Foldable trolley frame for foldable trolley and foldable trolley thereof

A foldable trolley frame for a foldable trolley, comprising:

• a side frame having a sliding support rod and an upright rod;
• a lower frame having a first sliding component and a lower rod, the first sliding component being slidably connected to the upright rod, one end of the lower rod being hingedly connected to the sliding support rod, the other end of the lower rod being hingedly connected to the first sliding component;
• an upper frame having an upper rod and an upper folding assembly, one end of the upper rod being hingedly connected to the sliding support rod, the other end of the upper rod being hingedly connected to the upright rod, one end of the upper folding assembly being hingedly connected to the upper rod, the other end of the upper folding assembly being hingedly connected to the lower rod;
• wherein the first sliding component is slidable between an unfolded position and a folded position;
• wherein when the first sliding component slides from the unfolded position toward the folded position under an external force, the lower rod rotates relative to the upright rod, the upper folding assembly rotates relative to the lower rod, the upper rod rotates relative to the upright rod, and the sliding support rod moves in a direction approaching the upright rod.