DE102012223676A1 - Pressure tank for storing pressurized fluid, used in motor car, has carrier arranged between tank chambers, which receive internal pressure forces acting on covering and stabilize oval shape - Google Patents

Abstract

The pressure tank (100) has an oval-cylindrical casing (180) and two lids (230,230') arranged at the ends of the casing. The two tank chambers (130,130') are arranged in the inner tank (120) which is surrounded by a covering (110) made of a fiber-reinforced plastic composite. The two tank chambers arranged in the longitudinal direction (150), are connected hydraulically by a terminal connection portion (220). A carrier (190) is arranged between the tank chambers, so as to receive the internal pressure forces acting on the covering and to stabilize the oval shape.

Description

The invention relates to a pressure tank for receiving pressurized fluids, in particular for motor vehicles.

From the DE 60207082 T2 a pressure tank is known as a fuel tank for motor vehicles, which has a metallic inner tank and formed as a fiber-plastic composite sheath. The cylindrical inner tank has two terminal, convex, in particular hemispherical, lid, which are each equipped with a connection. In this case, the metallic inner tank essentially produces the pressure-tightness, while the shell formed as a fiber-plastic composite ensures the stability of the pressure tank against an operating pressure of 200 bar. As the matrix for the fiber-plastic composite, epoxy resin is used, and as the fibers, carbon fibers and, for example, metal fibers, mineral fibers or synthetic fibers may be preferably used.

From the WO 2012 100 923 A1 For example, a hydrocarbon storage tank is known which has a circular-cylindrical inner tank made of polyolefins and a fiber-reinforced casing. In this case, the fiber-reinforced sheath on a plastic film, which has a very low permeability to hydrocarbons.

The compressed gas tank of EP 1034395 B1 has at least one chamber which can be equipped with the pressurized fluid. The chamber is penetrated by one or more spindles, can be used in the fasteners to hold the chamber in pressurization in the form. In this case, a spindle means a passage within the chamber, which passes through the chamber and consists of the material of the chamber walls, wherein the chamber is sealed off from the passage pressure-tight.

Also, due to the increasing use of motor vehicles, which are operated with combustible gases or gas mixtures, the demand for pressure tanks increases, with which the gaseous fuel in sufficient quantity, for example, can be stored in a motor vehicle. However, the usually used circular cylindrical embodiment of such pressure tanks does not always match the structural conditions of the respective application, so that increasingly flatter designs are desired. In addition, in the case of gas cylinder-shaped embodiments, the valve devices for refueling of such pressure tanks, which may be under a very high pressure, exposed. For example, in the case of an accident of a motor vehicle with such a pressure tank, the valve devices can be knocked off. In addition, the pressure tanks are usually made primarily of metal or at least have metal, so that these pressure tanks have relatively high weight due to the metallic portion.

The present invention is now concerned with the problem of developing a pressure vessel for an improved embodiment, which is characterized in particular by a flatter design with high strength against the internal pressure and by a low weight and also a higher reliability, especially in an accident, having.

According to the invention, the object is achieved by a pressure tank for receiving pressurized fluids, in particular for motor vehicles, with an oval-cylindrically shaped body in the outer shape and with two end-mounted lids, the body having a, at least two tank chambers, inner tank and a the at least two tank chambers in the circumferential direction surrounding sheathing of a fiber-plastic composite, wherein the at least two tank chambers are arranged in the longitudinal direction substantially parallel to each other. In addition, the at least two tank chambers are connected to each other via a terminal connecting portion with respect to their interior space. That is, this creates a common fluid storage space. As the terminal connection portion, a connection is considered, which is arranged in the terminal quarter of the length of the tank chambers. It can also be arranged quite advantageous at the very end of the tank chambers. Between the at least two tank chambers, a carrier is used as a separate component, which is connected to the casing so that it can absorb internal pressure forces acting on the casing, and stabilize the oval shape.

