Self-locking mechanism for folding sofa

A self-locking mechanism for a folding sofa, comprising:

• a link assembly, comprising a first end pivoted to a front sofa cushion and a second end pivoted to a fixed base frame of a sofa frame, wherein the front sofa cushion is folded and stored on a rear sofa cushion inside the sofa frame or unfolded at a side of the rear sofa cushion through linkage of the link assembly;
• a self-locking rivet, located on the link assembly;
• and
• a limit rotating rod, movably provided on the front sofa cushion, wherein one end of the limit rotating rod is provided with an arc-shaped hook corresponding to the self-locking rivet;
• and when the front sofa cushion is unfolded at the side of the rear sofa cushion, the link assembly drives the self-locking rivet to slide into the arc-shaped hook through an opening of the arc-shaped hook, and the limit rotating rod cooperates with the self-locking rivet to prevent the link assembly from rotating;
• wherein the link assembly comprises:
• a first link, provided with a first link segment, wherein the first link segment comprises a first end pivoted to a lower side of the front sofa cushion and a second end pivoted to the fixed base frame;
• and
• a second link, provided with a second link segment and a third link segment located at a first end of the second link segment, wherein the second link segment corresponds to and is parallel to the first link segment;
• a second end of the second link segment is pivoted to the lower side of the front sofa cushion;
• a connecting end between the second link segment and the third link segment is pivoted to the fixed base frame;
• the third link segment is pivoted to a lower side of the rear sofa cushion;
• and when the front sofa cushion is folded and stored on the rear sofa cushion or unfolded at the side of the rear sofa cushion through the linkage of the link assembly, the third link segment drives the rear sofa cushion to fall or rise;
• wherein the lower side of the front sofa cushion is provided with a first connecting member;
• the first link segment and the second link segment are pivoted to the first connecting member;
• the lower side of the rear sofa cushion is provided with a second connecting member;
• and the third link segment is pivoted to the second connecting member;
• wherein the limit rotating rod is provided with a first end, a second end opposite to the first end, and a middle segment located between the first end and the second end;
• the arc-shaped hook is located at the first end;
• the middle segment is pivoted to the first connecting member;
• and the limit rotating rod is configured to rotate around a pivot position of the limit rotating rod to slide the self-locking rivet out of the arc-shaped hook.