CA2541427A1 - Device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure - Google Patents
Device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure Download PDFInfo
- Publication number
- CA2541427A1 CA2541427A1 CA002541427A CA2541427A CA2541427A1 CA 2541427 A1 CA2541427 A1 CA 2541427A1 CA 002541427 A CA002541427 A CA 002541427A CA 2541427 A CA2541427 A CA 2541427A CA 2541427 A1 CA2541427 A1 CA 2541427A1
- Authority
- CA
- Canada
- Prior art keywords
- profiled element
- sealing ring
- hollow profiled
- plug
- face
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000007789 sealing Methods 0.000 claims abstract description 101
- 239000012530 fluid Substances 0.000 claims abstract description 25
- 230000002093 peripheral effect Effects 0.000 claims abstract description 14
- 239000011324 bead Substances 0.000 claims description 10
- 125000006850 spacer group Chemical group 0.000 claims description 6
- 230000005923 long-lasting effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 3
- 238000003892 spreading Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- -1 for example Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 229920002635 polyurethane Polymers 0.000 description 2
- 239000004814 polyurethane Substances 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000001595 contractor effect Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000005429 filling process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
- B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
- B21D26/033—Deforming tubular bodies
- B21D26/045—Closing or sealing means
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Sealing Devices (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
- Pressure Vessels And Lids Thereof (AREA)
Abstract
The invention relates to a device for forming a peripherally closed hollow profiled element (1) by means of fluidic internal high pressure. Said device contains an axial plug (4) for sealing the hollow profiled element (1) on the end thereof, said plug comprising an axial through channel (5) supplying a pressurised fluid. The axial plug (4) comprises a sealed body having a trough-like recess (20) on the front side (19) thereof, the peripheral wall (21) of said recess being radially expandable in an elastic manner inside the hollow profiled element (1), by means of pressurised fluid, until it hits the inner wall (22) of the hollow profiled element (1) in a sealing manner. In order to obtain a long-lasting sealability of the device, the axial plug (4) comprises a head (8) formed by an annular collar (10) and a tapered extension (11) adjacent to the annular collar on the front side (7) of the head (8), and a radial annular abutment located on the body (9) of the plug and placed on the end edge (12) of the hollow profiled element (13). The sealing body embodied as a sealing ring (17) is fixed to the extension (11), and the end (28) of the annular collar (10) projects past the outer side (27) of the sealing ring (17) at at least one point in the radial direction.
Description
P03&25&/WO/1 DaimlerChrysler AG
Device for forming a peripherally closed hollow rofiled element by means of fluidic internal high pressure The invention relates to a device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure according to the preamble of patent claim 1.
A generic device is known from DE 199 05 849 C1. The device described there comprises an internal high pressure forming die, in the forming space of which a hollow profiled element can be laid, while the peripherally closed hollow profiled element is to be expanded into a final form by means of fluidic internal high pressure during the closing of the internal high pressure forming die. The device comprises, furthermore, an axial plug, by means of which the hollow profiled element is to be sealed off on the end face and which possesses an axial passage duct, via which a pressure fluid can be introduced into the hollow profiled element interior for expansion. The plug head of the axial plug, said plug head penetrating into the hollow profiled element according to figure 5 and figure 7, is designed as an elastic sealing body and consists of polyurethane. The elastic sealing body has, on its end face, a trough-like depression, of which the peripheral wall projecting into the hollow profiled element can be spread radially elastically, during the expansion process, by means of a pressure fluid, until it comes to bear sealingly against the inner wall of the hollow profiled element. If, then, an axial plug designed in this way is pushed into the hollow profiled element, the sealing body of the axial plug comes unavoidably into contact with the sharp inner edge, often having metal chips, of the hollow profiled element end, so that the sealing body is ' CA 02541427 2006-04-04 P036256/t~TO/1
Device for forming a peripherally closed hollow rofiled element by means of fluidic internal high pressure The invention relates to a device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure according to the preamble of patent claim 1.
A generic device is known from DE 199 05 849 C1. The device described there comprises an internal high pressure forming die, in the forming space of which a hollow profiled element can be laid, while the peripherally closed hollow profiled element is to be expanded into a final form by means of fluidic internal high pressure during the closing of the internal high pressure forming die. The device comprises, furthermore, an axial plug, by means of which the hollow profiled element is to be sealed off on the end face and which possesses an axial passage duct, via which a pressure fluid can be introduced into the hollow profiled element interior for expansion. The plug head of the axial plug, said plug head penetrating into the hollow profiled element according to figure 5 and figure 7, is designed as an elastic sealing body and consists of polyurethane. The elastic sealing body has, on its end face, a trough-like depression, of which the peripheral wall projecting into the hollow profiled element can be spread radially elastically, during the expansion process, by means of a pressure fluid, until it comes to bear sealingly against the inner wall of the hollow profiled element. If, then, an axial plug designed in this way is pushed into the hollow profiled element, the sealing body of the axial plug comes unavoidably into contact with the sharp inner edge, often having metal chips, of the hollow profiled element end, so that the sealing body is ' CA 02541427 2006-04-04 P036256/t~TO/1
- 2 -damaged simply even when being pushed into the hollow profiled element. Further damage to the sealing body occurs when the axial plug is drawn out after the expansion of the hollow profiled element has taken place. Admittedly, this problem is to some extent remedied; on the one hand, in that the sealing body has integrated into it beforehand a wearing strip which comes into contact essentially with the inner edge of the hollow profiled element end or, on the other hand, by the arrangement of a steel attachment which carries the sealing body, only its outside coming in contact with the inner edge of the hollow profiled element end.
