DE3239899A1 - METHOD AND DEVICE FOR OBTAINING EXACT LENGTHS ON SECTIONS RESULTING FROM SHEARING OF STEEL ROD AND STICK MATERIALS FOR USE AS ROLLING FOR SOLID FORMING - Google Patents

Description

FROM KREISLER SCHÜNWALD EISHOLD FUES FROM KREISLER KELLER SELTING WERNER

PATENT LAWYERS Dr.-Ing. by Kreisler 11973

Dr.-Ing. K. Schönwald, Cologne

Dr.-Ing. K. W. Eishold, Bad Soden

Dr. J. F. Fues, Cologne

Dipl.-Chem. Alek von Kreisler, Cologne

Dipl.-Chem. Carola Keller, Cologne

Dipl.-Ing. G. Selting, Cologne

Dr. H-K. Werner, Cologne

October 27, 1982 Sch / Sd

DEICHMANNHAUS AT THE MAIN RAILWAY STATION

D -5000 KULN 1

Eumuco Aktiengesellschaft für Maschinenbau Josefstrasse 10, 5090 Leverkusen 1

Method and device for achieving precise lengths by shearing off steel rod and billet material resulting sections for use as a blank for the Forging

The invention relates to a method and an apparatus for obtaining precise lengths of by shearing Sections resulting from steel rod and billet material for use as a blank for massive forming.

Blanks for massive forming are mainly produced by shearing off steel rod or billet material, as this is a cutting process without material loss. aside from that the volume output is much greater than that of the other cutting processes such as sawing, burning, breaking and the like.

There are measuring methods known that make it possible to

Telephone: (0221) 131041 Telex: 8882307 dopa d Telegram: Dompatent Cologne

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To determine measurements of the billets before or after shearing / in order to then divide them into sections of equal volume. Sole marriage However, methods are only sensible if it is possible to achieve the section lengths determined in accordance with a nominal volume to be adhered to exactly.

For reasons of cost, the aim is to process billets as much as possible, i.e. material from the roughing mill. When using With conventional shear systems, however, volume fluctuations of up to about _ + 4% occur. Since such fluctuations in subsequent production steps to malfunctions, such as incorrectly shaped parts, excessive tool wear, tool and machine overload, etc., it is imperative to eliminate the volume fluctuations. the Volume scatter occurring during shear cutting on the cut blocks is therefore due to the large tolerance of the semi-finished product (billet) on the one hand and by influences of the machine and the tool on the other.

When setting the lengths of the sections to be sheared, it is known to use the stick or the like. by means of a RoIl- ganges through the scissors up to the stop on the outlet side of the same, with the feed caused by the driven rollers of the roller table. In order to be able to advance the stick, in general the roller plane of the roller table is raised so far that the stick is free of friction between the hold-down counter bearing or the bottom knife can run into the working area of the scissors. By making contact between the stop and the stick is then triggered the shear stroke. Before the cut, the hold-down device is actuated and the roll is turned is lowered in order to protect it from blows to the billet caused by the shearing process. Further if the stop is retracted during the cut,

to jamming of the sheared sections between the stop and knife to prevent. In doing so, it cannot be avoided / that there will be changes in position when the roller table is lowered of the stick or the like. can also come in the direction of the stick axis.

In addition, a discrepancy can result from the fact that the contact surface is in the raised position of the roller table of the stop to the stick lies anywhere in the non-flat fracture surface of the shear surface, whereby the position of the contact surface shifts when the roller table is lowered. Have the roughness of the fracture surface and the course of the fracture thus an influence on the section length. Furthermore, the contact pressure of the stick against the stop and thus its suspension, play, etc. from the variable dead weight of the stick and the coefficient of friction between the driven roller and stick or the like. addicted.

For crooked sticks and the like, and also for those that are getting shorter In relation to the stop, billet lengths also result in positional inaccuracies when lowering the roller table lead to section length inaccuracies. The feed force of the roller table changes when the billet is supported on the hold-down counter bearing. The support occurs when the sticks and the like are very crooked or less favorable Center of gravity of the stick ends getting shorter.

The roller spacing and the arrangement of the Roller table rollers in this context.

An interruption of the machine-side influencing variables has show that even with an optimally adapted tool and a constant billet cross-section with conventional shear systems the required constant volume of a maximum of + _ 0.5% in particular cannot be reached for shorter sections,

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In addition, the measuring methods for determining the required section length require their own tolerance field, see above that the tolerance from the machine influence must be well below the maximum permissible volume tolerance.

The invention is based on the knowledge that these fluctuations in volume in the overall system of the scissors, namely the feed of the material, hold-down device and stop will. The object of the invention is to provide a scissor structure with which the aforementioned volume fluctuations the required volume tolerance reliably reduced can be. As a prerequisite for the constant volume shear cutting, a maximum volume tolerance of 0.5% considered. The invention is characterized by a transport of the stick or the like. through the scissors under short-term Lifting from the shear level to a stop on the outlet side of the shears by means of a roller table, whereupon the stick or the like. is pressed against a counter bearing by means of a hold-down device and the shear stroke by contact closure is triggered between the stop and the stick, characterized in that after threading the stick or the like. in the working space of the scissors, the shear plane remains unchanged, the feed of the billet with constant feed force compulsorily until it stops, that the stick under a hold-down effect of a predetermined size the hold-down counter bearing is kept pressed during this feed process, and that then the fixation of the stick is made by a hold-down force of a larger size.

