Cutting tool

Abstract

Cutting tool (10) for an agricultural or forestry cutting unit with a carrier (11) having a knife longitudinal guide (14), wherein the carrier (11) has at least one cutting projection (20, 50) having a cutting support (21), wherein a cutting surface (34) is arranged in the area of ​​the cutting support (21) which is designed and arranged such that a cutting knife is adjustable along a cutting plane relative to the cutting surface (34), characterized in that a cutting element (30) made of a more wear-resistant material than the material of the cutting support (21) is attached to the cutting support (21), and that the cutting element (30) has at least one cutting edge (31.1, 31.2) which runs along or substantially along a cutting edge side of the cutting projection (20, 50) and which transitions into the cutting surface (34).

Description

[0001] The invention relates to a cutting tool for an agricultural or forestry cutting unit with a carrier having a knife longitudinal guide, wherein the carrier has at least one cutting attachment with a cutting blade carrier, wherein a cutting surface is arranged in the area of ​​the cutting blade carrier, which is designed and arranged in such a way that a cutting blade is adjustable along a cutting plane relative to the cutting surface.

[0002] Such cutting tools can be, for example, cutting fingers of a cutting unit, in particular a knife mower, a double knife mower, a double knife cutting unit, a sickle bar mower, a hedge cutter or a branch cutter.

[0003] The cutting tool serves two purposes: firstly, to guide a moving blade, and secondly, to act as a counter blade for the blade, typically used to cut plants such as grasses, grains, and hedges. Contact with soil, stones, etc., causes wear on the cutting edges of the cutting tools, reducing the machine's performance and the quality of the work.

[0004] A cutting arrangement with a cutting tool is known, for example, from EP 3 744 164 A1.

[0005] The object of the invention is to provide a cutting tool of the type mentioned above that enables permanently improved work performance.

[0006] This problem is solved by attaching a cutting element to the cutting carrier, consisting of a more wear-resistant material than the material of the cutting carrier, and by having at least one cutting edge that runs along or substantially along a cutting edge side of the cutting attachment and that merges into the cutting surface.

[0007] At least one cutting edge of the cutting tool is thus formed by a single component, namely the cutting element, which exhibits high wear resistance. This ensures that the cutting edge remains dimensionally stable during operation and guarantees good cutting performance. Advantageously, the cutting surface on which the blade slides is also formed by the cutting element and therefore also exhibits good wear resistance. In particular, this results in minimal wear on the contact area between the blade and the cutting surface. This prevents stalks from being drawn into this area, which can be a problem, especially in damp weather conditions. Thus, cutting performance can be maintained, leading to improved efficiency compared to conventional solutions.The cutting tool holder can be made from a comparatively tougher material than the cutting element, ensuring that the bending stresses acting on the cutting tool during operation are reliably absorbed. For example, the cutting tool holder can be made of steel, while the cutting element can be made of a hard material such as cemented carbide (tungsten carbide) or ceramic. It is also conceivable that the steel material of the cutting tool holder is surface-hardened and / or boronized, at least in certain areas. Advantageously, the cutting element consists of a molded body, particularly a sintered component, which is bonded to the cutting tool holder.

[0008] To reduce the number of parts, the cutting element can be designed to have a cutting edge on each of its opposite longitudinal sides, with each cutting edge running along one side of the cutting edge of the cutting attachment. Alternatively, it is also conceivable that the cutting element carrier has a cutting element with a single cutting edge on each of its opposite longitudinal sides. This reduces the material required for the relatively expensive hard material.

[0009] Within the scope of the invention, it is possible to use several cutting elements arranged in series, each forming a cutting edge, with the individual cutting edges of the cutting elements then forming a common cutting edge. This reduces the risk of breakage for the cutting element, particularly when strong bending stresses are expected.

[0010] Within the scope of the invention, it can also be provided that the cutting edges run parallel to each other or converge towards the free end of the cutting element. Parallel cutting edges typically work in conjunction with knives that have cutting edges angled to the cutting edges of the cutting element. If converging cutting edges angled to each other are used, they can preferably also work in conjunction with cutting edges of knives that run at an angle to them, in order to achieve a particularly effective cut, especially a shear cut.

