| 摘要 |
PROBLEM TO BE SOLVED: To improve the manufacturing yield of a needle of injection by providing a bending machine capable of making collapse in a bent part as small as possible. SOLUTION: In a tube bending device in which a disk-like fixed space block 1 forming a circumferential groove of approximately semi-circular cross section on its outer circumference and a disk-like rotatable space block 2 forming a circumferential groove of approximately semi-circular cross section on its outer circumference which is turned around the fixed piece are provided, a cylindrical tube is loaded to the circumferential groove of the fixed space block 1 and the tube is bent by turning the rotatable space block 2 around the fixed space block 1, the cross section of the circumferential groove 3 of the fixed space block 1 is made to a semi-circular which is slightly deeper than that of a perfect semi-circle, and the cross section of the circumferential groove of the rotatable space block 2 is made to a semi-circular slightly shallower than that of the perfect semi-circle corresponding thereto. In this case, the degree that the tube loaded to the circumferential groove is restricted by the circumferential groove is larger than the conventional case and the distortion is hardly generated. Thus, the degree of being collapsed in a bent part is reduced. |
