JP2011116204A - Exhaust system of transverse engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To early raise the temperature of a catalyst in an exhaust emission control device (a straight catalyst 40) in cold time of an engine 1, by compactly arranging an exhaust upstream side part 48 in an engine room 19 without sacrificing a cabin, in an exhaust system E of the transverse engine 1 of joining a transmission 11 to one side in the cylinder bank direction. <P>SOLUTION: The exhaust upstream side part 48 includes a plurality of branch pipe parts 32, a single exhaust pipe part 34 and the straight catalyst 40. The straight catalyst 40 is arranged on the vehicle rear side of the engine 1 so that a gas flow passage of its inside extends in the substantial vehicle width direction in a plan view, and a part up to becoming the single exhaust pipe 34 from an end part on the exhaust upstream side of the branch pipe parts 32 in the exhaust upstream side part 48, is curved so that the exhaust downstream side of the part turns to the transmission 11 side in the vehicle width direction in a plan view, and the single exhaust pipe part 34 is curved so that the exhaust downstream side of the single exhaust pipe part 34 turns to the vehicle front side in a plan view. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention belongs to a technical field related to an exhaust device for a horizontally mounted engine that is horizontally disposed in an engine room at a front portion of a vehicle so that a cylinder row direction faces a vehicle width direction.

  Conventionally, this type of horizontally mounted engine is well known, and the exhaust device of this horizontally mounted engine is usually disposed on the vehicle rear side of the engine (see, for example, Patent Document 1). The exhaust device is provided with a plurality of branch pipe portions that respectively communicate with a plurality of cylinders of the engine, and these branch pipe portions are gathered to finally become a single exhaust pipe portion. Here, in Patent Document 1, all the cylinders (four cylinders) are divided into a plurality of cylinder groups (a cylinder group consisting of a first cylinder and a fourth cylinder, a second cylinder, A plurality of (two) intermediate collecting pipe portions each of which is formed by collecting the branch pipe portions communicating with a plurality of cylinders of each cylinder group. The two intermediate collecting pipe parts are assembled to form a single exhaust pipe part. In some cases, an intermediate collecting pipe portion is not provided, and all branch pipe portions are gathered to form one collecting pipe portion.

  In recent years, in order to reduce the exhaust gas emission particularly when the engine is cold, the exhaust purification device is provided relatively upstream in order to quickly raise the temperature of the catalyst in the exhaust purification device. In Patent Document 1, an exhaust purification device (direct catalyst) is provided in the intermediate collecting pipe portion.

JP 2008-260472 A

  By the way, in order to increase the engine exhaust efficiency and increase the engine output, it is preferable to make the branch pipe part and the intermediate collecting pipe part (the branch pipe part in the case where no intermediate collecting pipe part is provided) as long as possible. From this point of view, in Patent Document 1, since the branch pipe part and the intermediate collecting pipe part are lengthened, the two intermediate collecting pipe parts are arranged in the tunnel part formed at the center in the vehicle width direction of the floor panel. ing.

  However, when two intermediate collecting pipe parts are arranged in the tunnel part in this way, the width and height (cross-sectional area) of the tunnel part become large. Therefore, the cross-sectional area of the tunnel portion is further increased. Therefore, there is room for improvement from the viewpoint of not narrowing the passenger compartment space. In addition, if the exhaust gas purification device is installed in the tunnel, it will be easier for the vehicle's wind to hit the exhaust gas purification device, improving the temperature of the catalyst in the exhaust gas purification device earlier when the engine is cold. There is room for.

  The present invention has been made in view of such a point, and an object of the present invention is to provide an exhaust upstream portion including an exhaust purification device in an exhaust device of a horizontally mounted engine without sacrificing the passenger compartment. It is to be arranged in the engine room in a compact manner and to increase the temperature of the catalyst in the exhaust purification device at an early stage when the engine is cold.

  In order to achieve the above object, according to the first aspect of the present invention, a plurality of cylinders are arranged in a row, a transmission is coupled to one side of the cylinder row direction, and the cylinder row direction is arranged in the engine room at the front of the vehicle. For an exhaust device of a horizontally mounted engine in which an exhaust upstream side portion including an exhaust purification device of the engine is connected to a side surface on the vehicle rear side of the engine horizontally disposed so as to face the vehicle width direction, The exhaust upstream side portion communicates with the plurality of cylinders and extends from the side surface on the vehicle rear side of the engine to the vehicle rear side, and the branch pipe so as to communicate with the plurality of branch tube portions. A single exhaust pipe portion provided on the exhaust downstream side of the exhaust portion, and the exhaust purification device connected to an end portion on the exhaust downstream side of the single exhaust pipe portion. The gas flow path inside it extends in the vehicle width direction. In addition, the portion of the exhaust upstream side portion that is disposed on the vehicle rear side of the engine and extends from the exhaust upstream end of the branch pipe portion to the single exhaust pipe portion is the portion in plan view. And the single exhaust pipe portion is curved so that the exhaust downstream side of the single exhaust pipe portion is directed to the front side of the vehicle in a plan view. A downstream exhaust pipe connected to the exhaust downstream side end of the exhaust purification device has a tunnel opening formed in the vehicle width direction central portion of the lower end portion of the dash panel of the vehicle from the connection portion with the exhaust purification device It was set as the structure arrange | positioned toward.

  With the above configuration, the portion from the branch pipe portion to the exhaust gas purification device in the exhaust upstream side portion forms a loop shape in a plan view, thereby the length of the branch pipe portion (or the branch pipe portion and the intermediate collecting pipe portion). The exhaust upstream side portion including the exhaust purification device can be compactly arranged on the rear side of the engine while increasing the length and improving the exhaust efficiency. Moreover, the portion from the exhaust upstream side end of the branch pipe portion to the single exhaust pipe portion in the exhaust upstream side portion (when the intermediate collecting pipe portion is provided, the entire branch pipe portion and intermediate collecting pipe portion) Is curved in a plan view so that the exhaust downstream side of the portion is directed toward the transmission side in the vehicle width direction, the single exhaust pipe portion is located on the transmission side with respect to the branch pipe portion in the vehicle width direction. As a result, the exhaust upstream side portion can be disposed closer to the transmission. As a result, the exhaust upstream side part is usually arranged away from the auxiliary equipment (water pump etc.) arranged on the side opposite to the engine transmission in the vehicle width direction and the side wall of the engine room. Can do. As a result, it is possible to achieve a space-friendly arrangement without interference with auxiliary equipment, side frames, and the like, and it is possible to suppress the influence of radiant heat on the side walls of the auxiliary equipment and the engine room. Also, even if the length of the branch pipe (or branch pipe and intermediate collecting pipe) is increased, it is only necessary to pass a single downstream exhaust pipe in the tunnel, and the cross-sectional area of the tunnel is enlarged. do not have to.

