JP3317151B2 - Control device for vehicle equipped with engine and 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 control device for a vehicle equipped with an engine and an automatic transmission, and more particularly to a technique for temporarily increasing the engine output during a downshift period during deceleration driving.

[0002]

2. Description of the Related Art In a vehicle equipped with an engine whose output can be controlled independently of operation of an accelerator pedal and an automatic transmission in which a shift gear is automatically selected according to a running state of the vehicle, an accelerator pedal is used. When a downshift is performed during deceleration running of a vehicle that is not operated, the engine braking force is reduced by increasing the engine output in parallel with the downshift, thereby causing a shift shock during the downshift. A travel control device for a vehicle has been proposed in which the feeling of travel is alleviated to improve the travel feeling. For example,
This is the device described in Japanese Patent No. 284039.

[0003] By the way, in one type of the above-described travel control device, an engine output increase width is determined in accordance with the deceleration of the vehicle during deceleration traveling, and the engine output increase width is used in parallel with the downshift to use the engine output increase amount. Some increase the output. According to this, since the engine output increase width is reduced as the deceleration increases, there is an advantage that the downshift shock is suitably suppressed.

[0004]

However, in the case where the braking device is suddenly released during the above-described engine output increase period, the engine output increase width is calculated based on the deceleration and output. Since a certain response time is required until the shift is performed, a downshift shock may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to appropriately suppress a downshift shock even when the braking device is suddenly released during an engine output rise period. It is an object of the present invention to provide a control device for a vehicle that can perform the above.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide an engine in which idle speed is controlled and an automatic transmission in which a plurality of gears are selectively established. A vehicle having engine output increasing means for temporarily increasing the output of the engine during a downshift period during deceleration traveling, wherein: (a) braking for determining a release operation of the braking device of the vehicle; Releasing operation determining means; and (b) when the braking release operation determining means determines that the brake release operation of the vehicle has been performed by the engine output increasing means after the engine output increasing means has started increasing the engine output, the engine output increasing means determines the engine output. And an engine output increase range determining means for changing the increase range of the output to a larger value.

[0007]

In this way, after the engine output increasing operation is started by the engine output increasing means, if the braking release operation of the vehicle is judged by the brake release operation judging means, the engine output increasing width is increased. The deciding means changes the increasing range of the engine output by the engine output increasing means to a larger value. Therefore, even if the deceleration changes abruptly due to the brake release operation of the vehicle at the start of the engine output increase operation, the deceleration changes immediately .
Since the change width is changed to a larger increase width, the shock at the time of downshift is suitably suppressed.

[0008]

In another aspect of the present invention, preferably, the engine output increase width determining means determines an engine output increase amount by the engine output increasing means based on an actual vehicle deceleration from a preset relationship. , wherein when the release operation of the brake system of the vehicle is detected by the brake releasing operation determining means is for determining the engine output rise in value when the car both deceleration is minimal. With this configuration, when the vehicle that is traveling at a reduced speed due to the non-braking operation tends to slip rapidly, the engine output increase width is set to a large value, so that the downshift shock is suitably suppressed.

Preferably, (c) elapsed time counting means for counting an elapsed time after the engine output is temporarily increased by the engine output increasing means,
(D) Downshift determining means for determining the downshift when the elapsed time counted by the elapsed time counting means exceeds a predetermined reference time is further provided. According to this configuration, in a state where the engine output is increased by the engine output increasing width by the engine output increasing unit prior to the downshift of the decelerated traveling, the vehicle speed is lower than the shift point vehicle speed for the downshift. The inconvenience of being unable to downshift due to the difficulty of lowering is eliminated.

Preferably, (e) vehicle speed increase determining means for determining that a vehicle speed after the engine output is temporarily increased by the engine output increasing means has exceeded a preset value. (F) an increase stopping means for stopping an increase in engine output by the engine output increasing means when the vehicle speed increase determining means determines that the vehicle speed exceeds a preset value. . In this way, when the vehicle speed increases sharply, the engine output rise due to the engine output rise width suitable for the downshift during deceleration traveling becomes inappropriate, so that a downshift shock may occur instead. Since the increase of the engine output by the engine output raising means is stopped by the above-mentioned raising stop means, such a downshift shock is eliminated.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, 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 taken into the engine 10. The throttle valve opening .theta. Is controlled in accordance with a throttle control signal DTH 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.

