JP3736988B2 - Intake adjustment valve control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for avoiding abnormal combustion in an internal combustion engine, and more particularly to an apparatus for controlling the opening of an intake adjustment valve such as a throttle valve.
[0002]
[Prior art]
In a normal internal combustion engine, the accelerator pedal is mechanically connected directly to the throttle valve. Therefore, the opening degree of the throttle valve proportional to the depression amount of the accelerator pedal can be obtained. However, when sudden acceleration is performed by depressing the accelerator pedal at a stroke from a low rotational speed such as idling while the engine is warmed up, the inside of the cylinder bore becomes a high-temperature and high-pressure state, and the rotation for performing combustion immediately increases sufficiently. There is a risk that abnormal combustion phenomena such as knocking, pre-ignition, post-ignition, and self-ignition occur in the cylinders that are not.
[0003]
Therefore, in Japanese Patent Publication No. 6-72563, an electronic mechanism for controlling the opening of the throttle valve is provided independently of depression of the accelerator pedal, and when the accelerator pedal is depressed from a low speed state to perform rapid acceleration, the throttle valve Discloses a technique for preventing knocking by releasing the engine at a reduced speed relative to depression of the accelerator pedal.
[0004]
[Problems to be solved by the invention]
However, according to Japanese Examined Patent Publication No. 6-72563, the deceleration of opening the throttle valve with respect to the depression of the accelerator pedal during sudden acceleration is performed at a constant rate. That is, the throttle valve opening from the depression of the accelerator pedal is set to gradually increase to the final opening at a constant speed. Therefore, it takes time until the throttle valve reaches the maximum opening, and there is a problem that sufficient acceleration performance cannot be obtained.
[0005]
An object of the present invention is to obtain desired acceleration performance while suppressing abnormal combustion during rapid acceleration.
[0006]
[Means for Solving the Problems]
According to the present invention, the technical means described in claim 1 is employed to solve the above-mentioned problems. According to this technical means, at the time of sudden acceleration, the opening speed of the intake adjustment valve is reduced immediately thereafter, and the opening speed is increased with the passage of time so that the combustion chamber in the cylinder performing combustion immediately after acceleration. Abnormal combustion is suppressed by preventing the pressure from becoming too high, and then the acceleration performance can be ensured by increasing the opening speed of the intake control valve.
Further, by incorporating the engine temperature factor, the opening speed of the intake control valve can be adjusted only when abnormal combustion is likely to occur.
[0007]
According to the second aspect of the present invention, the smaller one of the accelerator pedal operation amount and the allowable opening is used as the intake adjustment valve opening, thereby preventing abnormal combustion immediately after sudden acceleration and thereafter adjusting the intake air. Optimum acceleration performance can be obtained by controlling the opening of the valve by the amount of accelerator pedal operation.
[0008]
According to the third aspect of the present invention, an appropriate opening degree of the intake adjustment valve can be obtained by reflecting the engine speed in the determination of the allowable opening degree θ of the intake adjustment valve. According to the invention, it is possible to obtain a good acceleration performance by determining the opening speed of the intake regulating valve based on the rotational speed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, 10 is a cylinder block, 12 is a piston, 16 is a cylinder bore, 18 is a cylinder head, 20 is a spark plug, 22 is an intake valve, 23 is an intake camshaft, 24 is an intake port, 25 is a fuel injection valve, 26 Is an exhaust valve, and 28 is an exhaust port. The intake port 24 is connected to an intake manifold 32, the intake manifold 30 is connected to a throttle body 34, and a throttle valve 36 is disposed in the throttle body 34. The throttle valve 36 (the intake adjustment valve of the present invention) is capable of controlling the amount of air flowing through the throttle body 34 independently of the depression operation of the accelerator pedal 37. That is, the rotation shaft of the throttle valve 36 is connected to the drive shaft of the throttle valve drive motor 38, and the rotation angle position of the rotation shaft of the throttle valve 36, that is, the opening degree of the throttle valve 36 is controlled.
[0010]
The control circuit 40 can be constituted by a microcomputer, and the electronic control circuit 40 according to the present invention controls the throttle valve drive motor 38 so as to control the opening degree of the throttle valve in accordance with the operation condition detected by each operation condition sensor. It operates so as to output a drive signal. As the operating condition sensor, the rotational speed sensor 42 is provided in the vicinity of the intake camshaft 23 in this embodiment, and a signal corresponding to the rotation of the intake camshaft 23 that rotates once by two rotations of the crankshaft is sent to the electronic control circuit 40. Entered. The detection end of the engine water temperature gauge 44 extends to the cooling water jacket 10-1 of the cylinder block 10, and a signal corresponding to the engine cooling water temperature is introduced into the electronic control circuit 40. An accelerator sensor 45 for detecting the amount of depression of the accelerator pedal 37 is connected to the accelerator pedal 37, and a signal corresponding to the amount of depression of the accelerator pedal 37 is input to the electronic control circuit 40.
