JP2864958B2 - Slip control device for vehicle direct coupling clutch - Google Patents

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 vehicle direct coupling clutch.

[0002]

2. Description of the Related Art In a vehicle equipped with a fluid transmission with a direct coupling clutch such as a torque converter with a lock-up clutch or a fluid coupling with a lock-up clutch, the rotational loss of the direct coupling clutch is further reduced to reduce the fuel consumption of the vehicle. For the purpose of improvement, a slip region is provided between the release region and the engagement region of the direct coupling clutch, and in the slip region, the slip amount is controlled so as to bring the direct coupling clutch into a semi-engaged state, while the direct coupling clutch is controlled. A slip control device has been proposed which inhibits slip control when a slip friction abnormality, that is, a pulsation of a rotational speed difference due to discontinuous friction engagement called judder is detected. For example, a slip control device described in Japanese Patent Publication No. Sho 62-50703 is the slip control device. According to this, when a judder occurs, it is difficult to detect the actual slip amount due to the temporary engagement of the direct coupling clutch, and the feedback control for matching the target slip amount with the actual slip amount becomes unstable, so that the drivability is reduced. The inconvenience of being damaged is eliminated.

[0003]

In the above-described conventional slip control device, the slip control is inhibited only when an abnormality occurs in the direct-coupled clutch, thereby preventing a decrease in drivability. When the vehicle is running, rotation fluctuations may be transmitted from the drive wheels to the directly-coupled clutch due to traveling on rough roads with severe irregularities, traction control, anti-skid control, etc. There have been inconveniences that it is difficult to detect the actual slip amount of the clutch, and the feedback control for matching the target slip amount with the actual slip amount becomes unstable, resulting in impaired drivability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an unstable operation of slip control due to rotation fluctuation transmitted from a driving wheel to a direct coupling clutch. It is an object of the present invention to provide a vehicle direct-coupled clutch slip control device that eliminates a decrease in drivability due to the vehicle.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a vehicle having a fluid transmission with a direct coupling clutch in a power transmission path from an engine to driving wheels. A slip control device for a vehicle direct-coupled clutch of a type including slip control means for slipping the direct-coupled clutch when the traveling state of the vehicle enters a predetermined slip region, wherein (a) the direct-coupled clutch from the drive wheel (B) when the occurrence of rotation fluctuation transmitted from the drive wheel toward the direct coupling clutch is determined by the rotation fluctuation determination means. Includes slip control inhibiting means for inhibiting slip control by the slip control means.

[0006]

In this way, when the rotation fluctuation judging means judges that the rotation fluctuation transmitted from the drive wheel toward the direct coupling clutch has occurred, the slip control prohibiting means causes the slip control by the slip control means. Control is prohibited.

[0007]

Therefore, traveling on a rough road with severe unevenness,
By traction control, anti-skid control, etc.
In a traveling state in which the rotation fluctuation is transmitted from the drive wheels to the direct coupling clutch, the slip control by the slip control means is inhibited by the slip control inhibiting means, so that it is difficult to detect the actual slip amount of the direct coupling clutch, The inconvenience that feedback control for making the target slip amount coincide with the actual slip amount becomes unstable and the drivability is impaired is eliminated.

[0008]

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

FIG. 1 is a skeleton view of a vehicle power transmission device to which an embodiment of the present invention is applied. In the figure, the power of an engine 10 is transmitted to a differential gear device 15 and drive wheels 17 to be described later through a torque converter 12 with a lock-up clutch, a stepped automatic transmission 14 including three sets of planetary gear units, and the like. It is supposed to be.

[0010] The torque converter 12 is an engine 1
Pump wheel 18 connected to crankshaft 16
And a turbine wheel 22 fixed to the input shaft 20 of the automatic transmission 14 and rotated by receiving oil from the pump wheel 18, and fixed to a housing 26 which is a non-rotating member via a one-way clutch 24. Stator wheel 28
And a lock-up clutch 32 connected to the input shaft 20 via a damper 30. When the oil pressure in the release-side oil chamber 33 is higher than that in the engagement-side oil chamber 35 in the torque converter 12, the lock-up clutch 32 is disengaged. Torque is transmitted at a corresponding amplification factor. However, when the oil pressure in the engagement-side oil chamber 35 is higher than that in the release-side oil chamber 33, the lock-up clutch 32 is engaged, so that the input / output members of the torque converter 12, that is, the crankshaft 16 and the input The shaft 20 is directly connected.

