JP7120031B2 - engine exhaust system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine exhaust system in which, for example, a catalyst for purifying engine exhaust gas is supported on a power train via a catalyst support structure.

2. Description of the Related Art In general, an exhaust system that guides and discharges exhaust gas generated by a vehicle engine to the outside of the vehicle is equipped with a catalyst as a purifying device that purifies harmful substances and particulate matter contained in the exhaust gas.
For example, in the exhaust system of the engine in Patent Document 1, a three-dimensional catalyst connected to the downstream end of the exhaust manifold, and a gasoline particulate filter connected to the three-dimensional catalyst are connected to harmful substances and particles. It is arranged as a catalyst for purifying such substances.

Furthermore, in Patent Document 1, a three-dimensional catalyst and a catalyst consisting of a gasoline particulate filter are supported by three support portions provided in the engine and the transmission.
Specifically, the catalyst of Patent Document 1 includes a first support portion (second connection pipe support portion) that supports the three-dimensional catalyst, a second support portion (lower side support portion) that supports the left side of the gasoline particulate filter. 2GPF support member) and the third support (transmission) that supports the right side of the gasoline particulate filter.

By the way, when assembling the catalyst of Patent Document 1 to the exhaust manifold, the catalyst is placed on the three support portions while aligning the position of the catalyst with respect to the end portion of the exhaust manifold.
However, the catalyst disclosed in Patent Document 1 not only tends to be heavy in weight, but also has a center of gravity in the area surrounded by the connecting portion between the exhaust manifold and the catalyst and the three support portions. It is likely to be located at a position different from the approximate center.

For this reason, for example, in Patent Document 1, when a catalyst is temporarily assembled to three support portions, the catalyst rotates about an imaginary straight line connecting the end portion of the exhaust manifold and the second support portion as a rotation axis. As a result, a gap is generated between the exhaust manifold and the catalyst, which causes a problem of deterioration in the assembling property of the catalyst to the exhaust manifold.

In order to solve such a problem, it is conceivable to provide the supporting portion with a detent that restricts the rotation of the catalyst. Not only is it impossible to mount the catalyst at a desired position, but the mounting and bolting of the catalyst are hindered by the anti-rotation, and there is a risk that the ease of mounting the catalyst to the exhaust manifold will not be improved.

JP 2018-150821 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust system for an engine that is capable of both restricting rotation of the catalyst and improving the ease of assembly of the catalyst to the exhaust manifold.

The present invention relates to an engine comprising an exhaust manifold for flowing down exhaust gas emitted by a vehicle engine, a catalyst connected to a downstream end of the exhaust manifold, and a catalyst support structure supporting the catalyst. In the exhaust system, the catalyst support structure includes an upper support member arranged on the catalyst, and a lower support arranged below the upper support member in the vehicle and fastened and fixed to the power train or the vehicle body. The lower support member includes a mounting portion having a flat surface on which the upper support member is mounted and fixed, and a top end of the upper support member mounted on the mounting portion. A substantially plate-shaped eaves in plan view protruding from a position spaced above the vehicle at a predetermined distance from the mounting portion so as to overlap with each other, and between the mounting portion and the eaves Assuming that the direction in which the upper support member is inserted into the upper support member is the direction of assembly, the eaves are formed so that the distance between the eaves and the mounting portion in the vertical direction of the vehicle gradually widens in a direction opposite to the direction of assembly. characterized by being
According to the present invention, it is possible to achieve both regulation of rotation of the catalyst and improvement in the ease of assembly of the catalyst to the exhaust manifold.

Specifically, when the catalyst starts to rotate, the upper support member, which starts to rotate integrally with the catalyst, comes into contact with the eaves provided on the lower support member. Rotation can be regulated.
As a result, the exhaust system of the engine can suppress the formation of a gap between the end portion of the exhaust manifold and the catalyst due to the rotation of the catalyst, thereby facilitating connection between the end portion of the exhaust manifold and the catalyst.

Furthermore, since the eaves are formed so that the ends overlap with the upper support member placed on the mounting portion in a plan view, the engine exhaust system has a high visibility of the mounting portion due to the eaves. decline can be suppressed. Therefore, the exhaust system of the engine can prevent the mounting of the catalyst and the tightening of bolts from being hindered by the eaves.

In addition, the eaves are formed such that the distance between the eaves portion and the mounting portion in the vertical direction of the vehicle gradually widens in the direction opposite to the assembling direction. The gap in the vertical direction of the vehicle is formed so as to gradually narrow.

Therefore, the engine exhaust system can ensure a large insertion opening for the upper support member, and the eaves can guide the movement of the upper support member in the assembly direction. As a result, the engine exhaust system can easily insert the upper support member between the mounting portion and the hood portion even if the catalyst is heavy.
Therefore, the exhaust system of the engine can both restrict the rotation of the catalyst and improve the ease of assembly of the catalyst to the exhaust manifold.

As an aspect of the present invention, the mounting portion of the lower support member may be formed in a shape positioned above the vehicle with respect to the end portion of the exhaust manifold.
According to the present invention, the exhaust system of the engine can reliably regulate the rotation of the catalyst, and further improve the ease of mounting the catalyst to the exhaust manifold.
Specifically, for example, in the case of a lower support member in which the mounting portion is positioned below the vehicle from the end portion of the exhaust manifold, the visibility of the mounting portion may be reduced by the catalyst.

