JPH0723069B2 - Integrated control method for automatic transmission and engine - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an integrated control method for an automatic transmission and an engine, and more particularly, to an improved integrated control method for an automatic transmission and an engine that maintains good gear shifting characteristics by changing engine torque during gear shifting. Regarding

[Prior art]

A gear shift 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. Vehicle automatic transmissions configured to be achieved are already widely known. Further, in such an automatic transmission for a vehicle, the engine torque is changed at the time of shifting to obtain a good shifting characteristic, and the automatic transmission and the engine which secure and improve the durability of the friction engagement device are integrated. Various control methods have been proposed (for example, Japanese Patent Application No. 59-234468). That is, such integrated control of the automatic transmission and the engine changes the amount of torque transmitted from the engine at the time of shifting to control the energy absorption amount in each member of the automatic transmission or in the friction engagement device that brakes these members. Then, the gear shifting is completed in a short time and with a small gear shifting shock, giving the driver a good feeling of gear shifting, and
The durability of the friction engagement device is improved. By the way, in order to always ensure good shifting characteristics obtained by reducing the engine torque over the entire area of each shift diagram, it is clearly specified when and how to reduce the engine torque. It must have been done. This is because, depending on how the engine torque is changed, a large gear shift shock may occur, which hinders a good gear shift feeling, or the gear shift time may be lengthened to improve the durability of the friction engagement device. It will worsen. In this regard, for example, in the above-mentioned Japanese Patent Application No. 59-234466, if the engine torque is changed during the so-called inertia phase (the period during which the rotating member of the automatic transmission changes the rotational speed for shifting), the engine will blow. It is disclosed that a shift characteristic with a small shift shock can be obtained without causing a rise. On the other hand, in addition to so-called engine load and vehicle speed, there is a technique for changing the engine torque change amount depending on factors that affect the engine output torque, such as the engine intake pressure (including the concept of supercharging pressure). For example, it is disclosed in Japanese Patent Application No. 60-237650. The purpose of this technology is to prevent variations in engine torque in the inertia phase and to prevent variations in gear shifting characteristics, and it is impossible to compensate the working force of the friction engagement device by feedback factors due to the influence factors of the engine output. It is a very effective means when controlling the engine torque in the automatic transmission control system of.

[Problems to be Solved by the Invention]

However, from the viewpoint of preventing variation in gear shift characteristics, that is, always ensuring good gear shift characteristics, it is difficult to say that the above-mentioned allowance is perfect. As is well known, this is because before and after the so-called inertia phase in which the rotating member of the automatic transmission changes the rotational speed for shifting, as is well known.
There is a period before and after the shift including a part called the torque phase, and engine torque fluctuations caused by fluctuations in intake pressure and intake temperature also affect the periods before and after the inertia phase. This is because the variation of the shift characteristics is fluctuated.

[Object of the Invention]

The present invention has been made in view of such a problem, and provides an integrated control method for an automatic transmission and an engine, which is capable of obtaining better gear shifting characteristics when performing torque change. The purpose is to

[Means for solving problems]

The present invention provides a procedure for detecting a gear shift determination or a gear shift command, and a gear shift determination or After the gear change command, the procedure for starting the change of the engine torque, the procedure for detecting the start of the inertia phase of the change from the change in the rotational speed of the rotating member, and the amount of change in the engine torque before the start of the inertia phase A step of changing the engine torque by an amount different from the above, a step of detecting the end of the inertia phase of the shift from a change in the rotation speed of the rotating member, and a step of returning the engine torque together with the detection of the end of the inertia phase. The above object has been achieved by.

[Action]

