Abstract:
A wastegate is disclosed for use with a turbocharger in an exhaust system. The wastegate may have a housing at least partially defining an elongated inlet passage, and an elongated outlet passage arranged in parallel orientation relative to the elongated inlet passage. The wastegate may also have a first valve opening connecting the elongated inlet and outlet passages, and a first valve member disposed in the first valve opening and configured to move in a direction substantially orthogonal to a length direction of the elongated inlet and outlet passages. The wastegate may additionally have a second valve opening connecting the elongated inlet and outlet passages, and a second valve member disposed in the second valve opening.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to an exhaust system and, more particularly, to an exhaust system having a remotely mounted multi-valve wastegate. 
       BACKGROUND 
       [0002]    Turbocharged engines often employ bypass devices, commonly known as wastegates, to regulate a turbocharger speed and a resulting boost pressure of air delivered to an intake of the engine. A typical wastegate is mounted directly to the turbocharger or associated exhaust manifold, and includes a single valve disposed within an exhaust system of the engine and a pneumatic actuator used to move the valve. The pneumatic actuator selectively moves the valve to modify a volume of exhaust gases directed into or bypassed around a turbine of the turbocharger. Boost air pressure is supplied from a compressor of the turbocharger to the pneumatic actuator to control movement of the connected valve. As boost air pressure increases, a force of the pneumatic actuator gradually urges the valve to open, thereby bypassing a greater amount of exhaust around the turbine and lowering turbocharger speed and boost air pressure. As boost air pressure decreases, the pneumatic. actuator returns the valve toward a closed position such that more exhaust passes through the turbine, thereby increasing turbocharger speed and boost air pressure. 
         [0003]    In some applications, a greater amount of exhaust gases may need to bypass the turbine than can be provided by a single wastegate. In these situations, multiple wastegates are utilized to handle the increased volume of gases. While effective, the use of multiple wastegates can create packaging and control problems. 
         [0004]    One attempt to improve wastegate packaging is disclosed in W.O. Patent Publication No. 2013/121111 of NYNÄS that published on Aug. 22, 2013 (“the &#39;111 publication”), Specifically, the &#39;111 publication describes a system having a valve arrangement for controlling gas flow in a turbocharged internal combustion piston engine. The valve arrangement includes two or more parallel valve units connected to a bypass channel of a turbocharger. Each valve unit includes a butterfly valve member, the valve members of all units being arranged in a common body. A diverging connecting member directs exhaust from the bypass channel axially through each valve unit to a converging connecting member. In this compact configuration, a large number of valves may be used to control a large flow of exhaust gas bypassing a turbine of the turbocharger. 
         [0005]    While the system of the &#39;111 publication may help to reduce an amount of space consumed by multiple wastegates, it may still be less than optimal. In particular, the system utilizes butterfly valve members, which may not seal completely. In addition, the design may require the valve units to be positioned axially within the bypass channel at the turbocharger, which can limit packaging options. 
         [0006]    The present disclosure is directed at overcoming one or more of the shortcomings set forth above and/or other problems of the prior art. 
       SUMMARY 
       [0007]    In one aspect, the present disclosure is directed to a wastegate for use with a turbocharger. The wastegate may include a housing at least partially defining an elongated inlet passage and an elongated outlet passage arranged in substantially parallel orientation relative to the elongated inlet passage. The wastegate may also have a first valve opening connecting the elongated inlet and outlet passages, and a first valve member disposed in the first valve opening and configured to move in a direction substantially orthogonal to a length direction of the elongated inlet and outlet passages. The wastegate may additionally have a second valve opening connecting the elongated inlet and outlet passages, and a second valve member disposed in the second valve opening. 
         [0008]    In another aspect, the present disclosure is directed to another wastegate. This wastegate may include a housing at least partially defining an elongated inlet passage having an open end and a closed end and an elongated outlet passage arranged in substantially parallel orientation relative to the elongated inlet passage and having an open end and a closed end. The wastegate may also include a. first valve opening connecting the elongated inlet and outlet passages, a first valve seat located at the first valve opening, and a first poppet valve disposed in the first valve opening and biased to engage the first valve seat. The wastegate may further include a second valve opening connecting the elongated inlet and outlet passages, a second valve seat located at the second valve opening, a second poppet valve biased to engage the second valve seat. The wastegate may additionally include a first pneumatic actuator configured to move the first poppet valve away from the first valve seat, and a second pneumatic actuator configured to Move the second poppet valve away from the second valve seat. 