[0011] A particularly preferred embodiment of the invention is such that the cutting element is formed by a hard material component, in particular a hard metal component (tungsten carbide component). It has been shown that such hard material components can effectively withstand the prevailing load forces, especially in combine harvester headers.

[0012] One conceivable alternative invention is such that the cutting element has a front surface facing the free end of the cutting edge, and that this front surface is at least partially covered by a body edge of the cutting edge transverse to the longitudinal extent of the cutting edge. This protects the front surface of the cutting element, which is particularly susceptible to breakage during machining due to the feed movement of the cutting tool in the feed direction. Consequently, the risk of chamfer fractures in the cutting tool is reduced, especially when the cutting element is made of carbide.

[0013] A cutting tool according to the invention can be configured such that the cutting element has a rear side facing away from the free end of the cutting edge, which faces a side surface of a transition section, wherein the transition section forms a transition between the longitudinal guide of the blade and the cutting edge. This results in a compact design that simultaneously offers good wear protection against the blade sliding on the cutting surface.

[0014] According to one embodiment of the invention, the cutting element may also have a lower, preferably flat, connecting surface by means of which the cutting element is materially bonded to an opposing counter surface of the connecting section of the cutting attachment. In particular, it may be provided that a materially bonded connection, especially a soldered, adhesive, and / or welded joint, is arranged between the counter surface and the connecting surface. This creates a secure and highly resilient connection. In particular, a soldered and / or adhesive joint may preferably be designed to form a somewhat elastic bonding layer, so that impact loads acting on the cutting element are dampened. This reduces the risk of breakage of the cutting element. Preferably, the cutting element is supported over its entire surface, preferably over its entire surface, in the area of ​​its connecting surface.This also reduces the risk of breakage.

[0015] Another possible embodiment of the invention is such that the two converging cutting edges merge into one another in the region of the free end of the cutting attachment by means of a cutting tip of the cutting element. Preferably, the cutting edge is convexly rounded to improve the stability of the cutting element.

[0016] For easier maintenance of the cutting tool, the cutting element can be provided in a replaceable manner with the cutting attachment, preferably by means of at least one fastening element, in particular by means of at least one screw. In case of damage, the cutting element can then be easily replaced. It is also conceivable that the cutting attachment forms a replaceable part of the cutting tool. It can then be replaced together with the cutting element in case of damage.

[0017] A particularly effective cutting tool can be created by having the cutting edge have a cover section that is spaced apart from the cutting edge carrier, with a knife gap being formed between the cutting edge carrier and the cover section, and by having the cutting element, which is carried by the cutting edge carrier, limit the knife gap at least partially by means of its cutting surface.

[0018] It can also be provided that the cover section in the area of ​​the knife gap carries at least one further cutting element, which is designed as a separate component and connected to the cover section, preferably in a replaceable manner, and it is particularly preferred that the cutting element and the further cutting element are designed as identical parts. Thus, the cutting tool provides at least one cutting edge on each of the two opposite sides of the knife gap. This allows a double-cutting function to be implemented with appropriately designed knives.

[0019] If it is provided that the / a cover section of the cutting attachment is spaced apart from the cutting support by means of a connecting element arranged at the end of the cutting attachment, such that the knife gap is formed between the cover section and the cutting support, then the connecting element protects the cutting element from any stress acting on the front.

[0020] According to a variant of the invention, the at least one cutting edge with the attached cutting element can also form a first component, which is connected to a second component, preferably having the longitudinal guide for the blade, preferably in a replaceable or non-replaceable manner, for example by welding. Thus, these two components can be equipped with different properties. For example, the component forming the blade guide is specifically designed to withstand the frictional wear acting upon it. With a replaceable connection between the two components, maintenance effort is again reduced in the event of damage.

[0021] The object of the invention is also achieved with a cutter bar for a combine harvester header, a knife mower, a double knife mower, a double knife cutting unit, a sickle bar mower, a hedge cutter or a branch cutter, with at least one cutting tool according to one of claims 1 to 14.

