JPH01240329A - Device for controlling starting of vehicle with continuously variable transmission - Google Patents

Abstract

PURPOSE:To secure excellent starting performance at the time of forwarding as well as excellent control performance at the time of reversing concurrently by prohibiting driving power from being increased at the time of reversing when starting acceleration performance is improved with driving power tentative ly increased at the time of starting. CONSTITUTION:A vehicle is equipped with an continuously variable transmission B transmitting the output of an engine A to driving wheels C via a torque converter B1 and a speed change gear mechanism B2. In this case, a means D detecting vehicle starting and a means E increasing tentatively driving power to be transmitted to the driving wheels C based on the output from the means D are provided respectively. And a means F detecting the shift range of the continuously variable transmission and a means G prohibiting the means E from increasing driving power when the shift to the reverse range is detected by the means F are provided respectively. This constitution allows the vehicle to be started by relatively small driving power corresponding to the accelerator pedal footing by a driver, thereby obtaining excellent controllability.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle equipped with an automatic transmission, and particularly to a start control device that improves the start performance of this type of vehicle.

(Prior art) An automatic transmission for a vehicle combines a torque converter and a speed change gear mechanism, and switches the power transmission path of the speed change gear mechanism by selectively operating a plurality of friction engagement elements, thereby changing the transmission path according to the driving condition. When the vehicle is started, the gear is automatically set to the gear with the largest reduction ratio, that is, the first gear.

Furthermore, in this type of automatic transmission, due to the torque increasing effect of the torque converter, the engine output is increased and input to the transmission gear mechanism during high loads such as when starting, and this torque increasing effect Due to this and the deceleration effect of the speed change gear mechanism, a large driving force is transmitted to the driving wheels at the time of starting, and the required starting acceleration force is obtained.

Regarding the torque increasing effect of the torque converter, for example, as described in Japanese Patent Application Laid-Open No. 6i130659, the torque increasing rate can be increased by changing the angle of the stator in the torque converter that performs this effect using an actuator. , that is, a system in which the torque ratio is controlled according to the operating state is known. According to this, by temporarily increasing the torque ratio at the time of starting, it is possible to further improve the starting acceleration performance without deteriorating the power transmission efficiency or the fuel efficiency of the engine during normal driving, for example. Good starting performance can be obtained even in heavy vehicles.

(Problem to be solved by the invention) By the way, as in the invention described in the above publication, the torque ratio of the torque converter is increased at the time of starting, or the driving force is temporarily increased by other methods. case,
During a normal forward start, the acceleration force is increased and good start performance is obtained, but when the vehicle is started backward, the increased acceleration force may deteriorate the maneuverability of the vehicle. In other words, if a large acceleration force is generated when starting in reverse, which is difficult to operate compared to when moving forward, it becomes even more difficult to operate the vehicle.When reversing, easier maneuverability is required than the large acceleration force when starting. be.

Therefore, the present invention improves starting acceleration performance by temporarily increasing the driving force when starting, and by prohibiting this driving force increase control when starting backward, it is possible to improve starting performance when moving forward and improve starting acceleration performance when moving backward. The purpose is to obtain good maneuverability at certain times.

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized by the following configuration.

That is, as shown in FIG. 1, in a vehicle equipped with an automatic transmission B that transmits the output of an engine A to drive wheels C1C via a torque converter B0 and a speed change gear mechanism B2, a starting operation of the vehicle is detected. Starting operation detection means,
a driving force increasing means E for temporarily increasing the driving force transmitted to the drive wheels c, c when a starting operation is detected by the detection means, and a shift range of the automatic transmission B; A shift range detecting means F for detecting the shift range and a driving force increase inhibiting means G for inhibiting the driving force increasing control by the driving force increasing means E when the detecting means F detects a shift to the reverse range are provided.

Here, as the driving force increasing means E, in addition to changing the stator angle of the torque converter as described above,
A system that holds the brake device in an activated state during a starting operation by pressing the accelerator pedal, putting the torque converter in a so-called stall state, or slipping a friction engagement element that is engaged at the starting gear in an automatic transmission to increase engine rotation. There are things that can increase the number.

