JP6292781B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control device for controlling a vehicle including an internal combustion engine and an automatic transmission, and relates to a vehicle control device that performs idle stop control when a predetermined idle stop condition is satisfied.

  2. Description of the Related Art Conventionally, an idling stop system that improves fuel efficiency by stopping idle rotation of an internal combustion engine when a vehicle is temporarily stopped, such as waiting for a signal, is well known. In the idling stop system, the internal combustion engine is automatically activated when various conditions such as the vehicle speed is lower than the predetermined vehicle speed, the brake operation amount is higher than the predetermined operation amount, the cooling water temperature and the battery voltage are sufficiently high, that is, the idle stop condition is satisfied. It is made to stop (for example, refer patent document 1).

  Here, when a start acceleration request is made during idle stop, the internal combustion engine is restarted and a clutch between the crankshaft and the axle of the internal combustion engine is engaged. Here, in order to start the vehicle promptly, it is desirable to engage the clutch at an early timing.

  However, if the clutch is engaged when the rotational speed on the input side and the rotational speed on the output side of the clutch are greatly different, a problem occurs that a shock occurs when the clutch is engaged and drivability deteriorates.

JP 2012-26394 A

  The present invention pays attention to the above points, and an object of the present invention is to reduce a shock at the time of clutch engagement when a start acceleration request is made during an idle stop.

In order to solve the above problems, a vehicle control apparatus according to the present invention has a configuration as described below. That is, the vehicle control device according to the present invention is a control device that controls a vehicle that includes an internal combustion engine and an automatic transmission and that includes a three-way catalyst for purifying exhaust in an exhaust passage, and fuel cut is started. A clutch between the crankshaft and the axle of the internal combustion engine, which performs idle stop control when a predetermined idle stop condition is satisfied after oxygen is adsorbed on the three-way catalyst and there is a start acceleration request during the idle stop. Is engaged and the ignition cut control is performed while the fuel injection is performed when the output speed of the clutch is below a predetermined value.

  If this is the case, the ignition cut control is performed when the rotational speed on the output side of the clutch is below a predetermined value, thereby suppressing an increase in the rotational speed of the internal combustion engine and hence on the input side of the clutch. Thus, the difference in rotational speed from the output side can be reduced. Therefore, the shock when the clutch is engaged can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the shock at the time of fastening of a clutch when there exists a start acceleration request | requirement during idle stop can be made small.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows the whole structure of the internal combustion engine for vehicles in 1st embodiment of this invention. Schematic which shows the structure of the drive system in the embodiment. The flowchart which shows the example of a procedure of the process which the control apparatus of the embodiment performs. The time chart which shows roughly the effect | action by the control which concerns on the same embodiment.

  An embodiment of the present invention will be described below with reference to the drawings.

  The internal combustion engine in the present embodiment is a spark ignition type 4-stroke gasoline engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode. The ignition coil is integrally incorporated in a coil case together with an igniter that is a semiconductor switching element.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  FIG. 2 shows an example of a drive system provided in the vehicle. This drive system includes a torque converter 7 and automatic transmissions 8 and 9. In particular, in the present embodiment, a forward / reverse switching device 8 using a planetary gear mechanism and a belt-type CVT (Continuously Variable Transmission) 9 which is a type of continuously variable transmission are adopted as components of the automatic transmissions 8 and 9. doing.

  The rotational driving force output from the internal combustion engine is input from the crankshaft of the internal combustion engine to the pump impeller 71 on the input side of the torque converter 7 and transmitted to the turbine runner 72 on the output side. The rotation of the turbine runner 72 is transmitted to the drive shaft 94 of the CVT 9 via the forward / reverse switching device 8 and rotates the driven shaft 95 through a shift in the CVT 9. The rotation of the driven shaft 95 is transmitted to the output gear 101. The output gear 101 meshes with the ring gear 102 of the differential device, and rotates the axle 103 and the drive wheels (not shown) via the differential device.

  The torque converter 7 includes a lockup mechanism. The lock-up mechanism is known in this field, and a lock-up clutch 73 that fastens the input side and the output side of the torque converter 7 so as not to rotate relative to each other, and an operation for switching the connection of the lock-up clutch 73. A lock-up solenoid valve (not shown) for controlling the hydraulic pressure (hydraulic pressure) is used as an element. The lockup solenoid valve is a flow rate control valve that receives a control signal l and changes its opening.

  In principle, the torque converter 7 is almost always locked up under conditions where the vehicle speed is higher than a certain level, for example, at 10 km / h or higher. When the vehicle speed becomes lower than 10 km / h, the lockup of the torque converter 7 is released.