The bypass passage 22 is connected to the throttle valve 20.
And the bypass passage 2
2 is provided with an idle speed control valve 38, and the opening degree of the idle speed control valve (ISC valve) 38 is controlled by the engine control computer 32, so that the air flowing through the throttle valve 20 is bypassed. The amount is adjusted to control the engine speed at idle. The injection timing and injection amount of the fuel injection valve 30 are also controlled by the engine control computer 32. In addition,
An intake air temperature sensor 40 for measuring the temperature of intake air is provided upstream of the air flow meter 16, and outputs a signal representing the intake air temperature to the engine control computer 32.

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 for measuring the temperature of the engine cooling water. The engine 10 outputs a signal representing the temperature of the engine cooling water to the computer 32 for engine control, and the exhaust manifold 54 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. The distributor 50 is provided with a rotation angle sensor 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 3.
2 and transmission control computer 34. Further, the operation state of the brake pedal 72, for example, the non-operation position (original position) and the operation position (depressed position)
Switch 74 for detecting the operation amount, an accelerator operation amount sensor 7 for detecting the operation amount Ac of an accelerator pedal (not shown)
6, a signal SB indicating the operation position of the brake pedal 72, the operation amount A of the accelerator pedal
c to the engine control computer 3
2. Output to the transmission control computer 34 and the throttle control computer 35.

Each of the engine control computer 32, transmission control computer 34, and throttle control computer 35 has a CPU, a RAM,
It is provided with an OM, an input / output interface circuit, an A / D converter, etc., and performs various controls by executing signal processing according to a program pre-stored in the ROM while utilizing the temporary storage function of the RAM. . For example, the engine control computer 32 executes combustion control of the engine 10, fuel cut control, idle rotation control, and the like. The transmission control computer 34 performs shift control for automatically switching the gear position of the automatic transmission 78 from the shift diagram shown in FIG. 2, for example. The throttle control computer 35 determines the throttle valve opening of a magnitude corresponding to the actual accelerator pedal operation amount Ac from a preset relationship, and illustrates the throttle valve 20 so that the throttle valve opening can be obtained. Drive using a throttle actuator that does not.

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 sun gear 124, a ring gear 126, and a planetary gear unit including a planetary gear 128 rotatably disposed on the carrier 122 and engaged 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 sun gears 131, 132, a pair of ring gears 134, 136, and carriers 138, 142 provided at both ends of the sleeve shaft 129, respectively. And a pair of planetary gears consisting of planetary gears 140 and 144 engaged with the first and second ring gears 134 and 136, respectively.
A clutch C is provided between the transmission 112 and the ring gear 126.
₁ is provided, the clutch C ₂ is provided between the sleeve shaft 129 and the ring gear 126, and the brake B ₁ represents between the sleeve shaft 129 and the housing 130, the one-way clutch F ₁ which are disposed in series And a brake B ₂ are provided in parallel, and a brake B ₃ and a one-way clutch F ₂ are provided in parallel between the carrier 142 and the housing 130. The carrier 138 and the ring gear 136 are integrally connected to an output shaft 146, and the output shaft 146 is connected to driving wheels via a differential gear device or the like.

[0019] 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 “○” in the column of solenoid means excitation, and the mark “○” in the column of clutch and brake means engagement. "D", "2",
"L" is the operating range of the shift lever in the driver's seat,
In the “D” range, shift control is performed in four steps from 1st to O / D, in the “2” range, shift control is performed in three steps from 1st to 3rd, and in the “L” range, two steps of 1st and 2nd are performed. The shift control is performed at the gear. The gear ratio (the rotation speed of the input shaft 120 / the rotation speed of the output shaft 146) is 1 s.
It is the largest at t, and decreases as 2nd, 3rd, O / D, and the speed ratio at 3rd is 1.0. Also,
The 4 → 3 downshift in the “D” range is executed by releasing the brake B ₀ and engaging the clutch C ₀ in power-off (deceleration) traveling, but in power-on (acceleration) traveling. This is executed when the brake B ₀ is released and the one-way clutch F ₀ is engaged. Although not shown, the shift lever is set to “R”.
When operated to the range, the manual shift valve of the hydraulic control circuit 150 is switched to establish the reverse gear.

The automatic transmission 78 has a pair of input shaft rotations.
A rotation speed sensor 80 and an output shaft rotation speed sensor 82 are provided.
Has been established. The input shaft rotation speed sensor 80 is a first transmission
112, the rotational speed of the sun gear 124, that is, the clutch C
₀Rotation speed N of housing _C0To detect the output
The shaft rotation speed sensor 82 detects the rotation speed NO of the output shaft 146.
The rotation speed N_C0, NO
Speed signal SN representing_C0, SNO transmission
Output to the control computer 34. Also, hydraulic control
A shift operation position detection switch 84 is provided in the circuit 150.
It is switched by operating the shift lever
From the position of the manual shift valve, "D",
Shift ranges such as “L” and “R” are detected and the shift
Transmits the shift range signal SR representing the
Output to the application control computer 34. Hydraulic control circuit
150 also has an oil temperature sensor for detecting the oil temperature THO of the hydraulic oil.
And an oil temperature signal S representing the oil temperature THO.
THO to transmission control computer 34
Output.

