JP2009162196A - Start device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device preventing a pinion from disengaging from a ring gear even if a crankshaft is rotated by combustion start. <P>SOLUTION: This device is provided with a combustion start means S5, a starter including a motor and an engaging/disengaging mechanism, a pre-engagement means S3 making the pinion engage with the ring gear before combustion start by a combustion start means S5, a motor torque control means S5 carrying out torque control with using the motor to make rise rate of ring gear rotation speed raised by combustion start by the combustion start means S5 same as rise rate of pinion rotation speed, a judgment means S6 judging if combustion start by the combustion start means S5 is failed or successful, and a starter start means S7 stopping torque control with using the motor by the motor torque control means S5 and starting the engine by the motor when combustion start is failed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine (engine) starter, and more particularly to a technique for starting an engine by combustion in a specific cylinder.

As a so-called starterless starting technology, a fuel injection valve for directly injecting fuel into the combustion chamber and an ignition plug for igniting the fuel injected by the fuel injection valve are provided for each cylinder. The cylinder stopped in the expansion stroke at the time of stopping is determined, combustion is generated in the determined cylinder, and the engine is started with the combustion as a trigger (starting by combustion in such a specific cylinder is hereinafter referred to as “combustion”). There is one that is referred to as “starting” (see Patent Document 1).
JP 2006-214377 A

  By the way, since combustion start does not require a starter (starter motor) to start the engine, it is considered as a technology for restarting an idle stop that requires significantly higher durability for the starter motor because the engine start frequency is much higher. However, the combustion start may fail and the engine may not start. In this case, if the starter is configured to be backed up, a time lag of several tens of msec is generated by the operation of meshing the pinion with the ring gear, so when starting using the starter after detecting that the combustion start has failed, This time lag makes the driver feel uncomfortable. Here, in order to eliminate the occurrence of a time lag, there is a technique in which the pinion of the starter is meshed with the ring gear in advance (= pre-engagement), but when the combustion is started and the crankshaft is rotated while the pinion is meshed with the ring gear, The pinion leaves the ring gear alone. If the combustion start is successful, there is no problem, but if the combustion start fails, the pinion that has left the ring gear needs to be engaged with the ring gear again, and the above time lag occurs again.

  Therefore, the present invention has an object to provide a device in which a pinion of a starter is previously meshed with a ring gear before starting combustion, but the pinion is not detached from the ring gear even if the crankshaft is rotated by starting combustion. And

  The present invention provides an engine having a fuel injection valve (11) for directly injecting fuel into a combustion chamber and a spark plug (12) for igniting the fuel injected by the fuel injection valve for each cylinder. Combustion starting means (step 5 in FIG. 3) for starting the engine by rotating the crankshaft by fuel injection and fuel ignition by the fuel injection valve and the spark plug in the cylinder, and a motor (41) for generating torque A starter (31) including an engagement / disengagement mechanism (51, 71) for engaging the pinion (64) with a ring gear (3) that moves integrally with the crankshaft, or for disengaging the pinion (64) from the ring gear (3); Pre-engagement in which a pinion is engaged with a ring gear using the engagement / disengagement mechanism prior to combustion start by the combustion start means The step (step 3 in FIG. 3) is performed using the motor (41) so that the rate of increase of the ring gear rotational speed that is increased by the combustion start by the combustion start means is the same as the rate of increase of the pinion rotational speed. Motor torque control means for performing torque control (step 5 in FIG. 3), determination means for determining whether the combustion start by the combustion start means has failed or successful (step 6 in FIG. 3), and combustion based on this determination result Starter starting means (step 7 in FIG. 3) for stopping torque control using the motor (41) by the motor torque control means and starting the engine by the motor (41) when starting fails. .

  According to the present invention, the combustion starting means for starting the engine by rotating the engine by fuel injection and fuel ignition by the fuel injection valve and the spark plug in a specific cylinder, a motor for generating torque, and a pinion A starter including an engagement / disengagement mechanism that meshes with a ring gear that moves integrally with the crankshaft or disengages the pinion from the ring gear, and rings the pinion using the engagement / disengagement mechanism prior to the combustion start by the combustion starter Engage with the gear, and perform torque control of the motor so that the rate of increase of the ring gear rotational speed that is rotationally increased by the combustion start by the combustion start means is the same as the rate of increase of the pinion rotational speed, and the combustion start It is judged whether the combustion start by means has failed or succeeded. When starting fails, the torque control using the motor by the motor torque control means is stopped and the engine is started by the motor. Therefore, even if the combustion starting fails, the pinion meshes with the ring gear. It is possible to start the engine with a starter from a closed state, so that there is no time lag until the pinion meshes with the ring gear, so even if the combustion start fails, the engine can be started quickly and the driver Does not cause any discomfort.

