JP5095810B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device including an electric oil pump that is driven when an engine is stopped.

  Some vehicles perform so-called idle stop, in which fuel supply is stopped and the engine is automatically stopped under predetermined conditions such as when the vehicle is stopped, for the purpose of improving fuel consumption and reducing exhaust gas. Normally, in a vehicle equipped with an engine, the hydraulic pressure of the transmission is secured by a mechanical oil pump driven by the engine. However, in the case of a vehicle that performs automatic engine stop control, the mechanical oil pump is Since the hydraulic pressure cannot be ensured because it stops, an electric oil pump is provided to ensure the hydraulic pressure at this time.

  In Patent Document 1, only the mechanical oil pump is driven when the engine speed is equal to or higher than a predetermined value, and the electric oil pump is driven in addition to the mechanical oil pump when the engine speed is equal to or lower than the predetermined value. A technique for driving only the above is disclosed.

JP 2000-46166 A

By the way, although the discharge capacity of the mechanical oil pump depends on the engine speed, the viscosity decreases as the oil temperature of the hydraulic oil rises. Therefore, if the oil temperature is high even at the same engine speed, the discharge pressure of the mechanical oil pump Becomes lower.
Therefore, if the electric oil pump is stopped due to the engine speed exceeding a predetermined value during the automatic engine start after the automatic engine stop, when the oil temperature is high, the discharge pressure of the mechanical oil pump is increased at that engine speed. May not be able to supply a stable hydraulic pressure to the transmission.

In addition, when the electric oil pump is started by automatic engine stop, it takes time to increase the discharge pressure of the electric oil pump when the oil temperature is high, and the transmission is stable in time for changing to the discharge pressure of the mechanical oil pump. The supplied hydraulic pressure may not be supplied.
If stable hydraulic pressure cannot be supplied to the transmission, there is a possibility that the clutch engagement state in the transmission cannot be kept stable.
Therefore, the present invention controls a vehicle that can supply a stable hydraulic pressure to the transmission even when the engine is stopped or the engine is restarted by changing the driving conditions of the electric oil pump according to the oil temperature of the hydraulic oil. A device is provided.

The vehicle control apparatus according to the present invention employs the following means in order to solve the above problems.
According to the first aspect of the present invention, driving force generating means including at least an engine (for example, an engine 2 and a motor / generator 3 in an embodiment described later) and a driving force generated by the driving force generating means are shifted and driven. A transmission (for example, a transmission 6 in an embodiment described later) that transmits to wheels (for example, a driving wheel W in an embodiment described later), and a mechanical oil that is driven by the driving force generating means and supplies hydraulic pressure to the transmission. A pump (for example, a mechanical oil pump 11 in an embodiment to be described later) and an electric oil pump that is activated when the engine is stopped and supplies hydraulic pressure to the transmission and stops when the engine is started (for example, in an embodiment to be described later) Electric oil pump 12) and oil temperature detecting means (for example, described later) for detecting the oil temperature of the hydraulic oil supplied to the transmission In the control device of a vehicle (for example, a hybrid vehicle 1 in an embodiment to be described later) that automatically stops and starts the engine under a predetermined condition, the oil temperature detecting means detects the oil temperature sensor 38) in the embodiment. The driving pressure of the electric oil pump is increased as the oil temperature is increased, and when the oil temperature detecting means fails, control on the higher temperature side than the standard oil temperature is executed. It is a control device.

  The invention according to claim 2 is the invention according to claim 1, wherein when the predetermined condition for restarting the engine is satisfied, the higher the oil temperature detected by the oil temperature detection means, the higher the temperature of the electric oil pump. The stop timing is delayed.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the higher the oil temperature detected by the oil temperature detecting means, the higher the predetermined condition for automatically stopping the engine. The start timing of the electric oil pump is advanced.

