counter blade

Abstract

A counter blade (1) for a cutting unit, particularly in a mobile or stationary chipper, comprises a base body (2), a clamping strip (3) positively attached to the base body (2), and at least one cutting insert (4) with a respective cutting edge (5). The at least one cutting insert (4) is clamped between the base body (2) and the clamping strip (3). A tongue-and-groove connection (11) is formed between the base body (2) and the clamping strip (3) to create a positive fit perpendicular to the at least one cutting edge (5).

Description

[0001] The invention relates to a counter-blade for a cutting unit, for example in a mobile forage harvester.

[0002] Cutting units in forage harvesters are used, for example, for chopping grass, corn, and whole-crop silage (GSP). For precise adjustment of the cutting gap between the cutting blades and the counterblade, good dimensional accuracy of the counterblade is important. Furthermore, detachment or breakage of parts of the counterblade should be avoided, as this can lead to significant damage to the cutting unit or downstream machine components. Loosening parts also pose a significant risk of injury to the machine operator.

[0003] In conventional carbide counterblades, the cutting edges are brazed to a base body. The resulting heat input can lead to component distortion, thus compromising the dimensional accuracy of the counterblade. Furthermore, the cutting edges are difficult to exchange or replace, which reduces the service life of the counterblade.

[0004] AT 002 761 U proposes a counter-blade in which a cutting insert is held between a base body and a retaining plate. The retaining plate is connected to the base body via screws in a force-locking manner. Due to the forces acting on the cutting insert perpendicular to the cutting edge during cutting, the retaining plate can be lifted or levered out from the base body, particularly if the force-locking connection is loosened, which can lead to the retaining plate and / or the cutting insert breaking out.

[0005] It is the object of the present invention to improve a counter-blade, in particular with regard to its dimensional accuracy and service life.

[0006] This object is achieved by a counter-blade having the features specified in claim 1. The counter-blade has a base body, a clamping bar fastened to the base body in a force-fitting manner, and at least one cutting insert with a respective cutting edge. The at least one cutting insert is clamped between the base body and the clamping bar. A groove-and-tenon connection is formed between the base body and the clamping bar to effect a positive connection perpendicular to the at least one cutting edge. The positive connection counteracts the lifting or levering out of the clamping bar due to forces acting transversely to the cutting edge. This improves the stability and service life of the counter-blade.

[0007] The positive locking action is particularly perpendicular to the cutting edge and perpendicular to the direction of the frictional connection between the base body and the clamping bar. The positive locking action acts directly between the clamping bar and the base body and is therefore independent of additional fastening elements. In particular, the positive locking action is effective even when the frictional connection is loose or even broken.

[0008] At least one cutting insert is clamped between the clamping bar and the base body. The clamping force is achieved by the frictional connection. This allows for easy adjustment. Heat input and thus component distortion during the attachment of the at least one cutting edge are avoided, and dimensional accuracy is improved.

[0009] According to a preferred aspect of the counter-blade, the groove-tenon connection has at least one groove formed in the surface of the base body facing the clamping bar, into which a corresponding tenon formed on the surface of the clamping bar facing the base body engages. The formation of the tenon on the clamping bar has the advantage that the clamping bar is reinforced in the area of ​​the groove-tenon connection and is therefore particularly stable. In principle, it is also possible to swap the position of the tenon and groove on the base body and the clamping bar.

[0010] According to a preferred aspect of the counter-blade, the groove-tenon connection creates a positive fit parallel to the cutting edge. This precisely defines the positioning of the clamping bar and thus of the cutting inserts in the longitudinal direction of the cutting edge. The positive fit also counteracts forces along the cutting edge. The positive fit along the cutting edge can be formed, for example, by corresponding end-face stop surfaces in the at least one groove. Preferably, the at least one groove and the at least one corresponding tenon do not extend over the entire length of the clamping bar or separate clamping bar segments.

