FR2517580A1 - DEVICE FOR SECURING PARTS IN POSITION ON MACHINE TOOLS - Google Patents

Abstract

A. THE INVENTION CONCERNS A DEVICE FOR FIXING IN POSITION OF PART HOLDERS ON MACHINE TOOLS, INCLUDING FIXING MEMBERS 11, 11, 11 OFFSETS OF 90. THE PROBLEM SOLVED CONSISTS OF ENSURING PRECISE FIXING WITH SIMPLE MEANS. B. THE DEVICE IS CHARACTERIZED IN THAT OF THE FIXING UNITS BY CLAMPING CLAMPS 11, 11, 11 HAVE FIXING ELEMENTS 14 PLACES PER PAIR SO THAT AT LEAST ONE PAIR OF ELEMENTS IS PERPENDICULAR TO THE INPUT DIRECTION 7 OF A PIECE HOLDER, EACH ELEMENT CONSISTING OF 14 LEVERS MOUNTED ON A BASE PLATE 12 OF EACH UNIT. C. THE INVENTION IS APPLICABLE TO THE FIXING OF PART HOLDERS ON MACHINE TOOLS.

Description

"Device for fi xing in position of workpieces on machines-out

ls J "

  The invention will include a device for

  set the fixture precisely moving parts carriers

on machine tools.

  Fastening devices of the most diverse types are known In patent DD-PS 122 3369 for example, a device for cueing by an index is known.

  for attaching workpiece carriers to machines

  In this device, two reference pins with an index are placed on the workpiece holders each fixed in a socket on the table

  The free end of the index dowel has a

  spherical and meshes with its largest diaemeter in recesses of a bucket seat of each bushing

of fixation.

  Given that we are forced to work with additional cylinders imprecise position must be incurred a relatively large expenditure, The patent DD PS 88 874 describes a locking equipment for parts of pPcarpen machine tool machine, or the index stud is constituted at one end, according to a thin-walled hollow body in which a pressure medium is put in place. This causes, by increasing the pressure in the final position of the index pin in an opposite guide, a stress 2 .- quotation of the surface envelope of the dowel forward in

the opposite guidance.

  The index pin itself is connected, by means of a pressure transmission piston, directly to the pressure volume for the displacement of the stud. This device avoids, in truth, an intermediate stage of an imprecise position, then the adjustment game can be held

  However, it is also necessary to

think relatively big.

  DD PS 122 934 discloses a device for attaching workpieces to be machined in which cylindrical adjustment members are machined.

  placed horizontally and shifted by 900.

  tif, in truth, does not use a hydraulic system,

  but, in addition, it needs a great deal of

  mechanical. The object of the invention is to create a device for the fixing in position of workpieces to be machined on machine tools, which with regard to simple mechanical means makes possible a fixation-repeated, precise in plan and in the The defects described in the characteristic of the known technical solutions, come from the fact that a fixation can be carried out only with the concurrence of additional elements, such as the use of a machine. hydraulic pressure or the like, or only

a high mechanical expense.

  To eliminate these defects, the main object of the invention is to create a device for fixing in position workpiece carriers on machine tools, with fastening elements, shifted to 900,

  other, this device allows a precise fixation, re-

  bitter, fast without play and at the same time following several

  dimensions, that is to say in all directions

  required without additional equipment The fixing forces must be established autonomously by increasing to the required value and must be

  kept unchanged until separation.

  The invention relates, for this purpose, to a device of the above type, characterized in that, in the

  fastening units by clamps on the machine-

  tool, fasteners are placed in pairs,

  so that with respect to the direction of entry of a door-

  workpieces, at least one pair of fasteners

  tion is placed parallel and at least one pair

  fasteners is placed perpendicular-

  the one-armed lever fasteners with rounded ends being placed on a base plate of a spring-loaded clamping unit by means of springs, so that

  the opposite ends of the lever are oblique-

  up and that their interval is all the

  larger than the contact surfaces of a cam,

  as support surfaces, are distant from each other

  other things, in that when the workpiece holder is lowered,

  se, the ends of the lever being initially upward, are brought into abutment on the bearing surfaces, a fixing stop being arranged with its cam so that in

  the fastening direction considered, there is a very large

  of elastic rigidity and in the other directions only

  a low elastic stiffness of the abutment

  tion, so that a fixation without play and at the same time

  several dimensions of the workpiece carrier is

  guarantee in fixing units by clamps

arranged on the machine tool.