According to the first aspect of the present invention, when the electric oil pump is started when the engine is stopped when the hydraulic oil temperature is high and the viscosity is low, the discharge pressure increase of the electric oil pump can be accelerated. Thus, the decrease in the discharge pressure of the mechanical oil pump accompanying the decrease in the engine speed can be compensated by the discharge pressure of the electric oil pump, and the operating hydraulic pressure of the transmission can be ensured at a predetermined value or more.
In addition, when the electric oil pump is stopped when the engine is restarted, the decrease in the drive pressure of the electric oil pump can be delayed, and the delay in the increase in the discharge pressure of the mechanical oil pump due to the decrease in the hydraulic oil viscosity It can be compensated by the discharge pressure of the oil pump, and the hydraulic pressure of the transmission can be ensured at a predetermined value or more.
As a result, regardless of the temperature of the hydraulic oil, the hydraulic pressure of the transmission can be secured above a predetermined value when the engine is stopped and restarted, and the mechanical oil pump and electric oil pump that accompany the engine stop or restart Since the stable hydraulic pressure can be supplied to the transmission at the time of switching, the clutch engagement state in the transmission can be kept stable.
Furthermore, the drive pressure of the electric oil pump is set so that stable hydraulic pressure can be supplied to the transmission even when the oil temperature of the transmission is unknown due to failure of the oil temperature detection means. be able to.

According to the second aspect of the present invention, even when the hydraulic oil temperature is high and the viscosity is reduced when the engine is restarted, the delay in the discharge pressure increase of the mechanical oil pump accompanying the decrease in viscosity is reduced. It can be compensated by the discharge pressure, and the operating hydraulic pressure of the transmission can be secured above a predetermined value.
As a result, since stable hydraulic pressure can be supplied to the transmission, the clutch engagement state in the transmission can be kept stable.

According to the invention of claim 3, even when the temperature of the hydraulic oil is high and the viscosity is low when the engine is stopped, the discharge pressure drop of the mechanical oil pump accompanying the decrease in the engine speed is reduced. The pressure can be supplemented, and the hydraulic pressure of the transmission can be ensured to be a predetermined value or more.
As a result, since stable hydraulic pressure can be supplied to the transmission, the clutch engagement state in the transmission can be kept stable.

It is a schematic block diagram of the power transmission system in the vehicle provided with the control apparatus which concerns on this invention. It is a hydraulic-oil supply circuit diagram of the transmission in the said vehicle. It is a flowchart which shows starting control of the electric oil pump in the reference example of the technique relevant to the control apparatus of the vehicle which concerns on this invention. It is a flowchart which shows stop control of the electric oil pump in the reference example of the technique relevant to the control apparatus of the vehicle which concerns on this invention. It is a time chart at the time of starting and a stop of the electric oil pump of the reference example. It is an EOP starting vehicle speed map in the reference example. It is an EOP stop delay time map in the reference example. It is a flowchart which shows the drive pressure determination process of the electric oil pump in the Example of the control apparatus of the vehicle which concerns on this invention. It is a time chart at the time of starting of the electric oil pump of the said Example, and a stop. It is an EOP drive pressure map in the said Example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a vehicle control apparatus according to the present invention will be described below with reference to the drawings of FIGS.
FIG. 1 is a schematic configuration diagram of a power transmission system of a hybrid vehicle 1 including a control device according to the present invention.
In this hybrid vehicle 1, an engine 2 and a motor (hereinafter referred to as “motor / generator”) 3 that can generate power are directly connected, and at least one of the power of the engine 2 and the motor / generator 3 is torque provided with a lock-up clutch 4. The power is transmitted to the output shaft 6a via the converter 5 and the multi-stage automatic transmission 6, and is transmitted from the output shaft 6a to the drive wheels W of the vehicle via a differential mechanism (not shown). In this embodiment, the engine 2 and the motor / generator 3 constitute driving force generating means.

  The engine 2 is a multi-cylinder reciprocating engine, and includes a fuel injection / ignition control device 7 that performs fuel injection control and injection fuel ignition control for each cylinder. In this embodiment, an electronically controlled throttle system (so-called drive-by-wire system, abbreviated as DBW system) is employed, and the operation of the throttle valve (not shown) of the engine 2 is performed by depressing the accelerator pedal. Electronic control is performed by the ECU 8 based on the amount.

