US3158046A

US3158046A - Hydraulic forging press

Info

Publication number: US3158046A
Application number: US30268A
Authority: US
Inventors: Steinfort Ewald; Hertl Albert
Original assignee: Hydraulik GmbH
Current assignee: Hydraulik GmbH
Priority date: 1959-05-20
Filing date: 1960-05-19
Publication date: 1964-11-24
Anticipated expiration: 1981-11-24
Also published as: DE1145462B; GB907933A

Description

Nov. 24, 1964 E. sTElNFoRT ETAL 3,158,046

HYDRAULIC FoRGING PRESS Filed May 19, 1950 l 7 Sheets-Sheet 1 r fr V/ l IAL/ENOES;

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E g C fv/'fiar Har Hrran/vsy United States Patent O 3,153,046 HYDRAULIC F RGING PRESS Ewald Steinfurt, Dusseldorf, and Albert Hertl, Duisburg, Germany, assignors to Hydraulik G.m.b.H., Duisburg, Germany Filed May 19, 1%0, Ser. No. 30,268 (Ilaims priority, application Germany, May 2i), 1959, H 36,427 12 Claims. (Cl. '7S- 13) The present invention relates to hydraulic forging presses in general, and more particularly to improvements in a hydraulic forging press of the underground type in which certain components including the upper crosshead which supports the upper die, the uprights, and the lower crosshead are reciprocable with respect to the stationary die carrier.

In certain types of known underground forging presses, the stationary die carrier is mounted on a foundation and supports two or more press cylinders whose pistons act against the lower crosshead to thereby reciprocate the upper crosshead with the movable die toward and away from the stationary die. The two crossheads are connected by a plurality of uprights which are often sub- 'ected to very high bending stresses, such bending stresses developing as a result of eccentric forces generated during certain forging operations. In other words, all uprights are not always subjected to equal tensioning forces which results'in an inclination of the upper crosshead so that the latter subjects the guide sleeves of the uprights to very high end pressures. The bending forces acting upon the deformed uprights are often higher than the axial forces; this results in excessive wear upon the uprights. Consequently, the uprights of conventional forging presses must be dimensioned with a view to prevent their bending, i.e. the dimensions of such uprights are much larger than if the uprights were subjected only to axial stresses.

An important object of the present invention is to provide a hydraulic forging press in which the uprights are relieved of all or nearly all bending stresses and in which the uprights must be dimensioned only with a view to take up axial stresses.

Another object of the invention is to provide a hydraulic forging press of the above outlined characteristics in which the uprights are subjected to greatly reduced wear and tear and in which a danger of deforming or breaking the uprights is eliminated despite the fact that the uprights are lighter than in equivalent forging presses of known design.

A further object of the invention is to provide a hydraulic forging press which embodies a novel arrangement capable of taking up all bending stresses such as act upon uprights in the presses of presently utilized design.

A concomitant object of the instant invention is to provide a forging press in which the arrangement utilized for taking up the bending stresses simultaneously acts as a means for reciprocating the movable die with respect to the stationary die.

Still another object of the invention is to provide a hydraulic forging press of the above outlined characteristics which is particularly useful for olf-center forging and in which the uprights need not guide the movable die on its way toward and away from the stationary die but merely take up axial stresses which arise during the forging operation. j

With the above objects in view, the invention resides in the provision of a hydraulic forging press which comprises essentially a stationary die carrier or socket mounted on a suitable foundation and preferably above 33,158,046 l"a.tented Nov. 24, i964 a compartment defined by the foundation, two crossheads disposed at the opposite sides of the carrier, i.e. above and below said carrier and connected with each other by a plurality of parallel vertical uprights or columns which are slidable through suitable bores formed in the stationary carrier so that the crossheads and the uprights may be reciprocated with respect to the carrier, and means connected with the carrier and preferably with the lower crosshead for guiding the lower crosshead and hence also the upper crosshead during the latters movements toward and away from the carrier. The movable die is connected with the upper crosshead and the uprights take up only axial stresses because all other stresses, particularly bending stresses, are taken up by the improved guide means which acts between one of thecrossheads and the stationary carrier.

