JPH0610451B2 - Engine torque controller - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine torque control device, and more particularly, to maintaining good gear shifting characteristics of an automatic transmission by changing the engine torque by a predetermined amount during gear shifting. To an improved engine torque control device.

[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 to achieve any one of a plurality of gear stages. The automatic transmission for a vehicle configured as described above is 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, JP-A-55-69738). That is, such integrated control of the automatic transmission and the engine changes the amount of torque transmission 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, to give the driver a good sense of gear shifting and to improve the durability of the friction engagement device.

[Problems to be Solved by the Invention]

However, for example, when a method of delaying the ignition timing is adopted as a means for changing (decreasing) the engine torque,
Due to the delay of the ignition timing, so-called afterburning increases and the exhaust temperature rises. Depending on the type of shift, control may be performed to increase the engine torque. In this case, as a method of changing (increasing) the engine torque, for example, a method of increasing the fuel supply amount or the intake air amount is used. Even if adopted, the exhaust temperature generally rises. As described above, the increase in the exhaust gas temperature caused by performing the engine torque control at the time of gear shifting does not cause any problem if the gear shifting frequency in normal driving is high. When the engine is turned on and off, the exhaust temperature rises above the permissible value, which may cause cracks in the exhaust manifold and damage to the turbine blades on the exhaust side in turbocharged engines when it is severe. . In addition, when the engine torque is changed extremely frequently, especially when the torque reduction control is performed, a method of suppressing the original combustion of the engine such as ignition retard is generally taken, so that the fuel consumption is deteriorated accordingly. Also, problems such as deterioration of the exhaust gas component to a specified value or more are likely to occur. Therefore, the routine design for engine torque control,
In addition, regarding the setting of the map of the engine torque change amount, etc., even if gear shifting is performed at the maximum expected frequency,
It is necessary to take measures so that the exhaust temperature does not rise excessively, or that problems do not occur in terms of fuel consumption and exhaust gas. However, from this point of view, for example, when the ignition timing retard amount is set to a small amount, the torque reduction amount in the engine torque control is naturally reduced, and the gear shifting characteristics including the durability of the friction engagement device are naturally reduced. There is a problem in that the original control purpose of improvement of the above may not be sufficiently exerted.

[Object of the Invention]

The present invention has been made in view of such conventional problems, in the engine torque control at the time of gear shifting, without inconvenience such as an increase in exhaust temperature, fuel consumption or deterioration of exhaust gas components, An object of the present invention is to provide an engine torque control device capable of setting a control execution region, a change amount, and the like so that the original function of the engine torque control can be sufficiently exerted.

[Means for solving problems]

The present invention relates to an engine torque control device for maintaining good gear shifting characteristics of an automatic transmission by changing the engine torque by a predetermined amount during gear shifting, as shown in FIG. A means for detecting the frequency of shifts at which the engine torque is changed, and a means for changing at least one of an execution region of the engine torque change control and the predetermined amount according to the frequency of shifts. ,
By providing the above, the above object is achieved. Further, according to the embodiment of the present invention, the change of the execution region is performed depending on the engine load, the vehicle speed, or the type of gear shift, so that the deterioration of the gear shift characteristic is suppressed to the minimum and the exhaust temperature rises. It is possible to appropriately prevent the occurrence of problems such as.

[Action]

