Method for molding pinion
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsHiroshi Nomura, Norio Sato
Life of this patent
Estimating the term…
Abstract
A molded pinion includes separate gear portions with gear teeth, and gearless shaft portions provided between the adjacent gear portions. The shaft portions have an outer diameter smaller than the dedendum of the gear teeth of the gear portions. Each shaft portion has an axial length longer than an axial length of each gear portion. Disclosures are also directed to a molding die assembly including first split dies which are movable in radial directions to form the gear portions of the pinion, and second split dies which are movable in radial directions independently of the first split dies to form the shaft portions, and a molding method using the molding die assembly.
Claims14
A method for producing a molded pinion having at least two separate gear portions with gear teeth, at least one gearless shaft portion provided between the gear portions and molded integrally therewith, and a center axial hole extending through the gear portions and the at least one gearless shaft portion, wherein the at least one gearless shaft portion has an outer diameter smaller than a dedendum of the gear teeth and wherein the at least one gearless shaft portion has an axial length longer than an axial length of each gear portion, said method comprising:
- introducing a molding material in a molding cavity of predetermined shape defined in a die assembly including movable first split dies for molding the gear portions, movable second split dies for molding the gearless shaft portions, a stationary end plate and a movable end plate which the first and second movable split dies are supported between the stationary and movable end plates a shaft rod extending through a center of the molding cavity between the first and second movable split dies for forming the center axial hole, the shaft rod further extending through and secured to the stationary end plate, the first and second split dies being movable in a radial direction of the shaft rod, and a pusher extending through the stationary end plate and movably attached to an outer periphery of the shaft rod to be slidable thereon;
- moving the second split dies away from the shaft rod to expose the gearless shaft portions upon formation of the molded pinion;
- sliding the pusher along the shaft rod to move the molded pinion in an axial direction by a predetermined displacement to expose the gear portions;
- and,
- moving the first split dies away from the shaft rod.
A method for molding a pinion having at least two separate gear portions with gear teeth and at least one gearless shaft portion provided between the gear portions, comprising:
- providing a die assembly including movable first split dies for molding the gear portions, movable second split dies for molding the gearless shaft portions, a stationary end plate and a movable end plate which the first and second movable split dies are supported between the stationary and movable end plates, a shaft rod extending through a center of the molding cavity between the first and second movable split dies and fixed in an axial direction with respect to the first and second split dies, the shaft rod extending through and secured to the stationary end plate, and a pusher extending through the stationary end plate and movably attached to an outer periphery of the shaft rod to be slidable thereon, wherein the die assembly defines a molding cavity of predetermined shape;
- introducing a molding material into the molding cavity and allowing the molding material to set;
- moving the second split dies away from the shaft rod to expose the gearless shaft portions;
- sliding the pusher along the shaft rod to move the molded pinion in said axial direction away from the shaft rod by a predetermined displacement to expose the gear portions;
- and,
- moving the first split dies away from the shaft rod.
A method for producing a molded pinion having at least two separate gear portions with gear teeth and at least one gearless shaft portion provided between the gear portions, comprising:
- providing a die assembly including movable first split dies for molding the gear portions, movable second split dies for molding the gearless shaft portions, a stationary end plate, a movable end plate, and a core fixedly supported on the stationary end plate, wherein the core extends through a center of a molding cavity defined by the first and second split dies, the stationary end plate and the movable end plate, and the core is further provided with a pusher slidably attached to an outer periphery of the core;
- introducing a molding material into the molding cavity and allowing the molding material to set;
- moving the second split dies away from the core to expose the gearless shaft portions upon formation of the molded pinion;
- sliding the pusher along the core to move the molded pinion in an axial direction by a predetermined displacement to expose the gear portions;
- and,
- moving the first split dies away from the core.
Dependencies are inferred from the claim text.