EP2907629B1 - Cutting machine and method for influencing the deformation of the machine frame - Google Patents

Description

Cutting machine and method for influencing the deformation of such

The invention relates to a path-controlled cutting machine, such as a flat or high-speed cutting machine, for cutting sheet-like material to be cut into a stack, comprising a machine frame with a table with a table surface that receives the stack, a cutting device that extends from the machine frame and is adjustable to cut the stack into the machine frame , in particular comprising a knife carrier with a cutting knife, as well as at least one drive for adjusting the cutting device comprising a crank with a pulling or pushing element such as a push rod extending therefrom and connected to the cutting device. Furthermore, the invention relates to a method for influencing the deformation of a cutting machine when cutting a stack of sheet-shaped material to be cut, the cutting machine having a machine frame with a table receiving the stack and a cutting device that extends from the machine frame and can be adjusted to this, and a crank that can be adjusted to the machine frame having a pulling or pushing element and at least one linear guide.

The operating principle of corresponding cutting machines, which include cutting machines or high-speed cutting machines, such as these z. B. are offered by Perfecta Schneidmaschinenwerk GmbH Bautzen, Bautzen, Germany, under the name Perfecta Schnellschneider TS, whose generic construction is expressly referred to, taking into account the Fig. 2 can be described as follows. The material to be cut 10 arranged in the stack is positioned on a table 12 of a machine frame 14 to a cutting knife 16 and then fixed by means of a press beam. The cutting knife 16 is connected to a knife carrier 18, which in turn is connected to the machine frame via sliding guides. In this case, sliding blocks 20, 22 extending from the machine frame engage in corresponding guide grooves 24, 26 of the knife carrier 18. The guide grooves are aligned with the horizontal in such a way that the cutting knife runs parallel to the machine table at the end of the cutting process. Therefore, the angles of inclination α, β of the guide grooves 24, 26 to the horizontal are different when there is only a unidirectional drive for adjusting the knife carrier 18, as in principle the Fig. 2 can be found. In the machine frame, a crank 28 is rotatably mounted about a pivot point 27, which is connected to the knife carrier 18 via a pull rod 30. If the crank 28 is set in rotation, the knife carrier 18 and thus the cutting knife 16, which are collectively referred to as the cutting device, are drawn through the material to be cut at a speed V. The cut is completed when the crank 28 is at bottom dead center BDC. The crank 28 executes one full revolution per cut, so that after the cut the crank 28 reaches the top dead center OT. In this position, the knife 16 is raised and the cutting space, the so-called cutting cell, is freely accessible, so that the material to be cut only has to be positioned or removed from the machine. The corresponding constructions are path-controlled systems.

So that the cutting knife 16 is not damaged by the table surface 12 after the stack 10 has been cut, a so-called cutting bar 32 is inserted into the table 14. This is in particular a plastic strip into which the cutting knife 16 can penetrate. This also ensures that the bottom sheet of the material to be cut is cut correctly.

To cut the material to be cut, a force is required which is basically a surface load (compressive force) which acts along the cutting line 34 in the cut surface. Due to the sharp cutting edge in relation to the width of the knife, we can also speak of a line load in simplified terms. This line load can also be integrated for illustration purposes. The integral force is in Fig. 2 symbolized as a point load, which acts _{in the direction of the arrow F M.}

Since forces do not occur individually, but always in pairs of forces, not only does the force F _{M act} on the cutting knife, but an equally large force Fs also acts on the material to be cut. These forces can be drawn across all elements of the cutting machine. The result is a closed force flow 36, which closes via the pull rod 30, the knife carrier 18, the cutting edge 16, the material to be cut 10 (stack), the table 12 and thus the machine frame 14 and ultimately via the crank 28.

According to Hooke's law, the occurrence of forces leads to deformations with Δ1 = F / k, where k is the spring constant of the component to be considered. When designing cutting machines, great importance is attached to high rigidity, i.e. a high value for the spring constant k. From a technical and economic point of view, however, there is no possibility that k tends towards ∞. In other words, a deformation of individual components will always occur in cutting machines, which ultimately add up to an overall deformation.

