Press tool

The invention relates to a press tool, in particular for Connecting tubular workpieces, with compression jaws, the thus are movable relative to each other that they to be placed the workpiece can be opened and that they go along with pressing end complement towards a closed press space, and with a Drive means for moving the cheek plates in the pressing direction, wherein one of the cheek plates than on the workpiece attachable formed abutment and arranged on a bracket is located at the free end of the die and supported on one side pivotally and opposite to the Page releasably lockable or is. (US-A-4528740)

To connect the pipe ends coupling sleeves are used which are plastically deformable and made from metal, preferably from Steel. Its inside diameter is so much larger than the outer diameter of the pipe ends to be joined, that they at radial compressibility to abut the shell surface the tube ends are permanently deformed. After DE-PS 1 187 87⊘ can such coupling sleeves on their inside in the vicinity of each end, in addition have an annular groove, in which an elastic sealing ring is inserted.

Dies are provided for the radial compression, as are known for example from DE-PS 21 36 782nd This pressing tool has two each with two arms formed Clamping jaws, of which at least one pivotally mounted to the Press tool is mounted. The cheek plates have circular arc portions forming pressure surfaces on with equal radii Include a baling chamber. Instead of a circular arc portions the pressing surfaces also be contoured to example to form a polygonal or oval baling chamber.

The press room the distant arms of the cheek plates can are spread against the action of a spring, with the result that the press jaws in the region of the baling chamber is moved to today will. The spreading is done by means arranged side by side and abutting pressure rollers together by means of a drive device in the form of a working cylinder be driven between the arms and in this way the Cheek plates pivot.

A further development of this press tool is described in DE-OS 34 23 283 describes. In this press tool are two pressing jaws provided that each pivotable on a drive lever are mounted, which in turn pivotally mounted on the pressing tool are performed. The drive lever have opposed Arms which by means of a working cylinder in the space retractable press wheels can be spread and to Thus, to move the cheek plates together. The press jaws are additionally performed so in scenes that it to the pivoting of the drive lever in the opening direction their articulation points are pivoted to the driving levers, so that between the end faces of the cheek plates a wide, mouth-like Opening is created, connecting to the inclusion of Pipe ends and a coupling sleeve easier.

be Upon pivoting the drive lever in the opposite direction the jaws pivoted back so that the bisectors each other fall on their arc sections about and the jaws during the further pivoting of the drive lever be moved parallel to today. During the pressing process the jaws are further moved toward each other until they include a circular area on the pressing end and thereby the Pipe ends and the coupling sleeve in accordance with reduction in diameter have deformed.

In US-A-4 528 74⊘ is a generic pressing tool Connecting nested tube ends disclosed in the a semi-circular pressing jaw by means of a punch in the axial Direction movable against another, semicircular pressing jaw is. The other press jaw forms a kind of abutment. This press jaw is arranged on a bracket, which on one side is pivotally mounted and on the opposite Page releasably lockable or is. To prepare the press tool to the pipe end, the bow in the direction of opening pivoted and can be closed after preparation.

These dies have proven desirable if a not for demanded large diameter reduction or engagement depth becomes. For larger offsets that are then required when the pipe connection is to withstand higher internal pressures, it is advisable to provide more than two press jaws, thus it between the end faces of the cheek plates not to Forming outwardly projecting webs coming, which you would prevent complete closing of the pressing jaws. Such dies are for example in the DE-OS 21 18 25 11 942 and DE-AS 19 ⊘7 956 described 782, DE-OS 35 13 129, DE-AS. Allen disclosed therein pressing tools have in common that all pressing jaws and movable in the radial direction are performed. This requires elaborate guides and drive means, whereby the dies hard and therefore are difficult to handle and also expensive.

Also in the US-A-3,276,238 is a press tool with three press jaws disclosed. Two of the cheek plates are facing each other in a V-shape Guide surfaces slidably mounted. apart from the fact that the pressing tool is manually operated, it is in the Pressing a retaining ring on a pipe end is not openable formed and therefore not suitable, two pipes or a pipe to connect to a press fitting.

The invention is based on the object of a press tool to make the aforementioned type so that, in spite of the arrangement of more than two press jaws as simple and thus easy to handle and inexpensive to produce formed is.

This object is achieved in that more than two compression jaws are present, two compression jaws on V-shaped to each other guide surfaces, against which the press jaws externally supported, guided in such displaceable are that they are to the pressing continuously towards move the center of the baling chamber. This press tool features Despite the array of more than two press jaws by simple Construction of. Also, the operability is by the provision of not affected by more than two pressing jaws, since the Curved structure and thus retain the lightweight openability has been. By pressing device according to the invention can be greater achieve offsets.

In development of the invention it is provided that the press jaws having circumferentially equally long arc segments, the gaps between the respective opposite end faces the pressing jaws are thus uniformly distributed over the circumference.

When three press jaws are provided, the movement directions should the two movable pressing jaws an angle of 6⊘ ° include the symmetry to the center line perpendicular to the abutment located and opens from this face away. at four pressing jaws, the movement directions of the two should the Abutment adjacent press jaws during the pressing an angle of 9⊘ ° include the symmetrical to the mid-perpendicular located on the abutment and opens from this face away.

