US3747393A

US3747393A - Drop forging press

Info

Publication number: US3747393A
Application number: US00184698A
Authority: US
Inventors: H Robra
Original assignee: Schloemann AG
Current assignee: Schloemann AG
Priority date: 1970-09-29
Filing date: 1971-09-29
Publication date: 1973-07-24
Anticipated expiration: 1990-07-24

Abstract

A drop forging press has a fixed table support and a press frame comprising four columns, eight crosspieces and a plurality of tie members, the columns being of hollow polygonal cross-section, each column and being connected at its top and at its bottom to both adjacent columns by said crosspieces, the crosspieces being arranged, both at the top and at the bottom of the press frame in a rectangular configuration as seen in plan, two of said crosspieces overlapping at each end of each column, the tie members passing through each pair of overlapping crosspieces into the respective end of the respective column to secure the crosspieces to the column. Wedges may be interposed in the frame firmly to brace it. The table support may be supported by a bending support via a piston and cylinder unit. The press frame may be capable of moving up and down.

Description

[ July 24, 1973 3,581,656 6/1971 Pappas................................ 100/214 Primary Examiner-Charles W. Lanham Assistant ExaminerGene P. Crosby Attorney-Holman & Stern [57] ABSTRACT A drop forging press has a fixed table support and a press frame comprising four columns, eight crosspieces and a plurality of tie members, the columns being of hollow polygonal cross-section, each column and being connected at its top and at its bottom to both adjacent columns by said crosspieces, the crosspieces being arranged, both at the top and at the bottom of the press frame in a rectangular configuration as seen in plan, two of said crosspieces overlapping at each end of each column, the tie members passing through each pair of overlapping crosspieces into the respective end of the respective column to secure the crosspieces to the column. Wedges may be interposed in the frame firmly to brace it. The table support may be supported by a bending support via a piston and cylinder unit. The press frame may be capable of moving up and down.

14 Claims, 4 Drawing Figures 44 11 n mm 11 DROP FORGING PRESS Inventor: Helmut Robra, Mulheim, Ruhr,

Germany Assignee: Schloemann Aktiengesellschaft,

Dusseldorf, Germany Filed: Sept. 29, 1971 [21] Appl. No.: 184,698

Foreign Application Priority Data Sept. 29, 1970 Germany...................

Int. Field of Search....................

References Cited UNITED STATES PATENTS 11/1926 Jacobson 1/1934 Lindgren....... 4/1934 Sherman....... 10/1965 Hassellof.......

United States Patent Robra lllllll J PATENIEDJIJL24|975 3.141. 393

SHEET 2 [IF 3 E1 cl; 1

L -I HL IN V EN TOR HELMUT ROBRA DROP FORGING PRESS BACKGROUND OF THE INVENTION The present invention relates to a drop forging press which is of multi-cylinder construction, having a press frame composed of four columns, and a table support adapted to be fixed relative to earth. Although the forging stroke in such presses is essentially produced by hydraulic piston-cylinder units the presses are nonetheless commonly termed drop forging presses.

PRIOR TECHNIQUES Drop forging presses of medium to maximum capacity have hitherto been built conventionally with columns using cast steel components or with plates. The plate construction in the case of drop forging presses results in the press having a much lower moment of resistance or section modulus in a horizontal axis (the axis of the thickness of the plate) than in the dropforging axis when subjected to eccentric drop-forging impact stresses due to asymmetry of the workpiece. Particular measures must therefore be taken to improve this situation. This has been achieved in part by setting the bundles of plates crosswise or by the use of additional supports which are resistant to bending. However, in the case of the largest presses, transport difficulties preventthe plates from being made in one piece in the workshop; instead they must be welded on site, which is extremely costly.

