DE3202429A1 - Screw connection for pipe fittings and a method for their production - Google Patents

Abstract

In a screw connection for pipe fittings, in which a pipe piece is provided at its end on the connection side with a sealing surface and with a retaining collar for a cap nut, and the end of the pipe to be connected thereto is provided with an external thread, rapid fitment and security of the cap nut are achieved in that the other end of the pipe piece likewise has a retaining collar for the cap nut, the pipe piece is surrounded at at least one of its ends by a tubular shim which in each case forms one of the retaining collars, and the radial (surrounding) contact surfaces are fixed with respect to one another. The fixing preferably takes place by copper hard-soldering of the individual parts which are produced as simple rotating parts from automatic steel. Versatile application capabilities, primarily in the field of high-pressure hydraulics, result from the use of pipe curves, pivoting screwed unions and/or hose nipples.

Description

The invention relates to a screw connection for pipe arma-

doors, in which a pipe section at its connection-side end with a sealing surface and a retaining collar for a union nut and the end of the so that the pipe to be connected is provided with an external thread; Furthermore The invention relates to a method for producing such a screw connection.

Screw connections for pipe fittings can be found in hydraulic and pneumatic systems Application and must be tight against the respective fluid even at high pressure. For this purpose, the pipe end carrying the union nut can be flared, with flanged angles of 370 predominantly in Anglo-Saxon countries and those of 240, for example according to DIN 38 61, apply. With larger wall thicknesses, the flanging is very problematic. Therefore, cone or

funnel-shaped end pieces for pipes to be connected to one another, for example made by turning; these end pieces can also have grooves with 0-rings, However, their production is difficult, at least with the aforementioned 37 0 screw connections is. In addition, the contact surface should not be too severely interrupted by the O-ring groove in order not to let the surface pressure become too great.

Such, mostly prefabricated, pipe end pieces are to be connected with the Welded pipe ends. This is very time-consuming because after sliding the Union nut and production of a welding bevel - usually by hand - the connection must be tacked, dismantled and welded through. Especially with small dimensions the weld metal also reaches the inside of the pipe, so the pipe must finally be removed from be drilled out and ground on the inside.

These are very time-consuming operations, especially on construction sites. In the end the O-ring is pulled on and the whole pipe is reassembled after rinsing. Such connections meet the requirements placed on them in terms of tightness and lifespan usually good.

The screw connections in question are also used for connecting a pipe end with a hose nipple, for example in connection with a Swivel screw connection and the like.

The items of such a screw connection, for example the Retaining collar with the sealing surfaces for the union nut, the external thread and the Hose nipples must be machined in a time-consuming and material-consuming manner with considerable material losses.

The invention is therefore based on the object of providing screw connections Manufacture of the type mentioned from simple parts and quickly, safely and to be able to fit together tightly, after the preassembly the union nut and similar parts are secured against loss; such pre-assembled screw connections should be fixed to the pipe ends to be connected without major preparatory or reworking work permit.

The solution to this problem is that with a screw connection of the type mentioned above, according to the invention, the other end of the pipe section as well has a retaining collar for the union nut, the pipe section on at least one the ends of a tubular fitting piece that forms one of the retaining collars is encompassed and fixed the radial (comprehensive) contact surfaces against each other are.

Such screw connections are suitable, for example, as screw connections for mating connection, bore form W (240) according to DIN 3861, in which the sealing cone consists of a rotating part with a retaining collar for the union nut and one attached to it adjoining piece of pipe consists, the latter being a tubular at its other end Has fitting, which preferably protrudes beyond the pipe section in the axial direction.

For pre-assembly, the union nut is initially used from the free end pushed over the pipe section. Then the tubular fitting piece is over the free end of the pipe piece pushed or pressed as well as on the pipe piece through Welding, gluing or soldering fixed; likewise with the pre-assembled part at Connect with the pipe end to be screwed. The first free end of the pipe section offers a simple, safe possibility of the pipe end to be screwed with the pre-assembled screw connection part by sliding it on or off and then fixing it - quickly and accurately connect and make the union nut captive. - The same applies to a fitting at the other end of the pipe. It goes without saying that the assembly the individual parts can also be done directly on the construction site.

In the screw connection according to the invention, up to 70% of the Previous working time saved as there is no need to bevel or tack the weld seam is not required because of the forced guidance through the adapter. Also can Weld metal can no longer get into the inside of the pipe, so that time-consuming rework not applicable; the area of the sealing surface can also be produced more cost-effectively.

