DK141239B - PROCEDURE FOR CONTINUOUS PREPARATION OF STRENGTHENED ADEN HIGH PRESSURE HOSE AND APPARATUS FOR EXERCISING MACHINE - Google Patents

Description

in 141239

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuous manufacture of reinforced high pressure hoses comprising a hose core, a reinforcing layer and a covering layer in which the hose core is formed of vulcanizable elastomer, is pulled from an extruder in axial direction and stiffened radially over a certain distance. for which stretch more reinforcing layers are wound tightly outside the hose core and the hose core is vulcanized. The invention further relates to an apparatus for carrying out the method.

The known methods for producing high pressure hoses of composite materials with elastic supports can in principle be divided into methods for making with mandrels and methods for making without mandrels.

In methods of making mandrels, the individual material parts of the hose, such as the hose cores, reinforcement inserts and cover layers are individually placed on a mandrel serving as the mold core and having a finite length. The mandrel length is limited due to easier removability of the mold and is usually 20-40 m. As a mandrel, for the most part 20 is a solid steel mandrel for small hose diameters, while for larger hose diameters an aluminum pipe is used due to the easier handling (DT -PS 521.226).

The methods of producing high-pressure hoses with mandrels enable the metal or textile reinforcement layers needed for the hose structure to be tightly disposed around the hose core. If the mandrel was not present, such tightly applied reinforcement layers, especially in the case of a hose with a large internal width, namely an unauthorized constriction of the hose core. However, it has not hitherto been possible to produce high-pressure hoses by methods of manufacture with mandrels by a continuous process, as is possible by mandreless methods especially suitable for the production of large series of tubes with small tube dimensions.

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The method according to the invention is characterized in that the radial stiffening of the hose core takes place only within the area in which the hose core is affected by external forces due to the tightening of the reinforcing layers and that the hose core is further stiffened frictionally or by direct engagement with the hose core material. within this area. This provides a method for continuously producing infinite lengths of high pressure hoses by means of a mandrel. This is particularly due to the fact that the hose core is only stiffened at the site where the reinforcing layers are wound, whereby the friction exerted by the stiffener and the torsion-preventing device is kept to such a minimum that the continuous manufacture has proved possible. .

According to the invention, a suitable apparatus for carrying out the method according to the invention, comprising a mandrel, the periphery of which, as known from German Patent Specification No. 1,704,768, is formed by inclined pivoting rollers for abutment against the inner periphery of the hose core. that the mandrel is adapted to be driven opposite the rotary device by an associated winding device for the reinforcing layers, thereby avoiding twisting of the hose core in a simple manner.

Thus, the reinforcing layers are embedded in e.g. rubber, that the individual reinforcing elements are not permanently deformed by the transformations to which the high-pressure hose is subjected when its cross-section is changed from the flat oval during the transport to the circular shape, and vice versa.

For this purpose, the wall thickness of the hose core must be kept so large that the permissible bending radius of the reinforcing elements is not exceeded even in extreme deformations of the cross-section.

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A particularly convenient apparatus for carrying out the method according to the invention, which has a rotary winding device for the reinforcing layers and a hollow mandrel having circumferentially distributed outlet openings for a liquid sliding means, according to the invention is characterized in that the mandrel for the region of the force influence due to the winding device is formed as hydrostatic or aero = static bearing, and that at or immediately after the winding device one or more endless bands 10 can be wound which can be wound frictionally on and on top of the winding device. reinforcing layer within at least one winding and having a system of guide rollers running around with the associated winding device and arranged to be braked up or driven opposite the winding direction. Hereby, a device is provided which ensures easy passage of the hose core across the stiffener.

According to the invention, a further outer aerostatic support bearing 20 can be arranged both in the forward and in the area of the hydrostatic or aerostatic bearing, whereby the hose can slide under low friction between the two stationary bearings without being deformed.

In particular, according to the invention, the aerodynamic support bearing may be part of a coil holder included in a winding device and at its end projected in the feed direction, have guide holes serving scan wire passages.

