JPH01212647A - Device for controlling starting of vehicle equipped with automatic speed change gear - Google Patents

Abstract

PURPOSE:To let excellent accelerating properties in starting be enhanced in a heavy vehicle by actuating a braking device at the time of starting, and thereby concurrently controlling the device to be released either at the time of starting operations or after a specified delayed time has elapsed. CONSTITUTION:An automatic speed change gear A composed of a torque converter A1 and of a speed change gear mechanism A2 is constituted that plural numbers of gear shiftings can be obtained by switching the power transmitting route of the speed change gear mechanism A2. A valve equipped with such the automatic speed change gear mechanism as described above is provided with a braking means C actuating braking means B and B at the time of starting. In addition, a starting actuation detecting means D is provided, which detects starting operations such as the depression of an accelerating pedal and the like. And when the starting operations are detected, the braking devices B and B are controlled to be released by a brake releasing means E after a specified delayed time has elapsed since the time of the starting operations. By this constitution, powerful driving force can be obtained at the time of starting, thereby letting accelerating properties in starting be enhanced.

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 adjusting the transmission according to driving conditions. When the vehicle is started, the gear is automatically set to the gear with the largest reduction ratio, that is, the first gear.

In addition, 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 stress situations such as when starting, and this torque increase By this action and the deceleration action of the transmission gear mechanism, the required starting acceleration force is obtained at the time of starting.

By the way, regarding the torque increasing effect of this torque converter, there is a known one that controls the torque increase rate, that is, the torque ratio according to the operating condition, as described in, for example, Japanese Patent Laid-Open No. 130659/1983. There is. According to this, by increasing the torque ratio at the time of starting,
It is possible to improve the starting acceleration performance without deteriorating the power transmission efficiency or the fuel efficiency of the engine during normal driving, and for example, good starting performance can be obtained even in a heavy vehicle.

(Problem to be Solved by the Invention) However, when trying to variably control the torque ratio of a torque converter as described above, the stator that performs the torque increasing action in the torque converter is made movable, and the actuator that drives it and its A control device, etc. is required, which results in a significantly complicated structure and an increase in cost.Also, this variable torque ratio torque converter is only used for heavy vehicle models that do not have sufficient starting acceleration, for example. If an attempt is made to apply this, significant changes to the specifications will be required.

In addition, in order to improve the starting acceleration performance, it is possible to increase the reduction ratio of the first gear of the automatic transmission and the reduction ratio of the final reduction gear, but these measures do not improve the speed during normal driving. In addition to affecting the performance, this will also worsen fuel efficiency, and as in the case above, a significant change in specifications will be required, leading to an increase in costs.

SUMMARY OF THE INVENTION Therefore, the present invention provides an automatic transmission system for this type of automatic transmission that does not adversely affect the driving performance or fuel efficiency during normal driving, and without causing a significant change in specifications or a significant increase in costs associated with this. The purpose is to improve the starting acceleration performance of vehicles equipped with this.

(Means for Solving the Problems) In order to achieve the above object, a start control device for a vehicle equipped with an automatic transmission according to the present invention is characterized in that it is configured as follows.

That is, as shown in FIG. 1, an automatic transmission A is provided in which a torque converter A1 and a speed change gear mechanism A2 are combined, and a plurality of gears are obtained by switching the power transmission path of the speed change gear mechanism A2. In the vehicle equipped with the vehicle, a brake means C that operates the brake devices B and B when the vehicle starts, a start operation detection means that detects a start operation such as an accelerator pedal depression operation, and a start operation is detected by the detection means. A brake release means E is provided which releases the brakes B and B device after a predetermined time delay when detected.

Here, the brake means C may be one that automatically operates the brake devices B and B when starting, but for example, a shift lock device, that is, an automatic transmission unless the brake pedal is turned on when starting. It is also possible to use a device that prevents the shift lever from being shifted into the driving range. In addition, the brake release means E
may be configured such that when the brake devices B and B are released after a predetermined delay time has elapsed from the start of the start operation, the release speed is changed according to the amount or speed of depression of the accelerator pedal. .

