JP4329268B2 - Engine control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention can automatically stop an automobile internal combustion engine (engine) during operation when there is no need for driving, while the engine does not stop completely when there is a need for driving. The present invention relates to an automatic stop / restart control device for an automobile engine that can be automatically restarted.
[0002]
[Prior art]
In an automobile that uses an engine as a driving power source, the lockup clutch provided in the torque converter of the automatic transmission is engaged during deceleration when the vehicle speed is gradually decreasing because the driver does not step on the accelerator pedal. By combining, the crankshaft of the engine and the transmission of the automatic transmission device are directly connected, and by stopping the supply of fuel to the engine, fuel consumption is maintained while maintaining engine rotation by driving from the drive wheel side. A device for saving the above has been conventionally known as described in, for example, Japanese Patent Application Laid-Open No. 58-166165. In the conventional system, when the engine speed is reduced to a predetermined value higher than the idle speed in such a fuel cut state, the lock-up clutch is released and the fuel is released to prevent engine stall. It is customary to resume the supply.
[0003]
In order to further reduce the fuel consumption as compared with the prior art, the automatic engine start / stop device described in Japanese Patent Laid-Open No. 8-189395 discloses a fuel cut for performing fuel cut control of the engine. Even if the condition is not satisfied, the fuel cut control is executed when the automatic engine stop condition is satisfied, and the clutch is in the engaged state during this period. If the clutch release condition is satisfied while the automatic stop condition is satisfied, the engine is controlled to be automatically stopped by releasing the clutch.
[0004]
However, in this improved prior art, when the fuel consumption is reduced by extending the engine speed range for fuel cut to a low speed range, after the engine speed suddenly drops due to braking, etc. Even if the supply of fuel is resumed in an attempt to re-accelerate, the engine speed is low, so it is highly likely that the fuel will not be easily ignited and an engine stall will occur. When ignition becomes impossible in this way, it is necessary to restart the engine by the starter. However, in the conventional starter that engages with the ring gear of the engine only when starting, the pinion pops out even at low speed. While the gear rotates with the crankshaft, it is difficult for the pinion to mesh with the ring gear. Therefore, it is necessary to wait for the engine to completely stop and perform a restart operation. Therefore, since the vehicle cannot be restarted immediately and accelerated, the driver feels uncomfortable and the driving feeling deteriorates.
[0005]
Further, in the control device described in Japanese Patent Application Laid-Open No. 2-200538, a starter generator is incorporated in the engine, and a function as a motor for driving the engine in the engine and power generation that receives the driving force of the engine to generate electric power. In addition to having functions as a machine, these functions are switched and controlled according to the operating state. When releasing the lock-up clutch and ending maintenance of the engine by the drive wheels, the engine speed is reduced to a predetermined value or less by supplying power to the starter generator instead and operating it as a starter motor. Therefore, when the lockup clutch is released, the power is always supplied to the device regardless of whether or not the device needs to be restarted. There is a problem of wasting power when there is no need for starting.
[0006]
[Problems to be solved by the invention]
The present invention addresses the aforementioned problems in the prior art. Yu And avoid wasting power and thus fuel Providing an automatic stop / restart control device for an engine It is an object.
[0007]
[Means for Solving the Problems]
The present invention provides an engine automatic stop / restart control device according to claim 1 as means for solving the above-mentioned problems.
[0008]
The engine automatic stop / restart control means in the control device of the present invention automatically shuts off the fuel supply to the engine when the deceleration of the vehicle is detected when the accelerator opening becomes zero. Stop. However, the rotation of the engine can be maintained by reversely driving the engine from the drive wheel side by interlocking the crankshaft and the drive wheel by intermittent transmission means such as a lock-up clutch.
[0009]
In such a state, when the accelerator pedal (or the equivalent) is depressed by the driver (including the autopilot) for re-acceleration and the accelerator opening is increased, the engine automatic stop / restart control is performed. The means restarts the fuel supply by the fuel injection control means, and when the rotational speed detected by the engine rotational speed detection means is higher than a predetermined value, the torque applying means such as the starting motor is not operated, Restart by supplying only. However, when the rotational speed is lower than the predetermined value, the torque applying means is immediately operated to restart. However, if the engine is not restarted, the restarting operation is repeated again by the torque applying means. . As a result, the engine can be restarted quickly and reliably, and the energy consumed by the torque applying means is reduced, so that the driving feeling can be improved while avoiding waste of fuel. Various problems in the conventional technology can be solved.
