JP3528650B2 - Control device for automatic transmission for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission for a vehicle that automatically shifts gears, and more particularly,
The present invention relates to an apparatus for controlling a line pressure so as to expand a control range of a gear shift transient pressure of a hydraulic friction engagement device within a gear shift period regardless of a guard pressure so that a gear shift transient control can be favorably executed.

[0002]

2. Description of the Related Art An automatic transmission for a vehicle is generally adapted to achieve one gear selected from a plurality of gears in accordance with a combination of operations of a plurality of hydraulic friction engagement devices. In addition, the line pressure prepared as the source pressure of the hydraulic friction engagement device should be as low as possible in a range where slippage of the engaged hydraulic friction engagement device does not occur, particularly during the shift period. In addition, the pressure is adjusted to the guard pressure determined based on the actual input torque of the automatic transmission.

By the way, the above line pressure may be used to control the engagement pressure during the gear shift period of the hydraulic friction engagement device, that is, the gear shift transient pressure. For example, without using an accum back pressure control valve or a dedicated linear solenoid valve for controlling the accum back pressure output from the accum back pressure control line, the line pressure is used as the back pressure of the accumulator of the hydraulic friction engagement device, and This is the case where the line pressure is controlled also in the shift transient control for controlling the shift transient pressure of the hydraulic friction engagement device during the shift period in order to improve the feeling.

[0004]

However, when the line pressure is controlled in the shift transient control as described above, there is a premise that the line pressure cannot fall below the guard pressure. Since the control range of (1) is narrowed and the engagement pressure of the hydraulic friction engagement device involved in gear shifting cannot be made sufficiently low, good gear transition control may not be obtained in some cases.

The present invention has been made in view of the above circumstances, and it is an object of the present invention that the line pressure used as a source pressure of a hydraulic friction engagement device is a line pressure for shift transient control. An object of the present invention is to provide a control device for an automatic transmission for a vehicle, which expands the control range of (1) to obtain good gear shift transient control.

As a result of various studies conducted by the present inventors against the background of the above circumstances, in the automatic transmission, the torque ratio of the hydraulic friction engagement device that achieves the first gear stage is higher than the torque ratio of the hydraulic friction engagement device.
Note that the torque sharing ratio of the hydraulic friction engagement device that achieves the above gear stage may be configured to be low in some cases, and during the shift period from the first gear stage to the second gear stage, automatic shifting is performed. It has been found that even if the line pressure is made lower than the guard pressure determined based on the input torque of the machine, the hydraulic friction engagement device does not slip and the control range of the line pressure for gear shift transient control can be expanded. It was The present invention was made based on such findings.

[0007]

That is, the gist of the present invention is that a hydraulic type that achieves a second gear stage is higher than the torque share of a hydraulic friction engagement device that achieves a first gear stage. In an automatic transmission for a vehicle in which the torque sharing ratio of the friction engagement device is low, a shift transient pressure of the hydraulic friction engagement device that is the source pressure of the hydraulic friction engagement device and is not changed during the shift period. A control device including a line pressure generation device that regulates a line pressure that is changed for control, (a) a guard that is a lower limit value of the line pressure so as not to cause slippage of the hydraulic friction engagement device. Guard pressure determining means for determining the pressure, (b) inertia phase start determining means for determining the start of the inertia phase within the shift period from the first gear to the second gear, and (c) the inertia. The inertia phase is opened by the phase start judgment means. There when it is determined in the guard pressure reducing means for reducing the guard pressure determined by the guard pressure determining means is to include.

[0008]

In this way, when the inertia phase start determination means determines that the inertia phase has started within the shift period from the first gear to the second gear, the guard pressure determination means determines. Since the determined guard pressure is reduced by the guard pressure reducing means, the hydraulic friction engagement device does not slip during the shift period from the first gear stage to the second gear stage, and the shift transient control is performed. The control range of the line pressure for is increased, and good shift transient control can be obtained.