  The operation of the fuel injection / ignition control device 7 is controlled by the ECU 8, and automatic stop / start control of the engine 2 is performed under predetermined conditions. Therefore, the ECU 8 includes a brake switch (brake depression detection means) 16 that detects whether or not the brake pedal has been depressed, an accelerator pedal sensor 17 that detects the amount of depression of the accelerator pedal, and an engine rotation that detects the number of revolutions of the engine 2. An output signal is input from a number sensor (engine speed detection means) 18, an output shaft speed sensor 19 for detecting the speed of the output shaft 6a of the transmission 6, and the like. In this embodiment, the speed of the vehicle (that is, the vehicle speed V) is calculated based on the rotational speed of the output shaft 6 a detected by the output shaft rotational speed sensor 19. In this embodiment, the fuel injection / ignition control device 7 and the ECU 8 that controls the fuel injection / ignition control device 7 constitute an engine automatic stop / starting means.

  The torque converter 5 transmits torque between the output shaft of the motor / generator 3 and the input shaft of the transmission 6 through a fluid in a state in which the lock-up clutch 4 is released. When engaged, the output shaft of the motor / generator 3 and the input shaft of the transmission 6 are substantially directly connected, and torque is transmitted directly between the output shaft and the input shaft regardless of the fluid. Done. Engagement / release of the lockup clutch 4 and shifting of the transmission 6 are performed by hydraulic control in the hydraulic control circuit 20 in accordance with the driving state of the vehicle.

  In this hybrid vehicle 1, when driving force is transmitted from the driving wheel W side to the motor / generator 3 side during deceleration, the motor / generator 3 performs a regenerative operation to recover the kinetic energy of the vehicle body as electric energy, The battery 10 can be charged (energy recovery) through the power drive unit (PDU) 9. Power running and regeneration of the motor / generator 3 are controlled by the ECU 8 via the PDU 9. A capacitor may be used instead of the battery 10.

  The hybrid vehicle 1 also includes a mechanical oil pump 11 and an electric oil pump 12 having a smaller capacity than the mechanical oil pump 11 as a hydraulic pressure supply source to the hydraulic control circuit 20. The mechanical oil pump 11 is connected to the output shaft of the engine 2 and is operated by the driving force of the engine 2 or the motor / generator 3.

  On the other hand, the electric oil pump 12 is operated by an electric motor (drive motor) 13, and the pump driver 14 supplies the electric power of the 12-volt battery 15 to the electric motor 13. The electric oil pump 12 is basically controlled to operate when the engine 2 and the motor / generator 3 are stopped and the mechanical oil pump 11 cannot be operated. That is, the ECU 8 starts the electric motor 13 via the pump driver 14 when the engine 2 stop condition is satisfied, starts the electric oil pump 12, and the pump driver 14 when the engine 2 restart condition is satisfied. Then, the electric motor 13 is stopped and the electric oil pump 12 is stopped. In this embodiment, the engine 2 is stopped when the brake switch is “ON”, the vehicle speed V is less than the engine stop permission vehicle speed VENGST (for example, 15 km / hr), the accelerator pedal depression amount is “0”, etc. When the engine 2 is satisfied, the restart condition of the engine 2 is when the brake switch is “OFF” and the amount of depression of the accelerator pedal satisfies a predetermined value or more.

A hydraulic circuit (hydraulic supply unit) 30 that supplies hydraulic pressure to the transmission 6 will be described with reference to FIG. The suction port 11 a of the mechanical oil pump 11 is connected to a strainer 32 disposed in the oil pan 31 by a suction pipe 33, and the discharge port 11 b of the mechanical oil pump 11 is connected to the hydraulic control circuit 20 by a discharge pipe 34.
The suction port 12 a of the electric oil pump 12 is connected to the suction pipe 33 by the suction pipe 35, and the discharge port 12 b of the electric oil pump 12 is connected to the discharge pipe 34 by the discharge pipe 36. The discharge pipe 36 is provided with a check valve 37 that permits the flow of hydraulic oil from the discharge port 12b of the electric oil pump 12 toward the discharge pipe 34 and prevents the flow of hydraulic oil from the discharge pipe 34 toward the discharge port 12b. It has been.

