JPS61279760A - Method of controlling engine torque - Google Patents

Abstract

PURPOSE:To make it possible to satisfactorily control the torque of an engine of such a type that the engine torque is increased and decreased by predetermined amount during gear shift, by changing the above-mentioned predetermined value and a range in which the engine torque is controlled to be increased and decreased, when the temperature of exhaust gas exceeds a reference value. CONSTITUTION:The transmission section 900 of an automatic speed change gear (ECT) is subjected to the control of speed shift by an ECT computer 50 which controls a hydraulic control circuit 60 in accordance with signals from a throttle sensor 102, a vehicle speed sensor 110, etc. An engine receives the data of gear shift from a computer 50, and an engine computer 40 controls the engine torque so that it is increased and decreased by a predetermined values during gear shift. In the above-mentioned arrangement, during the engine torque being controlled, at least either one of a range in which the engine torque is controlled to be increased and decreased, and the increased and decreased values (predetermined values) of engine torque, is changed when the temperature of exhaust gas exceeds a reference value.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an engine torque control method, and more particularly to an improved engine torque control method that maintains good shift characteristics of an automatic transmission by increasing or decreasing engine torque by a predetermined amount during a shift. .

[Conventional technology]

! ! l l! '13! 'RII'F[(7)111
m1QilFlell・ :,. said friction by actuating a hydraulic control device.
:jl) Selectively switch the engagement of engagement I to shift multiple gears
Configure so that any of the steps L, , .
However, automatic transmissions for vehicles are already widely known.
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1. □゛[By changing the engine torque at high speed to obtain good shifting characteristics, rI! ! Various integrated control methods for an automatic transmission and an engine have been proposed that aim to ensure and improve the durability of the frictional engagement lA'/II. (For example, Japanese Patent Publication No. 55
-69738>. In other words, such integrated control of the automatic transmission and engine 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 friction engagement device that brakes them. Thus, the gear shift is completed in a short time and with a small shift shock, giving the driver a good shift feeling, and improving the durability of the friction engagement device.

Problem 2 to be Solved by the Invention 1 However, for example, if a method of delaying the ignition timing is adopted as a means of changing (reducing) engine torque, the delay in the ignition timing increases so-called afterburning, and the exhaust temperature decreases. The problem arises that . Also, depending on the type of gear shifting, the engine torque may be controlled to increase, but in this case, there are ways to change (increase) the engine torque, such as by changing the amount of fuel supply or intake air!
Even when a method of increasing the temperature is adopted, the exhaust temperature increases to -1t. In this way, the increase in exhaust temperature caused by changing the engine torque during gear shifting is not a problem at all if the gear shifting frequency is normal, but if the gear shifting frequency is high, it may occur when driving in mountainous areas or when the user intentionally turns on the accelerator. - If the engine is turned off, the exhaust temperature will rise above the allowable value, and in severe cases, it may cause cracks in the exhaust manifold or damage to the exhaust side turbine blades in turbocharged engines. Therefore, the design of routines for engine torque control,
When setting the engine torque change amount map, etc., it was necessary to take care to ensure that the exhaust temperature would not rise excessively even if gear shifts were performed at the highest possible frequency. However, from this point of view, for example, if the ignition timing is
If the angle amount is set to a small value, the amount of decrease in engine torque will naturally be reduced, resulting in frictional engagement S! A problem arises in that the original purpose of the control, which is to improve speed change characteristics including the durability of the system, may not be fully achieved. [Object of the Invention] The present invention has been made in view of such conventional problems, and it is an object of the present invention to increase the degree of freedom in setting engine torque control during gear shifting by eliminating at least the restriction on the rise in exhaust temperature. It is an object of the present invention to provide a method for controlling engine torque that allows the original function of engine torque control to be fully exerted.

