EP2090384A2 - Device for expanding conduits - Google Patents

Abstract

The device (1) has a base plate (5) fixed at a housing (3) of a press device (2). A cone (7) is axial movably held and swivelable around a longitudinal axis (X) in the base plate. The cone exhibits a cone point (8) that is brought in contact with an expanding head (21). The cone is axially distributed, where a partial unit (7a) of the cone supports the cone point and another partial unit (7b) is coupled with a positioning unit (4). The partial units are coupled with one another in an axially fixed manner and are swivelably supported relative to each other around the longitudinal axis.

Description

The present invention relates to a device for expanding tubes with a base body which is fixable to the housing of a pressing device, a rotatably and axially displaceably held in the base body about its longitudinal axis cone which is coupled at its one axial end portion with an actuating element of the pressing device and at its other end portion having a widening head engageable conical tip.

A device for expanding pipes of this type is for example from EP 16 74 241 A1 known. This device has an expandable in the radial direction expander, which is inserted into a tube to be expanded and then forced apart by the actuation of a pressing device. In order to avoid inhomogeneities on the inside of the pipe when expanding the pipe, a smoothing sleeve is inserted into the pipe to be expanded before the expansion head is inserted into the pipe. The smoothing sleeve should be an inhomogeneous Compensate force transmission from the segments to the inside of the pipe.

In this solution is considered disadvantageous that with the smoothing sleeve, an additional component must be introduced into the tube, which means an additional step. Furthermore, due to the smoothing sleeve, only indirect power transmission from the expander head to the tube takes place, which can lead to manufacturing inaccuracies.

Another device for expanding pipes is marketed by Uponor. This device has a rotary adapter with a base body which is screwed to the housing of the pressing device and carries on its opposite side a widening head. This consists of individual segments which are movable in the radial direction. The segments of the expander define a central tapered receptacle, in which engages the tip of an axially displaceable and rotatably held in the base body press cone. Upon actuation of the pressing device, the pressing cone is pressed into the expander head, so that its segments are pressed apart.

In order to compensate for inhomogeneities on the inside of the tube to be expanded, resulting from the fact that the segments of the expander are spaced apart in the circumferential direction during the expansion process, is at the known device of the expander respectively rotated upon retraction of the cone by a predetermined amount. This ensures that the force application points of the segments on the inside of the tube shift during each pressing step. Specifically, the cone in the body of the adapter via a freewheel so positively guided that it is rotated in the retraction movement by a defined amount. Furthermore, the expander head is coupled to the cone tip via entrainment means in such a way that the expander head is rotated during a rotation of the cone.

In this solution, it is sometimes considered disadvantageous that the inclusion of the press cone, in which the adjusting element engages, must always be greased during operation, so that the force acting upon retraction on the cone torque is not transmitted to the actuator of the pressing device. This torque could lead to loosening the screw between the body of the expansion adapter and the housing of the pressing device. For longer operating times, the device must be unscrewed as a check for re-greasing if necessary, which leads to delays in the workflow.

The object of the present invention is therefore to provide a low-maintenance device for expanding pipes, which provides a homogeneous tube expansion allows and at the same time manages without further aids.

The object is achieved in a device of the type mentioned above in that the cone is axially divided, wherein a first sub-element carries the conical tip and a second sub-element can be coupled to the actuating element, and wherein the two sub-elements coupled axially fixed to each other and relative to the longitudinal axis are rotatably mounted to each other.

In other words, the cone is axially divided into a first sub-element, which is in communication with the expansion head and is acted upon by a torque, and a second sub-element, which is coupled to the actuating element of the pressing device. Since the two sub-elements of the cone are rotatable relative to each other, the torque acting on the first sub-element is not transmitted to the second sub-element and thus not to the actuator of the pressing device.

One possibility of the rotatable mounting is to connect the two sub-elements of the cone by a sliding or rolling bearing. These can also transmit axial tensile forces. The tensile coupling of the two sub-elements ensures that they move together with axial displacement of a sub-element together.

In a manner known per se, the device according to the invention has a widening head which can be widened in the radial direction and which is rotatably fixed to the base body and which has a conical seat in which the conical tip engages.

A further embodiment of the device according to the invention can provide that the cone and the expander head are coupled by entrainment means in such a way that the expander head is rotated about the longitudinal axis during a rotation of the cone. By this means of entrainment is achieved that during a rotation of the cone of the expander is synchronously rotated and does not slip over the conical surface.

As entrainment is a in a recording of the cone, in particular the first part of the cone element movably held and elastically acted upon in the direction of the expander head pressure element in question.

