JPH05338469A - Speed shift controller for automatic transmission - Google Patents

Abstract

PURPOSE:To conduct engine control by means of timing that is according to the action state of a vehicle by starting output increase control after the lapse of a set timing time so as to raise an engine rotation number from the slip start of the high speed step side of a friction engaging device till the complete engagement of the low speed step side, at the time of down shift. CONSTITUTION:A transmission control computer 34 decides a speed shift step by means of the solenoid signal of a friction engaging device, and in the case of down shift, controls the rotary speed of an engine 10 during a time that is from the slip start of the high speed step side of an automatic transmission 78 and till the next low speed step side is completely engaged. In this instance, a timing time that is from a measuring start time point fixed previously by means of a speed shift output means till output increase control start, is set in consideration of oil temperature in the hydraulic control circuit 150 of a hydraulic sensor 86, an engine rotary speed by means of a rotary angle sensor 51 or the like, and after the lapse of this time, the output increase control of the engine 10 is commenced. Accordingly, a speed shift time is shortened, and the worsening of an operation feeling at the time of speed shift can be restrained.

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 downshifting when an accelerator is substantially off.

[0002]

2. Description of the Related Art An automatic vehicle provided with an automatic transmission in which a plurality of shift stages are established by switching a hydraulic control circuit and changing engagement states of a plurality of friction engagement devices such as a hydraulic clutch and a brake. However, in such an automatic vehicle, when sufficient engine braking force cannot be obtained even when the accelerator is turned off on a downhill road, the driver turns off the overdrive switch or shift lever. The engine braking force is increased by switching from the D range to the S range and the L range to perform a downshift. Further, when the acceleration of the vehicle is non-negative or the vehicle speed continues to increase for a certain period of time in the accelerator off state, automatic engine brake control for automatically downshifting to increase engine braking force may be performed. For example, JP-A-62-246650 and JP-A-61-1
It is disclosed in Japanese Patent Publication No. 03044.

By the way, when the downshift for increasing the engine braking force is performed in the accelerator-off state as described above, the gear ratio of the automatic transmission becomes large in the downshift, so that it is necessary to increase the rotational speed of the engine accordingly. There is. In this case, since the throttle valve is normally closed during such engine braking, the frictional engagement device on the low speed stage for achieving the shift stage after the downshift, for example, the torque transmission on the output side by the torque transmission of the hydraulic clutch and brake. Is transmitted to the engine side, so that the rotation speed of the engine is increased. For this reason, the gear shift time becomes long, the friction energy amount of the hydraulic clutch and brake increases, the life of the friction material decreases, and the inertia torque accompanying the increase of the engine rotation speed appears as the braking torque of the vehicle, resulting in a temporary However, there was a problem that the engine braking force was increased to cause a shift shock. Further, when the transmission torque of the hydraulic clutch or brake is suddenly increased by hydraulic control of the automatic transmission, etc., the engine rotation speed rapidly rises and the shift time is shortened, but the braking torque sharply increases and the shift shock further increases. .

On the other hand, the applicant of the present application, in reference No. TSN920603 of the patent application dated April 27, 1992, (a) downshifts to a low speed stage in which the automatic transmission is in an engine brake state while the accelerator is substantially OFF. The engine output increasing means for temporarily increasing the engine output when the engine is operated, and (b) measuring the elapsed time from a predetermined measurement start time point such as a shift output time point when the hydraulic control circuit is switched during the downshift. A timer,
(B) Based on the elapsed time measured by the timer, the low-speed gear that is engaged during the downshift after the friction engagement device on the high-speed gear side that is released during the downshift begins to slip. The engine output by the engine output increasing means when a predetermined timing time with reference to the measurement start time elapses so that the engine rotation speed increases until the frictional engagement device on the side is completely engaged. Has proposed a shift control device for an automatic transmission, which is provided with a timing control means for starting the increase control. That is, after the shift output is made to perform the downshift,
While there is a delay before the friction engagement device of the automatic transmission is actually released or engaged, the engine output actually rises after the throttle opening control is performed to increase the engine output. There is a delay until you do so,
The timing time is set in advance in consideration of these delay times, so that the shift time is shortened while suppressing the shift shock, and the life of the friction engagement device is prevented from being shortened. Further, in order to effectively reduce the shift time, it is desirable to control the opening of the throttle valve so that the engine blows up at the timing when the frictional engagement device on the high speed stage side starts to slip.

[0005]

However, the delay time until the friction engagement device is actually disengaged or engaged varies depending on, for example, the oil temperature in the hydraulic control circuit, while the engine output actually changes. Since the delay time until it rises to 0 changes depending on, for example, the engine rotation speed, if the timing time is set to a constant value while ignoring such an operating state of the vehicle, the timing of engine blow-up shifts and The shortening effect may not be sufficiently obtained, or the driving feeling may be deteriorated due to an increase in driving torque. For example, in FIG. 23, when the timing of the throttle opening control is early, the drive torque increases before shifting as shown in the D section, which may cause the driver to feel uncomfortable and the engine to be driven. Further, FIG. 24 shows a case where the timing of the throttle opening control is late, and not only the effect of shortening the shift time is not sufficiently obtained, but also the engine rotation speed can be clearly understood from the graph of the speed ratio N _T / NE of the torque converter. The braking torque is temporarily increased because the NE is forcibly increased, and a sufficiently satisfactory driving feeling cannot always be obtained.

The present invention has been made in view of the above circumstances. An object of the present invention is to control the increase of the engine output at an appropriate timing according to the operating state of the vehicle. .

[0007]

To achieve this object, the timing time may be set based on the operating conditions of the vehicle such as the oil temperature of the hydraulic control circuit and the engine speed. As shown in the claim correspondence diagram of FIG. 1, (a) an automatic transmission in which a plurality of shift speeds are established by switching a hydraulic control circuit and changing engagement states of a plurality of friction engagement devices. And (b) a gear shift output means for switching the hydraulic control circuit to change the gear stage of the automatic transmission, and (c) a low gear stage in which the automatic transmission operates with engine braking while the accelerator is in a substantially OFF state. A shift control device for an automatic transmission, comprising: an engine output increasing means for increasing an engine output when a downshift is performed. A timer for measuring an elapsed time from a predetermined measurement start point in relation to the switching time of the hydraulic control circuit; Engagement of the friction engagement device so that the engine speed increases until the low-speed stage friction engagement device that is engaged during the downshift is completely engaged after the occurrence of , Based on the operating state of the vehicle that affects at least one of the release delay time and the increase delay time of the engine output,
Timing time setting means for setting a timing time until the engine output increasing control is started by the engine output increasing means on the basis of the measurement start time point,
(F) timing control means for starting the engine output increase control by the engine output increasing means when the elapsed time measured by the timer exceeds the timing time set by the timing time setting means. Is characterized by.

[0008]

In such a shift control device for an automatic transmission, a timer for the time elapsed from the start of measurement, which is predetermined in relation to the switching time of the hydraulic pressure control circuit by the shift output means, is used for downshifting. The friction engagement device on the low speed stage side that is engaged during the down shift after the start of slippage on the friction engagement device on the high speed stage side, which is released during the down shift, is completely engaged. The timing time until the engine output increasing means starts the engine output increasing control on the basis of the measurement start time is set by the timing time setting means so that the engine rotation speed increases until the engine speed is increased. The elapsed time measured by the timer has passed the timing time set by the timing time setting means. , The increase control of the engine output by the engine output increasing means is initiated by the timing control means. In this case, in the present invention, the engagement / release delay time of the friction engagement device, that is, the delay time from the switching time of the hydraulic control circuit by the shift output means to the actual engagement / release of the friction engagement device. , And an operating state of the vehicle that affects at least one of an increase delay time of the engine output, that is, a delay time from the start time of the engine output increase control until the engine output is actually increased,
For example, since the timing time is set based on the oil temperature in the hydraulic control circuit, the engine speed, etc., it is possible to control the increase of the engine output at an appropriate timing regardless of the difference in the vehicle operating state. Therefore, the shift time can be more surely shortened, and the driving feeling during the shift is prevented from being deteriorated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 2, in the combustion chamber 12 of the gasoline engine 10, an air cleaner 14, an air flow meter 16, an intake passage 18, a throttle valve 20, a bypass passage 22, a surge tank 24, an intake manifold 26,
And air is taken in through the intake valve 28,
Fuel gas injected from a fuel injection valve 30 provided in the intake manifold 26 is mixed with the air. The air flow meter 16 measures the intake air amount, and outputs a signal indicating the intake air amount to the engine control computer 32. Throttle valve 20
Is for continuously changing the amount of air taken into the engine 10. The throttle valve opening θ is controlled in accordance with the throttle control signal DTA supplied from the throttle control computer 35, and The valve 20 is provided with a throttle position sensor 36, and outputs a throttle valve opening signal Sθ representing the throttle valve opening θ to the engine control computer 32, the transmission control computer 34, and the throttle control computer 35. Bypass passage 2
2 is arranged in parallel with the throttle valve 20 and has an idle speed control valve 3 in its bypass passage 22.
8 is provided, and an engine control computer 32
By controlling the opening degree of the idle speed control valve 38, the amount of air that bypasses the throttle valve 20 is adjusted to control the engine speed during idling. The injection timing and the injection amount of the fuel injection valve 30 are also controlled by the engine control computer 32. An intake air temperature sensor 40 for measuring the temperature of intake air is provided upstream of the air flow meter 16, and a signal representing the intake air temperature is sent to the engine control computer 32.
Output to.