[0011]
FIG. 2 is a flowchart for explaining the operation in the first embodiment, and this routine is executed every predetermined time interval (for example, 6 milliseconds). Step 100 determines whether or not the engine water temperature THW detected by the engine water temperature sensor 44 is higher than a predetermined value (for example, 80 ° C.) as to whether or not the internal combustion engine is under warm operation. In step 110, the accelerator pedal depression amount (throttle valve opening command amount) detected by the accelerator pedal depression amount sensor 45 determines whether or not the accelerator pedal 37 has instructed rapid opening (rapid acceleration) of the throttle valve. It is determined by whether or not it is large. When the internal combustion engine is cold or warmed up but does not accelerate rapidly, the routine proceeds to step 120 where the accelerator pedal depression amount detected by the sensor 45 is output as it is to the drive motor 38 as the throttle valve operation amount. In other words, when the internal combustion engine is cold or warm, it is the same as a normal internal combustion engine in which the opening degree of the throttle valve 36 is controlled in proportion to the amount of depression of the accelerator pedal 37 when the acceleration condition is not abrupt. It becomes operation.
[0012]
When the internal combustion engine is suddenly accelerated during warm operation, the routine proceeds to step 130 where the accelerator pedal depression amount (throttle valve opening command amount) θ _A detected by the accelerator pedal depression amount sensor 45 is input. The engine speed detected by the number sensor 42 is input. In the next step 150, an allowable value θ of the throttle valve opening corresponding to the engine speed is calculated. The allowable value θ of the throttle valve opening is the following equation for the engine speed:
θ = k × R _ev (1)
Is calculated by Here, k is a fitness coefficient, and its value can be determined by experiment. In step 160, the smaller value of the accelerator pedal depression amount θ _A (throttle valve opening instruction amount) detected in step 103 and the throttle valve opening allowable value θ calculated in step 150 is the throttle valve operation amount. Is output.
[0013]
If the rise of the engine speed after acceleration by the above method is insufficient, the throttle valve opening speed dθ / dt is set to dθ / dt = k ′ × R _ev (2)
You may make it control like this. Similarly, k ′ is a fitness coefficient, and its value can be determined by experiment.
[0014]
FIG. 3 is a timing chart for explaining the operation by the control of FIG. (B) indicates the amount of depression of the accelerator pedal, and when p is the acceleration start time from idle operation, the amount of depression of the accelerator pedal immediately reaches 100%. On the other hand, the rotation speed is increased as shown in (b). Further, the opening speed dθ _R / dt of the throttle valve opening θ _R is gradually increased so as not to exceed the allowable value dθ / dt corresponding to the rotational speed calculated in step 150 of FIG. (D) schematically shows a change in stroke of each cylinder from the first cylinder (# 1) to the fourth cylinder (# 4) that occurs every 180 ° in crank angle. In this embodiment, since the throttle valve opening after the start of acceleration is largely limited at the beginning, the intake stroke is executed at the acceleration start time p in the example shown in the figure, so the first cylinder (# 1) having a low rotation speed is used. Since the combustion chamber has a high pressure, it is possible to suppress the occurrence of abnormal combustion phenomena such as knocking, pre-ignition, post-ignition, and self-ignition. Further, since the throttle valve opening rapidly increases as the number of rotations increases from the start of acceleration, it is possible to ensure the necessary acceleration performance.
[0015]
FIG. 4 shows the operation when the accelerator pedal (A) and the throttle valve (B) are interlocked in the prior art. In this case, the engine rotation occurs in the first cylinder (# 1) that performs the intake stroke immediately after acceleration. When the number is low, the combustion chamber becomes high pressure, and abnormal combustion phenomena such as knocking, pre-ignition, post-ignition, and self-ignition cannot be avoided. FIG. 5 illustrates the operation of an electronic mechanism that controls the opening degree of the throttle valve as disclosed in Japanese Patent Publication No. 6-72563. In this case, the opening degree of the throttle valve is small after the acceleration is started. The combustion chamber can be prevented from becoming high pressure, and abnormal combustion can be suppressed. However, since the throttle valve is only slowly opened (b), the acceleration performance is insufficient.
