JP3691614B2 - Transmission control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission control device, and more particularly to a technique for preventing temperature rise of transmission oil in a transmission with a torque converter.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an automatic transmission configured to transmit engine generated torque to a transmission via a torque converter, ATF deterioration due to temperature increase of automatic transmission oil (hereinafter referred to as ATF), friction element, and seal member deterioration. As a method for preventing the above, when the temperature of the ATF exceeds the allowable temperature or when the temperature is likely to exceed the allowable temperature, the lock-up area of the lock-up clutch provided in the torque converter is expanded to increase the torque. There has been a method of reducing the amount of heat generated by the slip of the converter, thereby suppressing the temperature rise of ATF (Japanese Patent Laid-Open Nos. 62-205829, 62-209265, and 5-302671). (See publications).
[0003]
[Problems to be solved by the invention]
However, for example, when the vehicle is traveling on an uphill, the vehicle speed decreases, the foot is released from the accelerator, and the gear shift is frequently performed. Therefore, even if the lockup area is widened, the lockup area remains long. However, it is difficult to reliably prevent the temperature rise of ATF.
[0004]
In addition, when the control unit for controlling the shifting operation and lockup of the automatic transmission is integrally provided in the case of the transmission, the temperature rise of the ATF is further suppressed to protect the electronic components. Although it is necessary, it is difficult to suppress the temperature rise of the ATF sufficiently and sufficiently only by expanding the lockup region.
[0005]
The present invention has been made in view of the above problems, and even when the control unit is integrally provided in the transmission case, the temperature of the ATF can be reliably suppressed within the allowable temperature. The purpose is to do.
[0006]
[Means for Solving the Problems]
Therefore, the invention according to claim 1 is a control device for a transmission with a torque converter, the oil temperature detecting means for detecting the oil temperature of the transmission or a temperature correlated with the oil temperature, and the oil temperature detecting means. When the detected temperature is equal to or higher than a predetermined temperature, the generated torque reducing means for continuously reducing the generated torque of the engine, and the generated torque of the engine is continuously reduced by the generated torque reducing means A lockup area expanding means for expanding a lockup area of a lockup clutch provided in the torque converter more than usual, an instantaneous heat generation amount calculating means for calculating an instantaneous heat generation amount in the torque converter, and an instantaneous heat generation calculation Integrating means for integrating the amount of instantaneously generated heat calculated by the means for a predetermined time; the temperature detected by the oil temperature detecting means; and the integral value in the integrating means Configured to include a, a torque reduction amount setting means for setting a torque-down amount in the generated torque reducing means on the basis of.
[0007]
According to this configuration, the engine torque is reduced and the lock-up (mechanical direct connection between the input side and output side of the torque converter) is performed at the same time. Plan.
[0008]
Also, when the integrated value of the generated heat is large and a sudden temperature rise is expected, even if the oil temperature at that time is low, the torque reduction amount is determined to reduce the generated torque of the engine, and the oil Control can be performed to suppress the temperature rise before the temperature exceeds the allowable temperature.
[0009]
According to a second aspect of the present invention, a warning means is provided to warn the driver that the generated torque of the engine is continuously reduced by the generated torque reducing means.
[0010]
According to such a configuration, when the generated torque of the engine is forcibly reduced to lower the oil temperature of the torque converter, the driver is warned of the execution state of such control by, for example, lighting of a warning light or a buzzer. Can be recognized.
[0011]
The temperature correlated with the oil temperature is, for example, the oil ambient temperature or the transmission case temperature. Further, the automatic transmission may be configured such that a control unit for controlling a shifting operation and lockup is integrally provided in a case of the transmission.
[0012]
【The invention's effect】
According to the first aspect of the invention, the temperature of the oil in the transmission is reduced by both reducing the torque generated by the engine and expanding the lockup region of the lockup clutch. Even when the control unit is provided integrally with the transmission, the oil temperature can be controlled low enough to protect the electronic components of the control unit.
[0013]
Also, when the integrated value of the generated heat is large and a sudden temperature rise is expected, even if the oil temperature at that time is low, the torque reduction amount is determined to reduce the generated torque of the engine, and the oil Control can be performed to suppress the temperature rise before the temperature exceeds the allowable temperature, thereby preventing the temperature from exceeding the allowable temperature or greatly exceeding the allowable temperature.
[0014]
According to the second aspect of the present invention, the driver can recognize that the engine generated torque reduction control for lowering the oil temperature of the transmission is being executed, and therefore the generated torque is reduced by the reduction control. It is possible to avoid misidentifying that is due to an engine failure.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. FIG. 1 is a system configuration diagram showing an embodiment of a transmission control apparatus according to the present invention.
[0016]
Here, the torque of the internal combustion engine 1 mounted on the vehicle (not shown) is transmitted to the drive wheels (not shown) via the automatic stepped transmission 2, and the automatic stepped transmission 2 is locked. Torque is transmitted to the gear transmission through a torque converter having an up clutch.
