High speed cutter for rolled web

ES 2 201 385 T3

DESCRIPTION

High speed scissors for cross cutting laminated strip.

The invention relates to high-speed scissors for transversely cutting rolled web with a blade arranged on at least one of two opposing drums, especially chisel blade with blade cutting edge, which can be accelerated at the forward speed of the rolled strip to be cut and the drums can be adjusted to each other for the realization of a cut, where the drums can be accelerated, through at least one drive device associated with them, at a circumferential speed corresponding to the speed of the rolled strip to be cut and at least one of the drums is associated with an adjusting device that can be driven separately.

During hot broadband manufacturing there is an increasing tendency towards endless lamination. The material of use is generated through the union by welding of prebands or in foundry machines. But the hot broadband is created in the course of a semi-endless rolling process, in which the material to be used can have multiple lengths of the pre-bands, which can be temporarily stored in roller paths, roller hearth furnaces or in coil boxes.

The finished strip should be cut after the rolling process to strip lengths that correspond to the required coil weights. Cutting must be done in continuous operation, that is, at rolling speed. Therefore, it should be boosted at the currently usual speeds of hot broadband trains in the range of 5 m / s to 30 m / s, preferably 10 m / s to 20 m / s. The strip thicknesses are in this case between 0.5 mm and 30 mm, preferably between 0.6 mm and 1.5 mm.

Known drum or crank shears, which serve for hot wide web cutting, are not designed for such high web speeds. But also the scissors, which are used after the cold rolling tandem trains, currently work only up to web speeds of about 6 m / s; Here too there is a requirement for a considerably higher speed.

Known cutting procedures, in which the knife drums must be accelerated for cutting at web speeds of up to 30 m / s and then must be slowed down again, can no longer be carried out with tolerable expense at speeds as high as 30 m / s. the band.

As an aid, it has already been proposed that the acceleration of the knife drums at belt speed or the operation of the knife drums at belt speed can be controlled separately from the movement perpendicular to the belt, and that for this purpose at least one of the drums is associated with an adjusting device that can be actuated separately.

In this case, one of the drums may be associated with a blade and the other drum may be associated with an anvil that cooperates with the blade or an enveloping region that acts as an anvil.

However, in this configuration of the scissors, a safe and exact separating cut of the strip is only guaranteed when the cutting gap between the cutting edge of the blade and the anvil or the surrounding region of the opposite drum is zero. On the other hand, - for example, in the case of excessive blade length - the blade and anvil can be overloaded to destruction, and in the case of short blade length, the separation cut is incomplete.

However, the adjustment of the cutting gap with "null" cannot or cannot be achieved with the necessary security by virtue of one or more of the influencing variables that collaborate such as thermal expansion, wear, elastic behavior of the adjustment device, forces acceleration, manufacturing tolerances, etc. Therefore, it is necessary to let the blade protrude out of the cutting circle in order to truly reliably separate the web.

However, this projection causes a rapid increase in cutting forces and, therefore, wear phenomena in all components of the cutting elements, from the cutting device to the drum housings.

Document G 92 04 602.9 (U1) proposes, the same as the patent publication US-A 23 41 503 mentioned there to remedy these difficulties and drawbacks a configuration of the scissors with a chisel blade of the knife drum in such a way that it is mounted projected outside the cutting circle with respect to an enveloping region of the drum that acts as an anvil and in such a way that it can be elastically abutted against at least one spring element with predetermined restoring force, where the housing and the fixing of an elastically arranged blade are configured parallel to the axis of rotation of a knife-holder cylinder with a groove placed on its periphery and machined therein and with pressure points arranged distributed over the length of each blade.

A disadvantage of this type of construction is the considerable technical expense of manufacture during the assembly of the elastic components in the inner space of the knife drum. This leads in the event of a breakdown or in the event of a necessary overhaul to considerable downtime of the knife station with production failure, which heavily burdens the operating costs and the performance of the entire plant.

Documents EP-A-0 576 005 as well as EP-A 0 016 615 relate to shredding scissors of another type and to a cutting head, respectively, for cigarette paper and for filter cigarettes.

The present invention, starting from the state of the art mentioned above, has the task of developing high-speed scissors of the type of construction mentioned in the preamble of claim 1 to cut hot strip and cold strip avoiding difficulties and limitations. techniques, so that accurate cuts are safely achieved at web speeds of up to 30 m / s even with minimum web thicknesses, and in particular especially without overloading the blades, the anvil or the surrounding region of the opposite drum as well as the adjusting mechanism and the drum support housings and / or the incomplete execution of the cut.

For the solution of the task, it is proposed in a high-speed scissors of the type characterized in the preamble of claim 1 of the invention that

ES 2 201 385 T3 the chisel blade is mounted on the blade drum projecting from the cutting circle with respect to the anvil or to the surrounding region of the drum acting as an anvil and bearing elastically against at least one spring element with presettable restoring force; the chisel blade is inelastically embedded in the knife drum and the adjusting device, which receives the knife drum with its housing, is mounted so that it can be supported elastically against the spring element with a predetermined restoring force, that the adjusting device is configured with rocker arms that can be actuated by adjusting cams, where the knife drum is mounted so that it can be supported elastically with its rocker, which receives the housing, of the adjusting device against a damper with a predetermined restoring force.

With the solution according to the invention the advantageous result is achieved, in fact, the blade that protrudes first from the cutting circle can elastically yield in the cutting process by impacting on the anvil or on the surrounding region of the second drum that acts as anvil to the point that an unacceptable increase in shear forces is safely avoided and therefore wear phenomena on all components of the cutting elements or the adjusting device up to the drum bearings.

