EP0620762B1 - Chopping device, and a chopper blade for such a device - Google Patents

Abstract

The chopping device (10) described has a driven rotating cylinder (18) fitted with chopper blades (28), the device being designed in particular to chop wood waste. The device is characterized in that the rotating cylinder (18) has an essentially smooth surface (26) and the chopper blades (28) have a triangular surface profile and are mounted with one side of the triangle against the surface (26) of the cylinder (18). A chopping device of this kind not only has high reliability and a long service life, but also produces chopped material with a very high degree of homogeneity and is economical in operation.

Description

The present invention relates to a comminution device with means for supplying objects, in particular wood waste, to a drivable, essentially cylindrical rotor device for comminuting objects and which has a substantially smooth surface, with knife elements, each knife element having a substantially triangular peripheral contour and each knife element can be fastened to a knife carrier element fastened on the surface of the rotor device and the knife element has a recess and the associated knife carrier element has a recess, both recesses being in alignment when the knife element is placed on the knife carrier element. The invention further relates to a knife element for a comminution device, the knife element being designed as a triangular plate element and releasably attachable to a knife carrier element. Such crushing machines are able, for. B. Pallets, chisels, coated chipboard, etc. to process in compact firewood chips. In addition to a favorable price / performance ratio, high reliability and a long service life are expected from such devices.

STATE OF THE ART

In known wood shredding machines, for example, a hopper is filled with wood waste by machine or by hand by tipping over a storage container. An existing hydraulically controlled feed unit presses the product onto a slow-running profile rotor device. This profile rotor device has, as knife elements, square plate elements which are arranged offset in a helical groove provided in the circumference of the rotor device, so that they run in the form of a spiral in the longitudinal direction of the rotor device. Such wood shredding machines have been used reliably for a long time. However, the manufacture of the rotor device is relatively complex since a helical rectangular groove has to be produced on the surface of the rotor device. Furthermore, there is a relatively large distance between the counter-knife device of the comminuting device and the rotor device with knife elements, which has an adverse effect on the duration of the comminuting process shredding wood waste or parts thereof in the longitudinal direction of the rotor device moved to one side, which has an unfavorable effect on the homogeneity of the shredded wood waste mass. In addition, the noise pollution when operating such comminution devices is not insignificant.

US-A-3 202 369 describes a shredding device for material of all kinds according to the preamble of claim 1. The knife element is fastened by inserting a fastening screw through the recess of the knife element and the knife carrier element and then screwing on a nut.

A comminution device is known from WO-A-8500303, in which triangular knives are welded onto a smooth rotor surface and a stiffening support is welded to each knife element.

In the literature reference Prof. Dr.-Ing. G. Spur & Prof. Dr.-Ing. T. Stöferle, manual for manufacturing technology, volume 3/1 Spanen, 1979, Carl Hansen Verlag, Munich Vienna, page A 43, a tool for cutting shaping is known, in which cutting tips with a triangular contour are used, which can be fastened to the tool carrier by means of screws.

PRESENTATION OF THE INVENTION

The invention is based on the technical problem of specifying a comminution device which is improved over the prior art mentioned and which has a simple and robust construction, can be produced economically and, in addition to high reliability and a long service life, ensures great homogeneity of the comminuted wood material. Furthermore, the invention is based on the problem of specifying an improved knife element with which the rotor device of a comminution device, in particular of the type mentioned at the beginning, can be fitted in a simple manner.

The shredding device according to the invention is given by the features of claim 1. The knife element according to the invention is given by the features of claim 7. Advantageous refinements of the comminution device or the knife element are the subject of further subclaims.

