JPH0828682A - Slip control device of lock-up clutch for vehicle - Google Patents

Abstract

PURPOSE:To provide a slip control device of a lock-up clutch for a vehicle capable of preferably starting the slip control without realizing the transient control to gradually change the control output in starting the slip control. CONSTITUTION:When the traveling condition of a vehicle is judged to enter the slip region by a slip control region judging means 198, the slip control by a slip control means 196 is permitted by a slip control permitting means 200 after an lock-up clutch 32 passes the preliminarily determined condition of the engaged condition or the released condition. Because the slip control can be realized constantly from the same region, the slip control is preferably started by the prescribed control formula. Thus, the complicate transient control that the control output is temporarily and gradually changed according to the running condition before the slip control is started can be dispensed with.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a vehicle equipped with a hydraulic transmission with a lockup clutch such as a torque converter with a lockup clutch or a fluid coupling with a lockup clutch, the rotation loss of the lockup clutch is further reduced. For the purpose of improving the fuel consumption of, the slip area is provided between the disengagement area and the engagement area of the lockup clutch, and the actual slip amount, that is, the slip amount, is set so that the lockup clutch is in a semi-engaged state in the slip area It has been proposed to control the difference between the rotational speed of a pump impeller and the rotational speed of a turbine impeller so as to follow a predetermined target slip rotational speed.

Generally, in the above slip control, a hydraulic system capable of guaranteeing the complete engagement of the lockup clutch is used to control the pressure difference between the hydraulic pressures before and after the lockup clutch, and based on the pressure difference. Since the slip force is adjusted by changing the frictional force by the pressing force,
Since the slip amount of the lockup 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 become unstable.

On the other hand, in order to mitigate the shock when shifting to the slip control, the control output of the feedback control at the start of the slip control is gently changed according to the operating state of the vehicle before shifting to the slip control. A slip control device is proposed in which the transient output period to be changed is changed. For example, this is the device described in Japanese Patent Laid-Open No. 1-260160.

[0005]

However, in the above-described conventional slip control device, the common lock-up clutch is common regardless of whether the lock-up clutch is in the disengaged state or the engaged state before the slip control is executed. Since feedback control is performed using a control formula, complicated transient control is required to change the transient output period in which the control output is temporarily and gently changed according to the operating state of the vehicle before shifting to slip control. At the same time, there is a drawback in that the transient control that gently changes the control output causes a delay in the control response and the engine tends to blow up.

The present invention has been made in view of the above circumstances. An object of the present invention is to suitably start slip control without performing transient control for gently 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 vehicle lock-up clutch.

[0007]

A first aspect of the present invention for achieving the above object is to provide a hydraulic power transmission device having a lockup clutch between a pump impeller and a turbine impeller. In a vehicle having, when the running state of the vehicle enters a slip control region from a preset engagement region or release region of the lockup clutch, the slip rotation speed of the lockup clutch matches a predetermined target slip rotation speed. A slip control device for a vehicle lock-up clutch of a type including a slip control means for controlling, wherein: (a) a slip control region determination that determines whether the running state of the vehicle has entered the slip control region Means, and (b) when it is determined by the slip control area determination means that the traveling state of the vehicle has entered the slip control area, Serial and slip control permitting means for permitting the slip control by the slip control means from the by way of the predetermined one of the state of the lock-up clutch that engaged state and released state is to contain.

[0008]

With this configuration, when the slip control area determination means determines that the traveling state of the vehicle has entered the slip area, the slip control permission means determines
The slip control by the slip control means is permitted after the lockup clutch is passed through one of the engagement state and the disengagement state determined in advance.

[0009]

As described above, according to the present invention, after the lockup clutch is made to go through one of the engagement state and the release state, which is determined in advance, slip control by the slip control means is performed. Since the control is started, the slip control can always be entered from the same region, so that the slip control can be suitably started by a constant control formula. Therefore, it is not necessary to perform a complicated transient control in which the control output is temporarily and gently changed according to the operating state before the slip control is started, and the engine is blown up due to the transient control. Is also resolved.

Preferably, the slip control permission means permits the slip control by the slip control means after the lockup clutch is released. With this configuration, when the slip control is started from the lockup clutch released state, the slip control is started in the state where the oil film on the lockup clutch surface is formed. Since the slip control is started in a state where the relationship does not change so much, there is an advantage that the slip control can be executed more stably.

