FR3092963A1 - AGRICULTURAL MACHINE CUTTING TOOL ELEMENT AND CORRESPONDING AGRICULTURAL MACHINE - Google Patents

Abstract

This cutting element (8) for an agricultural machine comprises a hooking zone (9) on a shackle, defining a first plane (P9), as well as a cutting zone (10) having lateral sharp edges (12), this cutting area (10) defining a second plane (P10) forming a non-zero angle with the first plane (P9), said cutting area (10) having, on one face, a thinned area, characterized in that at at least one positive relief (21) is provided on the cutting area (10), said relief (21) being located on the face (14) opposite to that in which the thinned area is formed and in that the relief (21) is positioned opposite the thinned beach. The invention also relates to a cutting tool equipped with several cutting elements (8) and an agricultural machine with at least one such cutting tool. Figure to be published with the abstract: Fig. 2

Description

AGRICULTURAL MACHINE CUTTING TOOL ELEMENT AND CORRESPONDING AGRICULTURAL MACHINE

The present invention relates to an agricultural machine cutting tool element, generally referred to as an agricultural machine cutting rotor. A cutting tool consists of several cutting elements. The invention also relates to an agricultural machine comprising at least one such cutting tool.

An agricultural-type machine, targeted by the invention, is intended in particular for mowing or clearing brush of roadsides, in particular slopes of roads and highways. Such a machine comprises a frame, on which is mounted at least one cutting tool. The latter comprises a rotor, rotating around an axis generally perpendicular to the direction of advance of this machine, as well as cutting elements, particularly called knives or flails. These cutting elements are generally distributed over the length and circumference of the rotor.

According to a known solution from FR-A-2 900 022, the cutting elements are mounted in pairs on an intermediate connecting member, also called a shackle, which is articulated on the rotor and cooperates with each cutting element. The latter consists of an attachment zone on the shackle, defining a first plane, as well as a cutting zone, defining a second plane forming an angle with the aforementioned first plane.

In general, each shackle supports two identical cutting elements, which are mounted "back to back" so that they form a Y when viewed from the side. These two cutting elements are not mutually integral and can even move slightly in translation, both along the shackle and perpendicular to it. Therefore the movement of each cutting element, relative to the rotor, is complex.

In service, during the advance of the agricultural machine, the rotor starts to rotate which causes, due to the centrifugal force, a displacement of the cutting elements outward. The side edges of these elements, which form sharp edges, then come into contact at high speed with the plants, which makes it possible to cut the latter.

It will be understood that it is particularly important that the cutting edges retain their cutting properties as the agricultural machine is used. Indeed, poor cut quality requires at least one additional passage of the machine over the area to be treated, which is counterproductive. In addition, in the event of significant wear of the cutting elements, it is then necessary to disassemble them from the rotor. This operation is relatively long and complex, so it should be carried out as infrequently as possible.

In order to limit the wear of the cutting elements, we know from FR-B-3 018 152, filed by the applicant, a cutting element for an agricultural machine, intended to be mounted on a rotor of said machine, by means of of a shackle articulated on this rotor, said element comprising a catching zone on the shackle, defining a first plane, as well as a cutting zone defining a second plane forming a non-zero angle with the first plane. The sectional area has, in section, the shape of an arc, the concavity of which faces the foreground. This cutting zone includes a thinned area bordered by a peripheral recess. In this way, with the arched shape of the cutting zone, it is possible to define a wider cutting zone, while preserving the initial mass of the cutting element thanks to the thinned area, the latter being substantially in the central position. on the cutting element. It turns out, however, that, under certain particularly difficult working conditions, for example due to the presence of stones, there is a risk of breakage or cracking at the level of the thinned area.

It is to this drawback that the invention proposes to remedy by providing a cutting element with optimum cutting edge life, with retained mass and optimized impact resistance.

