KR100354023B1 - Method for controlling fuel of auto transmission in vehicle - Google Patents

Abstract

The present invention relates to a fuel efficiency control method of an automatic transmission for a vehicle to improve fuel efficiency by transmitting and receiving information between an engine control device and a shift control device in a vehicle equipped with an automatic transmission, and the engine speed and throttle opening degree detected when driving and Determining whether the condition of the vehicle speed, etc. is the damper clutch operating condition; if the damper clutch operating condition is not satisfied, the main routine is performed to perform normal control according to the vehicle speed and the throttle opening, and the operation control is performed if the damper clutch operating condition is satisfied. Determining whether the slip amount of the damper clutch has reached the set target slip amount in the state of performing the operation control of the damper clutch, and if it is determined that the slip amount of the damper clutch has reached the target slip amount It is judged that the clutch is completed, and then the engine complete Outputting, and the engine controller performs fuel cutoff and return control by selecting a high rotational speed when the damper clutch operation completion signal is not input from the shift control device, and when the damper clutch operation completion signal is input, the hysteresis is low. Selecting the rotational speed to perform fuel shutoff and return control.

Description

Fuel efficiency control method of automatic transmission for vehicle {METHOD FOR CONTROLLING FUEL OF AUTO TRANSMISSION IN VEHICLE}

The present invention relates to a fuel efficiency control method of an automatic transmission for a vehicle, and more particularly, to a fuel efficiency control method of an automatic transmission for a vehicle to improve fuel efficiency through an information communication between an engine control device and a transmission control device in a vehicle equipped with an automatic transmission. It is about.

In general, the most interesting object in vehicles equipped with automatic transmission or continuously variable transmission is fuel economy improvement.

Therefore, damper clutch deceleration control is gradually applied in an automatic transmission or a vehicle with a continuously variable transmission for the purpose of improving fuel efficiency. Therefore, the automatic transmission or a vehicle having a continuously variable transmission includes an engine and a transmission control unit (TCU). Communication is increasingly needed and a power train control unit is being developed for this purpose.

In particular, in order to improve fuel efficiency, the engine control device uses a lot of fuel cut-off, which means that the fuel cut is operated when the engine speed is higher than the set value when the accelerator pedal is off, and the fuel cut is returned when the engine speed is lower than the set value. In the automatic transmission or the continuously variable transmission, the rotation speed for performing the fuel cutoff is not separately provided depending on whether the damper clutch is operated.

Normally, the engine fuel cut operation and the return rotation speed have a large hysteresis, since the engine speed is increased so that the fuel cut operation speed is not reached when the fuel cut is restored.

However, when the damper clutch is in operation, the engine speed is the same as the turbine speed, so the engine speed does not increase even if the fuel cut is restored. Therefore, it is not necessary to set the fuel cut hysteresis much longer. Fuel cutoff can be applied, which has a great effect on fuel economy.

Until now, the engine control unit on the engine side and the transmission control unit on the transmission side are separated, and the information exchange between each other is extremely limited.

Therefore, since the information exchange between the engine control device and the shift control device is extremely limited in the related art, the engine control device side distinguishes between when the damper clutch is operated and the damper clutch is not operated in the automatic transmission or the continuously variable transmission. Despite having to set the fuel cut-off speed separately, there is a problem that cannot effectively improve fuel efficiency because it is not actually separated.

Accordingly, an object of the present invention is to provide an engine control device to notify an engine controller of an operation signal when a damper clutch is operated and a completion signal when an operation of a damper clutch is completed in a vehicle equipped with an automatic transmission or a continuously variable transmission. It is intended to provide fuel economy improvement by selecting a return speed to perform a fuel cut operation.

1 is a control block diagram of an apparatus for controlling fuel economy of an automatic transmission used in the present invention.

Figure 2 is a flow chart for the fuel efficiency control method of the automatic transmission of the present invention.

Figure 3 is a fuel cut operation and return waveform in accordance with the damper clutch operation of the present invention.

In order to realize the above object, the present invention includes the steps of determining whether the conditions such as the engine speed and the throttle opening degree and the vehicle speed detected during driving is a damper clutch operating condition; Performing normal control according to the vehicle speed and throttle opening by performing a main routine when the damper clutch operating condition is not satisfied in the above step; and performing operation control when the damper clutch operating condition is satisfied; Determining whether the slip amount of the damper clutch has reached the set target slip amount in the state of performing the operation control of the damper clutch in the step; If it is determined that the slip amount of the damper clutch has reached the target slip amount in the above step, determining that the damper clutch is in operation and outputting an operation completion signal to the engine controller; In this step, the engine controller performs fuel cutoff and return control by selecting a high rotational speed when the damper clutch operation completion signal is not input from the shift control device, and when the damper clutch operation completion signal is input, the hysteresis is low. Selecting to perform fuel cutoff and return control.

