JP3521714B2 - Exhaust system for V-type internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system for a V-type internal combustion engine, and more particularly to an exhaust system having a structure in which exhaust pipes of left and right banks are joined together.

[0002]

2. Description of the Related Art Conventionally, in a V-type internal combustion engine, as an exhaust device having a structure in which exhaust pipes of both banks join, there is one disclosed in Japanese Patent Laid-Open Publication No. 4-350321. The exhaust pipes of both banks of the horizontal V-type engine are
After extending once in the direction opposite to each other, the exhaust pipes of the vehicle rear bank reverse their directions on a substantially horizontal plane so that the exhaust pipes of both banks extend toward the rear of the vehicle together.
It is a structure that merges on the downstream side. Here, the exhaust pipes of both banks are arranged side by side in parallel in the left-right direction of the vehicle, and after the exhaust pipes of the rear bank are extended toward the front of the vehicle, the left side of the vehicle The exhaust pipe of the front bank is configured to bypass the exhaust pipe of the rear bank from the right side of the vehicle and reach the confluence portion, while the direction of the exhaust pipe of the front bank is reversed.

[0003]

According to the above-mentioned conventional exhaust system, the exhaust pipe of the rear bank which is biased to the left side of the vehicle and the exhaust pipe of the front bank which is biased to the right side of the vehicle. Since it is a configuration that merges with, when attempting to merge at a position close to the engine, the merging portion of the exhaust pipe becomes an obtuse angle, which causes interference in the exhaust flow,
There was a problem of loss of output and torque.

Further, since the exhaust pipe of the front bank bypasses the exhaust pipe of the rear bank and circumvents the exhaust pipe, there is a problem that the exhaust loss in the front bank is large due to the bending of the exhaust pipe. Further, when the exhaust pipe of the rear bank and the exhaust pipe of the front bank are arranged in parallel to each other in the left-right direction of the vehicle as in the conventional exhaust system, the exhaust pipe is arranged in the left-right direction of the vehicle. There is also a problem that the required space becomes large, and it becomes necessary to sharply cut the oil pan of the engine to create space and to sacrifice the minimum ground clearance of the vehicle.

Further, when a pre-catalyst is to be provided for each bank in addition to the main catalyst (underfloor catalyst), in the above conventional exhaust system, the pre-catalyst is particularly installed below the engine with respect to the exhaust pipe of the rear bank. There is no space for mounting the catalyst, and there is a problem in that it is necessary to secure a further space for mounting the pre-catalyst. The present invention has been made in view of the above problems, and it is possible to combine the exhausts of both banks with little interference, and the exhaust pipe can be configured as straight as possible to reduce exhaust loss and space efficiency. It is an object of the present invention to provide an excellent exhaust system for a V-type internal combustion engine.

[0006]

Therefore, the invention according to claim 1 is an exhaust system for a V-type internal combustion engine having two left and right banks, wherein the exhaust pipe of each of the left and right banks is connected to the engine. State in which the exhaust pipes of one bank are reversed in a substantially horizontal plane, and the exhaust pipes of the left and right banks are substantially vertically adjacent to each other.
Both of them are extended in one direction and joined at the downstream merging portion .

According to this structure, the exhaust pipe of the other bank extends in one direction through the lower side of the engine.
The exhaust pipes of one bank are once extended to the other bank, and then are turned to the above-mentioned one direction by reversing the direction on the horizontal plane at the lower part of the engine. The pipes meet downstream. Here, the exhaust pipes of both banks are
On the upstream side of the merging part, one side of the upper side
It will be extended toward you.

According to a second aspect of the present invention, there are two left and right banks.
An exhaust device for a V-type internal combustion engine, comprising:
Connect the exhaust pipes of the right bank to each other below the engine.
After extending in opposite directions, the exhaust pipe of one bank
To reverse the direction on a substantially horizontal plane to exhaust the left and right banks
Extend the pipes together in one direction at the downstream confluence
And merging the cell configuration, and an exhaust pipe of one bank to reverse the direction, and configured to be disposed below the space of the exhaust pipe of the other bank at upstream side of the merging portion. According to such a configuration, the exhaust pipe of the other bank extends in one direction in the space above the exhaust pipe of the one bank which is provided with the direction reversed.