In the present invention, the frequency of torque change is actually detected, and when the change frequency becomes equal to or higher than the reference value, the execution region of engine torque control that should be originally performed during the shift and the torque change amount are changed. Therefore, it is necessary to set design restrictions to avoid inconveniences such as exhaust temperature rise, fuel consumption, and deterioration of exhaust gas components when designing the engine torque control routine or setting the torque change amount. Instead, it becomes possible to perform (sufficiently effective) engine torque control according to the original purpose.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 2 is an overall schematic view of an automatic transmission (hereinafter referred to as ECT) combined with an intake air amount sensing type electronic fuel injection engine for an automobile according to an embodiment of the present invention. The air taken in from the air cleaner 10 is supplied to the air flow meter 12, the intake throttle valve 14, the surge tank 16,
Sequentially sent to the intake manifold 18. This air is mixed with fuel injected from the injector 22 in the vicinity of the intake port 20, and further flows through the intake valve 24 to the engine body 26.
Is sent to the combustion chamber 26A. The exhaust gas generated as a result of the combustion of the air-fuel mixture in the combustion chamber 26A is the exhaust valve 2
The gas is released to the atmosphere via the exhaust port 8, 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. This intake throttle valve 14
Includes a slot sensor 10 for detecting its opening.
Two are provided. A water temperature sensor 104 for detecting the engine cooling water temperature is provided on the cylinder block 26B of the engine body 26. Further, the distributor 38 having a shaft rotated by the crank shaft of the engine body 26 is provided with a crank angle sensor 108 for detecting a crank angle from the rotation of the shaft. Further, the ECT includes a vehicle speed sensor 110 for detecting the vehicle speed from the rotation speed of the output shaft, and a shift position sensor 1 for detecting the shift position.
12 are provided. Each of these sensors 100, 102, 104, 108, 1
The outputs of 10 and 112 are input to the engine computer 40. In the engine computer 40, the fuel injection amount and the optimum ignition timing are calculated using the input signal from each sensor as a parameter, and the injector 22 is controlled so that the fuel is injected for a predetermined time corresponding to the fuel injection amount. The ignition coil 44 is controlled so that the optimum ignition timing is obtained. Further, an idle rotation speed control valve 42 driven by a step motor is provided in a bypass passage that connects the upstream side of the intake throttle valve 14 and the surge tank 16.
The idle rotation speed is controlled by a signal from the engine computer 40. On the other hand, the ECT transmission unit 900 in this embodiment includes a torque converter 910, an overdrive mechanism 920, and an underdrive mechanism 930. The torque converter 910 is a well-known type including a pump 911, a turbine 912, and a stator 913, and includes a lockup clutch 914. The overdrive mechanism 920 includes a sun gear 921,
Planetary pinion 92 that meshes with the sun gear 921
2. Carrier 9 supporting the planetary pinion 922
23, a set of planetary gear units consisting of a ring gear 924 meshing with the planetary pinion 922, and the rotation state of this planetary gear unit is controlled by the clutch C ₀ , the brake B ₀ , and the one-way clutch F ₀ . . The underdrive mechanism 930 is a common sun gear 9
31, planetary pinion 932, 933 meshing with the sun gear 931, planetary pinion 932, 933
Ring gears 936 and 937 that mesh with the carriers 934 and 935 that support the planetary pinion 932 and 933.
2 sets of planetary gear units are provided, and the rotation state of the planetary gear unit and the connection state with the overdrive mechanism are clutches C ₁ , C ₂ , brakes B ₁ -B ₃ , and one-way clutch F ₁ , It is controlled by F ₂ . Since this transmission section 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 is provided with the transmission section 900 as described above, and the ECT computer 50 to which signals of the throttle sensor 102, the vehicle speed sensor 110, etc. are input is operated in accordance with a preset shift pattern. The solenoid valves S _{1 to} S ₄ in the hydraulic control circuit 60 are driven and controlled, and the engagement of the clutches, brakes, etc. as shown in FIG. Shift control is performed. In FIG. 3, the mark ◯ indicates the operating state, the mark Δ indicates the operating state only when driving, and the symbol x indicates the operating state only when the engine brake is used. Also, the solenoid valves S ₁ , S ₂
Controls the shift of the underdrive mechanism 930, the solenoid valve S ₃ controls the overdrive mechanism 920, and the solenoid valve S ₄ controls the lockup clutch 914.
Are controlled respectively. In such a device, the engine computer 4
0 receives the shift information (shift determination, shift command, lock-up clutch engagement permission, etc.) of the ECT computer 50, and executes engine torque control in relation to the frequency of engine torque control. In this embodiment, the engine computer 40 and the EC
Although the T computer 50 is provided separately, the present invention does not limit the number of control devices or the control sharing area 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, when a shift determination is made in step 200,
A gear shift command is issued at step 202. afterwards,
At step 204, it is determined whether the shift is an upshift. If it is an upshift, the routine proceeds to step 206 and thereafter, and torque down control at the time of shifting is performed. That is, first, at step 206, the engine torque change start timing is determined based on whether or not the automatic transmission has entered the inertia phase. Here, the inertia phase is a period during which the rotating member of the automatic transmission changes the rotating speed for shifting, and it detects the rotating speed of a predetermined rotating member, the engine rotating speed, or when a shift command is issued. It is possible to know the start time by the timer. Step 20
When it is determined in step 6 that the inertia phase has started, a torque down command is issued in step 208, and after waiting for the detection of the end of the inertia phase in step 210, a torque recovery command is issued in step 212. After the torque recovery command is issued at step 212, the routine proceeds to step 214, where the timer Tc (sec) is compared with the reference value T ₀ (sec). Where timer T _c
In step 216, is cleared and started after the engine torque is changed, and corresponds to the time from the end of the previous torque change to the end of the current torque change. The timer T _c is larger than the reference value T ₀ , and the step 2
When it is judged that N <N _{0 at} 18, N = 0 is set at step 220, and the routine proceeds to step 216.
Here, N is an index value indicating how many times the torque has been changed next within a time period T ₀ sec after a certain torque change, that is, the change frequency of the torque change. On the other hand, when it is determined that the timer T _c is equal to or less than T ₀ , N = N + 1 is set in step 222, and the value of the index value N is checked in step 224. Step 22
