JP2924463B2 - Transmission control device for automatic transmission - Google Patents

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 with an accelerator substantially in an OFF state.

[0002]

2. Description of the Related Art An automatic vehicle equipped with an automatic transmission in which a plurality of gears can be established by changing a state of engagement of a plurality of friction engagement devices such as a hydraulic clutch and a brake by switching a hydraulic control circuit. In such automatic vehicles, when sufficient engine braking force cannot be obtained even when the accelerator is turned off on a downhill or the like, the driver turns off the overdrive switch or shifts the shift lever. Is switched from the D range to the S range and the L range to perform a downshift, thereby increasing the engine braking force. Also, when the acceleration of the vehicle is other than 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 and increasing the engine braking force may be performed. For example, JP-A-62-246650 and JP-A-61-1
No. 03044 and the like.

When the downshift is performed to increase the engine braking force when the accelerator is in the off state, the speed ratio of the automatic transmission is increased in the downshift, so the engine speed must be increased accordingly. There is. In this case, since the throttle valve is normally closed during the engine braking, the torque on the output side is transmitted by a torque engagement device on a low speed side, such as a hydraulic clutch or a brake, for achieving the shift speed after the downshift. Is transmitted to the engine side, thereby increasing the rotation speed of the engine. For this reason, the shift time becomes longer, the amount of friction energy of the hydraulic clutch and the brake becomes larger, and the life of the friction material is shortened. In addition, there is a problem that the engine braking force is increased to cause a shift shock. Also, when the transmission torque of the hydraulic clutch or the brake is rapidly increased by the hydraulic control of the automatic transmission or the like, the engine rotation speed is quickly increased and the shift time is shortened, but the braking torque is sharply increased and the shift shock is further increased. .

On the other hand, the applicant of the present application has filed a patent application No. TSN920603 filed on Apr. 27, 1992 in which (a) the automatic transmission is downshifted to a low gear where the engine brake operates with the accelerator substantially in the OFF state. (B) measuring an elapsed time from a predetermined measurement start time, for example, a shift output time at which the hydraulic control circuit is switched when downshifting. A timer,
(B) based on the elapsed time measured by the timer, the low-speed gear engaged at the time of the downshift after the friction engagement device of the high-speed gear released at the time of the downshift begins to slip; The engine output is increased by the engine output increasing means when a predetermined timing time has elapsed based on the measurement start time so that the engine rotation speed increases until the friction engagement device on the side is completely engaged. And a timing control means for starting the increase control of the automatic transmission. That is, after a shift output is performed to perform a downshift,
There is a delay before the frictional engagement device of the automatic transmission is actually released or engaged, but the engine output actually increases after the throttle opening control is performed to increase the engine output Because there is a delay time before doing
The timing time is set in advance in consideration of these delay times, whereby 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 friction engagement device on the high-speed stage starts to slip.

[0005]

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

The present invention has been made in view of the above circumstances, and an object of the present invention is to perform an increase control of an engine output at an appropriate timing according to an operation state of a vehicle. .

[0007]

In order to achieve the above object, the timing time may be set based on the operating state 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 to change an engagement state of a plurality of friction engagement devices. (B) shift output means for switching the hydraulic control circuit to change the shift speed of the automatic transmission, and (c) shifting to a low speed position where the automatic transmission operates with the engine brake when the accelerator is substantially OFF. A shift control device for an automatic transmission comprising: an engine output increasing means for increasing an engine output when downshifting; A timer for measuring an elapsed time from a predetermined measurement start time in relation to the switching time of the hydraulic control circuit; and (e) slipping on the frictional engagement device on the high speed stage released at the time of the downshift. The friction engagement device is engaged so that the engine rotational speed is increased until the low-speed-stage friction engagement device engaged during the downshift is completely engaged after the start of the engagement. , Based on the operating state of the vehicle affecting at least one of the release delay time and the engine output increase delay time,
Timing time setting means for setting a timing time until the engine output increase control is started by the engine output increase means based on the measurement start time;
(F) timing control means for starting the engine output increasing control by the engine output increasing means when the elapsed time measured by the timer has elapsed the timing time set by the timing time setting means. It is characterized by.

[0008]

In such a shift control apparatus for an automatic transmission, the time elapsed from the start of measurement, which is predetermined in relation to the switching time of the hydraulic control circuit by the shift output means at the time of downshifting, is determined by the timer. The frictional engagement device on the low speed side which is engaged during the downshift after the slippage begins to occur in the frictional engagement device on the high speed side which is released during the downshift and is released during the downshift is completely engaged. The timing time until the engine output increase control is started by the engine output increase means is set by the timing time setting means based on the measurement start time so that the engine rotational speed increases until the engine rotation 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. An operating state of the vehicle that affects at least one of an engine output increase delay time, i.e., a delay time from the start time of the engine output increase control to the time when the engine output is actually increased.
For example, since the above-mentioned timing time is set based on the oil temperature in the hydraulic control circuit, the engine rotation speed, and the like, the engine output increase control is performed at an appropriate timing regardless of such a difference in the vehicle operation state. As a result, the shift time can be more reliably reduced, and the deterioration of the driving feeling during the shift can be suppressed.

[0009]

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

Referring to FIG. 2, in a combustion chamber 12 of a 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 sucked in through the intake valve 28,
A 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 amount of intake air, and outputs a signal indicating the amount of intake air to the computer 32 for engine control. Throttle valve 20
Is for continuously changing the amount of air sucked into the engine 10. The throttle valve opening .theta. Is controlled in accordance with a throttle control signal DTA supplied from a throttle control computer 35. The valve 20 is provided with a throttle position sensor 36, and outputs a throttle valve opening signal Sθ indicating 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 disposed in parallel with the throttle valve 20 and has an idle speed control valve 3
8 and an engine control computer 32
The opening degree of the idle speed control valve 38 is controlled by the control, whereby the amount of air flowing bypassing the throttle valve 20 is adjusted, and the engine speed during idling is controlled. The injection timing and 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 the intake air is provided upstream of the air flow meter 16, and a signal representing the intake air temperature is sent to an 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 an engine control computer 32 via a distributor 50. The crankshaft is rotated by causing the mixed gas in the combustion chamber 12 to explode and move the piston 44 up and down. The intake valve 28 and the exhaust valve 42 are opened and closed by a cam shaft that is driven to rotate in synchronization with the rotation of the crankshaft, and is controlled by a variable valve timing mechanism (not shown) controlled by the engine control computer 32. The opening and closing timing is adjusted by changing the rotational phase of the camshaft and the crankshaft. The exhaust gas burned in the combustion chamber 12 is supplied from the exhaust valve 42 to the exhaust manifold 5.
4. The gas is discharged to the atmosphere via the exhaust passage 56 and the catalyst device 58. The engine 10 is provided with a water temperature sensor 60 that measures the temperature of the engine cooling water. The water temperature sensor 60 outputs a signal representing the temperature of the engine cooling water to the computer 32 for controlling the engine.
4 is an oxygen sensor 62 for detecting the oxygen concentration in the exhaust gas.
And outputs a signal indicating the oxygen concentration to the computer 32 for engine control. The distributor 50 is provided with a rotation angle sensor 51 that generates a pulse in synchronization with the rotation of the crankshaft, and outputs a pulse signal, that is, an engine rotation speed signal SNE representing the engine rotation speed NE, to the engine control computer 32 and the Output to the transmission control computer 34.

