RU2285848C2 - Method for manufacture of laminated power membrane with annular corrugation - Google Patents

Abstract

FIELD: mechanical engineering, in particular, manufacture of reinforced power membranes with annular corrugation.

SUBSTANCE: method involves making individual layers of membrane and imparting profile of ready article thereto; pressing outer hermetical layers from crude rubber to state at which rubber retains desired profile; manufacturing intermediate layer from non-woven tape by winding blank, fixing annular threads impregnated with binder and holding dry intersecting threads in stretched state above mandrel having length smaller than length of blank; after preliminary profiling of intersecting threads over mandrel surface and fixing their position in supposed bending zone, removing blank from mandrel; turning inside out at thread fastening site and drawing to sizes and profile of ready article. During assembling of prepared layers before laying thereof into mold, end thickened portions of reinforcement layer are to be surrounded with crude rubber.

EFFECT: increased sealing capacity of membrane after short-time high-pressure action.

2 cl, 9 dwg

Description

The invention relates to mechanical engineering and can be used in the manufacture of reinforced rubber products, in particular, power membranes with annular corrugation.

Known methods for the manufacture of power membranes, providing for the preliminary production of power reinforcement by winding a non-woven tape, followed by rubberizing the resulting reinforcement with a rubber compound and their joint vulcanization (ed. Certificate SU 1225790, class B 29 D 31/00, B 29 C 35 / 02, 43/02, 67/14 // B 29 L 31:26, publ. 23.04.86, bull. No. 15; ed. Certificate SU No. 1038660, class F 16 J 3/00, publ. 30.08 .83, bull. No. 32).

Known methods are not suitable for the manufacture of membranes that can withstand high-speed high working pressure (of the order of 50 or more kgf / cm ² ).

Power-reinforced tape strands laden with rubber reduce the deformability of the rubber, which leads to a violation of the tightness and destruction of the membrane. testimonial. No. 1225790 in addition, the rubber collars are destroyed due to the absence of thickenings from reinforced threads in them.

A known method of manufacturing a layered power membrane, providing for the preliminary production of both a layer of power reinforcement and sealed layers, their subsequent assembly and joint vulcanization for bonding all layers only in collars (patent RU No. 2239111, class F 16 J 3/02, publ. 2004, bull. No. 30).

The method, in particular, consists in separately manufacturing the layers before giving them the profile of the finished product, the outer sealed layers being pressed from raw rubber, and the intermediate layer of power reinforcement is made by winding a non-woven tape consisting of intersecting threads enveloping the annular threads.

The known method allows the manufacture of a durable and, in general, sealed membrane withstanding high working pressure. But the rapid impact (of the order of several seconds) of the same pressure causes a rupture or even a detachment of the annular corrugation of the membrane at the place of its bending or destruction of its collar.

The spread in the breaking load of membranes made by this technology is up to 2 times. This is due to the instability of the parameters of the power reinforcement layer, since when the winding forms a non-woven tape on a conical surface, the annular edge threads have different linear speeds due to the difference in the envelope diameters, the cross threads when laying on the mandrel slip randomly relative to each other and relative to the annular threads, which inevitably leads to irregular laying on the surface of the threads, significantly different in length. Therefore, under the influence of pressure, the destruction of the membrane begins with the rupture of shortened threads as the most loaded.

The method according to patent RU No. 2239111 is the closest in technical essence to the claimed one and is selected as the closest analogue (prototype).

The technical problem to which the invention is directed is the development of a more efficient method for manufacturing a layered power membrane, which eliminates the disadvantages of the prototype method.

The technical result that can be obtained by using the invention is to increase the sealing ability of the membrane under short-term exposure to high working pressure by increasing the strength of the annular corrugation and collars.

