JP2009221980A - Idle stop control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch oil pumps without making a driver feel a switching noise, and to generate the proper oil pump pressure by restricting consumption of a battery to the minimum in an idle stop, in regard to a vehicle comprising an idle-stop function having a mechanical oil pump and an electric oil pump. <P>SOLUTION: An electric oil pump control section 20 starts power supply to an electric pump motor 6M of an electric pump 6 by electrifying a relay coil 10C of a pump relay 10 so as to turn on a relay contact point 10S before an engine 1 stops after the idle-stop condition is satisfied. At that time, till the engine 1 stops, an instruction value of the number of revolution of the electric pump motor is set at 0, and the pressure to be generated by the electric oil pump is set at 0, and after the engine 1 stops, the instruction value of the number of revolution of the electric pump motor is set at a preset instruction value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes both a mechanical oil pump driven by an engine and an electric oil pump driven by an electric motor, and is adapted to switch from a mechanical oil pump to an electric oil pump when idling stop. About.

  In recent years, when a vehicle stops while traveling and a predetermined stop condition is satisfied, the engine is automatically stopped to save fuel, reduce exhaust emissions, reduce noise, etc. A vehicle having an idle stop function has been put into practical use.

  In such a vehicle, when the engine stops, the mechanical oil pump driven by the engine stops. For example, the oil supplied to the forward clutch of the automatic transmission also escapes from the oil passage. The oil pressure will drop.

  Therefore, when the engine is restarted, the forward clutch that should be engaged during forward travel is also in a state in which the engaged state is released, and the forward clutch is not quickly engaged when the engine is restarted. In other words, the accelerator pedal is depressed in a neutral state, and there is a possibility that the forward clutch is engaged and an engagement shock occurs when the engine is blown up.

Therefore, for example, Japanese Patent Application Laid-Open No. 2001-12594 includes both a mechanical oil pump driven by an engine and an electric oil pump driven by an electric motor, and when the mechanical oil pump is stopped when the engine is stopped during idle stop, A technique for ensuring the supply of working fluid to an automatic transmission by operating an electric oil pump alone to compensate for a shortage of flow rate is disclosed.
JP 2001-12594 A

  However, in the technique disclosed in Patent Document 1 described above, power supply ON and power OFF of an electric motor (electric pump motor) that drives an electric oil pump is realized using a relay switch. When is used, there is a problem that the driver can hear the switching sound generated at the time of switching. In particular, in an idle stop vehicle, the switching of the electric pump motor switching relay is performed after the engine is stopped, which may cause a louder sound and give the driver a sense of discomfort.

  The present invention has been made in view of the above circumstances, in a vehicle having an idle stop function having a mechanical oil pump and an electric oil pump, without causing the driver to be aware of the switching sound of both oil pumps, Another object of the present invention is to provide a vehicle idle stop control device capable of generating an appropriate oil pump pressure while minimizing battery consumption during idle stop.

  The present invention includes an idle stop control means for stopping an engine when a preset idle stop condition is satisfied, a mechanical oil pump driven by the engine, an electric oil pump driven by an electric motor, and the idle stop. Electric oil pump control means for starting power supply to the electric motor after the condition is established and before stopping the engine by the idle stop control means, and starting the operation of the electric oil pump after the engine is stopped. It is said.

  The vehicle idle stop control device according to the present invention is a vehicle having an idle stop function having a mechanical oil pump and an electric oil pump, without causing the driver to be aware of the switching sound of both oil pumps, It is possible to generate an appropriate oil pump pressure while minimizing battery consumption during idle stop.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of the present invention, FIG. 1 is a block diagram schematically showing the entire idle stop control device, and FIG. 2 is a flowchart of electric oil pump control.

  In FIG. 1, reference numeral 1 denotes an engine, and driving force from the engine 1 is input to the automatic transmission 3 via the torque converter 2 and output to the output shaft 4 of the vehicle.

  Further, the vehicle is provided with a mechanical oil pump 5 such as a gear pump driven by the engine 1, and an electric pump motor 6M is driven by an oil pump 6P with respect to the mechanical oil pump 5. A type oil pump 6 is also provided.

  The hydraulic pressure from the mechanical oil pump 5 is supplied to a hydraulic control circuit (not shown) through a hydraulic circuit 7, and the hydraulic pressure from the electric oil pump 6 passes through a check valve 8 and is not shown through the hydraulic circuit 7. To be supplied.

  The electric pump motor 6M of the electric oil pump 6 is constituted by, for example, a brushless motor, and the electric power from the battery 9 is opened and closed by a relay contact 10S that is opened and closed by a relay coil 10C of a switching relay (pump relay) 10. Power is supplied.

  Moreover, the electric pump motor 6M of the electric oil pump 6 is configured such that the hydraulic pressure generated by the oil pump 6P can be adjusted by controlling the rotation speed of the electric pump motor through the drive circuit 11.

