JP2012107722A - Overheat determining device of transmission and overheat preventive device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of determining and preventing overheat of the transmission, even if the transmission is a manual transmission or the like unable to grasp a shift state.SOLUTION: When a vehicle speed VSP and the engine intake air temperature TEMP_ENG_AIR rise as illustrated by accelerator stepping of t1, a transmission overheat determining time TM_OVRH corresponding to these combinations becomes 0 by reducing as illustrated. Thereby, the transmission overheat determining time TM_OVRH becomes smaller than a vehicle speed limiting timer value TM_VSP_Lim up to an overheat preventive vehicle speed limit, and it is determined that the oil temperature is rising. During this time, the TM_OVRH is subtracted, and in t2 when becoming TM_OVRH=0 (when an oil temperature rise continues for a TM_OVRH time), a FLAG is set to 1 by determining the overheat of the transmission. The overheat of the transmission 2 is prevented by limiting so that the vehicle speed VSP does not exceed VSP_Lim_OVRH, with a limiting vehicle speed VSP_Lim as the overheat preventive limiting vehicle speed VSP_Lim_OVRH by FLAG=1.

Description

  The present invention is not capable of grasping a shift state like a transmission that shifts and outputs the rotation of an engine, particularly a manual transmission, and cannot determine whether the transmission is overheated by monitoring this shift state. Even in this case, the present invention relates to an overheat determination device capable of determining an overheat state of a transmission, and an overheat prevention device for a transmission using the same.

Conventionally, for example, a technique described in Patent Document 1 is known as an overheat determination (transmission oil temperature determination) technique for a transmission.
The transmission oil temperature judgment technology that becomes the proposed technology is based on the shift state of the automatic transmission (heat generation due to slip of a fluid coupling such as a torque converter, heat generation due to agitation of transmission hydraulic fluid, frictional heat of a transmission friction element, etc.) By estimating the oil temperature rise and oil temperature drop associated with machine hydraulic oil, and summing the total oil temperature change estimated from the gear shift state to the initial oil temperature at the start of transmission operation, The transmission oil temperature (transmission overheat) is determined.

Japanese Patent Laid-Open No. 08-233080

However, in the conventional transmission oil temperature judgment technology, a shift is automatically performed like an automatic transmission, and a shift state (heat generation due to slip of a fluid coupling such as a torque converter or heat generation due to gear agitation of transmission hydraulic oil) And the oil temperature of the transmission can be determined only when it is possible to grasp the frictional heat of the transmission friction element)
When the shift state cannot be grasped like a manual transmission in which the driver manually shifts, heat generated by slipping of a fluid coupling such as a torque converter, heat generated by gear agitation of the transmission hydraulic fluid, shift friction, Since the frictional heat of the elements cannot be estimated one by one, it is impossible to determine the oil temperature of the transmission.

According to the present invention, the time required for the transmission to rise to the overheat determination temperature is approximately the transmission rotation that can be obtained from the engine intake air temperature that can be directly detected by a temperature sensor or the like, and the vehicle speed without relying on grasping the shift state. Based on the fact that it is possible to determine that the transmission has overheated if the transmission temperature rises for this amount of time.
This idea is embodied, and the shift state which can be determined even when the transmission state cannot be grasped as in the case of a manual transmission and the overheating determination of the transmission cannot be performed by the conventional method described above. It is an object of the present invention to provide a machine overheat determination device and a transmission overheat prevention device using the same.

For this purpose, the transmission overheat determination device according to the present invention is configured as follows.
First, a premised transmission will be described. This is a transmission that shifts and outputs engine rotation.

In the present invention, an overheat determination device for such a transmission is used.
Engine intake air temperature detecting means for detecting the intake air temperature of the engine;
Transmission rotational speed information acquisition means for acquiring information related to the internal rotational speed of the transmission;
Based on signals from these means, transmission temperature rise detection means for detecting the temperature rise of the transmission from changes in engine intake air temperature and transmission rotational speed information;
A transmission temperature rise time measuring means for measuring a time during which a temperature rise of the transmission is detected by the means;
When the transmission temperature rise time measured by the means reaches the transmission overheat determination time until the transmission overheat state is obtained in advance for each combination of the engine intake temperature and the transmission rotational speed information, And a transmission overheat determination means for determining that the transmission is overheated.

