Sleeve Printer Printhead Protection via Mechanical Test Strip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing printing machines face reliability issues due to geometric deviations on sleeve-shaped workpieces, such as bulges or dirt particles, which can damage print heads during the printing process, especially when using ink jet print heads at close distances.
Innovation Solution
A sensor device and test strip system is integrated into the printing machine, allowing for real-time detection of geometric deviations. The sensor device outputs an error signal if deviations exceed a predetermined tolerance, triggering adjustments to maintain a safe distance between the print head and workpiece, preventing potential damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the print head is positioned at a small distance from the workpiece surface to improve printing precision, then manufacturing precision is improved, but the risk of damage from geometric deviations increases
Solution Approach 1:
The test strip performs a preliminary scan of the workpiece surface before the printhead approaches. This advance detection allows the system to identify geometric deviations (bulges, dirt particles) beforehand and adjust the printhead distance or skip problematic areas, preventing damage while maintaining close-distance printing precision where safe
Solution Approach 2:
The test strip acts as an intermediary between the workpiece surface and the printhead. It physically contacts the workpiece surface first to detect deviations, serving as a protective mediator that prevents direct contact between the printhead and potentially damaging surface irregularities
2Measurement precision
If optical scanning is used to detect surface geometry deviations, then measurement capability is improved, but device complexity and data processing requirements increase
Solution Approach 1:
The test strip is a simple, inexpensive mechanical element that can be easily replaced. Instead of using complex optical sensors and extensive data processing systems, the invention employs a straightforward mechanical test strip that physically contacts the surface, providing sufficient detection capability with minimal complexity
Solution Approach 2:
The invention replaces complex optical-mechanical sensor systems with a simpler pure mechanical test strip system. The test strip's physical contact and deflection provide direct mechanical measurement of surface deviations, eliminating the need for complex optical scanning and digital data processing
3Measurement precision
If the test strip is rigidly mounted to maximize detection accuracy, then measurement precision is improved, but the risk of collision damage increases
Solution Approach 1:
The test strip is mounted with pivoting capability rather than rigid fixation. This dynamic mounting allows the test strip to deflect and pivot when encountering geometric deviations, maintaining detection accuracy through controlled movement while preventing rigid collisions that could damage the workpiece or test strip
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a printing machine for printing on sleeve-shaped workpieces (6), with a machine frame on which a conveying device (3) with several workpiece holders (4) is arranged, which are rotatably mounted on the conveying device (3), with drive means for the conveying device (3) and the workpiece holders (4) and with at least one printing device (20) which is arranged along a movement path (23) and which comprises at least one printhead (21) with a series arrangement of ink metering elements, each designed for an individually predefinable application of ink to the workpiece (6), wherein the printhead (21) is assigned an electrically controllable adjusting device (35) for adjusting a relative position to the workpiece (6).According to the invention, a scanning device (40) for surface scanning of the workpieces (6) is arranged along the path of movement (23), comprising a test bar (41) movably mounted on the machine frame and a sensor device (58) for detecting a position and/or relative movement of the test bar (41) relative to the machine frame.