During lockup, the lockup clutch 73 is pressed against the torque converter cover 74 and rotates together with the torque converter cover 74. During lock-up, the engine torque input to the drive plate on the input side of the torque converter 7 is directly transmitted from the torque converter cover 74 to the forward / reverse switching device 8 on the output side of the torque converter 7 via the lock-up clutch 73. Communicated. At the time of lockup, the speed ratio, which is the ratio of the output side rotational speed of the torque converter 7 to the input side rotational speed, is 1.

  When the lockup is not performed, the lockup clutch 73 is separated from the torque converter cover 74. At the time of non-lock-up, the engine torque input to the input side of the torque converter 7 is transmitted from the torque converter cover 74 to the pump impeller 71 and the turbine 72 and is transmitted to the forward / reverse switching device 8. At the time of non-lock-up, the speed ratio of the torque converter 7 becomes smaller or larger than 1 depending on the driving state.

  In the forward / reverse switching device 8, the sun gear 81 communicates with the turbine runner 72, and the ring gear 82 communicates with the drive shaft 94. Between the planetary carrier 83 that supports the planetary gear 831 and the transmission case, a forward brake 84 that is a hydraulic clutch that can be connected and disconnected is interposed. Further, a reverse clutch 85, which is a hydraulic clutch capable of switching connection / disconnection, is also interposed between the planetary carrier 83 and the sun gear 81 (or the output side of the torque converter 7).

  In the D range of the traveling range, the forward brake 84 is engaged and the reverse clutch 85 is disconnected. As a result, the rotation of the output shaft of the torque converter 7 is reversed and decelerated and transmitted to the drive shaft 94 for forward travel. In the R range, the reverse clutch 85 is engaged and the forward brake 84 is disconnected. As a result, the sun gear 81 and the planetary carrier 83 rotate integrally, and the output shaft of the torque converter 7 and the drive shaft 94 are directly connected to perform reverse travel. A solenoid valve (not shown) that controls the hydraulic pressure for driving the forward brake 84 or the reverse clutch 85 to connect / disconnect is a flow rate control valve that receives a control signal m and changes its opening.

  In the N range and P range, which are non-traveling ranges, both the forward brake 84 and the reverse clutch 85 are disconnected. In short, the forward / reverse switching device 8 serves as a clutch for connecting between the internal combustion engine and the axle 103 and for disconnecting between the internal combustion engine and the axle 103.

  The CVT 9 includes a driving pulley 91 and a driven pulley 92, and a belt 93 wound around the pulleys 91 and 92 as elements. The drive pulley 91 is disposed behind the movable sheave 912, a fixed sheave 911 fixed to the drive shaft 94, a movable sheave 912 supported on the drive shaft 91 via a roller spline so as to be displaceable in the axial direction. A hydraulic servo 913 is provided, and the gear ratio can be changed steplessly by operating the hydraulic servo 913 and displacing the movable sheave 912. The driven pulley 92 is disposed on the back of the movable sheave 922, a fixed sheave 921 fixed to the driven shaft 95, a movable sheave 922 supported on the driven shaft 95 via a roller spline so as to be axially displaceable. A hydraulic servo 923 is provided, and a belt thrust necessary for torque transmission is applied by operating the hydraulic servo 923 and displacing the movable sheave 922.

  A hydraulic pump (hydraulic fluid) supplied to the forward brake 84 or the reverse clutch 85 to operate the travel range, and a hydraulic pump (discharge fluid) supplied to the hydraulic servos 913 and 923 to operate the gear ratio. (Not shown) is of a known mechanical type (non-electric type) that operates by receiving the rotational driving force from the crankshaft of the internal combustion engine. This hydraulic fluid is common to the fluid used for the torque converter 7.

  An ECU (Electronic Control Unit) 0 that is a control device of the present embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that detects the rotation angle of the crankshaft and the engine speed, and the accelerator pedal. An accelerator opening signal c output from a sensor that detects the amount of depression or the opening of the throttle valve 32 as an accelerator opening (in other words, a required load), a brake that is output from a sensor that detects the hydraulic pressure in the master cylinder of the brake booster Stepping amount signal d, intake air temperature / intake pressure signal e output from a temperature / pressure sensor for detecting intake air temperature and intake pressure in intake passage 3 (especially surge tank 33), water temperature sensor for detecting engine cooling water temperature Sensor (or shift position) to know the coolant temperature signal f output from the shift lever range A shift range signal g output from the switch), a rotational speed signal h output from a rotational speed sensor for detecting the rotational speed on the input side of the CVT 9 in order to know the rotational speed Nc on the output side of the forward / reverse switching device 8 and the like. Is entered.

