Tail Trim Assembly of Exhaust Pipe for Vehicle and Method of Manufacturing the Same

Abstract

The present invention relates to a tail trim assembly of an exhaust pipe for a vehicle of which shape is simplified to reduce the number of portions and process is changed to simplify processes so that manufacturing cost is reduced and productivity and quality are improved, and a method of manufacturing the tail trim. According to the present invention, a tail trim of an exhaust pipe for a vehicle includes a first tail trim portion of which one end is attached to an exhaust pipe at the rear portion of a vehicle, and a second tail trim portion that has an inner diameter increased in a streamlined shape toward the outside and is integrally formed with the other end of the first tail trim portion.

1 . A tail trim of an exhaust pipe for a vehicle, comprising:
 a first tail trim portion, one end of which is attached to a rear end of an exhaust pipe; and   a second tail trim portion integrally formed with an opposite end of the first tail trim portion from the exhaust;   wherein the second tail trim portion has an inner diameter substantially increasing in a streamlined shape toward an outside of the exhaust.   
   
   
       2 . The tail trim as defined in  claim 1 , wherein a maximum inner diameter of the second tail trim portion is larger than a maximum inner diameter of the first tail trim portion. 
   
   
       3 . The tail trim as defined in  claim 1 , further comprising:
 a carbonized film formed along an inner surface of the first and second tail trim portions.   
   
   
       4 . A method of manufacturing a tail trim of an exhaust pipe for a vehicle, the method comprising:
 forming a substantially tubular pipe section by a pipe forming process;   forming a first tail trim assembly along the pipe section by a hydroforming process for injecting fluid into the pipe section at high pressure, the first tail assembly including first and second tail trim portions;   performing a heat treatment process in the first tail trim assembly;   forming a second tail trim assembly by a hydroforming process for injecting fluid into the tail trim assembly at high pressure; and   performing at least one of cutting, deburring, and restriking to the second tail trim assembly.   
   
   
       5 . The method as defined in  claim 4 , wherein in the second tail trim forming, the second tail trim is formed so that an inner diameter of the second tail trim part substantially increases in a streamlined shape toward an outside of the exhaust. 
   
   
       6 . The method as defined in  claim 4 , wherein the performing of the heat treatment process includes forming a carbonized film along an inner surface of the first and second tail trim portions of the first tail trim assembly. 
   
   
       7 . The method as defined in  claim 4 , further comprising:
 repeating a heat treatment process in the second tail trim assembly; and   hydroforming by injecting fluid into one of the first tail trim assembly, second tail trim assembly, and pipe section at high pressure one or more times.   
   
   
       8 . The tail trim assembly as defined in  claim 1 , wherein the first and second tail trim portions are monolithically formed. 
   
   
       9 . The tail trim assembly as defined in  claim 1 , wherein the exhaust pipe, the first tail trim portion, and the second tail part are substantially coaxial. 
   
   
       10 . An exhaust system for a vehicle comprising a tail trim as defined in  claim 1 . 
   
   
       11 . A passenger vehicle comprising the exhaust as defined in  claim 10 . 
   
   
       12 . The method as defined in  claim 4 , wherein in the hydroforming of the first and second trail trim portions, the first and second tail trim portions are formed so that inner diameters of the first and second tail trim portions substantially increase in a streamlined shape toward the pipe section. 
   
   
       13 . The method as defined in  claim 4 , further comprising:
 repeating a second heat treatment process and a third hydroforming process for injecting fluid into the secondarily formed pipe at high pressure after the second hydroforming process.   
   
   
       14 . A tail trim assembly of an exhaust pipe for a vehicle, comprising:
 a first tail trim portion, one end of which is attached to a rear end of the exhaust pipe; and   a second tail trim portion formed at an opposite end of the first tail trim portion and extending outwards in a longitudinal direction;   wherein inner diameters of the first and second trail trim portions substantially continuously increase in the longitudinal direction.   
   
   
       15 . The tail trim assembly as defined in  claim 14 , wherein an inner diameter of the first tail trim portion adjacent the exhaust pipe is smaller than an inner diameter of the second tail trim portion at the opposite end. 
   
   
       16 . The tail trim assembly as defined in  claim 15 , wherein the inner diameter of the first tail trim portion formed at the other end thereof is larger than an inner diameter of the exhaust pipe. 
   
   
       17 . The tail trim assembly as defined in  claim 15 , wherein the first tail trim portion extends from the rear end of the exhaust pipe such that an outer surface of the first tail trim portion has a substantially concave shape. 
   
   
       18 . The tail trim assembly as defined in  claim 7 , wherein the second tail trim portion extends from the opposite end of the first tail trim portion such that an outer surface of the second tail trim portion has a substantially convex shape. 
   
   
       19 . The tail trim assembly as defined in  claim 14 , further comprising a carbonized film formed along an inner surface of the first and second tail trim portions.