JP3131920B2 - Lockup control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lock-up control device for controlling the operation of a lock-up mechanism of an automatic transmission and the engagement capacity of a lock-up clutch.

[0002]

2. Description of the Related Art Normally, a lock-up clutch of an automatic transmission is engaged at a high gear, that is, at a third gear or a fourth gear. However, the lock-up clutch is engaged at a second gear to improve fuel efficiency. A lock-up control device for controlling the lock-up is conventionally known (JP-A-63-47561).

Further, a target value corresponding to the operating state of the slip amount of the lock-up clutch is stored in a storage device corresponding to the shift speed, and the engagement capacity of the lock-up clutch is set so that the slip amount becomes the target value. Control and
A control in which the engagement capacity control amount is learned in a specific operation state and the learned value is stored in a storage device, and the stored learning value is used as an initial value of the engagement capacity control amount immediately after shifting to the specific operation state ( So-called learning control) has been conventionally performed.

[0004]

However, even when the lock-up clutch is engaged even at the second speed as disclosed in Japanese Patent Application Laid-Open No. 63-47561, the target value and learning value for the second speed are also required. If the values are stored, there is a problem that the capacity of the storage device of the control device is increased and the cost is increased.

The present invention has been made in view of this point, and it is possible to perform lock-up control at a low speed stage without impairing drivability while suppressing an increase in the capacity of a storage device. It is an object to provide a control device.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a lock-up clutch for an automatic transmission in which the slip amount of the lock-up clutch is set to a predetermined target value in accordance with the driving state of the vehicle. In the automatic transmission lock-up control device provided with an area for controlling the engagement capacity, the engagement capacity control amount during the engagement capacity control of the lock-up clutch is learned during traveling at a predetermined gear (third speed) in the area. And a storage unit for storing a learning value (LREFFB3) learned by the learning unit. When the vehicle travels at a speed (second speed) lower than the predetermined speed in the area, the storage means The learning value (LREFFB3) stored in the engine load (T)
HW), the engagement capacity of the lock-up clutch is controlled using the engagement capacity control amount calculated by correcting the engine load to increase as the engine load increases (S164, S82 to S85). And a lock-up control device for an automatic transmission.

According to the present invention, a learning value of the control amount of the engagement capacity of the lock-up clutch is calculated and stored at the time of traveling at a predetermined speed, and the learning value is obtained at the time of traveling at a speed lower than the predetermined speed. Is corrected according to the engine load, and is used for controlling the engagement capacity of the lock-up clutch.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an automatic transmission mounted on a vehicle according to an embodiment of the present invention and a control device therefor. An automatic transmission 21 is connected to a crankshaft 20 of the internal combustion engine 1. Have been. The automatic transmission 21 is connected to the crankshaft 20, and the pump blade 22 a and the turbine blade 2
2b and a pump blade 22a
-Up clutch 23 for connecting the turbine blades 22b to the turbine blades, a gear mechanism 24 connected to the output side of the torque converter 22, and a hydraulic control mechanism 25 for controlling the operations of the lock-up clutch 23 and the gear mechanism 24. Have.

The hydraulic control mechanism 25 includes an on / off type solenoid valve (hereinafter referred to as an "A solenoid valve") 25a for switching engagement / disengagement of the lock-up clutch 23;
A duty control type solenoid valve (hereinafter referred to as “B solenoid valve”) 25b for controlling an engagement pressure (engagement capacity) when the lock-up clutch 23 is in an engaged state with the solenoid valve 25a turned on, and a gear mechanism 24 And a shift actuator 25c for controlling the gear position (gear ratio) of the transmission. A solenoid valve 25a, B solenoid valve 25
b and a shift actuator 25c are an electronic control unit (hereinafter referred to as “ECU”) for controlling an automatic transmission.
The ECU 2 is connected to the A solenoid valve 25a.
And the engagement state of the lock-up clutch 23 is controlled via the B solenoid valve 25b, and the gear position (gear position) of the gear mechanism 24 is controlled via the shift actuator 25c.

The automatic transmission 21 is provided with a gear position sensor 27 for detecting a gear position NGRAT of the gear mechanism 24, and a detection signal is supplied to the ECU 2.

The output of the engine 1 is transmitted from the crankshaft 20 to the left and right driving wheels 32 and 33 via the torque converter 22, the gear mechanism 24 and the differential device 31 in order, and drives them. A vehicle speed sensor 28 for detecting a vehicle speed VP of the vehicle is provided on the output side of the automatic transmission 21, and a detection signal thereof is supplied to the ECU 2.

The engine 1 includes a throttle valve opening sensor 3 for detecting an opening THW of a throttle valve (not shown) provided in the middle of an intake pipe, an engine water temperature sensor 4 for detecting an engine cooling water temperature TW. An engine speed sensor 5 for detecting the engine speed NE is provided, and detection signals from these sensors are supplied to the ECU 2. The engine speed sensor 5 outputs a TDC signal pulse at a predetermined crank angle position every time the crankshaft 20 rotates 180 °,
Supply to ECU2.

A shift position sensor 29 for detecting a shift lever position (hereinafter referred to as a "shift position") for selecting an operation mode of the automatic transmission is connected to the ECU 2, and a detection signal is supplied to the ECU 2. You. In the present embodiment, a D4 range in which a gear position is automatically selected in a range from 1st to 4th speed and a D3 range in which a gear position is automatically selected in a range from 1st to 3rd speed are set as drive ranges. Are provided.

The ECU 2 is connected to an engine control electronic control unit (not shown) for controlling the amount of fuel supplied to the engine 1 (opening time of the fuel injection valve) and the ignition timing, and exchanges control parameter information with each other. It is configured to transmit to.

