JP2013194584A - Starting device of vehicle-mounted engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a starting device of a vehicle-mounted engine capable of properly choosing and using two starting motors when a starting request of a driver is present and when the starting request is absent in restarting an engine during idle stop.SOLUTION: A starting device of a vehicle-mounted engine includes: a low-speed type starting motor 36a relatively large in rotation of a motor output shaft with respect to rotation of a crankshaft 3; a high-speed type starting motor 28 relatively small in rotation of the motor output shaft with respect to the rotation of the crankshaft 3; and a restart control means to restart an engine 1 by driving the low-speed type starting motor 36a and the high-speed type starting motor 28 when a starting request of a driver is present in restarting the engine 1, and to restart the engine 1 by driving only the high-speed type starting motor 28 when the starting request of the driver is absent.

Description

  The present invention relates to a starter for a vehicle-mounted engine that restarts the engine when a predetermined restart condition is satisfied during automatic engine stop, and particularly to a starter for a vehicle-mounted engine that includes two starter motors.

Conventionally, in order to improve fuel consumption and reduce CO ₂ , the engine automatically stops when a predetermined automatic stop condition is satisfied, and then restarts when the predetermined restart condition is satisfied. A vehicle equipped with a stop function is known.

  For example, in Patent Document 1, a gear type starter that rotates a crankshaft by temporarily engaging a pinion gear with a ring gear connected to the crankshaft and driving the motor, and a crank pulley provided on the opposite side of the ring gear. A belt-type starter that rotates the crankshaft by driving the motor through a belt and a starter pulley, and when the torque required for starting the engine is large, the gear-type starter and the belt-type starter are allowed to cooperate with each other Is described.

JP 2003-328907 A (paragraphs 0003, 0007, 0031)

  By the way, as the engine restart condition during idling stop, for example, the difference between the set temperature of the air conditioner and the cabin temperature, for example, including the driver's start request, such as the driver depressing the accelerator pedal, has become larger Some do not include a driver's start request, such as the need to operate an air conditioner. When the driver is requested to start when the engine is restarted, quick engine start is required, and when there is no driver start request, quietness and low vibration are required.

  Therefore, the present invention provides a starter for a vehicle-mounted engine that can properly use the two starter motors when the driver is requested to start and when the engine is in an idle stop state. The purpose is to provide.

  In order to solve the above-mentioned problems, the present invention provides a starter for a vehicle-mounted engine that restarts an engine that is automatically stopped when a predetermined restart condition is satisfied, and includes a motor output shaft that rotates against rotation of a crankshaft. If there is a driver's start request at the time of restarting the engine, a low-speed start motor with relatively high rotation, a high-speed start motor with relatively little rotation of the motor output shaft relative to the rotation of the crankshaft, Restart control means for driving the low-speed start motor and the high-speed start motor to restart the engine, and when there is no driver's start request, restarts the engine by driving only the high-speed start motor And a starting device for a vehicle-mounted engine (claim 1).

  According to the present invention, when restarting the engine that is automatically stopped, if there is a driver's start request, the two low-speed and high-speed starter motors are driven, so that the engine can be started quickly. On the other hand, when the driver does not request to start, only the high-speed type starter motor is driven, so that the number of rotations of the starter motor is relatively reduced and the quietness at the start is ensured.

  In the present invention, the restart control means drives the low-speed start motor and the high-speed start motor to restart the engine when there is a driver's start request and the degree is relatively large. It is preferable that the engine is started and the engine is restarted by driving only the high-speed starter motor when there is a driver's start request and the degree is relatively small (Claim 2).

  According to this configuration, when the degree of the driver's start request is relatively small, priority is given to ensuring quietness at the start rather than quick startability of the engine.

  In the present invention, the restart control means is configured so that the driver's start request is relatively small when the driver's start request is not present or when the driver's start request is relatively small. Therefore, it is preferable to delay the start of fuel supply (claim 3).

  According to this configuration, when there is no driver's start request or when the driver's start request is relatively small, combustion starts after the engine rotation is increased, so that the combustion is stable and the emission performance is improved. Will improve. Further, since combustion starts after exceeding the resonance frequency of the engine, low vibration characteristics and low noise characteristics at the time of starting are ensured.

  In the present invention, the restart control means starts the fuel supply together with the start of driving of the starter motor when the degree of the driver's start request is relatively large, or when the driver does not request start When the degree of the start request is relatively small, it is preferable to start the fuel supply when the engine speed exceeds a predetermined value.

  According to this configuration, when there is no driver's start request or when the driver's start request is relatively small, combustion starts after the engine speed reaches a predetermined value or more, so combustion is stabilized. , Emission performance is improved. Further, since combustion starts after exceeding the resonance frequency of the engine, low vibration characteristics and low noise characteristics at the time of starting are ensured.

  In the present invention, the low-speed type starter motor is a gear-type starter motor that temporarily engages the motor-side gear with the crankshaft-side gear to rotate the crankshaft, and the high-speed type starter motor includes a motor-side rotating body and A winding transmission type starter motor that rotates a crankshaft via a winding member wound around a crankshaft-side rotating body, and the restart control means is provided in advance when there is a driver's start request. It is preferable that after the driving of the low speed type starting motor is started, the driving of the high speed type starting motor is started with a delay.

