JP2001130284A - Vehicle creep control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To generate creep force without using a driving source such as an engine at an extremely low vehicle speed including when the vehicle is stopped, and to operate in a traffic jam, when entering a garage, or when starting on a slope. Improve sex. When the brake operation force BK becomes equal to or less than a determination value BKs during an eco-run in which the engine 10 is stopped, a flywheel clutch 72 and an input clutch 17 are connected to thereby store the rotation stored in the energy-saving flywheel 70. The vehicle runs by generating creep force with energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a creep control device for a vehicle, and more particularly to a creep control device for a vehicle in which the operation of a driving source for driving is stopped when the vehicle stops.

[0002]

2. Description of the Related Art (a) An engine that generates power by burning fuel, and (b) a flywheel for energy storage that is rotated during vehicle running to store rotational energy.
(c) a flywheel clutch for connecting and disconnecting the energy storage flywheel to and from the power transmission shaft,
(d) stopping the engine when the vehicle stops,
A technology for starting the engine by cranking the engine with the energy storage flywheel at the time of restart is proposed in an eco-run system or the like. The apparatus described in Japanese Patent Application Laid-Open No. 58-9859 is one example.

[0003]

However, since such a conventional eco-run system generally starts the engine when the brake operation is released, the conventional eco-run system generally has a fluid coupling such as a torque converter. Like an automatic vehicle, it is not possible to run the vehicle only due to the strength of the brake operation during congestion or garage entry, and there is a possibility that it will retreat on a slope start,
There was a problem that the usability was poor. It is conceivable to detect the braking force and start the engine when the braking force becomes weak to generate creep force.However, in traffic jams where running and stopping are repeated, starting and stopping the engine repeatedly may lead to lower fuel efficiency. Absent.

The creep force is such a driving force that the vehicle can travel at extremely low speed on flat ground. In a normal automatic vehicle, the engine output in an idle state is transmitted to the wheels via a torque converter. Obtained by:

The present invention has been made in view of the above circumstances, and an object of the present invention is to generate a creep force without using a drive source such as an engine at an extremely low vehicle speed including a stop of the vehicle. Accordingly, it is an object of the present invention to improve operability during traffic congestion, when entering a garage, or when starting on a slope.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a flywheel for energy storage for storing rotational energy by being rotated during running of a vehicle, and a driving source for running when the vehicle is stopped. In the vehicle in which the operation of the vehicle is stopped, when the vehicle speed is equal to or lower than a predetermined low vehicle speed including when the vehicle is stopped and the brake is operated, the power stored in the energy storage flywheel is not operated without operating the traveling drive source. It has a creep force generating means for generating a creep force by rotational energy. The brake operation means that a service brake such as a foot brake is operated by the driver.

[0007]

According to such a creep control device,
When the vehicle speed is lower than a predetermined low vehicle speed including when the vehicle is stopped and the brake is operated, the creep force is generated by the rotational energy accumulated in the flywheel for energy storage, so that during a traffic jam similar to a normal automatic vehicle. The operability is improved, for example, the vehicle can be driven only by the strength of the brake operation when the vehicle is put in a garage or the like, and the vehicle is prevented from retreating on a slope start. Further, since it is not necessary to operate the driving source for traveling, fuel consumption and the like can be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is suitably applied to a vehicle provided with an engine for generating power by burning fuel as a driving source for driving. For example, an electric motor and a fuel cell are used as driving driving sources for driving. Even when the electric motor is operated with electric energy generated by the fuel cell, it is possible to save fuel of the fuel cell by performing creep traveling by the flywheel for energy storage without operating the fuel cell, The present invention can be applied to various vehicles in which the operation of the driving source for driving is stopped when the vehicle stops.

The energy storage flywheel may be disposed between a drive source for traveling and a fluid coupling such as a torque converter, or may be disposed between a fluid coupling and an automatic transmission. Can be employed in various arrangements. Not only does it generate creep,
It can also be used for cranking when starting the engine. Note that a fluid coupling such as a torque converter and an automatic transmission are not necessarily essential to the present invention.

