FR2666388A1 - TOOL HOLDER FOR A PRESET APPARATUS. - Google Patents

Abstract

The present invention relates to a tool holder for a presetting apparatus or the like, consisting of a conical bushing (2) which, receiving the tapered shank of a tool, is rotatably retained in a sleeve (3) integral with the frame being supported by thrust bearings and radial load (4, 5a, 5b). Despite a technically complicated combination of thrust bearings and radial load assembly is sufficiently free of play is not assured. In order to obtain a highly accurate assembly of the conical bushing (2) in the sleeve (3), it is provided according to the invention that at least the radial load bearing (5a, 5b) is made from a resin pourable material (7) which is injection molded in a hollow space (6) bounded by the sleeve (3) and the conical sleeve (2) placed therein.

Description

Tool holder for a presetting apparatus The present invention relates to

  a tool holder for a presetting apparatus or the like, consisting of

  a conical bushing which, receiving the conical tail of a

  til, is restrained so that it can rotate in an oven

  integral with the frame being supported by bearings

stop and radial load.

  In the field of CNC machining tools, accurate dimensions are required

  concerning the position of the tool edge both by

  port to a predefined zero plane (height) only relative to the axis of rotation of the tool (diameter) To determine these dimensions of height and diameter are used so-called presetting devices They consist of a base frame in which is mounted on a receiving axis perpendicular thereto, a tool holder capable of

  turn The base frame also has a vertical column

  with a mounted height measuring device

  height and a diameter measuring device.

  The tool is set in the tool holder and then the height of the tool edge above the zero plane and the diametrical position of the tool edge relative to the tool axis is determined by the intermediary

  Thus, the diameter, the concentration

  tricity and height of milling, drilling and

  boring and this also for machines other than that

the numerically controlled.

  To allow a low tolerance presetting

  the tool holder, in particular the mounting of the sleeve

  rotary shaft receiving the tool shank, must absolutely be of high dimensional accuracy.

  means of an oblique roller bearing, so far practically

  ticated in this area, is technically complicated and therefore

  costly and admitted nevertheless, especially after a certain

  duration of use, games to a degree that they translate into considerable dimensional tolerances

parts to be machined.

  The present invention aims to improve a tool holder of the kind mentioned in such a way that a technically simple assembly, a long life and

  high accuracy of the rotating conical bushing is achieved

bare.

  This goal is achieved with regard to a

  tool for a presetting apparatus or the like, constituted by a conical bushing which, receiving the conical tail of a

  tool, is retained so that it can rotate in an oven

  integral with the frame being supported by thrust bearings and radial load, in that at least the (s)

  Bearing (s) with radial load consists of a resin containing

  hardened, injection molded in a hollow space

  mended by the sleeve and the conical bushing placed in the latter. It is only after the insertion of the conical bushing in the sheath and when it bears on the thrust bearing that the bearing with radial load is formed in

  medium of pourable resin injected into a cavity hollow cor-

  respondant Thus the bearing with radial load adapts precisely to the conditions existing when the bushing

  taper is in place, so that games can be

  otherwise, because of dimensional tolerances, the surfaces of the radial and abutment bearings are reliably avoided. Surprisingly, it has been found that the radial load bearings obtained from a castable resin the trade had a long life and even after a period of use

  extended, they did not show increased radial clearance.

  According to another characteristic of the invention, the aforementioned hollow space is in communication with a channel

  filling and with an overflow channel.

  In an advantageous embodiment of the tool holder of the invention the peripheral surface of the conical bushing bearing against the bearing obtained at

  from castable resin is coated with a material

  friction, preferably Teflon. The separation surface between the radial load bearing obtained from

  of castable resin and the conical bushing is advantageous

  lubricated with grease, in which case it is

  preferably a lubricating channel leading to the

  separation face and constituted in particular by the channel

  overflow made by boring.

  In another advantageous embodiment of the invention there is provided between an annular abutment shoulder of the tapered sleeve and a corresponding annular shoulder of the sleeve a thrust bearing supporting the

  axially conical bushing, in particular a rolling bearing

  which is arranged between a bearing with radial load su-

  and a lower radial load bearing.

