JPH08210483A - Control device for automatic transmission - Google Patents

Abstract

PURPOSE: To effectively reduce a shift shock by constituting an automatic transmission with the first high speed shift to which is engaged a friction engaging device communicating with an accumulator and the second high speed shift to which is engaged a friction engaging device not communicating with the accumulator. CONSTITUTION: A prerequisite condition, for executing squat control for reducing a shock due to rapidly increasing output shaft torque when operated, stopped and run at a low speed a vehicle, is judged for materialized or not. In the case of YES, when shifted from an N range to a D range, a speed change signal of setting the first speed shift is output. Next after a prescribed time, a speed change signal for a speed change to the second speed shift is output, but here is supplied an oil pressure to the third brake B3 from a 2-3 shift valve 71 through an oil path 75 and a B-3 control valve 78. That is, an oil pressure is supplied not via an accumulator 121 or the like, so that the second speed shift can be set without generating a delay.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a shift in an automatic transmission, and more particularly to a control device for executing so-called squat control when switching from a non-running range to a running range.

[0002]

2. Description of the Related Art As is well known, in an automatic transmission for a vehicle, each range such as parking (P), reverse (R), neutral (N) and drive (D) is selected by a shift device, and those ranges are selected. The friction engagement device is appropriately engaged and disengaged according to the above. That is, in the P range and the N range, all the friction engagement devices are set to the released state, or the friction engagement devices other than the specific friction engagement device are released so that the torque is not transmitted to the output shaft. In the R range, hydraulic pressure is supplied to and engaged with a predetermined friction engagement device so as to travel backward. Further, in the D range, hydraulic pressure is supplied to and engaged with a predetermined friction engagement device so as to travel forward.

Therefore, when shifting from a non-running range such as the N range to a running range such as the D range, the output shaft torque suddenly starts from a zero state.
In particular, when shifting from the N range to the D range in the stopped state, the gear speed determined based on the traveling state becomes the first speed because the vehicle speed is zero, and this first speed has the largest gear ratio in the forward speed. Therefore, if the first speed is immediately set when the N range is shifted to the D range, the change range of the output torque becomes extremely large. Therefore, a so-called squat phenomenon in which the rear part of the vehicle body sinks due to torsional elasticity of the power transmission system, etc., and this may deteriorate the riding comfort.

In order to eliminate such inconvenience, conventionally, when shifting from the N range to the D range, a shift for temporarily setting the shift stage on the high speed side is executed to rapidly increase the output shaft torque. Squat control to suppress is performed. Further, in the invention described in JP-A-2-35263, it is determined whether the shift from the N range to the D range is a shift in which the torque is reversed or a shift in which the torque is not reversed, and it is set when shifting from the N range to the D range. The gear position to be changed is changed based on each judgment result.

[0005]

The above-described squat control is performed while setting the shift stage for traveling when the vehicle is substantially stopped and the vehicle shifts from the non-traveling range to the traveling range. This is a control for temporarily setting the high-speed gear stage within a permissible short time period and increasing the torque appearing on the output shaft stepwise or smoothly. Therefore, although the time allowed for this squat control is relatively short, conventionally, it takes a long time to temporarily shift to the high speed stage, and as a result, the output torque changes abruptly. , In some cases, good squat control was not always obtained.

That is, in a normal automatic transmission, an inertial force (inertia) generated by a gear shift is absorbed by sliding a friction engagement device which is engaged to set each gear. For this reason, an accumulator is attached to the hydraulic servo mechanism that engages the friction engagement devices to smooth changes in the hydraulic pressure supplied to and discharged from the hydraulic servo mechanism. Therefore, as a gear stage temporarily set by the squat control, a gear stage for engaging a friction engagement device provided with an accumulator of this kind is adopted.

