JP2001208177A - Controller of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller capable of coping with the requirement on quick gear change during traveling in stopping an engine, and inhibiting the hydraulic pump driving output of an electric motor during the stop of the engine. SOLUTION: In a hybrid vehicle capable of being traveled and driven by transmitting the output of a metallic V belt-type continuously variable transmission 20 connected to an output shaft of an engine E to a driving wheel, and having a second motor generator 50 capable of driving the driving wheel in parallel with the engine, this controller controls the gear change to control a gear ratio of the continuously variable transmission to a value corresponding to an operating condition at that time by driving a second hydraulic pump 56 by a pump driving electric motor 55, and applying the oil pressure obtained from the second hydraulic pump during the traveling in stopping the engine, and starts the engine to drive a first hydraulic pump 3 to apply the oil pressure obtained from the first hydraulic pump for controlling the gear change when the requirement on the gear change too large to be coped by the control of the gear change by the oil pressure obtained from the second pump is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving system in which an engine output is transmitted to wheels via a continuously variable transmission to drive the vehicle, and the vehicle can be driven by a driving motor arranged in parallel with the engine. The present invention relates to a hybrid vehicle configured to temporarily stop an engine in a predetermined driving state and drive wheels by a drive motor to perform traveling driving.

[0002]

2. Description of the Related Art A hybrid vehicle adapted to run by using both an engine and an electric motor is known.
Practical applications are being pursued for the purpose of improving fuel efficiency of engines and purifying exhaust gas. An example of such a hybrid vehicle is disclosed in Japanese Patent Application Laid-Open No. H11-132321. The vehicle includes an engine, a belt-type continuously variable transmission connected to an output shaft of the engine via a torque converter, and a second motor generator connected to a power transmission system on the output side of the continuously variable transmission. And In this vehicle, the normal driving is performed by transmitting the engine driving force to the wheels by changing the speed by an infinitely variable transmission. When the vehicle is temporarily stopped, the engine is also temporarily stopped. The wheels are driven by a motor generator. Note that, when the vehicle is restarted in this way, the engine is restarted by the first motor generator, and after the vehicle starts running, the driving is switched to driving by the engine.

[0003] When the engine is stopped when the vehicle is temporarily stopped, the driving of the hydraulic pump by the engine is also stopped, and the control oil pressure of the continuously variable transmission is lost. Therefore, a second hydraulic pump driven by an electric motor is provided, and when the engine is stopped, the second hydraulic pump is driven by the electric motor to generate a predetermined hydraulic pressure, and the predetermined hydraulic pressure is output to an output pulley of the continuously variable transmission. The gear ratio is set to the maximum (LOW) by supplying the gear ratio to the cylinder chamber so as to prepare for the next start in a state where power transmission is possible. As described above, in the hybrid vehicle, when the vehicle is temporarily stopped, the engine is stopped to improve fuel efficiency, and at the time of starting, the second motor generator is driven to improve fuel efficiency.

On the other hand, recently, for the purpose of further improving the fuel economy, it has been considered that the engine is stopped while the vehicle is running at a relatively high speed and the vehicle is driven by an electric motor. However, in this case, if the control of the conventional hybrid vehicle as described above is used as it is,
In a case where the engine is stopped during traveling and the traveling drive by the electric motor is performed, control for maximizing the speed ratio (LOW) is performed, and thereafter, the driving is returned from the electric motor driving to the engine driving during traveling. Sometimes, the gear ratio is maximum (LOW) with respect to the vehicle speed at that time, so that the engine rotation is unnecessarily increased, and there is a problem that fuel efficiency and running performance (drivability) are impaired. For this reason, the present applicant uses the hydraulic pressure obtained by driving the second hydraulic pump by the electric motor to stop the engine when traveling to adjust the speed ratio of the continuously variable transmission according to the operating state at that time. It is considered that the shift control is performed so that the value becomes a value.

[0005]

The electric motor for driving the second hydraulic pump when the engine is temporarily stopped as described above is required to reduce the power consumption as much as possible due to the capacity of the battery and the like. The discharge capacity of the second hydraulic pump is made as small as possible, and the shift control oil pressure is made as low as possible. However, in the case of performing the shift control using the second hydraulic pump thus miniaturized, the achievable shift speed is limited. For example, a sudden braking operation is performed during traveling and the vehicle is suddenly decelerated and stopped. In this case, there is a problem that the shift control that follows the shift cannot be performed, that is, the shift control is delayed.

[0006] Specifically, for example, when the gear ratio is minimum (TO
When the vehicle is stopped at a relatively high speed in a state close to P), the brake is actuated, the vehicle is suddenly decelerated, and the vehicle is stopped in such a short time until the vehicle is suddenly stopped. Shift control for changing the speed ratio to the maximum (LOW) is required. However, since the shift speed achievable by reducing the size of the second hydraulic pump is small as described above, the shift ratio control is delayed, and the intermediate speed ratio cannot return to the maximum (LOW) when the vehicle is stopped. A state occurs in which it remains as it is.

Here, since control is generally performed to stop the engine when the vehicle is stopped for the purpose of improving fuel efficiency, the engine is stopped when the vehicle is stopped. In this state, the speed ratio remains at the intermediate speed ratio. Next, when the engine is started to start the vehicle, starting control is performed from the intermediate speed ratio, and there is a problem that a sufficient starting driving force cannot be obtained. Also, starting control after returning the gear ratio to the maximum (LOW) in order to obtain a sufficient driving force,
A problem arises in that the starting performance is impaired due to a delay in starting.

The present invention has been made in view of such a problem.
Even when a sudden shift request is caused by sudden deceleration or the like while the engine is stopped, such a shift request can be handled, and the hydraulic pump driven by the electric motor while the engine is stopped is downsized. It is an object of the present invention to provide a hybrid vehicle control device having a configuration capable of reducing the weight.