  Here, there is a possibility that the exhaust upstream side portion has a loop shape, which may be disadvantageous in terms of exhaust resistance as compared with the straight shape, but in the present invention, the loop diameter is reduced by the above arrangement of the exhaust upstream side portion. Since it can be made relatively large, exhaust resistance hardly becomes a problem, and the engine output is improved by the effect of improving the exhaust efficiency by increasing the length of the branch pipe part (or the branch pipe part and the intermediate collecting pipe part). Can be increased.

  Further, by forming the exhaust upstream portion in a loop shape, the elongation due to thermal expansion of the exhaust upstream portion can be dispersed throughout the loop, and deterioration due to stress concentration in the exhaust upstream portion can be prevented.

  Furthermore, the exhaust purification device can be arranged in the vicinity of the rear side of the engine of the engine, which makes it difficult for the exhaust purification device to hit the vehicle running wind, and the temperature of the catalyst in the exhaust purification device is further increased when the engine is cold. It becomes possible to raise early.

  Furthermore, by arranging the exhaust purification device having a large weight in the vicinity of the engine, it is possible to reduce the vibration of the exhaust upstream side part due to the engine vibration compared to the case where the exhaust purification device is arranged away from the engine. .

  According to a second aspect, in the first aspect, the cross section of the catalyst disposition portion in the gas flow path of the exhaust gas purification device has a substantially circular shape, and the gas entrance angle with respect to the exhaust upstream side end surface of the catalyst disposition portion is The maximum amount of protrusion in the vehicle width direction of the single exhaust pipe portion relative to the exhaust upstream end surface of the catalyst disposition portion is larger than the gas discharge angle with respect to the exhaust downstream end surface of the catalyst disposition portion. In addition, it is assumed that the maximum amount of extension of the downstream exhaust pipe in the vehicle width direction with respect to the exhaust downstream side end face of the catalyst disposition portion is larger.

  As a result, the exhaust gas entering the exhaust gas upstream end face of the catalyst disposition portion is easily diffused uniformly throughout the cross section of the catalyst disposition portion, and the exhaust gas purification by the catalyst of the exhaust purification device is promoted. . In addition, since the end surface on the exhaust upstream side of the catalyst arrangement portion is on the transmission side in the vehicle width direction with respect to the end surface on the exhaust downstream side, there are relatively few parts and members that interfere with the single exhaust pipe portion, It is possible to easily increase the maximum overhang amount of the single exhaust pipe portion in the vehicle width direction with respect to the upstream end surface.

  According to a third invention, in the first or second invention, the exhaust purification device is a part from the exhaust upstream end of the branch pipe part to the single exhaust pipe part in the exhaust upstream part. It is assumed that it is disposed on the vehicle front side and below the branch pipe portion from the exhaust downstream side portion.

  As a result, the exhaust purification device is disposed closer to the engine, and the vibration of the exhaust upstream side part due to engine vibration can be further reduced.

  According to a fourth aspect, in the third aspect, the exhaust purification device is supported by the engine, and a flexible joint is provided in the middle of the downstream exhaust pipe.

  By doing so, the exhaust upstream side portion including the exhaust purification device can be stably supported, and the vibration of the exhaust upstream side portion due to engine vibration can be further reduced. In addition, the portion upstream of the flexible joint in the exhaust system vibrates with the engine, but the vibration is not transmitted to the portion downstream of the flexible joint (usually fixed to the vehicle body). Can be absorbed by a flexible joint.

  According to a fifth invention, in any one of the first to fourth inventions, the exhaust of a part from the exhaust upstream side end of the branch pipe part to the single exhaust pipe part in the exhaust upstream side part The downstream portion divides all the cylinders into a plurality of cylinder groups consisting of a plurality of cylinders whose exhaust strokes are not continuous with each other, and each branch cylinder group communicates with a plurality of cylinders of the cylinder group. The single exhaust pipe part is a final collection pipe part obtained by collecting the plurality of intermediate collection pipe parts, and the plurality of intermediate collection parts. The pipe part is assumed to be curved in plan view so that the exhaust downstream side of the intermediate collecting pipe part is directed toward the transmission in the vehicle width direction.

  As a result, an optimum form can be obtained for improving the exhaust efficiency.

  In a sixth invention, in any one of the first to fourth inventions, a site from the exhaust upstream side end of the branch pipe part to the single exhaust pipe part in the exhaust upstream side part is: The branch pipe part is configured such that the single exhaust pipe part is a collection of the plurality of branch pipe parts, and each branch pipe part has an exhaust downstream side of the branch pipe part in a plan view. It is assumed that the vehicle is curved toward the transmission side in the vehicle width direction.

  This eliminates the need for the intermediate collecting pipe portion, and can reduce the cost of the exhaust device.

  As described above, according to the exhaust device for a horizontal engine of the present invention, the exhaust upstream side portion including the exhaust purification device can be compactly disposed in the engine room without sacrificing the passenger compartment, and the engine During the cold time, the temperature of the catalyst in the exhaust purification device can be raised early. Further, it is possible to disperse the elongation due to the thermal expansion of the exhaust upstream side portion, and to reduce the vibration of the exhaust upstream side portion due to engine vibration. Furthermore, the influence of the radiant heat on the engine auxiliary machine and the engine room side wall can be suppressed.

It is a top view which shows the mounting state to the vehicle of the exhaust apparatus which concerns on Embodiment 1 of this invention. It is the side view seen from the vehicle left side which shows the mounting state to the vehicle of the said exhaust apparatus. It is a top view which shows the division | segmentation pipe | tube of the most upstream part in the exhaust upstream part and the downstream exhaust pipe of the said exhaust apparatus. It is the side view seen from the vehicle left side which shows the division | segmentation pipe | tube of the most upstream part in the exhaust upstream part and the downstream exhaust pipe of the said exhaust apparatus. It is the figure seen from the vehicle rear side which shows the division | segmentation pipe | tube of the most upstream part in the exhaust upstream part and the downstream exhaust pipe of the said exhaust apparatus. FIG. 4 is a view corresponding to FIG. FIG. 5 is a view corresponding to FIG. FIG. 6 is a view corresponding to FIG. FIG. 6 is a view corresponding to FIG. FIG. 5 is a view corresponding to FIG. FIG. 6 is a view corresponding to FIG. FIG. 6 is a view corresponding to FIG. FIG. 5 is a diagram corresponding to FIG. FIG. 5 is a diagram corresponding to FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
1 and 2 show an exhaust device E according to Embodiment 1 of the present invention, and this exhaust device E is an exhaust device of a horizontally mounted engine 1. This engine 1 is an in-line four-cylinder engine having four cylinders 2 arranged in a row, and the engine row 19 is laterally oriented in the vehicle width direction (left-right direction in FIG. 1) in an engine room 19 at the front of the vehicle. It is placed in a place. The engine 1 is disposed closer to the vehicle right side (right side in FIG. 1) in the vehicle width direction of the engine room 19. Further, the engine 1 is disposed to be inclined (slant) toward the rear side of the vehicle toward the upper side.

