Four-die tool and forging press

Abstract

The invention relates to a four-die press tool (1), comprising a lower die assembly (4) and an upper die assembly (6) displaceable relative thereto, comprising four rams (10, 11, 12, 13) spaced apart and supported on the lower die assembly (4) or the upper die assembly (6) and carrying forging dies (29), and a ring (20) on which are mounted the four rams (10, 11, 12, 13) concentrically around the central press axis (28) of the four-die press tool (1) in such a way that they can be displaced relative to the central press axis (28) whenever the upper die assembly (6) is moved relative to the lower die assembly (4), wherein protecting means (35) are mounted on the ring (20) to secure a workpiece in a centered position on a central predetermined position of the workpiece relative to the central press axis (28) independently of a workpiece manipulator.

Claims

1. A four-die press tool adapted to be loaded by a manipulator with a workpiece, the tool comprising: a lower die assembly and an upper die assembly displaceable relative thereto and flanking a central press axis; four rams spaced apart and supported on the lower die assembly and the upper die assembly; respective forging dies carried on the rams; a ring on which the four rams are mounted concentrically around the central press axis of the four-die press tool in such a way that they can be displaced relative to the central press axis whenever the upper die assembly is moved relative to the lower die assembly; and protecting means on the ring, separate from and independent of the manipulator, and engageable with a workpiece for centering the workpiece in a predetermined position relative to the forging dies relative to the central press axis.

2. The four-die press tool according to claim 1, wherein the protecting means comprise a centering roller that centers the workpiece relative to the central press axis independently of the manipulator.

3. The four-die press tool according to claim 1, wherein the protecting means are mounted on the ring upstream and downstream of the rams along the central press axis.

4. The four-die press tool according to claim 1, wherein the protecting means are fixed relative to the central press axis.

5. The four-die press tool according to claim 1, wherein the protecting means are between the lower die assembly and the upper die assembly.

6. The four-die press tool according to claim 1, wherein at least one seat pocket is formed on the ring, a frame of the protecting means fitting in the pocket.

7. The four-die press tool according to claim 2, further comprising: a frame including a mount for the centering roller, the mount being removably fixed to the frame.

8. The four-die press tool according to claim 2, wherein the centering roller includes a body of rotation and includes on each end of the body at least one sealing groove that is concentric to the rotational axis of the body and that holds a metal seal ring.

9. The four-die press tool according to claim 1, wherein the four-die press tool is fixed by its upper die assembly to a movable crossbeam of the forging press.

10. The four-die press tool according to claim 1, wherein the forging dies are mounted so as to be fixed on but removable from the respective rams.

11. The four-die press tool according to claim 1, wherein the rams are mounted in an X-configuration centered on the axis.

12. An open-die forging press comprising a four-die press tool defining a central press axis for compressing and deforming a workpiece into an elongated semifinished product, and comprising at least one workpiece manipulator to deliver the workpiece to the four-die press tool, characterized by a four-die press tool according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Additional features, effects, and advantages of this invention are explained below based on the attached drawing and following description which present and describe, by way of example, a four-die press tool comprising protecting means that are attached directly to the tool's ring in order to secure independently of a workpiece manipulator a central predetermined position of a workpiece relative to a central press axis defined by the four-die press tool. In the drawing:

(2) FIG. 1 is a schematic front view of a four-die press tool in an open-die forging press seen in the forging direction of a workpiece to be forged along the central press axis of the four-die press tool, where protecting means in the form of two centering devices equipped with centering rollers are mounted directly on a ring of the four-die press tool;

(3) FIG. 2 is a schematic side view of the four-die press tool in FIG. 1; and

(4) FIG. 3 is a schematic partial sectional detail of the centering devices in FIGS. 1 and 2.

SPECIFIC DESCRIPTION OF THE INVENTION

(5) As shown in FIGS. 1 and 2, a forging press 2 in the form of an open-die forging press 3 is provided with a four-die press tool 1.

(6) The four-die press tool 1 includes a lower die assembly 4 fixed stationarily on a press table 5 of the forging press 2, as well as an upper die assembly 6 displaceable, that is movable relative to a lower die assembly 4, the upper die assembly being mounted fixed to a movable crossbeam 7 of the press 2.

