WO2017217501A1

WO2017217501A1 - Engine starting system and starter

Info

Publication number: WO2017217501A1
Application number: PCT/JP2017/022171
Authority: WO
Inventors: 卓郎中岡; 彰宏井村; 満柴沼; 祐輝久保; 稔岡宮; 卓水野
Original assignee: 株式会社デンソー
Priority date: 2016-06-16
Filing date: 2017-06-15
Publication date: 2017-12-21

Abstract

In the present invention, a first control device 8 comprises a starting control unit 17 and an overrun determination unit 18. The starting control unit 17 activates a second starter 7 to begin cranking, and thereafter stops the operation of the second starter at a prescribed timing and begins motor operation of a first starter 5. After cranking has been begun by the second starter, the overrun determination unit 18 determines whether a prescribed overrun condition formula has been fulfilled. When the overrun condition formula has been fulfilled before an engine 2 overruns the initial compression top dead center, the starting control unit stops the operation of the second starter and begins motor operation of the first starter, regardless of whether the engine has overrun the initial compression top dead center.

Description

Engine start system and starter

This disclosure relates to a technique for starting an engine using first and second starters.

For example, there is known an engine start technique for starting an engine using a motor generator having a power generation function and a motor function in combination with a pinion dive starter (see Patent Document 1).
In this technique, after starting the starter and starting cranking of the engine, the timing for stopping the starter and the timing for starting the motor operation of the motor generator are set as follows. The timing to stop the starter is set after passing through the compression top dead center (TDC) of the engine that occurs first after the start of fuel injection. The timing of starting the motor operation of the motor generator is set before passing the first TDC and before reaching the next TDC.

Japanese Patent No. 5875664

In the above technique, the timing for stopping the starter is set after passing the first TDC after the start of fuel injection. However, in practice, fuel injection is not started unless cylinder discrimination by the crank angle sensor of the engine is completed. That is, several crankings are required before fuel injection is started. In this case, re-engagement of the one-way clutch occurs before the starter is stopped. Therefore, it cannot always be said that the starting sound generated during cranking can be reduced. When the one-way clutch is reconnected, the driving / driven state is switched between the ring gear and the pinion. The generation of the starting sound during cranking is caused by such switching between driving / driven. Specifically, the starting sound is a gear collision sound generated by switching between driving / driven and a meshing sound between the ring gear and the pinion.

In the above technique, the starter operation is stopped after passing the first TDC after the start of fuel injection. Therefore, it is difficult to shorten the starter driving time. Thereby, the time for generating the meshing sound between the ring gear and the pinion is lengthened.
The present disclosure provides an engine start system that can reduce a start sound generated during cranking.

An engine start system that is an aspect of the technology of the present disclosure includes a first starter, a second starter, and a control device. The first starter is connected to the crankshaft of the engine and rotationally drives the crankshaft. The second starter cranks the engine by rotationally driving a ring gear connected to the crankshaft. The control device controls operations of the first starter and the second starter.
The first starter is a motor generator having both functions of a generator and an electric motor. The second starter is a pinion dive starter. The second starter includes a motor, a pinion, a one-way clutch, and a solenoid device. The motor rotates upon receiving power. The pinion moves in the axial direction and meshes with the ring gear. The one-way clutch can transmit torque in only one direction from the motor side to the pinion side, and interrupts torque transmission from the pinion side to the motor side. The solenoid device has a function of moving the pinion in the axial direction and a function of starting / stopping (on / off) power supply to the motor.

The required overpass torque means a torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the first starter. The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque. The overpass conditional expression defines a magnitude relationship in which the required overpass torque is larger than the engine start torque (required overpass torque> magnitude relationship represented by the engine start torque). The control device includes a start control unit and an overpass determination unit. The start control unit starts the cranking by starting the second starter in response to an engine start request, stops the operation of the second starter at a predetermined timing, and operates the motor of the first starter. To start. The transit determination unit determines whether or not the transit condition is satisfied after cranking is started by the second starter. The start control unit controls the operation of the second starter regardless of whether or not the engine has passed the first compression top dead center when the passing condition is satisfied before the engine has passed the first compression top dead center. Stop and start motor operation of the first starter.

The engine start system according to the present disclosure determines as follows when the passing condition formula is satisfied before cranking over the first compression top dead center after cranking is started by the second starter. The engine start system determines that the engine can get over the first compression top dead center even if the second starter is stopped when the overtaking conditional expression is satisfied. Therefore, when the overtaking conditional expression is satisfied, the operation of the second starter can be stopped before the engine gets over the first compression top dead center. Thereby, the engine start system of this indication can make the timing which stops operation of the 2nd starter (pinion dive starter) compared with a prior art. As a result, the driving time of the second starter can be shortened, and the meshing noise between the pinion and the ring gear can be reduced.

