Self-piercing riveting
A method for forming a joint using a self-piercing rivet includes the steps of: positioning the sheet material over a die and providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head. The ratio of the difference between the outside and inside diameters of the shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52. The method also includes positioning a rivet over the sheet material at a position opposite the die and using a punch to set the rivet and force it into the sheet material such that it pierces the upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.
1. A method for forming a joint in at least one high strength sheet steel having a UTS (Ultimate Tensile Strength) in the range 200 to 1400 MPa using a self-piercing rivet comprising the steps of: positioning the sheet steel over a die; providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head, the ratio of the difference between the outside and inside diameters of the shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52; positioning a rivet over the sheet steel at a position opposite the die; using a punch to set the rivet and force the rivet into the sheet steel such that the rivet pierces an upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.
2. A method according to claim 1 , used to join a plurality of sheets of such material, the rivet penetrating the uppermost sheet and deforming so as to join all of the sheets together, but not penetrating the lowermost sheet at least.
3. A method according to claim 1 , wherein the total thickness of the sheets being joined is in the region 2.5 to 7 mm.
4. A method according to claim 1 , wherein the total thickness of the sheets being joined is in the region 2.5 to 8 mm.
5. A method according to claim 1 , wherein the, or each, sheet of material has a thickness of no greater than 4 mm.
6. A method according to claim 1 , wherein the, or each, sheet of material has a thickness of no greater than 6 mm.
7. A method according to claim 1 , wherein the rivet material is aluminium or aluminium alloy.
8. A method according to claim 1 , wherein the shank of the rivet has an outside diameter of 5.5 mm and the cross sectional area of the shank in the region around the bore is greater than 16.5 mm 2 .
9. A method according to claim 1 , wherein the ratio of the diameter of the head to the outside diameter of the shank is in the range 1.35 to 2.4.
10. A method according to claim 1 , wherein the ratio of the effective length of the rivet to the depth of the bore is in the range 1.56 to 2.4:1.
11. A method for forming a joint between at least one high strength sheet steel having a UTS (Ultimate Tensile Strength) in the range 200 to 1400 MPa and a sheet of different material using a self-piercing rivet comprising the steps of: positioning the sheet material over a die; providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head, the ratio of the of the difference between the outside and inside diameters shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52; positioning a rivet over the sheet material at a position opposite the die; using a punch to set the rivet and force the rivet into the sheet material such that the rivet pierces an upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.
12. A method according to claim 11 , wherein the total thickness of the stack of material being joined is in the range 4 mm to 18 mm.
13. A method according to claim 11 , wherein the sheet of high strength steel has a thickness in the range 1 to 4 mm.
14. A method according to claim 11 , wherein the sheet of high strength steel has a thickness in the range 1 to 6 mm.
15. A method for forming a joint in a plurality of sheets of material, the combined thickness of the sheets being in the range 4 mm to 18 mm using a self-piercing rivet comprising the steps of: positioning the plurality of sheets of material over a die; providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head, the ratio of the difference between the outside and the inside diameters of the shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52; positioning a rivet over the plurality of sheets of material at a position opposite the die; using a punch to set the rivet and force the rivet into the plurality of sheets of material such that the rivet pierces an upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.
16. A method for manufacturing a product by forming a joint in at least one high strength sheet steel having a UTS (Ultimate Tensile Strength) in the range 200 to 1400 MPa using a self-piercing rivet comprising the steps of: positioning the sheet steel over a die; providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head, the ratio of the difference between the outside and inside diameters of the shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52; positioning a rivet over the sheet steel at a position opposite the die; using a punch to set the rivet and force the rivet into the sheet material such that the rivet pierces an upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.
17. A method for manufacturing a product by forming a joint between at least one high strength sheet steel having a UTS (Ultimate Tensile Strength) in the range 200 to 1400 MPa and a sheet of different material using a self-piercing rivet comprising the steps of: positioning each of the sheets over a die; providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head, the ratio of the difference between the outside and inside diameters of the shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52; positioning a rivet over the sheet material at a position opposite the die; using a punch to set the rivet and force the rivet into the sheet material such that the rivet pierces an upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.
18. A method for manufacturing a product by forming a joint in a plurality of sheets of material, the combined thickness of the sheets being in the range 4 mm to 18 mm using a self-piercing rivet comprising the steps of: positioning the plurality of sheets of material over a die; providing a rivet having a substantially cylindrical shank and a head, the shank having a central blind bore and an annular piercing end spaced from said head, the ratio of the difference between the outside and inside diameters of the shank in the region around the bore to the outside diameter of the shank is in the range 0.47 to 0.52; positioning a rivet over the sheet material at a position opposite the die; using a punch to set the rivet and force the rivet into the sheet material such that the rivet pierces an upper surface thereof and such that the shank deforms outwardly to interlock with the material but without penetration to the die side of the material.