DE2809387A1 - HYDRAULIC CUTTING, BURRING OR THE LIKE. -PRESS WITH HIGHLY CHANGE MOVEMENT RESISTANCE OF THE PRESS SLIDE DURING THE SLIDE PATH - Google Patents

Description

Hydraulic cutting, trimming or the like press with the movement resistance of the ram, which varies greatly during the ram path Press ram

State of the art

The material processing carried out on presses requires in many cases the speed / ram path or the Speed / ram travel function that is neither realized with conventional mechanical or hydraulic ram drives can still be approximated with sufficient accuracy. The consequence of this are disadvantages of various kinds, such as. B. not optimal workpiece processing, too high stress on press and tool with corresponding wear, too strong noises, vibrations and the like.

Ba For example takes place when shearing steel or similar materials in the first phase of the cutting process a gradual increase in force, which a corresponding results in elastic deformation of the tool, press and drive elements. The subsequent break requires only a very small force, which is much smaller than that available Driving force and the force stored by the elastic deformation described. It therefore comes to one sudden relief of the pre-tensioned parts, caused by a bang - the so-called cutting impact - as well as the corresponding Vibrations with high loads are accompanied by press and tools. The adverse effects This cutting impact is attempted through complex additional systems in the power flow - so-called cutting impact absorbers - reduce.

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Another example of work processes that cannot be carried out satisfactorily with the known hydraulic press drives is what is known as isothermal forging, in which the flow behavior of the material during forging in a WW.se determined by the material properties is influenced by very sensitive control of the forging process should be- In this way z. B. machined titanium.

task

The invention is based on the object of a hydraulic Cutting, trimming or other press with one drive to create that makes it possible, the pressing force and / or the speed of the press ram very fast

- for example, within a few milliseconds - and to adapt precisely to the technological requirements.

solution

The object is achieved by the features reproduced in the patent claim.

Some advantages

In a press according to the invention, it is possible to use the To control or regulate the press drive in such a way that it is very sensitive and low in inertia - e.g. within a few milliseconds - electrically specified signals follows, which allow an exact adjustment of the force or Allow the speed profile to match the technological conditions »This means, for example, that bein Seher cutting the cutting impact without special cutting impact dampers reduce to a harmless level or

- if other influencing factors are favorable - even avoid them entirely. This is how a cutting press according to the invention works or the like. Environmentally friendly. There are hardly any ground vibrations,

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overall, longer tool life and less machine stress can be recorded. Even with very high loads on the press ram, there are no special foundations for the press ram in question Press required.

In other machining operations, the progression of the ram force and / or the ram speed can be optimized or improved so significantly over the known prior art that, depending on the other circumstances, higher quality workpieces can be achieved or other technological and economic advantages can be gained. A press designed according to the invention can also be used, for example, for isothermal forging or calibration because of its very sensitive and low-inertia control.

Further features and advantages emerge from the following description of the drawing in which the invention is illustrated schematically in one embodiment.

The reference numeral 1 denotes a press frame in which a vertical arrangement of its longitudinal axis Drive cylinder 2 is arranged. In the drive cylinder

2 is a drive piston longitudinally displaceable and sealing

3 guided, which is usually designed as a differential piston, but can also have the same piston areas.

The reference numeral 4 denotes a press ram with which in the illustrated embodiment, an upper tool is releasably connected, which is on a in the illustrated Embodiment plate-shaped workpiece 6 is able to act, which rests on a lower tool 7.

As the drawing reveals, the cutting press shown is assigned a hydraulic pump 8, which

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Sucks in a suitable hydraulic fluid from a tank 9 and transfers it via the pressure line 10 into a reservoir 11 or. promotes to a servo valve 12 “This servo valve can be opened, closed or switched over proportionally to a control current extremely briefly - for example, within about two milliseconds. In the illustrated fi • y:?. "ITJ v ~ i _i rS Servovenbils Λ2 is the pressure line 40 of the hydraulic JDrvi-ici'lasoigkeitjpu.iipe via a supply line 13 to the upper cylinder chamber 14 of the driving cylinder 2 HS-53 chi ο ο The right cylinder outlet 15 of the drive cylinder 2 is connected to the tank 9 via the drain line 16 and the servo valve 12, but in such a way that the drive piston 3 is to a certain extent due to the hydraulic fluid pressures prevailing in the cylinder chambers 14 and 15 is clamped because the control edges of the more or less open servo valve 12 act as throttles. In the position of the servo valve 12 shown in the drawing, the hydraulic fluid pressure acts on the larger piston area in the upper cylinder chamber 14, so that the pressure in the upper cylinder chamber 14 and the hydraulic differential pressure resulting in the lower cylinder chamber 15 drives the drive piston 3 and thus the upper tool 5 in the direction of the workpiece 6.

The reference number 17 is a suitable actual value sensor, which in the illustrated embodiment can be an electronic position measurement. Each by the actual value transducer 17 measured data are grounded to a transducer 18 passed on electrically, with a control amplifier 19 in a suitable manner electrically connected is.

A setpoint generator 20 also takes place on electrical bzxv. the setpoint specification electronically to the control amplifier 19, in which a target / actual comparison thus takes place.

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Both div; Pump · ;? 3 as well as eier iGtv / ert-.vai'nehnier 17, eier M ίί'Γ'Λ'ϊΓ ^ " ¹ : !!" · ¹ .Ti-H-IVJO " ^y \ ^r ~ -_ 1. ;;; . ·; Λ ■ . \ _V -j -> _:: [-Χ / - - .. - -] f _; ViCC! (Ii? "Γ setpoint fX'bcjr 20 can be rogel- or also be designed to be exchangeable, so that.

by one and the same drive system / changed setting

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The sovfie in dsr Besclireibun, which can be taken from the drawing t.md can be described in the patent claim features ncr-rohl single ols also in b ^ liohA ^ otL Ko: .i'uina fcioii-sn for the veruirlilichun ^ dar invention "- / oir- ^ r / clich be.

908883/0007 BAD ORDINAL

Claims (1)

Essen, _O 2 March 1978 PZ 3111 THYSSEN INDUSTRIE AG P.O. Box 69 80 ^ "00 Esnen 1 Claim Hydraulic cutting, trimming or the like - face with during the ram path strongly variable resistance to movement of the press ram, characterized in that that the cylinder space (14) for the working movement and the cylinder space (15) for the retraction movement of the press ram (4) at the same time via a fast-switching valve (12) without defined switching positions (servo valve 12) Pressure medium can be acted upon and the servo valve member is otherwise composed of at least one setpoint generator (20) Specification of a desired slide movement or force curve s, a ..in-dependent vooi press ram (4) actuated Actual value sensor (17) as well as a valve (12) control amplifier controlling according to the setpoint / actual value comparison (19) existing closed-loop control system. ORIGINAL! NSPECTED