The engine 10 includes an intake valve 28 and an exhaust valve 4
2, a piston 44, and a spark plug 46. The spark plug 46 generates an ignition spark by a high voltage supplied from an igniter 48 controlled by the engine control computer 32 through a distributor 50. , The crankshaft is rotated by exploding the mixed gas in the combustion chamber 12 and moving the piston 44 up and down. The intake valve 28 and the exhaust valve 42 are adapted to be opened and closed by a cam shaft which is rotationally driven in synchronization with the rotation of the crankshaft, and by a variable valve timing mechanism (not shown) controlled by the engine control computer 32. The opening / closing timing is adjusted by changing the rotation phases of the camshaft and the crankshaft. The exhaust gas burned in the combustion chamber 12 is exhausted from the exhaust valve 42 to the exhaust manifold 5
4, the exhaust passage 56, and the catalyst device 58 to be discharged to the atmosphere. The engine 10 is provided with a water temperature sensor 60 for measuring the engine cooling water temperature, which outputs a signal representing the engine cooling water temperature to the engine control computer 32, and at the same time, the exhaust manifold 5
4 is an oxygen sensor 62 for detecting the oxygen concentration in the exhaust gas.
Is provided and outputs a signal indicating the oxygen concentration to the engine control computer 32. Further, the distributor 50 is provided with a rotation angle sensor 51 that generates a pulse in synchronization with the rotation of the crankshaft. The pulse signal, that is, the engine rotation speed signal SNE representing the engine rotation speed NE is sent to the engine control computer 32 and Output to the transmission control computer 34.

The engine control computer 32, the transmission control computer 34, and the throttle control computer 35 are all CPU, RAM, R.
The transmission control computer 34 includes an OM, an input / output interface circuit, an A / D converter, and the like, and performs signal processing according to a program stored in advance in the ROM while utilizing the temporary storage function of the RAM. In addition to the above signals, is a pattern signal SP indicating a selection pattern from the pattern select switch 70, a brake signal SB indicating that the brake is operated by the brake lamp switch 72, and an overdrive switch 74 to an O / D shift stage. O / indicating gear shift permission
The D signal SO and the accelerator operation amount signal SA indicating the operation amount Ac of the accelerator pedal are supplied from the accelerator operation amount sensor 76, respectively. The accelerator operation amount signal SAc is also supplied to the engine control computer 32 and the throttle control computer 35. The pattern select switch 70 has a plurality of predetermined traveling patterns such as a power pattern for performing shift control of the automatic transmission 78 according to a shift map that emphasizes power performance and an economy pattern for performing shift control according to a shift map that emphasizes fuel efficiency. The driver selects and operates a desired driving pattern from among the above. Further, the brake lamp switch 72 is arranged in the vicinity of the brake pedal, and is constituted by an ON-OFF switch or the like which can be turned ON / OFF depending on whether or not the brake pedal is depressed.

The automatic transmission 78 includes a torque converter 110, a first transmission 112, and a second transmission 114, as shown in FIG. 3, for example. The pump impeller of the torque converter 110 is connected to the crankshaft 118 of the engine 10, and the turbine impeller of the torque converter 110 is the input shaft 1.
It is connected to the carrier 122 of the first transmission 112 via 20. The first transmission 112 is configured to include a sun gear 124, a ring gear 126, and a planetary gear device that includes a planetary gear 128 that is rotatably disposed on the carrier 122 and meshes with the sun gear 124 and the ring gear 126. 124 and carrier 1
22 and a clutch C ₀ and a one-way clutch F _0.
Are provided in parallel, and the sun gear 124 and the housing 130
A brake B ₀ is provided between and.

The second transmission 114 is rotatably disposed on the sun gear 132, the pair of ring gears 134 and 136, and the carrier 138 so as to be rotatable on the sun gear 132, the planetary gear 140 meshed with the ring gear 134, and the carrier 142. The planetary gear 1 that is arranged and meshes with the sun gear 132 and the ring gear 136.
44, and a clutch C ₁ is provided between the ring gear 136 and the ring gear 126 of the first transmission 112, and between the sun gear 132 and the ring gear 126. Clutch C
₂ is provided, a brake B ₁ is provided between the sun gear 132 and the housing 130, and a one-way clutch F ₁ and a brake B ₂ that are provided in series are provided in parallel. A brake B ₃ and a one-way clutch F ₂ are provided in parallel with each other. Further, the ring gear 134 and the carrier 142 are the output shaft 1
46, and its output shaft 146 is connected to the drive wheels via a differential gear device or the like.

The clutches C _{0 to} C ₂ and the brake B
_{0 to} B ₃ (hereinafter, unless otherwise specified, the clutch C,
The brake B) is a hydraulic friction engagement device that is engagement-controlled by a hydraulic actuator such as a multi-plate clutch or band brake, and hydraulic oil is supplied from the hydraulic control circuit 150 to the hydraulic actuator. Is becoming The hydraulic control circuit 150 is provided with a large number of switching valves and the like, and by switching the excitation and non-excitation of the solenoids S1, S2, and S3 in accordance with a signal from the transmission control computer 34, the hydraulic circuit is switched. The clutch C and the brake B are selectively engagement-controlled, and as shown in FIG. 4, any one of the four forward gears is established. In FIG. 4, the "○" mark in the solenoid column indicates excitation, the "X" mark indicates non-excitation, the "○" mark in the clutch and brake columns indicates engagement, and the "X" mark indicates release.
The shift positions “D”, “S”, and “L” are the operating ranges of the shift levers in the driver's seat, and are “D (drive)”.
In the range, shift control is performed in four steps from 1st to O / D, and in the "S (second)" range, 1st and 2n
The gear shift control is performed in two gears d, and is fixed to the first gear in the “L (low)” range. The gear ratio (rotational speed of the input shaft 120 / rotational speed of the output shaft 146) is the largest at 1st, becomes smaller as it becomes 2nd, 3rd, and O / D, and the gear ratio at 3rd is 1.0. Further, in the "D" range, the engine brake operates at 3rd and O / D, and at the 1st and 2nd, the one-way clutches F ₂ , F
Engine braking does not work due to the action of ₁ , but "S"
In the 2nd range and the 1st range of the "L" range, the solenoid S3 is excited to actuate the engine brake. Although illustration is omitted,
When the shift lever is operated to the "R (reverse)" range, the manual shift valve of the hydraulic control circuit 150 is switched to establish the reverse gear.

The automatic transmission 78 is provided with a pair of rotation speed sensors 80 and 82. The rotation speed sensor 80 is the input shaft 120, that is, the torque converter 11.
The rotation speed sensor 82 detects the rotation speed N _T of the turbine impeller of 0, and the rotation speed sensor 82 detects the rotation speed N _O of the output shaft 146. The rotation speed signals representing the rotation speeds N _T and N _O , respectively. SN _T, and outputs the SN _O to the transmission control computer 34. Further, a neutral start switch 84 is provided in the hydraulic control circuit 150, and the "D", "S", from the position of the manual shift valve which is switched by operating the shift lever.
A shift range such as "L" or "R" is detected, and a shift range signal SR representing the shift range is output to the transmission control computer 34. The oil pressure control circuit 150 is also provided with an oil temperature sensor 86 for detecting the oil temperature THO of the hydraulic oil, and the oil temperature signal S indicating the oil temperature THO is provided.
The THO is output to the transmission control computer 34.

The control computers 32 and 3 are used.
Necessary information is transmitted and received between Nos. 4 and 35, and at least one of the control computers 32, 34, 34, Alternatively, it may be supplied to 35. In addition, various other signals that represent the operating state of the automobile, such as the steering angle of the steering wheel, the gradient of the road surface, and the exhaust temperature, can be captured and used for engine control, shift control of the automatic transmission 78, and throttle control. It is possible.

Then, the engine control computer 32 uses the intake air amount, the throttle valve opening θ, the engine rotational speed NE, the cooling water temperature of the engine 10, the intake air temperature, the oxygen concentration in the exhaust passage 56, and the accelerator operation. Quantity Ac
In accordance with the above, for example, the fuel injection valve 3 is based on a predetermined data map or an arithmetic expression so as to reduce fuel consumption and harmful exhaust gas while securing a required engine output.
It controls the injection amount and injection timing of the fuel gas by 0, the ignition timing by the igniter 48, the idle speed by the idle speed control valve 38, and the opening and closing timing of the intake and exhaust valves 28, 42 by the variable valve timing mechanism. The transmission control computer 34 controls the throttle valve opening θ, the engine speed NE, the selection pattern represented by the pattern signal SP, the presence / absence of a brake operation represented by the brake signal SB, and the O / D shift stage represented by the O / D signal SO. Whether or not shifting is possible, accelerator operation amount Ac, automatic transmission 78
Of the solenoid S based on the output shaft rotation speed N _{O of the}
By switching the excitation and non-excitation of 1, S2, and S3, the shift stage of the automatic transmission 78 is switched and controlled. The transmission control computer 34 also switches the lockup clutch of the torque converter 110 between full engagement, a slip state, and release by duty-controlling a solenoid (not shown) provided in the hydraulic control circuit 150. At the same time, a throttle command signal SQ is output to the throttle control computer 35 to control the throttle valve opening θ of the throttle valve 20. The throttle control computer 35 basically outputs a throttle control signal DTA for controlling the throttle valve opening θ according to the throttle command signal SQ.

Hereinafter, the shift control and the throttle control by the transmission control computer 34 will be specifically described with reference to the flow charts of FIGS. The flowcharts of FIGS. 5 to 7 relate to the shift control for switching the shift speed of the automatic transmission 78.
The flowchart of FIG. 8 relates to throttle control, and is repeatedly executed with a cycle time of about 8 to 32 msec.

