JP3173331B2 - Slip control device for vehicle lock-up 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 lock-up clutch for a vehicle.

[0002]

2. Description of the Related Art In a vehicle equipped with a hydraulic transmission with a lock-up 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 lock-up clutch during acceleration traveling is further reduced. In order to improve the fuel efficiency of the vehicle by reducing the slip area, a slip area is provided between the release area and the engagement area of the lock-up clutch, and the lock-up clutch is half-engaged in the slip area. It has been proposed to execute the slip control so that the slip amount, that is, the difference between the rotation speed of the pump wheel and the rotation speed of the turbine wheel, follows a predetermined target slip rotation speed. Also, in a vehicle equipped with a fuel cut device that shuts off fuel for the engine in a region where the engine rotation speed is higher than a preset fuel cut rotation speed during deceleration driving, the engine rotation speed is also reduced during deceleration driving. It has been proposed to execute the same slip control as described above in order to increase the fuel cut range by raising it.

During the slip control, the friction state of the lock-up clutch becomes unstable due to the deterioration of the hydraulic oil and the change in the surface state of the lock-up clutch, and the so-called judder phenomenon in which the slip rotation speed changes discontinuously. May occur. This judder phenomenon can be detected based on the fluctuation of the output shaft rotation speed of the fluid transmission device, that is, the fluctuation of the turbine rotation speed. However, the fluctuation of the turbine rotation speed also occurs when there is unevenness on the traveling road surface of the vehicle. For this reason, the slip control is stopped when the above-mentioned judder is detected based on the fluctuation of the turbine rotation speed, and when the fluctuation of the turbine rotation speed continues even during this suspension period, not the judder but the turbine rotation speed A slip control device that restarts the slip control has been proposed, considering that the variation of the slip control is caused by the road surface condition. For example, a slip control device described in Japanese Patent Application Laid-Open No. 4-224361 is that.

[0004]

However, in the above-described conventional slip control device, for example, in the case where vibrations due to the unevenness of the running road surface are continuously generated, the slip control is performed by the fluctuation of the turbine rotational speed. Is stopped, and the operation of restarting the slip control when it is determined that the slip control is not a judder based on the fluctuation of the turbine rotation speed during the slip control suspension period may be continuously repeated. There is a disadvantage that the traveling performance of the vehicle is impaired by the repetition of the above.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the drivability by restarting the slip control when the vehicle is traveling on a good road surface. It is an object of the present invention to provide a slip control device for a lock-up clutch for a vehicle which is not provided.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a vehicle having a lock-up clutch provided between a pump impeller and a turbine impeller. A slip control device for a lock-up clutch for a vehicle, comprising: a slip control unit configured to control a slip rotation speed of a lock-up clutch to be equal to a predetermined target slip rotation speed, wherein (a) a rotation speed of the turbine wheel. Rotation fluctuation detecting means for detecting fluctuations in the rotational speed of the turbine wheel, and (b) stopping slip control by the slip control means when the fluctuation in the rotation speed of the turbine wheel is detected by the rotation fluctuation detecting means. Means, (c) based on fluctuations in the rotation speed of the turbine wheel during the suspension period of the slip control, the traveling road surface of the vehicle has no irregularities. A good road determining means for determining that the road is a road; and (d) when the good road determining means determines that the traveling path of the vehicle is a good road, the slip control suspending means has stopped the vehicle. And a slip control re-executing means for executing the slip control again.

[0007]

In this way, when the fluctuation of the rotation speed of the turbine wheel is detected by the rotation fluctuation detecting means, the slip control by the slip control means is stopped by the slip control stopping means. The good road determination means determines that the traveling road surface of the vehicle is a good road with no unevenness based on the fluctuation of the rotation speed of the turbine wheel during the suspension period of the slip control. Then, the slip control re-executing means causes the slip control stopped by the slip control stopping means to be executed again when the good road determination means determines that the traveling road of the vehicle is a good road.

Therefore, according to the present invention, when the good road determination means determines that the vehicle travels on a good road, the slip control stopped by the slip control stop means is executed again. In addition, when the vibration caused by the unevenness of the road surface is continuously generated, the suspension of the slip control and the repetition of the re-execution are eliminated, and the traveling performance of the vehicle is not impaired.

[0009] Preferably, the occurrence of judder in the lock-up clutch during the slip control based on the fluctuation of the rotation speed of the turbine wheel during the period when the slip control is stopped by the slip control stopping means. And a slip control stopping means for continuously stopping the slip control by the slip control means when judging of the lock-up clutch is determined by the judging means. . In this way, when judder occurs, the slip control is continuously stopped until the vehicle is in a state in which a change in the friction condition of the lock-up clutch can be expected, for example, from when the engine is once stopped to when it is restarted. There are advantages.

Preferably, the apparatus further comprises a rotation fluctuation counter which counts fluctuations in the rotation speed of the turbine wheel within a predetermined time range, and the rotation fluctuation detecting means has a function of counting the rotation fluctuation counter. This is to detect rotation fluctuation based on exceeding a predetermined judgment reference value.

[0011] Preferably, the predetermined first time period after the rotation fluctuation of the turbine wheel is detected by the rotation fluctuation detecting means during a period in which the slip control is stopped by the slip control stopping means. A bad road determination counter that counts a change in the rotation speed of the turbine wheel after a lapse of an elapsed time, wherein the judder determination unit determines when a predetermined second elapsed time longer than the first elapsed time has elapsed; Is determined based on the fact that the count content of the rough road determination counter is lower than a predetermined rough road determination reference value.

