EP2949438B1 - Plant mill for producing gauged particles - Google Patents

Description

The present invention relates to an apparatus for reducing chip branches, according to the preamble of claim 1. Such an apparatus is known from the document FR2946913 A1 .

BACKGROUND OF THE INVENTION

• les appareils à tambour destinés à la découpe ou au déchiquetage des branches de diamètre important, typiquement supérieur à 350 millimètres, (voir WO 9413442 par exemple),
• les appareils à disque pour traiter les branches de diamètre plus petit. Les particules issues de ces machines sont de taille variable, surtout pour ce qui concerne les machines à disque. Dans ce dernier cas, l'état de la technique le plus proche est constitué par le document FR 2.946.913 . Ce document décrit un appareil qui comporte, dans un carter avec une ouverture frontale bordée d'une lame fixe, un disque plein logé à rotation dans le carter, divisant l'espace intérieur de ce dernier en une chambre de déchiquetage du côté de l'ouverture et une chambre de soufflerie du côté de la paroi de fond. Ce disque est porteur de couteaux en relief sur la face du disque qui croisent la lame fixe lors de la rotation du disque. Autour de ce disque de couteaux, il existe une grille fixe de calibrage traversée par les particules de bois de petites dimensions et dans les mailles de laquelle se logent les particules de bois de plus grandes dimensions, retenues par une sorte de plaque de calibrage qui tourne avec le disque et qui permet à un couteau périphérique de ce dernier de réduire la taille de ces particules trop grandes.

The state of the art in this field consists of two types of equipment:

• drum machines intended for cutting or shredding branches of large diameter, typically greater than 350 millimeters, (see WO 9413442 for example),
• disc machines to treat branches of smaller diameter. The particles from these machines are of variable size, especially with regard to disk machines. In the latter case, the closest state of the art is the document FR 2,946,913 . This document describes an apparatus which comprises, in a casing with a front opening bordered by a fixed blade, a solid disc rotatably housed in the casing, dividing the internal space of the latter into a shredding chamber on the side of the casing. opening and a blower chamber on the side of the bottom wall. This disc carries knives in relief on the face of the disc which cross the fixed blade during the rotation of the disc. Around this blade of knives, there is a fixed grid of calibration crossed by the particles of small wood and in the meshes of which are lodged the particles of wood of larger dimensions, retained by a sort of calibration plate which turns with the disc and that allows a peripheral knife of the latter to reduce the size of these too large particles.

It has been realized that the production of particles calibrated with this device is accompanied by the production of a fine sawdust in large quantity which reduces the output of the production of calibrated chips and which requires a frequent and careful maintenance of the apparatus.

The present invention is an improvement of this state of the art so as to reduce this production of fine particles.

OBJECT OF THE INVENTION

• un carter fermé par une paroi frontale, une paroi de fond et une paroi latérale sensiblement cylindrique, avec, dans la paroi frontale une ouverture d'entrée du bois à traiter bordée d'au moins une lame fixe et, dans la paroi latérale, une ouverture de sortie des plaquettes ou particules,
• un disque plein logé à rotation dans le carter autour d'un axe sensiblement perpendiculaire aux parois frontale et de fond du carter, divisant l'espace intérieur de ce dernier en une chambre de déchiquetage du côté de la paroi frontale et une chambre de soufflerie du côté de la paroi de fond,
• au moins une série de couteaux comprenant des premiers couteaux en relief sur la face du disque tournée vers la paroi frontale de manière que ces couteaux croisent la lame fixe lors de la rotation du disque et au moins un deuxième couteau de reprise fixé au voisinage de la périphérie du disque pour balayer une surface cylindrique centrée sur l'axe de rotation du disque,

caractérisé en ce que le disque comporte, à l'extérieur du deuxième couteau de reprise et dans la chambre de déchiquetage, une grille dont la maille crible les particules, cette grille étant écartée vers l'extérieur du couteau de reprise de manière à définir entre eux un espace dans lequel pénètre au moins un doigt fixe, porté par la paroi frontale, pour former une lame fixe croisée par le bord intérieur des mailles de la grille et par le couteau de reprise au voisinage de son passage devant l'ouverture de sortie des plaquettes ou particules.For this purpose, the subject of the invention is therefore a plant crusher for the production of calibrated wood chips or particles, comprising:

• a housing closed by a front wall, a bottom wall and a substantially cylindrical side wall, with, in the front wall, an entrance opening of the wood to be treated bordered by at least one fixed blade and, in the side wall, a exit opening of platelets or particles,
• a solid disc rotatably housed in the housing about an axis substantially perpendicular to the front and bottom walls of the housing, dividing the interior space of the latter into a shredding chamber on the side of the front wall and a blower chamber of the side of the bottom wall,
• at least one set of knives comprising first knives in relief on the face of the disk facing the front wall so that these knives cross the fixed blade during the rotation of the disk and at least a second knife recovery fixed in the vicinity of the periphery of the disk for scanning a cylindrical surface centered on the axis of rotation of the disk,

characterized in that the disk comprises, outside the second recovery knife and in the chipping chamber, a grid whose mesh screens the particles, this grid being spread towards the outside of the recovery knife so as to define between them a space in which at least one fixed finger, carried by the front wall, to form a fixed blade crossed by the inner edge of the mesh of the grid and the knife of resumed in the vicinity of its passage in front of the outlet opening of platelets or particles.

The present invention includes some of the additional features as already described in the state of the art. Thus, the front blank of the disc forms the support of the material to be treated and from which the first knives project in the direction of the inlet opening of the housing. In front of the first knives in the direction of rotation of the disk, this blank is scalloped from a pocket for collecting formed particles whose peripheral opening faces the grid. This disk structure can channel the trajectory of most of the chips or particles subjected to centrifugal force and have just been detached in the direction of the grid, so to constrain the particles to cross the grid.

Other features and advantages of the invention will emerge from the description given below of an exemplary embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

• par la figure 1, une vue extérieure du côté frontal de l'appareil selon l'invention dont un panneau de la paroi frontale est ouvert,
• par la figure 2 une vue du disque mis en oeuvre dans l'appareil de l'invention

Reference will be made to the accompanying drawings which represent

• over there figure 1 an external view of the front side of the apparatus according to the invention, a panel of the front wall is open,
• over there figure 2 a view of the disk implemented in the apparatus of the invention

DETAILED DESCRIPTION OF THE INVENTION

The mill of the invention shown in the figures therefore comprises a casing 1 formed of a front wall 2, a rear wall or bottom 3 and a substantially cylindrical side or peripheral wall 4.

The front wall has a fixed lower portion 2a, and an opening panel 2b. The latter is provided with an opening 5. When the opening panel is folded down on the fixed part, the opening 5 is completed by a lower edge and a lateral edge, one equipped with a fixed blade or against the blade. substantially horizontal and the other of a fixed blade or cons-blade 7 substantially vertical.

Through this opening 5 is introduced the end of the branch to reduce chips. This introduction is carried out by means of a charging hopper 8 (partially shown) which can be motorized in a known manner. Under the cutting force, this branch tends to wedge in the angle formed by the two against-blades. The bottom wall 3 of the housing is traversed by a shaft drive shaft 9 and a bearing is provided for this purpose. The side wall 4 of the housing has an outlet opening 10 located in such a way that the conduit 11 which extends it forms a tube which escapes from the housing tangentially to the wall 4 of the latter. Inside this casing, a disc 12 is rotatably mounted in the direction of the arrow A of the figures, wedged on the axis shaft 9. The diameter of this disc is smaller than that inside the lateral wall 4 of the carter for the reasons that will be explained below.

The disc 12 comprises a rear flank 13, a front blank 14, of smaller diameter than the rear flank, the two blanks being connected by a peripheral belt 15 indented at two diametrically opposite locations 16a and 16b (see FIG. figure 2 ). The width of this belt 15 is such that it is overflowing on the front face of the blank 14. The front blank has two cutouts 17 and 18 which leave the rear blank uncovered. At the rear edge of each of them, in the direction A of rotation of the disc, the disk carries knives 19 in the form of plates reported on this disk by screws to front access. The knives extend along a substantially spiral curve from the vicinity of the center of the blank 14 of the disk to the periphery thereof. The plane swept by these knives, in front of the front face of the blank 14 of a value substantially equal to the projecting thickness of the cutting inserts 19 and the edge of the belt 15 relative to this face, is immediately behind the plane that contains the back edge of the counter-blades 6 and 7.

It is understood that the wood introduced into the opening 5 (window) is nibbled (shredded) at each passage of a line of knives 19.

