JP2906264B2 - Integrated control device for automatic transmission and engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to an integrated control device for an automatic transmission and an engine configured to change an engine torque at the time of a shift and to reduce an engagement pressure of a friction engagement device related to the shift at the end of the shift.

[Prior art]

Hitherto, various integrated control of an automatic transmission and an engine have been proposed in which a good shift characteristic is obtained by actively changing an engine torque at the time of shifting, and the durability of a friction engagement device is secured and improved. JP-A-55-46095, JP-A-63-17130
etc). This integrated control changes the amount of torque transmitted from the engine during a shift transition, and controls the amount of energy absorbed by each member of the automatic transmission or the frictional engagement device that brakes these members, so that a short shift can be performed in a short time. The purpose of the present invention is to complete a shift by a shock, give a driver a good shift feeling, and improve the durability of each friction engagement device. By the way, a technique is disclosed in which the engagement pressure of the friction engagement device related to the shift is reduced at the end of the shift to reduce the shock when the engagement of the friction engagement device is completed. There is also disclosed a control in which the control for lowering the engagement pressure at the end of the shift and the control for changing the engine torque described above are related to each other and used together (Japanese Patent Laid-Open Publication No.
63-17130).

[Problems to be solved by the invention]

However, conventionally, when the control for changing the engine torque at the time of gear shifting and the control for lowering the engagement pressure are used together, only consideration is given to "associating the start of the reduction of the engagement pressure and the start of the return of the engine torque". However, the control is executed based on respective set values such as a decrease in engagement pressure by a constant amount by a constant, a torque recovery depending on a timer, and the like. Therefore, the process of decreasing the engagement pressure after the command to start the decrease of the engagement pressure and the process of returning the engine torque after the command to start the return of the engine torque are caused by various variations (for example, high and low intake air temperatures). The shift time does not match well due to variations in engine torque, friction coefficient of the friction material of the friction engagement device, or variations in the hydraulic pressure generated by the hydraulic control device. There is a problem that the characteristics may be deteriorated. SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and satisfactorily harmonizes the control for returning the engine torque with the control for lowering the engagement pressure. It is an object of the present invention to provide an integrated control device for an automatic transmission and an engine, which is capable of executing an automatic transmission.

[Means for Solving the Problems]

The present invention relates to an integrated control apparatus for an automatic transmission and an engine configured to change an engine torque at the time of a gear shift and to reduce an engagement pressure of a friction engagement device related to the gear shift at the end of the gear shift. Means for issuing a command so that the start of pressure reduction coincides with the start of the return of the engine torque; means for linearly reducing the engagement pressure after the command for the start of reduction of the engagement pressure; Means for returning the engine torque so that the rotational acceleration of the specific rotating member linearly changes after the command to start the return of the torque;
Means for completing the progress of the reduction of the engagement pressure and the return of the engine torque at the same time as the end of the shift, thereby achieving the above object.

[Action]

