DE1092425B - Device for limiting the punch stroke of hydraulic metal extrusion presses with an axially displaceable sensor - Google Patents

Description

GERMAN

When stopping metal extrusion or pipe extrusion after completion of the extrusion process is ensure that the remainder of the block remaining in the transducer is of the desired size. The remainder of the block shouldn't be too big to avoid unnecessary waste. However, the block is not supposed to save one either Too small a residue are pressed out, because this increases the pressing pressure extremely sharply, which causes damage of the punch and the die.

In order to always get a constant pressing residue, it is known to pass through the main inlet valve to close a circuit arrangement by means of a limit switch, which is from an adjustable stop is operated. Shutting down metal presses with limit switch arrangements is for medium-sized Suitable pressing speeds.

The invention is based on the object of providing a device for limiting the stamp stroke for To create presses with axially displaceable transducers that are also suitable for the highest press speeds is applicable and ensures a constant block remainder regardless of inertial forces. Such Devices are already known in the form that, for. B. between piston crosshead and block pick-up a horseshoe-shaped pressure piece retracted transversely or one mounted on the stamp carrier Claw ring compared to a claw ring of the same type arranged on the transducer face is rotated. In this case, when the piston crosshead or punch carrier hits the Pressure piece or the claws on the counter claws the piston pressure from the block pick-up to the press counter beam transfer. Such a limitation leads to time losses in the subsequent ejection of the Block remnants from the transducer. Because additional work steps are required, namely loosening the stroke limit surfaces from each other and the extension of the pressure piece or turning the claw ring before ejecting the remainder of the block required advance of the ram or retraction of the transducer is possible.

Another embodiment of a known rigid stroke limitation is that the main plunger has an extension rod reaching through the cylinder base on which the desired stroke can be adjusted by means of an adjusting nut. The main press piston must therefore be im Diameter are kept correspondingly larger; also builds the press as a result of the extension piece longer. The conditions become more unfavorable, the greater the compressive forces exerted by the adjusting nut must take up.

In the case of pipe presses, it has already been suggested

contraption

to limit the punch stroke

of hydraulic metal extrusion presses with axially displaceable transducers

Applicant:

Hydraulics GmbH,
Duisburg, Mülheimer Str. 72

Hermann Prött, Duisburg,
has been named as the inventor

to arrange adjustable stops to limit the stroke of the press mandrel in its operating position, which are supported on the opposite spar. This is what is known as the Pressing over the mandrel tip allows. The press mandrel only reaches into the die opening with its tip, because it is suitable for pressing due to its small diameter, which corresponds to the inside diameter of the pipe would be too weak with a moving mandrel.

According to the invention, the pressure pieces serving to limit the punch stroke are directly supported on the opposite spar. The measure according to the invention is compared to the known support of the Stroke limiting parts achieved a considerable gain in time when ejecting the block residue from the sensor. It is not necessary to retract the ram a little first to remove the pressure piece extend or rotate the claw ring. The ejection of the block residue can be done with the known Devices only take place when the stroke limitation has been rendered ineffective in this way is. The elimination of these auxiliary measures in the device according to the invention thus also brings one substantial simplification of the tax operations with itself.

Furthermore, the invention avoids the disadvantage inherent in the known stroke limits, that in the necessary for the removal or uncoupling of the pressure piece retraction of the The press ram pulls the block residue adhering to this a piece away from the die into its position in which it is difficult to shear off.

Opposite to the stroke limiter by means of an adjusting nut on a protruding through the cylinder base

009 647/185

led extension rod is the necessary enlargement of the plunger diameter in addition to an additional seal on the cylinder base, and the overall length and weight are saved.

The pressure pieces according to the invention can either be on the counter bar or on the piston crosshead be attached and reach through holes or openings made in the transducer holder. According to a particular embodiment of the invention, they can also be installed in bores or recesses the transducer holder be held longitudinally displaceable. To ensure that with this arrangement the Pressure pieces that always maintain their position within the transducer holder, the pressure pieces are advantageous resettable in a central position by spring cushions effective in both axial directions.

When pressing different materials or with different profiles, you often want different to get large remnants of blocks. According to a further training feature of the invention are to for this purpose interchangeable between the pressure pieces and the piston crosshead or the press counter beam Spacers are provided which vary depending on the size of the block remainder desired are long. When the pressure pieces are attached to the press counter beam or stored in the pick-up holder it is advisable to attach the interchangeable spacers to the piston crosshead. On the other hand If the pressure pieces are attached to the piston cross-head, the spacers on the press counter beam will be used attach.

The invention is illustrated in the drawing using exemplary embodiments and in more detail below explained. It shows

Fig. 1 is a section through part of the extruder with retracted ram and retracted Block,

FIG. 2 shows a section according to FIG. 1 with the block pressed out except for the remainder of the block,

3 shows a section according to FIG. 2 with the remainder of the block ejected from the receiver.

In the main press cylinder 1, the press piston 2 with punch holder 3 and press ram 4 is movably received, and the ram 4 is guided through the piston cross-head 5 in the press. In Fig. 1 is the Block 6 shown before it is pushed into the bore 7 of the transducer. The transducer 8 is in Mounted pickup holder 9, which is longitudinally displaceable in the guide 10. The press counter beam 11 is equipped with the die holder 12 and die 13.

From the upper half of Fig. 1 it can be seen that the pressure piece 14 to absorb the stroke limiting forces is attached to the press counter beam 11 and extends through the bore 15 of the transducer holder. In the lower half of Fig. 1, another embodiment is shown in which the Pressure piece 14 is mounted in the transducer holder 9 so as to be longitudinally movable. In this embodiment, that is Pressure piece 14 provided with a collar 16, which is supported in both directions on coil springs 17, their abutments are formed by the screw connections 18 at both ends of the transducer holder 9 will.

Opposite the pressure pieces, the spacers 19 are exchangeable on the piston crosshead attached. These spacers allow an accurate

ίο Setting the desired size of the block remainder.

As can be seen from FIG. 2, the press comes to a standstill when it reaches the end position defined by the pressure pieces 14 and the spacers 19, the remainder of the block reaching exactly the preselected size. Here there is a distance H 1 between the punch holder 3 and the block pick-up 8, which allows the pick-up to be withdrawn a sufficiently large piece H 2 so that the remainder of the block can be ejected from the pick-up immediately after the press has come to a standstill.

After the residue is ejected from the receiver, as shown in Fig. 3, is between the There is no longer a gap between the press die holder and the block pick-up.

Claims (5)

Patent claims: 1. Device for limiting the punch stroke of hydraulic metal extrusion presses with axially displaceable transducer, which essentially consists of between the piston crosshead and a fixed abutment consists of pressure pieces arranged on the side of the press counter beam, characterized in that the pressure pieces (14) are supported directly on the counter bar. 2. Apparatus according to claim 1, characterized in that the pressure pieces (14) either are attached to the counter bar (11) or to the piston crosshead (5) and through bores (15) or Reach through the openings in the transducer holder (9). 3. Apparatus according to claim 1, characterized in that the pressure pieces (14) in bores of the transducer holder (9) are held longitudinally displaceable. 4. Apparatus according to claim 3, characterized in that the held in the transducer holder (9) Pressure pieces (14) by spring pads (17) acting in both axial directions into one Central position are resettable. 5. Apparatus according to claim 1 to 4, characterized by exchangeable spacers (19), on the piston crosshead (5) or on the press counter beam (11) opposite the pressure pieces (14) are appropriate. ' Considered publications:
German Patent Nos. 271 428, 636 743;
French patents nos. 378 722, 453 173. 1 sheet of drawings © 009 647/185 11.60