The automatic transmission 14 is provided with a three-axis
Sets of single pinion type planetary gear sets 34, 36, 38
The input shaft 20, the output gear 39 rotating together with the ring gear of the planetary gear set 38, and the differential gear set 15
And a counter shaft (output shaft) 40 that transmits power between the counter shaft and the output shaft. Some of the components of the planetary gear units 34, 36, 38 are not only integrally connected to each other, but also
The clutches are selectively connected to each other by three clutches C ₀ , C ₁ and C ₂ . The planetary gear units 34, 3
Some of the components of the 6,38 are composed of four brakes B ₀ , B
₁ , B ₂ , B ₃ are selectively connected to the housing 26 and, in addition, some of the components are mutually connected by three one-way clutches F ₀ , F ₁ , F ₂ depending on their direction of rotation or the housing 26. To be engaged.

The clutches C ₀ , C ₁ , C ₂ and the brakes B ₀ , B ₁ , B ₂ , B ₃ include, for example, a multi-plate clutch or one band or two bands whose winding directions are opposite to each other. It is constituted by band brakes and the like, and each of them is operated by a hydraulic actuator. The operation of each of the hydraulic actuators is controlled by an electronic control unit 42 described later, and is shown in FIG. As described above, four forward speeds and one reverse speed with different speed ratios I (= rotation speed of input shaft 20 / rotation speed of counter shaft 40) are obtained. In FIG. 2, "1st",
“2nd”, “3rd”, and “O / D (overdrive)” represent the first gear, second gear, third gear, and fourth gear on the forward side, respectively. The gear ratio gradually decreases from the first gear to the fourth gear. In addition, since the torque converter 12 and the automatic transmission 14 are configured symmetrically with respect to the axis, the lower side of the rotation axis of the input shaft 20 and the upper side of the rotation axis of the counter shaft 40 are omitted in FIG. Is shown.

The hydraulic control circuit 44 includes a shift control hydraulic control circuit for controlling the gear position of the automatic transmission 14 and a lock-up clutch control for controlling the engagement of the lock-up clutch 32. And a hydraulic control circuit. As is well known, the shift control hydraulic control circuit includes a first solenoid valve 46 and a second solenoid valve 48 that are turned on and off by solenoids No. 1 and No. 2, respectively. As shown in FIG. 2, a clutch and a brake are selectively operated by a combination of the operations of the valve 46 and the second solenoid valve 48 to establish any one of the first to fourth gears. It is supposed to be.

The lock-up clutch control hydraulic control circuit is turned on and off by a switching electromagnetic solenoid 49 to generate a switching signal pressure P _sw, as shown in FIG. 3, for example. The clutch switching valve 5 is switched between a release side position in which the lock-up clutch 32 is released and an engagement side position in which the lock-up clutch 32 is engaged according to the switching signal pressure P _sw.
2 and the drive current I _SLU supplied from the electronic control unit 42
Generating a slip control signal pressure P _SLU corresponding to a linear solenoid valve 54, the pressure difference between the engagement side oil chamber 35 and the disengagement-side oil chamber 33 in accordance with the slip control signal pressure P _SLU output from the linear solenoid valve 54 And a slip control valve 56 for adjusting ΔP and controlling the slip amount of the lock-up clutch 32.

In FIG. 3, a pump 60 for sucking and pumping the hydraulic oil recirculated to a tank (not shown) through a strainer 58 is driven to rotate by the engine 10. The operating hydraulic pressure pumped from the pump 60 is supplied to the first pressure regulating valve 62 of an overflow type by the first pressure regulating valve 62.
It is adapted to be pressurized line pressure Pl ₁ two-tone. This first
The pressure regulating valve 62 generates a first line pressure Pl ₁ that increases in accordance with the throttle pressure output from a throttle valve opening detection valve (not shown), and outputs the generated first line pressure Pl ₁ via a first line oil passage 64. The second pressure regulating valve 66 is an overflow type pressure regulating valve. The second pressure regulating valve 66 regulates the hydraulic oil discharged from the first pressure regulating valve 62 on the basis of the throttle pressure, so that the second pressure regulating valve 66 corresponds to the output torque of the engine 10. A line pressure Pl ₂ is generated. The third pressure regulating valve 68 is a pressure reducing valve that uses the first line pressure Pl ₁ as a source pressure, and generates a constant third line pressure Pl ₃ . Also, the manual valve 70 is shifted operating lever 196 is at a R range, generates a R range pressure P _R. Then, OR valve 72, pressure actuating the brake B ₂ that engages when it is the second-speed gear stage or P
_B2 and selects either the high side of the R range pressure P _R is output.