To solve the problem in a known method of manufacturing a layered power membrane with an annular corrugation, which consists in the preliminary separate production of its layers to give them a finished product profile, in which the outer sealed layers are pressed from raw rubber, and the intermediate layer of power reinforcement with end thickenings intended for the formation of collars, and with an element for the formation of corrugations, perform the winding of a non-woven tape consisting of intersecting threads, enveloping the annular threads, in subsequent according to the invention, the pressing of the sealed layers is completed when the rubber reaches the ability to hold the profile of the finished product, and for the manufacture of a layer of power reinforcement, the workpiece is first wound, and only the ring threads impregnated with the binder are fixed and form annular thickenings from them, and dry intersecting threads are kept in tension over a mandrel of variable cross section with a length less than the length of the wound workpiece, I have a circular ledge to form an element for a corrugation, at the end of winding, cross-threading is shaped over the surface of the mandrel until an expansion band is formed from their excess, the threads profiled along the ledge are coated with a rubber solution, the workpiece is dried until the binder is gelled in the end thickenings, it is removed from the mandrel and turned out until the compensating girdle is combined with the end thickening adjacent to it, then with the help of the device, the workpiece is pulled until reaching the crossing threads equilibrium state and at the same time they are profiled to give it the size and profile of the finished product, after which the final curing of the binder in the end thickenings is carried out, during the assembly of separately manufactured layers and before laying in the mold for the final vulcanization of the sealed layers and the formation of collars, the end thickenings of the power reinforcement raw rubber, while for the manufacture of membranes with corrugation type open body rotation the smallest and largest diameters of the shoulder mandrel for manufacturing The thickness of the reinforcement layer is equal to the smallest and largest diameters of the element intended for the formation of the corrugation.

Distinctive features of the prototype of the claimed method of manufacturing a layered power membrane are the following features:

- the end of the pressing of the sealed layers upon reaching the rubber ability to hold the profile of the finished product;

- manufacturing a layer of power reinforcement, starting with such winding of the workpiece, in which only the annular threads impregnated with a binder are fixed, and end thickenings are formed from them, and the dry intersecting threads are kept in tension over the mandrel;

- the use of a mandrel of variable cross section with a length less than the length of the wound workpiece having an annular ledge to form an element for the corrugation;

- profiling (at the end of winding) of intersecting threads along the surface of the mandrel until the formation of an excess of the compensating belt;

- greasing with a solution of rubber only those threads that are profiled on a ledge for fastening them;

- drying the workpiece to reach the stage of gelatinization of the binder in the end thickenings;

- turning the workpiece (after removal from the mandrel) until the compensating belt is combined with the end thickening adjacent to it;

- pulling the workpiece (using a special tool) until the crossed threads reach the equilibrium state and simultaneously profiling the workpiece to give it the size and profile of the finished product;

- final curing of the binder in the end thickenings only after the above-described eversion, stretching and profiling of the workpiece;

- lining the end thickenings of the layer of power reinforcement with crude rubber during the assembly of all manufactured layers together and before laying them in the mold;

- formation of collars in the process of final vulcanization; as well as

- the equality of the smallest and largest diameters of the annular ledge of the mandrel for the manufacture of a layer of power reinforcement to the smallest and largest diameters of the element of this layer, intended for the formation of corrugations, respectively, in the case of the manufacture of membranes with corrugations of the type of an open body of revolution.

These distinctive features, each individually and all together, are aimed at solving the problem and are significant.

Using the combination of these features in the prior art, analogues and prototype is not found.

A single set of new essential features with common known allows you to solve the problem.

The claimed method is intended for the manufacture of a layered power membrane capable of withstanding the short-term (~ 2 s) exposure to high working pressure of a hot gas with a temperature of about 1500 ° C.

For this type of membrane, it is important that all of its elements can withstand the sudden effects of high loads. This is especially true for the most loaded and most difficult to manufacture elements: corrugations and shoulders.

The prototype method does not allow to achieve the necessary strength of these elements.

In the proposed method, a thorough technological study of the layer of power reinforcement of the membrane was undertaken; high profiling accuracy of all layers and a clear sequence of the formation of corrugations and shoulders were achieved.