[0017]
The transmission may be configured to transmit engine torque to the continuously variable transmission via a torque converter.
[0018]
A throttle valve 4 that is opened and closed by a motor 3 is interposed in the intake passage of the internal combustion engine 1, and the intake air amount of the engine 1 is adjusted by the opening degree of the throttle valve 4.
[0019]
The motor 3 is operated by a control signal from a throttle control module (hereinafter referred to as TCM) 5.
[0020]
The TCM 5 receives an accelerator opening signal ACC from an accelerator opening sensor 9 that detects the amount of depression of an accelerator pedal operated by a driver, and sets a target throttle valve opening TVOta according to the accelerator opening ACC. The motor 3 is feedback-controlled so that the actual throttle valve opening TVO detected by the throttle sensor 6 matches the target throttle valve opening TVOta.
[0021]
On the other hand, an automatic transmission control unit (hereinafter referred to as “A / TC / U”) 7 for controlling the shift operation and lockup of the automatic stepped transmission 2 controls the hydraulic pressure of the automatic stepped transmission 2. It is integrally provided in the case of the automatic stepped transmission 2 together with various solenoid valves that operate and a power transistor that drives the solenoid valve.
[0022]
The A / TC / U 7 includes a rotation speed sensor for detecting a vehicle speed signal VSP from the vehicle speed sensor 8, an accelerator position signal ACC from the accelerator position sensor 9, and a rotational speed Ne (rpm) of the engine 1. An engine speed signal Ne from 10 and an oil temperature signal Tatf from an oil temperature sensor 11 (oil temperature detecting means) for detecting the temperature of oil (hereinafter referred to as ATF) of the automatic stepped transmission 2 are input. It has come to be.
[0023]
The A / TC-U 7 performs automatic shift control and lockup control based on the various signals, and the oil temperature Tatf exceeds the allowable temperature as shown in the flowchart of FIG. The control which suppresses is performed.
[0024]
In the present embodiment, the A / TC / U 7 functions as generated torque reducing means, lockup area expanding means , torque down amount setting means, instantaneous heat generation amount calculating means, and integrating means . As shown in the flowchart of FIG.
[0025]
In the flowchart of FIG. 2, first, in step 1 (denoted as S1 in the figure, the same applies hereinafter), the ATF oil temperature Tatf detected by the oil temperature sensor 11 is read.
In step 2, the oil temperature Tatf read in step 1 is compared with a predetermined temperature (allowable temperature) ts. When the current oil temperature Tatf is lower than the predetermined temperature ts, this routine is terminated as it is. However, when the current oil temperature Tatf is equal to or higher than the predetermined temperature ts, the routine proceeds to step 3.
[0026]
In step 3, in order to reduce the oil temperature Tatf by forcibly reducing the generated torque of the engine 1, the torque down amount is set as shown in FIG.
[0027]
In FIG. 3, first, an instantaneous heat generation amount Q in the torque converter is obtained from the engine speed Ne and the engine generated torque Te (instantaneous heat generation calculating means). The engine generated torque Te can be represented by a throttle opening, a cylinder intake air amount, or the like.
[0028]
Next, the instantaneous heat generation amount Q is integrated for a predetermined time (integration means), and the torque reduction amount is determined based on the integrated value of the heat generation amount Q and the oil temperature T atf detected by the oil temperature sensor 11. (Torque down amount setting means).
[0029]
When the integral value is large and a rapid temperature increase is expected, even if the oil temperature T atf at that time is low, a torque reduction amount is determined to reduce the generated torque of the engine, and the oil temperature T Control to suppress the temperature rise before atf exceeds the allowable temperature.
[0030]
The instantaneous calorific value Q can be calculated by the following equation as a loss in the torque converter.
[0031]
Q = K · Ne · Te · (1-η)
[0032]
Here, K is a constant, Ne is the engine speed ( rpm ), Te is the engine generated torque, and η is the efficiency of the torque converter. Further, since the engine generated torque Te can be regarded as Te = k × Qa / Ne (k is a constant) when the intake air flow rate of the engine is Qa, the instantaneous calorific value Q is Q = K ′ · It can be calculated as Qa · (1−η).
[0033]
Further, simply, a map is provided in which the instantaneous heat generation amount Q is stored in advance according to the engine speed Ne and the throttle opening (or the cylinder intake air amount Qa / Ne), and the instantaneous heat generation amount Q is determined by referring to the map. You can ask for it.
[0034]
As shown in FIG. 4, the generated torque Te of the engine 1 and the rotational speed Ne of the engine 1 affect the heat generation amount of the torque converter, and the heat generation amount increases as the generated torque increases. reduces the heating value of the torque converter, I following, in which the oil temperature of the transmission can be reduced.
[0035]
In the next step 4, the torque down amount set in step 3 is transmitted to the TCM 5. In TCM5, the normal target throttle valve opening TVOta corresponding to the accelerator opening is corrected to decrease according to the torque reduction amount, and the opening of the throttle valve 4 is adjusted based on the target throttle valve opening TVOta after the correction. Control.
