JP3191666B2 - Control device for automatic transmission - 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, and more particularly to a control device for executing so-called clutch-to-clutch shift control together with control of a driving force source such as an internal combustion engine or a motor. Things.

[0002]

2. Description of the Related Art Shifting in an automatic transmission involves a change in rotation of a plurality of rotary elements including an engine, for example. Therefore, in order to reduce shift shock, it is necessary to absorb the inertial force of those and smooth the torque fluctuation. is there. Such control generally controls an engagement pressure or a release pressure of a friction engagement device involved in a shift such as a clutch or a brake to control the friction engagement device. Meanwhile,
The manner of changing the rotation of the engine accompanying the shift is different between the power-on state in which the accelerator pedal is depressed and the power-off state opposite thereto, so that the engagement states of the two friction engagement devices are simultaneously changed. So-called clutches to be implemented
In the case of a two-to-clutch shift, the engagement pressure of the friction engagement device on the engagement side is controlled in accordance with the driving state of the engine during the shift.

That is, in the case of a downshift that is a clutch-to-clutch shift, if the power is on, the engine speed is about to increase. The engine speed is gradually increased (sweep-up) after waiting for the engine speed to increase toward the synchronous speed at the shift stage after the shift. On the other hand, in the power-off state, if the friction engagement device that achieves the shift speed is released, the engine speed decreases, and the engagement pressure of the engagement-side friction engagement device is reduced. Is increased relatively early, and the engine speed is increased toward the synchronous speed at the shift speed after the shift. That is, the engagement pressure of the friction engagement device is controlled in accordance with the tendency of the change in the engine speed during gear shifting.

On the other hand, in order to prevent a shift shock,
Since it is preferable to prevent sudden rotation fluctuations, recently, by controlling the throttle valve of the engine electronically, the engine speed has been controlled together with the control of the hydraulic pressure of the automatic transmission. ing.
One example is described in JP-A-5-231525. The invention described in this publication increases the throttle opening by detecting the downshift when the downshift is performed with the throttle valve closed, thereby reducing the engine speed at the gear position after the downshift. In order to prevent or suppress a rise in line pressure due to a temporary increase in the throttle opening when performing the constant speed shift, assuming a so-called constant speed shift in which a downshift is performed in that state in synchronization with the number. The hydraulic pressure limiting means is provided so as to prevent a shock caused by a sudden increase in torque capacity of the friction engagement device during a downshift.

[0005]

The above-mentioned so-called constant speed shift is selected and executed by, for example, a manual operation of a driver at the time of a downshift substantially in a power-off state. So-called clutch-to-
In the case of a clutch shift, in the power-off state, the engagement pressure of the disengagement-side friction engagement device is relatively quickly increased so as to increase the engine speed toward the synchronous speed at the shift speed after the shift. Sweep up. That is, the control of the oil pressure of the friction engagement device is determined and executed based on the driving state of the engine at the time when the downshift is determined. On the other hand, the engine is controlled to increase the rotation speed based on the fact that the downshift is a constant speed shift. Since the control for increasing the rotation speed is performed by temporarily opening the throttle valve, the engine torque also increases at the same time.

Accordingly, in such a case, the automatic transmission is controlled on the basis of the control content in the power-off state, and the engagement pressure of the engagement-side friction engagement device is increased at the end of the gear shift. The engine opens the throttle opening after the start of shifting and enters the power-on state, and the control of the hydraulic pressure of the automatic transmission and the driving state of the engine do not match. Will rise. As a result, there was a possibility that the shift shock would be worsened.

The present invention has been made in view of the above circumstances, and has as its object to provide a control device that does not cause a shock during a so-called constant speed shift.

[0008]

Means for Solving the Problems and Action Therefor To achieve the above object, the invention described in claim 1 is based on the first aspect.
Friction the coupling device is engaged with the second friction engagement device when a predetermined gear to release the braking engagement pressure of the first frictional engagement device control possible automatic transmission, the automatic transmission of temporarily Ru control increases the rotational speed at a predetermined downshift in the machine
The control apparatus for a vehicle which is connected to driving power source for performing, da Unshifuto whether the control for controlling said predetermined shift is Ru temporarily increases the rotational speed of the driving power source
A transmission determining means for determining whether the row match for have downshift, Sui to gradually boost the engagement pressure of the first frictional engagement device
The-loop control of control content, down-shift determined by the speed change decision means Ru increases the rotational speed of the driving power source control
Varying in the case the case is da Unshifuto and downshift has a performed the control for owl, down to perform the control
In the case of a shift, a power-on down system that does not perform this control
Sweep up the engagement pressure earlier than in the case of
And it is characterized in that it comprises a flop to or greater to Rukakarigo control changing means the sweep-up rate.

