JP2010149652A - Hydraulic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic control device securing oil pressure even when an electric oil pump is in an abnormal state. <P>SOLUTION: When a clutch is not released although the clutch is controlled to be released, it is determined that a hydraulic circuit is in an abnormal state. When the electric oil pump fails, the number of revolution of a drive motor is increased to a set value or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulic control device.

As this type of technology, the technology described in Patent Document 1 is disclosed. The technique described in this publication starts an engine when an abnormality occurs in an electric oil pump in a hybrid vehicle.
JP-A-2005-207305

  The prior art has a problem that the hydraulic pressure cannot be secured until the start of the engine is completed.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a hydraulic control device capable of ensuring hydraulic pressure even when an abnormality occurs in the electric oil pump. is there.

  In order to achieve the above object, according to the present invention, when the electric oil pump is out of order and the rotational speed of the drive motor is smaller than the set value, the rotational speed of the drive motor is increased to the set value or more. The fastening torque of the starting clutch is controlled to coincide with the target torque.

  Therefore, even when an abnormality occurs in the electric oil pump, the hydraulic pressure can be ensured.

  Hereinafter, the best mode for realizing the hydraulic control device of the present invention will be described based on the first embodiment.

[Example 1]
[Configuration of drive system]
First, the configuration of the vehicle drive system in the first embodiment will be described.
FIG. 1 is an overall system diagram showing a hybrid vehicle by rear wheel drive to which the vehicle control device of the first embodiment is applied. The drive system of this hybrid vehicle includes an engine E, a flywheel FW, a first clutch CL1, a motor generator MG that functions as a drive motor, a mechanical oil pump MOP (mechanical oil pump), and an electric oil pump EOP. , Second clutch CL2 (starting clutch), automatic transmission AT, propeller shaft PS, differential DF, left drive shaft DSL, right drive shaft DSR, left rear wheel RL (drive wheel), right rear And a wheel RR (drive wheel). Note that FL is the left front wheel and FR is the right front wheel.

(engine)
The engine E is a gasoline engine or a diesel engine, and the opening degree of the throttle valve and the like are controlled based on a control command from an engine controller 1 described later. The engine output shaft is provided with a flywheel FW.

(First clutch)
The first clutch CL1 is a fastening element interposed between the engine E and the motor generator MG, and is generated by the first clutch hydraulic unit 6 based on a control command from the first clutch controller 5 described later. The engagement and disengagement are controlled by the control oil pressure (first clutch pressure).

(Motor generator)
The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and the three-phase AC generated by the inverter 3 is generated based on a control command from a motor controller 2 described later. It is controlled by applying. This motor generator MG can also operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (this state is called “powering”), and when the rotor is rotated by an external force, The battery 4 can also be charged by functioning as a generator that generates electromotive force at both ends of the stator coil (this operation state is called “regeneration”). Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

(Second clutch)
The second clutch CL2 is a fastening element (clutch) interposed between the motor generator MG and the left and right rear wheels RL, RR, and based on a control command from the AT controller 7 described later, the second clutch hydraulic unit. The fastening and release are controlled by the control hydraulic pressure generated by the control unit 8. The second clutch CL2 is not newly added as a hybrid vehicle-dedicated clutch, and uses some fastening elements among a plurality of fastening elements fastened at each gear stage of the automatic transmission AT. The second clutch CL2 is a wet multi-plate clutch that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid, but may have other configurations.

(Automatic transmission)
The automatic transmission AT automatically switches the stepped gear ratio such as the fifth forward speed, the first reverse speed, etc. according to the shift map stored in the AT controller 7 in advance according to the vehicle speed VSP, the accelerator pedal opening AP, and the like. It is a transmission. The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR.

(Driving mode)
The drive system of this hybrid vehicle has three travel modes corresponding to the engaged / released state of the first clutch CL1. The first travel mode is an electric vehicle travel mode (hereinafter referred to as “EV travel mode”) as a motor use travel mode in which the first clutch CL1 is disengaged and travels using only the power of the motor generator MG as a power source. The second travel mode is an engine use travel mode (hereinafter referred to as “HEV travel mode”) in which the first clutch CL1 is engaged and the engine E is included in the power source.

  The third travel mode is an engine-use slip travel mode (hereinafter referred to as “WSC (Wet Start Clutch) travel) in which the first clutch CL1 is engaged and the second clutch CL2 is slip-controlled and the engine E is included in the power source. Abbreviated as “mode”). This mode achieves creep running especially when the battery SOC is low or the engine water temperature is low. Furthermore, in this mode, the driving force can be output while starting the engine when starting from the engine stopped state.

