Counter-blade

Abstract

The present invention relates to a counter-blade, in particular, for a wood chipper, for producing wood chips, comprising at least one cutting edge made of a hard material, and a support surface leading to the cutting edge. According to the present invention, the cutting edge is made up of a plurality of hard material elements that are arranged next to one another along the cutting edge on a main member. This results in a counter-blade having a long service life.

Claims

1. A counter-blade comprising a plurality of segments fastened on a support surface, the support surface having at least a first edge, and arranged in a row next to one another, each segment comprising a basic body fastened on the support surface and having a second edge extending past the first edge, a plurality of adjacent first elements provided on the second edge, the plurality of adjacent first elements comprising a first material having at least one of a wear resistance greater than a wear resistance of steel, a cobalt content of between 3.0 and 25 percent by weight, and a grain size within a range of 10 m and 30 m, defining a cutting edge each two adjacent first elements having a first transition defined therebetween, and a plurality of adjacent protective elements provided on the second edge joined in a flush manner to the adjacent first elements or arranged spaced by a gap away from the plurality of first elements, the plurality of adjacent protective elements comprising a second material which is one of the same as the first material or different from the first material, each two adjacent protective elements having a second transition defined therebetween, wherein each of the second transitions between each two of the adjacent protective elements are arranged in a direction of an extension of the cutting edge so as to be spatially offset with respect to the first transitions between each two of the adjacent first elements.

2. The counter-blade as claimed in claim 1, wherein the first elements are configured as geometric shapes, each geometric shape including a first edge defining a part of the cutting edge, and a second edge having a length less than a length of the first edge, and the geometric shapes are arranged next to one another in a row along a surface delimited by their second edges.

3. The counter-blade as claimed in claim 1, wherein at least one of the basic bodies comprises a recess into which the first elements are admitted in a flush manner to define a front end face of the at least one basic body or in a flush manner to define a substantially planar surface, or the first elements are admitted in such a manner into the recess that they project beyond the front end face.

4. The counter-blade as claimed in claim 1, wherein a material thickness of the first elements is chosen to be greater than a material thickness of the protective elements.

5. The counter-blade as claimed in claim 1, wherein one of a material thickness of the first elements or a material thickness of the protective elements is chosen to be different for at least one of the basic bodies.

6. The counter-blade as claimed in claim 1, wherein further comprising a cover plate that is mounted on the at least one basic body and is connected directly or indirectly to the protective elements or the cutting edge.

7. The counter-blade as claimed in claim 6, wherein the at least one basic body comprises a first steel and the cover plate comprises a second steel, the second steel having a hardness greater than a hardness of the first steel.

8. The counter-blade as claimed in claim 6, wherein the at least one basic body defines a web between the protective elements and the cover plate.

9. The counter-blade as claimed in claim 6, wherein the at least one basic body, on the side remote from the cutting edge, defines a support plane along which the cover plate is held in a flat manner.

10. The counter-blade as claimed in claim 6, wherein at least one basic body comprises at least one hole defined therein, configured to receive at least one fastening element, the at least one fastening element being configured to fasten the at least one basic body onto a carrier, and the cover plate comprises bores for receiving mounting screws for fastening the cover plate on the at least one basic body, wherein in the mounted state the cover plate covers the at least one hole defined in the at least one basic body.

11. The counter-blade as claimed in claim 6, wherein the cover plate comprises a forcing portion.

12. The counter-blade as claimed in claim 1, further comprising a second cutting edge.

13. The counter-blade as claimed in claim 1, wherein at least one basic body comprises a notch defined in a portion thereof, configured to receive a notch defined on a portion of a carrier, or a positioning attachment configured to receive a positioning attachment on the carrier.

14. The counter-blade as claimed in claim 13, wherein the notch, or the positioning attachment, is arranged along an end-face stop surface of the at least one basic body located opposite the cutting edge, or the notch, or the positioning attachment, is arranged along a mounting plane of the at least one basic body.

