JPH10181387A - Shift control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax the occurrence of a shift shock and to shorten a shift time by a method wherein when a vehicle is changed over to a low speed stage, it is decided whether a vehicle before and after a shift is in a driving state or a driven state, and based on the deciding result, a prime mover output is decreased. SOLUTION: For example, when a vehicle is running on a downward slope, the rotation speeds of an input shaft and an output shaft are measured by the rotation speed sensor of an automatic transmission, and it is computed whether an automatic engine brake is needed. When the brake is needed, a shift signal by which a down shift is executed is outputted at a step 1. Torque of a drive shaft connected to the output shaft of the automatic transmission and the opening of an electronic throttle detected by a throttle position sensor are then measured to analyze the drive state or the driven state of a vehicle available during receipt of a shift signal and drive and driven of the vehicle after a shift are also predicted at a step 2. Operation to close an electronic throttle to a fixed opening by an actuator is then performed at a step 3. It is then decided at a step 9 whether a timing time t1 elapses. After a lapse of the t1, down shift control is executed at a step 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission, and more particularly to a shift control for performing a downshift.

[0002]

2. Description of the Related Art Conventionally, there has been known a shift control device of an automatic transmission which reduces a shift shock while reducing a shift time by an engine output increase control without causing acceleration of a vehicle at the time of a downshift in an accelerator OFF state. I have. For example, Japanese Patent Application Laid-Open No. Hei 5-3 filed with Toyota Motor Corporation
Japanese Patent Publication No. 02532 discloses a shift control device that performs timing control for increasing the engine output so that the engine output increases while the friction engagement device of the automatic transmission is slipping.

FIG. 6 is a main configuration diagram of a shift control device for an automatic transmission. In the figure, the shift control device includes an engine control computer 32, a transmission control computer 34, and a throttle control computer 35, all of which incorporate a CPU, a RAM, a ROM, an input / output interface circuit, an A / D converter, and the like. Yes, RA
Signal processing is performed according to a program stored in the ROM in advance while utilizing the temporary storage function of M. When automatically shifting down to increase the engine braking force in the accelerator OFF state by these computers, the timing for temporarily opening the throttle valve and increasing the engine output is set to a desired time, and the low speed stage side is set. While preventing the service life of the friction engagement device from being shortened, the engine rotation speed is increased to reduce the shift time required for downshifting, and the friction engagement device on the low speed side, such as the hydraulic clutch or brake, transmits torque to the output side. The inertia torque due to the transmission of the torque to the engine side was prevented from appearing as a braking torque of the vehicle, and a large shift shock was mitigated.

[0004]

However, the shift control of the automatic transmission is effective for downshifting when the accelerator is turned off when the vehicle is driven, but the actual accelerator operation depends not only on the vehicle speed but also on the road. Since it changes according to the gradient, road surface conditions (coefficient of friction), wind speed, etc., engine braking may be required even when the throttle is not fully closed. That is, when downshifting is performed in a state where there is almost no driving force from the engine and the current engine rotation speed is maintained, for example, in a state where the engine rotation speed is maintained equal to or higher than the idle rotation speed, the automatic transmission In the shift control, when the vehicle transitions from the driving state to the driven state, for example, the shock across the backlash when the area of contact with the differential gear changes, or the shift time required for downshifting can be reduced. There was a disadvantage that there was no. Therefore, even when the throttle is in the substantially OFF state and other states, if the shift control of the automatic transmission is performed by determining whether the vehicle is in the driven state or the driven state, the shift shock during the downshift is reduced. In addition, it is expected that the shift time is shortened.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. A first object of the present invention is to detect the driving and driven states of a vehicle, reduce the output of a prime mover, and then reduce the output when a predetermined time has elapsed. The shift control has been executed. It is a second object of the present invention to execute downshift control after detecting that the vehicle has been driven before shifting.

