JP2018071439A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a restart of an internal combustion engine which has started idle-stopping not meeting the intention of a driver, and to shorten a time necessary for the restart when performing the restart meeting the intention of the driver as much as possible.SOLUTION: In a vehicle, an auxiliary motor which can drive an output shaft of an internal combustion engine is arranged different from a starting motor used for cranking for starting the internal combustion engine, in a case where idle-stopping of the internal combustion engine is started before the vehicle is stopped, the output shaft of the internal combustion engine is driven by the auxiliary motor when a pedal-in amount of a brake pedal reaches zero or a value not larger than a threshold which is approximate to zero, the rotation of the output shaft is maintained for a prescribed period of time, when the pedal-in amount of the accelerator pedal reaches the threshold or larger within the prescribed period of time, cranking for starting the internal combustion engine is performed by using the starting motor, or the drive of the output shaft of the internal combustion engine performed by the auxiliary motor is stopped.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle capable of executing an idle stop of an internal combustion engine.

  It is known to perform an idle stop that stops the idle rotation of the internal combustion engine while the vehicle is stopped due to a signal or the like (for example, refer to the following patent document). In the existing idle stop system, when the vehicle speed is below a predetermined value, the brake pedal is depressed, the cooling water temperature of the internal combustion engine and the voltage of the on-board battery are sufficiently high, etc., the internal combustion engine is Stop. During the idling stop, when there is a restart request such as when the driver removes his foot from the brake pedal or depresses the accelerator pedal, the internal combustion engine is restarted.

  Recently, in order to further improve the fuel efficiency of the vehicle, the vehicle speed condition, which is one of the idle stop conditions, has been raised, and the internal combustion engine is started to idle before the vehicle stops. ing.

  If the driver removes his foot from the brake pedal when starting an idle stop before the vehicle stops, but the intention was to adjust the vehicle's inertia or deceleration rather than re-accelerate the vehicle, If you initially had the intention to re-accelerate but change your mind, or if the driver inadvertently depresses the brake pedal, the conventional system will end idle stop (restart the internal combustion engine). The internal combustion engine was restarted on the assumption that the (start) condition was satisfied. That is, a restart that does not match the driver's intention is performed, and fuel is wasted and noise accompanying cranking of the internal combustion engine occurs.

  Further, when restarting the internal combustion engine, it is necessary to perform a stroke determination for confirming which stroke each cylinder is currently in. A crank angle sensor and a cam angle sensor are attached to the crankshaft and the camshaft of the internal combustion engine, respectively, for obtaining the rotation angle. The crank angle sensor and the cam angle sensor detect that the teeth or protrusions formed on the rotor rotating integrally with the shaft have passed near the pickup coil and output a pulse signal each time.

  When the idle stop is started before the vehicle stops and then the idle stop end condition is satisfied and the internal combustion engine is restarted before the internal combustion engine is completely stopped, the rotation speed of the crankshaft and the camshaft is slow. As a result, the cycle of the pulse signal output from the crank angle sensor or the cam angle sensor becomes longer, and a beautiful pulse with a high S / N ratio cannot be obtained. As a result, there is a possibility that the current rotation angle of the crankshaft and the camshaft is erroneously recognized, and thus it is erroneously determined which stroke each cylinder is currently in. An error in determining the stroke of the cylinder leads to a failure in restarting the internal combustion engine, and the engine cannot be retried until the internal combustion engine is stopped completely. As a result, the restart of the internal combustion engine is delayed.

Japanese Patent Laying-Open No. 2015-121184

  The present invention avoids a restart that does not conform to the intention of the driver of the internal combustion engine that has started the idle stop, and shortens the time required for the restart as much as possible when performing the restart according to the intention of the driver. Is the intended purpose.

  In the present invention, an auxiliary motor capable of driving the output shaft of the internal combustion engine is provided separately from the starting motor used for cranking for starting the internal combustion engine, and before the vehicle stops, When the idling stop is started, when the brake pedal depression amount is 0 or less than a threshold value close to 0, the output shaft of the internal combustion engine is driven by the auxiliary motor to maintain its rotation for a predetermined period. If the accelerator pedal depression amount exceeds a threshold value, cranking is performed for starting the internal combustion engine using the starter motor, otherwise the vehicle that stops driving the output shaft of the internal combustion engine by the auxiliary motor is installed. Configured.

  According to the present invention, it is possible to avoid a restart that does not conform to the driver's intention of the internal combustion engine that has started the idle stop, and to reduce the time required for the restart even when the restart is performed according to the driver's intention. It can be shortened.