On the other hand, by using the lower support member in which the mounting portion is positioned above the end of the exhaust manifold in the vehicle, the engine exhaust system can prevent the deterioration of the visibility of the mounting portion due to the catalyst. can.

Further, in the exhaust system of the engine, the rotation of the catalyst with the end of the exhaust manifold as one end of the rotation axis is directed to the lower support member in which the mounting portion is positioned at substantially the same position in the vertical direction of the vehicle as the end of the exhaust manifold. can be regulated earlier and more reliably.

Therefore, the engine exhaust system can reliably regulate the rotation of the catalyst by the lower support member having the mounting portion positioned above the end of the exhaust manifold, and the catalyst can be easily assembled to the exhaust manifold. can be improved.

Further, as an aspect of the present invention, the catalyst is composed of a first catalyst connected to the end portion of the exhaust manifold and a second catalyst connected to the first catalyst, and the first catalyst and the The second catalyst may be connected in a generally L-shape in plan view.
According to the present invention, the exhaust system of an engine can achieve both regulation of rotation of the catalyst and improvement in the assembling property of the catalyst to the exhaust manifold, even if the catalyst has a center of gravity positioned at a position disadvantageous to rotation. can be done.

Specifically, since the first catalyst and the second catalyst are connected in a substantially L-shape in plan view, the center of gravity of the catalyst is located at a disadvantageous position with respect to rotation.
Therefore, by providing the eaves on the lower support member, the engine exhaust system can restrict the rotation of the catalyst even if the center of gravity of the catalyst is positioned at a disadvantageous position with respect to the rotation. .

Furthermore, in the engine exhaust system, the upper support member can be supported by the eaves of the lower support member, so that the upper support member whose rotation is restricted can be stabilized. Therefore, in the engine exhaust system, for example, the upper support member and the lower support member can be easily fastened.
Therefore, even if the catalyst has a center of gravity positioned at a position disadvantageous to rotation, the exhaust system of the engine can achieve both regulation of rotation of the catalyst and improvement in ease of assembly of the catalyst to the exhaust manifold. .

Moreover, as an aspect of the present invention, the end portion of the exhaust manifold and the catalyst may be connected by a V-clamp.
According to the present invention, the exhaust system of the engine can connect the end portion of the exhaust manifold and the catalyst with a reduced number of parts compared to the case where the end portion of the exhaust manifold and the catalyst are fastened with bolts.

Furthermore, the engine exhaust system can prevent the gap between the end of the exhaust manifold and the catalyst from expanding due to the rotation of the upper support member, so that connection using a V-clamp can be facilitated.
Therefore, in the exhaust system of the engine, by connecting the end of the exhaust manifold and the catalyst with the V-clamp, it is possible to suppress an increase in the number of parts and further improve the ease of assembly of the catalyst to the exhaust manifold. .

According to the present invention, it is possible to provide an exhaust system for an engine that is capable of both restricting rotation of the catalyst and improving the ease of assembly of the catalyst to the exhaust manifold.

FIG. 2 is a plan view showing the exhaust system of the engine in a plan view; FIG. 2 is a rear view showing an exhaust manifold and a catalyst as viewed from the rear; FIG. 3 is an external perspective view showing the external appearance of a first support structure; FIG. 4 is an external perspective view showing external appearances of a second support structure and a third support structure; FIG. 4 is an exploded perspective view showing the appearance of the third support structure in an exploded state; The right side view which shows a 3rd support structure by right side view. The top view which shows a 3rd support structure by planar view.

An embodiment of the invention will be described below with reference to the drawings.
The vehicle 1 of the present embodiment is a front-wheel drive vehicle having, for example, a transverse engine 2 (hereinafter referred to as "engine 2") that uses gasoline or the like as fuel. An exhaust system for the engine 2 in such a vehicle 1 will be described in detail with reference to FIGS. 1 to 7. FIG.

1 shows a plan view of the exhaust system 4 of the engine 2, FIG. 2 shows a rear view of the exhaust manifold 5 and the catalyst 6, and FIG. 3 shows an external perspective view of the first catalyst support structure 30. , FIG. 4 shows an external perspective view of the second catalyst support structure 50 and the third catalyst support structure 70, FIG. 5 shows an exploded perspective view of the third catalyst support structure 70 in an exploded state, 6 shows a right side view of the third catalyst support structure 70, and FIG. 7 shows a plan view of the third catalyst support structure 70. FIG.

For clarity of illustration, the detailed illustration of the engine 2 and the transmission 3 is omitted in FIG. 2, and the illustration of the bolt 73 is omitted in FIGS.
In the drawings, arrows Fr and Rr indicate the front-rear direction, with arrow Fr indicating the front and arrow Rr indicating the rear. Furthermore, the arrows Rh and Lh indicate the vehicle width direction, the arrow Rh indicates the right direction, and the arrow Lh indicates the left direction.

