JP2003201882A - Engine control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate reduction of cooling function by the stop control of an engine. <P>SOLUTION: This device is provided with an automatic stop or reset control to automatically changes the state of an engine to stop or driving based on the required stop conditions or reset conditions. The engine control device which cools the engine by a cooling device driven by the power of the engine is equipped with a traveling state judging means (step S20) which determines whether the vehicle travels continuously for more than the required time at the speed higher than the required level and automatic stop prohibition means (steps S21, 22, 5) which prohibit automatic stop control of the engine when the stop conditions are satisfied after the continuous high-speed traveling is confirmed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle engine control device capable of performing engine stop control based on a predetermined condition.

[0002]

2. Description of the Related Art In vehicles equipped with an engine,
The fuel is burned inside the engine to generate heat energy, and the heat energy is converted into mechanical energy (power) to drive the vehicle. On the other hand, in recent years, in order to save fuel, reduce emissions, and reduce noise, the engine is automatically stopped based on a predetermined stop condition, and the engine is stopped from a stopped state based on a predetermined return condition. A control device capable of returning to an operating state has been proposed.

An example of such a control device is described in Patent Document 1 below. The control device described in Patent Document 1 is intended for a vehicle equipped with an automatic transmission, and a foot brake is used as a condition for automatically stopping the engine in a state in which a traveling position of the automatic transmission is selected. Examples include ON, zero vehicle speed, parking brake operation, engine stop manual switch operation, and the like. On the other hand, examples of conditions for restarting the engine include releasing the parking brake, closing the entry / exit door, and releasing the engine stop manual switch.

With the above structure, the shift lever is kept in the traveling position, and only by operating the engine stop switch or the like, the engine is automatically stopped temporarily or started to start the vehicle. It is said that the fuel consumption can be simplified and wasteful fuel consumption can be suppressed.

On the other hand, although the engine is a device for converting heat energy into mechanical energy, it is not possible to convert all the heat energy into mechanical energy, and the temperature rise of the engine parts is inevitably caused. Therefore, it is known to provide a cooling device in order to suppress the temperature rise of the engine. And this cooling device is configured to be driven by the power of the engine.

[0006]

[Patent Document 1] Japanese Unexamined Patent Publication No. 9-310629 (claims, paragraphs 0004 to 0008,
(Fig. 2)

[0007]

By the way, when the vehicle is stopped at a high speed for a predetermined time or more and then stopped, and the engine is stopped due to the stop condition being satisfied, the engine is driven by the driving force of the engine. The cooling system will also be stopped. As a result, it may be difficult to suppress the temperature rise of the engine.

As described above, if the engine stop control is uniformly performed based on the predetermined stop condition, the cooling function of the cooling device may be deteriorated, and there is still room for improvement.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an engine control device for a vehicle which can suppress deterioration of cooling performance of a cooling device due to engine stop control.

[0010]

In order to achieve the above object, the invention of claim 1 automatically changes the engine between a stopped state and an operating state based on a predetermined stop condition or return condition. In an engine control device of a vehicle capable of performing automatic stop / return control to cool the engine by a cooling device driven by the power of the engine, a vehicle speed equal to or higher than a predetermined value for a predetermined time. In the case where the stop condition is satisfied after it is determined that the continuous high-speed traveling in which the vehicle continuously travels as described above is determined, and the continuous high-speed traveling is determined, An automatic stop prohibition unit for prohibiting the automatic stop control of the engine is provided.

According to the first aspect of the present invention, the engine stop control is prohibited when the stop condition is satisfied after it is determined that the vehicle has been continuously driven at high speed. Therefore, deterioration of the function of the cooling device is suppressed.

According to a second aspect of the present invention, it is possible to perform automatic stop / return control for automatically changing the engine between a stopped state and an operating state based on a predetermined stop condition or return condition. In the engine control device of the vehicle capable of cooling the engine by the cooling device driven by the power of, is the vehicle continuously traveling at a vehicle speed equal to or higher than a predetermined value for a predetermined time or longer. A traveling state determining means for determining whether or not the stop condition is satisfied after it is determined that the continuous high speed traveling is performed, and until a predetermined time elapses after the stop condition is satisfied. Is provided with an automatic stop holding means for holding the automatic stop control of the engine.

According to the second aspect of the present invention, when the stop condition is satisfied after it is determined that the vehicle has been continuously driven at high speed, a predetermined time period elapses after the stop condition is satisfied. , The engine stop control is suspended. Therefore, deterioration of the function of the cooling device is suppressed.

According to a third aspect of the invention, an engine control of a vehicle capable of performing automatic stop / return control for automatically changing the engine between a stopped state and an operating state based on a predetermined stop condition or return condition. In the device, a vehicle is continuously traveling at a high speed, and a running state determining means for determining whether or not the vehicle suddenly stops, and based on the determination result of the running state determining means, the engine water temperature is equal to or higher than a predetermined value. There is an engine water temperature judgment means for estimating that there is a possibility that it will rise above a predetermined value, and this engine water temperature judgment means means that the engine water temperature is above a predetermined value or can rise above a predetermined value. If it is presumed that there is a possibility that there is a possibility that there is a possibility that the engine will be stopped, the control that prohibits the stop control of the engine or the stop condition is satisfied Until the elapse of the Luo predetermined time, and is characterized in that it comprises a stop holding means for selecting either the control to suspend the stop control the engine.