The improved guide means may consist of one or more vertical guide shafts connected with the stationary carrier and slidably receivable in suitable bushings provided in the lower crosshead. If the press embodies a single guide shaft, the latter is preferably mounted in the center of the carrier but itis equally possible to utilize two or more guidev shafts Iand to provide on one of the crossheads, preferably on the lower crosshead, one or more cylinders which receive the respective guide shafts so that the latter simultaneously perform the function of press pistons, i.e. they shift the movable die toward the stationary die. When the guide shafts are utilized as press pistons, it is advisable to provide at least one shaft with a coaxial guide extension of smaller diameter which projects through the end wall of the respective cylinder on the lower crosshead -so that the lower crosshead is guided not only by the guide shaft or shafts but also by the extension or extensions of such guide shafts.

The improved press utilizing one or more guide shafts and suitable bushings which are slidably guided along such shafts is subjected to lesser wear and tear, and particularly the uprights are completely relieved of any bending stresses. In addition, and since the uprights need not guide the movable die on its way toward and away from the stationary die, the exterior of such uprights need not be finished with great precision which also contributes to lower cost of our improved forging i press. Of course, additional important savings result from the fact that the cross-sectional areas of uprights must be calculated merely by consideration of axial forces since all or at least most bending stresses are taken up by the guide means which acts between the lower crosshead and the stationary die carrier.

The novel features which are considered as characterstic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of two specific embodiments when read in connection with the accompanying drawings, in which:

FIGS. la and lb together illustrate a central Vertical section through a hydraulic forging press and the hydraulic supply and control system therefore embodying one form of our invention, the section through the press being taken along the line A-B of FIG. 3, as seen in the direction of arrows;

FIG. 2 is another vertical section through the press with the hydraulic system omitted, the section being taken along the line C-D of FIG. 3, as seenin the direction of arrows;

FIG. 3 is a horizontal section through the stationary die carrier as seen in the direction of arrows from the line E-F of FIG. 1 or 2;

FIGS. 4a and 4b together illustrate a central vertical section through a modified hydraulic forging press and the hydraulic supply and control system therefor, the section through the press being taken along the line A-B of FIG. 6, as seen in the direction of arrows;

FIG. is another vertical section through the press of FIG. 4 as seen in the direction of arrows from the line C-D of FIG. 6; and

FIG. 6 is a horizontal section through the stationary die carrier as seen in the direction of arrows from the line ELF of FIG. 4 or 5.

Referring now in greater detail to the illustrated embodiments, and iirst to FIGS. la and 1b, there is shown a hydraulic forging press of the underground type, the

`press comprising a horizontal stationary die carrier or socket 1 which is placed onto the foundation 1A and which supports a slidable table 1a for the stationary lower die 1b. Three guide means including two vertical press pistons 2 and a vertical guide shaft 3 are rigidly embedded in and extend downwardly from the carrier 1 into a compartment 1B defined by the foundation 1A beneath the carrier. The lower crosshead 5 which is disposed at the underside of the carrier 1 is received in the compartment 1B and is vertically reciprocably guided along the guide shaft 3 by two tubular guide bushings 6 which surround the guide shaft 3 and are slidable therealong. The bushings 6 are inserted into a central vertical bore 4 formed in the lower crosshead 5. The latter also carries two vertical press cylinders 7 each of which reciprocably receives one of the press pistons 2. In fact, the press pistons 2 constitute two additional guide shafts which also hold the lower crosshead against any other but vertically reciprocating movements.

