JP2015120470A - Controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a vehicle from moving back on an uphill slope and to improve restartability of the vehicle by exhibiting creep power which is suitably large on the uphill slope on the assumption that the number of passengers and the loading weight increase or decrease.SOLUTION: On sensing that a vehicle on an uphill slope moves back without braking by a brake device, the engine rotating speed is increased until the backward movement of the vehicle is not sensed, and the increment is stored as a learning value. When the vehicle is on an uphill slope again thereafter and no braking is performed by the brake device, the engine rotating speed is increased by using the stored learning value of the increment.

Description

  The present invention relates to a control device that increases the engine speed and increases the creep force when a vehicle is on an uphill road.

  When the vehicle is on an uphill road and braking is not performed by the brake device, the engine speed is increased according to the magnitude of the ascending slope of the road surface and transmitted to the drive wheels (axle). It is known to adjust the magnitude of the creep force to prevent the vehicle from sliding down (see, for example, the following patent document).

Japanese Utility Model Laid-Open No. 04-0117139

  In the conventional control, the ascending slope of the road surface and the raised amount of the engine speed correspond to each other on a one-to-one basis. That is, when the creep force is increased on the uphill road, the current number of passengers and the size of the loaded load are not taken into consideration. Actually, every time the vehicle is operated, the number of passengers and the loading load increase and decrease, and the weight of the vehicle fluctuates accordingly, and the optimum creep force level that prevents the vehicle from sliding down on the uphill road also changes. .

  Nevertheless, because the amount of increase in the engine speed on the uphill road is set on the assumption of a predetermined number of passengers or loading load, if only fewer people or loads are mounted, The possibility that the creeping force becomes excessive and the vehicle jumps forward at the moment when the driver removes his foot from the brake pedal cannot be denied. On the other hand, when more people or loads than assumed are mounted, there is a concern that the vehicle may slide backward on the uphill road due to insufficient creep force.

  The present invention, which was made by paying attention to the above problems for the first time, exhibits an appropriate amount of creep force on an uphill road on the premise that the number of passengers and mounted load increase or decrease, prevents the vehicle from sliding down, In addition, the intended purpose is to improve the vehicle's recurrence.

  The present invention controls a vehicle in which an internal combustion engine and drive wheels are connected via a torque converter, and the vehicle is located on an uphill road and braking is not performed by a brake device. When it is detected that the vehicle has moved backward, the engine speed is increased until the vehicle is no longer detected, and the increased amount is stored as a learned value, or the vehicle is moved after the vehicle has been detected to move backward. The amount of increase in engine speed, the amount by which the accelerator pedal is depressed, or the amount by which the intake throttle valve (typically, the throttle valve) is increased is stored as a learned value until no reverse is detected. After that, when a situation occurs where the vehicle is again on the uphill road and braking by the brake device is not performed, the engine speed is increased using the previously stored learning value. To constitute a control unit for the expansion of opening of Gematawa intake throttle valve.

  According to the present invention, even when the number of passengers and the loading load increase or decrease, an appropriate amount of creep force can be exerted on an uphill road, and the vehicle can be prevented from falling down and the vehicle can be restarted. Is possible.

The figure which shows the structure of the internal combustion engine and control apparatus in one Embodiment of this invention. The figure which shows the structure of the drive system in the embodiment.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of an internal combustion engine for a vehicle in the present embodiment. This internal combustion engine is a spark ignition type four-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 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 as an intake throttle valve, 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.

  A brake booster 5 is attached to the vehicle of this embodiment. The brake booster 5 introduces intake negative pressure from a portion of the intake passage 3 downstream of the throttle valve 32, more specifically, from the surge tank 33, and uses this negative pressure to boost the pedaling force of the brake pedal. It is widely known in the field. The brake booster 5 has a constant pressure chamber for storing negative pressure and a variable pressure chamber for applying atmospheric pressure, and the constant pressure chamber is connected to the surge tank 33 via the negative pressure line 51. The negative pressure line 51 guides the intake negative pressure downstream of the throttle valve 32 to the constant pressure chamber. A check valve 52 is provided on the negative pressure line 51 to keep the negative pressure in the constant pressure chamber and prevent the positive pressure from being applied to the constant pressure chamber.

  When the brake pedal is not operated by the driver, the constant pressure chamber and the variable pressure chamber communicate with each other, and the variable pressure chamber is isolated from the atmospheric pressure. When the brake pedal is operated, the constant pressure chamber and the variable pressure chamber are interrupted, and the atmosphere is introduced into the variable pressure chamber. As a result, the pressure difference between the constant pressure chamber and the variable pressure chamber becomes a control pressure that boosts the depression force of the brake pedal. The brake pedal force amplified by the brake booster 5 is converted into hydraulic pressure in the master cylinder 6. The hydraulic fluid pressure output from the master cylinder 6 is transmitted to a brake device (not shown) such as a brake caliper or a wheel cylinder via a hydraulic circuit (not shown), and is used for braking the vehicle by the brake device.

