JPS59136541A - Idling-speed controlling method - Google Patents

Abstract

PURPOSE:To prevent unnecessary movement of an idling-speed control valve disposed in a by-pass passage by-passing a throttle valve, by changing the rate of increment and decrement in the duty ratio of a pulse signal applied to the idling- speed control valve (ISC valve) according to the operational conditions of an engine. CONSTITUTION:According to the idling-speed controlling method of this invention, a linear solenoid type ISC valve 13 is provided in a by-pass passage 11 by- passing a throttle valve 12, and the duty ratio of a pulse signal applied to a solenoid coil of said valve 13 is calculated by a processing circuit 14 according to the operational conditions of an engine. Further, sticking and slipping of said linear solenoid is prevented by increasing or decreasing the duty ratio of the pulse signal periodically. The ISC valve 13 is controlled by setting the rate of increment and decrement in increasing or decreasing the duty ratio periodically at two values greater than a prescribed duty ratio D (for instance, 30%) and smaller than the prescribed value (for instance, D + or -16%, D + or -8%).

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a linear solenoid type idle speed control valve (hereinafter referred to as
This invention relates to an idle speed control method when using an ISO valve (referred to as an ISO valve).

Generally, the idle speed of a gasoline engine is controlled by changing the opening degree of an rSC valve in a bypass passage that bypasses a throttle valve. Also, the idle speed changes significantly with a slight change in the valve opening, partly because there is no vehicle running load on the engine.

Therefore, it is necessary to control the idle rotation speed with high precision, and for this purpose, it is necessary to control the opening of the ISO valve delicately and with high precision, so it is recommended to use a pulse motor to control the drive of the ISC valve. Conceivable. In that case, the product price of the l59-valve including the control circuit would be extremely high, so the linear solenoid type lS
C valve is used. However, when a linear solenoid-type ISC valve is used, the sliding resistance of the moving part of the ISC valve causes a lack of mechanical clarity, especially for very small movements, and the linear solenoid moves in a stepped manner. A so-called stick-slip phenomenon occurs, which causes the valve opening degree of the ISC valve to follow a slight change in the duty ratio of the pulse signal to the solenoid coil, resulting in a drawback that it may not be as much as 1q.

Therefore, as a countermeasure, the duty ratio of the pulse signal corresponding to the valve opening degree is increased or decreased by an arbitrary range, for example, as shown in Fig. The above stick-slip phenomenon can be prevented by vibrating the ISC valve with the same average current value that does not change the opening degree, so that the ISC valve can move smoothly even with slight changes in current, that is, changes in duty ratio. I'm suppressed 11 times.

However, even if the duty ratio of the pulse signal is controlled in this way, in the high flow region of the intake air amount where the pulse signal average current value is large and the stick-slip phenomenon is difficult to occur, the ISC valve can control the duty ratio at any width. As it moves in response to increases and decreases, the change in the intake air becomes large, which not only increases hunting of the engine speed, but also causes the measuring plate of the air flow meter to move too much, making it difficult to control the engine by computer, such as fuel injection. There was a drawback that quantity control etc. became unstable.

[Objective of the Invention] The object of the present invention is to periodically increase/decrease the duty ratio of the pulse signal supplied to the solenoid coil of a near solenoid type ISC valve, and to change the increase/decrease according to the operating state of the engine at an idle rotation speed. The object of the present invention is to eliminate the drawbacks of the prior art by providing a control method.

[Structure of the Invention] To achieve the above object, the gist of the invention is to provide a bypass solenoid for changing the flow area of the bypass passage that bypasses the throttle valve and supplies air to the engine. A roll valve is provided in the idle speed control valve 1, and the duty ratio of the pulse signal supplied to the solenoid coil of the idle speed control valve is calculated according to the operating state of the engine,
In the idle rotation speed control method, the duty ratio of the pulse signal is periodically increased or decreased to suppress the stick-slip phenomenon of the linear solenoid, wherein the increase or decrease when the duty ratio is periodically increased or decreased. The idle speed control method is characterized in that the amount is changed or decreased depending on the magnitude of a duty ratio calculated according to the operating state of the engine.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows an electronic fuel injection device for an automobile engine and an idle speed control device incorporated therein.