  Fixing units with clamps

  each consist of a base plate,

  both of the bearing surfaces placed on the inside, on the two sides opposite to the other two opposite sides of the plate 4.-

  each time they are outside, two pa-

  such as pivoting bearings for the fasteners. On a shaft, which serves as a pivot shaft for the fasteners, are placed on two sides, a fastener, driving fingers, which, each time, are assembled, by means of a dowel and a sleeve of spacings with the fastening elements for

  constitute a unit Each finger of training

  In addition, a lever mounted integrally and perpendicularly

  stretching on him, the free end of this lever being

provided with a drilling -

  The free ends of two opposite levers of the driving finger are connected each time by means of a spring in the pivoting area of the end.

  free of a drive finger, is placed on each

  pivoting link, an adjustable eccentric stop and

  9 The rounded ends of the fixing elements

  may also be equipped with a roller.

  The device is further arranged so that a hydraulic cylinder assembly comprising a cylinder

  and a piston, moreover articulated on a finger of training.

  in a clamping unit, the operating element for feeding and removing the

workpiece holders.

  the device is also advantageously constituted so that the fixing holding force

  exclusively by the movement of lowering

  the workpiece carrier, the maximum holding force

  being obtained at the end point of the movement of

  the rectilinear position of the fixing elements

  with a pivot angle X = 0.

  It is also possible, however, to achieve closure of the fasteners in cases where the entire lowering movement of the workpiece carrier is not achieved at all, eg at the height required or only with d think too big

  This can be done either by lifting the to-

  tality of the fastening element by clamping clamps, or else, which is essentially better only

  by lifting a plaque from the J age O the ibitrieu of llmui-

  This fixture can also be made in parts, namely that the door can be replaced by parts; u L.

  small path and 1 fixat-ion by clamps-

  or only the lifting plate has the inside of this fastening unit running the longest way. This is achieved by means of a coupler with a unit in its own right, with a hydraulic cylinder comprising a piston.

  The big advantage of the device is also

  if the control force is very small relative to the force of maint, this ratio being given by the following equation: FB = (2 sinc O + Lji R p in which: F = holding force for the fixing FB = working force

  k = angle of opening or of: fre + tre of the elements of

  x, R = radius of the fixing element L = length of action of II element = coefficient of friction, The invention will be better understood with respect to

  the following description and anxious drawings represent

  examples of embodiments of the invention,

  in which: FIG. 1 shows the principle arrangement of the fastening elements by clamping clamps on the machine tool, FIG. 2 is a section along the line 6.-AA of FIG. 1, FIG. provision of

  principle of an embodiment with a lifting plate.

  On the lower side of a movable workpiece carrier 1, three fixing stops 2, 2 ', 2 "are placed securely (FIG. 1). These stops are provided with a support arm, the end of which is reinforced and is provided at its lower part with a surface 4

  a cam 5 protrudes from the bearing surfaces 6.

  The workpiece holder is movable forward and

  back, each time, in the directions 7, 8, 9.

  On the machine tool 10, are mounted fixed station clamping units by clamping clamps

  11, 11 ', 11 ", corresponding to the number of fixing abutments

  2 '2', 2 "A unit is provided for the adjusting direction 7 and two units are provided for the direction of

  8 Each of the attachment clamps with

  11, 11 ', 11 "is constituted by a base plate 12

  with a raised edge which is provided on these two opposite sides.

  The support surfaces 13 are pivotably mounted on the baseplate 12 between the support surfaces 13 and the fixing elements 14.

  has a single arm lever, having a length of

  The ends of the levers are rounded to a radius R. The base plate 12 is clamped on its front end by clamping bars 15 on the machine tool. On the side surfaces of the base plate 12 are

  each time firmly placed, two levels 16 constituting

  kill pivot bearings for the fastening elements

14.

  To a fastening element 14, belong, in

  in addition, a shaft 17, on which are the two ends,

  of the fixing element 14, and a coupling finger

  18 with a lever 19 which, at the center of rotation, is 7.-

  mounted perpendicularly to the drive finger 18.