  Another advantageous characteristic of the invention

  The outer circumferential surface of the conical bushing bearing against the radial load bearing and the inner circumferential surface of the sheath opposite the outer peripheral surface tapers slightly conically towards the respective lower ends of the bushing. cone and sheath, the cone angle of the narrowing being

  preferably substantially less than one degree.

  In a particular embodiment of

  the invention the hardened cast resin forms a

  a radial load / stop and the conical bushing is preferably in the form of a pin capable of

to be trained.

  In a method according to the invention allowing a conical bushing forming a tool holder to be rotatably mounted in a sleeve integral with the frame, described above, a release agent is applied in

  a layer 2 to 3 μm thick on the perimeter surfaces

  of the conical bushing limiting a hollow space forming a bearing, then the conical bushing is placed in the sheath, while enough material is removed from the annular abutment shoulder of the conical bushing, facing the thrust bearing, so that the tapered sleeve is placed without play in the sleeve, then

  each hollow space is filled with castable resin by the

  intermediate of a filling channel until the

  cast resin from the overflow channel and after

  curing of the castable resin, the release agent is

  removed from the peripheral surfaces of the conical bushing.

  Instead of the release agent it can be applied to

  to be permanent a layer of material reducing the friction

  Teflon or the like, on

the conical bushing.

  Advantageously, the overflow channel is

  green by drilling to the separation surface between the castable resin and the peripheral surface of the socket

  taper and lubricating grease is brought to the surface.

  this separation through a threaded connection of grease

wise and by the overflow channel.

  The invention is explained in more detail below.

  under by means of exemplary embodiments illustrated in the drawings

  annexed drawings in which: FIG. 1 represents a sectional view through

  the base frame of a presetting device equipped with the

  tool tool made according to the invention; Figure 2 is a top view of the base frame of Figure 1; Figure 3 shows a section through the sleeve of the tool holder; Figure 4 shows a section through the tapered sleeve of the tool holder; and

  FIG. 5 represents an axial section of a

  an exemplary embodiment of a tool holder with a sleeve

  the conic made in the form of a pin likely

to be trained.

  The rectangular base frame 1 shown in FIGS. 1 and 2 has at one of its ends

  a tool holder 10, while at the opposite end is

  view a receiving opening 16 extending perpendicular-

  The column 15 is fixed by means of screws, without play, to the base frame and to accommodate a column 15 shown in Figure 1 in phantom.

  measuring instruments, not especially representative of

  The receiving opening is located on one side of the longitudinal central axis 17 of the base frame 1, which comprises the other side of the longitudinal center axis 17 of the base frame 1, which comprises the other side of the longitudinal central axis 17 at the end 14 a base flange 18 which has a hole 19 for fixing the base frame on

a table or the like.

  At the other end 13 of the base frame 1 is

  seen in the narrow front wall a recess 40 located

  above a vertical hole 41 provided in the front wall.

  Thanks to the recess 40 a fastener passing through the hole 41 can be tightened so that the base frame 1 can be secured at its two ends 13 and 14

on a base plate.

  The frame 1 preferably made of cast iron has at its end 13 a parallelepipedic superstructure 50 with a central cylindrical receiving bore 51 whose vertical axis 52 is, in the top view of FIG.

  2, on the longitudinal central axis 17 of the base frame 1

  the laceration 51 serves to receive a sheath 3 that can be put in place in an adjusted manner and which is supported at the level of the

  cover plate la of the base frame 1 on a shoulder-

  1 of the base frame 1. For this purpose the furnace

  cylindrical water 3 has at its lower end 32

  disposed at the cover plate the one

  33 of reduced diameter so as to have, at the step thus formed, an annular front surface 34 which bears on the shoulder lb of the base frame 1 The portion 33 of reduced diameter is arranged with a certain clearance in a bore continuous cylinder 1c of the base frame 1, which bore follows the receiving bore 51 of the

superstructure 50.

