JP2010077826A - Idle stop control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent engagement shock of a clutch when transferring from an idle stop to running in an idle stop vehicle equipped with a transmission mechanism that controls hydraulic pressure of a mechanical oil pump by a normally open clutch controlling solenoid for acting on the clutch and an idle stop function. <P>SOLUTION: The state of an on-board battery 7 is detected during running of the vehicle by an idle stop prohibition ECU 9. Based on the detected result immediately before an idle stop, the period of time in which the battery voltage becomes lower than a prescribed voltage at which control of the clutch controlling solenoid 6 is possible due to restarting of the engine at completion of the idle stop is estimated. When the estimated period of time is longer than a set reference time, and an idle stop is performed, when there is a risk that engagement shock of the clutch might occur when transferring from an idle stop to running, the idle stop is prohibited. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a speed change mechanism that acts on a clutch by controlling the hydraulic pressure of a mechanical oil pump driven by engine rotation by a normally open clutch control solenoid, and an idle stop function that stops engine rotation while traveling is stopped. In particular, the present invention relates to prevention of clutch engagement shock when shifting from idle stop to running.

Conventionally, in a vehicle equipped with a continuously variable transmission mechanism (CVT mechanism), an automatic transmission control mechanism (A / T mechanism), and an idle stop function (idle stop vehicle), the engine is restarted upon completion of idle stop. In order to alleviate the shock of clutch engagement when shifting to running, the transmission mechanism is equipped with an electric oil pump, check valve and accumulator to maintain the hydraulic pressure acting on the clutch even during idle stop. (For example, refer to Patent Document 1).
JP-A-8-14076 (for example, abstract, paragraphs [0026]-[0028],-[0017], FIG. 3, etc.)

  In an idle stop vehicle having the continuously variable transmission mechanism, automatic transmission control mechanism, and idle stop function, the conventional electric oil pump, check valve, and accumulator are omitted, and the machine operates by rotating the engine instead. In order to reduce costs by providing a hydraulic oil pump, and from the viewpoint of fail-safe, the hydraulic pressure of the mechanical oil pump is controlled by a normally open clutch control solenoid so as to act on the clutch. In this case, depending on the exhausted state of the vehicle-mounted battery, it is expected that the battery voltage will drop below a predetermined voltage that can be controlled by the clutch control solenoid, based on the engine restart by the starter immediately after the idling stop.

  When the battery voltage falls below a predetermined voltage (for example, 9V) at which the clutch control solenoid can be controlled, the clutch control solenoid is used until the battery voltage of the in-vehicle battery recovers to the predetermined voltage or higher by restarting the engine. Is opened, and the oil pressure of the oil pump passes through the clutch control solenoid and acts on the clutch.

  For this reason, especially when the idle stop time is short (approximately less than 3 seconds) and the oil pump hydraulic pressure does not drop sufficiently while the engine is stopped, the large oil pump hydraulic pressure acts on the clutch when the engine is restarted. There is a problem that a combined shock occurs and the passenger feels uncomfortable.

  The present invention relates to a shift mechanism for controlling a hydraulic pressure of a mechanical oil pump by a normally open clutch control solenoid and acting on the clutch, and an idle stop vehicle having an idle stop function. It is an object of the present invention to prevent clutch engagement shocks when doing so.

  In order to achieve the above-described object, an idle stop control device of the present invention is a speed change mechanism that acts on a clutch by controlling the hydraulic pressure of a mechanical oil pump driven by engine rotation by a normally open clutch control solenoid. And an idle stop control device for a vehicle having an idle stop function for stopping the engine rotation while the vehicle is stopped, a detecting means for detecting a depleted state of the in-vehicle battery while the vehicle is traveling, and the detection just before the idle stop Based on the detection result of the means, a prediction means for predicting a time when the battery voltage falls below a predetermined voltage capable of controlling the solenoid for clutch control due to engine restart at the end of idle stop, and a prediction time of the prediction means is set And prohibiting means to prohibit idle stop when it is longer than the specified reference time It is characterized in that the (claim 1).

  The idle stop control device according to the first aspect of the present invention detects the state of the in-vehicle battery while the vehicle is running by the detecting means, and based on the detection result of the detecting means immediately before the idle stop, the predicting means restarts the engine at the end of the idle stop. The time for the battery voltage to drop below a predetermined voltage at which the clutch control solenoid can be controlled by starting is predicted. When the prediction time of the prediction means is longer than the set reference time and the idle stop is performed, there is a possibility that a clutch engagement shock may occur when shifting from idle stop to running. Is prohibited.

