JPH0367045A - Control device for suction air amount of engine - Google Patents

Abstract

PURPOSE:To suppress a temporary rise of the revolving speed of engine to possible minimum even though a low speed condition is set while the engine is rotating at a low speed by prohibiting increase of the aux. air amount for the decelerative condition in case the engine revolving speed is under a certain specified value when a throttle valve is open. CONSTITUTION:In an electronic type air control unit 25 a throttle valve 13 is turned from full open to full closed at the time tO while a clutch is turned from the engaged condition to the disengaged and till the time to the additional control amount D of a solenoid control valve 16 is nullified when the engine revolving speed NE (Ao). This does not increase the aux, air amount from a main suction bypass 15 due to the solenoid control valve 16, so that rise of the engine revolving speed NE at the time to is suppressed to possible mini mum (solid line), and convergence is made immediately to the idling speed NIOL. In case the engine revolving speed NE is comparatively high as exceeding the mentioned control prohibition judging revolving speed NE (Ao) before the valve 13 is turned from full open to full closed, the additional control amount D1 is set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake air amount control device for an engine mounted on a vehicle, and particularly to a control device for controlling the amount of auxiliary air passing through a bypass intake passage that bypasses a throttle valve. It's about control.

[Conventional technology]

A conventional engine intake air amount control device is, for example,
Some of them are disclosed in Japanese Patent No. 4-4063 and the like. Conventionally, when a throttle valve is changed from an open state to a closed state, the engine speed may drop significantly below the idle speed due to insufficient intake air. In order to deal with this drop in engine speed, conventional devices detect that the throttle valve has changed from an open state to a fully closed or nearly fully closed state, for example, when an idle switch is turned from OFF to ON. , the amount of auxiliary air passing through the bypass intake passage was temporarily increased. This is done by temporarily increasing the opening degree of an electric air control valve provided in the middle of the bypass intake passage that bypasses the throttle valve, compared to the normal basic control amount.

[Problem to be solved by the invention]

Conventional engine intake air amount control devices are as described above, so when the throttle valve is changed from fully open to fully open deceleration state when the engine is running at low speed, when the throttle valve is fully closed, the air downstream of the throttle valve suddenly flows into the engine. The engine speed temporarily increases as the air is fed into the air, but if control is performed to increase the amount of auxiliary air at this time, there is a problem in that the temporary increase in the engine speed increases significantly. especially,
When the clutch was set in drive range when the throttle valve was fully open, and the clutch was switched to neutral when the throttle valve was fully open, the engine suddenly became unloaded, resulting in a significant increase in engine speed. .

The present invention has been made to solve the above-mentioned problems, and provides an engine intake air amount control device that can suppress temporary increases in engine speed as much as possible even when the engine is in a deceleration state at low speeds. The purpose is to obtain.

Means for Solving CtjJB] The engine intake air amount control device of the present invention is a device having a control means for controlling to increase the amount of auxiliary air in response to a deceleration state, wherein the control means has a throttle valve opened. When the engine speed is below a predetermined speed, the amount of auxiliary air is prohibited from increasing in response to deceleration.

[For production]

The control means according to the present invention inhibits control to increase the amount of auxiliary air in response to a deceleration state when the engine speed is low, below a predetermined speed, thereby preventing the engine speed from increasing.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 is a diagram showing the configuration of an engine intake air amount control device according to an embodiment of the present invention. In the figure, a well-known four-stroke spark ignition engine 1 installed in a car etc.
0 is provided with an intake passage 11. The intake passage 11 is provided with, from the upstream side, an air cleaner 12, a throttle valve 13 that is linked to depression of an accelerator pedal, and a surge tank 14, through which the engine 10 mainly takes in combustion air. The main bypass intake passage 15, which connects the intake road 11 upstream and downstream from the throttle valve 13 by bypassing the throttle valve 13, has an electromagnetic air control valve as an example of an electric air control valve that controls the flow passage cross-sectional area. Control valve (
An electromagnetic air control valve (16) is provided. The opening degree of this electromagnetic control valve 16 is adjusted according to the duty ratio of the applied drive signal, and the larger the duty ratio, the larger the opening degree becomes. Similar to the main bypass intake passage 15, a fast idle bypass passage 17 and an auxiliary bypass intake passage 18 which bypass the throttle valve 13 are provided. A well-known thermowax fast idle valve 19 is provided in the fast idle bypass passage 17, and its flow passage cross-sectional area is automatically adjusted according to the coolant temperature of the engine 10, and its opening degree is inversely proportional to the coolant temperature. or,
On the 1st day of the auxiliary bypass intake passage, its flow passage cross-sectional area is mf
An idle adjusting screw 20 is provided. The idle adjusting screw 20 is manually set to y4 by an operator when adjusting the idle rotation speed.

A crank angle sensor 22 is attached to a distributor 21 included in a part of the ignition system for the engine 10, and this sensor 22 generates an angle pulse every time the crankshaft of the engine 10 rotates by a predetermined angle.

An idle switch 23 that detects that the throttle valve 13 is in an idling position, that is, in a fully open state, changes from OFF to ON when it detects that the throttle valve 13 is fully closed.

Further, the throttle opening sensor 24 detects the opening e of the throttle valve 13, and outputs an analog detection signal having a magnitude corresponding to the opening e.

The electronic air control unit 25, whose configuration is shown in FIG. 2, includes a crank angle sensor 22, an idle switch 2,
3. Manually input each output signal of the throttle opening sensor 24,
The input signal is processed according to a predetermined process, and the opening degree of the electromagnetic control valve 16 is controlled based on the processing result.

As is well known, the intake passage 1 downstream from the throttle valve 13
The pressure in the surge tank 14 is detected by the pressure sensor 26, which detects the pressure in the surge tank 14 as the pressure in the intake pipe. An amount of fuel commensurate with the detected intake pipe internal pressure and the detected engine speed based on the angle pulse from the crank angle sensor 22 is injected into the engine 10 from the fuel injection valve 27 provided for each cylinder of the engine 10. is supplied by injection.

The fuel injection valve 27 is connected to a fuel system (not shown), and is driven to open by a fuel control system. Therefore, the rotational speed of the engine 10 can be controlled by controlling the intake air amount of the throttle valve 13 or 1 using the magnetic control valve 16 or the like.

FIG. 2 shows the configuration of the electronic air control unit 25 shown in FIG. , ) 30, an A/D converter 31 that converts an analog input signal into a digital signal and inputs it to the microcomputer 30; a drive circuit 32 that amplifies the duty drive signal output from the microcomputer 30 and supplies it to the electromagnetic control valve 16; It consists of

The microcomputer 30 is a CPU that performs various calculations and judgments.
30A, a ROM 30B in which the flowcharts of FIGS. 3 to 6 are stored as programs, and a RAM 30C as a work memory.

The angle pulse from the crank angle sensor 22 is transmitted to the microcomputer 3.
0 manually, and the period is used to calculate the number of revolutions. The analog detection signal from the throttle opening sensor 24 is converted by the A/D converter 31 into a digital signal of a throttle opening value θ representing the throttle opening e, and then sent to the microcomputer 3.
Read into 0. ON/OFF of idle switch 23
The F signal is manually input into the microcomputer 30 as it is.

FIG. 3 shows the main routine for calculating the control amount of the electromagnetic control valve 16 according to this embodiment. First, in step 101,
After initialization, in step 102, rotation speed data N, (ccN,) representing the engine rotation speed Nt is calculated based on the period of the angle pulse from the crank angle sensor 22. The period of the angle pulse is calculated by an interrupt routine (not shown), which is interrupted every time the angle pulse is generated.

In step 103, the process shown in FIG. 4 is executed to perform basic control of the electromagnetic control valve 16 according to the engine speed N.
Calculate 1E. In step 104, the throttle opening value θ((X:8)) obtained by A/D converting the output signal of the throttle opening sensor 24 is read.

In step 105, the process shown in FIG. 5 is executed, and the electromagnetic control valve 16 is
In addition to the basic control 31B, the control amount Z of the electromagnetic control valve 16 is calculated based on the duty ratio. After the processing in step 105, the process returns to step 102 and repeats the above operation.

Next, the arithmetic processing of the basic control 11 of the electromagnetic control valve 16 will be described with reference to FIG. In step 1031, it is determined whether the rotation speed data N is less than or equal to a first predetermined value A.

If it is below, it is determined in step 1032 whether or not it is every fixed time, and if it is not every fixed time, the process of FIG. E is updated by adding the previous basic control IH to the first control value (however, E is the duty ratio of 100%).
is the upper limit).

On the other hand, if it is determined in step 1031 that N,>A, it is determined in step 1034 whether or not the rotation speed data N is equal to or greater than the second predetermined value +ia 8;
The process shown in the figure is completed, and if the above is the above, it is determined in step 1035 whether or not it is every fixed period of time. If it is not every certain time, the process in FIG. 4 is finished, and if it is every certain time, step 10
At 36, the previous basic system a certain amount of time ago? E is updated by subtracting 8 from the second control value (however, the lower limit of E is the duty ratio of 0%).

The above K + and K z are stored and set in advance,
K1 acts in the direction of increasing the opening, and K acts in the direction of decreasing the opening. After the processing in step 1033 or step 1036, the processing in FIG. 4 ends. In addition, the idle speed NID
If the value corresponding to L is IDL, then the relationship A<IDL<B holds true, and the difference between B and A corresponds to a rotational speed difference of several tens of rotations in units of rpw, for example.