Preferably, the bad road determination counter is cleared every time a predetermined good road determination reference value is reached after the second elapsed time has elapsed.
There is further provided a good road determination timer for counting an elapsed time after the bad road determination counter is cleared, and the good road determination means counts a third elapsed time in which the count of the good road determination timer is set in advance. A good road is determined based on the excess.

[0013]

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 and drive wheels (not shown) through a torque converter 12 with a lock-up clutch, a stepped automatic transmission 14 composed of three sets of planetary gear units, and the like. It has become.

The torque converter 12 is used to
0 at the outer peripheral portion.
A pump impeller 18 having blades for generating a flow of hydraulic oil having a directional component directed toward the engine 10 and being fixed to the input shaft 20 of the automatic transmission 14, Having blades facing the blades of
A turbine wheel 22 that is rotated by receiving oil from the blades of the pump wheel 18, a stator wheel 28 fixed to a housing 26 that is a non-rotating member via a one-way clutch 24, and moves axially. A lock-up clutch 32 connected to the input shaft 20 via a piston 30 fitted to a hub of the turbine wheel 22 so as to be able to rotate relative to the shaft.

In the torque converter 12, the hydraulic pressure in the release-side oil chamber 33 of the engagement-side oil chamber 35 and the release-side oil chamber 33 divided by the piston 30 is increased, and the pressure in the engagement-side oil chamber 35 is increased. Is released, the piston 3
Since 0 is retracted and the lockup clutch 32 is disengaged, torque is transmitted at an amplification factor corresponding to the input / output rotation speed ratio of the torque converter 12. But,
The hydraulic pressure in the engagement-side oil chamber 35 is increased, and the release-side oil chamber 33 is increased.
When the hydraulic pressure in the inside becomes the minimum pressure, the piston 30 is advanced and the lock-up clutch 32 is pressed by the pump impeller 18 to be in the engaged state.
The two input / output members, that is, the crankshaft 16 and the input shaft 20 are directly connected.

The automatic transmission 14 is provided with a 3 coaxially arranged transmission.
Sets of single pinion type planetary gear sets 34, 36, 38
And a counter shaft (output shaft) 40 for transmitting power between an output gear 39 rotating with the ring gear of the planetary gear device 38 and a differential gear device (not shown). Some of the components of their planetary gear 34, 36, 38 is not only integrally connected to each other, are selectively connected to each other by three clutches _{C 0, C 1, C 2} . Further, the planetary gear units 34,
Some of the components of 36, 38 consist 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 connected to one another or to the housing by three one-way clutches F ₀ , F ₁ , F ₂ depending on the direction of their rotation. 26.

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 is operated by a hydraulic actuator. The operation of each of the hydraulic actuators is controlled by an electronic control unit for shifting 184 described later, whereby the operation shown in FIG. As shown in FIG.
A single shift stage / reverse speed is obtained. In FIG. 2, “1”
st "," 2nd "," 3rd "," O / D (overdrive) "
Represents a first gear, a second gear, a third gear, and a fourth gear, respectively, on the forward side, and the above-mentioned gear ratio is changed from the first gear to the fourth gear. It becomes smaller sequentially as it goes. 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.

FIG. 3 is a diagram for explaining the configuration of the vehicle control device. In the figure, a 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 hydraulic control for controlling engagement of the lock-up clutch 32. And a circuit. As is well known, the shift control hydraulic control circuit includes a first solenoid valve S1 and a second solenoid valve S2 that are driven on and off by solenoids No. 1 and No. 2, respectively. Valve S1
2 and FIG. 2 by a combination of operation of the second solenoid valve S2.
As shown in FIG. 7, the clutch and the brake are selectively operated to establish any one of the first to fourth gears.

The lock-up clutch control hydraulic control circuit is, for example, as shown in FIG. 4, a third solenoid valve S3 which is turned on and off by a solenoid 48 to generate a switching signal pressure P _sw , Lock-up relay valve 52 that is switched between a release side position in which lock-up clutch 32 is released and an engagement side position in which lock-up clutch 32 is engaged in accordance with use signal pressure P _sw.
A linear solenoid valve SLU for generating a slip control signal pressure P _SLU corresponding to the drive current I _SLU supplied from the shift electronic control device 184, and a linear solenoid valve S
A lock-up control valve 56 that controls the slip difference of the lock-up clutch 32 by adjusting the pressure difference ΔP between the engagement-side oil chamber 35 and the release-side oil chamber 33 according to the slip control signal pressure P _SLU output from the LU. Have.