(Function) According to the above configuration, when the starting operation of the vehicle is detected by the starting operation detection means, the driving force transmitted to the driving wheels C1C is temporarily increased by the driving force increasing means E. As a result, a large acceleration force is obtained when starting the vehicle, but when starting in reverse, the shift range detection means F detects that the range of the automatic transmission B is shifted to the reverse range. Accordingly, the driving force increase inhibiting means G prohibits the driving force increasing means E from controlling the increase in driving force. Therefore, in this case, the vehicle starts with a relatively small driving force corresponding to the driver's accelerator operation, and thereby good maneuverability when reversing is obtained.

(Example) Examples of the present invention will be described below.

First, the first embodiment of the present invention will be explained. In this embodiment, when starting, the brake device is temporarily held in an operating state and the torque converter is brought into a stall state to increase the driving force. As shown in FIG. 2, the vehicle 1 according to this embodiment has left and right front wheels 2.3.
is the driven wheel, and the left and right rear wheels 4 and 5 are the driving wheels, and the output of the engine 6 is transmitted to the rear wheels 4 and 5 as the driving wheels, the automatic transmission 7, the propeller shaft 8, the differential gear 9, and the left and right rear wheels. The power is transmitted via the drive shaft 10.1). In addition, the left and right front wheels 2 and 3 and the left and right rear wheels 4 and 5 have the following:
Disc rotors 12a to 15 that rotate together with these
a, and calipers 12b to 15 that brake the rotation of the disc rotors 12a to 15a when brake pressure is supplied.
Brake devices 12, 13 and 14, 15 are respectively provided, and when the brake pedal 16 is depressed,
Brake pressure generated by the mask cylinder 17 is supplied to each of the brake devices 12 to 15 through a brake system 20. Here, the above brake system 2
0 has a first system 21 connected to the first discharge hole 17a of the mask cylinder 17 and a second system 22 connected to the second discharge hole 17b, and the first system 21 applies the brake of the left front wheel 2. A second system 22 is connected to the brake system 12 and the brake system 15 of the right rear wheel 5, and a second system 22 is connected to the brake system 13 of the right front wheel 3 and the brake system 14 of the left rear wheel 4, respectively. and,
Branch line 22a leading to the left rear wheel brake device 14 of the second system 22 and the right rear wheel brake device 1 of the first system 21
Brake pressure control valves 23.24 that control the supply of brake pressure to these brake devices 14.15 are installed in the branch lines 21a leading to the brake equipment 14.5, and actuators that operate these control valves 23.24, respectively, are installed. 25.26 are provided.

On the other hand, this vehicle 1 is equipped with a control unit 30 that performs shift control of the automatic transmission 7 and brake control at the time of starting. This control unit 30 includes
When the signal a from the vehicle speed sensor 31 that detects the vehicle speed and the signal from the throttle opening sensor 33 that detects the opening of the throttle valve 32 provided in the intake passage of the engine 6 are received, the automatic transmission 7 is provided with a signal a. Position of shift lever 34 (
A signal C from the shift range sensor 35 that detects the range), a signal d from the brake sensor 36 that detects the depression operation of the lever 16 to the brake, and a signal d from the brake system 20.
A signal e from the brake pressure sensor 37 that detects the hydraulic pressure downstream of the brake pressure control valve 23 (and 24) at
Furthermore, a signal f from a tilt sensor 38 that detects the degree of tilt of the vehicle 1 is input. Based on these signals a to f, the control unit 30 outputs a shift control signal g to the automatic transmission 7 in order to control the shift of the automatic transmission 7, and also performs brake control at the time of starting. To do this, the brake pressure control valve 23.24
A brake control signal is sent to the actuators 25 and 26 of h.
, and further outputs a lock release signal i (see FIG. 4) to a shift lock device 50, which will be described later.

Here, to briefly explain the shift control operation of the control unit 30, when the shift range indicated by the signal C is a forward range in which automatic shifting is performed, such as the D range, the control unit 30 uses the signals a and b. The vehicle speed indicated by and the throttle opening of the engine are compared with a preset shift map to determine the gear position according to the driving condition at that time, and the gear shift control signal g is outputted to select this gear position. do. Further, when the shift range is the R range, the signal g is outputted so that a reverse gear stage can be obtained.