A great unknown in the system is the stiffness of the material to be cut. Is z. If, for example, a very hard material to be cut and / or a very wide stack is cut, this results in a high level of spring stiffness in the abstract model view. When a deformation occurs by means of a z. B. designed as a crank drive, this leads to a large force between knife and stack. This force must be absorbed by all components of the cutting machine that are in the force flow. This can result in a relatively large overall deformation Δ1 of the machine, which is usually in the range of 1/10 mm. This deformation is problematic if that Cutter has reached the bottom sheet of the stack. In the worst case, the deformation is so great that cutting through is no longer possible.

These disadvantages are known per se. Therefore, compensating elements are used to compensate for corresponding deformations, with which the machine deformation is compensated so that the effective distance 1 is kept at a level that allows the last sheet of the stack to be cut. This compensation takes place through the intervention of the operator, so that there is the disadvantage that a stack first has to be cut incorrectly in order to be able to intervene in a regulating manner.

Solutions with regard to the compensation elements are z. B. eccentric on the suspension of the crank in the machine frame, eccentric on the suspension of the sliding blocks or a length compensation in the tie rod, which can also have the task of compensating for the wear of the cutting knife and the cutting bar.

However, this compensation does not help if stacks of different hardnesses and / or widths are to be cut one after the other, since the cutting machine does not transmit any feedback to the operator about deformations. A prediction is also difficult, since the overall spring stiffness of the system depends not only on the machine parameters, but also, as mentioned, on the stack width, paper quality, paper surface, sharpness of the cutting knife, its grinding angle, etc., to name just a few parameters. Thus, there is the disadvantage that, for. B. after the operator has set the balancer on a hard pile - d. That is, the effective distance 1 is shortened by means of the compensation device - the position of the compensation device is left in this state. If a soft stack with low spring stiffness is cut, the deformation of the machine is small and the effective distance is too short. As a result, the cutting knife hits the cutting stick with full force, so that it can be irreparably damaged. The result is high repair costs and machine downtimes.

It has been considered to use soft cutting sticks. However, this solution is not effective because the cutting bar is in the power flow and thus contributes to the higher overall deformation in hard cutting positions and consequently causes problems.

With a cross cutting machine according to the DE 11 515 A Falling knives are used for cutting, which are caught by rubber sleeves when falling.

From the DE 834 404 B a cutting device is known which comprises a movable knife which can be adjusted against a stationary knife by means of rigid or resilient members for cutting a material to be cut.

A hand-operated sheet cutter according to the DE 10 2012 100 506 A1 has a cutting blade which can be lowered via a lever mechanism having a handle. When lowering the cutting blade of the force-controlled cutting device, a force generated by hook retaining springs must be overcome, by means of which a cutting blade retaining mechanism is lowered in the direction of the paper sheet or sheets to be cut.

With a force-controlled scrap shears after the DE 195 29 134 A1 a device for damping the cutting impact is provided.

A device for cutting in particular pieces of meat and similar substances according to the DE 44 00 413 A1 provides shock absorbers to enable the energy to be absorbed before the cut is complete.

the DE 1 618 149 U relates to veneer shears in which a cutter bar is lowered by means of a hydraulic or pneumatic drive, the piston being moved back into the starting position by means of a compression spring. A pair of scissors has a cutter bar with an upper cutter, which is adjusted to a lower cutter by means of a pressure cylinder. There are also compression springs by means of which the upper knife is moved back after the pressure cylinders are depressurized. Both the pressure cylinder and the cutter bar are supported in such a way that a superimposed downward and longitudinal movement occurs during the cut. Subject of DE 834 404 C is a cutting device for paper. The device has a movable knife, which by means of rigid or flexible formed members is adjustable for cutting the material to be cut against a fixed knife.

A scrap shear is out of the DE 195 29 134 Al known, in which the cutting blow is dampened.

Of the GB 2 057 088 A a shock absorber for noise reduction in machines with reciprocating machine parts can be found.