In the third aspect of the invention, the left and right banks are the same.
After extending the exhaust pipes in the direction facing each other with the output shaft offset at the bottom of the engine, place the exhaust pipes of one bank above and below the exhaust pipes of the other bank. Set the direction on a substantially horizontal plane so that
After reversing, the exhaust pipes of the left and right banks are extended in one direction in a state of being substantially vertically adjacent to each other after the reversal , and the downstream side
The merging portion is used for merging.

According to this structure, the exhaust pipe of one bank is vertically and horizontally offset with respect to the exhaust pipe of the other bank before reversing the direction, but after reversing, the exhaust pipe of the other bank is reversed. The exhaust pipes substantially overlap with each other in the vertical direction, and the both exhaust pipes extend in one direction in a state of being substantially parallel to each other and join together. In the invention described in claim 4,
The exhaust pipe of one bank according to the configuration of claim 3,
I will wrap around to the position where it overlaps below the exhaust pipe of one bank.
As described above, the direction is reversed on a substantially horizontal plane. Such structure
According to Cheng, the exhaust pipe of one bank reverses direction
The front is off vertically and horizontally with respect to the exhaust pipe of the other bank
Although it is set, after reversing, the exhaust pipe of the other bank
Both exhaust pipes are almost vertically aligned so that they are almost vertically overlapped.
In such a state, they are extended in one direction and merge. Claim 5
In the invention described above, a catalytic converter is interposed immediately before the portion where the direction of the exhaust pipe of the one bank is reversed, and the exhaust pipes of the left and right banks are adjacent to each other beside the catalytic converter. It was configured to extend in one direction.

According to this structure, the catalytic converter dedicated to one bank is interposed in a portion immediately before the exhaust pipe of the one bank reverses its direction, that is, in a lower portion of the engine,
An exhaust pipe of one bank and an exhaust pipe of the other bank extending in one direction extend in parallel to each other along the side of the catalytic converter. According to a sixth aspect of the present invention, the catalytic converter installed in the exhaust pipe of the one bank is an oval cross-section catalytic converter, and the longitudinal direction of the oval cross section is substantially vertical. And

According to this structure, the catalytic converter having an oval cross section is disposed in the exhaust pipe so that the longitudinal direction of the oval cross section is substantially vertical and a space in the lateral direction is secured. The exhaust pipe of one bank and the exhaust pipe of the other bank extending in one direction are extended substantially vertically. In the invention according to claim 7 , among the exhaust pipes of the left and right banks that extend in one direction together in the state of being adjacent to each other in the substantially vertical direction, the exhaust pipe of the other bank is the exhaust pipe of the one bank. The structure is such that the catalyst converter is extended closer to the catalytic converter.

According to this structure, in the structure in which the two exhaust pipes are extended substantially vertically in parallel to the lateral side of the catalytic converter, the exhaust pipes are extended linearly more than the exhaust pipes which are inverted in direction. The size of the piping space containing the catalyst is reduced while ensuring the radius of curvature of the exhaust pipe for reversing the direction by allowing the exhaust pipe to be processed to pass closer to the catalytic converter.

According to an eighth aspect of the present invention, the portion of the exhaust pipe of the other bank that extends in the one direction is located upstream of the portion of the exhaust pipe of the one bank that substantially overlaps with the exhaust pipe. A configuration is adopted in which a catalytic converter is provided on the side. According to such a configuration, the catalytic converter dedicated to the other bank is arranged below the engine, and the exhaust pipe of one bank and the exhaust pipe of the other bank whose directions are reversed are substantially vertically arranged on the downstream side of the catalytic converter. They are in a parallel state and extend in one direction.

According to a ninth aspect of the present invention, the catalytic converter installed in the exhaust pipe of the other bank is an oval cross-section catalytic converter, and the longitudinal direction of the oval cross section is substantially horizontal. It is configured to be. According to this structure, the longitudinal direction of the oval cross section is set to be substantially horizontal, so that the height direction of the catalytic converter is shortened and the catalytic converter is arranged below the engine.