Next, the configuration of the brake pressure control valve 23.24 and its actuator 25.26 will be explained with reference to FIG. 3.The brake pressure control valve 23.24 according to this embodiment is for the left rear wheel and the right rear wheel. It is possible to increase/decrease and maintain the brake pressure supplied to the brake device 14.15,
Pistons 23b and 24b are fitted into the cylinders 23a and 24a to define the insides of these cylinders 23a and 24a into variable volume chambers 23c and 24c and control chambers 23d and 24d, and the pistons 23b and 24b are connected to springs 23 and 24a.
e and 24e bias the variable volume chambers 23c and 24c in a direction to increase their volumes. The branch line 22a of the second system 22 from the mask cylinder 17 to the brake device 14 for the left rear wheel and the branch line 21a of the first system 21 to the brake device 15 for the right rear wheel are connected to the variable volume chambers 23c, 24c. The brake pressure normally generated by the mask cylinder 17 is supplied to the left and right rear wheel brake devices 14 and 15 through these variable volume chambers 23c and 24c. Further, the pistons 23b and 24b include a control chamber 23d,
The control pressure introduced into 24d causes the piston 23b,
When 24b moves in a direction in which the volumes of variable volume chambers 23c and 24c decrease against springs 23e and 24e,
A check valve 23f closes the brake pressure inlet to these variable volume chambers 23c and 24c.

24f is provided.

On the other hand, actuators 25 and 26 that actuate these brake pressure control valves 23 and 24 are respectively composed of pressure increasing solenoid valves 25ia and 26a and pressure reducing solenoid valves 25b and 26b. 25b, 26b
is composed of a duty solenoid valve that is periodically controlled to turn ON and OFF at a predetermined ON and FF ratio (duty rate). In addition, the pressure increasing solenoid valves 25a, 2
6a is the control chamber 23d, 24 of the brake pressure control valve 23.24 from the oil pump 40 via the relief valve 41.
The pressure reducing solenoid valves 25b and 26b are respectively arranged on drain lines 44.45 led from the control chambers 23d and 24d. And these solenoid valves 2
5a, 26a, 25b, 26b are controlled to open and close by the brake control signal h from the control unit 30, and when the pressure increasing solenoid valves 25a, 26a are opened and the pressure reducing solenoid valves 25b, 26b are shut off, Control pressure is introduced into the control chambers 23d, 24d of the brake pressure control valves 23, 24, and the pistons 23b, 24b are activated by the spring 23.
By moving in the direction in which the volumes of the variable volume chambers 23c and 24c decrease against the pressures e and 24e, the brake pressure supplied to the brake device 14.15 is increased, and in this state, the pressure increase solenoid valve is When 25a and 26a are closed,
The brake pressure supplied to the brake devices 14, 15 is maintained. Furthermore, the pressure increase solenoid valves 25a and 26a are shut off, and the pressure decrease solenoid valves 25b and 2
6b is opened, the brake device 14 is discharged by discharging the control pressure from the control chambers 23d and 24d.
The brake pressure that had been supplied to
As described above, the brake pressure is reduced by this pressure reducing solenoid valve 25b.

This is done by duty control of 26b.

In this embodiment, the automatic transmission 7 is equipped with a shift lock device W50. This device 50 is
As shown in Figure 4, the shift lever 3 is fixed to the vehicle body.
A daytent groove 51a for neutral (and parking) is provided in the daytent plate 51 that regulates the position of 4.
This groove 5 is formed in the shift lever 34.
This configuration includes a lock pin 52 that can be engaged with and detached from 1a, and a solenoid 53 that operates the lock pin 52. Then, when the brake pedal 16 is depressed, a lock release signal i is inputted from the control unit 30 to the solenoid 53 to disengage the lock pin 52 from the detent groove 51a=13-. It is now possible to perform a shift operation.

Next, the operation of this embodiment will be explained with reference to the flowchart of FIG. 5 showing the operation of the control unit 30 at the time of starting.

