JP6954022B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

Vehicles such as automobiles are provided with an automatic transmission that shifts the rotation transmitted from the engine and outputs it to the wheels, and this automatic transmission is used to switch the power transmission path to change the shift stage. Has a clutch.

As a conventional technique of this kind, the one described in Patent Document 1 is known. In Patent Document 1, when the operating means is switched to the neutral position, the wet clutch is disconnected to shut off the power to the output shaft, and the power shutoff means driven by the driving means also cuts off the power to the output shaft. The power is cut off.

Further, in Patent Document 1, the drum portion integrally formed with the clutch housing and the third idler gear are connected by the hydraulic oil supplied by opening the braking solenoid valve, and the third idler gear is controlled. Power is working. With such a configuration, the one described in Patent Document 1 can prevent the automatic transmission (automatic transmission) from being dragged at the time of neutral at a low temperature.

Japanese Unexamined Patent Publication No. 7-139620

However, the one described in Patent Document 1 has a clutch separately provided in the output portion, which may cause an increase in man-hours, an increase in cost, an increase in weight, and the like. Further, in the case described in Patent Document 1, when the oil temperature of the transmission is low, the viscosity of the oil is high, and the braking of the idler gear may be delayed. As a result, if the oil temperature of the transmission is low, the vehicle may start moving in neutral.

The present invention has been made by paying attention to the above-mentioned problems, and an object of the present invention is to provide a vehicle control device capable of preventing an unintended movement of a vehicle without changing its structure.

The present invention detects a prime mover, an automatic transmission that shifts the rotation transmitted from the prime mover and transmits the rotation to the wheels, a shift range operation unit that performs a shift range switching operation on the automatic transmission, and a vehicle speed. The automatic transmission is hydraulically released when the shift range operation unit performs a switching operation from a traveling range in which the vehicle travels to a non-traveling range in which the vehicle does not travel. A vehicle control device including a clutch, the oil temperature acquisition unit that detects or estimates the oil temperature of the oil flowing through the frictional engagement element of the clutch, and the braking force acting unit that exerts a braking force on the wheels. The vehicle speed detecting unit indicates that the oil temperature is lower than the predetermined oil temperature and the vehicle is traveling at a vehicle speed lower than the predetermined vehicle speed. When the operation of switching from the traveling range to the non-traveling range is performed by the shift range operating unit in the detected state, a braking force is applied to the wheels, and the vehicle speed approaches 0. the braking force is controlled gradually larger Do so that the braking force acting portion and said.

As described above, according to the present invention, it is possible to prevent the vehicle from unintentionally starting to move without changing the structure.

FIG. 1 is a configuration diagram of a vehicle including a vehicle control device according to an embodiment of the present invention. FIG. 2 is a diagram showing a clutch of an automatic transmission provided in a vehicle provided with a vehicle control device according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating a braking operation while the vehicle is stopped by the vehicle control device according to the embodiment of the present invention. FIG. 4 is a timing chart for explaining the transition of the vehicle state when the braking operation while the vehicle is stopped of FIG. 3 is executed. FIG. 5 is a flowchart illustrating a braking operation during traveling by a vehicle control device according to an embodiment of the present invention. FIG. 6 is a timing chart for explaining the transition of the vehicle state when the braking operation during traveling of FIG. 5 is executed.

