FR2664840A1 - DEVICE FOR MAINTAINING A PIECE TO RODER DURING ITS RUNNING. - Google Patents

Abstract

The present invention relates to a device for holding a part to be lapped during its lapping, which comprises a fixed bearing part (5), a bearing part (6) movable relative to the first in the direction lapping and means for clamping the part to be lapped (1) between the movable support part and the fixed support part. According to the invention, this device comprises means (14) for pre-clamping the part to be lapped.

Description

To lapping a part, it is necessary to place it on a support

  so that it is well maintained during break-in In addition, it is necessary that the piece is well centered with respect to the grinder and in alignment with it. These settings are delicate and misalignments can occur when the grinder is introduced. in the room when centering. The present invention relates to a device for holding a workpiece during lapping

which solves this problem.

  2 - This device comprises a fixed support piece, a bearing piece movable relative to the first in the direction of lapping and means for tightening the piece to be honed between the movable support piece and the support piece fixed and is characterized in that it comprises means for pre-tightening the

piece to be honed.

  Pre-tightening makes it possible to center the workpiece relative to the lapper and to make the necessary adjustments; the

  tightening is then ensured to perform the break-in.

  An embodiment of the device according to the invention is described below, by way of nonlimiting example, with reference to the accompanying drawings in which: FIG. 1 is an axial sectional view of the device before pre-clamping; Figures 2 and 3 are views

  similar to Figure 1 in the preface

  Tightening. Figure 4 is a view similar to Figure 1 when tightening; Figure 5 shows ways to adapt the stroke of the support piece

  mobile to the thickness of the piece to be honed.

  The device according to the invention makes it possible to maintain a part to be honed 1, which in the embodiment shown is a connecting rod, during its break-in using a bead 2, guided by a bearing 3 - fluid 3 and carried by a head 4 at a time rotating

and axially movable.

  This device comprises a fixed support piece 5 and a support piece 6 movable in the direction of break-in This part 6 is mounted movably in a part 7 which is itself movable in a fixed frame 8 against the action of springs return 9 under the action of a shaft or axis 10; the latter has one or more ramps such as 10 has in contact with the workpiece 7 and is coupled to a control cylinder 11 (Figure 5) Thus, the piece 7 can move from one level to another by sliding on the ramp when the shaft moves under the action of the cylinder, the part 7 being pressed and locked against surfaces of the shaft

  such as 10 b thanks to the springs 9.

  The part 6 has a portion 6a which is piston-shaped and is arranged between two chambers 12 and 13 of the part 7 A ring 14 interposed between the chamber 13 and a chamber 15 limits the stroke of the piston 6a; means not shown allow to admit a fluid under

  pressure in chambers 12,13 and 15.

  The part 6 has inclined holes 6b allowing the evacuation of the overflow of lubricant that the burr 2 goes up. Moreover, inductive sensors 16a and 16b cooperate with an element 17 integral with the part 6 to detect the positions.

high and low of this piece.

  The device is first adjusted according to the thickness of the part to be honed 1, with the aid of the cylinder 11. Then, the part 1 is pre-clamped on the support piece 5. occupying rooms 4 - initially the positions of Figure 1, the chambers 12 and 15 being exhausted and 13 under pressure, 13 is exhausted while pressurized fluid, for example 45 bar is allowed in the chamber 15, which raises the ring 14, the latter being pressed against a shoulder of the part 7 (Figure 2); then it is admitted into the chamber 12, for example under 20 bar, which causes the descent of the room

  6 and pre-tightening the workpiece (Figure 3).

  We then lower the grinder 2 in the room 1 by inflating it When we reached the minimum torque, that is to say when the grinder came into contact with the wall of the bore of the room, we can proceed by tightening For this purpose, the pressure in the chamber 15 is suppressed; the ring 14 descends and the piece 6 follows its movement under the effect of the pressure in the chamber 12 (Figure 4) The passage of the part 6 from the starting position (Figure 2) to the pre-tightening is indicated by the detectors 16 a and 16 b The displacement of this part 6 when passing from the pre-tightening to the tightening being very small, the tightening is considered as realized when the pressure is in the chamber 12 and more in the

room 15.

  After running in, the pressure in the chamber 12 is removed and placed in the chamber 13, which immediately causes the piece 6 to rise,

  this one taking again the position of Figure 1.

  The fluid bearing 3 stiffens the spindle line Indeed, if at the time of centering of the spindle and the workpiece, the axis of the spindle tilts, this would produce a defect of perpendicularity between the reference face of the workpiece and the axis of the spindle and this ratio would end up after machining It's the part

  1 which focuses on the rod 2 and not the other way around.

  It goes without saying that the present invention should not be considered as limited to the embodiment described and shown, but covers, on the contrary,

all variants.

  6 - 3 t Sc_ RL P-ri 1 Device for holding a part to be honed during its break-in, which comprises a fixed support piece (5), a bearing piece (6) movable relative to the first in the lapping direction and means for clamping the lapping piece (1) between the movable support piece and the fixed support piece, characterized in that it comprises means (14) for

  pre-tighten the workpiece.

  2 Device according to claim 1, characterized in that the pre-clamping means are constituted by means (14) for limiting the

  moving the movable support piece (6).

  3 Device according to claim 2, characterized in that the movable support piece (6) is movably mounted in a part (7) fixed during break-in. 4 Device according to claim 3, characterized in that the means for limiting the displacement of the movable bearing part (6) comprises a ring (14) interposed between the fixed part (7) and the movable support piece (6). ) movable relative thereto and forming a stop for this piece

mobile support.

  Device according to claim 3 or 4, characterized in that the movable support piece has a portion (6a) in the form of a piston -7 delimiting between itself and the fixed part (7) two chambers (12 and 13) in which can be admitted a fluid under pressure, thus constituting the means

  of displacement of this movable support piece.

  6 Device according to claim 4 or 5, characterized in that the means for moving the ring comprise two chambers (13 and 15) located on either side thereof and in which a fluid under pressure can be admitted, these chambers being limited by one face of the ring (14), the

  fixed part (7) and / or the moving part (6).

  Device according to claims 5 and 6,

  characterized in that the means for moving the movable support member (6) and the means for moving the ring (14) have a common chamber (chamber 13).

  8 Device according to one of claims 3 to 7,

  characterized in that it comprises means for

  height adjustment of the fixed part (7).

  9 Device according to claim 8, characterized in that the height adjustment means of the fixed part (7) comprise: a shaft (10) having surfaces connected by slopes (la) and on which can support a part the fixed part (7); means (11) for moving the shaft (10) and return means (9) for the fixed part (7) in

direction of this tree (10).

  -8- Honing machine comprising a grinder (2) mounted on a spindle (4) and a device for holding the workpiece (1), characterized in that this device complies with

  any of claims 1 to 9.

  11 Machine according to claim (10) characterized in that the pin (2) is held by a fluid bearing (3) located in the vicinity of the

piece to be honed (1).