[0022] The invention will be explained in more detail below with reference to exemplary embodiments illustrated in the drawings. The drawings show: Fig. 1. A cutting tool in perspective view from below. Fig. 2 the cutting tool according to Fig. 1 in perspective view from above, Fig. 3 the cutting tool according to the Fig. 1 and Fig. 2 in top view, Fig. 4 the cutting tool according to the Fig. 1-3 in side view, Fig. 5 the cutting tool according to the Fig. 1-4 along the in Fig. 3 section lines marked with VV, Fig. 6 Another design variant of a cutting tool in perspective view, Fig. 7 the cutting tool according to Fig. 6 in perspective view from above, Fig. 8. Make a horizontal cut through the cutting tool according to the Fig. 6 and Fig. 7, Fig. 9. Make a cut through the cutting tool along the in Fig. 8 with section line marked IX-IX, Fig. 10 another design variant of a cutting tool along the in Fig. 11 section marked with XX, Fig. 11 the cutting tool according to Fig. 10 in side view and Fig. 12 the cutting tool according to the length of the in Fig. 10 with section line marked XII-XII.

[0023] Fig. Figure 1 shows a cutting tool 10 with a carrier 11. The carrier 11 has a knife guide 14, which can be formed integrally with the carrier 11. The knife guide 14 can, as Fig. 2 shows that it is such that it has one or more guide pieces 14.1, 14.2, 14.3.

[0024] A guide element of a knife arrangement (not shown) can be adjusted on or attached to at least one guide piece 14.1, 14.2, 14.3. The adjustment movement of the knife arrangement is carried out according to Fig. 3 from top to bottom and vice versa in an oscillating motion. To guide the knife assembly, the knife guide 14 can further be configured such that it has two spaced-apart lateral boundary surfaces 15.1, 16.1, which also extend in the guidance direction. These prevent the knife assembly from deflecting transversely to the longitudinal guidance direction of the knife guide 14.

[0025] It is possible that the boundary surface 15.1 is formed by a wall element 15, which is integrally formed with the beam 11. It is also conceivable that the boundary surface 16.1, which is at a distance from the boundary surface 15.1, is formed integrally by a transition section 16 of the beam 11.

[0026] Advantageously, the guide pieces 14.1, 14.2, 14.3 are formed by webs 12.1, 12.2, 12.3, which are preferably spaced apart from each other in the width direction of the cutting tool 10.

[0027] The Fig. Figures 1-3 illustrate that at least one opening 17 is present in the area of ​​the knife guide 14, preferably formed between two adjacent webs 12.1, 12.2, 12.3. Any organic material that may have entered the area of ​​the knife guide 14 can be conveyed out through these openings 17. Fig. 3 the cutting tool 10 has a width B and according to Fig. 4 perpendicular to this a length L. The knife guide 14 extends with its guide direction in the direction of the width B.

[0028] Advantageously, one or more mounting bosses 13 are attached to the carrier 11, preferably in one piece, and are spaced apart from each other in the width direction. The mounting bosses 13 can have mounting receptacles 13.1, for example, bores. The cutting tool 10 can be attached to a cutting unit (not shown) by means of the at least one mounting boss 13.

[0029] Like the characters, especially the Fig. 3 and Fig. As shown in Figure 4, the cutting tool 10 has at least one cutting projection 20, 50. Advantageously, the cutting projection 20, 50 is integrally formed on the carrier 11. Preferably, the at least one cutting projection 20, 50 adjoins the transition section 16 integrally. The at least one cutting projection 20, 50 extends in the direction of the length L of the cutting tool 10.

[0030] The cutting attachment 20, 50 has a cutting support 21 which connects to the transition section 16. As mentioned above, the cutting support 21 can be connected to the transition section 16 as a single unit. However, it is also conceivable that the cutting attachment 20, 50 is interchangeably connected to the support 11.

[0031] In the present embodiment, three cutting projections 20, 50 are used, which are spaced apart from each other in the direction of width B. Preferably, the two outer cutting projections 20 project beyond the central cutting projection 50, which is arranged between the two outer cutting projections 20, in the direction of length L of the cutting tool 10. Alternatively, the central cutting projection 50 may project beyond the outer cutting projections 20, or all cutting projections may project by the same amount.