The vehicle control device according to the embodiment of the present invention performs a shift range switching operation for the prime mover, the automatic transmission that shifts the rotation transmitted from the prime mover and transmits the rotation to the wheels, and the automatic transmission. The shift range operation unit is provided with a shift range operation unit and a vehicle speed detection unit that detects the vehicle speed, and the automatic transmission is operated by the shift range operation unit to switch from a traveling range in which the vehicle travels to a non-traveling range in which the vehicle does not travel. A vehicle control device equipped with a clutch that is released by hydraulic pressure in some cases. An oil temperature acquisition unit that detects or estimates the oil temperature of the oil flowing through the frictional engagement element of the clutch, and a control that applies braking force to the wheels. It has a power acting unit and a control unit that controls a braking force acting unit, and the control unit is in a state where the vehicle speed detecting unit detects that the oil temperature is lower than the predetermined oil temperature and the vehicle is stopped. Therefore, when the operation of switching from the traveling range to the non-traveling range is performed by the shift range operating unit, the braking force acting unit is controlled so as to apply the braking force to the wheels. Thereby, the vehicle control device according to the embodiment of the present invention can prevent the vehicle from unintentionally starting to move without changing the structure.

Hereinafter, a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, the vehicle 10 includes an engine 20, an automatic transmission 30, wheels 12, an attitude control device 40, and a control unit 50 that comprehensively controls the vehicle 10.

A plurality of cylinders are formed in the engine 20. In this embodiment, the engine 20 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder.

The automatic transmission 30 shifts the rotation transmitted from the engine 20 and transmits the rotation after the shift to the wheels 12 via a drive shaft (not shown). The automatic transmission 30 includes a so-called step AT in which a planetary gear mechanism is used to shift gears in stages.

As shown in FIG. 2, the automatic transmission 30 includes an input shaft 35 into which the rotation of the engine 20 is input, a driven shaft 36 for transmitting the rotation to the planetary gear mechanism, and a clutch 37.

The clutch 37 is a wet multi-plate clutch, and includes a friction engaging element 35A connected to the input shaft 35 and a friction engaging element 36A connected to the driven shaft 36. The clutch 37 is a so-called forward clutch, which is engaged when the shift range is operated to the D range and released when the shift range is operated to the N range. Since the clutch 37 is a wet multi-plate type, oil flows between the friction engaging elements 35A and 36A. The automatic transmission 30 includes a plurality of clutches having a structure similar to that of the clutch 37, and by changing the combination of engagement or disengagement of the clutches, the power transmission path in the automatic transmission 30 is switched and the shift stage is changed. ..

In FIGS. 1 and 2, the control unit 50 includes an engine controller 50A that controls the engine 20 and a transmission controller 50B that controls the automatic transmission 30.

The engine controller 50A and the transmission controller 50B have a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, an input port, and the like. It is composed of a computer unit (ECU: Electronic Control Unit) provided with an output port.

The ROM of the computer unit stores various constants, various maps, and the like, as well as a program for operating the computer unit, and the CPU executes the program stored in the ROM using the RAM as a work area.

In the control unit 50, the engine speed, the accelerator opening degree, the throttle opening degree, the engine torque, and the air conditioner signal are transmitted from the engine controller 50A to the transmission controller 50B by CAN communication. In this embodiment, the functions are divided into the engine controller 50A and the transmission controller 50B, but these controllers may be integrated into one.

The engine 20 is provided with an engine rotation speed sensor 27, which detects the engine rotation speed generated by the engine 20 and controls the detection signal based on the rotation position of a crank shaft (not shown). It is transmitted to the engine controller 50A of the unit 50.

The engine 20 is provided with a throttle opening sensor 28, which detects the opening of a throttle valve (not shown) and transmits a detection signal to the engine controller 50A of the control unit 50.

The clutch 37 of the automatic transmission 30 is engaged and disengaged by the transmission controller 50B of the control unit 50 controlling according to the shift range. When the clutch 37 is engaged, the rotation of the input shaft 35 is transmitted to the driven shaft 36, and the driven shaft 36 rotates integrally with the input shaft 35. Further, when the clutch 37 is released, the input shaft 35 and the driven shaft 36 are disconnected, and the automatic transmission 30 is put into the neutral state.

The vehicle 10 is provided with a vehicle speed sensor 15, and the vehicle speed sensor 15 detects the vehicle speed and transmits a detection signal to the control unit 50.

