EP1216803A2 - Equalizing roll - Google Patents

Abstract

A rotatable cylindrical roll (7) carries annular discs (2,16,17,18) at an angle to the disc axis (15). On rotation the discs perform a wobbling movement, the movement area of each disc overlapping that of an adjacent disc. Discs are circular and adjacent discs are tangentially offset relative to each other by 90-150 [deg] around the roll. An independent claim is also included for a process for leveling a scattered layer of loose material using the claimed roll (1). The roll is positioned at a specific height onto the surface of a fleece (3) of scattered material on the conveyer belt and rotates against the belt conveying direction. The circumferential speed of the roll (7) is at least equal to the conveyer belt speed.

Description

The invention relates to a leveling roller and a method to even out a sprinkled on a conveyor belt Layer of free-flowing goods according to the generic term of Claims 1 and 11.

Free-flowing bulk goods are used to manufacture building boards such as wood shavings, wood chips (strands), wood fibers, straw chips or shredded paper with the addition of binders sprinkled on a conveyor or forming belt to form a fleece, to be pressed into plates. To be a constant to ensure high quality of the panels it is necessary that the scattered fleece as possible over the entire Length and width have a uniform, predetermined spreading height the conveyor and forming belts. Especially with the Manufacture of wood fiber boards (MDF) is on the forming belt a non-woven fabric with layer thicknesses of approx. 20 to 200 cm sprinkled on, to press sheet thicknesses from 4 to 40 mm. In order to comply with these specified spreading heights as precisely as possible, equalization rollers are often used, the Comb the excess spreading height or the irregularities.

Such a leveling roller is ready from Deppe / Ernst, Paperback of chipboard technology, 3rd edition 1991, Page 191 previously known. There is a spreading station for MDF boards shown in the case of continuously from a dosing hopper glued wood fibers are placed on spreading rollers. Due to the spreading rollers, the fibers become continuous promotional form tape sprinkled on the nonwoven fabric Plate press feeds. Because such a non-woven fabric on his Surface can have height differences of up to 10 cm, which leads to differences in density in the finished panels at the end of the spreading station a height-adjustable leveling roller intended. This leveling roller consists of one cylindrical roller body, on the outer surface of a large number of vertically protruding spines are arranged, which comb the excess fiber height, which then above the leveling roller is suctioned off. Such spiked rollers but have the disadvantage that combing back the direction of conveyance is only linearly in front of the spines existing hump-shaped irregularities and depressions are balanced, with lateral depressions by the Humps present linearly in front of the spines usually cannot be compensated are. Otherwise leave the relatively long Spines in the combed non-woven fabric running in the conveying direction parallel grooves, through which a ripple in the nonwoven fabric remains.

EP 0 794 854 B1 describes a device for leveling a Known wood fiber fleece, which contains a rotary roller, on the side by side a multitude of inclined elliptical Disks are arranged. The discs are in one Inclined at an angle of approx. 60 ° and thereby describe at one Rotation with respect to the nonwoven fabric a circular path. The fiber particles become continuous on the material web transversely to the conveying direction, so that also a transverse distribution the excess fiber hump occurs. But there everyone elliptical discs partially juxtaposed and Aligned at the same incline, all carry Panes always with the same depth of penetration in the same Transverse direction, so that when using such a leveling roller on the nonwoven fabric at least at a low rotation speed gives a sinusoidal serpentine pattern, that still has a ripple. Such a thing Structural patterns, however, are only likely to be connected in series Leveling rollers with different penetration depths and different starting roller positions can be avoided, but which requires a lot of equipment. Also if the elliptical discs individually or in groups different positions to the rotational position of the shaft results, at least even at a low rotational speed a non-woven fabric that does not automatically all Compensates for unevenness and still shows residual ripple can.

The invention is therefore based on the object at the outset called leveling roller and carried out with it To improve the process so that it is also in proportion low peripheral speeds a largely flat surface structure a scattered fleece made of free-flowing Bulk goods is accessible and this under the simplest design Design.

This object is achieved by the in claims 1 and 11 specified invention solved. Training and advantageous Embodiments of the invention are in the subclaims specified.

The invention has the advantage, at least with a radial one Phase shift of approximately 120 ° of the adjacent ring discs there is a continuous opposite side movement and depth of penetration results, the effects of which are similar to three-phase phase shift automatically become one on the entire surface constant leveling effect even at low Rotation speeds leads.

Due to the inclined circular washers there is a continuously changing penetration depth for each pane, the from the angular position of the toothed disc to Rotation position of the roller depends. Advantageously result thereby at least with an angular offset of approximately 120 ° of the adjacent ring washers an average depth of penetration, which is constant, so that even in the vertical direction an even milling and a compensation of the excess Fleece surface takes place. This is already with only a leveling roller advantageously a very precise one and even spreading height achievable, leading to high quality Building boards leads, their surface mostly hardly post-processing is required.