According to a tenth aspect of the present invention, the oil pan of the V-type internal combustion engine comprises a deep bottom portion and a shallow bottom portion in the output shaft direction, and the exhaust pipes of the left and right banks extend below the shallow bottom portion. It was configured to be installed. With this configuration, the oil pan of the engine is divided into a deep bottom portion and a shallow bottom portion in the output shaft direction, and the exhaust pipes of both banks extend to the lower side of the shallow bottom portion corresponding to the portion where the lower side of the engine is hollowed. Set up.

According to an eleventh aspect of the present invention, the V-type internal combustion engine is mounted on a vehicle with its output shaft aligned with the lateral direction of the vehicle, and the left and right banks face each other in the longitudinal direction of the vehicle. One bank is a vehicle rear side bank, the other bank is a vehicle front side bank, and the exhaust pipes of the left and right banks are joined so that the one direction is the vehicle rear side.

According to this structure, in the horizontal V-type engine, the exhaust pipe of the bank on the rear side is once extended toward the front of the vehicle, and then the direction of the exhaust pipe of the bank on the front side is reversed to the exhaust pipe of the bank on the front side. At the same time, it is extended toward the rear of the vehicle.

[0019]

According to the invention described in claim 1, since the exhaust pipe of the other bank does not bypass the exhaust pipe of the one bank on a horizontal plane, the exhaust pipe of the other bank can be linearly extended. In addition to being possible, it is possible to reduce the piping space required in the output shaft direction, and it becomes easy to secure a space for reversing the direction of the exhaust pipe of one bank, and with a gentle radius of curvature. It is possible to reverse the direction, making it easier to equalize the exhaust pipes of both banks , and further, to the exhaust pipes of each bank on the upstream side of the merging section.
Are arranged almost vertically adjacent to each other in parallel,
The angle at which both exhaust pipes intersect can be made acute,
As a result, the output interference is suppressed and the output and torque are improved.
There is an effect that can be achieved . According to the second aspect of the invention, the exhaust pipe of one bank, which requires more space in the output shaft direction for reversing the direction, is disposed below the exhaust pipe of the other bank which can be linearly extended. Since it is extended to the side, the space required for passing the exhaust pipe may be narrower toward the upper side.For example, when securing the space for hollowing the lower side of the engine to pass the exhaust pipe, This has the effect of narrowing the width and making the volume (oil pan volume) hollowed to provide the exhaust pipe space as small as possible.

According to the third aspect of the present invention, the exhaust pipes of one bank, which are extended together in one direction after the exhaust pipes of one bank are reversed in direction, are arranged substantially vertically adjacent to each other in parallel. Therefore, it is possible to make the angle at which the two exhaust pipes intersect at the confluent portion an acute angle, thereby suppressing the occurrence of exhaust interference and improving the output and torque, while the degree of freedom of the installation position of the confluent portion. Therefore, there is an effect that it does not affect the securing of the length of the flexible tube provided downstream of the merging portion. According to the invention of claim 4,
The angle at which both exhaust pipes intersect at the confluence should be an acute angle.
Therefore, it is possible to suppress the occurrence of exhaust interference and
While it is possible to improve the level of flexibility,
High, flexible tube length downstream of the confluence
Has the effect of not affecting
It is necessary to pass the exhaust pipe under the engine.
The required space can be narrower toward the top, and the exhaust pipe can be passed through.
To secure space, increase the width in the direction of the output shaft toward the top.
Volume to be narrowed and hollowed to provide exhaust pipe space
The effect is that the (oil pan volume) can be minimized.
It

According to the fifth aspect of the present invention, the catalytic converter (pre-catalyst) dedicated to one bank is arranged below the engine to avoid heat damage due to the catalyst and to be located relatively close to the engine. Converter will be placed,
There is an effect that the catalyst performance can be improved.
According to the sixth aspect of the present invention, the catalytic converter is vertically inserted in the exhaust pipe of one bank whose direction is reversed, and the exhaust pipes of both banks extend in one direction across the catalytic converter. Since it is installed, it is possible to save the required space in the output shaft direction where the catalytic converter is installed, and to effectively use the space where the exhaust pipes of both banks do not overlap vertically as the installation space for the catalytic converter. There is an effect that can be done.

