DE102006006902B4 - Plastic pressure vessel and process for its manufacture - Google Patents

Abstract

A hydraulic or pneumatic pressure reservoir for commercial vehicles, trains or firefighting systems is assembly from components made of fiber-reinforced polyethylene, polypropylene or polyamide. The reservoir outer shell is multi-layered elongated ellipse. The ratio of the poles to the center section is in the range 1:2.5 to 1:5, with a smooth rounded transition between the two. Further claimed is a manufacturing process for the reservoir.

Description

The The invention relates to a pressure vessel made of plastic, in particular Air receiver for brake power systems and pneumatic auxiliary equipment on trucks, trucks, buses, rail vehicles or at fire extinguishing systems, the as a multi-layered body is formed, comprising one of injection molded, made of liners made of fiber-reinforced Polyethylene, polypropylene or polyamide, composite liner body with a central mantle area and polar caps, being in the polar caps Connection sleeves are molded captive, one arranged on the liner body Reinforcing layer of fiberglass tape and one on the reinforcing layer arranged injection-molded captive wrapping of fiber-reinforced polyethylene, Polypropylene or polyamide.

The The invention further relates to a method for producing a pressure vessel Plastic, in particular compressed air tank for brake power and pneumatic auxiliary directions on trucks, trucks, buses, rail vehicles or on Fire extinguishing systems, at first Liner parts with hemispherical Polkappen made of glass fiber reinforced Polyethylene, polypropylene or polyamide granules by injection molding in one injection mold are formed, wherein in the center of the pole caps introduced connection sleeves be enclosed by the plastic, the liner parts by joining in one joiner to a liner body with each other be joined, the joined liner body with a reinforcing layer of glass fibers in cross-lamination in one Wrapping machine is wound and the thus-reinforced liner body with a serving made of fiber-reinforced Polyethylene, polypropylene or polyamide is overmoulded.

The use of liners made of thermoplastic material in the manufacture of pressure vessels is well known (see, inter alia EP 0 635 672 A1 . DE 197 51 411 C1 . DE 198 32 145 A1 . DE 100 00 705 A1 . EP 147 042 A1 . EP 0 666 450 A1 . WO 84/03065 A1 . WO 95/22030 A1 ).

That's how it is EP 0 635 672 A1 a pressure vessel, in particular accumulator tank for brake power systems and pneumatic auxiliary equipment on trucks, trucks, buses, rail vehicles, etc. or for fire-extinguishing systems known, which consists of a liquid-tight injection-molded liner or thermoplastic body such as polypropylene, polyethylene, polyamide, and the like. consists, are provided in the openings for connection sleeves and arranged on the liner armor layer. The liner consists of a form of lost shape formed body made of short fiberglass reinforced thermoplastic and is surrounded on all sides by a one-piece captive shell. The sheath consists of short fibers, preferably glass fibers, reinforced and filled polypropylene or polyamide or modified polypropylene ethers or polyphenylsulfide or polyetherimide. The reinforcing layer is composed of cross-laminated with about 55 ° to each other wound glass fibers or metal wires or wire mesh together.

In the DE 198 32 145 A1 and the DE 199 37 470 A1 containers are disclosed for storing solid, liquid and / or gaseous media under an operating pressure above atmospheric pressure, wherein the container encloses a cavity provided for storing the medium and wherein at least one connection for loading and / or unloading is provided. The pressure vessel consists, at least in part, of a tube, which in turn is made of fiber-reinforced thermoplastic, the material of the tube being more than 10% by volume of fibers having an average fiber length of more than 50 mm. The floor is formed as a separate part and also consists of a fiber-plastic composite material with short, long or continuous fibers. The floor is curved inwardly formed in the container space. At the bottom of a circumferential collar is arranged, which abuts against the inner wall of the central part and is connected thereto.

According to the prior art DE 198 32 145 A1 it is a composite pressure vessel for storing gaseous media under pressure with a plastic liner and two throat pieces arranged in the neck area and with a liner reinforcing winding a fiber composite material, of which at least one formed for receiving a screw-threaded having a valve is and both neck pieces are provided in the pressure vessel facing the corner region with a flat truncated cone-like collar which is surrounded on the inside by the liner and the outside of the reinforcing winding. The pole caps of the pressure vessel are provided with a shock absorbing layer.

The DE 100 00 705 A1 describes a plastic core container reinforced with a fiber-plastic composite for storing liquid and / or gaseous media under pressure, which has one or more connecting pieces in the neck and / or bottom and / or cylindrical container part, of which at least one connecting piece for receiving a screw-in cylindrical or conical thread having pressure line feed such as a valve or pipe connection is formed. In the connecting pin of the plastic core container is a cylindrical insert with egg At least two seals are arranged in such a way that at least one seal between the insert and the inner surface of the plastic connection pin of the plastic core container and at least one further seal between the insert and pressure line feed is arranged.

After EP 0 147 042 A1 For example, there is known a container for storing and transporting fluids under pressure which has a thermoplastic inner blown liner of polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride or polyvinyldiene chloride which is provided with an outer layer of carbon fibers, polyamide fibers, glass fibers, glass fiber reinforced polyester fibers or glass fiber reinforced phenolic epoxy resin is wrapped.

