DE2421786C3 - Socket pipe connection for plastic pipes - Google Patents

Description

The invention relates to a socket pipe connection and a device for its production, as in The preamble of claims 1 and 2 is described

»5 and known from DT-Gbm 7 126342 and DL-PS 96102 is.

In the known socket pipe connection of this type (cf. DT-Gbm 7 126342), which is used as a connection nipple intended for sanitary furnishings

^ao hen, the sleeve end of the pipe has a uniform diameter over its entire length - except for the annular groove - and the sealing ring is fixed in the annular groove with an externally molded bead. The inside of the sealing ring has circumferential

^aJ fende sealing lips that fit sealingly against the smooth insert pipe that has been pushed in. This training allows a relatively simple and. uncomplicated assembly and may otherwise meet the requirements of the sanitary pipe connections. With this known socket pipe connection, however, the required seal can no longer be guaranteed under significant internal pressure, and in addition, if the plastic pipes connected to one another are not aligned, leaks and even damage to the sealing ring can occur.

In the case of a known socket pipe connection of another type (cf. DT-Gbm 7028914), the socketed Pipe end on two sections, namely one

♦ ° Section of larger diameter in which a Sealing ring is arranged, and a section further away from the pipe end, the inner diameter of which corresponds approximately to the outer diameter of the insert pipe. It is also with a socket pipe

♦ 5 connection of other genus known (see US-PS 3520541), the sealing ring with a smaller axial length than the end section of the sleeve and to be provided with an annular groove on its outer circumference, into which a clamping ring is

Jo attacks.

In the known device for making a socket pipe connection of which the invention goes out (see. DL-PS 96 102), the pipe end to be luffed is pushed over a mandrel, thereby puffed up and at the same time - without the use of an external tool - held on the mandrel by means of negative pressure. The annular groove is created by means of an elastic ring that can be turned out under axial compression shaped. This known device may be popular with many Applications may be suitable, however, with regard to the socket pipe connection according to the invention disadvantageous that it is not easily possible to use the clamping ring in the annular groove.

The invention is first of all the task of

^S 5 grunc'e to develop a socket pipe connection of the type mentioned in such a way that, with simple assembly, it is characterized by a perfect seal even under considerable internal pressure and also

among ile misalignments that are unavoidable in practice does not suffer any interference between the connected pipes. At the same time lies the invention the further object of the invention is to provide a device for producing such a socket pipe connection suitable is.

According to the invention, this object is achieved by the characterizing features of patent claims 1 and 2 solved. Another advantageous embodiment of the device according to claim 2 is the subject matter of claim 3.

The advantages achieved by the invention consist essentially in the fact that a socket pipe connection is specified which can be assembled in a simple manner, in particular without the disadvantageous rolling over of the sealing ring, and which is characterized by excellent sealing even under increased internal pressure. This is initially due to a self- tensioning effect that results from the tension ring provided according to the invention in conjunction with the special design of the sealing ring. The socket pipe connection according to the invention does not suffer from any misalignment between the connected pipes, which is unavoidable in practice, because due to this self-tensioning effect in the area of the clamping ring there is an over-ashing high sealing effect even with misalignment, and otherwise the pipes are in the area in which the inside diameter of the socket corresponds approximately to the outside diameter of the smooth plug-in pipe, directly support one another. The advantages achieved in terms of the device are above all that the production of socket pipe connections according to the invention is made possible in a particularly simple manner - the clamping ring not only has to be used separately, but also serves as a molding tool for the annular groove.