  In the transmission overheat prevention device according to the present invention, while the transmission overheat determination means determines that the transmission is in an overheated state, an allowable upper limit value related to the internal rotation speed of the transmission is set to an allowable upper limit. The present invention is characterized by a structure provided with a transmission rotation speed limiting means for reducing the value to a value to be prevented.

In the overheat determination device for a transmission according to the present invention described above, while detecting that the transmission is increasing in temperature from changes in engine intake air temperature and transmission rotation speed information, this transmission temperature increase time is: In order to determine that the transmission has been overheated when the predetermined transmission overheat determination time is reached for each combination of engine intake air temperature and transmission rotational speed information,
From the engine intake temperature that can be directly detected by a temperature sensor, etc., and the transmission rotational speed information that can be obtained based on the vehicle speed, etc., that is, from the engine intake temperature and transmission rotational speed information that are obtained without grasping the shift state, the transmission overheats. Can be determined.

  Therefore, according to the present invention, it is possible to determine whether the transmission is overheated even when the shift state cannot be grasped as in a manual transmission in which the driver manually shifts.

Further, the transmission overheat prevention device according to the present invention sets the allowable upper limit value related to the internal rotation speed of the transmission to a value that prevents the transmission from being overheated while it is determined that the transmission is in an overheated state as described above. To lower
Such an internal rotation speed of the transmission does not exceed the above-described allowable upper limit value, but is limited to a value lower than this, and the transmission can be prevented from being overheated.

1 is a schematic system diagram showing a power train of a vehicle including an overheat determination device for a transmission and an overheat prevention device according to an embodiment of the present invention, together with its control system. FIG. 2 is a functional block diagram illustrating a transmission vehicle overheat determination and overheat prevention limited vehicle speed calculation unit in the power train control system shown in FIG. 3 is a time chart showing an oil temperature rise transition of the manual transmission shown in FIG. 2 together with an allowable upper limit temperature when traveling at a certain vehicle speed. FIG. 3 is a change characteristic diagram of a limit vehicle speed necessary for preventing overheating of the manual transmission shown in FIG. 3 is an operation time chart of the transmission overheat determination device and the overheat prevention device of the embodiment shown in FIGS.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
<Configuration of Example>
FIG. 1 is a schematic system diagram showing a power train of a vehicle including an overheat determination device for a transmission and an overheat prevention device according to an embodiment of the present invention, together with its control system.
In the figure, 1 is an engine that is a power source of the vehicle, 2 is a manual transmission, and a vehicle having a power train composed of the engine 1 and the manual transmission 2 receives power from the engine 1 as a manual transmission. The vehicle can travel by being transmitted to a drive wheel (not shown) under the speed change of 2.

The engine 1 includes an electronically controlled throttle valve 3, and the throttle valve 3 is electronically controlled by a motor 4 so that the output is adjusted.
The motor 4 responds to the throttle opening command tTVO obtained by the throttle opening command calculation unit 11 and electronically controls the throttle valve 4 so that the opening coincides with the throttle opening command tTVO.

The throttle opening command calculation unit 11 basically obtains the throttle opening command tTVO as follows.
In other words, the driver requested driving force calculation unit 12 determines the current engine based on the planned driving force map from the engine speed Ne detected by the engine rotation sensor 13 and the accelerator opening APO detected by the accelerator opening sensor 14. The driver requested driving force tTd requested by the driver by the accelerator pedal operation (accelerator opening APO) under the rotation speed Ne is obtained.
The throttle opening degree command calculation unit 11 basically determines the throttle opening degree necessary for realizing the driver required driving force tTd as a throttle opening degree instruction tTVO.

<Transmission overheating judgment and overheating prevention>
In order to perform overheating determination and prevention of overheating of the manual transmission 2 in the power train shown in FIG. 1, a limited vehicle speed calculation unit 15 for transmission overheating determination and overheating prevention is provided in this embodiment.
A signal from the vehicle speed sensor 16 that detects the vehicle speed VSP and an engine intake air temperature sensor 17 that detects the engine intake air temperature TEMP_ENG_AIR are sent to the transmission overheat determination and overheat prevention limiting vehicle speed calculation unit 15. The signal from is input.
The vehicle speed VSP represents information related to the internal rotational speed of the transmission 2, and therefore the vehicle speed sensor 16 corresponds to the transmission rotational speed information acquisition means in the present invention.