Another possibility is to provide a held in an annular groove of the apex O-ring. O-rings have the advantage that they are easy to replace and represent very inexpensive wear agents.

Can also be used as a means of entrainment is held on the expander or at the apex magnet. The use of magnets has the advantage that these as non-mechanical driving means practically no wear.

It is also possible to provide any combination of resilient thrust pieces and magnets and O-rings as Mitnamemittel.

The device can also be configured in a known manner so that the cone is supported on the body by a freewheel with a frictionally held on the cone inner ring and a relative to this rotatable and axially displaceable on the inside of the body outer ring, wherein the freewheel rotation the inner ring relative to the outer sleeve allowed only in one direction, however, blocked in the opposite direction rotation. The freewheel is particularly designed so that it blocks during the backward movement of the cone. The arrangement of the freewheel in the interior of the body offers the advantage that as a result, the freewheel is largely protected from contamination.

The rotation of the cone can be effected by a mechanism provided in the device. For this purpose, the outer ring in the main body can be positively guided so that an axial movement of the outer ring also leads to a rotational movement of this. Such a positive guide can via a running in the outer ring of the freewheel oblique guide and one in this guide engaging pin can be realized, which is held in the body.

If the cone is moved axially in this embodiment, the freewheel is moved axially. The linear movement is implemented due to the positive guidance in a rotational movement of the outer ring. The cone is not rotated, since the inner ring of the freewheel is rotatable relative to the outer ring in the forward movement. When the cone is moved back, blocked the freewheel, with the result that caused by the forced operation rotation of the outer ring also causes a rotation of the cone and thus also associated with this expander.

In a further embodiment of the invention, the guide groove extends at its pointing to the pressing device end portion in the longitudinal direction of the base body and at its pointing to the apex end portion obliquely to the longitudinal direction. This type of forced operation ensures that the expansion head is pulled out during retraction of the actuator initially without rotation of the tube. Only when reaching the inclined part of the guide groove of the expander head is defined by the predetermined amount by the oblique groove rotated relative to the base body. As a result, the expander is rotated only when it no longer has contact with the pipe inside the pipe to be expanded and thus is freely rotatable.

Due to the positive guidance described above, it is possible to match the angle of the defined rotation to the width of the expansion segments. If the tube expansion is to be accomplished in only two steps, it is advantageous if the forced guidance causes a defined rotation of about half the width of an expansion segment. In this case, the press-in recess is located precisely between two expansion segments by a widening segment in the first widening step during the second widening process. Possibly in the first expansion step resulting inhomogeneities on the tube inside are largely eliminated by the second, rotated expansion step.

The defined rotation can also amount to a third, a quarter or a fifth of the width of a Aufweitsegments. In this case, the positive guidance can be matched to the width of the expansion segments, that, when the tube expansion is performed in X-steps, the rotation is 1 / x-th the width of a Aufweitsegments, where X is an integer between 2 and 20. A tube expansion with more than 20 steps is also possible, for example if the tube material is very sensitive to excessive strains in one step.

The invention further relates to a device for expanding tubes with a pressing device, the housing and an axially displaceably held therein actuator comprises a cone which is rotatably and axially displaceable relative to the housing about its longitudinal axis, wherein the cone is coupled at its pointing to the pressing device axial end portion with the actuator of the pressing device and at its other axial end portion has a conical tip, and one in radial Direction expandable and axially rotatable expander having a receptacle, in which engages the actuator, which is characterized in that the expander is fixed directly to the housing of the pressing device, and that the cone and the actuator axially fixed to each other and relative to the longitudinal axis relative are rotatably mounted to each other.

In this device, the expander head and the cone are mounted directly on the housing of the pressing device, resulting in a compact unit. In this case, the cone and the adjusting element are rotatably supported relative to one another about the longitudinal axis of the device, so that a torque acting on the cone tip is not transmitted to the adjusting element. The actuator may be a piston rod which engages in a receptacle of the cone and is held therein, for example by means of a sliding or rolling bearing.

Due to the axially fixed connection between the cone and the actuating element of the cone is automatically upon actuation of the pressing device together with the actuator moves, so that can be dispensed with return mechanisms.

A two-part design of the cone is not required in the alternative embodiment, since the rotational decoupling is done directly between the actuator and cone. As a result, no prestressed compression spring is necessary, which presses the cone when retracting the actuating element in the starting position, since the control element and cones are coupled tensile strength with each other.

