EP0396711A1

EP0396711A1 - Abrasion-type splitting unit

Info

Publication number: EP0396711A1
Application number: EP89912636A
Authority: EP
Inventors: François STRICOT
Original assignee: Trimex Silicon EURL; Photec Industrie SA
Current assignee: TRIMEX SILICON E.U.R.L.
Priority date: 1988-11-03
Filing date: 1989-10-27
Publication date: 1990-11-14
Also published as: WO1990005053A1; US5099820A; JPH03503266A; KR900701490A

Abstract

Unité de clivage par abrasion pour la découpe d'un lingot (143) de matériau dur en une pluralité de plaquettes. Cette unité comprend deux cylindres guide-fils (136, 137) identiques, horizontaux, parallèles, disposés en vis-à-vis et tournant en synchronisme, un fil (144) dévidé d'une bobine d'alimentation (139) puis enroulé sous tension autour des guide-fils pour former au moins une nappe de coupe avant d'être repris par une bobine de réception (148), et un actuateur (129) agissant selon un axe vertical (Z) passant par le centre de gravité du lingot (143) pour lever une console (119) supportant ce lingot et l'appliquer contre la nappe de coupe. Plus particulièrement cette unité comprend un bâti (102) monobloc symétrique par rapport au plan vertical médian, orthogonal aux guide-fils, le bâti présentant deux flasques latérales supérieures (111, 112) qui supportent de part et d'autre les guide-fils (136, 137) et comportant en sa partie inférieure des moyens de guidage (123) de la console (119) supportant le lingot (143).Abrasion cleavage unit for cutting an ingot (143) of hard material into a plurality of wafers. This unit comprises two identical, horizontal, parallel wire guide cylinders (136, 137), arranged opposite each other and rotating in synchronism, a wire (144) unwound from a supply spool (139) then wound under tension around the wire guides to form at least one cutting web before being taken up by a receiving spool (148), and an actuator (129) acting along a vertical axis (Z) passing through the center of gravity of the ingot (143) to lift a bracket (119) supporting this ingot and apply it against the cutting sheet. More particularly, this unit comprises a one-piece frame (102) symmetrical with respect to the median vertical plane, orthogonal to the thread guides, the frame having two upper lateral flanges (111, 112) which support the thread guides on either side ( 136, 137) and comprising in its lower part guide means (123) of the console (119) supporting the ingot (143).

Description

ABRASION DIVIDING UNIT

The present invention relates to an abrasion cleavage unit for cutting ingots of hard material. This invention relates more particularly to cutting machines used in the electronic or photovoltaic industry for cutting an ingot of silicon, germanium or glass into a multitude of fine wafers.

Such machines usually include at least two drums, also called wire guides, having on their cylindrical surfaces a series of circular grooves with the desired cutting pitch. These wire guides are arranged in a horizontal plane, and. this from the same vertical plane. A steel wire is wound around these wire guides which creates at least one horizontal cutting ply composed of a succession of strands of steel wires parallel to each other. Thus, this wire can be set in motion by the rotation of the wire guides. Furthermore, the cutting web is wetted with an abrasive liquid such as particles of silicon carbide suspended in water or oil. The ingot to be cut is pushed against the tablecloth in an underlying manner by a plate. The abrasive particles entrained by the liquid itself carried along by the wire then cause a cleavage or cutting effect.

Current research tends to optimize the quality of the cut obtained with industrial constraints. By cutting quality is meant a rigorous flatness and a minimum of mechanical stresses induced in the surfaces. Industrial considerations are for example the rate of wear of the wire, the possibility of recovering the abrasive and / or a high productivity such as 2,000 wafers per ingot of

80 cm. This optimum depends in fact on a combination of parameters such as the diameter of the wire which is of the order of 0.2 mm, the quality of the abrasive, the force of application of the ingot against the sheet currently fixed at approximately 50 g / line, the speed of movement of the wire established at approximately 3 m / s and the tension imposed on the wire, the preferred value of which is of the order of 2.5 kg (ie 26 N).