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

  FIG. 1 is a schematic configuration diagram of an in-cylinder direct injection engine according to an embodiment of the present invention.

  As shown in FIG. 1, a fuel injection valve 11 that directly injects fuel into the combustion chamber 2 and a spark plug 12 that ignites an air-fuel mixture in the combustion chamber 2 are provided in the combustion chamber 2. It is arranged in a state of facing.

  The engine control unit 21 controls the fuel injection amount from the fuel injection valve 11 and the ignition timing by the spark plug 12 so that a desired engine torque can be obtained during engine operation based on the input detection signal. To do.

  Further, the engine control unit 21 releases the idle stop after the normal engine stop that stops the engine 1 by turning off the ignition switch 26, or when a predetermined idle stop condition defined with respect to the vehicle speed or the like is satisfied. Until the condition is satisfied, idle stop is performed to temporarily stop the engine 1. In this embodiment, a) the accelerator pedal position is not more than a predetermined value and the accelerator pedal is completely returned, and b) a substantial stop state where the vehicle speed is not more than a predetermined value continues for a predetermined time. And c) The idling stop is executed on condition that the cooling water temperature is equal to or higher than a predetermined temperature. The vehicle speed can be calculated based on the engine rotation speed, the transmission gear ratio, and the like. Further, the idle stop is canceled on the condition that it is determined that the accelerator pedal is depressed. Therefore, a signal from the crank angle sensor 22, a signal from the cam angle sensor 23, an accelerator opening signal from the accelerator sensor 24, and a cooling water temperature signal from the water temperature sensor 25 are input to the engine control unit 21.

  In the present embodiment, the crankshaft stop position is detected by the crank angle sensor 22 at the time of the idle stop, and at the restart after the idle stop, based on the detected stop position and the signal from the cam angle sensor 23, The cylinder (specific cylinder) stopped in the expansion stroke at the time of idling stop is determined, and the determined cylinder is used as the cylinder for starting the combustion start to perform the combustion start.

  In this case, since combustion start does not require a starter to start the engine, it is a technology at the time of restart from an idle stop that requires a significantly high durability for the starter motor because the number of engine starts is remarkably high. Actually, the combustion start may fail and the engine may not be started. In preparation for such a failure of combustion start, if it is configured to back up with a normal starter, a time lag of several tens of msec is generated by the operation of biting the pinion into the ring gear, so after detecting that the combustion start has failed, If the engine is switched to starter start and the engine is started using the starter motor, there is a problem that the driver feels uncomfortable.

  In this case, there is a technology to pre-engage the starter pinion with the ring gear (= pre-engagement), but the combustion is started with the pinion meshing with the ring gear, and it is burned into the crankshaft, and thus the flywheel outer periphery. When the ring gear is rotating, the pinion will come off the ring gear without permission. This is because if the starter is transmitting torque to the ring gear via the pinion, the pinion will not disengage from the ring gear, but when the torque is transmitted from the ring gear back to the pinion, the overrunning clutch This is because the pinion rotates idly and the helical spline of the amateur shaft moves toward the separation direction and returns to the initial state. For this reason, when the combustion start fails, it is necessary to re-engage the pinion that has been disengaged with the ring gear, and the pinion 64 and the ring gear 3 are pre-engaged (pre-engaged state) prior to the start of combustion. However, the same problem as above occurs.

Therefore, according to the present invention, the starter pinion is meshed with the ring gear in advance (= pre-engage) prior to the start of combustion, and torque control using the starter motor is performed in accordance with the increase in rotation of the crankshaft caused by the start of combustion. The rate of increase in rotational speed is set to be the same as the rate of increase in rotational speed of the ring gear, so that a pre-engagement state in which the pinion does not disengage from the ring gear is maintained. To do.
In order to perform such control, it is necessary to configure the starter magnet switch control (ON, OFF) and the motor control (ON, OFF, and torque control) to be performed independently. This configuration will be described with reference to FIG. 1 and FIG. 2. As shown in FIG. 1, a starter 31 and a starter control device 32 are additionally provided, and a microcomputer, a storage device, an input / output device, etc. The starter control device 32 configured and the engine controller 21 are connected by a communication device 33.