At 4, it is determined whether the index value N is equal to the reference value N _0, and when they are equal, the downshift prohibit timer T _b is cleared and started at step 226. If they are not equal, step 226 is bypassed and step 216 is reached directly. On the other hand, when it is determined in step 204 that the shift is not an upshift, the process proceeds to step 228, and it is determined whether the index value N is larger than the reference value N ₀ . When the index value N is smaller than the reference value N ₀ , the downshift torque control at step 230 and below is executed. That is, in step 230, it is judged whether or not the engine rotation speed is about to reach the synchronous rotation speed obtained from the output shaft rotation speed according to the gear ratio, and at the stage immediately before the synchronization, the torque down command is issued in step 232. is, in large Natsuta time also the timer T is above the predetermined value T ₄ from the torque-down command (step 234), in which the torque return command is issued at step 236. On the other hand, when it is determined in step 228 that the index value N is greater than or equal to the reference value N ₀ , the downshift prohibit timer T _b is checked in step 238. That is, when the timer T _b is larger than the reference value T ₃ is the index value N is cleared at step 240, similarly step 2
The torque control of 30 to 236 is executed. On the other hand, the reference value T
If it is ₃ or less, it will be reset. Note that steps 300 to 306 are steps 206 and 2
This is a step regarding the setting of the flag T for substantially stopping the flow until the conditions of 10, 230 and 234 are satisfied. Summarizing the above in accordance with the actual shift, the fact that the next torque change is made within T ₀ sec from a certain torque change is N _0.
In the case of continuous number of times, torque control is prohibited only for downshift for T ₃ sec. In this case, if the upshift occurs after N ₀ consecutive times, the torque control is performed after the step 21.
However, if the timer (time from change to change) T _c is longer than the reference value T ₀ , step 21
At step 216, N ≧ N _0, and at step 216, only the timer T _c is cleared and started. If the timer T _c is shorter than the reference value T ₀ , at step 218, N> N _0, and then step 216. Therefore, even in this case, the index value N,
Only the timer T _c is cleared Start does not affect the down-shift prohibition timer T _b. On the other hand, when the index value N is less than the reference value N ₀ , it is cleared when the timer T _c is longer than the reference value T ₀ , and when it is more than the reference value N ₀ , downshift is performed. It is cleared when has fallen longer than the downshift prohibition timer T _b is the reference value T ₃ Te. Further, the downshift prohibit timer _Tb is cleared and started only when the index value N becomes equal to the reference value N ₀ . As described above, in the above embodiment, the torque control during the gear shift is prohibited only in the downshift (the execution region of the engine torque change control is changed depending on the type of gear shift).
The reason for doing so is as follows. That is, the shift point of the automatic transmission is generally set on the high slot side with upward hysteresis on the shift diagram, and at the same vehicle speed, the down point has a certain hysteresis with respect to the up point (see FIG. 4). Therefore,
In automatic transmissions, shifting is repeated in a short time when traveling uphill or when the driver intentionally repeats an upshift when the accelerator is released and a downshift when the accelerator is depressed. Almost limited. Further, in general, the region (implementation region) in which the engine torque is changed during gear shifting is generally limited to the medium / high throttle opening as far as the throttle opening is concerned. It means a downshift when stepped on. By the way, in the downshift that is performed by stepping on the accelerator, even if the engine torque control during the shift is not performed, the shift shock increases, but the durability problem of the automatic transmission hardly occurs. . Therefore, even if the engine torque control is omitted only for the downshift, there is no particular problem because the gearshift shock slightly increases. Rather, the increase in the gear shift shock has an indirect effect of causing the driver to frequently control the accelerator on / off. Next, the effect obtained by this embodiment will be described with reference to the schematic diagram shown in FIG. In a normal operating state, as shown in Case A, even if the exhaust temperature of the engine rises as shown by the solid line in the figure due to the control of the ignition timing, the frequency is low (for example, once every 5 seconds). Therefore, the exhaust temperature is a predetermined value, for example, 850
It can be easily recovered to ℃ and there is no particular problem.
Further, there is no particular problem in terms of fuel consumption and exhaust gas components. However, as shown in Case B, when gear shifting is frequently performed and, for example, torque control is performed twice in 5 seconds, the next rise occurs before the exhaust temperature recovers to a predetermined value (850 ° C.). As a result, the exhaust gas temperature gradually increases and finally reaches the allowable value of 950 ° C. or higher. Also, problems will occur from the viewpoints of fuel consumption and exhaust gas components. Therefore, conventionally, in order to prevent such problems,
Set the maximum value of torque control (maximum change amount) to a small value,
As shown by the broken line in the figure, it is necessary to set so that no problem occurs even when the frequency of engine control is high, and the degree of freedom in designing regarding torque control is reduced accordingly. In this embodiment, to detect the frequency N of the torque control of the engine, when該頻degree is the reference value N ₀ or more, suppressing the engine torque control according to t ₃ sec between downshift at time t ₃ in FIG. Therefore, the above problem can be avoided (two-dot chain line). Therefore, the torque control can be suppressed only when a problem may occur, so that a design with a high degree of freedom that can achieve the original purpose of the torque control can be performed in normal times. In the above embodiment, when the engine torque control frequency is high, the torque control is suppressed only in the downshift, that is, the torque control execution region is set depending on the type of shift. I was trying to change it,
The means for suppressing the torque control in the present invention is not limited to this. For example, the engine torque control is performed only when the throttle opening (engine load) is larger than usual, or the execution area is changed. Or, change only when the vehicle speed is low, or decrease the amount of change in torque control, for example, when using the ignition timing retard as a means for torque control, decrease the retard amount. You may make it use the means etc. which make it do. Such means can be realized by selecting the map in each of the cases of YES and NO in step 238 of FIG.

