JP3541489B2 - Lockup control device for automatic transmission - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a lock-up control device for an automatic transmission in a vehicle, and more particularly to a control device that performs lock-up control at a low temperature.
[0002]
[Prior art]
In order to improve fuel efficiency by improving transmission efficiency, automatic transmissions use a torque converter that locks up directly between input and output elements under conditions where the torque increase function and torque fluctuation absorption function are unnecessary. There is a tendency to switch to a lock-up type that can be brought into a state.
[0003]
In lock-up control of this type of torque converter for promoting warm-up, conventionally, for example, an automatic transmission described in “NISSAN RE4R01A type full-range electronically controlled automatic transmission maintenance manual” (Document 1) issued by the present applicant. As can be seen, until the hydraulic oil temperature of the automatic transmission reaches the set value, lock-up of the torque converter is prohibited, and the torque converter is maintained in a converter state in which the direct connection between the input and output elements is broken. It is customary to promote warming-up by agitation of hydraulic oil by relative rotation of input / output elements.
[0004]
[Problems to be solved by the invention]
However, in such a conventional lock-up control technology for promoting warm-up, the transmission operating oil temperature Ta is monitored as shown in FIG.₁From the time Δt until the transmission working oil temperature Ta reaches the set value Tas._aSince the lock-up of the torque converter is prohibited throughout, the following problems have occurred.
[0005]
That is, regarding the engine cooling water temperature Te also illustrated in FIG. 8A, when the lock-up of the torque converter is performed in a low temperature region lower than a certain engine cooling water temperature set value Tes, unburned harmful substances in the exhaust gas are reduced. It must be avoided because it increases and causes a serious problem in terms of exhaust measures. However, in the high temperature range where the engine cooling water temperature Te is equal to or higher than the set value Tes, it is preferable not to prohibit lock-up of the torque converter in terms of fuel efficiency. . However, in the conventional lock-up control for promoting warm-up, the lock-up of the torque converter is prohibited until the transmission working oil temperature Ta reaches the set value Tas._LThe lockup of the torque converter performed on the condition that_bIs not performed during the period, the lock-up period is shortened accordingly, and improvement in fuel efficiency is hindered.
[0006]
FIG. 8A shows a time-dependent change characteristic when the vehicle is driven before the warm-up is completed at the same time as the start of the engine. If the vehicle is driven after a short period of warm-up operation after start-up, the lock-up inhibition period Δt_aIs longer, the lock-up of the torque converter is better, but the period t is prohibited._b, And the above problem becomes more pronounced.
[0007]
On the other hand, as shown in FIG. 8C, when the set value Tas of the transmission operating oil temperature is reduced, the vehicle is started from before the start of the engine and the completion of the warm-up at the same time as in the case of FIG. 8A. When the vehicle is driven, the lock-up prohibition period Δt_aIs extremely short, and the period Δt during which the lockup should not yet be performed for the exhaust gas countermeasures described above._CLock-up of the torque converter from inside is performed, which is an operation that must be avoided.
[0008]
As apparent from the above, in order to solve the above-described problem, the engine cooling water temperature Te is monitored, and a period until the temperature reaches the set value Tes is determined as a period during which lock-up of the torque converter is to be prohibited to promote warm-up. In this case, a new signal line is required to capture the detection signal of the engine coolant temperature Te, although the engine coolant temperature Te information is not originally used for controlling the automatic transmission. Inevitably suffer from cost disadvantages.
[0009]
In view of the above, the present applicant has previously disclosed in Japanese Patent Application No. 5-32456, although there are some differences depending on the initial cooling water temperature at the time of starting the engine (ENG) and the operating conditions, A substantially constant relation between the integral value of the ENG rotation speed ΣNe and the signal line of the ENG rotation speed Ne is originally present in the control system of the automatic transmission, and the addition of the signal line is added (FIG. 7). Is unnecessary, lock-up control for calculating the ENG rotation speed integral value from the start, detecting the ENG cooling water temperature Te from the ENG rotation speed integral value ΣNe after the start, and performing lock-up control at a low temperature. The device is proposed.
According to this, the ENG cooling water temperature can be indirectly detected based on the ENG rotation speed integral value, and the lock-up prohibition period for promoting the warm-up operation can be determined based on the detected ENG cooling water temperature, thereby eliminating the above-mentioned adverse effects. In addition, this can be realized by indirect monitoring of the ENG cooling water temperature, and there is no cost disadvantage.
