JP5195240B2 - Engine control device - Google Patents

Description

  The present invention controls the output voltage of the generator of the engine so as to promote the charging of the battery during the deceleration fuel cut operation and to suppress the charging of the battery during the non-deceleration fuel cut operation, and to take in the air according to the engine operating state. The present invention relates to an engine control device configured to control valve opening / closing timing.

  In general, when the vehicle is running, when the accelerator is released or the amount of depression of the accelerator is suddenly reduced and the vehicle is in a decelerating state, the engine basically does not need to generate torque. Therefore, in such a deceleration state, an engine in which fuel supply is temporarily stopped, that is, deceleration fuel cut is performed to prevent unnecessary fuel consumption and improve fuel efficiency is widely used. Further, when such a deceleration fuel cut is performed, the throttle valve is closed or the throttle opening is very small, so that the pumping loss increases, and the transmission mechanically connects the engine and the drive wheels. When in the state, the engine braking force acts.

However, when the engine braking force acts in this way, the mechanical energy of the engine or the automobile is lost, so that the fuel efficiency of the engine or the automobile is lowered. Therefore, at the time of deceleration fuel cut, the throttle valve is opened to reduce the pumping loss to reduce the engine braking force, while this increases the output of the generator using the mechanical energy that escapes the loss and regenerates the mechanical energy. An engine (internal combustion engine) adapted to perform the above has been proposed (for example, see Patent Document 1).
JP 2006-112433 A (paragraph [0030], FIG. 5)

  However, when regenerating the mechanical energy by increasing the output of the generator during the deceleration fuel cut operation as described above, if the driving load of the generator changes, the engine brake force resulting from the driving load of the generator is accompanied accordingly. Changes. For this reason, there is a problem that the engine braking force fluctuates due to fluctuations in the driving load of the generator, and sometimes the engine braking force becomes excessive and a torque shock occurs.

  When the throttle valve is opened to reduce the pumping loss during the deceleration fuel cut, a large amount of fuel combustion air is supplied to the intake passage during that time. For this reason, even if the throttle opening is reduced simultaneously with the end of the deceleration fuel cut, the amount of air temporarily supplied to the combustion chamber and thus the output torque of the engine increases due to the response delay, and a torque shock occurs when the fuel is restored. There is also a problem.

  The present invention has been made in order to solve the above-described conventional problems, and provides a torque shock at the time of fuel return to an engine that regenerates mechanical energy by increasing the output of a generator during a deceleration fuel cut operation. It is an object to be solved to provide an engine control device that can improve fuel efficiency while preventing or suppressing the occurrence of fuel.

An engine control apparatus according to the present invention, which has been made to solve the above problems, includes voltage control means and intake valve opening / closing timing control means. Voltage control means, the output voltage of the generator rotated by the engine, the deceleration while fuel during cutting operation is set to a high voltage level so as to facilitate the charging of Batterihe, Bas care not equal during deceleration fuel cut operation The low voltage level is set lower than the high voltage level so as to suppress charging. The intake valve opening / closing timing control means controls the opening / closing timing of the intake valve according to the operating state of the engine. Deceleration of the engine control device further, when the parameter value detection means for detecting a parameter value corresponding to the load of the engine due to driving of the generator, the load of the engine attributable to the drive of the generator is below a predetermined load Throttle control means for controlling the throttle valve to open during fuel cut operation. Here, the intake valve closing timing control means, during deceleration fuel cut operation when the load of the engine due to driving of the generator is below the predetermined load, the closing timing of the intake valves, less pumping loss intake air charging amount Is set to the middle stage of the compression process so that becomes larger .

In the engine control apparatus according to the present invention, the intake valves open and close timing control means, during deceleration fuel cut operation when the load of the engine due to driving of the generator exceeds a predetermined load, pumping the closing timing of the intake valve It is preferable to control so as to reduce the loss.

  The engine control apparatus according to the present invention preferably includes exhaust valve opening / closing timing control means for controlling the opening / closing timing of the exhaust valve in accordance with the operating state of the engine. In this case, when the intake valve closing timing is controlled so as to reduce the pumping loss, the intake valve exhaust timing and the exhaust valve opening timing are less than the expansion stroke. The crank angle from the bottom dead center is equal across the dead center, the intake valve opening timing is within the compression stroke, and the exhaust valve opening timing is within the expansion stroke. preferable.