Further, the vehicle 10 is provided with an accelerator opening sensor 16, which detects the amount of depression of an accelerator pedal (not shown) and transmits a detection signal as an accelerator opening to the control unit 50.

Further, the vehicle 10 is provided with a shift range operation unit 17, and the shift range operation unit 17 is for the driver to perform a shift range switching operation on the automatic transmission 30.

The attitude control device 40 is a device that controls the attitude of the vehicle 10 by applying a braking force to the wheels 12 when the vehicle 10 skids or the like. The attitude control device 40 is also called a skid prevention device, ESC (Electronic Stability Control) or ESP (Electronic Stability Program). The attitude control device 40 exerts a braking force on the wheels 12 not only when skidding or the like occurs but also when a brake request is made from the control unit 50.

In this embodiment, the engine 20 constitutes the prime mover according to the present invention, and the vehicle speed sensor 15 constitutes the vehicle speed detection unit according to the present invention. Further, the control unit 50 constitutes the oil temperature acquisition unit in the present invention, and the attitude control device 40 constitutes the braking force acting unit in the present invention.

Here, the oil circulating in the clutch 37 has a high viscosity in a low temperature environment. Therefore, immediately after the shift range is operated from the D range or the R range to the N range, dragging occurs due to the viscosity of the oil until the friction engaging elements 35A and 36B are sufficiently separated from each other, and the clutch 37 is engaged. Not completely released. Therefore, the opening operation of the clutch 37 may be delayed in a low temperature environment.

Further, when the oil temperature is low and the viscosity of the oil is high, the oil discharge rate becomes high when the valve of the hydraulic circuit is opened to open the friction engaging elements 35A and 36A in the engaged state and the oil is discharged. Since it is slow, the opening operation of the clutch 37 may be delayed.

Under these circumstances, when the oil viscosity is high in a low temperature environment, the driver shifts the shift range from the traveling range (for example, D range or R range) to the non-traveling range (for example, N range) with the shift range operation unit 17. When the vehicle 10 is switched to and the foot is released from the brake pedal, the vehicle 10 may unintentionally start moving.

Therefore, in this embodiment, the control unit 50 applies a braking force to the wheels 12 in a situation where it is assumed that the vehicle 10 unintentionally starts to move due to the high viscosity of the oil.

The control unit 50 operates the shift range to switch from the traveling range to the non-traveling range while the vehicle speed sensor 15 detects that the oil temperature of the oil is lower than the predetermined oil temperature and the vehicle 10 is stopped. When performed by the unit 17, a braking operation while the vehicle is stopped is performed, which controls the attitude control device 40 so as to apply a braking force to the wheels 12.

Here, the control unit 50 also functions as an oil temperature acquisition unit that detects or estimates the oil temperature of the oil flowing between the friction engaging elements 35A and 36A of the clutch 37. For example, the control unit 50 can detect the oil temperature of oil by an existing oil temperature sensor in the automatic transmission 30 or a newly provided oil temperature sensor. Alternatively, the control unit 50 estimates the oil temperature of the oil based on the vehicle condition and the like.

Further, the control unit 50 can switch from the traveling range to the non-traveling range while the vehicle speed sensor 15 detects that the oil temperature is lower than the predetermined oil temperature and the vehicle is traveling at the predetermined vehicle speed. When performed by the shift range operation unit 17, a braking force is applied to the wheels 12, and a braking operation during traveling is performed in which the attitude control device 40 is controlled so that the braking force gradually increases as the vehicle speed approaches zero.

The braking operation while the vehicle is stopped by the control unit 50 of the vehicle 10 configured as described above will be described with reference to the flowchart shown in FIG. This operation is repeated in a short cycle during system startup.

In FIG. 3, the control unit 50 determines in step S1 whether or not the oil temperature of the clutch 37 of the automatic transmission 30 is equal to or lower than the threshold value. If the oil temperature is greater than the threshold value in step S1, the control unit 50 ends the current operation, and if the oil temperature is equal to or less than the threshold value, whether or not the vehicle speed V is 0 [km / h] in step S2. To determine. That is, the control unit 50 determines whether or not the vehicle 10 is stopped.

