JPS60256527A - Knocking control device - Google Patents

Abstract

PURPOSE:To surely restrain the occurrence of knocking, by opening a waist gate valve upon occurrence of knocking, and by discharging fuel from a fuel injection pump into an intake-air system when the occurrecce of knocking may not be completely restrained even if the opening degree of the waist gate valve is set at a set opening degree. CONSTITUTION:An electomagnetic fuel injection pump 17 is disposed instead of a mechanical accelerator pump in the fast system 6a of a carburettor 6 upstream of the venturi section. Further, there is provided a waist gate valve 15 for opening and closing bypass passage bypassing a turbine 14 in a supercharger 12. When a microcomputer 33 which receives an output signal (e) from a knock sensor 41, etc. detects the occurrence of knocking, it delivers at first a signal (c) instructing the opening of the waist gate valve 15 to a waist gate controller 16. Then, when the occurrence of knocking may not be restrained even if the above- mentioned valve 15 is opened to a set opening degree having an intermediate value, a signal (d) instructing the discharge of fuel is delivered to the fuel injection pump 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a knocking control device mainly applied to an automobile engine.

[Prior Art] Many modern automobile engines have been equipped with a supercharger such as an exhaust turbocharger or have increased compression ratios to improve efficiency. This makes knocking more likely to occur. Knocking is air column vibration caused by self-ignition of end gas in the combustion chamber, and it not only produces unpleasant sounds and vibrations, but may also be accompanied by a reduction in output. Moreover, excessive knocking may occur and cause damage to the spark plug, valve, or piston, resulting in a significant reduction in the durability of the engine. Therefore, this type of twin engine is generally equipped with a knocking control device to suppress the occurrence of harmful knocking.

As a prior art related to this type of knocking control device, there is one disclosed in Japanese Patent Laid-Open No. 1384-35-1983. In other words, this product has a knock sensor installed in the engine body to detect knocking.
When the occurrence of knocking is detected by this knock sensor, the air-fuel ratio is corrected toward the lower side. Note that conventional air-fuel ratio control is performed by changing the opening degree of the air bleed passage or the main jet.

[Problems to be solved by the invention] However, even if knocking is suppressed only by supplementing the air-fuel ratio to the rich side, fuel tends to be wasted and fuel economy is reduced. The problem is that it gets worse. Also, correct the air-fuel ratio by adjusting the opening of the ablation passage and main engine from 0 to 3 from ear-6o.
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A special actuator is required to adjust the degree. Therefore, there is a problem that the number of parts increases, the structure becomes complicated, and the cost increases. Furthermore, with this type of air-fuel ratio control, there is a problem that a time delay tends to occur in increasing the amount of fuel, making it difficult to perform accurate control with high responsiveness.

[Means for Solving the Problem] In order to solve the problem, the present invention suppresses the occurrence of knocking by controlling the opening of the waste gate valve preferentially in a partial area, and by this control, This system uses an electromagnetic fuel injection pump, which is provided as an alternative to the mechanical acceleration pump, to change the air-fuel ratio only when knocking cannot be suppressed. That is, in the present invention, when the knock sensor detects the occurrence of non-king, the control means outputs a signal indicating that the wastegate/loop should be opened, and the wastegate valve is opened to a preset partial opening degree. The present invention is characterized in that it is configured to output a signal to the effect that fuel should be discharged toward the fuel injection pumps j and j' when the occurrence of knocking cannot be suppressed completely.

[Effect] Therefore, in case of non-king or occurrence.

First, the wastegate/help opens slightly, lowering the boost pressure and suppressing the occurrence of knocking. If knocking occurs that cannot be suppressed even if the wastegate valve is opened to the set opening degree, then fuel will be discharged from the fuel injection pump to the taste system path. As a result, the air-fuel ratio is instantaneously corrected to the rich side5, and noaking is quickly suppressed.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a system explanatory diagram schematically showing an automobile gasoline engine. In the figure, 1 is the engine body, 2 is an intake system path, and 3 is an exhaust system path. The intake system passage 2 has its starting end opened to the atmosphere via an air cleaner (not shown), and its terminal end connected to the combustion chamber 5 of the engine body 1 via an intake valve 4.
The vaporizer 6 is interposed in the middle of the communication. The carburetor 6 has a first system 6a and a secondary system 6b.
The throttle valve 7 of the first system 6a opens and closes depending on the amount of depression of the accelerator pedal, while
The throttle valve 8 of the secondary system 6b is connected to the intake system path 2.
It is connected to a diaphragm mechanism 9 that is activated by internal pressure, and opens mainly in a high load range. The exhaust system path 3 has a starting end communicating with the combustion chamber 5 via an exhaust valve 11 and a terminal end opening to the atmosphere through a muffler (not shown), etc., and this exhaust system path 3 and the intake air An exhaust turbocharger 12 is provided between the system 2 and the system 2. The exhaust turbocharger 12 is connected to the intake system path 2.
A compressor section 13 is provided upstream of the carburetor 6, and a turbine section 14 is provided in the middle of the exhaust system path 3 and rotates by exhaust energy to drive the compressor section 13. A waste gate/help 15 is installed in parallel to the turbine section 14. The wastegate valve 15 is for bypassing the exhaust gas and decelerating the turbine section 4, and is attached to a wastegate controller 16 that operates in response to an electrical signal input from a boost pressure sensor (not shown) or the like. It opens and closes under pressure.