The comminution device according to the invention is accordingly characterized in that the knife elements are arranged with a triangular side directly on the surface of the rotor device, the recess of the knife element has an internal thread, the knife element is detachably fastened to the knife carrier element by a fastening screw that can be inserted from the recess of the knife carrier element, whereby the thread of the fastening screw in the internal thread of the knife element meshes. The knife elements are preferred here designed as equilateral triangular plate elements. Due to the smooth surface of the rotor device, the additional incorporation of the rectangular helical grooves, as in the known woodworking devices, can be omitted. Because the cutting tip can be formed with an angle of less than 90 degrees due to the triangular contour of the knife element, there is a better wedge effect than with the cutting corners of the square knife elements with 90 degrees. With the 90-degree cutting tip of the known knife elements, the wood waste is squeezed more than sheared, which has an unfavorable effect on the homogeneity and the processing time for reducing the wood waste. Due to the relatively good wedge effect at smaller angles of the cutting tip of the comminution device according to the invention, very good results are achieved in terms of processing time and comminution quality. When using equilateral triangular plate elements, a total of six cutting edges are created, which can be used one after the other by turning or turning the knife element to shred the wood material. At the same time, by arranging a triangular side of the knife element on the surface of the rotor device, an automatic locking of the knife element itself is achieved by placing it on. In addition, the assembly or replacement process of the knife elements is very simple.

In a structurally preferred embodiment of the comminution device according to the invention, the knife elements are arranged along two opposing screw lines in the circumferential direction on the rotor device. By means of these two opposing screw line arrangements, the wood material to be shredded in front of the rotor device is not shifted in one direction as in the known shredding devices. Rather, there is a more or less permanently uniform distribution of the wood material present between the knife elements and the counter knife device guaranteed.

In order to meet the relatively high loads and to ensure a long service life of the knife element, the knife element in the edge region of the recess has a cross-sectional reinforcement on at least one side, which is preferably conical. As a result of this cross-sectional reinforcement, the forces acting on the knife element during the comminution process are distributed over a larger cross-sectional area, so that lower stresses occur which reduce the stress on the knife element and increase its service life.

The knife carrier element preferably has a shape which is designed in accordance with the cross-sectional reinforcement of the knife element and into which the cross-sectional reinforcement is introduced before the knife element is fastened, as a result of which a certain locking is achieved.

Further embodiments and advantages of the invention result from the features further specified in the claims and from the exemplary embodiment specified below. The features of the claims can be combined with one another in any way insofar as they are not obviously mutually exclusive.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1

schematische Perspektive einer erfindungsgemäßen Zerkleinerungsvorrichtung mit einer Rotorvorrichtung mit dreieckförmigen Messerelementen in einer Übersicht,

Fig. 2

schematische Perspektivdarstellung einer Rotorvorrichtung mit dreieckförmigen, spiralförmig angeordneten Messerelementen und einer Gegenmesservorrichtung,

Fig. 3

Vorderansicht eines dreieckförmigen Messerelements,

Fig. 4

Seitenansicht eines Messerelements gemäß Fig. 3,

Fig. 5

Seitenansicht eines mit einem Messerträgerelement verschraubten Messerelement gemäß Fig. 3,

Fig. 6

perspektivische Explosionsdarstellung eines dreieckförmigen Messerelements mit zugehörigem Messertragelement und Befestigungsschraube und

Fig. 7

schematische Darstellung des Kämmens der Messerelemente in der Gegenmesservorrichtung, wobei Rotorvorrichtung und Gegenmesservorrichtung beabstandet zueinander angeordnet sind.

The invention and an advantageous embodiment and development thereof are described and explained in more detail below with reference to the example shown in the drawing. The features to be extracted from the description and the drawing can be used individually or in combination in any combination. Show it:

Fig. 1

schematic perspective of a comminution device according to the invention with a rotor device with triangular knife elements in an overview,

Fig. 2

schematic perspective representation of a rotor device with triangular, spirally arranged knife elements and a counter knife device,

Fig. 3

Front view of a triangular knife element,

Fig. 4

Side view of a knife element according to FIG. 3,

Fig. 5

Side view of a knife element screwed to a knife carrier element according to FIG. 3,

Fig. 6

perspective exploded view of a triangular knife element with associated knife support element and fastening screw and

Fig. 7

schematic representation of the combing of the knife elements in the counter knife device, the rotor device and counter knife device being arranged at a distance from one another.