According to the engine control apparatus according to the present invention, the load of the engine attributable to the drive of the generator when more than a predetermined load, i.e. in situations lightly loaded engine due to driving of the generator, the deceleration fuel cut-off operation during the The intake charge amount is reduced. In this case, since the engine braking force due to the engine load due to the drive of the generator is small, even if the pumping loss increases somewhat, an excessive engine braking force does not occur, and an appropriate engine braking can be obtained. For this reason, it is possible to prevent or suppress the occurrence of torque shock at the time of fuel return from the deceleration fuel cut operation.

Further, in the engine control apparatus according to the present invention, when the engine load caused by the drive of the generator exceeds a predetermined load, when the valve closing timing of the intake valve is controlled so as to reduce the pumping loss, Since the engine braking force resulting from the engine load resulting from driving increases to some extent, it is possible to obtain an appropriate engine braking force while reducing pumping loss. In this case, fuel efficiency can be improved by reducing pumping loss. In this case, if the pumping loss is increased, the engine braking force becomes excessive.

  Hereinafter, preferred embodiments of the present invention (best mode for carrying out the present invention) will be specifically described with reference to the accompanying drawings. In the automobile engine according to this embodiment, as will be described in detail later, when a predetermined fuel stop condition is satisfied, the fuel injection valve stops fuel injection and performs deceleration fuel cut. After a predetermined fuel return condition is established during execution, unnecessary fuel consumption is prevented by performing fuel return to improve the fuel efficiency of the engine or a vehicle equipped with the engine. Further, the output voltage of the generator is controlled so as to promote charging of the battery during the deceleration fuel cut operation and to suppress charging of the battery during the non-deceleration fuel cut operation.

  As shown in FIG. 1, the main body of a spark ignition engine E mounted on an automobile W is composed of a cylinder head 1 and a cylinder block 2. The engine E is a four-cylinder four-cycle engine and includes four cylinders 3 (only one cylinder is shown in FIG. 1). In this engine E, each cylinder 3 repeats a cycle composed of expansion, exhaust, intake, and compression strokes with a predetermined phase difference. These cycles include the first cylinder, the third cylinder, It is repeated with a phase difference of 180 ° (180 ° CA) in the crank angle in the order of the 4th cylinder and the 2nd cylinder.

  A piston 4 is fitted in each cylinder 3, and a combustion chamber 5 is formed above the piston 4. The piston 4 is connected to the crankshaft 7 via a connecting mechanism having a connecting rod 6 and the like. A spark plug 8 is provided at the top of the combustion chamber 5 of each cylinder 3, and the plug tip 8 a faces the combustion chamber 5. The spark plug 8 ignites and burns an air-fuel mixture that is a mixture of fuel and air injected from the fuel injection valve 9. As fuel for the engine E, gasoline, propane, methanol, or the like can be used.

  An intake port 10 and an exhaust port 11 are opened to the combustion chamber 5 of each cylinder 3, and an intake valve 12 and an exhaust valve 13 are provided in both the ports 10 and 11, respectively. The opening / closing timing of the intake valve 12 and the exhaust valve 13 of each cylinder 3 is set so that each cylinder 3 performs each cycle consisting of four strokes of expansion, exhaust, intake, and compression with a predetermined phase difference.

  Here, the intake valve 12 is opened and closed at a predetermined timing in synchronization with the crankshaft 7 by the intake valve cam 14. An intake valve opening / closing timing control mechanism 15 (VVT) is provided for the intake valve cam 14. The intake valve opening / closing timing control mechanism 15 advances the opening / closing timing of the intake valve 12 via the intake valve cam 14 in accordance with a control signal from an engine control unit 40 (hereinafter referred to as “ECU 40”) which will be described later. Or it can be retarded.

  On the other hand, the exhaust valve 13 is opened and closed by the exhaust valve cam 16 at a predetermined timing. An exhaust valve opening / closing timing control mechanism 17 (VVT) is provided for the exhaust valve cam 16. The exhaust valve opening / closing timing control mechanism 17 can advance or retard the opening / closing timing of the exhaust valve 13 via the exhaust valve cam 16 in accordance with a control signal from the ECU 40.