[0009]

Another aspect of the present invention is preferably that the guard pressure determining means determines the guard pressure based on an input torque of the automatic transmission from a preset relationship. The reducing means updates the guard pressure to the second guard pressure determined based on the input torque of the automatic transmission when the inertia phase start determining means determines that the inertia phase has started. With this configuration, the guard pressure for the first gear can be switched to the second guard pressure determined based on the input torque of the automatic transmission when the start of the inertia phase is determined. Compared with the case where the guard pressure for the first gear is switched to the guard pressure for the second gear, the guard pressure does not drop sharply, so there is an advantage that the shift feeling is not impaired.

[0010]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a torque converter 12 connected to an engine 10 of a vehicle, an automatic transmission 14, a differential gear unit 16, and a hydraulic control device or hydraulic control circuit 18 for controlling the shift stages of the automatic transmission 14. , Its hydraulic control circuit 1
The electronic shift control device 20 for controlling the transmission No. 8 is shown. The power output from the engine 10 is transmitted to drive wheels (not shown) via the torque converter 12, the automatic transmission 14, the differential gear device 16, the left and right axles 22 and 24, and the like.

The torque converter 12 is a pump impeller 28 connected to a crankshaft 26 of the engine 10.
A turbine impeller 32, which is connected to the input shaft 30 of the automatic transmission 14 and to which power is transmitted from the pump impeller 28 via fluid, and is fixed to a position-fixed housing 36 via a one-way clutch 34. The fixed impeller 38 and the lock-up clutch 40 that directly connects the pump impeller 28 and the turbine impeller 32 via a damper (not shown) are provided.

The automatic transmission 14 has four forward speeds and one reverse speed.
It is a multi-stage transmission that achieves a high speed gear stage, including the input shaft 30, a set of Ravigneaux type planetary gear set 44, a ring gear 48 that rotates together with a ring gear 46 of the Ravigneaux type planetary gear set 44, and an engine 10. The driving force from the ring gear 4 to the differential gear device 16 or its output.
8 and the differential gear device 16 are provided with a counter shaft 50 that functions as an output shaft that transmits power.

In the Ravigneaux type planetary gear set 44, one set of single pinion planetary gear set 52 and one set of double pinion planetary gear set 54 share a carrier 56 and the ring gear 46. The single pinion planetary gear device 52 is composed of a sun gear 58, a planetary gear 60 attached to the carrier 56, and the ring gear 46. The double pinion planetary gear 54 includes a sun gear 62, a first pinion gear 64 and a second pinion gear 66 that are integrally coupled to each other and rotatably attached to the carrier 56.

Some of the constituent elements of the single pinion planetary gear device 52 and the double pinion planetary gear device 54 are not only integrally connected to each other, but also selectively connected to each other by three clutches C1, C2 and C3. It is supposed to be done. Further, some of the constituent elements of the single pinion planetary gear device 52 and the double pinion planetary gear device 54 are three brakes B1, B2.
Selectively coupled to the housing 36 by B3,
Further, some of those components are engaged with the housing 36 by the two one-way clutches F1 and F2 in the rotational direction thereof. The portions of the torque converter 12 and the automatic transmission 14 other than the counter shaft 50 are arranged symmetrically with respect to the shaft center of the input shaft 30 and the like. The lower side is omitted.

The clutch C, which is a hydraulic friction engagement device
1, C2, C3 and brakes B1, B2, B3 are composed of, for example, a multi-plate clutch, a band brake having one band or two bands with opposite winding directions, and the like By controlling the frictional engagement and disengagement of each of them by the hydraulic control circuit 18 which operates according to the command from the gearbox 20, as shown in FIG. 2, the gear ratio γ (= rotation speed of the input shaft 30 / counter It is possible to obtain four forward gears and one reverse gear having different rotational speeds of the shaft 50. “1ST”, “2ND”, “3RD”,
"4TH" represents the first speed gear, the second speed gear, the third speed gear, and the fourth speed gear on the forward side, respectively, and the gear ratio γ is from the first speed gear to the fourth speed. It gradually becomes smaller toward the higher gear. Further, in FIG. 2, “P”,
“R”, “N”, “D”, “2”, and “L” are alternatively selected by the manual operation of the shift lever 84. The parking (P) range, reverse (R) range, and neutral (N). ) Range, drive (D) range, second (2)
A range and a low (L) range are shown respectively. The P range and the N range are non-running ranges selected when the vehicle is not running, and include the R range, the D range, and the 2 range.
The range and the L range are traveling ranges for moving the vehicle backward or forward. In addition, 2 range, L range,
It is also an engine braking range because it not only increases the driving force of the vehicle but also generates engine braking.

