JPH06625Y2 - Control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a control device for controlling an internal combustion engine.

<Prior Art> Generally, in an internal combustion engine of an automobile or the like, required characteristics of an ignition timing and a fuel supply amount differ depending on an operating state thereof.

Therefore, for example, the intake air amount Q corresponding to the engine speed N and the engine load is detected, the fuel supply amount and the ignition timing corresponding to these values are calculated to obtain the control amount, and the engine is controlled. (Japanese Patent Publication No. 55-36814, Japanese Patent Laid-Open No. 60-1)
62059 see each publication). Further, the engine speed N and the basic ignition timing A _dv data for the basic injection pulse width T _p are obtained in advance by experiments and stored as a map in a memory, and the map is searched according to the operating state of the engine. ,
The engine is controlled based on the map data (see Japanese Patent Laid-Open No. 55-112861). Furthermore,
At start (cranking), no load (idling),
By preparing a separate calculation formula or table map for the basic ignition timing during load operation and setting the ignition timing by selecting the basic ignition timing in each of the above operating conditions according to the operating conditions of the engine, (See Japanese Patent Laid-Open Nos. 60-162059 and 55-139971).

By the way, the ignition timing at no load is set to the retard side as shown by the broken line in FIG. 7 in order to stabilize the idle speed, and is set to a predetermined value according to the water temperature and the speed. There is. On the other hand, the ignition timing under normal load is set to the advance side as shown by the solid line in the figure in order to obtain high torque and high efficiency, and the combustion of the air-fuel mixture becomes slower as the load becomes lower. Therefore, the best ignition timing is set on the considerably advanced side.

<Problems to be Solved by the Invention> However, in such a conventional control apparatus for an internal combustion engine, when controlling the engine output, first, the opening of the throttle valve is controlled to control the intake air amount of the engine. The fuel supply amount and the ignition timing are controlled according to the change in the intake air amount.Therefore, when the load is extremely low near the fully closed throttle valve, the throttle valve opening changes slightly. On the other hand, the change rate of the air passage area of the throttle valve is large, and the suction negative pressure is also large, so the intake air amount changes greatly and there is a difference between the no-load and ignition timing under load. Therefore, there has been a problem that the engine output (torque generated) suddenly changes and the maneuverability deteriorates.

This invention was made in view of such conventional problems, and when the engine is in a predetermined extremely low load state close to an unloaded state, the operating angle of the slot pedal is fully closed with the throttle valve fully closed. It is an object of the present invention to solve the above problems by setting the ignition timing according to the above.

<Means for Solving Problems> Therefore, according to the present invention, as shown in FIG.
Operating state detection means a for detecting the operating state of the engine, slot operation angle detection means b for detecting the operation angle of the throttle pedal, and slot valve opening for opening the slot valve when the slot operation angle is a predetermined opening or more. Ignition timing for setting the basic ignition timing based on the operating condition of the setting means c and the engine, and for setting the ignition timing according to the throttle operating angle when the throttle operating angle is smaller than the predetermined opening degree. The setting means d and the ignition means e for igniting the air-fuel mixture based on the output of the ignition timing setting means are provided.

<Operation> In the present invention, when the operation angle of the throttle pedal is in an extremely low load state smaller than the predetermined opening, the ignition timing is set according to the throttle operation angle with the throttle valve fully closed. Therefore, in an extremely low load operation region, abrupt rise of generated torque is suppressed, and drivability and maneuverability are improved.

<Example> Hereinafter, the present invention will be described with reference to the drawings.

