Feed head device and joining device

Abstract

According to a first aspect of the invention, a feed head device for holding, guiding and / or positioning a fastening element in a joining device is provided. The feed head device comprises a holding device which is designed to hold and / or guide a fastening element in a first position and to open in a second position. The feed head device also comprises a feed unit which is designed to move the holding device between the first position and the second position, the feed unit being operable without compressed air.

Description

[0001] Atlas Copco IAS GmbH, Case: 13N2024PA1068DE

[0002] Feeding head device and joining device

[0003] The present invention relates to a feed head device for holding, guiding and / or positioning a fastening element in a joining device and a corresponding joining device comprising the feed head device.

[0004] Technical background

[0005] Car body designs are becoming increasingly sophisticated in order to reduce carbon monoxide emissions and improve crash safety. This leads to more complex manufacturing processes. Multiple materials with varying strength properties must be joined, 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 a challenge.

[0006] Flow-drill fastening (FDF) is a solution to these challenges. This technology offers multi-material connections with single-sided access, using a single fastener as both the drill and the fastener. The fastener is rotated at high speed and under pressure to heat the material. This allows the fastener to be forced through the material stack, forming a thread – an efficient and flexible fastening method. Appropriate FDF system solutions ensure precise operation of the fastening process in harsh production environments.

[0007] In flow drilling, the fasteners must be held in a defined position relative to the component surface within the nozzle of the joining device. According to current technology, this is achieved using so-called retaining pawls. Due to the high rotational speeds reached during flow drilling, these retaining pawls are subject to significant wear. Therefore, current technology maintains the holding and guiding function only as long as absolutely necessary for the joining process. Depending on the progress of the joining process, the holding and guiding function is released. This is achieved, for example, by a mechanical release or by pneumatically opening the retaining pawls.

[0008] One disadvantage of the mechanical release is that the retaining pawls remain in contact with the rapidly rotating fastener after release. While this significantly reduces wear, it cannot eliminate it entirely. (At an active Atlas Copco IAS GmbH, Case: 13N2024PA1068DE)

[0009] Opening the latches with a pneumatic drive can significantly reduce wear on the retaining latches. However, using a pneumatic actuator to open the retaining latches is not efficient, as compressed air is an expensive and environmentally harmful form of energy.

[0010] Furthermore, the dependence on compressed air limits the operation of the joining device to environments where compressed air can be supplied in addition to electricity. This severely reduces the possible applications of the joining device.

[0011] Summary

[0012] It is therefore an object of the present invention to provide a feed head device for a joining device which is independent of compressed air, so that a consistent or continuous effectiveness or efficiency can be provided, the operation of the joining device is more cost-effective and the applicability of the joining device can be increased. It is a further object of the invention to provide a corresponding joining device.

[0013] At least one of the problems, or further problems, that arise for a person skilled in the art from the present disclosure are solved by the subject matter of the independent claim. Advantageous embodiments are the subject matter of the dependent claims and the description.

[0014] According to a first aspect of the invention, a feed head device is provided for holding, guiding, and / or positioning a fastener in a joining device. The feed head device comprises a holding device configured to hold and / or guide a fastener in a first position and to open it in a second position. The feed head device further comprises a feed unit configured to move the holding device between the first position and the second position, wherein the feed unit can be driven or controlled without compressed air.

[0015] The term "holding device" represents any device configured to hold and / or guide a fastener. The holding device can be activated, i.e., opened, by the feed unit, i.e., by moving forward. In the second position, the holding device can no longer hold or guide the fastener, as it is no longer in contact with it. Atlas Copco IAS GmbH, Case: 13N2024PA1068DE

[0016] In one embodiment, the feed unit can be electrically driven. For this purpose, the feed unit can comprise an electric motor and a ball screw. Alternatively, the feed unit can comprise a hollow shaft motor with an integrated ball screw.

[0017] The use of an electric motor or a hollow shaft motor with a ball screw offers the advantage of providing a feed unit that can be controlled without pneumatics and that the feed unit can be designed with a significantly smaller installation space. This allows the feeding head device or the joining device to be designed considerably more compactly.

[0018] In a further embodiment, the feed unit can include a voice coil motor. The voice coil motor has a permanent magnet arranged in a housing and a coil that is inserted into a space between the permanent magnet and the housing. The permanent magnet and the magnetic field induced in the coil allow the coil to be extended and retracted from this space, thus enabling the voice coil motor to function as a feed unit.

[0019] The moving coil motor / drive is very energy-efficient and allows for fast, precise movements. Pneumatic valves are no longer required. A control unit for the moving coil motor can be integrated into the feed head device. The control unit detects the position of the coil and thus the position of the holding device. Additional sensors for detecting the end positions of the holding device are therefore unnecessary.

[0020] Furthermore, the speed of movement of the feed unit and the power required to generate that movement can be recorded. This provides information about the unit's condition, enabling predictive maintenance of the holding device.

[0021] In one embodiment, the holding device can have two pivotable latches that touch each other in a first position and are separated from each other by pivoting in a second position.