Figur 1

eine Vorrichtung zum Aufweiten von Rohren gemäß der vorliegenden Erfindung in Vorderansicht,

Figur 2

die Vorrichtung aus Figur 1 im Schnitt entlang der Linie A-A,

Figur 3

die Vorrichtung aus Figur 1 im Betätigungszustand,

Figur 4

die Vorrichtung aus Figur 1 mit abgenommenem Grundkörper und Aufweitkopf in perspektivischer Ansicht,

Figur 5

eine weitere Ausführungsform einer erfindungsgemäßen Vorrichtung zum Aufweiten von Rohren im Längsschnitt, und

Figur 6

den Kegel der Vorrichtung aus Figur 5 in perspektivischer Ansicht.

With regard to further advantageous embodiments of the invention, reference is made to the dependent claims and the following description of exemplary embodiments with reference to the accompanying drawings. In the drawing shows

FIG. 1

a device for expanding tubes according to the present invention in front view,

FIG. 2

the device off FIG. 1 in section along the line AA,

FIG. 3

the device off FIG. 1 in the operating state,

FIG. 4

the device off FIG. 1 with removed body and expander in perspective view,

FIG. 5

a further embodiment of a device according to the invention for expanding tubes in longitudinal section, and

FIG. 6

the cone of the device FIG. 5 in perspective view.

In the FIGS. 1 to 4 a device for expanding tubes 1 according to the present invention is shown. The device comprises a pressing device 2 with a housing 3, in which an adjusting element 4 is guided axially displaceable. The actuator 4 has at its protruding from the housing 3 end a conical tip 4a.

The device further comprises an adapter element A with a base body 5, which is screwed onto a thread 6 of the housing 2. In the base body 5, a cone 7 is provided, which is axially displaceable in the base body 5 and is held rotatably about the longitudinal axis X of the device. The cone 7 is coupled at its one axial end region with the adjusting element 4 of the pressing device 2 and has a conical tip 8 at its other end region.

Like in the FIG. 2 is clearly visible, the cone 7 is axially divided and comprises a first sub-element 7a, which carries at one end the conical tip 8 and is provided on its opposite side with a receptacle 9, in which engages the second sub-element 7b. The second sub-element 7b has on its side facing the pressing device 2 a conical receptacle 10 in which the conical tip 4a of the adjusting element 4 engages.

Between the two sub-elements 7a and 7b, a rolling bearing 11 is installed, which ensures the free rotation of the sub-elements 7a and 7b against each other and this tensile strength coupled with each other.

The cone 7 is supported by a freewheel 16 on the base body 5. The freewheel 16 has an outer ring 17 which is rotatably supported in the main body 5 and axially displaceable. The freewheel 16 further includes an inner ring 18 which is non-positively connected to the cone tip 8 opposite, cylindrically executed end of the first part element 7a of the cone 7. The freewheel 16 is configured such that it allows rotation of the inner ring 18 relative to the outer sleeve 17 in one direction, while blocking rotation in the opposite direction.

The outer ring 17 of the freewheel 16 also has a positive guide, which determines the range of motion of the outer ring 17 in the base body 5. The positive guidance is provided by a guide groove 19 provided in the outer ring 17 and an engaging one in the main body 5 held pin 20 is formed. The guide groove 19 extends at its end pointing towards the pressing device 2 in the longitudinal direction X of the base body 5 and in its pointing to the apex 8 end portion obliquely to the longitudinal direction X. This ensures that the first sub-element 7a initially moves back when returning the cone 7 and only upon reaching the inclined portion of the guide groove 19 performs a rotational movement.

On the main body 5 an expander 21 is rotatably mounted by means of a union nut 22. The expander 21 consists, as in the FIG. 1 can be clearly seen, from individual expansion segments 23a, 23b, which together give a nearly circular cross-section. The individual segments 23a, 23b have on their outer side in each case a projection 24 which engages in an annular groove 25 of the union nut 22 and is held therein radially displaceable.

The expansion segments 23a, 23b form a central, conical receptacle 26, in which the conical tip 8 engages. The conical tip 8 and the expander head 21 are coupled together in such a way that a rotation of the first part element 7a of the cone 7 also leads to a rotation of the expander head 21. For this purpose, 8 corresponding driving means are provided at the apex. These include a held in a receptacle 30 of the apex 8 and resiliently biased in the direction of the expansion head 21 Pressure piece 27. Furthermore, a held in an annular groove 8a O-ring 28 is provided, which is in contact with the inside of the expansion segments 23a, 23b, wherein a torque transmission from the cone 7 on the expander by a frictional engagement between the O-ring 28 and the Expansion segments 23a, 23b is made possible.

Finally, a magnet 29 is provided on the apex 8, which makes a torque transmission to the expander 21 possible. It may well be sufficient to provide only one of the illustrated driving means.