[0006]

In order to achieve the first object, a structural feature of the first invention is that when an automatic transmission is downshifted to a low gear to produce a braking action, the automatic transmission is released. The rotational speed of the prime mover is changed after the slippage of the high-speed side frictional engagement device to be started starts until the low-speed side frictional engagement device engaged during the downshift is completely engaged. A downshift control device that temporarily raises the vehicle, a timing control device that starts the downshift control device after a lapse of a predetermined time from a predetermined start time, and a driving state of the vehicle when the automatic transmission is switched to a low gear. And a drive state analyzer that determines whether the vehicle before or after the shift is in a driven state or a driven state, and based on the determination result of the drive state analyzer, reduces the output of the prime mover to drive the vehicle before the shift. A prime mover output control device for the driven state from the state, after starting the engine output control device, in order to temporarily increase the rotational speed of the prime mover in providing the timing control device for activating the down-shifting control device.

In one embodiment of the present invention, the low-speed gear switching of the automatic transmission is not limited to a shift control device that automatically downshifts according to a shift map, and a driver turns off an overdrive switch on a downhill or the like. The driver may manually perform a downshift to increase the engine brake, such as switching the shift lever from the D range to the S range or the L range, and may temporarily stop the engine to reduce the shift time. The present invention can be applied to a speed change control device that is raised to Further, the drive state analysis device may be a transmission control computer that measures the throttle opening and the output shaft torque of the automatic transmission to determine the drive or driven state before and after the shift. Further, the motor output control device includes a throttle control computer for turning off the electronic throttle substantially, and a means for reducing the output of the motor, such as turning off the power of the ignition plug, closing the intake bypass valve, An engine control computer that turns off the injection device may be used. The prime mover may be a gasoline or diesel engine, or may be an electric motor or a hybrid engine combining an electric motor and an engine as long as the means increases or decreases the output of the prime mover.

According to a second aspect of the present invention, in order to achieve the second object, in the first aspect, the timing control device downshifts after detecting that the vehicle has been driven before shifting. Activating the control device.

In one embodiment of the present invention, a computer for comparing the internal turbine rotation speed or output shaft torque of the automatic transmission with the prime mover rotation speed in order to detect that the vehicle has been driven before shifting. Can be used.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A shift control device for an automatic transmission according to an embodiment of the present invention will be described below with reference to the drawings. This shift control device is configured for a vehicle having a prime mover as a gasoline engine.

The flowchart of FIG. 1 relates to control of a shift control device for an automatic transmission according to an embodiment of the first invention for achieving the first object. Less than,
A shift control device for an automatic transmission, which is a control target of the present invention, will be described with reference to the conventional device shown in FIG. After turning the electronic throttle 20 off, the electronic throttle 20 is temporarily opened to determine whether or not to increase the engine output.
In the case of s, that is, when it is determined that the vehicle before the shift is in the driving state and the vehicle after the shift is in the driven state. In the figure, when the conditions of Steps 1 to 3 and Step 9 are all satisfied and the automatic engine braking is executed, the electronic throttle 20 is temporarily turned off, the output of the engine 10 is reduced, and the vehicle is driven. Then, after detecting that the timing time t1 counted by the timer has elapsed, a gradual downshift control 8 is performed.
Is executed, and when the condition of step 2 is not satisfied, in step 4, the normal downshift control 5 is executed. That is, this is a case where it is determined that both the vehicles before and after the shift are in the driven state. Therefore, the control from step 1 onward, which does not satisfy any of these conditions, executes the normal shift control without performing the automatic engine brake control.

