by the air flow meter 33, the input shaft rotational speed of the transmission 14 and the output shaft rotational speed detected by the input shaft rotational speed sensor 3E. The gear ratio in the transmission 14 obtained from the difference from the output shaft rotational speed of the transmission 14 detected by the sensor 3F, the engine rotational speed obtained based on the output signal of the crank position sensor 31 and the input shaft rotational speed. The state (disengaged state or engaged state) of the lockup clutch mechanism 12 obtained from the difference from the output input rotation number of the transmission 14 detected by the number sensor 3E, and the accelerator pedal detected by the accelerator opening sensor 35 Various signals of the opening degree of 35a, and further, operating state signals of various auxiliary machines are input to the ECU 30, and this CU30 sets the intake air amount in the fuel cut operation during running on the basis of these various signals. This intake air amount is adjusted by the opening degree of the throttle valve 3c. In the case of an engine having an ISC passage, the intake air amount is adjusted by the opening degree of an ISC valve provided in the passage.

  On the other hand, even if the speed ratio of the transmission 14 is set to the maximum speed ratio, the engine speed decreases to a predetermined lower limit speed (lower limit speed for preventing engine stall: 600 rpm, for example) When the step 35a is depressed, the fuel injection return condition is satisfied, and the fuel cut operation state is returned to the normal operation state by fuel injection (fuel injection return).

-Adjustment control of ignition delay amount-
The feature of the present embodiment lies in the operation when the fuel injection return condition is satisfied during the fuel cut operation and the fuel injection is resumed from the injector 3e. Specifically, the fuel injection return is performed according to the intake air amount during the fuel cut operation (intake air amount adjusted according to the various parameters) and the gear ratio of the transmission 14 during the fuel cut operation. The purpose is to adjust the ignition retardation amount of the spark plug 2 at the time. More specifically, the ignition delay amount of the spark plug 2 at the time of fuel injection return is adjusted according to the intake air amount during execution of the fuel cut operation immediately before the fuel injection is returned and the gear ratio of the transmission 14. is there. The intake air amount and the transmission gear ratio of the transmission 14 are the “physical amount related to the output torque to the drive wheels” in the present invention.

  Hereinafter, a plurality of embodiments of the adjustment control of the ignition delay amount of the spark plug 2 at the time of fuel injection return will be described.

(First embodiment)
First, the first embodiment will be described. In the present embodiment, the ignition retardation amount of the spark plug 2 at the time of return of fuel injection is adjusted according to the intake air amount during execution of the fuel cut operation of the engine. This will be specifically described below.

  FIG. 4 is a basic ignition retard amount determination map for determining the basic ignition retard amount of the spark plug 2. The basic ignition delay amount determined by the basic ignition delay amount determination map is to prevent the engine 10 from misfiring and to increase the exhaust gas temperature excessively when the combustion is performed continuously (steady). An ignition timing (an ignition timing at which combustion is optimal) that can be suppressed to protect the three-way catalyst 4b is set.

  As shown in this basic ignition retardation amount determination map, there is a correlation between the engine speed and the air amount load factor (the actual intake air amount when the intake air amount when the throttle valve 3c is fully opened is 100%). Value) determines the basic ignition retardation amount of the spark plug 2. Basically, the basic ignition delay amount is set to increase as the air load factor increases, and the basic ignition delay amount is set to decrease as the engine speed increases. In exceptional cases, in the engine medium load range (engine speed is 800 to 1600 rpm) and in the region where the air amount load factor is relatively high (region of 40% or more), the higher the air amount load factor, the basic ignition delay angle. I try to reduce the amount. This is to improve the combustion state in the combustion chamber 41. Further, in FIG. 4, the negative side is shown as the ignition retard side.

  For example, when the engine speed is 800 rpm and the air load factor is 10%, the ignition timing is shifted by 5 ° (CA) to the retard side with respect to the compression top dead center (TDC) of the piston 42 ( The basic ignition retardation amount is obtained as ATDC 5 °. When the engine speed is 800 rpm and the air load factor is 20%, the ignition timing is shifted by 10 ° (CA) to the retard side with respect to the compression top dead center (TDC) of the piston 42 ( The basic ignition retardation amount is obtained as ATDC 10 °.

  In this embodiment, when the fuel injection is returned from the fuel cut operation, the A / C compressor 21 and the generator 23 are supplemented with respect to the basic ignition delay amount obtained by the basic ignition delay amount determination map. Depending on the driving state (ON / OFF) of the machine, either the first retardation amount calculation map shown in FIG. 5 or the second retardation amount calculation map shown in FIG. 6 is selected, and this selected retardation angle is selected. The effective ignition retard amount is determined by correcting the basic ignition retard amount according to the amount calculation map (ignition retard amount setting operation by the ignition timing correcting means).

