JP2014040794A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine that enables rapid and even restarting by accurately controlling the stop position of a piston while suppressing fuel consumption.SOLUTION: A control device ECUo of an internal combustion engine 100 detects a crank shaft 10 just before stop on the basis of a vehicle speed signal a to be vehicle speed information, a crank angle signal b to be rotation speed information and a brake stepping quantity signal d to be brake information. When a differential value between an estimation stop position and a target stop position of a piston 13 at stopping is equal to and larger than a predetermined value in detecting the crank shaft just before stop, the control device controls a motor generator 10 on a torque increase side by a predetermined amount before the piston 13 stops, and stops the piston 13 to the target stop position.

Description

  The present invention relates to a control device for an internal combustion engine mounted on a vehicle on which a motor generator having a starter function and a power generation function is mounted.

  2. Description of the Related Art Conventionally, various technologies for controlling a piston to stop at a desired position have been proposed in order to realize a quick and uniform restart, particularly in a vehicle that performs idle stop (for example, Patent Document 1). reference). The one described in Patent Document 1 estimates the position to stop by inertial rotation from the rotational speed just before stopping and the position of the piston, and if it is predicted to stop at a position different from the desired position, torque is generated by combustion. Is generated to control the stop position of the piston.

  However, in the case of performing the control for generating the torque due to the combustion as in the above-mentioned Patent Document 1, the control cannot be performed unless the rotation speed above a certain level is maintained. Moreover, considering that the piston stop depends on the inertial rotation of the crankshaft after the fuel cut, the stop position must be controlled from a state in which the rotation speed exceeds a certain level, resulting in variations in control results. It was easy to occur. Further, the generation of torque due to combustion includes the problem of increasing combustion consumption.

Special table 2003-518585 gazette

  The present invention pays attention to such a problem, and provides an internal combustion engine control device capable of realizing quick and uniform restart by accurately controlling the stop position of a piston while suppressing fuel consumption. It is an object.

  In order to achieve such an object, the present invention takes the following measures.

  That is, the control device for an internal combustion engine according to the present invention detects immediately before stopping the crankshaft based on the vehicle speed information, the rotation speed information, and the brake information, and detects the immediately before stop when the estimated stop position of the piston at the time of stopping is detected. When the difference value from the target stop position is a certain value or more, the piston is stopped at the target stop position by controlling the motor generator to a torque increasing side by a predetermined amount before the piston stops.

  If this is the case, it is possible to accurately determine the piston stop position without fuel consumption by controlling the motor generator to the torque increasing side immediately before stopping the rotation of the crankshaft, where the piston stop position is easy to predict. Can be controlled. In addition, it is possible to realize control with a smaller torque and rotation of the piston at an earlier timing than rotating the crankshaft that is stopped in order to control the motor generator before the end of the rotation operation of the crankshaft. In addition, since the motor generator is controlled to function in the same direction as the rotation of the crankshaft, that is, as a motor rather than as a generator, the generated torque of the starter generator itself and the power consumption associated with it can be reduced. The stop position of the piston can be accurately controlled while suppressing. Thereby, it is possible to realize a quick and uniform restart while suppressing fuel consumption.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the internal combustion engine which can implement | achieve quick and uniform restart by controlling the stop position of a piston correctly, suppressing fuel consumption can be provided.

1 is a schematic configuration diagram according to an embodiment of the present invention. The schematic block diagram of the internal combustion engine which concerns on the same embodiment. The timing chart which concerns on the same embodiment. The flowchart.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a basic structure of an example of a vehicle drive device in the present embodiment, and FIG. 2 shows an outline of the vehicle internal combustion engine 100.

  A transmission 120 is fixed to one end side of the internal combustion engine 100, and a motor generator 110 is disposed on the side opposite to the transmission 120 with respect to the internal combustion engine 100. An air conditioning compressor 130 is fixed to an outer wall on one side of the internal combustion engine 100 where the motor generator 110 is disposed. In the present embodiment, the starter motor arranged on the transmission 120 side of the internal combustion engine 100 is omitted in the conventional vehicle, and the cranking can be performed by the motor generator 110 being rotated by electric power of a battery (not shown). In the present embodiment, a vehicle using only the internal combustion engine 100 as a drive source is shown as an example, but a hybrid vehicle (HV vehicle) may of course be used.

  The motor generator 110 shown in the figure is of an inner rotor type, for example, and includes a rotor having permanent magnets and a stator having coils so as to face the outer peripheral surface of the rotor, and the rotor is fixed to the outer periphery of the rotor shaft 112. The usual configuration is made. A motor clutch 111 is provided between one end side of the rotor shaft 112 and the crankshaft 10.

