FR2787362A1 - Band saw for cutting metals has saw head mounted on support attached to front of base frame - Google Patents

Abstract

The metal cutting band saw has a working head including the saw and its drive which is movable as an assembly. The assembly is mounted on support (2) in front of the rigid frame forming the base (3) and above the work discharge feed (5). A feed (4) passes bar stock into the saw and the discharge feed removes the cut work.

Description

METAL SAWING DEVICE BY SAW BAND

  The invention relates to a device for sawing metals by saw bands, of the type comprising a mobile working assembly comprising the saw band and its drive device, a means for advancing the metal bars under said mobile assembly with a view to sawing them, and a means of removing the shavings

sawing.

  The document EP 313.429 AI describes a band sawing machine comprising, facing the location provided for the workpiece, a mobile working assembly which comprises the saw band and its drive device. The speed of movement of the movable assembly in the direction of the workpiece is braked by a hydraulic circuit comprising a valve capable of limiting or interrupting the flow of the flow. A control member provided opposite this valve is associated with the actuation of the saw band drive flywheel, so as to act on the valve of the hydraulic braking circuit during an increase in resistance opposing the torque. saw tape drive. An increase in this resistance thus causes a limitation of the flow rate in the hydraulic braking circuit and consequently a reduction in the speed of movement of

the mobile working assembly.

  This device is entirely satisfactory, but has the drawback of a force transmission from the mobile working assembly to the guide columns of the machine. Because the mobile working assembly has a wide opening intended for the passage of the saw bars, the tension of the ribbon produces a stress and a deformation of the mobile working material which are transferred to the columns of

  guide which is detrimental to the regulation of the advance of the saw band.

  In addition, given that the center of gravity of the mobile working assembly is located substantially at the center of this opening, the force applied by the displacement cylinder of the mobile working assembly, offset relative to said opening,

  generates a load imbalance on the bearings of the guide columns.

  Finally, in this known machine, the evacuation of the chips is carried out inside the frame of the machine: this arrangement is penalizing for the evacuation

shavings.

  The object of the invention is to remedy the drawbacks of the known technique, by proposing a new device for sawing metals by saw bands which is simple and economical to manufacture, having good robustness and excellent productivity. The subject of the invention is a device for sawing metals using a saw band, of the type comprising: a mobile assembly comprising the saw band and its drive device, a means for advancing the metal bars under said movable assembly in view of their sawing, and a means of evacuation of the sawing chips, characterized in that the device comprises a rigid frame comprising a base on which is disposed the means for advancing the metal bars, as well as at least one support for mobile working assembly so as to support the mobile working assembly in front of said base in the direction of advance of the metals and

  above the sawdust removal means.

  According to other characteristics of the invention: - said base comprises a concrete block poured into a formwork of which said mobile assembly support is integral, - the rigid frame comprises two spaced uprights supporting a means of displacement of the mobile assembly and at least one means for guiding said mobile assembly in its movement, - a first upright carries a guide column and a displacement cylinder for moving the mobile assembly, and a second upright carries a slide without load transfer preventing the rotation of the movable assembly around said guide column, - movable assembly carries a motorized pulley for driving the saw band, movably mounted with its motor under the action of a means of tensioning the saw band, - the means for advancing bar metals is associated with a bar holding vice during sawing and comprises a bar advancing vice. The bar holding vice during sawing is placed near the mobile working assembly, so as to minimize the end of the bars falling, - the mobile working assembly carries two clamps for guiding the saw band, the spacing of which is adjustable as a function of the spacing of the jaws of the bar for retaining the bars during sawing, - the center of gravity of the mobile working assembly is located substantially on the axis of its displacement cylinder, so as to avoid any undesirable transmission of load detrimental to the regulation of the movement of the mobile working assembly, - the means for advancing the metal bars is associated with a holding vice substantially symmetrical with respect to the cutting plane corresponding to the descent of the ribbon saw, - the chip evacuation means comprises a chip elevation conveyor for dumping into a receiving tank and a means for recovering the cutting lubricant.

