JPS59206644A - Method of controlling idling rotational frequency of internal-combustion engine with automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the rotational frequency of an engine from rising at the time of gear shifting, by immediately closing a by-pass for a throttle valve when a gearshift is put back into the neutral position after gear shifting to a non-neutral position from a state wherein the by-pass is closed and the gearshift is in the neutral position. CONSTITUTION:After it is judged in the step S22 of a control routine for an air control valve that a gearshift is in the neutral position, it is judged in a step S26 whether a flag F is set or the gearshift is put into the neutral position from another position. If the flag F is set, the flag is reset in a step S28. After that, it is judged in a step S30 whether a flag X is set. The flag X is set when the gearshift is in the neutral position and the air control valve is closed to shut a by-pass. If the flag X is set, the air control valve is closed in a step S58. The valve is immediately closed when the gearshift is put into the neutral position from another position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the idle speed of an internal combustion engine using an automatic transmission, and more particularly, the present invention relates to a method for controlling the idle speed of an internal combustion engine using an automatic transmission. The present invention relates to an idle rotation speed control method for controlling the total rotation speed to a target rotation speed.

In recent internal combustion engines, is the idle speed the starting point for improving fuel efficiency? Because they tend to be set low, especially in small and lightweight internal combustion engines, even a slight load such as turning on the 7-beam or driving the electric fan at full speed during idling will cause a drop in engine speed, and the engine speed will decrease when idling. The engine speed may become unstable. Furthermore, if deposits are deposited on the throttle valve due to changes over time, the engine speed may gradually decrease and the engine speed during idling may become unstable.

For this reason, a detour is provided to bypass the throttle valve, and when the throttle valve is fully closed, that is, when the engine is idle,
A method is known in which the air flowing through this detour is ftk controlled to control the engine rotational speed to the full target rotational speed. An air flow control valve whose opening degree is controlled by a step motor is installed on this detour, and the target air flow is controlled by controlling the opening of the air flow control valve according to the engine load and shift position. It is supplied to the engine combustion chamber, and the engine speed is controlled to be close to the target speed. In addition, in an operating state other than the throttle valve being fully closed, that is, in an operating state in which the throttle valve is opened to a predetermined value, the opening degree of the air amount control valve is held constant, and the amount of air passing through the throttle valve and the air passing through the detour are controlled. Is the air-fuel mixture supplied to the combustion chamber of the engine at a value close to the stoichiometric air-fuel ratio, depending on the amount of fuel injected from the fuel injection valve? It is made to be taken.

However, in this conventional method, since the opening degree of the air amount control valve is controlled by a step motor, there are problems in that the control becomes complicated and the cost increases. For this reason, an air control valve that opens and closes by turning on and off electric current is installed in the detour, and the engine speed is controlled within a predetermined range by simple control of opening and closing the air control valve. When used in an internal combustion engine with a biased power bias, if the shift position is shifted from the neutral range (N range) to the drive range (D range) with no electrical load applied to the engine, that is, with the detour cut off, the torque will increase. Since the load of the converter is added to the engine and the engine speed decreases, a detour is usually provided. If the D range is changed back to the N range, the detour will not be shut off unless the air control valve closing condition is met, so there is a problem in that the engine speed will increase until the air control valve closing condition is met. . Note that even if the electrical load is removed from the state where the electrical load is applied, the engine rotational speed does not increase much because the alternator's power generation load is added to the engine.

The present invention has been made to solve the above problems, and is equipped with an automatic transmission that does not increase the engine speed by changing the shift position when the idle speed is fully controlled by simple control of cutting off the communication of the detour. An object of the present invention is to provide a method for controlling the idle speed of an internal combustion engine.

In order to achieve the above object, the present invention has a detour that bypasses the throttle valve and communicates the upstream side of the throttle valve and the downstream side of the throttle valve when the engine speed reaches the upper limit of a preset range. When the road is completely shut off and the engine speed is below the lower limit of the predetermined range, the detour road is fully opened and the engine speed during idling is controlled to be within the predetermined range. In terms of the engine idle speed control force, when the shift position is in the neutral range and the front R self-rotation path is blocked, when the shift position is shifted to a range other than the neutral range and then shifted to the neutral range, the detour is It is designed to block W6.

According to the configuration of the present invention, when shifting from a state in which the detour is blocked in the N range to a range other than the N range and then returning to the N range, the detour is immediately blocked, so the engine rotational speed at the time of the shift is This has the effect of preventing an increase in .