As is best shown in FIGS. 2 and 3, the lower crosshead 5 is traversed by and is secured to the lower ends of four vertical uprights or columns 8, the upper ends of these uprights being secured to the upper crosshead 9. The portions of uprights 8-which'extend beyond the upper and lower sides of the crossheads 9, 5 are externally threaded and are Vsecured to the crossheads by tightening nuts Sa, Sb, respectively. The upper crosshead 9 carries `the upper table 9a which, in turn, supports the movable upper die 9b. The dimensioning of the guide shaft 3 and of press pistons 2 is such that they can safely take up all bending stresses which would normally act against the uprights 8. The uprights 8 are slidable through suitable vertical bores provided at the four corner portions of the stationary carrier 1; This carrier also mounts four retracting or lifting cylinders 12 each of which receives a retracting piston 11, the upper ends of the pistons 11 being connected with the upper crossheads 9 so that, once a hydraulic fluid is introduced into the retracting cylinders 12 (conduits 17) and the fluid is free to iow from the press cylinders 7 (conduits 15), the pistons 11 will retract the upper crosshead 9 with the movable die 9b into the position of FIGS. l and 2, i.e. away from the stationary die 1b. In the area of high temperatures arising during a forging operation, the uprights S are protected by tubular sleeves which are connected to and extend upwardly from the upper side of the carrier 1.

When a hydraulic pressure fluid is introduced into the press cylinders 7 (see FIG. 1), the lower crosshead 5 will travel in downward direction and, being connected with the upper crosshead 9 through the uprights 8, the cylinders 7 perform a working stroke in that they move the movable die 9b toward and into proper engagement with the stationary die 1b so that a workpiece placed between the two dies is subjected to a specific treatment. At the same time, the pressure fluid is free to ow from the retracting cylinders 12 so that the retracting pistons 11 do not prevent or impede downward movements of the upper crosshead 9. In the next step, fluid is introduced into the cylinders 12 and is discharged from the press cylinders 7 so that the upper crosshead 9 may perform an upward stroke to thereby move the movable upper die 9b away from the stationary lower die 1b. The press cylinders receive pressure uid through two conduits 15, through two channels 14 formed in the stationary carrier 1, and through two channels 13 formed in the press plstons 2, all of which are shown in FIG. 1. The conduits 15 communicate with a supply conduit 16 which leads to a control apparatus 19. The requisite fluid pressure is generated by a pump 31 which draws fluid from a source in the form of a reservoir 33, and the fluid then passes through a conduit 36 which communicates with the pressure side of the pump 31, through a check valve 27, and through another conduit 2S which leads into a gas-filled pressure tank 29. The tank 29 serves as a means .for storing the compressed fiuid which operates the forging press and is connected with the control apparatus 19 through a conduit 26 which communicates with one port of the check valve 27. The control apparatus 19 comprises

valves

20, 21, 22 and 23 whose respective stems 26a, 21a, 22a and 23a are connected to a camor crankshaft 24. The shaft 24 may be turned by a handgrip means or lever 25 which latter may be rocked into a series of positions indicated by the legends Forging pressure, Starting pressure, No load and Retractf When the

valves

26 and 22 are in open position, the press cylinders 7 are connected with the tank 29 through the

channels

13, 14, through the

conduits

15, 16, 26, 28 and through the check valve 27 (valve 22), and the cylinders 12 are simultaneously connected through conduits 17 and through a conduit 18 with the return conduit 32 which leads back to the reservoir 33 (valve 20).

When the upper crosshead 9 must perform an upward stroke to move the die 9b away from the die 1b, the lever 25 is shifted into the Retract position to thereby close the

valves

20, 22 and to simultaneously open the

valves

21 and 23. The valve 21 then permits the tlow of pressure huid from the conduit 26, into the conduit 18, and through the conduits 17 so that the retracting cylinders 12 receive uid and the pistons 11 move in upward direction. The open valve 23 permits return ow of pressure Huid from the press cylinders 7, through the channels, 13, 14, through the

conduits

15, 16, and through the return conduit 32 into the reservoir 33.

FIG. 3 shows that the axes of the guide shaft 3 and of the piston-

cylinder assemblies

2, 7 are disposed in the central symmetry plane of the forging press, and that the axes of pairwise arranged retracting piston-

cylinder assemblies

11, 12 and of the uprights 8 may be disposed in two vertical planes which are parallel with the central symmetry plane.

It will be noted that all bending stresses are taken up by the guide shaft 3 and by the press pistons 2 while the uprights 8 are subjected solely to such tensioning forces which act in directions parallel with the longitudinal axes of these uprights. Consequently, the uprights must be dimensioned only with a view to resist the tensioning forces but need not take up any bending stresses as in the prior apparatus of similar design.