  According to this configuration, when there is a driver's start request, driving of the gear type starter motor is started first, so that the motor side gear and the crankshaft side gear can be meshed in a stopped state, and the gear type The driving of the starting motor can be started smoothly. Moreover, since the drive of the winding transmission type starter motor is started in a state where the crankshaft is rotating, the slipping of the winding member can be suppressed. Furthermore, compared with the case where the drive of the high speed type starter motor is started without delay, the drive time of the high speed type starter motor is shortened, so that power consumption can be reduced. On the other hand, since the low-speed start motor and the high-speed start motor are driven together, the start time is shortened and the quick start performance is maintained.

  In the present invention, it is preferable that the high-speed starter motor is a motor generator driven by an engine via a winding member.

  According to this configuration, since the motor generator that generates power using kinetic energy during deceleration and braking is also used as the high-speed starter motor, the number of parts can be reduced.

  In the present invention, the restart control means, when there is a driver's start request, delays after starting one of the low-speed start motor and the high-speed start motor first. It is preferable to shorten the time for starting the drive of the other starter motor as the start of the other starter motor is started and the start request of the driver is larger.

  According to this configuration, when the driver requests to start, the drive time of the other starter motor is shortened compared to the case where the drive of the other starter motor is started without delay. That's it. On the other hand, since the low-speed start motor and the high-speed start motor are driven together, the start time is shortened and the quick start performance is maintained. In addition, the engine can be started more quickly as the driver's start request is greater.

  According to the present invention, when there is a driver's start request, the engine can be started quickly, and when there is no driver's start request, quietness at start-up, low vibration, and low noise can be achieved. Therefore, a starter for a vehicle-mounted engine that is excellent in starting efficiency and merchantability is provided.

1 is an overall configuration diagram of an engine mounted on a vehicle according to an embodiment of the present invention. It is a whole block diagram when the said engine is seen from upper direction regarding FIG. It is a whole block diagram of the electric system of the said vehicle. It is a control system figure of the engine. It is a time chart which shows the rotation change at the time of the restart of the said engine in case the driver | operator's start request | requirement degree is comparatively large. It is a time chart which shows the rotation change at the time of the restart of the said engine when the driver | operator's start request | requirement degree is relatively small. It is a time chart which shows the rotation change at the time of the restart of the said engine when there is no driver | operator's start request | requirement. It is a flowchart of the engine automatic stop control in the idle stop function mounted in the vehicle. It is a part of flowchart of the engine restart control in the said idle stop function. It is the remaining part of the flowchart of FIG.

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

(1) Overall Configuration The vehicle-mounted engine 1 according to the embodiment of the present invention shown in FIG. 1 is a 4-cycle spark ignition gasoline engine, and includes a cylinder head 10 and a cylinder block 11. As shown in FIG. 2, the engine 1 is formed with a first cylinder 12A, a second cylinder 12B, a third cylinder 12C, and a fourth cylinder 12D in order from one end side of the engine 1. As shown in FIG. 1, a piston 13 connected to the crankshaft 3 by a connecting rod (not shown) is fitted into each cylinder 12 </ b> A to 12 </ b> D, and a combustion chamber 14 is formed above the piston 13. As the crankshaft 3 rotates, the pistons 13 of the cylinders 12A to 12D reciprocate up and down with a phase difference of 180 ° (180 ° CA).

  In the present embodiment, intake, compression, expansion, and exhaust strokes are performed in the order of the first cylinder 12A, the third cylinder 12C, the fourth cylinder 12D, and the second cylinder 12B.

  A spark plug 15 and a fuel injection valve 16 are provided in the cylinder head 10. The electrode of the spark plug 15 faces the combustion chamber 14 at the top of the combustion chamber 14. The spark plug 15 is driven by an ignition device 27. The fuel injection valve 16 directly injects fuel from the side of the combustion chamber 14 into the combustion chamber 14. The fuel injection valve 16 incorporates a needle valve and a solenoid (not shown), and opens for a time corresponding to the pulse width of the pulse signal input from the engine control unit 100 shown in FIG. As a result, an amount of fuel corresponding to the opening time of the fuel injection valve 16 is injected toward the vicinity of the electrode of the spark plug 15.

  The cylinder head 10 is provided with an intake port 17 and an exhaust port 18 that open to the combustion chamber 14. An intake passage 21 and an exhaust passage 22 are connected to the intake port 17 and the exhaust port 18, and an intake valve 19 and an exhaust valve 20 are disposed at a connection portion between the intake port 17 and the exhaust port 18 and the combustion chamber 14. ing.

  As shown in FIG. 2, the intake passage 21 includes a common intake passage 21c, a surge tank 21b, and an independent intake passage 21a for each of the cylinders 12A to 12D in order from the upstream side. A throttle body 24 is provided in the common intake passage 21c, and the throttle body 24 is provided with a throttle valve 24a capable of adjusting the amount of air flowing into each of the cylinders 12A to 12D, and an actuator 24b for driving the throttle valve 24a. ing. In the vicinity of the throttle body 24, an idling rotation speed control device (ISC) 24c is disposed. The ISC 24c is of an electromagnetic drive type in which the valve opening amount can be changed by the engine control unit 100 shown in FIG. An air flow sensor 25 for detecting the intake flow rate is disposed upstream of the throttle valve 24a, and an intake pressure sensor 26 for detecting intake pressure is disposed downstream of the throttle valve 24a.