However, these measures, on the one hand, are relatively complicated in terms of production and, on the other hand, do not afford sufficient sealing off of the hollow profiled element with respect to the pressure fluid flowing into the hollow profiled element for expansion. Furthermore, the wearing strip and that part of the steel attachment which comes in contact with the hollow profiled element are likewise subjected to wear, thus leading to a failure of sealability after multiple use of the axial plug.
The object on which the invention is based is to develop a generic device to the effect that its sealability is maintained permanently.
'the object is achieved, according to the invention, by means of the features of patent claim 1.
By the plug, on the one hand, and the sealing body, on the other hand, being designed according to the invention, the latter is sufficiently protected from contact with the inner edge of the hollow profiled element end by that projection of the plug head which is formed by the annular collar of the latter, when the plug head is being pushed into the hollow profiled element. In the pushed-in position of the axial plug,
However, these measures, on the one hand, are relatively complicated in terms of production and, on the other hand, do not afford sufficient sealing off of the hollow profiled element with respect to the pressure fluid flowing into the hollow profiled element for expansion. Furthermore, the wearing strip and that part of the steel attachment which comes in contact with the hollow profiled element are likewise subjected to wear, thus leading to a failure of sealability after multiple use of the axial plug.
The object on which the invention is based is to develop a generic device to the effect that its sealability is maintained permanently.
'the object is achieved, according to the invention, by means of the features of patent claim 1.
By the plug, on the one hand, and the sealing body, on the other hand, being designed according to the invention, the latter is sufficiently protected from contact with the inner edge of the hollow profiled element end by that projection of the plug head which is formed by the annular collar of the latter, when the plug head is being pushed into the hollow profiled element. In the pushed-in position of the axial plug,
- 3 -the annular collar lies with only slight play within the hollow profiled element, so that it is possible that the annular collar comes briefly into contact with the hollow profiled element end when the axial plug is pushed in. Since the annular collar does not necessarily have to implement the provisional sealability of the axial plug, but, instead, this is fulfilled by a radially projecting stop, adjoining the annular collar, of the axial plug, the wear on the annular collar which may occur due to contact with the hollow profiled element end is only marginal. Thus, in the position of use of the axial plug, the annular collar lies within the hollow profiled element, without a press fit, which is known from the prior art, being formed between said annular collar and the hollow profiled element end. By the sealing body being designed as a sealing ring, the latter can be mounted in a simple way on the plug head. Moreover, it can easily be exchanged when this is considered necessary in the case of different hollow profiled elements. It is therefore not necessary to employ a different axial plug in each case for each intended use, that is to say for different hollow profiled elements having a different diameter or cross section. The outlay in terms of apparatus for the device according to the invention is therefore simplified considerably. Owing to the protection afforded to the sealing ring by the annular collar, the sealability of the axial plug and consequently of the device is maintained permanently.
In a preferred development of the invention as claimed in claim 2, the margin of the annular collar narrows conically toward the end face of the plug head. This gives rise within the hollow profiled element, behind the sealing ring, to an annular chamber into which the pressure fluid entering the hollow profiled element via the axial passage duct of the axial plug can partially flow past the sealing ring. This gives rise to a _ g -suction action on the sealing ring, with the result that the peripheral wall of the latter is spread open more quickly.
In a particularly preferred embodiment of the invention as claimed in claim 3, the sealing ring is supported on the end face of the annular collar. As a result, the sealing ring acquires particularly reliable large-area bearing contact and is fixed on the plug head on one side in the axial direction against slipping out of place. The end face at the same time forms a stop for the sealing ring, so that the sealing ring acted upon by the flow can spread open.
In a further preferred development of the invention as claimed in claim 4, the sealing ring is supported on its depression bottom, in the direction of the end face of the plug head, by means of a positioning ring which is embedded in a groove of the extension. As a result of the arrangement of the positioning ring, the sealing ring is fixed axially with respect to the end face of the plug head.
In a further preferred development as claimed in claim 5, a spacer ring is arranged between the positioning ring and the depression bottom of the sealing ring. By virtue of the arrangement of a spacer ring, not only can the positioning ring and consequently the sealing ring be mounted more simply in its fixing, but it is then also possible, during mounting, to press the sealing ring against the annular collar via the spacer ring and, after the positioning ring has been embedded in the groove of the extension, to Leave the sealing ring in its prestressed position. What is achieved by the sealing ring being pressed against the annular collar is that the pressure fluid, which, when it flows into the hollow profiled element, flows for a short time around the sealing ring, cannot penetrate into the gap between the sealing ring and the annular collar of the plug head and consequently undermine the sealability of the sealing ring.
