Cold forging method and apparatus
AssigneeSekiguchi Sangyo Co., Ltd.
InventorYoshio Sekiguchi
Life of this patent
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Abstract
A stock inserted into a die is sandwiched between a punch and a knock-out, a predetermined pressing force is applied to the knock-out, and a pressing force larger than the sum of the pressing force of the knock-out and a pressing force for forming is applied to the punch to effect a forming work, whereby the forming accuracy can be enhanced and a final product can be obtained by going through only a slight finishing work.
Claims7
A cold forging method for forming a helical pinion gear having a cylindrical portion and a gear portion, comprising the steps of:
- preparing a die having a forming section comprising a cylindrical forming portion and a tooth pattern portion;
- inserting a stock into the cylindrical forming portion;
- sandwiching the stock inserted into the die between a punch and a knock-out, the punch being rotatable with respect to the die and inserted from the cylindrical forming portion, the knock-out being engaged into the tooth pattern portion;
- and
- applying to the punch a pressing force so as to move the stock toward the tooth pattern portion without gap in the forming section while the pressing force applied to the punch rotates the punch, stock and knock-out.
A cold forging apparatus for forming a helical pinion gear having a cylindrical portion and a gear portion, comprising:
- a die having a forming section having a cylindrical forming portion and a tooth pattern portion, the forming portion being configured to receive a stock;
- a punch configured to be rotatably fitted into the cylindrical forming portion;
- a knock-out configured to be screwed into the tooth pattern portion;
- and
- wherein when a pressing force is applied to the punch, the stock is moved toward the tooth pattern portion without gap in the forming section while the pressing force applied to the punch rotates the punch, stock and knock-out, thereby forming the stock into the helical pinion gear.
Dependencies are inferred from the claim text.