The cleavage units or cutting machines currently known usually comprise a vertical front plane from which emerges orthogonally, therefore horizontally forwards, two or three wire guide cylinders. On this same vertical plane are also arranged in various places a cutting wire delivery coil, a receiving coil and a wire tensioning device, for example using a lever arm, before winding around the wire guides. By way of example, mention may be made of the machines described in the disclosures US 3,478,732, US 3,525,324 and FR 2,254,948. In the latter example, the ingot to be cut is placed on an arm 60 also emerging from the plane vertical front. These wire guides and support plate being thus arranged in overhang, and taking into account the inherent elasticity of the steel composing them, the forces appearing between the cutting blade and the ingot during sawing are reflected in the wire guides and support arms and necessarily cause a deviation of these elements respectively to the right or to the left depending on the direction of movement of the wires.

In the machines described in the presentations FR 2 330 510 and US 4 640 259, the actuator moving the plate supporting the ingot acts along an axis passing through the center of gravity of this ingot. However, in these machines, the means for guiding the vertical axis of the actuator are still insufficient to avoid any vibration and / or bending of this arm, and therefore of the plate during sawing.

It is easy to understand that, by:

- serious faults in the choice of chassis technology,

- poor management of thread movement and tension,

- the incomplete system for moving the saw ingot,

- and the poorly adapted abrasive liquid distribution, this results in terms of cutting quality:

- scratches on the sawn faces,

- defects in parallelism between the faces of the same part,

- cylindrical-conical bulges of the sawn faces,

- wider cuts at the entry than at the exit of the wire.

as well as, in terms of industrial constraints:

- very long sawing times,

- a small number of pieces cut simultaneously,

- and a high operating cost.

In addition, the known cleavage units also fish: - by the absence of a device allowing the precise and necessary orientation of the axis of a crystalline ingot to cleave it by abrasion following the crystallization planes,

- by the absence of a precise analysis of the static and dynamic forces and constraints before and during sawing, making it possible to integrate these data into a procedure loaded in electronic and computer means automatically managing the movement of the various mobile elements of the cleavage unit.

The object of this invention is to solve the aforementioned problem by proposing an abrasion cleavage unit, in other words a cutting machine which allows, in particular:

- maintain the wires in their ideal position whatever the load conditions, thanks to rigorous stability of the wire guides,

- to organize a movement management device for the ingot to be sawn with 4 degrees of freedom while ensuring that the ingot is firm and precise in its position,

- record various important parameters during operation in order to manage and regulate them in relation to set points according to a specific ingot cutting procedure. In the following description, the direction "X" means that of the axis of the wire guides, direction "Y", the horizontal axis orthogonal to X, and the direction "Z", the vertical axis. In addition, vis-à-vis an observer standing in front of the machine, we mean by "posterior" a part of the machine oriented towards the observer, by "front" a part of the machine distant from the observer, therefore towards the rear, as well as "right" and "left" always in reference with respect to this same observer.

These aims are achieved by an abrasion cleavage unit for cutting an ingot of hard material into a plurality of plates which comprises at least two identical horizontal parallel wire guide cylinders arranged opposite and rotating in synchronism. ; a wire unwound from a supply coil and then wound under tension around the wire guides to form at least one cutting ply before being taken up by a receiving coil and an actuator acting along a vertical axis passing through the center of gravity of the ingot to lift a console supporting this ingot which it applies against the cutting table. More particularly, this cleavage unit comprises a one-piece frame symmetrical with respect to the median vertical plane orthogonal to the wire guides. This frame has two upper lateral flanges which support the thread guides on both sides. In addition, this frame comprises in its lower part means for guiding the console supporting the ingot.

Preferably, the console supporting the ingot has a square shape with its vertical plane oriented with respect to the frame. Then, the guide means comprise on each lateral edge of the vertical plane of the console at least one roller cage engaged in a vertical guide rail located correspondingly on the frame.

According to a first advantageous variant, the actuator is. a ball screw and nut driven by a DC motor with incremental encoder, this motor being controlled by electronic and computer means which manage the rise of the ingot according to a pre-established cutting procedure for the ingot.

According to another advantageous variant, the actuator is a hydraulic cylinder powered by a pump through a distributor controlled by electronic and computer means which manage the rise of the ingot according to a pre-established cutting procedure for the ingot. According to another advantageous variant, the actuator is a compressed air cylinder with a pressure variator controlled by electronic and computer means which manage the rise of the ingot according to a pre-established cutting procedure for the ingot, Usefully, the horizontal plane of the console in angle includes a sliding plate parallel to the axis X of the wire guides inside a groove made in the horizontal plane, and this thanks to roller guides. The horizontal plane also includes mechanical, electro-technical or hydraulic means for fixing the position of the platform in the horizontal plane of the console. These means for fixing the position of the plate may comprise a screw engaged through balls in a threaded orifice of the plate, which screw is driven by a geared motor which is controlled by electronic and computer means according to a pre-established cutting procedure for the ingot. .