In a further advantageous embodiment of the invention as claimed in claim 6 an annular bead, which projects radially beyond the entire annular collar of the plug, is formed on the outside of the sealing ring. By means of the annular bead, which has a slight oversize with ZO respect to the inside diameter of the hollow profiled element, provisional sealing off is achieved even when the axial plug is being pushed into the hollow profiled element, since the annular bead can bear elastically against the inner wall of the hollow profiled element .
Although the annular bead undergoes specific wear when it penetrates into the hollow profiled element since it comes into contact with the inner edge of the hollow profiled element, the sealabilty of the sealing ring as a whole is not adversely affected, since the wear does not encroach upon the actual sealing ring. Owing to this provisional sealing off, when the pressure fluid flows into the hollow profiled element interior there is no leakage which could escape from the gap occurring during bearing contact between the stop of the plug body and the hollow profiled element.
In a further preferred embodiment of the invention, on the outside of the sealing ring has incorporated in it, near its end face facing away from the annular collar, a peripheral groove, which receives a retaining ring possessing an elasticity identical to or deviating from that of the sealing ring. The retaining ring, which may consist of a hard material, such as, for example, polytetrafluoroethylene or the like, and is so thin that it does not come into contact with the inner edge of the hollow profiled element when the plug head penetrates into the latter and therefore does not undergo any wear, has the effect that the sealing ring is best protected against being folded round and extruded into the gap occurring during bearing contact between the stop of the plug body and the end of the hollow profiled element. Within the scope of the invention, however, it is also conceivable that the retaining ring, which to some extent holds the sealing ring together when the latter is spread open, is actually configured such that it can assume the function of the abovementioned annular bead.
In a further preferred development of the invention as claimed in claim 8, a circular centering plate provided with eccentric passage bores and projecting peripherally beyond the sealing ring radially is arranged, with a central leadthrough, on the extension, so as to precede the sealing ring toward the end face of the plug head. The arrangement of the centering plate has an advantageous effect in the case of nonround tubes, in that it is introduced into the hollow profiled element virtually as a protective shield in front of the sealing ring and at the same time centers the axial plug within the nonround tube.
The sealing ring consequently cannot come into wearing contact with the hollow profiled element. The eccentric passage bores are intended to allow the introduced pressure fluid to flow onto the sealing ring, so that the latter can exercise its spreading-open movement and therefore its sealability.
The invention is explained in more detail below by means of several exemplary embodiments illustrated in the drawings in which:
fig. 1 shows a lateral longitudinal section through a detail of an axial plug of a device according to the invention, in the position of use within the hollow profiled element, fig. 2 shows a lateral longitudinal section through the axial plug from figure 1, with an annular bead formed on a sealing ring of the axial plug, fig. 3 shows a lateral longitudinal section through the axial plug from figure 1, with a retaining ring embedded on the outside on a sealing ring of the axial plug, fig. 4 shows a lateral longitudinal section through the axial plug from figure 1, with a centering plate preceding a sealing ring of the axial plug on the end face.
Figure 1 illustrates a device for forming a peripherally closed hollow profiled element 1 by means of fluidic internal high pressure, said device containing an internal high pressure forming die 2, in the forming space 3 of which the hollow profiled element 1 is laid. The device contains, furthermore, at least one axial plug 4 for sealing off the hollow profiled element 1 on the end face. The axial plug 4 possesses a centrally running axial passage duct 5 which supplies pressure fluid to the hollow profiled element 1 and which is connected at an end 6 facing away from a hollow profiled element to a fluid high pressure generation system conveying the pressure fluid and which issues on the end face 7 of its plug head 8 penetrating into the hollow profiled element 1 in the position of use. The plug head 8 capable of being pushed into the hollow profiled element 1 is rigidly connected to the remaining plug body 9 of the axial plug 4 and is formed by an annular collar 10 shaped out on the axial plug 4 and by a narrowed extension 11 adjoining said annular collar toward the end face 7 of the head 8. The extension 11 is arranged centrally and has the passage duct 5 passing through it. The axial plug 4 has, furthermore, on its plug body 9, a radially g peripheral stop which, in the position of use of the axial plug 4, bears against the closing edge 12 of the hollow profiled element end 13. The stop is formed here by the end face 14 of a sleeve 15 screwed onto the plug body 9 or fastened to the plug body 9 in another way.
For positioning the sleeve 15 during mounting on the plug body 9, the end face 14 of said sleeve butts against the rear side 16 of the annular collar 10.
