KR100394687B1 - Methold of controlling line pressure in an automatic transmission for vehicles - Google Patents

Abstract

By applying the solenoid valve, the line pressure can be freely adjusted according to the shift stage and the input torque, thereby reducing the excessive oil pressure applied to the oil pump output line, thereby improving the transmission efficiency by reducing the power loss and contributing to improving the fuel efficiency of the vehicle. So that;

A first step of determining whether a shift signal is input when the line pressure control condition is satisfied; A second step of sequentially calculating engine braking torque and turbine torque when it is determined that the shift signal is not input under the condition of the first step; A third step of determining whether the damper clutch is operated after completion of the second step, calculating different hydraulic pressures according to whether the damper clutch is operated, and calculating a final line pressure based on the hydraulic pressure; If it is determined whether the value calculated in the third step is equal to or less than the minimum control value, the duty is determined accordingly, and the solenoid valve for line pressure control is controlled. A fourth step of controlling the valve; If it is determined in the first step that the shift signal is input, the line pressure control of the automatic transmission for a vehicle comprising a fifth step of reading the input shift signal, determine the delay time accordingly and enters a separate shift control routine Provide a method.

Description

Line pressure control method of automatic transmission for vehicle {METHOLD OF CONTROLLING LINE PRESSURE IN AN AUTOMATIC TRANSMISSION FOR VEHICLES}

The present invention relates to a control method for operating a line pressure control device applied to a vehicle automatic transmission hydraulic control system, and more specifically, by applying a solenoid valve to freely adjust the line pressure according to the shift stage and the input torque, It is to improve the transmission efficiency by reducing the load of the pump, and to contribute to the improvement of vehicle fuel economy.

For example, an automatic transmission for a vehicle has a torque converter and a power train, which is a multi-stage transmission gear mechanism connected to the torque converter, and selectively selects one of the operating elements of the power train according to the driving state of the vehicle. It will have a hydraulic control system for operation.

In such an automatic transmission, the hydraulic control system applied to the present invention includes a pressure regulating means for adjusting the oil pressure of the oil pump output line, a manual and automatic shift control means for forming a shift mode, and a smooth shift mode during shifting. Hydraulic control means for adjusting the shifting feel and responsiveness, damper clutch control means for damper clutch operation of the torque converter, and hydraulic distribution means for distributing a proper hydraulic supply to each friction element.

Accordingly, the hydraulic distribution of the hydraulic distribution means is made different by the solenoid valves turned on / off by the transmission control unit and the solenoid valves controlled by the duty, so that the operation of the friction element is selected to realize the shift stage control.

And the regulator valve applied to the pressure control means is to form a line pressure by constantly adjusting the hydraulic pressure of the oil pump output line.

Looking at the conventional configuration of such a regulator valve, as shown in Figure 4, the valve body is the first port 102 receives the flow rate supplied from the oil pump 100, and the hydraulic pressure formed from the first port 102 Operating pressure from the second port 104 for feeding back, the third port 106 for supplying the hydraulic pressure formed in the first port 102 to the torque converter control valve, and the friction elements operating at the forward 3 and 4 speeds. The fourth port 108 to receive the air, the fifth port 110 to receive the D range pressure from the manual valve (not shown), and the sixth port 112 to receive the P and N range pressure from the manual valve (not shown). ) And a seventh port 114 that receives hydraulic pressure from the line pressure line.

In addition, the valve body has a valve spool, which is the first, second, third, four, five, six lands 116, 118, 120, 122 ( 124 and 126.

In addition, one side end of the sixth land 126 of the valve spool is supported by a spring 128, which is supported by the plug 130 to always push the valve spool to the right in the drawing. You will be active.

Accordingly, in the P and N ranges, the control pressure flows through the sixth port 112 to control the line pressure. The control pressure acts on the first land 116 having the largest cross-sectional area, thereby reducing the line pressure. (Approximately 3.5 kg / cm 2), and in the D range 1,2 speeds, the control pressure flows through the fifth port 110 to form a very high line pressure than the P and N ranges (approximately 10.5 kg / cm 2), D In the ranges 3 and 4, additional control pressure flows into the fourth port 108 in the first and second speeds, thereby creating hydraulic pressure in a state lower than the first and second speeds (approximately 8.5 kg / cm 2), Since the control pressure is not supplied in the R range, the highest line pressure is formed (15.5 kg / cm 2) and the line pressure is visually controlled in the state as shown in FIG. 5.

However, in the case of controlling the line pressure as described above, the line pressure is determined by each range or shift stage, so that if one operation state is maintained, the line pressure can maintain one line pressure even if the input torque is changed. do.

That is, even though the line pressure is controlled, it is fixed to any one of the four types of hydraulic pressures, and thus it is impossible to freely control the required hydraulic pressures, thereby causing problems such as fuel consumption loss and power loss caused by the oil pump driving. .