In FIG. 4, a pump 60 for sucking and pumping the hydraulic oil recirculated to a tank (not shown) via a strainer 58 is driven by the engine 10 to rotate. 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 174 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 lock-up relay valve 52 includes a release port 80 communicating with the release oil chamber 33 and an engagement oil chamber 35.
An input port 84 to which the second line pressure Pl ₂ is supplied, a first discharge port 86 through which hydraulic oil in the engagement oil chamber 35 is discharged when the lock-up clutch 32 is released, Second discharge port 8 through which hydraulic oil in release-side oil chamber 33 is discharged when lock-up clutch 32 is engaged.
8, a supply port 90 through which part of the hydraulic oil discharged from the second pressure regulating valve 66 is supplied for cooling during the engagement period of the lock-up clutch 32, and a spool valve element 92 for switching the connection state of those ports A spring 94 for urging the spool valve element 92 toward the off-side position; a plunger 96 disposed so as to be able to contact the end of the spool valve element 92 on the spring 94 side; the end face of the 96 the oil chamber 98 provided between them to exert a R range pressure P _R, the plunger 9
An oil chamber 100 for receiving the first line pressure Pl ₁ acting on the end face of the spool 6, and a third solenoid valve S 3
It reacted with switching signal pressure P _sw since and an oil chamber 102 for receiving the switching signal pressure P _sw to generate a thrust directed to the on-side position.

In the non-excited state (OFF state), the third solenoid valve S3 shuts off the communication between the oil chamber 102 and the OR valve 72 by the spherical valve element and sets the oil chamber 102 to the drain pressure. oN state), the communicated between oil chamber 102 and the OR valve 72 exerts a switching signal pressure P _sw in the oil chamber 102. For this reason, when the third solenoid valve S3 is in the off state, the switching signal pressure P _sw from the third solenoid valve S3 is not applied to the oil chamber 102, and the spool valve element 92 is actuated by the urging force of the spring 94. The input port 84 and the release port 80 are communicated with each other, and the engagement port 82 and the first discharge port 86 are communicated with each other, since the port is located at the off-side position in accordance with the first line pressure Pl ₁ acting on the oil chamber 100. Therefore, the hydraulic pressure P _off in the release-side oil chamber 33 is higher than the hydraulic pressure P _on in the engagement-side oil chamber 35, and the lock-up clutch 32 is released. Is discharged to the drain via the first discharge port 86, the oil cooler 104, and the check valve 106.

On the other hand, when the third solenoid valve S3 is in the ON state, the switching signal pressure P _sw from the third solenoid valve S3 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 pressure P acting on the oil chamber 100
Since being is positioned on the ON side position against the and l _1, an input port 84 and the engagement-side port 82, the release side port 80 and the second exhaust port 88, the supply port 90 and communicating the first discharge port 86, respectively since provoking, at the same time the hydraulic pressure P lockup clutch 32 is also higher than _off in the hydraulic P _on the release side oil chamber 33 in the engaging-side oil chamber 35 is engaged, in the release side oil chamber 33 The hydraulic oil is supplied to the second discharge port 8
8 and discharged through the lock-up control valve 56 to the drain.

[0025] The linear solenoid valve SLU is the third line pressure Pl ₃ fixed to be generated in the third pressure regulating valve 68 to a pressure reducing valve to the source pressure, the shift electronic control unit as shown in FIG. 5 184 And generates a slip control signal pressure P _SLU that increases in accordance with the drive current I _SLU (ie, the drive duty ratio DSLU), and causes the slip control signal pressure P _SLU to act on the lock-up control valve 56. The linear solenoid valve SLU 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. 114 is an electromagnetic solenoid 1
The urging force in the valve opening direction by the spring 18 and the spring 116 and the urging force in the valve closing direction by the spring 115 and the feedback pressure are operated so as to be balanced.

The lock-up control valve 56 includes a line pressure port 130 to which the second line pressure Pl ₂ is supplied,
Release-side oil chamber 33 discharged from the second discharge port 88
A receiving port 132 for receiving the hydraulic oil therein, a drain port 134 for discharging the hydraulic oil received in the receiving port 132, and a communication between the receiving port 132 and the drain port 134 to allow the release side oil chamber 33 The first difference that increases the pressure difference ΔP (= P _on −P _off ) between the engagement side oil chamber 35 and the release side oil chamber 33 by discharging the hydraulic oil of
Direction toward position (left position in FIG. 4) and receiving port 13
The second line pressure Pl ₂ is supplied into the release-side oil chamber 33 by communicating between the second oil pressure line 130 and the line pressure port 130, and the ΔP is reduced toward the second position (the right position in FIG. 4). Spool valve 13 provided to be movable toward
6, a plunger 138 arranged to be in contact with the spool valve element 136 to urge the spool valve element 136 toward the first position, and a slip control signal pressure P _{SLU is applied} to the plunger 138. A signal pressure oil chamber 140 for receiving a slip control signal pressure P _SLU to generate a thrust in a direction toward the first position;
An oil chamber 142 for receiving the oil pressure P _off to cause the plunger 138 to generate a thrust toward the first position by causing the oil pressure P _off in the release-side oil chamber 33 to act on the plunger 138; An oil chamber 144 that receives the oil pressure P _on to apply a hydraulic pressure P _on in the engagement side oil chamber 35 to the valve element 136 to generate a thrust in the direction toward the second position on the spool valve element 136; A spring 146 housed within the chamber 144 and biasing the spool valve element 136 toward its second position.

Here, the plunger 138 is formed with a first land 148 and a second land 150 having cross-sectional areas A ₁ and A ₂ increasing in order from the oil chamber 142 side. the third land 152 and the fourth land 154 is formed is a cross-sectional area a ₃ from the signal pressure oil chamber 140 side. Accordingly, the plunger 138 abuts on the spool valve element 136 and operates integrally with each other, and a pressure difference ΔP (= P _on −P) having a magnitude corresponding to the slip control signal pressure P _{SLU is applied} to both sides of the piston 30.
_off ) is formed. That is, assuming that A ₁ = A ₃ , the pressure difference ΔP changes according to the slope [(A ₂ −A ₁ ) / A ₁ ] with respect to the slip control signal pressure P _{SLU according} to Equation 1. In Equation 1, F _s is the spring 1
Forty-six urging forces.