Therefore, according to the first aspect of the present invention, a driving force source is provided.
Downshift that controls to temporarily increase the number of revolutions
In this case, the engagement pressure of the first friction engagement device is gradually increased.
Sweep-up control is used for power-on downshifts.
Started earlier than
Is increased. As a result, the shift progresses quickly,
Also, the rotation speed of the driving force source is smooth toward the rotation speed after shifting.
, And the shock associated with the shift can be reduced.

According to a second aspect of the present invention, the first frictional engagement device is engaged at the time of a predetermined shift in which the first frictional engagement device is engaged and the second frictional engagement device is released. Combination
The pressure control can be automatic transmission, the line temporarily Ru control increases the rotational speed at a predetermined downshift in said automatic transmission
The control apparatus for a vehicle which is connected to the power sale driving power source, perform da Unshifuto whether the control for controlling said predetermined shift is Ru temporarily increases the rotational speed of the driving power source
A transmission determining means for determining whether such have downshift, the rotational speed of Daunshifu bets is determined by the speed change decision means driving power source
If the downshift is a control that increases the
Scan boosting the engagement pressure of the front Symbol first frictional engagement device gradually
Rotational speed of the increase divided before Symbol driving force source in conjunction with sweep control
And it is characterized in that it comprises a cooperative control means that perform cooperative control for reducing a slip.

[0011] Thus, in the present invention of claim 2, for temporarily down-shift to the upper temperature the rotational speed of the driving power source, the
By gradually increasing the engagement pressure of the first friction engagement device,
The number of rotations of the driving power source increases,
Increase in the number of rotations of the driving force source by control to increase the number of rotations
And control is performed in a coordinated manner.
You. Therefore, torsion in the power transmission system and the
Shock can be prevented.

[0012]

Next, the present invention will be described more specifically with reference to the drawings. It describes first the overall control system. FIG. 6 is a control system diagram for the engine 1 and the automatic transmission 3. A signal corresponding to the amount of depression of the accelerator pedal 20 is input to the engine electronic control device 21. An electronic throttle valve 23 driven by a throttle actuator 22 is provided in an intake duct of the engine 1. The electronic throttle valve 23 is controlled by the engine control device 21 according to the amount of depression of an accelerator pedal 20. A control signal is output to 22 and the opening is controlled in accordance with the control amount.

An engine speed sensor 24 for detecting the rotation speed of the engine 1, an air flow meter 25 for detecting the amount of intake air, an intake air temperature sensor 26 for detecting the temperature of the intake air, and an opening of the electronic throttle valve 23 a throttle sensor 27 for detecting θ, a vehicle speed sensor 28 for detecting a vehicle speed V from the rotation speed of the output shaft 17, a cooling water temperature sensor 29 for detecting a cooling water temperature of the engine 1, a brake switch 30 for detecting the operation of a brake, a shift An operation position sensor 32 for detecting the operation position of the lever 31 is provided. From these sensors, the engine speed N, the intake air temperature Tha, the electronic throttle valve 2
3, a signal indicating the opening degree θ, the vehicle speed V, the engine cooling water temperature THw, the brake operating state BK, and the operation position Psh of the shift lever 31 is supplied to the engine electronic control device 21 or the shift electronic control device 33. It has become. The shift electronic control unit 33 receives the opening degree θ of the electronic throttle valve 23, the vehicle speed V, the engine coolant temperature THw, the signal of the brake operating state BK, and the signal of the operating position Psh of the shift lever 31. Have been.

A signal representing the turbine rotational speed NT is supplied to a shift electronic control unit 33 from a turbine rotational speed sensor 34 for detecting the rotational speed of the turbine runner. Further, a signal indicating a kick-down operation is transmitted from a kick-down switch 35 that detects that the accelerator pedal 20 has been operated to the maximum operation position.
3 has been entered. Further, a sport mode switch 39 and a constant speed shift switch 40 which are manually operated to output a shift signal are connected to the shift electronic control device 33.