The ECU 2 has an input circuit having a function of shaping input signal waveforms from the above-described various sensors, correcting a voltage level to a predetermined level, converting an analog signal value to a digital signal value, and the like, and a central processing circuit. (CPU), a storage circuit including a ROM and a RAM for storing various arithmetic programs executed by the CPU, various maps to be described later, arithmetic results, and the like, and drive to an A solenoid valve 25a, a B solenoid valve 25b, and a shift actuator 25c. An output circuit that outputs a signal, and controls the engagement state of the lock-up clutch 23 and the gear position based on detection signals from various sensors. The processing described below with reference to the flowchart is executed by the CPU of the ECU 2.

FIGS. 2 and 3 are flowcharts of a process for controlling the A solenoid valve 25a, and this process is executed every predetermined time (for example, 80 msec). The lock-up clutch 23 is engaged / disengaged in accordance with ON / OFF of the A solenoid valve 25a.

First, in step S1, it is determined whether or not abnormality of the various sensors is detected. If not, it is determined whether or not the engine water temperature TW is higher than a predetermined water temperature TWLC0 (for example, 30 ° C.) ( Step S2).
And, when an abnormality of the sensor is detected or TW ≦ T
If it is WLC0, the down count timer tmDL
A predetermined time TDLY0 is set to Y0 (see step S14) and started (step S13), and a lock-up flag FLCS indicating "1" indicating that the lock-up clutch 23 is engaged is set to "0". Then, the A solenoid valve 25a is turned off (FIG. 3, step S36), and the process is terminated.

If TW> TWLC0 in step S2, it is determined whether or not a downhill flag FBK indicating "1" that the vehicle is traveling on a downhill road is "1" (step S3). If the vehicle is traveling on a slope, the process proceeds to step S4.
When the engine speed NE is equal to the predetermined speed NLCBK (for example, 8
60 rpm) is determined. And NE
If ≦ NLCBK, the process proceeds to step S13 to turn off the A solenoid valve 25a, and NE> NLCB
If it is K, the process proceeds to step S6.

In step S3, the downhill flag FBK =
If it is not 0 and the vehicle is not going downhill, the engine speed NE is increased to a predetermined speed NLC0 (for example, 1000 rpm
m) Determine if it is higher. And NE ≦ NLC
When it is 0, the process proceeds to step S13 to turn off the A solenoid valve 25a, and when NE> NLC0, the process proceeds to step S6.

In step S6, it is determined whether or not the shift position is in the D4 range, and if not, it is determined whether or not the shift position is in the D3 range (step S9). If it is not in either the D4 or D3 range, the process proceeds to step S13, where the A solenoid valve 25a is turned off.

If the range is the D3 range, step S10
To determine whether the lock-up flag FLCS was "1" last time. Immediately when FLCS = 0 and down count timer t when FLSC = 1.
mLCOFF is set for a predetermined time TLCOFF and started (step S11), and the process proceeds to step S12.
In step S12, it is determined whether or not the value of a down count timer tmDLY2 set in step S7 described below is "0". Immediately after shifting from the D4 range to the D3 range, since tmDLY2> 0, step S
36, and when tmDLY2 = 0, step S1
Proceed to 4.

On the other hand, when the range is the D4 range, step S
At 7, the down count timer tmDLY2 is set to the predetermined time TD.
LY2 is set and started.
It is determined whether or not the value of the timer tmLCOFF set in the step is "0". If the timer tmLCOFF is set in step S11 when the shift position is in the D3 range, the answer in step S8 is initially negative (NO), and the process immediately proceeds to step S15. If tmLCOFF = 0, the process proceeds to step S14, and it is determined whether or not the value of the timer tmDLY0 set in step S13 is "0". If tmDLY0> 0, the process proceeds to step S36.
To turn off the A solenoid valve 25a.

When tmDLY0 = 0 in step S14, the process proceeds to step S15, where the amount of decrease DNE (= NE (n-1) -NE (n)) of the engine speed NE is set to a predetermined value DN.
It is determined whether or not the value is larger than PANIC (for example, a value corresponding to a case where the speed is reduced by 200 rpm during 80 msec). When DNE> DPANIC and the amount of decrease in the engine speed NE is large, a predetermined time TDLY1 is set in the down count timer tmDLY1 and started (step S16), and the process proceeds to step S36.

In step S15, DNE≤DPANIC
If the decrease amount of the NE value is small, step S1
It is determined whether or not the value of the timer tmDLY1 set in step 6 is "0" (step S17). If tmDLY1> 0, the process proceeds to step S36. If tmDLY1 = 0, the process proceeds to step S18 (FIG. 3). .

In step S18, the throttle valve opening T
It is determined whether or not HW is greater than a predetermined idle opening THIDLE. If THW ≦ THIDLE, it is determined whether or not the gear position NGRAT is higher than the second speed (third or fourth speed) (step S25). ). As a result NGRAT
If ≦ 2 and the gear is 1st or 2nd, the above-described step S3
Proceed to 6, and turn off the A solenoid valve 25a.

If NGRAT> 2 and the third or fourth speed in step S25, the vehicle speed VP is increased to the predetermined vehicle speed VDE.
It is determined whether it is higher than CLCI (for example, 38 km / h) (step S26). Here, i is added to indicate that a different value is used depending on the gear position. That is, when the gear position is the third speed, the predetermined vehicle speed VDE for the third speed
Using the CLC3, when the vehicle is in the 4th speed, the predetermined vehicle speed VDE for 4th speed
Use CLC4. If VP ≦ VDECLCi, the process proceeds to step S36, where VP> VDECL
If it is Ci, it is determined whether or not deceleration fuel cut is being performed (step S27). Here, when the deceleration fuel cut is being performed, the process immediately proceeds to step S29, and when the deceleration fuel cut is not being performed, it is determined whether or not the downhill flag FBK is “1” (step S28). If FBK = 0 and the vehicle is not going downhill, the process proceeds to step S36, and FBK is performed.
If = 1 and the vehicle is going downhill, the process proceeds to step S29. Thereby, the area where the lock-up clutch 23 is engaged when the vehicle is going downhill is enlarged.