That is, 1 is a cylinder of the engine 2, 3 is an exhaust manifold connected to the exhaust port 5 of each cylinder of the cylinder head 4, 6 is an intake manifold connected to the intake port 7 of the cylinder head 4, and the intake manifold 6 is connected to the exhaust port 5 of each cylinder. A surge tank 8 is connected to the surge tank 8. An air flow meter 9 that detects intake air from an air cleaner (not shown) is connected to the surge tank 8, and an intake air temperature sensor that detects the intake air temperature is connected near the air flow meter 9. 10 is installed. 11 is a bypass passage for intake air that bypasses the throttle valve 12 that controls the intake air m sent to each cylinder via the surge tank 8, and 13 is a bypass passage for intake air flowing through this bypass passage 11. It is a near solenoid type ISC valve that is adjusted, and the third one is an electronic controller.
The opening degree is controlled by an arithmetic processing circuit 14 as shown in the figure. 15 is parallel to the bypass passage 11.
Another bypass passage, the bypass passage 15, is controlled to open or open by an air valve 16 that is opened when cold. 17 is a fuel injection valve that controls the injection amount of fuel supplied from a fuel injection pipe connected to the vicinity of the tip of the intake boat γ side of the intake manifold 6; 18 is a throttle sensor that detects the fully open state of the throttle valve 12; The former fuel injection valve 17 is driven and controlled by the arithmetic processing circuit 14,
The latter throttle sensor 18 is connected to output a signal indicating a fully open throttle state to the arithmetic processing circuit 14. 19 is an oxygen sensor installed in the exhaust manifold 3 and detects the amount of oxygen remaining in the exhaust gas and generates an air-fuel ratio signal; 2o is a water temperature sensor that detects the cooling water temperature of the engine 2; and 21 is an oxygen sensor that detects the speed of the vehicle. Vehicle speed sensor to detect, 22
is an air conditioner switch that detects whether the air conditioner is operating or not.
In the case of an A-1-matic transmission vehicle, 23 is a neutral switch that detects whether the engine lever is in the neutral position or the parking position, and is connected to send each detection signal to the arithmetic processing circuit 14. 24 is a distributor that applies high voltage to each spark plug 25 of the engine 2 at a predetermined timing;
It is connected to an igniter 26 equipped with an ignition coil controlled by the arithmetic processing circuit 14, and furthermore, the disc 1 to the reviewer 24 receives a pulse signal that rotates in synchronization with the crankshaft of the engine 2 and is proportional to the rotation. A rotation angle lens 27 that generates a rotation angle lens 27 and a cylinder discrimination sensor 28 that detects the top dead center of a specific cylinder are provided, and each detection signal is sent to an arithmetic processing circuit 1.
It is connected to send to 4.

The arithmetic processing circuit 14 is composed of a microcomputer as shown in FIG. 3, and includes a CPU 30, a fixed memory ROM 31 in which control programs and various data necessary for arithmetic processing are stored, a temporary memory (7) RAM 32, and a key switch. It is equipped with a backup RAM 33 whose power is backed up by a battery so that the memory is retained even after the memory is turned to A, each input/output capo 1-34, 35, and output ports 36, 37, and each element is connected by a pass line 38. , each input/output port 34, 35 and each output port 36, 37 directly or to the Bazza circuit 39, 43, multiplexer 44.
, A/D converter 45, comparator 46, shaping circuit 47
, the detection signals of the various sensors and the drive signals of the ISC valve 13, fuel injection valve 17, and igniter 26 are connected via drive circuits 48 to 50. In addition, 51 in Figure 3
represents a clock circuit that sends a clock signal serving as a control timing to the CPU 30, ROM 31, RAM 32, etc. at predetermined intervals.

Here, to explain the operation of the electronic fuel injection device in detail, first, the CPU 30 inputs and outputs data on the intake air amount detected by the air flow meter 9 and the engine rotation speed detected by the rotation angle sensor 27. The basic fuel injection m is calculated from these data. And this basic fuel injection! ) lPi is corrected according to each of the intake air temperature detected by the intake air temperature sensor 10 and the cooling water temperature detected by the water temperature sensors 1 and 20,
Further, the actual fuel injection amount is calculated by correcting the residual oxygen concentration in the exhaust gas detected by the oxygen sensor 19. Based on this actual fuel injection amount, the arithmetic processing circuit 1
4 controls the fuel injection valve 17 to perform fuel injection that matches the operating condition of the engine 2.

