JP2861507B2 - Idle speed control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle speed control system for an internal combustion engine, and more particularly to an idle speed control system for an internal combustion engine having an automatic transmission, which stabilizes the idle speed after shifting from a non-drive range to a drive range. The present invention relates to a rotation speed control device.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine, an idle speed is set as low as possible from the viewpoint of low fuel consumption. For this reason, in an internal combustion engine equipped with an automatic transmission, the slight increase in the load when shifting from the non-drive range to the drive range causes a decrease in the engine speed, so that the number of idle times becomes unstable, In severe cases, the engine may be stalled.

For this reason, it is conceivable that the shift from the non-drive range to the drive range is detected and the intake air amount and the fuel injection amount are increased to increase the engine output.
However, the effect on the load of the engine due to the drive range after the shift usually occurs not at the time of the shift but with a slight time delay from the time of the shift,
If the shift is detected and the engine output is immediately increased, the engine output will increase in a state where no load is applied to the engine, and the engine speed will rapidly increase.

Therefore, conventionally, the engine output is increased after a lapse of a predetermined time from the point when the automatic transmission is shifted from the non-drive range to the drive range, and the idle time is varied in accordance with the fluid temperature of the automatic transmission. 2. Description of the Related Art A rotation speed control device is known (Japanese Patent Application Laid-Open No. 62-131939).

[0005]

The shift position of the automatic transmission includes a non-drive range such as parking (P) and neutral (N), and a drive (D), low (L), second (2), and reverse. (R) and the like. The automatic transmission includes a torque converter that transmits the output of the internal combustion engine, a planetary gear unit as an auxiliary transmission that further increases the driving force of the torque converter, and a hydraulic control device.

FIG. 8 shows one example of the above-mentioned planetary gear unit.
FIG. 2 shows a configuration diagram of an example. C in FIG.₀, C ₁And C_TwoIs crack
J, B₀, B₁, B_TwoAnd B_ThreeIs brake, F₀, F₁
And F_TwoIndicates a one-way clutch.

FIG. 9 shows the operating state of each of the known planetary gear units in each range. In the figure, the black circles indicate the operation. "Reverse" means that the shift position is in the R range,
“First speed” to “fourth speed” are for the D range. Also, L
Range is fixed to "1st gear", 2nd range is "1st gear"
Although there is an upshift from "2nd speed" to "3rd speed", the upshift from "2nd speed" to "3rd speed" is not performed.

In FIG. 9, parentheses are in the L range or two levels.
In the case of a flange, the part in parentheses works in the D range
do not do. Therefore, as can be seen from FIG.
Shift from N range to D range which is drive range
If you do, "1st speed" brake B₁~ B_ThreeAre both made
It does not move, but R drive which is another drive range from N range
If the gear shifts to
Key B₁~ B_ThreeOf which B _ThreeIs activated.
You.

That is, when the driving range is the R range,
Reverse brake B to reverse the rotation speed of the output shaft
The operation of ₃ is added compared to the D range, and the addition of the operation of the reverse brake B ₃ further reduces the hydraulic pressure applied to the clutch and the brake, and the engagement time of the shift becomes longer than when the driving range is in the D range. It takes a long time for the load to act.

However, in the above-described conventional device, the delay time is varied according to the liquid temperature of the automatic transmission. However, when the liquid temperature is the same, regardless of whether the drive range is the D range or the R range, FIG. As shown in A), after the neutral switch (NSW) signal is switched from on (high level) indicating the non-drive range to off (low level) indicating the drive range, the state changes to FIG. In order to increase the engine output by executing the expectation control as shown by the solid line in FIG. 3 (C) after delaying by the time until the load is applied based on the shift from the N range to the D range shown by the solid line. The intake air volume is large.

Therefore, in the conventional apparatus, when the range is shifted from the N range to the D range, the idling speed becomes as shown in FIG.
Is controlled stably as shown by the solid line in FIG.
In the case of shifting to the range, the time until the load acts as shown by the broken line in FIG. 7B is longer than that in the case of shifting to the D range for the above-mentioned reason. It becomes later than the expected control execution start time at which the engine output is increased.