  The first retardation amount calculation map is a map that is selected when the above-described auxiliary devices are turned on and the engine load by the auxiliary devices is large. On the other hand, the second retardation amount calculation map is a map that is selected when the auxiliary machinery is turned off and the engine load by the auxiliary machinery is small or “0”.

  As described above, the intake air amount during execution of the fuel cut operation is set according to the driving state of the auxiliary machinery, and when the engine load by the auxiliary machinery is large, the intake air amount is increased so that the intake air amount increases. The opening is adjusted. For this reason, when the auxiliary machinery is turned on and the intake air amount is large during execution of the fuel cut operation, the first retardation amount calculation map is selected. The ignition retardation correction amount in the first retardation amount calculation map is larger than the ignition retardation correction amount in the second retardation amount calculation map (in the retardation amount calculation map, the correction to the retard side is performed). When the first retard amount calculation map is selected, the ignition timing of the spark plug 2 is greatly corrected to the retard side. Further, in this first retard amount calculation map, the ignition retard correction amount is also changed depending on the engine speed. That is, the ignition delay amount is set to be smaller as the engine speed is higher.

  On the other hand, when the auxiliary machinery is turned off and the intake air amount is small during execution of the fuel cut operation, the second retardation amount calculation map is selected. The ignition retardation correction amount in the second retardation amount calculation map is smaller than the ignition retardation correction amount in the first retardation amount calculation map, and this second retardation amount calculation map is selected. In this case, the correction to the retard side is reduced as the ignition timing of the spark plug 2. Even in the second retard amount calculation map, the ignition retard correction amount is changed according to the engine speed. That is, the ignition delay amount is set to be smaller as the engine speed is higher.

  More specifically, execution ignition is performed by subtracting the ignition delay correction amount obtained by any of the retard amount calculation maps from the basic ignition retard amount obtained by the basic ignition retard amount determination map. The amount of retardation is determined. If the ignition retard correction amount obtained from the retard amount calculation map is a positive value, a positive value is subtracted from the basic ignition retard amount, so the effective ignition retard amount is subtracted. Is obtained as a value on the retard side with respect to the basic ignition retard amount. Conversely, if the ignition retard correction amount obtained in the retard amount calculation map is a negative value, the negative value is subtracted from the basic ignition retard amount, so the effective ignition retard The amount is obtained as a value on the advance side with respect to the basic ignition retardation amount.

  FIG. 7 shows a flowchart for obtaining the effective ignition retard amount when the fuel injection is returned from the fuel cut operation. This flowchart is executed every predetermined time or every predetermined rotation angle of the crankshaft 10a during execution of the fuel cut operation.

  First, in step ST1, it is determined whether or not a fuel injection return condition is satisfied during execution of the fuel cut operation. As described above, the fuel injection return condition is when the engine speed decreases to a predetermined lower limit speed (lower limit speed for preventing engine stall) or when the driver depresses the accelerator pedal 35a. Is established. If the fuel injection return condition is not satisfied and NO is determined in step ST1, this routine is temporarily ended.

  On the other hand, if the fuel injection return condition is satisfied during the fuel cut operation and the determination in step ST1 is YES, the process proceeds to step ST2, and the current fuel injection return condition is satisfied. ) Is detected, and it is determined whether or not the auxiliary devices are in a driving state, that is, the engine load is high.

  And when the said auxiliary machinery is turned ON and the engine load by this auxiliary machinery is large, YES determination is carried out at step ST2, and it moves to step ST3.

  In this step ST3, the first retardation amount calculation map is selected, and the basic ignition retardation amount obtained in advance by the engine speed and the air amount load factor in accordance with the basic ignition retardation amount determination map, The ignition retardation amount is corrected by the ignition retardation correction amount determined according to the engine speed by the first retardation amount calculation map, thereby calculating the effective ignition retardation amount (effective ignition retardation amount = basic). Ignition retardation amount−ignition retardation correction amount).

  In step ST3, the ignition retardation attenuation amount is also determined. The ignition delay attenuation amount is a return amount of the ignition timing (a return amount toward the basic ignition delay amount) per unit period after the ignition with the effective ignition delay amount is executed. In step ST3, the ignition delay attenuation amount is set to be relatively small (so that the return speed toward the basic ignition delay amount is reduced). Specifically, after ignition is performed five times with the effective ignition delay amount, the ignition timing is increased by 3 ° (CA) by one ignition until the optimum combustion timing (for example, toward the advance side). Set to go back. These values are not limited to this. With this ignition retardation attenuation amount, combustion advances to the optimal ignition timing.