In that case, the engagement of the frictional engagement device must be slow because the accumulator acts to suppress the supply speed of the hydraulic pressure to the hydraulic servo mechanism. Moreover, the shift time allowed for the squat control is shorter than that for the shift during normal traveling. Therefore, even if a shift to a predetermined high speed stage is executed based on shifting from a non-running range such as the N range to a running range such as the D range, the shift to the first speed or the like is performed before the shift is sufficiently performed. It becomes necessary to set the low speed stage. As a result, there is a possibility that the output torque changes rapidly and the rear portion of the vehicle body sinks and the riding comfort deteriorates.

The present invention has been made in view of the above circumstances, and prevents a delay in the setting of a gear position on the high-speed side which is temporarily passed, and a shock when shifting from a non-driving range to a traveling range. It is an object of the present invention to provide a control device that can effectively reduce the above.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method of changing the speed range from a non-running range to a running range when the vehicle speed is equal to or lower than a predetermined value. A control device for an automatic transmission that executes a shift to a high-speed gear stage, wherein the automatic transmission includes a friction engagement device that is in communication with an accumulator as a higher-speed gear stage than the low-speed gear. A first high speed stage that is set by combining them, and a second high speed stage that is set by engaging a friction engagement device that is not communicated with the accumulator,
The vehicle control system further comprises means for instructing a shift to the second high speed stage as a shift performed based on a change from the non-running range to the running range when the vehicle speed is equal to or lower than the predetermined value. To do.

[0010]

The automatic transmission to which the control device according to the present invention is applied includes a first high speed stage which is set by engaging a friction engagement device communicated with the accumulator and a friction engagement device not communicated with the accumulator. To engage and set the second
It has a high speed stage. When the vehicle speed is switched from the non-running range to the running range when the vehicle speed is equal to or lower than the predetermined value, the shift to be executed based on such a shift is
The shift to the second high speed is instructed.

The friction engagement device that is engaged to set the second high speed stage is supplied with hydraulic pressure without passing through the accumulator and is engaged, so that the engagement speed supplies hydraulic pressure through the accumulator. Faster than you do. Therefore, since the speed change to the second high speed progresses quickly,
Even if the gear is subsequently changed to a low speed determined by the vehicle speed, the output torque does not change rapidly, and the shock accompanying switching to the running range can be reduced.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an overall control system diagram showing an embodiment of the present invention. An engine E to which an automatic transmission A is connected has an intake pipe 12 in which a main throttle valve 13 is provided.
And a sub-throttle valve 14 located upstream thereof. The main throttle valve 13 is connected to an accelerator pedal 15 and is opened / closed according to the amount of depression of the accelerator pedal 15. The sub-throttle valve 14 is opened and closed by a motor 16. An engine electronic control unit (E-ECU) 17 for controlling the motor 16 for adjusting the opening of the sub-throttle valve 14 and for controlling the fuel injection amount and ignition timing of the engine E is provided. There is. The electronic control unit 17 is mainly composed of a central processing unit (CPU), a storage unit (RAM, ROM), and an input / output interface. The electronic control unit 17 stores data for control as Engine (E /
G) Various signals such as rotational speed N, intake air amount Q, intake air temperature, throttle opening, vehicle speed, engine water temperature, and signals from brake switches are input.

In the automatic transmission A, the hydraulic control device 18 controls gear shifting and lockup clutch, line pressure, or engagement pressure of a predetermined friction engagement device. The hydraulic control device 18 is configured to be electrically controlled, and also has first to third shift solenoid valves S1 to S3 for executing a shift and a first to third engine for controlling an engine braking state. 4 solenoid valve S4, linear solenoid valve SLT for controlling the line pressure, linear solenoid valve SLN for controlling the back pressure of the accumulator, linear for controlling the engagement pressure of a lock-up clutch or a predetermined friction engagement device A solenoid valve SLU is provided.