[0009]

In order to achieve the above object, according to the present invention, an engine (for example, engine E in the embodiment) which can be temporarily stopped in a predetermined operating state, and an output shaft of the engine are provided. (For example, a metal V-belt type continuously variable transmission mechanism 20 in the embodiment) that continuously changes the output rotation thereof and a driving force transmission that transmits an output of the continuously variable transmission to driving wheels. System (for example,
Idler shaft 31, final dry gear 32, final driven gear 33, differential mechanism 34, axle shaft 35, etc. in the embodiment)
And a hybrid vehicle including an electric drive motor (for example, the second motor generator 50 in the embodiment) disposed in parallel with the engine and capable of driving the drive wheels, and a control device of the hybrid vehicle is driven by the engine. First
A hydraulic pump (for example, the first hydraulic pump 3 in the embodiment) and a second hydraulic pump (for example, the second hydraulic pump in the embodiment) driven by an electric motor for driving the pump (for example, the electric motor 55 for driving the pump in the embodiment). And a hydraulic pump 56). This control device, when the engine is stopped in a predetermined operating state and running,
The second hydraulic pump is driven by the pump driving electric motor, and the shift control is performed using the hydraulic pressure obtained from the second hydraulic pump so that the speed ratio of the continuously variable transmission becomes a value corresponding to the operation state at that time. Further, when there is a large shift request that cannot be handled by the shift control based on the hydraulic pressure obtained from the second pump, the engine is started to drive the first hydraulic pump, and the hydraulic pressure obtained from the first hydraulic pump is shifted. Used for control.

[0010] The control device is provided with a discriminating means for comparing a required shifting speed required in accordance with the operation state with a maximum shifting speed obtained by the hydraulic pressure supplied from the second hydraulic pump. When it is determined that the required shift speed is higher than the maximum shift speed, the engine may be started to drive the first hydraulic pump. For example, see the engine stop permission release determination process control shown in FIG.

With the control device according to the present invention, when a rapid shift request is generated by a sudden braking operation or the like while the engine is temporarily stopped and the vehicle is running, the engine is restarted and the first hydraulic pump is started. The hydraulic pressure is also used for the shift control, so that even if the second hydraulic pump is downsized, it is possible to respond to a rapid shift request. Thus, not only can the second hydraulic pump be reduced in size and weight, but also the electric motor that drives the second hydraulic pump can be reduced in size and its power consumption can be suppressed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a power transmission device for a hybrid vehicle according to the present invention. This device is provided with an engine E that is used for normal traveling drive and can be temporarily stopped. A vacuum tank 6 is provided to store the negative pressure by taking in the intake negative pressure from the intake pipe 5 of the engine E. The negative pressure of the vacuum tank 6 is supplied to the brake booster 8 to operate the brake pedal 8. The brake is activated by boosting the force.

On the output shaft Es of the engine E, a first motor generator 1 is provided.
As a result, start driving of the engine E, assist in driving the engine at the time of starting, and the like are performed, and energy regeneration is performed by using the generator as a generator during deceleration. The output shaft Es of the engine E is connected to the forward / reverse switching mechanism 10 via the damper mechanism 2. A first hydraulic pump 3 is provided on the engine output shaft Es, and the first hydraulic pump 3 is driven by the engine E.

The forward / reverse switching mechanism 10 rotatably supports a sun gear 11 connected to the engine output shaft Es via a damper mechanism 2 and a pinion gear disposed around the sun gear 11 in mesh therewith. And a ring gear 1 meshed with a pinion gear and rotatably disposed coaxially with the sun gear 11 and connected to a transmission input shaft 21.
3 and a forward clutch 14 which engages and disengages the carrier 12 and the sun gear 11 (or the engine output shaft Es), and a reverse brake 15 which can fix and hold the carrier 12. . Therefore, when the forward clutch 14 is engaged, the entire planetary gear rotates the same as the engine output shaft Es, and the transmission input shaft 21 is driven to rotate forward. On the other hand, when the reverse brake 15 is engaged, the ring gear 13 is rotated in the opposite direction to the engine output shaft Es, and the transmission input shaft 21 is driven to rotate in the reverse direction. When both the forward clutch 14 and the reverse brake 15 are released, the engine output shaft E
s and the transmission input shaft 21 are disconnected.

A metal V-belt type continuously variable transmission mechanism 20 having the transmission input shaft 21 is constituted. The rotation of the transmission input shaft 21 which is rotationally driven as described above is steplessly controlled by the continuously variable transmission mechanism 20. And transmitted to the transmission output shaft 27. The continuously variable transmission mechanism 20 includes a drive-side hydraulic cylinder 23
A drive pulley 22 capable of variably adjusting the pulley width,
The drive pulley 22 is composed of a driven pulley 25 variably adjustable by a driven hydraulic cylinder 26 and a metal V-belt 24 hung between the pulleys 22, 25. The drive pulley 22 is connected to the transmission input shaft 21, Pulley 25 is connected to transmission output shaft 27. Therefore, the drive and driven side hydraulic cylinders 23, 26
The transmission input shaft 2 is controlled by controlling the hydraulic pressure supplied to the transmission.
The speed of one rotation can be continuously changed and transmitted to the transmission output shaft 27.

A start clutch 30 is connected to the transmission output shaft 27. The starting clutch 30 is composed of a hydraulically operated clutch, and the starting clutch 3 is controlled by operating hydraulic pressure.
0 engagement control is performed. An idler shaft 31 connected to the transmission input shaft 27 via a starting clutch 30 is rotatably disposed. A final drive gear 32 connected to the idler shaft 31 is provided with a final driven gear 33 having a differential mechanism 34 therein. Are engaged. The differential mechanism 34 is connected to left and right wheels 36 via left and right axle shafts 34 (only the right side is shown in the drawing).

On the other hand, a motor-side driven gear 38 is provided on the idler shaft 31 and is engaged with a motor-side drive gear 37 provided on a rotary shaft of the second motor generator 50. Therefore, the idler shaft 31 is driven by the second motor generator 50.
The left and right wheels 36 can be driven from the motor, and conversely, these can be used as a generator, and can be regenerated by receiving the driving force of the wheels 36 and rotating.