It is a lineblock diagram of the engine starting system concerning a 1st embodiment. It is a flowchart which shows the control procedure at the time of engine starting which concerns on 1st Embodiment. It is a figure which shows the output restriction map which concerns on 1st Embodiment. It is a figure which shows the output restriction map which concerns on 1st Embodiment. It is a graph which shows transition of the rotation speed and torque concerning a 1st embodiment, and a time chart which shows ON / OFF timing of the 1st starter and the 2nd starter. It is a graph which shows transition of the rotation speed and torque concerning a 2nd embodiment, and a time chart which shows ON / OFF timing of the 1st starter and the 2nd starter. It is a block diagram of the engine starting system which concerns on 3rd Embodiment. It is a block diagram of the engine starting system which concerns on 4th Embodiment. It is a block diagram of the engine starting system which concerns on 5th Embodiment. It is a flowchart which shows the control procedure at the time of the engine starting which concerns on 5th Embodiment. It is a graph which shows transition of rotation speed and torque concerning a 7th embodiment, and a time chart which shows ON / OFF timing of the 1st starter and the 2nd starter. It is a graph which shows transition of rotation speed and torque concerning an 8th embodiment, and a time chart which shows ON / OFF timing of the 1st starter and the 2nd starter. It is the graph which shows transition of the rotation speed and torque which concern on 9th Embodiment, and the time chart which shows the on / off timing of a 1st starter and a 2nd starter.

DETAILED DESCRIPTION Embodiments for carrying out the technology of the present disclosure will be described in detail with reference to the drawings.

[First Embodiment]
The engine start system 1 of this embodiment is provided with the 1st starter 5, the 2nd starter 7, and the 1st control apparatus 8, as illustrated in FIG. The first starter 5 is connected to the crankshaft 3 of the engine 2 via a belt 4. The second starter 7 can be connected to a ring gear 6 attached to the crankshaft 3. The first control device 8 controls the operations of the first starter 5 and the second starter 7. The first control device 8 has a built-in microcomputer, for example. The microcomputer includes a CPU that realizes a control function and an arithmetic function, a storage device (memory) of ROM and RAM, an input / output device of I / O, and the like. The storage device includes a non-transitional tangible recording medium. Signals (detection information) indicating detection values are input to the first control device 8 from various detectors that detect the state of the engine 2. The first control device 8 outputs a signal (control information) for controlling the engine 2 based on the input signal.

The first starter 5 is a motor generator having functions of both a generator and an electric motor. The first starter 5 includes a second control device 9 different from the first control device 8, and the operation is controlled by the second control device 9. Note that, similarly to the first control device 8, the second control device 9 includes a microcomputer including a CPU, a ROM, a RAM, an I / O, and the like. A signal indicating a control command is input from the first controller 8 to the second controller 9. Signals (detection information) indicating detection values are input to the second control device 9 from various detectors that detect the state of the first starter 5 and the like. The second control device 9 outputs a signal (control information) for controlling the first starter 5 based on these input signals. The second control device 9 includes an inverter circuit for adjusting the voltage and frequency applied to the first starter 5. The microcomputer of the second control device 9 can arbitrarily control the rotation speed of the first starter 5 by outputting a signal to the inverter circuit.

The second starter 7 pushes the pinion 10 in the A direction (right direction in FIG. 1) that is the axial direction, and meshes with the ring gear 6. Then, the second starter 7 transmits the torque generated in the motor 11 to the pinion 10 and rotationally drives the ring gear 6. Thus, the second starter 7 is a well-known pinion dive starter. The second starter 7 includes the following clutch 12 and electromagnetic switch 13 and the like.
The clutch 12 is a one-way clutch that transmits torque in only one direction. The clutch 12 transmits torque generated in the motor 11 from the motor side to the pinion side. On the other hand, the clutch 12 blocks torque transmission from the pinion side to the motor side.
The electromagnetic switch 13 includes a solenoid 14 and a plunger 15. The solenoid 14 generates an electromagnetic force when energized. The plunger 15 is attracted in the B direction (left direction in FIG. 1) by the electromagnetic force of the solenoid 14. The electromagnetic switch 13 moves the pinion 10 in the A direction (the right direction in FIG. 1) in conjunction with the movement of the plunger 15. The electromagnetic switch 13 opens and closes the main contact 16 provided on the power supply line of the motor 11 to start / stop (on / off) power supply to the motor 11.

The first control device 8 has functions of a start control unit 17 and an overriding determination unit 18. The start control unit 17 controls the operations of the first and

second starters

5 and 7 when the engine 2 is started. The overpass determining unit 18 determines whether or not a pass over conditional expression described later is satisfied after cranking of the engine 2 is started. In addition, as will be described later, the start control unit 17 and the transit determination unit 18 are realized (by software) by the CPU executing a program stored in a storage device (memory) included in the microcomputer, for example. Also good. The implementation methods of the start control unit 17 and the overpass determination unit 18 are not limited to this. The start control unit 17 and the overpass determination unit 18 may be realized (by hardware) by combining electronic circuits such as ICs.
Hereinafter, the control procedure at the time of engine start executed by the first control device 8 of the present embodiment will be described with reference to the flowchart illustrated in FIG. The following steps S1 to S8 correspond to S1 to S8 attached to each process of the flowchart illustrated in FIG.

The first control device 8 determines whether or not a start request for the engine 2 has been input (step S1). The engine 2 start request is output at the following times. For example, after the idling stop is executed, when the driver performs an operation of loosening the brake pedal, or when the operation of switching the shift lever from the N range (neutral) to the D range (driving) is performed. . The idling stop is a known technique for automatically stopping the engine 2 when the vehicle is temporarily stopped at an intersection or the like. The first control device 8 repeats the process of step S1 until a start request for the engine 2 is input (step S1: NO). On the other hand, when the start request for the engine 2 is input (step S1: YES), the first control device 8 proceeds to the process of step S2.