  A signal for the relay coil 10C of the pump relay 10 that controls power supply of the electric pump motor 6M and a control signal for the drive circuit 11 are output from the electric oil pump control unit 20 described later.

  The vehicle is provided with an idle stop control unit 21 that realizes an idle stop function. In the idle stop control unit 21, for example, a brake switch (not shown) is operated, and the vehicle speed is equal to or less than a threshold value (substantially omitted). When the engine water temperature is equal to or higher than the threshold value, it is determined that the idle stop condition is satisfied, and the engine control unit 22 is set with an idle stop condition determination flag FISS to stop the engine (FISS = 1). And output. In addition, when the above-mentioned idle stop condition is not established while the vehicle is idling, the engine control unit 22 clears the idle stop condition determination flag FISS (FISS = 0) to restart the engine 1. Output. The idle stop condition determination flag FISS is also output to the electric oil pump control unit 20. That is, the idle stop control unit 21 is provided as idle stop control means.

  The electric oil pump control unit 20 receives an idle stop condition determination flag FISS from the idle stop control unit 21 and receives an engine speed Ne from the engine control unit 22. In accordance with the electric oil pump control program to be described later, after the idle stop condition is established, before the engine 1 is stopped, the relay coil 10C of the pump relay 10 is energized to turn on the relay contact 10S, and the electric oil pump 6 Power supply to the electric pump motor 6M is started. At this time, until the engine 1 is stopped, the rotation speed instruction value of the electric pump motor is set to 0, and the pressure by the electric oil pump 6 is set to 0. After the engine 1 is stopped, the rotation speed instruction of the electric pump motor is set. The value is set to a preset instruction value (for example, a pressure value of 70% or less of the maximum rotation speed). In the engine control unit 22, when the signal of FISS = 1 is input from the idle stop control unit 21 and the engine stop signal (fuel supply cutoff command) is input from the electric oil pump control unit 20, the engine control unit 22 1 is stopped. When the idle stop condition is not satisfied and FISS = 0 is input to restart the engine 1, the energization of the relay coil 10C of the pump relay 10 is cut off and the relay contact 10S is turned off after the engine 1 is started. Then, power supply to the electric pump motor 6M of the electric oil pump 6 is stopped. The engine control unit 22 starts the engine 1 when a signal of FISS = 0 is input from the idle stop control unit 21 and an engine start signal is input from the electric oil pump control unit 20. Thus, the electric oil pump control unit 20 is provided as electric oil pump control means.

Next, the electric oil pump control program executed by the electric oil pump control unit 20 will be described with reference to the flowchart of FIG.
First, in step (hereinafter abbreviated as “S”) 101, an idle stop condition determination flag FISS is read from the idle stop control unit 21.

  Next, in S102, it is determined whether FISS = 1, that is, whether the idle stop condition is satisfied. If the idle stop condition is not satisfied (FISS = 0), the process returns to S101 and the idle stop condition is satisfied ( If FISS = 1), the process proceeds to S103.

  When FISS = 1 and the process proceeds to S103, the relay coil 10C of the pump relay 10 is energized and the relay contact 10S is turned on.

  Next, in S104, the timer T1 is started. The timer T1 is a timer that predicts a response delay of the pump relay 10 and measures a preset time, and for example, a time tc1 of about 0.1 to 0.2 sec is set.

  Then, the process proceeds to S105, where it is determined whether or not the timer T1 has reached the above-mentioned time tc1, and if the timer T1 has reached the time tc1, the process proceeds to S106 and the rotation speed instruction value of the electric pump motor is set to 0. Output, and the pressure by the electric oil pump 6 is set to zero.

  Next, in S107, a fuel supply cutoff command is output to the engine control unit 22 so as to stop the engine 1.

  Next, in S108, the timer T2 is started. This timer T2 is a timer that estimates the time required for the engine speed Ne to become 0 after the fuel supply is cut off, and measures a preset time. For example, a time tc2 of about 1.0 sec is set. ing.

  Then, the process proceeds to S109, where it is determined whether or not the timer T2 has reached the above-described time tc2, and if the timer T2 has reached the time tc2, the process proceeds to S110 and the rotation speed instruction value of the electric pump motor is set to Dc ( For example, the pressure value is 70% of the maximum rotation speed), and the pressure by the electric oil pump 6 is set to a preset pressure.

  Next, the process proceeds to S111, where the idle stop condition determination flag FISS is read again from the idle stop control unit 21, and the process proceeds to S112, where it is determined whether the idle stop condition is not satisfied (FISS = 0). As a result of the determination, if the idle stop condition is still satisfied (if FISS = 1), the processing from S111 is repeated, and if the idle stop condition is not satisfied (if FISS = 0), the process proceeds to S113. Then, an engine start command is output to the engine control unit 22.

