JP3698113B2 - Automatic transmission lockup control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lockup control device for appropriately controlling a lockup state in which a torque converter inserted in a transmission system of an automatic transmission is directly connected between input and output elements during inertial traveling including deceleration of a vehicle. is there.
[0002]
[Prior art]
The automatic transmission is designed to improve the fuel efficiency by improving the transmission efficiency, and the input / output elements of the torque converter can be adjusted under the vehicle operating condition in the lockup region where the torque increasing function and the torque fluctuation absorbing function are unnecessary. A lock-up type that can be brought into a lock-up state in which the spaces are directly connected is adopted.
[0003]
For lock-up control of this type of torque converter, conventionally, for example, as seen in the automatic transmission described in the “NISSAN RE4R01A full-range electronically controlled automatic transmission maintenance manual” issued by the applicant of the present application, and locked in FIG. As an example of an up ON line by a two-dot chain line, and an example of a lock-up OFF line by a one-dot chain line,
It is determined whether the vehicle is operating in the lockup (L / U) region or the converter (C / V) region defined by the throttle opening TH (engine operation load) and the vehicle speed V, and according to the determination result. In the lock-up area, the lock-up clutch is engaged and the input / output elements are directly connected in the lock-up state, and in the converter area, the lock-up clutch is released and the direct connection is released. Is customary.
[0004]
By the way, in order to increase the fuel efficiency improvement effect by the lock-up of the torque converter, it is necessary to expand the lock-up region so that the torque converter is locked up to a low load operation and a low vehicle speed as much as possible. It is defined as 16.
[0005]
On the other hand, as a device for improving the fuel consumption of the vehicle, since the power from the so-called coasting engine including the deceleration with the accelerator pedal released is unnecessary, the fuel cut device that stops the fuel supply to the engine during this period There is.
In this apparatus, when the engine speed decreases to a set speed (fuel recovery speed), the fuel cut is stopped and fuel supply is resumed (fuel recovery) in order to prevent engine stall.
In such a device, the fuel cut time becomes longer and the fuel consumption improvement effect is greater when the decrease in the engine speed during inertial running is delayed.
For this reason, generally, in an engine-equipped vehicle with a fuel cut device, as shown in FIG. 16, it is common practice to lock the inertial running torque converter with the throttle opening TH set to 0/8.
[0006]
[Problems to be solved by the invention]
For these reasons, the torque converter during inertial running of the vehicle is becoming a lock-up state in which the input and output elements are directly connected, but when braking by depressing the brake pedal during running in such a state, Especially on low friction roads, the rotation of the wheels suddenly stops, so the lockup release that cannot avoid a relatively large response delay of the torque converter cannot catch up with this, and the engine connected to the wheels stops. There was a problem of concern.
[0007]
Conventionally, as described in JP-A-4-370465, when the brake pedal is depressed during inertial running, the torque converter in the lock-up state is switched to the slip control state in which slip is generated to allow relative rotation between the input and output elements. In addition, there has been proposed a technique for releasing the lock-up of the torque converter at the time of sudden deceleration with further increased brake pedal depression force.
[0008]
According to this technology, although the problem of engine stall due to the delay in response to unlocking can be solved, the torque converter is immediately slipped when coasting despite the fact that it is not sudden braking. Arise.
In other words, the slip of the torque converter reduces the engine speed by the slip amount, so that the fuel cut must be stopped and the fuel recovered as soon as possible, and the fuel efficiency improvement effect by the fuel cut is diminished.
In other words, it can be said that the above-described conventional technology has taken measures to prevent engine stall at the expense of fuel efficiency improvement effect by fuel cut.