(7) The upper die assembly 6 of the four-die press tool 1 is fixed to the crossbeam 7 of the press 2 is such a way that the upper die assembly 6 can be moved in a vertical forward direction 8 downward toward the lower die assembly 4 not exclusively by the crossbeam 7 in order to perform a forging operation in the standard manner. In fact, the upper die assembly 7 can also then be actively moved by the crossbeam 7 also in a vertical rearward direction 9 upward and away from the lower die assembly 4, thereby enabling any associated resetting devices to be eliminated, such as those typically used in the prior art. An additional source of problems with the four-die press tool 1 is eliminated simply by doing away with these resetting devices, which problems can cause an overall malfunction of the press 2, thereby ensuring a cumulative or, alternatively, longer repair-free service life for the four-die press tool 1.

(8) In addition, the four-die press tool 1 includes four rams 10, 11, 12, and 13 arranged in an X-configuration, of which the two upper rams 10 and 11 are each interactively connected to an upper 45° oblique element 14 and/or 15 of the lower die assembly 4, and of which the two lower rams 12 and 13 are each interactively connected to a lower 45° oblique element 16 and 17 of the upper die assembly 6. The vertical motions of the upper die assembly 6 are thus re-directed into four uniform individual motions of the rams 10, 11, 12, and 13.

(9) In addition, the four-die press tool 1 includes a ring 20 that supports and guides the four rams 10, 11 12, and 13, the ring being suspended on two lateral supports 21 and 22 in the four-die press tool 1 between the lower die assembly 4 and the upper die assembly 6.

(10) The supports 21 and 22 each have a wedge 23 and 24 each mounted so as to be movable on guides 25 (reference numeral here only by way of example) along the respective pairs of opposing 45° oblique elements 14 and 16, or 15 and 17 of the lower die assembly 4 and the upper die assembly 6. These wedges 23 and 24 are used, in particular, to compensate for vertical movements by the upper die assembly 6 of the four-die press tool 1 relative to the ring 20.

(11) The ring 20 includes a retaining and guide bushing 26 (reference numeral only by way of example) for each of the four rams 10, 11, 12, and 13, by which bushing rams 10, 11, 12, and 13 are guided by the ring 20 such that the free ends 27 (reference numeral only by way of example) of four rams 10, 11, 12, and 13 are arrayed concentrically about a central press axis 28, along which a workpiece W to be forged is moved.

(12) Actual forging dies 29 (also numbered only by way of example) that are used to forge the workpiece W are attached to free ends 27 of the rams 10, 11, 12, and 13 turned radially inward toward the central press axis 28, and are removably fixed so that they can be replaced.

(13) No additional frictional sliding surfaces exist between the dies 29 and the corresponding mounts for this purpose at ends 27 of the rams 10, 11, 12, and 13 due to the fact that the dies are fixed. This enables any additional sources of friction to be excluded from the four-die press tool 1, and this factor too enables a cumulative or, alternatively, longer repair-free service life to be achieved for the four-die press tool 1.

(14) Whenever the four-die press tool 1 is operating, the rams 10, 11, 12, and 13 are moved along a common line, specifically, the press axis 28, at the center of the ring 20 in order to appropriately work the workpiece W that is moved along the press axis 28. The return movement of the upper die assembly 6, as already described above is effected by the crossbeam 7 of the press 2, the four rams 10, 11, 12, and 13 and both wedges 23 and 24 being guided by clamping blocks 30 on the upper and lower die assemblies 4 and 6. As a result, the four rams 10, 11, 12, and 13, and both wedges 23 and 24 are returned to their starting position by the return movement 9 of the upper die assembly 6.

(15) In particular, slide plates 33 are also mounted between the 45° oblique elements 14, 15, 16, and 17, and the respective lower and upper die assemblies 4 and 6, these plates being sacrificial wear parts. These slide plates 33 are preferably employed on the four-die press tool 1 wherever substantial wear can be expected, for example, due to the action of high forces.

