JPH07243518A - In-shifting line pressure study control device of automatic transmission of car - Google Patents

Abstract

PURPOSE:To make study control of a line pressure at shifting using parameters which are the most related to a shift shock. CONSTITUTION:An inertia torque Tins is sensed (A) on the basis of the change rate dNe/dtins of the engine rotation in the inertia phase during shifting. On the basis of the degree of throttle opening TVOins in the inertia phase, the reference inertia torque To is set (B). The obtained inertia torque Tins is compared with this reference value To, and the optimum line pressure at shifting is studied (C), and the study correction value PLHO for the line pressure at shifting is set (D1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear shift line pressure learning control device for learning and controlling a line pressure during gear shifting of an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art In an automatic transmission for a vehicle, the discharge pressure of an oil pump is regulated to obtain a line pressure, which is supplied to a hydraulic circuit to operate hydraulic pressure of a torque converter and various transmission elements in a gear type transmission. However, this line pressure is controlled to an appropriate hydraulic pressure according to the engine load (engine output).

That is, it is necessary to adjust the line pressure, which is the source of the operating hydraulic pressure of the torque converter and various speed change elements in the automatic transmission, to an appropriate hydraulic pressure according to the engine load. Since the torque transmission efficiency is increased and engine vibration and shift shock are transmitted to the output shaft, noise and vibration increase. Also,
If the hydraulic pressure is lower than the proper value during shifting, slip will occur,
In addition to the reduction in transmission efficiency, a feeling of extension is generated during a shift, the durability of the automatic transmission is deteriorated, and the fuel economy is further deteriorated.

Therefore, conventionally, there is a map in which an optimum line pressure is determined in advance corresponding to the throttle opening etc. for each type of shift, and the line pressure actuator is driven based on this map to control the line pressure. Was. Further, there has been proposed one in which the line pressure at the time of gear shifting is learned and controlled so that a gear shift shock is almost constant against variations and changes over time of the transmission.

Specifically, for example, Japanese Examined Patent Publication No. Sho 63-3183.
6, the shift time t is measured from the change of the gear ratio before and after the shift, the measured shift time t is compared with the reference time, and the optimum line pressure at the shift is learned. A shift-time line pressure learning control device that controls the line pressure during a shift based on the learning result is shown.

[0006]

However, in such a conventional shift-time line pressure learning control device, the shift time is used as a parameter indicating the magnitude of the shift shock, and the shift shock uses torque ( Since it occurs due to fluctuations in the transmission output shaft torque), an accurate gear shift shock cannot be detected from the gear shift time, which makes it difficult to control the gear shift shock to be almost constant. .

In view of the above-mentioned conventional problems, the present invention controls the line pressure at the time of gear shifting by the parameter most relevant to the gear shift shock so that the gear shift shock can be controlled to be substantially constant. It is an object of the present invention to provide a line pressure control device for shifting.

[0008]

Therefore, according to the present invention, as shown in FIG. 1, an inertia torque detecting means A for detecting an inertia torque during a shift and a reference inertia torque setting means B for setting a reference inertia torque. And the inertia torque detected by the inertia torque detection means A and the reference inertia torque set by the reference inertia torque setting means B are compared, and the optimum line pressure at the time of gear shifting is learned based on the comparison result. The line pressure learning means C and the line pressure control means D for controlling the line pressure by driving the line pressure actuator based on the learning result of the optimum line pressure learning means C at the time of shifting.
And are provided to configure a line pressure learning control device for a vehicle automatic transmission during shifting.

Here, the inertia torque detection means A
Is preferably for detecting inertia torque based on the rate of change of rotation on the input side of the transmission in the inertia phase during gear shifting. Further, it is preferable that the optimum line pressure learning means C learns the optimum line pressure at least for each type of shift.

Further, the optimum line pressure learning means C determines the optimum line when the inertia torque is larger than the reference inertia torque based on the result of comparison between the inertia torque and the reference inertia torque when the shift is an upshift. It is preferable that the pressure is learned in the pressure reducing direction, and the optimum line pressure is learned in the pressure increasing direction when the inertia torque is smaller than the reference inertia torque.

