Modular feed head system, joining device with feed head system

Abstract

The invention relates to a feed adapter for a joining device, in particular a flow drilling device. The feed adapter has an inlet opening, an outlet opening and an axial hollow body between the inlet opening and the outlet opening. The inlet opening of the feed adapter can be coaxially detachably coupled to a feed head of the joining device in such a way that the feed adapter guides a joining means provided by the feed head, in particular a flow hole screw, to the outlet opening within the hollow body during a joining process. The invention further relates to a modular feed head system and to a joining device having the modular feed head system.

Description

[0001] Modular feed head system, joining device with feed head system

[0002] The invention relates to a feed adapter for a joining device, in particular a flow drilling device, a feed head corresponding thereto, as well as a modular feed head system comprising the feed adapter and the feed head, and a joining device comprising the modular feed head system.

[0003] Technical background

[0004] Body designs are becoming increasingly sophisticated to reduce carbon dioxide emissions and increase crash safety. This leads to more complex manufacturing processes. Multiple materials with different strength properties must be combined, such as high-strength steel, aluminum, cast iron, magnesium, carbon, or plastics. At the same time, limited accessibility and short cycle times within the manufacturing process pose challenges.

[0005] Flow-drill fastening (FDF) is a solution to these challenges. This technology offers multi-material, single-sided access connections, using a fastener as both the drilling and fastening element. The fastener is rotated at high speed and pressurized to heat the material. This allows the fastener to be pushed through the material stack, forming a thread—an efficient and flexible joining process. Appropriate FDF system solutions can ensure precise operation of the joining process in harsh production environments.

[0006] The use of automated or semi-automated FDF system solutions with integrated feeding to create a detachable connection in the field of flow drilling screws requires a device to provide the corresponding fastening or joining elements. This device, referred to below as the feeding head or hold-down device, must be adapted according to the requirements of the component to be machined and the ambient conditions. Fig. 1 shows a 3D representation of a longitudinal section through a hold-down device 20 from the prior art. During the warm-up phase of the joining process, the fastening element is located in a bushing 24 in the front area of ​​the hold-down device or is guided by the hold-down device. Due to the rotation of the fastening element at high speed under pressure in the hold-down device, the hold-down device, in particular its inner surface in the head area, is subject to high wear.

[0007] Clamps are customized to specific project situations and are therefore rarely produced on a large-scale industrial scale. Consequently, it makes sense to recondition used clamps through a repair process rather than replacing them with new ones. However, reconditioning a worn clamp involves removing the clamp from the production line and undergoing complex heat treatment, which is why longer waiting times tend to be expected. Thus, even reconditioning a clamp can be costly.

[0008] Specifically, the wear in used blank holders is determined at regular intervals using a gauge. Once a predetermined level of wear is reached, the corresponding blank holder is reworked. However, only the area of ​​the bushing 24 of the blank holder 20 can be reworked, not the attached head structure. Thus, reconditioning the blank holder can only produce a partially renewed blank holder at most. A further disadvantage of conventional reconditioning technology is that it can only be used a maximum of twice per blank holder. Previously known blank holders cannot be reconditioned a third time.

[0009] Summary of the invention

[0010] There is therefore a need for a hold-down system that ensures efficient and cost-optimized operation despite high wear.

[0011] This object is achieved by the feed adapter as well as the associated feed head system and the associated joining device according to the independent claims. Advantageous embodiments of the method are defined in the respective dependent claims. According to one aspect of the invention, a feed adapter for a joining device, in particular a flow drilling device, is provided.

[0012] The feed adapter has an inlet opening, an outlet opening, and an axial hollow body between the inlet opening and the outlet opening. The inlet opening of the feed adapter can be releasably coupled coaxially to a feed head of the joining device, such that the feed adapter guides a joining agent provided by the feed head within the hollow body to the outlet opening during a joining process.

