WO1985003659A1

WO1985003659A1 - Apparatus for fitting workpieces fastening pallets in a machine tool

Info

Publication number: WO1985003659A1
Application number: PCT/FI1985/000016
Authority: WO
Inventors: Pertti Kalevi Niemi
Original assignee: Oy Kontino Ab
Priority date: 1984-02-17
Filing date: 1985-02-15
Publication date: 1985-08-29
Also published as: FI840649A; EP0172861A1; FI840649A0

Abstract

The apparatus comprises a rigid, horizontal bed (5), fitted with a rotary table (11) which is adapted for rotation around a horizontal axis and provided with catch means (12, 13) for engaging one end of a pallet (14), said bed (5) being fitted at a distance from rotary table (11) and on its axial line of rotation (18) with a rotating centering plug (15) for engaging the other end of a pallet, a pallet to be replaced being fastenable between the rotary table and centering plug. As a pallet can be locked at any position around its lengthwise axis, the actual working can be effected in a more versatile fashion without removing, positioning and re-fastening of workpieces.

Description

Apparatus for fitting workpiece fastening pallets in a machine tool.

A generally used fastening means for mounting pieces to be worked in a machine tool comprises a. so-called pallet, which in cross--s_.ection is e.g. a quadratic, elongated element, provided on the side e.g. with T-shaped fastening grooves for fixing the pieces to be worked therein. single pallet can be fitted with a plurality of workpieces on one or more sides of a pallet. A pallet is mounted on the machine table for the period of working. In the case of e.g. a vertical spindle machine tool, the machine table can be dis¬ placed in the directions of X- and Y-axes and a spindle, rotatable around a. vertical axis and fitted with a tool, can be displaced in the direction of Z-axis or in vertical direction. If it is desired to work e.g. on the opposite sides of a workpiece, a pallet must be. released and turned over in between.. As an alternat¬ ive, the workpieces must be removed from a pallet and turned over. This removal, fitting and re-fastening requires labour and time, bringing down the capacity of a machine tool and increasing labour costs per piece.

An object of the invention is to provide a novel apparatus for fitting workpiece fastening pallets in a machine tool so as to facilitate a more versatile working of the pieces without removal, positioning and re-fastening.

In order to achieve this object, an apparatus of the invention.is characterized by comprising a rigid, horizontal, bed. which is fitted with a rotary table, adapted for. rotation: around a horizontal axis and pro¬ vided with catch means for engaging one end of a pallet,, said bed being fitted at a distance from the rotary table and on. the line of its axis of. rotation with a rotating centering plug for engaging, the other end of a pallet,, a palle to be replaced being fasten- able between the. rotar table and centering plug.

The use of a rotary table in an apparatus o the in¬ vention facilitates rotation of a pallet around its longitudinal axis rapidly and accurately.

An apparatus of the invention is particularly applic¬ able to a vertical spindle machine tool, comprising a body, horizontal crosswise guideways on the body, a carriage movable on the crosswise guideways, horizontal lengthwise guideways on the carriage, a table movable on the lengthwise guideways for supporting a pallet for fastening the pieces to be worked,, vertical guide- ways mounted on the body for vertical displacement of a rota able vertical spindle, as well as means at the spindle end for fastening a tool. When a bed of the invention, together with its rotary table and center¬ ing plug, is placed on the table of such a machine tool, the relative disposition of a tool and workpiece will be provided with another dimension of movement in addition to the normal dimensions of movement x, y and z of a machine tool.

By virtue of an apparatus of the invention, a workpiece can be approached from all. three, sides with, vertical tool feed in a carefully determined direction. The five sides of a workpiece can. be machined, with just one mounting.

The invention can be applied e.g.. to. the. working of a thread, if- a. shaft- to be. threaded is placed in. the apparatus instead of. a pallet and the. speed of rotat- ion of a continuously operated rotary table, is. synch¬ ronized in. view of the lengthwise movement of the machine table. The pitch of thread can. be chosen by selecting the ratio between, sai speed of. rotation and lengthwise movement. . Threads have been machined in the prior art by- employing a mechanical coupling between the driving mechanism of a :shaft to be thread¬ ed and the lengthwise feed mechanism. When employing an electrically driven rotary table, the movements must be synchronized by means of electric, synchronizat¬ ion elements. Thus, also, the ratio of operating speeds is readily adjustable. . However, the most important application of the invention is fastening of pallets to a machine tool.

The invention will now be described with reference made to the accompanying drawings, in which

fig. 1 shows an apparatus of the invention in sidp view and its bed in elevation.

Fig. 2 shows an apparatus of the invention in connect¬ ion with a .vertical spindle machine tool, the machine tool being shown in a front, view.

Fig. 3 is a side, view of the machine tool of fig. 1, fitted with an. apparatus of the invention.