An electronic control unit (T-ECU) 19 for an automatic transmission that outputs a signal to these solenoid valves to control gear shift, line pressure, accumulator back pressure, etc.
Is provided. This automatic transmission electronic control unit 19
Is a central processing unit (CPU) and a storage device (RA
M, ROM) and an input / output interface, and the electronic control unit 19 has a throttle opening, vehicle speed, engine water temperature, a signal from a brake switch, a shift position, as data for control.
A signal from the pattern select switch, a signal from the overdrive switch, a signal from a C0 sensor for detecting the rotational speed of the clutch C0, which will be described later, an oil temperature of the automatic transmission,
Signals from the manual shift switch are input.

The electronic control unit 19 for the automatic transmission and the electronic control unit 17 for the engine are connected to each other so that data can be communicated with each other, and the electronic control unit 17 for the engine transfers to the electronic control unit 19 for the automatic transmission. On the other hand, a signal such as the intake air amount per rotation (Q / N) is transmitted, and an instruction signal for each solenoid valve is sent from the automatic transmission electronic control unit 19 to the engine electronic control unit 17. A signal equivalent to, a signal instructing a shift speed, and the like are transmitted.

That is, the electronic control unit 19 for the automatic transmission
Is based on the input data and the map stored in advance, and the ON / OFF of the gear position and the lockup clutch is performed.
F, or the line pressure or the adjustment level of the engagement pressure is judged, and based on the judgment result, an instruction signal is output to a predetermined solenoid valve, and further judgment of fail or control based on it is performed. . In addition to controlling the fuel injection amount, the ignition timing, the opening degree of the sub-throttle valve 14, etc. based on the input data, the electronic control unit 17 for the engine also sets the fuel injection amount during the shift in the automatic transmission A. The output torque is temporarily reduced by reducing the amount, changing the ignition timing, or narrowing the opening of the sub-throttle valve 14.

FIG. 2 is a diagram showing an example of a gear train of the above-mentioned automatic transmission A, and in the configuration shown here, it is configured to set five forward gears and one reverse gear. That is, the automatic transmission A shown here is used in the torque converter 20.
And a sub-transmission unit 21 and a main transmission unit 22. The torque converter 20 includes a lockup clutch 23.
The lock-up clutch 23 has a front cover 25 that is integrated with the pump impeller 24.
A member (hub) in which the turbine runner 26 and the turbine runner 26 are integrally attached
It is provided between 7 and. An engine crankshaft (not shown) is connected to a front cover 25, and a turbine runner 26 is connected to an input shaft 28.
Is connected to a carrier 30 of an overdrive planetary gear mechanism 29 that constitutes the auxiliary transmission unit 21.

The carrier 3 in this planetary gear mechanism 29
A multi-plate clutch C0 and a one-way clutch F0 are provided between 0 and the sun gear 31. The one-way clutch F0 is engaged when the sun gear 31 rotates forward relative to the carrier 30 (rotates in the rotation direction of the input shaft 28). Further, a multi-plate brake B0 for selectively stopping the rotation of the sun gear 31 is provided.
The ring gear 3 which is an output element of the subtransmission unit 21
2 is connected to an intermediate shaft 33 which is an input element of the main transmission unit 22.

Therefore, in the subtransmission unit 21, the entire planetary gear mechanism 29 rotates integrally when the multi-plate clutch C0 or the one-way clutch F0 is engaged, so that the intermediate shaft 33 has the same speed as the input shaft 28. It will rotate at low speed. Further, in the state where the brake B0 is engaged and the rotation of the sun gear 31 is stopped, the ring gear 32 is accelerated with respect to the input shaft 28 to rotate in the normal direction, and the high speed stage is established.

On the other hand, the main transmission unit 22 is provided with three sets of planetary gear mechanisms 40, 50, 60, and their rotating elements are connected as follows. That is, the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 of the second planetary gear mechanism 50 are integrally connected to each other, and the ring gear 43 of the first planetary gear mechanism 40 and the carrier 52 of the second planetary gear mechanism 50 are connected. The third planetary gear mechanism 60 and a carrier 62 are coupled to each other, and the carrier 62 is coupled to an output shaft 65. Further, the ring gear 53 of the second planetary gear mechanism 50 is connected to the sun gear 61 of the third planetary gear mechanism 60.