Referring now to FIGS. 4a, 4b, 5 and 6, there is shown a modified hydraulic forging press of the underground type in which all component parts are identified by reference numerals followed by a prime. A single press cylinder 7' is located below the center of the stationary carrier or socket 1', and the latter supports a guide shaft 2 which simultaneously serves as a press piston. As is shown in FIG. 6, the arrangement of uprights 8 and of the retracting piston-cylinder assemblies 11', 12 is identical with the arrangement shown in FIGS. la, 1b, 2 and 3. The combined guide shaft and press piston 2' is formed with a smaller-diameter coaxial extension 35 which projects downwardly from and through a bushing 34 provided in the lower end Wall of the press cylinder 7. The latter s connected with the lower crosshead 5 and participates in vertically reciprocating movements of the upper crosshead 9.

The hydraulic supply and control lsystem of FIGS. 4a and 4b is practically identical with the system of FIGS. la and l'b, with the exception 'that the channels i3, lfl are replaced by a single channel 36 which extends through the wall of thecylinder 7 and that a single channel 15' is connected directly with the control apparatus 19'.

As is shown in FIG. v6, the combined guide shaft and press piston 2 is mounted inthe center of the stationary carrier 1.

'Without further analysis, the foregoing will so fully reveal ythe gist of 'the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a forging press, in combination, first and second crosshead means; stationary carrier means disposed ybetween said crosshead means; column means connecting said crosshead means for reciprocating movement in unison with respect -to said carrier means; means comprising at least -one guide shaft connected with said carrier means and slidably received in one of said crosshead means for guiding said crosshead means in parallelism with said column means and for relieving said column means from bending stresses when said press is subjected to eccentric forging pressure; and fluid operated lifting means laterally spaced fromand independent of said guide shaft and connected to said stationary carrier means and one of said crosshead means for lifting said crosshead means while the same are guided by said guide shaft.

2. In a forging press, in combination, stationary carrier means; first and second crosshead means disposed respectively above and below said carrier means; a plurality of vertical uprights slidably extending through said carrier means and connecting said crosshead means for reciprocating movement in unison with respect to said carrier means; means for guiding said crosshead means with respect to said carrier means and for relieving said uprightsfrom bending stresses when said press is subjected to eccentric forging pressure, said guiding means comprising at least one vertical shaft connected with said carrier means and slidably received in said second crosshead means; and a pair of hydraulic lifting means laterally spaced from and respectively at opposite sides of said guide shaft means and connected to said stationary carrier means and said first crosshead means for lifting said crosshead means while the same are guided by said guide shaft.

3. In a hydraulic forging press, in combination, stationary carrier means; rst and second crosshead means disposed respectively above and below said carrier means; a plurality of parallel vertical upright means extending through said carrier means and connected with each of said crosshead means whereby the crosshead means and the upright means are reciprocable in unison with respectv to said carrier means; at least one vertical guide shaft connected with and extending downwardly from said carrier means; and a cylinder connected with said second Y crosshead means and slidably receiving said guide shaft,

parallel with said columns, said shaft connected with said carrier means and slidably received in one of said crosshead means; at least one press piston parallel with said guide shaft and connected with said carrier means; and a cylinder connected to said one crosshead means and reciprocably receiving said piston, said piston and said cylinder constituting means for moving the crosshead means and said columns with respect to said carrier means.

5. In a hydraulic forging press, in combination, first and second crosshead means; stationary carrier means disposed between said crosshead means, said carrier means having a central plane of symmetry; a plurality of parallel columns extending through said carrier means and connected with each of said crosshead means whereby the crosshead means and said columns are reciprocable with respect to said carrier means; a central guide shaft parallel with said columns, said shaft connected with said carrier means and slidably received in one of said crosshead means, said shaft having anI axis located in said symmetry1 plane; a pair of press pistons disposed at the opposite sides of said shaft and each having an axis parallel with the axis of said shaft and located in said symmetry plane; and a pair of cylinders, one for each of said pistons, said cylinders connected to said one crosshead means and reciprocably receiving the respective piston, said pistons and said cylinders constituting means for moving said crosshead means and said columns with respect to said carrier means.

