Extruder Screw Straightening With Guided Core Runout Measurement
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Solution Overview
Problem
Existing straightening systems for extruder screws struggle to accurately measure and correct concentricity errors, particularly in the core area, due to collision issues with the helix and limitations in measuring technology, leading to incomplete and inaccurate assessments of core runout.
Innovation Solution
A straightening press with a movable measuring head along a guide rail, equipped with control means to maintain a fixed distance from the helix during rotation, and additional measuring devices for non-contact or contact distance measurements, allowing for precise detection of both core and outer diameter concentricity errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotating beam is used to scan the surface of the screw helix, then the measuring lever avoids collision with the helix, but the core surface cannot be measured and the lever must be replaced for different pitches
Solution Approach 1:
The patent replaces the mechanical rotating beam measuring system with a non-contact optical measuring system (laser scanner or camera) that can capture the core surface geometry without physical contact. This eliminates the collision problem while enabling direct core measurement, resolving the contradiction between reliability and measurement precision.
Solution Approach 2:
The patent introduces a non-contact optical field as an intermediary between the measuring system and the workpiece. This optical intermediary allows measurement of the core surface without mechanical contact, avoiding helix collision while maintaining measurement accuracy, and eliminates the need for lever replacement.
2Reliability
If the measuring probe position is shifted during measurement to avoid collision with the helix, then the dial gauge is protected from damage, but considerable operator skill or a complex adjustment mechanism is required
Solution Approach 1:
The patent replaces the mechanical probe shifting mechanism with a non-contact optical measuring system. The optical system naturally avoids collision with the helix by measuring through light fields, eliminating the need for complex adjustment mechanisms or skilled operator intervention while protecting the measuring instrument.
Solution Approach 2:
The optical measuring system automatically adapts to the workpiece geometry without requiring manual adjustment. The system self-adjusts by capturing images or laser scans from fixed positions, eliminating the need for operator skill or complex mechanisms while ensuring instrument protection.
3Device complexity
If automated straightening systems measure only the outer diameter of the helix, then the measurement process is simplified, but core runout errors cannot be accurately detected
Solution Approach 1:
The patent uses non-contact optical measurement to directly capture the core surface geometry, enabling accurate core runout measurement without the complexity of mechanical probe systems. The optical system can measure both outer diameter and core dimensions simultaneously, resolving the contradiction between simplicity and accuracy.
Solution Approach 2:
The patent transitions from one-dimensional mechanical probe measurements to three-dimensional optical field measurements. This dimensional change enables simultaneous measurement of multiple surfaces (core and outer diameter) without increasing mechanical complexity, achieving comprehensive measurement accuracy.
4Adaptability or versatility
If manual straightening processes are used for small batches, then flexibility is maintained, but productivity is low and documented manufacturing processes are difficult to implement
Solution Approach 1:
The patent designs an automated system with universal measurement capabilities that can handle various screw types and pitches through software configuration rather than physical reconfiguration. This maintains flexibility for small batches while achieving high productivity through automation, enabling documented manufacturing processes.
Solution Approach 2:
The patent uses programmable parameters in the automated system to adapt to different workpieces. By changing software parameters rather than physical components, the system maintains flexibility for small batch production while achieving high throughput through automated operation and documentation capabilities.
Data Source
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AI summary
The invention relates to a straightening press (20) for straightening concentricity or straightness errors in elongated work pieces, comprising centring means (21A, 21B) and a work piece (1) clamped between the centring means and having at least one coil region (W1, W2, W3) defining at least one core diameter (Di) and at least one outer diameter (Da) of the work piece and with a coil (2), such as a screw conveyor, in particular an extruder screw. The straightening press also comprises at least one measuring head detecting concentricity errors of the work piece (1). According to the invention, in order to eliminate concentricity errors in extruder coils and other elongated work pieces provided with outer coils, a guide rail (30) arranged approximately parallel to the axis of the work piece (1) clamped between the centring points (21A, 21B) is provided, and the at least one measuring head (10) has means (32; 32A, 32B) for the movement thereof along the guide rail (30), and the at least one measuring head (10) and/or the moving means (32; 32A, 32B) thereof has at least one control means (40; 40A, 40B) configured for maintaining a fixed distance (x) between the coil (2) and the measuring point on the work piece core (1A) during the rotation thereof.