BOLT AND FASTENING ARRANGEMENT

Description

Technical area

[0001] The invention generally relates to a device and a method for fastening a bolt to a substrate and to such a bolt, see, for example, US 2004 / 105735 A1. State of the art

[0002] Numerous devices and methods are known for attaching various bolts to a substrate for various applications. For example, a bolt is brought into contact with the substrate and subjected to an electric current. As soon as the electric current flows between the bolt and the substrate, the bolt is lifted from the substrate, forming an arc. The released energy causes the material of the bolt and the substrate to partially liquefy. The electric current is then switched off, and the bolt is immersed in the liquefied material, while this material cools and solidifies. The bolt is then firmly bonded to the substrate.

[0003] To provide the necessary energy to liquefy the material of the bolt and the substrate in a sufficiently short time, devices are known that generate a very high-intensity electric current and supply it to the bolt via an appropriately dimensioned electrical cable. To prevent oxidation of the liquefied material, it is known to purge the contact point between the bolt and the substrate with an inert gas.

[0004] In applications such as building or ship construction, bolts of various sizes with a thread are used, into which an object is screwed to fasten the object to the substrate. Some parameters of the fastening process, such as the duration and electrical power of the electrical current, must be adjusted by the user on the device and adapted to the bolt used. Finally, the user assesses the quality of the connection between the bolt and the substrate through a visual inspection. The quality of the connection therefore also depends on the user's experience and skills.

[0005] For bolts that have a sealing ring, it is important to ensure that the sealing ring is sufficiently compressed after fastening to achieve a sufficient sealing effect. On the other hand, the sealing ring should not be overcompressed to avoid excessive deformation. Description of the invention

[0006] The object of the invention is to provide a device and / or a method for improving the fastening of a bolt to a substrate. In particular, an area of ​​the fastening is to be reliably sealed.

[0007] This object is achieved in a bolt for fastening a connecting element to a substrate, comprising a shaft defining a fastening direction, a sealing element for sealing a contact zone between the shaft and the substrate, and a force transmission element for transmitting compressive forces from the connecting element to the substrate according to claim 1. The force transmission element may transmit a connecting force and / or a lateral force perpendicular to the fastening direction and / or a bending moment about an axis perpendicular to the fastening direction and / or a torque about an axis parallel to the fastening direction of the connecting element to the substrate, such that the sealing element is not subjected to the respective force or moment. The sealing element is preferably made of an elastic material such as an elastomer, for example rubber or EPDM.The force transmission element is preferably made of a rigid material such as a metal, an alloy, ceramic or the like.

[0008] According to the invention, the force transmission element has a support surface for supporting the connecting element on the force transmission element and a support surface for supporting the force transmission element on the ground.

[0009] The force transmission element also has a pressure surface for pressing the sealing element against the substrate. The distance between the pressure surface and the support surface is smaller in the fastening direction than the length of the sealing element in the fastening direction. The ratio of the distance between the pressure surface and the support surface to the length of the sealing element is preferably between 50% and 90%.

[0010] According to the invention, the cross-sectional area of ​​the sealing element decreases perpendicular to the fastening direction along the fastening direction. As a result, the sealing surface between the sealing element and the substrate increases with increasing pressure force with which the sealing element is pressed against the substrate.

[0011] An advantageous embodiment is characterized in that the bolt is a welding bolt, a set bolt or a screw bolt.

[0012] An advantageous embodiment is characterized in that the sealing element is annular, wherein the sealing element rests on the inside of the shaft and / or rests on the outside of the force transmission element.

[0013] An advantageous embodiment is characterized in that the force transmission element is ring-shaped.

[0014] An advantageous embodiment is characterized in that the sealing element and / or the force transmission element is circular.

[0015] An advantageous embodiment is characterized in that the bolt has a thread for screwing the connecting element onto the bolt

[0016] An advantageous embodiment is characterized in that the bolt is inserted into a fastening arrangement comprising a substrate and a connecting element. Preferably, the force transmission element is clamped between the connecting element and the substrate. Examples of implementation

[0017] The invention is explained in more detail below using exemplary embodiments with reference to the drawings. They show: Fig. 1 schematically shows a welding device, Fig. 2 a welding stud in a longitudinal sectional view, Fig. 3 a welding stud according to the invention in a longitudinal sectional view and Fig. 4 a welding stud in a longitudinal sectional view.

