Patent Publication Number: US-9835051-B2

Title: Water cooled turbine housing

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a turbine housing in which a water passage through which engine coolant flows is formed. 
     2. Description of Related Art 
     A water-cooled turbocharger is proposed in US 2009/0151327 A. In the turbine housing for a turbocharger that is disclosed in US 2009/0151327 A, a gas passage through which exhaust gas flows and a water passage through which coolant flows both extend to open in the part that will be connected to an internal combustion engine (specifically, a connecting flange on the side from which exhaust gas is introduced). Thus, the gas passage is connected to the exhaust passage of the internal combustion engine and the water passage is connected to the water jacket of the internal combustion engine through an operation of attaching the turbine housing to the internal combustion engine. Therefore, the turbocharger can be attached easily compared to the case where the gas passage and the water passage should be connected to the internal combustion engine through separate operations. 
     SUMMARY OF THE INVENTION 
     A metal seal member that prevents leakage of exhaust gas from the gas passage and a rubber O-ring that prevents leakage of coolant from the water passage are provided at the connection between the turbine housing and the internal combustion engine (specifically, between their mating faces). In a turbocharger, there is a possibility that a tiny amount of exhaust gas leaks from the connection between the gas passage and the exhaust passage in spite of the presence of a seal member at the connection. 
     In the turbine housing that is disclosed in US 2009/0151327 A, the gas passage and the water passage open in the same face. Thus, the exhaust gas that leaks from the gas passage into the gap between the mating faces of the turbine housing and the internal combustion engine is blown onto the O-ring between the same mating faces. In this case, the high-temperature exhaust gas may cause thermal degradation of the O-ring, resulting in a deterioration of the sealing performance of the O-ring. 
     The present invention provides a turbine housing which has a structure that enables it to be attached easily and is less likely to cause deterioration of the sealing performance of the water passage. 
     The means for it and its advantages are described below. A turbine housing according an aspect of the present invention includes a water passage, a gas passage, a joint part, a first seal member and a second seal member. The water passage is provided in the turbine housing. The water passage is connected to a water jacket of an internal combustion engine. The gas passage is provided in the turbine housing. The gas passage is connected to an exhaust passage of the internal combustion engine. The joint part is provided at a gas-introducing side of the turbine housing. The joint part has a first mating face in which the water passage opens and a second mating face in which the gas passage opens. The water passage and the gas passage are arranged adjacent to each other in the joint part. The second mating face does not connect smoothly to the first mating face. The first seal member is interposed between the first mating face and the internal combustion engine to prevent coolant from leaking. The second seal member is interposed between the second mating face and the internal combustion engine to prevent exhaust gas from leaking. 
     In the turbine housing, the water passage and the gas passage are arranged in a side-by-side manner in the exhaust gas-introducing side joint part, and the water passage and the gas passage both open at the joint part. Thus, the gas passage can be connected to the exhaust passage and the water passage can be connected to the water jacket through an operation of connecting the joint part to the internal combustion engine (specifically, the cylinder head or exhaust passage thereof). Thus, the turbine housing has a structure that enables it to be attached easily. 
     In addition the first mating face, in which the water passage opens, and the second mating face, in which the gas passage opens, are formed not to connect smoothly to each other. Thus, when exhaust gas leaks from the gas passage onto the second mating face, on which the second seal member is located, the flow of the leaking exhaust gas is disturbed by the part between the first mating face and the second mating face, in other words, the part that do not connect smoothly to the mating face and the second mating face. This is a structure in which the exhaust gas that leaks onto the second mating face is less likely to reach the first mating face compared to the case where the water passage and the gas passage open in the same face. Thus, the turbine housing has a structure in which deterioration of the sealing performance of the water passage that is caused by exposure of the O-ring, which is provided on the first mating face to prevent leakage of coolant from the water passage, is less likely to occur. 
     In the turbine housing, the first mating face, the second mating face, and a connection portion that connects the first mating face to the second mating face may form a shape that is bent at one or more portions between an opening of the water passage and an opening of the gas passage. 
     According to the above turbine housing, because the flow of exhaust gas that leaks from the gas passage onto the second mating face and travels toward the first mating face is less likely to reach the first mating face because it is blocked by the Z-shaped surface. Thus, the first seal member on the first mating face can be prevented from being exposed to high-temperature exhaust gas. 
