JPH0960720A - Slip control device for vehicular direct-coupled clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately absorb shock developed as an engine revolution speed is decreased when deceleration slip control is restarted in the transition period where transfer is made from a deceleration slip control to an acceleration slip condition. SOLUTION: At the time of transition from a deceleration slip control to an acceleration slip control by means of a turbine revolution speed judging means 196, when a turbine revolution speed NT is judged as higher than a transient condition judging reference value KNSTL, slip control is considered to be different between a case where judgement made by the turbine revolution speed judging means 196 is affirmed, and a case where the aforesaid judgement is denied. For that reason, in response to a turbine revolution speed Nr , that is, the vehicle speed, slip control at the time of transition from a deceleration slip control to an acceleration slip control condition, is considered to be different, appropriate slip control can thereby be executed while the vehicle speed is taken into consideration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip control device for a direct coupling clutch for a vehicle.

[0002]

2. Description of the Related Art A hydraulic transmission with a direct coupling clutch having a direct coupling clutch for directly coupling a pump impeller and a turbine runner, for example, a vehicle equipped with a torque converter with a direct coupling clutch, a fluid coupling with a direct coupling clutch, etc. In order to further reduce the rotation loss of the direct coupling clutch in the vehicle and to improve the fuel efficiency of the vehicle, a slip region is provided between the release region and the engagement region of the direct coupling clutch, and the direct coupling clutch is half-engaged in the slip region. The actual slip amount, that is, the difference between the rotation speed of the pump impeller (that is, the engine rotation speed) and the rotation speed of the turbine runner (that is, the input shaft rotation speed of the automatic transmission), is set as the target slip amount that is set in advance. The acceleration slip control is executed so as to follow the. In addition, in a vehicle equipped with a fuel cut device that shuts off fuel to the engine in a region where the engine speed is higher than a preset fuel cut speed during deceleration, the engine speed is increased even during deceleration. In order to expand the fuel cut range,
The deceleration slip control is executed similarly to the above.

In the above slip control during deceleration, the deceleration running state of the vehicle is determined based on the fact that the throttle valve opening is fully closed by the idle switch, and is detected by, for example, a vehicle speed sensor. Is executed while the output shaft rotation speed is within a predetermined range, while the slip control during acceleration is a predetermined slip control that is determined from the relationship between the output shaft rotation speed and the throttle valve opening as shown in FIG. Executed while in the area. Therefore, when the throttle valve opening TA and the vehicle speed fall within the slip control range of FIG. 4 when shifting from the deceleration slip control state to the acceleration running state, the slip control is continuously performed. At this time, the engine rotation speed shifts from the state of being pulled up by the input shaft rotation speed to the state of being higher than the input shaft rotation speed, and a shock occurs due to the torque transmission direction of the hydraulic transmission being reversed. Therefore, for example, it is proposed to release the direct coupling clutch immediately after the transition to the accelerated traveling state is started.

However, when the direct coupling clutch is released at the start of the transition from the deceleration slip control state to the acceleration running state as described above, for example, as shown in the time chart of FIG. 10, when the throttle valve opening TA is relatively large. In addition, there is a problem that the engine rotation speed N _e becomes temporarily too high, which causes a feeling of strangeness. That is, in the figure, at time t ₀ , the engine rotation speed N _e is greater than the input shaft rotation speed N _T by a predetermined slip amount NSLP (= N _e −N
_(T ; for example, about -50 rpm.) The deceleration slip control state is gradually reduced while being maintained at a low rotation speed, and the throttle valve opening degree TA is increased to shift to the acceleration traveling state. Therefore, at this time t ₀ , the engine rotation speed N _e is increased, the drive duty ratio DSLU is set to 0%, and the direct coupling clutch is released.

Then, at time t ₁ , the slip amount N
When SLP exceeds a predetermined value (for example, about 70 rpm) and other acceleration slip start conditions are satisfied, the drive duty ratio DSLU is increased and the acceleration slip control is started. However, since the direct coupling clutch is released at time t ₀ as described above, a response delay occurs in the hydraulic control circuit and the mechanical system before the slip state is restored. Therefore, the engine rotation speed N _e becomes too high temporarily, which causes a feeling of strangeness.

[0006]

The above problem occurs when the throttle opening TA is relatively large. Therefore, when the throttle opening TA is relatively large, the transition to the acceleration running state is started. A slip control device has been proposed in which the slip control is continued and the slip control is stopped when the slip control is relatively small.
For example, this is the power plant control device described in Japanese Patent Laid-Open No. 1-224561. That is, when the throttle valve opening is relatively large, the shock resulting from the reversal of the torque transmission direction of the fluid type transmission device is smaller than the change in the engine output torque.
It is not necessary to release the direct coupling clutch for the purpose of alleviating the shock, and it is desirable to continue the slip state in order to suppress the increase of the engine rotation speed N _e . When the throttle valve opening TA is relatively small, the engine speed N _e does not increase so much even when the direct coupling clutch is released. Therefore, it is preferable to release the direct coupling clutch in order to reduce the shock. It will be.

