EP1270472B1 - Web tension control device for a corrugated board machine - Google Patents

Abstract

The mechanism for controlling the tension of a web (4) being wound on to a main roller (21) in a corrugated cardboard making machine comprises auxiliary support rollers (28, 29). These are mounted on arms which swivel about the axis (23) of the main roller.

Description

The invention relates to a device for regulating the web tension a moving material web, in particular a paper web, in a paper processing machine, such as B. a corrugated board, according to the preamble of claim 1.

A generic device for controlling the web tension of a moving material web is known from JP 54-103960 A. This device comprises a machine frame on which a first roller is mounted is. The first roller is connected to a swivel arm which a second roller is mounted. A material web is around the two Rolled out. By pivoting the second roller about the first Roller is the angle of wrap of the material web around the first roller variable. A disadvantage of this known device is that an exact Setting the web tension after the first roll is not possible is.

From GB 954 934 A are several folding devices for folding a moving paper web known. By folding, the elasticity becomes and improves the softness of the paper for certain applications. The Folding the paper web is between two moving conveyor surfaces achieved, which have a different direction of movement. Around to increase the friction between the conveying surfaces and the paper web, can be fed moisture of the web before the folding device become.

US 5,049,216 discloses a device for controlling the curvature a corrugated sheet. This includes a humidity detection sensor, which detects the moisture of a corrugated web. Based on the moisture value determined by the sensor becomes the lower one or upper cover sheet of the corrugated board web supplied such water, that the moisture profiles of the webs are essentially identical are. This will cause a distortion of the corrugated sheet during drying prevented.

DE 740 238 C and CH 292 425 A each have a device for controlling the web tension of a moving material web. Even with these two devices, the web tension can not be exact and easy to set.

From WO 00/00347 a plant for the production is laminated on one side Corrugated known in which a cover sheet and a corrugated sheet of corrugated manufacturing unit be supplied. The cover sheet is going ahead led around a cylinder, in whose surface numerous openings are provided, through which water vapor flows out to the water entry to increase in the cover sheet. By this arrangement, the web tension the cover sheet not defined regulated. A disadvantage of this Arrangement is further that the configuration of the cylinder with the corresponding Steam channels is extremely complicated. Furthermore escapes a large amount of steam in the peripheral areas of the Cylinders that are not wrapped by the cover sheet, unused. It is thus extremely difficult, due to the not exactly determinable supplied water vapor amount the friction between the cylinder and the cover sheet and thus the adjusting itself behind the cylinder web tension to predict and adjust.

The invention is based on the object, a device for control To create the web tension of a moving web, in which the Web tension can be adjusted as accurately and easily as possible.

The object is achieved by the in the characterizing part of claim 1 specified characteristics solved. The essence of the invention is that a moistening unit is provided for supplying moisture to the material web. By moistening the material web is the friction increased between the first roller and the material web.

A further advantageous embodiment of the invention results from the Under claim.

Fig. 1

eine Seitenansicht eines Ausschnitts einer Wellpappe-Anlage mit einer Bahnspannungs-Regelungs-Einheit gemäß einer ersten Ausführungsform,

Fig. 2

eine Draufsicht von oben auf die Bahnspannungs-Regelungs-Einheit gemäß Fig. 1,

Fig. 3

eine Seitenansicht der Bahnspannungs-Regelungs-Einheit gemäß Fig. 1 in einer ersten Position,

Fig. 4

eine Seitenansicht der Bahnspannungs-Regelungs-Einheit gemäß Fig. 1 in einer zweiten Position,

Fig. 5

eine Seitenansicht eines Ausschnitts einer Wellpappe-Anlage mit einer Bahnspannungs-Regelungs-Einheit gemäß einer zweiten Ausführungsform,

Fig. 6

eine Seitenansicht der Bahnspannungs-Regelungs-Einheit gemäß Fig. 5 in einer ersten Position und

Fig. 7

eine Seitenansicht der Bahnspannungs-Regelungs-Einheit gemäß Fig. 5 in einer zweiten Position.

Additional features and details of the invention will become apparent from the description of two embodiments with reference to the drawings. Show it:

Fig. 1

a side view of a section of a corrugated cardboard plant with a web tension control unit according to a first embodiment,

Fig. 2

1 is a plan view from above of the web tension control unit according to FIG. 1,

Fig. 3

1 is a side view of the web tension control unit according to FIG. 1 in a first position,

Fig. 4

1 is a side view of the web tension control unit according to FIG. 1 in a second position,

Fig. 5

a side view of a section of a corrugated cardboard plant with a web tension control unit according to a second embodiment,

Fig. 6

a side view of the web tension control unit of FIG. 5 in a first position and

Fig. 7

a side view of the web tension control unit of FIG. 5 in a second position.