  Further, the HEV travel mode has three travel modes of “engine travel mode”, “motor assist travel mode”, and “travel power generation mode”. In the “engine running mode”, the drive wheels are moved using only the engine E as a power source. In the “motor-assisted travel mode”, the drive wheels are moved using the engine E and the motor generator MG as power sources. In the “traveling power generation mode”, the motor generator MG is caused to function as a power generator while the drive wheels RR and RL are moved using the engine E as a power source.

  In the traveling power generation mode, the motor generator MG is operated as a generator using the power of the engine E during constant speed operation or acceleration operation, and the generated power is used for charging the battery 4. During deceleration operation, braking energy is used to operate motor generator MG as a generator to regenerate braking energy.

(Mechanical oil pump)
Mechanical oil pump MOP is provided on the output shaft of motor generator MG, and is driven by motor generator MG in the EV travel mode, and is driven by engine E and motor generator MG in the HEV travel mode. When the mechanical oil pump MOP is driven, the oil stored in the oil pan in the automatic transmission AT is sucked through the oil strainer and supplied to a hydraulic control valve (not shown) provided in the automatic transmission AT.

(Electric oil pump)
The electric oil pump EOP is an oil pump that is driven by an electric motor, and is driven during EV travel mode or idle stop control. When the electric oil pump EOP is driven, the oil stored in the oil pan in the automatic transmission AT is sucked in through the oil strainer as in the case of the mechanical oil pump MOP. Supply to the control valve.

[Configuration of drive system]
Next, the control system of the hybrid vehicle in the first embodiment will be described. The control system of the hybrid vehicle includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, a first clutch hydraulic unit 6, an AT controller 7, a second clutch, in addition to various sensors and switches described later. Hydraulic unit 8, brake controller 9, electric oil pump controller 26, and integrated controller 10 (electric oil pump abnormality detecting means, motor generator rotation speed detecting means, motor generator control means, starting clutch engagement torque control means, abnormality control means) have.

  The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are provided in a hydraulic control valve (not shown) provided in the automatic transmission AT. The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are supplied with the line pressure adjusted in advance in the hydraulic control valve.

  The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, the electric oil pump controller 26, and the integrated controller 10 can exchange information with a CAN communication line 11. Are connected to each other.

  Various sensors and switches include an engine speed sensor 12, a resolver 13, a first clutch hydraulic sensor 14, a stroke sensor 15, an accelerator opening sensor 16, a vehicle speed sensor 17, a second clutch hydraulic sensor 18, an AT oil temperature sensor 7a, wheels. A speed sensor 19, a brake stroke sensor 20, a motor rotation speed sensor 21, a second clutch output rotation speed sensor 22, a brake hydraulic pressure sensor 24, and a battery power sensor 25 are provided.

(Engine controller)
The engine controller 1 gives a command for controlling the engine operating point (Ne, Te) based on information such as the engine speed Ne detected by the engine speed sensor 12 and the target engine torque command Te * from the integrated controller 10, for example. , Output to the throttle valve actuator (not shown). In the engine controller 1, an engine torque estimation unit 1a for estimating the engine torque Te based on the fuel injection amount of the engine E, the throttle opening degree, and the like is provided. Information on the engine speed Ne (the input speed of the first clutch CL1) and the estimated engine torque Te is supplied to the integrated controller 10 via the CAN communication line 11.

(Motor controller)
The motor controller 2 controls the motor operating point (Nm, Tm) of the motor generator MG based on the rotor rotational position of the motor generator MG detected by the resolver 13 and the target motor torque command Tm * from the integrated controller 10. Is output to the inverter 3. In the motor controller 2, there is provided a motor torque estimating unit 2a for estimating the motor torque Tm based on the value of the current flowing through the motor generator MG. Information on the estimated motor torque Tm is supplied to the integrated controller 10 via the CAN communication line 11.

(First clutch controller)
The first clutch controller 5 includes a first clutch pressure detected by the first clutch oil pressure sensor 14, a stroke sensor value C1S detected by the stroke sensor 15, and a first clutch control command (stroke target value C1S *) from the integrated controller 10. Based on the above, a command for controlling engagement / release of the first clutch CL1 (first clutch pressure command value for realizing the stroke target value C1S *) is calculated and output to the first clutch hydraulic unit 6. Information of the detected stroke sensor value C1S is input to the integrated controller 10 via the CAN communication line 11.

