JP2005329758A - Exhaust system structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust system structure capable of improving the shock absorption of an exhaust system at the time of a vehicle collision and improving safety performance more than ever.
SOLUTION: In an exhaust system 10, catalytic converters 3, 4, a center pipe 5, a muffler 6, a tail pipe 8, and a gas exhaust port 9 are connected to a front pipe 2 connected to an exhaust manifold provided in an engine 1. It is a thing. The center pipe 5 and the tail pipe 8 have two curved portions 51 and 52 and curved portions 81 and 82, respectively, and straight pipe portions 53 and 83 located between them are formed on the side wall on the same side of the muffler 6. The muffler 6 is connected so as to penetrate in an oblique direction.
[Selection] Figure 1

Description

  The present invention relates to an exhaust system structure.

  Generally, in an automobile, an exhaust system is configured by connecting components such as a front pipe, a catalytic converter, a center pipe, a muffler, and a tail pipe to an engine (internal combustion engine). As a structure of an exhaust system, what was described in patent documents 1-3 is mentioned, for example.

The lower body structure of an automobile described in Patent Document 1 is intended to optimize the weight distribution and to protect the fuel tank, and between the two side members arranged in the longitudinal direction of the vehicle, the muffler And an exhaust system structure in which a silencer is connected via an exhaust pipe. The vehicle body structure described in Patent Document 2 aims to increase the capacity of a fuel tank, and an exhaust system structure in which a catalyst, a member recognized as a pre-muffler, and a silencer are connected via an exhaust pipe. It has. Further, the automobile muffler structure described in Patent Document 3 is intended to reinforce the joint between the muffler and the exhaust pipe and to suppress the deformation of the fuel tank, and the bent exhaust pipe is a protective member. Is connected to the muffler.
Japanese Utility Model Publication 4-116622 JP-A-11-78551 JP 2003-3838 A

  By the way, when an excessive load is applied to a vehicle of an automobile due to a collision or the like, and deformation of the vehicle and its internal devices and parts occurs, it is possible to minimize the human and physical effects on and outside the vehicle interior as much as possible. desired. Actual vehicle collision forms vary widely depending on the specific situation, but basically, front and / or rear collisions (front / rear collision; normal) along the traveling direction of the vehicle In addition, full lap collisions and offset collisions are assumed depending on the location of the collision.) And collisions on the side of the vehicle (side collisions) are important. Even in safety evaluation, impact resistance and impact absorption during such collisions are important. The importance is attached to the property, the suppression of device deformation, and the like.

  In order to improve such safety performance, the vehicle body rigidity of the automobile is enhanced, the side member provided in the vehicle body structure of Patent Document 1 above, and in addition, the cross member installed so as to cross between the side members In general, it is generally performed to ensure load absorption or load resistance at the time of collision.

  However, the members constituting the exhaust system are generally arranged so as to extend along the front-rear direction (longitudinal direction) of the vehicle, as exemplified in Patent Documents 1 to 3 above. Since the rigidity of the direction tends to be relatively high, if the shock absorption at that time is insufficient, especially during the front and rear collisions of the vehicle, the exhaust system members can easily interfere with peripheral devices and parts, or the vehicle interior There is a possibility that inconveniences such as easy to protrude outward may occur. For example, in the structures described in Patent Documents 1 to 3, the exhaust pipe is connected to the front and rear end portions of the muffler and the pre-muffler along the substantially axial direction, and the axial rigidity at the connection portion is the lateral rigidity. It tends to be larger than

  Accordingly, the present invention has been made in view of such circumstances, and an object of the present invention is to provide an exhaust system structure that can improve the shock absorption of the exhaust system at the time of a vehicle collision and can improve safety performance more than ever. And

  In order to solve the above problems, an exhaust system structure according to the present invention includes a muffler, and an inlet pipe and an outlet pipe connected to the side surface of the muffler. The “side surface side” indicates the side surface side when the traveling direction of the vehicle or the like on which the muffler is mounted is defined as the front-rear direction, and the position in the vertical direction is not limited.