  The connection of the fixat-ion element 14 and the finger of

  processing 18 is carried out by means of a Vécar-

  20 and a bolt 21 The lever 19 is provided at its free end with a bore 22. The levers 19 e each placed opposite the base of the base plate 12,

  connected to a spring 23, which is fixed in the holes

22.

  At the point of intersection of the drive finger 18 with the lever 19 is provided a pergage, which receives the shaft 17. As a result, the fastening element 14 and

  the driving finger 18, with its lever 19, are

  linked to pivot by means of two bearings 16 with the

than basic 12.

  In the pivot zone of the end

  free core, driving fingers 18, an abutment 24 ex-

  centric is placed on each bearing 16, this stop

  being adjustable and can be fixed.

  Fixing unit with clamps 11

  of the adjusting device 7 is arranged in such a way that

  A hydraulic cylinder assembly controlled by a piston is pivotally mounted on a drive finger 18. By means of a protection 26, the attachment stops 2, 2 ', 2 "

are protected in addition.

  The embodiment according to FIG. 3, is based on the same principle. On the machine tool 10, units of

  clamping clamps 31, 31 ', 31 "are respectively

  placed in a dwelling, the number of these units

  corresponding to the number of fixing stops 2, 2 ', 2 ".

  These gripper clamping units 31, 31 ', 31 "are constituted by a main body 32 which is connected

  securely to the casing 33 of a cylinder.

  In the main body 32 there is a

  34 vertical, in which a lifting plate 35 is movable up and down The lifting plate 35 8.-

  is connected for this purpose to a hollow piston 36.

  On the longitudinal side of the lifting plate

  is placed for each fixing element 14, a pa-

  Link 37, as a pivoting bearing The fixing elements 14 are installed by means of a shaft 38 in the brackets

  37, pivoting on the basic body 32.

  Under each one of the two fixing elements

  14, is placed in the lifting plate 35 in a hole

  one-eyed, a piston 39 with a spring 40

  that closing 41 of the casing of the cylinder 33, is

  placed inside the cylinder 33, a fixed piston 42.

  The device operates as indicated below

  after: When a workpiece carrier is to be fixed in several dimensions on a machine tool,

  then it will be roughly positioned in the di-

  setting 7 so that it can be

  until it comes to the fixing stop 2 of the

  fixing element 14 opposite to the direction of entry.

  14, opposite to the previous one, will be by the entry Ode the workpiece) lowered and crossed Then, the

  workpiece carriers 1 in direction 9 will be actuated, that is,

  to say will be lowered the surfaces 4 stops fixing

  2 then first touch the free ends of the fasteners 14, which are pivoted from the angle

  ci by means of the springs 23 or 40 with respect to the

  reference face of the baseplate 12, or body

  This pivoting is limited by the outer abutments

centric 24.

  By a further lowering of the workpiece carrier 1, the fastening elements 14 begin to close, and if the angle ck has become zero, i.e. when the lowering movement is complete, the elements fasteners 14 came in contact with the surfaces

  of support 6 of the fixing stops 2 in position The holder

  9.- workpieces 1 is thus clamped on the machine toolo At the same time, the other ends of the fastening elements 14 are applied against the wrfac es of support 13 of the plate

  12, for example in the drilling 34 di orps prini-

  In the position and position of the fixing members 14, the holding force P of attachment reaches its maximum value.

  Having been asleep for only a very long time

  In the case of the dimensions, at least one clamping clamp 11 must be used for the steering direction, the arms 3 being relatively long and having 3 fastening points 2, must have the fastening elements pinched by the clamps. Reciprocally, it is still possible during the fastening process, that is during the lowering of the workpiece carrier 1 in the clamping clamping unit 11, it is still possible to perform 7 small corrective placement steps, in the orthogonal direction of each element 11 by the elastic conformation of the iutees.

fixing 2.

  To separate the workpiece carriers 1 from the clamping clamps 11, it is sufficient to raise the workpieces 1 to be machined The workpieces 14 separate from the support surfaces 6 of the cam 5 and leave free again the workpiece holder in usinera

  because, thanks to the action of the 23 and 409

  fasteners 14 are again articulated by the stop

  up to the stop of the driving fingers 18.

