Rivet Element Fastening With Spacer-Controlled Gap Formation
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Solution Overview
Problem
The existing method for attaching a riveting element to a workpiece with a preformed hole requires a separate preprocessing step for deforming the workpiece, which is inconvenient and can lead to unwanted deformations, especially when dealing with differently dimensioned rivet elements and workpieces.
Innovation Solution
A method that uses a movable and/or elastically formed spacer to maintain a well-defined distance between the workpiece and the die, creating a gap for the rivet section to engage, allowing for precise control and adaptation of the gap width, eliminating the need for preprocessing and minimizing workpiece deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the workpiece is deformed in a bead-like manner to create a gap for rivet section engagement, then the rivet connection reliability is improved, but the device complexity and process time increase due to requiring a separate pre-processing step
Solution Approach 1:
The spacer is pre-positioned on the die before the riveting process begins. This preliminary placement of the spacer creates the necessary gap between the workpiece and die without requiring separate bead-forming operations, thereby improving reliability while avoiding additional process steps
Solution Approach 2:
The spacer acts as an intermediary element between the die and the workpiece. It mediates the gap creation function, allowing the rivet section to engage properly without requiring complex workpiece deformation or additional processing equipment
2Strength
If the workpiece is deformed to form a bead for rivet engagement, then the rivet connection strength is improved, but the manufacturing precision decreases due to disruptive deformation that must be adapted to different rivet dimensions
Solution Approach 1:
Instead of changing the workpiece geometry through deformation, the spacer's position and dimensions are adjusted to control the gap parameters. This allows adaptation to different rivet dimensions without deforming the workpiece, maintaining manufacturing precision while ensuring proper rivet engagement
3Manufacturing precision
If a separate pre-processing step is added to deform the workpiece, then the productivity decreases, but the manufacturing precision improves by ensuring proper gap formation
Solution Approach 1:
The gap formation function is merged into the main riveting process by pre-positioning the spacer on the die. This eliminates the need for separate bead-forming operations, maintaining precise gap control while improving productivity by combining functions into a single process step
4Ease of operation
If the workpiece remains flat without bead deformation, then the ease of operation improves, but the reliability of rivet engagement decreases without sufficient gap space
Solution Approach 1:
The spacer serves as a mediator that creates the necessary engagement gap without requiring workpiece deformation. This allows the workpiece to remain flat and easy to handle while ensuring reliable rivet engagement through the spacer-controlled gap
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables reliable and efficient attachment of riveting elements without additional preprocessing steps, ensuring a secure connection while minimizing workpiece deformation, and is suitable for various dimensions of rivet elements and workpieces.
Implementation Method 1
at least one movable and/or elastically designed spacer of a die for forming the rivet section
Implementation Method 2
the rivet section is introduced into the gap during the fastening process and is formed by the punch in order to engage behind the workpiece
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a method for fastening a rivet element (10) to a workpiece, in particular to a sheet metal part (12), which has a preformed hole (26) intended to accommodate a rivet section (32) of the rivet element (10) and which at least in Area around the preformed hole (26) is flat. Before the fastening process, the workpiece (12) is placed at a well-defined distance (D) from a contact surface (18) of the die ( 14) so that a gap (30) is formed between a wall (28) of the hole (26) and a punch (24) of the die provided for forming the rivet section. The rivet section (32) is introduced into the gap (30) in the course of the fastening process and is shaped by the punch (24) in order to engage behind the workpiece (12) in the region of the hole (26).