Summary of The Invention According to the present invention there is provided a multi-cylinder drop forging press having a fixed table support and a press frame comprising four columns, eight crosspieces and a plurality of tie members, the columns being of hollow polygonal cross-section, each column being connected at its top and'at its bottom to both adjacent columns by said crosspieces, the crosspieces being arranged, both at the top and at the bottom of the press frame, in a rectangular configuration as seen in plan, two of said crosspieces overlapping at each end of each column, the tie members passing through each pair of overlapping crosspieces into the respective end of the respective column to secure the crosspieces to the column.

Preferably the press frame is able to move up and down.

Such a press can possess high mechanical rigidity in all directions of force. The components can be produced in the workshop and transported to the site using well wagons. The production riskis thus substantially lower and assembly may be effected using conventional heavy-duty hoisting gear. Since the press according to the present invention may be such that it can be dismantled at any time and the individual elements removed, components may be repaired more easily and at low cost. It is also a simpler matter to move the press from one location to another.

Preferably, a clamping plate is provided between the top end face of each column and the nearest crosspiece, each clamping plate carrying a wedge for each side face ofthe corresponding column, the wedge being movable to adjust the distance between the clamping plate and the crosspiece.

Preferably, in the press, which may be constructed above or below floor level, the arrangement is not such that a top crosshead carrying the top die is urged by means of piston and cylinder arrangements located between the top crosshead and the press frame against the table which carries the bottom die. On the contrary, the press frame, which would carry a die, would be moved relatively to the fixed table support with piston and cylinder arrangements acting between the base and the press frame.

A preferred embodiment of the invention is shown in the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view in part-section along the line I] of FIG. 2 of a drop forging press having a press frame above to move upwards and downwards;

FIG. 2 is a section along the line lI-II IN FIG. 1;

FIG. 3 is a connection between a column and bending supports shown in section; and

FIG. 4 is a plan view of a column of different designs from that shown in FIGS. 1 to 3.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 to 3 show a drop forging press of underfloor construction which extends into a foundation pit 1. It has a press frame composed of four columns 2 each of which as viewed in cross-section is a hollow, square, welded plate box. Four anti-bending crosspieces (i.e. stiffeners) 3, 4 are provided at each end of the columns and are arranged in a rectangle as seen in plan. An antibending crosspiece 4 (extending in a longitudinal direction) overlaps an anti-bending crosspiece 3 (extending in a transverse direction) at each end of the columns 2, the longitudinally extending anti-bending crosspieces 4 at the base of the press being arranged below the transverse anti-bending crosspieces 3, but at the top of the press, being arranged above the transverse crosspieces 3, as may be seen in FIG. 1.

The transverse crosspieces 3 as viewed in crosssection are rectangular, weld'ed plate boxes, within which two vertical plates 5 are arranged for greater rigidity. The longitudinal crosspieces 4 each take the form of a plate box which is open horizontally and transversally to the direction of its length and in which plates 6 are arranged vertically and transversally to the direction of the length of the longitudinal crosspieces 4, for reinforcement.

The columns 2 may be of the different type shown in FIG. 4. In FIG. 4, each column 2 has a main plate box which is divided into smaller plate boxes 10 by, internal walls 7 which extend in the direction'of the length of the column. The individual parts are held together by seam welding 8. This column composed of smaller boxes 10 possesses increased rigidity.

The connection of the column 2 with the transverse and

longitudinal crosspieces

3, 4 is effected, in all of FIGS. 1 to '4, by means of tie rods 9 each of which at one end is connected to a column, then extends through

twooverlapping crosspieces

3, 4 and terminates in a projecting end carrying a nut. On each of the eight corners of the press frame there are four tie rods 9. These tie rods are screwed into a plate 11. There are eight plates 11, one for each corner of the press frame, and each is welded to an end of a column 2.

The press frame, which is able to move up and down, rests on means for moving the frame up and down, here four extensible and retractable hydraulic units I2 mounted below it, only one of which units is illustrated in FIG. 1. The hydraulic units 12 are arranged between the base of the foundation pit 1 and the

lower crosspieces

3, 4, so separating the columns 2 from earth. The hydraulic units 12 which act on the transverse crosspieces 3 are differently constructed, or differently arranged, as the case may be, from those which act on the longitudinal crosspieces 4, as the transverse supports are located higher than the longitudinal ones.