The invention is illustrated below with the aid of a drawing which merely shows exemplary embodiments explained in more detail. It shows

Fig. 1 shows the socketed pipe end of a socket pipe connection on average,

FIG. 2 shows different cross-sectional shapes of the one used in the socket pipe connection according to FIG. 1 Clamping ring,

3 shows a longitudinal section through a socket pipe connection with an inserted smooth plug-in pipe,

4a shows the socketed pipe end of a socket pipe connection in the course of manufacture with an inserted Spreader head in longitudinal section,

4b shows another embodiment of an expanding head in longitudinal section,

4c shows the object of FIG. 4b in cross section according to BB,

4d shows the middle part of the expansion head in the expanded state in cross section,

5 shows an expanding head with an external tool in a longitudinal section,

6 shows the object of FIG. 5 in cross section CC with the expanding head expanded and deformed,

Fig. 7 Irr the socketed pipe end of a socket pipe connection with an inserted press mandrel. Longitudinal section, and

Fig. 8 shows the socketed pipe end of a socket pipe connection with an inserted clamping ring and Sealing ring, in side view, partially cut.

First of all, FIG. 1 shows the socketed pipe end of a pipe joint. Mari recognize them undeformed pipe length 100, a conically extending transition part 101. an adjoining, the Sleeve section 102 facing away from the pipe end, the inner diameter of which is approximately the outer diameter of a smooth plug-in tube 110 to be pushed in (see FIG. 3) corresponds to another conical one Transition part 103 and finally an end section 104. The end section 104 has over its entire Length has the same inner diameter and is provided with an annular groove 105 in which a clamping ring 106 is arranged. The clamping ring 106 can have different cross-sections, shown for example in FIG. 2 have, wherein in particular hollow rings can also be used. By the way, it can The socketed pipe end shown is made separately and connected to a pipe section, for example be chained, it can also be produced directly by deforming the end of a pipe section will. The socket pipe connection shown is suitable

»° is suitable, for example, for plastic pipes made of vinyl, Polyethylene etc., also for so-called FRP pipes and pipe elbows. Both thermoplastic and Thermosetting plastics can also be used.

The clamping ring 106 is preferably made of stainless steel Metal, for example made of stainless steel, or made of the same material as the pipe socket. Depending on the circumstances, a single or multiple clamping rings can be used; that depends the pumped medium, the internal pressure, the required sealing and the shape of the clamping ring away.

Fig. 3 shows a complete socket pipe connection in the assembled state, in which in the socketed pipe end 101 to 104 a smooth plug-in pipe 110 is inserted. For sealing between the end section 104 of the socketed pipe end on the one hand and the plug-in pipe 110 on the other hand a homogeneous sealing ring 107 is provided

♦ o hen whose axial length is greater than its radial thickness. The sealing ring 107 lies on both sides of the annular groove 105 and thus the clamping ring 106 snugly against the inside of the end section 104. It also shows its part on its outer circumference an annular groove in which the clamping ring 106 engages.

The sealing ring 107 has an essentially rectangular cross section, the axial length of the sealing ring 107 - as already said - is greater than its radial thickness and also less than that Axial length of the end section 104.

The radial thickness of the clamping ring 106 is approximately a quarter of the difference between the inner diameters of the two sections 102 and 104 of the socketed pipe end. This generally prevents the sealing ring 107 from rolling properly, and the height of the clamping ring 106 may show certain deviations depending on its quality. The metal part Y of the sealing ring 107, firmly clamped between the clamping ring 106 and the insert tube 110, separates its two outer parts X, Z from one another in such a way that an axial deformation of one outer part cannot be transferred to the other outer part.

In Fig. 3, the socket pipe connection described with aligned pipe sections 100, 110 is shown, but it is also easily possible, like the stfichpuiikiici ic line 112 zeigi, pipe sections with a

A misalignment of up to 3 to 4 ° to be connected to one another in a sealing manner. The sealing ability of the compressed intermediate part Y of the sealing ring 107, which is held by the clamping ring 106, is very high, so that the sealing ability is retained even when the smooth plug-in pipe is inserted into the pipe socket with a misalignment of up to 3 to 4 ° . At the same time, the insertion tube 110, which is embedded in the section 102 lying in front of the end section 104, is prevented from being flattened. Moreover, through the opening 108 at the insertion end of the pipe socket, the correct position of the sealing ring 107 can be checked at any time and without the use of a test gauge or the like.

