JP2009085200A - Device for controlling diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve fuel consumption by quickly returning a diesel engine after an automatic stop condition is canceled to a normal combustion control while minimizing a load for reducing an ignition delay, when the automatic stop condition is canceled during braking due to establishment of the automatic stop condition. <P>SOLUTION: This device comprises an operation condition judging part 101 having at least a function for judging whether an automatic stop condition and a restarting condition is formed or not, and judging an operation condition of a vehicle mounting an engine 10, combustion control means 102, 103 for controlling combustion of the engine 10 based on the judgment of the operation condition judging part 101, a plurality of ignition delay reduction means with different properties for reducing an ignition delay τ<SB>id</SB>of the engine 10, and ignition delay control means for selectively driving and controlling a plurality of the ignition delay reduction means. The ignition delay control means selects a highest temperature-increasing effect in a cylinder out of the plurality of ignition reduction means when the automatic stop condition is canceled and an immediate response demand is high to the cancel factor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a diesel engine.

  For example, as disclosed in Patent Document 1, the engine is automatically stopped when a predetermined automatic stop condition is satisfied, and the automatic stop is automatically restarted when the predetermined restart condition is satisfied. / Restart control is being adopted for diesel engines.

When restarting a diesel engine that has been automatically stopped, it is necessary to inject fuel into a cylinder that is in the compression stroke when the diesel engine is stopped and to self-ignite the cylinder. Therefore, if the temperature decreases while the diesel engine is automatically stopped, the startability is often deteriorated. In order to solve such a problem, Patent Document 1 discloses a configuration in which supply of a large current to a glow plug attached to a diesel engine is set at the start of cranking, or a glow plug provided in a cylinder in a compression process when stopped. There is disclosed a technique for making the energization amount of the current larger than the energization amount of other glow plugs.
JP 2006-46251 A

  By the way, the automatic stop condition is satisfied depending on conditions such as when the driver releases the accelerator pedal, but this automatic stop is performed when the driver depresses the accelerator pedal again or when the battery load increases. It is necessary to release the condition, switch the diesel engine from the braking state to the operating state, and inject fuel into the cylinder in the compression stroke or the intake stroke to self-ignite the fuel mixture. In that case, as a means for shortening the ignition delay, as disclosed in Patent Document 1, when the ignition performance is improved solely depending on the energization amount of the glow plug at the time of restart, As a result, the operating rate of the glow plug will increase, leading to a shorter life of the glow plug. In addition, since the automatic stop condition can be frequently released before the diesel engine stops, it is desirable to suppress the use frequency of the glow plug to a necessary minimum.

  On the other hand, if direct ignition is attempted with a diesel engine that has been braked without using any means for shortening the ignition delay, such as a glow plug, engine stall due to misfire tends to occur, and exhaust performance also decreases.

  The present invention has been made in view of the above-mentioned problems, and when the automatic stop condition is canceled during braking due to the establishment of the automatic stop condition, the load for reducing the ignition delay is kept to a minimum and the speed is increased. It is another object of the present invention to provide a diesel engine control device that can improve fuel efficiency by returning the diesel engine after the automatic stop condition is released to normal combustion control.

  In order to solve the above-described problems, the present invention automatically stops the diesel engine when a predetermined automatic stop condition is satisfied, and automatically causes the diesel engine after the automatic stop when the predetermined restart condition is satisfied. In the control device for the diesel engine to be restarted, it has at least a function of determining success or failure of the automatic stop condition and the restart condition, and an operation state determination unit that determines an operation state of a vehicle equipped with the diesel engine; Combustion control means for controlling the combustion of the diesel engine based on the determination of the operating state determination unit, a plurality of ignition delay shortening means having different characteristics for shortening the ignition delay of the diesel engine, and during the automatic stop control of the diesel engine When the automatic stop condition is canceled, the ignition delay reducing means is selectively driven and controlled. An ignition delay control means, and the ignition delay control means, when the automatic stop condition is canceled, when the immediate response request for the cancellation factor is high, of the ignition delay shortening means, the temperature rise in the cylinder The control device for a diesel engine is characterized in that the one having a high effect is selected. In this mode, when the automatic stop condition is canceled during braking due to the establishment of the automatic stop condition, in an operating state where a quick response request for the canceling factor is high, an ignition effect with a high temperature rise effect in the cylinder is high like a glow plug. Adopting a delay shortening means, and reducing the ignition delay by other means such as control of the exhaust gas recirculated to the intake passage (hereinafter also referred to as EGR) and intake flow rate in the operating state where the prompt response to the release factor is low. As a result, the diesel engine after the automatic stop condition is canceled can be returned to the normal combustion control with the stable combustion characteristics while keeping the load for reducing the ignition delay to the minimum necessary.

  In a preferred aspect, the diesel engine includes a glow plug, and the ignition delay control means reduces the ignition delay when the quick stop request for the release factor is high when the automatic stop condition is canceled. As a means, when the prompt request for the release factor is low, the ignition delay shortening means other than the glow plug is driven and controlled. In this mode, when the automatic stop condition is canceled during the braking due to the establishment of the automatic stop condition, in the operating state where the quick response request for the release factor is high, the temperature rising effect in the cylinder is high, and the ignition delay is high. The glow plug is activated and the glow plug is stopped in an operating state where the prompt response to the release factor is low, so that the operation of the glow plug is kept to a minimum while ensuring the necessary responsiveness. be able to. The ignition delay reducing means other than the glow plug may be any means that can reduce the ignition delay, and various modes can be adopted.

  In a preferred aspect, the diesel engine includes an exhaust gas recirculation device that circulates the burned gas to the intake passage, and the ignition delay control means is configured to circulate the burned gas that circulates to the intake passage when the automatic stop condition is released. The exhaust gas recirculation device is driven and controlled so that the amount of gas increases. In this embodiment, the pressure and temperature in the cylinder are increased by EGR, and the ignition delay can be shortened by using the exhaust gas recirculation device as the ignition delay shortening means.

  In a preferred aspect, the diesel engine is provided with an intake shutter valve that adjusts an intake flow amount, and the combustion control means is provided with a stop-time compression stroke cylinder that becomes a compression stroke when stopped during braking after the automatic stop condition is satisfied. The intake shutter valve is driven and controlled so as to stop at a predetermined bottom dead center side stop position than the piston of the stop expansion stroke cylinder, which is the expansion stroke when the piston is stopped, and the intake flow amount is limited. The ignition delay control means drives and controls the intake shutter valve so as to increase the intake air flow rate when the automatic stop condition is released. In this aspect, by reducing the intake air flow amount during braking, it is possible to stop the piston at the intended phase and stop the diesel engine in a state where it is easy to restart, and the automatic stop condition is released. In this case, since the pressure in the cylinder can be increased by increasing the intake air flow rate, the intake shutter valve is used as a means for shortening the ignition delay, and the diesel engine after the release of the automatic stop condition is quickly It is possible to return to combustion control.