The complex shape of the membrane dictated the need to develop a mandrel in the manufacture of the power reinforcement layer, which allows for the subsequent deformation of the wound workpiece in order to form a corrugation element, and a device that helps to achieve an equilibrium state of the threads in this element.

The achievement of the equilibrium state of the threads in the corrugation element, which determines the achievement of the necessary strength, was made possible by maintaining the flexibility of the reinforcement layer throughout the entire manufacturing process due to the relative freedom of movement of all the threads, both circular in the uncured binder, and dry intersecting.

For the same reason, it was possible to achieve the necessary strength of the end thickenings. The annular yarns in the uncured binder were redistributed when pulling the billet, occupying the optimal location, compacted and in this position were fixed in the binder when it was finally cured.

In the finished product, all layers of the membrane retain their structure and ensure the operability of the membrane.

The claimed method is suitable for the manufacture of power membranes with annular corrugations of any shape. The defining moment in this case is the size and shape of the annular ledge of the mandrel for the manufacture of a layer of power reinforcement. A special case of the method is the manufacture of a membrane with a corrugation having the form of an open body of revolution, for example, a torus, an ellipse. In this case, the smallest and largest diameters of the step are equal to the smallest and largest diameters of the element intended for the formation of the corrugation of the membrane.

Obviously, the proposed method is also suitable for the manufacture of power membranes operating under long-term cyclic loading with a lower pressure than indicated.

As an example of the implementation of the proposed method, the manufacture of a layered force membrane with a toroidal annular corrugation is described below.

The invention is illustrated by drawings.

Figure 1 - pre-made membrane layers before assembly, General view;

Figure 2 - a device for winding a workpiece layer of power reinforcement;

Figure 3 - the same device with clamping devices for preliminary profiling of the workpiece on the surface of the mandrel;

Figure 4 - a device for the final formation of a layer of power reinforcement;

5 is a view A in figure 4 (enlarged view);

6 is a mold for the final vulcanization of sealed layers and the formation of collars as the final processes of manufacturing the membrane;

Fig.7 is a view of B in Fig.6;

Fig.8 is a view In Fig.6;

Fig.9 - finished membrane, General view.

The method is as follows.

Each membrane layer is preliminarily made separately, with all the elements of the further formation of the annular corrugation and collars. In this case, a finished product profile is attached to each layer.

Sealed layers 1, 2 (Fig. 1) with elements 3 of the future corrugation and 4 future collars are made of raw rubber by pressing, which is completed when the rubber reaches its ability to hold the profile of the finished product.

Layer 5 of power reinforcement with end thickenings 6, 7 and element 8 of the future corrugation is made in several stages. First, a blank 9 of layer 5 (FIG. 2) is wound on a winding device including a mandrel 10 of variable cross section with a length shorter than the length of the winded blank 9 by an amount L (experimentally determined value) having an annular ledge 11 designed to form an element 8 of layer 5. The smallest diameter d and the largest diameter D of the ledge 11 (figure 2) are equal to the smallest diameter d _e and the largest diameter D _{e of the} element 8 of the layer 5 (figure 1). In the process of winding, the annular yarns 12 (FIG. 2), previously impregnated with a binder, are fixed in the grooves 13 of the device, forming end thickenings 6 and 7 of them. The intersecting yarns 14 enveloping the annular yarns 12 without impregnation with a binder, i.e. in dry form, wound over the mandrel 10, keeping them taut. At the end of winding the workpiece 9 using axial 15 and 16 and ring 17 and 18 clamping devices (Fig. 3), cross-threads 14 are profiled over the surface of the mandrel 10 until an excess of filaments 14 (due to the difference in the lengths of the mandrel 10 and the workpiece 9) of the compensating belt 19, adjacent to the end thickening 6. The threads 14, profiled on the ledge 11, smeared with a solution of rubber for fastening. Then the binder of the annular yarns 12 is dried in the end thickenings 6 and 7 until it gelatinizes, and only after that the preform 9 is removed from the mandrel 10.