On the other hand, in step S18, THW> THIDL
When the vehicle speed is E, the vehicle speed VP is equal to the high-speed predetermined vehicle speed VLCSD.
jH (for example, 100 km / h) is determined (step S19), and when VP ≦ VLCSDjH, the lower predetermined vehicle speed VLCSDjL (for example, 20)
km / h) (step S2)
0). Here, j is added to indicate that a different value is used depending on whether the shift position is D3 or D4. That is, when the shift position is D3, VLCSD3H, VLCSD3
L, VLCSD4H, VLCSD4 for D4
L is used.

In step S19, VP> VLCSDjH
If it is, the process immediately proceeds to step S29, and if VP ≦ VLCSDjL in step S20, a predetermined time TDLY3 is set in the down count timer tmDLY3 and started (step S23), and the process proceeds to step S36. Also, VLCSDjL <VP ≦ VLCS
If it is DjH, the process proceeds to step S21 and the vehicle speed VP
Search the THLCSj table according to
The predetermined opening THLCSj used in step 2 is calculated. THL
The CSj table is set so that the predetermined opening THLCSj increases as the vehicle speed VP increases, as shown in FIG. Here, j is added to indicate that different tables are provided in the D3 range and the D4 range, and a table corresponding to the shift position is used. However, the setting tendency is as shown in FIG. 4 with the D3 and D4 ranges.

In the following step S22, it is determined whether or not the throttle valve opening THW is smaller than a predetermined opening THLCSj. If THW ≧ THLCSj, the routine proceeds to step S23. If THW <THLCS, it is determined whether the value of the timer tmDLY3 set in step S23 is "0" (step S24). The process proceeds to step S36 while tmDLY3> 0, and proceeds to step S29 when tmDLY3 = 0.

In step S29, it is determined whether or not the lock-up flag FLCS is "1". If FLCS = 1, the process immediately proceeds to step S35, where the A solenoid valve 2
5a The ON state is maintained.

On the other hand, when FLSC = 0, the variation DTH of the throttle valve opening THW (= THW (n) -TH
W (n−1)) is determined to be greater than or equal to “0” (step S30). If DTH ≦ 0, the change amount DT
Is the first predetermined change amount DTHCON.
It is determined whether or not it is greater than D (step S31), and | D
If TH |> DTHLCOND and the amount of change in the return direction of the throttle valve opening is large, a predetermined time TLCS is set in a down count timer tmLSC and started (step S33), and the process proceeds to step S36.

When DTH> 0 in step S30,
Alternatively, when | DTH | ≦ DTHLCOND in step S31, the change amount DTH is equal to the first predetermined change amount DTHLC.
It is determined whether or not the second predetermined change amount DTHCON is larger than OND (step S32), and DTH> DT
If it is HLCON, the process proceeds to step S33.
If DTH ≦ DTHCON, it is determined whether or not the value of the timer tmLCS set in step S33 is “0” (step S34). If tmLCS> 0, the process proceeds to step S36, where tmLCS = 0. Then, the process proceeds to step S35, where the lock-up flag FLC
S is set to "1" and the A solenoid valve 25a is turned on.

As described above, according to the processing of FIGS. 2 and 3, when an abnormality of the sensor is detected, when the engine coolant temperature TW is low, or when the engine speed NE is low (step SS
1, S2, S5), regardless of other conditions, the A solenoid valve 25a is turned off (lockup clutch is disengaged); otherwise, the shift position, gear position, throttle valve opening THW, throttle valve open The change amount THH of the degree THW,
The A solenoid valve 25a is turned on / off (engagement of the lock-up clutch /
Disengagement) is determined.

FIGS. 5, 6 and 7 show a B solenoid valve 25b.
It is a flowchart of a process of performing the duty control of,
This process is also performed for a predetermined time (for example, 80
msec).

First, in step S41, a predetermined opening THLCCj used for determination in step S52 described later is calculated by the following equation.

THLCCj = THLCSj-DTHLC Here, THLCSj is the value obtained in step S21 in FIG.
, And DTHLC is a subtraction term calculated according to the vehicle speed VP. Note that j indicates that a different value is used depending on the shift position (D3 range or D4 range).

In the following step S42, a predetermined high load side opening degree T used in steps S68 and S69 of FIG.
The HLCiH and the low load side predetermined opening THLCiL are shown in FIG.
Is searched and calculated according to the vehicle speed VP. The THLCi table is set so that the THLCi value increases as the vehicle speed VP increases. Further, i indicates that a different value is used depending on whether the gear position is the third speed or the fourth speed. As is apparent from FIG. 8, THLC4H> THLC3H, THLC4L> T
It has a relationship of HLC3L.

In the following step S43, the engine coolant temperature T
It is determined whether or not W is higher than a predetermined water temperature TWLC1 (for example, 30 ° C.). If TW ≦ TWLC1, a predetermined value C0 is set in a down counter CLCCWU which is decremented in step S46 described later and referred to in step S47. (Step S44), the B solenoid valve 25b
The control duty DOUT and the integral term DI used for calculating the DOUT value in the DEC mode or the feedback mode described later are both set to “0” (FIG. 6, step S5).
7), the lock mode is set to a non-engagement mode in which the lock-up clutch 23 is not engaged (step S58), the process proceeds to step S85, the control duty DOUT is output, and the process ends.