  FIG. 2 is a detailed view of the starter 31. Although an example of a magnetic shift starter is shown here, the starter is not limited to this type.

  The starter 31 is largely engaged with the ring gear 3 by causing the pinion to jump out of the ring gear 3 via the lever 71 by turning the current from the motor 41 generating torque and the battery 34 on and off. The magnet switch 51 (meshing / disengaging mechanism) that retracts the ring gear 3 from the ring gear and detaches the pinion from the ring gear, and the pinion mechanism 61 that meshes with the ring gear 3 and transmits the torque generated by the motor 41 in conjunction with the magnet switch 51. ing.

  The plunger 52 of the magnet switch 51 can slide in the left-right direction in FIG. 2, and the return spring 53 biases the plunger 52 and one end 72 of the shift lever 71 in the right direction so that the main contact 54 and the contactor 55 are separated. It is in the state.

  The plunger 52 is wound with approximately the same number of suction coils 56 and holding coils 57, and one ends of these coils 56, 57 are connected to a normally-open first relay 81, which will be described later. The other end of the suction coil 56 is connected to an M terminal or ground via a change-over switch 84 described later, and the other end of the holding coil 57 is grounded internally.

  The main parts of the motor 41 are an amateur housed in a cylinder, which includes an amateur shaft 44 with a helical spline cut, a yoke which is a cast iron cylinder, and an amateur coil (field coil) fixed to the inner periphery of the yoke. Coil), a core, a commutator 45 that receives a current supply, a brush 46 that is pressed against the commutator 45, and the like. The armature shaft 44 is rotatably supported by bearings at both ends, and a pinion mechanism 61 is provided at one end. Yes.

  In the magnetic shift type, the pinion 64 continues to engage with the ring gear 3 unless the magnet switch 51 is turned OFF even when the engine is started. If the meshing is not released, the motor 41 is rotated at a rotation speed 10 to 15 times (tooth ratio) of the engine rotation speed. In order to prevent this, an overrunning clutch that does not transmit the rotation from the crankshaft 4 (ring gear 3) to the motor 41 is provided in the pinion mechanism 61. The overrunning clutch includes a spline tube 62 fixed to the amateur shaft 44, a clutch outer 63, and a roller. Torque generated in the amateur shaft 44 is transmitted to the clutch outer 63 through the spline tube 62. The inner side of the clutch outer 63 is tapered, and a roller pressed by a spring is included therein. This roller acts as a key within the gap of the taper to transmit the power from the armature shaft 44 to the pinion 64, and by rotating idly, does not transmit the rotation of the pinion 64 to the clutch outer 63.

  A cylindrical member 65 with sleeves 65a on both sides is provided at the left end of the pinion mechanism 61. The other end 73 of the shift lever 71 is fitted so as to be sandwiched between the sleeves, and the shift lever 7 and the pinion mechanism 61 are inserted. And are engaged.

  Since the starter controller 32 independently controls the magnet switch 51 (ON, OFF) and the motor 41 (ON, OFF, and torque control), the battery 34 and the magnet switch 51 are normally opened. A first relay 81 and a normally open second relay 82 are interposed between the main contact 54 and the brush 46 of the motor. The relays 81 and 82 close the contacts 81b and 82b when the coils 81a and 82a are energized, and reopen the contacts 81b and 82b when the coils 81a and 82a are de-energized. It is not limited to a relay, and any switching means may be used.

  A voltage control device 83 is provided between the second relay 82 and the brush 46. When the control signal from the starter control device 32 is not output, the voltage control device 83 outputs the voltage from the battery 34 to the motor 41 as it is, and when the control signal from the starter control device 32 is output, The voltage applied to the motor 41 is variably adjusted in accordance with a control signal from the starter control device 32 with the battery voltage as a maximum value.

  A changeover switch 84 is provided between the suction coil 56 and the M terminal. The changeover switch 84 connects the suction coil 56 to the ground when the control signal from the starter control device 32 is not output, and switches the suction coil 56 when the control signal from the starter control device 32 is output. Connect to M terminal.

  The two relays 81 and 82, the voltage control device 83, and the changeover switch 84 are controlled by the starter control device 32.

  Next, the control executed by the starter control device 32 will be described based on the flowchart of FIG.