[0022] The latches serve to laterally stabilize the fastener or screw, particularly during the advance of the screw from a ready position in the Z-direction or towards the workpiece. In a preferred embodiment, the joining device or feed head device also includes a hold-down device at a front end facing the workpiece. This hold-down device can be placed on the workpiece and surrounds the screw to be inserted. The hold-down device can be configured to position the fastener on the workpiece or component surface. For this purpose, the hold-down device can have a projection structure designed to make direct contact with the component surface during the joining process.

[0023] According to a further aspect of the invention, a joining device is provided for carrying out a joining process. The joining device comprises a feed head device as described above, a process stroke configured for screwing a fastener into a component surface, and a spacer cylinder configured for providing and controlling a distance between the feed head device and the process stroke.

[0024] In other words, the joining device can comprise a feed head device as described above, a drive and / or pressure means and a control unit, wherein the control unit is adapted to control a joining element or fastening element by means of the drive and / or pressure means in conjunction with the feed head device to carry out a joining process.

[0025] In this context, a joining device is understood to be, in particular, a flow drilling device in which a fastening element or joining element, especially a flow-drilling screw, is held, positioned, and guided by a feed head device, rotated at high speed by a process stroke, and pressed through a component surface. The rapid rotation of the fastening element and the pressing motion of the process stroke can melt the component surface at specific points, allowing a thread to form in the workpiece. A joining device can comprise a feed head device, a process stroke, and a spacer cylinder. A microelectromechatronic system (MEMS) can be integrated into the components of the joining device, i.e., the feed head device, the process stroke, and / or the spacer cylinder.

[0026] The moving-coil drive can be integrated directly into a supporting structure of the joining device, which, in addition to improved energy efficiency, also enables a more compact design. A unit for controlling the moving-coil motor can be integrated into the process stroke of the joining device.

[0027] The feed head device can be mounted on a slide, which is itself mounted on a rail, allowing the feed head device to be retracted and extended. The feed head device is spaced from the process stroke by a spacer cylinder. Atlas Copco IAS GmbH, Case: 13N2024PA1068DE

[0028] The process stroke can be mounted on a separate slide that moves along a rail, allowing the process stroke to move relative to the hold-down device. The process stroke can be directly coupled or connected to the spacer cylinder, so that a piston-like structure within the spacer cylinder can adjust the distance between the process stroke and the hold-down device.

[0029] Brief description of the characters

[0030] Embodiments of the present disclosure are described in detail below with reference to two figures.

[0031] Fig. 1 shows a schematic side view through a feed head device according to one aspect of the invention.

[0032] Fig. 2 shows a feed unit according to one aspect of the invention.

[0033] Detailed description of the characters

[0034] Fig. 1 shows a schematic side view through a feed head device 1 according to one aspect of the invention.

[0035] In the schematic side view of Fig. 1, the holding device 10 is visible at one end of the feed head device 1 facing the workpiece (not shown). The feed unit 20, however, is hidden in the representation of Fig. 1. For an embodiment of the feed unit 20, reference is made to Fig. 2.

[0036] The holding device 10 is designed as a latch system in Fig. 1. In the side view, one of the two latches of the latch system is visible. In Fig. 1, the holding device is in its first position, in which it is configured to hold and / or guide a (flow-drilling) screw. By moving forward, the holding device 10 can be activated, i.e., moved or pivoted into its second position (not shown). In the second position, the holding device 10 is open to release the screw. By releasing the screw, which is set into rapid rotation, in a timely manner, wear on the holding device 10 can be reduced. At the end of a joining process, the feed unit 20 can move or pivot the holding device 10 back into the first position so that the holding device 10 can hold and / or guide another screw.

[0037] Fig. 2 shows a feed unit 20 according to one aspect of the invention. The feed unit 20 comprises a moving-coil motor. The moving-coil motor has a permanent magnet 22b arranged in a housing 23b and a coil 21b which is inserted into a space 24b between the permanent magnet 22b and the housing 23b. By means of the permanent magnet and the magnetic field induced in the coil 21b, the coil 21b can be moved in and out of the space 24b, whereby the moving-coil motor forms a feed unit 20. The feed unit 20 is free of compressed air.

Claims

Atlas Copco IAS GmbH, Case: 13N2024PA1068DE Patent claims 1. Feeding head device (1) for holding, guiding and / or positioning a fastening element in a joining device, the feeding head device (1) comprising a holding device (10) configured to hold and / or guide a fastening element in a first position and to open it in a second position, and a feed unit (20) configured to move the holding device between the first position and the second position, wherein the feed unit is capable of being driven without compressed air.

2. Feed head device according to claim 1, wherein the feed unit comprises an electric motor and a ball screw; or a moving coil motor.

3. Feed head device according to claim 1 or 2, wherein the holding device (10) has two pivotable latches which touch each other in a first position and are spaced apart from each other by pivoting in a second position.

4. Joining device comprising: a feed head device (1) according to one of the preceding claims, a process stroke configured for screwing a fastening element into a component surface, and a spacer cylinder configured for providing and controlling a distance between the feed head device (1) and the process stroke.

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