US20110126522A1 - Exhaust apparatus for transverse engine - Google Patents
Exhaust apparatus for transverse engine Download PDFInfo
- Publication number
- US20110126522A1 US20110126522A1 US12/958,194 US95819410A US2011126522A1 US 20110126522 A1 US20110126522 A1 US 20110126522A1 US 95819410 A US95819410 A US 95819410A US 2011126522 A1 US2011126522 A1 US 2011126522A1
- Authority
- US
- United States
- Prior art keywords
- exhaust
- vehicle
- pipe portions
- branch pipe
- pipe portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K13/00—Arrangement in connection with combustion air intake or gas exhaust of propulsion units
- B60K13/04—Arrangement in connection with combustion air intake or gas exhaust of propulsion units concerning exhaust
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K5/00—Arrangement or mounting of internal-combustion or jet-propulsion units
- B60K5/04—Arrangement or mounting of internal-combustion or jet-propulsion units with the engine main axis, e.g. crankshaft axis, transversely to the longitudinal centre line of the vehicle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/08—Other arrangements or adaptations of exhaust conduits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/08—Other arrangements or adaptations of exhaust conduits
- F01N13/10—Other arrangements or adaptations of exhaust conduits of exhaust manifolds
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/18—Construction facilitating manufacture, assembly, or disassembly
- F01N13/1805—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body
- F01N13/1811—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body with means permitting relative movement, e.g. compensation of thermal expansion or vibration
- F01N13/1816—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body with means permitting relative movement, e.g. compensation of thermal expansion or vibration the pipe sections being joined together by flexible tubular elements only, e.g. using bellows or strip-wound pipes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/18—Construction facilitating manufacture, assembly, or disassembly
- F01N13/1805—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body
- F01N13/1811—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body with means permitting relative movement, e.g. compensation of thermal expansion or vibration
- F01N13/1822—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body with means permitting relative movement, e.g. compensation of thermal expansion or vibration for fixing exhaust pipes or devices to vehicle body
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2340/00—Dimensional characteristics of the exhaust system, e.g. length, diameter or volume of the apparatus; Spatial arrangements of exhaust apparatuses
- F01N2340/04—Dimensional characteristics of the exhaust system, e.g. length, diameter or volume of the apparatus; Spatial arrangements of exhaust apparatuses characterised by the arrangement of an exhaust pipe, manifold or apparatus in relation to vehicle frame or particular vehicle parts
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Definitions
- the present invention belongs to a technical field relating to an exhaust apparatus for a transverse engine which is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a widthwise direction of the vehicle (vehicle-widthwise direction).
- an exhaust apparatus for the transverse engine is disposed on a vehicle-rear side of the engine (see, for example, JP 2008-260472A; this document will hereinafter be referred to as “Patent Document 1”).
- the exhaust apparatus has a plurality of branch pipe portions each communicated with a respective one of a plurality of cylinders of the engine, wherein the branch pipe portions are merged to finally form a single exhaust pipe portion.
- the entire cylinders (four cylinders) are divided into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other (a cylinder group consisting of the first (#1) and fourth (#4) cylinders, and a cylinder group consisting of the second (#2) and third (#3) cylinders), and the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups are merged on a cylinder group-by-cylinder group basis to form a plurality of (two) intermediate collector pipe portions. Then, the two intermediate collector pipe portions are merged together to form a single exhaust pipe portion. In some cases, all of the branch pipe portions are merged together to form a single collector pipe portion, without providing the intermediate collector pipe portions.
- an exhaust gas-purifying unit In late years, with a view to reducing exhaust gas emissions during engine warm-up (when an engine is in a cold start mode), an exhaust gas-purifying unit has been provided on a relatively upstream side of an exhaust gas stream to quickly raise a temperature of a catalyst in the exhaust gas-purifying unit.
- an exhaust gas-purifying unit manifold catalytic converter
- the exhaust apparatus in the Patent Document 1 is also designed to increase a length of each of the branch pipe portions and the intermediate collector pipe portions.
- the two intermediate collector pipe portions are disposed inside a tunnel portion formed in a vehicle-widthwise central region of a floor panel.
- the present invention has been made in view of the above background art. It is therefore an object of the present invention to, in an exhaust apparatus for a transverse engine, make it possible to compactly lay out an upstream exhaust assembly thereof including an exhaust gas-purifying unit, in an engine compartment without sacrificing a passenger compartment space, and quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during engine warm-up.
- the present invention is directed to an exhaust apparatus provided in an engine having a plurality of cylinders arranged in a line, wherein the engine is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction, and coupled with a transmission located on one side thereof in the cylinder arrangement direction.
- the exhaust apparatus comprises an upstream exhaust assembly connected to a surface of the engine on a vehicle-rear side, and a downstream exhaust pipe provided on an exhaust downstream side of the upstream exhaust assembly.
- the upstream exhaust assembly includes: a plurality of branch pipe portions communicated with respective ones of the plurality of cylinders and extending from the vehicle-rear-side surface of the engine toward the vehicle-rear side; a single exhaust pipe portion provided on the exhaust downstream side of the plurality of branch pipe portions in such a manner that it is communicated with the branch pipe portions; and an exhaust gas-purifying unit connected to an exhaust downstream end of the single exhaust pipe portion.
- the exhaust gas-purifying unit is disposed on the vehicle-rear side of the engine to allow a gas passage thereinside to extend approximately in the vehicle-widthwise direction, in top plan view.
- the upstream exhaust assembly includes, on an exhaust upstream side of the single exhaust pipe portion, a section which curves to allow an exhaust downstream region of the section to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
- the single exhaust pipe portion curves to allow an exhaust downstream region of the single exhaust pipe portion to be oriented toward a vehicle-front side, in top plan view.
- the downstream exhaust pipe is connected to an exhaust downstream end of the exhaust gas-purifying unit, and disposed to extend from a connection portion thereof with the exhaust gas-purifying unit toward an tunnel opening formed in a vehicle-widthwise central region of a lower end of a dash panel of the vehicle.
- FIG. 1 is a top plan view showing a mounted state of an exhaust apparatus according to a first embodiment of the present invention, with respect to a vehicle.
- FIG. 2 is a side view showing the mounted state of the exhaust apparatus with respect to the vehicle, when viewed from a left side of the vehicle.
- FIG. 3 is a top plan view showing an upstream exhaust assembly, and an upstreammost one of a plurality of divided pipe members of a downstream exhaust pipe, in the exhaust apparatus.
- FIG. 4 is a side view showing the upstream exhaust assembly, and the upstreammost pipe member of the downstream exhaust pipe, in the exhaust apparatus, when viewed from the left side of the vehicle.
- FIG. 5 is a view showing the upstream exhaust assembly, and the upstreammost pipe member of the downstream exhaust pipe, in the exhaust apparatus, when viewed from a rear side of the vehicle.
- FIG. 6 is a view corresponding to FIG. 3 , illustrating a second embodiment of the present invention.
- FIG. 7 is a view corresponding to FIG. 4 , illustrating the second embodiment.
- FIG. 8 is a view corresponding to FIG. 5 , illustrating the second embodiment.
- FIG. 9 is a view corresponding to FIG. 3 , illustrating a third embodiment of the present invention.
- FIG. 10 is a view corresponding to FIG. 4 , illustrating the third embodiment.
- FIG. 11 is a view corresponding to FIG. 5 , illustrating the third embodiment.
- FIG. 12 is a view corresponding to FIG. 3 , illustrating a fourth embodiment of the present invention.
- FIG. 13 is a view corresponding to FIG. 4 , illustrating the fourth embodiment.
- FIG. 14 is a view corresponding to FIG. 5 , illustrating the fourth embodiment.
- FIGS. 1 and 2 show an exhaust apparatus E according to a first embodiment of the present invention.
- the exhaust apparatus E is designed for a transverse engine 1 .
- the engine 1 is an inline four-cylinder engine having four cylinders 2 arranged in a line, and transversely placed in an engine compartment 19 at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction (rightward-leftward direction in FIG. 1 ).
- a right side of the vehicle which corresponds to a right side in FIG. 1 (reverse side of the drawing sheet of FIG. 2 )
- a left side of the vehicle which corresponds to a left side in FIG. 1 (obverse side of the drawing sheet of FIG.
- a front side of the vehicle which corresponds to an upper side in FIG. 1 left side in FIG. 2
- a rear side of the vehicle which corresponds to a lower side in FIG. 1 right side in FIG. 2
- vehicle-right side a front side of the vehicle which corresponds to an upper side in FIG. 1
- vehicle-front side a rear side of the vehicle which corresponds to a lower side in FIG. 1
- vehicle-rear side a front side of the vehicle which corresponds to a lower side in FIG. 1
- the engine 1 is disposed offset toward a vehicle-right side (right side in FIG. 1 ) in the engine compartment 19 . Further, the engine 1 is disposed in an inclined posture to allow an axis of each of the cylinders 2 to be oriented upwardly and toward a vehicle-rear side.
- the engine 1 is coupled with a transmission 11 located on one side thereof in the cylinder arrangement direction (in the first embodiment, on a vehicle-left side (left side in FIG. 1 )).
- a combination of the engine 1 and the transmission 11 makes up a power plant 12 .
- the transmission 11 is a transverse type having a non-illustrated input shaft and a non-illustrated output shaft each extending in the vehicle-widthwise direction.
- the input shaft is coupled to a crankshaft of the engine 1 extending in the vehicle-widthwise direction, and the output shaft is coupled to a differential gear mechanism 14 disposed on the vehicle-rear side of the transmission 11 .
- right and left front wheel drive axles each coupled to a corresponding one of right and left front wheels extend from the differential gear mechanism 14 toward respective ones of opposite sides of the vehicle-widthwise direction.
- the vehicle is an FF (front engine, front wheel drive) vehicle in which the right and left front wheels are driven by the engine 1 . It is understood that the vehicle may be a four-wheel-drive vehicle.
- a left side frame 21 and a right side frame 22 are provided on respective ones of opposite sides of the power plant 12 in the vehicle-widthwise direction.
- the left side frame 21 and the right side frame 22 are disposed on a left side close to the transmission 11 and on a right side close to the engine 1 , respectively, to extend in an frontward-rearward direction of the vehicle (vehicle-longitudinal direction).
- a vehicle-rear-side wall of the engine compartment 19 is made up of a dash panel 23 partitioning between the engine compartment 19 and a passenger compartment 20 .
- the dash panel 23 extends in an upward-downward direction and in the vehicle-widthwise direction.
- An upper end of the dash panel 23 is joined to a cowl member 24
- a lower end of the dash panel 23 is joined to a front end of a floor panel 25 defining a floor surface of the passenger compartment 20 .
- the floor panel 25 has a tunnel portion 25 a formed in a vehicle-widthwise central region thereof to bulge upwardly in a cross-sectionally generally inverted-U shape and extend in the vehicle-longitudinal direction.
- the dash panel 23 has a tunnel opening 23 a which is a upwardly-extending cutout formed in a vehicle-widthwise central region of the lower end thereof to communicate with the tunnel portion 25 a.
- a single exhaust pipe (after-mentioned downstream exhaust pipe 51 ) will pass through an inner space of the tunnel portion 25 a (outside of the passenger compartment 20 ).
- an exhaust pipe and a drive shaft for driving rear wheels will pass through the inner space of the tunnel portion 25 a.
- An intake manifold 4 is provided on a vehicle-front side of the engine 1 to introduce intake air into each of the cylinders 2 of the engine 1 .
- the intake manifold 4 has four branch pipe portions 4 a, 4 b, 4 c, 4 d each connected to a respective one of four intake ports (not shown) which are communicated with respective ones of the four cylinders 2 of the engine 1 and opened on a vehicle-front-side surface of the engine 1 .
- the branch pipe portions 4 a to 4 d are curvedly formed to surround a surge tank 5 extending in the cylinder arrangement direction (vehicle-widthwise direction).
- the exhaust apparatus E is provided on the vehicle-rear side of the engine 1 to discharge exhaust gas produced in each of the cylinders 2 of the engine 1 . With reference to FIGS. 3 to 5 , details of the exhaust apparatus E will be specifically described below.
- the exhaust apparatus E comprises an exhaust manifold 31 , a manifold catalytic converter 40 as a unit for purifying exhaust gas of the engine 1 (exhaust gas-purifying unit), and a downstream exhaust pipe 51 , which are arranged in this order from an exhaust upstream side (upstream side of an exhaust gas stream).
- a combination of the exhaust manifold 31 and the manifold catalytic converter 40 makes up an upstream exhaust assembly 48 of the exhaust apparatus E.
- the upstream exhaust assembly 48 is housed in the engine compartment 19 .
- the exhaust manifold 31 includes four branch pipe portions 32 communicated with respective ones of the four cylinders 2 of the engine 1 , two intermediate collector pipe portions 33 each formed by merging two of the four branch pipe portions 32 together, and one single exhaust pipe portion 34 formed by merging the two intermediate collector pipe portions 33 together.
- the manifold catalytic converter 40 is connected to an exhaust downstream end of the single exhaust pipe portion 34 .
- first cylinder 2 a first cylinder 2 a
- second cylinder 2 b second cylinder 2 b
- third cylinder 2 c third cylinder 2 c
- fourth cylinder 2 d fourth cylinder 2 d
- branch pipe portions 32 communicated with respective ones of the first to fourth cylinders 2 a to 2 d will be referred to respectively as “first branch pipe portion 32 a ”, “second branch pipe portion 32 b ”, “third branch pipe portion 32 c ” and “forth branch pipe portion 32 d ”. When it is not necessary to distinguish between them in this manner, they will be referred to simply as “branch pipe portions 32 ” on a case-by-case basis.
- each of the first to fourth branch pipe portions 32 a to 32 d is connected to a surface of the engine 1 on a vehicle-rear side through a flange portion 36 provided to be shared by all of the branch pipe portions 32 a to 32 d and extending in the vehicle-widthwise direction.
- the flange portion 36 is attached to the vehicle-rear-side surface of the engine 1 to allow the exhaust upstream ends of the first to fourth branch pipe portions 32 a to 32 d to be connected to respective ones of four exhaust ports (not shown) opened on the vehicle-rear-side surface of the engine 1 , through the flange portion 36 , so that the first to fourth branch pipe portions 32 a to 32 d are communicated with respective ones of the first to fourth cylinders 2 a to 2 d.
- the flange portion 36 has a plurality of (in the first embodiment, five) fastening points 37 each adapted to be fastened to the vehicle-rear-side surface of the engine 1 by a fastening member such as a bolt.
