Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
  • B23Q35/00—Control systems or devices for copying directly from a pattern or a master model; Devices for use in copying manually
  • B23Q35/04—Control systems or devices for copying directly from a pattern or a master model; Devices for use in copying manually using a feeler or the like travelling along the outline of the pattern, model or drawing; Feelers, patterns, or models therefor
  • B23Q35/08—Means for transforming movement of the feeler or the like into feed movement of tool or work
  • B23Q35/10—Means for transforming movement of the feeler or the like into feed movement of tool or work mechanically only
  • B23Q35/101—Means for transforming movement of the feeler or the like into feed movement of tool or work mechanically only with a pattern composed of one or more lines used simultaneously for one tool
  • B23Q35/102—Means for transforming movement of the feeler or the like into feed movement of tool or work mechanically only with a pattern composed of one or more lines used simultaneously for one tool of one line
  • B23Q35/104—Means for transforming movement of the feeler or the like into feed movement of tool or work mechanically only with a pattern composed of one or more lines used simultaneously for one tool of one line with coaxial tool and feeler

Definitions

• the invention relates to a method and a device for machining a workpiece by removing or discharging material using at least one tool, according to which said workpiece or each tool is subjected to a rotational movement around an axe.
• a machining process is in particular implemented by means of conventional lathes (simple, to copy, with numerical control ...) whose design allows the manufacture of parts of revolution or helical shape ( thread).
• Such towers are particularly suitable for the manufacture of mechanical parts but offer little latitude in generating forms for decorative purposes.
• the invention aims to overcome this drawback and to provide a process allowing, on an industrial or artisanal scale, the production of parts which may have a wide variety of shapes.
• the invention relates to a machining process by removing or discharging material, according to which: - each tool is moved longitudinally along an axis parallel to the axis of rotation,
• each tool is moved transversely simultaneously along an axis orthogonal to the axis of rotation, - and in combination with these longitudinal and transverse displacements, the part and each tool are moved in translation relatively relative to each other along an axis parallel to the axis of rotation so as to give one of them an alternating axial movement of variable amplitude synchronized with the rotation of the part.
• Such a method allows continuous machining of a workpiece during which it is moved to will and in three dimensions (rotation, longitudinal displacement, transverse displacement) the shape of this part, with a variable inclination of the patterns depending on the amplitude of the axial reciprocating movement.
• the tool is moved longitudinally along the workpiece without being physically connected to any system, while also being animated with a transverse movement intended to vary its position. transverse relative to the axis of rotation.
• the latter (or the workpiece) is driven by an alternating translational movement of variable amplitude making it possible to produce various patterns whose inclination is a function of said amplitude.
• the machining can be carried out in a conventional manner, in particular for woodworking, using any type of tool, (simple tool, form tool, strawberry).
• the method according to the invention consists in varying the amplitude of the reciprocating movement so that the latter is inversely proportional to the distance between the tool and the axis of rotation, and is zero for a virtual position of the tool on the axis of rotation.
• An application of this embodiment advantageously aims at making creeping balusters intended to form the uprights of a stair railing. Indeed, such a method makes it possible to very easily produce the lower and upper faces of these balusters so that the latter have an inclination equivalent to that of the staircase, and facilitate assembly.
• the invention consists in rotating said three-dimensional template with a speed of rotation equal to the speed of rotation of the workpiece.
• This technique advantageously makes it possible to produce parts, such as balusters, of section other than circular.
• the invention extends to objects produced according to the method described above and to a device for machining a part by removing or discharging material by means of at least one tool, comprising means for holding the part. to machine, and means drive in rotation about an axis of said holding means or of each tool.
• this machining device comprises: means of longitudinal displacement of each tool along an axis parallel to the axis of rotation,
• a machining device intended for the manufacture of parts on an industrial scale, and in which the means for driving in rotation are associated with the means for holding the part to to machine:
• the longitudinal displacement means comprise a longitudinal carriage and means for driving in translation of said carriage able to move it parallel to the axis of rotation by giving it, during this longitudinal displacement, an axial reciprocating translation movement of amplitude variable synchronized with the speed of rotation of the holding means,