Further, the optimum line pressure learning means C determines the optimum line when the inertia torque is larger than the reference inertia torque, based on the result of comparison between the inertia torque and the reference inertia torque when the shift is a downshift. It is preferable that the pressure is learned in the pressure increasing direction and the optimum line pressure is learned in the pressure reducing direction when the inertia torque is smaller than the reference inertia torque.

Further, when the optimum line pressure learning means C learns at least for each type of shift, the reference inertia torque setting means B sets a reference inertia torque based on at least the type of shift. Good to have. Also, the optimum line pressure learning means C may learn the optimum line pressure for each area defined by at least the engine load.

When the optimum line pressure learning means C learns at least for each engine load area, the reference inertia torque setting means B sets a reference inertia torque based on at least the engine load. Good. Further, the optimum line pressure learning means C learns the optimum line pressure at the time of shifting based on the comparison result of the inertia torque and the reference inertia torque, and stores and holds the learning correction value for the line pressure at the time of shifting. Assuming that the line pressure control means D includes a basic line pressure setting means D1 for setting a basic line pressure based on the type of shift and an engine load, and a learning correction value from a memory holding unit of the optimum line pressure learning means C. And a line pressure calculation unit D3 for calculating the line pressure from the basic line pressure and the learning correction value. The line pressure actuator is driven based on the calculated line pressure. The line pressure should be controlled.

[0014]

Since the magnitude of the shift shock is largely controlled by the inertia torque T _ins (see FIG. 6) in the inertia phase during gear shifting, it is necessary to detect this inertia torque T _ins and match it with the reference inertia torque. By learning the optimum line pressure and controlling it based on this, the shift shock can be controlled to be substantially constant.

In addition, the inertia torque T is calculated based on the rate of change of the rotation on the transmission input side (specifically, the engine speed Ne or the turbine speed Nt) in the inertia phase during gear shifting.
By detecting _ins , it is not necessary to use an expensive torque sensor when detecting the inertia torque T _ins . The inertia torque T _ins can be detected by the rate of change of rotation on the input side of the transmission because the inertia torque T _ins is determined by the following equation, for example.

T _ins = I × dNe / dt I: Engine inertia + Torque converter inertia dNe / dt: Rate of change of engine speed Ne in inertia phase Also, the type of shift (1st speed → 2nd speed, 2nd speed → 3) Since the demand varies depending on the gear stage such as speed and the upshift / downshift, the optimum line pressure is learned for each type of gear shift.

Further, when the shift is an upshift, the clutch is basically a clutch shift, and when the inertia torque is larger than the reference inertia torque, it means that the line pressure is too large. Therefore, the optimum line pressure is reduced. learn. Also, when the shift is a downshift, the shift is basically to release the clutch, and when the inertia torque is larger than the reference inertia torque, it means that the line pressure is too small, so the optimum line pressure is learned in the pressure increasing direction. .

Since the allowable shift shock varies depending on the type of shift, when learning the optimum line pressure for each type of shift, the reference inertia torque is set based on the type of shift. Further, since the demand varies depending on the engine load, the optimum line pressure is learned for each engine load area.

When learning the optimum line pressure for each engine load area, the reference inertia torque is set based on the engine load. Specifically, the reference inertia torque is set to be large on the side where the engine load is large.
This is because if the reference inertia torque is constant, the shift time becomes longer on the side where the engine load is larger. Further, the optimum line pressure at the time of gear shifting is learned, and the learning correction value for the line pressure at the time of gear shifting is stored and held, and the basic line pressure set based on the type of gear shifting and the engine load and the learning correction value are stored. Therefore, by calculating and controlling the line pressure, even if the learning result (learning correction value) is lost for some reason, the minimum control can be performed by the basic line pressure.

[0020]

EXAMPLE An example of the present invention will be described below. Referring to FIG. 2, an automatic transmission 2 is provided on the output side of engine 1. The automatic transmission 2 includes a torque converter 3 interposed on the output side of the engine 1, a gear type transmission 4 connected via the torque converter 3, and a gear type transmission 4
And a hydraulic actuator 5 for performing connection / disconnection operations of various transmission elements therein. The operating oil pressure for the hydraulic actuator 5 is ON / OFF controlled via various electromagnetic valves, but only the electromagnetic solenoid valves 6A and 6B for shifting for automatic shifting are shown here. Reference numeral 7 is an output shaft of the automatic transmission 2.