The computer 32 for engine control, the computer 34 for transmission control, and the computer 35 for throttle control are all CPU, RAM, R
The transmission control computer 34 includes an OM, an input / output interface circuit, an A / D converter, etc., and performs signal processing according to a program stored in the ROM while utilizing a temporary storage function of the RAM. Are the above signals, the pattern signal SP representing the selected pattern from the pattern select switch 70, the brake signal SB representing that the brake has been depressed from the brake lamp switch 72, and the overdrive switch 74 to the O / D gear. O / indicating the shift permission of
A D signal SO and an accelerator operation amount signal SAc representing 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 computer 32 for engine control and the computer 35 for throttle control. The pattern select switch 70 has a plurality of predetermined traveling patterns, such as a power pattern for performing a shift control of the automatic transmission 78 based on a shift map emphasizing power performance, and an economy pattern for performing a shift control based on a shift map emphasizing fuel efficiency. The driver selects and operates a favorite traveling pattern from among the above. The brake lamp switch 72 is provided near the brake pedal, and is configured by an ON-OFF switch or the like that is turned on and 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, for example, as shown in FIG. The pump wheel of the torque converter 110 is connected to the crankshaft 118 of the engine 10, and the turbine wheel is connected to the input shaft 1.
20 is connected to the carrier 122 of the first transmission 112. The first transmission 112 includes a planetary gear unit including a sun gear 124, a ring gear 126, and a planetary gear 128 rotatably disposed on the carrier 122 and meshing with the sun gear 124 and the ring gear 126. 124 and carrier 1
22 and the clutch C ₀ and the one-way clutch F ₀
Are provided in parallel, the sun gear 124 and the housing 130
Brake B ₀ is provided between the.

The second transmission 114 is rotatably disposed on the sun gear 132, the pair of ring gears 134, 136, and the carrier 138, and is rotatable on the planetary gear 140 meshed with the sun gear 132, the ring gear 134, and the carrier 142. The planetary gear 1 disposed and engaged with the sun gear 132 and the ring gear 136
44, a clutch C ₁ is provided between the ring gear 136 and the ring gear 126 of the first transmission 112, and a clutch C ₁ is provided between the sun gear 132 and the ring gear 126. Has a clutch C
₂ is provided between the brake B ₁ represents between the sun gear 132 and the housing 130, and a one-way clutch F ₁ and the brake B ₂ which are disposed in series are provided in parallel, the carrier 138 and the housing 130 brake B ₃ and the one-way clutch F ₂ is provided in parallel to the. The ring gear 134 and the carrier 142 are connected to the output shaft 1.
The output shaft 146 is connected to drive wheels via a differential gear device or the like.

[0015] The clutch C ₀ -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 controlled to be engaged by a hydraulic actuator such as a multi-plate clutch or a band brake so that hydraulic oil is supplied from a hydraulic control circuit 150 to the hydraulic actuator. Has become. The hydraulic control circuit 150 is provided with a number of switching valves and the like, and the solenoids S1, S2, and S3 are switched between energized and de-energized in accordance with signals from the transmission control computer 34, thereby switching the hydraulic circuit. The engagement of the clutch C and the brake B is selectively controlled, and one of the four forward speeds is established, as shown in FIG. In FIG. 4, the mark “の” in the solenoid column indicates excitation, the mark “x” indicates non-excitation, the mark “○” in the clutch and brake column indicates engagement, and the mark “x” indicates release.
"D", "S", and "L" of the shift position are the operating ranges of the shift lever in the driver's seat, and "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 shift control is performed in two stages of d, and is fixed to the first shift stage 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, decreases as 2nd, 3rd, and O / D, and the gear ratio at 3rd is 1.0. In the “D” range, the engine brake is applied at 3rd and O / D, and the one-way clutches F ₂ , F at 1st and 2nd.
_The engine brake does not work due to the action of ₁ , but "S"
In 2nd of the range and 1st of the “L” range, the engine brake is operated by exciting the solenoid S3. 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 connected to the input shaft 120, that is, the torque converter 11.
Detects the rotational speed N _T of the turbine impeller of 0, the rotational speed sensor 82 is for detecting the rotational speed N _O of the output shaft 146, the rotational speed N _T, respectively, the rotational speed signal representing the N _O It outputs SN _T and 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",
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 hydraulic control circuit 150 is further provided with an oil temperature sensor 86 for detecting the oil temperature THO of the working oil, and an oil temperature signal S representing the oil temperature THO.
The THO is output to the transmission control computer 34.

The control computers 32, 3
Necessary information is exchanged between 4 and 35. The throttle valve opening signal Sθ, the engine rotation speed signal SNE, and the accelerator operation amount signal SAc are at least one of the control computers 32, 34, Or, it may be supplied to 35. Further, various other signals indicating the driving state of the vehicle, such as the steering angle of the steering wheel, the gradient of the road surface, the exhaust temperature, etc., may be taken in and used for engine control, shift control of the automatic transmission 78, and throttle control. It is possible.

The engine control computer 32 calculates the intake air amount, the throttle valve opening θ, the engine 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. Amount Ac
In accordance with, for example, the fuel injection valve 3 based on a data map or an arithmetic expression determined in advance to reduce fuel consumption and harmful exhaust gas while securing necessary engine output,
It controls the fuel gas injection amount and injection timing 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 and 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 the brake operation represented by the brake signal SB, and the O / D shift speed represented by the O / D signal SO. Whether or not a shift can be performed, accelerator operation amount Ac, automatic transmission 78
Based like the output shaft rotation speed N _O of the solenoid S
By switching between excitation and non-excitation of S1, S2, and S3, the shift speed of the automatic transmission 78 is switched. The transmission control computer 34 also switches between a completely engaged state, a slipped state and a released state by duty-controlling a solenoid (not shown) provided in the hydraulic control circuit 150 also for the lock-up clutch of the torque converter 110. The 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 in accordance with the throttle command signal SQ.

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

First, in step SA1 in FIG. 5, it is determined whether or not the current range is the "D" range based on the shift range signal SR.
Steps 13 and below are executed, but in the case of the “D” range, steps SA2 and below are executed. In step SA2, O / D
It is determined based on the signal SO whether or not the shift up to the O / D shift stage is possible. If the O / D signal SO is OFF, that is, if the O / D shift stage is prohibited, the current O / D shift stage is determined in step SA3. It is determined whether or not the gear is the D gear. The current gear position is determined based on the output state of the excitation signal for exciting the solenoids S1, S2, and S3. Here, the current O / D gear position means that the overdrive switch 74 has been turned OFF during traveling at the O / D gear position. In this case, in step SA11, "3rd" is set as the next gear position. Is set. If the determination in step SA2 is NO, that is, if the O / D gear is permitted, or if the determination in step SA2 is YES, the current gear is not the O / D gear and the determination in step SA3 is NO and the current gear is 3rd. If the determination in step SA4 is NO, step SA5 is subsequently executed. In step SA5, it is determined whether or not the current gear is the O / D gear. If not, it is determined in step SA6 and subsequent steps whether or not an upshift is to be performed. .