With the length adjustment of the sections according to the invention It is important that the shear plane is not changed except for the short threading process. Rather, the

Stick or the like. reliable when approaching the stop and forcibly held and guided so that the other sources of interference, e.g. changes in the position of the stick or Like. When lowering the roller table, the variable dead weight of the billet to be sheared, the coefficient of friction between the driven roller and the stick, will be switched off with certainty. The feed force is dimensioned in such a way that that the billet can be transported without any problems. The stick remains controlled when it approaches the stop and flawlessly managed. It is possible to eliminate the disadvantageous volume fluctuations at the sections and to press down to a volume tolerance well below _ + 0.5%. This is the prerequisite for accurate and seamless forging created, thereby making up for the parts to be forged result in significant advantages. One achieves much smaller dimensional fluctuations in the parts, what enables the production of ready-to-install functional surfaces without reworking. Furthermore, there is a weight saving when forging without a flash gap compared to the Forging with a burr. This results in a better grain flow, which results in a higher fatigue strength for the forged part results.

The stick or the like. should after the section length has been set so long by the feed device with constant feed force between feed device and Stop can be held clamped until the hold-down force of higher magnitude takes effect. The maximum possible feed path the feed device with constant feed force is kept larger than the maximum to be set Length of the section to be cut off. This results in the security that the leadership of the stick and the like is maintained to the stop until the fixation of the stick or the like. is made for the shearing process.

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The structure of the billet shears is designed according to a further feature of the invention so that the hold-down with at least two power levels are equipped, of which one power level takes over the guidance of the stick during positioning and the other power level the stick or the like. fixed during the shearing process. The further hold-down device is preferably of less force than that of the hold-down device used to fix the workpiece, wherein the further hold-down device with sliding frictional connection on the stick or the like. acts. The latter expediently takes place via at least one roller and the like. To avoid the friction forces counteracting the feed force To keep advancing the billet as low as possible.

The further hold-down device can advantageously be built into the hold-down device used for fixing be. Here it can be a piston-cylinder unit operated by a power means, e.g. hydraulically or pneumatically be, whereby a certain elasticity can be made possible in the pressing force. Another feature of the invention is a feed device with constant feed force, preferably from one that detects the stick Pliers that hold the stick or the like. can clamp with constant force and the feed rate after switching off the roller table takes over.

Because of the forced guidance of the stick when approaching the stop, the stop surface is always on the same Surface in the shear surface, this surface should be the flat cutting surface of the shear surface, since only on this Place the section length can be clearly set. About the surface pressure between the stop and the stick To keep it as small as possible, the shape of the stop surface must be adapted to that of the cut surface.

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Since guiding the stick or the like. by means of the feed device takes place with constant feed force and in this case an adjustment of the roller table in height is no longer provided is, the entire roller table on elastic buffers or the like. stored to him before caused by the shear strain Hitting the club to protect.

The invention is explained below with reference to an embodiment shown in the drawing.

The only figure shows a hydraulically driven billet shears with 'the device according to the invention for achieving precise section lengths, in side view, partially cut and in the scheme.

In the illustrated scissors 1 are between two uprights 2 a drive cylinder 3 and a lower knife holder 4, which carries the lower cutter 5, arranged, these parts forming a solid structural unit. The knife holder 4 also serves as a hold-down counter bearing. The drive cylinder 3 has a drive piston 6 with a upper knife holder 7 is equipped, which carries the upper knife 8. A further drive piston 6 a for the hold-down device 9 is arranged in the drive piston 6. On the lower one Knife holder 4 is arranged a counter-holder device 4a, which is designed as a cylinder in the lower part and cooperates with the stationary piston 4b.

On the outlet side of the scissors is a device 10 for Adjustment of the sections to be sheared off is provided by a stick 11, the adjustment preferably by means of a servomotor 12 can take place. On the length adjustment device 10 a stop 13 for the stick 11 is arranged. The contact surface 13a is capable of and Adapted the shape of the cut surface in the shear surface. For this purpose, the length adjusting device 10 can be adjusted in its height

can be adjusted and locked in position on the rail 10a.

At the inlet side of the scissors a feed device 14 is arranged, which has clamping jaws 15 and 16, which the Grasp stick 11 between you. The clamping jaws 15 and 16 are connected by a piston-cylinder unit 17 with a linkage 18 against the stick 11 in the cocked position brought. The clamping jaws 15, 16 here form a pair of pliers which clamp the stick 11 with constant force. The cylinder 19 is used to exercise a forward thrust for the pliers 15, 16. With 20 is a support for denotes the feed device 14.

On the inlet side of the feed device 14 is a roller table 21 with the rollers 22 is provided. On the driven rollers 22 of the roller table 21, the billet 11, the pointed edge is in the rollers 22 and the tong parts 15, 16, transported into the feed device 14. This is done the roller table 21 is raised so far by the lifting cylinder 23 that the billet 11 freely enter the press room can. The roller table 21 preferably rests on elastic buffers 24.