Note that the carburetor 6 does not have a mechanical acceleration pump, but is equipped with an electromagnetic fuel injection pump 17 as an alternative element. As shown in FIG. 2, the fuel injection pump 17 houses a piston 21 in a cylinder 19 that forms a pump chamber 18, and moves the piston 21 forward and backward by the urging force of a spring 22 and the electromagnetic attraction force of a solenoid 23. It is constructed so that it can perform the pump function. The pump 17 also includes an inlet 24 and an outlet 25 that communicate with the pump chamber 18, respectively.
is communicated with the float chamber 28 of the inflator 6 via an inlet passage 27 having a reverse valve 26, and the outlet 2
5 is opened into an intake passage 32 of the carburetor 6 via an outlet passage 31 having a reverse valve 29. and,
This fuel injection pump 17 is controlled by a microcomputer 33. microcomputer 3
3 is a central processing unit 34 and a memory 35;
A detection signal from an opening detector 38 that detects the open position of the throttle valve 7 is input to the interface 36 . The memory 35 of this microcomputer 33 contains the following programs. That is, the opening degree detector 38
The acceleration in the opening direction of the throttle valve 7 is calculated by sequentially reading the detection signal a from the throttle valve 7 and second-order differentiating the read position information of the throttle valve 7 with respect to time. Then, by comparing the calculated value with a set value, if it is determined that the throttle valve 7 is opened at an acceleration above a certain level, a signal is sent to the effect that acceleration fuel should be discharged toward the fuel injection pump 17. Output. Specifically, pulse voltage 11 (pressure) is applied a predetermined number of times to the solenoid 23 of the fuel injection pump door.

An engine having such a configuration is provided with a knocking control device according to the present invention. This knocking control device includes a knock sensor 41 that detects knocking, and a signal from the knock sensor 41 that instructs the wastegate controller 16 to open the wastegate valve 15 when the occurrence of knocking is detected. A signal d indicating that fuel should be discharged toward the fuel injection pump 17 when the occurrence of knocking cannot be suppressed even if the waste gate valve 15 is opened to an intermediate setting opening degree. and a control means for outputting. In this embodiment, the microcomputer 33 plays the role of the control means. To be more specific, the knock sensor 41 converts the vibration of the cylinder block 42 excited by air column vibration due to knocking into an electric signal e using a piezoelectric element, and the electric signal e is transmitted to the micro computer 33
The information is input to the interface 36 of the computer. This microcomputer 33 contains, in addition to the programs mentioned above.

It contains the following programs and data.

That is, the intensity of knocking and the amount stored in the waste gate pulse 5 necessary to suppress the knocking. Then, a knocking detection signal e is sent from the knocking sensor 41.
is applied, the wastegate valve opening degree corresponding to the intensity of knocking is selectively extracted from the red memory 35, and an opening command signal C corresponding to the opening degree is outputted to the wastegate controller 16. It is.

The wastegate controller 16 carries out duty control on the wastegate valve 15 to ensure a substantial opening corresponding to the opening command signal C, thereby bypassing the exhaust of the required moisture. Further, the relationship between the knocking intensity when the waste gate valve 15 is controlled to open and the optimal fuel increase value for suppressing the knocking is determined through experiments, and the data is stored in the memory 35. And the waste gate valve 1
When the knocking sensor 41 continues to supply the signal e even when the knocking sensor 5 is opened to a predetermined opening between fully closed and fully open, a fuel increase value corresponding to the knocking intensity is stored in the memory 35. The pulse signals d corresponding to the fuel increase value are output from the interface 37 to the fuel injection pump 17.

With such a configuration, when the throttle valve 7 is opened with a constant acceleration, a number of pulse voltages corresponding to the degree of acceleration are applied to the solenoid 23 of the fuel injection pump 17, and the number of pulses is The piston 21 reciprocates a number of times corresponding to , and the necessary fuel is discharged into the intake passage 32 of the carburetor 6. As a result, the lag in fuel from the main jet (not shown) is compensated for and proper acceleration is achieved.