Since there is a limit to the amount of energy stored in the flywheel for energy storage, it is impossible to always generate a creep force during a brake operation at a predetermined low vehicle speed or lower. When a predetermined creep start condition is satisfied, for example, when the brake request amount of the vehicle falls below a predetermined value or when the driver selects creep running by operating a switch or the like, the creep force generating means uses the energy storage flywheel. It is desirable to generate a creep force at the pressure.

Specifically, for example, (a) an engine that generates power by burning fuel, (b) a flywheel for energy storage that is rotated when the vehicle is running to store rotational energy, and (c) A flywheel clutch for connecting and disconnecting the energy storage flywheel to and from the power transmission shaft. (D) In a vehicle for stopping the engine when the vehicle is stopped, (e) a driver's brake operating force, etc. (B) a brake request amount detecting means for detecting a brake request amount of
When the brake operation is performed at a predetermined low vehicle speed or less, including when the vehicle is stopped, and the brake demand detected by the brake demand detection means is a predetermined value or less, the flywheel clutch is engaged to engage the fly for energy storage. And a creep force generating means for generating a creep force by the rotational energy stored in the wheel.

As the flywheel clutch, an electromagnetic friction clutch is preferably used. The magnitude of the creep force may be controlled by controlling the engagement of the flywheel clutch or another clutch provided between the flywheel clutch and the wheel. Further, when the braking force is mechanically adjusted according to the braking operation force, the braking force (for example, hydraulic pressure) may be detected as the required brake amount.

[0013] Also, during the enrun to stop the engine,
Based on the amount of energy stored in the energy storage flywheel (e.g., rotation speed), it is determined whether or not creep traveling with the energy storage flywheel is possible. If creep traveling is not possible, the eco-run is stopped and the engine is started immediately. It is desirable to provide an engine starting means for starting energy storage when the engine is short of energy, to generate a creep force by the engine instead of the flywheel for energy storage, or to quickly start the vehicle with the accelerator operation.

In the control for engaging the flywheel clutch during running of the vehicle to accumulate rotational energy in the flywheel for energy storage, it is desirable to rotate the flywheel for energy storage with the kinetic energy of the vehicle, for example, during coasting. However, for example, when the gear position of the automatic transmission does not transmit power from the wheel side to the engine side, it is also possible to rotate the energy storage flywheel with the power of the engine to accumulate rotational energy.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a vehicle drive device to which the present invention is applied, and FIG. 2 is a skeleton diagram in which a lower half from a center line is omitted. In these figures, an output of an engine 10 that generates power by burning fuel is input to an automatic transmission 14 via a torque converter 12 as a fluid coupling, and is driven via a differential gear device and an axle (not shown). It is transmitted to the wheel. Torque converter 1
2 is an input clutch 1 on the crankshaft 16 of the engine 10.
Impeller 18 connected to the automatic transmission 1
4 is prevented from rotating in one direction by a turbine wheel 22 connected to the input shaft 20 of the fourth wheel, a lock-up clutch 24 directly connecting the pump wheel 18 and the turbine wheel 22, and a one-way clutch 26. And a stator 28. The engine 10 corresponds to a driving source for traveling.

The automatic transmission 14 includes a first transmission 30 for switching between high and low gears, and a second transmission 32 for switching between a reverse gear and four forward gears. The first transmission 30 includes a sun gear S0, a ring gear R
0, an HL planetary gear unit 34 composed of a planetary gear P0 rotatably supported by the carrier K0 and meshed with the sun gear S0 and the ring gear R0, and a clutch provided in parallel between the sun gear S0 and the carrier K0. C0 and a one-way clutch F0, and a brake B0 provided between the sun gear S0 and the housing 41, and a carrier K0 is connected to the input shaft 20;
The ring gear R0 is connected to the intermediate shaft 44.

The second transmission 32 has a first planetary gear unit 36 comprising a sun gear S1, a ring gear R1, and a planetary gear P1 rotatably supported by the carrier K1 and meshed with the sun gear S1 and the ring gear R1.
, A sun gear S2, a ring gear R2, and a carrier K
2 and a second planetary gear set 38 comprising a planet gear P2 rotatably supported by the sun gear S2 and the ring gear R2, and rotatably supported by the sun gear S3, the ring gear R3 and the carrier K3. And S3 and a third planetary gear set 40 including a planetary gear P3 meshed with the ring gear R3.