However, as described above, when releasing the direct coupling clutch based on the small throttle valve opening TA at the time of transition from the deceleration slip control state to the acceleration traveling state, for example, as shown in FIG. Further, when the deceleration slip control is restarted in the transition period before the acceleration slip start condition is satisfied, the engine rotation speed N _e decreases until the direct coupling clutch actually enters the slip state, and then the engine rotation speed N _e is increased, which causes a shock. There is a problem that it can occur. That is, when the throttle valve opening degree TA is increased at time t _{0 and} the vehicle moves to the acceleration traveling state, if the throttle valve opening degree TA is relatively small as shown in the figure, the drive duty ratio DSLU becomes 0%. Then, the direct coupling clutch is released, and the engine rotation speed N _e is increased. Then, at time t ₁ , the engine speed N
_{If the} throttle valve is closed before _e is sufficiently increased and the acceleration slip start condition is satisfied, the deceleration slip control is restarted. However, as in the case of FIG. 10, there is a response delay until the slip state is actually reached. Since this occurs and the engine speed _Ne is temporarily reduced, an engagement shock occurs when the direct coupling clutch is engaged (slip state). This problem becomes more serious as the vehicle speed increases, because the engine rotation speed N _e decreases more greatly.

By the way, when the slip control is continued when the throttle valve opening TA is small at the time of shifting from the deceleration slip control state to the acceleration running state, if the vehicle is at a low vehicle speed, as shown in FIG. since the engine speed N _e is the engine easily exceed the input shaft rotational speed N _T shifts to driving state from the non-driving state, a shock is generated due to backlash and the engine torque changes in the drive system. Therefore, also from this point, it is preferable to release the direct coupling clutch at the time of transition from the deceleration slip control state to the acceleration traveling state at the low throttle valve opening degree TA as described above. However, when the vehicle on the opposite is high speed, as shown in FIG. 13, a small throttle valve opening TA the engine rotational speed N _e is difficult engine exceeds the input shaft rotational speed N _T in the non-driven state Since it is maintained, shock due to play in the drive system is unlikely to occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine when deceleration slip control is restarted during a transition period during which the deceleration slip control state shifts to an acceleration running state. This is to suitably alleviate a shock caused by a decrease in rotation speed.

[0010]

SUMMARY OF THE INVENTION In order to achieve such an object, the gist of the present invention is to provide a vehicle equipped with a direct coupling clutch that directly couples a pump impeller and a turbine runner to each other in a decelerated running state of the vehicle and A slip control device for a vehicle direct-coupling clutch of a type including a slip control means for controlling a slip amount of the direct-coupling clutch in an accelerated traveling state, wherein (a) a turbine rotation speed detecting means for detecting a rotation speed of the turbine runner, , (B) The rotation speed of the turbine runner detected by the turbine rotation speed detection means at the time of transition from the deceleration slip control state where the slip control of the direct clutch is performed by the slip control means in the deceleration traveling state to the acceleration traveling state. Turbine speed judgment means for judging that is higher than a predetermined transition state judgment reference value , (C) In the case where the determination by the turbine rotational speed determination means is affirmative and when the determination is negative, transitional slip control changing means that makes the slip control of the slip control means different is included. is there.

[0011]

In this way, the turbine rotation speed detecting means detects the turbine runner rotation speed,
The turbine rotation speed determination means determines that the turbine runner rotation speed is higher than a predetermined transition state determination reference value at the time of transition from the deceleration slip control state to the accelerated traveling state, and the transition slip control change means determines that The slip control performed by the slip control means is different when the determination is affirmative and when the determination is negative.

According to the above, the slip control at the time of transition from the deceleration slip control state to the acceleration running state differs depending on the turbine runner rotation speed, that is, the vehicle speed of the vehicle. Therefore, an appropriate slip is considered in consideration of the vehicle speed. It becomes possible to execute control.

[0013]

Further aspect of the invention, preferably, the transition slip control changing means continues the slip control of the slip control means when the determination by the turbine rotation speed determining means is affirmed, When the determination is denied, the slip control of the slip control means is stopped. With this configuration, when the turbine runner rotation speed is high, that is, when the vehicle speed is high, the slip control is continued at the time of shifting from the deceleration slip control state to the acceleration traveling state, and therefore, during the transition to the acceleration traveling state. Even when the deceleration slip control is restarted in the transition period, the engine rotation speed does not decrease as in the case where the direct coupling clutch is released, and the occurrence of shock and discomfort is suppressed.

Further, preferably, the slip control device further includes a gear shift stage judging means for judging a gear stage actually selected from a plurality of gear stages of the automatic transmission, and the turbine rotational speed judging means. Is for determining the turbine runner rotation speed based on the transition state determination reference value that is higher as the gear ratio of the actually selected speed is higher. By doing this, a gear stage with a large gear ratio,
Since the torque change at the time of shifting from the deceleration slip control state to the acceleration running state becomes large, the turbine runner rotation speed that makes the slip control different at that time is made higher by increasing the gear stage with a larger gear ratio. It becomes possible to execute the slip control in which the vehicle speed is appropriately considered.

Further, preferably, the slip control device determines that the actual slip amount (that is, the rotational speed difference) between the turbine runner and the pump impeller is larger than a predetermined slip start determination reference value. The transition-time slip control changing means is negative in the determination by the turbine rotation speed determining means and is negative in the determination by the slip amount determining means when transitioning from the deceleration slip control state to the acceleration traveling state. In this case, the slip control means stops the slip control. With this configuration, when shifting from the deceleration slip control state to the acceleration running state, the actual slip amount that was negatively controlled in the deceleration slip control state is large enough to require the acceleration slip control. The slip control is started when the value becomes.

[0016]

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

FIG. 1 is a skeleton view of an automatic transmission for a vehicle, the shift of which is controlled by a hydraulic control device according to an embodiment of the present invention. In the figure, an output of an engine 10 is input to an automatic transmission 14 via a torque converter 12 and transmitted to driving wheels via a differential gear device and an axle (not shown).