[0011] According to a preferred aspect of the counter-blade, the base body and the clamping bar are spaced apart in the direction of frictional engagement by a gap. This reduces the contact surfaces between the base body and the clamping bar, so that manufacturing tolerances have less of an impact on the dimensional accuracy of the counter-blade. The gap thus acts as a tolerance compensation. Direct contact surfaces between the base body and the clamping bar are limited to the groove-tenon connection. Particularly preferably, the base body and the clamping bar only contact one another indirectly in the direction of frictional engagement via the at least one cutting insert clamped therebetween.

[0012] A further advantage of the gap is that the clamping forces acting on the at least one cutting insert are increased. The at least one cutting insert is held particularly securely.

[0013] A further advantage of the gap is that wear or regrinding of at least one cutting insert does not affect the fit of the counterblade. The gap also acts as tolerance compensation in this regard.

[0014] According to a preferred aspect of the counter-blade, side surfaces of the at least one cutting insert that bear against the clamping bar or the base body are parallel to one another. The parallel side surfaces improve the fit. Furthermore, the clamping force is applied evenly across the entire side surfaces, resulting in a particularly stable attachment of the at least one cutting insert. Warping or tilting of the cutting insert due to the clamping force is avoided. A further advantage of the parallel side surfaces is that the cutting insert can be rotated if necessary, for example, when worn.

[0015] According to a preferred aspect of the counter-blade, fastening means, in particular screws, for the force-locking connection of the base body and the clamping bar engage via through-holes in the base body in fastening receptacles, for example internal threads, of the clamping bar, wherein the fastening receptacles are closed towards the surface of the clamping bar facing away from the base body. The fastening receptacles, in particular the internal threads, are designed as blind holes. The connection, in particular the screwing, of the base body and the clamping bar takes place exclusively from the surface of the base body facing away from the cutting edge. This reliably prevents any impairment of the fastening means during cutting operation. In particular, wear of the fastening means, for example washing out of the screws, is avoided.In particular, neither cutting material nor other contaminants can penetrate through fastening receptacles that are open to the surface and thus promote wear.

[0016] Particularly preferably, the surface of the clamping bar facing away from the base body is flat, especially smooth. This reduces the potential for contact surfaces for material to be cut or other contaminants that could lead to wear.

[0017] The fastening means can be designed, in particular, for a releasable, force-locking connection between the clamping bar and the base body. The fastening means can, in particular, be screws. This facilitates the replacement of the clamping bar and / or the at least one cutting insert. The fastening means, in particular the screws, can be secured against loosening, for example, by gluing. The force-locking connection can then be released, for example, by drilling out the fastening means.

[0018] According to a preferred aspect of the counterblade, it has two cutting inserts arranged parallel to opposite longitudinal edges of the clamping bar. When one of the cutting inserts becomes worn, the counterblade can be rotated. This extends the service life of the counterblade.

[0019] Particularly preferably, the counter-blade has a mirror-symmetrical structure with respect to a center plane aligned parallel to the direction of frictional engagement, at least in the longitudinal regions where the cutting edge extends. The counter-blade can be easily inserted in a rotated position, without, for example, the need to readjust the cutting gap.

[0020] According to a preferred aspect of the counterblade, the clamping bar comprises several separate clamping bar segments arranged along the cutting edge. Dividing the clamping bar into separate segments allows for their separate replacement and maintenance. This reduces material consumption and maintenance costs.

[0021] According to a preferred aspect of the counter-blade, the at least one cutting insert has separate cutting insert segments corresponding to the clamping bar segments. In particular, the clamping bar segments and the cutting insert segments each have corresponding lengths in the direction of the cutting edge. The cutting insert segments can be easily and independently replaced by simply removing the respective clamping bar segment. This reduces maintenance costs and effort.

[0022] According to a preferred aspect of the counter-blade, each clamping bar segment is positively connected to the base body via a respective groove-tenon connection. The advantages of the groove-tenon connection are present for the respective clamping bar segments. Levering of the respective clamping bar segments is reliably prevented. In particular, the respective groove-tenon connections also ensure a positive connection in the direction of the cutting edge, thus ensuring precise positioning of the clamping bar segments along the cutting edge.