In step SA6, a predetermined upshift map is searched to determine an upshift vehicle speed Vu. The upshift map is predetermined for each type of shift based on the accelerator operation amount Ac and the vehicle speed V, as indicated by the solid line in FIG. 9. As the accelerator operation amount Ac decreases, the vehicle speed V increases. It is designed to upshift to the high speed stage. Upshift 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 to determine whether to perform an upshift. That is,
If V ≦ Vu, there is no need to perform an upshift, it is determined in step SA8 whether or not the current gear is 1st. If it is 1st, there is no need to perform downshift determination, so step SA28 in FIG. Do the following,
If V> Vu, in step SA11, a gear position higher than the current gear position is set as the next gear position. In this case, even if the current gear position is, for example, 2nd, the accelerator operation amount Ac rapidly decreases before the gear position is switched to 3rd after the gearshift to 3rd is determined. If it exceeds the “3 → O / D” upshift line, the O / D shift speed is set. In step SA6, the shift-up vehicle speeds Vu for all the upshift lines are obtained from the current accelerator operation amount Ac. Do it.

If the judgment in step SA4 is YES, if the judgment in step SA5 is YES, or if the judgment in step SA8 is NO, step SA9 and subsequent steps are executed to judge whether or not to perform a downshift. I do. In step SA9, a predetermined downshift map is searched to determine a downshift vehicle speed Vd. The downshift map is determined in advance for each type of shift based on the accelerator operation amount Ac and the vehicle speed V, as indicated by the broken line in FIG. 9. As the accelerator operation amount Ac increases, the vehicle speed V decreases. The gear shifts down to the lower gear. Downshift vehicle speed Vd is determined according to the downshift map based on the accelerator operation amount Ac, in the next step SA10, the current corresponding to the output shaft rotation speed N _O vehicle speed V and the downshift vehicle speed V
Then, it is determined whether or not downshifting is to be performed.
That is, if V> Vd, there is no need to perform a downshift, and the process from step SA28 in FIG. 7 is executed.
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, for example,
If the accelerator operation amount Ac suddenly increases after the shift determination to 3rd is made and before the gear shift to 3rd is actually performed, and the speed exceeds the “2 ← 3” downshift line, , The second shift speed is set. Step SA9
In step SA, the downshift vehicle speed Vd for all downshift lines is obtained from the current accelerator operation amount Ac.
In step 10, the downshift is determined by comparing each of the downshift vehicle speeds Vd with the current vehicle speed V.

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 the case of the "S" range, steps SA14 and SA
At 15, the current gear is set to O / D or 3 based on the output state of the excitation signal for exciting the solenoids S1, S2 and S3.
rd, and whether 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 or not 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. In step SA20, 1st is set as the next shift speed. If it is not 2nd, that is, if it is currently the first shift speed, step SA21 is executed following step SA17, and FIG.
From the "1 → 2" upshift line, the shift-up vehicle speed Vu is determined based on the current accelerator operation amount Ac. In step SA22, it is determined whether the current vehicle speed V is equal to or lower than the shift-up vehicle speed Vu, and V> Vu. If so, in step SA16, 2nd is set as the next shift speed.

If the current range is not the "S" range, step SA23 is executed following 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, and SA26 whether or not the current gear is O / D, 3rd, or 2nd, and if it is O / D, 3rd, or 2nd. Is set to 1s as the next gear in step SA27.
Set t.

Steps SA8, SA10, SA1
9. If the determination in SA22 is YES, or step SA26
If the determination is NO, that is, if the current gear position is to be maintained, subsequently, step SA28 in FIG. 7 is executed to set the flags F1 and F2 to “0”,
At step SA29, an excitation signal of the solenoid is output so as to maintain the current gear position. Step SA1
When the next gear position is set in 1, SA16, SA20, or SA27, the process proceeds to step SA in FIG.
Step 12 is executed to set the shift timing time T1. This shift timing time T1 is a delay time from when the shift is determined to when the shift output is performed to actually switch the shift stage (step SA34 in FIG. 7), and the shift at a plurality of stages is performed in a short time. This is provided to prevent (multiple shifts), and a fixed value may be set in advance, but the type of shift such as upshift or downshift, or from which shift stage to which shift stage May be set differently in accordance with the conditions. Further, the accelerator operation amount Ac and the vehicle speed V at the time of the shift determination are determined.
It can also be set by a map, an arithmetic expression or the like according to the gear position.

When the shift timing time T1 is set in step SA12, the process proceeds to step SA3 in FIG.
Execute 0. In step SA30, it is determined whether or not the flag F1 is "0". If F1 is not "0", steps SA32 and thereafter are executed. If F1 = 0, the timer Ta is reset in step SA31. , And executes Step SA32 to set the flag F1 to “1”. Since the flag F1 is set to "0" in step SA28 executed when the current gear position is maintained,
In the first cycle in which the next gear is set, the value is "0", and the timer Ta measures the elapsed time after the next gear is set.

In the next step SA33, it is determined whether or not the time counted by the timer Ta has passed the shift timing time T1.
An excitation signal is output from the solenoid for establishing the next shift speed set at 6, SA20, or SA27. In step SA35, it is determined from the output state of the excitation signal whether or not the next shift speed established by the shift output in step SA34 is a low speed stage in which the engine brake operates. If so, the flag F2 is set to "1" in step SA36; otherwise, the flag F2 is set to "0" in step SA37.
And The shift to the low speed stage where the engine brake acts is performed by, for example,
There is a shift from O / D to 3rd with the FF operation, a shift to 2nd or 1st with the shift lever switching operation from the D range to the S range or the L range, and the like.

Next, the throttle control shown in FIG. 8 will be described. First, at step SB1, it is determined whether or not the flag F3 is "1".
Execute B11, otherwise execute step SB2. In step SB11, it is determined whether or not the accelerator operation amount Ac is in an accelerator OFF state where the accelerator operation amount is about 5% or less. If the accelerator is in the OFF state, steps SB8 and subsequent steps are executed. After setting F3 to “0”, in step SB13, the throttle valve opening θ is controlled according to the accelerator operation amount Ac. In this throttle control,
Based on the accelerator operation amount Ac indicated by the accelerator operation amount signal SAc, a throttle valve opening TA (Ac) is obtained from a predetermined map or an arithmetic expression, and the throttle valve opening TA (Ac) is calculated as a target throttle valve opening. 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 feedback control or the like.
Represents the target throttle valve opening TA ^* , that is, TA (A
A throttle control signal DTA is output to the throttle valve 20 so that the throttle control signal DTA coincides with c).

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

At step SB4, the flag F3 is set to "1", whereby step SB11 is executed following 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, acting negatively and acting as a braking force) at the gear before the downshift. The throttle valve opening degree TA2 at which the substantially same or slightly smaller driving force, that is, the driving force at which the engine braking force is substantially the same or slightly larger, is obtained even at the shift stage after the downshift, for example, as shown in FIG.
Is calculated by map interpolation from a data map stored in advance as shown in FIG. The data map of FIG.
Based on data experimentally obtained in advance as shown in FIG. 11, a throttle valve opening at which the driving force becomes substantially equal before and after the shift is obtained for each type of shift and vehicle speed. The data in FIG. 11 indicates that, in a vehicle equipped with an engine having the output characteristics shown in FIG. 12, the shift stage of the automatic transmission 78 is O / D (total gear ratio = 2.8905),
Gear transmission efficiency 0.855, tire effective radius 0.30
In the case of 6 m, for example, when the vehicle speed is 80 km / h and the accelerator is off, the driving force is-
It is about 300N. For example, when downshifting from the O / D gear to the 3rd gear, in the data corresponding to FIG. 11 in the case of the 3rd gear, the above-mentioned driving force, that is, the driving force substantially equal to 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.
Throttle valve opening TA2 ₃₁ ~TA2 _3n during the shift are determined for each vehicle speed V ₁ ~V _n in this way, "3r
d → 2nd (S3 ON) "also throttle valve opening TA2 ₂₁ ~TA2 _2n during the shift are set in the same manner as described above with reference to driving force data of 2nd gear position. Although not shown, 2n at which the engine brake operates from the O / D shift stage
For other downshifts, such as a shift to the d shift stage or a shift from the 3rd shift stage to the first shift stage where the engine brake operates, the map is created by obtaining the throttle valve opening TA2 in the same manner as described above. . The throttle valve opening TA2 increases as the vehicle speed increases for the same type of shift, and for the same vehicle speed, the downshift on the low speed side becomes larger than the downshift on the high speed side.

