JP5229571B2 - Hybrid vehicle and oil pump control method - Google Patents

Description

  The present invention relates to a hybrid vehicle and an oil pump control method capable of idling and stopping while there is a vehicle speed by running with power from at least one of an internal combustion engine and an electric motor directly connected to each drive shaft.

  In Patent Documents 1 to 3, in addition to a mechanical oil pump for hydraulically driving a transmission or the like, an electric oil pump is provided, and the electric oil pump is started in response to a stop command for the internal combustion engine. A hydraulic control device that stops an electric oil pump in response to a start command is disclosed. In such a hydraulic control device, the mechanical oil pump is driven in accordance with the operation of the internal combustion engine, and supplies an oil amount or hydraulic pressure necessary for the transmission. On the other hand, the electric oil pump is driven by power supply from the battery when the internal combustion engine is stopped, and supplies, for example, an oil amount or hydraulic pressure necessary for driving and controlling the transmission when the vehicle starts to travel. .

  Therefore, when a vehicle equipped with the hydraulic control device has an idle stop function, hydraulic oil is supplied to the transmission by a mechanical oil pump during operation of the internal combustion engine, and the transmission is transmitted by an electric oil pump during idle stop. Is supplied with hydraulic oil.

JP 2007-232115 A JP 2003-262264 A JP 2001-99282 A

  It is conceivable that the above-described hydraulic control device is mounted on a vehicle that is idled while the vehicle speed is present. In such a vehicle, the internal combustion engine is stopped before the vehicle speed becomes zero, so that fuel consumption can be reduced compared to a vehicle that stops the internal combustion engine after the vehicle speed becomes zero. However, in the vehicle, if the driver applies a strong brake between the time when the vehicle is idle and the vehicle is completely stopped, if sufficient hydraulic pressure is not supplied to the transmission, Is mechanically undesirable.

  For example, as shown in FIG. 7, when a belt-type continuously variable transmission (CVT) including a torque converter is mounted on a vehicle, when the vehicle is suddenly braked, a CVT pulley and A huge inertia torque is added to the belt through the drive shaft. In order for the pulley and the belt to withstand this huge inertia torque, it is necessary to apply a high side pressure to each pulley. This is because if the lateral pressure is not sufficient, belt slip may occur. Therefore, it is necessary to supply the continuously variable transmission with a hydraulic pressure sufficient to realize a sufficient lateral pressure that can withstand the inertia torque generated during sudden braking.

  As described above, the mechanical oil pump is driven along with the operation of the internal combustion engine. Therefore, when the internal combustion engine is in operation, a sufficiently high hydraulic pressure is supplied to the transmission by the mechanical oil pump. On the other hand, the electric oil pump is driven during idle stop. However, the hydraulic pressure that can be supplied to the transmission by the electric oil pump varies depending on the discharge capacity. For this reason, in order to supply a hydraulic pressure as high as that of a mechanical oil pump to the transmission, an electric oil pump having a high discharge capacity is required. However, an electric oil pump having a high discharge capacity is not preferable because it is larger in size and weight than an electric oil pump having a low discharge capacity.

  Therefore, it is necessary to mount an electric oil pump having a high discharge capacity on a vehicle that stops idling while the vehicle speed is present, but an electric oil pump having a low discharge capacity on a vehicle that stops idling after the vehicle speed becomes zero. Should be installed. However, since the latter vehicle does not stop idling until the vehicle speed becomes zero, the fuel consumption cannot be reduced as compared with the former vehicle.

  An object of the present invention is to provide a hybrid vehicle and an oil pump control method capable of idling while a vehicle speed is present without using an electric oil pump having a high discharge capacity.

