Two-Stage Gravity Press for Automotive Glass Shaping
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Solution Overview
Problem
Current glass manufacturing processes for vehicle windshields often result in optical and reflective distortions due to stress-induced buckling, leading to unacceptable surface quality and dimensional inaccuracies, especially in high-performance vehicles with advanced braking and suspension systems that rely on clear camera views through the windshield.
Innovation Solution
A multistage press system is used to clamp the glass perimeter and shape the center section, employing a lower and upper press ring with a vacuum-forming process to minimize stress and distortion, allowing for precise control over the glass shape and surface fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If glass is pressed into shape by pushing from the outside perimeter, then the glass can be formed into curved shapes, but stresses are created that cause localized buckling and optical distortion
Solution Approach 1:
The patent inverts the conventional pressing approach by supporting the glass from the perimeter and allowing it to sag under its own weight into the desired shape, rather than pushing from the perimeter. This reversal of the force application method eliminates the compressive stresses that cause buckling while achieving the required curved shape.
Solution Approach 2:
The patent uses the glass's own weight as a counterforce to the pressing force. By supporting the perimeter and allowing gravitational force to act on the glass, the natural sagging motion counteracts the tendency for stress-induced buckling that occurs with conventional pressing methods.
2Shape
If glass is pressed into shape with conventional techniques, then the glass can be formed, but wrinkles and buckles occur causing optical distortions
Solution Approach 1:
The patent inverts the conventional pressing approach by supporting the glass from the perimeter and allowing it to sag under its own weight into the desired shape, rather than pushing from the perimeter. This reversal of the force application method eliminates the compressive stresses that cause buckling while achieving the required curved shape.
Solution Approach 2:
The patent replaces the mechanical pressing system with a gravitational system. Instead of using mechanical force to push the glass into shape, the invention uses gravitational force acting on the supported glass, eliminating the mechanical stresses that cause wrinkles and buckles.
3Manufacturing precision
If counter forces are applied to alleviate wrinkles and buckles, then some distortion can be reduced, but the process becomes more complex and produces unpredictable results
Solution Approach 1:
The patent applies preliminary action by supporting the glass perimeter before the forming process begins. This preliminary support structure prevents the development of wrinkles and buckles in the first place, eliminating the need for subsequent corrective counter-forces and simplifying the overall process.
Solution Approach 2:
The patent converts the potentially harmful effect of gravity (which causes sagging) into a beneficial force that naturally forms the glass into the desired shape without creating stress-induced buckles. The glass's own weight, which could be harmful, becomes the forming mechanism that ensures surface quality.
4Shape
If glass is allowed to bend during the forming process, then the glass can be shaped, but the time required increases and breakage rates increase
Solution Approach 1:
The patent uses the glass's own weight as a counterforce to the pressing force. By supporting the perimeter and allowing gravitational force to act on the glass, the natural sagging motion counteracts the tendency for stress-induced buckling that occurs with conventional pressing methods.
Solution Approach 2:
The patent replaces the mechanical pressing system with a gravitational system. Instead of using mechanical force to push the glass into shape, the invention uses gravitational force acting on the supported glass, eliminating the mechanical stresses that cause wrinkles and buckles.
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 approach reduces compressive stress, minimizes buckling, and enhances the optical clarity and dimensional accuracy of glass panels, improving the manufacturing process efficiency and reducing breakage rates while meeting the stringent requirements of high-performance vehicle systems.
Implementation Method 1
employing a lower and upper press ring with a vacuum-forming process to minimize stress and distortion
Data Source
AI summary
Apparatus for shaping at least one glass sheet wherein a lower press ring and an upper press ring are configured to clamp a perimeter section of the glass sheet between the lower press ring and the upper press ring. The apparatus also includes an inner press at least partially disposed within the upper press ring and configured to shape at least a section of the glass sheet inside the perimeter section of the glass sheet. The inner press is fixed to a top plate and is moveable within limits with respect to the upper press ring. When a suspension assembly and the top plate are lowered, a carrying frame limits the descending movement of the upper press ring so that the inner press descends under gravity force until the upper press ring contacts the carrying frame and the suspension assembly decouples from the top plate. The inner press continues to move downwardly under gravity force to shape the center part of the ply until the top plate contacts the upper press ring. To unclamp the ply, the suspension assembly is vertically raised to cause the suspension assembly to re-couple with the top plate and move the inner press upwardly until the suspension assembly lifts the upper press ring together with the inner press.