A tube or metal extrusion press has a stationary press frame formed by a main housing, a counter housing, a billet support carrying a billet holder, and a ram cross-member movable in the press frame between the housings. A piston-cylinder unit has a cylinder on the main housing, a piston in the cylinder, and a ram stem extending between a front end of the piston and the ram cross-member. An equalizing reservoir supplies hydraulic fluid to the piston, and a transfer passage extends between the reservoir and the cylinder rearward of the piston. A fill valve has a displacement sleeve on a rod and carries a ring piston and a fill valve body movable centrally of the cylinder in the transfer passage between an open position in which the passage has a large annular flow cross-section and a closed position in which the valve body blocks the passage.

Each time a highly-viscous substance is extruded, a variation in weight of each cut piece of the highly-viscous substance is minimized. Metallic sodium (5) loaded in an extruder main body (3) is extruded from a nozzle (7) of the extruder main body (3) with a pressing tool (4) and, when it is detected that the metallic sodium (5) is extruded to a predetermined position, the movement of the pressing tool (4) is stopped and the extruded metallic sodium (5) is cut. In this case, an impulse (P) after stop is brought closer to a constant value until a load no longer acts on the metallic sodium (5) in the extruder main body (3) after stopping the movement of the pressing tool (4) by adjusting the movement speed of the pressing tool (4).

A hybrid extrusion press is provided with electric motors and hydraulic assist cylinders to cause a container holder to slide, wherein connecting rods are fastened to a container holder, the hydraulic assist cylinders have piston rods and gate devices connecting or disconnecting the connecting rods and the piston rods, and the gate devices are provided with hollow members fastened to the piston rods, enlarged diameter parts provided at single ends of the connecting rods and moving back and forth inside hollow parts of the hollow members, and locking parts provided at the hollow members and locking the enlarged diameter parts.

A double action extrusion press has: a main crosshead provided freely movable with the application of pressure in an axial direction by a main cylinder and having a pressing system disposed on the tip thereof; and a piercer cylinder built into the main cylinder and provided within the main ram, allowing a mandrel to slide within the pressing system and the main crosshead. The double action extrusion press complements the extrusion force by force equivalent to a mandrel pull force acting on a mandrel stop rod by affixing the piercer cylinder in contact to a piercer crosshead that is joined with the mandrel stop rod and applying hydraulic force to the rod side of the piercer cylinder.

A method is used to manufacture a drawn tube having a hollow low interior for housing an axle shaft. The method includes the steps of placing a billet into a first die assembly and pressing the billet into the first die to producing a pre-formed billet. The method also includes the steps of moving the pre-formed billet from the first die assembly to a second die assembly and pressing the pre-formed billet into the second die assembly to produce an extruded tube. The method further includes the steps of moving the extruded tube from the second die assembly to a third die assembly and pressing the extruded tube into the third die assembly to further elongate the extruded tube and decrease the thickness of the wall of the extruded tube to of from about 3 to about 18 millimeters to produce the drawn tube having the yield strength of at least 750 MPa.

An extrusion press machine includes an end platen, a die, a container, container cylinders which move the container back and forth, a stem that pushes a billet in the container, and a main cylinder at the front end of the stem is provided and by which the stem can freely slide front and back, the extrusion press machine further including a plurality of hydraulic valves that supply hydraulic oil in the main cylinder to the container cylinders and which operate before the stem and the container retract in movement when discharging compressed air in the container after upset of the billet and further including a hydraulic valve that discharges hydraulic oil in the main cylinder into a tank, the hydraulic valves connected by a hydraulic pipeline, and the main cylinder and the container cylinders being able to be connected.

A mold for forging a scroll rotor capable of controlling material flow speed by adjusting a land section, a molding device applying same, and a method for manufacturing the mold. In the mold, a die includes an extrusion unit having a molding space therein and a spiral-shaped extrusion passage provided in the lower portion thereof so as to correspond to a wrap portion disposed in the scroll rotor. A punch is connected to the die to be in close contact with the inner circumference of the molding space and to be able to slide up and down. The lower portion has a shape corresponding to the upper surface of the flange portion of the scroll rotor and a boss portion. The extrusion passage has a land section in direct contact with the extrusion material. The height of a land of the land section varies along the spiral direction.

The invention relates to extrusion and pipe presses (1), comprising a press frame consisting of a cylindrical spar (2) and a counter spar (4) connected thereto, in which a mobile billet container holder (7) supporting a billet container (8), which puts a billet (18) to be pressed, which was introduced by a loading device, into a press position in front of the counter spar (4) with the associated tool (38), and a mobile punch crosshead (6) are provided. In the cylindrical spar (2), a main cylinder, or press cylinder, is arranged, which in the cylinder housing (9) thereof receives a press piston (11), which at the front end thereof that is supported by the punch crosshead (6) is connected to a press punch (19). A compensation tank (15), which delivers hydraulic oil to the press piston (11) by way of a slider plate (28), is assigned to a main cylinder housing (9) connected to a tank line. With an extrusion press such as this, the considerable hydraulic expenditure, and in particular the non-productive time, are to be substantially reduced, while making the structural design more compact and simple at the same time. To accomplish this, the advancing and feed motions of the billet container holder (7) and punch crosshead (6) with press piston (11) are carried out by electromotive force, and both the precompression of the billet (18) loaded into the billet container (8) and the subsequent compression of the billet (18) are done by hydraulic loading of the press piston (11). Electric motors (12, 13) are assigned to the punch crosshead (6) and the billet container holder (7) as adjustment drives. A large-scale filling valve (20) is integrated in the cylinder housing (9) of the main cylinder for loading the press piston (11).

A rotational extrusion molding die and a slender metal workpiece made with same are introduced. The rotational extrusion molding die includes a female mold device, a male mold device, and a rotation driving device. The female mold device is symmetric about an axis to define a cavity corresponding in shape to the slender metal workpiece. The male mold device is movable controllably along the axis relative to the female mold device, allowing the metal blank to pass through the cavity and thereby turn into the slender metal workpiece. The rotation driving device drives the female mold device to rotate about the axis relative to the male mold device. The slender metal workpiece thus manufactured has continuous metal flow lines which extend continually along the axis and along an arc defined by the axis, thereby improving the slender metal workpiece in mechanical properties, mechanical strength, and damping capacity.

The present invention provides an extrusion press which eliminates unevenness of dynamic and thermal fatigue degrees of the hydraulic devices which form the hydraulic circuit in the extrusion press, the electric motors which drive the hydraulic pump, the control devices, etc., which makes the dynamic and thermal fatigue degrees and remaining service lives of the component devices even, and which is excellent in energy saving effect. An extrusion press which has a plurality of variable capacity type hydraulic pumps connected to it in parallel for supplying working oil to hydraulic cylinders of the extrusion press, uses a preset working speed as the basis to find the required discharge rate of the hydraulic pumps, and selectively controls the drive operations of the hydraulic pumps, wherein the order of selection of the hydraulic pumps which are selectively controlled in drive operation is controlled by a program which progressively advances when a predetermined number of molding cycles are completed.