The body is oval in the circumferential direction. Advantageously, a flatter shape of the pressure tank can be produced by the inner tank, which is composed of two tank chambers. Thus, by means of such a pressure tank advantageous consideration to the structural conditions in, for example. A motor vehicle are taken and the flat shape can be adjusted by a corresponding design of the at least two tank chambers to the available height. In this case, advantageously, the inner tank made of a structurally weaker material, for example, can be produced inexpensively by means of a blow molding of plastic. It is possible that the inner tank or the at least two tank chambers are made of a material which is sealed against the fluid to be stored. It is also conceivable that the inner tank or the at least two tank chambers equipped with an inner coating which has a very low permeability to fluid to be stored. As fluids can, for example, natural gas, hydrocarbons, hydrocarbon mixtures, hydrogen, etc. be used.

In this embodiment of a pressure tank, the casing of a fiber-plastic composite produces the necessary stability, which prevents the inner tank, which is unstable against high pressures alone, from bursting, or the tank being over-deformed and thus becoming leaky. It ensures that the desired oval shape of the pressure tank is maintained. Thus, the pressure tank for the high pressures of 100 to 700 bar is suitable. On the terminal sides of the body lid are preferably provided which close the oval opening. The side covers may also, like the jacket, exert a stabilizing action on the inner tank.

The longitudinal direction is to be understood as the direction in the longitudinal axis of the pressure tank or in the direction of the longitudinal axes of the two tank chambers. The transverse direction is arranged perpendicular to the longitudinal direction and running in sequence of at least two tank chambers. The z-direction is perpendicular to each of the longitudinal direction and the transverse direction and represents the direction of the smallest dimension of the pressure tank. The circumferential direction means the direction perpendicular to the longitudinal direction at the periphery of the pressure tank. Under terminal or terminal side are the two areas or sides of the pressure tank, the body, the two tank chambers or the inner tank to understand that limit the respective component in the longitudinal direction. Under an oval-cylindrical shape is a plane-parallel shape with a rounded, but non-circular base to understand. Radially different radii may occur, as is the case, for example, with an ellipsoidal shape.

A fiber-plastic composite consists essentially of at least one single- or multi-layered fiber structure which is embedded in a plastic matrix. In this case, the at least fiber structure is surrounded by the plastic matrix. The materials used for fiber structures may preferably be glass fibers, carbon fibers or aramid fibers. The fibers may be in the form of continuous fibers, long or short fibers, yarns, fiber bundles, rovings or ribbons. The fibrous structure may be formed as a winding, preferably also as a multilayer, as one or more unidirectional or multiaxial layers, as a woven or laid fabric or as a mixed form thereof. The materials used for the matrix are plastics, preferably thermosets, thermoplastics, elastomers, epoxy resins or other resins. The matrix may also contain fillers or additives. Particularly preferred is the sheath made of CFRP (carbon fiber reinforced plastic). Furthermore, the main fiber direction of the fiber structure of the sheath is advantageously aligned predominantly in the circumferential direction, as is the case for example during winding.

It is also conceivable that the inner tank not only from two tank chambers, but from several tank chambers, which are also arranged in parallel in the longitudinal direction and possibly in a plane. Always two tank chambers can be hydraulically connected to each other via a terminal connection section. In this case, the terminal connecting portions may be arranged on the terminal sides alternately or always on the same side. Preferably, the embodiment with two tank chambers, but it is also conceivable that the inner tank of three, four, or more tank chambers is constructed.

If the at least two tank chambers and the terminal connection section are integrally formed, the inner tank can be produced in a process or step, for example by means of a blow molding process from plastic. Consequently occurring leakage points, for example, as they may occur during welding or gluing, are therefore unlikely and thus, due to the one-piece or integral training, can be saved on a procedural steps, the inner tank can be made faster and on the other hand, the Committee can be minimized. In addition, the terminal connecting portion can be produced reproducibly in the desired shape, so that the connecting cross section between the at least two tank chambers can be formed in a defined form.

The terminal connection section can advantageously also be connected to the two tank chambers in a material-locking manner, e.g. glued or welded. This makes it easier to first produce the individual tank chambers.

The carrier extends parallel to the longitudinal direction of the body. If a double-T carrier or a similarly shaped carrier is inserted between at least two tank chambers, an enlarged flange surface is available on the upper and lower sides for connection to the sheathing. As a result, the stability of the pressure tank, in particular with respect to the ovalization forces caused by the internal pressure, can be further improved. The sheath is applied so that it is connected to the flange surfaces of the carrier. The connection can in particular be cohesively, e.g. glued, welded.