(Function) According to the above configuration, when the vehicle starts, the brake devices B and B are activated by the brake means C, and in this state, a start operation is performed by depressing the accelerator pedal, etc.
At this time, due to the action of the brake release means E, the brake devices B are released after a predetermined delay time has elapsed from the start of the starting operation. Therefore, during the above delay time, only the engine speed increases while the vehicle is stopped, but at this time automatic transmission A is already in
Since the torque converter A1 in the automatic transmission A is shifted to a driving range such as a range, the torque converter A1 in the automatic transmission A is in a so-called stall state in which the output member is fixed and only the input member rotates, and the torque ratio is maximized. Then, as this torque ratio increases and the engine speed increases, a large driving force is transmitted from the automatic transmission A to the drive wheels F, F, and therefore, after the delay time elapses, the brake device B , B are released, the vehicle will start with a large starting acceleration force.

Note that when the brake devices B and B are released after the delay time has elapsed from the start of the start operation, if the release speed is controlled to be slower as the amount or speed of depression of the accelerator pedal is smaller, for example, When the amount of depression of the accelerator pedal is small, the stalled state of the torque converter is gradually released even though the engine output is small, thereby increasing the starting acceleration force and increasing the driving torque. The acceleration becomes relatively gentle, and it is prevented that the driver is given a feeling of acceleration greater than that achieved by operating the accelerator pedal. In addition, if the amount of depression of the accelerator pedal is large and the engine output is high to begin with, the stalled state of the torque converter is quickly released and a sudden start due to an unnecessarily large starting acceleration force is avoided. At the same time, the drive torque rises relatively quickly, giving the driver a sense of acceleration that matches the operation of the accelerator pedal.

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

As shown in FIG. 2, in the vehicle 1 according to this embodiment, the left and right front wheels 2.3 are driven wheels, and the left and right rear wheels 4.5 are driving wheels. The output of the engine 6 is transmitted via an automatic transmission 7, a propeller shaft 8, a differential gear 9, and left and right drive shafts 10 and 11.

Further, the left and right front wheels 2.3 and the left and right rear wheels 4.5 have disc rotors 12a to 12a rotating integrally therewith.
15a, and calipers 12b to 12b that brake the rotation of the disc rotors 12a to 15a when brake pressure is supplied.
Brake device 12.13.14.15 consisting of 15b etc.
are provided, and when the brake pedal 16 is depressed, the brake pressure generated in the mask cylinder 17 is transmitted to each of the brake devices 12 to 15 through the brake system 20.
Here, the brake system 20 includes a first system 21 connected to the first discharge hole 17a of the mask cylinder 17, and a second system connected to the second discharge hole 17b. 22, and the first system 21 is connected to the brake device 12 for the left front wheel 2 and the brake device 15 for the right rear wheel 5,
Further, the second system 22 is led to the brake device 13 for the right front wheel 3 and the brake device 14 for the left rear wheel 4, respectively. A branch line 22a leading to the left rear wheel brake device 14 of the second system 22 and a branch line 21a leading to the right rear wheel brake device 15 of the first system 21 are connected to these brake devices 14.15. Brake pressure control valves 23, 24 for controlling the supply of brake pressure are installed, and actuators 25, 26 are provided for operating these control valves 23, 24, respectively.

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
The shift lever 34 in the automatic transmission 7 receives a signal a from the vehicle speed sensor 31 that detects the vehicle speed and a 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. A signal C from the shift position sensor 35 that detects the position (range) of
A signal d from the brake sensor 36 that detects the depression operation of the brake pedal 16, and a signal e from the brake pressure sensor 37 that detects the hydraulic pressure downstream of the brake pressure control valve 23 (and 24) in the brake system 20. , and a signal f from an inclination sensor 38 that detects the degree of inclination of the vehicle 1. Based on these signals a to f, the control unit 30 controls the automatic transmission 7 to control the speed change of the automatic transmission 7.
It outputs a shift control signal g to the actuator 25, 26 of the brake pressure control valve 23, 24 to perform brake control at the time of starting, and outputs a brake control signal h to the actuator 25, 26 of the brake pressure control valve 23, 24, and also outputs a shift lock signal h, which will be described later. A lock release signal i (see FIG. 4) is output to the device 5o.

