Support frame for chair

The present invention relates to a support frame for a chair, comprising: a base plate (110); a support plate (120, 130) rotatably connected to the base plate (110); and a first hinge (150) that rotatably connects the base plate (110) and the support plate (120, 130), in which the base plate (110) is supported by the seat (11) of the chair (10) and the support plate (120, 130) is supported by the backrest (12) of the chair (10) to support the upper body of the seated person in a state where the base plate (110) and the support plate (120, 130) are unfolded at a first maximum unfolding angle ([theta] 1m), thereby providing excellent seating feeling and comfort. 本发明涉及一种椅子用支撑架，其特征在于，构成为包括：基板(110)；支撑板(120、130)，其可旋转地连接到基板(110)；以及第一铰链(150)，其可旋转地将基板(110)与支撑板(120、130)连接，其中，在基板(110)和支撑板(120、130)以第一最大展开角(θ1m)展开的状态下，基板(110)被椅子(10)的座部(11)支撑，支撑板(120、130)被椅子(10)的靠背(12)支撑而支撑就坐者的上身，从而具有提供极佳的就坐感和舒适性的优点。