First and second motor generators 3, 5
0 is the battery 5 via the power drive unit 52
Connected to 1. Thus, power is supplied from the battery 51 to drive the motor generators 3 and 50, and the battery is charged with electric power obtained by acting as a generator when the motor generators 3 and 50 are driven to rotate. (That is, perform energy regeneration).

An electric motor 55 for driving a pump is also connected to the power drive unit 52, and a second hydraulic pump 56 is connected to a rotary drive shaft of the electric motor 55 for driving the pump. Therefore, the second hydraulic pump 56 can be driven by driving the pump driving electric motor 55 with the electric power from the battery 51.

In the power transmission device configured as described above, the output of the engine E or the output of the first motor generator 1 is transmitted to the continuously variable transmission mechanism 20 via the forward / reverse switching mechanism 10, and the speed is changed here. After, starting clutch 3
0, transmission control is performed, and further transmitted to the left and right wheels 36 via the differential mechanism 34 and the like.
Thus, the vehicle is driven by the engine E or the first motor generator 1. When the first motor generator 1 is rotationally driven by the wheels 36 as in the case of decelerating traveling or the like, this acts as a generator to perform energy regeneration. On the other hand, the output of the second motor generator 50 is transmitted from the idler shaft 31 to the left and right wheels 36 via the differential mechanism 34 and the like. Also in this case, when the second motor generator 50 is rotationally driven by the wheels 36, this acts as a generator to perform energy regeneration.

As can be seen from the above configuration, the forward clutch 14 and the reverse brake 1
5, the drive and driven pulleys 2 are driven by the drive side and driven side hydraulic cylinders 23 and 26.
Speed control by adjusting the width of the pulleys 2 and 25 and engagement control of the starting clutch 30 are required. For these controls, etc.
First rotation sensor 41 for detecting rotation of transmission input shaft 21 (drive pulley 22), second rotation sensor 42 for detecting rotation of transmission output shaft 27 (driven pulley 25), and rotation of final driven gear 33 (ie, vehicle speed) )
Is provided.

These controls are performed using the hydraulic pressure supplied from the first hydraulic pump 3 or the second hydraulic pump 56. The configuration of the hydraulic control device that performs this control will be described below with reference to the hydraulic circuit diagrams of FIGS. 2 to 4 and the schematic diagram of the hydraulic circuit of FIG. In these figures, the oil passages indicated by circles A to I are connected to each other.

This hydraulic control device has a first hydraulic pump 3 and a second hydraulic pump 56 for discharging hydraulic oil in an oil tank 60 formed by a transmission housing and the like. As described above, the first hydraulic pump 3 is driven by the engine E, and the second hydraulic pump 56 is driven by the electric motor 55 for driving the pump. Note that a relief valve 57 and a one-way valve 58 are provided in the discharge oil passage of the second hydraulic pump 56 driven by the electric motor 55 for driving the pump. The discharge oil from both hydraulic pumps 3 and 56 is regulated by a high-pressure regulator valve 61 to create a high-pressure control oil pressure, which is supplied to a shift valve 65 and a low-pressure regulator valve 64. Further, a low-pressure control oil pressure adjusted by the low-pressure regulator valve 64 is also supplied to the shift valve 65.

The high-pressure regulator valve 61 generates high-pressure control oil pressure according to the back pressure from the high-pressure control valve 62, and the high-pressure control valve 62 and the low-pressure regulator valve 64 are operated and controlled by the control oil pressure from the high-low pressure control valve 63. The high / low pressure control valve 63 generates an arbitrary control oil pressure according to the control current by the linear solenoid 63a. As can be understood from this, the signal current control of the high / low pressure control valve 63 to the linear solenoid 63a causes the high / low pressure control valve 63 The low pressure control oil pressure is set.

The shift valve 65 distributes and supplies the high-pressure control oil pressure and the low-pressure control oil pressure supplied as described above to the drive and driven hydraulic cylinders 23 and 26 to adjust the width of the drive and driven pulleys 22 and 25. Gear shift control. The operation of the shift valve 65 is controlled by shift control oil from a shift control valve 66 operated by a linear solenoid 66a. That is, the linear solenoid 66
By performing the signal current control for a, the shift control can be performed by controlling the operation of the shift valve 65.

The high-pressure control oil pressure generated by the high-pressure control valve 61 is supplied from the oil passage 101 to the clutch reducing valve 72 to generate a line pressure. This line pressure is supplied to the oil passage 102. The surplus oil discharged from the high-pressure regulator valve 61, the high-pressure control valve 62, and the clutch reducing valve 72 is regulated by the lubrication valve 71 and supplied to the lubrication unit LUBE. The line pressure in the oil passage 102 is supplied from the oil passage 103 to the high / low pressure control valve 63 and the shift control valve 66, and further from the oil passage 104 to a starting clutch control valve 75 described later.

The line pressure of the oil passage 102 is supplied to the high pressure control solenoid valve 82 via an oil passage 105 and to the high pressure control valve 62 via an oil passage 105a. Therefore, the high pressure control valve 62 is controlled by the high pressure control solenoid valve 82.
, The line pressure supply switching control is performed, and the high pressure control oil pressure can be switched and set in two stages.

The line pressure of the oil passage 102 is
6, the oil is supplied to the oil passage 107 through the forward / reverse clutch control valve 73, and is selectively supplied to the forward clutch 14 and the reverse brake 15 via the manual valve 74. When the forward / reverse clutch control valve 73 receives a line pressure from the oil passage 108a at the right end, the spool is moved left as shown in FIG.
6 and the oil passage 107, and when the line pressure disappears, the spool is moved to the right so that the oil passage
7 and the oil passage 107 is communicated with the drain. The effect of the line pressure on the oil passage 108a is as follows.
It is controlled by a forward / reverse clutch control solenoid valve 81 that is connected from 02 through an oil passage 108.

