Devices for mounting self drilling metal screws

Abstract

Purpose. Design, manufacture and test the assembly tools for the self-drilling screws. Devices meet the requirements of hard location the screw, based on the outer diameter of the thread, the inner diameter of the thread or jig bushing, while at the end of the screwing, holding elements pass the head of the screw. Design/methodology/approach. In a paper it is shown that thread-forming screws, known as self-tapping screws capable of forming or rolling a matching thread into the material into which they are installed requires a hard location of the screw in device to prevent action the radial component of the cutting force. And at the same time devices, that meet the requirements of hard location the screw in the locator, at the end of the screwing let the screw head through them. The presented devices hold the screws for the outer diameter of the thread, the inner diameter of the thread or jig bushing. A device designed to align hex parts, such as screw heads, is also described. Such devices are designed for automated production. Findings. The developed devices were manufactured and tested. Self-drilling screws drilled holes under the action of axial load, maintaining the correct position and with a free passage of the screw head at the end of drilling. Two of the devices presented are protected by copyright. Originality/value. In the presented devices assembly with the use of self-drilling forming screws consists in the sequential execution of two diverse operations - first drilling, and then rolling the thread under the action of axial load. In this case, the device rigidly bases the screw, but let the screw head pas sat at the end of drilling. Developed devices can be used in assembly automation

Keywords

• SR screws (self-drilling thread screws)
• self-drilling forming screw
• screw connections
• assembly automation