The axial plug 4 carries a sealing body which is designed as a sealing ring 17 pushed or slipped onto the extension 11 of the plug head 8. In this case, the sealing ring 17 is supported on the end face 18 of the annular collar 10, said end face facing the hollow profiled element 1. The sealing ring 17, spreadable in a radially elastic manner, consists, for example, of an elastomer or polyurethane. It has, on its end face 19 facing the hollow profiled element 1, a trough-like depression 20, the peripheral wall 21 of which, by means of the inflowing pressure fluid, undergoes the spread within the hollow profiled element 1 until it comes to bear sealingly against the inner wall 22 of the hollow profiled element 1. The sealing ring 17, furthermore, is supported on its depression bottom 23, in the direction of the end face 7 of the plug head 8, by means of a positioning ring 24 which is embedded in a groove 25 of the extension 11. Moreover, a spacer ring 26 is arranged between the positioning ring 24 and the depression bottom 23 of the sealing ring 17. By support by means of the positioning ring 24 and the spacer ring 26, on the one hand, and by support on the end face 18 of the annular collar 10, the sealing ring 17 is fixed axially to the plug head 8. The outside diameter of the sealing ring 17 is selected such that it lies with some play within the hollow profiled element 1 in the position of use of the axial plug 4.
Furthermore, the outside diameters of the outside 27 of the sealing ring 17 and of the margin 28 of the annular collar 10 are coordinated with one another such that the latter projects peripherally beyond the sealing ring 17 at at least one point in the radial direction.
That is to say, on the annular collar 10, there is at least one point which is peripherally larger radially than the entire outside 27 of the sealing ring 17. The margin 28 of the annular collar 10, moreover, narrows conically toward the end face 7 of the plug head 8, thus forming, between the margin 28 of the inner wall 22 of the hollow profiled element I and the rear side 29, supported on the annular collar 10, of the sealing ring 17, a small annular chamber 30 into which a part quantity of the pressure fluid can briefly flow during filling.
If, then, the hollow profiled element 1 is filled via the passage duct 5 of the axial plug 7 with the pressure fluid conveyed by the fluid high pressure generation system, said pressure fluid flows in back stroke into the depression 20 of the sealing ring 17, with the result that, on account of the flow pressure on the peripheral wall 21 of the elastic sealing ring 17, the latter spreads open until said wall is pressed against the inner wall 22 of the hollow profiled element 1. At the same time, as already mentioned, a part quantity of pressure fluid flows past the sealing ring 17 into the chamber 30, with the result that a suction action occurs which assists the spreading of the sealing ring 17 and consequently accelerates sealing off during filling. The trough shape of the depression 20 serves in this case for a better conversion of the flow force of the inflowing pressure fluid into a radial spreading movement of the peripheral wall 21 of the sealing ring 17. If, then, the hollow profiled element 1 is formed, the pressure fluid is put under high pressure, with the result that the peripheral wall 21 of the sealing ring 17 is pressed to an extreme extent against the inner wall 22 of the hollow profiled element 1, so that a sealing off of the hollow profiled element 1 which is tight to fluid high pressure is ensured outwardly.
A variant of the invention is shown in figure 2. In this case, on the outside 27 of the sealing ring 17, an annular bead 31 is formed, which projects radially beyond the entire annular collar 10 of the plug 4 and which is located near the end face 19 of the sealing ring 17. The annular bead 31 may be injection-molded onto the sealing ring 17 at a later stage or else be shaped at the same time as the production of the latter. On account of the annular bead 31, sealing off is afforded even during the penetration of the axial plug 4 into the hollow profiled element 1 before the filling operation.
In a further variant of the invention according to f figure 3 , contrary to the variants of f figures 1 and 2 , the outside 27 of the sealing ring 17 has incorporated in it, near its end face 19 facing away from the annular collar, a peripheral groove 32 which receives a retaining ring 33 possessing a lower elasticity than the sealing ring 17. If there is an oversize of the retaining ring 33 with respect to the diameter of the inner wall 22 of the hollow profiled element 1, the retaining ring 33, preferably designed as a quad ring or O-ring, assumes the provisional sealing function at the commencement of the filling process. By virtue of its contracting action on the sealing ring 17, the retaining ring 33 gives the sealing ring 17 better protection against being folded round and extruded into the interspace between the plug head 8 and the inner wall 22 of the hollow profiled element 1.
In contrast to the preceding exemplary embodiments, in a variant of the invention according to figure 4, the extension 11 has arranged on it a centering plate 34 which peripherally projects radially beyond the sealing ring 17 and the annular collar 10. The centering plate 34 precedes the sealing ring 17 toward the end face 7 of the plug head 8 and is fastened to the extension 11 by means of a central leadthrough 35, and, for mounting, it is advantageous if, as here, the centering plate 34 can be screwed onto the extension 11. So that the introduced pressure fluid can flow onto the sealing ring 17 in spite of the preceding centering plate 34, with the result that the spreading movement can take place, eccentric passage bores 36 are formed in the circular centering plate 34.
In all the abovementioned variants, it is additionally conceivable that one or more radial ducts, which issue into the depression 20 of the sealing ring 17, branch off from the passage duct 5 of the axial plug 4 at the location of the depression 20. The peripheral wall 21 of the sealing ring 17 can thereby be acted upon, even in an early phase of the filling operation, by pressure fluid via the radial ducts as a result of a branch-off and at the same time be spread open. Very early sealing off is provided in this case.