The socket pipe connection described is based on the idea that, on the one hand, there should be as wide a sealing surface as possible, i.e. that the sealing ring must lie against the inserted smooth plug-in pipe in a sealing manner over its entire width, and that on the other hand, it must be prevented that when the smooth plug-in pipe is pushed in, the The deformation occurring at the front part of the sealing ring from friction continues in its part which is back in the insertion direction in such a way that the sealing ring is rolled through the pipe end into the pipe socket. This is achieved in that - as explained - the sealing ring 107 with an essentially rectangular cross-section in its central part Y is acted upon from the outside by the clamping ring 106 in such a way that this central part Y does not deform the front (outside) outer part X against the ( inside) outside part Z can transfer. The socket pipe connection described is therefore based on a control of the expansion deformation of the entire sealing ring 107 from the outside due to the friction in the center area Y of the sealing ring 107.

When, when the smooth plug-in tube 110 is pushed in, its chamfered end 111 reaches the middle part Y of the sealing ring 107, it is first subjected to radial compressive stress, which is followed by axial tensile stress when the chamfered end 111 is pushed further, which leads to an axial deformation movement. It is important that due to the provided on the outer circumference of the sealing ring 107 the annular groove the central part Y of the sealing ring 'strength has 107 lower Radialst than the outer parts X, Z This configuration is important for the energy-related separation of the outer parts X, Z After the connection, that After the smooth plug-in tube 110 has been completely inserted, the axial tensile stress built up by friction in the middle part Y is converted into a self-tensioning force, which leads to a preferred sealing of the two outer parts X, Z with respect to the smooth plug-in tube 110.

An apparatus for producing the described socket-pipe connection is explained below with reference to FIGS. 4 to 6. The device consists mainly from an expanding head serving as a patrix. This expanding head has on the one hand on the front At the end of a spreading part 117 and on the other hand a pressure ring 116 'with a cylindrical outside. That Spreading part 117 is designed to be retractable, and between spreading part 117 and pressure ring 116 'is for molding of the groove 105 of the end section 104 of the lined pipe heated to the softening temperature a ring provided. To shape the outer wall of the socketed pipe end are divisible Forming dies 115, 116 provided, which encompass the end section of the tube.

The ring that forms the annular groove 105 is used

S the clamping ring 106. The expansion head carries a conical pressure piece 114, which vorschiebba in the axial direction and is retractable and the expanding part cooperating with the cone de pressure piece 114 117 carries. The pressure ring 116 'acts on the conical

ίο pressure piece 114 and on the clamping ring 106.

In detail, the first spread matrix forms

• 113 'the socket facing away from the pipe end cut 102, while the piece 114 through the conical pressure from the position shown in FIG. 4c in the Stel

¹ S treatment according to FIG. 4d spread spreading part 117 det end section 104 forms. Fig. 4a shows how dei clamping ring 106 held by a recess on the left side of the expansion part 117 and by Spreizunj the expansion part 117 on the inner wall of the Endab cut 104 is attached.

Fig. 4b shows how the clamping ring 106 is held by the middle part 113 of the expansion head and the dei Pressure ring 116 'is pushed forward to the right to the spread unc deformed expansion part 117. Included

¹ S the clamping ring 106 is pressed together in such a way that, if it is not exactly circular, this deviation is corrected. The molding die 115 is preferably designed in two to four parts, but the clamping ring 106 is on the inner wall of the end section 104 is fixed on the outer wall of the end section 104 by pressure from the outside. By pulling together the expansion part 117 the diameter of the first spreading die 113 'can be taken by the entire spreading head 113 from the pipe socket be pulled out.

If a pipe end to be luffed has a relatively small diameter, the fixation of the Clamping ring 106 can also be made without a molding die by taking advantage of the shrinkage during cooling will.

