JP2018016269A - Vehicle driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle driving system which can suppress power consumption by rotating a crank shaft at operation rotational frequency of a decompression device during fuel injection stop, which can reduce a load with respect to a motor for driving by suppressing a heating value from a motor for driving, and which can improve quietness performance by reducing operation shock and the like.SOLUTION: A vehicle driving system includes a decompression device 10 for reducing a compression pressure in a cylinder of an engine 20 being interlocked with the rotation of predetermined rotational frequency or less of a crank shaft 22. In the case where the vehicle is in a stopped state, a motor 70 for driving is driven during injection stop of a fuel supplied to the engine 20, and the rotation of the crank shaft 22 is maintained at the rotational frequency of the predetermined rotational frequency or less at which the decompression device 10 operates.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle drive system including a decompression device.

  In recent years, vehicles have been known in which an engine is temporarily stopped automatically to enter an idle stop state when a predetermined idle stop condition is satisfied. In such a vehicle, a time lag occurs from the idle stop state until the engine is restarted. Therefore, the driver tends to open the throttle to obtain the desired acceleration when the engine is restarted. In such a case, there is a problem that fuel and air are excessively supplied to the engine and fuel consumption is deteriorated.

  On the other hand, Patent Document 1 relates to a vehicle drive system. When performing idle stop, the fuel injection is stopped and the rotation of the crankshaft is maintained by the motor until the engine is restarted from the idle stop state. A configuration that eliminates the time lag is proposed.

Japanese Patent Laying-Open No. 2015-074296

  Here, according to the study of the present inventor, in the vehicle drive system of Patent Document 1, since the motor is operated when the fuel injection is stopped, the power consumption of the battery is increased, and the power necessary for starting the engine is obtained. This increases the amount of heat generated by the motor and increases the load on the motor, such as motor burn-in. Moreover, in the vehicle drive system of patent document 1, when stopping a fuel injection and driving a motor, there exists a possibility of producing an operation shock.

  The present invention has been made through the above-described studies. When the vehicle is in a stopped state, the power consumption can be suppressed by rotating the crankshaft at the operation speed of the decompression device when the fuel injection is stopped. It is possible to provide a vehicle drive system that can reduce the amount of heat generated by the drive motor and reduce the load on the drive motor, and can improve quietness performance by reducing operation shocks and the like. Objective.

  In order to achieve the above object, in the first aspect, the present invention provides a vehicle running engine, a drive motor for rotating a crankshaft of the engine, and a control for controlling the engine and the drive motor. And a decompression device that reduces the compression pressure in the cylinder of the engine in conjunction with rotation of the crankshaft not more than a predetermined number of revolutions, wherein the control unit is configured to stop the vehicle. In this case, when the injection of fuel supplied to the engine is stopped, the drive motor is driven to maintain the rotation of the crankshaft at a rotation speed equal to or lower than the predetermined rotation speed at which the decompression device operates. It is.

  In the vehicle drive system according to the first aspect of the present invention, a vehicle running engine, a drive motor that rotates a crankshaft of the engine, a control unit that controls the engine and the drive motor, and a predetermined crankshaft are provided. A decompression device that reduces the compression pressure in the cylinder of the engine in conjunction with a rotation equal to or less than the number of revolutions, wherein the controller supplies fuel to the engine when the vehicle is stopped When the fuel injection is stopped, the drive motor is driven to maintain the rotation of the crankshaft at a rotation speed equal to or lower than the predetermined rotation speed at which the decompression device operates. By rotating the crankshaft at the operating speed of the decompression device, power consumption can be reduced, and the drive motor can be driven with reduced heat generation. It is possible to reduce the load on the motor, it is possible to improve the quietness performance so as to reduce the operation shock and the like.

FIG. 1 is a block diagram illustrating a configuration of a vehicle drive system according to an embodiment of the present invention and a timing chart illustrating a flow of a start time lag suppression control process. FIG. 2 is a flowchart showing the start time lag suppression control process according to the embodiment of the present invention.

  Hereinafter, a vehicle drive system according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

<Configuration of vehicle drive system>
First, with reference to Fig.1 (a), it demonstrates in detail about the structure of the vehicle drive system in this embodiment.

  Fig.1 (a) is a block diagram which shows the structure of the vehicle drive system 1 which concerns on embodiment of this invention.

  As shown in FIG. 1, a vehicle drive system 1 according to this embodiment is mounted on a vehicle (not shown), typically a motorcycle, and includes a decompression device 10, an engine 20, a crank angle sensor 30, an ignition coil 40, An injector 50, an exhaust valve 60, a drive motor 70, and an ECU (Electronic Control Unit) 80 are provided.