  In a preferred embodiment that employs a glow plug, the diesel engine includes an intake shutter valve that adjusts the intake air flow rate and an exhaust gas recirculation device that circulates burnt gas to the intake passage, and the combustion control means includes the automatic stop. During braking after the condition is satisfied, the piston of the stop compression stroke cylinder that becomes the compression stroke at the time of stop is stopped at a predetermined bottom dead center stop position than the piston of the stop expansion stroke cylinder that becomes the expansion stroke at the time of stop. The ignition delay control means controls the intake air flow rate by driving the intake shutter valve, and the ignition delay control means performs intake air when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied. The intake shutter valve and the exhaust gas recirculation device are driven and controlled so that the flow rate is increased and the burned gas is circulated to the intake passage. In this aspect, by reducing the intake air flow amount during braking, it is possible to stop the piston at the intended phase and stop the diesel engine in a state where it is easy to restart, and the automatic stop condition is released. In this case, by increasing the intake air flow rate and circulating EGR in the intake passage, the pressure and temperature in the cylinder can be increased. Therefore, the intake shutter valve and the exhaust gas recirculation device can be used as a means for shortening the ignition delay. The diesel engine after the automatic stop condition is released can be quickly returned to normal combustion control. And in the driving | running state by which the immediate request | requirement request | requirement with respect to the said cancellation | release factor is requested | required, since a glow plug operate | moves with the increase in intake airflow volume or EGR, ignition delay can be shortened rapidly and ignition stability can be improved. In addition, since the glow plug is operated in parallel with the intake flow rate and EGR increase control, the ignition delay can be reduced in a very short time, resulting in a shorter glow plug operating time and improved durability. It is also possible to plan.

  In a preferred embodiment that employs a glow plug, the diesel engine includes an intake shutter valve that adjusts the intake air flow rate and an exhaust gas recirculation device that circulates burnt gas to the intake passage, and the combustion control means includes the automatic stop. During braking after the condition is satisfied, the piston of the stop compression stroke cylinder that becomes the compression stroke at the time of stop is stopped at a predetermined bottom dead center stop position than the piston of the stop expansion stroke cylinder that becomes the expansion stroke at the time of stop. The ignition delay control means is configured to control the release of the automatic stop condition when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied. When the quick response request for the factor is high, only the glow plug is driven and controlled, and when the quick response request for the release factor is low, the group is It is for the control drives the intake shutter valve and said exhaust gas recirculation system so as to reflux the burned gas into the intake passage with increasing while air circulation amount was stopped immediately. In this mode, when the automatic stop condition is canceled during braking after the automatic stop condition is established, the cylinder with a relatively small amount of air is heated by the glow plug in an operation state in which an immediate response request for the release factor is high. Therefore, the in-cylinder temperature can be increased rapidly, and the glow plug drive time can be shortened. On the other hand, the glow plug is stopped in the operating state where the prompt response to the release factor is low. The rate can be minimized and the life of the glow plug can be maintained.

  In a preferred aspect, when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied and the engine speed at the time of cancellation is equal to or lower than a predetermined value, the ignition delay control means controls the ignition delay. The combustion control means temporarily stops the diesel engine and then restarts the diesel engine. In this aspect, when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied, if the engine speed at the time of cancellation is equal to or lower than the predetermined value, it becomes difficult to reduce the ignition delay, and the engine stalls instead. Therefore, the engine is stopped once and then restarted to prevent engine stall.

  In a preferred aspect, the vehicle is provided with an intake pressure detecting means for detecting an intake pressure of the diesel engine and outputting the detected intake pressure to the operating state determination unit, and the combustion control means is configured to set the automatic stop condition during braking after the automatic stop condition is established. When released, the fuel injection control is executed after the intake pressure becomes equal to or higher than a predetermined pressure. In this aspect, after the automatic stop condition is canceled during braking after the automatic stop condition is satisfied, the combustion control of the diesel engine is executed in a state in which the ignitability in the cylinder is sufficiently ensured, and the engine is stopped due to misfire. Can be prevented and combustion stability can be improved.

  As described above, according to the present invention, when the automatic stop condition is canceled during braking due to the establishment of the automatic stop condition, in an operation state in which an immediate response request for the release factor is high, like a glow plug, In the operation state where the ignition delay shortening means with high temperature rise effect is adopted and the prompt response to the release factor is low, the ignition delay is shortened by other means such as EGR and intake flow control, so the ignition delay The fuel consumption can be improved by returning the diesel engine after the automatic stop condition is released to normal combustion control with quick and stable combustion characteristics while minimizing the load for shortening the engine. There is an effect.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a schematic configuration of a four-cycle diesel engine 10 according to the present invention. In the present embodiment, an example in which the engine 10 is mounted on a vehicle connected to a manual transmission is shown.

  Referring to FIG. 1, engine 10 has a cylinder head 11 and a cylinder block 12. The cylinder head 11 and the cylinder block 12 are provided with four cylinders 14A to 14D. Also, a piston 16 connected to the crankshaft 15 by a connecting rod (not shown) is fitted into each cylinder 14A to 14D. A cavity 16 a that defines the combustion chamber 17 together with the cylinder head 11 is formed in the piston 16. The pistons 16 provided in the cylinders 14A to 14D are configured to move up and down with the rotation of the crankshaft 15 with a predetermined phase difference. Here, in the engine 10 that is a four-cylinder four-cycle engine, each of the cylinders 14A to 14D performs a cycle including intake, compression, expansion, and exhaust strokes with a predetermined phase difference. Crank angle in order of No. cylinder (cylinder 14A in the example shown), No. 3 cylinder (cylinder 14C in the example shown), No. 4 cylinder (cylinder 14D in the example shown), and No. 2 cylinder (cylinder 14B in the example shown) The phase difference is 180 ° (180 ° CA).

