EP3248743A1 - Cutting machine - Google Patents

Abstract

The invention relates to a cutting machine (1) for cutting cutting material (15), with a working means (2) which can be acted on the material to be cut (15), wherein a lifting and / or lowering movement of the working means (2) by means of a hydraulically operated power means (4) is effected. This cutting machine has a hydraulic system (16), the power means (4), a pump (18) for conveying hydraulic fluid, a tank (19) for hydraulic fluid and between the power means (4) and the pump (18) and between the Power means (4) and the tank (19) has two successively arranged valves (20, 21) for controlling the flow of hydraulic fluid, wherein the functionality of the working fluid (2) is given only when driven identical functional position of both valves (20, 21). In such a cutting machine, the effort to ensure safe operation of the cutting machine can be largely reduced.

Description

The invention relates to a cutting machine for cutting material to be cut, with an actionable on the material to be cut working means, wherein a lifting and / or lowering movement of the working means is effected by means of a hydraulically operated power means.

Such cutting machines are well known in the art. There, the working means are in particular a cutting blade or a pressing beam of the cutting machine. The press beam serves to press the material to be cut before the cut. The press beam is mounted vertically movable in a machine frame and is lowered onto the stored on a table of the cutting machine Schneidgutstapel. If the material to be cut is fixed by the pressing beam, the cutting blade is lowered, in particular in an oscillating cut, and cuts through the material to be cut. The cutting knife is also stored in the machine frame.

The working means - cutting blade or pressing bar - are thus to perform their function to raise and lower. Here, both the lifting and lowering by means of the working fluid associated hydraulically operated power means can be carried out. It is sufficient to carry out only the lowering movement by means of the hydraulically operated power means, however, the lifting movement by external force means, such as springs. This applies in particular to the operation of the press bar.

With regard to the printed prior art, for example, the EP 0 584 601 A1 . DE 28 24 660 A1 and DE 28 48 108 A1 directed.

The cut material to be cut is, in particular, stacks formed from individual sheets. For example, the individual sheets of paper or foil.

In cutting machines of the type mentioned considerable safety requirements are to be met, since dangers, especially danger of crushing, emanating from the beam and with respect to the cutting blade there is a risk that limbs of the operator are separated. Consequently, according to safety regulations, it is required that it must be possible to detect within one cycle that a safety circuit has failed.

Safety circuits must be constructed in such a way that a diverse redundancy is guaranteed. As a result, safety circuits or safety channels must be constructed differently. This requires a considerable effort with regard to the safety-related components, in particular with regard to safety electronics.

Object of the present invention is to develop a cutting machine of the type mentioned so that the effort to ensure safe operation of the cutting machine can be significantly reduced.

The object is achieved by a cutting machine which is designed according to the features of patent claim 1.

The invention proposes a cutting machine for cutting material to be cut, with an actionable on the material to be cut before working means, wherein a lifting and / or lowering movement of the working means is effected by means of a hydraulically operated power means. In this cutting machine, a hydraulic system is provided, which includes the power means, a pump for conveying hydraulic fluid, a tank for hydraulic fluid and between the power means and the pump and between the power means and the tank two valves arranged one behind the other for controlling having the flow of hydraulic fluid, wherein the functionality of the working fluid is given only when controlled identical functional position of both valves.

In principle, the functions of the cutting machine, which relate to the working medium which can be acted upon on the material to be cut, could also be achieved only by the one of the valves. This one valve is suitable in the different switching positions to switch the hydraulic system in the required functional position of the working fluid. This basically sufficient one valve is supplemented by the identical in its functionality second valve, the two valves are arranged one behind the other. This means that the functionality of the working fluid is only guaranteed if both valves are actuated in their identical functional position. If the two valves - in faulty - in different functional position, is blocked by the malfunctioning valve control of the working fluid via the hydraulic system, so that the working fluid does not work.

Thus, the malfunction is detected by the failing function of the working fluid. Due to failing function complex sensors are superfluous.