First, the control unit 30 detects the shift range sensor 3 in step S1 when the vehicle is stopped.
The shift range of the automatic transmission 7 is determined based on the signal C from the brake sensor 36, and when the automatic transmission 7 is in a non-driving range such as the N range or the P range, the signal d from the brake sensor 36 is determined in step S2.
It is determined whether the brake pedal 16 is depressed. If the brake pedal 16 is not depressed, in step S3, the shift lock device 50 shown in FIG. When the pedal 16 is depressed, a lock release signal i is output to the solenoid 53 of the device 50 in step S4, allowing the shift lever 34 to be operated into the travel range.

Next, the control unit 30 determines the shift range of the automatic transmission 7 again based on the signal C from the shift range sensor 35 in step S5, and further determines the shift range of the automatic transmission 7 from the tilt sensor 38 in step S6 when the shift operation is performed to the driving range. The degree of inclination of the vehicle is determined based on the signal f of
The vehicle speed of the vehicle is determined by Then, when the vehicle speed is less than a relatively small predetermined value ■o, that is, when the vehicle is stopped or in a very low speed state before the starting operation is completed, the throttle opening sensor 33 is further activated in step S8.
The current detected value θ and the previous detected value θ' of the throttle opening indicated by the signal from the In S9, the shift range of the automatic transmission 7 is detected again using the signal C from the shift range sensor 35. When the shift range is in a forward range other than the R range, a signal e from the brake pressure sensor 37 is sent to the rear wheel brake system 1 in step S1o.
After confirming that brake pressure is supplied to 4 (and 15), proceed to step S1). The brake control flag F is set to 1 according to S12, and the third
The duty ratio of the brake control signals h' and h' for controlling the pressure reducing solenoid valves 25b and 26b shown in the figure is set to 100%. Thereafter, in step S13, the control signals h' and h' are outputted so as to operate the pressure reducing solenoid valves 25b and 26b at this duty rate. Here, the pressure reducing solenoid valves 25b and 26b are fully closed when the duty rate is 100%, as shown in FIG.
The control pressure is trapped in the rear wheel brake device 14.15, and the rear wheel brake devices 14.15 are maintained in a state where brake pressure is supplied, that is, in a state where these brake devices 214.15 are operated.

When a start operation is performed by depressing the accelerator pedal in this state, the throttle opening changes and the current detected value θ becomes larger than the previous detected value θ'. After confirming that the brake control flag F is 1 by executing the above, in step S15, it is determined whether the current detected value θ of the throttle opening becomes larger than the previous detected value θ', that is, the moment when the starting operation is started. Determine whether or not. In this case, since this is the moment when the start operation is started, the control unit 30 determines the delay time T from the start of the start operation to the start of the brake release operation, the release speed at the time of brake release, 6D(1 (amount of decrease in duty rate with respect to control cycle). In that case, the delay time T and release speed AD are the function value f(θ
)1g(θ), and the delay time T is shortened as the throttle opening θ increases at a predetermined throttle opening θ1 or more as shown in FIG. 7, and the effective release speed ΔD is set as shown in FIG. The throttle opening angle is set to increase (faster) as the opening angle θ increases within a predetermined throttle opening angle range θ2 to θ3.

Then, the control unit 30 next performs step S.
At step 17, it is determined whether or not the set time (delay time) T is O. Immediately after starting the start operation, the time T is not O, so at step 818, 1 is subtracted from the time T. Execute the above step S12+813,
The duty ratio is maintained at 100%, that is, the brake devices 14 and 15 are kept in operation. This state is
The subtraction processing of the set time T in step S18 continues until the time T becomes 0, in other words, until the delay time set according to the throttle opening θ has elapsed from the start of the start operation, and during this time, the As shown in FIG. 9, the vehicle speed is maintained at O even though the engine speed increases due to the increase in throttle opening, and in the automatic transmission 7, the torque converter 7a shown in FIG. 2 is in a stall state. Therefore, the engine output is transmitted at a large torque ratio from the speed change gear mechanism 7b to the rear wheels 4.5 as driving wheels.

