RU2467876C1 - Moulding tool for making reinforced rubber articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to machine building, particularly, to making reinforced rubber articles by curing in moulding tool and may be used for production of elastic support hinges of solid-propellant rocket engine nozzle units. Moulding tool comprises loading chamber to house male die and split ring with inner taper surface to interact with male die face. Said split ring inner taper surface has circular semi-cylindrical grooves made regularly along the circle, their depth decreasing to zero toward their ends. Cross-section of split spring ring is located between said circular grooves in plane crossing ring axis between its ends at angle to loading chamber bottom equal to taper angle of ring inner surface. Moulding features safe, simple and reliable design.

EFFECT: higher quality of nozzle units.

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 and a punch installed in it (see, for example, I.M. Bulanov, V.V. Vorobey. Technology of rocket and aerospace structures from composite materials. - M.: MSTU Publishing House them.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 and a punch installed therein (for example, RF patents Nos. 2,113,998 and 2,195,398).

In such molds, during molding, the elastomer can pass outward from the loading chamber to the gap of a guaranteed size between the internal wall of the loading chamber and the outer surface of the punch, which increases the elastomer consumption and can lead to distortion of the molding process parameters, for example, an unacceptable decrease in pressure, etc. P.

Also known is a mold for the manufacture of reinforced rubber products, including a loading chamber, a split spring ring and a punch installed in it (RF patent No. 2351472), the closest analogue.

The split spring ring is designed to close the gap of a guaranteed size between the outer surface of the punch and the inner wall of the loading chamber, which should exclude the possibility of elastomer leaving the loading chamber through the gap to the outside during molding.

Moreover, the reliable operation of the mold is largely determined by the correct interaction of the split spring ring with the inner wall of the loading chamber and with the end face of the punch during molding.

The ring should fit snugly against the inner wall of the loading chamber and to the end face of the punch and at the same time easily and freely move together with the punch in the loading chamber to its bottom, without skewing relative to the inner wall of the loading chamber, as the elastomer is gradually extruded during molding from the loading chamber through channels Gating system in the forming block.

However, as shown by the practical application of the known design of the mold, in it a split spring ring does not work effectively enough, namely:

the presence of a split spring ring does not completely exclude the possibility of the elastomer escaping from the loading chamber to the outside, since it is possible for the elastomer to enter the cut and the elastomer to pass through the cut due to incomplete closure of the ring edges in the cut zone;

skew of the split spring ring when it is installed relative to the inner wall and the bottom of the loading chamber and the parallelism of the surface of the upper end of the split spring ring relative to the lower end of the punch interacting with it.

It was found that these drawbacks are due to the fact that the location of the section of the spring ring, the slope of the section of the section, etc. not regulated and not tied to the geometric parameters of the split spring ring, and are not defined relative to other elements of the mold.

In addition, in the known design, the operation of installing the ring in the loading chamber when preparing the mold for operation and the operation of extracting the ring from the loading chamber, which must be performed both when preparing the mold for work and when disassembling the mold after manufacture of the product.

This leads to an increase in the complexity of manufacturing rubber products in a known mold.

Thus, in the known design of the mold, the split spring ring in the mold does not sufficiently perform its function, which reduces the reliability of the mold and can lead to a decrease in the quality of manufacturing reinforced rubber products.

The technical task of this invention is to increase the reliability of the mold by ensuring the efficient operation of the split spring ring in the mold, which ultimately leads to improved manufacturing quality of reinforced rubber products.

The technical result is achieved by the fact that in the mold for the manufacture of reinforced rubber products, including a loading chamber, a punch installed in it and a split spring ring with an inner conical surface interacting with the end of the punch are uniformly spaced around the circumference on the inner conical surface of the split spring ring ring grooves having the shape of a cylinder part, the depth of which decreases to zero to their ends, while the cross section of the section of the spring ring ra put between the annular recesses in a plane intersecting the axis of the spring ring between its ends at an angle to the loading chamber bottom, equal to the angle of taper inner surface of the split spring ring.

