Fastening means comprising a blind rivet element and a sealing element

Description

[0001] The present invention relates to a fastening means comprising a blind rivet element and a sealing element.

[0002] Blind rivet elements have proven their worth for fastening tasks requiring a screw connection in thin-walled materials, such as sheet metal, into which threads cannot normally be cut. A blind rivet element is known, for example, from EP 1 918 596 A1.

[0003] Furthermore, DE 10 2012 015 144 A1 discloses a fastening means comprising a blind rivet element and a sealing element, wherein the blind rivet element is designed as a blind rivet nut with a head portion and a shank adjacent to the head portion in an axial direction. A sealing element is applied to the blind rivet nut to prevent moisture from penetrating the receiving opening of a component made of carbon fiber-reinforced plastic into which the blind rivet nut is inserted. The sealing element can protect the receiving opening from moisture ingress, for example, from splashing water.

[0004] DE 10 2012 000 547 A1 discloses a blind rivet comprising a rivet body with a shank, the shank being surrounded by a sleeve made of an electrically non-conductive plastic. The blind rivet disclosed in DE 10 2012 000 547 A1 has the features of the preamble of patent claim 1. DE 10342316 A1 describes a known fastening means.

[0005] The object of the present invention is to further develop a fastening means having a blind rivet element in such a way that a fluid flow and / or heat flow from a first side of a component into which the fastening means is introduced to a second side of the component opposite the first side and vice versa is avoided in the region of the fastening means.

[0006] This object is achieved by a fastening means having the features of patent claim 1.

[0007] The fastening means comprises a blind rivet element and a sealing element, wherein the blind rivet element has a head section and a shank adjacent to the head section in an axial direction Z. The shank has an internal thread and a deformation section between the internal thread and the head section. The deformation section serves to form a closing head when the deformation section is deformed. The sealing element has a closed jacket section and a closed cover section adjacent to the jacket section in the axial direction, wherein the jacket section circumferentially encloses the shank of the blind rivet element at least in the region of the deformation section and the cover section is formed on an end of the shank of the blind rivet element facing away from the head section.

[0008] The blind rivet element is designed as a blind rivet nut, insofar as it is designed as a blind rivet element with an internal thread in the region of the shank. Connecting a fastener that has a blind rivet element in the form of a blind rivet nut, insofar as it has a blind rivet element with an internal thread, to a component can be achieved by first placing the fastener in a prefabricated hole or in a prefabricated receiving opening in the component and then riveting it with a suitable tool, which typically has a rotatable and axially displaceable threaded mandrel.To do this, the threaded mandrel is screwed into the internal thread of the blind rivet nut from the head section side and, when the tool is in contact with the head section, is then moved axially so that the deformation section is compressed and a counter flange, i.e. a closing head, is formed between the start of the thread and the underside of the component. The closing head, together with the head section of the blind rivet nut, which is arranged on the upper side of the component, anchors the blind rivet nut and thus the fastener in the component. The threaded mandrel is then unscrewed. The blind rivet nut then serves as a holder for a fastening screw. If the blind rivet element is designed as a blind rivet threaded bolt, the shank has a holder for a threaded bolt, which is usually welded or pressed into the holder.Connecting the fastener with a blind rivet threaded bolt is done in the same way as connecting the fastener with a blind rivet nut, with the difference that the threaded bolt is pulled directly.

[0009] Since the sealing element has a closed jacket section and a closed cover section, wherein the jacket section circumferentially encloses the shaft of the blind rivet element at least in the region of the deformation section and the cover section is formed at an end of the shaft of the blind rivet element facing away from the head section, during the formation of the closing head the jacket section of the sealing element is deformed according to the deformation of the deformation section of the shaft and encloses the closing head of the blind rivet element after the blind rivet element has been set.Typically, the sealing element's jacket section, which is deformed in the area of ​​the closing head and preferably closed, rests against the component on the side of the component facing away from the head section of the blind rivet element and thus surrounds the receiving opening, preventing fluid flow—a flow of gas or liquid—from one side of the component to the other side of the component through the receiving opening and vice versa. Additional effects / advantages include protection against particles such as dust or dirt entrained in the fluid, and the fact that the sealing element / head section converts a blind rivet element with an open end into one with a closed end.The blind rivet element is therefore a cheaper and easier to produce part, while avoiding the well-known poor surface coating of closed-end blind rivet elements, especially blind rivet nuts, where it is not possible to reach the lowest area of ​​the blind rivet element / blind rivet nut during coating.

