FR2529121A1 - DEVICE FOR ADJUSTING THE DISTANCE BETWEEN THE EDGE OF A TOOL AND THE AXIS OF ROTATION OF THE DRIVE SHAFT OF A TRAINING HEAD - Google Patents

Abstract

TO ALLOW CONTINUOUS AND PRECISE ADJUSTMENT OF THE TOOL MOVEMENT, BY MEANS OF A PROGRAM CONTROL SYSTEM, THE TOOL CAN BE MOVED BY MEANS OF A DRAWBAR 9 WHICH PASSES THROUGH THE DRIVE SHAFT . THE DRAWBAR 9 CAN ROTATE BUT IT IS HELD RIGIDLY IN THE AXIAL DIRECTION BY MEANS OF A SUPPORT DEVICE. THIS IS DRIVEN IN THE AXIAL DIRECTION BY A GUIDANCE SLEEVE 25. THEIT GUIDANCE SLEEVE 25 IS LOCATED ON A PIN 19 WHICH CAN BE DRIVEN IN ROTATION, WITHOUT CLEARANCE, BY MEANS OF A DIRECT CURRENT MOTOR 13, BY L 'INTERMEDIATE OF A GEAR TRAIN 14, 15, 16, 18.

Description

The invention relates to an adjustment device for

  a tool placed on a dressing head mounted on a drive shaft driven in a rotational movement, this device making it possible to adjust the distance between a cutting edge of the tool

  and the axis of rotation of the drive shaft.

  A device of this kind is described in the publica-

  tion "NC-Praxis" of June 1981 The adjustment of the tool by means of a hydraulic cylinder has the disadvantage of allowing only one speed of movement and that it does not allow

  achieve high adjustment accuracy.

  The object of the present invention is to provide a

  device of the kind mentioned above, which makes it possible to obtain

  provide continuous and precise positioning of the tool with one head

  training using a program control system.

  According to the invention, this problem is solved by the fact that the movement of the tool is controlled by means of a drawbar which passes through the drive shaft, said drawbar being housed in a support device. which surrounds the bar leaving it free to rotate but determining

  its position in the axial direction, said support being fixed to the ex-

  inside of a guide sleeve whose movement is controlled, without play, by a spindle whose rotation is controlled by means of a direct current motor, by means of a gear train With the current motor continuous we can get a linear displacement of the drawbar, the distance

  traversed corresponding to the angle of rotation of the

  continuous current The functional link between the running motor

  continuous rant and the drawbar is practically free of play By acting on the supply voltage of the DC motor, the speed of movement can be adjusted.

  drawbar accompanies the dressing head in its movement

  rotation The feed movements of the dressing head are independent of the drawbar They have no

  influence on the adjustment or positioning thereof.

  According to an embodiment of the invention, the train of-

  graining is adjusted without play with intermediate gears subjected to a tightening on their side, as for the connection

2529121-

  between the spindle and the guide sleeve mentioned above

  ment we use a double nut also adjusted with zero play; it is also planned to use a pull-up bar

  constituted by a hollow rod, to have cams of com-

  command on the guide sleeve, to equip the motor with current

  continuous digital angular displacement sensor.

  Advantageous formatting possibilities

  the invention follows from the description below, with-

  support, and of the possible characteristics listed above

  above The different figures of the drawing show respective-

  ment: Figure 1: the schematic view of a machine equipped with the adjustment device according to the invention, Figure 2: a sectional view along line IIII of Figure 3, of the adjustment device according to the invention, and Figure 3 v a plan view of the adjustment device

according to the invention.

  A carriage 2 can move on a machine bench 1 according to the direction from advances V A workpiece 3 is

  clamped in position on the machine bench 1.

  The carriage 2 supports a drive motor 4 which, by means of a belt transmission 5 drives a shaft 6 in the direction of rotation D A straightening head 7 is mounted on the shaft 6 A tool 8 can be move on said dressing head in direction E. The movement of tool 8 in the direction indicated

  by the double arrow E is obtained by means of a drawing bar

  tion 9 which, for this, can move axially in the direction Z The drawbar 9 crosses the shaft 6 right through and turns with it On the side opposite to that where the dressing head is located, the end of the drawbar 9 can rotate in a support device 10 which however maintains it rigidly in the axial direction This support device can be moved by means of a DC motor 13, by means of a control spindle 11 and a drive train 12 The DC motor-13, with the train

  12 and the control pin 11 are also inserted.

mounted on the carriage 2.