The figure which shows schematic structure of the internal combustion engine for vehicles and control apparatus in one Embodiment of this invention. The figure which shows typically the structure of the connection of the internal combustion engine in the same embodiment, a motor, and an alternator. The flowchart which shows the example of the procedure of the process which the control apparatus in the embodiment performs according to a program.

  An embodiment of the present invention will be described with reference to the drawings. A vehicle internal combustion engine 100 shown in FIG. 1 is a spark ignition type four-stroke 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, 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 external EGR (Exhaust Gas Recirculation) device 2 realizes a so-called high-pressure loop EGR. The EGR device 2 includes an external EGR passage 21 that communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, an EGR cooler 22 provided on the EGR passage 21, and an EGR passage 21. And an EGR valve 23 that controls the flow rate of the EGR gas flowing through the EGR passage 21. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33.

  As shown in FIG. 2, the internal combustion engine 100 according to the present embodiment drives a starter motor (cell motor) 140 as a starter motor and a crankshaft 10 that is an output shaft of the internal combustion engine 100 separately from the starter motor 140. An auxiliary motor 130 that can be used and an alternator 110 that is a generator are attached.

  The starter motor 140 is an electric motor dedicated to cranking that rotates the crankshaft 10 of the internal combustion engine 100 mainly during cold start (the driver operates the ignition switch (start switch) or the ignition key to start the internal combustion engine 100). It is. The starter motor 140 has a pinion gear 141 on its output shaft, and this pinion gear 141 meshes with a ring gear 103 fixed to the crankshaft 10 of the internal combustion engine 100, thereby transmitting rotational driving force to the crankshaft 10. To do. The pinion gear 141 is detached from the ring gear 103 except when the starter motor 140 is cranking the internal combustion engine 100.

  The auxiliary motor 130 rotationally drives the crankshaft 10 of the internal combustion engine 100 when the internal combustion engine 100 that has been idle-stopped is restarted. However, the auxiliary motor 130 alone cannot give the crankshaft 10 enough acceleration to crank the internal combustion engine 100 and complete the start-up. The auxiliary motor 130 is connected to one end side of the crankshaft 10 via a winding transmission mechanism including the belt 134 and the pulleys 102 and 133 as elements.

  The auxiliary motor 130 is an electric auxiliary device attached to the vehicle or the internal combustion engine 100, for example, an electric compressor that compresses refrigerant of an air conditioner for air conditioning in the vehicle interior, or an electric motor for circulating cooling water of the internal combustion engine 100. The motor may be a drive source such as a water pump.

  The alternator 110 has a function as a generator that generates electric power by receiving a driving force transmitted from the crankshaft 10 of the internal combustion engine. The alternator 110 is connected to one end side of the crankshaft 10 via a winding transmission mechanism including a belt 113 and pulleys 101 and 112 as elements.

  A transmission 120 that connects the internal combustion engine 100 and the vehicle axle and thus the drive wheels is installed on the other end side of the crankshaft 10. The transmission 120 includes known torque converters and automatic transmissions.

  An ECU (Electronic Control Unit) 0 that controls the internal combustion engine 100, the starter motor 140, the auxiliary motor 130, and the like is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface of the ECU 0 includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle sensor (engine rotation sensor) that detects a rotation angle of the crankshaft 10 and an engine rotation speed. An angular signal b, an accelerator opening signal c output from a sensor that detects the amount of depression of the accelerator pedal as an accelerator opening (in other words, a required load on the internal combustion engine 100), an intake in the intake passage 3 (particularly, the surge tank 33). Detects the intake air temperature / intake pressure signal d output from the sensor that detects the air temperature and the intake pressure, the coolant temperature signal e output from the water temperature sensor that detects the coolant temperature suggesting the temperature of the internal combustion engine, and the amount of depression of the brake pedal At the brake signal f output from the sensor, the multiple cam angles of the intake camshaft or exhaust camshaft A cam angle signal g outputted from the beam angle sensor, battery voltage / current signal h or the like to be output from the sensor for detecting the terminal voltage and / or terminal current of the vehicle-mounted battery is input.

