| 摘要 |
<p>An exhaust member having two or more exhaust ports separated by a partition wall extending between an inner wall of a tubular portion, wherein said partition wall has the minimum thickness A in a range within 1/2 of the length of said partition wall from its longitudinal middle point as a center, when viewed in an arbitrary transverse cross section of said tubular portion (including an opening end surface) having said partition wall; wherein said partition wall becomes gradually wider outside said range; and wherein each outer surface of said partition wall exists in a region sandwiched by (a) an inner line comprising a parallel line H1, H2 separate from the longitudinal centerline of said partition wall by a distance of A/2, and an arc R1, R2 tangentially connected to said parallel line H1, H2 and said inner wall and having a radius r1, r2, wherein both r1 and r2 are 1/3 x A or more, meeting r1 + r2 = 1.9A, and (b) outer line comprising a parallel line H3, H4 separate from the longitudinal centerline of said partition wall by a distance of 3/2 x A, and an arc R3, R4 tangentially connected to said parallel line H3, H4 and said inner wall and having a radius r3, r4, wherein both r3 and r4 are 1/3 x A or more, meeting r3 + r4 = 4A.</p> |
