JP2015140688A - Idling stop system control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an idling stop system control device capable of promptly restarting an engine if a request to restart the engine is issued after idling stop.SOLUTION: After the supply of a fuel is stopped, when an engine restart request is issued during the rotation of inertia of an engine, a control device determines whether to assist a starter motor in restarting the engine on the basis of a difference between the rotational speed of a ring gear synchronized with a crankshaft and the rotational speed of a pinion gear of the starter motor (steps 307 and 308) until the fuel is supplied to the engine and a cylinder to which the fuel is supplied first reaches an expansion stroke after the supply of the fuel (step 306), engages the ring gear with the pinion gear if determining assisting in restarting the engine (steps 309 and 310), and assists restarting of the engine by driving the starter motor (step 311).

Description

  The present invention relates to a control device for an idle stop system that automatically stops and restarts an engine.

  In recent years, automobile technologies aimed at saving energy resources and protecting the environment have been developed. For example, there is a vehicle equipped with an idle stop system that stops fuel supplied to an engine and loses torque generated by the engine when a predetermined condition (automatic stop condition) is satisfied during operation. The engine automatic stop condition is satisfied when the driver removes his or her foot from the accelerator or steps on the brake.

  In this idle stop system, even if the vehicle is not stopped, the engine is automatically stopped when the engine automatic stop condition is satisfied. Thereafter, when a request for restarting the engine (restart request) occurs during the engine inertia rotation period until the crankshaft of the engine stops rotating, it is required to restart the engine as soon as possible. The restart request is, for example, that the driver removes his foot from the brake pedal.

  As a technique for satisfying this requirement, for example, when a restart request is generated during an engine inertia rotation period immediately after an idle stop request is generated, the fuel that has been stopped is supplied again to the engine, so that the combustion recovery is resumed. A technique for starting is mentioned. Here, depending on the state of the engine, if the combustion is not performed well and it is difficult to restart the combustion, it is determined by the starter based on the rotation speed of the ring gear when the first cylinder to which fuel is supplied again is after the expansion stroke. As start assist, starter assist restart is performed by driving the starter (see, for example, Patent Document 1).

Patent No. 5094889

  Due to the above background, in an idle stop system, when a restart request is generated during an engine inertia rotation period immediately after the occurrence of an idle stop request, it is required to restart the engine as soon as possible. However, in the conventional idle stop system described above, the starter assist is performed during the engine inertia rotation period immediately after the occurrence of the idle stop request, because the first cylinder to which fuel is supplied again is after the expansion stroke. There was a risk of a long restart time. The present invention has been made in view of such a point, and an object of the present invention is to provide an idle engine that can promptly restart the engine when an engine restart request is generated after the idle stop. It is to provide a control device for a stop system.

  In order to solve the above problems, the control device for the idle stop system according to the present invention supplies fuel to the engine when the engine is requested to restart during engine inertia after the fuel supply is stopped. The engine with the starter motor is based on the difference between the rotation speed of the ring gear synchronized with the crankshaft and the rotation speed of the starter pinion gear until the first supplied cylinder reaches the expansion stroke after fuel supply. When it is determined whether or not to perform the restart assist, and when it is determined to perform the restart assist by the starter motor, the ring gear is engaged with the pinion gear and the starter motor is driven to restart the engine. Assist.

  According to the present invention, when an engine restart request is generated after an idle stop, the engine can be restarted promptly.

It is the schematic diagram which showed the apparatus structure and circuit connection state of the idle stop system which concern on 1st Embodiment of this invention. It is a control block diagram of the control apparatus which controls the idle stop system which concerns on 1st Embodiment of this invention. It is a flowchart of the control apparatus shown in FIG. It is the figure which showed the timing chart of the idle stop system shown in FIG. It is a control block diagram of the control apparatus which controls the idle stop system which concerns on 2nd Embodiment of this invention. It is a flowchart of the control apparatus shown in FIG. It is the figure which showed the timing chart of the idle stop system shown in FIG.

The present invention is illustrated by the following two embodiments.
[First Embodiment]
FIG. 1 is a schematic diagram showing a device configuration and a circuit connection state of an idle stop system 1 according to the first embodiment of the present invention. In this embodiment, the idle stop system 1 includes an engine (not shown) whose crankshaft rotates by supplying fuel, a starter 101 that assists in starting the engine, and a control device 108 that controls the starter 101 and the engine. And.