Further, in FIG. 2, the mark ◯ indicates the engaged or activated state, and the mark x indicates the released or non-actuated state. For example, in the D range from the second gear to the third
The upshift to the higher gear is executed by engaging the clutch C2 while maintaining the engagement of the clutch C1. The clutches C1 and C2 are the automatic transmission 1
4 are provided in parallel with each other to transmit the input torque T _{IN of} 4 to the subsequent stage, and the torque sharing rate of the clutch C1 in the above 2 → 3 upshift (the sharing rate when the input torque T _{IN is set} to “1”). Is “1” in the second gear as shown in FIG. 3, but is “0.35” in the third gear.
At the same time, the torque share of the clutch C2 becomes “0.65”. The gear shift between the fourth gear and the third gear is a so-called clutch-to-clutch gear shift realized by the disengagement operation of one of the two friction engagement devices and the engagement operation of the other. Thus, for example, in the 4 → 3 downshift from the fourth gear to the third gear, the clutch C1
The engagement operation and the release operation of the brake B1 are performed in the overlapped state or the underlapped state.

The hydraulic control circuit 18 corresponds to three solenoid valves SV1 to SV3 used for controlling the gear stage of the automatic transmission 14 and the throttle opening TA detected by a throttle opening sensor 76 described later. A linear solenoid valve SLT that generates a control hydraulic pressure P _S of a predetermined magnitude, for example, a linear solenoid valve that generates a hydraulic pressure for controlling the frictional engagement of the lock-up clutch 40, the release of the frictional engagement, and the slip amount thereof. The SLU and an oil temperature sensor 88 that functions as a hydraulic oil temperature detection device that detects the oil temperature T _OIL of the hydraulic oil in the hydraulic control circuit 18 are provided.

The shift electronic control unit 20 includes a CPU 7
0, a RAM 72, a ROM 74, a so-called microcomputer including an input / output interface (not shown), and the like, in which a throttle opening sensor 76 for detecting an opening TA of a throttle valve provided in an intake pipe (not shown) of the engine 10 is provided. , An engine speed sensor 78 for detecting the speed N _E of the engine 10, an input shaft speed sensor 80 for detecting the speed N _T of the turbine impeller 32, that is, a speed N _IN of the input shaft 30, the counter shaft The vehicle speed sensor 82 for detecting the rotational speed N _{C of} 50, that is, the vehicle speed V, the operating position of the shift lever 84, that is, L, S,
A signal indicating the throttle opening TA from an operation position sensor 86 that detects any one of the D, N, R, and P ranges and an oil temperature sensor 88 that detects the temperature of the hydraulic oil in the hydraulic control circuit 18.
A signal representing the engine speed N _E (rpm), a signal representing the input shaft speed N _IN (rpm), a signal representing the output shaft speed N _C (rpm), that is, a vehicle speed V, and an operation position P _ST of the shift lever 84. Signal indicating, hydraulic oil temperature T in hydraulic control circuit 18
A signal representative of _OIL is provided. The CPU 70 of the electronic shift control device 20 processes the input signal while using the RAM 72 in accordance with a program stored in the ROM 74 in advance, and based on the processing result, for example, detects the running state of the vehicle and the electromagnetic opening / closing valve. SV1 to SV
3. Control the linear solenoid valve SLT and SLU.

