JP6699446B2 - Engine exhaust system - Google Patents

Description

  The present invention relates to an exhaust system for an engine.

  In vehicles such as automobiles, a catalytic converter that purifies exhaust gas is provided in an exhaust path of an engine. When the turbocharger is provided in the exhaust path of the engine, the turbocharger is connected between the engine body and the catalytic converter.

  BACKGROUND ART Conventionally, as an engine exhaust system including a turbocharger and a catalytic converter, one described in Patent Document 1 is known. In the one described in Patent Document 1, a catalyst converter having a container (catalyst case) formed of sheet metal is integrally welded to a straight portion of a cast exhaust pipe called a turbo outlet, and the exhaust pipe is turbocharged. Connecting to a supercharger is disclosed.

  In the exhaust device for an engine described in Patent Document 1, the number of flanges can be reduced by integrating the catalyst case and the exhaust pipe, so the exhaust pipe and the catalyst can be formed simply by fastening the upstream end of the exhaust pipe to the turbocharger. Both cases can be assembled at one time, simplifying the assembly workability.

Japanese Utility Model Publication No. 2-7316

  However, in Patent Document 1, for example, when the exhaust pipe is fastened from the side of the turbocharger, in order to secure a working space on the side of the turbocharger, the catalyst case is provided by a turbocharger. Also needs to be placed at a lower position, or the catalyst case needs to be placed at a position separated laterally of the turbocharger.

  For this reason, in the one described in Patent Document 1, although the workability of fastening the exhaust pipe to the turbocharger is improved, in the case of a vehicle with a narrow engine room, the space for arranging the catalyst case cannot be sufficiently secured, and the catalyst There was a risk that the mountability of the case on the vehicle would deteriorate.

  Further, in the device disclosed in Patent Document 1, as a result of arranging the catalyst case at a position that does not hinder the fastening work of the exhaust pipe to the turbocharger, the catalyst case is arranged in an inappropriate position or posture, and the exhaust gas is not used as a catalyst. There was a risk that the catalyst could not be evenly flowed into the case.

  An object of the present invention is to provide an exhaust system for an engine that can improve the layout flexibility of a catalyst case connected to an exhaust pipe without impairing the workability of fastening the exhaust pipe to the turbocharger. ..

  The present invention includes a turbocharger arranged laterally of an engine body, an exhaust pipe connected to the turbocharger, and a catalyst case connected to the exhaust pipe. An exhaust device of an engine, wherein exhaust gas discharged from a machine is introduced from an exhaust pipe inlet of the exhaust pipe through an exhaust pipe outlet into the catalyst case, wherein the exhaust pipe is around the exhaust pipe inlet. An exhaust pipe inlet side flange provided to the turbocharger and fastened to the turbocharger, and an exhaust pipe outlet side flange provided around the exhaust pipe outlet, and the catalyst case has the exhaust pipe outlet side. A catalyst case inlet side flange that is fastened to the flange; and a conical trapezoidal exhaust gas introduction pipe portion that expands in diameter from the catalyst case inlet side flange toward the downstream side in the exhaust flow direction, the exhaust pipe outlet side The flange is inclined with respect to the exhaust pipe inlet side flange so that the lower portion from the upper portion approaches the exhaust pipe inlet side flange, and when the exhaust pipe is viewed from the side opposite to the turbocharger, the exhaust pipe The exhaust pipe is formed so that the exhaust pipe inlet can be visually recognized from the outlet and most of the exhaust pipe outlet overlaps the exhaust pipe inlet in the vertical and horizontal directions.

  As described above, according to the present invention, the degree of freedom in layout of the catalyst case connected to the exhaust pipe can be improved without impairing the workability of fastening the exhaust pipe to the turbocharger.

FIG. 1 is a left side view of an engine including an exhaust device according to an embodiment of the present invention. FIG. 2 is a plan view of an engine including an exhaust device according to an embodiment of the present invention. FIG. 3 is a rear side view of an engine including an exhaust device according to an embodiment of the present invention. FIG. 4 is a left side view of an exhaust pipe and a catalyst case of an engine exhaust system according to an embodiment of the present invention. FIG. 5 is a plan view of an exhaust pipe and a catalyst case of an engine exhaust system according to an embodiment of the present invention. FIG. 6 is a rear side view of an exhaust pipe and a catalyst case of an exhaust system for an engine according to an embodiment of the present invention. FIG. 7 is a rear side view of the exhaust pipe of the exhaust system for an engine according to the embodiment of the present invention, as viewed from the side opposite to the turbocharger.