In step 1, for example, when the vehicle is traveling on a downhill, the rotational speed sensor 8 of the automatic transmission 78
From 0 and 82, the rotation speed of the input shaft and the output shaft and the engine 1
The rotation speed of 0 is measured, and whether or not automatic engine braking is required is calculated. If the result of this calculation is that automatic engine braking is required, a shift signal for executing a downshift is issued and step 2 and subsequent steps are performed. To determine whether to perform gradual downshift control. Further, the current gear position is changed to the transmission control computer 34.
For example, if the overdrive switch 74 is turned OFF while the vehicle is traveling at the current O / D shift speed, the engine brake is increased by switching the shift lever from the D range to the S range or the L range. Similarly, when the driver performs a downshift by manual operation, a shift signal for executing the downshift is issued, and the process branches to step S2.

In step 2, the torque To of the drive shaft connected to the output shaft of the automatic transmission 78 and the opening degree TA of the electronic throttle 20 detected by the throttle position sensor 36 are measured to receive the shift signal in step 1. Of the driving state analyzing apparatus which analyzes the driving or driven state of the vehicle and predicts the driving or driven state of the vehicle after the shift, and determines whether or not to perform gentle downshift control in step 3 and subsequent steps. Is shown. The following Table 1 shows a drive driven determination map in which the throttle opening TA and the drive shaft torque To are input data when downshifting from the fifth gear to the fourth gear. In the table, the throttle opening TA
Is 0 (zero), the drive shaft torque To is 10
If the measured value is 0 or more (this value is a relative value of 1 / X of the actually measured value; the same applies hereinafter), it is determined that the vehicle is traveling in a driving state, and the drive shaft torque To is less than 100. If so, it is determined that the vehicle is running in a driven state. Further, as the throttle opening increases, the drive shaft torque is determined in descending order corresponding to the order of SS (minimum), S (small), M (medium) and L (large).

[0014]

[Table 1] The driving state analysis device detects a torque T of a predetermined rotating portion at a predetermined throttle opening TA, and converts the detected torque T to a predetermined throttle opening TA stored in a shift control computer in advance. , The driving or driven state of the vehicle after the shift can be analyzed. That is, as shown in the following Table 2, if the detected torque T at the predetermined throttle opening TA is equal to or less than zero, the vehicle before and after the shift is both driven, the torque T is greater than zero, and equal to or less than the reference torque data TX. In this case, it is determined that the current vehicle before the shift is in the driving state, and that after the shift, the vehicle shifts to the driven state. Further, when the torque T is larger than the reference torque data TX,
It is determined that the vehicles before and after the shift are both running in the driving state.

[0015]

[Table 2] The torque T is not limited to the drive shaft torque To. Any other torque can be used as long as the driving state of the vehicle such as the rotational speed NO of the engine 10 and the turbine torque in the automatic transmission 78 can be detected. Torque can be used. Therefore, in order to analyze the driving state of the vehicle before and after shifting, instead of measuring the drive shaft torque and the opening degree TA of the electronic throttle 20, the rotation speed NO of the output shaft of the engine 10 and the accelerator operation amount sensor 76 The driving state of the vehicle can be analyzed and determined from the output by using the opening degree of the accelerator pedal as a variable. Table 3 shows the MK that uses the engine rotation speed NO and the accelerator pedal opening KTA1 obtained from the output of the accelerator operation amount sensor 76 as input data.
The TA1 map interpolation value is shown. In the table, the engine rotation speed NO is MIN (minimum value), S (small), M (medium), L
(Large) and MAX (Maximum), and the accelerator pedal opening corresponding to this is set in the range of 10% to 40%. That is, the engine speed NO is M (medium)
If the accelerator pedal opening KTA1 is 15% or more at the time of the driving, the driving state analysis device determines that the vehicle is running in a driving state, and if the KTA1 is less than 15%, the vehicle is also in the driven state. It is determined that the vehicle is running.

[0016]

[Table 3] Based on the data measured in this way, the driving state analysis device can determine that the vehicle before the shift is in the driving state and is in the driven state after the shift, and the process branches to step 3 and subsequent steps. The drive state analysis can be performed by any of the illustrated engine control computer 32, transmission control computer 34, and throttle control computer 35.