  On the other hand, if it is determined in step ST2 that the accessories are turned off and the engine load due to the accessories is small, a determination of NO is made in step ST2 and the process proceeds to step ST4.

  In this step ST4, the second retardation amount calculation map is selected, and the basic ignition retardation amount determined in advance by the engine speed and the air amount load factor according to the basic ignition retardation amount determination map, The ignition retardation amount is corrected by the ignition retardation correction amount determined according to the engine speed by the second retardation amount calculation map, thereby calculating the effective ignition retardation amount (effective ignition retardation amount = basic). Ignition retardation amount−ignition retardation correction amount).

  Also in this step ST4, the ignition retardation attenuation amount is determined. In step ST4, the ignition delay attenuation amount is set to be larger than that in step ST3 (the return speed toward the basic ignition delay amount is increased). Specifically, after ignition is performed five times with the effective ignition delay amount, the ignition timing is increased by 5 ° (CA) for each ignition until the optimal combustion timing (for example, toward the advance side). Set to go back. These values are not limited to this. With this ignition retardation attenuation amount, combustion advances to the optimal ignition timing.

  The fuel injection is resumed (fuel injection is resumed) while the ignition control of the spark plug 2 is performed according to the effective ignition delay amount and ignition delay attenuation amount thus obtained.

  FIG. 8 is a timing chart showing changes in the fuel cut execution flag, the ignition timing, the engine torque, and the vehicle longitudinal G when the ignition delay amount and the ignition delay attenuation amount are set as in the present embodiment. The broken lines in the figure indicate that the auxiliary equipment is turned on and the engine load by the auxiliary equipment is large, that is, the effective ignition retard amount is set large and the ignition retard attenuation amount is set small. The change in the case (change in the effective ignition delay amount and the ignition delay attenuation amount set in step ST3 in the flowchart) is shown. Also, the solid line in the figure indicates that when the auxiliary equipment is turned off and the engine load by the auxiliary equipment is small, that is, the effective ignition delay amount is set small and the ignition delay attenuation amount is large. The change when set (change in the effective ignition retard amount and the ignition retard amount set in step ST4 in the flowchart) is shown.

  As can be seen from FIG. 8, the engine torque after the return of fuel injection is higher when the auxiliary equipment is turned on, and the engine torque corresponding to the engine load by the auxiliary equipment is obtained. It has been. That is, the engine torque that contributes to the driving force of the vehicle is sufficiently obtained as substantially the same torque regardless of whether the auxiliary machinery is turned on or off. In addition, the vehicle front and rear G after the fuel injection return is stably obtained regardless of the driving state of the auxiliary machines, and the drive torque (torque output toward the drive wheels 17) after the fuel injection return sharply increases. It is possible to avoid the slow rise and slow rise, and the drivability is improved. In the change in the vehicle front-rear G in FIG. 8, the difference between the solid line and the broken line is the friction due to the driving of the accessories, and after the fuel injection is restored, the engine torque corresponding to the friction is increased. Therefore, the vehicle front-rear G is substantially the same vehicle front-rear G both when the auxiliary equipment is turned on and when it is turned off.

(Second Embodiment)
Next, a second embodiment will be described. In the present embodiment, the ignition delay amount of the spark plug 2 at the time of return of fuel injection is adjusted according to the gear ratio of the transmission 14 during execution of the fuel cut operation of the engine. This will be specifically described below.

  Also in the present embodiment, as in the case of the first embodiment described above, the basic ignition retard amount determination map shown in FIG. 4, the first retard amount calculation map shown in FIG. 5, and the second retard angle shown in FIG. The effective ignition retard amount is determined using the amount calculation map.

  That is, when the gear ratio of the transmission 14 is large (on the low gear side) during execution of the fuel cut operation, the first retardation amount calculation map is selected. As described above, the ignition retardation correction amount in the first retardation amount calculation map is larger than the ignition retardation correction amount in the second retardation amount calculation map, and this first retardation amount calculation map is If selected, the ignition timing of the spark plug 2 is largely corrected to the retard side.

  Conversely, when the gear ratio of the transmission 14 is small (on the high gear side) during the fuel cut operation, the second retardation amount calculation map is selected. As described above, the ignition retardation correction amount in the second retardation amount calculation map is smaller than the ignition retardation correction amount in the first retardation amount calculation map, and this second retardation amount calculation map is When selected, the correction to the retard side is reduced as the ignition timing of the spark plug 2.