The clutch switching valve 52 is connected to the release-side oil chamber 3.
3, an engaging port 82 communicating with the engaging oil chamber 35, an input port 84 to which the second line pressure Pl ₂ is supplied, and an engaging oil chamber when the lockup clutch 32 is released. 35, a second discharge port 88 through which the hydraulic oil in the release-side oil chamber 33 is discharged when the lock-up clutch 32 is engaged,
A supply port 90 through which part of the hydraulic oil discharged from the pressure regulating valve 66 is supplied for cooling during the engagement period of the lock-up clutch 32, a spool valve element 92 for switching the connection state of the ports, and a spool A spring 94 for urging the valve 92 toward the off-side position, a plunger 96 arranged to be able to abut on an end of the spool valve 92 on the spring 94 side, and end faces of the spool valve 92 and the plunger 96 oil chamber 100 for receiving an oil chamber 98 provided between them to exert a R range pressure P _R, the first line pressure Pl ₁ to act on the end surface of the plunger 96
And an oil chamber 102 for receiving the switching signal pressure P _sw in order to generate a thrust toward the on-side position by applying the switching signal pressure P _sw from the third solenoid valve 50 to the end face of the spool valve element 92. It has.

In the third solenoid valve 50, in a non-excited state (OFF state), the communication between the oil chamber 102 and the OR valve 72 is interrupted by a spherical valve and the oil chamber 102 is set to a drain pressure. state), the communicated between oil chamber 102 and the OR valve 72 exerts a switching signal pressure P _sw in the oil chamber 102. Therefore, when the third solenoid valve 50 is in the off state, the oil chamber 1
02, the switching signal pressure P _sw from the third solenoid valve 50 is not applied, and the spool valve 92 is turned off according to the urging force of the spring 94 and the first line oil pressure Pl ₁ acting on the oil chamber 100. Since the input port 84 and the first discharge port 86 communicate with each other, the oil pressure P _off in the release-side oil chamber 33 becomes lower than the engagement-side oil. The hydraulic oil in the engagement side oil chamber 35 is released from the first discharge port 86, the oil cooler 104, and the check valve 106 at the same time when the lock-up clutch 32 is released by increasing the hydraulic pressure P _on in the chamber 35. Is discharged to the drain through

On the other hand, when the third solenoid valve 50 is in the ON state, the switching signal pressure P _sw from the third solenoid valve 50 is applied to the oil chamber 102, and the spool valve element 92 applies the urging force of the spring 94. And the first line oil pressure Pl ₁ acting on the oil chamber 100, it is located at the ON side position.
Input port 84, engagement side port 82, release side port 80
And the second discharge port 88, and the supply port 90 and the first discharge port 86, respectively.
At the same time the hydraulic pressure P _on the lock-up clutch 32 is higher than the hydraulic pressure P _off in the release side oil chamber 33 of the inner is engaged, the hydraulic fluid in the release side oil chamber 33 is the second discharge port 8
8 and drain to the drain via the slip control valve 56.

[0019] The linear solenoid valve 54, the third line pressure Pl ₃ fixed to be generated in the third pressure regulating valve 68 to a pressure reducing valve to source pressure, from the electronic control unit 42 as shown in FIG. 4 A signal pressure P _SLU for slip control which increases with the drive current I _SLU is generated, and the signal pressure P _SLU for slip control is applied to the slip control valve 56. The linear solenoid valve 54 includes a supply port 110 to which the third line pressure Pl ₃ is supplied, an output port 112 to output the slip control signal pressure P _SLU , a spool valve element 114 for opening and closing them, and a spool valve element 114. 115 for urging the spool valve 114 in the valve closing direction, a spring 116 for urging the spool valve element 114 in the valve opening direction with a smaller thrust than the spring 115, and applying the spool valve element 114 in the valve opening direction in accordance with the drive current _ISLU . And an oil chamber 120 for receiving a feedback pressure (slip control signal pressure P _SLU ) for generating a thrust in the valve closing direction on the spool valve element 114. Reference numeral 114 denotes an urging force in the valve opening direction by an electromagnetic solenoid 118 and a spring 116, and a spring 115 and a filter. The operation is performed so that the biasing force in the valve closing direction due to the feedback pressure is balanced.