  An exhaust system for an engine according to an embodiment of the present invention includes a turbocharger arranged laterally of an engine body, an exhaust pipe connected to the turbocharger, and a catalyst case connected to the exhaust pipe. An exhaust device for an engine, in which exhaust gas discharged from a turbocharger is introduced from an exhaust pipe inlet of an exhaust pipe through an exhaust pipe outlet into a catalyst case, and the exhaust pipe is An exhaust pipe inlet side flange provided around the pipe inlet and fastened to the turbocharger, and an exhaust pipe outlet side flange provided around the exhaust pipe outlet, and the catalyst case has an exhaust pipe outlet side. The exhaust pipe outlet side flange has a catalyst case inlet side flange that is fastened to the flange, and a truncated cone-shaped exhaust gas introduction pipe section that expands from the catalyst case inlet side flange toward the downstream side in the exhaust flow direction. , The lower part from the upper part is inclined with respect to the exhaust pipe inlet side flange so that the lower part approaches the exhaust pipe inlet side flange, and when the exhaust pipe is viewed from the side opposite to the turbocharger, the exhaust pipe outlet is visible from the exhaust pipe outlet The exhaust pipe is formed so that it can be formed and most of the exhaust pipe outlet overlaps the exhaust pipe inlet in the vertical and horizontal directions. As a result, the engine exhaust system according to the embodiment of the present invention improves the layout flexibility of the catalyst case connected to the exhaust pipe without impairing the workability of fastening the exhaust pipe to the turbocharger. You can

  Hereinafter, an exhaust system for an engine according to an embodiment of the present invention will be described with reference to the drawings. 1 to 7 are views showing an exhaust system for an engine according to an embodiment of the present invention. 1 to 7, the up, down, left, and right directions indicate the directions viewed from the driver who gets on the vehicle.

  In FIG. 1, an engine 10 is mounted on the front part of a vehicle 1. The engine 10 is a three-cylinder engine that includes three cylinders in series, and is vertically arranged in an engine room 1B formed in front of the dash panel 1A so that the cylinder row direction is the front-rear direction of the vehicle 1. There is. The dash panel 1A is provided in front of a driver's seat (not shown) and separates the engine room 1B from the driver's seat.

  1, 2, and 3, an engine 10 includes a cylinder block 13, a cylinder head 14 provided on the cylinder block 13, a cylinder head cover 15 closing an upper end of the cylinder head 14, and a lower portion of the cylinder block 13. And an oil pan 16 for storing oil.

  The cylinder block 13, the cylinder head 14, the cylinder head cover 15, and the oil pan 16 constitute the engine body 11. A transmission mounting surface 11A is provided on the rear portion of the engine body 11, and a transmission (not shown) is mounted on the transmission mounting surface 11A.

  Three intake ports 14A are provided on the right side surface of the cylinder head 14, and the intake ports 14A communicate with a combustion chamber (not shown) of the cylinder head 14. The intake port 14A is connected to a branch pipe of an intake manifold (not shown) and introduces the air distributed by the intake manifold into the combustion chamber.

  One exhaust port 14B is provided on the left side surface of the cylinder head 14, and the exhaust port 14B communicates with each of the combustion chambers (not shown) of the cylinder head 14 and gathers inside the cylinder head 14. , The exhaust gas from the combustion chamber is combined and discharged.

  Further, the engine 10 includes an exhaust introduction pipe 24, a turbocharger 25, an exhaust pipe 30, and a catalyst case 40 on the left side of the engine body 11. An exhaust introduction pipe 24 is connected to the exhaust port 14B. A turbocharger 25 is connected to a downstream end of the exhaust introduction pipe 24 in the exhaust flow direction.