[0018] In Fig. 1A welding device 10 for welding a welding stud 20 to a substrate 30 is schematically shown. A material of the welding stud 20 and a material of the substrate 30 are electrically conductive, in particular metallic. The welding device 10 comprises a welding gun 40 with a trigger switch 41 designed as a push-button switch, a welding device 50, a first electrical cable 61, a second electrical cable 62 with a connection terminal 63, an electrical supply cable 64 designed, for example, as a power cable, an electrical communication line 65, a gas reservoir 70 designed as a gas cylinder, a tubular gas supply line 71, and a gas hose 72.

[0019] The first cable 61 serves to supply the welding stud 20 with electrical current via the welding device 50. The second cable 62 serves to electrically connect the base 30 to the welding device 50 when the connecting terminal 63 is clamped to the base 30. When the welding stud 20 comes into contact with the base 30, an electrical circuit is closed, so that the welding stud 20 can be subjected to welding current from the welding device 50, which can be, for example, direct current or alternating current. For this purpose, the welding gun 40 comprises a Fig. 1Welding current contact element (not shown). The welding device 50 includes a device (not shown) for converting electrical current from the supply cable 64 into welding current, which includes, for example, an electrical capacitor, a thyristor, an insulated-gate bipolar transistor, or other power electronic components, as well as an associated control unit with a microprocessor to provide the welding current with the desired voltage and current.

[0020] The gas supply line 71 and the gas hose 72 serve to supply a contact area between the welding stud 20 and the substrate 30 with a shielding gas from the gas reservoir 70 in order to protect the contact area from oxidation by ambient oxygen during a welding process. To control the gas flow to the contact area, the gas reservoir 70, the gas supply line 71, the welding device 50, the gas hose 72, or the welding gun 40 comprise a valve (not shown), in particular a controllable valve.

[0021] The welding device 50 has an input device 51 with actuating elements 52 and an output device 53 with a visual display element 54 and a wireless transmission unit. The input device 51 serves to allow a user of the welding device 10 to input parameters of a welding process to be performed with the welding device 10, such as the electrical voltage, current intensity, power and duration of the welding current, the position and speed of the stud, and so on.The output device 53 serves to output information, such as information about parameters of the welding process, information about recorded emissions of the welding process or other variables, information about a quality of the welding process, information about measures to improve the welding process, information about recorded properties of the welding stud or information derived from the aforementioned variables, and / or recommendations or instructions for cleaning and / or maintenance of the welding device 10, in particular the welding gun 40, to the user.

[0022] The communication line 65 is used for communication between the welding gun 40, in particular a Fig. 1not shown control device of the welding gun 40, and the welding device 50, in particular the control device and / or the input device 51 and / or the output device 53. This communication, for example, accomplishes an exchange of information about the parameters of a welding process in order to achieve or facilitate, for example, a synchronization of the welding current with a movement of the welding stud 20. In embodiments not shown, the communication between the welding gun and the welding device occurs wirelessly, by radio, or by means of the first electrical cable that carries the welding current.

[0023] The welding gun 40 has a housing 42 with a mouth 46, from which a handle 43 with the trigger switch 41 protrudes. The welding gun 40 further has a stud holder 44, on which the welding stud 20 is held during a welding process. For this purpose, the stud holder comprises, for example, two, three, four, or more resilient arms (not shown in detail), between which the welding stud 20 is inserted and held by a clamp fit. The welding gun 40 further has a welding current contact element for applying a welding current to the welding stud 20, which is integrated into the stud holder 44, for example in the form of one or more of the resilient arms.

[0024] The welding gun 40 further includes a control device 99 for controlling the various components and devices of the welding gun and the welding device 50. The control device 99 is provided for controlling one or more parameters of the welding process. For this purpose, the control device 99 comprises various electronic components, such as one or more microprocessors, one or more temporary or permanent data memories, and the like.

[0025] The welding gun 40 further comprises a stud lifting device designed as a first lifting magnet, which moves the stud holder 44 with a force away from the muzzle 46 to the rear (in Fig. 1 upwards) when the bolt lifting device is activated. The control device 99 communicates with the bolt lifting device via a signal line (not shown) in order to control the bolt lifting device, in particular to activate and deactivate it.