In step 3, an operation is performed to close the electronic throttle 20 to a predetermined opening using an actuator.
For example, the transmission control computer 34
Indicates a pattern signal SP representing the selected pattern from the pattern select switch 70, a brake signal SB representing that the brake has been depressed from the brake lamp switch 72, and O representing the permission of shifting from the overdrive switch 74 to the O / D gear. / D signal SO and accelerator operation amount signal SAc indicating accelerator operation amount Ac from accelerator operation amount sensor 76, respectively. The accelerator operation amount signal SAc is supplied to the engine control computer 32 and the throttle control computer 35, and the accelerator operation amount signal SAc becomes data for determining the driving or driven state of the vehicle. Based on this data, for example, when the driving state analysis device analyzes that the vehicle is in a driving state before the shift and the vehicle after the shift is in a driven state, the prime mover output control device uses the output DTH of the throttle control computer 35 to output an electronic signal. The throttle 20 is closed through an actuator to perform control for reducing the output of the prime mover. The pattern select switch 70 is provided with an automatic engine brake pattern for automatically increasing the engine brake when the vehicle goes downhill or the like. A driver's favorite traveling pattern can be selected and operated from a plurality of predetermined traveling patterns, such as an economy pattern in which gear shifting is performed according to the emphasized shift map.

The automatic engine braking pattern is for downshifting the automatic transmission 78 to a low gear, and the time elapsed from a predetermined measurement start time at the time of downshifting in order to cause the effect of engine braking. Based on the elapsed time measured by the timer and the elapsed time measured by the timer, the frictional engagement device on the high speed stage to be released at the time of the downshift starts to slip and then engage at the time of the downshift. When a predetermined timing time based on the measurement start time elapses so that the engine rotation speed increases until the friction engagement device on the low speed side is completely engaged, the engine output increasing means It includes a program for operating the timing control means for increasing the engine output.

The shift control of the automatic engine brake pattern of the automatic transmission 78 is performed when the vehicle drive state analyzing apparatus determines that the vehicle before the shift is in a driven state and the vehicle after the shift is in a driven state is an idling rotation. The engine control computer 32 determines the current opening of the electronic throttle 20 that maintains the rotation speed slightly higher than the speed, and instructs the throttle control computer 35 to further close the opening of the current electronic throttle 20. The electronic throttle control computer 35 can issue a DTH signal to fully close the electronic throttle 20 by an actuator. By this operation, the vehicle can be shifted from the driving state to the driven state. The electronic throttle 20 is fully closed even when the intake passage 18 is completely closed and air is supplied only from the bypass passage 22 side. May be supplied with air. Thereafter, the process branches to step 9 for determining whether to perform downshift control for increasing the engine braking force.

In step 9, it is determined whether or not the timing time t1 has elapsed.
Is performed so as to perform the downshift control.
With this configuration, the shift control device can achieve a more rapid downshift. Engine 10
In the high-speed rotation region, a slight crossing shock occurs, but in the other low-speed regions, the shock due to the backlash can be effectively prevented.

In step 8, the electronic throttle 20 is temporarily opened to increase the output of the engine 10 to reduce the inertia phase shock. That is, the downshift control device counts and detects the timing at which the electronic throttle 20 is temporarily opened and the engine output is increased by the timing control device, and prevents the life of the friction engagement device on the low-speed stage side from being shortened while preventing the engine from shortening. By increasing the rotation speed and shortening the shift time required for downshifting, the torque on the output side is transmitted to the engine side by the torque transmission of a friction engagement device on the low speed side, for example, a hydraulic clutch or a brake,
It is possible to prevent a large shift shock in which the inertia torque at this time appears as a braking torque of the vehicle.

If the condition of step 2 is not satisfied, it is determined in step 4 whether or not normal downshift control is to be performed. That is, if both the vehicle before and after the shift are in the driven state, normal downshift control can be performed in step S5. In addition, the normal downshift control is not performed. For example, the shift control device does not perform any control if the vehicle before and after the shift is both in a driving state, and the automatic transmission 78
Can perform a shift operation in a driving state.