Here, the sports mode switch is a switch for selecting a mode for executing a shift by manual operation or a switch for outputting a shift signal by manual operation, and is disposed on a shift device or an instrument panel (not shown). (For example, see JP-A-6-30
7527, JP-A-6-48216, and JP-A-6-2761). The constant-speed shift switch is a switch for performing a one-step downshift by manual operation, and is attached to an appropriate position such as the center of a steering wheel (not shown). When a downshift is performed by operating these switches, the electronic throttle valve 2
The so-called constant speed shift control 3 is opened based on an output signal from the engine electronic control device 17 to open the accelerator pedal 20 more than the depressed amount, thereby increasing the engine speed Ne to the synchronous speed at the shift stage after the downshift. (See, for example, JP-A-7-215892).

The engine electronic control unit 21 is a so-called microcomputer having a central processing unit (CPU), a storage device (RAM, ROM), and an input / output interface. The CPU uses a temporary storage function of the RAM. While processing input signals in accordance with a program stored in the ROM in advance, various engine controls are executed. For example, controlling the fuel injection valve 36 for controlling the fuel injection amount,
The igniter 37 is controlled for ignition timing control, a bypass valve (not shown) is controlled for idle speed control, and all throttle control including traction control is performed.
An electronic throttle valve 23 is controlled by a throttle actuator 22 and executed.

The shift electronic control unit 33 is also a microcomputer similar to the engine electronic control unit 21 described above, and the CPU uses a temporary storage function of the RAM to input an input signal according to a program stored in the ROM in advance. In addition to the processing, each solenoid valve or the linear solenoid valve of the hydraulic control circuit 38 is driven.
For example, the shift electronic control unit 33 includes a linear solenoid valve SLT for generating an output pressure PSLT having a magnitude corresponding to the opening of the throttle valve 23, a linear solenoid valve SLN for controlling the accumulator back pressure, and The linear solenoid valves SLU are driven to control the slip amount of the lock-up clutch and to control the predetermined clutch or brake engagement pressure during the shift transition in accordance with the progress of the shift and according to the input torque.

The electronic control unit 33 for shifting includes a basic throttle opening .theta. (A throttle opening obtained by converting the amount of depression of an accelerator pedal by a predetermined nonlinear characteristic), a vehicle speed V, and a shift diagram using these as parameters. , The gear position of the automatic transmission 3 and the engagement state of the lock-up clutch are determined, and the hydraulic control circuit 38 determines the gear position and the engagement state so as to obtain the determined gear position and engagement state. 1 to No. When driving the solenoid valves SOL1, SOL2, and SOL3 of No. 3 to generate engine brakes, the operation of No.
The fourth solenoid valve SOL4 is driven.

The automatic transmission 3 in this embodiment is configured to be able to set five forward speeds and one reverse speed, which is shown in a skeleton diagram as shown in FIG. That is, in FIG. 7, the automatic transmission 3 is connected to the engine 1 via the torque converter 2. The torque converter 2 has a pump impeller 5 connected to a crankshaft 4 of the engine 1, a turbine runner 7 connected to an input shaft 6 of the automatic transmission 3, and a direct connection between the pump impeller 5 and the turbine runner 7. And a stator 10 whose rotation in one direction is prevented by a one-way clutch 9.

The automatic transmission 3 has a high and a low
The vehicle is provided with a sub-transmission unit 11 for switching gears, and a main transmission unit 12 for switching between a reverse gear position and four forward gear positions. The auxiliary transmission unit 11 includes a sun gear S0, a ring gear R0,
And an HL planetary gear unit 13 comprising a pinion P0 rotatably supported by the carrier K0 and meshed with the sun gear S0 and the ring gear R0, a clutch C0 and a one-way clutch provided between the sun gear S0 and the carrier K0. F0 and a brake B0 provided between the sun gear S0 and the housing 19.

The main transmission unit 12 includes a first planetary gear unit 14 comprising a sun gear S1, a ring gear R1, and a pinion P1 rotatably supported by the carrier K1 and meshed with the sun gear S1 and the ring gear R1.
A second planetary gear set 15 comprising a pinion P2 rotatably supported by the sun gear S2, the ring gear R2 and the carrier K2 and meshed with the sun gear S2 and the ring gear R2; a sun gear S3 and a ring gear R3;
And a third planetary gear set 16 comprising a pinion P3 rotatably supported by the carrier K3 and meshed with the sun gear S3 and the ring gear R3.