  The limit vehicle speed calculation unit 15 for transmission overheat determination and overheat prevention is as shown in the block diagram of FIG. 2 and is based on the vehicle speed VSP detected by the sensors 16 and 17 and the engine intake air temperature TEMP_ENG_AIR as follows. The overheat determination of the manual transmission 2 and the calculation of the overheat prevention limit vehicle speed VSP_Lim are performed.

The transmission overheat determination and overheat prevention limiting vehicle speed calculation unit 15 is as shown in FIG. 2 as a whole, and a transmission overheat determination time setting unit 21 is provided. The transmission overheat determination time setting unit 21 includes the following: Have a built-in map (database).
In other words, for each combination of the engine intake air temperature TEMP_ENG_AIR and the vehicle speed VSP, from a certain arbitrary reference timing, the hydraulic oil temperature of the manual transmission 2 is an allowable upper limit temperature that can be tolerated for various parts including the seal of the transmission. The time to be obtained is obtained in advance by experimentation, etc., and these times are mapped (databased) as the transmission overheat determination time TM_OVRH, and this map (database) is built in the setting unit 21.

Here, the transmission overheat determination time TM_OVRH will be described with reference to FIG.
The hydraulic oil for transmission 2 has a higher temperature because the higher the vehicle speed VSP and the higher the internal rotation speed of the transmission, the more heat is generated by stirring, and the higher the engine intake temperature TEMP_ENG_AIR, the faster the engine temperature rises. .
The temporal transition of the transmission hydraulic fluid temperature under a certain vehicle speed VSP is typically shown when the engine intake air temperature TEMP_ENG_AIR is, for example, 25 ° C, 30 ° C, 35 ° C, 40 ° C. As shown in Fig. 3, the transmission hydraulic oil temperature varies with the engine intake air temperature TEMP_ENG_AIR, and rises with time in the same tendency.
The speed at which the transmission hydraulic fluid temperature rises is higher than that shown in FIG. 3 at higher vehicle speeds, and is slower than that shown in FIG. 3 at lower vehicle speeds.

  The time required for the transmission hydraulic oil temperature to reach the allowable upper limit temperature is TM_OVRH (as the engine intake air temperature TEMP_ENG_AIR decreases to 40 ° C, 35 ° C, 30 ° C, 25 ° C according to the engine intake air temperature TEMP_ENG_AIR. 1), TM_OVRH (2), TM_OVRH (3), TM_OVRH (4), and these times TM_OVRH (1), TM_OVRH (2), TM_OVRH (3), TM_OVRH (4) are the vehicle speed VSP. The lower the value, the longer.

  These times TM_OVRH (1), TM_OVRH (2), TM_OVRH (3), TM_OVRH (4) ... are obtained in advance through experiments, etc., and the transmission overheat determination time for each combination of engine intake air temperature TEMP_ENG_AIR and vehicle speed VSP This is mapped as TM_OVRH, and a map of the transmission overheat determination time TM_OVRH is stored in the transmission overheat determination time setting unit 21.

  The transmission overheat determination time setting unit 21 reads and sets the transmission overheat determination time TM_OVRH one by one from the combination of the engine intake temperature TEMP_ENG_AIR and the vehicle speed VSP based on the above map.

As shown in FIG. 2, the transmission vehicle overheat determination and overheat prevention limiting vehicle speed calculation unit 15 further includes a size comparison unit 22,
According to the comparison result here, a vehicle speed limit timer value selection determining unit 23 that selects and determines a vehicle speed limit timer value TM_VSP_Lim that is a time until the vehicle speed limit for preventing transmission overheating is selected.
A storage unit 24 for storing the previous value TM_VSP_Lim (1 / Z) of the vehicle speed limit timer value TM_VSP_Lim;
Select high part 25 for selecting the maximum value {TM_VSP_Lim (1 / Z), TM_OVRH} of the previous value TM_VSP_Lim (1 / Z) of the vehicle speed limit timer value TM_VSP_Lim and the transmission overheat determination time TM_OVRH, and
A subtraction counter 26 for subtracting this Max {TM_VSP_Lim (1 / Z), TM_OVRH} by a countdown set time for each operation cycle;
An addition counter 27 is provided for adding the previous value TM_VSP_Lim (1 / Z) of the vehicle speed limit timer value TM_VSP_Lim by the count up shift set time every calculation cycle.

