FR2563132A1 - Boring head - Google Patents

Abstract

The present invention relates to a boring head. Boring head characterised in that it is essentially composed of a body 1 mounted on a support 2 which is equipped with a fastening tail, which is cylindrical of modular or other type, or of a tail which can be fitted directly to the machines, or of a tail with attachment to the Morse taper cone or to the American taper cone, or even with a TR threaded tail, or the like, to which it is rigidly fixed by an assembly screw 3, by a device 4 for indexing in all positions of the body 1 relative to the support 2, and by an assembly 5 for the support and adjustable movement of the cutting tool 6 in the direction perpendicular to the axis of the body 1.

Description

 The present invention relates to the field of machining by boring on conventional or numerically controlled machines, on machining centers or by means of flexible workshop equipment, and relates to a boring head.

 According to the invention, the boring head is essentially constituted by a body mounted on a support provided with a fixing tail, by a screw for assembling the body with the support, by a device for indexing the body by relative to the support, and by a set of support and adjustable displacement of the cutting tool perpendicular to the axis of the body.

 The invention will be better understood thanks to the description below, which relates to preferred embodiments, given by way of nonlimiting examples, and explained with reference to the appended schematic drawings, in which FIG. 1 is a view in side elevation and partially in section of a boring head according to the invention; Figure 2 is a sectional view along A-A of Figure 1 Figure 3 is a view similar to that of Figure 1 of an alternative embodiment of the invention; Figure 4 is a plan view and partially in section along Figure 3 Figure 5 is a front elevational view according to Figure 3 Figure 6 is a plan view of an alternative embodiment of the body of the head bore according to Figure 1 Figure 7 is an elevational view from the rear according to Figure 6 Figure 8 is a side elevational view according to Figure 6 Figure 9 is a view similar to that of Figure 8 of a alternative embodiment of the mounting of the body FIG. 10 is a front elevation view of a fixing base FIG. 11 is a plan view, partially in section of the sole. FIG. 12 is a sectional view along BB of the figure. Figure 13 is a front elevational view of an alternative embodiment of the sole Figure 14 is a front elevational view of an alternative embodiment of a body Figure 15 is a sectional view along CC of the Figure 14 Figure 16 is a sectional view along DD of the f FIG. 14 FIG. 17 is a view similar to FIG. 14 of another alternative embodiment of the body, and FIG. 18 is a view in partial section along F of FIG. 17.

 According to the invention, and as shown more particularly, by way of example, Figures 1 and 2 of the accompanying drawings, the boring head is essentially constituted by a body 1 mounted on a support 2 to which it is rigidly fixed by a connecting screw 3, by a device 4 for indexing in all positions of the body I relative to the support 2, and by a set 5 of support and adjustable movement of the cutting tool 6 in a direction perpendicular to the body axis 1.

 The support 2 is provided with a fixing tail, cylindrical of the modular type or other (case of the figure), or a tail adaptable directly on the machines, or a tail with attachment to the Morse cone or to the American cone , or a TR threaded tail, or other.

 The device 4 for indexing the body 1 relative to the support 2 is constituted by a cylindrical stud 7 secured to the support 2 and capable of cooperating with holes 8 of corresponding diameter arranged at regular intervals on the rear face of the body 1, these holes 8 advantageously being twelve in number and offset by 30. This indexing mode allows adjustment of the angular position of the tool 6 in the best position, to within 150, when the spindle stops, to start or end the machining operations.

 Indexing can also be carried out by providing friction zones between the body 1 and the support 2, notches, teeth, or the like.

 The assembly 5 of support and adjustable displacement of the tool 6 is constituted by a piston 9 mounted to slide with very tight tolerances in a bore extending perpendicular to the axis of the body 1 near its front end, and actuated by means of a fine pitch micrometric screw 10, which, on the one hand, is provided with a wide head 11 with inclined flank, the center of which is provided with a hexagon for operating, and whose inclined flank has graduations cooperating with graduations provided on a flat 12 of the body 1, and, on the other hand, cooperates with a nut 13 secured to the piston 9 by bonding, a needle screw 14 ensuring its final tightening, this nut 13 being positioned in the piston 9 by means of a stop 15 simultaneously closing the cavity of the nut opposite the screw 10 as well as a threaded hole used for fixing a tool holder 16 of the tool 6 in the form of a plate to the by means of a screw 17 and a washer 18.

