AU2009221456A1

AU2009221456A1 - Connecting piece for a clamping connector

Info

Publication number: AU2009221456A1
Application number: AU2009221456A
Authority: AU
Inventors: Ehrenfried Bonhag; Karl-Heinz Haunstetter
Original assignee: Rehau AG and Co
Current assignee: Rehau Automotive SE and Co KG
Priority date: 2008-03-07
Filing date: 2009-03-05
Publication date: 2009-09-11
Anticipated expiration: 2029-03-05
Also published as: CN101965474A; EP2250421B1; AR070968A1; AU2009221456B2; CN101965474B; EP2250421A1; DE202008003352U1; WO2009109386A1

Description

Connecting piece for a clamping connector The invention concerns a metallic connecting piece for a clamping connector for pipes and/or hoses from a polymer material with at least two pipe/hose 5 connecting elements, wherein at least one connecting element has a plug-in area provided with peripheral ribs to push it on a pipe and/or hose end, that is joined by a flange projection. In DE 3836124 C3 a two-piece metallic clamping connector for pipes and hoses 10 from a polymer material with a connecting piece, constructed as a tubular sleeve, is described. The pipe connecting piece has a plug-in area, provided with peripheral ribs, that can be inserted into the end of the pipe. Furthermore, the plug-in area is limited in the insertion area in the axial direction by a flange projection that serves as a stop for the pipe being pushed on. 15 These metallic connecting pieces are suited to produce a liquid-tight and undetachable connection for plastic pipes and hoses, but their disadvantage is their great weight and high costs. 20 It has been demonstrated, that when using a metallic connecting piece further material savings behind the flange projection are possible. The result of this is, that when the connection is being formed, the flange projection is subjected to such a great stress that cracks may occur in this area. This may lead to leakages in the connection. 25 The invention sets as its objective to further reduce the material used for a metallic connecting piece and to prevent damaging the flange projection during the forming of the connection. At the same time the external shape of the connecting piece should only insignificantly deviate from the known metallic 30 connecting pieces. According to the invention this objective is achieved by a metallic connecting piece with the features of claim 1 and by a clamping connector with the features of claim 9.

2 The disadvantages of the state-of-the-art are eliminated by the invention by that, that on that side of the flange projection which faces the peripheral ribs at least one tooth-like protrusion is provided. 5 For the production of a clamped joint, comprising a metallic connecting piece according to the invention, a pipe/hose and a sleeve that can be slid over the plug-in area of the connecting piece and the end of the pipe/hose, a tool is used that comprises two displaceable tool jaws provided parallel with one another. In this conjunction one of the tool jaws is placed behind the flange projection of the 10 metallic connecting piece and one on the sleeve pushed onto the pipe/hose. By virtue of moving the two tool jaws towards one another the sleeve is pushed over the plug-in area of the metallic connecting piece together with the end of the pipe/hose, thus producing a liquid-tight joint. 15 By providing at least one tooth-like protrusion on that side of the flange projection which faces the peripheral ribs it is possible to produce a bearing surface for one of the tool jaws for the production of the clamped joint, while the diameter of the bearing surface corresponds to the diameter of the pipe and/or hose to be connected. A connecting piece of this kind can be easily manufactured by 20 machining, like turning, and by deformation process, like extrusion. It has been demonstrated that this matching of the diameters will assure that basically only an axial displacement of the sleeve takes place and the flange projection is very evenly stressed. 25 It is a further advantage when a free space is provided between the flange projection and the at least one tooth-like protrusion. This will achieve that the flange projection can be resiliently deformed by force during the production of the clamped joint and no cracks will form in the transition region of the tooth-like 30 protrusion and the flange projection. A simple and cost-effective possibility of reducing the material usage is that a plurality of tooth-like protrusions are provided distributed over the circumference and that between the individual tooth-like protrusions gaps are provided.