The manual valve 74 is switched in response to the operation of a shift lever in the driver's seat. In the P and N ranges, the manual valve 74 closes the oil passage 107 and connects the forward clutch 14 and the reverse brake 15 together with the drain. The clutch 14 and the reverse brake 15 are released.
In the R range, the oil passage 107 communicates with the reverse brake 15 to supply the line pressure to the reverse brake 15 and engage the same. Also, the forward range, ie, D,
In the S and L ranges, the oil passage 107 and the forward clutch 14
To supply the line pressure to the forward clutch and engage it. However, when the oil passage 106 and the oil passage 107 are in communication with each other by receiving the line pressure from the oil passage 108a to the right end of the forward-reverse clutch control valve 73, the engagement of the forward clutch 14 or the reverse brake 15 When the line pressure is not applied to the oil passage 108a, the oil passage 107 communicates with the drain through the forward / reverse clutch control valve 73, and the forward clutch 1
4 and the reverse brake 15 are released regardless of the operating position of the manual valve 74.

As described above, the operation of the starting clutch control valve 75 to which the line pressure is supplied via the oil passage 104 is controlled by the linear solenoid 75a, and the starting clutch control oil pressure is applied to the starting clutch 30 via the shift inhibitor valve 77. Then, the engagement control of the starting clutch 30 is performed. Note that the right end of the shift inhibitor valve 77 is connected to the shift control valve 66 via an oil passage 110. For example, when a device error occurs,
When the supply of drive power is stopped, the current supplied to the linear solenoid 66a of the shift control valve 66 becomes zero, and the shift control oil pressure supplied to the oil passage 110 is maximized.

When the maximum control oil pressure is supplied to the shift inhibitor valve 77 through the oil passage 110, the spool is moved leftward to start the clutch control valve 75.
The supply of the control hydraulic pressure is interrupted, and the pitot pressure is supplied from the pitot control valve 78 to the starting clutch 30 instead. That is, in this case, the engagement control of the starting clutch 30 is performed by the pitot pressure. The maximum control oil pressure is also supplied to the shift valve 65, and the spool is moved to the right to supply the low-pressure control oil pressure to the driven-side hydraulic cylinder 26 and the high-pressure control oil pressure to the drive-side hydraulic cylinder 23. To TOP.

Next, each control in the power transmission device of the hybrid vehicle configured as described above will be described. In this power transmission device, basically, the driving force of the engine E is shifted through a forward / reverse switching mechanism 10 and a continuously variable transmission mechanism 20, and a final drive and driven gears 32, 33, a differential mechanism, The driving force is transmitted to the wheels via the axle shaft 35 and the like to drive the vehicle. However, at the time of starting, the first motor generator 1 assists driving, and at the time of deceleration, the first motor generator 1 acts as a generator to perform energy regeneration (charging of the battery 51).

Further, when the vehicle is stopped or when the vehicle is running at a relatively high speed, the engine E
Is temporarily stopped to improve fuel efficiency. Here, when the engine is temporarily stopped during running of the vehicle, control is performed to drive the second motor generator 50 to drive the wheels 36 to continue running. At this time, both the forward clutch 14 and the reverse brake 15 are released to prevent the forward / reverse switching mechanism 10 from generating drag torque on the engine side. On the other hand, the starting clutch 30 is in a weakly engaged state in which the torque is transmitted as much as necessary to drive the continuously variable transmission mechanism 20 without load. And, control is performed to set the gear ratio of the continuously variable transmission mechanism 20 to a value corresponding to the operating state at that time by performing hydraulic pressure supply control to the driven hydraulic cylinders 23 and 26.

The details of the above-described running drive control will be described below with reference to FIGS. First,
FIG. 6 shows an engine operation processing control flow S10 for determining whether to continue or temporarily stop the operation of the engine. In this control, it is determined in step S11 whether or not the ignition switch is on, and when the ignition switch is off, the engine is stopped (step S2).
2). When the ignition switch is turned on, the process proceeds to steps S12 and S13 to calculate the required driving force F _RQ required by the driver, and at that time the maximum motor driving force F _EV which is the maximum driving force that the second motor generator 50 can output. Is calculated.

In calculating the required driving force F _RQ , first,
It is determined whether or not the travel lever is in the travel range. If the travel lever is not in the travel range, the required driving force F _RQ = 0 is set. On the other hand, when the vehicle is in the traveling range, the required driving force _FRQ is obtained according to the vehicle speed V and the accelerator pedal opening AP (%). Therefore, as shown in FIG. 7, the vehicle speed V and the accelerator opening AP
(%), The required driving force F _RQ is previously determined and set, and the required driving force F _RQ corresponding to the actual vehicle speed V and accelerator opening AP (accelerator pedal depression amount) at that time is shown in FIG. Read from and set. As can be seen from FIG. 7, the required driving force _FRQ decreases as the vehicle speed V increases, and increases as the accelerator opening AP increases. In this figure, the accelerator opening AP = 100% means a state of the accelerator fully open (WOT), and the accelerator opening AP = 0% means a state of the accelerator fully closed.

The maximum motor driving force F _EV is obtained from the remaining capacity SOC of the battery 51 and the vehicle speed V. For this reason, as shown in FIG.
Maximum motor driving force F _EV is set previously obtained, sets reads the maximum motor driving force F _EV corresponding to the actual vehicle speed V and the battery residual capacity SOC at that time from FIG. 8 in accordance with the. As can be seen from FIG. 8, the maximum motor driving force F _EV decreases as the vehicle speed V increases.
The larger the remaining battery charge SOC is, the larger it is.

Next, in step S14, the required driving force F _RQ and the maximum motor driving force F _EV calculated in this manner are calculated.
When F _EV <F _RQ , the engine operation control is selected, and the engine operation process control is performed (step S1).
8, S19). That is, since the required driving force F _RQ sufficient driving can not be performed by the second motor-generator 50 when the maximum motor driving force FEV larger, causing the driving by the engine E.

