Riveting Tool Stroke Limiting Element for Blind Rivet Repeatability
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Solution Overview
Problem
Conventional riveting tools for setting blind rivet nuts and screws face challenges in achieving consistent and repeatable setting operations due to pressure-controlled or force-controlled settings, which can result in varying quality when manually interrupted by the operator.
Innovation Solution
A riveting tool with an adjusting unit featuring a stroke limiting element that can be adjusted axially to mechanically determine the setting stroke, eliminating the need for drive unit adjustments, allowing for precise and repeatable setting of blind rivet nuts or screws.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure-controlled or force-controlled setting is used, then the setting process can be completed, but the quality varies when manually interrupted by the operator
Solution Approach 1:
The patent replaces the pressure-controlled or force-controlled setting mechanism with a stroke-controlled mechanical system. A stroke limiting element mechanically determines the mandrel travel distance, ensuring consistent rivet deformation regardless of operator intervention. This substitution of control method eliminates variability introduced by manual pressure application.
Solution Approach 2:
The patent changes the control parameter from pressure/force to stroke length. By controlling the mandrel stroke distance through the adjustable stroke limiting element, the system achieves reliable and repeatable rivet setting. The stroke length becomes the primary control parameter, replacing the previously used pressure or force parameters that were susceptible to operator variability.
2Manufacturing precision
If the drive unit is modified to control stroke, then setting repeatability improves, but device complexity increases
Solution Approach 1:
The patent segments the riveting tool into distinct functional modules: a fixed drive unit and a separate adjustable stroke limiting element. This segmentation allows the stroke control function to be added without modifying the core drive unit, maintaining its simplicity while achieving precise stroke repeatability through the independent stroke limiting component.
Solution Approach 2:
The stroke limiting element acts as an intermediary between the drive unit and the mandrel. It mechanically limits the stroke without requiring modifications to the drive unit itself, serving as a mediator that translates the drive unit's motion into a precisely controlled, repeatable stroke while keeping the drive unit unchanged and simple.
3Manufacturing precision
If a separate stop component is added, then stroke control is achieved, but device complexity increases
Solution Approach 1:
The patent merges the stop function with the existing coupling element that connects the mandrel to the drawbar. The coupling element is designed with an integrated stop surface that works with the stroke limiting element, eliminating the need for a separate stop component. This merging reduces the total number of parts while achieving precise stroke control.
Solution Approach 2:
The coupling element serves multiple functions: it connects the mandrel to the drawbar and simultaneously provides a stop surface for stroke limitation. This multi-functionality eliminates the need for dedicated separate components, reducing device complexity while maintaining precise stroke determination capability.
Data Source
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AI summary
The invention relates to a riveting tool for setting blind rivet nuts and/or blind rivet screws, comprising a drive piston hydraulically adjustable from a starting position towards an end position, a pull rod detachably connected to the drive piston and adjustable by the drive piston from a rivet receiving position to a setting position, and a coupling element that connects the pull rod and a draw mandrel in the longitudinal direction. To provide a riveting tool of the type mentioned above, with which consistent rivet setting operations can be carried out with high repeatability, the riveting tool includes an adjusting unit for determining the setting position, with a stroke limiting element that is axially adjustable relative to the coupling element in the longitudinal direction of the pull rod and engages with a stop surface on the coupling element in the setting position.