  FIG. 3 is for performing idle stop and subsequent restart control. This flow shows the flow of control and does not repeat every certain time. This flow is activated when the ignition switch 26 is turned on. It is assumed that signals necessary for control of idle stop and subsequent restart are given from the engine control unit 21 via the communication device 33.

  In step 1, it is determined whether or not a predetermined idle stop condition is satisfied. When the idle stop condition is satisfied, the process proceeds to step 2, and when the idle stop condition is not satisfied, the process returns to step 1. In the present embodiment, as described above, a) the accelerator opening detected by the accelerator sensor 24 is equal to or smaller than a predetermined value and the accelerator pedal is completely returned, and b) the vehicle speed is substantially equal to or smaller than the predetermined value. The idling stop is executed on condition that the stationary stop state continues for a predetermined time and c) the cooling water temperature detected by the water temperature sensor 25 is equal to or higher than the predetermined temperature. The vehicle speed can be calculated based on the engine speed detected by the crank angle sensor 22, the transmission gear ratio, and the like.

  In step 2, all the operations of the fuel injection valve 11 and the spark plug 12 of each cylinder are stopped, and the engine 1 is stopped.

  In Step 3, the relay coil 81a is energized to close the relay contact 81b (the first relay 81 is turned on), the magnet switch 51 is operated, and the pinion 64 is engaged with the ring gear 3 (= pre-engaged state). That is, when the relay contact 81b is closed in FIG. 2, a current flows through the battery 34 to the attraction coil 56 and the holding coil 57 of the magnet switch 51, and an attraction force is generated. Due to this suction force, the plunger 52 moves to the left in FIG. 2, whereby the one end 72 of the shift lever 71 rotates about the fulcrum in the counterclockwise direction. With the rotation of the shift lever 71, the other end 73 of the shift lever 71 pushes the pinion mechanism 61 and thus the pinion 64 to the right in FIG. 2 through the cylindrical member 65 and meshes with the ring gear 3. On the other hand, when the pinion 64 and the tooth surface of the ring gear 3 collide, the state is maintained as it is.

  Further, when the plunger 52 moves further leftward in FIG. 2 by the suction force, the contactor 55 is pressed against the main contact 54.

  In Step 3, the second relay 82 is turned off (the relay coil 82a is not energized), the changeover switch 84 is set to the ground side, and the voltage control device 83 is not operated. For this reason, even if the contactor 55 is pressed against the main contact 54, the electric power from the battery 34 is not supplied to the motor 41.

  In step 4, it is determined whether or not a predetermined idle stop cancellation condition (restart condition) is satisfied. When this idle stop cancellation condition is satisfied, the routine proceeds to step 5, and when the idle stop cancellation condition is not satisfied, the routine returns to step 4. In the present embodiment, the idling stop is canceled on the condition that the accelerator sensor 24 detects an accelerator opening greater than or equal to a predetermined value and determines that the accelerator pedal is depressed.

  In step 5, while starting the engine 1 by combustion start, an increase rate Δup of the ring gear rotation speed (= engine rotation speed) is calculated, the second relay 82 is turned ON (the relay coil 82 a is energized and the relay contact 82 b is closed). ) And the torque control of the motor 41 is performed using the voltage control device 83 so that the pinion rotation speed increases at the same increase rate as the calculated increase rate Δup of the ring gear rotation speed. At this time, the changeover switch 84 is set to the M terminal side.

  The individual operations in Step 5 will be described. First, the combustion start is performed as follows. That is, based on the stop position of the crankshaft 4, a specific cylinder that is a cylinder stopped in the expansion stroke at the previous stop is determined, and fuel injection and ignition are performed on the determined specific cylinder. Combustion is produced and the engine 1 is started. Although the crankshaft 4 increases in rotation speed by this combustion start, the ring gear 3 that moves integrally with the crankshaft 4 also rotates, and tries to transmit the torque generated by the crankshaft to the pinion 64. At this time, if the pinion 64 is transmitted with torque from the ring gear 3, the pinion 64 is detached from the ring gear 3. The operation for preventing the separation from the ring gear 3 is the next operation.