[0013] The joining process can in particular be a flow hole screwing process, which can include the following process steps to form a flow hole forming screw connection:

[0014] - Heating a surface of the workpiece by setting the joining material into a high-frequency rotational movement (up to 9000 revolutions per minute) and applying a vertically directed force to the rotating joining material,

[0015] - Pressing the joining agent with high process force or contact force (up to 3000 N) into the heated surface through the material stack of the workpiece, thereby braking the rotational movement of the joining agent and radially displacing the material stack,

[0016] - forming a thread in the displaced material stack,

[0017] - Tightening the joining element in the formed thread with a predetermined torque.

[0018] The flow hole screwing process can be carried out for workpieces made of long-chipping metallic materials such as steel, copper, aluminum and / or brass, etc.

[0019] The joining means or fastening / connecting means may be a screw, in particular a flow-drilling screw, wherein the joining means is adapted to first be drilled into the workpiece and then to be fastened in the workpiece by means of a screw connection.

[0020] The feed adapter is adapted to form a contact structure for the foremost, output-side section of a feed head or hold-down device. Due to the detachable coupling or connection to the feed head, the feed adapter is replaceable according to one aspect of the invention. The joining agent can be guided in the feed adapter during the joining process, i.e., it can be set into a high-frequency rotary motion of up to 9,000 revolutions per minute and subjected to a high, essentially vertically directed process force / contact force. Thus, the wear of a cost-intensive and customer-specific hold-down device can be transferred to the feed adapter by the feed adapter protecting the wear-prone bushing of the feed head. In other words, by using the feed adapter according to the invention, the feed head can be protected from high levels of wear by essentially exposing only the feed adapter to the high levels of wear.When a feed adapter is worn, it can be replaced more easily. Unlike the feed head, the feed adapter is a less complex component that can be manufactured more cost-effectively. Furthermore, replacing a feed adapter does not require the feed head to be removed from the production line. Therefore, the feed adapter can at least partially reduce downtimes or production losses due to the high wear on the blank holders. This lowers replacement costs, conserves resources, and significantly reduces maintenance times.

[0021] The minimum width of the entry opening, the axial hollow body, and the exit opening is preferably adapted to the joining material to be used, such as a flow-hole screw. The entry opening is preferably round.

[0022] In one embodiment, the hollow body is formed, at least in sections, as a hollow cylinder. The hollow cylinder design allows the feed adapter to be more easily coupled to a head region of the feed head. Typically, the head region of the feed head is essentially cylindrical.

[0023] In one embodiment, the hollow body further comprises an attachment structure arranged axially on the hollow cylinder and encompassing the outlet opening. The attachment structure is preferably arranged on the outlet side of the hollow cylinder and / or firmly connected to the hollow cylinder. The attachment structure is adapted to attach the joining means to the workpiece in a predetermined position from which the joining process described above can be started.

[0024] In one embodiment, the exit opening is arranged at a predetermined axial distance from the hollow cylinder. The predetermined distance can, for example, be between the exit of the hollow cylinder and the exit opening. The predetermined distance can be determined by the length of the joining material to be processed, such that an upper section of the joining material is still located in the hollow cylinder when it is applied to the workpiece.

[0025] Preferably, the joining element is a flow-drilling screw, with the upper section of the flow-drilling screw comprising a screw head. The screw head typically has the greatest radial extension of the flow-drilling screw and, by being arranged in the hollow cylinder, can stabilize the flow-drilling screw during rotation or prevent displacement of the flow-drilling screw.

[0026] The outlet opening can be formed by a ring, wherein the ring is firmly connected to the wooden cylinder by means of at least one web, preferably two oppositely arranged, flat webs. The outlet opening is preferably round.

[0027] In one embodiment, the attachment structure comprises at least one radial opening for dissipating heat generated during the joining process, particularly during the warm-up and drilling phases. Preferably, the attachment structure comprises two opposing radial openings or windows, wherein a web for radial coverage can be provided between each of the openings.

[0028] In one embodiment, the attachment structure comprises a half-space that is open in the radial direction. In this embodiment, a structure defining the exit opening is preferably connected to the hollow cylinder by a single flat web. Due to the open half-space, the process heat can escape even more effectively.

[0029] In one embodiment, the hollow cylinder and / or the attachment structure comprises an abrasion-resistant and / or heat-resistant material, which preferably has a melting temperature of at least 300°C.