Here, to briefly explain the speed change control operation of the control unit 3o, the control unit 30 compares the vehicle speed and engine throttle opening indicated by the signals a and b with a preset speed change map, and controls the current driving speed. A gear position is determined according to the state, and the sudden shift control signal g is outputted so that the gear position is selected.

Next, the configuration of the brake pressure control valve 23.24 and its actuator 25.26 will be explained with reference to FIG.
The brake pressure control valves 23, 24 according to this embodiment are capable of increasing, decreasing, and maintaining the brake pressure supplied to the brake devices 14, 15 for the left rear wheel and the right rear wheel. The pistons 23b, 24b are inserted into the cylinders 23a, 24b to define the insides of the cylinders 23a, 24b into variable volume chambers 23c, 24c and control chambers 23d, 24d, and the pistons 23b, 24b are fitted with a spring 23e.
, 24e, the variable volume chambers 23c, 24c are biased in a direction to increase their volumes. A second cylinder extends from the mask cylinder 17 to the left rear wheel brake device 14. The branch line 22a of the system 22 and the branch line 21a of the first system 21 leading to the brake device 15 for the right rear wheel pass through the variable volume chambers 23c and 24c, respectively, and normally the brake pressure generated in the mask cylinder 17 is transferred to these. The water is supplied to the left and right rear wheel brake devices 14 and 15 through the variable volume chambers 23c and 24c. Further, the pistons 23b and 24b include a control chamber 23d,
The control pressure introduced into the pistons 23b and 24d
4b resists the springs 23e and 24e to open the variable volume chamber 2.
Check valves 23f and 24f are provided to close the brake pressure inlets to the variable volume chambers 23c and 24c when the volumes of the variable volume chambers 3c and 24c move in a direction to decrease.

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 25a and 26a and pressure reducing solenoid valves 25b and 26b. 25b and 26b are duty solenoid valves that are periodically controlled to turn on and off at a predetermined on and off ratio (duty rate). In addition, the pressure increasing solenoid valves 25a, 26
a is connected to the control chambers 23d, 24d of the brake pressure control valves 23.24 from the oil pump 40 via the relief valve 41;
The pressure reducing solenoid valves 25b and 26b are arranged on the control pressure supply lines 42 and 43 leading to the control chamber 2, respectively.
They are placed on drain lines 44 and 45 led from 3d and 24d, respectively. And these solenoid valves 25
a, 26a, 25b, and 26b are opened and closed by the brake control signal h from the control unit 30, and when the pressure increase solenoid valves 25a and 26a are opened and the pressure reduction solenoid valves 25b and 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 moved by the spring 23e.
, 24e in a direction in which the volume of the variable volume chambers 23c, 24c decreases, the brake device 1
The brake pressure supplied to 4.15 will be increased, and in this state, the pressure increasing solenoid valve 25a.

When 26a is closed, the brake pressure supplied to the brake device 14, 15 is maintained. Further, when the pressure increase solenoid valves 25a and 26a are shut off and the pressure reduction solenoid valves 25b and 26b are opened, the control chamber 23d
, 24d, the brake pressure supplied to the brake devices 14 and 15 is also reduced, but at this time, the pressure reducing solenoid valves 25b,
Since the brake valve 26b is constituted by a duty solenoid valve as described above, the brake pressure maintenance and pressure reduction operation are performed by duty control of the pressure reduction solenoid valves 25b and 26b.

In this embodiment, the automatic transmission 7 is equipped with a shift lock device 50. 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 for parking) is provided in the daytent plate 51 that regulates the position of 4.
In addition, the shift lever 34 is provided with a lock pin 52 that can be engaged with and detached from the groove 51a, and a solenoid 53 that operates the lock pin 52.

When the brake pedal 16 is depressed, a lock release signal i is input from the control unit 30 to the solenoid 53 to disengage the lock pin 52 from the detent groove 51a, thereby shifting the shift lever 34 to the driving range. Shift operations are now possible.