In the gear train of the main transmission unit 22, it is possible to set a reverse gear and four gears on the forward side, and clutches and brakes therefor are provided as follows. First, the clutch will be described. The ring gear 53 and the third gear of the second planetary gear mechanism 50 which are connected to each other.
A first clutch C1 is provided between the sun gear 61 of the planetary gear mechanism 60 and the intermediate shaft 33, and the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 and the intermediate shaft of the second planetary gear mechanism 50 are connected to each other. A second clutch C2 is provided between the first clutch 33 and the second clutch C3.

Next, the brake will be described. The first brake B1 is a band brake, and the sun gears 41 and 5 of the first planetary gear mechanism 40 and the second planetary gear mechanism 50 are used.
It is arranged to stop the rotation of 1. A first one-way clutch F1 and a second brake B2, which is a multi-disc brake, are arranged in series between the sun gears 41 and 51 (that is, the common sun gear shaft) and the casing 66. One way clutch F1 is sun gear 41,5
1 engages when trying to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 28). The third brake B3, which is a multi-disc brake, is the first planetary gear mechanism 4
It is provided between the zero carrier 42 and the casing 66. Then, as a brake for stopping the rotation of the ring gear 63 of the third planetary gear mechanism 60, the fourth brake B4, which is a multi-disc brake, and the second one-way clutch F2 are provided in the casing 6.
6 and 6 are arranged in parallel. The second one-way clutch F2 is adapted to be engaged when the ring gear 63 tries to rotate in the reverse direction.

In the above-described automatic transmission A, it is possible to set five forward speeds and one reverse speed by engaging and disengaging each clutch and brake as shown in the operation table of FIG. In FIG. 3, a circle indicates an engaged state, a circle indicates an engaged state during engine braking, a triangle indicates either engaged or disengaged, and blanks indicate a disengaged state.

As shown in the operation table of FIG. 3, the second
To change the speed between the third speed and the third speed, a clutch that changes the engaged / released states of the second brake B2 and the third brake B3 together.
Toe clutch shift. In order to smoothly perform this gear shift, the hydraulic circuit shown in FIG. 4 is incorporated in the hydraulic control device 18 described above.

In FIG. 4, reference numeral 70 indicates a 1-2 shift valve, reference numeral 71 indicates a 2-3 shift valve, and reference numeral 72 indicates a 3-4 shift valve. The communication state of each port of the shift valves 70, 71, 72 at each shift speed is determined by the respective shift valves 70, 71, 7
As shown on the lower side of No. 2. In addition, the number shows each gear stage. A third brake B3 is connected via an oil passage 75 to a brake port 74 that communicates with the input port 73 at the first speed and the second speed among the ports of the 2-3 shift valve 71. Further, an orifice 76 is provided in this oil passage 75.

Reference numeral 78 is a B-3 control valve, and the engagement pressure of the third brake B3 is directly controlled by this B-3 control valve 78. That is, the B-3 control valve 78 includes a spool 79, a plunger 80, and a spring 81 interposed therebetween, and an oil passage 75 is connected to an input port 82 opened and closed by the spool 79. Output port 8 that is selectively communicated with input port 82
3 is connected to the third brake B3. Further, the output port 83 is connected to a footback port 84 formed on the tip side of the spool 79. On the other hand, in the port 85 that opens at the location where the spring 81 is arranged, the port 86 that outputs the D range pressure at the third or higher speed of the 2-3 shift valve 71 is connected via the oil passage 87. It is in communication. A lockup clutch linear solenoid valve SLU is connected to a control port 88 formed on the end side of the plunger 80.