According to the invention of claim 7, the piping space including the catalytic converter and the exhaust pipes of both banks extending in one direction can be made as small as possible.
There is an effect that it can be effectively covered with a heat shield so as to suppress heat damage to peripheral parts. According to the invention described in claim 8, the catalytic converter (pre-catalyst) dedicated to the other bank is arranged on the lower side of the engine, and the catalytic converter is arranged at a position relatively close to the engine while avoiding heat damage due to the catalyst. As a result, there is an effect that the catalyst performance can be improved.

According to the ninth aspect of the invention, the longitudinal direction of the oval cross section is set to be substantially horizontal, so that the height of the catalytic converter is reduced, and the lower side of the engine is placed at a high position as close to the engine as possible. It becomes possible to pass the exhaust pipe of the bank of the above, and it becomes possible to secure a sufficient ground clearance in this part. According to the invention of claim 10 ,
Since the exhaust pipes of both banks can be extended to the lower side of the engine in a space-efficient manner, a deep bottom portion and a shallow bottom portion are provided in the oil pan, and the exhaust pipes of both banks are passed under the shallow bottom portion. This has the effect of reducing the volume of the oil pan as much as possible.

According to the eleventh aspect of the present invention, in the horizontal V-type engine, the piping space can be saved when the exhaust pipes of each bank are joined and extended to the rear of the vehicle, and
This has the effect of reducing exhaust resistance.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of an exhaust device for a V-type internal combustion engine according to an embodiment. In the present embodiment, the V-type internal combustion engine is laterally placed on a vehicle with its output shaft aligned with the left-right direction of the vehicle. The left and right banks face each other in the front-rear direction of the vehicle. In the present embodiment, one bank shown in claim 1 corresponds to the vehicle rear bank (engine right bank), and the other bank corresponds to the vehicle front bank (engine left bank). .

In FIG. 1, exhaust manifolds 1f and 1r are provided in the left and right banks (front and rear banks) of a horizontal V-type internal combustion engine (not shown). The exhaust pipes 2 and 3 connected to the collecting portion of the exhaust manifolds 1f and 1r are
The pre-catalyst 4, which extends downward and is arranged below the engine 4,
Connected to 5. The exhaust pipes 6 and 7 respectively connected to the outlet portions of the pre-catalysts 4 and 5 are extended in the directions facing each other, and then the exhaust pipes 7 reverse their directions, and both of them are rearward (one direction) of the vehicle. The merging portion 8 on the downstream side.
Join at. A flexible tube 9 is connected immediately after the merging portion 8.

FIG. 2 is a diagram showing an exhaust system of the entire vehicle to which the present embodiment is applied. An underfloor catalyst (main catalyst) 10 and a sub-muffler 11 are provided in an exhaust pipe downstream of the flexible tube 9. ， The main muffler 12 is installed. 3 is a side view of the exhaust device shown in FIG. 1, FIG. 4 is a top view, FIG. 5 is a sectional view taken along line AA shown in FIG. 1, and FIG. 6 is a sectional view taken along line BB shown in FIG. The exhaust device in the present embodiment will be described in detail with reference to these.

3 and 4, the arrow F direction indicates the front of the vehicle, the arrow R direction indicates the rear of the vehicle, and as shown in FIG. 3, a V type having two left and right banks 20f, 20r. The internal combustion engine 20 is horizontally arranged such that the two banks 20f and 20r face each other in the front-rear direction of the vehicle with 20f as a front bank and 20r as a rear bank. Each exhaust manifold 1f, 1
Each r has a branch portion connected to the exhaust ports of the plurality of cylinders forming each bank 20f, 20r.

The pre-catalyst 4 for the front bank 20f is formed in an oval cross section, and is arranged below the engine 20 with the longitudinal direction of the oval cross section being substantially horizontal. Engine 20 oil pan
As shown in FIG. 5, 21 is a shallow bottom portion 21a on the left side of the vehicle,
The pre-catalyst 4 is formed immediately below the front bank 20f of the shallow bottom portion 21a and is located at the upper right corner (a space in FIG. 5) avoiding the center member 22. Is the right side of the vehicle).

