JP3106865B2 - 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 lock control device for a vehicle lock-up clutch.

[0002]

2. Description of the Related Art In a vehicle equipped with a fluid 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 is further reduced. For the purpose of improving fuel efficiency, a slip region is provided between the release region and the engagement region of the lock-up clutch, and the actual slip amount, that is, the lock-up clutch is half-engaged in the slip region. It has been proposed to control the difference between the rotation speed of the pump wheel and the rotation speed of the turbine wheel so as to follow a predetermined target slip rotation speed.

In general, in the above-described slip control, a hydraulic system capable of guaranteeing complete engagement of a lock-up clutch is used to control a pressure difference between hydraulic pressures before and after the lock-up clutch. Since the slip amount is adjusted by changing the frictional force by the pressing force,
Since the slip amount of the lock-up clutch is sensitively changed by a slight change in the pressure difference, that is, a slight control operation amount, the feedback control system is relatively unstable. For this reason, if the conditions at the start of the slip control are different, hunting of the feedback control may occur and the control may become unstable.

On the other hand, in order to alleviate the shock at the time of shifting to the slip control, the control output of the feedback control at the start of the slip control is gradually changed according to the driving state of the vehicle before the shift to the slip control. A slip control device that changes the transient output period to be applied has been proposed. For example, the apparatus described in Japanese Patent Application Laid-Open No. Hei 1-206160 is such.

[0005]

However, in the above-described conventional slip control device, a common lock-up clutch is engaged regardless of whether the lock-up clutch is engaged or disengaged before the slip control is executed. Since feedback control is performed using a control formula, it is necessary to perform a complicated transient control in which a transient output period in which the control output is temporarily gradually changed according to the driving state of the vehicle before shifting to the slip control. At the same time, there is a disadvantage that the transient control for gradually changing the control output causes a delay in the control response and the engine tends to blow up.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to suitably start slip control without performing transient control for gradually changing the control output at the start of slip control. An object of the present invention is to provide a slip control device for a lock-up clutch for a vehicle.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a fluid transmission device having a lock-up clutch between a pump impeller and a turbine impeller. When the running state of the vehicle enters the slip control region from the preset engagement region or release region of the lock-up clutch, the slip rotation speed of the lock-up clutch matches a predetermined target slip rotation speed. (A) slip control area determination for determining whether or not the running state of the vehicle has entered the slip control area. Means, and (b) when the slip control area determining means determines that the traveling state of the vehicle has entered the slip control area. That the lock-up clutch
Slip control permitting means for permitting the slip control by the slip control means after passing through the release state .

[0008]

With this configuration, when the slip control area determining means determines that the running state of the vehicle has entered the slip area, the slip control permitting means sets
The slip control by the slip control means is permitted after the lock-up clutch is passed through the released state .

[0009]

As described above, according to the present invention, since the slip control by the slip control means is started after the lock-up clutch is passed through its disengaged state , the slip control is always performed from the same region. The slip control can be suitably started by a certain control formula. Therefore, there is no need for complicated transient control in which the control output is temporarily and gradually changed in accordance with the operating state before the start of the slip control, and there is an inconvenience that engine transients occur due to the transient control. Is also eliminated. Also, according to the present invention, the vehicle state
If it is determined that the lip area has been entered,
Slip control is permitted after the latch is released.
Therefore, lock-in is always performed at the start of slip control.
Since an oil film is formed on the
In a state where the relationship between friction and frictional force does not change much
Control is started and slip control is started more stably.
It is.

[0010]

[0011]

According to another aspect of the present invention, a fluid having a lock-up clutch between a pump impeller and a turbine impeller is provided. In a vehicle having a transmission, when a running state of the vehicle enters a slip control region from a predetermined engagement region or a release region of a lock-up clutch, the slip rotation speed of the lock-up clutch becomes equal to a predetermined target slip rotation speed. A slip control device for a lock-up clutch for a vehicle having a slip control means for performing control so as to match the slip control device, wherein (a) slip control for determining whether or not a running state of the vehicle has entered the slip control region. Area determining means; and (b) determining whether the traveling state of the vehicle has entered the slip control area by the slip control area determining means. To a lock-up clutch engagement state determination means for determining whether the lock-up clutch is either allowed to release and engaged at that time, (c)
The control system used in the slip control unit includes a control system selection unit that selects a different control system according to the engagement state of the lock-up clutch determined by the lock-up clutch engagement state determination unit. .