The present invention is based on the object of developing a path-controlled cutting machine and a method for influencing the deformation of a cutting machine of the type mentioned in such a way that a safe Cutting through the material to be cut including the last sheet running arc is ensured. Manual intervention and, to a large extent, the setting of compensating elements should be avoided. It should be possible to cut stacks of different hardness or material to be cut with different quality parameters or stacks of different widths one after the other without any problems, without the need for readjustment in principle. A deformation of the machine frame should be basically prevented when cutting.

The invention is defined in claims 1 and 9.

To achieve the object, a cutting machine of the type mentioned is essentially developed in such a way that at least one counter-element is provided in operative connection between the machine frame and the cutting device, which generates a force opposing the cutting movement of the cutting device, the force generated by the at least one counter-element is such that, regardless of the stiffness of the stack when cutting the stack, any deformation of the machine frame that occurs is the same or essentially the same, and the at least one counter-element is in operative connection at a distance d from the table surface with d ≤ h + x with h = Height of the stack and x ≥ 0 mm.

In one embodiment, it is provided that the counter-element or counter-elements connecting the machine frame, in particular its table with the cutting device _{, has or have an overall rigidity k G} that usually has the greatest rigidity compared to the rigidity ks of the and with the Machine to be cut stack is large, in particular x • k _G = ks with x <1, in particular 0.4 <x <1, preferably 0.4 <x <0.6.

The at least one counter-element can be a spring, in particular a spring with a progressive characteristic curve, such as a gas pressure spring, so that the counterforce is only generated shortly before cutting or during cutting.

There is also the possibility that the at least one counter element is a damper or a viscoelastic element.

According to the invention, it is proposed that the at least one counter-element comes into operative connection at a distance d from the table surface with 0 mm <d h with h = height of the stack, in particular 0 <d 5 mm, preferably 3 mm d 5 mm.

The method of the type mentioned at the outset is characterized in that an operative connection is established between the machine frame and the cutting device, at least before the end of the cutting process, by means of which a force is generated which is directed against the cutting movement. In particular, it is provided that the counterforce is generated by at least one counter-element connecting the cutting device to the machine frame, in particular its table, due to the deformation of the machine frame occurring independently of the stiffness of the stack when cutting the stack, and that the at least one counter element at a distance d from the table surface is in operative connection with d h + x with h = height of the stack and x 0 mm.

A related method, whereby a closed force flow between the machine frame, the drive, the cutting device and the stack is formed when the stack is cut, is characterized in that the force flow between the cutting device and the table is divided by the at least one counter-element.

Regardless of this, the counterforce should preferably only be generated after the start of the cutting process and, of course, before it is completed.

Separated from the above, it should be noted that the counterforce F is preferably F> 800 N.

In the cutting machines according to the state of the art like the DE 10 2012 100 506 A1 or DE 195 29 134 A1 are force-controlled cutting machines. It will a force is exerted on a cutting element (e.g. knife) by a mechanism. This then moves through the material to be cut until a counterforce is reached that corresponds to the force introduced and thus brings the knife to a standstill. It may be that the counterforce is already being applied by the material to be cut and so that the material to be cut is not completely cut through or only by a mechanical stop at the end of the cutting process. In principle, with force-controlled systems, the knife can come to a standstill at any position if a corresponding counterforce is reached. This results in the need for a damper element. If there is no product to be cut under the knife, i.e. if no counterforce is generated, the knife is theoretically constantly accelerated. Technically, dampers are used to brake the very strongly accelerated knife at the end of the path in order to avoid collisions, for example.

The teachings of the present invention relate to a routed system. The difference here is that the knife - firmly connected to a drive and gearbox - is forced to follow a defined path with a defined speed and acceleration. Since in this case the path and the speed are fixed by the gear (crank), damping elements are ineffective. Since practically any counterforce exerted by the material to be cut or other elements (e.g. dampers) that are exerted on the knife does not lead to negative acceleration, but rather to a higher drive force due to the rigid connections with the drive, which compensates for the counterforce. Technically, such a system has the advantage that the force automatically adapts to the material to be cut and, in the absence of a counterforce, there is no acceleration or, if the counterforce is too high, the knife (cutting device) is braked. Rather, the knife moves with a constant speed profile through the material to be cut. The disadvantage is that with very hard material to be cut, the forces can be very high, theoretically even infinitely. However, this force inevitably leads to a proportional expansion of the frame and the entire drive train. In extreme cases, this expansion can become so great that the imprinted path is no longer sufficient to cleanly cut through the entire material to be cut. According to the invention it is therefore proposed that the at least one counter-element generates a force which is always greater than the force which is exerted by the material to be cut on the knife and thus on the machine frame. As a result, the machine frame can be dimensioned so that the natural expansion, which cannot be prevented structurally, is always so large, that at the bottom dead center of the movement of the knife edge or an element with the same effect, the gap between knife edge and machine frame is equal to or approximately equal to 0 mm. This guarantees an average.