  From the output interface, the ignition signal i for the igniter of the spark plug 12, the fuel injection signal j for the injector 11, the opening operation signal k for the throttle valve 32, and the connection / disconnection of the lockup clutch of the lockup mechanism The opening degree control signal l for the lockup solenoid valve for switching, the opening degree control signal m for the solenoid valve for connection / disconnection switching of the forward brake 84 or the reverse clutch 85, the transmission ratio control signal n for the CVT 9, etc. Etc. are output.

  The processor of the ECU 0 interprets and executes a program stored in the memory in advance, calculates operation parameters, and controls the operation of the internal combustion engine. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine via the input interface, knows the engine speed, and is filled in the cylinder 1. Estimate the amount of intake air. Based on the engine speed, the intake air amount, etc., the required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, and torque converter 7 lock-up are controlled. Various operation parameters such as whether or not to perform are determined. As the operation parameter determination method itself, a known method can be adopted. The ECU 0 applies various control signals i, j, k, l, m, and n corresponding to the operation parameters via the output interface.

Further, the ECU 0 stops fuel injection from the injector 11 (and spark ignition by the spark plug 12) at the time of a deceleration request to the vehicle, and executes a fuel cut that interrupts the fuel supply to the cylinder 1. The ECU 0 determines that the fuel consumption is at least as long as the rotational speed Ne of the internal combustion engine exceeds a predetermined rotational speed, that is, a predetermined fuel cut permission rotational speed Ne ₁ , and the accelerator pedal depression amount is below a predetermined threshold value that is close to zero. It is determined that the cutting condition is satisfied.

  If a predetermined fuel cut end condition is satisfied during the fuel cut, the fuel cut is ended and fuel injection (and ignition) is restarted. The ECU 0 determines that the fuel cut end condition is satisfied, for example, when the accelerator pedal depression amount exceeds a threshold value or the engine speed decreases to the lower limit speed (fuel cut return speed). To do.

  In addition, the ECU 0 of the present embodiment executes an idle stop that stops the idle rotation of the internal combustion engine when the vehicle stops due to a signal waiting or the like. The ECU 0 has various conditions such that the vehicle speed is a predetermined vehicle speed, for example, 10 km / h or less, the brake operation amount exceeds the predetermined operation amount, the cooling water temperature and the battery voltage are sufficiently high, and the brake booster negative pressure is sufficiently ensured. It is determined that the idle stop condition has been established by the fact that it has been established.

  When a predetermined idle stop end condition is satisfied after the idle stop condition is satisfied, the internal combustion engine is restarted. The ECU 0 establishes the idle stop termination condition when the brake pedal is released, the accelerator pedal is depressed, a predetermined time (for example, 3 minutes) has elapsed in the idle stop state, or the like. Judge that it was done.

  When the driver removes his or her foot from the accelerator pedal while the vehicle is running and the vehicle decelerates and stops, first the fuel cut condition is satisfied and the fuel cut is started, and then the idle stop condition is satisfied and the engine is idle. Transition to the stop.

Therefore, in this embodiment, there is a start acceleration request during idle stop, more specifically, an accelerator pedal depression operation for starting or accelerating the vehicle, a clutch between the crankshaft and the axle of the internal combustion engine, Specifically, the ignition for performing the ignition cut control when the forward brake 84 of the forward / reverse switching device 8 is engaged and the rotational speed Nc on the output side of the clutch is lower than the predetermined rotational speed Nc _1. Built-in control program. This ignition control program is executed at a predetermined time, for example, every 0.1 second after the idle stop condition is established. More specifically, when the idle stop termination condition is satisfied, the internal combustion engine is restarted. When the shift lever is in the D range, the forward brake 84 of the forward / reverse switching device 8 is engaged. Before the internal combustion engine is started, that is, before the engine speed Ne exceeds the idle speed Ne ₀ , the forward brake 84 of the forward / reverse switching device 8 is engaged and the rotational speed Nc on the output side of the automatic transmission 8 is if below a predetermined value Nc _1, in order close to the pre-rotation speed of the output side, that the axle side to reduce the rotational speed of the input side or engine side of the reverse switching device 8, performs the ignition cut control.

  Hereinafter, a control procedure performed by the processor executing this ignition control program will be described below with reference to FIG. 3 which is a flowchart.