As is well known, the hydraulic control circuit 20 is operated in conjunction with a shift lever in the driver's seat and is operated by a manual valve (not shown) that switches hydraulic oil supplied from the discharge pipe 34 to basic oil paths for forward, neutral and reverse. 2), a plurality of shift valves (not shown) for controlling the oil passage and hydraulic pressure of the hydraulic oil supplied from the discharge pipe 34, a plurality of solenoid valves 21 for controlling the pilot pressure of the shift valve, and the like. The operation of the clutch and brake (not shown) of the transmission 6 is controlled by controlling the oil passage and hydraulic pressure with a shift valve according to the driving state of the vehicle, and the gear position of the transmission 6 is adjusted. It enables automatic optimal control automatically.
Further, the transmission 6 is provided with an oil temperature sensor (oil temperature detecting means) 38 for detecting the temperature of the hydraulic oil supplied to the transmission 6 (that is, the hydraulic oil temperature). Outputs an electric signal corresponding to the detected hydraulic oil temperature to the ECU 8.

Before describing the control of the electric oil pump in the vehicle control apparatus according to this embodiment, the start / stop control of the electric oil pump in the reference example of the technique related to the vehicle control apparatus according to the present invention will be described.
In the vehicle control apparatus of this reference example, the start timing of the electric oil pump 12 is set when the vehicle speed V has decreased to a predetermined vehicle speed (hereinafter referred to as EOP start vehicle speed) VEOPON, and the stop timing of the electric oil pump 12 is set to a predetermined value after the engine is started. It is assumed that time (hereinafter referred to as EOP stop delay time) TEOPOFF has elapsed. However, the EOP start vehicle speed VEOPON that determines the start timing of the electric oil pump 12 and the EOP stop delay time TEOPOFF that determines the stop timing of the electric oil pump 12 are changed according to the operating oil temperature of the transmission 6. Thus, a stable hydraulic pressure is supplied to the transmission 6.

The start control and stop control of the electric oil pump 12 in the reference example will be described according to the flowcharts of FIGS. 3 and 4 and the time chart of FIG. In FIG. 5, “EOP drive pressure” indicates the discharge pressure of the electric oil pump 12, and “MOP drive pressure” indicates the discharge pressure of the mechanical oil pump 11.
First, startup control of the electric oil pump 12 in the reference example will be described according to the flowchart of FIG. 3 and the time chart of FIG.
First, in step S101, it is determined whether or not the engine 2 can be stopped. In this case, it is determined that the engine 2 can be stopped when the stop condition of the engine 2 excluding the vehicle speed V, that is, the brake switch is “ON” and the accelerator pedal depression amount is “0”. .

If the determination result in step S101 is “NO” (engine cannot be stopped), the process proceeds to step S102, and the hydraulic oil of the transmission 6 detected by the oil temperature sensor 38 with reference to the EOP start vehicle speed map shown in FIG. The EOP start vehicle speed VEOPON corresponding to the temperature is searched, and the execution of this routine is once ended.
The EOP start vehicle speed map is obtained by presetting the EOP start vehicle speed VEOPON in accordance with the hydraulic oil temperature. When the hydraulic oil temperature is low, the EOP start vehicle speed VEOPON is set low and the hydraulic oil temperature increases. The EOP start vehicle speed VEOPON is set to be high. However, the lower limit value of the EOP start vehicle speed VEOPON does not fall below the engine stop permission vehicle speed VENGST. Here, when the EOP start vehicle speed VEOPON is increased, the start timing of the electric oil pump 12 is advanced, and when the EOP start vehicle speed VEOPON is decreased, the start timing of the electric oil pump 12 is delayed. That is, by changing the EOP start vehicle speed VEOPON, the start timing of the electric oil pump 12 can be changed earlier or later.

