Installation Technology And Equipment Of Spring In Transfer-needle

Transgfer-needle is used in computerized flast machine, it needs hundreds and thousands of transfer-needle to be reciprocating motion. In order to loop formation, needle has to pass through a narrow gap which is formed by needle bar and spring, which makes the spring’s installation be more difficult.Spring is a special part of transfer-needle, it has great effet on transfer-neele’s quality, so it’s necessary to know the best parameters to do the spring’s installation. The following work is done for it:1) Mechanical methods choosed to inatall it, at the same time, design and manufacture of welding fixture, which are used in the real production.2) Analysis of the installation process to know that it’s a large deformation problem. Spring’s installation quality is effected by the width of punch and groove, and the value of indentation depth and the radius.3) Study of the process parameters to know their influnce law and essence by proper methods. Besides, the welding fixture and machine is debugged the finite modle is made and so on.Influnce law and essence is obtained by the simulation and experiments results, which are as following:1) With the punch’s increased, the stress value of punch is increased and the CFN is decreased. While the width is more than2.4mm, the needle bar has plastic deformation. The stress value is increased for the width be more than2.6mm.2) With the indentation depth’s increased, the stress value is no changed, and the CFN is increased.3) With the groove size’s increased, the stress value is no changed and the CFN is decreased.4) The stress value is decreased with the radius’s range of0.02mm-0.11mm, and it is increased lightly with the range of0.12-0.14mm, and the CFN is decreased.Thinking of all the aspects, the best installation parameters is that the punch’s with is2.4mm, the radius is0.11mm, the groove’s size is2.00-2.03mm, the indentation is0.08-0.2mm. And the evaluation index is the spring’s installation, the CFN is more than70N, the main stress value in punch is less than1850Mpa, and the spring and the needle is good.The results are used in real production, and the process is stable.