| 摘要 |
<p>PURPOSE:To improve the buckling resisting property and the dimension accuracy of a molded body, while enabling the molded product to be injection molded by a method in which the material with high hardness and high Young's modulus is used for the joint boot-molded product of an automobile, and the port diameter- ratio of bellows is caused to be in the range of 1.08-1.40. CONSTITUTION:For the constitution of bellows, the thermoplastic polyester elastomer material with large tensile yield strength kg/cm<2> (strength at yield point) and large tensile yield elongation % (elongation at yield point) is used in the point of material property. The cone shape bellows connecting the interval between the part of a large diameter port and the part of a small diameter port by said bellows, is injection molded such that the ratio of the outer diameter of the crest adjacent to a trough at large diameter port side to the outer diameter of said trough is in the range of 1.08-1.40. The molded body has excellent property, while causing no irregular deformation such as buckling at the deformed angle used practically.</p> |