Furthermore, from the EP 0 518 272 A1 a container is known, which is intended to receive a pressurized fluid, with a jacket of substantially cylindrical shape and two substantially spherical bottoms, which close the shell at its ends. The container comprises an outer shell of composite material, an inner shell rigidly connected to the outer shell, a first opening piercing the inner and outer sheath, and a reinforcing element of the outer sheath around the first opening located inside the outer shell located and also includes an opening, which cooperates with the second opening. The first opening is located in the jacket area and is provided with means for attaching the container. The reinforcing element is inserted between the inner and outer sheaths. It has a flat side aligned with the inside of the container and a contour adapted to maintain the outer surface of the container. The reinforcing element occupies at least the entire length of the shell.

The inner shell Is cast, the shape is chosen so that the insertion of the reinforcing element not that for the container intended profile disturbs. The outer shell is made made of a fibrous material that is in contact with the reinforcing element provided inner shell is wound up. Subsequently becomes a heat treatment of the container performed.

The Indian EP 0 666 450 A1 described pressure vessel comprises a liner made of plastic with a cylindrical central part, two dome-shaped end portions and a liners umfüllenden outer shell having a plurality of radially superposed tangential windings and axial windings of a fiber-reinforced plastic, wherein the lowermost winding is formed as a tangential winding and in axial Direction extends substantially over the cylindrical central part of the liner. The lowermost winding in the middle region has a first thickness and merges at both ends into a winding edge, which has a second thickness which is greater than the first thickness.

It is also known to wind the liner with glass-fiber reinforced tapes both longitudinally and transversely to the liner axis (see DE 21 52 123 A . DE 2 423 497 A1 . DE 2 516 395 A1 . DE 38 21 852 A1 . EP 0 147 042 A1 . EP 0 588 836 A1 . EP 0 635 672 A1 . EP 0 666 450 A1 . WO 90/01649 A1 . US 31 12 234 A . US 49 05 856 A ,

From the DE 21 152 123 A is a pressure vessel, in particular compressed gas tank known, consisting of a dimensionally stable, rotationally symmetrical, gas-tight and cylindrical in its central region inner container, two coaxial from the outside to the bottom of the inner container mounted pole pieces and wound on the inner container with detection of the pole pieces, of continuous filaments and cured , Plastic laminated outer sheath is made, wherein a bottom of the inner container and the patch thereon pole piece with an opening for tight connection of a valve o. The like. Are provided.

In the known prior art DE 24 123 497 A1 a method for producing a fiber-reinforced resin impregnated hollow body in the winding process is claimed with a mandrel remaining in the finished part, wherein as a mandrel a structure of the structure of the hollow body mitbewirkender fiber reinforced support body is formed and cured. The support body has two end caps and is provided with at least one of the support body and the end caps engaging winding layer. The winding layers are applied in farm by longitudinal windings with a sharp winding angle and in the form of circumferential windings of approximately 90 °.

The DE 25 16 395 A1 discloses a pressure vessel formed as an aluminum vessel having a cylindrical portion and a hood-shaped end portion at each end of the cylindrical portion, the cylindrical and hood-shaped portions being of substantially equal thickness. Around the aluminum vessel, a winding arrangement of alternately polar oriented and circumferentially oriented glass fiber fabric is provided. At least one circumferentially oriented winding assembly is wound over the junctions between the cylindrical and hood-shaped end portions. The wrapping is in a preloaded condition so that compressive forces are applied to the outer surface of the vessel.

After DE 38 21 852 A1 is known a gas cylinder for high gas pressure, which consists of an aluminum liner and a circumferential layer of glass fiber reinforced plastic, wherein the liner has a cylindrical portion and spherically shaped pole caps with connection piece. The liner, including its polar caps, is provided with a first layer of cross-wound glass fibers. A second layer is provided mainly in the cylindrical part of the liner, the glass fibers being in a circumferential winding.

The WO 01/57429 A1 describes a fiber-reinforced pressure vessel whose gaseous or liquid-tight body is completely wrapped with sliver, wherein the slivers are not embedded in a matrix and at least a number of slivers are freely movable relative to each other. The slivers are wound so that as soon as the pressure vessel is under internal pressure, the slivers are loaded exactly in their longitudinal direction.

From the EP 0 588 836 A1 There is known a plastic tank which is reinforced with glass fibers or corresponding reinforcing filaments and is composed of preferably cylindrical tank halves, each having a bottom and one of the two floors having a connection opening. The open ends of the tank halves are tapered and inserted into each other as an insert in a receiving part and held together by an adhesive. The tank halves include outer and inner layers which are substantially transverse reinforcing strands, with the inner layer of the insert and the outer layer of the female part each containing a layer of densely-spaced reinforcing strands in a number of layers of flat-lying rovings. This prior art also discloses a method of manufacturing a reinforcing body of fiber strands for insertion into a mold for casting a fiber-reinforced cylinder having a closed end wound with longitudinal and transverse reinforcing strands joined together by heating fusible resin powder.

Furthermore, from the US 31 12 234 A a method for producing a fiber-wound steel pressure vessel known in which first the cylindrical container is wound approximately in its longitudinal direction and then in the transverse direction with fiber strands.

