RU2457943C1 - Mould for producing reinforced rubber articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of reinforced rubber parts and may be used for making elastic thrust hinges used in solid-propellant rocket engines. Mould used for production of reinforced rubber parts comprises loading chamber, gating system and moulding unit. Mould incorporates die for check test pieces made up of ring embracing moulding unit and arranged along therewith in single case provided with through taper holes arranged vertically along perimetre. Every said through taper hole accommodates insert made up of two halves with cylindrical plugs rigidly fitted therein and representing heads with opposed flat surface. Clearance is arranged between head surfaces communicated via horizontal channel with moulding unit cavity.

EFFECT: efficient quality control.

2 dwg

Description

The invention relates to the field of engineering, in particular to the technology of manufacturing reinforced rubber products by vulcanization in a mold, and can be used to produce elastic supporting hinges (EOS) of nozzle blocks of solid propellant rocket engines (RTTT).

Known molds for the manufacture of rubber products, including a loading chamber, a forming unit and a gating system (see, for example, I.M. Bulanov, V.V. Vorobey. Technology of rocket and aerospace structures from composite materials. - M.: Publishing House MSTU named after N.E.Bauman, 1998 - p. 156-159, 165-167).

In addition, molds for the manufacture of reinforced rubber products are known, including a loading chamber, a forming unit and a gating system (see, for example, RF patents Nos. 2,113,998 and 2,351,472).

Also known is a mold for the manufacture of reinforced rubber products with floor-mounted reinforcement elements and elastomer layers, including a loading chamber, a forming unit and a gating system (RF patent No. 2302944), the closest analogue.

In the manufacture of products, especially the EOS of nozzle blocks, constant quality control is required in the mold.

One of the most effective methods of quality control of manufactured products is the determination of physical, mechanical and structural properties on samples (so-called samples - witnesses).

When choosing a method of manufacturing samples, it is necessary to correctly model all the conditions and processes of manufacturing the product.

In known mold designs, the manufacture of samples indicative of the quality of the product, parallel to the manufacture of the product, is not provided.

Obtaining samples after the manufacture of the product is difficult and, in some cases, impossible, since on products made in the mold by injection molding, there is practically no burr from which the samples could be made.

The production of samples from the remainder of the elastomer, pressed into the loading chamber, or the elastomer filling the gating channels, is also difficult and does not give a reliable idea of the quality of the product.

Thus, the known design of the mold does not allow for effective quality control of the manufacture of rubber products on witness samples and obtaining such samples in this design is practically impossible.

The technical task of this invention is the implementation of effective quality control of the manufacture of rubber products on witness samples obtained in a specially designed form that is part of the proposed mold design, while ensuring that the conditions for forming the elastomer of the sample are as close as possible to the conditions for forming the elastomer between the elements of the product reinforcement.

The technical result is achieved in that the mold for the manufacture of reinforced rubber products with floor-mounted reinforcement elements and elastomer layers, including a loading chamber, a sprue system and a forming block, is provided with a witness specimen shape made in the form of a covering forming block and placed with it in one holder of the ring, in which vertically oriented through conical holes are made uniformly around the perimeter, each of which contains two halves of a palm with cylindrical plugs installed in it and rigidly fixed, made in the form of fungi with flat caps directed towards each other, with the formation of a gap between them, the cavity of which is communicated by a horizontally oriented channel with the cavity of the forming block.

The gap between the caps of the fungi is equal to the gap between the reinforcement elements of the manufactured product.

Fungi are made of the same material as the reinforcement elements of the manufactured product.

The presence of a specially designed mold for witness specimens, communicated by channels with the cavity of the forming block, allows us to produce the number of samples required for testing and to model the processes of forming elastomer layers between reinforcing elements most correctly.

Fulfillment of the mold for witness samples in the form of a ring covering the forming unit and a ring placed with it in the same holder makes it possible to bring the formation conditions of the sample elastomer (heating and pressure) as close as possible to the conditions of forming the elastomer between the reinforcement elements.

The execution in the ring of vertically oriented through conical holes allows easy and reliable installation of fungi for the manufacture of samples in the mold for sample witnesses.

The implementation of the liner, in which the cylindrical plugs are placed, from two halves makes it easy and simple to extract a test piece from the liner without mechanical damage to the plugs and the integrity of the pressed elastomer.