If TW> TWLC1 in step S43, it is determined whether the vehicle speed VP is higher than a predetermined vehicle speed VLCCWU (for example, 35 km / h) (step S4).
5) If VP ≦ VLCCWU, immediately
If P> VLCCWU, the counter CLCCWU is decremented by "1", and the flow advances to step S47.
In step S47, it is determined whether or not the value of the counter CLCCWU is greater than "0", and the process proceeds to step S57 while CLCCWU> 0. If the value of CLCCWU is equal to or less than "0", it is determined whether or not the lock-up flag FLCS is "1" (step S48), and FLCS =
When it is 0, the process proceeds to step S57, and the sleep mode is set.

When FLCS = 1, it is determined whether or not the throttle valve opening THW is larger than a predetermined idle opening THIDLE (step S49), and THW ≦ THID.
If it is LE, the process proceeds to step S50, and the gear position N
It is determined whether or not GRAT is higher than or equal to third speed. And NGR
When AT ≧ 3, the vehicle speed VP is equal to the predetermined vehicle speed VDECLC.
S (e.g., 70 km / h).
When GRAT <3 or when VP ≧ VDECCLCS, the process proceeds to step S57, and the sleep mode is set. If NGRAT ≧ 3 and VP <VDECCLCS, a DEC mode (deceleration mode) process described later is performed to determine the control duty DOUT (step S59), and the process proceeds to step S85.

In step S49, THW> THIDL
If E, it is further determined whether or not the throttle valve opening THW is smaller than the predetermined opening THLCCj calculated in step S41 (step S52), and THW ≧ THLC.
If it is Cj, a predetermined time TLCC is set in the down count timer tmmLCC and started (step S53), and the process proceeds to step S57 (pause mode).

If THW <THLCCj in step S52, the timer tmL set in step S53
It is determined whether the value of CC is “0” (step S54),
While tmLCC> 0, the process proceeds to step S57,
When tmLCC = 0, the process proceeds to step S55 (FIG. 6).

In step S55, it is determined whether or not the shift position is in the D3 range.
Is higher than a predetermined vehicle speed VD3FUL (for example, 130 km / h) (step S56), and VP ≦ VD3
If it is FUL, the process proceeds to step S57 (pause mode). If VP> VD3FUL, the process proceeds to step S73 to calculate the control duty DOUT by the following equation.

DOUT = DOUT (n−1) + DDATON Here, DOUT (n−1) is the control duty DOUT
, DDATON is a predetermined addition term.

In a succeeding step S74, it is determined whether or not the DOUT value is smaller than a predetermined value DATON.
If it is ATON, the processing in step S73 causes D
In addition mode (step S81) in which the OUT value is gradually increased, the process proceeds to step S85.

If DOUT ≧ DATON in step S74, the control duty DOUT and the integral term DI are both set to 100% (maximum engagement pressure) (step S7).
5) The 100% mode is set (step S76), and the process proceeds to step S85.

If it is determined in step S55 that the vehicle is not in the D3 range, the process proceeds to step S60, in which the vehicle speed VP is set to the predetermined vehicle speed VL
It is determined whether or not the speed is lower than CFB (for example, 60 km / h).
Proceed to 3. On the other hand, when VP> VLCFB, it is determined in steps S61 and S62 whether the gear position NGRAT is in the fourth speed or the third speed, and the following processing is performed according to the result.

(1) When the gear position NGRAT is the fourth speed In steps S66 and S67, the vehicle speed VP is increased to the predetermined vehicle speed VLCL.
4 (for example, 40 km / h), the predetermined vehicle speed V
It is determined whether it is higher than LCREF4 (for example, 20 km / h). If VP ≦ VLCREF4, the process proceeds to step S57 (pause mode), where VLC
If REF4 <VP <VLCL4, step S
The process proceeds to step S70, and if VP ≧ VLCL4, the process proceeds to step S68.

First, the processing after step S70 will be described.

In step S70, step S described later
A predetermined time TLCFB is set in a down count timer tmLCFB referred to by 71 and started, and the process proceeds to step S77 in FIG.
R calculation processing (FIG. 11) is performed. Next, it is determined whether or not the previous execution of this process was the REF mode (learning mode) using the learning control amount DOUTR (step S7).
8) When the current mode is not the REF mode, the previous value DOUT (n-1) of the control duty DOUT becomes the learning control amount DO.
It is determined whether it is smaller than UTR (step S7).
9). And when it was in REF mode last time or when DO
When UT (n−1) ≧ DOUTR, the integral term DI
Is set to the learning control amount DOUTR (step S82),
The control duty DOUT is set to the integral term DI (step S83), and the REF mode is set (step S8).
4) The process proceeds to step S85.

In step S79, DOUT (n-
1) When <DOUTR, the control duty DOUT is calculated by the following equation (step S80), the addition mode is set (step S81), and the process proceeds to the step S85.

DOUT = DOUT (n-1) + DDI Here, DDI is a predetermined addition term.

Next, the processing after step S68 will be described.

In steps S68 and S69, it is determined whether or not the throttle valve opening THW is smaller than the high load side predetermined opening THLCiH calculated in step S42 and whether or not it is larger than the low load side predetermined opening THLCiL. If THW ≧ THLCiH or THW ≦ THLCiL, the process proceeds to step S70 (REF mode or addition mode), where THLCiL <THW <THLCi.
If it is H, the timer t set in step S70
It is determined whether or not the value of mLCFB is “0” (step S
71). As a result, while tmLCFB> 0, the process proceeds to step S77 (REF mode or addition mode),
When tmLCFB = 0, a DOUT value calculation process in the F / B mode (feedback mode) (FIG. 1 described later)
0) (step S72), and the process proceeds to step S85.