[0010]
Thus, it is determined whether or not the torque applying means is operated depending on whether the engine speed is higher or lower than the predetermined value. However, when the engine speed is lower than the predetermined value, the fuel supply is performed first. The torque applying means may be operated only when the engine speed is restarted and no increase in the engine speed is detected within a predetermined time. In any case, in such a case, when setting a predetermined value of the engine speed that is a threshold value for determining whether or not to actuate the torque applying means, at least the engine warm temperature such as the cooling water temperature is set. One of an index indicating the machine state and an index indicating the magnitude of the engine load such as the speed of decrease in the rotational speed can be considered.
[0011]
In the control device of the present invention, a one-way clutch can be provided between the torque applying means and the crankshaft of the engine. As a result, when the rotation speed of the crankshaft exceeds that of the starter motor after the restart is completed, the one-way clutch runs idle, so that the starter motor does not hinder the rotation of the crankshaft.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows, as an embodiment of the present invention, a system configuration of mainly a drive unit and a control unit thereof for an automobile equipped with an automatic engine stop / restart control unit. In FIG. 1, 1 is an engine body, 2 is a crankshaft of the engine 1, 3 is a crank pulley attached to one end of the crankshaft 2, 4 is a generator such as an alternator driven by the crankshaft 2, and 5 is power generation. A battery charged by the electric power generated by the machine 4, a compressor for an air conditioner driven by the engine 1, and a starter motor (starter) 7 provided as a part of the automatic starter of the engine 1. .
[0013]
In the case of the illustrated embodiment, in addition to the crank pulley 3 that is directly connected to the crankshaft 2 on the drive side, the generator 4 on the driven side, and the pulley of the compressor 6 for the air conditioner, the drive shaft of the starter 7 The attached pulleys 34 are all interlocked by a single belt 8, and the plurality of pulleys and a single belt 8, which is a flexible winding transmission element, are connected to the crankshaft 2. The power transmission mechanism 9 that can always be driven is configured. The belt 8 of the power transmission mechanism 9 can be replaced with a chain or the like that is a functionally equivalent transmission component. As the starter 7, a type in which a pinion pops out by a solenoid while the engine 1 is stopped and engages with a ring gear attached to the crankshaft 2 of the engine 1 is not suitable as the starter 7. . In some cases, since the generator 4 is omitted, the starter 7 can also be used as a generator.
[0014]
Reference numeral 10 denotes left and right drive wheels of the automobile, 11 denotes left and right axles connected to them, and 12 denotes an automatic transmission device provided in a main power transmission system from the crankshaft 2 to the drive wheels 10 of the engine 1. ing. The structure of the automatic transmission 12 is well known, and a hydraulic torque converter 13 in which a pump and a turbine are opposed to a portion for receiving power from the crankshaft 2 of the engine 1, and Subsequently, a transmission 14 including a plurality of gear trains, hydraulic clutches, and the like, and in this case, a final reduction gear 15 including a differential gear train is provided.
[0015]
The automatic transmission device 12 includes a lock-up clutch 16 that is mechanically transmitted directly by short-circuiting the torque converter 13 so that power loss due to the fluid of the torque converter 13 is reduced in a high-speed steady running state or the like. Although provided in parallel with the converter 13, in the system illustrated in FIG. 1, the transmission state between the crankshaft 2 of the engine 1 and the axle 11 of the drive wheel 10 is arbitrarily directly connected in the deceleration state of the automobile. As a direct-coupled transmission means that can be controlled automatically, it is used for the purpose of the present invention. Further, the transmission 14 can be arbitrarily controlled to a neutral state by the transmission device control means 18, and power transmission between the crankshaft 2 of the engine 1 and the axle 11 of the drive wheel can be cut off.
[0016]
The automatic transmission 12 according to the present invention is not limited to the one provided with the fluid torque converter 13 as illustrated in FIG. 1, but generally, at least the power transmission is interrupted by the electronic control means. Any automatic transmission device can be used as long as it is in a neutral state (a state where at least transmission of torque from the axle 11 toward the crankshaft 2 is blocked) and a directly connected state. Accordingly, for example, in the automatic transmission 12 that does not include a torque converter but always includes a direct-coupled transmission, a control clutch such as an electromagnetic clutch that can be controlled by electronic control means is provided in the transmission. 14 is connected in series after or before the one corresponding to No. 14, and this clutch controls the transmission state between the crankshaft 2 and the axle 11 of the drive wheel 10 to be directly connected or disconnected.