The removed workpiece is turned out to align the belt 19 with the end thickening 6 and placed in the device shown in Fig.4.

Here, with the help of clamping 20, fixing 21 and shaping 22 flanges, the workpiece 9 is pulled out, fixing its length along the generatrix, and finally profiled. Profiling of the end thickening 6 between the rings 23 and 24 is shown in FIG. In the process of drawing, the annular yarns 12, being movable relative to each other in an uncured binder, find their optimal location and provide crossover yarns with freedom of redistribution. Due to this, the latter become equidimensional and acquire an equilibrium state.

The blank 9 is kept in the fixture until the binder is finally cured in the end thickenings 6 and 7 and is removed, having obtained the finished layer 5 of power reinforcement with the profile and dimensions of the finished product.

Next, the assembly is carried out as shown in Fig. 1, by placing layer 5 between layers 1 and 2, sheathed with crude rubber (pos. 25 in Figs. 7 and 8), end thickenings 6 and 7 of layer 5 and the whole set is placed in a press form for the final vulcanization of the sealed layers 1, 2 and the formation of collars (Fig.6). In views B and C of Fig.6, presented in Fig.7 and 8, the formation of collars is clearly shown.

The finished membrane has the form shown in Fig.9. It consists of the above layers 1, 2, 5, has an annular toroidal corrugation 26 and collars 27 and 28.

Organic fibers of the SVM-6 brand with a linear density of 29.4 tex were used as crossing threads 14 of layer 5 of power reinforcement.

As the annular yarns 12, an organic thread of the SVM-6 brand with a linear density of 29.4 tex., Impregnated in the process of winding with a polymer binder, was used.

The tight layers 1, 2 are made of a mixture of rubber 51-2110 TU 38 105 1177-88.

The proposed method allows to increase the sealing ability of the membrane both under short-term (~ 2 s) exposure to high working pressure of hot gases with a temperature of the order of + 1500 ° C and during prolonged (up to 1 hour) exposure to pressure of unheated gases or liquids, which was confirmed by test results.

Claims (2)

1. A method of manufacturing a layered power membrane with an annular corrugation, which consists in preliminary separate production of its layers to give them a finished product profile, in which the outer sealed layers are pressed from raw rubber, and the intermediate layer of power reinforcement with end thickenings intended for the formation of collars, and with an element for the formation of corrugations, perform the winding of a non-woven tape consisting of intersecting threads, enveloping the ring threads, in the subsequent assembly and vulcanization of all layers in the mold before fastening them together in collars, characterized in that the pressing of the sealed layers is completed when the rubber is able to hold the profile of the finished product, and for the manufacture of a layer of power reinforcement, the workpiece is first wound, and only the ring threads impregnated with a binder are fixed and end thickenings are formed from them, and dry crossing threads are held in tension over a mandrel of variable cross section with a length shorter than the length of the wound workpiece having an annular ledge to form an element for corrugation, at the end of winding, cross-threading is profiled along the surface of the mandrel until a compensating girdle is formed from their excess, the threads profiled along the ledge are greased with a rubber solution, the workpiece is dried until the binder is gelled in the end thickenings, it is removed from the mandrel and turned out to align the compensating girdle with the priming to it with an end thickening, then with the help of the device, the workpiece is pulled until the crossing threads reach an equilibrium state and at the same time pros iruyut to give it the dimensions and profile of the finished product, after that carried out the final curing of the binder in the terminal thickenings, in the process of assembling separately produced layers and before laying into the mold for final curing airtight layers and form turners end thickening layer strength reinforcement obkladyvayut crude rubber. 2. The method according to claim 1, characterized in that for the manufacture of a membrane with a corrugation of the type of an open body of revolution, the smallest and largest diameters of the shoulder of the mandrel for the manufacture of a layer of power reinforcement are equal to the smallest and largest diameters of the element intended for the formation of the corrugation.

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