  The size comparison unit 22 compares the previous value TM_VSP_Lim (1 / Z) of the vehicle speed limit timer value TM_VSP_Lim with the transmission overheat determination time TM_OVRH, and TM_OVRH ≦ TM_VSP_Lim (1 / Z) or vice versa TM_OVRH Check if> TM_VSP_Lim (1 / Z).

  The vehicle speed limit timer value selection deciding unit 23 calculates the maximum {TM_VSP_Lim (1 / Z), TM_OVRH} obtained by the subtraction counter 26 when the comparison result in the magnitude comparison unit 22 is TM_OVRH ≦ TM_VSP_Lim (1 / Z). A subtraction count value that decreases by the countdown setting time is selected and defined as a vehicle speed limit timer value TM_VSP_Lim.

  The vehicle speed limit timer value selection / determination unit 23 counts up from TM_VSP_Lim (1 / Z) obtained by the addition counter 27 when the comparison result in the magnitude comparison unit 22 is TM_OVRH> TM_VSP_Lim (1 / Z). An addition count value that becomes longer for each set time is selected and determined as a vehicle speed limit timer value TM_VSP_Lim.

As is clear from the above, the comparison result in the magnitude comparison unit 22 is that TM_OVRH ≦ TM_VSP_Lim (1 / Z) means that the oil temperature of the transmission 2 is rising and the allowable upper limit temperature in FIG. (The transmission 2 becomes overheated).
Therefore, the size comparison unit 22 corresponds to the transmission temperature rise detection means in the present invention.

Therefore, during this time, the vehicle speed limit timer value selection determination unit 23 calculates the subtraction count value, which is obtained by the subtraction counter 26 as described above, and decreases from the Max {TM_VSP_Lim (1 / Z), TM_OVRH} by the countdown set time, as described above. By defining
When this vehicle speed limit timer value TM_VSP_Lim becomes 0, it indicates that the oil temperature has continued to rise for the transmission overheat determination time TM_OVRH set at the start of the oil temperature rise. It is possible to determine that an overheated state has been reached.
Therefore, the vehicle speed limit timer value selection determination unit 23 and the subtraction counter 26 correspond to the transmission temperature rise time measuring means in the present invention.

On the contrary, the comparison result in the magnitude comparison unit 22 is TM_OVRH> TM_VSP_Lim (1 / Z). This means that the oil temperature of the transmission 2 is decreasing and reaches the allowable upper limit temperature in FIG. It does not become overheated).
Therefore, the size comparison unit 22 corresponds to the transmission temperature drop detection means in the present invention.
Therefore, since it is not necessary to determine whether the transmission 2 is overheated during this period, the vehicle speed limit timer value selection determination unit 23 increases the count-up set time from TM_VSP_Lim (1 / Z) obtained by the addition counter 27 as described above. By selecting the addition count value and determining it as the vehicle speed limit timer value TM_VSP_Lim, the measurement of the oil temperature rise duration (transmission overheat determination) is not performed.
Therefore, the addition counter 27 corresponds to the transmission overheat determination prohibiting means in the present invention.

  As shown in FIG. 2, the transmission vehicle overheat determination and overheat prevention limit vehicle speed calculation unit 15 includes an overheat determination unit 28, a transmission vehicle overheat prevention limit vehicle speed setting unit 29, a select low unit 31, and a limited vehicle speed selection. A determination unit 32;

  The overheat determination unit 28 determines whether or not the transmission 2 has overheated because the oil temperature increase continues for the transmission overheat determination time TM_OVRH set at the start of the oil temperature increase depending on whether the vehicle speed limit timer value TM_VSP_Lim is 0 or not. Determine whether.