Also usefully, the horizontal plane of the angled console includes a turntable with locking means in position for adjusting by rotation about the vertical axis Z the orientation of the axis of the ingot relative to the axis of the wire guides.

Also usefully, the horizontal plane of the angled console comprises a plate oscillating around a horizontal axis located under the ingot in the plane orthogonal to the cutting plane and parallel to the wire guides, which plate is driven by a gearmotor. - even controlled by electronic and computer means to print on the plateau oscillations of amplitude and frequency dependent on the pre-established cutting procedure for the ingot.

According to advantageous arrangements, the cleavage unit is completed by a device for extracting the cut ingot comprising at least one clamp, the two branches of which respectively bear a shell, the antagonist of identical shape in cylinder portion, which clamp is moved by a programmable robot. Advantageously also, the shells are provided on their outer faces with pins intended to be inserted into corresponding sockets located at the bottom of a washing tank in order to ensure the positioning and maintenance in this tank of the shells immobilizing during washing the cut ingot . This unit can also be completed by an initial device for placing the wire 144 on the wire guides.

It can also be useful for the cutting wire sheet to be soaked in abrasive liquor from below thanks to a longitudinal distributor at constant level. Also, it may prove useful that the ingot either cooled during cleavage by a longitudinal nozzle blowing cold air.

In other words, the invention is characterized by:

- a one-piece cast iron frame,

- a wire unwinding device upstream of the cut,

- a constraint generator,

- a device for winding the wire downstream from the cut, - a dispenser for abrasive cutting liquor,

- a wire wiping device,

- an air cooler to cool the ingot,

- an ingot extraction system at the end of the cut,

- an ingot washing system at the end of the cut,

- a system for placing the wafers on the transfer unit,

- a device for managing the movements of the saw ingot which has 4 degrees of freedom:

> a vertical movement system in Z of the ingot,

> an ingot oscillation system on its X axis,

> an ingot X translation system,

> an orientation system around Z of the ingot axis.

The invention is described below in more detail with the aid of an exemplary embodiment without limiting character illustrated in the accompanying drawings in which:

FIG. 1 represents a perspective view of a first embodiment of the molded frame provided for two wire guides with the vertical movement console Z and the horizontal movement plate X, FIG. 2 is a perspective diagram of the path of the cutting wire,

FIG. 3 is a detailed perspective view of the device for managing the orientation and movement of the ingot on the console,

FIGS. 4a and 4b are respectively perspective views and from the right side of the device for extracting the cut ingot,

FIG. 5 is a perspective view of the washing tub,

FIG. 6 is a perspective view of a second embodiment of the molded frame provided for four wire guides allowing the ingot to be cut to a larger size, and

FIG. 7 is a perspective view of the device for extracting the cut ingot specially designed for the cleavage unit illustrated in FIG. 6.

With reference to FIG. 1, the one-piece frame made of molded and stabilized GS cast iron is designed so that the deformations are very slight and entirely localized in the vertical planes containing the Y axis, therefore normal to the wire guides, so that the wires rigorously maintain their position along the X axis, substantially parallel to the axis of the ingot, throughout the cleavage cycle whatever the load conditions.

More particularly, the frame illustrated in FIG. 1 comprises in a single unit a horizontal base 1 from which four columns 2, 3, 15 and 16 leave from the front part. Columns 3 and 15 are connected together by a bridge 14. Columns 2 and 3 as well as 15 and 16 are respectively connected to each other by two side walls, their extension 11 and 12 constitute two side flanges. The term “flanges” is understood to mean parts going in pairs in a flat fashion and arranged in parallel serving to support an axis. The right lateral flange 12 has two circular orifices 5 and 7 whereas on the left lateral flange portion 11 is shown only the anterior circular orifice 4 in correspondence with the orifice 5. In the orifices 4 and 5 is provided d 'be installed the axis of a first anterior thread guide cylinder, the right end of the axis of the posterior thread guide being provided to be installed in the circular opening 7.

