Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B5/00—Clamps
  • B25B5/06—Arrangements for positively actuating jaws
  • B25B5/08—Arrangements for positively actuating jaws using cams
  • B25B5/087—Arrangements for positively actuating jaws using cams actuated by a hydraulic or pneumatic piston
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B5/00—Clamps
  • B25B5/06—Arrangements for positively actuating jaws
  • B25B5/061—Arrangements for positively actuating jaws with fluid drive
  • B25B5/064—Arrangements for positively actuating jaws with fluid drive with clamping means pivoting around an axis perpendicular to the pressing direction

Definitions

• the invention relates, in general, to techniques relating to mechanical machining.
• the invention relates, according to a first of its aspects, a device for clamping a workpiece on a tool, comprising a jack and a flange, the jack being selectively actuated by a pressurized fluid and itself comprising a body fixed in operation to the tooling and a rod movable relative to the body, and the flange being articulated about a pivot axis on the rod and selectively driven by the rod, this flange struggling over a determined travel between a position clamping position and a relaxed position, and undergoing rotation over at least part of its travel.
• the rotation of the flange can have the effect of sliding the part to be clamped or deforming it.
• the main purpose of the invention is to propose a compact, rapid, retractable, powerful clamping device, and moreover free from the aforementioned defects.
• the device of the invention is essentially characterized by that it further comprises guide members and support elements, in that the guide members comprise a guide member fixed relative to the body and a movable guide member connected to the flange, these guide members fixed and mobile cooperating to drive the flange in a rotational movement around the pivot axis at least at the end of its travel towards its released position and in a translational movement at least at the end of its travel towards its position clamping, and in that the support elements comprise a support element fixed relative to the body and a mobile support element linked to the flange, these fixed and mobile support elements cooperating selectively, at least in the end of travel of the clamp towards its clamping position, to offer each other, at a distance from the guide members, a sliding contact parallel to the translational movement of the clamp and allowing the clamp to brace on the workpiece ser rer.
• the guide members comprise a guide member fixed relative to the body and a movable guide member connected to the flange, these guide members fixed and mobile cooperating to drive the flange
• the rod extends along a translation axis which passes between the guide members and the support elements, this arrangement allowing a balancing of the forces resistant to clamping and a very effective self-locking of the flange.
• the movable guide member is for example constituted by a cam formed by two grooves symmetrically hollowed in the flange on either side of a median plane of the flange and the rod, transverse to one pivot axis.
• Each groove advantageously has a path whose first and second ends are respectively relatively distant and relatively close to the pivot axis, this path continuously approaching the pivot axis from its first end to its second end, and comprising a portion straight path ending at the first end and a curved path portion, adjacent to the straight path portion and ending at the second end.
• the flange is fully retractable.
• the fixed guide member can then be constituted by a pair of pins or rollers fixed to the body of the jack and respectively engaged in the grooves forming the cam.
• the movable support element is for example constituted by a support heel carried by the flange and extending symmetrically on either side of a median plane of the flange and the rod, transverse to the axis pivoting, the fixed support element then itself being constituted by a support surface of the cylinder body, on which the support heel is supported symmetrically with respect to said median plane.
• the cylinder is a double-acting cylinder, for example hydraulic, comprising first and second chambers separated by a piston integral with the rod, the flange being driven from its release position to its clamping position by admission of pressurized fluid into the first chamber of the jack, and being driven from its position tightening to its release position by admission of pressurized fluid into the second chamber of the jack.
• the fixed guide member and the fixed support element can be carried by a part of the body of the jack which is shaped as a yoke, the flange being guided in its median plane between two parallel faces facing this part forming a yoke.
• the flange is for example shaped as a yoke and encloses the body of the jack which guides it in its median plane.
• each stud or roller is advantageously located above a plane transverse to the rod containing the pivot axis, in a direction corresponding to the movement that the rod performs to drive the flange towards its released position.
• the invention also relates, according to a second of its aspects, to a method for controlling the device described above, this method being characterized in that it comprises an operation consisting in measuring the pressure of the actuating fluid admitted into this device and in check the position of the flange and / or the clamping force by checking the value of the pressure measured.
• FIGS. 1 and 2 are two perspective views of a clamping device according to a first embodiment of the invention and whose flange is in the clamping position;
• Figure 3 is a perspective view of a clamping device according to a second embodiment of one invention and the flange is in the clamping position;
• Figure 4 is a partial sectional view of the device illustrated in Figures 1 and 2 but whose flange is in the released position, the section being performed along a plane parallel to the median plane of this device;
• Figure 5 is a sectional view of the device illustrated in Figures 1 and 2, taken along the median plane of this device;
• FIG. 6 is a sectional view of the device illustrated in FIGS.
• Figure 7 is a top view of the device illustrated in Figures 1 and 2;
• Figure 8 is a partial side view of the device illustrated in Figures 1 and 2;
• FIG. 9 is a side view of the device illustrated in Figure 3;
• Figure 10 is a front view of the device illustrated in Figure 3;
• Figure 11 is a side view of the device illustrated in Figure 3 but the flange of which is in the released position;
• - Figure 12 is a sectional view of the device illustrated in Figure 3, taken along the median plane of this device.
• the invention relates to a device for clamping a workpiece P on a tool for machining, this device essentially comprising a jack 1 and a flange 2.
