JP3812369B2 - Engine exhaust system for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a vehicle engine exhaust system in which a spherical joint for absorbing vibration is installed in the middle of an exhaust system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an automobile exhaust system, a flexible tube is installed in the middle of the exhaust system in order to reduce vibration transmitted from an engine or vibration transmitted from a road surface. This flexible tube has the advantage that it can absorb any relative displacement within the allowable deformation range of the tube itself, regardless of whether the vibration direction transmitted to the exhaust system is vertical, horizontal, or axial. However, it has to be installed so as not to interfere with adjacent members even with a large amount of deformation, resulting in a disadvantage that the installation space becomes large and the cost is high.
[0003]
Therefore, a spherical joint is employed instead of the flexible tube. As a vehicle engine exhaust system in which a spherical joint is installed in the exhaust system, for example, one disclosed in Japanese Patent Application Laid-Open No. 8-218863 is known.
[0004]
This publication aims to absorb both vertical vibration components and longitudinal vibration components transmitted from the engine to the exhaust pipe, suppress excessive stress generated in the exhaust pipe, and improve strength and durability. Of the exhaust pipe from the engine, the upstream side exhaust pipe and the downstream side exhaust pipe are hermetically connected to a portion extending substantially linearly in the vehicle longitudinal direction and a portion extending substantially linearly in the vehicle left-right direction, and An exhaust device is described in which a spherical joint that allows relative rotation of both exhaust pipes is inserted in a direction orthogonal to the extending direction of both connected exhaust pipes.
[0005]
[Problems to be solved by the invention]
However, in the conventional vehicle engine exhaust system, the vertical vibration of the exhaust pipe is absorbed by the first spherical joint 3A and the longitudinal vibration is absorbed by the second spherical joint 3B. There is a problem that spherical joints 3A and 3B are required.
[0006]
Further, as shown in FIG. 2 of the publication, the pressure connection mechanism 26 of the second spherical joint 3B is paired in the vehicle vertical direction, and the second spherical joint 3B moves relative to the vehicle vertical direction. The structure cannot absorb (relative movement is possible in the front-rear direction). For this reason, it is impossible to absorb the vertical vibration of the rear muffler (muffler 32) generated by idle vibration and the vertical vibration of the exhaust system accompanying road surface input.
[0007]
The present invention has been made paying attention to the above-mentioned problems, and its object is to absorb both engine roll vibration, exhaust system axial vibration, and exhaust system vertical vibration. Another object of the present invention is to provide a vehicle engine exhaust device that can easily cope with a case where a front exhaust system and a rear exhaust system are provided in the same vehicle.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an exhaust manifold is connected to an exhaust manifold disposed on the vehicle front side of a horizontally mounted engine mounted on the front of the vehicle, and extends below the exhaust manifold and the horizontally mounted engine. In the vehicle engine exhaust system, the exhaust pipe has an exhaust pipe directed toward the rear of the vehicle, a muffler provided in the middle of the exhaust pipe, and an insulator that supports the exhaust system member on the vehicle body. On the vehicle rear side of the engine, it has a kick-up portion that rises upward from the lower position of the engine, and an inclined portion whose tube axis line faces the roll center direction of the engine, and in the middle of the inclined portion, the first spherical joint is provided to allow the vehicle vertical displacement, the inclined portion is the position of the engine side of the first spherical joint, bullet to the vehicle body by the insulator And characterized in that it is supported.
[0009]
According to a second aspect of the present invention, in the vehicle engine exhaust apparatus according to the first aspect, the insulator includes a vehicle body side member and an exhaust pipe side member connected via an elastic body so as to be relatively displaceable in the vehicle vertical direction. It is characterized by.
[0010]
According to a third aspect of the present invention, in the vehicle engine exhaust device according to the first or second aspect, the position of the exhaust pipe whose tube axis is substantially directed in the vertical direction on the vehicle front side of the horizontally mounted engine. Further, a second spherical joint that allows displacement in the longitudinal direction of the vehicle is provided.
