Method for manufacturing differential device and differential device
AssigneeSubaru Corporation
InventorYusuke Shirakawa
Life of this patent
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Abstract
A method for manufacturing a differential device includes a first step and a second step. The first step is to cast a differential case by pouring molten cast iron into, via a gate, a mold having, on a mold surface, a mark formation site that has a specific positional relationship to the gate. The second step is to fit the differential case with a ring gear and weld the differential case and the ring gear together entirely around a prescribed axis. In the second step, the differential case and the ring gear are welded together using a mark formed on the differential case by the mark formation site in the first step so that an overlap of welding does not occur in a portion of the differential case formed near the gate of the mold.
Claims6
A method for manufacturing a differential device, comprising:
- a first step of casting a differential case by pouring molten cast iron into, via a gate, a mold having, on a mold surface, a mark formation site that has a specific positional relationship to the gate;
- and
- a second step of fitting the differential case with a ring gear and welding the differential case and the ring gear together entirely around a prescribed axis,
- wherein, in the second step, the differential case and the ring gear are welded together using a mark formed on the differential case within the mark formation site in the first step so that an overlap of welding does not occur in an area where a pearlite ratio is higher in the differential case.
A differential device, comprising:
- a differential case made of a casting containing cast iron as a main component;
- and
- a ring gear that has an opening with which a cylinder of the differential case is fitted and is welded with the differential case entirely around a prescribed axis,
- wherein, in the differential case, a pearlite ratio is higher in a partial area in a round direction of the cylinder than in another area, and the differential case has a mark having a specific positional relationship to the partial area where the pearlite ratio is higher, and
- an overlap where a base point and an end point of a welding overlap is located in an area different from the area where the pearlite ratio is higher.
Dependencies are inferred from the claim text.