Vehicle Exhaust Muffler Tail Pipe Elongation via Vertical Offset
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Solution Overview
Problem
In vehicle exhaust structures, the muffler's shape must conform to the rear cowl, limiting the tail pipe's length and reducing exhaust gas flow velocity, which affects engine output characteristics.
Innovation Solution
The exhaust structure features a muffler with vertically offset penetrating positions for the tail pipe and connecting pipes, allowing the tail pipe to be elongated while reducing the muffler and rear cowl's width, and incorporating a tubular cover to enhance capacity and rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the muffler is arranged inside the rear cowl and its shape is formed to correspond with the rear cowl, then the exhaust system fits within the vehicle rear portion, but the tail pipe length is limited and exhaust gas flow velocity is reduced
Solution Approach 1:
The patent applies dimensional reconfiguration by vertically offsetting the penetrating positions of the tail pipe and connecting pipes through the partition. This vertical separation in the third dimension allows the tail pipe to extend longer without interfering with the connecting pipes, thereby increasing exhaust gas flow velocity while maintaining compact lateral dimensions that fit within the rear cowl.
2Speed
If the tail pipe is elongated to increase exhaust gas flow velocity, then engine output characteristic is improved, but the muffler width must be increased which conflicts with the rear cowl shape
Solution Approach 1:
The invention resolves this contradiction by utilizing vertical offsetting of pipe penetrating positions through the partition. This allows the tail pipe to achieve greater length (improving exhaust gas flow velocity) without increasing the lateral width of the muffler, as the extended tail pipe occupies a different vertical zone rather than expanding the horizontal footprint.
3Shape
If the muffler and rear cowl are formed with decreasing width toward the vehicle rear, then aerodynamic performance and compactness are improved, but the tail pipe and connecting pipes interfere with each other
Solution Approach 1:
The patent maintains the tapered outline of the muffler and rear cowl by implementing vertical offsetting of the penetrating positions. This dimensional separation allows multiple pipes (tail pipe and connecting pipes) to pass through the partition at different vertical levels, eliminating interference between them while preserving the aerodynamic tapered shape toward the vehicle rear.
4Productivity
If the tail pipe is made longer to improve exhaust flow, then engine performance is enhanced, but the exhaust system size and air resistance increase
Solution Approach 1:
The invention achieves longer tail pipe length for improved engine performance by utilizing vertical offsetting through the partition. This approach allows the tail pipe to extend longer in the longitudinal direction without proportionally increasing the overall exhaust system volume or weight, as the extended portion is accommodated within the existing vertical space rather than requiring additional lateral or vertical expansion.
Data Source
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AI summary
An exhaust structure for a vehicle including a rear cowl (35) covering a vehicle rear portion has a muffler (29) including a first expansion chamber (C1) and a second expansion chamber (C2) partitioned by a partition (65), first and second connecting pipes (67, 68) connecting the expansion chambers, and a tail pipe (69) configured to discharge exhaust gas from the muffler (29). The muffler (29) is covered by the rear cowl (35) such that outlines of the muffler (29) and the rear cowl (35) are each formed such that the width decreases toward the vehicle rear. The tail pipe (69) and the first and second connecting pipes (67, 68) are provided so as to penetrate the partition (65); and the position where the tail pipe (69) penetrates the partition (65) and the positions where the first and second connecting pipes (67, 68) penetrate the partition (65) are vertically offset. This allows the tail pipe to be elongated.