In the following, with reference to Figures 1 to 4, a first Embodiment of the invention described. A plant 1 for the production a single-sided laminated corrugated board web 2 has a cover sheet feeding unit 3, in which a cover sheet 4 to several deflection rollers 5 deflected and to a preheating known as preheat cylinder 6 is led around to heat the cover sheet 4. Subsequently the cover sheet 4 is passed through a web tension control unit 7, which serves to adjust the web tension of the cover sheet 4 and will be described in detail below. Subsequently, the cover sheet 4 fed via further deflection rollers 5 a corrugated cardboard manufacturing unit 8. The corrugated board manufacturing unit 8 is supplied by a corrugated web feeding unit 9 fed as a corrugated web 10 designated paper web. In the Corrugated web feed unit 9, the corrugated web 10 at a plurality of deflection rollers 5 and two also known as preheating cylinder preheating rollers 11 passed and then the corrugated board manufacturing unit 8 supplied. The latter has a corrugated unit 12, in which the corrugated web 10 is provided with a corrugation. Subsequently, the corrugated corrugated web 10 past the gluing unit 13 and in a pressing unit 14 with the on a also called preheat cylinder Preheating roller 15 and around a web tension sensor 16 around Covering 4 joined together. The finished glued corrugated board 2 is discharged via a transport unit 17 upwards and on a shelf 18 stored temporarily. In the units 3, 8, 9, 12, 13, 14, 17 acts it is long known elements of a corrugated plant 1.

In the following, the structure of the web tension control unit 7 will be described in more detail. The unit 7 has a relative to a machine frame 19 in bearings 20 rotatably mounted, heated from the inside with steam main roller 21. The roller 21 has end projecting bearing pins 22 which are mounted in the bearings 20. The roller 21 is rotatable about a rotation axis 23. Between the machine frame 19 and the roller 21 is mounted on both bearing journals 22 a bearing 24 rotatably mounted disk 25 having two radially projecting arms 26 and 27 which are offset by an angle b of b ≈ 60 ° to each other, where other angles b can be used. Between the opposite arms 26 and 27 of the two discs 25, a front lap roller 28 and a rear lap roller 29 is rotatably supported. The rollers 28 and 29 are rotatable about respective axes of rotation 30 and 31, respectively. The axes of rotation 23, 30 and 31 are parallel to each other. The discs 25 including the rollers 28 and 29 are pivotable by a chain drive 32 with respect to the axis of rotation 23. For this purpose, the disks 25 have a circumferential toothed rim 33 with a diameter D _Z. To the sprockets 33, a chain 34 is guided in each case, which is guided on the drive side by two sprockets 36 connected to a drive shaft 35. The drive shaft 35 is mounted at both ends in bearings 37 relative to the machine frame 19. The shaft 35 can be driven by a motor 38 connected to it. The sprockets 36 have an outside diameter D _K. The gear ratio between the small sprocket 36 and the large sprocket 33 is D _Z / D _K ≈ 4, although other ratios are possible. The main roller 21 is rotatably driven by a motor 39 connected to the bearing pin 22, wherein the tangential outer peripheral speed of the roller 21 is designated by v _W. The unit of the two discs 25 together with arms 26 and the rollers 28 and 29 is referred to as a support device.

In the area of supply of the cover sheet 4 to the unit 7, a moistening unit 40 is provided which sprays water vapor onto the side of the cover sheet 4, in FIGS. 3 and 4 the top side, which subsequently faces the main roll 21. The cover sheet 4 has, before reaching the main roller 21, a speed which is designated by v _B. The cover sheet 4 is passed through the nip between the roller 29 and the roller 21 and then through the nip between the roller 28 and the roller 21, the cover sheet 4 being passed around the rollers 21, 29 and 30. The cover sheet 4 abuts the main roll 21 over a variable angle of wrap a.

To determine the web tension is in the unit 8 between the Preheating roller 15 and the pressing unit 14 of the web tension sensor 16 is provided, which measures the tension of the cover sheet 4 and a corresponding Measuring signal via a line 41 to a central control unit 42 there. The control unit 42 is connected via lines 43 and 44 to the motors 38 or 39 connected.

In the following, the function of the web tension control unit 7 will be described. The web tension of the cover sheet 4 after the unit 7 can be influenced by two sizes. One is how fast the main roller 21 is driven. To brake the cover sheet 4, ie to increase the web tension behind the unit 7, the peripheral speed v _{W of} the main roller 21 is smaller than the speed v _{B of} the cover sheet. In the most extreme case, the main roller 21 does not rotate. Another way to change the web tension is the change in the wrap angle a of the cover sheet 4 about the main roller 21. Thereby, the frictional force between the surface of the main roller 21 and the cover sheet 4 is changed.