The sun gear S1 and the sun gear S2 are integrally connected to each other, and the ring gear R1, the carrier K2, and the carrier K3 are integrally connected to each other.
Is connected to the output shaft 17. Also, the ring gear R2
Are integrally connected to the sun gear S3. A first clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 18, and a second clutch C2 is provided between the sun gear S1 and the sun gear S2 and the intermediate shaft 18.

A first brake B1 in the form of a band for stopping the rotation of the sun gear S1 and the sun gear S2 is provided on the housing 19 as a braking means. The sun gear S1 and the sun gear S2 and the housing 19
Between the first one-way clutch F1 and the brake B
2 are provided in series. This first one-way clutch F
1 is configured to be engaged when the sun gear S1 and the sun gear S2 try to reversely rotate in the direction opposite to the input shaft 6.

A third brake B3 is provided between the carrier K1 and the housing 19, and a fourth brake B4 and a second one-way clutch F2 are provided between the ring gear R3 and the housing 19 in parallel. Have been. This second
The one-way clutch F2 is configured to be engaged when the ring gear R3 attempts to rotate in the reverse direction. The clutches C0, C1, C2, the brakes B0, B1, B2
, B3, B4 are hydraulic friction engagement devices in which friction materials are engaged by the action of hydraulic pressure.

In the above automatic transmission, five forward speeds and reverse speeds can be set, and the engagement and disengagement states of the respective friction engagement devices for setting these shift speeds are shown in FIG. It is shown in the joint operation table. In FIG. 8, a mark “○” indicates an engaged state, and a mark “X” indicates a released state.

FIG. 9 shows the operating position of the shift lever 31. In the drawing, a combination of six operation positions in the front-rear direction of the vehicle and two operation positions in the left-right direction of the vehicle allows the shift lever 31 to be operably supported by the shift lever 31 in eight operation positions. Supported. And P is the parking range position, R
Is the reverse range position, N is the neutral range position,
D is a drive range position, “4” is a “4” range position for setting a shift speed up to the fourth speed, “3” is a “3” range position for setting a shift speed up to the third speed, and “2” is L indicates a "2" range position for setting a shift speed up to the second speed, and L indicates a low range position at which an upshift to the first or higher speed is prohibited.

As shown in FIG. 8, the automatic transmission 3 is
The shift between the second speed and the third speed is a clutch-to-clutch shift that switches both the engagement states of the third brake B3 and the second brake B2. In the shift control, it is necessary to control the friction engagement device involved in the shift to the underlap or overlap state according to the power on / off state and the shift up / down state. It is necessary to control the hydraulic pressure of the second brake B2 according to the input torque, and to control the hydraulic pressure of the third brake B3 based on the progress of the shift. Therefore, the hydraulic control circuit 38 incorporates a circuit shown in FIG. 10 in order to execute this shift smoothly and quickly, and its configuration will be briefly described below.

In FIG. 10, reference numeral 70 denotes a 1-2 shift valve, reference numeral 71 denotes a 2-3 shift valve, and reference numeral 72 denotes a 3-4 shift valve. The communication state of each port of these shift valves 70, 71, 72 at each shift speed is determined by the respective shift valves 70, 71,
72 is as shown below. The numbers indicate the respective gears. A third brake B3 is connected via an oil passage 75 to a brake port 74 communicating with the input port 73 at the first speed and the second speed among the ports of the 2-3 shift valve 71. An orifice 76 is interposed in this oil passage, and the orifice 76 and the third brake B
3 and a damper valve 77 is connected. This damper valve 77 absorbs a small amount of hydraulic pressure when the line pressure is rapidly supplied to the third brake B3 to perform a buffering action.

Reference numeral 78 denotes a B-3 control valve, and the engagement pressure of the third brake B3 is directly controlled by the 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 selectively connected to input port 82
3 is connected to the third brake B3. Further, the output port 83 is connected to a feedback port 84 formed on the distal end side of the spool 79. On the other hand, among the ports 85 of the 2-3 shift valve 71, a port 86 for outputting the D range pressure at the third or higher speed is provided through an oil passage 87. Are in communication. A lock-up clutch linear solenoid valve SLU is connected to a control port 88 formed at the end of the plunger 80.