  The turbocharger 25 includes a turbine housing 25A and a compressor housing 25B. The exhaust gas introducing pipe 24 is integrally connected to the turbine housing 25A, and the exhaust gas passing through the exhaust gas introducing pipe 24 is introduced therein. The turbine housing 25A discharges exhaust gas toward the rear. A connecting surface of the turbocharger 25 with the exhaust pipe 30 is formed along a vertical plane extending in the left-right direction. An intake pipe (not shown) is connected to the compressor housing 25B, and air that has passed through an air cleaner (not shown) and the intake pipe is introduced.

  A turbine wheel and a compressor wheel (not shown) are provided in the turbine housing 25A and the compressor housing 25B. The turbine wheel and the compressor wheel are integrally rotatably connected by a rotation shaft (not shown).

  In the turbocharger 25, the turbine wheel is driven by the exhaust gas introduced into the turbine housing 25A from the exhaust introduction pipe 24, so that the compressor wheel of the compressor housing 25B compresses air. Thus, the turbocharger 25 pressurizes the air introduced from the intake pipe by the kinetic energy of the exhaust gas discharged from the engine body 11.

  The exhaust pipe 30 is connected to the turbine housing 25A of the turbocharger 25. The exhaust gas discharged from the turbine housing 25A is introduced into the exhaust pipe 30. An exhaust gas sensor 36 is provided on the upper surface of the exhaust pipe 30.

  The catalyst case 40 is connected to the downstream end of the exhaust pipe 30 in the exhaust flow direction. The exhaust gas discharged from the exhaust pipe 30 is introduced into the catalyst case 40. Exhaust gas is purified by the catalyst contained inside the catalyst. The catalyst case 40 extends rearward and downward in a space between the left side surface of the engine body 11 and the dash panel 1A.

  Next, detailed configurations of the exhaust pipe 30 and the catalyst case 40 will be described.

  4 and 5, the exhaust pipe 30 has an exhaust pipe inlet 30A at the upstream end in the exhaust flow direction and an exhaust pipe outlet 30B at the downstream end in the exhaust flow direction. The exhaust pipe 30 is formed in a linear shape as a whole, and extends horizontally rearward from the exhaust pipe inlet 30A at the same height as the turbocharger 25. The exhaust pipe inlet 30A and the exhaust pipe outlet 30B are even formed in an oval shape that is long in the vertical direction. The exhaust gas discharged from the turbocharger 25 passes through the exhaust pipe inlet 30A of the exhaust pipe 30 and the exhaust pipe outlet 30B and is introduced into the catalyst case 40.

  The upper surface 30C of the exhaust pipe 30 extends horizontally rearward from the exhaust pipe inlet 30A side, and then slightly bends downward in the vicinity of the end portion on the exhaust pipe outlet 30B side. On the other hand, the lower surface 30D of the exhaust pipe 30 extends so as to be inclined rearward.

  The exhaust pipe 30 has an internal passage 30E having a substantially constant wall thickness with respect to the upper surface 30C and the lower surface 30D. For this reason, the lower surface of the internal passage 30E is inclined upward toward the rear. The vertical width of the internal passage 30E is wide on the exhaust pipe inlet 30A side and becomes narrower as it approaches the exhaust pipe outlet 30B. The width of the internal passage 30E in the left-right direction is substantially constant.

  The exhaust pipe 30 has an exhaust pipe inlet side flange 31 around the exhaust pipe inlet 30A, and the exhaust pipe inlet side flange 31 is fastened to the turbocharger 25. The exhaust pipe inlet side flange 31 is formed along a vertical plane extending in the left-right direction.

  Further, the exhaust pipe 30 has an exhaust pipe outlet side flange 32 around the exhaust pipe outlet 30B. The exhaust pipe outlet side flange 32 of the exhaust pipe 30 is inclined with respect to the exhaust pipe inlet side flange 31 so that the lower portion of the exhaust pipe 30 approaches the exhaust pipe inlet side flange 31 from its upper portion.

  Further, the exhaust pipe outlet 30B is opened in the same direction as the direction of the exhaust pipe outlet side flange 32 (the direction of the catalyst case 40). The lower surface 30D of the exhaust pipe 30 extends parallel to the joint surface of the exhaust pipe outlet side flange 32.