In the present invention, the start of the reduction of the engagement pressure and the start of the return of the engine torque simultaneously start to proceed. Further, the engagement pressure is decreased linearly after a decrease start command is issued. On the other hand, the return of engine torque
After the command to start the return of the engine torque is issued, the return is performed so that the rotational acceleration of the specific member linearly changes. As a result, the two controls proceed in harmony (while canceling each other out with respect to the fluctuation of the output shaft torque). Return is completed. As a result, fluctuations in the output shaft torque are prevented as much as possible. That is, ideally, the rotation speed of the rotating member changes so as to be convex downward. Therefore, if the engine torque is restored so that the rotational speed of the rotating member becomes linear, the return of the engine torque is convex upward. become. That is, not only does it return earlier to a decrease in the engagement pressure, but also the ability to correct for variations decreases. However, according to the present invention, since the engine torque is restored so that the rotational acceleration of the rotating member becomes linear, it is well matched with the decrease in the engagement pressure, and is excellent in the ability to correct variations.
This means that the shifting characteristics are better maintained.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 shows an overall outline of an automatic transmission for a vehicle to which this embodiment is applied. This automatic transmission has a torque converter 20 as a transmission unit thereof, a second transmission unit 40, three forward speeds,
And a first transmission section 60 of one reverse speed. The torque converter 20 includes a pump 21, a turbine 22,
It includes a stator 23 and a lock-up clutch 24. The pump 21 is connected to the crankshaft 10 of the engine 1, and the turbine 22 is connected to a carrier 41 of a planetary gear set in the second transmission section 40. In the second transmission section 40, a planetary pinion 42 rotatably supported by the carrier 41 meshes with a sun gear 43 and a ring gear 44. Also, sun gear
Between the 43 and the carrier 41, clutch C ₀ and has the one-way clutch F ₀ is provided between the sun gear 43 and the housing Hu, brake B ₀ is provided. The first transmission unit 60 is provided with two front and rear rows of planetary gear units. This planetary gear device has a common sun gear 61, ring gear 62, 6
3. It consists of planetary pinions 64 and 65 and carriers 66 and 67. A ring gear 44 of the second transmission unit 40 is connected to the ring gear 62 via the clutch C _1. Also, the clutch C ₂ is provided between the ring gear 44 and sun gear 61. Further, the carrier 66 is connected to the ring gear 63, and the carrier 66 and the ring gear 63 are connected to an output shaft 70. Meanwhile, the between the carrier 67 and the housing Hu is provided with a brake B ₃ and the one-way clutch F _2, further, between the sun gear 61 and the housing Hu, via a one-way clutch F ₁ Brake B ₂ is provided, also, between the sun gear 61 and the housing Hu, brake B ₁ is provided. The automatic transmission includes a transmission unit as described above, and receives an automatic signal from a throttle sensor 100 that detects a throttle opening degree reflecting a load state of the engine 1 and a vehicle speed sensor 102 that detects a vehicle speed. by the transmission control computer 104A, a hydraulic control circuit electromagnetic solenoid 106 valve S ₁ to S _4, proportional solenoid valve SB _0, and SB ₂ is driven and controlled according to a preset shift pattern shown in FIG. 3 The shift control is performed by performing such a combination of engagement of each clutch, brake and the like. It should be noted that the first transmission unit 60 is a second speed, a second transmission unit.
The gears that can be achieved with 40 high are cut for the purpose of reducing shift shock. In FIG. 3, the mark ○ indicates that the clutch or the brake is engaged, and the mark X indicates that the brake is engaged to apply the engine brake when the engine is driven from the wheel side. Is shown. As shown in FIG. 4, the electromagnetic solenoid valves S ₁ and S ₂ control first and second shift valves for controlling the first to third speed states of the first transmission 60. The electromagnetic solenoid valve S ₃ controls a third shift valve that switches between a high speed side and a low speed side of the second transmission unit 40, and the electromagnetic solenoid valve S ₄ controls a lock-up clutch 24 of the torque converter 20. Each is to do. Further, the solenoid proportional valve SB ₀ adjusts and controls the transient engagement pressure of the brake B ₀ according to the magnitude of the load current controlled by the central processing unit 104. Similarly, the electromagnetic proportional valve SB ₂ is summer so adjustable and controlled transient engagement pressure of the brake B _2. Adjustment of the engagement pressure of each solenoid proportional valve SB ₀ , SB ₂
Since the hardware structure of the control itself is the same as that of the related art, the description is omitted. In FIG. 1, reference numeral 110 denotes a shift position sensor which detects positions of N, D, R, etc. operated by a driver, and 112 denotes a pattern select switch.
E (economic running), P (power running), etc. are selected. Also, 114 denotes a water temperature sensor for detecting the temperature of the cooling water of the engine, 116 denotes a foot brake, and 118 detects the operation of a side brake. Each shows a brake switch. Here, in this embodiment, as shown in FIG. 2 and FIG. 4, in addition to these input signals to the central processing unit 104, C ₂ sensor for detecting the drum rotation speed of the clutch C ₂ It is the input signal of C ₀ sensor 121 for detecting the 120 signal and the drum rotational speed of the clutch C ₀ of together. The engine 1 controls the fuel injection amount and ignition timing of the engine 1 by an engine control computer 104B.