First, in step SA1 of FIG. 5, it is judged based on the shift range signal SR whether or not it is currently in the "D" range, and if it is not in the "D" range, step SA of FIG.
13 and subsequent steps are executed, but in the case of the "D" range, step SA2 and subsequent steps are executed. In step SA2, O / D
Based on the signal SO, it is determined whether or not shifting to the O / D gear is possible. If the O / D signal SO is OFF, that is, the O / D gear is prohibited, the current O / D is determined in step SA3. It is determined whether or not it is the D shift stage. The current gear stage is determined by the output state of the excitation signal for exciting the solenoids S1, S2, S3. Here, the current O / D gear position means that the overdrive switch 74 has been turned OFF while traveling at the O / D gear position. In this case, in step SA11, the next gear position is set to "3rd". Is set. When the determination in step SA2 is NO, that is, when the O / D gear is allowed, or even when the determination in step SA2 is YES, it is not the current O / D gear and the determination in step SA3 is NO and the current 3rd is also set. If NO in step SA4, step SA5 is subsequently executed. In step SA5, it is determined whether or not the current shift speed is the O / D shift speed. If it is not the O / D shift speed, steps SA6 and subsequent steps are executed to determine whether or not an upshift is performed. .

At step SA6, a predetermined upshift map is searched to obtain the upshift vehicle speed Vu. As shown by the solid line in FIG. 9, the upshift map is predetermined for each type of shift based on the accelerator operation amount Ac and the vehicle speed V. The smaller the accelerator operation amount Ac is, the larger the vehicle speed V is. It is designed to be upshifted to the high speed side. Shift up vehicle speed Vu
It is determined according to the upshift map based on the accelerator operation amount Ac, in the next step SA7, the current vehicle speed V and the shift-up vehicle speed Vu that corresponds to the output shaft rotational speed N _O of the rotational speed signal SN _O represents Are compared with each other to determine whether to perform an upshift. That is,
If V ≦ Vu, it is not necessary to perform an upshift, and it is determined in step SA8 whether or not the current shift speed is 1st. If 1st, it is not necessary to perform a downshift determination, and therefore step SA28 in FIG. Do the following,
If V> Vu, in step SA11, a gear speed higher than the current gear speed is set as the next gear speed. In this case, even if the current shift speed is, for example, 2nd, the accelerator operation amount Ac sharply decreases after the shift determination to 3rd is made and before the shift speed is actually changed to 3rd. When the "3 → O / D" upshift line is exceeded, the O / D gear is set. In step SA6, the shift-up vehicle speed Vu for all upshift lines is obtained from the current accelerator operation amount Ac, and in step SA7, the respective shift-up vehicle speed Vu and the current vehicle speed V are compared to determine the upshift shift. Do it.

If the determination in step SA4 is YES, the determination in step SA5 is YES, or the determination in step SA8 is NO, steps SA9 and thereafter are executed to determine whether to downshift. To do. In step SA9, a predetermined downshift map is searched to obtain the downshift vehicle speed Vd. As shown by the broken line in FIG. 9, the downshift map is predetermined for each type of shift based on the accelerator operation amount Ac and the vehicle speed V, and as the accelerator operation amount Ac becomes larger and the vehicle speed V becomes smaller. It is designed to downshift to the lower speed side. The downshift vehicle speed Vd is obtained according to the downshift map based on the accelerator operation amount Ac, and in the next step SA10, the current vehicle speed V corresponding to the output shaft rotation speed N _O and the downshift vehicle speed V.
It is compared with d to determine whether to downshift.
That is, if V> Vd, it is not necessary to perform downshift, and step SA28 and subsequent steps in FIG. 7 are executed, but V ≦
In the case of Vd, in step SA11, a shift speed lower than the current shift speed is set as the next shift speed.
In this case, even if the current gear is O / D,
When the accelerator operation amount Ac suddenly increases after the shift determination to 3rd is made and before the shift stage is actually switched to 3rd and the "2 ← 3" downshift line is exceeded, The second gear is set. Step SA9
Then, the downshift vehicle speed Vd for all downshift lines is calculated from the current accelerator operation amount Ac, and step SA
At 10, the shift down vehicle speed Vd is compared with the current vehicle speed V to make a downshift shift determination.

In step SA13 of FIG. 6 executed when the range is not the "D" range, it is determined whether the range is the "S" range.
In case of "S" range, steps SA14 and SA
15, the current gear stage is O / D or 3 from the output state of the excitation signal for exciting the solenoids S1, S2, S3.
It is determined whether or not it is rd and O / D or 3
In the case of rd, 2n is set as the next gear in step SA16.
Set d. If the current gear is neither O / D nor 3rd, it is determined in step SA17 whether the current gear is 2nd. If it is 2nd, in step SA18, "1 ←" in FIG. 2 ”The downshift vehicle speed Vd is obtained from the downshift line based on the current accelerator operation amount Ac, and it is determined in step SA19 whether the current vehicle speed V is higher than the downshift vehicle speed Vd. If V ≦ Vd In step SA20, 1st is set as the next gear. If it is not 2nd, that is, if it is currently in the 1st speed stage, step SA21 is executed following step SA17, and
The shift-up vehicle speed Vu is obtained based on the current accelerator operation amount Ac from the "1 → 2" up-shift line, and it is determined in step SA22 whether the current vehicle speed V is equal to or lower than the shift-up vehicle speed Vu, and V> Vu. If so, 2nd is set as the next gear in step SA16.

If the range is not currently "S", step SA23 is executed after step SA13,
It is determined whether it is in the "L" range. Then, in the case of the "L" range, it is determined in steps SA24, SA25, SA26 whether or not the current shift speed is O / D, 3rd, or 2nd, and if O / D, 3rd, or 2nd. For 1s as the next gear in step SA27
Set t.

Steps SA8, SA10, SA1
9, the determination in SA22 is YES, or step SA26
If the determination is NO, that is, if the current gear is to be maintained, then step SA28 in FIG. 7 is executed to set the flags F1 and F2 to “0”, respectively,
In step SA29, the excitation signal of the solenoid is output so as to maintain the current gear. In addition, step SA1
If the next shift speed is set at 1, SA16, SA20, or SA27, then step SA in FIG.
12 is executed to set the shift timing time T1. This shift timing time T1 is a delay time until a shift output is performed to actually switch the shift stage after the shift determination is made (step SA34 in FIG. 7), and multiple shifts can be performed in a short time. It is provided to prevent (multiple shift), and a constant value may be set in advance, but the type of shift such as upshift or downshift, or which shift stage to which shift stage Different times may be set according to the above. In addition, the accelerator operation amount Ac and the vehicle speed V at the time of gear shift determination,
It is also possible to set it by a map, an arithmetic expression or the like according to the gear stage or the like.

When the shift timing time T1 is set in step SA12, then step SA3 in FIG.
Execute 0. In step SA30, it is determined whether or not the flag F1 is "0", and if F1 is not "0", steps SA32 and thereafter are executed, but if F1 = 0, after resetting the timer Ta in step SA31. , Step SA32 is executed to set the flag F1 to “1”. Since the flag F1 is set to "0" in step SA28 executed when maintaining the current gear,
It is "0" in the first cycle in which the next gear is set, and the timer Ta measures the elapsed time after the setting of the next gear.

At the next step SA33, it is judged whether or not the content measured by the timer Ta has passed the shift timing time T1, and when the shift timing time T1 has passed, at step SA34, the steps SA11, SA1.
6, the excitation signal of the solenoid for establishing the next gear set at SA20 or SA27 is output. Further, in step SA35, it is judged from the output state of the excitation signal whether or not the next shift stage established by the shift output of step SA34 is the low speed stage in which the engine brake acts, and in the low speed stage in which the engine brake acts. If there is, the flag F2 is set to "1" in step SA36, and if not, the flag F2 is set to "0" in step SA37.
And For shifting to the low speed stage in which the engine brake acts, for example, the O of the overdrive switch 74 is set.
There are shifts from O / D to 3rd due to FF operation, shifts to 2nd or 1st due to shift lever switching operation from D range to S range or L range, and the like.

Explaining the throttle control in FIG. 8, first, it is determined in step SB1 whether the flag F3 is "1". If F3 = 1, step S3 is executed.
B11 is executed, and if not, step SB2 is executed. In step SB11, it is determined whether or not the accelerator operation amount Ac is about 5% or less in the accelerator off state, and if the accelerator is in the off state, the steps in and after step SB8 are executed. After setting F3 to "0", in step SB13, the throttle valve opening θ is controlled according to the accelerator operation amount Ac. With this throttle control,
Based on the accelerator operation amount Ac represented by the accelerator operation amount signal SAc, the throttle valve opening degree TA (Ac) is obtained from a predetermined map or an arithmetic expression, and the throttle valve opening degree TA (Ac) is set to the target throttle valve opening degree. and sets the TA ^*, and outputs a throttle command signal SQ indicating the target throttle valve opening TA ^* to the throttle control computer 35. Throttle control computer 35
Indicates the actual throttle valve opening θ of the throttle valve 20 by the feedback control or the like.
The target throttle valve opening TA ^* represented by, that is, TA (A
The throttle control signal DTA is output to the throttle valve 20 so as to match c).

In step SB2, it is determined whether or not the flag F2 is "1", that is, it is a downshift to a low speed stage in which engine braking is applied. If F2 = 1, step SB3 is executed, but otherwise. Step SB12 and subsequent steps are executed. In step SB3, it is determined whether the accelerator is in the OFF state as in step SB11. If the accelerator is not in the OFF state, step S3 is executed.
Steps B12 and below are executed, but if the accelerator is off, steps SB4 and below are executed. Therefore, the steps subsequent to step SB4 are the same as those in step SA3.
4, a gearshift output for downshifting to a low speed stage in which the engine brake operates, and the accelerator OF
In the F state, in other words, it is executed when the downshift is performed by the manual operation of the overdrive switch 74 or the shift lever in order to increase the engine braking force.