(2) When the gear position NGRAT is the third speed In steps S64 and S65, the vehicle speed VP is set to the predetermined vehicle speed VLC.
It is determined whether it is lower than L3 (for example, 30 km / h) and whether it is higher than a predetermined vehicle speed VLCREF3 (for example, 20 km / h). If VP ≦ VLCREF3, the process proceeds to step S57 (pause mode), where V
If LCREF3 <VP <VLCL3, the process proceeds to step S70 (REF mode or addition mode),
If VP ≧ VLCL3, the process proceeds to step S68 (F / B mode, REF mode or addition mode).

(3) When the gear position NGRAT is the first speed or the second speed The process proceeds to step S63, where the vehicle speed VP is set to the predetermined vehicle speed VLCL2.
(E.g., 20 km / h), the VP
When ≤VLCL2, the process proceeds to step S57 (pause mode), and when VP> VLCL2, the process proceeds to step S77 (REF mode or addition mode). Here, VP> VLCL2 holds only when the gear position NGRAT is the second speed.

As described above, according to the processes of FIGS. 5, 6 and 7, when the engine coolant temperature TW is low (step S43, T
When (W ≦ TWLC1) or when the A solenoid valve 25a is off (step S48, FLCS = 0), the sleep mode is set regardless of other conditions (step S58). Otherwise, the vehicle speed VP and the throttle valve opening are set. Pause mode, DEC mode, F /
One of the B mode, 100% mode, addition mode, and REF mode is selected, and the control duty DOUT of the B solenoid valve 25b is determined.

FIGS. 9 and 10 are flowcharts of the DEC mode processing in step S59 of FIG.

First, at step S91, the learning value LREFDECi of the DEC mode (i = 3 or 4;
DREFI (= LREFDECi-DI (n-1)) between the integral value and the previous value DI (n-1) of the integral term.
Then, it is determined whether or not the previous time was also the DEC mode (step S92). Note that the learning value LREFD
ECi is set to a predetermined value in an initial state.

If the previous mode was also the DEC mode, the process immediately proceeds to step S96. If the previous mode was not the DEC mode, the absolute value | DRE of the deviation calculated in step S91 is used.
It is determined whether FI | is greater than a predetermined value DREFIG (step S93). And | DREFI | ≦ DR
If it is EFIG, the previous value DI (n-1) of the integral term used in step S108 described later is set to the learning value LREF.
Replace with DECi (step S95), | DREFI
If |> DREFIG, the previous value DI of the integral term is updated by the following equation (step S94), and
Go to 96.

DI (n−1) = DI (n−1) + KRD × DREFI Here, KRD is a predetermined value set to a value near 0.5, for example, when the DREFI value is positive and negative. Are set to different values.

In step S96, it is determined whether or not the difference between the target engine speed NOBDECi and the detected engine speed NE (see steps S104 and S106) DNLC (previous calculated value) is smaller than a predetermined value DNLCLMT. If the current time is DNLLCLMT, a predetermined time TDEC is set in the down count timer tmDEC and started (step S97), and the gear position NGRA is started.
It is determined whether or not T is the fourth speed (step S100). If it is the fourth speed, the process proceeds to step S101 described later, while if the answer is negative (NO), the gear position is the third speed (see step S50 in FIG. 5), and the target rotational speed NOBDEC3 is set by the following equation. (Step S1
05), and calculate a deviation DNLC (step S10).
6).

NOBDEC3 = K3 × VP DNLC = NOBDEC3-NE Here, K3 is a coefficient that changes the vehicle speed VP to an engine speed value such that the slip ratio ETR of the lock-up clutch 3 becomes about 102%. However, the slip rate ET
R is defined by the following equation, and ETR> 100% means that the target is a state where the input rotation speed NM of the gear mechanism 24 is higher than the engine rotation speed NE.

ETR = NM / NE In step S96, if DNLC ≧ DNCLMT and the deviation DNLC is large, it is determined whether or not the value of the timer tmDEC set in step S97 is “0” (step S98). If tmDEC> 0, the process proceeds to step S100. If tmDEC = 0, the process proceeds to step S99, where the gear position NGRAT is set to the fourth speed, and it is determined whether the downhill flag FBK is “1” (step S100).
101). When FBK = 0 and the vehicle is not going downhill, the coefficient K4 is used according to the following equation, and FBK = 1.
When the vehicle is going downhill, the target rotation speed NOBDEC4 is calculated using the coefficient K4BK (steps S102 and S102).
103), and proceed to step S104.

NOBDEC4 = K4 × VP NOBDEC4 = K4BK × VP Here, K4 is set so that the slip ratio ETR is, for example, about 104%, and K4BK is set so that the slip rate ETR is set to, for example, about 106% (K4BK> K4). ) Is set.

In step S104, the deviation DNLC is calculated by the following equation.

DNLC = NOBDEC4-NE In the following step S107, the proportional term DP and the addition term DD
I is calculated by the following equation, and further, the integral term DI and the control duty DOUT are calculated using these values (steps S108 and S109), and the process proceeds to step S110 in FIG.

DP = KPOAT × DNLC DDI = KIOAT × DNLC DI = DI (n−1) + DDI DOUT = DI + DP Here, KPOAT and KIOAT are predetermined coefficients.

In step S110 of FIG. 10, it is determined whether or not the DOUT value calculated in step S109 is larger than "0". If DOUT> 0, the down count timer tmDECLC timer is set to a predetermined time TDECLC.
Is set and started (step S111), and the process proceeds to step S114. If DOUT ≦ 0, the timer is set in step S111 and the timer tmDECL is set.
It is determined whether the value of C is "0" (step S112),
If tmDECLC> 0, the process proceeds to step S114. If tmDECLC = 0, the process proceeds to step S113, where the DOUT value is set to “0” and the process is immediately terminated.