[0009]
The present invention is based on the fact that the response delay of the lockup release changes according to the engagement capacity of the lockup clutch as shown in FIG. 17, that is, the lockup release command instant t as shown in FIG. ₁ As the lock-up clutch engagement capacity immediately before is decreased from the solid line to the dotted line, and from the dotted line to the one-dot chain line, the lock-up release pressure P showing a change with time in a similar corresponding line. _R And lock-up fastening pressure P _A Response delay until lock-up release completed at the moment of intersection with ₁ , ΔT ₂ , ΔT _Three Based on the fact that
And because the above-mentioned problem that the fuel efficiency improvement effect by fuel cut is weakened is because the torque converter slips immediately when it becomes inertia running even though it is not sudden deceleration,
During coasting that is not suddenly decelerating, the lockup clutch engagement capacity should be the smallest in the range where torque converter slip does not occur, and without sacrificing the fuel efficiency improvement effect of fuel cut. An object is to realize prevention of engine stall due to a delay in response to unlocking.
[0010]
[Means for Solving the Problems]
For this purpose, an automatic transmission lock-up control device according to the present invention is as set forth in claim 1,
Assuming a vehicle equipped with an automatic transmission having the torque converter with a lock-up clutch in the transmission system,
Inertia running detection means for detecting during inertia running including deceleration operation of the vehicle;
Sudden deceleration detection means for detecting a large deceleration greater than the set value of the vehicle;
In response to the signals from both of these detecting means, while the inertial vehicle is running and the vehicle deceleration is less than the set value, the engagement capacity of the lock-up clutch is the most in the range where no relative rotation occurs between the torque converter input / output elements. Inertia travel lock-up capacity control means for controlling to a small inertia travel fastening capacity is provided.
[0011]
Here, the inertia traveling lockup capacity control means includes a reverse driving torque detecting means for detecting the reverse driving torque of the prime mover at the forward stage of the automatic transmission, and the inertia traveling fastening from the reverse driving torque detected by the means. It is configured to include inertial running lockup capacity calculating means for calculating capacity.
The reverse drive torque detecting means is configured to correct the reverse drive torque detection value of the prime mover by the amount of torque increase / decrease by the accessory according to whether the accessory to be driven by the prime mover is activated or deactivated.
[0012]
The lockup control device for an automatic transmission according to the present invention can be configured as described in claim 2 to achieve the above object.
That is, in most cases, the configuration is the same as described above, but the reverse drive torque detection means is configured to correct the reverse drive torque detection value of the prime mover according to the coolant temperature of the prime mover, instead of the above.
[0013]
【The invention's effect】
In the first aspect of the invention, the inertial travel lockup capacity control means detects that the inertial travel detection means is in inertial traveling including the deceleration operation of the vehicle, but the sudden deceleration detection means is larger than the set value of the vehicle. While no deceleration is detected, that is, while coasting, while the vehicle deceleration is less than the set value, the engagement capacity of the lockup clutch is the smallest coasting within a range where no relative rotation occurs between the torque converter input / output elements. Control the fastening capacity.
[0014]
By the way, during inertial traveling in which the vehicle deceleration is less than the above set value, the engagement capacity of the lockup clutch is controlled to the smallest inertial traveling engagement capacity within a range in which relative rotation does not occur between the torque converter input and output elements. After that, when the vehicle deceleration exceeds the set value, the lock-up clutch release can be quickly completed with a small response delay, eliminating the concern that the prime mover will stop during sudden deceleration. Can do.
Such an effect is not achieved by the slip control of the torque converter, but is obtained while maintaining the lock-up state of the torque converter, as in the case of relying on the slip control. There is no adverse effect that the fuel cut time is shortened and the fuel efficiency improvement effect by the fuel cut is sacrificed.
[0015]
Further, in the present invention, the reverse drive torque detecting means detects the reverse drive torque of the prime mover at the front stage of the automatic transmission, and the inertial drive lockup capacity calculating means detects the reverse drive torque from the reverse drive torque detected by the means. Since the fastening capacity is calculated,
The inertia running fastening capacity is in line with the actual situation, and the fastening capacity control of the lock-up clutch during inertia running can be ensured to achieve the above-described effects.
