KR100962198B1 - System for noise control a turbo charger for diesel engine and method thereof - Google Patents

Abstract

It is to reduce the BPF (Blade Passing Frequency) noise generated by the turbocharger when tipping out of the accelerator pedal during acceleration of a diesel engine.

The present invention is a process for detecting the tip-out of the accelerator pedal in the driving state, the process of determining the virtual fuel amount according to the engine speed when the tip-out is detected, determining the delay time and vane duty to inject the virtual fuel amount injection control Process.

Diesel Engine, Turbocharger, BPF Noise, Virtual Fuel Level, Tip Out

Description

Turbocharger Noise Control System and Method in Diesel Engines {SYSTEM FOR NOISE CONTROL A TURBO CHARGER FOR DIESEL ENGINE AND METHOD THEREOF}

The present invention relates to a diesel engine, and more particularly, to turbocharger noise in a diesel engine that reduces the BPF (Blade Passing Frequency) noise generated in the turbocharger when tipping out of the accelerator pedal in a driving state. A control apparatus and method are provided.

In general, turbochargers are applied to diesel engines for improved power, fuel economy, improved land performance, and reduced soot.

The turbocharger rotates the turbine wheel while the exhaust gas flows inside the turbine housing, and the compressor wheel connected to the same axis rotates at high speed simultaneously. Compresses a large amount of air coming through and sends it to the combustion chamber of the engine to perform combustion with high filling efficiency through supercharging.

As such, the BPF noise of 5 to 20Khz band is generated due to the pressure flow and unstable air flow generated by each wheel in the process of compressing the air flowing through the intake manifold into the compressor wheel. Is generated (high-frequency Whistle noise).

BPF noise increases as the turbulence of the incoming air increases, and the noise increases due to the large amount of vortex flow of recirculated air.

As a countermeasure for reducing BPF noise, it can be divided into a source side and a path side on a shear path.

Measures to reduce BPF noise on the source side include reducing the turbulence of the air inlet, expanding the straight section of the flow path entering the inlet of the turbocharger, removing the flow separation of the recirculated air, and vanes. And a single part design change method for improving the flow characteristics such as the shape of the wheel and the shape of the turbine wheel tip.

In addition, as a countermeasure for reducing BPF noise in the path side of the shear path, a method of reducing solid sound through insulation of the turbocharger and the structure and increasing the stiffness reinforcement and transmission loss of the structure combined with the turbocharger and the turbocharger to increase the transmission sound There is provided a method for reducing the temperature.

In order to reduce the BPF noise generated during acceleration and deceleration of the turbocharger, a hardware method is mainly used as mentioned above.

Among them, as a representative method, a method of improving the flow characteristics introduced by changing the shape of the turbine wheel tip is mainly used.

That is, the BPF noise is reduced by changing the turbine wheel tip shape from the existing straight form (Straight Type (No Sweep)) to the tip type by turning the tip portion into a sweep type.

In addition, by increasing the number of wheels to reduce the load on each wheel relatively, as well as the relatively small ripple (ripple) displacement due to the narrow intervals to reduce the noise.

This conventional BPF noise reduction method is closely related to the behavior (fluid characteristics) of the vane (VPF) noise, the problem that the noise reduction effect is inadequate for the cost by approaching only in hardware without excluding this There is this.

In addition, the hardware noise replacement method has a problem that acts as a burden on the consumer to increase the manufacturing cost of the turbocharger.

And, in order to apply the improved turbocharger has to go through a durability test, there is a problem that the development time takes a long time.

In addition, there is a problem in that a quality deviation occurs according to each of the turbochargers separately, the quality homogeneity of the BPF noise reduction is inferior.

The present invention has been invented to solve the above problems, the object of which is to set the virtual fuel amount according to the engine speed when tipping out of the accelerator pedal, and to control the amount of fuel reduced by the set delay time in the turbocharger Freeing the vane's behavior reduces the BPF noise generated by the blades and air flow.

Turbocharger noise control device in a diesel engine according to a feature of the present invention for achieving the above object,

An engine speed detector for detecting engine speed from a phase change of the crankshaft or camshaft;

An accelerator pedal detector detecting a displacement of the accelerator pedal;

A memory unit configured to set a virtual fuel amount according to an engine speed as a table;

A control unit configured to determine a virtual fuel amount according to the engine speed from the table set in the memory unit, determine a delay time and a vane angle change amount for the injection of the virtual fuel amount, and control the injection when the accelerator pedal tip-out is detected;

And an injector for executing fuel injection under the control of the controller.

In addition, the turbocharger noise control method in the diesel engine according to a feature of the present invention,

Detecting a tip-out of the accelerator pedal in the driving state;

Determining a virtual fuel amount according to the engine speed when the tip out is detected;

And controlling injection by determining a delay time and a vane angle change amount for injecting the virtual fuel amount.