  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 torque 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 driving wheel (not shown) connected to the axle 103 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.

  In a vehicle equipped with CVT 9, when the vehicle speed is a predetermined value (for example, 10 km / h) or more, the torque converter 7 is almost always locked up. When the vehicle speed is equal to or lower than the predetermined value, 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. The engine torque input to the input side (drive plate) of the torque converter 7 at the time of lock-up is output from the torque converter cover 74 via the lock-up clutch 73 and thus to the forward / reverse switching device 8. Communicated directly to. 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.

  In turn, the lock-up clutch 73 is separated from the torque converter cover 74 at the time of non-lock-up. 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 turn, 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.

  In the N range and P range, which are non-traveling ranges, both the forward brake 84 and the reverse clutch 85 are disconnected.

  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.

  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 and engine speed of the crankshaft, and depression of an accelerator pedal. The accelerator opening signal c output from a sensor that detects the amount or the opening of the throttle valve 32 as an accelerator opening (so-called required load), the intake air temperature and the intake pressure in the intake passage 3 (particularly, the surge tank 33). The intake air temperature / intake pressure signal d output from the temperature / pressure sensor to be detected, the coolant temperature signal e output from the water temperature sensor to detect the coolant temperature of the internal combustion engine, whether the brake pedal is depressed or not Brake switch or stepping amount signal f output from a sensor that detects the amount of depression, applied to the brake pedal A master cylinder pressure signal g output from a sensor for detecting a master cylinder pressure, which is a fluid pressure obtained by converting a force in the master cylinder 6; An inclination angle (or acceleration) signal h output from the acceleration sensor) is input.

  From the output interface, an ignition signal i is output to the igniter of the spark plug 12, a fuel injection signal j is output to the injector 11, an opening operation signal k is output to the throttle valve 32, and the like.

  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 intake volume. Then, operating parameters such as required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, and the like are determined. The ECU 0 applies various control signals i, j, k corresponding to the operation parameters via the output interface.

  When the driver is stepping on the accelerator pedal, the ECU 0 operates the opening of the throttle valve 32 in accordance with the amount of depression of the accelerator pedal, and the amount of intake air and fuel injected into the cylinder 1 and thus the engine speed. The engine torque is adjusted to a magnitude corresponding to the required load.

  On the other hand, when the driver is not operating the accelerator pedal, the opening of the throttle valve 32 is operated in accordance with the deviation between the current engine speed and the target idle speed, and the intake air amount and fuel charged in the cylinder 1 are controlled. The injection amount is adjusted so as to reduce the deviation. That is, feedback control of the idle speed is performed.

  Further, the ECU 0 of the present embodiment senses that the vehicle is currently located on an uphill road through an inclination angle sensor (acceleration sensor) and is not braked by a brake device, that is, a driver. When the brake pedal is not operated (the brake switch is OFF, or the amount of depression of the brake pedal or the master cylinder pressure is 0 or a threshold value close to 0), the target idle speed is Set higher than when you are on a flat or downhill road. As a result, the engine torque output from the internal combustion engine is increased, and the creep force transmitted to the drive wheels is increased.

  It is preferable that the basic value of the target idle speed when the vehicle is located on an uphill road and braking by the brake device is not performed is variable in accordance with the magnitude of the ascending slope of the road surface at that time. Specifically, the basic value of the target idle speed is set higher as the ascending slope of the road surface is larger.

  In addition, when the ECU 0 of the present embodiment senses that the vehicle has slipped rearward on the uphill road through the vehicle speed sensor, the ECU 0 raises the target idle speed until it does not sense the vehicle slipping down. Then, the amount of increase when the vehicle is no longer perceived is stored in the memory as a learning value together with the magnitude of the upward slope of the road surface at that time.

  The learned value of the target idle speed increase amount stored in the memory is used to determine the target engine speed when a situation occurs in which the vehicle is located again on the uphill road and braking by the brake device does not occur. When a past learning value corresponding to the magnitude of the current road slope is stored in the memory, the ECU 0 reads the learning value from the memory.

  Then, the target idle speed is increased by using this learning value. As a result, the target idle speed is increased from the memory to a basic value higher than the target idle speed on a flat road or a downhill road (as described above, this basic value is also higher as the ascending slope of the road surface is larger). The read learning value (lifting amount) is taken into account. By raising the target idle speed in advance at the moment when the driver removes his / her foot from the brake pedal on the uphill road, it is possible to prevent the vehicle from sliding backward.

  In addition, when executing the increase of the target engine speed on the uphill road, the past learning value corresponding to the magnitude of the uphill slope of the current road surface is not stored in the memory, in other words, the learning for the uphill slope is completed. If not, the learned value for the upslope that has already been learned is read from the memory, and this learned value is converted into a raised amount corresponding to the current upslope, and the target engine speed Used to determine

  Assuming that the gradient of the road surface on which learning has been completed is θ and the gradient of the current road surface on which learning has not been completed is θ ′, the force F for moving the vehicle backward on the road surface of the gradient θ and the gradient θ ′ The relationship F ′ / F = sin θ ′ / sin θ is established with the force F ′ that attempts to move the vehicle backward on the road surface. In order to prevent the vehicle from sliding down on the road surface having the gradient θ ′, it is assumed that an engine torque that is (sin θ ′ / sin θ) times the engine torque at which the vehicle does not slide down on the road surface having the gradient θ is required. . Therefore, in order to realize such an engine torque, the amount of increase in the target engine speed corresponding to the gradient θ ′ may be estimated from the learning value corresponding to the gradient θ, the gradient θ, and the gradient θ ′.