[0016]
Further, in the present invention, the reverse drive torque detecting means corrects the reverse drive torque detection value of the prime mover by the amount of torque increase / decrease by the auxiliary device according to the operation / non-operation of the auxiliary device to be driven by the prime mover. The detection of the reverse drive torque can be made accurate without being affected by the operation and non-operation of the machine, and the engagement capacity control of the lock-up clutch during inertial running can be influenced by the operation and non-operation of the auxiliary machine. The above-described effects can be achieved more reliably.
[0017]
In the second aspect of the invention, since the reverse drive torque detecting means corrects the reverse drive torque detection value of the prime mover according to the coolant temperature of the prime mover, the reverse drive torque is detected without being affected by the temperature change of the prime mover. The detection can be made accurate, and the engagement capacity control of the lockup clutch during inertial running can be achieved more reliably without being affected by the temperature change of the prime mover. it can.
[0018]
Note that, regardless of which of the configuration described in claim 1 or the configuration described in claim 2 is adopted, as described in claim 3, the brake detection means detects that the vehicle is being braked, and the accelerator operation is detected. When the means detects depression of the accelerator pedal, the lockup clutch may be forcibly released by the lockup forced release means.
During driving operation such as depressing the accelerator pedal while braking, the inertial travel detection means cannot be detected, so the inertial travel lockup capacity control means before the sudden deceleration, the lockup clutch engagement capacity, Although it is not possible to expect the effect of obtaining the smallest inertial travel fastening capacity within a range where relative rotation does not occur between the torque converter input / output elements, the corresponding effect cannot be obtained. Since the lockup clutch is forcibly released in advance as described above, the engine stall can be prevented.
[0019]
Further, as described in claim 4, when the inertial travel lockup capacity control means controls the engagement capacity of the lockup clutch according to a predetermined command value, the inertial travel detection means determines that the inertial travel detection means It is preferable to set a value corresponding to the release of the lockup clutch during the set time after detecting the shift of.
In this case, the engagement capacity of the lock-up clutch can be quickly reduced to the smallest inertia traveling engagement capacity within a range in which relative rotation does not occur between the torque converter input / output elements. Therefore, even if rapid deceleration is detected before the fastening capacity is reduced, it is feared that the above-mentioned effect cannot be expected. However, this concern can be eliminated.
[0020]
Furthermore, as described in claim 5, the time measuring means measures the time from the end of the control by the inertia running lockup capacity control means to the next inertia running, and the shorter the measuring time by the means, the more the command It is preferable to shorten the set time for keeping the value corresponding to the release of the lockup clutch.
In this way, when the time from the end of the control by the inertial travel lockup capacity control means to the next inertial travel is short, the engagement capacity of the lockup clutch is still small before the lockup clutch is restored. In the configuration according to claim 4, wherein the displacement control command value is set to a value corresponding to the release of the lockup clutch, there is a tendency that the engagement capacity of the lockup clutch is made too low to deteriorate the fuel consumption. Then it can be solved.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a lockup control device for an automatic transmission according to an embodiment of the present invention. In this figure, 1 is an engine as a prime mover, and 2 is an automatic transmission.
The automatic transmission 2 receives the power of the engine 1 via the torque converter 3, shifts the input rotation at a gear ratio corresponding to the selected shift speed, and transmits it to the output shaft 4.
[0022]
Here, the automatic transmission 2 has a selected shift stage determined by a combination of ON and OFF of the shift solenoids 6 and 7 in the control valve 5, and the torque converter 3 similarly controls the duty of the lockup solenoid 8 in the control valve 5. Thus, the converter state in which the input / output elements are not directly connected or the lock-up state in which the input / output elements are directly connected by a lockup clutch (not shown) can be set.
When the drive duty D is 0%, the lockup solenoid 8 puts the torque converter 3 into a converter state by releasing the lockup clutch, and when the drive duty D is 100%, the torque converter 3 is brought into a lockup state by fastening the lockup clutch. Shall be.