First, as shown in FIG. 1, the vehicle 1 of the present embodiment includes, as a power train, an engine 2 having four cylinders in the vehicle width direction, and a transmission 3 connected to the left side of the engine 2 in the vehicle width direction. Equipped at the front of the vehicle.
Furthermore, as shown in FIG. 1, the vehicle 1 includes an exhaust manifold 5, a catalyst 6, a pre-silencer 7, and a main silencer 8 as an exhaust system 4 for flowing down the exhaust gas discharged from the engine 2 to the rear part of the vehicle. They are connected to the back of the engine 2 in this order from the front of the vehicle via a pipe 9 .

As shown in FIG. 2, the engine 2 includes an engine block 21 that rotatably supports a crankshaft (not shown) having a rotation axis in the vehicle width direction, a cylinder head 22 mounted on the upper surface of the engine block 21, It is composed of a head cover 23 attached to the upper surface of the cylinder head 22 and an oil pan 24 attached to the lower surface of the engine block 21 .

Specifically, as shown in FIG. 2, the engine block 21 includes an upper block 25 that supports the crankshaft from above the vehicle, and a lower block 26 that supports the crankshaft from below the vehicle.
Although not shown in detail, the upper block 25 has an internal space in which four cylinders arranged at predetermined intervals in the vehicle width direction communicate with a space capable of accommodating a crankshaft. formed. The upper block 25 is provided with a piston, a connecting rod, and the like.

Further, although detailed illustration is omitted, the cylinder head 22 is an upper portion of the combustion chamber, a plurality of intake ports serving as inflow passages for air supplied to the combustion chamber, and an exhaust passage for exhaust gas generated in the combustion chamber. A plurality of exhaust ports are formed.

1 and 2, the exhaust manifold 5 is mounted on the rear surface of the cylinder head 22 so that the exhaust gases discharged toward the rear of the vehicle from each exhaust port join together on the right side in the vehicle width direction. It is configured.
Specifically, as shown in FIG. 2, the exhaust manifold 5 includes a flange portion 5a attached and fixed to the rear surface of the cylinder head 22, and a plurality of exhaust ports communicating with the exhaust ports of the cylinder head 22 via the flange portion 5a. It is composed of a pipe portion 5b and a collection portion 5c where the pipe portions 5b are collected.

As shown in FIGS. 1 and 2, the collective portion 5c extends to a position below the vehicle from the cylinder head 22 on the right side of the exhaust manifold 5 in the vehicle width direction, and then extends toward the left side in the vehicle width direction. is set. Further, a substantially circular flange portion (not shown) to which the catalyst 6 is connected is provided at the tip of the collective portion 5c extending leftward in the vehicle width direction.

The flange portion of the collecting portion 5c is formed with a substantially circular outlet opening (not shown) for discharging the exhaust gas flowing down from the right side in the vehicle width direction to the left side in the vehicle width direction. .
That is, the exhaust manifold 5 gathers the exhaust gas discharged toward the rear of the vehicle from each exhaust port of the engine 2 at the gathering portion 5c, and then flows downward in the order of the right side in the vehicle width direction, the lower side of the vehicle, and the left side in the vehicle width direction. It is designed to allow

As shown in FIGS. 1 and 2, the catalyst 6 is connected to a flange portion, which is the downstream end portion of the exhaust manifold 5, and directs the exhaust gas discharged from the outlet opening of the flange portion further in the vehicle width direction. After flowing down to the left side, it is configured in a substantially L shape in a plan view that is deflected toward the rear of the vehicle.

1 and 2, the catalyst 6 includes a first catalyst 61 having a substantially circular flange portion (not shown) connected to the exhaust manifold 5, and a second catalyst 61 connected to the first catalyst 61. It is composed of a catalyst 62 and a heat shield plate 63 that integrally covers the first catalyst 61 and the second catalyst 62 .

Specifically, as shown in FIGS. 1 and 2, the first catalyst 61 is, for example, a three-dimensional catalyst or the like, which is arranged on the rear side of the engine 2 and extends from right to left in the vehicle width direction. Exhaust gas is configured to flow down. As shown in FIGS. 1 and 2 , the first catalyst 61 has a substantially circular flange portion (not shown) connected to the flange portion of the exhaust manifold 5 via a V clamp 10 .

Since the V-clamp 10 is a well-known technique, detailed description thereof will be omitted, but the V-clamp 10 is a substantially annular hose clamp having an inner surface with a substantially V-shaped cross section, and by tightening it in the circumferential direction, the exhaust manifold can be 5 and the flange portion of the first catalyst 61 are configured to be in close contact with each other in the vehicle width direction.

On the other hand, as shown in FIGS. 1 and 2, the second catalyst 62 is, for example, a gasoline particulate filter or the like, and is arranged close to the vehicle rear side of the first catalyst 61. Exhaust gas from the catalyst 61 is configured to flow downward toward the rear of the vehicle and downward of the vehicle.

As shown in FIG. 2, the second catalyst 62 is connected to the rear part of the vehicle via a bellows pipe 64 integrally connected to the right rear part in the vehicle width direction and an exhaust pipe 9 connected to the bellows pipe 64. It is connected to the silencer 7.
Further, in the second catalyst 62, as shown in FIG. 2, the EGR pipe 65, which is a pipe for recirculating a part of the exhaust gas to the engine 2 and extends in the longitudinal direction of the vehicle, extends at the rear end of the pipe. It is integrally connected to the rear on the left side of the direction.
Due to this configuration, the center of gravity of the catalyst 6 is positioned at the right rear portion of the second catalyst 62 in the vehicle width direction.