The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2 and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 42. Further, a ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 44, and the sun gear S1 and the sun gear S3 are provided.
A clutch C2 is provided between the clutch shaft 2 and the intermediate shaft 44. A band-type brake B1 for stopping rotation of the sun gear S1 and the sun gear S2 is provided on the housing 41.
It is provided in. A one-way clutch F1 is provided between the housing 41 and the sun gear S1 and the sun gear S2.
And a brake B2 are provided in series. The one-way clutch F1 is configured to be engaged when the sun gear S1 and the sun gear S2 try to reversely rotate in the direction opposite to the input shaft 20.

A brake B3 is provided between the carrier K1 and the housing 41, and a brake B4 and a one-way clutch F2 are provided between the ring gear R3 and the housing 41 in parallel. This one-way clutch F
2 is configured to be engaged when the ring gear R3 attempts to rotate in the reverse direction.

Such an automatic transmission 14 is, for example, shown in FIG.
Are switched to one of the first reverse gear and the fifth forward gear in which the speed ratio is sequentially different. FIG.
In the table, “○” indicates the engaged state, blank indicates the released state, “●” indicates the engaged state when the engine brake is generated, and “△” indicates that the engaged state is not related to the power transmission. Represents. Clutches C0-C2 and brakes B0
B4 (hereinafter, simply referred to as clutch C or brake B unless otherwise specified) is a multi-plate type, a single-plate type in which a friction material is frictionally engaged based on the hydraulic pressure when hydraulic oil is supplied to a hydraulic cylinder. , A band-type friction engagement device, and a plurality of AT solenoid valves 98 for shifting.
(See FIG. 6) and the like, the engagement and release states can be switched.

The shift lever 46 (see FIG. 4) operated according to the shift pattern shown in FIG. 5 has the engine brake positions "3", "2",
When operated to any of the "L" positions,
The engine brake is generated at the highest gear. For example, in the "L" position in which the vehicle travels only in the first gear (1st), the brake B4 is engaged so that the accelerator pedal is not operated (accelerator OF).
F), the engine brake is generated in the non-driving (power OFF) running, but the shift lever 4
When the vehicle is traveling in the first gear (1st) in which the gear 6 is operated to the "D" position, the brake B4 is released. Since the slip of the direction clutch F2 and the idling of the ring gear R3 are allowed, the power transmission path is released in the automatic transmission 14, and the vehicle is coasted without the engine brake being applied. In the “2” position where the shift is performed in the first gear (1st) and the second gear (2nd), the second gear (2n) is set.
At the time of traveling d), the engine brake is enabled by engaging the clutch C0, and the clutch C0 is released at the second speed (2nd) in the “D” position, whereby the one-way clutch F0 is released. Slip is allowed and coasting is performed. Also, the first gear (1)
In the "3" position where the shift is performed in the range from st) to the third speed (3rd), the engine brake is enabled by engaging the brake B1 during traveling at the third speed (3rd). In the "D" position, the one-way clutch F1 is allowed to slip by releasing the brake B1, and coasting is performed.

The shift lever 46 is located at a P (parking) position, an R (reverse) position, an N (neutral) position, a D (drive) position, a D (drive) position, a 4-position, and a 3-position, as shown in FIG. The support mechanism is configured to be operated to the 2 position, the L (low) position, and to be operated between the D position and the 4 position in the left-right direction of the vehicle. When the gear is operated to the D position, a D range for performing shift control in the first gear (1st) to the fifth gear (5th) is set, and when the gear is operated to the fourth position, the first gear ( Four ranges for performing shift control in the first gear to the fourth gear (4th) are set, and when operated to the third position, the first gear (1st) to the third gear (3r)
In d), three ranges for performing the shift control are set, and when operated to the second position, two ranges for performing the shift control in the first gear (1st) and the second gear (2nd) are set, and the L position is set. To the first gear (1s
The L range fixed to t) is set. A sports mode switch 48 is provided in the vicinity of the shift lever 46. By operating an up-range switch or a down-range switch (not shown) provided on a steering wheel or the like, the driver can arbitrarily select a travel range (L range to L range).
4 ranges).