The pipe to be connected can have a fitting that is attached to her one end the male thread and at its other end a cylindrical Has inner surface for fixing with the outer surface of a pipe end. Accordingly a pipe end can be pushed into the cylindrical inner surface of the valve and fix in a similarly simple manner as mentioned.

The external thread and / or the cylindrical inner surface of the valve can according to the invention as a tubular fitting pieces encompassing the valve at its ends be designed with radial contact surfaces fixed against the fitting.

In this way, the fitting can be made from relatively simple turned parts exist that pushed or pressed onto the ends of the valve and with it, like described, firmly and tightly connected.

Fittings designed as swivel screw connections are particularly advantageous, because they represent a relatively small, swiveling pipe connection, which easy to manufacture and can be quickly and safely pre-assembled and fully assembled.

The sealing end of the screw connection with the union nut can also as a fitting piece comprising the end of the pipe section with a conical Sealing surface be formed, which at the same time the retaining collar for the union nut forms. In this way, the pipe section no longer needs to be shared with the retaining collar for the union nut and the sealing surface made as a single rotating part to become, instead a simple tube is sufficient, which is only used as a turned part trained fitting piece is connected in the manner described. The pre-assembly takes place here when the other retaining collar for the union nut is already in place is, by sliding the union nut from the sealing side over the pipe end; then the union nut is opened by pushing or pressing the fitting piece and its fixation secured.

The fitting piece can be designed in a particularly simple manner if it is in accordance with the invention forms the conical sealing surface together with the end of the pipe section. These Sealing surface can according to the invention in the contact area of the pipe section end and the Fitting piece have a groove for a sealing ring. Such a groove can be particularly easy to manufacture, as two surfaces of their mostly U-shaped cross-section of the Fitting piece or the pipe end are formed and the third surface (leg) of the other workpiece. The space for the deformation of the sealing ring can are then very advantageously located in an enlarged corner area of the groove without that this makes the manufacture of the groove more difficult; this results in an optimal Utilization of the sealing surfaces next to the groove, in which an O-ring is preferably inserted will.

The aforementioned screw connections with two-part sealing surfaces are particularly suitable for taper screw connections with an angle of about 370 between the pipe axis and the sealing surface. Only then is the use of Sealing rings practicable because d3 production of the ring grooves in the previous 37 ° connections is difficult for series production; 0 those produced in this way are particularly suitable where the previous gene for pipes with large wall thicknesses where the previous The usual flanging is very problematic, but is now omitted.

The connection between the pipe section of the screw connection with a Pipe end is very simplified if according to the invention a fitting piece the end of the Pipe section protrudes and a cylindrical inner surface to encompass the outer surface of the pipe end to be connected. This is especially true for larger dimensions consider expanding the pipe section at the relevant end.

The fitting piece for the connection with a pipe end, but also that The pipe section of the screw connection itself can, according to the invention, also be used as a pipe bend be designed, which saves bending on the construction site; leave that way particularly tight bending radii can be realized.

The fitting piece for the connection with a pipe end, the pipe piece the screw connection (screwing part) itself, but also the valve according to the invention, instead of a hose nipple at their respective free end one end of the pipe. This results in a screw connection between one Pipe and a hose, but also between hoses. That is, hoses are also to be understood as pipes in the broadest sense. The inserted hose nipple have the advantage over the hitherto customary overlaid that the differences in diameter arn hose nipples are lower and the machining work when turning and the Reduce material consumption.

According to the invention, one that encompasses the hose nipple and is fixed to it Retaining collar serves as a stop for the hose end pushed over; he lets himself either by turning it or something like a modified washer Slide it over the hose nipple and then through one of the methods described above fix; this reduces the machining work and the cost of materials another one. In addition, a production of the grooves of the Hose nipples by cold forming, for example cold rolling, possible.

A press fitting for the hose end can be between the retaining collar of the hose nipple and the screw connection into which it is inserted, cannot be lost be secured. An inventive support ring at the hose nipple end de s of the screw connection into which the hose nipple is inserted, limited the stretching path of the hose. The support ring can be placed separately over the hose nipple be pushed. Or it can be the end of the workpiece mentioned on the hose nipple side be expanded in a funnel shape.

In that the contact surfaces of the individual parts to be connected the screw connection are fixed with a precise fit and are therefore hard-soldered with copper leave, the individual parts to be connected can largely be made of inexpensive free-cutting steel be made. In particular, these can be simple turned parts.

High strength between the individual parts of the screw connection and great tightness even at high fluid pressures can thereby be achieved according to the invention achieve that in each case the entire contact surface area tight is fixed, in particular by soldering ,, brazing and gluing, for example by Copper brazing under protective gas.