- Each of the fastening points 37 is formed as a through-hole for allowing the fastening member such as a bolt to be inserted thereinto.
- the five fastening points 37 will be referred to respectively as “first fastening point 37 a ”, “second fastening point 37 b ”, “third fastening point 37 c ”, “fourth fastening point 37 d ” and “fifth fastening point 37 e ”, in order from the vehicle-right side. When it is not necessary to distinguish between them in this manner, they will be referred to simply as “fastening points 37 ” on a case-by-case basis.
- the first fastening point 37 a is provided in the flange portion 36 at a position corresponding to a region on a vehicle-widthwise outer side (vehicle-right side) of the first cylinder 2 a.
- the second fastening point 37 b is provided in the flange portion 36 at a position corresponding to a region between the first cylinder 2 a and the second cylinder 2 b
- the third fastening point 37 c is provided in the flange portion 36 at a position corresponding to a region between the second cylinder 2 b and the third cylinder 2 c.
- the fourth fastening point 37 d is provided in the flange portion 36 at a position corresponding to a region between the third cylinder 2 c and the fourth cylinder 2 d
- the fifth fastening point 37 e is provided in the flange portion 36 at a position corresponding to a region on a vehicle-widthwise outer side (vehicle-left side) of the fourth cylinder 2 d.
- the first to fifth fastening points 37 a to 37 e are arranged such that two lines each connecting a part of the fastening points extend in the vehicle-widthwise direction (cylinder arrangement direction) in spaced-apart relation to each other in a heightwise direction.
- the upper fastening point line including the second and fourth fastening points 37 b, 37 d is located at a first height position adjacent to an upper edge of the flange portion 36
- the lower fastening point line including the first, third and fifth fastening points 37 a, 37 c, 37 e is located at a second height position adjacent to a lower edge of the flange portion 36 .
- each of the second and fourth fastening points 37 b, 37 d corresponds to a high-position fastening point provided at the first height position
- each of the first, third and fifth fastening points 37 a, 37 c, 37 e corresponds to a low-position fastening point provided at the second height position below the first height position.
- first to fifth fastening points 37 a to 37 e are arranged in a zigzag pattern to allow each of the fastening points 37 on the upper line to be located in a corresponding one of two regions between adjacent ones of the fastening points 37 on the lower line.
- Each of the intermediate collector pipe portions 33 is formed by dividing the four cylinders 2 into two cylinder groups each consisting of two cylinders 2 whose exhaust strokes (expansion strokes) are not successive with respect to each other, and merging the branch pipe portions 32 communicated with respective ones of the two cylinders 2 in each of the cylinder groups, on a cylinder group-by-cylinder group basis.
- the exhaust stroke occurs in the following order: the first cylinder 2 a ⁇ the third cylinder 2 c ⁇ the fourth cylinder 2 d ⁇ the second cylinder 2 b.
- the four cylinders 2 are divided into a cylinder group consisting of the first cylinder 2 a and the fourth cylinder 2 d, and a cylinder group consisting of the second cylinder 2 b and the third cylinder 2 c.
- the first and fourth branch pipe portions 32 a, 32 d communicated with respective ones of the first and fourth cylinders 2 a, 2 d are merged together to form one of the intermediate collector pipe portions 33
- the second and third branch pipe portions 32 b, 32 c communicated with respective ones of the second and third cylinders 2 b, 2 c are merged together to form the other intermediate collector pipe portion 33 .
- first intermediate collector pipe portion 33 a first intermediate collector pipe portion 33 a
- second intermediate collector pipe portion 33 b intermediate collector pipe portion 33 b
- Each of the first to fourth branch pipe portions 32 a to 32 d extends from the vehicle-rear-side surface of the engine 1 (in a strict sense, from the flange portion 36 ), basically toward the vehicle-rear side. More specifically, in top plan view, the first branch pipe portion 32 a extends from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side. In top plan view, the fourth branch pipe portion 32 d extends from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side.
- the first branch pipe portion 32 a and the fourth branch pipe portion 32 d are merged together at approximately the same vehicle-widthwise position as that of the third fastening point 37 c, and the first intermediate collector pipe portion 33 a is formed on an exhaust downstream side of the merging position.
- the second branch pipe portion 32 b extends from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side.
- the second branch pipe portion 32 b curves toward the opposite side and extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side.
- the third branch pipe portion 32 c extends from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side.
- the second branch pipe portion 32 b and the third branch pipe portion 32 c are merged together at approximately the same vehicle-widthwise position as that of the second fastening point 37 b, and the second intermediate collector pipe portion 33 b is formed on the exhaust downstream side of the merging position.
- Each of the second and third branch pipe portions 32 b , 32 c extends from the vehicle-left side toward the vehicle-right side of the first branch pipe portion 32 a, while passing across a region just below the first branch pipe portion 32 a.
- respective exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b are disposed offset with respect to each other in the vehicle-widthwise direction.
- an exhaust upstream end of the first intermediate collector pipe portion 33 a (the merging position of the first and fourth branch pipe portions 32 a, 32 d ) is located on the vehicle-left side of (on the side of the transmission 11 with respect to) an exhaust upstream end of the second intermediate collector pipe portion 33 b (the merging position of the second and third branch pipe portions 32 b, 32 c ).
- a height position of the exhaust upstream end of the first intermediate collector pipe portion 33 a is approximately equal to a height position of the exhaust upstream end of the second intermediate collector pipe portion 33 b (in a strict sense, slightly above a height position of the exhaust upstream end of the second intermediate collector pipe portion 33 b ), and located below the third fastening point 37 c.
- This arrangement makes it possible to keep an area around each of the fastening points 37 (particularly, the third fastening point 37 c ) of the flange portion 36 and a region just above the area from overlapping the branch pipe portions 32 and the intermediate collector pipe portions 33 , when viewed from the vehicle-rear side, as shown in FIG. 5 .
- the first and second intermediate collector pipe portions 33 a, 33 b are merged together while curving to allow respective exhaust downstream regions of the first and second intermediate collector pipe portions 33 a, 33 b to be oriented toward one side of the vehicle-widthwise direction (in the first embodiment, toward the vehicle-left side, i.e., toward the transmission 11 ), in top plan view, and the single exhaust pipe portion 34 is formed on the exhaust downstream side of the merging position of the first and second intermediate collector pipe portions 33 a, 33 b .
- the first intermediate collector pipe portion 33 a extends from the exhaust upstream end thereof toward the vehicle-rear side, and then curves toward the vehicle-left side
- the second intermediate collector pipe portion 33 b curves toward the vehicle-left side directly from the exhaust upstream end thereof, and extends toward the vehicle-left side while passing across a region just below the exhaust upstream end of the first intermediate collector pipe portion 33 a.
- the first and second intermediate collector pipe portions 33 a, 33 b are merged together at approximately the same position as that of the fourth cylinder in the vehicle-widthwise direction (at a portion near a vehicle-widthwise central region of the engine compartment 19 ) to form the single exhaust pipe portion 34 .
- the single exhaust pipe portion 34 is provided on the exhaust downstream side of the branch pipe portions 32 , and communicated with the four branch pipe portions 32 a to 32 d via the first and second intermediate collector pipe portions 33 a, 33 b.
- the single exhaust pipe portion 34 is connected to the manifold catalytic converter 40 while curving to allow an exhaust downstream region of the single exhaust pipe portion 34 to be oriented toward the vehicle-front side, in top plan view.
- the exhaust downstream region of the single exhaust pipe portion 34 curves toward the vehicle-front side with an inclination toward the vehicle-right side, and the single exhaust pipe portion 34 has an intermediate region formed in a curved shape which is convexed toward a side opposite to the manifold catalytic converter 40 (toward the vehicle-left side) with respect to both ends of the single exhaust pipe portion 34 .
- the exhaust downstream end of the single exhaust pipe portion 34 is increased in diameter to have the same diameter as that of an after-mentioned casing 41 of the manifold catalytic converter 40 , and connected to an exhaust upstream end surface of the casing 41 (a left end surface of the casing 41 on the vehicle-left side).
- the manifold catalytic converter 40 is disposed on the vehicle-rear side of the engine 1 , and disposed to allow a gas passage inside the casing 41 to extend approximately in the vehicle-widthwise direction, in top plan view.
- the casing 41 extends approximately along the vehicle-rear-side surface of the engine 1 .
- the casing 41 gas passage
- the casing 41 is inclined to be gradually shifted toward the vehicle-rear side by a slight distance as going toward the vehicle-left side (exhaust upstream side). This is intended to allow a gas entry angle with respect to an exhaust upstream end surface 43 a of a catalyst installation portion 43 to be set as close as possible to 90 degrees, as described later.
- the casing 41 (gas passage) is inclined to be gradually shifted downwardly by a slight distance as going toward the vehicle-right side (exhaust downstream side). This is because the downstream exhaust pipe 51 is located just below the second and third branch pipe portions 32 b, 32 c and the second intermediate collector pipe portion 33 b, i.e., intended to avoid interference with these portions ( 32 b, 32 c, 33 b ).
- the manifold catalytic converter 40 is formed by installing a catalyst in a gas passage inside an generally cylindrical-shaped casing 41 .
- a catalyst installation portion 43 in the gas passage inside the casing 41 has a generally circular shape in cross-section.
- Each of an exhaust upstream end surface 43 a (vehicle-left-side end surface) and an exhaust downstream end surface 43 b (vehicle-right-side end surface) of the catalyst installation portion 43 is located in substantially the same plane as that of a corresponding one of an exhaust upstream end surface and an exhaust downstream end surface of the casing 41 , or located slightly inward of the casing 41 .
- the catalyst is a three-way catalyst, it is designed particularly to purify HC and CO during warm-up of the engine 1 .
- the manifold catalytic converter 40 is provided in the upstream exhaust assembly 48 of the exhaust apparatus E. It is understood that the cross-sectional shape of the catalyst installation portion 43 is not limited to the generally circular shape.
- the manifold catalytic converter 40 is supported with respect to the vehicle-rear-side surface of the engine 1 .
- a protruding member 41 a is fixed to the casing 41 to protrude downwardly, and a support member 44 having a generally inverted-L shape when viewed from thereabove is provided between the protruding member 41 a and the vehicle-rear-side surface of the engine 1 , so that the manifold catalytic converter 40 is supported by the vehicle-rear-side surface of the engine 1 through the support member 44 .
- the support of the manifold catalytic converter 40 with respect to the engine 1 is not indispensable.
- the downstream exhaust pipe 51 is connected to the exhaust downstream end surface (vehicle-right-side end surface) of the casing 41 of the manifold catalytic converter 41 .
- the downstream exhaust pipe 51 is disposed to extend from a connection portion thereof with the manifold catalytic converter 40 (exhaust upstream end thereof), toward the tunnel opening 23 a formed in the vehicle-widthwise central region of the lower end of the dash panel 23 .
- the downstream exhaust pipe 51 curves toward the vehicle-rear side at the exhaust upstream end thereof and extends toward the vehicle-rear side.
- the downstream exhaust pipe 51 extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side (toward a vehicle-widthwise central region of the engine compartment 19 ). Then, when the downstream exhaust pipe 51 reaches a position in front of the tunnel opening 23 a, it extends toward the vehicle-rear side, and enters the tunnel portion 25 a from the tunnel opening 23 a.
- the downstream exhaust pipe 51 is comprised of a plurality of divided pipe members 52 formed by dividing the downstream exhaust pipe 51 into a plurality of pieces along a length direction thereof. Adjacent two of the pipe members 52 are connected together through two flanges 52 a formed at respective connection ends of the adjacent pipe members 52 . In FIGS.
- the exhaust downstream region of the single exhaust pipe portion 34 protrudes toward the vehicle-left side with respect to the exhaust upstream end surface 43 a of the catalyst installation portion 43 of the manifold catalytic converter 40 , and an exhaust upstream region of the downstream exhaust pipe 51 protrudes toward the vehicle-right side with respect to the exhaust downstream end surface 43 b of the catalyst installation portion 43 .
- a maximum vehicle-widthwise protruding amount of the single exhaust pipe portion 34 with respect to the exhaust upstream end surface 43 a of the catalyst installation portion 43 is set to be greater than a maximum vehicle-widthwise protruding amount of the downstream exhaust pipe 51 with respect to the exhaust downstream end surface 43 b of the catalyst installation portion 43 , to allow a gas entry angle with respect to the exhaust upstream end surface 43 a of the catalyst installation portion 43 (the gas entry angle means an acute one of two angles defined between a flow direction of exhaust gas entering the catalyst installation portion 43 from the single exhaust pipe portion 34 and the exhaust upstream end surface 43 a of the catalyst installation portion 43 ) to become greater than a gas discharge angle with respect to the exhaust downstream end surface 43 b of the catalyst installation portion 43 (the gas discharge angle means an acute one of two angles defined between the exhaust downstream end surface 43 b of the catalyst installation portion 43 and a flow direction of exhaust gas discharged from the catalyst installation portion 43 to the downstream exhaust pipe 51 ) (i.e., to allow the gas entry angle to become closer to
- the exhaust downstream region of the single exhaust pipe portion 34 is configured to reduce an inclination with respect to an extension direction of the casing 41 (catalyst installation portion 43 ) and largely extend in the extension direction of the casing 41 (catalyst installation portion 43 ), as compared with the exhaust upstream region of the downstream exhaust pipe 51 , to allow the gas entry angle with respect to the exhaust upstream end surface 43 a of the catalyst installation portion 43 to be set as close as possible to 90 degrees so as to cause exhaust gas entering the catalyst installation portion 43 to be uniformly dispersed over the entire cross-section of the catalyst installation portion 43 .
- the upstreammost pipe member 52 of the downstream exhaust pipe 51 has a flexible joint 53 .
- the flexible joint 53 is located inside the tunnel portion 25 a, and designed to absorb vibration of the engine 1 and vibration of the upstream exhaust assembly 48 caused by the vibration of the engine 1 so as to prevent the vibrations from being transmitted to a region on the exhaust downstream side of the flexible joint 53 .
- the number of the flexible joints 53 is not limited to one, but a plurality of the flexible joints 53 may be provided in series at intervals along the length direction of the downstream exhaust pipe 51 (see after-mentioned third and fourth embodiments).
- the upstreammost pipe member 52 is supported with respect to a vehicle body (floor panel 25 ) of the vehicle through a portion thereof located on the exhaust downstream side of the flexible joint 53 .
- an elongate rod-shaped support member 55 is bent into a generally trapezoidal shape, in top plan view.
