JPS61178527A - Controller of intake air quantity for internal-combustion engine - Google Patents

Abstract

PURPOSE:To simplify a device while improve control accuracy by controlling idling rotation and prevention of the intake negative pressure from overly rising at the time of deceleration, by using an electromagnetic closing valve which is installed in a passage which bypasses an intake air throttle valve such as an electronically controlled ISC valve and the like. CONSTITUTION:An ISC valve 7 is operated at the time of idling operation of an engine. In driving areas other than that, basic control is made by the ISC valve 7 and, at the time of deceleration of an internal-combustion engine 1, a duty of the ISC valve 7 for previously obtaining a certain engine intake negative pressure, is detected from a memory means in accordance with the engine speed, and either this value or the control duty of the ISC valve 7 whichever is the larger, is selected to make duty control of the ISC valve 7. Therefore, the opening duty of the ISC valve 7 increases in accordance with the engine speed, to prevent increase in intake negative pressure while preventing oil from being exhausted. As a result, the device can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake air amount control device for an internal combustion engine, and more particularly to an intake air amount control device during idling and deceleration.

<Prior Art> As shown in FIG. 2, when the internal combustion engine 1 is in a deceleration state with the intake throttle valve 2 fully closed, when the engine rotation speed is high, the intake air in the intake passage 3 downstream of the intake throttle valve 2 is Negative pressure increases abnormally, and oil rises from the valve guide or piston outer circumference of the engine 1. Therefore, conventionally, in order to prevent such inconvenience, a VC valve (vacuum control valve) 4 that is opened and closed by differential pressure is interposed in a bypass passage 6 that connects the air flow meter 5 and the intake passage 3 downstream of the intake throttle valve 2. In the deceleration region where the suction negative pressure increases, the VC pulp 4 is opened to introduce intake air downstream of the intake throttle valve 2, thereby preventing the suction negative pressure from rising excessively.

On the other hand, as seen in Japanese Patent Application Laid-Open No. 59-211739, an idle rotation speed control I (ISC) valve 7 of an internal combustion engine is provided in an auxiliary air passage 8 that bypasses the intake throttle valve 2 to stably control the idle rotation speed. What it does is known. For example, as shown in Fig. 3, this is a rotary set, and pulse signals are sent to a valve opening coil and a valve closing coil (not shown) in an inverted state, and the duty of the pulse signal is The opening degree is adjusted accordingly. Note that 9 is an SP1 type fuel injection valve, and the diagram does not necessarily correspond to FIG. 2. 10 in FIG. 2 is an air flow meter.

These VC pulp 4 and ISC valve 7 are respectively disposed exclusively for use during engine deceleration and during idling, and to this extent, both have value in coexistence.

By the way, the ISO valve performs feedback control to bring the actual detected rotational speed closer to the target engine rotational speed only when the engine is idling, but when the engine enters an operating state other than idling, it immediately performs feedback control when transitioning to the next idling. To stabilize the opening, open loop control is performed to adjust the opening according to the cooling water temperature, etc. Therefore, when the engine decelerates, the open-loop control of ISO pulp
This overlaps with the operation of the C valve.

<Problems to be Solved by the Invention> As described above, the present invention uses the same VC valve and ISO valve, which bypass the same intake throttle valve to control the intake flow, and improves the function of the ISO valve, so that only the ISO valve can be used. It is an object of the present invention to simplify the device by having both the valves perform their functions.

(Means for Solving the Problems) To achieve this, in the present invention, as shown in FIG. a storage means that stores in advance a duty of the electromagnetic on-off valve for obtaining a predetermined engine suction negative pressure according to the engine rotation speed; and a duty output of the control means according to the engine rotation speed and a duty retrieved from the storage means. A second control means is provided which compares the output and selects a larger value among the outputs and outputs it to the electromagnetic on-off valve instead of the output of the first control means.

As a result, during engine idling operation, the IS
The basic control mode is to operate the O valve (electromagnetic on-off valve), while in other operating ranges, the rsc valve is controlled according to the engine operating status, etc., as in the past, and when the engine is decelerating, a predetermined engine suction Search the storage means for the ISO pulp duty for obtaining pressure according to the engine rotation speed, select the larger of the search value and the conventional control duty of the ISO valve, and use the selected value to
Duty control the valve. As a result, when the engine is decelerated, the opening duty of the ISO pulp increases in accordance with the engine rotational speed, thereby preventing an increase in suction negative pressure and oil leakage, and making it possible to omit the VC valve.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the basic diagrammatic configuration of the present invention in which the auxiliary air passage 8 and the VC pulp 4 are omitted from the conventional example shown in FIG. 2, and the control means for the I'S C valve 7 is improved. .

Next, the hardware configuration of the present invention will be explained based on FIG. 4. In FIG.
3 is an OMO3-RAM, and 14 is an address decoder. Note that a bank-up power supply circuit is used for the RAM 13 in order to retain the stored contents even after the key switch is turned off.