[0010] In addition, the blind rivet element, which is typically made of a metal or metal alloy, is not exposed, or at least only to a lesser extent, to the atmosphere or environmental conditions prevailing on the side of the component associated with the locking head. For example, it is conceivable that an atmosphere prevails on the side of the component associated with the locking head that would be corrosive to the material of the blind rivet element or would promote corrosion of the material of the blind rivet element, e.g., an atmosphere with high humidity or an atmosphere containing metal-oxidizing substances, e.g., an acid. Due to this corrosion protection, a blind rivet element / blind rivet nut made of low-carbon steel (with or without a surface coating) can be used instead of a blind rivet element / blind rivet nut made of stainless steel.

[0011] Furthermore, the sealing element prevents direct contact between the locking head and the side of the component facing the locking head. This is particularly advantageous with regard to preventing galvanic corrosion, especially when the blind rivet element and the side of the component facing the locking head are made of different metals or metal alloys.

[0012] Preferably, the sealing element rests against the shaft. In particular, the jacket portion of the sealing element rests against the shaft.

[0013] It is considered particularly advantageous if the sealing element is pot-shaped, in particular as a hollow cylinder closed on one side.

[0014] In a particularly preferred embodiment, a wall of the shaft in the region of the deformation section has a weakening, for example in the form of holes, slots or perforations, for the purpose of forming the deformation section.

[0015] It is considered particularly advantageous if, during the formation of the closing head, the jacket section of the sealing element deforms while maintaining the closed structure. It is entirely conceivable that the jacket section follows the deformation of the deforming section while reducing the material thickness. Deformation with the formation of a bead is also conceivable.

[0016] In a particularly preferred embodiment, the blind rivet element is made of a metal or a metal alloy.

[0017] It is considered particularly advantageous if the sealing element is made of a plastic, for example, a polymer. The plastic is, in particular, polyester.

[0018] The sealing element is made of a non-conductive material, which is particularly advantageous in preventing galvanic corrosion.

[0019] The material of the sealing element is in particular designed in such a way that it can follow the deformation of the deformation section without causing breakage or cracking of the sealing element.

[0020] It is considered particularly advantageous if the blind rivet element has a through-hole penetrating the blind rivet element in the axial direction.

[0021] It is provided that the cover section of the sealing element and the end of the shank of the blind rivet element facing away from the head section are spaced apart from one another in the axial direction. This is particularly advantageous with regard to deformation of the casing section upon deformation of the deformation section, since the distance enables a reduction in the axial extent of the sealing element without the end of the shank facing away from the head section exerting a force on the cover section. Furthermore, the distance between the cover section and the end of the shank facing away from the head section is advantageous in that a setting mandrel, a screw or another threaded connecting means can be introduced into the blind rivet element in such a way that the setting mandrel, the screw or the other connecting means completely penetrates the shank without the screw orthe other fastener acts on the cover section of the sealing element. This prevents the cover section from being damaged or even destroyed when the setting mandrel, screw, or other fastener is inserted into the blind rivet element.

[0022] The distance between the cover section and the end of the shaft is at least 1.0 times the pitch of the internal thread. Pitch, in this case, is understood to be the axial distance covered by one revolution, i.e., the distance between two thread crests. The distance is in particular at least 3.0 times, preferably 4.0 times, and more preferably 5.0 times the pitch of the internal thread.

[0023] It is considered particularly advantageous if the distance is at least 20% of the length of the shaft.

[0024] It is considered particularly advantageous if the shell section extends to the head section. This ensures that the sealing element is also positioned in the area of ​​the component's through-hole, improving the sealing effect and preventing direct contact between the component and the blind rivet element in this area.