[0017]
Reference numeral 17 shown in FIG. 1 denotes an electronic control unit (ECU) which is the center of the entire system of the automatic stop / restart control device for the engine 1 of the present invention, and should be called an engine automatic stop / restart control means. Is. The control device 17 also includes at least one microprocessor, memories such as ROM and RAM, a clock device, an input / output port, and the like, as in a normal ECU. A command for causing a function specific to the present invention is formed by a calculation performed based on a signal input to the control device 17 from a detection unit such as a sensor or a switch, a map set in the ROM, and the like. . For this purpose, the control device 17 receives signals indicating the operating states of the engine 1 and the vehicle from several detection means provided in each part of the vehicle and the engine 1, and a large number of calculation result commands (control signals) are related. It is output toward the control means which is an individual driving device of the device.
An electric negative pressure pump 43 communicates with the brake system 45 and is driven by the battery 5 to ensure a predetermined negative pressure while the engine 1 is stopped under the command of the control device 17. The An electric hydraulic pump 42 is driven to ensure a predetermined hydraulic pressure for the hydraulic control mechanism 44 while the engine 1 is stopped. When the engine 1 is rotating, the negative pressure of the brake system 45 is secured by the intake negative pressure of the engine. The hydraulic pressure of the hydraulic control mechanism 44 is supplied by a hydraulic pump (not shown) attached to the crankshaft 2 of the engine 1.
[0018]
In the system illustrated in FIG. 1, reference numeral 18 denotes control means for the automatic transmission 12 as one of control means for driving a target device in response to a command from the control device 17. The control means 18 controls the automatic transmission mechanism 12 by issuing a command to the hydraulic control mechanism 44. In the same way as a normal one, the gear train of the transmission 14 is switched by operating a hydraulic clutch or the like inside the transmission device 12, and a command from the control device 17 is accepted at any time to lock the direct transmission mechanism. The up-clutch 16 can be intermittently controlled, and has a built-in control means for the intermittent transmission means. This control means is a means for intermittently connecting the above-described series-connected control clutch. Reference numeral 19 denotes a normal engine ECU and control means (E / G-ECU) of the engine main body 1 such as a drive device that operates according to its command. The fuel injection control means for controlling the fuel injected into the engine 1 Contains. Reference numeral 20 denotes a control means for a starter motor (starter) 7. When the power of the battery 5 is supplied to the starter 7 by its operation, the starter 7 is an engine even if the engine 1 is not completely stopped. One crankshaft 2 can be driven to perform a restart operation. The starter control means 20 constitutes an automatic starter together with a starter motor (starter) 7.
[0019]
FIG. 1 also illustrates several detection means for detecting and inputting to the control device 17 signals indicating the operating states of the engine 1 and the automobile necessary for the control device 17 to perform control. First, reference numeral 23 denotes acceleration / deceleration detecting means for detecting the acceleration and deceleration of the automobile, but it is not necessary to provide a dedicated sensor or the like, and a normal vehicle speed sensor for measuring the rotation speed (rotational speed) of the axle 11 or the like. Since the acceleration or deceleration of the automobile can be obtained by calculating the signal in the control device 17, a part of the vehicle speed sensor and the control device 17 serves as the acceleration / deceleration detecting means 23.
[0020]
Reference numeral 24 denotes brake depression amount detection means for detecting the depression amount of a brake pedal (not shown) operated by the driver of the automobile (brake stroke or brake depression angle, and in some cases, the magnitude of the depression force of the brake). It may be something like a potentiometer (variable resistor) attached to the rotating shaft of the brake pedal. Reference numeral 25 denotes a means for detecting the amount of depression of the accelerator pedal (accelerator opening) by the driver. In the embodiment, it is not necessary to accurately detect the depression amount of the accelerator pedal, and it is sufficient if it is possible to detect whether or not the depression amount exceeds a predetermined value. Therefore, the detection means 25 is a switch linked to the accelerator pedal, that is, It can be an accelerator switch. In FIG. 1, reference numeral 41 denotes a remaining battery level detecting means for detecting the remaining electric energy of the battery 5, and reference numeral 46 denotes a warm-up state such as a cooling water temperature sensor or an engine oil temperature sensor for detecting the warm-up state of the engine. It is a detection means.