Also for the integration of connection sleeves or other components in composite containers a variety of solutions is known ( DE 25 38 433 A1 . DE 195 26 154 A1 . DE 196 31 546 C1 . DE 197 51 411 C1 . DE 100 00 705 A1 . EP 0 550 951 A1 . EP 0 553 728 A1 . WO 94/23240 A1 . US 46 85 589 A . US 49 05 856 A . US 52 87 988 A ).

So revealed the DE 25 38 433 A1 a pressure vessel consisting of a dimensionally stable, gas-tight and in its central region cylindrical inner container, two externally placed on the bottoms of the inner container coaxial pole pieces and a wound under detection of the pole pieces on the inner container outer shell of glass fiber reinforced plastic, wherein a bottom of the inner container and the are provided with a flange-shaped part patch pole piece with an opening for tight connection of a connector and the inner container at its opening edge has an integrally formed axially outwardly directed and cylindrical neck whose contour matches that of the pole piece and the connector and by the with the Pole piece is screwed by screw connection related fitting radially against the pole piece.

Of the Inner container neck, the inner contour of the pole piece and the outer contour of the connector are conical to the outside narrowed.

In the known composite container after DE 195 26 154 A1 for storage of gaseous media under pressure, the liner is made of plastic and has two openings located in the neck region, in each of which an opening closing and / or sealing neck piece is arranged, of which at least one is designed to receive a screw-valve. Both neck pieces are provided with a flat in the pressure container end region with a flat-running, frustoconical collar which is surrounded by the elements of the liner and / or the reinforcing winding, as well as with the center axis as symmetry axis enclosing and extending from the inside recess, which, in the case of the valve neck piece, merges into the bore of the valve screw area.

In another known composite pressure vessel ( DE 196 31 546 C1 ) for storing gaseous media under pressure with a plastic liner and two throat pieces arranged in the neck region and with a liner reinforcing winding of a fiber composite material, of which at least one is designed to receive a screwable, a cylindrical thread having valve and both neck pieces in the the pressure vessel facing end portion is provided with a flat-running frustoconical collar, the edge of which is strongly rounded and whose inclination is adapted to the contour of the liner in the transition region from the cylindrical shell region to the neck region, the reinforcing winding comes in adjacent to the neck piece Be rich of the top of the collar and in the edge area of the top as well as the bottom of the collar of the liner to the plant.

All these known pressure vessels made of plastic have a cylindrical center, taken from the metal container construction or shell part, closed by corresponding bottoms on both sides becomes. Especially with dome-shaped or curved inwards Soils are created in transition from the mantle to the ground area stress spikes, which are common to Break at these transitions or to release lead the bottom part of the shell part. The basic rule is the smaller the transition radius is, the larger the risk of a voltage break despite reinforcing measures of different Art.

Even the transition from a cylindrical jacket region into a spherical pole region with a slightly larger radius can not sufficiently reduce the risk of breakage, especially with continuous and decaying permanent stress, as occurs in particular in brake power plants ( DE 38 21 852 A1 ). In the bending area (transition), the voltage lines of the voltage transformers extending in the container jacket are reinforced from the cylindrical jacket into the bottom area by the very high load changes, so that the breaking voltage is necessarily exceeded. Therefore, the known pressure vessel, especially for brake air systems in trucks and rail vehicles have not been able to prevail. There are therefore still metallic, especially steel pressure vessels with all their disadvantages such as heavy weight, considerable production costs and susceptibility to corrosion used.

at In this prior art, the object of the invention is to provide a composite pressure vessel of the type mentioned above so that the complex property guarantee of Brake air tanks like high tenacities even at low temperatures, high impact and breaking strength under dynamic load in the overpressure range of 8.5 to 20 bar, a long service life of at least 15 years despite constant load cycling and corrosion resistance is achieved.

These Task is performed by a pressure vessel with the characteristics of Claim 1 and by a method having the features of the claim 19 solved.

advantageous Embodiments of the pressure vessel and the method are the dependent claims.

The inventive solution draws characterized in that the shell and bottom of the pressure vessel in one for a more even and thus more risk-free distribution of the axial and radial stresses suitable Construction form is brought, which no longer consists of a cylindrical shell part and a spherical one Bottom part consists, but has the shape of an ellipsoid of revolution, whereby an extensive approach allows the ball shape becomes.

Of the liner body therefore has an approximate ellipsoidal body shape, so no sharp transitions between Floor and jacket area arise. Due to the largely uniform curvature in longitudinal direction the tank wall too in the original cylindrical mantle area, the tensile and radial stresses are very distributed evenly all wall areas and a stress concentration in the wall transition from the mantle to the ground is noticeably reduced.

A especially for the equalization of Tensile and compressive stresses suitable body shape is achieved when the ratio from the radius of the pole caps to the radius of the liner parts 1: 2.5 to 1: 5. The wall of the polar caps and the wall in the central region of the pressure vessel are evenly curved and merge seamlessly into each other.

The body shape of the ellipsoid of revolution is also coated in the application of the plastic Reinforcing layer of fiberglass tape and plastic sheath maintained on the liner, creating a pressure vessel, the first time with the taken over from the steel container construction cylindrical body shape breaks and is no longer comparable to the latter.

The Plastic coating of the fiberglass tape allows the glass fiber tapes with the liner and the juxtaposed or superimposed fiberglass ribbons during the Winding cohesively to connect with each other. It has been shown that especially with the laser welding the required high speeds when joining can be achieved. There so to speak the reinforcement welded on the liner can, the body shape formed from ball sections or the body shape of the ellipsoid of revolution even when reinforcing the liner easily be respected. The liner is suitably run with water, with the resulting heat dissipated becomes.