  A pulley 113 is fixed to a shaft end portion protruding to the other end side of the rotor shaft 112. A belt 114 is wound around the pulley 113, and the belt 114 is also wound around a pulley 133 fixed to the output shaft 132 of the air conditioning compressor 130, for example. The air conditioning compressor 130 is equipped with a magnet clutch 131 as is well known. In the figure, an example in which the pulley 133 is fixed to the tip of the output shaft 132 protruding from the magnet clutch 131 is shown. However, for example, a rotor provided on the outer periphery of the magnet clutch 131 may also serve as the pulley 133. . The belt 17 may be wound around a pulley of an auxiliary machine (such as an oil pump or a water pump) other than the air conditioning compressor 130. As the motor generator 110, various motors such as a magnetless motor and an AC motor may be used.

  As shown in FIG. 2, the internal combustion engine 100 in the present embodiment is a spark ignition gasoline engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 2). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. Further, an ignition plug is provided at the ceiling of the combustion chamber of each cylinder 1 in which a piston 13 connected via a connecting rod 14 to a crankshaft 10 rotatably provided over a plurality of cylinders 1 is reciprocally housed. 12 is attached. 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.

  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 which is vehicle speed information output from a vehicle speed sensor which detects the actual vehicle speed of the vehicle, a crank which is rotation speed information output from an engine rotation sensor which detects the rotation angle of the crankshaft 10 and the engine rotation speed. An angle signal (N signal) b, an accelerator pedal depression amount or a throttle valve 32 opening amount as an accelerator opening amount (so-called required load), an accelerator opening degree signal c output from a sensor, and a brake pedal depression amount Brake pedal amount signal d as brake information output from the sensor to be detected, intake air temperature / intake pressure signal output from the temperature / pressure sensor for detecting the intake air temperature and intake pressure in the intake passage 3 (particularly, the surge tank 33) e, a cooling water temperature signal f output from a water temperature sensor for detecting the cooling water temperature of the engine, an illustration for detecting the voltage of the battery Battery voltage signal g outputted from the no voltmeter, a cam angle signal (G signal) which is output from the cam angle sensor at a plurality of cam angle of the intake camshaft or an exhaust camshaft h the like are input.

  From the output interface, an ignition signal i for the igniter of the spark plug 12, a fuel injection signal j for the injector 11, an opening operation signal k for the throttle valve 32, and the motor generator 110 as a generator or starter motor. An operation signal o for operation is output.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operation parameters, and controls the operation of the internal combustion engine 100. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine 100 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., various 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, and ignition timing are determined. . As the operation parameter determination method itself, a known method can be adopted. Thus, the ECU 0 applies various control signals i, j, k, o corresponding to the operation parameters via the output interface.

  Further, the ECU 0 inputs a control signal o to the motor generator 110 when the internal combustion engine 100 is started (it may be a cold start or a return from an idling stop), and the crankshaft 10 is directly rotated. Perform cranking. Cranking ends from the first explosion to the consecutive explosion, and ends when the engine speed exceeds a threshold determined according to the cooling water temperature or the like (assuming that the explosion has been completed).

  ECU0 of this embodiment can perform what is called an idling stop by functioning as an automatic stop start device in such a configuration. In executing the idling stop, the ECU 0 stores an idling stop program, and an idling stop condition and a restart condition are set in the idling stop program. The idling stop condition is that at least the charge amount of the battery is equal to or higher than the predetermined charge amount, the outside air temperature is equal to or higher than the predetermined temperature, the engine temperature is equal to or higher than the predetermined temperature, and the vehicle speed is a predetermined speed after the previous idle stop. There is a history of traveling as described above, a time after a predetermined start has elapsed since the last start of the internal combustion engine 100, a predetermined stop time has elapsed since the vehicle stopped, The predetermined idle time has elapsed and the brake pedal has been depressed. The idling stop is performed when all of these idling stop conditions are satisfied.

  On the other hand, the restart condition is that at least the operation of the brake pedal (for example, depressing) is stopped, the accelerator pedal is operated (for example, depressing), and a predetermined restart time has elapsed since the start of the idling stop. Etc. The restart is performed when at least one of the restart conditions is satisfied. The idling stop condition and the restart condition described above are not limited to the listed items, and those known in this field may be adopted.

  Therefore, the ECU 0 that is the control device for the internal combustion engine 100 according to the present embodiment immediately before the crankshaft 10 is stopped based on the vehicle speed signal a that is vehicle speed information, the crank angle signal b that is rotation speed information, and the brake pedaling amount signal d that is brake information. When the difference between the estimated stop position of the piston 13 at the stop and the target stop position P is equal to or greater than a predetermined value when detecting just before the stop, the motor generator 110 is torqued before the piston 13 stops. The piston 13 is stopped at the target stop position P by controlling a predetermined amount on the increase side.

  Hereinafter, control for stopping the piston 13 according to the present embodiment at the target stop position P will be described based on the timing chart of FIG. 3 and the flowchart of FIG. 4.

