JP2011190900A - Control device of electric oil pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an electric oil pump wherein, when an engine is put under automatic stop control, it is practicable to establish two functions compatibly, a function to reduce an engagement shock at restarting by supplying a restarting oil pressure to a transmission mechanism using the electric oil pump and a function to secure the restarting performance of the electric oil pump under influence of a reduction of the consumption of electric power. <P>SOLUTION: When a source current Ib of a drive circuit of a motor to drive the electric oil pump, exceeds a first restriction value Ib1 set on the basis of the driving power required to generate the restarting oil pressure for the transmission mechanism, an increase of the source current Ib is suppressed by prohibiting an increase of the operating amount (S1-S4 → S6-S8 → S5), and an operating amount is reduced (S1→S2→S9→S5), when the source current Ib exceeds a second restriction value Ib2 set as an allowable current value to suppress a drop of battery voltage for securing the restarting performance. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control device for an electric oil pump that supplies hydraulic pressure for restart to a speed change mechanism connected to an engine during automatic operation stop control for temporarily stopping the operation of the engine.

  In vehicles with an idle stop mechanism that automatically stops idle operation of the engine when temporarily stopped, the hydraulic pressure of the speed change mechanism connected to the engine decreases with the rotation of the oil pump driven by the engine after the engine has been idle stopped. descend.

  For this reason, in the continuously variable transmission, in the continuously variable transmission, the starting clutch mechanism that connects the engine and the transmission mechanism input shaft, and in the stepped automatic transmission, when the clutch mechanism for engaging the transmission element is engaged at the time of restart, There was a shock.

  Therefore, in Patent Document 1, in a vehicle with an idle stop mechanism, hydraulic pressure is supplied from an electric oil pump to the speed change mechanism connected to the engine during engine idle stop control (before the engine is stopped). A technique for mitigating a shock (hereinafter referred to as an engagement shock) when a clutch mechanism is engaged in a transmission mechanism is disclosed.

JP 2009-293649 A

  The working hydraulic pressure supplied to the speed change mechanism for this type of engine restart may be a lower hydraulic pressure than the fastening hydraulic pressure supplied during traveling (hereinafter referred to as restart hydraulic pressure) that can alleviate the fastening shock.

However, if the drive motor of the electric oil pump is increased to the target rotational speed in order to increase the transmission hydraulic pressure to the restart hydraulic pressure, the power supply current may become excessive due to individual differences (performance variation) of the pump. .
Thus, when an excessive power supply current flows, the voltage drop of the battery as the drive power supply increases, and restartability (decreasing cranking speed, lowering ignition energy, poor control of the hydraulic control solenoid in the transmission, etc.) Could get worse.

  The present invention has been made to solve such a conventional problem, and by appropriately controlling the power supply current of the electric oil pump during the automatic engine stop control, the battery voltage drop is suppressed and restarted. It is an object of the present invention to provide a control device for an electric oil pump capable of reducing the fastening shock as much as possible while ensuring the performance.

For this reason, the present invention
A control device for an electric oil pump that maintains an operating hydraulic pressure of a speed change mechanism connected to the engine at a level higher than a restart hydraulic pressure by an oil pressure supplied from the electric oil pump during automatic engine stop control. Each means is configured.

A. B. Power supply current detection means for detecting the power supply current of the drive circuit of the motor that drives the electric oil pump. C. First limit value setting means for setting a first limit value of the power supply current based on the driving power of the motor necessary for generating the restart hydraulic pressure. C. Second limit value setting means for setting a second limit value larger than the first limit value as the allowable limit of the power supply current. First power supply current limiting means for controlling to suppress an increase in the power supply current when the power supply current value detected by the power supply current detection means exceeds the first limit value and is less than the second limit value; Second power supply current limiting means for controlling the power supply current to be kept below the second limit value when the power supply current value detected by the power supply current detection means exceeds the second limit value.

  By limiting the power supply current value of the drive circuit in stages while comparing the first limit value and the second limit value with different magnitudes, the increase in current is appropriately suppressed and the restartability is maintained well. However, the engagement hydraulic shock at the time of restart can be reduced by making the supply hydraulic pressure to the transmission mechanism as close to the restart hydraulic pressure as possible.

The figure which shows the driving force transmission system of the vehicle provided with the control apparatus of the electric oil pump which concerns on embodiment. The control block diagram of the control apparatus of the said electric oil pump. The flowchart of the power supply current control of the electric oil pump concerning 1st Embodiment. The flowchart of the power supply current control of the electric oil pump concerning 2nd Embodiment. The flowchart of the power supply current control of the electric oil pump concerning 3rd Embodiment. The flowchart of the power supply current control of the electric oil pump concerning 4th Embodiment. The flowchart of the power supply current control of the electric oil pump concerning 5th Embodiment. The flowchart of the power supply current control of the electric oil pump concerning 6th Embodiment. In 1st Embodiment, the time chart which shows the difference in the effect | action by the presence or absence of the restriction | limiting by a 1st restriction value. The time chart which shows a state change when the restriction | limiting by the 2nd restriction value is performed by permanent increase and temporary increase of motor rotation resistance in 1st Embodiment. The time chart which shows the state change at the time of control by 3rd Embodiment. The time chart which shows the state change at the time of control by 4th Embodiment. The time chart which shows the state change at the time of control by 5th Embodiment when the temporary increase of motor rotation resistance arises. The time chart which shows the state change at the time of control by 5th Embodiment when the temporary increase of motor rotation resistance arises.