In the following step SB6, a change timing time T2 of the throttle valve opening θ is set. The throttle valve opening change timing time T2 is determined in step S
This is a delay time from when the downshift transmission output is made in A34 to when the throttle valve 20 is opened and controlled, and at a timing when slipping occurs in the clutch C and the brake B on the high speed side which are released during the downshift. At the same time, the current engine speed NE and the oil temperature TH of the hydraulic control circuit 150 are increased so that the engine speed NE increases.
It is calculated by map interpolation from the data map of FIG. 13 set in advance by experiment, simulation, or the like using O as a parameter. In this case, the higher the oil temperature THO, the lower the viscosity resistance of the hydraulic oil, the shorter the time required for draining and applying, and the slippage occurs in the clutch C and the brake B on the high speed stage after the shift output is performed. Since the delay time before the start is shortened, the throttle valve opening degree change timing time T2 becomes smaller as the oil temperature THO becomes higher. Further, as the engine rotational speed NE increases, the delay time from opening the throttle valve 20 to the control and then actually raising the engine 10 to the rotational speed NE becomes longer. The value decreases as the speed NE increases.

Here, referring to FIG. 14 which is a time chart when downshifting from the O / D shift stage to the 3rd shift stage, 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 to release the brake B ₀ , which is a frictional engagement device of the O / D shift speed, which is released at the time of the O / D → 3rd downshift. The engagement oil pressure P _B0 is reduced, and the engagement oil pressure P _C0 of the clutch C ₀ , which is a friction engagement device at the 3rd shift stage, engaged at the time of the O / D → 3rd downshift is increased. The time t2 is equal to the engagement hydraulic pressure P.
_The time at which the brake B ₀ starts to slip due to the decrease in B ₀ , and the time t 4 corresponds to the time when the throttle valve 20 is in the fully closed state corresponding to the accelerator operation amount Ac by the torque transmission of the clutch C ₀ . By transmitting the torque to the engine 10 side, the engine rotational speed NE is increased as shown by the solid line, and the rotational speeds of the output side and the input side of the automatic transmission 78 are changed to the gear ratio after the downshift. is the time clutch C ₀ has been completely engaged by synchronizing in accordance with the time from the time t2 to t4 (t4-t2) is the shift time.

In this embodiment, the shift time is shortened by temporarily opening the throttle valve 20 and increasing the engine speed NE during the shift, but before the time t2 or before the time t4. When the engine speed NE increases later, 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 rotational speed must be at least between the time t2 and t4. It is necessary to determine the throttle valve opening change timing time T2 so that the speed NE increases. In this case, the delay time from the solenoid output time t1 to the slip 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 increase in the engine speed NE is: Since it fluctuates depending on the engine speed NE, the change timing time T2 is set using these as parameters. That is, the oil temperature THO and the engine speed NE
Corresponds to the operating state of the vehicle which affects the engagement and release delay time of the friction engagement device and the increase delay time of the engine output, respectively. In the present embodiment, the frictional engagement device on the high speed side which is released at the time of the downshift, for example, O
FIG. 13 for determining the change timing time T2 so that the engine rotation speed NE starts to increase almost at the same time as the brake B ₀ starts to slip in the / D → 3rd downshift.
The map is defined. 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 in the first transmission 112.

In the next step SB7, the timer Tb is reset, and the elapsed time after the gearshift is output in step SA34 is measured. That is, this step SB7
In step SA34, the speed change output is made and step S
The process is executed for the first time when the flag F2 is set to "1" at A36, and in the subsequent cycles, the process proceeds to step SB.
Steps SB8 and subsequent steps are executed following Steps SB1 and SB11, so that the timer Tb measures the elapsed time after the start of the downshift transmission output. In step SB8, it is determined whether or not the counted content of the timer Tb has reached the change timing time T2.
Step SB1 until the change timing time T2 is reached.
In step 3, the throttle valve opening θ is controlled so that the throttle valve opening TA (Ac) corresponding to the accelerator operation amount Ac, that is, substantially fully closed. When the counted content of the timer Tb reaches the change timing time T2, it is determined in step SB9 whether or not the shift has ended based on whether or not the following equation (1) is satisfied. That is, when the shift output is performed in step S34 in FIG. 7 and the solenoids S1, S2, and S3 are switched between energized and de-energized, the clutch C and the brake B of the automatic transmission 78 begin to slip, and the turbine rotational speed N after _T and the output shaft rotational speed ratio of the rotational speed N _O speed change, that is, the shift is completed by substantially coincides with the gear ratio i of the current speed after the shift output, the rotational speed N _T of it such as, N _{When O 1} and the gear ratio i of the current gear stage satisfy the following equation (1), the gear shift has been completed. Incidentally, according equation (1), the rotational speed N _T, taking into account the detection error of N _O are determined so as to satisfy with a predetermined width.

[0035]

N _T ＮN _O × i (1)

The determination in step SB9 is YE
Until S, until the shift is completed in other words, the throttle valve opening TA2 is set to the target throttle valve opening TA ^* in step SB 10, the throttle of the throttle command signal SQ indicating the target throttle valve opening TA ^* The output to the control computer 35 controls the actual throttle valve opening θ of the throttle valve 20 to be the throttle valve opening TA2.

As described above, in the present embodiment, when the downshift is performed by manual operation of the overdrive switch 74 or the shift lever in order to increase the engine braking force, substantially the same drive is performed after the downshift as before the downshift. Since the throttle valve 20 is controlled to be opened to the throttle valve opening degree TA2 at which the force is obtained, the engine rotation speed NE is quickly increased, the shift time is shortened, and the life of the friction materials of the clutch C and the brake B is improved. In particular, in this embodiment, the throttle valve 20 is controlled so as to open the throttle valve 20 so that the engine rotational speed NE increases in accordance with the timing at which the clutch C and the brake B on the high speed side released by the downshift begin to slip. Since the opening degree change timing time T2 is determined based on the oil temperature THO and the engine rotational speed NE, a shift in the engine blow-up timing due to these fluctuations is prevented, and the effect of shortening the shift time can be reliably obtained. At the same time, the deterioration of the driving feeling at the time of gear shifting due to an increase in driving torque and the like is suppressed. Further, since the throttle valve opening change timing time T2 is set so that the engine rotational speed NE starts increasing almost at the same time as the clutch C or the brake B of the high speed stage starts to slip, the shift time can be shortened most efficiently. is there. The graph indicated by the dashed line with respect to the rotational speed in FIG. 14 is that of the present embodiment, and the time t3 is the shift end time of the present embodiment.