Therefore, the B-3 control valve 78
Is configured such that the pressure regulation level is set by the elastic force of the spring 81 and the hydraulic pressure supplied to the port 85, and the higher the signal pressure supplied to the control port 88, the greater the elastic force of the spring 81. There is.

Further, in FIG. 4, reference numeral 89 is a 2-3 timing valve. The 2-3 timing valve 89 includes a spool 90 having a small diameter land and two large diameter lands and a first plunger. 91, a spring 92 arranged between them, and a second plunger 93 arranged on the opposite side of the first plunger 91 with the spool 90 interposed therebetween. An oil passage 95 is connected to an intermediate port 94 of the 2-3 timing valve 89.
Is the port 9 of the 2-3 shift valve 71 that is communicated with the brake port 74 at the third or higher speed.
6 is connected.

Further, the oil passage 95 is branched on the way to open a port 97 between the small diameter land and the large diameter land.
Is connected via an orifice. The port 98, which is selectively communicated with the port 94 at the intermediate portion, is the oil passage 9
It is connected to the solenoid relay valve 100 via 9. The lock-up clutch linear solenoid valve SLU is connected to the port opened at the end of the first plunger 91, and the second brake B2 is passed through the orifice at the port opened at the end of the second plunger 93. Connected.

The oil passage 87 is for supplying / discharging hydraulic pressure to / from the second brake B2, and a small diameter orifice 101 and an orifice 102 with a check ball are interposed in the middle thereof. Further, the oil passage 103 branched from the oil passage 87 has a large diameter orifice 10 provided with a check ball that opens when the pressure is exhausted from the second brake B2.
4 is interposed, and this oil passage 103 is connected to an orifice control valve 105 described below.

The orifice control valve 105 is a valve for controlling the discharge pressure speed from the second brake B2, and the port 107 formed in the intermediate portion so as to be opened and closed by the spool 106 has the second brake B2.
The oil passage 103 is connected to a port 108 formed below the port 107 in the figure. A port 109 formed above the port 107 to which the second brake B2 is connected in the figure is a port that is selectively communicated with the drain port, and the port 109 is connected to the port 109 via an oil passage 110. The port 111 of the B-3 control valve 78 is connected. The port 111 is a port that is selectively communicated with the output port 83 to which the third brake B3 is connected.

Of the ports of the orifice control valve 105, a control port 112 formed at the end opposite to the spring for pressing the spool 106 is connected to the port 114 of the 3-4 shift valve 72 via the oil passage 113. ing. This port 114 outputs the signal pressure of the third solenoid valve S3 at the shift speed of the third speed or lower, and the fourth speed.
It is a port for outputting the signal pressure of the fourth solenoid valve S4 at a shift speed higher than the high speed. Further, an oil passage 115 branched from the oil passage 95 is connected to the orifice control valve 105, and the oil passage 115 is selectively communicated with the drain port.

The port 11 for outputting the D range pressure at the shift speed of the second speed or lower in the 2-3 shift valve 71.
6 through the oil passage 11 at the port 117 opening at the position where the spring 92 is arranged in the 2-3 timing valve 89.
8 are connected. Also 3-4 shift valve 72
Of these, a port 119, which is communicated with the oil passage 87 at a speed lower than the third speed, is connected to the solenoid relay valve 100 via an oil passage 120.

In FIG. 4, reference numeral 121 indicates an accumulator for the second brake B2, and reference numeral 122 indicates C.
A -0 exhaust valve is shown, and reference numeral 123 is an accumulator for the clutch C0. C-0
The exhaust valve 122 is provided with the clutch C in order to apply the engine brake only in the second speed in the second speed range.
It operates so as to engage 0.

Therefore, according to the hydraulic circuit described above,
If the port 111 of the B-3 control valve 78 communicates with the drain, the engagement pressure of the third brake B3 can be directly regulated by the B-3 control valve 78, and the regulation level can be adjusted by the linear solenoid valve. SLU
Can be changed by If the spool 106 of the orifice control valve 105 is in the position shown in the left half of the figure, the second brake B2 can be communicated with the oil passage 103 through this orifice control valve 105, so that the large diameter orifice 104 is used. Exhaust pressure is possible and therefore the drain speed from the second brake B2 can be controlled.