WAYS OF CARRYING OUT THE INVENTION

A comminution device 10 has a funnel-shaped container device 12 on the upper side. The container device 12 has a rectangular top opening for filling with wood waste, with a transverse side of the container device 12 being arranged obliquely so that the wood waste to be filled can easily reach a plate level 14 on the underside. The wood waste located on the plate level 14 is pushed onto a rotor device 18 by means of a slide device 16. The slide device 16 is moved via a gimbal-mounted hydraulic cylinder, the drive and control elements of the hydraulic cylinder 20 not being shown in FIG. 1. The design of the drive and control elements is known to the person skilled in the art. The rotor device 18 is driven via a drive unit 22 by means of a V-belt 21 and rotates relatively slowly about its axis of rotation 23. The control devices for the drive unit 22 are not shown in FIG. 1 for the sake of clarity. On the side facing the viewer in FIG. 1, in the area of the rotor device, a perforated screen device 24 in the form of a circular section is arranged in regions around the rotor device 18, which has a hole pattern 25 with a predetermined spacing and diameter of the holes.

The cylindrical rotor device 18 has a smooth surface 26. The axis of rotation of the rotor device 18 is arranged substantially perpendicular to the sliding direction of the slide device 16. On the smooth surface 26 of the Rotor device 18 is arranged knife elements 28 which have the shape of equilateral triangular plate elements. Here, a triangle side lies directly on the smooth surface 26 of the rotor device 18. The anchoring of the knife elements 28 on the rotor device 18 is described further below.

The knife elements 28 are arranged in a spiral shape around the surface of the rotor device 18. The arrangement is selected so that the knife elements 28 form two opposing spirals (S1; S2) in the circumferential direction of the rotor device 18 (FIG. 2). At the level of the plate plane 14 there is a counter knife device 30 which, according to the outer contour of the knife elements 28, has triangular grooves 32 which form an angle of 60 degrees and are arranged in the transverse direction parallel to the axis of rotation 23. For reasons of clarity, the counter knife device 30 in FIG. 2 is spaced from the rotor device 18 and is shown in front of the rotor device 18. 1, the counter-knife device is located behind the rotor device, the grooves 32 facing the rotor device.

Below the perforated sieve device 24, a catch device 34 for the shredded wood material is shown schematically. The shredded wood material is removed from the catching device 34 by means of a transport screw, not shown, to the outside. Alternatively, it is also possible that the shredded wood material is suctioned off.

The shredding process now proceeds as follows. After the wood waste has been filled into the container device 12, the wood waste is fed to the rotor device 18 by means of the slide device 16. As a result of the rotation of the rotor device 18, the wood waste becomes between the knife elements 28 of the rotor device 18 and the counter knife device 10 pressed through, the wood waste is crushed by shear and crushing forces. The perforated screen device 24 surrounding the rotor device 18 determines the size of the shredded wood chips falling into the catching device 34. Depending on the hole diameter of the perforated sieve device 24, the chips can have different dimensions. By arranging the knife elements 28 in the form of two opposing spirals on the surface of the rotor device, the wood material to be shredded is distributed relatively uniformly over the entire width of the rotor device 18 at the shredding location between the counter knife device 30 and the knife elements 28. This ensures a relatively high homogeneity of the shredded wood material and also causes the knife elements 28 to be worn relatively evenly, whereas this is not the case with the known shredding devices, since the knife elements are arranged in the form of a single spiral and as a result of the rotation of the rotor device, the resulting wood material is shifted to one side of the rotor device depending on the inclination of the spiral, and the knives arranged there are therefore subject to greater wear.

By arranging two counter-rotating spirals equipped with triangular knife elements 28, one achieves twice the performance with the same power requirement compared to the known shredding devices. The equalization of the size reduction process over the entire width of the rotor device in the area of the counter-knife device 30 also results in significantly less noise during cutting than in the known devices.

This is due, among other things, to the fact that at least two knife elements 28 are present in a section transverse to the longitudinal axis of the rotor device 18 in the comminution device according to the invention, whereas only one knife is used in the known comminution devices is present, so that even relatively high squeezing noises arise during the shredding process.

The comminution effect is also improved by the advantageous choice of equilateral triangular knife elements 28, since here the cutting edge 35 is only 60 degrees, whereas, in the known comminution devices with the square plate knife elements, the cutting edge is 90 degrees. In the case of the latter plate elements, the wood material obtained is squeezed more, while in the knife elements according to the invention, the comminution takes place primarily by means of a shearing process due to the relatively sharp cutting edge.