By means of the device according to the invention, which makes it possible for the hollow profiled element 1 to be sealed off outwardly without any axial force, it is possible, as compared with seals not free of axial force, to expand hollow profiled elements 1 by means of internal high pressure and to calibrate them, without shortening the component length, since the axial force, which, when the hollow profiled element 1 is being sealed off, leads to a component-shortening thickening of the hollow profiled element end, is dispensed with. At the same time, creases are also avoided, which normally arise due to the sealing force fraction of the axial plugs in the case of seals not free of axial force. Moreover, via the sleeve 15, an axial secondary push during forming may take place at any time, as required, during the forming process.
In a preferred development of the invention as claimed in claim 2, the margin of the annular collar narrows conically toward the end face of the plug head. This gives rise within the hollow profiled element, behind the sealing ring, to an annular chamber into which the pressure fluid entering the hollow profiled element via the axial passage duct of the axial plug can partially flow past the sealing ring. This gives rise to a _ g -suction action on the sealing ring, with the result that the peripheral wall of the latter is spread open more quickly.
In a particularly preferred embodiment of the invention as claimed in claim 3, the sealing ring is supported on the end face of the annular collar. As a result, the sealing ring acquires particularly reliable large-area bearing contact and is fixed on the plug head on one side in the axial direction against slipping out of place. The end face at the same time forms a stop for the sealing ring, so that the sealing ring acted upon by the flow can spread open.
In a further preferred development of the invention as claimed in claim 4, the sealing ring is supported on its depression bottom, in the direction of the end face of the plug head, by means of a positioning ring which is embedded in a groove of the extension. As a result of the arrangement of the positioning ring, the sealing ring is fixed axially with respect to the end face of the plug head.
In a further preferred development as claimed in claim 5, a spacer ring is arranged between the positioning ring and the depression bottom of the sealing ring. By virtue of the arrangement of a spacer ring, not only can the positioning ring and consequently the sealing ring be mounted more simply in its fixing, but it is then also possible, during mounting, to press the sealing ring against the annular collar via the spacer ring and, after the positioning ring has been embedded in the groove of the extension, to Leave the sealing ring in its prestressed position. What is achieved by the sealing ring being pressed against the annular collar is that the pressure fluid, which, when it flows into the hollow profiled element, flows for a short time around the sealing ring, cannot penetrate into the gap between the sealing ring and the annular collar of the plug head and consequently undermine the sealability of the sealing ring.
In a further advantageous embodiment of the invention as claimed in claim 6 an annular bead, which projects radially beyond the entire annular collar of the plug, is formed on the outside of the sealing ring. By means of the annular bead, which has a slight oversize with ZO respect to the inside diameter of the hollow profiled element, provisional sealing off is achieved even when the axial plug is being pushed into the hollow profiled element, since the annular bead can bear elastically against the inner wall of the hollow profiled element .
Although the annular bead undergoes specific wear when it penetrates into the hollow profiled element since it comes into contact with the inner edge of the hollow profiled element, the sealabilty of the sealing ring as a whole is not adversely affected, since the wear does not encroach upon the actual sealing ring. Owing to this provisional sealing off, when the pressure fluid flows into the hollow profiled element interior there is no leakage which could escape from the gap occurring during bearing contact between the stop of the plug body and the hollow profiled element.
In a further preferred embodiment of the invention, on the outside of the sealing ring has incorporated in it, near its end face facing away from the annular collar, a peripheral groove, which receives a retaining ring possessing an elasticity identical to or deviating from that of the sealing ring. The retaining ring, which may consist of a hard material, such as, for example, polytetrafluoroethylene or the like, and is so thin that it does not come into contact with the inner edge of the hollow profiled element when the plug head penetrates into the latter and therefore does not undergo any wear, has the effect that the sealing ring is best protected against being folded round and extruded into the gap occurring during bearing contact between the stop of the plug body and the end of the hollow profiled element. Within the scope of the invention, however, it is also conceivable that the retaining ring, which to some extent holds the sealing ring together when the latter is spread open, is actually configured such that it can assume the function of the abovementioned annular bead.
In a further preferred development of the invention as claimed in claim 8, a circular centering plate provided with eccentric passage bores and projecting peripherally beyond the sealing ring radially is arranged, with a central leadthrough, on the extension, so as to precede the sealing ring toward the end face of the plug head. The arrangement of the centering plate has an advantageous effect in the case of nonround tubes, in that it is introduced into the hollow profiled element virtually as a protective shield in front of the sealing ring and at the same time centers the axial plug within the nonround tube.
The sealing ring consequently cannot come into wearing contact with the hollow profiled element. The eccentric passage bores are intended to allow the introduced pressure fluid to flow onto the sealing ring, so that the latter can exercise its spreading-open movement and therefore its sealability.
The invention is explained in more detail below by means of several exemplary embodiments illustrated in the drawings in which:
fig. 1 shows a lateral longitudinal section through a detail of an axial plug of a device according to the invention, in the position of use within the hollow profiled element, fig. 2 shows a lateral longitudinal section through the axial plug from figure 1, with an annular bead formed on a sealing ring of the axial plug, fig. 3 shows a lateral longitudinal section through the axial plug from figure 1, with a retaining ring embedded on the outside on a sealing ring of the axial plug, fig. 4 shows a lateral longitudinal section through the axial plug from figure 1, with a centering plate preceding a sealing ring of the axial plug on the end face.
