Joining tool

Abstract

The invention relates to a joining tool (100) having a hold-down device (110) which is configured for holding and positioning connecting elements, a process-driving mechanism (120) which is configured for screwing connecting elements into two materials to be connected, and a spacer cylinder (130) which is configured for providing and controlling the distance between the hold-down device (110) and the process-driving mechanism (120), the spacer cylinder (130) being free of pneumatics.

Description

[0001] Atlas Copco IAS GmbH, Case: 13N2024PA1069DE

[0002] joining tool

[0003] The present invention relates to a joining tool.

[0004] Technical background

[0005] Joining tools, i.e., mechanical tools with which at least two different elements made of different materials, such as high-strength steel, aluminum, cast iron, magnesium, carbon, or plastics with different strength properties, are joined together, are generally known. A connection can be achieved by gluing, riveting, and / or sewing. Alternatively, a connection between at least two different elements can be achieved by holding and positioning a fastener, in particular a screw, with a hold-down device and rotating it at high speed during a process stroke under pressure, i.e., by pressing it through the materials of the different elements to be joined.The strong rotation of the fastener and the pressing motion of the joining tool cause the materials of the different elements to be joined to melt at specific points, thereby forming a thread in the materials of the elements being joined. Such joining tools are also known as flow drill fastening (FDF) tools.

[0006] In a typical joining tool, particularly a flow drilling device, the hold-down and the process stroke are variably spaced by a pneumatic spacer cylinder. For example, in a home position, the spacer cylinder sets a defined distance between the hold-down and the process stroke. This distance is defined such that the process stroke is stopped by the spacer cylinder precisely when the bit or socket is engaged in the force-applied section of the process stroke. In the subsequent machining process, the fastener is moved through the hold-down, requiring the spacer cylinder to be adjusted so that the process stroke can move relative to the hold-down and the screw can be driven into the component.

[0007] Known joining tools, particularly flow drilling devices that utilize a pneumatic spacer cylinder, have the disadvantage that their effectiveness is highly dependent on the compressed air supplied to the spacer cylinder. Studies have shown that even slight differences or deviations from an ideal compressed air quality can lead to significant negative changes in effectiveness. Furthermore, the additional supply of compressed air to the joining tool, alongside energy or electricity, makes its operation more costly and only justifiable in certain applications. (Atlas Copco IAS GmbH, Case: 13N2024PA1069DE)

[0008] Environments are possible where compressed air is available in addition to electricity. This drastically reduces the possible applications of the joining tools.

[0009] Summary of the invention

[0010] It is an object of the present invention to provide a joining tool, in particular a flow drilling device, which is independent of compressed air, so that a constant or continuous effectiveness or efficiency can be provided, the operation of the joining tools is more cost-effective and the range of applications of the joining tools can be increased.

[0011] 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.

[0012] According to one aspect of the invention, a joining tool is described. The joining tool comprises a hold-down device configured for holding and positioning fasteners, a process stroke configured for screwing fasteners into two materials to be joined, and a spacer cylinder configured for providing and controlling a distance between the hold-down device and the process stroke, wherein the spacer cylinder is free of pneumatics.

[0013] The term "joining tool" here refers to any continuous drilling device in which a fastener, particularly a screw, is held and positioned by a hold-down device and rotated at high speed by a process stroke, pressing it through the materials of the elements to be joined. The high rotation of the fastener and the pressing motion of the joining tool cause localized melting of the materials of the elements to be joined, forming a thread. A joining tool can comprise a hold-down device, a process stroke, and a spacer cylinder. A microelectromechatronic system (MEMS) can be integrated into the components of the joining tool, i.e., the hold-down device, the process stroke, and / or the spacer cylinder.

[0014] The term "hold-down device" represents any device configured to hold and / or position fasteners, connecting two materials to be joined using the fastener. The hold-down device may be mounted on a slide, which is arranged on a rail, allowing the hold-down device to be extended and retracted. The hold-down device is spaced from the process stroke by a spacer cylinder.