[0026] The welding gun 40 further comprises a stud insertion device designed as a spring element or as a second lifting magnet, which pushes the stud holder 44 forwards (in Fig. 1 downwards) when the stud insertion device is activated. The control device 99 communicates with the stud insertion device via a signal line (not shown) in order to control the stud insertion device, in particular to activate and deactivate it. If the stud insertion device is designed as a spring element, this spring element is preferably tensioned when the stud holder is moved rearward by the stud lifting device, so that the spring element moves the stud holder forward as soon as the stud lifting device is deactivated.

[0027] In a welding process using the welding device 10, the substrate 30 and the stud 20 are first provided. In a further step, a user enters information via the input device, for example, information about desired parameters of the subsequent welding process. In a further step, the welding stud 20 is subjected to a welding current between the welding stud 20 and the substrate 30 by the welding device 50 using the first cable 61 and the second cable 62. In a further step, the welding stud 20 is lifted from the substrate by the stud lifting device while maintaining the welding current flowing between the welding stud 20 and the substrate 30, whereby an arc forms between the welding stud 20 and the substrate 30.In particular, due to the heat generated by the arc, a material of the welding stud 20 and / or the substrate 30 is then partially liquefied. In a further step, the welding stud 20 is immersed into the liquefied material of the welding stud 20 or the substrate 30 by means of the stud immersion device. The liquefied material of the welding stud 20 or the substrate 30 then solidifies, so that the welding stud 20 is firmly bonded to the substrate 30.

[0028] In Fig. 2A fastening arrangement 100 with a connecting element 150, a substrate 200, and a bolt 210 for fastening the connecting element 150 to the substrate 200 is shown in a longitudinal section. The bolt 210 has a shaft 230 defining a fastening direction 220, a sealing element 240 for sealing a contact zone 250 between the shaft and the substrate, and a force transmission element 260 for transmitting compressive forces from the connecting element 150 to the substrate 200. The annular sealing element 240 rests on the inside against the shaft 230 and on the outside against the likewise annular force transmission element 260.

[0029] The bolt 210 is designed, for example, as a welding bolt, set bolt, or screw bolt, wherein the contact zone 250 is then designed as a weld seam, joint gap, or other joint, and is provided with a thread 211. A retaining element 160 designed as a screw nut is attached to the bolt 210, in the present example, screwed onto the thread 211, in order to fix the connecting element 150 to the bolt 210 and thus to the substrate 200.

[0030] The force transmission element 260 has a bearing surface 261 for supporting the connecting element 150 on the force transmission element 260 and a support surface 262 for supporting the force transmission element 260 on the substrate. A distance a between the bearing surface 261 and the support surface 262 in the fastening direction 220 is exactly as long as a length of the sealing element 240 in the fastening direction 220. As a result, the force transmission element 260 transmits a connection force of the connecting element to the substrate without subjecting the sealing element to the full connection force. The force transmission element 260 is then clamped between the connecting element 150 and the substrate 200.

[0031] The force transmission element 260 merely transmits a pressing force to the sealing element 240 in order to press the sealing element 240 against the substrate 200. For this purpose, the force transmission element 260 has a pressing surface 263, the distance b of which from the support surface 262 in the fastening direction 220 is smaller than a length of the sealing element 240 in the fastening direction 220 when the sealing element 240 is relaxed. A ratio of the distance b to the length of the relaxed sealing element is, for example, 75%. The sealing element 240 is then compressed accordingly to exert its sealing effect. The sealing effect is independent of the connection force, thus also independent of a force with which the holding element 160 is fastened to the bolt 210.

[0032] In Fig. 3A bolt 310 for fastening a connecting element (not shown) to a substrate (not shown) is shown in a longitudinal section. The bolt 310 has a shaft 330 defining a fastening direction, a sealing element 340 for sealing a contact zone between the shaft 330 and the substrate, and a force transmission element 360 for transmitting compressive forces from the connecting element to the substrate. The annular sealing element 340 rests on the inside of the shaft 330 and on the outside of the likewise annular force transmission element 360.

[0033] The force transmission element 360 has a support surface 361 for supporting the connecting element on the force transmission element 360 and a support surface 362 for supporting the force transmission element 360 on the substrate. An end face 341 of the sealing element 340 facing in the fastening direction is beveled, so that a cross-sectional area of ​​the sealing element 340 decreases perpendicular to the fastening direction along the fastening direction. As a result, the sealing surface between the sealing element 340 and the substrate increases with increasing pressure force with which the sealing element 340 is pressed against the substrate.