When the overheat determination unit 28 determines that the transmission 2 has reached an overheat state, it sets the transmission overheat determination flag FLAG to 1,
Decreasing transmission oil temperature {TM_OVRH> TM_VSP_Lim (1 / Z)} in the size comparison unit 22 and the vehicle speed limit timer value TM_VSP_Lim is no longer 0, that is, the transmission 2 is no longer overheated. When the transmission overheat determination flag FLAG is reset to 0.
Therefore, the overheat determination unit 28 corresponds to the transmission overheat determination means in the present invention.

The limited vehicle speed setting unit 29 for preventing transmission overheating searches the limited vehicle speed VSP_Lim_OVRH for preventing transmission overheating based on the engine intake air temperature TEMP_ENG_AIR from the map scheduled to be exemplified in FIG.
This limited vehicle speed VSP_Lim_OVRH for preventing overheating of the transmission is the upper limit vehicle speed that can prevent the overheating state of the transmission 2. The higher the engine intake temperature TEMP_ENG_AIR, the more likely the transmission 2 becomes overheated. Set the vehicle speed limit VSP_Lim_OVRH for use low.

The select low unit 31 selects the smaller Min (VSP_Lim_OVRH, VSP_MAX) among the limited vehicle speed VSP_Lim_OVRH for transmission overheating prevention and the vehicle limited vehicle speed (speed limiter set vehicle speed) VSP_MAX.
By the way, the limited vehicle speed VSP_Lim_OVRH for preventing transmission overheating does not exceed the original vehicle speed limit VSP_MAX, and as a result, the select low unit 31 selects the limited vehicle speed VSP_Lim_OVRH for preventing transmission overheating as Min (VSP_Lim_OVRH, VSP_MAX). .

The limited vehicle speed selection determining unit 32 responds to the transmission overheat determination flag FLAG from the overheat determination unit 28, and if the flag FLAG = 1 (TM_VSP_Lim = 0), that is, while determining that the transmission 2 is in an overheated state. Then, Min (VSP_Lim_OVRH, VSP_MAX) = VSP_Lim_OVRH from the select row unit 31 is selected, and this is determined as the limit vehicle speed VSP_Lim.
Therefore, the limited vehicle speed selection determining unit 32 corresponds to the transmission rotational speed limiting means in the present invention.

  The limited vehicle speed selection determination unit 32 determines that the transmission 2 is not overheated if the transmission overheat determination flag FLAG from the overheat determination unit 28 is the flag FLAG = 0 (TM_VSP_Lim ≠ 0). In the meantime, the vehicle's original limited vehicle speed VSP_MAX is selected and this is determined as the limited vehicle speed VSP_Lim so that the vehicle speed is not substantially limited.

The transmission overheat determination and overheat prevention limiting vehicle speed calculation unit 15 explicitly shown in FIG. 2 instructs the throttle opening command calculation unit 11 as shown in FIG. 1 to limit the vehicle speed VSP_Lim obtained as described above.
The throttle opening command calculation unit 11 basically calculates the driver requested driving force tTd requested by the driver by the accelerator pedal operation (accelerator opening APO) under the current engine speed Ne as described above. The throttle opening required for the realization is the throttle opening command tTVO.

  However, when the limited vehicle speed VSP_Lim_OVRH for transmission overheating prevention is set to the limited vehicle speed VSP_Lim, the throttle opening degree command calculation unit 11 compares the limited vehicle speed VSP_Lim_OVRH for transmission overheating prevention with the detected vehicle speed VSP to determine the vehicle speed. The above throttle opening command tTVO is corrected and supplied to the motor 4 of the electronically controlled throttle valve 3 so that the VSP does not exceed the vehicle speed VSP_Lim_OVRH for the transmission overheating prevention. The vehicle speed is limited to the vehicle speed VSP_Lim_OVRH, and the rotation speed of the transmission 2 is restricted by the vehicle speed restriction to prevent the transmission 2 from being overheated.

  Note that the throttle opening command calculation unit 11 does not require the above vehicle speed limit when VSP_Lim_OVRH> VSP when the vehicle original limit vehicle speed VSP_MAX is set to the limit vehicle speed VSP_Lim. The throttle opening command tTVO necessary for realizing the above is supplied to the motor 4 of the electronically controlled throttle valve 3 without modification.

<Operation of Example>
As shown in FIG. 5, when the accelerator pedal is depressed (increase in accelerator opening APO), the vehicle speed VSP is increased as shown in the figure, and the engine intake air temperature TEMP_ENG_AIR increases as shown in FIG. Will be described below in the case where the value rises as shown in the figure.