According to the third aspect of the present invention, it is estimated that the engine water temperature is higher than or equal to a predetermined value or may rise higher than the predetermined value, based on the determination result of the running state. Then, if it is estimated that the engine water temperature is equal to or higher than a predetermined value or may rise to a predetermined value or higher, control that prohibits engine stop control even if the stop condition is satisfied, or One of the controls for suspending the engine stop control is selected until the predetermined time elapses after the stop condition is satisfied.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the running state determination means is such that the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher, and thereafter, the predetermined state. When the vehicle speed becomes zero within the time, it is further provided with a function of judging that the vehicle has suddenly stopped.

According to the invention of claim 4, in addition to the same effect as that of the invention of claim 3, the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher and for a predetermined time thereafter. When the vehicle speed becomes zero, it is determined that the vehicle has suddenly stopped.

According to a fifth aspect of the present invention, in addition to the configuration of the third aspect, the running condition determination means is such that the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher, and thereafter, a negative brake is applied. Is further provided with a function of determining that the vehicle has suddenly stopped when the vehicle has stopped at an acceleration of a predetermined value or more.

According to the invention of claim 5, in addition to the same effect as that of the invention of claim 3, the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher, and thereafter, the negative brake is applied. When the vehicle is stopped with the acceleration being equal to or higher than the predetermined value, it is determined that the vehicle has stopped suddenly.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described more specifically with reference to the drawings. FIG. 2 is a block diagram showing the system configuration of a vehicle to which the present invention is applied. An internal combustion engine such as a gasoline engine, a diesel engine, or an LPG engine is used as the engine 1 that is the power source of the vehicle. Further, a starter 1A as a starting device for starting the engine 1 is provided. This starter 1A
A known structure such as a magnetic shift type or a reduction gear type is used as the material. Further, an electronic throttle valve 2 is provided in the intake pipe of the engine 1, and the opening of the electronic throttle valve 2 is electrically controlled.

A torque converter 3, an oil pump 4, and a gear transmission mechanism 5 are arranged in one transmission path of the torque output from the engine 1. Specifically, the torque converter 3 is arranged between the engine 1 and the gear transmission mechanism 5, and the oil pump 4 is arranged between the torque converter 3 and the gear transmission mechanism 5. Further, a motor / generator 7 is arranged in the other transmission path of the torque output from the engine 1 via the drive device 6.

First, the configuration of one torque transmission path will be specifically described. An automatic transmission fluid (hereinafter, abbreviated as ATF or oil) as working oil is enclosed in a casing 8 that houses the torque converter 3, the oil pump 4, and the gear transmission mechanism 5. Torque converter 3
Includes a pump impeller 9, a turbine runner 10, and a stator 3A. The stator 3A is for amplifying the torque transmitted from the pump impeller 9 to the turbine runner 10. Then, the power of the engine 1 is transmitted to the pump impeller 9 and the pump impeller 9
Is transmitted to the turbine runner 10 by the ATF. The torque converter 3
Includes a lockup clutch 3B that mechanically connects the pump impeller 9 and the turbine runner 10.

Further, the power of the engine 1 is transmitted to the oil pump 4 via the pump impeller 9, and the oil pump 4 is driven to generate a source pressure of an oil passage of a hydraulic control device (described later). Further, the gear transmission mechanism 5 includes an input shaft 11, a planetary gear 12, a forward clutch C1 and a reverse clutch C.
Various types of friction engagement devices including 2 and the output shaft 13 are provided. The forward clutch C1 and the reverse clutch C2
The engagement / release of the piston is controlled by a piston operated by hydraulic pressure.

The input shaft 11 is the turbine runner 10
And the output shaft 13 is connected to the wheel 14.
The gear speed change mechanism 5 is configured to be able to set, for example, five forward gears and one reverse gear (that is, a gear ratio). The forward clutch C1 is engaged when the forward speed is set, and the reverse clutch C2 is engaged when the reverse speed is set.

Further, in this embodiment, the shift lever 15
It is possible to select various shift positions by manual operation of. For example, P (parking) position, R (reverse) position, N (neutral) position, D (drive) position, 4 position, 3 position, 2 position, and L (low) position can be selected. . here,
The D position, 4 position, 3 position, 2 position, L position, and R position are running positions.

Then, D position, 4 position, 3
When the position 2 or the position 2 is selected, it is possible to shift between a plurality of shift stages. On the other hand, when the L position or the R position is selected, it is fixed to a single gear. A lock mechanism 13A is provided inside the casing 8 so that the rotation of the output shaft 13 is prevented by the lock mechanism 13A when the P position is selected.

Further, the hydraulic control device 16 supplies the hydraulic pressure to the piston for operating the setting or switching of the shift speed in the gear shift mechanism 5, the engagement / release of the lockup clutch 3B and the slip control, and the friction engagement device. The line pressure of the hydraulic circuit and the engagement pressure of the friction engagement device are controlled. The hydraulic control device 16 is electrically controlled, and has first to third shift solenoid valves S1 to S for executing the gear shift of the gear shift mechanism 5.
3 and a fourth solenoid valve S4 for controlling the engine braking state.

Further, the hydraulic control device 16 includes a linear solenoid valve SLT for controlling the line pressure of the hydraulic circuit.
And a linear solenoid valve SLN for controlling the accumulator back pressure at the time of gear shifting of the gear shifting mechanism 5.
And a linear solenoid valve SLU for controlling the engagement pressure of the lockup clutch 3B and a predetermined friction engagement device.