  As shown in FIG. 1, the engine 1 includes a motor generator 28 connected to the crankshaft 3 by a timing belt 4. The timing belt 4 is wound around a crankshaft side pulley 3 a assembled to the crankshaft 3 and a motor generator side pulley 28 b assembled to a drive shaft 28 a of the motor generator 28. The motor generator 28 includes a regulator circuit 28c that adjusts the amount of power generation by adjusting the output voltage by controlling the current of a field coil (not shown). The motor generator 28 generates an amount of electricity corresponding to the vehicle electrical load 82 and the voltage of the battery 6 shown in FIG. 3 based on the control signal input to the regulator circuit 28c from the engine control unit 100 shown in FIG. To do.

  The motor generator 28 is driven by the engine 1 through a timing belt 4 wound around a motor generator pulley 28b and a crankshaft pulley 3a, and generates electric power using kinetic energy during deceleration and braking. In addition, it is also used as a winding transmission type starter motor that rotates (cranks) the crankshaft 3 via the timing belt 4 wound around the motor generator side pulley 28b and the crankshaft side pulley 3a. The motor generator 28 constitutes a “high-speed starter motor” in the claims.

  As will be described in detail later, since the motor generator 28 that generates power using kinetic energy during deceleration and braking is also used as a high-speed starter motor, there is an advantage that the number of parts can be reduced.

  As shown in FIG. 1, the engine 1 includes a starter 36 that is used to start the engine 1. The starter 36 has a starter motor 36a and a pinion gear 36d. The rotation shaft of the pinion gear 36d is coaxial with the output shaft of the starter motor 36a and can reciprocate along the rotation shaft. A flywheel (not shown) is connected to the crankshaft 3, and a ring gear 35 is fixed to the flywheel. When the engine 1 is started using the starter 36, the pinion gear 36d moves to a predetermined meshing position and meshes with the ring gear 35 temporarily. Then, when the pinion gear 36d is driven by the starter motor 36a, the crankshaft 3 is rotated (cranked).

  The starter motor 36a is a gear-type starter motor that rotates the crankshaft 3 by temporarily engaging the pinion gear 36d with the ring gear 35, and constitutes a “low speed starter motor” in the claims.

  Comparing the reduction ratio when the motor generator 28 functions as a starter motor and the reduction ratio of the starter motor 36a, the reduction ratio between the motor generator side pulley 28b and the crankshaft side pulley 3a is the same as that of the pinion gear 36d. It is set to a value smaller than the reduction ratio with the ring gear 35. Therefore, the rotation of the output shaft of the starter motor 36a (low speed type starter motor) relative to the rotation of the crankshaft 3 is relatively increased, and the rotation of the drive shaft 28a of the motor generator 28 (high speed type starter motor) relative to the rotation of the crankshaft 3. Is relatively less.

  The form in which the engine 1 is started by the starter 36 is roughly divided into two. One is a mode in which the driver operates the ignition key switch (IG key switch) 38 shown in FIG. 4 to drive the starter 36, thereby starting the engine 1. This is called “key start”. In the idle stop function, the engine control unit 100 shown in FIG. 4 automatically drives the starter 36 when the engine 1 is restarted after the automatic stop, thereby starting the engine 1. This is referred to as “automatic restart” or simply “restart”.

  In addition, the “restart” of the engine 1 includes a difference between a restart due to a driver's start request, for example, a driver depressing an accelerator pedal (not shown), and a set temperature of an air conditioner and a passenger compartment temperature, for example. There is a restart that does not depend on the driver's start request, such as the necessity of operating the air conditioner because it has become larger. When the driver is requested to start when the engine 1 is restarted, quick engine start is required, and when there is no driver start request, quietness and low vibration are required.

  As shown in FIG. 1, the engine 1 includes two crank angle sensors 30 and 31 that detect the rotation angle of the crankshaft 3. Based on the detection signal (pulse signal) output from one crank angle sensor 30, the engine speed (that is, the engine speed or the engine speed) is detected. The rotation angle of the crankshaft 3 is detected on the basis of detection signals (pulse signals) output from the crank angle sensors 30 and 31 that are out of phase with each other.

  As shown in FIG. 1, the engine 1 includes a cam angle sensor 32 that detects the rotational position of the intake camshaft and a water temperature sensor 33 that detects the temperature of the cooling water of the engine 1.

  The vehicle according to the present embodiment is a front-engine / front-drive (FF) vehicle in which the output shaft (crankshaft 3) of the engine 1 extends in the vehicle body width direction. As shown in FIG. 3, the vehicle according to the present embodiment is an AT vehicle in which the automatic transmission 2 is connected to the output shaft of the engine 1. The rotation of the engine 1 is transmitted to the left and right front wheels (not shown) via the automatic transmission 2 and a differential (not shown).