Each of the control computers 32, 34,
35, necessary information is mutually exchanged via a communication line, and the throttle valve opening signal S
θ, the engine speed signal SNE, and the accelerator operation amount signal SAc are stored in at least one of the control computers 3.
2, 34, or 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, and the exhaust temperature, are taken in to control the engine control and the automatic transmission 7.
8 can be used for the speed change control and the throttle control.

The engine control computer 32 calculates the intake air amount, the slot O valve opening θ, the engine rotation speed NE, the cooling water temperature of the engine 10, the intake air temperature, the oxygen concentration in the exhaust passage 56, 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,
0 controls the fuel gas injection amount and injection timing, and the igniter 48 ignition timing. The engine control computer 32 sets the actual coolant temperature of the engine 10 and the operating state of the auxiliary machine in a state where the operation amount Ac of the accelerator pedal is zero, such as during deceleration or stop, from a preset relationship. Is determined based on the target idle speed, and the opening of the idle speed control valve 38 is adjusted so that the actual engine speed NE matches the target idle speed.

Further, the transmission control computer 34 calculates the throttle valve opening θ or the accelerator operation amount Ac corresponding to the actual engine load and the output shaft of the automatic transmission 78 from a previously stored shift diagram shown in FIG. A shift is determined based on the rotational speed NO, that is, the vehicle speed V, and a shift output for realizing the determined shift is output to the solenoids S ₁ , S ₂ , and S ₃ to excite and de-energize them. Are controlled to switch the gear position of the automatic transmission 78.

The transmission control computer 34 also suppresses a shift shock when performing downshifting during engine braking or deceleration running with the accelerator operation amount Ac being substantially zero during downhill running or the like, that is, coast downshifting. In addition, in order to shorten the shift time while controlling, the throttle valve opening θ and the opening of the ISC valve 38 are controlled differently from the above. Hereinafter, the control related to the downshift during the engine brake traveling will be described.

FIG. 5 is a functional block diagram for explaining essential control functions of the engine control computer 32, the transmission control computer 34 and the like.
In FIG. 5, the shift control means 150 determines the actual engine load, that is, the throttle valve opening θ or the accelerator operation amount Ac, and the output shaft rotation speed NO of the automatic transmission 78, for example, from the previously stored shift diagram shown in FIG. A shift determination is performed based on the vehicle speed V, and shift outputs for realizing the determined shift are determined by solenoids S1, S2, and S.
3 to control switching of the gear position of the automatic transmission 78. The idling rotation control means 152 determines whether the operation amount Ac of the accelerator pedal is zero, such as during deceleration or stop, based on the actual cooling water temperature of the engine 10 and the operation state of the auxiliary equipment from a preset relationship. The target idle rotation speed is determined in accordance with the target idle rotation speed, and the opening degree v _ISC of the idle rotation speed control valve (ISC valve) 38 is output so that the actual engine rotation speed NE matches the target idle rotation speed.

The vehicle deceleration determining means 154 determines the rate of change of the output shaft rotation speed NO, that is, the vehicle deceleration Δ based on the output shaft rotation speed NO of the automatic transmission 78 input at a predetermined sampling period.
NO is determined sequentially. Input / output rotation speed ratio calculation means 156
Is calculated from the input shaft rotation speed NE and the output shaft rotation speed (the input shaft rotation speed of the automatic transmission 78, that is, the turbine rotation speed of the torque converter 110) NT of the torque converter 110 input at a predetermined sampling cycle. The input / output rotation speed ratio NE / NT of 110 is sequentially determined.