[0028]

(Equation 1)

FIG. 6 shows a change characteristic of the pressure difference ΔP obtained by the operation of the lock-up control valve 56 having the above-described structure with respect to the slip control signal pressure P _SLU . Therefore, the lock-up relay valve 52
Is in the on state, the slip control signal pressure P _SLU
Becomes larger, the engagement-side oil chamber 35 and the release-side oil chamber 33 are increased.
Is increased, the slip rotation speed NSLP of the lock-up clutch 32 is reduced.
Conversely, the pressure difference ΔP between the engagement-side oil chamber 35 and the release-side oil chamber 33 decreases as the slip control signal pressure P _SLU decreases, so that the slip rotation speed NSLP of the lock-up clutch 32 increases. You.

[0030] Returning to FIG. 3, the intake air in the vehicle, the engine speed sensor 160 for detecting the rotational speed N _P of the rotational speed N _E i.e. the pump impeller 18 of the engine 10, is sucked into the engine 10 through the intake pipe The intake air amount sensor 162 for detecting the amount Q, the engine 1 through the intake pipe
The intake air temperature sensor 164 for detecting the temperature T _AIR of the intake air sucked to zero, the throttle sensor 1 with an idle switch for detecting the fully closed state and the opening θ ₁ of the throttle valve 166 opened and closed by operating the accelerator pedal 165.
67, a vehicle speed sensor 168 for detecting the rotation speed of the output shaft of the automatic transmission 14, that is, the vehicle speed V, a cooling water temperature sensor 170 for detecting the cooling water temperature T _WA of the engine 10, and a brake sensor 172 for detecting that the brake pedal is operated. ,
Operation position of the shift lever 174 P _s That L,
An operation position sensor 176 for detecting any one of the S, D, N, R, and P ranges, and a rotation speed N of the turbine wheel 22
_T, ie, a turbine rotation speed sensor 178 for detecting the rotation speed of the input shaft 20 of the automatic transmission 14, and the hydraulic control circuit 4
4 is provided with an oil temperature sensor 180 for detecting the temperature T _OIL of the hydraulic oil. The signals output from the sensors are directly or indirectly supplied to the electronic control unit 182 for the engine and the electronic control unit 184 for shifting. The electronic control unit 182 for the engine and the electronic control unit 184 for shifting are interconnected via a communication interface, so that input signals and the like are supplied to each other as needed.

The electronic control unit 184 for shifting is a CPU, an R
A so-called microcomputer including an OM, a RAM, an interface, and the like. The CPU processes an input signal according to a program stored in a ROM in advance while using a temporary storage function of the RAM, and controls a shift of the automatic transmission 14 and The engagement control of the lock-up clutch 32 is executed according to a main routine (not shown), and the first solenoid valve S
1, the second solenoid valve S2, the third solenoid valve S3, and the linear solenoid valve SLU are respectively controlled.

In the above-mentioned shift control, the data is stored in the ROM in advance.
Corresponding to the actual gear stage from multiple types of shift diagrams
The shift diagram is selected, and the running state of the vehicle is
Condition, for example, throttle valve opening θ₁ And vehicle speed V
The gear position is determined by the
The first solenoid valve S1 and the second solenoid valve S2 are driven
As a result, the clutch C of the automatic transmission 14₀ , C₁ , C_Two ,
And brake B₀ , B ₁ , B_Two , B_Three Operation is controlled
And one of the four forward gears is established
You.

The engagement control of the lock-up clutch 32 is executed, for example, during traveling at the third speed and the fourth speed, and the engagement control is previously stored in the ROM. Based on the relationship shown in FIG. 7, based on the traveling state of the vehicle, for example, the output shaft rotation speed (vehicle speed) _Nout and the throttle valve opening TAP, any one of the release region, the slip control region, and the engagement region of the lock-up clutch 32 is performed. It is determined whether there is. This slip control area is
The lock-up clutch 32 is maintained in a slip state so as to be connected while absorbing torque fluctuations of the engine 10 for the purpose of improving fuel efficiency as much as possible without impairing drivability. FIG. 7 is used during acceleration running of the vehicle. Further, even during deceleration coasting of the vehicle, slip control of the lock-up clutch 32 is executed for the purpose of expanding the control range of the fuel cut control. That is, in the coasting state where the throttle valve opening TAP is zero, the slip control is executed until the fuel cutoff operation by the fuel cut device is terminated.

When it is determined that the running state of the vehicle is within the engagement region, the third solenoid valve S3 is excited to turn on the lock-up relay valve 52 and, at the same time, drive the linear solenoid valve SLU. Since the current I _SLU 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 range, the third solenoid valve S3 is de-energized and the lock-up relay valve 52 is turned off, so that the drive current for the linear solenoid valve SLU is reduced. The lock-up clutch 32 is released regardless of I _SLU . When it is determined that the running state of the vehicle is within the slip control region, the third solenoid valve S3 is excited to turn on the lock-up relay valve 52, and at the same time, the drive current for the linear solenoid valve SLU is increased. I _SLU
Is adjusted, for example, according to equation (2). That is, for example, the deviation ΔE (= N) between the target slip rotation speed TNSLP and the actual slip rotation speed NSLP (= N _E −N _T )
(SLP-TNSLP) is eliminated.
_{The SLU,} that is, the drive duty ratio DSLU is calculated and output.