FIG. 4 is a diagram for schematically explaining the structure of the main part of the hydraulic control circuit 18. 4, the original pressure generator or line pressure generating device 90, the line pressure P was by regulating the value corresponding to the engine load pressure of the hydraulic fluid pumped from a hydraulic pump 92 rotationally driven by the engine 10 _L The hydraulic friction engagement devices C1, C2, C
It is output to the shift valve device 94 or the like as a source pressure of 3, B1, B2, and B3. The manual valve 96 is mechanically connected to the shift lever 84, and switches the line oil pressure P _L in response to a travel range selection operation of the shift lever 84, so that the selected travel range is reached. The corresponding hydraulic pressure, for example, R range pressure, D range pressure, 2 range pressure, and L range pressure is output to the shift valve device 94. Further, the electromagnetic on-off valves SV1 and SV2 output the signal pressure to the shift valve device 94 by being operated by the electronic control device 20 for shifting exclusively for selecting the gear stage.

The shift valve device 94 includes a manual valve 96.
Oil pressure and two first electromagnetic opening / closing corresponding to the driving range from
The hydraulic signals from the valve SV1 and the second solenoid on-off valve SV2
1-2 shifts that are switched during gear shifting based on
Valve, 2-3 shift valve, 3-4 shift valve, etc.
According to the operation shown in FIG. 2, each hydraulic friction engagement device C
Selective engagement hydraulic pressure to 1, C2, C3, B1, B2, B3
Supply to. Those hydraulic friction engagement devices C1, C2, C
Clutches C1, C2, C among 3, B1, B2, B3
3 and the brakes B1 and B2 are
That is, C1 accumulator for reducing the increase in engagement torque
Lator A_C1, C2 accumulator A_C2, C3 Accumulation
Data A_C3, B1 accumulator A_B1, B2 Accumley
Type A_B2Are connected respectively. C1 Accumulation above
Data A_C1And B1 accumulator A _B1And the above C2
Cumulator A_C2, C3 accumulator A_C3, And B
2 Accumulator A_B2And the electronic control unit 20 for shifting.
Line oil pressure P that can be changed by a command from_LBut that
It is supplied as accum back pressure respectively, and shift transition
Engagement hydraulic hose of each hydraulic friction engagement device within the period
For the shift transient control which adjusts the shift transient pressure,
Hydraulic pressure P_LIs changed to improve the shifting feeling.
It has become so.

The shift valve device 94 and the clutch C are used.
1 and C1 accumulator A_C1Between the third electromagnetic
Hydraulic signal from on-off valve SV3 and engagement of brake B1
Pressure P _B1Switch the flow resistance between them based on
The engagement timing of the clutch C1 depends on the vehicle state.
Orifice for adjusting triggering or release timing
With multiple oil passages and oil that switches between these multiple oil passages
An orifice switching valve device 98 having a path switching valve is provided.
Has been.

FIG. 5 explains in detail the line pressure generator 90 of the hydraulic control circuit 18 for generating the line hydraulic pressure P _L which is the original pressure of the hydraulic oil supplied to the clutch C1 and the brake B1. It is a figure. In FIG.
The hydraulic pump 92, which is rotationally driven by the engine 10, sucks the recirculated hydraulic oil through the strainer 100 to send the hydraulic oil to the line pressure regulating valve 102 under pressure.