In operation, the expansion head 21 of the device 1 according to the invention is introduced into a tube to be expanded. Subsequently, the pressing device 2 is actuated, whereby the adjusting element 4 of the in FIG. 2 illustrated starting position in the in FIG. 2 shown position is extended. Due to the axial movement of the adjusting element 4, the cone 7 is pressed against the restoring force of the compression spring 13 in the direction of the expansion head 21. In this case, the outer ring 17 is rotated due to the defined by the guide groove 19 and thus engaged pin 20 forced operation. This rotational movement does not transfer to the cone 7, since this can rotate freely through the freewheel 16 relative to the outer ring 17.

Due to the axial movement of the cone 7, the expansion segments 23a, 23b of the expansion head 21 are pressed apart and thereby the tube widened until the front Reversal point of the longitudinal movement of the actuating element 4 is reached (see FIG. 3 ).

Subsequently, the actuator 4 of the pressing device 2 is withdrawn. In this case, the cone 7 by the restoring force of the compression spring 13 back into the in FIG. 2 shown retracted initial position in which the cone 7 rests on the locking ring 15. In this movement, the outer ring 17 of the freewheel 16 due to the positive guidance performs a defined rotation, which runs in the opposite direction as the rotation, which it performs in the forward movement. Since the freewheel 16 blocks in this direction of rotation, the first subelement 7a of the cone 7 and thus also the expansion head 21 rotatably coupled to the conical tip 8 via the entrainment means 27, 28, 29 rotates. This rotational movement of the first partial element 7a is not transmitted to the second partial element 7b and thus also not to the adjusting element 4, since the second partial element 7b of the cone 7 is rotationally coupled via the rolling bearing 11 of the first partial element 7a.

As a result of the return movement of the cone 7, the segments 23a, 23b of the expander head 21 are moved back into their starting position, whereby the contact with the now widened tube inner wall is canceled.

As soon as the adjusting element 4 reaches its initial position, the direction of movement of the actuating element 4 returns around. The expansion process is repeated until the tube has expanded by the desired amount.

In the FIGS. 5 and 6 an alternative embodiment of a device 1 according to the invention for expanding tubes is shown. This device has the same basic structure as the previously described embodiment, with the proviso that the cone 7 is mounted on the freewheel 16 directly in the housing 3 of the pressing device 2 and the expansion head 21 is fixed directly to the housing 3 via the union nut 25. The adjusting element 4 of the pressing device 2 is designed here as a piston rod, which engages directly in a receptacle 31 of the integrally formed here cone 7 and is axially fixed about a roller bearing 11 and rotatably supported about the longitudinal axis X of the device 1.

In operation, the expander 21 of this device 1 is inserted into a tube to be expanded and the pressing device 2 is actuated, whereby the adjusting element 4 is advanced. The axial movement of the actuating element 4 causes the cone 7 is pressed into the expander 21 and this expands. The axial movement of the cone 7 also leads to an axial movement of the freewheel 16, the outer ring 17 performs a rotation due to the guided through the guide groove 19 and thus engaged, fixed to the housing 3 pin 20, forced operation. This is not transmitted to the cone 7 due to the rotatability of the freewheel 16, so that this is a pure axial movement performs. Upon retraction of the actuating element 4, the cone 7 is also retracted due to the axially fixed coupling caused by the rolling bearing 11. Again, the outer ring 17 performs a rotational movement in the opposite direction, which is transmitted due to the blocking of the freewheel 16 on the cone 7, so that it is also rotated together with the expander 21. The rotational movement 7 of the cone is not transferred to the adjusting element 4 of the pressing device 2, since this is drehdrekoppelt of the cone 7 via the rolling bearing 11.

Claims (14)