Therefore, the present invention has been invented to solve the above problems, the object of the present invention is to apply the solenoid valve to freely adjust the line pressure according to the shift stage and the input torque, the transmission through the oil pump operating power loss reduction The present invention provides a method for controlling the line pressure of an automatic transmission for a vehicle that can improve efficiency and contribute to fuel efficiency of the vehicle.

1 is a block diagram of a line pressure control device to which the present invention is applied.

Figure 2 is an operation pattern of Figure 1 in accordance with the present invention.

3 is an operational flowchart of a control method according to the present invention;

4 is a block diagram of a conventional line pressure control device.

5 is an operation pattern diagram of a conventional line pressure control device.

In order to realize this, the present invention includes a first step of determining that a shift signal is input when a line pressure control condition is satisfied;

A second step of sequentially calculating engine braking torque and turbine torque when it is determined that the shift signal is not input under the condition of the first step;

A third step of determining whether the damper clutch is operated after completion of the second step, calculating different hydraulic pressures according to whether the damper clutch is operated, and calculating a final line pressure based on the hydraulic pressure;

If it is determined whether the value calculated in the third step is equal to or less than the minimum control value, the duty is determined accordingly, and the solenoid valve for line pressure control is controlled. Otherwise, the solenoid for line pressure control is set to the lowest duty value with the lowest control value. A fourth step of controlling the valve;

If it is determined in the first step that the shift signal is input, the line pressure control of the automatic transmission for a vehicle comprising a fifth step of reading the input shift signal, determine the delay time accordingly and enters a separate shift control routine Provide a method.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described in detail.

1 is a configuration diagram of a line pressure control device to which the present invention is applied, and the oil pressure of the output line of the oil pump 2 is controlled at a constant pressure by the control of the solenoid valve 6 from the regulator valve 4 to control other hydraulic pressures. Supplied to the system.

In this line pressure variable device, the present invention forms the regulator valve (4), the valve body is the first port 10 of the central portion to which the hydraulic pressure is supplied from the oil pump (2), the first port ( The second and third ports 12 and 14 disposed at one side of the second port 10 and returning the hydraulic pressure supplied to the first port 10, and the other side of the first port 10. 10) the fourth port 16 for supplying the hydraulic pressure supplied to the torque converter control valve, the fifth port 18 disposed at the one end of the valve body so as to supply the control pressure for the line pressure, Sixth and seventh ports 20 and 22 disposed between the third port 14 and the fourth port 18 and supplied with N, P, D, 3, 2, and L range pressures from a manual valve (not shown). And an eighth port 24 disposed at one side of the fourth port 16 and receiving a control pressure from the solenoid valve 6.

And a valve spool embedded in the valve body includes: a first land 30 acting on a control pressure supplied to the fifth port 18; A second land 32 acting on the control pressure supplied to the sixth port 20; A third land (34) acting on the control pressure supplied to the seventh port (22), and a fourth land (36) located between the second and third ports (12) and (14); And a fifth land 38 positioned between the first and second ports 10 and 12 and a sixth land 40 for controlling the opening of the fourth port 16.

In addition, one end of the sixth land 40 of the valve spool is supported by a spring 42, which spring 42 is supported by a plug 44 to always push the valve spool to the right in the drawing. You will be active.

The solenoid valve 6 is connected to the line pressure line to supply the line pressure supplied thereto to the control pressure of the regulator valve 4 through the eighth port 24.

Accordingly, the control pressure is supplied to the fifth, sixth, seventh ports 18, 20, and 22 in the P, N, and D ranges, and the control pressure is supplied only through the fifth port 18 in the R range. The line pressure is controlled according to the control of the solenoid valve 6.

The solenoid valve 6 receives information from sensors disposed at each main part of the vehicle in the transmission control unit (TCU) and controls the solenoid valve 6 in comparison with previously input data, thereby controlling the solenoid valve 6. The line pressure variable is made, the control process thereof will be described with reference to FIG.

First, when the engine is started and the operating condition of the engine is determined, whether the oil temperature sensor, the communication system, the inhibitor switch, the solenoid valve 6 is broken, and whether the oil temperature is above a certain temperature, the control condition is determined. (S210).

If the condition is satisfied in step S210, it is determined whether the shift signal is input (S220). If the condition is not satisfied, it is determined whether the oil temperature sensor is faulty (S211). After the control of the time (approximately 10 minutes) is stopped (S212), the process proceeds to step S220 to determine whether a shift signal is input.

In the above, stopping the control for a certain time when the oil temperature sensor is broken is to wait for a sufficient temperature rise of the working oil.

When it is determined that the shift signal is not input in step S220, the engine braking torque TB is calculated (S230), and the turbine torque TT is calculated (S240).

The engine braking torque (TB) calculation in the step S230 is the engine information, that is, the city engine torque calculated from various measured values (intake air amount, intake air temperature, fuel injection amount, ignition advance amount, etc.). torque) and the friction engine torque (Frictonal engine torque), and the formula is TB (kgf.m) = actual engine torque-engine friction torque / 9.8.