[0012]
Operation and effect of the invention
In the invention according to claim 1, the vehicle is connected to an exhaust manifold disposed on the vehicle front side of a horizontally mounted engine mounted on the front portion of the vehicle, and extends below the exhaust manifold and the horizontally mounted engine so as to be rear of the vehicle. A first spherical joint that allows displacement in the vertical direction of the vehicle is provided in the middle of the inclined portion of the exhaust pipe toward the rear side of the horizontally mounted engine, the pipe axis of which faces the roll center direction of the engine. ing.
[0013]
Therefore, for the rolling vibration of the engine, only the inclined portion on the upstream side of the first spherical joint of the inclined portion in response to the roll vibration as a fulcrum of the first spherical joint displaced in the vertical direction of the vehicle, the first spherical joint The up and down direction, which is the displacement allowable direction of the first spherical joint, and the engine roll direction substantially coincide with each other so that the inclined portion on the downstream side is kept in a substantially stationary state, so that engine roll vibration is absorbed in an orderly manner. be able to.
[0014]
Further, with respect to the axial vibration of the exhaust system, the upstream side and the downstream side of the first spherical joint in the inclined portion use the first spherical joint as a joint according to the vehicle vertical direction component of the axial vibration force. By displacing in the axial direction, it is possible to absorb the axial vibration of the exhaust system. That is, the position where the first spherical joint is provided is a position where the pipe axis is directed toward the roll center of the engine, in other words, a position having an inclination angle where the pipe axis rises upward from the horizontal. A part of the input becomes a vehicle vertical component due to the inclination angle.
[0015]
Further, with respect to the vertical vibration of the exhaust system, according to the vertical vibration input, the upstream side and the downstream side of the first spherical joint in the inclined portion are displaced in the vertical direction of the vehicle with the first spherical joint as a joint. Can absorb vertical vibrations.
[0017]
In the invention according to claim 1 , it is connected to an exhaust manifold disposed on the vehicle front side of a horizontal engine mounted on the front of the vehicle, and extends below the exhaust manifold and the horizontal engine. There is an exhaust pipe directed to the rear of the vehicle. The exhaust pipe is a kick-up section that rises from the lower position of the engine to the upper side on the vehicle rear side of the engine, and the pipe axis thereof faces the roll center direction of the engine. And an inclined portion .
[0018]
Therefore, a front exhaust system that is connected to an exhaust manifold disposed on the front side of a horizontally mounted engine mounted on the front of the vehicle and has an exhaust manifold and an exhaust pipe that extends below the horizontally mounted engine and extends toward the rear of the vehicle. The first spherical joint that absorbs both engine roll vibration, exhaust system axial vibration, and exhaust system vertical vibration can be applied to the vehicle.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment for realizing a vehicle engine exhaust apparatus according to the present invention will be described based on a first example corresponding to claims 1 to 3.
[0024]
(First embodiment)
First, the configuration will be described.
FIG. 1 is a side view showing a vehicle engine exhaust system according to the first embodiment. FIG. 2 is a plan view showing the vehicle engine exhaust system according to the first embodiment. In FIG. 3 is a manifold catalytic converter, 4 is a second spherical joint, 5 is a front tube, 6 is a heat shield, 7 is a first spherical joint, 8 is a first center tube, 9 is a center muffler, and 10 is a second center tube. , 11 is a pipe joint, 12 is a rear tube, 13 is a rear muffler, 14 is a tail tube, 15 is a first insulator, 16 is a second insulator, 17 is a third insulator, and 18 is a fourth insulator.
[0025]
A front exhaust system that is connected to an exhaust manifold 2 disposed on the front side of the horizontal engine 1 and extends below the exhaust manifold 2 and the horizontal engine 1 toward the rear of the vehicle; An exhaust system having a three-part structure of first and second center tubes 8 and 10 having a center muffler 9 and a rear tube 12 having a rear muffler 13 is employed.
[0026]
The horizontal engine 1 is mounted in a horizontal position with the crankshaft in the vehicle width direction at the front of the vehicle, and has a roll axis J connecting the vehicle body support points H and I, and a roll center K on the roll axis J. .
