JP2012031916A - Vehicle control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control apparatus that prevent an oil temperature from increasing while preventing a vehicle from going down in a status that a stall state of a torque convertor continues during a stop of the vehicle on an uphill to increase the oil temperature of torque convertor.SOLUTION: The apparatus includes: an engine 1; an automatic transmission 3 for transmitting the drive force of the engine 1 to a drive wheel of the vehicle; a braking device for restricting the movement of a wheel of the vehicle; the torque convertor 2 installed between the engine 1 and the automatic transmission 3; an oil temperature sensor 72 for detecting the oil temperature supplied to the torque convertor 2; and a control device 60 for setting the automatic transmission 3 to be in a neutral state in which the driving force of the engine 1 is not transmitted to the drive wheel and for controlling the braking device to lock the wheel when the oil temperature detected by the oil temperature sensor 72 reaches a first predetermined value or higher.

Description

  The present invention relates to a vehicle control apparatus equipped with an automatic transmission with a torque converter, and more particularly to a vehicle control apparatus that controls the suppression of an increase in oil temperature caused by a stall or the like in the torque converter and the behavior of the vehicle.

  In a vehicle equipped with an automatic transmission equipped with a torque converter, a stall of the torque converter, that is, a state where the input-side pump is rotating but the output-side turbine is stopped may occur in the torque converter. In this case, if this state continues even if the rotational speed difference (slip) between the pump on the input side of the torque converter and the turbine on the output side becomes large, the oil between the two receives shearing force and generates heat. Causes deterioration of the heat due to heat and deterioration of durability due to heat of the sealing material inside the torque converter.

In view of this, there has been proposed a technique for preventing oil heating by reducing the rotational speed difference on the input / output side of the torque converter by performing control to reduce the engine output if stalling occurs continuously in the torque converter. .
In Patent Document 1, if the stall state of the torque converter continues for a predetermined time or more, the engine output is corrected to decrease for a set time, and after the decrease correction of the engine output is released thereafter, the stall state is again detected within the predetermined time. If detected, the engine output is corrected to decrease if it continues for a second predetermined time set at a time shorter than the predetermined time. Thereby, even if stall conditions frequently occur, it is possible to prevent an increase in the oil temperature in the torque converter.

JP 2003-269206 A

  By the way, for example, when the stall of the torque converter continues when the vehicle is stopped on an uphill road, the output of the engine is reduced due to the torque transmission loss in the torque converter due to the decrease in oil viscosity accompanying the increase in oil temperature. Even if it is increased, the torque to hold the vehicle on the uphill road against the slope is not transmitted to the drive wheels, and if the driver does not operate the brake pedal, the vehicle will slide down. This may cause the driver to feel uncomfortable.

  Under these circumstances, if the driver tries to eliminate the vehicle slip by depressing the accelerator pedal, the oil temperature rises further due to the increased differential rotation of the torque converter. There is also a risk of promoting. In this case, even if the engine output decrease correction is performed as in Patent Document 1, even if the oil temperature can be further prevented from rising, the vehicle cannot be prevented from sliding down.

  The present invention has been devised in view of such a problem, and it is possible to prevent the vehicle from sliding down under a situation where the stall state of the torque converter continues and the temperature of the oil in the torque converter rises while the vehicle is stopped on an uphill road. An object of the present invention is to provide a vehicle control device capable of suppressing an increase in the temperature of the oil while preventing it.

  In order to achieve such an object, a vehicle control device according to the present invention includes an engine that is a drive source of a vehicle, an automatic transmission that transmits driving force of the engine to drive wheels of the vehicle, and movement of wheels of the vehicle. A braking device that regulates the torque, a torque converter provided between the engine and the automatic transmission, an oil temperature sensor that detects the temperature of oil supplied to the torque converter, and the oil temperature sensor When the temperature of the oil exceeds a first predetermined value, the automatic transmission is controlled to enter a neutral state in which the driving force of the engine is not transmitted to the drive wheels, and the brake is controlled to lock the wheels. And a device.