[Means to solve the problem]

The present invention is an engine torque control method that maintains good gear shifting characteristics of an automatic transmission by increasing or decreasing engine torque by a predetermined amount during gear shifting, as shown in FIG. The procedure for detecting the exhaust temperature of the engine, and the increase/decrease in the engine torque when the exhaust temperature of the engine is higher than the reference value! The above object is achieved by including a procedure for changing at least one of the 1J-controlled real FM area and the predetermined amount. Further, in an embodiment of the present invention, the change in the implementation area depends on the throttle opening or the type of gear change.
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F, @JIS/JSmlC. This makes it possible to accurately prevent the exhaust gas temperature from rising while suppressing the rise in exhaust gas temperature.
1. Also, in an embodiment of the present invention, the reference value is tilted twice.
1' Hysteresis is provided when the change is started and when the change is canceled, and normal torque change control is performed after the exhaust temperature rise has subsided to a certain degree. This is how it was done. , llI, that is, in this embodiment, the exhaust temperature is 1□8□l, f%RIJ□ near the reference field.
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[Effect]

In the present invention, the exhaust gas temperature is actually detected, and the temperature is 1 degree above "Ef;'i+!"". Shift CtLk:
,,. Original line bh8″tX>’;>t′″/ ’! II i
O implementation area: loss and torque increase/decrease! As a result, there is no need to set limits to avoid problems caused by a rise in exhaust temperature when designing engine torque control routines or setting torque increase/decrease, etc., and there is a high degree of freedom. That is, it becomes possible to perform engine torque control that is more in line with the original purpose. (Example) Examples of the present invention will be described in detail below with reference to the drawings. FIG. 2 shows an automatic transmission m combined with an intake air amount sensing type automobile electronic fuel injection engine to which the present invention is applied.
<hereinafter referred to as ECT) is an overall schematic diagram. The air taken in from the air cleaner 10 is connected to an air flow meter 12, an intake throttle valve 14, a surge tank 16,
The air is sequentially sent to the intake manifold 18. This air is mixed with fuel injected from the injector 22 near the intake boat 20, and further passed through the intake valve 24 to the engine body 26.
is sent to the combustion chamber 26A. Exhaust gas generated as a result of combustion of the air-fuel mixture in the combustion chamber 26A passes through the exhaust valve 2.
8. Exhaust boat 30, exhaust manifold 32 and exhaust pipe (
(not shown) is released into the atmosphere. The air 70-meter 12 is provided with an intake air temperature sensor 100 for detecting the air intake air temperature. Further, the exhaust manifold 32 is provided with an exhaust temperature sensor 101 for detecting the exhaust temperature of the engine. The intake throttle valve 14 rotates in conjunction with an accelerator pedal (not shown) provided at the driver's seat. This intake throttle valve 14 is provided with a throttle sensor 102 for detecting its opening degree. Further, a water temperature sensor 104 for detecting the engine cooling water temperature is disposed in the cylinder block 26B of the engine main body 26. Further, the destroyer 38 having a shaft rotated by the crankshaft of the engine body 26 is equipped with a crank angle sensor 1 for detecting the crank angle from the rotation of the shaft.
08 is provided. The ECT is also provided with a vehicle speed sensor 110 for detecting vehicle speed from the rotational speed of its output shaft, and a shift position sensor 112 for detecting a shift position. Each of these sensors 100.101.102.104.1
The output of 08.110.112 is input to engine computer 40. The engine computer 40 calculates the fuel injection amount and optimum ignition timing using the input signals from each sensor as parameters, and controls the injector 22 to inject fuel for a predetermined time period corresponding to the fuel injection amount. The ignition coil 44 is controlled so as to obtain the optimum ignition timing. Further, an idle rotation speed control valve 42 driven by a step motor is provided in a bypass passage that communicates the upstream side of the intake throttle valve 14 with the surge tank 16.
A signal from the engine computer 40 controls the idle speed. On the other hand, the ECT transmission section 900 in this embodiment includes a torque converter 910, an overdrive mechanism 920, and an underdrive mechanism 930. The torque converter 910 includes a pump 911,
□It is a well-known model including a turbine 912 and a stator 913, and is equipped with a lock-up clutch 914. I can do it.
The overdrive mechanism 920 is a sun gear.
1 gear 921, a planetary meshing with the sun gear 921
Single core pinion 922, R planetary pinion 922
5 Supporting carrier 923, planetary pinion
j[,. A set of ring gears 924 meshing with 22
,. R1 is equipped with a planetary gear, and the rotation shape of this planetary gear is...
y=, Utsua. . ,A,-1,. , Tsuyu force. cormorant [
±, (Controlled by latch Fo.
(1) The underdrive mechanism 93-0 includes a common sun gear 931. Bra that meshes with il sun gear 931
□ Planetary pinion 932.933, carrier 934 supporting the planetary pinion 932.933,
:'935, planetary pinion 932.933 and...