  Embodiments of the present invention will be described below.

  In FIG. 1, a continuously variable transmission 4 is connected to an engine (internal combustion engine) 1 via a torque converter 2 and a forward / reverse switching mechanism 3 that is a starting clutch mechanism.

  The forward / reverse switching mechanism 3 includes, for example, a planetary gear mechanism including a ring gear, a pinion and a pinion carrier connected to the engine output shaft, a sun gear connected to the transmission input shaft, and a reverse brake that fixes the transmission case to the pinion carrier. And a forward clutch that couples the transmission input shaft and the pinion carrier, and switches between forward and reverse of the vehicle. Switching between the reverse brake and the forward clutch is performed by switching hydraulic engagement using hydraulic oil common to the continuously variable transmission 4.

  The continuously variable transmission 4 includes a primary pulley 41 and a secondary pulley 42, and a V belt 43 hung between these pulleys. The primary pulley 41 rotates via the V belt 43 through the secondary pulley 42. The rotation of the secondary pulley 42 is transmitted to the drive wheels to drive the vehicle.

  During the transmission of the driving force, the movable conical plate of the primary pulley 41 and the movable conical plate of the secondary pulley 42 are moved in the axial direction to change the contact position radius with the V-belt 43, whereby the primary pulley 41 and the secondary pulley 42 The rotation ratio, that is, the gear ratio can be changed.

  The transmission mechanism 20 including the forward / reverse switching mechanism 3 and the continuously variable transmission 4 is controlled as follows.

  The CVT control unit 5 calculates a shift control signal based on various signals of the vehicle, and the pressure adjusting mechanism 6 to which the shift control signal has been input converts the discharge pressure from the mechanical oil pump 7 driven by the engine into the transmission mechanism 20. This is done by adjusting the pressure for each part and supplying each part.

  On the other hand, an electric oil pump 8 is provided in a passage that bypasses the mechanical oil pump 7. The electric oil pump is driven by a control signal from the CVT control unit 5 in order to relieve a fastening shock when the vehicle is restarted after an idle stop.

  That is, when the vehicle is temporarily stopped and the idle stop control is started, the electric oil pump 8 is driven to supply hydraulic oil to each part of the transmission mechanism 20. Thereby, after maintaining the hydraulic pressure of the forward clutch of the forward / reverse switching mechanism 3 to be equal to or higher than the restart hydraulic pressure, the engine stop is permitted and the idle operation is stopped.

  In addition, a check valve 9 is provided in the oil passage at the outlet of the electric oil pump 8 to prevent oil backflow during normal operation. Further, as shown by the dotted line in the figure, a relief valve 10 that opens at a predetermined pressure or lower may be provided in order to limit the discharge pressure from the electric oil pump 8 to a predetermined pressure or lower.

  FIG. 2 shows a control system block diagram of the restart hydraulic control.

  The target value calculation unit 51 receives detection signals (vehicle speed, brake, accelerator, shift position, oil / water temperature, engine speed, battery voltage, etc.) from various sensors of the vehicle, and the vehicle detected based on these signals. The target value of the rotation speed (or motor current) of the motor 81 that drives the electric oil pump 8 is calculated according to the operating state.

  The feedback controller 52 inputs the target value (target motor rotation speed or target motor current) from the target value calculation unit 51, and the actual rotation speed or actual motor current of the motor 81, which is a control amount, and the motor 81. The actual power supply current Ib of the drive circuit 82 is input. The power supply current Ib is detected by the current sensor 53. The actual number of revolutions of the motor 81 can be detected by inputting the phase voltage of the motor from the drive circuit 82 as well as directly measuring by a sensor.

  Normally, the feedback operation amount calculated using PID control or the like is output and controlled so that the actual rotational speed (actual motor current) of the motor 81 approaches the target rotational speed (target motor current). The operation amount is, for example, a pulse width (duty ratio) in the case of PWM (pulse width modulation) control. When feedback control is performed using a motor current, the motor current may be detected by a sensor, but may be calculated from a power supply current and a duty ratio.

  However, if only an ordinary feedback control is performed and an abnormality occurs in which the motor rotation resistance of the electric oil pump 8 increases as described above, the power supply current of the drive circuit 82 of the motor 81 becomes excessive, which is a drive source. The battery voltage is greatly reduced and the restartability is deteriorated. In other words, the cranking rotational speed is reduced due to the power shortage of the starter motor, the amount of ignition energy is reduced, the control of the hydraulic control solenoid in the transmission is poor (due to the malfunction of the solenoid itself due to the voltage drop), and the like.

  In addition, in consideration of individual differences (performance variation) of the electric oil pump 8, especially when the target value of the motor rotation speed (or motor current) is designed to be high so that any individual can secure the restart hydraulic pressure, In some individuals with little variation, the number of motor revolutions may increase excessively, resulting in excessive power consumption.

  Therefore, the operation amount set in the normal feedback control is corrected, and control for suppressing the power source current from being excessive is performed. This control will be described in detail later.