When the set time T elapses in this state, the control unit 30 executes steps S17 to S19 and determines whether the duty rate is 0 or not. is 100%
However, the control unit 30 then performs step S.
20, and from this duty rate, perform step S
The reduction amount (brake release speed) ΔD set in step SI3 is subtracted, and a control signal h' is sent to the pressure reducing solenoid valves 25b and 26b at the subtracted duty rate in step SI3.
, h'. By repeating this step S20, the duty rate is gradually reduced. At the same time, the pressure reducing solenoid valves 25b and 26b gradually approach the fully open state, so that the brake pressure control valve 23 Control room 23d at .24,
The control pressure in 24d is gradually discharged and the brake pressure supplied to the brake device 14.15 is gradually reduced, thus releasing the brake device 14.15. Then, the vehicle starts moving by releasing the brake devices 14 and 15.

In that case, if the shift range of the automatic transmission 7 is shifted to a driving range other than the R range, such as a forward range such as the D range, the engine speed will be high at the time of starting, and the torque will be higher. Since the converter 7a is in a stall state and the torque ratio increases, the vehicle starts with a large acceleration force. However, when the gear is shifted to the R range, steps S9 to S2 in the flowchart of FIG. , S22 are executed, and the control to increase the driving force or acceleration force by maintaining the brake devices 14, 15 in the operating state as described above is not performed. As a result, when starting in reverse, the vehicle starts with a relatively small driving force corresponding to the driver's accelerator operation, resulting in good maneuverability.

In addition, in the driving force increase control at the time of starting in the forward range, when the duty rate becomes 0 due to the duty rate subtraction process in step S20, or when the vehicle starts and exceeds the predetermined vehicle speed vo. At times, the control unit 30 executes steps S2□ and S2□, resets the brake control flag F to 0, clears the duty rate to 0, and ends this driving force increase control.

In addition, in this driving force increase control, as mentioned above,
The larger the throttle opening θ, the shorter the delay time T from the start of the start operation to the start of the brake release operation, and the faster the release speed (/D) when the brake is released.
When the engine output is low and the throttle opening is low, the torque converter remains stalled for a long time and is released slowly, resulting in a correspondingly large starting acceleration force. When the throttle opening is high, which increases the engine output, the stall state of the torque converter is released relatively early, and the release speed is also increased, thereby avoiding unnecessarily prolonging the stall state.

Next, as another embodiment of the present invention, an embodiment will be described in which the driving force is increased by temporarily slipping a predetermined friction engagement element in the automatic transmission when starting in the forward range.

As shown in FIG. 10, automatic transmission 7 according to this embodiment
' is a speed change gear mechanism 7 consisting of a torque converter 7a' connected to the engine output shaft A and a Lavigne type planetary gear driven by the output of the torque converter 7a'.
b', a plurality of frictional engagement elements 61 to 66 such as clutches and brakes, and first and second one-way clutches 67 and 68 for switching the power transmission path of the mechanism 7b'.

Here, the frictional engagement elements include a forward clutch 61, a coast clutch 62, a 3-4 clutch 63,
A reverse clutch 64.2-4 brake 65 and a low reverse brake 66 are provided.

Then, as shown in Table 1, P, R, N, and D depending on the selective operation of these frictional engagement elements 61 to 66 and one-way clutches 67 and 68.

2.1, 1st to 4th speeds in the D range, 1st to 3rd speeds in the 2nd range, and 1st to 2nd speeds in the 2nd range are obtained, as is clear from this table. In the forward gear stage, the forward clutch 61 is always engaged.

(Hereinafter, blank space) This automatic transmission 7' also includes the above-mentioned frictional engagement elements 6.
A hydraulic control circuit is provided to control the engagement and disengagement operations of the forward clutches 1 to 66. Of this circuit, the part that controls the working hydraulic pressure, that is, the line pressure, supplied to the forward clutch 61 is shown in Figure 1). It is configured as follows.