In order to fasten the knife elements 28, a knife carrier element 36, which has a substantially triangular cross-sectional shape, is assigned to each knife element 28. The cross-sectional dimensions of the knife carrier element 36 are selected to be somewhat smaller than those of the knife elements 28. The knife carrier element 36 is fastened to the surface 26 of the rotor device 18 via weld seams 38. In this case, the knife carrier element 36 has a larger dimension in its longitudinal direction than the knife element 28 itself. The underside of the knife carrier element 36 is adapted to the cylindrical surface shape of the rotor device 18. The knife element 28 has a central recess 40 with an internal thread 42. Correspondingly, the knife carrier element 36 has a recess 44, the recess 44 and the recess 40 being in alignment when the knife element 28 is in place. To reinforce the knife element 28, an essentially conical cross-sectional reinforcement 46 is provided in the edge region of the recess 40 on both sides of the knife element 28. Correspondingly, the recess 44 of the knife carrier element 36 has a conical recess 45 with a linearly variable radius in the area of the cross-sectional reinforcement 46 of the knife element 28. For attaching the knife element 28 this is now placed on the knife carrier element 36, whereby a locking takes place by engaging the cross-sectional reinforcement 46 designed as a centering cone in the recess 45 designed as a receiving cone, and from behind a fastening screw 48 is inserted into the recess 44, which is then inserted into the internal thread 42 of the recess 40 is turned. The knife element 28 acts like a screw nut. This simple type of attachment makes it possible to easily release the connection between the knife carrier element and the knife element 28 if necessary, so that a worn cutting edge of the knife element 28 can be replaced by a sharp cutting edge by turning or turning the knife element. In addition, the screw can be temporarily secured against rotation by applying an adhesive to the internal thread. A total of six cutting edges are available in the knife element according to the invention, which can be used in a simple manner if required.

The arrangement of the triangular knife elements shown on the smooth surface 26 of the rotor device 18 is only one of the many possible variants. In particular, the pitch of the spirals and the number of knife elements in the circumferential direction can be adapted to the particular conditions required. It is also possible according to the invention to provide a plurality of opposing spirals equipped with knife elements.

The knife elements, which are often referred to as indexable inserts, are made of a special steel, in particular 16 NmCr5, and case-hardened in a known manner.

In contrast to the shredding device according to US-A-3,202,369, in the shredding device according to the invention there is a through hole with a receiving and centering cone (recess 45 or cross-sectional reinforcement 46). available. As a result, the sleeve present in the known device can be dispensed with, since the transverse forces are absorbed by the cross-sectional reinforcements according to the invention on the knife element and thus do not act on the screw thread. In contrast to the device according to US Pat. No. 3,202,369, the knife support for securing against rotation is not present on the knife carrier element, but rather directly on the rotor, ie the outer surface of the rotor forms the contact surface and thus the protection against rotation of the knife element. Likewise, there is no lowering on the rear side of the knife carrier element facing away from the knife element, since the processing of the knife element provides a flat surface for receiving a screw head. According to the screw head is not countersunk, so that the effort for providing a countersink is not necessary. It is also unnecessary to provide a sleeve in order to keep the thread free from transverse forces, since there is a cross-sectional reinforcement on the knife element.

In its basic form, the knife according to the invention preferably consists of an equilateral triangle. For a better service life, the triangle tips of the triangle are designed as surfaces, the width of which can be adapted to the conditions required in each case. By dispensing with the pointed configuration of the triangle corner point, a longer service life of the device is achieved according to the invention.

Instead of the smooth through bore within the knife (knife element) disclosed in US Pat. No. 3,202,369, a thread is attached according to the invention. The knife is thus releasably attached to the knife carrier element. It is not necessary to provide a mother. A security of the screw against loosening is given according to the invention in that either a locking washer is arranged between the knife and knife carrier element, which claws between the knife carrier and the knife element when the screw is tightened and / or an adhesive is provided within the thread. According to the invention, the arrangement of the knife elements on the rotor consists of two opposing screw lines. However, it has proven to be advantageous to fill the essentially V-shaped knife-free areas with additional knives. This results in further screw lines provided with knives. The distance from knife to knife on the circumference is determined by surface lines which have a distance from one another that is divisible in the rotor circumference. With this division, the knife carrier elements with the knife already screwed on are welded onto the rotor in such a way that the knives mesh with the least possible play in the counter knife.