  A transmission 11 is coupled to one side in the cylinder row direction of the engine 1 (in this embodiment, the vehicle left side (left side in FIG. 1)), and the engine 1 and the transmission 11 constitute a power plant 12. is doing. The transmission 11 is of a horizontal type in which an input shaft and an output shaft (not shown) extend in the vehicle width direction, and the input shaft is connected to a crankshaft extending in the vehicle width direction of the engine 1. The output shaft is connected to a differential device 14 disposed on the vehicle rear side of the transmission 11. Although not shown, left and right front wheel drive shafts respectively connected to the left and right front wheels extend from the differential device 14 to both sides in the vehicle width direction. The vehicle is an FF vehicle whose left and right front wheels are driven by the engine 1. The vehicle may be a four-wheel drive vehicle.

  Left and right side frames 21 and 22 are respectively disposed on both sides of the power plant 12 in the vehicle width direction. That is, the left side frame 21 is disposed on the left side of the transmission 11 and the right side frame 22 is disposed on the right side of the engine 1 so as to extend in the vehicle front-rear direction.

  The vehicle rear side wall of the engine room 19 is constituted by a dash panel 23 that partitions the engine room 19 and the vehicle compartment 20. The dash panel 23 extends in the vertical direction and the vehicle width direction. The upper end portion of the dash panel 23 is coupled to the cowl member 24, and the lower end portion of the dash panel 23 is coupled to the front end portion of the floor panel 25 that forms the floor surface of the passenger compartment 20.

  A tunnel portion 25a bulging upward in a substantially inverted U-shaped cross section is formed at the vehicle width direction central portion of the floor panel 25 so as to extend in the vehicle front-rear direction. A tunnel opening 23a is formed in the vehicle width direction central portion of the lower end portion of the dash panel 23 so as to be cut out upward so as to be connected to the tunnel portion 25a. Then, one exhaust pipe (a downstream exhaust pipe 51 described later) passes through the inside of the tunnel portion 25a (outside of the passenger compartment 20). When the vehicle is a four-wheel drive vehicle, the exhaust pipe and the drive shaft for driving the rear wheels pass through the tunnel portion 25a.

  An intake manifold 4 for introducing intake air into each cylinder 2 of the engine 1 is disposed on the vehicle front side of the engine 1. The intake manifold 4 communicates with the four cylinders 2 of the engine 1 and is connected to the openings of four intake ports (not shown) that open on the side of the engine 1 on the front side of the vehicle. -4d, and these branch pipe portions 4a-4d are curved so as to surround the surge tank 5 extending in the cylinder row direction (vehicle width direction).

  On the other hand, on the vehicle rear side of the engine 1, the exhaust device E for discharging exhaust gas in each cylinder 2 of the engine 1 is disposed. Hereinafter, details of the exhaust device E will be described in detail with reference to FIGS.

  The exhaust device E includes an exhaust manifold 31, a direct catalyst 40 as an exhaust purification device of the engine 1, and a downstream exhaust pipe 51, which are arranged in this order from the exhaust upstream side. The exhaust manifold 31 and the direct catalyst 40 correspond to the exhaust upstream side portion 48 of the exhaust device E and are accommodated in the engine room 19.

  The exhaust manifold 31 includes four branch pipe portions 32 that respectively communicate with the four cylinders 2 of the engine 1, and two intermediate collecting pipe portions 33 that are formed by assembling two of the four branch pipe portions 32. A single final collecting pipe portion 34 (corresponding to a single exhaust pipe portion) formed by collecting the two intermediate collecting pipe portions 33 together. A direct catalyst 40 is connected to the end of the final collecting pipe 34 on the exhaust downstream side.

  Hereinafter, the four cylinders 2 are arranged in order from the side opposite to the transmission 11 (front side of the engine 2 (vehicle right side)) toward the transmission 11 side (rear side of the engine 2 (vehicle left side)). The cylinder 2a, the second cylinder 2b, the third cylinder 2c, and the fourth cylinder 2d are referred to as “cylinder 2”. Further, the branch pipe portions 32 communicating with the first cylinder 2a to the fourth cylinder 2d are referred to as first to fourth branch pipe portions 32a to 32d, respectively. There is also.)

  All the branches for attaching the first to fourth branch pipe portions 32a to 32d to the vehicle rear side surface of the engine 1 are arranged at the exhaust upstream end of the first to fourth branch pipe portions 32a to 32d. One flange portion 36 extending in the vehicle width direction common to the pipe portions 32 a to 32 d is provided, and the first to fourth branch pipe portions are attached by attaching the flange portion 36 to the side surface on the vehicle rear side of the engine 1. 32a to 32d are respectively connected to the openings of four exhaust ports (not shown) communicating with the first cylinder 2a to the fourth cylinder 2d and opening on the side surface of the engine 1 on the rear side of the vehicle.

  The flange portion 36 has a plurality (five in this embodiment) of fastening portions 37 that are fastened to a side surface of the engine 1 on the vehicle rear side by fastening members such as bolts. These fastening portions 37 are configured by fastening member insertion holes through which fastening members such as bolts are inserted. Hereinafter, these five fastening portions 37 are referred to as first to fifth fastening portions 37a to 37e in order from the right side of the vehicle (in some cases, they may be simply referred to as fastening portions 37 if they are not distinguished).

  The first fastening portion 37a is located at a position corresponding to the outer side in the vehicle width direction (right side of the vehicle) of the first cylinder 2a in the flange portion 36, and the second fastening portion 37b is connected to the first cylinder 2a and the second cylinder in the flange portion 36. The third fastening portion 37c is located at a corresponding position between the second cylinder 2b and the third cylinder 2c in the flange portion 36, and the fourth fastening portion 37d is The flange portion 36 is located at a position corresponding to between the third cylinder 2c and the fourth cylinder 2d, and the fifth fastening portion 37e is located outside the fourth cylinder 2d in the vehicle width direction (the left side of the vehicle) at the flange portion 36. Located in the corresponding position. The first to fifth fastening portions 37a to 37e are arranged so that two fastening portion rows extending in the vehicle width direction (cylinder row direction) are arranged at intervals in the height direction. The upper fastening part row including the fastening parts 37b and 37d is located at the first height position near the upper end of the flange part 36, and includes the first, third and fifth fastening parts 37a, 37c and 37e. The lower fastening portion row is located at the second height position near the lower end of the flange portion 36. Thus, the second and fourth fastening portions 37b and 37d correspond to high-position fastening portions located at the first height position, and the first, third and fifth fastening portions 37a, 37c and 37e are This corresponds to the low position fastening portion located at the second height position lower than the first height position. And the 1st-5th fastening parts 37a-37e are zigzag so that the fastening part 37 of the upper fastening part row | line | column exists in the part corresponding to between the fastening parts 37 adjacent to a lower fastening part row | line | column. Is arranged.