For this reason, in the conventional apparatus, when shifting from the N range to the R range, the engine output is increased without a load acting on the engine.
As shown by the broken line in (D), there is a problem that the idle speed rapidly increases (overshoot occurs) immediately after the start of execution of the anticipation control.

The present invention has been made in view of the above points,
An object of the present invention is to provide an idle speed control device for an internal combustion engine that solves the above-mentioned problem by changing a delay time from the time of a shift to increasing the engine output according to a drive range after the shift.

[0014]

FIG. 1 is a block diagram showing the principle of the present invention. As shown in the figure, in the present invention, when the internal combustion engine 11 is in an idle state, the shift from the non-drive range of the automatic transmission 12 to the first drive range for reverse or to the second drive range other than the first drive range. Is detected by the shift detecting means 13.

The delay time generating means 14 is a shift detecting means 1
When the shift to the first drive range is detected by 3, a delay time longer than the delay time when the shift to the second drive range is detected is generated.

The control means 15 controls the internal combustion engine 11 after the lapse of the delay time obtained by the delay time generation means 14 from the time when the shift detection means 13 detects the shift from the non-drive range to the first or second drive range. Engine power.

[0017]

According to the present invention, when the automatic transmission 12 is shifted from the non-drive range to the first drive range, a longer delay time elapses than when the automatic transmission 12 is shifted from the non-drive range to the second drive range. Since the engine output is increased after the shift from the non-drive range to the first or second drive range, the engine output is increased by adapting to the time when the load acts on the engine. Can be.

[0018]

FIG. 2 shows a system configuration diagram of an embodiment of the present invention. This embodiment is an example in which the internal combustion engine 11 is applied to a 4-cylinder 4-cycle spark ignition type internal combustion engine (engine).
1 shows a structural cross-sectional view of an arbitrary cylinder, and each unit of the system is controlled by an engine control computer (hereinafter, referred to as an ECU computer) 21 described later.

In FIG. 2, a piston 23 which reciprocates vertically in the figure is housed in an engine block 22. A combustion chamber 24 is connected to an intake manifold 25 via an intake valve 26, while an exhaust valve 27 is provided. Through the exhaust manifold 28. An ignition plug 29 is provided in the combustion chamber 24 so that a plug gap protrudes.

The upstream side of the intake manifold 25 is connected through a surge tank 30 to an intake pipe 31 commonly for the four cylinders. A throttle valve 3 is provided in the intake pipe 31.
3. Each of the air flow meters 32 is provided. The throttle valve 33 has a configuration in which the opening is adjusted in conjunction with the accelerator pedal, and the opening is detected by a throttle position sensor 34. An intake air temperature sensor 35 for measuring the intake air temperature is provided downstream of the air flow meter 32.

A bypass passage 36 bypassing the throttle valve 33 and connecting the upstream side and the downstream side of the throttle valve 33 is provided.
The idle speed control valve (ISC) whose valve opening is controlled by a solenoid
V) 37 is attached.

Numeral 38 denotes a fuel injection valve, which is provided in the ECU computer 2 (to be described later) in the air flow passing through the intake manifold 25.
Inject fuel according to the instructions in 1. The oxygen concentration detection sensor (O ₂ sensor) 39 is connected to the exhaust manifold 2.
8 is provided so as to protrude partially therethrough, and detects the oxygen concentration in the exhaust gas before entering the catalyst device. Reference numeral 40 denotes a water temperature sensor which is provided so as to penetrate the engine block 22 and partially project into the water jacket, and detects the temperature of the engine cooling water. An igniter 41 opens and closes a primary current of an ignition coil (not shown).

Reference numeral 42 denotes a distributor, a cylinder discriminating sensor 43 for generating a reference position detection signal for the engine crankshaft, and an engine speed signal of, for example, 30.
And a rotation angle sensor 44 generated for each ° C.

The output signal of the ECU computer 21 is input to the fuel injection valve 38 and the igniter 41, while
Necessary data is also transferred to the ECT computer 45.

The ECT computer 45 is a transmission control computer and is constituted by a microcomputer, for example, a vehicle speed signal from a vehicle speed sensor (not shown) for detecting a vehicle speed by rotation of an output shaft, and an automatic transmission 46 (FIG. 1). The gear position detection signal from the shift position switch 47 for detecting the position of the shift position (gear position) of
The data is input together with the data from the computer 21, the shift line is calculated, and based on the calculated shift line, the automatic transmission 46 performs the gear setting control (shift control).

