JP2002021692A - Knocking control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease processing of unnecessary angle of lead and angle of lag, to prevent the occurrence of the damage of an engine due to an unnecessary angle of lead, to decrease the torque fluctuation of an engine, to control an ignition timing in consideration of an influence by a warming-up state, and to effect control of an ignition timing corresponding to a secular change. SOLUTION: A knock sensor is provided to detect knocking of an engine. A rate of change of a knock strength is calculated from a preceding knock strength detected by the knock sensor before the ignition timing of the engine is advanced and a current knock strength detected by the knock sensor after the ignition timing of the engine is advanced. From the rate of change of a knock strength, a next knock strength generated when an ignition timing is advanced next time is calculated from a rate of change of a knock strength. By comparing a next knock strength and a knock strength limit value with each other, a control means is provided to control a next ignition timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knocking control device, and more particularly, to a process for reducing unnecessary advance and retard angles, eliminating damage to the engine due to unnecessary advance angle, and reducing engine torque. The present invention relates to a knocking control device capable of reducing fluctuation.

[0002]

2. Description of the Related Art Drivability of an engine mounted on a vehicle or the like is reduced when knocking occurs. Therefore, some engines are provided with a knocking control device that suppresses knocking. The knocking control device controls the ignition timing to be advanced until knocking occurs, and controls the ignition timing to be retarded when knocking occurs and the knock intensity exceeds a certain set value.

Thus, the knocking control device maximizes the output performance of the engine when knocking does not occur, and protects the engine when knocking occurs.

[0004] As such a knocking control device,
JP-A-7-139456, JP-A-8-16597
There is one disclosed in Japanese Patent Publication No. 4 (JP-A) No. 4 (1994).

Japanese Unexamined Patent Publication No. Hei 7-139456 discloses that when the knocking frequency is high, the retard amount when knocking occurs is large, the advance speed when knocking does not occur is small, and the knocking frequency is low. In this case, the retard amount when knocking occurs is reduced, and the advance speed when knocking does not occur is increased.

[0006] Japanese Unexamined Patent Publication No. Hei 8-165974 determines a knocking margin from the difference between the maximum ignition angle at which knocking occurs and the actual ignition angle, and increases the advance amount as the knocking margin increases. When knocking occurs, the ignition angle is rapidly retarded.

[0007]

However, the conventional knocking control device controls the ignition timing to be retarded after knocking actually occurs. In this case, the knocking control device does not retard the timing until the knock strength becomes severe for the engine, and frequently repeats the unnecessary advance and retard processing.

For this reason, a conventional knocking control device is
There is a disadvantage that the engine is damaged and the torque fluctuation of the engine is increased.

[0009]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides a knock sensor for detecting knocking of an engine, and the knock sensor is provided before the ignition timing of the engine is advanced. A knock intensity change rate is calculated from the detected previous knock intensity and the current knock intensity detected by the knock sensor after the ignition timing of the engine is advanced, and the next ignition timing is calculated from the knock intensity change rate. Calculating the next knock intensity generated when the angle is advanced, comparing the next knock intensity with the knock intensity limit value, and providing control means for controlling the next ignition timing. I do.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a knocking control device according to the present invention, the control means controls the advance of the previous knock intensity detected by the knock sensor before the advance of the engine ignition timing and the advance of the engine ignition timing. A knock intensity change rate is calculated from the current knock intensity detected by the knock sensor later, and a next knock intensity generated when the ignition timing is advanced next time is calculated from the knock intensity change rate, By controlling the next ignition timing by comparing the next knock strength with the knock strength limit value, it is possible to accurately determine the possibility of advance, and to appropriately perform the advance and retard processing. It is possible,
Further, the ignition timing can be controlled to reflect the current state of the engine.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 show an embodiment of the present invention. In FIG. 7, 2 is an engine mounted on a vehicle (not shown), 4 is a cylinder block, 6 is a cylinder head, 8 is a head cover, 10 is a piston, 12 is a combustion chamber, 14 is an intake port, 16 is an exhaust port, and 18 is An intake valve 20 is an exhaust valve.