In the present invention, a procedure for determining a gear shift determination or a gear shift command, and starting the change of the engine torque after the gear shift determination or the gear shift command, and changing the engine torque by the amount of change after the start of the inertia phase. Since it is set to a value different from the above, and is restored at the end of the inertia phase, the effect of engine torque fluctuations can be almost completely eliminated, there is little variation, and therefore always good shifting characteristics. Will be able to secure. Preferably, the engine torque, engine intake temperature, engine intake pressure, engine cooling water temperature, engine oil temperature, oil temperature of the automatic transmission, and type of speed change are set as the change amount of the engine torque during the inertia phase and before the start of the inertia phase. , The vehicle speed and the shift pattern are set at least depending on one of them. As a result, it is possible to optimally absorb variations in each of the inertia phase and the preceding stage thereof, and it is possible to obtain better gear shifting characteristics. Further, preferably, the temporal change rate of the change amount at the time of changing the engine torque before the start of the inertia phase is calculated from among the engine load, the type of shift, the vehicle speed, and the shift pattern.
It depends on at least one setting. Before the start of the inertia phase, the change of the engine torque directly affects the fluctuation of the output shaft torque. Therefore, by setting the temporal change rate of the engine torque change at this time depending on these factors, it is possible to absorb the variation in the torque fluctuation and avoid the sudden change in the output shaft torque.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 2 is an overall schematic diagram of an automatic transmission (hereinafter referred to as ECT) combined with an intake air amount sensing type electronic fuel injection engine for an automobile to which the present invention is applied. The air sucked from the air cleaner 10 is sequentially sent to the air flow meter 12, the intake throttle valve 14, the surge tank 16, and the intake manifold 18. This air is mixed with fuel injected from the injector 22 near the intake port 20 and is further sent to the combustion 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 the exhaust valve 28, the exhaust port 30, the exhaust manifold 32 and the exhaust pipe (not shown). The air flow meter 12 is provided with an intake air temperature sensor 100 for detecting the intake air temperature. The intake throttle valve 14 rotates in conjunction with an accelerator pedal (not shown) provided in the driver's seat. The intake throttle valve 14 is provided with a throttle sensor 102 for detecting its opening. Also, the cylinder block of the engine body 26.
26B is provided with a water temperature sensor 104 for detecting the engine cooling water temperature. Further, a distributor having an axis rotated by the crankshaft of the engine body 26.
The crank angle sensor 108 for detecting the crank angle from the rotation of the shaft is provided at 38. Also, for ECT,
A vehicle speed sensor 110 for detecting the vehicle speed from the rotation speed of the output shaft, a shift position sensor 112 for detecting the shift position, and an oil temperature sensor 113 for detecting the oil temperature in the hydraulic control device 60 are provided. It is provided. Each of these sensors 100, 102, 104, 108, 110, 112, 113
Is output to the engine computer 40 or the ECT computer 50. In addition, the output of the atmospheric pressure sensor 122 that detects the atmospheric pressure is also input to the engine computer 40. The engine computer 40 calculates the fuel injection amount and the optimum ignition timing by using the input signal from each sensor as a parameter,
The injector 22 is controlled to inject fuel for a predetermined time corresponding to the fuel injection amount, and the ignition coil 44 is controlled to obtain the optimum ignition timing. In addition, the engine torque is reduced by retarding the ignition timing during shifting. An idle speed control valve 42 driven by a step motor is provided in the bypass passage that connects the upstream side of the intake throttle valve 14 and the surge tank 16, and an idle speed control valve 42 driven by a step motor is provided. The rotation speed is controlled. On the other hand, the transmission section 9 of the ECT in this embodiment.
00 is a torque converter 910 and an overdrive mechanism 9
20 and an underdrive mechanism 930. The torque converter 910 includes a pump 911 and a turbine 91.
2 and a stator 913, which is well known and includes a lockup clutch 914. The overdrive mechanism 920 includes a sun gear 921, a planetary pinion 922 that meshes with the sun gear 921, a carrier 923 that supports the planetary pinion 922, and a set of planetary gear units that include a ring gear 924 that meshes with the planetary pinion 922. Clutch the rotation state of the planetary gear unit.
It is controlled by C ₀ , brake B ₀ , and one-way clutch F ₀ . The underdrive mechanism 930 has a common sun gear 931,
Planetary pinion 932, 93 meshing with the sun gear 931
3, carrier 9 supporting the planetary pinion 932, 933
34, 935, two sets of planetary gear units consisting of ring gears 936, 937 meshing with planetary pinion 932, 933. The rotation state of this planetary gear unit and the state of connection with the overdrive mechanism are clutches C ₁ , C. _2, brake B ₁ ~B _3,
And, it is controlled by one-way clutches F ₁ and F ₂ . Since this transmission unit 900 is known per se, the connection state of each component is only shown as a skeleton in FIG. 2, and detailed description thereof will be omitted. The ECT in this embodiment includes the transmission section 900 as described above, and is a throttle sensor for detecting the intake throttle opening degree that reflects the load state of the engine body 26.
102, a vehicle speed sensor 110 for detecting a vehicle speed, and an ECT computer 50 to which signals such as a pattern select switch 114, an overdrive switch 116, a brake lamp switch 118, etc. have been input, and hydraulic control is performed in accordance with a preset shift pattern. The solenoid valves S _{1 to} S ₄ in the circuit 60 are driven and controlled,