  The automatic transmission includes a shift-by-wire system that performs range change control based on an electrical signal converted by a driver to operate a shift lever, and when the range is changed to a parking range, And a parking lock mechanism that functions as the braking device. The control device is designated by the driver when the temperature of the oil detected by the oil temperature sensor becomes equal to or higher than the first predetermined value. Regardless of the shift position, the automatic transmission is changed to the parking range, and the automatic transmission is controlled to be in a neutral state in which the driving force of the engine is not transmitted to the driving wheels. It is preferable to lock the drive wheels.

  In this case, the shift lever is provided in a shift device that automatically returns to the home position when the driver's operation is completed, and the control device is configured so that the temperature of the oil detected by the oil temperature sensor is the first temperature. When the temperature becomes lower than a second predetermined value set at a temperature lower than the predetermined value, it is preferable to allow a shift to a range other than the parking range by accepting the driver's operation of the shift lever.

  According to the vehicle control device of the present invention, for example, when the oil temperature of the torque converter rises due to the stall condition being continued in the torque converter, the automatic transmission is controlled so that the driving force of the engine is driven by the drive wheels. Therefore, the load on the output side of the torque converter is released. As a result, the output side rotates together with the input side of the torque converter, the difference between the input and output rotational speeds of the torque converter is reduced, and the temperature rise of the oil is suppressed. At the same time, since the wheels are locked by the braking device, even if the driving force is not transmitted to the driving wheels from the output side of the automatic transmission during the uphill road, the vehicle is prevented from sliding down. Can do.

In addition, when a shift-by-wire system and a park lock mechanism are applied to an automatic transmission, a neutral state in which the driving force of the engine is not transmitted to the drive wheels just by setting the automatic transmission range to the parking range, and Since the wheel can be locked, the instruction system can be simplified.
Further, the shift lever is provided in a shift device that automatically returns to the home position when the driver's operation is completed, and the oil temperature becomes equal to or lower than a second predetermined value that is set to a temperature lower than the first predetermined value. If the configuration is such that the operation of the shift lever by the driver is accepted and the shift to a range other than the parking range is permitted, the parking range can be maintained even if the driver operates the shift lever if the oil temperature does not decrease. Therefore, the oil temperature rise can be suppressed. Furthermore, when the temperature of the oil becomes low, the driver's own shift operation is required as a condition for shifting from the parking range to another range. It is possible to avoid a situation in which the vehicle starts to move by shifting to the range.

It is a system configuration figure of the important section of vehicles explaining an embodiment concerning the present invention. It is the principal part block diagram of the automatic transmission explaining embodiment concerning this invention, (a) is the figure which looked at the principal part of the automatic transmission from the axial direction, (b) is A of FIG. 2 (a). It is an arrow view. It is a flowchart of control of the vehicle explaining an embodiment concerning the present invention.

Embodiments according to the present invention will be described below with reference to the drawings.
<System configuration>
First, referring to FIG. 1, the system configuration of the main part of the vehicle will be described.
As shown in FIG. 1, the vehicle according to this embodiment includes an engine 1 that is a drive source of the vehicle, an automatic transmission 3, and an output shaft 11 of the engine 1 and an input shaft 31 of the automatic transmission 3. And a torque converter 2 having a pump 21 on the input side and a turbine 22 on the output side. The output shaft 32 of the automatic transmission 3 is connected to left and right drive wheels 6 and 6 via a power transmission mechanism such as a propeller shaft 4 and a differential 5, and the driving force of the engine 1 is applied to the torque converter 2 and the automatic transmission 3. It is transmitted to the drive wheels 6 and 6 of the vehicle via the transmission 3.

  In the automatic transmission 3, a gear mechanism 33 having a plurality of gear pairs is provided between the input shaft 31 and the output shaft 32 in the transmission casing 30, and a gear pair corresponding to the selected gear stage is used. Is achieved. That is, the gear mechanism 33 is equipped with friction engagement elements (not shown) of a clutch and a brake (not shown) in order to select and use a required gear pair from a plurality of gear pairs. The desired shift speed is achieved by the connection / disconnection combination of the frictional engagement elements corresponding to the selected shift speed.

