Gas Spring With Variable Bore For Vibration Damping
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Solution Overview
Problem
Existing gas springs used in sheet metal stamping experience heat generation and reduced lifetime due to calibrating the hole of smaller diameter during the return stroke, which limits work frequency and service life, and alternative solutions like a cylindrical brake cause pressure issues leading to fatigue or extrusion problems.
Innovation Solution
A gas spring design with a hollow cylindrical body and a plunger that includes a first and second gas chamber, where the second inner diameter is greater than the first, allowing gas passage only at the end of the return stroke, reducing heat input and increasing gas volume, thus reducing maximum pressure and prolonging service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the hole of smaller diameter is calibrated to control gas flow during rod return, then the rod return speed is controlled and vibrations are reduced, but heat generation increases and service life decreases
Solution Approach 1:
The gas spring is divided into two separate gas chambers (first and second chambers) with independent flow control paths. The first chamber handles the return stroke through a restricted hole, while the second chamber handles the descent stroke through check valves, allowing optimized control for each direction without compromising the other
Solution Approach 2:
The system dynamically changes its gas flow characteristics based on the direction of movement. During rod return, gas flows through the smaller hole providing controlled deceleration. During press descent, check valves open to allow rapid gas flow, adapting the flow resistance to the operational phase
2Stability of the object's composition
If the hole of smaller diameter is calibrated to delay rod return, then vibrations from rapid opening are reduced, but work frequency is limited due to heat generation
Solution Approach 1:
The gas flow control is segmented into two independent paths: one for rod return (through the smaller hole) and one for press descent (through check valves). This allows vibration control during return without restricting the speed during descent, maintaining high work frequency capability
Solution Approach 2:
The system exhibits periodic behavior where check valves open during the power stroke to allow rapid gas flow, then close during the return stroke to enable controlled flow through the smaller hole. This periodic valve operation separates the vibration control function from the productivity-critical descent phase
3Stability of the object's composition
If a cylindrical brake is added to slow down rod return, then controlled return is achieved, but pressure in the airlock chamber increases causing fatigue and extrusion problems
Solution Approach 1:
The harmful third airlock chamber and cylindrical brake mechanism are completely removed from the system. Instead, rod return control is achieved by utilizing the existing first gas chamber and restricting flow through the smaller hole, eliminating the source of excessive pressure and its associated fatigue and extrusion problems
Solution Approach 2:
Flow restriction is applied locally at the specific location where it is needed (the hole in the plunger for the first chamber) rather than through a separate brake mechanism. This localized restriction achieves rod return control without creating the high-pressure airlock chamber that causes fatigue and extrusion
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 allows the gas spring to operate at higher frequencies and extends its service life by minimizing heat generation and reducing energy consumption during compression, while maintaining controlled rod return and reducing vibrations.
Implementation Method 1
The plunger also comprises a second hole that has a reduced section compared to the first ones and which allows the passage of gas in both directions
Implementation Method 2
the gas that is in the second chamber tries to pass to the first chamber due to the pressure difference generated
Data Source
Figure 1
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AI summary
The invention relates to a gas spring that has slowed return of the rod only over the final part of the retraction travel thereof, in such a manner as to avoid the vibration, that arise from rapid opening of the press. To that end, the hollow cylindrical body (1) comprises a first longitudinal zone located close to the open end (1) thereof which has a first internal diameter (10) and a second longitudinal zone located downstream of the first longitudinal zone which has a second internal diameter (11), where the second internal diameter (11) is greater than the first internal diameter (10).