Conversely, when F _EV ≧ F _RQ , driving and driving by the second motor generator 50 is possible, and it is determined in step S15 whether the engine can be temporarily stopped. Further, in step S16, it is determined whether or not the temporary suspension of the engine is to be released from the permitted state, that is, whether or not the engine should be restarted. If the engine suspension is not permitted or the engine suspension permission is released, the process proceeds from step S17 to steps S18 and S19, and the processing control during engine operation is performed as described above. On the other hand, if the engine can be temporarily stopped, steps S20, S21
To stop the engine and perform engine stop processing.

In the above control flow, step S1
The processing control during engine operation in 9 is control that has been performed conventionally. For example, in the forward range, the vehicle is started by engaging the forward clutch 14 and controlling the engagement of the starting clutch 30 to start the vehicle. Shift control by the continuously variable transmission mechanism 20 is performed according to the driving state to control the vehicle to travel. Since this control is a control generally performed conventionally, the description of the content is omitted here.

The control for temporarily stopping the engine will be described below. First, the engine stop permission determination control S15 in the engine operation processing flow S10 will be described.
Will be described with reference to FIG. In this control flow, first, it is determined whether or not the remaining battery charge SOC is equal to or more than a predetermined value. When the remaining battery charge SOC is less than the predetermined value, that is, when the remaining battery charge is small, the process proceeds to step S35 and the engine stop control is not performed. When the engine is stopped, the power for restarting and the power for driving the auxiliary equipment while the engine is stopped are required at a minimum, and the above-described predetermined value determines whether or not such power is available. This is a value for judgment.
This value changes according to the assumed engine stop time, and is set, for example, to about 100 Wh. On the other hand, if the remaining capacity is equal to or more than the predetermined value, the process proceeds to step S32, and it is determined whether the brake negative pressure (that is, the negative pressure in the vacuum tank 6 shown in FIG. 1) is equal to or less than a predetermined value.

In step S32, when it is determined that the brake negative pressure exceeds a predetermined value (that is, when it is determined that the brake negative pressure is insufficient), a sufficient boosting effect cannot be obtained by the brake booster 7 and safety is obtained. Since there is a possibility that the braking may not be performed, the process proceeds to step S35, and the engine operation is continued without performing the engine stop control to accumulate the brake negative pressure. Note that the predetermined value changes according to the capacity of the vacuum tank 6, for example, 250 m
It is set to about mHg. If the brake negative pressure is equal to or less than the predetermined value and a sufficient boosting action is obtained by the brake booster 7, the process proceeds to step S33, and it is determined whether the warm-up operation of the engine has been completed.

If the warm-up operation has not been completed, priority is given to completing the warm-up of the engine first, and step S3
Proceed to 5 to continue the engine operation without performing the engine stop control. On the other hand, when the warm-up operation is completed, the process proceeds to step S34, and the stop of the engine is permitted. in this way,
The engine stop is permitted only when the remaining battery capacity is sufficient, the brake negative pressure is sufficiently stored, and the warm-up operation is completed.

Next, the engine operation processing flow S10
Will be described with reference to FIG. In this control flow, first, it is determined whether or not the engine stop permission has been issued in step S90. If the stop permission has not been issued, the process of canceling this is unnecessary, and the current flow is terminated as it is. . If the engine stop permission has been issued, the process proceeds to steps S91 and S92 to detect the vehicle speed V and calculate the acceleration dV / dt. And
It is determined whether the acceleration dV / dt calculated in this way is a negative value, that is, whether the vehicle is in a decelerating state (step S93). In this case, no abrupt change in the gear ratio can occur, so that even if an engine stop permission has been issued, there is no need to perform a process of canceling the permission, and the current flow is terminated as it is.

On the other hand, if it is determined that the acceleration dV / dt is a negative value, that is, it is determined that the vehicle is in a decelerating state, step S is executed.
Proceeding to 94, it is determined whether the vehicle speed V is greater than the predetermined vehicle speed V0. The predetermined vehicle speed V0 is the minimum speed at which the rotation of the driven pulley 25 can be detected by the second rotation sensor 42 when the vehicle travels at the predetermined vehicle speed V0, and is specifically about 5 km / h. When the vehicle speed V becomes equal to or lower than the predetermined vehicle speed V0, the rotation of the driven pulley 25 is too small to perform quick shift control, so that if V ≦ V0, the current flow is terminated.

On the other hand, if V> V0, step S9
At 5, the required deceleration time Tv is calculated. The required deceleration time Tv is a time required to reduce the vehicle speed V to the predetermined vehicle speed V0 while maintaining the current deceleration (negative acceleration), and is expressed by Tv = (V0−V) / (dV / dt). Is calculated.

Then, the process proceeds to a step S96, wherein the second hydraulic pump 56 driven by the electric motor 55 for driving the pump is used.
At the maximum shift speed achievable using the hydraulic pressure obtained from
The maximum deceleration time Tr required for shifting from the current gear ratio RA to the predetermined gear ratio RO is searched. Here, the predetermined speed ratio RO is the lowest (LOW side) speed ratio capable of exhibiting a sufficient driving force when the vehicle starts from the vehicle stopped state, and is about 90 times the maximum speed ratio (LOW) of the continuously variable transmission mechanism 20.
% Is set. That is, a speed ratio close to the LOW speed ratio is set as the predetermined speed ratio RO. As can be seen from this, from the current gear ratio RA to the gear ratio RO at which a sufficient starting drive force can be exerted, the shortest gear shift time achievable by the hydraulic pressure from the second hydraulic pump 56 is the maximum deceleration time Tr. As shown in FIG. 11, the maximum deceleration time Tr is experimentally determined in advance in correspondence with the transmission oil temperature to and the current gear ratio RA, and is determined by searching from this graph.