The first control device 8 performs the following start control on the second starter 7 by the start control unit 17. Specifically, the start control unit 17 outputs an on signal (start signal) to a relay 19 (see FIG. 1) provided in the energization line of the solenoid 14 and turns on the electromagnetic switch 13 to thereby perform the second start. The machine 7 is activated (step S2). When the relay 19 is turned on, the electromagnetic switch 13 energizes the solenoid 14 from the battery 20 to generate electromagnetic force. In the electromagnetic switch 13, the plunger 15 is attracted by the electromagnetic force and moves in the B direction (left direction in FIG. 1). By such an operation of the electromagnetic switch 13, the pinion 10 is pushed out in the A direction (the right direction in FIG. 1) and meshes with the ring gear 6. Then, the main contact 16 is closed, and electric power is supplied from the battery 20 to the motor 11. As a result, the torque of the motor 11 is transmitted to the pinion 10 via the clutch 12 and rotationally drives the ring gear 6.

The first control device 8 determines whether or not the engine 2 has passed the first compression top dead center (first TDC) (step S3). Whether the engine 2 has passed the first TDC can be determined based on the following information. For example, the engine speed can be detected by an existing crank angle sensor (not shown) (for example, the engine speed can be calculated based on the crank angle detected by the crank angle sensor). Further, the determination may be made based on at least one information of the rotation speed, torque, and current of the first starter 5 connected to the crankshaft 3. If the engine 2 has not overtaken the first TDC (step S3: NO), the first control device 8 proceeds to the process of step S4. On the other hand, when the engine 2 has passed the first TDC (step S3: YES), the first control device 8 proceeds to the process of step S5.

The first control device 8 determines whether or not the overpass conditional expression is satisfied by the overpass determining unit 18 (step S4).
The overpass conditional expression is a predetermined condition for determining whether or not the engine 2 can get over the first TDC when the operation of the second starter 7 is stopped before the engine 2 gets over the first TDC. An expression with a defined condition. Specifically, the overtaking conditional expression is expressed as “necessary overpassing torque> engine starting torque”. Therefore, the overriding determination unit 18 determines that the overriding is possible when this magnitude relationship is established (when the necessary overpass torque is greater than the engine start torque). The required overpass torque is a torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine 2 from the start of cranking and the drive torque that can be output by the motor operation of the first starter 5. The engine starting torque is a torque obtained by adding the compression torque of the engine 2 and the friction torque.

In the present embodiment, a known value that is grasped in advance as the compression torque and the friction torque of the engine 2 is input to the overpass determination unit 18. Then, the overpassing determination unit 18 calculates the drive torque that can be output from the first starter 5 based on the output restriction map (data map) of the second control device 9. 3A and 3B illustrate an output restriction map according to the present embodiment. As illustrated in FIGS. 3A and 3B, the output restriction map is data indicating a correlation between the drive torque that can be output from the first starter 5 and the engine speed. The drive torque that can be output from the first starter 5 is calculated by applying the engine speed to the output restriction map.

The rotational speed value Nec illustrated in FIG. 3A is a rotational speed that can be switched from cranking by the second starter 7 to cranking by the first starter 5.
Therefore, before the engine speed reaches Nec, the output restriction map may be set as follows in order to prevent the overtaking conditional expression from being satisfied. As illustrated in FIG. 3B, in the output restriction map, the numerical value of the drive torque may be set to zero in a range where the engine speed is equal to or less than Neu, which is slightly larger than Nec.

Further, the rotational torque obtained from the kinetic energy stored in the engine 2 can be calculated from the inertia moment of the rotating system including the crankshaft 3 and the ring gear 6 and the engine speed. Therefore, by inputting a known value to the inertia moment of the rotating system, the engine speed that can be overridden can be calculated.
As described above, the pass-over determination unit 18 can determine whether or not the pass-over conditional expression is satisfied using the engine speed that can be used as a determination condition. That is, when the engine speed that can be detected by the crank angle sensor or the like exceeds the engine speed that can be passed over, the passing-over conditional expression is established.
The first control device 8 proceeds to the process of step S5 when the overtaking conditional expression is satisfied (step S4: YES). The first control device 8 returns to the process of step S3 when the passing over conditional expression is not satisfied (step S4: NO).

The first control device 8 performs the following stop control on the second starter 7 by the start control unit 17. Specifically, the start control unit 17 outputs an off signal (stop signal) to the relay 19 to turn off the electromagnetic switch 13, thereby stopping the operation of the second starter 7 (step S5). When the electromagnetic switch 13 is turned off, in the second starter 7, the pinion 10 is disengaged from the ring gear 6 and the main contact 16 is opened, and the power supply from the battery 20 to the motor 11 is stopped. In the execution of step S5, the relay 19 functions as a stop signal receiving unit that receives a stop signal for stopping the operation of the second starter 7.

The first control device 8 performs the following operation control on the first starter 5 by the start control unit 17. Specifically, the start control unit 17 outputs a drive command (start signal) to the second control device 9 and starts the motor operation of the first starter 5 (step S6). The timing for starting the motor operation of the first starter 5 is before the engine 2 gets over the first TDC. For example, as illustrated in the time chart of FIG. 4, the timing is the same as when the operation of the second starter 7 is stopped. In addition, in execution of step S6, the 2nd control apparatus 9 functions as a start signal receiving part which receives the start signal which starts the motor operation | movement of the 1st starter 5. FIG.