[0010]
The above-mentioned proposal can solve all of the various problems and realize an effective lock-up control as compared with the conventional control. Considering that the difference between the indirectly detected ENG cooling water temperature and the actual ENG cooling water temperature may be large and the accuracy may be low depending on the driving environment, driving conditions, etc., there is still room for improvement. The present inventor has found that there is.
If the accuracy is low, the effect of the lock-up control at the low temperature cannot be sufficiently exerted.Therefore, it is more desirable to improve the accuracy with respect to the actual ENG cooling water temperature without losing the advantage of the above proposal, and This is the realization of a control device capable of ensuring the effectiveness of lockup control.
[0011]
The present invention is based on the idea that if the engine coolant temperature is detected based on the integral value (Σq) of the heat release amount (q) of the engine (FIG. 6), the accuracy with respect to the actual engine coolant temperature can be improved. It is an object of the present invention to embody this idea and to provide a more improved lockup control device for an automatic transmission.
[0012]
[Means for Solving the Problems]
According to the present invention, the following lock-up control device for an automatic transmission is provided (FIG. 1).
That is, in a vehicle equipped with an automatic transmission that receives the rotation of the engine through a torque converter that can be locked up and that outputs the rotation after shifting the rotation.
Means for detecting the start of the engine;
Means for determining the amount of heat radiation of the engine;
Means for estimating an engine cooling water temperature based on an integrated value of the engine heat release amount after detecting the engine start, based on information from these means,
Means for controlling to inhibit lock-up of the torque converter during a low temperature until the estimated temperature value by the means reaches a predetermined value;,
Temperature detection means for detecting a temperature representing a hydraulic oil temperature of the automatic transmission at the time of detecting the engine start,
The value of the hydraulic oil temperature detected by the temperature detecting means is corrected as the initial value of the engine coolant temperature, and the estimated temperature value is corrected.
A lock-up control device for an automatic transmission.
[0013]
Further, in the above, the means for obtaining the heat release amount of the engine includes:
Detecting means for detecting a rotational speed indicating the rotational speed of the engine, and detecting means for detecting a throttle opening, and calculating an engine heat radiation amount from the detected rotational speed and the throttle opening;
A lock-up control device characterized in that:
In addition, there is provided storage means for previously obtaining and storing the relationship between the engine speed and the amount of heat radiation with respect to the throttle opening degree,
The heat radiation amount of the engine is obtained by calculation based on the relationship stored in the storage means.
A lock-up control device for an automatic transmission.
[0014]
Also,In a vehicle equipped with an automatic transmission that receives the rotation of the engine through a torque converter that can be locked up and that outputs the rotation after shifting the rotation,
Means for detecting the start of the engine;
Means for determining the amount of heat radiation of the engine;
Means for estimating an engine cooling water temperature based on an integrated value of the engine heat release amount after detecting the engine start, based on information from these means,
Means for controlling to inhibit lock-up of the torque converter while the temperature is low until the estimated temperature value by the means reaches a predetermined value;
Storage means for preliminarily obtaining and storing the relationship between the engine speed and the throttle opening based on the engine speed-engine torque-equal heat radiation amount characteristic and the engine speed-engine torque-throttle opening characteristic; , With
The means for determining the heat radiation amount of the engine includes a detecting means for detecting a rotational speed representing the rotational speed of the engine, and a detecting means for detecting the throttle opening, and the detected engine rotational speed and Based on the detected throttle opening, an engine heat radiation amount is calculated based on a relationship of the engine heat radiation amount with respect to the engine speed and the throttle opening degree stored in the storage means in advance.
A lock-up control device for an automatic transmission.
Further, at the time of detecting the engine start, the apparatus further includes temperature detecting means for detecting a temperature representing a hydraulic oil temperature of the automatic transmission,
The operating oil temperature value detected by the means is used as an initial value of the engine cooling water temperature to correct the estimated temperature value,
A lock-up control device for an automatic transmission.
[0015]
[Action]
With the configuration described above, in the present invention, the torque converter transmits the engine rotation to the automatic transmission in a lockup state in which the input and output elements are directly connected or in a converter state in which the direct connection is released, and Detects the start of the engine of the vehicle as described in claim 1, obtains a heat radiation amount of the engine, and estimates an engine cooling water temperature. And prohibiting lock-up of the torque converter to promote warm-up while the temperature is low until the estimated temperature value reaches a predetermined value. Is possible.