[0034] In Fig. 4A bolt 410 for fastening a connecting element (not shown) to a substrate (not shown) is shown in a longitudinal section. The bolt 410 has a shaft 430 defining a fastening direction, a sealing element 440 for sealing a contact zone between the shaft 430 and the substrate, and a force transmission element 460 for transmitting compressive forces from the connecting element to the substrate. The annular sealing element 440 rests on the inside of the shaft 430 and on the outside of the likewise annular force transmission element 460.

[0035] The force transmission element 460 has a support surface 461 for supporting the connecting element on the force transmission element 460 and a support surface 462 for supporting the force transmission element 460 on the substrate. An end face 441 of the sealing element 440 facing in the fastening direction has two circumferential recesses 4432, in particular grooves, so that a cross-sectional area of ​​the sealing element 440 decreases perpendicular to the fastening direction along the fastening direction. As a result, the sealing surface between the sealing element 440 and the substrate increases with increasing pressure force with which the sealing element 440 is pressed against the substrate.

[0036] The sealing element is preferably manufactured by cutting from sheet material, embossing, injection molding, or similar processes. Especially in injection molding, targeted shaping is advantageous, allowing the surface pressure of the sealing element to be locally increased and / or the surface pressure profile to be adjusted over a contact pressure path in such a way that the sealing function is ensured even with varying contact pressure paths.

[0037] To avoid damage to any existing substrate coating, in one embodiment not shown, a radially outer region of the sealing element protrudes between the force transmission element and the substrate. In other embodiments not shown, the sealing element and the force transmission element are made in one piece from the same material. For example, by suitable shaping (in particular with grooves as in Fig. 4shown) an initially elastic behavior with the contact pressure and later a significantly increased stiffness is achieved.

[0038] The invention has been described using examples of a device for fastening a first object to a second object. The features of the described embodiments can also be combined with one another as desired within a single fastening device or a single manufacturing method. It should be noted that the device according to the invention is also suitable for other purposes.

Claims

1. Stud (310) for fastening an attachment element to an underlying surface, having a shank (330) which defines a fastening direction, having a sealing element (340) for sealing off a contact zone between the shank (300) and the underlying surface, and having a force-transmission element (360) for transmitting compressive forces of the attachment element to the underlying surface, wherein the force-transmission element (360) has a bearing surface (361) for bearing of the attachment element on the force-transmission element (360) and has a support surface (362) for support of the force-transmission element (360), wherein the force-transmission element (360) has a contact-pressure surface for pressing of the sealing element (340) against the underlying surface, characterized in that the support surface (362) of the force-transmission element (360) is configured for support of the force-transmission element (360) on the underlying surface, wherein a distance between the contact-pressure surface and the support surface (362) in the fastening direction is less than a length of the sealing element (340) in the fastening direction, and wherein a cross-sectional area of the sealing element (340) perpendicular to the fastening direction decreases along the fastening direction.

2. Stud (310) according to Claim 1, wherein a distance between the bearing surface (361) and the support surface (362) in the fastening direction is greater than or equal to a length of the sealing element (340) in the fastening direction.

3. Stud (310) according to Claim 1, wherein a ratio of the distance between the contact-pressure surface and the support surface (362) to the length of the sealing element (340) lies between 50% and 90%.

4. Stud (310) according to one of the preceding claims, wherein the stud (310) is welding stud, a setting stud or a bolt.

5. Stud (310) according to one of the preceding claims, wherein the sealing element (340) is of ring-shaped form, and wherein the sealing element (340) bears internally against the shank and / or bears externally against the force-transmission element (360).

6. Stud (310) according to one of the preceding claims, wherein the force-transmission element (360) is of ring-shaped form.

7. Stud (310) according to one of the preceding claims, wherein the sealing element (340) and / or the force-transmission element (360) are / is circular.

8. Stud (310) according to one of the preceding claims, wherein the stud (310) has a thread for firm screwing of the attachment element on the stud.

9. Fastening arrangement having an underlying surface, having a stud (310) and having an attachment element, wherein the stud (310) is designed according to one of the preceding claims.

10. Fastening arrangement according to Claim 9, wherein the force-transmission element (360) is clamped between the attachment element and the underlying surface.