[0011]

A second aspect of the invention for achieving the above object is to provide a fluid having a lock-up clutch between a pump impeller and a turbine impeller. In a vehicle having a transmission, when the running state of the vehicle enters a slip control region from a preset engagement region or release region of the lockup clutch, the slip rotation speed of the lockup clutch becomes a predetermined target slip rotation speed. A slip control device for a vehicle lock-up clutch of a type provided with a slip control means for controlling to match, (a) slip control for determining whether the running state of the vehicle has entered the slip control region Area determination means, and (b) when the slip control area determination means determines that the running state of the vehicle has entered the slip control area. 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 formula used in the slip control unit includes a control formula selection unit that selects a different control formula according to the engagement state of the lockup clutch determined by the lockup clutch engagement state determination unit. .

[0012]

With this configuration, when the slip control area determination means determines that the running state of the vehicle has entered the slip control area, the lockup clutch engagement state determination means determines the lockup clutch at that time. It is determined whether engaged or disengaged. Then, the control formula selection means selects a different control formula as the control formula used in the slip control means according to the engagement state of the lockup clutch determined by the lockup clutch engagement state determination means.

[0013]

As described above, according to the present invention, the control formula used in the slip control means differs depending on the engagement state of the lockup clutch determined by the lockup clutch engagement state determination means. Since the control formula is selected, the control formula for starting the slip control from the disengaged state and the control formula for starting the slip control from the engaged state can be selected, so that the slip control is preferably started. obtain. Therefore, it is not necessary to perform a complicated transient control in which the control output is temporarily and gently changed according to the operating state before the slip control is started, and the engine is blown up due to the transient control. Is also resolved.

[0014] Here, preferably, the above control formula is based on the target slip rotation speed TNSLP and the 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. The differential constant is included, and at least the differential constants applied by the differential term are different from each other. Also,
Preferably, the differential constant of the control formula used when the slip control is started from the engagement region is set to a value larger than the control formula used when the slip control is started from the release region. The control output when the slip control is started from the engagement region has an advantage that the phase is relatively advanced.

[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 view of a vehicle power transmission device to which an embodiment of the present invention is applied. In the figure, the power of the engine 10 is transmitted to a differential gear unit and drive wheels (not shown) through a torque converter 12 with a lockup clutch, a stepped automatic transmission 14 including three sets of planetary gear units, and the like. It is like this.

The torque converter 12 is the engine 1
Is connected to the crankshaft 16 of 0 and has a cross section U at the outer peripheral portion.
A pump impeller 18 having a blade that is bent in a letter shape and that generates a flow of hydraulic oil having a directional component toward the engine 10 side, and is fixed to the input shaft 20 of the automatic transmission 14, Has a blade facing the blade of
A turbine impeller 22 that is rotated by receiving oil from the blades of the pump impeller 18, a stator impeller 28 fixed to a housing 26 that is a non-rotating member via a one-way clutch 24, and an axial movement The lock-up clutch 32 is connected to the input shaft 20 via a piston 30 fitted to the hub portion of the turbine impeller 22 so as to be rotatable relative to the shaft.

In the torque converter 12, the oil pressure in the release side oil chamber 33 among the engagement side oil chamber 35 and the release side oil chamber 33 divided by the piston 30 is increased and the inside of the engagement side oil chamber 35 is increased. When the hydraulic pressure is released, the piston 3
Since 0 is retracted and the lockup clutch 32 is disengaged, torque is transmitted at an amplification factor according to the input / output rotation speed ratio of the torque converter 12. But,
The oil pressure in the engagement side oil chamber 35 is increased and the release side oil chamber 33
When the internal hydraulic pressure reaches the minimum pressure, the piston 30 is advanced and the lock-up clutch 32 is pressed by the pump impeller 18 and brought into the engaged state. Therefore, the torque converter 1
The two input / output members, that is, the crank shaft 16 and the input shaft 20 are directly connected.