One configuration of the invention provides that one of the knife-holder drums is equipped with a chisel blade and the other drum is equipped with the anvil that cooperates with the chisel blade. But an alternative measure can also be used, in the sense that one of the drums is equipped with a chisel blade, which cooperates with a surrounding region of the second drum that acts as an anvil.

In general, the invention achieves that the chisel blade impacts on the band during the rotation of the drum, separates it and then rests on the anvil or on the surrounding region of the opposite drum that acts as an anvil and deflects or yield elastically below.

During the collaboration between the blade and chisel and the anvil drum the advantage is achieved that the synchronization of the circumferential speeds of the two drums does not have to be spatially exact. On the contrary: in the case of a difference in the circumferential speeds between the chisel blade and the anvil drum, the entire circumference of the anvil drum can be used in cooperation with the blade, thereby achieving a wear distribution and the availability of the scissors is favorably improved.

Therefore, the principle described above is especially well suited for severe operation in hot rolling mills for maximum web speeds.

Other configurations of the invention are provided according to the dependent claims.

Other details, characteristics and advantages of the invention appear from the following explanation of an exemplary embodiment represented schematically in the drawing. Figure 1 shows the object of the invention in the form of an adjusting device for chisel blades and anvil drum with elastic support of an adjusting beam in side view.

The figure shows high-speed flying scissors with a knife-holder drum 6 and an anvil drum 7 cooperating with it for the division of a laminated strip 4. The two drums 6, 7 can be accelerated with a drive device not shown below. the speed of advance of the laminated strip 4 to be cut and can be adjusted relative to each other for carrying out a cut with an adjusting device 36. By means of an adjustment device of this type, the two drums 6, 7 are carried, independently of the adjustment process, in order to carry out a cut at a circumferential speed, which corresponds to the advance speed of the band 4 to cut, and during the remaining operating time they are kept at this circumferential speed, while the setting for cutting immediately after the cut is made is returned to a neutral open position, to allow a predetermined section length of the band to pass uncut through the scissors.

According to the invention, it is provided that the chisel blade 2 of the knife-holder drum 6 is mounted projected outside the cutting circle 40 with respect to an anvil 24 or with respect to the surrounding region of the drum 7 which acts as an anvil of so that it can be rested elastically against an adjusting device 36 with a predetermined restoring force. In this case, the chisel blade 2 is non-elastically embedded in the blade drum 6.

In this way, the chisel blade is then elastically supported in its protruding cutting position with a predetermined restoring force. In this way, the chisel blade 2 can be moved back against the spring force elastically in the direction of the center of the drum during the cutting process after separating the laminated strip 4 to the extent that damage is avoided. of the cutting edge 3 of the blade or of the surrounding region of the anvil drum 7. Otherwise, the anvil drum 7 can be made of relatively soft material, in order to care for the chisel blade 1.

In figure 1 an adjustment device 36 is shown with rocker arms 25, 26 that can be activated by means of adjustment cams 22, 23. This comprises an embodiment according to the invention, in which the chisel blade 2 is non-elastically embedded in the knife-holder drum 6, and the knife-holder drum 6 is housed with its adjusting device 36 which receives the housing so that it can be supported elastically against a shock absorber 29 with a predetermined restoring force.

In this embodiment, the blade 2 can spring from the cutting circle 40 against the anvil 4 when a predetermined peak load is reached, the rocker 25 then rising by a corresponding amount against the force of the spring 30, to avoid a overload of the blade 2, the anvil 24 and all other components, including the housing of the drums 6 and 7.

Figure 1 shows a preferred embodiment of the invention, represented purely schematically. In this case, the knife-holder drum 6 has an inelastically embedded chisel blade 2 which, in collaboration with the anvil 24 of the anvil drum 7, cuts the laminated strip 4

ES 2 201 385 T3 through the cutting section, in the case of a corresponding adjustment of the adjusting device 36. Since the adjusting cams 22, 23 of the adjusting device 36 describe an invariable eccentric travel, to achieve a cutting gap of size zero would require a protrusion Ü of the chisel blade 2 with respect to the anvil 24. This would undoubtedly lead to a spontaneous increase in the action of the force between the cutting edge 3 of the blade and the anvil 24 and, therefore, of the entire adjusting device 36 including the eccentric housings, of the drums and the joints 27, 28 on the rocker arms 25, 26. In order to avoid here, according to the teachings of the invention, the overload of all the components through the bearing of the chisel blade against a spring element with improved restoring force, for example the rocker arm 25 is supported with its articulation 28 elastically against helical spring 30 shown by way of example. In this case, the damper 29 receives a linear guide on the guide element 31, and the damper 29 can be limited in its downward movement through the adjusting screw.

The invention optimally improves high-speed scissors resulting in clean cutting sections without overloading the scissors components, especially at conveying speeds of the laminated web to be cut of up to 30 m / s.

List of reference signs

Elastically Mounted Chisel Blade

1 'Chisel Blade Segment

Fixed recessed chisel blade

Blade cutting edge

Laminated band

Knife drum

Anvil drum

Closing element

Radial guide

Tab

Shank, shank blade

Steel spring packages

12 'Spring Disc Packs

12 ”segment-type elastic elements

Piston

Cylinder

Pressure plate

Pressure stem

Screw joint

Pressure accumulator

Closing armature

Screw

Gas pressure spring

Eccentric adjustment

Eccentric adjustment

Anvil

Rocker

Rocker

Joint

Elastically supported joint

Shock absorber

Spring element, coil spring

Guide element

Set screw

Displacement mechanism

Travel path

Hydraulic fluid column

Adjusting device

Free rolling

Free rolling

Cutting circle