The invention is explained below with reference to the drawing, in which fig. 1 shows a longitudinal section through part of an embodiment of an apparatus for carrying out the method 30 according to the invention; FIG. 2 is a longitudinal section through another embodiment of an apparatus for carrying out the method according to the invention; FIG. 3 is a longitudinal section through a third embodiment of an apparatus for carrying out the method according to the invention; FIG. 4 is a longitudinal section through a fourth embodiment of an apparatus for carrying out the method according to the invention; FIG. 5 is a section along line A-B of FIG. 3 or 4, FIG. 5a is a section of a similar section through an endless ribbon having a continuous cavity with internal cavities; 6 and 7 are sections similar to those shown in FIG. 5, showing various forms of endless bands in connection with hollow mandrels; FIG. 8 schematically shows an apparatus for carrying out the method 15 according to the invention, in which the mandrel used is locked magnetically or hydraulically; FIG. Fig. 9 is a perspective view of a part of an apparatus for carrying out the method according to the invention and with an additional means for abolishing the torque at which the reinforcing layer acts on the hose core during winding. 9a is a section along the line C-D of FIG. 9, FIG. 10 and 10a are a section of a hose made by the method according to the invention, seen in cross-section and side, respectively.

In the method according to the invention, the hose is made on a stationary mandrel whose surface is moved with the hose built up on the mandrel with the least possible friction in the production direction. Such a mandrel is a permanent component of the actual hose machine, and as a result only present at the beginning of the production line up to and possibly into the heating zone. It may, depending on the embodiment, consist of one or more pieces so that the mandrel segments, seen in the production direction, are firmly connected to each other and present only where the equilibrium must be maintained to counteract a deformation of the circular cross section which as a result of the application of a new material layer, in particular 10 of a cord or wire layer to the hose, which results in pressure externally directed into the interior of the hose.

The method according to the invention can be carried out in three main variants: a) with a roller mandrel, such as the one shown in fig. 1. A hose-15 core 2 leaving an extruder 1 is held circular by a slight air overpressure in the hose inner 3 and is extensively cooled before the next work process. At constant speed v, it reaches the first winding machine 4, where it is applied to a reinforcing layer of braided yarns or metal wires. These reinforcing layers must be placed extremely accurately in a high-pressure hose and in any case a soft and unstable core must be entrapped.

This according to the invention can be done by means of a roller mandrel 5, which advantageously rotates opposite the direction in which the winding machine 4 rotates. The roller mandrel 5 again comprises as far as possible a large number of slightly barrel-shaped rollers 6 arranged around the circumference of the mandrel, the axis of rotation having an adjustable oblique position with respect to the center line of the hose.

By placing the rollers 6 in a given oblique position and pulling the hose at a given speed v, the rpm of the roller mandrel 5 is adjusted so that the rollers 6 run in a helical manner on the inner surface of the hose core 2.

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The roller circle diameter is also variable, in order that the same roller diameter can be used to produce as wide a range of hoses as possible. In addition, the inner diameter D2 of the hose can also be corrected in this way.

5 If another supporting mandrel 7 is used in another winding machine 7, it can be rotated opposite the first mandrel by means of a flexible drive shaft 8 so that opposite directed forces outweigh each other.

After the application of two reinforcing layers of textile or metal 10, the hose being built up is usually already pressurized so that for further support a multiple atmosphere overpressure is sufficient within the interior of the hose. pressure medium is suitably heated to the temperature necessary for later heating of the hose.

In order to obtain a seal between the sections 3 and 9 of the hose interior, a sliding seal 10 is pivotally attached to the last roller ring 5.

In cases where the torque transmitted 20 from the winding machine 4 or 7 to the hose 2 is not kept in equilibrium with an equally large but opposite torque from the roller mandrel 5, additional torque protection 11 must be provided to avoid twisting of the the hose 2 and an inaccurately placed wire layer. This rotation lock 25 is conveniently provided by a tightly sealed connection between the hose surface and a plurality of projections arranged to cut superficially into the hose core or a groove rollers rolling on the surface. The point of attack of the forces from the rotation protection must be as close as possible to the place where the reinforcing layers run.

b) with a hydrostatic or aerostatic mandrel as shown in FIG. 2nd

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The extruded and cooled hose core 2 is prevented in a compression at one or more locations due to an external force exertion by means of a fixed support mandrel 13, which optionally rotates about its own axis. To prevent contact between the hose core 2 and the surface of the mandrel, a gap 15 filled with a bed medium 14 must be maintained therebetween. This bed medium flows under pressure through a supply pipe 15a and capillaries 16 and into several bed pockets 17, from which it extends beyond the annular slot 10 15 in the interior of the hose 3. From there it is fed back through the return openings 18 to the pressure generator.