【The invention's effect】

As described above, according to the present invention, the frequency of the shift in which the engine torque is changed is detected, and when the frequency of the shift is high, the execution region and the change amount of the engine torque control are changed. Therefore, it is possible to set an implementation range or change amount so that the original function of engine torque control can be exerted, and with a simple configuration, problems such as exhaust temperature rise, fuel consumption or exhaust gas component deterioration occur. There is an excellent effect that it can be avoided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an engine torque control device according to the present invention, and FIG. 2 shows an embodiment of an engine torque control device according to the present invention, which is an intake air amount sensing type electronic fuel injection. Sectional drawing which shows the whole structure of the automatic transmission combined with the engine, 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, FIG. 4 is a diagram showing shift points at each shift stage, FIG. 5 is a flow chart showing a similar engine torque changing routine, and FIG. 6 is a diagram showing the effects of the above-described embodiment in view of a conventional malfunction. It is a diagram for explaining typically. 26 ...... engine body, 40 ...... engine-computer, 50 ...... ECT computer, 60 ...... hydraulic control circuit, N ...... index value (change frequency), N ₀ ...... reference value.

Claims (2)

[Claims] 1. An engine torque control device for maintaining good gear shifting characteristics of an automatic transmission by changing the engine torque by a predetermined amount during gear shifting, wherein the gear shifting is such that the engine torque is changed. And a means for changing at least one of the predetermined region and the execution region of the engine torque change control according to the frequency of the shift. Engine torque control device. 2. The engine torque control device according to claim 1, wherein the change of the working area is performed depending on at least one of engine load, vehicle speed, and type of gear shift.