  A starter 101 according to the present embodiment is a so-called pinion gear push-out type starter. Specifically, a starter motor 105 that assists engine start, a pinion gear 103 that is rotationally driven by the starter motor 105, and a pinion gear 103 And a magnet switch 102 for pushing out at least.

  The rotation of the starter motor 105 is decelerated by a reduction mechanism inside the starter motor 105. As a result, the torque of the starter motor 105 is increased and transmitted to the pinion gear 103. The starter motor 105 has a structure in which when the magnet switch 102 is energized, the pinion gear 103 is pushed out (right direction in FIG. 1) and is engaged with the ring gear 104. Here, the ring gear 104 is synchronized with the rotation of the crankshaft of the engine and is attached to the crankshaft. In addition, as long as it has the function to push out the pinion gear 103, it is not limited to a magnet switch like this embodiment.

  The pinion gear 103 is integrated with the one-way clutch 107. As described above, the pinion gear 103 has a structure that can move in the axial direction of the starter motor 105 by energizing the magnet switch 102 from the control device 108. The pinion gear 103 can transmit power to the engine by meshing with the ring gear 104 connected to the crankshaft of the engine and rotating.

  The one-way clutch 107 is configured such that power is transmitted only in the direction in which the starter motor 105 rotates the engine forward. As a result, when the pinion gear 103 is engaged with the ring gear 104, the rotational speed of the ring gear 104 becomes the synchronous rotational speed corresponding to the reduction ratio with respect to the rotational speed of the starter motor 105, or It will be faster than.

  That is, if the ring gear 104 attempts to decrease below the rotational speed of the pinion gear 103, the one-way clutch 107 transmits power, so the rotational speed of the ring gear 104 does not fall below the synchronous rotational speed for the starter motor 105. On the other hand, when the rotational speed of the ring gear is higher than the synchronous rotational speed, the power is not transmitted from the ring gear 104 to the starter motor 105 side because the one-way clutch does not transmit power.

  As shown in FIG. 1, the idle stop system 1 includes an engine whose crankshaft rotates by supplying fuel, a ring gear 104 synchronized with the rotation of the crankshaft, a starter motor 105 that assists engine start, A pinion gear 103 that is engaged with the ring gear 104 and driven to rotate by a starter motor 105 when assisting the start of the engine is provided.

  As shown in FIG. 1, signals from the crank angle sensor 109 (engine speed detector, crank angle detector), signals from the pinion speed sensor 110 (pinion speed detector), the brake switch 111, and the vehicle speed sensor 112 are controlled. Input to the device 108. Since the ring gear 104 and the engine crankshaft are connected, the ring gear rotation speed and the crankshaft rotation speed (engine rotation speed) are synonymous.

  The control device 108 performs normal fuel injection control (control of the fuel injection valve), ignition (control of the spark plug), and air control (control of the electronic control throttle). In addition to this, the control device 108 determines whether the idle stop condition is satisfied from various information (vehicle driving state) such as a brake pedal state based on a signal from the brake switch and a vehicle speed from the vehicle speed sensor 112. Here, when the idle stop condition is satisfied, the engine is allowed to be idle stopped, and the fuel injection valve is controlled to stop the fuel supply to the engine, thereby automatically stopping the engine (the idle stop is performed). ).

  When an engine restart request is generated from the vehicle operating state described above, the control device restarts the fuel supply to the engine by controlling the fuel injection valve, and controls the spark plug to control the ignition timing. To control. In this way, engine restart control is executed.

  The control device 108 outputs a pinion push command signal and a motor rotation command signal independently. As shown in FIG. 1, a magnet switch energizing switch 106a for transmitting a pinion push command signal and a starter motor energizing switch 106b for transmitting a motor rotation command signal control the pushing of the pinion gear 103 and the rotation of the starter motor 105. As the magnet switch energizing switch 106a and the starter motor energizing switch 106b, for example, a relay switch having a mechanical contact, a switch using a semiconductor, or the like can be used.