The pressure vessel according to the invention achieves an extremely high fatigue strength of well over 25,000 load changes, has a relation to the pressure vessels made of steel or containers with wound metal liners much lower weight, is executed by its insulating layer Envelope impact resistant, unbreakable and subject to no external corrosion. Due to the special shape of the envelope of the pressure vessel according to the invention receives a specific outer attachment structure, which makes it possible to continue to use existing on trucks, trucks, buses or rail vehicles fasteners for attachment.

The inventive method also allows the level of automation in manufacturing the pressure vessel through the use of modular tools and the integration of Testing Technology to increase significantly in the production process.

The produced by the method according to the invention pressure vessel have a repeatability of 100%, eliminating volume fluctuations occur in the air volume.

It is furthermore of particular advantage that in the wrapping type, Note and company signs can be introduced captive, so that the containers directly with product-specific test hammers according to the acceptance conditions can be provided being a separate, belated elaborate labeling of the container can be omitted.

Further Advantages and details will become apparent from the following description with reference to the attached Drawings.

The Invention will be explained in more detail below using an exemplary embodiment.

It shows

1 a pressure vessel according to the invention in sectional view,

2 a liner in section with injected sleeves,

3 one with a first reinforcing winding in the longitudinal direction of the liner body in a schematic representation,

4 a representation of the on the first reinforcing winding after 3 applied second reinforcing winding in the circumferential direction of the liner,

5 a liner with a third reinforcing winding made of plastic-coated fiberglass tape on the second layer in the jacket center region of the liner body in the circumferential direction in a schematic representation,

6 a reinforced with reinforcing layer, inserted in an injection mold liner for encapsulation with a cladding layer,

7a a representation of the enclosure with a fastening variant as a partial view,

7b a front view of the mounting variant according to 7a .

8a a further fastening variant molded into the envelope as a partial view,

8b a front view of the 8a and

9 a view of the connection sleeve in the pressure vessel.

The in 1 shown pressure vessel according to the invention 1 for a brake system, not shown, of a truck should have a capacity of 10 l and thus correspond to the nominal content of a pressure vessel made conventionally made of steel with cylindrical central portion and dished ends.

The pressure vessel 1 has an inner liner body 2 (please refer 2 ), which consists of two liner parts 3 and 4 composed of a multilayer, with the liner body 2 cohesively connected by welding reinforcing layer 5 and a serving 6 , The two liner parts 3 and 4 consist of polyethylene reinforced with short length glass fibers and are produced on a conventional injection molding machine in an injection mold. Each at their open ends 7 become the liner parts 3 and 4 connected by fusion welding material-tight and gas-tight. The connection sleeves 8th of the pressure vessel 1 are made
corrosion-resistant metal, such as brass, and are used in the injection molding of the polar caps 9 enclosed on all sides by the polyethylene except for the inner axial passage, so that the connection sleeves 8th captive and gas-tight in the center of the caps 9 are fixed.

The injection molds for the production of liner parts 3 and 4 are modular tools in which the volume can be correspondingly increased or decreased by core and jacket inserts ( 6 ). Thus, the liner parts according to the invention 3 and 4 in the usual diameter ranges for pressure vessels variable in length and thus variable in volume.

The forces occurring at internal pressure on the pressure vessel 1 Express themselves in axial and tangential stresses, which overlap each other at each point of the container wall and occur as the resulting stress. Optimum container dimensions ments are reached when each point of the container wall receives the same resulting stresses.

Container off metallic materials or containers with sharp transitions (strong curvatures) from the coat do not meet these requirements, so that straight High resulting stresses occur in these areas regularly to Leakage of the pressure vessel at high alternating loads.

The polar ice caps 9 and the middle cladding region 10 of the liner body 2 the pressure vessel according to the invention 1 have the shape of a body formed of spherical sections or of an ellipsoid of revolution 11 (please refer 2 ), with the polar caps 7 are formed approximately hemispherical and transitionless in the cladding region 10 pass. The pressure vessel 1 gets a bulbous design (see 1 ).

The radius RP of the pole cap 7 is in the example presented 103.3 mm, the radius RM of the shell region 302.3 mm, so that a ratio of the two radii to each other of 1: 2.92 results. With this ratio, the pressure vessel according to the invention reaches 1 an optimum between the force relationships underlying the dimensioning and the stress conditions.

The multi-layer reinforcing layer 5 consists of a fiberglass tape 12 with a sheath 13 made of polyethylene.

While wrapping the liner body 2 with the first tangential winding layer A (see 3 ) of the fiberglass tape becomes the plastic jacket 13 made of polyethylene by laser, electric arc or similar heated, locally melted and with the surface of the liner body 2 welded, so that liner body 2 and the first winding layer A form a cohesive unit. The following second and third winding layers B and C of the glass fiber tape 12 is also applied so that the side by side and overlying edges of the tape 12 be welded together. The applied reinforcement layer 5 thereby also receives the body shape of the previously described ball sections or the ellipsoid of revolution 11 (please refer 4 and 5 ).