In step SB4, the flag F3 is set to "1" so that step SB11 is executed subsequent to step SB1 from the next cycle. Also,
In step SB5, based on the type of shift to be downshifted and the current vehicle speed V, the driving force when the throttle valve 20 is fully closed (in this case, acts negatively and acts as a braking force) at the gear before the downshift. The throttle valve opening degree TA2 is set such that a driving force that is substantially the same or slightly smaller, that is, a driving force that makes the engine braking force substantially the same or slightly larger, is obtained even in the gear after the downshift, for example, as shown in FIG.
It is calculated by map interpolation from a prestored data map as shown in FIG. The data map in Figure 10 is
Based on the experimentally obtained data as shown in FIG. 11, the throttle valve opening such that the driving force is substantially equal before and after the shift is determined for each shift type and vehicle speed. The data of FIG. 11 shows that in the vehicle equipped with the engine having the output characteristics shown in FIG. 12, the gear stage of the automatic transmission 78 is O / D (total gear ratio = 2.8905),
Gear transmission efficiency is 0.855, tire effective radius is 0.30
For example, when the vehicle speed is 6 km and the vehicle speed is 80 km / h and the accelerator is off, the driving force is as shown by point B:
It is about 300N. Then, for example, in the case of downshifting from the O / D shift stage to the 3rd shift stage, the driving force in the data corresponding to FIG. 11 in the case of 3rd, that is, the driving force which is substantially the same as or slightly smaller than −300 N is 80 k.
The value of the throttle valve opening obtained at a vehicle speed of m / h is the throttle valve opening TA2. “O / D → 3rd” in FIG.
The throttle valve openings TA2 _{31 to} TA2 _3n at the time of gear shift are thus determined for each vehicle speed V _{1 to} V _{n, and} are set to “3r
The throttle valve opening degrees TA2 _{21 to} TA2 _2n at the time of gear shift “d → 2nd (S3 ON)” are also set in the same manner as above using the driving force data of the second gear. Although illustration is omitted, 2n in which the engine brake operates from the O / D gear
As for the other downshifts such as the shift to the d shift stage and the shift from the 3rd shift stage to the 1st shift stage where the engine brake acts, the throttle valve opening degree TA2 is obtained in the same manner as above, and a map is created. . The throttle valve opening TA2 increases as the vehicle speed increases in the same type of shift, and the same vehicle speed increases in the downshift on the low speed side than in the downshift on the high speed side.

In the following step SB6, the change timing time T2 of the throttle valve opening θ is set. This throttle valve opening change timing time T2 is the same as the above step S
It is the delay time from when the downshift gear shift output is made in A34 to when the throttle valve 20 is opened and controlled. The current engine speed NE and the oil temperature TH of the hydraulic control circuit 150 are adjusted so that the engine speed NE also rises.
It is calculated by map interpolation from the data map of FIG. 13 set in advance by experiments, simulations, etc. using O as a parameter. In this case, the higher the oil temperature THO, the lower the viscous resistance of the hydraulic oil, the shorter the time required for draining and applying, and the slippage of the clutch C and the brake B on the high speed stage side after the shift output is performed. Since the delay time until the start is short, the throttle valve opening change timing time T2 has a smaller value as the oil temperature THO is higher. Further, as the engine speed NE is higher, the delay time until the engine 10 actually blows up to the engine speed NE after the throttle valve 20 is opened and controlled becomes longer. Therefore, the throttle valve opening change timing time T2 is equal to the engine speed. The higher the speed NE, the smaller the value.

Here, referring to FIG. 14 which is a time chart when downshifting from the O / D gear to the 3rd gear, the throttle valve opening change timing time T
2 will be specifically described. First, at time t1, a shift output is made in step SA34, and the solenoid S2
Is turned on (excited), the valve of the hydraulic control circuit 150 is switched, so that the brake B ₀ , which is a friction engagement device at the O / D shift stage, is released during the O / D → 3rd downshift. The engagement oil pressure P _B0 is decreased, and the engagement oil pressure P _C0 of the clutch C ₀ , which is the friction engagement device of the 3rd gear shift stage and is engaged during the O / D → 3rd downshift, is increased. Time t2 is the engagement hydraulic pressure P
_The time at which the brake B ₀ starts to slide as B ₀ decreases, and at time t4, when the throttle valve 20 is in the fully closed state corresponding to the accelerator operation amount Ac, the torque is transmitted to the output side of the clutch C ₀ . By transmitting the torque to the engine 10 side, the engine rotation speed NE is increased as shown by the solid line, and the rotation speeds of the output side and the input side of the automatic transmission 78 are changed after the downshift. Is a time in which the clutch C ₀ is completely engaged by being synchronized in accordance with the above, and the time from this time t2 to t4 (t4-t2) is the shift time.

In the present embodiment, the gear shift time is shortened by temporarily opening the throttle valve 20 to raise the engine speed NE during the gear shift, but before the time t2 or before the time t4. When the engine speed NE later rises, the driving force increases and the vehicle accelerates. Therefore, in order to obtain the effect of shortening the shift time without causing the vehicle acceleration, the engine speed is at least between the times t2 and t4. It is necessary to determine the throttle valve opening change timing time T2 so that the speed NE increases. In that case, the delay time from the solenoid output time t1 to the sliding start time t2 of the friction engagement device fluctuates depending on the oil temperature THO, while the delay time from the opening control of the throttle valve 20 to the engine rotation speed NE increases. The change timing time T2 is set using these as parameters because they vary depending on the engine speed NE. That is, the oil temperature THO and the engine speed NE
Corresponds to the operating state of the vehicle that affects the engagement and disengagement delay time of the friction engagement device and the increase delay time of the engine output. In the present embodiment, the friction engagement device on the high speed stage side, which is released at the time of downshift, such as the above-mentioned O
13 for determining the change timing time T2 so that the engine rotation speed NE starts to rise at substantially the same time when the brake B ₀ starts to slide in the / D → 3rd downshift.
The map has been set. The rotation speed N _C0 in FIG. 14 is the rotation speed of the housing of the clutch C ₀ , in other words, the rotation speed of the sun gear 124 of the first transmission 112.

In the next step SB7, the timer Tb is reset, and in step SA34, the elapsed time after the shift output is performed is measured. That is, this step SB7
Indicates that the gear shift output is made in step SA34 and step S
It is first executed by setting the flag F2 to "1" in A36, and in the subsequent cycles, step SB
Since Step SB8 and the subsequent steps are executed after 1 and SB11, the timer Tb measures the elapsed time thereafter with the downshift gear shift output time as the measurement start time point. At Step SB8, it is judged whether or not the timed content of the timer Tb reaches the change timing time T2,
Step SB1 until the change timing time T2 is reached
In 3, the throttle valve opening degree θ is controlled so as to become the throttle valve opening degree TA (Ac) corresponding to the accelerator operation amount Ac, that is, substantially fully closed. When the content measured by the timer Tb reaches the change timing time T2, it is determined in step SB9 whether or not the shift is completed depending on whether or not the following expression (1) is satisfied. That is, when the shift output is performed in step S34 of FIG. 7 and the solenoids S1, S2, S3 are switched between energized and deenergized, slippage begins to occur in the clutch C and the brake B of the automatic transmission 78, and the turbine rotational speed N _Since the rotation speed ratio of _T and the output shaft rotation speed N _O substantially matches the gear ratio i of the current gear after the gear shift, that is, after the gear shift output, the gear shift ends, so the rotation speeds N _T , N _{When O 2} and the gear ratio i of the current gear position satisfy the following expression (1), the gear shifting is completed. The expression (1) is set so as to be satisfied with a predetermined width in consideration of the detection error of the rotation speeds N _T and N _O.

[0035]

## EQU1 ## N _T ≈N _O × i (1)

Then, the determination in step SB9 is YES.
Until S, in other words, until the shift is completed, the throttle valve opening degree TA2 is set to the target throttle valve opening degree TA ^* in step SB10, and the throttle command signal SQ representing the target throttle valve opening degree TA ^* is throttled. By outputting to the control computer 35, the actual throttle valve opening θ of the throttle valve 20 is controlled so as to become the throttle valve opening TA2.

As described above, in this embodiment, when a downshift is performed by manually operating the overdrive switch 74 or the shift lever in order to increase the engine braking force, the same drive as before the downshift is performed even after the downshift. Since the throttle valve 20 is controlled to be opened up to the throttle valve opening TA2 where the force can be obtained, the engine speed NE is rapidly increased, the shift time is shortened, and the life of the friction material of the clutch C and the brake B is improved. In particular, in the present embodiment, the throttle valve that opens and controls the throttle valve 20 so that the engine rotational speed NE increases at the timing when slippage occurs in the clutch C and the brake B on the high speed stage that is released by downshifting. Since the opening degree change timing time T2 is determined on the basis of the oil temperature THO and the engine rotation speed NE, it is possible to prevent the deviation of the engine blow-up timing due to the fluctuations thereof and surely obtain the effect of shortening the shift time. At the same time, deterioration of the driving feeling at the time of shifting due to an increase in driving torque is suppressed. Further, since the throttle valve opening change timing time T2 is set so that the engine rotational speed NE starts to rise at substantially the same time when the clutch C and the brake B on the high speed side start to slip, the shift time can be shortened most efficiently. is there. The graph shown by the alternate long and short dash line with respect to the rotation speed in FIG. 14 is that of this embodiment, and the time t3 is the shift end time of this embodiment.