[0025] In an advantageous development, the sealing element, preferably between the head section and the deformation section, in particular at its end facing away from the cover section, has a circumferential projection that projects radially outward relative to the casing section. Preferably, under the force of the head section, this radially outwardly projecting circumferential projection is pressed against the first component and clamped between the head section and the component when the blind rivet element is set, thereby achieving a particularly good sealing effect.

[0026] In this context, it is considered particularly advantageous if the projection protrudes radially outwards relative to the head section.

[0027] In an advantageous further development, the sealing element has a further casing section, wherein the further casing section encloses the head section of the blind rivet element all around.

[0028] Preferably, a portion of the further casing section protrudes opposite the axial direction relative to the head section. Preferably, the portion of the further casing section protruding opposite the axial direction is deformable radially inward such that, after radially inward deformation, it covers the head section in the axial direction. The deformation of the portion can occur, for example, during setting of the blind rivet element. However, it is also entirely conceivable to form the portion separately, for example, before or after setting the blind rivet element. The forming preferably takes place using the setting tool to be used to form the closing head.

[0029] In a preferred embodiment of the fastening means, the sealing element and the blind rivet element are permanently connected to one another. The sealing element and the blind rivet element are, in particular, bonded to one another.

[0030] In a preferred embodiment of the fastener, the sealing element is molded onto the blind rivet element. This allows the fastener to be manufactured particularly easily and cost-effectively.

[0031] In an alternative embodiment, the sealing element and the blind rivet element are detachably connected to one another. The sealing element and the blind rivet element are, in particular, connected to one another in a force-locking manner. Preferably, the blind rivet element is pressed into the sealing element.

[0032] In a particularly preferred embodiment, the blind rivet element and the sealing element form separate components. This has a beneficial effect on inventory management, since a separate blind rivet element, which can in principle also be used without a sealing element, can be used together with the sealing element when required. It is certainly conceivable that a separate blind rivet element is pressed into a separate sealing element to form the fastening means when required and, after pressing in, the blind rivet element and the sealing element are handled together. However, it is also conceivable that the sealing element is first inserted into the through-hole of the component and then the blind rivet element is inserted into the sealing element, thus forming the fastening means.

[0033] The sealing element is preferably made of a polymer, in particular of a thermoplastic polymer.

[0034] It is considered particularly advantageous if the blind rivet element is made of a metal or a metal alloy and the sealing element is made of a plastic, in particular a polymer, preferably polystyrene.

[0035] The sealing element is preferably formed in one piece.

[0036] The blind rivet element is preferably designed as a single piece.

[0037] In the following figures, the invention is explained in more detail using three exemplary embodiments, without being limited to these.

[0038] They show: Fig. 1 a first embodiment of a fastening means comprising a blind rivet element and a sealing element in a view according to the arrow I in Fig. 2 , Fig. 2 the fastening means in a view according to the arrow II in Fig. 1 , Fig. 3 the fastening means in a sectional view along the line III-III in Fig. 4, Fig. 4 the fastening means in a view according to the arrow IV in Fig. 3 , Fig. 5 an arrangement of a deformed fastening means according to Fig. 1 and a component in a view according to the arrow V in Fig. 6 , Fig. 6the arrangement according to Fig. 5 in a sectional view along the line VI-VI, Fig. 7 the blind rivet element of the fastening means according to Fig. 1 in a side view, Fig. 8 the sealing element of the fastening means according to Fig. 1 in a partially sectioned view Fig. 9 a second embodiment of the fastening means comprising a blind rivet element and a sealing element in a partially sectioned view, Fig. 10 an arrangement of a deformed fastening means according to Fig. 9 and a component in a sectional view, Fig. 11 the arrangement according to Fig. 10 with a deformed section of a further casing section, Fig. 12 the sealing element of the fastening means according to Fig. 9in a partially sectioned view Fig. 13 a design of the fastening means not covered by the scope of protection of the patent claims comprising a blind rivet element and a sealing element in a partially sectioned view, Fig. 14 an arrangement of a deformed fastening means according to Fig. 13 and a component in a sectional view.