  The sheath 3 is received in the superstructure 50 such that its outer annular front side

  is in the same plane as the upper frontal

  In this respect the dimensional tolerances are chosen so that by a removal of material from the front surface 34 of the sheath 3

  bearing on the shoulder lb the depth of engagement

  is adjusted in such a way that the front side 35

  located in the same plane as the frontal side 53.

  The sleeve 3 represented, as an element

  axial section in Figure 3 shows a first

  first cylindrical bore 36 following the front side

  35 and which in turn follows a cy-

  lindrique 37 of reduced diameter, which crosses the part

33 of reduced diameter.

  At the level of the diameter change, an annular shoulder 30 is formed inside the sheath 3 which serves to support a thrust bearing 4 made as a rolling bearing 12 (FIG. 1).

  bearing 12 at its outer periphery the sur-

  peripheral face 38 following the annular shoulder

  in the cylindrical bore 36 is machined accordingly.

  The inner circumferential surface 31b in the end portion 33 of the sheath 3 is designed to taper conically towards the end 32. The cone angle 39 is extremely small and substantially less than one degree. It can therefore be assumed that the peripheral surface slightly conical 31 b is unlikely to

axial load.

  The inner peripheral surface 3 la which at the outer end of the bore 36 is contiguous with the front side 35 also extends slightly conically,

  the cone angle 39 corresponding to that of the surface

  Rectangle 31b Between the upper peripheral surface 31a and the peripheral surface 38 of the bore 36, adjacent

  the annular shoulder 30 is provided a clearance.

  In the peripheral surface 31a following the

  front side 35 of the sheath 3, as in the perimeter surface

  31 b provided in the lower end portion 33, is formed by dive turning an annular groove extending over the entire periphery and which in the embodiment shown is, in section, rectangular The annular groove 60 forms a hollow space 6 who is in

  communication with a radially

  8 each of the two filling channels 8 are

  at the axial end of the groove 60 located on the lower end 32 of the sleeve 3, whereas a channel

  continuous overflow 9 arranged radially leads to

  calf from the other end of the groove 60.

  In the wall of the sheath 3 is provided roughly

  at mid-height of the inner cylindrical bore 36 a

  3 a through which it can be radia-

in bore 36.

  As shown in FIG. 1, a conical bushing 2 having a stepped outer diameter is placed in the cylindrical receiving bore 36.

  transition from the smaller diameter part 23 to the

  29 of larger diameter is formed an annular shoulder

  axial wheel 20 which bears on the thrust bearing 4.

  A first peripheral surface 28 following the

  annularly 20 bears against the inner wall

  thrust bearing 4 so that the thrust bearing is

  held radially securely between the peripheral surface

  38 of the sheath 3 and the peripheral surface 28 of the

conical bush 2.

  The conical bushing is magnificently

  die in axial section in Figure 4 sees its diameter still

  once reduced at the free end of the

  part 23, the peripheral surface 21b narrowing co-

  in the direction of the lower end 22 of the portion 23 The cone angle 39 a corresponds in this respect to

  the cone angle 39 of the peripheral surface 31b of the furnace

water 3.

  The outer peripheral surface 21a following the front side 25 of the portion 29 also extends narrowing under a corresponding cone angle 39a

  at the cone angle 39, towards the lower end

  22 of the conical bushing 2 The axial extent of the over-

  peripheral face 21a and the peripheral surface

  21b corresponds in this case substantially to the perimeter surfaces

  Inner pheasants 31a and 31b of the sheath 3 (FIG. 3).

  In the conical bush 2 there is provided a cone

  cepteur 24 for the taper shank of a tool not shown.

  The receiving cone 24 has an upper annular contact zone 26 and a lower annular contact zone 27 against which the tool shank bears when the tool is in place. The receiving cone 24 is

  extended at its narrowed end by a cylindrical bore

drique crossing 24 a.

  The conical bushing 2 placed in the sheath 3

  leans axially through the roller bearing

  12 on the annular shoulder 30 of the sleeve In order to obtain the desired slot of 2 to 3 g between the facing peripheral surfaces 21a, 21b of the conical bush 2 and

  31a, 31b of the sheath 3 it is applied to the surfaces

  2 a and 21 b of the conical bushing 2 a layer of corresponding thickness of a release agent After introduction of the tapered sleeve 2 in the sleeve 3 he

  sufficient material is removed from the annular shoulder.