  In order to control the connection / disconnection of these friction engagement elements in the gear mechanism 33, a control valve 40 for controlling the supply of hydraulic pressure is provided. In addition to a valve system (not shown) for connecting and disconnecting each friction engagement element, the control valve 40 includes a manual valve 41 that performs hydraulic control for switching the range position of the shift lever, and a manual valve 41. And an inhibitor switch 42 for outputting a range signal representing the position.

In the present embodiment, the manual valve 41 is driven by an actuator 44, and a shift-by-wire (hereinafter also referred to as SBW) system is configured therefrom.
Further, a park mechanism (park lock mechanism) 43 as a braking device for setting the gear mechanism 33 to the parking mode is provided. The park mechanism 43 includes a park gear 43a provided on the output shaft 32 of the automatic transmission 3, a park pole 43b meshing with the park gear 43a, a shaft, as shown in FIGS. It comprises a park rod 43c that moves forward and backward in the direction and engages or disengages the park pole 43b with the park gear 43a.

  In addition, an oil pan 50 that stores oil (ATF: Automatic Transmission Fluid, hereinafter also referred to as ATF) 51 is provided at the lower portion of the transmission casing 30. Here, the control valve 40 is an upper part in the oil pan 50, but is disposed below the liquid level of the ATF 51 so as to be immersed in the ATF 51 stored in the oil pan 50. Between the torque converter 2 and the transmission 3, a mechanical oil pump 7 connected to the pump 21 side (engine rotation input side) of the torque converter 2 is provided. The ATF 51 stored in the oil pan 50 is suctioned after being filtered by the strainer 52 by the oil pump 7 and supplied to the control valve 40, the torque converter 2 and each part in the transmission 3, and the like. After that, it circulates back to the oil pan 50 again (see the white arrow in FIG. 1).

  In order to control the control valve 40, an automatic transmission control unit (ATCU) 60 using a computer is provided. The ATCU 60 is provided with a shift-by-wire control unit (SBW control unit) 61 that is a function of controlling the operation of the actuator 44 in addition to the function of controlling the connection / disconnection of the friction engagement element of the gear mechanism 33.

  The shift device 8 in which the driver shifts the transmission is of a type in which the shift lever 81 automatically returns to the home position when the driver completes the operation of the shift lever 81. That is, when the shift lever 81 is operated in the directions indicated by arrows R, N, and D in FIG. 1, the respective shift ranges (reverse range for R, neutral range for N, drive range for D) are selected, and then the shift lever When the hand is released from 81, the shift lever 81 returns to the home position. When the drive range D is selected and operated in the S direction, the manual shift mode is set. In this state, when the shift lever 81 is operated in the + direction, a shift up command is issued, and when the shift lever 81 is operated in the-direction. A downshift command is issued.

In the case of this embodiment, the parking range for operating the park mechanism 43 is selected by pressing a dedicated parking button 82. The parking button 82 also automatically returns to the home position after the driver's operation. The parking range may be set so that it can be selected by the shift lever 81.
Further, a shift sensor (not shown) that detects the shift range selection state of the shift lever 81 and outputs it as a detection signal (shift sensor signal) is provided, and the shift sensor signal and the operation signal (P button signal) of the parking button 82 are output from the shift sensor. Input to the ATCU 60.

Although not shown, an indicator for displaying the selected shift range is provided on a meter panel or the like in the passenger compartment, and the driver can confirm the selected shift range through the shift lever 81 or the parking button 82 by the indicator display. .
The ATCU 60 receives a shift sensor signal and a P button signal, and also receives detection information of the engine speed Ne and the accelerator pedal opening AP from the vehicle-side computer 70, and further determines the speed of the transmission output shaft 23. Output shaft rotation speed detection information (vehicle speed V information) from the output shaft rotation speed sensor 71 to be detected and ATF oil temperature detection from the temperature sensor 72 to detect the oil temperature of the ATF 51 (temperature of oil supplied to the torque converter 2). Information is entered.