[0027]
The second spherical joint 4 is a joint that connects the downstream opening end of the manifold catalytic converter 3 and the upstream opening end of the front tube 5. It is arranged at the position of the upstream opening end of the front tube 5 facing the direction, and allows displacement in the vehicle longitudinal direction.
That is, as shown in FIG. 3, the flange 4a formed on the downstream opening end outer periphery of the manifold catalytic converter 3, the flange 4b fixed to the upstream opening end outer periphery of the front tube 5, and the flange 4a side A spherical seat 4c provided on the flange 4b, a spherical receiver 4d formed on the flange 4b, and bolts 4g and 4h for connecting the flanges 4a and 4b via springs 4e and 4f. , 4h are set as both end positions in the vehicle width direction (the vehicle left-right direction), thereby allowing a large displacement in the vehicle front-rear direction due to the relative displacement between the spherical seat 4c and the spherical receiver 4d.
[0028]
The front tube 5 includes a bent portion 5a, an engine downward extending portion 5b, a kick-up portion 5c, and an inclined portion 5d in order from the upstream side to the downstream side. It is covered by a heat shield plate 6 that blocks heat from the engine 1. The inclined portion 5d of the front tube 5 is elastically supported on the vehicle body by the first insulator 15 (FIG. 6).
[0029]
The first spherical joint 7 is a joint that connects the downstream opening end of the front tube 5 and the upstream opening end of the first center tube 8, and the tube axis of the first spherical joint 7 is placed horizontally on the vehicle rear side of the horizontally installed engine. The engine 1 is disposed at the positions of the front tube 5 facing the direction of the roll center K of the engine 1 and the inclined portions 5d, 8a of the first center tube 8, and allows displacement in the vehicle vertical direction.
That is, as shown in FIG. 4, the flange 7a fixed to the outer peripheral portion of the downstream opening end of the front tube 5, the flange 7b fixed to the outer peripheral portion of the upstream opening end of the center tube 8, and the flange 7a side. A spherical seat 7c provided, a spherical receiver 7d formed on the flange 7b, and bolts 7g and 7h for connecting both flanges 7a and 7b via springs 7e and 7f. By setting the mounting positions of 7h as both end positions in the vehicle width direction (vehicle left-right direction), a large displacement in the vehicle vertical direction is allowed by relative displacement between the spherical seat 7c and the spherical receiver 7d.
[0030]
The first center tube 8 includes an inclined portion 8a and a horizontal portion 8b in order from the upstream side toward the downstream side, and the second center tube 10 is sequentially formed from the upstream side toward the downstream side. It has a horizontal portion 10a and an inclined portion 10b, and is elastically supported by the vehicle body by a second insulator 16 (FIG. 7). A center muffler 9 is provided between the downstream opening end of the first center tube 8 and the upstream opening end of the second center tube 10.
[0031]
The rear tube 12 includes an inclined portion 12a and a horizontal portion 12b in order from the upstream side toward the downstream side, and includes a downstream opening end of the second center tube 10 and an upstream opening end of the rear tube 12. Are connected to each other. As shown in FIG. 5, the pipe joint 11 includes a flange 11 a fixed to the outer peripheral portion of the downstream opening end of the second center tube 10, and a flange 11 b fixed to the outer peripheral portion of the upstream opening end of the rear tube 12. The bolts and nuts 11c fasten and fix the flanges 11a and 11b.
[0032]
The rear muffler 13 is elastically supported on the vehicle body by a third insulator 17 (FIG. 8) and a fourth insulator 18 (FIG. 9).
[0033]
Next, the operation will be described.
[0034]
[Vibration absorption by spherical joint]
Of the exhaust pipes extending from the laterally mounted engine 1 mounted on the front of the vehicle toward the rear of the vehicle, the pipe axis extends in the direction of the roll center K of the engine 1 on the vehicle rear side of the laterally mounted engine 1. A first spherical joint 7 that allows displacement in the vehicle vertical direction is provided at the positions of the inclined front portions 5d and 8a of the front tube 5 and the first center tube 8 that face each other.
