JPH06101510A - Output controller of engine in vehicle with automatic transmission - Google Patents

Abstract

PURPOSE:To prevent secular deterioration of function caused by overheat of catalyst fluid at the time of a stall condition of a torque converter by decreasingly correcting output of an engine at the time when a vehicle speed more than a specified speed running shift position, and high output condition more than specified condition are continued for more than specified periods. CONSTITUTION:An automatic transmission provided with a torque converter is mounted on a vehicle. In this case at least a vehicle speed less than a specified speed close to that for stopping vehicle is detected by a vehicle speed detection means A. It is a detected by a vonning shift position detection means B that the shift position of an automatic transmission is in its drive shift position. It is also detected by a high output condition detection means C that the output condition of an engine E is in a high output condition which is more than specified condition. The output of the engine E is decreasingly corrected by an output decrease correction means D when the vehecile speed more than specified value the running shift position and the high output condition more than the specifed values are all detected. Consequently, deterioration of function caused by overheat of catalystic fluid is prevented at the time of a stall condition of a torque converter.

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 in a vehicle with an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, an automatic transmission equipped with a torque converter is stalled at the time of starting, that is, slips between a driving (input) shaft side impeller and a driven (output) shaft side impeller ( When the state in which the rotational speed difference) is generated is continued, the intermediary fluid between the impeller on the drive shaft side and the impeller on the driven shaft side receives a shearing force to generate heat and continue to be in an overheated state. Therefore, if this state continues for a long time or is repeatedly repeated, the mediating fluid is thermally deteriorated with time and its function is deteriorated, so that the function of the torque converter main body may be deteriorated.

Therefore, conventionally, when the output of the engine is improved, the stall state is more likely to occur due to the improved output, so that the transmission torque capacity of the torque converter is increased and the medium fluid is overheated. We were taking measures to prevent such problems. In addition, actual public Sho 60-1592
As in the prior art disclosed in No. 56, the vehicle speed zero state and other conditions are detected, the transmission is neutralized under a certain condition, and the drive (input) is performed.
There is a device in which slippage (rotational speed difference) is eliminated between the shaft-side impeller and the driven (output) shaft-side impeller to reduce heat generation of the fluid to some extent and prevent overheating of the torque converter. .

[0004]

However, in the conventional measures for increasing the transmission torque capacity of the torque converter, the weight and size of the torque converter increase as the output of the engine increases. When mounted, various problems such as an increase in vehicle weight and an installation space have occurred.

On the other hand, in the prior art disclosed in Japanese Utility Model Publication No. 60-159256, the transmission gear is prevented from being overheated by setting the transmission to the neutral position only when the brake is applied to stop the vehicle completely. Therefore, with respect to the stall state at the time of starting, in which the medium fluid generates the most heat, it is not possible to reduce the overheating of the medium fluid, and a sufficient effect of reducing overheating cannot be expected. Further, since the transmission becomes complicated, there are problems such as an increase in the weight and size of the apparatus and an increase in production cost.

The present invention has been made in view of the above conventional problems. In the stall state of the torque converter, it is possible to prevent the deterioration of the function over time due to overheating of the intermediate fluid and to reduce the production cost of the engine output. An object is to provide a control device.

[0007]

Therefore, as shown in FIG. 1, an engine output control apparatus according to the present invention is, in a vehicle equipped with an automatic transmission equipped with a torque converter, at least a predetermined value close to a stop or less. The vehicle speed detecting means A capable of detecting the vehicle speed, the traveling shift position detecting means B capable of detecting that the shift position of the automatic transmission is at the traveling shift position, and the engine output state of the engine E being a high output state above a predetermined level. The high output state detecting means C capable of detecting the presence of the vehicle, and the engine output is reduced and corrected when the state in which the vehicle speed below the predetermined value, the traveling shift position, and the high output state above the predetermined value of the engine are all detected for a predetermined time or longer. The output decrease correction means D is provided.

[0008]

With such a configuration, by detecting that the vehicle speed is lower than a predetermined speed, the shift position is in the traveling shift position, and the output state of the engine is detected, it is possible to meet a certain condition or more, especially when the vehicle is stopped or started. If the stall condition of the torque converter occurs, it is judged whether the stall condition exceeds a certain condition.If the stall condition exceeds a certain condition, the engine output is reduced and corrected so that the medium fluid of the torque converter does not overheat. Overheating of the converter is prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the accompanying drawings. In FIG. 2, the engine 1 has
Air is taken 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 which works in conjunction with an accelerator pedal (not shown) so that the intake air flow rate Q can be controlled. The intake manifold 5 is provided with a fuel injection valve 8 for each cylinder. The fuel injection valve 8 is an electromagnetic fuel injection valve which is energized by a solenoid to open the valve, and deenergized to close the valve. The opening of the fuel injection valve 8 is controlled by a drive pulse signal from the control unit 30. There is.