In the above embodiment, the downshift control in step 8 is executed immediately after the elapse of the timing time t1 in step 9, but the second shift to achieve the second object shown in FIG. As in the second embodiment, step 7 for determining whether the output shaft torque of the automatic transmission 78 has shifted from positive to negative can be added. The step 6 and subsequent steps in the figure are for determining whether or not the electronic throttle 20 is to be temporarily opened to increase the engine output after the timing time t1 has elapsed before the gear position of the automatic transmission 78 is switched. Step 7 is executed when Yes is determined, that is, when it is determined that the output shaft torque of the automatic transmission 78 shifts from positive to negative and the vehicle before shifting is in a driven state. In the figure, when the conditions of steps 1 to 3 and steps 6 and 7 are all satisfied and the automatic engine braking is executed,
Once the electronic throttle 20 is turned off, the engine 10
, The vehicle is driven, and the timing time t1 counted by the timer elapses, and
After detecting that the output shaft torque of the automatic transmission 78 is negative, the gentle downshift control 8 can be executed.

In step 6, it is possible to determine whether or not a predetermined time t1 counted by the timer has elapsed from when the shift signal is received in step 1 described above as a start time. That is, in step 3, the output of the engine 10 is not increased until the timing time t1 has elapsed while the electronic throttle 20 is closed at the predetermined amount, and it is possible to wait for the vehicle to cross the play in the driven state.

In step 7, it is determined whether or not the output shaft torque of the automatic transmission 78 has shifted from positive to negative. That is, when the rotational speed NO of the engine 10 and the output shaft speed of the automatic transmission 78 are both low, the electronic throttle 20 is forcibly closed at the lapse of the timing time t1, so that the output shaft torque of the automatic transmission 78 is Has shifted to the negative state of the driven state. However, when the opening of the electronic throttle 20 is large, both the rotation speed NO of the engine 10 and the output shaft speed of the automatic transmission 78 are high, and the output shaft torque of the automatic transmission 78 does not exceed the timing time t1. In some cases, it has not yet shifted from positive to negative. In particular, when the accelerator 10 is slightly released while the engine 10 is rotating at a high speed, the vehicle runs in a driving state even after the programmed timing time t1 has elapsed, and the shock when crossing backlash is large.
Therefore, when performing smoother automatic engine braking in all the low, middle, and high speed regions, the timing control device monitors the output shaft torque of the automatic transmission 78 and determines whether the torque has shifted from positive to negative. It is possible to activate the downshift control device.

The control time chart shown in FIG.
According to the embodiment of the present invention, a curve 95 indicating the turbine rotation speed when the output shaft torque of the automatic transmission 78 does not shift from positive to negative by the elapse of the timing time t1, and a curve indicating the output shaft torque of the automatic transmission 97 and electronic throttle 2
The relationship of the curve 99 showing the opening degree of 0 is shown. In one embodiment, the turbine rotation speed can be represented by the rotation speed of a friction material of a friction engagement device provided in the automatic transmission 78. In the figure, a curve 95 indicating the turbine rotational speed of the downshift control of the present invention, which is indicated by a solid line, is zero when the shift signal output is issued, and the timing time t1
It keeps zero until the inertia phase is reached even after elapse. Thereafter, in the inertia phase, the frictional engagement device on the low speed side is completely engaged. As shown in the figure, at the start of the inertia phase at which the curve 95 indicating the turbine rotation speed increases, the curve 97 indicating the output shaft torque of the automatic transmission is still positive, and is negative by the hydraulic control inside the automatic transmission 78. Is forcibly shifted to. Therefore, even if the electronic throttle 20 is operated and temporarily released as indicated by a curve 99 indicating the electronic throttle opening, a shift shock occurs. The shift shock can be reduced as compared with the release control of the electronic throttle 20 described above. In addition,
In the above-mentioned embodiment, the timing time t1 is set by counting with a timer from the time of output of the shift signal. However, the present invention is not limited to this. Transmission 7
The timer may be counted from the point in time when the output shaft torque curve 97 of FIG. 8 shifts from positive to negative, or may be counted from the point in time when the output shaft torque curve passes a predetermined positive value.

