Hollow element for attachment to a component comprising a composite material
View Patent ↗A hollow element such as a hollow rivet or a nut element for attachment to a component consisting of a composite material such as a fiber reinforced plastic part or a fabric reinforced plastic part is presented. The element has a flange part and a shaft part extending away from the flange part and/or a rivet section, wherein the rivet section, is present, can also be formed at the free end of the shaft part, with the a hollow element furthermore having a central passage, which is optionally provided with a thread cylinder. The hollow element is used in combination with an auxiliary tip which is either inserted from the flange side of the element through the passage, or from the side of the free end of the shaft part of the rivet section into the passage, such that a conically converging region of the auxiliary tip projects from the free end of the shaft part or of the rivet section.
1. A hollow nut element ( 100 ) for attachment to a component ( 130 ) comprising a composite material such as a fiber reinforced plastic part or a fabric reinforced plastic part, wherein the element has a flange part ( 102 ) and a and a rivet section ( 106 ) having an outer diameter and a free end and extending away from the flange part ( 102 ), wherein the hollow element furthermore has a central passage ( 108 ) and a thread cylinder provided in the hollow passage, wherein the hollow nut element ( 100 ) is used in combination with an auxiliary tip ( 126 ) which is inserted from the free end of the rivet section ( 106 ) into the passage such that a conically converging region ( 128 ) of the auxiliary tip ( 126 ) projects from the free end of the rivet section, the auxiliary tip ( 126 ) having, behind the conically converging tip ( 128 ), a maximum diameter which corresponds to or is somewhat smaller than the outer diameter of the rivet section ( 106 ) and merges via a rounded neck ( 129 ) into a portion ( 133 ) of smaller diameter which is received in the thread cylinder ( 112 ) or in the central passage ( 108 ).
2. The hollow nut element in accordance with claim 1 , wherein features ( 118 , 120 ) providing security against rotation are provided in the region of the flange part ( 102 ) in order to form a security against rotation between the hollow element ( 100 ) and the component ( 130 ).
3. The hollow element in accordance with claim 1 , wherein the flange part ( 102 ) is provided with an annular planar contact surface ( 114 ) which is provided with discrete axial projections ( 120 ) which can be pressed into the matrix material of the component.
4. The hollow element in accordance with claim 1 , wherein the flange part ( 102 ) is provided with an annular planar contact surface ( 114 ) and has, radially inside this contact surface, an axial ring groove ( 116 ) and wherein features providing security against rotation, such as ribs providing security against rotation ( 118 ) and/or recesses providing security against rotation, are provided at the base region of the axial ring groove.
5. The hollow element in accordance with claim 1 , wherein a shaft portion is provided between the flange part and the rivet section.
6. The hollow element in accordance with claim 5 , wherein the axial ring groove ( 116 ) is arranged concentric to the shaft part ( 104 ).
7. The hollow element in accordance with claim 1 , wherein the auxiliary tip ( 126 ) is held by a press fit which does not damage the thread ( 112 ) or by a weak adhesive bond or by a magnetic force in the passage.
8. The hollow element in accordance with claim 1 , wherein the auxiliary tip ( 126 ) has a cylindrical region ( 133 ) which can be introduced into the passage ( 108 ) of the hollow element and has the rounded ring shoulder between the conically converging tip ( 128 ) and the cylindrical region, with the ring shoulder being capable or being brought into contact against the free end of the rivet section ( 106 ) prior to the piercing of the component ( 130 ).
9. The hollow element in accordance with claim 1 , wherein the free end of the rivet section ( 106 ), has a conically converging form ( 180 ) which is matched to the conical shape of the auxiliary tip ( 126 ) that is used.
10. An auxiliary tip ( 126 ) configured for use in combination with a hollow element ( 100 ) in accordance with claim 1 .