[0012]

In this way, when the slip control area determining means determines that the traveling state of the vehicle has entered the slip control area, the lock-up clutch engagement state determining means determines whether or not the lock-up clutch at that time is present. It is determined whether it is engaged or released. Then, different control formulas are selected by the control formula selection means according to the engagement state of the lock-up clutch determined by the lock-up clutch engagement state determination means as the control formula used in the slip control means.

[0013]

As described above, according to the present invention, the control system used in the slip control means differs depending on the engagement state of the lock-up clutch determined by the lock-up clutch engagement state determination means. Since the control formula is selected, a control formula for starting the slip control from the released state and a control formula for starting the slip control from the engaged state can be selected, so that the slip control is suitably started. obtain. Therefore, there is no need for complicated transient control in which the control output is temporarily and gradually changed in accordance with the operating state before the start of the slip control, and there is an inconvenience that engine transients occur due to the transient control. Is also eliminated.

[0014] Preferably, the above-mentioned control equation comprises a target slip rotation speed TNSLP and an actual slip rotation speed N.
A proportional term for determining a proportional control amount proportional to the deviation ΔE from the SLP, an integral term for determining an integral control amount according to an integral value of the deviation ΔE, and a differential control amount according to a differential value of the deviation ΔE Including the differential term, at least the differential constant applied to the differential term is different from each other. Also,
Preferably, the differential constant of the control equation used when the slip control is started from the engagement area is set to a value larger than the control equation used when the slip control is started from the release area. In addition, there is an advantage that the control output when the slip control is started from the engagement region tends to be relatively advanced in phase.

[0015]

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 diagram 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 for the engine 1
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
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 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. 4, the forward speeds 4 having different speed ratios I (= rotation speed of input shaft 20 / rotation speed of counter shaft 40) are different from each other.
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 control device of the vehicle. 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 turned on and off by a solenoid 48 to generate a switching signal pressure P _sw, as shown in FIG. 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 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 in accordance with the slip control signal pressure P _SLU output from the LU; It has.

Referring to FIG. 4, a pump 60 for sucking and pumping the hydraulic oil recirculated to a tank (not shown) via 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 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 _Psw from the third solenoid valve S3 is applied to the oil chamber 102, and the spool valve 92 exerts 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.

[0027] 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 is
Second line pressure Pl_TwoIs supplied to the line pressure port 130,
Release-side oil chamber 33 discharged from the second discharge port 88
Port 132 for receiving the hydraulic oil inside, the receiving port
A port for discharging the hydraulic oil received by the port 132
Drain port 134, receiving port 132 and drain port
134 and the hydraulic oil in the release-side oil chamber 33
The engagement side oil chamber 35 and the release side oil chamber
33 pressure difference ΔP (= P_on−P_offThe first to increase)
To the position (left position in FIG. 4) and the receiving port 13
2 and the line pressure port 130 to communicate with the release side oil.
In the chamber 33, the second line pressure Pl_TwoBy supplying the above
Heading to the second position (right position in FIG. 4) for decreasing ΔP
Spool valve 13 provided movably in the direction
6 and its spool valve element 136 toward the first position.
To be able to contact the spool valve element 136
Plunger 138 and the plunger 138
Lip control signal pressure P_SLUTo go to the first position
Signal pressure P for slip control to generate thrust _SLU
To the signal pressure oil chamber 140 and the plunger 138
Oil pressure P in the release side oil chamber 33_offAct on the plunger
138 to the spool valve 136 toward its first position
Oil pressure P to generate thrust_offAccept
And the engagement side oil chamber 35 with the spool valve element 136.
Hydraulic pressure P_onAct on the spool valve element 136 to
Hydraulic pressure P to generate thrust in the direction to the two positions_on
And an oil chamber 144 for receiving oil.
And move the spool valve element 136 toward the second position.
And a biasing spring 146.