If the vehicle speed is not 0 [km / h] in step S2, the control unit 50 ends this operation, and if the vehicle speed is 0 [km / h], the control unit 50 ends the D range or R range to N range in step S3. Determines if a shift operation has been performed to.

The control unit 50 ends the current operation when the shift operation to the N range is not performed in step S3, and activates the brake in step S4 when the shift operation to the N range is performed.

In step S4, the control unit 50 controls the attitude control device 40 so as to apply a braking force to the wheels 12. Then, the braking force is released after the predetermined time T1. The predetermined time T1 is set to a sufficient time to prevent the vehicle 10 from starting to move.

Next, with reference to the timing chart of FIG. 4, the transition of the vehicle state when the braking operation while the vehicle is stopped of FIG. 3 will be described. In FIG. 4, the vertical axis represents the vehicle speed, the shift range (denoted as the shift position in the figure) and the braking force, and the horizontal axis represents the time. The braking force "ON" in FIG. 4 indicates that the control unit 50 controls the attitude control device 40 so as to apply the braking force to the wheels 12. Therefore, the braking force due to the braking operation of the driver is not shown in FIG.

As shown in FIG. 4, at time t0, the vehicle speed is reduced by the braking operation of the driver, the shift range is set to the D range, and the braking force is turned off.

After that, at time t1, the vehicle speed becomes 0 and the vehicle 10 stops. After that, since the shift range was switched to the N range by the driver at time t2, the braking force was turned on at time t3.

Next, the braking operation during traveling by the control unit 50 will be described with reference to the flowchart shown in FIG. This operation is repeated in a short cycle during system startup.

In FIG. 5, the control unit 50 determines in step S11 whether or not the oil temperature of the clutch 37 of the automatic transmission 30 is equal to or lower than the threshold value. If the oil temperature is greater than the threshold value in step S11, the control unit 50 ends the current operation, and if the oil temperature is equal to or less than the threshold value, the vehicle speed V is less than the predetermined vehicle speed Vth [km / h] in step S12. Determine if it is.

If the vehicle speed is not less than the predetermined vehicle speed Vth [km / h] in step S12, the control unit 50 ends the current operation, and if the vehicle speed is less than 0 [km / h], the control unit 50 ends the D range or R in step S13. It is determined whether or not the shift operation from the range to the N range has been performed.

The control unit 50 ends the current operation when the shift operation to the N range is not performed in step S13, and activates the brake in step S14 when the shift operation to the N range is performed. In step S14, the control unit 50 controls the attitude control device 40 so as to apply a braking force to the wheels 12. Then, the braking force is released after the predetermined time T2. The predetermined time T2 is set to a sufficient time to prevent the vehicle 10 from starting to move after the vehicle has stopped.

Next, with reference to the timing chart of FIG. 6, the transition of the vehicle state when the braking operation during traveling of FIG. 5 is performed will be described. In FIG. 6, the vertical axis represents the vehicle speed, the shift range (denoted as the shift position in the figure) and the braking force, and the horizontal axis represents the time. The braking force "ON" in FIG. 6 indicates that the control unit 50 controls the attitude control device 40 so as to apply the braking force to the wheels 12. Therefore, the braking force due to the braking operation of the driver is not shown in FIG.

As shown in FIG. 6, at time t10, the vehicle speed is reduced by the braking operation of the driver, the shift range is set to the D range, and the braking force is turned off. After that, at time t11, the shift range is switched to the N range by the driver.

After that, since the vehicle speed drops to the predetermined vehicle speed Vth at time t12, the braking force is turned on, and the braking force is gradually increased as the vehicle speed decreases. After that, at time t13, the vehicle speed becomes 0 and the vehicle 10 stops.

