DE102008001275A1 - Stop control device for diesel combustion engine of vehicle, has stop control unit implemented by adjustment of output shaft load, where decreasing speed of drive of output shaft is reduced when compared with those within region before stop - Google Patents

Abstract

The device has a stop control unit implemented by carrying out an adjustment of combustion degree by the control of a combustion auxiliary device (14), by the adjustment of a discharge load through the control of drive of an exhaust auxiliary device or by the adjustment of output shaft load through the control of drive of a drive auxiliary device (61). A point, at which the speed of output shaft (30) is zero, is directly provided before a stop in a given region. Decreasing speed of drive of the output shaft is reduced when compared with those within another region that is before the stop. An independent claim is also included for a stop control system for an internal combustion engine.

Description

The The present invention relates to a stop control apparatus and a stop control system for an internal combustion engine, which performs a stop control of a rotation of the internal combustion engine.

The JP-59-43952 A discloses a control device that increases a flow passage area of an exhaust gas recirculation passage (an EGR passage) that connects an exhaust system of a diesel engine with its intake system after an ignition switch is turned off, thus increasing a recirculation exhaust gas amount (EGR amount). As an amount of exhaust gas recirculated to a combustion chamber of the diesel engine is increased, combustion in the combustion chamber is restricted, ultimately promoting a stop of the diesel engine. In addition, the stop of the diesel engine is promoted by interrupting a fuel injection.

The Inventors have discovered that a phenomenon occurs that a fluctuation of a rotational speed of an output shaft in a Case of a quick stop of the diesel engine considerably becomes. It is considered that this is due to because at the time when a speed of an output shaft of the Diesel engine becomes essentially zero, an increase a force occurs, which depends on a rotation angle the output shaft acts to turn the output shaft in the reverse direction to turn. In particular, it is considered that if a piston in the vicinity of a compression stroke end position (a Position of the top dead center during a compression stroke) stops, a compression gas acts to push the piston back, which is an occurrence of a force for rotating the output shaft in the generated in reverse direction.

It takes into account that a reduction in a speed at the time of stopping the diesel engine by progressing Increasing the amount of EGR or progressing the fuel injection interruption is mitigated. Corresponding This requires it when a piston in the vicinity of the compression stroke end position stops a longer time that a compression gas is in the combustion chamber from a sliding gap of a piston ring or the like auszutritt. Accordingly, an exit amount of the compression gas increases, so that the force of the compression gas to push back the piston is reduced, which ultimately makes it possible makes, the fluctuation of a speed when stopping the engine to restrict.

The Inventors have also found that in a given speed range, which is lower than an idle number range, the fluctuation of one Speed of the output shaft is noticeable. It is taken into account that this phenomenon corresponds in a speed range to a resonant frequency range of a flywheel occurs with the output shaft for limiting the fluctuation of Speed of the diesel engine is connected. The speed range corresponding to the resonant frequency range of the flywheel is usually designed to provide a speed range a drive of the diesel engine in such a way avoid being within a speed range, which is less than an idle speed range. Therefore, if a reduction speed of the rotational speed in stopping the diesel engine is small, the time during which the speed is within the above-mentioned speed range remains longer, whereby the fluctuation of the speed of the output shaft increases becomes.

Even in a diesel engine not equipped with the flywheel is, a resonant frequency range through the other element, connected to an output shaft of the diesel engine is, to be present. In this case, the problem arises that a fluctuation of a speed of the output shaft increases, thereby causes the time during which a speed of the Output shaft in the resonant frequency range remains longer becomes. A gasoline engine may stop at the engine also have a similar problem.

The The present invention has been made in view of the above problem and it is an object of the present invention to provide a stop control apparatus and to provide a stop control system for an internal combustion engine, which can stop the engine gently.

An aspect of the present invention is provided with a stop determination device that determines a presence / absence of a stop command of an internal combustion engine, and an auxiliary device control device that drives a combustion auxiliary device that is a degree of combustion by controlling a state of a mixture supplied to a combustion chamber of the internal combustion engine , and also controls a drive of at least one auxiliary device from an exhaust auxiliary device that controls an exhaust state of the internal combustion engine, or a driving auxiliary device that is driven by the output shaft. The auxiliary device control device executes a stop control in a case where an existing stop command has been determined by the stop determination device as follows. That is, the setting of Burning and at least one setting of an exhaust load by controlling the drive of the exhaust auxiliary device or an adjustment of an output shaft load by controlling the drive of the driving auxiliary device is performed by controlling the combustion auxiliary device. Accordingly, in a first predetermined range immediately before a stop having a point at which a rotational speed of the output shaft in the internal combustion engine becomes zero, a reduction rotational speed of the output shaft is compared with that within a second range immediately before a stop which is present the first area immediately before a stop is lowered.

According to this Construction will be in the first area just before a stop the reduction speed of the speed (a positive value when a speed of change of the speed is a negative value is) compared with that within the second area immediately before a stop, which is in front of the first area immediately before a stop, lowered. Therefore, the internal combustion engine results in a stop in a state where the reduction speed the speed is weakened. This allows the speed fluctuation the output shaft, which in a fast stopping of the engine is generated, is reduced, so that the internal combustion engine can be stopped gently.

additionally For example, the decrease speed in the second area is immediate before a stop greater than in the first area immediately before a stop. Therefore, even in one case, in the resonance frequency range in which a change in the Speed of the engine is particularly noticeable within the second area immediately before a stop, the Speed quickly through the resonant frequency range. This allows the time during which the Speed of the output shaft within the resonant frequency range remains, is shortened, bringing the speed change the output shaft is made small.