  The drive circuit 82 outputs a drive signal to the motor 81 to drive the motor 81, whereby the electric oil pump 8 is driven to drive the forward clutch or reverse brake of the forward / reverse switching mechanism 3 and other parts of the transmission mechanism 20. Is supplied with hydraulic pressure. The restart hydraulic pressure is lower than the hydraulic pressure for completely engaging the clutch engagement mechanism of each part of the transmission mechanism 20, and may be set to a magnitude sufficient to relieve the engagement shock when restarting from the idle stop.

  Next, control for suppressing the excessive power supply current will be described.

  In the control according to the first embodiment, in order to limit the power supply current Ib of the drive circuit 82, the first limit value Ib1 and the second limit value Ib2 are set, and the actual power supply current Ib is set to these two current limit values Ib1, Ib2. Control according to the magnitude of current is performed.

  When the power supply current Ib is equal to or less than the first limit value Ib1, the motor rotation speed (or motor current) is feedback-controlled using the operation amount calculated using the normal control gain as it is. On the other hand, when the actual power supply current Ib exceeds the first limit value Ib1 (and less than the second limit value Ib2), control is performed using the manipulated variable modified to prohibit the increase in manipulated variable, and the actual power supply current When Ib exceeds the second limit value Ib2, control is performed using the manipulated variable modified to reduce the manipulated variable.

  FIG. 3 is a flowchart of the control of the first embodiment.

  In step S1, the power supply voltage (battery voltage) VB of the drive circuit 82 is read, and the first limit value Ib1 and the second limit value Ib2 are set based on the voltage VB.

  Here, the first limit value Ib1 is set based on the driving power of the motor necessary for generating the restart hydraulic pressure.

  More specifically, the motor speed necessary for obtaining the restart hydraulic pressure (or the motor current necessary for obtaining the required motor speed) is the difference between pumps (pump main body and motor performance variations). Have. Therefore, the power supply current value that obtains the required power by adding the margin (margin) to the lower limit value (lower limit power) of power that can ensure the restart hydraulic pressure at any required speed (required motor current) or more. As a first limit value Ib1 is set.

  In the present embodiment, the first limit value Ib1 is variably set as follows according to the fluctuation of the battery voltage (drive voltage) VB. For example, the first limit value when the required power is 60 W is variably set as 5 A when the voltage VB is 12 V and 6 A when the voltage VB is 10 V.

  Thus, by setting the first limit value Ib1 variably according to the battery voltage VB, it is possible to set the first limit value Ib1 that does not exceed the required power even if the battery voltage VB changes.

  However, for simplicity, the first limit value Ib1 corresponding to the allowable lower limit value of the battery voltage VB that can permit driving of the electric oil pump may be set as a fixed value.

  On the other hand, the second limit value Ib2 is set as a limit value of the allowable current that makes it difficult to ensure restartability when the power supply current Ib is larger than that and the battery voltage greatly decreases.

  Here, when the battery voltage VB is low, the battery charge amount is small compared to when the battery voltage VB is high, and the battery voltage VB tends to decrease. Therefore, the second limit value Ib2 can be set to a lower value as the battery voltage VB is lower. Set to. However, the second limit value Ib2 is maintained at a value larger than the first limit value Ib1.

  As described above, the second limit value Ib2 is also variably set according to the battery voltage VB, so that the second limit value Ib2 can be set to an allowable level even when the battery voltage VB changes. It can be set to a value with no excess or deficiency that can be maintained above.

  However, similarly to the first limit value Ib1, the second limit value Ib2 corresponding to the allowable lower limit value of the battery voltage VB that can permit the drive of the electric oil pump may be set as a fixed value.

  In step S2, it is determined whether the actual power supply current Ib detected by the current sensor 53 is equal to or less than the second limit value Ib2.

  When it is determined in step S2 that the actual power supply current Ib is equal to or less than the second limit value Ib2, the process proceeds to step S3, and based on the target rotational speed of the motor and the actual rotational speed (target motor current and actual motor current), for example, PID The manipulated variable is calculated by using a normal control gain (P, I, D) by (proportional integral derivative) control.

  Next, in step S4, it is determined whether the actual power supply current Ib is equal to or less than the first limit value Ib1.

  When it is determined in step S4 that the actual power supply current Ib is equal to or less than the first limit value Ib1, the process proceeds to step S5, and the feedback control is performed by outputting the operation amount calculated in step S2 to the drive circuit 82 as the final operation amount. Do.

  Thereby, the rotational speed of the motor is quickly converged to the target rotational speed (target motor current) with an appropriate response characteristic, and the hydraulic pressure of the forward / reverse switching mechanism 3 is restarted by the hydraulic oil supplied from the electric oil pump 8. Maintains more than hydraulic pressure. As a result, at the time of restart, the engagement shock of the forward clutch of the forward / reverse switching mechanism 3 is sufficiently mitigated, and the battery voltage is also prevented from being lowered, restartability is ensured, and smooth restart can be performed.

  Further, when it is determined in step S4 that the actual power supply current Ib exceeds the first limit value Ib1, the process proceeds to step S6, and whether the operation amount calculated in step S3 has increased from the operation amount calculated last time. judge.

  If it is determined that the operation amount has increased, the process proceeds to step S7, where the final operation amount is set to be maintained at the previously calculated operation amount. When it is determined in step S6 that the operation amount has not increased, the process proceeds to step S8, where the operation amount calculated this time is set as the final operation amount. In this way, an increase in the operation amount is prohibited. The operation amount set in step S7 or step S8 is output in step S5.