Thus, a degree of diagnosis is achieved by function inhibition. If the machine no longer functions, it can not continue to be operated.

Preferably, in the cutting machine, the working means is designed as a cutting blade or pressing beam.

The power means can be designed differently. In particular, the force means is designed as a hydraulic cylinder. The hydraulic cylinder may be formed with one or both sides acted upon piston. In the case of pistons which can be acted upon on both sides, the working medium, in particular the cutting blade or the pressing beam, can not only be lowered but also lifted by means of the force means. When unilaterally acted piston this serves in particular to lower the working fluid, in this case in particular the cutting blade or the pressing beam. The lifting movement of the working medium takes place in particular via external means. In these external Means are preferably at least one spring, which cooperates with the working medium.

When the power means is designed as a hydraulic cylinder, it is considered preferable if a first line for hydraulic fluid is connected to a cylinder space of the hydraulic cylinder and this line continues in a branch line with second and third lines which extend via the two valves to the pump and to the tank continue. The first line thus splits into the branch line, hence the second and third line. These two lines are led separately via the two valves, namely the one line through the two valves to the pump, the other line through the two valves to the tank.

It is provided in particular that the respective valve is designed as a 4/3-way valve. This directional control valve thus has three switch positions with four connections.

It is considered particularly advantageous in the cutting machine when, in a first position of the two valves, a flow of hydraulic fluid through the two lines of the branch line is blocked, blocked in a second position of the two valves, a flow of hydraulic fluid through one of the two lines of the branch line is and the flow through the other line of the branch line is released, in a third position of the two valves, a flow through which one of the two lines of the branch line is released and the flow through the other line of the branch line is blocked.

When forming the force as a piston acted upon on both sides, the first line is preferably connected to a first cylinder space of the hydraulic cylinder, and a further line for hydraulic fluid connects the pump to a second cylinder space of the hydraulic cylinder. In particular, the hydraulic cylinder is designed such that the piston rod passes through the second cylinder space. The piston rod thus does not penetrate the first cylinder chamber. This results in concern of the substantially same pressure of the pump in both cylinder chambers different power ratios, since the piston area of the first cylinder chamber is greater than that of the second cylinder chamber.

When forming the power means with piston acted upon on both sides, it is preferably provided that for carrying out a lowering movement of the working medium, the two valves are in a position in which the flow from the pump to the power means is blocked and the flow from the force means to the tank is opened , As well as the pump hydraulic fluid promotes the further line to the power means. To perform a lifting movement of the working fluid is provided in both sides acted upon piston in particular that the two valves are in a position in which the flow from the pump via the valves to the power means open and the flow from the power to the tank is locked.

When the force is formed as a piston which can be acted upon on one side, it is considered to be particularly advantageous if the first line is connected to a cylinder space and the piston of the hydraulic cylinder can be reset by external means, counter to the impingement direction of the piston by hydraulic fluid. Preferably, the first line is connected to the cylinder space, which passes through the piston rod.

The external means is preferably designed as at least one spring, in particular these external means interact with the working means.

To perform a lowering movement of the working fluid in the formation of the force with unilaterally acted piston, it is considered particularly advantageous if the two valves are in a position in which the flow from the pump through the valves to the power means open and the flow from the power to Tank is locked. To perform a lifting movement of the working fluid in the case of a piston which can be acted upon on one side, the two valves are preferably in a position in which the flow from the pump through the valves to the power means is blocked and the flow from the force medium to the tank is opened.

Further features of the invention are set forth in the subclaims, the description of the following drawing and the drawing itself, wherein it is noted that all individual features and all combinations of individual features are essential to the invention.