[0023] According to a preferred aspect of the counter-blade, the clamping bar is made of through-hardened steel, preferably from rolled through-hardened sheet steel. This simplifies the production of the clamping bar, particularly using machining processes. The clamping bar can be manufactured with high dimensional accuracy. Furthermore, manufacturing and material costs are reduced. Through-hardened steel also has the advantage of a good compromise between the material's hardness and brittleness, so the use of this material has proven particularly advantageous. Particularly suitable through-hardened steels are sold, for example, under the trade names Hardox or Raex.

[0024] The at least one cutting insert can preferably be made of hard metal. The cutting insert has a high degree of hardness. The requirement for hard metal can advantageously be reduced by manufacturing only the at least one cutting insert from hard metal. This reduces material costs and simplifies production.

[0025] According to a preferred aspect of the counter-blade, the base body has at least one mounting section for mounting the counter-blade on an anvil of the cutting unit, wherein the base body has a thickness in the region of the mounting section in the frictional connection direction that is equal to or less than the thickness of the base body in the regions adjacent to the mounting section. Corresponding mounting sections are preferably present at the respective front ends of the base body. The low thickness of the mounting section has the advantage that the post-processing of the base body, in particular with machining processes, is simplified. For example, accessibility for introducing one or more grooves for the tongue and groove connection is improved. In particular, the base body can be post-processed without any radii being created between the mounting section and the sections in which the clamping bar is attached, which improves the accuracy of fit.

[0026] According to a preferred aspect of the counterblade, it has a compensating plate attached to the respective mounting section for equalizing the thickness of the counterblade in the area of ​​the mounting section and in areas of the clamping bar. The counterblade has a substantially consistent thickness, except for projections of the cutting inserts for forming the cutting edge. This simplifies positioning in the cutting unit. Furthermore, the counterblade can be compatible with existing counterblades in cutting units that have a predetermined thickness. Existing counterblades can be replaced. The counterblade is easily retrofittable.

[0027] The respective compensating plates can be attached to the at least one mounting section in a force-fitting manner, in particular by means of screws. This, in turn, avoids heat input. Advantageously, the attachment, in particular the screwing, takes place from the side of the base body facing away from the cutting edge. For example, compensating plate receptacles for receiving a fastening means, in particular the screws, can be designed as blind holes, so that they are closed off towards the surface of the compensating plate facing away from the base body.

[0028] The invention has been described above with reference to a counter blade which has a groove - pin connection formed between the base body and the clamping strip to effect a form - fit perpendicular to the at least one cutting edge. However, providing a groove - pin connection between the base body and the clamping strip is not essential or required for all embodiments of the invention. Also, other aspects described herein can represent an independent invention regardless of the provision of a groove - pin connection, in particular the use of a clamping strip made of hardened steel, one or more fastening receptacles formed as blind holes in the clamping strip, a spacing of the base body and the clamping strip in the force - closing direction by a gap and / or parallel - running side surfaces of the at least one cutting insert which bear against the base body or against the clamping strip.According to the invention, at least one counter-blade for a cutting unit is therefore also provided, comprising a base body, a clamping bar fastened to the base body in a force-fitting manner, and at least one cutting insert with a respective cutting edge, wherein the at least one cutting insert is held clamped between the base body and the clamping bar, wherein the counter-blade has one or more of the following features:. - the base body and the clamping bar are spaced apart in the direction of frictional connection by a gap; and / or - Side surfaces of the at least one cutting insert which bear against the clamping bar or the base body are parallel to each other; and / or - the clamping bar is made of a through-hardened steel, in particular of a rolled through-hardened steel sheet; and / or - Fastening means for the force-locking connection of the base body and the clamping bar engage in fastening receptacles of the clamping bar via through openings in the base body, the fastening receptacles being closed towards the surface of the clamping bar facing away from the base body, the fastening receptacles being designed in particular as blind holes.