[0030] In one embodiment, the hollow cylinder can comprise a magnet and / or be formed at least partially from a magnetic material. This allows the feed adapter to be efficiently attached to the feed head with a correspondingly opposite-polarity magnetic connector in the feed head.

[0031] In one embodiment, the feed adapter further comprises at least one attachable protective structure which is arranged on the output side at the output opening and covers a surface of the attachment structure at least in section. The protective structure preferably covers at least that surface of a structure defining the output opening which comes into direct contact with the workpiece, i.e. which is attached to the workpiece when the connection method described above is carried out. The protective structure can prevent the feed adapter from causing scratch marks in the processing area. In FDF-Sy stars, the feed adapter can be attached to the workpiece, e.g. a sensitive body component, as the foremost tip of a robot arm. Due to the robot displacement, scrapes and scratches can therefore be left on the surface of the workpiece. Such damage should be avoided at all costs.The protective structure therefore preferably has a scratch-resistant coating.

[0032] In one embodiment, the scratch-resistant coating is formed by a vulcanized rubber coating or rubber layer.

[0033] In one embodiment, the protective structure is detachably arranged on the attachment structure, for example, by means of a clamp or clip connection. For this purpose, the protective structure can have two wings, each comprising a connecting means by which each wing can be detachably attached to a web of the feed adapter.

[0034] According to a further aspect of the invention, a feed head is also provided which is adapted to receive a joining means, in particular a flow-hole screw, and to make it available for a joining process, in particular a flow-hole screwing process. The feed head comprises a guide channel which preferably has a round cross-section. The feed head has an axial opening which is adapted to be at least partially positively coupled to a hollow body of a feed adapter. The feed head preferably comprises a bushing with a round cross-section at its front end, i.e. on the output side. In contrast to a feed head from the prior art, the feed head according to one aspect of the invention alone, i.e. without a coupled feed adapter, is not suitable for carrying out the joining process, in particular the flow-hole forming screw connection.

[0035] According to a further aspect of the invention, a modular feed head system for a joining device, in particular a flow-hole screwing device, is provided. The feed head system comprises a feed head adapted to receive a joining means, in particular a flow-hole screw, and to provide it for a joining process, in particular a flow-hole screwing process. The feed head system further comprises a feed adapter, as described above. The feed head has an axial opening adapted to be at least partially positively coupled to the hollow body of the feed adapter. Furthermore, the feed adapter is detachably coupled to the feed head.

[0036] Preferably, the feed adapter is at least partially received in a form-fitting manner by the feed head. In an alternative embodiment, the feed adapter can accommodate the end of the feed head. For this purpose, the feed adapter and the feed head each have corresponding interfaces.

[0037] In one embodiment, the feed adapter comprises, at least in sections, a hollow cylinder, which also forms the inlet opening of the feed adapter. For this purpose, the feed head can be adapted to completely accommodate the hollow cylinder of the feed adapter in a form-fitting manner. This ensures a secure coupling of the feed adapter to the feed head, which can withstand even high-frequency rotation of the joining material and high process forces.

[0038] In one embodiment, the hollow cylinder has a radial projection, and the axial opening of the feed head has a radial recess that corresponds to the projection of the feed adapter. When the feed adapter is coupled to the feed head, the projection is at least partially received in the recess. This provides a fixed orientation for coupling the feed adapter to the feed head, and also prevents the feed adapter from rotating relative to the feed head. The projection, which is at least partially received in the recess, further increases safety when using the feed head system during operation. Preferably, the feed adapter can be fastened to the feed head by means of a clamping means. This fastening prevents the feed adapter from falling out or being accidentally released during operation.

[0039] According to a further aspect of the invention, a joining device is provided. The joining device comprises a feed head system as described above, a drive and / or pressing unit for driving and / or pressing the joining means, and a control unit. The control unit is adapted to control the drive and / or pressing unit in order to process the joining means into a joining connection by means of the feed head system.

[0040] Short description of the characters

[0041] The invention, or further embodiments and advantages of the invention, are explained in more detail below with reference to drawings, which only describe embodiments of the invention. Identical components are provided with the same reference numerals in the drawings. Elements drawn with dashed lines are considered optional elements.