The engine 2 is provided with an intake passage 32 communicating with the intake port 14 by sequentially connecting an air cleaner 22, an intake pipe 24, a throttle body 26, a surge tank 28, and an intake manifold 30 as an intake system. A throttle valve 34 is provided in the intake passage 32 of the throttle body 26. The engine 2 includes an exhaust manifold 36, an exhaust pipe 38, and a catalytic converter 40 as an exhaust system.
Are sequentially connected, and an exhaust passage 42 communicating with the exhaust port 16 is provided.

The engine 2 is provided with a supercharger 44. The supercharger 44 has a compressor 46 provided in the middle of the intake pipe 24 and a turbine 48 provided in the middle of the exhaust pipe 38. The engine 2 has an intercooler 50 in the intake pipe 24 downstream of the compressor 46.

The supercharger 44 has a bypass passage 52 which bypasses the turbine 48 and communicates with the exhaust passage 42, and a waste gate valve 54 which opens and closes the bypass passage 52.
And an actuator 56 for opening and closing the waste gate valve 54 is provided. Actuator 56
Drives the waste gate valve 54 to open and close by the supercharging pressure in the intake passage 32 on the downstream side of the compressor 46, and controls the supercharging pressure so as not to exceed the set supercharging pressure.

The engine 2 is provided with an ignition coil 58 attached to the head cover 8. The engine 2 also has a first blow-by gas passage 62 that connects the inside of the head cover 8 and the intake passage 32 of the surge tank 28 via the PCV valve 60, and connects the inside of the head cover 8 with the intake passage 32 immediately downstream of the air cleaner 22. A communicating second blow-by gas passage 64 is provided.

The engine 2 has a fuel injection valve 66 provided in the intake manifold 30 so as to be directed to the combustion chamber 12.
The fuel injection valve 66 is connected to a fuel tank 72 by a fuel supply passage 70 via a fuel distribution pipe 68. In the fuel tank 72, a fuel pump 74, a fuel filter 76, and a fuel pressure adjusting unit 78 are provided.

The fuel in the fuel tank 72 is supplied to a fuel pump 74.
The dust is removed by the fuel filter 76, the dust is removed by the fuel filter 76, the pressure is adjusted by the fuel pressure adjusting unit 78, supplied to the fuel supply passage 70, and distributed to the fuel injection valve 66 of each combustion chamber 12 by the fuel distribution pipe 68. Supplied. The surplus fuel whose pressure has been adjusted by the fuel pressure adjusting unit 78 is
It is returned into the fuel tank 72.

The fuel tank 72 communicates with one end of an evaporation passage 82 through a two-way check valve 80. The other end of the evaporation passage 82 communicates with the canister 84. One end of the purge passage 86 communicates with the canister 84. The other end of the purge passage 86 communicates with the intake passage 32 of the throttle body 26. A one-way valve 88 for adjusting the purge amount is provided in the middle of the par passage 80.

The engine 2 includes a throttle valve 34
And an idle air passage 90 that connects the intake passage 32 of the throttle body 26 and the intake passage 32 of the surge tank 28 to bypass the air passage. In the middle of the idle air passage 90, an idle air amount control valve 9 for adjusting an idle air amount is provided.
2 are provided.

The engine 2 is provided with a crank angle sensor 94 for detecting a crank angle and an engine speed, a water temperature sensor 96 for detecting a coolant temperature, and a throttle sensor 98 for detecting a throttle opening of the throttle valve 34. Temperature sensor 100 for detecting intake air temperature
And an intake pressure sensor 102 for detecting intake pressure is provided.
An O2 sensor 104 for detecting the oxygen concentration in the exhaust gas is provided;
Knock sensor 106 for detecting knocking of engine 2
Is provided.

The ignition coil 58, fuel injection valve 66, fuel pump 74, idle air amount control valve 92, crank angle sensor 94, water temperature sensor 96, throttle sensor 98, intake temperature sensor 100, intake pressure sensor 102, and O
The two sensors 104 and the knock sensor 106 are connected to control means 110 constituting a knocking control device 108. A battery 116 is connected to the control means 110 via a main switch 112 and a fuse 114.