If the expansion part 117 does not do so when the pressure piece 114 moves back (to the left in the figures) is drawn in evenly, this can be supported by a spiral ring 118. Fig. 6 shows in the upper left quadrant the state in which the radius of the formed by the expansion part 117 Circle corresponds to the end section 104, while the upper right quadrant of this figure shows the state in which the expanding part 117 in the manner explained has moved in.

The clamping ring 106 is installed in support pieces 113c, which consist of two parts and over cylinders 113a and 113b are axially displaceable.

The conical pressure piece 114 on the pressure ring 116 '

can be advanced and retracted smoothly in the axial direction by operating the cylinders 113a and 1136. Becomes the conical pressure piece 114 advanced to the right, the pressure ring 116 'presses the inserted clamping ring 106 against the Rear side of the expanding part 117, the clamping ring 106 being brought into an exact circular ring shape.

If the expansion head 113 is inserted into a pipe socket which has been hardened in heat, the the end of the pipe facing away from the section 102, the end section 104 and the annular groove 105 formed as well The clamping ring 106 is fastened to the inner wall of the end section 104 in the region of the annular groove 105. How far the expansion head 113 is pushed in

which must be determined with the aid of an indicator 119 . The divisible molding die 115, which is acted upon from the outside, is guided on a plate 115 ' and has a molding surface for pressing the bottom of the annular groove 105 and the bend of the section 102 facing away from the pipe end, as can be seen in the figures. The special shape of the molding die 115 allows the inner material of the pipe to flow to a certain extent, so that a weakening of the wall thickness of the pipe socket can be prevented.

If the clamping ring 106 is stuck, the cylinders 113a and 1136 are actuated after a corresponding cooling time, so that the conical pressure piece 114 and the pressure ring 116 'are moved back (i.e. to the left in the figures) and the expansion part 117 is retracted until its outer diameter is smaller is than the bore of the clamping ring 106, whereupon the entire expansion head 113 can be pulled out of the pipe socket.

Fig. 7 shows another embodiment of a device for producing a socket pipe connection, which works with a pressing mandrel which, although not expandable, can easily consist of a more or less large number of sectors. The clamping ring 106 and a molding ring 121 can be combined with the molding or pressing mandrel 120 in such a way that the pipe socket is produced in the desired shape. It should be emphasized on this press mandrel 120 that the shaped ring 121 is formed by d <; n sealing ring 107 itself. If the press mandrel 120 is pulled out of the finished pipe socket, the shaped ring 121 can be turned around and placed on the clamping ring 106 so that it serves as a sealing ring 107, as has already been explained in detail.

Fig. S finally shows a sleeve end of the pipe, in which the cross section of the sealing ring 107 in particular Way is executed. It can be seen from the fact that the most varied of cross-sections for the sealing ring possible are.

In addition, the production of the socket pipe connection described is not limited to the application of the described device limited. On the one hand - as explained - such a pipe socket can be added subsequently be molded onto an already cured pipe using an expansion head. On the other hand, the Thermoplastic pipes can also be shaped while these pipes are still soft. In the case of pipes produced by injection molding, it is expedient to produce pipes and the socketed pipe end at the same time using corresponding external and internal shapes.

As explained, the perfect fit of the sealing ring 107 is guaranteed by the fact that the middle part Y is tensioned by the clamping ring 106 , so that a compressive stress occurring on the outside outer part X of the sealing ring 107 when the smooth plug-in tube 110 is pushed in does not affect the inside outer part Z on the other side of the clamping ring 106 can be transferred, so that in particular the formation of internal stresses or disadvantageous

Changes in the state of tension of the sealing ring 107 can be reliably prevented. Because of this, the push-in pressure when pushing in the smooth plug-in tube 110 can also be reduced. If, for example, with conventional,

»5 knew socket pipe connections of the necessary The pushing pressure for a 200 mm pipe is 50 kg and for a 500 mm pipe 100 kg, so that the production the connection by hand is practically impossible, is in a socket according to the invention

^ao pipe connection the insertion pressure for a 200 mm pipe is only 20 kg and for a 500 mm pipe only 40 kg. The result of this low insertion pressure is that no auxiliary equipment is required to

»5, according to the structure of the invention, to push the smooth plug-in pipe into the pipe socket, which can be done easily by hand. In addition, the tension ring 106 makes the movement of the sealing ring 107 so largely stable.