         [0009]    In another aspect, the present disclosure is directed to an exhaust system. The exhaust system may include an exhaust manifold configured to receive exhaust from the engine, an exhaust stack configured to direct exhaust to the atmosphere, and a turbocharger fluidly connected between the exhaust manifold and the exhaust stack. The exhaust system may also include a wastegate configured to selectively direct exhaust gases from the exhaust manifold to bypass the turbocharger and flow into the exhaust stack. The wastegate may include a housing at least partially defining an inlet passage having an open end in fluid communication with the exhaust passage and a closed end, and an outlet passage having an open end in fluid communication with the exhaust stack and a closed end. The wastegate may further include a first valve opening connecting the inlet and outlet passages, a first poppet valve disposed in the first valve opening, a second valve opening connecting the inlet and outlet passages, and a second poppet valve disposed in the second valve opening. The first and second poppet valves pass completely through the outlet passage to close off the first and second valve openings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a diagrammatic illustration of an engine having an exemplary disclosed exhaust system; 
           [0011]      FIG. 2  is an isometric illustration of an exemplary disclosed wastegate that may be used with the exhaust system of  FIG. 1 ; and 
           [0012]      FIG. 3  a cross-sectional illustration of the wastegate of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  illustrates an exemplary engine  10 . For the purposes of this disclosure, engine  10  is depicted and described as a diesel-fueled, internal combustion engine. However, it is contemplated that engine  10  may embody any other type of combustion engine such as, for example, a gasoline-fueled engine or a gaseous fuel-powered engine burning compressed or liquefied natural gas, propane, or methane. Engine  10  may include an engine block  12  at least partially defining a plurality of cylinders  14 , and a plurality of piston assemblies (not shown) disposed within cylinders  14  to form a plurality of combustion chambers (not shown). It is contemplated that engine  10  may include any number of combustion chambers and that the combustion chambers may be disposed in an in-line configuration (shown), in a “V” configuration, in an opposing-piston configuration, or in any other conventional configuration. 
         [0014]    Multiple separate sub-systems may be associated within engine  10  and cooperate to facilitate the production of power. For example, engine  10  may include an air induction system  16  and an exhaust system  18 . Air induction system  16  may be configured to direct air or an air and fuel mixture into engine  10  for subsequent combustion. Exhaust system  18  may exhaust byproducts of combustion to the atmosphere. 
         [0015]    Air induction system  16  may include multiple components configured to condition and introduce compressed air into cylinders  14 . For example, air induction system  16  may include an air cooler  22  located downstream of one or more compressors  24 . Compressor(s)  24  may be connected to cooler  22  (e.g., via a passage  20 ), and configured to pressurize inlet air directed through cooler  22  and into cylinders  14  of engine  10 . It is contemplated that air induction system  16  may include different or additional components than described above such as, for example, a throttle valve, variable valve actuators associated with each cylinder  14 , filtering components, compressor bypass components, and other known components that may be selectively controlled to affect an air-to-fuel ratio of engine  10 , if desired. It is further contemplated that cooler  22  may be omitted, if desired. 
         [0016]    Exhaust system  18  may include multiple components that condition and direct exhaust from cylinders  14  to the atmosphere. For example, exhaust system  18  may include an exhaust passage  26  (e.g., an exhaust manifold), one or more turbines  28  driven by exhaust flowing through passage  26 , and an exhaust stack  30  connected to an outlet of turbine(s)  28 . It is contemplated that exhaust system  18  may include different or additional components than described above such as, for example, aftertreatment components, an exhaust compression or restriction brake, an attenuation device, and other known components, if desired. 
         [0017]    Turbine(s)  28  may be located to receive exhaust leaving engine  10 , and may be connected to one or more compressors  24  of air induction system  16  by way of a common shaft  32  to form a turbocharger  34 . As the hot exhaust gases exiting engine  10  move through turbine(s)  28  and expand against vanes (not shown) thereof, turbine(s)  28  may rotate and drive the connected compressor(s)  24  to pressurize inlet air. 
         [0018]    In some applications, the amount of exhaust being discharged from cylinders  14  of engine  10  may be more than a desired amount that should pass through turbine(s)  28 . That is, in these situations, if all of the exhaust were to be directed through turbine(s)  28 , the exhaust could cause overspeeding of turbocharger  34 , excessive boost pressures, surging, and/or other related problems. For this reason, exhaust system  18  may also include a wastegate  36  fluidly connected between exhaust passage  26  and stack  30  (e.g., in parallel with turbine(s)  28 ). Wastegate  36  may form a portion of a bypass loop that selectively allows a controlled amount of exhaust to bypass turbine(s)  28  and flow directly from exhaust passage  26  to stack  30 . The amount of exhaust that bypasses turbine(s)  28  may be controlled based on a turbocharger speed, an inlet manifold boost pressure (Le., a pressure of passage  20 ), a temperature (e.g., an exhaust or inlet air temperature), a fuel control value of engine  10 , or based on any other parameter known in the art. 
         [0019]    An exemplary wastegate  36  is illustrated in  FIGS. 2 and 3 . As can be seen in these figures, wastegate  36  may include a housing  38 , a plurality of valve elements  40  (shown only in  FIG. 3 ) movably disposed within housing  38 , and an actuator  42  associated with each valve element  40 . Actuators  42  may be configured to selectively move valve elements  40  between flow-blocking and flow-passing positions, to thereby fluidly communicate exhaust passage  26  with stack  30  and bypass a desired amount of exhaust around turbine(s)  28 . 