  The crank angle sensor typically transmits a pulse signal as the crank angle signal b every time the crankshaft 10 rotates by 10 ° CA (crank angle). However, the crank angle sensor does not output 36 pulses during one rotation of the crankshaft 10, but a specific rotation phase angle of the crankshaft 10, specifically 0 ° CA and 360 ° CA. , And at 180 ° CA and 540 ° CA, pulse loss occurs. Based on this deficiency, it is possible to know the absolute angle (posture) of the crankshaft 10, in other words, the current position of the piston of each cylinder 1. On the other hand, the cam angle sensor outputs a pulse signal as the cam angle signal g for each angle obtained by dividing one rotation of the camshaft by the number of cylinders. In the case of a three-cylinder engine, every time the camshaft rotates 120 °, a pulse signal is output every 240 ° CA if converted to a crank angle.

  From the output interface of the ECU 0, 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 an opening operation for the EGR valve 23. A signal l, a control signal n for controlling the alternator 110, a control signal p for controlling the starter motor 140, a control signal q for controlling the auxiliary motor 130, etc. 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 obtains 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, and requests corresponding to the intake amount charged in the cylinder 1. Various operation parameters such as the fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, required EGR rate, power generation amount or output voltage of the alternator 110 are determined. The ECU 0 applies various control signals i, j, k, l, n, p, q corresponding to the operation parameters via the output interface.

  The ECU 0 of the present embodiment executes an idle stop that stops the idle rotation of the internal combustion engine 100 when a predetermined idle stop condition is satisfied. The ECU 0 has a brake pedal depression amount that is equal to or greater than a threshold value (the brake pedal is depressed), an internal combustion engine cooling water temperature that is higher than a predetermined level, an in-vehicle battery charge amount or a terminal voltage that is higher than a predetermined level, a shift range Is the driving range, the absolute value of the slope of the road where the vehicle is located is less than the predetermined value, and the magnitude of the negative pressure stored in the brake booster (differential pressure between atmospheric pressure and brake booster negative pressure) is the threshold value There are various conditions such as that there is a history of acceleration to a certain vehicle speed (for example, 10 km / h) or more since the end of the previous idle stop, and the current vehicle speed is a certain vehicle speed (for example, 9 km / h) or less. 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 100 is restarted. In ECU0, the brake pedal depression amount is 0 or less than a threshold value close to 0 (the brake pedal is no longer depressed), and conversely, the brake pedal depression amount is further increased (the brake pedal is further depressed). The amount of depression of the accelerator pedal exceeds the threshold value (the accelerator pedal is depressed), the negative pressure stored in the brake booster has dropped below the threshold value, and the predetermined time (3 minutes) has elapsed in the idle stop state. It is determined that the idle stop end condition is satisfied by any one of the elapsed time and the like. The threshold value to be compared with the depression amount of the accelerator pedal is usually a value between 5% and 10% of the depression amount at which the accelerator is fully opened. However, this threshold value may be 0 or a value close to 0.

  However, in the present embodiment, cranking for starting the internal combustion engine 100 is not started simply by removing the driver's foot from the brake pedal.

  FIG. 3 shows a procedure example of processing executed by the ECU 0 of the present embodiment when the internal combustion engine is restarted. When the ECU 0 starts idling stop of the internal combustion engine 100 before the vehicle stops, the brake pedal depression amount becomes 0 or less than a threshold close to 0 before the vehicle speed or the engine speed becomes 0 ( In step S1), the crankshaft 10 of the internal combustion engine 100 is driven by the auxiliary motor 130 to maintain the rotational speed within a predetermined value or within a predetermined range (for example, 300 rpm to 400 rpm) (step S2), and a crank angle signal. The current stroke of each cylinder 1 is determined with reference to b and the cam angle signal g (step S3).

  The reason why the rotation of the crankshaft 10 is maintained by the auxiliary motor 130 is to maintain a state in which the crank signal b and the cam angle signal g having a high S / N ratio are output from the crank angle sensor and the cam angle sensor to the ECU 0. It is not for performing cranking for starting the internal combustion engine 100 by the auxiliary motor 130. The determination of the current stroke of each cylinder 1 with reference to the crank angle signal b and the cam angle signal g requires a time of several commas. In steps S2 and S3, cranking by the starter motor 140 is not yet performed.

  If the amount of depression of the accelerator pedal becomes equal to or greater than a threshold value within a predetermined period (for example, several seconds to ten seconds) after the driving of the crankshaft 10 by the auxiliary motor 130 is started (step S4), the starter motor Execution of cranking by 140, fuel injection and ignition are started (step S5). In step S5, it is possible to determine the fuel injection timing and ignition timing in each cylinder 1 using the result of the stroke determination of each cylinder 1 performed in step S3 as it is. The cranking is finished when the internal combustion engine 100 has reached the first explosion to the consecutive explosion and the rotation speed of the crankshaft 10 exceeds a determination value determined according to the coolant temperature or the like (assuming that the explosion has been completed).