[0015] The term "process stroke" refers to any element of the joining tool that rotates a fastener within the hold-down device at high speed and presses it through the materials of the various elements to be joined. The process stroke can be a screw tool with a motor and a shaft, connected to the motor on one side and to a fastener on the other. The process stroke, particularly the shaft of the screw tool, can extend into the hold-down device. The process stroke can be mounted on a slide that moves along a rail, allowing it to move relative to the hold-down device. Alternatively, the process stroke can be directly coupled or connected to the spacer cylinder, with a piston-like structure within the spacer cylinder adjusting the distance between the process stroke and the hold-down device.

[0016] The term "spacer cylinder" refers to any element that provides a distance between the hold-down device and the process stroke. The spacer cylinder can be positioned precisely between the process stroke and the hold-down device and / or can be directly coupled or connected to the hold-down device and / or the process stroke. For example, the spacer cylinder can incorporate an electric motor, particularly a hollow-shaft motor, and a ball screw.

[0017] Alternatively, the spacer cylinder can incorporate a moving-coil motor. The moving-coil motor has a permanent magnet housed in a casing and a coil inserted into a space between the permanent magnet and the casing. 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 moving-coil motor to form a spacer cylinder.

[0018] Alternatively, the spacer cylinder can be designed as a piston system filled with a rheological fluid. The piston system is coupled or connected to a compensating cylinder, which is pre-tensioned by a spring, so that the rheological fluid can escape into the spring-loaded compensating cylinder.

[0019] The transfer channel, through which the rheological fluid flows from the piston system into the compensating cylinder, can be subjected to a magnetic field, causing the rheological fluid to solidify and the spacer cylinder to become blocked. Atlas Copco IAS GmbH, Case: 13N2024PA1069DE

[0020] The distance cylinder can be directly coupled or connected to the process stroke. The distance cylinder can include a control unit for controlling motors, e.g., electric motors or voice coil motors, which are integrated into the process stroke or the hold-down device.

[0021] The term "free from pneumatics" describes the fact that the spacer cylinder is not a pneumatic spacer cylinder. In other words, the spacer cylinder does not use pneumatics or air pressure. Instead, the extension and retraction of the spacer cylinder, in particular a piston-like structure of the spacer cylinder, is achieved through a method other than pneumatics.

[0022] By replacing the pneumatic spacer cylinder with a pneumatic-free spacer cylinder, a joining tool, in particular a flow drilling device, can be provided that is independent of compressed air, so that a constant or continuous effectiveness or efficiency can be provided, the operation of the joining tools is more cost-effective and the application possibilities of the joining tools can be increased.

[0023] According to one embodiment of the invention, the distance cylinder has an electric motor and a ball screw.

[0024] The use of an electric motor with a ball screw has the advantage that a spacer cylinder can be provided without pneumatics and that the spacer cylinder can be designed with a significantly smaller installation space. This allows the entire joining tool to be designed more compactly.

[0025] According to one embodiment of the invention, the distance cylinder has a moving coil motor.

[0026] Using a voice coil motor as a spacer cylinder offers the advantage of eliminating the need for pneumatics. Furthermore, it is more energy-efficient, and the cylinder can be moved, extended, and retracted more quickly and precisely. The voice coil drive can also be integrated directly into the supporting structure of the process stroke, resulting in improved energy efficiency and a more compact design. Additionally, the voice coil motor's control unit can detect the coil's position and thus the distance between the process stroke and the hold-down device, eliminating the need for separate position sensors. The unit also monitors the speed of movement and the power required to generate that movement. (Atlas Copco IAS GmbH, Case: 13N2024PA1069DE)This provides information about the condition of the joining tool, which is used for maintenance purposes.

[0027] According to one embodiment of the invention, the spacer cylinder has a piston system with a rheological fluid.

[0028] The use of a piston system with a rheological fluid has the advantage that a spacer cylinder can be provided without pneumatics and that the spacer cylinder can be designed with a significantly smaller installation space. This allows the entire joining tool to be designed more compactly.