To this end, the invention relates to a cutting element for an agricultural machine, intended to be mounted on a rotor of said machine by means of a shackle articulated on this rotor, said element comprising a hooking zone on the shackle, defining a first plane, as well as a cutting zone having sharp lateral edges, this cutting zone defining a second plane forming a non-zero angle with the first plane, said cutting zone having, on one face, a thinned area bordered by a peripheral recess, characterized in that at least one positive relief is provided on the cutting area, said relief being located on the face opposite to that in which the thinned area is formed and in that the relief is positioned opposite the thinned beach.

Thus, a cutting element is produced, the cutting zone of which, de facto, does not exhibit any zone of structural weakness of the fit of the thinned area. Such a configuration makes it possible to optimize the mechanical strength of the element without increasing its nominal mass.

According to advantageous but not mandatory aspects of the invention, such a cutting element may include one or more of the following characteristics:

- a single relief occupies an area equivalent to that of the beach.

- Several reliefs occupy an area equivalent to that of the beach.

- Over at least part of the length of the cutting zone, the edge of the cutting zone, called interior, which is turned towards the foreground and the edge of the cutting zone, called exterior, which is opposite to the first plane, have in cross section the shape of an arc whose concavity is turned towards the foreground.

The subject of the invention is also a cutting tool for an agricultural machine, comprising a rotor, several shackles articulated on this rotor and several cutting elements conforming to any one of the preceding characteristics, the attachment zone of each cutting element cooperating with the shackle, this cutting element having at least one degree of freedom in rotation with respect to this shackle, and optionally at least one degree of freedom in translation with respect to this shackle.

Finally, the subject of the invention is an agricultural machine comprising at least one cutting tool as described above.

The invention will be better understood and other advantages thereof will appear more clearly on reading the description which follows, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

is a perspective view of a cutting tool according to the invention,

is a perspective view from the front face, on a larger scale, of a cutting element according to the invention and belonging to the cutting tool of FIG. 1,

is a perspective view, similar to Figure 2 from the rear face of the cutting element of Figure 2,

is a front view, on the same scale, of the element of the previous figures and

is a side view, to the same scale, of the cutting element of the previous figures.

FIG. 1 illustrates a cutting tool according to the invention, designated as a whole by the reference 1, which is intended to equip an agricultural machine. The latter, not shown, is in particular a mower or a brush cutter, for example for a highway embankment. This tool 1 firstly comprises a rotor 2, known per se, which is rotatably mounted about an axis A2, generally perpendicular to the direction of advance of the agricultural machine.

The rotor 2 is equipped with several supports 3, each of which is formed by two facing tabs 4, each pierced with a passage hole 5 for a threaded rod 6. Each support, which is fixed to the rotor by any suitable means, in particular by welding, allows the articulation of a shackle 7, forming an intermediate connecting member. This shackle 7 in turn supports two identical knives or flails 8, forming cutting elements within the meaning of the invention, which are made for example of forged steel.

Subsequently, for ease of reading, the terms knife, flail or cutting element will be used interchangeably to designate the cutting element 8.

In Figure 1, there is shown a single shackle 7 and a single pair of knives 8, which are mounted back to back so that they form a Y, seen from the side. Of course, each support 3 allows the articulation of a corresponding shackle, which in turn supports two knives mounted back to back. However, provision can also be made for the two flails to be mounted face to face, or else for a single knife to be associated with a given shackle.

FIG. 2 illustrates a cutting element or flail 8 according to one embodiment of the invention. This comprises, in the usual way, an attachment zone 9 defining a plane P9, as well as a sectioning zone 10, defining a plane P10. In side view, as shown in FIG. 5, these two planes P9 and P10 form an angle α, generally between 30 and 60 °, advantageously between 40 and 50 °, preferably close to 45 °.

With particular reference to FIGS. 2 to 4, the attachment zone 9 is hollowed out with a through hole 11. Here, the orifice 11 is oblong. In a variant not shown, it has another shape, for example circular. Once the beam 8 is mounted on the shackle 7, the walls of the orifice 11 define a functional play with the branches of the shackle. Consequently, each flail or knife 8 can pivot and move in translation along the rod 6.