  By searching a table having the contents shown in FIG. 4 from the coolant temperature Tw detected by the water temperature sensor 25, an increase rate Δup of the ring gear rotation speed (= engine rotation speed) is calculated. Here, the increase rate of the ring gear rotation speed is an increase amount of the ring gear rotation speed per predetermined time when the combustion start is successful. As shown in FIG. 4, the increase rate Δup of the ring gear rotation speed is a value that decreases as the cooling water temperature Tw decreases. This is because the engine friction increases as the cooling water temperature Tw decreases, and therefore, the increase rate Δup of the engine rotation speed (ring gear rotation speed) decreases as the engine friction increases even if the same fuel amount is supplied at the start of combustion. It is. The characteristics shown in FIG. 4 are actually determined in advance by adaptation.

  However, the piston stop position in the specific cylinder is slightly shifted every time an idle stop is actually performed. If the piston position in the expansion stroke in a specific cylinder is different, the rate of increase Δup of the ring gear rotation speed (= engine rotation speed) may be different even if the cooling water temperature is the same. Therefore, the piston position in the expansion stroke in a specific cylinder is detected (this can be easily detected by the crank angle sensor 22 and the cam angle sensor 23), and the increase rate Δup of the ring gear rotation speed is corrected according to the detected piston position. It is preferable to do. For example, if the characteristic of FIG. 4 is obtained at the reference piston position (the increase rate obtained by FIG. 4 is referred to as “reference increase rate”), the piston position is deviated from the reference piston position. Then, the ratio of the increase rate of the ring gear rotation speed is measured, and the difference between the measured increase rate and the reference increase rate becomes the correction value of the increase rate. Accordingly, the correction value for the rising rate is obtained by changing the piston position under the same cooling water temperature condition. Similarly, after changing the cooling water temperature, the piston position is changed to obtain a correction value for the rising rate. It is only necessary to organize the data obtained in this way and create a correction value map using the piston position and the coolant temperature as parameters.

  Next, the second relay 82 is turned on to supply the electric power from the battery 34 to the motor 41 so that the motor 41 is driven, and the same increase as the ring gear rotation speed that increases at the calculated increase rate Δup of the ring gear rotation speed. Torque control generated by the motor 41 is performed using the voltage control device 83 so that the pinion rotation speed (= motor rotation speed) increases at a rate. In this case, when waiting in a state where the pinion 64 and the tooth surface of the ring gear 3 collide at the stage of step 3, the pinion 64 and the ring gear 3 are engaged with each other as follows. That is, when the tooth surface collides, it is not bitten as it is. In this case, when a current flows through the field coil of the motor 41 and the armature rotates while the tooth surface remains collided, the pressure on the tooth contact surface gradually increases due to the rotation of the armature and the action of the helical spline. Then, the pinion 64 turns and the position of the colliding tooth is shifted and meshed.

  If the combustion start is successful, the pinion rotational speed and the ring gear rotational speed are increased at the same rate by the torque control using the motor 41 in step 5. In the state where the increase ratio of the pinion rotation speed and the ring gear rotation speed is the same, that is, in the state where the pinion 64 rotates at the same speed as the ring gear 3, the torque generated by the motor 41 is not transmitted to the ring gear 3 via the pinion 64. Conversely, the torque generated by the crankshaft 4 from the ring gear 3 is not transmitted to the pinion 64. Therefore, even if the crankshaft 4, and hence the ring gear 3, rotates to transmit torque to the pinion 64 by combustion start, the pinion 64 rotates by itself, so that torque can be transmitted from the ring gear 3 toward the pinion 64. Thus, the pinion 64 is not detached from the ring gear 3 (maintains a pre-engaged state).

  On the other hand, if the combustion start has failed, the torque control using the motor 41 in step 5 causes the ring gear 3 and therefore the crankshaft 4 to be rotated by the motor 41 through the engagement of the pinion 64 and the ring gear 3. Is done. That is, since the torque generated by the motor 41 is transmitted from the pinion 64 to the ring gear 3, the pinion 64 does not leave the ring gear 3 (maintains a pre-engaged state).