- An upper side of the trapezoidal-shaped support member 55 is fixed to a vicinity of the flange 52 a of the upstreammost pipe member 52 .
- Each of opposite ends of a lower side of the trapezoidal-shaped support member 55 is formed to protrude outwardly in the vehicle-widthwise direction, and a distal end of each of the protruding portions is attached to the floor panel 25 through an elastic member 56 .
- the upstreammost pipe member 52 may be supported with respect to the vehicle body through a portion thereof located on the exhaust downstream side of a downstreammost one of the flexible joints 53 .
- the pipe member 52 immediately on the exhaust downstream side of the upstreammost pipe member 52 is provided with an underfoot catalytic converter 60 having a structure similar to that of the manifold catalytic converter 40 .
- a catalyst of the underfoot catalytic converter 60 is a three-way catalyst as with the manifold catalytic converter 40 , it is designed to primarily purify NOx.
- the pipe member 52 provided with the underfoot catalytic converter 60 is supported with respect to the vehicle body (floor panel 25 ) by a support structure similar to that for the upstreammost pipe member 52 .
- the branch pipe portions 32 , the intermediate collector pipe portions 33 , the single exhaust pipe portion 34 and the manifold catalytic converter 40 which constitute the upstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape turning in a clockwise direction toward the exhaust downstream side, in top plan view, so that the upstream exhaust assembly 48 including the manifold catalytic converter 40 can be compactly laid out on the vehicle-rear side of the engine 1 , while increasing a length of each of the branch pipe portions 32 and the intermediate collector pipe portions 33 to enhance exhaust efficiency.
- each of the intermediate collector pipe portions 33 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (vehicle-left side) which is a direction coming close to the transmission 11 , in top plan view, so that the single exhaust pipe portion 34 is disposed at a position closer to the transmission 11 than the branch pipe portions 32 .
- the upstream exhaust assembly 48 can be disposed away from auxiliary components (water pump, etc.) which are generally disposed on a surface of the engine 1 on an opposite side of the transmission 11 , and a vehicle-right-side sidewall of the engine compartment 19 (the side frame, etc.).
- the upstream exhaust assembly 48 formed in a loop shape brings an disadvantage in terms of exhaust resistance, as compared with a straight shape.
- a diameter of the loop can be set to a relatively large value by laying out the upstream exhaust assembly 48 in the above manner.
- a problem of the exhaust resistance practically does not occur, but it becomes possible to increase an output power of the engine 1 based on the exhaust efficiency-enhancing effect obtained by increasing the length of each of the branch pipe portions 32 and the intermediate collector pipe portions 33 .
- the manifold catalytic converter 40 is disposed adjacent to the vehicle-rear-side surface of the engine 1 , so that a traveling wind produced by traveling of the vehicle becomes less likely to touch the manifold catalytic converter 40 , which makes it possible to more quickly raise a temperature of the catalyst of the manifold catalytic converter 40 during warm-up of the engine 1 .
- the manifold catalytic converter 40 is disposed on the vehicle-front side of a connection position of each of the intermediate collector pipe portions 33 and the single exhaust pipe portion 34 (the exhaust upstream end of the single exhaust pipe portion 34 ) and below the branch pipe portions 32 .
- the manifold catalytic converter 40 having a large weight is disposed adjacent to the engine 1 , so that vibration of the upstream exhaust assembly 48 to be caused by vibration of the engine 1 can be reduced, as compared with an arrangement where the manifold catalytic converter 40 is disposed away from the engine 1 .
- the manifold catalytic converter 40 is supported with respect to the vehicle-rear-side surface of the engine 1 , so that the upstream exhaust assembly 48 can be stably supported to further reduce the vibration of the upstream exhaust assembly 48 to be caused by the vibration of the engine 1 .
- the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b are disposed offset with respect to each other in the vehicle-widthwise direction, so that it becomes possible to keep the branch pipe portions 32 from being located just above the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b .
- the exhaust upstream end of the single exhaust pipe portion 34 (the merging position of the first and second intermediate collector pipe portions 33 a, 33 b ) is also disposed offset with respect to the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b in the vehicle-widthwise direction, so that any component of the exhaust apparatus E is not located just above all of the exhaust upstream ends.
- FIGS. 6 to 8 show an exhaust apparatus E according to a second embodiment of the present invention, wherein a positional relationship between respective exhaust upstream ends of first and second intermediate collector pipe portions 33 a, 33 b (a merging position of first and fourth branch pipe portions 32 a, 32 d, and a merging position of second and third branch pipe portions 32 b, 32 c ) is defined differently from that in the first embodiment.
- the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b are disposed at approximately the same position as that of a third fastening point 37 c of a flange portion 36 in the vehicle-widthwise direction, and in offset relation to each other in an upward-downward direction.
- first branch pipe portion 32 a and the fourth branch portion 32 d are merged in the same manner as that in the first embodiment, whereas the second branch pipe portion 32 b and the third branch portion 32 c extend from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and then come close to each other so that they are merged together at approximately the same position as that of the third fastening point 37 c in the vehicle-widthwise direction.
- the exhaust upstream end of the first intermediate collector pipe portion 33 a is located just below the exhaust upstream end of the second intermediate collector pipe portion 33 b, i.e., the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b overlap each other, in top plan view.
- a height position of the exhaust upstream end of the first intermediate collector pipe portion 33 a is located below the third fastening point 37 c as with the first embodiment, whereas a height position of the exhaust upstream end of the second intermediate collector pipe portion 33 b is located above the third fastening point 37 c.
- the fastening operation at the third fastening point 37 c can be performed from the vehicle-rear side.
- the first and second intermediate collector pipe portions 33 a, 33 b are merged together while curving to allow respective exhaust downstream regions of the first and second intermediate collector pipe portions 33 a, 33 b to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11 ), in top plan view.
- the first and second intermediate collector pipe portions 33 a, 33 b extend from the respective exhaust upstream ends thereof toward the vehicle-rear side and then curve and extend toward the vehicle-left side, in overlapping relation to each other, in top plan view.
- first and second intermediate collector pipe portions 33 a, 33 b are merged together at approximately the same position as that of the fourth cylinder 2 d in the vehicle-widthwise direction, and a single exhaust pipe portion 34 is formed on the exhaust downstream side of the merging position.
- a configuration and an arrangement of each of a power plant 12 , the single exhaust pipe portion 34 , a manifold catalytic converter 40 and a downstream exhaust pipe 51 are the same as those in the first embodiment.
- a casing 41 gas passage
- a casing 41 is not inclined toward the vehicle-rear side as going toward the vehicle-left side, differently from the first embodiment.
- a maximum vehicle-widthwise protruding amount of the single exhaust pipe portion 34 with respect to an exhaust upstream end surface 43 a of a catalyst installation portion 43 is set to a value greater than that in the first embodiment, and thereby the gas entry angle with respect to the exhaust upstream end surface 43 a of the catalyst installation portion 43 can be set as close as possible to 90 degrees without inclining the casing 41 toward the vehicle-rear side as going toward the vehicle-left side.
- the branch pipe portions 32 , the intermediate collector pipe portions 33 , the single exhaust pipe portion 34 and the manifold catalytic converter 40 which constitute an upstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape, in top plan view, and each of the intermediate collector pipe portions 33 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side) which is a direction coming close to the transmission 11 , in top plan view, as with the first embodiment, so that the same functions/effects as those in the first embodiment can be obtained.
- first and second intermediate collector pipe portions 33 a, 33 b overlap each other, in top plan view, so that respective curvature radii of the first and second intermediate collector pipe portions 33 a, 33 b can be set to approximately the same and relatively large values, by effectively utilizing a space in an upward-downward direction.
- FIGS. 9 to 11 show an exhaust apparatus E according to a third embodiment of the present invention, wherein a positional relationship between respective exhaust upstream ends of first and second intermediate collector pipe portions 33 a, 33 b (a merging position of first and fourth branch pipe portions 32 a, 32 d, and a merging position of second and third branch pipe portions 32 b, 32 c ) is defined differently from those in the first and second embodiments.
- the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b are disposed at approximately the same position as that of a third fastening point 37 c of a flange portion 36 in the vehicle-widthwise direction, as with the second embodiment.
- the exhaust upstream ends of the first and second intermediate collector pipe portions 33 a, 33 b are offset with respect to each other in the vehicle-longitudinal direction, instead of overlapping each other, in top plan view.
- a length of each of the second and third branch pipe portions 32 b, 32 c in the vehicle-longitudinal direction is set to be greater than a length of each of the first and fourth branch pipe portions 32 a, 32 d in the vehicle-longitudinal direction, and the exhaust upstream end of the second intermediate collector pipe portion 33 b (the merging position of the second and third branch pipe portions 32 b, 32 c ) is located on the vehicle-rear side of the exhaust upstream end of the first intermediate collector pipe portion 33 a (the merging position of the first and fourth branch pipe portions 32 a, 32 d ).
- a height position of the exhaust upstream end of the second intermediate collector pipe portion 33 b is approximately equal to a height position of the exhaust upstream end of the first intermediate collector pipe portion 33 a, and located below the third fastening point 37 c. This makes it possible to keep an area around the third fastening point 37 c of the flange portion 36 and a region just above the area from overlapping the branch pipe portions 32 and the intermediate collector pipe portions 33 , as well as the remaining fastening points 37 ( 37 a, 37 b, 37 d, 37 e ), when viewed from the vehicle-rear side, as shown in FIG. 11 .
- the height position of the exhaust upstream end of the second intermediate collector pipe portion 33 b may be set in the same manner as that in the second embodiment, i.e., may be set to be located above the third fastening point 37 c. Even in this case, there is a possibility of being able to efficiently perform the operation of setting a fastening member in the area around the third fastening point 37 c from above the engine 1 , because the exhaust upstream end of the second intermediate collector pipe portion 33 b is located further toward the vehicle-rear side, as compared with the second embodiment. However, in view of enhancing the efficiency of the fastening operation, it is basically more preferable that the exhaust upstream end of the second intermediate collector pipe portion 33 b is set at a position below the third fastening point 37 c.
- the first and second intermediate collector pipe portions 33 a, 33 b are merged together while curving to allow respective exhaust downstream regions of the first and second intermediate collector pipe portions 33 a, 33 b to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11 ), in top plan view.
- the first intermediate collector pipe portion 33 a extends from the exhaust upstream end thereof toward the vehicle-rear side.
- the first intermediate collector pipe portion 33 a curves toward the vehicle-left side at a position just below the exhaust upstream end of the second intermediate collector pipe portion 33 b, and extends toward the vehicle-left side.
- the second intermediate collector pipe portion 33 b curves toward the vehicle-left side directly from the exhaust upstream end thereof, and extends toward the vehicle-left side while passing through a region on the vehicle-rear side of the first intermediate collector pipe portion 33 a. Then, the first and second intermediate collector pipe portions 33 a, 33 b are merged together at approximately the same position as that of the fourth cylinder 2 d in the vehicle-widthwise direction, to form a single exhaust pipe portion 34 .
- a configuration and an arrangement of each of a power plant 12 , the single exhaust pipe portion 34 and a manifold catalytic converter 40 are the same as those in the first or second embodiment.
- a downstream exhaust pipe 51 curves toward the vehicle-rear side at an exhaust upstream end thereof. Then, the downstream exhaust pipe 51 extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side (toward the vehicle-widthwise central region of the engine compartment 19 ), and enters the tunnel portion 25 a while maintaining the inclination. Then, the downstream exhaust pipe 51 is disposed to pass through a region of the tunnel portion 25 a on the vehicle-right side. Further, a support member 55 and an elastic member 56 are provided only on the vehicle-right side of the downstream exhaust pipe 51 .
- the above arrangement is intended to ensure a space (on the vehicle-left side) for allowing a drive shaft for driving rear wheels to pass therethrough, so as to make it possible to promptly change over to the vehicle into a four-wheel-drive vehicle, even if it is an FF vehicle.
- the drive shaft can be provided without modifying the downstream exhaust pipe 51 , the support member 55 , etc.
- an upstreammost one of a plurality of divided pipe members 52 of the downstream exhaust pipe 51 has two flexible joints 53 arranged in series at intervals along a length direction of the downstream exhaust pipe 51 (upstreammost pipe member 52 ).
- An exhaust downstream one of the flexible joints 53 is disposed inside the tunnel portion 25 a, whereas the other of exhaust upstream flexible joint 53 is disposed inside the engine compartment 19 .
- the branch pipe portions 32 , the intermediate collector pipe portions 33 , the single exhaust pipe portion 34 and the manifold catalytic converter 40 which constitute an upstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape, in top plan view, and each of the intermediate collector pipe portions 33 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side) which is a direction coming close to the transmission 11 , in top plan view, as with the first embodiment, so that the same functions/effects as those in the first embodiment can be obtained.
- FIGS. 12 to 14 show an exhaust apparatus E according to a fourth embodiment of the present invention, wherein an exhaust manifold 31 is configured such that the intermediate collector pipe portions 33 of in the first to third embodiments are eliminated, and four branch pipe portions 32 a , 32 b, 32 c, 32 d are merged together to form a single exhaust pipe portion 34 .
- the section in the fourth embodiment is comprised only of the branch pipe portions 32 .
- the single exhaust pipe portion 34 is formed by merging the four branch pipe portions 32 a to 32 d together, and directly communicated with the branch pipe portions 32 without an intermediary of the intermediate collector pipe portions 33 .
- Each of the branch pipe portions 32 curves to allow an exhaust downstream region of the branch pipe portion 32 to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11 ), in top plan view.
- each of the first and second branch pipe portions 32 a, 32 b extends from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and then curves to allow the exhaust downstream region thereof to one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11 ), in top plan view.
- each of the third and fourth branch pipe portions 32 c, 32 d extends from the vehicle-rear-side surface of the engine 1 toward the vehicle-rear side, and, shortly thereafter, extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side.
- each of the third and fourth branch pipe portions 32 c, 32 d curves toward one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11 ). Then, the four branch pipe portions 32 a to 32 d are merged together at an approximately the same vehicle-widthwise position as that of a fifth fastening point 37 e of a flange portion 36 to form a single exhaust pipe portion 34 .
- a configuration and an arrangement of each of a power plant 12 , the single exhaust pipe portion 34 , a manifold catalytic converter 40 and a downstream exhaust pipe 51 are the same as those in the third embodiment.
- the branch pipe portions 32 , the single exhaust pipe portion 34 and the manifold catalytic converter 40 which constitute an upstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape, in top plan view, and each of the branch pipe portions 32 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side) which is a direction coming close to the transmission 11 , in top plan view, as with the first embodiment, so that the same functions/effects as those in the first embodiment can be obtained.