The shift lever 46 has a manual valve 60 provided in the hydraulic control unit 50 as shown in FIG.
Are mechanically connected via a cable, a link mechanism, or the like, and the hydraulic oil supplied from the mechanical oil pump 52 or the electric oil pump 54 via the primary regulator valve 56 is operated by the operating position (shift) of the shift lever 46. The position is output to the clutch C and the brake B according to the position. The mechanical oil pump 52 is rotationally driven by the engine 10 integrally with the pump impeller 18 of the torque converter 12. The electric oil pump 54 operates independently of the operation of the engine 10 by a controller (ECU) shown in FIG. ) 62. The hydraulic control unit 50 is also provided with an input clutch control solenoid valve 58. The input clutch 1 is controlled by controlling the hydraulic pressure of hydraulic oil supplied from the primary regulator valve 56.
7 are engaged, released, and slip-engaged. The input clutch 17 is connected to the clutch C or the brake B
This is a hydraulic friction engagement device similar to that described above.

Returning to FIG. 1, the engine 10 is configured to be cranked by a starter 64 having an electric motor and a pinion, and the engine 10 is connected to the crankshaft 16 via a driving device 66 such as a belt or a chain. The motor generator 68 is connected. The motor generator 68 generates power by regenerative braking at the time of a brake operation or the like, charges a battery (not shown), and drives auxiliary equipment such as an air conditioner. A clutch is provided between the motor generator 68 and the engine 10 as necessary. Also, Engine 1
As shown in FIG. 2, a flywheel 70 for energy storage is arranged between 0 and the input clutch 17 so that the flywheel 70 is connected to and disconnected from the crankshaft 16 via a flywheel clutch 72. It has become. The energy storage flywheel 70 is a mass body that stores rotational energy by being rotated when the vehicle is running.
The engine has a mass capable of accumulating rotational energy such that the vehicle can be started by cranking or a creep running of about 5 m can be performed from a vehicle stopped state. The flywheel clutch 72 is an electromagnetic friction clutch.
The crankshaft 16 corresponds to a power transmission shaft.

FIG. 6 is a diagram showing a control system of the vehicle drive device of this embodiment. Various signals are input to the controller 62 from switches and sensors shown on the left side of FIG. By performing signal processing according to a program stored in advance in a ROM or the like and outputting control signals or the like to various devices shown on the right side, for example, output control of the engine 10 and shift control of the automatic transmission 14 are performed. The flywheel rotation speed sensor 74 shown on the left side of FIG. 6 is a sensor that detects the rotation speed NF of the energy storage flywheel 70, and the engine rotation speed sensor 7
6 is a sensor for detecting the rotational speed NE of the engine 10;
The vehicle speed sensor 78 detects the rotation speed Nout of the output shaft 42 (vehicle speed V
Corresponding to the input shaft rotation speed sensor 8
0 is the rotation speed Nin of the input shaft 20 (strictly speaking, the clutch C0
Sensor for detecting the rotational speed of the motor). The engine water temperature sensor 82 is a sensor that detects the engine water temperature Tw, and the AT oil temperature sensor 84 is an AT oil temperature T _AT (automatic transmission 1).
4, a shift position switch 86 is a switch for detecting a shift position (operating position) of the shift lever 46, and a foot brake switch 88 is a switch for detecting the presence or absence of a foot brake operation. The accelerator opening sensor 90 is a sensor that detects an operation amount (accelerator opening) θth of an accelerator pedal, and the brake force sensor 92 is a sensor that detects an operation force (pedal depressing force) BK of a foot brake which is a driver's brake request amount. Corresponds to a brake request amount detecting means. The throttle valve of the engine 10 is mechanically connected to an accelerator pedal so as to be opened and closed, and a throttle valve opening sensor can be used instead of the accelerator opening sensor 90.

An ignition device 94 shown on the right side of FIG. 6 controls the ignition of the engine 10, an injection device 96 controls the fuel injection amount of the engine 10, and an AT solenoid valve 98 controls the clutch C and the brake. A gear shift control is performed by engaging and disengaging B.
00 controls the brake oil pressure of the wheel brake so that the wheels do not lock.