  The intermediate collecting pipe section 33 divides all the cylinders 2 into two sets of cylinder groups composed of two cylinders 2 whose exhaust strokes (explosion strokes) are not continuous with each other, and each cylinder group is divided into two cylinder groups. The branch pipe portions 32 communicating with the two cylinders 2 are assembled together. In the present embodiment, since the exhaust stroke is performed in the order of the first cylinder 2a, the third cylinder 2c, the fourth cylinder 2d, and the second cylinder 2b, a cylinder group including the first cylinder 2a and the fourth cylinder 2d, and 2 It is divided into a cylinder group consisting of a No. 2 cylinder and a No. 3 cylinder 2c, and is an intermediate formed by assembling first and fourth branch pipe portions 32a, 32d communicating with the No. 1 cylinder 2a and No. 4 cylinder 2d, respectively. The collecting pipe part 33 and the intermediate collecting pipe part 33 formed by collecting the second and third branch pipe parts 32b and 32c communicating with the second cylinder 32b and the third cylinder 32c, respectively, are provided. Hereinafter, the intermediate collecting pipe portion 33 formed by assembling the first and fourth branch pipe portions 32a and 32d is referred to as a first intermediate collecting pipe portion 33a, and the second and third branch pipe portions 32b and 32c are gathered together. The intermediate collecting pipe portion 33 thus formed is referred to as a second intermediate collecting pipe portion 33b (in some cases, the intermediate collecting pipe portion 33 may be simply referred to as an intermediate collecting pipe portion 33 if they are not distinguished).

  The first to fourth branch pipe portions 32a to 32d basically extend from the side surface (strictly speaking, the flange portion 36) of the engine 1 to the vehicle rear side. Specifically, the first branch pipe portion 32a extends from the side surface to the vehicle rear side in a plan view, and then obliquely extends to the vehicle left side toward the vehicle rear side. The fourth branch pipe portion 32d In view, the first branch pipe portion 32a extends from the side surface to the rear side of the vehicle and then obliquely extends to the right side of the vehicle toward the rear side of the vehicle, at substantially the same position as the third fastening portion 37c in the vehicle width direction. And the fourth branch pipe part 32d gather to form the first intermediate collecting pipe part 33a. The second branch pipe portion 32b extends from the side surface to the vehicle rear side in a plan view, and then obliquely extends to the vehicle right side toward the vehicle rear side, and is curved in front of the second intermediate collecting pipe portion 33b. Thus, it extends obliquely to the left side of the vehicle toward the rear side of the vehicle. The third branch pipe portion 32c extends from the side surface to the vehicle rear side in a plan view, and then obliquely extends to the vehicle right side toward the vehicle rear side, and is substantially the same as the second fastening portion 37b in the vehicle width direction. At the position, the second branch pipe part 32b and the third branch pipe part 32c gather to form the second intermediate collecting pipe part 33b. The second and third branch pipe portions 32b and 32c extend from the left side of the first branch pipe portion 32a to the right side through the lower side of the first branch pipe portion 32a.

  In the present embodiment, the exhaust upstream end portions of the first and second intermediate collecting pipe portions 33a and 33b (the collecting portion of the first branch pipe portion 32a and the fourth branch pipe portion 32d, and the second branch pipe portion). 32b and the third branch pipe portion 32c) are arranged so as to be shifted from each other in the vehicle width direction. That is, the exhaust upstream end of the first intermediate collecting pipe part 33a (the collecting part of the first branch pipe part 32a and the fourth branch pipe part 32d) is the end of the second intermediate collecting pipe part 33b on the exhaust upstream side. It is located on the vehicle left side (the transmission 11 side in the vehicle width direction) with respect to the portion (the gathering portion of the second branch pipe portion 32b and the third branch pipe portion 32c). The height position of the exhaust upstream side end portion of the first intermediate collecting pipe portion 33a is substantially the same as the height position of the exhaust upstream side end portion of the second intermediate collecting pipe portion 33b (strictly speaking, 2 is slightly higher than the height position of the upstream end portion of the intermediate collecting pipe portion 33b), and is lower than the third fastening portion 37c. As a result, as shown in FIG. 5, when viewed from the rear side of the vehicle, the location of the fastening portion 37 (particularly the third fastening portion 37 c) in the flange portion 36 and the portion directly above the fastening portion 37 are connected to each branch pipe portion 32 and each intermediate assembly. It can be made not to overlap with the pipe part 33. As a result, a space for fastening work at each fastening part 37 (particularly, the third fastening part 37c) can be secured, and fastening work can be easily performed by disposing a fastening member from the upper side of the engine 1 to each fastening part 37. Can be done.

  In the first and second intermediate collecting pipe portions 33a and 33b, the exhaust downstream side of the first and second intermediate collecting pipe portions 33a and 33b is one side in the vehicle width direction (in this embodiment, the left side of the vehicle, that is, the vehicle). The final collecting pipe portion 34 is formed by curving toward the transmission 11 in the width direction and gathering together. That is, the first intermediate collecting pipe portion 33a extends from the exhaust upstream end to the rear side of the vehicle and then curves to the left side of the vehicle, and the second intermediate collecting pipe portion 33b immediately extends from the exhaust upstream end. It curves to the left side of the vehicle and extends to the left side of the vehicle through the lower side of the upstream end of the first intermediate collecting pipe portion 33a. The first and second intermediate collecting pipe portions 33a and 33b are gathered at the substantially same position as the fourth cylinder in the vehicle width direction (near the center in the vehicle width direction of the engine room 19) to form the final collecting pipe portion 34. . Accordingly, the final collecting pipe portion 34 is provided on the exhaust downstream side of the branch pipe portion 32 and communicates with the four branch pipe portions 32a to 32d via the first and second intermediate collecting pipe portions 33a and 33b. It will be.

  The final collecting pipe portion 34 is bent so that the exhaust downstream side of the final collecting pipe portion 34 faces the vehicle front side in a plan view, and is connected to the direct catalyst 40. A portion of the final collecting pipe portion 34 on the exhaust downstream side is curved toward the vehicle right side toward the front side of the vehicle, and the intermediate portion of the final collecting pipe portion 34 is opposite to the direct catalyst 40 with respect to both ends. It has a curved shape that is convex to the side (left side of the vehicle). The end of the final collecting pipe 34 on the exhaust downstream side is increased in diameter so as to have the same diameter as a case 41 (described later) of the direct catalyst 40, and the end surface of the case 41 on the exhaust upstream side (the end surface on the left side of the vehicle). Connected.

  The said direct catalyst 40 is arrange | positioned at the vehicle rear side of the engine 1 so that the gas flow path in case 41 may extend in a vehicle width direction by planar view. Thus, the case 41 extends substantially along the side surface of the engine 1 on the vehicle rear side. In the present embodiment, strictly speaking, the case 41 (gas flow path) is slightly inclined toward the vehicle rear side toward the vehicle left side. This is because, as will be described later, the gas entry angle with respect to the end surface 43a on the exhaust upstream side of the catalyst disposition portion 43 is as close to 90 ° as possible. Further, the case 41 (gas flow path) is slightly inclined toward the lower side toward the vehicle right side (exhaust downstream side). This is because the downstream side exhaust pipe 51 is located below the second and third branch parts 32b and 32c and the second intermediate collecting pipe part 33b, so that interference with them is avoided.