The automatic transmission 14 has three coaxially arranged parts.
Set of single pinion type planetary gear units 34, 36, 38
And a counter shaft (output shaft) 40 that transmits power between the input shaft 20, an output gear 39 that rotates together 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} . In addition, the planetary gear device 34,
Some of the components of 36, 38 include four brakes B ₀ ,
B _1, B _2, B with ₃ is selectively connected to the housing 26 by a further, mutually or housing by the rotation direction of some of the components by the three-way clutches F _0, F _1, F ₂ It is designed to be engaged with 26.

The clutches C ₀ , C ₁ and C ₂ and the brakes B ₀ , B ₁ , B ₂ and B ₃ are provided with, for example, a multi-plate type clutch or one band or two bands having opposite winding directions. 2 is constituted by band brakes and the like, each of which is operated by a hydraulic actuator, and the operation of each of these hydraulic actuators is controlled by an electronic control unit 184 for shifting, which will be 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) ”
Represent the first speed gear, the second speed gear, the third speed gear, and the fourth speed gear on the forward side, respectively, and the above gear ratio changes from the first speed gear to the fourth speed gear. It becomes smaller as you go. 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 structure of the vehicle control device. In the figure, a hydraulic control circuit 44 includes a shift control hydraulic control circuit for controlling the gear stage of the automatic transmission 14 and a lockup clutch control hydraulic control for controlling engagement of the lockup clutch 32. And a circuit are provided. As is well known, the hydraulic control circuit for gear shift control includes a first solenoid valve S1 and a second solenoid valve S2 that are turned on and off by a solenoid No. 1 and a solenoid No. 2, respectively. Valve S1
2 and the combination of the operations of the second solenoid valve S2.
As shown in FIG. 5, the clutch and the brake are selectively operated to establish any one of the first to fourth speed gear stages.

The lockup clutch control hydraulic control circuit, as shown in FIG. 4, for example, is a third solenoid valve S3 which is turned on / off by a solenoid 48 to generate a switching signal pressure P _sw , and its switching. A lockup relay valve 52 that can be switched between a disengagement side position where the lockup clutch 32 is disengaged and an engagement side position where the lockup clutch 32 is engaged according to the use signal pressure P _sw.
And 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 unit 184, and a linear solenoid valve S
A lockup control control valve 56 for controlling the slip amount of the lockup clutch 32 by adjusting the pressure difference ΔP between the engagement side oil chamber 35 and the disengagement side oil chamber 33 in accordance with the slip control signal pressure P _SLU output from the LU. Is equipped with.

In FIG. 4, a pump 60 for sucking the hydraulic oil, which has flowed back into a tank (not shown), through a strainer 58 and sending it under pressure is rotationally driven by the engine 10. The operating oil pressure fed from the pump 60 is firstly fed to the first type by an overflow type first pressure regulating valve 62.
The pressure is adjusted to the line pressure Pl ₁ . This first
The pressure regulating valve 62 generates a first line pressure Pl ₁ that increases corresponding to the throttle pressure output from a throttle valve opening detection valve (not shown), and outputs it via a first line oil passage 64. The second pressure regulating valve 66 is an overflow type pressure regulating valve, and regulates the hydraulic oil that has flowed out from the first pressure regulating valve 62 based on the throttle pressure, so that the second pressure regulating valve 66 corresponds to the output torque of the engine 10. Generate a line pressure Pl ₂ . The third pressure regulating valve 68 is a pressure reducing valve whose source pressure is the first line pressure Pl ₁ and generates a constant third line pressure Pl ₃ . Further, the manual valve 70 generates the R range pressure P _R when the shift operation lever 174 is in the R range. Then, the OR valve 72 operates at a pressure P that operates the brake B ₂ that is engaged when the second speed gear or higher is reached.
_The higher one of _B2 and the R range pressure P _R is selected and output.

