Exhaust pipe structure

Abstract

A center of gravity (G1) of a second exhaust pipe (12) is located on the side of an axis (J1) connecting two associated support members (16, 17) that is distal to a ball joint (15). Thus, creating a moment that applies a load (F1) to a ball joint (15 that presses the ball joint (15) up toward the vehicle body. In turn, by locating a center of gravity (G2) of a third exhaust pipe (13) on the side of an axis (J2) connecting two associated support members (19, 20) that is proximal to the ball joint (15) the weight of the third exhaust pipe (13) creates a moment which that applies a load (F2) to the ball joint (15) that presses the ball joint (15) down away from the vehicle body. Consequently, the load (F1) and the load (F2) of approximately the same magnitude act in opposite directions.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a structure of an exhaust pipe connected to an internal combustion engine.[0003]2. Description of the Related Art[0004]Generally, vibrations generated by the internal combustion engine in operation are transmitted to the exhaust pipe connected to the internal combustion engine. A load caused by these vibrations is thus imposed on the exhaust pipe, which disadvantageously lowers durability and reliability of the exhaust pipe. In addition, the vibrations are transmitted through a support member for the exhaust pipe to a vehicle body, causing undesirable noise and vibrations in the vehicle interior. Therefore, in order to suppress transmission of exhaust pipe vibrations or absorb the vibrations, a widely used exhaust pipe structure has: an exhaust pipe including plural separate exhaust pipes connecting in series to join an exhaust manifold of the internal combustion engine; and a universal ...

AI Technical Summary

Benefits of technology

[0008]According to the first aspect, the loads from the weight of the separate exhaust pipes that act on the universal joint, combine to be almost zero. Therefore, the universal joint is prevented from being displaced from its normal position in the static sate, thereby supporting the exhaust pipe at the normal mounting position. This prevents the exhaust pipe from being excessively displaced beyond the allowable range despite vibrations when the vehicle travels off-road or over an uneven road. Consequently, the exhaust pipe is precluded from interfering with peripheral components.

[0018]The third exhaust pipe is supported by the other support member at the part furthest from the phantom line, which connects the one support member and the second universal joint, the one support member supporting the part of the third exhaust pipe further from the second universal joint. This minimizes turning motion of the third exhaust pipe about the phantom line, although the third exhaust pipe tends to vibrate intensively due to its location at a free end on the downstream side of exhaust gas flow. This reduces vibrations of the exhaust pipe when the vehicle travels off-road or over an uneven road surface, while suppressing undesirable noise and vibrations in the vehicle interior.

Problems solved by technology

A load caused by these vibrations is thus imposed on the exhaust pipe, which disadvantageously lowers durability and reliability of the exhaust pipe.

In addition, the vibrations are transmitted through a support member for the exhaust pipe to a vehicle body, causing undesirable noise and vibrations in the vehicle interior.

This can cause the exhaust pipe to be displaced from its normal position in the static state.

When the vehicle travels off-road or over an uneven road surface, the exhaust pipe, supported at the position out of the normal mounting position, can be excessively displaced beyond the allowance range.

Thus, the exhaust pipe tends to interfere with peripheral components.

Nonetheless, supporting the exhaust pipe in this preferred manner is sometimes difficult mainly due to insufficient body strength at the position adjacent to the universal joint.

This could result in difficulty in supporting the exhaust pipe at its normal position in the static state.

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