  Therefore, in an idle vehicle equipped with a transmission mechanism that controls the hydraulic pressure of a mechanical oil pump by a normally open clutch control solenoid and that acts on the clutch, and an idle stop function that stops engine rotation while the vehicle is stopped, Considering the consumption state of the on-vehicle battery, when the idle stop time is short and it is expected that clutch engagement shock will occur when shifting from idle stop to running, idle stop is prohibited and the clutch engagement shock is ensured Can be prevented.

  Next, an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a block diagram of the idle stop control device of the present embodiment, FIG. 2 is a flowchart for explaining the operation, and FIG. 3 is a timing chart for explaining the operation.

  In FIG. 1, 1 is an engine including a starter of an idle stop vehicle, 2 is a mechanical oil pump that is rotationally driven by the engine 1, and 3 is a speed change mechanism (for example, continuously variable) from the oil pump 2 to a clutch (starting clutch) 4. 5 is a pressure regulating valve provided on the oil pump 2 side of the hydraulic passage 3, and 6 is a normally open clutch provided between the pressure regulating valve 5 of the hydraulic passage 3 and the clutch 4. Control solenoid.

  Moreover, in FIG. 1, 7 is a vehicle-mounted battery and consists of a 12V lead battery. Reference numeral 8 denotes a sensor unit having current / voltage and liquid temperature sensors of the on-vehicle battery, and 9 denotes an idle stop prohibition ECU that takes in the sensor output of the sensor unit 8 every moment, and the idle stop prohibition of steps S1 to S6 in FIG. It consists of a microcomputer that executes control, and forms detection means, prediction means, and prohibition means of the present invention. Reference numeral 10 denotes a data memory that holds data of the predicted time according to the present invention obtained by experiments and the like, and is referred to by the idle stop prohibition ECU 9. Reference numeral 11 denotes a microcomputer-configured idle stop control ECU (eco-run control ECU) that executes idle stop control and restarts the engine 1 when the prohibition means of the idle stop prohibition ECU 9 does not prohibit idle stop. Control etc.

  The detection means of the idle stop prohibiting ECU 9 monitors the current / voltage / temperature of the in-vehicle battery 7 based on the current / voltage / liquid temperature detection output of the sensor unit 8 and calculates the power balance of the in-vehicle battery 7 every moment. Then, the consumption state (residual power) of the in-vehicle battery 7 is detected while the vehicle is traveling. Further, the predicting means of the idle stop prohibiting ECU 9 determines that the predicted voltage corresponding to the exhausted state detected by the detecting means, that is, when the engine 1 is started by operating the starter in the exhausted state, the battery voltage is changed to the clutch control solenoid. 6 is read from the data memory 10 when the battery voltage drops below the predetermined voltage (9V) that can be controlled, in other words, the time until the battery voltage recovers to the predetermined voltage, and based on the detection result of the detection means immediately before the idle stop. Then, a time for the battery voltage to fall below the predetermined voltage due to the restart of the engine 1 at the end of the idle stop is predicted. Further, the prohibiting means of the idle stop prohibiting ECU 9 outputs an idle stop prohibiting command to the idle stop control ECU 11 when the predicting time of the predicting means is longer than a set reference time (for example, 3 seconds) and prohibits the idling stop. To do.

  The data memory 10 is a non-volatile memory such as an EEPROM or a flash memory. When the vehicle-mounted battery 7 is in various exhausted states, data on the time when the battery voltage drops below the predetermined voltage by restarting the engine 1 is previously mapped. It is written and held in data form.

  Based on the above configuration, when the driver sets the eco-run mode and operates, the detection means of the idle stop prohibiting ECU 9 is sometimes used for the vehicle-mounted battery 7 based on the current / voltage and liquid temperature detection outputs of the sensor unit 8. The momentary consumption state is detected (step S1 in FIG. 2). Further, the predicting means of the idle stop prohibiting ECU 9 refers to the data memory 10 and obtains a predicted time corresponding to the momentary consumption state of the in-vehicle battery 7 (step S2 in FIG. 2).

  If the predicted time is longer than the reference time and the idling stop is not prohibited by the prohibiting means, the idling stop prohibiting ECU 9 determines the idling stop start information obtained from the idling stop control ECU 11 (the brake, accelerator, etc. 2), the process proceeds from step S3 in FIG. 2 to step S6 via steps S4 and S5, and the idle state is determined. An idle stop prohibition command is output to the stop control ECU 11, and the idle stop control by the idle stop control ECU 11 is prohibited.

  Next, changes in the voltage of the in-vehicle battery 7 (battery voltage), the engine speed, and the hydraulic pressure acting on the clutch 4 due to idle stop will be described with reference to FIG.