Fig. 1 bis 9

für ein erstes Ausführungsbeispiel einer Schneidemaschine ein Hydraulikschaltbild zum Ansteuern eines Pressbalkens der Schneidemaschine über einen Hydraulikzylinder mit einseitig beaufschlagbarem Kolben, sowie eine Feder zum Anheben des Pressbalkens, veranschaulicht für verschiedene Schaltstellungen eines beim Hydrauliksystem Verwendung findenden 4/3-Wegeventils,

Fig. 10 bis 18

für ein zweites Ausführungsbeispiel einer Schneidemaschine ein Hydraulikschaltbild zum Ansteuern eines Pressbalkens der Schneidemaschine über einen Hydraulikzylinder mit doppelseitig beaufschlagbarem Kolben, veranschaulicht für verschiedene Schaltstellungen eines beim Hydrauliksystem Verwendung findenden 4/3Wegeventils,

Fig. 19 bis 27

für ein drittes Ausführungsbeispiel einer Schneidemaschine ein Hydraulikschaltbild zum Ansteuern eines Schneidmessers der Schneidemaschine über einen Hydraulikzylinder mit einseitig beaufschlagbarem Kolben, sowie eine Feder zum Anheben des Schneidmessers, veranschaulicht für verschiedene Schaltstellungen eines beim Hydrauliksystem Verwendung findenden 4/3-Wegeventils,

Fig. 28 bis 36

für ein viertes Ausführungsbeispiel einer Schneidemaschine ein Hydraulikschaltbild zum Ansteuern eines Schneidmesser der Schneidemaschine, über einen Hydraulikzylinder mit doppelseitig beaufschlagbarem Kolben, veranschaulicht für verschiedene Schaltstellungen eines beim Hydrauliksystem Verwendung findenden 4/3-Wegeventils.

In the drawing, the invention is illustrated by four embodiments, without being limited thereto. It shows in a simplified representation:

Fig. 1 to 9

for a first embodiment of a cutting machine, a hydraulic circuit diagram for driving a press beam of the cutting machine via a hydraulic cylinder with unilaterally acted piston, and a spring for lifting the press bar, illustrated for various switching positions of a 4/3-way valve used in the hydraulic system,

10 to 18

for a second embodiment of a cutting machine, a hydraulic circuit diagram for driving a press beam of the cutting machine via a hydraulic cylinder with double-acting piston, illustrated for various switching positions of a 4 / 3Wegeventils used in the hydraulic system,

Fig. 19 to 27

for a third embodiment of a cutting machine, a hydraulic circuit diagram for driving a cutting blade of the cutting machine via a hydraulic cylinder with unilaterally acted upon piston, and a spring for lifting the cutting blade, illustrated for various switching positions of a 4/3-way valve used in the hydraulic system,

FIGS. 28 to 36

for a fourth embodiment of a cutting machine, a hydraulic circuit diagram for driving a cutting blade of the cutting machine, via a hydraulic cylinder with double-acting piston, illustrated for various switching positions of a 4/3-way valve used in the hydraulic system.

figure description

The Fig. 1 to 9 , relating to the first embodiment, show for a cutting machine 1 a pressing beam 2, which is guided vertically in two lateral guides 3. This press bar 2 can be actuated by means of a hydraulic cylinder 4, which is provided with a piston 5 which can be acted upon on one side. In the hydraulic cylinder 4, a cylinder chamber 6 is thus formed, which passes through a connected to the piston 5 piston rod 7 of the hydraulic cylinder 4, further a further cylinder chamber 8, the piston rod 7 does not penetrate. In the cylinder chamber 8 thus a larger effective piston area is formed as in the cylinder chamber. 6

The piston rod 7 is led up out of the hydraulic cylinder 4 and connected at the end via a hinge 9 with the pressing bar 2. Above the press beam 2, a spring 10 is mounted, which acts via a hinge 11 on the pressing beam 2. Thus, when the piston rod 7 is moved downwards, it pulls the pressing bar 2 against the force of the spring 10 downwards. If no force is exerted on the pressing bar 2 via the piston rod 7 and the piston 5 is otherwise not locked, the spring 10 pulls the pressing bar 2 back into an upper end position. Stationary parts, which serve to guide the press beam 2 and the bearing of the spring 10, are designated by the reference numeral 12. This is in particular a machine frame.