The line oil pressure PL of the oil pressure control circuit 150 is generally controlled in accordance with the throttle valve opening θ. When the throttle valve 20 is controlled to open as described above, the line oil pressure PL is increased. The hydraulic pressure of the clutch C and the brake B is also increased.
The shift time is further shortened by rapidly and completely engaging the clutch C and the brake B on the low speed side. However, in that case, since a large shift shock is likely to occur,
In this embodiment, at the time of 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, of the series of signal processing performed by the transmission control computer 34, the part executing step SA34 corresponds to the shift output means, and the part executing step SB6 corresponds to the engine 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. Steps SB1, SB2, SB4, S
The part executing B7, SB8 and SA36 corresponds to the timing control means, and the part executing 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. In the following embodiment, when the "D" range is selected, the automatic engine brake control for automatically increasing the engine braking force by throttle control or downshift is performed. As shown in parentheses, the first shift speed and the second shift speed at which the engine brake operates are established by exciting the solenoid S3. In addition to the power pattern, the economy pattern, and the like, an "automatic engine braking pattern" for automatically increasing the engine braking force on a downhill or the like is provided as a traveling pattern that can be selected by the pattern select switch 70.

FIGS. 15 and 16 are flowcharts relating to the shift control of the automatic transmission 78, and FIGS. 17 to 19 are flowcharts relating to the throttle control, which are repeatedly executed with a cycle time of about 8 to 32 msec as in the above-described embodiment. You. Step S1 and subsequent steps in FIG. 15 are steps for determining whether or not to change the gear position of the automatic transmission 78, and are executed when Step S40 is NO, that is, when the flag F3 is not "1". Flag F3
FIG. 1 shows that the automatic engine brake control is executed when all the conditions of steps SS1 to SS5 of FIG. 17 are satisfied.
In step SS14 or SS19 of step S8, the value is set to "1". If any one of the conditions in steps SS1 to SS5 is not satisfied, the value is set to "0" in step SS6. This is executed in the case of normal shift control in which the control is not performed.

In step S1, it is determined based on the O / D signal SO whether or not a shift up to the O / D gear is possible, and the O / D signal SO is turned off, that is, the O / D gear is prohibited. If there is, the current O /
It is determined whether or not the gear is the D gear. The current gear position is determined by the output state of the excitation signal that excites the solenoids S1, S2, and S3. If the current gear position is the current O / D gear position,
After setting the flag F2 to "1" in step S14,
In step S15, "3rd" is set as the next shift speed. If the determination in step S1 is NO, that is, O / D
If the gear is permitted, or if the determination in step S1 is YES, the current gear is not the O / D gear, and the determination in step S2 is NO and the current gear is not 3rd, and step S
If the determination of No. 3 is NO, step S4 is subsequently executed. In step S4, it is determined whether or not the current shift speed is the O / D shift speed. If the current shift speed is not the O / D shift speed, in steps S5 and S6, the same as steps SA6 and SA7 in the above-described embodiment is performed. It is determined whether to perform an upshift. If the upshift is not performed, it is determined in step S8 whether or not the current gear is 1st. If it is 1st, the flag F1 is set to "0" in step S9, and a series of shift determinations is completed. However, when an upshift is to be performed, the flag F1 is set to "1" in step S7, and then in step S15, a 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 of No. 8 is NO, steps S10 and S1
In step 1, it is determined whether a downshift is to be performed in the same manner 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, and a series of shift determinations is ended. If the downshift is 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 step S40 is YES, that is, if the automatic engine brake control is being executed, step S41 is executed following step S40.
It is determined whether the flag F5 is "0". The flag F5 is
When the automatic engine brake control is executed with all the conditions of steps SS1 to SS5 in FIG. 17 satisfied and the brake is depressed, it is set to “1” in step SS23 in FIG. 18; otherwise, Step SS
6 or SS12, which is set to "0". If the flag F5 = 0, the step S42 is executed, and if the flag F5 = 1, the step S45 is executed. In step S45 executed when the brake is depressed, a predetermined downshift map during engine braking is searched to determine a downshift vehicle speed Ved during engine braking. The downshift map at the time of engine braking is determined in advance for each type of shift based on the accelerator operation amount Ac and the vehicle speed V, similarly to the normal downshift map shown by the broken line in FIG. However, the vehicle is shifted to a higher vehicle speed side than a normal downshift map, and the downshift is easy. Shift down vehicle speed Ved
Is determined according to downshift map at the time of engine braking based on the accelerator operation amount Ac, at the next step S46, compares the current vehicle speed V and the downshift vehicle speed Ved corresponding to an output shaft rotation speed N _O ,
It is determined whether to perform a downshift. That is, V>
If it is Ved, it is not necessary to perform a downshift, and in step S44, the flag F2 is set to "0", and the shift determination is terminated. In step S48, a shift speed lower than the current shift speed is set as the next shift speed. The gear stage set here is the one where the engine brake acts.
Are set in the parentheses.
In this case, even if the current gear is O / D, for example,
After the gearshift to 3rd is determined and before the gearshift to 3rd is actually performed, the vehicle speed V suddenly decreases to “2”.
← 3 ”When the vehicle goes beyond the downshift line, the second gear is set. In step S45, the downshift vehicle speeds Ved for all the downshift lines are obtained from the current accelerator operation amount Ac. In step S46, each downshift vehicle speed Ved is compared with the current vehicle speed V to determine the downshift shift. Do it.

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

When the next gear is set in step S15, S43 or S48, the gear shift timing time T1 is set in step S16.
This shift timing time T1 is a delay time from when the shift is determined to when the shift output is performed to actually switch the shift stage (step S30), and that a plurality of shifts are performed in a short time (multi-shift). ), And when the upshift to the O / D gear is made when the accelerator pedal is quickly released to apply the engine brake on the downhill, before the upshift is actually performed. When the accelerator operation amount Ac becomes substantially zero, it is provided to prohibit an upshift to the O / D shift speed.
A fixed value may be set in advance, but different times may be set according to the type of shift, such as upshift, downshift, or downshift in automatic engine brake control. Further, it may be set by a map, an arithmetic expression, or the like according to the accelerator operation amount Ac at the time of the shift determination, the vehicle speed V, the shift speed, and the like.

Next, the flow chart of FIG. 16 for actually changing the gear position 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 of FIG. 15. In step S20, it is determined whether or not the flag F1 is "1", that is, the upshift shift determination is performed. Is determined. If the flag F1 is "1", step S
Steps 21 and below are executed, but otherwise, 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 performed to increase the engine braking force. If the flag F4 is "1", the steps from step S21 are executed. Otherwise, step S32 is immediately executed, the timer Ta is reset, and the process ends.

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

In step S29, it is determined whether or not the time counted by the timer Ta is equal to or longer than the shift timing time T1. Step S20 and subsequent steps are repeated until the shift timing time T1 is reached. When the shift timing time T1 is reached, step S30 is executed, and the solenoids S1 and S1 are executed.
By switching between excitation and non-excitation of S2 and S3, the gear position of the automatic transmission 78 is switched to the next gear position set in step S15 or S43 or the 3rd gear position changed in step S27. After that, the flag F1 is set to "0" in step S31, the flag F4 is set to "0", and the timer Ta is reset in step S32.