Further in addition to adjusting the degree of combustion by the combustion auxiliary device, the stop control by Performing at least the adjustment of the discharge load (Exhaust load) through the exhaust auxiliary device (exhaust auxiliary device) or adjusting the output shaft load by the drive auxiliary device executed. Therefore, the number of adjusters compared with a case of executing the stop control only by adjusting the degree of combustion greater made. This can easily the aforementioned stop control realize that the reduction speed of the speed in the first Range is made small immediately before a stop and made large in the second area immediately before a stop is.

1 FIG. 15 is a drawing showing an overall construction of an engine system in an embodiment of the present invention. FIG.

2 Fig. 12 is a drawing showing a construction of a supercharger in the present embodiment.

3 FIG. 10 is a flowchart showing the process order of a stop control of a diesel engine in the present embodiment.

4 FIG. 15 is a drawing showing a procedure of setting an injection amount and a throttle opening for the stop control in the present embodiment.

5 FIG. 13 is a timing chart exemplifying a mode of the stop control in the present embodiment.

Detailed description the embodiments

below is a stop control device for an internal combustion engine, that on a common rail vehicle diesel engine used in an embodiment of the present invention will be explained with reference to the accompanying drawings.

First shows 1 an overall construction of an engine system in the present embodiment.

As in 1 is shown is a four-cylinder diesel engine 10 with an inlet passage 12 and an electrically controlled throttle valve 14 provided, which is formed from a butterfly valve body which in the inlet passage 12 is arranged. The throttle valve 14 is of the normally open type. An opening sensor 16 for detecting an opening of the throttle valve 14 is in the vicinity of the throttle valve 14 intended.

The inlet passage 12 stands with a combustion chamber 24 connected by a cylinder block 20 and a piston 22 is defined when an inlet valve 18 is open. High pressure fuel is from a common rail 26 to a fuel injector 28 supplied and a front portion of the fuel injector 28 is arranged so that it enters the combustion chamber 24 protrudes. This construction allows injection of fuel to the combustion chamber 24 ,

When fuel enters the combustion chamber 24 the fuel is injected by compression of the combustion chamber 24 self-ignited to generate energy. This energy is called a rotational energy of an output shaft (crankshaft 30 ) of the diesel engine 10 through the piston 22 decreased. The crankshaft 30 is with a flywheel 32 for limiting a speed change of the crankshaft 30 connected. This flywheel 32 For example, it can be a flywheel with two masses. A crank angle sensor 34 for detecting a rotation angle of the crankshaft 30 is in the vicinity of the crankshaft 30 intended. For limiting an increase in a temperature of the diesel engine 10 By burning the fuel, cooling water flows into the cylinder block 20 , The cylinder block 20 is with a water temperature sensor 36 provided for detecting a temperature of the cooling water.

The fuel gets through the fuel injector 28 into the combustion chamber 24 injected to generate a combustion. Thereafter, a gas supplied to the combustion becomes an exhaust passage 40 discharged as an exhaust gas when an exhaust valve 38 is open.

The inlet valve 18 and the exhaust valve 38 Both are driven so that they are driven by a rotational force of the crankshaft 30 be opened / closed. That is, an intake cam 42 and an exhaust cam 44 with a rotation of the crankshaft 30 to thereby cause the intake valve 18 and the exhaust valve 38 be driven so that they open / close. In the present embodiment, since the diesel engine 10 uses a four-stroke engine, each rotation period of intake cam 42 and the exhaust cam 44 a twofold of a rotational period of the crankshaft 30 ,

The outlet passage 40 and the inlet passage 12 are with an outlet gas recirculation passage (EGR passage 50 ) for recirculating an exhaust gas in the exhaust passage 40 or exhaust gas passage to the inlet passage 12 Mistake. The EGR passage 50 is with an EGR valve 52 provided for adjusting its flow passage area.

An electrically controlled device (ECU 70 ) actuates various actuators, such as the injection injector 28 on the basis of a detection value of each sensor for detecting an operating state of the diesel engine 10 and a detection value of an accelerator position sensor 58 for detecting a suppression amount of an accelerator pedal. The power of a battery 80 is through an ignition switch 72 , a major relay 74 and a power supply line L1 to the ECU 70 fed.

When the energy from the battery 80 to the ECU 70 supplied, monitors the ECU 70 an on / off state of the ignition switch 72 through a signal line L3. In addition, if the ignition switch 72 is off, to maintain a supply of power to the ECU 70 until after-treatment, which must be done before stopping the ECU 70 is completed, the ECU 70 a drive signal through the signal line L2 to the main relay 74 out. Accordingly, even after the ignition switch 72 is off, the energy of the battery 80 through the main relay and the power supply line L1 to the ECU 70 continues to be fed until after-treatment in the ECU 70 is completed.

Next are various auxiliary devices used in the diesel engine 10 are mounted, explained. The auxiliary devices passing through the crankshaft 30 (the power tool) include a generator 61 , a fuel pump 62 and a refrigerant compressor 63 ,

The generator 61 is formed of a stator (not shown) having a stator coil 61a a rotor (not shown) driven by a driving force of the crankshaft 30 is rotated, and a rotor coil 61b to excite the rotor. In addition, when the rotor is supplied to the rotor coil by supplying exciting current 61a is excited, the rotor is rotated, and thereby an induced electromotive force in the stator coil 61a generates the battery 80 with the generated electromotive force loads.

The ECU 70 controls the excitation current that enters the rotor coil 61b in accordance with a voltage B of the inducing electromotive force in the stator coil 61a is generated, flows, bringing an energy generator size of the generator 61 is controlled. In a case where a value of the voltage B is a predetermined adjustment voltage at a normal operation time of the diesel engine 10 is the excitation current that is in the rotor coil 61b flows, turns off, and in a case where it does not exceed the predetermined setting voltage, the exciting current is turned on. By repeating this on / off operation, the supply voltage B to the battery is controlled, so that a setting voltage is controlled.