[0032] It is possible that at least one cutting edge 20 forms or has a connecting element 22 at its longitudinal end facing away from the support 11. A cover section 23 adjoins this connecting element 22. Preferably, as shown in the drawings, the cutting edge support 21, the connecting element 22, and the cover section 23 are formed in one piece.

[0033] A knife gap 24 is formed between the cutting carrier 21 and the cover section 23. A knife of the knife assembly can be linearly adjusted within this knife gap 24. As shown Fig. 4 The knife gap 24 has an insertion section 25 facing the carrier 11. Through this insertion section 25 the knife is led out and coupled to the guide section of the knife arrangement, which is guided in the knife guide 14.

[0034] The height of the knife gap is in Fig. 4 marked SH. Preferably, the height of the knife gap 24 is selected in the range between 2 mm and 10 mm. Preferably, the height SH is selected in the range between 3 mm and 6 mm.

[0035] As the drawings illustrate, the cutting element carrier(s) carry 21 cutting elements 30. The shape of the cutting elements 30 can be described by the Fig. 3 and Fig. 4. As these illustrations show, it is possible that at least one of the cutting elements 30 is designed as a plate-shaped body.

[0036] The cutting element 30 is designed as a separate component connected to the cutting tool holder 21. The cutting element 30 is made of a material that is more wear-resistant than the material of the cutting tool holder 21. In particular, the cutting element 30 can be made of a hard metal (tungsten carbide). It is also conceivable that the cutting element 30 is made of a ceramic element.

[0037] The cutting element 30 can be interchangeably connected to the cutting carrier 21, as shown by the Fig. Figures 3-5 show that for this purpose the cutting element 30 is connected to the cutting element holder 21 by means of a fastening element 40.

[0038] It may be that the cutting element 30 has at least one screw receptacle 37 for this purpose, through which the fastening element 40, designed as a fastening screw, is passed and screwed into a screw receptacle of the cutting carrier 21.

[0039] However, it is also conceivable that the cutting element 30 is not interchangeably connected to the cutting carrier 21, for example, by a material-bonded connection. It is also conceivable that the cutting element 30 is connected to the cutting carrier 21 by means of a soldered or adhesive bond.

[0040] If, as in the present embodiment, a deck section 23 is used, then the deck section 23 may have one or more openings 26 through which the fastening element 40 can be mounted.

[0041] The cutting element(s) 30 exhibit(s) as Fig. Figure 3 shows at least one cutting edge 31.1, 31.2. The cutting edges 31.1, 31.2 preferably extend linearly in the direction of the longitudinal extension of the cutting projections 20, 50.

[0042] Evidentiously Fig. In Figure 3, two cutting edges 31.1, 31.2 of the two outer cutting projections 20 are arranged parallel to each other and spaced apart. However, it is also conceivable that the two cutting edges 31.1, 31.2 are arranged at an angle to each other. This is illustrated by the example of the middle cutting projection 50. Preferably, the two cutting edges 31.1, 31.2 converge towards the free end of the cutting projection 50. It is possible that the two cutting edges 31.1, 31.2 are transitioned into each other at the free end of the cutting element 30 by means of a cutting tip 36. The cutting tip 36 can be designed as a rounded edge to reduce the risk of breakage.

[0043] Preferably, the cutting element(s) 30 have a uniform thickness in the direction of the height of the cutting tool 10, which is composed of Fig. 4 results. Preferably, the thickness of the cutting element(s) 30 is selected in the range between 1.5 mm and 4 mm.

[0044] In the Fig. 3 and Fig. Figure 4 shows an interchangeable connection of the at least one cutting element 30. However, it is also conceivable that the cutting element 30 is additionally or alternatively connected to the cutting support 21 by means of a material-bonded connection.

[0045] For example, an adhesive bond or a solder joint can be used as a material-bonded connection.

[0046] The material-bonded connection can be formed between a preferably flat connecting surface 35 facing the cutting support 21 and an opposing support surface of the cutting support 21.

