| US 7,537,719 B2 | ||
| Method of manufacturing resin boot for constant-velocity universal joint | ||
| Kazuhiko Sueoka, Ageo (Japan); and Yasuji Takada, Ageo (Japan) | ||
| Assigned to Fukoku Co., Ltd., Saitama-ken (Japan) | ||
| Filed on Aug. 18, 2004, as Appl. No. 10/920,314. | ||
| Claims priority of application No. 2003-423942 (JP), filed on Dec. 22, 2003; and application No. 2004-131961 (JP), filed on Apr. 27, 2004. | ||
| Prior Publication US 2005/0134009 A1, Jun. 23, 2005 | ||
| Int. Cl. B29C 45/14 (2006.01) | ||
| U.S. Cl. 264—268 [264/269; 264/275; 264/274; 264/334] | 12 Claims |
| 1. A manufacturing method in which a boot main body primarily molded of a resin is held in an injection mold, a molten resin
material is injected/charged in a secondary molding space formed in the injection mold in this state, portions having different
thicknesses are secondarily molded on an other-end annular fastening portion of the boot main body to constitute a boot for
a constant-velocity universal joint, formed of the resin, and thereafter the boot for the constant-velocity universal joint,
formed of the resin, can be removed from the injection mold, the manufacturing method comprising the steps of:
holding the primarily molded resin boot main body from the outside by divided molds;
holding the boot main body from the inside by a core;
injecting/charging a molten resin material into a secondary molding space constituted of a thick portion molding space and
a thin portion molding space formed between the core and the other-end annular fastening portion, between the divided molds
and the other-end annular fastening portion, or between the core and the divided molds via the other-end annular fastening
portion by a runner mechanism; and
removing, from the core, the resin boot for the constant-velocity universal joint in which the molten resin material is charged
into the secondary molding space to integrally and secondarily mold portions having different thicknesses, constituted by
combining a thickness of the molten resin material in the secondary molding space with that of the boot main body, on the
other-end annular fastening portion by an ejection mechanism,
the runner mechanism being provided with injecting/charging gates for injecting/charging the molten resin materials onto optional
one or a plurality of positions of the secondary molding space,
the ejection mechanism being provided with a plurality of ejectors in positions avoiding the injecting/charging gates of the
runner mechanism, wherein predetermined ejecting forces are applied onto lower end surfaces of the portions having different
thicknesses in the other-end annular fastening portion of the resin boot for the constant-velocity universal joint from the
plurality of ejectors to remove the resin boot for the constant-velocity universal joint from the core.
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