As shown in FIGS. 2 to 4, the catalyst 6 described above includes a first catalyst support structure 30 that supports the right side of the second catalyst 62 in the vehicle width direction, and a left side of the second catalyst 62 in the vehicle width direction. It is connected to the engine 2 and the transmission 3 via a second catalyst support structure 50 and a third catalyst support structure 70 that supports the left side of the first catalyst 61 in the vehicle width direction.

As shown in FIGS. 2 and 3, the first catalyst support structure 30 is arranged behind the vehicle and slightly below the flange portion of the exhaust manifold 5. The right side in the vehicle width direction and the rear surface of the upper block 25 are connected.

As shown in FIGS. 2 and 3, the first catalyst support structure 30 includes a first lower support member 31 fastened and fixed to the back surface of the upper block 25, and a first lower support member 31. It is composed of an intermediate support member 32 fastened to its tip, and a first upper support member 33 fastened and fixed to the intermediate support member 32 and joined to the right side of the second catalyst 62 in the vehicle width direction.

Specifically, as shown in FIG. 3, the first lower support member 31 is, for example, a support member made of cast metal, and includes an attachment portion 31a that abuts on the back surface of the upper block 25, and a It is integrally formed with an arm portion 31b extending rearward of the vehicle. As shown in FIG. 2, the first lower support member 31 has an attachment portion 31a fastened and fixed to the lower right portion of the rear surface of the upper block 25 in the vehicle width direction.

As shown in FIG. 3, the intermediate support member 32 is, for example, a press-formed metal support member, and includes an upper surface portion that is a substantially flat upper surface and a left side that is vertically provided from the left side of the upper surface portion in the vehicle width direction. It is formed in an inverted L shape in a rear view having a surface portion.
As shown in FIGS. 2 and 3, the intermediate support member 32 is formed so that the upper surface portion is positioned below the vehicle relative to the radial center of the outlet opening of the exhaust manifold 5 .
As shown in FIG. 3, the intermediate support member 32 has its left side portion fastened and fixed to the tip of the arm portion 31b of the first lower support member 31. As shown in FIG.

As shown in FIG. 3, the first upper support member 33 is, for example, a press-formed metal support member, and has a lower surface that is a substantially flat lower surface, a front end of the lower surface, and a rear end. It is formed in a substantially inverted gate shape in a side view having a front wall portion and a rear wall portion which are respectively erected.

The first upper support member 33 is joined to the lower right side surface of the second catalyst 62 through an opening provided in the heat shield plate 63 .
As shown in FIG. 3, the first upper supporting member 33 has its lower surface portion fastened and fixed to the upper surface portion of the intermediate supporting member 32 .

2 and 4, the second catalyst support structure 50 is arranged on the left side of the first catalyst support structure 30 in the vehicle width direction with the catalyst 6 interposed therebetween. The vehicle width direction left side of the catalyst 62 and the converter housing 3a of the transmission 3 are connected.

As shown in FIG. 4, the second catalyst support structure 50 includes a second lower support member 51 fastened and fixed to the converter housing 3a of the transmission 3, and a front end of the second lower support member 51. , and a second upper support member 52 that supports the second catalyst 62 .

Specifically, as shown in FIG. 4, the second lower support member 51 is, for example, a support member made of casting, and includes an attachment portion 51a elongated in the vertical direction of the vehicle, which is fastened and fixed to the converter housing 3a. , a pair of arm portions 51b extending rearward of the vehicle from the upper portion and the lower portion of the mounting portion 51a, respectively, and a substantially cylindrical end portion 51c extending in the vehicle vertical direction provided at the tip of the pair of arm portions 51b in a side view. It is formed in a substantially triangular shape.

The end portion 51c of the second lower support member 51 has a substantially flat upper surface, and has a screw hole (not shown) into which a fastening member for fastening the second upper support member 52 is screwed. An opening is formed in the vertical direction.
The second lower support member 51 is formed such that the upper surface of the end portion 51c is located below the vehicle with respect to the upper surface of the intermediate support member 32 in the first catalyst support structure 30. As shown in FIG.

As shown in FIG. 4, the second upper support member 52 is, for example, a press-formed metal support member, and has a lower surface that is a substantially flat lower surface, a front end of the lower surface, and a rear end. It is formed in a substantially inverted gate shape in a side view having a front wall portion and a rear wall portion which are respectively erected.

The second upper support member 52 has a front wall portion and a rear wall portion joined to the EGR pipe 65 and supports the second catalyst 62 via the EGR pipe 65 .
As shown in FIG. 4, the second upper supporting member 52 has its lower surface portion fastened and fixed to the upper surface portion of the second lower supporting member 51 .

2 and 4, the third catalyst support structure 70 is arranged behind the second catalyst support structure 50 and above the vehicle. , and the rear surface of the upper block 25 are connected to each other.