Meshing: Two sets of ring gears 936 and 937 that mesh with each other are equipped with a planetary gear device, and the rotational shape of this planetary gear device is
1 (state) and the connection state with the overdrive mechanism are controlled by clutches C1 and C2, brakes 81 to Bs, and one-way clutches F+ and Fz. This transmission section 900 is well known in itself, so The connection state of each component will only be shown in a skeleton diagram in Fig. 2, and detailed explanation will be omitted. The 'll! magnetic valves S1 to S4 in the hydraulic control circuit 60 are driven and controlled by the ECT computer 50 to which signals from the sensor 110 and the like are input in accordance with a preset shift pattern, so that the ECT computer 50 receives signals from the sensor 110, etc. Combinations of engagement of each clutch, brake, etc. are performed to perform speed change control as shown in Fig. 4. In Fig. 3, the 0 mark indicates the operating state, and the ∆ mark indicates only when driving. , X mark indicates that it is activated only when the engine brake is used.Also, the *m valves S+, S
2 controls the speed change of the underdrive mechanism 930;
The solenoid valve S3 controls the overdrive mechanism 920, and the N[n valve S4 controls the lock-up clutch 920.
Each of the 14 different dishes is to be performed. In such a device, the engine computer 4
0 receives shift information (shift determination, shift command, lock-up clutch engagement permission, etc.) from the ECT computer 50 and executes engine torque control in relation to a signal from the exhaust temperature sensor 101. In addition, in this embodiment, the engine computer 40 and the EC
Although it is separate from the T-funputer 50, in the present invention, the control MIF! This does not limit the 1lIvl of the a unit or its control area. Next, the operation of this embodiment will be explained. The engine torque control of the vehicle in this embodiment is executed according to the flowchart shown in FIG. First, in step 200, it is determined whether flag C is 1 or 0. This flag C is related to the exhaust temperature and is a flag to indicate whether or not the engine torque control implementation area and torque increase/decrease change are being executed. O is sometimes selected. C-0, that is, when it is not being executed, the process proceeds to step 2o2, where it is determined whether the exhaust gas temperature detected by the exhaust temperature sensor 101 is equal to or higher than the reference value 111T'c, and the reference value T'C is determined.
Only in the above case, the program proceeds to step 204 to change the retard angle increase/decrease, and in step 206, 7 lag C is set to 1 to indicate that the retard angle increase/decrease is being changed. On the other hand, if it is determined that C-1, that is, the change in retardation increase/decrease is already being executed, the process proceeds to step 208 and the exhaust temperature is below the reference value "C" (however, T'C>T'C). If it is determined that the temperature is T'C or higher, the retardation increase/decrease continues to be changed, but T'C
If it is determined that the value is below, the process proceeds to step 210 to cancel the change in retardation increase/decrease, that is, the setting is returned to the normal engine torque reduction implementation area and retardation increase/decrease, and in step 212 flag C is set to O. will be reset. The following may be considered as the content of the change in the retard angle increase/decrease, for example. 1) Completely prohibit specific gear shifting. For example, this prevents engine torque control from being performed when downshifting to second gear (see Figure 6, actual size).
This can be realized by setting all the ignition timing increase/decrease constants to 0. In this way, it may be effective not to change the torque only when shifting to a specific gear position, for example, in the following cases. That is, the shift point of an automatic transmission is generally set upward to the right on the shift diagram, and at the same vehicle speed, the down point is set on the high throttle side with a certain hysteresis relative to the up point (see FIG. 4). Therefore, in automatic transmission vehicles, gear changes are repeated in a short period of time, such as when driving in mountains or intentionally by the driver, resulting in an upshift when the accelerator is released and a downshift when the accelerator is depressed. It is almost limited to cases where it is repeated. In addition, the control range of engine torque is generally limited to medium and high throttle openings as far as the throttle opening is concerned, so the gear shift where ignition timing control is performed is called the downshift when the accelerator is depressed. It turns out. Incidentally, in a downshift performed by depressing the accelerator, even if engine torque control during gear shifting is not performed, there is an increase in shift shock, but there are almost no problems with the durability of the automatic transmission. Therefore, even if the engine torque control is omitted only for a specific downshift, there will be no problem except that the shift shock will increase slightly. Rather, the increase in shift shock has the indirect effect of forcing the driver to refrain from frequently turning on and off the accelerator. 2) Prohibiting part of specific gear shifting. For example, in the case of downshifting from the second gear to the first gear, engine torque control is limited to only when the throttle opening is larger. That is, when the throttle opening is small, there is little need to change the engine torque in terms of either shift shock or durability of the automatic transmission. Therefore, for example, this is the case where the engine torque change is limited to only when the throttle opening is fully open. 3) Change the torque increase/decrease. For example, when retarding ignition timing is used as a means to change torque, the amount of retardation can be changed from 25° CA to 1
