US3468152A

US3468152A - Hydraulic metal tube press

Info

Publication number: US3468152A
Application number: US547374A
Authority: US
Inventors: Hans-Henning Croseck; August Grohmann
Original assignee: Hydraulik GmbH
Current assignee: Hydraulik GmbH
Priority date: 1965-05-28
Filing date: 1966-05-03
Publication date: 1969-09-23
Anticipated expiration: 1986-09-23
Also published as: DE1452314A1; DE1452314B2; DE1452314C3

Description

Sept 23, 1969 HANs-HENNING cRosEcK ETAL 3,468,152

HYDRAULIC METAL TUBE PRESS Filed May 3, 1966 Illll.

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HAms-HENNING CRosEm AUGUST GROHMHNN 3T /W/uf M ffm/V United States Patent O im. c1. imc zszo; B215 9/18 U.S. Cl. 72-265 5 Claims ABSTRACT F THE DISCLOSURE A hydraulic metal tube extrusion press comprises a stationary press cylinder having a driving piston which is slidable therein. A mandrel is slidable in the driving piston and includes the usual stroke limiting stop means permitting it to be moved between two extreme positions. The mandrel includes a rear portion extending out through the driving piston and the press cylinder. In order to absorb the reaction force or back pressure which is formed in the press when the mandrel has pierced the workpiece in a pressing position the mandrel is braced to the main cylinder by a lock. In the embodiment shown, the lock comprises a power operated latch or coupling member which moves in vertical guides and engages around abutting flanges of the mandrel.

This invention relates, in general, to the construction of hydraulic presses and, in particular, to a new and useful metal tube press having an internal means for bracing the main mandrel.

The present invention particularly deals with a hydraulic extrusion press of the type having a main press piston which is slidable in a cylinder and which includes a press mandrel rod which is directed out through the rear end of the cylinder without requiring that the main piston have a rear extension or that there be a front distance piece between the press piston and the barrel spar or an extended portion of the barrel spar. A problem with presses of this nature has heretofore been one of absorbing the reaction forces. If this is not done, then the total pressing force for which the press is designed is not available for pressing out but is partially consumed.

Reaction forces become operative in the press, for example, when pressing out is done with a recessed or stopped mandrel. The reaction force is the force component of the pressing material enclosed between the press disk, container wall, and matrix which acts in particular on the mandrel shoulder and counter to the pressing direction of the movable part or the broaching device. This pressing force may be 40% and more of the total pressing force and must consequently be substracted from the total pressing force when determining the actual pressing force.

The problem underlying the invention, that is, of absorbing the reaction force is solved according to the invention by providing a moving part of the broaching device, in particular, the mandrel rod which is rigidly connected with the mandrel driving piston, with a bracing. The bracing in the desired position of the mandrel is preferably on the self-enclosed force absorbing system of the press which consists essentially of a main drive press bar, the counter spar and the traction elements connecting them. In accordance with the invention, the mandrel may be braced on any desired stationary part of the press or a base which is secured to the ground. By bracing the mandrel in this manner, it is possible to make use of the total pressing force for which the press is designed.

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According to another characteristic of the invention, the mandrel rod is connected with every movable part of the press which is able to absorb a reaction force by means of a power operated lock or coupling. For this purpose, the mandrel rod must be provided with an abutment or stop such as a coupling flange or a groove which can be connected either by two power operated latches or coupling claws with a stationary stop or coupling ange of the press. In a preferred arrangement, the latching mechanism includes coupling members which are movable crosswise to the axis of the mandrel rod and are positively guided preferably in the direction of movement and normal thereto.

Accordingly, it is an object of the invention to provide an improved hydraulic press which includes a mandrel rod which is extended through its associated cylinder and with means for bracing the rod at the portion thereof which extends through the cylinder for accomplishing a pressing operation.

A further object of the'invention is to provide a hydraulic press which includes a mandrel piston in which is slidable a mandrel rod which continues through the cylinder therefor rearwardly and is provided with a latching member which may be latched to a fixed end of the cylinder such as by a movable latching mechanism.

A further object of the invention is to provide a hydraulic press which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a longitudinal sectional View of an extrusion press constructed in accordance with the invention;

FIG. 2 is a view similar to FIG. l with the parts in different positions; and

FIG. 3 is an enlarged partial elevational and sectional view of a mandrel tip.

Referring to the drawings, in particular, the invention embodied therein includes a main driving cylinder 1 in which there is guided a main press piston or plunger 2. The front end of the piston 2 is provided with a barrel spar 3 which is secured thereto and guided on a bed 4. A ram 5 is disposed in the barrel spar 3 and it is indicated in position engaged in a pressing disk 6 of a pressing block 7 arranged within a container 8.