  Thus, by prohibiting the increase in the operation amount when the power supply current Ib exceeds the first limit value Ib1, it is possible to limit the power supply current Ib from increasing. As a result, the hydraulic pressure for restart can be ensured by raising the motor to a required rotational speed (required motor current) or more while suppressing power consumption to a minimum.

  FIG. 9 shows the difference in action depending on whether or not there is a limit by the first limit value Ib1.

  As described above, there is a variation in the required rotation speed (required motor current) of the motor that can ensure the restart hydraulic pressure due to individual pump differences, and in order to ensure the restart hydraulic pressure in any pump, The target rotational speed (target motor current) is set higher than the maximum required rotational speed (required motor current) of the pump having the highest required rotational speed (required motor current).

  In addition, the power consumption that can secure the restart hydraulic pressure is increased because the pump with a higher required rotational speed (required motor current) needs to have a higher rotational speed (motor current) than the pump with a lower required rotational speed. To do.

  On the other hand, compared with the case where the motor is rotated at the target rotational speed (target motor current), the pump with the lower required rotational speed (required motor current) requires the required speed than the pump with the higher required rotational speed (required motor current). Since the increase from the number (required motor current) to the target rotational speed (target motor current) is large, the hydraulic pressure rises higher than the restart hydraulic pressure. That is, a pump with a lower required rotational speed (required motor current) requires more work than a pump with a higher required rotational speed (required motor current), so that power consumption increases.

  Therefore, when a pump motor having a particularly low required rotational speed (required motor current) is feedback controlled to the target rotational speed (target motor current) without being limited by the first limit value Ib1 of the power supply current, as shown by a dotted line in FIG. The actual power supply current may exceed the first limit value Ib1 and the power consumption may be greatly impaired.

  On the other hand, in the present embodiment, the power source current Ib is limited by the first limit value Ib1 for a pump motor having a low required rotational speed (required motor current) as shown by a solid line in FIG. The motor rotation speed (motor current) decreases from the target rotation speed (target motor current), but exceeds the required rotation speed (required motor current) of the pump. For this reason, while the restarting hydraulic pressure can be ensured, an excessive increase in the rotational speed is suppressed and power consumption loss can be suppressed.

  In this way, by performing the restriction with the first limit value Ib1, even if there is a difference between individual pumps, the restart hydraulic pressure can be ensured at a required rotational speed (necessary motor current) or more with the minimum power consumption, and the fastening shock Can be sufficiently relaxed.

  Note that power consumption can be minimized by performing feedback control using the hydraulic oil supply amount equivalent to the restart hydraulic pressure as a target value for each pump while detecting the hydraulic oil supply amount from the electric oil pump. Considering response delays due to supply volume detection delays, implementation costs, etc., the feasibility is poor. In this regard, in the present embodiment, by performing the restriction by the limit value of the power supply current Ib, it is possible to obtain the effect of ensuring the restart hydraulic pressure while reducing the power consumption.

  In addition, since the power supply current Ib is maintained in the vicinity of the first limit value Ib1, it is needless to say that a decrease in battery voltage can be suppressed and restartability can be ensured.

  On the other hand, at the time of an abnormality in which the motor rotation resistance of the electric oil pump constantly or temporarily increases, even if the control for prohibiting the increase in the operation amount is performed, the current further increases and exceeds the second limit value Ib2. Sometimes.

  In such a case, it is determined in step S2 that the power supply current Ib exceeds the second limit value Ib2, and the process proceeds to step S9.

  In step S9, the operation amount is calculated as follows so as to forcibly reduce the power supply current Ib in accordance with the excess current amount.

  First, an excess current amount ΔIb with respect to the second limit value Ib2 of the power supply current Ib is calculated by the following equation (1).

ΔIb2 (> 0) = Ib−Ib2 (1)
Next, an operation amount reduction amount for reducing the power supply current Ib is calculated by the following equation (2).

Manipulation amount reduction amount = ΔIb2 × gain (> 0) (2)
Finally, the previous operation amount is corrected by the operation amount reduction amount, and the current operation amount is calculated by the following equation (3).

Operation amount = previous operation amount−operation amount reduction amount (3)
The operation amount calculated in step S9 is output in step S5.

  In this way, by controlling the amount of operation to reduce the power supply current Ib, it is possible to limit the power supply current Ib so as not to exceed the second limit value Ib2. The decrease is suppressed, and restartability can be secured.

  In the case of an abnormality in which the rotational resistance temporarily increases due to a foreign object, normally, as shown in FIG. 10, if the foreign object is detached from the rotating part or sliding part of the motor, the rotational resistance is reduced and the subsequent rotation increases. Thus, the restarting hydraulic pressure can be secured exceeding the required rotational speed.

  Further, when the motor rotation resistance is constantly large, as shown in FIG. 10, the rising speed of the power supply current Ib is large, exceeding the first limit value Ib1, and further exceeding the second limit value Ib2. Thereafter, it may be constantly maintained in the vicinity of the second limit value Ib2.

  In this case, if the degree of abnormality (rotational resistance level) is slight, a motor rotational speed higher than the necessary rotational speed is secured, and the driving force transmission shock at the time of restart may be sufficiently mitigated. Even when the required rotational speed is not reached, the power supply current Ib is maintained in the vicinity of the second limit value Ib2, so that the motor rotational speed is increased as much as possible while ensuring restartability, thereby reducing the fastening shock. can do.