It is also conceivable that in more than two tank chambers, between each two tank chambers a carrier, for example a double-T carrier is used. These additional carriers fulfill in a similar manner a stabilizing effect on the oval shape.

After the jacket has been formed, it can additionally be connected to fastening elements, such as, for example, screws, rivets, bolts or the like, and fixed to the same, so that detachment of the jacket from the carrier can be prevented or at least reduced.

Furthermore, the carrier may have a terminal recess in which the terminal connection portion is inserted. Advantageously, due to the recess of the carrier can be inserted and positioned between the tank chambers so that the connecting portion is at least partially surrounded by the double-T-carrier and the carrier can conclude flush with corresponding terminal embodiment with the terminal side of the tank chambers. As a result, the stabilizing effect of the carrier may extend beyond the connecting portion and is not limited by the same. On the other hand, the surrounding support protects the connecting portion from external forces during assembly of the components, not only during assembly but also during operation of the pressure tank.

The support may be made of metal, of a highly stable, dimensionally stable plastic of a metal alloy, aluminum, an aluminum alloy or preferably substantially in the form of a fiber-plastic composite, in particular of CFRP. Advantageously, when using lightweight materials, such as a fiber-plastic composite or aluminum or an aluminum alloy, the weight of the pressure tank can be significantly reduced with comparable stability of the double-T-carrier.

If at least one tank chamber in a region adjoining the double-T carrier is designed to be complementary to the double-T carrier, the double-T carrier can advantageously be positioned precisely between the tank chambers. If, in this case, the inner tank or the tank chambers are designed to be pressure-tight, the gap between the inner tank and the double-T beam does not have to be filled, since the two surfaces are complementary to each other.

Due to the double T-shape of the double-T-carrier can surround the respective tank chambers in the adjacent area with its flange so that due to the surrounding arrangement of the double-T-carrier acts stabilizing on the tank chambers in z-direction. As a result, the tank chambers can be supported on the flange surfaces of the double T-beam, and thereby deviation from the oval shape due to the internal pressure can be reduced or prevented.

Preferably, the tank chambers are formed in an oval, not adjacent to the double-T-carrier area, so can be given by the corresponding shape of the tank chambers an overall oval shape of the pressure tank.

In more than two tank chambers, the tank chamber, which is arranged between two tank chambers or between two double-T-carriers may be formed without an oval shape, since such an internal tank chamber rests from two sides on a double-T-carrier. In this case, a substantially square or rectangular shape can optionally be used with rounded edges, wherein in this case as well, a complementary design in the adjacent regions to the double-T-carrier is conceivable and preferred.

The lids close in particular the oval openings of the body. They may be designed as oval discs optionally with curvature and preferably curved concave inwards. The lids can also be made of fiber-plastic composite or metal, as well as of plastics, which have high strength and stability.

If at least one terminally arranged cover has a concave design, a tank chamber concave on at least one end side or a similar inner tank can be stabilized by means of such a cover. In this case, a concavity is understood to mean a concavity in the direction of the interior of the tank chamber. As a result, on the one hand, the stability to the internal pressure can be improved compared to the conventional convex or disc-shaped lids and, on the other hand, due to the internal camber, an area can be created which is less exposed and more protection or even space e.g. offers for a valve device.

It is also conceivable that at least one tank chamber is concave on both end sides. Furthermore, it is conceivable that all tank chambers or the entire inner tank are concave on both end sides. The concave design of the tank chambers or the inner tank is preferably designed so that the shape of the terminal side surface is adapted to that of the respective lid, particularly preferably so that as large a part of the side surface abuts the lid and is supported by this.

If the carrier is concave at least on one terminal side, the carrier can be flush with the inner tank at this terminal side, with the concave configuration of the two tank chambers, so that stabilization by the carrier also takes effect in the edge region.