  The direct catalyst 40 has a catalyst disposed in a gas flow path in a substantially cylindrical case 41. The cross section of the catalyst disposition portion 43 in the gas flow path in the case 41 has a substantially circular shape, and the end surface 43a on the exhaust upstream side (vehicle left side) and the end surface 43b on the exhaust downstream side (vehicle right side) of the catalyst disposition portion 43. Are substantially the same surface with respect to the end surface on the exhaust upstream side and the end surface on the exhaust downstream side of the case 41, or slightly located inside the case 41. The catalyst is a three-way catalyst and is intended to purify HC and CO particularly when the engine 1 is cold. For this purpose, a direct catalyst 40 is provided in the exhaust upstream portion 48 of the exhaust device E. Yes. Note that the cross-sectional shape of the catalyst disposing portion 43 is not limited to a substantially circular shape.

  In the present embodiment, the direct catalyst 40 is attached to and supported by the side surface of the engine 1 on the vehicle rear side. That is, a projecting member 41a that projects downward is fixed to the case 41, and a support member that is substantially L-shaped when viewed from below between the projecting member 41a and the side surface of the engine 1 on the rear side of the vehicle. 44 is provided, and the direct catalyst 40 is supported on the vehicle rear side surface of the engine 1 through the support member 44. It is not always necessary to support the direct catalyst 40 for the engine 1.

  The downstream exhaust pipe 51 is connected to the exhaust downstream end surface (the vehicle right end surface) of the case 41 in the direct catalyst 40. The downstream exhaust pipe 51 is directed from a connecting portion (end portion on the exhaust upstream side) with the direct catalyst 40 toward a tunnel opening portion 23 a formed in the vehicle width direction central portion of the lower end portion of the dash panel 23. It is arranged. That is, in a plan view, the downstream side exhaust pipe 51 is bent toward the rear side of the vehicle at the end on the upstream side of the exhaust and extends toward the rear of the vehicle, and then toward the rear side of the vehicle. And extends from the front side of the tunnel opening 23a to the rear side of the vehicle and enters the tunnel portion 25a from the tunnel opening 23a. The downstream exhaust pipe 51 includes a plurality of divided pipes 52 that are divided into a plurality of parts in the length direction. Two adjacent split pipes 52 are connected to each other via a flange 52 a formed at the connecting end of both split pipes 52. In FIGS. 1 and 2, only the split pipe 52 at the most upstream part and a part of the split pipe 52 immediately downstream of the exhaust gas are shown, and the other split pipes 52 are not shown. Moreover, in FIGS. 3-5, only the dividing pipe 52 of the most upstream part is shown.

  A portion on the exhaust downstream side of the final collecting pipe portion 34 protrudes toward the left side of the vehicle with respect to an end surface 43a on the exhaust upstream side of the catalyst disposing portion 43 in the direct catalyst 40, and an exhaust upstream side in the downstream exhaust pipe 51. The portion on the side protrudes to the right side of the vehicle with respect to the end surface 43b on the exhaust downstream side of the catalyst arrangement portion 43. The catalyst disposition portion is arranged such that the gas entry angle with respect to the exhaust upstream side end surface 43a of the catalyst disposition portion 43 is larger than the gas discharge angle with respect to the exhaust downstream side end surface 43b of the catalyst disposition portion 43. 43 in the vehicle width direction of the final collecting pipe portion 34 with respect to the end surface 43a on the exhaust upstream side of 43 is in the vehicle width direction of the downstream exhaust pipe 51 with respect to the end surface 43b on the exhaust downstream side of the catalyst disposing portion 43. It is larger than the maximum overhang. That is, the portion of the final collecting pipe portion 34 on the exhaust downstream side is less inclined than the portion of the downstream exhaust pipe 51 on the exhaust upstream side with respect to the direction in which the case 41 (catalyst disposing portion 43) extends and the case 41 ( The catalyst arrangement portion 43) is extended in the extending direction, and the gas entry angle with respect to the end surface 43a on the exhaust upstream side of the catalyst arrangement portion 43 is made as close to 90 ° as possible to enter the catalyst arrangement portion 43. The exhaust gas is uniformly diffused over the entire cross section of the catalyst disposition portion 43.

  A flexible joint 53 is disposed in the split pipe 52 at the most upstream portion in the downstream exhaust pipe 51. The flexible joint 53 is located in the tunnel portion 25 a and absorbs the vibration of the engine 1 and the vibration of the exhaust upstream side portion 48 accompanying the vibration of the engine 1, and the vibration is more downstream than the flexible joint 53. It is intended not to transmit to the part. The number of flexible joints 53 is not limited to one, and a plurality of flexible joints 53 may be arranged in series at intervals in the length direction of the downstream side exhaust pipe 51 (see Embodiment 3 and below). 4).

  The uppermost split pipe 52 is supported by the vehicle body (floor panel 25) at the exhaust downstream side of the flexible joint 53. That is, the elongated rod-shaped support member 55 is bent into a substantially trapezoidal shape, and the upper side portion of the support member 55 is fixed in the vicinity of the flange 52a of the split pipe 52 at the most upstream portion, and both sides of the lower side portion of the support member 55 The end portions protrude outward in the vehicle width direction, and the protruding tips are attached to the floor panel 25 via elastic members 56. When a plurality of flexible joints 53 are provided in the split pipe 52 at the most upstream portion, the split pipe 52 at the most upstream portion is supported on the vehicle body at a portion on the exhaust downstream side of the flexible joint 53 at the most downstream portion. What should I do?

  An underfoot catalyst 60 having the same configuration as that of the direct catalyst 40 is disposed in the split pipe 52 immediately downstream of the exhaust with respect to the split pipe 52 in the uppermost stream portion. The catalyst of the underfoot catalyst 60 is also a three-way catalyst like the direct catalyst 40, but mainly purifies NOx. The split pipe 52 provided with the underfoot catalyst 60 is also supported by the vehicle body (floor panel 25) in the same support form as the split pipe 52 in the uppermost stream portion.

  In the present embodiment, the branch pipe part 32, the intermediate collecting pipe part 33, the final collecting pipe part 34, and the direct catalyst 40 that form the exhaust upstream side portion 48 of the exhaust device E are clocked toward the exhaust downstream side in plan view. In this way, a loop shape that turns around is formed, so that the length of the branch pipe portion 32 and the intermediate collecting pipe portion 33 is increased to improve the exhaust efficiency, and the direct catalyst 40 on the rear side of the vehicle of the engine 1 is improved. It is possible to arrange the exhaust upstream side portion 48 including the compactly. Moreover, the intermediate collecting pipe portion 33 is curved so that the exhaust downstream side of the intermediate collecting pipe portion 33 is directed toward the transmission 11 in the vehicle width direction in plan view, and the final collecting pipe portion 34 is branched in the vehicle width direction. Accordingly, the exhaust upstream side portion 48 can be disposed so as to be close to the transmission 11, and as a result, the transmission of the engine 1 normally in the vehicle width direction. 11, the exhaust upstream side portion 48 can be arranged away from the auxiliary machine (water pump or the like) arranged on the side surface opposite to the vehicle 11 or the vehicle right side wall of the engine room 19. As a result, it is possible to achieve a space-friendly arrangement without interference with auxiliary machines, side frames, etc., and it is also possible to suppress the influence of radiant heat on the right side wall of the auxiliary machine or engine room 19. . Further, even if the lengths of the branch pipe portion 32 and the intermediate collecting pipe portion 33 are increased, it is only necessary to pass the single downstream exhaust pipe 51 in the tunnel portion 25a, and it is necessary to enlarge the cross-sectional area of the tunnel portion 25a. No, the space of the vehicle compartment 20 can be prevented from becoming narrow.

