RU1812119C - Diaphragm for forming and curing of pneumatic tyre casings - Google Patents

Abstract

Usage: molding and vulcanization of tires of pneumatic tires using a diaphragm with high performance properties. Summary of the invention: the diaphragm is made in the form of an elastic shell 1 having a middle torus part 2 and end sections with beads 3 connected to each other by one or more oblique-conical surfaces 4. The latter are made with a generatrix 6 located at an acute angle to the central axis of the diaphragm. 2 ill.

Description

Joint venture

with

The invention relates to the field of manufacturing pneumatic tires and is intended for forming and vulcanizing tires.

The purpose of the invention is to improve the quality of the diaphragm and its operational properties.

On Fig, 1 shows the diaphragm in the meridional section; figure 2 is the same with the clamping discs and the blank of the tire.

The diaphragm is made in the form of an elastic shell 1 with a middle torus part 2, which is connected to the flanges 3 by means of one or more inclined-conical surfaces 4, which are interconnected by segments of the spherical surface of the ball groove 5. Together, the formed profile is close to the unfolded finished tire profile, taking into account the diametrical

and profile hoods necessary to prevent creasing.

The inclined-conical surface 4 adjacent to the beads 3 is made with a generatrix 6 located at an acute angle to the central axis of the diaphragm.

It has been experimentally established that in order to achieve this goal, the tilt angles of the 6 inclined-conical surfaces 4 to the central axis of the diaphragm have the following values: a 25 ± 5 °, / 75 ± 5 ° and 15 ± 5 °.

The diaphragm is mounted in the clamping discs 7, 8, 9 and 10. To ensure alignment of the tire blank 11 and the diaphragm at the time of forming and fitting the side of the tire 11 on the side rings of the mold, the flange of the clamping discs 8 and 10 is made along the profile of the inner contour of the diaphragm .

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The operation of the diaphragm is as follows.

A tire preform 11 is loaded onto an elongated and evacuated diaphragm 1. The alignment of the tire preform and the diaphragm during loading and forming is provided by the oblique-conical surfaces 4 of the diaphragm.

When the forming agent is fed into the inner cavity of the diaphragm due to the inclined conical surface 4, the side of the tire 11 slides and is mounted on the side rings of the mold.

In the molding process, the diaphragm first comes into contact with the tire blank in the middle torus part 2, then sequentially from the torus part to the side zone, air is forced out of the space between the diaphragm and the tire blank 11.

Then, a heat agent is applied and a vulcanization process is carried out.

The implementation of inclined-conical surfaces with generators located at an acute angle to the central axis of the diaphragm, allows to improve the process

a single recess (removal) of the core from the diaphragm in the manufacture of the latter. When removing the core, the end sections and flanges are mainly subjected to tensile stresses, which improves the manufacturing quality of the diaphragm and also significantly increases its reliability and durability. In addition, it provides precision when forming tires, which is especially important for radial steel cord tires.

Claims (1)

SUMMARY OF THE INVENTION A diaphragm for forming and vulcanizing tires of pneumatic tires in the form of an elastic shell having a middle torus portion and end sections with flanges interconnected by one or more oblique-conical surfaces, characterized in that, with In order to improve the quality of the diaphragm and its operational properties, the oblique-conical surface adjacent to the flanges is made with a generatrix located at an acute angle to the central axis of the diaphragm. FIG. G