JPS60249635A - Fuel feed controller for internal-combustion engine equipped with sub combustion chamber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

(Technical Field) The present invention relates to a fuel supply control device for an internal combustion engine having a sub-combustion chamber, and more particularly to a fuel supply control device that avoids over-riching of the air-fuel mixture supplied to the sub-combustion chamber during idling operation. (Technical background of the invention and its problems) As a fuel supply control device for an internal combustion engine with a sub-combustion chamber,
For example, as disclosed in Japanese Unexamined Patent Publication No. 57-137633, the respective valve opening times of the main fuel injection valve that supplies fuel to the main combustion chamber and the auxiliary fuel injection valve that supplies fuel to the auxiliary combustion chamber are , specifications that indicate the operating condition of the engine, such as engine speed, absolute pressure in the main intake passage, engine coolant temperature, and throttle valve opening, are set to a reference value that increases as the relative pressure in the main intake passage increases. degree, exhaust concentration (oxygen concentration)
The fuel injection amount is determined by adding and/or multiplying variables and/or coefficients according to the above factors by electronic means, thereby controlling the air-fuel ratio of the air-fuel mixture supplied to the engine. Fuel supply control devices are known. Also, a secondary air control device is known that controls the idle rotation speed by supplying secondary air to the downstream side of the throttle valve in the intake passage of an internal combustion engine (for example, Japanese Patent Application Laid-open No. 58-16052
No. 6). When such a secondary air control device is applied to the above-mentioned internal combustion engine with a sub-combustion chamber, when secondary air is supplied to the main intake passage at idle, the amount of air supplied to the sub-combustion chamber does not change. The amount of air supplied to the main combustion chamber increases by the amount of secondary air, and the absolute pressure within the main intake passage increases accordingly. Therefore, even when secondary air is supplied to the main intake passage, if the absolute pressure value of the main intake passage is used to determine the amount of fuel supplied to the auxiliary combustion chamber, the air-fuel ratio of the auxiliary combustion chamber will become overrich. This may cause problems. (Summary of the Invention) The present invention has been made in view of the above-mentioned points, and the present invention has been made in view of the above-mentioned points. The purpose is to prevent this from occurring and ensure the required exhaust gas characteristics, fuel efficiency, etc. In order to achieve this object, the present invention has a main combustion chamber 2 and a sub-combustion chamber 3 communicating with the main combustion chamber 2, as shown in FIG. 3, a throttle valve 6 disposed in the middle of the main intake passage 4, and a throttle valve 6 disposed in the main intake road 4 on the downstream side of the throttle valve 6 during idling. A secondary air supply control device 16 for supplying secondary air, the main and auxiliary intake passages 4,
main and auxiliary fuel supply devices II and 12 disposed at 5 and supplying fuel to the main and auxiliary combustion chambers 2 and 3, respectively; and a pressure for detecting the downstream pressure of the throttle valve 6 in the main intake passage 4; a detection means 18 and at least the pressure detection means 18;
The amounts of fuel supplied to the main and auxiliary combustion chambers 2.3 are respectively determined according to the detected values of the main and auxiliary fuel supply devices 11.