In other words, this hydraulic control circuit controls the pressure of hydraulic oil discharged into the main line 71 from the oil pump 70 (see FIG. 10), which is constantly driven by the engine output shaft A via the torque converter 7a', to a predetermined line. A regulator valve 80 is provided to adjust the pressure. This regulator valve 80 has a main spool 81 and an auxiliary spool 8.
2, and a spring 83 that urges the main spool 81 to the right in the drawing. A pressure regulating boat 84 is provided at the center of the main spool 81 and is connected to the main line 71. At the right end of the main spool 81 in the drawing, a pressure regulating boat 84 is also connected to the main line 71. A control boat 25-85 is provided for applying the hydraulic pressure in the line 71 to the right end of the main spool 81, and a drain boat 86 is provided between these boats 84 and 85. Further, a pilot pressure boat 87 is provided at the left end of the auxiliary spool 82 in the drawing, and a pilot pressure port 87 is connected to a pilot pressure line led from the main line 71 via the reducing valve 72. A drain line 74 is connected to the pilot pressure line 73, and a duty solenoid valve 75 is installed on the drain line 74. By controlling the duty solenoid valve 75, the pilot pressure acting on the left end of the auxiliary spool 82 in the regulator valve 80 is adjusted.

Therefore, according to this regulator valve 80, the hydraulic pressure in the main line 71 and the pilot pressure whose hydraulic pressure is adjusted by the spring force and the duty solenoid valve 75 act on the main spool 81, and the above-mentioned By communicating and cutting off the pressure regulating boat 84 with respect to the drain boat 86, the oil pressure within the pressure regulating boat 84 or the main line 71, that is, the line pressure, is controlled. In that case, as shown in Figure 12,
The higher the duty rate of the duty solenoid valve 75, the closer the valve 75 is to a fully closed state, and the amount of drain from the drain line 74 decreases, resulting in a higher pilot pressure or line pressure, and conversely, the duty rate increases. The smaller the value, the lower the pilot pressure or line pressure.

The line pressure adjusted as described above is guided to the manual valve 76 by the main line 71, and is passed through the manual valve 76 and a shift valve (not shown) to each of the frictional engagement elements 61 to 66 shown in FIG. As a result, the gear position is controlled according to the table shown in Table 1 above, when the manual valve 76 is in the D range as shown in the figure (the same applies when it is in the 2nd and lunge). The above line pressure is always supplied to the forward clutch 61.

Furthermore, this automatic transmission 7' is equipped with a control unit 90 as shown in FIG. A throttle opening sensor 92 detects the throttle opening of the engine according to the signal.
, a signal p from the engine rotation speed sensor 93 that detects the engine rotation speed, a signal n from the shift range sensor 94 that detects the shift range of the automatic transmission 7', and the slope of the vehicle. Tilt sensor 9 that detects
The signal 0 from 5 is input. The control unit) 90 operates a plurality of electromagnetic actuators 96...96 provided in the hydraulic control circuit 50 in order to control the gear stage of the automatic transmission 7' based on the input signals 0 to 0. It is designed to output a speed change control signal p to the above-mentioned duty solenoid valve 75, and also to output a hydraulic control signal q for adjusting the line pressure control pressure. It has become.

Next, the hydraulic control operation of the control unit 90 at the time of starting will be explained according to the flowchart of FIG. 14.

First, the control unit 90 performs step S'51.
The shift range of the automatic transmission 7' is determined based on the signal n from the shift range sensor 94, and if the shift range is not the R range, then it is determined in step S52 whether or not the shift range is the D range. In the case of the D range, the degree of inclination of the vehicle or the road surface is further determined in step S53 based on the signal 0 from the inclination sensor 95, and if this is less than a predetermined value α and the road surface is approximately flat, then Step S5
At step 4, the current vehicle speed is determined based on the signal k from the vehicle speed sensor 91. When the vehicle speed is less than a very small predetermined value ■o, that is, when the vehicle has not yet started,
Furthermore, in step S55, the current detected value θ of the throttle opening indicated by the signal 1 from the throttle opening sensor 92 is compared with the previous detected value θ', and when the two are equal, that is, the start operation by depressing the accelerator pedal is performed. If it has not been done yet, the basic duty rate, which will be described later, is determined in step S56. Set the correction coefficient K to 1. Then, when the accelerator pedal is depressed to start the vehicle, the control unit 90 determines in step S55 that the current detected value θ of the throttle opening is larger than the previous detected value θ'. Next, step S57 is executed, and the built-in timer is set to measure the elapsed time t from the start of the start operation, and in step S't8, the throttle opening degree θ at that point is less than or equal to the set value θ0. If it is determined, the correction coefficient K is set to a function value F (N) of the engine rotation speed N in step S59. In that case, this function value F (N) is equal to the idle rotation speed N, as shown in FIG. The lower limit value ko is a very small value of 1 or less up to the first set rotation speed Nl which is slightly higher, and from the first set rotation speed N to the second set rotation speed N2 which is higher than this.
It is set to increase from the lower limit value ko to 1 as the engine rotational speed N rises until then, and is further fixed at 1 at a second set rotational speed N2 or higher by ~30-.