     In the turbine housing, the bent shape may be a stepwise shape that one of the first mating face and the second mating face protrudes relative to the other of the first mating face and the second mating face. 
     In the turbine housing, the joint part may have a pipe that extends in a direction across the second mating face, the pipe may constitute a part of the water passage, and the first mating face may be an outer periphery of a distal end portion of the pipe. 
     According to turbine housing, the water passage can be connected to the water jacket through an operation of connecting the joint part of the turbine housing to the internal combustion engine with a distal end portion of the pipe inserted into the connecting port of the internal combustion engine. In this case, the first seal member is provided between the outer periphery of the distal end portion of the pipe and the inner periphery of the connecting port of the internal combustion engine to prevent leakage of coolant from the water passage. 
     In the turbine housing, because the pipe extends in a direction across the second mating face, exhaust gas that leaks from the gas passage onto the second mating face is blown onto the outer periphery of the pipe. Thus, the exhaust gas that leaks onto the second mating face is less likely to reach the first mating face, in other words, the outer periphery of the distal end portion of the pipe that is inserted into the internal combustion engine. Thus, the first seal member on the first mating face can be prevented from being exposed to high-temperature exhaust gas. 
     In the turbine housing, the second mating face may be planar, and the pipe may extend in a direction normal to the second mating face. 
     According to the above turbine housing, the exhaust gas that leaks from the gas passage onto the second mating face is blown onto the outer periphery of the pipe almost at a right angle. Thus, the flow of exhaust gas is less likely to be directed toward the first mating face and is therefore unlikely to reach the first mating face. Thus, the first seal member on the first mating face can be suitably prevented from being exposed to high-temperature exhaust gas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein: 
         FIG. 1  is a cross-sectional view that schematically illustrates a cross-sectional structure of a turbocharger to which a turbine housing according to one embodiment which embodies the present invention is applied; 
         FIG. 2  is a schematic diagram that illustrates the manner in which coolant is circulated in an internal combustion engine and the turbine housing; 
         FIG. 3  is a perspective view that illustrates a perspective structure of the turbine housing; 
         FIG. 4  is a side view that illustrates a side structure of a joint part of the turbine housing as seen in the direction of arrow  4  in  FIG. 3 ; 
         FIG. 5  is a side view that illustrates a side structure of the joint part of the turbine housing as seen in the direction of arrow  5  in  FIG. 3 ; and 
         FIG. 6  is a cross-sectional view that illustrates the cross-sectional structure of joint parts and surrounding portions along a direction in which the gas passage and water passage extend. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Description is hereinafter made of a turbine housing according to one embodiment that embodies the present invention. As shown in  FIG. 1 , a turbocharger  11  includes a compressor  20  that is installed in an intake passage  12  of an internal combustion engine  10 , a turbine  30  that is installed in an exhaust passage  13  of the internal combustion engine  10 , and a center housing  41  that couples the compressor  20  and the turbine  30 . 
     A compressor housing  21  defines a compressor chamber  22 , and a compressor wheel  23  is housed in the compressor chamber  22 . A turbine housing  31  defines a turbine chamber  32 , and a turbine wheel  33  is housed in the turbine chamber  32 . A shaft  42  is rotatably supported by the center housing  41 . The compressor wheel  23  is secured to one end of the shaft  42 , and the turbine wheel  33  is secured to the other end of the shaft  42 . The turbocharger  11  is constructed such that the compressor wheel  23  and the turbine wheel  33  rotate together. 
     The compressor chamber  22  extends along the rotation axis L 1  of the compressor wheel  23 . A scroll passage  24  that extends spirally around the compressor wheel  23  is formed in the compressor housing  21 . 
     The turbine chamber  32  extends along the rotation axis L 1  of the turbine wheel  33 . A scroll passage  34  that extends spirally around the turbine wheel  33  is formed in the turbine housing  31 . In this embodiment, the turbine chamber  32  and the scroll passage  34  function as a gas passage  35  through which exhaust gas flows. 
     The turbocharger  11  supercharges the internal combustion engine  10  as described below. When the exhaust gas from the internal combustion engine  10  is blown onto the turbine wheel  33  through the scroll passage  34 , the turbine wheel  33  is rotated by the energy of the exhaust gas stream. Then, the rotation of the turbine wheel  33  is transmitted to the compressor wheel  23  via the shaft  42  and rotates the compressor wheel  23 . Then, in the compressor  20 , the intake air that flows into the compressor chamber  22  through an inlet  20 A of the compressor  20  is fed to the scroll passage  24  then to each cylinder of the internal combustion engine  10  by the effect of the centrifugal force from the rotation of the compressor wheel  23 . The internal combustion engine  10  uses the energy of exhaust gas to supercharge the intake air to improve the engine output. 