15. The counter-blade as claimed in claim 6, wherein the cover plate comprises a notch or a positioning attachment on an end face thereof spaced away from the cutting edge.

16. The counter-blade as claimed in claim 11, wherein the forcing portion is a threaded bore.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) FIG. 1 shows a top view of a counter-blade 10 with one cutting edge.

(2) The cutting edge 14 is formed from a row of cuboid hard material elements 12 which are arranged along the cutting edge 14. Protective elements 13, offset in relation to the hard material elements 12, are arranged joining directly to the hard material elements 12. The protective elements are also formed from a hard material. In the exemplary embodiment shown, the hard material elements 12 and the protective elements 13 are produced from hard metal. Separated by a narrow web 28, following the protective elements 13, cover plates 30 are fastened, each with two mounting screws 34, on in each case one basic body 20 which is concealed by the cover plates 30, the protective elements 13 and the hard material elements 12, as is shown in FIGS. 2, 3 and 5. The hard material elements 12, together with the cover plates 30 and the web 28 arranged in between, form a support surface 29 which leads to the cutting edge 14.

(3) With the protective elements 13 and hard material elements 12 arranged in rows thereon, a cover plate 30 shows the outline of a segment 16 of the counter-blade 10. The counter-blade 10 is formed, in the exemplary embodiment shown, from eight segments 16 arranged in a row next to one another. The segments 16 are fastened on a carrier 11 for this purpose. In each case six hard material elements 12 per segment 16 form, in this case, a cutting edge portion 18 which is marked by a double arrow, the cutting edge portions 18 which are arranged in a row next to one another provide the cutting edge 14.

(4) Along a stop face 15, against which the segments 16 abut at the rear on a corresponding wall of the carrier 11, the carrier comprises positioning attachments 17. The positioning attachments engage in positioning receiving means 23, 35 mounted on the basic body 20 and the cover plate 30, as is shown in more detail in FIGS. 2 and 4.

(5) A continuous threaded bore 33 is provided in each cover plate 30 between the mounting screws 34.

(6) During mounting, the basic bodies 20 are fastened on the carrier 11 in such a manner that the cutting edge 14 protrudes beyond the carrier 11. In this case, the positioning attachments 17 and the positioning receiving means 23 serve for the quick and precise alignment of the individual basic bodies 20 in relation to the carrier 11. The cover plates 30 are then mounted on the basic bodies 20. Here too, the second positioning receiving means provided on the cover plate 30 serves for the simple positioning of the cover plate 30 in relation to the carrier 11 and consequently in relation to the already mounted basic body 20. Provided with the segments 16 of the counter-blade 10, the carrier 11 can then be mounted, for example, on a wood chipper to create wood chippings, in such a manner, that the cutting edge 14 is located opposite cutters which are arranged on a rotating roller of the wood chipper and are moved past the counter-blade 10.

(7) In operation, the wood to be shredded is fed by corresponding conveyor units beyond the support surface 29 to the cutting edge 14. The cutters of the wood chipper (not shown) are moved past the cutting edge 14 coming from the viewing direction in the representation. Wood which protrudes beyond the cutting edge 14 is shredded in this case.