[0016]
Therefore, in the case of lock-up control at low temperatures, it is possible to properly estimate the engine cooling water temperature from the integrated value of the engine heat radiation and detect it indirectly as a more accurate one, improving the accuracy with respect to the actual engine cooling water temperature. I do.
Based on this, the lock-up prohibition period for promoting the warm-up operation is accurately determined, and the torque converter is locked up more precisely during this period according to the actual condition of the engine cooling water temperature. It should not be necessary to properly match the engine coolant temperature range, thereby improving the responsiveness and ensuring that the torque converter locks up during any operating state when the torque converter should not be locked up for exhaust measures Even if the torque converter should not be locked up for a long period of time despite the fact that it should be locked up without causing the problem of exhaustion, the torque converter will not be locked up for a long time, and the fuel efficiency improvement effect will be diminished. And it is possible to ensure the effectiveness of the control. Moreover, since such an effect is achieved by indirect monitoring of the engine cooling water temperature based on the engine heat radiation amount, the effect can be obtained without adding a signal line of the engine cooling water temperature, resulting in cost disadvantage. Without making it possible to achieve the above.
[0017]
Then, a temperature representing the operating oil temperature of the automatic transmission at the time of engine start detection is detected, and the estimated temperature value is corrected based on the detected value, using the value of the operating oil temperature as the initial value of the engine cooling water temperature. By such a correction, the accuracy of the estimation is further increased, and the control accuracy is enhanced. In addition, even in this case, a signal line for the transmission operating oil temperature is originally present in the control system of the automatic transmission, and it is not necessary to add a signal line. There is no need for hardware addition or change such as addition of a signal line, or software change, and it is even more preferable in terms of hardware and software.
[0018]
Preferably, in this case, in order to obtain the heat radiation amount of the engine, each of the detecting means for detecting the rotational speed indicating the rotational speed of the engine and detecting the throttle opening is used to determine the detected rotational speed. The present invention can be suitably implemented as a configuration for calculating the engine heat radiation amount from the number and the throttle opening, and similarly, the above can be realized. In this case, the throttle opening information is required in addition to the rotation speed information. This throttle opening is already existing as information to be taken in for the shift control in the automatic transmission. The line is also originally present in the control system of the automatic transmission, and it is not necessary to separately add a new signal line, etc., so that it can be easily implemented without incurring a cost disadvantage. It becomes more suitable. It should be noted that it is preferable to use the engine speed itself as the engine speed indicating the engine speed, in order to further ensure the above-described operation and effect, and also to use the information as information in the engine start detection. Since the engine speed information can be easily used for a series of processes such as calculating the engine heat radiation amount and estimating the engine cooling water temperature based on the integral value of the engine heat radiation amount, this point is even more effective. is there.
[0019]
Further, as in the case of the third aspect, there is provided storage means for previously obtaining and storing the relationship of the engine heat radiation amount with respect to the engine speed and the throttle opening, and the engine heat radiation amount is stored in the storage means. The present invention can be suitably implemented by being configured to be obtained by calculation based on the relation, and also enables the above to be realized. In this case, in addition to the above, for example, a map of the engine speed, the throttle opening, and the engine heat amount stored in advance in the memory is used. Can be obtained by calculation, and the contents of the calculation processing and the like can be simplified.
[0020]
Further, each of the means for detecting the start of the engine of the vehicle, obtaining the heat radiation amount of the engine, estimating the engine cooling water temperature, and controlling to inhibit the lock-up is provided. During the low temperature until the estimated temperature value reaches the predetermined value, the lock-up of the torque converter is prohibited to facilitate warm-up, and the amount of engine heat radiation with respect to the engine speed and the throttle opening can be increased. A storage means for obtaining and storing the relationship in advance, so that the engine heat radiation amount is obtained by calculation based on the relationship stored in the storage means, and a rotation speed representing the rotation speed of the engine is detected; and By using each detecting means for detecting the throttle opening and calculating the engine heat radiation amount from the detected rotation speed and the throttle opening, the lockup of the automatic transmission is achieved. The control, without incurring the disadvantage of cost, and which may be implemented more effectively. In addition, as described in claim 5, a temperature representing the operating oil temperature of the automatic transmission at the time of engine start detection is detected, and the detected operating oil temperature value is used as an initial engine cooling water temperature to correct the estimated temperature value. By doing so, the control accuracy can be improved, and there is no need for hardware additions or changes such as the addition of new signal lines, or software changes. It becomes suitable.