If the determination result in step S101 is “YES” (engine can be stopped), the process proceeds to step S103, where the vehicle speed V calculated based on the output signal of the output shaft speed sensor 19 is the EOP activation searched in step S102. It is determined whether or not the vehicle speed is VEOPON or less.
If the determination result in step S103 is “NO” (V> VEOPON), there is no need to start the electric oil pump 12, so the execution of this routine is temporarily terminated.
When the determination result in step S103 is “YES” (V ≦ VEOPON), the process proceeds to step S104, the electric oil pump 12 is activated, and the execution of this routine is once ended.
By controlling the EOP start vehicle speed VEOPON in this way, the start timing of the electric oil pump 12 when the engine is stopped can be made earlier as the hydraulic oil temperature of the transmission 6 is higher.

  By the way, as shown in the time chart of FIG. 5, when the engine 2 is stopped, the discharge pressure of the mechanical oil pump 11 decreases with a decrease in the engine speed, but when the hydraulic oil temperature of the transmission 6 is high in the first place. Since the viscosity of the hydraulic oil is reduced, the discharge pressure of the mechanical oil pump 11 before the engine is stopped is lower than when the hydraulic oil temperature is low. In such a case, if the electric oil pump 12 is started at the same timing as when the hydraulic oil temperature of the transmission 6 is low, the discharge pressure of the mechanical oil pump 11 is decreased due to the decrease in the engine speed. The discharge pressure does not rise in time, and the hydraulic pressure of the transmission 6 cannot be secured above a predetermined value.

However, in the control device of this reference example, as described above, the EOP start vehicle speed VEOPON is changed according to the hydraulic oil temperature of the transmission 6, so that the electric oil pump 12 becomes higher as the hydraulic oil temperature of the transmission 6 becomes higher. Since the start timing can be made earlier, the decrease in the discharge pressure of the mechanical oil pump 11 can be compensated by the discharge pressure of the electric oil pump 12, and as a result, while ensuring the operating oil pressure of the transmission 6 above a predetermined value, Switching from the mechanical oil pump 11 to the electric oil pump 12 can be performed smoothly.
As a result, a stable hydraulic pressure can be supplied to the transmission 6 even when the engine 2 is stopped, regardless of the hydraulic oil temperature, so that the clutch engagement state in the transmission 6 can be kept stable.

Next, stop control of the electric oil pump 12 in the reference example will be described according to the flowchart of FIG. 4 and the time chart of FIG.
First, in step S201, it is determined whether or not a restart condition for the engine 2 is satisfied. In this case, it is determined that the restart condition of the engine 2 is satisfied when the brake switch is “OFF” and the amount of depression of the accelerator pedal satisfies all predetermined values or more.

If the determination result in step S201 is “NO” (engine restart condition is not established), the process proceeds to step S202, and the transmission 6 detected by the oil temperature sensor 38 with reference to the EOP stop delay time map shown in FIG. The EOP stop delay time TEOPOFF corresponding to the hydraulic oil temperature is searched, and the searched EOP stop delay time TEOPOFF is set as an initial value in the EOP stop delay timer. Thereafter, the process proceeds from step S202 to step S203, the drive of the electric oil pump 12 is continued, and the execution of this routine is once ended.
The EOP stop delay time map is obtained by presetting the EOP stop delay time TEOPOFF according to the hydraulic oil temperature. When the hydraulic oil temperature is low, the EOP stop delay time TEOPOFF is set short and the hydraulic oil temperature is high. Accordingly, the EOP stop delay time TEOPOFF is set to be longer. Here, the EOP stop delay timer is a timer that starts counting down at the same time when the engine restart condition is satisfied and the engine 2 is restarted. If the EOP stop delay time TEOPOFF is shortened, the stop timing of the electric oil pump 12 becomes earlier, and EOP If the stop delay time TEOPOFF is lengthened, the stop timing of the electric oil pump 12 is delayed. That is, by changing the EOP stop delay time TEOPOFF, the stop timing of the electric oil pump 12 can be changed earlier or later.