In the path-controlled system of a cutting machine, the path control is essentially implemented by a crank with a pull or push rod and at least one linear guide. Other embodiments, such as. B. lever drives, linear drives with position control, rack and pinion drives, spindle drives, belt drives, position-controlled servohydraulic systems are also possible.

The solution according to the invention provides that the original power flow F between the cutting device and table is divided into at least two power flows F _A , F _B. This is achieved in that a device called a counter element is integrated between the cutting device and the machine frame or the table, which exerts an additional force in the opposite direction to the force causing the knife movement. This generates a second force flow F _A running parallel to the original force flow, the division according to the invention being designed such that the second force flow F _A made possible by the at least one counter-element is greater than the parallel first force flow Fa.

For the operation of the cutting machine, this means that even with very low spring stiffnesses caused by the material to be cut or its stack, a load is always applied that leads to machine deformation. If this force dominates, i.e. the force flow F _A via the at least one counter-element is considerably greater than the force flow F _{B directly penetrating the material to be cut, then the deformation caused by the force flow F B} penetrating the material to be cut is of subordinate importance, so that the machine deformation Δ1 as constant view and an operator intervention can be omitted. Possible existing compensation devices can be set to a fixed value. This ensures that the cutting knife is not damaged, a constant one Readjustment is not necessary. The last sheet of the stack is also safely cut.

A large number of construction principles are conceivable for the technical implementation of the distribution of the power flow in the cutting machine.

The counter-element can be designed as a spring with a stiffness k _F , where k _{F is selected to be} greater than k _s , that is to say the stiffness of the material to be cut or the stack for which the greatest force would be required.

stellt sich die größte Steifigkeit als die für das System dominierende Steifigkeit heraus.According to the equation for connecting springs in parallel $$1/{\mathrm{k}}_{\mathrm{total}}=1/{\mathrm{k}}_{\mathrm{F.}}+1/{\mathrm{k}}_{\mathrm{s}}$$

the greatest stiffness turns out to be the dominant stiffness for the system.

mit d = Dämpfungskonstante.It is also possible to design the counter element as a damper. This results in the force occurring parallel to the cutting force from the speed V of the knife moving in the direction of the material to be cut in accordance with the equation $$\mathrm{F.}=\mathrm{d}•\mathrm{V},$$

with d = damping constant.

This has the advantage that the force does not act continuously on the machine, but only when the speed is not equal to zero, i.e. in cutting mode.

However, there is also the possibility of a combination of elastic element and damper, i.e. viscous element. So-called viscoelastic behavior is often shown by rubber materials. These combine the advantages of both elements, i.e. the elastic and viscous elements, and can be manufactured inexpensively.

In a further development, it is provided that the counter element with its elastic, viscous or viscoelastic, that is to say force-applying elements, is not continuously integrated in the force flow, but only temporarily.

It is particularly advantageous if the counter-element is arranged in such a way that the power flow is not divided until shortly before the bottom dead center position when a crank is used as the drive. As a result, the cutting machine can be operated in an energetically favorable mode. Because of the short path over which the counter-element generates the counterforce, little work is required. Technically, this can be achieved in that the contact, that is to say the operative connection, takes place shortly before the cutting knife hits the stack or even just before the stack is completely severed.

The teaching of the invention also has the advantage that any games such. B. be compensated between Zugstande and their pick-up points or between the scenes and the knife carrier guides.

Further details, advantages and features of the invention emerge not only from the claims, the features to be taken from them - individually and / or in combination - but also from the following description of preferred exemplary embodiments that can be taken from the drawing.