In the above-described automatic transmission, the third brake B3, which is engaged to set the second speed, has its hydraulic pressure regulated by the B-3 control valve 78 and the linear solenoid valve SLU, not by the accumulator. The third speed is engaged by the hydraulic pressure adjusted by the accumulator 121. Therefore, the control device of the present invention uses the second and third brakes B2,
Focusing on the engagement characteristic of B3, the squat control is executed as follows.

FIG. 5 is a flow chart showing an example of the control routine. First, the input signal is read (step 1), and then it is judged by the flag F whether or not the squat control is in progress (step 2). That is, this flag F is
This is a flag that is set to "1" during squat control.
If the result of the determination in step 2 is "no", it is determined whether or not the precondition for executing the squat control is satisfied (step 3).

As described above, the squat control is a control executed to reduce the shock caused by the abrupt increase of the output shaft torque when the vehicle is stopped or at a low vehicle speed close to the stop. Therefore, it is necessary to perform this squat control, or it is determined whether or not the vehicle is in such a state as a precondition. As this precondition, various conditions can be set as necessary. As an example, the idle switch is ON, the brake signal is ON, the engine water temperature is equal to or higher than a predetermined temperature, and the oil temperature of the automatic transmission is within a predetermined temperature range. It can be adopted as a precondition that the vehicle speed is equal to or lower than a predetermined speed, that the vehicle speed sensor, the NC0 sensor that detects the input rotation speed, and the oil temperature sensor are normal. If any of these conditions is not satisfied, it is determined that the situation is not in the state of executing the squat control, and the control routine is exited without performing the control.

When the precondition for the squat control is satisfied, it is determined whether the control start condition is satisfied. That is, it is determined whether the N range, which is the non-running range, has been shifted to the D range, which is the running range (step 4). If this shift is not being performed, the control routine is exited without performing any particular control, and if it is determined that this shift is being performed, the flag F is set to "1" ( Step 5).

Next, the shift signal for setting the first speed is output (step 6), and it is determined whether the elapsed time T1 from the output is the predetermined reference time α or more (step 7). The control of steps 6 and 7 is executed when it is necessary to temporarily supply oil to the first speed friction engagement device or its oil passage in response to a request from a control other than the squat control. By setting the reference time α to, for example, “0 seconds”, it is possible not to output the shift signal to the first speed.

Next, at step 8, a shift signal for shifting to the second speed is output. That is, the second speed is selected as the high-speed stage that is temporarily passed through as the N range that is the non-running range is shifted to the D range that is the running range. As is known from the operation table of FIG. 3, the second speed is a gear set by supplying hydraulic pressure to the first clutch C1 and the third brake B3. As shown in the hydraulic circuit of FIG. 4, hydraulic pressure is supplied from the brake port 74 of the 2-3 shift valve 71 through the oil passage 75 and the B-3 control valve 78, and the hydraulic pressure is the B-3 control valve. It is controlled by controlling the pressure regulation level of 78 by the linear solenoid valve SLU. Therefore, this third brake B3
When the 2-3 shift valve 71 is switched to the third speed to the fifth speed, the hydraulic pressure is immediately supplied. In other words, the torque capacity is rapidly increased by supplying the hydraulic pressure without passing through a means such as an accumulator that stores a large amount of oil, and the second speed is set without delay.

In the state in which the gear shift instruction to the second speed is output and the squat control is being executed, the flag F is set to "1", so that the determination result of step 2 is "yes". First, it is determined whether or not the termination condition is satisfied. Specifically, it is determined whether the elapsed time T2 after the shift output to the second speed is performed is equal to or longer than a predetermined reference time β (step 9). This reference time β is a fixed time sufficient to achieve the second speed, or a time that can be changed according to various conditions, and is the elapsed time T2.
Is longer than this reference time β, that is, if the result of the determination in step 9 is “yes”, the flag F is reset to zero (step 10) and the squat control is terminated.