 Thanks to the graduations provided on the micrometric screw 10 and on the flat part 12 of the body 1, it is possible to perfectly control the advance of the piston 9 and therefore of the tool 6, for example from 0.01 mm to the diameter.

 The nut 13 is not mounted tight so as not to undergo any deformation during its introduction into the piston 9, and the stop 15 serves, on the one hand, to support the nut 13, and, on the other hand, to avoid any entry of foreign body into the nut 13 and possible deterioration of the micrometric thread by such a body.

 The screw 10 is held in the body 1 by a resilient segment 19 fixed in a groove in the bore of the body 1, by a lock nut 20, and by a spacer 21, the thickness of which is slightly greater. than that of segment 19 in order to allow mounting clearance for screw 10 reduced to a minimum. According to an alternative embodiment of the invention, not shown # in the accompanying drawings, in order to avoid any operating clearance, a compressible washer of the Belleville type is inserted during mounting between the elastic segment 19 and the underside of the head of the screw 10, with prior compression, preferably two-thirds, the thickness of the spacer 21 then being equal to that of the segment 19 increased by that of the compressed washer.

 Maintaining and guiding the piston 9 in its bore is ensured by a conical groove 22 provided along a generator and cooperating with a rectified needle 23 with a conical end, the application pressure in the groove 22 is adjusted by means a screw 24, a second screw 24 'glued in the thread ensuring the inviolability of the adjustment, and by a screw 25 for locking the piston in position, which rests on a flat 25' of the piston 9.

 Thus, the displacement of the piston 9 can be perfectly controlled without the possibility of circular movement and its locking in position is ensured by the screw 25.

 The lubrication of the piston in its bore is carried out by means of a lubricator 26 whose outlet orifice is advantageously tangent to the bore at the level of the axis of the body 1, so that a small space is formed allowing the lubrication of the assembly.

 At its free end, the piston 9 is provided with a groove 27 for housing the insert holder 16, which is kept applied during work against a clearance 28 provided in the free end of the body 1.

 The insert holder 16 # can be fixed and centered in the piston 9, in any other way, namely by cross-centering, or the like, and all types of insert can be mounted on said insert holder 16.

 According to an alternative embodiment of the invention, not shown in the accompanying drawings, the piston 9 can also be provided with a longitudinal clearance extending along a generator, provided with the footprint of the micrometric screw 10 , and intended to cooperate with the latter, which then has a larger diameter and extends tangentially to the piston 9.

 According to another alternative embodiment of the invention not shown, the piston 9 is in the form of a dovetail piece, a polygonal piece, or a toothed or grooved profile, the screw 10 cooperating with a nut fixed on the upper part of the piston.

 According to another alternative embodiment of the invention, and as shown in Figures 3 to 5 of the accompanying drawings, for roughing work, the boring head is constituted by a body 29 having at its rear part a tail of attachment, or the like, and at its front part an open housing having sides which are advantageously slightly inclined while widening in the direction of the tail, or sides parallel to the axis provided with grooves, or rectified guide teeth, or the like , by insert holders 30 and 31 housed in an adjustable manner in position in the body 29, by a screw for locking the insert holders 30 and 31 between the sides of the housing cooperating with a threaded hole 32 on one side of said housing and passing through the other side as well as a transverse groove of the insert holders, and by a device 33 for adjusting the insert holders.

 Such a boring head does not require indexing because it works with two tools, but must be more robust than the head described above. Similarly, the precision of the adjustment may be less, but the two insert holders must be able to be adjusted separately.

 To this end, the device 33 for adjusting the wafer holders 30 and 31 is constituted by two pins 34, 34 'each secured to a wafer holder 30 and 31 and penetrating through two parallel grooves 35 and 36 in two threaded holes 37 passing through the body 29 right through, one of the grooves 36 being open at one end (FIG. 5), and the other groove 35 being closed, and the transverse extension of said grooves is defined by the adjustment length of the insert holders 30 and 31, and by two pairs of screws 38 engaged in the threaded holes 37 in order to actuate the pins 34 and 34 'in displacement from the two sides of the holes 37.