Specifically, as shown in FIG. 4, the third catalyst support structure 70 includes a third upper support member 71 joined to the left side of the first catalyst 61 in the vehicle width direction, and a third upper support member. A third lower support member 72 whose upper part is fastened and fixed to 71 and whose lower part is fastened and fixed to the rear surface of the upper block 25 .

As shown in FIG. 5, the third upper support member 71 is, for example, a press-formed metal support member, and bolts 73 (see FIG. 4) screwed to the third lower support member 72. an upper joint portion 712 joined to the left side in the vehicle width direction of the upper surface of the first catalyst 61; It is composed of a lower joint portion 713 that is

As shown in FIG. 5, the third upper support member 71 is composed of a substantially flat plate-like upper plate member 74 and an inverted L-shaped lower plate member 75 when viewed from the rear. and a portion of the lower plate member 75 having a thickness in the vertical direction of the vehicle are joined together in the vertical direction of the vehicle to form the seat surface portion 711 .

Furthermore, as shown in FIG. 5, the third upper support member 71 has an upper joining portion 712 at a flat portion of the upper plate member 74 on the right side in the vehicle width direction when the upper plate member 74 and the lower plate member 75 are joined together. , and a portion of the lower plate member 75 having a thickness in the vehicle width direction constitutes a lower joint portion 713 .

On the other hand, as shown in FIG. 5, the third lower support member 72 is, for example, a support member made of casting, and is a mounting portion on which the seat surface portion 711 of the third upper support member 71 is mounted and fixed. 721, a mounting portion 722 and a rib portion 723 which are provided vertically from the mounting portion 721 to the vehicle lower side, a vertical wall portion 724 and a rear wall portion 725 which are erected from the mounting portion 721 to the vehicle upper side, and a vertical It is integrally formed with a canopy portion 726 projecting from the wall portion 724 .

As shown in FIGS. 5 to 7, the mounting portion 721 is formed in a substantially flat plate shape having a predetermined thickness in the vertical direction of the vehicle and a substantially flat upper surface. As shown in FIG. 5, a screw hole 721a into which the bolt 73 is screwed is formed on the upper surface of the mounting portion 721 on the rear side of the vehicle in a plan view and on the right side in the vehicle width direction.

In addition, the upper surface of the mounting portion 721 is formed so as to be positioned above the flange portion of the exhaust manifold 5 in the vehicle. More specifically, the upper surface of the mounting portion 721 is located above the vehicle relative to a substantially horizontal imaginary straight line extending in the vehicle width direction through the radial center of the outlet opening of the collecting portion 5c of the exhaust manifold 5. is formed in

As shown in FIGS. 5 and 6, the mounting portion 722 has a substantially flat plate shape having a predetermined thickness in the longitudinal direction of the vehicle and a front surface that contacts the back surface of the upper block 25. It is installed vertically from the bottom of the vehicle. The mounting portion 722 is formed with two bolt insertion holes 722a at a predetermined interval in the vertical direction of the vehicle. ing.

As shown in FIG. 5 , the rib portion 723 has a generally inverted triangular shape in a side view that connects the left lower surface of the mounting portion 721 in the vehicle width direction and the rear surface of the mounting portion 722 .
As shown in FIGS. 5 to 7 , the vertical wall portion 724 has a predetermined thickness in the vehicle width direction, and is erected upward from the left edge of the mounting portion 721 in the vehicle width direction. there is

As shown in FIGS. 5 to 7, the rear wall portion 725 is formed in a substantially triangular shape in side view connecting the rear end of the upper surface of the mounting portion 721 and the rear end of the vertical wall portion 724 .
As shown in FIG. 7, the rear wall portion 725 is formed such that the right end portion in the vehicle width direction is positioned on the vehicle front side of the seat surface portion 711 of the third upper support member 71 in plan view. ing.

As shown in FIGS. 5 to 7 , the eaves portion 726 projects rightward in the vehicle width direction from a position above the vehicle from the seat surface portion 711 of the third upper support member 71 mounted and fixed on the mounting portion 721 . It is
As shown in FIG. 6, the eaves portion 726 has a horizontal portion 726a that faces the upper surface of the mounting portion 721 on the front side of the vehicle and a horizontal portion 726a that faces the upper surface of the mounting portion 721 on the rear side of the vehicle. a front rib 726c erected so as to connect the front end of the horizontal portion 726a to the vertical wall portion 724; It is formed with a rear rib 726d.

As shown in FIG. 6 , the horizontal portion 726 a has a flat plate shape having a thickness in the vertical direction of the vehicle when viewed from the side, and is mounted on the mounting portion 721 and fixed to the seat surface portion 711 of the third upper support member 71 . , is formed at a position above the vehicle with a predetermined distance therebetween.

Furthermore, as shown in FIG. 7 , the horizontal portion 726 a projects with a length in the vehicle width direction in which the tip thereof overlaps the tip of the seat surface portion 711 of the third upper support member 71 in plan view.
More specifically, the horizontal portion 726a projects so that its tip overlaps with the seat surface portion 711 on the left side of the bolt 73 in the vehicle width direction in plan view.