The slip control valve 56 has a line pressure port 130 to which the second line pressure Pl ₂ is supplied, a receiving port 132 for receiving hydraulic oil in the release side oil chamber 33 discharged from the second discharge port 88, A drain port 1 for discharging the hydraulic oil received in the receiving port 132
34, the receiving port 132 and the drain port 134 are made to communicate with each other, and the hydraulic oil in the release-side oil chamber 33 is discharged, so that the pressure difference ΔP (= P) between the engagement-side oil chamber 35 and the release-side oil chamber 33. The second line pressure Pl ₂ is provided in the release side oil chamber 33 by communicating between the direction toward the first position (on the right side in FIG. 3) where the _on- P _off is increased and the receiving port 132 and the line pressure port 130. And a spool valve element 136 movably provided in a direction toward a second position (the left position in FIG. 3) for reducing the ΔP, and the spool valve element 136 is moved toward the first position. A plunger 138 arranged to be able to abut against the spool valve element 136 for biasing, the plunger 138 and the spool valve element 1
And a signal pressure oil chamber 140 for receiving the slip control signal pressure P _SLU to cause the plunger 138 and the spool valve element 136 to generate thrusts in directions away from each other by causing the slip control signal pressure P _SLU to act on the plunger 138 and the spool valve 136. ,
An oil chamber 142 that receives the oil pressure P _off to cause the plunger 138 to generate a thrust in the direction toward the first position by causing the plunger 138 to act on the oil pressure P _off in the release-side oil chamber 33; Spool valve 13
6, an oil chamber 144 for receiving the oil pressure P _on to generate a thrust in the direction toward the second position on the spool valve element 136 by causing the oil pressure P _on in the engagement side oil chamber 35 to act on the spool valve element 136; A spring 146 housed in the chamber 140 and biasing the spool valve element 136 in the direction toward its second position.

Here, the plunger 138 is formed with a first land 148 and a second land 150 having sectional areas A ₁ and A ₂ that become smaller in order from the oil chamber 142 side. the third land 152 is the cross-sectional area a ₃ from the signal pressure oil chamber 140 side, the same cross-sectional area a ₄ and smaller a ₁ than its cross-sectional area a ₃ 4
Fifth lands 154, and the same cross-sectional area A ₅ and A ₁
A land 156 is formed. The cross-sectional areas of these lands have a relationship of A ₃ > A ₁ (= A ₄ = A ₅ )> A ₂ . Therefore, the clutch switching valve 52 is in the ON state, and the slip control signal pressure P _SLU is relatively small.
Is established, the plunger 138 abuts on the spool valve element 136 to operate integrally with each other, and the pressure difference Δ having a magnitude corresponding to the slip control signal pressure P _SLU.
P is formed. At this time, the pressure difference ΔP slope by Equation 2 to the slip control signal pressure P _SLU is [(A ₃ -A
₂ ) / A ₁ ]. In addition,
In Equation 2, F _s is the biasing force of the spring 146.

[0022]

(Equation 1)

[0023]

(Equation 2)

However, when the slip control signal pressure P _SLU becomes larger than a predetermined value P _A , the relationship shown in Expression 3 is established. The predetermined value P _A is a value that is determined in advance so as to obtain a change range ΔP _slip of the pressure difference ΔP of a sufficient magnitude necessary for the slip control of the lock-up clutch 32. Each cross-sectional area and the like are set so that the relationship shown in Expression 3 is satisfied when the pressure P _SLU becomes the value P _A. For this reason, the plunger 138 and the spool valve element 136 are separated from each other, and the spool valve element 136 is operated so that Equation 4 is satisfied. However, in a state in which the spool valve element 136 is operated so that Equation 4 is satisfied, the slip control valve 56
Since the receiving port 132 and the drain port 134 are configured to communicate with each other, the hydraulic pressure P _off in the release-side oil chamber 33 further decreases and becomes the atmospheric pressure, so that ΔP = P _on Complete engagement is established. The solid line in FIG. 5 shows a change characteristic of the pressure difference ΔP obtained by the operation of the slip control valve 56 configured as described above with respect to the slip control signal pressure P _SLU .

[0025]

(Equation 3)

[0026]

(Equation 4)

As shown in FIG. 5, when the slip control signal pressure P _SLU becomes small and becomes equal to or less than the value P _B that satisfies Equation 5, the pressure difference ΔP = 0, so that the switching valve 52 Is in the ON state, the lock-up clutch 32 is in the released state.

[0028]

(Equation 5)

Returning to FIG. 1, the vehicle is provided with a TRC / ESC control device 178 for executing traction control and skid control. In the traction control, in order to suppress a slip when accelerating on a slippery road surface such as a snowy road or a frozen road, a slip ratio of a driving wheel is calculated based on a signal from a wheel speed sensor (not shown), and the slip ratio is calculated. A brake (not shown) is operated so as to be within a preset traction control area.
In the skid control, the speed, acceleration / deceleration, and vehicle speed of each wheel are calculated based on a signal from a wheel speed sensor (not shown) in order to increase the directional stability of the vehicle during braking. The slip ratio of each wheel is calculated from the wheel speed and the vehicle speed, and a brake (not shown) is operated so that the slip ratio of each wheel falls within a preset skid control region. While the traction control or the anti-skid control is being executed, a signal indicating that the traction control or the anti-skid control is being performed is output from the TRC / ESC control device 178 to the electronic control device 42.

