Hydraulic Return Circuit for Stamping Press Cylinders Without Spring Back
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stamping press systems experience 'spring back' due to the expansion of compressed fluid in cylinders, leading to warping, deformation, or damage to sheet metal during the return stroke, which existing solutions like hydraulic accumulators fail to adequately address.
Innovation Solution
An apparatus with a hydraulic circuit that includes a fluid-operated cylinder, a hydraulic accumulator, and a specific branching system for controlled fluid discharge and intake, featuring one-way valves, pressure limiting valves, and a safety valve to manage fluid pressure and prevent premature return of the cylinder stems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a fluid-operated cylinder is used to support the lower sheet presser element, then the sheet metal can be held firmly during the shaping operation, but the compressed fluid expansion during the return stroke causes spring back effect leading to warping or damage
Solution Approach 1:
The hydraulic circuit is segmented into multiple discharge branches: a first branch for normal operation and a second branch specifically for releasing residual pressure. This segmentation allows the system to handle the fluid discharge in controlled stages, preventing the spring back effect while maintaining holding force during operation.
Solution Approach 2:
The system performs preliminary action by completely expelling the working fluid from the cylinder before the return stroke begins. The hydraulic circuit ensures that all fluid is discharged through the first branch during the downward stroke, leaving no compressed fluid to expand during the return stroke, thereby eliminating spring back.
2Object-affected harmful factors
If the working fluid is completely expelled from the cylinder during the downward stroke, then spring back is eliminated, but the circuit complexity increases with multiple branches and valves
Solution Approach 1:
The hydraulic circuit merges the functions of fluid discharge and pressure release into a unified system with two branches. The first branch handles normal fluid discharge during the downward stroke, while the second branch provides an additional pathway to ensure complete fluid expulsion. This merging approach achieves complete fluid expulsion without requiring entirely separate systems, thus limiting the increase in complexity.
3Object-affected harmful factors
If a hydraulic accumulator is added to control the return stroke, then the spring back effect can be reduced, but the system reliability decreases due to coordination issues between the accumulator and press operation
Solution Approach 1:
The invention extracts the problematic element (compressed fluid remaining in the cylinder) by ensuring its complete removal through the multi-branch hydraulic circuit. By taking out the source of the spring back effect entirely rather than attempting to manage it with an accumulator, the system achieves both spring back elimination and improved reliability through simpler operation.
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
The apparatus effectively reduces the 'spring back' effect, allowing for controlled and adjusted force application, enhancing the reliability and cost-effectiveness of the system for existing stamping presses.
Implementation Method 1
a hydraulic accumulator which is fluidically connected to said at least one cylinder by means of a hydraulic circuit
Implementation Method 2
the fluid, which is inherently compressible, is expelled only partially from the pressurized chamber of the cylinder
Implementation Method 3
avoid even the slightest return of oil into the accumulator if the thrust of the fluid occurs simultaneously with or, worse still, precedes the closure of the one-way valve
Implementation Method 4
a hydraulic controller adapted to receive the pressurized oil, which is moved in the discharge ducts under the thrust of the upper slider of the press
Data Source
AI summary
An apparatus for the controlled return of the stems in cylinders of the types that can be applied to a press for stamping sheet metal, comprising:at least one fluid-operated cylinder),at least one hydraulic accumulator which is fluidically connected to the at least one cylinder by means of a hydraulic circuit which comprises:a duct for the discharge of the working fluid from the at least one cylinder and a duct/branch for the intake of the working fluid in the hydraulic accumulator,a duct for loading the working fluid in the at least one cylinder and at duct/branch for the output of the working fluid from the hydraulic accumulator.