Next, the required deceleration time Tv obtained as described above is compared with the maximum deceleration time Tr (step S9).
7) When Tv ≧ Tr, the engine stop permission control is maintained, and when Tv <Tr, the engine stop permission is released, that is, the engine is restarted (step S98). As can be seen from this, the required deceleration time Tv is a value corresponding to the "requested shift speed required according to the operating state" defined in the claims, and the maximum deceleration time is "the second hydraulic pump". Corresponding to the "maximum shift speed obtained by the hydraulic pressure supplied from the controller".

This control will be specifically described with reference to FIG. First, FIG. 12A shows a time change of the speed ratio when the vehicle is shifted to the LOW side at the maximum speed that can be achieved by the hydraulic pressure from the second hydraulic pump 56 while traveling at the current speed ratio RA. The vertical axis is the gear ratio RATIO
And the horizontal axis represents time t. As you can see from this figure,
The shift time at this time is the maximum deceleration time Tr. FIG.
(B) and (C) show the relationship between the deceleration dV / dt and the required deceleration time Tv required to decelerate to the predetermined vehicle speed V0 at the time of deceleration when a brake operation or the like is performed. Shows the relationship.

FIG. 12B shows a case where the deceleration dV / dt is relatively small, and FIG. 12C shows a case where the deceleration dV / dt is large. In the case of the deceleration shown in FIG. 12B, the required deceleration time Tv is longer than the maximum deceleration time Tr because the deceleration is relatively gradual, and the vehicle is still running when the speed ratio is shifted to the predetermined speed ratio RO. Inside. In this case, the speed ratio is shifted to the predetermined speed ratio RO while the vehicle is running and the speed control is possible. Therefore, even if the vehicle is stopped with the engine stop permitted, the predetermined speed ratio RO required for the next start is obtained.
And the engine stop permission is maintained.

On the other hand, in the case of the deceleration shown in FIG. 12C, the required deceleration time Tv is shorter than the maximum deceleration time Tr, and the vehicle has already stopped when the speed ratio is shifted to the predetermined speed ratio RO. In this case, even when the vehicle stops and the gearshift control becomes impossible, the gear ratio is maintained at the predetermined gear ratio RO.
Since the gear has not been shifted, control to release the permission to stop the engine is performed. As a result, when deceleration is started in the state of the gear ratio RA, the engine is restarted, the first hydraulic pump 3 is driven, rapid shift control is performed using the discharged hydraulic pressure, and before the vehicle stops. Then, a predetermined speed ratio RO required for the next start is obtained. As can be seen from this, if the capacity of the first hydraulic pump 3 driven by the engine is made sufficiently large, the electric motor 55
Even if the second hydraulic pump 56 driven by the above is made small and compact, the shift control without any problem can be performed.

The engine stop processing control (step S) performed when the engine stop is permitted as described above.
The contents of 20) will be described with reference to FIG. In this control, first, the inhibitor solenoid valve, that is, the clutch control solenoid valve 81 (see FIG. 3) is driven (step S41). The clutch control solenoid valve 81 is a normally closed type solenoid valve. By driving the clutch control solenoid valve 81, the oil passages 108 and 108a are communicated with the drain, and the operating oil pressure to the right ends of the forward and backward clutch control valve 73 is reduced to zero. As a result, as described above, the oil passage 107 communicates with the drain, and the line pressure to the forward clutch 14 or the reverse brake 15 performed via the manual valve 74 is cut off. Both are released.

As a result, the engine output shaft Es and the transmission input shaft 21 are separated from each other by the forward / reverse switching mechanism 10, and the transmission-side rotation is not transmitted from the transmission input shaft 21 to the engine. The generation of drag torque on the side is prevented. That is, the engine E
Is temporarily stopped and the vehicle travels while driving the wheels 36 by the second motor generator 50, the rotation is separated by the forward / reverse switching mechanism 10 and is not transmitted to the engine side. No drag torque is generated by the rotating member therebetween, and the driving force of the second motor generator 50 is efficiently transmitted to the wheels 36.
Therefore, the driving power of the battery 51 is not wasted, and efficient energy regeneration can be performed when the second motor generator 50 is driven by driving from the wheels 36 during deceleration or the like.

Next, the target speed ratio RT during the period when the engine is temporarily stopped is calculated (step S42). As shown in FIG. 14, the target gear ratio RT is determined in accordance with the vehicle speed V and the accelerator opening (accelerator pedal depression amount) AP, and decreases as the vehicle speed V increases and increases as the accelerator opening increases. Is set. Specifically, when the driver gradually depresses the accelerator pedal to increase the required driving force and restart the engine, the target gear ratio immediately before restarting the engine is determined by restarting the engine and starting. The rotation of the engine E is set to be approximately 2000 rpm when the clutch 30 is engaged. On the other hand, when the depression amount of the accelerator pedal is relatively small and the required driving force is not large, the rotation of the engine E is set to be approximately 1200 to 1500 rpm when the engine is restarted and the starting clutch 30 is engaged. You.

When the target gear ratio is calculated in step S42 in this way, it is determined whether or not it is necessary to drive the second hydraulic pump (electric oil pump) 56 based on the target gear ratio (step S42). S43). FIG. 15 shows the content of this determination control. Here, it is determined whether the timer has expired (step S51).
In the initial state, the timer is in an end state.
If the timer has expired, the process proceeds to step S52 to calculate an actual gear ratio RA (= NDR / NDN). Here, NDR is the rotation speed of the drive pulley 22 detected by the first rotation sensor 41, and NDN is the rotation speed of the driven pulley 25 detected by the second rotation sensor 42.

Next, the routine proceeds to step S53, where a gear ratio deviation RE (= RT-RA) is calculated. When the absolute value of the speed ratio deviation RE is larger than a predetermined value, that is, when the speed ratio deviation RE is large, the shift control is necessary, and the second hydraulic pump 56 is driven by the pump driving electric motor 55.
At this time, a timer is set in step S55, and once the second hydraulic pump 56 is driven, it is continuously driven for the time set by the timer. In this way, by using the timer, the frequency of turning on and off the electric motor 55 for driving the pump is reduced, and the durability of the switch element (relay) for performing on / off control is improved. On the other hand, when the absolute value of the gear ratio deviation RE is smaller than the predetermined value, there is no need for gear shifting, and the second hydraulic pump 56
Is stopped (step S57).