  The cylinder head 11 is provided with a glow plug 18 for each of the cylinders 14A to 14D as in-cylinder temperature raising means disposed so that the plug tip faces the combustion chamber 17. The cylinder head 11 is provided with a fuel injection valve 19 for each of the cylinders 14A to 14D. The fuel injection valve 19 has a branch pipe 21 disposed for each of the cylinders 14A to 14D with respect to the common rail 20 that stores and distributes fuel in a high pressure state higher than the valve opening pressure (injection pressure) of the fuel injection valve 19. Are connected to each other. Each fuel injection valve 19 opens the fuel passage by electromagnetic force when energized to open the true valve of the injection nozzle by fuel pressure, and burns high-pressure fuel supplied from the common rail 20 from a plurality of injection holes at the tip of the injection nozzle. Direct injection is supplied into the cylinders 14 </ b> A to 14 </ b> D toward the cavity 16 a of the piston 16 that defines the chamber 17. In the present embodiment, a fuel pressure sensor SW <b> 1 for detecting fuel pressure is provided on the common rail 20. The fuel injection amount of the fuel injection valve 19 is controlled by the energization time. A common rail 20 that supplies fuel to the fuel injection valve 19 is connected to a fuel supply pump 23 via a high-pressure fuel supply pipe 22.

  The cylinder head 11 is provided with an intake port 24 and an exhaust port 25 that open toward the combustion chamber 17 in the upper part of the cylinders 14A to 14D. In addition, an intake valve 26 and an exhaust valve 27 are respectively provided at a connection portion between the ports 24 and 25 and the combustion chamber 17. An intake passage 28 and an exhaust passage 29 are connected to the intake port 24 and the exhaust port 25. The downstream side of the intake passage 28 is branched into branched intake passages 28a branched for each of the cylinders 14A to 14D, and the upstream ends of the branched intake passages 28a communicate with the surge tank 28b. A common intake passage 28c is provided on the upstream side of the surge tank 28b. Although schematically shown in FIG. 1, in this common intake passage 28c, an intake shutter valve 30 that can adjust the intake flow amount flowing into each cylinder 14A to 14D, an air flow sensor SW2 that detects the intake flow amount, An intake pressure sensor SW3 that detects the intake pressure Pina and an intake temperature sensor SW4 that detects the intake air temperature are provided. The intake shutter valve 30 is configured to be opened and closed by an actuator 30a. In the illustrated example, the intake shutter valve 30 is set so that air flows even in the fully closed state.

  The engine 10 is provided with an alternator 32 connected to the crankshaft 15 by a timing belt or the like. The alternator 32 includes a regulator circuit 33 that adjusts the amount of power generation by adjusting the output voltage by controlling the current of a field coil (not shown), and is controlled by the engine control unit 100 that is input to the regulator circuit 33. Based on the signal, control of the power generation amount corresponding to the electric load of the vehicle, the voltage of the on-vehicle battery, and the like is executed.

  The engine 10 is provided with a starter motor 34 for starting the engine 10. The starter motor 34 has a motor body 34a and a pinion gear 34b. The pinion gear 34b reciprocates on the output shaft of the motor body 34a in a state where relative rotation is impossible. The crankshaft 15 is provided with a ring gear 35 fixed to a flywheel (not shown) concentrically with respect to the center of rotation. When the engine 10 is restarted using the starter motor 34, the pinion gear 34b moves to a predetermined meshing position and meshes with a ring gear 35 fixed to the flywheel. 15 is driven to rotate.

  Further, the engine 10 is provided with two crank angle sensors SW5 and SW6 for detecting the rotation angle of the crankshaft 15, and the engine rotation speed is based on a detection signal (pulse signal) output from one crank angle sensor SW5. Ne is detected, and the rotation angle of the crankshaft 15 is detected on the basis of detection signals out of phase output from the crank angle sensors SW5 and SW6. Further, the engine 10 is operated by a water temperature sensor SW7 for detecting a coolant temperature, an accelerator opening sensor SW8 for detecting an accelerator opening corresponding to an operation amount of an accelerator pedal 36 of the vehicle, and an operation of a brake pedal 37 of the vehicle. A brake pedal sensor SW9 for detection is provided.

  The engine 10 is provided with an exhaust gas recirculation device 40. The exhaust gas recirculation device 40 includes an EGR passage 41 that circulates EGR from the exhaust passage 29 to the intake passage 28, and an EGR valve 42 provided in the middle of the EGR passage 41. The EGR valve 42 is controlled to be opened and closed by an engine control unit 100 described below.

  The operation of the engine 10 is controlled by the engine control unit 100.

  The engine control unit 100 is composed of a CPU, a memory, a counter timer group, an interface, and a microprocessor having a bus for connecting these units. Based on detection signals from input elements such as the sensors SW1 to SW9, the engine control unit 100 And a control signal for each actuator such as the fuel injection valve 19, the starter motor 34, or the glow plug 18 is output. For example, the fuel injection amount, injection timing, and ignition timing according to the operating conditions are calculated, and a control signal is output to the fuel injection valve 19 and the like. Further, the target opening of the intake shutter valve 30 is calculated according to the operating conditions, and a control signal is output to the actuator 30a of the intake shutter valve 30 so that the opening of the intake shutter valve 30 becomes the target opening. .

  The engine control unit 100 includes a driving state determination unit 101 that determines the driving state of the vehicle, a fuel injection control unit 102 that controls fuel injection of the engine 10 based on the determination of the driving state determination unit 101, and a driving state determination unit 101. And the starter motor 34 of the engine 10 when the restart condition is satisfied based on the determination of the operating state determination unit 101. A starter control unit 104, a glow plug control unit 105 that controls the glow plug 18, and an EGR control unit 106 that drives and controls the exhaust gas recirculation device 40 are logically configured. Among these, the fuel injection control unit 102 and the intake air flow rate control unit 103 constitute combustion control means in the present embodiment. Further, the intake air flow rate control unit 103, the glow plug control unit 105, and the EGR control unit 106 constitute an ignition delay control means in the present embodiment.

  The driving state determination unit 101 includes a fuel pressure sensor SW1, an airflow sensor SW2, an intake pressure sensor SW3, an intake air temperature sensor SW4, a crank angle sensor SW5, SW6, a water temperature sensor SW7, an accelerator opening sensor SW8, a brake pedal sensor SW9, and the like. Based on the sensor signal, various operating states such as establishment or cancellation of the automatic stop condition or restart condition of the engine 10, fuel pressure, stop position of the piston 16, in-cylinder temperature, or whether the engine 10 is rotating forward, etc. Is a module for determining The operation state determination unit 101 determines the stop position of the piston 16 when the engine 10 is automatically stopped, and sets an appropriate stop position SA at which the piston 16 should stop. In the present embodiment, the appropriate stop position SA of the compression stroke cylinder at the time of stop is set by default in a range from 120 ° CA before compression top dead center to 100 ° CA before compression top dead center. As will be described later, in a diesel engine, it is necessary to inject fuel into the compression stroke cylinder at the time of stop, and to drive the piston 16 by the starter motor 34 so that the air-fuel mixture is self-ignited in the cylinder into which the fuel has been injected. Therefore, it is preferable that the piston 16 is stopped on the bottom dead center side. On the other hand, when the piston 16 is in the vicinity of the bottom dead center, the drive time of the starter motor 34 becomes long. Therefore, in order to achieve both reliable self-ignition and shortening of the drive time of the starter motor, by default, compression top dead It is set in a range from 120 ° CA before the point to 100 ° CA before the compression top dead center. However, when the in-cylinder temperature is high, the effective compression ratio of the stop compression stroke cylinder can be set small, so that the appropriate stop position SA is corrected to the top dead center side by the in-cylinder temperature. ing. The in-cylinder temperature is configured to be estimated based on data stored in advance in a memory. In the present embodiment, the driving state determination unit 101 receives a detection signal from a sensor (not shown) so as to be able to determine ON / OFF of the brake pedal 37 of the vehicle, vehicle speed, and the like.