By arranging the pre-catalyst 4 horizontally and directly below the shallow bottom portion 21a, the exhaust path of the front bank is set to the shallow bottom portion 21a.
It can be a straight path that passes directly below. And
One end of the exhaust pipe 2 is connected to the exhaust manifold 1f, is extended downward, is curved toward the rear of the vehicle, and is connected to the inlet of the pre-catalyst 4 at the other end.

The exhaust pipe 6, one end of which is connected to the outlet of the pre-catalyst 4, extends substantially linearly toward the rear of the vehicle and reaches the merging portion 8. On the other hand, the pre-catalyst 5 for the rear bank 20r is also formed in an oval cross section, but its longitudinal direction is substantially vertical and is offset to the right side of the vehicle with respect to the pre-catalyst 4 for the front bank 20f ( (See FIG. 4) and so as to avoid the drive shaft 23, the drive shaft 23 is disposed in a portion near the rear bank 20r below the shallow bottom portion 21a.

Therefore, both of the pre-catalysts 4 and 5 are arranged under the engine 20, which avoids heat damage to the pre-catalysts 4 and 5 and is located relatively close to the engine 20. The catalyst performance can be improved by disposing the pre-catalyst 5 for the rear bank 20r, in particular, avoiding a thermal influence on the parts arranged between the engine 20 and the dash panel 24. it can. Further, by vertically arranging the pre-catalyst 5 for the rear bank 20r, the lateral protrusion can be reduced, and a space for passing the exhaust pipes 6 and 7 beside the pre-catalyst 5 can be secured.

The exhaust pipe 3 is connected to the exhaust manifold 1r at one end, extends downward, and is connected to the inlet of the precatalyst 5 at the other end. One end of an exhaust pipe 7 is connected to the outlet of the pre-catalyst 5 with a downward offset, and the exhaust pipe 7 is located on the right side of the vehicle with respect to the exhaust pipe 6 in the vicinity of the connection portion to the pre-catalyst 5. After being offset (see FIG. 4) and extending toward the front of the vehicle in a space below the exhaust pipe 6 (see FIG. 3), the direction is reversed in an arc shape on a substantially horizontal plane before the precatalyst 4. Then, it goes around to a position below the exhaust pipe 6, and then passes through the left side of the pre-catalyst 5 in a parallel state where the exhaust pipe 6 and the exhaust pipe 6 overlap with each other in a parallel state, and extends to the merging portion 8 at the rear of the vehicle (see FIG. 6).

Immediately before the confluence portion 8, exhaust pipes 6 and 7 are formed so as to approach each other substantially symmetrically and reach the confluence portion, and a flexible tube 9 is connected immediately after the confluence portion 8. . In contrast to the configuration in which the exhaust pipe 7 and the exhaust pipe 6 that are reversed in direction on a substantially horizontal plane are arranged in parallel in the lateral direction, the exhaust pipe 7 and the exhaust pipe 6 that are reversed in direction on a substantially horizontal plane as in the present embodiment are provided. With the structure of stacking vertically, even if the space is the same in the lateral direction, a large space can be taken when reversing the direction of the exhaust pipe 7 as long as it does not interfere with the exhaust pipe 6, so the direction should be reversed with a large radius of curvature. You can

Further, the lower space of the shallow bottom portion 21a has a larger width in the vehicle left-right direction (engine output axis direction) toward the lower side, so that the exhaust pipe 7 is oriented in the space below the exhaust pipe 6 as described above. If the structure is reversed, the direction can be reversed in the space portion having a larger width, and the exhaust pipe 7 can be reversed with a larger radius of curvature. As a result, the flow of exhaust gas becomes smooth and exhaust pressure loss can be reduced.

Further, the pre-catalyst 5 is offset to the right side of the vehicle with respect to the pre-catalyst 4, and the exhaust pipe 7 after the direction is reversed.
Is extended below the exhaust pipe 6, the exhaust pipe 6 after the pre-catalyst 4 can be extended linearly, and exhaust resistance can be reduced. On the other hand, in the merging portion 8, the exhaust pipes 6,
Although the exhaust pipes 7 and 7 are turned toward each other, the exhaust pipes 6 and 7 extend substantially vertically in parallel with each other on the upstream side of the merging portion 8, so that the merging portion 8 has 6 and 7 will intersect at an acute angle. Therefore, the confluence section 8
The occurrence of exhaust interference in the engine can be suppressed, and the output and torque can be improved.