Although not shown in detail, the lower surface of the horizontal portion 726a is gently curved so that the left edge in the vehicle width direction is positioned slightly below the vehicle in a rear view with respect to the right edge in the vehicle width direction. is formed on an inclined surface inclined to In other words, the lower surface of the horizontal portion 726a is formed as an inclined surface that gradually widens as the distance in the vertical direction of the vehicle from the upper surface of the mounting portion 721 increases toward the right side in the vehicle width direction.

As shown in FIG. 6, the inclined portion 726b extends from the horizontal portion 726a toward the rear of the vehicle and upward of the vehicle in a side view. That is, as shown in FIG. 6 , the inclined portion 726b has a rear end positioned above the vehicle with respect to the front end in a side view, so that the vertical interval of the inclined portion 726b with respect to the upper surface of the mounting portion 721 extends toward the rear of the vehicle. It is formed so that it gradually widens as much as possible.

Furthermore, as shown in FIG. 7, the inclined portion 726b protrudes so that its tip has a substantially arc shape in plan view. In other words, the inclined portion 726b is formed in such a shape that, in a plan view, the range of overlapping with the seat surface portion 711 of the third upper support member 71 gradually decreases toward the rear of the vehicle.

Next, an assembly process for connecting the catalyst 6 configured as described above to the engine 2, the transmission 3, and the exhaust manifold 5 will be briefly described.
The catalyst 6 includes the first upper support member 33 of the first catalyst support structure 30, the second upper support member 52 of the second catalyst support structure 50, and the third catalyst support structure 70. It is assumed that the third upper supporting member 71 in 1 is preliminarily joined.

First, the exhaust manifold 5, the first lower support member 31 of the first catalyst support structure 30, and the third lower support member 72 of the third catalyst support structure 70 are pre-fastened and fixed to the engine 2. do.
Further, the second lower support member 51 of the second catalyst support structure 50 is previously fastened and fixed to the transmission 3, and the first lower support member 31 of the first catalyst support structure 30 is The intermediate support member 32 is fastened and fixed.

After that, the catalyst 6 to which the first upper supporting member 33, the second upper supporting member 52, and the third upper supporting member 71 are joined is directed from the rear of the vehicle toward the front of the vehicle, which is the assembly direction, and close to the back of the At this time, the seat surface portion 711 of the third upper support member 71 is inserted from the rear side of the vehicle to the front side of the vehicle between the mounting portion 721 and the eaves portion 726 of the third lower support member 72 . approaches the back of the engine 2.

In this manner, by inserting the third upper support member 71 between the mounting portion 721 and the eaves portion 726 of the third lower support member 72, the eaves portion of the third lower support member 72 is 726 guides the movement of the third upper support member 71 forward of the vehicle. That is, the eaves portion 726 of the third lower support member 72 guides the movement of the catalyst 6 forward of the vehicle.

Then, the positions of the flange portion of the catalyst 6 and the flange portion of the exhaust manifold 5 are aligned, and the first upper support member 33, the second upper support member 52, and the third upper support member 71 are respectively provided as intermediate supports. It rests on the member 32 , the second lower support member 51 and the third lower support member 72 .

At this time, since the center of gravity of the catalyst 6 is located at the rear portion on the right side in the vehicle width direction, the radial center of the outlet opening in the collecting portion 5c of the exhaust manifold 5 and the upper surface portion of the second lower support member 51 are connected. The catalyst 6 starts to rotate so that the first catalyst 61 moves upward with respect to the vehicle with the virtual straight line as the axis of rotation.

When the catalyst 6 starts to rotate, the seat surface portion 711 of the third upper support member 71 comes into contact with the eaves portion 726 of the third lower support member 72 from below the vehicle, so that the rotation of the catalyst 6 is restricted. . Thereby, the gap between the flange portion of the catalyst 6 and the flange portion of the exhaust manifold 5 can be maintained when they are aligned. Then, the catalyst 6 and the exhaust manifold 5 are connected by tightening the V clamp 10 in the circumferential direction while maintaining the gap between the flange portion of the catalyst 6 and the flange portion of the exhaust manifold 5 .

As described above, the exhaust manifold 5 through which the exhaust gas emitted by the engine 2 of the vehicle 1 flows down, the catalyst 6 connected to the downstream flange portion of the exhaust manifold 5, and the third catalyst support supporting the catalyst 6 The exhaust system 4 of the engine 2 having a structure 70 includes a third upper support member 71 in which the third catalyst support structure 70 is arranged on the catalyst 6 and a vehicle body of the third upper support member 71 . A third lower support member 72 is arranged below and fastened and fixed to the engine block 21, and the third lower support member 72 and the third upper support member 71 are mounted and fixed. and a third upper support member 71 mounted on the mounting portion 721, and a predetermined space above the mounting portion 721 with respect to the vehicle so that the tip end thereof overlaps with the mounting portion 721 in a plan view. and an eaves portion 726 which is substantially plate-shaped in plan view and protrudes from a position separated from the , and the direction in which the third upper support member 71 is inserted between the mounting portion 721 and the eaves portion 726 is the assembly direction. , the overhanging portion 726 is formed such that the distance in the vertical direction of the vehicle with respect to the mounting portion 721 gradually increases toward the opposite direction (vehicle rearward) opposite to the assembling direction. It is possible to satisfy both the regulation and the improvement of the assembling property of the catalyst 6 to the exhaust manifold 5 .