Below the press beam 2 is a table 13 of the cutting machine 1, which has an upper, horizontally arranged table surface 14 for receiving cutting material 15 to be cut. This sliced product 15 is a cuboid stack which is formed from individual sheets, for example 1,000 sheets of paper or foil.

In order to be able to cut the stack of products 15, it is necessary to clamp it by lowering the press bar 2 against the material 15 to be cut between the press bar 2 and the table 13. Subsequently, by lowering a cutting blade of the cutting machine 1 in a vertical plane, in the swinging cut, the cutting of the cutting material 15th

The hydraulic system 16 of the cutting machine 1 for actuating the press beam 2 in the sense of lowering it has the hydraulic cylinder 4, one by means of an electric motor 17 drivable pump 18 for conveying the hydraulic fluid of the hydraulic system 16 and a tank 19 for the hydraulic fluid. Furthermore, the hydraulic system 16 between the hydraulic cylinder 4 and the pump 18 and between the hydraulic cylinder 4 and the tank 19 has two successive arranged 4/3-way valves 20 and 21. The respective directional control valve 20 or 21 can thus be converted into three different switching positions and in this case has four connections.

A line 22 is connected to the cylinder chamber 6 of the hydraulic cylinder 4 and branches in front of the directional control valve 20 in two lines 23 and 24. These parallel lines 23, 24 are continued from the directional control valve 20 to the directional control valve 21 and from the directional control valve 21 to the pump 18 and the Tank 19 out. Specifically, the line 23 is guided to the pump 18 and the line 24 is guided to the tank 19. Between the pump 18 and the directional control valve 21, another line 25 branches off to the tank. This line 25 is associated with a pressure relief valve 26.

The two-way valves 20 and 21 are identical. The function of the press bar 2 is only guaranteed, thus ensuring the control of the press bar 2 in terms of lowering only if both valves 20, 21 are in the same functional position. If one of the directional control valves is in the correct position, ie functional position, whereas the other directional control valve is in a different shifting position from this functional position, the function of the press beam 2 is blocked, whereby the drive of the press beam, thus the hydraulic cylinder 4, can not be acted upon functionally. Thus, the functionality of the press beam only results when the identical functional position of both valves 20, 21 is activated.

The Fig. 1 to 3 illustrate three schematics, which are run through during pressing in succession, however, show the Fig. 4 to 9 Conditions in which the functionality of the press bar 2 is not given.

According to Fig. 1 the pressing bar 2 is at top dead center. Both directional valves 20, 21 are in their middle position, thus in their locked position. It can thus get no hydraulic fluid from the pump 18 to the hydraulic cylinder 4 and no hydraulic fluid from the hydraulic cylinder 4 to the tank 19. At the hydraulic cylinder 4 is no pressure or delivery volume.

Fig. 2 shows the two-way valves 20, 21, which are transferred identically in the right shift position. Now, the pump side pending pressure or the delivery volume via the line 23 and the line 22 to the cylinder chamber 6 of the hydraulic cylinder 4 reach and it is still the hydraulic line 24 by means of the two-way valves 20, 21 locked. Since the pressure or the delivery volume is present at the hydraulic cylinder 4, the pressing beam 2 is moved downward against the material to be cut 15 and in this case the spring 10 is biased more.

According to Fig. 3 are the two-way valves 20, 21 in the identical left switch position. In this, the passage through the line 23, thus the passage of hydraulic cylinder 4 and pump 18 is blocked and the line 24 is released, so that when pulling the press bar 2 by means of the spring 10 hydraulic fluid from the cylinder chamber 6 can escape into the conduit 22 and from there via the line 24 to the tank 19th

The Fig. 4 to 9 show unequal valve positions of the two-way valves 20, 21, thus at least one directional control valve 20 and 21, which is not in its required for each step of the cutting machine function position, so that no movement of the press beam takes place. The malfunction is detected by the failing function. Due to this failing function, other sensors are superfluous. In particular, no limit switches are required. Since the functionality of the press bar is given only when activated identical functional position of both valves 20, 21, in a faulty position of the directional control valves 20, 21, as in the Fig. 4 to 9 is illustrated, the desired function does not take place.