The first control device 8 determines whether or not the engine 2 has completely exploded (step S7). The determination as to whether or not the engine 2 has completely detonated can be made, for example, when the engine speed exceeds a preset complete explosion speed and it is determined that the engine 2 has completely detonated. Until the engine 2 is completely exploded (step S7: NO), the process of step S7 is repeated. On the other hand, if it is determined that the engine 2 has exploded completely (step S7: YES), the first control device 8 proceeds to the process of step S8.
The first control device 8 controls the first starter 5 by the start control unit 17 as follows. Specifically, the start control unit 17 outputs a stop command to the second control device 9 to stop the motor operation of the first starter 5 (step S8). The first starter 5 is connected to the crankshaft 3 via the belt 4. Therefore, the first starter 5 functions as a generator after stopping the motor operation.

〔effect〕
As illustrated in FIG. 4, the engine start system 1 of the present embodiment starts up the second starter 7 and starts cranking. After the engine 2 gets over the first TDC, Once established, control is performed as follows. For example, the engine start system 1 stops the operation of the second starter 7 and starts the motor operation of the first starter 5 at the timing when the passing-over conditional expression is satisfied (t1). That is, the engine start system 1 performs the cranking by switching from the second starter 7 to the first starter 5. FIG. 4 exemplifies a graph showing fluctuations in the engine rotational speed Ne, the motor rotational speed Nm of the second starter 7, and the engine starting torque Te (≈compression torque + friction torque). Moreover, the time chart which shows the on / off timing of the 1st starter 5 and the 2nd starter 7 is illustrated. The motor rotation speed Nm is a rotation speed converted into the rotation speed of the crankshaft 3 from the gear ratio between the pinion 10 and the ring gear 6.
Thereby, the engine start system 1 of this embodiment can make the timing which stops operation | movement of the 2nd starter 7 earlier compared with a prior art. As a result, the driving time of the second starter 7 (the time during which the pinion 10 is engaged with the ring gear 6) is shortened. Therefore, the meshing sound at the time of cranking can be reduced.

Hereinafter, other embodiments of the technology of the present disclosure will be described.
In the following description, parts and configurations common to the first embodiment are assigned the same reference numerals as those in the first embodiment, and detailed description thereof is omitted (refer to the first embodiment).
[Second Embodiment]
The present embodiment is a first case in which the engine 2 gets over the first TDC (first compression top dead center) without satisfying the overtaking conditional expression. Specifically, in this embodiment, as illustrated in FIG. 5, the operation of the second starter 7 is stopped and the motor operation of the first starter 5 is started before the clutch coupling timing. The timing for starting the motor operation of the first starter 5 can be set to any one of three patterns as illustrated in the time chart of FIG. Specifically, (1) before the timing of stopping the operation of the second starter 7, (2) the same as the timing of stopping the operation of the second starter 7, (3) the operation of the second starter 7 It can be set to either after the stop timing. In either case, it is before the clutch engagement timing.

The clutch engagement timing is a timing at which the clutch 12 is estimated to be reconnected when the second starter 7 continues cranking. This clutch coupling timing is a timing at which the motor speed of the second starter 7 catches up with the engine speed after the clutch 12 is disengaged after the engine 2 gets over the first TDC. Therefore, it can be estimated by monitoring at least the engine speed.
In the present embodiment, the operation of the second starter 7 is stopped before the clutch engagement timing even when the engine 2 has passed the first TDC without satisfying the overtaking conditional expression. Thereby, in this embodiment, the recombination of the clutch 12 does not occur. As a result, there is no generation of gear collision noise associated with the re-engagement of the clutch 12. Therefore, it is possible to reduce the starting sound generated during cranking.

In this embodiment, the motor operation of the first starter 5 is started before the clutch coupling timing. Thereby, in this embodiment, even if the timing which stops operation | movement of the 2nd starter 7 is somewhat delayed, the clutch 12 does not rejoin. As a result, generation of gear collision noise can be avoided. Furthermore, in this embodiment, when the timing of starting the motor operation of the first starter 5 is (3), it is necessary to supply power to both the first starter 5 and the second starter 7 at the same time. Absent. That is, when the timing for starting the motor operation of the first starter 5 is set after the timing for stopping the operation of the second starter 7, both the first starter 5 and the second starter 7 are set. There is no need to supply power at the same time. Thus, in this embodiment, when the timing for starting the motor operation of the first starter 5 is (3), a large instantaneous power is not required when starting the motor operation of the first starter 5. . Thereby, the instantaneous interruption of the battery 20 can be prevented.

[Third Embodiment]
In the present embodiment, as illustrated in FIG. 6, the second control device 9 includes functions of a start control unit 17 and a ride-over determination unit 18. In addition, the control procedure at the time of engine start of this embodiment is the same as that of the first embodiment. Therefore, the description is abbreviate | omitted with reference to 1st Embodiment (FIG. 2).

[Fourth Embodiment]
In the present embodiment, as illustrated in FIG. 7, the second control device 9 includes functions of a start control unit 17 and a ride-over determination unit 18. In this embodiment, a command for the relay 19 (a command for the second starter 7) is issued from the second control device 9 via the first control device 8. In addition, the control procedure at the time of engine start of this embodiment is the same as that of the first embodiment. Therefore, the description is abbreviate | omitted with reference to 1st Embodiment (FIG. 2).