The line pressure regulating valve 102 is composed of the plunger 11
0 and the axial direction of the plunger 110 in contact with the plunger 110
The input port b and the output port d are movably provided
Spool valve 112 for opening and closing the space, and the spool valve
112 for biasing the valve 112 in the valve closing direction via the spring receiving plate 114.
And a pulling 116, and is provided to its input port b.
The hydraulic pressure of the hydraulic oil supplied from the hydraulic pump 92 is
Supplied from the near solenoid valve SLT to the input port a
Control oil pressure P_SBased on the
The automatic transmission 14 has a size corresponding to the input torque.
In hydraulic pressure P_LRegulate to. Of the line pressure regulating valve 102
The hydraulic pressure of the input port b is fed to the input port c.
It is supplied as back hydraulic pressure. The spring 11
6 urging force W_REG, The land of the spool valve 112
Area of the annular pressure receiving surface of 118 is A _REG1, Above spool valve
Plunge for urging the child 112 toward the valve closing direction of the output port d
Area of the pressure receiving surface of_REG2If so, the above line
Hydraulic pressure P_LIs expressed by the following equation (1). Here, formula (1)
Is the above line hydraulic pressure P_LIs the control hydraulic pressure P_SIn proportion to
It can be generated. Control oil pressure P_SIs en
Jin load or input torque T of the automatic transmission 14_INThe size of
In the normal case of indicating the_LIs hydraulic
Necessary and sufficient within the range where slippage does not occur in the friction engagement device.
Engine load or automatic transmission 14
Input torque T_INNormal pressure adjustment value that corresponds to
Is regulated to.

[0025]

[ _Equation 1] P _L = (A _REG2 / A _REG1 ) · P _S + W _REG / A _REG1 (1)

The linear solenoid valve SLT includes a spool valve element 120 that opens and closes between the input port a and the output port b, and a spring 122 that biases the spool valve element 120 in the valve opening direction. . The aforementioned input port a, a constant pressure P _SOL is supplied, the control as a hydraulic whose constant pressure P _SOL is pressure regulated in response to the exciting current output from the shift electronic control unit 20 to the linear solenoid S _SLT The hydraulic pressure P _S is generated at the output port b. The biasing force that biases the spool valve 120 in the valve closing direction of the output port b in accordance with the exciting current of the linear solenoid S _SLT is F _I , the biasing force of the spring 122 is W _SLT , and the spool valve 120 _Assuming that the area of the annular pressure receiving surface of the land 124 is A _SLT , the oil chamber 128 between the land 124 and the land 126 and the output port b are communicated with each other by the oil passage 130.
Since the hydraulic pressure acting on the annular pressure receiving surface is the control hydraulic pressure P _S , the control hydraulic pressure P _S is expressed by the equation (2).

[0027]

[Equation 2] P _S = W _SLT / A _SLT −F _I / A _SLT (2)

In FIG. 5, the pressure reducing valve 132 is a spool valve element 13 that opens and closes between the input port a and the output port b.
6 and a spring 138 for urging the spool valve element 136 in the valve opening direction, the line hydraulic pressure P _L supplied to the input port a thereof is adjusted to the constant pressure P _SOL , and the output port b thereof is adjusted. And supplies it to the linear solenoid valve SLT, the linear solenoid valve SLU, and the like. The hydraulic pressure of the output port b is supplied to the input port c of the pressure reducing valve 132 as a feedback hydraulic pressure. If the pressure receiving area of the spool valve element 136 communicating with the input port c is A _MOD and the urging force of the spring 138 is W _MOD , the constant pressure P _SOL is a constant pressure expressed by the equation (3). Become.

[0029]

[ _Formula 3] P _SOL = W _MOD / A _MOD (3)

FIG. 6 is a functional block diagram for explaining the main part of the control function of the electronic shift control device 20. Figure 6
In the above, the shift control means 142 causes the vehicle speed V obtained from the vehicle speed sensor 82, the throttle opening TA, the fuel injection amount F, and the intake from the shift map selected in advance corresponding to the travel range selecting operation of the shift lever 84. A shift point control for determining a shift of the automatic transmission 14 and outputting a shift command based on an engine load represented by any one of an air amount Q and an accelerator pedal operation amount, and a shift period of the automatic transmission 14 In step 1, the degree of shift is determined based on the vehicle speed V, and shift transient control is executed to transiently control the engagement hydraulic pressure of the hydraulic friction engagement device involved in the shift to improve the shift feeling.