Fig. 1

eine Prinzipskizze einer Schneidanlage,

Fig. 2

eine Prinzipskizze mit wesentlichen Elementen einer Schneidmaschine,

Fig. 3

ein mechanisches Ersatzmodell der Darstellung gemäß Fig. 2,

Fig. 4

das mechanische Ersatzmodell nach Fig. 3 mit Merkmalen des Standes der Technik,

Fig.5

ein mechanisches Ersatzmodell mit Merkmalen der erfindungsgemäßen Lehre und

Fig. 6-8

mechanische Ersatzmodelle mit Merkmalen der erfindungsgemäßen Lehre.

Show it:

Fig. 1

a schematic diagram of a cutting system,

Fig. 2

a schematic diagram with essential elements of a cutting machine,

Fig. 3

a mechanical equivalent model according to the illustration Fig. 2 ,

Fig. 4

the mechanical replacement model Fig. 3 with features of the state of the art,

Fig. 5

a mechanical equivalent model with features of the teaching according to the invention and

Fig. 6-8

mechanical replacement models with features of the teaching according to the invention.

Of the Fig. 1 a schematic diagram of a cutting system 100 can be seen, which has a cutting machine 102 with a front table 104 and a rear table 106 as its core. The front table 104 is a section of the table 12 connected to the frame 14 of the cutting machine or is the table 12 itself. The same applies to the rear table 106 align this with the cutting knife 16 of the cutting device of the cutting machine 102. For this purpose, a saddle 108, which can be adjusted along the rear table 106, and a sideshift 110, 112 are provided. Furthermore, a slide 110 extends from the front table 104, by means of which the illustrated stack or another stack to be cut can likewise be aligned with the cutting device. Furthermore, an air table 116 and a moving table 118 are shown in order to indicate further elements of the cutting system 100. By means of a corresponding cutting system 100, goods to be cut, such as sheets of paper, aligned to form stacks are cut to the desired extent. A detailed structure of a corresponding cutting system is z. B. the DE 10 2012 101 193 A1 to be taken to which reference is made.

In order to cut the stack, it is aligned with the cutting edge 16 and fixed by means of a clamping device such as a press beam. As has been explained above, the knife carrier 18 with the cutting edge 16 is then pulled through the stack 10 at the speed V by means of a drive - in the exemplary embodiment by means of the crank 28. The cut is then completed when the crank 28 with the pull rod 30 has reached bottom dead center UT. The crank performs one full cut per cut Turn off. In the upper dead center OT the cutting space is freely accessible in order to reposition the material to be cut 10 or to remove it from the cutting system.

The cutting takes place with a path-controlled system and not force-controlled.

Based on Fig. 2 the cutting process, the occurring forces and the force flow are explained, whereby the occurrence of the forces F causes deformations that are dependent on the rigidity of the components of the cutting machine as well as on the properties of the material to be cut and the size of the stack.

One of the Fig. 2 the corresponding mechanical replacement model is the Fig. 3 with summarized stiffnesses and concentrated parameters. All additional stiffnesses, such as B. summarized the bearings in the illustrated spring stiffnesses.

Due to the occurrence of the forces, deformations always occur according to Hooke's law Δ1 = F / k with k = spring constant. Even if there is an effort to produce cutting machines with high rigidity and thus with a large value of the spring constant k, there are limits so that a deformation of individual components that add up to an overall deformation must always be expected.

In order to compensate for the deformation, compensating elements are used on the operator side, which essentially have the task of compensating for the machine deformation and thus keeping the effective distance 1 at a level that ensures the severing of the last sheet of the material to be cut.

Corresponding compensation elements 40 ( Fig. 4 ), which are installed or adjusted by an operator 42, can be eccentrics on the crank suspension or sliding guide suspensions or length compensation elements in the pull rod 30. The compensation element must be in the power flow and be able to handle the Compensate for the change in length Δ1 due to the deformations in order to keep the effective distance 1 constant. Corresponding compensation elements can consequently also be attached to the table or machine frame.