The engine output increase width determining means 158 determines the actual vehicle deceleration (a change amount of the output shaft rotational speed NO per unit time and a positive value based on a preset relationship shown in the data map of FIG. 6). ) The engine output increase width vdcst1 is determined based on ΔNO. This relationship is based on the characteristic that the engine output increase width vdcst1 decreases as the vehicle deceleration ΔNO increases in order to make the power transmission system in a weak drive state during the downshift period during deceleration traveling. The width determining means 158 determines the engine output increase width vdcst1 so as to decrease as the vehicle deceleration ΔNO increases. Further, the engine output increase width determining means 158 determines the engine output increase width vdcst1 based on the actual input / output rotation speed ratio NE / NT of the torque converter 110, for example, from a preset relationship shown in FIG. This relationship is expressed by the input / output rotation speed ratio N
As the E / NT increases, the engine output rise vdcst1
, In other words, the input / output rotational speed ratio NE /
Since the engine output increase width vdcst1 has the characteristic of increasing as NT decreases, the engine output increase width determining means 158 determines that the input / output rotation speed ratio NE / NT increases as the input / output rotation speed ratio NE / NT increases, in other words, the input / output speed increases. An engine output increase width vdcst1 that increases as the rotation speed ratio NE / NT decreases becomes determined. Here, the relationship shown in FIG. 6 indicates that at the time of a 4 → 3 downshift during deceleration running, at least the power transmission system from the engine 10 to the output shaft 146 of the automatic transmission 78 is in a weak drive state, that is, a slight positive torque drive state. Engine output increase width vdcst
It was obtained experimentally in advance to determine 1. The above-mentioned weak driving state, 4 → 3 predetermined value, for example, a few turns than the rotational speed of the clutch drum rotational speed NC ₀ or clutch C ₁ of the engine rotational speed NE is clutch C ₀ in the brake B ₀ upon release of the shift-down period by around upward by several tens of rotation to shock by engagement of the one-way clutch F ₀ it is meant the state is a size that does not cause a problem.

Further, the engine output rise width determining means 158 determines the actual operating oil temperature THO of the automatic transmission 78 detected by the oil temperature sensor 86 from a preset relationship shown in the data map of FIG. The engine output increase width vdcst2 is determined based on this. This relationship is such that as the hydraulic oil temperature THO increases, the engine output increase width vdcst2
In other words, the engine output increase width vdcst2 increases as the hydraulic oil temperature THO decreases.
Is such that as the hydraulic oil temperature THO increases,
In other words, the engine output increase width vdcst2 is determined so as to increase as the hydraulic oil temperature THO decreases. here,
The relationship shown in FIG. 7 indicates that, during a 4 → 3 downshift during deceleration running, the drainage time of the hydraulic oil from the brake B _O becomes longer, and the loss in the automatic transmission 78 increases, thereby reducing the engine speed NE. Against the tendency to lower,
This is experimentally obtained in advance to determine the engine output increase width vdcst2 so that the power transmission system is set to a weak drive state, that is, a slight positive torque drive state.

During the coast downshift, the engine output increasing means 160 increases the engine output increasing width vdcst determined by the engine output increasing width determining means 158.
(= Vdcst1 + vdcst2) by the idle rotation control means 1.
By adding the idling operation amount i.e. opening v _ISC of the ISC valve 38 determined by the 52, the engine output rise vdcst compared to normal idle state for the engine 1
The output amount of 0 is increased, and when it is determined that the downshift has been completed, it is terminated.

The engine output increasing means 160
Performs an output for temporarily increasing the engine output for a predetermined period earlier than the determination of the downshift during deceleration traveling or the start of the output. For example, as shown in the data map of FIG. 8, the output determination criterion determined based on the actual vehicle deceleration ΔNO from a preset relationship such that the output determination reference value KNO increases as the vehicle deceleration ΔNO increases. The value KNO is determined by, for example, a 4 → 3 downshift determination value of the automatic transmission 78 (from the 4 → 3 downshift line in FIG. 2, the actual accelerator pedal operation amount Ac and vehicle speed V or output shaft rotation speed N).
The shift point vehicle speed) NO ₄₃ defined by the O by adding the output determination reference value KNO value (NO ₄₃ + KNO), based on the actual vehicle speed V or the output shaft rotational speed NO falls below, 4 → 3 The output determination reference value K is more than the downshift determination
The engine output is temporarily increased earlier by NO.

The vehicle speed increase judging means 162 determines whether or not the vehicle speed has increased sharply after the engine output increasing means 160 starts increasing the engine output for downshifting during deceleration running, that is, the vehicle speed V is set in advance. It is determined whether or not the determined vehicle speed value V _IH has been exceeded. This judgment vehicle speed value V
_IH is a value for determining a sudden increase in vehicle speed, and a predetermined value is added to the vehicle speed V at the time when the engine output increasing means 160 starts increasing the engine output, or a predetermined ratio (for example, 10% Value).

If the vehicle speed increase determining means 162 determines that the vehicle speed V has exceeded a predetermined reference vehicle speed value _VIH , the ascending stop means 164 determines whether the engine output increasing means 160 has reduced the vehicle speed. The engine output for shifting is stopped from increasing, and the shift control means 1
50, the downshift output is stopped.