On the multi-layer reinforcing layer 5 follows the coating applied by injection molding 6 , which consists of a short glass fibers contained polyethylene. The polyethylene can also be mixed with propellants. The serving 6 secures the reinforcing layer 5 in their function and is at the same time designed as a protective layer, wherein in the case of an additive with propellants and an insulation is achieved. Into the serving 6 Either fasteners are integrated or the enclosure 6 is itself to a specific fastener 14 formed (see 7a and 7b and 8a and 8b ). This fastener 14 Accordingly, it can be designed so that the hitherto conventional fastening by means of straps ( 7a and 7b ) or by a direct screw connection ( 8a and 8b ) he follows.

Appropriate signs, nameplates, company logos or other names or labels can be prefabricated and captive in the envelope 6 be introduced. This also provides the opportunity to provide the signs or nameplates or other names with digital information carriers whose information can be read and retrieved by a corresponding RFID configuration.

The 9 shows that by molding with plastic in the polar cap 7 of the liner body 2 fixed connection sleeve 8th made of metal, for example brass. On the connection sleeve 8th act as a result of the internal pressure in the pressure vessel 1 or liner body 2 Shear forces trying the connection sleeve 8th to push out of the plastic composite. When screwing or unscrewing plugs or screw plugs into the connection sleeve 8th Circumferential forces are created, trying the connection sleeve 8th to unscrew from the plastic composite.

Finally, in the operating state of the pressure vessel, a constantly increasing and decreasing force acts on the connection sleeve 8th one.

So that all these forces can be absorbed without the connection between connection sleeve 8th and plastic composite is impaired, has the connection sleeve 8th a flange 15 and a sufficiently long cylindrical part 16 in which to increase the shear surface grooves, recesses and heels 17 are introduced. This allows a positive connection between the connection sleeve 8th and the plastic composite with sufficiently high shear resistance.

Over the entire cylindrical part 16 the connection sleeve 8th is a fine-toothed knurling 18 present, which is able to absorb both circumferential forces and shear forces in a sufficient size.

To ensure a permanently tight connection between connection sleeve 8th and plastic composite, acts under internal pressure load a contact force of the plastic composite on the cylindrical part 16 the connection sleeve 8th due to leverage over the puncture 17 the connection sleeve 8th , The connection sleeve 8th is inside with a turnout 19 provided in which an injected plastic lip 20 the liner wall 21 of the respective liner part 3 . 4 protrudes.

Due to the constantly prevailing internal pressure in the operating state, a contact force of the lip acts on the metal inner surface, which increases the more, the higher the internal pressure rises. The in the scope of the connection sleeve 8th introduced knurls 18 , Punctures and heels 17 In addition, they increase the surface area by up to 80%, so that the contact surfaces between metal and plastic, which are decisive for the tightness, increase considerably and the tightness is ensured.

The preparation of the invention, from the layers of the liner body 2 , Connection sleeves 8th , Armierungsschicht 5 and serving 6 existing pressure vessel will be described in detail below.

The liners 3 and 4 are sprayed on a conventional injection molding machine, so that a more detailed description is dispensable.

starting material for the Spraying the liner body is a plastic granulate made of polyethylene, which is a short fiber content compounded or as a pure admixture with a proportion of up to 30% by weight is added.

The injection molding tools used are modular tools, which are designed so that always two congruent liner parts 3 and 4 can be produced. The core and dome of the tools are equipped with disc-shaped, coolable segments, which allow the active elements to be lengthened or shortened in the respective diameter range. For each container diameter, only one tool is required. The coolable segments are replaced accordingly in pairs in the injection mold. The built-in parts and connecting sleeves are inserted and molded with known handling devices in the injection mold.

The Injection of the plastic melt is always via a hot runner nozzle on the front side of the liner parts. The hot runner nozzle has 12 star-shaped distribution channels, the the plastic melt in the linear and radial direction with the Distribute the effect of partial fiber orientation evenly in the direction of flow. By this measure elevated The compressive strength of the liner body considerably.

The injection-molded liners 3 and 4 are then connected together cohesively. This happens because the front sides 7 the liner parts 3 and 4 aligned with each other and welded together by means of mirror welding. It is understood that the welding parameters are matched according to the selected plastic mixture and other suitable joining methods are covered by the invention.

After welding, the attached liner body becomes 2 tested for gas tightness, in which the liner body 2 spent in water, submerged and exposed to air at a test pressure of 2.5 bar. Existing leaks are caused by the liner body 2 rising air bubbles displayed. The gas-tightness test is preceded by a safety test in which the liner body is pressed under air with a hermetic shielding at a test pressure of 3.5. This pressure is then reduced to 2.5 bar on the leakage tester mentioned at the beginning.

Of the Safety and leak tester is a complex assembly, in addition is equipped with a drying device for drying the liner body. The operation of this complex test bench is only authorized Staff reserved that over the appropriate approvals for pressure vessel etc. features.

In the following process step, the previously tested for safety and tightness liner body 2 Bubble-free filled with an incompressible medium such as water and the connection sleeves 8th sealed with sealing stopper liquid-tight. This medium stabilizes the liner body, safely absorbs the heat introduced in the process steps described in more detail below and thus at the same time serves as a coolant.

If plastics with a higher melting point are to be used, filler valves are used in the connection sleeves, which ensure that the incompressible medium is kept under pressure in the circulation through the liner body 2 can be driven.