According to the representations in the Figures 4 to 8 To avoid uncontrollable or non-reproducible deformations, the force flow between the cutting device, in particular the knife carrier 18 and the frame 14 or its table 12, is divided into at least two force flows F _A and F _B. For this purpose, a device 44, to be designated as a counter element, is provided between the cutting device or the knife carrier 18 and the frame 14 or its table 12, via which an additional force is generated in the opposite direction of the force caused by the movement of the cutting knife 16. At least two force flows means that the device 44 can have not just one counter-element, but several counter-elements, so that the force flow F _A1 , F _A2 ... F _An running over the device 44 is divided according to the number n of counter-elements.

As a result of these measures, a second force flow F _{A running parallel to the original force flow F B is} generated. It is designed in such a way that the condition F _A > F _{B is} met, in particular x • F _A = F _B with x <1, in particular 0.4 <x <1, preferably 0.4 <x <0, 6th

For the operation of the cutting machine, this means that, even with very low spring stiffnesses K, the _{material to be cut of} the material to be cut 10 or its stack is always subject to a load which leads to machine deformation. If this force F _{A dominates} , that is, if the condition F _A > F _{B is} met, the additional force F _B applied by the cutting system is only of subordinate importance. This means that the machine deformation Δ1 = constant and there is no need for an operator to intervene, or compensating devices are not required or can be set to a fixed value.

These measures prevent damage to the cutting knife 16, and the operator is relieved of constant readjustments.

Technical implementations of the counterforce generating device are the Figures 6 to 8 refer to. These embodiments are given purely by way of example and can be replaced by other equivalently acting devices or counter-elements, a combination of different counter-elements to build up the counter-force is also possible. In particular, there is the possibility of dividing the force flow via the counter-element or elements into several strands.

According to the Fig. 6 For example, a spring or several springs 46 with a total stiffness k _{additional device} (k _F ) which is greater than the stiffness k _{material to be cut} (k _s ) of the material to be cut can be used as a counter element.

stellt sich die größte Steifigkeit als die für das System dominierende Steifigkeit heraus. k ist in den Figuren k_{Zusatzeinrichtung} und ks ist k_Schneidgut.According to the equation for connecting springs in parallel $$1/{\mathrm{k}}_{\mathrm{total}}=1/{\mathrm{k}}_{\mathrm{F.}}+1/{\mathrm{k}}_{\mathrm{s}}$$

the greatest stiffness turns out to be the dominant stiffness for the system. In the figures, k is an _{additional device} and ks is k to be _cut .

mit d = Dämpfungskonstante.There is also the possibility of designing the counter element as a damper 48. This results in the force occurring parallel to the cutting force from the speed V of the knife 16 moving in the direction of the material to be cut 10 in accordance with the equation $$\mathrm{F.}=\mathrm{d}•\mathrm{V},$$

with d = damping constant.

This has the advantage that the force does not act continuously on the machine, but only when the speed is not equal to zero, i.e. in cutting mode.

However, there is also the possibility of a combination of elastic element and damper, i.e. viscous element. So-called viscoelastic behavior is often shown by rubber materials. These combine the advantages of both elements, i.e. the elastic and viscous elements, and can be manufactured inexpensively.

In a further development, it is provided that the counter element with its elastic, viscous or viscoelastic, that is to say force-applying elements, is not continuously integrated in the force flow, but only temporarily.

It is particularly advantageous if the counter-element is arranged in such a way that the power flow is not divided until shortly before the bottom dead center position when a crank is used as the drive. As a result, the cutting machine can be operated in an energetically favorable mode. Because of the short path over which the counter-element generates the counterforce, little work is required. Technically, this can be achieved in that the contact, that is to say the operative connection, takes place shortly before the cutting knife hits the stack or even just before the stack is completely severed.

This should be done using the Fig. 8 be clarified. It can be seen that the counter-element 50, shown purely in principle, is almost divided into two parts, the sub-elements 52, 54 only then interacting, i.e. the required counterforce is generated which is directed against the force of the knife movement when the cutting knife 16 is shortly in front of the item 10 to be cut is located or the material to be cut 10 has already been severed to a certain extent without, however, having completely severed the relevant stack.