[0042] The drawings are not to be considered to scale, and individual elements of the drawings may be exaggeratedly large or simplified.

[0043] Fig. 1 shows a 3D view of a longitudinal section through a hold-down device from the prior art.

[0044] Fig. 2a and Fig. 2b show a first embodiment of the feed adapter according to one aspect of the invention.

[0045] Fig. 2c shows a second embodiment of the feed adapter according to one aspect of the invention.

[0046] Fig. 3a and Fig. 3b show an embodiment of the feed head according to one aspect of the invention.

[0047] Fig. 3c shows a front view of an embodiment of the feed adapter according to one aspect of the invention. Fig. 4 shows a top view, a side view, and a longitudinal section along the section axis AA of an embodiment of a feed head system according to one aspect of the invention without a mounted feed adapter.

[0048] Fig. 5 shows a top view, a side view and a longitudinal section along the section axis A-A of an embodiment of a feed head system according to one aspect of the invention with a mounted feed adapter.

[0049] Fig. 6a shows a partially exploded view of an embodiment of a feed head system in which the feed head of Fig. 3a is arranged.

[0050] Fig. 6b shows the embodiment of the feed head system from Fig. 4b in the assembled state.

[0051] Detailed description of the characters

[0052] Fig. 1 shows a 3D view of a longitudinal section through a hold-down device from the prior art, which has the disadvantages described in the introductory part.

[0053] Fig. 2a shows a first embodiment of a feed adapter according to one aspect of the invention.

[0054] The feed adapter 10 of Fig. 2a comprises, on the input side, a hollow cylinder 11 that defines an input opening 14. Furthermore, the feed adapter 10 of Fig. 2a comprises, on the output side, an attachment structure 12 that has two webs 18 and defines an output opening 15 at its front end. The input opening 14 and the output opening 15 each have a round cross-section. The attachment structure 12 can comprise a ring that is attached to the hollow cylinder 11 by the webs 18 along the longitudinal axis LA coaxial with the hollow cylinder 11. The ring encompasses or encloses the output opening 15. In the example of Fig. 2a, a protective structure 16 is arranged on the ring.

[0055] Fig. 2b shows an exploded view of the embodiment of the feed adapter 10 from Fig. 2a. Fig. 2b illustrates that the feed adapter 10 from Fig. 2a can be formed in one piece, wherein the protective structure 16 can be detachably arranged on the attachment structure 12.

[0056] The protective structure 16 can be designed as a protective bracket or protective cap and can include a scratch-resistant coating 17. The protective structure 16 is preferably formed from a bent steel part. The scratch-resistant coating is preferably formed by a vulcanized rubber layer. Furthermore, the protective structure 16 can include at least two wings, which serve to attach the protective structure 16 to the attachment structure 12, e.g., on the outside of the webs 18 by clamping and / or clipping. The protective structure 16 is preferably arranged completely around the exit opening 15 on the exit side. The protective structure 16 can reduce or prevent marks on the workpiece, particularly on sensitive surfaces of the workpiece.

[0057] Fig. 2c shows a second embodiment of a feed adapter 10 according to one aspect of the invention. The feed adapter 10 of Fig. 2c differs from that of Fig. 2a in that the exit opening 15 is open on one side, i.e., is no longer completely defined. The attachment structure 12 in Fig. 2c has only a flat web 18, which extends to the exit opening 15, so that a radial half-space 19 is open opposite the web 18. The web 18 forms a radial boundary to one side of the feed adapter, while the opposite side is completely open. The feed adapter of Fig. 2c is therefore also suitable for flow-hole forming screw connections when the workpiece is only accessible from one side or at an angle.

[0058] Fig. 3a shows an embodiment of the feed head 20 according to one aspect of the invention. The feed head 20 of Fig. 3a comprises an axial cavity, which preferably has a round cross-section and opens into an axial opening 21. As shown in Fig. 3a, the axial opening 21 can have a recess 22. The front region of the feed head 20, i.e. the region which directly adjoins the axial opening 21 on the inside, can be designed as a bushing 24. In a feed head 20 from the prior art, this bushing is exposed to the greatest wear, whereas in the feed head according to one aspect of the invention it is protected by the use of a feed adapter. For this purpose, the feed adapter can be received in the bushing 24 in a form-fitting manner. Consequently, the feed head 20 according to one aspect of the invention is more durable and robust than previously known feed heads or hold-down devices.