  20 so that the conical bushing 2 is retained without play in the sheath 3 and closes the hollow spaces 6 to a large extent in a sealed manner. Furthermore, the tolerances are preferably provided in such a way that the conical bushing 2 located correctly in the sheath 3, the front side 25 of the conical bushing 2 is substantially in the same plane as the front sides 35 and 53. Through the filling channels 8

  the cavities 6 are filled with pourable resin 7

  that the latter comes out through the

  overflow channels 9 Since the perimeter surfaces

  2 and 21 b of the conical bushing 2 coated with release agent seal hollow spaces 6 tightly, penetration of the liquid resin between the sleeve and the conical bush is largely excluded. After curing the flowable resin 7

  conical bushing 2 is axially extracted and, in a first

  In the first embodiment, the release agent is removed.

  This layer may for example be Teflon and corresponds in its thickness substantially to 2 to 3 g of the layer.

release agent removed.

  In another embodiment, the demolding agent is simply removed and the conical bush 2 is engaged axially in the sheath 3. The slit remaining between the surrounding peripheral surfaces in the region of the radial load bearings 5a and 5b formed by the flowable resin 7 is filled with pressurized lubricating grease. To this end, the overflow channel 9 is pierced to the separating surface 11 between the sleeve 1 and the conical bush and is located once the

  sheath 3 put in place in the superstructure 50, in

  communication with a threaded grease nipple 54 which is

  fitted into the wall of the superstructure 50.

  To adjust the slot of the bearings with radial load a and 5 b it must be ensured that the conical bushing 2 can dive sufficiently deep into the sleeve 3 A

  this end it is planned to perform at the level of

  the annular shoulder 30 of the sheath 3, which carries the thrust bearing 4, to the peripheral surface 31b in the

  end portion 33, a clearance 30a With this release

  30 to the peripheral surface 28 of Part 23 of di-

  reduced meter, which surface follows the shoulder

  annular 20 of the conical bush 2, can cross axial-

  the annular shoulder 30 of the sheath 3.

  Opposite the opening 3a in the sleeve 3 is in the superstructure 50 a tapped hole 55 in which can be screwed a clamping screw 70 preferably made of synthetic material The front end of the threaded rod 71 can thus be brought in contact with the conical bushing 2 in order to immobilize it in a fixed manner in

rotation (Figure 1).

  In the embodiment of FIG. 5, a sheath 300 is retained in a base plate 1 O O a

  sheath is made substantially in the form of a man-

  cylindrical chon with a top flange 301 which is

  fixed on the base plate lo O a by means of screws.

  The conical bush made in the form of a spindle 200 and having the receiving cone 400 has a substantially cylindrical base shape and has at its two ends respectively a conical portion 201; 202 whose vertices are turned towards the lower end

of the conical bushing 200.

  In the assembled state, the pin 200 is in the sleeve 300 in such a way that the conical portion 201 limits, with the sheath 300 and an annular disc 321 screwed onto the lower end 320 of the sheath, a hollow space 600 which, by way of intermediate of a filling channel

  800 is filled with castable resin 700

  ble is introduced under pressure into the hollow space 600 until it comes out through the channel of

overflow 900.

  Similarly, the conical portion 202 limits

  with the sheath 300 and a ring 302 of synthetic material

  that which closes the slot between the conical bushing 200 and the sheath 300, a hollow space 600 which also

  has a fill channel 800 and an overflow channel

  not shown The upper hollow space 600 is

  analogously, filled with pourable resin 700.

  The cone angle of the conical portions is chosen such that the formed bearing constitutes a combined bearing with radial load and abutment. The cone angle 390 of the conical portion 201 is in this case about 200,

  whereas the cone angle 391 of the upper conical part

eure 202 is around 450.

  As in the embodiment of FIGS.

  at 4, the conical surface bearing on the resin

  700 may be provided with a layer which reduces friction

  the surface of separation between the resin

  lable 700 and the conical bushing 200 can be filled with pressurized lubricating grease via

lubrication channels.