The line oil pressure PL of the oil pressure control circuit 150 is generally controlled according to the throttle valve opening θ, and the line oil pressure PL is controlled when the throttle valve 20 is opened as described above. Since it is increased, the engaging hydraulic pressure of the clutch C and the brake B is also increased accordingly.
The shift time is further shortened by the sudden complete engagement of the clutch C and the brake B on the low speed stage side. However, in that case, since a large shift shock is likely to occur,
In this embodiment, during the opening control of the throttle valve 20 in step SB10, the line oil pressure PL is controlled to a low oil pressure level when the throttle valve 20 is fully closed.

In this embodiment, the part that executes step SA34 in the series of signal processing by the transmission control computer 34 corresponds to the shift output means, and the part that executes step SB6 is the engine rotation speed NE.
Together with the rotation angle sensor 51 for detecting the oil temperature and the oil temperature sensor 86 for detecting the oil temperature THO constitute a timing time setting means. In addition, steps SB1, SB2, SB4, S
The portion that executes B7, SB8 and SA36 corresponds to the timing control means, and the portion that executes steps SB5 and SB10 constitutes the engine output increasing means together with the throttle control computer 35 and the throttle valve 20.

Next, another embodiment of the present invention will be described. The following embodiment is a case where automatic engine braking control for automatically increasing the engine braking force by throttle control or downshifting is performed when the "D" range is selected. As shown in parentheses, by energizing the solenoid S3, the 1st gear shift stage and the 2nd gear shift stage where the engine brake acts are established. In addition to the power pattern, the economy pattern, and the like, an "automatic engine braking pattern" that automatically increases the engine braking force on a downhill is provided as a traveling pattern that can be selected by the pattern select switch 70.

FIGS. 15 and 16 are flow charts relating to the shift control of the automatic transmission 78, and FIGS. 17 to 19 are flow charts relating to the throttle control, which are repeatedly executed at a cycle time of about 8 to 32 msec as in the above embodiment. It Steps S1 and subsequent steps in FIG. 15 are a part for determining whether or not to change the shift stage of the automatic transmission 78, and are executed when step S40 is NO, that is, when the flag F3 is not "1". Flag F3
1 when all the conditions of steps SS1 to SS5 of FIG. 17 are satisfied and the automatic engine braking control is executed.
8 is set to "1" in step SS14 or SS19, and if any one of the conditions of steps SS1 to SS5 is not satisfied, it is set to "0" in step SS6. This is executed in the case of normal shift control in which the above is not performed.

In step S1, it is judged based on the O / D signal SO whether or not shifting to the O / D shift stage is possible, and the O / D signal SO is OFF, that is, the O / D shift stage is prohibited. If so, the current O /
It is determined whether or not it is the D shift stage. The current gear stage is determined by the output state of the excitation signal for exciting the solenoids S1, S2, S3. If the current gear stage is the O / D gear stage,
After the flag F2 is set to "1" in step S14,
In step S15, "3rd" is set as the next gear. The determination in step S1 is NO, that is, O / D.
If the gear is allowed, or if the determination in step S1 is YES, it is not the current O / D gear, the determination in step S2 is NO, and the determination is not 3rd at step S2.
If the determination in 3 is NO, then step S4 is executed. In step S4, it is determined whether or not the current gear is the O / D gear, and if it is not the O / D gear, in steps S5 and S6 the same as steps SA6 and SA7 in the above-described embodiment. Determine whether to upshift. If the upshift is not performed, it is determined in step S8 whether or not the current gear is 1st, and if it is 1st, the flag F1 is set to "0" in step S9 and the series of gear shift determination is completed. However, in the case of upshifting, the flag F1 is set to "1" in step S7, and then, in step S15, the shift speed higher than the current shift speed is set as the next shift speed.

If the determination in step S3 is YES,
If the determination in step S4 is yes, or
If the determination in step 8 is NO, steps S10 and S1
In step 1, it is determined whether or not the downshift is to be performed, as in steps SA9 and SA10 in the above embodiment. If the downshift is not performed, the flag F2 is set to "0" in step S13 to end the series of shift determinations. If the downshift is to be performed, the flag F2 is set to "1" in step S12 In step S15, a shift speed lower than the current shift speed is set as the next shift speed.

If YES at step S40, that is, if automatic engine braking control is being executed, step S41 is executed after step S40.
It is determined whether the flag F5 is "0". The flag F5 is
If the conditions of steps SS1 to SS5 in FIG. 17 are all satisfied and the automatic engine braking control is executed and the brake is depressed, it is set to “1” in step SS23 in FIG. 18, and otherwise. Step SS
6 or SS12 is set to "0", and if the flag F5 = 0, step S42 is executed, and if the flag F5 = 1, step S45 is executed. In step S45, which is executed when the brake pedal is depressed, a predetermined downshift map for engine braking is searched to obtain a downshift vehicle speed Ved for engine braking. The downshift map during engine braking is predetermined for each type of shift based on the accelerator operation amount Ac and the vehicle speed V, like the normal downshift map shown by the broken line in FIG. , It is easier to downshift because it deviates to the higher vehicle speed side than the normal downshift map. Downshift vehicle speed Ved
Is obtained according to the downshift map during engine braking based on the accelerator operation amount Ac, and in the next step S46, the current vehicle speed V corresponding to the output shaft rotation speed N _O is compared with the downshift vehicle speed Ved. ,
Determine whether to downshift. That is, V>
If it is Ved, it is not necessary to perform the downshift, and the flag F2 is set to "0" in step S44 to complete the shift determination. However, if V≤Ved, the flag F2 is set to "1" in step S47, and then In step S48, a shift speed lower than the current shift speed is set as the next shift speed. The gear set here is one in which the engine brake acts, and in the 2nd or 1st stage, the
The gears shown in parentheses in are set.
In this case, even if the current gear is O / D,
After the gear shift determination to 3rd is made and before the gear shift to 3rd is actually performed, the vehicle speed V sharply decreases to "2.
← 3 "When the downshift line is exceeded, the 2nd shift speed is set. In step S45, the downshift vehicle speed Ved for all downshift lines is obtained from the current accelerator operation amount Ac, and in step S46, each downshift vehicle speed Ved is compared with the current vehicle speed V to make a downshift determination. Do it.

In step S42 executed when the brake pedal is not depressed, it is determined whether the flag F4 is "1". The flag F4 is set to "1" in step R8 of FIG. 19 when the downshift is performed to increase the engine braking force in the automatic engine braking control, and when the downshift gear shift output is performed, the flag F4 of FIG. It is set to "0" in step S31, and F4 =
If it is 0, the flag F2 is set to "0" in step S44.
Then, the shift determination is ended, and if F4 = 1, step S
Execute 43. In step S43, the next low speed stage where the engine brake acts as the next shift stage, that is, 2n
In the case of d or 1st, the gear stage shown in parentheses in FIG. 20 is set.

When the next shift speed is set in step S15, S43, or S48, the shift timing time T1 is set in step S16.
This shift timing time T1 is a delay time until a shift output is performed to actually switch the shift stage after the shift determination is made (step S30), and multiple shifts can be performed in a short time (multiple shift). ), And if the accelerator pedal is quickly released to activate the engine braking on a downhill, even if an upshift decision to the O / D gear is made, before the actual upshift is performed. It is provided to prohibit upshifting to the O / D gear when the accelerator operation amount Ac becomes substantially zero.
Although a fixed value may be set in advance, different times may be set according to the type of shift such as upshift or downshift, or downshift in automatic engine braking control. Further, it may be set by a map, a calculation formula or the like according to the accelerator operation amount Ac at the time of gear shift determination, the vehicle speed V, the gear position and the like.

Next, the flow chart of FIG. 16 for actually changing the shift speed will be described. FIG. 16 shows a portion for executing an upshift and a downshift for increasing the engine braking force in accordance with the shift determination shown in FIG. Determine whether or not If the flag F1 is "1", step S
21. The following steps are executed. If not, step S33 is executed. In step S33, it is determined whether or not the flag F4 is "1", that is, whether or not the downshift is to increase the engine braking force. If the flag F4 is "1", the steps from step S21 are executed. If not, step S32 is immediately executed, the timer Ta is reset, and the process ends.

In step S21, the shift range signal SR
It is determined whether the shift range represented by is "D", in step S22 it is determined whether the traveling pattern represented by the pattern signal SP is an "automatic engine braking pattern", and in step S23 the rotational speed signal is determined. vehicle speed V corresponding to the output shaft rotation speed N _O of SN _O represents it is determined whether larger than the lower limit vehicle speed V1 to a predetermined, step S
At 24, it is determined whether or not the vehicle speed V is equal to or lower than a predetermined upper limit vehicle speed V2. At step S25, the accelerator is turned off.
That is, it is determined whether or not the accelerator operation amount Ac represented by the accelerator operation amount signal SAc is substantially zero, specifically, about 5% or less in consideration of a detection error and the like, and in step S26, it is set in step S15. Also, it is determined whether the next gear is the O / D gear. Lower limit vehicle speed V1 and upper limit vehicle speed V
2 defines a vehicle speed range in which special control for engine braking is performed, and the lower limit vehicle speed V1 is, for example, 20 km /
The vehicle speed is set to about h and the upper limit vehicle speed V2 is, for example, 110 km /
It is set to about h. Then, the above steps S21 to S
If even one of 26 is NO, in step S28, the change in the next gear set in step S15 is not changed in step S27.
If the determinations of 1 to S26 are all YES, step S
At 27, the next gear is changed to "3rd". In addition,
In step S26, it is determined whether or not the next shift speed set in step S15 is O / D.
Even in the cycle after the next shift speed is changed from O / D to 3rd in 7, the determination in step S26 is YES.