3 »lizes that the dimensional accuracy of the pipe sleeves only needs to be met with low requirements. For example, the tolerance values for a pipe socket according to the invention are ± 2.1 mm for a 200 mm pipe, ± 2.6 mm for a 300 mm pipe, ± 3.4 mm for a 400 mm pipe and ± 3.4 mm for a 500 mm pipe -mm pipe ± 3.9 mm. These results can be achieved with different cross-sectional shapes of the clamping ring 106 , which can for example be rectangular, polygonal, circular or semicircular in cross-section, but should generally be flat or convex on its surface facing the outer wall of the smooth plug-in tube to be inserted.

Only a tooth-like formation of this surface as a whole should be avoided. If the outside outer part X of the sealing ring 107 has the same or slightly larger inner diameter than the outer diameter of the smooth plug-in tube to be inserted (see FIG. 8), the sealing ring 10T can have different cross-sectional shapes without reducing the sealing ability.

In addition 7 sheets of drawings

Claims (3)

Patent claims: 1. socket pipe connection for plastic pipes, Consists of a tube with a socket at the end and a smooth plug-in tube that can be pushed into it and a homogeneous sealing ring arranged in the end area of the sleeve an axial length greater than the radial thickness, with the end section of the sleeve over the entire length is provided with the same inner diameter and an annular groove over the outwardly an annular collar is formed, the sealing ring on both sides of the annular groove full of the Inside of the end portion rests and is secured in position in the annular groove, marked by the application in a socket connection known per se with expanded in two sections Insertion opening, the section lying in front of the end section having the outer diameter of the smooth insert tube has approximately the corresponding inner diameter, and by the combination of the following Characteristics: a) the sealing ring (10) has an essentially rectangular cross section rr.it a known ring groove on the outer circumference, b) a clamping ring (J06) is mounted in the annular groove of the end section (104) of the socketed pipe end (100) , which engages in a known manner in the annular groove of the sealing ring (107) , c) the sealing ring (107) has, in a manner known per se, a shorter axial length than the end section (104) , d) the radial thickness of the clamping ring (106) is approximately equal to the quarter of the difference between the inner diameters of the two sections (104 and 102) of the sleeve end, e) the central part (10) firmly clamped between the clamping ring (106) and the insert tube (110) separates the two outer parts of the sealing ring (107) from one another in such a way that an axial deformation of one outer part cannot be transferred to the other outer part. 2. Device for producing a socket pipe connection according to claim 1, consisting of an expanding head serving as a male mold with a ring which is inserted between an expanding part at the front end and a pressure ring with a cylindrical outer side and which forms the groove of the end section of the socketed pipe heated to softening temperature, the expanding part is designed to be retractable, characterized in that the clamping ring (106) serves as the ring forming the groove (105) and a divided molding die (115, 116) encompassing the end section of the pipe is provided, that the expansion head has a conical pressure piece (114) which is axially Direction can be advanced and retracted , and carries the expanding part (117) cooperating with the cone of the pressure piece (1Ϊ4) and the pressure ring (U6 ' ) acts on the conical pressure piece (114) and the clamping ring (106). 3. Apparatus according to claim 2, characterized in that for shaping the section (102 ) lying in front of the end section (104) a shaping mandrel (113 ') is provided, which is arranged at the front end of the expanding head (113) in front of the expanding part (117) and has an outer diameter corresponding to the inner diameter of the section (102).