In step S114, it is determined whether or not the vehicle speed VP is lower than a predetermined vehicle speed VDEC1, and VP <VDEC
When it is 1, the predetermined vehicle speed VDEC0 (<VDE0
C1) It is determined whether it is higher than (Step S11)
5). If VDEC0 <VP <VDEC1, it is determined whether the engine coolant temperature TW is higher than a predetermined coolant temperature TWLCREF (for example, 75 ° C.) (step S11).
6) When TW> TWLCREF, it is determined whether or not the downhill flag FBK = 1 (step S11).
7).

As a result, when one of the answers in steps S114 to S116 is negative (NO), or when step S117
Is affirmative (YES), that is, VP ≧ VPDE
When C1 or VP ≦ VDEC0 or TW ≦ TWLCREF or FBK = 1, this processing is immediately terminated without calculating the learning value, and FBK =
If it is 0, it is determined whether the gear position is the fourth speed (step S118). Then, according to the gear position (3rd speed or 4th speed), the learning value LR is calculated by the following equation.
EFDECi is calculated (steps S119, S12
0) and perform a limit check (step S12)
1), end this processing.

LREFDECi = CREFDEC × DO
UT / A + (A-CREFDEC) × LREFDECi
Here, A is a constant set to, for example, 1000 (hexadecimal), and CREFDEC is a smoothing coefficient set to a value between 1 and A.

The limit check is based on the learning value LRE.
When the FDECi value is out of the range of the predetermined upper and lower limits,
This is a process of setting the LREFDECi value to the upper and lower limit values. As described above, according to the processing in FIGS. 9 and 10, in the DEC mode, the slip ratio ETR exceeds 100% (NM>
NE) The DOUT value is determined so as to become the target value (steps S100 to S109), and the learning value LREFDECi is calculated for each gear position (step S100).
119, S120), used immediately after the shift to the DEC mode as the initial value of the integral term DI (step S9).
4, S95).

In steps S101 and S103, the target DN of the engine is set to be higher during a downhill to increase the deviation DNLC (step S1).
04) Since the control duty DOUT is increased to increase the engagement pressure, the engine brake can be more effectively applied. According to the downhill traveling detection method of the present embodiment, as described later, it is also possible to detect a gradual downhill traveling on a gently long downhill which could not be detected by the conventional technology. Can be made to act. Further, normally, when the engine speed NE is equal to or higher than a predetermined value, it is determined that the engine is in the fuel cut region. Therefore, when the engine speed NE is increased, the fuel cut is executed, and the effect of improving fuel efficiency is obtained.

In step S116, when the engine coolant temperature TW is low (TW ≦ TWLCREF), the calculation of the learning value (steps S119 and S120) is prohibited, so that the oil viscosity of the hydraulic control mechanism 25 is high. Learning in the state is prohibited, and it is possible to prevent the occurrence of surging or shock due to the engagement pressure becoming too high at a normal operating temperature. In the present embodiment, learning is prohibited when the engine water temperature TW is equal to or lower than a predetermined value. However, the present invention is not limited to this. For example, the oil temperature TOIL of the hydraulic control mechanism 25 is detected, or the oil temperature TOIL is detected. May be estimated from the engine coolant temperature TW or the operating state of the torque converter 22, and when the detected or estimated oil temperature TOIL is equal to or lower than a predetermined value, learning may be prohibited.

The predetermined temperature TWLC0 (step S2 in FIG. 2) for determining whether or not the lock-up clutch 23 is in the disengaged state is set to, for example, 30 ° C. (For example, the engine water temperature TW is higher than TWLCREF (70 ° C.)), the learning value learned at a high temperature may be used at a low temperature, but in this case, the engagement pressure is higher than a desired value. Since the setting is on the lower side, no shock or surging occurs. That is, it is possible to improve the fuel efficiency by engaging the lock-up clutch even at a low temperature while preventing shock and surging.

FIG. 11 is a flowchart of the F / B mode processing in step S72 of FIG.

First, in step S131, it is determined whether or not the previous mode was the F / B mode. When the answer is negative (NO), the integral term DI is set to the learning value LREFBi (step S131).
148 and S149) (step S13).
2) The control duty DOUT is set to the integral term DI (step S133), and the process proceeds to step S144.

If the previous gear was also in the F / B mode, it is determined whether the gear position is the fourth gear (step S134). If the gear is not the fourth gear, that is, the third gear, the coefficient K3 is calculated by the following equation.
FB is calculated (step S135).

K3FB = KNOBJ3 + (THW-TH
LC3L) × KATTH3 where KNOBJ3 and KATTH3 are predetermined coefficients, T
HLC3L is a predetermined throttle valve opening. The coefficient K3FB is set such that the slip ratio ETR is, for example, about 98%.

In the following steps S136 and S137,
The target rotational speed NOBFB3 is calculated by the following equation, and the deviation DNFB of the engine rotational speed NE is calculated by using the following formula.
Go to 41.

NOBFB3 = K3FB.times.VP DNFB = NE-NOBFB3 On the other hand, when the fourth speed is set in step S134, a coefficient K4FB is calculated by the following equation (step S138).

K4FB = KNOBJ4 + (THW-TH
LC4L) × KATTH4 where KNOBJ4, KATTH4 are predetermined coefficients, T
HLC4L is a predetermined throttle valve opening. The coefficient K4FB is set such that the slip ratio ETR is, for example, about 96%.

In the following steps S139 and S140,
The target rotational speed NOBFB4 is calculated by the following equation and the deviation DNFB of the engine rotational speed NE is calculated by using the following formula.
Go to 41.

NOBFB4 = K4FB × VP DNFB = NE−NOBFB4 In steps S141 to S143, the proportional term DP and the addition term DDI are calculated by the following equations, and the integral term DI is calculated.
And the control duty DOUT is calculated, and step S1
Go to 44.