[0029] Further features, advantages, and details of the invention will become apparent from the following description of an embodiment with reference to the figures. They show: Fig. 1 a perspective exploded view of a counter blade with a base body and a clamping bar, between which two cutting inserts are clamped, Fig. 2 a side view of the counter blade, Fig. 3 a top view of the counter blade, Fig. 4 a longitudinal section through the counter cutting edge along a cutting edge IV-IV in Fig. 3, Fig. 5 a cross section through the counter cutting edge along a cutting edge VV in Fig. 3 and Fig. 6 a cross section through the counter cutting edge along a cutting edge VI-VI in Fig. 3.

[0030] In the Fig. 1 to 6, an exemplary embodiment of a counter-blade 1 is shown. The counter-blade has a base body 2, a clamping bar 3, and two cutting inserts 4. The clamping bar 3 is connected to the base body 2 in a force-locking direction K (cf. Fig. 5) are non-positively secured. The cutting inserts 4 are clamped between the base body 2 and the clamping bar 3, with the clamping force resulting from the non-positive attachment of the clamping bar 3 to the base body 2.

[0031] The base body 2 has a length L in its longitudinal direction, which can be, for example, approximately 87.3 cm. The cutting inserts 4 extend over a length l along the longitudinal direction and form a cutting edge 5 that slightly protrudes beyond the base body 2 and the clamping bar 3 in the force-locking direction K and the width direction of the base body 2. The length l of the cutting edge 5 can be, for example, approximately 77.6 cm.

[0032] The two cutting inserts 4 are arranged parallel on opposite longitudinal sides of the clamping bar 3, so that corresponding cutting edges 5 are formed along the respective longitudinal sides 2. If one of the cutting edges 5 becomes worn, the counter-blade 1 can be reused by being mounted in the cutting unit in a rotated position. For this purpose, the counter-blade 1 is preferably constructed mirror-symmetrically with respect to a mirror plane spanned by the force-locking direction K and the central longitudinal axis, particularly in longitudinal regions over which the cutting edge 5 extends.

[0033] At the front ends of the base body 2, mounting sections 6 are formed which extend in the longitudinal direction beyond the cutting inserts 4 and via which the counter blade 1 can be mounted on an anvil of a cutting unit.

[0034] The cutting inserts 4 are divided into separate cutting insert segments 7 in the direction of the cutting edges 5. In the illustrated embodiment, there are three cutting insert segments 7 per cutting insert 4. Accordingly, the clamping bar 3 is divided into several separate clamping bar segments 8 in the direction of the cutting edges 5. The lengths of the clamping bar segments 8 correspond to the length of the respective cutting insert segments 7, so that the cutting insert segments 7 and / or the clamping bar segments 8 can be replaced independently, for example, when they are worn.

[0035] On its surface facing the clamping bar 3, the base body 2 has grooves 9. The clamping bar 3 has corresponding tenons 10 on its surface facing the base body 2, which engage in the grooves 9. Each clamping bar segment 8 has a tenon 10 that engages in a corresponding groove 9 in the base body 2. This creates a groove-tenon connection 11, via which the clamping bar 3, in particular its respective clamping bar segments 8, are positively connected to the base body 2. The positive connection is perpendicular to the cutting edge 5 and in particular perpendicular to the force connection direction K, so that levering out of the clamping bar 3 due to transverse forces on the cutting edge 5 during operation of the cutting unit is prevented.

[0036] The groove-tenon connection 11, in particular the grooves 9 and the tenons 10, are formed symmetrically perpendicular to the longitudinal extension of the cutting edge 5, so that the positive locking acts equally with respect to the two cutting edges 5.

[0037] The grooves 9 and the tenons 10 do not extend over the entire length of the respective clamping bar segments 8. This creates end-face stop surfaces 12, so that the groove-tenon connection 11 also creates a positive connection in the direction of the cutting edge. The clamping bar segments 8 can be precisely positioned along the cutting edge. This further improves the dimensional accuracy and stability of the counter-blade 1.

