JP5330098B2 - Engine idle control device - Google Patents

Description

  The present invention relates to an idle operation control in which an engine connected to an automatic transmission that establishes a desired shift stage by engaging and disengaging a plurality of friction engagement elements by hydraulic pressure is subjected to idle stop control based on a predetermined condition. The present invention relates to an engine idling operation control apparatus having means.

  An engine capable of idling stop control is known from Patent Document 1 below, which prohibits idling stop control when the temperature of oil in an automatic transmission exceeds a predetermined value.

  Further, in an engine capable of idling stop control, a technique for prohibiting idling stop control when the temperature of oil in an automatic transmission is less than a predetermined value is known from Patent Document 2 below.

  Further, in an engine capable of idling stop control, a technique for prohibiting idling stop control when the temperature of oil in an automatic transmission is not between an upper limit value and a lower limit value is known from Patent Document 3 below.

JP 2000-175304 A JP 2002-47961 A JP 2000-104587 A

  By the way, in the above-mentioned conventional one, the temperature of oil for determining whether to allow or prohibit the idle stop control is measured using a temperature sensor. This utilizes the fact that viscosity, which is an important factor for oil lubrication performance, is correlated with temperature. However, if there is an error in the electrical characteristics of the temperature sensor, if the oil has been replaced with oil with a different temperature characteristic, or if the oil has deteriorated and its characteristics have changed, the oil temperature will accurately indicate the state of the oil. It was not always. In addition, there is a problem that the number of parts increases by the temperature sensor, which causes an increase in cost.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to accurately determine whether the idle stop control is permitted or prohibited by using an existing hydraulic sensor in an automatic transmission.

In order to achieve the above object, according to the first aspect of the present invention, a plurality of friction engagement elements are hydraulically engaged and disengaged to be connected to an automatic transmission that establishes a desired gear stage. In an engine idle operation control device having an idle operation control means for performing idle stop control of the engine based on a predetermined condition, a hydraulic pressure detection means for detecting the hydraulic pressure of the automatic transmission, and the engine as an idle operation control means when there is controlled to idle stop state, and counting means for counting the elapsed time until the hydraulic pressure detected by the oil pressure detecting means decreases from the first threshold to the second threshold value, the elapsed time measured by said time measuring means a measurement time determining means for determining whether or not the range of less than the first predetermined time or more second predetermined time First traveling condition determining means for determining that the vehicle speed is equal to or higher than a predetermined vehicle speed and the vehicle travel distance is equal to or greater than a predetermined distance; 2 running condition determination means, and the idle operation control means permits idle stop control when the elapsed time is determined to be in a range not less than a first predetermined time and less than a second predetermined time, and the elapsed When it is determined that the time is equal to or longer than the second predetermined time, the engine is started by prohibiting idle stop control, and after the start, the first traveling condition determining means determines that the vehicle speed is equal to or higher than the predetermined vehicle speed. When it is determined that the travel distance is equal to or greater than the predetermined distance, the idle stop control is permitted, and when it is determined that the elapsed time is less than the first predetermined time, When the engine is started while prohibiting idle stop control, and after the start, the second traveling condition determining means determines that the vehicle speed is less than a predetermined vehicle speed and that the idle operation state is not less than a third predetermined time. idling control device for an engine and permits an idle stop control Ru been proposed.

  The hydraulic switch Sa of the embodiment corresponds to the hydraulic pressure detecting means of the present invention.

According to the present invention , the hydraulic pressure of the automatic transmission is detected by the hydraulic pressure detection means, and the elapsed time until the hydraulic pressure drops from the first threshold value to the second threshold value is counted by the time measuring means when the engine is in the idle stop state. It is determined whether or not the elapsed time is in the range of the first predetermined time or more and less than the second predetermined time by the time measuring time determination means. The idle operation control means permits the idle stop control when it is determined that the elapsed time is in the range from the first predetermined time to the second predetermined time, that is, when the viscosity of the oil is appropriate (temperature is appropriate). Otherwise, the engine is started with the idle stop control prohibited, so the oil viscosity is high (temperature is low) and the drivability deteriorates, or the oil viscosity is low (temperature is high). In the case where the oil is deteriorated or the lubricating performance is deteriorated, the idle operation can be permitted to bring the oil temperature close to an appropriate temperature. Moreover, since the temperature of the oil can be measured using an existing hydraulic pressure detection means in the automatic transmission without using a temperature sensor, the viscosity can be accurately determined by directly determining the hydraulic pressure of the automatic transmission, Further, the number of parts can be reduced by the temperature sensor, thereby contributing to cost reduction.