FIG. 4 is a time chart according to the second embodiment of the present invention.
0, a curve 92 representing the output shaft torque of the automatic transmission and a curve 94 representing the opening of the electronic throttle 20. In the embodiment, similarly to the first invention, the turbine rotation speed can be represented by the rotation speed of the friction material of the friction engagement device provided in the automatic transmission 78. In the figure, the timing control device can activate the downshift control device when it detects that the output shaft torque of the automatic transmission 78 has shifted from positive to negative after the timing time t1 has elapsed. A curve 90 indicating the turbine rotational speed of the downshift control of the present invention shown by a solid line is zero when the shift signal output is issued, and maintains zero until the inertia phase is reached even after the lapse of the timing time t1. ing. Thereafter, in the inertia phase, the frictional engagement device on the low-speed gear side is completely engaged, and the shift is completed. As shown in the figure, at the start of the inertia phase in which the curve 90 indicating the turbine rotational speed rises, the curve 92 indicating the output shaft torque of the automatic transmission changes from positive to negative as shown by the solid line, and the automatic transmission 78
The shift to the negative shift pattern is further forcibly performed by the internal hydraulic pressure control. Therefore, the shock caused by the backlash during the shift control is extremely small, and the electronic throttle 20 is operated to temporarily release the electronic throttle 20 as shown by the curve 94, so that the shift shock at the start of the inertia phase can be extremely reduced. . On the other hand, a normal electronic throttle 2 not forcibly closing the electronic throttle 20 indicated by a broken line is used.
In the release control of 0, the output shaft torque of the automatic transmission is forcibly shifted from the positive to the negative shift pattern in a short time by the hydraulic control in the automatic transmission 78, so that the shift shock becomes extremely large.

FIG. 5 shows a hysteresis characteristic of the accelerator opening. In the figure, when the accelerator pedal opening KTA 1% increases, the driving and driven states of the vehicle are determined by increasing the map value in Table 3 by 2.0%, and conversely, the accelerator pedal opening KTA 1% decreases. In this case, the driving or driven state can be determined according to the map values in Table 3. In the shift control having hysteresis as described above, frequent downshifts can be prevented and smooth shift control can be achieved.

Although the shift control device of the automatic transmission in which the embodiment of the present invention is applied to a gasoline engine-driven vehicle has been described above, the present invention relates to a diesel engine vehicle other than the gasoline engine-driven vehicle as described above. Needless to say, the present invention can be applied to shift control for electric vehicles and hybrid vehicles.

In the above embodiment, the shift control for downshifting from the fifth speed range to the fourth speed range has been described. However, the present invention is not limited to the above-described specific range switching, but may be applied to each shift speed. A drive driven determination map can be set for each gear, or a drive driven determination map common to all shift speeds can be set. It should be noted that the map interpolation value (%) of the engine speed and the accelerator pedal opening may be provided for each gear stage, or may be commonly used.

Furthermore, in the above-described embodiment, the downshift control device is started by the timing control device after the motor output control device is started, but the present invention is based on various knowledge based on the knowledge of those skilled in the art. Modifications and improvements can be made, and the related art is disclosed below.