  As described above, in this embodiment, the exhaust pipe 30 is slightly curved only in the vicinity of the exhaust pipe outlet 30B, and the lower surface of the exhaust pipe 30 is not curved, instead of bending the entire exhaust pipe 30 toward the catalyst case 40. 30D is connected to the outer peripheral portion of the inclined exhaust pipe outlet side flange 32. The exhaust pipe outlet side flange 32 is arranged at a high position while the cross-sectional area of the internal passage 30E of the exhaust pipe 30 is preferably reduced toward the downstream side in the exhaust flow direction.

  4, 5, and 6, the catalyst case 40 has a catalyst case inlet 40A at the upstream end in the exhaust flow direction and a catalyst case outlet 40B at the downstream end in the exhaust flow direction. The catalyst case inlet 40A is formed in an oblong shape that is the same size as the exhaust pipe outlet 30B and is long in the vertical direction, and opens forward and upward along the axial direction of the catalyst case 40. The catalyst case inlet 40A is arranged on the center line of the catalyst case 40.

  The catalyst case 40 has a catalyst case inlet side flange 41 around the catalyst case inlet 40A, and the catalyst case inlet side flange 41 is fastened to the exhaust pipe outlet side flange 32. With the catalyst case inlet side flange 41 fastened to the exhaust pipe outlet side flange 32, the exhaust pipe outlet 30B and the catalyst case inlet 40A communicate with each other with the same size.

  The catalyst case inlet side flange 41 is formed along a surface perpendicular to the opening direction of the catalyst case inlet 40A. As described above, in the present embodiment, the exhaust pipe outlet side flange 32 is inclined, rather than the catalyst case inlet side flange 41 being inclined with respect to the catalyst case 40 or being offset from the center in the radial direction.

  The catalyst case 40 has a truncated cone-shaped exhaust gas introduction pipe portion 43, and the diameter of the exhaust gas introduction pipe portion 43 increases from the catalyst case inlet side flange 41 toward the downstream side in the exhaust flow direction.

  The catalyst case 40 has a cylindrical main body portion 44, and the cylindrical main body portion 44 is provided on the downstream side of the exhaust gas introduction pipe portion 43 in the exhaust flow direction. In this way, the main body portion 44 is connected to the exhaust pipe 30 via the exhaust gas introduction pipe portion 43. Therefore, the catalyst case 40 having the main body 44 has a larger diameter and a larger passage area than the exhaust pipe 30.

  A catalytic converter (not shown) is housed in the main body 44, and the catalytic converter is formed by adhering a catalytic substance such as platinum, rhodium or palladium on the surface of a lattice-shaped carrier made of ceramic or the like.

  The catalyst case 40 has a truncated cone-shaped exhaust gas lead-out pipe portion 45, and the diameter of the exhaust gas lead-out pipe portion 45 is reduced from the main body portion 44 toward the downstream side in the exhaust flow direction. The catalyst case 40 has a cylindrical connecting pipe 46, and the connecting pipe 46 is provided at the downstream end of the exhaust gas outlet pipe portion 45 in the exhaust flow direction.

  As shown in FIG. 7, when the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the exhaust pipe inlet 30A can be visually recognized from the exhaust pipe outlet 30B, and most of the exhaust pipe outlet 30B is arranged in the vertical and horizontal directions. The exhaust pipe 30 is formed so as to overlap the exhaust pipe inlet 30A in the direction.

  Here, when the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, in other words, when the exhaust pipe 30 is viewed from the rear, or the exhaust pipe 30 is moved from the exhaust pipe outlet 30B to the exhaust pipe inlet 30A. This is the case when looking at it.

  That is, the exhaust pipe 30 is not largely curved or bent, and has a shape close to a straight line so that the exhaust pipe outlet 30B can visually recognize the exhaust pipe inlet 30A when viewed from the rear. The exhaust pipe 30 extends substantially horizontally toward the rear so that most of the exhaust pipe outlet 30B overlaps the exhaust pipe inlet 30A in the vertical and horizontal directions when viewed from the rear.

  When the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the exhaust pipe inlet 30A and the exhaust pipe outlet 30B are each formed in a vertically long shape.