As can easily be understood, the fact that the frame is molded from a block from the base 1 to the flanges 11 and 12 provides the assembly with remarkable rigidity, in particular along the Y axis, that is to say parallel to the flanges, which happens to be the orientation of the action and the reaction between the wire guides and the ingot during cleavage. This rigidity is on the one hand due to the weight therefore to the inertia of the one-piece frame and on the other hand to its configuration, in particular the doubling of columns 2 and 3 as well as 16 and 15 along each lateral side. Referring to Figure 2, the metal wire

44 is unwound from a low voltage supply coil 39a. This wire passes through the force sensor 38a then into the wiping device 47a before being wound around the two wire guides 36 and 37. The wire 44 leaves the wire guides to leave in the wiping device 47c, then in the force sensor 38c before being taken up by a receiving coil 39c. Electronic and information means illustrated diagrammatically in FIG. 2 by lepided shields connected to one another by broken lines make it possible, from voltage measurements made by the sensors 38a and 38c, to manage the gearmotors 40a and 40c of the coils respectively. al imentation and reception as well as the geared motors 50 and 51 actuating the wire guides 36 and 37. By geared motors means the association of a motor, preferably electric, and a gearbox reducing the speed of rotation of the output shaft. According to the programs loaded in the computer means, these can for example generate a predetermined tension in the wires by controlling the flow rate and the recovery of the coils 39a and 39c as described in more detail in the description FR 2 254 948. The tension generator can also be formed from a cylinder not shown and pressing with a controlled pressure on the upper ply of wire. A distributor of cutting abrasive liquid 40 is in the form of a longitudinal tank flared upwards, filled with liquid fed from the bottom by means of a feed, not shown, and in an amount just sufficient for this liquid to emerge above the edges. anterior and posterior without overflowing. The distributor 40 is placed on the side of the wire guide 36 when the wire is unwound from the reel 39a towards the reel 39c.

The wire cleaning devices 47a and 47c can use a transverse or longitudinal compressed air jet in the middle of a venturi. These devices can also include one or more rollers filled with felt and turning in opposite direction to the direction of movement of the wire.

A longitudinal air nozzle, not shown, can be placed between the two wire guides in the middle of the sheets to permanently blow cold air against the ingot and thus cool it. This separate cooling device makes it possible to avoid the use of abrasive liquid as a cooling fluid, and therefore to minimize consumption, thereby reducing the operating costs of the machine.

The wire guides 36 and 37 are solid metal cylinders, the outer surface of which is coated with a non-stick layer of plastic or hard polymer such as that sold under the name VULCOLAN. In this outer surface is cut a series of side-by-side circular grooves, the pitch of which defines the thickness of the future plates. These grooves have, seen in cross section, a V shape oriented towards the inside of the cylinder. Referring to Figures 1 and 2, we see that the frame and the path of the wire 44 are rigorously symmetrical with respect to the vertical median plane orthogonal to the wire guides. This symmetry makes it possible to use the cutting wire moving indifferently in one direction or the other. In other words, the coil 39a alternately becomes the supply or reception coil and vice versa for the coil 39c. However, during each change of direction of travel, it is necessary to move the abrasive fluid supply device 40 near the wire guide 36 or 37. This symmetry in the architecture of the cleavage unit means that the action and reaction forces between the ingot and the cutting ply are distributed tangentially equally between the flanges 11 and 12.

The movement management device of the saw ingot manages four movements which can be linked together by mathematical functions in computer means and actuated separately or in synchronism by electronic and electro-technical means to generate particular cutting faces. This ingot movement management device comprises:

1. the movement along the vertical axis Z up and down,

2. the longitudinal movement of the ingot along the axis of

X parallel to the wire guides,

3. the rotation of the ingot around an underlying axis parallel to the X axis for oscillations,

4. rotation around the vertical axis Z for orientation of the axis of the ingot to be sawn with respect to that of the wire guides.

With reference to FIG. 1, the device for vertical up and down movement along the Z axis comprises a console 19, the vertical face 17 of which is mounted on the frame by two roller slides with pre-stressed mounting without play. The cages 21a, 21b and 22a (22b not visible) of the slides are secured to the lateral edges of the vertical face 17 and these cages slide on guide rails 23 and 24 secured to the columns and 2 and 16 of the frame. Vertical movement of the console

19 is produced by means of a screw and nut device balls 29 actuated by an incremental encoder motor 28 installed vertically between the base 1 of the frame and the underside of the horizontal face 18 of the console along a vertical axis Z passing through the center of gravity of the ingot. This rise force is measured continuously by electronic and computer means to be optionally regulated with respect to a set point which can be fixed or which can vary according to a mathematical function exploited by computer means.