(8) The cutting edge 14 is advantageously formed from a plurality of hard material elements 12. Hard material elements 12 show a low amount of wear, as a result of which a long service life of the counter-blade 10 is achieved. As a result of the small size of the individual hard material elements 12, the bending stress of the individual hard material elements 12 is low such that fractures are able to be extensively avoided. Should a hard material element 12, nevertheless break, for example, caused by great mechanical stress by a hard material inadvertently being introduced into the cutting gap, the breakage is limited to the relevant hard material element 12 and does not progress further into the adjacent hard material element 12. As a result of the design of the counter-blade 10 from a plurality of adjacently arranged hard material elements 12, an extended breakage along the cutting edge 14 formed from hard metal can consequently be avoided and the counter-blade 10 can continue to be used. If, nevertheless, there is greater damage to a cutting edge portion 18 or if a cutting edge portion 18 is worn prematurely as a result of irregular stress along the cutting edge 14, the relevant segment 16 is able to be individually replaced. To this end, firstly the cover plate 30 is separated from the basic body 20 and then the basic body 20 is separated from the carrier 11. If the cover plate 30 cannot be separated from the basic body 20, for example, on account of heavy contamination or resinification, a screw can be screwed into the threaded bore 33 and, as a result, the cover plate 30 can be pressed away from the basic body 20. A new basic body 20 can then be mounted onto the carrier 11 at the free position and a cover plate 30 can be attached. As a result of simple centering by means of the positioning receiving means 23, 35 and the positioning attachments 17, one or several segments 16 can be changed very rapidly. Together with the long service life, which corresponds to between ten and twelve times the service life of a normal steel counter-blade, very few maintenance-related machine stoppages can thus be achieved. As a result of being able to replace individual segments 16, the spare parts costs can be kept low. The small amount of wear of the hard material elements brings about a constant cutting performance of the counter-blade 10 over a long period of time. This leads to constant quality of the chipped material. In addition, as a result of the high cutting performance, lower energy consumption and consequently reduced operating costs are achieved for the shredding unit. This is noticeable, in particular, in mobile usage by reduced fuel consumption, which along with reduced costs also leads to less environmental pollution.

(9) The front region of the support surface 29, which faces the cutting edge 14 and is under particular mechanical stress, is also protected from premature wear by the protective elements 13. As a result of using a plurality of protective elements 13 arranged in rows next to one another and as a result of the lateral offset in relation to the hard material elements 12 arranged in front thereof, the risk of breakage is reduced here too and a breakage is prevented from spreading further.

(10) FIG. 2 shows a perspective front view of a basic body 20 of the counter-blade 14 with a cutting edge portion 18.

(11) The basic body 20 is produced from a relatively soft, tough steel, for example, from 42CrMo4. In the front region it forms a supporting part 25, on which the hard material elements 12 and the protective elements 13 are soldered. A recess 26, into which the cuboid hard material elements 12 are admitted, is formed toward a front end face 21.2 in the supporting part 25. The front sides of the hard material elements 12, in this case, end with the front end face 21.2 of the basic body and, proceeding from the cutting edge portion 18, form a cutting surface 27. The top surface of the hard material elements 12 ends flush with the top surface of the protective elements 13 which join to the hard material elements 12. The top surface of the protective elements 13 forms a portion of the support surface 29. The protective elements 13 are arranged flush between the hard material elements 12 and the web 28. The web 28, in this case, serves for positioning and mounting the protective elements 13, in particular, during the soldering process during production.

(12) A support plane 21.1, which is placed in a recessed manner compared to the support of the protective elements 13, is provided following the web 28. Proceeding from the support plane 21.1, the basic body 20 is penetrated by three fastening receiving means 22, which are realized as counter bores and are arranged offset, and two threaded receiving means 24.

(13) The basic body 20 is delimited at the side by two side faces 21.3 which extend in a plane-parallel manner and on which the basic bodies 20 are located next to one another in their arrangement on the carrier 11.

(14) At the rear, the basic body 20 ends in a rear end-face stop face 21.4, in the center of which the positioning receiving means 23 is preferably recessed as a wedge-shaped recess.

(15) The basic body 20 consequently forms the basis for a segment 16 of the counter-blade 10. The basic body 20 can be mounted simply and securely on the carrier 11 by means of the fastening receiving means 22 with the aid of screws. As a result of the countersinking applied on the fastening receiving means 22, the screws can be arranged in a recessed manner such that they do not protrude beyond the support plane 21.1. A cover plate 30 shown in FIG. 1 can thus be placed onto the support plane 21.1 of the basic body 20 and tightened at the threaded receiving means 24.