  On the outer peripheral portion of the exhaust pipe inlet side flange 31, four inlet side fastened portions 31A1, 31A2, 31A3, 31A4 protruding outward are provided. The exhaust pipe inlet side flange 31 is formed in a substantially rectangular shape when viewed from the rear.

  On the outer peripheral portion of the exhaust pipe outlet side flange 32, three outlet side fastened portions 32A1, 32A2, 32A3 protruding outward are provided. The exhaust pipe outlet side flange 32 is formed in a substantially triangular shape when viewed from the rear.

  When the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the outlet side fastened part 32A1 is located between two inlet side fastened parts 31A1 and 31A4 that are adjacent to each other in the circumferential direction of the exhaust pipe inlet side flange 31. It is arranged. The outlet side fastened portions 32A2 are arranged between two inlet side fastened portions 31A1 and 31A2 that are adjacent to each other in the circumferential direction of the exhaust pipe inlet side flange 31. The outlet side fastened portion 32A3 is arranged between two inlet side fastened portions 31A3, 31A4 that are adjacent to each other in the circumferential direction of the exhaust pipe inlet side flange 31.

  Inlet side through holes 31B1, 31B2, 31B3, 31B4 are provided in the inlet side fastened parts 31A1, 31A2, 31A3, 31A4, respectively. An inlet side fastener 34 for fastening the exhaust pipe inlet side flange 31 to the turbocharger 25 passes through the inlet side through holes 31B1, 31B2, 31B3, 31B4.

  The inlet-side fastener 34 is a bolt or a stud bolt embedded in the turbocharger 25 side. A nut or bolt (not shown) that is screwed into the inlet side fastener 34 is fastened from the space behind the exhaust pipe inlet side flange 31 using a fastening tool.

  When the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the interval D1 between the two inlet-side through holes 31B1 and 31B2 that are vertically adjacent to each other is equal to the two inlet-side through holes 31B1 and 31B4 that are adjacent to each other in the horizontal direction. Is set larger than the interval D2.

  Outlet side through holes 32B1, 32B2, 32B3 are provided in the outlet side fastened portions 32A1, 32A2, 32A3, respectively. The outlet side fasteners 35 for fastening the exhaust pipe outlet side flange 32 to the catalyst case inlet side flange 41 penetrate through the outlet side through holes 32B1, 32B2, 32B3.

  The outlet side fastener 35 is, for example, a bolt, and is fastened using a fastening tool from a space above and in front of the exhaust pipe outlet side flange 32. The catalyst case inlet side flange 41 is formed with an internal thread into which the outlet side fastener 35 is screwed.

  4 and 7, the exhaust gas sensor 36 projects upward from the upper surface of the exhaust pipe 30 and projects downward into the internal passage 30E.

  The exhaust gas sensor 36 is inclined so that its lower end faces the downstream in the exhaust flow direction in the internal passage 30E. This makes it difficult for moisture discharged together with the exhaust gas to adhere to the exhaust gas sensor 36, so that the water content of the exhaust gas sensor 36 can be reduced.

  When the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the inlet-side fastened portions 31A1, 31A2, 31A3, 31A4 are arranged at positions that do not overlap the exhaust gas sensor 36. Further, the outlet side fastened portions 32A1, 32A2, 32A3 are between the two of the inlet side fastened portions 31A1, 31A2, 31A3, 31A4 that are adjacent to each other in the circumferential direction of the exhaust pipe inlet side flange 31, and the exhaust gas sensor 36. It is arranged in a position where it does not overlap with as much as possible.

  Accordingly, the inlet-side fastened portions 31A1, 31A2, 31A3, 31A4 of the exhaust pipe inlet-side flange 31 can be connected to the turbocharger without interfering with the outlet-side fastened portions 32A1, 32A2, 32A3 of the exhaust pipe outlet-side flange 32. 25, and the workability of fastening the turbocharger 25 and the exhaust pipe 30 can be improved.

  Next, the operation will be described. In this embodiment, the exhaust pipe 30 includes an exhaust pipe inlet side flange 31 provided around the exhaust pipe inlet 30A and fastened to the turbocharger 25, and an exhaust pipe outlet side provided around the exhaust pipe outlet 30B. And a flange 32.