         [0020]    Housing  38  may at least partially define elongated inlet and outlet passages  44 ,  46 , each having an open end  48  and a closed end  50 . A common flange  52  may be located at open ends  48 , and facilitate connection of inlet and outlet passages  44 ,  46  with exhaust passage  26  and exhaust stack  30 , respectively. A plurality of valve openings  54  may be spaced apart in a length direction of housing  38  between open and closed ends  48 ,  50 , and configured to fluidly connect inlet passage  44  with outlet passage  46 . Although two such openings  54  are shown in  FIG. 3 , it is contemplated that more than two may be included, if desired. Central axes  56  of inlet and outlet passages  44 ,  46  may be substantially parallel (e.g., within about 0-5°) with each other, and a central axis  58  of each opening  54  may be oriented substantially (e.g., within about 0-5°) orthogonal to axes  56 . In this configuration, exhaust flowing through inlet passage  44  may need to be diverted through about 180° before exiting back out of housing  38  via outlet passage  46 . 
         [0021]    Valve openings  54  may each include an annular valve seat  60  configured to be engaged by a corresponding one of valve elements  40 . In particular, valve elements  40  may embody poppet type valves having a beveled annular surface  62  configured to engage seat  60  and thereby close off openings  54 . As will be explained in more detail below, valve elements  40  may move between a flow-blocking position (at which elements  40  engage seats  60  blocking flow therebetween) and a flow-passing position (at which elements  40  are away from seats $ 0  allowing flow therebetween). Valve elements  40  may be spring biased into engagement with seats  60  and selectively moved away from seats  60  by actuators  42 , 
         [0022]    Actuators  42  may be configured to mount onto an outer wall of housing  38 , for example to an outer wall of outlet passage  46 . In this configuration, valve elements  40  may be generally aligned with axis  58 , and pass from seats  60  completely through outlet passage  46  to actuators  42 . Accordingly, the movement of valve elements  40  may be in a direction aligned with axis  58 . Actuators  42  may each engage an actuator mount  64  integrally formed with (e.g., protruding from) housing  38  at the outer wall of outlet passage  46 . In the disclosed embodiment, actuator mount  64  may have an engagement face that is oriented generally perpendicular to an engagement face of common flange  52 . 
         [0023]    Actuators  42  may be pneumatic type actuators, In particular, each of actuators  42  may include an inlet port  66  (shown only in  FIG. 2 ) configured to receive a flow of compressed air (or other gas). When a pressure of the air exceeds an opening pressure of valve elements  40 , valve elements  40  may be moved away from openings  60 . As the pressure of the air falls below the opening pressure, valve elements  40  may be biased back into engagement with seats  60 . Many conventional pneumatic actuator known in the art may be used for this purpose. 
         [0024]    It is contemplated that actuators  42  may be operated independently and separately, or dependently and simultaneously, as desired. For example, a single manifold (not shown) could fluidly couple a high-pressure air source to both inlet ports  66  in parallel, such that both actuators  42  may be exposed to the same pressure at the same time. Assuming that both actuators  42  have the same bias acting to push valve elements  40  closed, the same control pressure should cause valve elements  40  of actuators  42  to open at the same time and by the same amount. In this same configuration, however, if a different bias is exerted on the valve elements  40  of two different actuators  42 , valve elements  40  may move at different times and/or by different amounts. Alternatively, each actuator  42  may be connected to its own air source (not shown) and be controlled completely separately, as desired. 
         [0025]    Wastegate  36  may be configured for mounting remotely from turbocharger  34 . In particular, one or more mounting features  6 $ may be integrally formed with housing  38 , allowing wastegate  36  to be mounted in any orientation and at any location on or near engine  10 . For example, the disclosed wastegate  36  is shown with four mounting bosses  68 , one located at each corner of wastegate  36  (e.g., at each end of inlet and outlet passages  44 ,  46 ). This may allow for wastegate  36  to be bolted to a side of engine  10  away from turbocharger  34 , and exhaust passage  26  and/or stack  30  then extended to common flange  52 . It is contemplated that additional conduits, tubes, and/or hoses (not shown) may be used to connect exhaust passage  26  and/or stack  30  to wastegate  36 , if desired. 
       INDUSTRIAL APPLICABILITY 
       [0026]    The disclosed exhaust system and wastegate of the present disclosure may be applicable to any engine application, where turbocharger exhaust bypass is desired in a compact space. The disclosed wastegate provides for the exhaust bypass in a compact configuration by utilizing multiple valve elements within a common housing. 
         [0027]    Several advantages may be associated with the disclosed exhaust system and wastegate. For example, because the disclosed wastegate may utilize poppet type valves, better flow control over bypassing exhaust may be achieved. That is, poppet type valves may seal better over other types of valves commonly used in wastegate applications. In addition, because the disclosed wastegate can be mounted at any location within the exhaust system, packaging flexibility may be improved. Further, the unique configuration of inlet and outlet passages, combined with the location and operational direction of the disclosed valve elements may further improve packaging without sacrificing performance. 
         [0028]    It will be apparent to those skilled in the art that various modifications and variations can be made to the exhaust system and wastegate of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the exhaust system and wastegate disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.