An air conditioner switch 48 is a switch for detecting an operation state of the air conditioner.
1 to output a detection signal. The above-mentioned shift position switch 47 constitutes the above-mentioned shift detecting means 13, and the ECU computer 21 makes the delay time generating means 1
4 and the control means 15 are realized by software processing.
The ECU computer 21 has a hardware configuration as shown in FIG. 2, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 3, E
The CU computer 21 has a central processing unit (CPU) 50,
Read-only memory (R
OM) 51, a random access memory (RAM) 52 used as a work area, a backup RAM 53 for retaining data even after the engine is stopped, an input interface circuit 54, an A / D converter 56 with a multiplexer.
And an input / output interface circuit 55 and the like, which are connected to each other via a bus 57.

The A / D converter 56 has an intake air amount detection signal from the air flow meter 32, an intake temperature detection signal from the intake temperature sensor 35, a detection signal from the throttle position sensor 34, a water temperature detection signal from the water temperature sensor 40, and O
₂ The oxygen concentration detection signal from the sensor 39 is sequentially switched and input through the input interface circuit 54, and is converted from analog to digital, and is sequentially transmitted to the bus 57.

The input / output interface circuit 55 receives a detection signal from the throttle position sensor 34, a rotation speed signal corresponding to the engine speed (NE) from the rotation angle sensor 44, a detection signal from the air conditioner switch 48, and the like. It is input to the CPU 50 via the bus 57.

The CPU 50 executes various arithmetic processes based on each data input from the input / output interface circuit 55 and the A / D converter 56 via the bus 57, and transfers the obtained data to the bus 57. Through the output interface circuit 55, the ISCV 37, the fuel injection valve 38,
The idle speed is controlled to the target speed by controlling the opening of the ISCV 37, and the fuel injection time by the fuel injector 38, that is, the control injection amount per unit time is controlled by selectively outputting to the igniter 41 and the ECT computer 45. Control or ignition timing control by the igniter 41,
It also sends necessary data to the ECT computer 45. The ECT computer 45 has the same hardware configuration as the ECU computer 21.

In this embodiment, when shifting from the non-drive range (hereinafter, described as N range) to the R range or a drive range other than R range (hereinafter, described as D range as a representative), the engine immediately after the shift is used. In this case, the set delay time is changed in accordance with the time during which the load acts on the load, and the execution timing of the idle speed estimation control is optimized.

Since the idle speed estimation control is realized during the idle speed feedback control (ISC control) routine, the ISC control routine will be described first.

FIGS. 4 and 5 show a flowchart of an example of the ISC control routine. This ISC control routine
When the CU computer 21 is started, for example, at every 180 ° CA, it is first determined whether or not it is a starting time (step 1).
01), at the time of starting, the learning value DG stored in the backup RAM 53 is substituted for the feedback term DI (step 102). If it is not a starting time, it is determined in step 103 whether or not the ISC control F / B condition is satisfied, that is, the vehicle speed is higher than a vehicle speed sensor (not shown) in which the throttle valve 33 is fully closed by a signal output from the throttle position sensor 34. It is determined whether a condition such as being equal to or less than a predetermined value is satisfied. If the F / B condition is not satisfied, DI _OLD obtained last time in this routine is substituted for the feedback term DI (step 104). F /
If condition B is satisfied, the current engine speed NE
A deviation DLNT between the rotation speed and the target rotation speed NT is calculated (step 105).

Next, based on the following table, the DI correction amount DLDI
Is obtained (step 106).

[0034]

[Table 1]

Then, the correction amount DLDI is added to DI to obtain a new feedback term DI (step 1).
07). In this way, the engine speed NE becomes the target speed N
The feedback term DI is controlled to be T.

Hereinafter, ISC learning is performed. First, a smoothing process of the engine speed NE is performed by the following equation (step 108).

NESM _i = NESM _i−1 + (NE−NESM _i−1 ) / 32 Subsequently, NES _{i−1 is set} to NESM _i−1 for the next routine execution.
ESM _i is substituted (step 109), and NESM _i is substituted as an average NESM (step 110).