It is detected that a start acceleration request is made during idle stop (step S1), the forward brake 84 of the forward / reverse switching device 8 is engaged (step S2), and the output side of the forward / reverse switching device 8 If the rotational speed Nc of meets the condition that is below a predetermined rotational speed Nc ₁ (step S3), and performs the ignition cut control (step S4). In other cases, the ignition cut control is not performed. In the present embodiment, ignition by the spark plug 12 is stopped by the ignition cut control, but fuel injection by the injector 11 is performed as usual. Further, in the present embodiment, ignition is stopped for each cylinder for one ignition timing.

That is, during the idling stop, as shown in FIG. 4, after the start acceleration request is made (time t ₁ ), the engine speed Ne exceeds the idle speed Ne ₀ (time t ₃ ) (in FIG. When the shift lever is in the D range before the determination flag ON ”and the forward brake 84 of the forward / reverse switching device 8 is engaged (time t ₂ ) (indicated as“ clutch engagement determination flag ON ”in FIG. 4). in the rotation speed Nc of the output side of the forward-reverse switching device 8 when below the predetermined rotational speed Nc _1, the ignition-cut control is performed, the increase in the engine rotational speed Ne is suppressed. That is, control is performed to reduce the difference in rotational speed between the input side and the output side of the forward / reverse switching device 8.

As described above, according to this embodiment, by the rotation speed Nc of the output side of the forward-reverse switching device 8 performs the ignition cut control when below the predetermined rotational speed Nc _1, rotation of the internal combustion engine As a result, an increase in the rotational speed on the input side of the forward / reverse switching device 8 can be suppressed, and the difference in rotational speed from the output side can be reduced. Therefore, the shock when the forward brake 84 is engaged can be reduced.

  Further, the ignition plug 12 is stopped by ignition cut control, while the fuel injection by the injector 11 is performed as usual, so that the following effects can be obtained. That is, when a fuel cut is performed prior to the idling stop, air that does not contain fuel is introduced into the three-way catalyst 41 during the fuel cut, and an excessive amount of oxygen is adsorbed by the three-way catalyst 41. After starting, there has been a problem that NOx in the exhaust gas is not reduced and discharged to the outside. In contrast, in this embodiment, unburned fuel is supplied to the three-way catalyst 41 by injecting fuel even at the timing of stopping ignition, and the unburned fuel and oxygen adsorbed by the three-way catalyst 41 are , The oxygen adsorbed on the three-way catalyst 41 is consumed, so that the problem that NOx in the exhaust gas is discharged without being reduced can be solved.

  The present invention is not limited to the embodiment described above.

  For example, in the embodiment described above, when it is detected that a start acceleration request has been made during idle stop, the internal combustion engine is first restarted, and after the cranking is completed, the rotational speed of the internal combustion engine exceeds a predetermined rotational speed. The clutch (forward brake) of the automatic transmission is controlled at the point of time, but the lockup clutch of the torque converter 7 is engaged when the number of revolutions of the internal combustion engine exceeds a predetermined number after cranking is completed. You may make it do.

  Further, in the above-described embodiment, it is assumed that the start acceleration request is made when the accelerator pedal is depressed, but the start acceleration request is made when the operation amount of the brake pedal falls below a predetermined threshold. In addition, it may be determined that the start acceleration request is made when the accelerator pedal is depressed and the operation amount of the brake pedal falls below a predetermined threshold.

  In addition, in the above-described embodiment, the rotational speed on the input side of the CVT is detected so as to know the rotational speed on the output side of the forward / reverse switching device, but the vehicle speed and the transmission ratio of the CVT are used as parameters. You may make it know the rotation speed of the output side of a decimal switching device.

  Furthermore, in the above-described embodiment, ignition is stopped only for one ignition timing for each cylinder, but the number of times of stopping ignition may be arbitrarily set.

  In the embodiment described above, the present invention is applied to a vehicle equipped with an automatic transmission equipped with a forward / reverse switching device and a CVT. However, the present invention is applied to a vehicle equipped with an automatic transmission formed by combining a plurality of gears. Of course, the present invention may be applied.

  In addition, various changes may be made without departing from the spirit of the present invention.

0 ... Control device (CVT)
8, 9 ... Automatic transmission 84 ... Clutch (forward brake)
103 ... Axle

Claims (1)

A control device for controlling a vehicle having an internal combustion engine and an automatic transmission and having a three-way catalyst for exhaust purification in an exhaust passage ,
When a predetermined idle stop condition is satisfied after fuel cut is started and oxygen is adsorbed on the three-way catalyst , idle stop control is performed,
Ignition cut control when there is a start acceleration request during idle stop, the clutch between the crankshaft and the axle of the internal combustion engine is engaged, and the output speed of the clutch is below a predetermined value And a control device for a vehicle, wherein the control is performed such that fuel injection is performed.

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