  In the idle stop system 1 having such a device configuration, the control device 108 performs the following control. FIG. 2 is a control block diagram of a control device that controls the idle stop system according to the first embodiment of the present invention.

  The control device 108 shown in FIG. 1 inputs an output signal of a sensor for detecting the driving state of the vehicle described above via an A / D converter, and based on the input data and data stored in advance in a memory or the like. The idle stop system 1 is controlled by performing the calculation shown in FIG. 4 by the CPU and outputting a control signal via the A / D converter.

  As a software configuration, the control device 108 includes at least control blocks as shown in FIG. Specifically, the idle stop determination unit 201 determines whether or not the vehicle has an idle stop condition based on a vehicle speed signal from a vehicle speed sensor, a brake switch signal, a ring gear rotation speed, and the like. The fuel supply stop unit 202 stops the fuel supply to the engine when the idle stop determination unit 201 satisfies the idle stop condition. Specifically, the fuel injection valve is controlled so that fuel is not burned in the engine. At this time, the spark plug may be controlled so as to stop ignition by the spark plug as necessary.

  Here, when the fuel supply to the engine is stopped by the fuel supply stop unit 202, the engine speed decreases. Therefore, inertial rotation determination unit 203 determines whether the engine is inertially rotating when the engine restart request is made. Specifically, the fuel supply stop unit 202 determines whether or not the engine inertia is rotating from when the fuel supply is stopped until the rotation of the crankshaft (engine) is stopped. More specifically, it is determined whether or not the engine inertia is rotating based on the ring gear rotation speed (engine rotation speed) or the amount of change (degree of change in crank angle).

  Here, whether or not an engine restart request has been made is determined by the restart request determination unit 204 based on a brake switch signal or the like. For example, when the brake switch is off, it is determined that an engine restart request has been made. The combustion return unit 205 controls the fuel injection amount, the ignition timing, and the intake air amount to control the fuel injection amount, the fuel ignition plug, and the throttle valve when the above-described combustion return condition is satisfied. Output a control signal. When the inertia rotation determination unit 203 determines that the engine inertia is rotating, the combustion recovery unit 205 supplies fuel to the engine and burns the supplied fuel.

  The restart assist determination unit 207 is a period until the cylinder to which fuel is first supplied by the combustion return unit 205 reaches the expansion stroke after the fuel supply (specifically, the expansion stroke reaches the engine rotation speed). Then, based on the rotational speed difference between the rotational speed of the ring gear and the rotational speed of the pinion gear, it is determined whether or not the starter 101 assists in restarting the engine. Here, the rotation speed difference between the rotation speed of the ring gear and the rotation speed of the pinion gear is calculated by the rotation speed difference calculation section 206, and when this rotation speed difference becomes a predetermined value or less, the restart assist determination section. Reference numeral 207 outputs a restart assist permission signal from the starter 101.

  The restart assist unit 208 assists restart of the engine by causing the ring gear 104 to be engaged with the pinion gear 103 and driving the starter motor 105 at the timing when the restart assist permission signal is output. Specifically, the restart assist unit 208 outputs a pinion push command signal and a motor rotation command signal, and controls the magnet switch energization switch 106a and the starter motor energization switch 106b. Thereby, an engine restart assist is executed.

  Even when the inertial rotation determination unit 203 determines that the engine inertial rotation is not being performed, if the restart request determination unit 204 satisfies the restart request condition, normal restart assist is performed. At this time, the restart assist determination unit 207 does not determine the restart assist, and the restart assist unit 208 performs the combustion return by the combustion return unit 205 while assisting the engine restart by the starter.

  3 is a flowchart of the control device shown in FIG. 2, and FIG. 4 is a diagram showing a timing chart of the idle stop system shown in FIG. As shown in FIG. 3, when the idle stop determination unit 201 first determines that the idle stop condition is satisfied in step 301, the process proceeds to step 302. In step 302, the fuel supply stop unit 202 stops the fuel supply in accordance with the establishment of the idle stop condition, and the process proceeds to step 303. At this time, as shown in FIG. 4, at time t1, the fuel supply stop flag changes from Low to High. As a result, the engine rotation starts inertial rotation.