The fuel pump 62 is due to a driving force of the crankshaft 30 driven to repeatedly perform a suction and discharge of the fuel. As a result, a high-pressure fuel corresponding to an injection pressure of the fuel injector 28 continuously to the commonrail 26 fed.

The fuel pump 62 is with a suction control valve 62a (SCV) of an electromagnetically driven type disposed at the fuel suction portion thereof, and low-pressure fuel supplied from a fuel tank 62c through a feed pump 62b is sucked in by the suction control valve 62a to a fuel chamber (not shown) of the pump 62 sucked. When it causes the suction control valve 62a opens, the low pressure fuel from the feed pump 62b supplied to the fuel chamber and the sucked low pressure fuel, which is to the Commonrail 26 is issued, is highly pressurized. When it causes the suction control valve 62a closes, the low-pressure fuel from the feed pump 62b not supplied to the fuel chamber and a supply of the high-pressure fuel to the common rail 26 is stopped.

A detection value of a fuel pressure in the common rail 26 (a line pressure) by a common rail pressure sensor 26a becomes the ECU 70 entered. The ECU 70 calculates a target value of a common rail pressure (injection pressure) based on an engine speed and a fuel injection amount at all times during a normal operation time of the diesel engine 10 , The ECU also controls 70 a discharge amount of the high-pressure fuel by the fuel pump 62 fed back, so that an Istleitungsdruck becomes equal to a nominal line pressure. In particular, a target output amount by the fuel pump 62 determined based on a deviation between the Istleitungsdruck and the target line pressure and an opening of the Saugsteuerventils 62a is controlled in response to the target output amount, whereby a discharge flow amount of the high-pressure fuel is controlled.

The coolant compressor 63 is a part of an air conditioner for air conditioning an interior of a vehicle and is driven by a driving force of the crankshaft 30 driven to compress and dispense a coolant flowing in a coolant passage. The coolant compressor 63 is through an electromagnetic clutch 63a with the crankshaft 30 connected. The ECU 70 controls an engagement / disengagement operation of the electromagnetic clutch 63a to a coolant discharge amount of the refrigerant compressor 63 to control. An ECU for air-conditioning (not shown) determines a target value of a temperature of air that has passed through an evaporator (a target temperature after the evaporator) based on an indoor set temperature set by an occupant, an outdoor temperature, an extent of Sunlight and the like. At a normal operating time of the diesel engine 10 becomes the pushing-disengaging operation of the electromagnetic clutch 63a controlled in response to the setpoint temperature after the evaporator.

Next is a loader 64 , which represents one of the auxiliary devices used in the diesel engine 10 are mounted, with reference to 2 explained.

The loader 64 pressurizes intake air using an exhaust gas pressure as a drive source with pressure and is from a turbine 64a , a compressor 64b and a rotary shaft 64c educated. The turbine 64a is in the outlet passage 40 and is governed by an outlet gas pressure in the exhaust passage 40 turned. The compressor 64b is in the inlet passage 12 arranged and is through the rotary shaft 64c with the turbine 64a connected. In addition, when the turbine rotates 64 The compressor is spinning 64b with the rotary shaft 64c to the intake air in the intake passage 12 through the compressor 64b to apply pressure, whereby a recharge is performed.

An upstream portion and a downstream portion of the turbine 64a in the outlet passage 40 are through a bypass passage 40a in conjunction with a wastegate valve 40b is provided. The ECU 70 controls an operation of the wastegate valve 40b and opens the wastegate valve 40b at a normal operating time of the diesel engine 10 to prevent the occurrence of excessive boost pressure.

The ECU 70 calculates an EGR ratio, that is, a ratio between an EGR amount and a new gas, based on an accelerator pedal position and an engine speed, and calculates a target throttle opening based on this EGR ratio. In addition, the ECU calculates 70 at a normal operating time of the diesel engine 10 a target boost pressure from a target torque. An opening of the wastegate valve 40b is feedback controlled, so that a Istladedruck, by the boost pressure sensor 12a is detected, is equal to the target contact pressure.

When the ignition switch 72 is off, the ECU determines 70 in that a stop command of the diesel engine 10 is issued and performs a stop control for stopping the diesel engine 10 out.

Next is the process order of the stop control of the diesel engine 10 in the present embodiment with reference to 3 explained. This stop processing is performed by the ECU in a given period 70 repeatedly executed.

First, at step S10, it is determined whether the ignition switch 72 is off or not. This process serves to determine if a stop command of the diesel engine 10 is issued or not. If it is determined that the ignition switch 72 is turned off, the process goes to step S11, where it is determined whether or not an engine speed Ne is substantially zero.

In a case where it is determined that the engine rotation speed Ne is substantially zero (S11: YES) because the stop control is not necessary, a series of processes ending in 3 is shown. In a case where it is determined that the engine rotation speed Ne is not substantially zero (S11: NO), the process proceeds to step S12.

At step S12, it is determined whether or not the engine rotation speed Ne is based on a detection value of the crank angle sensor 34 is less than a predetermined rotational speed α (for example, 300 revolutions per minute) or not. When it is determined that it is not less than the predetermined rotational speed α (S12: NO), the stop control of the diesel engine at step S14 10 performed in an open control.

below a detail of the process at step S14 is explained.

First, the fuel injector 28 is controlled as a combustion auxiliary device so as to be closed to perform a fuel injection cutoff for stopping injection of fuel, and also the throttle valve becomes 14 is controlled as a combustion auxiliary device so that it is completely closed to restrict intake air. According to these controls, the degree of combustion is maximally limited by a reduction speed of the rotational speed of the crankshaft 30 to increase.

In addition, at step S14, driving is performed by each of the generator 61 , the fuel pump 62 and the refrigerant compressor 63 maximized as power assist devices to maximize drive torque on the crankshaft 30 is provided (output shaft load), whereby the reduction speed of the rotational speed of the crankshaft 30 is increased.