  The fuel injection valve 9 is disposed in the intake port 10. The fuel injection valve 9 is disposed such that its fuel injection port faces the intake port 10 and faces downstream with respect to the flow direction of air sucked into the fuel chamber 5 (hereinafter referred to as “intake air”). . Although not shown in detail, the fuel injection valve 9 incorporates a needle valve and a solenoid, receives a pulse signal, is driven for a time corresponding to the pulse width at the pulse input timing, and opens the valve. An amount of fuel corresponding to the time is injected into the air in the intake port 10. Although not shown, fuel is supplied to the fuel injection valve 9 from a fuel pump via a fuel supply passage. The engine E is a port injection engine that injects fuel into the intake port 10, but the engine may be a direct injection engine that directly injects fuel from a fuel injection valve into the combustion chamber 5.

  An intake device that supplies air for fuel combustion (that is, intake air) to the combustion chamber 5 of each cylinder 3 of the engine E is provided, and this intake device has a single common intake passage 20 whose tip opens to the atmosphere. Is provided. The common intake passage 20 has an air cleaner 21 that removes dust and the like in the intake air, an air flow meter 22 that detects the flow rate of the intake air, and the air flow meter 22 that are not shown in the drawing in order from the upstream side in the flow direction of the intake air. A throttle valve 23 is provided to throttle the common intake passage 20 in accordance with the accelerator depression amount (that is, the accelerator opening). The throttle valve 23 is an electric throttle valve that is opened and closed by an electric throttle actuator 24 according to the accelerator opening. Further, the throttle valve 23 is provided with a throttle sensor 25 for detecting the opening degree (that is, the throttle opening degree).

  The downstream end of the common intake passage 20 with respect to the flow direction of the intake air is connected to a surge tank 26 that attenuates the pulsation of the intake air and stabilizes the flow. An independent intake passage 27 that supplies intake air to the combustion chamber 5 of each cylinder is connected to the surge tank 26, and its downstream end is connected to the intake port 10 of the corresponding cylinder 3.

  An exhaust device that exhausts the combustion gas or exhaust gas generated in the combustion chamber 5 of each cylinder 3 of the engine E to the atmosphere is provided, and this exhaust device is provided with an exhaust passage 29 that exhausts the exhaust gas to the atmosphere. ing. Although not shown, the exhaust passage 29 is provided with an exhaust gas purification device (catalytic converter) using a three-way catalyst for purifying the exhaust gas.

  The automobile W is provided with a generator 30 (alternator) that is rotationally driven by the crankshaft 7 of the engine E. Although not shown in detail, a V-belt is wound around a drive pulley attached to the front end portion of the crankshaft 7 and a driven pulley attached to the front end portion of the rotating shaft of the generator 30, and the generator 30 is rotationally driven by the crankshaft 7 to generate electric power. In addition, the drive form of the generator 30 is not necessarily limited to such a thing, What kind of thing may be sufficient. The generator 30 supplies electric power to various electric loads of the engine E and the automobile W and charges the battery 31 with surplus electric power.

  Although not shown in detail, the battery 31 is a lead storage battery, and its positive electrode is electrically connected to the generator 30 and various electric loads by a conducting wire L. The battery 31 also supplies power to the ECU 40. The battery 31 is not limited to a lead storage battery, and any battery may be used. The conducting wire L is provided with a first current sensor 32 that detects an output current of the generator 30 and a second current sensor 33 that detects a charging / discharging current of the battery 31.

  Further, the engine E or the automobile W is provided with a crank sensor 34 that detects a crank angle or an engine speed, a vehicle speed sensor 35 that detects a vehicle speed, and an accelerator sensor 36 that detects an accelerator opening.

  Hereinafter, a control system for the engine E or the automobile W will be described. The automobile W is provided with an ECU 40 that performs various controls of the engine E. The ECU 40 includes a central processing unit (CPU) that executes processing such as computation according to a program, a memory such as a RAM or ROM that stores programs and data, and an input / output bus (I) that serves as an input / output path for electrical signals to the ECU 40. / O bus) or the like, or an electronic control device including a microcomputer.