 The closed groove 35 is provided for the insertion of the first wafer holder 30 by the front face of the body 29, while the other groove 36 is intended to allow mounting of the second wafer holder 31 by simple lateral interlocking.

 The housing of the body 29 has, in known manner, at its bottom, along the sides, clearances intended to promote the machining of its walls.

 As soon as the adjustment of the insert holders 30 and 31 is carried out, the locking screw is tightened in the hole 32 so as to pinch said insert holders, and the screws 38 are then applied on both sides against the rods 34 and 34 'respectively, holding the insert holders 30 and 31 perfectly in position.

 Of course, the movement of the wafer holders can also be carried out in other ways, for example by means of screws cooperating directly with the wafer holders, or the like.

 At its front part, the body 29 has on each side a clearance 39 allowing an easy evacuation of the chips, as well as an orifice 40 for the arrival of cooling lubricant, which arrives through channels 41 connected to a rear central channel 42 Other arrangements of the lubrication channels are possible, in particular with the arrival of the lubricant at the bottom of the housing and passage through the insert holders, or else an ejection of the lubricant through a transverse hole perpendicular to the axis of the body, etc.

 According to another characteristic of the invention, a third insert holder, not shown, can be mounted in place of one of the first two insert holders 30 and 31 and have a tool offset longitudinally relative to the other tool in order to produce a delayed cut and a division of the width of the chips. Thus, a better distribution of the cutting force is obtained, and the central lubrication improves the ejection and evacuation of the chips.

 Such a design of a rough bore head makes it possible to obtain a great robustness of said head as well as a simple and easy adjustment and an effective tightening of the insert holders.

 For the production of large bore diameters, the bore head is constituted, as shown in FIGS. 6 to 13 of the appended drawings), by a body 43 of identical design to that of the body 1 according to FIGS. 1 and 2 in as regards the adjustments, the piston 9, the fixing and the holders, by a sole 44 (FIGS. 10 to 13) for fixing and guiding the body 43 by means of screws 46, mounted with the possibility of indexing on a attachment (not shown), and by a device 45 for guided movement of the body 43.

 The sole 44 is provided with a bore 47 for centering on a corresponding hub with an attachment, known per se, this attachment being provided, moreover, with holes spaced regularly over a diameter and intended to cooperate with screws 48 for the fixing and indexing of the sole 44. The holes of the attachment will advantageously be spaced between them by 300.

 The sole 44 is provided on its face turned towards the body 43 with a longitudinal tongue 49 (FIG. 11) intended to cooperate with a corresponding centering groove 50 of the body 43, and allowing guided movement of said body 43 on the sole 44.

 The device 45 for guided movement of the body 43 consists of a driver 51 having two parallel flats (FIG. 6) and fixed in the body 43, in the axis of the groove 50, by a nut 52 provided with a transverse groove 53 intended to cooperate with the coach 51, guided in translation in a groove 54 of the sole 44, and driven by an adjustment screw 55, which is subjected in translation by a groove and ball mounting 56, and guided to its other end in a housing 57 of the sole.

 Maintaining and guiding the movement of the body 43 on the sole 44, during adjustment, is further ensured by two pins 58 slidably mounted in two holes 59 drilled in the body 43 and extending parallel to the groove of centering 50, these holes being connected to the application face of the body 43 on the sole 44 each by a groove 60 for the passage of the fixing screws 46, which are screwed into threaded holes 61 extending perpendicular to the axis of the rods 58, which have over their entire length, on the side of the screws 46 a flat 58 'and the holes 59 are closed, after mounting of the rods 58, by plugs glued in recesses 59' provided at their ends.

 Between the threaded holes 61 is provided an additional threaded hole 62 oriented in the same direction as the holes 61, but preferably of smaller diameter, into which two screws 63 and 64 penetrate, one of which, 63, cooperates with a groove 65 of the body 43 and prevents the rotation of the corresponding rod 58 in its housing and forms a stop for the movement of the body 43 on the sole 44, while the other, 64, facing the sole 44, exceeds the face corresponding to the body 43 and cooperates with a corresponding groove 66 of the sole 44 for positioning the body 43 on said sole 44 during assembly, so that the threaded holes 61 of the pins 58 are aligned with those 67 and 67 'of the sole 44 (Figure 10).