The knocking control device 108 controls the control means 1
10, the crank angle sensor 94 to the knock sensor 1
In addition to controlling the fuel injection amount, ignition timing, and idle air amount according to the operating state,
Control knocking.

The knocking control device 108 is provided with the control means 1
10, the knock intensity detected by the knock sensor 106 before the ignition timing of the engine 2 is advanced and the knock sensor 10 after the ignition timing of the engine 2 is advanced.
6 calculates the knock intensity change rate from the current knock intensity detected, calculates the next knock intensity generated when the ignition timing is advanced next time from the knock intensity change rate, and calculates the next knock intensity. Then, the next ignition timing is controlled by comparing the knock intensity with the knock intensity limit value.

When the calculated next knocking intensity exceeds the knocking intensity limit value, the control means 110 controls the current ignition timing to be maintained, and the calculated next ignition timing is changed to the current ignition timing. When the predetermined time has elapsed after the control is performed to maintain the ignition timing, the next ignition timing is controlled to be advanced from the current ignition timing.

When the calculated next knocking intensity is equal to or less than the knocking intensity limit value, the control means 110 controls the next ignition timing to be advanced from the current ignition timing, and the knock sensor 106 When the detected knock intensity exceeds the knock intensity limit value, control is performed to retard the next ignition timing.

Next, the operation of this embodiment will be described.

The knocking control device 108 includes the control unit 1
As shown in FIG. 1, when the control is started (200) as shown in FIG. 1, while the engine 2 is operating (202), it is determined whether or not the operation area is the knock control area (20).
4).

If it is not the knock control area and the judgment (204) is NO, the process returns to the step (202). If it is the knock control area and the determination (204) is YES, knock is detected by knock sensor 106 (206), and it is determined whether or not the detected knock strength exceeds the knock strength limit value (208). ).

If the detected knock intensity exceeds the knock intensity limit value and the judgment (208) is YES, the next ignition timing is retarded (210) and the process returns to the process (202).

If the detected knock intensity does not exceed the knock intensity limit value and the judgment (208) is NO, the previous knock detected by the knock sensor 106 before the ignition timing of the engine 2 is advanced. A knock intensity change rate is calculated from the intensity and the current knock intensity detected by knock sensor 106 after the ignition timing of engine 2 is advanced (212), and the next ignition timing is determined from this knock intensity change rate. The next knocking intensity generated when the lead angle is advanced is calculated and predicted (21).
4) By comparing the predicted next knock strength with the knock strength limit value, it is determined whether or not the predicted next knock strength exceeds the knock strength limit value (216).

If the next knock strength predicted by the above calculation is equal to or less than the knock strength limit value and the determination (216) is NO, the next ignition timing is advanced from the current ignition timing (218). , The process returns to (202), or the control is ended (220).

If the next knocking strength predicted by the above calculation exceeds the knocking strength limit value, the judgment (216) is YES.
In this case, the current ignition timing is held (222), and it is determined whether or not the operation region is the knock control region (22).
4).

If it is not the knock control area and the judgment (224) is NO, the process returns to the step (202). In the knock control area, if the determination (224) is YES, knock is detected by knock sensor 106 (226), and it is determined whether or not the detected knock strength exceeds the knock strength limit value (228). ).

If the detected knock intensity exceeds the knock intensity limit value and the determination (228) is YES, the next ignition timing is retarded (210), and the process returns to (202).

If the detected knock intensity does not exceed the knock intensity limit value and the judgment (228) is NO, whether or not a predetermined time has elapsed while the current ignition timing is held (222). Is determined (230).

If the predetermined time has not elapsed, it is determined (230)
Is NO, the process returns to step (222). If the predetermined time has elapsed and the determination (230) is YES, the next ignition timing is advanced from the current ignition timing (21).
8) Return to the process (202) or end the control (220).

As described above, the knocking control device 10
8 calculates the knock intensity change rate from the previous knock intensity detected by the knock sensor 106 before advance and the current knock intensity detected by the knock sensor 106 after advance, and calculates the next knock intensity from the knock intensity change rate. Next, the next knock intensity generated when the ignition timing is advanced is calculated and predicted, and the next next knock intensity is compared with the knock intensity limit value to advance and delay the next ignition timing. Control to hold the corner.