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 larger in order from the oil chamber 142 side. the third land 152 and the cross-sectional area a ₁ and the fourth land 154 is the same cross-sectional area is formed is a cross-sectional area a ₃ from the signal pressure oil chamber 140 side. Thus, the plunger 138 is mutually operated integrally in contact with the spool 136 equivalents, the pressure difference ΔP of both sides of the piston 30 size corresponding to the slip control signal pressure P _{SL U} (= P _on -P _off ) is formed. At this time, the pressure difference ΔP is equal to the slip control signal pressure P.
_The slope [(A ₂ −A ₁ ) / A for _SLU by equation 1
₁ ) and changes relatively slowly. Incidentally, in Equation 1, F _s is the biasing force of the spring 146.

[0030]

(Equation 1)

FIG. 6 shows a change characteristic of the pressure difference ΔP obtained by the operation of the lock-up control valve 56 configured as described above with respect to the slip control signal pressure P _SLU . Therefore, the lock-up relay valve 52
Is ON, the slip control signal pressure P _SLU
Becomes larger, the engagement-side oil chamber 35 and the release-side oil chamber 33 are increased.
(P _on -P _off ) is increased, the slip rotation speed NSLP of the lock-up clutch 32 is reduced. On the contrary, the slip control signal pressure P
_{As the SLU} decreases, the slip rotation speed NSLP increases.

[0032] 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
An intake air temperature sensor 164 for detecting the temperature T _AIR of the intake air sucked to zero, a throttle sensor 167 with an idle switch for detecting a fully closed state and an opening TAP of a throttle valve 166 opened / closed by operating an accelerator pedal 165; A vehicle speed sensor 168 for detecting the rotation speed of the output shaft of the automatic transmission 14, that is, a vehicle speed V, a cooling water temperature sensor 170 for detecting a cooling water temperature T _WA of the engine 10, and a brake sensor 17 for detecting that a brake pedal is operated.
2, the operation position of the shift lever 174 P _s That L, S, D, N, R, the operation position sensor 176 for detecting either the P range, the rotational speed N _T i.e. the automatic transmission of the turbine runner 22 A turbine rotational speed sensor 178 for detecting the rotational speed of the input shaft 20 of the oil pressure sensor 14, and an oil temperature sensor 18 for detecting the temperature T _OIL of the hydraulic oil of the hydraulic control circuit 44
0 is provided. 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 includes 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 shift control, a shift diagram corresponding to an actual shift speed is selected from a plurality of shift diagrams previously stored in the ROM, and the running state of the vehicle, for example, the throttle valve opening, is selected from the shift diagram. The transmission gear is determined based on the degree TAP and the vehicle speed V, and the first electromagnetic valve S1 and the second electromagnetic valve S2 are driven so as to obtain the transmission gear. _0, C _1, C
₂ and the operations of the brakes B ₀ , B ₁ , B ₂ , and B ₃ are controlled to establish any one of the four forward speeds.

The engagement control of the lock-up clutch 32 is executed, for example, during traveling at the third speed and the fourth speed. In the engagement control,
Based on the relationship shown in FIG. 7 previously stored in the ROM, based on the running state of the vehicle, for example, the output shaft rotation speed (vehicle speed) _Nout and the throttle valve opening TAP, the release area, the slip control area, and the engagement of the lock-up clutch 32 are determined. It is determined which of the areas is. In this slip control region, the lock-up clutch 32 is maintained in a slip state so as to be connected while absorbing a torque fluctuation 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.
In this case, since the vehicle is in the coasting state where the throttle valve opening TAP is zero, the slip region specified exclusively by the vehicle speed V is used.

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 traveling 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} is calculated and output. Note that the second on the right side of Equation 2 is
The term is a feedforward term for adding an operation amount corresponding to an engine output torque value or the like in order to improve responsiveness.

[0037]

(Equation 2)

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 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 vehicle drive is controlled. controls the second throttle valve 192 by a throttle actuator 190 in order to suppress the power, fuel cut control, on the fuel-cut rotational speed N _cUT to engine rotational speed N _E is set in advance in the coasting in order to improve the fuel efficiency Fuel injection valve 1 only during turning period
Close 86.