[Fifth Embodiment]
This embodiment is an example in the case of using a tandem solenoid starter for the second starter 7.
The electromagnetic switch 13 of the second starter 7 includes first and

second solenoids

22 and 23 as illustrated in FIG. The first solenoid 22 is a solenoid for pushing out the pinion 10. The second solenoid 23 is a solenoid for opening and closing the main contact 16. The operations of the first and

second solenoids

22 and 23 are independently controlled by the first control device 8.
Hereinafter, the control procedure at the time of engine start executed by the first control device 8 of the present embodiment will be described with reference to the flowchart illustrated in FIG. 9. A detailed description of processing (steps) common to the first embodiment will be omitted (see FIG. 2 of the first embodiment).

The first control device 8 determines whether or not a start request for the engine 2 has been input (step S11).
The first control device 8 performs the following start control on the second starter 7 by the start control unit 17. Specifically, the start control unit 17 outputs an ON signal to the first and second relays 24 and 25 (see FIG. 8) and energizes the first and

second solenoids

22 and 23 to thereby generate the second signal. The starter 7 is activated (step S12). When the first relay 24 is turned on, the first solenoid 22 is energized from the battery 20 to generate electromagnetic force. In the first solenoid 22, the first plunger 26 is attracted by the electromagnetic force and moves in the B direction (left direction in FIG. 8). Further, when the second relay 25 is turned on, the second solenoid 23 is energized from the battery 20 to generate an electromagnetic force. In the second solenoid 23, the second plunger 27 is attracted by the electromagnetic force and moves in the C direction (the right direction in FIG. 8). Thus, the pinion 10 is pushed out in the A direction (right direction in FIG. 8) by the operation of the first solenoid 22 and meshes with the ring gear 6. Then, the operation of the second solenoid 23 closes the main contact 16, and power is supplied from the battery 20 to the motor 11. As a result, the torque of the motor 11 is transmitted to the pinion 10 via the clutch 12 and rotationally drives the ring gear 6.

The first control device 8 determines whether or not the engine 2 has passed the first TDC (first compression top dead center) (step S13).
The first control device 8 determines whether or not the overpass conditional expression is satisfied by the overpass determining unit 18 (step S14).
The first control device 8 outputs an off signal to the first relay 24 by the start control unit 17, and stops energization of the first solenoid 22 (step S15). When the energization of the first solenoid 22 is stopped, the pinion 10 is detached from the ring gear 6 in the second starter 7.
The first control device 8 controls the first starter 5 by the start control unit 17 as follows. Specifically, the start control unit 17 outputs a drive command to the second control device 9 and starts the motor operation of the first starter 5 (step S16). Further, the first control device 8 outputs an off signal to the second relay 25 by the start control unit 17 to stop energization of the second solenoid 23. As a result, in the second starter 7, the main contact 16 is opened, and the power supply from the battery 20 to the motor 11 is stopped. Thereby, the operation of the second starter 7 is stopped.
The first control device 8 determines whether or not the engine 2 has completely exploded (step S17).
The first control device 8 controls the first starter 5 by the start control unit 17 as follows. Specifically, the start control unit 17 outputs a stop command to the second control device 9 to stop the motor operation of the first starter 5 (step S18).

In the present embodiment, when the operation of the second starter 7 is stopped, the following control is performed. Specifically, before the power supply to the motor 11 is stopped by stopping the energization to the second solenoid 23, the energization to the first solenoid 22 is stopped and the pinion 10 is detached from the ring gear 6. Thereby, in this embodiment, the recombination of the clutch 12 does not occur substantially. Therefore, in this embodiment, after the drive command for starting the motor operation of the first starter 5 is output to the second controller 9, the motor operation of the first starter 5 is actually started. Even if there is a time difference between the start time and the start time, the starting sound generated during cranking can be reduced.

[Sixth Embodiment]
The present embodiment is an example in the case where the timing for stopping the operation of the second starter 7 and the timing for starting the motor operation of the first starter 5 are changed according to the initial crank angle. The initial crank angle refers to a crank angle when cranking is started by the second starter 7 (when the crankshaft 3 is stationary).
The rotational torque obtained from the kinetic energy stored in the engine 2 from the start of cranking increases and decreases depending on the initial crank angle. Therefore, by grasping the initial crank angle, the drive torque that can be output by the motor operation of the first starter 5 can be reduced. As a result, the power consumption of the first starter 5 can be reduced.

[Seventh Embodiment]
This embodiment is a second case where the engine 2 has passed the first TDC (first compression top dead center) without satisfying the passing conditional expression. In the present embodiment, the operation control of the first and

second starters

5 and 7 by the start control unit 17 is different from the second embodiment. Specifically, in this embodiment, as illustrated in FIG. 10, the first starter 5 is operated as an electric motor before the engine 2 gets over the first TDC. At this time, the first starter 5 outputs a driving torque having a value smaller than an upper limit value that can be set based on the output restriction map shown in FIG. 3A, for example. Thereafter, the first starter 5 keeps the drive torque at this small value (see the ON1 period shown in FIG. 10).

In the present embodiment, after the engine 2 gets over the first TDC, the operation of the second starter 7 is stopped before the clutch coupling timing. Further, in the present embodiment, the drive torque of the first starter 5 is increased stepwise to the target value (see the transition from ON1 to ON2 shown in FIG. 10).
Thereby, in this embodiment, before the engine 2 gets over the first TDC, the operation check of the first starter 5 can be performed.