(2) Electric system Next, with reference to FIG. 3, the electric system of the vehicle which concerns on this embodiment is demonstrated.

  As shown in FIG. 3, the electric system of the vehicle includes a vehicle electric load 82 composed of various lights, an air conditioner, instruments, and the like, and a DC / DC interposed between the vehicle electric load 82 and the motor generator 28. The converter 5 and the battery 6 which consists of a lead acid battery which supplies electric power to the said vehicle electric load 82 are included. A starter 36 is also connected to the battery 6.

  As described above, the motor generator 28 is connected to the output shaft (crankshaft 3) of the engine 1 via the timing belt 4 wound around the motor generator side pulley 28b and the crankshaft side pulley 3a.

  A capacitor unit 29 that stores regenerative power generated by the motor generator 28 during deceleration and braking of the vehicle is connected in series with the motor generator 28.

  The capacitor unit 29 is formed by connecting a plurality (for example, 10) of capacitor cells (not shown) made of a single electric double layer capacitor in series. Each capacitor cell has an internal resistance. The resistance value of the internal resistor is generally about 1 mΩ when new. When the capacitor unit 29 is normal, the maximum voltage of the entire capacitor unit 29 is 25.2V. An appropriate number of capacitor cells can be selected according to the situation. The maximum voltage (25.2V) of the entire capacitor unit 29 is larger than the voltage of the battery 6 (for example, 12V).

  During deceleration and braking of the vehicle, the motor generator 28 functions as a generator by regenerative braking. The output voltage of motor generator 28 is converted from an AC voltage to a desired DC voltage by inverter 28d. The regenerative power is supplied to the capacitor unit 29 and also to the battery 6 via the DC / DC converter 5 as a voltage converter.

  The electric power stored in the capacitor unit 29 is transferred to the battery 6 through the DC / DC converter 5. The DC / DC converter 5 has a step-down converter function from the capacitor unit 29 side to the battery 6 side.

  By charging the battery 6 with the electric power stored in the capacitor unit 29, the electric power stored in the capacitor unit 29 can be effectively used. In addition, since the capacitor voltage decreases due to the power supply to the battery 6, the progress of the deterioration of the capacitor unit 29 is suppressed.

  When the engine 1 is “key-started” again after the IG key switch 38 shown in FIG. 4 is turned off, power is supplied from the battery 6 to the starter 36 or the motor generator 28. As a result, the starter motor 36a or the motor generator 28 is driven, and the crankshaft 3 is rotated.

  After the engine 1 is “key-started”, the electric power stored in the capacitor unit 29 is used to drive the motor generator 28. Thereby, in the idle stop function, when the engine 1 that is automatically stopped is “restarted”, the electric power remaining in the capacitor unit 29 can be used. Thereby, consumption of the battery 6 is suppressed.

  Electric power generation by the motor generator 28 is basically performed only when the vehicle is decelerated and braked, and the electric power is intensively charged in the capacitor unit 29. Thereby, the energy at the time of deceleration and braking is recovered as regenerative power. The motor generator 28 includes an inverter 28d that converts the generated AC power into DC power. The electric power generated by the motor generator 28 is sent to the capacitor unit 29 after being converted into direct current by the inverter 28d. Capacitor unit 29 can be charged up to about 25 V, and the electric power generated by motor generator 28 exceeding this amount is supplied to battery via DC / DC converter 5 (after being stepped down by DC / DC converter 5). 6 is sent.

  On the other hand, in an operating state other than during deceleration / braking (during idling, steady running, or acceleration), the motor generator 28 basically does not generate power. That is, the electric power charged in the capacitor unit 29 when the vehicle is decelerated and braked is sequentially sent to the battery 6 through the DC / DC converter 5 and stored there. In the driving state other than during deceleration and braking, the electric power stored in the battery 6 is supplied to the vehicle electrical load 82. Thereby, the electric power of the vehicle electrical load 82 is covered without operating the motor generator 28. Of course, depending on the driving scene of the vehicle, power generation by the motor generator 28 may be temporarily performed in an operating state other than during deceleration and braking.

  Here, as described above, the capacitor unit 29 in which a plurality of electric double layer capacitors are connected in series and the battery 6 made of a lead storage battery are used in combination with each of the characteristics of the capacitor unit 29 and the battery 6. This is to efficiently recover the energy during deceleration and braking. That is, since the capacitor unit 29 physically stores electric charges like a capacitor, it can receive a large current instantaneously, and the electric power generated intensively by the motor generator 28 during deceleration and braking can be obtained. Suitable for temporarily storing electricity. On the other hand, the battery 6 is a power storage device using a chemical reaction, and cannot handle a temporary large current, but has a property that the charging capacity is larger than that of the capacitor unit 29. Therefore, the electric power generated by the motor generator 28 is once stored in the capacitor unit 29 and then sent to the battery 6 having a large capacity. Note that the electric power stored in the capacitor unit 29 may be directly supplied to the vehicle electrical load 82 without going through the battery 6.

(3) Control System (3-1) System Configuration FIG. 4 is a control system diagram centering on the engine control unit 100 of the vehicle according to the present embodiment.