If the pressure tank has at least one reinforcement running in the circumferential direction in the terminal area, it is advantageously possible for the lid to be connected more stably to the casing, and secondly the pressure tank is better protected against impacts in the edge region. This can be especially important in a terminally concave embodiment of the pressure tank or the lid, since the tapered edges of the lid and sheathing are particularly susceptible to damage in shock. In addition, the body is particularly dimensionally stable due to the reinforcement in the area of the lid. The lid can be supported on the reinforcement, which in turn is preferably connected to the jacket cohesively. Preferably, the reinforcements are also made of a fiber-plastic composite, in particular CFRP. The fiber main direction of the fiber structure can advantageously be oriented predominantly in the circumferential direction, as is the case for example during winding. And preferably, the reinforcement is provided on the outside of the sheath. In particular, reinforcement is provided annularly in the circumferential direction at both terminal sides of the pressure tank.

If at least one cover has a valve device, then the pressure tank can advantageously be refueled via such a valve device during operation or fuel can be taken from the pressure tank via such a valve device. Since the cover usually has to be used as a separate component after the body has been formed, with the arrangement of the valve device on the cover, the production of the body can be simplified and its stabilizing effect structurally obtained. It is conceivable that both covers of the pressure tank have such a valve device. In addition, if the cover is concave, the valve device can be mounted in the middle region of the cover in such a way that it is surrounded by the cover or the covering in a protective manner and thus protected against external forces. As a result, it is advantageously possible to ensure operational safety even in the event of damage, for example in the event of an accident of the motor vehicle.

Furthermore, the valve device can be arranged in the region of the terminal connection section, wherein the valve device can be designed such that it is fluidically connected to the terminal connection section. Advantageously, in this case, the fluidic connection can be interrupted by the valve device via the terminal connection section between the tank chambers, so that the respective tank chamber refueled separately and can be removed separately from the respective tank chamber fluid.

Furthermore, at least two or more of the following components may be glued or welded together: the sheath, the inner tank, a tank chamber, the carrier, the reinforcement, the lid or the valve device.

If, for example, the carrier is designed to be flush with the respective tank chambers or the inner tank, then the lid can be bonded both to the inner tank and to the carrier. If the respective lid is glued to the carrier, then in addition to the reinforcement and the carrier can hold the lid in position and counteract the internal pressure of the tank chambers.

Furthermore, the valve device can be glued to the lid, whereby a very simple and quickly produced connection between the valve direction and the lid is possible. Furthermore, the tank chambers can be glued to the carrier. The adhesive acts between the carrier and the tank chambers not only as a fixation, but at the same time as a filling material, the cavities filled, so that the inner tank is not damaged by inflating the material of the inner tank into the cavities when applying internal pressure.

The pressure tank can be designed for an internal pressure of up to 100 MPa.

The following figures show embodiments according to the invention, with further advantageous features, which can also be combined individually with each other. It show, each schematically:

1 a pressure tank,

2 an inner tank with retractable double T-beam,

3 a pressure tank with a valve device used in a concave cover in the lateral cross-section.

As in 1 shown, points the pressure tank 100 a sheath 110 on, which is designed as a fiber-plastic composite. The jacket 110 surrounds an inner tank 120 that has at least two tank chambers 130 . 130 ' is formed. It surrounds the jacket 110 that have at least two tank chambers 130 . 130 ' in the circumferential direction 140 so that an overall oval shape of the pressure tank 100 arises. Here are the two tank chambers 130 . 130 ' in the longitudinal direction 150 of the pressure tank 100 arranged substantially parallel, so that the pressure tank in the transverse direction 160 is greater than in the z-direction 170 , The resulting oval or flat design can be used advantageously especially in motor vehicles with a correspondingly narrow dimensioned space. The two tank chambers 130 . 130 ' are over a terminal connection section 220 hydraulically connected to each other so that they form a connected internal volume for storing the fluid. This form the jacket 110 and the inner tank 120 a body 180 of the pressure tank 100 ,

In addition, between the two tank chambers 130 . 130 be used a double-T-carrier, where the two tank chambers 130 . 130 ' abutment and the with its flange surfaces 200 . 200 ' the respective tank chambers 130 . 130 ' at least partially surrounds. These flange surfaces 200 . 200 ' have a stabilizing effect on the shape of the tank chambers 130 . 130 ' and prevent bulges of the body even when applying the internal pressure 180 in the area of the flange surfaces 200 . 200 ' , In this case, the double-T-carrier 190 a recess 210 exhibit.