That is, the knocking control device 108
The knocking intensity generated when the next ignition timing is advanced is predicted, and the ignition timing in the vicinity of the limit value of the knocking occurrence region is appropriately controlled.

As shown in FIG. 2, the knocking control device 108, at the time of control A in the knock control region, when knocking below the knock intensity limit value occurs, at the next control time B as shown in FIG. The ignition timing is advanced by the set value. At the control time point B, by advancing the ignition timing, knocking stronger than the knock intensity at the control time point A occurs.

When the knocking strength at the control time point B is equal to or less than the knock strength limit value, as shown in FIG. The knock intensity change rate is calculated from the knock intensity after cornering, and the knock intensity generated when the ignition timing is advanced from the ignition timing at control point B at the next control point C is calculated from the knock intensity change rate. And predict.

If the knock intensity at the control point C predicted by this calculation is equal to or less than the knock intensity limit value, the ignition timing is advanced by a certain set value at the next control point C as shown in FIG. I do. At the control time point C, by advancing the ignition timing, knocking stronger than the knock strength at the control time point B occurs.

When the knock strength at the control time point C is equal to or less than the knock strength limit value, as shown in FIG.
The knock intensity change rate is calculated from the knock intensity before advancement at the time and the knock intensity after advance at the control time point C, and the knock intensity change rate is calculated from the knock intensity change rate at the next control time point D as compared with the ignition timing at the control time point C. The knock strength generated when the advance is advanced is calculated and predicted.

If the knock strength at the control time point D predicted by this calculation exceeds the knock strength limit value,
As shown in FIG. 5, the ignition timing at the current control point C is held at the next control point D. At the control time point D, since the ignition timing at the control time point C is held,
Similar to the control time point C, knocking equal to or less than the knock strength limit value occurs.

The knock strength at the control point E after the control point D is equal to or less than the knock strength limit value because the ignition timing at the control point C is maintained.

If the knock intensity exceeds the knock intensity limit value for some reason at the control time point F held at the ignition time point of the control time point C, the ignition timing is retarded as shown in FIG. . Thereafter, from the next control point G, the advance of the ignition timing based on the prediction of the knock strength is performed again.

When the knock intensity exceeds the knock intensity limit value, the ignition timing may be retarded to the zero level, or may be retarded by a certain set value. Also,
If the specified time has elapsed while holding the ignition timing,
The next ignition timing may be advanced. Alternatively, if a predetermined number of controls have been performed while maintaining the ignition timing, the next ignition timing may be advanced.

As described above, the knocking control device 10
8 calculates the knock intensity change rate from the previous knock intensity detected by the knock sensor 106 before advance and the current knock intensity detected by the knock sensor 106 after advance, and calculates the next knock intensity from the knock intensity change rate. By calculating the next knock strength that occurs when the ignition timing is advanced, the next knock strength is compared with the knock strength limit value, and the next ignition timing is controlled, so that the next ignition strength is controlled. I can judge the possibility accurately,
The processing of the advance angle and the retard angle can be appropriately performed, and the ignition timing can be controlled to reflect the current state of the engine 2.

Therefore, the knocking control device 108
Is capable of accurately determining the possibility of advancement and performing appropriate advance and retard processing, thereby reducing unnecessary advance and retard processing and reducing unnecessary advance. Engine 2 by
Damage to the engine 2, the torque fluctuation of the engine 2 can be reduced, and the ignition timing can be controlled to reflect the current state of the engine 2. Thus, the ignition timing can be controlled, and the ignition timing can be controlled in response to aging or the like.

When the calculated next knocking intensity exceeds the knocking intensity limit value, knocking control device 108 controls so as to maintain the current ignition timing, so that the output near the knocking intensity limit value is output. Is advanced for a long time, the output of the engine 2 can be improved, and when a predetermined time has elapsed after controlling to keep the calculated next ignition timing at the current ignition timing, By controlling the next ignition timing to be more advanced than the current ignition timing, it is possible to further improve the output.

