JP2949154B2 - 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 apparatus for an automatic transmission and an engine, and more particularly, to an integrated apparatus for an automatic transmission and an engine that maintains good shift characteristics by changing an engine torque by a predetermined amount during shifting. It relates to a control device.

[Prior art]

A gear transmission mechanism and a plurality of friction engagement devices are provided, and the engagement of the friction engagement devices is selectively switched by operating a hydraulic control device. Automatic transmissions for vehicles configured to be achieved are already widely known. Such an automatic transmission for a vehicle generally includes a shift lever operated by a driver, a vehicle speed sensor for detecting a vehicle speed, and a throttle for detecting a throttle opening that is considered to reflect an engine load. And a sensor for automatically switching the engagement state of the friction engagement device in accordance with at least the vehicle speed and the throttle opening in accordance with the range of the shift lever. By the way, in the vehicle automatic transmission as described above,
Various integrated control of an automatic transmission and an engine have been proposed in which the engine torque is changed at the time of shifting to obtain good shifting characteristics and to secure and improve the durability of the friction engagement device (for example, Japanese Patent Application Laid-open No. 55-46095). In other words, this integrated control changes the amount of torque transmitted from the engine during gear shifting, and controls the amount of energy absorbed by each member of the automatic transmission or the frictional engagement device that brakes these members, thereby shortening the gearshift in a short time. The purpose of the present invention is to complete shifting by a shock, give a driver a good shifting feeling, and improve the durability of each friction engagement device. As described above, the shift control for controlling the engine torque at the time of shifting has been receiving attention as showing one direction in which the automatic transmission and the engine are integrally controlled, and are achieving corresponding results. By the way, if the engine torque is changed during gear shifting,
It is necessary to restore the changed engine torque at the end of the shift. Conventionally, regarding the return of the engine torque change, a change in the number of revolutions of the rotating member whose number of revolutions changes due to the shift is monitored, and immediately before the end of the shift is detected from the change in the number of revolutions of the rotating member, a predetermined time is detected. A technique has been proposed in which the engine torque is gradually restored over time, and this is currently considered to be the most accurate method (for example, JP-A-60-260749 and JP-A-59-97350).

[Problems to be solved by the invention]

However, engaging (or releasing) the friction engagement device
Inevitably, there is a variation in the hydraulic pressure at the time of this.
Further, it is unavoidable that the torque generated by the engine also varies within a certain range (even if the throttle opening is the same). As a result, the manner of change (rotational angular acceleration) of the rotation speed of the rotating member changes, and if the engine torque is gradually restored over a predetermined time immediately before the end of the shift, the completion of the return and the actual There is a problem that the end of the shift may not be synchronized. That is, if the completion of the return of the engine torque is delayed from the end of the actual shift, the output shaft torque drops in the transmission. Conversely, if the completion of the return of the engine torque is too early after the end of the shift, the engine torque is reduced. As a result, the effect of changing the gear ratio cannot be obtained sufficiently, and as a result, the amount of energy absorbed by the clutch increases and the durability decreases, or the shift shock increases. The present invention has been made in view of such a conventional problem, and always synchronizes the end of the shift and the completion of the return of the engine torque irrespective of the dispersion of the output of each automatic transmission or the engine. As a result, it is an object of the present invention to provide an automatic transmission and an integrated control device for an engine that can end a shift with a small shift shock and improve the durability of the friction engagement device.

[Means for Solving the Problems]

The present invention provides an automatic transmission and engine integrated control device which includes an engine torque changing means as shown in FIG. 1 and which changes the engine torque by a predetermined amount during a gear shift. Means for detecting the degree of rotation of the rotating member depending on the difference between the number of revolutions at the end of the shift and the current number of revolutions, and returning the engine torque to the means for shifting the engine torque based on the degree of progress of the shift. The means for instructing the start and the return amount of the engine torque after the start of the return are set such that the change amount of the engine torque becomes smaller as the difference amount approaches zero so that the return of the engine torque is completed in synchronization with the end of the shift. Means for successively changing and determining the value so as to approach zero, and achieving the above object by returning the engine torque based on the changed and determined return amount. It is.