As described above, in the present embodiment, the control unit 50 is in a state where the vehicle speed sensor 15 detects that the oil temperature of the oil of the automatic transmission 30 is lower than the predetermined oil temperature and the vehicle 10 is stopped. When the shift range operation unit 17 performs the operation of switching from the traveling range to the non-traveling range, the attitude control device 40 is controlled so as to apply a braking force to the wheels 12.

As described above, in this embodiment, the operation of switching from the traveling range to the non-traveling range is performed in a state where the vehicle speed sensor 15 detects that the oil temperature of the oil is lower than the predetermined oil temperature and the vehicle is stopped. If this is done, the control unit 50 controls the attitude control device 40 so that the braking force is applied to the wheels 12 even when the driver's braking operation force is not sufficient, so that the vehicle 10 unintentionally starts to move. Can be prevented.

Further, in the present embodiment, since the control unit 50 is controlled to prevent the vehicle 10 from unintentionally starting to move, it is not necessary to change the structure such as providing a separate clutch on the automatic transmission 30.

As a result, it is possible to prevent the vehicle 10 from unintentionally starting to move without changing the structure.

Further, in the present embodiment, the control unit 50 changes from the traveling range to the non-traveling range in a state where the vehicle speed sensor 15 detects that the oil temperature is lower than the predetermined oil temperature and the vehicle is traveling at the predetermined vehicle speed. When the shift range operation unit 17 performs the switching operation to, the braking force is applied to the wheels 12, and the attitude control device 40 is controlled so that the braking force gradually increases as the vehicle speed approaches zero.

As a result, when the driver switches from the traveling range to the non-traveling range with the intention of stopping after decelerating while the vehicle 10 is decelerating, the wheels 12 are controlled before the vehicle speed drops to 0. Since the power acts, when the driver takes his foot off the brake pedal after the vehicle speed becomes 0, a sufficient braking force for preventing the vehicle 10 from starting to move can be applied to the wheels 12. Therefore, it is possible to prevent the vehicle 10 from unintentionally starting to move after stopping.

As a result, it is possible to prevent the vehicle 10 from unintentionally starting to move without changing the structure. In addition to this, in the present embodiment, the braking force gradually increases as the vehicle speed approaches 0, so that it is possible to prevent the driver from feeling uncomfortable or uncomfortable at the start of braking and during braking.

Although the embodiments of the present invention have been disclosed, it is clear that some skilled in the art can make changes without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

10 Vehicle 12 Wheels 15 Vehicle speed sensor (Vehicle speed detector)
17 Shift range operation unit 20 Engine (motor)
30 Automatic transmission 35A, 36A Friction engagement element 37 Clutch 40 Attitude control device (braking force acting part)
50 Control unit (control unit, oil temperature acquisition unit)

Claims (1)

The prime mover and
An automatic transmission that shifts the rotation transmitted from the prime mover and transmits it to the wheels.
A shift range operation unit that switches the shift range for the automatic transmission, and a shift range operation unit.
Equipped with a vehicle speed detection unit that detects vehicle speed,
The automatic transmission is a vehicle control device including a clutch that is released by flood control when a switching operation from a traveling range in which the vehicle travels to a non-traveling range in which the vehicle does not travel is performed by the shift range operation unit. There,
An oil temperature acquisition unit that detects or estimates the oil temperature of the oil flowing through the frictional engagement element of the clutch.
A braking force acting unit that exerts a braking force on the wheels,
It has a control unit that controls the braking force acting unit, and has a control unit.
The control unit
While the vehicle speed detection unit has detected that the oil temperature is lower than the predetermined oil temperature and the vehicle is traveling at a speed lower than the predetermined vehicle speed , the operation of switching from the traveling range to the non-traveling range is the shift. When done by the range control unit
Control device for a vehicle, wherein the wheel by the action of braking force to the braking force is controlled gradually larger Do so that the braking force acting portion As the vehicle speed approaches zero.

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