EP0990494B1 - Apparatus for comminuting blocks of natural or synthetic organic material such as wood - Google Patents

Abstract

The machine has a rotating drum (18) which is rotated around an axis (20) by a rotational control system (22). the drum is fitted with interchangeable cutters (44), arranged parallel to the axis (20). The machine also includes a fixed block feed channel (34) , whose first end is near to the exterior of the basket and whose second end in the drum (18) in front of the cutters (44). A controlled endless screw (36,38) advances the blocks in the channel (34) to the cutters at a controlled constant speed. The speed control system can vary the speed of advancement of the blocks to be cut.

Description

Technical area

The invention relates to a machine designed to fragment raw blocks of a natural organic material, such as wood, or synthetic, such as a polymer or a derived material. Such a machine is known from US-A-3,991,946.

The term "fragmented" here denotes indifferently any operation consisting in particular of cutting, defibrating, reducing, or calibrating the treated material. Thus, in the case of wood, the products obtained may, in particular, be in the form of platelets, chips or fibers.

In the wood industry, the machine according to the invention can in particular be used to obtain fibers for the subsequent manufacture of particle boards, paper, etc. In the plastics industry, the machine according to the invention can be used to treat or recycle certain products, as well as waste.

State of the art

The fragmentation of blocks of a material such as wood is effected under optimal conditions when the three parameters of the tangential cutting speed, the speed of advance of the product and the projection of the cutting blades are controlled.

Various machines have been developed in the past, particularly in the wood industry, to break up bulky blocks in order to obtain chips or chips. These machines are essentially of two types: horizontal or vertical disc machines and peripheral striker machines.

In horizontal or vertical disc machines, the pieces of wood are channeled in a pipe to a horizontal or vertical disk, provided with cutting blades positioned radially. Cylinders associated with the pipe control the advance of the pieces of wood, at a generally adjustable speed and can be constant.

Machines of this type make it possible to control two of the parameters which it is necessary to control to work in the best conditions. These two parameters are the protrusion of the cutting blades and the speed of advance of the product.

However, because the cutting blades are positioned radially on the disk, the cutting speed is variable and scalable depending on the distance between the cutting zone considered center of the disc. It is therefore not possible to control the tangential cutting speed. Therefore, this type of machine does not work in the best conditions.

In machines with peripheral striker bins, cutting blades are fixed in a static or rotating basket, parallel to its axis, and a central impeller rotates at high speed inside the basket.

This type of machine makes it possible to control the protrusion of the cutting blades, as well as the cutting speed. On the other hand, the speed of advance of the products introduced in the center of the machine and centrifuged by the impeller is random. In addition, this speed of advance, which results from the centrifugal force applied to the treated products, decreases proportionally to the reduction of the volume of the product during the fragmentation operation. The feed rate of the product is therefore not controlled, nor the energy consumption of the main engine. Therefore, this type of machine does not allow to work in optimal conditions either.

Presentation of the invention

The invention specifically relates to a fragmentation machine blocks of a material, such as wood, whose original design allows it to work in the best conditions, controlling both the tangential cutting speed, the speed of advance of the product, the protrusion of the cutting blades and the energy consumption of the main motor.

According to the invention, this result is obtained by means of a machine for breaking up blocks of a natural or synthetic organic material, such as wood, according to claim 1.

By combining the use of a feed channel associated with advance control means, such as in horizontal or vertical disk machines, with the completely novel use of a rotating basket carrying the cutting members, the The machine according to the invention makes it possible to control both the tangential cutting speed and the feed rate of the product, which is not the case in any of the existing machines. By adding to the control of these parameters the more conventional ability to control the protrusion of the cutting members, the machine according to the invention makes it possible to work under optimal conditions.

In a preferred embodiment of the invention, the advance control means are able to advance the blocks at a constant speed. In addition, they preferably include means for adjusting the speed.

In a variant, regulation means responsive to the energy absorbed by the rotation control means drive the advance control means to ensure a substantially constant total energy consumption.

The advance control means can take different forms. In the preferred embodiment of the invention, they comprise an Archimedean screw housed in the feed channel, as well as a drive motor for this screw. Alternatively, the advance control means may also be constituted by a jack-push assembly.