Due to the increase in the vehicle speed VSP and the increase in the engine intake temperature TEMP_ENG_AIR shown in the figure, the transmission overheat determination time TM_OVRH calculated by the setting unit 21 in FIG. Decreases and eventually becomes 0.
As a result, the transmission overheat determination time TM_OVRH deviates from the vehicle speed limit timer value TM_VSP_Lim as shown in the lower part of FIG. 5, and the transmission overheat determination time TM_OVRH is less than or equal to the previous value TM_VSP_Lim (1 / Z) become.

  The size comparison unit 22 in FIG. 2 performs the determination of TM_OVRH ≦ TM_VSP_Lim (1 / Z) .When the oil temperature rises after the instant t1 in FIG. 5, the vehicle speed limit timer value selection determination unit 23 in FIG. In order to determine the vehicle speed limit timer value TM_VSP_Lim by selecting the subtraction count value that becomes shorter for each countdown setting time from the obtained Max {TM_VSP_Lim (1 / Z), TM_OVRH} = TM_VSP_Lim (1 / Z), the vehicle speed limit timer value TM_VSP_Lim is During the oil temperature rise after the instant t1 in FIG. 5, the oil temperature gradually decreases with the time-series change shown in accordance with the countdown set time.

Then, at the instant t2 in FIG. 5 when the vehicle speed limit timer value TM_VSP_Lim becomes 0, the overheat determination unit 28 in FIG. 2 performs the oil temperature of the transmission 2 for the transmission overheat determination time TM_OVRH set at the oil temperature rise start time t1. It is determined that the transmission has continued to rise and the transmission 2 has reached an overheat state, and the transmission overheat determination flag FLAG is set to 1 as shown in FIG.
In response to the FLAG = 1 (overheat determination) at the instant t2 in FIG. 5, the limited vehicle speed selection determination unit 32 in FIG. 2 selects Min (VSP_Lim_OVRH, VSP_MAX) = VSP_Lim_OVRH from the select low unit 31, and this transmission The limited vehicle speed VSP_Lim_OVRH for preventing overheating is defined as the limited vehicle speed VSP_Lim.

Thus, from the instant t2 in FIG. 5, the vehicle speed VSP is limited so as not to exceed the limit vehicle speed VSP_Lim_OVRH for preventing transmission overheating, and the vehicle speed VSP is indicated by an arrow α with respect to the vehicle speed indicated by the two-dot chain line according to the driving state. To lower.
Due to such a decrease in vehicle speed, the internal rotation speed of the transmission 2 is reduced, and overheating of the transmission 2 can be prevented, and accordingly, the engine intake air temperature TEMP_ENG_AIR is also reduced as shown in FIG. Prevention can be further ensured.

After the instant t3 in FIG. 5, when the driver decreases the accelerator opening APO in order to decrease the vehicle speed VSP as shown in the figure, the transmission overheat determination time TM_OVRH calculated by the setting unit 21 in FIG. 2 is reduced to the vehicle speed VSP. Accordingly, the length becomes longer as shown in FIG.
As a result, the transmission overheat determination time TM_OVRH deviates from the vehicle speed limit timer value TM_VSP_Lim as shown in the upper part of FIG. 5, and the transmission overheat determination time TM_OVRH is derived from the previous value TM_VSP_Lim (1 / Z) Also grows.

  The size comparison unit 22 in FIG. 2 performs the determination of TM_OVRH> TM_VSP_Lim (1 / Z). During the oil temperature drop after the instant t4 in FIG. 5, the vehicle speed limit timer value selection determination unit 23 in FIG. The vehicle speed limit timer value TM_VSP_Lim is the oil temperature drop after the instant t4 in Fig. 5 because the vehicle speed limit timer value TM_VSP_Lim is selected from the TM_VSP_Lim (1 / Z) obtained in step 4 In the middle, it gradually increases with the time-series change shown in the figure according to the count-up setting time.