In the method according to the invention for producing the screw connections the individual parts are put together precisely and soldered together with a copper hatch subject.

Both a press fit and a sliding fit are possible. That Joint copper soldering of all connection points shortens the assembly time considerably. Depending on the soldering temperature, any sealing rings may already be pushed on. Particularly It is advantageous to apply a copper soldering paste, especially on both contact surfaces, before joining.

An existing press socket is simultaneously soft-annealed in the soldering furnace.

The fitting or pipe pieces can be made to any desired radii and angles - preferably before joining - bend.

At the same time or separately therefrom, at least one of the ends can also be used these workpieces are widened before or partially joined together, namely in a cylindrical shape for the inclusion of pipe ends and / or funnel-shaped as a support ring or to support the To facilitate insertion of the pipe end.

The inventive welding of at least part of the Individual parts by means of an outer fillet weld are joined together and tightly fixed the individual parts, greatly simplified; Such welding is recommended especially for connecting the free pipe ends and the pre-assembled screw connection.

The assembly of passports on the conical sealing surfaces that are partly on the fitting and partly at the end of the pipe section is particularly advantageous when a mounting piece with a uniform but opposite Cone shape and a uniform threaded counterpart with the fitting piece and the union nut joined together and the pipe section is pressed in. With such a mounting device, but also due to the interference fit between the pipe section and the fitting piece is a Alignment of the angles (sealing surface) guaranteed; during the pressing-in, preferably at the same time, the other end of the pipe section for receiving the to be connected Pipe ends are widened.

The invention is illustrated below with reference to in the drawing Embodiments of the explained in more detail.

The drawing shows: FIG. 1 a screw connection for pipe fittings in perspective partial section, Fig. 2a a modified embodiment of the screw connection according to FIG. 1, FIG. 2b shows an enlarged section of the sealing surface according to FIG. 2a, Fig. 3 shows a modified screw connection similar to Fig. 1 with mounting piece Fig. 4 shows a screw connection with hose nipple in a perspective partial section, FIG. 5a shows a modified screw connection according to FIG. 4, FIG. 5b shows a partial view of a modified design of the support ring according to FIG. 5a and FIG. 6 a swivel screw connection with hose nipple in perspective partial section.

The screw connection shown in FIG. 1 has a pipe section 1 with a sealing surface 2 at its connection-side end 3. The back part the sealing surface forms a retaining collar 4 for a union nut 5. That means To be connected pipe 6 has at its end 7 an external thread 8 for screwing with the union nut. The external thread 8 is located at the end 13 of a fitting 14, which at its other end 15 has a cylindrical inner surface 16 for fixing with the outer surface 17 of the end 7 on the pipe 6 to be connected. The other The end 9 of the pipe section 1 has a further retaining collar for the union nut 5 10, which consists of a tubular fitting 11, which the pipe section 1 at his Includes end 9 and is fixed relative to this on the radial contact surface 12.

A groove 18 with an O-shaped sealing ring 19 is located in the area the sealing surface 2, which is opposite at an angle of, for example, 240 according to DIN 3861 the pipe axis 20 of the pipe section 1 is inclined conically.

The fitting 11 is designed as a pipe bend and protrudes beyond the end 9 of the pipe section 1; it has a cylindrical inner surface 21 and comprises the Outer surface 22 of a pipe end 23.

The pipe section 1 can be a simple turned part made of free-cutting steel. For pre-assembly, the union nut 5 is pushed over the pipe section 1, if necessary the Open the O-ring 19 and then slide the fitting 11 over the end 9 or pressed after previously a Kupferhatlötpaste on the contact surface 12 and possibly.

has been applied to the opposite surface. Because the fitting is the end 9 encompasses form-fitting, is unnecessary, especially with a press fit, stapling, so that the joined parts are subjected to copper brazing in a protective gas furnace can.

The pipe end 23 is after insertion into the fitting by a outer fillet weld fixed.

In Fig. 2a, the widened end 9 of the pipe section 1 acts as a Retaining collar 10 for the union nut 5. A tubular, the end 3 of the pipe section 1 comprehensive, fitting piece 24 forms the retaining collar 4 on the one hand and a part 2 ' the conical sealing surface 2 on the other hand; the other part of the sealing surface 2 forms the end 3 of the pipe section 1 with its surface 2 ". The sealing surface 2 ', 2" has in the contact area of the end 3 and the fitting piece 24 a groove 18 for a O-ring 19 on. The groove ie or the alternative groove 18 'shown in dashed lines, can each behind the sealing ring 19 enlarged corner areas 26 and 26 'for the Have deformation of the sealing ring. The groove-side edges of the sealing surfaces 2 ' and / or 2 "can be broken. The hollow cone-shaped shown in Fig. 2a / b Sealing surfaces are particularly suitable for the aforementioned 370 - # el seals. Of the sealing surface 2 and the pipe axis 20).