  The ATCU 60 controls the control valve 40 based on each input information. For example, if a P button signal (parking on signal) is input, a control signal is sent from the SBW control unit 61 of the ATCU 60 to the actuator 44, and the actuator 44 puts the park mechanism 43 into an operating state. As a result, the output shaft 32 of the automatic transmission 3 is locked and its rotation is restricted. When a shift sensor signal is input, a control signal is sent from the SBW control unit 61 of the ATCU 60 to the actuator 44, and the actuator 44 drives the manual valve 41 to a state in which the manual valve 41 is regulated to a shift range corresponding to the shift sensor signal. .

  Note that the position of the manual valve 41 at this time can be recognized from the movement of the actuator 44. That is, it is always recognized how many times the actuator 44 itself has rotated relative to the P range reference, and it is also known how many times the actuator 44 is rotated, so that the position of the manual valve 41 can be recognized. The position information of the manual valve 41 recognized in this way is sent to the SBW control unit 61, and the SBW control unit 61 performs control through the actuator 44 while confirming the position of the manual valve 41.

  When the manual valve 41 is set to the forward travel range D, the ATCU 60 performs an illustration based on the output shaft rotation speed information, that is, the vehicle speed V information corresponding to the output shaft rotation speed and the accelerator opening AP information. Using the map that is not used, the speed is appropriately switched to the gear position corresponding to the traveling state. At this time, when the manual shift mode is selected, the ATCU 60 switches the gear position according to the shift up command or the shift down command of the shift lever 81.

The ATCU 60 is provided with an oil high temperature control unit (control device) 62 as a functional element that performs specific control when the ATF temperature becomes excessively high.
The oil high temperature control unit 62 assumes that the stall state of the torque converter 2 has continued for a predetermined time or longer, and the ATF oil temperature (temperature of oil supplied to the torque converter 2) T _ATF detected by the temperature sensor 7. Is _{equal to} or greater than a preset first predetermined value T _ATFS1 , the manual valve 41 of the automatic transmission 3 is controlled through the SBW control unit 61 so that the driving force of the engine 1 is not transmitted to the drive wheels 6. At the same time, the park mechanism 43 of the automatic transmission 3 is forcibly controlled to the park state through the SBW control unit 61 (this is referred to as “forced P range control”), and the wheels are locked. At the same time, the shift range indicator is switched to P (parking).

As the first predetermined value T _ATFS1 , a temperature (for example, about 140 ° C.) slightly higher than the upper limit of the allowable temperature range as the ATF oil temperature is set.
Whether the torque converter 2 is in a stalled state is determined based on the vehicle speed condition, the accelerator opening condition, and the engine speed condition. The precondition for performing the forced P range control is the torque converter. No. 2 stall state has continued for more than a predetermined time (continuation condition).

This precondition will be further described.
The vehicle speed condition is “the vehicle is in a stopped or substantially stopped state”, and specifically, “the vehicle speed V obtained from the detection information of the output shaft rotation speed is less than a preset vehicle speed threshold V _S. It must be there. Since the vehicle speed threshold V _S is used to determine whether the vehicle is stopped or substantially stopped, a value close to 0 (for example, about several km / h) is set as the vehicle speed threshold V _S.

The accelerator opening condition is that the engine output is relatively large, specifically, the "the accelerator opening AP is the accelerator position threshold AP _S above a preset". Engine output accelerator position threshold AP _S is one of the determination conditions of the stall state of the torque converter (here, the engine output demand) because they are used to determine if there is more than a predetermined, the accelerator position threshold AP _S Sets a value (for example, about 2/8 to 3/8) that can clearly determine the accelerator operation.

The engine speed condition is “the engine speed is sufficiently high”, and specifically, “the engine speed Ne is equal to or higher than a preset engine speed threshold Ne _S ”. To do. Since the engine speed threshold value Ne _S is used to determine whether the engine speed is one of the conditions for determining the stall state of the torque converter and whether the engine speed is in a high speed state higher than a certain value, a sufficiently large value (for example, about 4000 rpm). ) Is set.