Therefore, the B-3 control valve 78
The pressure adjustment level is set by the elastic force of the spring 81 and the hydraulic pressure supplied to the port 85, and the elastic force of the spring 81 increases as the signal pressure supplied to the control port 88 increases. I have.

Further, in FIG. 10, reference numeral 89 denotes a 2-3 timing valve.
A spool 90 and a first plunger 91 forming a small-diameter land and two large-diameter lands, and a spring 92 disposed therebetween and a first plunger 91 are disposed opposite to the first plunger 91 with the spool 90 interposed therebetween. And a second plunger 93. An oil passage 95 is connected to a port 94 at an intermediate portion of the 2-3 timing valve 89.
Is the port 9 of the 2-3 shift valve 71 which is connected to the brake port 74 at the third or higher speed.
6 is connected.

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

The oil passage 87 is for supplying and discharging hydraulic pressure to and 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. The oil passage 103 branched from the oil passage 87 has a large-diameter orifice 10 having a check ball which opens when the pressure is released from the second brake B2.
The oil passage 103 is connected to an orifice control valve 105 described below.

The orifice control valve 105 is a valve for controlling the speed of the pressure release from 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 selectively communicated with a drain port. The port 111 of the B-3 control valve 78 is connected. The port 111 is a port selectively connected to the output port 83 to which the third brake B3 is connected.

A control port 112 formed at an end of the port of the orifice control valve 105 opposite to the spring for pressing the spool 106 is connected to a port 114 of the 3-4 shift valve 72 via an oil passage 113. ing. The port 114 is a port for outputting the signal pressure of the third solenoid valve SOL3 at the third or lower speed, and outputting the signal pressure of the fourth solenoid valve SOL4 at the fourth or higher 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 connected to a drain port.

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

In FIG. 10, reference numeral 121 denotes an accumulator for the second brake B2.
An accumulator control pressure regulated according to the hydraulic pressure output from the linear solenoid valve SLN is supplied. The accumulator control pressure is controlled in accordance with the input torque, and the linear solenoid valve S
The lower the output pressure of LN, the higher the pressure. Therefore, the transient hydraulic pressure for engagement / disengagement of the second brake B2 changes at a higher pressure as the signal pressure of the linear solenoid valve SLN is lower. Further, by temporarily lowering the signal pressure of the linear solenoid valve SLU, the engagement pressure of the second brake B2 can be temporarily increased.

Reference numeral 122 denotes a C-0 exhaust valve, and reference numeral 123 denotes an accumulator for the clutch C0. C-0 exhaust valve 1
Reference numeral 22 designates an operation for engaging the clutch C0 to apply the engine brake only in the second speed in the second speed range.

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 pressure regulation level is controlled by a linear solenoid valve. SLU
Can be changed by If the spool 106 of the orifice control valve 105 is located at the position shown in the left half of the figure, the second brake B2 is connected to the oil passage 103 through the orifice control valve 105. Relieving pressure is possible, so that the drain speed from the second brake B2 can be controlled.

The engagement pressure of each friction engagement device in the above-described automatic transmission 3 is a pressure determined by the line pressure controlled according to the throttle opening θ in the engine 1.
For example, the engagement pressure PB3 of the third brake B3 during a shift between the second speed and the third speed, which is a clutch-to-clutch shift.
Is controlled based on the progress of the shift. For example, the third
In the case of a downshift from the second speed to the second speed, the third brake B
3 is engaged, the engagement pressure of the third brake B3 is changed to the synchronous speed of the second speed if the power-off state in which the throttle valve 23 is closed at the time of shifting determination. If the throttle valve 23 is opened in the power-on state, the pressure is maintained at a low pressure and the engine speed approaches the second speed synchronous speed. The pressure is gradually increased (swept up). By controlling in this way, rapid fluctuations in the engine speed before and after reaching the second speed synchronous speed are suppressed, and shift shock is prevented.

The engine 1 to which the above-mentioned automatic transmission 3 is connected is equipped with the above-mentioned sports mode switch 3.
9 or by manually operating the constant speed shift switch 40, if the throttle valve 23 is closed and the power is off at the time of the shift determination, the engine speed is reduced. The downshift is executed in a state where the speed is increased to about the synchronous speed in the step. Such a driving state does not correspond to any of the above-described power-on state and power-off state in the case of the downshift from the third speed to the second speed, and is controlled as described below.