     As shown in  FIG. 1  or  FIG. 2 , a water-cooled turbocharger in which a water passage  36  which allows coolant flow through the turbine housing  31  is formed is adopted as the turbocharger  11 . A portion of the coolant that is used to cool the internal combustion engine  10  is supplied to the water passage  36  when the internal combustion engine  10  is being operated. 
     The water passage  36  opens at a joint part  51  on the side from which exhaust gas is introduced into the scroll passage  34  (exhaust gas-introducing side) in the turbine housing  31 . The joint part  51  is secured by bolts to a joint part  16  of a cylinder head  14  of the internal combustion engine  10  at which a water jacket  15  opens. Thus, the water passage  36  of the turbine housing  31  is communicated with the water jacket  15  of the internal combustion engine  10 . 
     When the internal combustion engine  10  is started and a water pump  17  is driven, the coolant that is delivered under pressure by the water pump  17  is circulated through the coolant passage including the water jacket  15 , the water passage  36  and a radiator  18  as indicated by arrows in  FIG. 2 . The internal combustion engine  10  and the turbocharger  11  are cooled by the circulation of the coolant. 
     A metal seal member that prevents leakage of exhaust gas from the gas passage  35  and a rubber O-ring that prevent leakage of coolant from the water passage  36  are provided between the joint part  51  of the turbine housing  31  and the joint part  16  of the cylinder head  14 . In this embodiment, a tiny amount of exhaust gas may leak from the gas passage  35  into a gap between the mating faces of the joint parts  16  and  51  in spite of the presence of the seal member. When the leaking exhaust gas is blown onto the O-ring, the high-temperature exhaust gas may cause thermal degradation of the O-ring, resulting in a deterioration of the sealing performance of the O-ring. 
     In view of this point, a structure is employed in this embodiment which can reduce the possibility that the exhaust gas that leaks into the gap between the mating faces of the joint part  51  of the turbine housing  31  and the joint part  16  of the cylinder head  14  is blown onto the O-ring. The structure is described in detail below. 
     As shown in  FIG. 3  to  FIG. 5 , the water passage  36  and the gas passage  35 , which are formed in the turbine housing  31 , are arranged adjacent to each other (in a side-by-side manner) in the exhaust gas-introducing side joint part  51  of the turbine housing  31 . Also, an exhaust gas-introducing side end  35 A of the gas passage  35 , a water introduction port  36 A through which coolant is introduced into the water passage  36  and a water discharge port  36 B through which coolant is discharged from the water passage  36  open at the joint part  51 . 
     In addition, a mating face  52  in which the water introduction port  36 A of the water passage  36  open and a mating face  53  in which the end  35 A of the gas passage  35  open are both formed in a planar shape and do not connect smoothly to each other in the joint part  51 . Specifically, the joint part  51  is formed in a stepwise configuration with the mating face  52  protruding relative to the mating face  53 . Thus, because a face that extends in a direction across (in this embodiment, normal to) the mating faces  52  and  53  is formed between the mating faces  52  and  53 , the mating faces  52  and  53  do not connect smoothly to each other. In other words, a part where the surface curvature changes more significantly than in the adjacent areas is formed between the mating faces  52  and  53 . 
     In the joint part  51  of the turbine housing  31 , a pipe  54  that forms a part of the water discharge port  36 B of the water passage  36  is also located on the opposite side of the mating face  52  with respect to the mating face  53  and extends in a direction normal to the mating face  53 . The pipe  54  protrudes in such a location that a gap is formed between its outer periphery and the mating face  53 . 
     The effect of forming the joint part  51  of the turbine housing  31  in the shape as described above is described below.  FIG. 6  shows a cross-sectional view that illustrates the cross-sectional structure of the joint parts  16  and  51  and surrounding portions along a direction in which the gas passage  35  and the water passage  36  extend. 