[0039] The Fig. 1 to 6show a first embodiment of a fastening means 1 comprising a blind rivet element 2 designed as a blind rivet nut and a sealing element 3, wherein the blind rivet element 2 has a head section 4 and a shaft 5 adjacent to the head section 4 in an axial direction Z. The shaft 5 has an internal thread 6 and a deformation section 7 between the internal thread 6 and the head section 4. The deformation section 7 is formed in the present case in that a wall 8 of the shaft 5 in the region of the deformation section 7 has a weakening in the form of four holes 9. The deformation section 7 serves to form a closing head 10 upon deformation of the deformation section 7. In the Fig. 1 to 4 , as well as 7, the blind rivet element 2 is in an undeformed state, thus in a state before setting the blind rivet element 2.

[0040] The sealing element 3 is pot-shaped in the present case, namely designed as a hollow cylinder closed on one side, wherein the sealing element 3 has a closed jacket section 11 and a closed cover section 12 adjacent to the jacket section 11 in the axial direction Z. The jacket section 11 extends in the present case to the head section 4 and encloses the shaft 5 of the blind rivet element 2 all the way around and in particular rests all the way around the shaft 5. The cover section 12 is formed on an end 13 of the shaft 5 of the blind rivet element 2 facing away from the head section 4. For the purpose of providing a thread in a component 16, the fastening means 1 is introduced into a prefabricated receiving opening of the component 16 and then the deformation section 7 is deformed to form the closing head 10. As in particular the Fig. 6, which shows an arrangement of the fastening means 1 and the component 16, the casing section 11 of the sealing element 3 deforms during the formation of the closing head 10 of the blind rivet element 2 in such a way that the casing section 11 retains its closed structure with the formation of a bead 17.

[0041] Due to the sealing element 3, after deformation of the blind rivet element 2, a first side of the component 16, which is associated with the head section 4 of the blind rivet element 2 and into which the fastening means 1 is inserted, is separated in a fluid-tight manner from a second side of the component 16, which is remote from the first side of the component 16 and is associated with the closing head 10. In this respect, no flow of fluid from the first side of the component 16 towards the second side of the component 16 and vice versa through the receiving opening into which the fastening means 1 is inserted is possible. Furthermore, as in particular the Fig. 6As can be seen, the blind rivet element 2 is separated by the sealing element 3 from the environment or atmosphere prevailing on the second side of the component 16, or is not exposed to this atmosphere or environment. For example, the second side could be the inside of a tank in which a liquid or gas is stored. Because the sealing element 3 seals the blind rivet element 2 from the environment prevailing on the second side of the component 16, a fastening element introduced into the blind rivet element 2, for example a screw, is also sealed from this environment.

[0042] The blind rivet element 2 in the present case has a through-opening 14 which penetrates the blind rivet element 2 in the axial direction Z. In this respect, the blind rivet element 2 enables, for example, a screw or a setting mandrel inserted into the blind rivet element 2 to axially penetrate the blind rivet element 2 and thus protrude relative to the end 13 of the shaft 5 in the axial direction Z. Because the cover section 12 of the sealing element 3 and the end 13 of the shaft 5 facing away from the head section 4 are spaced apart in the axial direction Z, the screw or the setting mandrel inserted into the blind rivet element 2 can protrude relative to the end 13 in the axial direction Z without damaging the cover section 12 when the screw or the setting mandrel is inserted.

[0043] The sealing element 3 has, at its end facing away from the cover section 12, a circumferential projection 15 projecting radially outwardly relative to the casing section 11, wherein the projection 15 projects radially outwardly relative to the head section 4. The blind rivet element 2 and the sealing element 3 may well form separate components, as shown in the Figs. 7 and 8 is shown.

[0044] The Figures 9 to 11show a second embodiment of a fastening means 1. This second embodiment differs from the first embodiment essentially in the design of the sealing element 3, which has a further casing section 18, wherein the further casing section 18 circumferentially surrounds the head section 4 of the blind rivet element 2 and a partial area of ​​the casing section 18 protrudes opposite the axial direction Z relative to the head section 4. The partial area of ​​the further casing section 18 protruding opposite the axial direction Z is deformable radially inwardly in such a way that after deformation radially inwardly it covers the head section 4 in the axial direction Z, as is the case with the Fig. 11 The deformation of the partial area takes place in a separate process step after setting the blind rivet element 2, as a comparison of the Figs. 10 and 11 shows.