The second embodiment according to the 10 to 18 differs from the first embodiment according to the Fig. 1 to 9 only in that instead of the hydraulic cylinder 4 with unilaterally acted upon piston now a two-sided acted upon piston is provided in the absence of the spring 10 and connection of the Line 22 to the cylinder chamber 8. The other cylinder chamber 6 is connected via a further line 27 to the line 25.

The 10 to 12 show again for this embodiment, the circuit diagrams that are traversed during pressing of the material to be cut 15 by means of the press bar 2 successively. The Fig. 13 to 18 show the states of the directional control valves 20, 21, where no movement takes place due to unequal valve position. The malfunction is recognized in these cases again by failing function.

Fig. 10 shows as shown in Fig. 1 the blocking position of the two-way valves 20, 21, whereby no hydraulic fluid through the lines 23, 24 is promoted. In this state, the pressing beam 2 remains in its fully raised position. To lower the press bar 2 on the cutting material 15, as it is in Fig. 11 is illustrated, with pending pressure or delivery volume due to activation of the pump 18 via the electric motor 17, the directional control valves 20, 21 now transferred to their left switching position, which hydraulic fluid from the pump 18 via the lines 25 and 27 can reach the cylinder chamber 6 and the Press bar 2 moves down. In this case, due to displacement by the piston 5, hydraulic fluid is discharged from the cylinder chamber 8, through the line 22 and the line 24 to the tank 19. The line 23 is blocked. When the pressing beam is lowered, the latter presses the material to be cut 15 against the table 13.

To raise the press bar 2 in its upper end position both valves 20, 21 in the in Fig. 12 shown shown right end position. Now, the line 24 is blocked and it passes hydraulic fluid from the pump both through the lines 23 and the line 22 to the cylinder chamber 8 of the hydraulic cylinder and via the lines 25 and 27 to the cylinder chamber 6 of the hydraulic cylinder 4. Since the acted piston surface, the cylinder space 8 is greater than that of the cylinder chamber 6, the piston 5 moves upward and raises the pressing bar 2 via the piston rod 7.

The Fig. 13 to 18 illustrate according to the Fig. 4 to 9 the switching positions of the directional control valves 20, 21, which are different and therefore no movement of the press beam 2 takes place. The malfunction is detected by failing function.

The representations of the Fig. 19 to 27 correspond completely to those according to the Fig. 1 to 9 with the difference that instead of a press bar 2, a cutting blade 28 is provided. This cutting blade 28 is mounted in obliquely arranged guides 3 of the stationary part 12, thus machine frame of the cutting machine 1. This should clarify that the cutting blade 8 is moved to cut the material to be cut 15 in the swinging section.

Incidentally, apply to this third embodiment according to the Fig. 19 to 27 the comments on the first embodiment according to the Fig. 1 to 9 with the only difference that reference is now made to the cutting blade instead of the reference to the press beam.

The fourth embodiment according to the FIGS. 28 to 36 corresponds completely to that according to the 10 to 18 , only with the difference that instead of a press bar 2, a cutting blade 28 is provided. In this respect, with regard to this fourth exemplary embodiment, reference is made to the statements relating to the second exemplary embodiment, wherein, instead of the reference to the pressing beam, reference is now made to the cutting blade.

