| 摘要 |
The invention relates to a self-drilling rock bolt comprising an intermediate expandable part (8) joined at its first end to a connector part (4) and at its second end to a drill bit unit (27), where said connector part (4) abuts against the first axial end surface (7) of said expandable part (8) thereby forming a first contact region (5), and where said drill bit unit (27) abuts against the second axial end surface (9) of said expandable part (8) thereby forming a second contact region (15), and where said expandable part (8), said first contact region (5), and said second contact region (15) all have cross-sections that at least partly overlap each other when seen axially along said rock bolt (2), thereby allowing axial forces during a hammer drilling operation to propagate in an essentially axial direction from said connector part (4) via said expandable part (8) into said drill bit unit (27) thus improving the axial stability of the rock bolt (2). |