The invention also has the advantage that at least one approximate angular misalignment of 120 ° of the adjacent washers a constancy in the sum of the neighboring discontinuous ones Cross and depth movement is achievable, so that an even leveling basically at a peripheral speed the leveling roller is accessible, the conveying speed of the conveyor or forming belt corresponds without any residual ripple on the fleece surface remains. This also creates a throw of excess fiber material over the leveling roller largely prevented, so that a suction or a series connection several leveling rollers is unnecessary. At the same time, at a low peripheral speed the leveling roller prevents excessive wear, resulting in a long life of such a wear part leads. In particular, such a low rotational speed leads for an economic use of such Leveling rollers, which then only have low drive powers require and inexpensive because of low material loads are producible.

Fig. 1:

einen Ausschnitt einer Streustation mit einer Egalisierungswalze in Seitenansicht, und

Fig. 2:

eine Egalisierungswalze in Vorderansicht.

The invention is explained in more detail using an exemplary embodiment which is illustrated in the drawing. Show it:

Fig. 1:

a section of a scattering station with a leveling roller in side view, and

Fig. 2:

a leveling roller in front view.

In Fig. 1 of the drawing is a scattering station for fiberboard shown that a leveling roller 1 with inclined and inclined washers 2 for leveling a sprinkled Non-woven fabric 3 contains.

In the production of boards from free-flowing bulk materials provided with binders, such as wood fibers, glued wood fibers are sprinkled on a transport or forming belt 5 to a fiber fleece 3 from a dosing hopper 4 in a scattering station. The wood fibers are distributed as evenly as possible on a conveyor belt or forming belt 5 in order to be able to produce homogeneous fiber boards. Since fleece heights of up to 2 m in height and fleece widths of up to 5 m in width are scattered, in particular when scattering wood fibers, it cannot usually be avoided that the fleece surface has a ripple 6 with length differences of up to 10 cm in both the longitudinal and transverse directions ,
These differences in height lead to fluctuations in density and uneven plate surfaces after pressing, which are undesirable. A leveling roller 1 is therefore provided at the exit of the scattering station above the forming belt 5, which is intended to compensate for this residual ripple 6 and other height differences.
The leveling roller 1 is adjustable in height and connected to a drive which allows the leveling roller 1 to rotate at a constant speed as a function of the forming belt speed. Rotation speeds of 10 to 1,000 rpm are usually sufficient at normal forming belt speeds. Below the rotating leveling roller 1, the nonwoven fabric 3 is conveyed against the direction of rotation of the roller 1 at a constant conveying speed V to the plate press or, in the case of multilayer plates, to a further scattering station.

The leveling roller 1 consists of a cylindrical roller body 7 of a uniform diameter on one A large number of adjacent ring disks 2 are arranged are. This roller body 7 preferably has a diameter of 400 mm, but can also be used in diameter sizes from 200 to 800 mm. The roller 1 is centric Drive shaft or laterally attached bearing journal 8 equipped for storage and drive. The bearing journals 8 or the drive shaft is above on a stationary Appliance part 9 suspended adjustable in height, so that a Adaptation to different spreading heights is adjustable.

The discs 2 are ring-shaped and bear on it Scope a variety of ridges 10, preferably are tooth-shaped and through which the wood fiber material is taken against the direction of transport. Preferably these washers 2 as thin sheet metal rings in Widths from 1 to 5 mm are manufactured and have an outer diameter of approximately 500 mm, with a tooth height of approximately 50 mm is provided. On the toothed washer 2, depending on the given Speed and intended number of side by side arranged discs 2 a variety of small or one fewer number of larger teeth can be provided. Preferably have in practice ring plates 2 with 8 to 24 Proven teeth that are slightly acute angled against the direction of rotation 11 are formed and thereby a throw of the fiber material prevent largely on the combed fleece surface. The peripheral speed should be used to even out the surface the leveling roller 1 at least the conveying speed V on the form 5 or conveyor belt correspond.

The leveling effect of the proposed Roller 1 is primarily characterized by an overlapping range of motion of the adjacent washers 2, where the resulting direction of movement of each neighboring one Disc 2 changes continuously during rotation. Training the leveling roller 1 in particular by the arrangement the toothed washer 2 is shown in Fig. 2 of the drawing. The same parts are the same Reference numerals used as in Fig. 1 of the drawing.