Analog input signals to the CPU II for controlling the ISC valve 7 include a water temperature signal from the water temperature sensor 15, an intake throttle valve 2 opening signal from the throttle sensor 16, and a battery voltage signal from the battery 17. It is designed to be input via an analog input interface 18 and an A/D converter 19. 20 is an A/D conversion timing controller.

As digital input signals, there are ON/OFF signals from the idle switch (switch that detects when the intake throttle valve 2 is fully closed) 21, the neutral switch 22 that detects the neutral position of the transmission, and the air conditioner switch 23, and these are connected to the digital input interface. 24
It is now input via the .

In addition, a reference signal every 180 degrees and a position signal every 1 degree, for example, from the crank angle sensor 25 are inputted via a one-shot multi-circuit 26. Further, a vehicle speed signal from a vehicle speed sensor 27 is inputted via a waveform shaping circuit 28.

The output signal from the CPU II (pulse signal to the ISO valve 7) is sent to the valve-opening coil 7a and valve-closing coil 7b of the SC valve 7 via the phase inversion driver 29 in a mutually inverted state. It is now possible to

Here, the CP Ull performs input/output operations and calculations according to a program (stored in the ROM 12) based on the flowchart shown in FIG. It is designed to perform processing, etc.

Next, the flowchart shown in FIG. 5 will be explained.

Control value I of control pulse duty ratio of ISO valve 7
SCe is given by the following equation.

I SCe” ISCtw+ I SC+ + I 5
CsteHere, l5Cz- is the basic control value according to the engine cooling water temperature Tw, ISO, is the feedback correction value when the engine is in the idle state, and ■SC□ゎ is the basic control value according to the engine cooling water temperature Tw. The control value is, for example, the corrected control value rsc, c when the air conditioner is activated, or the corrected control value l5CTR when the engine is accelerated or decelerated.

First, the water temperature Tw detected by the water temperature sensor 15 at Sl
The basic control value l5et- is set from . This setting may be performed by storing a map of the basic control value l5Ct using the water temperature Tw as a parameter in advance in the ROM 12, and searching from the map, or by calculation.

In S2, various correction amounts I SO, , c such as air conditioner correction rsc, C and acceleration/deceleration correction l5CTR are set as necessary.

In S3, a target rotational speed Ns is set from the water temperature Tw.

This setting may also be performed by storing a map of the target rotational speed Ns using the water temperature Tw as a parameter in advance in the ROM 12, and searching from the map, or by calculation.

In S4, it is determined whether the ISO condition (area where ISO is performed) is met. Specifically, when the idle switch 21 that detects the fully closed position of the intake throttle valve 2 is ON (the intake throttle valve 2 is in the fully closed position) and the neutral switch 22 is ON (the gear position of the transmission is neutral), or When the idle switch 21 is ON and the vehicle speed detected by the vehicle speed sensor 27 is less than or equal to a predetermined value, it is assumed that the ISO condition is met, and the process proceeds to the next step 85.

In S5, the target rotation speed Ng and the actual rotation speed N detected by the crank angle sensor 25 are compared. Then, a feedback correction value ISO is set based on the comparison result. That is, if Ns>N, the feedback correction value rsc is calculated to increase the previous value by a predetermined amount by proportional-integral control in S9, and if Ns<N, the feedback correction value rsc is increased by the proportional-integral control in S7. ISO, is decreased by a predetermined amount from the previous value by calculation. If N5=N (including the fuwazai), the feedback correction value ISO is kept at the previous value.

Then, in S8, the control value ISCe is calculated according to the following equation.

I SCe” I SCtw+ I SC+ + IS
C*tc The pulse duty under the ISC condition is determined by this l5Ce value, and is applied to the valve opening coil 7a and valve closing coil 7b of the ISC valve 7 via the phase inversion driver 29 to maintain a stable idle rotation speed. controlled. Such control is similar to feedback control of a conventional ISO valve.

On the other hand, when the ISO condition is not satisfied in S4, ISC+=0 is set in Sll, and a control value l5Ce is calculated according to the following formula %, and a pulse signal with a duty ratio based on this is output to the ISO pulp 7. This output pulse has an open loop duty and is not subjected to feedback control. This is to prevent a gap in duty output from occurring in the boundary area between feedback control during engine idling and other areas, which would impair drivability. Therefore, open-loop control as described above is performed even outside the idle operating range, and when shifting to feedback control, the deviation in correlation with the target rotation speed is reduced.
To shorten the time it takes to settle down to the original target rotation speed through feedback control. Otherwise, the integral constant (Is) of integral control when setting the feedback correction value I SCe
must be increased, which may cause hunting, over (under) shoot, etc., resulting in unstable idle rotation or engine stall due to drop in rotation.

In S12, it is determined that the engine is in a deceleration state.