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention.

1 is a control block diagram of an apparatus for controlling fuel economy of an automatic transmission for a vehicle used in the present invention, comprising: an engine speed detecting unit 11 for detecting a rotational speed of an engine crankshaft variable according to an accelerator pedal operation of a vehicle; A throttle valve opening degree detection unit 12 for detecting an opening degree of a throttle valve whose opening / closing state is changed in association with an operation of the accelerator pedal when the vehicle is decelerated; A vehicle speed detector 13 for detecting a vehicle speed decelerated according to the operation of the accelerator pedal; A damper clutch detector 14 for outputting state information of the damper clutch directly connecting the output of the engine and the turbine in the torque converter; The detected signal is analyzed by a predetermined program to determine whether the engine speed, the vehicle speed, and the opening of the throttle valve satisfy an operating condition of the damper clutch. If the damper clutch is satisfied, the damper clutch is operated to operate the output shaft of the engine. A transmission control device 15 which directly connects the turbine of the torque converter and outputs an operation and operation completion signal of the damper clutch while determining whether the slip amount of the damper clutch has reached the target slip amount; The engine control device 16 receives the damper clutch operation and operation completion signals output from the shift control device 15 and controls the fuel cut operation and the return rotation speed by a predetermined program.

2 is a flowchart of a method for controlling fuel economy of an automatic transmission for a vehicle according to the present invention, the method comprising: detecting engine speed during driving and determining whether the detected engine speed is greater than or equal to a predetermined speed; Detecting the throttle opening degree when the engine speed detected in the step 21 is greater than or equal to the arbitrarily set speed, and determining whether the detected throttle opening degree is less than or equal to the arbitrarily set amount; Determining whether the vehicle speed is equal to or greater than the arbitrarily set vehicle speed when the degree of throttle opening degree is less than or equal to the arbitrarily set amount in the step (22); If it is determined that the vehicle speed is greater than or equal to a vehicle speed set in step 23, determining that the damper clutch is operated and performing operation control; Determining whether the slip amount of the damper clutch has reached the set target slip amount in the state of performing the operation control of the damper clutch in the step 24; If it is determined in step 25 that the slip amount of the damper clutch has reached the target slip amount, determining that the damper clutch is in operation and then outputting an operation completion signal to the engine controller; In step 26, the engine controller determines whether the damper clutch operation completion signal is input from the shift controller; (28) selecting a high rotational speed of fuel cut hysteresis if the damper clutch operation completion signal is not input in the step (27); When the damper clutch operation completion signal is input in the step 27, the fuel cut hysteresis is made to select a low rotational speed (29).

According to the present invention made as described above, when the accelerator pedal is released while the vehicle is running, the shift control apparatus 15 determines the deceleration direct control condition of the damper clutch from the engine speed detection unit 11 to determine the engine of the traveling vehicle. The engine speed is detected and the detected engine speed is determined to be equal to or more than the arbitrarily set engine speed (for example, 1100 RPM) (step 21). For example, below 1100 RPM, the main routine is executed.

However, if the engine speed is arbitrarily set above the engine speed (for example, 1100 RPM), the shift controller 15 detects the throttle valve opening rate when the current pedal is released through the throttle valve opening detection unit 12. Then, it is judged whether or not the detected throttle valve opening rate is arbitrarily set value (for example, 1.2%) (step 22).

In this case, if the throttle valve opening rate is greater than or equal to a predetermined value (for example, 1.2%), the main routine is performed, while if the throttle valve opening rate is less than or equal to a randomly set value (for example, 1.2%), the shift control apparatus In step 15, it is determined whether or not the current vehicle speed set speed (for example, 40 KPH) or more detected by the vehicle speed detecting unit 13 (step 23).

If the detected vehicle speed is not higher than the set speed (for example, 40KPH), the main routine is executed. On the other hand, if the detected vehicle speed is higher than the set speed (for example, 40KPH), it is determined that it is a deceleration direct connection condition of the damper clutch. Thus, the shift control device 15 controls the damper clutch operating unit (not shown) by a predetermined program to perform deceleration direct control of the damper clutch (step 24).