[0021]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 2 shows a lock-up control device for an automatic transmission according to one embodiment of the present invention. In the figure, 1 is an engine (ENG) and 2 is an automatic transmission (A / T). The automatic transmission 2 receives the power of the engine 1 via the torque converter 3, changes the input rotation at a gear ratio according to the selected shift speed, and transmits the input rotation to the output shaft 4.
[0022]
Here, in the automatic transmission 2, the selected shift stage is determined by the combination of ON and OFF of the shift solenoids 6 and 7 in the control valve 5, and the torque converter 3 turns ON and OFF of the lock-up solenoid 8 in the control valve 5. Accordingly, power transmission is performed in a lockup state in which the input / output elements are directly connected or in a converter state in which the direct connection is released.
[0023]
The ON and OFF of the shift solenoids 6 and 7 and the ON and OFF of the lock-up solenoid 8 are controlled by a controller 9. The controller 9 receives a signal from an engine rotation sensor 10 that detects the rotation speed Ne of the engine 1. A signal, a signal from a throttle opening sensor 11 for detecting a throttle opening TH of the engine 1, a signal from a vehicle speed sensor 12 for detecting a vehicle speed V from the rotation speed of the transmission output shaft 4, and a hydraulic oil for the automatic transmission 2. A signal from the oil temperature sensor 13 for detecting the temperature Ta is input.
[0024]
The controller 9 includes an input detection circuit, an arithmetic processing circuit, a control program such as a shift control program and a lock-up control program executed by the arithmetic processing circuit, a storage circuit for storing arithmetic results and the like, a shift solenoid 6, 7 and an output circuit for sending a control signal to the lock-up solenoid 8. Based on the input information, the following shift control and normal lock-up control are performed by well-known calculations. That is, first, the shift control will be described. First, the optimum gear position for the current driving state is obtained from the throttle opening TH and the vehicle speed V by, for example, a table lookup method, and the shift solenoid 6 is selected so that the optimum gear position is selected. , 7 are turned ON and OFF to perform a predetermined shift. Next, the normal lock-up control will be described. In the lock-up region where the torque increasing function and the torque fluctuation absorbing function by the torque converter 3 are not necessary based on the throttle opening TH and the vehicle speed V for each specific gear or each gear. It is determined whether the motor is operating in the converter area where these functions are required or not, and in the lock-up area, the lock-up solenoid 8 is turned on to bring the torque converter 3 into a lock-up state in which the input and output elements are directly connected. In the converter region, the lock-up solenoid 8 is turned off to bring the torque converter 3 into the converter state in which the direct connection is released.
[0025]
The controller 9 performs a lock-up control for promoting warm-up, in addition to the normal lock-up control, based on the control program shown in FIGS. This control program is started at step 21 (FIG. 3) when the ignition switch is turned on to start the engine, and is thereafter repeatedly executed at step 22 by, for example, a regular interruption every 0.1 seconds.
[0026]
At the start of the program in step 21, the following initial settings are made.
This start flag is OFF.
Engine speed Ne: 0 rpm
Previous start determination flag OFF
Lockup prohibition flag ON
Engine heat radiation integrated value Σq ... 0
[0027]
In step 23, the engine speed Ne and the throttle opening TH are read, and in the next step 24, it is checked whether the engine has been started or not based on whether or not the previous start determination flag is ON. If the engine has not been started, it is determined in step 25 whether or not the engine has been started based on whether or not the engine speed Ne is, for example, 800 rpm or more. At the time of starting when Ne ≧ 800 rpm, at step 26, the present start determination flag is turned ON to indicate this, and the process proceeds to step 31 and subsequent steps.
[0028]
If it is determined in step 24 that the engine has been started, it is determined in step 27 whether or not the engine stall (stalled) based on whether or not the engine speed Ne is, for example, 200 rpm or less. If not, the process proceeds directly to step 31. If the engine stalls, the current start determination flag is turned off in step 28, the lock-up prohibition flag is turned on in step 29, the timer is set in step 30, and the process proceeds to step 31 and subsequent steps.