The hold-down device 9 is equipped with at least two power levels. The first force stage is used to fix the stick 11 during the shearing process and is activated by the piston 6a exercised. Another force level with a lower force effect is formed by a piston-cylinder unit 25, the piston 26 of which acts by means of a piston rod 27 on the stick 11, preferably by means of at least one roller 28, with a sliding frictional connection on the Stick 11 or the like. is available·. The further hold-down device 25, namely the piston-cylinder unit, can be driven by a power means, e.g. hydraulic or pneumatic,

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be operated. The second power level in the form of the hold-down device 25 takes over the leadership of the stick 11 or the like. when positioning at the stop 13a, the stick while advancing against the hold-down counter bearing 4 is held down.

The stick 11 or the like. becomes after the cut-off length has been set so

long through the feed device 14, 19

held clamped with a constant feed force between this and the stop 13 until the hold-down force larger size is effective by means of the hold-down device 9, wherein the stick is fixed. Then the feed loop will be used the clamping jaws 15 and 16 moved back into the starting position by the cylinder unit 19.

The roller table 21 is raised so far by the lifting cylinder 23 that the billet 11 freely enter the press room can. For the following shearing processes within the billet, the roller table 2.1 remains lowered without a drive Position, where it rests on the elastic buffers 24. The billet is only transported by the feed device 14 taken over.

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Claims (14)

Expectations 1J Method of achieving exact lengths by shearing sections resulting from steel rod and billet material for use as blanks for the massive forming, in which the beginning of the billet or the like. through the scissors while lifting briefly transported from the shear level to a stop on the outlet side of the shears by means of a roller table becomes, whereupon the stick or the like. is pressed against a counter bearing by means of a hold-down device and the shear stroke is triggered by the contact between the stop and the stick, characterized in that that after threading the stick or the like. the shear plane remains unchanged in the working area of the scissors, the feed of the billet with constant feed force is forced to the stop that the billet with a hold-down effect of a predetermined size on the hold-down counter bearing during this advance process is held down, and that then the fixation of the stick by a hold-down force higher Size is made. 2. The method according to claim 1, characterized in that the stick or the like. after the cut-off length has been set by the feed device for so long constant feed force is held clamped between the feed device and the stop until the hold-down force larger size takes effect. 3. The method according to claim 1 or 2, characterized in that the maximum possible feed path of the feed device with constant feed force is greater than the maximum length to be set for the section to be sheared off. 4. The method according to any one of claims 1 to 3, characterized in that that the hold-down effect is predetermined Size on the stick or the like. takes effect during the positioning of the same. 5. Device for achieving precise lengths of steel rod and billet material obtained by shearing off Sections for use as blanks for massive forming, in which the billet or the like. by means of a driven roller table through the work area of the scissors up to the stop on the outlet side of the same is transported, whereby the roller table is raised for threading and then lowered again, and at the shear stroke is triggered by the contact between the stop and the stick after the stick through the hold-down against the hold-down - counter bearing was fixed, characterized in that as a further Transport device a feed device (14) with constant feed force is provided on the shear plane, and that the hold-down device (9) with at least two Kraf.tstufen is equipped, of which the one power stage (25) the leadership of the stick (11) or the like. when positioning takes over the stop (13) and the other power level (6a) the stick or the like. during the shearing process fixed. 6. Apparatus according to claim 5, characterized in that in addition to the hold-down device (9) for fixing the billet (11) a further hold-down device (26, 27) with a lower force effect than that of the first hold-down device (9) is arranged, which under sliding frictional connection on the stick (11) or the like. acts. 7. Apparatus according to claim 5 or 6, characterized in that the power transmission of the further hold-down -W- device (26,27) on the stick (11) or the like. above at least one role (28) takes place. 8. Device according to one of claims 5 to 7, characterized characterized in that the further hold-down device (26,27) in the hold-down device used for fixing (9) is built in. 9. Device according to one of claims 5 to 8, characterized in that the further hold-down device (26,27) is a piston-cylinder unit actuated by a force means, e.g. hydraulically or pneumatically. 10. Device according to one of claims 5 to 9, characterized characterized in that the stroke of the feed device (14) with a constant feed force is greater than the maximum The length of the section to be cut is to be set. 11. Device according to one of claims 5 to 10, characterized characterized in that the feed device (14) with constant feed force is active until the other force level (6a) of the hold-down device (9) is effective. 12. Device according to one of claims 5 to 11, characterized characterized in that the feed device (14) with a constant feed force a stick (11) or the like. The gripping pliers (15, 16) clamp the stick (11) or the like with constant force and the feed after switching off the roller table (21) takes over. 13. Device according to one of claims 5 to 12, characterized characterized in that the stop surface (13a) of the stop (13) of the position and shape of the cut surface in is adapted to the shear surface. 14. Device according to one of claims 5 to 13, characterized characterized in that the roller table (21) is mounted on elastic buffers (24), e.g. rubber buffer bodies.