That is, in the shift point control, the point representing the actual vehicle speed V and the engine load is the shift line on the two-dimensional coordinate formed by the vehicle speed axis representing the actual vehicle speed V and the engine load axis representing the engine load. A shift determination is made based on which of the gear stages the vehicle crosses across and is divided by the shift line. For example, if the points representing the actual vehicle speed V and the engine load cross the high-speed side of the 2 → 3 upshift line, for example, the 2 → 3 upshift is determined. In the above-described shift transient control, for example, in the 2 → 3 upshift, after the engagement of the clutch C2 is started, the vehicle speed V (= N _C ) and the gear ratio G ₂ of the second gear and the engine speed. Based on N _E, that is, the turbine rotation speed N _T (= input shaft rotation speed N _IN ), the start of the inertia phase (the section in which the rotation speed of the rotating member of the automatic transmission 16 is changed for shifting) is determined. , When the start of the inertia phase is determined (at time t _{3 in} FIG. 7), the line pressure P _L is adjusted so that the clutch C2 is smoothly engaged, and the increase of the engagement pressure P _C2 is transitional. When the determination is made based on the vehicle speed V (= N _C ), it is determined whether or not the actual input shaft rotational speed N _IN is synchronized with the input shaft rotational speed after the establishment of the third gear. maximum engagement pressure P _C2 of the clutch C2 in the t ₃ time) in FIG. 7 (= _L) The clutch C2 to fully engaged as.

The line pressure control means 144 sets a line pressure P _L which is the same as the guard pressure P _LGRD determined by the guard pressure determination means 146 or the pressure (P _LGRD + α) which is the _{sum of} the guard pressure P _LGRD and the margin value α. The linear solenoid valve SLT is driven so that the line pressure regulating valve 102 outputs it.
Further, the line pressure control unit 144 changes the line pressure P _L within the shift period in accordance with a signal supplied from the shift control unit 142 for shift transient control, within a range not lower _{than the} guard pressure P _LGRD . The engagement pressure P _{C2 of the} clutch _C2 is controlled in the engagement pressure of the hydraulic friction engagement device involved in the gear shift, for example, in the 2 → 3 up shift.

The guard pressure determining means 146 is used for the automatic transmission 1.
Select the relation according to the actual gear stage from pre-stored plurality of relations every four gear position [P _LGRD = MAP _(T T)], the actual input of the automatic transmission 14 from the selected relationship Based on the torque T _IN, that is, the turbine torque T _T , the guard pressure P _LGRD that increases as the turbine torque T _T increases is sequentially determined, and the line pressure control means 144 is set.
Supply to. The above relationship is for determining a pressure as low as possible within a range that does not cause slippage of the hydraulic friction engagement device that is engaged during the shift period, that is, the hydraulic friction engagement device that is not involved in the shift. That is, it is experimentally obtained in advance for each gear stage of the automatic transmission 14.
Here, the turbine torque T _T is, for example, the engine output speed T _E from the engine speed N _E and the engine load (for example, the throttle valve opening θ) from the relationship [T _E = MAP (N _E , θ)] stored in advance. _E is calculated, and [t = MAP (e)] the actual input / output shaft rotation speed ratio e (= N _T / _{T of the} torque converter 12 from the relationship stored in advance.
It is obtained by calculating the torque ratio t based on N _E ) and multiplying the engine output torque T _E by the torque ratio t.

The inertia phase start determination means 148 determines the vehicle speed.
V (= N_C) And the actual gear ratio G and engine
Rotation speed N_EThat is, the turbine rotation speed N_T(= Input axis
Rotation speed N_IN) And the shift period of the automatic transmission 14 based on
Inertia phase in the space (rotating member of the automatic transmission 16
Start of a section where there is a change in rotation speed due to gear shift
To judge. For example, in a 2 → 3 upshift, the second
Change the gear ratio of the high gear to G ₂, The criterion value is β (= 50r.p.
m value), N_T≤ G₂× N_C-Β is satisfied
The start of the inertia phase is determined based on the fact that the

When the inertia phase start determination means 148 determines that the inertia phase has started, the guard pressure reduction means 150 determines the turbine torque value T _TI at that time.
Storing the relationship [P _LGRD = MAP _(T T)] from on the basis of the turbine torque value T _TI second guard pressure P
_LGRD2 〔 = Calculates the MAP (T _TI)], switch to the guard pressure P lower the than the _LGRD second guard pressure P _LGRD2. Therefore, after the start of the inertia phase is determined, the line hydraulic pressure P _L is regulated by the line pressure regulating means 144 so as not to fall below the second guard pressure P _{LG RD2} .