In the position of the rollers 28 and 29 shown in Fig. 3, the wrap angle a is the smallest, in the present geometry applies: a ≈ 10 °. In this arrangement, the cover sheet 4 is supplied from the cover sheet feeding unit 3 of the web tension control unit 7 and passes first the moistening unit 40 which sprays water vapor on the top of the cover sheet 4 and thus the friction between the cover sheet 4 and the main roll 21 is increased compared to a dry cover sheet 4. Subsequently, the cover sheet 4 is slightly deflected at the roller 29 and passed over a wrap angle a on the main roller 21 and then deflected to the roller 28 and discharged to the corrugated cardboard manufacturing unit 8. The web tension sensor 16 continuously measures the web tension of the cover web 4. Should the web tension be too low, the control unit 42 sends corresponding signals to the motors 38 and / or 39. To increase the web tension, the speed v _{W of} the main web Roller 21 can be reduced. If this is not sufficient, then the rollers 28 and 29 are pivoted clockwise via the motor 38 and the chain drive 32, whereby the angle of wrap a increases. A position with a large wrap angle a is shown in FIG. 4. By supplying the water vapor, the friction between the cover sheet 4 and the main roller 21 is increased, which is particularly desirable for the adjustment of the web tension. Therefore, the water vapor is supplied on the side of the cover sheet 4, which faces the main roller 21. In addition, the cover sheet 4 must have a certain moisture, so that the bond produced in the pressing unit 14 can be made with the corrugated web 10 properly. By means of the web tension control unit 7, it is possible to keep the web tension of the cover web 4 at the web tension sensor 16 constant, ie immediately before the bonding to the corrugated web 10. Typically, with increasing speed v _{B of} the cover sheet 4 in order to maintain a constant web tension on the web tension sensor 16, the wrap angle a must be increased.

In the following, with reference to Figures 5 to 7, a second Embodiment of the invention described. Identical parts receive the same Reference numerals as in the first embodiment, to the description thereof is referenced. Functionally similar but constructive different parts receive the same reference numerals with an upper part Line. The main difference compared to the first embodiment is that the cover sheet 4 is not, as in the first embodiment, performed substantially below the main roller 21 but is guided over the main roller 21. Accordingly, the Moistening unit 40 'arranged below the cover sheet 4 to, as in the first embodiment, the main roller 21 facing side to moisten with steam. In Fig. 6 is a corresponding to Fig. 3 Position of the rollers 28 and 29 shown, in which the wrap angle a is minimal. In the arrangement according to the second embodiment it is possible, as shown in Fig. 6, a wrap angle to achieve a = 0 °, d. H. the cover sheet 4 wraps around the main roller 21 not at all and is only led around the roller 28 and discharged through the gap between the roller 29 and the roller 21. Of the Friction resistance in this arrangement is compared to all others Positions of the rollers 28 and 29 least. By pivoting the rollers 28 and 29 about the rotation axis 23 in the counterclockwise direction the wrap angle a is increased. In Fig. 7 is a Situation with a very large wrap angle of a ≈ 270 °. Advantageous to the second embodiment over the first Embodiment is that a larger interval of wrap angles is adjustable, in the present case 0 ° ≤ a ≤ 270 °. There are too larger wrap angle a adjustable.

Claims (2)

1. A device (7) for regulating the tension of a moving web of material (4), in particular a web of paper in a paper-working machine such as a corrugating machine, comprising

   a) a machine frame (19);

   b) a first roller (21) that is mounted for rotation about a first axis of rotation (23) in relation to the machine frame (19), taking up a web of material (4) showing a direction of transport by an angle of contact (a);

   c) a supporting device (25, 26, 27, 28, 29),

   i) which supports itself on the machine frame (19),

   ii) which is mounted for pivoting about the first axis of rotation (23) by a pivoting drive (32), and

   iii) which supports at least a second roller (28, 29) mounted for rotation about a second axis of rotation (30, 31) that is substantially parallel to the first axis of rotation (23); and

   d) wherein the angle of contact (a) of the web of material (4) on the first roller (21) is modifiable by the at least one second roller (28, 29) being pivoted about the first roller (21) for influencing the web tension of the web of material (4),

      characterized in that

   e) a web-tension-measuring device (16) is provided upstream of the at least second roller (28, 29), taking the tension of the web of material (4),

   f) a control unit (42) is provided, which is connected to the web-tension-measuring device (16) and the chain drive (32) for its regulation, for data transmission, controlling the tension of the web of material (4),

   g) a humidifier unit (40; 40') is provided for the supply of humidity to the web of material (4),

   h) the humidifier unit (40; 40') is disposed upstream of the first roller (21) and/or second roller (28; 29) along the web of material (4), and

   i) the humidifier unit (40; 40') is disposed on a side of the web of material (4) that is turned towards the first roller (21).
2. A device according to claim 1, characterized in that the humidifier unit (40; 40') is a unit for the delivery of water vapor.

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