JP3146676B2 - Engine output control device for vehicle with automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine output control device for a vehicle equipped with an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, an automatic transmission equipped with a torque converter has a stalled state at the time of starting, that is, slippage between a driving (input) shaft side impeller and a driven (output) shaft side impeller. (Rotational speed difference) continues, the intermediate fluid between the drive shaft-side impeller and the driven shaft-side impeller receives a shearing force to generate heat and continue the overheated state. Therefore, if this state extends for a long time or is frequently repeated, the function of the torque converter main body may be deteriorated because the medium fluid is thermally degraded with time and deteriorates in function.

For this reason, conventionally, when the output of an engine is to be improved, the stall state is more likely to occur due to the increase in the output. Therefore, the transmission torque capacity of the torque converter is increased to overheat the medium fluid. And other measures were taken. In addition, Jiko 60-1592
As in the prior art disclosed in No. 56, the vehicle speed zero state and other conditions are detected, and under a certain condition, the transmission is set to the neutral state and the drive (input) is performed.
In some cases, slip (rotational speed difference) is eliminated between the shaft-side impeller and the driven (output) shaft-side impeller, thereby reducing the heat generation of the fluid to some extent and preventing the torque converter from overheating. .

[0004]

However, in the conventional measures for increasing the transmission torque capacity of the conventional torque converter, the weight and the size of the torque converter increase with an increase in the output of the engine. At the time of mounting, various problems such as an increase in vehicle weight and an increase in mounting space occurred.

On the other hand, in the prior art disclosed in the above-mentioned Japanese Utility Model Publication No. 60-159256, overheating of the intermediate fluid is prevented by setting the transmission to the neutral position only when the vehicle is completely stopped with the brake applied. Therefore, with respect to the stall state at the time of starting when the medium fluid generates the most heat, the overheating of the medium fluid cannot be reduced, and a sufficient overheating reduction effect cannot be expected. Further, since the transmission is complicated, there are also problems such as an increase in the weight and dimensions of the device and an increase in production cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and it is possible to prevent deterioration of a function over time caused by overheating of an intermediate fluid in a stall state of a torque converter and to reduce the production cost. It is an object to provide a control device.

[0007]

As a result, an engine output control apparatus according to the present invention, as shown in FIG. 1, is used in a vehicle equipped with an automatic transmission equipped with a torque converter. Vehicle speed detecting means A which can detect the vehicle speed of the automatic transmission, traveling shift position detecting means B which can detect that the shift position of the automatic transmission is at the traveling shift position, and the engine output state of the engine G is the limit stall output of the torque converter. A high output state detecting means C capable of detecting the above high output state, and a stall state in which all of the engine high output states that are equal to or lower than the predetermined vehicle speed, the traveling shift position, and the limit stall output of the torque converter are detected. Stall status to determine if
The determining means D determines that a stall state has occurred,
Until the predetermined time has passed since the stall state
The first method for controlling the ignition timing to reduce and correct the engine output
The output decrease correction means E determines that a stall state has occurred.
And after a lapse of a predetermined time from the stall state,
Control the amount of fuel supply or intake air to increase engine output.
And a second output decrease correction means F for performing further decrease correction .

[0008]

With this configuration, by detecting that the vehicle speed is equal to or lower than a predetermined vehicle speed, that the shift position is at the traveling shift position, and that the engine output state is a high output state that is equal to or higher than the limit stall of the torque converter, Torqueco
Whether the inverter has stalled beyond a certain condition
Is determined. Then, it is determined that a stall condition has occurred.
And a predetermined time has passed since the stall state
Until the engine output is reduced by controlling the ignition timing
After a lapse of a predetermined time from the stall state, the fuel
Control the supply amount or intake air amount to further increase engine output
Correct the decrease. Therefore, especially when the vehicle is stopped and
When the stall condition exceeds a certain condition at the time
In this method, the engine output is corrected to decrease so that the medium fluid of the torque converter does not overheat, so that overheating of the torque converter due to stall is prevented. In this case, the engine
The output reduction correction is performed at the time of ignition with good response and accuracy first.
It is performed by the period control, and the state is observed for a predetermined time. And
If the stall condition is resolved during that time,
Stop the stall while meanwhile the stall condition is not resolved
If not, judge that the output reduction correction is insufficient.
Fuel supply or suction
Output reduction correction is performed by controlling the air volume. Therefore,
Since the engine output will decrease in two stages,
The difference in engine output change is reduced, and engine
Is prevented from lowering. In addition, it became stall condition
Immediately after, without waiting for the state to last for a predetermined time
The engine output is slightly reduced by ignition timing control.
Therefore, the temperature rise of the intermediate fluid is suppressed efficiently.
You.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described below with reference to the accompanying drawings. In FIG. 2, the engine 1 includes:
Air is sucked in through the air cleaner 2, the intake duct 3, the throttle chamber 4, and the intake manifold 5. An air flow meter 6 is provided in the intake duct 3 and outputs a voltage signal corresponding to the intake air flow rate Q.