Actions and effects of the present invention

In the present invention, when the engine torque is changed and then restored, the amount of return of the engine torque is determined by:
The change is sequentially changed in real time according to the degree of progress of the shift, and the completion of the return of the engine torque is completely synchronized with the end time of the shift. That is, conventionally, even if the timing and the degree of return of the engine torque change are determined in accordance with the degree of signal of the shift, after the return of the engine torque is started, regardless of the degree of progress of the shift after that, The engine torque was only gradually restored at the specified degree of restoration. As a result, the end of the shift and the completion of the return of the engine torque are not always synchronized due to the variation of the hydraulic pressure of the friction engagement device or the variation of the generated torque of the engine that occurs even with the same throttle opening. However, in the present invention, when the engine torque is returned, the amount of the return is sequentially changed in accordance with the progress degree of the shift that changes every moment. As a result, it is possible to always synchronize the completion of the return of the engine torque with the end of the shift regardless of the variation of the engagement hydraulic pressure of the friction engagement device or the variation of the engine torque. As a method of successively determining the amount of return of the engine torque according to the degree of progress of the shift, for example, when a turbine is considered as a rotating member, the turbine synchronous rotation speed (output shaft rotation speed N ₀ × depending on the difference amount .DELTA.N _T of the gear ratio i _h) as the current turbine speed N _T, Yuke increased in accordance with the return amount [Delta] T _E in reducing the difference amount .DELTA.N _T. In the present invention, "the return amount is sequentially changed and set according to the progress of the shift". However, for the purpose of the invention, "the change amount of the engine torque after the start of the return itself is successively changed according to the progress of the shift. Change / setting "as a matter of course.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is an overall schematic diagram of an automatic transmission combined with an electronic fuel injection engine for an automobile of a type that senses intake air, to which the present invention is applied. The air sucked from the air cleaner 10 is sequentially sent to an air flow meter 12, a throttle valve 14, a surge tank 16, and an intake manifold 18. This air is mixed with fuel injected from the injector 22 in the vicinity of the intake port 20, and is further sent to the fuel chamber 26A of the engine body 26 via the intake valve 24. Exhaust gas generated as a result of combustion of the air-fuel mixture in the combustion chamber 26A is released to the atmosphere via an exhaust valve 38, an exhaust port 30, an exhaust manifold 32, and an exhaust pipe 34. The air flow meter 12 is provided with an intake air temperature sensor 100 for detecting an intake air temperature. The electric throttle valve 14 rotates in conjunction with an accelerator pedal (not shown) provided in the driver's seat. The throttle valve 14 is provided with a throttle sensor 102 for detecting the degree of opening. A water temperature sensor 104 for detecting engine cold water temperature is provided in the cylinder block 26B of the engine main body 26, and a collecting portion of the exhaust manifold 32 is used to detect an oxygen concentration in the collecting portion. O ₂ sensor 10
6 are provided. Further, the distributor 38 having an axis rotated by the crankshaft of the engine body 26 is provided with a crank angle sensor 108 for detecting a crank angle from the rotation of the shaft. Also, automatic transmission A / T
Are provided with a vehicle speed sensor 100 for detecting the vehicle speed from the rotation speed of the output shaft, and a turbine speed sensor 112 for detecting the turbine rotation speed. Each of these sensors 100, 102, 104, 106, 108, 110, 11
The output of 2 is the engine computer (hereinafter referred to as ECU)
Entered in 40. The ECU 40 calculates the fuel injection amount using the input signal from each sensor as a parameter, and controls the injector 22 so as to inject the fuel for a predetermined time corresponding to the fuel injection amount. An idle rotation control valve (ISCV) 42 is provided in a circuit that connects the upstream of the throttle valve 14 with the surge tank 16, and the idle rotation speed is controlled by a signal from the ECU 40. I have. Further, the automatic transmission A / T has a pattern select switch 120 for selecting an E (economy) pattern for driving with emphasis on fuel efficiency and a P (power) pattern for driving with emphasis on power performance. Is provided, and the signal is input to the ECT computer 50. Also, E
In addition, signals from the brake lamp switch 122, the shift position switch 124, the overdrive switch 126, and the like are also input to the CT computer 50. As shown in detail in FIG. 3, the ECU 40 includes a central processing unit (CPU) 40A composed of a microprocessor and a memory 40 for storing control programs and various data.