The torque converter 12 is the engine 1
Is connected to the crankshaft 16 of 0 and has a cross section U
A pump impeller 18 having a blade that is bent in a letter shape and that generates a flow of hydraulic oil having a directional component toward the engine 10 side, and is fixed to an input shaft 20 of the automatic transmission 14, and is attached to a blade of the pump impeller 18. A turbine runner 22 that has opposing blades and is rotated by receiving hydraulic oil from the pump impeller 18 and a piston 23 that is axially movable and relatively non-rotatably fitted to the hub shaft of the turbine runner 22. A lock-up clutch 24 that is connected to the input shaft 20 via the input shaft 20 and directly connects the pump impeller 18 and the turbine runner 22 to each other, and a stator 28 that is prevented from rotating in one direction by a one-way clutch 26. .

The automatic transmission 14 includes a first transmission 30 for switching between high and low gears and a second transmission 32 for switching between reverse gear and four forward gears. The first transmission 30 includes an HL planetary gear device 34 including a sun gear S0, a ring gear R0, and a planet gear P0 rotatably supported by the carrier K0 and meshed with the sun gear S0 and the ring gear R0, a sun gear S0, and a carrier. The clutch C0 and the one-way clutch F0 are provided between the sun gear S0 and the housing 41, and the brake B0 is provided between the sun gear S0 and the housing 41.

The second transmission 32 is a first planetary gear unit 36 comprising a sun gear S1, a ring gear R1, and a planet gear P1 rotatably supported by the carrier K1 and meshed with the sun gear S1 and the ring gear R1.
, Sun gear S2, ring gear R2, and carrier K
2 and a second planetary gear unit 38, which is rotatably supported by the sun gear S2 and a ring gear R2 and is meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3, and the carrier K3, which are rotatably supported by the sun gear S2. S3 and a third planetary gear set 40 including a planet gear P3 meshed with the ring gear R3.

The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2 and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 42. Further, a ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 44, and the sun gear S1 and the sun gear S3 are provided.
A clutch C2 is provided between the shaft 2 and the intermediate shaft 44. A band-type brake B1 for stopping rotation of the sun gear S1 and the sun gear S2 is provided on the housing 41.
It is provided in. A one-way clutch F1 is provided between the housing 41 and the sun gear S1 and the sun gear S2.
And the brake B2 are provided in series. The one-way clutch F1 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 20.

A brake B3 is provided between the carrier K1 and the housing 41, and the ring gear R3 is provided.
A brake B4 and a one-way clutch F2 are provided in parallel between and the housing 41. The one-way clutch F2 is configured to be engaged when the ring gear R3 tries to rotate in the reverse direction.

In the automatic transmission 14 configured as described above, for example, in accordance with the operation table shown in FIG. Five forward gears are switched. In FIG. 2, the ∘ mark indicates the engaged state, and the X mark indicates the non-engaged state. As is clear from FIG. 2, the brake B3 is engaged during a shift for switching from the first speed gear to the second speed and at the time of shifting for switching from the second speed to the third speed. The brake B2 is released from the second gear to the third gear.
It is engaged at the time of gear shifting to switch to the high gear stage. In the above FIG. 2, "1st", "2nd", "3"
"rd", "4th", and "5th" represent the forward first speed gear, the second speed gear, the third speed gear, the fourth speed gear, and the fifth speed gear, respectively. The gear ratio I gradually decreases from the first gear to the fifth gear. In addition, the torque converter 12 and the automatic transmission 14 described above.
Are symmetrical with respect to the axis, and therefore, in FIG. 1, the lower sides of the rotation axes of the input shaft 20, the output shaft 42, etc. are omitted.

As shown in FIG. 3, the intake pipe of the engine 10 of the vehicle has a first throttle valve 52 and a throttle actuator 54 operated by an accelerator pedal 50.
And a second throttle valve 56 operated by. Further, an engine rotation speed sensor 58 that detects the rotation speed of the engine 10, that is, the rotation speed of the pump impeller 18, an intake air amount sensor 60 that detects the intake air amount of the engine 10, and an intake air temperature sensor 62 that detects the temperature of the intake air. A throttle sensor 64 for detecting the opening TA of the first throttle valve 52, a vehicle speed sensor 66 for detecting the vehicle speed V from the rotational speed N _out of the output shaft 42, and a cooling water temperature sensor 68 for detecting the cooling water temperature of the engine 10. , A brake switch 70 for detecting the operation of the brake, an operation position sensor 74 for detecting the operation position of the shift lever 72, and the like are provided. From these sensors, the engine rotation speed N _e , the intake air amount Q, and the intake air temperature are provided. THa, opening TA of the first throttle valve, vehicle speed V, engine cooling water temperature TH
A signal representing w, the brake operation state BK, and the operation position Psh of the shift lever 72 is directly or indirectly supplied to the engine electronic control unit 76 and the shift electronic control unit 78, respectively. Further, a turbine rotation speed sensor 75 for detecting the rotation speed of the turbine runner 22.
A signal representing the turbine rotation speed N _T is supplied from (that is, turbine rotation speed detection means) to the electronic shift control device 78. The engine electronic control unit 76 and the shift electronic control unit 78 are interconnected via a communication interface, and input signals and the like are supplied to each other as necessary.