Similarly, the optimum ignition timing is calculated based on the engine speed, intake air amount, etc. using, for example, a data map in the ROM 31, and based on this, an ignition timing signal is sent to the igniter 26). Ignition timing control is performed according to the operating state of the engine.

The idle speed of the engine 2 is controlled by flowchart 1 of the "ISO calculation" program 80 shown in FIG.
This is done by the process shown in .

This program is stored in the ROM 31 in the form of a part of the main routine or a subroutine, and when processing is started at a predetermined timing, first in step 81 data for l5C3l calculation such as ISO learning values is read from the backup RAM 33. υ is transferred to the RAM 32, and in step 82, it is determined whether the ISC feedback condition is satisfied based on the starter, water temperature, vehicle speed, opening/closing state of the throttle valve 12, etc., and if the SC feedback condition is satisfied. , -, [YESj], and in step 83, the target value NF of the idle rotation speed is determined based on the shift state of the air conditioner and the change lever.

Furthermore, in step 84, elements for determining the duty ratio of the pulse signal supplied to the SC valve 13, an integral term DI and a proportional term DP, are calculated from the difference between the current carrot rotational speed NE and the target value NF. At the same time, in step 85, in order to determine the duty ratio, an expected item D corresponding to the load applied to the engine 2 during idle rotation is determined based on the operating state of the air conditioner 22, the shift position of the change lever, etc.
Perform 1 arithmetic on T and calculate each of these terms DI.

DP1D]-, the duty ratio of the ISCSC pulp 1 rib pulse signal according to the current operating state of the engine is calculated. Then, in step 86, the sum of the current learning value DG, the integral term DI, and the proportional term DI) is compared, and DG is updated based on the comparison result.
In step 87, the duty ratio determined in the previous step 85 is set to R, while in step 82 (15 and ISO
If it is determined that the feedback conditions are not satisfied, in step 88, the duty ratio of the pulse signal for driving the ISO valve 13 during non-feedback control is calculated according to the starter, water temperature, vehicle speed, opening/closing state of the throttle valve 12, etc. , this calculated duty ratio is transferred to the register in step 87. Then, based on the pulse signal of this duty ratio, processing of the "rlsc output" routine described later is performed, the ISO valve 13 is driven and controlled, and the intake air amount is controlled.

Next, FIG. 5 moves to flowchart 1 showing the "ZSC output" routine 90 of the main control program of the present invention. The process will be explained below with reference to FIG.

The duty ratio calculated by the above-mentioned ``rlsc calculation'' program 80 is set to an arbitrary range; in this embodiment, when the duty ratio does not reach 30%, it is ``D ± 16%'', and when the duty ratio is 30% or more, is a flowchart of a control program when the duty ratio is periodically increased or decreased in the width of "D±8%", and FIG. 6 shows this when the duty ratio is 025
% and 50%. FIG.

This routine 90 starts processing, for example, every 20 m5ec, and first, in the slap 91, at 20 m5ec, the least significant bit BO of the increment 1-turnf i~timer is set to "1".
”, and if it is “1”, the process moves to step 92 in order to increase the due-eye ratio.

In step 92, the duty ratio i'i'l-If'
It is determined whether the value is 30% or more, and if it is 30% or more, the process moves to step 93. Then, in step 93, the duty ratio is set to a small value of "D+8%", which is a small increase amount, and the process proceeds to step 94.

In step 94, the ISO valve 13 is driven at the duty ratio determined in the previous step.

Meanwhile, in step 92, the program 8
If it is determined that the duty ratio calculated in step 0 does not reach 30%, the duty ratio is set to rD in step 95.
The ISC valve 13 is driven in step 114 by increasing the value to a large value of "+16%".

Also, in step 91, the least significant bit BO of the soft timer
If it is determined that is rOJ, the process moves to step 96 to reduce the duty ratio, and it is determined whether the calculated value of the duty ratio is 30% or more.
In the above case, the process moves to step 97.

In step 97, the duty ratio is set to "D-8%".
The process proceeds to step 94 by setting the amount of decrease to a small value.

In step 94, the ISO valve 13 is driven to the duty ratio determined in step 97.

On the other hand, if it is determined in step 96 that the duty ratio does not reach 30%, in step 98 the duty ratio is set to a large value of "l'D - 16%", and in the subsequent step 94, the process proceeds to step 98. The ISO valve 13 is driven at the duty ratio determined.

The pulse signal supplied to the ISO valve 13 through the above processing is as shown in FIG. 6 when the duty ratio calculated by the RLSC program 80 is, for example, 25% and 50%.