  The invention will be better understood thanks to the description which will follow given to

  by way of nonlimiting example with reference to the accompanying drawings in which: - Figure 1 schematically shows a perspective view illustrating the general principle of a device according to the invention, - Figure 2 schematically shows a perspective view and in elevation of a device frame according to the invention, - Figure 3 schematically shows a rear perspective view of a device according to the invention comprising a frame of the kind shown in Figure 2, - Figure 4 schematically shows a view in perspective and in

  front elevation of the device of FIG. 3.

  - Figure 5 shows schematically a rear perspective view of a chip evacuation means for device according to the invention, - Figure 6 shows schematically a front elevation view of a

  device according to the invention equipped with the chip evacuation means of FIG. 5.

  Referring to Figure 1, a device for sawing metals according to the invention comprises a mobile working assembly 1 supported by at least one support 2 secured to a base 3. The base 3 and the support 2 are rigidly connected between them to constitute the frame of the device. A means for advancing metal bars comprises a fixed vice 4a for holding the bars during sawing and a movable vice 4b for advancing the bars. The clamps 4a and 4b are arranged on the base 3 of the rigid frame. A means of evacuation 5 of the chips generated during sawing of metals into

  bars is arranged below the mobile working assembly 1.

  Thus, after having mounted a metal bar B in the clamps 4a, 4b, so as to advance the bar B in successive steps thanks to the movable vice 4b movable in the direction of the arrow 6, the saw band is driven in the direction of arrow 7 thanks to a motor 8 and suitable flywheels. The descent of the mobile working assembly 1 in the direction of arrow 9 makes it possible to saw the bar B, to evacuate sections in the direction of arrow 10 and to recover the metal shavings falling by gravity in the direction of arrow 11 for their evacuation

  final or recycling in the direction of arrow 12.

  Due to the fact that the mobile assembly 1 is supported by the support 2, and that the center of gravity of the mobile assembly 1 for work is located near this support 2, any undesirable transmission of load or effort harmful to the regulation of movement in the direction of arrow 9 of the mobile working assembly 1 In addition, the modular mounting of the device provides easy access to the mobile assembly 1 of

  work for the possible replacement of the saw band.

  Economically, the base 3 is produced by pouring a reinforced concrete block into a metal formwork to which the support 2 of the mobile assembly 1 is attached. With reference to FIG. 2, a preferred embodiment of the invention comprises a frame formed by assembling sheets forming at the bottom a formwork capable of receiving concrete to form a base block which ensures rigidity

of the frame.

  The use of concrete to form the base block makes it possible to move backwards and to lower the center of gravity of the device according to the invention. The frame is made up of two substantially vertical uprights 13, 14 spaced apart by a distance allowing the installation of a vice for holding the barrens to be sawed. A first upright 13 carries a column 15 for guiding a mobile assembly, not shown, mounted on two bearings 16, 17 for vertical guide. The second upright 14 carries a plate 18 capable of forming a slide without load transfer, so as to prevent the rotation of the mobile assembly 1 around the guide column 15. Two side walls 19a, 19b are fixed respectively to the uprights 13 and 14 to form reinforcement gussets These walls 19a. l9bfQmnt in the lower part of the sides of the formwork of the concrete base and in the upper part of the protective walls surrounding the space reserved for the movement of a movable vice in advance of the

metal bars for sawing.

  A front wall 20 secured to the vertical uprights 13 and 14 and a possible rear wall 21 ensure the closure of the two other sides of the casing of the concrete base. An upper crosspiece 22 connects the vertical uprights 13 and 14 and a beam 23 intended to receive a holding vice not shown is rigidly fixed to the vertical uprights 13 and 14. The vertical plane passing through the middle of the beam 23 overhangs an empty space in before the vertical uprights 13 and 14,

  space capable of receiving a means, not shown, for evacuating saw shavings.

  Des1pids 1l3a and angle brackets 24 allow prior adjustment and planing, the assembly of the sheets before pouring the concrete. These comières 24 and these feet 13a are trapped in the concrete block after setting, they allow the

fixing to the ground of the assembly.

  Lifting holes 25a, 25b are provided for handling the device in the event that the device is to be moved after pouring the concrete block

forming a base.

  The rigid frame thus formed is undeformable due to the bonding of the concrete

  reinforced on the walls of the formwork and the uprights 13 and 14.