Here, in order to obtain a line pressure which is an operating oil pressure for the torque converter 3 and the hydraulic actuator 5, an oil pump 8 driven by an input shaft of a gear type transmission is used, an orifice 9 and an electromagnetic valve.
A pressure modifier valve 11 and a pressure regulator valve 12 are provided. Solenoid valve 10
Is subjected to duty control as described later, and pilot pressure is obtained based on the discharge pressure of the oil pump 8 guided through the orifice 9. The pressure modifier valve 11 amplifies its pilot pressure. The pressure regulator valve 12 regulates the discharge pressure from the oil pump 8 to a line pressure proportional to the pilot pressure from the pressure modifier valve 11, and sends it to a hydraulic circuit such as the torque converter 3 and the hydraulic actuator 5.

Signals are input to the control unit 13 from various sensors. The various sensors include the opening degree TVO of the throttle valve 14 of the intake system of the engine 1.
A potentiometer-type throttle sensor 15 is provided for detecting. A crank angle sensor 16 is provided on the crankshaft of the engine 1 or a shaft that rotates in synchronization with the crankshaft. The signal from the crank angle sensor 16 is, for example, a pulse signal for each reference crank angle, and the engine speed Ne is calculated from the period.

Further, the intake system of the engine 1 is provided with a hot wire type air flow meter 17 for detecting the intake air flow rate Qa. From the intake air flow rate Qa and the engine speed Ne, an electronically controlled fuel injection device (fuel injector) is used.
Fuel injection amount T which is the basis of calculation of fuel injection amount by
p = K ₀ × Qa / Ne (K ₀ is a constant) is calculated. Further, a rotation signal is obtained from the output shaft 7 of the automatic transmission 2 to obtain the vehicle speed V.
A vehicle speed sensor 18 for detecting SP (output shaft rotation speed No) is provided.

The control unit 13 is of an integrated type having a CPU for engine control (fuel injection and ignition timing control) and a CPU for automatic transmission control, and the engine speed Ne calculated by the CPU for engine control. , Data such as the basic fuel injection amount Tp can be used by the CPU for automatic transmission control. The automatic transmission control CPU of the control unit 13 mainly performs shift control and line pressure control.

The shift control is performed in conformity with the operation position of the select lever. Particularly, when the select lever is in the D range, the shift control is performed in accordance with the throttle valve opening TVO and the vehicle speed VSP.
The shift positions of the fourth to fourth speeds are automatically set, the ON / OFF combination of the shift electromagnetic valves 6A and 6B is controlled, and the gear type transmission 4 is controlled to the shift position via the hydraulic actuator 5.

The line pressure control is different between the normal operation and the speed change, and during the normal operation, the map on the ROM in which the line pressure is determined according to the throttle opening TVO (or the basic fuel injection amount Tp) as the engine load. , The line pressure PL is determined from the throttle opening TVO, and the line pressure P
An optimum line pressure is obtained by outputting a duty corresponding to L and driving the electromagnetic valve 10 as a line pressure actuator. Here, the line pressure can be increased by increasing the duty (valve opening time ratio).

The line pressure control during the shift is performed by duty-controlling the electromagnetic valve 10 as the line pressure actuator according to the shift-time line pressure learning control routine shown in FIG. Next, the shift line pressure learning control routine of FIG. 3 will be described. It should be noted that this routine is executed every predetermined time. Step 1 (denoted as S1 in the figure. The same applies hereinafter)
Now, input various signals.

At step 2, the value of the in-control flag F ₀ is judged. If the control is not yet started, then F ₀ = 0, so the routine proceeds to step 3. In step 3, it is determined whether or not gear shifting is in progress. This determination is made based on the value of the shifting flag which is set during shifting control by the automatic transmission control CPU.
If the gear is not being changed, this routine is ended. If the gear is being changed, the routine proceeds to step 4, the control flag F ₀ is set to 1, and then the routine proceeds to step 5.