(16) According to the invention, means 35 are mounted on the ring 20 in order to center the workpiece W relative to the press axis 28 independently of any workpiece manipulator such as shown schematically at 45, this means 35 in this embodiment being specifically embodied as two centering devices 36 and 37 (see FIG. 2), of which the first centering device 36 is upstream in the forging direction S of the forging station in the ring 20, while the second centering device 37 is downstream of the forging station 38 in the ring 20. As a result, intermediate areas 39 and 40 are not obstructed between the four-die press tool 1 and workpiece manipulators 45 that are located and operate upstream or downstream of the press tool, by additional external guide devices (not shown), thereby enabling, for example, the workpiece manipulators 45 to move substantially closer to the four-die press tool 1 with the result that handling reliability can be significantly enhanced in terms of the workpiece W to be forged. An increase in handling reliability also results in a reduction in the danger of a workpiece W accidentally dropping between the two lower rams 12 or 13, thereby also enabling a longer repair-free service life to be achieved for the four-die press tool 1.

(17) Each centering device 36 and 37 includes a rotating centering roller 41 (reference numeral only by way of example) that can rotate about a rotational axis mounted transversely relative to the forging direction.

(18) In particular, the workpiece W can be centered by this centering roller 41 relative to the press axis 28 independently of one of the workpiece manipulators 45, thereby precluding the danger that the workpiece W can drop between the lower rams 12 and 13 if the workpiece W falls out of one of the workpiece manipulators 45.

(19) The centering devices 36 and 37 are integrated especially compactly into the four-die press tool 1 since space is created here for appropriate seat pockets 43 (reference numeral only by way of example) in the form of recesses into which a frame 44 (see also FIG. 3) of each centering device 36 and 37 can fit.

(20) A first embodiment of centering device 36 or 37 of protecting means 35 is shown by way of example in FIG. 3, and is described based on the upstream centering device 36 by way of example.

(21) The centering device 36 in this embodiment cannot be adjusted in height relative to its connection point on the four-die press tool 1, that is, relative to the ring 20. The device 36 instead is immediately displaced by a motion of the ring 20, thereby significantly simplifying the construction of the centering device 36.

(22) The device 36 is characterized, in particular, by a frame 44 that can be mounted on or removed from the ring 20 and that is a welded structure.

(23) A centering roller mount 44A can be hooked into this frame 44 on mounts provided on the ring 20, not shown here, by lateral brackets 44B (reference numeral only by way of example), and furthermore preferably bolted permanently onto the ring 20 by two unillustrated bolts. One advantage of this type of attachment is its ease of maintenance. As a result, only the bolts have to be loosened to replace the centering roller 41. If the ingot diameter of the workpiece W to be forged varies, centering should be adapted to the respective initial height. This is done simply by replacing the centering roller 41. Eight locating bushings 44C (four locating bushings per side) are inserted in the centering roller mount 44A that ensure a precise fastening location for upper bearing parts 44D (reference numeral only by way of example).

(24) The centering roller 41, which has the function of securing and guiding the workpiece W, is of concave shape and includes a shoulder 41A at its two ends (reference numeral only by way of example) that functions as a counter-rotation element for sliding ring elements 44E of centering roller mount 44A. In addition, sealing grooves 41C (reference numeral only by way of example) have been formed laterally into end faces 41B of the centering roller 41 to accommodate seal rings 41D so as to protect the bearings from accumulating contamination and scale. The bearings are further protected at the head end by covers 44F.

(25) The main function of the ring 20 is to center the rams 10, 11, 12, and 13 along a common line or on the press axis 28 in order also to prevent any relative motion by the dies 29, that is, the actual tools, relative to the workpiece W to be forged. Without this ring 20, the rams 10, 11, 12, and 13 would be able to move freely within the four-die press tool 1, with the result that no synchronous movement would occur on the part of the rams 10, 11, 12, and 13 relative to each other. The four-die press tool 1 would not be able to function under these circumstances. The four-die press tool 1, however, also provides other advantages over previous four-die press tools. For example, it protects sliding surfaces of the lower and upper die assemblies 4 and 6, especially, however, those of the lower die assembly 4, from direct heat from the workpiece W to be forged, as well as from falling scale.

(26) It must be explicitly emphasized here that the features of the solutions described above or described below can also be combined as required in order to implement or achieve the described features, effects, and advantages in corresponding cumulative fashion.

(27) It is of course understood that the embodiment described above relates only to one first embodiment of the four-die press tool according to the invention. The embodiment of the invention is therefore not limited to this illustrated embodiment.

(28) All of the features disclosed in the application documents are claimed as essential to the invention wherever they are new relative to the prior art, either individually or in combination.