FIG. 1 is a flowchart for explaining the downshift from the third speed to the second speed in three modes. After performing the processing of the input signal (step 10), a so-called clutch-to-foot is executed.・ Third clutch shifting
A downshift from the first speed to the second speed is determined (step 11). If a negative determination is made in step 11,
The routine returns without performing any particular control. If the determination is affirmative, it is determined whether or not the sport mode is set (step 12). Therefore, steps 11 and 12 correspond to the shift detecting means in the present invention.

As described above, the sport mode is a shift mode in which a shift is performed based on a switch operation. As a form of the switch, each shift position is provided in a shift device, and a shift lever is provided at each shift position. A switch that is turned on by a switch, or a sports mode state is set, and in this state, an upshift switch or a downshift switch is turned on by a shift lever, and a steering wheel or an instrument panel Some have a down switch. Therefore step 1
The judgment of No. 2 may be made by judging the presence / absence of signal output from these switches.

If a negative determination is made in step 12 because the downshift is due to a change in the running state, it is determined whether or not the vehicle is in the power-on state (step 13). That is, it is determined whether the electronic throttle valve 23 is open and the vehicle is being driven by the output of the engine 1, and this can be determined based on the throttle opening θ.

If an affirmative determination is made in step 14 due to the power-on state, the shift is executed by the release control of the second brake B2 and the engagement control of the third brake B3 as described above (step 14). ). In that case,
Since the engine 1 is in the driving state, the engine speed, that is, the input speed NC0 increases due to the decrease in the engagement pressure of the second brake B2 that has set the third speed. Therefore, the engagement pressure PB3 of the third brake B3 for achieving the second speed is controlled according to the pattern I shown in FIG. 2 (step 15).

That is, at the time t2 when a predetermined T1 second has elapsed from the time t1 when the shift determination from the third speed to the second speed has been established, the duty of the linear solenoid valve SLU for determining the pressure adjustment level of the third brake pressure PB3 is determined. The ratio is increased for a predetermined time until time t3, and initial hydraulic pressure control for reducing the pack clearance is performed. After that, the input rotation speed NC0 becomes the second
The duty ratio is maintained at a small value until time t4 when the rotation speed increases to a rotation speed smaller than the synchronous rotation speed by a predetermined rotation speed Δα, and the third brake pressure PB3 waits at a low pressure. Then, the third brake pressure PB3 is gradually increased (sweep-up) by gradually increasing the duty ratio of the linear solenoid valve SLU, and at the time t5 when the input rotational speed NC0 reaches the synchronous rotational speed, the third brake B3 is activated. Fully engage.
By performing such control, the engine speed is prevented from suddenly changing before and after reaching the second speed synchronous speed after the downshift, and shift shock is improved.

In the case of the above-mentioned downshift in the power-on state, at the end of the shift, control for reducing the engine torque by retarding the ignition timing or the like, or temporarily release the release pressure of the second brake B2 on the release side. Control for increasing the output torque to reduce the output torque is executed.

On the other hand, if the result of the determination in step 13 is negative due to the power-off state, a shift control for releasing the second brake B2 and engaging the third brake B3 is executed (step 16). At the same time, the engagement pressure of the third brake B3 is controlled according to the pattern II shown in FIG. 3 (step 17).

That is, the point in time t when the control of the initial hydraulic pressure ends.
After 3, the duty ratio of the linear solenoid valve SLU is gradually increased at time t6 when the input speed NC0 is considerably lower than the synchronous speed of the second speed, and the third brake B
3 gradually increase the engagement pressure PB3. After the time point t7 when the third brake pressure PB3 has become sufficiently high, the input rotational speed NC0, that is, the engine rotational speed reaches the synchronous rotational speed of the second speed. Therefore, in the case of a downshift from the third speed to the second speed in the power-off state, the engagement pressure PB3 of the third brake B3 is increased at an early stage, and the rotation speed of the engine 1 is input from the output shaft side. In addition to raising the speed by the torque, the shift speed is rapidly advanced, and the input speed NC0 is smoothly changed toward the synchronous speed to improve the shift shock.