  Learning and updating the target engine speed increase amount is performed at least once during one trip. The trip means a period from when the ignition switch is turned ON to start the internal combustion engine to when the ignition switch is turned OFF to stop the internal combustion engine. Also, the learned value learned during a trip is erased from the memory after the trip ends and is not carried over to the next trip. This is because it is not guaranteed that the number of passengers or the load on the vehicle on the current trip is equal to the number of passengers or the load on the next trip.

  It goes without saying that the learning and updating of the target engine speed increase amount may be executed each time the vehicle reaches the uphill road. This is because the weight of the vehicle may change during a trip due to a person getting off on the way or a new load of luggage.

  In the present embodiment, a vehicle in which an internal combustion engine and drive wheels are connected via a torque converter 7 is controlled, and the vehicle is located on an uphill road and is not braked by a brake device. Sometimes, when it senses that the vehicle has moved backward, it increases the engine speed until it senses that the vehicle is moving backward, and stores the increased amount as a learned value, after which the vehicle is located on the uphill road again. In addition, when a situation occurs in which braking by the brake device is not performed, the control device 0 is configured to increase the engine speed using the learned value of the increase amount stored previously.

  According to this embodiment, even if the number of passengers and the load on board increase or decrease, an appropriate amount of creep force can be exerted on an uphill road, and the vehicle can be prevented from falling down and the vehicle can be restarted. It becomes possible. Even if the vehicle slips down once on the uphill road, if the vehicle again approaches the uphill road, the target idle speed is raised using the learned value learned earlier, and the creep force is increased. This prevents the vehicle from slipping down on the uphill road.

  In addition, by performing learning, the amount of increase in the target idle speed is adjusted to a suitable value according to the number of passengers and mounting load at that time. It is no longer necessary to significantly increase the basic value of the target idle speed, which can contribute to prevention of a feeling of popping out of the vehicle and suppression of fuel consumption.

  The present invention is not limited to the embodiment described in detail above. In the above embodiment, when the vehicle is located on an uphill road and braking by the brake device is not performed, when it is detected that the vehicle has moved backward, the engine speed is increased until the vehicle is not detected to move backward. At the same time, the raised amount was stored as a learning value.

  On the other hand, when the vehicle slides down even a little on the uphill road, the driver depresses the accelerator pedal and enlarges the intake throttle valve (throttle valve 32) to increase the engine torque and prevent the vehicle from further sliding down. It is normal. Therefore, the amount of increase in engine speed, the amount of depression of the accelerator pedal, or the amount of increase in the opening of the intake throttle valve from when the ECU 0 senses the reverse of the vehicle until it no longer senses the reverse of the vehicle. This is stored as a learned value, and then when the vehicle is located on the uphill road again and braking by the brake device does not occur, the learned value stored earlier is used to increase the engine speed or It is also conceivable to increase the opening of the throttle valve. In this case, the ECU 0 does not necessarily increase the engine speed for the first vehicle slip on the uphill road.

  In the above embodiment, in the feedback control of the engine speed (to the target idle speed) when the driver is not operating the accelerator pedal, the throttle valve 32 is operated to increase or decrease the intake air amount. However, when an idle speed control valve is mounted in the intake passage 3 of the internal combustion engine, the intake air amount can be increased or decreased by operating the idle speed control valve. As is well known, the idle speed control valve is an intake throttle valve (flow control valve) that opens and closes a bypass communicating the upstream side and the downstream side of the throttle valve 32 in the intake passage 3.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to control of an internal combustion engine mounted on a vehicle.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 1 ... Cylinder 11 ... Injector 3 ... Intake passage 32 ... Intake throttle valve (throttle valve)
7 ... Torque converter 103 ... Axle

Claims (1)

Controlling a vehicle in which an internal combustion engine and drive wheels are connected via a torque converter,
When the vehicle is located on an uphill road and braking by the brake device is not performed, if it is detected that the vehicle has moved backward, the engine speed is increased and the amount of increase is increased until the vehicle is not detected to move backward. Is stored as a learning value, or the amount of increase in engine speed, the amount of accelerator pedal depression, or the intake throttle valve from when the reverse of the vehicle is sensed until no reverse of the vehicle is sensed. The amount of expansion of the opening of is memorized as a learning value,
After that, when a situation occurs where the vehicle is again on the uphill road and braking is not performed by the brake device, the learning value stored earlier is used to increase the engine speed or increase the opening of the intake throttle valve. Control device to perform.

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