  The engine control unit 100 receives signals from the air flow sensor 25, the intake pressure sensor 26, the crank angle sensors 30, 31, the cam angle sensor 32, the water temperature sensor 33, the IG key switch 38, and the like described above. The engine control unit 100 further includes an accelerator opening sensor 34 that detects the opening degree of an accelerator pedal that is depressed by a driver, and a brake that detects ON / OFF of a brake pedal (not shown) (that is, whether or not a brake is applied). Signals are also input from the sensor 37 and a vehicle speed sensor 39 that detects the vehicle speed of the vehicle.

  The engine control unit 100 outputs control signals to the DC / DC converter 5, the fuel injection valve 16, the actuator 24b of the throttle valve 24a, the ignition device 27, the motor generator 28, the starter motor 36a, the vehicle electric load 82, and the like described above. To do.

  The engine control unit 100 is constituted by a microprocessor having a CPU, a memory, a counter timer group, an interface, and a bus connecting them. The engine control unit 100 logically configures an operating state determination unit 101, a combustion control unit 102, a starter control unit 103, a motor generator control unit 104, an electric load control unit 106, and an idle stop control unit 107.

  The operating state determination unit 101 is configured to control each cylinder 12A to 12D based on sensor signals from the air flow sensor 25, the intake pressure sensor 26, the crank angle sensors 30, 31, the cam angle sensor 32, the water temperature sensor 33, and the accelerator opening sensor 34. Various operating states are determined such as the position of the piston 13, the in-cylinder temperatures of the cylinders 12 </ b> A to 12 </ b> D, or whether the engine 1 is rotating forward. The operating state determination unit 101 calculates the position of the piston 13 based on signals from the crank angle sensors 30 and 31, and determines the stop position of each piston 13 when the engine 1 is automatically stopped. .

  Combustion control unit 102 performs proper throttle opening of engine 1 based on signals from air flow sensor 25, intake pressure sensor 26, crank angle sensors 30 and 31, cam angle sensor 32, water temperature sensor 33, and accelerator opening sensor 34. The control signal is output to the fuel injection valve 16, the actuator 24b of the throttle valve 24a, and the ignition device 27.

  The starter control unit 103 outputs a control signal to the starter 36 to drive the starter motor 36 a during “key start” and “restart” of the engine 1.

  The motor generator control unit 104 sets an appropriate power generation amount of the motor generator 28 and outputs the drive signal to the regulator circuit 28c. Usually, a target value (for example, 13 V) of the output voltage (regulated voltage) is set, and the power generation amount is feedback-controlled so that the target value is maintained even if the engine rotation or the like fluctuates.

  The electric load control unit 106 operates the vehicle electric load 82 or changes the operating state of the vehicle electric load 82 based on the switch operation of the driver or the passenger or automatically. The vehicle electrical load 82 includes, for example, an airbag control unit, an electrohydraulic power steering control unit, a navigation system, an audio system, various meters, various lights, and a defogger, in addition to those already described. The electric load control unit 105 restricts power supply to the vehicle electric load 82 as necessary in order to secure more power supply to the starter 36 when the starter 36 is driven.

  The idle stop control unit 107 realizes an idle stop function that automatically stops the engine 1 when a predetermined automatic stop condition is satisfied, and then restarts the engine 1 when a predetermined restart condition is satisfied.

  The engine control unit 100 constitutes “restart control means” in the claims.

(3-2) Characteristic Operation and Action Characteristic operation performed by the engine control unit 100 will be described. 5-7 is a time chart which shows the rotation change at the time of restart of the engine 1 which concerns on this embodiment.

  When a predetermined automatic stop condition is satisfied, such as when the vehicle speed is substantially zero while the driver depresses the brake pedal, the idle stop function is activated and the engine 1 is automatically stopped. If a predetermined restart condition is satisfied during the automatic stop of the engine 1, the idle stop function is canceled and the engine 1 is restarted.

  As described above, as a restart condition of the engine 1 during the idle stop, for example, the difference between the set temperature of the air conditioner and the vehicle interior temperature, for example, including the driver's start request such as the driver depressing the accelerator pedal. There are some that do not include the driver's start request, such as the need to operate the air conditioner because it has become larger. When the driver is requested to start when the engine 1 is restarted, quick engine start is required, and when there is no driver start request, quietness and low vibration are required.

  Therefore, in the present embodiment, when restarting the engine 1 during idle stop, the two starter motors, the motor generator 28 and the starter motor 36a, are used properly depending on whether the driver has a start request or not. I made it. Further, in the present embodiment, the motor generator is generated even when the driver has a start request and the degree thereof is relatively large, and when the driver has a start request and the degree is relatively small. The two starter motors 28 and starter motor 36a are used properly. The degree of the driver's start request can be determined by, for example, whether or not the accelerator pedal is depressed, the depression amount when the accelerator pedal is depressed, and the like.

[When there is a driver's start request and the degree is relatively large]
For example, as shown in FIG. 5, when the driver releases the brake pedal and the degree of the driver's start request is relatively large, such as when the amount of depression of the accelerator pedal is relatively large, the starter motor Both the motor 36a and the motor generator 28 are driven to restart the engine 1. Thereby, the engine 1 can be started quickly.