In particular, an energy generation amount of the generator 61 by maximizing an excitation current that is in the rotor coil 61b flows. Accordingly, the driving torque of the rotor in the generator 61 maximizes, bringing the reduction speed of the crankshaft speed 30 is increased.

Regarding the fuel pump 62 a target line pressure is set at a maximum (for example, 180 MPa). Accordingly, the supply flow rate of the high pressure becomes the common rail 26 maximizes the drive torque of the fuel pump 62 to maximize. Therefore, the reduction speed becomes the rotational speed of the crankshaft 30 elevated. The fuel injector 28 stops injecting the fuel and is in operation (idle) to transfer the excess fuel to the fuel tank 62c return.

With regard to the refrigerant compressor 63 the setpoint temperature after the evaporator is set to a minimum. According to this, since a refrigerant discharge flow rate of the refrigerant compressor 63 is maximized to the drive torque of the refrigerant compressor 63 to maximize the reduction speed of the crankshaft speed 30 elevated.

At step S14, an exhaust amount that is the loader 64 bypasses as an outlet auxiliary device made small, thereby increasing a line resistance until an exhaust gas through the exhaust passage 40 is delivered to outside. Then, at the time of expelling and discharging the combustion gas in the combustion chamber 24 through the piston 22 the output resistance (the discharge load). Accordingly, the reduction speed becomes the rotational speed of the crankshaft 30 elevated.

When Next are details of the process at step S16, Step S18 and step S20 explained.

In a case where it is determined at step S12 that the rotational speed Ne of the crankshaft 30 is less than the predetermined speed α (S12: YES), the stop control of the diesel engine 10 in a feedback control at step S16, step S18 and step S20.

At step S16, a target decreasing rotational speed ΔNEt in accordance with a rotational speed at each time is calculated on the basis of a detection value of the crank angle sensor 34 calculated. Specifically, the target reduction speed ΔNEt is defined by a reduction amount of a rotation speed per unit time. A specific example of the unit of time includes a predetermined period of time in which the processing performed in 3 is shown, or a predetermined interruption period.

The Speed is preferably a speed obtained by averaging a speed change which is caused by a change of a clock becomes.

At the next step S18, an actual reduction speed ΔNE calculated. A reduction speed with respect to an average speed obtained by averaging the speed change caused by the change of the clock is calculated. This decreasing rotational speed is calculated as, for example, by calculating an average rotational speed in an angular range that is an integral multiple of a value obtained by dividing an angle corresponding to a combustion cycle ("720 ° CA" in a four-stroke engine) by the number of cylinders Difference of average speed between adjacent angular ranges calculated.

At step S20, a throttle opening et and a fuel injection amount QFIN are set on the basis of the target reduction speed ΔNEt and the actual reduction speed ΔNE. This setting is made using a map that is displayed in 4 is shown. This map defines a fuel injection amount QFIN and a throttle opening et from a difference between the target reduction speed ΔNEt and the actual reduction speed ΔNE and the rotational speed.

The target reduction speed ΔNEt defined by the map is set to a larger value as the engine speed is larger. The target reduction speed ΔNEt is set to a smaller value when the rotation speed is small. The reason for using not only the difference between the target decreasing rotational speed ΔNEt and the actual decreasing rotational speed ΔNE but also the rotational speed is that even if the difference is the same when the rotational speed is different, an accurate value other than a throttle opening et or an injection amount may differ. For example, when the rotational speed is lowered to some extent, it is not suitable to increase an injection amount, and it is preferable that the decreasing rotational speed of the rotational speed only by the throttle valve 14 to control.

At step S22, an output wave load is generated by each of the following elements 61 , Fuel pump 62 and refrigerant compressor 63 minimized as driving aids and also an exhaust load through the loader 64 minimized as an exhaust auxiliary device.

More specifically, at step S22, with respect to the generator 61 an excitation current to the rotor coil 61b stopped to cause an energy generation amount to become zero. Regarding the fuel pump 62 a desired line pressure is set to a minimized value of values in which an injection of fuel from the fuel injector 28 possible (for example 25 MPa). With regard to the refrigerant compressor 63 becomes the electromagnetic clutch 63a controlled so that it is disengaged. Regarding the loader 64 becomes the wastegate valve 40b controlled to a fully open state.

In the feedback control by step S16, step S18, and step S20, a decreasing rotational speed is made by executing an adjustment of the combustion degree by the fuel injector 28 and the throttle valve 14 as combustion auxiliary devices without depending on the setting of the output shaft load and the discharge load.

That's the throttle valve 14 is of a normally open type, when the power supply is stopped, the throttle valve 14 in a fully open state. Therefore, the power supply is continued to be performed for a predetermined time from a point where it is determined for the first time at step S11 that the rotational speed becomes substantially zero, and thus the power supply is preferably set so that the rotational speed is surely stopped.

5 exemplifies a mode of the stop control. 5 (a) shows an ON / OFF state of the ignition switch 72 . 5 (b) shows a vibration of the crankshaft 30 and 5 (c) shows a rotational speed Ne of the crankshaft 30 , 5 (d) shows an opening of the wastegate valve 40b . 5 (e) shows a line pressure, 5 (f) shows an output quantity QDF of fuel through the fuel pump 62 . 5 (g) shows a power generation amount QPG of the generator 61 . 5 reading (h) shows an output quantity QDR of the coolant through the refrigerant compressor 63 . 5 (i) shows a fuel injection amount QFIN through the fuel injector 28 and 5 (j) shows a throttle opening θt.

As in 5 is shown, according to the present embodiment, when the ignition switch 62 by a driver at a normal operating time of the diesel engine 10 and at an idle speed (700 revolutions per minute) of a crankshaft speed 30 is turned off, the wastegate valve 40b completely closed. As a result, the exhaust load is maximized.