The idle operation control means, so if the elapsed time is determined to be the second predetermined time to start the engine by prohibiting the idle stop control (the temperature of the oil when cold), the operation of the engine A suitable viscosity (appropriate temperature) can be obtained by stirring the oil. When the first traveling condition determining means determines that the vehicle speed is equal to or greater than the predetermined vehicle speed and the vehicle travel distance is equal to or greater than the predetermined distance after the engine is started, the oil is agitated to an appropriate viscosity (heated to an appropriate temperature). Since it is determined that the idle stop control is permitted, unnecessary prohibition of the idle stop control can be minimized.

Further, when the idle operation control means determines that the elapsed time is less than the first predetermined time (when the oil viscosity is low and the temperature is high), the idle stop control is prohibited and the engine is started. The oil can be cooled to an appropriate temperature (increased viscosity) by operation. When the second running condition determining means determines that the vehicle speed is less than the predetermined vehicle speed and the idle operation state is longer than the third predetermined time after the engine is started, the viscosity of the oil has increased (cooled to an appropriate temperature). Therefore, the idle stop control is permitted and unnecessary prohibition of the idle stop control can be minimized.

The block diagram which shows the whole structure of an idle driving | operation control apparatus. The block diagram of the control system of an idle driving | operation control apparatus. The flowchart explaining an effect | action. The time chart explaining an effect | action.

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

  As shown in FIG. 1, an automatic transmission TM is connected to an engine E capable of idle stop control via a torque converter TC. An oil pump 12 driven by the engine E and an electric oil pump 13 operable even when the engine E is stopped include a hydraulic control means 11 for supplying control and lubrication hydraulic pressure to the automatic transmission TM and the torque converter TC. Is connected.

  The electronic control unit U that controls the idle stop control of the engine E includes the hydraulic pressure of the transmission TM detected by the hydraulic switch Sa, the vehicle speed detected by the vehicle speed sensor Sb, and the operating state of the engine E (during operation or during idle stop control). And the electronic control unit U controls the operation of the fuel injection control device 14, the starter motor 15 and the electric oil pump 13 of the engine E based on these signals, whereby the engine E is controlled to be idle-stopped or restarted. To do.

  As shown in FIG. 2, the electronic control unit U includes a time measuring means M1, a time measuring time determining means M2, a first traveling condition determining means M3, a second traveling condition determining means M4, and an idle stop control means M5. Prepare. A hydraulic switch Sa is connected to the timing means M1, a vehicle speed sensor Sb is connected to the first travel condition determination means M3 and the second travel condition determination means M4, and a fuel injection control device 14 and a starter are connected to the idle stop control means M5. A motor 15 is connected.

  When the engine E is subjected to idle stop control, the oil pump 12 that has been generating the hydraulic pressure equal to or higher than the first threshold PH is stopped, and the hydraulic pressure of the automatic transmission TM is increased with time from the first threshold PH due to oil leakage. Although gradually decreasing, the elapsed time ΔT until the hydraulic pressure decreases from the first threshold PH to the second threshold PL, that is, the elapsed time ΔT until the hydraulic switch Sa in the ON state is turned OFF is counted by the timing means M1. To do. The elapsed time ΔT is a parameter indicating the temperature of the oil. The elapsed time ΔT is shorter as the oil temperature is higher and the viscosity is lower, and the elapsed time ΔT is longer as the oil temperature is lower and the viscosity is higher.

  The time measuring time determination means M2 compares the elapsed time ΔT with a first predetermined time ΔTH and a second predetermined time ΔTL set in advance so that the oil viscosity (temperature) is a viscosity (temperature) that enables idle stop control. It is determined whether or not there is. When the hydraulic pressure falls below the second threshold value PL, the electric oil pump 13 is activated in preparation for the next start to generate the necessary hydraulic pressure for the in-gear of the automatic transmission TM.

  The idle stop control means M5 permits the idle stop control of the engine E if the oil viscosity (temperature) is a viscosity (temperature) enabling the idle stop control, and the oil viscosity is too high (the temperature is too low). Engine E idle when there is a risk of worsening drivability and when oil viscosity is too low (temperature too high) and there is a risk of oil degradation or abnormal wear of lubricated parts. Stop control is prohibited.