The electronic control unit 42 includes a CPU 182, an RO
A so-called microcomputer comprising an M184, a RAM 186, an interface (not shown), etc., includes a throttle valve 1 provided in an intake pipe of the engine 10 and opened / closed by operating an accelerator pedal (not shown).
A throttle sensor 188 for detecting the opening of the engine 87; an engine speed sensor 1 for detecting the speed of the engine 10
90, an input shaft rotation sensor 192 for detecting the rotation speed of the input shaft 20 of the automatic transmission 14, and a counter shaft rotation sensor 19 for detecting the rotation speed of the counter shaft 40 of the automatic transmission 14.
4. The operation position of the shift operation lever 196, that is, L,
From the operation position sensor 198 for detecting any of the S, D, N, R, and P ranges, a signal indicating the throttle valve opening degree TA, the engine speed _Ne (the pump wheel speed N
_P , ie, a signal representing the input-side rotational speed of the lock-up clutch 32), a signal representing the input shaft rotational speed N _in (turbine wheel rotational speed _NT , ie, the output-side rotational speed of the lock-up clutch 32), and the vehicle speed SPD. signal representing the output shaft speed N _out corresponding, signals representing the operating position P _s of the shift lever 196 is adapted to be supplied. The CPU 182 of the electronic control unit 42
Using the temporary storage function of the AM 186,
Processing the input signal according to the program stored in 4,
The shift control of the automatic transmission 14 and the engagement control of the lock-up clutch 32 are executed in accordance with a main routine (not shown) to control the first solenoid valve 46, the second solenoid valve 48, the third solenoid valve 50, and the linear solenoid valve 54. Control each.

In the above-described shift control, the data is stored in the ROM 184 in advance.
From the multiple types of shift diagrams remembered,
The corresponding shift diagram is selected, and the vehicle travel is determined from the shift diagram.
Line state, for example, throttle valve opening TA and output shaft rotation speed
Degree N_outIs determined based on the vehicle speed calculated from
The first solenoid valve is determined so that the transmission gear stage is obtained.
When the second solenoid valve 48 is driven, the automatic change is performed.
Clutch C of gearbox 14 ₀ , C₁ , C_Two , And brake
B₀ , B₁ , B_Two , B_Three Operation is controlled and the forward four-stage
One of the gears is established.

The engagement control of the lock-up clutch 32 is executed during traveling at the second speed, the third speed, and the fourth speed, and the engagement control includes: Based on the relationship shown in FIG. 6 stored in advance in ROM 184, the traveling state of the vehicle, for example, output shaft rotation speed (vehicle speed) N
_{Based on out} and the throttle valve opening TA, it is determined whether the lock-up clutch 32 is in the release area, the slip control area, or the engagement area. This relationship is selected from a plurality of types of relationships stored in advance according to the actual gear position. In FIG. 6, the coupling effect is maintained on the release region side and the low throttle valve opening side with respect to the boundary between the engagement region and the release region in order to improve fuel economy as much as possible without impairing drivability. In addition, a slip control region is provided for absorbing the torque fluctuation of the engine 10 while performing the control.

When it is determined that the running state of the vehicle is within the engagement region shown in FIG. 6, the third solenoid valve 50 is excited to turn on the clutch switching valve 52, and at the same time the linear solenoid valve 54 is turned on. since the drive current I _SLU for is set to the minimum drive current (rated value), the lock-up clutch 32 is engaged. When it is determined that the running state of the vehicle is within the release area shown in FIG.
Is de-energized and the clutch switching valve 52 is turned off, so that the drive current I to the linear solenoid valve 54 is
_The lock-up clutch 32 is released regardless of the _SLU . When it is determined that the running state of the vehicle is within the slip control region shown in FIG. 6, the third solenoid valve 50 is excited and the clutch switching valve 52 is turned on, and at the same time,
The drive current I _SLU for the linear solenoid valve 54 is adjusted, for example, according to equation (6). That is, for example, the target slip rotation speed N _slip ^T in the steady state determined from the relationship shown in FIG. 7 and the actual slip rotation speed N _slip (=
The drive current I _SLU is calculated and output so that the deviation ΔN (= N _slip −N _slip ^T ) from N _e −N _T ) is eliminated.

FIG. 8 is a functional block diagram for explaining a main part of the control function of the electronic control unit 42. As shown in FIG. In the figure, a torque converter 12 with a lock-up clutch 32 is interposed in a power transmission path from the engine 10 to the drive wheels 17 via the automatic transmission 14 and the differential gear device 15, and the running state of the vehicle is changed. Is provided within a preset slip region of FIG. 6, a slip control means 200 is provided to make the slip amount N _slip of the lock-up clutch 32 coincide with the target slip amount N _slip ^T obtained from the relationship of FIG. . The rotation fluctuation determining means 202 determines the occurrence of rotation fluctuation transmitted from the drive wheels 17 to the lock-up clutch 32 by running on rough roads with severe unevenness, traction control, anti-skid control, and the like. When it is determined by the fluctuation determining means 202 that the rotational fluctuation transmitted from the drive wheel 17 toward the lockup clutch 32 has occurred, the slip control by the slip control means 200 is prohibited by the slip control prohibiting means 204.

