JP2017002727A - Engine start-up control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel efficiency by assisting drive of an engine.SOLUTION: An engine start-up control system (3) comprises: a motor (20) which rotates a crank shaft (10); a motor controller (24) which controls output of the motor; and an ECU (2) which performs fuel injection control. The motor has a first circuit pattern and a second circuit pattern which have different output torque. The motor controller drives the motor using the first circuit pattern until an engine rotation speed reaches a first rotation speed. When the engine rotation speed exceeds the first rotation speed, the motor controller drives the motor by switching the same to the second circuit pattern until the engine rotation speed reaches a second rotation speed which is larger than the first rotation speed. The ECU starts the fuel injection control when the engine rotation speed exceeds a third rotation speed which is larger than the first rotation speed and smaller than the second rotation speed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle engine start control system and a vehicle, and more particularly to an engine start control system and a vehicle for assisting engine start with a motor.

  2. Description of the Related Art Conventionally, an engine start control system that starts an engine using a starter generator that has both a function as a motor for driving the engine and a function of generating electric power using the power of the engine has been proposed (see, for example, Patent Document 1). . In the engine start control system described in Patent Document 1, the engine is driven to the number of revolutions necessary for starting the engine by the driving force of the starter generator. When the engine speed is increased to a predetermined speed, fuel injection is started and the engine is started.

JP 2007-255272 A

  However, in the engine start control system described in Patent Document 1, the rotational drive of the engine by the starter generator remains until the engine is started, and no further engine assist has been realized.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an engine start control system capable of assisting driving of an engine and realizing improvement in fuel consumption.

  An engine start control system of the present invention is an engine start control system comprising a motor that rotates a crankshaft, a motor controller that controls the output of the motor, and an engine control device that performs fuel injection control and / or ignition control. The motor includes a first circuit pattern and a second circuit pattern having different output torques, and the motor controller uses the first circuit pattern until the engine speed reaches the first speed. The motor is driven, and when the engine speed exceeds the first speed, the motor is switched to the second circuit pattern until the motor reaches a second speed greater than the first speed. And the engine control device causes the engine speed to be greater than the first speed and smaller than the second speed. Characterized in that to start the fuel injection control and / or ignition control When turned on.

  According to this configuration, when the engine is started from the stopped state, the first circuit and the second circuit are switched to drive the motor, whereby the engine can be driven at a relatively low rotation speed range (the first rotation range). The engine rotational speed can be increased only by the motor from the rotational speed) to the high rotational speed range (second rotational speed) in which the drive torque is suppressed. Then, the engine is started by starting fuel injection control and / or ignition control from the third rotational speed. Thus, by switching the output torque of the motor and increasing the motor drive time until the engine is started, the time until the engine is started can be shortened. On the other hand, since fuel injection time until engine start can be shortened, fuel consumption and noise to the surroundings can be suppressed. As described above, the driving of the engine can be assisted to improve the fuel consumption.

  In addition, the vehicle according to the present invention is a vehicle including the engine start control system, and preferably includes an automatic clutch that is engaged when the engine rotational speed is equal to or higher than a second rotational speed. According to this configuration, the effect obtained by the engine start control system in the vehicle can be enjoyed. Further, the engine speed is increased by driving the motor until the automatic clutch is engaged. Therefore, fuel consumption and noise to the surroundings until the vehicle starts can be suppressed.

  Further, in the vehicle according to the present invention, the motor controller attenuates the driving force of the motor when the second rotational speed is exceeded, and when the motor controller reaches a fourth rotational speed that is greater than the second rotational speed. It is preferable to complete the driving by the motor. According to this configuration, at the timing when the vehicle starts to start, both the fuel injection and the motor drive are performed, and the motor is used to assist the engine drive even when a high torque is required due to the engagement of the automatic clutch. be able to. Moreover, the consumption of electric power can be suppressed by gradually attenuating the motor driving force.

  According to the engine start control system of the present invention, the motor output torque is switched according to the engine speed, and the motor drive time until the engine start is lengthened to assist the engine drive and improve the fuel consumption. can do.