According to FIG. 3, both ends of the pipe section 1 can be provided with fittings be; in particular, two-part sealing surfaces 2 ', 2 "for outer cones are also included 240 inclination possible.

In Fig. 3, the pipe end 23 shown in dashed lines is by means of a fillet weld 27 is welded to the fitting piece 11, while the contact surfaces 12 and 25 are preferred are fixed tightly by gluing or soldering.

Instead of the second part of the pipe union, on the left in Fig.

3 shows a mounting piece 28, one with the sealing surface 2 uniform, but opposite, conical surface 29 and a uniform threaded counterpart 30 for the union nut 5 and can be clamped at its head 31. That Fitting piece 24 is between the mounting piece 28 and the union nut 5 clamped, and the pipe section 1 pressed in until it is on the conical surface 29 of the Assembly piece 28 comes to the plant; this means that the sealing surfaces 2 'are aligned, 2 "guaranteed. Such mounting pieces can also be used with an inverted cone for hollow cone-shaped, two-part sealing surfaces 2 are used and in particular also those with the screw connection be the fitting to be screwed.

According to FIG. 4, the pipe section 1 can also be bent and at his The widened end 9 forms the retaining collar 10 and the end 32 of a hose nipple 33 record. Because of the bend, it is advisable to use the retaining collar 4 as a paragraph to be formed on the fitting piece 24 in order to facilitate the slipping on of the union nut 5.

Except for its grooves 34, the hose nipple 33 is uniform Diameter on; it is with a retaining collar that encompasses it and is fixed to it 35 provided. As a result, a press fitting 36 for the not shown in the drawing Hose end secured between the retaining collar 35 and the fitting or the pipe section. The contact surface 37 between the retaining collar 35 and the hose nipple 33 can glued or soldered in the same operation as the other contact surfaces. It is understood that the fitting pieces 11 and 24 generally also in the manner of the retaining collar 35 can be executed.

Fig. 5a shows a modified, straight design with a hose nipple with the peculiarity that here on the hose nipple 33 a retaining collar 38 by turning was produced. In addition, there is the front side at the end 9 of the pipe section 1 a support ring 29 for the hose to be pushed on. In Fig. 5b is the same Area shown, but here is the frontal area of the hose nipple-side end of the pipe section 1 funnel-shaped widened to support the To enable sliding hose.

In Fig. 6, only the fitting 14 is shown for the sake of clarity. This is a swivel fitting for connecting a pipe and a hose; it consists of a pipe section 40 and a sealed around it rotatable rotating piece 41. The pipe section 40 carries the external thread 8 for not Union nut 5 shown and the sealing surface 42 for contact with the sealing surface 2 at one end and has radial openings 43 to an outer annular channel 44, which is in flow connection with the hose nipple 33. Ring seals 45 and 45 'allow a sealed, but relatively free, rotation of the rotating piece 41 together with the angled hose nipple 33 around the pipe section 40 in all directions transverse to the pipe section axis 46. A head part 47 forms an upper one Stop for the rotating piece 41; provided that the hose nipple 33 is a is to assume a certain direction, the rotating piece 41 can be fixed in this direction will. For example, by a lock nut, not shown, on the rotating piece side End of the external thread 8 or suitable spacer rings between the union nut and the turning piece. This can also be done against the spacer ring or the lock nut another sealing ring 45 "can be arranged at the front end of the rotating piece.

Corresponding to the fitting 14 in FIG. 1, the swivel screw connection also has 6 at its end 15 has a cylindrical inner surface 16 for fixing to the Outer surface 17 of the hose nipple end. It goes without saying that here too External thread 8 and / or the cylindrical inner surface 16 components of special May be passports.

