Position-Based Assist Pressure in Deep Drawing to Suppress Thinning
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Solution Overview
Problem
Existing assist drawing technologies face challenges in preventing thinning and cracking, especially when working with aluminum alloys, and require extensive machining processes that increase production costs and complexity.
Innovation Solution
The assist drawing device incorporates a punch, drawing die, blank holder, assist punches, and a control system that allows for precise control of assist pressure, blank holder pressure, and cushion pressure in real-time, ensuring optimal forming conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If assist drawing is performed with predetermined assist pressure, then thinning and cracking are suppressed to some extent, but thinning and cracking still occur in drawn products with large width-to-height ratios
Solution Approach 1:
The patent applies dynamics by transitioning from fixed predetermined assist pressure to dynamically adjustable assist pressure that varies according to punch position and material characteristics. The control device adjusts assist pressure in real-time during the drawing process, enabling optimal pressure application at each stage to prevent thinning and cracking while achieving deeper drawing depths.
Solution Approach 2:
The patent implements parameter changes by modifying the assist pressure parameter based on punch position, material type, and drawing depth. The system changes pressure parameters dynamically rather than maintaining a constant value, allowing adaptation to varying stress conditions throughout the drawing process to eliminate thinning and cracking.
2Length of stationary object
If multiple drawing passes or ironing operations are performed to achieve deep drawing, then drawing depth is increased, but production time and complexity increase
Solution Approach 1:
The patent applies preliminary action by preparing optimal assist pressure parameters and punch position schedules in advance through simulation or experimentation. This pre-planning enables single-pass deep drawing by ensuring the correct pressure profile is applied from the start, eliminating the need for multiple subsequent drawing passes or ironing operations.
Solution Approach 2:
The patent implements continuity of useful action by maintaining continuous assist pressure application throughout the entire drawing process in a single pass. The control system ensures uninterrupted pressure support from the beginning to the end of the drawing stroke, enabling deep drawing to be completed in one continuous operation rather than multiple discrete steps.
3Length of stationary object
If multiple punches are used for multi-stage machining, then drawing depth is increased, but the amount of machining oil and coolant oil required increases
Solution Approach 1:
The patent applies the taking out principle by extracting and eliminating the need for multiple punching operations through single-pass assist drawing. By achieving deep drawing in one operation, the system removes the requirement for subsequent machining steps that would generate additional oil consumption, thereby reducing total lubricant and coolant usage.
4Reliability
If assist pressure is increased to prevent thinning and cracking, then material integrity is improved, but the complexity of pressure control increases
Solution Approach 1:
The patent implements feedback by using the control device to monitor punch position and material response in real-time, then adjusting assist pressure accordingly. This closed-loop control ensures material integrity is maintained while managing system complexity through automated feedback-based pressure regulation rather than manual or open-loop control.
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 configuration enables the formation of products with deeper depths while minimizing thinning, cracking, and machining oil usage, thereby reducing production costs and simplifying the process.
Implementation Method 1
a compressive stress field is formed at a location of the material to which the tensile stress is applied during forming so that thinning, cracking, or the like is suppressed
Implementation Method 2
a blank holder that suppresses wrinkles of the blank material 5
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Provided is an assist drawing device (10) by which, when a punch (13) is moved from a stroke start edge toward a stroke end edge in accordance with a command from a control device (200) to a punch drive unit, and drawing is performed in cooperation with a drawing die (14) to thereby perform the drawing, assist drawing is performed while pressing a blank material (M) against the drawing die (14) by a blank holder (15) and pressing both end surfaces of the blank material (M) by assist punches (32A and 32B), and in which the control device (200) includes an assist pressure control unit configured to control an assist punch drive unit such that, when the assist drawing is performed, an assist pressure of the assist punches (32A and 32B) reaches a target assist pressure in accordance with a position of the punch (13).