Further, the exhaust pipe 7 is reversed in direction and the exhaust pipe 6
Since it is extended in parallel with the rear of the vehicle, the merging portion 8 can be located further rearward than the portion directly below the engine 20, whereby the exhaust pipe length of each bank before merging can be increased and the effect of the exhaust inertia effect can be obtained. It is possible to improve the intake charge efficiency, which also improves the output and torque.
Further, according to the above exhaust pipe layout, the exhaust pipe 7 is
Since the direction is reversed substantially directly below 20, the exhaust pipe length for each bank can be made equal, exhaust interference can be prevented, and exhaust noise of exhaust can be reduced.

Further, as shown in FIG. 6, if the pre-catalyst 5 for the rear bank 20r and the exhaust pipes 6 and 7 passing beside it are integrally covered with the heat shield plate 25, heat to the peripheral parts can be reduced. It is possible to prevent harm. Here, it is desired that the exhaust pipe 7 be reversed in direction with a radius of curvature as large as possible as described above, whereby the distance between the precatalyst 5 and the exhaust pipe 7 after the direction is reversed is regulated. But,
As shown in FIG. 6, the upper exhaust pipe 6 can be brought closer to the side of the pre-catalyst 5, whereby the volume covered by the heat shield plate 25, that is, the piping space can be reduced, and the running wind can be reduced. Exhaust from the front bank, which tends to be cooled by
The pre-catalyst 5 heats up as much as possible due to the exothermic action of the pre-catalyst 5, whereby the exhaust purification performance of the underfloor catalyst can be improved.

Further, since the exhaust pipes 6 and 7 reach the merging portion 8 in a parallel state in which they are substantially vertically adjacent to each other, the position of the merging portion 8 is not restricted by the exhaust pipe 3 or the like. The length of the engine can be secured, so that the propagation of engine vibration to the vehicle body can be reduced and the strength and life of the exhaust pipe can be improved. For example, in the case where the exhaust pipe 7 of the rear bank is turned around to the left side of the vehicle and the exhaust pipe 6 of the front bank is extended around the right side of the vehicle on the same horizontal plane, Since the exhaust pipes 6 and 7 join together so as to sandwich the exhaust pipe 3, it is necessary to provide a merging portion closer to the rear side of the vehicle than the exhaust pipe 3, whereby the length of the flexible tube 9 is increased. Although there is a possibility that the flexible tube 9 is regulated, the length of the flexible tube 9 can be secured sufficiently and sufficiently in the present embodiment because there is no limitation as described above.

In the above embodiment, the precatalysts 4 and 5 are used.
However, the pre-catalysts 4 and 5 may be omitted. Further, the pre-catalysts 4 and 5 may have a circular cross section.

[Brief description of drawings]

FIG. 1 is a perspective view showing an exhaust device according to an embodiment.

FIG. 2 is a schematic diagram showing an exhaust system of the entire vehicle according to the embodiment.

FIG. 3 is a side view showing the exhaust device according to the embodiment.

FIG. 4 is a top view showing the exhaust device according to the embodiment.

5 is a cross-sectional view taken along the line AA in FIG.

FIG. 6 is a sectional view taken along line BB in FIG.

[Explanation of symbols]

1f, 1r exhaust manifold 2, 3, 6, 7 exhaust pipe 4,5 pre-catalyst 8 confluence section 9 Flexible tube 10 Underfloor catalyst (main catalyst) 11 Sub muffler 12 Main muffler 20 V internal combustion engine 20f, 20r bank 21a Shallow bottom 21b deep bottom

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-350321 (JP, A) JP-A-7-238828 (JP, A) JP-A-7-4237 (JP, A) JP-A-6- 93855 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F01N 7/10 F01N 3/28 F02B 67/00

Claims (11)