This angled shape of the console 19 with its horizontal plane 18 and its vertical plane 17 makes it possible to keep the plate 18 strictly horizontal by effectively securing the vertical face 17 against and parallel to that of the material frame columns 2 and 16. This securing comprises on the left a guide rail 23 secured to column 2 and on the right a guide rail 24 secured to column 16. The vertical face 17 comprises a cage at its left lateral edge upper rollers 21a and a second lower 21b and at its right lateral edge in an identical manner an upper roller cage 22a and a lower cage not shown. When these roller cages are engaged in the rail of the corresponding frame, this securing only allows a vertical translation but prevents any deviation in particular by jamming in rotation around the orthogonal axis Y or by tilting of the plate towards the front is a rotation around of the lower edge of the plane 17. In addition, the thicknesses of the planes

18 and 17 are calculated so that the center of gravity of this console 19 is in the plane horizontal 18 at a point through which passes the vertical axis of action of the actuator 29 and where the ingot to be cut will also be arranged. In this way, the actuator 29 fully supports the weight of the console and no breakout force appears at the level of the roller cages 21 and 22.

Of course, the actuator 29 can also be a hydraulic cylinder powered by a pump through a distributor or a compressed air cylinder with pressure variator, these control members being in all cases controlled by electronic and computer means .

With reference to FIG. 3, the longitudinal movement device parallel to the axis X of the wire guides is produced by means of a plate 26 sliding inside a groove made in the horizontal plane 18. Preferably, this sliding of the plate 26 is produced by means of roller slides inserted between this plate and the console. The translational movement is produced by a bolt and nut with pre-stressed mounting without backlash driven by a geared motor 27. Of small amplitude, this movement along the X axis has the function on the one hand of adjusting if necessary longitudinal position of the ingot and on the other hand to perform a lateral cut at the end of cleavage to separate the laminated ingot from its support. Of course, such movements printed by the geared motor 27 are controlled by electronic and computer means according to the procedure specific to the ingot. On the plate 26 described previously is. installed a second oscillation device making it possible to give the ingot a rotary movement centered on a horizontal axis situated under the ingot in the median orthogonal plane of the cutting ply. This device comprises a first plate 30, the upper surface of which is curved into a portion of a convex cylinder, on which a second plate 31 is disposed in the lower face is convex complementary to that of the upper of the plate 30. This plate 31 can be moved thanks to a gear motor 42 back and forth along the arc of the cylindrical joint. This device can be used to oscillate the ingot 43 back and forth with a predetermined amplitude and frequency making it possible to control the contact arc in the wire and the ingot and at the same time perform a fine grinding of the faces of the parts of the fact that these wires cross-saw during this oscillation. Still with reference to FIG. 3, the device for managing the movement of the block comprises, above the elements described above, a device for orienting the longitudinal axis of the ingot relative to the axis of the wire guides, and this by a more or less significant rotation about the vertical axis Z. This device comprises a base 32 with in its center a pivot penetrating into a circular orifice formed in correspondence in the underside of the pivoting plate 33. This device is also provided with means angular measurement and locking means in its new position of the pivoting plate 33 on the base 32. This possibility of orientation of the ingot axis by compared to that of the wire guides is necessary to make the plane of crystallization of the ingot and the vertical plane of cutting by the web co-planar.