 Thanks to this constitution, two modes of movement can be provided for the tool, namely a rapid movement by means of the adjustment screw 55 placed in the sole 44, and a # micrometric movement by means of the screw actuating the piston 9. The movement of the body 43 is only authorized after a slight loosening of the screws 46 for mounting and blocking the body 43 on the sole 44. During movements and adjustments of the body 43, only the latter is moved relative to the remaining space available in the holes 59 of the rods 58.

 The end stops for movement of the body 43 are formed, on the one hand, by the head of the screw 55, and, on the other hand, by the end of the groove 60, which cooperate in the extreme positions, respectively with the nut 52 and with a screw 46.

 The sole 44 is provided with at least two sets of nut 52 - adjustment screw 55 and holes for mounting and locking screws 46.

 The attachment of the sole to its attachment could also be achieved by a dovetail, by rectified toothing, or other. Similarly, the guidance of the body 43 on the sole 44 could be achieved by other centering and guiding means.

 For operations of finishing large bores, carried out with a single finishing head, a counterweight is advantageously fixed on the other side of the sole 44 by means of the free holes for the mounting and locking screws.

 In the case of boring heads of average diameter not allowing a fixing of the body 43 directly on the sole 44 by means of the screws 46, due to the size of the attachment, two screws 68 are provided (FIG. 9 ) having a part 68 'provided with a thread penetrating into a hole 61 of a rod 58 and a male part 68 "penetrating into a bore of the part 68' turned towards the sole 44, this part 68" being retained in its bore by a groove and ball connection 69 allowing pivoting of the part 68 "after tightening of the part 68 'in the rod 58 by means of two flats 70 of the part 68', and the part 68" is provided, near its free end of a conical hole 71, perpendicular to its axis, and into which enters a conical screw 72 fixed in the sole 44 and whose axis is offset from that of the hole 71, and in the extension of the hole 71 is fixed, with a slight offset towards the body 43, a lug 73 allowing the centering of the base d e the screw 68 during its introduction into the corresponding hole 67 of the sole 44 (FIG. 10) by cooperation with a groove 74 of the said hole 67.

 Thus, when the conical end of the screw 72 enters the hole 71, the fixing screw 68 'is tightened in the sole 44.

 Figures 14 to 18 show another alternative embodiment of the invention, in which the body is in the form of an intermediate support block 75 (Figures 14 to 16) or an upper support block 76 (Figures 17 and 18) , the intermediate block 75 being fixedly adjustable on the sole 44, centered on the latter by means of a groove 77, and provided with threaded holes 78 for receiving the fixing screws of the upper block 76, which is guided on the block intermediate 75 by means of a tongue 79 cooperating with a groove 80 of said block 75, and which is provided with two additional housings of fixing screws allowing additional movement of the block 76 on the block 75.

 Heads conforming to those described above are particularly intended for large diameter rough bores and the head forming the upper block 76 uses commercially available cartridges 81 as platelet support, generally fixed by means of a biased thread. 82, and bearing on perpendicular faces 83 and 84, a screw 85 being provided for fine adjustment, from the rear.

 The fixing and adjustment of the block-shaped bodies 75 and 76 on the sole 44 are identical to those of the bodies 29 and 43, but their design is clearly simplified.

 Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements, or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (21)