The engine electronic control unit 76 includes a CPU,
A so-called microcomputer having a RAM, a ROM, and an input / output interface, the CPU processes an input signal according to a program stored in the ROM in advance while utilizing a temporary storage function of the RAM, and executes various engine controls. For example, in the fuel injection amount control, the fuel injection valve 80 is controlled to optimize the combustion state, in the ignition timing control the igniter 82 is controlled to optimize the retard amount, and not shown for idle speed control. By controlling the bypass valve, in the traction control, in order to prevent slipping of the driving wheels and to secure an effective driving force and vehicle stability, the throttle actuator 54 keeps the second valve in a fully open state.
In the coasting mode in which the throttle valve 56 is controlled and the idle cut of the throttle sensor 64 detects that the first throttle valve 52 is closed in the fuel cut control, the engine speed N _e is preset to the fuel cut. By closing the fuel injection valve 80 only for a period exceeding the rotation speed N _CUT , the fuel supplied to the engine 10 is shut off and the fuel efficiency is improved.

The electronic shift control device 78 is also a microcomputer similar to that described above, and the CPU uses the temporary storage function of the RAM while processing the input signal in accordance with the program previously stored in the ROM 79, and the hydraulic control circuit 84. Each solenoid valve or linear solenoid valve is driven. For example, the electronic shift control device 78 includes the first throttle valve 52.
The linear solenoid valve _SLT to generate an output pressure P _SLT having a magnitude corresponding to the opening degree TA, the linear solenoid valve SLN to control the accumulator back pressure, and the lockup clutch 24 to engage or slip. Quantity NSLP
The linear solenoid valve SLU is driven to control each. Further, the electronic shift control device 78 determines the gear stage of the automatic transmission 14 based on the actual throttle valve opening TA and the vehicle speed V from the pre-stored shift map, and from the relationship shown in FIG. Lockup clutch 24
Is determined, the solenoid valves S1, S2, S3 are driven so that the determined gear stage and engagement state are obtained, and the solenoid valve S4 is not driven when engine braking is generated. .

The electronic shift control device 78 further executes engagement control and slip control of the lockup clutch 24, and releases the lockup clutch 24 at the first gear stage and the second gear stage of the automatic transmission 14. However, at the third and fourth gears, the throttle valve opening TA,
Based on the vehicle speed (transmission output shaft rotation speed) V, a region of release, slip, or engagement is determined, and if it is a release or engagement region, the lockup clutch 24 is released or engaged. In the slip region, the electronic shift control device 78 executes slip control of the lockup clutch 24. In this slip control, in order to improve the fuel efficiency as much as possible without impairing the drivability, the rotational fluctuation of the engine 10 is absorbed and coupled to suppress the rotational loss of the torque converter 12 as much as possible. The lockup clutch 24 is maintained in the slip state. Further, the slip control of the lockup clutch is executed for the purpose of expanding the control range of the fuel cut control even during deceleration coasting of the vehicle. In this case, since the throttle valve opening TA is zero, the vehicle speed V is used exclusively to determine in which region.

In the above slip control, the actual slip amount NSL is executed according to a slip control routine (not shown).
P (= N _e −N _T ) is calculated, and the drive current I _SLU of the linear solenoid valve SLU, that is, the drive current I _SLU of the linear solenoid valve SLU is calculated according to the following equation (1) so that the preset target slip amount TNSLP matches the actual slip amount NSLP. Drive duty ratio DS
LU (%) is calculated, and the control pressure P _SLU output from the linear solenoid valve _SLU is adjusted. DSLU = DFWD + DFB (1)

In the above equation (1), DFWD is, for example,
Feedforward as a function of engine 10 output torque
DFB is, for example, the target slip
Deviation ΔE between the amount TNSLP and the actual slip amount NSLP
Feed for solving (= NSLP-TNSLP)
This is the back control output value. These DFWD and DFB are
Amount converted to duty ratio, whose unit is%
You. The feedback control output value DFB is well known.
It is calculated from the PID control formula (equation (2) below)
is there. In equation (2), K_PIs the proportional gain, T₁
Is the integration time, T _DIs the derivative time.

[0030]

[Equation 1]

FIG. 5 shows a main part of the hydraulic control circuit 84. In the figure, a linear solenoid valve SLU that functions as a control pressure generation valve is a pressure reducing valve that uses the modulator pressure P _M as a source pressure, and as shown in FIG. 6, a drive duty ratio output from the electronic shift control device 78. The control pressure P _SLU that increases with the drive current I _{SLU of the} DSLU is output and supplied to the lockup relay valve 98 and the lockup control valve 100.

The lock-up relay valve 98 is capable of abutting against each other and has a spring 102 interposed between the first spool valve element 104 and the second spool valve element 1.
06 and the first spool valve element 104 and the second spool valve element 1 provided on the shaft end side of the first spool valve element 104.
Control pressure P in order to urge No. 06 to the engagement (ON) side position.
Oil chamber 108 for receiving _SLU and first spool valve 10
And an oil chamber 110 for receiving the second line pressure P _L2 for urging the fourth and second spool valve elements 106 to the release side position.

The first spool valve 104 is released (OF
When located in the F) side position, the second line pressure P _L2 supplied to the input port 112 is supplied from the release side port 114 to the release side oil chamber 116 of the torque converter 12, and at the same time, the engagement side of the torque converter 12 is reached. The hydraulic oil in the oil chamber 118 is discharged from the engagement side port 120 through the discharge port 122 to the cooler bypass valve 124 or the oil cooler 126, and the engagement pressure of the lockup clutch 24, that is, the differential pressure (= the engagement side oil). Hydraulic pressure in chamber 118-release side oil chamber 11
The hydraulic pressure in 6) is lowered. On the contrary, when the first spool valve element 104 is located at the engagement side position, the input port 11
The second line pressure P _L2 supplied to 2 is applied to the engagement side port 120.
Is supplied to the engagement side oil chamber 118 of the torque converter 12, and at the same time, the release side oil chamber 11 of the torque converter 12 is supplied.
The hydraulic oil in 6 is discharged from the release side port 114 to the discharge port 12
8. Control port 1 of lockup control valve 100
The lockup clutch 24 is discharged through the discharge port 132 and the discharge port 132 so that the engagement pressure of the lockup clutch 24 is increased.