The elapsed time counting means 166, the elapsed time T _EL from the output of a command to temporarily increase the engine output, i.e., the actual shift point NO ₄₃ and the output criterion value of the vehicle speed V is deceleration downshift counting the elapsed time T _EL from when below the sum of the KNO. Downshift determining means 168, in a state in which the engine output than just an idle power engine output rise vdcst by the engine output increasing means 160 is raised, the elapsed time T _EL counted by the elapsed time counting means 166 in advance If the set reference time _TEL1 is exceeded, a downshift is determined.

The brake release operation determining means 170 determines the release operation of the brake system of the vehicle based on, for example, detecting a non-operation position of the brake pedal 72 or a decrease in brake fluid pressure using a well-known brake switch 74. judge.
The engine output increase width determination means 158 determines whether the vehicle is to be released by the brake release operation determination means 170 after the engine output increase operation of the engine output start means 160 is started. The increase width vdcst of the engine output determined based on the deceleration ΔNO, the input / output rotation speed ratio NE / NT, and the hydraulic oil temperature THO and output by the engine output increasing means 160
(= Vdcst1 + vdcst2) is changed to a different value, for example, a preset change value larger than that.
This change value is, for example, a value determined from the relationship in FIG. 6 when the vehicle deceleration ΔNO is the minimum value, that is, the value at the top of FIG.

FIG. 9 is a flow chart for explaining a main part of the control operation of the engine control computer 32, the transmission control computer 34, and the like, that is, the engine output increase control at the time of the coast down shift control. This control is repeatedly executed with a cycle time of about 8 to 32 msec. Also, the shift control means 1
Since the operations of the engine 50 and the idle rotation control means 152 are well known, their flowcharts are omitted.

At step SA1 in FIG. 9 (hereinafter, step is omitted), it is determined whether or not the content of the flag F1 is set to "1". When the content of the flag F1 is “1”, a downshift during deceleration running,
For example, this indicates that the control for increasing the engine output has been started at the time of the 4 → 3 shift.

Next, at SA2, it is determined whether a condition for starting the engine output increase control is satisfied. The start condition of the engine output increase control is satisfied, for example,
(1) The shift lever is operated to the D range,
(2) The automatic transmission 78 is in the fourth gear, (3) the output shaft rotational speed NO is a vehicle speed V higher than 1500 rpm, and (4) the deceleration ΔNO is 0 rpm or more. It means that the vehicle is running at a reduced speed, and (5) that the 4 → 3 downshift has not been completed.

If the determination at SA2 is negative,
After the content of the flag F1 is cleared to "0" in SA3 and the content of the timer T _COAST is cleared to "0" in SA4, this routine is terminated. This timer T _COAST is for counting the time elapsed from the output of the engine output increase for downshifting during deceleration running. However, if the determination at SA2 is affirmative, after the content of the flag F1 is set to "1" at SA5, the engine output increase width determining means 158 is set.
6 and FIG. 7, the actual deceleration ΔNO of the actual vehicle, the input / output rotational speed ratio NE / NT of the torque converter 110, and the temperature THO of the hydraulic oil of the automatic transmission 78 are obtained from SA6 corresponding to FIG. The engine output increase width vdcst (= vdcst1 + vdcst2) is determined based on.

Next, the brake release operation determining means 170
In SA7 corresponding to the above, it is determined based on the signal SB from the brake switch 74 whether or not the brake is in the ON state, that is, whether or not the brake is released by the brake pedal 72. When the brake is on, that is, when it is determined that the operation is not a brake release operation by the brake pedal 72, SA9 and the subsequent steps are directly executed, but when the brake is off, that is, when the brake pedal 7
When it is determined that the braking release operation is performed by the second control unit 2, the engine output increase width vdcst is larger than the value determined in SA6, for example, the deceleration ΔNO is determined in SA8 corresponding to the engine output increase width determination unit 158. When it is zero, it is changed to a value determined from the relationship of FIG.

Next, the engine output increasing means 160
In step SA9, the output determination reference value KNO determined based on the actual vehicle deceleration ΔNO from the preset relationship shown in FIG. the 4 → 3 4 → 3 shift determination vehicle speed) added value to NO _43, which is determined based on the actual output shaft rotational speed NO and the accelerator operation amount Ac from shift line (N
When the actual vehicle speed (output shaft rotation speed) NO falls below (O ₄₃ + KNO), the engine output increase width vdcst determined in SA6 or SA8 is reduced by the operation opening of the ISC valve 38 determined by the idle rotation control means 152. By adding the value to the degree v _ISC , the engine output is increased more than during normal idle rotation control. Time point t ₁ in FIG. 10 shows this state.