When the ignition switch 72 is switched off, the line pressure is set to a maximum value (180 MPa), the output quantity of the fuel pump 62 is maximized, the amount of energy generated by the generator 61 is maximized and the output quantity of the coolant through the refrigerant compressor 63 is maximized. As a result, the output shaft load is maximized. When the ignition switch 72 is turned off, the fuel injection amount becomes by a process of complete closing of the fuel injector 28 zero and the throttle valve 14 is completely closed. As a result, the degree of combustion is minimized.

As described above, caused by the maximum exhaust load, the maximum output shaft load and the minimum combustion degree, the rotational speed of the crankshaft 30 (700 revolutions per minute) at the time when the ignition switch 72 is reduced to a maximum extent of reduction, until the speed through the resonant frequency range of the flywheel 32 passes (NE1 to NE2) (until it reaches 300 revolutions per minute). It should be noted that within the speed range, a range of one speed at a point where the ignition switch 72 is turned off, to a rotational speed of the lower limit NE1 in the resonance frequency region is designated as a second region immediately before a stop A2.

After that, at a point where the speed of the crankshaft 30 passes through the resonant frequency range, the wastegate valve 40b in a fully open condition and the discharge load is minimized. Further, at a point where the rotational speed of the crankshaft 30 passes through the resonant frequency range, the line pressure is set to the minimum values at which an injection of the fuel from the fuel injector 28 is possible. As a result, the output quantity of the fuel pump 62 Zero, the generator's energy generation amount 61 is zero and the discharge amount of the refrigerant compressor 63 is zero. As a result, the output wave load is minimized.

In addition, at a point of passing through the resonant frequency range, the fuel again becomes from the fuel injector 28 and then the fuel injection amount is progressively reduced to zero. At a point of passing through the resonant frequency range, the throttle valve becomes 14 opened again and then the opening is progressively reduced to zero. It should be noted that in one example, that in 5 (i) 2, the fuel injection amount is made zero before the rotational speed becomes zero, but the injection can be continued to be performed until the rotational speed becomes zero. Further, in an example that is in 5 (j) shown is the throttle valve 14 can be kept open until the speed becomes zero, but can be in a fully closed state before the speed becomes zero.

As described above, caused by the minimum exhaust load and the minimum output shaft load, the reduction speed of the rotational speed of the crankshaft 30 after a point at the time of passing through the resonant frequency range of the flywheel 32 made small. Within the speed range, an area smaller than the second area immediately before a stop A2 and also including a point at which the speed becomes zero is referred to as a first area immediately before a stop A1.

• (1) In dem ersten Bereich unmittelbar vor einem Stopp A1 einschließlich eines Punkts, an dem die Drehzahl Null wird, wird die Verringerungsdrehzahl der Drehzahl zur Zeit eines Durchführens der Stoppsteuerung verglichen mit jener in dem zweiten Bereich unmittelbar vor einem Stopp A2 vor diesem verringert. Daher resultiert die Dieselkraftmaschine 10 in einem Stoppen in einem Zustand, in dem die Verringerungsdrehzahl der Drehzahl verglichen mit einem Fall abgemildert ist, in dem die Drehzahl ohne Änderung der Verringerungsdrehzahl bei dem zweiten Bereich unmittelbar vor einem Stopp A2 gestoppt wird. Dementsprechend kann die Drehzahländerung, die zu der Zeit generiert wird, wenn die Dieselkraftmaschine 10 schnell gestoppt wird, verringert werden, was es möglich macht, die Drehung der Dieselkraftmaschine 10 sanft zu stoppen.
• (2) Die Verringerungsdrehzahl der Drehzahl in dem zweiten Bereich unmittelbar vor einem Stopp A2 einschließlich dem Resonanzfrequenzbereich von NE1 bis NE2 ist verglichen mit der in dem ersten Bereich unmittelbar vor einem Stopp A1 größer ausgeführt. Daher kann die Drehzahl der Kurbelwelle 30 schnell durch den Resonanzfrequenzbereich von NE1 bis NE2 verlaufen, wo die Änderung der Drehzahl der Dieselkraftmaschine 10 merklich ist. Dementsprechend kann die Zeit, während der die Drehzahl in dem Resonanzfrequenzbereich von NE1 bis NE2 verbleibt, verkürzt werden, was in einer Verringerung der Drehzahl der Kurbelwelle 30 resultiert. Insbesondere wird in dem zweiten Bereich unmittelbar vor einem Stopp A2 die Ausgangswellenlast durch jedes der Elemente Generator 61, Kraftstoffpumpe 62 und Kühlmittelkompressor 63 als Antriebshilfsvorrichtungen maximiert und ebenso wird die Auslasslast durch den Lader 64 als eine Auslasshilfsvorrichtung maximiert. Daher kann die Verringerungsdrehzahl verglichen mit einem Fall erhöht werden, in dem die Verringerungsdrehzahl der Drehzahl nur durch Beschränken des Verbrennungsgrads erhöht ist. Dementsprechend kann die Zeit, während der die Drehzahl in dem Resonanzfrequenzbereich von NE1 bis NE2 vorhanden ist, der in dem zweiten Bereich unmittelbar vor einem Stopp A2 vorhanden ist, verkürzt werden, was in einer Verringerung der Drehzahlschwankung der Kurbelwelle 30 resultiert, die in dem Resonanzfrequenzbereich von NE1 bis NE2 auftritt.
• (3) In der Stoppsteuerung, in der die Verringerungsdrehzahl der Drehzahl in dem zweiten Bereich unmittelbar vor einem Stopp A2 groß ausgeführt ist und in dem ersten Bereich unmittelbar vor einem Stopp A1 klein ausgeführt ist, ist es erforderlich, die Steuerung in dem ersten Bereich unmittelbar vor einem Stopp A1 zum Verringern der Drehzahländerung, die zu der Zeit eines schnellen Stoppens der Drehzahl generiert wird, höchst genau durchzuführen. Angesichts diesem stellt gemäß dem vorliegenden Ausführungsbeispiel die ECU 70 einen Sollwert der Drehzahl der Kurbelwelle 30 in dem ersten Bereich unmittelbar vor einem Stopp A1 ein und die berechnete Istdrehzahl wird rückgekoppelt gesteuert, so dass sie gleich dem Sollwert wird. Dementsprechend kann die Verringerungsdrehzahl in dem ersten Bereich unmittelbar vor einem Stopp A1 genau gesteuert werden, was es möglich macht, die Drehschwankung genau zu verringern, die bei dem schnellen Stoppen generiert wird.
• (4) Hinsichtlich der Stoppsteuerung in dem ersten Bereich unmittelbar vor einem Stopp A1 werden eine Drosselöffnung und eine Einspritzmenge auf der Grundlage einer Differenz zwischen einer Sollverringerungsdrehzahl ΔNEt und einer Istverringerungsdrehzahl ΔNE sowie einer Drehzahl eingestellt. Hierdurch kann die Stoppsteuerung der Drehung geeigneter durchgeführt werden.
• (5) Nachdem der Zündschalter 72 ausgeschaltet ist, wird in dem zweiten Bereich unmittelbar vor einem Stopp A2 in einem Fall, in dem die Drehzahl größer als die vorgegebene Drehzahl α ist, die Stoppsteuerung der Dieselkraftmaschine 10 durch eine offene Steuerung durchgeführt. Daher kann in dem zweiten Bereich unmittelbar vor einem Stopp A2, in dem es nicht erforderlich ist, die Verringerungsdrehzahl mit einer hohen Genauigkeit im Vergleich zu der in dem ersten Bereich unmittelbar vor einem Stopp A1 zu steuern, die Dieselkraftmaschine 10 mit einer einfachen Einstellung schnell gestoppt werden.
• (6) Die Verringerungsdrehzahl in dem ersten Bereich unmittelbar vor einem Stopp A1 wird durch den Verbrennungsgrad durch den Kraftstoffinjektor 28 und das Drosselventil 14 gesteuert. Hierdurch wird in einem Fall, in dem eine Anforderung zum Aufbringen eines positiven Moments auf die Kurbelwelle 30 auftritt, diese Anforderung richtig zugeordnet.