When the vehicle is stopped, the engine output is large, and the engine speed (that is, the differential speed of the torque converter) is sufficiently high, it can be determined that the torque converter 2 is in a stalled state.
Here, it is assumed that the precondition is satisfied when the stall state of the torque converter 2 continues for a predetermined time. The reason for the duration as described above is to distinguish a stalled state that is a problem from a stalled state that does not become another problem, and to prevent unnecessary “forced P range control” from being performed. The time is preferably set to about 10 to 20 seconds, for example.

Further, when the forced P range control is performed by the oil high temperature control unit 62, a signal indicating that the forced P range control is performed is output to an engine control unit (not shown), and the engine is controlled regardless of the accelerator opening. Output suppression control for keeping the output at a predetermined level (for example, an idle state) is also performed at the same time.
Incidentally, the oil at high temperature control unit 62, when you have such control that the vehicle is parked, the ATF oil temperature T _ATF detected by the temperature sensor 72 is, than the first predetermined value T _ATFS1 When the temperature _becomes equal to or lower than a second predetermined value T _ATFS2 set in advance as a low temperature, a shift to a range other than the parking range is permitted by accepting the driver's operation of the shift lever 81. As this 2nd predetermined value _TATFS1 , the temperature (for example, about 120 _degreeC ) close _| similar to the upper limit of the allowable temperature range as ATF oil temperature is set.

As described above, the ATF oil temperature T _ATF is set lower by giving hysteresis to the second predetermined value T _ATFS2 that is the end threshold _than the first predetermined value T _ATFS1 that is the start threshold of the oil high temperature control. Thus, control hunting is prevented. Further, by adding the driver's operation of the shift lever 81 to the end condition of the high-temperature control, it is possible to prevent the vehicle from moving from the parking range to another range without the intention of the driver. Like to do.

Since the vehicle control apparatus according to the present embodiment is configured as described above, focusing on the control of the high oil temperature control unit 62, the control is performed as shown in the flowchart of FIG. In FIG. 3, the “forced P range flag” indicates that when the oil high temperature control unit 62 determines that the ATF oil temperature T _ATF is _{equal to} or higher than the first predetermined value T _ATFS1 and performs the forced P range control. Is set to 1. On the other hand, when the forced P range control is not performed, the value is 0. When the forced P range control is performed, the oil high temperature control unit 62 determines that the ATF oil temperature T _ATF is less than or equal to the second predetermined value T _ATFS2 . If it is determined that there is, it is reset from 1 to 0. Further, the flow of FIG. 3 is performed at a predetermined cycle.

As shown in FIG. 3, first, it is determined whether or not the forced P range flag is 0 (step S10). If the forced P range flag is 0, it is determined whether or not the vehicle speed V is equal to or less than the vehicle speed threshold value V _S (step S20). Here, if the vehicle speed V is less speed threshold V _S, the accelerator pedal opening AP is whether or not accelerator pedal opening threshold value AP _S or not is determined (step S30). Here, the accelerator pedal opening AP is equal to accelerator position threshold AP _S above the engine speed Ne is whether or not the engine rotational speed threshold value Ne _S or not is determined (step S40).

Here, if the engine speed Ne is equal to or greater than the engine speed threshold value Ne _S, it is determined that the torque converter 2 is in a stalled state, and timer counting is started (step S50).
On the other hand, if the force P range flag is 0, the vehicle speed V is greater than the vehicle speed threshold V _S, the accelerator pedal opening AP is smaller than the accelerator position threshold AP _S, the engine speed Ne is the engine rotational speed less than the threshold value Ne _S, of If it is either, it determines with the torque converter 2 not being in a stall state, and complete | finishes this process.