If the determination result in step S201 is “YES” (engine restart condition erect), the countdown of the EOP stop delay timer is started, and the process proceeds to step S204, where the count value TEOP of the EOP stop delay timer is “0”. It is determined whether or not.
When the determination result in step S204 is “NO” (TEOP> 0), the process proceeds to step S203, the drive of the electric oil pump 12 is continued, and the execution of this routine is temporarily ended.

If the determination result in step S204 is “YES” (TEOP ≦ 0), the process proceeds to step S205, the electric oil pump 12 is stopped, and the execution of this routine is temporarily ended. That is, when the engine restart condition is satisfied, the drive of the electric oil pump 12 is continued until the count value TEOP of the EOP stop delay timer becomes “0”, and when the count value TEOP reaches “0”, the electric oil pump 12 is stopped.
By controlling the EOP stop delay time TEOPOFF in this way, the stop timing of the electric oil pump 12 at the time of engine restart can be delayed as the hydraulic oil temperature of the transmission 6 is higher.

  Incidentally, as shown in the time chart of FIG. 5, when the hydraulic oil temperature of the transmission 6 is high, the viscosity of the hydraulic oil is lowered, so that the increase in the discharge pressure of the mechanical oil pump 11 after the engine restarts is activated. It is slower than when the oil temperature is low. In such a case, if the electric oil pump 12 is stopped at the same timing as when the hydraulic oil temperature of the transmission 6 is low, the driving pressure of the electric oil pump 12 decreases before the discharge pressure of the mechanical oil pump 11 sufficiently increases. As a result, the hydraulic pressure of the transmission 6 cannot be secured above a predetermined value.

However, in the control apparatus of this reference example, as described above, the EOP stop delay time TEOPOFF is changed according to the hydraulic oil temperature of the transmission 6, so that the electric oil pump 12 becomes higher as the hydraulic oil temperature of the transmission 6 becomes higher. Therefore, the delay in the increase in the discharge pressure of the mechanical oil pump 11 due to the decrease in the viscosity of the hydraulic oil can be compensated by the discharge pressure of the electric oil pump 12. As a result, the transmission 6 Switching from the electric oil pump 12 to the mechanical oil pump 11 can be performed smoothly while ensuring the hydraulic pressure at a predetermined value or higher.
As a result, a stable hydraulic pressure can be supplied to the transmission 6 even when the engine 2 is restarted regardless of the hydraulic oil temperature, so that the clutch engagement state in the transmission 6 can be kept stable.

  In this way, by changing the start timing or stop timing of the electric oil pump 12 according to the hydraulic oil temperature of the transmission 6, the drive period of the electric oil pump 12 is changed, so that the engine 2 is stopped or restarted. At the time of start-up, stable hydraulic pressure can be supplied to the transmission 6, and the engagement state of the clutch in the transmission 6 can be kept stable.

  If the oil temperature sensor 38 is out of order, the EOP start vehicle speed VEOPON and the EOP stop delay time TEOPOFF when the oil temperature is higher than the preset standard oil temperature and the predetermined oil temperature is used for electric operation. Start control and stop control of the oil pump 12 are executed. In this way, even when the hydraulic oil temperature of the transmission 6 is unknown due to the failure of the oil temperature sensor 38, the electric oil pump 12 is activated so that a stable hydraulic pressure can be supplied to the transmission 6. Can be stopped.

  Next, the control of the electric oil pump 12 in the embodiment of the vehicle control apparatus according to the present invention will be described with reference to the drawings of FIGS.

  In the reference example, by changing the start timing or stop timing of the electric oil pump 12 according to the hydraulic oil temperature of the transmission 6, a stable hydraulic pressure can be applied to the transmission 6 even when the engine 2 is stopped or restarted. In this embodiment, the start timing and stop timing of the electric oil pump 12 are constant regardless of the hydraulic oil temperature of the transmission 6, and the drive pressure of the electric oil pump 12 is set according to the hydraulic oil temperature. By making the change, a stable hydraulic pressure can be supplied to the transmission 6 even when the engine 2 is stopped or restarted.