[0035]
Therefore, only the front tube 5 on the engine side of the exhaust pipe connected to the first spherical joint 7 responds to the roll vibration with the first spherical joint 7 as a fulcrum for the roll vibration of the horizontally mounted engine 1. The first spherical joint 7 is allowed to move in the displacement allowable direction so that the first and second center tubes 8, 10 and the like on the downstream side of the first spherical joint 7 are kept stationary. When the certain vertical direction and the engine roll direction substantially coincide with each other, the roll vibration of the horizontally placed engine 1 can be absorbed systematically.
[0036]
For the axial vibration of the exhaust system, the front tube 5 and the first center tube 8 connected to the first spherical joint 7 are connected to the first spherical joint 7 according to the vehicle vertical component of the axial vibration force. Displacement in the vertical direction of the vehicle with the joint as a joint makes it possible to absorb the axial vibration of the exhaust system. That is, as shown in FIG. 1, the position where the first spherical joint 7 is provided is a position where the pipe axis faces the direction of the roll center K of the horizontally placed engine 1, in other words, the pipe axis rises upward from the horizontal. Since the position has an inclination angle θ, a part of the axial vibration input becomes a vehicle vertical component due to the inclination angle θ.
[0037]
Further, with respect to the vertical vibration of the exhaust system, according to the vertical vibration input, the front tube 5 and the first center tube 8 connected to the first spherical joint 7 are displaced in the vehicle vertical direction with the first spherical joint 7 as a joint. By doing so, the vertical vibration of the exhaust system can be absorbed.
[0038]
On the other hand, among the exhaust pipes extending from the horizontally mounted engine 1 mounted on the front of the vehicle toward the rear of the vehicle, the front of which the axis of the tube is directed substantially in the vertical direction on the vehicle front side of the horizontally mounted engine 1. A second spherical joint 4 that allows displacement in the vehicle front-rear direction is provided at the position of the upstream opening end of the tube 5.
[0039]
Therefore, with respect to the longitudinal vibration of the exhaust system, the manifold catalytic converter 3 and the front tube 5 connected to the second spherical joint 4 are displaced in the vehicle longitudinal direction with the second spherical joint 4 as a joint in accordance with the longitudinal vibration input. Thus, the longitudinal vibration of the exhaust system can be absorbed.
[0040]
Next, the effect will be described.
[0041]
(1) On the vehicle rear side of the horizontally mounted engine 1, at the positions of the inclined portions 5d and 8a of the front tube 5 and the first center tube 8 whose tube axis faces the direction of the roll center K of the horizontally mounted engine 1. Since the first spherical joint 7 that allows displacement in the vertical direction of the vehicle is provided, it is possible to absorb both the roll vibration of the horizontally mounted engine 1, the axial vibration of the exhaust system, and the vertical vibration of the exhaust system.
In addition, it is possible to easily cope with a case where a front exhaust system as shown in FIG. 1 and a rear exhaust system as shown in FIG.
[0042]
(2) Since the exhaust manifold 2 disposed on the vehicle front side of the horizontally mounted engine 1 is connected and the exhaust manifold 2 extends below the horizontally mounted engine 1 and is directed to the rear of the vehicle, the front exhaust system is formed. The first spherical joint 7 that absorbs both the roll vibration of the horizontal engine 1, the axial vibration of the exhaust system, and the vertical vibration of the exhaust system can be applied to the vehicle.
[0043]
(3) On the vehicle front side of the horizontally mounted engine 1, a second spherical joint 4 that allows displacement in the vehicle front-rear direction is provided at the position of the upstream opening end of the front tube 5 whose tube axis is substantially directed in the vertical direction. Therefore, by adopting the first spherical joint 7 and the second spherical joint 4 in the vehicle of the front exhaust system, in addition to the roll vibration of the horizontal engine 1, the axial vibration of the exhaust system, the vertical vibration of the exhaust system, the exhaust It can absorb the longitudinal vibration of the system.