The cutting zone 10 is substantially rectangular and has two sharp side edges 12, as well as a front face 13. This front face 13 defines, de facto, the end edge of the cutting zone 10.

By convention, the interior of the cutting zone 10 is designated as being the face 14 facing the attachment zone 9, while its exterior is formed by the opposite face 15. Finally, we note A8 the main median axis of the knife 8.

The cutting edges12 of the cutting zone extend over the entire height H of the latter. Two shoulders 16 provide the connection between the ridges 12 and the attachment zone 9.

The transverse profile of the cutting zone 10, namely along an axis perpendicular to that A8 is defined by the front face 13 of the cutting zone 10.

The lower 17 and upper 18 edges respectively of the front face 13 are configured as an arc of a circle. The edges 17 and 18, and therefore de facto the face 13, have a concavity turned towards the face 14 of the cutting zone 10.

This profile of the edges 17 and 18, in the form of arcs, is present over a length which is greater than at least 50%, in particular at least 90% of the width L of the cutting zone 10. Preferably, this cutting zone 10 has this type of profile substantially over its entire width L.

The outer face 15 of the cutting zone 10 is hollowed out with a recess, which delimits a thinned area 19 bordered by a peripheral indentation 20. We firstly denote s19 and S10 the respective surfaces of the thinned area 19 and of the cutting zone 10. In addition, e19 is the thickness of the pad, and E13 the greatest thickness of zone 10, namely the thickness at the widest level of the front face 13, therefore in the zone where the edges 17 and 18 are the furthest apart.

Advantageously, the surface s19 is not negligible compared to that S10, while the thickness e19 is significantly less than that E13. In this way, the presence of the pad 19 allows a significant reduction in material.

In order to reinforce the structural resistance of the thinned area 19, and therefore de facto of the flail 8, at least one relief 21 is provided on the face 14 of the cutting zone 10. Subsequently, the term rib will also be used to denote the relief 21. The rib 21 advantageously occupies a surface s21 equivalent to that s19 occupied by the pad 19. As a variant, it occupies a smaller area than the surface s19 of the pad 19.

Likewise, the height H21 of the relief, or rib, is substantially identical to the depth of the pad 19, therefore to the difference in altitude between the face 15 and the bottom 22 of the pad 19. It should be noted that the edges sides of the rib defining the height H21 participate in reinforcing the structural resistance of the cutting zone, in the manner of a strut.

In this way, by the presence of the rib 21, a substantially identical material thickness is obtained over the entire cutting zone 10 but with a variable distribution of thicknesses over this zone.

This results in a similar mass between a beam devoid of relief 21 and without a land 19 and a beam 8 provided with a relief 21 and a land 19. In other embodiments not shown, there are several reliefs. or ribs, identical or provided on the face 14. In all cases, the relief (s) improves (s) the mechanical strength of the beam, without significantly increasing its mass.

Advantageously, the thinned area 19 and the relief 21 are produced by the same machining operation. For this, instead of proceeding by removing material, the face 15 is stamped over a distance substantially equal to the nominal thickness of the material. scourge. Thus, the material of the face 15 is pushed back in the direction of the face 14. The land 19 and the relief 21 are thus obtained. In such a case, it is understood that the land 19 and the relief 21 have the same geometric configuration. The process is suitable for moving material without reducing the thickness. Indeed, if such were the case, one would form zones of structural weakness, by the less thickness which would harm the mechanical resistance of the beam 8.

As a variant, it is possible to add the relief 21 by a technique known per se such as welding, gluing or the like.

By convention, the height of the rib 21 or relief is defined here as being the height between the surface of the face 15 of the cutting zone 10 and the visible upper face of the rib 21. In all cases, whatever the height. technique for producing the relief (s) 21, the minimum height of the relief (s) is 7mm, generally between 7 mm and 16 mm. In addition, to optimally perform the reinforcement function, the minimum surface s21 of the relief 21 must represent at least 60% of the surface s19.

