To manufacture a bollard in which an inner core material can be easily inserted into an outer elastic material and also the outer elastic material can be firmly secured to the inner core material, and in which an inner peripheral surface of the outer elastic material is not peeled from the outer peripheral surface of the inner core material even when temperature of a place where the bollard has been constructed is largely changed.
An inner core material 20 and an outer elastic material 30 are formed in such a way that an outer diameter At of the inner core material is larger than an inner diameter bt of the outer elastic material at any temperature between -30°C to 50°C. After that, the outer elastic material 30 is heated until the inner diameter bt of the outer elastic material 30 becomes larger than the outer diameter At of the inner core material 20 and consequently the outer elastic material 30 is expanded. Then, the inner core material 20 is inserted into the expanded outer elastic material 30. By cooling the outer elastic material 30 to shrink, the outer elastic material 30 is secured to the inner core material 20.
SUEFUJI YUICHI
| JPH0976365A | 1997-03-25 | |||
| JPH07299823A | 1995-11-14 | |||
| JPH10168842A | 1998-06-23 | |||
| JP2008223233A | 2008-09-25 |
Hirosaburo Mori
Mizue Ikeoka
Atsushi Kimura