  Further, when the pump individual difference is particularly large, the power supply current Ib may reach the second limit value Ib2 even if it is limited by the first limit value Ib1. In this case, since the power supply current Ib increases to a second limit value Ib2 that is larger than the first limit value Ib1, naturally the restart hydraulic pressure is ensured, and both avoidance of fastening shock and ensuring restartability can be achieved.

  By the way, when feedback control is performed using the motor current as a target value, the motor current also increases with the power supply current when there is a constant increase in rotational resistance. Therefore, when the motor current is increased to the target motor current, It becomes lower than the rotation speed. In other words, compared to the case where feedback control is performed with the motor rotation speed as a target value, the rotation speed tends to be less likely to increase. However, when such a constant increase in rotation resistance occurs, the power supply current is excessive due to securing the motor rotation speed. Priority should be given to restraining this increase. Even when feedback control is performed using the motor current as a target value, there is no particular problem because the second limit value Ib2 does not change the excessive increase in the current.

  Next, a second embodiment will be described.

  FIG. 4 is a flowchart of control according to the second embodiment.

  Steps S1 and S2 are the same as in the first embodiment.

  When the process proceeds from step S2 to step S4 and it is determined that the actual power supply current Ib is equal to or smaller than the first limit value Ib1, the operation amount is calculated and set by PID control or the like using a normal control gain in step S3. Thereafter, the manipulated variable is output in step S5.

  Thus, normal feedback control is performed as in the first embodiment, and the control amount can be converged to the target value by increasing the hydraulic pressure with optimum responsiveness.

  If it is determined in step S2 that the actual power supply current Ib exceeds the second limit value Ib2, the operation amount for excess current is calculated in step S9, and the operation amount is output in step S5. To do. As a result, the control for maintaining the power supply current Ib so as not to exceed the second limit value Ib2 is performed in the same way as in the first embodiment in the event of an abnormality in which the rotational resistance increases temporarily or constantly, and the battery at the time of restart It is possible to secure a good restartability by suppressing a decrease in the voltage VB.

  On the other hand, when it is determined in step S4 that the actual power supply current Ib exceeds the first limit value Ib1, the process proceeds to step S6.

  In step S6, it is determined whether the target values such as the motor rotation speed and the motor current are larger than the control amount, that is, whether the control in the direction to increase the power supply current Ib is performed to increase the control amount to approach the target value. .

  If it is determined in step S6 that the target value is larger than the control amount, that is, the control in the direction of increasing the power supply current Ib is performed, the process proceeds to step S7, and the control gain in the direction of increasing the power supply current Ib is decreased. to correct.

  Next, the process proceeds to step S3, where the manipulated variable in the direction of current increase is calculated using the control gain corrected for decrease, and the manipulated variable is output in step S5.

  When it is determined in step S6 that the target value is equal to or less than the control amount, that is, during control in a direction in which the power supply current Ib is not increased, the process proceeds to step 3 and the operation amount is set using a normal control gain.

  If the increase in current is prohibited, the power consumption is minimized, but the response speed becomes slow, so the idle operation time from the start of engine idle stop control until the restart hydraulic pressure is secured and the idle operation is stopped. Prolongs the fuel consumption.

  Therefore, in the present embodiment, when the power supply current Ib exceeds the first limit value Ib1, the increase is allowed while the increase rate is slower than usual without prohibiting the increase in current. As a result, it is possible to quickly increase the hydraulic pressure of the speed change mechanism and save the restart hydraulic pressure in a short time while reducing power consumption.

  Accordingly, it is possible to secure the effect of reducing the engagement shock at the time of restart, and to shorten the idle operation time of the engine and reduce the fuel consumption. The engine may be stopped by detecting that the oil pressure has increased to the restarting oil pressure. However, the time until the restarting oil pressure is secured after starting the driving of the electric oil pump in advance may be an experiment or a simulator. In this case, simple control for stopping the engine operation after the lapse of time may be used.

  Hereinafter, the third to fifth embodiments show a case where the limitation of the power supply current Ib is started after a predetermined time has elapsed after the actual power supply current Ib exceeds the first limit value Ib1.

  In the third embodiment, in the same control as in the first embodiment, the control for prohibiting the increase in the operation amount is started after a predetermined time has passed after the actual power supply current Ib exceeds the first limit value Ib1.

  FIG. 5 is a flowchart of control according to the third embodiment.

  As in FIG. 3, the process proceeds to step S1 to step S4. When it is determined in step S4 that the actual power supply current Ib exceeds the first limit value Ib1, the process proceeds to step S21, and whether this state has elapsed for a predetermined time. judge. Here, the predetermined time is set to a value slightly larger than the response time of the feedback control of the normal pump (time until the control amount reaches the target value when the target value is changed in steps).

  Then, before the predetermined time elapses when the actual power supply current Ib exceeds the first limit value Ib1, the process directly proceeds to step S5, the operation amount calculated in step S3 is output, and normal feedback control is continued. Done.