With these measures, the machine can be operated in an energetically favorable mode. Little work is thus required to compress the additional device, since the path on which the counterforce is generated is relatively short and the work W is the product of force and path.

The teaching according to the invention also has the advantage that the incision depth of the cutting knife in the cutting bar can be set to a minimum value, which also results in a reduction in wear.

Claims (12)

1. Cutting machine (102), such as a guillotine or high-speed cutting machine, for cutting sheet-like cutting material forming a stack (10), comprising a machine frame (14) having a table (12) with table surface (32) receiving the stack, a cutting device (16, 18) extending from the machine frame and adjustable thereto for cutting of the stack, and at least one drive (28, 30) for adjusting the cutting device comprising at least one crank (28) with tension or compression element (30) extending therefrom and connected to the cutting device,
   wherein
   at least one counter-element (44, 46, 48, 50) is provided in operative connection between the machine frame (14) and the cutting device (16, 18), which generates a force in the opposite direction to the cutting movement of the cutting device, the force generated by the at least one counter-element (44, 46, 48, 50) being such that the deformation occurring of the machine frame (14) is identical or substantially identical regardless of the stiffness of the stack (10) during cutting of the stack, and the at least one counter-element entering an operative connection at a distance d from the table surface where d ≤ h + x with h = height of the stack and x ≥ 0 mm.
2. Cutting machine according to claim 1,
   wherein
   the counter-element(s) (44, 46, 48, 50) connecting the machine frame (14), in particular its table, (12) to the cutting device (16, 18) has/have overall a stiffness k_G which is high in comparison with the stiffness ks of the stack, in particular × • k_G = ks where x < 1, in particular 0.4 < x < 1, preferably 0.4 < x < 0.6.
3. Cutting machine according to at least one of the preceding claims,
   wherein
   the at least one counter-element is a spring (46), in particular a spring with a progressive characteristic such as a gas pressure spring.
4. Cutting machine according to at least one of the preceding claims,
   wherein
   the distance d is 0 < d ≤ 5 mm, preferably 3 mm ≤ α ≤ 5 mm.
5. Cutting machine according to at least one of the preceding claims,
   wherein
   x = 0.
6. Cutting machine according to at least one of the preceding claims,
   wherein
   the at least one counter-element is a damper (48) or a viscoelastic element.
7. Cutting machine according to claim 1,
   wherein
   the cutting device comprises a blade carrier (18) with cutting blade (16).
8. Cutting machine according to claim 1,
   wherein
   the tension or compression element is a rod (30).
9. Method for influencing the deformation of a path-controlled cutting machine (102) during cutting of a stack (10) of sheet-like cutting material, the cutting machine having a machine frame (14) with table (12) receiving the stack and a cutting device extending from the machine frame and adjustable thereto and a crank (28) adjusting the cutting device (16, 18) relative to the machine frame with tension or compression element (30) and at least one linear guide,
   wherein
   at least prior to completion of the cutting operation an operative connection is made between the machine frame (14) and the cutting device (16, 18) by which a force in the opposite direction to the cutting movement is generated, due to which the deformation occurring of the machine frame is identical or substantially identical regardless of the stiffness of the stack (10) during cutting of the stack, the counter-force is generated by at least one counter-element (44, 46, 48, 50) connecting the cutting device to the machine frame, and the at least one counter-element enters an operative connection at a distance d from the table surface where d ≤ h + x with h = height of the stack and x ≥ 0 mm.
10. Method according to claim 9, where during cutting of the stack (10) a self-contained force flow forms between the machine frame (14), the drive (28, 30), the cutting device (16, 18) and the stack,
    wherein
    the force flow is split by the at least one counter-element (44, 46, 48, 50) between the cutting device (16, 18) and the table (12), one force flow passing through the at least one counter-element and the other force flow through the stack (10).
11. Method according to claim 9 and/or 10,
    wherein
    at least one element from the group of spring, spring with progressive characteristic, damper, viscoelastic element is used as the at least one counter-element (44, 46, 48, 50).
12. Method according to at least one of claims 9 to 11,
    wherein
    the counter-force is generated exclusively after the beginning of the cutting operation.

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