12, the fuel supply control device includes a main fuel amount determining means and a first auxiliary fuel amount determining means that output respective control signals for operating the engine. An idle detection means for detecting the operating state and a control signal for determining the amount of fuel to be supplied to the auxiliary combustion chamber 3 and operating the auxiliary fuel supply device 12 according to only the detection value of the rotation speed detection means 19 are output. and a selection means for selecting the second auxiliary fuel amount determining means in place of the first auxiliary fuel amount determining means when the idle detecting means detects an idle operating state of the engine. The present invention provides a fuel supply control device for an internal combustion engine with a sub-combustion chamber. (Embodiment of the Invention) An embodiment of the present invention will be described in detail below with reference to FIGS. 2 to 5. In FIG. 2, reference numeral 1 indicates an internal combustion engine with a sub-combustion chamber, a main combustion chamber 2 of the engine 1 is connected with a sub-combustion chamber 3, and a spark plug 13 is provided in the sub-combustion chamber 3. A main intake passage 4 is connected to the main combustion chamber 2, and a sub-intake passage 5 is connected to the auxiliary combustion chamber 3. A main throttle valve 6 is disposed in the main intake passage 4, and an auxiliary throttle valve 7 is disposed in the auxiliary intake passage 5, respectively. These throttle valves 6 and 7 are provided in conjunction with each other, and a throttle valve opening sensor 8 is attached to the main throttle valve 6 to convert the valve opening of the throttle valve 6 into an electrical signal. This throttle valve opening sensor 8 is electrically connected to an electronic control unit (hereinafter referred to as ECU) 9, which will be described later. Slightly upstream of the intake valve 10 in the main intake passage 4, there is a main fuel injection valve II that injects fuel into the main intake passage 4; Sub-fuel injection valves 12 for injecting and supplying fuel are respectively provided. These fuel injection valves 11, 12 are communicated with a fuel tank (not shown) and are electrically connected to the ECU 9, respectively. A secondary air passage 15 is provided on the wall of the main intake passage downstream of the main throttle valve 6, and has one end 15a open to the main intake passage 4 and the other end opened to the atmosphere via the air cleaner 14. Air passage] There is a secondary air flow control valve 1 in the middle of 5.
6 is provided. This control valve 16 is a normally closed solenoid valve, and is a solenoid]
, 6a and a valve 16b that opens the secondary air passage 15 when the solenoid 1.6a is energized, and the solenoid L6a is electrically connected to the ECU 9. The secondary air passage of the main intake passage 4

An intake road absolute pressure sensor 18 is attached downstream of the open end 15a of [5] via a pipe [7], and this absolute pressure sensor 18 is electrically connected to the ECU 9. Crankshaft 16 connected to piston 1a of engine 1
An engine rotation angle position sensor 19 is attached to the
Furthermore, an 02 sensor 22 is attached to the exhaust pipe 21 connected to the main combustion chamber 2 and where the two-way catalyst 20 is disposed downstream, and an engine cooling water temperature sensor 23 is attached to the cylinder block of the engine 1. Each sensor 19, 22.23 is electrically connected to the ECU 9, respectively. FIG. 3 is a diagram showing the circuit configuration inside the ECU'9 of FIG. 2, and the engine rotational angular position from the engine rotational angular position sensor 19 of FIG. 2, for example, the TDC signal representing the top dead center (TDC,) After the waveform is shaped by the waveform shaping port M901,
The signal is supplied to a central processing unit (hereinafter referred to as rCPUJ) 903 and also to a Me counter 902 . Me counter QO2 is the engine rotation angle position sensor 19
It counts the time interval from the input of the previous TDC signal to the input of the current TDC signal, and the counted value Me
is proportional to the reciprocal of the engine speed Ne. Me counter 902 supplies this count value Me to cpU 903 via data bus 910. Throttle valve opening sensor 8 and intake road absolute pressure sensor 18 in FIG. Each output signal from various sensors such as the engine coolant temperature sensor 23 is corrected to a predetermined voltage level by a level correction circuit 904, and then sequentially supplied to an A/D converter 906 by a multiplexer 905. The A/D comparator 906 sequentially converts the output signals from each sensor described above into digital signals and sends the digital signals to the data bus 9.
10 to the CPU9C13. The CPU 903 further connects a read-only memory (hereinafter referred to as ROMj) 907 and a random access memory (hereinafter referred to as rRA, MJ) 9 via a data bus 910.
08, first drive circuit 9 connected to main fuel injection valve 11
09, second drive circuit 9 connected to the auxiliary fuel injection valve 12
11 and a third drive circuit 912 that is connected to the secondary air control valve 16 . The RAM 90g temporarily stores calculation results etc. in the CPU 903, and the ROM 9'O'7 stores various control programs executed by the CPU 903 every time a TD'C signal pulse is generated, and an idle area T i s table described below. , basic T is map, basic T i M map, etc. are stored. The c'pu 903 determines the engine operating state at idle according to the various engine parameter signals mentioned above according to the control program stored in the ROM 907, and calculates the opening time of the control valve 16 that controls the amount of secondary air. , a control signal corresponding to this calculated value is supplied to the drive circuit 912, and the drive circuit 912 supplies a drive signal to the control valve 1G to turn the control valve I6 on and off based on the control signal. In this manner, during idling, the control valve 16 is controlled to open and close as described above, secondary air is supplied to the main intake passage, and the engine speed is controlled in accordance with the idling operating state of the engine. Further, the CPU 903 determines the engine operating state and the engine load state according to the various carrot parameter signals described above according to the control program stored in the ROM 907, and determines the valve opening time T o u T of the main fuel injection valve 11.