[0041] Subsequently, in SA10 corresponding to the elapsed time counting means 166, after "1" is added to the contents of the timer T _{COAS T,} in SA11, 4 → 3 actual vehicle speed down shift line high vehicle speed side It is determined whether or not a 4 → 3 downshift output condition, such as crossing to a lower vehicle speed side from, is satisfied. On the other hand, if the determination at SA11 is negative, the SA12 corresponding to the downshift determining means 168 is turned off.
In, whether the content of the timer T _{COAS T} reaches T ₄₃ preset determination reference time is determined.

At the beginning of this control, SA11 and S
Since any determination in A12 is denied, in SA13 corresponding to the vehicle speed increase determination means 162, it is determined whether or not the vehicle speed V exceeds a predetermined determination vehicle speed value _VIH . The determined vehicle speed value V _IH is a value for determining a sudden increase in the vehicle speed V, and a predetermined value is added to the vehicle speed V at the time when the engine output increasing means 160 starts increasing the engine output, or This is a value increased by a predetermined ratio (for example, about 10%).

In the normal case where there is no rapid increase in the vehicle speed at the time of the 4 → 3 coast downshift, the judgment at SA13 is denied, and the above SA1 and subsequent steps are repeatedly executed. As a result, the output increase of the predetermined width by the engine output increasing means 160 is maintained. Then, while the above steps are repeatedly performed, if the vehicle speed V is rapidly increased and the determination in SA13 is affirmed, the content of the flag F1 is cleared to "0" in SA14. As a result, in the next control cycle, the determination of SA1 is denied and the determination of SA2 is executed. However, when the vehicle speed V suddenly increases, any one of the engine output increase control start conditions, in particular, the deceleration ΔNO Since the condition that the vehicle is decelerating at 0 rpm or more is not satisfied, and the determination of SA2 is denied, the engine output increase control is stopped or terminated. The above SA14 is substantially equivalent to the ascent stop means 1.
64 is supported.

If the vehicle speed V does not increase rapidly after the increase in engine output is output by SA9,
The SA1 Although less is repeatedly executed, or determination is affirmative SA11 from shift diagram 4 → 3 downshift is determined, or the timer T _{CO AST} determination reference time contents have been preset T ₄₃ If the determination at SA12 is affirmative, the 4 → 3 shift output is performed at SA15, and the content of the flag F1 is cleared to “0” at SA16. T ₂ point in FIG. 10 shows this state.

After the output of the 4 → 3 shift is performed, while the steps of FIG. 9 are repeatedly executed, the speed ratio NT / NO of the automatic transmission 78 is the speed ratio of the third speed gear “1”. Is reached, the condition that the 4 → 3 downshift is not completed among the determinations of SA2 is not satisfied, and the determination of SA2 is denied, so that the engine output increase control is terminated. T ₃ time points in Figure 10 illustrates this state.

As described above, according to the present embodiment, after the engine output increasing means 160 (SA9) starts the operation of increasing the engine output, the braking release operation determining means 170 (S9)
When the brake release operation of the vehicle is determined in A7), the engine output increase width determining means 158 (SA8)
As a result, the increase in the engine output by the engine output increasing means 160 is changed to a larger value.
Therefore, even if the deceleration suddenly changes due to the brake release operation of the vehicle at the start of the engine output increase operation, the deceleration is immediately changed to a larger increase width, so that the shock at the time of the downshift is suitably suppressed.

In this embodiment, the engine output increase width determining means 158 determines the engine output increase width vdcst by the engine output increasing means 160 based on the actual vehicle deceleration ΔNO from the preset relationship shown in FIG. (= Vdc
st1 + vdcst2) to determine the braking release operation determining means 17
If the braking operation of the vehicle is detected by 0, the engine output increase width vdcst is set to a predetermined value, for example, a larger value than before, preferably, the vehicle deceleration ΔN
Since the value of O is determined to be the minimum value, when the vehicle decelerating due to the non-braking operation tends to slip rapidly, the engine output increase width is set to a large value. Shock is suitably suppressed.

In this embodiment, the elapsed time counting means 1 counts the elapsed time T _COAST after the engine output is temporarily increased by the engine output increasing means 160.
66 (SA10), exceeds the elapsed time T _{COAS T} is preset determination reference time T ₄₃ that has been counted by the elapsed time counting means 166, 4 → 3 downshift determining means 168 for determining the downshift (SA12 ) Are further provided. In this manner, in the state where the engine output is increased by the engine output increasing width vdcst by the engine output increasing means 160 prior to the 4 → 3 downshift of the deceleration running, the vehicle speed V is decreased by 4 → 3. The inconvenience of being unable to downshift because the vehicle speed is hardly lower than the shift point vehicle speed NO ₄₃ is solved.