  The fuel injection control unit 102 sets the fuel injection amount corresponding to the appropriate air-fuel ratio of the engine 10 and the fuel injection timing based on the determination of the operation state determination unit 101, and based on the setting, the fuel injection valve 19 Is a module for controlling the driving of

  The intake air flow rate control unit 103 is a module that sets an appropriate intake air flow rate of the engine 10 based on the determination of the operation state determination unit 101 and drives and controls the intake shutter valve 30 based on the setting.

  The starter control unit 104 is a module that outputs a control signal to the starter motor 34 when the engine 10 is started to drive the starter motor 34.

  The glow plug control unit 105 is a module that controls driving of the glow plug 18 during warm-up.

  The EGR control unit 106 achieves combustion stability by opening the EGR valve 42 in a predetermined partial load operation region.

The intake air flow rate control unit 103, the glow plug control unit 105, and the EGR control unit 106 as ignition delay control means have different characteristics for reducing the ignition delay τ _id of the glow plug 18, the intake shutter valve 30, and the exhaust gas recirculation device 40. This is used as a plurality of ignition delay shortening means, and selectively controls the ignition delay τ _id of the engine 10.

The ignition delay τ _id of a diesel engine is basically the Arrhenius equation

Is known to follow. Therefore, if the elements related to A, P, n, and E _A in the equation (1) are used as parameters according to the operating state, the ignition delay τ _id of the engine 10 is basically shortened, and the ignitability and combustion stability are reduced. It becomes possible to improve. Therefore, in the present embodiment, the intake air flow rate control unit 103, the glow plug control unit 105, and the EGR control unit 106 serving as ignition delay control means make the glow plug 18, the intake shutter valve 30, and the exhaust gas recirculation device 40 have a plurality of characteristics different from each other. It is used as a means for shortening the ignition delay to improve ignitability and combustion stability.

Here, as one of the operation states in which the ignition delay τ _id is required to be shortened, the automatic stop condition may be canceled when the engine 10 is braked due to the establishment of the automatic stop condition of the engine 10. . In that case, when the ignitability is improved by driving the glow plug 18, the drive frequency of the glow plug 18 is considerably increased, so that the deterioration of the glow plug 18 is accelerated. Therefore, in the present embodiment, as will be described in detail later, when the automatic stop condition is released, in an operating state where a quick response request for the release factor is high, the glow plug 18 is driven and controlled as an ignition delay reduction means, and the release is performed. In the operating state where the prompt response to the factor is low, the ignition delay shortening means (intake shutter valve 30, exhaust recirculation device 40, etc.) other than the glow plug 18 is driven and controlled.

  Next, control examples of the automatic stop control and restart control of the engine 10 will be described.

  FIG. 2 is a flowchart centering on the automatic stop control according to the present embodiment, and FIG. 3 is a timing chart showing the transition of the engine speed Ne based on the control example of FIG.

  Referring to FIG. 2, engine control unit 100 waits for a preset automatic engine stop condition to be satisfied (step S10). Specifically, when the operating state of the brake pedal 37 continues for a predetermined time and the vehicle speed is equal to or lower than a predetermined value, it is determined that the automatic stop condition of the engine 10 is satisfied.

  If it is determined in step S10 that the automatic stop condition is satisfied, engine speed adjustment control including alternator control is started (step S11). Specifically, it waits for the engine rotation speed Ne to be adjusted to a predetermined first rotation speed N1 (for example, 850 rpm) (step S12). The fuel supply from the fuel injection valve 19 is stopped at the timing t1 when the engine rotation speed Ne becomes the first rotation speed N1 (YES timing in step S12) (step S14). At this timing t1, the engine control unit 100 fully closes the intake shutter valve 30 (step S15). By this control, it is possible to increase the probability that the piston 16 stops at the appropriate stop position SA.

  That is, the stop position of the piston 16 is substantially determined by the balance between the air amount in the stop expansion stroke cylinder immediately before the engine 10 is completely stopped and the air amount in the stop compression stroke cylinder. Therefore, in order to stop the piston 16 in the proper stop position SA in the diesel engine, first, the intake flow amount of the stop expansion stroke cylinder and the stop compression stroke cylinder is temporarily reduced, and then the stop compression stroke cylinder is sufficient. Therefore, it is necessary to adjust the air amount for both cylinders so that the air amount is larger than the air amount in the stop expansion stroke cylinder. Therefore, in this embodiment, the intake pressure is reduced by fully closing the intake shutter valve 30 at the timing t1, and the air amount of the stop expansion stroke cylinder and the stop compression stroke cylinder is reduced.

  When the fuel injection is stopped at the timing t1, the cylinders 14A to 14D repeat the intake, compression, expansion, and exhaust cycles with a very small intake flow amount, and the kinetic energy of the crankshaft 15 and the like is generated by friction resistance. When the engine 10 is consumed by pumping work of each cylinder 14A to 14D, the engine 10 descends with undulations, and the 4-cylinder 4-cycle engine reaches about 10 compression top dead centers. Stop later. In this process, the timing at which any one of the cylinders 14A to 14D exceeds the compression top dead center coincides with the timing at which the engine speed Ne undulates.

  Therefore, in the present embodiment, after the intake shutter valve 30 is fully closed at the timing t1, the engine control unit 100 causes the engine rotation speed Ne to become lower than a predetermined second rotation speed N2 (for example, about 400 rpm). (Step S16). The second rotational speed N2 coincides with the timing at which the piston 16 of the stop-time compression stroke cylinder reaches the top dead center from the expansion stroke to the intake stroke.