Further, if the vehicle starts by pressing the accelerator pedal and the vehicle speed becomes higher than the predetermined value vo, the control unit 90 executes steps S54 to S60 to increase the elapsed time from the start of the starting operation. It is determined whether the predetermined time T has been reached, and if the predetermined time T has not been reached, 1 is added to the elapsed time t in step S6□, and steps 858 and 859 are repeatedly executed.

Then, when the predetermined time T has elapsed from the start of the start operation, steps S60 to S62 are executed to set the correction coefficient K to 1 again.

In this way, when the automatic transmission 7' is shifted to the D range, the control unit 90 controls the control unit 90 before starting, before the predetermined time T has elapsed from the start of the start operation, and after the predetermined time T has elapsed. The value of the correction coefficient is set according to each stage, and then the line pressure is controlled using this correction coefficient K.

That is, the control unit 90 performs step 86B.
The basic duty rate Do of the duty solenoid valve 75 corresponding to the current throttle opening degree θ is determined by the 16th
Calculations are performed based on a preset map as shown in the figure. In that case, this map increases the basic duty rate Do up to a predetermined throttle opening θ1' as the opening θ increases, and increases to 100% at a predetermined throttle opening θ,' or more.
DMAX is set to be fixed at a maximum value close to . Then, in step S64+865, the basic duty rate Do is multiplied by the correction coefficient K to calculate a final duty rate, and the hydraulic control signal q is sent to operate the duty solenoid valve 75 at this duty rate. Output.

As a result, 1) the pilot pressure supplied to the regulator valve 80 shown in FIG.
The line pressure controlled by 0 is controlled to a value corresponding to the above-mentioned final duty rate, but before the vehicle starts and after the predetermined time T has elapsed from the start of the starting operation, the line pressure is controlled as described above. The correction coefficient K is set to 1, and the final duty rate and the basic duty rate are calculated. Since these are equal, the line pressure is controlled so that it changes with the same characteristics as the basic duty rate Do shown in FIG. 16 with respect to the throttle opening θ. In that case, the predetermined throttle opening θ1'
Up to this point, since the basic duty rate Do increases as the opening degree θ increases, the line pressure also increases as the throttle opening degree θ increases, and each friction engagement element 61 to 6 shown in FIG.
The fastening force No. 6 corresponds to the torque transmitted by these according to the amount of depression of the accelerator pedal. In addition, when the accelerator pedal is not depressed before starting, in a driving range such as D range, the required line pressure is supplied to the forward clutch 61, although the oil pressure is relatively low, and the automatic transmission transmits power. Therefore, so-called creep running becomes possible.

On the other hand, the basic duty rate remains the same until the predetermined time T elapses after starting the vehicle by pressing the accelerator pedal.

Since the correction coefficient K for the engine speed N is set to a value of 1 or less as shown in FIG. 15, the final duty ratio also becomes a value smaller than the value shown in FIG. 16. Along with this, the line pressure controlled by the regulator valve 80 also becomes lower than before or after the predetermined time T has elapsed for the same throttle opening. Therefore, the forward clutch 61, which is in the engaged state in 1st gear at the time of starting, will slip due to insufficient engagement force relative to the transmitted torque, and this will reduce the load acting on the engine and reduce the pressure on the accelerator pedal. The engine rotational speed increases to a higher rotational speed for a constant amount of depression. In this manner, when the automatic transmission is shifted to the D range, the vehicle starts with the engine speed being high, the driving force is increased, and good starting acceleration performance is obtained.

On the other hand, when the automatic transmission is shifted to the R range, the control unit 90 performs step S5□
Since step S62 is executed to set the correction coefficient K to 1, the control to increase the engine speed or driving force by decreasing the line pressure and slipping the forward clutch 61 as described above is not performed. The embodiment also provides good maneuverability when starting in reverse.