FIG. 3 is a schematic view showing a part of a hydraulic circuit corresponding to the forward clutch C1. A primary regulator valve 17 is provided in the oil passage connected to the oil pump 4. This primary regulator valve 1
7 is the line pressure P that is the original pressure generated by the oil pump 4.
It is for adjusting the pressure to L. This primary regulator valve 17 is controlled by a linear solenoid valve SLT. Then, the line pressure PL regulated by the primary regulator valve 17 is guided to the input port of the manual valve 18. The manual valve 18 is mechanically connected to the shift lever 15. When the forward position, for example, the D position or the second position is selected by the shift lever 15, the input port and the output port of the manual valve 18 communicate with each other, and the line pressure PL changes the forward clutch C1.
Is supplied to.

A large orifice 19 and a switching valve 20 are arranged in series in an oil passage 75 between the manual valve 18 and the forward clutch C1. The opening / closing of the switching valve 20 is controlled by the solenoid 21. This switching valve 20
Is the line pressure PL supplied through the large orifice 19.
Is selectively supplied to or cut off from the forward clutch C1. The solenoid 21 is controlled by the electronic control unit 47.

Further, the switching valve 20 is bypassed, and
An oil passage 76 is provided, one end of which is connected between the forward clutch C1 and the switching valve 20, and the other end of which is connected between the large orifice 19 and the switching valve 20. In the oil passage 76, the check ball 22 and the small orifice 23 are arranged in parallel with each other. The distribution area of the small orifice 23 is set smaller than the distribution area of the large orifice 19. Then, when the switching valve 20 is closed, the oil that has passed through the large orifice 19 is further reduced to the small orifice 2
The forward clutch C1 is reached via route 3. The check ball 22 has a function of reducing the amount of oil supplied to the forward clutch C1 via the oil passage 76 when the forward clutch C1 is engaged. Further, the check ball 22 has a function of enlarging the oil circulation area and promoting the discharge of the oil supplied to the forward clutch C1 when the forward clutch C1 is released.

On the other hand, an accumulator 25 is arranged in the oil passage 75 between the switching valve 20 and the forward clutch C1 via the orifice 24. This accumulator 25
Includes a piston 26 and a spring 27.
When the shift lever 15 is switched from the N position to the D position to engage the forward clutch C1, the accumulator 25 and the orifice 24 supply the hydraulic pressure supplied to the forward clutch C1 for a predetermined time to the spring 27 and the accumulator. This is for controlling to a predetermined hydraulic pressure characteristic determined by the back pressure (specifically, a characteristic that gradually increases).

Therefore, the shift lever 15 is switched from the N position to the D position and the forward clutch C
When 1 is engaged, the shock generated immediately before the engagement of the forward clutch C1 is completed can be reduced. The hydraulic circuit corresponding to the reverse clutch C2 is also shown in FIG.
It can be configured in the same manner as the hydraulic circuit of.

FIG. 4 is an explanatory view showing the structure of the other torque transmission path of the engine 1. The drive device 6 is the speed reducer 2
8 and the speed reducer 28 is connected to the engine 1 and the motor / generator 7. As the motor generator 7, for example, an AC synchronous type is applied. The motor / generator 7 is a permanent magnet (not shown).
And a stator (not shown) around which a coil (not shown) is wound. Then, when a three-phase alternating current is passed through the three-phase winding of the coil, a rotating magnetic field is generated, and torque is generated by controlling the rotating magnetic field according to the rotating position and the rotating speed of the rotor. The torque generated by the motor / generator 7 is almost proportional to the magnitude of the current, and the rotation speed of the motor / generator 7 is controlled by the frequency of the alternating current.

The speed reducer 28 includes a ring gear 29 and a sun gear 30 arranged concentrically, and the ring gear 29.
And a plurality of pinion gears 31 meshed with the sun gear 30. The plurality of pinion gears 31 are held by a carrier 32, and a rotary shaft 33 is connected to the carrier 32. Further, a rotary shaft 35 is provided concentrically with the crankshaft 34 of the engine 1, and a clutch 36 that connects and disconnects the rotary shaft 35 and the crankshaft 34 is provided. And the rotating shaft 3
A chain 37 is provided to mutually transmit torque between the gear 5 and the rotary shaft 33. An auxiliary machine 39 is connected to the rotary shaft 33 via a chain 38. An example of the auxiliary device 39 is a compressor for an air conditioner.

The motor / generator 7 has an output shaft 4
0, and the sun gear 30 is attached to the output shaft 40. The housing 41 of the drive device 6 is provided with a brake 42 that stops the rotation of the ring gear 29. Further, a one-way clutch 43 is arranged around the output shaft 40, an inner ring of the one-way clutch 43 is connected to the output shaft 40, and an outer ring of the one-way clutch 43 is connected to the ring gear 29. By the speed reducer 28 having the above-described configuration, torque transmission or speed reduction is performed between the engine 1 and the motor / generator 7. And
The one-way clutch 43 is configured to be engaged when the torque output from the engine 1 is transmitted to the motor / generator 7.

The motor / generator 7 functions as a starting device for starting the engine 1, as a generator (alternator) for generating power by the power of the engine 1, and drives the auxiliary machine 39 when the engine 1 is stopped. It has both functions.

When the motor / generator 7 is made to function as a starter, the clutch 36 and the brake 42 are engaged and the one-way clutch 43 is released.
When the motor / generator 7 is made to function as an alternator, the clutch 36 and the one-way clutch 4 are used.
3 is engaged and the brake 42 is released. Further, when the auxiliary machine 39 is driven by the motor / generator 7, the brake 42 is engaged and the clutch 36 and the one-way clutch 43 are released.