  Here, there is a possibility that the exhaust upstream side portion 48 has a loop shape, which may be disadvantageous in terms of exhaust resistance as compared with the straight shape, but the arrangement of the exhaust upstream side portion 48 makes the loop diameter relatively small. Since it can be increased, the exhaust resistance hardly becomes a problem, and the output of the engine 1 can be increased by improving the exhaust efficiency by increasing the length of the branch pipe portion 32 and the intermediate collecting pipe portion 33. become.

  Further, the direct catalyst 40 can be disposed in the vicinity of the rear side of the engine 1 so that the vehicle running wind does not easily hit the direct catalyst 40 and the catalyst of the direct catalyst 40 is cold when the engine 1 is cold. It becomes possible to raise the temperature of the earlier.

  Furthermore, the direct catalyst 40 having a large weight can be disposed in the vicinity of the engine 1, and the exhaust upstream side portion 48 caused by the vibration of the engine 1 can be compared with the case where the direct catalyst 40 is disposed away from the engine 1. Can be reduced. In the present embodiment, the direct catalyst 40 is supported on the side surface of the engine 1 on the rear side of the vehicle. Therefore, the exhaust upstream side portion 48 can be stably supported, and the vibration of the engine 1 is accompanied. The vibration of the exhaust upstream portion 48 can be further reduced.

  In addition, since the exhaust upstream end portions of the first and second intermediate collecting pipe portions 33a and 33b are shifted from each other in the vehicle width direction, the branch pipe portion 32 does not exist above the end portions. Can be. Further, the exhaust upstream end of the final collecting pipe part 34 (the collecting part of the first intermediate collecting pipe part 33a and the second intermediate collecting pipe part 33b) is also connected to the first and second intermediate collecting pipe parts 33a and 33b. It is arranged so as to be shifted in the vehicle width direction with respect to the end portion on the exhaust upstream side, and there is no part of the exhaust device E above all the end portions. Therefore, the welding between the branch pipe part 32 and the intermediate collecting pipe part 33 and the welding between the intermediate collecting pipe part 33 and the final collecting pipe part 34 can be performed all at once, and the productivity can be improved.

(Embodiment 2)
6 to 8 show Embodiment 2 of the present invention, and the exhaust upstream end portions (the first branch pipe portion 32a and the fourth branch pipe portion 32d, in the first and second intermediate collecting pipe portions 33a and 33b). And the positional relationship of the second branch pipe part 32b and the third branch pipe part 32c) are different from those of the first embodiment.

  That is, in the present embodiment, the exhaust upstream end portions of the first and second intermediate collecting pipe portions 33a and 33b are both located at substantially the same position as the third fastening portion 37c in the vehicle width direction, and They are displaced in the direction. Specifically, the manner of assembly of the first branch pipe portion 32a and the fourth branch pipe portion 32d is the same as that of the first embodiment, but the second branch pipe portion 32b and the third branch pipe portion 32c After extending from the vehicle rear side surface of the vehicle 1 to the vehicle rear side, they approach each other and gather at substantially the same position as the third fastening portion 37c in the vehicle width direction. The exhaust upstream end of the first intermediate collecting pipe portion 33a is positioned directly below the exhaust upstream end of the second intermediate collecting pipe portion 33b and overlaps with each other in plan view. The height position of the end portion on the exhaust upstream side in the first intermediate collecting pipe portion 33a is lower than the third fastening portion 37c, as in the first embodiment, but the exhaust position in the second intermediate collecting pipe portion 33b. The height position of the upstream end is higher than the third fastening portion 37c. As a result, as shown in FIG. 8, the position of the third fastening portion 37 c in the flange portion 36 can be prevented from overlapping the branch pipe portions 32 and the intermediate collecting pipe portions 33 when viewed from the rear side of the vehicle. The fastening operation at the third fastening portion 37c can be performed from the rear side of the vehicle. However, since the portion directly above the third fastening portion 37c in the flange portion 36 overlaps with the third branch pipe portion 32c when viewed from the rear side of the vehicle, the fastening member is moved from the upper side of the engine 1 to the third fastening portion 37c. It is difficult to perform the work of arranging the parts, and the fastening workability is slightly inferior to that of the first embodiment. On the other hand, as viewed from the rear side of the vehicle, the location of the fastening portion 37 excluding the third fastening portion 37c in the flange portion 36 and the portion directly above it do not overlap with each branch pipe portion 32 and each intermediate collecting pipe portion 33. In the fastening part 37 excluding the third fastening part 37c, the fastening workability similar to that of the first embodiment is obtained.

  In the first and second intermediate collecting pipe portions 33a and 33b, the exhaust downstream side of the first and second intermediate collecting pipe portions 33a and 33b is one side in the vehicle width direction (the left side of the vehicle, that is, the transmission in the vehicle width direction). 11 side) and gather together. That is, the first and second intermediate collecting pipe portions 33a and 33b are overlapped with each other in plan view, extend from the exhaust upstream side end portion to the vehicle rear side, and then curve to the vehicle left side and extend to the vehicle left side. ing. The first and second intermediate collecting pipe portions 33a and 33b are gathered at substantially the same position as the fourth cylinder 2d in the vehicle width direction to form the final collecting pipe portion 34.

  The configuration and arrangement of the power plant 12, the final collecting pipe section 34, the direct catalyst 40, and the downstream side exhaust pipe 51 are the same as those in the first embodiment. In the present embodiment, the case 41 (gas flow path) is not inclined toward the vehicle rear side toward the vehicle left side as in the first embodiment. This is because the maximum overhang amount in the vehicle width direction of the final collecting pipe portion 34 with respect to the end surface 43a on the exhaust upstream side of the catalyst arrangement portion 43 is made larger than that in the above-described embodiment, so that the case 41 is directed toward the left side of the vehicle. This is because the gas entry angle with respect to the end surface 43a on the exhaust upstream side of the catalyst disposing portion 43 can be brought close to 90 ° without tilting to the rear side of the vehicle.

  Therefore, also in the present embodiment, as in the first embodiment, the branch pipe portion 32, the intermediate collecting pipe portion 33, the final collecting pipe portion 34, and the direct catalyst 40 that constitute the exhaust upstream side portion 48 of the exhaust device E are provided. In addition, the intermediate collecting pipe portion 33 is curved so that the exhaust downstream side of the intermediate collecting pipe portion 33 is directed toward the transmission 11 in the vehicle width direction when viewed in a plan view. Similar effects can be obtained.