Start the timer count when the (Step S50) was the timer count value t whether or not the timer threshold t _S or not is determined (step S60). If the timer count value t is not the timer threshold t _S concludes the current process.
Start the timer count, the vehicle speed V is less speed threshold V _S, and the accelerator opening AP is the accelerator position threshold AP _S or more and the engine speed Ne is the engine speed threshold value Ne _S or more, the state continuation Then, eventually, the timer count value t becomes more than the timer threshold _{t S,} this case, ATF oil temperature _{T ATF} detected by the temperature sensor 7 determines whether or not the first predetermined value _{T ATFS1} above ( Step S70).

Here, if the ATF oil temperature T _ATF is not equal to or higher than the first predetermined value T _ATFS1 , the current process is finished.
On the other hand, if the ATF oil temperature T _ATF is _{equal to} or higher than the first predetermined value T _ATFS1, it is assumed that the temperature of the ATF is excessively raised, the forced P range flag is set to 1, and the automatic transmission is made through the SBW control unit 61 3 is controlled to a neutral state in which the driving force of the engine 1 is not transmitted to the drive wheels 6, and the park mechanism 43 of the automatic transmission 3 is forcibly controlled to the park state through the SBW control unit 61 (forced) P range control) (step S80). At the same time, the shift range indicator is switched to P (parking).

As described above, when the torque converter 2 is in a stalled state for a predetermined time t _S or longer and the ATF temperature T _ATF is excessively high, the torque converter 2 can transmit the torque converter 2 due to a decrease in the ATF viscosity. If the torque capacity is significantly reduced and the vehicle is on an uphill road, torque sufficient to stop the vehicle cannot be transmitted to the drive wheels, which may cause the vehicle to slide down. Further, if the viscosity of ATF is significantly reduced, ATF may leak from the circulation system.

  On the other hand, in this apparatus, in such a case, forced P range control is performed to control the automatic transmission 3 so that the driving force of the engine 1 is not transmitted to the drive wheels. The load on the output side is released, and the output side rotates together with the input side of the torque converter 2. At the same time, output suppression control that keeps the engine output at a predetermined level is also performed. Thereby, the input / output rotational speed difference of the torque converter 2 is reduced, the temperature rise of the ATF is suppressed, and the temperature of the ATF is lowered.

Therefore, the possibility that ATF leaks from the circulation system is also avoided. At the same time, since the wheels (drive wheels 6) are locked by the park mechanism as a braking device, even if driving force is not transmitted from the output side of the automatic transmission to the drive wheels in the middle of the uphill road, The vehicle can be prevented from sliding down.
Thus, it is determined if the forced P-range flag is set to 1, the next cycle is determined in step S10, the process proceeds to step S90, ATF oil temperature _{T ATF} is whether a second predetermined value _{T ATFS2} less . If the ATF oil temperature T _ATF is not equal to or lower than the second predetermined value T _ATFS2 , the current process is terminated.

When the temperature of the ATF decreases due to the forced P range control, the ATF oil temperature T _ATF eventually becomes equal to or lower than the second predetermined value T _ATFS2 . In this case, the driver operates the shift lever 81. It is determined whether or not it has been performed, that is, whether or not a switching operation from the P range to another range has been performed (step S100).
If the driver does not operate the shift lever 81, the current process is terminated and the forced P range control is continued. If the driver operates the shift lever 81, the forced P range flag is reset to 0 (step S110), the selection request by the driver's operation of the shift lever 81 is permitted, the shift is made to the range corresponding to the selection request, and the normal selection control is returned (step S120).

  As described above, according to the present apparatus, the park mechanism is controlled by the shift-by-wire system of the automatic transmission 3, so that the range of the automatic transmission 3 can be changed to the parking range by forced P range control. Since the neutral state in which the driving force of 1 is not transmitted to the driving wheel 6 and the locking of the wheel 6 can be realized, the indicating system can be simplified.

  Further, since the shift lever 81 automatically returns to the home position when the driver's operation is completed, the range display of the indicator is displayed even if the automatic transmission 3 range is set to the parking range by forced P range control. By simply switching to P (parking), there is no inconsistency between the shift lever 81 and the indicator range display, and control without a sense of incongruity is realized.