It is a schematic diagram of the engine which concerns on this Embodiment. It is a functional block diagram of an engine start control system according to the present embodiment. It is a figure which shows an example of the circuit structure of the starter generator which concerns on this Embodiment. It is a graph which shows the engine speed at the time of engine starting, a fuel injection amount, and a vehicle speed in an engine starting control system. It is a flowchart which shows an example of the engine starting control which concerns on this Embodiment.

  Hereinafter, an engine start control system according to the present embodiment will be described with reference to the accompanying drawings. The engine start control system according to the present embodiment is not limited to the configuration shown below, and can be changed as appropriate. The engine start control system may be applied to any vehicle, and can be applied to, for example, a motorcycle, a buggy type automatic tricycle, or an automatic four-wheel vehicle.

  First, a general configuration of a general engine will be described with reference to FIG. FIG. 1 is a schematic diagram of an engine according to the present embodiment. As shown in FIG. 1, the engine 1 is, for example, a direct acting DOHC (Double OverHead Camshaft) engine. The engine 1 includes a crankshaft 10, a cylinder 11, a cylinder head 12, and the like in a crankcase (not shown). A piston 13 is accommodated in the cylinder 11 so as to reciprocate up and down. The crankshaft 10 and the piston 13 are connected by a connecting rod 14. In the engine 1, the crankshaft 10 is rotated via the connecting rod 14 as the piston 13 reciprocates in the vertical direction.

  The internal space of the cylinder head 12 constitutes a combustion chamber 15. The cylinder head 12 is provided with an intake valve 16 and an exhaust valve 17 corresponding to the intake port and the exhaust port. A pair of camshafts 18 are provided corresponding to the intake valve 16 and the exhaust valve 17. A cam chain (not shown) is bridged between the crankshaft 10 and the pair of camshafts 18. The rotation of the crankshaft 10 is transmitted to the pair of camshafts 18 via the cam chain.

  By rotating the pair of camshafts 18, the intake valve 16 and the exhaust valve 17 are reciprocated toward the combustion chamber 15. In this way, the opening / closing timing of each of the intake valve 16 and the exhaust valve 17 is adjusted. A spark plug 19 a that constitutes a part of the ignition device 19 is provided above the combustion chamber 15. The ignition device 19 includes an ignition coil 19b, a high tension cord 19c, and a plug cap 19d in addition to the spark plug 19a.

  The ignition coil 19b is connected to the plug cap 19d via the high tension cord 19c, and the plug cap 19d is attached to the spark plug 19a. The ignition coil 19b amplifies a voltage supplied from a battery (not shown), for example, several hundred times. The high voltage current amplified by the ignition coil 19b is supplied to the spark plug 19a via the high tension cord 19c. Thereby, a spark is generated at the tip of the spark plug 19a. The ignition device 19 ignites the air-fuel mixture in the combustion chamber 15 by igniting at a predetermined timing based on the ignition signal output from the ECU 2.

  The crankshaft 10 is connected to a starter generator 20 provided on the same axis as the crankshaft 10. The starter generator 20 is connected to a battery 22 (see FIG. 2) via an inverter 23 (motor controller 24) (see FIG. 2) described later. The starter generator 20 performs so-called “power running” in which the crankshaft 10 is driven to rotate by receiving power supplied from the battery 22. Further, the starter generator 20 performs so-called “regeneration” in which electric energy is recovered from the rotational energy during the driving of the engine 1.

  As described above, the starter generator 20 has both a function as a starter motor that starts the engine 1 and a function as a generator that generates electric power by driving the engine 1. The starter generator 20 according to the present embodiment has a function of applying a driving force as a motor in an engine low speed region such as when the engine is started or assist driving, and regenerating (power generation) in other engine high speed regions. . Although details will be described later, the inverter 23 (see FIG. 2) connected to the starter generator 20 has two different output torques so that the output torque can be switched according to the engine speed when the crankshaft 10 is rotated. A circuit pattern is provided (a first circuit pattern and a second circuit pattern shown in FIG. 3).