  On the other hand, after it is determined in step S5 that the state where the actual power supply current Ib exceeds the first limit value Ib1 has passed the predetermined time, the process proceeds to step S6 and subsequent steps, and control for prohibiting the increase in the operation amount is started. The

  As described above, in order to ensure the responsiveness of the electric oil pump (motor), it is desirable to allow the power supply current Ib to exceed the first limit value Ib1 to some extent. In particular, at the time of start-up immediately after the motor is turned on, the power supply current Ib increases beyond the steady state, and there is a demand for improving the responsiveness by allowing such an increase in current as much as possible.

  On the other hand, after a predetermined time exceeding the response time has passed and the steady state is reached, if the power supply current Ib is maintained at the first limit value Ib1 or more except during an abnormality, the required rotational speed can be obtained and the restart hydraulic pressure can be obtained. Is secured.

  Therefore, when the power supply current Ib exceeds the first limit value Ib1 after the predetermined time has elapsed, the increase in the operation amount is prohibited to restrict the power supply current Ib from increasing, thereby suppressing excessive power consumption.

  By adopting such a configuration, an increase in the rising of the power supply current Ib is allowed before a predetermined time elapses, thereby improving the responsiveness of the electric oil pump and promptly increasing the hydraulic pressure of the transmission mechanism after the start of engine idle stop control. It is possible to raise the oil pressure to restart. Thereby, the fastening shock at the time of restart can be reduced well, and the idle operation time of the engine can be sufficiently shortened to improve the fuel consumption.

  On the other hand, after the elapse of a predetermined time, the increase in the power supply current Ib can be prohibited to save power consumption, as in the first embodiment.

  In addition, as in the first and second embodiments, the normal feedback control can be performed when the power supply current Ib is equal to or less than the first limit value Ib1 to increase the hydraulic pressure with optimum response.

  Similarly, when the power supply current Ib exceeds the second limit value Ib2, control for reducing the power supply current Ib is performed to suppress the battery voltage drop and to ensure restartability, as in the first and second embodiments. It is.

  FIG. 11 shows a state change during control according to this embodiment.

  FIG. 6 is a flowchart of control according to the fourth embodiment.

  As in the third embodiment, normal feedback control is performed before the actual power supply current Ib exceeds the first limit value Ib1 for a predetermined time, and the increase of the power supply current Ib is not limited (the third embodiment) Steps S1 to S4 → S21 → S5).

  Therefore, as in the third embodiment, the responsiveness of the electric oil pump can be increased as much as possible, the hydraulic pressure of the transmission mechanism can be quickly increased to the restart hydraulic pressure, and the fastening shock at the time of restart can be reduced well. At the same time, the idle operation time of the engine can be sufficiently shortened to improve fuel efficiency.

  On the other hand, when it is determined in step S21 that the state where the actual power supply current Ib exceeds the first limit value Ib1 has passed the predetermined time, the process proceeds to step S22, and the operation amount is reduced according to the excess current amount. Control for forcibly reducing the current Ib is performed. The manipulated variable reduction control is performed as follows similarly to the calculation performed in step S9.

  The excess current amount ΔIb1 of the power supply current Ib with respect to the first limit value Ib1 is calculated by the following equation (4).

ΔIb1 (> 0) = Ib−Ib1 (4)
Next, an operation amount reduction amount for reducing the power supply current Ib is calculated by the following equation (5).

Manipulation amount reduction amount = ΔIb1 × gain (> 0) (5)
Finally, the previous operation amount is corrected by the operation amount reduction amount, and the current operation amount is calculated by the following equation (6).

Operation amount = previous operation amount−operation amount reduction amount (6)
The operation amount calculated in step S22 is output in step S5.

  In the fourth embodiment, when the power supply current Ib exceeds the first limit value Ib1 even after a lapse of a predetermined time, the power supply current Ib is reduced and forcibly reduced to the first limit value Ib1. The power saving function can be further enhanced.

  In addition, as in the first to third embodiments, the normal feedback control can be performed when the power supply current Ib is equal to or less than the first limit value Ib1 to increase the hydraulic pressure with optimum responsiveness.

  Similarly, when the power supply current Ib exceeds the second limit value Ib2, control for reducing the power supply current Ib to ensure restartability is performed as in the first to third embodiments (step S1 → S2 → S9 → S5).

  FIG. 12 shows a state change during control according to the present embodiment.

  In the fifth embodiment, in the same control as in the second embodiment, the control for decreasing the control gain is started during the current increasing direction control after a predetermined time has elapsed after the actual power supply current Ib exceeds the first limit value Ib1. To do.

  FIG. 7 is a flowchart of control according to the fifth embodiment.

  Before the predetermined time elapses when the actual power supply current Ib exceeds the first limit value Ib1, normal feedback control is performed, and the increase of the power supply current Ib is not limited as in the third and fourth embodiments. (Steps S1, S2, S4, S21, S3, S5).

  As a result, as in the third and fourth embodiments, the responsiveness of the electric oil pump can be increased as much as possible, and the hydraulic pressure of the transmission mechanism can be quickly increased to the restart hydraulic pressure. In addition to being able to reduce well, the engine idle time can be sufficiently shortened to improve fuel efficiency.

  Similarly, when the power supply current Ib exceeds the second limit value Ib2, control for reducing the power supply current Ib is performed to ensure restartability as in the first to fourth embodiments (step S1 → S2 → S9 → S5).