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, when the vehicle is stopped, the control unit 30 activates the shift position sensor 35 in step S1.
The shift position of the automatic transmission 7 is determined based on the signal C from the brake sensor 36, and when the shift position of 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 determines whether the brake pedal 16 is depressed in step S2. Determine whether or not.

If the brake pedal 16 is not depressed, the shift lock device 50 shown in FIG.
This disables the operation of the shift lever 34 to the driving range, and when the pedal 16 is depressed, step S
At step 4, a lock release signal i is output to the solenoid 53 of the device 50, allowing the shift lever 34 to be operated into the travel range.

Next, the control unit 30 determines the shift position of the automatic transmission 7 again based on the signal C from the shift position sensor 35 in step S5, and further determines the shift position of the automatic transmission 7 from the tilt sensor 38 in step S6 when the shift operation is performed to the D range. The slope of the vehicle is determined based on the signal f, and if this is less than a predetermined value α, in other words, if the road surface is approximately flat,
Next, in step S, the vehicle speed of the vehicle is determined based on the signal λ from the vehicle speed sensor 31. When the vehicle speed is less than a relatively small predetermined value Vo, that is, when the vehicle is stopped or at a very low speed before the starting operation is completed,
Furthermore, in step S8, the current detected value θ of the throttle opening indicated by the signal from the throttle opening sensor 33 is compared with the previous detected value θ', and when the two are equal, that is, the start operation by pressing the accelerator pedal is If not, the signal e from the brake pressure sensor 37 is output in step S9.
After confirming that brake pressure is being supplied to the rear wheel brake device 14 (and 15),
The brake control flag F is set to 1 according to S1G and Stt, and the pressure reducing solenoid valves 25b and 2 shown in FIG.
The duty ratio of the brake control signals h' and h' that control the brake control signals 6b and 6b is set to 100%. Then, step S12
At this duty rate, the pressure reducing solenoid valves 25b and 26b
The control signals h' and h' are outputted so as to operate the control signals h' and h'. Here, the pressure reducing solenoid valves 25b and 26b are the sixth
As shown in the figure, when the duty rate is 100%, the fully closed state is reached, and at this time, the control pressure is trapped in the control chambers 23d and 24d of the brake pressure control valves 23, 24, and the rear wheel brake device 14 is closed. .15 will be maintained in a state where brake pressure is supplied, that is, in a state where these brake devices 14 and 15 are activated.

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', so the control unit 30 executes steps StS from step S8 above. After confirming that the brake control flag F is 1, it is determined in step S14 whether or not the current detected value θ of the throttle opening becomes larger than the previously detected value θ', that is, the moment when the starting operation is started. Determine. In this case, since this is the moment when the starting operation is started, the control unit 30 determines in step 815 the delay time T from the start of the starting operation to the start of the brake release operation, and the release speed ΔD (1 control (amount of decrease in duty rate with respect to period). In that case, the above delay time T
and release speed ΔD is a function value f(θ) of throttle opening θ
1g(θ), 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 release speed ΔD is set as shown in FIG. 8. , the opening θ in a predetermined throttle opening range θ2 to θ3.
It is set to become larger (faster) as the value increases.

Then, the control unit 30 next performs step S.
In step S16, it is determined whether the set time (delay time) T is O or not, and since the time T is not 0 immediately after starting the start operation, 1 is further subtracted from the time T in step S17. By executing steps S11*S12, the duty rate is set to 100%, that is, the brake device 1
4. Keep the 15 activated. This state is the step Sl? Until the time T becomes 0 by the subtraction process of the set time T, in other words, from the start of the start operation to the delay time set according to the throttle opening θ, the vehicle speed increases even though the rotational speed increases. At the same time, in the automatic transmission 7, the torque converter 7a shown in FIG. It will be transmitted.

When the set time T elapses in this state, the control unit 30 executes steps S16 to SIg and determines whether the duty rate is 0 or not. is 100%
Therefore, the control unit 30 then performs step S.
19, and from this duty ratio, perform step S
The reduction amount (brake release speed) ΔD set in step S15 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 S12.
, h'. And this step S 19+
By repeatedly executing step 312, the duty rate is gradually reduced.