As shown in FIG. 3, the engagement of the clutches, brakes, etc. is combined to perform the shift control. In FIG. 3, the mark ◯ indicates the operating state, and the mark ⊚ indicates the operating state only during driving. Although the engine computer 40 and the ECT computer 50 are separate bodies in this embodiment, the present invention does not limit the number of control devices or the control sharing region thereof. Next, the operation of this embodiment will be described. The engine torque control of the vehicle in this embodiment is executed according to the flow chart shown in FIG. First, in steps 202 to 212, the output shaft rotation speed (vehicle speed) N ₀ , the throttle opening θ, the intake air temperature Ta, the oil temperature To of the automatic transmission, and the atmospheric pressure Pa are read. F of step 214 is a flag for program control, which is initially set to zero. Therefore, step 218
To the throttle opening θ and the vehicle speed N _{0 in the same} manner as the conventional method.
Shift determination is made based on the above. If the result of this determination is that there is no gear change, the reset is performed as it is, but if it is that there is a gear change, the process proceeds to step 220 and the gear change is output. Further, in step 222, the ignition retard angle amount ΔBTDC ₁ is calculated as the vehicle speed N ₀ , the throttle opening θ, the intake air temperature Ta, the oil temperature To of automatic shift, the atmospheric pressure Pa, and the function f ₁ of the type of shift. . Specifically, as shown in FIG. 5, a basic retardation amount ΔBTDC ₀ preset according to the throttle opening θ, the type of shift, and the select position of the pattern select switch (economy pattern or power pattern). Is multiplied by an intake air temperature correction coefficient KTa, an atmospheric pressure correction coefficient KPa, and an oil temperature correction coefficient KTo as shown in FIGS. 6 (A) to (C), respectively,
Further, it can be obtained by multiplying the change amount ratio (about 0.3) with respect to the torque change amount in the inertia phase. It should be noted that, in FIG. 5, dividing the case into the economy pattern and the power pattern is equivalent to dividing into the case according to the vehicle speed N ₀ . Next, in step 224, N ₁ is obtained as the vehicle speed N ₀ , the throttle opening θ, and the function f ₂ of the type of shift. This N ₁
Is the ignition retardation amount ΔBTDC ₁ before the inertia phase.
When executing the torque change of the
It is a constant for determining the time required to change the torque by DC ₁ , that is, the time change rate of the torque change. As a typical example, the numerical value of N ₁ in the case of shifting from the first gear to the second gear is shown in FIG. At step 226, ΔBTDC ₁ is divided by N ₁ to obtain the retard change amount ΔBTDC ₁ ′ per routine. After that, in step 228, the ignition timing BTDC is replaced with a value obtained by subtracting the retard change amount ΔBTDC ₁ ′, and in step 230, n ₁ is incremented. The retard of the ignition timing is maintained at the time when n ₁ becomes N ₁ by step 232, that is, the ignition retard corresponding to the predetermined torque change amount in the pre-inertia phase is executed.
This maintenance is performed until it is determined in step 234 that the inertia phase has started. Whether or not the inertia phase has started is determined by, for example, monitoring the engine speed and detecting whether or not the engine speed this time becomes lower than the engine speed last time for several times. You can do it. When the inertia phase starts, proceed to step 236,
The ignition retard amount ΔBTDC ₂ in the inertia phase is obtained by the same method as that for obtaining the retard change amount ΔBTDC ₁ in the previous torque phase. However, since the change amount ratio of 0.3 is not multiplied, the result is slightly more than three times ΔBTDC ₁ . In step 238, the ignition timing in the inertia phase is reduced by the retard change amount ΔBTDC ₂ . This ignition timing retard is continued until it is detected in step 240 that the inertia phase has ended. Whether or not the inertia phase has ended is determined by, for example, detecting whether or not the engine rotation speed has reached a value obtained by adding a constant A to the value obtained by multiplying the output shaft rotation speed N ₀ by the gear ratio. You can When it is determined that the inertia phase has ended, step 24
In step 2, the ignition timing is restored, and in step 244, the flag F and the count n are reset. FIG. 7 shows a shift transient characteristic diagram. In the figure, the solid line is the standard characteristic. Good characteristics are obtained because the engine torque is reduced by detecting the inertia phase. On the other hand, when the engine intake air temperature decreases and the engine output increases, it becomes as shown by the broken line. Since the amount of torque reduction of the engine increases as the engine torque increases, the time of the inertia phase does not change much, but the hydraulic pressure level required to shift from the torque phase to the inertia phase increases, and in this figure, The transition from the torque phase to the inertia phase is performed only at the hydraulic pressure level P _B2 ′ when the accumulator starts. This is not preferable because of the following points. That is, assuming that the oil pressure varies to the low side (two-dot chain line in the figure), the transition from the torque phase to the inertia phase does not occur at the accumulator start oil pressure P _B2 ″, and then the oil pressure gradually rises in the buffer area of the accumulator. However, the inertia phase starts only when it becomes P _B2 ′. The vicinity of the start of the accumulator is the state where the energy absorption rate of the friction engagement device is the highest, and the above-mentioned characteristics show that the energy absorption amount is extremely high. In addition, due to the shift characteristic, the shift cannot be completed in the buffer region of the accumulator, and the output shaft torque is overshot. The engine torque is gradually decreased from the point (a), and the target engine torque is reached at the start of the inertia phase. Therefore, in the case of an engine with a supercharger, the intake air temperature, the oil temperature of the automatic transmission, and the supercharging pressure in addition to the atmospheric pressure are taken into consideration as correction factors. In this case, it is preferable that the higher the boost pressure, the larger the correction coefficient (the larger the retard amount).

