Method for manufacturing green tire and apparatus for building green tire

Abstract

A method and apparatus for manufacturing a green tire capable of preventing the variation of carcass-cord paths between bead cores and disturbances of the carcass cord arrangement are disclosed. An assembly of a bead core and a bead apex rubber is set on the radially outside of a cylindrical carcass assembly, and they are locked with a bead lock ring expanded, while maintain the cylindrical shape. Then, applying tension to the carcass cords between the expanded bead lock rings, the bead apex rubber is folded down towards the tire equator. Further, the edges portions of the carcass are turned up around the bead cores locked.

Description

technical field [0001] The present invention relates to a green tire forming method and a green tire forming apparatus capable of uniformizing the path of carcass cords between bead cores and improving tire uniformity. Background technique [0002] In the case of forming a green tire with a meridian configuration, such as Figure 13 As shown, by using a cylindrical forming drum a and winding a sheet-shaped body including a carcass on the forming drum a, a cylindrical carcass body with both ends protruding from the forming drum a is formed. b. Here, an inner liner rubber, a side rubber, a chafer, and the like may be further included in the sheet-like body. [0003] Thereafter, the diameter of the protruding portion b2 of the carcass cylinder b is reduced to a small diameter cylinder, and the bead core assembly c inserted from both outer ends thereof is moved inward in the axial direction and pressed against the building drum a The bead core assembly c is fixed and positione...

AI Technical Summary

Problems solved by technology

[0005] However, in the conventional method of reducing the diameter of the carcass cylinder b, there is a left-right deviation in the timing of pouring the above-mentioned leaf spring f and / or in the distance between the leaf spring f and the building drum a.

In addition, there is also variation in the shrinking force in each leaf spring f

In addition, since the bead core c2 and the carcass barrel b are not firmly fixed, when the apex c1 is poured and the protruding part b2 is folded back, the offset of the bead core c2 and the carcass barrel b will easily occur

[0006] As a result, the cord arrangement of the carcass is caused to be dense, and there is a problem that the carcass cord path between the bead cores c2, c2 is not uniform in the circumferential direction, reducing the uniformity of the tire.

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