A battery 45 is connected to the motor / generator 7 through an inverter 44, and the motor / generator 7 and the inverter 44 and the battery 4 are connected.
A controller 46 is connected to 5. And
It is possible to input the power output from the engine 1 to the motor / generator 7 to generate electric power, and to charge the battery 45 with the electric energy via the inverter 44.

The power output from the motor / generator 7 can be transmitted to the engine 1 or the auxiliary machine 39. Further, when the motor / generator 7 is made to function as an electric motor, the DC voltage from the battery 45 is converted into an AC voltage and supplied to the motor / generator 7. When the motor / generator 7 is made to function as a generator, the induction voltage generated by the rotation of the rotor is converted into a DC voltage by the inverter 44 and the battery 45 is charged.

The controller 46 has a function of detecting or controlling a current value supplied from the battery 45 to the motor generator 7, or a current value generated by the motor generator 7. Further, the controller 46 has a function of controlling the rotation speed of the motor / generator 7, and a state of charge (SOC: state of cha) of the battery 45.
rge) is detected and controlled.

FIG. 5 is a block diagram showing a control circuit of a vehicle to which the present invention is applied. Electronic control unit (ECU)
The reference numeral 47 includes a central processing unit (CPU), a storage device (RAM, ROM), and a microcomputer mainly including an input / output interface.

The electronic control unit 47 has a signal from an engine speed sensor 48, a signal from an engine water temperature sensor 49 for detecting the temperature of a cooling medium of a water cooling type cooling device (described later), that is, a signal from an engine water temperature sensor 49, and a signal from the engine 1. A signal from the ignition switch 50, a signal from the controller 46, a signal from the air conditioner switch 51, and a signal from the input shaft 1 that form a part of the starting mechanism.
The signal of the input shaft rotation speed sensor 52 for detecting the rotation speed of 1
A signal from an output shaft rotation speed sensor (vehicle speed sensor) 53 that detects the rotation speed of the output shaft 13, a signal from an oil temperature sensor 54 that detects the temperature of the ATF, and a signal from a shift position sensor 55 that detects the operating position of the shift lever 15. Has been entered.

Further, the electronic control unit 47 has a signal of a parking brake switch 56 for detecting the driver's intention to stop, a signal of a foot brake switch 57 for detecting the driver's intention to decelerate or brake, and an exhaust pipe (not shown). ), A signal from a catalyst temperature sensor 58, a signal from an accelerator opening sensor 60 indicating the amount of depression of an accelerator pedal (acceleration request device) 59, and a throttle opening detecting the opening of an electronic throttle valve 2 of the engine 1. The signal of the frequency sensor 61 or the like is input.

Further, the electronic control unit 47 is provided with a signal from a resolver 62 for detecting the number of rotations and a rotation angle of the motor / generator 7, a signal from an acceleration sensor 65 for detecting positive and negative accelerations of the vehicle, and a foot shown in FIG. Brake pedal 6
The signal of the brake pedal force sensor 64 for detecting the pedal force of No. 3 is input. The brake pedal force sensor 64 is used for the wheel 1
This is for indirectly detecting the hydraulic pressure (in other words, the braking force) acting on the No. 4 Hall cylinder (not shown) based on the pedaling force applied to the foot brake pedal 63.

Further, the electronic control unit 47 is provided with a state (hereinafter referred to as eco-run) in which automatic stop / return control for automatically changing the engine 1 between the operating state and the stopped state can be performed based on a predetermined condition. (Abbreviated as control status)
The signal of the main switch 68 for releasing is input. The eco-run control state is set by turning on the main switch 68, and the eco-run control state is released by turning off the main switch 68. This main switch 68
Is provided in a vehicle compartment, for example, near an instrument panel or a console box, and is operated by an occupant of the vehicle.

From the electronic control unit 47, the starter 1
A control signal for A, a signal for controlling the ignition device 65 of the engine 1, a signal for controlling the fuel injection device 66 of the engine 1, a signal for controlling the controller 46, a signal for controlling the clutch 36 and the brake 42 of the drive device 6, and a hydraulic pressure. The electronic throttle valve is based on a signal for controlling the control device 16, a control signal to an indicator 67 for outputting an automatic stop / automatic return state of the engine 1 by a lamp or a buzzer, a map corresponding to the accelerator opening, or other conditions. A control signal of the actuator 68 for controlling the opening degree of 2 is output.

Further, as shown in FIG. 2, the engine 1 is equipped with a water cooling type cooling device 77. This water cooling type cooling device 7
Reference numeral 7 has a function of cooling the engine 1 and the ATF. The water cooling type cooling device 77 includes a water pump (not shown) driven by the crankshaft 34, a water jacket (not shown) formed inside the engine body, a water pump and a radiator connected to the water jacket. (Not shown). The cooling water heated by the water jacket is transported to the radiator to be cooled, and the cooled water is transported again to the inside of the engine by the water pump.

Further, the valve body (not shown) of the hydraulic control device 16 and the radiator are connected by an oil cooler tube (not shown). This oil cooler tube is for transporting ATF. Then, on the side of the automatic transmission A1, the torque converter 3
The ATF that has been heated due to the heat of the oil is transported inside the radiator by the oil cooler tube,
After being cooled by the ATF cooler, it is returned to the automatic transmission A1 side.

The control contents of the vehicle will be briefly described. When the ignition switch 50 is set to the start position by operating an ignition key (not shown), the engine 1 is started by the power of the starter 1A or the motor / generator 7. When the operation force applied to the ignition key is released, the ignition switch 50 automatically returns to the ON position. While the vehicle is running,
Based on the shift map (shift map) stored in the electronic control unit 47, the gear shift mechanism 5 and the hydraulic control unit 1
The automatic transmission A1 having 6 is controlled, and the automatic transmission A1
The gear ratio of is controlled. Further, the lockup clutch 3B is controlled based on the lockup clutch control map stored in the electronic control unit 47.