The valve opening time TouTs of M and the auxiliary fuel injection valve 12 are calculated based on the following equations (1) and (2), respectively. Between To u T = T i MXKI + 2...
...(1) To u T s=T i s XK3 +
(2) Here, TiM and T i s indicate the basic fuel injection times of the main and auxiliary fuel injection valves 11 and 12, respectively. The T i M value is a plurality of basic fuel injection times T depending on the absolute pressure value in the main intake passage and the engine speed Ne value.
From the basic T i M map that stores i y, the main intake passage absolute pressure PEA at the time of TDC signal pulse generation this time
and the engine rotational speed Ne. On the other hand, when the engine is in an idling state, the T i s value is determined from the idle coffin and T i s table, which is set so that the T i s value increases as the engine speed decreases, as shown in Fig. 4. It is read based only on the engine speed value Ne when the TDC signal is generated this time, and when it is not in an idling state, the main intake passage absolute pressure PBA and the engine speed value Ne when the current TDC signal is generated are read from the basic Tis map. Read out based on detected value. Similar to the aforementioned basic T 1M map, the basic T i s map stores a plurality of basic fuel injection times T i s corresponding to the main intake passage absolute pressure value and the engine rotational numerical value Ne value. Basic T i M map and basic T i
T i y values and T i stored respectively in the s map
The s value is set to increase as the absolute pressure value in the main intake passage increases and as the engine speed increases. On the other hand, as mentioned above, the idle area T
The reason why the T i s value in the i s table is increased as the engine speed decreases is to compensate for the air-fuel ratio shifting to a lean value due to the increase in intake airflow per cylinder at low engine speeds. It's for a reason. Kly K2 + K3 and the above-mentioned various sensors, that is, the throttle valve opening sensor 8. A correction coefficient or correction variable that is calculated according to engine parameters from the intake road absolute pressure sensor 18, engine water temperature sensor 23, rotational angle position sensor 19, 02 sensor 22, etc., and corresponds to the engine operating state. Various characteristics such as starting characteristics, exhaust gas characteristics, fuel efficiency characteristics, engine acceleration characteristics, etc. are calculated based on a predetermined calculation formula so as to be optimal. CPU903 is deleted (1) and (2)
The control signal based on the calculation result calculated by the data bus 9
10 through the first and second drive circuits 909, 911, respectively.
supply to. Drive circuits 909 and 914 supply drive signals to the main and auxiliary fuel injection valves 11 and 12 to open the main and auxiliary fuel injection valves 11 and 12, respectively, in response to the control signals. Figure 5 shows the above-mentioned basic T i depending on the operating condition of the engine.
Select either the s map or the idle area T i s table, read out the T i s value, and read out the T i s value.