If an affirmative determination is made in step 12 because the downshift is in the sports mode,
A constant speed shift is executed (step 18). This constant speed shift is a shift control in which the engine speed Ne is increased to the synchronous speed at the shift speed after the downshift, and the downshift is executed in that state. It is performed by temporarily opening by.

The throttle opening θ and the third brake pressure P
Cooperation control with B3 is executed (step 19), and the third brake pressure PB3 is controlled according to the pattern III shown in FIG. 4 (step 20). Note that the above step 1
5, 17 and 20 correspond to the engagement control changing means in the first aspect of the present invention.

The essential point of the cooperative control in step 19 is that the engine speed Ne at the time of downshifting to the second speed with the throttle opening θ increased is larger than the synchronous speed of the second speed. And changes the throttle opening .theta. And the third brake pressure PB3 in association with each other so as to smoothly change. One or both of the throttle opening .theta. And the third brake pressure PB3 are appropriately changed. Control. Therefore, step 19 corresponds to the cooperative control means according to the second aspect of the present invention.

FIG. 5 shows an example in which the throttle opening is changed. The duty ratio of the linear solenoid valve SLU is increased stepwise to sweep up the third brake pressure PB3, and By decreasing the throttle opening θ, the increasing rate of the engine speed Ne is gradually reduced as shown by the solid line in FIG. 5 to smoothly change toward the second speed synchronous speed. As a result, it is possible to prevent torsion in the power transmission system and shock caused by the torsion. In this case, the change of the throttle opening θ
Not necessarily the sweep-up with simultaneous third brakes pressure PB3, may be appropriate at the time before and after. As described above, the rate of change of the third brake pressure PB3 may be changed (decreased) by changing the step width of the duty ratio in conjunction with the change of the throttle opening θ.

On the other hand, the control pattern III of the third brake pressure PB3 shown in FIG. 4 will be described. After the control of the initial hydraulic pressure, the third brake pressure PB3 is kept at a low pressure, and the throttle opening is increased. As a result, the duty ratio is increased stepwise at time t8 when the input rotational speed NC0 (engine rotational speed Ne) reaches a rotational speed lower than the synchronous rotational speed of the second speed by a predetermined rotational speed Δβ (> Δα). To increase the third brake pressure PB3. In this case, the step width of the increase in the duty ratio is set to be larger than that in the above-described power-on state, so that the rate of increase of the third brake pressure PB3 is larger than in the case of the downshift in the power-on state.

Therefore, in general, in the case of a constant speed shift with a throttle opening lower than that in the power-on state, the engagement pressure PB3 of the third brake B3, which is the frictional engagement device on the engagement side, is generally used.
The speed is swept up earlier than in the case of the power-on downshift, or the sweep-up rate is increased, so that the shift can proceed quickly and the engine speed can be smoothly adjusted toward the second speed synchronous speed. By changing the shift, the shift shock can be improved.

The constant speed shift is not limited to the downshift in the sports mode described above, but is performed by turning on the constant speed shift switch described above. Therefore, step 12 in FIG. May be replaced with a step of determining whether or not is turned on (step 12 ′).

In the above embodiment, the downshift from the third speed to the second speed has been described as an example. However, the present invention is not limited to the above embodiment, and the present invention is not limited to this. The present invention can also be applied to a device that performs downshift control. Therefore, the friction engagement device for which the engagement pressure is controlled may be a friction engagement device other than the third brake described above. Further, the present invention is characterized in that, as control of the engagement pressure of the friction engagement device involved in the shift, control contents specific to constant speed shift are provided. The control pattern is not limited to the control pattern shown in FIG. 3, and may be appropriately changed as needed. The present invention can be applied to an automatic transmission having a gear train or a hydraulic circuit different from the gear train or the hydraulic circuit shown in FIGS. 7 and 10 or a control device thereof. The driving force source in the present invention may be a motor other than the above-described engine.

[0058]

As described above, according to the first aspect of the present invention, the engagement pressure of the first frictional engagement device, which affects the change tendency of the input speed of the automatic transmission, is controlled by the driving force source. It would be controlled in accordance with the speed control in more detail
Down, which temporarily raises the rotational speed of the drive power source.
In the case of a shift, the engagement pressure of the friction engagement device on the engagement side is
First, the sweep-up control to raise
Or earlier than in the case of
Speed up shifting by increasing the sweep-up rate
And the speed of the drive power source
Can be crab changed, as a result, not only the torsional vibration of the drive power source in the shift end timing is reduced, it is possible to reduce the shock due to speed change.