It is also possible to locate the hydraulic units 12 outside the foundation pit on the floor, this being done in such a manner that they constitute an extension of the transverse crosspieces 3. The transverse crosspieces then protrude at both ends beyond the columns 2 and the protrusions abut the hydraulic units 12.

At'the center of the press frame and between the four columns 2, a table 13 is provided, at floor level. This table carries the lower die 14 of the press. The table 13 rests on a long table support 15 extending horizontally and parallel to the longitudinal crosspieces 4. The table support 15 is composed, in a manner not shown in detail, of a number of vertically arranged plates held together by screws. The table support 15 extends at both ends between two columns 2 and rests on the foundation through bearing members 16, whereby it is fixed relative to the base. The columns 2 are not directly fixed to the table support 15.

Below the table support 15 a transverse beam 17 is arranged crosswise so as to extend parallel to the transverse crosspieces 3. This beam 17 projects at both ends between a pair of columns 2 and also takes the form of a plate boxand is provided with centrally arranged plates 18 as reinforcements. Its function is to transmit the forces from piston and cylinder units 19, (described below), to the center of the table 13.

Four hydraulic piston and cylinder arrangements 19, 20 are provided and are arranged in each case between a pair of columns 2, two piston and cylinder arrangements 19 being located each on a lower transverse crosspiece 3 and two piston and cylinder arrangements 20, each on a lower longitudinal crosspiece 4. One pair of piston and cylinder arrangements 19 acts at the top of the table support 15 while the other acts on the

crosspieces

3, 4, whereby, upon actuation, the arrangements 19, 20 move the press frame relative to the fixed table support 15.

' At the top, within the press frame, a transverse beam 21 is provided between the transverse crosspieces 3 and projects at both ends below the longitudinal crosspiece 4. This transverse beam 21 is composed of a plurality of T-section cast steel beams 22', the l section in effect being a double T, so that the transverse beam is subject only to slight flexure. The transverse beam 21 carries on its lower side an upper die 23.

As shown in FIG. 3, a four-sided clamping plate 24 is arranged on each plate 11 and has on each side an upwardly extending lug 25. On each of these lugs 25 there is mounted a hydraulic unit 26, the piston of which is able to press against a wedge 27 located on the clamping plate 24. There is one wedge 27 for each side face of each column 2. The sloping face of the wedge 27 abuts against the sloping face of a wedge plate 28 provided on the underside of one of the transverse crosspieces 3. The wedges 27 are held in place either by means of a mechanical bolt system or by designing the wedge to be of a small enough angle to be frictionally self-locking.

If the hydraulic units 12 are actuated so that the whole press frame moves upwards, the upper die 23 moves into a position, relative to the lower die 14, which is fixed relative to the base of the foundation pit l, in which the dies 23, 14 are able to receive a workpiece. If the piston and cylinder arrangements 19, 20 are then actuated, the press frame is caused to move downwards and a workpiece may be formed between the dies 23 and 14. The piston and cylinder arrangements 19, 20 can be actuated to pre-stress the press frame or can over-stress the press frame in use, so that a gap may occur between the columns 2 and the transverse crosspieces 3. When a gap of this kind is formed, the wedges 27 are inserted by the hydraulic units 26 so that there is always a firm brace between the columns 2 and the

crosspieces

3, 4.

Because of its size, the press is of multi-cylinder construction. The columns 2 are hollow and have four or more sides, not in practice being of triangular section, because they would not be rigid enough.

The advantage of disposing the cylinders of the arrangements 19, 20 uppermost, with the pistons below, is that the space between the columns 2 is better utilized, and the pistons can abut a narrower crosspiece than a cylinder could abut.