The lock-up relay valve 52 has a release side port 80 communicating with the release side oil chamber 33 and an engagement side oil chamber 35.
An engagement side port 82 communicating with the input side port 84 to which the second line pressure Pl ₂ is supplied, a first discharge port 86 from which hydraulic oil in the engagement side oil chamber 35 is discharged when the lockup clutch 32 is released, The second discharge port 8 from which the hydraulic oil in the release side oil chamber 33 is discharged when the lockup clutch 32 is engaged.
8. A supply port 90 to which a part of the hydraulic oil discharged from the second pressure regulating valve 66 is supplied for cooling during the engagement period of the lockup clutch 32, and a spool valve element 92 for switching the connection state of these ports. A spring 94 for urging the spool valve element 92 toward the off-side position, a plunger 96 arranged so as to be capable of contacting the spring 94 side end portion of the spool valve element 92, and the spool valve element 92 and the plunger. 96, an oil chamber 98 provided between the end surface of the plunger 96 and the plunger 9 for applying the R range pressure P _R
The oil chamber 100 that receives the first line pressure Pl ₁ that acts on the end surface of 6 and the third solenoid valve S3 on the end surface of the spool valve element 92.
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 has its spherical valve block the communication between the oil chamber 102 and the OR valve 72 and makes the oil chamber 102 a drain pressure. In the ON state), the oil chamber 102 and the OR valve 72 are made to communicate with each other, and the switching signal pressure P _sw is applied to the oil chamber 102. Therefore, 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 acts as the biasing force of the spring 94. The input port 84 and the release side port 80 are made to communicate with each other, and the engagement side port 82 and the first discharge port 86 are made to communicate with each other because they are located at the off-side position according to the first line pressure Pl ₁ acting on the oil chamber 100. Therefore, the oil pressure P _off in the disengagement side oil chamber 33 is made higher than the oil pressure P _on in the engagement side oil chamber 35 to release the lockup clutch 32, and at the same time, the hydraulic oil in the engagement side oil chamber 35 is released. Is discharged to the drain through 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 biases the spring 94. And the first line pressure P acting on the oil chamber 100
The input port 84 and the engagement side port 82, the release side port 80 and the second discharge port 88, and the supply port 90 and the first discharge port 86 communicate with each other because they are located at the ON side position against L _1. Therefore, the oil pressure P _on in the engagement side oil chamber 35 is made higher than the oil pressure P _off in the disengagement side oil chamber 33 to engage the lockup clutch 32, and at the same time the disengagement side oil chamber 33 The hydraulic oil is the second discharge port 8 described above.
8 and the lock-up control valve 56 to the drain.

The linear solenoid valve SLU is a pressure reducing valve whose source pressure is a constant third line pressure Pl ₃ generated by the third pressure regulating valve 68, and as shown in FIG. The slip control signal pressure P _SLU that increases with the drive current I _SLU (that is, the drive duty ratio DSLU) from is generated, and this slip control signal pressure P _{SLU is applied} to the lockup 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 for outputting a slip control signal pressure P _SLU , a spool valve 114 for opening and closing them, and a spool valve 114 thereof. A spring 115 for urging the spool valve 114 in the valve opening direction, a spring 116 for urging the spool valve 114 in the valve opening direction with a smaller thrust than the spring 115, and a spool valve 114 for the valve opening direction according to the drive current I _SLU . An electromagnetic solenoid 118 for biasing the slip control and an oil chamber 120 for receiving a feedback pressure (a signal pressure P _SLU for slip control) for generating thrust in the valve closing direction in the spool valve 114 are provided. 114 is an electromagnetic solenoid 1
The biasing force of the valve 18 and the spring 116 in the valve opening direction and the biasing force of the spring 115 and the feedback pressure in the valve closing direction are balanced.