The apparatus shown in fig. 1 comprises a rigid, hori¬ zontal bed.5, on. top of which is mounted a rotary table 11 ro.tatable around a horizontal axis 18. As well-known, in the art,, the actual, table section of a rotary table is .mechanically, ro.tatable. and lockable at a variety of carefully determined angles. Moreover, a. rotary, table can be* contihubusly driven at. a desired speed of. rotation. In. terms of both; accuracy and support system, a particularly preferred rotary table has bee disclosed in. the Applicants¹ earlier FI Patent application No. 834866.

The rotary table 11 is provided, with a compressed-air distributor 12,. whose, fixed outer rim is fitted with compressed-air hoses and the internal surface of said fixed outer rim is sealed against a rotating rim. Reference numeral 13 designates pneumatic fastening means. In the present case, said fastening- means are designed as a jaw chuck for engaging not only the end of a fastening pallet but also shorter elements that are supported only on rotary table 11, 13. If all that is desired is engagement between the pallet end and rotary table, said fastening means 13 may comprise a pneumatically operated conic seat engaging a match¬ ing conic seat at the end of a pallet, rotation around the shaft being prevented by means of a hole-plug grip between the components.

In view of fastening the other end of a pallet, the apparatus is provided with a rotating centering plug 15, whose axis of rotation coincides with that 18 of rotary table 11. Also said centering plug 15 can be displaceable by means of a pneumatic cylinder in the direction of axis 18. A mounting block 19 of plug 15 can be fixed at various distances from rotary table 11.

Fig. 2 shows the application of this apparatus to a vertical spindle machine tool. Upon the crosswise guideways 2 of the machine tool body 1 is mounted a transversely mobile carriage 3,. whose top surface is in turn provided with lengthwise guideways 3a.. The machine table 4. is longitudinally mobile on guideways 3. Mounted on. top of. said table 4 is a. bed.5 with- its rotary, table^' 11 and centering plug 15. A workpiece fastening pallet 14 is. secured between fastening means 12, 13 on rotary, table .11. and centering plug 15 and said pallet is. rotatable around axis 18.

The machine body 1. is also fitted with, vertical guide- ways 6 for. vertically displacing a body member 7. Journalled to said body member 7 is a vertical, rotat¬ able spindle 8 whose driving means are located inside the body member 7. Inside: said body member 7 are means for controlling the x- and y-directed movements of table 4 and z-directed movements of spindle 8, as- dictated by the control commands received from a control and operating panel 10.

The end of spindle 8 is provided with elements for fastening tools. tool changer 9 can be used for mounting, various tools on spindle 8.

It has been possible to make the operation of a con¬ ventional vertical, spindle machine tool substantially more effective and. versatile when a pallet 14 and workpieces can, by means of rotary table 11, be turned and locked at carefully determined positions.

Instead of pneumatic equipment, the fastening and re¬ lease of pallets can of course be effected by. means of hydraulic piston-cylinder units, if major fasten¬ ing forces are required, when using heavier units.

Claims

1. An apparatus for fitting workpiece fastening pallets (14) in a machine tool, c h. a r a c t e r 1 z e d in that said apparatus comprises a rigid, horizontal bed (5), fitted with a rotary table (.11) which is adapted for rotation around a horizontal axis and provided with catch means (12, 13) for engaging one end of. a pallet (14), said bed (5)^' being at a distance from said rotary table (11) and on its axial line of rota-r tion (18) fitted with a rotating centering plug (15) for engaging the other end of a pallet, a pallet to be re¬ placed being fastenable between the rotary table and centering plug.

2. An apparatus as. set forth in claim 1, c h a r a c t e r i z e d in that said catch means (12, 13) and/or centering plug (15) are fitted with a pneumatically or hydraulically operated piston- cylinder unit, adapted to move catch means (13) and/or centering plug (15) in the direction of said axial line of rotation (18) for squeezing a pallet between catch means. (13) and centering plug (15) .

3. An apparatus as set forth in claim 1 or 2 for fitting workpiece fastening pallets in a. vertical spindle machine tool, comprising a body (1), horizontal crosswise guideways (2). on the body, a carriage (3) movable on.the crosswise guideways, horizontal length¬ wise guideways (3a) on the cradle, a table (4) movable on the lengthwise guideways for. supporting a pallet (14) for fastening the pieces, to be worked,, vertical guideways (6) mounted on the body for. vertical dis¬ placement of. a rotatable vertical, spindle (8),. as well as means at the end of: spindle (8) for fastening, a - tool,: c h a r a c t e r- i z e d in that said bed (5) , together, with its rotary table (11) and centering plug (15) , is adapted to be mounted on a machine tool table (4).

4. A vertical spindle machine tool as. set forth in claim 3 in which bed (5) is mounted on table (4) of a machine tool, c h a r a c t e r i z e d in that the speed of rotation of said continuously rotated rotary table can be set by means of electric synchronizing elements at a certain ratio with respect to the traveling speed of table (4) .

5. A machine tool as set forth in claim 4, c h a r a c t e r i z e d in that the speed of rotat¬ ion of said continuously driven rotary table can be synchronized relative to the lengthwise movement of table (4).