RU2351472C1 - Press mould for flow moulding - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: present invention pertains to machine building and can be used in making rubber objects through flow moulding a rubber mixture in a press mould, for example, parts of a solid-propellant rocket engine. The technical outcome is achieved through use of a press mould for flow moulding, containing a matrix, loading chamber, die and running channels. The running channels join the cavity of the matrix with the loading chamber. In the loading chamber between the die and the running channels a circular plate is fitted with provision for axial displacement, with circular material samples in the centre part on the side of the die and on the side of the running channels. There are through-openings on the plate in the zone of the material samples, uniformly arranged on the surface of the plates.

EFFECT: increased material utilisation when making objects from rubber mixture in a press mould using flow moulding.

1 dwg

Description

The invention relates to the field of mechanical engineering and can be used in the manufacture of rubber products by injection molding from a rubber mixture in a mold, for example, parts of solid propellant rocket engines (RTTT).

A known injection molding mold containing a matrix, a loading chamber, a punch and gate channels connecting the die cavity with a loading chamber (see, for example, I.M. Bulanov, V.V. Vorobey "Technology of rocket and aerospace structures from composite materials ". M., 1998. Publishing house of MSTU named after N.E.Bauman, p.165-167) - prototype.

The injection molding method is characterized by the presence in the loading chamber of the mold of the pressed-in residue of the rubber mixture after the manufacture of the product, which is due to the need to find a layer of the rubber mixture of a certain thickness in the loading chamber (sufficient to maintain the required pressure on the rubber mixture under the action of the punch) during exposure required hardening of the rubber compound.

The use of a well-known mold for the manufacture of elastic supporting joints has shown that in large-sized molds, the remainder of the rubber mixture in the loading chamber can be significant.

This leads to a decrease in the utilization of the material (rubber compound) in the manufacture of products in the mold by injection molding.

The technical task of this invention is to increase the coefficient of use of the material in the manufacture of products from the rubber compound in the mold by injection molding.

The technical result is achieved by the fact that the known injection molding mold comprising a die, a loading chamber, a punch and a sprue channel connecting the die cavity with a loading chamber, a circular plate with annular samples is mounted with axial movement between the punch and the sprue channels material in the central part from the punch side and from the gate channels. At the same time, through holes are made in the plate in the material sampling zone, uniformly located over the plate area.

The presence of the plate in the loading chamber of the mold allows to reduce the mass of the pressed-in residue of the rubber mixture in the loading chamber after manufacturing the product (the rubber mixture will remain only in small annular samples of the plate material and in its openings) and thereby increase the utilization rate of the material (rubber mixture).

The presence in the central part of the plate of ring samples, the cavities of which are filled with the rubber mixture during the movement of the punch, allows the pressure to be maintained under the action of the punch on the rubber mixture at the shutter speed required to harden the rubber compound. Through holes in the plate provide the possibility of flow of the rubber mixture between the cavities of the ring samples.

The drawing shows a cross section of a mold for injection molding.

The mold contains a matrix 1, an annular loading chamber 2, a punch 3 movably mounted in the loading chamber 2, and gate channels 4 connecting the forming cavity 5 of the matrix 1 with the loading chamber 2.

In the loading chamber 2, a circular plate 6 is mounted with the possibility of axial movement, in which ring samples 7 of material are made in the central part from the side of the punch 3 and from the gate channels 4. In the plate 6, through holes 8 are made in the area of the material samples, uniformly distributed over the area plates 6.

Around the perimeter of the punch 3, in the lower part, there is a sealing split ring 9.

The work of the mold is as follows. The rubber mixture is placed in the preheated loading chamber 2, then a round plate 6 and a sealing split ring 9 are installed. Then, a punch 3 is installed in the loading chamber 2.

When the punch 3 moves under pressure transmitted through the round plate 6, the rubber mixture, heated from the walls of the loading chamber 2 and acquiring the necessary plasticity, is fed through the gate channels 4 into the forming cavity 5 of the matrix 1 and fills it.

When moving the punch 3 with a round plate 6 to the bottom of the loading chamber 2, the rubber mixture fills the ring sample 7 of the material in the plate 6 of the side of the gate channels 4 and through the through holes 8 fills the ring sample 7 of the material from the side of the punch 3.

After filling with the rubber mixture of the forming cavity 5 of the matrix 1 is the shutter speed necessary for the hardening of the rubber mixture.

The presence of the rubber mixture in the ring samples 7 of the round plate 6, communicating through the through holes 8, allows you to maintain under the action of the punch 3 the required pressure on the rubber mixture during exposure.

After aging and hardening of the rubber compound, the mold is disassembled and the finished product is removed.

In the loading chamber, the pressed-in residues of the rubber compound will remain only in small annular samples of the plate material and in its openings.

Using the proposed technical solution allows to increase the utilization of the material in the manufacture of rubber products in the mold by injection molding while ensuring the required manufacturing quality.

Claims (1)

A mold for injection molding containing a die, a loading chamber, a punch and gate channels connecting the die cavity with a loading chamber, characterized in that a circular plate with ring samples of material in the central parts on the side of the punch and on the side of the sprue channels, while through holes are made in the plate in the material sampling zone uniformly located over the plate area.