According to the present embodiment as described above, the following advantages can be obtained.

• (1) In the first region immediately before a stop A1 including a point where the rotational speed becomes zero, the reduction rotational speed is reduced at the time of performing the stop control compared with that in the second region immediately before a stop A2 before that. Therefore, the diesel engine results 10 in a stop in a state in which the reduction rotational speed of the rotational speed is alleviated compared with a case where the rotational speed is stopped without changing the reduction rotational speed at the second region immediately before a stop A2. Accordingly, the speed change generated at the time when the diesel engine 10 is stopped quickly, what makes it possible, the rotation of the diesel engine 10 to stop gently.
• (2) The reduction speed of the rotation speed in the second region immediately before a stop A2 including the resonance frequency range from NE1 to NE2 is made larger than that in the first region immediately before a stop A1. Therefore, the speed of the crankshaft 30 pass rapidly through the resonant frequency range from NE1 to NE2, where the change in the speed of the diesel engine 10 is noticeable. Accordingly, the time during which the rotational speed remains in the resonance frequency range from NE1 to NE2 can be shortened, resulting in a reduction in the rotational speed of the crankshaft 30 results. Specifically, in the second area immediately before a stop A2, the output shaft load through each of the elements becomes generator 61 , Fuel pump 62 and refrigerant compressor 63 is maximized as driving aids and also the discharge load is through the loader 64 as an exhaust auxiliary device. Therefore, the reduction speed can be increased as compared with a case where the reduction speed of the rotation speed is increased only by restricting the combustion degree. Accordingly, the time during which the rotational speed exists in the resonance frequency range from NE1 to NE2 existing in the second range immediately before a stop A2 can be shortened, resulting in a reduction in the rotational speed fluctuation of the crankshaft 30 results, which occurs in the resonance frequency range from NE1 to NE2.
• (3) In the stop control in which the reduction speed of the rotational speed in the second area immediately before a stop A2 is made large and is made small in the first area immediately before a stop A1, it is necessary to control in the first area immediately before a stop A1 for reducing the speed change, which is generated at the time of a quick stop of the speed to perform highly accurate. In view of this, according to the present embodiment, the ECU 70 a setpoint of the speed of the crankshaft 30 in the first area immediately before a stop A1 and the calculated actual speed is feedback-controlled, so that it becomes equal to the target value. Accordingly, the reduction speed in the first area immediately before a stop A1 can be accurately controlled, which makes it possible to accurately reduce the rotation fluctuation generated in the quick stop.
• (4) Regarding the stop control in the first area immediately before a stop A1, a throttle opening and an injection amount are set based on a difference between a target reduction speed ΔNEt and an actual reduction speed ΔNE and a rotational speed. Thereby, the stop control of the rotation can be more appropriately performed.
• (5) After the ignition switch 72 is turned off, in the second area immediately before a stop A2 in a case where the rotational speed is greater than the predetermined rotational speed α, the stop control of the diesel engine 10 performed by an open control. Therefore, in the second area immediately before a stop A2 in which it is not necessary to control the reduction speed with high accuracy as compared with that in the first area immediately before a stop A1, the diesel engine 10 be stopped quickly with a simple setting.
• (6) The reduction speed in the first area immediately before a stop A1 is determined by the degree of combustion by the fuel injector 28 and the throttle valve 14 controlled. Thereby, in a case where a request for applying a positive torque to the crankshaft 30 occurs, this request is assigned correctly.