Specifically, when the catalyst 6 starts to rotate, the third upper support member 71 that starts to rotate integrally with the catalyst 6 contacts the eaves portion 726 provided on the third lower support member 72 . Thus, the exhaust device 4 of the engine 2 can restrict the rotation of the catalyst 6 .
As a result, the exhaust system 4 of the engine 2 suppresses the formation of a gap between the flange portion of the exhaust manifold 5 and the catalyst 6 due to the rotation of the catalyst 6, thereby connecting the flange portion of the exhaust manifold 5 and the catalyst 6. can be made easier.

Furthermore, since the eaves portion 726 is formed so that the tip thereof overlaps with the third upper support member 71 mounted on the mounting portion 721 in a plan view, the exhaust device 4 of the engine 2 is formed as an eaves. A decrease in the visibility of the mounting portion 721 due to the portion 726 can be suppressed. Therefore, the exhaust device 4 of the engine 2 can prevent the mounting of the catalyst 6 and bolt fastening from being hindered by the eaves portion 726 .

In addition, the eaves portion 726 is formed so that the distance in the vertical direction of the vehicle with respect to the mounting portion 721 gradually increases toward the direction opposite to the assembling direction (vehicle rearward). The vehicle vertical direction interval with respect to the mounting portion 721 is formed so as to gradually narrow toward the front).

Therefore, the exhaust device 4 of the engine 2 can secure a large insertion opening for the third upper support member 71, and the eaves portion 726 prevents the movement of the third upper support member 71 in the assembly direction (vehicle front). can guide you. As a result, the exhaust system 4 of the engine 2 can easily insert the third upper support member 71 between the mounting portion 721 and the eaves portion 726 even if the catalyst 6 is heavy. .
Therefore, the exhaust system 4 of the engine 2 can both restrict the rotation of the catalyst 6 and improve the ease of assembly of the catalyst 6 to the exhaust manifold 5 .

Further, since the mounting portion 721 of the third lower support member 72 is formed in a shape positioned above the vehicle with respect to the flange portion of the exhaust manifold 5 , the exhaust system 4 of the engine 2 can be mounted on the catalyst 6 . Rotation can be reliably regulated, and the assembling property of the catalyst 6 to the exhaust manifold 5 can be further improved.

Specifically, for example, in the case of the third lower support member 72 in which the mounting portion 721 is positioned below the vehicle from the flange portion of the exhaust manifold 5 , the catalyst 6 may reduce the visibility of the mounting portion 721 . There is

On the other hand, by using the third lower support member 72 in which the mounting portion 721 is positioned above the vehicle from the flange portion of the exhaust manifold 5 , the exhaust device 4 of the engine 2 is mounted on the catalyst 6 . 721 visibility deterioration can be prevented.

Further, the exhaust system 4 of the engine 2 allows the catalyst 6 to rotate with the flange portion of the exhaust manifold 5 as one end of the rotation axis. As compared with the third lower support member 72, which is used as the third lower support member 72, it can be regulated early and reliably.

Therefore, in the exhaust system 4 of the engine 2, the rotation of the catalyst 6 can be reliably restricted by the third lower support member 72 in which the mounting portion 721 is located above the flange portion of the exhaust manifold 5 in the vehicle. The mountability of the catalyst 6 to the exhaust manifold 5 can be further improved.

The catalyst 6 is composed of a first catalyst 61 connected to the flange portion of the exhaust manifold 5 and a second catalyst 62 connected to the first catalyst 61. The first catalyst 61 and the second catalyst 62 are connected to each other. , the exhaust device 4 of the engine 2 is connected in a substantially L-shape in plan view, so that even if the catalyst 6 has a center of gravity positioned at a disadvantageous position with respect to rotation, the rotation of the catalyst 6 is restricted and It is possible to improve the assembling property of the catalyst 6 with respect to the exhaust manifold 5 at the same time.

Specifically, since the first catalyst 61 and the second catalyst 62 are connected in a substantially L-shape in plan view, the position of the center of gravity of the catalyst 6 is located at a disadvantageous position with respect to rotation. .
Therefore, by providing the eaves portion 726 on the third lower support member 72, the exhaust system 4 of the engine 2 can be adjusted even if the catalyst 6 has a center of gravity positioned at a disadvantageous position with respect to rotation. rotation can be regulated.

Furthermore, since the exhaust system 4 of the engine 2 can support the third upper support member 71 by the eaves portion 726 of the third lower support member 72, the state of the third upper support member 71 in which rotation is restricted can be stabilized. Therefore, the exhaust device 4 of the engine 2 can easily fasten the third upper support member 71 and the third lower support member 72 .
Therefore, even if the center of gravity of the exhaust system 4 of the engine 2 is located at a position disadvantageous to the rotation, the rotation of the catalyst 6 is restricted and the ease of assembly of the catalyst 6 to the exhaust manifold 5 is improved. can be compatible.

In addition, since the flange portion of the exhaust manifold 5 and the catalyst 6 are connected by the V clamp 10, the exhaust system 4 of the engine 2 is more efficient than the case where the flange portion of the exhaust manifold 5 and the catalyst 6 are fastened with bolts. Therefore, the flange portion of the exhaust manifold 5 and the catalyst 6 can be connected with a reduced number of parts.

