Abstract:
A turbocharger having an anti-surge valve may include a compressor that may be disposed at an intake line to compress intake air, and the anti-surge valve that selectively fluid-connects the downstream and the upstream of the compressor to circulate the intake air from the downstream to the upstream of the intake line, wherein a passage communicating with the downstream of the intake line may be formed in the anti-surge valve and the intake air flowing through the passage may be supplied to an edge portion outside a rotation center of a blade of the compressor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to Korean Patent Application No. 10-2010-0094716 filed in the Korean Intellectual Property Office on Sep. 29, 2010, the entire contents of which is incorporated herein for all purposes by this reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a turbo device having an anti-surge valve. More particularly, the present invention relates to a turbocharger having an anti-surge valve circulating reversed air to an upstream side of a compressor when a throttle valve is closed. 
         [0004]    2. Description of Related Art 
         [0005]    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&#39;s foot off the accelerator). 
         [0006]    Particularly, in a case that a turbocharger 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. 
         [0007]    So as to resolve the above problem, a bypass line is formed between an upstream side and a downstream side, and an anti-surge valve is disposed on the bypass line. 
         [0008]    So as to reduce the noise and vibration generated from the blade of the compressor, the anti-surge valve opens the bypass line to re-circulate the air between the throttle valve and the compressor. 
         [0009]    Meanwhile, the air re-circulating to the compressor collides with the blade of the compressor, which rotates at a high speed. 
         [0010]    The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    Various aspects of the present invention are directed to provide a turbocharger having an anti-surge valve having advantages of reducing noise generated by circulating air between a compressor of a turbocharger and a throttle valve. 
         [0012]    In aspect of the present invention, the turbocharger having an anti-surge valve, may include a compressor that may be disposed at an intake line to compress intake air, and the anti-surge valve that selectively fluid-connects the downstream and the upstream of the compressor to circulate the intake air from the downstream to the upstream of the intake line, wherein a passage communicating with the downstream of the intake line may be formed in the anti-surge valve and the intake air flowing through the passage may be supplied to an edge portion outside a rotation center of a blade of the compressor. 
         [0013]    An average flowing velocity line of the intake air that may be exhausted from the passage of the anti-surge valve to flow into the blade of the compressor may be formed towards a rotating direction of the blade, wherein an inlet opening of the passage may be larger than an outlet opening thereof to form a cone shape and wherein the outlet opening of the passage may be aligned such that the average flowing velocity line may be tangential to a rotation trace of the blade. 
         [0014]    The average flowing velocity line of the intake air that may be exhausted from the passage of the anti-surge valve to flow into the blade of the compressor may be formed, and a hypothetical line that connects an inlet center of the passage to the rotation center of the blade forms a predetermined angle with the average flowing velocity line, wherein an inlet opening of the passage may be larger than an outlet opening thereof to form a cone shape, and wherein the outlet opening of the passage may be aligned such that the average flowing velocity line may be tangential to a rotation trace of the blade, and wherein the predetermined angle that may be formed between the hypothetical line and the average flowing velocity line may be at least 15 degrees. 
         [0015]    The anti-surge valve may include an opening/closing unit that controls the intake air flowing into the passage, and wherein a lift height of the opening/closing unit may be equal to or larger than an inlet diameter of the passage, wherein one side surface of a valve plate contacting the opening/closing unit may be flat, and the intake air flowing into an inlet of the opening/closing unit changes its moving direction 180 degrees to be exhausted through a passage inlet. 
         [0016]    The average flowing velocity line of the intake air that may be exhausted from the passage of the anti-surge valve to flow into the blade of the compressor may be formed, a crossing point may be formed where the average flowing velocity line and a rotation trace of the blade cross each other, and a horizontal line that passes the crossing point and the rotation center of the blade may be formed, wherein the average flowing velocity line and the horizontal line form a predetermined angle, wherein an inlet opening of the passage may be larger than an outlet opening thereof to form a cone shape, wherein the outlet opening of the passage may be aligned such that the average flowing velocity line may be tangential to the rotation trace of the blade, and wherein the predetermined angle that may be formed by the average flowing velocity line and the horizontal line may be at least 15 degrees. 
         [0017]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a schematic diagram showing a state in which an anti-surge valve does not operate in a turbocharger having an anti-surge valve according to an exemplary embodiment of the present invention. 