In places where the hose cross-section does not have sufficient mold stability, an additional external support bed 19 is used. For this purpose, an aerostatic bed is suitably used since a liquid film between the hose core 2 and the reinforcing layer 20 is detrimental to the quality of the hose.

In this way, the hose 2 slides a small constant velocity friction between the two fixed bearings 13 and 19. The outer bearing 19 is suitably part of the winding machine 12 of the winding machine 4 and 7 and includes on its front side guide holes 21 which act as wire passages. In this way, a bearing is provided which grips tightly around the entire outside of the hose until some distance into the place where the threads run.

C) by means of a stationary mandrel 23 such as that shown in FIG. 3. On the surface of this mandrel, a plurality of endless flexible belts 24 slid in the direction of production under low friction by the hose core 2. A prerequisite is that the friction between the inside of the hose core 2 30 and the outside of the belts 24 is substantially greater than the friction between the belts 24 and the mandrel 23. If the friction between the belts 24 and the mandrel 23 is nonetheless too high in certain production cases, the belts can also be driven at the hose pull rate v by a drive device 25. Especially with small internal hose diameters 8 however, the requirement of a suitable drive device in the mandrel interior is difficult due to lack of space.

In some cases, the drive device 25 can also be placed outside (see Fig. 4). Such placement is especially advantageous if the hose core is not extruded but wound by strips 26.

The endless belts 24 can be designed in different ways and adapted to the requirements of the friction ratio of the hose core (FIG.

5, 6, 7). FIG. 5 shows a section along line A-B through the mandrel of FIG. 3 or 4. The surface 23 of the mandrel carries a number of endless bands which are rigid in the longitudinal direction, but though their center line is so flexible that they readily adapt to the curvature of the mandrel. The strips are at the edges 27 by which they adjoin each other along the sides, so formed that, by the influence of an external pressure, they adhere closely to one another. On their underside, they are provided with guide projections 29 which fit into correspondingly shaped recesses 30 in the surface of the mandrel to prevent the bands from moving laterally under the action of a torque of 20 M 2. The recesses 31 may also be located on the underside of the straps and run on corresponding guide strips 32 on the surface of the mandrel (Fig. 7).

In order to lower the friction between the belts 24 and the mandrel 23, it is possible to supply a lubricant via holes.

In the case of non-metallic tapes, it is advantageous to provide these with one or more pull-up devices 28, such as steel wires arranged within the strips and extending in their longitudinal direction.

In those cases where the hose after its casing is surrounded by a heated winding to exert an exterior pressure on the hose cross section during heating so as to obtain a better quality, this pressure can be raised even more if the bonding 24 interior 33 is filled with a gas or a liquid. In this case, the belts 24 must be made of a resilient material which allows a desired expansion of the thickness of the belt due to the heat expansion of the belt filling.

5 Even with a sufficiently good seal of the strips 24 along the edges 27, it is not possible to completely avoid an impression of these edges in the form of grooves on the inside of the finished hose. However, in order to reduce the number of these grooves and at the same time the flow resistance using the hose 10, the number of belts moved along the surface of the mandrel must be kept as low as possible, and in extreme cases a belt can be sufficient (fig. 6 and 7). In order to facilitate the redirection of the endless band at the ends of the mandrel 23, the band can be provided either wholly (Fig. 6) or only partially (Fig. 7) with a small thickness, so that the band having a circular cross-section on the mandrel's surface. easily folds at the end of the mandrel so that it can run back inside the mandrel 34.

In order to fix the entire mandrel 23 in the hose pull-off direction 20, the mandrel must be connected to a mandrel holder means 22 by means of a mandrel holder 22. As the belt 24 must pass around these mandrels on its way through the interior of the mandrel, its circular cross-section is broken in at least one place 38.

However, this can also be avoided if it is able to fix the mandrel 23 in its axial bearing without any mechanical locking device 22, 35 by means of a strong magnetic field acting on it from its inner 36 and / or its outer 37. hose made in this way will internally be completely free of furrows and in this respect will not be distinguishable from a conventionally made mandrel hose.