The lockup control valve 56 is
Second line pressure Pl₂Is supplied to the line pressure port 130,
Release-side oil chamber 33 discharged from the second discharge port 88
Receiving port 132 for receiving the hydraulic oil in the
For discharging the hydraulic oil received in the port 132.
Len port 134, receiving port 132 and drain port
And the hydraulic oil in the release side oil chamber 33 is communicated.
The engagement side oil chamber 35 and the release side oil chamber can be discharged.
33 pressure difference ΔP (= P_on−P_off) Increase first
Toward the position (left side position in FIG. 4) and the receiving port 13
2 and the line pressure port 130 communicate with each other to release the oil on the release side.
In the chamber 33, the second line pressure Pl₂By supplying
Toward the second position (right side position in FIG. 4) that decreases ΔP
Spool valve 13 provided to be movable in the direction
6 and its spool valve element 136 toward the first position.
Arranged so that it can abut against its spool valve 136 for biasing
The plunger 138 and the plunger 138
Lip control signal pressure P_SLUTo move to the first position
Slip control signal pressure P 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 with spool valve 136 towards its first position
Its hydraulic pressure P in order to generate thrust in the opposite direction_offAccept
Oil chamber 142 that engages with the spool valve element 136.
Oil pressure P in_onThe spool valve element 136 to
The hydraulic pressure P to generate thrust in the direction toward the 2 position_on
And an oil chamber 144 that receives
The spool valve 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 cross-sectional areas A ₁ and A ₂ which increase in order from the oil chamber 142 side, and a spool valve element 136. A _third land 152 having a cross-sectional area A ₃ and a fourth land 154 having the same cross-sectional area as the above-mentioned cross-sectional area A ₁ are formed on the side from the signal pressure oil chamber 140 side. Therefore, the plunger 138 abuts the spool valve 136 and operates integrally with each other, and the pressure difference ΔP (= P _on −P) _on both sides of the piston 30 is the magnitude corresponding to the slip control signal pressure P _{SL U. off} ) is formed. At this time, the pressure difference ΔP is the slip control signal pressure P.
_Slope [(A ₂ −A ₁ ) / A
₁ ), it changes relatively slowly. In Formula 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 lockup control valve 56 constructed as described above with respect to the slip control signal pressure P _SLU . Therefore, the lockup relay valve 52
Is ON, the slip control signal pressure P _SLU
The engagement side oil chamber 35 and the release side oil chamber 33
Since the pressure difference ΔP (P _on −P _off ) between the lockup clutch 32 and the lockup clutch 32 becomes large, the slip rotation speed NSLP of the lockup clutch 32 is reduced.
_{When the SLU} becomes lower, the slip rotation speed NSLP is increased.

Returning to FIG. 3, the vehicle has an engine rotation speed sensor 160 for detecting the rotation speed N _E of the engine 10, that is, the rotation speed N _P of the pump impeller 18, intake air drawn 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 a temperature T _{AIR of} intake air taken into 0, a throttle sensor 167 with an idle switch for detecting a fully closed state and an opening TAP of a throttle valve 166 opened and closed by operating an accelerator pedal 165, A vehicle speed sensor 168 that detects the rotational speed of the output shaft of the automatic transmission 14, that is, the vehicle speed V, a cooling water temperature sensor 170 that detects the cooling water temperature T _WA of the engine 10, and a brake sensor 17 that detects that the brake pedal has been operated.
2. An operation position sensor 176 for detecting the operation position P _s of the shift operation lever 174, that is, one of the L, S, D, N, R, and P ranges, the rotational speed N _T of the turbine impeller 22, that is, the automatic transmission. Turbine rotation speed sensor 178 for detecting the rotation speed of the input shaft 20 of 14, and 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 above sensors are directly or indirectly supplied to the electronic control unit 182 for the engine and the electronic control unit 184 for the shift. The electronic control unit 182 for the engine and the electronic control unit 184 for shifting are interconnected via a communication interface, and input signals and the like are supplied to each other as necessary.

The electronic control unit 184 for shifting is a CPU, R
The CPU is a so-called microcomputer including an OM, a RAM, an interface, etc., and its CPU uses the temporary storage function of the RAM to process an input signal in accordance with a program stored in advance in the ROM, and controls the shift of the automatic transmission 14 and The engagement control of the lockup clutch 32 is executed according to a main routine (not shown), and the first solenoid valve S
The first solenoid valve S2, the third solenoid valve S3, and the linear solenoid valve SLU are controlled.

In the above shift control, a shift diagram corresponding to an actual shift gear is selected from a plurality of types of shift diagrams stored in advance in the ROM, and the running state of the vehicle, for example, the throttle valve opening is selected from the shift diagram. The shift gear is determined based on the degree TAP and the vehicle speed V, and the first solenoid valve S1 and the second solenoid valve S2 are driven to obtain the shift gear, whereby the clutch C of the automatic transmission 14 is driven. ₀ , C ₁ , C
₂ and the brakes B ₀ , B ₁ , B ₂ , and B ₃ are controlled so that any one of the four forward gears is established.

