Method for knitting three-dimensional fabric with variable thickness through a flat knitting machine

A method for knitting a three-dimensional fabric with variable thickness through a flat knitting machine, comprising the following steps:

• step (1):
• moving two cam groups onto two needle beds which are disposed relatively, and driving a plurality of knitting needles to knit a first piece of knitting by a starting cam system included in one of the two cam groups;
• step (2):
• moving the two cam groups, and driving the plurality of knitting needles to knit a second piece of knitting by a middle cam system included in the other one of the two cam groups;
• step (3):
• moving the two cam groups, and driving the plurality of knitting needles to knit a supporting yarn by two tail cam systems respectively included in the two cam groups, wherein two ends of the supporting yarn are respectively interwoven with the first piece of knitting and the second piece of knitting, and a required knitting length of the supporting yarn is determined by a thickness of the three-dimensional fabric, moving each of a plurality of knock-over bit cams controlled by each of the tail cam systems in a knitting process to shift positions of two sets of knock-over bits respectively provided on the two needle beds, and changing a gap size defined by a distance between the two sets of knock-over bits of the two needle beds according to the required knitting length of the supporting yarn in the knitting process, so as to promptly change the knitting length of the supporting yarn and the thickness of the three-dimensional fabric;
• and
• step (4):
• repeating the step (1) to the step (3) to complete the three-dimensional fabric.