  Further, since the exhaust upstream end portions of the first and second intermediate collecting pipe portions 33a and 33b overlap each other in plan view, the first and second intermediate collecting pipes can be used effectively by utilizing the vertical space. The curvature radii of the portions 33a and 33b can be made substantially the same and relatively large.

(Embodiment 3)
9 to 11 show Embodiment 3 of the present invention, and the exhaust upstream end portions (the first branch pipe portion 32a and the fourth branch pipe portion 32d, in the first and second intermediate collecting pipe portions 33a and 33b). And the positional relationship of the second branch pipe part 32b and the third branch pipe part 32c) are further different.

  That is, in the present embodiment, the exhaust upstream end of the first and second intermediate collecting pipe portions 33a and 33b is located at substantially the same position as the third fastening portion 37c in the vehicle width direction, as in the second embodiment. Although located, the exhaust upstream end portions of the first and second intermediate collecting pipe portions 33a and 33b do not overlap with each other in a plan view and are shifted in the vehicle longitudinal direction. Specifically, the length of the second and third branch pipe portions 32b and 32c in the vehicle front-rear direction is longer than the length of the first and fourth branch pipe portions 32a and 32d in the vehicle front-rear direction. The end portion on the exhaust upstream side of the second intermediate collecting pipe portion 33b (the collecting portion of the second branch pipe portion 32b and the third branch pipe portion 32c) is the end portion on the exhaust upstream side of the first intermediate collecting pipe portion 33a (first It is located on the vehicle rear side of a collecting portion of the branch pipe portion 32a and the fourth branch pipe portion 32d. The height position of the end portion on the exhaust upstream side in the second intermediate collecting pipe portion 33b is substantially the same as the height position of the end portion on the exhaust upstream side in the first intermediate collecting pipe portion 33a, and the third fastening position It is a position lower than the part 37c. Thus, as shown in FIG. 11, when viewed from the rear side of the vehicle, the location of the third fastening portion 37 c and the portion directly above the flange portion 36 are the same as the other fastening portions 37, and each branch pipe portion 32 and It does not overlap with each intermediate collecting pipe part 33.

  Note that the height position of the end portion on the exhaust upstream side of the second intermediate collecting pipe portion 33b can be set to a height position similar to that of the second embodiment, that is, a position higher than the third fastening portion 37c. . In this case, since the position of the end portion on the exhaust upstream side of the second intermediate collecting pipe portion 33b is on the rear side of the vehicle as compared with the second embodiment, the fastening member is moved from the upper side of the engine 1 to the third fastening portion 37c. Although there is a possibility that the placement work may be easier, basically, the height position of the end portion on the exhaust upstream side of the second intermediate collecting pipe portion 33b is set to a position lower than that of the third fastening portion 37c. Fastening workability is improved.

  In the first and second intermediate collecting pipe portions 33a and 33b, the exhaust downstream side of the first and second intermediate collecting pipe portions 33a and 33b is one side in the vehicle width direction (the left side of the vehicle, that is, the transmission in the vehicle width direction). 11 side) and gather together. That is, the first intermediate collecting pipe portion 33a extends from the end on the exhaust upstream side to the rear side of the vehicle, and then curves to the left side of the vehicle at the lower position of the end portion on the exhaust upstream side in the second intermediate collecting pipe portion 33b. The second intermediate collecting pipe portion 33b curves to the left side of the vehicle immediately from the exhaust upstream end thereof, and extends to the left side of the vehicle through the rear side of the vehicle from the first intermediate collecting pipe portion 33a. ing. The first and second intermediate collecting pipe portions 33a and 33b are gathered at substantially the same position as the fourth cylinder 2d in the vehicle width direction to form the final collecting pipe portion 34.

  The configuration and arrangement of the power plant 12, the final collecting pipe section 34, and the direct catalyst 40 are the same as those in the first or second embodiment.

  In the present embodiment, in a plan view, the downstream side exhaust pipe 51 is bent toward the rear side of the vehicle at the end on the upstream side of the exhaust gas, and then toward the rear side of the vehicle (left side of the engine room 19 in the vehicle width direction). Inclined to extend into the tunnel portion 25a as it is. And this downstream exhaust pipe 51 is arrange | positioned so that the vehicle right side part of the tunnel part 25a may be passed. Further, the support member 55 and the elastic member 56 are provided only on the vehicle right side of the downstream side exhaust pipe 51. This is because a space (a space on the left side of the vehicle) through which the drive shaft for driving the rear wheels passes is provided in the tunnel portion 25a so that the vehicle can be immediately changed to a four-wheel drive vehicle even if the vehicle is an FF vehicle. Secure. Thus, when changing to a four-wheel drive vehicle, the drive shaft can be provided without changing the downstream exhaust pipe 51, the support member 55, and the like.

  Further, in the present embodiment, two flexible joints 53 are arranged in series at the most upstream part of the split pipe 52 in the downstream exhaust pipe 51 with a distance from each other in the length direction of the downstream exhaust pipe 51 (split pipe 52). It is arranged. The flexible joint 53 on the exhaust downstream side is disposed in the tunnel portion 25 a, but the flexible joint 53 on the exhaust upstream side is disposed in the engine room 19.

  Therefore, also in the present embodiment, as in the first embodiment, the branch pipe portion 32, the intermediate collecting pipe portion 33, the final collecting pipe portion 34, and the direct catalyst 40 that constitute the exhaust upstream side portion 48 of the exhaust device E are provided. In addition, the intermediate collecting pipe portion 33 is curved so that the exhaust downstream side of the intermediate collecting pipe portion 33 is directed toward the transmission 11 in the vehicle width direction when viewed in a plan view. Similar effects can be obtained.

(Embodiment 4)
12 to 14 show a fourth embodiment of the present invention. In the exhaust manifold 31, the intermediate collecting pipe portion 33 in the first to third embodiments is eliminated, and all the branch pipe portions 32a to 32d are assembled to form a final collecting pipe. This is part 34. In the present embodiment, the final collecting pipe portion 34 is referred to as a single exhaust pipe portion 34.

  That is, in the first to third embodiments, the exhaust downstream side portion of the exhaust upstream side portion 48 from the end portion on the exhaust upstream side of the branch pipe portion 32 to the single exhaust pipe portion 34 is the intermediate collecting pipe portion. In this embodiment, the portion from the exhaust upstream end of the branch pipe portion 32 to the single exhaust pipe portion 34 in the exhaust upstream portion 48 is configured by the branch pipe portion 32. Has been. The single exhaust pipe part 34 is formed by assembling the four branch pipe parts 32 a to 32 d and communicates directly with each branch pipe part 32 without the intermediate collecting pipe part 33. Each branch pipe portion 32 is curved so that the exhaust downstream side of the branch pipe portion 32 faces the vehicle left side (the transmission 11 side in the vehicle width direction) in plan view. Specifically, the first and second branch pipe portions 32a and 32b extend from the vehicle rear side surface of the engine 1 to the vehicle rear side, and then, in plan view, the first and second branch pipe portions 32a and 32b. The exhaust downstream side is curved so as to go to the left side of the vehicle (the transmission 11 side in the vehicle width direction). The third and fourth branch pipe portions 32c and 32d extend from the side surface toward the rear side of the vehicle and immediately extend obliquely toward the right side of the vehicle toward the rear side of the vehicle. Thereafter, the third and fourth branch pipe portions 32c, The exhaust downstream side of 32d is curved to the left side of the vehicle (the transmission 11 side in the vehicle width direction). And the four branch pipe parts 32a-32d gather in the substantially the same position as the 4th fastening part 37c in the vehicle width direction, and become the single exhaust pipe part 34. FIG.