As described above, in step S43, the drive of the electric oil pump, that is, the second hydraulic pump 56 is determined, and when it is driven, the process proceeds from step S44 to step S45 to control the starting clutch process. FIG. 16 shows the contents of this control. In this control, first, the transmission oil temperature to is detected (step S61). Next, the start clutch engagement torque Tc is calculated, and a command signal for setting a hydraulic pressure to be supplied to the start clutch 30 to obtain the engagement torque Tc is output to control the operation of the start clutch control valve 75. The starting clutch engagement torque Tc is determined according to the transmission oil temperature to and the vehicle speed V.
It is set as shown in FIG. When the vehicle is running with the engine stopped, the continuously variable transmission mechanism 2 is controlled so that a gear ratio corresponding to the running state (operating state) at this time is obtained.
It is necessary to rotate 0 without load. The starting clutch engagement torque Tc is a torque value required to transmit the driving force necessary for causing the continuously variable transmission mechanism 20 to rotate at no load as described above. The lower the oil temperature to is, the higher the vehicle speed V is. The larger torque Tc is set as shown in FIG.

Next, from step S45 to step S46
To perform a pulley speed change process, that is, a speed change process control in the continuously variable transmission mechanism 20. FIG. 18 shows the contents of this control. First, in this control, it is determined whether the speed ratio deviation RE is positive or negative (step S71). Gear ratio deviation RE
Is negative and the actual gear ratio RA is larger than the target gear ratio RT, the gear ratio is reduced (to the OD (overdrive) side).
Conversely, when the speed ratio deviation RE is positive and the actual speed ratio RA is smaller than the target speed ratio RT, it is necessary to increase the speed ratio (to the LOW side).

Therefore, if the speed ratio deviation RE is negative, the process proceeds to step S72, where the speed ratio deviation RE is compared with a first predetermined value which is a negative value and whose absolute value is relatively small. If the gear ratio deviation RE is larger than the first predetermined value (close to zero), it is determined that there is no need for gear shifting, and the previous gear command value is held (step S76). Gear ratio deviation R
When E is smaller than the first predetermined value (when the absolute value is a larger negative value), the process proceeds to step S73, and the speed ratio and the second predetermined value that is a negative value and the absolute value is relatively large. Compare with the deviation RE. If the speed ratio deviation RE is larger than the second predetermined value (close to zero), it is determined that a gentle shift to the OD side is necessary, and an OD-side slow shift command value is set as the shift command value (step S75). . On the other hand, the gear ratio deviation R
When E is smaller than the second predetermined value (when the absolute value is a larger negative value), it is determined that rapid shifting to the OD side is necessary, and the OD-side rapid shifting command value is set as the shifting command value. (Step S74).

On the other hand, if it is determined in step S71 that the gear ratio deviation is a positive value, step S77 is executed.
Then, the speed ratio deviation RE is compared with a third predetermined value which is a positive value and whose absolute value is relatively small. Gear ratio deviation R
If E is smaller than the third predetermined value (close to zero), it is determined that there is no need for shifting, and the previous shift command value is held (step S79). If the speed ratio deviation RE is larger than the third predetermined value, the process proceeds to step S78, and the speed ratio deviation RE is compared with a fourth predetermined value which is a positive value and whose absolute value is relatively large. If the speed ratio deviation RE is smaller than the fourth predetermined value, it is determined that a gradual shift to the LOW side is necessary, and a LOW-side slow shift command value is set as the shift command value (step S80). On the other hand, if the speed ratio deviation RE is greater than the fourth predetermined value, it is determined that a rapid shift to the LOW side is necessary, and a LOW-side rapid shift command value is set as the shift command value (step S81).

The operation of the shift control valve 66 is controlled based on the shift command value set in this way, and the control of the drive by the shift valve 65 and the supply of the high and low pressure control hydraulic pressures to the driven hydraulic cylinders 23 and 26 are controlled. The shift control corresponding to the shift command value is performed.

The above description has been made on various control contents when the engine is temporarily stopped. This control is particularly effective when the engine is temporarily stopped.
4 and the reverse brake 15 are released to disconnect the connection with the engine side, and the driving of the second hydraulic pump 56 by the pump driving electric motor 55 is limited when the speed ratio deviation becomes large. When the deviation becomes large, the start clutch 30 is weakly engaged and the continuously variable transmission 2
0 is a no-load rotation drive, and a shift control is performed such that a target gear ratio corresponding to the operation state at that time is obtained.

Thus, when the engine is temporarily stopped and the second motor generator 50 is driven to travel, no rotational drag torque is generated on the engine side by the forward / reverse switching mechanism 10, and the driving efficiency of the second motor generator 50 is reduced. Also, the energy regeneration efficiency when this is driven from the wheels and acts as a generator is improved.
Further, during the driving by the second motor generator 50, the shift control of the continuously variable transmission mechanism is unnecessary, but during this time, the engine was restarted in order to perform the shift control so as to obtain the speed ratio corresponding to the operating state. Sometimes, it is possible to smoothly shift to the engine drive control without increasing the engine rotation. In addition, such a continuously variable transmission mechanism 2
At the time of the zero-speed shift control, the continuously variable transmission mechanism 20 only performs the shift control in the no-load operation state, so that there is an advantage that the shift hydraulic pressure may be low and the shift control energy may be small. Similarly, the starting clutch 30 is connected to the continuously variable transmission mechanism 20.
It is only necessary to make a weak engagement that transmits only a small torque necessary for causing the start clutch 30 to rotate at no load.
May be small.