The toothed ring disks 2 are punched out as a flat plane Sheet metal rings formed on the cylindrical roller body 7 be postponed. There are about 30 ring washers per Meters of roll length are provided side by side. On the roller body 7 are three guide grooves at a radial distance 12 of 120 ° provided, in which the fastening eyes 14 on the circular washers 2 can be inserted. The individual ring washers 2 opposite an orthogonal to the axis of rotation 15 arranged obliquely inclined. An initial slope is advantageous the first toothed washer 2 to the orthogonal Axis of rotation 15 of about 5 ° is provided, which with a disk diameter of 500 mm during the rotation a lateral Wobble movement of the disc of approx. 40 mm. Because every single one Ring gear rotates synchronously with the rotating shaft 8, creates a wobble movement in which the disc 2 in Area of contact with the nonwoven fabric 3 a steady oscillating transverse movement and vertical movement performs. This creates a constant change in the resulting Direction of movement that the fibers in front of each Toothed lock washer 2 not only forwards but also across Remove the conveying direction from the surface and so existing ones Compensate depressions and piles in the longitudinal and transverse directions.

The particularly smoothing effect results from the special arrangement of several adjacent panes 2 to one another, which is an advantageous addition of the overlapping individual movements cause. So the next to the starting disc 2 attached second washer 16 in the same inclination angle position to the orthogonal of the axis of rotation 15 on the roller body 7 positioned, but with a radial angular offset 12 of 120 ° and so spaced from the first disc 2, that the transverse movement areas partially overlap. there results as the smallest axial distance between the disks 2, 16 from each other an arrangement on which the two tooth lock washers touch at its closest point and as the largest intended Distance a distance from each other at which the Only slightly overlap transverse movement areas.

In addition to this second ring disk 16, a similar one is in turn Third ring disk 17 arranged, which is also the same Inclined to the orthogonal as the first ring disc 2. However, the third ring disk 17 is again one Radial angle 12 of 120 ° with respect to the second ring disk 16 staggered. Since all three ring washers 2, 16, 17 are radially offset from each other by 120 ° results in cheaper side placement to which the neighboring ones Discs 2, 16, 17 touch or at this narrowest point only have a small distance from each other, an overlap area of all three ring washers 2, 16, 17. Since each rotating ring disc 2, 16, 17 on the continuously conveyor belt 5 describes a sinusoidal serpentine line, result in the three radially offset by 120 ° Toothed washers 2, 16, 17 a constant resulting Action on the fleece surface, so that even at low Shaft speed almost no ripple on the fleece surface remains. This effect does not only occur in the side Overlap area, but advantageously also in the vertical overlap area, so that even by simple circular washers 2, 16, 17 a constant leveling height can be reached, although the individual disks 2, 16, 17 a fluctuation in height on its circumferential path during rotation against the fleece surface.

Even with the continuation of the similar arrangement of the ring washers 2, 16, 17 on the roller body 7 by an angular offset The fourth toothed washer 18 has 12 of 120 ° same radial alignment as the first ring washer 2. This radial position basically repeats after all three Disc arrangements so that all adjacent washer discs 2, 16, 17, 18 an overlap area against each other have, which is so additive with the in turn adjacent adds that an almost flat surface structure can be achieved , which is also particularly uneven on the side balances and the excess fibers in all directions distributed in front of the leveling roller 1. It has in particular the radial angular offset 12 of 120 ° was found to be optimal, because all neighboring motion components add to a constant resultant and so already with a single slow-running leveling roller 1 a row of flat fleece surfaces can be reached. there is a rapid wear of the toothed washers and a premature throwing of the removed wood fibers onto the equalized Fleece surface avoided.

There are other radial offset angles of the neighboring ones Disks 2, 16, 17, 18 in an angular range from 90 ° to 150 ° executable, the relatively flat at higher rotational speeds Create fleece surfaces. The inventive effect occurs at the latest at offset angles of 180 °, because here areas arise on the nonwoven fabric that are neither in the oscillating transverse movement still in the oscillating vertical movement overlap so that at least at lower Rotation speed can hardly avoid a ripple.

However, the inventive effect of the leveling roller also with other initial angles of inclination to the orthogonal the axis of rotation 15 reachable. Result at larger angles of inclination in any case larger axial distances between the adjacent toothed ring disks 2, 16, 17, 18, whereby the inventive Equalization effect a higher speed difference between the rotational speed and the conveying speed V requires the additive effect to be constant to reach. With smaller initial inclinations of the toothed washer 2 is the overlap area in cross or Axial direction relatively small, so that in practice has shown slower cross distribution.