The engagement control of the lockup clutch 32 is executed, for example, during traveling in the third speed gear and the fourth speed gear. In the engagement control,
From the relationship shown in FIG. 7 stored in advance in the ROM, the release area, the slip control area, and the engagement of the lockup clutch 32 are determined based on the running state of the vehicle, for example, the output shaft rotation speed (vehicle speed) N _out and the throttle valve opening TAP. It is determined which one of the areas. In this slip control region, the lockup clutch 32 is maintained in a slip state so that the lockup clutch 32 is coupled while absorbing torque fluctuations of the engine 10 for the purpose of improving fuel economy as much as possible without impairing drivability. FIG. 7 is used during acceleration of the vehicle. Even during deceleration coasting of the vehicle, slip control of the lockup clutch 32 is executed for the purpose of expanding the control range of the fuel cut control.
In this case, since the throttle valve opening TAP is zero and the vehicle is coasting, the slip region specified by the vehicle speed V is used exclusively.

When it is determined that the running state of the vehicle is within the engagement region, the third solenoid valve S3 is excited and the lockup relay valve 52 is turned on, and at the same time the linear solenoid valve SLU is driven. Since the current I _SLU is set to the minimum drive current (rated value), the lockup clutch 32 is engaged. Further, when it is determined that the traveling state of the vehicle is within the release region, the third solenoid valve S3 is de-energized and the lockup relay valve 52 is turned off. Therefore, the drive current for the linear solenoid valve SLU is increased. The lockup clutch 32 is released regardless of I _SLU . When it is determined that the running state of the vehicle is within the slip control range, the third solenoid valve S3 is excited and the lockup relay valve 52 is turned on, and at the same time, the drive current for the linear solenoid valve SLU is increased. I _SLU
Is adjusted in accordance with Equation 2, for example. 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) so that the drive current I
_{The SLU} is calculated and output. In addition, the second side of the right side of Equation 2
The term is a feedforward term for adding a manipulated variable having a magnitude corresponding to the engine output torque value or the like in order to improve the responsiveness.

[0037]

[Equation 2]

An electronic control unit 182 for the engine is also provided.
Is a microcomputer similar to the electronic control unit 184 for gear shifting, and its CPU executes various engine controls by processing an input signal according to a program stored in ROM in advance. For example, the fuel injection amount control controls the fuel injection valve 186 in order to optimize the combustion state, the ignition timing control controls the igniter 188 in order to adjust the retard amount appropriately, and the traction control drives the vehicle. The second throttle valve 192 is controlled by the throttle actuator 190 in order to suppress the force, and in the fuel cut control, the engine rotation speed N _E is set to a preset fuel cut rotation speed N _CUT in coasting to increase fuel consumption. Fuel injection valve 1 only for turning period
Close 86.

FIG. 8 is a functional block diagram for explaining the main part of the control function of the electronic shift control device 184. In FIG. 8, 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 ) of the lockup clutch 32 to be predetermined according to Equation 2. The target slip rotation speed TNSLP is controlled so as to match. The slip control area determination means 198 determines whether the running state of the vehicle has entered the slip control area. The slip control permission means 200 has its slip control area determination means 198.
When it is determined that the traveling state of the vehicle has entered the slip region, the slip control means 196 permits the slip control after the lockup clutch 32 is released.

Below, an explanation will be given of the main part of the control operation of the electronic control unit 184 for gear shifting with reference to the flow chart of FIG.

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

If the determination at SC1 is negative, that is, if it is in 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 elapsed time after the lockup clutch 32 is released. Next, in SC5 corresponding to the slip control permission means 200, it is determined whether or not the count content of the timer counter CLUOFF has reached a preset determination reference value TK. This judgment reference value TK is determined by the lockup clutch 3
It is a minimum value that allows the hydraulic oil to be reliably interposed on the surface of No. 2, and a value of, for example, about 1 second is adopted.

Initially, the determination at SC5 is denied, so the lockup clutch 32 is released at SC7. That is, the vehicle is released regardless of whether the traveling state of the vehicle is in the release area of FIG. 7 or the slip control area. The point t _{2 in} FIG. 10 indicates this point.

If the determination at SC5 is affirmative while the above steps are repeatedly executed, at SC6 it is determined whether or not 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 lockup clutch 32 is continued at SC7. However, when the traveling state of the vehicle is in the slip control region, the determination at SC6 is affirmative, so that the slip control is executed at SC8 corresponding to the slip control means 196. T _{3 in} FIG. 10 indicates this point.

