Intake system of engine

An intake system of an engine may include an intake line supplying an engine with air, an exhaust line that exhaust gas combusted in the cylinder is exhausted, a housing disposed on the intake line and a compressor is disposed therein, the compressor is operated by a turbine disposed on an exhaust line, a recirculation line that recirculates the air from the intake line of a downstream side of the compressor to the intake line of an upstream side of the compressor, and an anti surge valve disposed on the recirculation line to open/close the recirculation line, wherein a length of a first section (l) that is straight from the anti surge valve is longer than two times the outlet diameter (d) of the anti surge valve in the recirculation line that is formed from the anti surge valve to an upstream side of the compressor.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent Application Number 10-2010-0113837 filed Nov. 16, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates a turbo-charger having an anti-surge valve circulating reversed air to an upstream side of a compressor when a throttle valve is closed.

2. Description of Related Art

A gasoline engine uses a throttle valve to control intake air, and the intake air can flow backwards at a point of a tip-out (a behavior of taking a driver's foot off the accelerator).

Particularly, in a case that a turbo-charger is mounted therein, the reversed intake air collides with a blade of a compressor to generate noise and vibration and to deteriorate the durability thereof.

A bypass line is formed between an upstream side and a downstream side of the compressor, and an anti-surge valve is disposed on the bypass line so as to resolve the above problem.

The anti-surge valve opens the bypass line to re-circulate the air between the throttle valve and the compressor so as to reduce the noise and vibration generated from the blade of the compressor.

FIG. 1is a schematic diagram of an intake system of an engine. Referring to the drawing, the intake system of the engine includes a intake line100, a compressor110a, an anti surge valve120, an intercooler pipe130, an intercooler140, a throttle valve145, an intake manifold150, and an exhaust line160, and a turbine110b.

Meanwhile, a turbulent flow is formed in air that re-circulates to the intake line as an inlet of the compressor through the anti surge valve by a tip-out behavior and the air collides with the blade of the compressor that rotates at a high speed to generate high pitched tone noise by pulsation.

Further, during the tip-out behavior, the air does not flow uniformly the anti-surge valve such that flow separation phenomenon is formed and noise is formed by a turbulent flow.

SUMMARY OF INVENTION

Various aspects of the present invention provide for a turbo system having an anti surge valve that is configured to reduce noise generated when air between a compressor and a throttle valve is circulated to an upstream side of the compressor and an intake system of an engine has the turbo system.

One aspect of the present invention is directed to an intake system of an engine that may include an intake line that is configured to supply cylinder of an engine with air, an exhaust line that exhaust gas combusted in the cylinder is exhausted, a housing disposed on the intake line and a compressor is disposed therein, the compressor is operated by a turbine disposed on an exhaust line, a recirculation line that recirculates the air from the intake line of a downstream side of the compressor to the intake line of an upstream side of the compressor, and an anti surge valve disposed on the recirculation line to open/close the recirculation line, wherein a length of a first section (l) that is straight from the anti surge valve is longer than two times the outlet diameter (d) of the anti surge valve in the recirculation line that is formed from the anti surge valve to an upstream side of the compressor.

A distance (L) from the intake line that is connected to the recirculation line to the inlet of the housing is longer than three times the inlet diameter (D) of the housing that the compressor is disposed therein.

The recirculation line may include a first recirculation line that is diverged from the intake line of the downstream side of the compressor to be connected to the anti surge valve, and a second recirculation line that is formed from the anti surge valve to join the intake line of the upstream side of the compressor, wherein an intercooler is disposed at a downstream side of the diverged point that is diverged to the first recirculation line.

A throttle valve may be disposed at a downstream side of the intercooler to adjust the flowing amount of the air.

The first recirculation line may be diverged from an intercooler pipe that is formed between the compressor and the intercooler.

As stated above, while the intake air circulates the anti surge valve during a tip-out or acceleration period, the turbulent flow is decreased and the flow becomes smooth such that the noise is decreased and the emotional quality is improved in the intake system of the engine.

DETAILED DESCRIPTION

FIG. 2is a schematic diagram of an intake system of an engine according to various embodiments of the present invention.

Referring toFIG. 2, the intake system of an engine includes an intake line100and an exhaust line160.

A compressor housing200that a compressor110ais built therein, an intercooler pipe130, an intercooler140, a throttle valve145, and an intake manifold150are sequentially disposed on the intake line100, and a turbine110bis disposed on the exhaust line160.

Further, the turbocharger110includes a turbine110band a compressor110a, wherein the compressor110ais configured to by rotated by the turbine110b.

Intake air flow the intake line100through the compressor110a, the intercooler pipe130, the intercooler140, the throttle valve145, and the intake manifold150to be supplied into combustion chambers of the engine, and the exhaust gas combusted in the combustion chamber is exhausted through the turbine110bof the exhaust line160.

When the throttle valve145is closed in the instant of taking driver's foot off the accelerator pedal (Tip out), a recirculation line is formed so as to release a pressure formed between the compressor110aand the throttle valve145, and an anti surge valve120is mounted on the recirculation line210.

The anti surge valve120opens the recirculation line210in a predetermined driving condition to re-circulate the air of the downstream side of the compressor110ato the upstream side thereof.

The recirculation line210includes a first recirculation line210aand a second recirculation line210b, the first recirculation line210ais diverged from the intercooler pipe130to be connected to one side of the anti surge valve120, and one end of the second recirculation line210bis connected to the anti surge valve120and the other end thereof joins the intake line of the upstream side of the compressor110a.

An inlet of the compressor housing200has a diameter D of a predetermined length and a distance L from a point that the intake line100joins the second recirculation line210b, wherein the distance L is 3 times longer than the diameter D.

Accordingly, air flowing into the blade of the compressor110abecomes uniform such that turbulent flow is decreased and the noise generated thereby is decreased.

In the second recirculation line210bthat is connected to the anti surge valve120, the length of a first section (I) that is straight from the anti surge valve120is 2 times longer than the outlet diameter d of anti surge valve.

Accordingly, the air flow passing the anti surge valve120become uniform such that the maximum flow velocity and the noise are decreased.

FIG. 3is a table showing effects of an intake system of an engine according to various embodiments of the present invention.

Referring toFIG. 3, compared with the conventional art, this invention increases the flow amount by about 6% and decreases the maximum speed by about 19%. Further, there are effects that the near field noise is decreased by 5 to 10 dB and the interior noise is decreased by 2 to 3 dB. The near field noise can be detected by such as a micro phone at a position that is spaced apart by 10 centimeters from the noise source.

As described above, the above invention decreases the noise with a simple structure such that the development time is saved, the noise of the air flowing during acceleration or deceleration is decreased such that the emotional quality is improved, and the noise absorption components are saved such that the production cost is reduced.