FIG. 7 is a flow chart for explaining the operation when the rotational energy is stored in the energy-saving flywheel 70 during running of the vehicle, and is repeatedly executed at a predetermined cycle time by the signal processing by the controller 62.

In step S1 of FIG. 7, various signals necessary for this control are read, and in step S2,
It is determined whether the vehicle is running based on the vehicle speed V (output shaft rotation speed Nout) detected by the vehicle speed sensor 78. If it is not running, the flywheel clutch 7 is turned on in step S3.
2 is released, but if the vehicle is traveling, it is determined in step S4 whether or not the energy storage amount of the energy storage flywheel 70 has reached a predetermined amount, for example, by determining a flywheel rotation speed NF to a predetermined determination value NF. ^* Judge based on whether or not. If the elapsed time after the vehicle stops is, for example, about 5 minutes, the determination value NF ^* is to restart the engine 10 by cranking the engine 10 by the energy storage flywheel 70 or to perform creep running of about 5 m from the vehicle stopped state. At a rotational speed corresponding to the rotational energy at which the energy can be carried out, such as the mass of the flywheel 70 for energy storage, the friction of the bearing portion, the rotational resistance of the engine 10, the rotational speed required for self-rotation at the time of starting, and the like. Accordingly, a constant value is set in advance by an experiment or the like. If the energy storage amount has reached the predetermined amount, no more rotational energy is required, so that the flywheel clutch 72 is released and the energy storage flywheel 70 is freely rotated in step S3, while the predetermined amount is maintained. If not reached, step S5 and subsequent steps are executed to engage the flywheel clutch 72 under predetermined conditions to accumulate rotational energy.

In step S5, it is determined whether or not the regenerative mode is suitable for rotating the energy storage flywheel 70 by the kinetic energy of the vehicle to store the rotational energy. Specifically, for example, the accelerator pedal is not depressed. It is determined whether or not the accelerator is in a coast state (engine brake state). If not in the regenerative mode, the flywheel clutch 72 is released in step S3. In the regenerative mode, in step S6, it is determined whether or not the automatic transmission 14 is shifting, for example, the output state of a command signal to the AT solenoid valve 98. And the actual gear ratio (= input shaft rotation speed Nin / output shaft rotation speed Nout). During the shift, the flywheel clutch 72 is released in step S7 because the shift control is easier if the inertia is as small as possible, but if the shift is not in progress, the flywheel clutch 72 is engaged in step S8.
The rotational energy is accumulated by rotating the energy storage flywheel 70 with the kinetic energy of the vehicle.

When the flywheel clutch 72 is suddenly engaged, a large driving force fluctuation occurs due to the inertia of the energy storage flywheel 70. Therefore, in the above-mentioned step S8, for example, the rotation speed NF of the energy storage flywheel 70 is increased by a predetermined amount. The engagement control of the flywheel clutch 72 is performed so as to increase at a rate. In the next step S9,
The braking force of the wheel brake is corrected (decreased) by the braking force control means such as the ABS actuator 100 so as to offset the increase in the deceleration of the vehicle speed V due to the increase in the rotation speed NF of the energy storage flywheel 70. Vehicle speed V
Energy correction flywheel 70
It is desirable that the rotation energy is accumulated when the brake is ON, that is, when the foot brake is depressed, but it can be accumulated even when the brake is OFF, in which case the rotation speed NF increases slightly compared to when the brake is ON. It is desirable to control the engagement of the flywheel clutch 72 so as to increase at a rate.

In step S10, it is determined whether or not the amount of energy stored in the energy storage flywheel 70 has reached a predetermined amount in the same manner as in step S4. When the predetermined amount is reached, the flywheel clutch 72 is released and the energy storage flywheel 70 is freely rotated in step S11. Step S4 and subsequent steps are executed following step S9, and step S1 is executed.
It is substantially the same even if O and S11 are omitted.

FIG. 8 shows the state of the engine 10 when the vehicle is stopped.
The engine 10 is cranked and restarted by the rotational energy stored in the energy storage flywheel 70 under predetermined engine restart conditions, or when predetermined creep start conditions are satisfied. FIG. 4 is a flowchart illustrating an operation when a creep force is generated by the rotational energy stored in the energy storage flywheel 70 without restarting the engine 10 in a predetermined cycle time by the signal processing by the controller 62. It is executed repeatedly.