2 to 6 are views showing an embodiment of the present invention. First,
The configuration will be described. In FIG. 2, reference numeral 1 is an operating state detecting means, and the operating state detecting means 1 is composed of a plurality of sensors for detecting various parameters related to the operating state of the engine. That is, the operating state detecting means 1 is composed of a crank angle sensor 2, an air flow meter 3, a throttle operating angle sensor (slottle operating angle detecting means) 4, and an idle switch 5. The crank angle sensor 2 is set at a predetermined position before the compression top dead center (TDC) of each cylinder at every explosion interval (120 ° crank angle in a 6-cylinder engine, 180 ° in a 4-cylinder engine), for example, at BTDC 70 °, [H] level. In addition to outputting the reference position signal C _a that becomes a pulse of, the unit signal C ₁ that becomes a pulse of [H] level is output for each unit angle (for example, 1 °) of the crank angle. The engine speed N can be known by counting the pulses of the signal C _a , and this processing is performed by the control unit 11 described later. Air flow meter 3 detects the intake air quantity Q _a to body representing engine load, Surotsutoru operating angle sensor 4 detects the operation angle TVO of Surotsutorupedaru. Further, the idle switch 5 is turned on when the engine is in the idling state, and outputs an idle signal corresponding to the state to the control unit 11.

The signals from the crank angle sensor 2, the air flow meter 3, the throttle operation angle sensor 4, and the idle switch 5 are input to the control unit 11, which has a function as an ignition timing setting means, and the CPU 12, ROM 13 , RAM 14, an input / output interface, a register, a counter, an input / output control circuit 15 incorporating an A / D converter and the like. CPU12 is ROM13
The required external data is fetched from the input / output control circuit 15 according to the program written in
While exchanging data with the M14, a processing value required for ignition timing control is arithmetically processed, and the processed data is output to the input / output control circuit 15 as necessary. The input / output control circuit 15 receives the signal from the operating state detecting means 1 and outputs the injection signal S _i and the ignition signal S _p from the input / output control circuit 15. The ROM 13 stores the calculation program in the CPU 12, and the RAM 14 stores the data used for the calculation in the form of a map or the like. Note that a part of the RAM 14 is composed of, for example, a non-volatile memory, and retains the stored contents (learned value and the like) even after the calculation is stopped. On the other hand, the injection signal S _i is input to the drive circuit 16 and the drive circuit 1
Reference numeral 6 is composed of a driving power transistor 17, a battery 18, and the like. The drive circuit 16 amplifies the signal from the input / output control circuit 15 into an injection signal sufficient for fuel injection and supplies the amplified injection signal to the injector 19. Also, the ignition signal S _p
Is inputted to the ignition means 21, and the ignition means 21 is composed of spark plugs 22a to 22d, an ignition coil 23, a battery 18, a dust collector 24, and a power transistor 25. The ignition means 21 controls ON / OFF of the power transistor 25 based on the ignition signal S _p to control the ignition coil 2
Together to generate a high voltage P _i on the secondary side of the 3, to ignite the fuel-air mixture is supplied to the ignition plug 22a~22d the high voltage P _i and distributed by Day string Byuta 24. In addition, this ignition timing control (ON-OFF of the power transistor 25)
Control), as shown in FIG. 3, ignition timing data ADD
Is a set ADV (advance value) register 26, a counter 27 which is reset by a reset pulse and counts an angle (1 pulse) signal C ₁ from the crank angle sensor 2,
When the counter 27 is reset, the power transistor 25 is turned on, and when the ignition timing data ADD set in the ADV register 26 and the count value of the counter 27 match, the power transistor 25 is turned off. Become.