- CLAIMS  1. Boring head, characterized in that it is essentially constituted by a body (1) mounted on a support (2) which is provided with a fixing tail, cylindrical of the modular or other type, or a tail adaptable directly on the machines, or a tail with attachment to the Morse taper or to the American cone, or also a threaded tail TR, or other, to which it is rigidly fixed by a connecting screw (3), by a device (4) for indexing the body (1) in all positions relative to the support (2), and by an assembly (5) for support and adjustable movement of the cutting tool (6) in a direction perpendicular to the axis of the body (1).  2. Boring head according to claim 1, characterized in that the device (4) for indexing the body (1) relative to the support (2) consists of a cylindrical stud (7) integral with the support (2 ) and able to cooperate with holes (8) of corresponding diameter arranged at regular intervals on the rear face of the body (1), these holes (8) being advantageously twelve in number and offset by 300.  3. Boring head according to claim 2, characterized in that the indexing can also be carried out by providing friction zones between the body (1) and the support (2), notches, teeth, or other .  4. Boring head according to claim 1, characterized in that the assembly (5) for support and adjustable displacement of the tool (6) consists of a piston (9) mounted to slide with very tight tolerances in a bore extending perpendicular to the axis of the body (1) near its front end, and actuated by means of a fine pitch micrometric screw 10, which, on the one hand, is provided with a wide head (11) with an inclined flank, the center of which is provided with an operating hexagon socket, and the inclined flank of which has graduations cooperating with graduations provided on a flat (12) of the body (1), and, on the other hand, cooperates with a nut (13) secured to the piston (9) by bonding, a needle screw (14) ensuring its final tightening, this nut (13) being positioned in the piston (9) by means of a stop ( 15) simultaneously closing the cavity of the nut opposite the screw (10) and a threaded hole used for fixing a tool holder (16) of the tool (6) in the form of plate by means of a screw (17) and a washer (18).  5. Bore head according to claim 4, characterized in that the maintenance of the screw (10) in the body (1) is ensured by an elastic segment (19) fixed in a groove in the bore of the body ( 1), by a lock nut (20), and by a spacer (21), the thickness of which is slightly greater than that of the segment (19).  6. Boring head according to claim 4, characterized in that in order to avoid any operating clearance, a compressible washer of the Belleville type is inserted during mounting between the elastic segment (19) and the underside of the head of the screw (10), with prior compression, preferably two-thirds, the thickness of the spacer (21) then being equal to that of the segment (19) increased by that of the compressed washer.  7. Boring head according to claim 4, characterized in that the maintenance and guiding of the piston (9) in its bore are ensured by a conical groove (22) provided along a generator and cooperating with a needle rectified (23) with conical end, the application pressure in the groove (22) is adjusted by means of a screw (24), a second screw (24 ') glued in the thread ensuring the inviolability of the adjustment, and by a screw (25) for locking the piston in position, which rests on a flat (25 ') of the piston (9).  8. Boring head according to any one of claims 4 and 7, characterized in that at its free end, the piston (9) is provided with a groove  (27) housing the insert holder (16), which is kept applied during work against a clearance (28) -provision in the free end of the body (1), the insert holder (16) being able to be fixed and centered in the piston  (9) in any other way, namely by cross-centering, or the like.  9. Boring head according to any one of claims 4, 7 and 8, characterized in that the piston (9) is provided with a longitudinal clearance extending along a generat # rice, provided with the footprint of the micrometric screw (10), and intended to cooperate with the latter, which then has a larger diameter and extends tangentially to the piston (9).  10. Boring head according to any one of claims 4, and 7 to 9, characterized in that the piston (9) is in the form of a dovetail piece, of a polygonal piece, or toothed or grooved profile, the screw (10) cooperating with a nut fixed on the upper part of the piston.  11. Boring head, characterized in that, for roughing work, it is constituted by a body (29) having at its rear part a fixing tail, or the like, and at its front part an open housing having sides advantageously slightly inclined while widening in the direction of the tail, or sides parallel to the axis provided with grooves, or rectified guide teeth, or the like, by insert holders (30) and (31) adjustable in position in the body (29), by a screw for locking the insert holders (30) and (31) between the sides of the housing cooperating with a tapped hole (32) on one side of said housing and passing through it on the other side, as well as a transverse groove of the insert holders, and by a device (33) for adjusting the insert holders.  12. Boring head according to claim 11, characterized in that the device (33) for adjusting the insert holders (30) and (31) is constituted by two pins (34, 34 ') each secured to one wafer holder  (30) and (31) and penetrating through two paral grooves  leles (35) and (36) in two threaded holes (37) through  the body (29) right through, one of the grooves (36)  being open at one end, and the other groove (35)  being closed, and the transverse extension of said grooves  res is defined by the door adjustment length  plates (30) and (31), and by two pairs of screws (38)  engaged in the threaded holes (37) to actuate the pins (34) and (34 ') from the two  sides of the holes (37).  