Figure 1 illustrates a device for forming a peripherally closed hollow profiled element 1 by means of fluidic internal high pressure, said device containing an internal high pressure forming die 2, in the forming space 3 of which the hollow profiled element 1 is laid. The device contains, furthermore, at least one axial plug 4 for sealing off the hollow profiled element 1 on the end face. The axial plug 4 possesses a centrally running axial passage duct 5 which supplies pressure fluid to the hollow profiled element 1 and which is connected at an end 6 facing away from a hollow profiled element to a fluid high pressure generation system conveying the pressure fluid and which issues on the end face 7 of its plug head 8 penetrating into the hollow profiled element 1 in the position of use. The plug head 8 capable of being pushed into the hollow profiled element 1 is rigidly connected to the remaining plug body 9 of the axial plug 4 and is formed by an annular collar 10 shaped out on the axial plug 4 and by a narrowed extension 11 adjoining said annular collar toward the end face 7 of the head 8. The extension 11 is arranged centrally and has the passage duct 5 passing through it. The axial plug 4 has, furthermore, on its plug body 9, a radially g peripheral stop which, in the position of use of the axial plug 4, bears against the closing edge 12 of the hollow profiled element end 13. The stop is formed here by the end face 14 of a sleeve 15 screwed onto the plug body 9 or fastened to the plug body 9 in another way.
For positioning the sleeve 15 during mounting on the plug body 9, the end face 14 of said sleeve butts against the rear side 16 of the annular collar 10.
The axial plug 4 carries a sealing body which is designed as a sealing ring 17 pushed or slipped onto the extension 11 of the plug head 8. In this case, the sealing ring 17 is supported on the end face 18 of the annular collar 10, said end face facing the hollow profiled element 1. The sealing ring 17, spreadable in a radially elastic manner, consists, for example, of an elastomer or polyurethane. It has, on its end face 19 facing the hollow profiled element 1, a trough-like depression 20, the peripheral wall 21 of which, by means of the inflowing pressure fluid, undergoes the spread within the hollow profiled element 1 until it comes to bear sealingly against the inner wall 22 of the hollow profiled element 1. The sealing ring 17, furthermore, is supported on its depression bottom 23, in the direction of the end face 7 of the plug head 8, by means of a positioning ring 24 which is embedded in a groove 25 of the extension 11. Moreover, a spacer ring 26 is arranged between the positioning ring 24 and the depression bottom 23 of the sealing ring 17. By support by means of the positioning ring 24 and the spacer ring 26, on the one hand, and by support on the end face 18 of the annular collar 10, the sealing ring 17 is fixed axially to the plug head 8. The outside diameter of the sealing ring 17 is selected such that it lies with some play within the hollow profiled element 1 in the position of use of the axial plug 4.
Furthermore, the outside diameters of the outside 27 of the sealing ring 17 and of the margin 28 of the annular collar 10 are coordinated with one another such that the latter projects peripherally beyond the sealing ring 17 at at least one point in the radial direction.
That is to say, on the annular collar 10, there is at least one point which is peripherally larger radially than the entire outside 27 of the sealing ring 17. The margin 28 of the annular collar 10, moreover, narrows conically toward the end face 7 of the plug head 8, thus forming, between the margin 28 of the inner wall 22 of the hollow profiled element I and the rear side 29, supported on the annular collar 10, of the sealing ring 17, a small annular chamber 30 into which a part quantity of the pressure fluid can briefly flow during filling.
If, then, the hollow profiled element 1 is filled via the passage duct 5 of the axial plug 7 with the pressure fluid conveyed by the fluid high pressure generation system, said pressure fluid flows in back stroke into the depression 20 of the sealing ring 17, with the result that, on account of the flow pressure on the peripheral wall 21 of the elastic sealing ring 17, the latter spreads open until said wall is pressed against the inner wall 22 of the hollow profiled element 1. At the same time, as already mentioned, a part quantity of pressure fluid flows past the sealing ring 17 into the chamber 30, with the result that a suction action occurs which assists the spreading of the sealing ring 17 and consequently accelerates sealing off during filling. The trough shape of the depression 20 serves in this case for a better conversion of the flow force of the inflowing pressure fluid into a radial spreading movement of the peripheral wall 21 of the sealing ring 17. If, then, the hollow profiled element 1 is formed, the pressure fluid is put under high pressure, with the result that the peripheral wall 21 of the sealing ring 17 is pressed to an extreme extent against the inner wall 22 of the hollow profiled element 1, so that a sealing off of the hollow profiled element 1 which is tight to fluid high pressure is ensured outwardly.
A variant of the invention is shown in figure 2. In this case, on the outside 27 of the sealing ring 17, an annular bead 31 is formed, which projects radially beyond the entire annular collar 10 of the plug 4 and which is located near the end face 19 of the sealing ring 17. The annular bead 31 may be injection-molded onto the sealing ring 17 at a later stage or else be shaped at the same time as the production of the latter. On account of the annular bead 31, sealing off is afforded even during the penetration of the axial plug 4 into the hollow profiled element 1 before the filling operation.