[0029] Brief description of the characters

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

[0031] Fig. 1 shows a joining tool with an extended spacer cylinder, as known in the prior art.

[0032] Fig. 2 shows a joining tool with a retracted spacer cylinder, as known in the prior art.

[0033] Fig. 3 shows a first spacer cylinder according to the invention.

[0034] Fig. 4 shows a second spacer cylinder according to the invention.

[0035] Fig. 5 shows a third spacer cylinder according to the invention.

[0036] Detailed description

[0037] Fig. 1 shows a joining tool according to the invention with an extended spacer cylinder, as known in the prior art. The joining tool 100 has a hold-down device 110, a process stroke 120, and a spacer cylinder 130. The hold-down device 110 is configured for holding and positioning fasteners. The process stroke 120 is configured for screwing fasteners into two materials to be joined. The spacer cylinder 130 is configured for providing and controlling a distance between the hold-down device 110 and the process stroke 120. The spacer cylinder 130 is pneumatically operated. The joining tool 100 in Fig. 1 is shown in a starting position. In this position, the hold-down device 110, which is arranged on a slide, is retracted. The process stroke 120, which is also arranged on a slide and can move relative to the hold-down device 110, is positioned in a central position of the joining tool 100.The distance cylinder 130 is extended.

[0038] Fig. 2 shows a joining tool with a retracted spacer cylinder, as known in the prior art. The hold-down device 110, arranged on a slide, is extended (see arrows). Atlas Copco IAS GmbH, Case: 13N2024PA1069DE

[0039] The process stroke 120, which is mounted on a slide, is also extended. The distance cylinder 130 is retracted.

[0040] Fig. 3 shows a first spacer cylinder according to the invention. The spacer cylinder 130 comprises an electric motor 131a and a ball screw 132a. The electric motor 131a is directly coupled to / connected to the ball screw 132a, so that the motor 131a drives the ball screw 132a.

[0041] Fig. 4 shows a second distance cylinder according to the invention. The distance cylinder 130 comprises a moving-coil motor. The moving-coil motor has a permanent magnet 132b arranged in a housing 133b and a coil 131b which is inserted into a space 134b between the permanent magnet 132b and the housing 133b. By means of the permanent magnet and the magnetic field induced in the coil 131b, the coil 131b can be extended and retracted into the space 134b, whereby the moving-coil motor forms a distance cylinder 130.

[0042] Fig. 5 shows a third spacer cylinder according to the invention. The spacer cylinder 130 comprises a piston system, in particular a cylinder 132c with a piston 131c, which is filled with a rheological fluid 138c. The piston system is connected or coupled to a compensating cylinder 135c, the compensating cylinder being preloaded by means of a preloading system consisting of a preloading element 134c and a spring 133c. This allows the rheological fluid 138c to escape into the spring-preloaded compensating cylinder 135c through a transfer channel 136c. The transfer channel 136c, through which the rheological fluid flows from the piston system into the compensating cylinder 135c, can be subjected to a magnetic field by means of a magnetic field generation device 137c, e.g., a coil. By applying / providing a magnetic field to the overflow channel 136c, the rheological fluid solidifies and the spacer cylinder 130 is blocked.

Claims

Atlas Copco IAS GmbH, Case: 13N2024PA1069DE Claims 1. Joining tool (100) comprising: a hold-down (110) configured for holding and positioning fasteners; a process stroke (120) configured for screwing fasteners into two materials to be joined; and a spacer cylinder (130) configured for providing and controlling a distance between the hold-down (110) and the process stroke (120), wherein the spacer cylinder (130) is free of pneumatics.

2. Joining tool (100) according to claim 1, wherein the spacer cylinder (130) comprises an electric motor (131a) and a ball screw (132a).

3. Joining tool (100) according to claim 1, wherein the distance cylinder (130) has a moving coil motor.

4. Joining tool (100) according to claim 1, wherein the spacer cylinder (130) comprises a piston system with a rheological fluid.

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