The sealing plugs are provided with a conical pin for clamping and securing the liner body 2 serve in centered position of the winding machine.

When Wrapping material come from polyethylene-encased continuous glass fibers used, which sintered into a strip with rectangular cross-section are. Instead of polyethylene but also polypropylene or another suitable thermoplastic can be used. Other thermoplastics are also suitable.

The reinforcement of the liner body 2 will with the application of a first winding layer A of a plastic-coated fiberglass tape 12 started to absorb the axial stresses while recording the radial stresses. The winding layer A is wound at an angle of 55 ° to the longitudinal axis and also serves to reinforce the pole caps of the pressure vessel.

The Winding layer A is during of the winding heated by laser, the plastic sheath melted and the edges the individual layers welded together and on the liner body.

The voltage peaks as a result of axial and radial stresses regularly occur in the middle cladding area. Therefore, in the next step in the middle of the mantle area 10 of the liner body 2 first applied a second winding layer C as a circumferential winding on the first layer.

The Winding width B1 of the winding layer C is of container length L and the container diameter D dependent.

B

Wickelbreite

L

Behälterlänge

D

Behälterdurchmesser.

For the second winding layer C, the relationship applies: B1 = 0.6L - 0.1D, where:

B

winding width

L

container length

D

Container diameter.

While winding the liner body 2 with the second winding layer, the latter is again heated by laser, melted and with the liner body 2 cohesively welded. It creates an intimate connection between the first and second position.

in the next Step is on the second winding layer C, a third winding layer E wound up. The winding layer E is used in conjunction with the winding layer C. a more even one Radial stress distribution and forms a belt layer in the middle layer area.

B

Wickelbreite

L

Behälterlänge

D

Behälterdurchmesser.

For the layer width of the third winding layer E, the following applies: B2 = 0.3 L - 0.1 D, where:

B

winding width

L

container length

D

Container diameter.

The third winding layer E is again during the wrapping means Laser heated, the plastic sheath melted and the next to each other coming edges of the glass fiber tape together welded, including the underlying second layer with the overlying layer welded becomes. The second winding layer C and the third winding layer E are thus cohesively connected with each other.

The media filling remains in the finished armored liner body 2 as well as the sealing plugs in the connecting sleeves 8th , This state is in the following encapsulation of the armored liner body 2 maintained.

The encapsulation of the armored liner body 2 takes place in a separate, suitably prepared injection mold in the interaction of an adapted Spritzgießformgestaltung and a suitable plastic and the pressure build-up of the spray medium.

The injection mold is equipped with several sprue distribution channels, the one simultaneous filling the cavities between shape and inserted reinforced liner body allow. The sprues are distributed in Polkappen- and coat area. The gating takes place machine side at the same time at the poles through a round film gate, in the hot runner balanced.

The reinforced liner body filled with the incompressible medium 2 is inserted into the opened injection mold and centered on the conical approaches of the closure plug and firmly clamped when closing the mold, after the internal pressure of the filling medium in the liner body 2 was set to about 8 to 10 bar at a temperature of 10 to 15 ° C.

In this position forms the armored liner body 2 the core that gets overmoulded. By increasing the internal pressure to about 8 to 10 bar and further technological product-specific parameters, changes in position and local deformation of the core can be avoided by the considerable force effects during the injection process.

Starting material for the production of the envelope is a plastic granules of polyethylene, to which a short fiber content to increase the strength and a blowing agent for foaming, for example, in each case compounded or added as a pure admixture. This allows desired strength properties of the envelope, for example, for the integration of appropriate fasteners in the envelope, and at the same time desired insulation properties of the envelope, for example, for damping sudden shocks, he to pass.

The Polyethylene can also be further modified by the addition of colorants colored be omitted so that a corresponding color of the pressure vessel can and in addition a color coding according to the technical field of application of the pressure vessel easily possible becomes.

In the injection mold are replaceable punches for the application of Inscriptions incorporated, which then raised on the container surface or deepened. This allows according to the customer's request Company names, type plate inscriptions, information signs, approval marks, Logos and similar applied. Labels, pictures or information signs, approvals let's go over it also insert in the form of films in the injection mold, by means of vacuum Fix in a suitable position and melt inextricably during injection with the enclosure. This also allows these slides with digital media to provided with the relevant technical data, registration information stored etc. and are retrievable by means of RFID technology.

The complex Sticking or welding on The company signs can be omitted.

to warranty a continuous flowability and a uniform all-round mold filling the injection mold with a temperature of 80 ° C driven. In the example shown here the injection rate was 15 mm / s, the injection pressure was <40 bar, the holding pressure at 15 bar, the intrusion at 4-6 s and the cooling time at 120 s.

The so by the method according to the invention manufactured pressure vessel with a nominal capacity of 10 L reached a bursting pressure of 50 up to 60 bar without splinter effect, a load cycle resistance of more than 25,000 load cycles, giving a lifespan of about 20 years equivalent.