At step R1 in FIG. 8, various signals necessary for the present control are read. At step R2, it is determined whether or not the vehicle is in the eco-run, for example, when the vehicle speed V is a predetermined low vehicle speed (for example, 3 to 5 km / H) or less and the engine 1
Judgment is made based on whether or not 0 is a stop state. Then, during the eco-run, it is determined in step R3 whether or not the return condition is satisfied. If the return condition is satisfied, step R4 and subsequent steps are executed to restart the engine 10. The return condition is equivalent to the engine restart condition, and is satisfied, for example, under any one of various eco-run conditions, for example, when the foot brake is ON, the accelerator is OFF, the engine water temperature Tw is a predetermined value or more, and the AT oil temperature T _AT is a predetermined value or more. Disappearing, and so on.

In step R4, the flywheel clutch 72 is engaged, and the engine 10 is cranked with the rotational energy stored in the energy-saving flywheel 70. At this stage, by operating the electric oil pump 54 and engaging the clutch C and the brake B of the automatic transmission 14, a predetermined gear stage is established. In step R5, engine start processing such as ignition and fuel injection is performed to start the engine 10, and the hill hold brake is released in step R6. The hill hold brake is for surely maintaining the vehicle in a stopped state during the eco-run, and is implemented by maximizing the brake force of the wheel brake by a brake force control means such as the ABS actuator 100 or the like. When the engine 10 can rotate by itself, the flywheel clutch 72 is released and the input clutch 17 is released.
To transmit the engine output to the drive wheels. Also,
When the discharge pressure (or rotation speed or the like) of the mechanical oil pump 52 becomes higher than a predetermined value by the operation of the engine 10, the operation of the electric oil pump 54 is stopped.

If the determination in step R3 is NO,
That is, when the return condition is not satisfied and the eco-run is maintained
Is determined by the energy storage flywheel 70 in step R7.
Example of whether creep running or starting of engine 10 is possible
For example, the amount of energy stored in the flywheel 70 for energy storage
The corresponding rotation speed NF is a predetermined minimum value NFmin
Judgment is made based on whether or not it is smaller. Minimum value NFmin
The engine 10 is cranked and restarted,
Doing creep running of about 5m from the stopped state
Speed corresponding to the minimum rotational energy required for
And the determination value NF ^*It is a smaller value. And
If NF ≧ NFmin, the processing from step R8 is executed.

In step R8, it is determined whether or not the driver's brake operation force BK is equal to or less than a predetermined determination value BKs. If BK> BKs, it is determined that the driver has no intention to drive the vehicle. In step R12, the execution of the hill hold brake is maintained. However, when BK ≦ BKs, step R9 and subsequent steps are executed to generate the creep force with the rotational energy accumulated in the energy storage flywheel 70. The determination value BKs is for determining whether or not the driver wants to perform creep running, and may be a constant value smaller than the operating force at the time of a normal brake operation for maintaining the vehicle in a stopped state. Is the braking force BK
May be set in a data map or the like as a parameter, such as a road surface gradient or the number of occupants that affects the vehicle. Satisfying the relationship of BK ≦ BKs is a creep start condition. Note that the brake OF with the brake operation force BK = 0
In the case of F, the determination in step R3 is YES,
The engine 10 is restarted by executing step R4 and subsequent steps. The creep start condition may include that the shift lever 46 is operated to a drive position other than N and P.

In step R9, the flywheel clutch 72 is engaged, and in step R10, the electric oil pump 5 is engaged.
4, the input clutch 17 is engaged, and the clutch C and the brake B of the automatic transmission 14 are engaged to establish a predetermined gear. Step R11
Then, the hill hold brake is released in the same manner as in step R6. As a result, the rotational energy stored in the energy storage flywheel 70 is transmitted from the crankshaft 16 to the torque converter 12 via the input clutch 17, and further transmitted from the automatic transmission 14 to the drive wheels, generating a predetermined creep force. Let me do. It is desirable to suppress sudden drive force fluctuation by gradually increasing the engagement torque (oil pressure) of the input clutch 17.