  In step 303, the restart request determination unit 204 determines whether a restart request has occurred. If it is determined in step 303 that a restart request has occurred (time t2 in FIG. 4), the process proceeds to step 304, where inertial rotation determination unit 203 determines whether engine inertial rotation is in progress. Whether or not the engine is in inertial rotation may be determined, for example, from the engine speed or from the degree of change in the crank angle.

  Here, when it is determined that the restart request is determined by the restart request determination unit 204 and the inertia rotation determination unit 203 determines in step 304 that the engine inertia is not rotating, the engine speed and the rotation speed of the pinion gear are Since both are 0 r / min and are synchronized, the routine proceeds to step 318 and normal restart control is performed.

  In normal restart control, as described above, the magnet switch 102 is energized to push out the pinion gear 103 and mesh with the ring gear 104 by the push command signal from the restart assist unit 208. Next, the starter motor 105 is energized by a motor rotation command signal from the restart assist unit 208. As a result, the engine is cranked, fuel supply is restarted (returns to combustion) by the combustion return unit 205, and the engine is restarted.

  On the other hand, if it is determined in step 304 that the engine inertia is rotating, the process proceeds to step 305, the fuel supply is restarted by the combustion return unit 205, and the process proceeds to step 306. In step 306, it is determined whether the read timing of the engine speed Ne1 has been reached.

  Specifically, the reading timing of the engine speed Ne1 is assumed to be the timing after the expansion stroke of the crank angle of the cylinder in which fuel supply is first resumed. That is, even if the fuel supply is resumed in step 305 and restarting by combustion is requested, the engine speed does not increase immediately, but a certain period must be waited. For example, in the case of a PFI engine that injects fuel into an intake port, from the resumption of fuel supply to the expansion stroke in which combustion torque can be obtained from the intake stroke in which fuel is injected in the cylinder in which fuel was initially injected. This is because it takes time.

  Until now, in the cylinder to which fuel is first supplied, the engine speed Ne1 is read after the expansion stroke after the fuel is burned by the spark plug. Therefore, the starter assists using the read timing. In this case, the restarting timing by the starter is delayed. Therefore, in the present embodiment, until the cylinder to which fuel is first supplied by the combustion return unit 205 reaches the expansion stroke after the fuel supply (specifically, No in step 306, that is, reading of the engine speed). If not, it is determined whether or not the starter assists in restarting the engine, and this is executed.

  If the condition for the reading timing of the engine speed Ne1 is not satisfied in step 306, the process proceeds to step 307. In step 307, the rotation speed difference calculation unit 206 calculates the rotation speed difference (Ne−Np) between the engine rotation speed Ne and the pinion rotation speed Np, and the restart assist determination unit 207 calculates the rotation speed difference (Ne). It is determined whether or not (−Np) is equal to or smaller than the pinion extrusion permission rotational speed difference PIJDG1.

  When this condition is satisfied ((Ne−Np) ≦ PIJDG1), the process proceeds to step 308. In step 308, the restart assist determination unit 207 determines starter assist start, and the process proceeds to step 309. In step 309, the restart assist unit 208 energizes the magnet switch 102 for pushing out the pinion gear 103 (time t3 in FIG. 4).

  In this way, when the pinion gear 103 is pushed out toward the ring gear 104 in a state where the rotational speed difference is small, the impact when the pinion gear 103 and the ring gear 104 are engaged is alleviated, and the collision sound and the engagement sound are generated. This reduces the wear of the pinion gear 103 and the ring gear 104.

  Next, at step 310, the restart assist unit 208 determines whether or not the pinion gear 103 is engaged with the ring gear 104. The biting determination may be determined as biting completed after a predetermined time (period from time t3 to time t4 in FIG. 4) has elapsed since the start of pinion push energization in step 309. That is, the period from time t3 to time t4 is the time from the start of pinion push energization until the pinion gear 103 moves to reach the ring gear 104 and bite into the ring gear. Alternatively, a sensor that can detect that the pinion gear 103 and the ring gear 104 have been engaged may be provided, and it may be determined that the engagement has been completed based on the output value of the sensor. If the condition is satisfied (time t4 in FIG. 4), the starter motor is energized in step 311 to crank the engine and restart it.

