RU2438869C1 - Method of preparing moluds for production of reinforced rubber articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to machine building, particularly, to producing industrial rubber goods by mould vulcanization. Proposed method comprises placing and securing mould on press to create elastomer moulding pressure in displacing made die in cylindrical chamber of the mould. Note here that L-section ring is produced with smaller ID corresponding to male die diameter and larger ID equal to loading chamber OD. Mould fitted on the press, said ring is fitted on loading chamber to align smaller ID ring with loading chamber outer surface. Male die is fitted through said ring into loading chamber to center it relative to the latter, and, then, said ring is removed_.

EFFECT: possibility to produce reinforced shock absorbers and elastic support hinges.

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Description

The invention relates to the field of engineering, in particular to the technology of manufacturing rubber products by vulcanization in the mold, and can be used for the manufacture of reinforced shock absorbers and elastic support joints (EOS).

Known molds for the manufacture of reinforced rubber products (see, for example, patents of the Russian Federation No. 2131998 and 2302944).

These molds contain a cylindrical loading chamber filled with an elastomer with a punch moving in it.

Hydraulic presses are used for pressing, providing constant pressure on the pressed part during the whole pressing time, while the upper movable plate moves to the press installed on the lower fixed plate and fixed on it with the elastomer loaded into it when moving the plunger of the press it by the punch and the elastomer under the action of the punch in the loading chamber of the mold is subjected to pressing.

A known method of preparation for the operation of the mold for the manufacture of reinforced rubber products, including installing and securing the mold on the press to create a pressing pressure in it when moving the punch in a cylindrical loading chamber (see, for example, I.M. Bulanov, V. V. Vorobei. Technology of rocket and aerospace structures from composite materials. - M.: Publishing House of MSTU named after NE Bauman, 1998 - pp. 156-159) - the closest analogue.

The known method allows you to create the desired pressing pressure in the mold required for the manufacture of rubber products.

However, the use of this method for the manufacture of an EOS of a large-sized nozzle block of a solid fuel rocket engine (RTTT) showed that in a mold with a cylindrical loading chamber of significant size when the punch moves under the pressure of the press, the elastomer can exit from the loading chamber outward, by the gap between the punch and the inner wall of the loading chamber.

This leads to the need for secondary loading of the mold chamber with an elastomer to provide the amount required for molding the product.

For the secondary loading, it is necessary to remove the punch from the loading chamber and reinstall it after loading the chamber with an elastomer, which leads to an increase in the complexity of the method.

In addition, molding in two stages can lead to a decrease in the quality of manufacturing reinforced rubber products in the mold.

It was established that the elastomer exits from the loading chamber to the outside due to the misaligned location of the punch relative to the cylindrical loading chamber when it is installed in the loading chamber after placing the elastomer in it.

The misaligned location of the punch results in a non-uniform circumferential distribution of the gap between the punch and the inner wall of the cylindrical loading chamber of the mold.

In some cases, especially with large diameters of the mold punch, the clearance in the radial plane can reach the maximum value on one side, and on the opposite side the punch can touch the wall of the loading chamber, which is unacceptable.

Thus, in the known method of preparing for the operation of the mold for the manufacture of reinforced rubber products, the required centering of the punch in the loading chamber is not provided, which leads to a decrease in the quality of the manufactured products and increase the complexity of the work.

The technical task of this invention is to improve the quality of manufactured products and reduce the complexity of the method of preparing for the operation of the mold for the manufacture of reinforced rubber products.

The technical result is achieved by the fact that in the method of preparing the mold for manufacturing reinforced rubber products, including installing and securing the mold on the press to create an elastomer pressing pressure when moving the punch in the cylindrical loading chamber of the mold, a L-shaped ring is made cross-section, the smaller inner diameter of which corresponds to the diameter of the punch, and the larger inner diameter is equal to the outer diameter of the loading chamber, after installing to form a press wear ring on the loading chamber, aligning the surface of the ring with the larger inner diameter of the outer surface of the loading chamber is set through the ring into the charging plunger chamber, centering it relative to the loading chamber, fix the mold on the press, after which the ring is removed.

The centering of the punch relative to the cylindrical loading chamber of the mold allows you to ensure uniform clearance between the punch and the inner surface of the loading chamber, required for reliable operation of the mold size.

The use of a prefabricated removable ring of the proposed shape and sizes corresponding to the mold elements allows the punch to be centered most simply and with the required accuracy.

The essence of the method is illustrated by drawings.

Figure 1 shows a diagram of a mold with a centering ring installed.

Figure 2 shows a diagram of the mold with the installed punch after removing the centering ring.

Preparation of the mold to work by the proposed method is as follows.

A ring 1 is made of a L-shaped cross section, the smaller inner diameter D _{1 of} which corresponds to the diameter D _{2 of the} punch 2, and the larger inner diameter D ₃ is equal to the outer diameter D _{4 of the} cylindrical loading chamber 3 of the mold.

The diameter D _{1 of the} ring 1 is fitted along the punch 2, providing the required clearance, for example, 0.2-0.4 mm per side.

A forming block is assembled from the upper 4 and lower 5 forming rings with reinforcing elements 7 installed in them by means of clamps 6.

Place the elastomer 8 in the loading chamber 3, install the mold on the lower stationary plate of the press and fix it (not shown), put the ring 1 on the loading chamber 3, combining the surface of the ring 1 with a large inner diameter D ₃ with the outer cylindrical surface (diameter D ₄ ) boot chamber 3.

Set through the ring 1 in the loading chamber 3, the punch 2, centering it relative to the loading chamber 3, fix the punch 2 on the upper movable plate of the press (not shown).

Raise the upper plate of the press with the punch 2, removing it from the loading chamber 3 and the ring 1, after which the ring 1 is removed.

When moving the plunger of the press, its upper movable plate with the punch 2 moves to the mold, as a result of which the centered punch 2 moves along the walls of the loading chamber 3 with a uniform gap and the elastomer 8 is pressed into the product.

Using the proposed method, a number of high-quality EOSHs of large-sized bells of RDTT nozzle blocks were manufactured while ensuring the required manufacturability.

Claims (1)

A method of preparing a mold for manufacturing reinforced rubber products, comprising installing and securing a mold on a press to create an elastomer pressing pressure when moving a punch in a cylindrical loading chamber of a mold, characterized in that a ring of an L-shaped cross section is made, the smaller inner diameter of which corresponds to the diameter of the punch, and the larger inner diameter is equal to the outer diameter of the loading chamber, after putting the mold on the press t ring onto the loading chamber, combining the surface of the ring with a large inner diameter with the outer surface of the loading chamber, install a punch through the ring into the loading chamber, centering it relative to the loading chamber, fix the mold on the press, after which the ring is removed.

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