An example of an internal combustion engine to which the present invention is applied will be explained in detail based on FIG. An intake temperature sensor 2 is installed downstream of the air cleaner 1 to detect the entire temperature of intake air and output an intake temperature signal. A throttle valve 4 is arranged downstream of the intake temperature sensor, and this throttle valve 4
A throttle switch 6 is installed which is interlocked with the throttle valve and turns off when the throttle valve is fully closed and turns off when the throttle valve opens. A surge tank 8 is provided downstream of the throttle valve 4, and a pressure sensor 1o is attached to the surge tank 8 to detect the intake pipe pressure downstream of the throttle valve and output an intake pipe pressure signal. . A detour 3 with one end opening upstream of the throttle valve 4 and the other end opening into the surge tank 8 is provided, or a detour 3 is provided to bypass the throttle 3-P4. In particular, an air control valve 5 is installed which completely communicates with and shuts off the ρ detour 3. This air control valve 5 may have a small flow rate that can compensate for a decrease in the idle rotation speed due to the electrical load. The surge tank 8 is communicated with a combustion chamber 14 of the engine via an intake manifold 12. A fuel injection valve 16 is attached to the intake manifold 12 for each cylinder. A combustion chamber 14 of the engine is communicated via an exhaust manifold 7 to a catalytic converter 9 filled with a three-way catalyst.

Further, a water temperature sensor 20 is attached to the engine block to detect 17 the volume of water at the cold end of the engine and output a water temperature signal. The tip of a spark plug 22 is exposed in the combustion chamber 14 of the engine, and a distributor 24 is connected to the spark plug 22. distributor 2
The engine rotation speed sensor 26, which is connected to the pickup 23 fixed to the VF6 distributor housing and the 7b rotor 25 identified to the taste distributor shaft, is defeated. The engine rotation speed sensor 26 outputs a crank angle signal to the control circuit 30 at, for example, 30° and μ. In addition, 34 is a sensor 0 that detects residual acid production in exhaust gas 1-7 and outputs an air-fuel ratio signal, and 35 is a neutral switch that detects the neutral position by being defeated by the output shaft foot lever of the final stage of the transmission. be.

As shown in FIG. 2, the control circuit 30 includes a central processing unit (C
PU) 36, read-only memory (ROM) 38
, random access memory (RAM) 40, backup RAM (BU-'RAM) 4.2, input/output port (■
10) 44, Analog-to-digital converter (ADC) 46
It also includes buses such as a data bus and a control bus that connect these. In I 1044,
The speed control signal, crank angle signal, air-fuel ratio signal, throttle signal output from the throttle switch 6, and neutral signal output from the 2' neutral switch are input, and the air control valve 5 is inputted via the jump circuit. ′! r - air control valve control signal for opening and closing, fuel II injection signal and igniter W for controlling the opening and closing time of the fuel injection valve 16;
An ignition signal is output that controls the on-off time of the plug. Further, an intake pipe pressure signal, an intake air temperature signal, and a water temperature signal are input to the AIT) C46 and converted into digital signals.

The above crank angle signal is passed through a waveform shaping circuit to I70
44, and a digital signal representing the engine speed NE is formed from this crank angle signal. The on/off signal (throttle signal) from the throttle switch 6 is sent to a predetermined bit position of I1044 and temporarily stored. The CPU 36 is also provided with first and twentieth counters that are incremented at predetermined time intervals.

Next, the present invention is carried out using the engine as described above [
An example in the case of 7 will be described. In this embodiment, the time from when the engine speed reaches or exceeds the upper limit of a predetermined range until the detour is cut off is shortened depending on the size of the difference between the engine speed and the upper limit. The time required to connect the detour after the engine speed falls below the lower limit of the predetermined range is shortened depending on the size of the difference between the engine speed and this lower limit. In order to avoid complication, this embodiment will be explained using several representative values that are the most inconvenient, but the present invention The optimum value is selected for each type of engine without being limited to the numerical value of ゛.

Figure 3 is 32m3el! This shows an interrupt routine that is executed every time, and the count values of the first counter and the second counter are incremented by this interrupt routine. In step s2, the count value c1 of the first counter is incremented by 1, and in step S8, the count value c2 of the second counter is incremented by 1. In step S4, it is determined whether or not the count value c1 is greater than or equal to the maximum value MAX. If it is greater than or equal to the maximum value MAX, step s
6, the count value C1 is set to the maximum value MAX. Similarly, in step 8.10, it is determined whether the count value C2 is greater than or equal to the maximum value MAX, and if it is greater than or equal to the maximum value MAX, the count value C2 is set to the maximum value MA in step S12.
Let it be X. As a result, the count values of the first counter and the second counter are incremented by 1 at 32m5ec#+, and since the count values are limited to the maximum value MAX, overflow is prevented.

FIG. 4 shows the stenosis control valve control runn executed every 32 ms, ec. If it is determined in step S20 that the full size position is not in the N range as to whether or not the perforation control valve one control moxibustion condition is established, step S8
After setting the flag F in step S24, the process advances to step S34.

On the other hand, when it is determined in step S22 that the shift position is in the N range, the flag F is determined in step 3.26.
It is determined whether the set awn has been set, that is, whether it has been shifted from a range other than the N range to the N range. When flag F is reset, the first step S34
If flag F is set, proceed to step S.
28, the flag F"k is reset (after 7, step S30
It is determined whether flag X is set. This flag X is set when the shift position is in the N range and the air control valve is closed.
At 58, the air control valve is closed. Therefore, if the air control valve was closed during the previous N range, the air control valve will be closed immediately when the range is shifted to the N range from a range other than the N range.