As described above, it is determined whether the amount of slip of the damper clutch detected in the state of performing the deceleration direct control of the damper clutch reaches an arbitrarily set target slip amount (step 25), and as a result of the determination, the amount of slip of the damper clutch detected is the target slip. If the amount does not reach the main routine, the main routine is performed. On the other hand, if the detected amount of slip of the damper clutch has reached the target slip amount, the shift control device 15 determines that the damper clutch is in operation and supplies an operation completion signal to the fuel. The cut-off speed is set separately and output to the engine controller 16 which controls fuel cut-off and return (step 26).

On the other hand, the engine controller 16 determines whether a damper clutch operation completion signal has been input from the shift controller 15 (step 27), and at this time, the engine controller 16 determines from the shift controller 15 When the damper clutch is operated by the input signal, a "1" signal is input when the damper clutch is not operated. The damper clutch is input from the shift control device 15 to the engine controller 15. If the operation completion signal is not detected, a high hysteresis rotation speed is selected to perform fuel cutoff control (step 28). That is, as shown in FIG. 3, for example, the fuel cutoff operation is performed at a rotation speed of about 1600 RPM or more. For example, control is performed such that the fuel cut-off return is performed at a rotation speed of approximately 1200 RPM or less. That is, the fuel cut-off hysteresis is set to approximately 400 RPM. Is that it does not re-enter the fuel shut-off due to the rising number of engine rotation during the fuel cut return.

If the fuel is cut off again, an engine pulsation will create anxiety for the driver.

Therefore, when the damper clutch is not activated, the fuel cut hysteresis is set large so that the fuel cut is not operated at low engine speed.

On the other hand, when a damper clutch operation completion signal is input to the engine controller 16 from the shift controller 15, the engine controller 16 selects a low hysteresis for fuel shutoff to perform fuel shutoff control (step In other words, as shown in FIG. 3, for example, the fuel cut operation is performed at a rotation speed of about 1200 RPM or more, and for example, a fuel cut recovery occurs at a rotation speed of about 1100 RPM or less. The cutoff hysteresis is set to approximately 100 RPM (step 29), because the engine speed and the turbine speed are the same, so that there is no increase in the engine speed due to the fuel cutback.

Therefore, according to the operation of the damper clutch, fuel cutoff can be operated at low engine speed, thereby improving fuel economy.

As described above, according to the present invention, the accelerator pedal is released while driving the vehicle, and the damper clutch operation section is checked according to the vehicle speed and the engine speed from the shift control device under the damper clutch deceleration direct connection control condition to perform deceleration direct control and determine the slip amount. By outputting the operation and operation completion signal of the damper clutch to the engine control device and controlling the fuel cut-off operation and the return rotation speed in accordance with the output and the operation completion signal of the damper clutch, to perform the fuel cut off even at low engine speed This will provide an effect that can improve the fuel economy.

Claims (4)

Determining whether the conditions such as the engine speed, the throttle opening degree, and the vehicle speed detected at the time of operation are a damper clutch operating condition; Performing normal control according to the vehicle speed and throttle opening by performing a main routine when the damper clutch operating condition is not satisfied in the above step; and performing operation control when the damper clutch operating condition is satisfied; Determining whether the slip amount of the damper clutch has reached the set target slip amount in the state of performing the operation control of the damper clutch in the step; If it is determined that the slip amount of the damper clutch has reached the target slip amount in the above step, determining that the damper clutch is in operation and outputting an operation completion signal to the engine controller; In this step, the engine controller performs fuel cutoff and return control by selecting a high rotational speed when the damper clutch operation completion signal is not input from the shift control device, and when the damper clutch operation completion signal is input, the hysteresis is low. The fuel economy control method of an automatic transmission for a vehicle comprising the step of performing the fuel cut-off and return control. The method of claim 1, The operation condition of the damper clutch is a condition of the automatic transmission for the vehicle, characterized in that the detected engine speed is set to a predetermined reference speed or more, the detected throttle opening degree is arbitrarily set below a reference value, and the vehicle speed is set to a predetermined reference vehicle speed or more. Fuel economy control method. The method of claim 1, The hysteresis is set to the change range of the engine speed, the rotation speed of the high hysteresis is a large difference between the fuel cut control speed and the fuel cut return speed, the low hysteresis speed is the fuel cut control speed and fuel cut return A fuel consumption control method for an automatic transmission for a vehicle, characterized in that the difference between the number of revolutions is small. delete