           [0019]      FIG. 2  is a schematic diagram showing a state in which an anti-surge valve operates in a turbocharger having an anti-surge valve according to an exemplary embodiment of the present invention. 
           [0020]      FIG. 3  is a partial cross-sectional view showing the internal structure of an anti-surge valve according to an exemplary embodiment of the present invention. 
           [0021]      FIG. 4  is a diagram showing an air stream flowing in an anti-surge valve according to an exemplary embodiment of the present invention. 
           [0022]      FIG. 5  is a schematic cross-sectional view of an anti-surge valve according to an exemplary embodiment of the present invention. 
           [0023]      FIG. 6  is a diagram showing a principle of generating noise in a blade of a compressor according to an exemplary embodiment of the present invention. 
           [0024]      FIG. 7  is a graph showing effectiveness according to an exemplary embodiment of the present invention. 
       
    
    
       [0025]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0026]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0028]    An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings. 
         [0029]      FIG. 1  is a schematic diagram showing a state in which an anti-surge valve does not operate in a turbocharger having an anti-surge valve according to an exemplary embodiment of the present invention. 
         [0030]    Referring to  FIG. 1 , a turbocharger having an anti-surge valve includes an intake line  120 , a throttle valve  150 , an intake manifold  160 , an exhaust line  140 , a turbocharger  130 , and an anti-surge valve  100 . 
         [0031]    The turbocharger  130  includes a turbine  130   b  disposed at the exhaust line  140  and a compressor  130   a  disposed at the intake line  120 , and a bypass line  110  is diverged from the intake line  120  at the downstream side of the compressor  130   a  to join the intake line  120  at the upstream side of the compressor  130   a.    
         [0032]    The anti-surge valve  100  is mounted on the bypass line  110 , a first bypass line  110   a  is formed from the intake line  120  to the anti-surge valve  100 , and a second bypass line  110   b  is formed from the anti-surge valve  100  to the intake line  120 . 
         [0033]    If a driver pushes an accelerator pedal, air is induced through the intake line  120 , the air flows through the compressor  130   a,  the throttle valve  150 , and the intake manifold  160 , and the exhaust gas combusted with fuel is exhausted to the atmosphere through the turbine  130   b  of the exhaust line  140 . 
         [0034]    The turbine  130   b  is rotated by the exhaust gas to rotate the compressor  130   a  so that the compressed air is efficiently supplied through the intake line  120 . 
         [0035]      FIG. 2  is a schematic diagram showing a state in which an anti-surge valve operates in a turbocharger having an anti-surge valve according to an exemplary embodiment of the present invention. 
         [0036]    Referring to  FIG. 2 , if the driver&#39;s foot is taken off the accelerator pedal, the throttle valve  150  is instantly closed, and if the pressure between the compressor  130   a  and the throttle valve  150  is raised, the anti-surge valve  100  is opened. 
         [0037]    Meanwhile, while the compressed air is supplied to the upstream side of the compressor  130   a  through the first bypass line  110   a,  the anti-surge valve  100 , and the second bypass line  110   b,  the compressed air collides with the blade of the compressor  130   a  to generate a high level of noise. 
         [0038]      FIG. 3  is a partial cross-sectional view showing the internal structure of an anti-surge valve according to an exemplary embodiment of the present invention. 
         [0039]    Referring to  FIG. 3 , an inlet  300  is formed at the anti-surge valve  100 , which is connected to the first bypass line  110   a,  and the bypass air flowing into through the inlet  300  flows through a passage  320  to the intake line  120 . 
         [0040]    The second bypass line  110   b  that is described in  FIG. 2  corresponds to the passage  320  described in  FIG. 3 , and if there is no specific comments, it can be determined that the constituent elements are the same. 
         [0041]    The blade of the compressor  130   a  is disposed inside the intake line  120  to rotate at a high speed, and the blade rotates based on a rotation center  360  thereof. 
         [0042]    The air flowing into a passage inlet  310  of the passage  320  is supplied to the blade of the compressor  130   a  through a passage outlet  330 , and the air is supplied to an edge portion except a rotation center portion  365  of the blade. 
         [0043]    Particularly, the air flowing in the passage  320  is supplied in a rotation direction of the blade such that the noise generated when the air collides with the blade is reduced. 