This means reducing the temperature to 5°CA. Return to the flowchart in Figure 5. After the selection range (C-0 or C-1) of the retardation amount relative to the exhaust temperature for engine torque change is determined in this way, the engine torque is changed only while the automatic transmission is being shifted. The processing to be done is done. That is, when a shift determination is made in step 214,
Proceeding to step 216, a shift command is issued. Then, in step 218, the engine torque is
Judgment will be made based on whether or not you have entered Ikatsuya MC'. Here, the inertia phase is a period during which the rotating members of the automatic transmission change their rotational speeds for gear shifting, and the inertia phase is a period during which the rotating members of the automatic transmission change their rotational speeds for gear shifting. A timer lets you know when to start. When it is determined in step 218 that the inertia phase has started, in step 220, the amount of retardation of the ignition timing is specifically determined according to the type of shift and the throttle opening within the selected range for the exhaust temperature selected previously. , performs ignition retardation in step 222. Thereafter, in step 224, the end of the inertia phase is detected, and in step 226, the ignition timing is restored. Note that steps 300 to 308 are steps related to setting a flag T to substantially stop the flow until the inertia phase starts and ends. According to this embodiment, the ignition timing increase/decrease (predetermined amount for engine torque change) is set for each gear shift based on the throttle opening at that time depending on the level of exhaust temperature. Even if the exhaust gas temperature becomes high, a further increase is suppressed. Also, as shown in FIG. 7, hysteresis is provided at the start and end of the change (step 202.
T'C1T'°C at 208), exhaust 11f#ff[l!
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8: I won't be disappointed. Next, the effects obtained by the method of this embodiment will be explained with reference to the schematic diagram shown in FIG. Under normal operating conditions, as shown in case A, for example, by controlling the ignition timing, the engine
Even if the air temperature rises as shown by the solid line in the figure,
: Since the frequency of this is low (for example, once every 10 seconds), the exhaust gas temperature can be easily recovered to a predetermined value, for example, 850° C., and there is no particular problem. However, as shown in case B, gear changes are performed frequently, for example, torque 1j twice in 10 seconds.
When LL control is performed, the exhaust temperature reaches the predetermined rf1 (8501
The next increase occurs before the exhaust gas temperature recovers to 950°C, which is the permissible value. For this reason, conventionally, to prevent such gradual increase,
Maximum torque of 1t! It is necessary to set the maximum decrease to a small value so that the engine can recover to the specified value even when the frequency of engine control is high, as shown by the broken line in the figure. The degree of freedom was small. In this embodiment, the exhaust gas temperature is actually detected, and the exhaust temperature is set as the reference 1i1!T'C (this reference ff1T'c is the allowable temperature (950°C in the example of the 8th village). The implementation range for engine torque control or torque increase/decrease is changed when the temperature becomes higher than Control can be suppressed, and a design with a high degree of freedom can be made so that the original purpose of torque control can be achieved under normal conditions.In general, when the exhaust temperature increases due to increasing or decreasing torque, the ignition It is possible to reduce the engine torque by delaying the timing, increase the engine torque by increasing the fuel injection amount, etc. In the present invention, we consider the case where the exhaust temperature actually rises due to engine torque control as a problem. Therefore, there is no particular problem with the means for controlling engine torque.However, it goes without saying that when changing, for example, real!fli[, the qualitative effects of these means on the exhaust temperature should be considered. Furthermore, in the above embodiments, it was shown that the execution range is changed depending on the throttle opening or the type of gear change, but the execution range in the present invention is changed depending on these types. The present invention is not limited to this, and the determination may be made depending on the vehicle speed in addition to or in place of the above.In addition, in the above embodiment, the reference value regarding the exhaust gas temperature is set to 2.
However, in the present invention, it is not necessary to provide hysteresis. Effects of the Invention 1 As explained above, according to the present invention, an increase in exhaust gas temperature is detected, and when the exhaust gas temperature is high, the implementation range and increase/decrease of engine torque control are suppressed. It is possible to set the actual 1M range or increase/decrease so that the original function of engine torque control can be carried out, and the FIM has the advantageous effect of being able to prevent the problem of an increase in exhaust temperature. It will be done.