  If YES in step S16, engine control unit 100 opens intake shutter valve 30 (step S17). As a result of this valve opening operation, the intake valve 26 and the exhaust valve 27 are closed with a small amount of air in the stop expansion stroke cylinder and shifted to the compression stroke, whereas the intake valve 26 is opened in the stop compression stroke cylinder. As a result, a relatively large amount of fresh air is sucked into the cylinder. As a result, the amount of air in the stop compression stroke cylinder is larger than that in the stop expansion stroke cylinder.

  After that, the engine control unit 100 continues the alternator control and continues to adjust the stop position of the piston 16, and waits for the engine 10 to completely stop based on the detected values of the crank angle sensors SW5 and SW6 (step S18). ). If the engine 10 has completely stopped, the engine speed adjustment control is terminated (step S19).

  At the timing when the engine 10 is completely stopped, the piston 16 of the stop-time compression stroke cylinder passes through the bottom dead center of the intake stroke and shifts to the compression stroke. At this timing, since the intake valve 26 and the exhaust valve 27 are substantially closed, a large amount of air sucked into the cylinder is compressed by the piston 16 with the bottom dead center added. On the other hand, in the stop-time expansion stroke cylinder, the piston 16 compressed in the cylinder having a relatively small amount of air passes through the compression top dead center and shifts to the expansion stroke. For this reason, in the compression stroke cylinder at the time of stop, it will be stopped on the relatively bottom dead center side by the compression reaction force in the cylinder. Therefore, the piston of the stop-time compression stroke cylinder is appropriately set by appropriately setting the second rotational speed N2 and the intake air flow amount at the timing t2 when the second rotational speed N2 is detected by experiments or the like. 16 can be stopped at a predetermined bottom dead center side stop position (in this embodiment, from 100 ° CA before compression top dead center to 120 ° CA before compression top dead center).

  When the engine 10 is completely stopped, the engine control unit 100 stores the stop position of the piston 16 determined by the operation state determination unit 101 based on detection of the crank angle sensors SW5 and SW6 (step S20).

  Next, engine restart will be described with reference to FIG. FIG. 4 is a flowchart centering on restart control according to the present embodiment.

  After the engine 10 stops, the engine control unit 100 measures the stop time and integrates it (step S21). Since the temperature in the cylinder depends on the stop time of the engine 10, in the present embodiment, the engine control unit 100 is provided with data in which the relationship between the stop time and the temperature is previously mapped, and is based on the stop time. Therefore, the in-cylinder temperature is estimated.

  Next, the operating state determination unit 101 of the engine control unit 100 is based on the intake air temperature detected by the intake air temperature sensor SW4, the coolant temperature detected by the water temperature sensor SW7, the stop time of the engine 10, and the drive time of the glow plug 18. Then, the in-cylinder temperature is calculated (step S22).

  Next, a target fuel pressure is determined from the calculated in-cylinder temperature, and an appropriate stop position SA is set from the fuel pressure (step S23). In the present embodiment, since the appropriate stop position SA is set based on the in-cylinder temperature and the target fuel pressure, a more suitable stop position determination can be performed.

  Next, the engine control unit 100 determines whether or not the piston 16 of the stop-time compression stroke cylinder is on the top dead center side with respect to the appropriate stop position SA (step S24). If it is on the top dead center side, the glow plug 18 is driven (step S25), and the inside of the cylinder is heated. If it is within the proper stop position SA, the glow plug 18 is stopped (step S26).

  Next, the engine control unit 100 determines whether or not a restart condition is satisfied (step S27). The restart condition includes that the accelerator pedal 36 is depressed, that the automatic stop condition is released after the engine 10 is stopped, and the like.

  If the restart condition is not satisfied, the engine control unit returns to step S21 and repeats the process. For this reason, the appropriate stop position SA set in step S23 also changes with changes in measurement time and in-cylinder temperature.

  On the other hand, if the restart condition is satisfied in step S27, the starter control unit 104 of the engine control unit 100 drives the starter motor 34 (step S28). Thereby, in the compression stroke cylinder at the time of stop, piston 16 moves to a top dead center, compressing the air in a cylinder.

  Next, the fuel injection control unit 102 of the engine control unit 100 determines whether or not the piston 16 of the stop-time compression stroke cylinder is on the top dead center side with respect to the appropriate stop position SA (step S29). If the engine is on the top dead center side, the engine control unit 100 waits for the stop-time intake stroke cylinder to reach the compression stroke, and injects fuel at a predetermined timing after the stop-time intake stroke cylinder reaches the compression stroke. (Step S30). That is, when the piston stop position deviates from the proper stop position SA, the combustion in the stop compression stroke cylinder is stopped. On the other hand, when the piston stop position is within the proper stop position SA, fuel is injected into the compression stroke cylinder at the time of stop, and the engine 10 is restarted by combustion in this cylinder (step S31).

  After step S30 or step S31, the engine control unit 100 shifts to normal operation (step S32) and ends the process.

  In the control mode as described above, an example of interrupt control when the automatic stop condition is canceled during braking due to the establishment of the automatic stop condition will be described with reference to FIG.

  FIG. 5 is a flowchart showing an example of interrupt control according to the present embodiment.

  As shown in the figure, the engine control unit 100 monitors the release of the automatic stop condition while the engine 10 is braked by the establishment of the automatic stop condition (step S40). This automatic stop condition is canceled when the driver depresses the accelerator pedal 36, when the clutch pedal is OFF at the time of gear-in, or when an on-vehicle auxiliary machine (for example, an air conditioner) is operated to reduce power consumption. For example, the battery capacity increases (SOC) or decreases to a predetermined value or less.

  When the automatic stop condition is canceled, the engine control unit 100 determines whether or not the engine rotational speed Ne exceeds the second rotational speed N2 (step S41). If the engine rotational speed Ne is equal to or lower than the second rotational speed N2, the engine 10 has already reached the final stage of braking control (see FIGS. 2 and 3). Therefore, when the engine rotational speed Ne is equal to or lower than the second rotational speed N2, the engine control unit 100 determines whether or not the intake shutter valve 30 is closed (step S42). After opening 30 (step S43), if it is open, the process proceeds to step S18. As a result, the engine 10 is automatically stopped once by the control after step S18 in FIG. 2, and then the restart condition is established by the determination in step S27 shown in FIG. As a result, the engine 10 is restarted promptly.

On the other hand, if the engine speed Ne when the automatic stop condition is released is sufficiently high in step S41 of FIG. 5, the engine control unit 100 fully opens the intake shutter valve 30 (step S43), and the charging amount is increased rapidly. At the same time, the EGR valve 42 of the exhaust gas recirculation device 40 is opened (step S44). By this control, the filling amount of the cylinder 14A (˜14D) that has reached the intake stroke is increased, and the in-cylinder temperature is also increased by EGR. As a result, the ignition delay τ _id in the cylinder can be shortened.