Therefore, the control pressure P _SLU is equal to the predetermined value β.
In the following cases, the first spool valve element 104 is positioned at the release side (OFF) position shown on the right side of the center line in FIG. 5 according to the thrust _force based on the spring 102 and the second line pressure P _L2 , and the lock-up clutch 24 Is released, but
When the control pressure P _SLU exceeds a predetermined value α higher than the predetermined value β, the first spool valve element 104 follows the thrust based on the control pressure P _SLU and engages with the engagement side (O
N) and the lockup clutch 24 is engaged or slipped. First spool valve 1
04, the pressure receiving area of the second spool valve element 106, and the biasing force of the spring 102 are set in this manner. In this way, the engagement or slip state of the lockup clutch 24 when the lockup relay valve 98 is switched to the engagement side is controlled by the lockup control valve 100 that operates according to the magnitude of the control pressure P _SLU .

The lockup control valve 100 controls the actual slip amount NSLP of the lockup clutch 24 in accordance with the control pressure P _SLU when the lockup relay valve 98 is in the engagement side position, or the lockup clutch 2
4 for engaging the spool valve 13
4, a plunger 136 that abuts on the spool valve element 134 and applies thrust to the discharge side position shown on the right side of the center line in FIG. 5, and a supply side shown on the left side of the center line in FIG. A spring 138 that applies thrust toward the position and a hydraulic pressure P _ON within the engagement-side oil chamber 118 of the torque converter 12 that receives the spring 138 and biases the spool valve element 134 toward the supply-side position. The oil chamber 140 is provided on the shaft end side of the plunger 136, and the release side oil chamber 116 of the torque converter 12 is arranged to urge the spool valve element 134 toward the discharge side position.
An oil chamber 142 for receiving the internal hydraulic pressure P _OFF and an oil chamber 144 provided in the middle of the plunger 136 for receiving the control pressure P _SLU are provided.

Therefore, when the spool valve element 134 is positioned at the discharge side position, the control port 130 and the discharge port 132 are made to communicate with each other, so that the engagement pressure is increased and the lockup clutch 24 is engaged. The combined torque is increased, but on the contrary, when it is located in the supply side position,
Since the supply port 146 to which the first line pressure P _L1 is supplied and the control port 130 are made to communicate with each other, the first line pressure P _L1 is supplied to the release side oil chamber 116 of the torque converter 12 to reduce the engagement pressure. Lowered lockup clutch 2
The engagement torque of No. 4 is reduced.

When the lockup clutch 24 is released
Control pressure P_SLUIs smaller than the predetermined value β
The linear solenoid valve SLU is
It is driven by the unit 78. On the contrary, lock-up crack
When engaging the switch 24, the control pressure P_SLUIs the maximum value
The linear solenoid valve SLU is
The lock-up clutch 24 is driven by the motor 78.
When the lip is applied, the control pressure P_SLUIs the predetermined value
Linear solenoid valve SLU so that it is between β and the maximum value
Are driven by the electronic shift control device 78. Sand
The lockup control valve 100 shown in FIG.
In the engagement side oil chamber 118 of the torque converter 12,
Oil pressure P_onAnd the hydraulic pressure P in the release side oil chamber 116_offAnd control
Pressure P_SLUEngaging pressure, that is,
Those hydraulic pressure P_onAnd P_offDifferential pressure (P_on−P_off)
Control the engagement torque of the corresponding lockup clutch 24
Pressure P _SLUThe slip amount NSLP is changed according to
It is controlled.

In FIG. 7, the broken line on the upper side indicates the hydraulic pressure of the lock-up relay valve 98 which is required to move from the on-side position where the lock-up clutch 24 is engaged or slipped to the off-side position where it is released. The characteristic is shown, and the broken line located on the lower side shows the hydraulic characteristic of the lock-up relay valve 98 required to change from the off-side position to the on-side position. The slopes of these broken lines are the first spool valve element 104 and the second spool valve element 106 for operating the lockup relay valve 98.
It is determined according to the size of the area of the pressure receiving portion, the supplied hydraulic pressure, and the characteristics of the spring 102.

The solenoid relay valve 170 is the output port 1 connected to the oil chamber 108 of the lockup relay valve 98.
72, drain port 174, linear solenoid valve SL
Input port 176 to which control pressure P _SLU from U is supplied
And a spool valve 178 that is switched between a lock-up release position that allows the output port 172 to communicate with the drain port 174 and a lock-up permission position that allows the output port 172 to communicate with the input port 176, and this spool valve 17
180 for urging the valve 8 toward the lock-up permission position, and a gear stage for accommodating the spring 180 and for biasing the spool valve element 178 toward the lock-up permission position. The oil chamber 182 that receives the engagement pressure P _{B2 of the} brake B2 generated in the above-described manner through the orifice 181 and the oil that receives the first line hydraulic pressure P _L1 for urging the spool valve element 178 toward the lockup release position. And chamber 184.
As a result, the lock-up relay valve 98 can be supplied with the control pressure P _SLU to the oil chamber 108 only in the third and higher gear stages, and the lock-up relay valve 98 is engaged (ON) according to the control pressure P _SLU . It can be switched to a position. Since the second line pressure P _L2 is one pressure regulated by pressure reduction the first line pressure P _L1, the first line pressure P _L1 is at a higher pressure than the second line pressure P _L2 at all times.