  On the other hand, when it is determined in step S21 that the state in which the actual power supply current Ib exceeds the first limit value Ib1 has passed the predetermined time, the process proceeds to step S6 and subsequent steps, and control in the current increasing direction in which the target value exceeds the control amount. Only when the control is performed, the control amount is decreased, the operation amount is calculated and set, and the control for suppressing the increase in current is started.

  Hereinafter, operations and effects unique to the fifth embodiment will be described.

  As in the third and fourth embodiments, the power consumption is reduced by starting the limit by the first limit value Ib1 after a predetermined time has elapsed since the actual power supply current Ib exceeds the first limit value Ib1. . However, when an abnormality that temporarily increases the motor rotation resistance occurs within a predetermined time, due to a rapid decrease in the motor rotation speed, if the limit by the first limit value Ib1 is too strong, the rotation speed is delayed. May cause responsiveness to deteriorate.

  In the present embodiment, after a predetermined time has elapsed, the control gain in the direction of increasing the power supply current Ib is decreased, but the increase in the power supply current Ib is set as a weak limit, so that responsiveness can be achieved even when the motor rotation resistance temporarily increases. Can be secured. In addition, by limiting the control gain, the increase rate of the power supply current Ib can be delayed to prevent the second limit value Ib2 from being exceeded, and the restart can be performed while saving power consumption and suppressing the battery voltage from decreasing. Sex can be secured.

  FIG. 13 shows a state change at the time of control according to the present embodiment when the motor rotation resistance is temporarily increased.

  Next, a sixth embodiment will be described.

  In the present embodiment, the third limit value Ib3 is set between the first limit value Ib1 and the second limit value Ib2. As in the third to fifth embodiments, before the predetermined time elapses when the power supply current Ib exceeds the first limit value Ib1, the increase in current is not basically started. In particular, when the power supply current Ib exceeds the third limit value Ib3, the increase in current is limited.

  FIG. 8 is a flowchart of the sixth embodiment.

  As in the third embodiment, in step S1 to step S4, after it is determined that the power supply current Ib exceeds the first limit value Ib1 (however, less than the second limit value Ib2), the process proceeds to step S31. It is determined whether the current Ib exceeds the third limit value Ib3.

  If it is determined that the third limit value Ib3 is not exceeded, the process proceeds to step S21 and the subsequent steps. Before the power supply current Ib exceeds the first limit value Ib1, the limit of the power supply current Ib is not exceeded. Without performing the control, the control for prohibiting the increase in the operation amount is started after the predetermined time is exceeded.

  As a result, as in the third to fifth embodiments, the responsiveness of the electric oil pump can be increased as much as possible, and the hydraulic pressure of the transmission mechanism can be quickly increased to the restart hydraulic pressure. In addition to being able to reduce well, the engine idle time can be sufficiently shortened to improve fuel efficiency.

  Similarly, when the power supply current Ib exceeds the second limit value Ib2, control for reducing the power supply current Ib to ensure restartability is performed as in the first to fifth embodiments (step S1 → S2 → S9 → S5).

  On the other hand, when it is determined in step S31 that the power supply current Ib exceeds the third limit value Ib3, the process bypasses step S6 and proceeds to step S7 and subsequent steps, and immediately executes control for prohibiting an increase in the operation amount.

  When the motor rotation speed rapidly decreases due to a temporary increase in rotational resistance, the power supply current Ib may increase rapidly and greatly exceed the second limit value Ib2. In this case, even if the operation amount is reduced after the second limit value Ib2 is exceeded, it is difficult to quickly limit the power supply current Ib to the second limit value Ib2 or less because of a response delay.

  The present embodiment copes with such a situation. When the power supply current Ib exceeds the third limit value Ib3, the increase in the operation amount is prohibited and the power supply current Ib is prevented from exceeding the second limit value Ib2. As a result, power consumption can be reduced as much as possible.

  FIG. 14 shows a state change during control according to the present embodiment when a temporary increase in motor rotation resistance occurs.

  In the present embodiment, an example is shown in which an increase in the operation amount is prohibited when the power supply current Ib exceeds the first limit value Ib1 after a predetermined time has elapsed, but the operation amount is reduced as shown by a one-dot chain line. Thus, the power supply current Ib may be reduced to the first limit value Ib1, or the control gain in the direction of increasing the power supply current may be reduced.

  The same applies to the limitation of the power supply current Ib when the power supply current Ib exceeds the third limit value Ib3 within a predetermined time, and may be replaced with a decrease in the operation amount and a decrease in the control gain in the current increasing direction.

  The embodiment described above is applied to a transmission mechanism having a starting clutch mechanism and a continuously variable transmission, but may be applied to a stepped automatic transmission. In this case, the same effect can be obtained by applying the present invention when controlling the engagement hydraulic pressure of the clutch mechanism of the transmission element in the automatic transmission to the restart hydraulic pressure by the hydraulic oil supplied from the electric oil pump. .

  Further, there is an engine automatic stop control that automatically stops the operation of the engine when the brake operation is performed at a reduced vehicle speed when the vehicle is decelerated and the engine is restarted when the brake operation is released and the accelerator operation is performed. The present invention can be applied to such a control that ensures the operating oil pressure of the transmission mechanism to be equal to or higher than the restart oil pressure by the electric oil pump during the engine automatic stop control, and the same effect can be obtained.

  Further, technical ideas other than the claims that can be grasped from the above embodiment will be described together with the effects thereof.