A spark plug 10 is provided in each cylinder of the engine 1, and a high voltage generated in an ignition coil 11 is sequentially applied to these cylinders through a distributor 12, whereby spark ignition is performed. Ignite and burn the air-fuel mixture. The ignition coil 11 is controlled in generation timing of a high voltage through a power transistor 13 attached to the ignition coil 11. 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.

A photoelectric type crank angle sensor 14 is built in the distributor 12, and a control unit 30 is controlled by a signal from the photoelectric type crank angle sensor 14.
At, the engine rotation 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.

Further, the automatic transmission 40 is provided with an N / P position sensor 16 for detecting a neutral position and a parking position, and a signal from the N / P position sensor 16 is inputted 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 roughly calculating as follows, and determines the effective fuel injection amount Te as a drive pulse signal. Output to the fuel injection valve 8. The basic fuel injection amount Tp = c × Q / N (c is a constant) is calculated from the intake air flow rate Q obtained from the voltage signal from the air flow meter 6 and the engine rotation speed N obtained from the signal from the crank angle sensor 14. At the same time, the effective fuel injection amount Te = Tp × α × K × Co is calculated from the air-fuel ratio feedback correction coefficient α, the air-fuel ratio learning control coefficient K, and various correction coefficients Co. Then, based on the relationship between the engine speed N, the effective fuel injection amount Te, the fuel injection timing and the ignition timing (so-called map) stored in advance, a drive pulse signal having a pulse width corresponding to the effective fuel injection amount Te. Is output to control the opening of the fuel injection valve 8. It should be noted that the control unit 30 stores several types of maps depending on whether the engine is cold, warmed up, etc., and a map according to each condition is selected.

Next, the control of the control unit 30 according to the present invention will be described with reference to the flowchart of FIG. In step 1 (indicated as STEP 1 in the drawing; the same applies hereinafter), the control state of the control unit 30 is reset to the state where the torque converter is not in the stalled 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 less than or equal to a predetermined value Vsp (V≤Vsp).
If V> Vsp, the process proceeds to step 3. If V> Vsp, the process proceeds to step 7. Here, step 2 and the vehicle speed sensor 15 correspond to the vehicle speed detecting means. In step 3, it is judged from the signal from the N / P position sensor 16 whether the shift position of the automatic transmission is in the neutral position or the parking position. If the shift position is not in the neutral position or the parking position, the shift position travels. If it is determined to be the shift position, the process proceeds to step 4, and if it is in the neutral position or the parking position, it is determined that the shift position is not the traveling shift position and the process proceeds to step 7.
Here, step 3 and the N / P position sensor 16 constitute a traveling shift position detecting means.

In step 4, the crank angle sensor 1
The engine speed N detected by 4 is read by the control unit 30. Further, 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, the intake air flow rate Q detected by the air flow meter 6, and the like. To be And
The engine load Tp is greater than or equal to a predetermined value TBLTPC (Tp ≧
TBLTPC), and Tp ≧ TBL
If TPC, proceed to step 6 and Tp <TBLT
If it is a PC, go to step 7.

Here, the high output state detecting means of the engine is constituted by the steps 4 and 5. In step 6, since it is determined in step 5 that the engine load is equal to or higher than the predetermined value, it is determined that the torque converter is in the stalled state. Then, it progresses 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 the stalled state.
Go to step 8. In Step 8, Step 6
If the torque converter is in the stalled state based on the determination result of step 7 and step 7, the control state of the control unit 30 is set to # TCFLG = 1, and then the process proceeds to step 9. On the other hand, if it is not in the stalled state, this flowchart ends.

In step 9, since it is determined that the torque converter is in the stalled state, the timer built in the control unit 30 starts counting up in order to measure the duration of the stalled state of the torque converter. (# TCTMR = # TCTMR
+1). Then, in step 10, the measured time TCTMR of the timer is set to a predetermined time T
CNG1 is reached (TCTMR ≧ TCNG1), and it is not reached (TCTMR <TCNG1).
To step 11, go to step 11 and if reached (TCTMR ≧ T
For CNG1), proceed to step 12.

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

Here, step 11 corresponds to one of engine output reduction correction means by ignition timing retard control. Subsequently, in step 12, when it is determined that the measurement time TCTMR has reached the predetermined time TCNG1 in step 10 and it is determined that the torque converter has been in the stall state for a long time, that is, the engine output due to the ignition timing retard. In the reduction correction control, when it is determined that the engine output cannot be suppressed below the predetermined value, the measurement time TCTMR reaches the predetermined time TCNG2 (> the predetermined time TCMR1 in step 11) (TCTMR ≧ TCNG).
2) and it is not reached (TCTMR <T
If it is determined that CNG2) is reached, the process proceeds to step 13, and if it is determined that (TCTMR ≧ TCNG2) is reached, the process returns to step 2.