With reference to FIGS. 4, the cleavage unit is also completed with a device for extracting the cut ingot. This device comprises two opposing shells 70, 73 having a shape in the form of a cylinder of diameter identical to that of the ingot to be removed. The front shell 70 is held by two arms 68 and 79 to a tube 61 movable in rotation about an axis 66. The rear shell 73 is held on the right by an arm 77 to a cylinder 63 located above the tube 61 and on the left by an arm 84 to a cylinder 65 also located above the tube 61. These tubes 63 and 65 are only movable in rotation relative to the tube 61. On the left side, a pin 83 orthogonal and integral with the axis 66 crosses respectively helical grooves 64 of the tube 61 and 82 of the cylinder 65. Similarly on the right side, a pin 81 orthogonal and integral with the axis 66 respectively crosses a helical groove 62 of the tube 61 and a helical groove 80 of the cylinder 63 Thus, when the axis 66 is moved in translation by the gear motor 60, the tube 61 and the cylinders 63, 65 being prevented in this translational movement by means not shown, the respective displacement of the pins 81 and. 83 in the grooves force the separation or the bringing together of the opposing shells 70,73. Thus, it is possible to control at will the setting or the release of the ingot 43 by this extraction device. Two end pads 67 and 78 allow this assembly to be moved by rails not shown. The external face of the shells 70 and 73 is also provided with pins oriented downwards 71a, b and c. In relation to sockets 91 located at the bottom of a washing tank 90 as illustrated in FIG. 5, these pins allow these shells 70,73 containing the ingot cut at the bottom of the washing tank to be held in position once that the arms 68, 77, 79 and 84 are separated from the shells. It is then possible to wash the cut ingot, that is to say to remove between the plates the pasty residues which appeared during sawing. In this tank 90, the washing solvent can be circulated by a pump starting from the top of the ingot now laminated, this solvent causing the mixture of sawdust and abrasive product to run off which is deposited at the bottom of tank 90 where the solvent is taken up by the circulation pump. This washing unit can also be provided with another handling automaton taking the cleaned platelets one by one from the tank and placing them on a transfer mat for successive treatments.

FIG. 6 illustrates a machine tool produced according to the invention and intended for cutting large ingot 143, that is to say a length of the order of 800 mm for a diameter of 200 mm. In such ingots it is possible to cut approximately 2,000 wafers simultaneously. However, it will be readily understood that the action and reaction forces between the cutting web and the ingot are significantly increased. In addition, to provide sufficient space for the ingot during the sawing operation, four wire guides should be provided.

136,137,138 and 139 around which the cutting wire 144. is wound. The one-piece frame of this machine comprises a base 101, two side walls 102 supported at the top by two crosspieces 114 and 115 and having respectively two side flanges 111 and 112. In the left side f lasque 111 are formed the openings provided for the axes of the wire guides

104, 106, 108 and 110 and in the right flange 112 the thread guide pin holes 103, 105, 107 and 109.

The cutting wire leaves a supply coil 139 to first pass through a tension damping device 146 before entering the interior of the frame where it is tensioned before being wound around the wire guides. There is a similar device on the right side of the machine up to the take-up reel 148. As before, the front face of the frame is completed on either side by two rails 123 and 124. The console 119 in the form of a square as before comprises a horizontal plane 118 and a vertical plane 117 held against the guide rails 123 and 124 by roller cages of which only those on the left side 121 are visible. This console 119 is moved vertically by the underlying actuator 129.

Given the dimensions of this cutting machine, it may prove useful to also provide an initial device for placing the cutting wire on the wire guides, of which only the upper part 160 is illustrated for better clarity of the figure. This device can comprise a rail of generally square shape with rounded angles on the inner face of which a carriage turns. This substantially square rail is arranged perpendicularly around the wire guides and it is moved in translation along these wire guides by dess means not shown. Either the carriage carries a coil of wire which it unwinds, or it only holds the end of the wire and the wire guides must be rotated during installation to directly unwind the coil 139. In Figure 7 is illustrated the device for extracting the ingot 143 cut specially provided for the machine illustrated in FIG. 6. This device comprises an automaton mounted on a cross member 198 coming on top of the frame, this automaton comprising means 194 for vertical movement, means 192 for translation along the X axis and an arm 190 which can rotate around the V axis. At the end of this arm 190 is located a clamp device 161 each branch of which respectively carries a shell in the form of a portion of cylinder 170 and 173 apprehending the ingot. Means make it possible to turn this clamp around the axis W. As previously, these shells 170 and 173 have means such as pins making it possible to fix them securely to the bottom of the washing tub. Given the dimensions and the geometry of this frame, it is possible to simultaneously cut numerous plates in a single ingot and this without any vibration or deflection ensuring an appreciated quality for the resulting plates in particular in flatness and absence of induced mechanical stresses. The management of this machine by electronic and computer means makes it possible to follow the smooth running of the sawing operation at all times and this with a reduced staff. Its high yield also makes it an appreciated machine from an economic point of view. Many improvements can be made to this cleavage unit in the context of this invention.