  In the exhaust system structure configured in this way, the inlet pipe (inlet side exhaust pipe) and the outlet pipe (outlet side exhaust pipe) are connected from the side surface side of the muffler. The respective extending directions of the outlet pipes are unlikely to be the same as the extending direction of the entire exhaust system, that is, the axial direction (a large load tends to be applied along this direction at the time of front / rear collision). Therefore, the axial rigidity at the connection portion between the muffler and each pipe and the axial rigidity of the entire exhaust system structure can be reduced.

  In this case, it is preferable that the inlet pipe and the outlet pipe are connected to the same side surface side of the muffler. In this way, the extension direction of the inlet pipe and the outlet pipe can be easily arranged so that they do not coincide with each other, so that the axial rigidity at the connecting portion between the muffler and each pipe and the axial rigidity of the entire exhaust system structure are further reduced. obtain.

Alternatively, the exhaust system structure according to the present invention includes a muffler and the following formula (1):
θ ≠ 0 ° (1),
An inlet pipe and an outlet pipe provided so as to satisfy the relationship represented by In the equation, θ represents an angle formed by the extending direction at the connecting portion between the inlet pipe and the muffler and the extending direction at the connecting portion between the outlet pipe and the muffler. That is, in the connection part with a muffler, it is good for both to be connected to the muffler so that the extension direction of an inlet pipe and an outlet pipe may not become the same or parallel.

  More specifically, it is preferable that at least one of the inlet pipe and the outlet pipe has a plurality of curved portions.

  By doing so, when an impact load is applied, stress concentrates on the bent portion of the inlet pipe and / or the outlet pipe, the shock absorption increases, and there are a plurality of bent portions. Or it becomes easy to form an outlet pipe in a desired shape.

  According to the exhaust system structure of the present invention, each of the inlet pipe and the outlet pipe is connected to the side surface side of the muffler, or the extending direction of the inlet pipe and the outlet pipe does not coincide or become parallel at the connection site. Thus, the axial rigidity of the entire exhaust system structure is weakened, and the shock absorption at the time of a vehicle collision can be improved.

  Hereinafter, embodiments of the present invention will be described in detail. The positional relationship such as up, down, left, and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

  FIG. 1 is a plan view showing a preferred embodiment of an exhaust system structure according to the present invention. The exhaust system 10 (exhaust system structure) is connected to an exhaust manifold (not shown) provided in the engine 1 provided in the vehicle. In the exhaust system 10, catalytic converters 3 and 4, a center pipe 5 (inlet pipe), a muffler 6, a tail pipe 8 (outlet pipe), and a gas discharge port 9 are connected to a front pipe 2 connected to an exhaust manifold. As a whole, the vehicle is disposed so as to extend in the front-rear direction of the vehicle (traveling direction; directions indicated by the arrows F and B, respectively).

  The center pipe 5 has two curved portions 51, 52, and is connected to the muffler 6 so that a straight pipe portion 53 (connecting portion) positioned between them is inserted into the side wall of the muffler 6 in an oblique direction. Has been. The tail pipe 8 has curved portions 81 and 82, and a straight pipe portion 83 (connecting portion) provided with a flange 7 located between them is connected to the center pipe 5 in the muffler 6. It is connected to the muffler 6 so as to penetrate into the same side wall in an oblique direction.

By connecting the center pipe 5 and the tail pipe 8 to the muffler 6 in this way, the following formula (1);
θ ≠ 0 ° (1),
The relationship represented by is satisfied. Here, θ represents an angle formed between the extending direction of the straight pipe portion 53 of the center pipe 5 (indicated with a dashed-dotted line Da in the drawing) and the extending direction of the straight pipe portion 83 of the tail pipe 8 (indicated with a dashed-dotted line Db in the illustrated). That is, the center pipe 5 and the tail pipe 8 are connected to the muffler 6 so that they are not parallel to each other in plan view.

  In the exhaust system 10 configured in this way, the center pipe 5 and the tail pipe 8 are connected obliquely from the side surface side of the muffler 6 to the side wall thereof. 53, 83 extending directions Da, Db do not coincide with the longitudinal direction of the vehicle (arrows F, B), that is, straight pipe portions 53, 83 are different from the extending direction (axial direction) of exhaust system 10 as a whole. Oriented.