     As shown in  FIG. 4  to  FIG. 6 , the water introduction port  36 A and the water discharge port  36 B of the water passage  36  and the gas passage  35  are arranged side-by-side in the exhaust gas-introducing side joint part  51  of the turbine housing  31 . In addition, the water introduction port  36 A and the water discharge port  36 B of the water passage  36  and the gas passage  35  open at the joint part  51 . In addition, in the joint part  16  of the cylinder head  14 , the water jacket  15  opens at a location corresponding to the opening of the water introduction port  36 A, and a connecting port  16 A into which the pipe  54  can be inserted and which is communicated with the water jacket  15  is formed at a location corresponding to the pipe  54  as shown in  FIG. 6 . The exhaust passage  13  also opens at a location corresponding to the opening of the gas passage  35  in the joint part  16 . 
     Thus, the gas passage  35  can be connected to the exhaust passage  13  and the water introduction port  36 A and the water discharge port  36 B of the water passage  36  can be connected to the water jacket  15  through the operation of securing the joint part  51  of the turbine housing  31  to the joint part  16  of the cylinder head  14  with the distal end of the pipe  54  inserted into the connecting port  16 A of the cylinder head  14 . This is a structure that enables the turbine housing  31 , therefore the turbocharger  11 , to be attached easily. 
     As shown in  FIG. 6 , the turbine housing  31  is attached to the cylinder head  14  with one metal seal member  55  and two rubber O-rings  56  and  57  interposed between the joint part  51  of the turbine housing  31  and the joint part  16  of the cylinder head  14 . The seal member  55  is provided between the mating face  53  of the turbine housing  31  and the joint part  16  of the cylinder head  14  to prevent leakage of exhaust gas from the gas passage  35 . The O-ring  56  is provided between the mating face  52  of the turbine housing  31  and the joint part  16  of the cylinder head  14  to prevent leakage of coolant from the water introduction port  36 A of the water passage  36 . The O-ring  57  is provided between the pipe  54  of the turbine housing  31  and the connecting port  16 A of the cylinder head  14  to prevent leakage of coolant from the water discharge port  36 B of the water passage  36 . 
     In this embodiment, the mating face  52  of the turbine housing  31  and the outer periphery of a distal end portion (specifically, the part which is inserted into the connecting port  16 A of the cylinder head  14 ) of the pipe  54  both function as a first mating face, and the O-rings  56  and  57  both function as a first seal member. In this embodiment, the mating face  53  of the turbine housing  31  functions as a second mating face, and the seal member  55  functions as a second seal member. 
     In addition, the joint part  51  of the turbine housing  31  has a third face normal to the mating faces  52  and  53  between the mating faces  52  and  53 , and the mating faces  52  and  53  and the third face form a shape that is bent at two portions between an opening of the water passage  36  and an opening of the gas passage  35 . The bent shape is a stepwise configuration with the mating face  52  protruding from the mating face  53 . Further, the portions of the joint part  16  of the cylinder head  14  to which the mating faces  52  and  53  are connected also form generally the same stepwise configuration as the mating faces  52  and  53  and the third face do. Thus, the gap between the joint part  16  of the cylinder head  14  and the joint part  51  of the turbine housing  31  is bent in a stepwise fashion. Therefore, the flow of exhaust gas that leaks from the gas passage  35  onto the mating face  53  and travels toward the mating face  52  (the flow indicated by arrows A in  FIG. 5  and  FIG. 6 ) is less likely to reach the mating face  52  because it is blocked by the portion between the mating faces  52  and  53  (or the bent shape). Thus, the turbine housing  31  has a structure in which the exhaust gas that leaks from the gas passage  35  onto the mating face  53  is less likely to reach the mating face  52  compared to the case where the water passage and the gas passage open in the same face. This is a structure in which deterioration of the sealing performance of the water introduction port  36 A of the water passage  36  that is caused by exposure of the O-ring  56  on the mating face  52  to high-temperature exhaust gas is less likely to occur. 