  The ECU 40 includes “voltage control means”, “throttle control means”, “intake valve opening / closing timing control means” and “exhaust valve opening / closing timing control means” described in the section for solving the problems of the present specification. It is a comprehensive control device for the engine E or the automobile W including the engine E. Then, the ECU 40 has, as control information, a flow rate of intake air detected by the air flow meter 22, a throttle opening detected by the throttle sensor 25, a generator output current detected by the first current sensor 32, a second current. The battery charge / discharge current detected by the sensor 33, the crank angle or engine speed detected by the crank sensor 34, the vehicle speed detected by the vehicle speed sensor 35, the accelerator opening detected by the accelerator sensor 36, and the like are input. The ECU 40 calculates the remaining battery capacity (SOC) based on the battery charge / discharge current.

  The ECU 40 controls the spark plug 8, the fuel injection valve 9, the intake valve opening / closing timing control mechanism 15, the exhaust valve opening / closing timing control mechanism 17, the throttle actuator 25, the generator 30, and the like based on these control information. Thus, engine control according to the present invention including deceleration fuel cut control, deceleration regeneration control, and the like is performed. The ECU 40 also performs general engine control other than the engine control according to the present invention. However, such general engine control is well known to those skilled in the art. Further, since it is not the gist of the present invention, the description thereof is omitted.

  First, an outline of engine control (hereinafter simply referred to as “engine control”) according to the present invention including deceleration fuel cut control, deceleration regeneration control, and the like executed by the ECU 40 will be described. In this engine control, the ECU 40 controls the output voltage of the generator 30 so as to promote charging of the battery 31 during the deceleration fuel cut operation and to suppress charging of the battery 31 during the non-deceleration fuel cut operation. Then, according to the operating state of the engine E, the opening / closing timing of the intake valve 12 and the opening / closing timing of the exhaust valve 13 are controlled. Further, the throttle valve 23 is opened during the deceleration fuel cut operation. Further, during the deceleration fuel cut operation when the driving load of the generator 30 is equal to or less than the predetermined load, the valve closing timing of the intake valve 12 is controlled so that the intake charge amount is reduced. Thus, the closing timing of the intake valve 12 when controlling the closing timing of the intake valve 12 so as to reduce the intake charge amount is set to the middle stage of the compression stroke.

  In this engine control, the ECU 40 controls the closing timing of the intake valve 12 so as to reduce the pumping loss during the deceleration fuel cut operation when the driving load of the generator 30 exceeds a predetermined load. The opening / closing timing of the intake valve 12 and the exhaust valve 13 is such that the closing timing of the intake valve 12 and the opening timing of the exhaust valve 13 are equal in crank angle from the bottom dead center with the bottom dead center in the expansion stroke. Thus, the opening timing of the intake valve 12 is set within the compression stroke, and the opening timing of the exhaust valve 13 is set within the expansion stroke.

Hereinafter, a specific control procedure of the engine control executed by the ECU 40 will be described with reference to the flowchart shown in FIG.
As shown in FIG. 2, when the ECU 40 starts engine control (start), first, in step S1, the vehicle speed Sv, the engine rotational speed Ne, the accelerator opening θ, the generator output current Ia, and the battery charge / discharge current Ib is read as control information, and the operating state of the engine E or the automobile W is grasped.

  Next, in steps S2 to S4, it is determined whether or not a fuel stop condition, that is, a condition necessary for executing the deceleration fuel cut is satisfied (satisfied). Specifically, in step S2, it is determined whether or not the vehicle speed Sv is 0. In step S3, it is determined whether or not the accelerator opening θ is 0 (fully closed). In step S4, the engine speed is determined. It is determined whether or not the fuel stop lower limit rotational speed α is equal to or higher.

In this engine control, the deceleration fuel cut is started when all of the following three conditions are satisfied. As will be described later, after the deceleration fuel cut is started, if the engine speed Ne exceeds the fuel return rotation speed β even if the following condition 3 is not satisfied, the deceleration fuel cut is performed. continue.
Condition 1: The vehicle speed Sv is not zero.
Condition 2: The accelerator opening θ is 0 (fully closed).
Condition 3: The engine rotational speed Ne is equal to or higher than the fuel stop lower limit rotational speed α.