(Other embodiment)

The The present invention is not limited to the description of the content limited to the above embodiments and the Main structures of the corresponding embodiments can each be combined in any way. Furthermore, can the present invention will be as follows.

In a case where a temperature of the diesel engine 10 is lower than a predetermined temperature β at the time of performing the stop control, it is preferable to inhibit the throttle valve 14 in a fully closed state. According to this, it can be surely avoided that the abnormality occurs that the throttle valve 14 is fixed in a fully closed state at the time of performing the stop control.

In the above embodiment, the fuel injector 28 at the time of operating the fuel pump 62 operated at idle during stop control, but a return line may be in the Commonrail 26 be provided to transfer excess fuel through the return line to the fuel tank 62c due. In this case, a pressure regulator is provided in the return line to return the excess fuel through the return line when the line pressure in the common rail 26 exceeds a predetermined value. The pressure regulator may be of a mechanical type in which a predetermined value is mechanically determined, or may be of an electrical type in which predetermined value may be determined electrically.

In the above embodiment, the reduction speed of the rotational speed in the first area immediately before a stop A1 becomes only by the degree of combustion by the fuel injector 28 and the throttle valve 14 but the reduction speed can be controlled by at least the output shaft load of each of the drive auxiliaries 61 . 62 and 63 , the exhaust load through the exhaust auxiliary device 64 or the degree of combustion are controlled.

In The above embodiment is the open control on the control of the reduction speed in the second area applied just before a stop A2, but the feedback control can be applied to this. Furthermore, the open control on the control of the reduction speed in the first area immediately before a stop A1 instead of the feedback control be applied.

In the above embodiment, an exhaust load by the loader 64 through an opening of the wastegate valve 40b set, but in a case of inserting a loader 64 in which a discharge capacity of the turbine 64a is variable, the discharge load can be adjusted by controlling the discharge capacity. In particular, the discharge load may be set so that the discharge capacity is made large to increase the discharge load, and the discharge capacity is made small to reduce the discharge load. Examples of loader 64 , in which the discharge capacity is variable, include a type in which the discharge capacity by adjusting a suction area of the turbine 64a is set, and a type in which the discharge capacity by adjusting a blade angle of the turbine 64a is set.

Examples of the exhaust auxiliary device that can adjust the exhaust load include, in addition to the above loader 64 an exhaust valve having an opening of the exhaust passage 40 established. By causing an opening of the exhaust valve to be small, the exhaust load can be obtained by a function of an engine brake.

Examples of the driving accessory that can adjust the output shaft load include in addition to the generator 61 , the fuel pump 62 and the refrigerant compressor 63 a water pump for circulating engine cooling water, an oil pump for lubricating for circulating lubricating oil, and a hydraulic power generation oil pump as operating-hydraulic-energy generating means for operating a hydraulic actuator.

In the above embodiment, the degree of combustion is by reducing an opening of the throttle valve 14 made small in the stop control, but because the pumping loss with a reduction in the opening of the throttle valve 14 is increased, an intake resistance (an intake load) at the time when the piston moves down becomes large. Accordingly, the reduction speed of the rotational speed of the crankshaft 30 be elevated. Examples of means for increasing the intake load include in addition to the throttle valve 14 a variable valve timing control device for varying a relative difference in rotational phases of the intake cam 42 to the crankshaft 30 and a variable valve characteristic device for changing a valve characteristic of the intake valve 18 , This allows a flow of the gas that enters the combustion chamber 24 flows, which results in performing a negative torque adjustment on the crankshaft 30 is applied.

Further, in a case where the intake valve 18 and the exhaust valve 38 are formed of electromagnetic valves, that is not through the inlet cam 42 and the exhaust cam 44 be driven, an opening / closing state of these valves, regardless of a rotation angle of the crankshaft 30 be determined freely. Accordingly, the intake load and the exhaust load can be controlled by an operation of the intake valve 18 and the exhaust valve 38 are set, whereby the stop control is performed.

In the above embodiment, the rotation speed range is after the ignition switch 72 is turned off in two areas, the first area immediately before a stop A1 and the second area immediately before a stop A2 divided in the stop control, but may be divided into three or more areas in the stop control. For example, the stop control may be divided by dividing the second area of an imminent stop A2 into the resonant frequency range of NE1 to NE2 and a range ahead of it, and the decreasing speed in the range before the resonant frequency range from NE1 to NE2 is smaller than that in the resonant frequency range of FIG NE1 to NE2 executed.

When a method of setting a target reduction speed ΔNEt can be the same value up to a lower limit speed NE1 in the resonance frequency range (NE1 to NE2) can and can be used be reduced thereafter. The target reduction speed ΔNEt can be changed step by step or continuously become.

A determination regarding the stop command to the diesel engine 10 is not on an OFF of the ignition switch 72 certainly. For example, in the diesel engine 10 equipped with a so-called idle stop function of temporarily and automatically stopping the diesel engine 10 in a stop state of a vehicle, a request for a temporary automatic stop in the presence of the stop command is determined.

The internal combustion engine according to the embodiment is not an internal combustion engine of the compression ignition type such as the diesel engine 10 , but may be a spark-ignited internal combustion engine, such as a gasoline engine.