So that the signal SG ₁ indicating the automatic transmission control computer 104A to be reduced or returning the engine torque is input to 4B. The engine control computer 104B controls the engine ₁ based on the command from the automatic transmission control computer 104A based on the signal SG1 so that the engine torque is reduced or restored. It should be noted that a well-known configuration for changing the engine torque can be employed. For example, a method of delaying the ignition timing may be adopted, a configuration in which the throttle valve is closed may be adopted, or a configuration using these together may be adopted. Next, the operation of the above embodiment will be described with reference to FIGS. 1, 5 and 6. FIG. In FIG. 5, when a shift output is output in step 202, the process proceeds to step 204, where the value of the flag F is determined. This flag F is for determining the current state of the automatic transmission. Since the flag F is initially set to zero, the process proceeds to step 206. In step 206, it is determined by a known method whether or not the inertia phase has been entered (a period during which the rotating member of the automatic transmission changes the rotational speed for shifting). If it is determined that the inertia phase has been entered, step 208 is executed. Then, the value of the flag F is set to 1 and at step 210, the well-known feedback control of the engagement pressure and the engine torque-down control are started. In step 212, it is determined whether the conditions for starting the control for reducing the engagement pressure at the end of the shift and the conditions related to the control for returning the engine torque are correct. Specifically, this determination is made when the shift is a shift from the first speed to the second speed, and when the shift is a shift from the fourth speed to the fifth speed, the rotational speed C of the clutch C ₀ is determined. _c0 is determined by whether it is smaller than the constant Np _1, as shown in Figure 1 or Figure 6. When the type of the shift is a shift from the first speed to the third speed and a shift from the third speed to the fourth speed, the clutch C _0.
Of determining the rotational speed N _c0 is in whether it is less than plus constant Np ₁ to multiplied by the gear ratio i _H of the high-speed side to the output shaft rotational speed N _0. If it is determined that this condition is satisfied, the flow proceeds to step 214, where the flag F is set to 2, and first, in step 216, the engagement pressure reduction control at the end of the shift is started. In addition, this and t _p timer is started in step 218 at the same time. The t _p timer, considering that the return control of the engine torque is high responsiveness than the decrease control of the hydraulic and the start of the return of starting the engine torque of the hydraulic drop "substantially" in the shift end to match belongs to. As shown in step 220, the hydraulic pressure reduction control
The Δd calculated by _{α (D E -D N) /} Δt, determined a new duty ratio D by adding this Δd the duty ratio D _N at the present time, the electromagnetic proportional valve on the basis of the new duty ratio D Is controlled to reduce the hydraulic pressure. As shown in FIGS. 1 and 6, _DN is a duty ratio when the reduction of the engagement pressure is started, and _DE is a duty ratio when the reduction of the engagement pressure is completed. T _P timer in step 222 whether it is greater than the predetermined value T _P is determined, t _P timer is between less than a predetermined value T _P is advanced only reduction control of the engaging pressure. Eventually,
t _P timer recovery control of the engine torque is started the routine proceeds to step 224 when it is determined that greater than a predetermined value T _P, as shown at step 226, The engine torque is gradually restored to d ₁ represented by. Here, Np ₂ is a constant for determining immediately before the end of the gear shift, Np ₃ is the difference from the synchronous rotation speed (N ₀ × i _H ) at the time when the return of the engine torque is started, d _N
Indicates the amount of decrease in engine torque at the start of the engine torque return control (FIGS. 1 and 6).
See figure). Step 220 and is apparent from the equation 226, linear in this embodiment, reduction of the engaging pressure is a linear, whereas the return of the engine torque with respect to the square root of the rotation speed N _c0 rotary member (clutch C ₀₎ Each can be advanced. This is essentially the engagement pressure is linearly ideally, when you want to proceed to the return of the engine torque N _c0 acceleration (time rate) is linear, the complex calculation of the acceleration of the N _c0 In view of this, the engine torque is restored while being approximately proportional to the square root of _Nc0 . In practical use, it is possible to harmonize the reduction control of the hydraulic pressure and the progress of the return of the engine torque with almost no problem. In step 228, it is determined whether or not the end time of the return of the engine torque (the completion time of the decrease of the engagement pressure) has been reached. This determination is whether the kind of shift is when shifting from the first speed stage to the second speed stage, or from the fourth speed stage of the shift to the fifth speed stage, N _c0 is smaller than Np ₂ It is done by or. When the type of shift is a shift from the first speed to the third speed or a shift from the third speed to the fourth speed, N _c0 becomes smaller than N ₀ × i _H + Np _2. It is performed by determining whether or not it is. As a result, according to this embodiment, the decrease in the engagement pressure at the end of the shift and the return of the engine torque are started simultaneously, and the decrease in the hydraulic pressure is linear, and the return of the engine torque is advanced by a function of the square root of _Nc0. Since these controls are completed at the same time as the end of the shift, the member rotation speed N _c0
Becomes a quadratic function of time, so that the shift can be smoothly finished (the median value of the solid line in FIG. 1). If the oil pressure varies to the higher one (Fig. 1-dotted line),
The oil pressure decreases at a constant speed as in the case of the median value, and the return of the engine torque has an upward convex shape, and acts in the direction of decreasing the decreasing speed of the member rotational speed _Nc0 , that is, in the direction of extending the shift time.
On the other hand, when the oil pressure varies to the lower side (broken line in FIG. 1),
Since the oil pressure decreases at a constant speed and the return of the engine torque has a downward convex shape, it acts in a direction to increase the decreasing speed of the member rotation speed _Nc0 , that is, to shorten the shift time. Therefore, good correction characteristics can be obtained even for variations. In this embodiment, when the acceleration of the rotational speed N _c0 clutch C ₀ to return the engine torque is performed so as to vary linearly approximately the square root of N _c0 is so controlled to vary linearly However, it is within the scope of the present invention to apply the present invention by approximating a simple calculation formula without departing from the spirit of the present invention.