  Here, when the vehicle speed Sv is 0, that is, when the vehicle is not running, the deceleration fuel cut is not performed because when the vehicle speed Sv is 0, the engine E is not reversely driven by the wheels. This is because when the fuel supply is stopped, the engine E stops. The reason for not performing the deceleration fuel cut when the accelerator opening θ is not 0 (fully closed) is that the driver of the automobile W intends to accelerate or steady travel, so if the fuel supply to the engine E is stopped, the driver's intention This is because the vehicle cannot travel along the road. Further, when the engine rotational speed Ne is less than the fuel stop lower limit rotational speed α, the deceleration fuel cut is not performed. When the deceleration fuel cut is started below the fuel stop lower limit rotational speed α, the engine rotational speed Ne is This is because the fuel return rotational speed β, which will be described later, decreases in a very short time, and the effectiveness of the deceleration fuel cut becomes dilute. Needless to say, the value of the fuel stop lower limit rotational speed α is larger than the value of the fuel return rotational speed β (α> β).

  Thus, it is determined in step S2 that the vehicle speed Sv is not 0 (NO), in step S3 it is determined that the accelerator opening θ is 0 (fully closed) (YES), and in step S4, the engine speed Ne is stopped. When it is determined that the rotation speed is equal to or higher than the lower limit rotation speed α (YES), the deceleration fuel cut is executed in steps S5 to S7. Specifically, first, in step S5, the throttle valve 23 is opened (substantially fully opened) in order to suppress the pumping loss and reduce the engine braking force, thereby improving the fuel efficiency. Subsequently, in step S6, “1” is set in the fuel cut flag, and in step S7, the fuel injection valve 9 stops the fuel injection. The fuel cut flag is a flag that is set to “1” while the deceleration fuel cut is being executed, and is set to “0” when the fuel injection valve 9 is performing fuel injection.

  After starting the deceleration fuel cut in this way, the output voltage of the generator 30 is set to a high voltage level (High) in step S8. That is, in order to regenerate excess mechanical energy (deceleration energy) at the time of deceleration fuel cut, the output voltage of the generator 30 is increased to promote charging of the battery 31.

  Next, it is determined whether the drive load of the generator 30 is below a predetermined load by determining whether the generator output current Ia is below a predetermined current in step S9. When it is determined that the generator output current Ia is equal to or less than the predetermined current (YES), that is, when the driving load of the generator 30 is equal to or less than the predetermined load, the opening / closing timing of the intake valve 12 is retarded in step S10. Return to step S1 (return). In this case, the pumping loss increases while the intake air amount decreases. In FIG. 2, IO and IC are the opening timing and closing timing of the intake valve 12, respectively. EO and EC are the opening timing and closing timing of the exhaust valve 13, respectively.

  FIG. 4 shows a PV diagram in the case where the opening / closing timing of the intake valve 12 is set to the retarded state in this manner at the time of deceleration fuel cut. As described above, when the generator output current Ia is equal to or less than the predetermined current, the driving load of the generator 30 is small, and the engine braking force resulting from the driving load of the generator 30 is small. Therefore, even if the opening / closing timing of the intake valve 12 is set to the retarded state and the pumping loss is increased, the engine braking force due to the driving load of the generator 30 is small, so the engine braking force as a whole is appropriate. It becomes.

  Further, in this case, since the intake air amount is reduced, it is possible to prevent the output torque from temporarily rising and generating a torque shock when the fuel is returned from the deceleration fuel cut. If the intake air amount is not reduced, the throttle valve 23 is opened during the deceleration fuel cut operation (step S5), so that the intake air amount and thus the output torque temporarily increase when the fuel is restored. Torque shock occurs.

  On the other hand, when it is determined in step S9 that the generator output current Ia exceeds the predetermined current (NO), that is, when the driving load of the generator 30 exceeds the predetermined load, in step S11, the intake valve 12 The opening / closing timing is set to the advanced state, and the process returns to step S1 (return). In this case, the pumping loss is reduced while the intake air amount is increased.