An oil passage 186 is provided between the linear solenoid valve SLU and the oil chamber 144 of the lockup control valve 100, and the control pressure P _SLU output from the linear solenoid valve _SLU is the solenoid relay valve. 1
The oil is supplied directly to the oil chamber 144 of the lock-up control valve 100 without passing through 70. This oil passage 186 is provided to operate the lockup control valve 100 by the control pressure P _SLU even at the second speed and lower gears so as to detect an abnormality in which the lockup relay valve 98 is located on the engagement side. There is.

FIG. 8 is a functional block diagram for explaining the main part of the control function in the slip control of the electronic shift control device 78. In the figure, a lock-up relay valve 98 that is switched between an off-side position for releasing the lock-up clutch 24 and an on-side position for engaging the lock-up clutch 24, and adjusting the discharge amount of hydraulic oil discharged through the lock-up relay valve 98. A lockup control valve 100 that controls the slip amount of the lockup clutch 24 by
As it increases, the lockup relay valve 98 is switched to the ON position, and it functions as a control pressure generation valve that generates the control pressure P _SLU for controlling the operation of the lockup control valve 100 so that the slip amount decreases. By controlling the linear solenoid valve SLU and the linear solenoid valve SLU on the basis of the drive duty ratio DSLU calculated by the control equation (1) according to a control routine (not shown), the actual slip amount NSLP becomes equal to the target slip amount TLU.
Slip control means 188 for performing slip control so as to match NSLP is provided.

Further, the turbine rotation speed judging means 196
Indicates that the turbine rotation speed N _T detected by the turbine rotation speed sensor 75 is a predetermined transition state determination reference value when the transition from the state in which the deceleration slip control is being executed to the acceleration traveling state is being performed. Judge that it is larger than KNTSL. Transition slip control changing means 19
0 changes the slip control by the slip control means 188 when the determination by the turbine rotation speed determination means 196 is affirmative and when the determination is negative, that is, when the turbine rotation speed N _T is high and low. .
That is, at the time of the above transition, for example, when the turbine rotation speed N _T is high and the vehicle is traveling at a high vehicle speed, the slip control is continuously executed, and conversely, the turbine rotation speed N _T is low and the vehicle is low. When traveling at the vehicle speed, the slip control is stopped.

Further, the shift speed determination means 192 determines the shift speed actually selected from the combination of the operations of the solenoid valves S1, S2 and S3, and the gear ratio of the selected shift speed is large. Transition state determination reference value KNTS
By setting L to a high value, the turbine speed N _T for changing the slip control is changed by the slip control changing means 190 during transition. Further, the slip amount determination means 1
94 determines that the actual slip amount NSLP is larger than a predetermined slip start determination reference value KNSLPS, and causes the transition slip control changing unit 190 to change the slip control depending on whether it is large or small. That is, the transition slip control changing unit 190 suspends the slip control when, for example, the determination by the turbine rotation speed determination unit 196 is denied and the determination by the slip amount determination unit 194 is denied.

FIG. 9 is a flow chart showing the main part of the slip control operation of the electronic shift control device 78 when shifting from the deceleration slip control state to the acceleration traveling state.

In the figure, in step S1, it is determined whether or not deceleration slip control is being executed. Since this determination is affirmative during deceleration slip control, the routine proceeds to step S2, where the content of the flag F1 is set to "1", and this routine is ended. This flag F1 is
When the content is "1", it indicates that the deceleration slip was executed in the previous control cycle. On the other hand, if the deceleration slip is not executed, the process proceeds to step S3 and the content of the flag F1 is "1".
Is determined. When the throttle valve opening TA is increased by depressing the accelerator pedal 50 or the like from the state where the deceleration slip control was being executed until immediately before, and the deceleration slip control is ended, in step S2 described above. Since the content of the flag F1 is set to "1", the determination at this step is affirmative and the process proceeds to step S4.

In step S4 corresponding to the turbine rotation speed determination means 196, the turbine rotation speed (input shaft rotation speed) _NT is a predetermined transition state determination reference value KNTSL.
Is greater than the above, that is, whether the vehicle speed V is relatively high. This transition state determination reference value KNTSL
As shown in FIG. 11, when the acceleration travel is started from the deceleration slip control state, the engine speed N _e decreases when the deceleration slip control is restarted before the acceleration slip control is started. Is an upper limit (threshold value) of the turbine rotation speed for keeping the shock generated at that time to an acceptably small value, for example,
The value is about 1350r.pm. If N _T ≧ KNTSL, that is, if the vehicle is traveling at a high vehicle speed, this determination is affirmative, so the routine proceeds to step S5, where it is determined whether the acceleration slip start condition is satisfied. The acceleration slip start condition is determined based on, for example, that the idle switch is off and that the slip control region is in the slip control region shown in FIG. If this decision is positive,
The process proceeds to step S6 corresponding to the transition slip control changing means 190 to execute the acceleration slip control,
At 7, the contents of the flag F1 are reset to "0" and this routine is ended.