The main control operation of the electronic control unit 42 will be described below. FIG. 9 is executed when the vehicle state is within the slip region shown in FIG. Step SA in FIG.
In 1, for example, irregularities such that the rotation fluctuation of the output shaft rotation speed _Nout obtained based on the signal from the counter shaft rotation sensor 194 or the pulsation cycle and amplitude of the vehicle speed SPD exceed a predetermined judgment reference value. It is determined whether or not the vehicle is traveling on a rough road. This step SA1 corresponds to the rotation fluctuation determining means 202.

If the determination at step SA1 is negative, the routine proceeds to step SA4 where the timer counter CTSLIP
It is determined whether or not the timed content of IH is smaller than a predetermined reference value KSLIP. Normally, the timer counter C
Since TSLIPIH has not been activated and the determination in step SA4 is affirmed, this routine is terminated, and the electronic control unit 42 matches the slip amount N _slip of the lock-up clutch 32 with the target slip amount N _slip ^T. The feedback control is continued.

If the vehicle starts running on a rough road in the above state, the determination in step SA1 is affirmative. Therefore, in step SA2 corresponding to the slip control prohibiting means 204, the lock-up by the electronic control unit 42 is performed. After the slip control of the clutch 32 is stopped, in step SA3, the timer operation of the timer counter CTSLIPIH is started, and this routine is ended.

If the vehicle has finished traveling on a bad road while the above steps are being repeatedly executed, the determination in step SA1 is denied. In step SA4, the time count of the timer counter CTSLIPIH is set to a predetermined reference value KSLIP. It is determined whether it is smaller than. Initially, the determination in step SA4 is affirmed. However, if the elapsed time from the stoppage of the slip control exceeds the time corresponding to the determination reference value KSLIP, the determination in step SA4 is denied, so that the slip control is permitted in the subsequent step SA5, and the timer is determined in step SA6. After the content of the counter CTSLIPIH is cleared to "0", this routine is terminated.

FIG. 10 shows the lock-up clutch 32.
This is a routine for correcting the shift diagram used for the shift control of the automatic transmission 14 in relation to the suspension of the slip control. In step SB1 of FIG.
A2 determines whether the slip control is blocked. If the slip control is not blocked, the determination in step SB1 is denied.
In FIG. 11, for example, a shift-up shift diagram when the slip control is permitted, which is indicated by a solid line in FIG. 11, is selected. However, if the slip control is blocked, the above step SB1 is executed.
Therefore, in step SB3, for example, a shift-up shift diagram during slip control inhibition indicated by a broken line in FIG. 11 is selected. In FIG. 11, the shift line at the time of slip control inhibition shown by the broken line is shifted to a lower vehicle speed side than the shift line at the time of slip control permission shown by the solid line.

As described above, according to the present embodiment, in step SA1 corresponding to the rotation fluctuation determining means 202, the lock-up clutch is driven from the driving wheel 17 by running on a rough road having severe unevenness, traction control, anti-skid control, and the like. When it is determined that the rotation fluctuation transmitted to the lock control clutch 32 has occurred, the slip control of the lock-up clutch 32 is prohibited in step SA2 corresponding to the slip control prohibition unit 204. Therefore, traveling on rough roads with severe unevenness,
By traction control, anti-skid control, etc.
In the running state where the rotation fluctuation toward the lockup clutch from the driving wheel is transmitted, or it is difficult detection of the actual slip amount N _slip of the lock-up clutch _{32 (= N e -N T)} , the target slip amount N _slip ^T and actual slip amount N _slip
The inconvenience that the drivability is impaired due to the unstable feedback control for matching with the above is solved.

Further, according to the present embodiment, in order to stop the slip control during the occurrence of the judder, the judder of the lock-up clutch 32 is detected based on the amplitude and the frequency of the change of the slip amount N _slip during the slip control. Or
Or when and detect the judder of the lock-up clutch 32 based on the amplitude and frequency of the rotation fluctuation of the output shaft rotation speed N _out, there is an advantage that erroneous detection is prevented.

