Flexible mechanism with negative poisson ratio characteristic

Abstract

The invention discloses a flexible mechanism with a negative poisson ratio characteristic. The flexible mechanism is formed by stacking a plurality of same flexible units, wherein the flexible units are symmetrical flexible Sarrus mechanisms. The flexible mechanism is characterized by comprising two same isosceles trapezoid flat plates and four same rectangular flat plates, wherein the six flat plates are connected through notch type flexible hinges to form a single-degree-of-freedom spatial six-rod flexible mechanism; the six flat plates are a first isosceles trapezoid plate, a second isosceles trapezoid plate, a first rectangular plate, a second rectangular plate, a third rectangular plate and a fourth rectangular plate respectively; the notch type flexible hinges are arranged on opposite sides of each flat plate; the flexible units are periodically stacked through a shared flat plate to form a hollow cylindrical flexible mechanism; when the flexible mechanism is subjected to pressure in the axis direction of a cylinder, the mechanism generates axis shrinkage and radial shrinkage; when the flexible mechanism is subjected to tension in the axis direction of the cylinder, the flexible mechanism generates axis extension and radial extension; and the flexible mechanism can be used in a precise snakelike robot to adjust the size of the robot.

Description

technical field [0001] The invention relates to a hollow cylindrical flexible mechanism, in particular to a flexible mechanism with negative Poisson's ratio characteristics. Background technique [0002] The Poisson's ratio of ordinary materials is generally positive. When it is under pressure in one direction, it will shrink in this direction and expand in the vertical direction. When a structure with negative Poisson's ratio is subjected to pressure in one direction, it will shrink in that direction and in the perpendicular direction at the same time. Negative Poisson's ratio structures have good rebound characteristics and fracture resistance, so they are widely used in buffering energy absorption, pressure bearing, explosion protection, robots, etc. Usually, negative Poisson's ratio structures are formed by periodic superposition of specially shaped cells. In the invention patent with the publication number CN110015255A, an energy-absorbing box is disclosed. The energy...

AI Technical Summary

Problems solved by technology

The existing negative Poisson's ratio structure superimposed by the cell circumference is more flexible and has more deformable areas, which is suitable for non-precision applications such as buffering and energy absorption; however, the deformation of this structure is complicated, and it is difficult to establish an accurate kinematic model , the shape controllability is not high, and the application in robots has limitations

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