     In addition, in the turbine housing  31 , the exhaust gas that leaks from the gas passage  35  onto the mating face  53  is blown onto the outer periphery of the pipe  54  as indicated by arrow B in  FIG. 5  and  FIG. 6  because the pipe  54  is located at a distance from the mating face  53  and extends in a direction normal to the mating face  53 . Especially, the turbine housing  31  has a structure in which the exhaust gas that leaks onto the mating face  53  is less likely to be directed toward the gap between the pipe  54  and the connecting port  16 A and is therefore unlikely to flow into the gap compared to the case where the direction in which the gap between the pipe  54  and the connecting port  16 A extends form a dull angle with the direction in which the exhaust gas is blown onto the outer periphery of the pipe  54  because the exhaust gas is blown onto the outer periphery of the pipe  54  almost at a right angle. Thus, the turbine housing  31  has a structure in which the exhaust gas that leaks from the gas passage  35  onto the mating face  53  is less likely to flow into the gap between the pipe  54  and the connecting port  16 A compared to the case where the water discharge port and the gas passage open in the same face. This is a structure in which deterioration of the sealing performance of the O-ring  57  in the gap between the pipe  54  and the connecting port  16 A that is caused by exposure of the O-ring  57  to high-temperature exhaust gas is less likely to occur. 
     As described above, this embodiment provides the following advantages. (1) The gas passage  35  and the water introduction port  36 A of the water passage  36  are arranged adjacent to each other in the joint part  51  of the turbine housing  31 , and a third face is formed between the mating face  52 , in which the water introduction port  36 A opens, and the mating face  53 , in which the gas passage  35  opens. The mating faces  52  and  53  and the third face form the above bent shape. Thus, the turbine housing  31  has a structure that enables it to be attached easily. In addition, this is a structure in which deterioration of the sealing performance of the water introduction port  36 A of the water passage  36  that is caused by exposure of the O-ring  56  on the mating face  52  to high-temperature exhaust gas is less likely to occur. 
     (2) The joint part  51  of the turbine housing  31  is formed to have a stepwise configuration with the mating face  52 , in which the water introduction port  36 A opens, protruding relative to the mating face  53 , in which the gas passage  35  opens. Thus, a portion having the above bent shape can be formed between the mating faces  52  and  53 . Alternatively, the mating faces  52  and  53  and the face between the mating faces  52  and  53  can form the above bent shape. 
     (3) The gas passage  35  and the water discharge port  36 B of the water passage  36  are arranged adjacent to each other in the joint part  51  of the turbine housing  31 , and the pipe  54 , which constitutes a part of the water discharge port  36 B, protrudes in a direction across the mating face  53 , in which the gas passage  35  opens. Thus, the turbine housing  31  has a structure that enables it to be attached easily. In addition, this is a structure in which deterioration of the sealing performance of the water discharge port  36 B of the water passage  36  that is caused by exposure of the O-ring  57  in the gap between the pipe  54  and the connecting port  16 A of the cylinder head  14  to high-temperature exhaust gas is less likely to occur. 
     (4) The mating face  53  of the turbine housing  31  is formed to have a planar shape and the pipe  54  extends in a direction normal to the mating face  53 . This is a structure in which exhaust gas is less likely to flow into the gap between the pipe  54  and the connecting port  16 A. 
     The above embodiment may be implemented with any of the following modifications. The mating face  52 , in which the water introduction port  36 A of the water passage  36  opens, and the mating face  53 , in which the gas passage  35  opens, may be partially or entirely curved slightly. 
     The pipe  54  does not necessarily have to extend normal to the mating face  53  and may extend in any direction across the mating face  53 . The joint part  51  of the turbine housing  31  may be formed in a stepwise configuration such that the mating face in which the gas passage  35  open protrudes relative to the mating face in which the water introduction port  36 A open. 
     A structure in which a pipe extends in a direction across the mating face  53 , in which the gas passage  35  open, and the pipe constitutes a part of the water introduction port  36 A may be adopted instead of the structure in which the water introduction port  36 A opens in the planar mating face  52 . With this structure, the turbine housing is attached to the internal combustion engine with the end of the pipe inserted into the connecting port of the internal combustion engine and a rubber O-ring is provided between the outer periphery of a distal end portion of the pipe and the inner periphery of the connecting port of the internal combustion engine. 
     A structure in which the water discharge port  36 B opens in a planar mating face of the turbine housing  31  may be adopted instead of the structure in which the pipe  54 , which extends in a direction across the mating face  53 , in which the gas passage  35  open, constitutes a part of the water discharge port  36 B. With this configuration, the joint part of the turbine housing is formed in a stepwise configuration with one of the mating faces in which the pipe  54  and the water discharge port  36 B open protruding relative to the other of the mating faces. 
     Only one of the water introduction port  36 A and water discharge port  36 B of the water passage  36  may be formed in the joint part  51  of the turbine housing  31 .