DE1577393A1 - Axially displaceable center point with automatic clamping - Google Patents

Description

Axially movable centering tips with automatic clamping.

Description.

Se face drivers have become known in which Move driving pins or surfaces independently of the center point when they are pressed against the face of the workpiece will. German interpretation 1 129 & Oj5> German application L 50 292 Ib / b? a or the French patent specification 1 19S b? 0. In the latter, the brake shafts are swash plates pressed axially against the face of the workpiece. This makes it possible for the center point in particular to be fixed as a "dead point" without its own rotation during cylindrical grinding. so that the highest smooth running accuracy of the workpiece can be achieved during machining Use the brake discs to push the workpiece out of the centering point on the headstock side. The necessary accuracy in the centering is not retained * In the present application this deficiency is eliminated

List of figures.

Fig «1. Face drivers with mechanically moved brake discs with axially movable center point.

Fig. 2. Front view of the driver of Fig.1 ₉ topless driving surfaces ₀

Fig. 3ο Cross section through the tip carrier unfl. the center point with straight!

Fig 4. View of the | enticing tip according to Fig.3.

Fig. “5. Cross-section through the tip carrier and the centering tip with inclined grooves.

Fig · 6 »View of the centering point for Fig · 5.

Fig * 7 · cross £ fc] iii1; l through the tip support with »inset Segmented.

Fig. 8 Driver housing for revolving center point «

An end face driver according to French patent 1 198 b70 is chosen as an example of the application of the center point developed.

BATHROOM 0Q9830 / U484

On the bed 1 of a cylindrical grinding machine, the work piece is clamped between the tips Drive received, fastened. In a housing 5 there are 2 ¹ SaXX melrings b, which can be moved through a cap 7 via a steering 8 (Fig. 2) The driver carrier 11, which is triggered by a band brake 10 and which is connected to the wobble rings b and which carries driving surfaces 22 made of plastic at the front in the example, is thereby pressed forward, so that the driving surfaces 22 press against the face of the workpiece 3 Pressure Q (Fig. 1), which creates a tangential frictional force ^ UQ and so the workpiece. 3 set in rotation by the resulting torque H » (Fig-3J In the older version, as a result of the deformation and flexibility of the workpiece 3 and the forces Q vaujBjd ^ r ^ centering,. ^ 'The workpiece 3 / pressed out into the - exaggerated 3sx £ S - dashed line, and there is play between the centering point 4 and the centering cone of the workpiece 3 The necessary precise flange run is thereby endangered To prevent this, the centering point 4 is inserted in the sliding seat in the tip carrier 12 This itself rests in the usual way, e.g. by an Iforse cone in the fixed axis 13 of the Oandschleimaschine line compression spring 14 in the bore of the tip carrier 12, which is formed in Fig. 1 by rope springs , acts on the bottom surface of the centering point $ 4 and thereby presses it into the centering hole of the workpiece 3, so that the relationship between the centering point and the workpiece is maintained, too when the workpiece is pushed back "

However, this requires the center point to be able to move axially 4 a play between the outer diameter of the shaft of the triar point 4 and the inside diameter in the bore of the tip holder »12 ·

BATH

009830/0484

Baeh. the clamping of the workpiece 3 and before the start of machining bmB, however, the center point 4 in the point carrier 12 are completely backlash-free and clearly fixed Longitudinal grooves 15 evenly distributed on the circumference wa 120 °, ^ Λul _t have a constant semicircular cross-section running in the axial direction, while on the ylindri-see AmBcmourviiBesear of the centering point 4 perpendicular to the longitudinal 15 standing transverse grooves 1b are attached are also in 3 legs * offset by 120 ° (Fig. 4) In the example shown in Figs. 1 and 4, 3 such transverse grooves are provided in each of the three legs Radius like the longitudinal center. In the curvature of the circumference at the centering point 4, the depth of the piftminutes 1b decreases after both seldom.In each intersection point reu LKmgsnutem 15 and transverse grooves 16 there is a ball 17, the deepest point of which is the deepest point of the lay groove and its innermost point in the βαΐΐ-st hurry ale touches the deepest point of the Qaemut. The necessary axial tereehiebuag of the lemtsierspltze 4 when clamping the workpiece is possible because the ball * 17 can move axially in the longitudinal grooves 15. If the workpiece 3 is now set in rotation by the take-up surfaces 22, the torque M (Fig.5) acts on the centering point 4. As a result, it rotates through a small angle and the transverse grooves assume a different position, as for the top one In Fig. 3 is shown by the knitted unIe · The balls 17 are clamped in their transverse groove 15 Ia the flatter, tapering cross-section · By this clamping of the balls 1? the necessary unambiguous definition of the centering point 4 is created with a certain Torspannumg, so that the condition of the fixed centering point - the "dead" point - is fulfilled during processing.

In the embodiment according to Fig.5 and b, the transverse grooves 1b are diagonally against the Aeherlch- with the same shape -tan lingsmuten 15

009830/0484

f '15 ^ 7393

made. According to Figure "b then the ümfangakraftYdts 3 acting torque M results as shown in Fig. For centering an additional axial force component F ₉ through which the ^J ederdruclt the 'edern is amplified 14 · In the embodiment of fig B, the axially compressive coil spring 14 at the same time designed as a torsion spring, while one bent end is in the tip carrier 12, while the other end is fixed in the centering tip 4. return. Feiler springs for axial pressure and a helical spring can also be installed as a torsion spring, the forces of which can then be selected independently of one another. In the embodiments, the legs of the transverse grooves are always axially offset from one another in order to facilitate the insertion of the centering point 4 into the point support 12 during assembly.

In Fig. 7 the longitudinal grooves 1b for the balls 17 are formed in order to facilitate the use of hardened parts in that 3 cylindrical segments 21 are screwed into the tip _{carrier 12}} the bevelled ends of which form frame guides for the balls 17.

As can be easily seen, through into the tip carrier 12 screwed-in segments are also formed in this transverse xrate will. Then the center point 4 receives the axially running longitudinal grooves · The same clamping of the center point in the point carrier is achieved ·

The arrangement made primarily for flange grinding machines according to Fig.1 stm grinding with "dead" tips is simplified as shown in Fig. 8 when the center point 4 should also run at the speed of the driver housing 5, as · ζ · Β · on lathes. Then the housing (5 of Fig. * 1) can be combined with the tip carrier (12 of Fig. 1} to form a single piece, the bearing housing 19 of Fig. 8 · To the rear, the bearing housing carries the Morse taper for shaft 13 and in the extension to the front is the centering point * ■ ** ^ ⁶¹ * grooves 15 and 1b, as well as the balls 17. The difference in speeds when starting up between the workpiece and the housing causes the centering point 4 to be clamped by the balls 1? as before.

009830/0484 BAD O ^ nal

Claims (1)

T577393 Claims · Annex Z Claim ^ 1y center point wi an end face driver, ie the driving pins or driving surfaces coming to rest on the face of the workpiece ^) are moved independently of the center point {* ή , characterized in that the in a point carrier / 12, 19) inserted shaft of the centering tip (4) transverse grooves are h , which run perpendicular to the axis direction or at an angle to it that is greater than 0 °, and which are arranged in rows distributed symmetrically to the circumference, during the The tip carrier (i2j in a bore with longitudinal grooves (i 5) which are fixed to the shaft (13) and the number of which corresponds to the number of transverse grooves, with 4 balls at the intersection points between the longitudinal and transverse rows (17) is inserted Claim 2 «centering point near claim. 1 characterized in that its own of the transverse grooves en (ib) against each other are offset MD 009830/0484 Blank page