  FIG. 5 shows a PV diagram in the case where the opening / closing timing of the intake valve 12 is set to the advanced state in this way at the time of deceleration fuel cut. Thus, when the generator output current Ia exceeds the predetermined current, the driving load of the generator 30 is large, and the engine braking force resulting from the driving load of the generator 30 is in a large state. Therefore, the opening / closing timing of the intake valve 12 is set to an advanced state so that the pumping loss can be reduced. Thereby, the pumping loss can be reduced and the fuel efficiency can be improved while making the engine braking force appropriate by the driving load of the generator 30.

  In addition, when the generator output current Ia exceeds the predetermined current as described above, the opening / closing timing of the intake valve 12 and the exhaust valve 13 is reduced when the closing timing of the intake valve 12 and the opening timing of the exhaust valve 13 are lowered. The crank angle is set to be equal from the bottom dead center across the dead center. Further, the valve opening timing of the exhaust valve 13 is controlled so as to reach the most advanced position. This is because the control amount for changing the opening / closing timing of the intake valve 12 can be reduced when the state transitions between step S10 and step S11.

  If it is determined in step S4 that the engine rotational speed Ne is less than the fuel stop lower limit rotational speed α (NO), it is determined in step S12 whether or not the fuel cut flag is 1. If it is determined that the fuel cut flag is 1 (YES), that is, if the engine rotation speed Ne is lower than the fuel stop lower limit rotation speed α during execution of the deceleration fuel cut, the engine rotation is performed in step S13. It is determined whether or not the speed Ne is equal to or lower than the fuel return rotational speed β. Here, the fuel return rotation speed β is a threshold value for determining whether or not the deceleration fuel cut should be terminated due to the decrease in the engine rotation speed Ne during the execution of the deceleration fuel cut, and the engine rotation speed Ne is lower than this. This is the rotational speed at which the rotation of the engine E may become unstable. If it is determined in step S13 that the engine rotational speed Ne exceeds the fuel return rotational speed β (NO), steps S5 to S11 are executed to continue the deceleration fuel cut.

  On the other hand, if it is determined in step S13 that the engine rotational speed Ne is equal to or lower than the fuel return rotational speed β (YES), the deceleration fuel cut is terminated and fuel return is performed. Specifically, first, in step S14, the throttle valve 23 is closed to reduce the intake air amount. Next, “0” is set to the fuel cut flag in step S15, and subsequently, fuel injection is restarted in the fuel injection valve 9 in step S16.

  After performing the fuel return in this way, it is determined in step S17 whether or not the remaining battery capacity Cb is equal to or less than the lower limit capacity. If it is determined that the remaining battery capacity Cb exceeds the lower limit capacity, the output voltage of the generator 30 is set to a low voltage level (Low) in step S18, and the process returns to step S1 (return). That is, during the non-decelerating fuel cut operation, the driving load of the generator 30 is reduced in order to improve fuel efficiency. The remaining battery capacity Cb may be calculated by a well-known method from the battery charge / discharge current Ib.

  On the other hand, if it is determined in step S17 that the remaining battery capacity Cb is equal to or lower than the lower limit capacity (YES), the output voltage of the generator 30 is set to a high voltage level (High) in step S19, and the process returns to step S1 ( return). That is, in this engine control, a lower limit capacity for preventing overdischarge of the battery 31 is set, and when the remaining capacity of the battery 31 becomes equal to or lower than the lower limit capacity, the output voltage of the generator 30 is increased to charge the battery 31. To promote.

  If it is determined in step S2 that the vehicle speed Sv is 0 (YES), if it is determined in step S3 that the accelerator opening θ is not 0 (fully closed), or if the fuel cut flag is set in step S12. If it is determined that the value is not 1 (NO), the deceleration fuel cut cannot be executed in any case, so steps S15 to S19 are executed to perform the non-deceleration fuel cut operation.

  By the way, in the engine control shown in FIG. 2, as described above, it is determined whether or not the drive load of the generator 30 is equal to or less than the predetermined load, and whether or not the generator output current Ia is equal to or less than the predetermined current. (Step S9). However, the method for determining whether or not the driving load of the generator 30 is equal to or less than the predetermined load is not limited to this, and other methods may be used.