By the above-described configuration, the present invention can be expected to have an effect of minimizing the air separation between the air and the blade by minimizing the vane angle in the closed loop section by applying a virtual fuel amount to minimize the occurrence of BPF noise.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

Since the present invention can be implemented in various different forms, the present invention is not limited to the exemplary embodiments described herein, and parts not related to the description are omitted in the drawings in order to clearly describe the present invention.

1 is a view showing the configuration of a turbocharger noise reduction device in a diesel engine according to an embodiment of the present invention.

The present invention includes an engine speed detector 10, an accelerator pedal detector 20, a controller 30, a memory 40, and an injection device 50.

The engine speed detector 10 detects the current engine speed from a phase change of the crankshaft or camshaft and provides the controller 30 with information about it.

The accelerator pedal detection unit 20 detects the displacement of the accelerator pedal operated by the driver and provides information about the accelerator pedal to the controller 30.

When the tip-out of the accelerator pedal is detected in the driving state, the controller 30 determines the virtual fuel amount according to the current engine speed from the table set in the memory unit 40, and the delay time for the injection of the determined virtual fuel amount and The fuel injection is controlled by determining the vane duty that adjusts the vane angle change amount (vane opening amount).

The memory unit 40 sets a virtual fuel amount in a table according to the current engine speed.

The injector 50 is operated under the control of the controller 30 to inject the fuel amount determined according to the operating conditions to the corresponding combustion chamber.

The operation of the present invention including the function as described above will be described with reference to FIG.

When the vehicle equipped with the diesel engine is driven (S101), the engine speed detector 10 detects the current engine speed and applies it to the controller 30 (S102). The accelerator pedal detector 20 is an accelerator pedal by the driver. Is detected and applied to the control unit 30 (S103).

At this time, the controller 30 analyzes the displacement of the accelerator pedal to determine whether a tip-out is detected by the driver's foot off the accelerator pedal (S104).

If the tip-out is not detected in the determination of S104, the process returns to the process of S102. If the tip-out is detected, the virtual fuel amount according to the current engine speed is determined from the table set in the memory unit 40 (S105).

Then, the delay time and vane duty for maintaining the injection of the virtual fuel amount are determined (S106).

The virtual fuel amount and the delay time according to the engine speed are set, for example, as shown in Table 1 below.

RPM (→)
Fuel amount (↓) 0 1000 1500 2000 2500 3000 4500 0 0 1.5 0.5 0.5 0.5 0.5 0.5 4 0 1.5 0.5 0.5 0.5 0.5 0.5 12 0 1.5 0.5 0.5 0.5 0.5 0.5 20 0 1.5 0.5 0.5 0.5 0.5 0.5 28 0 1.5 0.5 0.5 0.5 0.5 0.5 36 0 1.5 0.5 0.5 0.5 0.5 0.5 40 0 1.5 0.3 0.3 0.3 0.5 0.5 48 0 1.5 0.3 0.3 0.3 0.5 0.5 62 0 1.5 0.2 0.2 0.2 0.5 0.5 70 0 1.5 0.2 0.2 0.2 0.5 0.5

As can be seen in Table 1, the delay time is relatively small in the 1500 to 2500 RPM section in which the vane duty changes abruptly with respect to the same fuel amount.

Thereafter, by applying the delay time and vane duty determined as described above through the injector 50 to inject the virtual fuel amount determined according to the tip out, the angle of the vane is gradually reduced in the closed loop section according to the tip out of the accelerator pedal. By minimizing the separation between the air and the vane blades to reduce the BPF noise (S107).

Conventionally, the injection fuel amount for controlling the vanes at the tip out is appropriate to the actual fuel amount, so that the vanes are unconditionally opened according to the tip out, and thus BPF noise is seriously generated.

However, in the present invention, by setting the virtual fuel amount at the tip out to secure the degree of freedom in the vane behavior, the BPF noise generated by the blade and the air flow is minimized.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It is included in the scope of rights.

1 is a view showing a schematic configuration of a turbocharger noise control device in a diesel engine according to an embodiment of the present invention.

2 is a flowchart of the noise reduction control of the turbocharger in the diesel engine according to the embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: engine speed detection unit 20: accelerator pedal detection unit

30 control unit 40 memory unit

50: injector

Claims (3)

An engine speed detector for detecting engine speed from a phase change of the crankshaft or camshaft; An accelerator pedal detector detecting a displacement of the accelerator pedal; A memory unit configured to set a virtual fuel amount according to an engine speed as a table; A controller configured to determine a virtual fuel amount according to the engine speed from a table set in the memory unit, determine a delay time and vane duty for injection of the virtual fuel amount, and control injection by using an accelerator pedal tip-out; Turbocharger noise control device in a diesel engine comprising an injection device for performing a fuel injection under the control of the controller. delete Detecting a tip-out of the accelerator pedal in the driving state; Determining a virtual fuel amount according to the engine speed when the tip out is detected; Turbocharger noise control method in a diesel engine comprising the step of controlling the injection by determining the delay time and vane duty for injecting the virtual fuel amount.

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