Next, the throttle valve opening setting means will be described with reference to FIG. In the figure, the throttle valve shaft passing through the slot chamber 41 has a double structure, and is composed of an outer outer shaft 42 and an inner inner shaft 43, which are rotatably attached to each other. A butterfly type throttle valve 44 and a second throttle drum 46 are fixed to the outer shaft 42. On the other hand, the inner shaft 43 has a first slotted drum 45 having an engagement piece 47 which engages with the second slotted drum 46 at a predetermined opening θ _o or more at one end, and an operating angle of the slotted bed pedal 40 at the other end. A slot operation angle sensor 4 such as a potentiometer for detecting is attached. The throttle operating angle sensor 4 can also be directly attached to the throttle pedal 40. Further, the first throttle drum 45 and the second throttle drum 46 are urged in the direction in which the throttle valve 44 is closed (clockwise in the left diagram in FIG. 4) by the restoring force of the return springs 50 and 51, respectively, and the stopper is stopped. Abutting against each other 48, they are held in the fully closed position. Here, the operation force of the throttle pedal 40 is given by the force of pulling the throttle wire 49,
It is a force for rotating the slottle drum 45 in the opening direction.
Only the first throttle drum 45 rotates until the engagement piece 47 contacts the second throttle drum 46, and the operation angle of the throttle pedal 40 is detected by the throttle operation angle sensor 4, and this detection signal is detected. Is output to the control circuit 15. When the operation angle of the first throttle drum 45 becomes equal to or larger than the predetermined opening θ _o , the engaging piece 47 contacts the second throttle drum 46, and the throttle valve 44 rotates in conjunction with the operation of the throttle pedal 40. Is configured.

Next, the operation will be described.

FIG. 5 is a flow chart showing an ignition timing control program written in the ROM 13, and this program is executed once every predetermined time.

First, at P ₁ , whether the slot operation angle TVO is [0 °] or not (T
VO = 0), and when TVO = 0, it is judged that the throttle operating angle is fully closed and there is no load (idling). P ₂
Then, the ignition timing ADV _IDLE during idling is calculated, and this ADV _IDLE is set in the ADV register 26 at P ₃ to end the present processing. Here, the calculation of ADV _IDLE is performed by allocating a constant ignition timing depending on the cooling water temperature T _w and the engine speed N, as in the conventional example. The throttle operating angle sensor 4 is used to determine the idling state of the engine.
The idle signal from the idle switch 5 may be used instead of the fully closed information from the.

On the other hand, when TVO ≠ 0, it is determined that there is no load, and the throttle operation angle TVO is compared with a predetermined opening angle θ _{th in} P ₄ , and when TVO is smaller than θ _th (TVO <θ _th ). Judging that the engine is in an extremely low load condition, which is close to that when there is no load, P ₅
Calculates the ignition timing ADV _TVO at an extremely low load, and this ADV _TVO is calculated at P ₆ by the ADV register 26 in the input / output control circuit 15.
To complete the process. Here, the ignition timing ADV _TVO at an extremely low load increases or decreases according to the throttle operation angle TVO, and the calculation method thereof is, for example, as shown in () to (), and the processing capacity of the CPU and the required ignition It can be used properly according to the accuracy of timing control.

() A method of interpolating by the slot operation angle TVO based on the calculation result ADV _IDLE of the ignition timing when there is no load and the calculation result ADV _MAP of the ignition timing when there is a load, which is expressed by the following equation, for example.

() The minimum ignition timing ADV _Min is set, the throttle operation angle TVO is larger than the value of ADV _Min , and the ignition timing calculation result under load ADV _MAP (where ADV _TVO <ADV
_A method of advancing the ignition timing in proportion to TVO in a range smaller than ( _MAP ), for example, as shown in the following equation.

ADV _TVO = ADV _Min + k × TVO ... where k: proportional constant () A table map that stores the ignition timing based on the throttle operating angle TVO and the engine speed N, and the detected TVO and the speed N are used. The ignition timing is searched for from this table map and obtained. When TVO ≧ θ _{th in} P ₄ , it is judged that the vehicle is not in an extremely low load state, P ₇ calculates the ignition timing ADV _MAP under normal load, and in P ₈ this ADV _MAP is set in the ADV register 26. This processing ends. In addition, AD
The calculation of V _MAP is obtained by a method of searching a table _{map with} the engine speed N and the intake air amount Q _a representing the engine load, as in the known example.