The I-section beams 22 comprising the transverse beam 21 have level lower surfaces but arched upper surfaces, such that the I is of the height shown in section in FIG. 1. for most of the space between parallel upper crosspieces 4, but slopes down to alower level at each end, where it supports the longitudinal crosspieces 4.

I claim:

1. A drop forging press having a fixed table support and a press frame comprising four columns, eight crosspieces and a plurality of tie members, the columns being of hollow polygonal cross-section, each column being connected at its top and at its bottom to both adjacent columns by said crosspieces, the crosspieces being arranged, both at the top and at the bottom of the press frame, in a rectangular configuration as seen in plan, two of said crosspiece) over-lapping at each end of each column, the tie members passing through each pair of overlapping crosspieces into the respective end of the respective column to secure the crosspieces to the column, the press being of multi-cylinder construction.

2. A drop forging press as claimed in claim 1, wherein each column is a rectangle incross-section, the rectangle being composed of four smaller rectangles which extend side-by-side in the direction of the length of the column.

3. A drop forging press as claimed in claim 1, wherein each column carries, on each end face, a plate into which four said tie members are screwed.

4. A drop forging press as claimed in claim 1, wherein a clamping plate is provided between the top end face of each column and the nearest crosspiece, each clamping plate carrying a wedge for each side face of the corresponding column, the wedge being movable to adjust the distance between the clamping plate and the said crosspiece. i

5. A drop forging press as claimed in claim 4, wherein the wedges have a wedge angle chosen to make them frictionally self-locking.

6. A drop forging press as claimed in claim 4, wherein the wedges are hydraulically actuated.

7. A drop forging press as claimed in claim 1, comprising means below the press frame to move the press frame up and down.

8. A drop forging press as claimed in claim 7, further comprising a piston and cylinder arrangement disposed between every pair of columns of the press frame to operatively connect the table support with respect to one of the crosspieces.

9. A drop forging press as claimed in claim 8, wherein at least some of the piston and cylinder arrangements abut the table support, which support is fixed above the piston and cylinder arrangements and projects between the columns.

10. A drop forging press as claimed in claim 9, wherein a transverse beam is provided supporting the table support and arranged cross-wise below it, the beam abutting the remainder of the piston and cylinder arrangements and projecting between the columns perpendicularly to the table support.

11. A drop forging press as claimed in claim 9, wherein at least one piston and cylinder arrangement is disposed with the cylinder uppermost and the piston directed downwards.

12. A drop forging press as claimed in claim I, wherein a transverse beam is provided for supporting the upper die of the press and is composed of a plurality of T-section beams.

13. A drop forging press as claimed in claim 1, wherein each column is a square-section welded boxgirder.

14. A drop forging press as claimed in claim 1, wherein a transverse beam is provided for supporting the upper die of the press and is composed of a plurality of I-section beams.

Claims

1. A drop forging press having a fixed table support and a press frame comprising four columns, eight crosspieces and a plurality of tie members, the columns being of hollow polygonal crosssection, each column being connected at its top and at its bottom to both adjacent columns by said crosspieces, the crosspieces being arranged, both at the top and at the bottom of the press frame, in a rectangular configuration as seen in plan, two of said crosspiece) over-lapping at each end of each column, the tie members passing through each pair of overlapping crosspieces into the respective end of the respective column to secure the crosspieces to the column, the press being of multi-cylinder construction.

2. A drop forging press as claimed in claim 1, wherein each column is a rectangle in cross-section, the rectangle being composed of four smaller rectangles which extend side-by-side in the direction of the length of the column.

4. A drop forging press as claimed in claim 1, wherein a clamping plate is provided between the top end face of each column and the nearest crosspiece, each clamping plate carrying a wedge for each side face of the corresponding column, the wedge being movable to adjust the distance between the clamping plate and the said crosspiece.

12. A drop forging press as claimed in claim 1, wherein a transverse beam is provided for supporting the upper die of the press and is composed of a plurality of T-section beams.

13. A drop forging press as claimed in claim 1, wherein each column is a square-section welded box-girder.