Also, when knocking occurs, the knock sensor
Then, a signal d to that effect is given to Peter 33. As a result, the microcomputer 33 outputs an opening command signal C to the wastegate controller 16 in accordance with the degree of knocking. As a result, the wastegate valve 15 is opened to the actual opening degree corresponding to No. 48C, a part of the exhaust gas is bypassed, and the turbine section 14 is decelerated. Therefore, the boost pressure is reduced and the occurrence of knocking is suppressed. In addition,
If the occurrence of knocking cannot be suppressed even if the waste gate valve 15 is opened to the set opening degree, the microcomputer 33 further injects fuel into the fuel injection pump 17 according to the degree of knocking. A signal d indicating that fuel should be discharged is output, and the fuel injection pump 1
7 operates a number of times corresponding to the signal d to discharge fuel to the intake road 32. Therefore, the air-fuel ratio is instantaneously corrected to the rich side, and knocking is quickly suppressed. By the way, even if such air-fuel ratio control is added, knocking cannot be brought under control. , □ 00. Oh, wa4
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5 Tsuji, Tatami, etc. were opened and finally it was fully opened.

In this way, non-knocking can be suppressed, and in principle, knocking is suppressed by controlling the opening of the waste gate valve 15. That is, the air-fuel ratio is controlled only when knocking cannot be suppressed even if the wastegate valve 15 is opened to the set opening degree. Therefore, it is possible to minimize the inconvenience that fuel is wasted to suppress knocking, and it is possible to significantly improve fuel economy compared to a system based on air-fuel ratio control.

Furthermore, since the air-fuel ratio is controlled after the wastegate valve 15 is opened to the partially set opening, the engine output will be significantly reduced, unlike when knocking is suppressed using only the wastegate valve. No inconvenience will occur.

In addition, the wastegate valve 15 is controlled preferentially, and the electromagnetic fuel injection pump 33, which is provided as an alternative element to the acceleration pump, is used to correct the air-fuel ratio when knocking occurs. Compared to systems that correct the air-fuel ratio by adjusting the air bleed or main jet opening, this system allows for more responsive control, and can quickly and accurately suppress noking. Also,
In this way, when the functions of the existing waste gate valve 15 and acceleration fuel injection pump 17 are utilized, no special actuator, valve, etc. for knock control are required. In particular, this embodiment can be implemented simply by adding the knock sensor 41 and expanding the program in the microcomputer 33. Therefore, it has the advantage that the number of parts is small, the structure is simple, and it can be easily implemented.

In the above embodiment, a case is explained in which the microcomputer for accelerating fuel increase control also plays a role as a control means for knocking control.
The present invention is not necessarily limited to this, and for example, control means for increasing acceleration fuel and control means for controlling knocking may be provided separately.

Further, the method of determining the fuel discharge amount and the opening degree of the waste gate valve depending on the degree of knocking is not limited to the map method as described above. For example, a formula showing the relationship between the degree of knowing and the amount of fuel discharged or the opening of the wastegate valve may be stored in memory, and the formula may be used to calculate the optimal amount of fuel discharged or the opening of the wastegate valve each time. You can also do this.

[Effects of the Invention] Since the present invention has the above configuration, it has a small number of parts, a simple structure, and is easy to implement.Moreover, it has high responsiveness and can quickly and accurately suppress knocking. ,
Furthermore, it is possible to provide a knocking control device that can prevent wasteful use of fuel and ensure high fuel economy.

[Brief explanation of the drawing]

! Figure 1''*Invention 0-1 Example 1'yZ5-1=,
The R-light view and FIG. 2 are schematic cross-sectional views of the fuel injection pump in the same embodiment. llI...Engine body 2--Intake system path 3--Exhaust system path 5--Combustion chamber 6-φΦ carburetor 12...Exhaust turbocharger 15--Kuma waste gate valve 16@@-Waste gate Controller 17... Fuel injection pump 33, φ, control means (microcomputer) agent
Patent Attorney Red Line - Hiroshi 1. (Me

Claims (1)

[Claims] A carburetor that eliminates the mechanical accelerator pump, and an electromagnetic fuel injection pump that replaces the accelerator pump.
The exhaust turbocharger includes a compressor section arranged upstream of the carburetor and a wastegate valve arranged in parallel in a turbine section that drives the compressor section, and a wastegate controller that opens and closes the wastegate valve. This knocking control device for an engine includes a knock sensor that detects knocking, and when the knocking sensor detects the occurrence of knocking, the knocking control device should first open the wastegate/help to the wastegate controller. In addition to outputting a signal indicating that fuel should be discharged to the fuel injection pump when the occurrence of knocking cannot be suppressed even if the waste gate valve is opened to an intermediate setting opening degree, A knocking control device comprising a control means for outputting an output.