Claims

1. Abrasion cleavage unit for cutting an ingot (143) of hard material into a plurality of plates comprising at least two identical guide cylinders (136,137), horizontal, parallel, arranged opposite and rotating in synchronism, a wire (144) unwound from a supply reel (139) then wound under tension around the wire guides to form at least one cutting ply before being taken up by a receiving reel (148) , and an actuator (129) acting along a vertical axis (Z) passing through the center of gravity of the ingot (143) to lift a console (119) supporting this ingot and apply it against the cutting web, characterized in that it comprises a monobloc frame (102) symmetrical with respect to the median vertical plane, orthogonal to the wire guides, the frame having two upper lateral flanges (111,112) which support the wire guides (136,137) on both sides and comprising its lower part of the guide means (123) of the console (119) supporting the ingot (143).

2. Cleavage unit according to claim 1, characterized in that the console (119) supporting the ingot (143) has a square shape having its vertical plane (117) oriented with respect to the frame, and in that that the guide means comprise on each lateral edge of the vertical plane (117) of the console (119) at least one roller cage (121) engaged in a vertical guide rail (123) located correspondingly on the frame.

3. Cleavage unit according to claim 1, characterized in that the actuator (129) consists of a ball screw and nut driven by a DC motor with incremental encoder, this motor being controlled by electronic and computer means which manage the rise of the ingot according to a pre-established ingot cutting procedure for the ingot.

4. Cleavage unit according to claim 1, characterized in that the actuator (129) consists of a hydraulic cylinder supplied by a pump through a distributor controlled by electronic and computer means which manage the rise of the ingot according to a pre-established cutting procedure for the ingot.

5. Cleavage unit according to claim 1, characterized in that the actuator (129) consists of a compressed air cylinder with a pressure variator controlled by electronic and computer means which manage the rise of the ingot according to a pre-established cutting procedure for the ingot.

6. Cleavage unit according to claim 1, characterized in that the horizontal plane (18) of the bracket console (19) comprises a plate (26) sliding parallel to the axis of the wire guides inside d '' a groove formed in the horizontal plane (18), and this by means of roller slides, as well as mechanical, electro-technical or hydraulic means to fix the position of the plate (26) in the horizontal plane (18) of the console.

7. Cleavage unit according to claim 6, characterized in that the means for fixing the position of the plate (26) in the horizontal plane (18) of the console (19) comprise a screw engaged through balls in a threaded orifice of the plate (26) and driven by a geared motor (27) which is controlled by electronic and computer means according to a pre-established cutting procedure for the ingot.

8. Cleavage unit according to claim 1, characterized in that the horizontal plane (18) of the bracket console (19) comprises a turntable (32,33) with means for locking in position allowing adjustment by rotation around from the vertical axis (Z) the orientation of the axis of the ingot relative to the axis of the wire guides.

9. Cleavage unit according to claim 1, characterized in that the horizontal plane (18) of the bracket console (19) comprises a swash plate (30,31) around a horizontal axis located under the ingot in the plane median orthogonal to the cutting plane and parallel to the wire guides, which plate is driven by a geared motor (42) itself controlled by electronic and computer means to print on the plate (30,31) oscillations of amplitude and frequency dependent on the pre-established cutting procedure for the ingot.

10. Cleavage unit according to claim 1, characterized in that it is completed by a device for extracting the cut ingot comprising at least one clamp (161,61 / 68/84), the two branches of which carry respectively a shell the antagonist (70 / 73,170 / 173) of identical shape in portion of cylinder, which clamp is moved by a programmable automaton (190/192/194/198).

11. Cleavage unit according to claim 10, characterized in that the shells (70 / 73,170 / 173) are provided on their outer faces with pins (71) intended to be inserted in the corresponding bushings (91) located at the bottom of 'a washing tank (90) in order to ensure the positioning and maintenance in this tank of. shells (70 / 73,170 / 173) immobilizing the ingot (43) cut during washing.

12. Cleavage unit according to claim 1, characterized in that the cutting wire sheet (44) is soaked in abrasive liquor from below thanks to a distributor (40) longitudinal at constant level.

13. Cleavage unit according to claim 1, characterized in that the ingot (43) is cooled during cleavage by a longitudinal nozzle blowing cold air.

14. Cleavage unit according to claim 1, characterized in that it is supplemented by a device (160) for initial positioning of the wire 144 on the wire guides.