On the other hand, the battery 45 is controlled so that the charge amount falls within a predetermined range, and when the charge amount becomes small, the engine output is increased and a part of the motor is
Control is performed to charge the battery 45 with the electric energy transmitted to the generator 7 to generate electric power and generate the generated electric energy.

Further, when the main switch 68 is turned on while the engine 1 is operating, the engine is operated based on conditions other than the signal of the ignition switch 50, specifically, various signals input to the electronic control unit 47. A stop control for automatically switching the engine 1 from the operating state to the stopped state and a return control for automatically returning the engine 1 from the stopped state to the operating state are enabled. Even in the case of this return control, the starter 1A or the motor / generator 7
The engine 1 is started by the power of.

The automatic stop / return control of the engine 1 is as follows.
A signal from the vehicle speed sensor 53, a signal from the foot brake switch 57, a signal from the brake pedal force sensor 64, a signal from the shift position sensor 55, a signal from the accelerator opening sensor 60,
A signal indicating the charge amount of the battery 45, a signal from the engine water temperature sensor 49, a signal from the acceleration sensor 65, and an oil temperature sensor 54.
It is performed based on the signal of.

More specifically, the shift lever 15 is set to N
The automatic stop control / return control of the engine 1 is performed while being operated to the position or the D position. The stop condition for automatically stopping the engine 1 is, for example, that the vehicle speed is zero, the foot brake switch 57 is turned on, the accelerator pedal 15 is turned off, and the state of charge of the battery 45 is a predetermined value or more. It will be established when it becomes. Further, in this embodiment, the engine 1 is based on the state of the vehicle speed related amount related to the vehicle speed.
It is possible to change the contents of the automatic stop / return control of. The return condition for returning the engine 1 from the automatic stop state to the operating state is satisfied, for example, when at least one of the above conditions is lacking.

Now, the state of the system when the automatic stop condition of the engine 1 is satisfied will be described with reference to the time chart of FIG. When the foot brake switch 57 is turned on at time t1 and the automatic stop determination is established, the timing TSTOP from the time when the stop determination is established until the automatic stop of the engine 1 is output by the electronic control unit 47.
Is set as a timer. Then, at time t2 when the timing TSTOP has elapsed, the engine speed NE is gradually decreased from time t3 when the electronic control unit 47 outputs a command to stop the engine 1. Also, the engine speed N
In parallel with the decrease of E, the rotation speed of the oil pump 4 also decreases,
After time t4, which is later than time t3, the forward clutch C1
The hydraulic pressure that acts on is drastically reduced.

On the other hand, during the automatic stop control of the engine 1, if the return condition is satisfied by depressing the accelerator pedal 59 or the like, unless the forward clutch C1 is promptly engaged, the engine 1 is in a rising state. The forward clutch C1 is engaged with, the engagement shock of the forward clutch C1
Also, the durability of the forward clutch C1 may be deteriorated.

That is, when the shift lever 15 is set to the N position during the operation of the engine 1, the line pressure PL acts even on the input port of the manual valve 18, while the engine is set at the D position. When the automatic stop control of 1 is performed, the oil pump 4
Is stopped, the time taken for the hydraulic pressure to reach the forward clutch C1 during automatic return of the engine 1 is
This is because it requires a longer time than in the case of manual shift.

Therefore, in this embodiment, when the return judgment of the engine 1 is established, in order to raise the hydraulic pressure supplied to the forward clutch C1 to a predetermined value early, the first apply control as described below is performed. Alternatively, the startability of the vehicle is improved by performing boost control.

Here, the first apply control will be mainly described, and the boost control will be described later.
First, when the return condition of the engine 1 is satisfied and the automatic return command of the engine 1 is output, the engine 1 is restarted,
At the same time, the rotation of the oil pump 4 is started. The line pressure PL regulated by the primary regulator valve 17 is passed through the manual valve 18 to the forward clutch C.
1 is supplied. Here, when the electronic control unit 47 outputs the signal of the first apply control and the switching valve 20 is opened, the line pressure PL passing through the manual valve 18 passes through the large orifice 19 and then advances as it is. It is supplied to the clutch C1.

When a predetermined time elapses after the forward clutch C1 is started to be engaged and the switching valve 20 is closed by a control signal from the electronic control unit 47, the large orifice 1
The line pressure PL passing through 9 is slowly supplied to the forward clutch C1 via the small orifice 23. Further, at this stage, since the hydraulic pressure supplied to the forward clutch C1 is considerably high, the hydraulic pressure in the oil passage 75 connected to the forward clutch C1 causes the piston 26 to move upward in FIG. Moving. As a result, the hydraulic pressure supplied to the forward clutch C1 is controlled to slowly increase while the piston 26 is moving, so that the forward clutch C1 can be engaged very smoothly.

FIG. 8 is a time chart showing the state of the system accompanying the return control of the engine 1. Among the characteristics indicating the hydraulic pressure of the forward clutch C1, the solid line shows the case where the first apply control is performed, and the broken line shows the case where the first apply control is not performed. The case where the first apply control is not performed means the case where the engagement hydraulic pressure of the forward clutch C1 is always supplied via the small orifice 23.