The disc 12 thus has, in the illustrated case, two lines of knives 19. At the end of each of these lines, the disc 12 has another knife 20, also in the form of an insert plate, whose attachment to the disc is achieved by radial access screws. The cylindrical surface swept by the cutting edge of these plates 20 is of intermediate diameter between the diameter of the rear blank 13 and the diameter of the front blank 14. In addition, this diameter is greater than that of the belt 15. The axial dimension of this knife 20 is substantially equal to the distance separating the two blanks 13, 14 of the disk, increased by the projection of the first knives 19 on the front blank, so is equal to the width of the belt 15. The projection of each plate 19 relative to the front face of the front blank 14, defines the axial dimension (in the direction of the axis 9) of the chipping chamber (nibbling) of the product introduced into the apparatus. The cutouts 17 and 18 are therefore equipped with knives 19 on their rear edge. The outline of these cuts is connected by the support of the knives and by appropriate partitions to the blank 13 of the disc, so that in the thickness of the disk, it is formed pockets for collecting chips or particles from the cut by the knives 19. The centrifugal force tends to propel these particles towards the notches 16a and 16b of the wall belt 15.

The shredding chamber, which also comprises these two pockets, is delimited at the periphery, inside the cylindrical wall 4, by a grid 21 integral with the inner face of the rear blank 13 of the disk 12.

The chips contained in the chipping chamber fill the pockets and, under the effect of the centrifugal force, penetrate into the annular space between the belt 15 and the grid 21.

The inner face of the opening panel 2b of the front wall 2 has protuberances 22, here three in number, which are presented as fixed plates perpendicular to this face whose dimensions are such that they are housed in the aforementioned annular space between the grid 21 and the peripheral knives 20 when the panel 2b is folded back to the service position. These plates 22 behave as fixed blades that cut the particles between the inner periphery of the grid knives 20 and this, at the location and in front of the passage pockets 17 and 18 and the notches 16a and 16b in front of the opening of 10. The particles that can then escape through this opening are those that are calibrated by the dimensions of the mesh of the grid and the width of the annular space swept by the fixed blades 22. It has been found that the means of the invention allow better calibration with less energy expenditure.

In known manner, the disc 12 is equipped, at the rear of its blank 13, with a series of ventilation fins 13a which form a drive blower. particles that reach the evacuation conduit 11.

Finally, it will be noted that in the grinder according to the invention the grid 21 is removably attached to the disc 12 so that the user can remove it. He then has an ordinary mill that he can use for the sole purpose of a reduction of a plant material without calibration constraints. The mill of the invention can thus be used more cost-effectively.

Claims (3)

1. Plant disintegrator for producing calibrated wood slices or particles, comprising:

   - a casing (1) closed by a front wall (2), a back wall (3) and a substantially cylindrical side wall (4), with, in the front wall, an opening (5) for the wood to be treated to enter, bordered by at least one fixed blade (6, 7) and, in the side wall (4), an outlet opening (10) for the slices or particles;

   - a solid disc (12) housed for rotation in the casing about an axis (9) substantially perpendicular to the front wall (2) and back wall (3) of the casing, dividing the internal space of the latter into a shredding chamber on the same side as the front wall (2) and a blower chamber on the same side as the back wall (3),

   - at least one series of blades (19, 20) comprising first blades (19) in relief on the face of the disc (12) turned towards the front wall (2) so that these blades intersect the fixed blade (6, 7) when the disc (12) rotates, and at least one second reworking blade (20) fixed in the vicinity of the periphery of the disc (12) in order to sweep a cylindrical surface centred on the rotation axis (9) of the disc,

   characterised in that the disc (12) comprises, outside the second blade (20) and in the shredding chamber, a grille (21) the mesh of which sieves the particles, this grille (21) being separated towards the outside of the reworking blade (20) so as to define between them a space in which at least one fixed finger (22) carried by the front wall (2) enters in order to form a fixed blade intersected by the inside edge of the meshes of the grille (21) and by the reworking blade (20) before it passes in front of the particle-discharge opening (10).
2. Plant disintegrator for producing calibrated wood slices or particles according to claim 1, characterised in that the disc (12) has a front face (14) from which the first blades (19) project in the direction of the inlet opening (5) of the casing (1), and in that, in front of the first blades (19) in the direction (A) of rotation of the disc (12), the front face (14) is hollowed out by at least one pocket (17, 18) for collecting the particles having a peripheral opening (16a, 16b) turned towards the grille (21).
3. Plant disintegrator for producing calibrated wood slices or particles according to claim 2, characterised in that, between the rear face (13) and the front face (14) of the disc (12), the latter comprises a cylindrical peripheral wall (15), hollowed out (16a, 16b) at the opening of each pocket (17, 18), the radius of which is less than the radius of action of the second blade (20), and the axial dimension of which is substantially equal to the distance separating the two faces of the disc plus the projection of the first blades (19) on the front face (14).

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