[0036]
As a result, while the oil temperature Tatf exceeds the predetermined temperature, the intake air amount of the engine 1 is forcibly reduced, and thereby the torque generated by the engine 1 is continuously reduced, so that the oil temperature Tatf is reduced. Reduction to a predetermined temperature or less is achieved.
[0037]
Further, in the next step 5, the third speed is set to the highest speed shift stage, so that the first speed to the third speed on the low speed side is limited without using the first speed to the fourth speed which is the normal speed range. To perform automatic gear shift control.
[0038]
As a result, according to the normal shift schedule, in the driving condition of shifting to the fourth speed, the gear is shifted down to the third speed, and the shift down is a direction in which the rotation increases and the generated torque decreases. Since it becomes control (refer FIG. 4) , the emitted-heat amount in a torque converter will reduce.
[0039]
Accordingly, the combined use of the torque down control in Steps 3 and 4 and the shift down control in Step 5 makes it possible to generate more heat in the torque converter than when only the torque down control in Steps 3 and 4 is performed. As a result, the oil temperature Tatf can be quickly lowered, the ATF can be prevented from being deteriorated, and the A / TC / U7 provided integrally with the transmission 2 can be protected. .
[0040]
In step 6, it is determined whether or not the vehicle speed VSP at that time exceeds a predetermined vehicle speed. If the vehicle speed VSP is equal to or higher than the predetermined vehicle speed, the process proceeds to step 7 to execute lockup of the lockup clutch provided in the torque converter. Let
[0041]
In normal lock-up control, the fourth speed is a condition for lock-up, but shifting to the fourth speed is prohibited as described above. Therefore, the lock-up control is performed at a speed other than the fourth speed (third speed). This means that lockup is performed, which corresponds to the expansion of the lockup area.
[0042]
When the lockup is performed, the input side and the output side of the torque converter are mechanically directly connected, so that heat generation due to slippage of the torque converter can be avoided.
[0043]
Further, when the vehicle speed is low and lockup cannot be performed, the amount of heat generated by the torque converter is suppressed by the processing in steps 3 to 5 described above.
[0044]
It should be noted that when the oil temperature Tatf is high, the lockup region is expanded, and only when the oil temperature Tatf is out of the expanded lockup region, control to reduce the torque generated by the engine 1 or forced downshift control (maximum (Prohibition of shifting to high speed) may be performed.
[0045]
Further, in step 8, in order to make the driver recognize that the engine generated torque reduction control for reducing the oil temperature Tatf and the shift to the maximum speed are prohibited, for example, in the instrument part of the driver's seat. The provided warning lamp 12 is turned on (warning means).
[0046]
As a result, it is possible to prevent the driver from misidentifying the engine malfunction and the generated torque reduction control for lowering the oil temperature.
[0047]
In the above embodiment, the intake air amount of the engine is reduced by reducing the opening of the throttle valve, thereby reducing the generated torque of the engine. However, for example, the ignition timing is retarded. or, and or to lean air-fuel ratio, it may be configured to reduce the torque of the engine 1.
[0048]
Moreover, it is good also as a structure which detects the temperature of the atmosphere of ATF, and the temperature of the case of the transmission 2 instead of detecting the oil temperature Tatf.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a transmission according to an embodiment.
FIG. 2 is a flowchart showing the contents of oil temperature control in the embodiment.
FIG. 3 is a block diagram showing a torque down amount setting process based on an integrated value of instantaneous heat generation amount.
FIG. 4 is a diagram showing the correlation between engine torque and rotational speed and the amount of heat generated by the torque converter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Automatic stepped transmission, 3 ... Motor, 4 ... Throttle valve, 5 ... TCM, 6 ... Throttle sensor, 7 ... A / TC / U, 8 ... Vehicle speed sensor, 9 ... Accelerator opening Degree sensor, 10 ... Rotation sensor, 11 ... Oil temperature sensor, 12 ... Warning light

Claims (2)

A control device for a transmission with a torque converter,
An oil temperature detecting means for detecting an oil temperature of the transmission or a temperature correlated with the oil temperature;
Generated torque reducing means for continuously reducing the generated torque of the engine when the temperature detected by the oil temperature detecting means is equal to or higher than a predetermined temperature;
Lockup area expanding means for expanding the lockup area of the lockup clutch provided in the torque converter more than usual when the generated torque of the engine is continuously reduced by the generated torque reducing means;
Instantaneous heat generation amount calculating means for calculating the instantaneous heat generation amount in the torque converter;
Integration means for integrating the instantaneous heat generation calculated by the instantaneous heat generation calculation means for a predetermined time;
Torque down amount setting means for setting a torque down amount in the generated torque reducing means based on the temperature detected by the oil temperature detecting means and the integrated value in the integrating means;
A control apparatus for a transmission, comprising: Control device for a transmission according to claim 1, characterized in that a warning means for warning a state in which continuously reduce the generated torque of the engine by the generated torque reducing means to the driver.

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