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Claims (24)

"Screw connections for pipe fittings and processes for their manufacture Claims: Screw connection for pipe fittings in which a pipe section (1) at its connection-side end (3) with a Diohtfläche (2) and a retaining collar (4) for a union nut (5) and the end (7) of the pipe to be connected (6) is provided with an external thread (8), d u r c h g e k e n n n -z e i c h n e t that the other end (9) of the pipe section (1) also has a retaining collar (io) for the union nut (5) has the pipe section (1) on at least one of the Ends (3) or (9) of a respective one of the retaining collars (4) or (10) forming, tubular fitting piece (24, ii) is included and the radial (comprehensive) contact surfaces (25, 12) are fixed against each other. 2. Screw connection according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the pipe (6) to be connected has a fitting (14) which at one end (13) there is an external thread (8) and at its other end (15) a cylindrical inner surface (16) for fixing to the outer surface (17) of the pipe end (7). 3. Screw connection according to claim 2, d a d u r c h g e -k e n n z e i c h n e t that the external thread (8) and / or the cylindrical inner surface (16) as a tubular fitting that encompasses the valve (at its end (13) or (15)) is designed with radial contact surfaces fixed against the valve (14), 4. Screw connection according to claim 2 or 3, d a d u r c h g e -k e n n z e i c h n e t that the valve (14) consists of a swivel screw connection. 5. Screw connection according to claims 1 to 4, d a d u r c h it is noted that the end (3) comprehensive fitting piece (24) is a conical Has sealing surface (2) and forms a retaining collar (4). 6. Screw connection according to claim 5, d a d u r c h g e k e n n -z e i c h n e t that the sealing surface (2) together from the fitting piece (24) and the End (3) of the pipe section (1) is formed. 7 screw connection according to claim 6, d a d u r c h g e k e n n -z e i c h n e t X that the sealing surface (2X, 2 !!). in the T3 contact area of the end (3) and the fitting piece (24) has a groove (18) for a sealing ring (19). 8. Screw connection according to claim 7, d a d u r c h g e k e n n -z e i c h n e t that the space for the deformation of the sealing ring (19) increased Corner areas (26, 26t) of the groove (18, 18X) is located. 9. Screw connection according to one of claims 6 to 8, g e k e n n z e i c h n e t by an angle of about 370 between the pipe axis (20) and the sealing surface (2, 2 ', 22'). 10. Screw connection according to one or more of claims 1 to 9, d a d u r c h e k e n n n z e i c h n e t that the adapter (11) the end (9) of the pipe section (1) protrudes and a cylindrical inner surface (21) for encompassing the outer surface (22) of a pipe end (23). 11.Schraubverbindungs according to one or more of claims 1 to 10 that the adapter (11) or the pipe section (1) is designed as a pipe bend. 12. Screw connection according to one or more of claims 1 to 11, that the fitting piece (11), the pipe section (1) and / or the fitting (14) accommodates a hose nipple (33). 13. Screw connection according to claim 12, d a d u r c h g e k e n n -z e i c h n e t that the hose nipple (33) encompasses it and is attached to it having fixed retaining collar (35, 38). 14. Screw connection according to claim 13, g e k e n n z e i c h n e t d u r c h one between the retaining collar (35, 38) and the fitting piece (11), the pipe section (i) or the fitting (14) secured press socket (36). 15. Screw connection according to one of claims 12 to 14, g e -k e n n z e i h n e t d u r c h a support ring (39) at the end of the hose nipple the fitting piece (11) and the pipe section (1) or the fitting (14). 16. Screw connection according to one or more of claims 1 to 15, d u r c h e k e n n n z e i c h n e t, that its parts (1, 24, 11, 5, 33, 37, 39 14) consist at least partially of free cutting steel. 17. Hose connection according to one or more of claims 1 to 16, d u r c h e k e n n n z e i c h n e t, that its parts (1, 24, 11, 5, 33, 37, 39, 14) are at least partially turned parts. 18. Screw connection according to one or more of claims 1 to 17, d a d u r c h e k e n n n z e i c h n e t that the contact surfaces (25, 12, 16/17, 21/22, 37) are tightly fixed to the surface. 19. A method for producing a screw connection according to the claims 1 to 18, that is, that the individual parts are precisely fitted together and are connected to each other by copper brazing, 20. The method according to claim 19, d u r c h e k e n n -z e i c h n e t that prior to joining on the A copper solder paste is applied to contact surfaces. 21. The method according to any one of claims 19 to 20, g e k e n n -z e At least one cylinder-shaped and / or funnel-shaped widening is possible one of the ends of the fitting and / or pipe pieces before or during the assembly. 22. The method according to any one of claims 19 to 22, d a d u r c h g It is not noted that the grooves of the hose nipples are made by cold forming getting produced. 23. The method according to any one of claims 19 to 22, g e k e n n -z e i c h n e t d u r c h welding at least some of the individual parts by means of an outer fillet weld. 24. The method according to any one of claims 19 to 23, d a d u r c h g E k e n n n n e i n e t that a mounting piece with a uniform, opposite Conical shape and an even thread counterpart with the fitting piece and the Ub # union nut joined together and the pipe section is pressed in.