[0044]
(Other examples)
As mentioned above, although the vehicle engine exhaust apparatus of this invention has been demonstrated based on 1st Example, it is not restricted to 1st Example about a concrete structure, It concerns on each claim of a claim Design changes and additions are allowed without departing from the scope of the invention.
[0045]
For example, in the first embodiment, an example in which the first spherical joint 7 and the second spherical joint 4 are provided in the front exhaust system is shown. However, in the front exhaust system, as shown in FIG. On the vehicle rear side, a first spherical joint that allows displacement in the vehicle vertical direction at the inclined positions of the front tube 5 and the first center tube 8 whose tube axis faces the direction of the roll center K of the horizontally mounted engine 1. 7 may be provided (corresponding to the inventions according to claims 1 and 2). In FIG. 10, 19 is a pipe joint provided at the position of the second spherical joint 4 of the first embodiment, and 20 is an underfloor catalytic converter provided at an upstream position of the center muffler 9.
[Brief description of the drawings]
FIG. 1 is a side view showing a vehicle engine exhaust apparatus according to a first embodiment.
FIG. 2 is a plan view showing the vehicle engine exhaust device of the first embodiment.
FIG. 3 is a detailed view of a part A in FIG. 1 showing a second spherical joint of the vehicle engine exhaust device of the first embodiment.
FIG. 4 is a detailed view of part B of FIG. 1 showing a first spherical joint of the vehicle engine exhaust system of the first embodiment.
FIG. 5 is a detailed view of a portion C in FIG. 1 showing a pipe joint of the vehicle engine exhaust system of the first embodiment.
6 is a view in the direction of arrow D in FIG. 2 showing the first insulator of the vehicle engine exhaust system of the first embodiment.
7 is a view in the direction of arrow E in FIG. 2 showing a second insulator of the vehicle engine exhaust system of the first embodiment.
8 is a view in the direction of arrow F in FIG. 2 showing a third insulator of the vehicle engine exhaust system of the first embodiment.
FIG. 9 is a view in the direction of the arrow G in FIG. 2 showing a fourth insulator of the vehicle engine exhaust system of the first embodiment.
FIG. 10 is a side view showing another example of a vehicle engine exhaust device using a front exhaust system .
[ Explanation of symbols]
1 Horizontal engine 2 Exhaust manifold 3 Manifold catalytic converter 4 Second spherical joint 5 Front tube 6 Heat shield 7 First spherical joint 8 First center tube 9 Center muffler 10 Second center tube 11 Pipe joint 12 Rear tube 13 Rear muffler 14 Tail tube 15 1st insulator 16 2nd insulator 17 3rd insulator 18 4th insulator K Roll center of horizontal engine 1

Claims (3)

An exhaust manifold connected to an exhaust manifold disposed on the vehicle front side of a horizontally mounted engine mounted on a front portion of the vehicle, and extending under the exhaust manifold and the horizontally mounted engine toward the rear of the vehicle ;
A muffler provided in the middle of the exhaust pipe;
An insulator for supporting these exhaust system members on the vehicle body;
In a vehicle engine exhaust system having
The exhaust pipe has a kick-up portion that rises upward from the lower position of the engine on the vehicle rear side of the engine, and an inclined portion whose pipe axis faces the roll center direction of the engine ,
In the middle of the inclined portion, a first spherical joint that allows displacement in the vehicle vertical direction is provided,
The vehicle engine exhaust apparatus according to claim 1, wherein the inclined portion is elastically supported by the vehicle body by the insulator at a position closer to the engine than the first spherical joint . The vehicle engine exhaust device according to claim 1,
In the insulator, a vehicle engine exhaust device is characterized in that a vehicle body side member and an exhaust pipe side member are connected via an elastic body so as to be relatively displaceable in the vehicle vertical direction . The vehicle engine exhaust device according to claim 1 or 2,
A vehicular engine characterized in that a second spherical joint that allows displacement in the vehicle longitudinal direction is provided at the position of the exhaust pipe whose tube axis is substantially directed in the vertical direction on the vehicle front side of the horizontal engine. Exhaust system.

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