- the number of cylinders of the engine 1 is not limited to four.
- the number of cylinders may be two or more.
- the number of cylinders may be four or more.
- the number of the intermediate collector pipe portions 33 may be increased to three or more, and the number of the branch pipe portions 32 to be merged to form one of the intermediate collector pipe portions 33 (i.e., the number of cylinders comprised in one of the cylinder groups) may be increased to three or more.
- the present invention is directed to an exhaust apparatus provided in an engine having a plurality of cylinders arranged in a line, wherein the engine is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction, and coupled with a transmission located on one side thereof in the cylinder arrangement direction.
- the exhaust apparatus comprises an upstream exhaust assembly connected to a surface of the engine on a vehicle-rear side, and a downstream exhaust pipe provided on an exhaust downstream side of the upstream exhaust assembly.
- the upstream exhaust assembly includes: a plurality of branch pipe portions communicated with respective ones of the plurality of cylinders and extending from the vehicle-rear-side surface of the engine toward the vehicle-rear side; a single exhaust pipe portion provided on the exhaust downstream side of the plurality of branch pipe portions in such a manner that it is communicated with the branch pipe portions; and an exhaust gas-purifying unit connected to an exhaust downstream end of the single exhaust pipe portion.
- the exhaust gas-purifying unit is disposed on the vehicle-rear side of the engine to allow a gas passage thereinside to extend approximately in the vehicle-widthwise direction, in top plan view.
- the upstream exhaust assembly includes, on an exhaust upstream side of the single exhaust pipe portion, a section which curves to allow an exhaust downstream region of the section to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view, and the single exhaust pipe portion curves to allow an exhaust downstream region of the single exhaust pipe portion to be oriented toward a vehicle-front side, in top plan view.
- the downstream exhaust pipe is connected to an exhaust downstream end of the exhaust gas-purifying unit, and disposed to extend from a connection portion thereof with the exhaust gas-purifying unit toward an tunnel opening formed in a vehicle-widthwise central region of a lower end of a dash panel of the vehicle.
- a section of the upstream exhaust assembly extending from the branch pipe portions to the exhaust gas-purifying unit is formed in a loop shape, in top plan view, so that the upstream exhaust assembly including the exhaust gas-purifying unit can be compactly laid out on the vehicle-rear side of the engine, while increasing a length of each of the branch pipe portions (or each of the branch pipe portions and a plurality of intermediate collector pipe portions) to enhance exhaust efficiency.
- the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view, so that the single exhaust pipe portion is disposed at a position closer to the transmission than the branch pipe portions.
- the upstream exhaust assembly can be disposed away from auxiliary components (water pump, etc.) which are generally disposed on a surface of the engine 1 on an opposite side of the transmission, and a sidewall of the engine compartment (a side frame, etc.).
- the upstream exhaust assembly formed in a loop shape brings an disadvantage in terms of exhaust resistance, as compared with a straight shape.
- a diameter of the loop can be set to a relatively large value by laying out the upstream exhaust assembly in the above manner.
- a problem of the exhaust resistance practically does not occur, but it becomes possible to increase an output power of the engine 1 based on the exhaust efficiency-enhancing effect obtained by increasing the length of each of the branch pipe portions (or each of the branch pipe portions and the intermediate collector pipe portions).
- the upstream exhaust assembly formed in a loop shape makes it possible to distribute an elongation of the upstream exhaust assembly caused by thermal expansion, over the entire loop, so as to prevent degradation of the upstream exhaust assembly due to stress concentration.
- the exhaust gas-purifying unit can be disposed adjacent to the vehicle-rear-side surface of the engine, so that a traveling wind produced by traveling of the vehicle becomes less likely to touch the exhaust gas-purifying unit, which makes it possible to more quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during warm-up of the engine.
- the exhaust gas-purifying unit having a large weight is disposed adjacent to the engine, so that vibration of the upstream exhaust assembly to be caused by vibration of the engine can be reduced, as compared with an arrangement where the exhaust gas-purifying unit is disposed away from the engine.
- the transverse engine exhaust apparatus of the present invention make it possible to compactly lay out the upstream exhaust assembly thereof including the exhaust gas-purifying unit, in the engine compartment without sacrificing a passenger compartment space, and quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during engine warm-up.
- an elongation of the upstream exhaust assembly caused by thermal expansion can be distributed, and vibration of the upstream exhaust assembly to be caused by vibration of the engine can be reduced.
- an influence of radiant heat on auxiliary components and a sidewall of the engine compartment can be suppressed.
- the exhaust gas-purifying unit has a catalyst installation portion formed in a cross-sectionally generally circular shape and provided in the gas passage, and a maximum vehicle-widthwise protruding amount of the single exhaust pipe portion with respect to an exhaust upstream end surface of the catalyst installation portion is set to be greater than a maximum vehicle-widthwise protruding amount of the downstream exhaust pipe with respect to an exhaust downstream end surface of the catalyst installation portion, to allow a gas entry angle with respect to the exhaust upstream end surface of the catalyst installation portion to become greater than a gas discharge angle with respect to the exhaust downstream end surface of the catalyst installation portion.
- exhaust gas entering the exhaust upstream end surface of the catalyst installation portion becomes more likely to be uniformly dispersed over the entire cross-section of the catalyst installation portion, to allow a catalyst of the exhaust gas-purifying unit to more efficiently purify exhaust gas.
- the exhaust upstream end surface (the connection portion with the single exhaust pipe portion) of the catalyst installation portion is located closer to the transmission than the exhaust downstream end surface thereof, so that components and members interferable with the single exhaust pipe portion can be limited to a relatively small member, which makes it easy to increase the maximum vehicle-widthwise protruding amount of the single exhaust pipe portion with respect to the exhaust upstream end surface.
- the exhaust gas-purifying unit is disposed on the vehicle-front side of an exhaust upstream end of the single exhaust pipe portion and below the branch pipe portions.
- the exhaust gas-purifying unit can be disposed closer to the engine, so that it becomes possible to further reduce vibration of the upstream exhaust assembly to be caused by vibration of the engine.
- the exhaust gas-purifying unit is supported with respect to the engine, and the downstream exhaust pipe has a flexible joint interposed therein.
- the upstream exhaust assembly including the exhaust gas-purifying unit can be stably supported to further reduce the vibration of the exhaust upstream section to be caused by the vibration of the engine.
- a region of the exhaust apparatus upstream of the flexible joint vibrates together with the engine, the vibration is absorbed by the flexible joint, so that it becomes possible to prevent the vibration from being transmitted to a region located on the exhaust downstream side of the flexible joint (and typically fixed to a vehicle body of the vehicle).
- the upstream exhaust assembly has a plurality of intermediate collector pipe portions between each of the plurality of branch pipe portions and the single exhaust pipe portion, wherein each of the intermediate collector pipe portions is formed by dividing the plurality of cylinders into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other, and merging the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups, on a cylinder group-by-cylinder group basis, and wherein the single exhaust pipe portion is formed by merging the plurality of intermediate collector pipe portions together, and each of the plurality of intermediate collector pipe portions curves to allow an exhaust downstream region of the intermediate collector pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
- the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion is comprised of the branch pipe portions, wherein the single exhaust pipe portion is formed by merging the plurality of branch pipe portions together, and each of the plurality of branch pipe portions curves to allow an exhaust downstream region of the branch pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
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Abstract
Disclosed is an exhaust apparatus (E) for a transverse engine (1) coupled with a transmission (11) located on one side thereof in a cylinder arrangement direction. The exhaust apparatus (E) has an upstream exhaust assembly (48) which comprises a plurality of branch pipe portions (32), a single exhaust pipe portion (34), and an exhaust gas-purifying unit (40). The exhaust gas-purifying unit (40) is disposed on a vehicle-rear side of the engine (1) to allow a gas passage thereinside to extend approximately in a vehicle-widthwise direction, in top plan view. The upstream exhaust assembly (48) includes, on an exhaust upstream side of the single exhaust pipe portion (34), a section which curves to allow an exhaust downstream region of the section to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission (11), in top plan view. The single exhaust pipe portion (34) curves to allow an exhaust downstream region of the single exhaust pipe portion (34) to be oriented toward a vehicle-front side, in top plan view. This makes it possible to compactly lay out the upstream exhaust assembly (48) in an engine compartment (19) without sacrificing a passenger compartment space, and quickly raise a temperature of a catalyst in the exhaust gas-purifying unit (40) during warm-up of the engine (1).
Description
- 1. Field of the Invention
- The present invention belongs to a technical field relating to an exhaust apparatus for a transverse engine which is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a widthwise direction of the vehicle (vehicle-widthwise direction).
- 2. Description of the Background Art
- Heretofore, this type of transverse engine has been widely known. Typically, an exhaust apparatus for the transverse engine is disposed on a vehicle-rear side of the engine (see, for example, JP 2008-260472A; this document will hereinafter be referred to as “
Patent Document 1”). The exhaust apparatus has a plurality of branch pipe portions each communicated with a respective one of a plurality of cylinders of the engine, wherein the branch pipe portions are merged to finally form a single exhaust pipe portion. Specifically, in thePatent Document 1, the entire cylinders (four cylinders) are divided into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other (a cylinder group consisting of the first (#1) and fourth (#4) cylinders, and a cylinder group consisting of the second (#2) and third (#3) cylinders), and the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups are merged on a cylinder group-by-cylinder group basis to form a plurality of (two) intermediate collector pipe portions. Then, the two intermediate collector pipe portions are merged together to form a single exhaust pipe portion. In some cases, all of the branch pipe portions are merged together to form a single collector pipe portion, without providing the intermediate collector pipe portions. - In late years, with a view to reducing exhaust gas emissions during engine warm-up (when an engine is in a cold start mode), an exhaust gas-purifying unit has been provided on a relatively upstream side of an exhaust gas stream to quickly raise a temperature of a catalyst in the exhaust gas-purifying unit. In the
Patent Document 1, an exhaust gas-purifying unit (manifold catalytic converter) is provided in each of the intermediate collector pipe portions. - Meanwhile, in view of enhancing engine exhaust efficiency to increase engine output power, it is desirable to maximize a length of each of the branch pipe portions and the intermediate collector pipe portions (in an exhaust apparatus provided with no intermediate collector pipe portion, to maximize a length of each of the branch pipe portions). From this viewpoint, the exhaust apparatus in the
Patent Document 1 is also designed to increase a length of each of the branch pipe portions and the intermediate collector pipe portions. For this purpose, the two intermediate collector pipe portions are disposed inside a tunnel portion formed in a vehicle-widthwise central region of a floor panel. - However, in order to allow the two intermediate collector pipe portions to be disposed inside the tunnel portion, it is necessary to increase width and height dimensions (cross-sectional area) of the tunnel portion. Particularly, in the
Patent Document 1, due to the exhaust gas-purifying units provided in the intermediate collector pipe portions, the cross-sectional area of the tunnel portion needs to be further increased. Thus, there remains the need for improvement in view of ensuring a passenger compartment space as widely as possible. Moreover, in the arrangement where the exhaust gas-purifying unit is provided inside the tunnel portion, a traveling wind produced by traveling of a vehicle is more likely to touch the exhaust gas-purifying unit, so that it becomes difficult to quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during engine warm-up. In this regard, there also remains the need for improvement. - The present invention has been made in view of the above background art. It is therefore an object of the present invention to, in an exhaust apparatus for a transverse engine, make it possible to compactly lay out an upstream exhaust assembly thereof including an exhaust gas-purifying unit, in an engine compartment without sacrificing a passenger compartment space, and quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during engine warm-up.
- In order to achieve the above object, the present invention is directed to an exhaust apparatus provided in an engine having a plurality of cylinders arranged in a line, wherein the engine is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction, and coupled with a transmission located on one side thereof in the cylinder arrangement direction. The exhaust apparatus comprises an upstream exhaust assembly connected to a surface of the engine on a vehicle-rear side, and a downstream exhaust pipe provided on an exhaust downstream side of the upstream exhaust assembly. The upstream exhaust assembly includes: a plurality of branch pipe portions communicated with respective ones of the plurality of cylinders and extending from the vehicle-rear-side surface of the engine toward the vehicle-rear side; a single exhaust pipe portion provided on the exhaust downstream side of the plurality of branch pipe portions in such a manner that it is communicated with the branch pipe portions; and an exhaust gas-purifying unit connected to an exhaust downstream end of the single exhaust pipe portion. The exhaust gas-purifying unit is disposed on the vehicle-rear side of the engine to allow a gas passage thereinside to extend approximately in the vehicle-widthwise direction, in top plan view. The upstream exhaust assembly includes, on an exhaust upstream side of the single exhaust pipe portion, a section which curves to allow an exhaust downstream region of the section to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view. The single exhaust pipe portion curves to allow an exhaust downstream region of the single exhaust pipe portion to be oriented toward a vehicle-front side, in top plan view. The downstream exhaust pipe is connected to an exhaust downstream end of the exhaust gas-purifying unit, and disposed to extend from a connection portion thereof with the exhaust gas-purifying unit toward an tunnel opening formed in a vehicle-widthwise central region of a lower end of a dash panel of the vehicle.
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FIG. 1 is a top plan view showing a mounted state of an exhaust apparatus according to a first embodiment of the present invention, with respect to a vehicle. -
FIG. 2 is a side view showing the mounted state of the exhaust apparatus with respect to the vehicle, when viewed from a left side of the vehicle. -
FIG. 3 is a top plan view showing an upstream exhaust assembly, and an upstreammost one of a plurality of divided pipe members of a downstream exhaust pipe, in the exhaust apparatus. -
FIG. 4 is a side view showing the upstream exhaust assembly, and the upstreammost pipe member of the downstream exhaust pipe, in the exhaust apparatus, when viewed from the left side of the vehicle. -
FIG. 5 is a view showing the upstream exhaust assembly, and the upstreammost pipe member of the downstream exhaust pipe, in the exhaust apparatus, when viewed from a rear side of the vehicle. -
FIG. 6 is a view corresponding toFIG. 3 , illustrating a second embodiment of the present invention. -
FIG. 7 is a view corresponding toFIG. 4 , illustrating the second embodiment. -
FIG. 8 is a view corresponding toFIG. 5 , illustrating the second embodiment. -
FIG. 9 is a view corresponding toFIG. 3 , illustrating a third embodiment of the present invention. -
FIG. 10 is a view corresponding toFIG. 4 , illustrating the third embodiment. -
FIG. 11 is a view corresponding toFIG. 5 , illustrating the third embodiment. -
FIG. 12 is a view corresponding toFIG. 3 , illustrating a fourth embodiment of the present invention. -
FIG. 13 is a view corresponding toFIG. 4 , illustrating the fourth embodiment. -
FIG. 14 is a view corresponding toFIG. 5 , illustrating the fourth embodiment. - The present invention will now be specifically described based on embodiments thereof.