The time TFAST shows the execution time of the first apply control. This time TFAST
Qualitatively corresponds to the time when the piston (not shown) that operates the forward clutch C1 fills up the so-called clutch pack, and the time slightly before the engine speed NE reaches the predetermined idle speed. It corresponds. In addition,
Tc and Tc ′ correspond to the time when the clutch pack of the forward clutch C1 is packed, and Tac and Tac ′ correspond to the time when the accumulator 25 is functioning.

Here, when the fast apply control is not performed, the hydraulic pressure via the manual valve 18 passes through the small orifice 23 and the forward clutch C1.
Is supplied to. Therefore, it takes a long time T until the clutch pack of the piston of the forward clutch C1 is packed.
After c ′ has passed and the characteristic shown by the broken line is passed, the forward clutch C1 engagement is completed at time t4. On the other hand, in this embodiment, the first apply control is performed during the time TFAST after the return determination of the engine 1 is established at the time t1 and the return instruction of the engine 1 is output at the time t2. , The clutch pack can be packed in a time Tc shorter than the time Tc '. Therefore, the engagement of the forward clutch C1 can be completed at time t3, which is earlier than time t4, and can be completed with a small shock.

By the way, the start timing Ts of the first apply control is the engine rotation speed (in other words,
It is set at the time when the rotational speed NE of the oil pump 4 becomes larger than a predetermined value NE1. As described above, the reason why the first apply control is not started at the same time as the engine restart command Tcom is that the time T1 from the state where the rotation speed of the engine 1 is zero to the state where it is slightly raised varies depending on the traveling environment. This is because there is a possibility.

That is, when the first apply control is started simultaneously with the restart command Tcom of the engine 1,
Under the influence of the variation in the time T1, the forward clutch C1 may start to be engaged while the first apply control is being executed, which may cause a shock. Therefore, by avoiding the time immediately after the restart of the engine 1 in which the variation of the time T1 becomes large and making the time Ts at which the engine speed NE starts to slightly increase at the start timing of the first apply control, regardless of the change of the running environment. The engagement hydraulic pressure of the forward clutch C1 can be supplied in a state where the variation in the time T1 is small.

The start timing of this first apply control can be set according to other conditions. That is, when the return command for the engine 1 is output again immediately after the automatic stop command for the engine 1 is output, the first apply control is started before the hydraulic pressure acting on the forward clutch C1 is sufficiently drained. As a result, the hydraulic pressure of the forward clutch C1 may suddenly increase and an engagement shock may occur.

Therefore, as shown in FIG. 7, the forward clutch C is started from the time when the foot brake switch 57 is turned on.
It is possible to set an estimated time Toff until the hydraulic pressure of 1 becomes zero with a timer so that the first apply control is not performed until the time Toff elapses. Note that instead of the time Toff, the hydraulic pressure drop of the forward clutch C1 may be estimated based on the engine speed NE dropping to a predetermined value, and the timing for starting the first apply control may be set based on the estimation result. It is possible.

Next, the duration TFAST of the first apply control will be described. ATF, which is the hydraulic fluid of the automatic transmission A1, has a characteristic that the viscosity changes depending on its temperature. Since the viscosity of the oil is high at low temperature (for example, 20 ° C. or lower), even if the first apply control is performed for the same time, the oil will be applied to the forward clutch C1 at about room temperature (for example, 20 ° C. to 80 ° C.). Not supplied. Therefore, it is necessary to perform the first apply control at a low temperature for a longer time than at a normal temperature.

On the other hand, when the temperature is high (for example, 100 ° C. or higher), the viscosity of the oil is much lower than that at the normal temperature, and the amount of leakage from each seal portion of the valve body of the hydraulic control device 16 is large. Even if the first apply control is performed for the same time, the amount of oil supplied to the forward clutch C1 tends to decrease. Therefore, it is possible to store a map as shown in FIG. 9 in advance in the electronic control unit 47 and set the time TFAST based on this map. In this way, by setting the time TFAST, even if the viscosity varies due to the difference in the ATF oil temperature, the influence of the viscosity variation on the first apply control is suppressed, and the forward clutch C1 is engaged. Shock can be avoided.

Next, the boost control described above will be described. This pressure increase control is to increase the pressure adjustment value of the primary regulator valve 17 by the function of the linear solenoid valve SLT to increase the line pressure PL. The start timing and duration of this boost control may be the same as or different from those in the first apply control. Then, at the time of automatic return of the engine 1, it is possible to adopt at least one of the above-described first apply control or boost control.

Next, one control example of the present invention will be described with reference to the flowchart of FIG. The control example of FIG. 1 distinguishes a sudden stop of a vehicle from continuous high-speed traveling from a stop of other vehicles, and makes the control content of the engine 1 different according to each stop state. First, the detection signals of various sensors and switches are processed by the electronic control unit 47 (step 1), and it is determined whether or not a precondition for performing stop control of the engine 1 is satisfied (step 2). Here, as prerequisites, the functions of various sensors and switches are normal, the accelerator pedal 59 is not depressed (is off), the engine water temperature is equal to or higher than a predetermined value, and the ATF temperature is predetermined. It is exemplified that the value is equal to or more than a value, the charge amount of the battery 45 is equal to or more than a predetermined value, and the shift position sensor 55 is normal.

When a negative determination is made in step 2, the indicator 6 indicates that the stop control of the engine 1 has not been executed.
It is output from 7 and notified to the driver (step 3), and the process is returned. When a positive determination is made in step 2, the foot brake pedal 63 is detected based on the signal from the foot brake switch 57 or the signal from the brake pedal force sensor 64.
It is determined whether or not is depressed (step 4).