  The decompression device 10 reduces the compression pressure in the cylinder 23 of the engine 20 by slightly opening the exhaust valve 60 using a stopper (not shown) of the exhaust valve 60 in conjunction with the rotation of the crankshaft 22 or less. The power required for starting the engine 20 is reduced by performing the pressure reducing operation. The decompression device 10 releases the stopper of the exhaust valve 60 and releases the decompression operation when the rotation speed of the crankshaft 22 becomes greater than a predetermined rotation speed.

  The engine 20 is an internal combustion engine used for running a vehicle. The engine 20 is a timing rotor 21, a crankshaft 22 that converts a linear reciprocating motion of a piston into a rotational motion, an ignition coil 40, a spark plug 41, an injector 50, and an exhaust. It has a valve 60 and the like.

  The crank angle sensor 30 is disposed in the vicinity of the timing rotor 21, detects the rotation angle of the timing rotor 21, and outputs an electrical signal corresponding to the detected rotation angle to the waveform shaping circuit 81 of the ECU 80.

  The ignition coil 40 includes a primary coil and a secondary coil (not shown). The ignition coil 40 is controlled by an induction power generated by cutting off the energization of the primary coil after the energization of the primary coil for a predetermined time under the control of the ignition circuit 83 of the ECU 80. A high voltage current is generated in the next coil, thereby applying a high voltage between the electrodes of the spark plug 41.

  The spark plug 41 sparks when a high voltage is applied between the electrodes from the ignition coil 40 and ignites the combustion gas in the cylinder 23 of the engine 20.

  The injector 50 performs a fuel supply operation for supplying fuel to the engine 20 under the control of the drive circuit 84 of the ECU 80.

  The exhaust valve 60 is driven in conjunction with the rotation of the engine 20. The exhaust valve 60 includes a stopper that is driven by the decompression operation of the decompression device 10.

  The drive motor 70 is driven by the control of the drive circuit 84 of the ECU 80 to rotate the crankshaft 22. As the drive motor 70, a motor having a specification that serves as both a starting device such as an ACG starter and a generator, or a motor having a specification only for the starting device is used. The drive motor 70 and the crankshaft 22 have a constantly meshing configuration that always meshes.

  The ECU 80 is a control device that operates using electric power supplied from a battery (not shown) mounted on the vehicle and can control various components of the vehicle. Specifically, the ECU 80 includes a waveform shaping circuit 81, a CPU 82, an ignition circuit 83, and a drive circuit 84.

  The waveform shaping circuit 81 shapes the waveform of the electrical signal input from the crank angle sensor 30 and outputs the electrical signal whose waveform has been shaped to the CPU 82.

  The CPU 82 operates in accordance with a predetermined control program, detects the rotational speed of the crankshaft 22 based on the electrical signal input from the waveform shaping circuit 81, and detects the rotational speed of the engine 20. The CPU 82 outputs a control signal for controlling the ignition circuit 83 to the ignition circuit 83 or outputs a control signal for controlling the drive circuit 84 to the drive circuit 84 based on the detection result of the rotational speed of the engine 20. The CPU 82 executes a start time lag suppression control process and outputs a control signal for performing a control to suppress a time lag from the idle stop state until the engine 20 is restarted to the ignition circuit 83 or the drive circuit 84.

  The ignition circuit 83 controls the ignition operation of the ignition coil 40 according to a control signal from the CPU 82.

  The drive circuit 84 controls the operation of the injector 50 and the drive motor 70 in accordance with a control signal input from the CPU 82. Specifically, the drive circuit 84 stops the fuel supply operation of the injector 50 when the drive motor 70 stops operating according to a control signal input from the CPU 82 by execution of the start time lag suppression control process in the CPU 82. In the case where the drive motor 70 is driven before and the fuel supply operation of the injector 50 is stopped, the fuel supply operation of the injector 50 is started before the drive of the drive motor 70 is stopped.

  The vehicle drive system 1 having the above configuration executes a start time lag suppression control process shown below. Hereinafter, the start time lag suppression control process in the present embodiment will be described in detail with reference to FIG.

<Start time lag suppression control processing>
With reference to FIG.1 (b) and FIG. 2, it demonstrates in detail about the start time lag suppression control process which the vehicle drive system 1 in this embodiment performs.

  FIG.1 (b) is a timing chart figure which shows the flow of the start time lag suppression control process which concerns on embodiment of this invention. FIG. 2 is a flowchart showing the start time lag suppression control process according to the embodiment of the present invention.