(AT controller)
The AT controller 7 includes an accelerator opening AP detected by the accelerator opening sensor 16, a vehicle speed VSP detected by the vehicle speed sensor (AT output speed sensor) 17, a second clutch pressure detected by the second clutch hydraulic sensor 18, and AT oil. Based on the AT oil temperature detected by the temperature sensor 7a and the second clutch control command (second clutch engagement torque target value) from the integrated controller 10, a command for controlling the engagement / release of the second clutch CL2 is issued to the second clutch. Output to the hydraulic unit 8. The second clutch CL2 is set to an engagement torque that is slightly higher than the target torque obtained by multiplying the target torque T * by a safety factor during normal traveling. Here, the target torque T * is the sum of the target engine torque command Te * and the target motor torque Tm *. The accelerator opening AP, the vehicle speed VSP, and the AT oil temperature are input to the integrated controller 10 via the CAN communication line 11.

(Brake controller)
The brake controller 9 performs regenerative cooperative brake control based on the wheel speeds of the four wheels detected by the wheel speed sensor 19, the brake stroke BS detected by the brake stroke sensor 20, and the regenerative cooperative control command from the integrated controller 10. For example, when the brake is depressed, if the regenerative braking force is insufficient for the required braking force calculated from the brake stroke BS, control is performed to compensate for the shortage with mechanical braking force (hydraulic braking force or motor braking force). .

(Electric oil pump controller)
The electric oil pump controller 26 calculates a command for controlling driving / stopping of the electric oil pump EOP based on the electric oil pump control command from the integrated controller 10, and outputs this to the electric oil pump EOP. The electric oil pump EOP is driven at the time of idle stop control in the EV traveling mode or when the vehicle is stopped.

(Integrated controller)
The integrated controller 10 has a function of calculating the target torque T * to be applied to the drive wheels based on the driver's accelerator operation amount, vehicle behavior, etc., managing the energy consumption of the entire vehicle, and running the vehicle with maximum efficiency. is doing. The integrated controller 10 includes a motor rotational speed Nm detected by the motor rotational speed sensor 21, a second clutch output rotational speed N2out detected by the second clutch output rotational speed sensor 22, a brake pressure detected by the brake hydraulic pressure sensor 24, and a battery power sensor. 25, the usable power capacity of the battery 4 (hereinafter referred to as the battery SOC), and each information obtained via the CAN communication line 11, that is, the engine speed Ne (the first clutch CL1 input speed), the stroke sensor Receives inputs such as value C1S, accelerator opening AP, vehicle speed VSP, and brake stroke BS.

[Electric oil pump abnormality processing]
FIG. 2 is a flowchart showing a flow of processing for determining an abnormality in the hydraulic circuit in the integrated controller 10. This process is performed in the EV travel mode and not performed in the HEV travel mode.

In step S1, it is determined whether or not an abnormality has occurred in the electric oil pump EOP. If an abnormality has occurred, the process proceeds to step S2, and if no abnormality has occurred, the process of step S1 is performed. repeat.
In step S2, it is determined whether or not the rotational speed of motor generator MG is smaller than the set value. If the rotational speed is smaller than the set value, the process proceeds to step S3. If the rotational speed is greater than or equal to the set value, step is performed. The process proceeds to S7.

In step S3, it is determined whether or not the vehicle speed is zero (stopped). If the vehicle speed is not zero (running), the process proceeds to step S4. If the vehicle speed is zero, the process proceeds to step S6. .
In step S4, the second clutch CL2 is controlled to be released or in a standby state, and the process proceeds to step S6.
In step S5, the engagement torque of the second clutch CL2 is controlled to coincide with the target torque T *, and the process proceeds to step S6.

In step S6, the number of rotations of motor generator MG is increased to a set value or more, and the process ends.
In step S7, the EV travel mode in the vehicle speed region using the electric oil pump EOP is prohibited, and the process ends.