Further, according to the present embodiment, the automatic transmission 14
The shift line for upshifting used in the shift control of the first embodiment has been changed to the lower vehicle speed side when the slip control is inhibited, compared with the shift line when the slip control is permitted, so that the engine rotation speed _Ne is too high. Is prevented, fuel efficiency is improved, and the inconvenience of being unable to upshift is suitably eliminated. That is, for example, as shown in FIG.
_{The value e} is larger by a predetermined width when the slip control is stopped than when the slip control is stopped. Therefore, when the slip control is stopped, especially at a low throttle opening and a high vehicle speed, FIG.
As shown in FIG. 3, the output torque of the engine 10 decreases,
In addition, as shown in FIG.
And the output shaft torque of the torque converter 12 decreases. Therefore, conventionally, because I also used a shift-up speed change line for in slip control during the slip control inhibition, higher a state shift point vehicle speed is too high, the engine rotational speed N _e in the traveling discomfort In some cases, the driving torque becomes lower than the running resistance and the upshift cannot be performed.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 15 is a flowchart for explaining another control operation example of the electronic control unit 42. In step SC1 in the figure, it is determined whether the slip control of the lock-up clutch 32 is being performed. If the slip control is not being performed, the determination in step SC1 is denied, and it is determined in step SC6 whether or not the content of the flap F1 is "1". The flag F1 indicates that the slip control is stopped when the content thereof is "1". Initially, the determination in step SC6 is denied, so that after the content of the flap F1 is cleared to "0" in step SC8, it is determined whether or not the slip control start condition is satisfied in step SC9, in other words, Fig. 6
It is determined whether or not the vehicle is within the slip region. If the determination in step SC9 is denied, this routine is ended. If the determination is affirmed, slip control of the lock-up clutch 32 is started in step SC10, and the timer counter C is started in step SC11.
The contents of TSLIPIH are cleared to "0".

When the slip control of the lock-up clutch 32 is started in step SC10, the determination in step SC1 in the next control cycle is affirmed, so that in the subsequent step SC2 corresponding to the rotation fluctuation determining means 202, Whether or not the vehicle is under traction control (TRC) control or anti-skid (ESC) control is determined based on a signal from the TRC / ESC control device 178. If the determination in step SC2 is negative, the present routine is terminated and slip control, that is, feedback control for making the slip amount N _slip of the lock-up clutch 32 equal to the target slip amount N _slip ^T by the electronic control unit 42 is performed. To be continued.

However, when the traction control control or the anti-skid control is started, the determination in step SC2 is affirmed, and the slip control of the lock-up clutch 32 is blocked in step SC3 corresponding to the slip control prohibiting means 204. After that, in step SC4, the content of the flag F1 is set to "1", and in the following step SC5, the timer operation of the timer counter CTSLIPIH is started, and this routine is ended.

When the traction control control or the anti-skid control of the vehicle ends while the above steps are repeatedly executed, the judgment in step SC1 is denied, and the judgment in step SC6 is affirmed. In the above, the count value of the timer counter CTSLIPIH is set to a predetermined reference value KSL.
It is determined whether or not the IP has been exceeded. Initially, the determination in step SC7 is denied, so this routine ends. However, if the elapsed time from the suspension of the slip control exceeds the time corresponding to the determination reference value KSLIP, the determination in step SC7 is affirmed, and the subsequent step S7 is performed.
After the content of the flag F1 is cleared to "0" in C8, it is determined in step SC9 whether a slip control start condition is satisfied. If the determination is affirmative, slip control is performed in step SC10. After the restart, the content of the timer counter CTSLIPIH is cleared to "0" in step SC11, and then this routine is terminated.

In the traction control control or the anti-skid control, the brake is operated intermittently so that the drive wheels 17
When the occurrence of such rotation fluctuation is determined in step SC2, the slip control is stopped in step SC3. Therefore, as in the above-described embodiment, the lock-up clutch is locked. It is difficult to detect the actual slip amount N _slip (= N _e −N _T ), or the target slip amount N _slip ^T and the actual slip amount N
The inconvenience that the drivability is impaired due to the unstable feedback control for matching the _slip is eliminated.

Further, according to the present embodiment, the slip control is stopped immediately after the traction control is started. Therefore, even if the turbine rotational speed _NT is suddenly reduced by the traction control, the slip of the lock-up clutch 32 is prevented. Heat generation due to an increase in the amount is suitably prevented.

FIG. 16 shows, for example, a step SC20 between steps SC1 and SC2 in the flowchart of FIG.
9 shows another example of the present invention, in which is inserted. Step SC
At 20, it is determined whether the cruise control control of the vehicle is in operation. If the determination in step SC20 is negative, step SC2 and subsequent steps are executed, but if affirmative, step SC3 and subsequent steps are executed. According to the present embodiment, the slip control of the lock-up clutch 32 is prevented during the cruise control that controls the throttle valve so that the vehicle speed SPD matches the preset target vehicle speed. There is an advantage that the deterioration of the characteristics is suitably prevented.