  On the other hand, if the accelerator pedal depression amount does not exceed the threshold value within a predetermined period after the driving of the crankshaft 10 by the auxiliary motor 130 (steps S4 and S8), the vehicle speed is 0 or less than the threshold value close to 0. If the vehicle has stopped (the vehicle has stopped) (step S6), or if the amount of depression of the brake pedal has increased again to exceed the threshold (step S7), the driver has an intention to reaccelerate the vehicle. Therefore, the driving of the crankshaft 10 by the auxiliary motor 130 is stopped (step S9), and the internal combustion engine 100 is completely stopped.

  In the present embodiment, an auxiliary motor 130 capable of driving the output shaft 10 of the internal combustion engine 100 is provided separately from the starter motor 140 used for cranking for starting the internal combustion engine 100, and the vehicle stops. In the case where the idling stop of the internal combustion engine 100 is started before starting, the auxiliary motor 130 drives the output shaft 10 of the internal combustion engine 100 to rotate the brake pedal when the depression amount of the brake pedal becomes 0 or a threshold value close to zero. Is maintained for a predetermined period, and if the amount of depression of the accelerator pedal becomes equal to or greater than the threshold value within the predetermined period, cranking for starting the internal combustion engine 100 is performed using the starting motor 140, otherwise, the auxiliary motor 130 The vehicle which stops the drive of the output shaft 10 of the internal combustion engine 100 by this was comprised.

  According to the present embodiment, when the idling stop of the internal combustion engine 100 is started before the vehicle stops, if the driver removes his foot from the brake pedal but does not attempt to step on the accelerator pedal, the engine Do not start ranking. Therefore, restart of the internal combustion engine 100 unintentional to the driver's intention is avoided, fuel is not wasted, and an opportunity for noise generation by the gears 141 and 103 interposed between the starter motor 140 and the crankshaft 10 is avoided. Can be reduced.

  Further, prior to the start of cranking by the starting motor 140, the crankshaft 10 can be accelerated to a certain rotational speed by the auxiliary motor 130, and the stroke determination of each cylinder 1 can be completed. The cranking period when the internal combustion engine 100 is restarted by stepping on is shortened. That is, the restart of the internal combustion engine 100 in accordance with the driver's intention is accelerated, and the generation time of noise by the gears 141 and 103 is also shortened, which contributes to the improvement of the vehicle's NV (Noise and Vibration).

  The present invention is not limited to the embodiment described in detail above. For example, the driving of the crankshaft 10 by the auxiliary motor 130 prior to the start of cranking by the starter motor 140 can also be performed at an idle stop of the internal combustion engine 100 after the vehicle stops.

  That is, if the amount of depression of the brake pedal becomes 0 or less than a threshold value close to 0 during idle stop, the crankshaft 10 of the internal combustion engine 100 is driven by the auxiliary motor 130 so that the rotational speed is within a predetermined value or a predetermined range. The current stroke of each cylinder 1 is determined with reference to the crank angle signal b and the cam angle signal g. Thereafter, if the amount of depression of the accelerator pedal becomes 0 or a threshold value close to 0 within a predetermined period, cranking for starting the internal combustion engine 100 by the starter motor 140, fuel injection, and ignition are started. On the other hand, if the accelerator pedal depression amount does not exceed 0 or a threshold value close to 0 within a predetermined period, or if the brake pedal depression amount increases again to exceed the threshold value, the crankshaft by the auxiliary motor 130 is increased. The driving of 10 is stopped.

  In addition, the specific configuration of each unit and the processing procedure can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to a control device mounted on a vehicle.

0 ... Control unit (ECU)
10 ... Output shaft (crankshaft) of internal combustion engine
DESCRIPTION OF SYMBOLS 100 ... Internal combustion engine 130 ... Auxiliary motor 140 ... Starting motor (starter motor, cell motor)

Claims (1)

Apart from the starting motor used for cranking for starting the internal combustion engine, an auxiliary motor capable of driving the output shaft of the internal combustion engine is provided,
When the idling stop of the internal combustion engine is started before the vehicle stops, when the brake pedal depression amount is 0 or less than a threshold value close to 0, the auxiliary motor drives the output shaft of the internal combustion engine to rotate it. If the accelerator pedal depression amount exceeds the threshold within the predetermined period, cranking for starting the internal combustion engine is performed using the starter motor, otherwise the internal combustion engine is driven by the auxiliary motor. A vehicle that stops driving the output shaft.

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