According to the second aspect of the present invention, in the case of a downshift in which the rotational speed of the driving force source is increased, the first frictional engagement device that affects the change in the rotational speed of the driving force source is changed. a control and increase control of the rotational speed of the driving power source of the application pressure is correlated will be controlled, and more specifically, drive
A downshift where the power source speed is temporarily increased
The engagement pressure of the first frictional engagement device gradually increases
As a result, the rotational speed of the driving force source increases, and the driving force
Of the rotational speed of the driving force source by controlling the
The rate of increase is reduced, and these controls work in concert
Torsion in the power transmission system and
Shock can be prevented, as a result of its, it is possible to satisfactorily maintain the shift shock in comparison with the case of controlling the respective control with one another alone.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining control executed by a control device of the present invention.

FIG. 2 is a time chart showing a control pattern of a third brake pressure when downshifting from a third speed to a second speed in a power-on state.

FIG. 3 is a time chart showing a control pattern of a third brake pressure in a downshift from a third speed to a second speed in a power-off state.

FIG. 4 is a time chart showing a control pattern of a third brake pressure in a downshift from a third speed to a second speed in a constant speed shift.

FIG. 5 is a diagram for explaining an example of cooperative control between a throttle opening and a third brake pressure during a constant speed shift.

FIG. 6 is a diagram showing an overall control system according to the present invention.

FIG. 7 is a skeleton diagram showing an example of a gear train of the automatic transmission according to the present invention.

FIG. 8 is a diagram showing an engagement operation table of a friction engagement device for setting each shift speed in the automatic transmission.

FIG. 9 is a diagram showing an arrangement of each range position in the shift device.

FIG. 10 is a diagram illustrating a part of a hydraulic circuit that controls an engagement pressure when performing a shift between a second speed and a third speed.

[Explanation of symbols]

 Reference Signs List 1 engine 3 automatic transmission 21 electronic control unit for engine 33 electronic control unit for automatic transmission 38 hydraulic control unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-302669 (JP, A) JP-A-5-231525 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 61/00-61/24 F02D 29/00 B60K 41/00-41/10

Claims (2)

(57) [Claims] 1. A second first frictional automatic control of control enables the engagement pressure of the engagement device when a predetermined gear to release the frictional engagement device is engaged with the first frictional engagement device The transmission is
The control apparatus for a vehicle which is connected to driving power source for performing temporarily an elevated Ru controlling the rotational speed at a predetermined downshift in the automatic transmission, the predetermined shifting of the driving power source a transmission determining means for determining whether the rotational speed temporarily perform rises <br/> is allowed Ru controlled da Unshifuto or the control performed such have downshift, the engagement pressure of the first frictional engagement device gradually Boost pressure
The sweep control of control content, down-shift determined by the speed change decision means Ru increases the rotational speed of the driving force source braking
Varying in the case the case is da Unshifuto and downshift has a performed the control that performs control puff, performs the control Dow
Power-on / down without performing this control in case of shift
The engagement pressure is swept earlier than in the shift.
-Up to or control device for an automatic transmission, characterized by comprising a large to Rukakarigo control changing means the sweep-up rate. 2. A second first frictional automatic control of control enables the engagement pressure of the engagement device when a predetermined gear to release the frictional engagement device is engaged with the first frictional engagement device The transmission is
The control apparatus for a vehicle which is connected to driving power source for performing temporarily an elevated Ru controlling the rotational speed at a predetermined downshift in the automatic transmission, the predetermined shifting of the driving power source a transmission determining means for determining the rotational speed or temporarily perform rises <br/> is allowed Ru controlled da Unshifuto or the control performed such not downshift Daunshifu preparative driving force source that is determined by the speed-change determination means of
In the case of a downshift that performs control to increase the rotation speed
, The engagement pressure of the front Symbol first frictional engagement device gradually boosting of
Thereby pre Symbol driving force source in conjunction with sweep control the rotational speed of the
Control apparatus for an automatic transmission, characterized in that and a cooperative control unit that perform cooperative control of reducing the rate of increase.