  In addition, fuel supply is started and combustion is started at the start of driving of the starter motors 36a and 28 (in the figure, Δ marks indicate fuel injection. The same applies to FIGS. 6 and 7). Thereby, the engine 1 can be started more rapidly. Since the starter motor 36a is a low-speed starter motor and the motor generator 28 is a high-speed starter motor, the starter motor 36a is stopped driving at a relatively early time point t1, and the motor generator 28 is moved at a relatively late time point. The drive is stopped at t2.

  Although starter motor 36a and motor generator 28 may be started simultaneously, it is preferable to start driving motor generator 28 with a delay after starting starter motor 36a first. Since the drive of the starter motor 36a is started first, the pinion gear 36d and the ring gear 35 can be engaged in a stopped state, and the drive of the starter motor 36a that is a gear type starter motor can be started smoothly. Further, since the driving of the motor generator 28, which is a winding transmission type starting motor, is started while the crankshaft 3 is rotating, the slip of the timing belt 4 can be suppressed. Furthermore, since the driving time of the motor generator 28 is shortened compared to the case where the driving of the motor generator 28 is started without delay, the power consumption can be reduced. On the other hand, since the starter motor 36a and the motor generator 28 are driven together, the starting time is shortened and the quick startability is maintained.

  In addition, when starting the motor generator 28 with a delay after starting the starter motor 36a, the time for delaying the start of the driving of the motor generator 28 is shortened as the degree of the driver's start request increases. Is preferred. There is an advantage that the engine 1 can be started more quickly as the degree of the driver's start request is larger.

[When there is a driver's start request and the degree is relatively small]
For example, in the case where the degree of the driver's start request is relatively small, such as when the driver only depresses the brake pedal and does not depress the accelerator pedal, or the amount of depression of the accelerator pedal is relatively small, FIG. As shown, the engine 1 is restarted by driving only the motor generator 28. Thereby, priority is given to ensuring the quietness at the time of starting rather than the quick startability of the engine 1.

  The reason why the motor generator 28 is excellent in quietness is that, as described above, the rotation of the drive shaft 28a of the motor generator 28 relative to the rotation of the crankshaft 3 is relatively small, and the drive type is winding by the belt 4 and the pulleys 3a and 28b. It depends on the hanging transmission type. Since the increase in engine rotation is slower than in the case of FIG. 5, the motor generator 28 stops driving at a time point t3 that is later than the time point t2 in FIG.

[When there is no driver's start request]
For example, when the engine 1 is restarted for system reasons, such as when it is necessary to operate the air conditioner or when the idle stop time has taken a long time, there is no request for the driver to start. In this case, as shown in FIG. 7, only the motor generator 28 is driven to restart the engine 1. Thereby, priority is given to ensuring the quietness at the time of starting rather than the quick startability of the engine 1. Since the driver does not know that the engine 1 is restarted, the advantage of ensuring the quietness at the start is great.

  Further, the fuel supply is not started when the motor generator 28 starts to be driven, but is started after a predetermined time delay. Alternatively, it is started when the engine rotation becomes a predetermined rotation (for example, 400 to 500 rpm) or more. As a result, combustion starts after the resonance frequency of the engine 1 (for example, 200 to 300 Hz) is exceeded, so that low vibration characteristics and low noise characteristics during starting are ensured. In this case, since the driver does not know that the engine 1 is restarted, there is a great advantage that low vibration characteristics and low noise characteristics at the time of starting are ensured. In addition, since combustion starts after the engine speed rises and exceeds a predetermined speed, there is an advantage that combustion is stabilized and emission performance is improved. Since the increase in engine rotation is slower than in the case of FIG. 6, the motor generator 28 is stopped from driving at time t4 that is later than time t3 in FIG.

(3-3) Control Operation Next, a specific operation of the idle stop control performed by the engine control unit 100 will be described with reference to a flowchart.

[Automatic stop control]
The automatic stop control of the engine 1 is executed according to the flowchart shown in FIG. When this control starts, the engine control unit 100 reads various sensor values in step S1, and then determines in step S2 whether or not an automatic stop condition for the engine 1 is satisfied.

  In the present embodiment, the engine control unit 100 is configured such that the IG key switch 38 is ON, a travel range such as the D range is selected, the vehicle speed is equal to or lower than a predetermined vehicle speed (the vehicle speed is zero or the vehicle The automatic stop condition is satisfied when all of that the brake depression amount is equal to or greater than the predetermined depression amount (the brake hydraulic pressure is equal to or greater than the predetermined hydraulic pressure) are satisfied. Is determined.

  As a result, when it is determined that the automatic stop condition is satisfied, the engine control unit 100 starts the fuel cut for stopping the fuel injection from the fuel injection valve 16 in step S3 and performs the throttle mainly for scavenging. The valve 24a is opened (the opening degree of the throttle valve 24a is made larger than the opening degree so far).