  Various operations in the engine 1 are controlled by the ECU 2. The ECU 2 includes a processor that executes various processes in the engine 1, a memory, and the like. The memory is configured by a storage medium such as a ROM (Read Only Memory) or a RAM (Random Access Memory) according to the application. The memory stores a control program for controlling each part of the engine 1. The ECU 2 determines the state of the vehicle from various sensors provided in the vehicle, and controls ignition timing of the ignition device 19 and drive of the starter generator 20 (motor) when the engine 1 is started.

  By the way, in the conventional engine start control system using the starter generator, the capacity of the starter generator is only secured for the torque necessary for starting the engine. Further, in the conventional starter generator, the engine speed can be increased only to a predetermined speed, and the engine assist has not been performed properly. Therefore, in order to realize further engine assist, it is conceivable to employ a starter generator (motor) that generates higher torque at higher voltage. For example, when a low-rotation type conventional motor used for engine starting is rotated as it is to a high rotation range, it is necessary to increase the applied voltage with a DC-DC converter or the like. As a result, the motor can be driven to the high engine speed range, but the motor becomes larger and the battery capacity increases. For this reason, there was a problem that it was not suitable for a small vehicle.

  From this point of view, in the present embodiment, the starter generator 20 is configured as a winding switching system, and the output torque is switched according to the rotational speed of the engine 1. As a result, it is possible to drive the engine 1 to a high rotation range even with a small starter generator 20 without increasing the output of the starter generator 20. Therefore, it is possible to minimize fuel injection at the time of starting the engine, thereby suppressing fuel consumption and noise to the surroundings.

  Next, the system configuration of the engine start control system according to the present embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram of the engine start control system according to the present embodiment.

  As shown in FIG. 2, the engine start control system 3 includes an ECU 2, a fuel injection device 21, an ignition device 19, a battery 22, an inverter 23, and a starter generator 20. The engine start control system 3 not only simply starts the engine 1 but also stops the engine 1 (see FIG. 1) when the vehicle stops, and the starter generator 20 is operated when a throttle (not shown) is operated. The engine 1 is configured to be driven and restarted.

  ECU2 comprises the engine control apparatus which concerns on this Embodiment. The ECU 2 controls the fuel injection device 21 (fuel injection amount) and the ignition device 19 (ignition timing) according to various parameters such as the vehicle speed, the intake pressure, and the engine speed. The fuel injection device 21 is configured by, for example, fuel injection, and injects fuel at an optimal injection amount, injection time, and timing in response to an instruction from the ECU 2. As described above, the ignition device 19 ignites at an optimal timing in response to an instruction from the ECU 2.

  In addition, the ECU 2 stores engine speed threshold values (first, second, third, and fourth engine speeds, which will be described later), which serve as a determination criterion when drive control of the starter generator 20 is performed. Although details will be described later, the ECU 2 performs combustion injection and ignition control based on the threshold value. A motor controller 24 of the inverter 23 described later switches the motor circuit 30 based on the threshold value and controls driving of the starter generator 20.

  As described above, the battery 22 is connected to the starter generator 20 via the inverter 23. The battery 22 not only supplies electric power to the ECU 2, the inverter 23, and the starter generator 20, but also plays a role of storing electric power generated by the starter generator 20. The inverter 23 converts the current from the battery 22 from direct current to alternating current and supplies it to the starter generator 20. Further, the inverter 23 converts the current from the starter generator 20 from alternating current to direct current and supplies it to the battery 22. The inverter 23 is driven and controlled in response to an instruction from the ECU 2.

  The inverter 23 includes a motor controller 24 that controls the output of the starter generator 20 (motor), a winding switching circuit 25 that switches the motor windings, and a motor circuit 30. The motor controller 24 controls the drive of the starter generator 20 in response to an instruction from the ECU 2 according to the engine speed or the like. The motor circuit 30 will be described later. As described above, the starter generator 20 has a function as a starter motor for starting the engine 1. The starter generator 20 rotates the crankshaft 10 in response to an instruction from the motor controller 24.