In step S29, it is determined whether or not the content measured by the timer Ta is equal to or longer than the shift timing time T1. The above steps S20 and thereafter are repeated until the shift timing time T1 is reached, but when the shift timing time T1 is reached, step S30 is executed and the solenoid S1,
The excitation and non-excitation of S2 and S3 are switched to switch the shift stage of the automatic transmission 78 to the next shift stage set in step S15 or S43 or the 3rd shift stage changed in step S27. After that, the flag F1 is set to "0" and the flag F4 is set to "0" in step S31, and the timer Ta is reset in step S32.

Here, in step S6, O / D
Even if an upshift determination to the shift stage is made, step S
Until the gear is actually changed at 30
That is, the shift timing time T after the shift determination is made.
If all of the conditions of steps S21 to S26 including the accelerator OFF are satisfied before the lapse of 1, the next shift stage is changed to 3rd, and further speedup is disliked on a downhill or the like. If the driver releases the accelerator pedal, the actual shift to the O / D shift stage is prevented even if the upshift shift determination is made as the accelerator operation amount Ac decreases, and the O / D shift stage is prevented. The reduction in engine braking force due to the shift to is favorably avoided. For example, when the driver releases the accelerator in the case of traveling for the second time at the state of point A in FIG. 9, “2 →
Since the accelerator operation amount Ac becomes zero across the "3" upshift line and the "3 → O / D" upshift line, a final shift determination from 2nd to O / D is made in step S6. In step S15, the O / D shift stage is set as the next shift stage, but if the accelerator operation amount Ac becomes zero before the shift timing time T1 elapses after the "2 → 3" upshift determination is made, " 3 → O / D ”
Even if the next shift speed becomes O / D across the upshift line, the next shift speed is changed to 3rd in step S27, and therefore the upshift to the O / D shift speed is not performed.

Even if the accelerator is turned off once,
If the pedal is depressed again before reaching the shift timing time T1, the determination in step S25 is NO, and in step S28 the next shift stage is set to the O / D set in step S15. When the pedal is depressed, the driver does not need the engine braking force so much, and therefore the driver may upshift to the O / D gear. Even if the determination of step S29 is inserted between steps S20 and S21, the determination of step S21 and subsequent steps is executed based on the operating state when the shift timing time T1 has elapsed, and the gear shift is performed. good.

Also, the accelerator return speed is relatively slow,
Even when the accelerator is not turned off within the shift timing time T1, the shift as set in step S15 is executed, but in this case as well, it is considered that the driver does not need so much engine braking force, so O / There is no problem in upshifting to the D gear. In other words,
When the driver needs the engine braking force, he / she should release the accelerator pedal promptly, and when he / she wants to coast or the like which does not require the engine braking force so much, he / she should release the accelerator pedal slowly. It's good.

Next, the throttle control of FIGS. 17 to 19 will be described. First, steps SS1 to S of FIG.
In S5, the steps S21 to S regarding the shift range, the traveling pattern, the vehicle speed V, and the accelerator operation amount Ac are performed.
When the same judgment as 25 is made and all the conditions are satisfied, the automatic engine braking control of step SS8 and thereafter is executed. However, if any one of them is NO, the flag F3 is set to "6" in step SS6 of FIG. When the flag F5 is set to "0" and the flag F5 is set to "0", normal throttle control is performed in step SS7. The normal throttle control in step SS7 has the same contents as in step SB13 in the above-described embodiment, and based on the accelerator operation amount Ac represented by the accelerator operation amount signal SAc, the throttle valve opening TA ( Ac), and the throttle valve opening TA (Ac) is calculated as the target throttle valve opening TA
Set to ^* and the target throttle valve opening TA
By outputting the throttle command signal SQ indicating ^* to the throttle control computer 35, the throttle valve 2
The actual throttle valve opening θ of 0 is controlled so as to match the throttle valve opening TA (Ac).

In step SS8, which is executed when all the conditions in steps SS1 to SS5 are satisfied, the flag F
It is determined whether or not 3 is "1", but this flag F3
Is set to "0" in step SS6, so it is "0" when step SS8 is first executed,
Then, step SS10 is executed to set the vehicle speed V at that time to the target vehicle speed Vm. Since the flag F3 is set to "1" in step SS14 or SS19 in FIG. 18, the determination in step SS8 is YES in the subsequent cycles.
Then, step SS9 is executed. In step SS9, the vehicle speed (Vm-Vf) obtained by subtracting a predetermined constant value Vf from the target vehicle speed Vm is compared with the vehicle speed V at that time. If V> (Vm-Vf), step SS in FIG.
11 is executed, but if V ≦ (Vm−Vf), step SS10 is executed again, and after changing the target vehicle speed Vm to the vehicle speed V at that time, steps SS11 and thereafter are executed.
Considering the fluctuation of the vehicle speed V due to the feedback control of the throttle valve opening θ in steps R2 and R4 of FIG. 19, the constant value Vf is determined to be NO in step SS9 depending on the fluctuation of the vehicle speed V accompanying the throttle control. Although it does not occur, the vehicle speed V
Is relatively low, the determination in step SS9 is NO, and the target vehicle speed Vm is changed in step SS10.

In step SS11 of FIG. 18, it is judged whether or not the brake pedal is operated based on the brake signal SB. If the brake is OFF, that is, if the brake pedal is not operated, step SS12 and the following steps are executed. When the person desires further deceleration and depresses the brake, the determination in step SS11 becomes NO, and steps SS22 and SS23 are executed. Step SS2
In No. 2, the target throttle valve opening TA ^{* is set} to 0 in order to increase the engine braking force, and the throttle command signal SQ representing the target throttle valve opening TA ^* is output to the throttle control computer 35, whereby the throttle valve is opened. 20 is fully closed. Further, in step SS23, the flag F5 is set to "1", and the step S45 in FIG.
Make sure that: At the beginning of the automatic engine braking control, that is, in the first cycle when the accelerator is turned off, the normal brake is turned off, and step SS
The determination of 11 is YES and the step SS14 or S
The flag F3 is set to "1" in S19, and
In step S41, the steps following the engine braking are executed.

Step SS executed when the brake is OFF
In step 12, the flag F5 is set to "0", and in step SS13, it is determined whether or not the flag F1 is "1".
In step 6, it is determined whether or not the upshift is determined. When the flag F1 = 1, the flag F3 is set to "1" in step SS14, and then the normal throttle control similar to that in step SS7 is performed in step SS15. Further, if the upshift gearshift determination is not made, or if the upshift gearshift output is made and the flag F1 is set to "0" in step S31 of FIG. 16, the determination at step SS13 is NO. Then, in step SS16, it is determined whether the flag F6 is "0". The flag F6 is set to "1" in step R8 of FIG. 19 when a downshift is performed to increase the engine braking force, and when flag F6 = 0, the flag F3 is already set to "1" in step SS17. 1 "
Or not. When the flag F3 = 1,
In step SS18, it is determined whether or not gear shifting is in progress, for example, the rotational speeds N _T and N _O , and the gear ratio i of the current gear stage.
Is determined by whether or not the above equation (1) is satisfied.
When the expression (1) is satisfied, the gear is not being changed, and when the expression (1) is not satisfied, the gear is being changed.

If the determination in step SS18 is YES, that is, if the gear shift is not in progress, the automatic engine brake throttle processing routine in step SS21 is executed. If the gear shift is in progress, step SS20 is executed.
Further, the flag F3 is not "1" in the first cycle of the automatic engine braking control, and the determination in step SS17 is N.
In the case of O, the flag F3 is set to "1" in step SS19 and then step SS20 is executed to perform the same normal throttle control as in step SS7.

In the automatic engine brake throttle processing routine of step SS21, the actual vehicle speed V is set as shown in FIG.
In this embodiment, the throttle valve opening θ is feedback-controlled so that the vehicle speed V substantially matches the target vehicle speed Vm so as not to exceed the target vehicle speed Vm set in step SS10 of FIG. It is executed according to the flowchart of. In step R1 of FIG. 19, the actual throttle valve opening θ represented by the throttle valve opening signal Sθ is shown.
Is smaller than a predetermined judgment value θ1. The determination value θ1 is a small value of about 5% or less, and can be determined using an idle signal or the like indicating that the throttle valve opening θ is substantially fully closed. Then, when θ ≧ θ1, that is, when the engine braking force can be increased by closing the throttle valve opening θ,
Step R2 is executed, and the throttle valve opening degree TA1 (%) for making the vehicle speed V substantially match the target vehicle speed Vm is calculated according to the calculation formula of the feedback control according to the deviation between the target vehicle speed Vm and the current vehicle speed V. .