  The start time lag suppression control process shown in FIG. 2 is started when the ignition switch is turned on, and the start time lag suppression control process proceeds to the process of step S1. The start time lag suppression control process shown in FIG. 2 is repeatedly executed until the ignition switch is turned off.

  In the process of step S1, the CPU 82 determines whether the vehicle speed of the vehicle is equal to or lower than a predetermined speed. As a result of the determination, when the vehicle speed of the vehicle is higher than the predetermined speed, the CPU 82 ends the start time lag suppression control process. On the other hand, when the vehicle speed of the vehicle is equal to or lower than the predetermined speed, the CPU 82 advances the start time lag suppression control process to step S2. Here, the predetermined speed is typically 0 km / h.

  Specifically, as shown in FIG. 1B, the vehicle starts decelerating at time t = t1. The CPU 82 performs fuel injection and ignition processing (hereinafter referred to as “steady state processing”) during normal travel (such as during steady travel) until time t = t1, and at time t = t1, a deceleration fuel cut (hereinafter “ F-cut ") is started to stop the steady process. Further, the CPU 82 stops the F-cut at the time t = t2 and starts the steady process. The CPU 82 repeats the process of step S1 until time t = t3. Then, at time t = t3, the vehicle speed becomes 0 km / h, which is equal to or lower than the predetermined speed, and the vehicle stops, and the CPU 82 advances the start time lag suppression control process to step S2.

  In the process of step S2, the CPU 82 determines whether or not the idle stop control is being performed. As a result of the determination, if the idle stop control is being performed, the CPU 82 advances the start time lag suppression control process to step S8. If not, the CPU 82 advances the start time lag suppression control process to step S3. .

  Specifically, as shown in FIG. 1B, since the idle stop control is not being performed at time t = t3, the CPU 82 advances the start time lag suppression control process to step S3.

  In the process of step S3, the CPU 82 detects the rotational speed of the crankshaft 22 based on the electric signal input from the waveform shaping circuit 81, and the rotational speed of the engine 20 enables the conventional idle stop control to be performed. It is determined whether or not (hereinafter referred to as “conventional IS rotation speed”). As a result of the determination, when the rotational speed of the engine 20 is larger than the conventional IS rotational speed, the CPU 82 ends the start time lag suppression control process. Thereby, the start time lag suppression control process repeats the process from step S1 to step S3 until the rotational speed of the engine 20 converges to the conventional IS rotational speed. On the other hand, when the rotation speed of the engine 20 is equal to or lower than the conventional IS rotation speed, the CPU 82 advances the start time lag suppression control process to step S4. Thereby, the start time lag suppression control process proceeds to the processes of steps S4, S5, and S6 sequentially after the engine speed of the engine 20 has converged to the conventional IS engine speed.

  Specifically, as shown in FIG. 1B, since the rotational speed of the engine 20 becomes equal to or lower than the conventional IS rotational speed NE3 at time t = t3, the CPU 82 advances the start time lag suppression control process to step S4.

  In the process of step S4, the CPU 82 performs a thinning process for controlling the drive circuit 84 to reduce the frequency of fuel injection in the injector 50.

  Specifically, as shown in FIG. 1B, the CPU 82 starts the thinning process and stops the steady process at time t = t4.

  Thereby, the process of step S4 is completed and the start time lag suppression control process proceeds to step S5.

  In the process of step S5, the CPU 82 drives the drive circuit 84 to start energization of the drive motor 70, and the energization amount to the drive motor 70 so that the rotation speed of the crankshaft 22 becomes the target rotation speed. Energization control is performed to gradually increase. When the rotation speed of the crankshaft 22 becomes equal to or less than a predetermined rotation speed smaller than the conventional IS rotation speed by performing such energization control, the decompression device 10 starts a pressure reducing operation.

  Specifically, as shown in FIG. 1B, the CPU 82 starts energization of the driving motor 70 that has stopped driving at time t = t4. Further, since the rotation speed of the crankshaft 22 is not the target rotation speed NE1 at the time t = t4, the CPU 82 sets the energization amount to the drive motor 70 so that the rotation speed of the crankshaft 22 becomes the target rotation speed NE1. Conduct energization control to increase gradually. Further, the decompression device 10 starts the pressure reducing operation at time t = t5 when the rotation speed becomes NE2 or less, which is smaller than the conventional IS rotation speed NE3. The decompression device 10 continues the pressure reducing operation from time t = t5 until time t = t8 when the rotation speed of the crankshaft 22 starts to rise again and reaches a predetermined rotation speed.

  Thereby, the process of step S5 is completed and the start time lag suppression control process proceeds to step S6.