  Here, with reference to FIG. 3, a circuit configuration provided in the starter generator according to the present embodiment will be described. FIG. 3 is a diagram showing an example of a circuit configuration of the starter generator according to the present embodiment. 3A shows a circuit diagram of a winding switching type three-phase AC motor, FIG. 3B shows a motor circuit when connected in series, and FIG. 3C shows a motor circuit when connected in parallel. In FIGS. 3B and 3C, only one of the three phases is shown. The circuit configuration provided in the starter generator is not limited to the configuration shown below, and can be changed as appropriate. The starter generator may be configured in any way as long as the main torque can be changed according to the engine speed.

  As shown in FIG. 3, the starter generator 20 (see FIG. 1 or FIG. 2, hereinafter simply referred to as the motor 20) is a three-phase AC motor. In the present embodiment, the motor circuit 30 employs a winding switching method capable of switching between series and parallel. As shown in FIG. 3A, the coils 31 of the respective phases (three phases) of the motor circuit 30 are commonly connected (star connection) at a neutral point 32. The coil 31 includes a first coil 33, a second coil 34, a first switch 35, and a second switch 36.

  Specifically, one end of the first coil 33 is connected to the neutral point 32, and the other end of the first coil 33 is connected to the contact 35 b of the first switch 35 via the contact 36 a of the second switch 36. It is connected. A second switch 36 is connected to one end of the second coil 34, and a first switch 35 is connected to the other end of the second coil 34. Further, the contact 36 b of the second switch 36 is connected to the neutral point 32.

  In the motor circuit 30 configured as described above, the connection between the first coil 33 and the second coil 34 can be switched directly and in parallel by switching the first switch 35 and the second switch 36. For example, as shown in FIG. 3B, the first coil 33 and the second coil 34 are connected in series by bringing the first switch 35 into contact with the contact 35a and bringing the second switch 36 into contact with the contact 36a. The This circuit pattern is defined as a first circuit pattern. In the first circuit pattern, the first coil 33 and the second coil 34 are connected in series, whereby the motor 20 can generate a large driving torque at a low rotation.

  On the other hand, as shown in FIG. 3C, the first coil 35 and the second coil 34 are connected in parallel by bringing the first switch 35 into contact with the contact 35b and bringing the second switch 36 into contact with the contact 36b. The This circuit pattern is defined as a second circuit pattern. In the second circuit pattern, when the first coil 33 and the second coil 34 are connected in parallel, the drive torque of the motor 20 is reduced, but the back electromotive force of the motor 20 is suppressed. Therefore, it is possible to drive the motor 20 to a high rotation even at a low voltage. 3B and 3C show the switching of the circuit for one phase of the three phases, it is assumed that the switching operation is similarly performed for the other two phases.

  According to the motor circuit 30 according to the present embodiment, the connection between the first coil 33 and the second coil 34 is configured to be switchable in series and in parallel, so that necessary driving is appropriately performed according to the engine speed. Torque can be generated. For example, when the engine 1 is in a non-rotating state to a relatively low rotating state, the motor circuit 30 is switched to the first circuit pattern so that the first coil 33 and the second coil 34 are connected in series. As a result, a relatively large driving torque is generated in the motor 20 so as to counter the inertia of the crankshaft 10 (see FIG. 1 or 2). Therefore, driving of the motor 20 in the low rotation range can be realized.

  On the other hand, when the engine speed exceeds a predetermined speed, the motor circuit 30 is switched to the second circuit pattern so that the first coil 33 and the second coil 34 are connected in parallel. As a result, a low driving torque is generated in the motor 20 so as to keep the generation of the counter electromotive force low. Therefore, driving of the motor 20 in the high rotation range can be realized. In this way, by changing the output torque of the motor 20 according to the engine speed, the engine 1 can be used in a wide range of rotational speeds from a non-rotating state to a high rotational speed range even for a small and low-voltage motor 20. It becomes possible to assist.