In addition, the turbine torque TT is calculated by the formula TT = TB × tr using the engine braking torque value and the torque converter map, where tr is the torque ratio of the torque converter, and the torque ratio map TTRQRTP of the torque converter. ) Is the value read by interpolation according to the value of speed ratio (Nt / Ne).

When the turbine torque calculation is completed through the step S240, it is determined whether the damper clutch is currently operating (S250). Calculate the highest hydraulic pressure according to (S261).

The hydraulic pressure varies depending on whether the damper clutch is operated because the large hydraulic pressure is required regardless of the shift stage when the damper clutch is operated. In step S261, the maximum hydraulic pressure according to the shift stage is calculated at the shift stage. This is because a friction element that requires the largest hydraulic pressure among the operating friction elements must be set as a reference.

In addition, the hydraulic calculation according to the turbine torque (transmission input torque) calculated in the step S240 in the state that the reference value set in consideration of various factors such as the friction coefficient of the friction element, the cross-sectional area, the spring operating load is inputted data It is calculated.

After the oil pressure setting is completed in steps S260 and S261, the final line pressure is set based on the oil pressure (S270). Since the oil pressure calculated in the step is a value according to the input torque, the final line pressure is multiplied by the safety factor. Will yield.

In addition, when the final line pressure is calculated in step S270, it is determined whether the calculated pressure is the minimum control value (3.2 kg / ㎠) or more (S280), if determined to be abnormal, the duty determination according to the calculated value is made When the duty is determined in step S290, the line pressure is adjusted by driving the solenoid valve 6 accordingly (S300).

If it is determined in step S280 that the calculated pressure is less than or equal to the minimum control value, the controller 110 enters the step S300 by setting the minimum control value.

The duty is controlled from the SD to the SF time point in FIG. 2, and the line pressure is not mechanically controlled in four predetermined states as in the prior art, but the control is made in the most ideal state according to the current driving state of the vehicle. You lose.

If it is determined in step S220 that the shift signal is input, the line pressure control duty is controlled to "0" (S221), and after reading the input shift signal to discriminate whether it is upshift or downshift (S222), and based on this. As a result, the delay time Td is determined (S223).

The delay time Td is determined by selecting a signal input in advance according to the up shift, the down shift, and whether the damper clutch is operated.

The delay time depends on the design criteria. In the case of upshift, the responsiveness is not important, so the delay time is long (approximately 144ms), and in the case of downshift, it is short (approximately 96ms). The delay time is the time to wait for the controlled line pressure to return to its original state.

After the delay time has passed, a separate shift control routine enters the shift (S224).

As described above, according to the present invention, by applying a solenoid valve, the line pressure is freely adjusted according to the shift stage and the current operating conditions, so that the line pressure is unnecessarily formed at a high pressure, so that power loss and oil loss in the hydraulic pump are driven. It is an invention that can contribute to improving the fuel efficiency of the vehicle by improving the transmission efficiency through the reduction of flow loss.

Claims (8)

A first step of determining whether a shift signal is input when the line pressure control condition is satisfied; A second step of sequentially calculating engine braking torque and turbine torque when it is determined that the shift signal is not input under the condition of the first step; A third step of determining whether the damper clutch is operated after completion of the second step, calculating different hydraulic pressures according to whether the damper clutch is operated, and calculating a final line pressure based on the hydraulic pressure; If it is determined whether the value calculated in the third step is equal to or less than the minimum control value, the duty is determined accordingly, and the solenoid valve for line pressure control is controlled. A fourth step of controlling the valve; If it is determined that the shift signal is input in the first step, the automatic transmission for a vehicle comprising a fifth step of reading an input shift signal, determining a delay time accordingly, and entering a separate shift control routine. Line pressure control method. 2. The method of claim 1, wherein when the control condition is not satisfied in the first step, it is determined whether the oil temperature sensor is in a failure state. Line pressure control method of a vehicle automatic transmission. The method of claim 1, wherein the control condition in the first step is an oil temperature sensor, a communication system, an inhibitor switch, a solenoid valve, and an oil temperature. The method of claim 1, wherein the engine braking torque in the second stage is calculated by measured actual engine torque and engine friction torque. The line pressure of the vehicular automatic transmission as set forth in claim 1, wherein the turbine torque in the second stage is calculated by the engine braking torque value TB and the torque ratio map TTRQRTP × Nt / Ne of the torque converter. Control method. The method according to claim 1, wherein the final line pressure in the third step is set by multiplying the hydraulic pressure calculated according to the operation of the damper clutch by the safety factor. The line pressure control method for an automatic transmission for a vehicle according to claim 1, wherein the input shift signal in the fifth step is read out according to whether the up shift signal and the down shift signal are applied. The method of claim 1, wherein the delay time of the fifth step is increased in the case of the upshift and shortened in the case of the downshift.