  In step 6, the engine rotation speed increase rate (change amount of the engine rotation speed per predetermined time) ΔNe is calculated, and the engine rotation speed increase rate ΔNe is compared with a predetermined value ΔN1, thereby failing in combustion start. It is determined whether or not. Here, the predetermined value ΔN1 is determined as follows. That is, FIG. 5 shows, as a model, changes in the engine rotational speed Ne when the combustion start is successful and when the combustion start is unsuccessful at the restart after the idle stop. When the combustion start is successful, the engine rotation speed Ne gradually increases while taking a mountain-like change as shown by the solid line. For example, in the case of a four-cylinder engine in which the ignition order is 1-3-3-4-2, if the start cylinder (specific cylinder) for starting combustion is the first cylinder, the first peak is the first cylinder It is determined that the engine has started after reaching the complete explosion speed N2. On the other hand, if combustion is not smoothly performed in the first cylinder, which is the start cylinder of combustion start, and no torque is generated in the start cylinder of combustion start, the engine rotation speed Ne decreases toward zero as indicated by a broken line ( When combustion start fails 1). Alternatively, the engine rotation speed may remain zero (when combustion start fails 2). Therefore, if the predetermined value ΔN1 is provided at the position shown in the figure, the increase rate ΔNe of the engine rotation speed becomes larger than the value ΔN1 when the combustion start is successful, and conversely the engine rotation speed when the combustion start fails. Since the increase rate ΔNe of the engine is smaller than the value ΔN1, if the combustion start is successful when the increase rate ΔNe of the engine rotation speed is equal to or greater than the predetermined value ΔN1, the increase rate ΔNe of the engine rotation speed is reversed to the predetermined value ΔN1. If it is less than that, it can be determined that the combustion start has failed.

  Returning to FIG. 3, when the engine rotation speed increase rate ΔNe is less than the predetermined value ΔN1 in step 6, the combustion start has failed. At this time, the routine proceeds to step 7 where the starter 31 starts the engine 1. In other words, if the voltage control device 83 is deactivated while the two relays 81 and 82 are in the ON state, the voltage control device 83 is the same as the absence of the voltage control device 83 and the voltage of the battery 34 acts on the motor 41 as it is. At this time, a large current from the battery 51 flows into the field coil of the motor 41, and the motor 41 rotates the ring gear 3 and hence the crankshaft 3 through the pinion 64 with the maximum torque generated by the motor 41 (the cranking is performed by the starter 31). )

  In this case, when the starter is started in step 7, the pinion 64 stands by in a state of being engaged with the ring gear 3, so that the time for turning on the magnet switch 51 and engaging the pinion 64 with the ring gear 3 can be omitted. For this reason, even if the combustion start fails, the time until the engine start can be shortened.

  In the subsequent step 8, the engine rotational speed Ne and the complete explosion rotational speed N2 are compared. If the engine rotational speed Ne is less than the complete explosion rotational speed N2, the system waits as it is, and if the engine rotational speed Ne becomes equal to or higher than the complete explosion rotational speed N2, it is determined that the engine 1 has started, and the process proceeds to step 9 and the first relay 81 Is set to OFF. The second relay 82 remains in the ON state, and the voltage control device 83 continues to be inactive.

  At the moment when the first relay 81 is turned off, the main contact 54 is still closed in FIG. 2, so that a current flows through the suction coil 56 through the M terminal and the changeover switch 84 in the opposite direction from the start. At this time, the direction of the magnetic force lines of the attracting coil 56 and the holding coil 57 are reversed, but the number of turns of the coils 56 and 57 is substantially the same, so the magnetic force lines are canceled and the attractive force acting on the plunger 52 is Disappear. Therefore, due to the restoring force of the return spring 53, one end 72 of the shift lever 71 moves to the right in FIG. 2, and the other end 73 moves to the left in FIG. Let Due to the leftward movement of the pinion mechanism 61, the pinion 64 is detached from the ring gear 3 and returned to the original position, and the contactor 55 is opened to cut off the power supply to the motor 41 and the motor 41 (starter 31) is stopped. .

  On the other hand, when the increase rate ΔNe of the engine speed becomes equal to or greater than the predetermined value ΔN1 in step 6 of FIG. 3, the combustion start is successful. At this time, in order to cancel the engine start by the starter 31 waiting in a state where the pinion 64 and the ring gear 3 are engaged with each other, the process proceeds to step 10 and, similarly to step 9, the first relay 81 is turned off and the voltage control device 83 is deactivated. The second relay 82 is kept ON.

  The operation at this time is the same as in Step 9. That is, since the main contact 54 is still closed in FIG. 2 at the moment when the first relay 81 is turned off, a current flows through the suction coil 56 through the M terminal and the changeover switch 84 in the direction opposite to that at the start. At this time, the direction of the magnetic force lines of the attracting coil 56 and the holding coil 57 are reversed, but the number of turns of the coils 56 and 57 is substantially the same, so the magnetic force lines are canceled and the attractive force acting on the plunger 52 is Disappear. Therefore, due to the restoring force of the return spring 53, the shift lever 71 is rotated clockwise in FIG. 2 around the fulcrum, and the pinion 64 is detached from the ring gear 3 by the rotation of the shift lever 71 and is returned to the original position. And the contactor 55 is opened, the power supply to the motor 41 is cut off, and the motor 41 (starter 31) stops.