[0035]

(Equation 2)

DFWD on the right side of the above equation 2 is, for example, a feedforward value which is a function of the output torque of the engine 10, KGD is a learning control value formed corresponding to the characteristics of each machine, and DFB is a learning control value. For example, as shown in Expression 3, the feedback control value is obtained by adding a proportional value, a differential value, and an integral value of the deviation ΔE.

[0037]

(Equation 3)

An electronic control unit 182 for the engine
This is also a microcomputer similar to the electronic control unit 184 for shifting, and its CPU executes various engine controls by processing input signals in accordance with a program stored in a ROM in advance. For example, in the fuel injection amount control, the fuel injection valve 186 is controlled in order to optimize the combustion state, in the ignition timing control, the igniter 188 is controlled in order to make the retard amount appropriate, and in the traction control, the driving wheels are controlled. Throttle actuator 190 for preventing slip and ensuring effective driving force and vehicle stability.
The second throttle valve 192 is controlled by, the fuel-cut control, in order to improve the fuel consumption, for a period exceed the fuel cut-off rotation speed N _CUT to engine rotational speed N _E is set in advance in the coasting fuel injection valve 186
Close.

FIG. 8 is a functional block diagram for explaining a main part of the control function of the electronic control unit 184 for shifting. 8, when the vehicle becomes the the traveling state or a deceleration state of the slip control region in FIG. 7 for example, the slip control means 196, the actual slip speed NSLP of the lock-up clutch 32 (= N _E -N _T) And outputs a control value DSLU calculated by the control formula of Expression 2 so that the target slip rotation speed TNSLP matches a preset target slip rotation speed TNSLP. When the rotation fluctuation detecting means 198 detects a fluctuation in the rotation speed _NT of the turbine wheel 22, the slip control suspending means 200 causes the slip control means 196.
Is stopped. Good road determination means 2
02 denotes a rotation speed _NT of the turbine wheel 22 during a period in which the slip control is stopped by the slip control stopping means 200.
It is determined that the traveling road surface of the vehicle is a good road without unevenness based on the fluctuation of the vehicle. That is, the good road determination means 202
While the fluctuation of the rotation speed _NT of the turbine wheel 22 during the suspension period of the slip control is continued, the good road determination is not performed, but when the rotation is stopped, the good road determination is performed. Then, the slip control re-executing means 204 includes the good road determination means 2
If it is determined that the vehicle is running on a good road, the slip control stopped by the slip control stopping means 200 is executed again.

Further, the judder judging means 206 determines whether the lock-up clutch 32 during the slip control based on the fluctuation of the rotation speed _NT of the turbine wheel 22 during the period when the slip control is stopped by the slip control stopping means 200. Judgment is determined. The slip control stopping means 208 stops the slip control by the slip control means 196 when the judging means 206 determines that the lock-up clutch 32 is judging.

Further, the rotation fluctuation detecting means 198
For example, the rotation speed N of the turbine wheel 22 _TIs set in advance.
Rotation fluctuation counter CJA that counts within a specified time range
The determination content of DA is a predetermined reference value tKNJA.
The rotation fluctuation is detected based on exceeding DA. Ma
In addition, the slip control is canceled by the slip control
During the suspension period, the rotation fluctuation detecting means 19
8 detects the rotation fluctuation of the turbine wheel 22
After the predetermined first elapsed time tKTJDC1 has elapsed.
To count the number of fluctuations in the rotational speed of the turbine wheel 22
A road determination counter CAKURO;
The stage 206 is located at a position longer than the first elapsed time tKTJDC1.
Bad road when fixed second elapsed time tKTJDC2 has elapsed
The count content of the determination counter CAKURO is set in advance.
Based on lower than rough road judgment reference value tKNAKURO
To determine judder.

The bad road determination counter CAKURO
Is cleared every time the preset good road determination reference value tKNRYORO is reached after the second elapsed time tKTJDC2 has elapsed, while the elapsed time since the bad road determination counter CAKURO is cleared is A good road determination timer CTJDC3 for counting is further provided.
The third elapsed time tKTJD in which the count content of 3 is set in advance
A good road is determined based on exceeding C3.

FIGS. 9 and 10 show the essential parts of the control operation of the shift electronic control unit 184, that is, the slip control routine and the flag switching routine, respectively. These routines are mutually parallel or serial. It is executed repeatedly.

In step SN1 of FIG. 9 (hereinafter, the steps are omitted), it is determined whether or not the content of the slip control prohibition flag XJLB1 is set to "1".
When the flag XJLB1 is set to "1", the slip control is not performed properly due to the occurrence of judder or the like due to deterioration of the hydraulic oil or deterioration of the surface state of the lock-up clutch 32 when the content is set to "1". , Which is cleared by operating an ignition key, for example.

If the determination of SN1 is affirmative, S
After the slip control is stopped by clearing the content of the flag XEXE to "0" at N8, the lock-up clutch 32 is released by turning off the lock-up relay valve 52 at SN9, Execution of the slip control is prevented. However, the above S
If the determination of N1 is denied, it is determined whether or not the slip control is being executed in SN2 based on the content of the flag XEXE.