  The configuration and arrangement of the power plant 12, the single exhaust pipe section 34, the direct catalyst 40 and the downstream exhaust pipe 51 are the same as those in the third embodiment.

  Therefore, also in the present embodiment, as in the first embodiment, the branch pipe portion 32, the single exhaust pipe portion 34, and the direct catalyst 40 that constitute the exhaust upstream side portion 48 of the exhaust device E are looped in a plan view. In addition, since the branch pipe portion 32 is curved so that the exhaust downstream side of the branch pipe portion 32 is directed toward the transmission 11 in the vehicle width direction in a plan view, the same effects as those of the first embodiment can be obtained. .

  In the first to fourth embodiments, the exhaust device E of the in-line four-cylinder engine 1 has been described as an example. However, the number of cylinders of the engine 1 is not limited to four, and the intermediate collecting pipe portion 33 is not provided. The number of cylinders may be two or more. Further, the number of cylinders in the case of providing the intermediate collecting pipe portion 33 may be four or more. When the intermediate collecting pipe portion 33 is provided, the number of intermediate collecting pipe portions 33 (that is, the number of sets of cylinder groups) may be three or more according to the number of cylinders of the engine 1. The number of branch pipe portions 32 to be gathered together (that is, the number of cylinders included in one cylinder group) may be three or more.

  INDUSTRIAL APPLICABILITY The present invention is useful for an exhaust device for a horizontally mounted engine that is horizontally disposed in an engine room at the front of the vehicle so that the cylinder row direction faces the vehicle width direction. This is useful for improving the exhaust efficiency by increasing the length of the.

1 engine 2 cylinder 11 transmission 19 engine room 23 dash panel 25 floor panel 25a tunnel part 32 branch pipe part 33 intermediate collecting pipe part 34 final collecting pipe part (single exhaust pipe part)
40 direct catalyst (exhaust gas purification device)
43 Catalyst disposing portion 43a End surface on the upstream side of the catalyst disposing portion 43b End surface on the exhaust downstream side of the catalyst disposing portion 48 Exhaust upstream portion 51 Downstream exhaust pipe 53 Flexible joint

Claims (6)

An engine having a plurality of cylinders arranged in a row and having a transmission coupled to one side in the cylinder row direction and arranged horizontally in the engine room at the front of the vehicle so that the cylinder row direction faces the vehicle width direction. An exhaust device for a horizontally mounted engine, wherein an exhaust upstream side portion including an exhaust purification device for the engine is connected to a side surface on the vehicle rear side,
The exhaust upstream side part is
A plurality of branch pipe portions respectively communicating with the plurality of cylinders and extending from the vehicle rear side surface of the engine to the vehicle rear side;
A single exhaust pipe provided on the exhaust downstream side of the branch pipe so as to communicate with the plurality of branch pipes;
The exhaust purification device connected to the exhaust downstream end of the single exhaust pipe section;
Including
The exhaust purification device is disposed on the vehicle rear side of the engine so that the gas flow passage inside thereof extends in the vehicle width direction in plan view,
The portion of the exhaust upstream portion from the exhaust upstream end of the branch pipe portion to the single exhaust pipe portion is the exhaust downstream side of the portion toward the transmission in the vehicle width direction in plan view. Curved and
The single exhaust pipe part is curved so that the exhaust downstream side of the single exhaust pipe part is directed to the vehicle front side in plan view,
A downstream exhaust pipe connected to an exhaust downstream side end of the exhaust purification device has a tunnel opening formed at a vehicle width direction central portion at a lower end portion of the dash panel of the vehicle from a connection portion with the exhaust purification device An exhaust device for a horizontally mounted engine, characterized in that the exhaust device is disposed so as to be directed toward the engine. The exhaust device for a horizontal engine according to claim 1,
The cross section of the catalyst arrangement portion in the gas flow path of the exhaust purification device has a substantially circular shape,
End surface on the exhaust upstream side of the catalyst arrangement portion so that the gas entry angle with respect to the end surface on the exhaust upstream side of the catalyst arrangement portion is larger than the gas discharge angle with respect to the end surface on the exhaust downstream side of the catalyst arrangement portion. The maximum amount of protrusion in the vehicle width direction of the single exhaust pipe portion with respect to the exhaust pipe is greater than the maximum amount of protrusion in the vehicle width direction of the downstream exhaust pipe with respect to the exhaust downstream end surface of the catalyst disposition portion. Features a horizontal engine exhaust system. The exhaust device for a horizontal engine according to claim 1 or 2,
The exhaust purification device is located on the vehicle front side of the exhaust downstream side portion of the portion from the exhaust upstream end of the branch pipe portion to the single exhaust pipe portion in the exhaust upstream portion and the branch pipe portion. An exhaust device for a horizontally mounted engine, characterized in that the exhaust device is disposed on the lower side of the engine. The exhaust device for a horizontal engine according to claim 3,
The exhaust purification device is supported by the engine,
An exhaust system for a horizontally mounted engine, wherein a flexible joint is provided in the middle of the downstream exhaust pipe. The exhaust device for a horizontal engine according to any one of claims 1 to 4,
The exhaust downstream side portion of the portion from the exhaust upstream side end of the branch pipe portion to the single exhaust pipe portion in the exhaust upstream side portion includes a plurality of cylinders in which the exhaust stroke is not continuous with each other. Divided into a plurality of sets of cylinder groups, and each set of cylinder groups is composed of a plurality of intermediate collecting pipe portions formed by collecting branch pipe portions communicating with a plurality of cylinders of the cylinder group.
The single exhaust pipe part is a final collecting pipe part formed by collecting the plurality of intermediate collecting pipe parts,
The exhaust system for a horizontally mounted engine, wherein the plurality of intermediate collecting pipe portions are curved so that an exhaust downstream side of the intermediate collecting pipe portion is directed to the transmission side in a vehicle width direction in a plan view. The exhaust device for a horizontal engine according to any one of claims 1 to 4,
The part from the exhaust upstream side end of the branch pipe part in the exhaust upstream part to the single exhaust pipe part is composed of the branch pipe part,
The single exhaust pipe part is a collection of the plurality of branch pipe parts.
Each of the branch pipe portions is curved so that the exhaust downstream side of the branch pipe portion faces the transmission side in the vehicle width direction in a plan view.

Images