  Here, the effect of this embodiment is demonstrated.

  According to the present embodiment (the invention described in claim 1), in an engine provided with a fuel injection valve 11 and a spark plug 12 for each cylinder, fuel is injected by the fuel injection valve 11 and the spark plug 12 in a specific cylinder. Combustion starting means (see step 5 in FIG. 3) for rotating the engine by ignition of the fuel and starting the engine, a motor 41 for generating torque, and a pinion 64 are engaged with the ring gear 3 that moves integrally with the crankshaft 4. Or a starter 31 including an engagement / disengagement mechanism (magnet switch 51 and shift lever 71) for separating the pinion 64 from the ring gear 3, and the pinion 64 using the engagement / disengagement mechanism prior to the start of combustion by the combustion starting means. Pre-meshing means (see step 3 in FIG. 3) for meshing with the ring gear 3, and the combustion start Motor torque control means for performing torque control using the motor 41 so that the rate of increase of the ring gear rotation speed that is increased by the combustion start by the means is the same as the rate of increase of the pinion rotation speed (see step 5 in FIG. 3). ), Determination means for determining whether the combustion start by the combustion start means has failed or not (see step 6 in FIG. 3), and if the combustion start has failed from the determination result, the motor torque control means Since starter starting means (see step 7 in FIG. 3) for stopping the torque control using the motor 41 and starting the engine 1 by the motor 41 is provided, even if the combustion start fails, the pinion 64 is engaged with the ring gear 3. The engine can be started by the starter 31 from the combined state. As a result, there is no time lag until the pinion 64 meshes with the ring gear 3, so even if the combustion start fails, the engine 1 can be started quickly, and the driver does not feel uncomfortable. .

  If the pinion 64 is engaged in the ring gear 3 forever after the start of combustion is successful, noise due to the meshing of teeth is generated as a starting sound. According to this embodiment (the invention according to claim 2), For example, when the combustion start is successful, the torque control using the motor 41 by the motor torque control unit is stopped, and the pinion 64 and the ring gear 3 are engaged using the engagement / disengagement mechanism by the pre-engagement unit. Since the pinion 64 is disengaged from the ring gear 3 (see steps 6 and 10 in FIG. 3), the drive time of the motor 41 for starting the engine can be minimized, and the starting noise can be reduced.

  According to the present embodiment (the invention described in claim 3), the voltage control device 83 that generates a voltage to be applied to the motor 41 by adjusting the battery voltage is provided, and the motor torque control unit is configured to fail in combustion start. In addition, the adjustment of the battery voltage by the voltage control device 83 is stopped and the battery voltage is directly applied to the motor 41 (see steps 6 and 7 in FIG. 3), so that the pinion 64 is turned on when the combustion start fails. The motor 41 (starter 31) can be operated with a minimum time lag for meshing with the ring gear 3.

  According to the present embodiment (the invention described in claim 4), the determination means predetermines an increase rate (predetermined value ΔN1) of the engine rotation speed at which the combustion start is successful, and an actual increase rate ΔNe of the engine rotation speed. Combustion start failed when the engine speed is less than the predetermined value (ΔN1), and the combustion start was successful when the actual engine speed increase rate ΔNe was equal to or greater than the predetermined value (ΔN1). (See step 6 in FIG. 3), it is possible to easily determine whether the combustion start has failed or succeeded.

  According to the present embodiment (the invention described in claim 5), the rate of increase Δup of the ring gear rotation speed that is increased by the combustion start by the combustion start means is calculated according to the engine coolant temperature (see FIG. 4). Even if the cooling water temperature of the engine is different, it is possible to accurately provide the increase rate Δup of the ring gear rotation speed that is increased by the combustion start.

  Next, FIG. 6 is a flowchart for explaining control of idle stop and subsequent restart of the second embodiment, which replaces FIG. 3 of the first embodiment. The same step numbers are assigned to the same portions as those in FIG. 3 of the first embodiment.