  On the other hand, in step 306, it is determined whether the read timing of the engine speed Ne1 has been reached. If the condition is satisfied (time t5 in FIG. 4), the process proceeds to step 312. That is, when this condition is satisfied, the first cylinder to which fuel has been supplied again is in the state after the expansion stroke. In step 312, the combustion return unit 205 determines whether the engine speed Ne1 exceeds the combustion return determination reference value NeJDG. If this condition is satisfied (Ne1> NeJDG), the process proceeds to step 317 to start combustion return. Determine and restart only by combustion.

  On the other hand, when the engine speed Ne1 is equal to or lower than NeJDG at step 312 (Ne1 ≦ NeJDG), the restart assist determination unit 207 determines that the pre-rotation starter assist start is performed, and the starter motor 105 is energized at step 314. As a result, the pinion gear 103 starts rotating, and the rotational speed of the pinion gear 103 increases.

  Next, at step 315, the restart assist determination unit 207 determines whether or not the difference between the engine speed Ne and the rotation speed Np of the pinion gear 103 is equal to or smaller than the pinion extrusion permission speed difference PIJDG2. When the condition is satisfied ((Ne−Np) ≦ PIJDG2), the process proceeds to step 316, and the restart assist unit 208 stops energization of the starter motor 105. Next, in step 309, the magnet switch 102 for pushing out the pinion gear 103 is energized.

  As a result, the pinion gear 103 is pushed out toward the ring gear 104 in a state where the rotational speed difference is small, so that the impact when the pinion gear 103 and the ring gear 104 are engaged is alleviated, and the collision sound and the engagement sound are reduced. In addition, wear of the pinion gear 103 and the ring gear 104 can be reduced.

  Next, at step 310, it is determined whether or not the pinion gear 103 is engaged with the ring gear 104 as described above. If the condition is met, the starter motor is energized in step 311 to crank the engine and restart it.

  In the conventional method, start-up by the starter assist is executed after waiting for the engine speed Ne1 timing at time t5 in FIG. 4, that is, when the first cylinder to which fuel is supplied again is after the expansion stroke. On the other hand, in the system of the present embodiment, from the resumption of fuel supply to the expansion stroke in which combustion torque can be obtained from the intake stroke in which fuel is injected in the cylinder in which fuel is initially injected (see FIG. 4 is determined to be starter assist (at time t3 in FIG. 4), and start-up by starter assist is executed. For this reason, the restart time is shortened at least for the period from time t3 to time t5 in FIG.

  In this way, in the present embodiment, when the idle stop is performed, the fuel supply is stopped, and then the fuel supply is resumed when a restart request is generated during the engine inertia rotation period immediately after the idle stop request is generated. it can. Then, based on the rotation speed of the ring gear when the first cylinder to which the fuel is supplied is after the expansion stroke, the rotation speed of the ring gear and the rotation of the pinion gear are determined before determining whether to start combustion recovery or to start the pre-rotation starter assist. When the number difference is equal to or smaller than the predetermined value, it is determined that the starter assist is started, and the engine can be restarted promptly by the starter assist.

[Second Embodiment]
FIG. 5 is a control block diagram of a control device that controls the idle stop system according to the second embodiment of the present invention. The control device according to the second embodiment is different from the control device according to the first embodiment in that, as shown in FIG. Further, a pinion pre-rotation unit 209 that pre-rotates the pinion gear before being engaged with the ring gear by energizing the starter motor before supplying the fuel is provided.

  6 is a flowchart of the control device shown in FIG. 5, and FIG. 7 is a timing chart of the idle stop system shown in FIG. Note that a part of the description common to the flowchart of the control device according to the first embodiment is omitted.

  As shown in FIG. 6, when the idle stop determination unit 201 first determines in step 601 that the idle stop condition is satisfied, the process proceeds to step 602. In step 602, the fuel supply stop unit 202 stops the fuel supply in accordance with the establishment of the idle stop condition, and the process proceeds to step 603. At this time, as shown in FIG. 7, at time t1, the fuel supply stop flag changes from Low to High. As a result, the engine rotation starts inertial rotation.