[0023]
The ON and OFF of the shift solenoids 6 and 7 and the drive duty D of the lockup solenoid 8 are controlled by the controller 9,
The controller 9 receives a signal from a throttle opening sensor 10 that detects the throttle opening TH of the engine 1,
A signal from an engine rotation sensor 11 for detecting the rotation speed Ne of the engine 1;
A signal from the turbine rotation sensor 12 for detecting the input rotation speed (output rotation speed of the torque converter 3) Nt of the automatic transmission 2;
A signal from the transmission output rotation sensor 13 for detecting the rotational speed No of the transmission output shaft 4;
A signal from an oil temperature sensor 14 for detecting a transmission hydraulic oil temperature C, and
A signal B is input from the brake switch 15 that is turned on at the time of braking when the brake pedal is depressed.
[0024]
Although not shown in the figure, the controller 9 performs the following shift control by a known calculation based on these input information.
That is, in the shift control, the controller 9 obtains the optimum gear stage for the current driving state from the throttle opening TH and the vehicle speed V obtained from the transmission output rotation speed No by, for example, table data by a lookup method. The shift solenoids 6 and 7 are turned on and off to perform a predetermined shift so that the optimum shift stage is selected.
[0025]
Next, the lock-up control will be described. In this lock-up control, the controller 9 repeatedly executes the main routine of FIG. 2 by a scheduled interrupt every Δt = 10 msec.
First, at step 21, the throttle opening TH, the transmission output rotational speed No, and the transmission hydraulic oil temperature C are read. In the next step 22, the vehicle speed V is calculated from the transmission output speed No and set to V (NEW), and between the previous vehicle speed calculation value V (OLD) and the current vehicle speed calculation value V (NEW). The vehicle deceleration is obtained from the difference ΔV.
[0026]
In step 23, for example, the throttle opening TH and the vehicle speed V described above are obtained by a lookup method from table data corresponding to the lockup vehicle speed diagram shown in FIG. 16 (L / U is the lockup region, C / V is the converter region). Based on the above, it is determined which of the lock-up region L / U and the converter region C / V is running.
Here, when the converter region is C / V, the drive duty D of the lockup solenoid 8 is set to 0% in step 24, and this is output to the lockup solenoid 8 in step 30 to lock up the torque converter 3. The converter is brought into the normal state as required by releasing the clutch.
[0027]
If it is determined in step 23 that the lock-up region L / U is present, whether or not the vehicle is in inertial traveling including deceleration is determined in step 25 corresponding to inertial traveling detection means, depending on whether or not the throttle opening TH is less than the minute set value THs. Determine whether.
If it is determined that the vehicle is not coasting, the drive duty D of the lock-up solenoid 8 is set to 100% in step 26, and this is output to the lock-up solenoid 8 in step 30, whereby the torque converter 3 is connected to the lock-up clutch. The lock-up state is established as required and normally by fastening.
In step 25 as inertia running detection means, instead of the above, although not shown, it is also possible to determine whether or not the vehicle is coasting based on a signal from an idle switch that is turned on when the accelerator pedal is released. Needless to say.
[0028]
If it is determined in step 25 that the vehicle is coasting, it is determined in step 27 corresponding to the rapid deceleration detection means whether the vehicle is decelerating rapidly based on whether the vehicle deceleration ΔV is equal to or greater than a set value ΔVs.
If it is not sudden deceleration, in step 28 corresponding to the inertial travel lockup capacity control means, the lockup clutch engagement capacity for inertial travel is obtained, and the corresponding drive duty Dc% of the lockup solenoid 8 is calculated. This is set to the lockup solenoid drive duty D.
[0029]
This processing is as clearly shown in FIG. 3, and first, in step 61 corresponding to the reverse drive torque detecting means, the vehicle is coasting from the engine speed Ne based on the table data previously obtained by experiments and the like illustrated in FIG. The reverse drive torque T applied to the engine is searched and obtained.