Advantageously, the cutting members are mounted on external anvils, integral with the basket, by removable fixing means.

These dismountable fastening means preferably comprise, for each cutting member, an internal clamping wedge adapted to apply the cutting member against the anvil, under the effect of the centrifugal force generated by the rotation of the basket, to the less a connecting member connecting the clamping wedge to the anvil with a clearance allowing assembly and disassembly of the cutting member, and elastic means urging the clamping wedge towards the anvil, against the aforementioned game.

Each connecting member may then comprise a screw, screwed into the clamping wedge, freely passing through the anvil and provided with a disassembly head accessible from outside the basket. With this arrangement, the cutting members can be easily removed and replaced by exerting pressure on the disassembly heads of the corresponding screws.

Each of the cutting members may in particular comprise a blade fixed on a blade holder, for example by means of screws, positioning fingers or by interlocking.

In order to be able to empty the supply channel when the machine stops, said channel advantageously comprises a dump hatch in a part situated outside the basket.

To facilitate the replacement of the cutting members, allowing complete disassembly of the basket, the feed channel is preferably movable, for example tilting or sliding, relative to the basket. The supply channel can then be brought into a maintenance position, in which it is completely outside the basket.

According to an improvement for breaking up the product in the form of fibers, the rotating basket can be mounted coaxially inside a static basket including a cylindrical wall includes, alternately, rasps and calibration zones. Percussion irons are then attached to the rotating basket, and mounted between the latter and the static basket, close to the cylindrical wall of the latter.

Moreover, the rotating basket is generally supported and surrounded by a fixed housing provided with an access door for the replacement of cutting members.

Different arrangements of the axis of the rotary basket and the supply channel or channels can be envisaged, without departing from the scope of the invention.

Thus, according to a first arrangement, the axis of the rotary basket is substantially horizontal and a single inclined and ascending supply channel opens near the upper generatrix of this basket.

According to a second arrangement, the axis of the rotating basket is substantially horizontal and two substantially horizontal supply channels enter the basket, on either side thereof.

Finally, according to a third arrangement, the axis of the rotary basket is substantially vertical and several inclined and descending supply channels open into said basket.

Brief description of the drawings

• la figure 1 est une coupe schématique qui représente un premier mode de réalisation d'une machine de fragmentation conforme à l'invention ;
• la figure 2 est une coupe, à plus grande échelle, selon la ligne II-II de la figure 1 ;
• la figure 3 est une coupe illustrant, encore à plus grande échelle, l'un des organes de coupe de la machine et les moyens de fixation démontables associés ;
• les figures 4A, 4B et 4C sont des coupes à plus grande échelle illustrant trois exemples de montage d'une lame de coupe sur un porte-lame dans la machine selon l'invention ; et
• la figure 5 est une coupe comparable à la figure 2, illustrant un deuxième mode de réalisation d'une machine de fragmentation conforme à l'invention.

Two embodiments of the invention will now be described by way of nonlimiting examples, with reference to the appended drawings, in which:

• Figure 1 is a schematic section which shows a first embodiment of a fragmentation machine according to the invention;
• Figure 2 is a section, on a larger scale, along the line II-II of Figure 1;
• Figure 3 is a section illustrating, even on a larger scale, one of the cutting members of the machine and the associated detachable fastening means;
• Figures 4A, 4B and 4C are larger scale sections illustrating three examples of mounting a cutting blade on a blade holder in the machine according to the invention; and
• Figure 5 is a section similar to Figure 2, illustrating a second embodiment of a fragmentation machine according to the invention.

DETAILED DESCRIPTION OF TWO PREFERRED EMBODIMENTS OF THE INVENTION

Firstly, with reference to FIGS. 1 to 4, a first embodiment of a fragmentation machine according to the invention will be described.

The machine comprises a frame 10, which rests on the ground 12 above a well 14.

The frame 10 is provided with means, such as a bearing 16, adapted to rotatably support a basket 18 in the form of a drum. In the embodiment illustrated in Figure 1, the axis 20 of the rotary basket 18 is substantially horizontal. The rotating basket 18 is placed above the well 14. Means 22 for controlling the rotation of the basket 18, such as an electric motor carried by the frame 10, are provided for driving the basket 18 in rotation about its axis. 20, via a shaft 24 mounted in the bearing 16.