In the next step R3, based on the current gear position and the target vehicle speed Vm, the throttle valve opening that can maintain the target vehicle speed Vm in flatland traveling, that is, the driving force in consideration of running resistance becomes zero. Throttle valve opening TAm
(%) Is calculated by map interpolation from a pre-stored data map shown in FIG. 21, for example, and it is determined whether the throttle valve opening degree TA1 is smaller than the throttle valve opening degree TAm. The data map of FIG. 21 is obtained based on the driving force data shown in FIG. 11 for the throttle valve opening at which the driving force matches the running resistance for each shift speed and vehicle speed. For example, when the vehicle speed is 80 km / h, the throttle valve opening degree TAm (%) is about 7. The throttle valve opening degree (angle) at the point C that matches the running resistance on a flat ground is about 7.
Since it is 4 °, when it is converted into% with respect to 80 ° when fully opened, it becomes (7.4 / 80) × 100 = 9.3. That is, in the data map of FIG. 21, the throttle valve opening degree TA when the vehicle speed is 80 km / h at the O / D gear position
₄₅ is specifically 9.3%, and in this way O /
Throttle valve opening degree TA _{41 to} T for each vehicle speed in the D shift stage
A ₄₇ is required. As for the 3rd gear shift stage and the 2nd gear shift stage and the 1st gear shift stage where the engine brake operates, the throttle valve opening degrees TA _{31 to} TA ₃₇ , TA ₂₁ to TA ₂₇ , TA ₁₁ TA ₁₇
Is required. As is clear from the data in FIG. 11, the throttle valve opening degree TAm increases as the vehicle speed increases, and if the vehicle speed is the same, the throttle gear opening TAm increases as the gear shift ratio decreases and the shift speed increases. Note that the 2nd and 1st shift speeds in FIG. 21 are shift speeds when the engine brake acts, that is, the solenoid S3 is turned on.

If TA1 <TAm, the throttle valve opening degree TA1 is set to the target throttle valve opening degree TA ^* in step R4, and the target throttle valve opening degree T is set.
By outputting the throttle command signal SQ representing A ^* to the throttle control computer 35, the actual throttle valve opening θ of the throttle valve 20 is changed to the throttle valve opening T.
It is controlled to be A1. These steps R2, R
By repeatedly executing 3 and R4, the throttle valve opening θ is rapidly controlled so that the vehicle speed V substantially matches the target vehicle speed Vm, and the target vehicle speed Vm when the accelerator is off or the vehicle speed V decreases due to the brake depression operation. The engine braking force with which the vehicle travels at the target vehicle speed Vm that has been changed is obtained. In this embodiment, the vehicle speed V is set to the target vehicle speed Vm.
Since the throttle valve opening θ is feedback-controlled so as to substantially match with, the vehicle speed V
The engine braking force is increased / decreased to substantially match the target vehicle speed Vm, and when the gradient changes from a steep gradient to a gentle gradient, it is prevented that the vehicle speed V is lowered against the driver's will due to excessive engine braking. It

[0061] On the other hand, the determination in step R3 in the case of TA1 ≧ TAM sets NO, in step R5 of the throttle valve opening TAM to the target throttle valve opening degree TA ^*, representing the target throttle valve opening TA ^* By outputting the throttle command signal SQ to the throttle control computer 35, the actual throttle valve opening θ of the throttle valve 20 is controlled to be the throttle valve opening TAm. This is because the engine braking force is increased / decreased so that the vehicle speed V substantially matches the target vehicle speed Vm regardless of the change in the road surface gradient as described above, and therefore the throttle valve opening θ Is opened and the vehicle speed V is maintained at the target vehicle speed Vm. However, with such engine braking control, the driver usually thinks that the vehicle speed V decreases on an uphill road, and when driving on a flat ground. If so, the throttle valve opening TAm that can maintain the target vehicle speed Vm is set as the upper limit of the throttle valve opening TA1 by the feedback control. As a result, the target vehicle speed Vm is maintained on the downhill and the flat ground, but the vehicle speed V becomes lower than the target vehicle speed Vm according to the gradient on the uphill, so that the driving control as intended by the driver is performed. Become so.

When the throttle valve 20 is almost fully closed and the engine braking force cannot be increased by the above throttle control, the determination at step R1 becomes YES, and steps R6 and thereafter are executed. In step R6, it is determined whether or not the current vehicle speed V is higher than the target vehicle speed Vm. If V> Vm, steps R8 and below are executed.
When V ≦ Vm, that is, when the engine is being decelerated by the engine braking action due to the throttle valve 20 being fully closed, there is no need to perform a downshift, so in the subsequent step R7, the target throttle valve opening degree TA ^{* is set} to 0. Is set. However, when the vehicle is accelerating beyond the target vehicle speed Vm, the flag F4 instructing the downshift in order to increase the engine braking force is set to "1" in step R8, and the throttle control during the downshift is performed. The flag F6 is set to "1". When the flag F4 is set to "1", step S43 of FIG.
When the flag F6 is set to "1", steps SS24 and the following steps in FIG. 18 are executed. Further, in step R9, a driving force that is substantially the same as or slightly smaller than the driving force before the shifting, that is, a driving force that makes the engine braking force approximately the same or slightly larger, is generated based on the type of downshifting and the current vehicle speed V. Throttle valve opening TA that can be obtained even after shifting
2 is calculated by map interpolation from the data map of FIG. 10 in the same manner as in step SB5, and step R
At 10, the throttle valve opening change timing time T2 is set. The throttle valve opening change timing time T2 is
The delay time until the throttle valve 20 is actually opened and controlled based on the time when the downshift gear shift output is performed in step S30, and the clutch C and the brake B on the high speed stage side are released by the downshift. The engine speed NE and the oil temperature THO of the hydraulic control circuit 150 are used as parameters so that the engine speed NE rises corresponding to the throttle valve opening degree TA2 in accordance with the timing at which slippage occurs. It is calculated by map interpolation from the data map of FIG. 13 set by the above.

When the flag F6 is set to "1" in step R8, in the subsequent cycles, step SS in FIG.
The result of the determination in 16 is NO, and step SS24 is executed. In step SS24, it is determined whether or not the shift output for the downshift is performed in step S30 and the flag F4 is set to "0" in the next step S31. Until F4 = 0, the timer is set in step SS25. When Tb is reset and F4 = 0, steps SS26 and thereafter are executed. By resetting the timer Tb in step SS25, the timer Tb measures the elapsed time when the flag F4 is set to "0", in other words, when the downshift gearshift output is made, At step SS26, the timer T
It is determined whether or not the timing content of b is not less than the throttle valve opening change timing time T2. When the time the contents of the timer Tb reaches the change timing period T2, the throttle valve opening TA2 is set to the target throttle valve opening TA ^* In step SS27, the throttle command signal SQ indicating the target throttle valve opening TA ^* Is output to the throttle control computer 35 to control the actual throttle valve opening θ of the throttle valve 20 to be the throttle valve opening TA2. In addition, the next step SS
At 28, it is judged from the above formula (1) whether or not the gear shift is completed based on the gear ratio i of the current gear stage after the downshift gear shift output and the rotational speeds N _T and N _O. ,
When the shift is completed, the flag F6 is set in step SS29.
Is set to "0". As a result, in subsequent cycles, step SS16 and subsequent steps are executed after step SS16.

As described above, in this embodiment, when the downshift is performed when the accelerator is off to increase the engine braking force, the driving force after the downshift is substantially the same as or slightly smaller than the driving force before the downshift. Since the throttle valve 20 is controlled to open up to the throttle valve opening TA2,
The engine speed NE is quickly increased, the shift time is shortened, and the life of the friction material of the clutch C and the brake B is improved. In particular, in this embodiment, the engine speed N is accurately adjusted according to the timing at which the clutch C or the brake B on the high speed stage side, which is released by the downshift, begins to slip.
Since the throttle valve opening change timing time T2 for controlling the opening of the throttle valve 20 so as to increase E is determined based on the engine speed NE and the oil temperature THO, the engine blow-up timing due to these fluctuations The shift is prevented, the effect of shortening the shift time is surely obtained, and the deterioration of the driving feeling due to the temporary increase of the drive torque or the like is suppressed.

In the present embodiment, of the series of signal processing by the transmission control computer 34, the part that executes step S30 corresponds to the shift output means, and the part that executes step R10 is the rotation angle sensor 51 and the oil temperature sensor. Together with 86, a timing time setting means is configured. Also, steps S31, SS24, SS25, S
The part that executes S26 corresponds to the timing control means,
The portion that executes steps R9 and SS27 constitutes the engine output increasing means together with the throttle control computer 35 and the throttle valve 20.

FIG. 22 shows a vehicle speed of 55 km / h on an 8% downhill due to the automatic engine braking control of this embodiment.
7 is a time chart showing changes in rotational speed and changes in driving torque of various parts when a downshift is performed from the 3rd shift stage to the 2nd shift stage at the time of, and opening control of the throttle valve 20 is performed at an appropriate timing. The shift is completed in about 0.69 seconds without increasing the driving torque. On the other hand, FIG. 23 shows the throttle valve 20.
Accelerator is turned off when the timing of opening control is early
Regardless of the state, the driving torque temporarily increases as shown in the D section, which causes the driver to feel uncomfortable. Also, FIG.
When the opening control timing of the throttle valve 20 is late, the effect of shortening the shift time is not sufficiently obtained, and the braking torque is temporarily increased during the shift due to the inertia of the engine 10 or the like, which is not always satisfactory. I can't get the driving feeling.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be embodied in other modes.

For example, in the above embodiment, step SA34
Alternatively, when the shift output in step S30 is used as the measurement start time, the elapsed time is measured by the timer Tb and the timing for controlling the opening of the throttle valve 20 is controlled. For example, steps SA11, SA16, SA
It is also possible to control the timing of opening the throttle valve 20 by measuring the elapsed time with the time when the shift judgment is made to perform the downshift such as 20, SA27, or step R8 as the measurement start time. The throttle valve opening change timing time T2 is set in consideration of the shift timing time T1.

Further, in the above-described embodiment, the map of FIG. 13 for obtaining the throttle valve opening change timing time T2 in step SB6 or step R10 shows the friction engagement device on the high speed stage side which is released during downshift. Although it has been specified that the engine rotational speed NE starts to rise at substantially the same time as the start of slipping, the engine output should be increased at least from the start of slipping to the time when the friction engagement device on the low speed stage side is completely engaged. It should be fixed.