  As described above, also in this embodiment, the ignition retard correction amount obtained by any of the retard amount calculation maps is subtracted from the basic ignition retard amount obtained by the basic ignition retard amount determination map. The execution ignition retard amount is determined by the above.

  FIG. 9 shows a flowchart for obtaining the effective ignition retard amount when the fuel injection is returned from the fuel cut operation. This flowchart is also executed every predetermined time or every predetermined rotation angle of the crankshaft 10a during execution of the fuel cut operation.

  First, in step ST1, it is determined whether or not a fuel injection return condition is satisfied during execution of the fuel cut operation. If the fuel injection return condition is not satisfied and NO is determined in step ST1, this routine is temporarily ended.

  On the other hand, if the fuel injection return condition is satisfied during the fuel cut operation and the determination in step ST1 is YES, the process proceeds to step ST2 ′, where the fuel injection return condition is satisfied and the fuel is still It is determined whether or not the gear ratio of the transmission 14 at a timing (when injection is not started) is greater than a predetermined gear ratio (for example, “1.0”) (a state on the low gear side). This value is not limited to this.

  If the speed ratio of the transmission 14 is greater than the predetermined speed ratio, a YES determination is made in step ST2 'and the process proceeds to step ST3.

  In this step ST3, the first retardation amount calculation map is selected, and the basic ignition retardation amount obtained in advance by the engine speed and the air amount load factor in accordance with the basic ignition retardation amount determination map, The ignition retardation amount is corrected by the ignition retardation correction amount determined according to the engine speed by the first retardation amount calculation map, thereby calculating the effective ignition retardation amount (effective ignition retardation amount = basic). Ignition retardation amount−ignition retardation correction amount).

  In step ST3, the ignition retard attenuation amount is set to be relatively small (the return speed toward the basic ignition retard amount is reduced). Specifically, after ignition is performed five times with the effective ignition delay amount, the ignition timing is increased by 3 ° (CA) by one ignition until the optimum combustion timing (for example, toward the advance side). Set to go back. These values are not limited to this.

  On the other hand, if it is determined in step ST2 'that the speed ratio of the transmission 14 is smaller than the predetermined speed ratio, NO is determined in step ST2' and the process proceeds to step ST4.

  In this step ST4, the second retardation amount calculation map is selected, and the basic ignition retardation amount determined in advance by the engine speed and the air amount load factor according to the basic ignition retardation amount determination map, The ignition retardation amount is corrected by the ignition retardation correction amount determined according to the engine speed by the second retardation amount calculation map, thereby calculating the effective ignition retardation amount (effective ignition retardation amount = basic). Ignition retardation amount−ignition retardation correction amount).

  Also in this step ST4, the ignition retardation attenuation amount is determined. In step ST4, the ignition delay attenuation amount is set to be larger than that in step ST3 (the return speed toward the basic ignition delay amount is increased). Specifically, after the ignition with the effective ignition delay amount is executed five times, the ignition timing is directed to the basic ignition delay amount by 5 ° (CA) for each ignition (for example, toward the advance side). It is set to go back. These values are not limited to this.

  The fuel injection is resumed (fuel injection is resumed) while the ignition control of the spark plug 2 is performed according to the effective ignition delay amount and ignition delay attenuation amount thus obtained.

  FIG. 10 shows the fuel cut execution flag, the ignition timing, and the ignition timing when the ignition delay amount and the ignition delay attenuation amount are set according to the gear ratio of the transmission 14 at the time of return from the fuel cut operation as in this embodiment. 4 is a timing chart showing changes in engine torque and vehicle front-rear G. A broken line in the figure indicates a change when the transmission gear ratio of the transmission 14 is larger than the predetermined transmission gear ratio, that is, when the effective ignition retardation amount is set large and the ignition retardation attenuation amount is set small (step in the flowchart above). The change in the effective ignition delay amount and the ignition delay attenuation amount set in ST3) is shown. Further, the solid line in the figure represents a change when the transmission gear ratio of the transmission 14 is smaller than the predetermined transmission gear ratio, that is, when the effective ignition retardation amount is set small and the ignition retardation attenuation amount is set large (the above flowchart). The change in the effective ignition delay amount and the ignition delay attenuation amount set in step ST4).

  As can be seen from FIG. 10, an appropriate value corresponding to the gear ratio is obtained as a change in the vehicle front-rear G that greatly affects drivability, and the drive torque after the fuel injection returns suddenly increases or increases. It is possible to avoid being sluggish.