(16) The soft steel used maintains its characteristics during the process of soldering the hard material elements 12 and the protective elements 13.

(17) FIG. 3 shows the representation according to FIG. 2 as an exploded drawing with a cover plate 30. The cover plate 30, in this case, is arranged above the basic body 20 described in FIG. 2. Proceeding from its top surface, it is penetrated by two countersunk bores 32, with which two mounting screws 34 are associated. In addition, the threaded bore 33 is guided through the cover plate.

(18) The dimensions of the cover plate 30 are chosen so as to match the dimensions of the support surface 21.1 of the basic body 20. The bores 32 are arranged in such a manner that, with the cover plate 30 placed in position, they are aligned with the threaded receiving means 24 of the basic body 20. The mounting screws 34 can thus be guided through the bores 32 and screwed into the threaded receiving means 24. As a result, the cover plate 30 is fixedly joined to the basic body 20.

(19) In the mounted state, the screw heads of the mounting screws 34 are arranged countersunk in the cover plate 30. The top surface of the cover plate 30 consequently forms, with the connecting web 28 and the top surface of the protective elements 13, a continuous, flat support surface 29, along which the material to be cut can be fed to the cutting edge portion 18 and consequently to the cutting edge 14.

(20) The fastening receiving means 22 and the screws inserted therein for mounting the basic body 20 onto the carrier 11 are covered by the cover plate 30 and as a result are protected from wear. The cover plate 30 itself is produced from a steel which is harder when compared with the basic body 20 but is nevertheless tough, for example, from Hardox 400. As a result, the support surface 29 is realized in a continuously wear-protected manner. Should the cover plate 30 nevertheless wear prematurely or become damaged, it can be replaced separately and the high-quality hard metal components can continue to be used.

(21) FIG. 4 shows a top view of a segment 16 of the counter-blade 10 in the assembled state. The cover plate 30 is held in the basic body 20 by the mounting screws 34 which are arranged in a countersunk manner. It ends toward the protective elements 29 on the web 28. The top surface of the segment 16 consequently forms a continuous support surface 29 up to the cutting edge portion 18. On the side of the cover plate 30 remote from the web, the second positioning receiving means 35 is molded in the form of a wedge-shaped recess. This extends congruently with respect to the positioning receiving means 23 of the basic body 20 which is located below it. The segment 16 can consequently be aligned simply and quickly in a positionally precise manner in relation to the carrier 11 by the positioning receiving means 23, 35 of the basic body 20 and of the cover plate 30 being slid onto a positioning attachment 17 of the carrier 11.

(22) FIG. 5 shows a side view of the segment 16 of the counter-blade 10 shown in FIG. 4 along a line of intersection marked by way of V-V in FIG. 4.

(23) The cover plate 30 is held on the basic body 20 by way of the mounting screw 34. In the transition from the web 28 to the support plane 21.1, the basic body 20 forms a rounding 28.1. The edge of the cover plate 30 shows a first chamfer 31.1 in the region of the rounding 28.1 such that the cover plate 30 is able to be placed flush onto the support plane 21.1 of the basic body 20. As a result of the rounding 28.1, stress peaks are reduced in the region of the transition from the web 28 into the support plane 21.1.

(24) The cover plate 30, the web 28, the protective elements 13 and the hard material elements 12 form a continuous support surface 29 which, in the mounted state, merges in a flush manner into a corresponding surface of the carrier 11. The material to be cut can consequently be fed via the surface of the carrier 11 and the support surface 29 to the cutting edge portion 18 and consequently to the cutting edge 14. A second chamfer 31.2 is provided on the cover plate 30 in the transition from the support surface 29 to the corresponding surface of the carrier 11. The second chamfer prevents, for example, on account of production tolerances or abrasion of the carrier 11, a step being formed between the surface of the carrier and the support surface 29, on which more wear then occurs as a result of the material to be cut being guided over it. As an alternative to the second chamfer 31.2, the edge of the cover plate 30 can also be realized rounded over a radius. A particularly break-resistant edge which withstands very great stresses is obtained as a result of a radius.