The advantageous radial offset arrangement of the inclined Toothed washers 2, 16, 17, 18 is simple due to different spacing sleeves between the neighboring ones Ring discs 2, 16, 17, 18 can be produced. So they will Toothed washers 2, 16, 17, 18 by inserted in the guide grooves Threaded rods 19 axially fixed. The Threaded rods 19 through the eyelets provided in the rings 14 inserted, between the adjacent eyelets Spacers are arranged. With the intended leveling roller 1 between the adjacent ring washers 2, 16, 17, 18 spacer sleeves of 20, 30 and 40 mm length arranged, so that there is a sufficiently large lateral overlap area results and the adjacent washers 2, 16, 17, 18 at their closest point a distance of a few Have millimeters to clamp the fibers there to prevent. At the next adjacent toothed washer 2, 16, 17, 18 the same sleeve lengths are used, however radially offset by an angle of 120 ° between the Disks 2, 16, 17, 18 arranged. This will, as it were, for everyone other adjacent ring washers 2, 16, 17, 18, so that the intended radially offset itself Positioning at the same angle to the orthogonal the axis of rotation 15 sets. At the ends of the rollers, the Provide threaded rods with nuts and tighten them against each other, so that the ring washers 2, 16, 17, 18 against each other and are fixed on the roller body 7 and the invention Represent leveling roller 1.

Such a toothed washer 2, 16, 17, 18 could also by an inseparable welded connection on the roller body 7 be attached. The washers 2, 16, 17, 18 do not have to be formed as continuous ring surfaces, but can gaps also at regular or irregular intervals or have interruptions. The washers 2, 16, 17, 18 can also be arranged on the roller body 7 in such a way that just a dense sequence of elevations, teeth 10 or Spikes protrude from the roller surface. It is also conceivable that the toothed ring arrangement directly from a base body is worked out or manufactured using a mold. Such a leveling roller 1 is not only for leveling of a non-woven fabric, but also for all others sprinkled nonwovens made of free-flowing goods can be used.

Claims (11)

Leveling roller for leveling a layer (3) of free-flowing goods sprinkled on a conveyor belt (5), in particular glued wood fibers, which consists of a rotatable cylindrical roller (7) on which a large number of obliquely inclined ring disks (2, 16, 17, 18) are arranged which perform an overlapping wobble movement during rotation, characterized in that the annular disks (2, 16, 17, 18) are round and circular, the adjacent obliquely inclined annular disks (2, 16, 17, 18) against one another have a tangential angular offset (12) of 90 to 150 °. Leveling roller according to claim 1, characterized in that the annular disks (2, 16, 17, 18) consist of a continuous sheet metal ring or one provided with interruptions or gaps, which is attached to or on a roller (7). Leveling roller according to claim 1 or 2, characterized in that elevations, in particular teeth (10) or spikes, are provided on the outer circumference of the annular disks (2, 16, 17, 18). Leveling roller according to one of the preceding claims, characterized in that the annular disks (2, 16, 17, 18) are designed as flat, corrugated or structured sheet metal disks and are arranged on or on the circumference of the roller. Leveling roller according to one of the preceding claims, characterized in that the annular disks (2, 16, 17, 18) are arranged on the roller (7) in such a way that they have an inclination angle of 3 to an orthogonal to the axis of rotation or rotation (15) Form 30 °. Leveling roller according to one of the preceding claims, characterized in that the adjacent ring disks (2, 16, 17, 18) are arranged tangentially offset by 120 °. Leveling roller according to one of the preceding claims, characterized in that the ring surface or the elevations (10) protrude from the peripheral surface of the roller (7), in particular in a range from 30 to 130 mm. Leveling roller according to one of the preceding claims, characterized in that the elevations are designed as teeth (10) or spikes which protrude over the circumference of the ring surface at a distance of 10 to 100 mm and tooth (2, 16, 17, 18) or represent barbed washers. Leveling roller according to one of the preceding claims, characterized in that the axial spacings of the adjacent ring disks (2, 16, 17, 18) are at least so large that the ring disks touch at the closest point and are at most so large that the wobbling ones Areas still overlap. Leveling roller according to one of the preceding claims, characterized in that the annular discs (2, 16, 17, 18) have an outer diameter of 400 to 600 mm, that the angle of inclination with respect to the orthogonal is 5 to 10 ° and the distances between the adjacent annular discs ( 2, 16, 17, 18) are formed by at least three different spacing lengths of 20 to 60 mm. Method for leveling a sprinkled layer (3) of free-flowing goods with a leveling roller (1) according to one of the preceding claims 1 to 10, characterized in that the leveling roller (1) at a predetermined height on the surface of the scattered fleece (3) above of the conveyor or forming belt (5) is positioned and rotates counter to the conveying direction of the forming (5) or conveyor belt, the peripheral speed of the roller (7) corresponding at least to the conveyor belt speed (V).

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