According to the invention, the counter knife consists of one or more flat steel pieces with corresponding lengths. On one of the two long sides, the cutting edges are milled in the form of serrations so that a sharp corner that can be used for cutting is present on the upper and lower side.

The counter knife is screwed onto the knife carrier, which is fastened in the frame, preferably by means of countersunk screws. The counter knife is fixed in position with the countersunk head of the screw. When turning or replacing the counter knife, the countersink and countersunk screws always bring it into its original position.

In the exemplary embodiment shown schematically in FIG. 7, the knife elements 60 attached to the knife carrier elements welded on the rotor device 18 only mesh in the area of their tip in the corresponding recess 62 of the counter knife device 64. This is because the width of the knife elements 60 arranged on the rotor side is larger than the width of the recesses 62. A gap 66 is present between the rotor device 18 and the counter knife device 64. On the one hand, this has the consequence that in the region of the tip of a prong 68 of the counter knife device 64 an additional crushing edge is created, which has a favorable effect on the crushing of the filled, inhomogeneous material. In addition, it is ensured that elements 66 which are not suitable for comminution can fall through the gap 66, in particular nails which are hammered into the waste wood being fed in, and as a result the cutting edges of the knife elements 60 and the counter device 64 are not exposed to great wear.

Claims (7)

1. Size reduction device (10) for all types of material, especially wood,

   - having a drivable, essentially cylindrical rotor device (18) to which objects are fed for size reduction and which essentially has a smooth surface (26),

   - having blade elements (28),

   - - each blade element (28) having an essentially triangular peripheral contour and

   - - each blade element (28) being fastenable to a blade carrier element (36) fastened on the surface (26) of the rotor device (18) and

   - - the blade element (28) having a recess (40) and the associated blade carrier element (36) having a recess (44), both recesses (40; 44) lying in mutual alignment when the blade element (28) is mounted on the blade carrier element (36),

   characterized in that

   - the blade elements (28) rest with one side of a triangle directly upon the smooth surface (26) of the rotor device (18),

   - the blade element (28) has in the marginal region of the recess (40), at least on one side, an annular cross-sectional reinforcement (46) of conical outer contour and

   - the blade carrier element (36) has a recess (45) of conical inner contour, which recess is shaped in accordance with the cross-sectional reinforcement (46) of the blade element (28).
2. Size reduction device according to Claim 1, characterized in that the blade elements (28) are configured as equilateral triangular plate elements.
3. Size reduction device according to Claim 1 or 2, characterized in that the blade elements (28) are disposed along at least two opposite-running helixes (S1, S2) in the peripheral direction on the rotor device (18).
4. Size reduction device according to Claim 3, characterized in that the blade element (28) has a recess (40) having an internal thread (42) and the associated blade carrier element (36) has a recess (44), both recesses (40; 44) lying in mutual alignment when the blade element (28) is mounted on the blade carrier element (36) and the blade element (28) being detachably fastenable to the blade carrier element (36) by a fastening screw (48) which can be introduced from the recess (44) of the blade carrier element (36).
5. Size reduction device according to Claim 1, characterized in that the blade carrier elements (36) are fastened to the rotor device (18) by means of a weld connection (38).
6. Blade element (28) for a size reduction device according to one or more of Claims 1 to 5, the blade element (28) being configured as a triangular plate element and such that it is detachably fastenable to a blade carrier element (36), characterized in that the blade element (28) has in the marginal region of the recess (40), at least on one side, an annular cross-sectional reinforcement (46) of conical outer contour.
7. Blade element according to Claim 6, characterized in that

   - the blade element (28) has a recess (40) having an internal thread (42) and

   - the blade element is detachably fastenable to the blade carrier element (36) by a fastening screw (48) which can be introduced from the recess (44) of the blade carrier element (36), the thread of the fastening screw (48) engaging in the internal thread (42) of the blade element (28).

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