In order to solve the above problems and achieve the object, a hybrid vehicle according to a first aspect of the present invention is connected to an internal combustion engine (for example, the internal combustion engine 103 in the embodiment) and a crankshaft of the internal combustion engine. And an electric motor (for example, the electric motor 101 in the embodiment) that transmits the driving force to the crankshaft, and fastening means (for example, the FWD / RVS clutch in the embodiment) arranged between the electric motor and the driving wheel. ) has, continuously changing the ratio of the internal combustion engine and the rotational speed of the output shaft and the rotational speed of the input shaft to which the driving force at least from either via the fastening hand stage of the motor is input A hydraulic pressure is generated by being driven on the basis of an output from a continuously variable transmission (for example, the continuously variable transmission 113 in the embodiment) and the internal combustion engine or the electric motor, and the hydraulic pressure is continuously changed. A mechanical oil pump (for example, the mechanical oil pump 115 in the embodiment) supplied to the machine, and a control unit (for example, the management ECU 109 in the embodiment) that stops the internal combustion engine when an idle stop condition is satisfied. , 209), and a vehicle speed detection unit (for example, rotation speed sensors 111a and 111b and management ECUs 109 and 209 in the embodiment) for detecting the vehicle speed of the hybrid vehicle, and the control parts are cut off the hybrid vehicle is the idle stop condition is pre-Symbol fastening means when stopping the internal combustion engine in order to satisfied during deceleration, the vehicle speed during idling stop, the first threshold value (e.g., implemented The second threshold value (e.g., the first threshold value Vth1) is less than the first threshold value and smaller than the first threshold value. When the second threshold value Vth2) In the above embodiments, is characterized in that by driving the electric motor driving the mechanical oil pump.

Further, in the hybrid vehicle of the invention according to claim 2 , the control unit stops driving the electric motor when the vehicle speed at the time of idling stop falls below the second threshold value.

Furthermore, in the hybrid vehicle of the invention described in claim 3 , an electric oil pump (for example, an electric oil pump that is driven by power supply from a capacitor and supplies operating hydraulic pressure to the continuously variable transmission according to control by the control unit. The electric oil pump 201) according to the embodiment is provided, and the control unit drives the electric oil pump when the vehicle speed at the time of idling stop falls below the second threshold value, and rotates the electric oil pump. The driving of the electric motor is stopped when the number exceeds a predetermined number.

Furthermore, in the oil pump control method according to the fourth aspect of the present invention, the internal combustion engine (for example, the internal combustion engine 103 in the embodiment) and the crankshaft of the internal combustion engine are connected, and the driving force is transmitted to the crankshaft. An electric motor (for example, the electric motor 101 in the embodiment), and fastening means (for example, an FWD / RVS clutch in the embodiment) disposed between the electric motor and the drive wheel. motor at least one of the continuously variable transmission for continuously varying the ratio between the rotational speed of the output shaft and the rotational speed of the input shaft to which a driving force is input through the fastening hand stage (e.g., embodiment And a mechanical oil pump that generates hydraulic pressure by being driven based on an output from the internal combustion engine or the electric motor and supplies the hydraulic pressure to the continuously variable transmission. (For example, the mechanical oil pump 115 in the embodiment), and a control unit (for example, the management ECU 109, 209 in the embodiment) that controls each operation of the internal combustion engine, the electric motor, and the continuously variable transmission; , An oil pump control method when the hybrid vehicle is idled during deceleration traveling, wherein the control unit determines whether or not the hybrid vehicle is in an idle stopped state, and When the vehicle speed is equal to or lower than a first threshold value and equal to or higher than a second threshold value that is smaller than the first threshold value, the motor is driven to drive the mechanical oil pump. It is said.

Furthermore, in the oil pump control method of the invention according to claim 5 , the control unit is driven by power supply from a capacitor when the vehicle speed at the time of idling stop falls below the second threshold value, and An electric oil pump (for example, the electric oil pump 201 in the embodiment) that supplies the operating oil pressure to the step transmission is driven, and the driving of the electric motor is stopped when the number of rotations of the electric oil pump exceeds a predetermined number It is characterized by doing.

According to the hybrid vehicle of the invention described in claims 1 to 3 and the oil pump control method of the invention described in claims 4 to 5 , the vehicle decreases in speed from a state where the vehicle speed is equal to or higher than the first threshold value, and is idle stopped. Even if the state is reached, the mechanical oil pump is driven by the drive of the electric motor until the vehicle speed becomes at least less than the second threshold value. Therefore, even if the driver applies a strong brake while idling while the vehicle speed is, the mechanical oil pump is operating if the vehicle speed is at least the second threshold value or more. Sufficient oil pressure is provided to withstand the inertia torque generated during sudden braking. For this reason, it is possible to provide a vehicle that can cope with sudden braking in an idle stop state without providing an electric oil pump having a high discharge capacity.