[0059] Fig. 3b shows a longitudinal section through the embodiment of the feed head 20 from Fig. 3a, in which the position of the bushing 24 is visible. Fig. 3c shows a front view of an embodiment of the feed adapter 10 according to one aspect of the invention. The feed adapter 10 of Fig. 3c has a radial projection 13 on its hollow cylinder 11, which corresponds to the recess 22 of the feed head. The projection 13 can be designed as a contour. As a result, the projection 13 can be at least partially received in the recess 22 when the feed adapter 10 is coupled to the feed head 20. The feed adapter 10 can thus be oriented more easily. Preferably, the projection 13 is arranged at the outlet of the hollow cylinder 11. This prevents unintentional rotation of the feed adapter 10 relative to the feed head 20 and thus increases operational reliability.

[0060] In the front view of Fig. 3c it is also evident that the attachment structure 12 can have a wider cross-sectional area than the hollow cylinder 11, whereby the diameter of the inlet opening 14 along the longitudinal axis LA is not undercut.

[0061] Fig. 4 shows an embodiment of a feed head system according to one aspect of the invention without a mounted feed adapter. The left section of Fig. 4 shows a top view of the feed head system 1. Visible are the installed feed head 20 and a guide clamp that closes off the feed head 20 on the output side.

[0062] The central section of Fig. 4 shows a side view of the feed head system 1. In the side view, the feed head 20 is largely obscured. A guide structure is shown, by means of which a joining agent can be received in the feed head system and provided to the feed head 20. In the example of Fig. 4, this guide structure is two-part and comprises a receptacle, which is preferably vertically aligned and arranged offset from the feed head 20, and a transfer from the receptacle into the feed head 20.

[0063] The right section of Fig. 4 shows a longitudinal section along the AA axis through the feed head system. The longitudinal section shows the bushing 24 at the output of the feed head 20. The receiving and transfer points of the guide structure can also be seen.

[0064] Fig. 5 shows the embodiment of a feed head system from Fig. 4 with a mounted feed adapter. Fig. 5 shows a top view, a side view, and a longitudinal section corresponding to Fig. 4, with the difference that in Fig. 5 the feed adapter 10 is mounted according to one aspect of the invention. In this respect, the hollow cylinder 11 can fill the bushing 24 in a form-fitting manner and thus protect it from high wear. In the embodiment shown in Fig. 5, the feed adapter 10 is mounted without a protective structure 16. In other embodiments, the protective structure 16 can be plugged onto the feed adapter 10 to protect sensitive surfaces of the workpiece.

[0065] Fig. 6a shows a partially exploded view of an embodiment of a feed head system according to one aspect of the invention.

[0066] In the feed head system 1 of Fig. 6a for a joining device, a feed head 20 is arranged, which can be designed, for example, according to the embodiment of Fig. 3a. The axial opening 21 of the feed head 20 is positioned behind a guide clamp of the feed head system 1. The guide clamp can be used to control the contact force applied to the joining material during the joining process.

[0067] As further components of the feed head system 1 of Fig. 6a, the feed adapter 10, for example as shown in Fig. 2a or Fig. 2c, and a clamping means 23, preferably a clamping pin, are shown in an exploded view.

[0068] Fig. 6b shows the feed head system 1 of Fig. 6a in its assembled state. The feed adapter 10 is at least partially positively received in the feed head 20 of the feed head system 1, thereby forming an additional surface or material layer within the wear-prone bushing 24. The attachment structure 12 serves to position the feed head system 1 or the joining agent that is processed by the feed head system 1. The feed adapter 10 can be secured against falling out by means of the clamping device 23.

