AIR BELLOWS

Description

[0001] The invention relates to an air spring bellows which is fastened at both its ends via connecting parts between a sprung and an unsprung mass, wherein the bellows has a bead-like circumferential thickening with an annular core at least at one bellows end for fastening to the respective connecting part.

[0002] Such air spring bellows are used as air suspension devices for trucks or rail vehicles, for example, between the sprung body and the unsprung chassis, or for industrial applications such as air-sprung machine mounts. The air spring bellows typically protrude more or less like a balloon between the connecting parts and can also be designed to roll along special contours or pistons provided on the connecting parts during compression.

[0003] There are different options for attaching the air spring to the connecting parts. In industrial applications, for example in machine suspension, the associated air spring bellows usually have a bead-like, circumferential thickening at their ends with an embedded core, i.e. an edge reinforced with a metal core ring. This reinforced edge is clamped to the respective connecting part, i.e. the air spring cover or the air spring rim, with another ring, namely a metal bead ring. The bead ring has a cross-section that encompasses the reinforced edge of the air spring bellows from the outside and is attached to the connecting part or cover by screws or threaded bolts / studs that are inserted through a hole in the connecting part and screwed on the outside and counter-tightened if necessary.This also clamps the edge of the air spring bellows so that an airtight connection is created between the air spring bellows and the connecting part.

[0004] Air springs for rail vehicles are also designed with a metal core at each end, i.e. at the two clamp seats, whereby the bellows must be securely fastened and sealed airtight. The fixing of one bellows end, for example in the case of a half bellows of this type, is usually also done via a separate, bolted bead ring, with which the bellows flange with integrated core is pressed positively and non-positively against a plate or surface. The correct fixing of the bellows is extremely dependent on the manufacturing tolerances and can lose its preload over time due to the settlement behavior of the elastomer. This can lead to buckling effects on the bolted upper plate and / or undefined preload of the connection. System leaks can occur, particularly in the case of large temperature fluctuations during operation.The walls of air spring bellows are typically provided with reinforcement elements, namely strength members such as cords, thread layers, or fabrics. With the conventional fixation of the bellows ends using bead rings, it is possible that the loop end—that is, the end of the cord or reinforcing fabric wrapped around the core—is insufficiently secured, creating the risk of the loop tearing. Furthermore, the bead ring represents an additional fastening element, which increases the number of parts required during assembly.

[0005] The documents US56373656A, JPS5563027A and DE202015008448U1 each disclose known air springs with respective air bellows.

[0006] The object of the invention was therefore to provide an air spring bellows whose connection to the connecting parts is as simple as possible, has the greatest possible tightness under all operating conditions, even under large temperature fluctuations, and which can be safely manufactured without separate additional components.

[0007] This problem is solved by the features of the main claim. Further advantageous embodiments are disclosed in the subclaims.

[0008] The annular core is essentially embedded in the bellows material of the air spring bellows and has devices that interact with the respective connecting part, with which the annular core together with the bellows end can be fastened to the connecting part.

[0009] This creates a secure attachment through bracing or pre-tensioning directly with the core of the bead-like, circumferential thickening at the end of the bellows using typically removable fasteners. Additional components, such as the previously common bead ring, are no longer required to connect the connecting elements to the air spring bellows.

[0010] The minimum height that an air spring can assume, depending on the deflection, the rest position, or the installation position, is no longer influenced by the screws and bead ring. The inventive connection via the core ring allows the lowest possible minimum height to be achieved. This is particularly advantageous for applications with limited installation space.

[0011] An advantageous development not according to the invention consists in that the annular core has threaded holes distributed over its circumference and arranged essentially parallel to the bellows axis, into which screws projecting through holes in the connecting parts engage. Preferably, the threaded holes are not covered by bellows material on the connection side. Threaded holes, for example, blind holes, are a very inexpensive connection that can be produced using conventional mechanical engineering fasteners, and such standardized fasteners are available in every size and strength.

[0012] The same applies to a further advantageous embodiment not according to the invention, which consists in that the annular core is distributed over its circumference and has threaded bolts arranged substantially parallel to the bellows axis and oriented in the direction of the connecting parts, projecting from the material of the bellows and extending through bores of the connecting parts.

[0013] According to the invention, the annular core has pins or bolts distributed around its circumference, arranged essentially parallel to the bellows axis and oriented in the direction of the connecting parts, protruding from the bellows material. These pins or bolts can be snapped into bores or complementary receptacles of the connecting parts. This results in a particularly quick-to-assemble connection, which, depending on the design of the complementary receptacles, can be designed either as a one-time connection or as a detachable connection.

[0014] A further advantageous design for an air spring bellows with reinforcements embedded in the bellows material is that the reinforcements are positioned in the area of ​​the bead-like, circumferential thickening, preferably wrapping around the core or ring, so that the area of ​​the holes, threaded bolts, or pins is left untouched. The reinforcements, such as the fabric layers or threads of the wound air spring bellows, are guided around the holes or threaded bolts during the manufacturing process using a suitable tool, so that the threads are not interrupted or destroyed, and the strength of the bellows wall is fully maintained.