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FIGS. 1 and 2 show an exhaust apparatus E according to a first embodiment of the present invention. The exhaust apparatus E is designed for atransverse engine 1. Theengine 1 is an inline four-cylinder engine having fourcylinders 2 arranged in a line, and transversely placed in anengine compartment 19 at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction (rightward-leftward direction inFIG. 1 ). In the following description, a right side of the vehicle which corresponds to a right side inFIG. 1 (reverse side of the drawing sheet ofFIG. 2 ), a left side of the vehicle which corresponds to a left side inFIG. 1 (obverse side of the drawing sheet ofFIG. 2 ), a front side of the vehicle which corresponds to an upper side inFIG. 1 (left side inFIG. 2 ), and a rear side of the vehicle which corresponds to a lower side inFIG. 1 (right side inFIG. 2 ), will be referred to respectively as “vehicle-right side”, “vehicle-left side”, “vehicle-front side”, and “vehicle-rear side”. - The
engine 1 is disposed offset toward a vehicle-right side (right side inFIG. 1 ) in theengine compartment 19. Further, theengine 1 is disposed in an inclined posture to allow an axis of each of thecylinders 2 to be oriented upwardly and toward a vehicle-rear side. - The
engine 1 is coupled with atransmission 11 located on one side thereof in the cylinder arrangement direction (in the first embodiment, on a vehicle-left side (left side inFIG. 1 )). A combination of theengine 1 and thetransmission 11 makes up apower plant 12. Thetransmission 11 is a transverse type having a non-illustrated input shaft and a non-illustrated output shaft each extending in the vehicle-widthwise direction. The input shaft is coupled to a crankshaft of theengine 1 extending in the vehicle-widthwise direction, and the output shaft is coupled to adifferential gear mechanism 14 disposed on the vehicle-rear side of thetransmission 11. Although not illustrated, right and left front wheel drive axles each coupled to a corresponding one of right and left front wheels extend from thedifferential gear mechanism 14 toward respective ones of opposite sides of the vehicle-widthwise direction. The vehicle is an FF (front engine, front wheel drive) vehicle in which the right and left front wheels are driven by theengine 1. It is understood that the vehicle may be a four-wheel-drive vehicle. - A
left side frame 21 and aright side frame 22 are provided on respective ones of opposite sides of thepower plant 12 in the vehicle-widthwise direction. - Specifically, the
left side frame 21 and theright side frame 22 are disposed on a left side close to thetransmission 11 and on a right side close to theengine 1, respectively, to extend in an frontward-rearward direction of the vehicle (vehicle-longitudinal direction). - A vehicle-rear-side wall of the
engine compartment 19 is made up of adash panel 23 partitioning between theengine compartment 19 and apassenger compartment 20. Thedash panel 23 extends in an upward-downward direction and in the vehicle-widthwise direction. An upper end of thedash panel 23 is joined to acowl member 24, and a lower end of thedash panel 23 is joined to a front end of afloor panel 25 defining a floor surface of thepassenger compartment 20. - The
floor panel 25 has atunnel portion 25 a formed in a vehicle-widthwise central region thereof to bulge upwardly in a cross-sectionally generally inverted-U shape and extend in the vehicle-longitudinal direction. Thedash panel 23 has a tunnel opening 23 a which is a upwardly-extending cutout formed in a vehicle-widthwise central region of the lower end thereof to communicate with thetunnel portion 25 a. Thus, a single exhaust pipe (after-mentioned downstream exhaust pipe 51) will pass through an inner space of thetunnel portion 25 a (outside of the passenger compartment 20). When the vehicle is a four-wheel-drive vehicle, an exhaust pipe and a drive shaft for driving rear wheels will pass through the inner space of thetunnel portion 25 a. - An
intake manifold 4 is provided on a vehicle-front side of theengine 1 to introduce intake air into each of thecylinders 2 of theengine 1. Theintake manifold 4 has fourbranch pipe portions cylinders 2 of theengine 1 and opened on a vehicle-front-side surface of theengine 1. Thebranch pipe portions 4 a to 4 d are curvedly formed to surround asurge tank 5 extending in the cylinder arrangement direction (vehicle-widthwise direction). - The exhaust apparatus E is provided on the vehicle-rear side of the
engine 1 to discharge exhaust gas produced in each of thecylinders 2 of theengine 1. With reference toFIGS. 3 to 5 , details of the exhaust apparatus E will be specifically described below. - The exhaust apparatus E comprises an
exhaust manifold 31, a manifoldcatalytic converter 40 as a unit for purifying exhaust gas of the engine 1 (exhaust gas-purifying unit), and adownstream exhaust pipe 51, which are arranged in this order from an exhaust upstream side (upstream side of an exhaust gas stream). A combination of theexhaust manifold 31 and the manifoldcatalytic converter 40 makes up anupstream exhaust assembly 48 of the exhaust apparatus E. Theupstream exhaust assembly 48 is housed in theengine compartment 19. - The
exhaust manifold 31 includes fourbranch pipe portions 32 communicated with respective ones of the fourcylinders 2 of theengine 1, two intermediatecollector pipe portions 33 each formed by merging two of the fourbranch pipe portions 32 together, and one singleexhaust pipe portion 34 formed by merging the two intermediatecollector pipe portions 33 together. The manifoldcatalytic converter 40 is connected to an exhaust downstream end of the singleexhaust pipe portion 34. - In the following description, the four
cylinders 2 will be referred to respectively as “first cylinder 2 a”, “second cylinder 2 b”, “third cylinder 2 c” and “fourth cylinder 2 d”, in order from the side opposite to the transmission 11 (vehicle-right side) toward the transmission 11 (vehicle-left side). When it is not necessary to distinguish between them in this manner, they will be referred to simply as “cylinders 2” on a case-by-case basis. Further, thebranch pipe portions 32 communicated with respective ones of the first tofourth cylinders 2 a to 2 d will be referred to respectively as “firstbranch pipe portion 32 a”, “secondbranch pipe portion 32 b”, “thirdbranch pipe portion 32 c” and “forthbranch pipe portion 32 d”. When it is not necessary to distinguish between them in this manner, they will be referred to simply as “branch pipe portions 32” on a case-by-case basis. - An exhaust upstream end of each of the first to fourth
branch pipe portions 32 a to 32 d is connected to a surface of theengine 1 on a vehicle-rear side through aflange portion 36 provided to be shared by all of thebranch pipe portions 32 a to 32 d and extending in the vehicle-widthwise direction. Specifically, theflange portion 36 is attached to the vehicle-rear-side surface of theengine 1 to allow the exhaust upstream ends of the first to fourthbranch pipe portions 32 a to 32 d to be connected to respective ones of four exhaust ports (not shown) opened on the vehicle-rear-side surface of theengine 1, through theflange portion 36, so that the first to fourthbranch pipe portions 32 a to 32 d are communicated with respective ones of the first tofourth cylinders 2 a to 2 d. - The
flange portion 36 has a plurality of (in the first embodiment, five) fastening points 37 each adapted to be fastened to the vehicle-rear-side surface of theengine 1 by a fastening member such as a bolt. Each of the fastening points 37 is formed as a through-hole for allowing the fastening member such as a bolt to be inserted thereinto. In the following description, the fivefastening points 37 will be referred to respectively as “first fastening point 37 a”, “second fastening point 37 b”, “third fastening point 37 c”, “fourth fastening point 37 d” and “fifth fastening point 37 e”, in order from the vehicle-right side. When it is not necessary to distinguish between them in this manner, they will be referred to simply as “fastening points 37” on a case-by-case basis. - The
first fastening point 37 a is provided in theflange portion 36 at a position corresponding to a region on a vehicle-widthwise outer side (vehicle-right side) of thefirst cylinder 2 a. Thesecond fastening point 37 b is provided in theflange portion 36 at a position corresponding to a region between thefirst cylinder 2 a and thesecond cylinder 2 b, and thethird fastening point 37 c is provided in theflange portion 36 at a position corresponding to a region between thesecond cylinder 2 b and thethird cylinder 2 c. Thefourth fastening point 37 d is provided in theflange portion 36 at a position corresponding to a region between thethird cylinder 2 c and thefourth cylinder 2 d, and thefifth fastening point 37 e is provided in theflange portion 36 at a position corresponding to a region on a vehicle-widthwise outer side (vehicle-left side) of thefourth cylinder 2 d. The first to fifth fastening points 37 a to 37 e are arranged such that two lines each connecting a part of the fastening points extend in the vehicle-widthwise direction (cylinder arrangement direction) in spaced-apart relation to each other in a heightwise direction. The upper fastening point line including the second and fourth fastening points 37 b, 37 d is located at a first height position adjacent to an upper edge of theflange portion 36, and the lower fastening point line including the first, third and fifth fastening points 37 a, 37 c, 37 e is located at a second height position adjacent to a lower edge of theflange portion 36. Thus, each of the second and fourth fastening points 37 b, 37 d corresponds to a high-position fastening point provided at the first height position, and each of the first, third and fifth fastening points 37 a, 37 c, 37 e corresponds to a low-position fastening point provided at the second height position below the first height position. Further, the first to fifth fastening points 37 a to 37 e are arranged in a zigzag pattern to allow each of the fastening points 37 on the upper line to be located in a corresponding one of two regions between adjacent ones of the fastening points 37 on the lower line. - Each of the intermediate
collector pipe portions 33 is formed by dividing the fourcylinders 2 into two cylinder groups each consisting of twocylinders 2 whose exhaust strokes (expansion strokes) are not successive with respect to each other, and merging thebranch pipe portions 32 communicated with respective ones of the twocylinders 2 in each of the cylinder groups, on a cylinder group-by-cylinder group basis. In the first embodiment, the exhaust stroke occurs in the following order: thefirst cylinder 2 a→thethird cylinder 2 c→thefourth cylinder 2 d→thesecond cylinder 2 b. Thus, the fourcylinders 2 are divided into a cylinder group consisting of thefirst cylinder 2 a and thefourth cylinder 2 d, and a cylinder group consisting of thesecond cylinder 2 b and thethird cylinder 2 c. Then, the first and fourthbranch pipe portions fourth cylinders collector pipe portions 33, and the second and thirdbranch pipe portions third cylinders collector pipe portion 33. In the following description, the intermediatecollector pipe portion 33 formed by merging the first and fourthbranch pipe portions collector pipe portion 33 a”, and the intermediatecollector pipe portion 33 formed by merging the second and thirdbranch pipe portions collector pipe portion 33 b” When it is not necessary to distinguish between them in this manner, they will be referred to simply as “intermediatecollector pipe portions 33” on a case-by-case basis. - Each of the first to fourth
branch pipe portions 32 a to 32 d extends from the vehicle-rear-side surface of the engine 1 (in a strict sense, from the flange portion 36), basically toward the vehicle-rear side. More specifically, in top plan view, the firstbranch pipe portion 32 a extends from the vehicle-rear-side surface of theengine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side. In top plan view, the fourthbranch pipe portion 32 d extends from the vehicle-rear-side surface of theengine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side. Then, the firstbranch pipe portion 32 a and the fourthbranch pipe portion 32 d are merged together at approximately the same vehicle-widthwise position as that of thethird fastening point 37 c, and the first intermediatecollector pipe portion 33 a is formed on an exhaust downstream side of the merging position. Further, in top plan view, the secondbranch pipe portion 32 b extends from the vehicle-rear-side surface of theengine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side. Then, just before the second intermediatecollector pipe portion 33 b, the secondbranch pipe portion 32 b curves toward the opposite side and extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side. In top plan view, the thirdbranch pipe portion 32 c extends from the vehicle-rear-side surface of theengine 1 toward the vehicle-rear side, and then extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side. Then, the secondbranch pipe portion 32 b and the thirdbranch pipe portion 32 c are merged together at approximately the same vehicle-widthwise position as that of thesecond fastening point 37 b, and the second intermediatecollector pipe portion 33 b is formed on the exhaust downstream side of the merging position. Each of the second and thirdbranch pipe portions branch pipe portion 32 a, while passing across a region just below the firstbranch pipe portion 32 a. - In the first embodiment, respective exhaust upstream ends of the first and second intermediate
collector pipe portions branch pipe portions branch pipe portions collector pipe portion 33 a (the merging position of the first and fourthbranch pipe portions transmission 11 with respect to) an exhaust upstream end of the second intermediatecollector pipe portion 33 b (the merging position of the second and thirdbranch pipe portions collector pipe portion 33 a is approximately equal to a height position of the exhaust upstream end of the second intermediatecollector pipe portion 33 b (in a strict sense, slightly above a height position of the exhaust upstream end of the second intermediatecollector pipe portion 33 b), and located below thethird fastening point 37 c. This arrangement makes it possible to keep an area around each of the fastening points 37 (particularly, thethird fastening point 37 c) of theflange portion 36 and a region just above the area from overlapping thebranch pipe portions 32 and the intermediatecollector pipe portions 33, when viewed from the vehicle-rear side, as shown inFIG. 5 . Thus, a space for a fastening operation at each of the fastening points 37 (particularly, thethird fastening point 37 c) can be ensured to allow a fastening member to be set in each area around the fastening points 37 from above theengine 1, which makes it easy to perform the fastening operation. - The first and second intermediate
collector pipe portions collector pipe portions exhaust pipe portion 34 is formed on the exhaust downstream side of the merging position of the first and second intermediatecollector pipe portions collector pipe portion 33 a extends from the exhaust upstream end thereof toward the vehicle-rear side, and then curves toward the vehicle-left side, and the second intermediatecollector pipe portion 33 b curves toward the vehicle-left side directly from the exhaust upstream end thereof, and extends toward the vehicle-left side while passing across a region just below the exhaust upstream end of the first intermediatecollector pipe portion 33 a. Then, the first and second intermediatecollector pipe portions exhaust pipe portion 34. In this manner, the singleexhaust pipe portion 34 is provided on the exhaust downstream side of thebranch pipe portions 32, and communicated with the fourbranch pipe portions 32 a to 32 d via the first and second intermediatecollector pipe portions - The single
exhaust pipe portion 34 is connected to the manifoldcatalytic converter 40 while curving to allow an exhaust downstream region of the singleexhaust pipe portion 34 to be oriented toward the vehicle-front side, in top plan view. The exhaust downstream region of the singleexhaust pipe portion 34 curves toward the vehicle-front side with an inclination toward the vehicle-right side, and the singleexhaust pipe portion 34 has an intermediate region formed in a curved shape which is convexed toward a side opposite to the manifold catalytic converter 40 (toward the vehicle-left side) with respect to both ends of the singleexhaust pipe portion 34. The exhaust downstream end of the singleexhaust pipe portion 34 is increased in diameter to have the same diameter as that of an after-mentionedcasing 41 of the manifoldcatalytic converter 40, and connected to an exhaust upstream end surface of the casing 41 (a left end surface of thecasing 41 on the vehicle-left side). - The manifold