The execution on the inner conical surface of the split spring ring evenly arranged around the circumference of the annular grooves allows for effective interaction of the end face of the punch with the inner surface of the ring by eliminating unnecessarily strong adhesion of the end face of the punch to the surface of the ring due to the presence of air gaps in the zones of the grooves and to ensure optimal operation of the ring , from the point of view of obtaining the required elasticity of the ring.

The implementation of annular grooves in the form of a cylinder part, the depth of which decreases to zero to their ends, is the best, both from the point of view of ensuring simple manufacturing of grooves, and for the possibility of using grooves as a seat for a special tool when installing the ring in the loading chamber during preparation molds to work and when removing the ring from the loading chamber when disassembling the mold.

The location of the section of the cut along the perimeter of the spring ring between the annular grooves eliminates the influence of grooves on the required elasticity and stiffness of the ring in the cut zone.

The location of the section of the cut in the plane crossing the axis of the spring ring between its ends at an angle to the bottom of the loading chamber equal to the taper angle of the inner surface of the split spring ring is optimal from the point of view of ensuring complete closure of the walls of the ring at the cut when installing the ring in the loading chamber and when moving rings along it down to the bottom of the chamber during molding, while ensuring the parallelism of the ends of the ring.

As a result of numerous experiments, a mold with a split spring ring was developed, the geometric design parameters of which are optimal to ensure efficient operation of the mold.

Figure 1 shows the layout diagram of the mold.

Figure 2 shows the design of a split spring ring.

The mold for the manufacture of reinforced rubber products includes a loading chamber 1, a forming unit 2 and a gating system 3.

At the bottom of the loading chamber 1, a split spring ring 4 is installed with an internal conical surface that interacts when the mold is working with the end face of the punch 5.

On the inner conical surface of the split spring ring 4, annular grooves 6, uniformly arranged around the circumference, having the shape of a cylinder part, are made, the depth of which decreases to zero to their ends.

Section 7 of the spring ring 4 is made between the annular grooves 6.

The cross section of the cut 7 of the spring ring 4 is located in a plane intersecting the axis of the spring ring 4 between its ends at an angle “α” to the bottom of the loading chamber 1, equal to the taper angle “δ” of the inner surface of the split spring ring 4.

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

The elastomer 8 is placed in the loading chamber 1, the surface of the elastomer 8 is leveled, lowering the punch 5 into the loading chamber 1.

After leveling the surface of the elastomer 8, the punch 5 is removed from the loading chamber 1.

Then, using a special tool inserted into the annular grooves 6 on the inner conical surface of the split spring ring 4, set it on the aligned surface of the elastomer 8.

After that, the punch 5 is again lowered into the loading chamber 1, the mold is heated and the elastomer 8 is pressed through the gating system 3 into the product located in the forming block 2.

While the beveled end face of the punch 5 interacts with the inner conical surface of the split spring ring 4.

After the manufacture of the product, the mold is disassembled and the split spring ring 4 is removed using a special tool inserted into the annular grooves 6 on the inner conical surface.

In the proposed mold, a number of high-quality EOSHs of large-sized solid-propellant solid-propellant nozzle blocks were manufactured while ensuring the required manufacturability.

The mold is simple and reliable.

The practical application of the invention made it possible to ensure high-quality manufacture of EOSH of large-sized nozzle blocks of solid propellant rocket engines.

Claims (1)

A mold for the manufacture of reinforced rubber products, including a loading chamber, a punch installed in it and a split spring ring with an inner conical surface interacting with the end of the punch, characterized in that the parts having uniformly arranged circumferences are made on the inner conical surface of the split spring ring cylinder grooves, the depth of which decreases to zero to their ends, while the cross-sectional section of the spring ring is located between the rings grooves in a plane intersecting the axis of the spring ring between its ends at an angle to the bottom of the loading chamber equal to the taper angle of the inner surface of the split spring ring.

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