机械专业英语翻译.doc

Computer aided design and analysis of the sprue system of an injection mould for optical data storage replication
D. S. Trifonova, . Toshevb
of Information Technology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
of Mechanics and Biomechanics, Bulgarian Academy of Sciences,
1113 Sofia, Bulgaria
4M Partner No 28 BAS, Bulgarian Academy of Sciences
Introduction
Optical disc moulding
•The experience gained up to now in injection moulding of optical disc substrates has shown that the mould occupies a central place and is the most significant part in the production process.
•The obtaining of the geometrically simple substrate, being a circular washer with width of 1,2 mm, diameter of the central hole 15 mm and external diameter varying from
120 mm up to 300 mm, together with the necessity for precise copying of the information structure, the accuracy of the geometric dimensions and the low level of birefringence, imply high requirements towards the mould connected with precise construction and tolerances of the order of microns.
Definition of the technical problem in the optical disc moulding
•A “statement of the problem”for optical disc moulding starts with the fundamental difficulty of filling and packing a mould cavity of much greater length than depth, without incurring high levels of moulded-in stress and orientation.
•The approach applied up to now in solving the problem of cavity filling and formation of the central hole substrate has not declined from the basic method -filling through a thin film circle gate located at the place, where the central hole is to be formed. This requires the use of a complex and precise cropping punch system, removing the circle gate, in order to form the central hole.
The purpose of the paper
•To develop3D CAD models of two basic types of the sprue system and to provide a primary investigation to determine a range of gate size parameters and correct gate locat