[0029]
In step 31, it is checked whether or not the instant of engine start has been reached, based on whether or not the previous engine start determination flag is OFF and the current engine start determination flag is ON. Steps 32 and 33 are executed only once at the moment of starting the engine.34Proceed to (FIG. 4). When these steps 32 and 33 are executed, the transmission operating oil temperature Ta (= Tα) at the instant of the start is read, and the present start determination flag is set to the previous start determination flag for the next control. Is done. Here, the read oil temperature value Tα in step 32 is used to correct the engine cooling water temperature initial value = A / T oil temperature initial value, and thus is obtained at the moment of starting the engine.
[0030]
Steps34Hereinafter, the ENG water temperature sensor is not used, and the ENG water temperature is detected (estimated) based on the engine heat radiation amount q to perform lockup control at low temperature. Therefore, in the present program example, the following processing is executed.
First, step34In step (3), based on the engine speed Ne and the throttle opening TH read in step 23, for example, a heat radiation amount q (Ne, TH) of the engine 1 is obtained from a map having characteristics as shown in FIG.
[0031]
Thus, the engine heat radiation amount q is calculated from the engine speed Ne and the throttle opening TH, and then step35To calculate the integral value Σq of the engine heat release amount q from the engine start.36, A value f (Σq) corresponding to the integral value Σq is obtained, and a value obtained by adding the value f (Σq) to the read value Tα of the transmission working oil temperature, that is, f (Σq) + Tα, is calculated. It is checked whether or not the obtained sum value f (Σq) + Tα is equal to or more than a target temperature value T1 (a target value of a temperature set when performing the lockup control at a low temperature).
[0032]
Here, the above processing is performed based on the following knowledge of the inventor.
The heat release amount (q) of ENG is determined by the ENG rotation speed Ne and the throttle opening TH as shown in FIG.
The relationship between the ENG rotation speed Ne and the ENG torque that exhibits the same heat radiation amount q (engine heat radiation amount) is represented by an equal heat radiation amount line as shown in FIG. Further, the relationship between the ENG rotation speed Ne and the ENG torque in the case of the same throttle opening TH is represented by an equal TH opening line as shown in FIG. These show the ENG rotation speed Ne-ENG torque-equal heat radiation amount line characteristic and the ENG rotation speed Ne-ENG torque-equal TH opening degree line characteristic, respectively. As a result, the ENG heat radiation amount q characteristic Can be based on the ENG rotation speed Ne and the throttle opening TH with respect to the ENG rotation speed Ne and the throttle opening TH as shown in FIG. TH can be determined as a parameter.
In this case, the throttle opening TH signal is necessary to check the heat release amount of ENG, but as will be described later, the signal line of the throttle opening TH is connected to the control system of the automatic transmission for the original control. Originally exists, and therefore, it is not necessary to add a new signal line to the automatic transmission control unit (A / TCU), and the throttle opening TH information exists in the control unit. What is read from the A / TCU can be used as it is.
[0033]
Therefore, here, according to the characteristic tendency, the Ne, TH, and q data are stored in advance as map data in the memory of the storage circuit of the controller 9 as the storage means, and the Ne-TH-q map is used. Using the above-mentioned read engine speed Ne and throttle opening TH information originally used in the control system of the automatic transmission,34Accordingly, a corresponding engine heat radiation amount q can be obtained according to the engine speed Ne and the throttle opening TH at that time (step34).
[0034]
On the other hand, focusing on the temperature rise up to a certain time t, the temperature rise ΔT is expressed by the following equation:
(Equation 1)
Q = ∫qdt = Σq 1
(However, the integral ∫ is the integral from 0 to t)
By being
(Equation 2)
ΔT = f (Q) 2
It becomes.
[0035]
Further, assuming that the temperature after the lapse of the time t is T, the temperature T is obtained by adding a value ΔT of the rise to the initial temperature value.
(Equation 3)
T = ΔT + initial temperature ... 3
It is.