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 traveling state of the vehicle enters the predetermined slip control area, the slip control means 196, according to Equation 2 slip speed NSLP of the lock-up clutch 32 (= N _E -N _T) is given Of the target slip rotation speed TNSLP. The slip control area determining means 198 determines whether the running state of the vehicle has entered the slip control area. The slip control permitting means 200 includes a slip control area determining means 198.
When it is determined that the running state of the vehicle has entered the slip range, the lock-up clutch 32 is allowed to pass through its disengaged state, and then the slip control by the slip control means 196 is permitted.

The main part of the control operation of the shift electronic control unit 184 will be described below with reference to the flowchart of FIG.

In FIG. 9, in step SC1 (hereinafter, the steps are omitted) corresponding to the slip control area determining means 198, it is determined whether or not the engagement condition of the lock-up clutch 32 is satisfied. This engagement condition includes that the vehicle state is within the engagement region of FIG. 7, and a negative determination is made when the vehicle enters the slip control region of FIG. If the determination of SC1 is affirmative, S
After the content of the timer counter CLUOFF is cleared to "0" in C2, the lock-up clutch 32 is engaged in SC3. T ₁ in Figure 10 illustrates this point.

If the determination in SC1 is negative, that is, if it is the release area or the slip control area in FIG. 7, "1" is added to the content of the timer counter CLUOFF in SC4. This timer counter CL
UOFF is for counting the time elapsed since the lock-up clutch 32 was released. Next, in SC5 corresponding to the slip control permitting means 200, it is determined whether or not the counted content of the timer counter CLUOFF has reached a predetermined reference value TK. This determination reference value TK is determined by the lock-up clutch 3
This is the minimum value that can ensure that the hydraulic oil is interposed on the surface of No. 2, for example, a value of about 1 second is adopted.

Initially, since the determination at SC5 is negative, the lock-up clutch 32 is released at SC7. That is, the vehicle is released regardless of whether the running state of the vehicle is in the release region or the slip control region in FIG. T ₂ of FIG. 10 illustrates this point.

If the determination at SC5 is affirmative while the above steps are repeatedly executed, it is determined at SC6 whether the slip control start condition is satisfied. For example, when the running state of the vehicle is in the release area, this SC
After the determination of No. 6 is denied, the release of the lock-up clutch 32 is continued in SC7. However, when the running state of the vehicle is in the slip control region, the determination in SC6 is affirmative, and the slip control is performed in SC8 corresponding to the slip control means 196. T ₃ in Figure 10 illustrates this point.

In the slip control of SC8, for example,
From the relationship shown in FIG. 11, the target slip rotation speed TNSLP
Is determined, and the target slip rotation speed TNSLP and the actual slip rotation speed TNSLP are determined.
Control deviation Δ which is the difference from slip rotation speed NSLP
E is calculated sequentially, and its control deviation is calculated from Equation 2.
The drive current I which is the control operation value so that ΔE is eliminated
_SLUThat is, the drive duty ratio DSLU is calculated.
During such slip control, the judgment of SC1 is made.
If affirmative, SC2 and SC3 are executed to lock.
The clutch 32 is engaged. T in FIG._Four
Indicates this point.

As described above, according to this embodiment, when it is determined that the running state of the vehicle has entered the slip region by SC1 corresponding to the slip control region determination unit 198, the slip control permission unit 200 Corresponding SC5
As a result, the lock-up clutch 32 is caused to pass through a predetermined one of the engaged state and the released state, and then the SC8 corresponding to the slip control means 196 is controlled.
Is permitted. For this reason, the slip control can always be started from the same region, so that the slip control can be suitably started by a certain control formula. Therefore, there is no need for complicated transient control in which the control output is temporarily and gradually changed in accordance with the operating state before the start of the slip control, and there is an inconvenience that engine transients occur due to the transient control. Is also eliminated.

Further, according to the present embodiment, the SC 5 corresponding to the slip control permitting means 200 permits the slip control by the SC 8 after passing through the disengaged state of the lock-up clutch 32. Thus, when the slip control is started from the lock-up clutch released state, the slip control is started with the oil film formed on the lock-up clutch surface, so that the relationship between the pressing force and the frictional force changes so much. Since the slip control is started in a state where the slip control is not performed, there is an advantage that the slip control can be more stably executed.

