Sofa backrest connection structure and sofa assembly

A sofa backrest connection structure, characterized by comprising a first member (11) and a second member (12), wherein the first member (11) comprises a first base plate (111), two guide rails (112) symmetrically arranged on the first base plate (111), and a limiting part (113) which is arranged on the first base plate (111) and located on the two guide rails (112), and the limiting part (113) is provided with a clamping protrusion (1132);

• the second member (12) comprises a second base plate (121) and a first horizontal plate (122) connected to the second base plate (121), the second base plate (121) comprises an insertion part (1211), and the insertion part (1211) is provided with a clamping hole (12111) matched with the clamping protrusion (1132);
• after the insertion part (1211) is slidably inserted into and fitted with the two guide rails (112), the clamping protrusion (1132) is clamped in the clamping hole (12111);
• and
• the first horizontal plate (122) is used for being connected with a sofa seat frame (2), and the first base plate (111) is used for being connected with a sofa backrest (3);
• wherein the second base plate (121) and the first horizontal plate (122) are integrally bent and formed.