If the result of the determination in step 9 is "NO", that is, if the elapsed time T2 after the second speed gear shift signal is output has not reached the reference time β, another control end condition is satisfied. It is judged whether or not (Step 1
1). As the control end condition in this step 11, various conditions can be adopted as needed. For example, if a range other than the D range is selected by the shift device, or the first condition is selected from the neutral state. It can be adopted that the line pressure reduction control for preventing the shift shock at the time of shifting to the high speed is completed.

If this control termination condition is satisfied, the routine proceeds to step 10, where the flag F is reset to zero and the squat control is terminated. If the control end condition is not satisfied, the process returns. In addition, after the squat control is completed because the determination result of step 9 and step 11 is “yes”,
The basic shift control for setting the shift speed according to the traveling state such as the vehicle speed and the throttle opening is executed.

Therefore, according to the control described above, the shift based on the so-called ND shift is the shift to the second speed,
Since the second speed is the gear position for engaging the third brake B3 to which hydraulic pressure is supplied without passing through the accumulator,
There is no delay in shifting to the second speed. Therefore, even if the gear shifts to the first gear based on the basic gear shift control after the lapse of the predetermined time, the second gear is temporarily set in the process, so that the increase in the output shaft torque becomes slow, and as a result, the vehicle body It is possible to prevent a shock such as the rear part of the vehicle sinking.

In the above-described embodiment, since the second speed is the shift stage for engaging the third brake without the accumulator, the shift to the second speed is performed based on the ND shift. However, the present invention is not limited to the above-described embodiment, and when engaging the friction engagement device not through the accumulator at another high speed stage, the shift to the other high speed stage is performed by the N-D shift. It may be performed based on.

Further, according to the present invention, the point is that the shift to the above-described high-speed stage may be executed in association with the shift from the non-running range to the running range, and the shift is from the N range to the D range. Not limited to.

Further, the present invention can be carried out for an automatic transmission or a control system therefor having a gear train or hydraulic circuit different from the gear train or hydraulic circuit shown in FIGS.

[0049]

As described above, according to the present invention,
As the gear stage of the gear shift that is temporarily executed based on switching from the non-driving range to the traveling range, the gear stage that is set by engaging the friction engagement device to which hydraulic pressure is supplied without passing through the accumulator is selected. There is no delay in shifting to that shift stage, and as a result, the output shaft torque does not suddenly increase during so-called squat control, and shock can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a control system of an embodiment of the present invention.

FIG. 2 is a diagram mainly showing a gear train of the automatic transmission.

FIG. 3 is a diagram showing an operation table for setting each shift speed.

FIG. 4 is a diagram showing a part of a hydraulic circuit.

FIG. 5 is a flowchart showing an example of a control routine for squat control according to the present invention.

[Explanation of symbols]

 19 Electronic control device for automatic transmission 78 B-3 control valve 121 Accumulator for second brake A Automatic transmission B2 Second brake B3 Third brake SLU Linear solenoid valve

Claims (1)

[Claims] 1. A control device for an automatic transmission that, when a vehicle speed is changed from a non-running range to a running range while the vehicle speed is below a predetermined value, shifts from a low speed gear determined by the vehicle speed to a high speed gear. In the automatic transmission, the first high speed stage, which is set by engaging the frictional engagement device communicated with the accumulator as the shift stage on the higher speed side than the low speed stage, is not communicated with the accumulator. A second high speed stage that is set by engaging the friction engagement device, and as a gear change that is executed based on the vehicle speed being changed from the non-running range to the running range when the vehicle speed is equal to or lower than the predetermined value, An automatic transmission control device comprising means for instructing a shift to the second high speed stage.