[0016]
FIG. 6 illustrates the relationship between the accelerator pedal operation amount and the throttle valve operation amount allowable value according to the engine rotation speed in the first embodiment. That is, the accelerator pedal operation amount θ _A changes linearly with respect to time as indicated by a, while the throttle valve allowable opening θ corresponding to the engine rotational speed becomes the throttle valve opening speed as time elapses as indicated by curve b. Is set to increase. Therefore, the final throttle valve opening degree θ _R after the guard process in step 160 seems to be a thick solid line. That is, in the initial stage of acceleration, the throttle valve allowable opening θ corresponding to the engine speed is controlled according to the curve b independently of the depression of the accelerator pedal, and when θ> θ _A is satisfied, the straight line corresponding to the depression of the accelerator pedal thereafter. The throttle valve opening θ _R is controlled along a.
[0017]
FIG. 7 shows a flowchart for explaining the operation of the electronic control circuit in the second embodiment. The difference is that 200 steps are added to the flowchart of FIG. 2 in the first embodiment. That is, in the first embodiment, the throttle valve opening speed is updated every predetermined time (for example, every 6 milliseconds) after the start of the rapid acceleration operation. In the second embodiment of FIG. Therefore, the update of the throttle valve opening speed after the start of the rapid acceleration operation is performed every time the crankshaft rotates 180 °.
[0018]
FIG. 8 is a timing chart for explaining the operation of the second embodiment. That is, when sudden acceleration is started, the throttle valve is gradually opened at a small throttle valve opening speed calculated by the engine speed at that time in the engine of the first 180 ° crank angle, and at that time, the intake stroke is started. In a certain cylinder, the combustion chamber is maintained at a low pressure, and abnormal combustion can be prevented. In the next 180 ° crank angle engine, the throttle valve is opened at a larger throttle valve opening speed than the first crank angle engine. Therefore, necessary acceleration performance can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a throttle valve control device for an internal combustion engine according to a first embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the first embodiment;
FIG. 3 is a timing chart for explaining the operation of the first embodiment;
FIG. 4 is a timing chart for explaining a conventional operation in which throttle valve opening speed control is not performed.
FIG. 5 is a timing chart for explaining a conventional operation for performing throttle valve opening speed control.
FIG. 6 is a diagram illustrating guard processing in the first embodiment.
FIG. 7 is a flowchart for explaining the operation of the second embodiment;
FIG. 8 is a timing chart for explaining the operation of the second embodiment.
[Explanation of symbols]
14 ... Cylinder bore 23 ... Intake cam shaft 36 ... Throttle valve 37 ... Accelerator pedal 38 ... Throttle valve drive motor 40 ... Electronic control circuit 42 ... Engine speed pick-up 44 ... Engine water temperature gauge 45 ... Accelerator sensor

Claims (4)

An intake adjustment valve that can control the intake air amount independently of the operation of the accelerator pedal, an intake adjustment valve control means that controls the opening of the intake adjustment valve according to the operation of the accelerator pedal, and the temperature of the internal combustion engine Temperature measurement means, determination means for determining whether or not the engine is warm based on the measured engine temperature, means for detecting when the accelerator pedal is rapidly operated, and irrelevant to the operation of the accelerator pedal when the accelerator pedal is rapidly operated And an intake adjustment valve opening speed control means for decelerating and opening the intake adjustment valve,
The intake adjustment valve opening speed control means is a rotation speed measurement means for measuring the rotation speed of the internal combustion engine, and an opening setting for setting the allowable opening or the allowable opening speed of the intake adjustment valve according to the measured engine speed. Consists of means,
When the determination means determines that the operation is warm, the intake adjustment valve opening speed control means opens the intake adjustment valve according to the allowable opening according to the engine speed as time elapses from the operation of the accelerator pedal. An intake control valve control device for an internal combustion engine, wherein an operation signal to the intake control valve control means is formed so as to increase the speed.   2. The internal combustion engine according to claim 1, further comprising means for determining the opening of the intake adjustment valve by a smaller one of an allowable opening according to an operation amount of an accelerator pedal and an engine speed. Intake regulating valve control device. In the invention according to claim 1, the allowable opening θ of the intake adjustment valve by the intake adjustment valve opening speed control means is:
θ = k × R _ev
k: constant R _ev : an intake regulating valve control device for an internal combustion engine, which is limited by the engine speed. In the first aspect of the present invention, the allowable opening speed dθ / dt of the intake adjusting valve by the intake adjusting valve opening speed control means is:
dθ / dt = k ′ × R _ev
k ′: constant R _ev : an intake regulating valve control device for an internal combustion engine, which is limited by the engine speed.

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