  The drawbar 9, the support device 10, the control spindle 11, the drive train 12 and the DC motor 13 constitute the adjustment device for

  the tool 8 This device has been represented in FIG. 2.

  The speed of rotation of the DC motor 13 is adjustable up to approximately 3000 rpm, said motor comprises a digital angular displacement sensor. It is thus possible to prescribe in absolute value, by means of a program control system. , the number of revolutions that the engine must perform

  for the desired displacement of the drawbar -

  On the shaft of the DC motor 13 is mounted a double pinion 14 The latter is engaged on the one hand with a first intermediate pinion 15 and on the other hand with a second intermediate pinion 16 The intermediate pinion 15 is housed on a intermediate shaft 17 The second intermediate gear 16 is housed on the first intermediate gear

  The two intermediate gears 15 and 16 are angularly offset

  in relation to each other so that the two pinions are in contact, respectively, one with the right flanks, the other with the left flanks of the teeth of the double pinion 14 There is thus a possibility of adjustment for

  get backlash-free transmission The two toothed wheels

  intermediaries 15 and 16 attack a toothed wheel 18 Between this and those there is also obtained a transmission without play The toothed wheel 18 is mounted on a threaded spindle

  balls 19 which is housed in a rolling bearing 20.

  The threaded ball spindle 19 carries a double nut composed of two nuts 22 and 23 which can be prestressed relative to each other by means of the screws 21 On the nut 23 is fixed, by means of a screw, a ring 24 which is secured to a guide sleeve 25 The latter can move

  in direction Z, inside a casing 26.

  On the guide sleeve 25 is fixed a drive block

  27 This extends outward through a

  slot 28 of the housing 26 On the outside of the housing 26 the block of

  undercarriage 27 includes a rolling bearing 29, in which is housed a hollow shaft 30 The drawbar 9 is fixed to

  the hollow shaft 30 by means of the clamping devices 31 and 32.

  The draw bar 9 is hollow, at its end is disposed a box 33 containing the lubricant or coolant which must be sent to the dressing head 7 through the

hollow drawbar 9.

  Control cams 34, 35 and 36 are attached to the handle.

  guide bead 25 outside the casing 26 (see FIG. 3).

  These cams 34, 35 and 36 act on the electric switches.

  ques 37 The control cams 34 and 36 are used to cut the feed

  ment of the DC motor 13 at the end of travel La

  control cam 35 is used to determine a reference point.

  The operation of the adjustment device according to the

  vention can be described as follows

  If the DC motor 13 is supplied, it

  ci controls the rotation of the threaded ball spindle 19 without play, so that the double nut 22, 23 moves thereon

  and determines, without play, the displacement of the guide sleeve 25.

  The guide sleeve 25 drives the hollow shaft 30 in its movement. The desired axial displacement is thus obtained.

  -traction bar 9, which-determines a corresponding displacement-

  tool dant 8 So, depending on the setting, you can

  with tool 8, dressings on different diameters

  glage is done by means of a program control system.

  The drawbar 9 follows the rotational movement of the control shaft 6 and the planar dressing head 7; She turns

in the rolling bearing 29.

Claims (5)

  1 Adjustment device for a tool placed on a dressing head mounted on a shaft driven in a rotary movement, this device making it possible to adjust the distance between a cutting edge of the tool and the axis of rotation of the shaft d 'in-   drag, characterized in that the displacement of the   til (8) can be controlled by means of a draw bar (9) which passes through the drive shaft (6), said draw bar (9) being housed in a support device (10, 29 to 32) which surrounds the bar, leaving it free to rotate but determining its position in the axial direction, said support   (10, 29 to 32) being fixed to the outside on a guide sleeve   dage (25) whose axial movement is controlled without play by a spindle (19) which can be rotated by a direct current motor (13) via a train gears (12, -14 to 18).   2 adjusting device according to claim 1, characterized in that by means of the intermediate gears (15, 16) subjected to a clamping on the sides of the teeth, the   gear transmission (12) is adjusted without play.   3 Adjustment device according to any one of   claims 1 and 2, characterized in that the sleeve   guide (25) is housed on the spindle (19) by means of a double   ble nut (22, 23) prestressed, with zero play.   4 Adjustment device according to any one of   above claims, characterized in that the bar of traction (9) is hollow.   Adjustment device according to any one of   above claims, characterized in that on the   guide sleeve (25) are arranged control cams switches (34, 35, 36).   6 Control device according to any one of   above claims, characterized in that a sensor   digital angular displacement is connected to the motor continuous rant (13).