[0021]
Further, as a detecting means mounted on a normal automobile and usable for the purpose of the present invention, reference numeral 30 denotes a detecting means for detecting the operating state of the parking brake. Since this may be a switch that is turned on when the parking brake is in the engaged state, this type of switch provided in a normal automobile may be directly connected to the control device 17 as a sensor. Similarly, 31 is a detecting means 31 for detecting the number of revolutions of the engine 1. For example, if the engine 1 is a spark ignition engine such as a gasoline engine, the number of pulses of the ignition signal generated within a unit time is controlled by the control device. If the count is performed at 17, the rotational speed of the engine 1 is obtained, and the device related to this is the engine rotational speed detection means 31.
[0022]
Although not shown in FIG. 1, even if an event that can be indirectly detected by the above detection means is used as a detection means for directly detecting the event, for example, a lock-up clutch 16 is used. A sensor or the like for directly detecting the intermittent state can be provided as necessary. In the control device of the present invention, control means for intermittently controlling the fuel supply to the engine 1, control means for ON / OFF control of the ignition device, and the like are also required. However, control such as fuel supply cut and fuel supply return performed by these control means is performed by the electronic control unit 17 controlling the normal engine control means 19, so these control means are usually Is included in a part of the engine control means 19.
[0023]
FIG. 2 shows a structure of a one-way clutch 32 provided in association with the starter 7 of the embodiment. The one-way clutch 32 is provided between the output rotating shaft 33 of the starting motor 7 and the pulley 34 also shown in FIG. 1, and the motor 7 rotates the crankshaft 2 via the belt 8. In particular, the motor 7 can be driven to rotate, but the motor 7 is prevented from being driven from the crankshaft 2 side. Therefore, when the starting motor 7 having the one-way clutch 32 as shown in FIG. 2 is used, the motor 7 cannot be used as a generator as described above.
[0024]
In FIG. 2, 35 is a planetary gear type speed reducer, 36 is an inner ring of the one-way clutch 32, 37 is an outer ring, and 38 is a number of cams supported between the inner ring 36 and the outer ring 37 so as to be able to rotate up and down. The inner ring 36 is rotatably supported on the rotating shaft 33 and is driven to rotate by being decelerated from the rotating shaft 33 by the speed reducer 35. The outer ring 37 is attached to the inner end of the rotating shaft 40 supported by the housing 39 of the one-way clutch 32. A pulley 34 is attached to the outer end of the rotating shaft 40.
[0025]
The cam 38 of the one-way clutch 32 stands up when the inner ring 36 is driven with respect to the outer ring 37 when the motor 7 is supplied with electric power and rotates by the starter control means 20 that operates according to a command of the electronic control unit 17. Then, they are sandwiched between the inner ring 36 and the outer ring 37 in a wedge shape to interlock them. Thereby, the rotation of the inner ring 36 decelerated by the reduction gear 35 is transmitted to the outer ring 37 and further transmitted to the crankshaft 2 via the rotating shaft 40 and the pulley 34, the belt 8 and the crank pulley 3, and the engine 1 is started. As a result, when the engine 1 is started and the rotational speed of the crankshaft 2 increases, the outer ring 37 drives the inner ring 36, so that the cam 38 rotates so as to fall and the cam between the outer ring 37 and the inner ring 36 is interposed. The engagement is released and the transmission state between them is cut off.
[0026]
Since the engine automatic stop / restart control apparatus according to the embodiment shown in FIG. 1 has the above-described configuration, the operation of this apparatus is repeatedly executed by the electronic control unit 17 every predetermined short time. This will be described in detail with reference to a control program as shown in the flowchart of FIG. 3 and a diagram as shown in FIG. In addition, although the time chart in the driving | running state is shown by FIG.5 and FIG.6, description is added later about these.
[0027]
While the vehicle equipped with the control device of the embodiment is running, the accelerator pedal depression amount (accelerator opening) by the driver becomes 0, the vehicle enters a deceleration state where the vehicle speed decreases, and the acceleration / deceleration detecting means 23 When the detection signal becomes equal to or less than a predetermined negative value, the electronic control unit 17 detects the deceleration state of the vehicle in step 301 based on the signal. Further, in step 302, when it is detected that the accelerator switch 25, which is a means for detecting the depression amount of the accelerator pedal, is OFF and it is confirmed that the accelerator pedal is not depressed, the routine proceeds to step 303. The control device 17 controls the engine control means 19 to instruct the engine body 1 to cut fuel and prohibit fuel return.
