Robot Arm Stopper Structure for Impact Force Absorption
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Solution Overview
Problem
Existing robots face damage due to impacts when stoppers contact each other during arm rotation, as described in JP-A-11-123690, US2015/246450A1, JPS60123280A, JP2007050499A, JP2023006866A, and JP5360288B2, without effective mechanisms to mitigate collision forces.
Innovation Solution
A robot system with a stopper unit featuring a stopper member, contact members, and through holes with long hole shapes and tapered or curved sides to distribute and absorb impact forces, reducing arm collisions by friction and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stopper restricts the angle between arms using contact between fixed-side and movable-side stoppers, then the arm angle is restricted to a predetermined angle or more, but impact damage occurs to the arms due to collision between stoppers
Solution Approach 1:
A cushioning member (elastic body) is introduced between the fixed-side stopper and movable-side stopper to mediate the contact interaction. This intermediary element absorbs impact energy through deformation, preventing direct rigid contact between stoppers and eliminating impact damage to the arms while maintaining the angle restriction function.
Solution Approach 2:
The elastic cushioning member is pre-installed between the stoppers to provide advance protection against impact. When the arms reach the predetermined angle, the cushioning member deforms to absorb the collision energy before it can transmit damaging forces to the arm structures.
2Device complexity
If conventional stopper structures are used with rigid contact between stoppers, then the structure is simple, but excessive load causes damage to the stopper block and mounting components
Solution Approach 1:
The cushioning member serves as an intermediary between the rigid stopper components, allowing the simple overall structure to be maintained while the elastic element protects the stopper block and mounting components from excessive loads through controlled deformation during contact.
3Measurement precision
If rigid stoppers are used to restrict arm movement, then the angle restriction is precise, but wear and damage occur at contact surfaces
Solution Approach 1:
The elastic cushioning member acts as a mediator that maintains precise angle restriction through its deformation characteristics while simultaneously protecting the contact surfaces of the stoppers from wear and damage by absorbing impact energy.
Solution Approach 2:
The cushioning member changes its physical state from rigid to elastic during contact, allowing it to deform and absorb impact energy. This parameter change enables the system to maintain angle restriction precision while reducing wear on contact surfaces through elastic deformation rather than rigid impact.
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 stopper unit design minimizes damage to robot arms by distributing and relaxing impact forces through friction and deformation, enhancing durability and reducing wear.
Implementation Method 1
a cushioning member (elastic body) between the fixed-side stopper and the movable-side stopper
Implementation Method 2
The stopper unit design minimizes damage to robot arms by distributing and relaxing impact forces through friction and deformation
Data Source
Figure 1
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Figure 3
AI summary
A robot (2) includes a first member (6), a second member (7) coupled rotatably around a rotation axis (J2) to the first member, a restricting member (15) having a contact portion (19) in contact with the first member when an angle between the first member and the second member is a predetermined angle and a through hole (24) formed therein, a first locking member (16) passing through the through hole and locking the restricting member to the second member, and a second locking member (17) locking the restricting member to the second member, wherein, as seen from a direction along the rotation axis, a distance between the contact portion and the first locking member is shorter than a distance between the contact portion and the second locking member, and a length of the through hole in a direction from the first locking member to the contact portion is longer than a diameter of the first locking member.