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. 12 is a functional block diagram for explaining main control functions of the electronic control unit 184 for shifting. FIG.
2, when the running state of the vehicle enters a preset slip control region, the slip control means 196 causes the slip rotation speed NSLP (=
N _E -N _T ) is a predetermined target slip rotation speed TNSLP
Control to match. The slip control area determining means 198 determines whether the running state of the vehicle has entered the slip control area. The lock-up clutch engagement state determination unit 206 determines whether the lock-up clutch 32 is engaged when the slip control region determination unit 198 determines that the running state of the vehicle has entered the slip control region. Determine if it has been released. The control type selecting means 208 includes a slip control means 196.
Is selected according to the engagement state of the lock-up clutch determined by the lock-up clutch engagement state determination means 206.

Hereinafter, the electronic control unit 1 for shifting according to the present embodiment will be described.
The main part of the control operation of 84 will be described with reference to the flowchart of FIG.

In FIG. 13, a step SD1 (hereinafter, referred to as step SD1)
Skip the steps. ), Lock-up clutch 3
It is determined whether the second engagement condition is satisfied. This engagement condition includes that the vehicle state is within the engagement region of FIG. 7, and a negative determination is made when the vehicle enters the slip control region of FIG. If the determination in SD1 is affirmative, the lock-up clutch 32 is engaged in SD2.

If the determination in SD1 is negative, that is, if it is the release area or the slip control area in FIG. 7, it is determined whether the slip control start condition is satisfied in SD3 corresponding to the slip control area determination means 198. Is determined. The slip control start condition includes that the running state of the vehicle has entered the slip control region of FIG. If the determination in SD3 is negative, that is, if the running state of the vehicle is not in the slip control region of FIG. 7, the lockup clutch 32 is released in SD4.

However, when the determination in SD3 is affirmative, that is, when the running state of the vehicle is in the slip control region of FIG. It is determined whether the lock-up clutch 32 at that time, that is, before the start of the slip control, is engaged. When the determination in SD5 is denied, that is, when the lock-up clutch 32 is released, the control formula 1 is selected in SD6, but when the determination in SD5 is affirmed, that is, the lock-up clutch 32 is engaged. If so, control equation 2 is selected in SD7. In the present embodiment, SD6 and SD7 correspond to the control formula selecting means 208 for selecting the control formula used for the slip control according to the engagement state of the lock-up clutch 32.

Here, the above control equations 1 and 2 are
It is controlled as shown in Equation 2, but the proportionality constant K _P and differential constant T _D are different from one another. These proportional constants K
_P and derivative constant T _D is set to a value corresponding to the initial condition is set to a large value at least differential constant T _D of controlled 2 is compared with that of the control formula 1. When the slip control is started from the disengaged state of the lock-up clutch 32, the slip is performed with the oil film on the surface of the lock-up clutch 32, whereas the slip control is performed from the engaged state of the lock-up clutch 32. When the lock-up clutch 32 is started, it is slipped without an oil film on the surface of the lock-up clutch 32, so that the relationship between the pressing force of the lock-up clutch 32 and the frictional force is greatly different, and because when the slip control is started in the absence oil film is remarkable phase delay of the control response to, set to a large value differential constant T _D of controlled 2 as described above is compared to that of the control formula 1 As a result, the slip control by the control formula 2 tends to lead the phase.

Next, in SD8 corresponding to the slip control means 196, the same slip control as in SC8 described above is executed by using the control formula selected in SD6 or SD7.

According to the present embodiment, when SD3 corresponding to the slip control area determining means 198 determines that the running state of the vehicle has entered the slip control area, the lockup clutch engagement state determining means 206 corresponds. SD
5, it is determined whether the lock-up clutch 32 at that time is engaged or released.
Then, SD6 and SD7 corresponding to the control type selection means 208 are used to generate the SD corresponding to the slip control means 196.
As a control formula used in step 8, in accordance with the engagement state of the lock-up clutch determined by the above SD5,
Since a different control formula, that is, a control formula 1 for starting the slip control from the disengaged state and a control formula 2 for starting the slip control from the engaged state can be selected, the slip control can be suitably started. Therefore, there is no need for complicated transient control of temporarily and gently changing the control output according to the operating state before the start of the slip control, and
The inconvenience of the engine rising due to the transient control is also eliminated.