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

Here, step 13 corresponds to one of the engine output reduction correction means by the fuel injection amount reduction control. In this embodiment, step 11 and step 13 are combined to form the engine output reduction correction means, but either one may be used. After that, this flowchart repeats the above steps, and when each condition is not satisfied in step 2, step 3, and step 5, this flowchart ends.

The engine output at the time of starting in steps 11 and 13 is suppressed as shown in FIG. 4, for example. The horizontal axis of FIG. 4 represents the engine rotation speed N, and the vertical axis represents the engine output (in this case, indicated by engine torque). The solid line shows the full-open performance curve of the engine 1 according to this embodiment, and the broken line shows the performance curve after the output reduction 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 reduction correction indicated by the broken line.

That is, at the time of starting, in order to prevent overheating due to intensification of the stall state of the torque converter due to the high output of the engine, the engine of the torque converter is set at a speed lower than the limit stall point G in the torque converter region. The full-open performance is controlled so as to pass on the curve indicated by the broken line. On the other hand, on the side of the rotational speed higher than the limit stall point G, the torque converter is in the coupling region, so overheating of the torque converter due to the stall does not occur, so the engine output reduction correction control is canceled and is shown by the solid line. It is designed to run on the full-open performance curve that the high-power engine originally had. Then, as described above, until the fixed time elapses immediately after the start (at an extremely low speed), the reduction correction control of the engine output is performed at step 11 first.
The ignition timing retard control is performed, and thereafter, when the fixed time has elapsed and the control cannot be suppressed only by the control of step 11, the fuel injection amount reduction control of step 12 is further performed.

Of course, when the vehicle speed reaches a predetermined value or higher, the engine output reduction correction control is canceled, and it goes without saying that the engine exhibits the original full-open output performance. Also, for example, when the vehicle is stopped and the shift position of the automatic transmission is in the forward or reverse position, the engine is fully opened with the foot brake applied, which is a situation that is difficult to think in normal use. However, since the engine output is reduced and corrected so as to match 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 (accelerating force) is the same as that when the load is not applied normally. Since the engine output is required to exceed the engine output during normal use, when a high-power engine is used, it is used in a state where the torque transmitted by the torque converter is exceeded, that is, in a region where the limit stall point is exceeded. Although the possibility increases, in the present embodiment, since the engine load is detected and the engine output reduction correction control is performed, it is not used in a state in which the transmission torque of the torque converter is exceeded.
Even under such a usage condition, the durability of the torque converter is not impaired.

As described above, in the engine control apparatus according to the present embodiment, the engine output is commensurate with the torque transmitted by the torque converter when the vehicle is started such that the stall state of the torque converter is severe and the medium fluid is overheated. Since the reduction 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, as the engine output suppressing means, the method of retarding the ignition timing and decreasing the fuel injection amount is used, but the engine output is suppressed by only one of them. Good. Further, for example, in addition to the method of stopping the fuel supply to at least one of the fuel injection valves or the method of reducing the intake air flow rate, a load is directly applied to the output shaft of the engine. Such a method may be used, and the engine output reduction correction control may be performed by any method.

[0030]

As described above, the engine control device according to the present invention is effective in stopping the vehicle and starting the vehicle.
Since the engine output can be reduced and corrected to an engine output that matches the torque transfer capacity of the torque converter, overheating of the medium fluid can be prevented and the durability of the torque converter can be ensured even when using a high-power engine. At the same time, it is possible to minimize the need to newly set the torque converter according to the output of the engine, and to reduce the production cost, etc., because the automatic transmission main body does not require complicated changes. Further, since the increase in vehicle weight can be eliminated, it is possible to improve the running fuel consumption and the like.

[Brief description of drawings]

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

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

FIG. 3 is a flowchart of the above.

FIG. 4 is a performance curve diagram showing the output characteristics of the output-controlled engine according to the above.

[Explanation of symbols]

 1 Engine 6 Air Flow Meter 8 Fuel Injection Valve 10 Spark Plug 14 Crank Angle Sensor 15 Vehicle Speed Sensor 16 N / P Position Sensor 30 Engine Control Unit 40 Automatic Transmission with Torque Converter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F16H 59/44 8009-3J

Claims (1)

[Claims] 1. A vehicle equipped with an automatic transmission equipped with a torque converter, at least a vehicle speed detecting means capable of detecting a vehicle speed below a predetermined value near a stop, and detecting that a shift position of the automatic transmission is at a traveling shift position. And a high output state detecting means capable of detecting that the engine output state is a high output state above a predetermined level, a vehicle speed below the predetermined level, a travel shift position, and a high output state above a predetermined level of the engine The output control apparatus for an engine, comprising: an output reduction correction unit that reduces and corrects the engine output when a state in which all of the above are detected continues for a predetermined time or longer.