  Therefore, since the axial rigidity of the exhaust part 10 as a result of the connection between the muffler 6 and the center pipe 5 and the tail pipe 8 is lowered, the shock absorption around the muffler 6 is improved. In particular, among the members constituting the exhaust system 10, the muffler 6 is a relatively heavy member that greatly contributes to the overall weight. Therefore, the safety performance is greatly improved by increasing the shock absorption around the muffler 6. It becomes possible to make it.

  Therefore, even if a large impact load is applied along the extending direction of the entire exhaust system 10 due to the front / rear collision of the vehicle, the interference between each component of the exhaust system 10 and its peripheral devices and parts, and the cause thereof Therefore, the center pipe 5 and the tail pipe 8 can be prevented from projecting into and out of the passenger compartment. As a result, it is possible to minimize the human and physical effects on the interior and exterior of the vehicle interior when the vehicle collides.

  Further, since the center pipe 5 and the tail pipe 8 are connected from the same side surface side of the muffler 6, the extending directions Da and Db of the respective straight pipe portions 53 and 83 do not coincide with each other, and as shown in the drawing, the extending direction Da , Db form a certain angle θ, the rigidity along the axial direction of each of the pipes 5 and 8 can also be reduced. As a result, the absorbability of the impact load at the time of collision can be further improved, and the safety performance can be further improved.

  Furthermore, since both the center pipe 5 and the tail pipe 8 have a plurality of curved portions 51, 52, 81, 82, the stress due to the applied load tends to concentrate on those portions, and both the pipes 5, 8 and thus the exhaust system The rigidity of the entire 10 can be further reduced, and the shock absorption in the exhaust system 10 can be further increased. Further, since the bending portion 51 and the bending portion 52, and the bending portion 81 and the bending portion 82 are different in bending direction, the arrangement space is inconvenient while suppressing the pressure loss in the center pipe 5 and the tail pipe 8. Can be prevented.

  In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation is possible in the limit which does not change the summary. For example, at least one of the center pipe 5 and the tail pipe 8 may be arranged on the side surface opposite to the drawing. Further, it is not always necessary to provide the curved portions 51, 52, 81, and 82 in the center pipe 5 and the tail pipe 8, and when they are provided, one may be provided, or three or more may be provided.

  Furthermore, when the exhaust system 10 has a plurality of mufflers (for example, a main muffler and a sub muffler), it is useful to employ the configuration of the present invention for at least one of the mufflers, particularly a muffler having a large weight. Furthermore, the exhaust system 10 is not limited to the one connected to the inline engine, and may of course be an exhaust system connected to the V-type engine, for example.

  The exhaust system structure according to the present invention can improve the shock absorption of the exhaust system at the time of a vehicle collision and can improve the safety performance more than ever, so that the equipment such as a vehicle provided with the exhaust system connected to the internal combustion engine. It can be widely used for motives, equipment, etc.

1 is a plan view showing a preferred embodiment of an exhaust system structure according to the present invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Front pipe, 3, 4 ... Catalytic converter, 5 ... Center pipe (inlet pipe), 6 ... Muffler, 7 ... Flange, 8 ... Tail pipe (outlet pipe), 9 ... Gas exhaust port, 10 ... Exhaust system (Exhaust system structure), 51, 52, 81, 82 ... curved portion, 53, 83 ... straight pipe portion, Da, Db ... extending direction.

Claims (4)

With a muffler,
An inlet pipe and an outlet pipe connected to a side surface of the muffler;
Exhaust system structure with The inlet pipe and the outlet pipe are connected to the same side of the muffler.
The exhaust system structure according to claim 1. With a muffler,
Following formula (1);
θ ≠ 0 ° (1),
An inlet pipe and an outlet pipe provided so as to satisfy the relationship represented by (wherein, θ is the extending direction of the connecting portion between the inlet pipe and the muffler, and the connecting portion between the outlet pipe and the muffler) The angle formed by the extending direction in
Exhaust system structure with At least one of the inlet pipe and the outlet pipe has a plurality of curved portions.
The exhaust system structure according to any one of claims 1 to 3.

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