In this state, the engine control unit 100 determines whether or not the canceling factor of the automatic stop condition requires an immediate response request (steps S45 and S46). That is, when the driver depresses the accelerator pedal 36 (step S45), or when the gear is in and the clutch pedal is OFF (step S46), the driver is requesting acceleration, so the release factor Is determined to be high, and the glow plug 18 is turned on (step S47). On the other hand, when the automatic stop condition is canceled due to a factor not corresponding to any of these (in the case of NO in step S46), the intake pressure Pina in the intake passage 28 (intake manifold) is read from the output of the intake pressure sensor SW3, It waits for the pressure to rise above the predetermined pressure Pst (step S48). In other words, so that the activation energy E _A in the cylinder to wait for increased sufficiently, based on the intake pressure Pina.

  After executing step S47 or when the intake pressure Pina rises above the predetermined pressure Pst in step S48, the engine control unit 100 determines whether or not the starter motor 34 needs to be driven (step S49) and needs to be driven. For example, the process proceeds to step S28 shown in FIG. 4 and if driving is unnecessary, the process proceeds to step S29 shown in FIG. 4 to execute the combustion control, and then the control of step S30 or step S31 is performed to perform step S32. Transition to normal operation.

  As described above, in the present embodiment, when the automatic stop condition is satisfied, the piston 16 is stopped at a suitable position for restarting the engine 10, and the subsequent startability can be improved. That is, in a diesel engine, it is necessary to inject fuel into the stop-time compression stroke cylinder to cause the fuel mixture to self-ignite, so the piston 16 of the stop-time compression stroke cylinder stops as close to the bottom dead center as possible. It is preferable. In response to such a request, in the present embodiment, after the fuel injection is stopped, the intake flow amount is limited, and the timing at which the second rotational speed N2 at which the stop-time compression stroke cylinder is predicted to shift to the last intake stroke is detected. Since the intake flow amount is increased at t2, the amount of air taken into the stop compression stroke cylinder is larger than that in the stop expansion stroke cylinder. As a result, in the stop-time compression stroke cylinder, a predetermined bottom dead center side stop position (from 100 ° CA before top dead center to 120 ° before top dead center) due to the compression reaction force of a relatively large amount of air filled in the cylinder. CA), and at the time of restart, a sufficient effective compression ratio for self-ignition can be secured.

  In the present embodiment, the bottom dead center side stop position is from 120 ° CA before top dead center to 100 ° CA before top dead center. For this reason, in the present embodiment, the engine 10 can be restarted by optimizing the driving time of the starter motor 34 and the effective compression ratio of the stop-time compression stroke cylinder for self-ignition. That is, in the engine 10, it is preferable that the piston 16 of the compression stroke cylinder at the time of stop is stopped as close as possible to the bottom dead center, but the piston 16 is stopped too much on the bottom dead center side. In such a case, the drive time of the starter motor 34 becomes long, which is not preferable. Therefore, by reducing the predetermined bottom dead center side stop position from 120 ° CA before top dead center to 100 ° CA before top dead center, the drive time of the starter motor 34 is shortened and the compression stroke cylinder at the time of stop is surely achieved. Both self-ignition and compatibility can be improved.

  In this embodiment, the engine control unit 100 determines whether or not the piston 16 of the stop-time compression stroke cylinder has stopped at a predetermined appropriate stop position SA. When the piston 16 of the hour compression stroke cylinder is at the proper stop position SA, the first fuel is injected into the compression stroke cylinder at the time of stop, and when it is out of the top dead center side from the appropriate position, when the stop is in the intake stroke at the time of stop The first fuel is injected into the intake stroke cylinder. For this reason, in this embodiment, when the piston 16 of the stop compression stroke cylinder is in the proper position, fuel is injected in the stop compression stroke and the starter motor 34 is driven, so that the fuel is stopped in the stop compression stroke cylinder. The air-fuel mixture is ignited and the engine 10 is restarted. Further, when the piston 16 is deviated from the proper position to the top dead center side, the fuel injection to the compression stroke cylinder at the time of stop is stopped and the fuel is injected to the intake stroke cylinder at the time of stop. However, the fuel mixture is surely self-ignited with a sufficient effective compression ratio, and restartability can be ensured.

  Further, in this embodiment, the glow plug control unit 105 that controls the glow plug 18 of the engine 10 is configured so that the glow plug when the piston 16 of the compression stroke cylinder at the time of stop is disengaged from the proper stop position SA to the top dead center side. The engine control unit 100 corrects the appropriate stop position SA to the top dead center side in accordance with the in-cylinder temperature of the compression stroke cylinder at the time of stop. For this reason, in this embodiment, even when the piston 16 of the compression stroke cylinder at the time of stoppage is shifted from the proper stop position SA to the top dead center side, the startability can be improved as much as possible. That is, since the delay of self-ignition has a characteristic that depends on the temperature in the cylinder, by increasing the temperature in the cylinder, the shortage of the compression degree can be compensated and the startability can be improved. In addition, since the appropriate stop position SA can be shifted to the top dead center side, the engine 10 can be restarted by self-ignition in the compression stroke cylinder at the time of stop, so that the drive time of the starter motor 34 is also possible. As much as possible.

Further, in the present embodiment, when the automatic stop condition is canceled during the automatic stop control of the engine 10, the ignition delay control means that selectively drives and controls the plurality of ignition delay shortening means is provided, and the ignition delay control means is In the case where the automatic stop condition is canceled, when the quick response request for the canceling factor is high, the one having a high temperature rise effect in the cylinder is selected from the plurality of ignition delay shortening means. For this reason, in the present embodiment, when the automatic stop condition is released during braking due to the establishment of the automatic stop condition, an immediate response request is determined, and in an operation state where the immediate response request for the release factor is high, like the glow plug 18, Use ignition delay shortening means with high temperature rise effect in the cylinder, and shorten the ignition delay τ _id by other means such as EGR and control of intake air flow in the operation state where the prompt response to the release factor is low Thus, the engine 10 after canceling the automatic stop condition is quickly returned to the normal combustion control with stable combustion characteristics while keeping the load for reducing the ignition delay τ _id to the minimum necessary.