  A removable protective plate 26 may be provided above the concrete block, and preferably has a slope for discharging the cutting oil, slope

  preferably made by folding and stiffening ribs of the plate 26.

  With reference to FIGS. 3 and 4, the elements identical or functionally equivalent to the elements in FIG. 2 are identified by reference numbers

  identical to the figures in figure 2.

  The metal bars are brought in by a conveyor 27 mounted on a rear cross member 28 secured to the concrete base and carrying a vice 29 movable in advance by successive steps capable of being opened and closed by an actuating cylinder 30. The mobile assembly 31 shown without its protective cover comprises a pulley or flywheel 32 for driving the saw band motorized by a motor 33, preferably a hollow shaft gearmotor. The flywheel 32 and its motor 33 are movably mounted in the movable assembly 31, in order to tension the saw band by means of tensioning mnyen 34 in the vertical vertical plane

saw tape.

  The tensioning system of the saw blade is placed near the flywheel 32 and the motor 33, so as to arrange the center of gravity as a whole

  mobile 31 on the axis of its displacement cylinder 35.

  The mobile assembly 31 can thus be moved on its guide bearings 16 and 17 along the column 15 under the action of this displacement cylinder 35 mounted at

  proximity to the guide column 15.

  The column 15 is integral with the vertical upright 13 in three points positioned so as to add to the rigidity of the gtdage. while n tends to decrease the

column diameter 15.

  As the center of gravity of the mobile working assembly 31 is arranged, when the saw band is under tension, on the axis of the cylinder 35 for moving and controlling the movement of the mobile assembly 31, no parasitic load, nor any carrier overhang is transmitted to the rigid frame, so that any effort and any deformation liable to affect the sensitivity of the regulation of the advance of the saw band are eliminated. In addition, because the movable working assembly 31 is substantially symmetrical with respect to the vertical cutting plane passing through the vertical part 36 of the saw band, no parasitic deformation is generated during sawing, nor in this

  vertical plane or in another plane.

  The mobile working assembly comprises a support structure 37 carrying at one end the movable motorized flywheel 32 and at the other end the free flywheel 38

  in rotation ensuring the return of the saw band.

  The support structure 37 co-supports two plates carrying two metric rolling bearings of the free flywheel 38. The flywheel 32 is also mounted on

  two rolling bearings similarly arranged.

  The supporting structure 37 is mounted on the side of the free flywheel 38 so as to slide on the plate 18 forming a flat slide by means of pads.

  slip not shown enclosing this flat slide 18.

  The saw band runs horizontally on the pulleys or flywheels 32, 38 and is subjected to a twist applied by straightening and guiding tongs for the band.

  saw, so as to straighten it vertically on the active cutting section 36.

  Preferably a straightening and guiding clamp 39a is mounted directly on the structure 37, while the other clamp 39b is slidably mounted on a movable plate 39c mounted by prismatic ball slides on the structure 37. These prismatic slides u bills can descend in the low position near the movable jaws 42 of a holding vise 40, for a

greater rigidity.

  The supporting structure 37 is preferably made from two parallel plates symmetrical with respect to the vertical section plane corresponding to the section 36 of saw band. The holding vise 40 is preferably produced from two parts which are also symmetrical with respect to the vertical plane passing through the section 36, so as to present on each side of the metal bars to be sawed a fixed jaw 41 and a movable jaw 42. The movement of the movable jaws 42 is controlled by a

  displacement and tightening cylinder 43.

  It follows from this arrangement that the bars to be sawed are perfectly maintained on either side of the ribbon which passes between the jaws 41 and the jaws 42 during sawing. In addition, the movement of the clamp 39b can be controlled by the movement of the jaws 42, for example mechanically by action on a stop 44 integral

pine oo39b.

  Advantageously, the uprights 13 and 14 are carded by a distance sufficient for the jaws of the vice 29 in advance of the bars to slide until they are in close proximity to the jaws 41 and 42 of the retaining clamp 40: thus, the losses

  due to falling end bars are minimized.

  The space included under the member 34 for tensioning the saw band advantageously receives a device for continuously cleaning the saw band by simple or double brushing, with the optional addition of a system not shown of

  cleaning and cooling of the ribbon by jets of pressurized lubricant.