• the cylinder 1 is for example constituted by a double-acting hydraulic cylinder and comprises a body 10 fixed in operation to the tool itself disposed in a machining center, and a rod 11 movable relative to the body 10 of this cylinder .
• the body 10 of the jack has a bore inside which a piston 12, integral with the rod 11, delimits two chambers 101 and 102 of variable and complementary volumes, opening to the outside by means of respective ports lOlp and 102p each of which can be connected to a high pressure hydraulic source while the other is connected to a low pressure tank.
• the flange 2 which is articulated on the rod 11 around a pivot axis X, is driven at will by the rod 11, itself driven by the piston 12.
• the flange 2 thus struggles, over a determined stroke, between a clamping position illustrated in particular in FIGS. 1 to 3, and a release position, illustrated in Figure 4 for the first embodiment, and in Figure 11 for the second embodiment.
• the flange 2 is driven from its release position to its clamping position by admission of pressurized fluid into the first chamber 101 of the jack 1, and is driven from its clamping position to its release position by admission of fluid under pressure in the second chamber 102 of this jack 1.
• the device of the invention derives most of its advantages from the fact that it comprises guide members 3 and support elements 4, the guide members 3 themselves comprising a guide member 31 fixed relative to the body 10 and a movable guide member 32 linked to the flange 2, and the support elements 4 comprising, in the same way, a support element 41 fixed relative to the body 10 and a mobile support element 42 linked to the flange 2.
• the fixed and movable guide members, 31 and 32 cooperate to drive the flange 2 in a rotational movement around the pivot axis X at least at the end of the travel of this flange towards its released position, and for drive the flange 2 in a translational movement at least at the end of the travel of this flange towards its clamping position.
• the fixed and mobile support elements, 41 and 42 cooperate, at least at the end of the travel of the flange 2 towards its clamping position, to offer each other, at a distance from the guide members 3 , a sliding contact parallel to the translational movement of the flange 2 and allowing a bridle 2 bracing on the workpiece P.
• the rod 11 preferably extends along a translation axis Z which passes between the guide members 3 and the support elements 4.
• the movable guide member 32 is constituted by a cam formed by two grooves, such as 32a, symmetrically hollowed out in the flange 2 on either side of a median plane M of the device , this median plane M being transverse to the pivot axis X and constituting a plane of symmetry for the flange 2 and for the rod 11.
• the flange 2 In addition to the groove 32a, the flange 2 therefore has a groove 32b which, although not visible in the figures, is deduced from the groove 32a by symmetry with respect to the plane M.
• Each of the grooves 32a and 32b has a path which continuously approaches the pivot axis X from the first end 321 of this path towards its second end 322. As shown in FIGS. 4, 9 and 11, this path comprises a portion of rectilinear path 320r which ends at the first end 321 and a portion of curved path 320c, adjacent to the portion of rectilinear path 320r and ending at the second end 322.
• the fixed guide member 31 is itself constituted by a pair of pins or rollers, such as 31a, fixed to the body 10 of the jack 1 and respectively engaged in the grooves forming the cam.
• the body 10 In addition to the stud or the roller 31a engaged in the groove 32a, the body 10 therefore has a stud or a roller 31b engaged in the groove 32b and which, although not visible in the figures, is deduced from the stud or roller 31a by symmetry by relation to the median plane M.
• each stud or roller such as 31a is located above a plane T which is transverse to the rod 11 and which contains the pivot axis X, when following a direction which corresponds to the movement carried out by the rod 11 to drive the flange 2 to its relaxed position.
• the movable support element 42 is constituted by a support heel which is carried by the flange 2 and which extends symmetrically on either side of the median plane M of the device.
• the fixed support element 41 is in turn constituted by an external support surface of the body 10 of the jack 1, on which the support heel 42 is symmetrically supported relative to this same median plane M.
• the rod 11 leaves the jack 1 on the side of its first chamber 101.
• the fixed guide member 31 and the fixed support element 41 are advantageously carried by a part 100 of the body 10 of the jack which is shaped as a yoke, and the flange 2 is then guided in its median plane M between two parallel opposite faces, 100a and 100b, belonging to this part 100 forming a yoke.
• This embodiment allows a significant rotation of the flange 2 between its tightening position and its relaxed position, typically a rotation of amplitude equal to or greater than 90 degrees.
• the cylinder 1 can in this case be mounted in a base 5 fixed on the tool, forming a fluid distributor, and therefore itself comprising two fluid input-output ports lOlq and 102q corresponding respectively to the ports lOlp and 102p of the jack 1.
• the rod 11 emerges from the jack 1 on the side of its second chamber 102.
• the flange 2 which is shaped as a yoke, this flange then enclosing the body 10 of the jack 1, which guides it in its median plane M.
• the measured pressure it is therefore possible to provide for the measured pressure to reach or exceed a determined minimum threshold, typically to prevent the clamping force from being insufficient, or to provide for the measured pressure to remain below a determined maximum threshold. , for example to prevent the clamping force from damaging the workpiece.
• this process has the additional advantage of allowing very fine adjustment of the clamping force in the case where the actuating fluid consists of compressed air.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Jigs For Machine Tools (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Communication Control (AREA)
• Clamps And Clips (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34586368

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (4)

Citations (5)

• 2003
  • 2003-12-04 FR FR0314358A patent/FR2863190B1/fr not_active Expired - Fee Related
• 2004
  • 2004-12-03 ES ES04805643T patent/ES2287803T3/es active Active
  • 2004-12-03 WO PCT/FR2004/003124 patent/WO2005056241A1/fr active IP Right Grant
  • 2004-12-03 DE DE602004006647T patent/DE602004006647T2/de active Active
  • 2004-12-03 AT AT04805643T patent/ATE362827T1/de not_active IP Right Cessation
  • 2004-12-03 EP EP04805643A patent/EP1697088B1/de active Active

Patent Citations (5)

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