catalytic converter 40 is disposed on the vehicle-rear side of theengine 1, and disposed to allow a gas passage inside thecasing 41 to extend approximately in the vehicle-widthwise direction, in top plan view. Thus, thecasing 41 extends approximately along the vehicle-rear-side surface of theengine 1. In the first embodiment, in a strict sense, the casing 41 (gas passage) is inclined to be gradually shifted toward the vehicle-rear side by a slight distance as going toward the vehicle-left side (exhaust upstream side). This is intended to allow a gas entry angle with respect to an exhaustupstream end surface 43 a of acatalyst installation portion 43 to be set as close as possible to 90 degrees, as described later. Further, the casing 41 (gas passage) is inclined to be gradually shifted downwardly by a slight distance as going toward the vehicle-right side (exhaust downstream side). This is because thedownstream exhaust pipe 51 is located just below the second and thirdbranch pipe portions collector pipe portion 33 b, i.e., intended to avoid interference with these portions (32 b, 32 c, 33 b). - The manifold
catalytic converter 40 is formed by installing a catalyst in a gas passage inside an generally cylindrical-shapedcasing 41. Acatalyst installation portion 43 in the gas passage inside thecasing 41 has a generally circular shape in cross-section. Each of an exhaustupstream end surface 43 a (vehicle-left-side end surface) and an exhaustdownstream end surface 43 b (vehicle-right-side end surface) of thecatalyst installation portion 43 is located in substantially the same plane as that of a corresponding one of an exhaust upstream end surface and an exhaust downstream end surface of thecasing 41, or located slightly inward of thecasing 41. Although the catalyst is a three-way catalyst, it is designed particularly to purify HC and CO during warm-up of theengine 1. For this purpose, the manifoldcatalytic converter 40 is provided in theupstream exhaust assembly 48 of the exhaust apparatus E. It is understood that the cross-sectional shape of thecatalyst installation portion 43 is not limited to the generally circular shape. - In the first embodiment, the manifold
catalytic converter 40 is supported with respect to the vehicle-rear-side surface of theengine 1. Specifically, a protrudingmember 41 a is fixed to thecasing 41 to protrude downwardly, and asupport member 44 having a generally inverted-L shape when viewed from thereabove is provided between the protrudingmember 41 a and the vehicle-rear-side surface of theengine 1, so that the manifoldcatalytic converter 40 is supported by the vehicle-rear-side surface of theengine 1 through thesupport member 44. The support of the manifoldcatalytic converter 40 with respect to theengine 1 is not indispensable. - The
downstream exhaust pipe 51 is connected to the exhaust downstream end surface (vehicle-right-side end surface) of thecasing 41 of the manifoldcatalytic converter 41. Thedownstream exhaust pipe 51 is disposed to extend from a connection portion thereof with the manifold catalytic converter 40 (exhaust upstream end thereof), toward the tunnel opening 23 a formed in the vehicle-widthwise central region of the lower end of thedash panel 23. Specifically, in top plan view, thedownstream exhaust pipe 51 curves toward the vehicle-rear side at the exhaust upstream end thereof and extends toward the vehicle-rear side. Then, thedownstream exhaust pipe 51 extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side (toward a vehicle-widthwise central region of the engine compartment 19). Then, when thedownstream exhaust pipe 51 reaches a position in front of the tunnel opening 23 a, it extends toward the vehicle-rear side, and enters thetunnel portion 25 a from the tunnel opening 23 a. Thedownstream exhaust pipe 51 is comprised of a plurality of dividedpipe members 52 formed by dividing thedownstream exhaust pipe 51 into a plurality of pieces along a length direction thereof. Adjacent two of thepipe members 52 are connected together through twoflanges 52 a formed at respective connection ends of theadjacent pipe members 52. InFIGS. 1 and 2 , only an upstreammost one of thepipe members 52 and a part of thepipe member 52 located immediately on the exhaust downstream side of theupstreammost pipe member 52 are illustrated, and the illustration of the remainingpipe members 52 is omitted. Further, inFIGS. 3 to 5 , only theupstreammost pipe member 52 is illustrated. - The exhaust downstream region of the single
exhaust pipe portion 34 protrudes toward the vehicle-left side with respect to the exhaustupstream end surface 43 a of thecatalyst installation portion 43 of the manifoldcatalytic converter 40, and an exhaust upstream region of thedownstream exhaust pipe 51 protrudes toward the vehicle-right side with respect to the exhaustdownstream end surface 43 b of thecatalyst installation portion 43. Further, a maximum vehicle-widthwise protruding amount of the singleexhaust pipe portion 34 with respect to the exhaustupstream end surface 43 a of thecatalyst installation portion 43 is set to be greater than a maximum vehicle-widthwise protruding amount of thedownstream exhaust pipe 51 with respect to the exhaustdownstream end surface 43 b of thecatalyst installation portion 43, to allow a gas entry angle with respect to the exhaustupstream end surface 43 a of the catalyst installation portion 43 (the gas entry angle means an acute one of two angles defined between a flow direction of exhaust gas entering thecatalyst installation portion 43 from the singleexhaust pipe portion 34 and the exhaustupstream end surface 43 a of the catalyst installation portion 43) to become greater than a gas discharge angle with respect to the exhaustdownstream end surface 43 b of the catalyst installation portion 43 (the gas discharge angle means an acute one of two angles defined between the exhaustdownstream end surface 43 b of thecatalyst installation portion 43 and a flow direction of exhaust gas discharged from thecatalyst installation portion 43 to the downstream exhaust pipe 51) (i.e., to allow the gas entry angle to become closer to 90 degree as compared with the gas discharge angle). Specifically, the exhaust downstream region of the singleexhaust pipe portion 34 is configured to reduce an inclination with respect to an extension direction of the casing 41 (catalyst installation portion 43) and largely extend in the extension direction of the casing 41 (catalyst installation portion 43), as compared with the exhaust upstream region of thedownstream exhaust pipe 51, to allow the gas entry angle with respect to the exhaustupstream end surface 43 a of thecatalyst installation portion 43 to be set as close as possible to 90 degrees so as to cause exhaust gas entering thecatalyst installation portion 43 to be uniformly dispersed over the entire cross-section of thecatalyst installation portion 43. - The
upstreammost pipe member 52 of thedownstream exhaust pipe 51 has a flexible joint 53. The flexible joint 53 is located inside thetunnel portion 25 a, and designed to absorb vibration of theengine 1 and vibration of theupstream exhaust assembly 48 caused by the vibration of theengine 1 so as to prevent the vibrations from being transmitted to a region on the exhaust downstream side of the flexible joint 53. The number of theflexible joints 53 is not limited to one, but a plurality of theflexible joints 53 may be provided in series at intervals along the length direction of the downstream exhaust pipe 51 (see after-mentioned third and fourth embodiments). - The
upstreammost pipe member 52 is supported with respect to a vehicle body (floor panel 25) of the vehicle through a portion thereof located on the exhaust downstream side of the flexible joint 53. Specifically, an elongate rod-shapedsupport member 55 is bent into a generally trapezoidal shape, in top plan view. An upper side of the trapezoidal-shapedsupport member 55 is fixed to a vicinity of theflange 52 a of theupstreammost pipe member 52. Each of opposite ends of a lower side of the trapezoidal-shapedsupport member 55 is formed to protrude outwardly in the vehicle-widthwise direction, and a distal end of each of the protruding portions is attached to thefloor panel 25 through anelastic member 56. In cases where a plurality of theflexible joints 53 are provided in theupstreammost pipe member 52, theupstreammost pipe member 52 may be supported with respect to the vehicle body through a portion thereof located on the exhaust downstream side of a downstreammost one of the flexible joints 53. - The
pipe member 52 immediately on the exhaust downstream side of theupstreammost pipe member 52 is provided with an underfootcatalytic converter 60 having a structure similar to that of the manifoldcatalytic converter 40. Although a catalyst of the underfootcatalytic converter 60 is a three-way catalyst as with the manifoldcatalytic converter 40, it is designed to primarily purify NOx. Thepipe member 52 provided with the underfootcatalytic converter 60 is supported with respect to the vehicle body (floor panel 25) by a support structure similar to that for theupstreammost pipe member 52. - In the first embodiment, the
branch pipe portions 32, the intermediatecollector pipe portions 33, the singleexhaust pipe portion 34 and the manifoldcatalytic converter 40 which constitute theupstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape turning in a clockwise direction toward the exhaust downstream side, in top plan view, so that theupstream exhaust assembly 48 including the manifoldcatalytic converter 40 can be compactly laid out on the vehicle-rear side of theengine 1, while increasing a length of each of thebranch pipe portions 32 and the intermediatecollector pipe portions 33 to enhance exhaust efficiency. In addition, each of the intermediatecollector pipe portions 33 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (vehicle-left side) which is a direction coming close to thetransmission 11, in top plan view, so that the singleexhaust pipe portion 34 is disposed at a position closer to thetransmission 11 than thebranch pipe portions 32. Thus, theupstream exhaust assembly 48 can be disposed away from auxiliary components (water pump, etc.) which are generally disposed on a surface of theengine 1 on an opposite side of thetransmission 11, and a vehicle-right-side sidewall of the engine compartment 19 (the side frame, etc.). The makes it possible to achieve a layout advantageous in terms of space utility, without interference with the auxiliary components, the side frame, etc., and suppress an influence of radiant heat on the auxiliary components and the vehicle-right-side sidewall of theengine compartment 19. Further, even if the length of each of thebranch pipe portions 32 and the intermediatecollector pipe portions 33 is increased, thetunnel portion 25 a is required to allow only the singledownstream exhaust pipe 51 to pass therethrough, so that there is no need to increase a cross-sectional area of thetunnel portion 25 a, which makes it possible to prevent a space of thepassenger compartment 20 from being narrowed. - In this case, there is a possibility that the
upstream exhaust assembly 48 formed in a loop shape brings an disadvantage in terms of exhaust resistance, as compared with a straight shape. However, a diameter of the loop can be set to a relatively large value by laying out theupstream exhaust assembly 48 in the above manner. Thus, a problem of the exhaust resistance practically does not occur, but it becomes possible to increase an output power of theengine 1 based on the exhaust efficiency-enhancing effect obtained by increasing the length of each of thebranch pipe portions 32 and the intermediatecollector pipe portions 33. - Further, the manifold
catalytic converter 40 is disposed adjacent to the vehicle-rear-side surface of theengine 1, so that a traveling wind produced by traveling of the vehicle becomes less likely to touch the manifoldcatalytic converter 40, which makes it possible to more quickly raise a temperature of the catalyst of the manifoldcatalytic converter 40 during warm-up of theengine 1. - Furthermore, the manifold
catalytic converter 40 is disposed on the vehicle-front side of a connection position of each of the intermediatecollector pipe portions 33 and the single exhaust pipe portion 34 (the exhaust upstream end of the single exhaust pipe portion 34) and below thebranch pipe portions 32. Thus, the manifoldcatalytic converter 40 having a large weight is disposed adjacent to theengine 1, so that vibration of theupstream exhaust assembly 48 to be caused by vibration of theengine 1 can be reduced, as compared with an arrangement where the manifoldcatalytic converter 40 is disposed away from theengine 1. In the first embodiment, the manifoldcatalytic converter 40 is supported with respect to the vehicle-rear-side surface of theengine 1, so that theupstream exhaust assembly 48 can be stably supported to further reduce the vibration of theupstream exhaust assembly 48 to be caused by the vibration of theengine 1. - In addition, the exhaust upstream ends of the first and second intermediate
collector pipe portions branch pipe portions 32 from being located just above the exhaust upstream ends of the first and second intermediatecollector pipe portions collector pipe portions collector pipe portions branch pipe portions 32 and the intermediatecollector pipe portions 33, and welding between each of the intermediatecollector pipe portions 33 and the singleexhaust pipe portion 34, can be performed all together so as to increase productivity. -
FIGS. 6 to 8 show an exhaust apparatus E according to a second embodiment of the present invention, wherein a positional relationship between respective exhaust upstream ends of first and second intermediatecollector pipe portions branch pipe portions branch pipe portions - Specifically, in the second embodiment, the exhaust upstream ends of the first and second intermediate
collector pipe portions third fastening point 37 c of aflange portion 36 in the vehicle-widthwise direction, and in offset relation to each other in an upward-downward direction. More specifically, the firstbranch pipe portion 32 a and thefourth branch portion 32 d are merged in the same manner as that in the first embodiment, whereas the secondbranch pipe portion 32 b and thethird branch portion 32 c extend from the vehicle-rear-side surface of theengine 1 toward the vehicle-rear side, and then come close to each other so that they are merged together at approximately the same position as that of thethird fastening point 37 c in the vehicle-widthwise direction. Further, the exhaust upstream end of the first intermediatecollector pipe portion 33 a is located just below the exhaust upstream end of the second intermediatecollector pipe portion 33 b, i.e., the exhaust upstream ends of the first and second intermediatecollector pipe portions collector pipe portion 33 a is located below thethird fastening point 37 c as with the first embodiment, whereas a height position of the exhaust upstream end of the second intermediatecollector pipe portion 33 b is located above thethird fastening point 37 c. This makes it possible to keep an area around thethird fastening point 37 c of theflange portion 36 from overlapping thebranch pipe portions 32 and the intermediatecollector pipe portions 33, when viewed from the vehicle-rear side, as shown inFIG. 8 . Thus, the fastening operation at thethird fastening point 37 c can be performed from the vehicle-rear side. However, a region just above the area around thethird fastening point 37 c of theflange portion 36 overlaps the thirdbranch pipe portion 32 c when viewed from the vehicle-rear side, and thereby it becomes difficult to perform an operation of setting a fastening member in the area around thethird fastening point 37 c from above theengine 1. Thus, efficiency of the fastening operation is slightly inferior to that in the first embodiment. On the other hand, an area around each of the remaining fastening points 37 (37 a, 37 b, 37 d, 37 e) of theflange portion 36 other than thethird fastening point 37 c and a region just above the area do not overlap thebranch pipe portions 32 and the intermediatecollector pipe portions 33 when viewed from the vehicle-rear side. Thus, the fastening operation at each of the remaining fastening points 37 other than thethird fastening point 37 c can be performed with the same efficiency as that in the first embodiment. - The first and second intermediate
collector pipe portions collector pipe portions collector pipe portions collector pipe portions fourth cylinder 2 d in the vehicle-widthwise direction, and a singleexhaust pipe portion 34 is formed on the exhaust downstream side of the merging position. - A configuration and an arrangement of each of a