Here, in step S6, O / D
Even if an upshift to the gear position is determined, step S
Until the gear is actually switched at 30,
That is, the shift timing time T after the shift is determined.
If all of the conditions of steps S21 to S26 including the accelerator OFF are satisfied before the time 1 has elapsed, the next shift speed is changed to 3rd. When the driver releases the accelerator, the actual shift to the O / D shift stage is prevented even if an upshift shift decision is made with a decrease in the accelerator operation amount Ac, and the O / D shift stage is prevented. The reduction of the engine braking force due to the shift to へ is satisfactorily avoided. For example, when the driver releases the accelerator in the state of point A in FIG.
Since the accelerator operation amount Ac becomes zero after crossing the "3" upshift line and the "3 → O / D" upshift line, a shift determination from 2nd to O / D is finally made in step S6, In step S15, the O / D shift speed is set as the next shift speed. If the accelerator operation amount Ac becomes zero before the shift timing time T1 elapses after the “2 → 3” upshift is determined, “ 3 → O / D ”
Even if the next gear shifts to O / D after crossing the upshift line, the next gear is changed to 3rd in step S27, so that the gear is not upshifted to the O / D gear.

Even if the accelerator is once turned off,
If the depressing operation is performed again before the shift timing time T1 is reached, the determination in step S25 is NO, and the next shift speed is set to the O / D set in step S15 in step S28. When the vehicle is depressed, since the driver does not need so much engine braking force, the driver may upshift to the O / D gear position. The determination of step S29 is inserted between steps S20 and S21, and the determination of step S21 and subsequent steps are executed based on the driving state after the shift timing time T1 has elapsed, so that the shift speed is switched. 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 is performed as set in step S15, but also in this case, since the driver does not need so much engine braking force, the O / There is no problem in upshifting to the D gear. In other words,
When the driver needs the engine braking force, the accelerator pedal may be quickly released, and when the driver desires coasting or the like that does not require much engine braking force, the accelerator pedal may be released slowly. It is good.

Next, the throttle control shown in FIGS. 17 to 19 will be described.
In step S5, the shift range, the running pattern, the vehicle speed V, and the accelerator operation amount Ac are determined in steps S21 to S21.
The same determination as in step S25 is performed, and if all the conditions are satisfied, the automatic engine brake control in step SS8 and subsequent steps is executed. The flag F5 is set to "0" and the 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 uses a throttle map opening TA ( Ac) is determined, and the throttle valve opening TA (Ac) is calculated as the target throttle valve opening TA.
^{* And} the target throttle valve opening TA
By outputting a throttle command signal SQ representing ^* to the throttle control computer 35, the throttle valve 2
The actual throttle valve opening θ 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”.
Is set to “0” in step SS6, and is “0” when step SS8 is first executed,
Subsequently, step SS10 is executed, and the vehicle speed V at that time is set 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.
And execute step SS9. 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), the process proceeds to step SS9 in FIG.
If V ≦ (Vm−Vf), step SS10 is executed again, the target vehicle speed Vm is changed to the current vehicle speed V, and then steps SS11 and below are executed.
The constant value Vf is determined by considering the change in the vehicle speed V due to the feedback control of the throttle valve opening θ in steps R2 and R4 in FIG. Although it does not become, the vehicle speed V
Is relatively large, the determination in step SS9 is NO, and the target vehicle speed Vm is determined to be changed in step SS10.

In step SS11 of FIG. 18, it is determined whether or not the brake is depressed based on the brake signal SB. If the brake is off, that is, if the depressing operation is not performed, steps SS12 and subsequent steps are executed. If the user steps on the brake to further decelerate, the determination in step SS11 is NO, and steps SS22 and SS23 are executed. Step SS2
In step 2, the target throttle valve opening TA ^{* is set} to 0 in order to increase the engine braking force, and a throttle command signal SQ indicating 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 in step S45 in FIG.
Make sure that: At the beginning of the automatic engine brake control, that is, in the first cycle in which the accelerator is turned off, the normal brake is turned off.
The determination in Step 11 becomes YES, and Step SS14 or S
In S19, the flag F3 is set to "1", and FIG.
In step S41, each step of engine braking after step S41 is executed.

Step SS executed when 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".
At 6, it is determined whether or not an upshift has been determined. If the flag F1 = 1, the flag F3 is set to "1" in step SS14, and then in step SS15, the same normal throttle control as in step SS7 is performed. If the upshift shift determination is not made, or if the upshift shift output is made and the flag F1 is set to “0” in step S31 of FIG. 16, the determination in step SS13 is NO. In step SS16, it is determined whether the flag F6 is "0". The flag F6 is set to “1” in step R8 in FIG. 19 when downshifting is performed to increase the engine braking force. If the flag F6 = 0, the flag F3 is already set to “1” in step SS17. 1 "
Is determined. When the flag F3 = 1,
In step SS18 whether or not during shifting, for example, the rotational speed N _T, N _O, and the speed ratio i of the current gear
Is determined based on whether or not the above expression (1) is satisfied.
When the expression (1) is satisfied, the gear is not being shifted, and when the expression (1) is not satisfied, the gear is being shifted.

If the determination in step SS18 is YES, that is, if the gear is not being shifted, the automatic engine brake throttle processing routine of step SS21 is executed. If the gear is being shifted, step SS20 is executed.
Also, in the first cycle of the automatic engine brake control, the flag F3 is not "1", and the determination in step SS17 is N
In the case of O, after setting the flag F3 to "1" in step SS19, step SS20 is executed, and the same normal throttle control as in step SS7 is performed.

In the automatic engine brake throttle processing routine of step SS21, the actual vehicle speed V
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. Is executed according to the flowchart of FIG. In step R1 of FIG. 19, the actual throttle valve opening θ represented by the throttle valve opening signal Sθ
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. 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 a throttle valve opening TA1 (%) for making the vehicle speed V substantially equal to the target vehicle speed Vm is calculated in accordance with an arithmetic expression of feedback control according to a 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 capable of maintaining the target vehicle speed Vm when traveling on flat ground, that is, the driving force in consideration of the running resistance becomes zero. Throttle valve opening TAm
(%) Is calculated by, for example, map interpolation from a previously stored data map shown in FIG. 21, and it is determined whether or not the throttle valve opening TA1 is smaller than the throttle valve opening TAm. The data map of FIG. 21 is obtained by obtaining the throttle valve opening at which the driving force matches the running resistance for each gear position and vehicle speed based on the driving force data shown in FIG. For example, when the vehicle speed is 80 km / h, the throttle valve opening degree TAm (%) is about 7.
Since it is 4 °, if this is converted to% with respect to 80 ° of the fully open state, it becomes (7.4 / 80) × 100 = 9.3. That is, in the data map of FIG. 21, the throttle valve opening TA at the vehicle speed of 80 km / h at the O / D shift stage
₄₅ is specifically 9.3%, and thus O /
Throttle valve opening degrees TA _{41 to} T at various vehicle speeds in D gear stage
_A47 is required. The throttle valve opening degrees TA _{31 to} TA ₃₇ , TA ₂₁ to TA ₂₇ , and TA ₁₁ to 3rd gear and 2nd gear and 1st gear where the engine brake operates are the same as in the case of the O / D gear. TA ₁₇
Is required. As is clear from the data in FIG. 11, the throttle valve opening TAm increases as the vehicle speed increases, and increases at lower speeds with a higher gear ratio at the same vehicle speed. The 2nd shift speed and the 1st shift speed in FIG. 21 are shift speeds when the engine brake is applied, that is, the solenoid S3 is turned on.