The frame 10 comprises a casing 26 which completely envelopes the basket 18, with the exception of the lower part thereof situated above the well 14.

In the embodiment shown, the basket 18 comprises a flange 28 fixed in its central part to the shaft 24, a cylindrical cutting portion 30, which will be described in detail hereinafter, and an annular disc 32, connected to the periphery of the flange 28 by the cylindrical cutting portion 30.

The fragmentation machine according to the invention further comprises a feed channel 34 whose axis is contained in a plane passing through the axis of rotation 20 of the basket 18 and inclined, for example by approximately 45.degree. relative to this axis 20. The feed channel 34 is arranged such that its closed, low end is located outside the basket 18 and the frame 10, on the opposite side to the rotation control means 22. On the contrary, the open, upper end of the feed channel 34 is placed inside the basket 18 and opens into the latter in the immediate vicinity of the highest generatrix of the cutting region 30. Between its two ends, the feed channel 34 passes through an opening formed in the housing 26 and is fixed to the frame 10. The channel also feeds through a circular opening formed in the annular disk 32.

Advance control means are associated with the feed channel 34, in order to convey at a controlled advance speed blocks or pieces of the material to be broken up to the cylindrical cutting portion 30 of the basket 18. according to an upward movement within the channel 34.

In the embodiment illustrated in FIG. 1, these advance control means comprise an Archimedean screw 36 mounted coaxially in the feed channel 34, as well as a drive motor 38 of the screw 36, such as than a regulated electric motor. In an alternative embodiment not shown, the advance control means may also be constituted by a push cylinder or by any similar device.

The blocks or pieces of material to be fragmented are introduced into the bottom of the supply channel 34, outside the casing 26, by a chute or vertical hopper 40 opening directly into the lower part of the channel.

Thanks to the combination of at least one feed channel and a rotating basket fitted with cutting members in the cylindrical part 30, the fragmentation machine according to the invention makes it possible to control both the feed rate blocks of material to be fragmented and the tangential cutting speed of these blocks. Since the control of the protrusion of the cutting blades does not pose any particular problem, the machine according to the invention therefore makes it possible to work in the best possible conditions.

The advance control means, constituted by the Archimedes screw 36 and the motor 38 in the mode of embodiment shown, are designed so as to ensure the advance of the blocks of material in the feed channel 34 at a constant speed. In addition, means for adjusting this speed are advantageously provided, for example at the motor 38.

In a variant, regulation means associated with the motor 38 can make it possible to ensure a substantially constant total energy consumption on the machine. For this purpose, the regulation means receive signals representative of the energy absorbed by the motor 22 ensuring the rotation control of the basket 18. The control means determine, from these signals, the energy remaining available for the motor 38 and it is controlled accordingly.

A hatch 35, placed in the lower part and on the lower face of the supply channel 34, outside the casing 26, empties the channel at the stop of the machine. After opening of the hatch 35, the channel 34 is emptied by controlling a rotation in the opposite direction of the Archimedean screw 36, using the motor 38.

As is more particularly illustrated in FIG. 2, the cylindrical cutting portion 30 of the basket 18 (FIG. 1) is in the form of external anvils 46, positioned over a certain radius with respect to the axis 20 of the basket. and spaced circumferentially from each other by a small predetermined distance.

As shown in more detail in FIG. 3, each of the outer anvils 46 is integral with the basket 18 and its ends are fixed respectively to the flange 28 and to the annular disk 32. (figure 1). In addition, each of the anvils 46 comprises an interchangeable cutting member 44.

More specifically, on its face turned towards the inside of the basket 18, each anvil 46 has a recess 48 of approximately V-shaped section. Thus, with respect to the direction of rotation of the basket illustrated by the arrow F in the figure 3, each of the recesses 48 has a front flank 50 inclined at an angle α with respect to a radial direction, as well as a radially oriented rear flank 52.