  Due to the clearance of space included under the beam 23 and the continuous slit provided on either side of the vertical section plane corresponding to the section

  36, the establishment of a chip evacuation means is very easy.

  Advantageously, an elevation conveyor of the type shown in FIG. 5 is used as the means for evacuating the shavings, comprising a lubricant separation means with a settling tank 44 and a filtration assembly 45

  i5s the lubricant recovered in the tank 46 is continued.

  In FIG. 6, a device according to the invention is shown equipped with a chip evacuation means comprising a conveyor of the type of that of FIG. 5 with squeegees 47 containing an elevation device motorized by a motor 48 and a discharge orifice 49 in a chip bin 50. The arrows 51, 52 indicate the direction of discharge of the chips by gravity respectively during the

sawing and after conveying.

  The invention described with reference to a particular embodiment is in no way limited thereto but covers any modification of form and any variant of embodiment within the scope and spirit of the invention. The main thing is that the device according to the invention is designed to be mounted at the front of a rigid frame, so as to allow natural evacuation of the chips by gravity, according to an arrangement preventing the transmission of forces to the frame, so as to avoid transmission

  unwanted load to the regulatory bodies of the device.

Claims (10)

  1. Device for sawing metals by saw bands, of the type comprising: a mobile working assembly (1, 31) comprising the saw band and its drive device (8, 32, 33, 38); means (4b, 29) for advancing the metal bars under said movable assembly (1, 31) for sawing; and a means of evacuation (5, 47-49) of the sawdust, characterized in that the device comprises a rigid frame comprising a base (3, 20, 21) on which the means (4b, 29) is disposed for advancing the metal bars as well as at least one support (2, 13, 15) of the mobile working assembly (1, 31), so as to support the mobile working assembly (1, 31) in front of said base (3, 20, 21) in the direction of advance of the metals and above the evacuation means (5, 47) of the saw shavings. 2. Device according to claim 1, characterized in that said base (3) comprises a concrete block poured into a formwork (20, 21) of which said said is integral   mobile assembly support (2, 13, 15).   3. Device according to claim 1 or claim 2, characterized in that the rigid frame comprises two spaced uprights (13, 14) supporting a means (35) for movement (9) of the movable assembly (1, 31) and at least one guide means (16-18) of said movable assembly in its movement 4. Device according to claim 3, characterized in that a first upright (13) carries a column (15) for guiding and a jack (35) for moving the movable assembly (1, 31), and a second upright (14 ) carries a slide (18) without load transfer preventing rotation of the mobile assembly (1, 31) around said column (15) guide.   5. Device according to any one of the preceding claims,   characterized in that the movable assembly (1, 31) carries a motorized pulley (32) for driving the saw band, movably mounted with its motor (33)   under the action of a means (34) for tensioning the saw band.   6. Device according to any one of the preceding claims,   characterized in that the means (4b, 29) for advancing the metals on barroes is aSooié with a vice (4a, 40) for holding the bars during sawing and comprises a vice (4b, 29) for advancing the bars, and in that the holding vice (4a, 40) of the bars during sawing is placed near the mobile working assembly (1, 31), so as to   minimize falling end of bars.   7. Device according to Claim 6, characterized in that the mobile working assembly (1, 31) carries two clamps (39a, 39b) for guiding the saw band, the spacing of which is adjustable as a function of the spacing jaws (41) of the vice (40) of bars maintained during sawing.   8. Device according to any one of the preceding claims,   characterized in that the center of gravity of the mobile working assembly (1, 31) is situated substantially on the axis of its actuator (35d displacement, so as to avoid any undesirable transmission of load detrimental to the regulation of the displacement of   the mobile working assembly (1, 31).   9. Device according to any one of the preceding claims,   characterized in that the means (4b, 29) for advancing the metal bars is associated with a vice (40) for holding substantially symmetrical with respect to the cutting plane   corresponding to the descent of the saw strip (36).   10. Device according to any one of the preceding claims,   characterized in that the chip evacuation means comprises a conveyor (48) for raising the chips with a view to discharging them into a receiving tank (50)   and means (44-46) for recovering the cutting lubricant.