• the transverse displacement means comprise a transverse carriage carrying a tool and mounted on the longitudinal carriage, and means for driving in translation of said transverse carriage relative to said longitudinal carriage along an axis orthogonal to the axis of rotation.
• the longitudinal carriage is moved in translation by integrating, during from this displacement, the axial reciprocating movement.
• a machining device therefore requires only two sets of translation of the tool, longitudinal and transverse, and its production simply requires numerically controlling the rotation of the holding means and the longitudinal movement of the tool so as to synchronize these movements.
• an additional numerical control assigned to the movement of the transverse carriage can in particular make it possible to vary the amplitude of the reciprocating movement as a function of the transverse position of the tool so as, for example, to machine portions of flat surface.
• this machining device comprises a tool holder block fixed in translation relative to the transverse carriage, and means for pivoting said tool holder block around an axis, called vertical, orthogonal to longitudinal and transverse axes of movement.
• This arrangement makes it possible to modify the orientation of the tool, for example by means of a numerical control, and therefore multiplies the variety of achievable shapes.
• the means for longitudinal displacement comprise a longitudinal carriage and means for driving said carriage in translation along an axis parallel to the axis of rotation,
• the transverse displacement means comprise a transverse carriage mounted on the longitudinal carriage and means for translational driving of said transverse carriage relative to said longitudinal carriage along an axis orthogonal to the axis of rotation,
• the means of displacement in translation relative of the holding means and of the tool comprise a tool-carrying carriage mounted on the transverse carriage and means of translational drive of said tool-carrying carriage relative to said transverse carriage capable of moving it parallel to the axis of rotation with an alternating movement of variable amplitude synchronized with the speed of rotation.
• this second embodiment includes an additional translation assembly due to the fact that the longitudinal displacement and the reciprocating movement are obtained by means of two different carriages.
• the inertia problems during changes of alternation are less significant because only the relatively light tool trolley is subjected to reciprocating motion.
• the machining device advantageously comprises, for one or the other version described above, a sanding assembly provided with a sanding tool and offset longitudinally relative to the machining assembly, said assembly sanding comprising:
• Such a sanding assembly allows, by numerically controlling displacements of the sanding tool similar to those of the machining tool, carry out, by means of a single device, the machining of the parts then the finishing of the latter.
• this sanding assembly preferably comprises means for pivoting the sanding tool about an axis orthogonal to the axes of longitudinal and transverse movement.
• the means of which for driving the holding means in rotation comprise a motor shaft
• the means for moving in relative translation of said holding means and of the tool comprise: a ring disposed around the motor shaft, articulated on a frame by means of pivots adapted to allow it to pivot relative to the motor shaft around an axis perpendicular to the longitudinal axis of said drive shaft, means for tilting the ring around its pivot axis,
• the guide member advantageously consists of a yoke of conjugate width of the diameter of the section of the ring, said yoke being carried by a pivot so as to be able to pivot about an axis perpendicular to the longitudinal axis of the drive shaft.
• such a yoke has the advantage of constantly expanding orthogonally with respect to one of the axes of symmetry of the circular section of the ring, thus ensuring perfect guidance of the latter.
• this guide member can be mounted:
• the means for tilting the ring comprise a lever secured to one of the pivots, and means for pivoting said lever.
• pivoting means can, moreover, be of any conventional type and consist, for example, of:
• the axis of rotation of the device described above can be either horizontal (main application: wood lathe), or vertical (main application: potter's lathe).
• the means for pivoting the lever are controlled by means for recording the position of the tool relative to the axis of rotation. of the motor shaft, and are adapted to vary the inclination of said lever as a function of the transverse position of the tool, so that the amplitude of the reciprocating movement is inversely proportional to the distance between the tool and the axis of rotation, and be zero for a virtual position of the tool on said axis of rotation.
• the lever is advantageously provided with a longitudinal light and associated with pivoting means comprising a jack whose state is controlled by the means for reading the transverse position of the tool, said jack comprising:
• FIG. 1 is a perspective view of a first embodiment representing a wood lathe according to the invention with manual adjustment
• FIG. 2 is a vertical section through an axial plane A of this wood lathe