In this 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 actual
Control deviation Δ which is the difference from the slip rotation speed NSLP at the time
E is successively calculated, and the control deviation from Eq.
Drive current I which is a control operation value so that ΔE is eliminated
_SLUThat is, the drive duty ratio DSLU is calculated.
Then, during such slip control, the judgment of SC1 is performed.
Affirmative, SC2 and SC3 are executed and the lock
The up clutch 32 is engaged. T in FIG._Four
Indicates this point.

As described above, according to the present embodiment, when it is determined by SC1 corresponding to the slip control area determination means 198 that the running state of the vehicle is within the slip area, the slip control permission means 200 is notified. Corresponding SC5
As a result, the lockup clutch 32 is caused to go through one of the engagement state and the release state, which is determined in advance, and then SC8 corresponding to the slip control means 196.
The slip control by is permitted. Therefore, the slip control can always be entered from the same region, so that the slip control can be suitably started by a constant control formula. Therefore, it is not necessary to perform a complicated transient control in which the control output is temporarily and gently changed according to the operating state before the slip control is started, and the engine is blown up due to the transient control. Is also resolved.

Further, according to this embodiment, the SC5 corresponding to the slip control permission means 200 permits the slip control by the SC8 after the lockup clutch 32 is released. In this way, when slip control is started from the lockup clutch released state, slip control is started with the oil film formed on the lockup clutch surface, so the relationship between pressing force and frictional force changes significantly. Since the slip control is started in the state where the slip control is not performed, there is an advantage that the slip control can be executed more stably.

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 designated by the same reference numerals, and the description will be omitted.

FIG. 12 is a functional block diagram for explaining the main part of the control function of the electronic shift control device 184. FIG.
In 2, the slip control means 196 causes the slip rotation speed NSLP (=) of the lockup clutch 32 when the running state of the vehicle enters the preset slip control region.
N _E −N _T ) is a predetermined target slip rotation speed TNSLP
Control to match. The slip control area determination means 198 determines whether the running state of the vehicle has entered the slip control area. When the slip control area determination means 198 determines that the running state of the vehicle has entered the slip control area, the lock-up clutch engagement state determination means 206 engages the lock-up clutch 32 at that time. Determine if it has been released. The control type selection means 208 is a slip control means 196.
As the control formula used in, the different control formula is selected according to the engagement state of the lockup clutch determined by the lockup clutch engagement state determination means 206.

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

In FIG. 13, step SD1 (hereinafter,
Skip steps. ), Lockup clutch 3
It is determined whether the engagement condition 2 is satisfied. This engagement condition includes that the vehicle state is within the engagement area of FIG. 7, and a negative determination is made when the vehicle enters the slip control area of FIG. 7. If the determination in SD1 is affirmative, the lockup clutch 32 is engaged in SD2.

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

However, if the determination in SD3 is affirmative, that is, if the running state of the vehicle is within the slip control region of FIG. 7, in SD5 corresponding to the lockup clutch engagement state determination means 206, At this time, that is, before the slip control is started, it is determined whether or not the lockup clutch 32 is engaged. When the determination of SD5 is denied, that is, when the lockup clutch 32 is released, the control formula 1 is selected in SD6, but when the determination of SD5 is affirmed, that is, the lockup clutch 32 is engaged. If so, control formula 2 is selected in SD7. In this embodiment, SD6 and SD7 correspond to the control formula selecting means 208 for selecting the control formula used for slip control according to the engagement state of the lockup clutch 32.

Here, the above control equation 1 and control equation 2 are
Although it is the control formula shown in Formula 2, the proportional constant K _P and the differential constant T _D are different from each other. These proportional constants K
_P and the differential constant T _D are set to values corresponding to the initial conditions, and at least the differential constant T _D of the control equation 2 is set to a larger value than that of the control equation 1. When the slip control is started from the released state of the lockup clutch 32, the slipup is performed with the oil film on the surface of the lockup clutch 32, whereas the slip control is performed from the engaged state of the lockup clutch 32. When the lock-up clutch 32 is started, the surface of the lock-up clutch 32 is slipped without an oil film, so that the relationship of the frictional force with respect to the pressing force of the lock-up clutch 32 is significantly different, and When the slip control is started in the absence of an oil film on the surface, the phase delay of the control response is remarkable, so that the differential constant T _D of the control equation 2 is set to a value larger than that of the control equation 1 as described above. As a result, the slip control by the control formula 2 tends to lead the phase.