As described above, the throttle operating angle TVO is detected, and the throttle operating angle TVO is larger than the fully closed state and is larger than the predetermined opening angle θ _th (in this embodiment, the opening opening θ _o is the same as the opening opening θ _o ). When it is small, it is determined that the engine load is extremely low, and the ignition timing ADV _TVO at the extremely low load is calculated and set according to the throttle operation angle TVO. Therefore, as shown in FIG. 6, the slot operation angle AVO is θ _th (=
At very low loads smaller than θ _o ), the throttle valve 44
Is held in a fully closed state, and the ignition timing ADV _TVO smoothly shifts between the idling ignition timing ADV _IDLE and the load ignition timing ADV _MAP in accordance with the throttle operating angle TVO to output the engine output (torque). Also gradually increases. On the other hand, the throttle operation angle TVO is θ _th (= θ _o ).
If it becomes above, the engaging piece 47 of the 1st throttle drum 45 will contact the 2nd throttle drum 46, and the intake air amount will increase by interlocking with the operation of the throttle pedal 40 and rotating the throttle valve 44. The ignition timing ADV _MAP at the time of load can be set according to the throttle operation, and the torque according to the intake air amount can be obtained.
As a result, it is possible to prevent the occurrence of shock and obtain good drivability without delaying the response to the throttle operation.

By the way, in the engine for automobiles, in order to stabilize the rotation during idling, even if the throttle valve is fully closed, a relatively large amount of air bypasses the throttle valve and is sucked into the engine. However, it generates enough torque to drive at low speed. By effectively utilizing this surplus torque, acceleration and deceleration can be performed only by controlling the ignition timing as in the present embodiment without opening and closing the throttle valve to increase the fuel consumption with slight acceleration and deceleration on a congested road or the like. It becomes possible and the fuel consumption can be saved.

In this embodiment, as shown in FIG. 6, the opening θ _th for setting the ignition timing at the time of extremely low load and the opening θ _o for opening the throttle valve are set to be the same. , It is not necessarily the same, for example, in the case of a large displacement engine with a large generated torque, θ _th is made larger than θ _{o and the} torque is changed by changing the ignition timing even in the region where the throttle valve opens. It can also be gentle. Also,
Although the fuel injection system is shown as the fuel supply system, it can be applied to a carburetor.

<Effect> According to the present invention, the throttle valve is opened when the operating angle of the throttle pedal is equal to or greater than a predetermined opening degree, and when the throttle operating angle is smaller than the predetermined opening degree, ignition is performed according to the throttle operating angle. Since the timing is set, it is possible to suppress the rapid rise of the generated torque without impairing the responsiveness of the engine to the throttle operation in the extremely low load operating region, and to improve drivability and maneuverability. It is possible to save fuel consumption.

[Brief description of drawings]

FIG. 1 is a basic conceptual diagram of the present invention, and FIGS. 2 to 5 are diagrams showing an embodiment of a control device for an internal combustion engine according to the present invention.
FIG. 3 is an overall block diagram, FIG. 3 is a block block diagram of an essential part of an input / output control circuit, FIG. 4 is a block diagram of the throttle valve opening setting means, and FIG. 5 is a program for ignition timing control thereof. A flow chart, FIG. 6 is a characteristic diagram of the ignition timing and the throttle valve opening, and FIG. 7 is a characteristic diagram of the ignition timing of the conventional control device for the internal combustion engine. 1 ... Operating state detecting means, 4 ... Slot operating angle sensor (slotting operating angle detecting means), 11 ... Control unit (ignition timing setting means), 21 ... Ignition means.

Claims (1)

[Scope of utility model registration request] 1. A driving state detecting means for detecting an operating state of an engine; b) a slott operating angle detecting means for detecting an operating angle of a slottling pedal; and c) a slottling valve having a slottling operating angle equal to or larger than a predetermined opening. And a slot ignition valve opening setting means for opening the valve, and d) setting the basic ignition timing based on the operating state of the engine, and when the slotl operating angle is smaller than the predetermined opening, the slotl operating angle is set. A control device for an internal combustion engine, comprising: an ignition timing setting means for setting an ignition timing according to the above; and e) an ignition means for igniting an air-fuel mixture based on an output of the ignition timing setting means.