Portable folding wagon

1. A portable folding wagon, comprising:

a wagon frame, the wagon frame comprising a folding frame and wheels,

the folding frame comprising four scissor mechanisms arranged in a rectangle,

a scissor mechanism of the four scissor mechanisms comprising at least a scissor unit, top portions of two adjacent scissor mechanisms being rotatably connected by a top connecting base, bottom portions of the two adjacent scissor mechanisms being rotatably connected by a bottom connecting base;

wherein

the bottom connecting base is rotatably connected to a support rod and has a through hole,

a top periphery of the through hole of the bottom connecting base extends upwardly to form a surrounding wall for the support rod to pass through,

a bottom end of the support rod passes through the surrounding wall and the through hole and connects to a wheel,

a top end of the support rod is rotatably connected to a sliding connecting piece, and

the sliding connecting piece is slidably connected to the scissor unit of the scissor mechanism.

2. The portable folding wagon according to claim 1 , wherein:

the scissor unit comprises two linkage rods, each having a central portion, the central portions being rotatably connected;

the four scissor mechanisms include two first scissor mechanisms arranged left and right and two second scissor mechanisms arranged front and back; and

a top portion of the linkage rod of the scissor unit of the first scissor mechanism corresponding to a corner of the rectangle is slidably connected to the sliding connecting piece.

3. The portable folding wagon according to claim 2 , wherein:

the top connecting base comprises two top rotating joints arranged in a right angle, the two top rotating joints being respectively rotatably connected to a top end of one linkage rod of the first scissor mechanism and a top end of one linkage rod of the second scissor mechanism;

the bottom connecting base comprises two first bottom rotating joints arranged in a right angle;

the two first bottom rotating joints are respectively rotatably connected to a bottom end of one linkage rod of the first scissor mechanism and a bottom end of one linkage rod of the second scissor mechanism.

4. The portable folding wagon according to claim 1 , wherein

the top end of the support rod is fixedly disposed with a fixing base,

the fixing base has a lug,

the lug is rotatably connected to the sliding connecting piece,

a top end of the lug is disposed on a top surface of the fixing base, and

a gap is formed between the top connecting base and the top surface of the fixing base when the folding frame is unfolded.

5. The portable folding wagon according to claim 2 , wherein

a first scissor mechanism of the two first scissor mechanisms comprises at least two scissor units arranged front and back, and

a second scissor mechanism of the two second scissor mechanisms comprises at least one scissor unit.

6. The portable folding wagon according to claim 5 , wherein:

lower portions of two adjacent scissor units of the first scissor mechanism are rotatably connected by a first central connecting base;

top portions of the two adjacent scissor units are rotatably connected by a second central connecting base;

the folding frame further comprises a bottom frame and the bottom frame comprises radial mechanisms arranged front and back with a same number as the scissor units of the first scissor mechanism,

a radial mechanism of the radial mechanisms comprises a central base and four bottom rods rotatably connected to the central base, and

an end of a bottom rod of the four bottom rods of the radial mechanism is rotatably connected to the first central connecting base or the bottom connecting base correspondingly.

7. The portable folding wagon according to claim 6 , wherein the first central connecting base is connected to the end of one bottom rod of two adjacent radial mechanisms at a same time.

8. The portable folding wagon according to claim 7 , wherein

the first central connecting base comprises two second bottom rotating joints and two central rotating joints,

the two second bottom rotating joints are respectively rotatably connected to a bottom portion of one linkage rod of the two adjacent scissor units, and

the two central rotating joints are respectively rotatably connected to the end of one bottom rod of two adjacent radial mechanisms.

9. The portable folding wagon according to claim 8 , wherein

the two second bottom rotating joints are arranged right and left, and

the two central rotating joints are fixedly disposed respectively at sides of the two second bottom rotating joints and formed to be splayed.

10. The portable folding wagon according to claim 6 , further comprising a case made of flexible material, the case being assembled to the folding frame and supported on the bottom frame, and the case and the central base of the radial mechanism are connected.

11. The portable folding wagon according to claim 2 , further comprising:

a pull rod mechanism;

wherein

the two linkage rods of the scissor unit of one of the two second scissor mechanisms are connected by a position base;

the position base has a first position groove;

the pull rod mechanism comprises a first pull rod, a second pull rod rotatably connected to the first pull rod, and a second position groove;

the first pull rod is rotatably connected to the position base; and

the first position groove and the second position groove are coupled in shape.

12. The portable folding wagon according to claim 11 , wherein:

the pull rod mechanism comprises two first pull rods and an assembly base;

the two first pull rods are arranged spaced apart;

one end of each of the two first pull rods is rotatably connected to the position base;

another end of each of the two first pull rods is fixedly connected to the assembly base;

the second pull rod is rotatably connected to the assembly base; and

the second position groove is disposed at the assembly base.