In the above description, the power transmission device using the metal V-belt type continuously variable transmission mechanism has been described as an example, but the continuously variable transmission mechanism is not limited to this type. Further, when the engine is temporarily stopped, the engine side and the continuously variable transmission mechanism side are separated from each other by the forward / reverse switching mechanism. However, another clutch is arranged on the input shaft of the continuously variable transmission mechanism, and this clutch constitutes a disengagement control means according to the present invention. May be configured to be released.

[0064]

As described above, according to the present invention,
When the engine is stopped and running in a predetermined operating state, the second hydraulic pump is driven by the electric motor for driving the pump, and the speed ratio of the continuously variable transmission is adjusted using the hydraulic pressure obtained from the second hydraulic pump. The shift control is performed so as to be a value corresponding to the operating state at the time of the operation, and when a large shift request that cannot be handled by the shift control by the hydraulic pressure obtained from the second pump occurs, the engine is started and the first hydraulic pump is started. Since the control device is configured to be driven and to use the hydraulic pressure obtained from the first hydraulic pump for speed change control, a rapid speed change request is generated due to a sudden braking operation or the like while the vehicle is running with the engine temporarily stopped. At times, the engine is restarted and the hydraulic pressure from the first hydraulic pump is also used for shift control, so that even if the second hydraulic pump is downsized, it is possible to respond to a rapid shift request. As a result, the second hydraulic pump can be reduced in size and size.
Not only can the weight be reduced, but also the electric motor for driving the second hydraulic pump can be reduced in size and its power consumption can be suppressed.

A discriminating means is provided for comparing the required shifting speed required in accordance with the operating state with the maximum shifting speed obtained by the hydraulic pressure supplied from the second hydraulic pump. When it is determined that the speed is higher than the shift speed, the engine may be started to drive the first hydraulic pump.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a power transmission device for a hybrid vehicle according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing a device configuration for performing operation control in the power transmission device.

FIG. 3 is a hydraulic circuit diagram showing a device configuration for performing operation control in the power transmission device.

FIG. 4 is a hydraulic circuit diagram showing a device configuration for performing operation control in the power transmission device.

FIG. 5 is a schematic diagram of a hydraulic circuit showing a device configuration for performing operation control in the power transmission device.

FIG. 6 is a flowchart showing the content of traveling drive control in the power transmission device.

FIG. 7 shows a required driving force F _RQ used for the traveling drive control.
6 is a graph showing the relationship between vehicle speed V and accelerator pedal opening AP.

FIG. 8 shows a maximum motor driving force F in the traveling drive control.
₅ is a graph showing a relationship among _EV , vehicle speed V, and remaining battery charge SOC.

FIG. 9 is a flowchart showing the contents of engine stop permission determination control in the control of FIG. 6;

FIG. 10 is a flowchart showing the contents of engine stop permission release determination processing control in the control of FIG. 6;

FIG. 11 is a graph showing a relationship between a current gear ratio RA, a transmission oil temperature to, and a maximum deceleration time Tr in the engine stop permission cancellation determination process control.

FIG. 12 is a graph showing a relationship between a required deceleration time Tv and a maximum deceleration time Tr when the speed ratio is changed from RA to RO by decelerating traveling.

FIG. 13 is a flowchart showing the contents of engine stop processing control in the control of FIG. 6;

14 is a graph showing a relationship between a target speed ratio RT calculated in the control of FIG. 13, a vehicle speed V, and an accelerator pedal opening AP.

FIG. 15 is a flowchart showing the content of electric oil pump drive determination control in the control of FIG.

FIG. 16 is a flowchart showing the content of start clutch process control in the control of FIG.

17 is a graph showing a relationship between a starting clutch torque Tc calculated in the control of FIG. 16, a vehicle speed V, and a transmission oil temperature to.

FIG. 18 is a flowchart showing the contents of pulley speed change processing control in the control of FIG.

[Explanation of symbols]

 E engine 3 first hydraulic pump 20 metal V-belt type continuously variable transmission mechanism 31 idler shaft (drive power transmission system) 32 final dry gear (drive power transmission system) 33 final driven gear (drive power transmission system) 34 differential mechanism (drive) Power transmission system) 35 Axle shaft (Drive power transmission system) 50 Second motor generator (Electric drive motor) 55 Electric motor for pump drive 56 Second hydraulic pump

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Tamagawa 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Inventor Tetsuya Hasebe 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G093 AA06 AA07 AA15 AA16 BA19 BA21 BA22 CA00 DB00 DB01 DB07 DB23 EB03 FA11 3J552 MA07 MA15 MA26 NB09 PA15 PA59 PA67 QA30C QB07 RB02 RB06 RC01 RC02 SA32. VB01Z VB04Z VB10Z VD02Z

Claims (2)

[Claims] An engine that can be temporarily stopped in a predetermined operating state, a continuously variable transmission that is connected to an output shaft of the engine, and that continuously changes its output rotation; A control device for a hybrid vehicle, comprising: a driving force transmission system that transmits an output to driving wheels; and an electric drive motor that is disposed in parallel with the engine and that can drive the driving wheels. A first hydraulic pump driven by a pump driving electric motor; and a second hydraulic pump driven by a pump driving electric motor. A second hydraulic pump is driven to change the speed ratio of the continuously variable transmission to a value corresponding to the operating state at that time by using the hydraulic pressure obtained from the second hydraulic pump. Performs, the second
The engine is started to drive the first hydraulic pump when a large shift request that cannot be handled by the shift control by the hydraulic pressure obtained from the pump is used, and the hydraulic pressure obtained from the first hydraulic pump is used for the shift control. A control device for a hybrid vehicle, comprising: And a determining means for comparing a required shifting speed required in accordance with an operation state with a maximum shifting speed obtained by a hydraulic pressure supplied from the second hydraulic pump. The control device for a hybrid vehicle according to claim 1, wherein the engine is started to drive the first hydraulic pump when it is determined that the speed is higher than the maximum shift speed.