【The invention's effect】

As described above, according to the present invention, it is possible to perform the hydraulic pressure lowering control at the end of the shift and the control for restoring the engine torque (which has been reduced so far) in a completely synchronized (harmonic) state. An excellent effect is obtained that a shift with a small fluctuation of the output shaft torque, that is, a shift with a small shift shock can be executed.

[Brief description of the drawings]

FIG. 1 is a diagram showing shift transient characteristics when an embodiment of the present invention is implemented. FIG. 2 is a skeleton diagram of an automatic transmission for a vehicle to which the embodiment of the present invention is applied. Is a diagram showing an engagement state of the friction engagement device of the automatic transmission; FIG. 4 is a block diagram mainly showing an input signal system and an output system to a hydraulic control device; FIG. 6 is a flow chart showing a control flow executed by the apparatus of the embodiment, and FIG. 6 is a diagram showing a relationship between a duty ratio, a rotation speed of a member (clutch C ₀ ), and engine torque. 1 ...... engine, 40 ...... second transmission part unit, 60 first transmission unit ......, N _c0 ...... rotational speed of the clutch C _0, D ...... duty ratio, the amount of change [Delta] d ...... duty ratio, d ₁ … The amount of decrease in engine torque.

Continuation of the front page (56) References JP-A-63-17130 (JP, A) JP-A-55-46095 (JP, A) JP-A-62-221929 (JP, A) JP-A-63-254256 (JP, A) , A) JP-A-1-115738 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60K 41/00-41/28 F02D 29/00-29/06 F02D 41/00 -41/40 F16H 59/00-63/48

Claims (1)

(57) [Claims] 1. An integrated control apparatus for an automatic transmission and an engine, wherein an engine torque is changed during a gear shift and an engagement pressure of a friction engagement device related to the gear shift is reduced at the end of the gear shift. Means for issuing a command so that the start of the reduction of the combined pressure and the start of the return of the engine torque coincide with each other; a means for linearly reducing the engagement pressure after the command for the start of the reduction of the engagement pressure; Means for returning the engine torque so that the rotational acceleration of the specific rotating member changes linearly after the command to start the return of the engine torque; and An integrated control device for an automatic transmission and an engine, comprising: means for completing a return.