Initially, the determination at SN2 is negative, so it is determined at SN3 whether the slip control start condition is satisfied. The slip control start conditions include:
This includes being in the slip control region of FIG. 7 or decelerating, and being in a steady state where the change in the throttle valve opening TAP is small. If the determination of SN3 is denied, the above SN8 and below are executed,
If affirmative, slip control is performed in SN4 corresponding to the slip control means 196, and the content of the flag XEXE is set to "1". In this slip control, the control output value DSLU is determined and output so that the actual control deviation ΔE is eliminated from Expression 2.

Next, in SN5, it is determined whether or not the content of the judder determination preparation flag XJRDY is set to "1". If the determination at SN5 is negative, the lock-up relay valve 52 is switched to the ON state at SN6, and the slip control is executed according to the control output value DSLU. However, if the determination at SN5 is affirmative, the lockup relay valve 52 is switched to the off state at SN9, so that the lockup clutch 32 is released and the control output value D
The slip control is stopped regardless of the output of the SLU.

Once the content of the flag XEXE is once set to "1" as described above, the determination of SN2 in the next control cycle is affirmative, so whether the condition for terminating the slip control in SN7 is satisfied or not. Is determined.
The conditions for terminating the slip control include that the vehicle is outside the slip control region of FIG. 7 or that the vehicle is not running at a reduced speed, and that the change in the throttle valve opening TAP is in a large transient state. If the determination of SN7 is denied, the control of SN4 and below is executed and the slip control state is continued. If the determination of SN7 is affirmative, the control of SN8 and below is executed and the slip control ends. Let me do.

In FIG. 10, in SO1, it is determined whether or not the slip control is being performed based on the content of the flag XEXE. If the determination of SO1 is denied, SO2
After the content of the rotation fluctuation counter CJADA is cleared to "0" in this routine, this routine is terminated and the above SO
Execution of 1 or less is repeated. If the determination of SO1 is affirmative, the judging determination preparation flag X is set in SO3.
It is determined whether or not the content of JRDY is “1”.

If the determination of SO3 is negative, S
Bad road determination counter CAK at O4, SO5, SO6
URO, elapsed time timer CTJDC, good road determination timer C
The content of TJDC3 is cleared to "0", and the count of the rotation fluctuation counter CJADA is incremented in SO7. The rotation fluctuation counter CJADA is cleared at predetermined time intervals, and repeatedly counts the number of rotation fluctuations of the turbine rotation speed _NT , for example, the upper peak point and the lower peak point of the rotation fluctuation within the time interval. And a plurality of the fixed time intervals are provided which are shifted from each other.

Next, in SO8 corresponding to the rotation fluctuation detecting means 198, it is determined whether or not the content of the rotation fluctuation counter CJADA has reached a predetermined reference value tKNJADA. This determination reference value tKNJADA
Is a value experimentally obtained in advance in order to detect a rotation fluctuation that affects the slip control. If the determination of SO8 is denied, this routine is terminated. If the determination is affirmed, the slip control suspending means 20 is terminated.
In SO9 corresponding to 0, the judder determination preparation flag XJ
After the content of RDY is set to "1", this routine is terminated. Thus, the judder determination preparation flag XJ
When the content of RDY is set to "1", the determination at SN5 is affirmed, the lock-up relay valve 52 is switched to the off state, and the slip control being executed is stopped. Time point t ₁ in FIG. 11 and FIG. 12 shows this state. FIG. 11 is a time chart showing the operation when the rough road determination is performed, and FIG. 12 is a time chart showing the operation when the judder determination is performed.

As described above, the judder determination preparation flag X
When the content of JRDY is set to "1", the determination of SO3 is affirmed in the next control cycle, so that the following SO1 is set.
0, the content of the elapsed time timer CTJDC that counts the elapsed time from the determination of the rotational fluctuation in the SO8 is counted as "1", and then the content of the elapsed time timer CTJDC is set in advance in SO11. It is determined whether or not one elapsed time tKTJDC1 or more has elapsed. The first elapsed time tKTJDC1 is a value set to correspond to a delay time from when the suspension of the slip control is executed to when the lock-up clutch 32 is reliably released, for example, about 0.2 seconds. The value is adopted. As a result, the influence of the friction fluctuation of the lock-up clutch 32 on the number of fluctuations of the turbine rotational speed counted by the bad road determination counter CAKURO is removed, and the turbine rotational speed is varied mainly by the influence of the road surface.

At first, this routine is terminated because the determination of SO11 is denied, but the first elapsed time t
When a time equal to or longer than KTJDC1 has elapsed, counting of the rough road determination counter CAKURO thereafter is permitted.
At O12, the rough road determination counter CAKURO counts up. This state is shown at time t _{2 in} FIGS. 11 and 12. This rough road determination counter CAKURO
Is one in which similarly to the rotation fluctuation counter CJADA counts the number fluctuations in the turbine rotational speed N _T, until there is an operation of clearing continues counting. Next, in SO13, it is determined whether or not the content of the elapsed time timer CTJDC has become the same value as the second elapsed time tKTJDC2 set in advance. This second elapsed time tKTJDC2 is
This is a necessary and sufficient time set in advance to determine the influence of road surface irregularities, and a value of, for example, about 0.7 seconds is employed.