It should be noted that the timing of raising the drive torque of the first starter 5 described above may be before or after the operation of the second starter 7 is stopped. The timing for raising the driving torque of the first starter 5 and the timing for stopping the operation of the second starter 7 may be changed according to the initial crank angle.

[Eighth Embodiment]
The present embodiment is a third case in which the engine 2 gets over the first TDC without the overtaking conditional expression being satisfied. In the present embodiment, the operation control of the first and

second starters

5 and 7 by the start control unit 17 is different from the seventh embodiment. Specifically, in the present embodiment, the first starter 5 is operated as an electric motor before the engine 2 gets over the first TDC. In this embodiment, unlike the seventh embodiment, as illustrated in FIG. 11, after starting the operation of the first starter 5, the drive torque is increased linearly (the drive torque is increased over time). Increase proportionally). In the present embodiment, after the engine 2 gets over the first TDC, the operation of the second starter 7 is stopped before the clutch engagement timing. Further, in the present embodiment, the drive torque of the first starter 5 is raised to the target value in a step shape.

[Ninth Embodiment]
The present embodiment is a fourth case where the engine 2 gets over the first TDC without the overtaking conditional expression being satisfied. This embodiment is different from the seventh and eighth embodiments in the operation control of the first and

second starters

5 and 7 by the start control unit 17. Specifically, in the present embodiment, the first starter 5 is operated as an electric motor before the engine 2 gets over the first TDC. Here, unlike the seventh and eighth embodiments, the present embodiment temporarily stops the first starter 5 as an electric motor, as illustrated in FIG. In the present embodiment, after the engine 2 gets over the first TDC, the operation of the second starter 7 is stopped before the clutch engagement timing. Further, in the present embodiment, the first starter 5 is operated as an electric motor.
Thereby, in this embodiment, before the engine 2 gets over the first TDC, the operation check of the engine start system 1 can be performed.

[Modification]
In the first embodiment, an example is shown in which known values that are grasped in advance as the compression torque and the friction torque of the engine 2 are input to the first control device 8 of the engine start system 1. For example, the peak value of the compression torque can be calculated by monitoring the battery voltage or the battery current. In the compression stroke, the compression torque is considerably larger than the friction torque (compression torque >> friction torque). Therefore, the ratio of the compression torque is large in the engine starting torque in the compression stroke. This compression torque peaks slightly before TDC (compression top dead center). Further, at the peak position of the compression torque, the slopes of the battery voltage and the battery current are substantially zero. Therefore, the peak value of the compression torque can be calculated by grasping in advance the correlation between the value of the battery voltage or battery current near the zero slope and the compression torque.
The engine starting system 1 detects the in-cylinder pressure of the engine 2 by using an existing in-cylinder pressure sensor. Then, the first control device 8 can calculate the compression torque by theoretical calculation based on the detection result.

In the first embodiment, the engine start system 1 has shown the example in which the rotation angle (crank angle) of the crankshaft 3 is detected by the crank angle sensor. For example, the first starter 5 is connected to the crankshaft 3 via the belt 4. Therefore, the engine start system 1 detects the rotation angle of the first starter 5 using a rotation angle sensor provided in the first starter 5. Then, the crank angle is estimated based on the rotation angle. In this case, the engine start system 1 can determine the timing of passing the first TDC (first compression top dead center) even if the crank angle sensor is not provided. Thereby, in the engine starting system 1, addition of a sensor, a branch of sensor wiring, etc. become unnecessary. As a result, the system can be simplified. Moreover, cost can be reduced.
In addition, although the 1st starter 5 of 1st Embodiment is connected with the crankshaft 3 via the belt 4, it is not this limitation. For example, a clutch may be built in the pulley of the first starter 5 around which the belt 4 is stretched.

In the first embodiment, an example in which the overpass conditional expression includes a drive torque that can be output from the first starter 5 is not limited thereto. An overtaking conditional expression that does not include the drive torque that can be output from the first starter 5 may be set. For example, the overriding determination unit 18 included in the first control device 8 includes a rotation torque obtained from kinetic energy stored in the engine 2 from the start of cranking, and an engine starting torque (compression torque of the engine 2 + friction torque). Based on the magnitude relationship, it may be determined whether the operation of the second starter 7 can be stopped before the engine 2 gets over the first TDC (first compression top dead center). In this case, when the passing condition formula is satisfied before the engine 2 gets over the first TDC (first compression top dead center), the timing when the operation of the second starter 7 is stopped, and the first starter 5 It is not necessary to match the timing of starting the motor operation. That is, the timing for starting the motor operation of the first starter 5 does not necessarily have to be before TDC (compression top dead center). It may be before the clutch engagement timing at the latest.