According to the hybrid vehicle of the third aspect of the invention and the oil pump control method of the fifth aspect of the invention, when the vehicle speed decreases to the second threshold value, the electric oil pump is driven and the number of revolutions is the threshold. When the value is exceeded, stop the motor. Therefore, even if the driver applies a strong brake while idling while the vehicle speed is high, at least one of the mechanical oil pump and the electric oil pump is operating, so the transmission is generated during sudden braking. Sufficient hydraulic pressure is provided to withstand the inertia torque.

The discharge capacity of the electric oil pump included in the hybrid vehicle of the invention described in claim 3 and the oil pump control method of the invention described in claim 5 is not particularly high, but the electric oil pump has a second vehicle speed. The inertia torque that can be generated is relatively small because it is used in a state below the threshold. Moreover, the electric oil pump is not used alone until the rotational speed of the electric oil pump exceeds the threshold value. Therefore, it is possible to provide a vehicle that can more safely handle sudden braking in an idling stop state without providing an electric oil pump with high discharge capability.

The block diagram which shows the internal structure of HEV of 1st Embodiment. The flowchart which shows the operation | movement which management ECU109 with which the vehicle of 1st Embodiment is provided performs. The figure which shows transition of the drive state of the electric motor 101 in the vehicle of 1st Embodiment which carries out an idle stop while there exists a vehicle speed. The block diagram which shows the internal structure of HEV of 2nd Embodiment. The flowchart which shows operation | movement which management ECU209 with which the vehicle of 2nd Embodiment is provided performs. The figure which shows transition of each drive state of the electric motor 101 and the electric oil pump in the vehicle of 2nd Embodiment which carries out an idle stop while a vehicle speed exists. The figure explaining the inertia torque which is added to the belt type continuously variable transmission including the torque converter when the vehicle is suddenly braked

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  HEV (Hybrid Electrical Vehicle) travels by the driving force of an electric motor and / or an internal combustion engine. In the HEV of the embodiment described below, the drive shaft of the electric motor is directly connected to the drive shaft of the internal combustion engine.

(First embodiment)
FIG. 1 is a block diagram showing an internal configuration of the HEV according to the first embodiment. As shown in FIG. 1, the HEV (hereinafter simply referred to as “vehicle”) of the first embodiment includes an electric motor (MOT) 101, an internal combustion engine (ENG) 103, a motor ECU (MOT ECU) 105, Engine ECU (ENG ECU) 107, management ECU (MG ECU) 109, rotation speed sensors 111a and 111b, a belt-type continuously variable transmission (CVT) 113 including a torque converter, mechanical oil And a pump (OP) 115.

  The electric motor 101 is a three-phase AC motor, for example, and generates a driving force for the vehicle to travel. The electric motor 101 is supplied with high-voltage (for example, 100 to 200 V) power from the battery via an inverter (not shown). The internal combustion engine 103 generates a driving force for the vehicle to travel. The driving force from the electric motor 101 and the internal combustion engine 103 is transmitted to the drive wheels 123L and 123R via the CVT 113 and the drive shaft 121.

  The motor ECU 105 controls the operation of the electric motor 101. The engine ECU 107 controls the operation of the internal combustion engine 103. The management ECU 109 controls the electric motor 101, the internal combustion engine 103, and the like. Further, the management ECU 109 receives signals from the rotational speed sensors 111a and 111b, and information such as the accelerator pedal opening (AP opening) and the brake pedal pressing force (braking force). The management ECU 109 calculates the vehicle speed Vp based on the signals sent from the rotation speed sensors 111a and 111b. The management ECU 109 determines whether the traveling state of the vehicle satisfies the idle stop condition based on the vehicle speed Vp, the AP opening degree, and the brake depression force. When the idle stop condition is satisfied, the management ECU 109 instructs the engine ECU 107 to stop the operation of the internal combustion engine 103. In the present embodiment, it is assumed that the management ECU 109 satisfies the idle stop condition when the vehicle speed Vp is equal to or less than a predetermined value, the AP opening is 0, and the brake pedal force is equal to or greater than the predetermined value.