On the other hand, when the turbine rotation speed N _T is smaller than the transition state determination reference value KNTSL when the deceleration slip control is being executed and the state is accelerating, that is, when the vehicle is traveling at a low vehicle speed. Since the determination in step S4 is negative, the process proceeds to step S8 corresponding to the slip amount determination means 194, and it is determined whether or not the actual slip amount NSLP is larger than the slip start determination reference value KNSLPS. This slip start determination reference value KNSLPS is the actual slip amount NSLP (= N _e − when the deceleration slip control state is changed to the acceleration traveling state).
N _T ) is a value for determining whether it is large enough to require acceleration slip control, and is, for example, a value of about 70 rpm. At the beginning of the transition from the deceleration slip control to the acceleration running state, the actual slip amount NSLP is a negative value or a small positive value, so this determination is denied and step S9
Then, the slip control is terminated, and the step S
At 7, the contents of the flag F1 are reset to "0" and this routine is ended. In the present embodiment, this step S9 also includes the transition slip control changing means 1
Corresponds to 90.

After steps S3 to S7 have been executed once, unless the deceleration slip control is restarted, the determination of step S3 is always denied, so that the process immediately proceeds to step S8 without executing step S4 and each step is executed. To be done. Then, when the actual slip amount NSLP becomes sufficiently large and the determination in step S8 is affirmed while the above steps are repeatedly executed, the process proceeds to step S10, and another acceleration slip control similar to that in step S5 is performed. It is determined whether the start condition is satisfied. If the determination is negative, the process proceeds to step S9 to stop the slip control, but if the determination is affirmative, the process proceeds to step S6 to execute the acceleration slip control, and the present routine is ended.

When the determination in step S1 is initially denied, it means that the deceleration slip control is not shifted to the acceleration running state, so the determination in step S3 is denied from the beginning and the process proceeds to step S8 and step S4. Each step is executed similarly to the control cycle after the determination of No is denied. When the transition from the deceleration slip to the acceleration traveling state is not performed, the engine speed cannot be reduced as in the case where the transition to the acceleration traveling state as shown in FIG. 11 is interrupted, so the vehicle speed is taken into consideration. There is no need to do it. In this case, it is determined whether or not the acceleration slip control is performed based on the normal acceleration slip start condition, that is, whether the actual slip amount NSLP or the slip control region in FIG. 4 is present.

As described above, according to the present embodiment, the turbine rotation speed N _T is detected by the turbine rotation speed sensor 75 corresponding to the turbine rotation speed detection means, and the step S4 corresponding to the turbine rotation speed determination means 196 detects the turbine rotation speed N _T. It is determined that the turbine rotation speed N _T is higher than the predetermined transition state determination reference value KNTSL at the time of transition from the deceleration slip control state to the acceleration traveling state, and step S6 or step corresponding to the transition slip control changing means 190 is performed. By S9, the slip control is different depending on whether the determination by the turbine rotation speed determination means 196 is affirmative or not.

As described above, the slip control at the time of transition from the deceleration slip control state to the acceleration traveling state is different depending on the turbine rotation speed N _T, that is, the vehicle speed V of the vehicle. It becomes possible to execute appropriate slip control.

Further, according to the present embodiment, the transition slip control changing means 190 continues the slip control of the slip control means 188 when the determination by the turbine rotation speed determining means 196 is affirmed. When the determination is negative, the slip control of the slip control means 188 is stopped. Therefore, when the turbine rotation speed N _T is high, that is, when the vehicle speed is high, the slip control is continued during the transition from the deceleration slip control state to the acceleration traveling state, and therefore during the transition period during the transition to the acceleration traveling state. Even when the deceleration slip control is restarted, the engine speed N _e does not decrease due to the disengagement of the direct coupling clutch, and the occurrence of shock and discomfort is suppressed.

Further, according to this embodiment, the actual slip amount N
The transitional slip control changing means 190 further includes step S8 corresponding to the slip amount judging means 194 for judging that the SLP is larger than a predetermined slip start judging reference value KNSLPS, and the shift slip control changing means 190 changes from the deceleration slip control state to the acceleration traveling state. When the determination by the turbine rotation speed determination means 196 is denied and the determination by the slip amount determination means 194 is denied at the time of shift of No. 1, the slip control means 188 suspends the slip control. Therefore, when shifting from the deceleration slip control state to the acceleration running state, the actual slip amount NSLP that was negatively controlled in the deceleration slip control state becomes a positive value large enough to require the acceleration slip control. The slip control will be started when this happens.

Further, according to the present embodiment, when the turbine rotation speed N _T is smaller than the transition state determination reference value KNTSL, the slip control is stopped in step S9, so that the low throttle as shown in FIG. The occurrence of shock or discomfort due to the end of the fuel cut control when the valve opening is low and the vehicle speed is low is appropriately mitigated.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in other forms.

For example, the control pressure P _SLU in the above embodiment is
As the lock-up relay valve 98 is switched to the ON side as it increases from zero, the differential pressure (P _on -P _off ) of the lock-up clutch 24 is increased thereafter, and the lock-up clutch 24 is finally engaged. But on the contrary,
Lock-up relay valve 98 as the maximum value decreases
Is switched to the on side, and thereafter, the differential pressure (P _on -P _off ) of the lockup clutch 24 is increased, and finally the lockup clutch 24 is engaged.
The lockup relay valve 98, the lockup control valve 100, and the like may be configured.