The leading edge 50 of each of the recesses 48 has a recessed portion 54 whose shape is complementary to that of the cutting member 44 and in which is housed this member. More specifically, the cutting member 44 comprises a blade holder 56 which is housed in the bottom of the recessed portion 54, and a cutting blade 58, fixed to the blade holder 56 and flush with the leading edge 50 when the cutting member 44 is placed in the hollow portion 54. The cutting edge 60 of the cutting blade 58 then protrudes forwardly and inwardly, over predetermined distances, respectively with respect to the anvil 46 and with respect to a wear shoe 62 mounted inside the anvil 46, on an inner clamping wedge 64.

The wear shoe 62 is carried by the inner clamping wedge 64, whose shape is complementary to that of the recess 48, V-shaped and angle a. The clamping wedge 64 is mounted in the recess 48 and connected to the anvil 46 by one or more connecting members, such as screws 66. More specifically, each screw 66 is screwed into a threaded hole 68, machined in the clamping wedge 64, and freely passes through a hole 70 formed in the anvil 46.

The head 72 of the screw 66, located outside the anvil 46, is supported on the latter by means of elastic means constituted, for example, by a stack of Belleville washers 74. A washer 76 is advantageously interposed between the head 72 of the screw and Belleville washers 74. The arrangement is such that the axes of the screws 66 are oriented substantially radially relative to the axis of the basket.

In this embodiment, the internal clamping wedge 64, the connecting members constituted by the screws 66, as well as the elastic means constituted by the Belleville washers 74 form demountable fixing means of the cutting member 44.

Indeed, thanks to this arrangement, the cutting member 44 can be easily disassembled and replaced by exerting pressure on the head 72 of each of the screws 66. Under the effect of this pressure, the stack of washers Belleville 74 is compressed and the assembly constituted by the clamping wedge 64, the wear shoe 72 and the screws 66 is moved radially inwards by sliding along the rear flank 52. The clearance available to the screw 66 relative to the an anvil 46 is determined such that the clamping wedge 64 and the wear shoe 62 are then spaced from the front flank 50 of the recess 48 a sufficient distance to allow the extraction of the cutting member 44 out of the recessed portion 54.

Moreover, when the basket does not rotate, the elastic means, constituted in this case by the stack of Belleville washers 74, exert a sufficient force to hold the cutting member 44 in the recessed portion 54.

During operation of the machine involving the rotation of the basket 18 in the direction of the arrow F, the centrifugal force induced by this rotation is added to the force exerted by the elastic means to ensure effective maintenance of the cutting members.

As schematically illustrated in Figures 4A, 4B and 4C, the mounting of the cutting blade 58 on the blade holder 56 can be achieved in different ways, without departing from the scope of the invention.

Thus, as illustrated in FIG. 4A, the cutting blade 58 can be fixed on the blade holder 56 by one or more screws 78.

Alternatively and as shown in Figure 4B, the attachment of the blade 58 on the blade holder 56 can be provided by interlocking. For this purpose, the blade holder 56 may in particular have one or more protrusions 80 which are forcibly engaged in complementary housings 82 machined in the blade 58.

According to another variant, illustrated in Figure 4C, the attachment of the blade 58 to the blade holder 56 is provided by positioning fingers 84 which are force-fitted into holes 86 and 88 respectively machined in the blade holder 56 and in the blade 58.

Referring again to FIG. 2, it can be seen that the arrangement that has just been described makes it possible to break blocks 90 of an organic or synthetic material, such as wood chips or chips 92 of relatively small dimensions. . The chips or chips 92 are collected in the well 14 (Figure 1).

To facilitate the replacement of the cutters 44, a hatch (not shown) may be provided on the casing 26, in front of the cylindrical cutting portion 30 of the basket 18.

The supply channel 34 and the associated advance control means can also be mounted movably on the frame 10. A pivoting or sliding of the channel then allows to completely clear the basket 18. This can thus be replaced by another basket equipped for example with new cutting members or resharpened and adjusted.

In an improved embodiment, illustrated in FIG. 5, the machine, which is also identical to that just described with reference to FIGS. 1 to 4, makes it possible to further fragment the blocks of material 90.

In this improved embodiment of the invention, the rotating basket 18 has, outside the anvils 46, percussive irons 94 also oriented parallel to the axis of the basket. The number of hammers 94 is generally less than that of the anvils 46.