1

pressure vessel

2

liner body

3, 4

liner parts

5

reinforcing layer

6

wrapping

7

Front side of 3 . 4

8th

coupling bush

9

ice caps

10

middle cladding region

11

Rotationsellipsoid

12

fiberglass tape

13

Sheathing of 12

14

fastener

15

Flange of 8th

16

Cylindrical part of 8th

17

grooves

18

knurling

19

recess

20

Plastic lip

21

Linerwandung

A

First wrapping location

C

Second wrapping location

D

diameter of the container

e

third wrapping location

L

Length of the container

RP

radius polar cap

RM

radius coat

Claims (31)

Pressure vessel ( 1 ) A) of plastic, in particular compressed air tank for brake power systems and pneumatic auxiliary equipment on trucks, trucks, buses, rail vehicles or fire extinguishing systems, B) is formed as a multi-layer molded body, comprising C) one of injection molded, made of linear parts ( 3 . 4 ) D) of fiber-reinforced polyethylene, polypropylene or polyamide, E) assembled liner body ( 2 ) F) with a middle cladding region ( 10 ) and G) polar caps ( 9 ), H) wherein in the polar caps ( 9 ) Connection sleeves ( 8th ) are formed captive, I) one on the liner body ( 2 ) arranged reinforcing layer ( 5 ) of fiberglass tape and J) one on the reinforcing layer ( 5 ) arranged injection-molded captive enclosure ( 6 ) K) made of fiber-reinforced polyethylene, polypropylene or polyamide, L) the pressure vessel ( 1 ) has the form of a body composed of spherical sections or an ellipsoid of revolution ( 11 ), M) where the ratio of the radius (RP) of the polar caps ( 9 ) to the radius (RM) of the middle cladding region (FIG. 10 ) Is 1: 2.5 to 1: 5, N) and where the polar caps ( 9 ) and the middle cladding region ( 10 ) merge seamlessly under the same curvature. Pressure vessel according to claim 1, characterized in that the liner body ( 2 ) is reinforced with up to 30% proportion of glass fibers. pressure vessel according to claim 1 and 2, characterized in that the glass fibers consist of short fibers. Pressure vessel according to claim 1 to 3, characterized in that the liner parts ( 3 . 4 ) of the liner body ( 2 ) at their mutually facing end faces ( 7 ) are cohesively connected to each other. Pressure vessel according to claim 1, characterized in that the reinforcing layer ( 5 ) made of a plastic-coated fiberglass tape ( 12 ), which is on the liner body ( 2 ) is arranged in the composite so that the enveloping plastic of the glass fiber ribbon by heating by means of laser, arc or open flame is an intimate positive and cohesive connection of the entire composite. Pressure vessel according to claim 5, characterized in that the plastic casing ( 13 ) of the fiberglass tape of the reinforcing layer ( 5 ) consists of polyethylene, polypropylene or polyamide. Pressure vessel according to claim 1, characterized in that the envelope ( 6 ) at the same time forms a protective layer which forms the reinforcing layer ( 5 ) additionally secured. Pressure vessel according to claim 7, characterized in that the envelope ( 6 ) is additionally formed as an insulating layer. Pressure vessel according to claim 7, characterized in that the envelope ( 6 ) as an outer fastener ( 14 ) is designed to receive fasteners of lorries, trucks, buses, rolling stock or fire-extinguishing systems which are placed in or on the envelope ( 6 ) are integrally formed or integrally formed. Pressure vessel according to claim 7, characterized in that in the envelope ( 6 ) Inserts for nameplates, signs, labels, company signs are captive introduced. pressure vessel according to claim 10, characterized in that the inserts a digital information carrier contain. Pressure vessel according to claim 7, characterized in that in the envelope ( 6 ) Are added colorants that ensure a color coding of the shell according to the operating conditions. Pressure vessel according to claim 1, characterized in that in the centers of the polar caps ( 9 ) molded connection sleeves ( 8th ) made of metal, for example aluminum, copper, brass, titanium, tombac, which except for their outer contact surface and the internal thread of the plastic of the liner body ( 2 ) are enclosed. Pressure vessel according to claim 1 and 13, characterized in that the connection sleeves ( 8th ) inside each one turn ( 19 ) into which a plastic lip ( 20 ) of the liner body ( 2 protruding, wherein the lip is pressed sealingly against the Ausdrehfläche by the internal pressure acting in the interior of the liner body. Pressure vessel according to claim 1 and 13, characterized in that the connection sleeves ( 8th ) each have a flange ( 15 ) and a sufficiently long cylindrical part ( 16 ), the outside with grooves, punctures and paragraphs ( 17 ) is provided to increase the shear surface. Pressure vessel according to claim 15, characterized in that the cylindrical part ( 16 ) each connection sleeve ( 8th ) also a fine-toothed knurling ( 18 ) for receiving circumferential forces and shear forces. pressure vessel according to claim 1 and 13, characterized in that the connection sleeves as a one piece Multiple manifolds are formed. Pressure vessel according to claim 1 and 13, characterized in that each connection sleeve ( 8th ) has an internal thread into which a filling valve is inserted. A method for producing a pressure vessel aa) made of plastic, in particular compressed air tank for brake systems and pneumatic auxiliary equipment on trucks, trucks, buses, rail vehicles or fire extinguishing systems, bb) in the first liner parts cc) with hemispherical pole caps dd) made of glass fiber reinforced polyethylene, polypropylene or Polyamide granules ee) are molded by injection molding in an injection mold, ff) in the center of the polar caps gg) introduced connection sleeves are surrounded by plastic, hh) the liner parts are joined together by joining in a joining machine to a liner body, ii) the attached liner body with a Reinforcing layer of glass fibers jj) is wound in the cross-bond in a winding machine and kk) the thus-reinforced liner body with a sheathing of fiber-reinforced polyethylene, polypropylene or polyamide ll) is encapsulated, characterized in that mm) the pressure vessel ( 1 ) has the shape of a body composed of spherical segments or is an ellipsoid of revolution and a central shell area ( 10 ), wherein the ratio of the radius (RP) of the pole caps ( 9 ) to the radius (RM) of the middle cladding region (FIG. 10 ) Is 1: 2.5 to 1: 5, and the pressure body ( 1 ) in the work steps, oo) spraying the liner parts ( 3 . 