If the ATF temperature does not decrease, the driver does not shift from the parking range to another range even if the driver operates the shift lever 81. Therefore, the vehicle slips on the uphill road while reliably suppressing the temperature increase of the ATF temperature. A fall can be prevented.
In addition, when the ATF temperature is lowered, the shift operation of the driver himself / herself is a condition for shifting from the parking range to another range. Therefore, the parking range is shifted to another range, for example, the drive range, without the driver's intention. It is possible to avoid the vehicle starting to move, for example, by shifting to.

Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications may be made to the embodiment without departing from the gist of the present invention. Can do.
For example, in the above embodiment, the park mechanism (park lock mechanism) 43 is used as a control device, and by operating the park mechanism 43, the gear mechanism of the automatic transmission 3 is brought into the neutral state and the wheels are locked. However, as a control device, a braking mechanism (either a parking brake or a foot brake) that locks the wheels themselves (which may be driven wheels as well as driving wheels) is used as a control device, and the range of the automatic transmission 3 is neutral. A range is also possible.

  In the above embodiment, a shift lever that automatically returns to the home position when the driver completes the operation is applied. However, a shift lever that does not return to the home position is also applicable. It is. In this case, the range of the automatic transmission 3 is switched to the parking range or neutral range by forced P range control, and the position of the shift lever 81 is changed to the switched parking range or neutral range to change the indicator range display to P. It is preferable to prevent inconsistency between the shift lever 81 and the indicator range display by switching to (parking) or N (neutral).

DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 3 Automatic transmission 4 Propeller shaft 5 Differential 6 Drive wheel 7 Oil pump 8 Shift device 11 Output shaft of engine 1 21 Pump of torque converter 2 22 Turbine of torque converter 2 30 Transmission casing 31 Automatic transmission 3 Input shaft 32 Output shaft of automatic transmission 3 33 Gear mechanism 40 Control valve 41 Manual valve 42 Inhibitor switch 43 Park mechanism (park lock mechanism) as a braking device
44 Actuator 51 Oil (ATF)
50 Oil pan 52 Strainer 60 Automatic transmission control unit (ATCU)
61 Shift-by-wire control unit (SBW control unit)
62 Control section at high temperature of oil (control device)
70 Vehicle side computer 71 Output shaft rotational speed sensor 72 Temperature sensor (oil temperature sensor)
81 Shift lever 82 Parking button

Claims (3)

An engine that is a driving source of the vehicle;
An automatic transmission for transmitting the driving force of the engine to driving wheels of a vehicle;
A braking device for restricting the movement of the wheels of the vehicle;
A torque converter provided between the engine and the automatic transmission;
An oil temperature sensor for detecting the temperature of oil supplied to the torque converter;
When the temperature of the oil detected by the oil temperature sensor becomes equal to or higher than a first predetermined value, the automatic transmission is controlled to be in a neutral state where the driving force of the engine is not transmitted to the drive wheels, and the braking device is A control device for controlling and locking the wheel;
A vehicle control device comprising: The automatic transmission includes a shift-by-wire system that performs range change control based on an electrical signal converted from a shift lever operation by a driver;
When the range is changed to a parking range, it has a park lock mechanism that locks the drive wheels and functions as the braking device,
When the oil temperature detected by the oil temperature sensor becomes equal to or higher than the first predetermined value, the control device changes the automatic transmission to the parking range regardless of the shift position designated by the driver. The control device according to claim 1, wherein the automatic transmission is controlled to be in a neutral state where the driving force of the engine is not transmitted to the driving wheels, and the driving wheels are locked by the park lock mechanism. Vehicle control device. The shift lever is provided in a shift device that automatically returns to the home position when the driver's operation ends.
When the temperature of the oil detected by the oil temperature sensor becomes equal to or lower than a second predetermined value set to a temperature lower than the first predetermined value, the control device operates the shift lever of the driver. The vehicle control device according to claim 2, wherein a shift to a range other than the parking range is permitted by accepting.

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