The throttle chamber 4 is provided with a throttle valve 7 interlocking with an accelerator pedal (not shown) so that the intake air flow rate Q can be controlled. In the intake manifold 5, a fuel injection valve 8 is provided for each cylinder. The fuel injection valve 8 is an electromagnetic fuel injection valve that is energized by a solenoid and opens, and is de-energized and closed by a drive pulse signal from the control unit 30 to control the opening degree. I have.

Each cylinder of the engine 1 is provided with an ignition plug 10 to which a high voltage generated by an ignition coil 11 is sequentially applied via a distributor 12, thereby spark-igniting. The mixture is ignited and burned. The timing at which the ignition coil 11 generates a high voltage is controlled via a power transistor 13 attached thereto. Therefore, the ignition timing is controlled by controlling the ON / OFF timing of the power transistor 13 with the ignition timing control signal from the control unit 30.

The distributor 12 has a built-in photoelectric crank angle sensor 14 and a control unit 30 based on a signal from the photoelectric crank angle sensor 14.
, The engine speed is calculated. Further, a voltage signal corresponding to the vehicle speed from the vehicle speed sensor 15 is input to the control unit 30.

The automatic transmission 40 is provided with an NP position sensor 16 for detecting a neutral position and a parking position, and a signal from the NP position sensor 16 is input to the control unit 30. It has become. Here, the microcomputer in the control unit 30 determines the effective fuel injection amount Te based on the signals from the various sensors, for example, by performing the following arithmetic processing, and uses this as a drive pulse signal. Output to the fuel injection valve 8. A basic fuel injection amount Tp = c × Q / N (c is a constant) is calculated from an intake air flow rate Q obtained from a voltage signal from the air flow meter 6 and an engine rotation speed N obtained from a signal from the crank angle sensor 14. At the same time, an effective fuel injection amount Te = Tp × α × K × Co is calculated based on the air-fuel ratio feedback correction coefficient α, the air-fuel ratio learning control coefficient K, and various correction coefficients Co. A drive pulse signal having a pulse width corresponding to the effective fuel injection amount Te is based on a relationship (so-called map) between the engine rotation speed N, the effective fuel injection amount Te, the fuel injection timing, and the ignition timing stored in advance. And the opening degree of the fuel injection valve 8 is controlled. The control unit 30 stores several types of maps according to when the engine is cold, when the engine is warmed up, and the like, and a map according to each condition is selected.

Next, control of the control unit 30 according to the present invention will be described with reference to the flowchart of FIG. In step 1 (shown in the figure as STEP 1; the same applies hereinafter), the control state of the control unit 30 is reset to a state in which the torque converter is not in a stall state (# TCFLG = 0), and the timer is reset. (# TCTMR = 0).

In step 2, the vehicle speed V detected by the vehicle speed sensor 15 is equal to or less than a predetermined value Vsp (V ≦ Vsp).
In the case of, the process proceeds to step 3, and if V> Vsp, the process proceeds to step 7. Here, step 2 and the vehicle speed sensor 15 correspond to a vehicle speed detecting means. In step 3, it is determined from the signal from the NP position sensor 16 whether the shift position of the automatic transmission is in the neutral position or the parking position. When it is determined that the shift position is the shift position, the process proceeds to step 4. When the shift position is not the traveling shift position, the process proceeds to step 7 when the shift position is not the neutral position or the parking position.
Here, the traveling shift position detecting means is constituted by the step 3 and the NP position sensor 16.

In step 4, the crank angle sensor 1
4 is read into the control unit 30. In step 5, the engine load Tp is obtained from the effective fuel injection amount Te calculated by the above-described method based on the engine speed N read in step 4 and the intake air flow rate Q detected by the air flow meter 6. Can be And
The engine load Tp is equal to or greater than a predetermined value TBLTPC (Tp ≧
TBLTPC) to determine whether Tp ≧ TBL
In the case of TPC, the process proceeds to step 6, where Tp <TBLT
In the case of a PC, the process proceeds to step 7. Here, the predetermined value T
BLTPC is set at the limit stall point of the torque converter.
Set. That is, when the engine load Tp is equal to the predetermined value TBLTPC
If above, the torque converter is stalled
It is determined that the engine load Tp is equal to the predetermined value TBLT.
If it is less than PC, the torque converter is stall
It is determined that there is not.