In a case where an existing stop command has been determined (S10: YES), stop control is performed by performing adjustment of a combustion degree by a combustion aid (throttle valve, fuel injector) (S14, S20) and further by performing at least one setting of an exhaust load by an exhaust auxiliary device (supercharger) and an adjustment of an output shaft load by a driving auxiliary device (generator, fuel pump, refrigerant compressor) (S14). Thereby, in a first region immediately before a stop having a point at which a rotational speed of a crankshaft is zero, the reduction speed of the rotational speed is compared with that in a second region immediately before a stop immediately before the first region Stop is, verrin siege.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 59-43952 A [0002]

Claims (13)

Stop control device for an internal combustion engine ( 10 ) comprising: a stop determination device that detects a presence / absence of a stop command to the internal combustion engine ( 10 ) certainly; and an auxiliary device control device that drives a combustion auxiliary device ( 14 . 28 ), which sets a degree of combustion by controlling a state of a mixture flowing to a combustion chamber ( 24 ) of the internal combustion engine ( 10 ), and which drives a drive of at least one auxiliary device of an outlet auxiliary device ( 64 ), which has an exhaust state of the internal combustion engine ( 10 ) or a driving aid ( 61 . 62 . 63 ) through an output shaft ( 30 ) of the internal combustion engine ( 10 ), wherein: the auxiliary device control means, in a case where an existing stop command has been determined by the stop determination means, performs a stop control by executing the adjustment of the combustion degree by controlling the combustion auxiliary device (FIG. 14 . 28 and further by performing at least the adjustment of an exhaust load by controlling the drive of the exhaust auxiliary device (FIG. 64 ) or adjusting an output shaft load by controlling the drive of the drive auxiliary device ( 61 . 62 . 63 ) performs; and in a first predetermined area immediately before a stop having a point in which a rotational speed of the output shaft ( 30 ) Becomes zero, a reduction speed of the rotational speed of the output shaft ( 30 ) is lowered compared with that within a second area immediately before a stop that is before the first area immediately before a stop. Stop control device for an internal combustion engine ( 10 ) according to claim 1, wherein: the auxiliary device control means performs the stop control in the second region immediately before a stop in such a manner as to limit the degree of combustion and further an amount of at least the exhaust load or the output shaft load compared with an amount immediately before Performing the stop control is made larger. Stop control device for an internal combustion engine ( 10 ) according to claim 1 or 2, wherein: the exhaust auxiliary device ( 64 ) at least one loader ( 64 ) with a turbine ( 64a ), which are in an outlet passage ( 40 ) is arranged to be rotated by an outlet gas pressure, and a compressor ( 64b ) in an intake passage ( 12 ) is arranged, together with the turbine ( 64a ) for pressurizing inlet air; and the auxiliary device control means stop control by controlling a flow amount of an exhaust gas discharged from the combustion chamber (10). 24 ) of the internal combustion engine ( 10 ) into the turbine ( 64a ) to control the extent of the discharge load. Stop control device of an internal combustion engine ( 10 ) according to one of claims 1 to 3, wherein: the drive auxiliary device ( 61 . 62 . 63 ) at least one energy generator ( 61 ) for generating energy by a rotational force of the output shaft (FIG. 30 ) having; and the auxiliary device control means stop control by controlling a power generation amount of the power generator (FIG. 61 ) to control the amount of output wave load. Stop control device of an internal combustion engine ( 10 ) according to one of claims 1 to 4, wherein: the drive auxiliary device ( 61 . 62 . 63 ) at least one fuel pump ( 62 ) for pressurizing and discharging the fuel; and the auxiliary device control means stop control by controlling a fuel discharge amount of the fuel pump (FIG. 62 ) to control the amount of output wave load. Stop control device for an internal combustion engine ( 10 ) according to one of claims 1 to 5, wherein: the drive auxiliary device ( 61 . 62 . 63 ) at least one coolant compressor ( 63 ) for compressing and discharging refrigerant flowing in a refrigerant passage of an air conditioner; and the auxiliary device control means stops the stop control by controlling a refrigerant discharge flow amount of the refrigerant compressor (FIG. 63 ) to control the amount of output wave load. Stop control device for an internal combustion engine ( 10 ) according to one of claims 1 to 6, wherein: the combustion auxiliary device ( 14 . 28 ) at least one fuel injector ( 28 ) for supplying fuel to the internal combustion engine ( 10 ) having; and the auxiliary device control means stops the stop control by controlling a fuel injection amount of the fuel injector (FIG. 28 ) to control the degree of combustion. Stop control device of an internal combustion engine ( 10 ) according to one of claims 1 to 7, wherein: the combustion auxiliary device ( 14 . 28 ) at least one throttle valve ( 14 ) for adjusting a flow rate of the intake air to the combustion chamber ( 24 ) of the internal combustion engine 10 is supplied; and the auxiliary device control device stops the stop control by controlling a flow rate of the intake air through the throttle valve (FIG. 14 ) to to control the degree of combustion. Stop control device for an internal combustion engine ( 10 ) according to any one of claims 1 to 8, further comprising: a speed calculating means having an actual speed of the output shaft ( 30 ) and a setpoint setting device, which sets a desired value of a rotational speed of the output shaft ( 30 ) after an existing stop command has been determined by the stop determination means, wherein: the auxiliary device control means performs a feedback control so that the actual control rotational speed calculated by the rotational speed calculation means becomes equal to the target value after an existing stop command is determined. Stop control device for an internal combustion engine ( 10 ) according to claim 9, wherein: the auxiliary device control means performs the feedback control at least in the first region immediately before a stop. Stop control device for an internal combustion engine ( 10 ) according to one of claims 1 to 10, further comprising: a flywheel ( 32 ) connected to the output shaft ( 30 ) is mounted to reduce a rotational speed fluctuation of the output shaft ( 30 ), wherein: the second region immediately before a stop has a speed range which corresponds to a resonance frequency range of the flywheel ( 32 ) corresponds. Stop control device for an internal combustion engine ( 10 ) according to one of claims 1 to 11, wherein: the internal combustion engine ( 10 ) comprises a compression ignition engine. Stop control system for an internal combustion engine ( 10 ) with: the stop control device for the internal combustion engine ( 10 ) according to any one of claims 1 to 12; the combustion aid device ( 14 . 28 ); and at least the exhaust auxiliary device ( 64 ) or the drive auxiliary device ( 61 . 62 . 63 ).