Next, at step 62, the lockup release pressure P that is just balanced with the reverse drive torque T. _r Is calculated. Here, the lockup fastening pressure acting on the lockup clutch piston at all times in the direction opposite to the lockup release pressure is P _A When the pressure receiving area of the lock-up clutch piston is S, the facing friction coefficient is μ, and the average radius of the facing is R, the lock-up release pressure P is just balanced with the reverse drive torque T. _r But P _r = P _A − (T / S · μ · R) and lock-up fastening pressure P _A Is known to change as illustrated in FIG. 5 according to the line pressure controlled by the line pressure solenoid drive duty, which is an internal signal of the transmission controller 9, and can be searched. Lock-up release pressure P that just balances _r Can be calculated by the above equation.
[0030]
In step 63, which corresponds to the following inertia running lockup capacity calculation means, the lockup release pressure P just balanced with the reverse drive torque T calculated as described above. _r By subtracting a predetermined value δ from the target lockup release pressure P _R Ask for.
Here, the reason why the predetermined value δ is subtracted is that the lock-up release pressure P is just balanced with the reverse drive torque T. _r Then, since there is a possibility that the slip of the torque converter cannot be kept completely zero, the lockup release pressure P is given with a margin. _R This is because it is necessary to set.
[0031]
In the next step 64, the target lockup release pressure P _R For example, the duty Dc for achieving the above is retrieved based on the table data corresponding to FIG.
D = Dc% thus determined corresponds to the smallest lockup clutch engagement capacity (inertia travel engagement capacity) within a range where the torque converter 3 does not slip.
[0032]
Thereafter, when it is determined at step 27 in FIG. 2 that sudden deceleration has occurred, the drive duty D of the lockup solenoid 8 is set to 0% at step 29 corresponding to the sudden deceleration lockup release means, and this is locked up at step 30. Output to solenoid 8. As a result, the torque converter 3 is released from the lock-up state and enters the converter state, and the engine 1 can be prevented from being stopped by the braked drive wheels during the sudden deceleration of the vehicle.
[0033]
By the way, since the engagement capacity of the lock-up clutch is controlled so as to be the smallest engagement capacity for inertia travel in a range where the torque converter 3 does not slip as described above with reference to FIG.
That is, as shown in the time chart of FIG. ₁ From instant t ₂ Sudden deceleration t associated with braking operation _Three Until the lock-up release pressure P _R P corresponding to D = Dc% _RC This is the lock-up fastening pressure P _A Instant t intersecting _Four The above lock-up release that ends at the end of the _C Can be shortened, and concerns that engine stall may occur can be eliminated.
[0034]
According to such control, the above-described effect can be achieved without causing the torque converter 3 to slip. Therefore, the fuel cut time is shortened due to the decrease in the engine speed due to the slip, and the fuel consumption is improved due to the fuel cut. There is no problem that the effect is sacrificed.
[0035]
In this embodiment, the reverse drive torque T of the engine is obtained by searching, but it can also be directly detected by a torque sensor. However, it goes without saying that a search method that does not require additional sensors and is advantageous in terms of cost is better.
[0036]
By the way, when the torque sensor is not used, the searched reverse drive torque T is naturally the actual value depending on whether the air conditioner, the power steering device, the engine drive auxiliary machine such as the alternator is operated or not, and the engine coolant temperature. Since an error occurs during this period, it is preferable to perform correction to correct this error.
An air conditioner will be described as an example of an auxiliary machine. The driving load of the air conditioner does not change much depending on the engine speed Ne as shown in FIG. Only OFF is detected, and when ON, the air-conditioner driving load is added to the searched reverse driving torque T to contribute to the control of FIG. 3, and no correction is performed when OFF.
Further, the engine coolant temperature is substantially the same as the transmission hydraulic oil temperature C, and the reverse drive torque changes as illustrated in FIG. 8 accordingly, so that the reverse drive torque search value T is set to the temperature in anticipation of this change. Correction is made according to C.