DESCRIPTION OF SYMBOLS 1 Engine start system 2 Engine 3 Crankshaft 4 Belt 5 1st starter 6 Ring gear 7 2nd starter 8 1st control apparatus 9 2nd control apparatus (start signal receiving part)
10 Pinion 11 Motor 12 Clutch (One-way clutch)
13 Electromagnetic switch (solenoid device)
17 Start control unit 18 Passover judgment unit 19 Relay (stop signal receiving unit)

Claims

A first starter (5) connected to the crankshaft (3) of the engine (2) to rotationally drive the crankshaft;
A second starter (7) for cranking the engine by rotationally driving a ring gear (6) coupled to the crankshaft;
A control device (8) for controlling the operation of the first starter and the second starter,
The first starter is
It is a motor generator with the functions of both a generator and an electric motor,
The second starter is
A motor (11) that rotates upon receipt of power supply;
A pinion (10) that moves axially and meshes with the ring gear;
A one-way clutch (12) capable of transmitting torque in only one direction from the motor side to the pinion side and blocking torque transmission from the pinion side to the motor side;
A solenoid device (13) having a function of moving the pinion in the axial direction and a function of starting / stopping power supply to the motor, and a pinion dive starter comprising:
The torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the first starter is the necessary torque,
The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque,
When defining the magnitude relationship over which the required torque for overriding is greater than the engine starting torque as an overtaking conditional expression,
The control device includes:
In response to the engine start request, after starting the second starter and starting cranking, the operation of the second starter is stopped at a predetermined timing, and the motor operation of the first starter is performed. A start control unit (17) to start;
An overpass determination unit (18) for determining whether or not the overpass conditional expression is satisfied after cranking is started by the second starter;
The start controller is
Before the engine gets over the first compression top dead center, when the ride over condition is satisfied, the operation of the second starter is stopped regardless of whether the engine got over the first compression top dead center or not. And an engine start system (1) for starting the motor operation of the first starter.
The start control unit
The timing to stop the operation of the second starter and the motor operation of the first starter are started when the engine has passed the first compression top dead center without satisfying the overtaking conditional expression. The engine start system according to claim 1, wherein the timing is set before a timing at which the one-way clutch is estimated to be re-engaged.
The start control unit
The timing for starting the motor operation of the first starter is set to be the same as the timing for stopping the operation of the second starter or before or after the timing of stopping the operation of the second starter. The engine starting system as described in.
The start control unit
The engine start system according to any one of claims 1 to 3, wherein a timing at which the motor operation of the first starter is started is set after power supply to the motor of the second starter is stopped. .
The start control unit
Grasp the initial crank angle before the cranking starts,
The timing for stopping the operation of the second starter after the cranking is started and the timing for starting the motor operation of the first starter are changed according to the initial crank angle. The engine start system according to any one of claims 1 to 4.
The control device includes:
The engine start system according to any one of claims 1 to 5, wherein the first starter is temporarily operated as an electric motor to stop before the engine gets over the first compression top dead center.
A first starter (5) connected to the crankshaft (3) of the engine (2) and capable of rotationally driving the crankshaft;
A second starter (7) for cranking the engine by rotationally driving a ring gear (6) coupled to the crankshaft;
A control device (8) for controlling the operation of the first starter and the second starter,
The first starter is
It is a motor generator with the functions of both a generator and an electric motor,
The second starter is
A motor (11) that rotates upon receipt of power supply;
A pinion (10) that moves axially and meshes with the ring gear;
A one-way clutch (12) capable of transmitting torque in only one direction from the motor side to the pinion side and blocking torque transmission from the pinion side to the motor side;
A solenoid device (13) having a function of moving the pinion in the axial direction and a function of starting / stopping power supply to the motor, and a pinion dive starter comprising:
The torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the first starter is the necessary torque,
The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque,
When defining the magnitude relationship over which the required torque for overriding is greater than the engine starting torque as an overtaking conditional expression,
The control device includes:
In response to the engine start request, after starting the second starter and starting cranking, the motor operation of the first starter is started, and further, the operation of the second starter is performed at a predetermined timing. A start control unit (17) to stop;
An overpass determination unit (18) for determining whether or not the overpass conditional expression is satisfied after cranking is started by the second starter;
The start controller is
Before the engine gets over the first compression top dead center, when the ride over condition is satisfied, the operation of the second starter is stopped regardless of whether the engine got over the first compression top dead center or not. And an engine start system (1) for increasing the output by the motor operation of the first starter.
The start control unit
The timing at which the operation of the second starter is stopped and the output by the motor operation of the first starter when the engine has passed the first compression top dead center without satisfying the overtaking conditional expression and the motor operation of the first starter. The engine start system according to claim 7, wherein a timing for raising is set before a timing at which the one-way clutch is estimated to be re-engaged.
The start control unit
The timing for raising the output by the motor operation of the first starter is set to be the same as the timing for stopping the operation of the second starter, or before or after the timing for stopping the operation of the second starter. 9. The engine starting system according to 8.
The start control unit
The engine start according to any one of claims 7 to 9, wherein a timing at which an output generated by motor operation of the first starter is increased is set after power supply to the motor of the second starter is stopped. system.
The start control unit
Grasp the initial crank angle before the cranking starts,
The timing for stopping the operation of the second starter after the cranking is started and the timing for raising the output by the motor operation of the first starter are changed according to the initial crank angle. Item 11. The engine start system according to any one of Items 7 to 10.
The solenoid device is
A first solenoid having a function of moving the pinion in the axial direction;
A second solenoid having a function of starting / stopping an energization current to the motor,
The start control unit
2. The pinion is detached from the ring gear by the first solenoid before the power supply to the motor is stopped by the second solenoid when the operation of the second starter is stopped. The engine start system according to any one of 11.