As the deceleration judgment means here, the throttle sensor 1
6 is fully closed and neutral switch 22 is OFF.
F () Transmission connection) or vehicle speed sensor 2
7 is a predetermined value or more, it is determined that the engine is decelerating.

If the engine is not in a deceleration state, the pulse duty 15Ce determined by Sll is output and the SC valve 7 is controlled in an open loop; however, if deceleration is detected, the process advances to S13.

In S13, the duty VC of the ISO valve 7 is determined according to the engine rotational speed N during deceleration and the amount of air flowing through the auxiliary air passage 8 so that the intake negative pressure downstream of the intake throttle valve 2 does not rise excessively.
e is previously stored in the ROM 12, which is a storage means, and the value of this VCe is searched according to the detected engine rotational speed at that time.

And if l5Ce≧VCe in S14,
Since there is no risk that the suction negative pressure downstream of the intake throttle valve 2 will rise excessively even with the pulse duty ISCe determined by Sll, l5Ce is selected in S15 and output to the ISO pulp 7 via the phase inversion driver 29.

However, if ISCe<VCe, the conventional IS
Since the suction negative pressure rises excessively at the output value ISCe to the O pulp, the opening degree of the ISC pulp 7 should be greatly increased (ISO
Switch the output control value to valve 7 to VCe. This increases the amount of intake air that bypasses the intake throttle valve 2, prevents the intake negative pressure from rising excessively, and avoids problems such as oil leakage.

In this embodiment, an auxiliary air passage 8 in which ISO pulp 7 is interposed is used as a passage that bypasses the intake throttle valve, and the electromagnetic on-off valve interposed in the bypass passage is a two-phase coil type ISO valve 7. has been selected. However, a single-phase coil type electromagnetic on-off valve may also be used. The engine operating state detection means according to the present invention may include at least rotation speed detection means for detecting the cooling water temperature and the actual rotation speed for calculating the target rotation speed, and may also include various sensors shown in the embodiments. Of course, it is possible.

Furthermore, in the case of this embodiment, the first control means referred to in the present invention refers to the first control means 81 to S12 shown in FIG.
This means also includes feedback control means during engine idling shown at 81 to S8 and open loop control means shown at Sll.

Note that the open loop control means described above can be omitted by appropriately setting the value of VCe shown in S13.

<Effects of the Invention> As described above, according to the present invention, the VC pulp conventionally used as a countermeasure against deceleration is abolished, and instead it is inserted into the passage that bypasses the intake throttle valve such as the electronically controlled ISO valve. Since the idling rotation control and suction negative pressure over-rise prevention control during deceleration are performed using the electromagnetic on-off valve, these functions can be performed in a single device, simplifying the device.For example, As you can see, the addition of a deceleration countermeasure function improves control accuracy.

[Brief explanation of drawings]

Figure 1 is a claim correspondence diagram showing the basic configuration of the present invention, Figure 2 is a claim correspondence diagram showing the basic configuration of the present invention.
The figure is a schematic configuration diagram of a conventional device including an ISO valve and a VC valve, FIG. 3 is a vertical cross-sectional view of the ISO valve, FIG. 4 is a hardware configuration diagram showing an embodiment of the present invention, and FIG. 5 is the same as above. This is a flowchart. 1... Internal combustion engine 2... Intake throttle valve 3...
Intake passage 7...ISC valve 8...Auxiliary air passage (bypass passage) 11...CPU 12.
・・P-ROM (memory means) 15 ・・Water temperature sensor
22...Neutral switch 25...Crank angle sensor 27...Vehicle speed sensor Patent applicant Japan Electronics Co., Ltd. Agent Patent attorney Fujio Sasashima Figure 2 Figure 3 Figure 1 l

Claims (2)

[Claims] (1) means for detecting the operating state of the engine, including at least the rotational speed and cooling water temperature; a passage that bypasses the intake throttle valve installed in the intake passage; an electromagnetic on-off valve installed in the bypass passage; An internal combustion engine comprising: a first control means for controlling the duty of an opening/closing pulse of an electromagnetic on-off valve in accordance with a detected engine operating state; and an engine deceleration determining means; storage means that stores in advance the duty of the electromagnetic on-off valve for obtaining a predetermined engine suction negative pressure according to the engine speed; and a duty output of the first control means according to the engine rotational speed and a duty output retrieved from the storage means. and a second control means that selects a larger value among the values and outputs it to the electromagnetic on-off valve instead of the output of the first control means. Control device. (2) The first control means includes an idling operation detection means for the engine, a target rotation speed setting means for the engine, and a control means for controlling the electromagnetic on-off valve in order to reduce the amount of deviation between the target rotation speed and the detected rotation speed during idling. The second control means includes means for feedback controlling the duty, and means for open-loop control of the duty of the electromagnetic on-off valve so as to achieve the target duty in an operating range other than idling, and the second control means is configured to control the duty of the electromagnetic on-off valve when the open control means is actuated. An intake air amount control device for an internal combustion engine according to claim 1, wherein the intake air amount control device operates.