Further, when the calculated next knocking intensity is equal to or smaller than the knocking intensity limit value, knocking control device 108 controls the next ignition timing to be advanced from the current ignition timing, thereby controlling the engine. The output can be improved without causing damage to the knock sensor 10.
When the knock intensity detected by the engine 6 exceeds the knock intensity limit value, the engine 2 can be prevented from being damaged by controlling the next ignition timing to be retarded.

The knocking control device 108
The ignition timing is controlled so as not to exceed the knock intensity limit value by predicting the next knock intensity from the change rate of the knock intensity between the previous time and this time, and is also applied to the control of other engines 2. be able to. For example, the control of the knocking control device 108 controls the supercharging pressure so that the supercharging pressure does not exceed a target supercharging pressure which is a limit value, or controls the air-fuel ratio so as not to exceed the target air-fuel ratio. The present invention can be applied to a control device such as an air-fuel ratio control device that performs feedback control with a certain target value.

The knocking control device 108 includes:
The next knock strength was predicted from the change rate of the knock strength between the previous time and this time, but the prediction of the next knock strength is performed by taking into account the engine load such as the throttle opening, etc. And the output of the engine 2 can be improved.

[0053]

As described above, the knocking control device according to the present invention can accurately determine the possibility of the advance angle, and can appropriately perform the advance and retard processing, thereby providing an unnecessary advance angle. And retard processing can be reduced, engine damage due to unnecessary advance can be eliminated, engine torque fluctuation can be reduced, and the ignition timing is controlled to reflect the current state of the engine. With this configuration, the ignition timing can be controlled in consideration of the influence of the warm-up state and the like, and the ignition timing can be controlled in response to aging and the like.

[Brief description of the drawings]

FIG. 1 is a flowchart of control of a knocking control device according to an embodiment of the present invention.

FIG. 2 is a timing chart of knock intensity and ignition timing when knocking occurs.

FIG. 3 is a timing chart of knock intensity and ignition timing at the time of advance after knocking has occurred.

FIG. 4 is a timing chart of knock strength and ignition timing at the time of advancing after the occurrence of the next knocking.

FIG. 5 is a timing chart of knock strength and ignition timing in a state where ignition timing is held.

FIG. 6 is a timing chart of the knock intensity and the ignition timing when the knock intensity exceeds the knock intensity limit value.

FIG. 7 is a schematic configuration diagram of a knocking control device.

[Explanation of symbols]

 2 Engine 12 Combustion chamber 32 Intake passage 42 Exhaust passage 44 Supercharger 58 Ignition coil 66 Fuel injection valve 94 Crank angle sensor 96 Water temperature sensor 98 Throttle sensor 100 Intake temperature sensor 102 Intake pressure sensor 104 O2 sensor 106 Knock sensor 108 Knock control device 110 control means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G022 AA05 DA01 DA02 DA03 DA07 EA02 EA07 FA01 FA03 GA01 GA05 GA07 GA08 GA09 GA11 GA13 3G084 BA17 DA11 DA38 EA04 EA11 FA02 FA10 FA11 FA20 FA25 FA33 FA38

Claims (5)

[Claims] 1. A knock sensor for detecting knocking of an engine is provided, and before the ignition timing of the engine is advanced, the knock intensity detected by the knock sensor and the ignition timing of the engine are advanced. A knock intensity change rate is calculated from the current knock intensity detected by the knock sensor, and a next knock intensity generated when the ignition timing is advanced next time is calculated from the knock intensity change rate, A knocking control device comprising a control means for comparing the next knocking intensity with a knocking intensity limit value and controlling the next ignition timing. 2. The control device according to claim 1, wherein the control means controls to maintain the current ignition timing when the calculated next knock intensity exceeds the knock intensity limit value. Knocking control device. 3. When a predetermined period of time has elapsed after controlling to maintain the calculated next ignition timing at the current ignition timing, the control means advances the next ignition timing by more than the current ignition timing. The knocking control device according to claim 2, wherein the knocking control device performs control. 4. The control means controls the next ignition timing to be more advanced than the current ignition timing when the calculated next knock intensity is equal to or less than the knock intensity limit value. The knocking control device according to claim 1. 5. The control means, when the knock intensity detected by the knock sensor exceeds a knock intensity limit value,
2. The knocking control device according to claim 1, wherein control is performed to retard the next ignition timing.