LIST OF REFERENCE NUMBERS

1

cutting machine

2

pressing bars

3

guide

4

hydraulic cylinders

5

piston

6

cylinder space

7

piston rod

8th

cylinder space

9

joint

10

feather

11

joint

12

Stationary part

13

table

14

table top

15

be cut

16

hydraulic system

17

electric motor

18

pump

19

tank

20

4/3-way valve

21

4/3-way valve

22

management

23

management

24

management

25

management

26

Pressure relief valve

27

management

28

cutting blade

Claims (15)

Cutting machine (1) for cutting material to be cut (15), with a working means (2, 28) which can be acted on the material to be cut, wherein a lifting and / or lowering movement of the working means (2, 28) by means of a hydraulically operated force means (4 ) is effected, with a hydraulic system (16), the power means (4), a pump (18) for conveying hydraulic fluid, a tank (19) for hydraulic fluid and between the power means (4) and the pump (18) and between the force means (4) and the tank (19) has two successively arranged valves (20, 21) for controlling the flow of hydraulic fluid, wherein the functionality of the working means (2, 28) only when activated identical functional position of both valves (20, 21) given is. Cutting machine according to claim 1, wherein the working means (2, 28) as a pressing bar (2) or cutting blade (28) is formed. Cutting machine according to claim 1 or 2, wherein the force means (4) is designed as a hydraulic cylinder with one or both sides acted upon piston (5). Cutting machine according to claim 3, wherein a first line (22) for hydraulic fluid is connected to a cylinder space (6 or 8) of the hydraulic cylinder (4) and this line (22) is formed into a branch line with second and third lines (23, 24). continues, which continue through the two valves (20, 21) to the pump (18) and the tank (19). Cutting machine according to one of claims 1 to 4, wherein the respective valve (20 or 21) is designed as a 4/3-way valve. Cutting machine according to claim 4 or 5, wherein in a first position of the two valves (20, 21) a flow of hydraulic fluid through the two lines (23, 24) of the branch line is blocked in a second position of the two valves (20, 21) a flow of hydraulic fluid through a conduit (23 or 24) of the two lines (23, 24) of the branch line is blocked and the flow through the other line (24 or 23) of the branch line is released, in a third position of the two valves (20, 21) of the flow is released by a line (23 or 24) of the two lines (23, 24) of the branch line and the flow through the other line (24 or 23) of the branch line is blocked. Cutting machine according to one of claims 3 to 6, wherein when forming the force means (4) with both sides beaufschlagbarem piston (5), the first line (22) with a first cylinder chamber (8) is connected and a further line (27) for hydraulic fluid pump (18) connects to a second cylinder chamber (6). Cutting machine according to claim 7, wherein the piston rod (7) passes through the second cylinder space (6). Cutting machine according to claim 7 or 8, wherein, in order to carry out a lowering movement of the working means (2, 28), the two valves (20, 21) are in a position in which the flow from the pump (18) via the valves (20, 21 ) is blocked to the power means (4) and the flow from the power means (4) to the tank (19) is opened, and the pump (18) promotes hydraulic fluid via the further line (27) to the power means (4). Cutting machine according to one of claims 7 to 9, wherein for carrying out a lifting movement of the working means (2, 28), the two valves (20, 21) are in a position in which the flow from the pump (18) via the valves (20 , 21) to the force means (4) and the flow from the power means (4) to the tank (19) is locked. Cutting machine according to one of claims 3 to 6, wherein when forming the force means (4) with unilaterally acted piston (5) the first line (22) with a cylinder chamber (6) is connected and the piston (5) of the hydraulic cylinder (4) by means external means (10), against the loading direction of the piston (5) by hydraulic fluid, can be reset. Cutting machine according to claim 11, wherein the first conduit (22) is connected to the cylinder space (6) through which the piston rod (7) passes. Cutting machine according to claim 11 or 12, wherein the external means (10) are designed as at least one spring, in particular these external means (10) interact with the working means (2, 28). Cutting machine according to one of Claims 11 to 13, in which, in order to carry out a lowering movement of the working means (2, 28), the two valves (20, 21) are in a position in which the flow from the pump (18) via the valves (20 , 21) to the power means (4) and the passage from the power means (4) to the tank (19) is blocked. Cutting machine according to one of claims 11 to 14, wherein for carrying out a lifting movement of the working means (2, 28), the two valves (20, 21) are in a position in which the flow from the pump (18) via the valves (20 , 21) to the power means (4) and the flow from the power means (4) to the tank (19) is opened.

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