Furthermore, the exhaust system 4 of the engine 2 can prevent the gap between the flange portion of the exhaust manifold 5 and the catalyst 6 from expanding due to the rotation of the third upper support member 71. can be facilitated.

Therefore, in the exhaust system 4 of the engine 2, by connecting the flange portion of the exhaust manifold 5 and the catalyst 6 with the V clamp 10, an increase in the number of parts is suppressed and the assembling of the catalyst 6 to the exhaust manifold 5 is further improved. You can definitely improve.

In correspondence with the configuration of this invention and the above-described embodiments,
The downstream end of the exhaust manifold of the present invention corresponds to the flange portion of the exhaust manifold 5 of the embodiment,
and so on,
the catalyst support structure corresponds to the third catalyst support structure 70,
The upper support member corresponds to the third upper support member 71,
The powertrain corresponds to the engine 2 and the transmission 3,
The lower support member corresponds to the third lower support member 72,
The assembly direction is from the rear of the vehicle to the front of the vehicle, and the opposite direction is from the front of the vehicle to the rear of the vehicle.
The present invention is not limited to the configurations of the above-described embodiments, and many embodiments can be obtained.

For example, in the above-described embodiment, the exhaust system 4 of the engine 2 has been described using the horizontally mounted engine 2. However, the present invention is not limited to this. may be
In addition, although the first catalyst support structure 30 is composed of the first lower support member 31, the intermediate support member 32, and the first upper support member 33, the present invention is not limited to this. The support member 31 and the intermediate support member 32 may be integrally formed to form a first lower support member.

Although the catalyst 6 is mounted in the direction from the rear of the vehicle to the front of the vehicle, it is not limited to this. , an appropriate direction may be used as the assembly direction. For example, the assembly direction may be the direction from the left in the vehicle width direction to the right in the vehicle width direction. At this time, the eaves portion 726 of the third lower support member 72 is formed so as to have a shape corresponding to the assembly direction.

Also, although the third catalyst support structure 70 has the eaves portion 726, the present invention is not limited to this. It may be a configuration having.
Further, although the flange portion of the exhaust manifold 5 and the flange portion of the catalyst 6 are connected by a V clamp, the structure is not limited to this, and a structure in which they are fastened and fixed by a bolt or the like may be used.

Also, the first catalyst support structure 30 and the third catalyst support structure 70 are connected to the rear surface of the engine 2, and the second catalyst support structure 50 is connected to the converter housing 3a of the transmission 3. However, the catalyst support structure is not limited to this, and may be, for example, a catalyst support structure connected to an appropriate vehicle body frame member that constitutes the vehicle body.

The first catalyst support structure 30 supports the right rear portion of the catalyst 6 in the vehicle width direction, the second catalyst support structure 50 supports the left rear portion of the catalyst 6 in the vehicle width direction, and the third catalyst support structure 50 supports the left rear portion of the catalyst 6 in the vehicle width direction. Although the support structure 70 is configured to support the left front portion in the vehicle width direction of the catalyst 6, it is not limited to this, and may be configured to support an appropriate position of the catalyst 6 as long as the catalyst 6 can be supported. good.

DESCRIPTION OF SYMBOLS 1... Vehicle 2... Engine 3... Transmission 4... Exhaust system 5... Exhaust manifold 6... Catalyst 10... V clamp 61... First catalyst 62... Second catalyst 70... Third catalyst support structure 71... Third upper side Supporting member 72 Third lower supporting member 721 Placement portion 726 Eaves portion

Claims (4)

an exhaust manifold for flowing down exhaust gas emitted by a vehicle engine;
a catalyst connected to a downstream end of the exhaust manifold;
An engine exhaust system comprising a catalyst support structure that supports the catalyst,
The catalyst support structure is
an upper support member disposed on the catalyst;
It is arranged below the vehicle of the upper support member and is composed of a lower support member fastened and fixed to the power train or the vehicle body,
The lower support member is
a mounting portion having a flat surface on which the upper support member is mounted and fixed;
A rough plate projecting from a position spaced above the mounting portion by a predetermined distance from the mounting portion so that the top end of the upper support member placed on the mounting portion overlaps with the mounting portion in plan view. with a shaped eaves part,
The assembly direction is the direction in which the upper support member is inserted between the mounting portion and the eaves portion,
The eaves part is
1. An exhaust system for an engine, which is formed so that the distance in the vertical direction of the vehicle with respect to the mounting portion is gradually widened in the opposite direction to the assembly direction. The mounting portion of the lower support member,
2. An exhaust system for an engine according to claim 1, wherein said end of said exhaust manifold is formed in a shape positioned above said vehicle. The catalyst is
a first catalyst coupled to the end of the exhaust manifold;
and a second catalyst connected to the first catalyst,
The first catalyst and the second catalyst are
3. An exhaust system for an engine according to claim 1 or 2, which is connected in a substantially L-shape in plan view. 4. The engine exhaust system according to claim 1, wherein said end of said exhaust manifold and said catalyst are connected by a V-clamp.

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