  Further, the catalyst case 40 includes a catalyst case inlet side flange 41 that is fastened to the exhaust pipe outlet side flange 32, and a truncated cone-shaped exhaust gas introduction whose diameter increases from the catalyst case inlet side flange 41 toward the downstream side in the exhaust flow direction. And a tube portion 43.

  Thus, when the exhaust pipe 30 and the catalyst case 40 having a larger diameter and a larger passage area than the exhaust pipe 30 are assembled to the turbocharger 25, the catalyst case 40 is removed from the exhaust pipe 30 at the exhaust pipe outlet side flange 32. It can be separated. Therefore, the exhaust pipe 30 with the catalyst case 40 separated can be connected to the turbocharger 25 via the exhaust pipe inlet side flange 31.

  Therefore, by separating the catalyst case 40, a working space for fastening the exhaust pipe 30 to the turbocharger 25 can be secured, and due to the interference of the catalyst case 40, the work of fastening the exhaust pipe 30 to the turbocharger 25. Is not disturbed.

  Therefore, it is not necessary to set the layout of the catalyst case 40 in consideration of the workability of fastening the exhaust pipe inlet side flange 31 to the turbocharger 25, and the degree of freedom in layout of the catalyst case 40 is improved. The layout of the catalyst case 40 means the arrangement and posture of the catalyst case 40.

  In addition to this, in the present embodiment, the exhaust pipe outlet side flange 32 is inclined with respect to the exhaust pipe inlet side flange 31 so that the lower portion of the exhaust pipe outlet side flange 32 approaches the exhaust pipe inlet side flange 31.

  Further, in the present embodiment, when the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the exhaust pipe inlet 30A can be visually recognized from the exhaust pipe outlet 30B, and most of the exhaust pipe outlet 30B is in the vertical and horizontal directions. The exhaust pipe 30 is formed so as to overlap the exhaust pipe inlet 30A in the direction.

  As a result, it is possible to prevent the exhaust gas from flowing in the exhaust pipe 30 in one radial direction of the exhaust pipe outlet 30B. Therefore, the exhaust gas that has passed through the exhaust pipe 30 can flow into the central portion of the catalyst case 40, and the exhaust gas can flow evenly into the catalyst case 40.

  As a result, the layout flexibility of the catalyst case 40 connected to the exhaust pipe 30 can be improved without impairing the workability of fastening the exhaust pipe 30 to the turbocharger 25.

  In this embodiment, when the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the exhaust pipe inlet 30A and the exhaust pipe outlet 30B are each formed in a vertically long shape.

  As a result, the exhaust pipe inlet 30A and the exhaust pipe outlet 30B are made vertically long, so that the exhaust gas is radially outer peripheral portion of the catalyst case 40 as compared with the case where the exhaust pipe inlet 30A and the exhaust pipe outlet 30B have a simple circular cross section. It can also be flushed.

  Further, the lateral width of the exhaust pipe outlet side flange 32 can be reduced to secure a space necessary for assembling the exhaust pipe inlet side flange 31, and the assemblability of the exhaust pipe inlet side flange 31 to the turbocharger 25 can be improved. be able to.

  In the present embodiment, the exhaust pipe inlet-side flange 31 and the exhaust pipe outlet-side flange 32 have an inlet-side fastened portion 31A1, 31A2, 31A3, 31A4, and an outlet-side fastened portion 32A1, 32A2, 32A3 on their outer peripheral portions. Is equipped with.

  When the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the outlet side fastened parts 32A1, 32A2, 32A3 are the exhaust pipe inlet side flanges of the fastened inlet side fastened parts 31A1, 31A2, 31A3, 31A4. It is arranged between two adjacent 31 in the circumferential direction.

  Accordingly, the inlet-side fastened portions 31A1, 31A2, 31A3, 31A4 of the exhaust pipe inlet-side flange 31 can be connected to the turbocharger without interfering with the outlet-side fastened portions 32A1, 32A2, 32A3 of the exhaust pipe outlet-side flange 32. 25, and the workability of fastening the turbocharger 25 and the exhaust pipe 30 can be improved.