  Next, the engine control unit 100 determines in step S4 whether or not the engine rotation is equal to or less than the first predetermined rotation N1. As a result, when it is determined that the engine rotation is equal to or lower than the first predetermined rotation N1, the engine control unit 100 closes the throttle valve 24a in step S5 (the opening degree of the throttle valve 24a is larger than the opening degree until then). Small).

  Next, the engine control unit 100 determines in step S6 whether or not the engine 1 has completely stopped. As a result, when it is determined that the engine 1 has completely stopped, the engine control unit 100 stores the stop position of each piston 13 based on the signals from the crank angle sensors 30 and 31 in step S7. Then, this control ends.

[Restart control]
The restart control of the engine 1 is executed according to the flowcharts shown in FIGS. When this control is started, the engine control unit 100 reads various sensor values in step S11, and then determines whether or not a restart condition for the engine 1 is satisfied in step S12.

  In the present embodiment, the engine control unit 100 determines that the IG key switch 38 is ON, a travel range such as the D range is selected, the vehicle speed is equal to or lower than a predetermined vehicle speed, and a signal from the brake sensor 37. Is satisfied (the brake pedal is not depressed), it is determined that the restart condition is satisfied. That is, it is determined that the restart condition is satisfied when there is a driver's start request.

  In the present embodiment, in addition to the above requirements, for example, the engine control unit 100 has a system difference that, for example, the difference between the set temperature of the air conditioner and the vehicle interior temperature has increased, the idle stop time has taken a long time, etc. Even when the engine 1 needs to be restarted for the reason described above, it is determined that the restart condition is satisfied. That is, it is determined that the restart condition is satisfied even when the driver has not requested to start.

  As a result, when it is determined that the restart condition is satisfied, the engine control unit 100 determines in step S13 whether or not the signal from the brake sensor 37 is OFF (the brake pedal is not depressed). As a result, when it is determined that the signal from the brake sensor 37 is OFF, the engine control unit 100 determines whether or not the signal from the accelerator opening sensor 34 is ON (accelerator pedal depression) in step S14. judge. As a result, when it is determined that the signal from the accelerator opening sensor 34 is ON, the engine control unit 100 proceeds to step S15. This is a case where there is a driver's start request and the degree thereof is relatively large, and the control operation as shown in FIG. 5 is performed.

  On the other hand, as a result of the determination in step S14, when it is determined that the signal from the accelerator opening sensor 34 is OFF (accelerator pedal not depressed), the engine control unit 100 proceeds to step S22. This is a case where there is a driver's start request and the degree thereof is relatively small, and the control operation as shown in FIG. 6 is performed.

  On the other hand, as a result of the determination in step S13, when it is determined that the signal from the brake sensor 37 is ON (brake pedal depression), the engine control unit 100 proceeds to step S25. This is a case where there is no start request from the driver, and the control operation as shown in FIG. 7 is performed.

  When there is a driver's start request and the degree thereof is relatively large, the engine control unit 100 moves the piston to a stop-time expansion stroke cylinder (a cylinder that is in the expansion stroke during the automatic stop of the engine 1) in step S15. The amount of fuel set in consideration of the stop position of 13 is injected, and the starter motor 36a and the motor generator 28 are simultaneously driven.

  Next, in step S16, the engine control unit 100 ignites the stop-time expansion stroke cylinder at a timing set in consideration of the vaporization time of the injected fuel.

  Next, in step S17, the engine control unit 100 sequentially performs combustion for the other cylinders in the compression stroke, and in step S18, determines whether or not the engine rotation is equal to or higher than a third predetermined rotation N3 (for example, 300 rpm). judge. As a result, when it is determined that the engine rotation is equal to or higher than the third predetermined rotation N3, the engine control unit 100 stops driving the starter motor 36a in step S19 (time t1).

  Next, in step S20, the engine control unit 100 determines whether or not the engine rotation is equal to or higher than the idle rotation (for example, 700 rpm). As a result, when it is determined that the engine rotation is equal to or higher than the idle rotation, the engine control unit 100 stops the driving of the motor generator 28 in step S21 (time t2). Then, this control ends. Since the features and actions of this control operation have already been described with reference to FIG. 5, they will not be repeated here.

  On the other hand, when there is a driver's start request and the degree thereof is relatively small, the engine control unit 100 supplies the amount of fuel set in consideration of the stop position of the piston 13 to the stop-time expansion stroke cylinder in step S22. Injecting and driving of only the motor generator 28 is started.

  Next, in step S23, the engine control unit 100 ignites the stop-time expansion stroke cylinder at a timing set in consideration of the vaporization time of the injected fuel.

  Next, in step S24, the engine control unit 100 sequentially performs combustion on the other cylinders continuously in the compression stroke.

  Next, the engine control unit 100 determines in step S20 whether the engine rotation is equal to or higher than the idle rotation. As a result, when it is determined that the engine rotation is equal to or higher than the idle rotation, the engine control unit 100 stops the driving of the motor generator 28 in step S21 (time point t3). Then, this control ends. Since the features and functions of this control operation have already been described with reference to FIG. 6, they will not be repeated here.

  On the other hand, when there is no driver start request, the engine control unit 100 starts driving only the motor generator 28 in step S25.