Here, steps 4 and 5 constitute a high output state detecting means of the engine. In step 6, since it is determined in step 5 that the engine load is equal to or more than the predetermined value, it is determined that the torque converter is in a stall state. Thereafter, the process proceeds to step 8.

In step 7, since it is determined in step 5 that the engine load is less than the predetermined value, it is determined that the torque converter is not in a stall state.
Proceed to step 8. In step 8, step 6
If the torque converter is in a stall state based on the result of the determination in step 7, the control state of the control unit 30 is set to # TCFLG = 1, and the process proceeds to step 9. On the other hand, if it is not in the stall state, this flowchart ends. In addition, the processing of step 2 to step 8
It corresponds to a stall state determination unit.

In step 9, since it is determined that the torque converter is in a stalled state, the timer built in the control unit 30 is started to count up in order to measure the duration of the stalled state of the torque converter. (# TCTMR = # TCTMR
+1). Then, in step 10, the measurement time TCTMR of the timer is set to a predetermined time T
It is determined whether or not CNG1 has been reached (TCTMR ≧ TCNG1), and if not (TCTMR <TCNG1)
Proceeds to step 11 and, if reached (TCTMR ≧ T
The process proceeds to step 12 for CNG1).

In step 11, the measurement time TCMTR has not reached the predetermined time TCNG1 in step 10 (TC
When it is determined that TMR <TCNG1), an ignition timing delay control signal is sent to the power transistor 13 to control the engine output to be suppressed to a predetermined value or less by delaying the ignition timing. That is, the ignition timing delay map corresponding to step 11 is selected from the various maps stored in the control unit 30 in advance, and the ignition timing retard control is performed, and the engine output is suppressed to a predetermined value or less. It is done. The ignition timing retard control is maintained until the measurement time TCTMR reaches the predetermined time TCNG1.

Here, the processing in step 11 is the first output.
This corresponds to a force reduction correction unit . Subsequently, in step 12, the measurement time TCMTR is set to the predetermined time TC in step 10.
If it is determined that NG1 has been reached and it is determined that the torque converter has been in the stall state for a long time,
In the engine output decrease correction control based on the ignition timing retard, when it is determined that the engine output cannot be controlled below the predetermined value, the measurement time TCTMR is increased to the predetermined time TCNG2.
(> Predetermined time TCNG1 in step 11).
It is determined whether or not CTMR ≧ TCNG2. If it is not reached (TCTMR <TCNG2), the process proceeds to step S13.

In step 13, the measurement time TCTMR has not reached the predetermined time TCMR2 in step 12 (TC
When it is determined that TMR <TCNG2), in order to further suppress the engine output, a drive pulse signal for instructing the fuel injection valve 8 to reduce the fuel injection amount is sent to suppress the engine output to a predetermined value or less. Is controlled as follows. That is, the fuel injection amount reduction map corresponding to the step 13 is selected from the various maps stored in the control unit 30 in advance, the fuel injection amount reduction control is performed, and the engine output is suppressed to a predetermined value or less. It is done. Then, the measurement time TCTMR is equal to the predetermined time TCMR2.
Is maintained until the fuel injection amount is reduced.

Here, the processing in step 13 is the second output.
This corresponds to a force reduction correction unit. Thereafter , the flowchart repeats the above steps, and when the conditions are not satisfied in steps 2, 3, and 5, the flowchart ends.

The engine output at the time of starting in steps 11 and 13 is suppressed, for example, as shown in FIG. The horizontal axis in FIG. 4 is the engine speed N, and the vertical axis is the engine output (in this case, engine torque). The solid line indicates the fully open performance curve of the engine 1 according to the present embodiment, and the broken line indicates the performance curve after the output decrease correction. Here, it is assumed that the transmission torque capacity of the torque converter connected to the engine is sufficiently applicable to the performance curve after the output decrease correction shown by the broken line.

That is, at the time of starting, in order to prevent overheating due to an increase in the stall state of the torque converter due to an increase in the output of the engine, on the rotational speed side lower than the limit stall point G in the torque converter region of the torque converter, The full-open performance is controlled to pass on a curve shown by a broken line. On the other hand, on the higher rotational speed side than the limit stall point G, since the torque converter is in the coupling region, overheating of the torque converter due to stall does not occur, the reduction correction control of the engine output is released and indicated by the solid line. It passes through the full-open performance curve of a high-power engine. Then, as described above, the engine output decrease correction control is performed first in step 11 until a fixed time has elapsed from immediately after the vehicle starts (at an extremely low speed).
The ignition timing retard control is performed , and after that, when the predetermined time has elapsed and the control cannot be completely suppressed by the control in step 11 alone, the fuel injection amount reduction control in step 12 is further performed.