  The second embodiment proposes a method for determining whether or not the combustion start has failed, which is different from the first embodiment. The difference from the first embodiment will be mainly described. In step 21 of FIG. 6, the engine speed Ne is compared with a predetermined value N1, and if the engine speed Ne is equal to or higher than the predetermined value N1, the combustion start is successful. Conversely, when the engine rotational speed Ne is less than the predetermined value N1, it is determined that the combustion start has failed. Here, the predetermined value N1 is determined as follows. That is, as shown in FIG. 7, if the predetermined value N1 is provided at the position shown in the figure, the engine rotational speed Ne exceeds the value N1 when the combustion start is successful, and the combustion start fails. Since the engine speed does not exceed the value N1, if the engine start is successful when the engine speed Ne is equal to or higher than the predetermined value N1, conversely, if the engine speed Ne is less than the predetermined value N1, combustion occurs. It can be determined that startup has failed. FIG. 7 is basically the same as FIG.

  According to the second embodiment (the invention described in claim 4), as in the first embodiment, it is possible to obtain an operational effect that it is possible to easily determine whether the combustion start has failed or succeeded.

  The function of the pre-meshing means of claim 1 is shown in step 3 of FIG. 3, the function of the motor torque control means is shown in step 5 of FIG. 3, the function of the judging means is shown in step 6 of FIG. 3, and the function of the starter starting means is shown in FIG. Each of the three steps 7 is performed.

1 is a schematic configuration diagram of an in-cylinder direct injection engine according to an embodiment of the present invention. Detailed view of starter. The flowchart for demonstrating control of the idle stop of 1st Embodiment, and subsequent restart. The characteristic figure of the raise rate of a ring gear rotational speed. The timing chart which shows each change of the engine speed at the time of the combustion start succeeding at the time of the restart after the idle stop of 1st Embodiment, and a combustion start failure. The flowchart for demonstrating control of the idle stop of 2nd Embodiment, and subsequent restart. The timing chart which shows each change of the engine speed at the time of the combustion start succeeding at the time of the restart after the idle stop of 2nd Embodiment, and a combustion start failure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 3 Ring gear 11 Fuel injection valve 12 Ignition coil 21 Engine control unit 32 Starter control device 34 Battery 41 Motor 51 Magnet switch (meshing / disengaging mechanism)
64 pinion 71 shift lever 81 first relay 82 second relay 83 voltage control device

Claims (5)

A fuel injection valve that directly injects fuel into the combustion chamber;
In an engine provided with a spark plug for igniting the fuel injected by the fuel injection valve for each cylinder,
Combustion starting means for starting the engine by rotating a crankshaft by fuel injection and fuel ignition by the fuel injection valve and the spark plug in a specific cylinder;
A starter including a motor that generates torque, and a meshing / separating mechanism that meshes a pinion with a ring gear that moves integrally with a crankshaft or disengages the pinion from the ring gear;
Pre-meshing means for meshing a pinion with a ring gear using the meshing / detaching mechanism prior to combustion start by the combustion start means;
Motor torque control means for performing torque control using the motor so that the rate of increase of the ring gear rotation speed that is rotationally increased by combustion start by the combustion start means is the same as the rate of increase of the pinion rotation speed;
Determination means for determining whether the combustion start by the combustion start means has failed or succeeded;
Start of engine characterized by comprising: starter starting means for stopping torque control using the motor by the motor torque control means and starting the engine by the motor when combustion start fails from the determination result. apparatus.   When the combustion start is successful based on the determination result, the torque control using the motor by the motor torque control unit is stopped, and the pinion and the ring gear are engaged using the engagement / disengagement mechanism by the pre-engagement unit. The engine starting device according to claim 1, wherein the unpinning pinion is separated from the ring gear. A voltage control device for producing a voltage to be applied to the motor by adjusting a battery voltage;
2. The motor torque control unit according to claim 1, wherein when the combustion start fails, the motor torque control unit stops adjusting the battery voltage by the voltage control device so that the battery voltage is directly applied to the motor. Engine starter.   The determination means predetermines a rate of increase in engine speed at which combustion start is successful or engine speed at which combustion start is successful, and determines a rate of increase in actual engine speed or actual engine speed as this predetermined value. When combustion start fails when less than a certain value, it is determined that combustion start is successful when the rate of increase in actual engine speed or the actual engine speed exceeds a predetermined value. The engine starting device according to claim 1.   2. The engine starting device according to claim 1, wherein a rate of increase in a ring gear rotation speed that is increased by combustion starting by the combustion starting means is calculated in accordance with an engine water temperature.

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