Since the determination of SO13 is initially denied, it is determined in SO14 whether or not the content of the elapsed time timer CTJDC has become equal to or longer than the second elapsed time tKTJDC2 set in advance. Initially, this determination of SO14 is also denied, so this routine is terminated.

When the contents of the elapsed time timer CTJDC reach the preset second elapsed time tKTJDC2 while the above steps are repeatedly executed, the determination of SO13 is affirmed, and the content of the rough road determination counter CAKURO is determined at SO15. Is a predetermined rough road determination reference value t.
It is determined whether or not it is equal to or larger than KNAKURO. If the road is rough, there are many irregularities on the road surface.
Since the determination at 5 is affirmative, the routine is terminated after the content of the rough road determination counter CAKURO is cleared at SO16. T ₃ time points in FIG. 11 shows this state.

On the other hand, if the content of the rough road determination counter CAKURO does not reach the rough road determination reference value tKNAKURO during the slip control suspension period in which the content of the judder determination preparation flag XJRDY is "1",
Fifteen decisions are denied. In such a case, it is clear that the rotation fluctuation counter CJADA counts the rotation fluctuation due to the judder phenomenon of the lock-up clutch 32. Therefore, the content of the slip control prohibition flag XJLB1 is set to "1" in SO17. Is done. FIG.
2 t ₃ time points shows this state. As a result, since the determination of SN1 is affirmed, the slip control which has been suspended because the content of the judder determination preparation flag XJRDY is set to "1" is changed to the content of the slip control inhibition flag XJLB1 of "1". As a result, the slip control is further stopped. In the present embodiment, the SO 15 corresponds to the judder judging means 206 and the SO 15
17 corresponds to the slip control stopping means 208.

After the determination of SO13 is once affirmed as described above, the determination condition of SO14 is always satisfied.
Good road judgment reference value tKNRY in which the content of RO is set in advance
It is determined whether or not it is greater than ORO. Initially this SO
Since the determination of No. 18 is denied, “1” is added to the content of the good road determination timer CTJDC3 in SO19,
In the SO20 corresponding to the good road judgment means 202, the contents of the good road judgment timer CTJDC3 are set in a third
It is determined whether or not the elapsed time is tKTJDC3 or more. The third elapsed time tKTJDC3 is a predetermined time width so that it can be determined whether or not the number of rotation fluctuations of the turbine rotation speed _NT related to the unevenness of the road surface is small enough to determine that the road is good. Initially, this determination of SO20 is also denied, so this routine is terminated.

While the above steps are repeatedly executed, when the content of the bad road determination counter CAKURO becomes equal to or greater than the preset good road determination reference value tKNRYORO, S is determined.
Since the judgment of O18 is affirmed, SO22 and SO2
After the content of the bad road determination counter CAKURO and the content of the good road determination timer CTJDC3 are cleared at 3, the routine is terminated. T ₄ time in FIG. 11 shows this state.

However, while the above steps are repeatedly executed, if the content of the good road determination timer CTJDC3 becomes equal to or longer than the third elapsed time tKTJDC3, the determination of the SO20 is affirmed. In the SO21 corresponding to the means 204, the content of the judder determination preparation flag XJRDY is cleared to "0".
Thus, the determination of SN5 is denied, and the slip control of SN6 is restarted. T ₅ the time in FIG. 11 shows this state.

[0060] As described above, according to this embodiment, when the fluctuation of the rotational speed N _T of the turbine wheel 22 is detected by SO8 corresponding to the rotation variation detection means 198, the slip control stop means 200 The slip control by the slip control means 196 is stopped by the corresponding SO9. The SO 20 corresponding to the good road determination means 202 determines that the traveling road surface of the vehicle is a good road without unevenness based on the fluctuation of the rotation speed _NT of the turbine wheel 22 during the suspension period of the slip control. The SO 21 corresponding to the slip control re-executing means 204 determines that the slip control stopped by the slip control stopping means 200 when the good road determination means 202 determines that the traveling road of the vehicle is a good road. Is executed again. In this way, when the good road determination means 202 determines that the traveling path of the vehicle is a good road, the slip control stopped by the slip control stop means 200 is re-executed. Repetition of suspension and re-execution of the slip control in a case where vibration due to unevenness of the road surface occurs is eliminated, and the traveling performance of the vehicle is not impaired.

According to the present embodiment, the lock-up clutch 32 during the slip control is controlled based on the fluctuation of the rotation speed _NT of the turbine wheel 22 during the period when the slip control is stopped by the slip control stopping means 200. Judging means 206 for judging the occurrence of judder
(SO15) and when the judder judging means 206 judges that the lock-up clutch 32 is judging, the slip control stopping means 208 (SO1) for continuously stopping the slip control by the slip control means 196.
7) is further included. For this reason, when a judder occurs, there is an advantage that the slip control is stopped from a vehicle state in which a change in the friction condition of the lock-up clutch 32 can be expected, for example, from when the engine is once stopped to when it is restarted.

Further, according to the present embodiment, after the first elapsed time tKTJDC1 has elapsed, the counting of the bad road determination counter CAKURO is permitted while the lock-up clutch 32 is securely released. In addition, there is an advantage that the accuracy of judging is improved.