If the determination in step R7 is NO, that is, if NF <NFmin, the flywheel 70 for energy storage
It is impossible to start the engine or creep running by
The eco-run is stopped by starting the engine 10 by executing step R13 and subsequent steps. That is, step R
At step 13, the engine 10 is cranked by the starter 64, and at step R14, the engine 10 is started by performing engine start processing such as ignition and fuel injection. In step R15, the hill hold brake is released as in step R6.

In this embodiment, when the brake operation force BK becomes equal to or less than the determination value BKs during the eco-run in which the engine 10 is stopped, the step R9 and the subsequent steps are executed to execute the rotation accumulated in the energy storage flywheel 70. Since energy generates creep force, the vehicle can be driven only by the strength of the brake operation during traffic congestion or garage parking just like a normal automatic vehicle, and the vehicle retreats on a hill start is suppressed,
Operability is improved. Further, since there is no need to operate the engine 10, fuel consumption is reduced.

When it is impossible to start the engine or creep the engine by the energy storage flywheel 70, the engine 10 is started by the starter 64 immediately after the eco-run is stopped. Instead of 70, it is possible to generate a creep force by the engine 10 or to start the vehicle promptly with an accelerator operation.

In the series of signal processing by the controller 62, the part that executes steps R8, R9, R10, and R11 functions as a creep force generating means, and the part that executes steps R7, R13, and R14 has insufficient energy storage. It functions as an engine starting means.

Although the flywheel 70 for energy storage is disposed between the engine 10 and the input clutch 17 in the above-described embodiment, the flywheel 70 is disposed between the input clutch 17 and the torque converter 12 as shown in FIG. A flywheel 70 for energy storage may be provided, or a flywheel 70 for energy storage may be provided between the torque converter 12 and the automatic transmission 14 as shown in FIG. In this case, it is possible to perform creep running by the energy storage flywheel 70 while the input clutch 17 is released, and the energy loss due to the rotation of the engine 10 is reduced.

Although the embodiment of the present invention has been described in detail with reference to the drawings, this is merely an embodiment,
The present invention can be implemented in various modified and improved aspects based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle drive device to which the present invention is applied.

FIG. 2 is a skeleton view of the vehicle drive device of FIG. 1;

FIG. 3 is a diagram illustrating a relationship between a plurality of gear positions of the automatic transmission of FIG. 1 and an operation state of a hydraulic friction engagement device for establishing the gear positions.

FIG. 4 is a diagram illustrating a part of a hydraulic circuit included in the hydraulic control unit of FIG. 1;

FIG. 5 is a diagram illustrating an operation position of a shift lever of the vehicle drive device of FIG. 1;

FIG. 6 is a block diagram illustrating a control system provided in the vehicle drive device of FIG. 1;

FIG. 7 is a flowchart illustrating the operation of the vehicle drive device of FIG. 1 when rotational energy is stored in the energy storage flywheel during vehicle running.

FIG. 8 illustrates an operation of the vehicle drive device of FIG. 1 in a case where a creep force is generated by a flywheel for energy storage when a predetermined creep start condition is satisfied in eco-run control for stopping an engine when the vehicle stops. FIG.

FIG. 9 is a skeleton diagram showing another example of a vehicle drive device to which the present invention is suitably applied, and is a diagram corresponding to FIG. 2;

10 is a skeleton diagram showing still another example of a vehicle drive device to which the present invention is suitably applied, and is a diagram corresponding to FIG.

[Explanation of symbols]

10: Engine (drive source for traveling) 62: Controller 70: Flywheel for energy storage 72: Flywheel clutch Step R8 to R11: Creep force generating means

Claims (1)

[Claims] 1. A vehicle having an energy storage flywheel for storing rotational energy by being rotated when the vehicle is running, wherein the operation of a driving source for driving is stopped when the vehicle is stopped. A creep force generating means for generating a creep force with the rotational energy stored in the energy storage flywheel without operating the driving source for driving when the vehicle speed is lower than the vehicle speed and the brake is operated. A creep control device for a vehicle.