If TA1 <TAm, the throttle valve opening TA1 is set to the target throttle valve opening TA ^* in step R4.
By outputting a throttle command signal SQ representing A ^* to the throttle control computer 35, the actual throttle valve opening θ of the throttle valve 20 becomes equal to the throttle valve opening T.
A1 is controlled. These steps R2, R
The throttle valve opening θ is quickly controlled so that the vehicle speed V substantially matches the target vehicle speed Vm by repeatedly executing the steps 3 and R4, and the target vehicle speed Vm when the accelerator is OFF or the vehicle speed V due to the brake depression operation is reduced. As a result, the engine braking force at 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.
The feedback control of the throttle valve opening θ is performed so as to substantially match the vehicle speed V regardless of the change in the road surface gradient.
The engine braking force is increased or decreased so as to substantially match the target vehicle speed Vm, and when the gradient changes from a steep gradient to a gentle gradient, the vehicle speed V is prevented from being reduced against the driver's intention due to excessive application of the engine brake. You.

On the other hand, if TA1≥TAm, the determination in step R3 is NO, and in step R5, the throttle valve opening TAm is set to the target throttle valve opening TA ^* , and the target throttle valve opening TA ^* is expressed. By outputting the throttle command signal SQ to the throttle control computer 35, the throttle valve 20 is controlled so that the actual throttle valve opening θ becomes the throttle valve opening TAm. This is because the engine braking force is increased or decreased so that the vehicle speed V substantially matches the target vehicle speed Vm irrespective of the change in the road surface gradient as described above. Is opened and the vehicle speed V is maintained at the target vehicle speed Vm. However, in such an engine brake control, it is normal that the driver thinks that the vehicle speed V decreases on an uphill, 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 feedback control. As a result, the target vehicle speed Vm is maintained on a downhill or a flat ground, but on an uphill, the vehicle speed V becomes lower than the target vehicle speed Vm in accordance with the gradient, and 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 in step R1 becomes YES, and the steps from step R6 are executed. At step R6, it is determined whether or not the current vehicle speed V is higher than the target vehicle speed Vm.
For V ≦ Vm, i.e. when decelerating with engine braking effect due to full closing of the throttle valve 20, it is not necessary to perform a downshift, in the following step R7, the target throttle valve opening TA ^* 0 Is set. However, if the vehicle is accelerating beyond the target vehicle speed Vm, the flag F4 for instructing a downshift is set to "1" in step R8 to increase the engine braking force, 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 in FIG.
Is executed, and the flag F6 is set to "1", so that step SS24 and subsequent steps in FIG. 18 are executed. In step R9, based on the type of shift to be downshifted and the current vehicle speed V, a driving force that is substantially the same as or slightly smaller than the driving force before the shift, in other words, a driving force that causes the engine braking force to be substantially the same or slightly larger. Throttle valve opening TA that can be obtained even after shifting
2 is calculated from the data map shown in FIG. 10 by map interpolation in the same manner as in step SB5.
In step 10, the throttle valve opening change timing 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 on the basis of the time at which the shift output of the downshift is performed in the step S30 is applied to the clutch C and the brake B on the high speed side released by the downshift. Experiments and simulations are performed in advance using the current engine speed NE and the oil temperature THO of the hydraulic control circuit 150 as parameters so that the engine speed NE rises in accordance with the throttle valve opening TA2 in accordance with the timing at which slippage starts to occur. Calculated by map interpolation from the data map of FIG. 13 set as described above.

When the flag F6 is set to "1" in step R8, in the subsequent cycle, the step SS in FIG.
The determination at 16 is NO, and step SS24 is executed. In step SS24, it is determined whether or not a shift output for downshifting is performed in step S30 and the flag F4 is set to "0" in the next step S31, and the timer is set in step SS25 until F4 = 0. Tb is reset, and when F4 = 0, step SS26 and subsequent steps are executed. By resetting the timer Tb in step SS25, the timer Tb measures the elapsed time from when the flag F4 is set to “0”, in other words, when the downshift transmission output is performed, In step SS26, the timer T
It is determined whether or not the counted time of b is equal to or longer than the throttle valve opening change timing time T2. When the elapsed time of the timer Tb reaches the change timing time T2, the throttle valve opening TA2 is set to the target throttle valve opening TA ^* in step SS27, and the throttle command signal SQ representing the target throttle valve opening TA ^*. Is output to the throttle control computer 35 so that the actual throttle valve opening θ of the throttle valve 20 becomes the throttle valve opening TA2. Also, the next step SS
In 28, the (1) determines whether the shift has been completed from the formula based speed ratio of the current gear after the shift output of the downshift is made i, and the rotational speed N _T, the N _O ,
When the shift is completed, a flag F6 is set in step SS29.
Is set to “0”. As a result, in the subsequent cycle, step SS17 and subsequent steps are executed following step SS16.

As described above, in this embodiment, when a downshift is performed when the accelerator is turned off in order 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 materials of the clutch C and the brake B is improved. In particular, in the present embodiment, the engine rotational speed N is accurately adjusted in accordance with the timing at which the clutch C and the brake B on the high speed stage released by the downshift begin to slip.
Since the throttle valve opening degree change timing time T2 for opening and controlling the throttle valve 20 is determined based on the engine speed NE and the oil temperature THO so that E increases, the engine blow-up timing due to these fluctuations is determined. The shift is prevented, the effect of shortening the shift time can be reliably obtained, and the deterioration of the driving feeling due to the temporary increase of the driving torque is suppressed.

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

FIG. 22 shows a vehicle speed of 55 km / h on a downhill of 8% by the automatic engine brake control of this embodiment.
FIG. 9 is a time chart showing changes in the rotational speed, drive torque, and the like of each part when a downshift is performed from the third gear to the second gear at the time of, and the opening control of the throttle valve 20 is performed at an appropriate timing. The shift is completed in about 0.69 sec without increasing the driving torque. On the other hand, FIG.
Accelerator OFF when the opening timing of
Regardless of the state, the driving torque is temporarily increased as shown in the portion D, causing the driver to feel uncomfortable. FIG.
In the case where the timing of the opening control of the throttle valve 20 is late, the effect of shortening the shift time cannot be sufficiently obtained, and the braking torque temporarily increases during the shift due to the inertia of the engine 10 or the like, which is not always satisfactory. Driving feeling cannot be obtained.

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

For example, in the above embodiment, step SA34
Alternatively, the time at which the shift is output in step S30 is set as the measurement start time, and the elapsed time is measured by the timer Tb to control the timing of opening and controlling the throttle valve 20, but 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 by using the time when the shift is determined 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.

In the above-described embodiment, the map shown in FIG. 13 for obtaining the throttle valve opening change timing time T2 in step SB6 or step R10 corresponds to the frictional engagement device on the high speed stage which is released at the time of downshift. Although the engine speed NE is set to start increasing almost at the same time as the start of the slip, the engine output is increased at least from the start of the slip to the time of full engagement of the friction engagement device on the low speed side. It only has to be set.

In the above embodiment, the hydraulic control circuit 150
The throttle valve opening change timing time T2 is set based on the oil temperature THO and the engine rotation speed NE, but either one of them is used, or another parameter is used. The throttle valve opening change timing time T2 may be set.

In the above-described embodiment, the engine output is increased by controlling the opening of the throttle valve 20. However, an engine auxiliary such as an alternator is used, or the idle speed control valve 38 is opened and controlled. To increase the engine output.

In the above embodiment, the throttle valve opening θ
Has been described for a vehicle controlled by the throttle control computer 35, but the present invention is also applicable to a vehicle in which the throttle valve 20 is mechanically connected to an accelerator pedal and opened and closed. The configuration of the automatic transmission 78 and the number of shift stages can also be changed as appropriate.