  First, it is assumed that time t1 in FIG. 3 is an idle stop start time and time t2 is an idle stop end time. In this case, the battery voltage shown in FIG. 6A is lowered to a voltage lower than the reference voltage (9V) by engine restart at time t2, but the consumption state of the in-vehicle battery 7 is light and the battery voltage of the in-vehicle battery 7 is the same. When it is predicted to return to the reference voltage at time T1 from time t2 to time t31 (<reference time) as indicated by the solid line αa in FIG. 1A, the idle stop is started at time t1.

  At this time, due to the end of the idle stop at time t2, the rotational speed of the engine 1 increases as shown in FIG. 3B, but the battery voltage becomes the reference voltage before the engine 1 reaches a complete explosion (for example, 600 rpm). After that, since the clutch control solenoid 6 is controlled by the idle stop control ECU 11, the hydraulic pressure acting on the clutch 4 has a short idle stop time, and the hydraulic pressure of the oil pump 2 is sufficiently high while the engine 1 is stopped. Even if it is not lowered, it gradually rises to the normal hydraulic pressure Pc as shown by the solid line αb in FIG.

  On the other hand, if the in-vehicle battery 7 is heavy and the idle stop at time t1 to t2 is executed, the battery voltage of the on-vehicle battery 7 is changed to the time t2 after the end of the idle stop as shown by the one-dot broken line βa in FIG. When returning to the reference voltage at time T2 (> reference time) at time t32, the engine speed increases as shown in FIG. 5B, and the battery voltage rises to the reference voltage after reaching the complete explosion. During this period (almost time T2), the clutch control solenoid 6 is not controlled, and the oil pressure of the oil pump 2 passes through the clutch control solenoid 6, as shown by a dashed line βb in FIG. As the engine rotates, the hydraulic pressure acting on the clutch 4 increases sharply. Therefore, when the idle stop time is short and the oil pressure of the oil pump 2 is not sufficiently lowered while the engine is stopped, the engagement shock of the clutch 4 occurs. When the battery voltage increases to the reference voltage, the clutch control solenoid 6 is thereafter controlled by the idle stop control ECU 11, and the hydraulic pressure acting on the clutch 4 increases to the normal hydraulic pressure Pc along the solid line αb in FIG. To do.

  However, in the case of the present embodiment, the in-vehicle battery 7 is heavily consumed and, as described above, after returning to the reference voltage at time T2 (> reference time) from time t2 to time t32 after the end of idle stop, Since an idle stop prohibition command is output from the stop prohibition ECU 9 to the idle stop control ECU 11 and the idle stop control by the idle stop control ECU 11 is prohibited, the engagement shock of the clutch 4 does not occur.

  For this reason, in an idle vehicle having a transmission mechanism for controlling the hydraulic pressure of the mechanical oil pump 2 by the normally open clutch control solenoid 6 and acting on the clutch 4, and an idle stop function, the engagement shock of the clutch 4 This is particularly suitable for idle stop control when the in-vehicle battery 7 is small, light and inexpensive with a small capacity.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. 7 may be set appropriately according to the capacity of the engine 7, the output of the engine 1, and the like. Further, the configuration of the transmission mechanism and the like may be different from those of the above-described embodiment. Furthermore, the in-vehicle battery 7 may be a secondary battery other than the lead storage battery.

  The present invention is applied to idle stop control of various vehicles provided with a transmission mechanism for controlling the hydraulic pressure of a mechanical oil pump by a normally open clutch control solenoid and acting on the clutch, and an idle stop function. can do.

It is a block diagram of the idle stop control device of one embodiment of the present invention. It is a flowchart for operation | movement description of FIG. 2 is a timing chart for explaining the operation of FIG. 1.

Explanation of symbols

1 Engine 2 Oil pump 4 Clutch 6 Solenoid for clutch control 7 On-board battery 9 Idle stop prohibition ECU

Claims (1)

A transmission mechanism that acts on the clutch by controlling the hydraulic pressure of a mechanical oil pump driven by the engine rotation by a normally open clutch control solenoid, and an idle stop function that stops the engine rotation while the vehicle is stopped. An idle stop control device for a vehicle,
Detecting means for detecting a consumption state of the on-vehicle battery while the vehicle is running;
Prediction means for predicting the time when the battery voltage drops below a predetermined voltage capable of controlling the solenoid for clutch control based on the detection result of the detection means immediately before idle stop, due to engine restart at the end of idle stop;
An idle stop control device comprising: prohibiting means for prohibiting idle stop when the prediction time of the prediction means is longer than a set reference time.

Images