Therefore, if the water temperature initial value is corrected as the A / T oil temperature initial value (if the temperature value representing the operating oil temperature of the automatic transmission 2 at the time of starting is regarded as the water temperature initial value (see FIG. 8)), Equation 3 is
(Equation 4)
T = ΔT + A / T Initial oil temperature Ta... 4
Is represented by
[0036]
Therefore, from these equations, the temperature T value can be calculated as36As the sum of the right-hand side of
(Equation 5)
T = f (Σq) + Tα 5
Can be led as
Here, f (Σq) (= f (Q)) is a temperature conversion value relating to the heat radiation amount of the engine 1, and f (Σq) + Tα is a value obtained by using a hydraulic oil temperature value obtained from the oil temperature sensor 13. A value corresponding to the corrected temperature after the above correction is performed, that is, an estimated value of the cooling water temperature of the engine 1 obtained by estimating the engine speed Ne, the throttle opening TH, and the transmission working oil temperature Ta. become.
[0037]
Therefore, in this example of the program, it is monitored whether or not f (Σq) + Tα ≧ T1, and37In the following, with respect to the temperature T according to the above equation 5, when the temperature becomes equal to or higher than a predetermined target temperature T1 set in advance, the lock-up prohibition is released. If the temperature does not reach the target temperature T1, the lock-up prohibition is maintained. Control.
[0038]
That is, as long as f (Σq) + Tα ≧ T1 is not satisfied and the temperature is lower than the set target temperature, step37Is skipped and the lock-up prohibition flag is kept in the ON state in step 21 or step 29, thereby prohibiting lock-up as described later.
On the other hand, when f (Σq) + Tα ≧ T1 is satisfied and the temperature becomes equal to or higher than the target temperature, step37To turn off the lock-up prohibition flag, thereby releasing the lock-up prohibition.
[0039]
Steps38Then, the lock-up prohibition flag is checked.39Then, the normal lock-up control described above and the normal shift control described above, such as obtaining the optimum gear position for the current driving state from the throttle opening TH and the vehicle speed V, are executed, and the lock-up prohibition flag is turned ON. In the lock-up prohibited state,40, Lock-up is prohibited, and only the normal shift control described above is executed.
[0040]
According to the above control, from the time when the start of the engine 1 is detected, the corrected temperature equivalent value T (= f (推定 q) + Tα) as the indirectly detected estimated engine coolant temperature value is set to the set target temperature. Until the value T1 is reached, lock-up of the torque converter 2 is prohibited, and the prohibition causes the torque converter 2 to transmit power by relative rotation between the input and output elements. Stir to promote warm-up. After the corrected temperature equivalent value T reaches the target temperature value T1, the lock-up prohibition is released, and the lock-up control of the torque converter 2 can be performed as usual.
[0041]
Therefore, as in the case of the applicant's earlier application, the engine cooling water temperature is indirectly detected from the engine speed integrated value after the start, and the lock-up control at low temperature is detected. When the difference between the cooling water temperature and the actual engine cooling water temperature is large and the difference between the actual value and the actual value is large, the accuracy is worsened and the accuracy is more difficult to secure, but such disadvantages are avoided. In the same low temperature lock-up control, the actual engine cooling is calculated by calculating the engine heat radiation amount q from the engine speed Ne and the throttle opening TH, and detecting the engine cooling water temperature from the integrated value Σq of the engine heat radiation amount q. The accuracy for the water temperature is improved. As a result, the lock-up control can be made accurate accordingly, and its effectiveness can be further improved.
[0042]
Therefore, even when the vehicle is driven at the same time as the engine start as shown in FIG. 8 or when the vehicle is driven after the warm-up operation, in the case of the earlier application, the responsiveness can be increased as compared with the conventional control described above. The lock-up prohibition can be canceled at a timing as close as possible to the timing when the engine cooling water temperature Te reaches the target lower limit value Tes. Therefore, during the period of Te <Tes during which the torque converter should not be locked up in the exhaust gas countermeasures. It is possible to prevent the torque converter from being locked up, and to perform a period Δt during which the torque converter is not locked up despite the period of Te ≧ Tes to be locked up._bIn this control, the effect of the earlier application can be achieved, and the effect can be further improved. In comparison, the accuracy with respect to the actual engine cooling water temperature is improved, the engine cooling water temperature can be estimated more accurately, the effect can be further improved, and further improved lockup control can be achieved.