  Next, with reference to FIG. 4, the state from when the engine is stopped until the engine is started until the engine speed at which the vehicle can travel will be described. FIG. 4 is a graph showing the engine speed, the fuel injection amount, and the vehicle speed when starting the engine in the engine start control system. In FIG. 4, the horizontal axis indicates time, and the vertical axis indicates engine speed (crankshaft speed), fuel injection amount, or vehicle speed. FIG. 4A is a graph showing the engine speed and the like in the engine start control system according to the comparative example, and FIG. 4B is a graph showing the engine speed and the like in the engine start control system of the present application. In the graph, the engine speed is indicated by a solid line, the fuel injection amount is indicated by a one-dot chain line, and the vehicle speed is indicated by a two-dot chain line.

  Although FIG. 4 illustrates a case where the engine is started from a state where the engine is completely stopped, the present invention is not limited to this. The engine start control system may be configured to restart from a state where the engine is idling stopped, for example. The engine start control system described below is applied to a vehicle equipped with an automatic clutch such as a centrifugal clutch. In this case, when the engine reaches a predetermined rotational speed (for example, 3500 rpm), the automatic clutch is engaged and the vehicle can be started.

  As shown in FIG. 4A, in the comparative example, when the engine start control is started, the crankshaft 10 is driven to rotate by driving the motor 20 (starter generator 20) (see FIG. 1), and the engine speed is increased. Is gradually increased. Fuel injection and ignition control are started when the engine speed exceeds a predetermined speed (for example, 1500 rpm) after a time T1 from the start of driving of the motor 20, while the driving of the motor 20 is stopped thereafter.

  The engine speed is gradually increased by fuel injection and ignition control. Then, after time T2 from when the motor 20 starts to be driven, when the engine speed exceeds 3500 rpm, the automatic clutch is engaged and the vehicle starts to travel. While the vehicle speed (vehicle speed) is increasing, the engine speed and the fuel injection amount are increasing. After the vehicle speed reaches a predetermined value (for example, 50 km / h), when the vehicle continues to run at a constant speed, the engine speed settles at a constant value. On the other hand, the fuel injection amount reaches a peak (maximum amount) before the vehicle speed reaches 50 km / h. Then, after the vehicle speed has settled to a certain value, the fuel injection amount gradually decreases.

  In contrast to the comparative example, in the present embodiment, as shown in FIG. 4B, when the engine start control is started, the motor 20 is driven and the engine speed is gradually increased. At this time, the motor 20 is switched to the first circuit pattern, and a large driving torque is generated in the motor 20 in a low rotation range (for example, 0 to 1000 rpm). When the engine speed exceeds 1000 rpm (first speed), the motor 20 is switched to the second circuit pattern. Thereby, the motor 20 can be driven in a high rotation range (for example, 1000 to 4000 rpm).

  The engine speed is gradually increased by the motor 20, and fuel injection and ignition control are started when the engine speed exceeds, for example, 3400 rpm (third speed) after a time T3 from when the motor 20 starts to drive. Is done. The engine speed is gradually increased by fuel injection and ignition control. Then, after the time T4 from when the motor 20 starts to be driven, the automatic clutch is engaged when the engine speed exceeds 3500 rpm (second speed), and the vehicle starts to travel.

  While the vehicle speed (vehicle speed) is increasing, the engine speed and the fuel injection amount are increasing. When the engine speed becomes, for example, 4000 rpm (fourth speed) or more, the driving of the motor 20 is stopped, and thereafter, the engine speed is increased only by fuel injection and ignition control. As in the comparative example, when the vehicle continues to run at a constant speed after the vehicle speed reaches a predetermined value (for example, 50 km / h), the engine speed settles at a constant value. On the other hand, the fuel injection amount reaches a peak (maximum amount) before the vehicle speed reaches 50 km / h. Then, after the vehicle speed has settled to a certain value, the fuel injection amount gradually decreases.

  Thus, in the present embodiment, the torque of the motor 20 is adjusted according to the engine speed, and the drive time of the motor 20 is made as long as possible until the vehicle starts to start. In the comparative example, fuel injection or the like is started when the engine speed exceeds 1500 rpm, whereas in this embodiment, fuel injection is started when the engine speed exceeds 3400 rpm. That is, in this embodiment, the time T3 until the start of fuel injection is longer than the time T1 until the start of fuel injection in the comparative example. For this reason, the fuel injection amount until the vehicle starts can be reduced, and the fuel efficiency is improved.