Device (1) for expanding tubes with a base body (5) which can be fixed to the housing (3) of a pressing device (2), a cone rotatably and axially displaceably held in the base body (5) about its longitudinal axis (X) 7) which can be coupled at its one axial end region to an actuating element (4) of the pressing device (2) and has at its other end region a conical tip (8) which can be brought into engagement with a widening head (21), characterized in that the cone ( 7) is axially divided, wherein a first sub-element (7a) carries the conical tip (8) and a second sub-element (7b) with the actuating element (4) can be coupled, and wherein the two sub-elements (7a, 7b) in particular by a sliding or a rolling bearing (11) axially fixed to each other and are rotatably mounted about the longitudinal axis (X) relative to each other. Apparatus according to claim 1, characterized in that the device can be expanded in the radial direction Expanding head (21) which is rotatably fixed to the base body (5) and which has a conical receptacle (26), in which the cone tip (8) engages, wherein the expander (21) in particular a plurality of expansion segments (23a, 23b ) having. Device according to one of the preceding claims, characterized in that the cone (7) and the expander head (21) are coupled by entrainment means in such a way that the expander head (21) rotates about the longitudinal axis (X) during rotation of the cone (7). is rotated, in particular the entrainment means in a receptacle (30) of the conical tip (8) movably held and elastically in the direction of the expander (21) acted upon pressure piece (27) and / or one in an annular groove (8 a) of the apex (8) held O-ring (28), and / or on the expansion head (21) and / or on the apex (8) held magnet (29). Device according to one of the preceding claims, characterized in that the cone (7) on the base body (5) by a freewheel (16) with an on the cone (7) non-positively held inner ring (18) and one with respect to the inner ring (18) to the longitudinal axis (X) is rotatably and axially displaceably supported on the inner side of the main body (5) by abutting outer ring (17), wherein the freewheel (16) permits rotation of the inner ring (18) relative to the outer ring (17) only in one direction, however, in the opposite direction a rotation blocked, in particular, the outer sleeve (17) is forcibly guided on the base body (5) such that an axial movement of the outer ring (17) also leads to a rotational movement of this. Apparatus according to claim 4, characterized in that in the outer ring (17) a guide groove (19) is formed, in which a in the base body (5) held pin (20) engages and in particular the guide groove (19) at its to the pressing device (2 ) pointing end portion in the longitudinal direction (X) of the base body (5) and at its to the cone tip (8) facing end portion obliquely to the longitudinal direction (X). Apparatus according to claim 2 and 4 or 5, characterized in that the positive guide causes a defined rotation of the expander (21) of 1 / X-th the width of a Aufweitsegments (23a), when the pipe expansion in X steps takes place, where X is a whole Number is between 2 and 20. Device (1) for expanding tubes with a pressing device (2), which has a housing (3) and an adjusting element (4) held axially displaceable therein, in particular in the form of a piston rod, a cone (7) which is opposite the housing (3 ) is held rotatably and axially displaceably about its longitudinal axis (X), the cone (7) being coupled to the setting element (4) of the pressing device (2) at its axial end region facing the pressing device (2) is and at its other axial end portion has a conical tip (8), and an expandable in the radial direction and axially rotatable expansion head (21) having a particular tapered receptacle (7c), in which engages the conical tip (8), characterized that the expander (21) directly to the housing (3) of the pressing device (2) is fixed, and that the cone (7) and the actuating element (30) axially coupled to one another and in particular by a sliding or a rolling bearing (11) to the longitudinal axis (X) are rotatably mounted relative to each other. Apparatus according to claim 7, characterized in that the expansion head (21) has a plurality of expansion segments (23a, 23b). Apparatus according to claim 8, characterized in that the cone (7) and the expansion head (21) are coupled by entrainment means in such a way that the expander head (21) is rotated about the longitudinal axis (X) during rotation of the cone (7) , wherein in particular the entrainment means in a receptacle (30) of the cone (7) movably held and elastically in the direction of the expander (21) acted upon pressure piece (27) and / or held in an annular groove (8 a) of the apex (8) O. Ring (28) and / or on the expansion head (21) or the cone (7) held magnet (29). Device according to one of claims 7 to 9, characterized in that the cone (7) on the housing (3) by a freewheel (16) with an on the cone (7) non-positively held inner ring (18) and one opposite to this about the longitudinal axis (X) rotatably and axially displaceably on the inside of the housing (3) adjacent outer ring (17) is supported, wherein the freewheel (16) allows rotation of the inner ring (18) relative to the outer ring (17) only in one direction, however the opposite direction blocks a rotation. Apparatus according to claim 10, characterized in that the outer ring (17) in the housing (3) is forcibly guided such that an axial movement of the outer ring (17) also leads to a rotational movement thereof. Apparatus according to claim 10 or 1, characterized in that in the outer ring (17) has a guide groove (19) is formed, in which a in the housing (3) held pin (20) engages. Apparatus according to claim 12, characterized in that the guide groove (19) in its to the pressing device (2) facing end portion in the longitudinal direction (X) of the housing (3) and at its to the cone tip (8) facing end portion obliquely to the longitudinal direction (X ) runs. Device according to one of claims 11 to 13, characterized in that the forced operation defines a defined Rotation of the expander (21) of 1 / X-th the width of a Aufweitsegments (23a) causes when the pipe expansion in X steps, where X is an integer between 2 and 20.

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