Further, once the control flag F ₀ is set, since F ₀ = 1 in the determination in step 2 when the routine is executed next time, the determination in step 3 is omitted. Go to step 5. In step 5,
It is determined whether it is in the torque phase. In step 6, it is determined whether or not the phase is the inertia phase. That is, after it is determined that the gear change is in progress, the engine speed Ne becomes 1
The inertia phase is started when the engine speed drops by about 00 rpm, and the torque phase is determined from the time when it is determined that the gear is being changed to the time when the drop in the engine speed Ne is detected. The inertia phase is determined from the time when the drop in the engine speed Ne is detected until the CPU for automatic transmission control resets the in-shift flag at the end of the shift control. Therefore, if the determinations at steps 5 and 6 are both NO (neither the torque phase nor the inertia phase), it means that the shift is completed.

If it is determined that the phase is the torque phase, the routine proceeds to step 9, where the shift line pressure control (FIG. 4) is executed. If it is determined that the engine is in the inertia phase, the rate of change of the engine speed Ne at that point in time is dNe / dt.
Is calculated and stored temporarily. Also, step 8
Then, the throttle opening TVO at that time is temporarily stored. After this, the routine proceeds to step 9, where the line pressure control during shifting (FIG. 4) is executed.

The shift line pressure control in step 9 is performed in accordance with the shift line pressure control subroutine shown in FIG. When it is determined to be NO (neither the torque phase nor the inertia phase) in the determinations in steps 5 and 6, it is at the end of the gear shift, and in this case, the process proceeds to step 10 to set the control flag F ₀ to 0. After resetting, the routine proceeds to step 11, where optimum line pressure learning (FIG. 5) is executed.

The optimum line pressure learning in step 11 is shown in FIG.
This is performed according to the optimum line pressure learning subroutine shown in. [Shift Line Pressure Control During Shift] The shift line pressure control subroutine of FIG. 4 will be described. This subroutine corresponds to the line pressure control means.

Because of this line pressure control during shifting, RO
Throttle opening TVO as engine load on M
A map (hereinafter referred to as a basic map) that defines the basic line pressure PL _M for each area of (or basic fuel injection amount Tp) is provided, and the throttle opening TVO (or basic fuel injection amount) as an engine load is also stored in the RAM. A map (hereinafter referred to as a learning map) that defines a learning correction value PL _HO for each area of Tp) is provided. In this case, the RAM retains the stored contents by the backup power source even when the engine key switch is turned off.

In addition, the basic map and the learning map show the types of shifts (1st gear → 2nd gear, 2nd gear → 3rd gear, 3rd gear, 3rd gear on the upshift side).
Speed → 4th speed, 1st speed → 3rd speed, 1st speed → 4th speed, 2nd speed → 4th speed, 4th speed → 3rd speed, 3rd speed → 2nd speed, 2nd speed → 1st speed on the downshift side,
(4th speed → 2nd speed, 4th speed → 1st speed, 3rd speed → 1st speed). In step 101, one is selected from each of a plurality of basic maps and learning maps according to the type of shift.

In step 102, referring to the basic map,
Base line pressure PL _M based on throttle valve opening TVO
Is set by searching. This portion corresponds to the basic line pressure setting means. In step 103, the learning correction value PL _HO is referenced based on the throttle opening TVO with reference to the learning map.
Search (initial value is 0). This portion corresponds to the learning correction value search means.

In step 104, the learning correction value PL _HO is added to the basic line pressure PL _M , and the line pressure PL = PL _M +
Calculate PL _HO . This portion corresponds to the line pressure calculating means. In step 105, the duty corresponding to the line pressure PL is output to drive the electromagnetic valve 10 to obtain the optimum line pressure. [Optimal line pressure learning at the end of gear shift] The optimal line pressure learning subroutine of FIG. 5 will be described.

In step 201, the rate of change dN of the engine speed Ne in the inertia phase in step 7 described above.
A representative value (for example, an average value or a maximum value) is calculated from the stored value of e / dt, and this is defined as dNe / dt _ins . In step 202, the engine speed Ne in the inertia phase is
From the representative value of the change rate of dNe / dt _ins , according to the following equation,
Calculate the inertia torque T _ins .

T _ins = I × dNe / dt _ins (I is a constant equivalent to engine inertia + torque converter inertia) In step 203, a representative value (from the stored value of throttle opening TVO in the inertia phase in step 8 described above) For example, an average value) is calculated, and this is set as TVO _ins .

