GB2052336A

GB2052336A - Adjustable holder for boring bars and axial tools for vertical lathes

Info

Publication number: GB2052336A
Application number: GB8018565A
Authority: GB
Original assignee: Tovarny Strojirenske Techniky
Current assignee: Tovarny Strojirenske Techniky
Priority date: 1979-06-08
Filing date: 1980-06-06
Publication date: 1981-01-28
Also published as: GB2052336B; IT1149973B; YU150780A; YU41715B; PL124038B2; FR2458341B3; IT8022598A0; RO81492A; FR2458341A1; PL224805A1; CS211751B1; DE3021409A1; SU1038087A1; RO81492B

Abstract

A holder 10 for boring bars and axial tools for vertical lathes enables an accurate centering of the axis its clamping opening with the axis of the workpiece. Positioning keys 20 are provided with inclined faces 21, which engage inclined holder faces. The positioning keys 20 are movable along non-inclined grooves 22 in the clamping face 60 of the machine tool by positioning screws 40, and guide elements 50 fixed to the holder 10 engage in a groove 62 in the clamping face 60 perpendicular to the grooves for the positioning keys. The movement of the keys 20 moves the holder 10 along the "y" axis, the holder being subsequently bolted 70 to the clamping face 60. <IMAGE>

Description

SPECIFICATION Holder for boring bars and axial tools for vertical lathes The invention relates to a holder for boring bars and axial tools for vertical lathes enabling an adjustment of the axis of the boring bar or axial tool with respect to the axis of the workpiece.

Known holders for boring bars and axial tools do not enable a change of the position of the axis of the clamping opening of the boring bars or axial tools with respect to the axis of the workpiece. The coaxiality of the clamping opening of boring bars and particularly of axial tools is achieved by accurate positioning of the centering opening in the clamping face of the machine and by an accurate positioning of the clamping opening with respect to a positioning bolt on the clamping face of the holder, which fits into a centering opening in the clamping face of the machine, or by boring a clamping opening in a holder mounted on the machine by means of a tool clamped on the clamping face.The making of a centering opening and a clamping opening by boring on the machine is rather demanding and the coaxiality of the axial tool and the clamping face at different operating temperatures is thereby not achieved. A holder with a clamping opening made on a machine for which it is designed cannot be used on another machine even if it is of the same type and size. Thus similar holders are unsuitable for series manufacture.

According to the invention there is provided a holder for boring bars and axial tools for vertical lathes comprising a main body with a clamping face, at least one recess having an inclined side face, the recess receiving a positioning key formed with a similarly inclined face, the inclined face of the recess and the inclined face of the positioning key bearing on each other, a clearance "y" formed between a face of the recess opposite to the inclined face and the adjacent face of the positioning key, the positioning key engaging with its upper part in a groove in the clamping face of the machine tool, a slot in the positioning key extending parallel to the inclined face of the positioning key for an element connecting the positioning key to the main body, a cylindrical opening in the main body having a female threaded portion for an external thread of a positioning screw, the cylindrical portion of the opening receiving a cylindrical face of the positioning screw, a collar of the head of the positioning screw engaging a recess in the positioning key, guiding elements fixed to the main body, a groove for these guiding elements formed in the clamping face of the machine tool which is perpendicular to the groove formed in this face for the positioning key or keys, the main body being fixed to the clamping face of the machine tool by screws for which female threads are provided in the clamping face of the machine tool and oval openings in the main body.

By way of example, a specific embodiment in accordance with the invention will be described with reference to the accompanying drawings in which: Figure 1 is an elevation of a holder, partly in section, for boring bars or axial tools for vertical lathes; Figure2 is a side view of the holder of Figure 1; Figure 3 is a plan view showing the clamping face of the main body of the holder of Figure 1; Figure 4 is a section along the line A-A in Figure 1; Figure 5 is an enlarged detail view B from Figure 1; Figure 6 is an elevation of a positioning key of the holder of Figure 1; Figure 7 is a plan view of the positioning key of Figure 6; and Figure 8 is a section along the line C-C in Figure 6.