[0043]
In this case, in the above-described example, the method of obtaining the engine heat radiation amount from the Ne-TH-q data map was employed as described above, but instead, the method of FIG. 5A and FIG. It is also possible to execute the calculation based on the respective characteristic relations and to indirectly calculate the engine heat radiation amount q to obtain the finally calculated value. Therefore, this is not prevented, but in particular, the throttle opening TH and the engine speed Ne are used as two parameters, and the detected engine torque value (or the estimated engine torque value) is used without intervening as a use control parameter. If the engine heat radiation amount q is calculated and obtained directly from the two parameters using the Ne-TH-q map, the content of the calculation processing and the like can be simplified accordingly, and another parameter besides the engine speed Ne information can be obtained. Even if the throttle opening TH information is required, the signal line of the throttle opening TH also originally exists in the control system of the automatic transmission, and the addition of the signal line is unnecessary. These points are also more preferable.
[0044]
Further, if the transmission operating oil temperature initial value Tα is corrected according to the above-described equations (4) and (5), the correction further increases the accuracy of the estimation and the control accuracy, and even in this case, The signal line of the transmission operating oil temperature Ta originally exists in the control system of the automatic transmission, and the addition of the signal line is unnecessary. Therefore, similarly to the above, a hardware addition or change such as adding a new signal line separately, and an arithmetic process for calculating temperature data from the electric signal from the oil temperature sensor 13 are newly added to the program. There is no need for software change such as incorporation, and the hardware and software are more preferable.
[0045]
【The invention's effect】
According to the present invention, it is possible to appropriately estimate the engine cooling water temperature from the integrated value of the engine heat release amount, indirectly detect the temperature as more accurate, and improve the accuracy with respect to the actual engine cooling water temperature, Therefore, in the case of the lock-up control at the time of low temperature, the lock-up prohibition period for promoting the warm-up operation can be accurately determined, and this period can be more accurately determined in accordance with the actual condition of the engine cooling water temperature, and When the torque converter should not be locked up, it can be properly matched to the engine coolant temperature range, thereby increasing the responsiveness and ensuring that the torque converter should not be locked up for exhaust measures in any operating state. The torque converter is locked up even if the torque converter is locked up It is possible to effectively eliminate such adverse effects that the fuel economy improvement effect is weakened without being locked up over time, and the effectiveness of the control can be secured, and an improved lock-up control is realized. be able to.
Moreover, this operation and effect can be achieved without adding a signal line for the engine cooling water temperature, and there is no disadvantage in cost.
[0046]
Preferably, if the heat radiation amount of the engine is obtained as described in claim 2, the present invention can be suitably implemented, and the same can be realized. In this case, in addition to the rotational speed information, the throttle opening information is required. Such a throttle opening is already existing as information to be taken in for the shift control in the automatic transmission. Since the control system of the automatic transmission originally exists and does not require the addition of a new signal line or the like, it can be easily implemented without incurring a disadvantage in cost. It becomes suitable.
[0047]
In this case, it is preferable to use the rotation speed of the engine itself as the rotation speed representing the engine rotation speed in order to further ensure the above-described operation and effect, and can be applied as information for engine start detection. Since the engine speed information can be easily used for a series of processes such as calculating the engine heat radiation amount and estimating the engine cooling water temperature based on the integral value of the engine heat radiation amount, this point is even more effective. It is.
[0048]
Further, the invention can be suitably implemented as a configuration for correcting the initial value of the water temperature based on the operating oil temperature value of the automatic transmission at the time of detecting the start of the engine, and the same can be realized. Further, in this case, the correction further increases the accuracy of the estimation and the control accuracy. In addition, even in this case, a signal line for the transmission operating oil temperature is originally present in the control system of the automatic transmission, and it is not necessary to add a signal line. There is no need for hardware addition or change such as addition of a signal line, or software change, and it is even more preferable in terms of hardware and software.
[0049]
The present invention can be suitably implemented by being configured as in the case of claim 4, and the above can be realized similarly. In this case, in addition to the above, for example, a map of the engine speed, the throttle opening, and the engine heat amount stored in advance in the memory is used. Can be obtained by calculation, and the contents of the calculation processing and the like can be simplified.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a lock-up control device for an automatic transmission according to the present invention.
FIG. 2 is a system diagram showing one embodiment of a lockup control device for an automatic transmission according to the present invention.
FIG. 3 is a flowchart showing a part of an example of a lock-up control program for promoting warm-up executed by a controller in the same example.
FIG. 4 is a flowchart showing another part.
