| 摘要 |
<p>When extruding profiles having fins with thin cross-section or narrow spacing, e g heat sinks, it has not been possible, without using special tool supports, to achieve a ratio between the fin height and the spacing between two adjacent fins of more than 5:1 due to loss of strength of the extrusion tool. The disclosed invention solves this problem by the use of an extrusion die comprising an aperture having a bearing portion (10) and a tapered portion (14) and where the bearing portion of the aperture is directly transferred into the tapered portion by a change of the taper angle of the aperture walls from α to β. The extreme pressures on the thin sections and sharp corners of the extrusion tool is thereby avoided and no breakdown of the extrusion tool occurs. A heat sink profile with portions of thin cross-section or narrow spacing that is produced to its final shape may thereby be produced.</p> |