[0069] The feed adapter 10 allows a user or customer to replace the main wear part directly on-site. This results in significant time savings, reduced downtimes, and, of course, cost savings for the customer's business. Furthermore, CO2 emissions can be reduced by eliminating the need to transport hold-down devices requiring repair. The feed head system solution, comprising a feed head 20 and an exchangeable feed adapter 10, has the additional advantage of allowing for individual and rapid response to customer needs. The basic geometry of the feed head 20 no longer needs to be adapted, but only the feed adapter 10. Any shape of the feed adapter 10, in particular the attachment structure 12, is conceivable.

[0070] List of reference symbols:

[0071] I Feed head system

[0072] 10 feed adapters

[0073] II Hollow cylinder

[0074] 12 Attachment structure

[0075] 13 projection of the hollow cylinder 11

[0076] 14 Entrance opening

[0077] 15 Exit opening

[0078] 16 Protective structure

[0079] 17 Scratch-resistant coating of the protective structure 16

[0080] 18 Web of the attachment structure 12

[0081] 19 radial open half-space

[0082] 20 Feed head

[0083] 21 axial opening of the feed head 20

[0084] 22 Recess at the edge of the axial opening 21

[0085] 23 clamping devices

[0086] 24 socket

[0087] LA longitudinal axis

Claims

Claims 1. Feed adapter (10) for a joining device, in particular a flow drilling device, wherein the feed adapter (10) has an inlet opening (14), an outlet opening (15) and an axial hollow body (11; 12) between the inlet opening (14) and the outlet opening (15), and the inlet opening (14) of the feed adapter (10) can be detachably coupled coaxially to a feed head (20) of the joining device, such that the feed adapter (10) guides a joining agent provided by the feed head (20) to the outlet opening (15) during a joining process within the hollow body (11; 12).

2. The feed adapter (10) according to claim 1, wherein the hollow body (11; 12) is formed at least in sections as a hollow cylinder (11).

3. The feed adapter (10) according to the preceding claim, wherein the hollow body (11; 12) further comprises an attachment structure (12) which is arranged axially on the hollow cylinder (11) and comprises the outlet opening (15), wherein the outlet opening (15) is preferably arranged at a predetermined axial distance from the hollow cylinder (11).

4. The feed adapter according to the preceding claim, wherein the attachment structure (12) has at least one radial opening (18) and / or a half-space (19) open in the radial direction for dissipating heat generated during the joining process.

5. The feed adapter (10) according to one of the preceding claims, further comprising at least one protective structure (16) which is arranged on the output side at the output opening (15) and covers a surface of the attachment structure (12) at least in sections, wherein the protective structure (16) preferably has a scratch-resistant coating (17), in particular a vulcanized rubber coating.

6. The feed adapter (10) according to the preceding claim, wherein the protective structure (16) is detachably arranged on the attachment structure (12).

7. Modular feed head system (1) for a joining device, in particular a flow drilling device, wherein the feed head system (1) comprises: - a feed head (20) adapted to receive a joining agent and provide it for a joining process, and - a feed adapter (10) according to one of the preceding claims, wherein the feed head (20) has an axial opening (21) which is adapted to be at least partially positively coupled to the hollow body (11; 12) of the feed adapter (10), and wherein the feed adapter (10) is detachably coupled to the feed head (20).

8. The modular feed head system (1) according to the preceding claim, wherein the feed adapter (10) is designed according to one of claims 2 to 7, and the feed head (20) is adapted to receive the hollow cylinder (11) of the feed adapter (10) in a completely form-fitting manner, wherein the feed adapter (10) is preferably fastenable to the feed head (20) by means of a clamping means (23).

9. The modular feed head system (1) according to the preceding claim, wherein the hollow cylinder (11) has a radial projection (13), and the axial opening (21) of the feed head (20) has a radial recess (22) corresponding to the projection (13) of the feed adapter (10), wherein, when the feed adapter (10) is coupled to the feed head (20), the projection (13) is at least partially received in the recess (22).

10. Joining device comprising a modular feed head system (1) according to one of claims 7 to 9, a drive and / or pressing means and a control unit, wherein the control unit is adapted to control a joining means by means of the drive and / or pressing means in interaction with the feed head system (1) for carrying out a joining process.

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