FIG. 5 is a diagram for explaining a method of calculating an engine heat radiation amount applicable to the program, and is a diagram illustrating a case of obtaining a map from an engine speed and a throttle opening.
FIG. 6 is a diagram for explaining a relationship between an engine heat radiation amount and an actual engine cooling water temperature.
FIG. 7 is a diagram illustrating a relationship between an engine speed and an actual engine coolant temperature, as a comparative example.
FIG. 8 is a time chart showing a lock-up prohibition period in a case where a vehicle equipped with a conventional lock-up control device is driven at the same time as the start of the engine, together with a relationship between an engine cooling water temperature, a transmission operating oil temperature, and a vehicle speed. (A) Similarly, a time chart (b) showing the lock-up prohibition period when the vehicle is driven after the warm-up operation together with the relationship between the engine cooling water temperature, the transmission hydraulic oil temperature, and the vehicle speed, and the transmission. A time chart showing the lock-up prohibition period when the set value of the hydraulic oil temperature is reduced and the vehicle is driven under the same conditions as (a), together with the relationship between the engine cooling water temperature, the transmission hydraulic oil temperature, and the vehicle speed ( c).
[Explanation of symbols]
1 engine
2 Automatic transmission (A / T)
3 Torque converter
5 Control valve
6 shift solenoid
7 Shift solenoid
8 Lock-up solenoid
9 Controller
10. Engine (ENG) rotation sensor
11 Throttle opening sensor
12 Vehicle speed sensor
13 Oil temperature sensor

Claims (5)

In a vehicle equipped with an automatic transmission that receives the rotation of the engine through a torque converter that can be locked up and that outputs the rotation after shifting the rotation,
Means for detecting the start of the engine;
Means for determining the amount of heat radiation of the engine;
Means for estimating an engine cooling water temperature based on an integrated value of the engine heat radiation amount after detecting the engine start based on information from these means,
Means for controlling to inhibit lock-up of the torque converter while the temperature is low until the estimated temperature value by the means reaches a predetermined value ;
Temperature detection means for detecting a temperature representing a hydraulic oil temperature of the automatic transmission at the time of detecting the engine start,
The value of the hydraulic oil temperature detected by the temperature detecting means is corrected as the initial value of the engine coolant temperature, and the estimated temperature value is corrected.
A lock-up control device for an automatic transmission. The means for determining the heat radiation amount of the engine includes:
Detecting means for detecting a rotational speed indicating the rotational speed of the engine, and detecting means for detecting a throttle opening, wherein an engine heat radiation amount is calculated from the detected rotational speed and the throttle opening.
The lock-up control device for an automatic transmission according to claim 1, wherein: Storage means for obtaining and storing in advance the relationship between the engine heat release amount and the engine speed and the throttle opening,
The heat radiation amount of the engine is obtained by calculation based on the relationship stored in the storage means.
The lock-up control device for an automatic transmission according to claim 1 or 2, wherein: In a vehicle equipped with an automatic transmission that receives the rotation of the engine through a torque converter that can be locked up and that outputs the rotation after shifting the rotation,
Means for detecting the start of the engine;
Means for determining the amount of heat radiation of the engine;
Means for estimating an engine cooling water temperature based on an integrated value of the engine heat release amount after detecting the engine start, based on information from these means,
Means for controlling to inhibit lock-up of the torque converter while the temperature is low until the estimated temperature value by the means reaches a predetermined value;
Storage means for previously obtaining and storing the relationship between the engine speed and the throttle opening based on the engine speed-engine torque-equal heat radiation amount characteristic and the engine speed-engine torque-throttle opening characteristic; , With
The means for determining the heat radiation amount of the engine includes a detecting means for detecting a rotational speed representing a rotational speed of the engine, and a detecting means for detecting a throttle opening. Based on the detected throttle opening, an engine heat radiation amount is calculated based on a relationship of the engine heat radiation amount with respect to the engine speed and the throttle opening previously stored in the storage means.
A lock-up control device for an automatic transmission. At the time of the detection of the engine start, further comprising a temperature detecting means for detecting a temperature representing the operating oil temperature of the automatic transmission,
The operating oil temperature value detected by the means is used as an engine cooling water temperature initial value to correct the estimated temperature value,
The lock-up control device for an automatic transmission according to claim 4, wherein:

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