4 ), pp) connecting the liner parts ( 3 . 4 ), qq) welding on the reinforcing layers during winding on the liner body ( 2 ) and rr) encapsulating the armored liner body ( 2 ) is formed. Method according to claim 19, marked through the following steps: a) produce congruent Liner parts of the liner body by a uniform distribution the plastic melt with a short fiber content of up to 30% in the plastic in the axial and radial direction under partial Alignment of the fibers in the flow direction the melt and in compliance with the specified short fiber content, b) material coherent Joining or Glue the end faces of the liner parts to a closed, hollow liner body with adjustment to the plastic mixture after step a) coordinated joining or adhesive parameters, c) pressing the liner body with Air for safety inspection and leak test of the aerated liner body under water and then drying the liner body, d) Stabilizing the liner body by a bubble-free filling with an incompressible medium, applying this medium with an overpressure from 8 to 10 bar and closing the connection sleeves of the liner body to the subsequent Reinforcing the liner body, e) Reinforcing the liner body by wrapping with several layers of plastic-coated fiberglass tape, wherein the layers of the glass fiber ribbon by melting the enveloping Plastic interconnected cohesively, f) Inject molding in the injection mold inserted liner body from the polar caps of fiber-reinforced Plastic at an injection pressure of <40 bar to form a captive Serving up the reinforcement of the liner body. Method according to claims 19 and 20, characterized that the temperature resistance of the liner body in the range of -40 ° C to + 80 ° C by a Admixing a polypropylene copolymer granules is adjusted to the polypropylene granules in a weight ratio of at least 1: 3. Method according to claim 20, characterized in that that as a joining method after step b) a mirror welding, hot gas welding, heating element welding, Heizradrahiderstandsschweißen or injection welding is used. Method according to claims 19 and 20, characterized that the liner body with an air pressure of 3.5 bar in a hermetic enclosed space according to step c) pressed and subsequently after lowering the overpressure to 2.5 bar in water for leaks. Method according to claims 19 and 20, characterized that water, oil or mixtures thereof as an incompressible medium for stabilization of the liner body is used, wherein the medium is maintained under an overpressure of 8 to 10 bar becomes. A method according to claim 19 to 24, characterized in that the filled with medium liner body after its insertion, centering and clamping in the winding machine in the following individual steps after step e) is reinforced: e1) winding the jacket and the pole caps of the liner body with a first layer made of plastic coated fiberglass tape to accommodate axial and radial stresses and reinforcing the pole caps while simultaneously melting and fusing the sheath for cohesive bonding with each other and with the liner body; e2) winding the first layer according to e1) in the middle cladding region for receiving voltage peaks from axial and radial stresses while simultaneously melting and fusing the plastic surfaces of the juxtaposed fiberglass strip with a second layer in a winding width, the condition B1 = 0.6 L - D is sufficient, where E3) winding of the second layer in the middle cladding region to equalize the radial stress with simultaneous fusion of the plastic surfaces of the juxtaposed fiberglass strip with a third layer in a winding width, which is the winding width, L is the winding length and D is the diameter of the liner body Condition B2 = 0.3 L - 0.1 D is sufficient, where B is the winding width, L is the winding length and D is the diameter of the liner body. Method according to claim 25, characterized in that that for melting the plastic surfaces of the Glafaserbandes and of the liner body a laser, arc or gas burner heat source is used, wherein the incompressible medium at the same time as a coolant against deformation of the liner body is used. Method according to claim 26, characterized in that that the incompressible medium and coolant remain in the liner body or by a filling valve located in a threaded connection under overpressure kept and constantly is added and removed. Method according to claims 19 and 20, characterized that filled with medium, after step e) reinforced liner body in the injection mold spent, centered and closing plugs on the connection sleeves is clamped and wrapped in the following individual steps according to step f): f1) Increase the internal pressure in the liner body by applying the incompressible medium to 8 to 10 bar through a filling valve located in a threaded plug and adjusting the Temperature of the filling medium at 10 to 15 ° C, f2) optional insertion of company nameplates, nameplates, approval marks etc. on the armored surface the liner body, f3) Tempering the injected and distributed plastic melt at least 180 ° C and subsequent Cool below the solidification temperature of the plastic mixture, f4) Hold at a holding pressure of about 15 bar to solidify the envelope, f5) Remove the pressure vessel and its emptying. Method according to Claim 28, characterized that the optionally inserted nameplates contain digital information carriers. Method according to claim 19, characterized that the fiber reinforced Plastic Dyes to mark the envelope according to the operating conditions of the pressure vessel be added. Method according to claim 20, characterized in that that serving Be added blowing agent for the production of an insulating layer.