At step 204, a map on the ROM that defines the reference inertia torque T ₀ for each area of the throttle opening TVO (or the basic fuel injection amount Tp) as the engine load is referred to, and the throttle opening representative in the inertia phase is represented. The reference inertia torque T ₀ is retrieved and set from the value TVO _ins . Note that this reference inertia torque map also shows the type of shift (1st gear → 2nd gear, 2nd gear on the upshift side).
Speed → 3rd speed, 3rd speed → 4th speed, 1st speed → 3rd speed, 1st speed → 4th speed, 2nd speed → 4th speed, 4th speed → 3rd speed, 3rd speed → 2nd speed on the downshift side,
2nd speed → 1st speed, 4th speed → 2nd speed, 4th speed → 1st speed, 3rd speed → 1st speed).

Further, the reference inertia torque T ₀ becomes large on the side where the throttle opening TVO is large. In step 205, it is determined whether the type of shift is an upshift or a downshift. If the shift is an upshift, the process proceeds to step 206, the coefficient K for setting the increasing / decreasing direction is set to 1, and if the shift is a downshift, the process proceeds to step 207. And the coefficient K is −
Set to 1.

In step 206, the inertia torque T
Compare _ins with reference inertia torque T ₀ . T _ins
When> T _0, the routine proceeds to step 209, and the learning correction value PL _HO used during the shift is updated by the following equation (ΔP
Is a positive increment). PL _HO = PL _HO −K · ΔP Therefore, in the case of an upshift, K = 1. Therefore, when the inertia torque T _ins is larger than the reference inertia torque T ₀ , the optimum line pressure is learned in the pressure reducing direction to shift the gear. The learning correction value PL _HO for the line pressure at that time is updated in the decreasing direction.

On the other hand, in the case of downshifting, K = -1. Therefore, when the inertia torque T _ins is larger than the reference inertia torque T ₀ , the optimum line pressure is learned in the pressure increasing direction and the line at the time of shifting is changed. The learning correction value PL _HO for pressure is updated in the increasing direction. If T _ins <T _0, the _routine proceeds to step 210, where the learning correction value PL _HO used during the shift is updated by the following equation (ΔP is a positive increment).

PL _HO = PL _HO + K · ΔP Therefore, in the case of upshift, K = 1, so when the inertia torque T _ins is smaller than the reference inertia torque T ₀ , the optimum line pressure is learned in the pressure increasing direction. Thus, the learning correction value PL _HO for the line pressure during shifting is updated in the increasing direction.

On the other hand, in the case of downshift, K = -1, so when the inertia torque T _ins is smaller than the reference inertia torque T ₀ , the optimum line pressure is learned in the pressure reducing direction and the line pressure at the time of shifting is changed. The learning correction value PL _HO is updated in the decreasing direction. At step 211, the updated learning correction value PL _HO is written and stored in the area corresponding to the throttle opening TVO during gear shift in the learning map selected during gear shift.

The steps 201 to 202 correspond to the inertia torque detection means, the steps 203 to 204 correspond to the reference inertia torque setting means, and the step 20 to
The part 5 to 211 corresponds to the optimum line pressure learning means. In this embodiment, the engine speed change rate dNe / dt is used as the change rate of the rotation on the transmission input side.
Instead of / dt, dNt / dt may be used. Nt is the turbine speed.

[0046]

As described above, according to the present invention, the inertia torque during shifting is detected, the optimum line pressure is learned so as to match the reference inertia torque, and the control is performed based on this learning. The effect that the shift shock can be controlled to be substantially constant is obtained.

Further, by detecting the inertia torque based on the rate of change of the rotation on the input side of the transmission in the inertia phase during gear shifting, it becomes unnecessary to use an expensive torque sensor when detecting the inertia torque. Further, by learning the optimum line pressure for each type of shift, it is possible to cope with a difference in demand depending on the type of shift.

The learning reliability is improved by performing learning depending on the upshift and downshift of the gear shift. Further, by setting the reference inertia torque based on the type of shift, it is possible to cope with the difference in the allowable value of the shift shock depending on the type of shift. Further, by learning the optimum line pressure for each engine load area, it is possible to cope with the difference in demand due to the engine load.