[0047] If, in addition to the material-bonded connection, a fastening element 40 is used, the cutting element 30 can be pre-tensioned relative to the cutting element holder 21 to create a consistent gap thickness in the material-bonded connection. Alternatively, once the material-bonded connection is formed, the fastening element 40 can be removed, leaving the cutting element 30 held on the cutting element holder 21 solely by the material-bonded connection.

[0048] In the Fig. Figures 6-8 illustrate an embodiment of the invention. In this embodiment, the cutting elements 30 are connected to the cutting element carriers 21 exclusively by means of a material-bonded connection, preferably a soldered or adhesive bond.

[0049] Furthermore, the design of the cutting tool 10 corresponds to the design variant according to the Fig. 1-5, so that reference can be made to the above statements.

[0050] Fig. Figure 9 shows a detail of a cutting tool 10 according to the Fig. 6-8, from which the design of the cutting elements 30 and the cutting element carrier 21 can be seen in more detail. As this illustration shows, the cutting element(s) 30 may project laterally beyond the cutting element carrier 21 in the direction of the width B with the cutting edge(s) 31.1, 31.2. Furthermore, the flanks of the cutting element carrier 21 adjoining the cutting edges 31.1, 31.2 at the bottom may be angled in a V-shape to each other in order to form clearance surfaces in the direction of the height of the cutting tool 10, as shown by the Fig. 9 clearly shows.

[0051] However, it is also conceivable that at least one cutting edge 31.1, 31.2 transitions flush into the cutting carrier 21, i.e., that it does not protrude laterally in the direction of the width.

[0052] The illustrations further show that the cutting element 30 can have a front surface 32 that closes off the cutting element 30 at its free end facing away from the carrier 11. This front surface 32 may be protected behind a shaped surface of the cutting carrier 21. For example, it may be such that Fig. Figure 4 illustrates that this shaped surface is formed by the connecting element 22.

[0053] Advantageously, the cutting element 30 has a back surface 33 which, facing the carrier 11, closes off the cutting element 30. The cutting element 30 can be inserted into a receptacle, in particular a milled recess in the cutting carrier 21, so that the back surface 33 can be positioned precisely in this recess. Thus, the cutting element 30 is precisely aligned with the cutting carrier 21.

[0054] The cutting element 30 has a cutting surface 34 that transitions into at least one cutting edge 31.1, 31.2. Advantageously, the cutting edge 31.1, 31.2 forms a transition between the cutting surface 34 and a lateral surface of the cutting element 10, as shown. Fig. 9 shows.

[0055] In the Fig. Figures 10-12 show a further embodiment of the invention. The same reference numerals are labelled with the same terms so that reference can be made to the preceding explanations to avoid repetition.

[0056] As the illustrations show, instead of a single cutting element 30 with two cutting edges, two cutting elements 30, each with one cutting edge 31.1, 31.2, are also installed with a cutting element carrier 21. Preferably, each of the cutting elements 30 is positioned in a recess of the cutting element carrier 21, as shown. Fig. 10 clearly shows.

[0057] In Fig. Figure 12 shows a further embodiment of a cutting element 30. The one in Fig. The detail shown in section 12 can also be applied to the remaining cutting elements 30 according to the Fig.1-11 are applied. As this illustration demonstrates, the cutting element 30 has a clearance surface 38. The clearance surface 38 is inclined at an angle of less than 90° to the cutting surface 34, resulting in a clearance angle α. Preferably, the clearance angle α is selected in the range between 45° and 75°. The illustration further demonstrates that the cutting element carrier 21 can have a flank 27 following the cutting element 30, which tapers the cross-section of the cutting element carrier 21 below the cutting element 30. Preferably, the angle of this flank 27 is selected to be equal to the angle of inclination between the clearance surface 38 and the cutting surface 34, with a deviation of ±10°. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] EP 3 744 164 A1

[0004]