6. In a forging press, in combination, a pair of spaced crossheads; a stationary carrier disposed between Said crossheads; a plurality of parallel columns each slidably extending through said carrier and each connected to each of said crossheads whereby the crossheads and said columns are reciprocable with respect to said carrier, at least one guide shaft connected with said carrier and parallel with said columns; a cylinder connected to one of said crossheads and reciprocably receiving said guide shaft whereby said shaft and said cylinder constitute guide means for guiding said crossheads and said columns with respect to said carrier; an extension connected with said shaft and slidably projecting through said cylinder, whereby said guide shaft will take up bending stresses occurring when said press is subjected to eccentric forging pressure so as to relieve said columns from bending stresses; and a pair of hydraulic lifting means laterally spaced from and respectively at opposite sides of said guide shaft and connected to said stationary carrier and one of said crossheads for lifting said crossheads while the same are guided by said guide shaft.

In a forging press, in combination, a foundation deiinlng a compartment; a stationary horizontal carrier supported on said foundation and located above said compartment; a plurality of vertical uprights slidably extending through said carrier, each upright having an upper end and a lower end with said lower ends located in said compartment; an upper crosshead connected with the upper ends of said uprights; a lower crosshead received in said compartment and connected with the lower ends of said uprights whereby said crossheads and said uprights are reciprocable with respect to said carrier; at least one vertical shaft means rigidly secured to said carrier and slidably received in said lower crosshead for guiding the same during reciprocation and for relieving said uprights from bending stresses when said press is subjected to eccentric forging pressure; and a pair of hydraulic lifting means laterally spaced from and respectively at opposite sides of said vertical shaft means and connected to said stationary carrier and said upper crosshead for lifting said crosshead, said lifting means being independent of said guide shaft.

8. In a forging press, .in combination, a foundation deiining a compartment; a stationary horizontal carrier supported on said foundation and located above said compartment; a plurality of vertical uprights slidably extending through said carrier, each upright having an upper end and a lower end with said lower ends located in said compartment; an upper crosshead connected with the upper ends of said uprights; a lower crosshead received in said compartment and connected with the lower ends of said uprights whereby said crossheads and said uprights are reciprocable with respect to said carrier; at least one first piston-cylinder assembly operating between said carrier and said lower crosshead for moving the upper crosshead toward said carrier; at leastone second piston cylinder assembly operating between one of said crossheads and said carrier for retracting the upper crosshead in a direction away from said carrier; and at least one vertical shaft rigidly secured to said carrier and slidably received in said lower crosshead.

9. In a hydraulic forging press, in combination, a foundation defining a compartment; a stationary hori- Zontal carrier supported on said foundation and located above said compartment; a stationary die supported on said carrier; a plurality of vertical uprights slidably extending through said carrier, each upright having an upper end and a lower end with said lower ends located in said compartment; an upper crosshead connected with the upper ends of said uprights; a movable die connected with said upper crosshead; a lower crosshead received in said compartment and connected with the lower ends of said uprights whereby said crossheads and said uprights are reciprocable with respect to said carrier to move the movable die toward and away from said stationary die; at least one vertical shaft rigidly connected with said carrier and slidably received in the lower crosshead; at least one first piston-cylinder assembly operating between one of said crossheads and said carrier for moving the movable die toward said stationary die; and at least one second piston-cylinder assembly operating between one of said crossheads and said carrier for retracting the movable die in a direction away from said stationary die.