• FIG. 3 is a vertical section through a transverse plane B
• Figure 4 is a block diagram showing the various controls with which the device according to the invention can be fitted
• Figure 5 is a longitudinal view of an object produced by means of a device according to the invention
• FIG. 6 is a perspective view of a second embodiment representing a wood lathe according to the invention for the production of objects provided in particular with inclined plane faces, such as balusters,
• FIG. 7 is a block diagram of the operation of the adjustment means of the device shown in FIG. 6,
• FIG. 8a represents an object as produced by means of the device represented in FIG. 6, from a model represented in FIG. 8b.
• Figure 9 is a partial cross section of a third embodiment of a wood lathe as shown in Figures 1 and 6,.
• FIG. 10 is a longitudinal section through a plane C, on an enlarged scale, of this embodiment,
• FIG. 11 is a schematic transverse view of a fourth embodiment of a machining device according to the invention.
• Figure 12 is a partial perspective view of a fifth embodiment of a machining device according to the invention consisting of a variant of that shown in Figure 11,.
• FIG. 13 is a diagram illustrating the forms of machining obtained on a part for various speed curves imparted to the reciprocating displacement means.
• machining devices shown in Figures 1 and 6 consist of wood lathes of specific design allowing the production of parts that can have a wide variety of shapes.
• the device shown in FIG. 1 is a device with manual adjustment of which only the part for driving in rotation and for holding the part 1 to be machined has been shown.
• the machining tool part can be of any type known per se and consist for example, either of a simple actuated tool and maintained manually, more conventionally e a tool-holder trolley set in motion manually by means of a handwheel, or automatically by means of a turning bar or a lead screw.
• This device comprises, first of all, a frame 2 on which are mounted two bearings 3, 4 housing a rotation shaft 5.
• This rotation shaft 5 carries, towards one of its ends, a mandrel 6 for holding the part 1 to be machined, and, towards its opposite end, a drive pulley
• This frame 2 also comprises two longitudinal flanges 9, 10 extending symmetrically on either side of the rotation shaft 5.
• the means, in accordance with the invention, for moving the rotation shaft 5 in an axial reciprocating movement comprise a ring 11 of circular section arranged concentrically around said rotation shaft (by section of the ring 11 is meant to define the cross section of said ring in a radial direction).
• This ring 11 carries two external pivots 12, 13 diametrically opposite, adapted, one to be housed in an orifice with a horizontal axis formed in one of the flanges 9, and the other to extend through an orifice. formed in the other flange 10, coaxial with the aforementioned orifice of the first flange 9.
• the means associated with this ring 11, intended to allow its pivoting comprise, first of all, a lever 14 integral with the pivot 13.
• This lever 14 forms a yoke 14a housing a nut 15 articulated inside said yoke so as to be able to pivot about an axis parallel to the pivot axis of the ring 11.
• pivoting means include, also, a worm 16 associated with conventional rotational drive means 17, actuated by means of a crank 18, and integral with the frame 2, said worm being adapted to cooperate with the nut 15 so as to bring lever 14 to pivot.
• the means for moving the rotation shaft 5 in a reciprocating motion further comprises a guide member 19 integral with said rotation shaft 5, and having the shape of a yoke of width combined with the diameter of the section of the ring 11, adapted to accommodate said ring during the rotation of said guide member.
• this guide member 19 is mounted in line with two diametrically opposite flats 20, 21, formed on the rotation shaft 5.
• this guide member 19 is mounted on a stud 22 provided with a stop head 22a preventing the escape of said guide member, said stud being housed in a through orifice formed in the rotation shaft 5, orthogonally to the flats 20, 21, and being provided with one end threaded on which is screwed a counterweight 23 diametrically opposite to the guide member 19.
• This guide member 19 comprises, firstly, a ring 24 of diameter adapted to be mounted around the stud 22 so as to be able to rotate around the latter.
• This ring 24 disposed between the head 22a of the stud and the flat 20 facing the rotation shaft 5, has two lateral extensions 25, 26 diametrically opposite, each pierced with a bore, giving said ring a cross-section T shape.
• the guide member 19 further comprises two studs 27, 28 each housed in an orifice of an extension 25, 26 of the ring 24.
• each guide member mounted around each of the studs, between the head 27a, 28a of the latter and the corresponding extension 25, 26, each guide member comprises a bearing such as 29, and a spacer 30 disposed between the bearing 29 and said extension.
• each stud 27, 28 relative to the ring 24 is ensured by a nut such as 31.
• the device described above makes it possible to produce asymmetrical pieces of revolution 32 such as, for example, that shown as example in Figure 5, comprising from right to left with reference to the figure: a first section having a symmetry of revolution obtained by positioning the ring 11 orthogonally to the axis of rotation (zero amplitude), a second section 32b having an asymmetry of revolution, obtained by tilting the ring 11 in a first direction of pivoting relative to the vertical, and a third section 32 obtained by tilting the ring 11 in a direction opposite to the first.