B, an analog-to-digital converter (A / D converter) 40C having a multiplexer function for converting analog signals from the intake air temperature sensor 100, the water temperature sensor 104, etc. into digital signals and taking in the digital signals; Sensor 102, O
₂₎ An input interface circuit 40D for directly taking in outputs from the sensor 106, the crank angle sensor 108, the vehicle speed sensor 110, the turbine speed sensor 112, and the like, and the ignition coil 44 according to the calculation processing result of the CPU 40A. And an output interface circuit 40E for outputting a signal to the ECT computer 50 for the automatic transmission A / T, and an ignition signal to the injector 22, a fuel injection signal to the injector 22, an idle rotation control signal to the ISCV 42, and a signal to the ECT computer 50 for the automatic transmission A / T. Have been. On the other hand, the ECT computer 50 includes a central processing unit (CPU) 50A composed of a microprocessor, a memory 50B for storing a control program and various data, a throttle sensor 102, a vehicle speed sensor 110, and a turbine speed sensor.
112, a pattern select switch 120, a brake lamp switch 122, a shift position sensor switch 124, an input interface circuit 50D for inputting outputs from the overdrive switch 126, and an automatic processing in accordance with the arithmetic processing result of the CPU 50A. Transmission A / T solenoids S ₁ , S
_2, and an output Interferon chair circuit 50E for outputting a signal to the control signal and the ECU40 to S _3. Automatic transmission A / T, the solenoid S 2-3 shift valve 61 is by connexion driven to _1, the solenoid S 1-2 shift is by connexion driven _second valve 62 and 3-4 shift valve 63, the It includes a b look up class Tutsi control valve 64 which is by connexion driving the solenoid S _3, shift valve
The third speed unit for obtaining the first to third gear ratio configurations is controlled by 61 and 62, and the overdrive unit for obtaining the overdrive gear ratio is controlled by the shift valve 63. The lockup clutch control valve 64 controls the lockup clutch that mechanically directly connects the input and output sides of the torque converter. In addition, in the ECU 40, the reciprocal of the time interval of the signal for each crank angle 30 ° output from the crank angle sensor 108 is proportional to the engine rotational speed. Based on the calculation, the engine rotation speed is obtained. Further, the ECU 40 receives shift information (shift determination, shift command, lock-up clutch engagement permission, etc.) of the CET computer 50, executes engine torque down control, and outputs this control information to the ECT computer 50. ECT
Based on this information, the computer 50 issues a lockup clutch release command and checks whether or not the above control is being performed reliably. In this embodiment, the ECU 40 and the ECT computer 50 are separated, and the amount of engine torque reduction (the amount of return)
Although the ECU 40 determines and executes the timing, the present invention does not limit the number of control devices or the control sharing area thereof. FIG. 4 shows the relationship between various input / output devices while focusing on the functions of the ECU 40 and the ECT computer 50. The shift determination and shift output means 70 determines a shift according to the vehicle speed N ₀ and the throttle opening θ, and controls the solenoids S _{1 to} S _{3 and the} like. Further, the type of shift is transmitted to the engine torque reduction amount determining means 72. Inashiya phase start detecting means 74 and the engine torque reduction amount determination means 72, the vehicle speed N _0, depending on the turbine rotational speed N _T, and the throttle opening theta, to confirm the start time and change amount [Delta] T _E of the torque-down, the engine control the means 78 for example retarding the ignition timing to indicate a torque reduction by (retarding) etc. (described in detail in Figure 6 reference. after the change amount [Delta] T _E). The start of Inashiya phase (essentially a gear change period of the automatic transmission) is by connexion determined to _{N T <N 0 × i L} . Where i _L is
This is the gear ratio of the automatic transmission before shifting (at the low speed side). The engine torque return timing detection means 80 detects the establishment (end of shift) of _NT ≦ N ₀ × i _h + N ′ from the turbine rotation speed _NT , the vehicle speed N _0, etc., and determines this as the return start timing, It is transmitted to the engine torque return degree determination means 82. Here, i _h is a gear ratio after shifting (high-speed gear side), and N ′ is a constant determined by the throttle opening θ, the type of shifting, and the like (the sixth gear).