  The conical bushing 200 in the exemplary embodiment

  5 shown in FIG. 5 is formed as a drivable pin, which is why

  it is attached to the bottom end of the bushing

  200 tree end 221 On the end of the tree is

  fixedly rotates a pulley 222 which is

  dragged through a control mechanism to

  belt 223 not shown The pin 200 capable of being

  be driven at any desired speed is therefore used to control the concentricity of a tool retained in the cone

receiver 400.

  According to an advantageous development of the invention it is fixed to the upper free end of the conical bush 200, by means of an L-shaped retaining ring 401, a seal 402 which prevents any penetration of dirt into the slot between the sleeve 300 and the socket

conical 200.

Claims (6)

1 a tool holder for a presetting apparatus or the like, consisting of a conical bushing (2) which, receiving the tapered shank of a tool, is held so as to be able to rotate in a sleeve (3) integral with the frame; being supported by thrust bearings and radial load bearing (4; 5a, 5b), characterized in that at least the radial load bearing member (s) (5a, 5b) ) consists of a cured casting resin (7) injection molded in a hollow space (6) limited by the sleeve (3) and the conical sleeve (2) placed therein.   Tool holder according to claim 1, characterized   characterized in that the hollow space (6) is in communication with a filling channel (8) and an overflow channel (9).   3 Tool holder according to claim 1 or 2, characterized in that the peripheral surface (21a, 21b) of the conical bush (2), which bears against the bearing (5a, 5b) based on resin castable, is coated   to reduce friction, preferably teflon.   4 Tool holder according to claim 1 or 2, characterized in that the separating surface (11) between the pourable resin bearing (5a, 5b) and the conical bush (2) is lubricated with grease. , a channel of   lubrication constituted in particular by the overflow channel   solid (9), made by boring, preferably leading to the separation surface (11).   Tool holder according to any one of the   previous indications, characterized in that between a   ring (20) of the conical bush (2) and a shoulder   corresponding ring (30) of the sheath (3) is   a bearing (4) supporting the conical bushing (2)   in particular, a rolling bearing (12) which is located between a bearing with an upper radial load (5 a)   and a lower radial load bearing (5b).   Tool holder according to any one of the preceding claims, characterized in that the outer circumferential surface (21a, 21b) of the conical bush (2) bears against the radial load bearing (5a). , b), as well as the opposite inner circumferential surface (31a, 31b) of the sleeve (3) tapers slightly from   conically towards the lower extremities res-   pectives (22; 32) of the conical bushing (2) and the sleeve   (3), the angle of the cone being preferably substantially less than one degree.   7 Tool holder according to any one of the   preceding claims, characterized in that the resin   cured lable (700) constitutes a combined bearing with reduced load   end stop (45) and in that the conical bushing (200) is preferably designed as a spindle to be trained.   8 Method enabling a conical bushing (2)   forming tool holder to be mounted so as to be able to   in a sheath (3) secured to the frame according to one   any of the preceding claims, characterized in that   what on the peripheral surfaces (21 a, 21 b) of the   conical bushing (2), which limit a hollow space (6)   bearing layer is applied a layer of release agent with a thickness of 2 to 3 pm, in that the conical bushing   (2) is placed in the sheath (3), sufficient material   being removed from the annular shoulder (20) of the conical bushing (2) facing the thrust bearing for   that the conical bush (2) is without play in the furnace   (3), in that each hollow space (6) is filled with   casting resin (7) via a filling channel   pleating (8) until castable resin exits the overflow channel (9) and that after curing   the castable resin the release agent is removed from the   peripheral faces (21a, 21b) of the conical bushing (2). Process according to Claim 8, characterized in that, in place of the demoulding agent, a friction-reducing layer of Teflon or the like is permanently applied to the peripheral surfaces.   (21 a, 21 b) of the conical bush (2).   Process according to claim 8, characterized   in that the overflow channel (9) is opened by   to the separating surface (11) between the flowable resin (7) and the peripheral surface (21a, 21b) of the conical bush (2) and that via a threaded connection of greasing (54) and the overflow channel (9) of the lubricating grease is brought to the surface of separation (11).