13. Boring head according to claim 11,  characterized in that the body (29) present on each  side a clearance (39) allowing an easy evacuation  shavings, as well as an orifice (40) for the arrival of  cooling lubricant, which arrives through channels (41) connected to a rear central channel (42).  14. Boring head according to claim 11,  characterized in that a third insert holder is  mounted in place of one of the first two insert holders  (30) and (31) and has a tool offset longitudinally  compared to the other tool in order to make a cut  deferred and a division of the width of the chips.  15. Boring head according to claim 1,  characterized in that, for the realization of large  bore diameters, it consists of a body  (43) carrying the adjustments, the piston (9), the fixing and  the insert holders, by a fixing sole (44)  and guiding the body (43) by means of screws (46), mounted  with possibility of indexing on an attachment and provided  a centering bore (47) on a corresponding hub  of an attachment, known per se, this attachment being  further provided with regularly spaced holes on a  diameter and intended to cooperate with screws (48) for  fixing and indexing the sole (44), which is  provided on its face turned towards the body (43) with a tongue  longitudinal (49) intended to cooperate with a corresponding centering groove (50) of the body (43), and allows  both a guided movement of said body (43) on the sole (44), and by a device (45) for guided movement of the body (43).  16. Boring head according to claim 15, characterized in that the device (45) for guided movement of the body (43) consists of a driver (51) having two parallel flats and fixed in the body (43), in the axis of the groove (50), by a nut (52) provided with a transverse groove (53) intended to cooperate with the driver (1), guided in translation in a groove (54) of the sole (44), and driven by an adjustment screw (55), which is subjected in translation by a groove and ball mounting (56), and guided at its other end in a housing (57) of the sole.  17. Boring head according to any one of claims 15 and 16, characterized in that the holding and the guiding movement of the body (43) on the sole (44), during adjustment, are ensured, in addition , by two pins (58) slidably mounted in two holes (59) drilled in the body (43) and extending parallel to the centering groove (50), these holes being connected to the application face of the body ( 43) on the sole (44) each by a groove (60) for the passage of the fixing screws (46), which are screwed into threaded holes (61) extending perpendicular to the axis of the pins (58), which have over their entire length, on the side of the screws (46) a flat (58 ') and the holes (59) are closed, after mounting of the rods (58), by plugs stuck in recesses (59') provided at their extremities.  18. Boring head according to claim 17, characterized in that between the threaded holes (61) is provided an additional threaded hole (62) oriented in the same direction as the holes (61) -, but preferably , of smaller diameter, into which two screws (63) and (64) penetrate, one of which (63) cooperates with a groove (65) of the body (43) and prevents the rotation of the rod (58) corresponding in its housing and forms a stop for the movement of the body (43) on the sole (44), while the other, (64), facing the sole (44), exceeds the corresponding face of the body (43) and cooperates with a corresponding groove (66) of the sole (44) for positioning the body (43) on said sole (44) during assembly.  19. Boring head according to any one of claims 15 to 18, characterized in that the sole (44) is provided with at least two sets of nut (52) adjusting screw (55) and holes for screw mounting and blocking (46).  20. Boring head according to any one of claims 15 to 19, characterized in that, in the case of boring heads of average diameter not allowing a fixing of the body (43) directly on the sole (44 ) by means of the screws (46), due to the size of the attachment, there are provided two screws (68) having a part (68 ') provided with a thread penetrating into a hole (61) of a rod (58) and a male part (68 ") penetrating into a bore of the part (68 ') turned towards the sole (44), this part (68") being retained in its bore by a groove and ball connection (69 ) allowing a pivoting of the part (68 ") after tightening of the part (68 ') in the rod (58) by means of two flats (70) of the part (68'), and the part (68") is provided, near its free end with a conical hole (71), perpendicular to its axis, and into which enters a conical screw (72) fixed in the sole (44), and whose axis is offset from to that of the hole (71), and in the extension of the hole (71) is fixed, with a slight offset towards the body (43), a lug (73) allowing the centering of the base of the screw (68) during its introduction into the corresponding hole (67) of the sole (44) by cooperation with a groove (74) of said hole (67).  21. Boring head according to any one of claims 15 to 20, characterized in that the body is in the form of an intermediate support block (75) or an upper support block (76), the intermediate block (75) being fixed in an adjustable manner on the sole (44), centered on the latter by means of a groove (77), and provided with threaded holes (78) for receiving the fixing screws of the upper block (76), which is guided on the intermediate block (75) by means of a tongue (79) cooperating with a groove (80) of said block (75), and which is provided with two additional housings of fixing screws allowing additional movement of the block (76) on the block (75).