Hereinafter, the main part of the control operation of the electronic shift control device 20 will be described with reference to FIG. FIG. 8 shows a guard pressure control routine.

In FIG. 8, the guard pressure determining means 14
In SA1 corresponding to 6, select the relationship in accordance with the actual gear stage from a plurality of relations previously stored for each gear position of the automatic transmission 14 [P _LGRD = MAP _(T T)], which is the selected From the relationship, the guard pressure P _LGRD for the second gear is sequentially calculated based on the actual input torque T _{IN of the} automatic transmission 14, that is, the turbine torque T _T. At SA2,
Based on the output of the shift control means 142, it is determined whether or not the shift determination for the 2 → 3 up shift or the shift output is performed. When the determination at SA2 is negative, at SA8, the guard pressure P _LGRD determined at SA1 is output, and the line pressure P _L is _regulated along the guard pressure P _LGRD .

However, if the determination at SA2 is affirmative, whether or not the inertia phase of the 2 → 3 upshift is started at SA3 corresponding to the inertia phase start determination means 148 is N _T ≦ G ₂ It is judged based on the condition that × N _C −β is satisfied. If the determination of SA3 is negative, the SA3 is repeatedly executed to wait. However, if the determination of SA3 is negative, the turbine torque T _THD at the start of the inertia phase is determined and stored in SA4. At the same time, in SA5, the second guard pressure P _{LGRD 2} is calculated based on the turbine torque T _THD at the start of its inertia phase from the relationship [P _LGRD = MAP (T _T )] stored in advance. Then SA6
Then, the guard pressure P _LGRD calculated in SA1 is the second guard pressure P _LGRD2 calculated in SA5.
Is greater than or equal to. If the determination in SA6 is negative, SA8 is executed, but if the determination is affirmative, in SA7, the value of the second guard pressure P _LGRD2 is updated instead of the guard pressure P _LGRD larger than it. , SA8, the updated guard pressure P _LGRD is output. In this embodiment, SA5 to SA7 correspond to the guard pressure reducing means 150.

As described above, according to this embodiment,
Sha phase start determination means 148 (SA3) allows the second gear
Gear (first gear) to third gear (second gear)
It is determined that the inertia phase has started within the gear shift period
Is determined by the guard pressure determination means 146 (SA1).
Guard pressure P_LGRDIs a guard pressure reducing means 150 (SA5
2nd guard pressure P due to SA7)_LGRD2What Reduced
Shift period from the second gear to the third gear
Inside the clutch C1 (hydraulic friction not involved in gear shifting
Slippage of the engaging device) does not occur,
Line pressure for _LThe control range of the
You can get control of delivery.

Further, according to the present embodiment, the guard pressure determining means 146 (SA1) has the preset relation [ _PLGRD =
MAP (T _T )] to determine the guard pressure P _LGRD based on the input torque of the automatic transmission 14, that is, the turbine torque T _T , and the guard pressure reduction means 150 (SA5 to SA7) is an inertia phase start determination means. 148 (SA
2) Determined based on the input torque T _THD of the automatic transmission 14 when the start of the inertia phase is determined by 3)
Since the guard pressure _LGRD is updated to the guard pressure P _{LGRD2 of} , the guard pressure for the second gear is
Automatic transmission 14 when the start of inertia phase is determined
Since it is switched to the second guard pressure P _LGRD2 determined based on the input torque T _THD of, the comparison is made when the guard pressure for the second gear is switched to the guard pressure for the third gear. As a result, the sudden decrease in guard pressure as shown by the broken line in FIG. 7 is eliminated, so that there is an advantage that the shift feeling is not impaired.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other modes.