When the automatic transmission is downshifted to a lower gear in order to generate a braking action, the frictional engagement device on the higher gear to be released begins to slip, and then the low speed engaged during the downshift begins. A downshift control device for temporarily increasing the rotation speed of the prime mover until the gear on the side of the gear is completely engaged; and a driving state of the vehicle when the automatic transmission is switched to a low gear. A driving state analysis device that determines whether the vehicle before shifting is in a driving state and the vehicle after shifting in a driving state is in a driven state, and based on the determination result of the driving state analysis device, A motor output control device for reducing an output to change a vehicle before a shift from a driving state to a driven state, and the downshift control device for temporarily increasing the rotation speed of the motor after starting the motor output control device. Shift control device for an automatic transmission, characterized by comprising a timing control system for starting the.

The shift control device for an automatic transmission configured as described above can start the downshift control device immediately after the start-up of the motor output control device, thereby enabling quick shift control.

When the automatic transmission is downshifted to a lower gear in order to produce a braking action, the frictional engagement device on the higher gear to be released begins to slip, and then the lower gear engaged during the downshift begins. A downshift control step for temporarily increasing the rotation speed of the prime mover until the gear-side frictional engagement device is completely engaged; and a driving state of the vehicle when the automatic transmission is switched to a lower gear. A driving state analysis step of determining whether the vehicle before shifting is in a driving state and the vehicle after shifting in a driving state is in a driven state, and based on a determination result of the driving state analysis device, A motor output control step of reducing the output to change the vehicle before the shift from a driving state to a driven state, and, after activating the motor output control device, the motor down control for temporarily increasing the rotation speed of the motor. Shift control method of an automatic transmission, characterized in that it comprises a timing control step for activating the shift control device.

[0035]

As described above, according to the first aspect, when the vehicle is switched to the low gear, it is determined whether the vehicle before or after the shift is in a driven or driven state, and based on the determination result, the prime mover By reducing the output, it is possible to obtain excellent effects that the shift shock can be reduced and the shift time can be shortened.

According to the second aspect of the present invention, the downshift control is started after detecting that the vehicle before the shift is in the driven state, so that a good shift can be achieved even when the prime mover is in the high-speed rotation region. An excellent effect that characteristics can be obtained and shift shock can be further reduced can be obtained.

Further, in common with the above invention, the downshift is performed while the accelerator opening is larger than the idling state and the vehicle is traveling in an ambiguous driving state in which it is difficult to determine whether the vehicle is in the driving state or the driven state. Even when the shift is performed, a remarkable effect that the shift time can be shortened while the shock during the shift is reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing a second embodiment of the present invention.

FIG. 3 is a time chart showing the first embodiment of the present invention.

FIG. 4 is a time chart showing the second embodiment of the present invention.

FIG. 5 is a characteristic diagram of an accelerator opening showing another embodiment of the present invention.

FIG. 6 is a main configuration diagram of a shift control device of the automatic transmission.

[Explanation of symbols]

1 a shift signal detection step, 2 drive state analysis steps, 3 motor output control steps, 7 driven state detection steps, 8 downshift control steps, 9 timing control steps.

Claims (2)

[Claims] When the automatic transmission is downshifted to a lower gear in order to produce a braking action, the frictional engagement device on the higher gear to be released begins to slip and then engages during the downshift. A downshift control device for temporarily increasing the rotation speed of the prime mover until the low-speed-stage friction engagement device is completely engaged; and A timing control device for starting after a lapse of time, the shift control device for an automatic transmission, comprising: when the automatic transmission is switched to a low gear, a drive state of the vehicle is detected, and the vehicle before and after the shift is driven or A driving state analysis device that determines whether the vehicle is in the driven state; and, based on the determination result of the driving state analysis device, reduces the output of the prime mover to change the vehicle before the shift from the driving state to the driven state. A motor output control device, and the timing control device that activates the downshift control device to temporarily increase the rotation speed of the motor after the motor output control device is activated. Transmission control device for transmission. 2. The downshift control device according to claim 1, wherein the timing control device activates the downshift control device after detecting that the vehicle has been driven before shifting.
A shift control device for an automatic transmission according to claim 1.