  For example, as shown in FIG. 3, instead of step S9 of engine control shown in FIG. 2, by executing step S20 for determining whether or not the remaining battery capacity Cb is equal to or greater than a predetermined capacity, You may make it determine whether a drive load is below a predetermined load. As described above, the remaining battery capacity Cb can be calculated from the battery charge / discharge current Ib by a well-known method.

  As described above, according to the engine control according to the present invention, when the driving load of the generator 30 is equal to or less than the predetermined load, that is, in a situation where the driving load of the generator is small, the intake charge amount during the deceleration fuel cut operation is reduced. Thus, it is possible to prevent or suppress the occurrence of a torque shock at the time of fuel return from the deceleration fuel cut operation. On the other hand, when the driving load of the generator 30 exceeds a predetermined load, the closing timing of the intake valve 12 is controlled so as to reduce the pumping loss, so that fuel efficiency can be improved and an appropriate engine braking force can be obtained. Can be obtained.

It is a mimetic diagram showing the system configuration of the engine provided with the engine control device concerning the present invention. It is a flowchart which shows the control procedure of the engine control in the engine shown in FIG. It is a flowchart which shows the control procedure of another engine control in the engine shown in FIG. It is a PV diagram of the engine at the time of deceleration fuel cut operation when the drive load of the generator is small. It is a PV diagram of the engine at the time of deceleration fuel cut operation when the driving load of the generator is large.

Explanation of symbols

  W automobile, E engine, L lead wire, 1 cylinder head, 2 cylinder block, 3 cylinder, 4 piston, 5 combustion chamber, 6 connecting rod, 7 crankshaft, 8 spark plug, 9 fuel injection valve, 10 intake port, 11 exhaust Port, 12 Intake valve, 13 Exhaust valve, 14 Intake valve cam, 15 Intake valve opening / closing timing control mechanism, 16 Exhaust valve cam, 17 Exhaust valve opening / closing timing control mechanism, 20 Common intake passage, 21 Air cleaner, 22 Air flow meter, 23 Throttle Valve, 24 throttle actuator, 25 throttle sensor, 26 surge tank, 27 independent intake passage, 29 exhaust passage, 30 generator, 31 battery, 32 first current sensor, 33 second current sensor, 34 crank sensor, 35 vehicle speed sensor, 36 Accelsen 40, engine control unit (ECU).

Claims (3)

The output voltage of the generator rotated by the engine, while set to a high voltage level so as to facilitate the charging of Batterihe during deceleration fuel cut-off operation, the can not equal during deceleration fuel cut operation inhibiting charging of the Batterihe Voltage control means for setting the low voltage level lower than the high voltage level ,
In an engine control device comprising an intake valve opening / closing timing control means for controlling the opening / closing timing of the intake valve according to the operating state of the engine,
Parameter value detection means for detecting a parameter value corresponding to the load of the engine resulting from the drive of the generator;
The deceleration fuel cut operation when the load of the engine due to driving of the generator is below the predetermined load, have a throttle control means for controlling the throttling valve in the open state,
The intake valve closing timing control means, the load of the engine due to driving of the generator at the time of deceleration fuel cut operation when the following said predetermined duty, the closing timing of the upper Symbol intake valve, less intake air charging amount An engine control device that is set in the middle of the compression process so that a pumping loss is increased . The intake valve opening / closing timing control means is configured to reduce the pumping loss during the deceleration fuel cut operation when the engine load resulting from the drive of the generator exceeds the predetermined load. The engine control device according to claim 1, wherein the engine control device is controlled. Exhaust valve opening / closing timing control means for controlling the opening / closing timing of the exhaust valve according to the operating state of the engine,
The opening / closing timing of the intake valve and the exhaust valve when controlling the closing timing of the intake valve so as to reduce pumping loss is the expansion stroke of the closing timing of the intake valve and the opening timing of the exhaust valve. The crank angle from the bottom dead center is equal across the bottom dead center, the opening timing of the intake valve is set in the compression stroke, and the opening timing of the exhaust valve is set in the expansion stroke. The engine control apparatus according to claim 2 , wherein the engine control apparatus is provided.

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