Mathematical Model of Cam Profile Based on Heald Frame Motion Characteristics

Honghuan Yin,Junqiang Peng,Hongbin Yu,Hongyu Shao

doi:10.1155/2020/2106373

Honghuan Yin, Junqiang Peng + Show 2 more

Open Access

https://doi.org/10.1155/2020/2106373

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Abstract

In this paper, the transmission process of the heald frame driven by the dobby is analyzed. The equivalent motion model of the dobby modulator, the eccentric mechanism, and the motion transmission unit are constructed. Then, based on the given movement characteristics of the heald frame, the mathematical model is built to achieve the cam pitch curve and the cam profile of the modulator. The numerical solution method for this is developed. The preparation of a mathematical model for the new concept of the solving cam profile based on the motion characteristics of heald frames is explained in this study. By setting a 11th polynomial motion law of the heald frame, due to the inconsistency between the outward and return motion laws of the crank-rocker mechanism, an asymmetrical cam profile is obtained under the premise of ensuring that the heald frame’s ascending and descending motions are consistent. Through the kinematics simulation analysis, the correctness of the reverse process is verified.

Highlights

At present, the weaving technology is focused towards higher speeds, higher efficiency, and easier control and operation [1, 2]
A mathematical model was used to ascertain the relationship between heald frame motion characteristics and cam profile
It is possible to ascertain the relationship between heald frame motion characteristics and cam profile

Summary

Introduction

The weaving technology is focused towards higher speeds, higher efficiency, and easier control and operation [1, 2]. Rotary dobbies convert the rotational motion of the main shaft of the weaving machine into an up-down frame motion by means of various gears, arms, and eccentrics (cams) [7, 8]. E forwardmost and rearmost positions of the lifting arm 15 correspond to the lower and higher positions of the heald frame 21, respectively Due to this construction, the eccentric mechanism generates a heald frame motion only for plain weaving. In order to convert it to a rotary dobby mechanism, it is necessary to include the necessary means to get the lifting arm 15 (the heald frame) dwelt at its forwardmost and rearmost positions as many loom revolutions as required by the weave [3]

Mathematical Model of the Shedding Motion

Results and Discussion

Conclusions