  Furthermore, the management ECU 109 controls driving of the mechanical oil pump 115 by driving of the electric motor 101 in accordance with the vehicle speed Vp after the vehicle is in an idle stop state. Details of the control by the management ECU 109 will be described later.

  The rotation speed sensors 111a and 111b detect the rotation speeds of the drive wheels 123L and 123R. The management ECU 109 receives signals indicating the rotation speeds of the drive wheels 123L and 123R from the rotation speed sensors 111a and 111b.

  The CVT 113 converts the driving force from the electric motor 101 and / or the internal combustion engine 103 into a rotation speed and torque at a desired gear ratio, and transmits the rotation speed and torque to the driving shaft 121. In addition, CVT113 of this embodiment is the structure similar to the transmission shown in FIG. Accordingly, the hydraulic pressure is supplied to the CVT 113 by the mechanical oil pump 115. The mechanical oil pump 115 is driven as the internal combustion engine 103 is operated, and supplies a predetermined hydraulic pressure to the CVT 113. As described above, the drive shaft of the electric motor 101 is directly connected to the drive shaft of the internal combustion engine 103. For this reason, even if the internal combustion engine 103 is in a stopped state, if the electric motor 101 is driven, the drive shaft of the internal combustion engine 103 rotates and the mechanical oil pump 115 is also driven.

  FIG. 2 is a flowchart illustrating an operation performed by the management ECU 109 included in the vehicle according to the first embodiment. As shown in FIG. 2, the management ECU 109 determines whether or not the vehicle is in an idle stop state (step S101). If the vehicle is in an idle stop state, the process proceeds to step S103, and if not, the process proceeds to step S109. In step S103, the management ECU 109 determines whether or not the vehicle speed Vp calculated based on the signals sent from the rotation speed sensors 111a and 111b is equal to or lower than the first threshold value Vth1 (Vp ≦ Vth1), and Vp ≦ Vth1. If so, the process proceeds to step S105. If Vp> Vth1, the process proceeds to step S109.

  In step S105, the management ECU 109 determines whether or not the vehicle speed Vp is equal to or higher than the second threshold value Vth2 (Vp ≧ Vth2). If Vp ≧ Vth2, the process proceeds to step S107. If Vp <Vth2, the process proceeds to step S109. move on. The second threshold value Vth2 is smaller than the first threshold value Vth1.

  In step S107, the management ECU 109 starts the operation of the electric motor 101 after releasing the engagement of the FWD / RVS clutch (hereinafter simply referred to as “clutch”) provided between the torque converter in the CVT 113 and the drive pulley. The motor ECU 105 is instructed. As described above, since the drive shaft of the electric motor 101 is directly connected to the drive shaft of the internal combustion engine 103, the mechanical oil pump 115 is also driven when the electric motor 101 is driven. On the other hand, in step S109, the management ECU 109 ends the process without issuing an operation start instruction of the electric motor 101.

  According to the present embodiment, as shown in FIG. 3, even when the vehicle speed drops from the state where the vehicle speed Vp is equal to or higher than the first threshold value Vth1 to the idle stop state, the vehicle speed Vp remains at the second threshold value Vth2. The mechanical oil pump 115 is driven by the drive of the electric motor 101 until it becomes less than the value. Accordingly, even if the driver applies a strong brake while the vehicle is idling while the vehicle speed is, the mechanical oil pump 115 is in operation if the vehicle speed Vp is at least the second threshold value Vth2 or more. Is supplied with sufficient hydraulic pressure to withstand the inertia torque generated during sudden braking. For this reason, it is possible to provide a vehicle that can cope with sudden braking in an idle stop state without providing an electric oil pump having a high discharge capacity.

  In the present embodiment, the FWD / RVS clutch is disengaged and then the motor ECU 105 is instructed to start the operation of the electric motor 101. However, sufficient internal oil pressure is supplied and the internal combustion based on the operation of the electric motor 101 is performed. When the engine 103 has a rotational speed corresponding to that during idling, the torque converter can release the lockup clutch without releasing the FWD / RVS clutch, so that the torque converter can Torque transmission to can be absorbed.