[0038] The force-locking connection between the base body 2 and the clamping bar 3 is achieved by fastening means in the form of screws 13. In the exemplary embodiment shown, for example, there are four screws 13 per clamping bar segment 8. The screws 13 are guided through a through-opening 14 in the base body 2 and engage in fastening receptacles 15 in the clamping bar 3. The fastening receptacles 15 are designed as internal threads for the engagement of the screws 13. The fastening receptacles 15 are closed towards the surface 16 of the clamping bar 3 facing away from the base body 2. The fastening receptacles 15 are introduced as blind holes in the clamping bar 3 or the respective clamping bar segments 8. Due to the design of the fastening receptacles 15, which are closed towards the surface 16, the force-locking fastening is protected against wear during operation of the cutting unit.In particular, this prevents the screws 13 from being washed out, as is the case, for example, with continuous fastening receptacles 15 due to the penetration of foreign matter, such as dust. This reliably prevents the clamping bar from becoming loose.

[0039] The surface 16 of the clamping bar 3 facing away from the base body 2 is flat, particularly smooth. This prevents foreign matter, such as dust, from penetrating the clamping bar.

[0040] As particularly in Fig. 5, the base body 2 has protruding bevels 17 in the areas facing the cutting inserts 4, against which the side surfaces of the cutting inserts 4 rest. In the area of ​​the cutting edge 5 of the opposite end of the cutting inserts 4, the base body 2 forms cutting insert contact surfaces 18. Adjacent to the cutting insert contact surfaces 18, pockets 19 are formed, which serve to compensate for tolerances.

[0041] In the force-locking direction K, the base body 2 is spaced from the clamping bar 3 by a gap 20. In the force-locking direction K, the clamping bar 3 rests only indirectly on the base body 2 via the cutting inserts 4. This ensures that the entire clamping force caused by the force-locking action acts on the cutting inserts 4. The cutting inserts 4 are held particularly stably.

[0042] The gap 20 also prevents the clamping bar 3 from contacting the base body 2 in the area of ​​the facing surfaces. This allows manufacturing tolerances to be compensated.

[0043] Thanks to the gap 20, the cutting inserts 4 can also be reground without affecting the fit. The gap 20 also acts as a tolerance compensation in this regard. The cutting inserts 4 can be easily reground and have a long service life.

[0044] The cutting inserts 4 have side surfaces 21, 22 that rest against the base body 2 and the clamping bar 3, respectively. The side surfaces 21, 22 are parallel to each other. This improves the fit and ensures a uniform application of the clamping force. This prevents the cutting inserts 4 from tilting or warping due to the clamping force.

[0045] In the assembly sections 6, the base body 2 has a thickness d in the frictional connection direction K that is smaller than the thickness of the base body 2 in areas adjacent to the assembly sections 6. This simplifies the machining of the base body, in particular with machining processes, for example when manufacturing the protruding bevels 17, the cutting insert contact surfaces 18 and the pockets 19 and / or their grooves 9. Radii between the assembly sections 6 and adjacent areas, which would be unavoidable if the assembly sections 6 protruded in the frictional connection direction K and could negatively influence the fit, are avoided.

[0046] The mounting sections 6 have mounting through-openings 23 through which mounting means, for example screws, for fastening the counterblade 1 to the anvil of the cutting unit can be guided. Compensating plates 24 are fastened to the respective mounting section 6. The compensating plates 24 adjust the thickness D of the counterblade 1 in areas of the mounting sections 6 and in areas of the clamping bar 3. The counterblade 1 has a substantially constant thickness D over its length. This makes it possible, in particular, to use existing mounting means to fasten the counterblade 1 to the anvil. In this respect, the compensating plates 24 act as a mounting adapter. The counterblade 1 can be easily retrofitted to existing cutting units.