DP = KPFB × DNFB DDI = KIFB × DNFB DI = DI (n−1) + DDI DOUT = DI + DP In step S144, it is determined whether or not the DOUT value exceeds a predetermined limit value, and DOUT ≦ DLMT. Immediately, and when DOUT> DLMT,
The process proceeds to step S146 with DOUT = DLMT.

At step S146, engine water temperature TW
Is higher than a predetermined water temperature TWLCREF.
When W ≦ TWLCREF, this processing is immediately terminated. When TW> TWLCREF, the gear position NG
It is determined whether the RAT is in the fourth speed (step S14).
7) According to the gear position, the learning value LREFF is calculated by the following equation.
Bi is calculated (steps S148 and S149), a limit check is performed (step S150), and the process ends.

LREFFBi = CREFFB × DOUT
/ A + (A−CREFDEC) × LREFFBi (n−
1) / A Here, CREFFB is a smoothing coefficient set to a value between 1 and A.

As described above, according to the processing of FIG.
In the B mode, the DOUT value is determined so that the slip ratio ETR becomes a target value smaller than 100% (NM <NE) (steps S135 to S143), and the learning value LREFFBi is calculated for each gear position ( Steps S148 and S149) are used as initial values of the integral term DI immediately after the shift to the F / B mode (step S132).

In step S146, when the engine coolant temperature TW is low (TW ≦ TWCREF), the calculation of the learning value is prohibited, so that the learning of the hydraulic control mechanism 25 when the oil viscosity is high is prohibited. It is possible to prevent the occurrence of surging or shock due to excessively high engagement pressure at a normal operating temperature (A95-72).
8 / JP-5384).

FIG. 12 is a flowchart of the DOUTR calculation process in step S77 of FIG.

First, in step S161, it is determined whether or not the throttle valve opening THW is larger than the predetermined low load side opening THLCiL calculated in step S42 of FIG.
When HW ≦ THLCiL, the learning control amount DOUT
R is set to a predetermined value DOUTRL (step S16)
2), proceed to step S170.

If THW> THLCi in step S161, it is determined whether or not the gear position NGART is the second speed. If the gear position NGART is the second speed, the learning control amount D is determined by the following equation.
OUTR is calculated (step S164), and step S1 is performed.
Go to 70.

DOUTR = LREFFB3 × KR Here, LREFFB3 is a learning value for the third speed calculated in the F / B mode (step S148 in FIG. 11).
R is a correction coefficient calculated by searching a KR table shown in FIG. 13A according to the throttle valve opening THW.
The KR table is set so that the KR value increases as the throttle valve opening THW increases.

As described above, steps S163 and S164
Thus, the lock-up clutch 23 is engaged even in the second speed, and the learning value KREFFB in the third speed is corrected according to the throttle valve opening THW to control the control duty DOUT.
(Controlling the engagement pressure), the EC
The lock-up control at the low speed stage can be performed without impairing the drivability while suppressing an increase in the capacity of the storage device of U2.

If it is not the second speed in the step S163, the throttle valve opening THW is changed to the high load side predetermined opening THL.
It is determined whether it is greater than CiH (step S16).
5) If THW ≦ THLCiH, the learning control amount DOUTR is set to the learning value LREFFBi (step S166), and the process proceeds to step S170.

In step S165, THW> THLC
iH, the deviation DTHR (= THW) between the throttle valve opening THW and its high-load-side predetermined opening THLCiH.
-THLCiH) (step S167), and searches the DDOUTRj table shown in FIG. 13B according to the deviation DTHR to calculate the correction amount DDOUTRj.
The DDOUTRj table is set so that the correction amount DDOUTRj increases as the deviation DTHR increases. Note that j is added to indicate that a table of different set values is provided depending on whether the shift position is D3 or D4. However, the tendency of the setting is as shown in FIG.

In the following step S169, the learning control amount DOUTR is calculated by the following equation, and the flow advances to step S170.

DOUTR = LREFFBi + DDOUTRj In step S170, it is determined whether or not the learning control amount DOUTR is larger than a predetermined upper limit value DOUTRH.
Immediately when R ≦ DOUTRH, and DOUTR
If> DOUTRH, the DOUTR value is set to its upper limit value DOUTRH (step S171), and the process ends.

As described above, according to the process of FIG. 12, when the throttle valve opening THW is smaller than the lower limit predetermined opening THLCiL, the learning control amount DOUTR becomes the predetermined value DOUTR.
L. Otherwise, the learning value LREF is set according to the gear position, shift position, and throttle valve opening THW.
FBi or a value obtained by correcting FBi.

FIG. 14 is a flowchart of a process for determining whether or not the vehicle is in the downhill mode, that is, whether or not the vehicle is traveling on a downhill road. This process is executed every time a TDC signal pulse is generated.

First, in step S181, it is determined whether or not an abnormality of a sensor or the like is detected, and if detected, a predetermined traveling state described later is indicated by "1" (step S195). The flag FDH is reset to "0" (step S192), the downhill flag FBK is set to "0" (step S196), and the process ends.

If the answer to step S181 is negative (NO) and no abnormality is detected in the sensor or the like, it is determined whether the shift position is in the D range (D3, D4) or the R (reverse) range. In step S182, if the air conditioner is in the D range or the R range, it is determined whether the air conditioner is off (step S183). If the air conditioner is off, whether the engine water temperature TW is higher than a predetermined water temperature TWBK is determined. Is determined (step S184), and TW> TWB
If it is K, it is determined whether the vehicle speed VP is higher than a lower limit vehicle speed VPBK1 (for example, 35 km / h) (step S).
185), when VP> VPBK1, the upper limit vehicle speed V
It is determined whether it is lower than PBK4 (for example, 70 km / h) (step S186), and if VP <VPBK4, the decrease amount DNE of the engine speed NE is set to a predetermined value DNE.
It is determined whether it is smaller than BK (step S187),
When DNE <DNEBK, the throttle valve opening T
It is determined whether or not HW is equal to or less than a predetermined idle opening THIDLE (step S188). If THW ≦ THIDLE, the engine speed NE is equal to the predetermined engine speed NBK (70).
0 rpm) is determined (step S18).
9).