Further, by setting the reference inertia torque based on the engine load, it is possible to more appropriately cope with the difference in the demand depending on the engine load. Further, the optimum line pressure at the time of gear shifting is learned, and the learning correction value for the line pressure at the time of gear shifting is stored and held, and the basic line pressure set based on the type of gear shifting and the engine load and the learning correction value are stored. Therefore, by calculating and controlling the line pressure, even if the learning correction value is lost for some reason, the minimum control can be performed by the basic line pressure, so that the reliability is improved.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention.

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart of a line pressure learning control routine during shifting.

FIG. 4 is a flowchart of a line pressure control subroutine during shifting.

FIG. 5 is a flowchart of an optimum line pressure learning subroutine.

FIG. 6 is a diagram showing characteristics such as torque during shifting.

[Explanation of symbols]

 1 Engine 2 Automatic Transmission 8 Oil Pump 10 Electromagnetic Valve 11 Pressure Modifier Valve 12 Pressure Regulator Valve 13 Control Unit 15 Throttle Sensor 16 Crank Angle Sensor

Claims (9)

[Claims] Claim: What is claimed is: 1. A shift line pressure control device for an automatic transmission for a vehicle for learning and controlling a line pressure during shift, wherein an inertia torque detection means for detecting an inertia torque during a shift and a reference inertia torque are set. Reference inertia torque setting means, comparing the inertia torque detected by the inertia torque detection means and the reference inertia torque set by the reference inertia torque setting means, the optimum line pressure at the time of shifting based on the comparison result. An automatic line shift control means for the vehicle, which comprises an optimum line pressure learning means for learning, and a line pressure control means for controlling the line pressure by driving a line pressure actuator based on the learning result of the optimum line pressure learning means at the time of shifting. Line pressure learning control device for gear shifting. 2. The vehicle according to claim 1, wherein the inertia torque detecting means detects the inertia torque based on a rate of change of rotation on a transmission input side in an inertia phase during gear shifting. Line pressure learning control device for automatic transmission. 3. The shift line of an automatic transmission for a vehicle according to claim 1, wherein the optimum line pressure learning means learns the optimum line pressure at least for each type of shift. Pressure learning control device. 4. The optimum line pressure learning means, based on the result of comparison between the inertia torque and the reference inertia torque, when the shift is an upshift, when the inertia torque is larger than the reference inertia torque, the optimum line pressure is determined. 4. When the shift of the automatic transmission for a vehicle according to claim 3, wherein the optimum line pressure is learned in the pressure increasing direction when the inertia torque is smaller than the reference inertia torque. Line pressure learning control device. 5. The optimum line pressure learning means, based on the result of comparison between the inertia torque and the reference inertia torque, when the shift is a downshift, when the inertia torque is larger than the reference inertia torque, 5. The vehicle automatic shift according to claim 3 or 4, characterized in that the optimum line pressure is learned in the pressure reducing direction when the inertia torque is smaller than the reference inertia torque. Line pressure learning control device for gear shifting. 6. The vehicle according to claim 3, wherein the reference inertia torque setting means sets the reference inertia torque based on at least the type of gear shift. Line pressure learning control device for automatic transmission. 7. The optimum line pressure learning means is for learning the optimum line pressure for each area determined by at least an engine load. Line pressure learning control device for automatic transmission of the vehicle. 8. The shift line pressure learning control for an automatic transmission for a vehicle according to claim 7, wherein the reference inertia torque setting means sets the reference inertia torque based on at least the engine load. apparatus. 9. The optimum line pressure learning means learns an optimum line pressure at the time of shifting based on a comparison result of the inertia torque and the reference inertia torque, and sets a learning correction value for the line pressure at the time of shifting. The line pressure control means includes a basic line pressure setting means for setting a basic line pressure based on the type of shift and an engine load, and a storage holding portion of the optimum line pressure learning means. It has a learning correction value searching means for searching for a learning correction value and a line pressure calculating means for calculating a line pressure from the basic line pressure and the learning correction value, and drives the line pressure actuator based on the calculated line pressure. 9. The shift line pressure learning control device for an automatic transmission for a vehicle according to claim 1, wherein the line pressure learning control device controls the line pressure.