| 摘要 |
<p>The present invention relates to forming a round hole, and a manufacturing method and a product manufactured by the method. To achieve this, the present invention forms the round hole with only a three stepped manufacturing process comprising: a first step of bending a material downward using a first state lower mold; a second step of drilling the downward bent portion using a first piercing punch and a die; and a third step of forming a round using a second state lower mold around the drilled material. As described above, the present invention prevents a belt from being cut from a shock by forming a round hall by only the three steps in manufacturing a coupling device for a safety belt of a vehicle, thereby dramatically improving the quality and reliability of a product for various needs for a consumer as a user is satisfied, and instilling a good image.</p> |