  In step S6, the CPU 82 detects the rotational speed of the crankshaft 22 based on the electric signal input from the waveform shaping circuit 81, and determines whether or not the rotational speed of the engine 20 has reached the target rotational speed. . As a result of the determination, when the rotational speed of the engine 20 has not reached the target rotational speed, the CPU 82 ends the start time lag suppression control process. Thereby, the start time lag suppression control process repeats the process from step S1 to step S6 until the rotation speed of the engine 20 converges to the target rotation speed. On the other hand, when the rotation speed of the engine 20 reaches the target rotation speed, the CPU 82 advances the start time lag suppression control process to step S7. Accordingly, the start time lag suppression control process proceeds to the processes of steps S7, S8, and S9 in order after the engine speed of the engine 20 has converged to the target engine speed.

  Specifically, as shown in FIG. 1B, the CPU 82 repeats the processing from step S1 to step S6 until time t6. Then, since the rotational speed of the engine 20 reaches the target rotational speed NE1 at time t = t6, the CPU 82 advances the start time lag suppression control process to step S7.

  In the process of step S7, the CPU 82 starts idle stop control.

  Specifically, the CPU 82 starts the idle stop control and stops the thinning-out process because the rotation speed of the engine 20 reaches the target rotation speed NE1 at time t = t6.

  Thereby, the process of step S7 is completed and the start time lag suppression control process proceeds to step S8.

  In the process of step S <b> 8, the CPU 82 controls the energization of the drive motor 70 by controlling the drive circuit 84 so that the rotation speed of the engine 20 maintains a target rotation speed that is equal to or lower than the rotation speed at which the decompression device 10 operates. . In this way, by maintaining the rotational speed of the crankshaft 22 at the target rotational speed during the idle stop control, the decompression device is operated to enter the pressure reducing operation state, so that the load in the compression process is reduced. In addition, the amount of heat generated by the drive motor 70 can be suppressed and the load on the drive motor 70 can be reduced.

  Specifically, as shown in FIG. 1B, the CPU 82 is driven so as to maintain the target rotational speed NE1 that is equal to or lower than the rotational speed NE2 at which the decompression device 10 operates from time t = t6 to time t = t7. The circuit 84 is controlled to control energization of the drive motor 70.

  Thereby, the process of step S8 is completed and the start time lag suppression control process proceeds to step S9.

  In step S9, the CPU 82 controls the drive circuit 84 to determine whether or not the throttle operation has been performed in a state where the rotation speed of the crankshaft 22 driven by the drive motor 70 is maintained at the target rotation speed. . As a result of the determination, if the throttle is not operated, the CPU 82 ends the start time lag suppression control process. As a result, the start time lag suppression control process returns to the process of step S1 and is determined to be YES in the process of step S2. Therefore, the processes of steps S1, S2, S8 and S9 are repeated. On the other hand, when the throttle is operated, the CPU 82 advances the start time lag suppression control process to step S10.

  Specifically, by performing the throttle operation at time t = t7 in a state where the rotation speed of the crankshaft 22 is maintained at the target rotation speed NE1, the CPU 82 advances the start time lag suppression control process to step S10.

  In the process of step S <b> 10, the CPU 82 controls the drive circuit 84 to gradually increase the rotation speed of the drive motor 70, thereby increasing the rotation speed of the crankshaft 22 driven by the drive motor 70. At this time, since the rotational speed of the crankshaft 22 is increased from a target rotational speed that is smaller than the conventional IS rotational speed, quiet performance can be improved by reducing operation shocks and the like.

  Thereby, the process of step S10 is completed and the start time lag suppression control process proceeds to step S11.

  In the process of step S11, the CPU 82 ends the idle stop control.

  Specifically, the CPU 82 ends the idle stop control at the time t = t7 and starts the steady process, and controls the drive circuit 84 to increase the rotation speed of the crankshaft 22 driven by the drive motor 70. .

  Thereby, the process of step S11 is completed and the start time lag suppression control process proceeds to step S12.

  In the process of step S12, the CPU 82 controls the ignition circuit 83 to ignite the ignition plug 41 by the ignition operation of the ignition coil 40, and also controls the drive circuit 84 to start fuel injection in the injector 50, thereby causing the engine 20 to start. Start. At this time, in a state where the crankshaft 22 is rotated by the drive motor 70, an ignition signal is sent to the ignition coil 40 to ignite the spark plug 40 and fuel injection in the injector 50 is started. The time lag until the engine is restarted can be eliminated.

  Specifically, after time t = t7, the rotational speed of the crankshaft 22 gradually increases, and at time t = t8 when the rotational speed of the crankshaft 22 becomes greater than a predetermined rotational speed, the decompression device 10 ends the decompression operation. .