  In the clamping unit with clamps

  ge 11, for the direction of adjustment 7, the fixing element

  14 now locked in the starting direction is lowered after lifting the workpiece carrier 1 by means of a

  hydraulic cylinder assembly, controlled by a piston,

  that the pivot angle i is zero The replacement

  the workpiece carrier is then possible.

  By an execution according to Figure 3, the 10.-

  lifting plate 35 in the direction of adjustment 9 within the

  clamping element 31, is relievée in place of the workpiece holder 1 Il

  also follows here first of all a contact of the

  free parts of the fasteners 14 which, by the springs 40 are articulated around the angle c 4, with the

  surfaces 4 of the fixing stops 2.

  By a new lifting of the lifting plate 35, the fastening elements 14 close, until they are again firmly fixed in their rectilinear position to the bearing surfaces 6 of the cam 5 and clamped to the holder. workpieces 1 with fixing unit

  by clamping clamps II and from there on the machine tool 10.

  For the separation of the workpiece holder, simply lower the lifting plate 35 By the action

  of the springs 40, the fastening elements 14 are again

  calves lowered and release the fixing stop 2 and therefore

  the workpiece holder 1 for its replacement.

1 1.

R E VS E N D I C A T IO N S

  Device for fixing in position of the workpiece holders on machine tools comprising fasteners offset from each other by 90%, characterized in that in clamping clamp fixing units (I 1) on the machine tool, fastening elements (14) are arranged in pairs so that, with respect to the input direction (7) of the workpiece carrier (1), at least one pair of fixing elements (14) is placed parallel and at least one pair

  fastening elements (14) is placed perpendicularly

  the fastening elements (14) are constituted by a lever with a single arm, the ends of which are rounded

  being placed on a base plate (12) of a filter unit

  by clamping pliers (11) under the action of springs (15), so that the opposite ends of the lever (19)

  present themselves obliquely upwards, and that their

  range is even greater than the

  of a cam (5) formed as bearing surfaces (6) are spaced from each other, in that, when the workpiece carrier (1) is lowered, the e> tremors of the lever (19) first standing up are brought

  abutting on the bearing surfaces (6), a bu

  tion (2) being arranged with its cam (5) so that, in the fastening direction considered, there is a very high elastic rigidity and in the other directions only, a low elastic rigidity of the fixing abutment (2),

  so that a fixation without play and at the same time

  the dimensions of the workpiece carrier (1) are

  fastening units with clamps (11)

  arranged on the machine tool (10).

  2. Device according to claim 1,

  characterized in that the fastening units by clamping collets (11) are preferably mounted on a plate of

  base (12) with bearing surfaces (13) arranged in the

12.-

  on two opposite sides and on two out-

  opposite sides, respectively two levels (16) consis-

  pivoting bearings for the fixing elements

  (14), a drive finger (18) being mounted on a shaft (17) of both sides of a fastening element (14), said finger being connected by means of a pin (21) and a spacer sleeve (20) to the fastening elements (14),

  and each drive finger (18) being provided with a

  (19) fixed orthogonally to him solidly, the ex-

  free ends of two opposite levers (19) being connected

  by means of a spring 23, an eccentric abutment (24)

  glable with possibility of fixing being arranged in the

  pivoting area of the free end of the fingers of

  flow (18) on each bearing (16).

  3 Device according to one or other of the

  1 and 2, characterized in that in the gripper clamping unit (11) of the adjusting direction (7) a hydraulic jack assembly, controlled by

  a piston is articulated on the drive finger (18).

  4 Device according to any one of

  Claims 1 to 3, characterized in that the force of

  fastening is applied exclusively by the lowering movement of the workpiece carrier, a

  maximum holding force P being obtained at the end point

  of the lowering movement, that is to say in the

  rectilinear arrangement of the fastening elements (14) with a

pivot angle o = 0.

  5. Device according to any one of

  Claims 1 to 4, characterized in that the force of

  command is very small compared to the force of

  the ratio of the dimensions of the fastening elements (14) depending on the equation: B = (2 sin c + r) P. 6. Device according to one or other of the

  claims 1 and 4, characterized in that the path

1 7 5 8 O

  13.- approach of the doorpi L - (, - s (1; v, rzi the -Lmit 'of U e

  fastener (31) with clips of

targeted in a short chem-in (b r%

  a longer Path Vulir-, j, ILIr, -411 -,?, of, -0,11 i-

fixing tee by rIne (- 1