If a negative determination is made in step 4, the engine 1 stop control is not performed (step 5), and the process proceeds to step 3. If an affirmative decision is made in step 4, it is decided whether or not the vehicle has suddenly stopped from the state of continuous high-speed running (that is, the vehicle speed is equal to or higher than a predetermined value for a predetermined time or longer). It This determination is made based on the vehicle speed history and the amount of change. It is also possible to determine a sudden stop from the continuous high speed running state based on the change in vehicle speed and the change in acceleration. For this reason, the electronic control unit 47 uses the criteria such as the vehicle speed, the acceleration, the traveling time above the predetermined vehicle speed, the time from when the foot brake switch 57 is turned on to when the vehicle speed becomes zero, which is applied to the determination in step 20. The value is stored in advance. Based on these data, it is possible to determine whether or not the vehicle has traveled at a vehicle speed equal to or higher than a predetermined value and continuously for a predetermined time or longer, that is, so-called continuous high-speed traveling.

Then, in step 20, it is also possible to judge whether or not there is a sudden stop after continuous high speed running, and indirectly estimate the engine water temperature based on the judgment result.
This is because the content of the stop control of the engine 1 is changed according to the engine water temperature. Therefore, the reference value stored in the electronic control unit 47 is mapped corresponding to the engine water temperature.

The contents of the judgment in step 20 will be described with reference to the time chart of FIG. In other words, as indicated by the solid line, the time t1
When the foot brake switch 57 is turned on, the vehicle speed decreases from the subsequent time t2, and the acceleration changes from zero to the negative side as indicated by the solid line. Then, if at least one of the vehicle speed rapidly becoming zero and the negative acceleration showing a predetermined value or more and being stopped is detected within a predetermined short time from time t2, for example, at time t3,
It can be judged that it is a sudden stop from continuous high speed running. The vehicle speed shown by the broken line and the acceleration shown by the broken line show an example of the case where it is determined that the normal braking is stopped. When the normal braking is stopped, the vehicle is traveling at a lower vehicle speed than the continuous high-speed traveling, and the vehicle speed becomes zero at time t4, which is later than time t3. Further, the negative acceleration is controlled to a value closer to the zero side than during a sudden stop after continuous high speed running.

When a negative determination is made in step 20, the process proceeds to step 5. Further, when the affirmative judgment is made in Step 20, as shown in FIG.
The timing (time) TSTOP from when the engine is turned on to when the engine stop command is output is changed to that corresponding to the sudden stop from continuous high speed running (step 21). Specifically, after the continuous high-speed running is determined, a predetermined time from the satisfaction of the stop condition to the output of the stop command, that is, the timing TSTOP is greater than the timing TSTOP corresponding to the other normal braking stop. Set long.
That is, when the sudden stop from the continuous high speed running is detected, the stop control of the engine 1 is less likely to be performed than when the normal braking stop is detected. It is also possible to set the timing TSTOP corresponding to a sudden stop from high speed running to infinity so that the stop control of the engine 1 is not performed.

After step 21, it is determined whether or not the stop start condition is satisfied, that is, the time TS set in step 20.
It is determined whether or not TOP has elapsed, and it is determined whether the vehicle speed is zero and the accelerator pedal 59 is off (step 22). When a negative determination is made in step 22, the process proceeds to step 5, step 22
If the affirmative judgment is made in step 1, the process returns through steps 8 and 9. Here, the correspondence between the functional means shown in FIG. 1 and the present invention will be described. Step 20 corresponds to the running state determining means and the engine water temperature determining means of the present invention, and steps 5, 8, 21 are performed. , 22 correspond to the stop prohibition means and the stop holding means of the present invention. Further, the water cooling type cooling device 77 corresponds to the cooling device of the present invention.

As described above, according to the control example of FIG. 1, the time TSTOP when it is determined that the vehicle suddenly stops from the continuous high speed traveling and the time TSTOP when it is determined that the normal braking is stopped. Is different. That is,
If the vehicle stops due to sudden braking from continuous high speed running,
In order to suppress overheating of the engine 1, a water cooling type cooling device 7
It is preferable that 7 is driven. Therefore, in the control example of FIG. 1, when it is determined that the sudden stop from continuous high speed running, the engine water temperature may be equal to or higher than a predetermined value or may rise to a predetermined value or higher based on the determination result. Therefore, the time TSTOP is set as long as possible. Therefore, according to this control example, the engine water temperature controllability with respect to the state of the vehicle is improved, and overheating of the engine 1 can be suppressed.

In the control example of FIG. 1, when the time TSTOP corresponding to the sudden stop from the continuous high speed running is set, the engine 1 can be stopped until the vehicle speed thereafter increases to a predetermined value or more. It is also possible to perform control so that it cannot return to. This is to prevent the cooling function of the water-cooled cooling device 77 from stopping due to the stop of the engine 1.

In the above control example, as a method of changing (changing) the time TSTOP according to the situation, a method of correcting the reference time TSTOP previously stored in the electronic control unit 47 by an arithmetic process and a method of preliminarily performing the situation According to the above, a plurality of times TSTOP are stored in the electronic control unit 47,
A method of replacing these times TSTOP depending on the situation is included.

[0081]

According to the first aspect of the present invention, the engine stop control can be prohibited when the stop condition is satisfied after it is determined that the vehicle has been continuously driven at high speed. Therefore, it is possible to suppress a decrease in the cooling function of the cooling device and suppress an increase in engine temperature.

According to the second aspect of the present invention, when the stop condition is satisfied after it is determined that the vehicle has continuously traveled at high speed, a predetermined time period elapses after the stop condition is satisfied. , Suspend the engine stop control. Therefore, it is possible to suppress the deterioration of the cooling function of the cooling device and suppress the temperature rise of the engine until a predetermined time elapses.