Hereinafter, the drive pressure determination process of the electric oil pump 12 will be described with reference to the flowchart of FIG. 8 and the time chart of FIG. In FIG. 9, “EOP drive pressure” indicates the discharge pressure of the electric oil pump 12, and “MOP drive pressure” indicates the discharge pressure of the mechanical oil pump 11.
First, in step S301, it is determined whether or not the engine 2 can be stopped. In this case, it is determined that the engine 2 can be stopped when the stop condition of the engine 2 excluding the vehicle speed V, that is, the brake switch is “ON” and the accelerator pedal depression amount is “0”. .

When the determination result in step S301 is “NO” (engine stop is impossible), the process proceeds to step S302, and the hydraulic oil of the transmission 6 detected by the oil temperature sensor 38 with reference to the EOP drive pressure map shown in FIG. A drive pressure (hereinafter referred to as an EOP drive pressure) PEOP of the electric oil pump 12 corresponding to the temperature is searched, and the execution of this routine is temporarily terminated.
The EOP drive pressure map is obtained by presetting the EOP drive pressure PEOP according to the hydraulic oil temperature. When the hydraulic oil temperature is low, the EOP drive pressure PEOP is set low, and as the hydraulic oil temperature increases. The EOP driving pressure PEOP is set to be high.

When the determination result in step S301 is “YES” (engine can be stopped), the process proceeds to step S303, the drive pressure of the electric oil pump 12 is set to the drive pressure searched in step S302, and the electric oil pump 12 is turned on. Start up and end the execution of this routine.
By controlling the EOP drive pressure PEOP in this way, the drive pressure of the electric oil pump 12 can be increased as the hydraulic oil temperature of the transmission 6 is higher.

  By the way, as shown in the time chart of FIG. 9, when the engine 2 is stopped, the discharge pressure of the mechanical oil pump 11 decreases with a decrease in the engine speed, but in the first place when the hydraulic oil temperature of the transmission 6 is high. Since the viscosity of the hydraulic oil is reduced, the discharge pressure of the mechanical oil pump 11 before the engine is stopped is lower than when the hydraulic oil temperature is low. In such a case, if the electric oil pump 12 is started by setting the same drive pressure as when the hydraulic oil temperature of the transmission 6 is low, the discharge pressure of the electric oil pump 12 increases due to a decrease in the discharge pressure of the mechanical oil pump 11. As a result, the operating hydraulic pressure of the transmission 6 cannot be secured above a predetermined value.

However, in the control device of this embodiment, as described above, the EOP drive pressure PEOP is changed according to the hydraulic oil temperature of the transmission 6, so that the electric oil pump 12 becomes higher as the hydraulic oil temperature of the transmission 6 becomes higher. Since the drive pressure is increased, the discharge pressure increase of the electric oil pump 12 can be accelerated, and the discharge pressure decrease of the mechanical oil pump 11 accompanying the decrease in the rotational speed of the engine 2 is compensated by the discharge pressure of the electric oil pump 12. As a result, the switching from the mechanical oil pump 11 to the electric oil pump 12 can be performed smoothly while ensuring the hydraulic pressure of the transmission 6 at a predetermined value or more.
As a result, a stable hydraulic pressure can be supplied to the transmission 6 even when the engine 2 is stopped, regardless of the hydraulic oil temperature, so that the clutch engagement state in the transmission 6 can be kept stable.

  Further, when considering the subsequent engine restart, as shown in the time chart of FIG. 9, when the hydraulic oil temperature of the transmission 6 is high, the viscosity of the hydraulic oil is lowered. The increase in the discharge pressure of the mechanical oil pump 11 becomes slower than when the hydraulic oil temperature is low. In such a case, if the electric oil pump 12 is driven by setting the same driving pressure as that when the hydraulic oil temperature of the transmission 6 is low, the electric oil pump 12 is driven before the discharge pressure of the mechanical oil pump 11 is sufficiently increased. As a result, the hydraulic pressure of the transmission 6 cannot be secured above a predetermined value.