The implementation of cylindrical plugs in the form of fungi with flat caps directed towards each other allows one to obtain a witness specimen that completely imitates a fragment of the product design, ready for use for all types of mechanical tests, ensuring ease of fixing in the testing machine and insensitivity to the fixing method.

Fulfillment of the gap between the caps of the fungi equal to the gap between the reinforcing elements of the manufactured product allows you to get an elastomer sample of the same thickness as on the product, which is important when determining the movements and deformations of the elastomer on the samples during mechanical tests, for example, shear, tension bending and compression.

The execution of fungi from the same material as the reinforcing elements of the manufactured product, allows you to get a sample with the same adhesion value of the elastomer as on the product, while the surface of the fungi must be prepared similar to the surface of the elements of the reinforcement of the product, for example, one and the same the same adhesive composition on reinforcing elements and on the caps of specimen witnesses.

Figure 1 shows the layout diagram of the mold containing the mold for specimen witnesses.

Figure 2 shows the design of the mold for witnesses and its elements.

The mold for the manufacture of reinforced rubber products with floor-mounted reinforcement elements and elastomer layers includes a loading chamber 1, a forming unit 2 and a gating system 3.

The forming unit 2 is housed in a ferrule 4, which also contains a form 5 for specimen witnesses.

Form 5 for witness samples is made in the form of a ring 6, covering the forming block 2.

In the ring 6, vertically oriented through conical holes 7 are made, which are evenly spaced around the perimeter of the ring 6.

An insert 8 is installed in each hole 7, made in the form of a cage consisting of two halves 9 and 10 with a conical outer surface and an inner cylindrical surface.

Inside the insert 8 there are cylindrical plugs 11 and 12 made in the form of fungi with flat caps 13 directed towards each other.

Cylindrical plugs 11 and 12 are rigidly fixed in the liner 8 using pins 14.

An annular gap “a” is formed between the caps 13 of the fungi, the cavity of which is communicated by a horizontally oriented channel 15 with the cavity of the forming block 2.

The width "a" of the gap between the caps 13 of the fungi is equal to the size of the gap "b" between the elements of the reinforcement 16 of the manufactured product.

Fungi are made of the same material as the reinforcing elements 16 of the manufactured product.

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

The assembled mold 5 for witness specimens and the forming block 2 with the reinforcing elements placed in it in the clip 4 are installed and the mold is finally assembled.

The elastomer 17 is placed in the loading chamber 1, the mold is heated and the elastomer 17 is pressed through the gate system into the product.

Moreover, after filling with the elastomer 17 of the forming block 2, the elastomer 17 enters through the channels 15 into the gaps "a" of the forming block 2, fills them and through the similar channels (not shown) out of the mold, which indicates the end of the molding process.

The mold is disassembled, the finished product is removed from the forming block 2 and the witness samples (fungi with the elastomer 17 pressed into the gap “a” between their hats 13) from the mold 5.

On the specimen witnesses, the physicomechanical and structural properties of the elastomer pressed into the product, adhesion, etc. are determined.

The presence of the mold for witness samples in the proposed design of the mold does not lead to its significant complication.

In the proposed mold, a number of high-quality EOSHs of large-sized RDTT nozzle blocks were manufactured while ensuring the required manufacturability, and elastomer witness samples were obtained, the properties of which fully correspond to the properties of the elastomer layers pressed between the reinforcement elements of the rubber product.

The mold is simple and reliable.

The practical application of the invention made it possible to ensure effective quality control of the manufacture of EOS of large-sized nozzle blocks of solid propellant rocket engines according to witness samples.

Claims (3)

 1. A mold for the manufacture of reinforced rubber products with floor-mounted reinforcement elements and elastomer layers, including a loading chamber, a sprue system and a forming block, characterized in that it is provided with a witness specimen shape made in the form of a covering forming block and placed with it in one ring holder, in which vertically oriented through conical holes are uniformly distributed along the perimeter, in each of which there is a liner consisting of two halves with The cylindrical plugs made in it and rigidly fixed, made in the form of fungi with flat caps directed to each other, form a gap between them, the cavity of which is communicated by a horizontally oriented channel with the cavity of the forming block. 2. The mold according to claim 1, characterized in that the gap between the caps of the fungi is equal to the gap between the reinforcement elements of the manufactured product. 3. The mold according to claim 1, characterized in that the fungi are made of the same material as the reinforcement elements of the manufactured product.

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