3 Consequently a continuous construction of the protrusion is not necessary. In this conjunction it has been demonstrated that it is particularly advantageous to distribute 4 to 16, in particular 8, tooth-like protrusions over the circumference. 5 A uniform distribution of the tooth-like protrusions over the circumference has also been proven advantageous. This arrangement ensures a secure support and positioning of the tool jaws whatever the accessibility of the connecting position is and consequently of the metallic connecting piece during the production of the clamped joint. 10 In a further advantageous development the tooth-like protrusions have additional functions. It has been demonstrated, that especially in the case of pipes/hoses with small dimensions there is no room on the circumference between the tooth like protrusions to affix the date codes, required by standards, to indicate the date 15 of manufacture of the connecting piece. However, to enable their placement according to the standards, it has been recognised that they too can be constructed as tooth-like protrusions. Furthermore, other information can be integrated on the tooth-like protrusions. 20 It may be an advantage that the contour of the tooth-like protrusions on that side which is averted from the flange projection is bevelled towards the axis of the plug-in area up to a diameter of the size of the plug-in area. By virtue of this bevelled construction, especially in the case of the connecting pieces, the connecting elements of which do not have a common axis, the tool jaws can be 25 securely positioned, since the bevel provides a type of guiding that lets the tool jaws slide on the protrusions. According to a preferred embodiment of the invention at least two connecting elements are provided at an angle of less than 1800. This will result in connecting 30 pieces that correspond to bends, in particular right-angle deflections, or branching offs, in particular T-pieces. In this conjunction it may be an advantage that in the case of connecting pieces of this type at least one of the several tooth-like protrusions has a smaller area than the other. This reduced tooth-like protrusion is preferably provided in the area between two connecting elements. By virtue of 4 this it is possible to move the flange projections closer to one another and thus reduce the overall space required. Because the tooth-like protrusion in the area between two connecting elements would reach the area of curvature of the connecting piece, it has been recognised that a reduction of the tooth-like 5 protrusion provided there is of advantage. Consequently there will be no peak stress in this area and at the same time the tool jaws can be securely positioned. The reduction of the tooth-like protrusion in this area between the connecting elements can be achieved in particular by a steeply sloping contour on the side that is averted from the flange projection. 10 The invention further concerns a clamping connector for pipes/hoses from a polymer material with a metallic connecting piece according to the invention and a sliding sleeve that is axially displaceable along the axis of the pipe/hose. 15 The clamping connector is characterised in that the outside diameter of the pipe/hose without the inserted plug-in area is almost exactly the same size as the outside diameter of the at least one tooth-like protrusion. By virtue of this geometric design it is possible that the tool jaws, used for the production of the clamped joint, would be aligned parallel with the flange projection and thus the 20 force is evenly introduced. Thus advantageously a liquid-tight clamped joint can be produced, without causing the formation of cracks in the region of the flange projection. The invention is now described in detail on embodiments that are of non-limiting 25 nature. They show in: Fig.1 - a metallic connecting piece according to the invention with a tooth-like protrusion 30 Fig.2a - a view of a metallic connecting piece according to the invention with a plurality of tooth-like protrusions, Fig.2b - a section through the metallic connecting piece according to the invention of Fig.2a along line A-A, 5 Fig.2c - a perspective view of the metallic connecting piece of Fig.2a, Fig.3a - a metallic connecting piece according to the invention with a tooth-like protrusion, with an additional function, 5 Fig.3b - a section through the metallic connecting piece according to the invention of Fig.3a along line B-B, Fig.4 - a schematic view of the production of a clamping connector according to 10 the invention, with a tool. In Fig.1 a metallic connecting piece (1) according to the invention is illustrated. This connecting piece (1) is constructed as a T-piece and has three connecting elements (3), while all three connecting elements (3) are constructed as plug-in 15 areas (5). In this embodiment each plug-in area (5) has four peripheral ribs (4, 4a), which are not uniformly distributed over the length of the plug-in area (5). It is, however, also feasible to provide a different number and a different distribution of the peripheral ribs (4, 4a). 20 A flange projection (6) is joined to the plug-in areas (5). The diameter of the flange projection is greater than that of the plug-in area (5) and of the peripheral ribs (4, 4a), so that a pipe or a hose (2) can be pushed onto the plug-in area (5) with its end up to the flange projection (6). Thus it is simple to check whether the plug-in area (5) has been correctly inserted into the pipe/hose (2). 25 On that side of the flange projection (6) which is averted from the plug-in areas (5) a tooth-like protrusion (7) is provided that extends over the entire periphery. Between the flange projections (6) and the tooth-like protrusion (7) a free space (8) is illustrated, that separates the tooth-like protrusions (7) from the flange 30 projections (6). By virtue of this design the flange projection (6) can be resiliently deformed by a tool (13) during the production of the clamped joint and no stress crack will occur at the connection position between the flange projection (6) and the tooth-like protrusion (7).