• the movable headstock (not shown) of the wood lathe described above can be: - fixed, and carry an axis of length greater than the maximum amplitude of the axial movement, said axis being intended to be housed in an axial bore formed in the workpiece,
• the wood lathe described above can, in addition, as shown diagrammatically in FIG. 4, be equipped with one or the other or all of the options defined in this figure, in order to allow a digital control of one or more movements.
• a) the speed of rotation of the rotary shaft 5 can be controlled by means of a stepping motor
• b) the speed of movement of the tool 33 can be controlled by a stepping motor
• c) the inclination of the lever 14 and therefore the ring 11, determining the amplitude of the reciprocating movement can be controlled by means of a stepping motor
• d) the transverse position of the tool 33 relative to the axis of rotation can be controlled by means of a stepping motor
• e) the orientation of the tool 33 can be controlled by a motor gearbox
• f) the speed of rotation of the tool 33 (milling cutter, etc.), depending in particular on the diameter of this tool, the nature of the material to be machined, etc. can be controlled by means of a step motor step by step. All of these commands allow
• the device shown in Figure 6 is, in turn, particularly suitable for making, by copying, objects having in particular flat faces inclined relative to their longitudinal axis, such as for example balusters.
• This device is in accordance with that of FIG. 1 as regards the ring 11 and the guide member 19 associated with the latter. It differs on the other hand at the level of the means associated with the ring 11 in order to cause the latter to pivot.
• These means are, in fact, designed to be controlled by the position of a probe (not shown) in contact with a template to be copied, adapted so that the angle of inclination of the ring 11 is a function of the position of the tool relative to the axis of rotation of the shaft 5.
• These means for controlling the inclination of the ring 11 comprise, first of all, a lever 35 integral with the pivot 13 and provided with a longitudinal light 36. They are adapted to vary the inclination of this lever 35 so that the amplitude of the reciprocating movement axial of the rotation shaft 15 is inversely proportional to the distance between the tool and the axis of rotation, (given by the position of the probe on its gauge) and is zero for a virtual position of said tool on said axis of rotation .
• control means comprise a jack 37, the state of which, deployed or retracted, is controlled by the position of the probe.
• the rod 37a of this jack 37 carries a finger 38 housed in the opening 36 of the lever 35, and is associated with guide means (not shown) capable of absorbing the lateral forces.
• the body 37b of this jack 37 is, in turn, secured to a positioning lever 39 carried by a pivot 40 rotatably mounted in a bearing 41 integral with the frame 2, and arranged so that said pivot is coaxial with the finger 38 in the deployed position of the jack 37.
• this positioning lever 39 Towards its end opposite to the pivot 40, this positioning lever 39 comprises a pin 42 housed in a graduated opening 43 formed in a plate secured to the frame, said opening having a curvature centered on the axis of rotation of the pivot 40.
• this pin 42 can be replaced by a control system identical to the nut / worm / crank system such as that shown in FIG. 1 under the references 15, 16, 18 in which, in addition, the crank can be replaced by a stepper motor).
• the jack 37 is adapted so that its stroke is proportional or equal to the transverse movement of the tool.
• the lever 35 is in its position of minimum inclination when the jack 37 is deployed, state corresponding to an axial movement of zero amplitude. Conversely, the lever 35 is in its position of maximum inclination when the jack 37 is retracted, state corresponding to an axial movement maximum amplitude for a given inclination of the positioning lever 39.
• the inclination of the jack 37 can also be adjusted as a function of the position of the pin 42 in the lumen 43, the inclination of the face of the part produced being likewise determined as a function of this setting.
• FIG. 8a represents an object 44 produced by means of the device described above, by copying from a model 45 as shown in FIG. 8b.
• each plane face of the model 45 orthogonal to the longitudinal axis of the latter leads to the production of a plane face, inclined by the preset angle by means of the pin 42.
• Figures 9 and 10 represent a variant of the machining devices described above, according to which the pivots 12, 13 of the ring 11 are mounted in bearings, such as 46, secured to a movable ring 47 centered on the axis of rotation and rotatably mounted inside a fixed concentric ring 48, secured to the frame 2 thanks to the interposition of a ball cage 49 between said rings.
• the movable crown 47 includes a sidewall provided with an annular rack 50.
• a gear motor or a stepping motor 51 equipped with a forward and reverse gear is fixed on the side of the fixed crown 48 so that its rotation shaft extends radially.