In a further embodiment of the invention provides that the movable pressing jaws on the one hand by their directions of movement predetermining guide means and secondly to a movable towards the abutment ram bear, the connected to the drive means is displaceable and on which the compression jaws adjoining the abutment are supported. There is the possibility that between the press ram movable pressing jaws another Cheek plate on ram abuts or is connected to is facing the abutment. The ram is Part of the drive means and may for example as formed or hydraulic cylinder connected to such be. Instead of such a press ram can for each mobile provided press jaw own drive means be, for example, again in each case a hydraulic cylinder. This may include a pressing or Zugstempel.

In the drawing, the invention is by way of example illustrated in more detail. Show it:<dl tsize="8"><dt>figure 1</dt><dd>a press tool in the open position and</dd><dt>figure 2</dt><dd>the mold according to Figure (1) in Closed position.</dd></dl>

In Figures 1 and 2, a press tool 1 is shown, and Although the upper headboard. It has a tool housing 2 on which is formed hollow and downwardly initially widens and then tapers. In the central region has it on a U-shaped recess. 3

The free ends of the recess 3 are by an abutment bracket 4. The abutment bracket 4 is at its in this View right to a bearing pin 5 pivotally mounted. On the left side in this view is the abutment bracket 4 via a locking pin 6 in the position shown fixed. This locking pin 6 passes through corresponding recesses in the tool housing 2 and the abutment 4 and can easily be removed. After its removal, the abutment bracket 4 about the bearing pin 5 in the directions of the double arrow A. be pivoted, in the clockwise direction so far that the Recess 3 is completely open at the top.

On the inside of the abutment bracket 4 has a pressing surface 7, has a circular arc shape and symmetry through an angle of 12⊘ ° extends to the longitudinal axis of the die. 1 The pressing surface 7 has a groove extending in the circumferential direction, inside open groove. You can interchangeably attached to the abutment bracket 4 be.

Inside the tool housing 2 extending oblique guide surfaces 8, 9, enclose an angle of 6⊘ ° and mirror symmetry to the longitudinal axis of the die. 1 To the Guide surfaces 8, 9 are each a press jaw 1⊘, 11, and via correspondingly inclined bearing surfaces 12, 13. The cheek plates 1⊘, 11 are also symmetrical to the longitudinal axis of the die 1 is formed and each have a pressing surface 14, 15, each of the over 12⊘ ° extending Arc portions are formed. On the inside is also in they formed a circumferential groove. The circular arc portions all press surfaces 7, 14, 15 have identical radii. The Pressing jaws 1⊘, 11 protrude below each other in a horizontal and transverse extending to the longitudinal axis of the die 1 guide 16 in that formed in the head 17 of a pressing die 18 is. The undersides of the pressing jaws 1⊘, 11 also extend horizontal, so that the pressing jaws 1⊘, 11 in the groove 16 transverse to the out longitudinal axis of the die 1 slidably in the groove 16 are, after the manner of a dovetail guide a form fit.

In the lower portions of the press jaws 1⊘, 11 are transversely extending blind holes 19, 2⊘ formed coaxially to each other. In these blind holes 19, is a 2⊘ Compression spring 21 is inserted, which seeks the cheek plates 1⊘, 11 outwardly and thus the abutment surfaces 12, 13 to the Guide faces 8 to press. 9 The ram 18 is vertically along the longitudinal axis of the die 1 (Double arrow B) mounted in a linearly movable. He is a pneumatically or hydraulically operated working cylinder operated, which is not shown here.

First, the latch for the use of the die 1 the abutment bracket 4 achieved by means of the locking pin 6, ie this locking pin 6 is pulled out and the abutment bracket 4 pivoted so far clockwise until the bifurcated Opening of the recess 3 is completely free. simultaneously is the punch 18 in a retracted downwards Sellung. The mold 1 can then at a Coupling sleeve 22 are recognized so that the coupling sleeve 22 perpendicular to the plane through the recess 3 extends and is received by the latter. Then, the Abutment 4 pivot about the coupling sleeve 22 and by Insertion of the locking bolt 6 is locked. The coupling sleeve 22 is then enclosed by the press tool. 1

The press jaws 1⊘, 11 are then by raising the pressure ram 18 placed on the coupling sleeve 23 to rest. Since its radius is smaller by the intended depth of pressing than the radius the coupling sleeve 22 prior to compression, are the pressing surfaces 7, 14, 15 only with their outer transverse edges at the periphery the coupling sleeve on 22nd Between the end faces of the press jaws 1⊘, 11 and the abutment bracket 4 are still free column 23, 24, 25, which are the same size. The radii of the circular arc portions the pressing surfaces 7, 14, 15 go from mid-points, which lie in the vertices of an equilateral triangle.

Through further pressurization is now the punch 18 moved up. The press jaws 1⊘, 11 slide it over their contact surfaces 12, 13 over the guide faces 8, 9, whereby them extending in the directions of the double arrows C, D Movement direction is impressed. The two directions of movement include the same angle as the guide surfaces 8, 9, ie 6⊘ °. The cheek plates slide 1⊘, 11 in the groove 16 of the punch 18 simultaneously horizontally toward towards each other, against the action of compression spring 21. In this manner the coupling sleeve 22 is radially compressed, ie in its diameter to the desired depth of pressing reduced. At the pressing end of the pressing surfaces is 7, 14, 15, a circular pressing space included and have the Column 23, 24, 25 is reduced to zero.

For the removal of the press tool 1 of the coupling sleeve 22 18 is moved back to the ram. The abutment bracket 4 is pivoted away, after removal of the locking pin 6 so that then the press tool 1 can be taken away.