JPH0367040A - Control device for suction air amount of engine - Google Patents

Abstract

PURPOSE:To prevent attachment of dust, etc., to an air bypass to the possible minimum degree by controlling to the minimum the degree of opening of a motor-driven air control valve furnished on a suction bypass in case the engine operating condition is in the operating range specified in advance. CONSTITUTION:An air cleaner 12, a throttle valve 13 interlocked with the stamp ing of accel, pedal, and a surge tank 14 are furnished on a suction passage 11 in the sequence as named from the upstream side, and a main suction bypass 15 to detour this throttle valve 13 is furnished with a solenoid control valve 16 to control the section area of the flow path of this suction bypass, and the degree of opening of this control valve 16 is adjusted according to the duty ratio of the impressed drive signals in such a tendency as increasing with the duty ratio. An electronic air control unit 27 calculates the duty ratio of the control amount D of the valve 16 according to the size of the degree-of-opening value of throttle, condition of an electric load switch 26, and the size of the number-of-revolutions data. When the degree of opening of the valve 13 is over the set value, i.e., when the operating condition of engine 10 lies within the control stop operating range of the valve 16, 'zero' shall be set as the control amount D of the valve 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake air amount control device for an engine installed in an automobile or the like.

[Conventional technology]

A conventional engine intake air amount control device includes a bypass intake passage that supplies auxiliary air to the engine by bypassing a throttle valve, and an electric air control valve that controls the cross-sectional area of the bypass intake passage. When the engine is in an idling state, a target number of revolutions set according to the idling state of the engine is compared with an actual number of revolutions, and the opening degree of the electric air control valve is controlled so as to maintain the number of revolutions at the target number of revolutions. Further, the electric air control valve is controlled to open by a predetermined amount so as to provide a constant amount of air, which is set according to the application of the electrical load or the operating state of the engine.

[Problem to be solved by the invention]

As described above, the conventional engine intake air amount control device always drives and controls the electric air control valve regardless of the operating state of the engine, so the number of operations thereof increases. For this reason, the electrically operated air control valve used to control the amount of intake air is required to be durable enough to withstand the number of times it is operated, making it expensive. If the price of the electric air control valve becomes expensive, the price of the engine intake air amount control device will increase, causing the problem that the price of the device itself will become expensive. Further, since auxiliary air always flows through the bypass intake passage including the electric air control valve, dust, oil, etc. contained in the auxiliary air adhere to the bypass intake passage and obstruct the flow path of the bypass intake passage. This caused problems such as inability to control the intake air, resulting in engine rotation fluctuations and an abnormal drop in engine speed, and in the worst case scenario, the engine stalled.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to disconnect the flow path of a bypass intake passage provided with an electric air control valve when the operating state of the engine is in a predetermined operating range. To provide an engine intake air amount control device which can prevent dust etc. from adhering to a bypass intake air passage as much as possible by minimizing the area and can use an inexpensive air control valve.

[Means for Solving the Problems] The intake air amount control device for an engine of the present invention includes a bypass intake air passage, an electric air control valve provided in the passage, and an air control valve that can be opened depending on the operating state. In the apparatus, the control means is configured to minimize the opening degree of the air control valve when the operating condition of the engine is within a predetermined range.

[For production]

The intake air amount control device for an engine according to the present invention controls the electrically operated air control valve so as to minimize the flow passage cross-sectional area of the bypass intake passage by the control means when the operating state of the engine is in a predetermined operating range. However, since the effect on the total intake air amount of the engine is small, the effect on the operating state of the engine is small.

〔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 mounted on 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 that connects the upstream and downstream of the intake passage 11 from the throttle valve 13 by bypassing the throttle valve 13 is an example of an electric air control valve that controls the cross-sectional area of the passage. Solenoid control valve as (
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 opening degree increases as the duty ratio increases. Similar to the main bypass intake passage 15, a fast idle bypass passage 17 and an auxiliary bypass intake 'a passage 18 are provided which bypass the throttle valve 13. The fast idle bypass passage 17 is provided with a well-known thermowax type fast idle valve 19, which automatically adjusts its flow passage cross-sectional area according to the coolant temperature of the engine 10, and its opening degree is inversely proportional to the coolant temperature.

Further, the auxiliary bypass intake passage 18 is provided with an idle adjusting screw 20 whose flow passage cross-sectional area is f[. This idle adjusting screw 20 is manually adjusted 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, which 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 open.

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.

For example, an electric load 25 such as an air conditioner or a motor is operated by being supplied with power when an electric load switch 26 is turned on. This electric power is supplied from a power generation device (not shown) driven by the engine 10. When electric power is being supplied to the electrical load 25, the corresponding load is applied to the engine IO, increasing the load on the engine IO.