Of course, when the vehicle speed has reached a predetermined value or more, the engine output reduction correction control is canceled, and it goes without saying that the engine exhibits its full open output performance. Further, for example, when the shift position of the automatic transmission is in the forward or reverse position while the vehicle is at a stop, the engine is fully opened with the foot brake applied, so that it is difficult to imagine in normal use. However, since the decrease correction control is performed to the engine output corresponding to the transmission torque of the torque converter, the durability of the torque converter is not impaired even when a high-output engine is used.

Further, for example, when the driver forgets to release the parking brake, when the vehicle is fully loaded, or when climbing a hill, the vehicle speed (acceleration force) should be the same as when the normal load is relatively small. Since the engine output needs to be higher than the engine output during normal use, when a high output engine is used, it is used in a state exceeding the transmission torque of the torque converter, that is, in an area exceeding the limit stall point. Although the possibility increases, in the present embodiment, since the engine load is detected and the engine output reduction correction control is performed, the engine is not used in a state exceeding the transmission torque of the torque converter.
Even under such usage conditions, the durability of the torque converter is not impaired.

As described above, in the engine control device according to the present embodiment, the engine output is matched with the transmission torque of the torque converter when the torque converter is in a stall state and the vehicle starts to start when the medium fluid is overheated. Since the decrease correction control can be performed on the engine output, the durability of the torque converter can be ensured even when a high output engine is used.

In this embodiment, the method of reducing the fuel injection amount is used as the engine output control means .
For example, a method of stopping the supply of fuel to at least one of the fuel injection valves, a method of reducing the intake air flow rate, or the like may be used .

[0030]

As described above, the engine control device according to the present invention can be used when the vehicle stops and starts.
Since the engine output can be reduced and controlled to an engine output corresponding to the transmission torque capacity of the torque converter, even when a high-output engine is used, overheating of the intermediate fluid can be prevented and the durability of the torque converter can be ensured. At the same time, it is possible to minimize the necessity of setting a new torque converter according to the output of the engine, and to reduce the production cost because the large-scale automatic transmission itself does not require complicated changes. In addition, since an increase in vehicle weight can be eliminated, it is possible to further improve running fuel efficiency and the like. In this case, the engine output
, The response and accuracy are reduced within the specified time.
Performed by good ignition timing control, during which stall
If the condition is not resolved, the output reduction
Fuel supply that can reduce power more
This is performed by controlling the amount or intake air amount. Therefore,
The engine output will decrease in two steps,
The difference in change in gin output is reduced,
Can be prevented from lowering. Also stall state
Immediately after it becomes,
Slightly reduce engine output with ignition timing control without waiting
Control the temperature rise of the medium fluid efficiently.
I can.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to a claim according to the present invention.

FIG. 2 is a configuration diagram showing one embodiment according to the present invention.

FIG. 3 is a flowchart of the above.

FIG. 4 is a performance curve diagram showing output characteristics of the engine whose output is controlled by the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 6 Air flow meter 8 Fuel injection valve 10 Spark plug 14 Crank angle sensor 15 Vehicle speed sensor 16 NP position sensor 30 Engine control unit 40 Automatic transmission equipped with torque converter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI F02P 5/15 F16H 59/44 F16H 59/44 F02P 5/15 BL (58) Investigated field (Int.Cl. ⁷ , DB Name) F02D 29/00-29/02 B60K 41/00-41/06 F02P 5/15 F16H 59/44

Claims (1)

(57) [Claims] 1. A vehicle equipped with an automatic transmission equipped with a torque converter, a vehicle speed detecting means capable of detecting a vehicle speed at least equal to or less than a predetermined value near a stop, and detecting that a shift position of the automatic transmission is at a traveling shift position. Traveling shift position detecting means, a high output state detecting means capable of detecting that an engine output state is a high output state equal to or higher than a limit stall output of the torque converter, a vehicle speed, a traveling shift position, and a torque converter below the predetermined value. A stall that determines whether or not the engine has reached a stall state in which all high engine output states that exceed the limit stall output
And a stall state, and a stall state is determined.
Until the specified time has passed since
Output reduction correction means for reducing and correcting the engine output
If, it is determined that a stall state and the stall state
After a lapse of a predetermined time, the fuel supply amount or intake air
Control the amount to further reduce the engine output.
An output control device for an engine, comprising: an output decrease correction unit .