In a further variant of the invention according to f figure 3 , contrary to the variants of f figures 1 and 2 , the outside 27 of the sealing ring 17 has incorporated in it, near its end face 19 facing away from the annular collar, a peripheral groove 32 which receives a retaining ring 33 possessing a lower elasticity than the sealing ring 17. If there is an oversize of the retaining ring 33 with respect to the diameter of the inner wall 22 of the hollow profiled element 1, the retaining ring 33, preferably designed as a quad ring or O-ring, assumes the provisional sealing function at the commencement of the filling process. By virtue of its contracting action on the sealing ring 17, the retaining ring 33 gives the sealing ring 17 better protection against being folded round and extruded into the interspace between the plug head 8 and the inner wall 22 of the hollow profiled element 1.
In contrast to the preceding exemplary embodiments, in a variant of the invention according to figure 4, the extension 11 has arranged on it a centering plate 34 which peripherally projects radially beyond the sealing ring 17 and the annular collar 10. The centering plate 34 precedes the sealing ring 17 toward the end face 7 of the plug head 8 and is fastened to the extension 11 by means of a central leadthrough 35, and, for mounting, it is advantageous if, as here, the centering plate 34 can be screwed onto the extension 11. So that the introduced pressure fluid can flow onto the sealing ring 17 in spite of the preceding centering plate 34, with the result that the spreading movement can take place, eccentric passage bores 36 are formed in the circular centering plate 34.
In all the abovementioned variants, it is additionally conceivable that one or more radial ducts, which issue into the depression 20 of the sealing ring 17, branch off from the passage duct 5 of the axial plug 4 at the location of the depression 20. The peripheral wall 21 of the sealing ring 17 can thereby be acted upon, even in an early phase of the filling operation, by pressure fluid via the radial ducts as a result of a branch-off and at the same time be spread open. Very early sealing off is provided in this case.
By means of the device according to the invention, which makes it possible for the hollow profiled element 1 to be sealed off outwardly without any axial force, it is possible, as compared with seals not free of axial force, to expand hollow profiled elements 1 by means of internal high pressure and to calibrate them, without shortening the component length, since the axial force, which, when the hollow profiled element 1 is being sealed off, leads to a component-shortening thickening of the hollow profiled element end, is dispensed with. At the same time, creases are also avoided, which normally arise due to the sealing force fraction of the axial plugs in the case of seals not free of axial force. Moreover, via the sleeve 15, an axial secondary push during forming may take place at any time, as required, during the forming process.
Claims (8)
1. A device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure, with an internal high pressure forming die, in the forming space of which the hollow profiled element can be laid, with at least one axial plug for sealing off the hollow profiled element at the end face, said axial plug possessing an axial passage duct supplying pressure fluid, the axial plug having a sealing body which possesses on its end face a trough-like depression, the peripheral wall of which can be spread open radially elastically, within the hollow profiled element, by means of pressure fluid, until said wall comes to bear sealingly against the inner wall of the hollow profiled element, characterized in that the axial plug (4) has a plug head (8) which is rigidly connected to the remaining plug body (9) and can be pushed into the hollow profiled element (1) and which is formed by an annular collar (10) and a narrowed extension (11) adjoining the latter toward the end face (7) of the head (8), in that the sealing body is a sealing ring (17) which is pushed onto the extension (11) and fixed there, the margin (28) of the annular collar (10) projecting peripherally beyond the outside (27) of the sealing ring (17) at at least one point in the radial direction, and in that the axial plug (4) has, on its plug body (9), a radial peripheral stop for bearing against the closing edge (12) of the hollow profiled element end (13).
2. The device as claimed in claim 1, characterized in that the margin (28) of the annular collar (10) narrows conically toward the end face (7) of the plug head (8).
3. The device as claimed in either one of claims 1 and 2, characterized in that the sealing ring (17) is supported on the end face (18) of the annular collar (10).
4. The device as claimed in one of claims 1 to 3, characterized in that the sealing ring (17) is supported on its depression bottom (23), in the direction of the end face (7) of the plug head (8), by means of a positioning ring (24) which is embedded in a groove (25) of the extension (11).
5. The device as claimed in claim 4, characterized in that a spacer ring (26) is arranged between the positioning ring (24) and the depression bottom (23) of the sealing ring (17).
6. The device as claimed in one of claims 1 to 5, characterized in that an annular bead (31) , which projects radially beyond the entire annular collar (10) of the plug (4), is formed on the outside (27) of the sealing ring (17).
7. The device as claimed in one of claims 1 to 5, characterized in that the outside (27) of the sealing ring (17) has incorporated in it, near its end face (19) facing away from the annular collar, a peripheral groove (32) which receives a retaining ring (33) possessing an elasticity identical to or deviating from that of the sealing ring (17).