The electronic air control unit 2F, whose detailed configuration is shown in FIG. 2, receives signals from the crank angle sensor 22, throttle opening sensor 24, and electric load switch 26, and The process is performed according to a predetermined process, and the opening degree of the electromagnetic control valve 16 is controlled based on the process 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 28 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 a fuel injection valve 29 provided for each cylinder of the engine 10. is supplied by injection.

The fuel injection valve 29 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 amount of intake air using the throttle valve 13, the electromagnetic control valve 16, or the like.

FIG. 2 shows the configuration of the electronic air control unit 27 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 5 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.
It is input as 0 and used to calculate the number of revolutions from that period. The analog detection signal from the throttle opening sensor 24 is converted by the A/D converter 31 into a digital signal of the throttle opening value θ representing the throttle opening e, and then sent to the microcomputer 3.
Read into 0. 0N-OF of electric load switch 26
The F signal is input into the microcomputer 30 as it is. In addition,
The ON signal of the electric load switch 26 is °"H rubel, O
The FF signal is at L'' level.

FIG. 3 shows a main routine for calculating the control amount of the electromagnetic control valve 16 according to this embodiment. First, in step 101,
Initialization is performed, and in step 102, rotation speed data N-("NE) representing the engine rotation speed N is calculated based on the cycle of the angle pulse from the crank angle sensor 22. The cycle of the angle pulse is An interrupt is generated each time , and the calculation is performed by an interrupt routine (not shown).In step 103, the throttle opening value θ(oce) obtained by A/D converting the output signal of the throttle opening sensor 24 is read. In step 104, the process shown in FIG. 4 is executed to determine the magnitude of the throttle opening value θ,
The control ilD of the electromagnetic control valve 16 is calculated by the duty ratio according to the state of the electric load switch 26 and the magnitude of the rotation speed data N. After processing step 104, step 102
Go back and repeat the above operation.

Next, with reference to FIG. 4, the calculation process of the control amount of the electromagnetic control valve 16 will be described. First, in step 1001, it is determined whether the electric load switch 26 is ON or not, and if it is ON, in step 1002, the first control amount or, which has been previously stored and set in the ROM 30B, is stored in the first storage location of the RAM 30C. The first control '4B is stored as IN, and if it is not ON, the process goes to step 1003. The control amount N is set to O. Next, in step 1004, the rotation speed data N, .
It is determined whether or not is less than or equal to a first predetermined value A. If it is below, it is determined in step 1005 whether or not it is at a certain time interval, and if it is not at a certain time interval, the process proceeds to step 1010, and if it is at a certain time interval, in step 1006, an increase control is performed on the idle control amount I from a certain time ago. After updating ■ by adding to the amount, the process proceeds to step 101O.

On the other hand, if it is determined in step 1004 that N,>A, then in step 1007 the rotation speed data N is determined.

It is determined whether or not is equal to or greater than a second predetermined value B. If it is not greater than the second predetermined value B, the process proceeds to step 1010, and if it is greater than or equal to the second predetermined value B, the process proceeds to step 101.
In step 8, it is determined whether or not it is done at regular intervals.

If it is not every certain time, the process advances to step 1010, and if it is every certain time, the process goes to step 1009, where the previous idle system from a certain time ago? After subtracting 2 from Bit+ to the down control amount and updating ■, the process proceeds to step 101O.

The above, , and are stored and set in advance, and K1 acts in the direction of increasing the opening degree, and K2 acts in the direction of decreasing the opening degree. B
The difference between and A corresponds to a difference of several tens of revolutions in rpm, and
If the value equivalent to the idle rotation speed is IDL, then A<IDL<
It is B.

In step 1010, it is determined whether a certain period of time has elapsed after the engine 10 was started. This is based on the rotation speed data N0, and it is determined whether a certain period of time has elapsed from when the engine rotation speed N becomes equal to or higher than a predetermined rotation speed at the start of engine startup. If a certain period of time has passed after startup, step 10
In step 101, the second control amount D2, which has been stored and set in advance in the ROM 30B, is stored in the second storage location of the RAM 30C as the second control amount P. 2 control 3111P is set to O.

Next, in step 1013, the first control amount N is determined.

Idle control amount 1. The sum of all the second control amounts P is calculated and stored as the total control amount M in the third storage location of the RAM 30C. In step 1014, rotation speed data N,
It is determined whether or not is equal to or greater than a third predetermined value N, 1 corresponding to the engine rotation speed NE+. N, ≧N□, engine speed NE
If is greater than or equal to N0, the process proceeds to step 1015, where it is determined whether or not the throttle angle value θ is greater than or equal to the throttle opening degree θ, a corresponding throttle angle setting value θ9. If θ≧θ and the opening degree of the throttle valve 13 is 03 or more, the operating state of the engine 10 is within the controlled stop operation range of the electromagnetic control valve 16. As shown in Fig. 6, this controlled stop operation region is defined by the following when the horizontal axis is the engine rotation speed N2 and the vertical axis is the throttle opening e.
The mesh region where the conditions of Nt≧N□ and e≧e1 are satisfied is a region where even if the amount of auxiliary air passing through the main bypass intake passage 15 is cut, the effect on the operating state of the engine 10 is small. If it is determined that the operating state of the engine 10 is within the controlled stop operating region, the process proceeds to step 1016, and the control amount storage memory (
O is set in the RAM 30C (inside the RAM 30C or in the register) as the control amount for the electromagnetic control valve 16.

At step 1014, if N, <N, the engine rotational speed N
t is less than the rotational speed N0 or θ<θ1 in step 1015
When it is determined that the opening degree e of the throttle valve 13 is less than the opening degree 81, the operating state of the engine 10 is outside the controlled stop operation region outside the mesh portion shown in FIG. Outside this controlled stop operation region, the amount of auxiliary air passing through the main bypass intake passage 15 is the main intake air amount of the engine 10, so cutting the amount of auxiliary air will greatly affect the operating state of the engine 10. Therefore, in order to control the electromagnetic control valve 16, the process proceeds to step 1017, and the total control amount M is transferred to the control amount storage memory as the control ID.

If step 1016 or 1017 is processed,
The process shown in FIG. 4 ends. Note that N and IP indicate the duty ratio, and M and D indicate the duty ratio of the drive signal applied to the electromagnetic control valve 16.

When the timer generates an interrupt signal 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. 5 is executed. In step 201, a drive signal with a duty ratio of the control quantity is sent to the electromagnetic control valve 16 via the drive circuit 32, and the control valve 16 is driven, and the process returns to the main routine. here,
When the operating state of the engine 10 is within the control stop operating region shown in FIG.
6 is stopped, and the electromagnetic control valve 16 is brought into a fully closed state by the bias of a built-in spring and maintained. Therefore, the main bypass intake passage 15 is closed and the amount of auxiliary air passing therethrough becomes zero.

In other cases, the opening degree of the electromagnetic control valve 16 is controlled to become larger as the duty ratio of the control ID becomes larger.

[Effects of the Invention] As described above, according to the present invention, when the operating state of the engine is in a predetermined operating range, the flow passage cross-sectional area of the bypass intake passage is configured to be minimized. Since it is possible to prevent dust, oil, etc. from adhering to the engine as much as possible, it is possible to prevent abnormal decreases in rotational speed and stalling of the engine, and because the number of operations is reduced, it is possible to use an inexpensive electric air control valve. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the electronic air control unit shown in FIG. 1, and FIGS. Each flowchart showing the operation of the embodiment and FIG. 6 are explanatory diagrams showing the control stop operation region. In the figure, 10...engine, 11...intake passage, 13
...Throttle valve, 15...Main bypass intake passage,
16... Solenoid control valve, 22... Crank angle sensor,
24... Throttle opening sensor, 28... Pressure sensor. Note that the same reference numerals in the figures indicate the same or equivalent parts. ;:, :2 Figure 3 Figure 6 Figure 5 Procedural amendment (voluntary) 1. Indication of the case Representative of the person making the amendment to Patent Application No. 1-203132 Moriya Shiki "Detailed Description of the Invention" column and Drawing 6, contents of amendment (1) "Predetermined angle rotation" on page 6, line 8 of the specification was changed to "
``rotation by a predetermined angle''. (2) On page 11, line 18, "if it has passed" is amended to "if it has not passed". (3) From the first line of page 12 to the second line of the same page, amend "if it has not passed" to "if it has passed." (4) Delete "rN, ≥N1" on page 12, line 9. (5) Delete "Fθ≧θ," on page 12, line 13 of the same page. (6) Delete "rN, <N□" on page 13, line 7. (7) Delete “θ〈θ1” on page 13, line 9. (8) Correct Figure 4 as shown in the attached sheet. 7. List of attached documents (1) At least one corrected drawing of Figure 4
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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 a cross-sectional area of the bypass intake passage; and an electric air control valve that controls the air according to the operating state of the engine. In the engine intake air amount control device comprising a control means for controlling the opening degree of a valve, the control means controls the bypass intake air amount when the operating state of the engine is within a predetermined operating range. An intake air amount control device for an engine, characterized in that control is performed to minimize the cross-sectional area of a passage.