In this embodiment, the vehicle speed increase determining means 162 for determining that the vehicle speed V after the engine output has been temporarily increased by the engine output increasing means 160 has exceeded a preset value _VIH. (SA13) If the vehicle speed increase determining means 162 determines that the vehicle speed V has exceeded the preset value V _IH , the increase stop means stops the increase in engine output by the engine output increase means 160. 164 (SA14). When the vehicle speed V sharply increases, an increase in engine output due to an increase in engine output suitable for downshifting during deceleration becomes improper. Thus, a downshift shock may occur instead. Since the increase in the engine output by the engine output increasing means 160 is stopped by the means 164, such a downshift shock is eliminated.

Further, in this embodiment, the engine output increase width vdcst1 is determined by the engine output increase width determining means 158 (SA6) based on the actual vehicle deceleration ΔNO from the preset relationship shown in FIG. The engine output increasing means 160 (SA9, SA10, SA12) increases the engine output by the engine output increasing width vdcst1 determined by the engine output increasing width determining means 158 during the 4 → 3 downshift period during deceleration running. . As a result, 4 →
Even when the vehicle speed at the time when the friction engagement device for the three-down shift operates varies, the increase in the engine output causes the power transmission system to operate at the timing when the friction engagement device for the four-to-three shift operation operates. Since the value is an appropriate value for the weak driving state, the shift shock is suitably prevented.

Further, in the present embodiment, the preset relationship of FIG. 6 used in the engine output increase width determining means 158 (SA6) is such that the engine output increase width vdcst1 increases as the vehicle deceleration ΔNO decreases. Therefore, as the deceleration ΔNO of the vehicle is smaller, the decrease in vehicle speed from the determination of the 4 → 3 downshift to the time when the friction engagement device for the 4 → 3 downshift is activated is smaller and the vehicle speed is higher. Therefore, at the timing when the friction engagement device for the downshift operates, the engine output is set to an appropriate value for bringing the power transmission system into a weak drive state.

Further, the vehicle of this embodiment is provided with a torque converter 110 which is a fluid type power transmission between the engine 10 and the automatic transmission 78, and the engine output increase width determining means 158 (SA6). Determines the engine output increase width vdcst1 based on the rotational speed ratio between the input shaft and the output shaft of the torque converter 110 (input shaft rotational speed NE / output shaft rotational speed NT) from a preset relationship shown in FIG. However, the relationship shown in FIG. 6 indicates that the engine output increase width vdcst1 becomes smaller as the rotational speed ratio NE / NT becomes smaller in order to make the power transmission system weakly driven during the 4 → 3 downshift period during deceleration traveling. Therefore, the more the rotational speeds of the input shaft and the output shaft of the torque converter 110 approach each other, the more the engine braking action becomes. In this state, the vehicle speed decreases from the determination of the 4 → 3 downshift to the time when the friction engagement device for the 4 → 3 downshift is activated, and the vehicle speed is high. At the timing when the engagement device operates, the engine output is set to an appropriate value for bringing the power transmission system into a weak drive state.

Further, in this embodiment, the engine output increase width determining means 158 (SA6) determines the engine output increase width vdcst2 based on the operating oil temperature THO of the automatic transmission 78 based on a preset relationship shown in FIG. Is determined. The relationship shown in FIG. 7 is that the engine output increase width vdcst2 is increased as the temperature THO of the hydraulic oil becomes lower in order to make the power transmission system weakly driven during the 4 → 3 downshift period during deceleration. It is. In order to achieve the 4 → 3 downshift, the outflow time of the hydraulic oil from the disengaged hydraulic friction engagement device increases due to a decrease in the temperature THO of the hydraulic oil, so that the downshift time tends to be delayed and at the same time the fluid transmission device The transmission loss of the engine 10 tends to increase and the rotational speed NE of the engine 10 tends to decrease. However, as described above, the engine output increase width vdcst2 is increased in association with the decrease in the operating oil temperature THO. In the downshift period during decelerating travel, a suitable weak drive state is set.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in other forms.

For example, in the above-described embodiment, in SA7 corresponding to the brake release operation determining means 170, the brake release operation is determined based on the release operation of the brake pedal 72 in the operating state. The determination may be based on the vehicle acceleration detected by the acceleration sensor.