When it is determined in step S30 that the flag X has not been reset, the engine speed N is determined in step S34.
It is determined whether or not F exceeds 950 r, n, m. Engine rotation speed NE is 950 r, p, m.

If it is determined that Clkl has increased, the count value Clkl is incremented in step S36, and the count value Clkl is incremented in step S36.
8 and 1777 rotations NE is 78 Or, n, m.

If it is determined that it is less than 63 (r, p, m, At the same time, check whether the engine revolution aNE is less than 55 Or, p, m in the engine rotation speed NE at step S46. If C2 is set to O, and the engine speed NE is less than 55Or,p,m, (the count value C2 is incremented by 1 at main step 848, U
As a result of the above, the count value C1 and the count value C2 indicate that the engine rotation speed is within the predetermined Q↓ range (630r, p, m.

<NE<78 Or, p, m, ) and @O(・
The first region (
780r, p, m, ≦NE≦95 Or, p, m
, ) and a second region where the engine speed is below the lower limit of the predetermined range (550r,p,m,≦NE≦63O
r, p, m, ), 3 from the routine box in Figure 3.
The count value C1 is incremented every 277 isec, and when the engine speed is in the third region (NE>9F) Or, p, m,) exceeding the first region, the count value C1 is determined as 32m5t=32m5t in step S2. The count value C2 is incremented every 32m5ec in step S36, and the count value C2 is incremented every 32m5ec in step S36.
m, ), it is incremented to 32m1Iec# in step S8 and 32m5e in step S48.
Incremented to c@.

As a result of incrementing the count value as described above, the third area has a longer time than the first area, that is, 32 m.
The count value is incremented in a time shorter than 5ec, and in the fourth region the count value is incremented in a time shorter than the second region, that is, 3ec.
The count value is incremented in a shorter time than 27n8·C.

In the next step S50, the count value C2 is changed to a predetermined value A(
For example, it is determined whether or not it exceeds a predetermined value A. If it exceeds a predetermined value A, the air control valve is opened in step S52, and the flag X is reset in step S54. Also, in the next step S56, it is determined whether the count value 01 exceeds a predetermined value B (for example, 48)! If the predetermined value B is exceeded, the air control valve is closed at step 85F.

Open and close the air control valve as above, step-S
At 60, shift position or N range position, step S
At 62, it is determined whether the air control valve is closed. Then, when the air control valve is closed and closed, the flag X is set in step S64, and in other cases, the flag is reset to X' in step S54. The timing will be explained using Fig. 5. Here, when the hunting is shifted from the N range to the D range with the air protection control valve closed, the flag F is set after a predetermined time. The air control valve is opened a predetermined time after flag F is set. Next, when shifting from the D range to the N range, the air control valve is immediately closed even if the air control valve closing condition is not satisfied. Conventionally, as shown by the broken line, when shifting to D range or bN range, the engine speed increased the day before.
As described above, by controlling m-1-, the engine speed becomes indicated by a solid line.As explained above, according to this embodiment, the larger the reduction in the engine speed, the more the detour will be taken. Air is quickly supplied through 7, and it is possible to reduce the idle rotation speed to 150,015 m.

Note that although the 'PJ1 diagram shows an engine that determines the basic fuel injection amount based on intake pipe pressure and engine speed, the present invention is limited to this size engine.
It is also possible to apply this invention to an engine in which the basic fuel injection amount is determined based on the intake air pressure per engine revolution and the engine rotational speed, or to a fuel injection type engine.

4. Page 15i Simple explanation, Figure 1 is a schematic diagram showing an example of an engine to which the present invention is applied, Figure 2 is a block diagram showing the control circuit of Figure 1, and Figure 3 is a schematic diagram showing an example of an engine to which the present invention is applied.
The figure is a flowchart showing the interrupt routine every 32 m B B c in the embodiment of the present invention, Fig. 4 is a flowchart showing the control routine of the air control valve of the above embodiment, and Fig. 5 shows the opening/closing timing of the air control valve, etc.・It is a line diagram shown.

3...Detour, 5...Air control valve, 6...Throttle switch, 10...Pressure sensor, 3()...Control circuit, 37...Neutral switch.

Claims (1)

[Claims] (1) When the engine speed exceeds the upper limit of the preset P91 range, the system bypasses the throttle valve and shuts off the detour that communicates with the upstream side of the throttle valve and the downstream side of the throttle valve, and reduces the engine speed. An idling speed control method for an internal combustion engine equipped with an automatic transmission, which completely shuts off the detour and opens the engine speed during idling to a value within the predetermined range when the value falls below the lower limit of the predetermined range. , the detour is completely blocked when the shift position 7jE is in the neutral range and the detour is cut off to a range other than the neutral range, and the detour is further shifted to the neutral range. A method for controlling the idle speed of an internal combustion engine with an automatic transmission.