Vertical-bar connection assembly for collapsible wagon, and collapsible wagon

A vertical-bar connection assembly for a collapsible wagon, the vertical-bar connection assembly having an extended state and a folded state and being adapted to be hinged between adjacent vertical bars of the collapsible wagon, wherein the vertical-bar connection assembly comprises at least one vertical-bar connection member comprising a first connecting bar and a second connecting bar, wherein each of the first connecting bar and the second connecting bar has a proximal end and a distal end, wherein the proximal ends of the first connecting bar and the second connecting bar are hinged with each other, and wherein the distal ends of the first connecting bar and the second connecting bar are respectively adapted to be hinged with the adjacent vertical bars of the collapsible wagon, and are rotatable about their respective proximal ends to move away from or close to each other, so as to allow the vertical-bar connection assembly to be in the extended state or in the folded state,

• wherein the vertical-bar connection assembly comprises at least two vertical-bar connection members spaced apart, wherein during the extension and folding of the at least two vertical-bar connection members, the first connecting bars are always parallel to each other, and the second connecting bars are always parallel to each other.