6 In this embodiment the tooth-like protrusions (7) are bevelled on that side which is averted from the associated flange projection (6). By this it will be achieved that during the production of the clamped joint the jaw (14) of the tool, that is placed behind the flange projection (6), due to the bevelled construction slides onto the 5 tooth-like protrusion (7) and thus the jaw (14) of the tool will assume an optimal position. In Figs.2a, 2b and 2c a further embodiment of a connecting piece (1) according to the invention is illustrated. This straight metallic connecting piece (1) has two 10 connecting elements (3). Both connecting elements (3) are constructed as plug-in areas (5) also in this embodiment. However, it is within the scope of the invention to construct a connecting element as a threaded connection, so that on this side it could be screwed together with a further component. 15 Both plug-in areas (5) have five peripheral ribs (4, 4a, 4b), while the peripheral rib (4a), furthest from the flange projection (6), has a wider construction than all the other peripheral ribs (4, 4b). In this embodiment all peripheral ribs (4, 4a), with the exception of the peripheral rib (4b) that is furthest from the flange projection (6), are constructed as rings. On that side which faces the flange projection (6) the 20 peripheral rib (4b) has a greater diameter than on the other side, so that a sort of saw-tooth will result. By virtue of this design a good anchoring of the pipe/hose (2) is possible after being pushed on and with the sliding sleeve (10) attached. Since both connecting elements (3) are constructed as plug-in areas (5), two 25 flange projections (6) are also required to provide one tool jaw (14, 14a) as a countersupport. To shorten the overall length, between the two flange projections (6) only one tooth-like protrusion (7) is required, as in the process of producing the two clamped joints this can serve as support for a tool jaw (14a). 30 Between the flange projections (6) and the tooth-like protrusions (7) a free space (8) is provided also in this example. The tooth-like protrusion (7) itself is so constructed that it comprises a plurality of individual tooth-like protrusions (7) provided on the circumference of the 7 connecting piece (1). As it can be seen from Fig.2b, the tooth-like protrusions (7) are uniformly distributed over the circumference. Between the individual tooth-like protrusions (7) a gap (9) is provided, that serves the purpose of separation of the individual tooth-like protrusions (7). 5 In the existing gaps (9) identifications regarding the material from which the connecting piece (1) is manufactured, data regarding the date of manufacture by providing so called date code or the like, can be provided. 10 Since this metallic connecting piece (1) is produced in most cases by casting, a joint face (12) is required, enabling the removal of the connecting piece (1) from the mould. To ensure that the design of the geometry of the casting mould is without unnecessary complications, no undercuts, originating from the joint face (12), must be present. This may occur especially at the individual tooth-like 15 protrusions (7). A possible solution may be the provision of bevels (11) for the removal. By arranging eight tooth-like protrusion (7) over the circumference of the connecting piece (1), it is assured that the tool jaw (14, 14a) securely supported 20 in any mounting position and at the same time the material otherwise required between the flange projections (6) can be reduced. By virtue of this reduction of the material it is also possible to retain approximately uniform wall thicknesses over the connecting piece (1), what will have a positive effect on the stress distribution after the casting. 25 In Figs.3a and 3b a further metallic connecting piece (1) is illustrated. To avoid repetitions, only the differences of the second embodiment are described. In the case of this connecting piece (1) the diameter of the connecting piece (1) is smaller than in Figs.2a, 2b, 2c, so that the length of the circumference is not 30 sufficient to accommodate all identifications, in particular the date code, in the gaps (9) between the tooth-like protrusions (7). For this reason the invention recognises that the tooth-like protrusions (7) can have additional functions. In the embodiment of Figs.3a and 3b two tooth-like 8 protrusions (7b) have additional functions. These are constructed as date codes, so that the identification of the manufacturing date of the connecting piece (1) can be shown. The diameter, up to which the date code protrudes, corresponds to that of the other tooth-like protrusions (7), so that the tool jaw (14) can be safely 5 positioned also on the date code. Fig.4 schematically illustrates the production of a clamped joint with a metallic connecting piece (1) according to the invention, of a pipe/hose (2), of a sliding sleeve (10) by means of a tool (13). To avoid repetitions, only the differences with 10 the above mentioned embodiments are described. The tool (13), illustrated in this Fig.4, is shown only as a detail of the two tool jaws (14, 14a), which are parallel with one another. During the production of the clamped joint one tool jaw (14) is firmly attached and the other tool jaw (14a) is 15 displaceable on the tool (13) along an axis (X). The tool jaws (14, 14a) have a fork-shaped design, so that it is possible to slip them on the pipe/hose (2) and the connecting piece (1). To produce the clamped joint, first the sliding sleeve (10) is placed onto the end 20 of the pipe/hose. Afterwards the end (2a) of the pipe/hose is so expanded that the inside diameter of the end (2a) of the pipe/hose will be greater than the outside diameter of the plug-in area (5) of the connecting piece (1). Only thus can the end (2a) of the pipe/hose be guided over the plug-in area (5). To enable the production of a reliable joint, the end (2a) of the pipe/hose is pushed to the flange 25 projection (6) as far as possible. Subsequently the tool jaws (14, 14a) are positioned and by reducing the distance between the tool jaws (14, 14a) the sliding sleeve (10) is pushed over the end (2a) of the pipe/hose and pushed, together with the plug-in area (5) provided 30 inside, up to the flange projection (6). This concludes the production of the clamped joint. For the reduction of the distance between the two tool jaws (14, 14a) a great force is required. This causes the movement of the sliding sleeve (10) on the one 9 hand and results in a force equalisation via the flange projections (6) on the other. To avoid damaging, in particular at the transition of the flange projection (6) to the basic body of the connecting piece (1), an as even as possible introduction of the force is necessary. This can be achieved only by an almost parallel resting of the 5 tool jaws (14, 14a) on the flange projection (6). Because both tool jaws (14, 14a) are provided parallel to one another, it has been recognised that the outside diameter of the non-expanded pipe/hose (2) and the diameter of the bearing surface of the tool (13) on the connecting piece (1) should be almost identical. This, however, results in a greater wall thickness between the two flange 10 projections (6), that has a negative affect on the stress situation during casting and means an unnecessary use of material. To solve this problem tooth-like protrusions (7), separated from the flange projection (6) by a free space (8), are provided behind the flange projection (6). In 15 the case of this connecting piece (1), illustrated in Fig.4, the distance of the opposite situated connecting elements (3) can be shortened by that in that area between the opposite situated connecting elements (3), in which the third connecting element (3) is provided, preferably on both sides an area-wise smaller tooth-like protrusion (7a) is provided. It has been recognised, that in this area the 20 tooth-like protrusion (7a) has to be constructed smaller, so that no stress peak would occur in the region of the transition and thus a reliable function can be assured.