[0037]
Incidentally, in the above-described embodiment, when the throttle opening TH becomes less than the set opening THs in step 25 of FIG. 2, it is determined that the vehicle is coasting, and the lockup clutch engagement capacity control during coasting as described above is performed. Therefore, for example, when an abnormal operation such as depressing the brake pedal while depressing the accelerator pedal using both feet is performed, it becomes impossible to perform the lockup clutch engagement capacity control during inertial running, It becomes a situation where the effect cannot be obtained.
[0038]
The operation of the above embodiment during such an abnormal operation will be described with reference to FIG. 11 corresponding to FIG.
Instantaneous t when the brake pedal is depressed while the accelerator pedal is depressed t ₂ At the moment t when the vehicle deceleration ΔV reaches the set deceleration ΔVs because the lockup clutch engagement capacity control during inertial running cannot be started. _Three As usual, the lockup release control during deceleration is performed, and the lockup fastening pressure P is _A And the lockup release pressure P as shown by the dotted line _R Rises and instant t when these pressures cross _Four Releases the lockup during deceleration.
Now, this is the lockup release time t _Four Is too slow and engine stall occurs as is apparent from the change over time indicated by the dotted line of the engine speed Ne.
[0039]
FIG. 10 shows an embodiment which solves this problem, and is an alternative to FIG.
In FIG. 10, steps for performing the same processing as in FIG. In the present embodiment, in step 21, the brake switch signal B is additionally read and step 71 is added between step 25 corresponding to the accelerator operation detecting means and the next step 26.
In step 71 corresponding to the brake detection means, it is checked whether the brake pedal is depressed or not depending on whether the brake switch signal B is ON or OFF.
If not braking, the control proceeds to step 26 and the same control as in FIG. 2 is executed. However, when it is determined that the braking is being performed, the control proceeds to step 24 to release the angular lockup. Issue a command.
Accordingly, step 24 corresponds to lock-up forced release means in the present embodiment.
[0040]
According to such control, referring to FIG. 11, the instant t when an abnormal operation is performed in which the brake pedal is depressed while the accelerator pedal is depressed. ₂ As shown by the solid line, the lock-up fastening pressure P _A And the lockup release pressure P as shown by the solid line _R Rises and the lock-up release instant at which these pressures cross each other is the instant t _Four Can be faster.
Accordingly, even when the brake pedal is depressed while the accelerator pedal is depressed, the instant t at which the vehicle deceleration ΔV becomes equal to or greater than the set deceleration ΔVs. _Three Thus, the lockup can be released at a time that is not delayed as far as from the left, and it is possible to prevent the engine stall from occurring as apparent from the change with time indicated by the one-dot chain line of the engine speed Ne.
[0041]
By the way, in each of the above embodiments, the lock-up clutch engagement capacity lowering control to be performed during inertial traveling is performed by the lock-up engagement pressure P _A Unlocking and lock-up release pressure P _R The inertial travel start instant t in FIG. ₁ From sudden deceleration instant t ₂ As is clear from the change in the lockup clutch engagement capacity in the period up to, the progress of the control is unavoidably delayed.
Therefore, the inertia running start instant t ₁ From sudden deceleration instant t ₂ In an operation with a short time until the lockup clutch engagement capacity is reduced to the target capacity for inertia traveling corresponding to the lockup solenoid drive duty D = Dc%, a lockup release command is issued. In some embodiments, the lock-up release may be delayed with respect to sudden deceleration, and the above-described embodiments may not achieve the intended effects.
[0042]
FIG. 12 shows an embodiment in which such a problem is solved, and this control program shows only the execution contents before the torque converter is locked up and before the vehicle is suddenly decelerated by a brake operation. And
First, in step 81, it is checked whether the throttle opening TH is less than the set opening THs, and it is checked whether or not the vehicle is coasting. If it is not coasting, the driving duty D is maintained at 100% in step 82 and locked. Keep up.