• This geared motor 51 carries a pinion 52 arranged to mesh with the rack 50.
• This arrangement makes it possible to rotate the movable crown 47 and therefore the ring 11 around the axis of rotation, making it possible to obtain an offset from zero to 90 degrees of the plane of symmetry of the workpiece and therefore of the patterns produced.
• Figure 11 shows schematically a machining device according to the invention whose frame 53 is only very partially shown, with a machining assembly and a sanding assembly, more specifically designed for the production of parts on an industrial scale.
• the means for holding the workpieces and for driving them in rotation are conventional means equipping in particular the current numerically controlled towers and are therefore neither described in detail nor shown in this figure.
• the machining device is adapted to move laterally with respect to the frame 53 and comprises a first longitudinal carriage 54 provided with two superimposed rows of rollers 55, 56 arranged to frame and come to roll along two horizontal guide rails 57, 58 secured to the frame.
• This longitudinal carriage 54 is equipped with a numerically controlled motor 59 provided with a pinion 60 meshing with a rack 61 fixed on the underside of the upper guide rail 57.
• This machining device further comprises a transverse carriage 62, of the type for example linear ball screw carriage, equipped with a numerically controlled motor 63, carried by the longitudinal carriage 54, and on which a device is mounted angle gear 64 with vertical output shaft, actuated by a numerically controlled motor 65.
• This machining device further comprises a tool holder block 66 mounted on the output shaft of the bevel gear 64, so as to be able to pivot around a vertical axis.
• this device comprises a tool consisting of a cutter 67 driven by a motor 68 whose rotation shaft 69 is held and guided inside a horizontal bore formed in the tool holder block 66.
• the As for its sanding device it is similar in principle to the machining device and is suitable for moving over the frame 53. This sanding device is, moreover, offset longitudinally with respect to the machining device.
• It comprises a longitudinal carriage 70 provided with two parallel rows of rollers 71, 72 with a vertical axis framing and rolling along two rails 73, 74 secured to a horizontal longitudinal wall of the frame
• This longitudinal carriage 70 is equipped with a numerically controlled motor 75 provided with a pinion 76 meshing with a rack 77 secured to a side of one of the guide rails 74.
• This sanding device also comprises a transverse carriage 78, for example of the linear ball screw carriage type, equipped with a numerically controlled motor 79, the carriage body 80 of which is integral with the longitudinal carriage 70, so that the columns 81 of said carriage extend vertically and slide inside said carriage body.
• transverse carriage 78 On this transverse carriage 78 is also mounted an angle transmission device 82 with a horizontal output shaft, actuated by a numerically controlled motor 83, with which the sanding block 84 is associated.
• the reciprocating movement imparted to the cutter 67 and to the sanding block 84 is integrated into the longitudinal movement of the longitudinal carriages 54, 70, and these longitudinal movements are therefore synchronized with the rotation of the workpiece digitally controlled to this effect.
• FIG. 12 represents a variant of the device described above according to which the axial reciprocating movement is dissociated from the longitudinal displacement.
• the tool holder block 85a 85a is mounted on the carriage body 86 of a linear carriage 87 itself mounted on a transverse carriage, shown diagrammatically at 88, this linear carriage 87 conventionally comprising two columns such as 89 s extending between two spacers such as 90, and the aforementioned carriage body 86 provided with ball bushings.
• this linear carriage 87 includes a numerically controlled motor 91 actuating a ball screw 92, and adapted to synchronize the movements of the carriage body 86 with the rotation of the workpiece.
• such machining devices make it possible in particular to modify the profile of the machining according to the acceleration and deceleration curves of the speed V of alternative displacement imparted to tools 67, 85a, these curves possibly evolve between theoretical extreme shapes, respectively triangular and rectangular (for half-wave displacement), with a classic sinusoidal intermediate shape.
• machining devices make it possible to produce parts having several planes of symmetry by subjecting the tool to an alternating movement whose frequency is a multiple of the speed of rotation of the part to be machined.

Landscapes

• Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Mechanical Engineering (AREA)
• Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Milling, Drilling, And Turning Of Wood (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9465561

Family Applications (1)

Country Status (4)

Family Cites Families (6)

• 1994
  • 1994-07-18 FR FR9408957A patent/FR2722439B1/fr not_active Expired - Fee Related
• 1995
  • 1995-07-17 WO PCT/FR1995/000950 patent/WO1996002354A1/fr not_active Application Discontinuation
  • 1995-07-17 EP EP95925890A patent/EP0771247A1/de not_active Withdrawn
  • 1995-07-17 CA CA002193696A patent/CA2193696A1/fr not_active Abandoned

Non-Patent Citations (1)

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