Next, the routine proceeds to step 111 in FIG. 5, and the average value NESM is set to ± 20 (r) with respect to the target rotational speed NT.
pm) is determined, and if not, the process proceeds to step 117 described later. When the engine speed NE is within the range, it is determined that the engine speed NE is stably converging to the vicinity of the target engine speed NT.
It is determined whether it is within the range between 0.4 (%) and DG + 3 (%) (step 112). If DI does not fall within the above range, the process proceeds to step 117 described later. If DI falls, DG> DI is satisfied and DLNT>
-20 is satisfied (step 11
3).

When it is determined in step 113 that the condition is satisfied, a value obtained by subtracting 0.4 (%) from the learning value DG is updated as a new learning value DG (step 114). If it is determined in step 113 that the condition is not satisfied, DG <DI is satisfied and DLNT is satisfied.
It is determined whether <20 is satisfied (step 11
5). If this condition is satisfied, the learning value DG will be 0.4
The value obtained by adding (%) is updated as a new DG (step 116). When the condition of step 115 is not satisfied, the process proceeds to step 117 without updating the learning value DG while keeping the previous value.

The outline of the above learning process is as follows. The learning value DG is updated so that the learning value DG approaches the feedback term DI when the engine speed NE is stably converging near the target speed NT. Is what it is.

Then, the process proceeds to a step 117, wherein a correction value CPMT of the expectation control which is a main part of the present invention is calculated by a subroutine described later. Then, the feedback term DI and the correction value CPMT are added, and the value DOP obtained thereby is finally output as the ISC duty ratio (step 118), and this ISC control routine ends.

The aforementioned ISCV 37 is duty-ratio controlled to an opening corresponding to the DOP, and controls the amount of air passing through the bypass passage 36 in an idle state.

Next, an estimation control routine for calculating the correction value CPMT will be described with reference to the flowchart of FIG. In FIG. 6, first, the ECU computer 21
Neutral switch (NSW) from shift position switch 47 input via T computer 45
It is determined whether the signal is on (ie, N range) or off (ie, D range or R range) (Step 2).
01).

When the NSW signal is inverted from on to off, a delay time T _D at which the load starts to act on the engine when shifting from the N range to the D range is set (step 2).
02). When the NSW signal is turned on within this delay time T _D , that is, when the signal is shifted to the N range again, the correction value CPM
This routine ends with T remaining at the previous value (steps 203 and 204).

On the other hand, if the delay time T _{D has} elapsed while the NSW signal is not turned on and remains in the off state, step 2
03 to 205, the reverse signal (R) input from the shift position switch 47 of the automatic transmission 46 to the ECU computer 21 via the ECT computer 45.
It is determined whether the signal is in the D range or the R range depending on whether the EV signal is on.

The REV signal is a signal that is observed on (e.g. a high level) when the automatic transmission 46 is shifted to the R range, when the off time has elapsed the delay time T _D, D from the N range The shift to the range is determined (step 205). The correction value CPMT is increased by the expected amount α (step 206), and this routine ends.

Therefore, after the lapse of the delay time T _D from the shift from the N range to the D range, the correction value CP
Since the MT has increased by the expected amount α, the ISCV
37, the opening control value DOP increases by the expected amount, and the ISCV
The opening of 37 is increased, and the engine output increases due to an increase in the amount of intake air during idling (that is, anticipation control is executed). By the above-mentioned step 206, the control means 1
5 is realized.

[0048] On the other hand, when the REV signal in step 205 is determined to be ON, it is determined from the N range shift to the R range, to extend the delay time is set to a predetermined delay time T _R (Step 207). Time sum of the predetermined delay time T _R is the delay time T _D and T _R is approximately equal to the time from the N range to the load on the engine from the shift point when the shift to the R range is applied Is set. The above steps 201 to 207 correspond to the processing corresponding to the delay time generating means 14.

[0049] Subsequently, when the REV signal is determined to off before the delay time T _R course of above (Step 20
8, 209), it is determined whether or not the NSW signal is on (step 210). When the NSW signal is on, it is determined that the shift to the N range is further performed, and the correction value CPMT is kept at the previous value (that is, the expected value). Without executing the control), this routine ends.