The above steps S182 to S186, S1
If the answer to any of S88 and S189 is negative (NO), the down count timer tmBK is set to the predetermined time TBK.
(For example, 5 to 10 seconds) is set and started (step S191), and the process proceeds to step S192. Also,
If the answer to step S187 is negative (NO), the process immediately proceeds to step S196.

If the answers in steps S182 to S189 are all affirmative (YES), it is determined whether or not the value of the timer tmBK set in step S191 is "0" (step S190). Step S
Proceeding to 196, if tmBK = 0, step S193
To determine whether the predetermined state flag FDH is "1". Since FDH = 0 at first, step S194
And the vehicle speed VP becomes the first determination vehicle speed VPBK2 (for example, 4
5 km / h), VP ≧ VPBK
When VP <VPBK2, the flow proceeds to step S196 immediately, whereas when VP <VPBK2, it is determined that the vehicle is in the predetermined traveling state, the flag FDH is set to "1", and the flow proceeds to step S196.

When the predetermined state flag FDH is set to "1", the answer to step S193 is affirmative (YES).
Then, the process proceeds to step S197 to determine whether the vehicle speed VP is higher than the second determination vehicle speed VPBK3 (for example, 55 km / h). As a result, when VP ≦ VPBK3, the present process is immediately terminated. When VP> VPBK3, it is determined that the vehicle is going downhill, and the downhill flag FBK is set to “1” (step S198), and the present process is executed. finish.

The lower limit vehicle speed VPBK1, the upper limit vehicle speed VPBK4, the first determined vehicle speed VPBK2, and the second determined vehicle speed VPBK3 are VPBK1 <VPBK2 <VPBK3 <
It has a relationship of VPBK4.

According to the processing of FIG.
The state where all the answers of S189 are affirmative (YES) continues for the predetermined time TBK or more, and the vehicle speed VP is VPBK1 <VP <VP
When shifting from the state of BK3 to the state of VP> VPBK3, it is determined that the vehicle is going downhill. That is, since this process does not make a downhill judgment based on the acceleration of the vehicle, it is possible to make an accurate downhill judgment even when the vehicle is descending a long gentle downhill and the acceleration is small. .

The downhill flag FBK set in this way is referred to in step S28 of FIG. 3. When the vehicle is going downhill, the A solenoid valve 25a is engaged, and the lock-up clutch 23 is engaged. Since the region is enlarged, the engine brake can be effectively applied.

[0111]

As described above in detail, according to the present invention, a learned value of the control amount of the engagement capacity of the lock-up clutch is calculated and stored at the time of traveling at a predetermined speed, and the speed is lower than the predetermined speed. When the vehicle is traveling, the learned value is corrected in accordance with the engine load and used for controlling the engagement capacity of the lock-up clutch, so that the lock-up control at the low speed stage is performed while suppressing an increase in the capacity of the storage device. It can be performed without impairing the performance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an automatic transmission mounted on a vehicle and a control device thereof according to an embodiment of the present invention.

FIG. 2 is a flowchart of a process for performing on / off control of a solenoid valve of a hydraulic control mechanism.

FIG. 3 is a flowchart of a process for performing on / off control of a solenoid valve of a hydraulic control mechanism.

FIG. 4 is a diagram showing a table used in the processing of FIG. 3;

FIG. 5 is a flowchart of a process for performing duty control of a solenoid valve of the hydraulic control mechanism.

FIG. 6 is a flowchart of a process for performing duty control of a solenoid valve of the hydraulic control mechanism.

FIG. 7 is a flowchart of a process for performing duty control of a solenoid valve of the hydraulic control mechanism.

FIG. 8 is a diagram showing a table used in the processing of FIG. 5;

FIG. 9 is a flowchart showing details of a part of the process of FIG. 5;

FIG. 10 is a flowchart showing details of a part of the process of FIG. 5;

FIG. 11 is a flowchart showing details of a part of the process of FIG. 5;

FIG. 12 is a flowchart showing details of a part of the process of FIG. 5;

FIG. 13 is a diagram showing a table used in the processing of FIG. 11;

FIG. 14 is a flowchart of a process for determining whether the vehicle is traveling downhill.

[Description of Signs] 2 Electronic control unit 3 Throttle valve opening sensor 21 Automatic transmission 22 Torque converter 23 Lock-up clutch 24 Gear mechanism 25 Hydraulic control mechanism 27 Gear position sensor 28 Vehicle speed sensor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 61/14

Claims (1)

(57) [Claims] An automatic transmission lock provided with a region for controlling the engagement capacity of the lock-up clutch so that the slip amount of the lock-up clutch of the automatic transmission becomes a predetermined target value according to the driving state of the vehicle. In the up control device, learning means for learning an engagement capacity control amount during engagement capacity control of the lock-up clutch during traveling at a predetermined shift speed in the region, and storage for storing a learning value learned by the learning means. Means for increasing the engine load according to the engine load at the time of traveling at a shift speed lower than the predetermined shift speed in the region, in accordance with the engine load at the time of traveling.
A lock-up control device for an automatic transmission, wherein the lock-up clutch engagement capacity is controlled by using an engagement capacity control amount calculated by correcting the lock-up clutch so as to increase the lock-up clutch.