power plant 12, the singleexhaust pipe portion 34, a manifoldcatalytic converter 40 and adownstream exhaust pipe 51 are the same as those in the first embodiment. By way of exception, in the second embodiment, a casing 41 (gas passage) is not inclined toward the vehicle-rear side as going toward the vehicle-left side, differently from the first embodiment. This is because a maximum vehicle-widthwise protruding amount of the singleexhaust pipe portion 34 with respect to an exhaustupstream end surface 43 a of acatalyst installation portion 43 is set to a value greater than that in the first embodiment, and thereby the gas entry angle with respect to the exhaustupstream end surface 43 a of thecatalyst installation portion 43 can be set as close as possible to 90 degrees without inclining thecasing 41 toward the vehicle-rear side as going toward the vehicle-left side. - As above, in the second embodiment, the
branch pipe portions 32, the intermediatecollector pipe portions 33, the singleexhaust pipe portion 34 and the manifoldcatalytic converter 40 which constitute anupstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape, in top plan view, and each of the intermediatecollector pipe portions 33 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side) which is a direction coming close to thetransmission 11, in top plan view, as with the first embodiment, so that the same functions/effects as those in the first embodiment can be obtained. - In addition, the exhaust upstream ends of the first and second intermediate
collector pipe portions collector pipe portions -
FIGS. 9 to 11 show an exhaust apparatus E according to a third embodiment of the present invention, wherein a positional relationship between respective exhaust upstream ends of first and second intermediatecollector pipe portions branch pipe portions branch pipe portions - Specifically, in the third embodiment, the exhaust upstream ends of the first and second intermediate
collector pipe portions third fastening point 37 c of aflange portion 36 in the vehicle-widthwise direction, as with the second embodiment. However, the exhaust upstream ends of the first and second intermediatecollector pipe portions branch pipe portions branch pipe portions collector pipe portion 33 b (the merging position of the second and thirdbranch pipe portions collector pipe portion 33 a (the merging position of the first and fourthbranch pipe portions collector pipe portion 33 b is approximately equal to a height position of the exhaust upstream end of the first intermediatecollector pipe portion 33 a, and located below thethird fastening point 37 c. This makes it possible to keep an area around thethird fastening point 37 c of theflange portion 36 and a region just above the area from overlapping thebranch pipe portions 32 and the intermediatecollector pipe portions 33, as well as the remaining fastening points 37 (37 a, 37 b, 37 d, 37 e), when viewed from the vehicle-rear side, as shown inFIG. 11 . - Alternatively, the height position of the exhaust upstream end of the second intermediate
collector pipe portion 33 b may be set in the same manner as that in the second embodiment, i.e., may be set to be located above thethird fastening point 37 c. Even in this case, there is a possibility of being able to efficiently perform the operation of setting a fastening member in the area around thethird fastening point 37 c from above theengine 1, because the exhaust upstream end of the second intermediatecollector pipe portion 33 b is located further toward the vehicle-rear side, as compared with the second embodiment. However, in view of enhancing the efficiency of the fastening operation, it is basically more preferable that the exhaust upstream end of the second intermediatecollector pipe portion 33 b is set at a position below thethird fastening point 37 c. - The first and second intermediate
collector pipe portions collector pipe portions collector pipe portion 33 a extends from the exhaust upstream end thereof toward the vehicle-rear side. Then, the first intermediatecollector pipe portion 33 a curves toward the vehicle-left side at a position just below the exhaust upstream end of the second intermediatecollector pipe portion 33 b, and extends toward the vehicle-left side. The second intermediatecollector pipe portion 33 b curves toward the vehicle-left side directly from the exhaust upstream end thereof, and extends toward the vehicle-left side while passing through a region on the vehicle-rear side of the first intermediatecollector pipe portion 33 a. Then, the first and second intermediatecollector pipe portions fourth cylinder 2 d in the vehicle-widthwise direction, to form a singleexhaust pipe portion 34. - A configuration and an arrangement of each of a
power plant 12, the singleexhaust pipe portion 34 and a manifoldcatalytic converter 40 are the same as those in the first or second embodiment. - In the third embodiment, a
downstream exhaust pipe 51 curves toward the vehicle-rear side at an exhaust upstream end thereof. Then, thedownstream exhaust pipe 51 extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-left side (toward the vehicle-widthwise central region of the engine compartment 19), and enters thetunnel portion 25 a while maintaining the inclination. Then, thedownstream exhaust pipe 51 is disposed to pass through a region of thetunnel portion 25 a on the vehicle-right side. Further, asupport member 55 and anelastic member 56 are provided only on the vehicle-right side of thedownstream exhaust pipe 51. The above arrangement is intended to ensure a space (on the vehicle-left side) for allowing a drive shaft for driving rear wheels to pass therethrough, so as to make it possible to promptly change over to the vehicle into a four-wheel-drive vehicle, even if it is an FF vehicle. Thus, in the changeover to a four-wheel-drive vehicle, the drive shaft can be provided without modifying thedownstream exhaust pipe 51, thesupport member 55, etc. - In the third embodiment, an upstreammost one of a plurality of divided
pipe members 52 of thedownstream exhaust pipe 51 has twoflexible joints 53 arranged in series at intervals along a length direction of the downstream exhaust pipe 51 (upstreammost pipe member 52). An exhaust downstream one of theflexible joints 53 is disposed inside thetunnel portion 25 a, whereas the other of exhaust upstream flexible joint 53 is disposed inside theengine compartment 19. - As above, in the third embodiment, the
branch pipe portions 32, the intermediatecollector pipe portions 33, the singleexhaust pipe portion 34 and the manifoldcatalytic converter 40 which constitute anupstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape, in top plan view, and each of the intermediatecollector pipe portions 33 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side) which is a direction coming close to thetransmission 11, in top plan view, as with the first embodiment, so that the same functions/effects as those in the first embodiment can be obtained. -
FIGS. 12 to 14 show an exhaust apparatus E according to a fourth embodiment of the present invention, wherein anexhaust manifold 31 is configured such that the intermediatecollector pipe portions 33 of in the first to third embodiments are eliminated, and fourbranch pipe portions exhaust pipe portion 34. - Specifically, differently from the first to
third embodiments 1 to 3 where a section of theupstream exhaust assembly 48 on the exhaust upstream side of the singleexhaust pipe portion 34 is comprised of thebranch pipe portions 32 and the intermediatecollector pipe portions 33, the section in the fourth embodiment is comprised only of thebranch pipe portions 32. The singleexhaust pipe portion 34 is formed by merging the fourbranch pipe portions 32 a to 32 d together, and directly communicated with thebranch pipe portions 32 without an intermediary of the intermediatecollector pipe portions 33. Each of thebranch pipe portions 32 curves to allow an exhaust downstream region of thebranch pipe portion 32 to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11), in top plan view. Specifically, each of the first and secondbranch pipe portions engine 1 toward the vehicle-rear side, and then curves to allow the exhaust downstream region thereof to one side of the vehicle-widthwise direction (toward the vehicle-left side, i.e., toward the transmission 11), in top plan view. Further, each of the third and fourthbranch pipe portions engine 1 toward the vehicle-rear side, and, shortly thereafter, extends obliquely toward the vehicle-rear side with an inclination toward the vehicle-right side. Then, each of the third and fourthbranch pipe portions branch pipe portions 32 a to 32 d are merged together at an approximately the same vehicle-widthwise position as that of afifth fastening point 37 e of aflange portion 36 to form a singleexhaust pipe portion 34. - A configuration and an arrangement of each of a
power plant 12, the singleexhaust pipe portion 34, a manifoldcatalytic converter 40 and adownstream exhaust pipe 51 are the same as those in the third embodiment. - Thus, in the fourth embodiment, the
branch pipe portions 32, the singleexhaust pipe portion 34 and the manifoldcatalytic converter 40 which constitute anupstream exhaust assembly 48 of the exhaust apparatus E are formed in a loop shape, in top plan view, and each of thebranch pipe portions 32 curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction (toward the vehicle-left side) which is a direction coming close to thetransmission 11, in top plan view, as with the first embodiment, so that the same functions/effects as those in the first embodiment can be obtained. - Although each of the first to fourth embodiments has been described by taking an exhaust apparatus E for an inline four-
cylinder engine 1 as an example, the number of cylinders of theengine 1 is not limited to four. For example, in an exhaust apparatus devoid of the intermediatecollector pipe portions 33, the number of cylinders may be two or more. Further, in an exhaust apparatus provided with the intermediatecollector pipe portions 33, the number of cylinders may be four or more. In an exhaust apparatus provided with the intermediatecollector pipe portions 33, depending on the number of cylinders of theengine 1, the number of the intermediate collector pipe portions 33 (i.e., the number of the cylinder groups) may be increased to three or more, and the number of thebranch pipe portions 32 to be merged to form one of the intermediate collector pipe portions 33 (i.e., the number of cylinders comprised in one of the cylinder groups) may be increased to three or more. - At the last of the description, features of the present invention disclosed based on the above embodiments and advantages thereof will be summarized.
- The present invention is directed to an exhaust apparatus provided in an engine having a plurality of cylinders arranged in a line, wherein the engine is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction, and coupled with a transmission located on one side thereof in the cylinder arrangement direction. The exhaust apparatus comprises an upstream exhaust assembly connected to a surface of the engine on a vehicle-rear side, and a downstream exhaust pipe provided on an exhaust downstream side of the upstream exhaust assembly. The upstream exhaust assembly includes: a plurality of branch pipe portions communicated with respective ones of the plurality of cylinders and extending from the vehicle-rear-side surface of the engine toward the vehicle-rear side; a single exhaust pipe portion provided on the exhaust downstream side of the plurality of branch pipe portions in such a manner that it is communicated with the branch pipe portions; and an exhaust gas-purifying unit connected to an exhaust downstream end of the single exhaust pipe portion. The exhaust gas-purifying unit is disposed on the vehicle-rear side of the engine to allow a gas passage thereinside to extend approximately in the vehicle-widthwise direction, in top plan view. The upstream exhaust assembly includes, on an exhaust upstream side of the single exhaust pipe portion, a section which curves to allow an exhaust downstream region of the section to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view, and the single exhaust pipe portion curves to allow an exhaust downstream region of the single exhaust pipe portion to be oriented toward a vehicle-front side, in top plan view. The downstream exhaust pipe is connected to an exhaust downstream end of the exhaust gas-purifying unit, and disposed to extend from a connection portion thereof with the exhaust gas-purifying unit toward an tunnel opening formed in a vehicle-widthwise central region of a lower end of a dash panel of the vehicle.
- In the exhaust apparatus of the present invention, a section of the upstream exhaust assembly extending from the branch pipe portions to the exhaust gas-purifying unit is formed in a loop shape, in top plan view, so that the upstream exhaust assembly including the exhaust gas-purifying unit can be compactly laid out on the vehicle-rear side of the engine, while increasing a length of each of the branch pipe portions (or each of the branch pipe portions and a plurality of intermediate collector pipe portions) to enhance exhaust efficiency. In addition, the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion (each of the branch pipe portion or the intermediate collector pipe portions) curves to allow the exhaust downstream region thereof to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view, so that the single exhaust pipe portion is disposed at a position closer to the transmission than the branch pipe portions. Thus, the upstream exhaust assembly can be disposed away from auxiliary components (water pump, etc.) which are generally disposed on a surface of the
engine 1 on an opposite side of the transmission, and a sidewall of the engine compartment (a side frame, etc.). The makes it possible to achieve a layout advantageous in terms of space utility, without interference with the auxiliary components, the side frame, etc., and suppress an influence of radiant heat on the auxiliary components and the sidewall of the engine compartment. Further, even if the length of each of the branch pipe portions (or each of the branch pipe portions and the intermediate collector pipe portions) is increased, the tunnel portion is required to allow only the single downstream exhaust pipe to pass therethrough, so that there is no need to increase a cross-sectional area of the tunnel portion. - In this case, there is a possibility that the upstream exhaust assembly formed in a loop shape brings an disadvantage in terms of exhaust resistance, as compared with a straight shape. However, a diameter of the loop can be set to a relatively large value by laying out the upstream exhaust assembly in the above manner. Thus, a problem of the exhaust resistance practically does not occur, but it becomes possible to increase an output power of the
engine 1 based on the exhaust efficiency-enhancing effect obtained by increasing the length of each of the branch pipe portions (or each of the branch pipe portions and the intermediate collector pipe portions). - Further, the upstream exhaust assembly formed in a loop shape makes it possible to distribute an elongation of the upstream exhaust assembly caused by thermal expansion, over the entire loop, so as to prevent degradation of the upstream exhaust assembly due to stress concentration.
- Further, the exhaust gas-purifying unit can be disposed adjacent to the vehicle-rear-side surface of the engine, so that a traveling wind produced by traveling of the vehicle becomes less likely to touch the exhaust gas-purifying unit, which makes it possible to more quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during warm-up of the engine.
- Furthermore, the exhaust gas-purifying unit having a large weight is disposed adjacent to the engine, so that vibration of the upstream exhaust assembly to be caused by vibration of the engine can be reduced, as compared with an arrangement where the exhaust gas-purifying unit is disposed away from the engine.
- As above, the transverse engine exhaust apparatus of the present invention make it possible to compactly lay out the upstream exhaust assembly thereof including the exhaust gas-purifying unit, in the engine compartment without sacrificing a passenger compartment space, and quickly raise a temperature of a catalyst in the exhaust gas-purifying unit during engine warm-up. In addition, an elongation of the upstream exhaust assembly caused by thermal expansion can be distributed, and vibration of the upstream exhaust assembly to be caused by vibration of the engine can be reduced. Further, an influence of radiant heat on auxiliary components and a sidewall of the engine compartment can be suppressed.