  If the oil viscosity is too high (the temperature is too low) and the idle stop control is prohibited, the first running condition determining means M3 determines a predetermined running condition, that is, the vehicle speed detected by the vehicle speed sensor Sb is When the vehicle speed is more than the predetermined vehicle speed and the vehicle speed after the idling stop control is prohibited is calculated by time integration and the mileage of the vehicle is more than the predetermined distance, the oil viscosity has decreased (the temperature has risen sufficiently) ) And the idle stop control is permitted.

  When the idling stop control is prohibited because the oil viscosity is too low (the temperature is too high), the vehicle speed detected by the vehicle speed sensor Sb is determined when the second travel condition determining means M4 determines a predetermined travel condition. When the vehicle speed is less than the predetermined vehicle speed and the idle operation time of the engine E is equal to or longer than the third predetermined time, it is determined that the oil viscosity has increased (the temperature has sufficiently decreased), and the idle stop control is permitted.

  The above operation will be described in more detail based on the flowchart of FIG.

  First, when the idle stop control of the engine E is not prohibited in step S1, that is, when the idle stop control is permitted, it is determined in step S2 whether or not the vehicle state can permit the idle stop control. Specifically, when the shift range is in the “D” range or the “N” range, the vehicle speed detected by the vehicle speed sensor Sb is equal to or lower than the stop determination vehicle speed, and the brake pedal is depressed, the vehicle state is idle. It is determined that the stop control can be permitted. In this case, if there is a request for idle stop control in step S3, measurement of the hydraulic pressure by the hydraulic switch Sa is started in step S4. At this time, since the oil pump 12 is operating, the hydraulic pressure is equal to or higher than the second threshold value PL, and the hydraulic switch Sa is turned on. In step S5, idle stop control is permitted.

  When the engine E is in idling stop in the subsequent step S6, the oil pump 12 is stopped, so that the hydraulic pressure of the automatic transmission TM is gradually reduced due to oil leakage. In step S7, the elapsed time (time from the start of the idle stop control to the OFF of the hydraulic switch Sa) ΔT until the hydraulic pressure becomes less than the second threshold value PL and the hydraulic switch Sa is turned OFF is measured by the time measuring means M1. This elapsed time ΔT is shortened when the viscosity of the oil is low (temperature is high), and is long when the viscosity of the oil is high (temperature is low).

  In subsequent step S8, when it is determined in step S8 that the elapsed time ΔT in the time measurement means M2 is not less than the first predetermined time ΔTH and in step S9 that the elapsed time ΔT is not greater than or equal to the second predetermined time ΔTL, that is, ΔTH ≦ ΔT <ΔTL If the oil temperature is appropriate, the idle stop control means M5 permits the idle stop control in step S10.

  Further, when it is determined in step S8 that the elapsed time ΔT in the time measuring time determination means M2 is not less than the first predetermined time ΔTH and in step S9 that the elapsed time ΔT is greater than or equal to the second predetermined time ΔTL, that is, ΔT ≧ ΔTL. If the oil viscosity is high (temperature is low), the idle stop control means M5 prohibits the idle stop control and starts the engine E in step S11. As a result, the heat of the engine E is transmitted to the automatic transmission TM, the oil is stirred inside the automatic transmission TM, and the oil viscosity of the automatic transmission TM remains high (low temperature) by continuing the idle stop control. Can be prevented.

  Further, when it is determined in step S8 that the elapsed time ΔT in the time measuring time determination means M2 is less than the first predetermined time ΔTH, that is, when ΔT <ΔTH and the oil viscosity is low (temperature is high), In step S12, the idle stop control means M5 prohibits the idle stop control and starts the engine E. Thus, it is possible to prevent the oil viscosity of the automatic transmission TM from being kept low (high temperature) by operating the oil cooler and continuing the idle stop control.

  When the idling stop control of the engine E is prohibited in step S1, the oil viscosity is high (temperature is low) in step S13, and in step S14, the first traveling condition determination means M3 is the vehicle speed sensor Sb. When the detected vehicle speed is equal to or higher than the predetermined vehicle speed and the travel distance from the prohibition of the idle stop control (calculated by time integration of the vehicle speed) is equal to or greater than the predetermined distance, the viscosity of the oil is decreased (the temperature is sufficiently high). In step S17, the idle stop control means M5 permits the idle stop control.