The rear portion of the pressing piston 2 is provided with an opening through which a driving piston portion 10 of the mandrel 11 is located. The piston 10 is axially slidable and rotatable within the associated cylinder 9. Between the mandrel 11 and the driving piston 10 there is provided a multipart connecting rod system 12.

ln accordance with the invention, the back of the mandrel 11 extends through the driving cylinder 9 and is provided with a rod portion 13 which extends outwardly through the rear of the cylinder 1. The outer end is provided with a thread 14 and a fastening nut 16 is threaded thereover against a movable stop 15. On the side of the stop 15 facing the press, there is provided a coupling flange 18. An extension 17 which is rigidly connected to the main press cylinder 1 includes a coupling flange 19 and it comprises part of the self-enclosed forces absorbing system of the press.

In the desired position of the mandrel 11 for the pressing out of the press piston 7, the stop 15 can be brought to apply with its iiange 18 against the ange 19 of the extension 17. By securing the nut 16, the stop 15 is held in a iixed position.

When pressing out, for example, by means of a -recessed mandrel 11, as shown in FIG. 3i, the mandrel tip 11 is arranged inside the press matrix 23. (This is the desired position). The transition from the mandrel tip 11 to the mandrel shank 11 is designated 11". The distance between the mandrel transition 11" and the end face of the matrix 23 is designated by the small letter p and the difference between the diameters 11 and 11 by the letter f. The reaction force is P =p f. This force acts in the direction of the arrow of FIG. 3.

In order to absorb the reaction force Pr, according to the inventive idea, the mandrel rod 13 is braced to the main cylinder 1 by a lock after the workpiece has been pierced so that the workpiece may be extended Without further advancing travel of the mandrel. To lock the mandrel rod 13 with the stationary main press cylinder 1, there is provided a power operated latch or coupling member 21 which slides in vertical guides 20 in the direction of the mandrel rod 13. The coupling member 21 includes claw projections 22 which engage around the abutting flanges 18 and 19 in such a manner that the mandrel rod is retained or is held fast and is therefore fully braced to the stationary cylinder 1.

While a specic embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it 4will be understood that the invention may be embodied otherwise Without departing from such principles.

What is claimed is:

1. A hydraulic metal tufbe extrusion press comprising a stationary press cylinder, a driving piston slidable in said press cylinder, said press cylinder and said piston deiining a fluid pressure chamber which is adapted to be pressurized to mave said drive piston relative to said press cylinder, a mandrel having stroke limiting stop means and being slidable in said driving piston between two extreme positions and having a rear portion extending out through said driving piston and said press cylinder, a second cylinder and piston means for actuating said mandrel, and bracing means on said press cylinder engageable with said mandrel in a pressing position after the workpiece has been pierced for anchoring said mandrel to said press cylinder to brace the rear portion of said mandrel.

2. A hydraulic metal tube press, according to claim 1, wherein said mandrel stroke limiting stop means is at the rear thereof, means for adjustably positioning said stop member 0n said mandrel, and a locking member movable to engage said stop member and to hold said stop member in a fixed position.

3. A hydraulic metal tube press, according to claim 2, including an extension formed on said press cylinder, said stop means adapted to abut against said extension, said bracing means locking said stop member with said mandrel in respect to said extension.

4. A hydraulic metal tube press comprising a stationary press cylinder, a driving piston slidable in said press cylinder, a mandrel slidable in said driving piston between two extreme postions and having a rear portion extending out through said driving piston and said press cylinder, means for bracing the rear portion of said mandrel in a pressing position, said mandrel including a stop memlber at the rear thereof, means for adjustably positioning said stop member on said mandrel, a locking member movable to engage said stop member and to hold said stop member in a fixed position, an extension formed on said press cylinder, said stop member adapted to abut against said extension, means for locking said stop member with said mandrel in respect to said extension, said stop member and said extension have abutting anges, said locking means including a member engageable around said anges to hold said stop member and said extension against relative movement.

5. A hydraulic metal tube press, according to claim 4, wherein said stop member is slidable on said mandrel, and a nut for locating said stop member which is threaded onto said mandrel.

References Cited UNITED STATES PATENTS 861,194 7/1907 schwieger 'l2-265 878,092 2/1908 Schwieger 72-265 3,190,102 6/1965 Mener 72-265 CHARLES W. LANHAM, Primary Examiner GENE P. CROSBY, Assistant Examiner U.S. C1. X.R. 72-453 l