[0028]
At the same time, the control device 17 controls the transmission control means 18 to turn on the lockup clutch 16 (or the control clutch corresponding thereto as described above, etc.) of the automatic transmission 12 so that the fuel is supplied. The crankshaft 2 of the engine 1 whose supply is cut and no longer generates torque is driven reversely by the drive wheels 10 and the axle 11 to continue to rotate. When the deceleration state is not detected at step 301 or when the accelerator pedal is depressed at step 302, the process returns to step 301 and repeats the determination.
[0029]
After performing step 303, it is confirmed again in step 304 that the accelerator switch 25 is OFF (acceleration operation has not been performed), and then the routine proceeds to step 305, where the crank detected by the engine speed detection means 31 is detected. It is determined whether or not the rotational speed of the shaft 2 is equal to or greater than a predetermined rotational speed Nlimit.
[0030]
Here, Nlimit is a predetermined value having the following meaning. In general, a reciprocating engine passes through a rotational speed region called a resonance region (see FIG. 5) by the time when the rotational speed decreases and stops. Large vibrations that are uncomfortable for passengers occur. Nlimit is the maximum number of revolutions in this resonance range and the amount of decrease in engine speed expected during the time delay until the engine speed actually begins to drop after control to stop the engine is added. It is the number of revolutions. When the rotational speed decreases and reaches Nlimit, the vibration generated in the resonance region can be reduced by rapidly passing the following resonance region.
[0031]
If it is determined YES in step 305 (the rotation speed of the crankshaft 2 has not dropped to Nlimit), the process returns to step 304 and repeats the determination. Deceleration progresses in the fuel cut state and the rotational speed of the crankshaft 2 also decreases, and if it is determined NO in step 305 (the rotational speed has reached Nlimit and approached the resonance range), the process proceeds to step 306. It is determined whether or not the brake depression amount detected by the brake depression amount detection means 24 is equal to or greater than a predetermined value. If the driver depresses the brake with a magnitude greater than a predetermined value in order to stop the vehicle, the routine proceeds to step 307 to allow the engine 1 to stop, and the lockup clutch is connected via the transmission control means 18. 16 is released to cut off the linkage between the crankshaft 2 and the axle 11, and the transmission 14 is controlled to the neutral state.
[0032]
In step 308 after enabling the engine 1 to stop rotating, the electronic control unit 17 determines whether or not the engine start condition is satisfied. Various engine starting conditions can be used as the OR condition, such as when the accelerator switch 25 is turned on or when the remaining battery level is below a predetermined value. The starting condition is taken when the amount of brake depression falls below a predetermined value. Accordingly, in step 308, it is determined whether or not the brake depression amount is equal to or less than a predetermined value. If the determination is NO (the brake depression amount is equal to or greater than a predetermined value), the driver has not changed his / her intention to stop even after the lock-up clutch 16 is released and the rotation of the engine 1 can be stopped. Then, the process returns to step 308 again to repeat the determination. Meanwhile, the engine 1 is completely stopped.
[0033]
The continuous stop (parking) can be confirmed, for example, by generating an ON signal by the parking brake operating state detection means 30, so that even if the control device 17 is set to end the control at that stage. Although it may be good, the driver | operator may instruct | indicate re-acceleration in the stage in the middle before stopping, or after stopping temporarily, The restart operation of the engine 1 is needed at that time.
[0034]
In step 304, it is clear that the accelerator switch 25 is ON, that is, when the driver commands the re-acceleration by depressing the accelerator pedal. However, in step 306, the brake depression amount is a predetermined value (in this case, the engine is restarted). If the threshold value S2) is equal to or lower than (NO), it is considered that the driver's intention has shifted from the stop of the automobile to the continuation of driving or reacceleration. Even if the determination in step 308 after releasing the lockup clutch 16 and performing the engine rotation stoppage is YES (for example, the brake depression amount is equal to or less than the predetermined value S2), the vehicle was originally intended to stop. It is probable that the driver's intention changed and the vehicle was accelerated again as described above. Therefore, in the control of the control device 17 of the embodiment, in any of these cases where reacceleration is performed, it is necessary to supply the fuel to the engine 1 again and restart it to increase the rotational speed. Proceed to step 309 to do so.