In addition, a static basket 96 is interposed between the rotating basket and the casing 26 (Figure 1) of the machine. This static basket 96 is fixed to the frame 10 of the machine, close to the percussive irons 94. It essentially comprises a cylindrical wall which alternately includes, in the circumferential direction, rasps 98 and calibration zones 100. The rasps 98 are turned inwards and the calibration zones 100 are formed for example of grids or perforated plates, so as to form passages of calibrated section.

When the machine is in operation, the chips or chips 92 formed outside the anvils 46 are rotated by the percussive irons 94 so as to be applied against the rasps 98 of the static basket 96. The fibers 102 thus formed cross the calibration areas 100 when their section is sufficiently small.

In this case, the fragmented products collected in the well 14 of the machine are no longer wafers or chips 92 as in the first embodiment described, but fibers of calibrated section 102, particularly suitable for use in the manufacture particle board or paper.

Of course, the invention is not limited to the embodiments which have just been described by way of examples. In particular, the orientation of the axis of rotation of the basket 18 as well as the number and orientation of the feed channels 34 may be substantially different from those described.

Thus, in a variant not shown, a bin having a horizontal axis, but whose rotational drive is performed at its periphery, can be associated with two feed channels entering the basket on either side of it and arranged substantially horizontally.

In another embodiment not shown, the axis of rotation of the basket can be vertical. In this case, several channels Inclined and descending feeds can open simultaneously inside the bin.

Claims (11)

1. Crushing machine (90) for blocks of natural or synthetic organic material such as wood, including a rotating basket (18) suitable for being drawn in rotation around an axis (20) by rotation control means (22); the said basket being equipped with cutting devices (44) which protrude towards the inside of the basket (18) and are directed substantially parallel to the said axis, the machine including at least one fixed channel (34) for feeding the blocks to be crushed, a first end of which is situated outside the basket, and a second end of which is placed inside the basket (18) and opens into the latter before the cutting devices (44), characterised in that it includes control means (36, 38) for feeding blocks (90) into the channel (34), designed to direct the said blocks to the cutting devices at a controlled and constant feed speed, and the feed control means (36, 38) include means for adjusting the said constant speed, including a lifting screw (36) housed in the channel (34), and a motor (38) for driving the said screw.
2. Machine according to claim 1, in which adjustment means, responsive to the energy absorbed by the rotation control means (22), pilot the feed control means (26, 38) in order to ensure substantially constant total energy consumption.
3. Machine according to any of the previous claims, in which the cutting devices (44) are fitted onto exterior anvils (46), integral with the basket (18), by demountable fixing means.
4. Machine according to claim 3, in which the fixing means include, for each cutting device (44), an interior taper wedge (64) suitable for applying the cutting device against the anvil (46), under the effect of the centrifugal force caused by a rotation of the basket, at least one connection device (66) linking the taper wedge (64) to the anvil (46) with a play which allows assembly and disassembly of the cutting device (44), and resilient means (74) which urge the taper wedge (64) towards the anvil (46), against the said play.
5. Machine according to claim 4, in which each connection device includes a screw (66) screwed into the taper wedge (64), freely crossing the anvil (46) and equipped with a disassembly head (72) accessible from the outside of the basket (18).
6. Machine according to any of the previous claims, in which each cutting device (44) includes a blade (58) fixed onto a blade holder (56).
7. Machine according to any of the previous claims, in which the channel (34) includes an emptying trap (35) in a part situated outside the basket (18).
8. Machine according to any of the previous claims, in which the channel (34) is movable in relation to the basket (18), so that it can be brought to a position of maintenance in which the channel (34) is situated totally outside the basket.
9. Machine according to any of the previous claims, in which the rotating basket (18) is mounted coaxially inside a static basket (96), one cylindrical wall of which includes, alternately, rasps (98) and sizing zones (100), and impact irons (94) fixed on the rotating basket (18) are fitted between the latter and the static basket (96), close to its cylindrical wall.
10. Machine according to any of the previous claims, in which the rotating basket (18) is surrounded by a fixed housing (26), which is provided with a trap giving access to the cutting devices (44).
11. Machine according to any of the previous claims, in which the axis of the rotating basket (18) is substantially horizontal, and an upwardly sloping single feed channel (34) opens out close to the upper generator of the said rotating basket.

Images