Further, in the above embodiment, the hydraulic control circuit 150
Although the throttle valve opening change timing time T2 is set based on the oil temperature THO and the engine speed NE of the above, it is possible to use only one of them or to use a parameter other than this. The throttle valve opening change timing time T2 may be set.

Although the engine output is increased by controlling the opening of the throttle valve 20 in the above embodiment, an engine auxiliary device such as an alternator may be used or the idle speed control valve 38 may be controlled to open. It is also possible to increase the engine output.

In the above embodiment, the throttle valve opening θ
Although the vehicle controlled by the throttle control computer 35 has been described above, the present invention is also applicable to a vehicle in which the throttle valve 20 is mechanically connected to an accelerator pedal to open and close. The configuration of the automatic transmission 78 and the number of gears can be changed as appropriate.

Further, in the above-described embodiment, when the downshift is performed when the accelerator is off, the throttle valve opening degree TA is such that the driving force before and after the shift is substantially the same based on the type of shift and the vehicle speed.
2 was set, but the crankshaft 118
The predetermined value ΔTA may be added in consideration of the inertia of the torque converter 110 or the like, or the opening may be temporarily widened until the engine speed rises. Regardless of this, a fixed value may be set. Further, similarly to the throttle valve opening ATm, it is possible to set the throttle valve opening at which the driving force becomes 0 at the gear after the gear shift to TA2, such that it is appropriately set at least within the range where the engine is not driven. can do.

Further, in the above embodiment, the accelerator operation amount Ac
The throttle valve 20 was controlled to open when a downshift was performed in a substantially complete accelerator off state of about 5% or less, but an engine with a negative drive torque even if the accelerator is not completely off. When braking
The effect of the present invention can be obtained by controlling the opening of the throttle valve 20. Whether or not the drive torque is negative can be detected, for example, by comparing the engine rotation speed NE with the turbine rotation speed N _T of the torque converter 110.

Further, in the second embodiment, the automatic engine braking control of step SS8 and thereafter is executed on condition that the automatic engine braking pattern is selected by the pattern select switch 70. It is also possible to perform the automatic engine braking control when another traveling pattern is selected, or to execute the automatic engine braking control regardless of the type of the traveling pattern. It is of course possible to dispose the engine brake control switch separately from the pattern select switch 70.

In the second embodiment, steps SS3 and SS are set as conditions for performing automatic engine braking control.
Although the vehicle speed limit of 4 is provided, the vehicle speed limit is not always necessary, and the range of the vehicle speed limit is appropriately determined. Other conditions may be added as conditions for performing automatic engine braking control.

In the second embodiment, step SS10 is executed every time the determination in step SS9 becomes NO as the vehicle speed V decreases, and the target vehicle speed Vm is sequentially changed according to the vehicle speed V at that time. However, it does not matter if the step SS9 is omitted and the target vehicle speed Vm is changed by the vehicle speed V when the brake is released, or the target vehicle speed Vm is sequentially updated when the brake is turned on based on the vehicle speed V. Absent.

Further, in the second embodiment, even if the next shift speed is changed to 3rd in step S27 of FIG. 16, if the accelerator is depressed before the shift timing time T1, the next shift speed is set in step S28. Is returned to O / D, but if the next gear is changed to 3rd in step S27, step S30 may be executed immediately before gear shift timing time T1 is reached, and gear shift output may be performed.

Further, in the second embodiment, the accelerator is turned off.
The vehicle speed V at the time of braking or when the brake is released was set to be the target vehicle speed Vm as it is, but the target vehicle speed Vm does not have to completely match the vehicle speed V, and a predetermined value is set for the vehicle speed V in consideration of measurement error and the like. Target vehicle speed Vm by adding or subtracting
May be set.

In the second embodiment, the throttle valve opening θ is feedback-controlled so that the vehicle speed V matches the target vehicle speed Vm. However, the throttle valve opening θ is increased / decreased by a predetermined constant amount ΔTA. It is also possible to use other control methods such as controlling the throttle valve opening θ by a fixed amount ΔTA so that the vehicle speed V does not exceed the target vehicle speed Vm. The constant value Vf in step SS9 is set in consideration of the fluctuation of the vehicle speed V accompanying the control of the throttle valve opening θ. The present invention can be similarly applied to other automatic engine braking control such as controlling the engine braking force so that the acceleration becomes negative.

Further, although the engine control computer 32, the transmission control computer 34, and the throttle control computer 35 are separately configured in the above embodiment, they may be configured by a single computer. It is possible.

Although not illustrated one by one, the present invention can be carried out in variously modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

FIG. 2 is a diagram illustrating a configuration of an automatic transmission, an engine, and the like including a shift control device that is an embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of the automatic transmission of FIG.

FIG. 4 is a diagram showing a shift speed of each shift range and an excitation state of a solenoid for achieving the shift speed, and engagement states of a clutch and a brake in the embodiment of FIG.

5 is a flowchart illustrating the operation of the shift control for switching the shift speed of the automatic transmission of FIG. 2 together with FIGS. 6 and 7.

6 is a flowchart illustrating the operation of the shift control for switching the shift speed of the automatic transmission of FIG. 2 together with FIG. 5 and FIG. 7.

7 is a flowchart illustrating the operation of the shift control for switching the shift speed of the automatic transmission of FIG. 2 together with FIGS. 5 and 6.

8 is a flowchart illustrating an operation of controlling a throttle valve opening of the engine of FIG.

9 is an example of a shift map for switching the shift speed of the automatic transmission of FIG.

FIG. 10 is an example of a data map used when setting the throttle valve opening degree TA2 in which the driving force before and after the shift is substantially the same in step SB5 of FIG.

11 is basic data for creating the data map of FIG.

FIG. 12 is data showing the output characteristics of the engine used to obtain the basic data of FIG.

13 is an example of a data map used when setting a throttle valve opening change timing time T2 in step SB6 of FIG.

FIG. 14 shows the automatic transmission of FIG. 2 at 3rd from the O / D gear stage.
5 is a time chart showing changes in hydraulic pressure and rotation speed of each part when downshifting to a shift stage.

FIG. 15 is a flowchart illustrating an operation of determining a shift whether or not to change a shift stage of an automatic transmission according to another embodiment of the present invention.

16 is a flowchart for explaining the operation of the shift control for switching the shift speed of the automatic transmission in the embodiment of FIG.

FIG. 17 is a flowchart for explaining the operation of controlling the throttle valve opening of the engine in the embodiment of FIG. 15 together with FIG.

FIG. 18 is a flowchart for explaining the operation of controlling the throttle valve opening of the engine in the embodiment of FIG. 15 together with FIG.

FIG. 19 is a flowchart for explaining the contents of the automatic engine brake throttle processing routine of FIG.

20 is a diagram showing a gear position of each shift range in the embodiment of FIG. 15 and an excitation state of a solenoid for establishing the gear position, and engagement states of a clutch and a brake.

FIG. 21 is an example of a data map used when calculating the throttle valve opening degree TAm in step R3 of FIG.

FIG. 22 is a diagram showing the second to third gears in the embodiment of FIG.
7 is a time chart showing changes in the rotation speed and drive torque of each part when a downshift is performed to the nd shift stage.

FIG. 23 is a time chart when the timing of throttle opening control is early, and is a diagram corresponding to FIG. 22.

24 is a time chart when the timing of throttle opening control is late, and is a diagram corresponding to FIG. 22.

[Explanation of symbols]

10: Engine 20: Throttle valve 34: Transmission control computer 35: Throttle control computer 51: Rotation angle sensor 78: Automatic transmission 86: Oil temperature sensor 150: Hydraulic control circuit C ₀ , C ₁ , C ₂ : Clutch ( Friction engagement device) B ₀ , B ₁ , B ₂ , B ₃ : Brake (friction engagement device) Tb: Timer T2: Throttle valve opening change timing time Step SA34: Shift output means Steps SA36, SB1, SB2, SB4 , SB7,
SB8: Timing control means Steps SB5, SB10: Engine output increasing means Step SB6: Timing time setting means Step S30: Shift output means Steps S31, SS24, SS25, SS26: Timing control means Steps R9, SS27: Engine output increasing means Step R10 : Timing time setting means

Claims (1)

[Claims] 1. An automatic transmission in which a plurality of shift stages are established by switching a hydraulic control circuit to change engagement states of a plurality of friction engagement devices, and a shift stage of the automatic transmission is changed. In order to achieve this, a shift output means for switching the hydraulic control circuit, and an engine output increasing means for increasing the engine output when the automatic transmission is downshifted to a low speed stage where the engine brake acts while the accelerator is in a substantially OFF state. A shift control device for an automatic transmission, comprising: a timer for measuring an elapsed time from a measurement start time point predetermined in relation to a switching time of the hydraulic pressure control circuit by the shift output means during the downshift, After the friction engagement device on the high speed stage side, which is released during the downshift, begins to slip, the friction engagement device on the low speed stage side is engaged during the downshift. Affects at least one of the engagement and disengagement delay time of the friction engagement device and the increase delay time of the engine output so that the engine rotation speed increases until the friction engagement device is completely engaged. Timing time setting means for setting a timing time until the engine output increasing means starts increasing control of the engine output based on the operating state of the vehicle, based on the measurement start time point, and the elapsed time measured by the timer. Is provided with timing control means for starting the increase control of the engine output by the engine output increasing means when the timing time set by the timing time setting means has elapsed. .