On the other hand, when the NSW signal is off at step 210, it is determined that the shift to the delay time T _R in the D range is performed, the correction value C proceeds to step 206
Increased PMT only expected amount alpha, to perform the immediately anticipated control without waiting for the elapse of the delay time T _R.

Meanwhile, when the REV signal is determined to have the delay time T _R course remain in the ON state (Step 2
08) The process proceeds to step 206, where the correction value CPMT is increased by the expected amount α. Therefore, when the shift is made from the N range to the R range, the expectation control is executed after a delay time of (T _D + T _R ) has elapsed from the shift detection time.

When it is determined in step 201 that the NSW signal has not been inverted from on to off,
It is determined whether the NSW signal is inverted from off to on (step 211). If the NSW signal is not inverted from off to on, this routine is terminated.

On the other hand, when it is determined that the NSW signal is inverted from off to on, the correction value CPMT is reduced by the expected amount α (step 212), and this routine is terminated. Therefore, when the driving range is shifted to the N range,
Immediate control is executed immediately after the shift is detected.

[0054] Thus, according to this embodiment, on 7, when at time t ₁ from the N range to that shifted to the R range, NSW signal as shown in FIG. 7 (A) at time t ₁ inverted to the oFF from, REV signal as shown in (B) in the subsequent have the delay time T _D is reversed from oFF to oN.

Shift time t ₁ from N range to R range
After, immediately after time t ₃ when the time of the sum of the delay time T _D and T _R as shown in FIG. 7 (C), the load begins to act on the engine. After the shift from the N range by the above-described conventional apparatus to R-range, because running the expected control delay time T _D elapsed time t ₂ as indicated by a broken line in FIG. 7 (D), idle speed the drawing (E) As shown in FIG.

[0056] In contrast, since running a correction value CPMT at time t ₃ as shown by a solid line in the large only expected amount α expected control in FIG. 7 (D) in the present embodiment, and FIG. (E) As shown by the solid line, the execution timing of the expectation control is optimal, so that the overshoot of the idle speed can be prevented.

The present invention is not limited to the above-described embodiment. For example, the ISCV 37 may be configured to control the opening and closing of a valve by a stepping motor. In this case, the CP
MT is the number of steps.

[0058]

As described above, according to the present invention, when shifting from the non-driving range to the reverse range, the expected control is performed after a longer time delay than when shifting from the non-driving range to a driving range other than the reverse range. And the engine output is increased by adapting to the time during which the load acts on the engine, so that when shifting from the non-drive range to the reverse range, the overshoot of the idle speed can be prevented. It has.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a system configuration diagram of an embodiment of the present invention.

FIG. 3 is a diagram showing a hardware configuration of an ECU computer in FIG. 2;

FIG. 4 is a flowchart (part 1) of an example of an ISC control routine;

FIG. 5 is a flowchart (part 2) of an example of an ISC control routine;

FIG. 6 is a flowchart of a prospective control routine according to an embodiment of the present invention.

FIG. 7 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 8 is a configuration diagram of an example of a planetary gear unit.

9 is a diagram showing a state of an operating state in each range of the planetary gear unit of FIG.

FIG. 10 is a time chart for explaining the operation of the conventional device.

[Explanation of symbols]

Reference Signs List 11 internal combustion engine 12, 46 automatic transmission 13 shift detecting means 14 delay time generating means 15 control means 21 ECU computer 37 idle speed control valve (I
SCV)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-131939 (JP, A) JP-A-2-238148 (JP, A) JP-A-62-131939 (JP, A) JP-A 60-131939 206945 (JP, A) JP-A-5-215221 (JP, A) JP-A-5-79365 (JP, A) JP-A-57-139646 (JP, U) JP-A-61-157141 (JP, U) (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 29/00-29/06 F02D 41/00-41/40

Claims (1)

(57) [Claims] 1. A shift detecting means for detecting a shift from a non-drive range of an automatic transmission to a first drive range for reverse or a second drive range other than the first drive range in an idle state of the internal combustion engine. When the shift detection means detects a shift to the first drive range, a delay that generates a delay time that is relatively longer than the delay time when the shift to the second drive range is detected. A time generating means, and after the delay time obtained by the delay time generating means from the time when the shift from the non-drive range to the first or second drive range is detected by the shift detecting means, Control means for controlling the engine output to increase so as to increase the engine output.