A molding method of a projection-welding spinning tensioner, the molding method comprising the following steps:
- step 1:
- blanking, including mounting a blanking die on a punching machine, and punching a steel plate to obtain a prefabricated workblank in a circular thin plate shape;
- step 2:
- piercing, including mounting a piercing die on the punching machine, and punching a center inner hole at a center of the prefabricated workblank;
- step 3:
- side-reversing, including mounting a side-reversing die on a hydraulic machine, initially molding an outer edge part of the prefabricated workblank, initially molding the outer edge part into an arc side-reversing structure, and performing side-reversing on a center site into a 90° straight-side structure, which is an axial vertical structure, and obtaining a first level semi-finished product;
- step 4:
- pressing a projection-welding point, including pressing a corresponding projection-welding point on the first plate end and/or the second plate end through a projection welding machine, and protruding the projection-welding point downward with a surface concaved, and obtaining a second level semi-finished product;
- step 5:
- two-piece welding, including selecting two pieces of the second level semi-finished products, arranging the second level semi-finished products in a mirror-symmetrical manner, making down-protruding positions of the projection-welding point correspondingly opposite to each other, and completing projection-welding, and obtaining a third level semi-finished product;
- step 6:
- spinning for molding, including mounting a premolding spinning wheel and a molding spinning wheel respectively on corresponding spinning wheel stations on a spinning machine, driving the third level semi-finished product to rotate through rotation of a main shaft of the spinning machine, so as to enable a working surface of the premolding spinning wheel to contact and squeeze a rim end of the third level semi-finished product from an exterior to an interior, and to exit after a squeezing process reaches a threshold, and forming a first rim end or a second rim end and obtaining a first level spinning blank;
- and enabling a working surface of the molding spinning wheel to contact and squeeze a rim end of the first level spinning blank from an exterior to an interior and to exit after a squeezing process reaches the threshold, forming a first rim edge or a second rim edge corresponding to a slope structure, and obtaining a spinning semi-finished product;
- step 7:
- punching a small hole, including mounting a small hole punching die on the punching machine, and punching the spinning semi-finished product to obtain a fourth level semi-finished product with a small hole of a prescribed diameter;
- step 8:
- secondary side-reversing, including mounting a secondary side-reversing die on a small hydraulic machine, and performing side-reversing on one of an upper end and a lower end of a center site of the fourth level semi-finished product into a 90° straight-side structure, with a secondary side-reversing surface being a radial expansion structure;
- step 9:
- pressing a bearing, including corresponding the bearing through the small hydraulic machine to an opening end of the center site which is not radially secondary side-reversed, so as to press the bearing into a cavity groove, and obtaining a fifth level semi-finished product;
- step 10:
- third side-reversing, including mounting a third side-reversing die on the small hydraulic machine, performing side-reversing on another one of the upper end and the lower end, which is not secondary side-reversed in step 8, of a center site of the fifth level semi-finished product into a 90° straight-side structure, with a third side-reversing surface being a radial expansion structure, and packaging the bearing in the step 9 into the cavity groove to obtain a sixth level semi-finished product;
- and
- step 11:
- painting, including performing black electrophoretic painting processing on a surface of the sixth level semi-finished product to obtain a finished product.