Whatever the configuration of the relief (s) 21, the latter (s) must be positioned at the level of the thinned area 19, so that the total thickness of the knife 8 is similar at all points to the central part 100 of the cutting zone 10, without the presence or absence of the area and / or the relief influencing this total thickness. In other words, according to an advantageous embodiment, the invention is obtained without any element or addition of mass with respect to the initial knife 8, devoid of land and / or relief. It will be understood that the relief 21 may have a different surface state from the rest of the beam 8, in order to facilitate its identification.

In Figures 2 and 4, it is noted that the end 210 of the relief 21 located closest to the front face 13 is configured in a V open towards the face 13. Such a shape is different from that of the thinned area 19, at the same level. The V-shape makes it possible to achieve a regular increase in the height of the relief 21, relative to the face 14, while limiting the effect of stair treads. Alternatively, the end 210 is of another geometric shape.

When the agricultural machine is in use, the rotor 2 is rotated around its axis A2. Each shackle rotates itself relative to the rotor, around a corresponding A7 axis. Finally, as explained above, each knife 8 moves relative to its shackle, according to a complex movement involving a rotation and two translations.

Due to the advance of the machine, the cutting edges 12 of each knife come into contact with the vegetation, which produces the cutting operation. It will be understood that, as they are put into service, these knives are worn at the level of these cutting edges. It should be noted that, thanks to the particular transverse profile of the cutting zone 10, these ridges 12 are capable of retaining their properties, even after prolonged use.

The Applicant has also found that, surprisingly, the presence of the thinned area 19 and of the relief 21 makes it possible to maintain optimum mechanical strength of the flail 8. Consequently, by keeping the mass of the knife and its mechanical strength unchanged, it is possible to increase the width, which makes it possible to lengthen the duration of use of this knife. It should be noted that the pad can have different shapes, which make it possible in particular to identify different knives, for example with regard to their constituent material. In such a case, taking into account the preferred embodiment of the reliefs, these also have the same shape. Thus, it is easy to identify a plague, regardless of the face from which it is viewed.

Once the cutting operation is complete, the rotor is stopped, causing each knife to strike against the surface of that rotor. From this perspective, the presence of the shoulders is advantageous.

Claims (6)

Cutting element (8) for an agricultural machine, intended to be mounted on a rotor (2) of said machine by means of a shackle (7) articulated on this rotor (2), said element (8) comprising a zone hooking (9) on the shackle (7), defining a first plane (P9), as well as a cutting zone (10) having sharp lateral edges (12), this cutting zone (10) defining a second plane (P10) forming a non-zero angle (α) with the first plane (P9), said cutting zone (10) having, on one face (15), a thinned area (19) bordered by a peripheral recess (20) , characterized in that at least one positive relief (21) is provided on the cutting area (10), said relief (21) being located on the face (14) opposite to that (15) in which the area is formed thinned (19) and in that the relief (21) is positioned opposite the thinned area (21). Element according to Claim 1, characterized in that a single relief (21) occupies an area (s21) equivalent to that (s19) of the area (19). Element according to Claim 1, characterized in that several reliefs occupy an area equivalent to that (s19) of the surface (19). Element according to Claim 1, characterized in that over at least part of the length (L) of the cutting zone (10), the edge (18) of the cutting zone (10), called inner, which is turned towards the foreground (P9) and the edge (17) of the cutting zone (10), said outside, which is opposite the foreground (P9), have in cross section the shape of an arc whose concavity is turned towards the foreground (P9). Cutting tool (1) for an agricultural machine, comprising a rotor (2), several shackles (7) articulated on this rotor and several cutting elements (8) according to any one of the preceding claims, the hooking zone ( 9) of each cutting element (8) cooperating with the shackle (7), this cutting element having at least one degree of freedom in rotation with respect to this shackle (7), and optionally at least one degree of freedom in translation with respect to this shackle (7). Agricultural machine comprising at least one cutting tool (1) according to claim 5.