Further, in this embodiment, the engine 10 includes the glow plug 18, and the ignition delay control means reduces the ignition delay when the quick stop request is high when the automatic stop condition is cancelled. As a means, when the prompt response to the release factor is low, the ignition delay shortening means other than the glow plug 18 is drive-controlled. For this reason, in this embodiment, when the automatic stop condition is canceled during braking due to the establishment of the automatic stop condition, in the operating state where the quick response request for the release factor is high, the temperature rising effect in the cylinder is high, and the ignition delay τ _The glow plug 18 that is highly effective in shortening the _id is driven, and the glow plug 18 is stopped in an operation state in which the prompt response to the release factor is low, so that the glow plug 18 is secured while ensuring necessary responsiveness. Can be kept to the minimum necessary.

Further, in the present embodiment, the engine 10 includes the exhaust gas recirculation device 40 that circulates the burned gas to the intake passage, and the ignition delay control means performs the burned gas that circulates to the intake passage when the automatic stop condition is released. The exhaust gas recirculation device 40 is driven and controlled so that the amount increases. For this reason, in the present embodiment, the pressure and temperature in the cylinder are increased by EGR, and the ignition delay τ _id can be shortened by using the exhaust gas recirculation device 40 as the ignition delay shortening means.

  Further, in the present embodiment, the engine 10 includes the intake shutter valve 30 that adjusts the intake flow amount, and the intake flow amount control unit 103 determines that the piston 16 of the stop-time compression stroke cylinder is in a braking state after the automatic stop condition is satisfied. The intake shutter valve 30 is driven and controlled so as to stop at a predetermined bottom dead center stop position with respect to the piston 16 of the stop expansion stroke cylinder that becomes the expansion stroke at the time of stop. The delay control means drives and controls the intake shutter valve 30 so as to increase the intake flow amount when the automatic stop condition is released. For this reason, in the present embodiment, by reducing the intake flow amount during braking, the piston 16 can be stopped at the intended phase, and the engine 10 can be stopped in a state where it can be easily restarted. Since the pressure in the cylinder can be increased by increasing the amount of intake air flow, the intake shutter valve 30 is used as a means for shortening the ignition delay so that the automatic stop condition can be quickly released. The engine 10 can be returned to normal combustion control.

Further, in the present embodiment, the engine 10 includes an intake shutter valve 30 that adjusts the intake air flow rate, and an exhaust gas recirculation device 40 that circulates the burned gas to the intake passage, and the intake air flow rate control unit 103 has an automatic stop condition. During the braking after the establishment, the intake shutter valve 30 is set so that the piston 16 of the stop compression stroke cylinder stops at a predetermined bottom dead center stop position with respect to the piston 16 of the stop expansion stroke cylinder which becomes the expansion stroke when stopped. The ignition delay control means increases the intake flow rate and burns when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied. The intake shutter valve 30 and the exhaust gas recirculation device 40 are driven and controlled so as to circulate the gas in the intake passage. For this reason, in the present embodiment, by reducing the intake flow amount during braking, the piston 16 can be stopped at the intended phase, and the engine 10 can be stopped in a state where it can be easily restarted. When is released, the intake air flow rate is increased and the EGR is circulated through the intake passage, so that the pressure and temperature in the cylinder can be increased. Therefore, the intake shutter valve 30 and the exhaust gas recirculation device 40 are ignited. It can be used as a delay shortening means, and the engine 10 after the automatic stop condition is released can be quickly returned to normal combustion control. In an operating state where an immediate response request for the release factor is required, the glow plug 18 operates as the intake air flow rate or EGR increases, so that the ignition delay τ _id can be quickly reduced and the ignition stability can be improved. . In addition, since the glow plug 18 is operated in parallel with the intake flow rate and EGR increase control, the ignition delay τ _id can be shortened in a very short period of time. It is also possible to improve durability.

In the present embodiment, when the automatic stop condition during braking after establishment automatic stop condition is canceled, when the engine rotational speed at release is less than a predetermined value, the ignition delay control means, the ignition delay tau _id While stopping the control, the fuel injection control unit 102 and the intake air flow rate control unit 103 temporarily stop the engine 10 and then restart it. For this reason, in this embodiment, when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied, if the engine speed at the time of cancellation is equal to or less than a predetermined value, it becomes difficult to shorten the ignition delay τ _id. On the other hand, it is easy to bring the engine stall. Therefore, the engine 10 is temporarily stopped and then restarted to prevent engine stall.

  Further, in the present embodiment, the fuel injection control unit 102 and the intake air flow rate control unit 103 are configured such that the intake pressure Pina becomes equal to or higher than the predetermined pressure Pst when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied. The fuel injection control is executed later. For this reason, in the present embodiment, the combustion control of the engine 10 is executed in a state where the ignitability in the cylinder is sufficiently secured after the automatic stop condition is canceled during braking after the automatic stop condition is established, The engine stall due to misfire can be prevented and the combustion stability can be improved.

  The above-described embodiments are merely examples of preferred specific examples of the present invention, and the present invention is not limited to the above-described embodiments.

  For example, in the flowchart shown in FIG. 4, the control of the in-cylinder temperature by the glow plug (steps S24 to S26) may be omitted. In that case, it is not necessary to consider the drive time of the glow plug 18 in calculating the in-cylinder temperature in step S22.

  It is also possible to adopt the flowchart shown in FIG.

  FIG. 6 is a flowchart showing an example of interrupt control according to another embodiment of the present invention.

  In the interrupt control shown in FIG. 6, when the engine speed Ne is equal to or higher than the second rotational speed N2 in the determination in step S41, first, the determination in step S45 and step S46 is executed. In the determination in step S46, When it is determined that the request for canceling the automatic stop condition does not require an immediate response request, the intake shutter valve 30 is fully opened (step S43), and the exhaust gas recirculation passage 41 is opened (step S44).

  In this specification, the engine 10 includes an intake shutter valve 30 that adjusts the intake air flow rate, and an exhaust gas recirculation device 40 that circulates the burned gas to the intake passage, and includes a fuel injection control unit 102 and an intake flow rate control unit 103. During the braking after the automatic stop condition is established, the piston 16 of the stop compression stroke cylinder stops at a predetermined bottom dead center side stop position with respect to the piston 16 of the stop expansion stroke cylinder which becomes the expansion stroke when stopped. The intake delay valve 30 is controlled by driving the intake shutter valve 30 of the engine 10, and the ignition delay control means cancels the automatic stop condition when the automatic stop condition is canceled during braking after the automatic stop condition is established. When the prompt response to the factor is high, only the glow plug 18 is driven and controlled. When the prompt response to the release factor is low, the glow plug 18 is stopped. In which it drives and controls the intake air shutter valve 30 and the exhaust gas recirculation system 40 to reflux in an intake passage of the combustion gases with increasing intake air flow amount. In the embodiment shown in FIG. 6, when the automatic stop condition is canceled during braking after the automatic stop condition is established, the cylinder with a relatively small amount of air is used by the glow plug 18 in an operation state in which an immediate response request for the release factor is high. Since the inside is heated, the in-cylinder temperature can be raised rapidly, and the drive time of the glow plug 18 can be shortened. On the other hand, in the operating state where the quick response request for the release factor is low, the glow plug 18 is stopped. Therefore, the operating rate of the glow plug 18 can be suppressed to the minimum necessary, and the lifetime of the glow plug 18 can be maintained.