(57) [Claims] 1. An exhaust system for a V-type internal combustion engine having two left and right banks, wherein exhaust pipes of each of the left and right banks are extended below the engine in mutually facing directions. , The exhaust pipes of one bank are reversed in direction on a substantially horizontal plane, and the exhaust pipes of the left and right banks are extended in one direction in a state where they are substantially vertically adjacent to each other and merge at a downstream merging portion. An exhaust device for a V-type internal combustion engine having a configuration. 2. A V-type internal combustion engine having two left and right banks.
Exhaust device of the Seki, the exhaust pipe of each of the left and right banks under the engine
After extending them in the direction facing each other,
The exhaust pipe is turned over in a substantially horizontal plane to
Both exhaust pipes are extended in one direction to merge downstream.
A structure for combining at parts, and, V-type internal combustion, characterized in that the exhaust pipe of one bank to reverse the direction, and disposed below the space of the exhaust pipe of the other bank at upstream side of the merging portion Exhaust system of the engine. 3. A V-type internal combustion engine having two left and right banks
A exhaust system Seki, the exhaust pipe of each of the left and right banks, after extending in a direction opposite to each other in a state of being offset in the output direction at the lower side of the engine, the exhaust pipe of one of the banks, The direction is inverted on a substantially horizontal plane so as to wrap around the exhaust pipe of the other bank in a vertically overlapping position , and after the inversion, the exhaust pipes of the left and right banks are oriented in one direction with both being vertically adjacent. It is possible to extend it and join it at the merging part on the downstream side.
A characteristic V-type internal combustion engine exhaust system. 4. A V-type internal combustion engine having two left and right banks.
Exhaust device of the Seki, the exhaust pipe of each of the left and right banks under the engine
Those facing each other with the output axis offset
After extending it in one direction, connect the exhaust pipe of one bank to the other
The exhaust pipe of the
The direction is reversed on the horizontal plane, and after the reversal, the left and right banks are
With the exhaust pipes of the two adjacent to each other in one direction
Characterized by extending and merging at the merging portion on the downstream side
Exhaust device for V-type internal combustion engine. 5. A catalytic converter is provided immediately before a portion where the direction of the exhaust pipe of the one bank is reversed, and the exhaust pipes of the left and right banks are adjacent to each other beside the catalytic converter. The exhaust device for a V-type internal combustion engine according to claim 3 or 4 , wherein the exhaust device is configured to extend in one direction. 6. The catalytic converter provided in the exhaust pipe of the one bank is an elliptic catalytic converter,
The exhaust system for a V-type internal combustion engine according to claim 5 , wherein the exhaust system is provided with the longitudinal direction of the elliptical cross section being substantially vertical. 7. The exhaust pipes of the other bank among the exhaust pipes of the left and right banks that extend in one direction together in a state where they are substantially vertically adjacent to each other, the exhaust pipes of the other bank are more than the exhaust pipes of the one bank. The exhaust device for a V-type internal combustion engine according to claim 5 or 6 , wherein the exhaust device is provided close to the catalytic converter. 8. A catalytic converter is provided in a portion of the exhaust pipe of the other bank extending in the one direction, and upstream of a portion of the exhaust pipe of the one bank which is substantially vertically overlapped with the exhaust pipe. The exhaust device for a V-type internal combustion engine according to any one of claims 3 to 7 , wherein the exhaust device is mounted on the V-type internal combustion engine. 9. The catalytic converter provided in the exhaust pipe of the other bank is an elliptical catalytic converter.
The exhaust device for a V-type internal combustion engine according to claim 8 , wherein the exhaust device is provided with the longitudinal direction of the oval cross section being substantially horizontal. 10. An oil pan of the V-type internal combustion engine comprises a deep bottom portion and a shallow bottom portion in the output shaft direction, and exhaust pipes of the left and right banks are extended below the shallow bottom portion. exhaust system for a V-type internal combustion engine according to any one of claims 1-9 to. 11. The V-type internal combustion engine is mounted on a vehicle with its output shaft aligned in the left-right direction of the vehicle, and the left and right banks are opposed to each other in the front-back direction of the vehicle. side of the bank, the other bank to the vehicle front side of the bank, V type according to the one direction to any one of claims 1-10, characterized in that for combining the exhaust pipe of the left and right banks as vehicle rear Exhaust device for internal combustion engine.