(I)
4. The electric oil pump control device according to claim 1, wherein the first limit value is set to a smaller value when the power supply voltage of the drive circuit is high than when the power supply voltage is low.

  The driving power of the motor required for generating the restart hydraulic pressure is determined by the product of the power supply voltage and the power supply current of the drive circuit. When the power supply voltage of the drive circuit is high (low), the required power supply current is small. Therefore, the first limit value can be set to a small value (need to be set to a large value).

  Therefore, with the configuration (a), the first limit value can be set to an appropriate value without excess or deficiency.

(B)
4. The electric oil pump control device according to claim 1, wherein the first limit value is higher when the power supply voltage of the drive circuit is high than when it is low. Set to

  When the power supply voltage is high (low), the voltage drop when the same power supply current is energized and consumed is small (large), and the allowable current, that is, the second limit value Ib2 can be set large (set small). There is a need).

  Therefore, with the above configuration (b), the second limit value can be set to an appropriate value without excess or deficiency.

(C)
In the control apparatus for an electric oil pump according to any one of claims 1 to 3, or (A), (B), the control for suppressing an increase in power supply current by the first power supply current limiting means is as follows. This is a control that prohibits an increase in power supply current.

  With the configuration (c), after the power supply current exceeds the first limit value, an increase in current is further suppressed, so that power consumption corresponding to the suppression can be saved.

(D)
In the control apparatus for an electric oil pump according to any one of claims 1 to 3, or (A), (B), the control for suppressing an increase in power supply current by the first power supply current limiting means is as follows. This control reduces the power supply current.

  With the configuration (d), when the power supply current exceeds the first limit value, the power supply current can be reduced to the first limit value by the control for reducing the power supply current, and the power consumption can be further reduced.

(E)
In the control apparatus for an electric oil pump according to any one of claims 1 to 3, or (A), (B), the control for suppressing an increase in power supply current by the first power supply current limiting means is as follows. In this control, the control gain in the direction of increasing the power supply current is decreased.

  With the configuration of (e), when the power supply current exceeds the first limit value, the control gain in the direction of increasing the power supply current can be reduced, and the power consumption can be reduced by reducing the increase speed of the power supply current. By allowing the increase to some extent, the responsiveness can be improved and the hydraulic pressure for restart can be quickly approached. Therefore, the engine can be automatically stopped quickly, the engine operation time can be shortened, and fuel consumption can be improved.

(F)
The control device for an electric oil pump according to any one of claims 1 to 3, or (a) to (e), wherein a power supply current is made not more than the second limit value by the second power supply current limiting means. The control to maintain is control to reduce the power supply current.

  With the configuration of (f), when the power supply current exceeds the second limit value, the power supply current can be reduced to the second limit value by the control for reducing the power supply current, and the drive voltage drop can be sufficiently suppressed. Restartability can be ensured.

(G)
In the control apparatus for an electric oil pump according to any one of claims 1 to 3, or (a) to (f), the motor is feedback-controlled using the motor rotation speed as a target value.

  With the configuration (G), it is possible to perform good control by setting, as a target value, the motor rotation number at which the hydraulic pressure supplied from the electric oil pump can be maintained at or above the restart hydraulic pressure.

(Chi)
In the control apparatus for the electric oil pump according to any one of claims 1 to 3, or (a) to (f), the motor is feedback-controlled using a motor current as a target value. With this configuration, it is possible to perform favorable control by setting, as a target value, a motor current capable of obtaining a motor rotational speed capable of maintaining the hydraulic pressure supplied from the electric oil pump at or above the restart hydraulic pressure.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 3 ... Forward / reverse switching mechanism, 4 ... Continuously variable transmission, 5 ... CVT control unit, 6 ... Pressure regulation mechanism, 7 ... Mechanical oil pump, 8 ... Electric oil pump, 20 ... Transmission mechanism, 51 ... Target value calculation unit 52 ... Feedback controller 53 ... Current sensor 81 ... Motor 82 ... Drive circuit

Claims (3)

A control device for an electric oil pump that maintains an operating oil pressure of a speed change mechanism connected to the engine at a level higher than a restart oil pressure by an oil pressure supplied from the electric oil pump during automatic engine stop control of the engine,
Power supply current detection means for detecting a power supply current of a drive circuit of a motor that drives the electric oil pump;
First limit value setting means for setting a first limit value of the power supply current based on driving power of the motor necessary for generating the restart hydraulic pressure;
Second limit value setting means for setting a second limit value larger than the first limit value as the allowable limit of the power supply current;
First power supply current limiting means for controlling to suppress an increase in the power supply current when the power supply current value detected by the power supply current detection means exceeds the first limit value and is less than the second limit value;
Second power supply current limiting means for controlling the power supply current to be kept below the second limit value when the power supply current value detected by the power supply current detection means exceeds the second limit value;
An electric oil pump control device comprising:   2. The electric oil pump according to claim 1, wherein the first power supply current limiting unit starts the control for suppressing the increase in the power supply current with a delay of a predetermined time after the power supply current value exceeds the first limit value. Control device.   When a third limit value is set as an intermediate value between the first limit value and the second limit value, and the power supply current exceeds the third limit value, the power supply current even before the predetermined time has elapsed. 3. The control device for an electric oil pump according to claim 2, further comprising third power supply current limiting means for performing control to limit the power.

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