         [0044]    As shown, a line passing an inlet center  350  of the passage  320  and the rotation center  360  of the blade forms a predetermined angle with an average flowing velocity line  340 , wherein it is desirable that the predetermined angle is larger than 15 degrees. 
         [0045]      FIG. 4  is a diagram showing an air stream flowing in an anti-surge valve according to an exemplary embodiment of the present invention. 
         [0046]    The blade of the compressor  130   a  has the rotation center  360 , and a blade rotation trace  400  is formed along the rotation track of the blade. Further, the air passing the passage  320  to flow into the blade forms the average flowing velocity line  340 . 
         [0047]    A horizontal line  410  that passes the rotation center of the blade, and a crossing point  405  where the average flowing velocity line  340  and the blade rotation trace  400  cross, form a predetermined angle (α) with the average flowing velocity line  340 . It is desirable that the predetermined angle (α) is larger than 15 degrees. 
         [0048]    As shown in  FIG. 4 , the average velocity line  340  formed by the intake air flowing into the blade of the compressor  130   a  through the passage  320  is connected to an edge portion except the rotation center  360  of the blade such that the noise generated by the collision of the blade and the air is reduced. 
         [0049]      FIG. 5  is a schematic cross-sectional view of an anti-surge valve according to an exemplary embodiment of the present invention. 
         [0050]    Referring to  FIG. 5 , the anti-surge valve  100  includes a valve plate  500 , an opening/closing unit  620 , a spring  610 , and a negative pressure line  600 . 
         [0051]    An inlet  300  is formed in the valve plate  500 , which is connected to the first bypass line  110   a,  and a passage inlet  310  is formed to be connected to the passage  320 . 
         [0052]    If the opening/closing unit  620  contacts an upper surface of the valve plate  500  by the spring  610 , the inlet  300  and the passage inlet  310  are closed. 
         [0053]    Further, if a negative pressure is formed in the negative pressure line  600 , the opening/closing unit  620  is separated from the upper surface of the valve plate  620  by a predetermined distance such that the inlet  300  and the passage inlet  310  are connected. 
         [0054]    More particularly, if a lower surface of the opening/closing unit  620  contacts the upper surface of the valve plate  500 , the inlet  300  and the passage inlet  310  is closed, and if the lower surface of the opening/closing unit  620  is separated from the upper surface of the valve plate  500  by a predetermined length, the air flows through the inlet  300  and a space between the opening/closing unit  620  and the valve plate  500  to be supplied to the passage inlet  310 . 
         [0055]    In an exemplary embodiment of the present invention, while the air flowing into the inlet  300  flows in a space between the valve plate  500  and the opening/closing unit  620  and the passage inlet  310 , the flowing direction of the air is converted by 180 degrees so that a whistling noise can be easily formed by the change of the flowing direction. 
         [0056]    Meanwhile, in an exemplary embodiment of the present invention, when the opening/closing unit  620  is separated from the valve plate  500 , the lift amount is equal to or larger than the diameter of the passage inlet  310  such that the noise is minimized. 
         [0057]    In another exemplary embodiment of the present invention, when the opening/closing unit  620  is separated from the valve plate  500 , the lift amount is equal to or larger than the diameter of the inlet  300  such that the noise is minimized. 
         [0058]      FIG. 6  is a diagram showing a principle of generating noise in a blade of a compressor according to an exemplary embodiment of the present invention. 
         [0059]    Referring to  FIG. 6 , a rotation trace  400  of the blade is formed in a circle shape, an average flowing velocity line  340  is formed along the flowing line of the air, and an incident angle (Ai) is formed between a tangential line of the rotation trace  400  and the average flowing velocity line  340 . 
         [0060]    The larger the incident angle (Ai) is, the louder the noise generated by the flow separation phenomenon around the blade is, and the smaller the incident angle (Ai) is, the quieter the noise around the blade is. 
         [0061]      FIG. 7  is a graph showing effectiveness according to an exemplary embodiment of the present invention. 
         [0062]    Referring to  FIG. 7 , the horizontal axis is frequency, and the vertical axis shows decibels (size) of the frequency. Compared with the conventional art, the size (decibels) of the noise (frequency) according to an exemplary embodiment of the present invention is remarkably deceased. 
         [0063]    For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
         [0064]    The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.