Connection structure and assembly method of tube-shaped frames

An assembly method of tube-shaped frames, in which the tube-shaped frames comprise a pair of roof side frames which are provided at both sides of a vehicle body and a roof cross member which extends perpendicularly to the roof side frames so as to connect to the roof side frames at both ends thereof, the assembly method comprising:

• a step of providing brackets for connecting the both ends of the roof cross member to the roof side frames, the brackets comprising an upper split-bracket and a lower split-bracket, each of the upper split-bracket and the lower split-bracket having a flange which extends along a split line of the upper and lower split-brackets;
• a first step of joining the lower split-bracket to a lower portion of the roof side frame by one-side continuous welding;
• a second step of joining the upper split-bracket to an upper portion of the end of the roof cross member by one-side continuous welding;
• a third step of assembling the upper split-bracket joined to the roof cross member to the lower split-bracket joined to the roof side frame;
• a fourth step of joining the flanges of the upper and lower split-brackets which are overlapped by temporary welding;
• and
• a fifth step of joining said flanges joined by the temporary welding by one-side continuous welding.

An assembly method of tube-shaped frames, in which the tube-shaped frames comprise a pair of roof side frames which are provided at both sides of a vehicle body and a roof cross member which extends perpendicularly to the roof side frames so as to connect to the roof side frames at both ends thereof, the assembly method comprising:

• a step of providing brackets for connecting the both ends of the roof cross member to the roof side frames, the brackets comprising a pair of split-brackets which is arranged in a specified direction, each of the split-brackets having a flange which extends along a split line of the split-brackets;
• a first step of joining one of the split-brackets to a portion of the roof side frame by one-side continuous welding;
• a second step of joining the other of the split-brackets to another portion of the end of the roof cross member by one-side continuous welding;
• a third step of assembling the other of the split-brackets joined to the roof cross member to the one of the split-brackets joined to the roof side frame;
• a fourth step of joining the flanges of the split-brackets which are overlapped by temporary welding;
• and
• a fifth step of joining said flanges joined by the temporary welding by one-side continuous welding.