  First, it is detected from the vehicle speed signal “a”, the crank angle signal “b”, and the brake pedaling amount signal “d”, which is brake information, when the fuel is cut, whether or not the vehicle is just before stopping. When a state in which the vehicle speed and the number of revolutions are sufficiently lowered and the brake is depressed is detected, it is detected that the vehicle is just before stopping, and the piston 13 stop position control is permitted (step S1). When the piston stop position control is started (step S2), the stop position of the piston 13 is predicted from the crank angle signal d and the coolant temperature signal f at that time. As an example of a mode for predicting the stop position of the piston 13, the rotational speed obtained from the crank angle signal b, the position of the piston 13, the engine friction related to the rotation of the crankshaft 10 obtained from the coolant temperature, and the prediction of the piston 13 are predicted. A mode in which the correlation with the stop position is stored in advance as a map, and the corresponding stop position is read from the map. Of course, for the prediction of the stop position of the piston 13, the use state of the auxiliary machine including the connection / disconnection state of the magnet clutch 131 may also be referred to.

  If the predicted stop position of the piston 13 is equal to the preset target stop position P or the difference between them is equal to or smaller than a predetermined value (angle), the piston stop position control is terminated as it is, and the piston 13 is moved to the target. Stop at stop position P. On the other hand, if the predicted stop position of the piston 13 is different from the target stop position P or the difference between them is larger than a predetermined value (angle), the motor generator 110 is installed before the rotation of the crankshaft 10 stops. The torque is controlled to be increased for a fixed amount and / or for a predetermined time (step S4). Here, as one of the modes for determining the amount or time for controlling the motor generator 110, the engine related to the rotation speed obtained from the crank angle signal b, the position of the piston 13, and the rotation of the crankshaft 10 obtained from the coolant temperature. The optimal driving amount (electric power) and / or driving time of the motor generator 110 derived from the friction and the difference between the predicted stop position of the piston 13 and the target stop position P are stored in advance as a map. A mode in which the driving amount (power) and / or driving time of the corresponding motor generator 110 is read out can be mentioned. In determining the drive amount (electric power) and / or drive time of the motor generator 110, the use state of the auxiliary machine including the connection / disconnection state of the magnet clutch 131 may be referred to. By doing so, the piston 13 can be accurately stopped at the target stop position P as shown in FIG.

  By doing as described above, the ECU 0 according to the present embodiment controls the motor generator 110 to the torque increasing side immediately before stopping the rotation of the crankshaft 10 in which the stop position of the piston 13 is easy to predict. Without stopping, the stop position of the piston 13 can be accurately controlled. In order to control the motor generator 110 before the end of the rotation operation of the crankshaft 10, the control with a torque smaller than the rotation of the crankshaft 10 stopped and the stop of the piston 13 at an early timing are performed. Realized. In addition, since the motor generator 110 is controlled to function in the same direction as the rotation of the crankshaft 10, that is, function as a motor rather than as a generator, the generated torque of the starter generator itself and the power consumption associated therewith can be reduced, and the fuel efficiency is effective. The stop position of the piston 13 is accurately controlled while keeping the pressure at a low level. As a result, the internal combustion engine 100 can be restarted, including a quick and uniform restart from idle stop, while reducing fuel consumption.

  Although the embodiment of the present invention has been described above, the specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the present invention is disclosed in a port injection type internal combustion engine, but may be applied to a direct injection type internal combustion engine. In that case, the target stop position of the piston may be set to an optimum position for starting without passing through cranking. Moreover, although the aspect which controls a motor generator only in the direction where a torque increases is disclosed in the said embodiment, of course, you may make it perform control which uses together the timing which increases a torque, and the timing which decreases a torque. In addition, specific modes such as the target stop position of the piston, the rotation speed and vehicle speed that are determined to be just before the stop are not limited to those of the above-described embodiment, and those of various modes including the existing ones are applied. can do.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used as a control device for an internal combustion engine in a vehicle equipped with a motor generator having a starter function and a power generation function, particularly in a vehicle that performs idle stop.

0 ... Control device (ECU) for internal combustion engine
DESCRIPTION OF SYMBOLS 100 ... Internal combustion engine 10 ... Crankshaft 13 ... Piston 110 ... Motor generator a ... Vehicle speed information (vehicle speed signal)
b ... Rotational speed information (crank angle signal)
d ... Brake information (Brake pedaling amount signal)
o ... Operation signal

Claims (1)

Based on vehicle speed information, rotation speed information, and brake information,
When the difference between the estimated stop position of the piston and the target stop position at the time of stoppage is equal to or greater than a certain value when detecting just before the stop, the motor generator is controlled by a predetermined amount on the torque increasing side before the piston stops. The control apparatus of the internal combustion engine which stops the piston at the target stop position by means of.

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