  In step S114, the engine speed Ne is read. In step S115, the engine speed Ne is determined to be Nec (for example, 700 rpm: stable hydraulic control can be performed with the hydraulic pressure from the mechanical oil pump 5 driven by the engine 1. It is determined whether or not the number of rotations is greater than or equal to.

  If the result of this determination is that the engine speed Ne is greater than Nec, the process proceeds to S116, where the relay coil 10C of the pump relay 10 is cut off and the relay contact 10S is turned OFF, and the electric pump of the electric oil pump 6 is turned on. The power supply to the motor 6M is stopped and the program is exited. If the engine speed Ne is less than Nec, the processing from S114 is repeated.

  As described above, according to the first embodiment of the present invention, the idle stop control unit 21 energizes the relay coil 10C of the pump relay 10 to stop the relay contact 10S after the idle stop condition is established and before the engine 1 is stopped. Is turned on, and power supply to the electric pump motor 6M of the electric oil pump 6 is started. If the idle stop condition is not established and FISS = 0 is input to restart the engine 1, the energization of the relay coil 10C of the pump relay 10 is interrupted and the relay contact 10S is started after the engine 1 is started. Is turned off, and power supply to the electric pump motor 6M of the electric oil pump 6 is stopped. Therefore, the operation of the pump relay 10 necessary for switching from the mechanical oil pump 5 to the electric oil pump 6 and switching from the electric oil pump 6 to the mechanical oil pump 5 is all performed by the engine 1. Since it is performed while driving, it is possible to realize a quiet and comfortable vehicle space without causing the driver to be aware of the switching sound.

  Further, until the engine 1 is stopped, the rotation speed instruction value of the electric pump motor is set to 0, and the pressure or flow rate by the electric oil pump 6 is set to 0, so that unnecessary hydraulic pressure is not generated until the engine 1 is stopped. It is possible to minimize the consumption of the battery 9 by driving the electric oil pump 6.

  In addition, after the engine 1 is stopped, the rotation speed instruction value of the electric pump motor is set to a preset instruction value (for example, a pressure value of 70% or less of the maximum rotation speed). It is possible to achieve the minimum necessary hydraulic pressure while minimizing.

  Next, FIG. 3 is a flowchart of electric oil pump control according to the second embodiment of the present invention. In the second embodiment, the determination of the engine stop at the time of idling stop is made by the prediction by the timer, whereas the actual engine speed is detected and determined in the second embodiment. However, the other functions and effects are the same as those of the first embodiment, so that the same components are denoted by the same reference numerals and description thereof is omitted.

  That is, as shown in FIG. 3, after outputting a fuel supply cutoff command to stop the engine 1 to the engine control unit 22 in S107, the process proceeds to S201, and the engine speed Ne is read.

  Then, the process proceeds to S202, where it is determined whether the engine speed Ne is 0, that is, whether the engine 1 has stopped. If it is determined that the engine 1 has stopped with Ne = 0, the process proceeds to S110, where the electric pump motor The rotation speed instruction value is output as Dc (for example, a pressure value of 70% of the maximum rotation speed), and the pressure by the electric oil pump 6 is set to a preset pressure. If Ne ≠ 0, the processing from S201 is repeated. Note that the processing after S110 is the same as that in the first embodiment, and will be omitted.

  As described above, according to the second embodiment, in addition to the same effects as those of the first embodiment, it is possible to perform an accurate control because it is determined directly that the engine is stopped at the engine speed Ne.

The block diagram which shows typically the whole idle stop control apparatus by 1st Embodiment of this invention. Same as above, electric oil pump control flowchart Flowchart of electric oil pump control according to the second embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 5 Mechanical oil pump 6 Electric oil pump 6M Electric pump motor 6P Oil pump 9 Battery 10 Pump relay 10C Relay coil 10S Relay contact 11 Drive circuit 20 Electric oil pump control part (electric oil pump control means)
21 Idle stop control unit (idle stop control means)
22 Engine control unit

Claims (4)

Idle stop control means for stopping the engine when a preset idle stop condition is satisfied;
A mechanical oil pump driven by the engine;
An electric oil pump driven by an electric motor;
Electric oil pump control means for starting power supply to the electric motor after the idle stop condition is established and before the engine is stopped by the idle stop control means, and starting the operation of the electric oil pump after the engine is stopped;
An idle stop control device for a vehicle, comprising:   2. The vehicle idle stop control device according to claim 1, wherein the electric oil pump control means determines the stop of the engine by a timer.   2. The vehicle idle stop control device according to claim 1, wherein the electric oil pump control means determines whether the engine is stopped based on a detected value of the engine speed.   The vehicle according to any one of claims 1 to 3, wherein the electric oil pump control means stops power supply to the electric motor after the engine is started when the engine is restarted. Idle stop control device.

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