[Hydraulic circuit abnormality judgment processing operation]
In the HEV travel mode, the engine E is driven, and the engine E is always rotating at a rotational speed equal to or higher than the idle speed, so that the hydraulic pressure higher than the line pressure can be secured by the mechanical oil pump MOP. However, since the engine E is stopped in the EV traveling mode, the mechanical oil pump MOP is driven only by the motor generator MG. Since the motor generator MG is driven at a rotational speed corresponding to the vehicle speed, the rotational speed is not sufficient when traveling at a low vehicle speed, and a hydraulic pressure higher than the line pressure cannot be secured by the mechanical oil pump MOP. Further, since the engine E and the motor generator MG are stopped at the time of idling stop, the mechanical oil pump MOP cannot be driven, so that hydraulic pressure cannot be generated.

  Therefore, the electric oil pump E26 is driven and controlled by the electric oil pump controller 26 at the time of the EV running mode or idling stop. Even when the hydraulic pressure above the line pressure cannot be secured only by the mechanical oil pump MOP, the hydraulic pressure above the line pressure can be secured by driving the electric oil pump EOP.

  When an abnormality occurs in the electric oil pump EOP during the EV travel mode, the process proceeds from step S1 to step S2 in the flowchart of FIG. The set value in step S2 is a value of the rotational speed at which a hydraulic pressure equal to or higher than the line pressure can be secured by the mechanical oil pump MOP. That is, when the rotation speed of the motor generator MG is smaller than the set value, it is determined that the hydraulic pressure higher than the line pressure cannot be secured by the mechanical oil pump MOP, and when the rotation speed of the motor generator MG is higher than the set value, the mechanical oil pump It is determined that the hydraulic pressure above the line pressure can be secured by MOP.

  If it is determined in step S2 that the hydraulic pressure equal to or higher than the line pressure cannot be secured by the mechanical oil pump MOP, finally, in step S6, control is performed to increase the rotational speed of the motor generator MG to a set value or higher. The motor generator MG is torque controlled according to the target torque T *, but in step S6 it is switched to the rotational speed control. Therefore, the output torque of motor generator MG increases with respect to target torque T *.

  Therefore, if it is determined in step S3 that the vehicle is stopped, the second clutch CL2 is released or is set to a standby state in step S4. Here, the standby control is control in which the second clutch CL2 is in a state of being released in a state where it can be immediately engaged. As a result, no torque is transmitted to the drive wheels, so that the vehicle does not suddenly move.

  If it is determined in step S3 that the vehicle is traveling, control is performed so that the engagement torque of the second clutch CL2 matches the target torque T * in step S5. As described above, during normal travel, the engagement torque of the second clutch CL2 is set to a value obtained by multiplying the target torque T * by a safety factor. In step S5, a value that does not multiply this safety factor is used as the engagement torque. Thus, when the output torque of motor generator MG is larger than the engagement torque of second clutch CL2, second clutch CL2 is slip-controlled, and the torque transmitted to the drive wheel side is controlled to target torque T *. Therefore, the vehicle behavior does not fluctuate.

  If it is determined in step S2 that the hydraulic pressure equal to or higher than the line pressure can be secured by the mechanical oil pump MOP, the EV traveling mode in the vehicle speed region using the electric oil pump is prohibited in step S7. That is, when the EV travel mode is selected, the HEV travel mode is selected in a low vehicle speed range where the electric oil pump EOP must be driven.

[Action]
When an abnormality occurs in the electric oil pump EOP in the EV travel mode, the line pressure cannot be secured even if the mechanical oil pump MOP is driven by the motor generator MG, particularly at a low vehicle speed. The line pressure can be secured by starting the engine E and driving the mechanical oil pump MOP, but in this case, the hydraulic pressure cannot be secured until the start of the engine E is completed.

Therefore, when the rotation speed of the motor generator MG is lower than the rotation speed at which the mechanical oil pump MOP can be driven to ensure the line pressure, the rotation speed of the motor generator MG controlled according to the target torque T * is increased. I did it. At this time, since the rotation speed of the motor generator MG increases and the output torque becomes higher than the target torque T *, the second clutch is controlled to coincide with the target torque T * and transmitted to the driving wheel side. Matches the target torque T *.
By adopting this configuration, even if an abnormality occurs in the electric oil pump EOP in EV driving mode, the mechanical oil pump MOP is driven only by the motor generator MG, which has a faster response than the engine E starts, and the line pressure is secured. This makes it possible to suppress fluctuations in the line pressure.

  Further, even if an abnormality occurs in the electric oil pump EOP during the EV travel mode, the mechanical oil pump MOP can be driven only by the motor generator MG and the line pressure can be secured without starting the engine E. Therefore, it is possible to continue traveling in the EV traveling mode (without shifting to the HEV traveling mode), and to improve fuel efficiency.