See figure. Detailed later). The engine torque return degree determination means 82 uses the torque down amount ΔT _E 'at the return start time and the constant N' to calculate the torque change amount ΔT _E by the following equation for each sample of N _T and N ₀ , for example. It calculates and instructs the engine control means. ΔT _E = ΔT _E ′ × (N _T −N ₀ × i _h ) / N ′ (1) Therefore, if the end of the shift is delayed, the torque return is also delayed, and if the shift is completed earlier, the return is also delayed. Since the timing is advanced, the shift end timing and the engine torque return completion timing can be completely synchronized. FIG. 5 is a flowchart of the above function. First, in step 201, a flag F for flow control is set.
Is confirmed. Since this flag F is initially set to zero, the flow proceeds to step 202. In step 202, it is determined whether or not an upshift shift determination has been made. If the upshift is not determined, it is reset as it is. That is, the engine torque change control according to the present invention is not particularly executed. If it is determined that the upshift has been determined, the routine proceeds to step 203, where it is determined whether the inertia phase has started. The start of the inertia phase is determined, as described above, as to whether or not the turbine rotational speed _NT has reached a point in time at which the vehicle speed N ₀ has become smaller than the value obtained by multiplying the vehicle speed N ₀ by the gear ratio i _L of the lower gear (previous gear). Is determined based on Unless N _T <N ₀ × i _L is satisfied, the routine proceeds to step 204, where the flag F is set to 1 and is reset. After that, the determination at step 203 is repeated via steps 201 and 205. If it is determined that the inertia phase has started, step 20
Only change amount [Delta] T _E of the engine torque proceed to 6 changes (down) to command is issued. Then go to step 207,
It is determined whether the shift has reached the end. This judgment is
As described above, it is determined whether or not _NT ≦ N ₀ × i _h + N ′ holds. FIG. 6 shows specific numerical examples of the torque down amount (retard amount) ΔT _E and the constant N ′. Torque reduction amount [Delta] T _E is Surotsutoru opening theta (engine load) is more increased larger setting. That is, as the throttle opening increases, the engine torque reduction amount ΔT _E
Is set large. Further, the torque reduction amount [Delta] T _E is
It is also changed depending on the type of shift, and qualitatively, the torque is reduced more greatly during the upshift on the lower gear side. On the other hand, the constant N 'is also set so as to increase as the throttle opening .theta. Increases, but the type of shift is maximized when shifting from the second speed to the third speed. Is set to This is because the level of the turbine rotational speed _NT and the amount of change in the engine torque in the type of the shift are considered. Until N _T ≦ N ₀ × i _h + N ′ is satisfied, the routine proceeds to step 208, where the flag F is set to 2. After resetting, the determination at step 207 is repeated via steps 201, 205, and 209. When it is determined in step 207 that the shift has reached the end, the process proceeds to step 210, where the return of the torque change is started. This return is performed based on the aforementioned equation (1). In the equation (1), _NT− N ₀ × i _h is the current turbine rotational speed _NT and the turbine synchronous rotational speed _NT ′ (=
N ₀ represents a × i _h) the difference between .DELTA.N _T. As is apparent from the determination formula in step 207, at the time of termination of the shift is detected, the difference .DELTA.N _T was found to be N '. Therefore,
_{(N T -N 0 × i h} ) / N ' is in the time shift end is detected in step 207 is 1, follow the N _T approaches N ₀ × i _h connexion, i.e. the shift end time As you approach, you will approach zero. Therefore, by multiplying the changing coefficient by the torque change amount ΔT _E 'at the time when the end of the shift is detected, the torque return (torque change) of the engine completely synchronized with the end of the shift is performed. It is possible to do. The relationship between the difference .DELTA.N _T between the torque change amount [Delta] T _E and the turbine speed N _T and the turbine speed N ₀ × i _h at shift end shown in Figure 7. As is clear from the figure, this torque change amount ΔT _E
It is one in which approaches to the slave go-between zero to the difference ΔN _T is close to zero accordance go-between, that is, the shift is going to end. The calculation in step 210 is performed for each sample of the turbine speed N _T and the vehicle speed N ₀ , and is instructed to the engine control means 78 side. In step 211, it is determined whether or not the shift is completely completed. This determination, N _T -N ₀ × i _h is whether Taka summer to zero, or, [Delta] T _E can be determined by connexion to detect Taka whether such decreased to zero. Before the shift is completed, the process proceeds to step 212, where the flag F is set to 3. After resetting, the process returns to just before step 210 via steps 201, 205, and 209, and the torque recovery of the engine is continued. If it is determined in step 211 that the shift has been completed, finally, in step 213, the flag F is set.