[0047] The compensating plates 24 are secured by screws 25, which engage in respective compensating plate receptacles 27 with corresponding internal threads. As explained above with regard to the fastening receptacles 15 of the clamping bar 3, the compensating plate receptacles 27 are designed as blind holes, so that the screws 25 are protected against wear.

[0048] The cutting inserts 4 are made of hard metal, which ensures particularly good cutting performance. The clamping bar 3 is made of through-hardened steel, in particular of rolled through-hardened sheet steel. Suitable through-hardened steels are sold, for example, under the trade names Hardox or Raex. Through-hardened steel has the advantage that it can be machined, for example, for cutting the fastening receptacles 15. Furthermore, through-hardened steel offers a good compromise between strength and brittleness, thus further preventing the risk of the clamping bar 3 breaking out. In addition, the use of hard metal is limited to the cutting inserts 4, which reduces material costs. The base body 2 can be made of steel, for example, 42CrMo4 steel. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] AT 002 761 U

[0004]

Claims

[1] Counter-blade for a cutting unit, in particular in a mobile or stationary shredder, comprising - a base body (2), - a clamping bar (3) firmly attached to the base body (2) and - at least one cutting insert (4) with a respective cutting edge (5), wherein the at least one cutting insert (4) is clamped between the base body (2) and the clamping bar (3), characterized by a groove-tenon connection (11) formed between the base body (2) and the clamping bar (3) for effecting a positive connection perpendicular to the at least one cutting edge (5). [2] Counter-blade according to claim 1, characterized by that the groove-tenon connection (11) has at least one groove (9) introduced into the surface of the base body (2) facing the clamping bar (3), into which a corresponding tenon (10) formed on the surface of the clamping bar (3) facing the base body (2) engages. [3] Counter-blade according to one of the preceding claims, characterized by that the groove-tenon connection (11) creates a positive connection parallel to the cutting edge (5). [4] Counter-blade according to one of the preceding claims, characterized by that the base body (2) and the clamping bar (3) are spaced apart in the direction of frictional engagement (K) by a gap (20). [5] Counter-blade according to one of the preceding claims, characterized by that side surfaces (21, 22) of the at least one cutting insert (4), which bear against the clamping bar (3) or the base body (2), are parallel to one another. [6] Counter-blade according to one of the preceding claims, characterized bythat fastening means (13) for the force-locking connection of the base body (2) and the clamping bar (3) engage via through openings (14) in the base body (2) in fastening receptacles (15) of the clamping bar (3), wherein the fastening receptacles (15) are closed towards the surface (16) of the clamping bar (2) facing away from the base body (2). [7] Counter-blade according to one of the preceding claims, characterized by two cutting inserts (4) arranged parallel on opposite longitudinal edges of the clamping bar (3). [8] Counter-blade according to one of the preceding claims, characterized by that the clamping bar (3) has several separate clamping bar segments (8) arranged along the cutting edge (5). [9] Counter-blade according to claim 8, characterized by that the at least one cutting insert (4) has separate cutting insert segments (7) corresponding to the clamping bar segments. [10] Counter-blade according to claim 8 or 9, characterized bythat each clamping bar segment (8) is positively connected to the base body (2) via a respective groove-tenon connection (11). [11] Counter-blade according to one of the preceding claims, characterized by that the clamping bar (3) is made of hardened steel. [12] Counter-blade according to one of the preceding claims, characterized by that the base body (2) has at least one mounting section (6) for mounting the counter-blade (1) on an anvil of the cutting unit, wherein the base body (2) in the region of the mounting section (6) in the frictional connection direction (K) has a thickness (d) which is equal to or smaller than the thickness of the base body (2) in regions adjacent to the mounting section (6). [13] Counter-blade according to claim 12, characterized bya compensating plate (24) fastened to the respective mounting section (6) for adjusting thicknesses (D) of the counter-blade (1) in the area of ​​the mounting section (6) and in areas of the clamping bar (3).

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