In the above-described embodiment, the throttle valve opening degree TA at which the driving force before and after the gear shift becomes substantially the same based on the type of gear shift and the vehicle speed at the time of the downshift when the accelerator is OFF is described.
2 was set, but the crankshaft 118
In addition, the predetermined value ΔTA may be added in consideration of the inertia of the torque converter 110 or the like, or may be temporarily widened until the engine speed is increased. Regardless, a constant value may be set. Further, similarly to the throttle valve opening ATm, the throttle valve opening at which the driving force becomes 0 at the gear after the gear shift can be set to TA2. can do.

In the above embodiment, the accelerator operation amount Ac
The throttle valve 20 is controlled to be opened when the downshift is performed in a substantially complete accelerator OFF state of about 5% or less. However, even if the accelerator is not in the complete OFF state, the engine having a negative driving torque is controlled. When braking,
The effect of the present invention can be obtained by controlling the opening of the throttle valve 20. Whether the drive torque is negative or not can be detected, for example, by comparing the engine rotation speed NE with the turbine rotation speed _NT of the torque converter 110.

In the second embodiment, the automatic engine brake control in step SS8 and subsequent steps is executed on condition that the automatic engine brake pattern is selected by the pattern select switch 70. For example, when another driving pattern is selected, the automatic engine braking control may be performed, or the automatic engine braking control may be performed regardless of the type of the driving pattern. Of course, a switch for engine brake control can be provided independently of the pattern select switch 70.

In the second embodiment, the conditions for performing the automatic engine brake control are as follows.
Although the vehicle speed limit of 4 is provided, such a vehicle speed limit is not necessarily required, and the range of the vehicle speed limit is appropriately determined. Another condition may be added as a condition for performing the automatic engine brake control.

Further, in the second embodiment, as the vehicle speed V decreases, step SS10 is executed each time the determination in step SS9 becomes NO, and the target vehicle speed Vm is sequentially changed according to the vehicle speed V at that time. However, step SS9 may be omitted, and the target vehicle speed Vm may be changed according to the vehicle speed V when the brake is released, or the target vehicle speed Vm may be sequentially updated based on the vehicle speed V when the brake is ON. Absent.

In the second embodiment, even if the next shift speed is changed to 3rd in step S27 in FIG. 16, if the accelerator pedal is operated before the shift timing time T1 is reached, the next shift speed is determined in step S28. Is returned to O / D, but if the next shift speed is changed to 3rd in step S27, step S30 may be executed immediately before the shift timing time T1 is reached to output the shift.

In the second embodiment, the accelerator is turned off.
The vehicle speed V at the time of release of the brake or when the brake is released is set to the target vehicle speed Vm as it is. However, the target vehicle speed Vm does not need to completely match the vehicle speed V. The 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 or decreased by a predetermined constant amount ΔTA. It is also possible to use other control methods, such as making the vehicle speed V not exceed the target vehicle speed Vm, or reducing the throttle valve opening θ by a fixed amount ΔTA. The constant value Vf of the step SS9 is determined 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 brake control such as controlling the engine braking force so that the acceleration becomes negative.

In the above-described embodiment, the engine control computer 32, the transmission control computer 34, and the throttle control computer 35 are formed separately, but they may be formed by a single computer. It is possible.

Although not specifically exemplified, the present invention can be embodied with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims 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 according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of the automatic transmission of FIG. 2;

FIG. 4 is a diagram showing shift speeds in each shift range in the embodiment of FIG. 2, the excitation of a solenoid for establishing the shift range, and the engaged state of a clutch and a brake.

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

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

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

FIG. 8 is a flowchart illustrating an operation of controlling the throttle valve opening of the engine of FIG. 2;

FIG. 9 is an example of a shift map for switching a shift speed of the automatic transmission of FIG. 2;

FIG. 10 is an example of a data map used when setting a throttle valve opening TA2 at which the driving force before and after the gear shift is substantially the same in step SB5 of FIG. 8;

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

FIG. 12 is data showing output characteristics of an engine used to obtain the basic data of FIG. 11;

FIG. 13 is an example of a data map used when setting the throttle valve opening change timing T2 in step SB6 of FIG. 8;

FIG. 14 shows the automatic transmission of FIG.
6 is a time chart showing changes in hydraulic pressure and rotational speed of each unit when downshifting to a shift speed.

FIG. 15 is a flowchart illustrating an operation of performing a shift determination as to whether or not to change the gear position of the automatic transmission according to another embodiment of the present invention.

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

FIG. 17 is a flowchart illustrating an operation of controlling the throttle valve opening of the engine in the embodiment of FIG. 15 together with FIG. 18;

FIG. 18 is a flowchart illustrating an operation of controlling the throttle valve opening of the engine in the embodiment of FIG. 15 together with FIG. 17;

FIG. 19 is a flowchart illustrating the contents of an automatic engine brake throttle processing routine of FIG. 18;

FIG. 20 is a diagram showing shift speeds in each shift range in the embodiment of FIG. 15 and excitation of a solenoid for establishing the shift ranges, and engagement states of clutches and brakes.

FIG. 21 is an example of a data map used for calculating a throttle valve opening TAm in step R3 of FIG. 19;

22 is a diagram showing a state where the gear ratio is changed from the third gear to the second gear in the embodiment of FIG.
6 is a time chart showing changes in the rotation speed, drive torque, and the like of each unit when a downshift is performed to an nd shift stage.

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

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

[Explanation of symbols]

10: Engine 20: throttle valve 34: Transmission control computer 35: throttle control computer 51: the rotational angle sensor 78: automatic transmission 86: oil temperature sensor 150: the hydraulic control circuit _{C 0, C 1, C 2} : clutch ( frictional engagement _{device) B 0, B 1, B} 2, B 3: brake (friction engagement device) Tb: timer T2: throttle valve opening change timing time steps SA34: shift output unit step 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 Step S31, SS24, SS25, SS26: Timing control means Step R9, SS27: Engine output increasing means Step R10 : Timing time setting means

Continuation of the front page (56) References JP-A-63-284039 (JP, A) JP-A-4-91332 (JP, A) JP-A-1-305138 (JP, A) JP-A-2-70934 (JP) JP-A-4-12139 (JP, A) JP-A-61-103044 (JP, A) JP-A-62-246650 (JP, A) JP-A-1-290931 (JP, A) 61-201957 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 29/00-29/06 B60K 41/00-41/28

Claims (1)

(57) [Claims] 1. An automatic transmission in which a plurality of shift speeds are established by changing an engagement state of a plurality of friction engagement devices by switching a hydraulic control circuit, and changing a shift speed of the automatic transmission. Transmission output means for switching the hydraulic control circuit to perform the operation, and engine output increasing means for increasing the engine output when the automatic transmission is downshifted to a low gear where the engine brake operates with the accelerator substantially in an OFF state. A shift control device for an automatic transmission, comprising: a timer for measuring an elapsed time from a measurement start time predetermined in relation to a switching time of the hydraulic control circuit by the shift output means during the downshift; After the frictional engagement device of the high speed stage that is released at the time of the downshift begins to slip, the low speed side that is engaged at the time of the downshift is engaged. Influencing at least one of the engagement and release delay time of the friction engagement device and the increase delay time of the engine output so that the engine rotational speed increases until the friction engagement device is completely engaged. Timing time setting means for setting a timing time until the engine output increase control is started by the engine output increase means based on the measurement start time based on the operation state of the vehicle; and an elapsed time measured by the timer A shift control device for an automatic transmission, wherein a timing control means for starting an engine output increasing control by the engine output increasing means when a timing time set by the timing time setting means has elapsed. .