) is a flowchart of a T i s table selection subroutine for calculating the Tout value of the equation. In the control program of this embodiment, first, it is determined whether the carrot is in an idling state by determining whether the detected value Oth of the throttle valve opening sensor 8 is smaller than a predetermined opening θIDL (step 1). If the answer to step 1 is Yes, that is, if it is determined that the engine is in the idle operating state, proceed to step 2, and calculate the T i s value from the engine speed value Ne from the idle range Tjs table in FIG. Read based only on the data and proceed to step 3. If the answer to step 1 is negative (No), that is, if it is determined that the engine is not in an idling state, step 4
Then, the T i s value is read out from the aforementioned basic T i s map based on the detected values of the main intake passage absolute pressure PBA and the engine speed Ne, and the process advances to step 3. In step 3, T o u
T S value, that is, the opening time of the auxiliary fuel injection valve 12 T o u
Calculate T S and end this program. In the above-described embodiment, the idling state was detected only by the throttle valve opening, but the present invention is not limited to this, and for example, the throttle valve opening and the intake road absolute pressure, or any other combination thereof, may be used. Detection may also be made based on either one or the engine rotation speed. In addition, an example was explained in which the T'is value is determined based on the detected values of intake road absolute pressure and engine speed when the engine is not in an idling operating state. The method of the present invention can be applied as long as the amount is set in accordance with engine parameter values including at least the absolute pressure value in the intake passage. Furthermore, the secondary air control valve is not limited to one that relies on duty ratio control synchronized with the TDC signal, but may also be one that simply turns on and off, or one that controls the opening degree of the secondary air control valve to an appropriate value. good. As explained above, according to the fuel supply control device for an internal combustion engine with a sub-combustion chamber of the present invention, the rotation speed detection means detects the engine rotation speed, the idle detection means detects the idle operating state of the engine, and the second auxiliary fuel determining means that determines the amount of fuel to be supplied to the auxiliary combustion chamber only in accordance with the detected value of the number detection means and outputs a control signal for operating the auxiliary fuel supply device; A selection of selecting the second auxiliary fuel amount determining means in place of the first auxiliary fuel amount determining means that determines the amount of fuel supplied to the auxiliary combustion chamber in accordance with the pressure value in the main intake passage when an idling operating state is detected. By providing the means, it is possible to avoid over-riching of the air-fuel ratio of the auxiliary combustion chamber when secondary air is supplied to the main combustion chamber during idling operation.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to claims of the fuel supply control device according to the present invention, FIG. 2 is an overall configuration diagram showing an embodiment of the fuel supply control device according to the present invention, and FIG. 3 is the electronic control unit shown in FIG. 2. FIG. 4 is a graph showing an example of the idle area T i s table, and FIG.
The figure is a flowchart of the idle area T i s table selection subroutine. 1... Internal combustion engine with auxiliary combustion chamber, 2... Main combustion chamber, 3
... Sub-combustion chamber, 4... Main intake passage, 5... Sub-intake passage,
6... Main throttle valve, 9... Electronic control unit, 11... Main fuel injection valve, 12... Sub fuel injection valve, 15... Secondary air passage, 16... Secondary air control valve. 18... Main intake passage counter pressure sensor, 19... Engine rotation angle position sensor 9 Applicant: Honda Motor Co., Ltd. Agent Patent attorney: Toshihiko Watanabe Patent attorney: Kanji Nagato Figure 1 Figure 3 Figure 1 ,9 ↑ Figure 5

Claims (1)

[Scope of Claims] 1. It has a main combustion chamber and a sub-combustion chamber communicating with the main combustion chamber, main and sub-intake passages communicating with the main and sub-combustion chambers, respectively, and the main intake passage. Used in an internal combustion engine that includes a throttle valve disposed midway, and a secondary air supply control device that supplies secondary air into the main intake passage downstream of the throttle valve during idling, the main and sub-intake Main and auxiliary fuel supply devices disposed in passages and supplying fuel to the main and auxiliary combustion chambers, respectively; pressure detection means for detecting pressure downstream of the throttle valve in the main intake passage; and at least the pressure detection means. A main fuel amount determining means and a first sub-fuel amount determining means for determining respective fuel supply amounts to the main and sub-combustion chambers according to the detection values of the means and outputting respective control signals for operating the main and sub-fuel supply devices. A fuel supply control device comprising: a rotation speed detection means for detecting an engine rotation speed; an idle detection means for detecting an idle operating state of the engine; a second auxiliary fuel amount determination means for determining the amount of fuel supplied to the auxiliary combustion chamber and outputting a control signal for operating the auxiliary fuel supply device; and when the idle detection means detects an idle operating state of the engine. A fuel supply control device for an internal combustion engine with an auxiliary combustion chamber, characterized in that the device comprises a selection means for selecting the second auxiliary fuel amount determining means in place of the first auxiliary fuel amount determining means. 2. The fuel for an internal combustion engine with a sub-combustion chamber according to claim 1, wherein the fuel supply amount determined by the second sub-fuel amount determining means increases as the engine speed decreases. Supply control device.