10. In a hydraulic forging press, in combination, a foundation defining a compartment; a stationary horizontal carrier supported on said foundation and located above said compartment; a stationary die supported on said carrier; a plurality of vertical uprights slidably eX- tending through said carrier, each upright having an upper end and a lower end with said lower ends located in said compartment; an upper crosshead connected with the upper ends of said uprights; a movable die connected with said upper crosshead; a lower crosshead received in said compartment and connected with the lower ends of said uprights whereby said crossheads and said uprights are reciprocable with respect to said carrier to move the movable die toward and away from said stationary die; at least one vertical shaft rigidly connected with said carrier and slidably received in the lower crosshead; at least one first piston-cylinder assembly operating between said carrier and said lower crosshead for moving the movable die toward said stationary die, said piston-cylinder assembly comprising a piston rigidly secured to said carrier Aand a cylinder mounted on said lower crosshead and slidably receiving said piston; and at least one second pistoncylinder assembly operating between said carrier and said upper crosshead for retracting the movable die in a direction away from said stationary die, said second assembly comprising a piston secured to the upper crosshead and .a cylinder connected with the carrier and slidably receiving said last mentioned piston.

11. In a forging press, in combination, first and second Icrosshead means; stationary carrier means disposed beitween said crosshead means; parallel column means connecting said crosshead means and extending through said carrier means whereby said crosshead means and said column means are reciprocable with respect to said carrier means; means operatively connected with said carrier means and with one of said crosshead means for guiding both said crosshead means and said column means with respect to said carrier means, said guiding means comprising at least one guide shaft connected with said carrier means and parallel with said column means, a cylinder secured to one of said crosshead means and slidably receiving said guide shaft, and a coaxial extension connected with said guide shaft and slidably projecting through said cylinder, whereby said guide shaft will take up bending stresses occurring when said press is subjected to eccentric forging pressure so as to relieve said columns from bending stresses; and fluid operated lifting means laterally spaced from and independent of said guide shaft and connected to said stationary carrier means and one of said crosshead means for lifting said crosshead means while the same are guided by said guide shaft.

12. In a forging press, in combination, a stationary carrier member; a crosshead above said carrier member; a crosshead member below said carrier member; a plurality of uprights connecting said crosshead and said crosshead member together for reciprocating movement in vertical direction with respect to said carrier member; guiding means comprising a vertical guide shaft fixed to one of said members and a pair of guide bushings fixed to the other of said members spaced 'in vertical direction from each other and receiving said guide shaft for guiding said crosshead member during the reciprocating and for relieving said uprights from bending stresses when said press is subjected to eccentric forging pressure; and uid operated means laterally spaced from and independent of said guide shaft and connected to said stationary carrier member and said crosshead for lifting said crosshead and said crosshead member operatively connected thereto.

References Cited in the file of this patent UNITED STATES PATENTS 336,604 Fielding Feb. 23, 1886 619,747 Holinger Feb. 21, 1899 2,212,047 Ross Aug. 20, 1940 FOREIGN PATENTS 330,973 Switzerland Aug. 15, 1958 1,030,288 Germany May 22, 1958 1,198,593 France Dec. 8, 1959

Claims

1. IN A FORGING PRESS, IN COMBINATION, FIRST AND SECOND CROSSHEAD MEANS; STATIONARY CARRIER MEANS CONNECTING TWEEN SAID CROSSHEAD MEANS; COLUMN MEANS CONNECTING SAID CROSSHEAD MEANS FOR RECIPROCATING MOVEMENT IN UNISON WITH RESPECT TO SAID CARRIER MEANS; MEANS COMPRISING AT LEAST ONE GUIDE SHAFT CONNECTED WITH SAID CARRIER MEANS AND SLIDABLY RECEIVED IN ONE OF SAID CROSSHEAD MEANS FOR GUIDING SAID CROSSHEAD MEANS IN PARALLELISM WITH SAID COLUMN MEANS AND FOR RELIEVING SAID COLUMN MEANS FROM BENDING STRESSES WHEN SAID PRESS IS SUBJECTED TO ECCENTRIC FORGING PRESSURE; AND FLUID OPERATED LIFTING MEANS LATERALLY SPACED FROM AND INDEPENDENT OF SAID GUIDE SHAFT AND CONNECTED TO SAID STATIONARY CARRIER MEANS AND ONE OF SAID CROSSHEAD MEANS FOR LIFTING SAID CROSSHEAD MEANS WHILE THE SAME ARE GUIDED BY SAID GUIDE SHAFT.