For example, in the shift transient control of the above-described embodiment, the 2 → 3 upshift has been described, but other shift stages may be used, and the clutch-to-clutch shift of 3 → 4 or 4 →. There is no problem even with a 3-down shift.

Further, in the above-described embodiment, the second guard pressure P is set based on the input torque T _THD of the automatic transmission 14 when the start of the inertia phase is determined within the shift period.
_{Although LGRD2} was calculated and updated as the guard pressure _LGRD of the line pressure P _L , the start of the inertia phase and the above-mentioned calculation of the second guard pressure P _LGRD2 and the update using it are not always timely. Does not have to be an exact match,
There may be some delay.

Further, although the automatic transmission 14 of the above-mentioned embodiment is constructed as the fourth forward speed, the third forward speed or the fifth forward speed is used.
It may be configured as a speed or the like.

The above description is merely one embodiment of the present invention, and the present invention can be modified in various ways without departing from the spirit of the invention.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a vehicle power transmission device including a control device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a shift speed achieved by a combination of operations of friction engagement devices provided in the automatic transmission of FIG.

FIG. 3 is a chart showing a torque sharing rate of a hydraulic friction engagement device that is engaged in a second speed gear stage and a third speed gear stage in the automatic transmission of FIG.

FIG. 4 is a block diagram schematically illustrating a main configuration of a hydraulic control device that controls the automatic transmission of FIG.

5 is a hydraulic circuit diagram for specifically explaining the hydraulic circuit configuration of the line pressure generator of FIG.

FIG. 6 is a functional block diagram illustrating a main part of a control function of the electronic shift control device of FIG.

FIG. 7 is a time chart for explaining the operation of gear shift transient control of the gear shift electronic control device of FIG. 1;

8 is a flowchart illustrating a main part of a control operation of the electronic shift control device of FIG. 1, showing a guard pressure control routine. FIG.

[Explanation of symbols]

14: Automatic transmission 90: Line pressure generator 146: Guard pressure determining means 148: Inertia phase start determination means 150: Guard pressure reducing means C1, C2: Clutch (hydraulic friction engagement device)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshikazu Tanaka, 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor, Toshinari Suzuki, 1 Toyota Town, Aichi Prefecture, Toyota Motor Corporation ( 56) References JP-A-7-269687 (JP, A) JP-A-8-270777 (JP, A) JP-A-10-9377 (JP, A) JP-A-11-132322 (JP, A) JP Flat 11-141672 (JP, A) JP 11-63201 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 59/00-63/48

Claims (2)

(57) [Claims] 1. A vehicle for which a torque share of a hydraulic friction engagement device achieving a second gear is lower than a torque share of a hydraulic friction engagement device achieving a first gear. In an automatic transmission, a line pressure generator that generates a line pressure that is a source pressure of the hydraulic friction engagement device and that is changed during a shift period to control a shift transient pressure of the hydraulic friction engagement device. And a guard pressure determining means for determining a guard pressure which is a lower limit value of the line pressure in order to prevent the hydraulic friction engagement device from slipping, and a control device including: Inertia phase start determining means for determining the start of the inertia phase within the gear shift period to the gear position, and when the inertia phase start determining means determines the start of the inertia phase, it is determined by the guard pressure determining means. Ruga Guard pressure reducing means for reducing the guard pressure,
A control device for an automatic transmission for a vehicle, comprising: 2. The guard pressure determining means determines the guard pressure based on an input torque of the automatic transmission from a preset relationship, and the guard pressure reducing means determines the inertia phase start determination. The control device for an automatic transmission for a vehicle according to claim 1, wherein the guard pressure is switched to a second guard pressure determined based on an input torque of the automatic transmission when the start of the inertia phase is determined by the means. .