According to the present embodiment, the above-mentioned control equations 1 and 2 represent a proportional term for determining a proportional control amount proportional to the deviation ΔE between the target slip rotation speed TNSLP and the actual slip rotation speed NSLP, and the deviation thereof. integral term to determine the integral control amount corresponding to the integral value of Delta] E, includes a derivative term to determine the derivative control amount corresponding to the differential value of the deviation △ E, at least differential constant T _D consuming the derivative term is mutually It is different. Also, preferably, the differential constant T of the control formula 2 used when the slip control is started from the engagement region.
_D is set to a value larger than the control formula 1 used when the slip control is started from the release area, so that the control output when the slip control is started from the engagement area is relatively advanced in phase. There is a trended advantage.

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 the embodiments of FIGS. 8 and 9 described above, the slip control is started only after passing through the disengagement area of the lock-up clutch 32. After that, the slip control may be started. Even in this case, a tentative effect is obtained such that the transient control becomes unnecessary.

Further, the hydraulic control circuit 44 of the above-described embodiment is used.
Was configured as shown in FIG. 4, but other configurations may be used. For example, the lock-up relay valve 52 and the lock-up control valve 56 may be integrally formed.

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 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;

9 is a flowchart illustrating a main part of a control operation of the shift electronic control device in FIG. 3;

FIG. 10 is a time chart illustrating slip control start control related to the acceleration operation speed in the control operation of the shift electronic control device of FIG. 3;

FIG. 11 is a diagram showing a relationship used to determine a target slip rotation speed in the slip control of FIG. 9;

FIG. 12 is a diagram corresponding to FIG. 8 in another embodiment of the present invention.

FIG. 13 is a flowchart illustrating a main part of a control operation in the embodiment of FIG. 12;

[Explanation of symbols]

 10: Engine 32: Lock-up clutch 196: Slip control means 198: Slip control area determination means 200: Slip control permission means 206: Lock-up clutch engagement state determination means 208: Control type selection means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-231530 (JP, A) JP-A-1-206160 (JP, A) JP-A-4-64768 (JP, A) JP-A-4- 60268 (JP, A) JP-A-1-279157 (JP, A) JP-A-7-42825 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-63 / 48

Claims (2)

(57) [Claims] In a vehicle having a fluid transmission device having a lock-up clutch between a pump impeller and a turbine impeller, a running state of the vehicle is controlled from a predetermined engagement area or a release area of the lock-up clutch. A slip control device for a lock-up clutch for a vehicle of a type including a slip control means for controlling a slip rotation speed of the lock-up clutch to be equal to a predetermined target slip rotation speed when entering a slip control region, A slip control area determining means for determining whether or not the running state of the vehicle has entered the slip control area; and if the slip control area determining means determines that the running state of the vehicle has entered the slip area. , the slip control of the lockup clutch from by way of its released state by the slip control means A slip control permitting means for permitting slip lockup clutch control apparatus for a vehicle, which comprises. 2. A vehicle having a fluid transmission having a lock-up clutch between a pump impeller and a turbine impeller, wherein a running state of the vehicle is controlled from a predetermined engagement area or a release area of the lock-up clutch. A slip control device for a lock-up clutch for a vehicle of a type including a slip control means for controlling a slip rotation speed of the lock-up clutch to be equal to a predetermined target slip rotation speed when entering a slip control region, A slip control area determining means for determining whether or not the running state of the vehicle has entered the slip control area; and when the slip control area determining means determines that the running state of the vehicle has entered the slip control area. ,
A lock-up clutch engagement state determining means for determining whether the lock-up clutch at that time is engaged or released; and a lock-up clutch engagement state determination as a control formula used in the slip control means. a controlled selection means for selecting the determined lockup clutch varies controlled depending on the state of engagement by means slip lockup clutch control apparatus for a vehicle, which comprises.