Here, in the driving force increase control in the D range, the first
As shown in FIG. 5, the correction coefficient approaches 1 as the engine speed N increases from the lower limit value ko, so the slip amount of the forward clutch 61 due to lowering the line pressure is smaller when the engine speed N is lower. In some cases, the amount of slip is increased to promote the increase in the engine speed N, and as the engine speed N increases, the slip amount decreases, and the second
When the rotation speed increases to the set rotation speed N2, the control to slip the forward clutch 61 ends even before the predetermined time T has elapsed from the start of the starting operation, and the clutch 6
1 is in a fully engaged state. Therefore, the problem of causing the forward clutch 61 to slip unnecessarily even though the engine speed has sufficiently increased, thereby accelerating its wear, can be avoided.

Further, in this embodiment, even before the predetermined time T has elapsed from the start of the start operation, the throttle opening θ is the predetermined opening θ that is the limit value of the slip control. If larger, step ssg to step S6 of the flowchart
2 is executed, and the slip control as described above is stopped. This prevents wear caused by slipping the forward clutch 61 when a large torque is input to the forward clutch 61.

(Effects of the Invention) As described above, according to the start control device for a vehicle equipped with an automatic transmission according to the present invention, when controlling to temporarily increase the driving force at the time of starting, this control is performed only when starting forward. conduct,
Since this control is prohibited when starting in reverse, good starting acceleration performance can be obtained with a large driving force when starting forward, and when starting in reverse, the vehicle starts with a relatively small driving force that corresponds to the driver's accelerator operation. I will do it. This provides good maneuverability when reversing, which is more difficult to drive than when moving forward.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic configuration diagram of the present invention, and FIG.
The drawings show the first embodiment of the present invention, Fig. 2 is a control system diagram, Fig. 3 is a circuit diagram showing the configuration and arrangement of the brake pressure control valve and its actuator, and Fig. 4 is a shift lock device diagram. A partially cutaway front view of the shift lever showing the configuration;
Figure 5 is a flowchart showing the control operation of the control unit when starting, Figure 6 is an opening/closing characteristic diagram of the pressure reducing solenoid valve used in this control, and Figures 7 and 8 are the throttle delay time and brake release speed. FIG. 9 is a characteristic diagram showing the characteristics with respect to the opening degree, and a time chart showing the operation of this embodiment. 10 to 16 show a second embodiment of the present invention, FIG. 10 is a schematic diagram showing the structure of an automatic transmission according to this embodiment, and FIG. 1) shows a slip in the hydraulic control circuit. A circuit diagram showing the control part, Fig. 12 is a diagram of the operating characteristics of the duty solenoid valve, Fig. 13 is a control system diagram, Fig. 14 is a flowchart showing the control operation of the control unit when starting, Figs. 15 and 16. These are characteristic diagrams showing the characteristics of the correction coefficient used in this control with respect to the engine speed and the characteristics of the basic duty rate with respect to the throttle opening. 7.7'... Automatic transmission, 7a, 7a'... Torque converter, 7b, 7b'... Speed change gear mechanism, 25b
, 26b, 50, 75.80...Driving force increasing means (pressure reducing solenoid valve, shift lock device, duty solenoid valve, regulator valve>, 30.90...Driving force increase inhibiting means (control unit>, 33.92
...Start operation detection means (throttle opening sensor>, 3
5.94...Shift range detection means (shift range sensor). Figure 3... ・k↓ Figure 4 Fecal serum 4 and

Claims (1)

[Claims] (1) A start control device for a vehicle equipped with an automatic transmission that transmits engine output to drive wheels via a torque converter and a speed change gear mechanism, comprising a start operation detection means for detecting a start operation of the vehicle, and a start operation detection means for detecting a start operation of the vehicle; a driving force increasing means for temporarily increasing the driving force transmitted to the driving wheels when a starting operation is detected by the means; a shift range detecting means for detecting a shift range of the automatic transmission; and the detecting means. A start control means for a vehicle equipped with an automatic transmission, characterized in that a driving force increase inhibiting means for inhibiting driving force increasing control by the driving force increasing means when a shift to a reverse range is detected.