Claims

[1] Cutting tool (10) for an agricultural or forestry cutting unit with a carrier (11) having a knife longitudinal guide (14), wherein the carrier (11) has at least one cutting projection (20, 50) having a cutting support (21), wherein a cutting surface (34) is arranged in the area of ​​the cutting support (21), which is designed and arranged such that a cutting knife is adjustable along a cutting plane relative to the cutting surface (34), characterized by , that a cutting element (30) made of a more wear-resistant material than the material of the cutting element (21) is attached to the cutting carrier (21), and that the cutting element (30) has at least one cutting edge (31.1, 31.2) which runs along or substantially along a cutting edge side of the cutting projection (20, 50) and which transitions into the cutting surface (34). [2] Cutting tool (10) according to claim 1, characterized by, that the cutting surface (34) is formed by the cutting element (30). [3] Cutting tool (10) according to claim 1 or 2, characterized by , that the cutting element (30) has a cutting edge (31.1, 31.2) on each of its opposite longitudinal sides, wherein the cutting edges (31.1, 31.2) each run along a cutting edge side of the cutting projection (20, 50). [4] Cutting tool (10) according to one of claims 1 to 3, characterized by , that the cutting edges (31.1, 31.2) run parallel to each other or converge towards the free end of the cutting attachment (20, 50). [5] Cutting tool (10) according to any one of claims 1 to 4, characterized by , that the cutting element (30) is formed by a hard material shaped piece, in particular by a hard metal shaped piece. [6] Cutting tool (10) according to any one of claims 1 to 5, characterized by, that the cutting element (30) has a front surface (32) facing the free end of the cutting projection (20, 50), and that the front surface (32) is at least partially covered by a body edge of the cutting projection (20, 50) transverse to the longitudinal extent of the cutting edge (31.1, 31.2). [7] Cutting tool (10) according to any one of claims 1 to 6, characterized by , that the cutting element (30) has a rear side (33) facing away from the free end of the cutting projection (20, 50), which is opposite a side surface of a transition section (16), wherein the transition section (16) forms a transition between the knife longitudinal guide (14) and the cutting projection (20, 50). [8] Cutting tool (10) according to any one of claims 1 to 7, characterized by, that the cutting element (30) has a lower, preferably flat, connecting surface (35) by means of which the cutting element (30) is materially connected to an opposite counter surface of the connecting section (22) of the cutting attachment (20, 50), wherein it may in particular be provided that a materially bonded connection, in particular a soldered, an adhesive and / or a welded connection, is arranged between the counter surface and the connecting surface (35). [9] Cutting tool (10) according to any one of claims 1 to 8, characterized by , that the two converging cutting edges (31.1, 31.2) merge into each other in the area of ​​the free end of the cutting attachment (50) by means of a cutting tip (36) of the cutting element (30). [10] Cutting tool (10) according to any one of claims 1 to 9, characterized by, that the cutting element (30) is interchangeably connected to the cutting attachment (20, 50), preferably by means of at least one fastening element (40), in particular by means of at least one screw. [11] Cutting tool (10) according to any one of claims 1 to 10, characterized by , that the cutting attachment (20, 50) has a cover section (23) which is spaced apart from the cutting carrier (21), wherein a knife gap (24) is formed between the cutting carrier (21) and the cover section (23), and that the cutting element (30) which is carried by the cutting carrier (21) limits the knife gap (24) at least in some areas by means of its cutting surface (34). [12] Cutting tool (10) according to claim 11, characterized by, that the deck section (23) in the area of ​​the knife gap (24) carries at least one further cutting element (30) which is designed as a separate component and is connected to the deck section (23), preferably interchangeably connected, wherein it is particularly preferred that the cutting element (30) and the further cutting element (30) are designed as identical parts. [13] Cutting tool (10) according to any one of claims 1 to 12, characterized by , that the / a cover section (23) of the cutting attachment (20) is arranged at a distance from the cutting attachment carrier (21) by means of a connecting element (22) arranged at the end of the cutting attachment (20), such that the knife gap (24) is formed between the cover section (23) and the cutting attachment carrier (21). [14] Cutting tool (10) according to any one of claims 1 to 13, characterized by, that the at least one cutting element (20, 50) with the cutting element (30) attached thereto forms a first component which is connected to a second component which preferably has the knife longitudinal guide (14), preferably interchangeably or non-interchangeably, for example welded. [15] Cutter bar for a combine harvester header, a double knife mower, a double knife cutter, a sickle bar mower, a hedge cutter or a pruning shear, with at least one cutting tool (10) according to any one of claims 1 to 14.

Images