Claims

1. A metallic connecting piece (1) for a clamping connector for pipes and/or hoses (2) from a polymer material with at least two pipe/hose connecting elements 5 (3), wherein at least one connecting element (3) has a plug-in area (5) provided with peripheral ribs (4, 4a, 4b) to push it on one end (2a) of the pipe and/or hose, that is joined by a flange projection (6), characterised in that on that side of the flange projection (6) which faces the peripheral ribs (4, 4a, 4b) at least one tooth-like protrusion (7) is provided. 10

2. A metallic connecting piece (1) according to claim 1, characterised in that a free space (8) is provided between the flange projection (6) and the at least one tooth-like protrusion (7). 15

3. A metallic connecting piece (1) according to at least one of the preceding claims, characterised in that several, in particular 8, tooth-like protrusions (7) are provided distributed over the circumference and that between the individual tooth-like protrusions (7) gaps (9) are provided. 20

4. A metallic connecting piece (1) according to claim 3, characterised in that the tooth-like protrusions (7) are equidistanced distributed over the circumference.

5. A metallic connecting piece (1) according to at least one of the preceding claims, characterised in that the tooth-like protrusion (7) is constructed with 25 additional functions, in particular as date code.

6. A metallic connecting piece (1) according to at least one of the preceding claims, characterised in that the contour of the tooth-like protrusions (7) on that side which is averted from the flange projection (6) is bevelled towards the axis 30 (X) of the plug-in area up to a diameter of the size of the plug-in area (5).

7. A metallic connecting piece (1) according to at least one of the preceding claims, characterised in that at least two connecting elements (3) are provided relative one another at an angle of less than 1800. 11

8. A metallic connecting piece (1) according to claim 7, characterised in that several tooth-like protrusions (7) are provided and at least one has a smaller area than at least one other tooth-like protrusion (7). 5

9. A clamping connector for pipes and/or hoses from a polymer material with a metallic connecting piece (1) according to one of the preceding claims with a sliding sleeve (10) that for the production of a clamped joint can be slid over the end (2a) of the pipe/hose with the plug-in area (3) of the connecting piece (1) inserted into the end (2a) of the pipe/hose, characterised in that the outside 10 diameter of the pipe/hose (2) without the inserted plug-in area (3) is almost exactly the same size as the outside diameter of the at least one tooth-like protrusion (7). 15