[0045] The Figures 13 and 14show a design of the fastening means 1 not covered by the scope of protection of the patent claims, this design differing from the second embodiment essentially in the design of the blind rivet element 2, which in the present case is designed as a blind rivet threaded bolt, in that the shaft 5 has a connecting section 19 for a threaded bolt 20. List of reference symbols

[0046] 1Fastener 2Blind rivet element 3Sealing element 4Head section 5Shaft 6Internal thread 7Deformation section 8Wall 9Hole 10Closing head 11Shell section 12Cover section 13End 14Through opening 15Protrusion 16Component 17Bead 18Shell section 19Connecting section 20Threaded bolt Zaxial direction

Claims

1. Fastening means (1) having a blind rivet element (2) and a sealing element (3), wherein the blind rivet element (2) has a head portion (4) and a shaft (5) adjoining the head portion (4) in an axial direction (Z), characterized in that the shaft (5) has an internal thread (6) and, between the internal thread (6) and the head portion (4), a deformation portion (7), for forming a closing head (10) when the deformation portion (7) is deformed, wherein the sealing element (3) has a closed lateral portion (11) and a closed cover portion (12) adjoining the lateral portion (11) in the axial direction (Z), wherein the lateral portion (11) circumferentially encloses the shaft (5) of the blind rivet element (2) at least in the region of the deformation portion (7), and the cover portion (12) is formed at an end (13) of the shaft (5) of the blind rivet element (2), said end facing away from the head portion (4), wherein the cover portion (12) of the sealing element (3) and that end (13) of the shaft (5) of the blind rivet element (2) which faces away from the head portion (4) are spaced apart in the axial direction (Z), wherein the distance between the cover portion (12) and the end (13) of the shaft (5) is at least 1.0 times the pitch of the internal thread (6).

2. Fastening means according to Claim 1, wherein the sealing element (3) is pot-shaped, in particular is configured in the form of a hollow cylinder which is closed on one side.

3. Fastening means according to Claim 1 or 2, wherein, during the formation of the closing head (10), the lateral portion (11) of the sealing element (3) is deformed while maintaining the closed structure.

4. Fastening means according to one of the preceding claims, wherein the blind rivet element (2) is manufactured from a metal and the sealing element (3) is manufactured from a plastic.

5. Fastening means according to one of the preceding claims, wherein the blind rivet element (2) has a passage opening (14) which passes through the blind rivet element (2) in the axial direction (Z).

6. Fastening means according to one of the preceding claims, wherein the distance between the cover portion (12) and the end (13) of the shaft (5) is 2.0 to 3.0 times the pitch of the internal thread (6).

7. Fastening means according to one of the preceding claims, wherein the lateral portion (11) extends up to the head portion (4).

8. Fastening means according to one of the preceding claims, wherein the sealing element (3) has a circumferential projection (15) which protrudes radially outwardly in relation to the lateral portion (11).

9. Fastening means according to one of the preceding claims, wherein the sealing element (3) has a further lateral portion (18), wherein the further lateral portion (18) circumferentially encloses the head portion (4) of the blind rivet element (2).

10. Fastening means according to Claim 9, wherein a partial region of the further lateral portion (18) protrudes counter to the axial direction (Z) in relation to the head portion (4).

11. Fastening means according to one of the preceding claims, wherein the sealing element (3) and the blind rivet element (2) are connected to one another in a non-releasable manner.

12. Fastening means according to Claim 11, wherein the sealing element (3) is injection-moulded onto the blind rivet element (2).

13. Fastening means according to one of Claims 1 to 10, wherein the sealing element (3) is connected to the blind rivet element (2) in a releasable manner.

14. Fastening means according to one of Claims 1 to 10 and / or 13, wherein the blind rivet element (2) and the sealing element (3) form separate components.

15. Fastening means according to one of the preceding claims, wherein the sealing element (3) is manufactured from a polymer.