In such a recess 210 can, as in 2 shown after inserting the double T-beam 190 between the two tank chambers 130 . 130 ' the terminal connection section 220 be arranged, the two tank chambers 130 . 130 ' combines.

The pressure tank can be at its terminal sides 225 . 225 ' , as in 3 shown with two lids 230 . 230 ' be closed, with one of the lids 230 a valve device 240 may have over which the pressure tank 100 fueled or can be removed via the fluid from the pressure tank. For terminal stabilization can also be an annular extending in the circumferential direction reinforcement of a fiber-plastic composite at the terminal sides 225 . 225 be arranged. Through the reinforcement 250 . 250 ' can on the one hand the pressure tank 100 On the other hand, the reinforcement can also be used to fix and stabilize the lid 230 . 230 ' be used.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 60207082 T2 [0002]
• WO 2012100923 A1 [0003]
• EP 1034395 B1 [0004]

Claims (14)

Pressure tank for receiving pressurized fluids, in particular for motor vehicles, having a body which is oval-cylindrical in outer form (US Pat. 180 ) and two end-mounted lids ( 230 . 230 ' ), the body ( 180 ) one, at least two tank chambers ( 130 . 130 ' ), inner tank ( 120 ) and one the at least two tank chambers ( 130 . 130 ' ) in the circumferential direction ( 140 ) surrounding sheath ( 110 ) of a fiber-plastic composite, wherein the at least two tank chambers ( 130 . 130 ' ) longitudinal ( 150 ) are arranged substantially parallel to each other, and via a terminal connecting portion ( 220 ) are hydraulically connected to each other, and wherein between at least two tank chambers ( 130 . 130 ' ) A carrier ( 190 ) is used as a separate component, with the inside of the sheath ( 110 ), so that it has internal pressure forces acting on the sheathing ( 110 ), absorb and stabilize the oval shape. Pressure tank according to claim 1, characterized in that the at least two tank chambers ( 130 . 130 ' ) and the terminal connection section ( 220 ) are integrally connected or integrally formed. Pressure tank according to one of the preceding claims, characterized in that at least one tank chamber, preferably both tank chambers ( 130 . 130 ' ), on at least one terminal side ( 225 . 225 ' ), preferably at both end sides, are concave. Pressure tank according to one of the preceding claims, characterized in that the carrier ( 190 ) is made essentially of fiber-plastic composite. Pressure tank according to one of the preceding claims, characterized in that the carrier ( 190 ) is designed as a double-T-carrier. Pressure tank according to one of the preceding claims, characterized in that the carrier ( 190 ) a terminal recess ( 210 ), in which the terminal connection section ( 220 ) is arranged. Pressure tank according to one of the preceding claims, characterized in that the carrier ( 190 ) is concave terminal. Pressure tank according to one of the preceding claims, characterized in that at least one tank chamber ( 130 . 130 ' ) in one, on the carrier ( 190 ) adjoining area complementary to the carrier ( 190 ) is trained. Pressure tank according to one of the preceding claims, characterized in that at least one tank chamber ( 130 . 130 ' ) in at least one, not on the carrier ( 190 ) adjacent area oval-arc-shaped. Pressure tank according to one of the preceding claims, characterized in that at least one terminally arranged lid, preferably both terminally arranged lid ( 230 . 230 ' ), concave. Pressure tank according to one of the preceding claims, characterized in that at least one terminally arranged cover ( 230 . 230 ' ) a valve device ( 240 ) having. Pressure tank according to claim 11, characterized in that the valve device ( 240 ) in the region of the terminal connection section ( 220 ), wherein the valve device ( 240 ) is preferably designed such that the at least two tank chambers ( 130 . 130 ' ) by means of the valve device ( 240 ) can also be hydraulically separated from each other. Pressure tank according to one of the preceding claims, characterized in that the pressure tank ( 100 ) two terminal in the circumferential direction ( 140 ) reinforcements ( 250 . 250 ' ) comprises a fiber-plastic composite. Pressure tank according to one of the preceding claims, characterized in that at least two components selected from the following group: sheath ( 110 ), Inner tank ( 120 ), Tank chamber ( 130 . 130 ' ), Carrier ( 190 ), Reinforcement ( 250 . 250 ' ), Lid ( 230 . 230 ' ) or valve device ( 240 ) are glued or welded together.

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