(25) A basic body bottom surface 21.5 of the basic body 20 is realized as a flat surface which is arranged in a plane-parallel manner with respect to the support surface 29. The basic body 20 is able to rest thereon along a mounting plane on a corresponding counter surface of the carrier 11.

(26) FIG. 6 shows a second segment 49 of a second counter-blade (not shown) with two cutting edges.

(27) A second basic body 40 is realized as a substantially elongated cuboid. Along two oppositely situated long edges of the cuboid, the second basic body 40 comprises a front recess 46.1 and a rear recess 46.2 into which front hard material elements 41.1 and rear hard material elements 41.2 are inserted. In each case a row of front protective elements 42.1 and rear protective elements 42.2, which are also produced from a hard material, are arranged joining to the hard material elements 41.1, 41.2. In the exemplary embodiment shown, the front and rear hard material elements 41.1, 41.2 and the front and rear protective elements 42.1, 42.2 are produced from hard metal. A second web 45, which is integrally molded onto the second basic body 40, is arranged between the rows of the protective elements 42.1, 42.2. Second fastening receiving means 44 in the form of stepped bores, which penetrate the basic body 40, are provided along the second web 45. The top surfaces of the front and rear hard material elements 41.1, 41.2, of the front and rear protective elements 42,1. 42.2 and of the second web 45, form a flat second support surface 47. The front and rear holding elements 41.1, 41.2 provide a front cutting edge portion 43.1 and a rear cutting edge portion 43.2.

(28) The second basic bodies 40 can be arranged in a row one next to another on a carrier (not shown) and joined to the carrier by way of screws which are guided through the second fastening receiving means. For secure positioning of the second basic bodies 40, positioning attachments or positioning receiving means which engage in corresponding positioning receiving means or positioning attachments of the carrier, can be provided on the bottom surface of the second basic bodies. The bottom surface of the second basic body 40 forms with the top surface of the carrier a mounting plane in which the positioning receiving means and positioning attachments are arranged. The second basic bodies 40 each comprise two short-side end faces 48 which are realized in a flat manner such that the second basic bodies 40 are able to be arranged flush in rows next to one another on the carrier. The front and rear cutting edge portions 43.1, 43.1 of the second segments 49 which are arranged in rows next to one another form a front and a rear cutting edge of the second counter-blade.

(29) In operation, cutters are moved past each of the two cutting edges. Material to be cut which is introduced into the region of the cutting edges is thus shredded between the cutting edges and the cutters moving past.

(30) In the realization variant too, the inserted small hard material elements 41.1, 41.2 and protective elements 42.1, 42.2 result in a long service life of the second counter-blade. Breakages in one of the hard metal components are not passed onto the next hard metal component. When required, individual second segments 49 can be replaced quickly. In this case, the positioning receiving means and positioning attachments mounted in the mounting plane between the bottom surface of the second basic body 40 and the carrier enable quick and precise positioning of the replacement segments.

(31) In an alternative embodiment (not shown) of the representations shown in FIGS. 1 to 5, the cover plates 30 can be arranged offset to the side in such a manner with respect to the basic bodies 20 that the abutment edges between the basic bodies 20 arranged in a row next to one another, formed along the side faces 21.3, are covered by the cover plates 30. A cover plate 30 is then screwed at one of its bores 32 with a first base plate 30 and at its second bore 32 with an adjacent second base plate 30. In each case, the outermost of the base plates 30 arranged on a counter-blade 10 are realized in a shortened or lengthened form, for example, with half a width or one and a half widths of a basic body 20 measured in the direction of the longitudinal extension of the counter-blade. Advantageous in this connection is that a continuous gap, into which waste material can be pressed, is not formed up to the carrier 11 between the cover plates 30 and the basic bodies 20.