In other words, if the duty ratio is 25% and does not reach 30%,
It increases and decreases periodically with "D ± 16%", and the duty ratio is 3.
In the case of 50% of 0% or more, it increases and decreases periodically by "D±8%". As a result, a small current with a small duty ratio flows through the solenoid coil of the ISC valve 13. For example, the stick-slip phenomenon of the ISO valve 13 is prevented from occurring in the low flow W region of the intake air amount, and the For example, in a high flow area of intake air flow where a large current with a large duty ratio flows through the solenoid coil, IsC valve 1
By eliminating the unnecessary movement of 3, it is possible to stabilize the control of the amount of intake air flowing through the bypass passage 11.

FIG. 7 is a flowchart of a control program r[sc output] routine 100 which is a main part of another embodiment of the present invention.

First, when the processing of this routine 100 is started, in step 101, a function f of the duty ratio calculated by the "rlsc calculation" program 80 and stored in the register is
By (D), the increase/decrease ΔD is calculated by 4, for example, ΔD=100/D.

In the following step 102, the least significant bit B of the soft timer
It is determined whether O is "1-", and if it is "11", the process moves to step 103 in order to increase the duty ratio.

In step 103, the duty ratio is set to "D+ΔD" and the process moves to the next step 104.

In step 104, the ISO valve 13 is
is driven.

On the other hand, if the least significant bit BO of the soft timer is rOJ, the process moves to step 105 to reduce the duty ratio, and the duty ratio is set to [D-8'D1.

Next, the process moves to step 104 described above, and the ISO valve 13 is driven by the pulse signal having the duty ratio determined in step 105.

The above-described processing can provide effects similar to those of the previous embodiment, and since there is no changeover point for increase/decrease, it is possible to control the ISO pulp 13 more precisely. In addition, the ISC valve 13 that uses the function f (D) to obtain 80
By changing it according to the characteristics of the model, it is possible to better match the characteristics of the ISO valve 13 and suppress the stick-slip phenomenon. Note that the processing and configuration other than the rIS "C output" routine 100 are almost the same as in the previous embodiment.

[Effects of the Invention] As described above, according to the idle rotation speed control jJ method of the present invention, a small current with a small duty ratio flows through the solenoid coil of the ISO valve, for example, when the ISO valve is in a low intake air flow region. Prevents stick slip,
Further, there is an effect that unnecessary movement of the ISO valve can be eliminated in, for example, a high flow rate region of the intake air amount, where a large current with a large duty ratio flows through the Tlennort coil of the ISO valve.

[Brief explanation of the drawing]

Fig. 1 is a pulse lock diagram of an ISO valve in a conventional example, Fig. 4 is a 70-diameter diagram representing an RRSC calculation program for calculating the duty ratio of a pulse signal for driving an ISC valve in the same device, and Fig. 5 is a diagram of a pulse lock diagram of an ISO valve in a conventional example. same <rlsc
FIG. 6 is a waveform diagram of a pulse signal for driving the ISO valve, and FIG. 7 is a flowchart showing the control program for the "rlsc output" routine according to another embodiment of the present invention, which corresponds to FIG. 5. Flowcharts 11-1 to 11-1 represent the program. 2...Engine 6...Intake manifold 11
... Bypass passage 12 ... Throttle valve 13 ... ISO valve 14 ... Arithmetic processing circuit 1
7...Fuel injection valve 8...Throttle opening sensor 20...Water temperature sensor 21...Vehicle speed sensor Representative Patent attorney Tsutomu Sadatetsu 1 person

Claims (1)

[Scope of Claims] 1. A linear solenoid idle speed control valve is provided in a bypass passage that supplies air to the engine bypassing the throttle valve to change the flow area of the bypass passage, and the idle speed control valve The duty ratio of the pulse signal supplied to the solenoid coil of the valve is calculated according to the operating state of the engine, and the duty ratio of the pulse signal is increased or decreased periodically to prevent the stick-slip phenomenon of the linear solenoid from occurring. In the method for controlling the idle rotation speed, when the duty ratio is periodically increased or decreased, the increase or decrease is changed according to the operating state of the engine (depending on the calculated magnitude of the duty ratio). An idle rotation speed control method characterized by 3. The idle speed control method according to claim 1, wherein the increase/decrease is set to a value calculated based on a function that takes the duty ratio as a variable.