FR2483277A1 - Cutter for descaling round bar - uses cutters on length-adjustable radial slides displaced simultaneously by rotation of ring relative to bed - Google Patents

Abstract

The machine head uses radially adjustable cutters (6) to descale metal bars of round section, adjustment of all tools being effected simultaneously by a micrometric screw. A radially elongated slide (2) comprises the tool-holder, being fixed slidably to a stop block (9). A radial screw jack (10) permits the effective radial length of assembly (2,9) to be adjusted, with a locking screw (11) for fixing. A block (9) bears (13) externally on the non-tangential flat face of an inset (14) in a movable ring (4), and the latter is capable of rotation about the axis of a circular support plate. Small ring rotations effect radial tool (6) adjustment and the guide (14) may accommodate up to 5 degrees of ring movement.

Description

PEELING EFTE WITHOUT BAR AND TIRE CENTER
The invention relates to the field of centerless peeling of circular bars and tubes.

The problem posed is that of the equipment of old peeling machines which only allow low feeds of bars and require long, expensive and individual adjustments of each cutting tool, similar to modern machines whose feed speeds are very high (up to 50 m / min) with reduced unproductive times.

The adaptation to these old machines of the peeling head according to the invention described below makes it possible, for a relatively reduced investment, to make them competitive both in the fields of production, of ease of implementation and precision of the results obtained.

The peeling head according to the invention essentially comprises - a circular support plate on which the tools are mounted and
tool holders - the tool holders are mounted radially and can slide in this
meaning ; they are deduced from each other by a rotation of 2N
N being the number of tool holders used - the ends of the tools, generally made of sintered hard metal, coated
or not of a hard layer, are on the same circumference which
defines the machining diameter of these tools - each tool holder has a variable and adjustable length thanks to
a simple system of two sliding elements one compared to
the other and lockable in a specific position - all tool-tool holder assemblies are individually removable
and immediately kept on the # upport tray thanks to a stop
elastic ball attached to the plate which comes into contact with a
corresponding housing of the tool holder - a circular crown, movable in rotation relative to the plate
support, has N flat guides regularly arranged on its periphery
and which make an angle a with the direction perpendicular to the axis
longitudinal of the tool holders. These flat guides are made of hard metal
on each of them is supported a hard metal ball brazed on the back stop of the tool holder. The angle a is generally between 0 and 50.

This crown is positioned in a fine manner using a straight groove te, the direction of which is approximately 450 from a radial direction, associated with a stud fixed to a movable part in radial translation using 'a' micrometric 'type screw.

This device allows the simultaneous adjustment or compensation of tool wear, without any intervention on the tools or tool holders themselves, by operating the microinetric screw. The position accuracy of the tools during machining is around 1/100 mm.

The invention will be better understood using the drawings below, relating to a peeling head comprising four tools - Figure 1, a partial plan view of the peeling head, - Figure 2, a partial section according to II-II (figure 1) of the door
tool, - Figure 3, a partial section along III-III (Figure 1) of the system
fixing the crown, - Figure 4, a partial section of the adjustment system and positions
ment of the crown according to IV-IV (FIG. 1), FIG. 5, the diagram of the cut-out template for the tool holders.

These represent an embodiment in no way limiting the scope of the invention.

The support plate (1) is provided with four tool holders (2) centered on the axis of rotation (3) and a movable crown (4).

The tool holders (2) are guided on the plate by means of slides in bored with screwed sectors (5) which allow the radial movement of these.

The hard metal tools (6) are mechanically fixed using a clamp (7) and screws (8), the clamp also acting as a chipbreaker.

The tool holder (2) is secured to a rear stop (9) by means of an adjustment screw (10) and a locking screw (11). At the base of this rear stop, there is a ball pawl (12) and a hard metal ball (13) fixed by brazing, for example. This rests on the blank of the hard metal guide (14) fixed by a screw (15) in a housing t16) of the crown (43. The crown (4) is movable in rotation relative to the support plate (1) and is fixed thereto by means of buttonholes (17) containing the head of a plunger (lily) fixed by a screw (19). The precise rotational movement of the crown (4) is obtained by the radial displacement of an adjustment tenon (20) provided with a lug (21) using the screw (22) which advances in the tapped hole (23)
The lug (21) engages in the groove (24) located at the base of the crown (4). th circular clearance (25) located at the edge of the crown allows a large angular displacement of the latter when the lug (21) is sufficiently displaced towards the outside. This possibility is taken advantage of for the rapid assembly of the tools on the plate, the notches (26) of the crown (4) then being located to the right of the tool holders (2)
Thanks to the possibility of adjusting the length of the tool holders, the same peeling head covers a range of diameter approximately three times larger than for old heads. As a result, the number of heads required is greatly reduced. Thus, for example, a head can machine bars ranging from 20 to 80 minutes, whereas, on old machines, three heads were necessary to cover this range: 20-40, 4n-óo and 60-80 mm.

Furthermore, one or more sets of tool holders can be prepared intended to replace a set in use, during the work thereof, either for machining at the same diameter or for a different diameter; this considerably reduces the downtime for adjustment and installation.

The quick change of tools on a head is done as follows - loosening of the locking screws of the plungers (19), - positioning of the tenon (21) in line with the notch (25), - rotation by hand of the crown (4) to bring the notches (26) into
face of the tool holders (2), - radial withdrawal of tools and tool holders, - installation of new tool holders of pre-set length, - reverse operations from above, - restarting.

Precision adjustment using the screw (22) occurs in cases where
- we want to compensate for wear of the cutting tools,
-We want to vary the diameter of the bars slightly.
tees.

The length of the tool holders is preset using a template which includes a base (61) carrying a stop (614) which has, relative to the tool-tool holder assembly, the same geometry as the peeling head. This template is provided with a comparator support (62) and a comparator (63) which therefore makes it possible, by positioning the tool-tool assembly in the template, to identify the exact length and to adjust it. precisely by acting on the screw (10).

Claims (2)

RIA ~ NDICATIONS 10 / - Machining head for peeling of bars and tubes comprising a circular support plate (1), tool holders (2), mobile and adjustable in a radial direction and integral with a rear stop (9) which s 'supports: .. on flat guides (14) integral with a movable ring (4) around the axis (3)' of the support plate (1), characterized in that the length of the tool holder is variable and preset. 20 / - Machining head according to claim 1, characterized in that the fine adjustment of the machined diameter is made simultaneously on all the tool holders by means of a slight rotation of the crown (4) 30 / - Head of machining according to claims 1 or 2, characterized in that the planar guides make with the tangential direction relative to the radial displacement of the tool holders, an angle a between 0 and SO.