  Thereafter, in step 603, the pinion pre-rotation unit 209 determines a pinion pre-rotation start condition, and if this start condition is satisfied, the process proceeds to step 604. In step 604, the pinion pre-rotation unit 209 executes pinion pre-rotation control. As the determination of the pinion pre-rotation start condition, for example, the condition is that the engine speed is equal to or lower than a predetermined speed. In the pinion pre-rotation control, the starter motor 105 is energized (time ts1 in FIG. 7).

  As a result, the pinion gear 103 starts rotating, and the rotation speed of the pinion 103 increases. In this specification, the rotation of the starter motor by energization before the ring gear is engaged is referred to as “pre-rotation”. Next, when the starter motor is de-energized at the timing when the pinion rotation speed reaches a predetermined rotation speed or higher (time ts2 in FIG. 7), the pinion gear continues to rotate freely.

  In step 605, the restart request determination unit 204 determines whether a restart request has occurred. If it is determined in step 605 that a restart request has been generated (time t2 in FIG. 7), the process proceeds to step 606, and inertial rotation determination unit 203 determines whether or not engine inertial rotation is in progress. Whether or not the engine is in inertial rotation may be determined, for example, from the engine speed or from the degree of change in the crank angle.

  If it is determined that the engine inertia is not rotating, the process proceeds to step 620 to determine whether or not the pinion inertia is rotating. Whether or not the pinion inertial rotation is being performed may be determined from, for example, the pinion rotational speed, or may be determined from the elapsed time from the start of energization of the starter motor.

  When the pinion inertia rotation is not being performed, the engine rotation speed and the rotation speed of the pinion gear are both 0 r / min and are synchronized with each other. Therefore, the process proceeds to step 621 and normal restart control is performed. In normal restart control, as described above, the magnet switch 102 is energized to push out the pinion gear 103 and mesh with the ring gear 104 by the push command signal from the restart assist unit 208. Next, the starter motor 105 is energized by a motor rotation command signal from the restart assist unit 208. As a result, the engine is cranked, fuel supply is restarted (returns to combustion) by the combustion return unit 205, and the engine is restarted.

  On the other hand, if it is determined in step 606 that the engine inertia is rotating, the process proceeds to step 607, the fuel supply is restarted by the combustion return unit 205, and the process proceeds to step 608. In step 608, it is determined whether the read timing of the engine speed Ne1 has been reached.

  Until the cylinder to which the fuel is first supplied by the combustion return unit 205 reaches the expansion stroke after the fuel supply (specifically, No in step 608, that is, when the engine speed is not read). The restart assist determination unit 207 determines whether or not to assist the restart of the engine by the starter.

  If it is determined in step 608 that the condition for reading the engine speed Ne1 is not satisfied, the process proceeds to step 609. In step 609, the rotation speed difference calculation unit 206 calculates the rotation speed difference between the engine rotation speed Ne and the pinion rotation speed Np, and the restart assist determination unit 207 determines that the calculated rotation speed difference (Ne−Np) is a pinion. It is determined whether or not the extrusion-permitted rotation speed difference PIJDG2 or less.

  When this condition is satisfied ((Ne−Np) ≦ PIJDG2), the process proceeds to step 610. In step 610, the restart assist determination unit 207 determines starter assist start, and the process proceeds to step 611. In step 611, the restart assist unit 208 energizes the magnet switch 102 for pushing out the pinion gear 103 (time t3 in FIG. 7).

  In this way, when the pinion gear 103 is pushed out toward the ring gear 104 in a state where the rotational speed difference is small, the impact when the pinion gear 103 and the ring gear 104 are engaged is alleviated, and the collision sound and the engagement sound are generated. This reduces the wear of the pinion gear 103 and the ring gear 104.

  Next, at step 612, the restart assist unit 208 determines whether or not the pinion gear 103 is engaged with the ring gear 104. The biting determination may be determined as biting completion after a predetermined time (period from time t3 to time t4 in FIG. 7) has elapsed since the start of energization of pinion in step 612. That is, the period from time t3 to time t4 is the time from the start of pinion push energization until the pinion gear 103 moves to reach the ring gear 104 and bite into the ring gear. Alternatively, a sensor that can detect that the pinion gear 103 and the ring gear 104 have been engaged may be provided, and it may be determined that the engagement has been completed based on the output value of the sensor. If the condition is satisfied (time t4 in FIG. 7), the starter motor is energized in step 613 to crank the engine and restart it.