Next, the calculation process of the control amount of the m1ft@m valve 16 will be explained with reference to FIG. In step 1050, it is determined whether or not the previously read throttle opening value θ is greater than or equal to the control amount generation determination opening value 01 stored in advance, that is, the throttle valve 13
It is determined whether or not the throttle opening degree e of
The initial value Dl of the additional control rIJI for temporarily increasing the amount of auxiliary air during deceleration is stored in the RAM 30 in advance.
If it is not 0 or more, or after the processing in step 1051, the process proceeds to step 1052, and the idle switch 23 is changed from OFF to OFF.
It is determined whether or not after the change to N. If it has changed, the process advances to step l053 and the idle switch 23 is turned OFF.
It is determined whether a predetermined period of time has elapsed since the switch was turned on. If the predetermined period of time has elapsed, the process proceeds to step 1054, where it is determined whether or not it is every certain period of time, and if it is every certain period of time, in step 1055, 1 is subtracted from the additional control amount M stored in the first storage device. To update M by subtracting, however, M
After that, proceed to the next step 1056.
If it is determined in step 1052 that it is not after a change, if it is determined in step 1053 that it has not been after a certain period of time, or if it is determined in step 1o54 that it is not after a certain period of time, proceed to step 1056. In step 1056, the rotation speed data N is stored in the ROM 30B.
Determine whether or not the control prohibition judgment rotational speed stored in advance is greater than or equal to 0, that is, whether the engine rotational speed N is greater than or equal to the control prohibition judgment rotational speed Nt (As) corresponding to A0. If it is 0 or more, step 1057 Then, the additional control amount M, which is the content of the first storage location, is stored as an additional control amount in a memory (for example, RAM 30C or a register) for storing the additional control amount.
is also stored, and if it is not more than that, in step 1058, is it an additional requirement? Set fl ID to O. Here, the additional control amount indicates the duty ratio.

In the next step 1059, basic control IE and additional system? B
ND is added to calculate the control amount z of the magnetic It in valve 16 using the duty ratio, and the process in FIG. 5 is completed.

When an interrupt signal is generated by a timer at regular intervals during the execution of the main routine shown in FIG. 3, the execution of the main routine is immediately interrupted and the interrupt routine shown in FIG. 6 is executed. In step 201, a drive signal of the duty ratio of the control amount Z is sent to the electromagnetic control valve 16 via the drive circuit 32 to drive it, and the process returns to the main routine.

Figure 7 shows engine speed Nt and additional control scale.

Throttle opening value θ, clutch state time t (horizontal axis)
The solid line shows the present example, and the broken line shows the conventional example. At time 0 L6, the throttle valve changes from fully open to fully open.
The clutch changes from the connecting state to the disengaged state, t, the part name is engine rotation speed N, control prohibition judgment rotation speed N, (A@)
At low RPMs below. In the conventional device, in order to increase the amount of auxiliary air by setting an additional amount '4n from time Lo, the engine speed N temporarily increases significantly after time t0, and then decreases to the idle speed. Converges to NIIIL. However, in this embodiment, the engine rotation speed N.

Since is less than N, (A,), the additional control scale is 0, and since the auxiliary air amount is not increased as in the conventional example, the increase in engine speed N7 from time to is suppressed as low as possible, and the idle speed is immediately increased. It converges to N1°. If the engine rotational speed Nt is relatively high, equal to or higher than the control prohibition determination rotational speed Nt(,l), before the throttle valve changes from fully open to fully open, the additional control amount is set in this embodiment as well. However, is there an additional restriction during deceleration? The rotational speed does not increase in response to the increase in the amount of auxiliary air due to BID, as in the conventional case, and the basic control amount E is 0 during deceleration before idling.

〔Effect of the invention〕

As described above, according to the present invention, when the engine speed is below a predetermined speed when the throttle valve is open, control to increase the amount of auxiliary air in response to a deceleration state is prohibited. This has the effect of preventing an increase in engine speed.

[Brief explanation of drawings]

Fig. 1 shows the constituent countries of the device showing one embodiment of the present invention, Fig. 2 shows the constituent countries of the electronic air @ control unit in Fig. 1, and Fig. 3 shows the flowchart showing the main operation of the above embodiment. 4 and 5 are flowcharts showing the operation of each one process in FIG. 3, FIG. 6 is a flowchart showing the interrupt operation of the above embodiment, and FIG.
The figure is a waveform diagram showing the timing of the operation according to the above embodiment and the timing of the operation according to the conventional device. In the figure, 10...engine, 11...intake passage, 13
...Throttle valve, 15...Main bypass intake passage,
16... Solenoid control valve, 22... Crank angle sensor,
25...Electronic air control unit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] a bypass intake passage that supplies auxiliary air to the engine by bypassing the throttle valve; an electric air control valve that controls the amount of the auxiliary air that passes through the bypass intake passage; and control means for controlling the amount of auxiliary air to be increased in response to a deceleration state in which the engine is decelerating. If the number of revolutions is less than the specified number of revolutions,
An intake air amount control device for an engine, characterized in that control to increase the amount of auxiliary air is prohibited in response to the deceleration state.