[0035]
In step 309 which is in preparation for restart and re-acceleration, the control device 17 locks up via the transmission device control means 18 because step 309 may be reached directly from step 304 without going through step 307. The clutch 16 is turned off so that the crankshaft 2 can freely rotate. At the same time, the control of the transmission 14 of the automatic transmission 12 by the transmission control means 18 is also returned to the normal control mode.
[0036]
In the next step 310, a predetermined value Ncrank of the engine speed is set. Ncrank is a threshold value for determining whether or not to operate the starter 7 when re-acceleration is predicted and fuel supply is resumed. Ncrank is a value determined by the warm-up state of the engine 1 detected from the temperature of the coolant or engine oil of the engine 1 or the load state on the engine 1 detected from the operating state of the auxiliary machine or the load state of the generator 4. It is. Accordingly, as shown in the diagram of FIG. 4, parameters such as the engine speed reduction speed and the temperature of the cooling water detected by the cooling water temperature sensor 46 are mapped in advance as shown in the diagram of FIG. ing. Therefore, in the case of FIG. 4, the value of Ncrank is determined by giving the rate of decrease in engine speed and the cooling water temperature at that time.
[0037]
In step 311 of FIG. 3, it is determined whether or not the engine speed at that time is larger than the selected value of Ncrank. When it is not large (NO), the starter 7 is operated in step 312, but when it is large (YES), the starter 7 is not operated. Thereby, the frequency | count of operating the starter 7 can be reduced. Thereafter, in either case, the process proceeds to step 313 to restart the fuel supply. In step 314, in order to determine whether or not the engine has been started, it is determined whether or not the rotational speed has reached a predetermined value within a predetermined time. If it has reached (YES), the process proceeds to step 315. If the starter 7 is being driven, it is stopped and then the process returns to the first step 301. If not (NO), the process returns to step 312. The restart operation by driving the starter 7 is repeated.
[0038]
Such an operation is shown over time in the time chart of FIG. 5 or FIG. 6 (the horizontal axis is the elapsed time). The solid line in FIG. 5 shows a case where the re-acceleration request by the driver is slow and the rotation of the engine 1 is completely stopped during that time. When the rotational speed passes Nlimit shortly before the engine 1 automatically stops, the transmission 14 is set to the neutral state in order to avoid resonance, and the lockup clutch 16 is turned off. When the brake depression amount is less than or equal to the predetermined value, the electronic control unit 17 predicts that the driver will request re-acceleration unless the parking brake operation state detection means 30 detects a signal, The supply is resumed and the starter 7 is driven. In this case, since the engine 1 is completely stopped and the rotational speed is 0 which is equal to or less than Ncrank, restarting is always performed by the starter 7 and the rotational speed of the engine is increased to Nlimit or higher. If the accelerator opening becomes large as expected and the re-acceleration request is ensured, the engine 1 has already been started, so the amount of fuel is increased and the engine speed rapidly rises without any delay.
[0039]
In the time chart of FIG. 5, what is indicated by a broken line is a case in which re-acceleration is predicted due to a decrease in the brake depression amount of the driver before the engine is completely stopped. In the case shown in the figure, the engine speed has decreased to just before it becomes zero and is equal to or less than the value of Ncrank. Therefore, the crankshaft 2 is still rotating but is restarted by the starter 7.
[0040]
Unlike these cases, in the time chart of FIG. 6, the brake depression amount is 0 and does not change. This shows a case where the restart control is started after clearly confirming the driver's reacceleration request. In FIG. 6, the solid line shows a case where the engine 1 at that time is higher than Ncrank, so that the starter 7 is not used and the restart is performed simply by restarting the fuel supply. In this case, since the engine speed is higher than Nlimit and the lockup clutch 16 is still ON, the lockup clutch 16 is simultaneously turned OFF when the fuel supply is resumed. Since the starter 7 is not used, unnecessary power is not consumed, so that waste of fuel can be avoided.