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

For example, in step SA1 of the above-described embodiment,
In the above, the rough road was detected based on the amplitude and frequency of the rotation fluctuation of the output shaft rotation speed _Nout , but based on the signal from the sensor for detecting the expansion and contraction of the suspension, the amplitude and frequency of the expansion and A bad road may be determined when the determination criterion is exceeded, or a bad road may be determined based on the fluctuation width and frequency of the vertical acceleration detected by the acceleration sensor fixed to the vehicle.

Further, the clutch switching valve 52 of the above-described embodiment is used.
Was turned on and off in accordance with the switching signal pressure P _sw supplied to the oil chamber 102 from the third solenoid valve 50, but was turned on and off in accordance with the slip control signal pressure P _SLU output from the linear solenoid valve 54. Is also good. In this case, when the slip control signal pressure P _SLU falls below the value P _B shown in FIG.
When the slip control signal pressure P _SLU exceeds its value P _B , the spool valve 92 of the clutch switching valve 52 is turned on against the urging force of the spring 94. , The urging force of the spring 94, the pressure receiving area of the spool valve element 92, and the like are set.

In the above-described embodiment, the stepped planetary gear type automatic transmission 14 is provided after the torque converter 12, but may be a continuously variable transmission.

In the above-described embodiment, the torque converter 12 with the direct coupling clutch has been described.
A fluid coupling with a direct coupling clutch may be used.
In short, any hydraulic transmission having a direct coupling clutch may be used.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing a vehicle power transmission device to which a slip control device according to one embodiment of the present invention is applied.

FIG. 2 is a diagram showing an automatic transmission including the torque converter with a lock-up clutch shown in FIG. 1;
5 is a table illustrating a relationship between a combination of operation of solenoid valves and a shift speed obtained by the combination.

FIG. 3 is a diagram illustrating a main configuration of a hydraulic control circuit of FIG. 1;

FIG. 4 is a view showing output characteristics of the linear solenoid valve of FIG. 3;

5 is a characteristic of a slip control valve provided in the hydraulic control circuit of FIG. 3, illustrating a relationship between a pressure difference ΔP between an engagement oil chamber and a release oil chamber and a slip control signal pressure P _SLU. FIG.

FIG. 6 is a diagram illustrating a relationship between a running state of the vehicle and an engaged state of a lock-up clutch, which is stored in the electronic control device of FIG. 1;

7 is a diagram illustrating a relationship stored in the electronic control device of FIG. 1 for determining a target slip rotation speed in a steady state.

FIG. 8 is a functional block diagram illustrating main functions of the electronic control device of FIG. 1;

FIG. 9 is a flowchart illustrating a slip control operation of a lock-up clutch, which is a main part of the operation of the electronic control device of FIG. 1;

10 is a flowchart illustrating an operation of changing a shift-up shift line used for shift control during slip control inhibition of a lock-up clutch, which is a main part of the operation of the electronic control device in FIG. 1;

FIG. 11 is a shift diagram showing a shift-up shift line changed by the operation of FIG. 10;

FIG. 12 is a time chart illustrating a change in engine speed during slip control and during slip control inhibition.

FIG. 13 is a diagram illustrating output torque characteristics of the engine of FIG. 1;

FIG. 14 is a diagram illustrating characteristics of the torque converter of FIG. 1;

FIG. 15 is a view corresponding to FIG. 9 in another embodiment of the present invention.

FIG. 16 is a diagram illustrating a main part of a flowchart in another embodiment of the present invention.

[Explanation of symbols]

 10: Engine 17: Drive wheel 32: Lock-up clutch (direct coupling clutch) 200: Slip control means 202: Rotation fluctuation determination means 204: Slip control prohibition means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-244964 (JP, A) JP-A-60-101356 (JP, A) JP-A-62-31769 (JP, A) JP-A-2- 138567 (JP, A) JP-A-4-70566 (JP, U) JP-A-5-21142 (JP, U) (58) Fields studied (Int. Cl. ⁶ , DB name) F16H 61/14

Claims (1)

(57) [Claims] 1. A vehicle having a fluid transmission with a direct coupling clutch in a power transmission path from an engine to driving wheels,
A slip control device for a vehicle direct-coupled clutch of a type including a slip control means for slipping the direct-coupled clutch when a running state of the vehicle enters a preset slip region, wherein the slip control device is directed from the drive wheel to the direct-coupled clutch. Rotation fluctuation determining means for determining the occurrence of rotational fluctuation transmitted by the drive wheel; and determining that the rotation fluctuation transmitted from the drive wheels toward the direct coupling clutch is determined by the rotation fluctuation determining means. And a slip control prohibiting means for prohibiting slip control by the control means.