When at least one condition necessary for determining whether or not the above-mentioned conditional expression is satisfied is used as a determination condition,
The transit determination unit
The engine start system according to any one of claims 1 to 12, wherein an engine speed is set as the overtaking determination condition.
A crank angle sensor for detecting a rotation angle of the crankshaft;
The start control unit
The engine start system according to claim 13, wherein the engine speed is calculated based on a rotation angle of the crankshaft detected by the crank angle sensor.
A rotation angle sensor for detecting a rotation angle of the first starter;
The start control unit
The engine start system according to claim 13, wherein a crank angle is estimated based on a rotation angle of the first starter detected by the rotation angle sensor, and the engine speed is calculated based on the estimated crank angle.
The first starter is
The engine start system according to any one of the preceding claims, wherein the engine start system is connected to the crankshaft via a belt (4).
A motor generator connected to the crankshaft (3) of the engine (2) and having both functions of an electric motor for rotationally driving the crankshaft and a generator;
The operation is controlled by a control device (8) together with a second starter (7) which is a pinion dive starter that cranks the engine by rotationally driving a ring gear (6) connected to the crankshaft. 1 starter (5),
The torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the electric motor as a necessary torque,
The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque,
When defining the magnitude relationship over which the required torque for overriding is greater than the engine starting torque as an overtaking conditional expression,
The control device includes:
In response to the engine start request, after starting the second starter and starting cranking, the operation of the second starter is stopped at a predetermined timing, and the motor operation of the first starter is performed. A start control unit (17) to start;
An overpass determination unit (18) for determining whether or not the overpass conditional expression is satisfied after cranking is started by the second starter;
The start controller is
Before the engine gets over the first compression top dead center, when the ride over condition is satisfied, the operation of the second starter is stopped regardless of whether the engine got over the first compression top dead center or not. And transmitting a start signal for starting the motor operation of the first starter,
The first starter is
A first starter having a start signal receiver (9) for receiving the start signal.
A control device as well as a first starter (5) having a motor generator coupled to the crankshaft (3) of the engine (2) and having both functions of an electric motor capable of rotating the crankshaft and a generator The operation is controlled by (8),
A second starter (7) that is a pinion dive starter that cranks the engine by rotationally driving a ring gear (6) coupled to the crankshaft;
The torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the first starter is the necessary torque,
The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque,
When defining the magnitude relationship over which the required torque for overriding is greater than the engine starting torque as an overtaking conditional expression,
The control device includes:
In response to the engine start request, after starting the second starter and starting cranking, the operation of the second starter is stopped at a predetermined timing, and the motor operation of the first starter is performed. A start control unit (17) to start;
An overpass determination unit (18) for determining whether or not the overpass conditional expression is satisfied after cranking is started by the second starter;
The start controller is
Before the engine gets over the first compression top dead center, when the overriding conditional expression is satisfied, the motor operation of the first starter is performed regardless of whether or not the engine got over the first compression top dead center. Sending a stop signal to start and stop the operation of the second starter;
The second starter is
A second starter having a stop signal receiver (19) for receiving the stop signal.
A motor generator connected to the crankshaft (3) of the engine (2) and having both functions of an electric motor for rotationally driving the crankshaft and a generator;
The operation is controlled by a control device (8) together with a second starter (7) which is a pinion dive starter that cranks the engine by rotationally driving a ring gear (6) connected to the crankshaft. 1 starter (5),
The torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the electric motor as a necessary torque,
The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque,
When defining the magnitude relationship over which the required torque for overriding is greater than the engine starting torque as an overtaking conditional expression,
The control device includes:
In response to the engine start request, after starting the second starter and starting cranking, the motor operation of the first starter is started, and further, the operation of the second starter is performed at a predetermined timing. A start control unit (17) to stop;
An overpass determination unit (18) for determining whether or not the overpass conditional expression is satisfied after cranking is started by the second starter;
The start control unit
Before the engine gets over the first compression top dead center, when the ride over condition is satisfied, the operation of the second starter is stopped regardless of whether the engine got over the first compression top dead center or not. And transmitting a start signal for raising the output by the motor operation of the first starter,
The first starter is
A first starter having a start signal receiver (9) for receiving the start signal.
A control device as well as a first starter (5) having a motor generator coupled to the crankshaft (3) of the engine (2) and having both functions of an electric motor capable of rotating the crankshaft and a generator The operation is controlled by (8),
A second starter (7) that is a pinion dive starter that cranks the engine by rotationally driving a ring gear (6) coupled to the crankshaft;
The torque obtained by adding the rotational torque obtained from the kinetic energy stored in the engine from the start of cranking and the drive torque that can be output by the motor operation of the first starter is the necessary torque,
The engine starting torque is a torque obtained by adding the compression torque of the engine and the friction torque,
When defining the magnitude relationship over which the required torque for overriding is greater than the engine starting torque as an overtaking conditional expression,
The control device includes:
In response to the engine start request, after starting the second starter and starting cranking, the motor operation of the first starter is started, and further, the operation of the second starter is performed at a predetermined timing. A start control unit (17) to stop;
An overpass determination unit (18) for determining whether or not the overpass conditional expression is satisfied after cranking is started by the second starter;
The start control unit
When the overriding conditional expression is satisfied before the engine gets over the first compression top dead center, regardless of whether the engine gets over the first compression top dead center, the motor operation of the first starter Raise the output and send a stop signal to stop the operation of the second starter,
The second starter is
A second starter having a stop signal receiver (19) for receiving the stop signal.