Is set to zero and reset again. FIG. 8 shows a shift transient characteristic when an upshift is performed using the above-described embodiment device. In the figure of the output shaft torque, it is assumed that the oil pressure of the friction engagement device is set to the characteristic shown by the solid line in order to obtain the torque characteristic shown by the solid line near the ideal torque characteristic shown by the dashed line.
A hydraulic pressure having such characteristics can be easily generated in a conventionally known hydraulic control device. In this case, the actual inertia phase starts at time point a in the figure, and is detected at point b. At the same time as this detection, the torque of the engine is reduced. Also, at point d, _NT ≦ N ₀ × i _h +
Since the condition of N 'is satisfied, the return of the engine torque is started, and the return is completed at the point f. In the prior art, the return time T ₀ has been so defined by the timer. For this reason, for example, when the oil pressure of the friction engagement device fluctuates to a higher value as indicated by the broken line, the torque return starts from the point c, and the rate of change of the turbine rotational speed _NT is changed.
Since dN _T / dt is large, the return completion time of the engine torque becomes e with respect to the actual shift end time d ′, and the output shaft torque drops as shown by the broken line.
Conversely, when the oil pressure of the friction engagement device varies to a low level (two-dot chain line), the progress of the shift is generally delayed, so that the torque return timing is determined at the point e, and the timer T ₀ 'elapses therefrom. At this point, the torque return has been completed. However, at point g, the hydraulic pressure of the friction engagement device has already been sufficiently low,
If the engine torque is restored at this stage, the absorption energy increases and the end of the shift is further extended.
As a result, the gear shift cannot be completed by the time of the return of the hydraulic pressure of the friction engagement device (point h), and a large shock occurs with the rise of the hydraulic pressure. In addition, the amount of energy absorbed by the friction engagement device increases as the engine torque is quickly restored, so that the durability is reduced. According to the above-described embodiment, the engine torque is restored in accordance with the degree to which the turbine rotation speed _NT approaches the synchronous rotation speed _NT ′ (= N ₀ × i _h ). Are always synchronized, good shift characteristics can be obtained, and the durability of the friction engagement device can be improved. The characteristic shown in FIG. 8 is based on an example in which the hydraulic pressure of the friction coupling device is controlled so as to gradually decrease during the speed change, but the more general hydraulic pressure slightly increases with time. The qualitative effect described above also applies to a hydraulic control device having such characteristics.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is an overall schematic view of an electronic fuel injection engine for a vehicle and an automatic transmission to which an embodiment of the present invention is applied, and FIG. FIG. 4 is a block diagram showing the relationship between the functions executed in the computer and the input / output devices. FIG. 5 is a block diagram showing the relationship between the functions executed in the computer and the input / output devices. flow diagram showing a control flow executed, FIG. 6 is a diagram showing a specific numerical example of a torque reduction amount [Delta] T _E and a constant N ', Fig. 7 shows the relationship between the difference .DELTA.N _T and the torque change amount [Delta] T _E FIG. 8 is a diagram showing various shift transient characteristics when an upshift is performed in the above embodiment. N _T … turbine speed, N ₀ … vehicle speed, i _L … gear ratio on the low speed side (front gear side), i _h … gear ratio on the high gear side (gear stage after shifting), N ': A constant used to detect the end of the shift (a constant used to detect the return timing of the engine torque), ΔT _E ': a torque change amount at the time when the end of the shift is detected, ΔT _{E: a} torque change amount.

Claims (1)

(57) [Claims] An integrated control device for an automatic transmission and an engine, comprising an engine torque changing means for changing an engine torque by a predetermined amount during a shift, wherein a degree of progress of the shift with respect to the end of the shift is determined when the shift of the rotary member is completed. Means for detecting the amount of difference between the number of revolutions and the current number of revolutions, means for instructing the means for changing the engine torque to start returning the engine torque based on the degree of progress of the shift, and The amount of return of the engine torque after the start is sequentially changed such that the amount of change in the engine torque approaches zero as the difference amount approaches zero so that the return of the engine torque is completed in synchronization with the end of the shift. An integrated control device for an automatic transmission and an engine, comprising: means for determining; and returning the engine torque based on the changed / determined return amount.