According to the third aspect of the present invention, when it is estimated that the engine water temperature is equal to or higher than the predetermined value or may rise to the predetermined value or higher, the engine is cooled even if the stop condition is satisfied. Either the control for prohibiting the stop control or the control for suspending the engine stop control for a predetermined time after the stop condition is satisfied is selected. Therefore, the cooling function of the cooling device can be maintained, and the temperature rise of the engine can be suppressed.

According to the invention of claim 4, in addition to the effect similar to that of the invention of claim 3, the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher, and after that. When the vehicle speed becomes zero within a predetermined time, it can be determined that the vehicle has stopped suddenly.

According to the invention of claim 5, in addition to the same effect as that of the invention of claim 3, the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher, and thereafter. When the vehicle is stopped with the negative acceleration showing a predetermined value or more, it can be determined that the vehicle has suddenly stopped.

[Brief description of drawings]

FIG. 1 is a flowchart showing a control example of the present invention.

FIG. 2 is a block diagram showing a system configuration of a vehicle to which the present invention is applied.

FIG. 3 is a schematic diagram showing a part of a hydraulic circuit of the hydraulic control device shown in FIG.

FIG. 4 is a block diagram showing a positional relationship among the engine shown in FIG. 2, a drive device, and a motor / generator.

5 is a block diagram showing a control circuit of the vehicle shown in FIG.

FIG. 6 is a conceptual diagram showing a configuration of a foot brake pedal and a foot brake pedal force sensor of the vehicle shown in FIG.

FIG. 7 is a time chart showing a state of the system corresponding to an engine automatic stop command in the present invention.

FIG. 8 is a time chart showing a state of the system corresponding to an engine automatic return command in the present invention.

FIG. 9 is a map for setting the duration of the first apply control in the embodiment of the present invention.

10 is a time chart showing the state of the system corresponding to the control example of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 16 ... Hydraulic control device, 47 ... Electronic control device, 57 ... Foot brake switch, 77 ... Water cooling type cooling device, A1 ... Automatic transmission.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shuji Nagano             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Mitsuhiro Tabata             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F term (reference) 3G084 AA01 BA05 BA33 CA01 CA06                       CA07 DA02 DA25 EA07 EA11                       FA06 FA10 FA20 FA27 FA33                       FA36                 3G092 AA01 AA02 AB02 AB03 AB07                       DC03 DG08 EA08 EA14 EA17                       FA24 FA30 FB06 GA01 GA10                       GA13 HD02Z HE01Z HE08Z                       HF04Z HF08Z HF13Z HF19Z                       HF21Z HF26Z                 3G093 AA05 AB01 BA19 BA21 BA22                       CA01 CB07 DA01 DA04 DA06                       DA12 DA13 DB05 DB12 DB15                       DB25 EA09 EB09 EC02 FA11

Claims (5)

[Claims] 1. An automatic stop / return control for automatically changing an engine between a stopped state and an operating state can be performed based on a predetermined stop condition or return condition, and is driven by the power of the engine. In the engine control device of the vehicle capable of cooling the engine by the cooling device, it is determined whether or not the vehicle has been continuously driven at a high speed for a predetermined time or longer at a predetermined speed or more. It is provided with a running state judging means and an automatic stop prohibiting means for prohibiting the automatic stop control of the engine when the stop condition is satisfied after it is judged that the continuous high speed running has been performed. The vehicle engine control device. 2. An automatic stop / return control for automatically changing the engine between a stopped state and an operating state can be performed based on a predetermined stop condition or a return condition, and the engine is driven by the power of the engine. In the engine control device of the vehicle capable of cooling the engine by the cooling device, it is determined whether or not the vehicle has been continuously driven at a high speed for a predetermined time or longer at a predetermined speed or more. When the stop condition is satisfied after it is determined that the continuous high-speed travel has been performed, the running state determination means keeps the engine running until a predetermined time elapses after the stop condition is satisfied. An engine control device for a vehicle, comprising: an automatic stop holding means for holding the automatic stop control. 3. An engine control device for a vehicle, which is capable of performing automatic stop / return control for automatically changing an engine between a stopped state and an operating state based on a predetermined stop condition or return condition. Based on a running state judging means for judging whether or not the vehicle has continuously traveled at a high speed and suddenly stopped, and that the engine water temperature is equal to or higher than a predetermined value based on the judgment result of the running state judging means, or An engine water temperature determining means for estimating that the engine water temperature may rise above a certain value, and the engine water temperature determining means may determine that the engine water temperature is above a predetermined value or may rise above a predetermined value. If it is estimated, even if the stop condition is satisfied, the control for prohibiting the stop control of the engine or a predetermined time has elapsed after the stop condition is satisfied. An engine control device for a vehicle, comprising: a stop holding unit that selects either one of the controls for holding the engine stop control until the engine passes. 4. The vehicle running state determination means, when the foot brake switch is turned on while the vehicle is continuously traveling at a predetermined vehicle speed or higher and the vehicle speed becomes zero within a predetermined time thereafter. The engine control device for a vehicle according to claim 3, further comprising a function of determining that the vehicle has suddenly stopped. 5. The running condition determination means, when the footbrake switch is turned on during continuous high-speed running of the vehicle at a predetermined vehicle speed or higher, and then the vehicle is stopped with a negative acceleration of a predetermined value or higher, The engine control device for a vehicle according to claim 3, further comprising a function of determining that the vehicle has suddenly stopped.