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

According to this embodiment, when it is determined by SD3 corresponding to the slip control area determination means 198 that the running state of the vehicle is in the slip control area, the lockup clutch engagement state determination means 206 is handled. SD to do
5, it is determined whether the lockup clutch 32 at that time is engaged or disengaged.
Then, by SD6 and SD7 corresponding to the control type selection means 208, SD corresponding to the slip control means 196.
As a control formula used in No. 8, according to the engagement state of the lockup clutch determined by SD5,
Since different control formulas, that is, the control formula 1 for starting the slip control from the released state and the control formula 2 for starting the slip control from the engaged state can be selected, the slip control can be suitably started. Therefore, the complicated transient control of temporarily and gently changing the control output according to the operating state before the start of the slip control is not required, and
The inconvenience that the engine is blown up due to the transient control is also eliminated.

According to the present embodiment, the control expressions 1 and 2 are proportional terms 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 their deviations. An integral term for determining an integral control amount according to an integral value of ΔE and a differential term for determining a differential control amount according to a differential value of its deviation ΔE are included, and at least differential constants T _D multiplied by the differential term are mutually It is supposed to be different. Further, it is preferable that the differential constant T of the control equation 2 used when the slip control is started from the engagement region.
_{Since D} is set to a value larger than the control formula 1 used when slip control is started from the disengagement region, the control output when slip control is started from the engagement region is relatively advanced in phase. There is a trended advantage.

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

For example, in the embodiments shown in FIGS. 8 and 9, the slip control is always started after the lock-up clutch 32 is disengaged. However, the slip control is always started. It does not matter if the slip control is started after that. Even in this case, a temporary effect such as the need for transient control is obtained.

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

Further, although the torque converter 12 with the direct coupling clutch has been described in the above embodiment,
It may be a fluid coupling with a direct coupling clutch.
In short, any fluid type transmission device having a direct coupling clutch may be used.

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

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing an automatic transmission including the torque converter with a lockup clutch of FIG.
It is a chart explaining the relationship between the combination of the operation of the solenoid valve and the shift speed obtained thereby.

FIG. 3 is a block diagram illustrating a configuration of a control device included in the vehicle of FIG.

FIG. 4 is a diagram illustrating a configuration of a main part of the hydraulic control circuit of FIG.

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

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.

7 is stored in the electronic shift control device of FIG. 3,
It is a figure which shows the relationship between the running state of a vehicle and the engagement state of a lockup clutch.

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

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

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

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 view corresponding to FIG. 8 in another embodiment of the present invention.

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

[Explanation of symbols]

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

Claims (3)

[Claims] 1. A vehicle having a fluid transmission device having a lock-up clutch between a pump impeller and a turbine impeller, wherein a running state of the vehicle is set from an engagement region or a release region of a lock-up clutch in which a preset traveling condition is set. A slip control device for a vehicle lock-up clutch of the type including slip control means for controlling the slip rotation speed of the lock-up clutch so as to match a predetermined target slip rotation speed when entering the slip control region, 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 running state of the vehicle has been determined by the slip control area determining means to be in the slip control area The lockup clutch in one of the engagement state and the release state, which is a predetermined state. Slip lockup clutch control apparatus for a vehicle which comprises a slip control permitting means for permitting the slip control by the slip control means from the by. 2. The slip control device for a vehicle lock-up clutch according to claim 1, wherein the slip control permission means starts slip control by the slip control means after the release state of the lock-up clutch is passed. . 3. 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 set from an engagement region or a release region of the lock-up clutch in which the traveling condition is preset. A slip control device for a vehicle lock-up clutch of the type including slip control means for controlling the slip rotation speed of the lock-up clutch so as to match a predetermined target slip rotation speed when entering the slip control region, 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 running state of the vehicle has been determined by the slip control area determining means to be in the slip control area ,
Lockup clutch engagement state determination means for determining whether the lockup clutch is engaged or released at that time, and the lockup clutch engagement state determination as a control formula used in the slip control means. And a control formula selecting unit that selects different control formulas according to the engagement state of the lockup clutch determined by the means, and a slip control device for a vehicle lockup clutch.