The invention for the method using the roll forming device for manufacturing a pleated smooth tube, By more specifically form a double smooth tube by the width difference between the roll forming unit while improving the external pressure strength against the internal sewage using a roll forming apparatus which can improve the flowability to a method for manufacturing a pleated smooth tube.
Method using the roll forming apparatus of the present invention for producing a pleated inner smooth tube is bent portion 1 has a diameter of R1, having a width of W1, with respect to the bent portion 1 left and right side has a diameter in the RA to rotate the upper roller 1 forming the shape of a circle with the has a diameter of R1, has the required ipbu 1 which can be bent part 1 is inserted having a width of W1, of the urine left in ipbu 1, the right side has RB diameter with a circular shape for forming the lower roller 1 to rotate while the steel sheet to the upper roller 1 and the lower roller 1 between the passage to step (S10), and the bent portion 2 is R2 with a diameter of the take, W2 of the width a has the with respect to bend two left and right side surface it has to rotate the upper roller 2 forms a circular shape with a diameter of RA, has a diameter of said R2 is a bend 2 having a width of W2 with the concave inlet 2 which can be inserted , the yaw of ipbu two left and right side surface has a step (S20) of the steel plate upper side while rotating the lower roller 2 forms a circular shape with a diameter of RB rollers 2 and passes between the lower roller 2, bend 3 R3 have a diameter of, the bent part has a width of W3, the left and right side surface of the bent part 3 to rotate the upper roller 3 forms a circular shape with a diameter of RA, has a diameter of said R3 having a width of W3 3 has a concave inlet 3 which can be inserted, the concave inlet 3 of the left and right side of the passing between the plate while rotating the lower roller 3 forms a circular shape with a diameter of RB upper roller 3 and lower roller 3 and the step (S30) for, with R4 diameter of the bent portion 4, of a width of W4, bent portions 4 left and right side surface has to rotate the upper roller 4 forms a circular shape with a diameter of RA, the R4 have a diameter with a concave inlet 4 that can be bent portion 4 is inserted with a width of W4, the concave inlet 4 of the left and right side view of the rotating the lower roller 4 forms a circular shape with a diameter of RB the steel strip the upper rollers 4 and the steps (S40) to pass between the lower rollers 4, has a diameter of the bent part 5 is R5, having a width of W5, of the bent part 5, left and right side of the circle with a diameter of RA of to rotate the upper roller 5 forming a shape, the have R5 diameter with a concave inlet 5 which can be bent part 5 is inserted with a width of W5, the concave inlet 5 of the left and right side of the circle with a diameter of RB while the rotation of the lower rollers 5 forming a shape with R6 diameter of the step (S50), and the bent part 6 for passing the upper roller 5 and between the lower rollers 5, the steel sheet has a width of W6, of the bent part 6 left and right side view, and includes the concave inlet 6 which rotates the upper roller 6 forms a circular shape with a diameter of RA, it can be said to have a diameter of R6 to be bent part 6 is inserted with a width of W6, the concave inlet 6 the left and right side view of the rotating the lower roller 6, forming a circular shape with a diameter of RB step (S60) of the steel sheet to the upper roller 5 and passes between the lower roller 5; roll forming unit comprising the to provide a method for producing a smooth tube using corrugated.