Further, in the above-described embodiment, the example in which the control for temporarily increasing the engine output is applied to the 4 → 3 shift in deceleration traveling has been described, but the control is also applied to other downshifts. . In short, the accelerator pedal operation amount Ac
The downshift is achieved by the engagement of the one-way clutch in a relatively large power-on travel, but the downshift achieved by the engagement of the friction engagement device in the power-off travel in which the accelerator pedal operation amount Ac is substantially zero. You can change gears.

In the above-described embodiment, the engine output increase width vdcst is transmitted to the idle speed control means 152 by the ISC valve 3.
The engine output was temporarily increased during the 4 → 3 downshift period by adding to the operation opening degree v _{ISC of} 8; however, the engine output increase width is set to the target idle rotation speed in the idle rotation control means 152. vdcst
May be added.

In the above embodiment, for example, in FIG. 2, the accelerator pedal operation amount Ac is used as the value indicating the engine load, but the throttle valve opening θ, the intake air amount Q, the fuel injection amount, etc. are used. No problem.

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 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. Steps SA1 to SA
16 may be performed by the engine control computer 32.

Although not specifically exemplified, the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 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. 2 is a diagram showing a shift diagram used for controlling a gear position of the automatic transmission according to the embodiment of FIG. 1;

FIG. 3 is a diagram illustrating a configuration of the automatic transmission in FIG. 1;

FIG. 4 is a diagram illustrating a relationship between a shift speed of the automatic transmission of FIG. 3 and operating states of a solenoid, a clutch, and a brake for establishing the shift speed.

FIG. 5 is a functional block diagram illustrating a main part of a control function of the control device of FIG. 1;

FIG. 6 is a diagram showing a relationship used to determine an engine output increase range based on a vehicle deceleration in FIG. 5;

FIG. 7 is a diagram showing a relationship used in FIG. 5 for determining an engine output increase width based on a hydraulic oil temperature of the automatic transmission.

FIG. 8 is a diagram showing a relationship used to determine an output determination reference value based on a vehicle deceleration in FIG. 5;

FIG. 9 is a flowchart illustrating a main part of a control operation of the control device of FIG. 1;

FIG. 10 is a time chart illustrating the operation of the control device in FIG. 1;

[Explanation of symbols]

 10: Engine 78: Automatic transmission 158: Engine output increase width determination means 160: Engine output increase means 162: Vehicle speed increase determination means 164: Elevation stop means 166: Elapsed time counting means 168: Down shift determination means 170: Brake release operation Judgment means

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 29/02 341 F02D 29/02 341 41/04 301 41/04 301G F16H 61/04 F16H 61/04 // F16H 59:24 59:24 (56) References JP-A-5-338470 (JP, A) JP-A-5-214978 (JP, A) JP-A-61-104128 (JP, A) JP-A-10-18877 (JP, A A) JP-A-6-17673 (JP, A) JP-A-2-70955 (JP, A) JP-A-4-58021 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) F02D 29/00-29/06 B60K 41/00-41/28

Claims (4)

(57) [Claims] In a vehicle equipped with an engine whose idle rotation speed is controlled and an automatic transmission in which a plurality of gears can be selectively established, the output of the engine is temporarily reduced during a downshift period during deceleration driving. A brake release operation determining means for determining a release operation of a brake device of the vehicle; and a brake release operation after the engine output raising means starts to increase the engine output. when the brake release operation of the vehicle is determined by the operation determination means, a rise in the engine output by the engine output increasing means than before large
A control device for a vehicle equipped with an engine and an automatic transmission, comprising: an engine output increase range determining unit that changes the threshold value to a threshold value. 2. The engine output increase width determining means determines an engine output increase amount by the engine output increasing means based on an actual vehicle deceleration from a preset relationship, and the braking release operation determining means determines the engine output increase amount. 2. A control device for a vehicle equipped with an engine and an automatic transmission according to claim 1, wherein, when a release operation of a braking device of the vehicle is detected, the engine output increase width is determined to a preset value. 3. An elapsed time counting means for counting an elapsed time after the engine output is temporarily increased by the engine output increasing means, and an elapsed time counted by the elapsed time counting means is set in advance. And a downshift determining means for determining the downshift when the predetermined reference time is exceeded.
Control device provided with an engine and an automatic transmission. 4. A vehicle speed increase judging device for judging that a vehicle speed after the engine output is temporarily increased by the engine output increasing device has exceeded a preset value, and The engine according to any one of claims 1 to 3, further comprising a rise stop means for stopping a rise in engine output by said engine output rise means when it is determined that the vehicle speed exceeds a preset value. A control device for a vehicle including a transmission.