  Next, in step S26, the engine control unit 100 determines whether or not the engine rotation is equal to or higher than a second predetermined rotation N2 (for example, 400 to 500 rpm). As a result, when it is determined that the engine rotation is equal to or higher than the second predetermined rotation N2, the engine control unit 100 injects an amount of fuel set in consideration of the engine torque to the next compression stroke cylinder in step S27.

  Next, in step S28, the engine control unit 100 ignites the compression stroke cylinder at a timing set in consideration of the vaporization time of the injected fuel.

  Next, in step S29, the engine control unit 100 sequentially performs combustion on the other cylinders continuously in the compression stroke.

  Next, the engine control unit 100 determines in step S20 whether the engine rotation is equal to or higher than the idle rotation. As a result, when it is determined that the engine rotation is equal to or higher than the idle rotation, the engine control unit 100 stops the driving of the motor generator 28 in step S21 (time t4). Then, this control ends. Since the features and actions of this control operation have already been described with reference to FIG. 7, they will not be repeated here.

(4) Other Modifications When the degree of the driver's start request is relatively small (see FIG. 6), the fuel supply is not started with the start of driving of the motor generator 28, but is delayed for a predetermined time, Or you may start when an engine rotation turns into more than predetermined rotation (for example, 400-500 rpm). As a result, combustion starts after the resonance frequency of the engine 1 (for example, 200 to 300 Hz) is exceeded, so that low vibration characteristics and low noise characteristics during starting are ensured. In addition, since combustion starts after the engine speed rises and exceeds a predetermined speed, there is an advantage that combustion is stabilized and emission performance is improved.

  The electric system (see FIG. 3) may be a single power supply system without the capacitor unit 29 depending on the situation. Or it can replace with the capacitor unit 29 and can also be set as the 2 power supply system which has a 2nd battery and has two batteries.

  The engine is not limited to a gasoline engine, and may be a compression self-ignition engine. Examples of compression self-ignition engines include diesel engines that burn light oil by self-ignition, and premixed compression ignition (HCCI) engines that self-ignite by compressing fuel containing gasoline at a high compression ratio. Etc.

1 Engine 3 Crankshaft 3a Crankshaft side pulley (Crankshaft side rotating body)
4 Timing belt (winding member)
28 Motor generator (high speed starter motor)
28a Motor generator drive shaft (motor output shaft)
28b Motor generator side pulley (motor side rotating body)
35 Ring gear (crankshaft side gear)
36a Starter motor (low speed starter motor)
36d Pinion gear (motor side gear)
100 engine control unit (restart control means)

Claims (7)

A starter for a vehicle-mounted engine that restarts an engine that is automatically stopped when a predetermined restart condition is satisfied,
A low speed starter motor in which the rotation of the motor output shaft relative to the rotation of the crankshaft is relatively large;
A high-speed starter motor in which the rotation of the motor output shaft relative to the rotation of the crankshaft is relatively small;
When there is a driver's start request when the engine is restarted, the engine is restarted by driving the low speed start motor and the high speed start motor, and when there is no driver start request, the high speed A vehicle-mounted engine starter characterized by comprising restart control means for driving only the mold starter motor to restart the engine. The starter for a vehicle-mounted engine according to claim 1,
The restart control means restarts the engine by driving the low-speed start motor and the high-speed start motor when there is a driver's start request and the degree is relatively large. A vehicle-mounted engine starter that drives only the high-speed start motor and restarts the engine when there is a start request from a person and the degree is relatively small. The starter for a vehicle-mounted engine according to claim 2,
The restart control means supplies fuel when there is no driver's start request or when the driver's start request is relatively small compared to when the driver's start request is relatively high. A starter for a vehicle-mounted engine characterized by delaying the start of the vehicle. The starter for a vehicle-mounted engine according to claim 3,
When the driver's start request is relatively large, the restart control means starts the fuel supply at the same time as the start of the driving of the starter motor, and when there is no driver start request or the driver's start request A starter for a vehicle-mounted engine, characterized in that, when the degree is relatively small, fuel supply is started when the engine rotation becomes equal to or higher than a predetermined rotation. The starter for a vehicle-mounted engine according to any one of claims 1 to 4,
The low-speed starter motor is a gear-type starter motor that rotates the crankshaft by temporarily engaging the motor-side gear with the crankshaft-side gear,
The high-speed type starter motor is a winding transmission type starter motor that rotates a crankshaft via a winding member wound around a motor side rotating body and a crankshaft side rotating body,
The restart control means, when there is a driver's start request, starts driving the low speed starter motor first and then starts driving the high speed starter motor with a delay. Engine starter. The starter for a vehicle-mounted engine according to any one of claims 1 to 5,
The high-speed starter motor is a motor generator driven by the engine via a winding member, and is a starter for a vehicle-mounted engine. The starter for a vehicle-mounted engine according to any one of claims 1 to 6,
When there is a driver's start request, the restart control means starts driving one of the low-speed start motor and the high-speed start motor first, and then delays the other start motor. The starter for a vehicle-mounted engine is characterized in that the time for delaying the start of driving of the other starter motor is shortened as the degree of the driver's start request increases.

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