  When the oil viscosity is not high (temperature is low) in step S13 and the oil viscosity is low (temperature is high) in step S15, the second traveling condition determination means M4 detects the vehicle speed sensor in step S16. When the vehicle speed detected in Sb is less than the predetermined vehicle speed and the idle operation state has exceeded the third predetermined time, it is determined that the viscosity of the oil has increased (the temperature has become sufficiently low), and in step S17 the idle speed Stop control means M5 permits idle stop control.

  Next, an example of the above operation will be described based on the time chart of FIG.

  When the driver depresses the brake pedal at time t1, the idle stop control is started at time t2 and the engine E stops. At the same time, the hydraulic switch Sa that is turned on at time t1 When it decreases and becomes less than the second threshold value PL at time t4, it turns OFF. If the elapsed time ΔT from the depression of the brake pedal to the OFF of the hydraulic switch Sa at this time is greater than or equal to the first predetermined time ΔTH and less than the second predetermined time ΔTL, the idle stop control is permitted, but the elapsed time ΔT is the first If it is less than the predetermined time ΔTH, the oil viscosity is too low (the temperature is too high) and the idle stop control is prohibited. If the elapsed time ΔT is equal to or longer than the second predetermined time ΔTL, the oil viscosity is too high (the temperature is Idle stop control is prohibited.

  As described above, according to the present embodiment, since the oil viscosity (temperature) of the automatic transmission TM is measured using the hydraulic switch Sa, it is based on the oil viscosity (temperature) without requiring an oil temperature sensor. It is possible to accurately determine whether the idle stop control is permitted or prohibited. This allows idle stop control to be allowed to deteriorate when oil viscosity is high (temperature is low), or idle stop control to be allowed when oil viscosity is low (temperature is high). It is possible to prevent deterioration and abnormal wear of the lubricated part.

  Moreover, after the idle stop control is prohibited, the idle stop control is permitted because it is estimated that the oil viscosity (temperature) is appropriate based on the vehicle speed, the travel distance, or the duration of idle operation. Control prohibition can be minimized and fuel consumption can be saved.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

For example, the hydraulic pressure detection means of the present invention is not limited to the hydraulic switch Sa of the embodiment, and may be a hydraulic pressure sensor.

E Engine M1 Timekeeping means M2 Timekeeping time determination means M3 First travel condition determination means M4 Second travel condition determination means M5 Idle operation control means PH First threshold value PL Second threshold value Sa Hydraulic switch (hydraulic pressure detection means)
TM Automatic transmission ΔT Elapsed time ΔTH First predetermined time ΔTL Second predetermined time

Claims (1)

Idle that performs idle stop control based on a predetermined condition for an engine (E) connected to an automatic transmission (TM) that establishes a desired shift stage by engaging and disengaging a plurality of friction engagement elements by hydraulic pressure In the engine idling operation control apparatus provided with the operation control means (M5),
Oil pressure detecting means (Sa) for detecting the oil pressure of the automatic transmission (TM);
When controlled in an idle stop state in the engine (E) is the idle operation control means (M5), the hydraulic detecting means (Sa) in the detected hydraulic pressure second threshold from the first threshold value (PH) (PL Time measuring means (M1) for measuring the elapsed time (ΔT) until it decreases to
Time counting means (M2) for determining whether or not the elapsed time (ΔT) timed by the time measuring means (M1) is in a range between a first predetermined time (ΔTH) and a second predetermined time (ΔTL) ;
First traveling condition determination means (M3) for determining that the vehicle speed is equal to or higher than a predetermined vehicle speed and the vehicle travel distance is equal to or greater than a predetermined distance;
Second traveling condition determination means (M4) for determining that the vehicle speed is less than a predetermined vehicle speed and the idle operation state is a third predetermined time or more ;
The idle operation control means (M5) permits the idle stop control when it is determined that the elapsed time (ΔT) is in a range between the first predetermined time (ΔTH) and the second predetermined time (ΔTL), Further, when it is determined that the elapsed time (ΔT) is equal to or longer than the second predetermined time (ΔTL), the engine (E) is started by prohibiting idle stop control, and after the start, When the condition determining means (M3) determines that the vehicle speed is equal to or higher than the predetermined vehicle speed and the vehicle travel distance is equal to or greater than the predetermined distance, the idle stop control is permitted, and the elapsed time (ΔT) is set to the first predetermined time ( If it is determined that it is less than (ΔTH), the engine (E) is started by prohibiting the idle stop control, and after the start, the second traveling condition determination means (M4) determines the vehicle speed. And permits an idle stop control when it is determined that it and idling is lower than the vehicle speed is a third predetermined time or more, the idling control equipment of the engine.

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