[Brief explanation of drawings]

FIG. 1 is a flow chart showing the gist of the engine torque control method according to the present invention, and FIG. 2 is a flow chart showing the gist of the engine torque control method according to the present invention. FIG. 3 is a cross-sectional view including a partial block diagram showing the overall configuration of an automatic transmission combined with a sensing type electronic fuel injection engine, and shows the operation of QFIA engagement 4AM at each gear stage of the automatic transmission. The diagram showing the state, Figure 4, also shows the shift points at each gear stage.
1 cause,
[Figure 5 is a flowchart showing the engine torque change routine,
11. Figure 6 shows how to calculate the amount of change in ignition timing.
Figure 7 is a diagram showing an example of the map of F. Figure 7 is a diagram showing the relationship between two reference values. Figure 8 is a diagram showing the effects of the above embodiment and the problems of the conventional method. Figure 1. A diagram for schematically explaining from the perspective of □26...
- Engine body, 40... Engine computer, 50... ECT computer, 60... Hydraulic control circuit, 101... Exhaust temperature sensor, □T℃, T"C... Reference value.
;, 1:'1'・' Agent Takaya Theory
1'1'1, Keisuke Matsuyama '” Maki
No Tsuyoshi Hiroshi l'To Figure 1 Figure 3 ○----4 Sedoha J Δ----@hy Isuno-oj customary usage

Claims (4)

[Claims] (1) An engine torque control method that maintains good shifting characteristics of an automatic transmission by increasing or decreasing engine torque by a predetermined amount during gear shifting, comprising: a procedure for detecting the exhaust temperature of an engine; A method for controlling engine torque, the method comprising: changing at least one of the execution range of the engine torque increase/decrease control and the predetermined amount when the exhaust temperature of the engine is higher than a reference value. . (2) The engine torque control method according to claim 1, wherein the change in the implementation range is performed depending on the throttle opening. (3) The engine torque control method according to claim 1, wherein the change in the implementation range is performed depending on the type of gear change. (4) According to any one of claims 1 to 3, wherein two reference values are provided, and hysteresis is provided when starting the change and when canceling the change. The described method of controlling engine torque.