Referring to the drawings, two recesses 12, each inclined on one lateral face, are provided on the clamping face 11 of the main body 10 of the holder opposite to each other in the direction of the axis x, into which recesses 12 positioning keys 20 are inserted so that they bear by their inclined faces 21 with an inclination angle a against equally inclined lateral faces 13 of the recesses 12. A clearance y remains between faces 22 of the positioning keys 20 and faces 14 of the recesses 12. Upper not inclined parts of the positioning keys 20 engage in a groove 61 in the clamping face 60 of the machine tool.

Connecting screws 30 for fixing the positioning keys 20 in the adjusted position are screwed into the main body 10. Slots 23 are provided in the positioning keys 20 for the connection screws 30, which slots 23 are parallel to the inclined faces 21 to allow movement of the positioning keys 20 in the recesses 12 in the direction of the axis x. The positioning keys 20 can be shifted in the direction of the axis x by positioning screws 40 which are screwed into the main body 10 and which engage by their collars 43 in grooves 24 in the positioning keys 20.

The positioning screws 40 are guided in the main body 10 by their cylindrical shanks 42 engaging cylindrical counterbores 16 of screw threaded holes 17 for reception of the external threads 41 of the positioning screws 40. Fitted guiding keys 50 fixed by screws 80 in grooves 15 made in the main body 10 engage by their upper parts in a groove 62 in the clamping face 60 of the machine tool, which groove 62 extends perpendicularly to the groove 61 and serves for guiding the main body 10 when its position is adjusted with respect to the clamping face 60 of the machine tool and for transmitting a part of the torque for cutting forces. The main body 10 is fixed to the flamping face 60 of the machine tool by four screws 70 for which four oval openings, which allow a change of the position of the holder in the direction of the axis y, are provided in the clamping face 11 of the main body 10.

By screwing-in the positioning screws 40 into the main body 10 and by the movement of the positioning keys 20 in the direction of axis x, controlled by axial movement of the positioning screws 40, the position of the axis z' of the main body 10 with respect to the axis z of the clamping face 60 of the machine tool, is changed due to the inclined faces 13 and 21 by the value -y, so that the axis z' of the clamping opening takes the position Zí. On the other hand, by screwing-out the screws 40 the position of the axis s' of the main body 10 with respect to the axis z of the clamping face 60 of the main tool is changed by the value +y, so that the axis z' of the clamping opening takes the position z2,. The holder is fixed to the clamping face 60 of the machine tool by the screws 70 and its position may be adjusted within the limits iy.

An advantage of the holder for boring bars and for axial tools described above is that it enables adjustment of the axis of the clamping opening with respect to the axis of the workpiece, the adjustment being achieved by the inclined faces of the positioning keys controlled by the positioning screws. The adjustability of the holder enables inaccuracies of centering of the clamping face of the machine with the clamping plate to be eliminated and also deviations of coaxiality at different operating temperatures of the machine.

Moreover, the holder can be manufactured inde pendentlyfrom its machine on which it is to be used and is therefore suitable for series production.

Claims

1. A holder for boring bars and axial tools for vertical lathes comprising a main bodywith a clamping face, at least one recess having an inclined side face, the recess receiving a positioning key formed with a similarly inclined face, the inclined face of the recess and the inclined face of the positioning key bearing on each other, a clearance "y" formed between a face of the recess opposite to the inclined face and the adjacent face of the positioning key, the positioning key engaging with its upper part in a groove in the clamping face of the machine tool, a slot in the positioning key extending parallel to the inclined face of the positioning key for an element connecting the positioning key to the main body, a cylindrical opening in the main body having a female threaded portion for an external thread of a positioning screw, the cylindrical portion of the opening receiving a cylindrical face of the positioning screw, a collar of the head of the positioning screw engaging a recess in the positioning key, guiding elements fixed to the main body, a groove for these guiding elements formed in the clamping face of the machine tool which is perpendicular to the groove formed in this face for the positioning key or keys, the main body being fixed to the clamping face of the machine tool by screws for which female threads are provided in the clamping face of the machine tool and oval openings in the main body.

2. A holder for boring bars and axial tools of vertical lathes substantially as hereinbefore described with reference to and as shown in the accompanying drawings.