(Second Embodiment)
FIG. 4 is a block diagram illustrating an internal configuration of the HEV according to the second embodiment. As shown in FIG. 4, the HEV of the second embodiment further includes an electric oil pump (EOP) 201 in addition to the components included in the HEV of the first embodiment. The operation of the management ECU 209 provided in the HEV of the present embodiment is partly different from that of the first embodiment. In FIG. 4, the same reference numerals are given to the components common to FIG. 1.

  The electric oil pump 201 is driven by power supply from a capacitor (not shown) and supplies a predetermined hydraulic pressure to the CVT 113. Electric oil pump 201 includes a pump rotation speed sensor (not shown) that detects the rotation speed. A signal indicating the rotational speed of the electric oil pump 201 is sent from the pump rotational speed sensor to the management ECU 209.

  The management ECU 209 of the present embodiment controls the driving of the mechanical oil pump 115 and the driving of the electric oil pump 201 by driving the electric motor 101 according to the vehicle speed Vp after the vehicle enters the idle stop state.

  FIG. 5 is a flowchart illustrating an operation performed by the management ECU 209 included in the vehicle according to the second embodiment. As shown in FIG. 5, the management ECU 209 determines whether or not the vehicle is in an idle stop state (step S201). If the vehicle is in an idle stop state, the process proceeds to step S203, and if not, the process proceeds to step S205. In step S203, the management ECU 209 determines whether or not the vehicle speed Vp calculated based on the signals sent from the rotation speed sensors 111a and 111b is equal to or lower than the first threshold value Vth1 (Vp ≦ Vth1), and Vp ≦ Vth1. If YES in step S209, the process advances to step S209. If Vp> Vth1, the process advances to step S205.

  In step S205, the management ECU 209 does not issue an instruction to start driving the electric oil pump 201, and proceeds to step S207. In step S207, the management ECU 209 ends the process without issuing an operation start instruction for the electric motor 101. In step S209, the management ECU 209 determines whether or not the vehicle speed Vp calculated based on the signals sent from the rotational speed sensors 111a and 111b is equal to or higher than the second threshold value Vth2 (Vp ≧ Vth2), and Vp ≧ Vth2 If so, the process proceeds to step S211, and if Vp <Vth2, the process proceeds to step S215. The second threshold value Vth2 is smaller than the first threshold value Vth1.

  In step S211, the management ECU 209 does not issue an instruction to start driving the electric oil pump 201, and proceeds to step S213. In step S213, the management ECU 209 instructs the motor ECU 105 to start the operation of the electric motor 101 after releasing the engagement of the clutch in the CVT 113. As described above, since the drive shaft of the electric motor 101 is directly connected to the drive shaft of the internal combustion engine 103, the mechanical oil pump 115 is also driven when the electric motor 101 is driven. On the other hand, in step S215, the management ECU 209 issues a drive start instruction for the electric oil pump 201.

  After performing step S215, the management ECU 209 determines whether the rotational speed Nm of the electric oil pump 201 indicated by the signal sent from the pump rotational speed sensor of the electric oil pump 201 is greater than the threshold value N0 (Nm> N0). If Nm> N0, the process proceeds to step S219. If Nm ≦ N0, the process proceeds to step S221. In step S219, the management ECU 209 instructs the motor ECU 105 to stop the operation of the electric motor 101. As described above, since the drive shaft of the motor 101 is directly connected to the drive shaft of the internal combustion engine 103, the mechanical oil pump 115 also stops operating when the motor 101 stops. On the other hand, in step S221, the management ECU 209 instructs the motor ECU 105 to continue the operation of the electric motor 101.

  According to the present embodiment, as shown in FIG. 6, even when the vehicle drops in the idling stop state from the state where the vehicle speed Vp is equal to or higher than the first threshold value Vth1, first, the mechanical type is driven by driving the electric motor 101. The oil pump 115 is driven. Thereafter, when the vehicle speed Vp decreases to the second threshold value Vth2, the electric oil pump 201 is driven, and the electric motor 101 is stopped when the rotation speed Nm exceeds the threshold value N0. Therefore, even if the driver applies a strong brake while idling while the vehicle speed is, at least one of the mechanical oil pump 115 and the electric oil pump 201 is operating, and therefore the CVT 113 is in a sudden braking state. Sufficient hydraulic pressure that can withstand the generated inertia torque is supplied.