26b gradually approaches the fully open state, the control pressure in the control chambers 23d, 24d of the brake pressure control valve 23.24 is gradually discharged, and the brake device 14.1
The brake pressure supplied to 5 is gradually reduced, and in this way the brake device 14, 15 is released.

This causes the vehicle to start, but in that case, the engine speed is already high as described above, and the torque converter 7a is in a stalled state, so the torque ratio is high. Therefore, the vehicle starts with a large driving force, and good starting acceleration performance is obtained. Here, control unit 3
0 is the predetermined vehicle speed V when the duty rate becomes 0 due to the duty rate subtraction process in step S19, or when the vehicle starts moving. When the brake control flag F is exceeded, steps sao and sat are executed to reset the brake control flag F to 0 and clear the duty ratio to 0.

As mentioned above, the delay time T from the start of the start operation to the start of the brake release operation becomes shorter as the throttle opening θ becomes larger, and the release speed at the time of brake release (ΔD
) is made faster as the throttle opening θ becomes larger, so 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, causing the accelerator pedal to The starting acceleration force corresponding to the operation of the engine can be obtained, and when the engine output is increased at a high throttle opening, the stall condition of the torque converter is released relatively early, and the release speed is also faster. This avoids unnecessarily prolonging the stall state. In this way,
The optimum starting condition can always be obtained depending on the throttle opening θ, that is, the amount of depression of the accelerator pedal at the time of starting, but variable control of this delay time T and brake release speed ΔD depends on the depression speed of the accelerator pedal or the amount of depression of the accelerator pedal. Depending on the increasing speed of the throttle opening, the delay time T may be shortened and the brake release speed ΔD may be increased as these speeds increase.

(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, the brake device is actuated at the time of start, and the brake device is operated after a predetermined delay time has elapsed from the start of the start operation. Since the engine speed increases during this delay time, the torque converter in the automatic transmission enters a stall state and the torque ratio increases, so the brake device is released. This means that a large driving force can be obtained when the vehicle starts moving. As a result, for example, good starting acceleration performance can be obtained even in heavy vehicle models, and in particular, according to the present invention, significant specification changes such as changes in the torque converter, transmission gear mechanism, or final reduction gear, etc. There is an advantage in that starting performance can be improved without causing any adverse effects on driving performance during normal driving or deterioration of fuel efficiency.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is an overall schematic configuration diagram of the present invention, and FIG.
The figures show an embodiment of the present invention; Fig. 2 is a control system diagram, Fig. 3 is a circuit diagram showing the structure and arrangement of the brake pressure control valve and its actuator, and Fig. 4 is the structure of the shift lock device. A partially cutaway front view of the shift lever showing the
Fig. 5 is a flowchart showing the control operation of the control unit when starting, Fig. 6 is an opening/closing characteristic diagram of the pressure reducing solenoid valve used in this control, and Fig. 7.8 is 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. 7... automatic transmission, 7a... l/lux converter,
7b... Speed change gear mechanism, 14.15.50... Brake means (brake device, shift lock device), 25b
, 26b, 30...brake release means (pressure reducing electromagnetic valve, control unit), 33...start operation detection means (throttle opening sensor).

Claims (2)

[Claims] (1) Combining a torque converter and a speed change gear mechanism,
A start control device for a vehicle equipped with an automatic transmission that obtains a plurality of gears by switching the power transmission path of the speed change gear mechanism, the device comprising a brake means for operating a brake when the vehicle starts, and a start operation. A vehicle equipped with an automatic transmission, comprising a starting operation detecting means for detecting a starting operation, and a brake releasing means for releasing the braking means after a predetermined time delay when a starting operation is detected by the detecting means. Launch control device. (2) The brake release means changes the brake release speed according to the amount or speed of depression of the accelerator pedal when a predetermined delay time has elapsed from the start of the start operation. Start control device for vehicles equipped with automatic transmission.