However, in the control device of this embodiment, as described above, the EOP drive pressure PEOP is changed according to the hydraulic oil temperature of the transmission 6, so that the electric oil pump 12 becomes higher as the hydraulic oil temperature of the transmission 6 becomes higher. Since the drive pressure is increased, even if the electric oil pump 12 is stopped at the same timing as when the hydraulic oil temperature is low, the decrease in the drive pressure of the electric oil pump 12 can be delayed. The delay in the increase in discharge pressure of the mechanical oil pump 11 due to the decrease in viscosity can be compensated for by the discharge pressure of the electric oil pump 12. As a result, it is possible to smoothly switch from the electric oil pump 12 to the mechanical oil pump 11 while ensuring the hydraulic pressure of the transmission 6 at a predetermined value or more.
As a result, a stable hydraulic pressure can be supplied to the transmission 6 even when the engine 2 is stopped and restarted regardless of the hydraulic oil temperature, so that the clutch engagement state in the transmission 6 can be kept stable. .

In this way, by changing the driving pressure of the electric oil pump 12 according to the hydraulic oil temperature of the transmission 6, stable hydraulic pressure can be supplied to the transmission 6 when the engine 2 is stopped or restarted. The clutch 6 in the transmission 6 can be kept in a stable state.
When the oil temperature sensor 38 is malfunctioning, the EOP driving pressure PEOP at a predetermined oil temperature higher than the preset standard oil temperature is adopted to drive the electric oil pump 12. Execute control. In this way, even when the hydraulic oil temperature of the transmission 6 is unknown due to the failure of the oil temperature sensor 38, the electric oil pump 12 is driven so that a stable hydraulic pressure can be supplied to the transmission 6. The pressure can be set.

[Other Examples]
The present invention is not limited to the embodiment described above.
For example, it is possible to combine the reference example and the example described above. That is, the start timing or stop timing of the electric oil pump 12 may be changed according to the hydraulic oil temperature of the transmission 6, and the drive pressure of the electric oil pump 12 may be changed according to the hydraulic oil temperature. In this way, more stable hydraulic pressure can be supplied to the transmission 6 when the engine 2 is stopped or restarted, and the clutch engagement state in the transmission 6 can be kept more stable.

  In the above-described embodiments, the present invention has been described with reference to an example in which the present invention is applied to a hybrid vehicle that uses an engine and an electric motor as driving force generation means. It is.

1 Hybrid vehicle (vehicle)
2 Engine (driving force generating means)
3 Motor generator (driving force generating means)
6 Transmission 11 Mechanical oil pump 12 Electric oil pump 38 Oil temperature sensor (oil temperature detection means)
W drive wheel

Claims (3)

Driving force generating means including at least an engine;
A transmission that shifts and transmits the driving force generated by the driving force generating means to the drive wheels;
A mechanical oil pump driven by the driving force generating means to supply hydraulic pressure to the transmission;
An electric oil pump that is started when the engine is stopped, supplies hydraulic pressure to the transmission, and stops when the engine is started;
Oil temperature detection means for detecting the oil temperature of the hydraulic oil supplied to the transmission;
A vehicle control device for automatically stopping and starting the engine under a predetermined condition,
The higher the oil temperature detected by the oil temperature detection means, the higher the drive pressure of the electric oil pump,
When the oil temperature detecting means is out of order, control on a higher temperature side than the standard oil temperature is executed.   The vehicle according to claim 1, wherein when a predetermined condition for restarting the engine is satisfied, the stop timing of the electric oil pump is delayed as the oil temperature detected by the oil temperature detecting means is higher. Control device.   3. The start timing of the electric oil pump is advanced as the oil temperature detected by the oil temperature detecting means is higher when a predetermined condition for automatically stopping the engine is satisfied. The vehicle control device described in 1.