  It goes without saying that various modifications can be made within the scope of the claims of the present invention.

1 shows a schematic configuration of a four-cycle diesel engine according to the present invention. It is a flowchart centering on the automatic stop control which concerns on this embodiment. It is a timing chart which shows transition of engine speed based on the example of control of Drawing 2. It is a flowchart centering on restart control which concerns on this embodiment. It is a flowchart which shows the example of interruption control which concerns on embodiment of this invention. It is a flowchart which shows the example of interruption control which concerns on another embodiment of this invention.

Explanation of symbols

10 Diesel engine 14A-14D Cylinder 16 Piston 18 Glow plug (an example of in-cylinder temperature raising means, ignition delay shortening means)
19 Fuel injection valve 28 Intake passage 30 Intake shutter valve (an example of ignition delay reducing means)
34 Starter motor 40 Exhaust gas recirculation device (an example of ignition delay shortening means)
DESCRIPTION OF SYMBOLS 100 Engine control unit 101 Operation state determination part 102 Fuel injection control part (an example of a combustion control means)
103 Intake flow control unit (an example of combustion control means and ignition delay control means)
104 Starter control unit 105 Glow plug control unit (an example of ignition delay control means)
106 EGR control unit (an example of ignition delay control means)
SW1 Fuel pressure sensor SW2 Airflow sensor SW3 Intake pressure sensor SW4 Intake temperature sensor SW5, SW6 Crank angle sensor SW7 Water temperature sensor SW8 Accelerator opening sensor SW9 Brake pedal sensor

Claims (8)

In the diesel engine control device that automatically stops the diesel engine when a predetermined automatic stop condition is satisfied, and automatically restarts the diesel engine after the automatic stop when the predetermined restart condition is satisfied,
An operation state determination unit having at least a function of determining success or failure of the automatic stop condition and the restart condition, and determining an operation state of a vehicle equipped with the diesel engine;
Combustion control means for controlling the combustion of the diesel engine based on the determination of the operating state determination unit;
A plurality of ignition delay reducing means having different characteristics for reducing the ignition delay of the diesel engine;
An ignition delay control means for selectively driving and controlling the ignition delay shortening means when the automatic stop condition is canceled during the automatic stop control of the diesel engine,
The ignition delay control means selects the ignition delay shortening means having a high temperature rise effect in the cylinder when the immediate stop request is high when the automatic stop condition is cancelled. A control device for a diesel engine, characterized in that The control device for a diesel engine according to claim 1,
The diesel engine includes a glow plug,
The ignition delay control means controls driving of the glow plug as an ignition delay shortening means when the automatic stop condition is released and the quick response request for the release factor is high, and the quick response request for the release factor is low. The control device for the diesel engine, characterized in that when the ignition delay reducing means other than the glow plug is driven and controlled. In the control apparatus of the diesel engine of Claim 1 or 2,
The diesel engine includes an exhaust gas recirculation device that circulates burned gas to the intake passage,
The ignition delay control means drives and controls the exhaust gas recirculation device so that the amount of burned gas circulating in the intake passage increases when the automatic stop condition is released. Control device. The diesel engine control device according to any one of claims 1 to 3,
The diesel engine includes an intake shutter valve that adjusts the intake air flow rate,
During the braking after the automatic stop condition is satisfied, the combustion control means has a predetermined lower dead than the piston of the stop-time expansion stroke cylinder in which the stop-stroke compression stroke cylinder becomes the compression stroke at the time of stoppage. In order to stop at the point side stop position, the intake shutter valve is driven and controlled to limit the intake flow amount,
The control device for a diesel engine, wherein the ignition delay control means is configured to drive and control the intake shutter valve so as to increase an intake air flow rate when the automatic stop condition is canceled. The control device for a diesel engine according to claim 2,
The diesel engine includes an intake shutter valve that adjusts the intake air flow rate, and an exhaust gas recirculation device that circulates the burned gas to the intake passage.
During the braking after the automatic stop condition is satisfied, the combustion control means has a predetermined lower dead than the piston of the stop-time expansion stroke cylinder in which the stop-stroke compression stroke cylinder becomes the compression stroke at the time of stoppage. In order to stop at the point side stop position, the intake shutter valve is driven and controlled to limit the intake flow amount,
When the automatic stop condition is canceled during braking after the automatic stop condition is satisfied, the ignition delay control means increases the intake air circulation amount and recirculates the burned gas to the intake passage. A control device for a diesel engine, which controls driving of a shutter valve and the exhaust gas recirculation device. The control device for a diesel engine according to claim 2,
The diesel engine includes an intake shutter valve that adjusts the intake air flow rate, and an exhaust gas recirculation device that circulates the burned gas to the intake passage.
During the braking after the automatic stop condition is satisfied, the combustion control means has a predetermined lower dead than the piston of the stop-time expansion stroke cylinder in which the piston of the stop-time compression stroke that becomes the compression stroke at the time of stop becomes the expansion stroke at the time of stop. In order to stop at the point side stop position, the intake shutter valve is drive-controlled to limit the intake flow amount,
When the automatic stop condition is canceled during braking after the automatic stop condition is established and the quick response request for the release factor is high, the ignition delay control means controls and drives only the glow plug, When the prompt response to the release factor is low, drive control of the intake shutter valve and the exhaust gas recirculation device is performed so that the intake air flow rate is increased while the glow plug is stopped and the burned gas is circulated to the intake passage. A control device for a diesel engine, characterized in that The diesel engine control device according to any one of claims 4 to 6,
When the automatic stop condition is canceled during braking after the automatic stop condition is satisfied, and the engine speed at the time of cancellation is equal to or lower than a predetermined value, the ignition delay control means pauses the ignition delay control and The combustion control means is for temporarily stopping the diesel engine and then restarting the diesel engine. In the control apparatus of the diesel engine in any one of Claim 1 to 7,
Intake pressure detection means for detecting the intake pressure of the diesel engine and outputting it to the operating state determination unit,
The combustion control means performs fuel injection control after the intake pressure becomes equal to or higher than a predetermined pressure when the automatic stop condition is canceled during braking after the automatic stop condition is satisfied. Diesel engine control device.

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