  Further, in the low speed range, it is possible to increase the engine speed suitable for vehicle start faster by driving the motor 20 than by increasing the engine speed by fuel injection or the like. Therefore, the time T4 until the vehicle start in the present embodiment, that is, the time until the clutch-in can be shortened compared to the time T2 until the vehicle start in the comparative example. In addition, at the timing when the vehicle starts to start, by performing both fuel injection and motor drive, the motor 20 can assist the engine drive even when high torque is required due to the engagement of the automatic clutch. .

  Next, engine start control according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing an example of engine start control according to the present embodiment. The control described below is executed by the ECU 2 unless otherwise specified.

  As shown in FIG. 5, when the control is started, the vehicle speed is first measured to determine whether or not the vehicle is stopped (step ST1). For example, when the vehicle speed is not 0 km / h (step ST1: No), the operation of step ST1 is performed again. On the other hand, when the vehicle speed is 0 km / h (step ST1: Yes), the time is counted, and it is determined whether or not the vehicle has been stopped for a predetermined time (step ST2). Note that the vehicle speed that serves as a reference for determining whether to stop the vehicle is not limited to 0 km / h, and may be set within a predetermined range as long as the vehicle can easily stop (for example, 0 to 5 km / h). h).

  When the stop state of the vehicle is not maintained for a predetermined time (step ST2: No), the operation returns to step ST1. On the other hand, when the stop state of the vehicle is maintained for a predetermined time (step ST2: Yes), the engine (see FIG. 1) enters an idle stop state (step ST3). Note that the predetermined time, which is a criterion for maintaining the stopped state, can be changed as appropriate.

  When the idle stop state is set, it is determined whether or not a throttle operation has been performed (step ST4). If there is no throttle operation (step ST4: No), the operation of step ST4 is performed again. On the other hand, if there is a throttle operation (step ST4: Yes), the motor controller 24 (see FIG. 2) switches the motor circuit 30 to the first circuit pattern and drives the motor 20 (step ST5). Thereby, the crankshaft 10 (refer FIG. 1) is rotationally driven, and an engine speed is raised gradually. The ECU 2 determines whether or not the throttle operation is performed, for example, based on the output of the throttle position sensor.

  Next, it is determined whether the engine speed (Ne) has exceeded a predetermined speed (first speed) (step ST6). Here, the first rotation speed is 1000 rpm. When the engine speed does not exceed 1000 rpm (step ST6: No), the operation of step ST6 is performed again. On the other hand, when the engine speed exceeds 1000 rpm (step ST6: Yes), the motor controller 24 switches the motor circuit 30 to the second circuit pattern and drives the motor 20 (step ST7). Thereby, it becomes possible to drive the motor 20 to a higher rotation range.

  The engine speed is further increased, and then it is determined whether or not the engine speed (Ne) has exceeded a predetermined speed (third speed) (step ST8). Here, the third rotation speed is 3400 rpm. When the engine speed does not exceed 3400 rpm (step ST8: No), the operation of step ST8 is performed again. On the other hand, when the engine speed exceeds 3400 rpm (step ST8: Yes), fuel injection and ignition control are started (step ST9). Thereafter, the engine speed is increased by driving the motor and fuel injection.

  Next, it is determined whether or not the engine speed (Ne) has exceeded a predetermined speed (second speed) (step ST10). Here, the second rotational speed is 3500 rpm. When the engine speed does not exceed 3500 rpm (step ST10: No), the operation of step ST10 is performed again. On the other hand, when the engine speed exceeds 3500 rpm (step ST10: Yes), the motor controller 24 gradually attenuates the driving force of the motor 20 (step ST11). At this timing, the automatic clutch is engaged and the vehicle starts to start. Thus, the consumption of electric power can be suppressed by gradually attenuating the driving force of the motor 20.

