HOLLOW-CORE-BODY FOR TRANSMISSION CABLE, MANUFACTURING METHOD THEREOF, AND SIGNAL TRANSMISSION CABLE

摘要

Provided is a hollow-core-body for transmission cables, a manufacturing method thereof, and a signal transmission cable, wherein the degree of electrical hollowness is high, mechanical strength (especially side-pressure strength) is excellent, and production of the cable can be conducted with stability. An insulation sheathing body (2) is composed of an inner-circular section (2a), multiple rib sections (2b) extending radially from this inner-circular section (2a), and an outer-circular section (2c) that connects the outer ends of the rib sections (2b), and is also provided with three or more gap sections (2d) surrounded by the inner-circular section (2a), the outer-circular section (2c), and each of the rib sections (2b). The hollow core body (10, 11), which has the insulation sheathing body (2) installed around the circumference of an inner conductor (1, 3), has the thickness of the inner-circular section (2a) made to be in a range of 1-4% of the outer circumference of the insulation sheathing body, and also made to be thinner than the rib sections (2b) and the outer-circular section (2c).