  Thereby, the process of step S12 is completed and a start time lag suppression control process is complete | finished.

  In the vehicle drive system according to the above-described embodiment of the present invention, the vehicle running engine 20, the drive motor 70 that rotates the crankshaft 22 of the engine 20, the ECU 80 that controls the engine 20 and the drive motor 70, The ECU 80 includes a decompression device 10 that reduces the compression pressure in the cylinder of the engine 20 in conjunction with rotation of the crankshaft 22 below a predetermined number of revolutions. The driving motor 70 is driven when the fuel supplied to the engine 20 is stopped, and the rotation of the crankshaft 22 is maintained at a rotational speed equal to or lower than a predetermined rotational speed at which the decompression device 10 operates. When the vehicle is stopped, it is consumed by rotating the crankshaft at the operating speed of the decompression device when fuel injection is stopped. It is possible to suppress the force to suppress the amount of heat generated by the driving motor can reduce the load on the drive motor, it is possible to improve the quietness performance so as to reduce the operation shock and the like.

  In the present invention, the type, shape, arrangement, number, and the like of the members are not limited to the above-described embodiment, and the gist of the invention is appropriately replaced such that the constituent elements are appropriately replaced with those having the same operational effects. Of course, it can be appropriately changed within the range of 2 which does not deviate.

  Specifically, in the above-described embodiment, the constant-mesh drive motor 70 and the crankshaft 22 are used. However, a jump-in drive motor and a crankshaft may be used.

  The jump-in driving motor and the crankshaft are connected by a starter clutch. Such a starter clutch automatically releases the connection between the drive motor and the crankshaft when the engine speed reaches or exceeds a predetermined value. The dive-type drive motor and the crankshaft are automatically meshed when the thinning process and energization of the drive motor are started and the engine speed becomes equal to or less than the starter clutch switching speed.

  Thus, when the dive-type drive motor and the crankshaft are used, after the process of step S5 in FIG. 2 is completed, a synchronization process for matching the engine speed and the crankshaft speed is performed. It is determined whether or not the synchronization has been completed because the engine speed and the crankshaft speed coincide with each other by the synchronization process. As a result of the determination, if the synchronization is not completed, the CPU ends the start time lag suppression control process. If the synchronization is completed, the CPU advances the start time lag suppression control process to the process of step S6 in FIG. . Processes other than those described above in the start time lag suppression control process when the dive-type drive motor and the crankshaft are used are the same as the processes when the constantly meshing drive motor 70 and the crankshaft 22 are used. It becomes.

  In the above embodiment, the target rotational speed NE1 is set to be smaller than the rotational speed NE2 at which the decompression device starts the pressure reducing operation. However, the rotational speed NE2 at which the decompression device starts the pressure reducing operation is set to the target rotational speed. Good.

  Further, in the above embodiment, F-cut is performed from time 1 = t1 to time t = t2, but from time t = t1 to time t = t4 when the idling stop control and energization to the drive motor 70 are started. You may cut. At this time, steady processing is performed from time t = t2 to time t = t4, and thinning processing is not performed from time t = t4 to time t = t6.

  As described above, in the present invention, when the vehicle is stopped, the power consumption can be suppressed by rotating the drive motor at the operation rotational speed of the decompression device when the fuel injection is stopped. It is possible to provide a vehicle drive system that can reduce the load on the drive motor by suppressing the amount of heat generated from the motor, and can improve quietness performance by reducing operation shocks, etc. It is expected that it can be widely applied to vehicle drive systems such as motorcycles because of its universal character.

DESCRIPTION OF SYMBOLS 1 ... Vehicle drive system 10 ... Decompression apparatus 20 ... Engine 21 ... Timing rotor 22 ... Crankshaft 23 ... In-cylinder 24 ... Exhaust passage 30 ... Crank angle sensor 40 ... Ignition coil 41 ... Spark plug 50 ... Injector 60 ... Exhaust valve 70 ... Driving motor 80 ... ECU
81 ... Waveform shaping circuit 82 ... CPU
83 ... Ignition circuit 84 ... Drive circuit

Claims (1)

An engine for driving the vehicle;
A drive motor for rotating the crankshaft of the engine;
A control unit for controlling the engine and the drive motor;
A decompression device that reduces the compression pressure in the cylinder of the engine in conjunction with rotation of the crankshaft below a predetermined number of revolutions;
A vehicle drive system comprising:
The controller is
When the vehicle is stationary, the drive motor is driven when fuel injection to the engine is stopped, and the rotation of the crankshaft is maintained at a speed equal to or lower than the predetermined speed at which the decompression device operates. To
A vehicle drive system characterized by that.

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