Therefore, the vehicle speed limit timer value TM_VSP_Lim does not become 0 after the instant t4 in FIG. 5, and at this instant t4, the overheat determination unit 28 in FIG. 2 determines that the transmission 2 does not reach an overheat state, Reset machine overheat detection flag FLAG to 0.
After the instant t4 in FIG. 5, in response to the FLAG = 0 (no overheating determination), the limited vehicle speed selection determination unit 32 in FIG. 2 selects the vehicle's original limited vehicle speed VSP_MAX, and the vehicle's original limited vehicle speed VSP_MAX is selected as the limited vehicle speed. By setting VSP_Lim, the vehicle speed is not substantially limited.

<Effect of Example>
According to the overheat determination of the transmission according to the above-described embodiment, the transmission overheat determination time TM_OVRH is obtained from the engine intake temperature TEMP_ENG_AIR and the vehicle speed VSP (transmission speed information), and the temperature of the transmission 2 rises based on the change. In order to determine that the transmission 2 is overheated when the transmission temperature rise time reaches the transmission overheat determination time TM_OVRH described above while detecting that the
The engine intake temperature TEMP_ENG_AIR and the vehicle speed VSP (transmission speed) obtained from the engine intake temperature TEMP_ENG_AIR that can be directly detected by the engine intake temperature sensor 17 and the transmission rotation speed information that can be obtained based on the vehicle speed VSP. From the speed information), overheating of the transmission 2 can be determined.

  Therefore, according to the present embodiment, it is possible to determine whether the transmission 2 is overheated even when the driver cannot grasp the shift state like the manual transmission 2 that performs the shift.

Further, according to the overheat prevention device of the transmission according to the present embodiment, the allowable upper limit value of the vehicle speed related to the internal rotation speed of the transmission is determined in FIG. 5 while it is determined that the transmission 2 is in the overheated state as described above. As shown by the arrow α, in order to reduce to a value VSP_Lim_OVRH where the transmission is prevented from overheating,
The vehicle speed VSP (transmission internal rotation speed) does not exceed the allowable upper limit value VSP_Lim_OVRH, but is limited to a value lower than this, and the transmission 2 can be prevented from being overheated.

Since the allowable upper limit value VSP_Lim_OVRH of the vehicle speed VSP is set lower as the engine intake air temperature TEMP_ENG_AIR is higher as illustrated in FIG.
It is possible to achieve the minimum necessary vehicle speed limit for each engine intake temperature TEMP_ENG_AIR, and it is possible to avoid that driving performance is unnecessarily degraded.

Further, in this embodiment, the transmission overheat determination time TM_OVRH for each combination of the engine intake air temperature TEMP_ENG_AIR and the vehicle speed VSP (transmission speed information) is obtained in advance through experiments, etc., and this is mapped to create a transmission overheat determination time setting unit. The transmission overheat determination time TM_OVRH obtained from the combination of the engine intake temperature TEMP_ENG_AIR and the vehicle speed VSP (transmission speed information) is continuously subtracted by the subtraction counter 26 while the oil temperature rises. In order to determine that the transmission 2 is overheated when the subtracted time becomes 0 (overheat determination unit 28),
Advantageously, the overheat determination of the transmission 2 can be reliably performed by a simple calculation.

Further, when it is determined that the oil temperature is rising, the transmission overheat determination time TM_OVRH is equal to or less than the previous value TM_VSP_Lim (1 / Z) of the continuously subtracted time (vehicle speed limit timer value TM_VSP_Lim). In order to make this determination depending on whether or not
It is advantageous that the determination of the oil temperature rise can be easily and reliably performed by comparing internal data.

Also, when the transmission overheat judgment time TM_OVRH increases due to a decrease in the vehicle speed due to the accelerator pedal returning operation, and TM_OVRH> TM_VSP_Lim = 0, the magnitude comparison unit 22 receives this, and the transmission 2 starts to reduce the oil temperature Until the oil temperature decrease start determination, the overheat determination result of the transmission 2 (the vehicle speed limit timer value TM_VSP_Lim is 0) is maintained,
After this oil temperature decrease start determination, the vehicle speed limit timer value selection deciding unit 23 obtains the addition count value obtained by the addition counter 27 as the vehicle speed limit timer value TM_VSP_Lim, which becomes longer from the TM_VSP_Lim (1 / Z) by the set up count time. To complete the transmission 2 overheat determination,
It is possible to avoid the adverse effect that the overheating determination is continued unnecessarily and the vehicle speed limit for preventing overheating is unnecessarily continued.