[0015] Yet another advantageous design is that the annular core is designed as a flat disc with a flat cross-section, particularly made of metal. Metal parts can be vulcanized particularly well into the elastomeric material of the bellows wall and can be easily produced in a wide variety of shapes by rolling or other forming processes.

[0016] A further advantageous design consists in providing additional sealing elements in the area of ​​the bead-like thickening on the connection side, or in forming sealing shapes within the thickening, preferably sealing rings or sealing lips or sealing beads. Such additional sealing elements, such as O-rings, can be easily arranged in the bead area. Likewise, the thickened ends of the air spring bellows can be designed with corresponding shapes, e.g., with raised annular projections or sealing lips, which allow for additional sealing.

[0017] The invention will be explained in more detail using an exemplary embodiment. Fig. 1 shows an air spring bellows not according to the invention, Fig. 2 shows a further embodiment of an air spring bellows not according to the invention, Fig. 3 shows an air spring bellows from the prior art with a conventional connection to a connecting part.

[0018] Fig. 1 and 2 show in section and only in principle air spring bellows 1 according to the invention in a chassis of a rail vehicle, not shown in detail here, which is fastened at both its ends via connecting parts between a sprung and an unsprung mass, namely between the upper side with the body of a wagon and with its underside on the subframe of the chassis. Fig.1 and 2 show here the upper attachment to a connecting part 2 belonging to the body as an unsprung mass.

[0019] The air spring bellows or bellows 1 has a bead-like, circumferential thickening 4 with an annular core 5 at its associated bellows end 3 for attachment to the connecting part 2. The annular core 5 is essentially embedded in the bellows material and, according to the invention, has devices that interact with the connecting parts and with which the annular core, together with the bellows end, can be attached to the connecting parts.

[0020] In the Fig.1 In the embodiment shown, the annular core has threaded bores 6 distributed over its circumference and arranged substantially parallel to the bellows axis, into which screws 8 projecting through bores 7 of the connecting part 2 engage, wherein the threaded bores are not covered by bellows material on the connection side.

[0021] In the Fig.2In the embodiment shown, the annular core 9 embedded in the bead-like, circumferential thickening 4 has threaded bolts 10 distributed over its circumference, arranged essentially parallel to the bellows axis and oriented in the direction of the connecting parts, protruding from the material of the bellows, which are designed to extend through bores 11 in the connecting part 2. The threaded bolts 10 are screwed to the other side of the connecting part 2 with nuts 12.

[0022] Fig. 3For comparison, a conventional connection technique is shown, in which an air spring bellows 1 with a bead-like, circumferential thickening 4 has a simple metallic core ring 16, as is customary in the prior art. The edge of the air spring bellows thus reinforced is clamped to the connecting part 14, here the air spring cover, with a metallic bead ring 13. The bead ring 13 has a cross-sectional shape or nose 15 that surrounds the edge of the air spring bellows from the outside and is fastened to the connecting part or cover by screws 17 inserted over the outer circumference of the bead ring through the connecting part 2 engaging into corresponding threaded holes in the bead ring. List of reference symbols (part of the description)

[0023] 1Air spring bellows 2Connecting part 3Bellows end 4Thickening 5Annular core 6Threaded hole 7Hole 8Screw 9Annular core 10Threaded bolt 11Hole 12Nut 13Bead ring 14Connecting part 15Nose 16Metallic core ring 17Screw

Claims

1. Air spring bellows (1) fastened at its two ends between a sprung mass and an unsprung mass via attachment parts (2), wherein, for fastening to the attachment parts, the bellows (1) has, at least at one bellows end (3), an encircling bead-like thickened portion (4) with an annular core (5, 9), wherein the annular core (5, 9) is substantially embedded in the bellows material and has devices which interact with the respective attachment parts (2) and by way of which the annular core (5, 9), together with the bellows end, is fastenable to the attachment part (2), characterized in that that the annular core has pegs or pins arranged distributed over its circumference, arranged substantially parallel to the bellows axis, oriented in the direction of the attachment parts and protruding from the material of the bellows that are latchable into bores or complementary receptacles of the attachment parts.

2. Air spring bellows (1) according to Claim 1, having reinforcement members embedded in the bellows material, in which the reinforcement members run in the region of the encircling bead-like thickened portion, preferably the reinforcement members wrap around the core or ring, in such a way that the region of the pegs is recessed.

3. Air spring bellows (1) according to either of Claims 1 and 2, in which the annular core (5, 9) is in the form of a cross-sectionally flat disc.

4. Air spring bellows (1) according to one of Claims 1 to 3, in which the annular core (5, 9) consists of metal.

5. Air spring bellows according to one of Claims 1 to 4, in which, in the region of the bead-like thickened portion, additional sealing elements are provided at the attachment side or, in the thickened portion, there are formed forms for sealing, preferably there are arranged sealing rings or sealing lips or sealing beads.