  Even when the output torque of the motor generator MG is increased by increasing the rotation speed of the motor generator MG, the engagement torque of the second clutch CL2 is equal to the target torque T *, so that the drive wheel side There is no fluctuation in the torque transmitted to the vehicle, and the vehicle behavior can be stabilized.

  Further, the second clutch CL2 is released when the vehicle is stopped. With this configuration, since the torque is not transmitted to the drive wheel side when the vehicle is stopped, the vehicle can be prevented from starting suddenly.

[Effect of Example 1]
The effects of the hydraulic control apparatus according to the present invention, as grasped from the first embodiment, are listed below.

  (1) A motor generator MG that generates power to be applied to the drive wheels, a second clutch CL2 interposed between the motor generator MG and the drive wheels, an electric oil pump EOP driven by the electric motor, and a motor The mechanical oil pump MOP driven by the generator MG, the motor rotation speed sensor 21 for detecting the rotation speed of the motor generator MG, the output torque of the motor generator MG in accordance with the target torque T * in the normal time, and the first When the engagement torque of the two-clutch CL2 is controlled to be higher than the target torque T * and an abnormality has occurred in the electric oil pump EOP, the engagement torque is set to the target torque T when the rotational speed of the motor generator MG is smaller than the set value. * An integrated controller that controls the motor generator MG so that the number of revolutions of the motor generator MG rises above the set value. Provided and La 10.

  Therefore, even if an abnormality occurs in the electric oil pump EOP in the EV travel mode, it becomes possible to secure the line pressure by driving the mechanical oil pump MOP only with the motor generator MG having a quicker response than the engine E is started. Therefore, fluctuations in line pressure can be suppressed.

  Further, even if an abnormality occurs in the electric oil pump EOP during the EV traveling mode, the mechanical oil pump MOP can be driven only by the motor generator MG to ensure the line pressure without starting the engine E. Therefore, it is possible to continue traveling in the EV traveling mode (without shifting to the HEV traveling mode), and to improve fuel efficiency.

  Even when the output torque of the motor generator MG is increased by increasing the rotation speed of the motor generator MG, the engagement torque of the second clutch CL2 is equal to the target torque T *, so that the drive wheel side There is no fluctuation in the torque transmitted to the vehicle, and the vehicle behavior can be stabilized.

(2) The integrated controller 10 releases the second clutch CL2 when the electric oil pump EOP is out of order and the rotational speed of the motor generator MG is smaller than the set value and the vehicle is stopped. To be controlled.
Therefore, since the torque is not transmitted to the driving wheel side when the vehicle is stopped, the vehicle can be prevented from starting suddenly.

[Other embodiments]
The best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to the first embodiment and does not depart from the gist of the present invention. Any change in the design of the range is included in the present invention.

  The hydraulic control apparatus according to the first embodiment may be applied to an electric vehicle that is used in a hybrid vehicle but does not have an engine.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing a rear-wheel drive hybrid vehicle to which a vehicle control device of Embodiment 1 is applied. 3 is a flowchart illustrating a flow of control processing in the integrated controller according to the first embodiment.

Explanation of symbols

10 Integrated controller 21 Motor rotation speed sensor
MG motor generator
EOP electric oil pump
MOP mechanical oil pump
CL2 2nd clutch

Claims (2)

A drive motor that generates power to be applied to the drive wheels;
A starting clutch interposed between the drive motor and the drive wheel;
An electric oil pump driven by an electric motor;
A mechanical oil pump driven by the drive motor;
An electric oil pump abnormality detecting means for detecting an abnormality of the electric oil pump;
Motor rotation number detecting means for detecting the rotation number of the drive motor;
Motor control means for controlling the output torque of the drive motor in accordance with a target torque;
Starting clutch fastening torque control means for controlling the fastening torque of the starting clutch to be higher than the target torque;
When the electric oil pump is malfunctioning and the rotational speed of the drive motor is smaller than a set value, the fastening torque is controlled to coincide with the target torque, and the rotational speed of the drive motor is adjusted. An abnormality control means for raising the set value or more;
A hydraulic control device comprising: The hydraulic control device according to claim 1,
The starting clutch engagement torque control means is configured to release the starting clutch when the electric oil pump is malfunctioning and the rotational speed of the drive motor is smaller than a set value and the vehicle is stopped. A hydraulic control device characterized by controlling.

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