  In the present embodiment, the inlet-side fastened portions 31A1, 31A2, 31A3, 31A4 are the inlet-side through holes through which the inlet-side fastener 34 for connecting the turbocharger 25 with the 31A1, 31A2, 31A3, 31A4 passes. 31B1, 31B2, 31B3, 31B4 are provided.

  When the exhaust pipe 30 is viewed from the side opposite to the turbocharger 25, the distance D1 between the two inlet-side through holes 31B1 and 31B2 that are vertically adjacent to each other is equal to the two inlet-side through holes 31B1 that are adjacent to each other in the left-right direction. , 31B4 is set to be larger than the interval D2.

  As a result, as described above, while arranging the outlet side fastened portions 32A1, 32A2, 32A3 between adjacent ones of the inlet fastened portions 31A1, 31A2, 31A3, 31A4, the inclination angle of the exhaust pipe outlet side flange 32 is increased. Can be set freely. Therefore, the degree of freedom in layout of the catalyst case 40 can be improved.

  While an embodiment of this invention has been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of this invention. All such modifications and equivalents are intended to be included in the following claims.

  1... vehicle, 10... engine, 11... engine body, 25... turbocharger, 30... exhaust pipe, 30A... exhaust pipe inlet, 30B... exhaust pipe outlet , 31... Exhaust pipe inlet side flange, 31A1, 31A2, 31A3, 31A4... Inlet side fastened part, 31B1, 31B2, 31B3, 31B4... Inlet side through hole, 32... Exhaust pipe outlet side Flange, 32A1, 32A2, 32A3... Outlet-side fastened part, 34... Inlet-side fastener, 40... Catalyst case, 41... Catalyst case inlet-side flange, 43... Exhaust gas introduction pipe Department

Claims (4)

A turbocharger arranged on the side of the engine body,
An exhaust pipe connected to the turbocharger,
A catalyst case connected to the exhaust pipe,
Exhaust gas exhausted from the turbocharger is an exhaust device of an engine, which is introduced into the catalyst case from an exhaust pipe inlet of the exhaust pipe through an exhaust pipe outlet,
The exhaust pipe has an exhaust pipe inlet side flange provided around the exhaust pipe inlet and fastened to the turbocharger, and an exhaust pipe outlet side flange provided around the exhaust pipe outlet. ,
The catalyst case includes a catalyst case inlet side flange that is fastened to the exhaust pipe outlet side flange, and a truncated cone-shaped exhaust gas introduction pipe portion that expands in diameter from the catalyst case inlet side flange toward a downstream side in an exhaust flow direction. Has,
The exhaust pipe outlet side flange is inclined with respect to the exhaust pipe inlet side flange so that a lower portion from the upper portion approaches the exhaust pipe inlet side flange,
When the exhaust pipe is viewed from the side opposite to the turbocharger,
The exhaust pipe is formed such that the exhaust pipe inlet can be visually recognized from the exhaust pipe outlet, and most of the exhaust pipe outlet overlaps the exhaust pipe inlet in a vertical direction and a horizontal direction. Exhaust system of the engine. When the exhaust pipe is viewed from the side opposite to the turbocharger,
The exhaust system for an engine according to claim 1, wherein the exhaust pipe inlet and the exhaust pipe outlet are each formed in a vertically long shape. The exhaust pipe inlet-side flange and the exhaust pipe outlet-side flange each have a plurality of inlet-side fastened portions and outlet-side fastened portions on their outer peripheral portions,
When the exhaust pipe is viewed from the side opposite to the turbocharger,
The said outlet side to-be-fastened part is arrange|positioned between the two said inlet side to-be-fastened parts which adjoin the circumferential direction of the said exhaust pipe inlet side flange, The claim 1 or claim 2 characterized by the above-mentioned. Exhaust system of the engine. The inlet-side fastened portion has an inlet-side through hole through which an inlet-side fastener for connecting the inlet-side fastened portion to the turbocharger penetrates,
When the exhaust pipe is viewed from the side opposite to the turbocharger,
The exhaust system for an engine according to claim 3, wherein an interval between two inlet-side through holes that are vertically adjacent to each other is set to be larger than an interval between two adjacent inlet-side through holes in the horizontal direction.

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