  As described above, in this embodiment, the pinion pre-rotation unit 209 energizes the starter motor after the fuel supply stop unit 202 stops supplying the fuel and before the fuel return unit 205 supplies the fuel. Thus, the pinion gear 103 is pre-rotated. As a result, the pinion gear 103 can be engaged with the ring gear 104 at an earlier stage, and cranking can be started more quickly.

  Further, the pinion pre-rotation unit 209 energizes the starter motor 105 based on the timing when the rotation speed of the pinion gear 103 reaches a predetermined rotation speed or more, or the timing when the starter motor 105 is energized for a predetermined time. Since the process is completed, the pinion gear 103 can be efficiently engaged with the ring gear 104.

  The engine to which the present invention can be applied is not limited to the in-cylinder fuel injection type engine, but is an intake port type engine that injects fuel into the intake port, or a dual fuel injection type that uses both the intake port and in-cylinder fuel injection. It can also be applied to other engines. Further, the number of cylinders and the engine type (V type or horizontal opposing type) are not limited and can be applied.

  The embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

1: Idle stop system 101: Starter 102: Magnet switch 103: Pinion gear 104: Ring gear 105: Starter motor 106a: Magnet switch energizing switch 106b: Starter motor energizing switch 107: One-way clutch 108: Controller 109: Crank angle Sensor 110: Pinion rotation sensor 111: Brake switch 112: Vehicle speed sensor 201: Idle stop determination unit 202: Fuel supply stop unit 203: Inertia rotation determination unit 204: Restart request determination unit 205: Combustion return unit 206: Speed difference calculation Unit 207: restart assist determination unit 208: restart assist unit 209: pinion pre-rotation unit t1: fuel injection stop timing t2: restart request generation timing and fuel supply restart timing t3: pinion push And timing t4: completion timing biting and cranking start timing t5: Ne1 read timing ts1: starter motor energization start timing ts2: starter motor application end timing Ne: engine speed (the ring gear rotation speed)
Np: rotational speed of pinion gear Ne1: engine rotational speed PIJDG1: pinion extrusion allowable rotational speed difference PIJDG2: pinion extrusion allowable rotational speed difference NeJDG: combustion Return criterion value

Claims (3)

An engine whose crankshaft rotates by supplying fuel;
A ring gear synchronized with the rotation of the crankshaft;
A starter motor that assists in starting the engine;
A pinion gear that engages with the ring gear when assisting the start of the engine and is rotationally driven by the starter motor;
A rotational speed detection device for detecting the rotational speed of the ring gear and the pinion gear,
A control device for an idle stop system that automatically stops the engine by stopping the supply of fuel to the engine when a predetermined idle stop condition is satisfied during the engine operation,
The control device includes: a fuel supply stop unit that stops supplying fuel to the engine when the predetermined idle stop condition is satisfied during the engine operation;
Inertia for determining whether or not the engine is rotating during the period from when the fuel supply is stopped by the fuel supply stop unit until the rotation of the crankshaft is stopped when the engine restart request is made A rotation determination unit;
A combustion return unit that supplies fuel to the engine and burns the supplied fuel when the inertial rotation determination unit determines that the engine is in inertial rotation;
Based on the rotational speed difference between the rotational speed of the ring gear and the rotational speed of the pinion gear until the cylinder to which fuel is first supplied by the combustion return portion reaches the expansion stroke after the fuel supply, the starter A restart assist determination unit that determines whether or not to assist engine restart by a motor;
When the restart assist determination unit determines to perform engine restart assist by the starter motor, the ring gear is engaged with the pinion gear, and the starter motor is driven to restart the engine. An idle stop system control device comprising at least a restart assist unit for assisting.   A pinion pre-rotation unit that pre-rotates the pinion gear by energizing the starter motor during a period from when the fuel supply is stopped by the fuel supply stop unit to when fuel is supplied by the combustion return unit. The control device for an idle stop system according to claim 1, further comprising:   The pinion pre-rotation unit ends energization of the starter motor based on a timing at which the rotation speed of the pinion gear reaches a predetermined rotation speed or more or a timing at which a predetermined time has elapsed after energizing the starter motor. The control apparatus for an idle stop system according to claim 2.

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