Design method of six-rod shedding mechanism with long pause angle at lowest position of shed

Abstract

The invention discloses a design method of a six-rod shedding mechanism with a long pause angle at the lowest position of a shed. In the design, a connecting rod curve of a crank-rocker mechanism is used, and 8-shaped curve movement is carried out by virtue of a connecting rod point on the extending surface of a first connecting rod of the crank-rocker mechanism; a double-rod component is connected to the connecting rod point in series; the plane motion of the connecting rod point is used for driving a shedding arm to swing by an input connecting rod of the double-rod component; when the connecting rod point moves along the arc section at the right end of the 8-shaped curve, the swing point of the shedding arm is approximately motionless, so that one shedding arm of the shedding mechanism has asymmetric pause angles at two limiting positions and especially has the long pause angle at the lowest position of the shed; furthermore, a hinge joint link mechanism is simple, the stress of a revolute pair is less than that of a lower pair, and the revolute pair is smooth in stress and less in impact, so that the design method is suitable for the improvement and the design of the shedding mechanism of a loom and are especially suitable for a high-speed wide loom.

Description

technical field [0001] The invention belongs to the field of air-jet looms, and relates to a design method of a weft beating mechanism, in particular to a design method of a six-bar shedding mechanism with a long dwell angle at the lowest position of the shed. Background technique [0002] Most shedding mechanisms are composed of a cam swing mechanism and a heald frame system. The biggest defect of the cam rocker mechanism is that the pressure on the contact surface between the cam and the cam rotor is very high, and the friction surface between the cam and the cam rotor is worn due to the high pressure, and the wear aggravates the impact between the cam and the cam rotor. The speed of the loom is getting higher and higher, the high speed brings vibration and unstable movement, and the impact and wear are getting bigger and bigger; especially the negative opening mechanism is closed by the heddle spring. When the loom speed is greater than 650 rpm, The impact is large eno...

AI Technical Summary

Problems solved by technology

The second requirement is to use the link mechanism to achieve a pause at the limit position of the opening arm. The theoretical profile of the cam can easily make a certain section of the profile an arc, and the constant arc radius is equivalent to the pause of the output motion. Using the link mechanism It is difficult to achieve a pause, and only an approximate pause can be achieved

[0004] There is no way to accurately reproduce the given trajectory by using the link curve to reproduce the given trajectory

Images