  When the vehicle starts to start and the engine speed is further increased, it is next determined whether or not the engine speed (Ne) exceeds a predetermined speed (fourth speed) (step ST12). Here, the 4th rotation speed shall be 4000 rpm. When the engine speed does not exceed 4000 rpm (step ST12: No), the operation of step ST12 is performed again. On the other hand, when the engine speed is 4000 rpm or more (step ST12: Yes), the motor controller 24 completes driving by the motor 20 (step ST13). Thereafter, the engine 1 is driven only by fuel injection and ignition control.

  After the engine speed reaches 4000 rpm or more, the function of the motor 20 shifts to regeneration (power generation) (step ST14), and the battery 22 is charged. At this time, the motor circuit 30 is switched to the second circuit pattern, and the motor 20 performs regeneration under the second circuit pattern. Then, the engine start control ends.

  As described above, according to the present embodiment, when the engine 1 is started from a stopped state, the motor 20 is driven by switching between the first circuit pattern and the second circuit pattern, thereby being driven relatively. The engine speed can be increased only by the motor 20 from a low engine speed range (first engine speed) that requires torque to a high engine speed range (second engine speed) in which the drive torque is suppressed. Then, the engine is started by starting the fuel injection control and the ignition control from the third rotational speed. Thus, by switching the output torque of the motor 20 and increasing the motor drive time until the engine is started, the time until the engine is started can be shortened. On the other hand, since fuel injection time until engine start can be shortened, fuel consumption and noise to the surroundings can be suppressed. As described above, driving of the engine 1 can be assisted to improve fuel consumption.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the embodiment described above, the engine 1 is started by the starter generator 20 in which the starter motor and the generator are integrated. However, the present invention is not limited to this configuration. A starter motor and a generator may be provided separately, and the engine 1 may be started with the starter motor.

  In the above-described embodiment, the motor circuit 30 is configured to switch the circuit pattern with the switches (the first switch 35 and the second switch 36), but is not limited to this configuration. The switching of the circuit pattern may be controlled by, for example, a relay or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

  In the above embodiment, the ECU 2 is configured to start the fuel injection control and the ignition control when the engine speed exceeds the third speed (3400 rpm). However, the present invention is not limited to this configuration. The ECU 2 may be configured to start one of fuel injection control and ignition control when the engine speed exceeds the third speed.

  In the above-described embodiment, the circuit of the starter generator 20 is a circuit configured with a so-called three-phase Y-type connection including a series-parallel switching unit, but is not limited to this configuration. The circuit of the starter generator 20 may be constituted by an intermediate tap circuit, for example.

  Moreover, in said embodiment, although it was set as the structure which made ECU2 and the inverter 23 into a different body, it is not limited to this structure. The ECU 2 and the inverter 23 may be integrated.

  As described above, the present invention has an effect that the driving of the engine can be assisted to improve the fuel consumption, and is particularly useful for an engine start control system and a vehicle that assists the start of the engine with a motor. It is.

1 Engine 10 Crankshaft 2 ECU (Engine Control Device)
20 Starter generator (motor)
24 motor controller 3 engine start control system 30 motor circuit (first circuit and second circuit)

Claims (3)

An engine start control system comprising: a motor that rotates a crankshaft; a motor controller that controls output of the motor; and an engine control device that performs fuel injection control and / or ignition control.
The motor includes a first circuit pattern and a second circuit pattern having different output torques,
The motor controller drives the motor using the first circuit pattern until the engine rotational speed reaches the first rotational speed, and when the engine rotational speed exceeds the first rotational speed, the second circuit Switch to a pattern and drive the motor until a second rotational speed greater than the first rotational speed is reached,
The engine control device starts fuel injection control and / or ignition control when the engine speed becomes equal to or greater than a third speed that is greater than the first speed and smaller than the second speed. An engine start control system. A vehicle comprising the engine start control system according to claim 1 or 2,
A vehicle comprising an automatic clutch that is engaged when the engine rotational speed is equal to or higher than a second rotational speed. The vehicle according to claim 2,
The motor controller attenuates the driving force of the motor when the second rotational speed is exceeded, and completes driving by the motor when the rotational speed exceeds a fourth rotational speed that is greater than the second rotational speed. Vehicle.

Images