1 Engine 2 Manual transmission 3 Electronically controlled throttle valve 4 Motor
11 Throttle opening command calculator
12 Driver required driving force calculator
13 Engine rotation sensor
14 Accelerator position sensor
15 Limiting vehicle speed calculation section for transmission overheat detection and overheating prevention
16 Vehicle speed sensor (transmission speed information acquisition means)
17 Engine intake air temperature sensor (engine intake air temperature detection means)
21 Transmission overheat judgment time setting section
22 Size comparison (transmission temperature rise detection means: transmission temperature drop detection means)
23 Vehicle speed limit timer value selection decision section (transmission temperature rise time measuring means)
24 Memory
25 Select High Club
26 Subtraction counter (transmission temperature rise time measuring means)
27 Addition counter (transmission overheat judgment prohibition means)
28 Overheat judgment unit (transmission overheat judgment means)
29 Limiting vehicle speed setting for preventing transmission overheating
31 Select Low
32 Limit vehicle speed selection decision section (transmission speed limit means)

Claims (7)

In an overheat determination device for a transmission that shifts and outputs engine rotation,
Engine intake air temperature detecting means for detecting the intake air temperature of the engine;
Transmission speed information acquisition means for acquiring information related to the internal speed of the transmission;
Based on signals from these means, transmission temperature rise detection means for detecting the temperature rise of the transmission from changes in engine intake air temperature and transmission rotational speed information;
A transmission temperature rise time measuring means for measuring a time during which a temperature rise of the transmission is detected by the means;
When the transmission temperature rise time measured by the means reaches the transmission overheat determination time until the transmission overheat state is obtained in advance for each combination of the engine intake temperature and the transmission rotational speed information, A transmission overheat determination device comprising: a transmission overheat determination means for determining that the transmission is overheated. In the overheat determination device for a transmission according to claim 1,
The transmission temperature rise time measuring means and the transmission overheat determining means obtain in advance a time until the transmission is overheated for each combination of the engine intake air temperature and the transmission rotational speed information, and calculate the time. It has a database for transmission overheat judgment time,
The transmission overheat determination time is obtained from a combination of the engine intake air temperature and transmission rotational speed information based on the database, and the transmission overheat determination time is continuously subtracted during detection of the transmission temperature rise, and the subtraction is performed. An overheat determination device for a transmission, which determines that the transmission is in an overheated state when the measured time becomes zero. In the overheat determination device for a transmission according to claim 2,
The transmission temperature rise detection means is configured so that the transmission overheat determination time obtained from the combination of the engine intake air temperature and the transmission rotational speed information based on the database is equal to or less than the previous value of the subtracted time. An overheat determination device for a transmission, characterized in that the temperature rises. In the overheat determination device for a transmission according to claim 2 or 3,
A transmission temperature decrease detecting means for detecting that the transmission starts to decrease in temperature from changes in the engine intake air temperature and the transmission rotational speed information;
The transmission temperature rise time measuring means and the transmission overheat determination means continue the state where the subtracted time is 0 until the start of transmission temperature drop is detected by the transmission temperature drop detection means. An overheat determination device for a transmission. In the overheat determination device for a transmission according to claim 4,
The transmission temperature decrease detection means increases a transmission overheat determination time obtained from a combination of the engine intake air temperature and transmission rotation speed information based on the database, and exceeds a time when it becomes 0 by the subtraction. When determining that the transmission has started to drop in temperature,
An overheat determination device for a transmission comprising a transmission overheat determination prohibiting means for continuously adding the time when the subtraction becomes 0 after the determination and prohibiting the overheat determination of the transmission. Comprising the overheat determination device according to any one of claims 1 to 5,
While the transmission overheat determining means determines that the transmission is in an overheated state, the transmission rotation speed reduces the allowable upper limit value related to the internal rotation speed of the transmission to a value that prevents the transmission from overheating. An overheat prevention device for a transmission, comprising a limiting means. In the overheat prevention device for a transmission according to claim 6,
An overheat prevention device for a transmission, wherein an allowable upper limit value related to an internal rotation speed of the transmission is lower as the engine intake air temperature is higher.

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