Safety Unit With Dynamic Stiffness Mechanism
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Solution Overview
Problem
Existing safety devices for industrial facilities and mechanical equipment face limitations in actively responding to external impacts due to the time-consuming active control type and struggle with non-linear stable control operations in passive control types, leading to inefficiencies and potential failures.
Innovation Solution
A safety unit with a combination of a spring and mechanism that provides high stiffness for small external forces and low stiffness for larger forces, allowing for rapid response and absorption of impacts without the need for sensors or actuators, enabling compact modularization and high reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If passive control-type safety device (spring or damper) is used, then manufacturing cost is reduced and response speed is increased, but it is difficult to implement desired non-linear stable control operation
Solution Approach 1:
The safety device employs a dynamic structure where the stiffness of the support means changes based on the applied external force. When external force is small, the support means maintains high stiffness for stable operation. When external force exceeds a threshold, the support means transitions to low stiffness to absorb impact energy, achieving non-linear control without complex sensors or actuators
Solution Approach 2:
The invention changes the stiffness parameter of the support means dynamically based on the magnitude of external force. By designing the support means with specific geometric and material properties, the system automatically transitions between high-stiffness and low-stiffness states, enabling non-linear control characteristics suitable for both normal operation and impact absorption
2Adaptability or versatility
If active control-type safety device is used, then ability to actively cope with change in external condition is improved, but response time is greater than physical impact time
Solution Approach 1:
The safety device is designed to respond automatically to external impacts without requiring external sensors, controllers, or power sources. The support means inherently detects and responds to force magnitude through its mechanical structure, achieving self-service operation that eliminates the time delay associated with electronic sensing and control systems
Solution Approach 2:
The invention replaces electronic sensing and control systems with a purely mechanical solution. The support means uses mechanical elements (links, sliders, springs) that automatically respond to force applications through physical laws, eliminating the need for sensors, controllers, and actuators that would introduce response delays
3Object-affected harmful factors
If spring is mounted at joint of robot, then external impact can be absorbed, but spring is deformed by daily external force and robot arm droops
Solution Approach 1:
The support means provides dynamically adjustable stiffness that adapts to operating conditions. During normal operation with small external forces, the support means maintains high stiffness to prevent robot arm droop and ensure stable positioning. When impact forces exceed the threshold, the support means transitions to low stiffness to absorb impact energy, achieving both stability and impact protection
4Strength
If safety device with high stiffness is used, then structural integrity is maintained, but impact absorption capability is reduced
Solution Approach 1:
The safety device employs a dynamic stiffness mechanism where the support means transitions between high-stiffness and low-stiffness states based on applied force magnitude. During normal operation, high stiffness maintains structural integrity and precise positioning. During impact events exceeding the force threshold, the support means transitions to low stiffness to absorb impact energy through controlled deformation, achieving both structural integrity and impact absorption
Solution Approach 2:
The invention changes the stiffness parameter of the support means based on the magnitude of external force. The mechanical design ensures that for forces below the threshold, the support means operates in a high-stiffness regime maintaining structural rigidity. For forces exceeding the threshold, the support means transitions to a low-stiffness regime that allows controlled deformation for impact energy absorption
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 safety unit achieves excellent response speed and reliability while reducing manufacturing costs, enabling its use in various applications such as robot arms, revolving doors, and road safety facilities by effectively absorbing impacts and maintaining structural integrity.
Implementation Method 1
an elastic member exerting an elastic force on the slider
Implementation Method 2
when an external force having a value greater than a predetermined threshold value is exerted thereto, the safety unit easily surrenders to the external force to be broken off, thus accompanying a change in its outer appearance or structure
Data Source
AI summary
The present invention provides a safety unit comprising: a case; a rotary linkage disposed at one end thereof at the outside of the case and rotatably mounted at the other end thereof to the case; a force transfer shaft mounted to one side of the rotary linkage in such a fashion as to be oriented perpendicular to the rotating plane of the rotary linkage; a crank linkage rotatably mounted at one end thereof to the inner side of the case and adapted to abut against the force transfer shaft at the outer circumferential edge thereof so as to be transferred with an external force to be rotatably moved; and a support means rotatably connected to the other end of the crank linkage and adapted to allow for the rotation of the crank linkage when an external force having a value larger than a predetermined threshold value is exerted to the rotary linkage.