- Preferably, the exhaust apparatus of the present invention, the exhaust gas-purifying unit has a catalyst installation portion formed in a cross-sectionally generally circular shape and provided in the gas passage, and a maximum vehicle-widthwise protruding amount of the single exhaust pipe portion with respect to an exhaust upstream end surface of the catalyst installation portion is set to be greater than a maximum vehicle-widthwise protruding amount of the downstream exhaust pipe with respect to an exhaust downstream end surface of the catalyst installation portion, to allow a gas entry angle with respect to the exhaust upstream end surface of the catalyst installation portion to become greater than a gas discharge angle with respect to the exhaust downstream end surface of the catalyst installation portion.
- According to this feature, exhaust gas entering the exhaust upstream end surface of the catalyst installation portion becomes more likely to be uniformly dispersed over the entire cross-section of the catalyst installation portion, to allow a catalyst of the exhaust gas-purifying unit to more efficiently purify exhaust gas. Further, the exhaust upstream end surface (the connection portion with the single exhaust pipe portion) of the catalyst installation portion is located closer to the transmission than the exhaust downstream end surface thereof, so that components and members interferable with the single exhaust pipe portion can be limited to a relatively small member, which makes it easy to increase the maximum vehicle-widthwise protruding amount of the single exhaust pipe portion with respect to the exhaust upstream end surface.
- Preferably, in the exhaust apparatus of the present invention, the exhaust gas-purifying unit is disposed on the vehicle-front side of an exhaust upstream end of the single exhaust pipe portion and below the branch pipe portions.
- According to this feature, the exhaust gas-purifying unit can be disposed closer to the engine, so that it becomes possible to further reduce vibration of the upstream exhaust assembly to be caused by vibration of the engine.
- More preferably, in the above exhaust apparatus, the exhaust gas-purifying unit is supported with respect to the engine, and the downstream exhaust pipe has a flexible joint interposed therein.
- According to this feature, the upstream exhaust assembly including the exhaust gas-purifying unit can be stably supported to further reduce the vibration of the exhaust upstream section to be caused by the vibration of the engine. Although a region of the exhaust apparatus upstream of the flexible joint vibrates together with the engine, the vibration is absorbed by the flexible joint, so that it becomes possible to prevent the vibration from being transmitted to a region located on the exhaust downstream side of the flexible joint (and typically fixed to a vehicle body of the vehicle).
- Preferably, in the exhaust apparatus of the present invention, the upstream exhaust assembly has a plurality of intermediate collector pipe portions between each of the plurality of branch pipe portions and the single exhaust pipe portion, wherein each of the intermediate collector pipe portions is formed by dividing the plurality of cylinders into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other, and merging the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups, on a cylinder group-by-cylinder group basis, and wherein the single exhaust pipe portion is formed by merging the plurality of intermediate collector pipe portions together, and each of the plurality of intermediate collector pipe portions curves to allow an exhaust downstream region of the intermediate collector pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
- According to this feature, an optimal configuration for enhancing exhaust efficiency can be obtained.
- Preferably, in the exhaust apparatus of the present invention, the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion is comprised of the branch pipe portions, wherein the single exhaust pipe portion is formed by merging the plurality of branch pipe portions together, and each of the plurality of branch pipe portions curves to allow an exhaust downstream region of the branch pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
- According to this feature, it becomes possible to eliminate the use of the intermediate collector pipe portions so as to facilitate reduction in cost of the exhaust apparatus.
- This application is based on Japanese Patent application No. 2009-274196 filed in Japan Patent Office on Dec. 2, 2009, the contents of which are hereby incorporated by reference.
- Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereinafter defined, they should be construed as being included therein.
Claims (14)
1. An exhaust apparatus provided in an engine having a plurality of cylinders arranged in a line, wherein the engine is transversely placed in an engine compartment at a front of a vehicle to allow a cylinder arrangement direction to be oriented in a vehicle-widthwise direction, and coupled with a transmission located on one side thereof in the cylinder arrangement direction, the exhaust apparatus comprising an upstream exhaust assembly connected to a surface of the engine on a vehicle-rear side, and a downstream exhaust pipe provided on an exhaust downstream side of the upstream exhaust assembly, wherein the upstream exhaust assembly includes:
a plurality of branch pipe portions communicated with respective ones of the plurality of cylinders and extending from the vehicle-rear-side surface of the engine toward the vehicle-rear side;
a single exhaust pipe portion provided on the exhaust downstream side of the plurality of branch pipe portions in such a manner that it is communicated with the branch pipe portions; and
an exhaust gas-purifying unit connected to an exhaust downstream end of the single exhaust pipe portion,
and wherein:
the exhaust gas-purifying unit is disposed on the vehicle-rear side of the engine to allow a gas passage thereinside to extend approximately in the vehicle-widthwise direction, in top plan view;
the upstream exhaust assembly includes, on an exhaust upstream side of the single exhaust pipe portion, a section which curves to allow an exhaust downstream region of the section to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view;
the single exhaust pipe portion curves to allow an exhaust downstream region of the single exhaust pipe portion to be oriented toward a vehicle-front side, in top plan view; and
the downstream exhaust pipe is connected to an exhaust downstream end of the exhaust gas-purifying unit, and disposed to extend from a connection portion thereof with the exhaust gas-purifying unit toward an tunnel opening formed in a vehicle-widthwise central region of a lower end of a dash panel of the vehicle.
2. The exhaust apparatus as defined in claim 1 , wherein:
the exhaust gas-purifying unit has a catalyst installation portion formed in a cross-sectionally generally circular shape and provided in the gas passage; and
a maximum vehicle-widthwise protruding amount of the single exhaust pipe portion with respect to an exhaust upstream end surface of the catalyst installation portion is set to be greater than a maximum vehicle-widthwise protruding amount of the downstream exhaust pipe with respect to an exhaust downstream end surface of the catalyst installation portion, to allow a gas entry angle with respect to the exhaust upstream end surface of the catalyst installation portion to become greater than a gas discharge angle with respect to the exhaust downstream end surface of the catalyst installation portion.
3. The exhaust apparatus as defined in claim 2 , wherein the exhaust gas-purifying unit is disposed on the vehicle-front side of an exhaust upstream end of the single exhaust pipe portion and below the branch pipe portions.
4. The exhaust apparatus as defined in claim 3 , wherein:
the exhaust gas-purifying unit is supported with respect to the engine; and
the downstream exhaust pipe has a flexible joint interposed therein.
5. The exhaust apparatus as defined in claim 4 , wherein:
the upstream exhaust assembly has a plurality of intermediate collector pipe portions between each of the plurality of branch pipe portions and the single exhaust pipe portion;
each of the intermediate collector pipe portions is formed by dividing the plurality of cylinders into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other, and merging the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups, on a cylinder group-by-cylinder group basis;
the single exhaust pipe portion is formed by merging the plurality of intermediate collector pipe portions together; and
each of the plurality of intermediate collector pipe portions curves to allow an exhaust downstream region of the intermediate collector pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
6. The exhaust apparatus as defined in claim 4 , wherein:
the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion is comprised of the branch pipe portions;
the single exhaust pipe portion is formed by merging the plurality of branch pipe portions together; and
each of the plurality of branch pipe portions curves to allow an exhaust downstream region of the branch pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
7. The exhaust apparatus as defined in claim 1 , wherein the exhaust gas-purifying unit is disposed on the vehicle-front side of an exhaust upstream end of the single exhaust pipe portion and below the branch pipe portions.
8. The exhaust apparatus as defined in claim 7 , wherein:
the exhaust gas-purifying unit is supported with respect to the engine; and
the downstream exhaust pipe has a flexible joint interposed therein.
9. The exhaust apparatus as defined in claim 1 , wherein:
the upstream exhaust assembly has a plurality of intermediate collector pipe portions between each of the plurality of branch pipe portions and the single exhaust pipe portion;
each of the intermediate collector pipe portions is formed by dividing the plurality of cylinders into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other, and merging the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups, on a cylinder group-by-cylinder group basis;
the single exhaust pipe portion is formed by merging the plurality of intermediate collector pipe portions together; and
each of the plurality of intermediate collector pipe portions curves to allow an exhaust downstream region of the intermediate collector pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
10. The exhaust apparatus as defined in claim 1 , wherein:
the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion is comprised of the branch pipe portions;
the single exhaust pipe portion is formed by merging the plurality of branch pipe portions together; and
each of the plurality of branch pipe portions curves to allow an exhaust downstream region of the branch pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
11. The exhaust apparatus as defined in claim 2 , wherein:
the upstream exhaust assembly has a plurality of intermediate collector pipe portions between each of the plurality of branch pipe portions and the single exhaust pipe portion;
each of the intermediate collector pipe portions is formed by dividing the plurality of cylinders into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other, and merging the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups, on a cylinder group-by-cylinder group basis;
the single exhaust pipe portion is formed by merging the plurality of intermediate collector pipe portions together; and
each of the plurality of intermediate collector pipe portions curves to allow an exhaust downstream region of the intermediate collector pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
12. The exhaust apparatus as defined in claim 2 , wherein:
the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion is comprised of the branch pipe portions;
the single exhaust pipe portion is formed by merging the plurality of branch pipe portions together; and
each of the plurality of branch pipe portions curves to allow an exhaust downstream region of the branch pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
13. The exhaust apparatus as defined in claim 3 , wherein:
the upstream exhaust assembly has a plurality of intermediate collector pipe portions between each of the plurality of branch pipe portions and the single exhaust pipe portion;
each of the intermediate collector pipe portions is formed by dividing the plurality of cylinders into a plurality of cylinder groups each consisting of two or more cylinders whose exhaust strokes are not successive with respect to each other, and merging the branch pipe portions communicated with respective ones of the cylinders in each of the cylinder groups, on a cylinder group-by-cylinder group basis;
the single exhaust pipe portion is formed by merging the plurality of intermediate collector pipe portions together; and
each of the plurality of intermediate collector pipe portions curves to allow an exhaust downstream region of the intermediate collector pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
14. The exhaust apparatus as defined in claim 3 , wherein:
the section of the upstream exhaust assembly on the exhaust upstream side of the single exhaust pipe portion is comprised of the branch pipe portions;
the single exhaust pipe portion is formed by merging the plurality of branch pipe portions together; and
each of the plurality of branch pipe portions curves to allow an exhaust downstream region of the branch pipe portion to be oriented toward one side of the vehicle-widthwise direction which is a direction coming close to the transmission, in top plan view.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2009-274196 | 2009-12-02 | ||
JP2009274196A JP2011116204A (en) | 2009-12-02 | 2009-12-02 | Exhaust system of transverse engine |
Publications (1)
Publication Number | Publication Date |
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US20110126522A1 true US20110126522A1 (en) | 2011-06-02 |
Family
ID=44067816
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US12/958,194 Abandoned US20110126522A1 (en) | 2009-12-02 | 2010-12-01 | Exhaust apparatus for transverse engine |
Country Status (4)
Country | Link |
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US (1) | US20110126522A1 (en) |
JP (1) | JP2011116204A (en) |
CN (2) | CN102085805A (en) |
DE (1) | DE102010052937A1 (en) |
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US20170260891A1 (en) * | 2016-03-11 | 2017-09-14 | Mazda Motor Corporation | Exhaust structure for multi-cylinder engine |
US20170342890A1 (en) * | 2016-05-27 | 2017-11-30 | Honda Motor Co., Ltd. | Vehicle and exhaust pipe support member |
EP3418523A4 (en) * | 2016-07-27 | 2019-02-27 | Mazda Motor Corporation | Engine for vehicle |
US20200032685A1 (en) * | 2016-12-16 | 2020-01-30 | Mazda Motor Corporation | Engine exhaust device |
US11008984B2 (en) * | 2017-08-24 | 2021-05-18 | Mazda Motor Corporation | Motor vehicle on which a vehicle engine is mounted |
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EP2682294B1 (en) * | 2012-03-01 | 2015-07-15 | Toyota Jidosha Kabushiki Kaisha | Vehicle front portion structure |
US8910472B2 (en) * | 2012-12-27 | 2014-12-16 | Kawasaki Jukogyo Kabushiki Kaisha | Utility vehicle |
JP6131936B2 (en) * | 2014-12-12 | 2017-05-24 | マツダ株式会社 | Exhaust system for multi-cylinder engine |
JP6304290B2 (en) * | 2016-03-14 | 2018-04-04 | マツダ株式会社 | Exhaust insulator structure for multi-cylinder engines |
JP6468443B2 (en) * | 2016-06-07 | 2019-02-13 | マツダ株式会社 | Exhaust structure of multi-cylinder engine |
JP6493464B2 (en) * | 2017-07-24 | 2019-04-03 | マツダ株式会社 | Engine exhaust system |
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- 2010-12-01 US US12/958,194 patent/US20110126522A1/en not_active Abandoned
- 2010-12-02 CN CN2010105849331A patent/CN102085805A/en active Pending
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Cited By (10)
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US20160084139A1 (en) * | 2014-09-24 | 2016-03-24 | Mazda Motor Corporation | Exhaust device of multi-cylinder engine |
US9611777B2 (en) * | 2014-09-24 | 2017-04-04 | Mazda Motor Corporation | Exhaust device of multi-cylinder engine |
US20170260891A1 (en) * | 2016-03-11 | 2017-09-14 | Mazda Motor Corporation | Exhaust structure for multi-cylinder engine |
US10280825B2 (en) | 2016-03-11 | 2019-05-07 | Mazda Motor Corporation | Exhaust structure for multi-cylinder engine |
US20170342890A1 (en) * | 2016-05-27 | 2017-11-30 | Honda Motor Co., Ltd. | Vehicle and exhaust pipe support member |
US10526950B2 (en) * | 2016-05-27 | 2020-01-07 | Honda Motor Co., Ltd. | Vehicle and exhaust pipe support member |
EP3418523A4 (en) * | 2016-07-27 | 2019-02-27 | Mazda Motor Corporation | Engine for vehicle |
US10995649B2 (en) | 2016-07-27 | 2021-05-04 | Mazda Motor Corporation | Vehicle engine |
US20200032685A1 (en) * | 2016-12-16 | 2020-01-30 | Mazda Motor Corporation | Engine exhaust device |
US11008984B2 (en) * | 2017-08-24 | 2021-05-18 | Mazda Motor Corporation | Motor vehicle on which a vehicle engine is mounted |
Also Published As
Publication number | Publication date |
---|---|
DE102010052937A1 (en) | 2011-07-07 |
CN102085805A (en) | 2011-06-08 |
JP2011116204A (en) | 2011-06-16 |
CN201922921U (en) | 2011-08-10 |
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