【The invention's effect】

As described above, according to the present invention, the work of the friction engagement device during gear shifting can always be kept constant in the engine torque change control during gear shifting, regardless of the factors of various variations. As a result, the excellent effect that the engine torque can be changed as planned and accordingly the fluctuation of the output torque can be reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a flow chart showing a summary of an integrated control method for an automatic transmission and an engine according to the present invention, and FIG. 2 is combined with an intake air amount sensing type electronic fuel injection engine to which the present invention is applied. Sectional drawing which shows the whole structure of the Example of an automatic transmission including a partial block diagram, FIG. 3 is a diagram which shows the operating state of the friction engagement device in each gear stage of the said automatic transmission, 4th. The same figure is a flow chart showing the engine torque changing routine, FIG. 5 is a diagram showing an example of a map of ΔBTDC ₀ and N ₁ , and FIGS. 6 (A) to 6 (C) are intake air temperature, atmospheric pressure, automatic FIG. 7 is a diagram showing an example of a map when obtaining each correction coefficient of the oil temperature of the transmission, and FIG. 7 is a shift characteristic diagram for qualitatively explaining the effect of the above embodiment. 26 …… Engine body, 40 …… Engine computer, 50
…… ECT computer, 60 …… hydraulic control circuit, BTDC ……
Ignition timing, ΔBTDC ₁ …… Delay angle change amount before the start of the inertia phase, ΔBTDC ₂ …… Delay angle change amount in the inertia phase, N ₁ …… A constant for determining the time change rate of torque change.

Claims (3)

[Claims] Claim: What is claimed is: 1. An automatic transmission and engine integrated control method for maintaining good gear shifting characteristics by changing engine torque during gear shifting, a procedure for detecting gear shifting determination or gear shifting command, and gear shifting determination. Or, after the gear change command, the procedure for starting the change of the engine torque, the procedure for detecting the start of the inertia phase of the change from the change of the rotation speed of the rotating member, and the change of the engine torque before the start of the inertia phase after the start of the inertia phase Includes a procedure to change the engine torque by an amount different from the amount, a procedure to detect the end of the inertia phase of gear shift from the change in the rotation speed of the rotating member, and a procedure to recover the engine torque when the end of the inertia phase is detected. An integrated control method for an automatic transmission and an engine, comprising: 2. An engine load, an engine intake air temperature, an engine intake pressure, an engine cooling water temperature, an engine oil temperature, an oil temperature of an automatic transmission, and a gear shift, the change amount of the engine torque during the inertia phase and before the start of the inertia phase. 2. The integrated control method for an automatic transmission and an engine according to claim 1, wherein each of them is set depending on at least one of the type, the vehicle speed, and the shift pattern. 3. The time change rate of the amount of change when changing the engine torque before the start of the inertia phase is set depending on at least one of the engine load, the type of shift, the vehicle speed, and the shift pattern. An integrated control method for an automatic transmission and an engine according to claim 1 or 2.