-Other embodiments-
In each of the embodiments described above, the belt type CVT is applied as the transmission 14. The present invention is not limited to this, and can also be applied to a toroidal type CVT or a vehicle equipped with a stepped transmission.

  In the first embodiment, the first retard amount calculation map is selected when the auxiliary devices are turned on, and the second retard amount calculation map is selected when the auxiliary devices are turned off. Was selected. That is, two retard angle calculation maps are switched and selected as a map used for calculating the effective ignition retard amount. The present invention is not limited to this, and three or more types of retardation amount calculation maps are prepared according to the number of auxiliary machines in the ON state and the number of auxiliary machines in the OFF state among a plurality of auxiliary machines. In addition, an ignition retardation correction amount may be obtained by selecting one retardation amount calculation map from these retardation amount calculation maps.

  Similarly, in the second embodiment, when the transmission ratio of the transmission 14 is larger than the predetermined transmission ratio, the first retardation amount calculation map is selected, and the transmission ratio of the transmission 14 is smaller than the predetermined transmission ratio. In some cases, the second retardation amount calculation map was selected. That is, two retard angle calculation maps are switched and selected as a map used for calculating the effective ignition retard amount. The present invention is not limited to this, and three or more types of retardation amount calculation maps are prepared according to the transmission ratio of the transmission 14 that changes in a plurality of steps or continuously, and one delay amount is calculated from these retardation amount calculation maps. An ignition amount correction map may be obtained by selecting an angular amount calculation map.

It is a figure which shows the structure of the power transmission system of the vehicle with a clutch mechanism which concerns on embodiment. It is a figure which shows schematic structure of the engine which concerns on embodiment, and its intake / exhaust system. It is a block diagram which shows the control system of an engine and a transmission. It is a figure which shows a basic ignition retard amount determination map. It is a figure which shows a 1st retard amount calculation map. It is a figure which shows a 2nd retard amount calculation map. It is a flowchart figure which shows the procedure of the ignition retard amount calculation operation | movement in 1st Embodiment. FIG. 6 is a timing chart showing changes in a fuel cut execution flag, ignition timing, engine torque, and vehicle longitudinal G in the first embodiment. It is a flowchart figure which shows the procedure of the ignition retard amount calculation operation | movement in 2nd Embodiment. It is a timing chart figure showing change of a fuel cut execution flag, ignition timing, engine torque, and vehicles back and forth G in a 2nd embodiment.

Explanation of symbols

2 Spark plug 3e Injector 10 Engine 12 Lock-up clutch mechanism (clutch mechanism)
14 Belt type CVT (transmission)
17 Drive wheel 21 A / C compressor (auxiliary machine)
23 Generator, alternator (auxiliary machine)

Claims (5)

A clutch mechanism for cutting / engaging between the engine and the transmission is provided. When a predetermined fuel cut condition is established, the clutch mechanism is engaged and the engine is cut, while a predetermined fuel injection return condition is satisfied. In a control device for a vehicle with a clutch mechanism that, when established, restarts fuel injection of the engine,
The physical quantity related to the output torque to the drive wheel after the fuel injection return is used as a parameter, and the more the physical quantity during the fuel cut execution increases the output torque after the fuel injection return, the more A control device for a vehicle with a clutch mechanism, comprising ignition timing correction means for setting a large ignition delay amount. In the control device for a vehicle with a clutch mechanism according to claim 1,
The physical quantity related to the output torque to the drive wheel is the amount of intake air during engine fuel cut,
The control device for a vehicle with a clutch mechanism, wherein the ignition timing correction means is configured to set the ignition retard amount larger as the intake air amount during the fuel cut is larger. In the control device for a vehicle with a clutch mechanism according to claim 1 or 2,
The physical quantity related to the output torque to the drive wheel is a transmission gear ratio during execution of fuel cut of the engine,
The control device for a vehicle with a clutch mechanism, wherein the ignition timing correction means is configured to set the ignition retardation amount to be larger as the transmission gear ratio during the fuel cut is larger. In the control device for a vehicle with a clutch mechanism according to claim 1, 2, or 3,
The ignition timing correction means is configured to correct the ignition delay amount to be smaller as the engine speed is higher than the ignition delay amount set using the physical quantity as a parameter. A control device for a vehicle with a clutch mechanism. In the control device for a vehicle with a clutch mechanism according to any one of claims 1 to 4,
The ignition timing correction means is a return amount per unit period for returning the ignition delay amount after fuel injection return to the original ignition delay amount as the ignition delay amount at fuel injection return is set larger. A control device for a vehicle with a clutch mechanism, characterized in that a certain ignition retardation attenuation amount is set to be small.

Images