[0043]
If the vehicle is coasting, in step 83, the timer TM1 for measuring the elapsed time after shifting to coasting is shown in FIG. _R It is determined whether or not the minute set time indicated by is reached.
As shown in FIG. 14, the inertia running instant t ₁ To set time ΔT _R In step 84, the drive duty D is set to 0% corresponding to unlocking, and then in step 84, the drive duty D is obtained in the same manner as in each of the above embodiments. Set to.
According to such control, the minute set time ΔT _R By the drive duty sudden decrease operation in the middle, the lockup clutch engagement capacity can be quickly reduced to the target capacity for inertia traveling corresponding to D = Dc% as shown in FIG.
Therefore, the inertia running start instant t ₁ Instant t ₂ Even during the operation of suddenly decelerating, the lockup clutch engagement capacity at the time of the lockup release command corresponding to this sudden deceleration has not been reduced to the target capacity for inertia running corresponding to D = Dc%, It is possible to solve the problem that the lock-up release is delayed with respect to the sudden deceleration and the effect as intended in the present invention cannot be sufficiently achieved.
[0044]
FIG. 13 shows a further improved example of FIG. 12. In this improved example, a step 86 corresponding to a time measuring means is inserted between steps 81 and 83, where the coasting lockup clutch engagement capacity control in step 85 is performed. End (instantaneous t in FIG. ₂ ) To the next moment of inertia travel transition TM2 is set time ΔT _I It is determined whether it is less than or not.
TM2 ≧ ΔT _I If so, control proceeds to step 83 where control similar to that described above with respect to FIG. 12 is performed, but TM2 <ΔT _I If so, the control proceeds to step 85 and the minute set time ΔT in step 84 _R It is assumed that the drive duty sudden decrease operation is not performed.
[0045]
To explain the reason, TM2 <ΔT _I In this case, since the engagement capacity of the lock-up clutch is still small before returning to the original value, the minute set time ΔT _R This is because when the driving duty suddenly decreasing operation is performed, the engagement capacity of the lockup clutch becomes too low and the fuel consumption tends to be deteriorated.
[0046]
Here, TM2 <ΔT _I Is a minute set time ΔT _R In this case, TM2 is set to ΔT. _I The smaller the set time ΔT is, the shorter it is _R In this case, it is preferable to perform control that matches the actual situation.
And when TM2 becomes shorter than a certain level, ultimately ΔT _R = 0 and the minute setting time ΔT _R The driving duty sudden decrease operation is not performed.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of a lockup control device according to the present invention.
FIG. 2 is a main routine flowchart showing lock-up control performed by the transmission controller according to the embodiment;
FIG. 3 is a flowchart showing a calculation program in the case of obtaining a coasting lockup capacity by calculation in the embodiment;
FIG. 4 is a diagram showing a relationship between a reverse drive torque searched for in the embodiment and an engine speed.
FIG. 5 is a diagram showing a relationship between a lock-up fastening pressure searched for in the same embodiment and a line pressure solenoid driving duty.
FIG. 6 is a diagram showing a relationship between a lockup solenoid drive duty searched for in the same embodiment and a target lockup release pressure;
FIG. 7 is a characteristic diagram of an air conditioner drive load that affects the reverse drive torque searched in the embodiment.
FIG. 8 is a diagram showing a relationship between a reverse drive torque searched in the embodiment and an engine coolant temperature.
FIG. 9 is an operation time chart of the lockup control device in the embodiment shown in FIGS. 1 to 8;
FIG. 10 is a flowchart of a main routine showing lock-up control according to another embodiment of the present invention.
FIG. 11 is an operation tie time chart according to the embodiment.
FIG. 12 is a main part flowchart showing an improved example of the embodiment;
FIG. 13 is a main part flowchart showing a further improved example of the embodiment;
14 is an operation tie time chart according to the embodiment shown in FIG. 12; FIG.
FIG. 15 is an operation tie time chart used to explain inconvenience when the examples of FIGS. 12 and 13 are not improved.