Further, in the present embodiment, during the period in which the slip control is stopped by the slip control stopping means 200, the rotation of the turbine wheel 2 is detected by the rotation fluctuation detecting means 198.
2 after a change in the rotation speed _NT of the second rotation is detected.
A bad road determination counter CAKURO that counts a change in the rotation speed _NT of the turbine wheel 22 after a lapse of the elapsed time tKTJDC1 is provided, and the judder determination means 206 performs a predetermined second elapsed time longer than the first elapsed time tKTJDC1. Bad road determination counter C when tKTJDC2 has elapsed
Judgment is determined based on the fact that the counting content of AKURO is lower than a preset rough road determination reference value tKNAKURO. After the second elapsed time tKTJDC2 has elapsed, the bad road determination counter CAKURO is cleared every time a predetermined good road determination reference value tKNRYORO is reached.
Is further provided with a good road determination timer CTJDC3 for counting an elapsed time since the clearing of the road.
02 determines a good road based on the fact that the count content of the good road determination timer CTJDC3 exceeds a third elapsed time tKTJDC3 set in advance. As described above, since the bad road determination counter CAKURO is also used for determining a bad road and a good road, there is an advantage that the control logic is simpler than preparing each counter.

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

[0065] For example, in the illustrated embodiment, in order to detect the rotation fluctuation of the rotating speed N _T of the turbine impeller 22 by the rotation variation detection means 198, the rotational speed N _T i.e. the automatic transmission of the turbine wheel 22 14 input shafts 2
Although the rotation speed of 0 is directly detected by the turbine rotation speed sensor 178, the rotation speed _NT may be detected indirectly. For example, the rotational speed N _out of the vehicle speed sensor 168 detected the counter axis (output shaft) 40, actually selected speed if Jozure the speed ratio I corresponding to the gear stage of the automatic transmission 14 has N _T Or if the wheel is provided with a rotational speed sensor, then multiplying the rotational speed by the reduction ratio and speed ratio I of the final reducer gives the rotational speed _NT , so However, since the rotation speed _NT of the turbine wheel 22 is substantially detected, it is not always necessary to directly detect the rotation speed _NT . In the case of indirect detection as described above, the turbine rotation speed sensor 178 may not be provided.

When the rotational speed _NT of the turbine wheel 22 is indirectly detected as described above, the detected rotational speed _{Nout of} the counter shaft (output shaft) 40 and the rotational speed of the wheels are directly changed. used in place of the speed N _T, it may be detected variation in rotational speed N _T of the turbine impeller 22 by the rotation variation detection means 198. That is, any change in the rotation speed _NT of the turbine wheel 22 may be substantially determined.

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

[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 block diagram illustrating a configuration of a control device provided in the vehicle of FIG. 1;

FIG. 4 is a diagram illustrating a configuration of a main part of a hydraulic control circuit in FIG. 3;

FIG. 5 is a diagram showing output characteristics of the linear solenoid valve of FIG. 4;

6 is a characteristic of a slip control valve provided in the hydraulic control circuit of FIG. 4, 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. 7 is stored in the shift electronic control device of FIG.
FIG. 4 is a diagram illustrating a relationship between a traveling state of the vehicle and an engagement state of a lock-up clutch.

8 is a functional block diagram for explaining a main part of a control function of the shift electronic control device of FIG. 3;

FIG. 9 is a flowchart illustrating a main part of a control function of the shift electronic control device of FIG. 3, and is a diagram illustrating a slip control routine.

FIG. 10 is a flowchart illustrating a main part of a control function of the shift electronic control device of FIG. 3, and is a diagram illustrating a flag switching routine.

FIG. 11 is a time chart for explaining the control operation of FIGS. 9 and 10 when a bad road is determined.

FIG. 12 is a time chart for explaining the control operation of FIGS. 9 and 10 when judging is determined.

[Explanation of symbols]

 18: Pump impeller 22: Turbine impeller 32: Lock-up clutch 196: Slip control means 198: Rotation fluctuation detection means 200: Slip control stop means 202: Good road judgment means 204: Slip control re-execution means 206: Judder judgment means 208: Slip control stopping means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-224361 (JP, A) JP-A-7-71593 (JP, A) JP-A-60-151457 (JP, A) JP-A-7-71 42768 (JP, A) JP-A-5-172240 (JP, A) JP-A-63-176865 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 61/14 601

Claims (2)

(57) [Claims] In a vehicle having a lock-up clutch provided between a pump wheel and a turbine wheel, slip control is performed so that a slip rotation speed of the lock-up clutch matches a predetermined target slip rotation speed. A slip control device for a lock-up clutch for a vehicle, comprising a control unit, a rotation fluctuation detection unit configured to detect a fluctuation in a rotation speed of the turbine wheel, and a rotation speed detection unit configured to detect a rotation speed of the turbine wheel by the rotation fluctuation detection unit. When a change is detected, a slip control stopping means for stopping the slip control by the slip control means, and based on a change in the rotational speed of the turbine wheel, the traveling road surface of the vehicle is on a good road with no unevenness. A good road determining means for determining that the vehicle is running on a good road by the good road determining means; , The slip control and a slip control rerun means for executing the slip control has been canceled again by discontinuation means, a slip lockup clutch control apparatus for a vehicle, which comprises. 2. A judder determination for judging occurrence of a lock-up clutch judder during the slip control based on a change in a rotation speed of the turbine wheel during a period in which the slip control is stopped by the slip control stopping means. And slip control stopping means for continuously stopping slip control by the slip control means when judging of the lock-up clutch is determined by the judging means. Slip control device for vehicle lock-up clutch.