Further, according to the above-described embodiment, the turbine rotational speed N _T is compared with the constant transition state determination reference value KNTSL in step S4 corresponding to the turbine rotational speed determination means 196. The determination reference value KNTSL may be appropriately changed according to the actually selected shift speed. That is, it may be changed to a larger value as the gear ratio of the shift speed increases. In this way, when a gear with a large gear ratio is selected, the shock resulting from the end of fuel cut control is more reliably alleviated, and a gear with a small gear ratio is selected. Can more surely alleviate the occurrence of a shock due to a decrease in the engine rotation speed N _e due to the restart of the deceleration slip during the transition to the acceleration traveling state.

Further, in the embodiment, it is determined whether the slip control is continued at the time of shifting to the acceleration traveling state, that is, whether the acceleration slip control is continuously started from the deceleration slip control. _Although the determination is made based only on _T, that is, the vehicle speed V, it may be determined based on, for example, the throttle valve opening TA. That is, the slip control may be stopped only when the vehicle speed is low and the throttle valve opening is low, and in other cases, the slip control may be continued. Thus, it is possible to suitably relax the generation of the uncomfortable feeling caused by the engine rotational speed N _e is too high in the case of low speed and high throttle valve opening.

The values of the transition state determination reference value KNTSL and the slip start condition determination reference value KNSLPS are appropriately changed according to the engine output characteristics and the like.

Further, in the embodiment, when the turbine rotation speed N _T is smaller than the transition state determination reference value KNTSL, the slip control is stopped. However, for example, the slip control should be stopped. Instead of this, the slip control means 188 may be controlled so that the target slip amount TNSLP becomes large. This is because if the target slip amount is increased, the torque transmitted by the torque converter 12 is decreased and the shock at the end of the fuel cut control is alleviated. In that case, for example, the target slip amount may be adjusted continuously or stepwise according to the turbine rotation speed N _T.

Further, in the embodiment, the turbine rotation speed detecting means for detecting the rotation speed of the turbine runner 22 is constituted by the turbine rotation speed sensor 75,
The turbine rotation speed _NT directly detected by the turbine rotation speed determination means 196 and the transition state determination reference value KN
Although it was compared with TSL, for example, the vehicle speed sensor 66
The turbine rotation speed determination means 196 may make the determination based on the output shaft rotation speed N _out detected by the vehicle speed V. However, in this case, the value obtained by multiplying the output shaft rotation speed N _out by the gear ratio I of the actually selected gear is compared with the transition state determination reference value KNTSL, or the output shaft rotation speed N it is necessary to compare actual and different transition state determination reference value corresponding to the gear ratio of the selected gear stage and _out.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a skeleton diagram illustrating a configuration of an automatic transmission for a vehicle in which a gear stage is controlled by a hydraulic control device according to an embodiment of the present invention.

FIG. 2 is a table showing a relationship between a combination of operations of a plurality of frictional engagement devices and a gear established by the combination in the automatic transmission of FIG. 1;

FIG. 3 is a block diagram including a hydraulic control circuit and an electric control circuit for controlling the automatic transmission of FIG. 1;

FIG. 4 is a diagram used for region determination in slip control.

5 is a diagram illustrating a main part of the hydraulic control circuit of FIG.

FIG. 6 is a diagram for explaining output characteristics of a solenoid valve SLU.

7 is a characteristic diagram showing the relationship between the control pressure P _SLU and the engagement side oil pressure P _on and the disengagement oil pressure P _off of the lock-up clutch in the hydraulic control circuit of FIG.

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

9 is a flowchart illustrating a main part of a slip control operation of the electronic shift control device of FIG.

FIG. 10 is a diagram for explaining a problem in the conventional slip control in which the slip control is stopped when shifting from the deceleration slip control state to the acceleration traveling state.

FIG. 11 is a diagram for explaining a problem when the deceleration slip control is restarted during the transition when the slip control is stopped at the time of shifting from the deceleration slip control state to the acceleration traveling state.

FIG. 12 is a diagram for explaining a problem in the case of low vehicle speed and low throttle valve opening when slip control is continued when shifting from the deceleration slip control state to the acceleration traveling state.

FIG. 13 is a diagram for explaining changes in the engine speed and the like when the vehicle speed is high and the throttle valve opening is low when the slip control is continued when shifting from the deceleration slip control state to the acceleration traveling state.

[Explanation of symbols]

10: Engine 14: Automatic transmission 24: Lock-up clutch (direct coupling clutch) 75: Turbine rotation speed sensor (turbine rotation speed detection means) 188: Slip control means 190: Transition slip control change means 194: Slip amount determination means 196 : Turbine rotation speed judgment means

Claims (2)

[Claims] 1. A vehicle having a direct coupling clutch for directly coupling a pump impeller and a turbine runner, the vehicle having a slip control means for controlling a slip amount of the direct coupling clutch in a decelerated traveling state and an accelerated traveling state of the vehicle. A direct-connection clutch slip control device for turbine rotation speed detection means for detecting the rotation speed of the turbine runner, and a deceleration slip control state in which slip control of the direct-connection clutch is performed by the slip control means in a deceleration running state. A turbine rotation speed determination means for determining that the rotation speed of the turbine runner detected by the turbine rotation speed detection means is higher than a predetermined transition state determination reference value at the time of transition to the running state; and the turbine rotation speed determination When the judgment by means is affirmed and when it is denied The slip control device for a direct clutch for vehicle, further comprising: a transition slip control changing unit that makes the slip control of the slip control unit different. 2. The transition slip control changing means continues the slip control of the slip control means when the determination by the turbine rotation speed determining means is affirmative, and when the determination is negative. The control device for a direct clutch for vehicle according to claim 1, wherein the slip control of the slip control means is stopped.