Fossula type cam canister production method

Abstract

The invention discloses a making method of fossula-typed cam cylinder, which comprises the following steps: 1. moulding the easy-fusion alloy material into the low-temperature alloy core mould with peripheral surface and at least one cam bar on the peripheral surface; 2. forming a thermal insulating layer on the peripheral surface and cam bar; 3. placing the low-temperature alloy core mould in the moulding model nest of cam cylinder; 4. injecting the liquid plastics in the moulding model nest of cam cylinder; moulding the nest and alloy core model into a cam cylinder to make the cam cylinder possess an internal peripheral surface; 5. fetching the low-temperature alloy core model and cam cylinder out of the moulding nest; 6. heating the low-temperature alloy core model to make the low-temperature alloy core model melt and flow through the internal hole.

Description

technical field [0001] The present invention relates to a lens barrel, in particular to a method for manufacturing an inner-groove cam barrel capable of forming non-penetrating cam grooves on the inner peripheral surface of the lens barrel. Background technique [0002] Existing zoom lenses for cameras generally have a lens barrel and several lens groups. The inner peripheral surface of the lens barrel is formed with a number of non-penetrating cam grooves. Each of the lens groups has a number corresponding to the cam grooves. Guide pins, the cam grooves of the lens barrel push the lens groups through the guide pins, so that the relative distance between the lens groups can be changed to produce a zoom effect. This kind of lens barrel is owing to still have bigger size, therefore, can be by the cooperation of a molding die and a wedge-shaped mandrel that can expand outwards and shrink inward during manufacture (the outer circumference of this kind of wedge-shaped mandrel Th...

AI Technical Summary

Problems solved by technology

[0006] 1. Since the cam groove 301 of the lens barrel 3 is in a through shape, it often causes the problem of light leakage in the zoom lens assembled with the lens barrel 3 . Set a light-blocking outer tube (not shown), so that it is not only inconvenient but also increases the manufacturing cost

[0007] 2. As shown in Figure 3, this molding method utilizes the cam strips 1011 of the molding modules 101 to abut against the outer peripheral surface 201 of the mandrel 2, thereby forming a through-shaped cam groove of the lens barrel 3 301, however, since plastics tend to infiltrate between the cam strips 1011 and the peripheral surface 201 during injection molding, and form irregular hairy protrusions 302, therefore, when the guide pin of the lens group of the zoom lens and the mirror When the cam grooves 301 of the barrel 3 are combined, these hairy protrusions 302 will often affect the smoothness of the guide pin action, resulting in the zoom lens not being able to zoom smoothly. The removal of these burrs 302 is not only troublesome but also increases the production cost.

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