[0041]
In FIG. 6, what is indicated by a broken line is that the fuel supply is actually supplied even when the electronic control unit 17 starts the restart control because the accelerator opening indicating the driver's reacceleration request is delayed. This is a case where the engine speed is reduced to Ncrank or less during a time delay until the lockup clutch 16 is turned off while being restarted. Even in such a case, the starter 7 should be driven to ensure restart.
[0042]
In this way, the restart of the engine 1 is completed quickly, and the number of revolutions can be increased to meet the demand for rapid reacceleration at any time. In addition, since the one-way clutch 32 having the structure illustrated in FIG. 2 is provided in the starter 7 of the embodiment, the restart operation is possible even when the crankshaft 2 is rotating. Further, there is a difference in whether or not the starter 7 is used when restarting depending on the high engine speed. When the value rises above a certain value, the one-way clutch 32 becomes idle, so there is no possibility that the starter 7 is rotated by the crankshaft at a high speed and damaged. Further, in the present embodiment, during the automatic stop of the engine 1, the electric negative pressure pump 43 and the electric hydraulic pump 42 are driven by the control means 17, so that a predetermined negative pressure is ensured in the brake system 45 and the hydraulic control mechanism A predetermined hydraulic pressure can be ensured in 44, and each operation can be performed appropriately.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an automatic stop / restart control apparatus according to an embodiment of the present invention;
FIG. 2 is a cross-sectional view illustrating the structure of a one-way clutch or the like that can be used in the device of the present invention.
FIG. 3 is a flowchart illustrating a control program of the control device according to the embodiment.
FIG. 4 is a diagram illustrating the contents of a map used when setting a predetermined value for determining whether or not to use a starting motor.
FIG. 5 is a time chart illustrating one operating state of the example device.
FIG. 6 is a time chart illustrating another operation state of the embodiment device;
[Explanation of symbols]
1. Engine body
2 ... Crankshaft
4 ... Generator
5 ... Battery
6… Compressor for air conditioner
7 ... Starting motor (starter, torque application means)
8 ... Belt
9 ... Power transmission mechanism that can always drive the crankshaft
10 ... Drive wheel
11 ... Axle
12 ... Automatic transmission
13 ... Torque converter
14 ... Transmission
16 ... Lock-up clutch
17 ... Electronic control device (engine automatic stop / restart control means)
18 ... Transmission device control means
19 ... Engine control means (including fuel injection control means)
20 ... Starter control means
23. Acceleration / deceleration detection means
24. Brake depression amount detection means
25 ... Detection means of accelerator pedal depression amount (accelerator switch)
30 ... Parking brake operating state detecting means
31 ... Engine rotational speed detection means
32 ... One-way clutch
35 ... Planetary gear type speed reducer
41 ... Battery remaining amount detecting means
42 ... Electric hydraulic pump
43 ... Electric negative pressure pump
44. Hydraulic control mechanism
45 ... Brake system
46. Warm-up state detection means

Claims (4)

An engine automatic stop / restart control means for automatically stopping the engine when a predetermined automatic stop condition is satisfied, and automatically restarting when the predetermined restart condition is satisfied;
Torque applying means for applying torque to the engine;
Fuel injection control means for controlling the fuel injected into the engine;
Engine speed detecting means for detecting the engine speed;
When the engine speed detected by the engine speed detector is smaller than a predetermined speed when an automatic stop condition is satisfied during deceleration of the vehicle traveling by the engine and a restart condition is subsequently satisfied the rotation of the engine while applying a torque to the engine by the torque applying means, to said by the fuel injection control means to resume the fuel injection to the engine have rows restart of the engine, within a predetermined time If the number has reached a predetermined value, the driving of the torque applying means is stopped, and if the engine speed has not reached the predetermined value within a predetermined time, a restart operation by the torque applying means is performed. And repeat
When the engine speed detected by the engine speed detection means is larger than a predetermined speed, the engine is restarted only by restarting fuel injection to the engine by the fuel injection control means. An engine control device configured as described above. In the engine control device according to claim 1,
When the detected engine speed is smaller than the predetermined engine speed, the torque applying means applies torque to the engine until the engine engine speed reaches the predetermined engine speed. An engine control device characterized by comprising: In the engine control device according to claim 1 or 2,
The engine control apparatus, wherein the torque applying means is connected to a crankshaft of the engine via a one-way clutch. The engine control device according to any one of claims 1 to 3,
The predetermined engine speed is set from at least a warm-up state of the engine and a load state of the engine.

Images