FIG. 16 is a region diagram illustrating a lockup region of the automatic transmission.
FIG. 17 is a diagram showing a relationship between lockup clutch engagement capacity and lockup release response delay.
FIG. 18 is an operation time chart showing the relationship between the lockup clutch engagement capacity and the lockup release response delay.
[Explanation of symbols]
1 engine (motor)
2 Automatic transmission
3 Torque converter
5 Control valve
6 Shift solenoid
7 Shift solenoid
8 Lock-up solenoid
9 Controller
10 Throttle opening sensor
11 Engine rotation sensor
12 Turbine rotation sensor
13 Transmission output rotation sensor
14 Oil temperature sensor
15 Brake switch

Claims (5)

In a vehicle equipped with an automatic transmission having a torque converter in a transmission system that can be brought into a lockup state in which an input / output element is directly connected by a lockup clutch,
Inertia running detection means for detecting during inertia running including deceleration operation of the vehicle;
Sudden deceleration detection means for detecting a large deceleration greater than the set value of the vehicle;
In response to the signals from both of these detecting means, while the inertial vehicle is running and the vehicle deceleration is less than the set value, the engagement capacity of the lock-up clutch is the most in the range where no relative rotation occurs between the torque converter input / output elements. A coasting lockup capacity control means for controlling to a small inertia traveling fastening capacity;
This inertial traveling lockup capacity control means calculates reverse inertia torque from the reverse driving torque detected by the reverse driving torque detecting means for detecting the reverse driving torque of the prime mover at the forward stage of the automatic transmission. A coasting lockup capacity calculating means for
The reverse drive torque detection means is configured to correct the reverse drive torque detection value of the prime mover by an amount corresponding to an increase or decrease in torque by the accessory according to the operation or non-operation of the accessory to be driven by the prime mover. Automatic transmission lockup control device. In a vehicle equipped with an automatic transmission having a torque converter in a transmission system that can be brought into a lockup state in which an input / output element is directly connected by a lockup clutch,
Inertia running detection means for detecting during inertia running including deceleration operation of the vehicle;
Sudden deceleration detection means for detecting a large deceleration greater than the set value of the vehicle;
In response to the signals from both of these detecting means, while the inertial vehicle is running and the vehicle deceleration is less than the set value, the engagement capacity of the lock-up clutch is the most in the range where no relative rotation occurs between the torque converter input / output elements. A coasting lockup capacity control means for controlling to a small inertia traveling fastening capacity;
This inertial traveling lockup capacity control means calculates reverse inertia torque from the reverse driving torque detected by the reverse driving torque detecting means for detecting the reverse driving torque of the prime mover at the forward stage of the automatic transmission. A coasting lockup capacity calculating means for
2. The automatic transmission lockup control device according to claim 1, wherein the reverse drive torque detecting means is configured to correct a reverse drive torque detection value of the prime mover in accordance with a coolant temperature of the prime mover. 3. The lockup control device according to claim 1 or 2, wherein the braking detection means for detecting that the vehicle is being braked, the accelerator operation detection means for detecting that the accelerator pedal of the vehicle is depressed, and the braking detection by these means. And a lockup forced release means for forcibly releasing the lockup clutch when the accelerator pedal depression is detected at the same time. The lockup control device according to any one of claims 1 to 3, wherein the inertial traveling lockup capacity control means controls a fastening capacity of a lockup clutch according to a predetermined command value, and the command value is A lockup control device for an automatic transmission characterized in that a value corresponding to the release of the lockup clutch is set for a set time after the inertial traveling detection means detects the transition of the vehicle to inertial traveling. . 5. The lockup control device according to claim 4, further comprising a time measuring unit for measuring a time from the end of the control by the inertial traveling lockup capacity control unit to the next inertial traveling, and the measurement time by the unit becomes shorter. A lockup control device for an automatic transmission, wherein the set time for keeping the command value corresponding to the release of the lockup clutch is shortened.

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