An axial mandrel lock without the holding means 22 is also needed in the case where the hose core 27 is manufactured by a separate working process (Fig. 8). The hose core 2, which runs off a drum 39, here runs through the cladding 40 and heat zone 41. The finished hose is cooled and then wound on a drum 42.

In this case, too, in order to be able to work with loose mandrel and still ensure continuous fabrication, the pipe piece 23 carrying the endless belts 24 must be locked in the axial direction without any fixed screw connection to the hose machine.

This can be done magnetically (Fig. 6) or hydraulically (Fig. 8) in such a way that the mandrel is locked by forces.

In the case of the hydraulic mandrel lock, the mandrel ends carry via pistons 35 and retaining means 22 (see Fig. 6) piston surfaces Aq and 43 which provide a seal of inner hose compartments 44 and 45 relative to each other.

The gas or liquid pressure within these compartments is connected to each other via a regulating device in such a way that the resulting force F ^ i ~ poA0 ', as the difference between the products of pressure and associated piston surface, is at equilibrium at all times. with the frictional force R acting between the belts 24 and the mandrel 23. The axial position of the mandrel 23 can be detected by known non-destructive material testing methods, e.g. by means of x-rays, and can be corrected by changing the pressure difference by means of said control device.

Since the unarmed hose core 2 is usually unable to withstand any large internal pressure in section 44 without an unacceptable deformation, this pressure is also allowed to adjust equal to the atmospheric pressure whereby the front piston surface AQ lapses.

In many cases, it can be absolutely advantageous to combine the described processes a), b) and c) with each other.

Is the hose cross-section e.g. in a hose whose first reinforcing layer has been applied by the method c) already so stable that the following layers can be applied by the method b) or in some circumstances even using a gas or liquid filling in the interior of the hose; this can be readily realized provided a media separation is made by one or more suitable seals 10.

In each of processes a) - c), it is possible that, despite the aforementioned precautions, excessive torque is exerted on the hose cross section, in particular due to the application of the different reinforcing layers and the associated effect of external forces in the one tangential direction to the respective outer hose diameters. The FIG. 9, it is precisely the task of most to abolish this torque by an approximately equal, but opposite, torque, and to convert the disturbing external forces to internal forces.

This is generally accomplished by an endless and flexible band 48 running on the hose core near or together with the reinforcing layer 47, consisting of multiple wires or steel wires, by friction taking over a certain portion of the wire-running voltage. This effect is made possible partly by a rough surface of the band 48 and partly by the relative velocity between the wire or the bundle 47 and the band 48 due to their different winding diameters on the hose core 2. As shown in FIG. 9a by means of a section C-D in FIG. 9, the endless belt 48 running at the speed w produces a force S 1 which acts on the hose core 2 itself with a tangential traction and exerts a torque Mt1 on it. If the belt sealing force S2, when driving or braking a rotating roller system 49-52, respectively, is kept equal to the sealing force, the torque thus obtained is equal to Mt1 'and the abrasive's external forces result in a constriction of the belt portion 53 which is helical wound up on the hose core, as well as an application force R which does not produce any torque.

Claims (3)

This static reaction force R will maintain equilibrium by means of the stationary mandrel in processes a) - c). Claims. A method for continuous manufacture of reinforced high pressure hoses comprising a hose core, a reinforcing layer and a cover layer, wherein the hose core is formed of vulcanizable elastomers, is pulled from an extruder in axial direction and stiffened radially over a certain distance, within which stretches several reinforcing layers wound tightly outside the hose core and the hose core is vulcanized, characterized in that the radial stiffening of the hose core takes place only within the area in which the hose core is affected by external forces due to the tightening of the reinforcing layers and that hose The core is further stiffened frictionally or by direct engagement with the material of the hose core against twisting in this area. Apparatus for carrying out the method according to claim 1, comprising a mandrel, the periphery of which is formed by obliquely arranged, rotatable rollers for abutment against the inner periphery of the hose core, characterized in that the mandrel (5) is arranged to be operable opposite the rotary device. of an associated winding device for the reinforcing layers. 25 Apparatus for carrying out the method according to claim 1, which has a rotary winding device for the reinforcing layers and a hollow mandrel having circumferentially distributed outlet openings for a liquid lubricant, characterized in that the mandrel is within the range of the force effect as as a result of the winding device is formed as a hydrostatic or aerostatic bearing (13) and that at or immediately after the winding device is arranged