  The discharge capacity of the electric oil pump 201 used in the present embodiment is not particularly high. However, since the electric oil pump 201 is used in a state where the vehicle speed Vp is equal to or lower than the second threshold value Vth2, an inertia torque that can be generated is used. Is relatively small. Moreover, the electric oil pump 201 is not used alone until the rotational speed Nm of the electric oil pump 201 exceeds the threshold value N0. Therefore, it is possible to provide a vehicle that can more safely handle sudden braking in an idling stop state without providing an electric oil pump with high discharge capability.

101 Electric motor (MOT)
103 Internal combustion engine (ENG)
105 Motor ECU (MOT ECU)
107 Engine ECU (ENG ECU)
109,209 Management ECU (MG ECU)
111a, 111b Rotational speed sensor 113 Continuously variable transmission (CVT)
115 Mechanical oil pump (OP)
201 Electric oil pump (EOP)

Claims (5)

An internal combustion engine;
An electric motor connected to the crankshaft of the internal combustion engine and transmitting a driving force to the crankshaft;
Has a fastening means which is disposed between the electric motor and drive wheels, the internal combustion engine and the electric motor at least from one of the output shaft and the rotational speed of the input shaft to which the driving force via the fastening means is input A continuously variable transmission that continuously changes the ratio to the rotational speed;
A mechanical oil pump that generates hydraulic pressure by being driven based on an output from the internal combustion engine or the electric motor, and supplies the hydraulic pressure to the continuously variable transmission;
A control unit that stops the internal combustion engine when an idle stop condition is satisfied,
A vehicle speed detector for detecting the vehicle speed of the hybrid vehicle,
Wherein the control unit blocks the previous SL fastening means when stopping the internal combustion engine to the hybrid vehicle is the idle stop condition is satisfied during the deceleration, the vehicle speed during idling stop, the first threshold value or less, And when it is more than the 2nd threshold value which is a value smaller than the said 1st threshold value, the said electric motor is driven and the said mechanical oil pump is driven, The hybrid vehicle characterized by the above-mentioned. The hybrid vehicle according to claim 1 ,
The said control part stops the drive of the said motor, when the vehicle speed at the time of an idle stop falls below the said 2nd threshold value, The hybrid vehicle characterized by the above-mentioned. The hybrid vehicle according to claim 1 ,
In accordance with control by the control unit, an electric oil pump that is driven by power supply from a capacitor and supplies hydraulic pressure to the continuously variable transmission,
The control unit drives the electric oil pump when the vehicle speed at the time of idling stop falls below the second threshold value, and drives the electric motor when the rotational speed of the electric oil pump exceeds a predetermined number. A hybrid vehicle characterized by stopping the vehicle. An internal combustion engine;
An electric motor connected to the crankshaft of the internal combustion engine and transmitting a driving force to the crankshaft;
Has a fastening means which is disposed between the electric motor and drive wheels, the internal combustion engine and the electric motor at least from one of the output shaft and the rotational speed of the input shaft to which the driving force via the fastening means is input A continuously variable transmission that continuously changes the ratio to the rotational speed;
A mechanical oil pump that generates hydraulic pressure by being driven based on an output from the internal combustion engine or the electric motor, and supplies the hydraulic pressure to the continuously variable transmission;
A control unit that controls each operation of the internal combustion engine, the electric motor, and the continuously variable transmission, and an oil pump control method when the hybrid vehicle is idled during deceleration traveling,
The controller is
Determine whether the hybrid vehicle is in an idle stop state,
When the vehicle speed of the hybrid vehicle at the time of idling stop is equal to or lower than a first threshold value and equal to or higher than a second threshold value that is smaller than the first threshold value, the electric motor is driven and the mechanical type is driven. An oil pump control method comprising driving an oil pump. The oil pump control method according to claim 4 ,
The controller is
When the vehicle speed at the time of idling stop falls below the second threshold value, an electric oil pump that drives by supplying electric power from a battery and supplies hydraulic pressure to the continuously variable transmission is driven,
An oil pump control method comprising: stopping driving of the electric motor when the rotational speed of the electric oil pump exceeds a predetermined number.

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