8. The device as claimed in one of claims 1 to 7, characterized in that a circular centering plate (34) provided with eccentric passage bores (36) and projecting peripherally beyond the sealing ring (17) radially is arranged, with a central lead through (35), on the extension (11), so as to precede the sealing ring (17) toward the end face (7) of the plug head (8).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10347923A DE10347923B4 (en) | 2003-10-15 | 2003-10-15 | Device for forming a circumferentially closed hollow profile by means of fluidic internal high pressure |
| DE10347923.6 | 2003-10-15 | ||
| PCT/EP2004/010372 WO2005037456A1 (en) | 2003-10-15 | 2004-09-16 | Device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2541427A1 true CA2541427A1 (en) | 2005-04-28 |
Family
ID=34441957
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002541427A Abandoned CA2541427A1 (en) | 2003-10-15 | 2004-09-16 | Device for forming a peripherally closed hollow profiled element by means of fluidic internal high pressure |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20070107480A1 (en) |
| EP (1) | EP1673184A1 (en) |
| CA (1) | CA2541427A1 (en) |
| DE (1) | DE10347923B4 (en) |
| WO (1) | WO2005037456A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111922173A (en) * | 2020-09-29 | 2020-11-13 | 浙大宁波理工学院 | Multi-stage omega-shaped pipe fluctuation internal high-pressure forming process |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2448927B (en) * | 2007-05-04 | 2010-05-05 | Dynamic Dinosaurs Bv | Apparatus and method for expanding tubular elements |
| JP2012255478A (en) * | 2011-06-08 | 2012-12-27 | Denso Corp | Sealing system and sealing method |
| DE102013109880B4 (en) | 2012-09-10 | 2016-11-03 | National Research Council Of Canada | Low-friction end replenishment during hydroforming |
| CN109079019A (en) * | 2018-08-29 | 2018-12-25 | 河南兴迪锻压设备制造有限公司 | A kind of interior high pressure sealing push top |
| CN113967687B (en) * | 2021-11-02 | 2024-07-19 | 涿州市丰鑫管业有限公司 | Pipe expanding processing equipment |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2837810A (en) * | 1955-06-17 | 1958-06-10 | Flexonics Corp | Method of producing fittings |
| US4393674A (en) * | 1981-06-25 | 1983-07-19 | Air-Mo Hydraulics, Inc. | Hydraulic chuck device for engagement with the inside of a tube |
| DE4103082A1 (en) * | 1991-02-01 | 1992-08-27 | Eichelberg & Co Gmbh H D | METHOD FOR THE HYDROSTATIC FORMING OF HOLLOW BODIES FROM COLD FORMABLE METAL AND DEVICE FOR IMPLEMENTING THE METHOD |
| US5233854A (en) * | 1992-05-11 | 1993-08-10 | General Motors Corporation | Press apparatus for hydroforming a tube |
| US5233856A (en) * | 1992-05-29 | 1993-08-10 | General Motors Corporation | External seal unit for tube hydroforming |
| DE9320620U1 (en) * | 1993-03-25 | 1994-10-06 | Huber & Bauer GmbH, 66763 Dillingen | Device for hydroforming a tubular blank |
| DE4313312A1 (en) * | 1993-04-23 | 1994-10-27 | Nienhaus Reinhold Dipl Ing | Spreader support ring |
| US5363544A (en) * | 1993-05-20 | 1994-11-15 | Benteler Industries, Inc. | Multi-stage dual wall hydroforming |
| US5644829A (en) * | 1993-08-16 | 1997-07-08 | T I Corporate Services Limited | Method for expansion forming of tubing |
| US5445002A (en) * | 1993-08-16 | 1995-08-29 | Ti Corporate Services Limited | Fill and pressurization apparatus |
| DE19752772C2 (en) * | 1997-11-28 | 1999-09-02 | Daimler Chrysler Ag | Process for producing an air-gap-insulated exhaust pipe provided with a branch connection |
| DE19905850A1 (en) * | 1999-01-07 | 2000-07-13 | Alusuisse Lonza Services Ag | Device for reshaping a hollow profile or the like workpiece by means of hydroforming |
| DE19909927B4 (en) * | 1999-03-06 | 2005-11-24 | Audi Ag | Device for hydroforming a hollow body |
| EP1170069A1 (en) * | 2000-07-05 | 2002-01-09 | Alcan Technology & Management AG | Device for internal high pressure forming of hollow profiles |
-
2003
- 2003-10-15 DE DE10347923A patent/DE10347923B4/en not_active Expired - Fee Related
-
2004
- 2004-09-16 EP EP04765273A patent/EP1673184A1/en not_active Withdrawn
- 2004-09-16 CA CA002541427A patent/CA2541427A1/en not_active Abandoned
- 2004-09-16 WO PCT/EP2004/010372 patent/WO2005037456A1/en not_active Application Discontinuation
- 2004-09-16 US US10/576,081 patent/US20070107480A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111922173A (en) * | 2020-09-29 | 2020-11-13 | 浙大宁波理工学院 | Multi-stage omega-shaped pipe fluctuation internal high-pressure forming process |
Also Published As
| Publication number | Publication date |
|---|---|
| US20070107480A1 (en) | 2007-05-17 |
| DE10347923A1 (en) | 2005-05-19 |
| EP1673184A1 (en) | 2006-06-28 |
| WO2005037456A1 (en) | 2005-04-28 |
| DE10347923B4 (en) | 2005-07-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |